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1

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

E-print Network

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

Harris, Thomas C. (Thomas Cameron)

2006-01-01

2

High-resolution 2-deoxyglucose autoradiography in quick-frozen slabs of neonatal rat olfactory bulb.  

PubMed

We have used rapid freezing and freeze-substitution fixation to permit electron microscopic study of [3H]2-deoxyglucose autoradiographs. The techniques minimize diffusion of label into processing fluids and, by inference, migration of label within tissue. Slabs of olfactory bulbs from 12-day-old rats were quick-frozen after one hour of exposure to physiological olfactory stimuli. In light microscopic autoradiographs at low magnification, the neuropil of individual olfactory glomeruli appeared uniformly labeled with different levels of labeling in different glomeruli. At higher magnification, glomerular neuropil labeling consisted of small unlabeled regions surrounded by label clusters, suggesting greater deoxyglucose uptake by olfactory nerve terminals as compared with their postsynaptic dendrites. Periglomerular neurons were labeled differentially. Some microglia and glia precursor cells were heavily labeled in all bulbar laminae. The ultrastructure of cells and neuropil in all bulbar laminae was well-preserved. Cell processes and organelles could be identified in both stained sections and unstained electron microscopic autoradiographs. These experiments demonstrate the feasibility of combining quick-freezing with freeze substitution, in order to extend the resolution of studies using diffusable tracers such as 2-deoxyglucose. The results suggest that this is a promising method for assessing several controversies concerning deoxyglucose incorporation and neuronal and glial metabolism. PMID:4027617

Benson, T E; Burd, G D; Greer, C A; Landis, D M; Shepherd, G M

1985-07-22

3

High resolution track etch autoradiography  

DOEpatents

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.

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

1994-01-01

4

Resolution, sensitivity and precision with autoradiography and small animal positron emission tomography: implications for functional brain  

E-print Network

in the environment. A disadvantage of these autoradiographic methods is that experimental animals can be studied only in experimental animals with PET. These developments allow repeated studies of the same animal, including studiesResolution, sensitivity and precision with autoradiography and small animal positron emission

Smith, Carolyn Beebe

5

Lack of effect of high-dose cocaine on monoamine uptake sites in rat brain measured by quantitative autoradiography  

Microsoft Academic Search

There have been a number of claims that high-dose administration of cocaine to rats leads to neurotoxic effects on dopamine neurons. In this study possible neurotoxic effects on monoamine neurons were examined by measuring the effects of cocaine (35 mg\\/kg daily for 10 days) on the binding of radioligands to uptake sites for dopamine, serotonin and norepinephrine using quatitative autoradiography.

S. Benmansour; S. M. Tejani-Butt; M. Hauptmann; D. J. Brunswick

1992-01-01

6

High resolution computed tomography  

NASA Astrophysics Data System (ADS)

High resolution (greater than 4 line pairs per millimeter) computed tomography (CT) was studied for its potential use for engineering evaluation of aerospace components. The CT images provide two dimensional maps of material linear x ray attenuation coefficients for small volume elements, smaller than 0.001 cubic millimeters. These images are similar to micrographic images of polished surfaces from sectioned components, but are achieved nondestructively. For investigating materials where destructive sectioning relieves stresses, changing the internal configuration of features, such as gaps, high resolution CT provides superior diagnostic information for engineering evaluation. The primary benefits of CT are realized in accelerating schedules through faster data acquisition and reducing engineering risk by providing increased information nondestructively. High resolution CT is particularly well suited to assist in failure analysis investigations. Multiple slice or volume reconstruction high resolution CT can provide full three dimensional models. The cost and performance of high resolution CT systems are functions of the component size and ultimate resolution capability. For many common evaluation needs, the capital cost can be as low as a 50 percent cost add-on to a real-time radiographic imaging system. Relative to micrography, CT can be performed in about on-fifth the time, depending on the number of samples.

Bossi, Richard H.; Cline, John L.; Georgeson, Gary E.

1992-07-01

7

High resolution drift chambers  

SciTech Connect

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.

Va'vra, J.

1985-07-01

8

High resolution data acquisition  

SciTech Connect

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. 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.

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

1992-12-31

9

A METHOD FOR INTRACELLULAR AUTORADIOGRAPHY IN THE ELECTRON MICROSCOPE  

Microsoft Academic Search

A technic is described for high resolution intracellular autoradiography in the electron microscope. Cultures of LLC-MK2 monkey kidney cells were incubated for 72 hours in a medium containing 0.4 #curie per ml of thymidine-H 3. After labeling, the cells were fixed with osmium tetroxide and embedded in methacrylate. Ultrathin sections of the labeled tissue were taken up on Formvar-coated and

M. H. Silk; A. O. Hawtrey; I. M. Spence; J. H. S. Gear

1961-01-01

10

High resolution infrared measurements  

NASA Technical Reports Server (NTRS)

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

Kessler, B.; Cawley, Robert

1990-01-01

11

Saturn's rings - high resolution  

NASA Technical Reports Server (NTRS)

Voyager 2 obtained this high-resolution picture of Saturn's rings Aug. 22, when the spacecraft was 4 million kilometers (2.5 million miles) away. Evident here are the numerous 'spoke' features, in the B-ring; their very sharp, narrow appearance suggests short formation times. Scientists think electromagnetic forces are responsible in some way for these features, but no detailed theory has been worked out. Pictures such as this and analyses of Voyager 2's spoke movies may reveal more clues about the origins of these complex structures. The Voyager project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

1981-01-01

12

High resolution digital thermometer  

NASA Astrophysics Data System (ADS)

A high resolution digital thermometer is disclosed. The thermometer is capable of measuring temperature differences on the order of several micro-degrees centigrade. The device includes a bridge circuit having two thermistors in series. An output of the bridge circuit feeds a signal to an analog-to-digital converter via a high gain amplifier. A computer maintains the balance of the bridge circuit to avoid a situation wherein the range of the analog-to-digital convertor would be exceeded. Because the present invention utilizes two thermistors between which temperature differences are measured, the present invention is particularly advantageous when the two thermistors are in reference and test positions in apparatus for chemical and/or biochemical analysis. For example, in the case of chemical analyzers, one of the thermistors may be positioned in thermal contact with a reaction mixture of interest while the other thermistor may be maintained in thermal contact with a standard or reference solution.

Friauf, Walter S.; Clem, Thomas R.; Berger, Robert L.

1992-02-01

13

High resolution ultrasonic densitometer  

SciTech Connect

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.

Dress, W.B.

1983-01-01

14

High resolution ultrasonic densitometer  

SciTech Connect

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.

Dress, W.B.

1983-01-01

15

High resolution ultrasonic densitometer  

NASA Astrophysics Data System (ADS)

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 indiction, and precise inventory control for such diverse fluids as uranium salt solutions in accountability storage and gasoline in service station storage tanks.

Dress, W. B.

1983-11-01

16

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

SciTech Connect

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.

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

1985-07-01

17

High resolution digital delay timer  

Microsoft Academic Search

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.

Albert D

1988-01-01

18

A High Resolution Performance Monitoring  

E-print Network

. It utilises features of the Intel Pentium chip set to produce a high resolution and accurate measurement Resolution, Accurate, Pentium, Performance Monitoring I. INTRODUCTION The history of electrical time keeping

19

A Very High Spatial Resolution Detector for Small Animal PET  

SciTech Connect

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

Kanai Shah, M.S.

2007-03-06

20

Gravitational instability with high resolution  

NASA Technical Reports Server (NTRS)

A series of very high resolution simulations have been performed for gravitational clustering in two dimensions. It is shown that mass resolution, achieved by having large numbers of particles, is as important as spatial resolution. New objects arising inside pancakes are found, which are coherent with structure on much larger scales. The evolution of structure in hierarchical clustering models with a sufficiently flat power spectrum includes pancake-like structures, confirming the presence of filaments in cold dark matter universes.

Melott, Adrian L.; Shandarin, Sergei F.

1989-01-01

21

High-resolution radar imaging  

Microsoft Academic Search

The goal of this project is to formulate and investigate new approaches for forming images of radar targets from spotlight-mode, delay-Doppler measurements. These measurements can be acquired with a high-resolution radar-imaging operating with an optical- or radio-frequency carrier. Work in this reporting period has concentrated on our estimation-theory approach to forming high resolution images. This approach accounts for measurement noise

Donald L. Snyder

1990-01-01

22

High resolution digital delay timer  

DOEpatents

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).

Martin, Albert D. (Los Alamos, NM)

1988-01-01

23

Berkeley High-Resolution Ball  

SciTech Connect

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

Diamond, R.M.

1984-10-01

24

Autoradiography of phosphatidyl choline  

SciTech Connect

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.

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

1981-03-01

25

Advanced very high resolution radiometer  

NASA Technical Reports Server (NTRS)

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.

1976-01-01

26

High Resolution Orientation Imaging Microscopy.  

National Technical Information Service (NTIS)

This report summarizes the progress and achievements resulting from the Army Research Office grant number WF911NF-08-1-0350 on the subject of High Resolution Orientation Imaging Microscopy. The central technical outcome of the project is a new methodology...

B. Adams, D. Fullwood

2012-01-01

27

High resolution optical DNA mapping  

NASA Astrophysics Data System (ADS)

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.

Baday, Murat

28

High resolution tomographic instrument development  

SciTech Connect

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.

Not Available

1992-08-01

29

High resolution tomographic instrument development  

SciTech Connect

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.

Not Available

1992-01-01

30

High Resolution CMOS Current Comparators  

Microsoft Academic Search

A 2m CMOS current comparator prototype is presented with an input current comparison range of 140dB and virtual zero offset(?10pA). The circuit uses capacitive sensing for high resolution and nonlinear feedback to achieve small input voltage variations in the complete input current range. Operation speed for low current is abot two orders of magnitude larger than for conventional circuits. Simplified

R. Dominguez-Castro; A. Rodriguez-Vazquez; F. Medeiro; J. L. Huertas

1992-01-01

31

High Resolution Thermometry for EXACT  

NASA Technical Reports Server (NTRS)

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.

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

2000-01-01

32

High-Resolution Imaging Spectrometer  

NASA Technical Reports Server (NTRS)

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.

Dozier, Jeff; Goetz, Alexander F. H.

1990-01-01

33

High resolution time interval counter  

NASA Technical Reports Server (NTRS)

In recent years, we have developed two types of high resolution, multi-channel time interval counters. In the NIST two-way time transfer MODEM application, the counter is designed for operating primarily in the interrupt-driven mode, with 3 start channels and 3 stop channels. The intended start and stop signals are 1 PPS, although other frequencies can also be applied to start and stop the count. The time interval counters used in the NIST Frequency Measurement and Analysis System are implemented with 7 start channels and 7 stop channels. Four of the 7 start channels are devoted to the frequencies of 1 MHz, 5 MHz or 10 MHz, while triggering signals to all other start and stop channels can range from 1 PPS to 100 kHz. Time interval interpolation plays a key role in achieving the high resolution time interval measurements for both counters. With a 10 MHz time base, both counters demonstrate a single-shot resolution of better than 40 ps, and a stability of better than 5 x 10(exp -12) (sigma(sub chi)(tau)) after self test of 1000 seconds). The maximum rate of time interval measurements (with no dead time) is 1.0 kHz for the counter used in the MODEM application and is 2.0 kHz for the counter used in the Frequency Measurement and Analysis System. The counters are implemented as plug-in units for an AT-compatible personal computer. This configuration provides an efficient way of using a computer not only to control and operate the counters, but also to store and process measured data.

Zhang, Victor S.; Davis, Dick D.; Lombardi, Michael A.

1995-01-01

34

High-Resolution Intravital Microscopy  

PubMed Central

Cellular communication constitutes a fundamental mechanism of life, for instance by permitting transfer of information through synapses in the nervous system and by leading to activation of cells during the course of immune responses. Monitoring cell-cell interactions within living adult organisms is crucial in order to draw conclusions on their behavior with respect to the fate of cells, tissues and organs. Until now, there is no technology available that enables dynamic imaging deep within the tissue of living adult organisms at sub-cellular resolution, i.e. detection at the level of few protein molecules. Here we present a novel approach called multi-beam striped-illumination which applies for the first time the principle and advantages of structured-illumination, spatial modulation of the excitation pattern, to laser-scanning-microscopy. We use this approach in two-photon-microscopy - the most adequate optical deep-tissue imaging-technique. As compared to standard two-photon-microscopy, it achieves significant contrast enhancement and up to 3-fold improved axial resolution (optical sectioning) while photobleaching, photodamage and acquisition speed are similar. Its imaging depth is comparable to multifocal two-photon-microscopy and only slightly less than in standard single-beam two-photon-microscopy. Precisely, our studies within mouse lymph nodes demonstrated 216% improved axial and 23% improved lateral resolutions at a depth of 80 m below the surface. Thus, we are for the first time able to visualize the dynamic interactions between B cells and immune complex deposits on follicular dendritic cells within germinal centers (GCs) of live mice. These interactions play a decisive role in the process of clonal selection, leading to affinity maturation of the humoral immune response. This novel high-resolution intravital microscopy method has a huge potential for numerous applications in neurosciences, immunology, cancer research and developmental biology. Moreover, our striped-illumination approach is able to improve the resolution of any laser-scanning-microscope, including confocal microscopes, by simply choosing an appropriate detector. PMID:23251402

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

2012-01-01

35

The High Spectral Resolution Lidar  

NASA Technical Reports Server (NTRS)

The High Spectral Resolution Lidar (HSRL) system was developed for the remote measurement of atmospheric optical properties. Measurements are obtained by the separation of the backscattered signal into aerosol and molecular channels using a high spectral resolution Fabry-Perot optical interferometer to separate the aerosol contributions to backscatter near the laser wavelength from the Doppler-shifted molecular component of the backscatter. The transmitter consists of an optically pumped pulsed dye laser of the oscillator-amplifier design which emits at 467.88 nm, with a bandwidth of less than 0.3 pm. The transmitter and receiver share a common Schmidt-Cassegrain telescope, although they do not share the same field stop, but rather two conjugate stops. The HSRL system uses a computer-controlled dual-channel photon-counting data acquisition system providing for stable measurements at very low power levels and an excellent dynamic range. The system has been used to obtain airborne measurements of height profiles of aerosol and molecular backscatter cross sections.

Eloranta, E. W.; Roesler, F. L.; Sroga, J. T.

1983-01-01

36

High-Resolution Mass Spectrometers  

NASA Astrophysics Data System (ADS)

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

Marshall, Alan G.; Hendrickson, Christopher L.

2008-07-01

37

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

E-print Network

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

Melvin, Stephen

38

Ultra-high resolution AMOLED  

NASA Astrophysics Data System (ADS)

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 19201200 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.

Wacyk, Ihor; Prache, Olivier; Ghosh, Amal

2011-06-01

39

High-resolution slug testing.  

PubMed

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

Zemansky, G M; McElwee, C D

2005-01-01

40

High resolution imaging at Palomar  

NASA Technical Reports Server (NTRS)

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.

Kulkarni, Shrinivas R.

1992-01-01

41

High Resolution, High Frame Rate Video Technology  

NASA Technical Reports Server (NTRS)

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.

1990-01-01

42

High Resolution Satellite Image Orientation Models  

Microsoft Academic Search

\\u000a A few years ago high resolution satellite imagery became available to a limited number of government and defense agencies\\u000a that managed such imagery with highly sophisticated software and hardware tools. Such images became available to civil users\\u000a in 1999 with the launch of Ikonos, the first civil satellite offering a spatial resolution of 1 m. Since then other high resolution

Mattia Crespi; Francesca Fratarcangeli; Francesca Giannone; Francesca Pieralice

43

High resolution amorphous silicon radiation detectors  

DOEpatents

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.

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

1992-05-26

44

High resolution amorphous silicon radiation detectors  

DOEpatents

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.

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

1992-01-01

45

High resolution laser imaging system.  

PubMed

Computations indicate that a synthetic aperture laser imaging system can provide images with 10-cm resolution at satellite ranges using a 10-W cw laser. When imaging satellites from the ground, the synthetic aperture system reduces atmospheric degradations. The system uses 20-cm diam receiver optics. The low laser power is made possible by using separate transmitter and receiver optics and coded pulses with a 50% transmitter duty cycle. The coded pulses are derived from Hadamard matrices for which there is an efficient algorithm to transform the received data into images. The synthetic aperture yields spatial resolutions independent of range, and the coded pulses result in an effective range dependence of r(-2)2 instead of r(-4). PMID:20555574

Kyle, T G

1989-07-01

46

High resolution scintillation detector with semiconductor readout  

DOEpatents

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.

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

2000-01-01

47

Identifying chromatin interactions at high spatial resolution  

E-print Network

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

Reeder, Christopher Campbell

2014-01-01

48

MWPC-Based Automatic Systems for Electronic Autoradiography  

Microsoft Academic Search

Several systems based on multiwire proportional chambers (MWPC) used to study protein mixtures labelled with H, C, P, S and I are described. The detector operates on-line with a computer. Autoradiography imaging is presented on a colour TV-monitor. The spatial resolution of the systems is 1 2 mm, and the sensitivity is about 10 pCi\\/cm. The systems make it

Yu. V. Zanevsky; D. A. Abdushukurov; Yu. S. Anisimov; G. A. Cheremukhina; S. P. Chernenko; V. D. Peshekhonov; Tehan Due Thanh

1987-01-01

49

High resolution reconstruction of ISAR images  

Microsoft Academic Search

A 2-D high-resolution spectral analysis algorithm with application to an inverse synthetic aperture radar (ISAR) imaging, is presented. This algorithm is based on two-dimensional linear prediction using autoregressive (AR) coefficients. Stability is guaranteed by AR process pole adjustment. An ISAR target is modeled for a complex scatterer geometry. Computer simulation results are provided for the high-resolution reconstruction of ISAR images

R. M. Nuthalapati

1992-01-01

50

High resolution SAR applications and instrument design  

NASA Technical Reports Server (NTRS)

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

Dionisio, C.; Torre, A.

1993-01-01

51

High Resolution Cinematography at High Temperature in the Electron Microscope  

Microsoft Academic Search

Required microscope conditions and the technique of photography and development procedures are described, and means of improvement suggested for high resolution, high magnification 16 mm cinematography of chemical reactions at high temperature in the electron microscope. It is shown experimentally that, even with an externally mounted camera, resolutions of 1215 can be achieved in practice at reaction temperatures of

Frank D. Lugton; Charles E. Warble

1970-01-01

52

High resolution ceramic gun for projection CRT  

NASA Astrophysics Data System (ADS)

A ceramic resistor with high-resistivity and a low thermal coefficient has been developed. The use of this ceramic material as a cylindrical electrode realizes an electrostatic lens with low spherical aberration. A ceramic electron gun based on a new concept has been developed for high resolution projection CRTs.

Muchi, T.; Tagami, S.; Saito, T.

1995-08-01

53

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

NASA Astrophysics Data System (ADS)

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.

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

2013-01-01

54

Solar system events at high spatial resolution  

SciTech Connect

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.

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

55

RAPID DAMAGE ASSESSMENT FROM HIGH RESOLUTION IMAGERY  

SciTech Connect

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.

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

2008-01-01

56

High Resolution and High Collection Efficiency of Single Quantum Dots.  

E-print Network

High Resolution and High Collection Efficiency of Single Quantum Dots. A. N. Vamivakas1 ,Z. Liu2GaAs quantum dots (QDs) grown by Stranski-Krastanow self-assembly on GaAs substrates [1]. In self-assembled QD the resolution and collection efficiency of our optical microscopy system. In contrast to conventional Solid

57

High Resolution Supply Chain Management Resolution of the polylemma of production by  

E-print Network

High Resolution Supply Chain Management � Resolution of the polylemma of production by information.Stich@fir.rwth-aachen.de Abstract. High Resolution Supply Chain Management (HRSCM) aims to stop the trend of continuously increasing). "High Resolution Supply Chain Management" focuses to solve the dilemma be- tween a high grade

Paris-Sud XI, Université de

58

High-resolution two dimensional advective transport  

USGS Publications Warehouse

The paper describes a two-dimensional high-resolution scheme for advective transport that is based on a Eulerian-Lagrangian method with a flux limiter. The scheme is applied to the problem of pure-advection of a rotated Gaussian hill and shown to preserve the monotonicity property of the governing conservation law.

Smith, P.E.; Larock, B.E.

1989-01-01

59

University of Wisconsin High Spectral Resolution Lidar  

Microsoft Academic Search

The University of Wisconsin High Spectral Resolution Lidar (UW HSRL) is analyzed. The UW HSRL produces direct measurements of cloud and aerosol optical depth, extinction cross section, backscatter cross section, and backscatter phase function. A multietalon interferometer is used to separate the backscatter return into a component due to particle scattering and a component due to scattering from air molecules.

Christian J. Grund; Edwin W. Eloranta

1991-01-01

60

Development of high spectral resolution lidar technology  

Microsoft Academic Search

The first year of this grant has been devoted to the design and construction of an upgraded version of the University of Wisconsin High Spectral Resolution Lidar (HSRL). The new system incorporates additional data channels to measure depolarization and multiple scattering in the lidar return. Schematic diagrams describing the new configurations are attached to this report. Increases in optical efficiency

E. W. Eloranta

1991-01-01

61

High resolution tomography with chemical specificity  

Microsoft Academic Search

A very fast method of computerized critical absorption tomography featuring ~ 10 mum spatial resolution and high chemical sensitivity is described. Synchrotron radiation is used and the method is especially suited to investigating small samples. From a preliminary experiment it is found that layers of neighboring elements only 0.2 mum thick can be distinguished at medium atomic numbers.

U. Bonse; Q. Johnson; M. Nichols; R. Nusshardt; S. Krasnicki; J. Kinney

1986-01-01

62

High Resolution Sea Surface Temperature Field Derived.  

National Technical Information Service (NTIS)

A procedure for deriving high resolution sea surface temperature field from digital AVHRR/HRPT data is described. For the purpose of reducing the processing time, only the reflective threshold or near infrared channel is used for selecting data over clear...

S. Zhou, W. Chen, L. Zhang

1986-01-01

63

High Resolution Computed Tomography of Positron Emitters  

Microsoft Academic Search

High resolution computed transaxial tomography has been performed on phantoms containing positron-emitting isotopes. The imaging system consisted of two opposing groups of eight NaI(T1) crystals 8 mm ?? 30 mm ?? 50 mm deep and the phantoms were rotated to measure coincident events along 8960 projection integrals as they would be measured by a 280 crystal ring system now under

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

1977-01-01

64

A High-Resolution Stopwatch for Cents  

ERIC Educational Resources Information Center

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

Gingl, Z.; Kopasz, K.

2011-01-01

65

CONFOCAL FABRY-PEROT INTERFEROMETER BASED HIGH SPECTRAL RESOLUTION LIDAR  

E-print Network

CONFOCAL FABRY-PEROT INTERFEROMETER BASED HIGH SPECTRAL RESOLUTION LIDAR by David Swick Hoffman....................................................................................3 Lidar............................................................................................................4 High Spectral Resolution Lidar

Lawrence, Rick L.

66

Detectors for high resolution dynamic pet  

SciTech Connect

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

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

1983-05-01

67

Scanning Transmission Electron Microscopy at High Resolution  

PubMed Central

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

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

1974-01-01

68

High resolution electron crystallography of protein molecules  

SciTech Connect

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.

Glaeser, R.M. [California Univ., Berkeley, CA (United States). Dept. of Molecular and Cell Biology]|[Lawrence Berkeley Lab., CA (United States); Downing, K.H. [Lawrence Berkeley Lab., CA (United States)

1993-06-01

69

High-temporal resolution multimode photospectropolarimeter  

NASA Astrophysics Data System (ADS)

A hardware and software complex of the MANIA experiment designed to search for and study the photometric variability of astrophysical objects with a temporal resolution of 10-6 s is described. The panoramic photospectropolarimeter uses interchangeable optical units, which allow the observations to be performed in four modesspectroscopic, spectropolarimetric, photometric, and polarimetric. A coordinatesensitive detector equipped with a set of microchannel plates is capable of recording flux fluctuations from objects and comparison stars simultaneously in different photometric bands and in different polarization planes. The Quantochron 4-48 data acquisition facility operating on line with a computer acquires observational data with a temporal resolution of 1microsecond. The methods of analysis of panoramic data with high temporal resolution are discussed.

Plokhotnichenko, V. L.; Beskin, G. M.; de Bur, V. G.; Karpov, S. V.; Bad'in, D. A.; Lyubetskaya, Z. V.; Lyubetskij, A. P.; Pavlova, V. V.

2009-07-01

70

Constructing a WISE High Resolution Galaxy Atlas  

NASA Technical Reports Server (NTRS)

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.

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

71

Constructing a WISE High Resolution Galaxy Atlas  

E-print Network

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

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

2012-01-01

72

High-resolution flurescence spectroscopy in immunoanalysis  

SciTech Connect

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.

Grubor, Nenad M.

2005-05-01

73

Conversational high resolution mass spectrographic data reduction  

NASA Technical Reports Server (NTRS)

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.

Romiez, M. P.

1973-01-01

74

High-resolution, multicolor organic LED displays  

Microsoft Academic Search

We are developing high-resolution, multicolor displays based on the integration of fluorescent color filter arrays and monocolor organic light emitting diode arrays. A single organic light emitting diode pixel produces blue light which is absorbed by a fluorescent sub-pixel. The sub-pixel re-emits the absorbed light in a lower energy spectral range and thus converts the blue light to green or

R. H. Jordan; N. Armstrong; D. Savage; Ching Tang

1998-01-01

75

High spatial resolution passive microwave sounding systems  

NASA Technical Reports Server (NTRS)

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.

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

1986-01-01

76

High-Resolution Sonography of Acute Appendicitis  

Microsoft Academic Search

During a 7-month period high-resolution sonography was used in the evaluation of 68 patients with an equivocal clinical diagnosis of acute appendicitis. The sonographic findings were correlated with surgical-pathologic outcome in 32 cases and with clinical follow-up in the remainder. This technique was found to be accurate in the diagnosis of acute appendicitis with a specificity of 95%, a sensitivity

Monzer M. Abu-Yousef; Jon J. Bleicher; James W. Maher; Luis F. Urdaneta; Edmund A. Franken; Amanda M. Metcalf

77

Obtaining high resolution XUV coronal images  

NASA Technical Reports Server (NTRS)

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.

Golub, L.; Spiller, E.

1992-01-01

78

High Resolution Measurement of the Glycolytic Rate  

PubMed Central

The glycolytic rate is sensitive to physiological activity, hormones, stress, aging, and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K+, supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts, and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis. PMID:20890447

Bittner, Carla X.; Loaiza, Anitsi; Ruminot, Ivan; Larenas, Valeria; Sotelo-Hitschfeld, Tamara; Gutierrez, Robin; Cordova, Alex; Valdebenito, Rocio; Frommer, Wolf B.; Barros, L. Felipe

2010-01-01

79

High resolution measurement of the glycolytic rate.  

PubMed

The glycolytic rate is sensitive to physiological activity, hormones, stress, aging, and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K(+), supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts, and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis. PMID:20890447

Bittner, Carla X; Loaiza, Anitsi; Ruminot, Ivn; Larenas, Valeria; Sotelo-Hitschfeld, Tamara; Gutirrez, Robin; Crdova, Alex; Valdebenito, Roco; Frommer, Wolf B; Barros, L Felipe

2010-01-01

80

Parathyroid imaging: comparison of high-resolution CT and high-resolution sonography  

SciTech Connect

Parathyroid computed tomographic (CT) scanning using a specially designed patient positioning harness, bolus contrast administration, and dynamic scanning significantly improved localization of parathyroid tumors from 45% (19/42) to 76% (35/46) (p < 0.01) over conventional CT scanning. High-resolution sonography with a 10 MHz transducer localized 65% (57/88) of these tumors. Average tumor size was 15 x 10 x 9 mm. Patients undergoing reoperation for hyperparathyridism had similarly small tumors localized by CT in 63% (12/19) and high-resolution sonography in 47% (9/19) of cases. High-resolution sonographic equipment suitable for parathyroid imaging is not widely available. Since high-resolution CT is more generally available and more effective, it is recommended as the procedure of choice for localizing cervical parathyroid tumors.

Stark, D.D. (Univ. of California, San Francisco); Gooding, G.A.W.; Moss, A.A.; Clark, O.H.; Ovenfors, C.O.

1983-10-01

81

A high resolution ultraviolet Shuttle glow spectrograph  

NASA Technical Reports Server (NTRS)

The High Resolution Shuttle Glow Spectrograph-B (HRSGS-B) is a small payload being developed by the Naval Research Laboratory. It is intended for study of shuttle surface glow in the 180-400 nm near- and middle-ultraviolet wavelength range, with a spectral resolution of 0.2 nm. It will search for, among other possible features, the band systems of excited NO which result from surface-catalyzed combination of N and O. It may also detect O2 Hertzberg bands and N2 Vegard-Kaplan bands resulting from surface recombination. This wavelength range also includes possible N2+ and OH emissions. The HRSGS-B will be housed in a Get Away Special canister, mounted in the shuttle orbiter payload bay, and will observe the glow on the tail of the orbiter.

Carruthers, George R.

1993-01-01

82

Computer synthesis of high resolution electron micrographs  

NASA Technical Reports Server (NTRS)

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.

Nathan, R.

1976-01-01

83

Effective Use of High-Resolution Models  

NSDL National Science Digital Library

High-resolution models have transitioned from research into forecast operations, helping forecasters utilize additional mesoscale information after accounting for the inherent unpredictability of many small-scale phenomena. This module covers the major capabilities and limitations of models run without a convective parameterization using grid spacings of around 4 km or less. Model forecast interpretation issues are discussed, including introducing convective mode diagnostics such as updraft helicity and interpreting the forecast as an event prediction rather than as a precise point forecast. Many examples are shown and twenty interactions engage the reader throughout the module.

Comet

2010-06-15

84

High resolution switching magnetization magnetic force microscopy  

NASA Astrophysics Data System (ADS)

We introduce switching magnetization magnetic force microscopy based on two-pass scanning atomic force microscopy with reversed tip magnetization between the scans. Within this approach the sum of the scanned data with reversed tip magnetization depicts local van der Waals forces, while their differences map the local magnetic forces. Here we implement this method by fabricating low-momentum magnetic probes that exhibit magnetic single domain state, which can be easily reversed in low external field during the scanning. Measurements on high-density parallel and perpendicular magnetic recording media show enhanced spatial resolution of magnetization.

Cambel, V.; Precner, M.; Fedor, J.; olts, J.; Tbik, J.; ?epka, T.; Karapetrov, G.

2013-02-01

85

Applied high resolution digital control for universal precision systems  

E-print Network

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

Gawlik, Aaron John

2008-01-01

86

High resolution rainfall measurements around a high rise building  

Microsoft Academic Search

A number of disdrometers (acoustic rain gauge) has been placed around a high rise building on a place where variation in spatial distribution of precipitation is expected, to show the advantage of high resolution rainfall measurements in a urban area. The standard recommendation for the placement of a rain gauge is that the gauge is positioned at a distance corresponding

Stijn de Jong; Nick van de Giesen; Rolf Hut

2010-01-01

87

Daily High-Resolution-Blended Analyses for Sea Surface Temperature  

Microsoft Academic Search

Two new high-resolution sea surface temperature (SST) analysis products have been developed using optimum interpolation (OI). The analyses have a spatial grid resolution of 0.25 and a temporal resolution of 1 day. One product uses the Advanced Very High Resolution Radiometer (AVHRR) infrared satellite SST data. The other uses AVHRR and Advanced Microwave Scanning Radiometer (AMSR) on the NASA Earth

Richard W. Reynolds; Thomas M. Smith; Chunying Liu; Dudley B. Chelton; Kenneth S. Casey; Michael G. Schlax

2007-01-01

88

GaAs pixel radiation detector as an autoradiography tool for genetic studies  

NASA Astrophysics Data System (ADS)

We present an autoradiography tool to be used mainly for genetic studies. It performs a quantitative analysis of radioactivity and can follow a dynamic process. We designed several applications, in particular one aimed at detecting hybridization of radio-labeled DNA fragments with known DNA-probes deposited on a micro-array. The technique is based on GaAs pixel array detector and low threshold, large dynamic range and good sensitivity integrated electronics developed for medical applications, suitable to detect markers (gamma or beta) such as 14C, 35S, 33P, 32P, 125I, even at very low activities. A Monte Carlo simulation of ?- detection in GaAs is presented here in order to study the spatial resolution characteristics of such a system. For several biological applications, the electronics is required to perform at high temperatures (from 37 to 68): we present here studies of noise and minimum threshold as a function of the temperature.

Bertolucci, E.; Conti, M.; Mettivier, G.; Russo, P.; Amendolia, S. R.; Bisogni, M. G.; Bottigli, U.; Ceccopieri, A.; Ciocci, M. A.; Delogu, P.; Fantacci, M. E.; Maestro, P.; Marzulli, V. M.; Pernigotti, E.; Romeo, N.; Rosso, V.; Stefanini, A.; Stumbo, S.

1999-02-01

89

High Resolution Powder Diffraction and Structure Determination  

SciTech Connect

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.

Cox, D. E.

1999-04-23

90

High resolution multimodal clinical ophthalmic imaging system  

PubMed Central

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 m 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 ~0.5 deg (~100-150 m) 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

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

2010-01-01

91

High resolution multimodal clinical ophthalmic imaging system.  

PubMed

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

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

2010-05-24

92

High Resolution BPM for Linear Colliders  

NASA Astrophysics Data System (ADS)

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 ?m and the damping time down to 10 ns.

Simon, C.; Chel, S.; Luong, M.; Napoly, O.; Novo, J.; Roudier, D.; Baboi, N.; Noelle, D.; Mildner, N.; Zapfe, K.; Rouvire, N.

2006-11-01

93

High Resolution Spectroscopy to Support Atmospheric Measurements  

NASA Technical Reports Server (NTRS)

Spectroscopic parameters (such as line position, intensity, broadening and shifting coefficients and their temperature dependences, line mixing coefficients etc.) for various molecular species of atmospheric interest are determined. In order to achieve these results, infrared spectra of several molecular bands are obtained using high-resolution recording instruments such as tunable diode laser spectrometer and Fourier transform spectrometers. Using sophisticated analysis routines (Multispectrum nonlinear least squares technique) these high-resolution infrared spectra are processed to determine the various spectral line parameters that are cited above. Spectra were taken using the McMath-Pierce Fourier transform spectrometer (FTS) at the National Solar Observatory on Kitt Peak, Arizona as well as the Bruker FTS at the Pacific Northwest National Laboratory (PNNL) at Richland, Washington. Most of the spectra are acquired not only at room temperature, but also at several different cold temperatures. This procedure is necessary to study the variation of the spectral line parameters as a function of temperature in order to simulate the Earth's and other planetary atmospheric environments. Depending upon the strength or weakness of the various bands recorded and analyzed, the length(s) of the absorption cells in which the gas samples under study are kept varied from a few centimeters up to several meters and the sample temperatures varied from approximately +30 C to -63 C. Research on several infrared bands of various molecular species and their isotopomers are undertaken. Those studies are briefly described.

Venkataraman, Malathy Devi

2003-01-01

94

Common high-resolution MMW scene generator  

NASA Astrophysics Data System (ADS)

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

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

2001-08-01

95

High-Resolution Scintimammography: A Pilot Study  

SciTech Connect

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.

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

2002-07-01

96

High resolution guided wave pipe inspection  

NASA Astrophysics Data System (ADS)

Commercial guided wave inspection systems provide rapid screening of pipes, but limited sizing capability for small defects. However, accurate detection and sizing of small defects is essential for assessing the integrity of inaccessible pipe regions where guided waves provide the only possible inspection mechanism. In this paper an array-based approach is presented that allows guided waves to be focused on both transmission and reception to produce a high resolution image of a length of pipe. In the image, it is shown that a signal to coherent noise ratio of over 40 dB with respect to the reflected signal from a free end of pipe can be obtained, even taking into account typical levels of experimental uncertainty in terms of transducer positioning, wave velocity etc. The combination of an image with high resolution and a 40 dB dynamic range enables the detection of very small defects. It also allows the in-plane shape of defects over a certain size to be observed directly. Simulations are used to estimate the detection and sizing capability of the system for crack-like defects. Results are presented from a prototype system that uses EMATs to fully focus pipe guided wave modes on both transmission and reception in a 12 inch diameter stainless steel pipe. The 40 dB signal to coherent noise ratio is obtained experimentally and a 2 mm diameter (0.08 wavelengths) half-thickness hole is shown to be detectable.

Velichko, Alexander; Wilcox, Paul D.

2009-03-01

97

High Resolution Spectroscopy to Support Atmospheric Measurements  

NASA Technical Reports Server (NTRS)

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.

Benner, D. Chris; Venkataraman, Malathy Devi

2000-01-01

98

High Resolution Spectroscopy to Support Atmospheric Measurements  

NASA Technical Reports Server (NTRS)

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.

Benner, D. Chris; Venkataraman, Malathy Devi

2000-01-01

99

Ultra-high resolution computed tomography imaging  

DOEpatents

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.

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

100

High resolution Fourier interferometer-spectrophotopolarimeter  

NASA Technical Reports Server (NTRS)

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.

Fymat, A. L. (inventor)

1976-01-01

101

Clementine High Resolution Camera Mosaicking Project  

NASA Astrophysics Data System (ADS)

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.

1998-10-01

102

Potential High Resolution Dosimeters For MRT  

SciTech Connect

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.

Braeuer-Krisch, E.; Brochard, T.; Prezado, Y.; Bravin, A.; Berkvens, P. [European Synchrotron Radiation Facility (ESRF), 6 rue Horowitz, BP220, F-38043 Grenoble (France); Rosenfeld, A.; Lerch, M.; Petasecca, M. [Centre for Medical Radiation Physics, University of Wollongong, Wollongong, NSW 2522 (Australia); Akselrod, M.; Sykora, J.; Bartz, J. [Landauer, Inc., Stillwater Crystal Growth Division, Stillwater OK, 74074 (United States); Ptaszkiewicz, M.; Olko, P. [Henryk Niewodniczanski Institute of Nuclear Physics Polish Academy of Sciences, Department of Radiation Physics and Dosimetry, ul. Radzikowskiego 152, PL 31-342 Krakow (Poland); Berg, A.; Wieland, M. [Medizinische Universitaet Wien, Zentrum f. Biomedizinische Technik und Physik (Austria); Doran, S. [Department of Physics, University of Surrey, Guildford (United Kingdom); Kamlowski, A. [Bruker Biospin, Rheinstetten (Germany); Cellere, G. [DEI, Department of Information Engineering, via Gradenigo, 6/B, 35131 PADOVA (Italy) and Applied Materials Baccini Via Postumia Ovest, 244, 31050 San Biagio di Callalta, Treviso; Paccagnella, A. [DEI, Department of Information Engineering, via Gradenigo, 6/B, 35131 PADOVA (Italy); Siegbahn, E. A. [Department of Medical Physics, Karolinska Universitetssjukhuset, 17176 Stockholm (Sweden)

2010-07-23

103

High resolution analysis of satellite gradiometry  

NASA Technical Reports Server (NTRS)

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

Colombo, O. L.

1989-01-01

104

High resolution derivative spectra in remote sensing  

NASA Technical Reports Server (NTRS)

The use of derivative spectra is an established technique in analytical chemistry for the elimination of background signals and for resolving overlapping spectral features. Application of this technique for tackling analogous problems such as interference from soil background reflectance in the remote sensing of vegetation or for resolving complex spectra of several target species within individual pixels in remote sensing is proposed. Methods for generating derivatives of high spectral resolution data are reviewed. Results of experiments to test the use of derivatives for monitoring chlorosis in vegetation show that derivative spectral indices are superior to conventional broad-band spectral indices such as the near-infrared/red reflectance ratio. Conventional broad-band indices are sensitive to both leaf cover as well as leaf color. New derivative spectral indices which were able to monitor chlorosis unambiguously were identified. Potential areas for the application of this technique in remote sensing are considered.

Demetriades-Shah, Tanvir H.; Steven, Michael D.; Clark, Jeremy A.

1990-01-01

105

Improved methods for high resolution electron microscopy  

SciTech Connect

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.

Taylor, J.R.

1987-04-01

106

(Development of high spectral resolution lidar technology)  

SciTech Connect

The first year of this grant has been devoted to the design and construction of an upgraded version of the University of Wisconsin High Spectral Resolution Lidar (HSRL). The new system incorporates additional data channels to measure depolarization and multiple scattering in the lidar return. Schematic diagrams describing the new configurations are attached to this report. Increases in optical efficiency and receiver aperture, coupled with improvements in the stiffness and the thermal stability of the mechanical system are expected to significantly improve the performance of the instrument. Most components of the system are nearly completed and system integration is about to begin. The HSRL is committed to participate in the NASA FIRE cirrus experiment during November and December of this year. Our progress is completing HSRL subsystems is outlined in the following paragraphs. 3 figs.

Eloranta, E.W.

1991-07-30

107

Potential High Resolution Dosimeters For MRT  

NASA Astrophysics Data System (ADS)

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.

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

108

A high resolution solar atlas for fluorescence calculations  

NASA Technical Reports Server (NTRS)

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

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

1983-01-01

109

High resolution 2-D spectral analysis at low SNR  

Microsoft Academic Search

This paper presents a fully two-dimensional high-resolution spectral analysis technique. The method consists of extrapolating observed data beyond the observation window by means of 2-D least squares prediction filters. High-resolution spectral analysis is then obtained by a discrete Fourier transform of the extrapolated data. Previously, methods of obtaining a high-resolution spectrum analysis on 2-D data have applied 1-D high-resolution analyses

O. Frost

1980-01-01

110

Ecological applications of high resolution spectrometry  

NASA Technical Reports Server (NTRS)

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.

Lawrence, William T.

1989-01-01

111

High Resolution Spectroscopy to Support Atmospheric Measurements  

NASA Technical Reports Server (NTRS)

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.

Venkataraman, Malathy Devi

2006-01-01

112

High Resolution Airborne Shallow Water Mapping  

NASA Astrophysics Data System (ADS)

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).

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

2012-07-01

113

Stapes model using high-resolution ?CT  

NASA Astrophysics Data System (ADS)

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.

Baek, Jong Dae; Puria, Sunil

2008-02-01

114

Minimally invasive diagnostic imaging using high resolution Optical Coherence Tomography  

E-print Network

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

Herz, Paul Richard, 1972-

2004-01-01

115

Feasibility study of an avalanche photodiode readout for a high resolution PET with nsec time resolution  

SciTech Connect

A feasibility study for a high resolution positron emission tomograph, based on 9.5 x 4 x 4 mm{sup 3} LSO crystals viewed by 3 mm diameter avalanche photodiodes, has been carried out. Using a Na{sup 22} source the authors determined a spatial resolution of 2.3 {+-} 0.1 mm, an energy resolution around 15 % and a time resolution of 2.6 nsec. Possible configurations for larger scale tests and a tomograph are given.

Schmelz, C.; Ziegler, S. [Technische Univ. Muenchen (Germany). Nuklearmedizinische Klinik Rechts der Isar] [Technische Univ. Muenchen (Germany). Nuklearmedizinische Klinik Rechts der Isar; Bradbury, S.M.; Holl, I.; Lorenz, E. [Max-Planck-Inst. fuer Physik, Muenchen (Germany)] [Max-Planck-Inst. fuer Physik, Muenchen (Germany); Renker, D. [Paul Scherrer Inst., Villigen (Switzerland)] [Paul Scherrer Inst., Villigen (Switzerland)

1995-08-01

116

High resolution temperature insensitive interrogation technique for FBG sensors  

Microsoft Academic Search

In this letter, we propose a high resolution temperature insensitive interrogation technique for FBG sensors where one FBG acts as an edge filter to interrogate a separate FBG sensor. A high resolution of better than 5?? in strain measurement range from 0 to 1100?? and the best resolution of better than 1?? were verified by experiments. An error of only

Qiang Wu; Yuliya Semenova; An Sun; Pengfei Wang; Gerald Farrell

2010-01-01

117

High Resolution Temperature Insensitive Interrogation Technique for FBG Sensors  

Microsoft Academic Search

In this letter, we propose a high resolution temperature insensitive interrogation technique for FBG sensors where one FBG acts as an edge filter to interrogate a separate FBG sensor. A high resolution of better than 5 ?? in strain measurement range from 0 to 1100 ?? and the best resolution of better than 1 ?? were verified by experiments. An

Qiang Wu; Yuliya Semenova; An Sun; Pengfei Wang; Gerald Farrell

2009-01-01

118

High-Resolution Three-Dimensional Mapping of Semiconductor Dopant  

E-print Network

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

Dunin-Borkowski, Rafal E.

119

High resolution EUV monochromator/spectrometer  

SciTech Connect

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.

Koike, Masako (Moraga, CA)

1996-01-01

120

High resolution EUV monochromator/spectrometer  

DOEpatents

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.

Koike, Masako

1996-06-18

121

Investigation into High Spectral Resolution Lidar technologies  

NASA Astrophysics Data System (ADS)

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

Dawsey, Martha Wallis

122

Calibration of High Spectral Resolution Lidar  

NASA Astrophysics Data System (ADS)

NCAR's High spectral resolution lidar (HSRL) is a micro-pulse lidar system that is safe to deploy in populated urban areas and on airborne platforms. One of the unique features of the HSRL is the ability to simultaneously measure aerosol backscatter and extinction. HSRL separates molecular scattering from air molecules and cloud particle backscatter, based on their Doppler spectrum widths and from these signals backscatter cross-section and extinction profiles can be measured. Molecular scattering is used as a reference for estimating extinction. The HSRL simultaneously estimates individual backscatter from molecular and aerosol particles using broad and narrow Doppler spectrum widths, respectively. Absolute accuracy of the backscattered signals and their separation into molecular and aerosol scattering depends on spectral purity of the transmitted signals, accurate measurement of transmit power, and precise performance of filters. An end-to-end calibration procedure for accurately characterizing lidar measurements is essential for quality control of datasets. Path-integrated backscatter measurements are used for calibrating lidar observations. Lidar measurements in stratocumulus clouds with cloud droplets are used as a reference for calibration. Since, the HSRL independently estimates backscatter and extinction observations as a function of range, it is straightforward to compute the extinction to backscatter ratio (lidar ratio). As the lidar ratio for cloud droplet is a constant, measurements in stratocumulus cloud is used for calibrating the HSRL. In this paper an overview of calibration of the HSRL is presented. Calibration procedure based on path-integrated backscatter measurements and range resolved methods are compared.

Vivekanandan, J.; Eloranta, E.; Spuler, S.; Morley, B.

2012-04-01

123

Europa Ice Cliffs-High Resolution  

NASA Technical Reports Server (NTRS)

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.

1998-01-01

124

High Resolution IRON-57 Moessbauer Spectroscopy.  

NASA Astrophysics Data System (ADS)

Quantitative Mossbauer spectroscopic studies of multi-iron metalloproteins demand precise knowledge and control of the velocity of the radiation source and the intensity transmitted through the absorber at each velocity. Because these proteins yield Mossbauer spectra with overlapping lines, removing instrumental line broadening is essential for high resolution. Furthermore, the nonlinear transmitted intensity requires both accurate measurement and proper theoretical treatment to correctly apportion the intensity among the protein's iron atoms. This thesis details an original design and techniques for a spectrometer that allows this quantitative spectroscopy. We have developed a feedback control system for a Mossbauer velocity transducer that reduces instrumental broadening to less than 4% of a transition linewidth. Unique features of the system include a high gain, type 2 velocity feedback circuit and a driveshaft position regulating circuit that eliminates low frequency velocity drift. The velocity drive has an unmatched stability and reproducibility of (+OR-)1 (mu)m/sec. The nonlinearity of intensity with absorber strength stems from the blackness effect and the helicity dependence of transmission through a resonant absorber. A theory developed by M. Blume and O. C. Kistner characterizes transmission by a complex matrix index of refraction. We derive the ramifications of their formalism for several sample Hamiltonians. Our model for transmitted intensity further corrects for source self-resonance effects. We report a novel method for determining radiation source lineshapes, using a partially decayed source as both source and absorber. It requires no assumptions about absorber lineshape or uniformity among sources and thus improves on previous methods. The calibrated source lineshape allows us to accurately deconvolve transmission Mossbauer spectra, giving cross-sections linear in absorber strength. Further calibrations with thick stainless steel foils establish the ability of this spectrometer to linearize intensity up to an absorber optical density of 3. Finally, we report an upper limit to the E2/M1 mixing ratio in the 14.41 keV nuclear transition in ('57)Fe.

Filter, William Frederick

125

Single sensor processing to obtain high resolution color component signals  

NASA Technical Reports Server (NTRS)

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.

Glenn, William E. (Inventor)

2010-01-01

126

High Resolution Sensor for Nuclear Waste Characterization  

SciTech Connect

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.

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

2006-01-23

127

High Spatial Resolution Commercial Satellite Imaging Product Characterization  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

128

Sharpening high resolution information in single particle electron cryomicroscopy  

Microsoft Academic Search

Advances in single particle electron cryomicroscopy have made possible to elucidate routinely the structure of biological specimens at subnanometer resolution. At this resolution, secondary structure elements are discernable by their signature. However, identification and interpretation of high resolution structural features are hindered by the contrast loss caused by experimental and computational factors. This contrast loss is traditionally modeled by a

J. J. Fernndez; D. Luque; J. R. Castn; J. L. Carrascosa

2008-01-01

129

Meteorological utility of high resolution multispectral data  

NASA Technical Reports Server (NTRS)

There are no author-identified significant results in this report. This investigation is directed towards determining the meteorological information content of ERTS-1 MSS bulk data at 0.6 - 0.7 microns as a function of resolution. To accomplish this, the resolution of the MSS data is degraded incrementally to 0.5 min. Subsequent analysis of the processed photographs in conjunction with surface and upper air observations will then determine to what extent significant meteorological information has been lost in the degradation process.

Danko, J. M. (principal investigator)

1973-01-01

130

High-resolution two-dimensional spectral analysis  

Microsoft Academic Search

Until recently most high-resolution autoregressive spectral analysis techniques have been applied to analysis of either single-channel waveforms or multichannel vector processes. However, the use of data prediction autoregressive spectral analysis permits the application of some high-resolution single-channel methods to high-resolution spectral analysis of data fields in two or more dimensions. The technique consists of extrapolating observed data beyond the observation

O. Frost; T. Sullivan

1979-01-01

131

High resolution, high rate x-ray spectrometer  

DOEpatents

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.

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

1983-07-14

132

High Resolution Velocity Structure in Eastern Turkey  

SciTech Connect

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.

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

2004-09-03

133

High resolution optics combined with high spatial reproducibility in flow  

SciTech Connect

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

Eisert, W.G.

1981-01-01

134

High resolution quantitation of microvascular plasma perfusion in non-ischemic and ischemic rat brain by laser-scanning confocal microscopy.  

PubMed

Laser-scanning confocal microscopy (LSCM) was used to measure at high resolution cerebral plasma volumes (perfusion) using two fluorescent plasma markers in a rat model of embolic stroke. This application of LSCM to study the microvascular circulation in embolic stroke was developed as an alternative to autoradiography to measure cerebral perfusion. An additional benefit of LSCM is that it quantitates with great accuracy the structural relationships of the microcirculation to cells and the pathological alterations of the ischemic brain. Autoradiography allows only a quantitative analysis of cerebral perfusion. For example, in order to study the microcirculation and its relationship to blood brain barrier damage, the volume of perfused cerebral capillaries was measured by administering two fluorescent plasma markers (FITC-dextran and Evans blue) intravenously to a rat. Evans blue was administered before cerebral ischemia and FITC-dextran administered post-ischemia 1 min before sacrifice. Volumes of plasma perfusion were analyzed by means of a system developed for 3D analysis of fixed and stained serial brain histologies. Plasma volumes for the non-ischemic cerebral cortex were 1.00%+/-0.38% while plasma volumes in the caudate/putamen were 0.69%+/-0.17% in good agreement with the previously published values using the autoradiography method. The architecture of the capillaries in the ischemic core showed perfusion of Evans blue but there was no flow of FITC dextran. Our work represents a novel application of this technology to investigation of cerebral vascular disease and identifies its potential to become an important tool for investigation of cerebral pathology. PMID:10446413

Morris, D C; Zhang, Z; Davies, K; Fenstermacher, J; Chopp, M

1999-07-01

135

Initialisation using high spatial, temporal and spectral resolution satellite observations  

NASA Astrophysics Data System (ADS)

Recent advances in numerical weather prediction and data assimilation, combined with the availability of high spatial, temporal and spectral resolution satellite observations and burgeoning computer power are leading to significant improvements in our ability to predict weather phenomena at higher and more appropriate resolutions. Here, we describe recent work, illustrating such improvements. High spatial and temporal (at least hourly) resolution data from sequential geostationary multispectral imagery have been used to initialise a high resolution (15km) 4-D variational assimilation (4-D Var.) system to improve tropical cyclone track prediction. The same wind data, sometimes with the addition of TOVS data from NOAA operational satellites, have also been used at higher resolution (5km) to estimate tropical cyclone intensity, demonstrating the importance of very high resolution modelling and data for this enterprise. Finally, we are using very high resolution (1km) 4-D Var. with very high spatial temporal and spectral resolution observations available from experimental advanced sounder instruments such as the High resolution Interferometer Sounder (HIS) and the NPOESS Aircraft Sounder Testbed - Interferometer (NAST - I) to examine the impact after initialisation of the improved delineation of the thermal and moisture fields by these next-generation sounders. This we believe is the first use of advanced sounder data with 4-D Var. and will assist in exploiting such data from the experimental Advanced Infrared Sounder (AIRS), the operational Infrared Atmospheric Sounding Interferometer (IASI), the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) and Cross-track Interferometer Sounder (CrIS) instruments.

Le Marshall, J. F.; Leslie, L. M.; Smith, W. L.

136

GEOMETRIC ACCURACY OF HIGH-RESOLUTION DATA FOR URBAN PLANNING  

Microsoft Academic Search

The very high-resolution satellite data from IKONOS and QuickBird are in a competition to aerial images today. Although the IKONOS satellite has provided the world's first source of commercially available high-resolution satellite imagery, QuickBird is currently the satellite with the highest resolution for civilian uses. While the IKONOS and QuickBird panchromatic band images with 0.82 and 0.61 meter respectively, provide

F. YA?A; F. Sunar ERBEK; A. ULUBAY; C. ZKAN

137

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

E-print Network

High resolution simulation of the South Asian monsoon using a variable resolution global climate understand regional aspects of the South Asian monsoon rainfall distribution and the interactions between monsoon circulation and precipitation. For this purpose, two sets of ten member realizations are produced

Hourdin, Chez Frédéric

138

High resolution, high bandwidth global shutter CMOS area scan sensors  

NASA Astrophysics Data System (ADS)

Global shuttering, sometimes also known as electronic shuttering, enables the use of CMOS sensors in a vast range of applications. Teledyne DALSA Global shutter sensors are able to integrate light synchronously across millions of pixels with microsecond accuracy. Teledyne DALSA offers 5 transistor global shutter pixels in variety of resolutions, pitches and noise and full-well combinations. One of the recent generations of these pixels is implemented in 12 mega pixel area scan device at 6 um pitch and that images up to 70 frames per second with 58 dB dynamic range. These square pixels include microlens and optional color filters. These sensors also offer exposure control, anti-blooming and high dynamic range operation by introduction of a drain and a PPD reset gate to the pixel. The state of the art sense node design of Teledyne DALSA's 5T pixel offers exceptional shutter rejection ratio. The architecture is consistent with the requirements to use stitching to achieve very large area scan devices. Parallel or serial digital output is provided on these sensors using on-chip, column-wise analog to digital converters. Flexible ADC bit depth combined with windowing (adjustable region of interest, ROI) allows these sensors to run with variety of resolution/bandwidth combinations. The low power, state of the art LVDS I/O technology allows for overall power consumptions of less than 2W at full performance conditions.

Faramarzpour, Naser; Sonder, Matthias; Li, Binqiao

2013-10-01

139

Observations and Uses of High Resolution Radar Data from Precipitation  

Microsoft Academic Search

The benefits of very high resolution data from scanning and vertically pointing radars in a research and operational environment are investigated. They are used to perform research on four test topics: the study of the melting layer of precipitation, the derivation of vertical wind profiles using conventional radars, high resolution radar hydrology, and a case study of an unusual weather

Frederic Fabry

1994-01-01

140

High resolution seismic tomography of a Strombolian volcanic cone  

Microsoft Academic Search

We determine the 3D velocity structure of the Puy des Goules, a small, 1 km wide, Strombolian volcano that erupted 10 ky ago in central France, through a high resolution seismic survey. One major goal for this experiment was to develop methods to reach a high resolution focused on the plumbing system. This has raised different problems such as: mixing

F. Brenguier; O. Coutant; H. Baudon; F. Dor; M. Dietrich

2006-01-01

141

STATUS OF HIGH RESOLUTION SOLAR IRRADIANCE MAPPING FROM SATELLITE DATA  

E-print Network

STATUS OF HIGH RESOLUTION SOLAR IRRADIANCE MAPPING FROM SATELLITE DATA Richard Perez & Marek Vignola Solar Energy Laboratory University of Oregon Eugene, OR 97403 fev@darkwing.uoregon.edu Pierre presents examples of high resolution solar radiation maps generated from satellite data using the semi

Perez, Richard R.

142

Medusae Fossae Formation - High Resolution Image  

NASA Technical Reports Server (NTRS)

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.

1998-01-01

143

High resolution radar map of the Moon  

NASA Technical Reports Server (NTRS)

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.

Thompson, T. W.

1987-01-01

144

High Resolution LTS-SQUID Microscopes  

NASA Astrophysics Data System (ADS)

We have developed a scanning superconducting quantum interference device (SQUID) microscope for imaging magnetic fields of room-temperature samples with sub-millimeter resolution. In our design, hand wound niobium pickup coils were coupled to commercially available low-temperature SQUID sensors. The SQUID sensor and the pickup coil are in the vacuum space of the cryostat separated typically less than 50?m by a thin sapphire window from the room-temperature sample. A computerized non-magnetic scanning stage with sub-micron resolution in combination with a tripod leveling system allows samples to be scanned within 10?m of the sapphire window. For a 20-turn 500?m diameter pickup coil, we achieved a field sensitivity of 350fT\\cdotHz-1/2 for frequencies above 1 Hz, and 1pT\\cdotHz-1/2 for a 10-turn 250mm coil. The SQUID microscope was used to image the distribution of time-dependent stimulus and action currents in anisotropic cardiac tissue, the remanent magnetization of the Martian meteorite ALH84001 during thermal demagnetisation, and the magnetic susceptibility of biogenic magnetite in the beak of homing pigeons.

Baudenbacher, Franz; Peters, Nicholas; Wikswo, John

2000-03-01

145

High Resolution X-ray Imaging  

NASA Technical Reports Server (NTRS)

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.

Cash, Webster

2002-01-01

146

Survey of currently available high-resolution raster graphics systems  

NASA Technical Reports Server (NTRS)

Presented are data obtained on high-resolution raster graphics engines currently available on the market. The data were obtained through survey responses received from various vendors and also from product literature. The questionnaire developed for this survey was basically a list of characteristics desired in a high performance color raster graphics system which could perform real-time aircraft simulations. Several vendors responded to the survey, with most reporting on their most advanced high-performance, high-resolution raster graphics engine.

Jones, Denise R.

1987-01-01

147

High Spectral Resolution With Multilayer Gratings  

SciTech Connect

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.

Andre, J.-M.; Le Guen, K.; Jonnard, P. [Laboratoire de Chimie Physique-Matiere et Rayonnement, Universite Pierre et Marie Curie, CNRS UMR 7614, 11 rue Pierre et Marie Curie, F-75231 Paris Cedex 05 (France)

2010-04-06

148

High resolution self-mixing laser rangefinder.  

PubMed

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

Norgia, M; Magnani, A; Pesatori, A

2012-04-01

149

The high spectral resolution (scanning) lidar (HSRL)  

SciTech Connect

Lidars enable the spatial resolution of optical depth variation in clouds. The optical depth must be inverted from the backscatter signal, a process which is complicated by the fact that both molecular and aerosol backscatter signals are present. The HSRL has the advantage of allowing these two signals to be separated. It has a huge dynamic range, allowing optical depth retrieval for t = 0.01 to 3. Depolarization is used to determine the nature of hydrometeors present. Experiments show that water clouds must almost always be taken into account during cirrus observations. An exciting new development is the possibility of measuring effective radius via diffraction peak width and variable field-of-view measurements. 2 figs.

Eloranta, E. [Univ. of Wisconsin, Madison, WI (United States)

1995-09-01

150

A high resolution global scale groundwater model  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

151

A high resolution global scale groundwater model  

NASA Astrophysics Data System (ADS)

As the world's largest accessible source of freshwater, groundwater plays a vital role in satisfying the basic needs of human society. It serves as a primary source of drinking water and supplies water for agricultural and industrial activities. During times of drought, groundwater storage provides a large natural buffer against water shortage and sustains flows to rivers and wetlands, supporting ecosystem habitats and biodiversity. Yet, the current generation of global scale hydrological models (GHMs) do not include a groundwater flow component, although it is a crucial part of the hydrological cycle. Thus, a realistic physical representation of the groundwater system that allows for the simulation of groundwater head dynamics and lateral flows is essential for GHMs that increasingly run at finer resolution. In this study we present a global groundwater model with a resolution of 5 arc-minutes (approximately 10 km at the equator) using MODFLOW (McDonald and Harbaugh, 1988). With this global groundwater model we eventually intend to simulate the changes in the groundwater system over time that result from variations in recharge and abstraction. Aquifer schematization and properties of this groundwater model were developed from available global lithological maps and datasets (Drr et al., 2005; Gleeson et al., 2010; Hartmann and Moosdorf, 2013), combined with our estimate of aquifer thickness for sedimentary basins. We forced the groundwater model with the output from the global hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the net groundwater recharge and average surface water levels derived from routed channel discharge. For the parameterization, we relied entirely on available global datasets and did not calibrate the model so that it can equally be expanded to data poor environments. Based on our sensitivity analysis, in which we run the model with various hydrogeological parameter settings, we observed that most variance in groundwater depth is explained by variation in saturated conductivity, and, for the sediment basins, also by variation in recharge. We validated simulated groundwater heads with piezometer heads (available from www.glowasis.eu), resulting in a coefficient of determination for sedimentary basins of 0.92 with regression constant of 0.8. This shows the used method is suitable to build a global groundwater model using best available global information, and estimated water table depths are within acceptable accuracy in many parts of the world.

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

2014-05-01

152

GLASS CERAMICS FOR HIGH RESOLUTION IMAGING  

SciTech Connect

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

Johnson, Jackie A. [University of Tennessee Space Institute; Weber, Rick [Materials Development, Inc., Evanston, IL; Kolesnikov, Alexander I [ORNL; SCHWEIZER, Stefan [Fraunhofer Center for Silicon Photovoltaics, 06120 Halle, Germany

2008-01-01

153

High-resolution tomographic imaging of microvessels  

NASA Astrophysics Data System (ADS)

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.

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

2008-08-01

154

Algorithms for automatic interpretation of high resolution mass spectra  

Microsoft Academic Search

Automated interpretation of high-resolution mass spectra in a reliable and efficient manner represents a highly challenging\\u000a computational problem. This work aims at developing methods for reducing a high-resolution mass spectrum into its monoisotopic\\u000a peak list, and automatically assigning observed masses to known fragment ion masses if the protein sequence is available.\\u000a The methods are compiled into a suite of data

Parminder Kaur; Peter B. OConnor

2006-01-01

155

High resolution Auger electron imaging of supported metal particles  

Microsoft Academic Search

High spatial resolution Auger electron spectra and images of supported metal particles have been obtained in a UHV scanning transmission electron microscope. An edge resolution < 3 nm has been achieved. The number of atoms in a small particle can be estimated from the integrated intensity of the Auger electrons. This method is very useful for detecting and measuring particles

J. Liu; G. G. Hembree; G. E. Spinnler; J. A. Venables

1992-01-01

156

High resolution SPH simulations of merging white dwarfs binary systems  

Microsoft Academic Search

We present the results of a series of high-resolution Smoothed Particle Hydrodynamics (SPH) simulations of merging white dwarfs. Our basic goals are to increase the resolution of the existing simulations in order to assess the reliability of the existing results, to explore a complete set of initial conditions and to study a wide enough range of masses of the coalescing

P. Loren

2007-01-01

157

Ultrastable reference pulser for high-resolution spectrometers  

NASA Technical Reports Server (NTRS)

Solid-state double-pulse generator for a high resolution semiconductor detector meets specific requirements for resolution /0.05 percent/, amplitude range /0.1-13 MeV/, and repetition rate /0.1-1000 pulses per second/. A tag pulse is generated in coincidence with each reference pulse.

Brenner, R.; Lenkszus, F. R.; Sifter, L. L.; Strauss, M. G.

1970-01-01

158

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

NASA Astrophysics Data System (ADS)

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.

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

159

A high resolution global scale groundwater model  

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

160

High Resolution Laboratory Spectroscopy of Fullerenes in Support of SOFIA  

NASA Astrophysics Data System (ADS)

Our objective is to obtain the first high-resolution (rotationally-resolved) absorption rotation- vibration spectrum of gas phase C60 and C70 in the mid infrared. The gas phase fullerenes will be prepared at low temperature using a supersonic expansion of a supercritical fluid (mixture of CO2 and toluene) containing dissolved fullerenes. The samples will be probed using a widely tunable but narrow linewidth external-cavity quantum cascade laser, along with the high sensitivity technique of high-repetition-rate cavity ringdown spectroscopy. This work is intended to support (and, indeed, enable) spectroscopy of interstellar fullerenes using the EXES high-resolution spectrometer on SOFIA. While interstellar fullerenes have been widely reported in emission through low-resolution spectroscopy with Spitzer, high-resolution absorption spectroscopy with EXES/SOFIA would provide more detailed information about their column density and excitation. This, in turn, would provide important insight into the production of these large carbonaceous molecules.

McCall, Benjamin

161

Spatially adaptive regularized iterative high-resolution image reconstruction algorithm  

NASA Astrophysics Data System (ADS)

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.

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

2000-12-01

162

Sensitivity study of reliable, high-throughput resolution metricsfor photoresists  

SciTech Connect

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.

Anderson, Christopher N.; Naulleau, Patrick P.

2007-07-30

163

Fabrication of high-resolution micropolarizer arrays  

E-print Network

films involving selective bleaching, se- lective iodine/potassium iodide indiffusion, or selective laser beam bleaching of polarization film.12 A focused laser beam can bleach the dichroic dye molecules in the polymer matrix to make individual polarizing elements. Using laser beam bleaching to transfer a high

Guo, Junpeng

164

Compressive Sensing Based High Resolution Channel Estimation ...  

E-print Network

We first provide the motivation, as well as the CS ... motivated to apply CS to recover a high-dimensional h from ..... It is a standard exercise to obtain the overall CRLB: .... detection for wireless ICI self-cancellation coded OFDM systems, IEEE.

2011-09-17

165

Assessment of Very High Spatial Resolution Satellite Image Segmentations  

Microsoft Academic Search

Since 1999, very high spatial resolution satellite data represent the surface of the Earth with more detail. How- ever, information extraction by per pixel multispectral classification techniques proves to be very complex owing to the internal

A. P. Carleer; O. Debeir; E. Wolff

166

High resolution non-contact thermal characterization of semiconductor devices  

E-print Network

High resolution non-contact thermal characterization of semiconductor devices James Christoffersona surface thermal characterization of active semiconductor devices. Point measurements were first made of 50mK. Key words: Thermal Imaging, Thermoreflectance, Semiconductor Imaging, 1. INTRODUCTION

167

Techniques for Fabricating High Resolution Liquid Crystal Reticles.  

National Technical Information Service (NTIS)

The overall objective of this two-phase program was to develop techniques for fabricating high resolution liquid crystal reticles suitable for military application. The first phase of this program consisted of three technology development tasks, namely su...

B. C. Gilbert

1979-01-01

168

Techniques for Fabricating High Resolution Liquid Crystal Reticles.  

National Technical Information Service (NTIS)

The overall objective of this two-phase program was to develop techniques for fabricating high resolution liquid crystal reticles suitable for military application. The first phase of this program consisted of three technology development tasks, namely su...

W. Stokes, D. Rey, J. L. Thompson

1980-01-01

169

High Resolution Imaging of Circumstellar Disks at Millimeter Wavelengths  

NASA Technical Reports Server (NTRS)

We summarize progress on our program to use high angular resolution imaging of thermal dust continuum emission at millimeter and submillimeter wavelengths to probe the structure of protoplanetary disks and debris disks around nearby stars.

Wilner, David J.

2004-01-01

170

High-resolution contact lithography by excimer lasers  

NASA Astrophysics Data System (ADS)

High-resolution contact lithography was conducted by both 248-nm KrF and 193-nm ArF excimer lasers on PMMA resist. The resist thickness is about 0.5 (mu) . Resolution of 0.5- (mu) lines and spaces was obtained on PMMA resist after KrF excimer laser exposure and subsequent wet development. No self-developing photoetching was observed. However, with ArF excimer laser as the exposure light source, resolution of 0.3-(mu) lines and spaces was obtained on the same resist by direct photoetching under high exposure dose combined with subsequent conventional wet developing process.

Huang, Huijie; Lu, Dunwu; Du, Longlong; Zhao, Yongkai; Yuan, Cailai; Jiang, Baocai; Wang, Runwen

2000-11-01

171

Towards a High-Resolution Global Coupled Navy Prediction System  

Microsoft Academic Search

The focus of our recent work has been to complete the global high-resolution ocean and the eddy-permitting coupled ice\\/ocean simulations using the Los Alamos Parallel Ocean Program (POP) model and the sea ice model (CICE), as well as the first reanalysis using the Simple Ocean Data Assimilation (SODA) and POP (SODA POP 1.2). The high-resolution (0.1degree) global ocean model was

Julie L. McClean; Detelina Ivanova; P. Thoppill; M. Maltrud; E. Hunke; W. Lipscomb; J. Carton; B. Giese

2005-01-01

172

Towards a high-resolution global coupled navy prediction system  

Microsoft Academic Search

A fully coupled global atmosphere-ocean prediction system for short-term forecasting has been developed at NRL Monterey at modestly high horizontal resolution (0.5 ocean and 0.75 atmosphere). University and national laboratory partners are performing coupled ice\\/ocean simulations, improving the data assimilation scheme, and running high-resolution ocean simulations with the goal of advancing this prediction system. Sea ice in the 0.4 global

Julie L. McClean; Prasad Thoppil; Detelina Ivanova; Donald Stark; Mathew Maltrud; E. Hunke; P. May; J. Carton; B. Giese

2004-01-01

173

NIR high-resolution imaging of young stars  

Microsoft Academic Search

High resolution imaging of young stellar objects (YSOs) in the near-infrared wavelength region (NIR) can reveal the spatial distribution of warm circumstellar dust as well as the multiplicity of the sources. We investigated a sample of southern Herbig Ae\\/Be stars, Vega-type stars, and a region in the Hourglass nebula with high spatial resolution. For most of the objects, the observations

B. Stecklum; Th. Henning; A. Eckart; R. Hofmann

1994-01-01

174

Traffic Surveillance System Based on a High-Resolution Radar  

Microsoft Academic Search

Traffic surveillance is an important civilian application of radars. The current high-resolution radars give new opportunities so that the traffic application may be redefined. In this paper, a traffic scenario with a high-resolution radar is presented. A range-bin alignment method, the Global Range Alignment, which comes from the focusing techniques in inverse synthetic aperture radar, is applied to obtain further

J. M. Munoz-Ferreras; F. Perez-Martinez; J. Calvo-Gallego; A. Asensio-Lopez; B. P. Dorta-Naranjo; A. Blanco-Del-Campo

2008-01-01

175

High Resolution Electron Microscopy at the National Cancer Institute  

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 ion beam to remove slices of the sample, resulting in a sequential stack of high resolution images.

176

Utilizing high resolution and reconfigurable patterns in combination with inkjet printing to produce high performance circuits  

NASA Astrophysics Data System (ADS)

Inkjet printing on pre-fabricated high-resolution substrate is developed to improve the operational speed of printed organic transistors. The high-resolution features are designed to define transistor critical dimensions, while maintaining the flexibility to incorporate different circuit constructions. Logic gate and ring oscillator circuits fabricated by inkjet printing on the high-resolution substrate are demonstrated, to show that the same high resolution pattern can be adapted for constructing different electronic circuits.

Mei, P.; Ng, T. N.; Lujan, R. A.; Schwartz, D. E.; Kor, S.; Krusor, B. S.; Veres, J.

2014-09-01

177

High-resolution signal synthesis for time-frequency distributions  

SciTech Connect

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.

Cunningham, G.S. [Los Alamos National Lab., NM (United States); Williams, W.J. [Michigan Univ., Ann Arbor, MI (United States). Dept. of Electrical Engineering and Computer Science

1993-03-01

178

High-resolution signal synthesis for time-frequency distributions  

SciTech Connect

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.

Cunningham, G.S. (Los Alamos National Lab., NM (United States)); Williams, W.J. (Michigan Univ., Ann Arbor, MI (United States). Dept. of Electrical Engineering and Computer Science)

1993-01-01

179

High-resolution Urban Image Classification Using Extended Features  

SciTech Connect

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.

Vatsavai, Raju [ORNL] [ORNL

2011-01-01

180

Potential For High Resolution Microscintigraphy using Polycapillary Optics  

NASA Astrophysics Data System (ADS)

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.

Conlon, Patrick

181

High-resolution studies of protoplanetary disks  

NASA Astrophysics Data System (ADS)

This work presents a multiwavelength search (near-IR, mid-IR, mm) for previously unknown circumstellar disks and a study of those disk candidate objects which are not jet well characterised in the literature. 22 candidate stars, most of these constituting known exoplanet systems, were examined for circumstellar material using the Adaptive Optics instrument ADONIS at La Silla Observatory (Chile). With the new Adaptive Optics system NAOS-CONICA at Paranal (Chile) we tested the technique of Polarimetric Differential Imaging. Advances in mid-IR data reduction were achieved, e.g., a method was developed to correct the chromatic and airmass dependent extinction. We show new N-band photometry and spectra for eight pre-main sequence stars, six main sequence stars and one post-MS object using the TIMMI2 camera at La Silla, and model the emission spectra with a mixture of silicates consisting of different grain sizes and composition. The most important result thereof is the discovery of two previously unknown circumstellar disks around HD 72106 and HD 113766. Both objects are host to highly processed silicates, resembling those found in solar-system comets. We further present the first observational confirmation for an extended circumstellar dust disk around ? Eri obtained with the bolometer array SIMBA at the 15 m radio telescope SEST in La Silla and demonstrate that the previously claimed disk substructure may alternatively be explained by remnant noise effects.

Schtz, Oliver

2005-02-01

182

New approach to 3-D, high sensitivity, high mass resolution space plasma composition measurements  

Microsoft Academic Search

This paper describes a new type of 3-D space plasma composition analyzer. The design combines high sensitivity, high mass resolution measurements with somewhat lower mass resolution but even higher sensitivity measurements in a single compact and robust design. While the lower resolution plasma measurements are achieved using conventional straight-through time-of-flight mass spectrometry, the high mass resolution measurements are made by

David J. McComas; Jane E. Nordholt

1990-01-01

183

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

PubMed

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

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

2013-08-01

184

High-resolution climate simulation of the last glacial maximum  

SciTech Connect

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.

Erickson III, David J [ORNL

2008-01-01

185

High-energy resolution alpha spectrometry using cryogenic detectors.  

PubMed

Applications such as environment monitoring implying alpha emitters activity measurement associated with isotope identification, require high-energy resolution detectors. Conventional silicon detectors are inexpensive therefore widely used, although intrinsically limited in energy resolution. Thermal detection principle of cryogenic detectors introduces a breakthrough in alpha particle measurement. For the first time, spectra with 5.5 keV FWHM energy resolution have been obtained for several external alpha emitting sources using a copper-germanium bolometer specially developed for alpha spectrometry. PMID:16618545

Leblanc, E; Coron, N; Leblanc, J; de Marcillac, P; Bouchard, J; Plagnard, J

2006-01-01

186

High spectral resolution multiplex CARS spectroscopy using chirped pulses  

NASA Astrophysics Data System (ADS)

A simple technique for achieving high spectral resolution coherent anti-Stokes Raman scattering (CARS) spectra with a femtosecond laser system is presented. A linearly chirped and stretched (10 ps) pump pulse generates CARS signal only when overlapped in time with the Stokes pulse (90 fs), creating a `temporal slit' that defines the spectral resolution of the technique. Multiplex CARS spectra for liquid methanol and liquid isooctane are presented, demonstrating a spectral resolution of better than 5 cm -1. This new chirped (c-CARS) technique should prove useful for chemically-selective imaging applications, as it significantly reduces the non-resonant background contribution.

Knutsen, K. P.; Johnson, J. C.; Miller, A. E.; Petersen, P. B.; Saykally, R. J.

2004-04-01

187

Identifying new opportunities for exoplanet characterisation at high spectral resolution  

NASA Astrophysics Data System (ADS)

Context. Recently, there have been a series of detections of molecules in the atmospheres of extrasolar planets using high spectral resolution (R ~ 100 000) observations, mostly using the CRyogenic high-resolution InfraRed Echelle Spectrograph (CRIRES) on the Very Large Telescope. These measurements are able to resolve molecular bands into individual absorption lines. Observing many lines simultaneously as their Doppler shift changes with time allows the detection of specific molecules in the atmosphere of the exoplanet. Aims: We aim to identify new ways of increasing the planet signal in these kinds of high-resolution observations. First of all, we wish to determine what wavelength settings can best be used to target certain molecules. Furthermore, we want to simulate exoplanet spectra of the day-side and night-side to see whether night-side observations are feasible at high spectral resolution. Methods: We performed simulations of high-resolution CRIRES observations of a planet's thermal emission and transit between 1 and 5 ?m and performed a cross-correlation analysis on these results to assess how well the planet signal can be extracted. These simulations take into account telluric absorption, sky emission, realistic noise levels, and planet-to-star contrasts. We also simulated day-side and night-side spectra at high spectral resolution for planets with and without a day-side temperature inversion, based on the cases of HD 189733b and HD 209458b. Results: Several small wavelength regions in the L-band promise to yield cross-correlation signals from the thermal emission of hot Jupiters of H2O, CH4, CO2, C2H2, and HCN that can exceed those of the current detections by up to a factor of 2-3 for the same integration time. For transit observations, the H-band is also attractive, with the H, K, and L-bands giving cross-correlation signals of similar strength. High-resolution night-side spectra of hot Jupiters can give cross-correlation signals as high as the day-side, or even higher. Conclusions: We show that there are many new possibilities for high-resolution observations of exoplanet atmospheres that have expected planet signals at least as high as those already detected. Hence, high-resolution observations at well-chosen wavelengths and at different phases can improve our knowledge about hot Jupiter atmospheres significantly, already with currently available instrumentation.

de Kok, R. J.; Birkby, J.; Brogi, M.; Schwarz, H.; Albrecht, S.; de Mooij, E. J. W.; Snellen, I. A. G.

2014-01-01

188

Research using high (and higher) resolution radiosonde data  

NASA Astrophysics Data System (ADS)

High vertical resolution radiosonde data (HVRRD), which began to become available in the early 1990s, have had value in gravity wave and tropical wave studies [Hamilton and Vincent, 1995]. For example, routine analysis of upper troposphere-lower stratosphere temperature and wind has led to better understanding of seasonal and geographic variations in gravity wave activity and spectral characteristics. Since then, HVRRD have been exploited for much broader research applications in fields where HVRRD provide the highest resolution available for observational parameters. With recent upgrades to the National Oceanic Atmospheric Administration's (NOAA) network of U.S. upper air stations providing yet higher vertical resolution, new research applications of operational sounding data are emerging. A repository of long-term, routine, very high resolution in situ observations of fundamental atmospheric parameters, including temperature, water vapor, and wind velocity, is now available, for which the full research potential has yet to be realized.

Love, Peter T.; Geller, Marvin A.

2012-08-01

189

A procedure for high resolution satellite imagery quality assessment.  

PubMed

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

Crespi, Mattia; De Vendictis, Laura

2009-01-01

190

Performance of a High Resolution Cavity Beam Position Monitor System  

SciTech Connect

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.

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,

2007-06-08

191

Performance of a High Resolution Cavity Beam Position Monitor System  

SciTech Connect

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.

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

192

High-spectral-resolution multiplex CARS spectroscopy using chirped pulses  

NASA Astrophysics Data System (ADS)

A novel technique for achieving high spectral resolution with a femtosecond laser system is presented. Transform-limited 800 nm, 90 femtosecond (fs) pulses pass off two gratings, stretching the pulse in time to a pulse width of several picoseconds due to an induced linear temporal chirp directly proportional to the grating separation. This chirped pulse is the degenerate pump (?P) and probe (?p) pulse for the CARS experiment. When overlapped in time with the 1050 nm, 90 fs transform-limited Stokes (?S) pulse, only a fraction of the chirped ?p pulse generates the CARS signal, thereby creating a temporal slit that defines the spectral resolution of the technique. Spectra for liquid methanol and liquid isooctane are presented, with ~6 cm-1 spectral resolution achieved for isooctane. Resonance enhancement and the mechanism of achieving high spectral resolution are shown by adjusting the ?S wavelength and ?p delay relative to the ?S pulse.

Knutsen, Kelly P.; Johnson, Justin C.; Miller, Abigail E.; Petersen, Poul B.; Saykally, Richard J.

2004-06-01

193

Reflection Mode Imaging with High Resolution X-rayMicroscopy  

SciTech Connect

We report on the first demonstration of imaging microstructures with soft x-ray microscopy operating in reflection geometry. X-ray microscopy in reflection mode combines the high resolution available with x-ray optics, the ability to image thick samples, and to directly image surfaces and interfaces. Future experiments with this geometry will include tuning the incident angle to obtain depth resolution. In combination with XMCD as magnetic contrast mechanism this mode will allow studies of deep buried magnetic interfaces.

Denbeaux, Greg; Fischer, Peter; Salmassi, Farhad; Dunn, Kathleen; Evertsen, James

2005-04-02

194

High resolution XPS characterization of chemical functionalised MWCNTs and SWCNTs  

Microsoft Academic Search

High resolution XPS analysis of chemical functionalised multi-wall carbon nanotubes (MWCNTs) and single wall carbon nanotubes (SWCNT) was done with ESCA300 (overall instrument resolution of 0.35eV). Information to the degree of functionalisation was ascertained by argon ion bombardment of the samples followed by XPS analysis to detect the functional groups, the percentage atomic concentration of various elements present and whether

T. I. T. Okpalugo; P. Papakonstantinou; H. Murphy; J. McLaughlin; N. M. D. Brown

2005-01-01

195

High-resolution global upper mantle structure and plate tectonics  

Microsoft Academic Search

A global high-resolution S wave velocity model RG5.5 is obtained for the upper 500 km of Earth's mantle using a 5 x 5 deg equal-area block parameterization. The data set consists of some 18,000 seismograms associated with 971 events with magnitudes larger than 5.5. Fundamental modes are used with periods from 75 to 250 s. The horizontal resolution length is

Yu-Shen Zhang; Toshiro Tanimoto

1993-01-01

196

In vivo fluorescence imaging with high-resolution microlenses  

PubMed Central

Micro-optics are increasingly used for minimally invasive in vivo imaging, in miniaturized microscopes and in lab-on-a-chip devices. Owing to optical aberrations and lower numerical apertures, a main class of microlens, gradient refractive index lenses, has not achieved resolution comparable to conventional microscopy. Here we describe high-resolution microlenses, and illustrate two-photon imaging of dendritic spines on hippocampal neurons and dual-color nonlinear optical imaging of neuromuscular junctions in live mice. PMID:19525959

Barretto, Robert P J; Messerschmidt, Bernhard; Schnitzer, Mark J

2010-01-01

197

Digital pulse processing in high resolution, high throughput, gamma-ray spectroscopy  

Microsoft Academic Search

A new method for processing signals produced by high resolution, large volume semiconductor detectors is described. These detectors, to be used in the next generation of spectrometer arrays for nuclear research (i.e., EUROBALL, etc.), present a set of problems, such as resolution degradation due to charge trapping and ballistic deficit effects, poor resolution at a high count rate, long term

Andrey Georgiev; Werner Gast

1993-01-01

198

Studying Thermoelectric Oxides using High-Resolution Scanning Transmission Electron Figure 4: a) Atomic resolution Z-  

E-print Network

Studying Thermoelectric Oxides using High-Resolution Scanning Transmission Electron Microscopy 0 the environmental impact, and deliver energy continuously, such as thermo-electric power generation, have often been overlooked. Thermo-electric (TE) power applications offer a potentially cheap, pollution- and maintenance

Ben-Arie, Jezekiel

199

High resolution photolithography with sub-wavelength grating  

NASA Astrophysics Data System (ADS)

Based on the theory of surface plasmon resonance and the special nano-optical effect of metal/dielectric multilayer composites, we obtained a high-resolution image of a sub-wavelength grating. We discussed multilayer parameters on equal thickness, and achieved sufficient contrast and high intensity through numerical simulation based on the finite element method. By chosen the best scheme, an experimental of multilayer planar lens lithography has been carried out. The main point is the use of metal-dielectric composites to realize high-resolution image under 365-nm polarization light incidence. By controlling the experimental parameters accurately, a fidelity image is recorded on the photoresist.

Zhao, Qing; Liang, Gaofeng; Wang, Changtao; Huang, Xiaoping; Chen, Zexiang; Luo, Xiangang

2014-04-01

200

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

PubMed Central

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

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

201

Evacuee Compliance Behavior Analysis using High Resolution Demographic Information  

SciTech Connect

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.

Lu, Wei [ORNL] [ORNL; Han, Lee [University of Tennessee, Knoxville (UTK)] [University of Tennessee, Knoxville (UTK); Liu, Cheng [ORNL] [ORNL; Tuttle, Mark A [ORNL] [ORNL; Bhaduri, Budhendra L [ORNL] [ORNL

2014-01-01

202

Large-field high-resolution mosaic movies  

NASA Astrophysics Data System (ADS)

Movies with fields-of-view larger than normal, for high-resolution telescopes, will give a better understanding of processes on the Sun such as filament and active region developments and their possible interactions. New active regions can serve as an igniter of the eruption of a nearby filament. A method to create a large field-of-view is to join several fields-of-view into a mosaic. Fields are imaged quickly, one after another, using fast telescope-pointing. Such a pointing cycle has been automated at the Dutch open telescope (DOT), a high-resolution solar telescope located on the Canary Island La Palma. The number and positions of the subfields are calculated automatically and represented by an array of bright points in the guider image which indicates the subfield centers inside the drawn rectangle of the total field on the computer screen with the whole-sun image. Automatic production of flats is also programmed. For the first time, mosaic movies were programmed from stored information on automated telescope motions. The mosaic movies show larger regions of the solar disk in high resolution and fill a gap between available whole-sun images with limited spatial resolution of synoptic telescopes including space instruments and small-field high-cadence movies of high-resolution solar telescopes.

Hammerschlag, Robert H.; Sliepen, Guus; Bettonvil, Felix C. M.; Jgers, Aswin P. L.; Stterlin, Peter; Lin, Yong; Martin, Sara F.; Panasenco, Olga; Romashets, Eugene P.

2013-08-01

203

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

NASA Astrophysics Data System (ADS)

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).

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

2006-09-01

204

[3H]ouabain autoradiography of frog retina  

PubMed Central

The kinetics and distribution of ouabain binding in retinas of Rana pipiens were examined quantitatively by scintillation counting and freeze-dry autoradiography. The time-course of binding at several concentrations was consistent with a bimolecular reaction. Estimated equilibrium binding levels gave a Michaelis-Menton relationship with a Km = 8.3 x 10(-8) M and a maximum binding level (Bmax) = 4.4 x 10(-8) mol/g protein. The distribution of binding sites measured autoradiographically varied considerably between layers. The photoreceptor, inner plexiform, and optic nerve fiber layers exhibited the heaviest binding. Within the photoreceptor layer, binding was nonuniform. Binding in the outer segment decreased distally, averaging approximately 4% of that in the proximal receptor layers (Bmax = 4.6 x 10(-6) M). The origin of the outer segment activity is uncertain at light microscope resolution, as it may be a result of inner segment calyceal processes. Binding within the proximal receptor layers was also nonuniform. Several peaks were observed, with those at the inner segment and synaptic layers being especially noticeable. Assuming an absence of glial cell binding in the proximal receptor layers, we calculated there to be 13 x 10(6) ouabain or Na+,K+ pump sites per rod receptor. Limited measurements suggest a Bmax of approximately 8 x 10(- 6) M for the inner plexiform layer. PMID:6246120

1980-01-01

205

Progress toward accurate high spatial resolution actinide analysis by EPMA  

Microsoft Academic Search

High precision, high spatial resolution EPMA of actinides is a significant issue for geochronology, resource geochemistry, and studies involving the nuclear fuel cycle. Particular interest focuses on understanding of the behavior of Th and U in the growth and breakdown reactions relevant to actinide-bearing phases (monazite, zircon, thorite, allanite, etc.), and geochemical fractionation processes involving Th and U in fluid

M. J. Jercinovic; J. M. Allaz; M. L. Williams

2010-01-01

206

Inverse scattering for high-resolution interferometric microscopy  

E-print Network

Inverse scattering for high-resolution interferometric microscopy Tyler S. Ralston, Daniel L. Marks of inverse scattering for optical coherence tomography (OCT) to the case of high numerical aperture focusing tech- nique that relies on optical scattering to form micrometer-scale cross-sectional images2 and has

Bhargava, Rohit

207

Case History Imaging permafrost velocity structure using high resolution  

E-print Network

Case History Imaging permafrost velocity structure using high resolution 3D seismic tomography-surface structure in the permafrost terrain. Much of the near subsurface remains frozen but significant melt zones of permafrost ice creating a complex pattern of low and high frequency near-surface velocity variations which

Ramachandran, Kumar

208

RESEARCH ARTICLE Possibilities and limitations for high resolution small  

E-print Network

in experimental neurological and neuroscientific studies to investigate brain injuries or brain plasticity as well-high field animal scanners allow MR imaging with impressively high spatial resolution (on the order of 30 lm. Schmidt Á A. Kretz Á M. Metzler Á C. Gaser Á O. W. Witte Hans Berger Department of Neurology, Jena

Gaser, Christian

209

High spectral resolution measurements for the ARM Program  

SciTech Connect

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}.

Revercomb, H.E.

1992-05-22

210

High-resolution structure of viruses from random diffraction snapshots  

PubMed Central

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

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

2014-01-01

211

High-resolution structure of viruses from random diffraction snapshots  

E-print Network

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 nanocrystalline objects.

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

2014-01-01

212

High-resolution streaming video integrated with UGS systems  

NASA Astrophysics Data System (ADS)

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.

Rohrer, Matthew

2010-04-01

213

High-Resolution Urban Monitoring of Greenhouse Gases and Pollutants  

NASA Astrophysics Data System (ADS)

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

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

2012-12-01

214

Broadband THz high-resolution interferometry using coherent synchrotron radiation  

NASA Astrophysics Data System (ADS)

In storage rings, short electron bunches can produce an intense THz radiation called Coherent Synchrotron Radiation (CSR). The flux of this emission between 250 and 750 GHz is very advantageous for spectroscopy, but intensity fluctuations lead to artifacts in the FTIR spectra and, until now, prevented the use of CSR for high-resolution measurements. At SOLEIL, we found stable CSR conditions for which the signal-to-noise ratio (S/N) allows for measurements at high resolution. Moreover, we developed an artifact correction system, based on a simultaneous detection of the input and the output signals of the interferometer, which allows improving further the signal-to-noise ratio. The stable CSR combined with this ingenious technique allowed us to record for the first time high-resolution FTIR spectra in the sub-THz range, with an exceptional S/N of 100 in a few hours.

Barros, J.; Manceron, L.; Brubach, J.-B.; Evain, C.; Couprie, M.-E.; Tordeux, M.-A.; Labat, M.; Bielawski, S.; Szwaj, C.; Ursu, R.; Roy, P.

2012-10-01

215

High-resolution electromagnetic altimetry over the ocean  

NASA Astrophysics Data System (ADS)

A pair of coils acting as transmitter and receiver of a harmonic electromagnetic (EM) wave is found to be an excellent high-resolution altimeter at low altitudes over ocean regions. Due to high seawater conductivity, the altimetric determination from a received signal is computationally simple. Experimental results obtained from the Cape Cod Bay area indicate that an EM altimeter may be superior in resolution to a radar altimeter. Because of its wide beamwidth, the EM altimeter measures the distance to the instantaneous mean sea level and ignores ripples and waves. This may be considered an advantage over a laser altimeter which, despite its high resolution, is susceptible to noise caused by small surface fluctuations (due to its small beamwidth). The method has potential application to determining the sea-ice thickness.

Won, I. J.

1986-04-01

216

High spatial resolution measurements of ram accelerator gas dynamic phenomena  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

217

The theory and practice of high resolution scanning electron microscopy  

SciTech Connect

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

Joy, D.C. (Tennessee Univ., Knoxville, TN (USA) Oak Ridge National Lab., TN (USA))

1990-01-01

218

New Vacuum Solar Telescope and Observations with High Resolution  

E-print Network

The New Vacuum Solar Telescope (NVST) is a 1 meter vacuum solar telescope that aims to observe the fine structures on the Sun. The main tasks of NVST are high resolution imaging and spectral observations, including the measurements of solar magnetic field. NVST is the primary ground-based facility of Chinese solar community in this solar cycle. It is located by the Fuxian Lake of southwest China, where the seeing is good enough to perform high resolution observations. In this paper, we first introduce the general conditions of Fuxian Solar Observatory and the primary science cases of NVST. Then, the basic structures of this telescope and instruments are described in detail. Finally, some typical high resolution data of solar photosphere and chromosphere are also shown.

Liu, Zhong; Gu, Bo-Zhong; Wang, Sen; You, Jian-Qi; Shen, Long-Xiang; Lu, Ru-Wei; Jin, Zhen-Yu; Chen, Lin-Fei; Lou, Ke; Li, Zhi; Lu, Guang-Qian; Xu, Zhi; Rao, Chang-Hui; Hu, Qi-Qian; Li, Ru-Feng; Fu, Hao-Wen; Bao, Men-Xian; Wu, Ming-Chan; Zhang, Bo-Rong

2014-01-01

219

Quantitative 45Ca autoradiography of human bone  

PubMed Central

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

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

2010-01-01

220

High resolution observations: The state of the art and beyond  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

221

HIRES: the high resolution spectrograph for the E-ELT  

NASA Astrophysics Data System (ADS)

The current instrumentation plan for the E-ELT foresees a High Resolution Spectrograph conventionally indicated as HIRES. Shaped on the study of extra-solar planet atmospheres, Pop-III stars and fundamental physical constants, HIRES is intended to embed observing modes at high-resolution (up to R=150000) and large spectral range (from the blue limit to the K band) useful for a large suite of science cases that can exclusively be tackled by the E-ELT. We present in this paper the solution for HIRES envisaged by the "HIRES initiative", the international collaboration established in 2013 to pursue a HIRES on E-ELT.

Zerbi, F. M.; Bouchy, F.; Fynbo, J.; Maiolino, R.; Piskunov, N.; Rebolo Lopez, R.; Santos, N.; Strassmeier, K.; Udry, S.; Vanzi, L.; Riva, M.; Basden, A.; Boisse, I.; Bonfils, X.; Buscher, D.; Cabral, A.; Dimarcantonio, P.; Di Varano, I.; Henry, D.; Monteiro, M.; Morris, T.; Murray, G.; Oliva, Ernesto; Parry, I.; Pepe, F.; Quirrenbach, A.; Rasilla, J. L.; Rees, P.; Stempels, E.; Valenziano, L.; Wells, M.; Wildi, F.; Origlia, L.; Allende Prieto, C.; Chiavassa, A.; Cristiani, S.; Figueira, P.; Gustafsson, B.; Hatzes, A.; Haehnelt, M.; Heng, K.; Israelian, G.; Kochukhov, O.; Lovis, C.; Marconi, A.; Martins, C. J. A. P.; Noterdaeme, P.; Petitjean, P.; Puzia, T.; Queloz, D.; Reiners, A.; Zoccali, M.

2014-08-01

222

Design of high-resolution grazing-incidence echelle monochromators  

SciTech Connect

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

Poletto, Luca; Frassetto, Fabio

2009-10-01

223

Theoretical Problems in High Resolution Solar Physics, 2  

NASA Technical Reports Server (NTRS)

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.

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

1987-01-01

224

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

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

225

Structural Information, Resolution, and Noise in High-Resolution Atomic Force Microscopy Topographs  

PubMed Central

AFM has developed into a powerful tool in structural biology, providing topographs of proteins under close-to-native conditions and featuring an outstanding signal/noise ratio. However, the imaging mechanism exhibits particularities: fast and slow scan axis represent two independent image acquisition axes. Additionally, unknown tip geometry and tip-sample interaction render the contrast transfer function nondefinable. Hence, the interpretation of AFM topographs remained difficult. How can noise and distortions present in AFM images be quantified? How does the number of molecule topographs merged influence the structural information provided by averages? What is the resolution of topographs? Here, we find that in high-resolution AFM topographs, many molecule images are only slightly disturbed by noise, distortions, and tip-sample interactions. To identify these high-quality particles, we propose a selection criterion based on the internal symmetry of the imaged protein. We introduce a novel feature-based resolution analysis and show that AFM topographs of different proteins contain structural information beginning at different resolution thresholds: 10 (AqpZ), 12 (AQP0), 13 (AQP2), and 20 (light-harvesting-complex-2). Importantly, we highlight that the best single-molecule images are more accurate molecular representations than ensemble averages, because averaging downsizes the z-dimension and blurs structural details. PMID:19413988

Fechner, Peter; Boudier, Thomas; Mangenot, Stephanie; Jaroslawski, Szymon; Sturgis, James N.; Scheuring, Simon

2009-01-01

226

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

PubMed

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. PMID:25144465

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

2014-09-21

227

Evaluation of High-Resolution Precipitation Estimates from Satellite Observations  

NASA Astrophysics Data System (ADS)

During recent years, a number of satellite-derived, globally complete, high resolution precipitation products with a spatial resolution of at least 0.25 and a temporal resolution of at least three-hourly have been developed and produced regularly. These products generally merge geostationary infra-red data and polar- orbiting passive microwave data to take advantage of the high sampling of the infra-red and the superior quality of the microwave, and sometimes use ancillary data such as radar or gauge observations or model output. The Program to Evaluate High Resolution Precipitation Products (PEHRPP) was established by the International Precipitation Working Group to evaluate and inter-compare these datasets at a variety of spatial and temporal resolutions with the intent of guiding dataset developers and informing the user community regarding the error characteristics of these useful products. This presentation will summarize the current state of PEHRPP-related investigations, including the results from the International PEHRPP Workshop held in December 2007.

Arkin, P.; Turk, J.; Sapiano, M.; Ebert, B.

2008-05-01

228

Progress in high-resolution x-ray holographic microscopy  

SciTech Connect

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.

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

1987-07-01

229

High-resolution structure of the native histone octamer  

PubMed Central

Crystals of native histone octamers (H2AH2B)(H4H3)(H3?H4?)(H2B?H2A?) from chick erythrocytes in 2?M KCl, 1.35?M potassium phosphate pH 6.9 diffract X-rays to 1.90? resolution, yielding a structure with an R work value of 18.7% and an R free of 22.2%. The crystal space group is P65, the asymmetric unit of which contains one complete octamer. This high-resolution model of the histone-core octamer allows further insight into intermolecular interactions, including water molecules, that dock the histone dimers to the tetramer in the nucleosome-core particle and have relevance to nucleosome remodelling. The three key areas analysed are the H2A?H3H4 molecular cluster (also H2AH3?H4?), the H4H2B? interaction (also H4?H2B) and the H2A?H4 ?-sheet interaction (also H2AH4?). The latter of these three regions is important to nucleosome remodelling by RNA polymerase II, as it is shown to be a likely core-histone binding site, and its disruption creates an instability in the nucleosome-core particle. A majority of the water molecules in the high-resolution octamer have positions that correlate to similar positions in the high-resolution nucleosome-core particle structure, suggesting that the high-resolution octamer model can be used for comparative studies with the high-resolution nucleosome-core particle. PMID:16511091

Wood, Christopher M.; Nicholson, James M.; Lambert, Stanley J.; Chantalat, Laurent; Reynolds, Colin D.; Baldwin, John P.

2005-01-01

230

High-resolution 3D coherent laser radar imaging  

Microsoft Academic Search

High range-resolution active imaging requires high-bandwidth transmitters and receivers. At Lockheed Martin Coherent Technologies (LMCT), we are developing both linear Frequency Modulated Continuous Wave (FMCW) and short pulse laser radar sensors to supply the needed bandwidth. FMCW waveforms are advantageous in many applications, since target returns can be optically demodulated, mitigating the need for high-speed detectors and receiver electronics, enabling

Brian Krause; Philip Gatt; Carl Embry; Joseph Buck

2006-01-01

231

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

NASA Astrophysics Data System (ADS)

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.

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

2013-12-01

232

High resolution near IR spectroscopy with GIANO-TNG  

NASA Astrophysics Data System (ADS)

GIANO is the high resolution near IR spectrograph recently commissioned at the 3.58m Telescopio Nazionale Galileo in La Palma (Spain). GIANO is the first worldwide instrument providing cross-dispersed echelle spectroscopy at a resolution of 50,000 over the 0.95 - 2.45 micron spectral range in a single exposure. There are outstanding science cases in the research fields of exo-planets, Galactic stars and stellar populations that could strongly benefit from GIANO observations down to a magnitude limit comparable to that of 2MASS. The instrument includes a fully cryogenic spectrograph and an innovative fiber system transmitting out to the K band. It also represents a formidable laboratory to test performances and prototype solutions for the next generation of high resolution near IR spectrographs at the ELTs. First results from sky tests at the telescope and science verification occurred between July 2012 and October 2013 will be presented.

Origlia, L.; Oliva, E.; Baffa, C.; Falcini, G.; Giani, E.; Massi, F.; Montegriffo, P.; Sanna, N.; Scuderi, S.; Sozzi, M.; Tozzi, A.; Carleo, I.; Gratton, R.; Ghinassi, F.; Lodi, M.

2014-07-01

233

Note: Differential amplified high-resolution tilt angle measurement system  

NASA Astrophysics Data System (ADS)

A high-resolution tilt angle measurement system is presented in this paper. In this system, the measurement signal is amplified by two steps: (1) amplified by operational amplifier and (2) differential amplified by two MEMS-based inclinometers. The novel application not only amplifies the signal but, more importantly, substantially reduces the electrical interference and common-mode noise among the same circuit design. Thus, both the extremely high resolution and great long-term stability are achieved in this system. Calibrated by an autocollimator, the system shows a resolution of 2 arc sec. The accuracy is better than 1.5 arc sec. The zero-drift error is below 1 arc sec and 2 arc sec in the short and long term, respectively.

Zhao, Shijie; Li, Yan; Zhang, Enyao; Huang, Pei; Wei, Haoyun

2014-09-01

234

FTMS method for high resolution matrix-assisted laser desorption  

NASA Astrophysics Data System (ADS)

A Fourier transform mass spectrometer with an external ion source has been modified for use with matrix-assisted laser desorption. High trapping potentials on the FTMS analyzer cell decelerate and trap the laser-produced ions, and a pulsed argon buffer gas coosl them prior to detection. For gramicidin S, only one laser pulse is needed to produce ass spectra with a high signal-to-noise ratio and a mass resolution of 1 100 000 (FWHM). Several other oligopeptides and small proteins have been analyzed, including bovine insulin that was detected at a mass resolution of 90 000. These results represent the highest mass resolution ever demonstrated for ions made by MALDI.

McIver, Robert T., Jr.; Li, Yunzhi; Hunter, Richard L.

1994-04-01

235

Note: Differential amplified high-resolution tilt angle measurement system.  

PubMed

A high-resolution tilt angle measurement system is presented in this paper. In this system, the measurement signal is amplified by two steps: (1) amplified by operational amplifier and (2) differential amplified by two MEMS-based inclinometers. The novel application not only amplifies the signal but, more importantly, substantially reduces the electrical interference and common-mode noise among the same circuit design. Thus, both the extremely high resolution and great long-term stability are achieved in this system. Calibrated by an autocollimator, the system shows a resolution of 2 arc sec. The accuracy is better than 1.5 arc sec. The zero-drift error is below 1 arc sec and 2 arc sec in the short and long term, respectively. PMID:25273790

Zhao, Shijie; Li, Yan; Zhang, Enyao; Huang, Pei; Wei, Haoyun

2014-09-01

236

Unsupervised Feature Learning for High-Resolution Satellite Image Classification  

SciTech Connect

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.

Cheriyadat, Anil M [ORNL

2013-01-01

237

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

SciTech Connect

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

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

2007-01-01

238

High spatial resolution spin-polarized scanning electron microscopy (abstract)  

NASA Astrophysics Data System (ADS)

Spin-polarized scanning electron microscopy (spin SEM) to observe magnetic domains has the potential for spatial resolution as high as 10 nm. The best resolution from spin SEMs attained so far, however, is around 50 nm. In this talk, we report a newly developed spin SEM with 20 nm resolution. The major factor determining the resolution of a spin SEM is probe diameter. A smaller probe diameter, however, results in lower probe current. This is a serious issue in spin SEM because the efficiency of a spin detector is very low. Thus, to get high resolution with a reasonable signal/noise (S/N) image, higher efficiency in the spin detector and/or higher probe current are needed in addition to get a smaller probe diameter. The higher probe current has been attained by using a thermal assisted field emission cathode in an electron gun. The higher efficiency in the spin detector was achieved by increasing the acceptance angle of electron detectors inside the spin detector and optimizing both a secondary collector and transport optics. Obtaining a smaller probe diameter required a low aberration objective lens and a short working distance. Those were achieved by computer calculation so that there was no interference between the objective lens and the secondary collector. This achieved both a short working distance of 20 mm and high secondary collection efficiency. As a result, magnetic images of 20 nm resolution with a 25 keV and 1 nA probe beam have been attained. We have applied this spin SEM to observing recorded bits of longitudinal thin film media at high recording densities.

Matsuyama, H.; Koike, K.; Tomiyama, F.; Aoi, H.; Shiroishi, Y.; Ishikawa, A.

1994-05-01

239

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

ERIC Educational Resources Information Center

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

Wakabayashi, Fumitaka; Hamada, Kiyohito

2006-01-01

240

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...

241

Dynamic tracking delays using high resolution electro-tactile feedback  

Microsoft Academic Search

The development of a high resolution electrotactile feedback display with spatial coding, designed to explore the limits of electrotactile feedback for use in prosthetic control systems, is discussed. Specifically, the delays between input and output for the dynamic tracking of randomly appearing targets is measured for the natural arm and for a rate-command-driven (computer modeled) prosthetic arm with visual or

C. N. Tupper; G. C. Gerhard

1989-01-01

242

Ultra-High Resolution Imaging by Fluorescence Photoactivation Localization Microscopy  

E-print Network

than rR. New imaging methods such as 4Pi microscopy (4­9), patterned illumination microscopy (10Ultra-High Resolution Imaging by Fluorescence Photoactivation Localization Microscopy Samuel T of Maine, Orono, Maine ABSTRACT Biological structures span many orders of magnitude in size, but far

La Rosa, Andres H.

243

High-Resolution Stimulated Raman Gain Spectroscopy of Parahydrogen Crystals  

E-print Network

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

Oka, Takeshi

244

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...

245

Exchange Bias Systems studied by High Resolution Quantitative Magnetic Force  

E-print Network

Exchange Bias Systems studied by High Resolution Quantitative Magnetic Force Microscopy;Abstract It is generally believed that exchange bias (EB) implies the presence of pinned uncompen- sated domains to areas of proportionally higher pin-UCS aligned antiparallel to F-moments. This confirms our

Amrhein, Valentin

246

First high-resolution measurements by the Freja satellite  

Microsoft Academic Search

The joint Swedish-German Freja satellite was successfully launched on October 6, 1992. Freja contains an extensive set of plasma and field instruments for high time-resolution measurements of the auroral plasma in the altitude range 600 - 1750 km. The satellite also contains two UV imagers to monitor the auroral activity at the geomagnetic footprint of the satellite. In this paper

R. Lundin; L. Eliasson; O. Norberg; G. Marklund; L. R. Zanetti; L. A. Whalen; B. Holback; J. S. Murphree; G. Haerendel; M. Boehm; G. Paschmann

1994-01-01

247

Unmanned Aircraft Systems (UAS) for Vegetation Mapping: Very High Resolution  

E-print Network

Unmanned Aircraft Systems (UAS) for Vegetation Mapping: Very High Resolution Multispectral Imagery S. Laliberte and Albert Rango ASPRS 2011 Annual Conference, Apr. 26-30, San Diego, CA #12;UAS for vegetation mapping · Increased interest in and applications for UAS for remote sensing · Greater access

248

Workshop on high-resolution, large-acceptance spectrometers  

SciTech Connect

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.

Zeidman, B. (ed.)

1981-01-01

249

High resolution 3D snapshot ISAR imaging and feature extraction  

Microsoft Academic Search

We have developed a new formulation for three dimensional (3D) radar imaging of inverse synthetic aperture radar (ISAR) data based on recent developments in high resolution spectral estimation theory. Typically for non real-time applications, image formation is a two step process consisting of motion determination and image generation. The technique presented focuses on this latter process, and assumes the motion

J. T. Mayhan; M. L. Burrows; K. M. Cuomo; J. E. Piou

2001-01-01

250

Airborne High Spectral Resolution Lidar Aerosol Measurements during ARCTAS  

Microsoft Academic Search

The NASA Langley Research Center (LaRC) airborne High Spectral Resolution Lidar (HSRL) on the NASA B200 aircraft measured aerosol extinction (532 nm), backscatter (532 and 1064 nm), and depolarization (532 and 1064 nm) profiles during the 2008 Arctic Research of the Composition of the Troposphere from Aircraft and Satellites (ARCTAS) field campaign. HSRL data were acquired during 15 science flights

R. A. Ferrare; C. A. Hostetler; J. W. Hair; A. Cook; D. Harper; S. P. Burton; M. D. Obland; R. Rogers; A. J. Swanson; A. D. Clarke; C. S. McNaughton; Y. Shinozuka; J. Redemann; J. M. Livingston; P. B. Russell; C. A. Brock; D. A. Lack; K. D. Froyd; J. A. Ogren; B. Andrews; A. Laskin; R. Moffet; M. K. Gilles; A. Nenes; T. L. Lathem; P. Liu

2009-01-01

251

AIRBORNE HIGH SPECTRAL RESOLUTION LIDAR MEASUREMENTS OF ATMOSPHERIC AEROSOLS  

E-print Network

Research Center (LaRC) recently developed an airborne High Spectral Resolution Lidar (HSRL) to measure aerosol distributions and optical properties. The HSRL technique takes advantage of the spectral aerosol extinction and backscatter independently. The LaRC instrument employs the HSRL technique

252

Atmospheric temperature measurement by a high spectral resolution lidar  

Microsoft Academic Search

A method is proposed for selecting an atomic vapor filter and its optimum temperature for measuring atmospheric temperature with a high-spectral-resolution lidar (HSRL). An error analysis and an evaluation of the sensitivity of HSRL are carried out, and it is shown that the accuracy of HSRL and its sensitivity are adequate for practical use. The SM and S6 models used

Hiroshi Shimizu; Kazuo Noguchi; C.-Y. She

1986-01-01

253

Airborne High Spectral Resolution Lidar Measurements of Atmospheric Aerosols  

Microsoft Academic Search

NASA Langley Research Center (LaRC) recently developed an airborne High Spectral Resolution Lidar (HSRL) to measure aerosol distributions and optical properties. The HSRL technique takes advantage of the spectral distribution of the lidar return signal to discriminate aerosol and molecular signals and thereby measure aerosol extinction and backscatter independently. The LaRC instrument employs the HSRL technique to measure aerosol backscatter

R. Ferrare; C. Hostetler; J. Hair; A. Cook; D. Harper; L. Kleinman; A. Clarke; P. Russell; J. Redemann; J. Livingston; J. Szykman; J. Al-Saadi

2007-01-01

254

Depolarization Measurements with the High Spectral Resolution Lidar  

NASA Technical Reports Server (NTRS)

This paper describes modifications to the University of Wisconsin High Spectral Resolution Lidar (HSRL) which permit very precise depolarization measurements in addition to optical depth, backscatter cross section, and extinction cross section measurements. Because HSRL separates the lidar return into aerosol and molecular contributions, they can be measured separately.

Eloranta, E. W.; Piironen, P.

1996-01-01

255

Measurement of extinction cross section by high spectral resolution lidar  

Microsoft Academic Search

A high-spectral-resolution lidar (HSRL) designed to overcome the problems involved in assessing visibility and measuring aerosol optical properties by interferometrically separating the backscatter return into a component due to aerosol scattering and a component due to scattering from air molecules is presented. A graph is provided to show the extinction cross section measured by the HSRL averaged over a 2-km

Christian J. Grund; Edwin W. Eloranta

1991-01-01

256

Communications: Nanomagnetic shielding: High-resolution NMR in carbon allotropes  

E-print Network

Communications: Nanomagnetic shielding: High-resolution NMR in carbon allotropes Y. Kim,1,a E. Abou report the largest diamagnetic shifts down to 68.3 ppm ever observed in carbon allotropes, which of the magnetic properties of carbon-based materials is of fundamental relevance in applications in nano

Zettl, Alex

257

Very high-resolution mapping of river-immersed topography  

E-print Network

techniques used for river bathymetry are reviewed. Frequently, these techniques have been developedVery high-resolution mapping of river-immersed topography by remote sensing Denis Feurer,1,2 * Jean cases: inaccessible rivers, large-scale depth mapping, very shallow rivers. The remote sensing

Paris-Sud XI, Université de

258

Super-Resolution Image with Estimated High Frequency Compensated Algorithm  

E-print Network

concept is to use signal processing techniques to obtain a high resolution (HR) image from observed single including video surveillance, medical imaging, satellite imaging, and video delivery and playback. SR image interpolation methods to enlarge the image, and then process it according to Iterative Back

Chang, Pao-Chi

259

High-Resolution Simulations of Parallel BladeVortex Interactions  

E-print Network

contribution coming from the trailing edge. The simulations are then extended to three-dimensional moving overset meshes where the vortex generation and convection is also resolved. The numerical methodology. A high-resolution solution of the compressible Euler equations is performed on structured overset meshes

Alonso, Juan J.

260

Adaptive optics with pupil tracking for high resolution retinal imaging  

E-print Network

Adaptive optics with pupil tracking for high resolution retinal imaging Betul Sahin,1, Barbara@gmail.com Abstract: Adaptive optics, when integrated into retinal imaging systems, compensates for rapidly changing with a compact adaptive optics flood illumination fundus camera where it was possible to compensate

Dainty, Chris

261

Urban road extraction from high-resolution optical satellite images  

Microsoft Academic Search

In recent years, many approaches have been exploited for automatic urban road extraction. Most of these approaches are based on edge and line detecting algorithms. In this paper, a new integrated system for automatic extraction of main roads in high-resolution optical satellite images is present. Firstly, a multi-scale greylevel morphological cleaning algorithm is proposed to reduce the grey deviation of

Hui Long; Zhongming Zhao

2005-01-01

262

Ship Detection and Recognitionin High-resolution Satellite Images  

Microsoft Academic Search

Nowadays, the availability of high-resolution images taken from satellites, like Quickbird, Orbview, and others, offers the remote sensing community the possibility of monitoring and surveying vast areas of the Earth for different purposes, e.g. monitoring forest regions for ecological reasons. A particular application is the use of satellite images to survey the bottom of the seas around the Iberian peninsula

Jose Antelo; Gregorio Ambrosio; Javier Gonzalez; Cipriano Galindo

2009-01-01

263

Radiative transfer model for simulating high-resolution satellite images  

Microsoft Academic Search

A simulator of high spatial resolution satellite images is introduced. It is based on the coupling of two radiative transfer models: discrete anisotropic radiative transfer (DART) for terrestrial landscapes and second simulation of the satellite signal in the solar spectrum (6S) for the atmosphere. It works in the visible, near infrared, and midinfrared domains. The simulation procedure involves four steps:

Ferran Gascon; Jean-Philippe Gastellu-Etchegorry; Marie-Jos Lefvre

2001-01-01

264

Overview of the High Resolution Fly's Eye Cosmic Ray Observatory  

Microsoft Academic Search

The High Resolution (HiRes) Fly's Eye cosmic ray observatory is used to detect and study the highest energy particles. The HiRes detector utilizes the atmosphere as a calorimeter to perform measurements of the energies of the primary cosmic rays as well as determine the energy spectrum and composition of cosmic rays and search for anisotropy in arrival direction. A description

Gregory C. Archbold; R. Abassi; T. Abu-Zayyad; K. Belov; Z. Cao; S. Christopherson; A. Everett; R. Gray; B. F. Jones; C. C. H. Jui; D. B. Kieda; K. Kim; E. C. Loh; K. Martens; J. N. Matthews; J. Meyer; S. A. Moore; A. Moosman; P. Morrison; R. Mumford; K. Reil; R. Riehle; J. D. Smith; P. Sokolsky; R. W. Springer; B. Stokes; S. B. Thomas; L. Wienke; T. Vanderveen; A. Yates; J. Bellido; B. R. Dawson; R. W. Clay; K. Simpson; J. Boyer; Y. Ho; B. Knapp; W. Lee; E. J. Mannel; M. Seman; C. Song; S. Westerhoff; X. Zhang; J. Belz; B. D. Dieterle; G. Martin; J. A. J. Matthews; S. Riley; D. Bergman; W. Hanlon; G. Thompson; N. Manago; M. Sasaki; M. Sasano; M. Teshima; M. Chikawa

2000-01-01

265

High resolution bone mineral densitometry with a gamma camera  

NASA Technical Reports Server (NTRS)

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.

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

1983-01-01

266

MAPPING HIGH-RESOLUTION LAND SURFACE RADIATIVE FLUXES FROM MODIS  

E-print Network

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

Liang, Shunlin

267

High-resolution lithography based on selective removal of atoms  

SciTech Connect

A new method of high-resolution lithography based on selective removal of atoms is described. Drawbacks of lift-off lithography in comparison with the method proposed are pointed out and test structures of metal (Mo) stripes with a thickness of 50 nm are obtained.

Domantovskii, A. G.; Gurovich, B. A.; Maslakov, K. I. [Russian Research Centre Kurchatov Institute (Russian Federation)

2006-12-15

268

High Resolution Imaging of Circumstellar Disks at Millimeter Wavelengths  

NASA Technical Reports Server (NTRS)

We update progress on our research program to use high angular resolution imaging of thermal dust continuum emission at millimeter and submillimeter wavelengths to probe the structure of protoplanetary disks and debris disks around nearby stars. Observations at these wavelengths are advantageous because the dust emission is generally optically thin and directly proportional to mass, contrast with stellar photospheres is not problematic, and the wavelength dependence provides information on an important regime of grain sizes. We employ several facilities for state-of-the-art high resolution observations, including the Very Large Array (VLA), the Australia Telescope Compact Array (ATCA), the Plateau de Bure Interferometer (PdBI) of the Institut de RadioAstronomie Millimetrique, the Submillimeter Array (SMA) of the Smithsonian Astrophysical Observatory, and the Caltech Submillimeter Observatory (CSO). Many recent highlights of our program were presented in an invited review on High Angular Resolution Studies of Disks- the Millimetre at IAU Symposium 221, Star Formation at High Angular Resolution, in July 2003.

Wilner, David J.

2003-01-01

269

Plant respirometer enables high resolution of oxygen consumption rates  

NASA Technical Reports Server (NTRS)

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.

Foster, D. L.

1966-01-01

270

High resolution DNA fingerprinting of Acinetobacter outbreak strains  

Microsoft Academic Search

AFLPTM is a novel high resolution fingerprinting method that can be used to delineate intraspecific relationships among a large variety of organisms, including bacteria. In the present study, this method was tested for its usefulness in the epidemiological typing of Acinetobacter strains. A total of 25 Acinetobacter strains originating from five hospital outbreaks in three countries were used. Isolates from

Paul Janssen; Lenie Dijkshoorn

1996-01-01

271

A sledge microtome for high resolution subsampling of freeze cores  

E-print Network

interface, which is A. L. Macumber (&) Á R. T. Patterson Á L. A. Neville Department of Earth SciencesNOTES A sledge microtome for high resolution subsampling of freeze cores Andrew L. Macumber · R. Timothy Patterson · Lisa A. Neville · Hendrik Falck Received: 6 August 2010 / Accepted: 2 December 2010

Patterson, Timothy

272

Measuring Suspended Sediments Using High Resolution Acoustic Velocimeters  

E-print Network

acoustic sensorBistatic acoustic sensor Doppler shift gives rise to velocity profile M k f th M d O di to a broad range of particle sizes #12;The Sensors Nortek Vector 6 MHz Sampling volume located 15.7 cm fromMeasuring Suspended Sediments Using High Resolution Acoustic Velocimeters Clementina R. Russo

Boss, Emmanuel S.

273

Towards very high resolution RPC-PET for small animals  

NASA Astrophysics Data System (ADS)

We present imaging results of needle-like and planar 22Na sources obtained with a prototype of a high-acceptance small-animal positron emission tomograph based on resistive plate chambers (RPC-PET). The maximum-likelihood expectation-maximization (MLEM) reconstruction of the acquired data yielded an excellent and stable resolution of 0.4 mm FWHM.

Martins, P.; Blanco, A.; Crespo, P.; Ftima Ferreira Marques, M.; Ferreira Marques, R.; Gordo, P. M.; Kajetanowicz, M.; Korcyl, G.; Lopes, L.; Michel, J.; Palka, M.; Traxler, M.; Fonte, P.

2014-10-01

274

High-resolution, multi-scale modeling of watershed hydrology  

E-print Network

High-resolution, multi-scale modeling of watershed hydrology CUAHSI Cyber Seminar October 3, 2003 and Distributed Modeling in a Hydrologic Observatory Assistant Professor of Hydrology Department of Earth and Environmental Science New Mexico Institute of Mining and Technology #12;2 Real and Virtual Hydrologic

Vivoni, Enrique R.

275

ORIGINAL ARTICLE High resolution linkage and linkage disequilibrium analyses  

E-print Network

ORIGINAL ARTICLE High resolution linkage and linkage disequilibrium analyses of chromosome 1p36 this region for linkage and association to BMD in 39 osteoporosis pedigrees. Our results support the presence as a QTL for BMD from linkage (maximum lod- score=2.87) and linkage disequilibrium (LD) analysis (p

Pennsylvania, University of

276

High Range Resolution (HRR) profiling within low elevation search mode  

Microsoft Academic Search

In this paper, we describe the high range resolution (HRR) profiling technique for generating the target range profile while the radar is in the low elevation search mode. The major advantage of this concept is reuse of the moving target detection (MTD) radar data for formulating the target range profile to provide the early target classification, discrimination, and identification (CDI)

Fabio Bonanni; Claudio Ponzi; Quoc Henry Pham

2008-01-01

277

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

SciTech Connect

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.

SCHOFIELD JS

2007-10-04

278

3D high resolution pure optical photoacoustic microscopy  

NASA Astrophysics Data System (ADS)

The concept of pure optical photoacoustic microscopy(POPAM) was proposed based on optical rastering of a focused excitation beam and optically sensing the photoacoustic signal using a microring resonator fabricated by a nanoimprinting technique. After some refinedment of in the resonator structure and mold fabrication, an ultrahigh Q factor of 3.0105 was achieved which provided high sensitivity with a noise equivalent detectable pressure(NEDP) value of 29Pa. This NEDP is much lower than the hundreds of Pascals achieved with existing optical resonant structures such as etalons, fiber gratings and dielectric multilayer interference filters available for acoustic measurement. The featured high sensitivity allowed the microring resonator to detect the weak photoacoustic signals from micro- or submicroscale objects. The inherent superbroad bandwidth of the optical microring resonator combined with an optically focused scanning beam provided POPAM of high resolution in the axial as well as both lateral directions while the axial resolution of conventional photoacoustic microscopy (PAM) suffers from the limited bandwidth of PZT detectors. Furthermore, the broadband microring resonator showed similar sensitivity to that of our most sensitive PZT detector. The current POPAM system provides a lateral resolution of 5?m and an axial resolution of 8?m, comparable to that achieved by optical microscopy while presenting the unique contrast of optical absorption and functional information complementing other optical modalities. The 3D structure of microvasculature, including capillary networks, and even individual red blood cells have been discerned successfully in the proof-of-concept experiments on mouse bladders ex vivo and mouse ears in vivo. The potential of approximately GHz bandwidth of the microring resonator also might allow much higher resolution than shown here in microscopy of optical absorption and acoustic propagation properties at depths in unfrozen tissue specimens or thicker tissue sections not now imageable with current optical or acoustic microscopes of comparable resolution.

Xie, Zhixing; Chen, Sung-Liang; Ling, Tao; Guo, L. Jay; Carson, Paul L.; Wang, Xueding

2012-02-01

279

High-resolution threshold photoelectron spectroscopy by electron attachment  

NASA Technical Reports Server (NTRS)

A new technique for measuring high-resolution threshold photoelectron spectra of atoms, molecules, and radicals is described. It involves photoionization of a gaseous species, attachment of the threshold, or nearly zero electron to some trapping molecule (here SF6 or CFCl3), and mass detection of the attachment product (SF6/-/ or Cl/-/ respectively). This technique of threshold photoelectron spectroscopy by electron attachment was used to measure the spectra of argon and xenon at 11 meV (FWHM) resolution, and was also applied to CFCl3.

Ajello, J. M.; Chutjian, A.

1976-01-01

280

Precipitation Sensing in GEO Orbit with High Resolution  

NASA Astrophysics Data System (ADS)

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.

You, Rui

2012-07-01

281

High resolution polar Kerr magnetometer for nanomagnetism and nanospintronics.  

PubMed

A new high resolution polar magneto-optical (MO) Kerr magnetometer, devoted to the study of nanometer sized elements with perpendicular magnetic anisotropy, is described. The unique performances of this setup in terms of sensitivity (1.2x10(-15) emu), stability (lateral drift +/-35 nm over 3 h), and resolution (laser spot full width at half maximum down to 470 nm) are demonstrated, and illustrated by Kerr hysteresis loop measurements on a unique ultrathin magnetic nanodot, and over small segments of ultranarrow magnetic tracks. Large scanning MO Kerr microscopy images were also obtained with the same performances. PMID:18377014

Cormier, M; Ferr, J; Mougin, A; Cromires, J-P; Klein, V

2008-03-01

282

High resolution polar Kerr magnetometer for nanomagnetism and nanospintronics  

NASA Astrophysics Data System (ADS)

A new high resolution polar magneto-optical (MO) Kerr magnetometer, devoted to the study of nanometer sized elements with perpendicular magnetic anisotropy, is described. The unique performances of this setup in terms of sensitivity (1.210-15emu), stability (lateral drift 35nm over 3h), and resolution (laser spot full width at half maximum down to 470nm) are demonstrated, and illustrated by Kerr hysteresis loop measurements on a unique ultrathin magnetic nanodot, and over small segments of ultranarrow magnetic tracks. Large scanning MO Kerr microscopy images were also obtained with the same performances.

Cormier, M.; Ferr, J.; Mougin, A.; Cromires, J.-P.; Klein, V.

2008-03-01

283

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

E-print Network

High-resolution, high-throughput SNP mapping in Drosophila melanogaster Doris Chen1,5, Annika and high-throughput genotyping assays for Drosophila melanogaster. Our map comprises 27,367 SNPs in common­4, Drosophila melanogaster5­8, Danio rerio9 and Arabidopsis thaliana10,11. The resolution of SNP mapping is

Cai, Long

284

Design of the CHIRON high-resolution spectrometer at CTIO  

NASA Astrophysics Data System (ADS)

Small telescopes coupled to high resolution spectrometers are powerful tools for Doppler planet searches. They allow for high cadence observations and flexible scheduling; yet there are few such facilities. We present an innovative and inexpensive design for CHIRON, a high resolution (R~80.000) Echelle spectrometer for the 1.5m telescope at CTIO. Performance and throughput are very good, over the whole spectral range from 410 to 870nm, with a peak efficiency of 15% in the iodine absorption region. The spectrograph will be fibre-fed, and use an iodine cell for wavelength calibration. An image slicer permits a moderate beam size. We use commercially available, high performance optical components, which is key for quick and efficient implementation. We discuss the optical design, opto-mechanical tolerances and resulting image quality.

Schwab, Christian; Spronck, Julien F. P.; Tokovinin, Andrei; Fischer, Debra A.

2010-07-01

285

Scalable, flexible and high resolution patterning of CVD graphene.  

PubMed

The unique properties of graphene make it a promising material for interconnects in flexible and transparent electronics. To increase the commercial impact of graphene in those applications, a scalable and economical method for producing graphene patterns is required. The direct synthesis of graphene from an area-selectively passivated catalyst substrate can generate patterned graphene of high quality. We here present a solution-based method for producing patterned passivation layers. Various deposition methods such as ink-jet deposition and microcontact printing were explored, that can satisfy application demands for low cost, high resolution and scalable production of patterned graphene. The demonstrated high quality and nanometer precision of grown graphene establishes the potential of this synthesis approach for future commercial applications of graphene. Finally, the ability to transfer high resolution graphene patterns onto complex three-dimensional surfaces affords the vision of graphene-based interconnects in novel electronics. PMID:24189709

Hofmann, Mario; Hsieh, Ya-Ping; Hsu, Allen L; Kong, Jing

2014-01-01

286

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

287

Scalable, flexible and high resolution patterning of CVD graphene  

NASA Astrophysics Data System (ADS)

The unique properties of graphene make it a promising material for interconnects in flexible and transparent electronics. To increase the commercial impact of graphene in those applications, a scalable and economical method for producing graphene patterns is required. The direct synthesis of graphene from an area-selectively passivated catalyst substrate can generate patterned graphene of high quality. We here present a solution-based method for producing patterned passivation layers. Various deposition methods such as ink-jet deposition and microcontact printing were explored, that can satisfy application demands for low cost, high resolution and scalable production of patterned graphene. The demonstrated high quality and nanometer precision of grown graphene establishes the potential of this synthesis approach for future commercial applications of graphene. Finally, the ability to transfer high resolution graphene patterns onto complex three-dimensional surfaces affords the vision of graphene-based interconnects in novel electronics.The unique properties of graphene make it a promising material for interconnects in flexible and transparent electronics. To increase the commercial impact of graphene in those applications, a scalable and economical method for producing graphene patterns is required. The direct synthesis of graphene from an area-selectively passivated catalyst substrate can generate patterned graphene of high quality. We here present a solution-based method for producing patterned passivation layers. Various deposition methods such as ink-jet deposition and microcontact printing were explored, that can satisfy application demands for low cost, high resolution and scalable production of patterned graphene. The demonstrated high quality and nanometer precision of grown graphene establishes the potential of this synthesis approach for future commercial applications of graphene. Finally, the ability to transfer high resolution graphene patterns onto complex three-dimensional surfaces affords the vision of graphene-based interconnects in novel electronics. Electronic supplementary information (ESI) available: Detailed materials characterization and experimental procedures. See DOI: 10.1039/c3nr04968j

Hofmann, Mario; Hsieh, Ya-Ping; Hsu, Allen L.; Kong, Jing

2013-12-01

288

High-resolution schemes for hyperbolic conservation laws  

NASA Technical Reports Server (NTRS)

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.

Harten, A.

1982-01-01

289

Precision rectification of high resolution satellite imagery without ephemeris data  

NASA Astrophysics Data System (ADS)

The huge capability of high resolution satellite imageries (HRSI), that includes spatial, spectral, temporal and radiometric resolutions as well as stereoscopic vision introduces them as a powerful new source for the Photogrammetry, Remote Sensing and GIS communities. High resolution data increases the need for higher accuracy of data modeling. The satellite orbit, position, attitude angles and interior orientation parameters have to be adjusted in the geometrical model to achieve optimal accuracy with the use of a minimum number of Ground Control Points (GCPs). But most high resolution satellite vendors do not intend to publish their sensor models and ephemeris data. There is consequently a need for a range of alternative, practical approaches for extracting accurate 2D and 3D terrain information from HRSI. The flexibility and good accuracy of the alternative models demonstrated with KFA-1000 and the well-known SPOT level 1A images. A block of eight KFA-1000 space photos in two strips with 60% longitudinal overlap and 15% lateral sidelap and SPOT image with rational function, DLT, 2D projective, polynomials, affine, conformal, multiquadric and finite element methods were used in the test. The test areas cover parts of South and West of Iran. Considering the quality of GCPs, the best result was found with the DLT method with a RMSE of 8.44 m for the KFA-1000 space photos.

Sadeghian, Saeid; Valadan Zoej, Mohammad Javad; Delavar, Mahmoud Reza; Abootalebi, Ahmad

290

High resolution imaging with impulse based thermoacoustic tomography  

NASA Astrophysics Data System (ADS)

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 ?m, reveal the resolution performance which yields 160 ?m. 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.

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

2011-07-01

291

High-resolution Imaging Techniques for the Assessment of Osteoporosis  

PubMed Central

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

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

2010-01-01

292

Broadband high resolution X-ray spectral analyzer  

DOEpatents

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.

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

293

Construction of a high resolution electron beam profile monitor  

SciTech Connect

Bremsstrahlung from an electron beam on a heavy target can be used to image the beam profile using collimators and slits. The limiting resolution using this system is determined by Fresnel diffraction, and is {approximately} {radical}({lambda}d/2), where {lambda} is the photon wavelength and d is determined by the linear dimensions of the system. For linear colliders this resolution could be a few nm. The highest resolution requires detectors which see only high energy, (small {lambda}), photons, and this is accomplished by converting photons to pairs, and detecting Cherenkov light in a nearly forward angle with a CCD detector or streak camera. Tests are planned at the Argonne APS and SLAC FFTB.

Norem, J.; Dawson, J.; Haberichter, W.; Novak, W.; Reed, L.; Yang, X.F.

1993-08-01

294

High resolution characterization of plasmon resonances in silver nanostructures  

NASA Astrophysics Data System (ADS)

In this work, we use the iterative Richardson-Lucy (RL) deconvolution to further increase the energy resolution of electron energy loss spectra of surface plasmon resonances (SPR) in silver nanostructures. We obtain a record e_ective energy resolution of 10 meV after 500 iterations for spectral features below 1 eV. We extract energy- _ltered maps of SPR of a nanorod at energies down to 0.25 eV, corresponding to the mid-infrared region on the electromagnetic spectrum. And we are able to identify hydrid-SPR peaks separated by only 70 meV from two nano-squares with a gap of 100 nm between them, demonstrating that the RL deconvolution applied to spectra acquired with a monochromator is a useful tool to characterize plasmonic structures at low energies with high energy resolution.

Bellido, Edson P.; Rossouw, David; Botton, Gianluigi A.

2014-09-01

295

Deep-towed High Resolution multichannel seismic imaging  

NASA Astrophysics Data System (ADS)

High Resolution (220-1050 Hz) seismic acquisition performed in deep water using deep-towed systems provides unrivalled lateral resolution when compared to conventional surface seismic. The lateral resolution of these acquisitions is controlled by the width of the first Fresnel zone, taking advantage of their positions close to the sea bottom. No current existing deep towed equipment can benefit from seismic imaging processing techniques to improve this resolution as a consequence of positioning inaccuracies. The technological developments of a digital deep-towed multichannel streamer are presented with a particular attention to positioning: each hydrophone incorporates a pitch, roll and heading sensor in order to monitor the constant deformation of the streamer in operation. The sea trials took place in July 2013 in the Mediterranean Sea. Pre-stack depth migration applied to the deep-towed multichannel data illustrates the potential of this emerging methodology in terms of penetration (12 dB improvement in Signal/Noise) and lateral resolution (mean signal wavelength: 3 m) when compared with deep-towed single-channel acquisition.

Marsset, B.; Menut, E.; Ker, S.; Thomas, Y.; Regnault, J.-P.; Leon, P.; Martinossi, H.; Artzner, L.; Chenot, D.; Dentrecolas, S.; Spychalski, B.; Mellier, G.; Sultan, N.

2014-11-01

296

High resolution simulation of the South Asian monsoon using a variable4 resolution global climate model5  

E-print Network

1 1 2 3 High resolution simulation of the South Asian monsoon using a variable4 resolution global of the South Asian monsoon rainfall distribution and the interactions27 between monsoon circulation of resolution on the overall quality of the simulated regional33 monsoon fields. It is found that the monsoon

Dufresne, Jean-Louis

297

HIRDES The High-Resolution Double-Echelle Spectrograph for WSO-UV  

E-print Network

- resolution echelle spectrographs ­ the High-Resolution Double-Echelle Spectrograph (HIRDES) ­ and a low-dispersion Observatory (WSO-UV) will provide future access to high-resolution far-UV spectroscopy. WSO

Barnstedt, Jürgen

298

High-resolution ultrasonic imaging using an etalon detector array  

PubMed Central

A photoacoustic imaging system was built and tested to demonstrate the feasibility of high-resolution low-noise ultrasonic imaging based on parallel detection using polymer etalons. Its capability of detecting ultrasound at different elements simultaneously in the optical end was verified by imaging three 49 ?m beads. An average noise-equivalent pressure of 3.6 kPa over 50 MHz for 50 ?m diameter detection elements in a two-dimensional array with a diameter of 1.35 mm and a detection bandwidth of 75 MHz at 3 dB was measured. These results demonstrate the potential of polymer etalons for high-frame-rate high-resolution three-dimensional photoacoustic and ultrasound pulse-echo imaging. PMID:19529842

Huang, Sheng-Wen; Hou, Yang; Ashkenazi, Shai; O'Donnell, Matthew

2008-01-01

299

Coronal Heating and the Need for High-Resolution Observations  

NASA Technical Reports Server (NTRS)

Despite excellent progress in recent years in understanding coronal heating, there remain many crucial questions that are still unanswered. Limitations in the observations are one important reason. Both theoretical and observational considerations point to the importance of small spatial scales, impulsive energy release, strong dynamics, and extreme plasma nonuniformity. As a consequence, high spatial resolution, broad temperature coverage, high temperature fidelity, and sensitivity to velocities and densities are all critical observational parameters. Current instruments lack one or more of these properties, and this has led to considerable ambiguity and confusion. In this talk, I will discuss recent ideas about coronal heating and emphasize that high spatial resolution observations, especially spectroscopic observations, are needed to make major progress on this important problem.

Klimchuk, James A.

2008-01-01

300

The Gaia FGK Benchmark Stars - High resolution spectral library  

E-print Network

Context. An increasing number of high resolution stellar spectra is available today thanks to many past and ongoing spectroscopic surveys. Consequently, numerous methods have been developed in order to perform an automatic spectral analysis on a massive amount of data. When reviewing published results, biases arise and they need to be addressed and minimized. Aims. We are providing a homogeneous library with a common set of calibration stars (known as the Gaia FGK Benchmark Stars) that will allow to assess stellar analysis methods and calibrate spectroscopic surveys. Methods. High resolution and signal-to-noise spectra were compiled from different instruments. We developed an automatic process in order to homogenize the observed data and assess the quality of the resulting library. Results. We built a high quality library that will facilitate the assessment of spectral analyses and the calibration of present and future spectroscopic surveys. The automation of the process minimizes the human subjectivity and e...

Blanco-Cuaresma, S; Jofr, P; Heiter, U

2014-01-01

301

High-resolution ionization detector and array of such detectors  

DOEpatents

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.

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

2001-01-16

302

High energy resolution scintillators for nuclear nonproliferation applications  

NASA Astrophysics Data System (ADS)

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.

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

2014-09-01

303

High-resolution electron microscopy of advanced materials  

SciTech Connect

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.

Mitchell, T.E.; Kung, H.H.; Sickafus, K.E.; Gray, G.T. III; Field, R.D.; Smith, J.F. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.

1997-11-01

304

MISTIGRI instrumental concept for high-resolution thermal infrared imaging  

NASA Astrophysics Data System (ADS)

High resolution images in the Thermal infrared provide a way to detect irrigated fields, to measure evapo-transpiration and detect plant water stress. Models and algorithms have largely improved to yield very good results. However the only in-orbit satellites providing high resolution images in the thermal infrared domain (Landsat, Aster) are long beyond their design lifetime. Furthermore, they do not provide frequent acquisitions (1 image every 16 days for Landsat and Aster, while 1 image per couple of days would be required to monitor plant water stress). There is indeed a need for high resolution and high repetitivity thermal infrared data for hydrological applications. CNES carried out a feasibility study of such a mission on a microsatellite. The mission is called MISTIGRI (MicroSatellite for Thermal InfraRed Ground Surface Imaging). The preliminary payload design was performed by Thales Alenia Space for CNES. An instrumental concept was proposed which fulfils the mission requirements. The study addressed both cooled and uncooled solutions, although a micro-bolometer detector was preferred after trade-off. This paper addresses the results of the MISTIGRI payload feasibility study; it presents the mission requirements, the proposed instrumental concept, describes the major subsystems and provides the preliminary performance budgets.

Tint Garcia-Moreno, F.; Fargant, G.; Guerin, F.; Israbian, C.; Mathieu, J. C.; Michaud, J.; Bardoux, A.; Hagolle, O.; Lagouarde, J. P.

2009-08-01

305

High spatial resolution measurements in a single stage ram accelerator  

NASA Technical Reports Server (NTRS)

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.

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

1992-01-01

306

Towards Ultra-High Resolution Models of Climate and Weather  

SciTech Connect

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

Wehner, Michael; Oliker, Leonid; Shalf, John

2007-01-01

307

High-resolution 3D digital models of artworks  

NASA Astrophysics Data System (ADS)

The measurement of the shape of an artwork usually requires a high-resolution instrumentation, in order to catch small details such as chisel marks, sculptural relieves, surface cracks, etc. 3D scanning techniques, together with new modeling software tools, allow a high fidelity reproduction of an artwork: these can be applied either to support and document its repair or for the realization of 3D archives and virtual museums. Starting from a high-resolution digital model of an object, a further step could be its reproduction by means of fast-prototyping techniques like stereo-lithography or electro-erosion. This work is aimed at showing the performance of a high-resolution laser scanner devoted to Cultural Heritage applications. The device is portable and very versatile, in order to allow in situ applications, accurate and reliable, so to capture intricate details. This laser profilometer has been used in a few surveys, the most significant of which are the monitoring the various phases of the restoration process of an ellenistic bronze (the Minerva of Arezzo, Florence), the cataloguing of some archaeological findings (from the Grotta della Poesia, Lecce) and the documenting of wooden panels surface conditions (the "Madonna del Cardellino" by Raffaello and "La Tebaide" by Beato Angelico).

Fontana, Raffaella; Gambino, Maria Chiara; Greco, Marinella; Pampaloni, Enrico; Pezzati, Luca; Scopigno, Roberto

2003-10-01

308

High-resolution Interferometer Sounder (HIS), phase 2  

NASA Technical Reports Server (NTRS)

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.

1988-01-01

309

Proceedings of the 2004 High Spatial Resolution Commercial Imagery Workshop  

NASA Technical Reports Server (NTRS)

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.

2006-01-01

310

High-resolution 3T MR neurography of radial neuropathy.  

PubMed

The radial nerve is a continuation of the posterior cord of the brachial plexus and one of the major nerves that provide motor and sensory innervations to the forearm. MR imaging evaluation of the radial nerve pathology has been described in scattered case reports. Current high-field MR scanners enable high resolution and high contrast imaging of the peripheral nerves. This article reviews the 3 Tesla magnetic resonance neurography imaging of radial nerve anatomy and various pathologies affecting it with relevant case examples. PMID:21782245

Faridian-Aragh, Neda; Chalian, Majid; Soldatos, Theodoros; Thawait, Gaurav K; Deune, E Gene; Belzberg, Allan J; Carrino, John A; Chhabra, Avneesh

2011-12-01

311

Holographic Imaging: A Versatile Tool for High Angular Resolution Imaging  

NASA Astrophysics Data System (ADS)

Speckle holography can be used to reconstruct high angular resolution images from long series of short exposures if the point spread function (PSF) from each frame can be measured reliably. We show that through use of multiple reference stars and iterative PSF subtraction, we can obtain highly accurate PSFs. The technique is optimised for crowded fields and results in images with excellent cosmetics and high Strehl ratio from the optical to the mid-infrared regimes. With examples from NACO, VISIR, and HAWK-I we show that holography opens up novel and unforeseen possibilities and can be an attractive alternative to adaptive optics.

Schdel, R.; Girard, J. H.

2012-12-01

312

High resolution reservoir geological modelling using outcrop information  

SciTech Connect

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.

Zhang Changmin; Lin Kexiang; Liu Huaibo [Jianghan Petroleum Institute, Hubei (China)] [and others

1997-08-01

313

High Resolution Terahertz Spectroscopy with Quantum Cascade Lasers  

NASA Astrophysics Data System (ADS)

High resolution terahertz (THz) spectroscopy is a powerful analytical tool for laboratory purposes as well as for remote sensing in astronomy, planetary research, and Earth observation. THz quantum cascade lasers (QCLs) are promising sources for implementation into THz spectrometers, in particular at frequencies above 3 THz, which is the least explored portion of the THz region. One application of QCLs in THz spectroscopy is in absorption spectrometers, where they can replace less powerful and somewhat cumbersome sources based on frequency mixing with gas lasers. Another one is using a QCL as local oscillator in a heterodyne spectrometer for remote sensing. This article will review the state-of-the art in high resolution THz spectroscopy with QCLs.

Hbers, H.-W.; Eichholz, R.; Pavlov, S. G.; Richter, H.

2013-06-01

314

High resolution computed tomography of advanced composite and ceramic materials  

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

315

High-Resolution Multisensor Infrastructure Inspection with Unmanned Aircraft Systems  

NASA Astrophysics Data System (ADS)

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.

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

2013-08-01

316

A high resolution spectral atlas of brown dwarfs  

E-print Network

We present a UVES/VLT high resolution atlas of three L dwarfs and one T dwarf system, spectral classes at which most of the objects are brown dwarfs. Our atlas covers the optical region from H$\\alpha$ up to the near infrared at 1 $\\mu$m. We present spectral details of ultra-cool atmospheres at very high resolution ($R \\sim 33 000$) and compare the spectra to model calculations. Our comparison shows that molecular features from VO and CaH, and atomic features from Cs and Rb are reasonably well fit by current models. On the other hand, features due to TiO, CrH, and water, and atomic Na and K reveal large discrepancies between model calculations and our observations.

A. Reiners; D. Homeier; P. H. Hauschildt; F. Allard

2007-07-18

317

High-resolution array processing using implicit eigenvector weighting techniques  

SciTech Connect

Many high-resolution bearing estimators require the explicit calculation of the eigenvectors and eigenvalues of the cross-spectral matrix of the sensor outputs. Once the eigenvectors have been calculated, various different estimators can be derived by altering the eigenvalues to give a re-weighing of the eigenvectors. For example, in the MUSIC method the eigenvalues corresponding to those eigenvectors in the noise subspace are set to unity, while the eigenvalues corresponding to those eigenvectors in the signal subspace are set to zero. These weighing functions are reminiscent of ideal filter responses in analog filter theory, where practical filters are designed by using polynomial approximations to the ideal desired response. In this paper, the approximation theory developed for filter design is used to derive high-resolution bearing estimators that do not require explicit calculation of the eigenvectors.

Steele, A.K. (Maritime Systems Div., Weapons Systems Research Lab., Defense Science and Technology Organization, Salisbury, SA 5108 (AU)); Byrne, C.L. (Dept. of Mathematics, Univ. of Lowell, Lowell, MA (US))

1990-01-01

318

High-resolution scanning surface-plasmon microscopy.  

PubMed

Surface plasmons (SP's) are electromagnetic surface waves that propagate along the interface between conductors and dielectrics. The k vector of these waves is larger than the free-space wave vector. The importance of SP's lies in the fact that they are extremely sensitive to small changes in the dielectric properties of substances that are in contact with the conductors. This property means that SP's have many sensor applications; however, when they are used in microscopic applications the lateral resolution is limited to several micrometers. We discuss how this limit can be overcome by use of defocused high-numerical-aperture liquid-immersion objectives. We also present SP images that demonstrate a resolution comparable with that expected from high-numerical-aperture optical microscopes. Finally, we discuss how ultrahigh-numerical-aperture objectives with numerical apertures greater than 1.5 can be expected to have considerable influence on biological imaging. PMID:18354636

Somekh, M G; Liu, S; Velinov, T S; See, C W

2000-12-01

319

High-resolution ultrasound imaging of cutaneous lesions  

PubMed Central

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

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

2013-01-01

320

The High Energy Resolution View of Warm Absorbers  

NASA Astrophysics Data System (ADS)

A number of emission and absorption features are expected to be visible in high energy resolution X-ray spectra of type 1 AGN with ionized gas along the line of sight (so called "warm absorbers"). Emission strongly depends on the geometrical configuration of the gas, while absorption along the line of sight does not. Absorption features include photoelectric absorption K and L edges along with many strong K$\\alpha$, K$\\beta$ and L resonance absorption lines from the most abundant elements. We present detailed simulations of our ``photoelectric + resonant absorption'' model with the high energy resolution gratings and calorimeters of AXAF, XMM and Constellation-X, and discuss the relevant physics which can be addressed with the new generation of X-ray spectrometers.

Nicastro, F.; Fiore, F.; Matt, G.

321

High Resolution Scanning Electron Microscopy of Cells Using Dielectrophoresis  

PubMed Central

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

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

2014-01-01

322

High-resolution compact X-ray microscopy.  

PubMed

We demonstrate compact full-field soft X-ray transmission microscopy with sub 60-nm resolution operating at lambda= 2.48 nm. The microscope is based on a 100-Hz regenerative liquid-nitrogen-jet laser-plasma source in combination with a condenser zone plate and a micro-zone plate objective for high-resolution imaging onto a 2048 x 2048 pixel CCD detector. The sample holder is mounted in a helium atmosphere and allows imaging of both dry and wet specimens. The microscope design enables fast sample switching and the sample can be pre-aligned using a visible-light microscope. High-quality images can be acquired with exposure times of less than 5 min. We demonstrate the performance of the microscope using both dry and wet samples. PMID:17444946

Takman, P A C; Stollberg, H; Johansson, G A; Holmberg, A; Lindblom, M; Hertz, H M

2007-05-01

323

High-resolution manometry for the evaluation of gastric motility.  

PubMed

This review focus on the utility of HRM for the evaluation of gastric motility. The evaluation of gastric motility has clinical implications for the study of a myriad of diseases. Disordered motility represents a spectrum of dysfunction ranging from delayed gastric emptying to abnormally rapid gastric transit. Gastric motility may be measured by a variety of methods with different efficacy and different variables that may be obtained. High-resolution manometry was created and added to the diagnostic armamentarium. The methods and outcomes for the study of proximal motility that may be useful to assess the thoracoabdominal pressure gradient, gastric filling and accommodation are described. Also, studies on antroduodenal manometry are reviewed. High-resolution manometry allows gastric manometry without technical limitations found on conventional manometry; however, studies are still on the phase of understanding the normal findings. PMID:25106472

Herbella, Fernando Augusto Mardiros; Aprile, Lilian R O; Patti, Marco G

2014-09-01

324

HIGH SPATIAL RESOLUTION OBSERVATIONS OF LOOPS IN THE SOLAR CORONA  

SciTech Connect

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.

Brooks, David H.; Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Winebarger, Amy R. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States)

2013-08-01

325

Measuring Large-Scale Social Networks with High Resolution  

PubMed Central

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 yearsthe 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

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

2014-01-01

326

High energy resolution, high angular acceptance crystal monochromator  

DOEpatents

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.

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

1996-06-04

327

High energy resolution, high angular acceptance crystal monochromator  

DOEpatents

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.

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

1996-06-04

328

Compact High-Velocity Clouds at High Resolution  

E-print Network

Six examples of the compact, isolated high-velocity clouds catalogued by Braun & Burton (1999) and identified with a dynamically cold ensemble of primitive objects falling towards the barycenter of the Local Group have been imaged with the Westerbork Synthesis Radio Telescope; an additional ten have been imaged with the Arecibo telescope. The imaging reveals a characteristic core/halo morphology: one or several cores of cool, relatively high-column-density material, are embedded in an extended halo of warmer, lower-density material. Several of the cores show kinematic gradients consistent with rotation; these CHVCs are evidently rotationally supported and dark-matter dominated. The imaging data allows several independent estimates of the distances to these objects, which lie in the range 0.3 to 1.0 Mpc. The CHVC properties resemble what might be expected from very dark dwarf irregular galaxies.

W. B. Burton; Robert Braun

1999-12-22

329

Cavity detection using high-resolution seismic reflection methods  

Microsoft Academic Search

Surface collapse over abandoned sub-surface coal mines continues to be a problem in many parts of the world. High-resolution P-wave reflection seismology was successfully used to locate water-filled cavities in a 1-m (3-ft) thick coal seam at depths of 9 m (29 ft) in southeastern Kansas. A dominant frequency of 275 Hz was attained enabling us to delineate the top

K. L. Branham; D. W. Steeples

1988-01-01

330

Enceladus Heat Flow from High Spatial Resolution Thermal Emission Observations  

NASA Astrophysics Data System (ADS)

We estimate the total power radiated from Enceladus' tiger stripes, using Cassini CIRS observations with spatial resolution high enough to separate the active tiger stripe emission from the background. The resulting radiated power, 4.2 GW (to which should be added 0.5 GW of plume latent heat and possible inter-stripe emission), is lower than previous estimates based on the integrated south polar emission, though still higher than expected from steady-state tidal heating.

Spencer, J. R.; Howett, C. J. A.; Verbiscer, A.; Hurford, T. A.; Segura, M.; Spencer, D. C.

2013-09-01

331

Large-field high-resolution mosaic movies  

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

332

Two-dimensional high-resolution stepper image monitor  

Microsoft Academic Search

A two-dimensional image monitor with high resolution has been implemented on a deep-UV 0.6 NA stepper. The aerial intensity sensor uses a photodiode which is integrated in the wafer chuck and a chromium coated quartz wafer with an array of 0.2 micrometers pinholes. The aerial image is scanned by the sensor which is positioned by the stepper stage. The image

Anton K. Pfau; Richard Hsu; William G. Oldham

1992-01-01

333

High-resolution photography of the solar chromosphere  

Microsoft Academic Search

High-resolution filtergrams of an active region loop taken at seven wavelengths in Ha have been used to derive the contrast at eleven locations along its length as a function of wavelength. With an appropriate choice of parameters, theoretical curves calculated on the basis of the cloud model give a reasonable fit to the observed contrast profiles. The inferred line-of-sight components

R. J. Bray; R. E. Loughhead

1983-01-01

334

High-resolution photography of the solar chromosphere  

Microsoft Academic Search

High-resolution filtergrams of the quiet chromosphere, taken at seven wavelengths in Ha with the aid of a computer-controlled 1\\/8 filter, have been used to derive the contrast of ten bright and dark mottles as functions of wavelength. The contrast profiles of bright and dark mottles are strikingly different. They disagree with Athay's (1970) velocity model but, with an appropriate

R. J. Bray

1973-01-01

335

High-resolution photography of the solar chromosphere  

Microsoft Academic Search

High-resolution filtergrams of a sunspot and its surroundings, taken at seven wavelengths in Ha with the aid of a computer-controlled 1\\/8 filter, have been used to derive the contrast of ten sunspot superpenumbra fibrils as functions of wavelength. The observed contrast profiles are compared with profiles calculated on the basis of three theoretical models, namely, Beckers' (1964) cloud model,

R. J. Bray

1974-01-01

336

Development of High Spectral Resolution Lidar (HSRL) technology  

Microsoft Academic Search

This report describes progress achieved during two years of DOE funding provided by grant DE-FG02-90ER61058. This grant was titled 'Development of High Spectral Resolution Lidar Technology for use in the DOE ARM Program'. Nearly all grant objectives were achieved despite the fact that DOE abruptly cancelled funding after only two years of a planned three year effort. The principal investigator

Edwin W. Eloranta

1995-01-01

337

Development of high spectral resolution lidar (HSRL) technology. Final report  

Microsoft Academic Search

This report describes progress achieved during two years of DOE funding provided by grant DE-FG02-90ER61058. This grant was titled {open_quotes}Development of High Spectral Resolution Lidar Technology for use in the DOE ARM Program{close_quotes}. Nearly all grant objectives were achieved despite the fact that DOE abruptly canceled funding after only two years of a planned three year effort. The principal investigator

Eloranta

1995-01-01

338

Digital analysis of high-resolution fundus images  

Microsoft Academic Search

High resolution digital color fundus images were used to investigate the tapetal-like reflex, a retinal reflection uniquely present in carriers of X-linked retinitis pigmentosa (XLRP). A Zeiss fundus camera and color transparency film were used for the fundus photography, and a slide scanner was used to digitize the color slides (6$\\\\mu$m\\/pixel). A model of the imaging system was derived based

Artur Vahe Cideciyan

1992-01-01

339

High resolution chromosome banding in the Norway rat, Rattus norvegicus  

Microsoft Academic Search

High resolution banded chromosomes were prepared from a synchronized culture of rat fibroblasts. A maximum of 457 bands per haploid chromosome set were observed. This represents a two-fold increase when compared to the number of bands visualized in mid-metaphases using standard procedures. By reference to both G- and Q-banded karyotypes, we constructed improved idiograms of rat chromosomes at 300- and

H. Satoh; M. C. Yoshida; M. Sasaki

1989-01-01

340

High-resolution solar spectroscopy in the undergraduate physics laboratory  

NASA Astrophysics Data System (ADS)

The richness of the solar spectrum at visible wavelengths makes it ideally suited for many laboratory exercises in optical spectroscopy. A number of such experiments taking advantage of a high-resolution scanning spectrometer are described as they have been performed by seniors at Middlebury College. Physical principles emphasized include optical depth, the nature of molecular spectra, the Doppler effect, and the Zeeman effect. These experiments are suitable for advanced undergraduate physics and astronomy majors.

Ratcliff, Stephen J.; Noss, Darcy K.; Dunham, Jeffrey S.; Anthony, Eric B.; Cooley, John H.; Alvarez, Alberto

1992-07-01

341

High-Resolution Brain SPECT Imaging in ADHD  

Microsoft Academic Search

Children and adolescents with ADHD were evaluated with high-resolution brain SPECT imaging to determine if there were similarities between reported PET and QEEG findings. Fifty-four children and adolescents with ADHD by DSM-III-R and Conners Rating Scale criteria were evaluated. A non-ADHD control group was also studied with SPECT. Two brain SPECT studies were done on each group, a resting study

Daniel G. Amen; Blake D. Carmichael

1997-01-01

342

An EMD-IHS model for high resolution image fusion  

Microsoft Academic Search

High resolution image fusion is a significant focus in the field of the image processing. A new image fusion model is presented based on the characteristic level of Empirical Mode Decomposition (EMD). The IHS transform of the multi-spectral image firstly gives the intensity image. Thereafter, the 2D EMD in terms of row-column extension of the 1D EMD model was used

Jian Wang; Changhui Xu; Jixian Zhang; Zhengjun Liu

2007-01-01

343

An EMD-IHS model for high resolution image fusion  

NASA Astrophysics Data System (ADS)

High resolution image fusion is a significant focus in the field of the image processing. A new image fusion model is presented based on the characteristic level of Empirical Mode Decomposition (EMD). The IHS transform of the multi-spectral image firstly gives the intensity image. Thereafter, the 2D EMD in terms of row-column extension of the 1D EMD model was used to decompose the detail scale image and coarse scale image from the high resolution band image and the intensity image. At last, fused intensity image is obtained by reconstruction with high frequency of high-resolution image and low frequency of intensity image and IHS inverse transform result in fused image. After presenting EMD principle, multi-scale decomposition and reconstruction algorithm of 2D EMD is defined and fusion technique scheme is advanced based on EMD. Panchromatic band and multi-spectral band3,2,1 of QUICKBIRD are used to assess the quality of the fusion algorithm. After selecting appropriate Intrinsic Mode Function(IMF) for the merger on the basis of EMD analysis on specific row (colum) pixel gray value series, the fusion scheme gives fused image, which is compared with generally used fusion algorithms (Wavelet, IHS,Brovey). The objectives of image fusion include enhancing the visibility of the image and improving the spatial resolution and the spectral information of the original images. For assessing quality of an image after fusion, information entropy and standard deviation are applied to assess spatial details of the fused images and correlation coefficient, bias index and warping degree for measuring distortion between the original image and fused image in terms of spectral information. For all proposed fusion algorithms, better results are obtained when EMD algorithm is used to perform the fusion experience.

Wang, Jian; Xu, Changhui; Zhang, Jixian; Liu, Zhengjun

2007-06-01

344

High-Resolution Reflectometry by Optical Multidigitized Coherence  

NASA Astrophysics Data System (ADS)

We propose and confirm a novel technique of optical frequency domain reflectometry based on multidigitized coherence using a multimode laser. The proposed system can easily provide the potential for high resolution on the order of 10 ?m without scanning frequencies as in frequency domain reflectometers of either continuous or stepwise sweep. The theoretical approach agrees well with the experimental results demonstrated using a commercially available multimode laser diode.

Ichimura, Tsutomu; Anndo, Naoki; Funaba, Tadayuki; Endo, Shigeru; Odagiri, Yoshiki; Tan-No, Naohiro; Inaba, Humio

1996-01-01

345

Using High Resolution Balloon Photography to Provide Topographic Data  

Microsoft Academic Search

For site-scale projects, the Bureau of Reclamation has used low altitude balloon photogrammetry to obtain high-resolution photographs and detailed topographic information. These data are collected in a fraction of the time and effort it would take to obtain a similar level of detail using traditional methods. This is accomplished at a significantly reduced cost compared to flying LiDAR or aerial

K. Russell; T. Bauer

2009-01-01

346

A new matching algorithm for high resolution mass spectra  

Microsoft Academic Search

We present a new matching algorithm designed to compare high-resolution spectra. Whereas existing methods are bound to compare\\u000a fixed intervals of ion masses, the accurate mass spectrum (AMS) distance method presented here is independent of any alignment.\\u000a Based on the Jeffreys-Matusitas (JM) distance, a difference between observed peaks across pairs of spectra can be calculated,\\u000a and used to find a

Michael Edberg Hansen; Jrn Smedsgaard

2004-01-01

347

High-Resolution, Real-time 3D Shape Acquisition  

Microsoft Academic Search

In this paper we describe a high-resolution, real-time 3D shape acquisition system based on structured light techniques. This system uses a color pattern whose RGB channels are coded with either sinusoidal or trapezoidal fringe patterns. When projected by a modified DLP projector (color filters removed), this color pattern results in three grayscale patterns projected sequentially at a frequency of 240

Song Zhang; Peisen Huang

2004-01-01

348

High-resolution genomic profiles of human lung cancer  

Microsoft Academic Search

Lung cancer is the leading cause of cancer mortality worldwide, yet there exists a limited view of the genetic lesions driving this disease. In this study, an integrated high-resolution survey of regional amplifications and deletions, coupled with gene-expression profiling of non-small-cell lung cancer subtypes, adenocarcinoma and squamous-cell carcinoma (SCC), identified 93 focal copy-number alterations, of which 21 span <0.5 megabases

Giovanni Tonon; Kwok-Kin Wong; Gautam Maulik; Cameron Brennan; Bin Feng; Yunyu Zhang; Deepak B. Khatry; Alexei Protopopov; Mingjian James You; Andrew J. Aguirre; Eric S. Martin; Zhaohui Yang; Hongbin Ji; Lynda Chin; Ronald A. DePinho

2005-01-01

349

ccsd00003163, High Resolution Helike Argon And Sulfur Spectra From  

E-print Network

ccsd­00003163, version 1 ­ 26 Oct 2004 High Resolution He­like Argon And Sulfur Spectra From of Aveiro, Portugal Abstract. We present new results on the X­ray spectroscopy of multicharged argon, sulfur of multicharged F­like to He­like argon, sulfur and chlorine with one 1s hole. In particular, we observed the 1s2s

350

Distance-based tractography in high angular resolution diffusion MRI  

Microsoft Academic Search

High angular resolution diffusion imaging (HARDI) is a magnetic resonance imaging (MRI) technique, determining the diffusion\\u000a of water molecules in tissue in vivo. HARDI is advantageous over the well-known diffusion tensor imaging (DTI), since it is\\u000a able to extract more than one fiber orientation within a voxel and can therefore resolve crossing, kissing or fanning fiber\\u000a tracts. However, multiple orientations

Diana Rttger; Viktor Seib; Stefan Mller

2011-01-01

351

High resolution melting analysis of almond SNPs derived from ESTs  

Microsoft Academic Search

High resolution melting curve (HRM) is a recent advance for the detection of SNPs. The technique measures temperature induced\\u000a strand separation of short PCR amplicons, and is able to detect variation as small as one base difference between samples.\\u000a It has been applied to the analysis and scan of mutations in the genes causing human diseases. In plant species, the

Shu-Biao Wu; Michelle G. Wirthensohn; Peter Hunt; John P. Gibson; Margaret Sedgley

2008-01-01

352

High-resolution conjunctival contrast-enhanced MRI dacryocystography  

Microsoft Academic Search

We assessed high-resolution MRI of the lacrimal system with conjunctival contrast enhancement in patients with suspected\\u000a stenosis. We studied 18 patients with epiphora affecting 22 eyes, using a surface coil, before and after conjunctival and\\u000a intravenous Gd-DTPA. Stenosis or obstruction of the ducts was found in 18 of 22 cases: at canalicular level in 3 cases, at\\u000a the sac in

K. T. Hoffmann; N. Hosten; N. Anders; C. Stroszczynski; T. Liebig; C. Hartmann; R. Felix

1999-01-01

353

High-Resolution Spherical Quantization of Sinusoidal Parameters  

Microsoft Academic Search

Sinusoidal coding is an often employed technique in low bit-rate audio coding. Therefore, methods for efficient quantization of sinusoidal parameters are of great importance. In this paper, we use high-resolution assumptions to derive analytical expressions for the optimal entropy-constrained unrestricted spherical quantizers for the amplitude, phase, and frequency parameters of the sinusoidal model. This is done both for the case

Pim Korten; Jesper Jensen; Richard Heusdens

2007-01-01

354

8500-8750{AA} high resolution spectroscopy (Munari+, 1999)  

Microsoft Academic Search

We present an Echelle+CCD high resolution spectroscopic atlas mapping the MKK classification system over the wavelength interval lambda 8500-8750 A, centered on the near-IR triplet of Ca II. Table 2 lists all the 131 program stars with basic informations (magnitudes, coordinates, spectral types, metallicities, rotational velocities, variabilities) and the journal of observations; Table 3 shows our mapping of the MKK

U. Munari; L. Tomasella

1999-01-01

355

High real-space resolution structure of materials by high-energy x-ray diffraction  

SciTech Connect

Results of high-energy synchrotrons radiation experiments are presented demonstrating the advantages of the atomic Pair Distribution Function technique in determining the structure of materials with high resolution.

Petkov, V.; Billinge, S. J. L.; Heising, J.; Kanatzidis, M. G.; Shastri, S.; Kycia, S.

1999-12-10

356

Infrared land surface remote sensing using high spectral resolution observations  

NASA Astrophysics Data System (ADS)

This study presents a new technique for the separation of land surface infrared emissivity and surface skin temperature using high spectral resolution infrared observations. High spectral resolution observations of upwelling radiance at 20 km altitude were obtained by the Scanning High-resolution Interferometer Sounder (S-HIS) aboard the NASA ER-2 aircraft during the TX-2001 experiment. These aircraft observations are used in conjunction with complementary ground-based observations of downwelling radiance at the surface to estimate the surface skin temperature and absolute emissivity for a region in north central Oklahoma, USA. Coincident MODIS Airborne Simulator (MAS) observations are used to quantify the land surface variability within the S-HIS scene in the vicinity of the DOE ARM Southern Great Plain central facility. Ground truth data is presented from a ground based Scanning Atmospheric Emitted Radiance Interferometer. This remote sensing technique has application to satellite based observations from the NASA AIRS, the NPOESS CrIS, the EUMETSAT IASI, and the NASA GIFTS instruments.

Knuteson, Robert O.; Deslover, Daniel H.; Larar, Allen M.; Osborne, Brian; Revercomb, Henry E.; Short, John F.; Smith, William L.; Tanamachi, Robin

2003-06-01

357

High resolution NMR spectroscopy in the Earth's magnetic field  

NASA Astrophysics Data System (ADS)

High resolution nuclear magnetic resonance (NMR) spectroscopy at high magnetic fields has developed into a most powerful tool for the determination of molecular structures. The dream is a mobile molecular low field NMR scanner which allows the determination of molecular structures. Until to now at low magnetic fields NMR spectroscopy suffers from the low signal to noise ratio (S/N) and from the lack of access to chemical information in terms of chemical shifts and homo-nuclear J-couplings. We demonstrate that chemical analysis of liquids is possible by mobile ultrahigh-resolution ^1H, ^19F and ^129Xe NMR spectroscopy in the Earth's magnetic field. The ^129Xe chemical shift in liquids is determined in the Earth's magnetic field with a precision comparable to that obtained by superconducting magnets. The ^1H and ^19F NMR spectra allow the determination of hetero-nuclear J-coupling constants with an accuracy of a few mHz. Very fine details of the molecular structure which are not observable with conventional superconducting magnets can be discriminated. For molecules where a rare spin such as carbon ^13C is present the high-resolution low-field ^1H NMR spectrum indeed reveal all hetero- and homo-nuclear J-couplings. All these results open the door for the mobile study of molecular structures as well as for the online monitoring of chemical reactions at ultra-low magnetic fields.

Appelt, Stephan

2007-03-01

358

High frequency resolution terahertz time-domain spectroscopy  

NASA Astrophysics Data System (ADS)

A new method for the high frequency resolution terahertz time-domain spectroscopy is developed based on the characteristic matrix method. This method is useful for studying planar samples or stack of planar samples. The terahertz radiation was generated by optical rectification in a ZnTe crystal and detected by another ZnTe crystal via electro-optic sampling method. In this new characteristic matrix based method, the spectra of the sample and reference waveforms will be modeled by using characteristic matrices. We applied this new method to measure the optical constants of air. The terahertz transmission through the layered systems air-Teflon-air-Quartz-air and Nitrogen gas-Teflon-Nitrogen gas-Quartz-Nitrogen gas was modeled by the characteristic matrix method. A transmission coefficient is derived from these models which was optimized to fit the experimental transmission coefficient to extract the optical constants of air. The optimization of an error function involving the experimental complex transmission coefficient and the theoretical transmission coefficient was performed using patternsearch algorithm of MATLAB. Since this method takes account of the echo waveforms due to reflections in the layered samples, this method allows analysis of longer time-domain waveforms giving rise to very high frequency resolution in the frequency-domain. We have presented the high frequency resolution terahertz time-domain spectroscopy of air and compared the results with the literature values. We have also fitted the complex susceptibility of air to the Lorentzian and Gaussian functions to extract the linewidths.

Sangala, Bagvanth Reddy

359

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

NASA Technical Reports Server (NTRS)

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.

Putman, William P.

2012-01-01

360

High-resolution high-speed panoramic cardiac imaging system.  

PubMed

A panoramic cardiac imaging system consisting of three high-speed CCD cameras has been developed to image the surface electrophysiology of a rabbit heart via fluorescence imaging using a voltage-sensitive fluorescent dye. A robust, unique mechanical system was designed to accommodate the three cameras and to adapt to the requirements of future experiments. A unified computer interface was created for this application - a single workstation controls all three CCD cameras, illumination, stimulation, and a stepping motor that rotates the heart. The geometric reconstruction algorithms were adapted from a previous cardiac imaging system. We demonstrate the system by imaging a polymorphic cardiac tachycardia. PMID:18334422

Evertson, Dale W; Holcomb, Mark R; Eames, Matthew C; Bray, Mark-Anthony; Sidorov, Veniamin Y; Xu, Junkai; Wingard, Holley; Dobrovolny, Hana M; Woods, Marcella C; Gauthier, Daniel J; Wikswo, John P

2008-03-01

361

High-resolution high-speed panoramic cardiac imaging system  

PubMed Central

A panoramic cardiac imaging system consisting of three high-speed CCD cameras has been developed to image the surface electrophysiology of a rabbit heart via fluorescence imaging using a voltage-sensitive fluorescent dye. A robust, unique mechanical system was designed to accommodate the three cameras and to adapt to the requirements of future experiments. A unified computer interface was created for this application a single workstation controls all three CCD cameras, illumination, and stimulation, and the stepping motor rotates the heart. The geometric reconstruction algorithms were adapted from a previous cardiac imaging system. We demonstrate the system by imaging a polymorphic cardiac tachycardia. PMID:18334422

Evertson (In Memoriam), Dale W.; Holcomb, Mark R.; Eames, Matthew D.C.; Bray, Mark-Anthony P.; Sidorov, Veniamin Y.; Xu, Junkai; Wingard, Holley; Dobrovolny, Hana M.; Woods, Marcella C.; Gauthier, Daniel J.; Wikswo, John P.

2008-01-01

362

High-resolution imaging of compact high-velocity clouds  

E-print Network

Six examples of the compact, isolated high-velocity HI clouds (CHVCs) identified by Braun and Burton (1999) have been imaged with the WSRT. The 65 confirmed objects in this class define a dynamically cold system, with a global minimum for the velocity dispersion of only 70 km/s, found in the Local Group Standard of Rest, while in-falling at 100 km/s toward the LG barycenter. These objects have a characteristic morphology, in which several compact cores are embedded in a diffuse halo. The compact cores typically account for 40% of the HI line flux while covering some 15% of the source area. The cores are the cool condensed phase of HI, the CNM, with temp. near 100 K, while the halos appear to be a shielding column of warm diffuse HI, the WNM, with temp. near 8000 K. We detect a core with one of the narrowest HI emission lines ever observed, with intrinsic FWHM of 2 km/s and 75 K brightness. From a comparison of column and volume densities we derive a distance in the range 0.5 to 1 Mpc. We determine a metallicity for this same object of 0.04 to 0.07 solar. Comparably high distances are implied by demanding the stability of objects with multiple cores, which show relative velocities as large as 70 km/s on 30 arcmin scales. Many compact cores show systematic velocity gradients along the major axis of their elliptical extent which are consistent with circular rotation. Several of the derived rotation curves are well-fit by Navarro, Frenk, and White (1997) cold dark matter profiles. These kinematic signatures imply a high dark-to-visible mass ratio of 10-50, for D=0.7Mpc, which scales as 1/D. The implied dark matter halos dominate the mass volume density within the central 2 kpc (10 arcmin) of each source, providing a sufficent hydrostatic pressure to allow local CNM condensation. (abridged)

Robert Braun; Butler Burton

1999-12-20

363

High Resolution Continuous Flow Analysis System for Polar Ice Cores  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

364

High temporal resolution ocular aberrometry with pupil tracking  

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

365

High resolution near-infrared deep fields with MCAO  

NASA Astrophysics Data System (ADS)

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.

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

2014-07-01

366

Spatial-temperature high resolution map for early cancer diagnosis  

NASA Astrophysics Data System (ADS)

Heat is one of the most important parameters of living beings. Skin temperature is not the same on the entire body and so, a thermal signature can be got. Infrared map on serial imaging can constitute an early sign of an abnormality. Thermography detects changes in tissue that appear before and accompany many diseases including cancer. As this map has a better resolution an early cancer diagnosis can be done. The temperature of neoplasic tissue is different up to 1.5 C than that of the healthy tissue as a result of the specific metabolic rate. The infrared camera images show very quickly the heat transferred by radiation. A lot of factors disturb the temperature conversion to pixel intensity. A sensitive temperature sensor with a 10 Mpixels video camera, showing its spatial position, and a computer fusion program were used for the map with high spatial-temperature resolution. A couple of minutes are necessary to get a high resolution map. The asymmetry and borders were the main parameters analyzed. The right cancer diagnosis was for about 78.4% of patients with thyroid cancer, and more than 89.6% from patients with breast cancer. In the near future, the medical prognosis will be improved by fractal analysis.

Gavriloaia, Gheorghe V.; Hurduc, Anca; Ghimigean, Ana-Maria; Fumarel, Radu

2009-02-01

367

High-resolution multimodal clinical multiphoton tomography of skin  

NASA Astrophysics Data System (ADS)

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.

Knig, Karsten

2011-03-01

368

High resolution optical surface testing using transport of intensity equation  

NASA Astrophysics Data System (ADS)

Phase distribution may be determined by measuring only the intensity distributions along the optical axis via the Transport of Intensity Equation (TIE). TIE has been a viable alternative to interferometry techniques for experimental conditions where those techniques perform poorly. These conditions are either because of the requirement one applies on the spatial and temporal coherence of the optical source or because of sensitivity and resolution issues. Optical testing is crucial in applications using manufactured optical elements. In this paper, we developed a method and experimental realizations capable to use both Shake-Hartman wavefront sensing (SHWS) and TIE method for testing transparent and reflective optical surfaces. The integration of TIE and SHWS has the advantage for obtaining high spatial resolution and wide dynamic range which cannot be obtained using only one of those methods. We showed that the retrieved phase profile and quantified surface variations of unknown samples from both methods are in very good agreement with each other.

Soltani, Peyman; Moradi, Ali-Reza; Darudi, Ahmad; Shomali, Ramin

2013-11-01

369

Towards high-resolution ptychographic x-ray diffraction microscopy  

SciTech Connect

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

Takahashi, Yukio; Suzuki, Akihiro; Yamauchi, Kazuto [Graduate School of Engineering, Osaka University, 2-1 Yamada oka, Suita, Osaka 565-0871 (Japan); Zettsu, Nobuyuki [Department of Materials, Physics and Energy Engineering, Graduate School of Engineering, Nagoya University, Furocho, Chikusa-ku, Nagoya 4648603 (Japan); Kohmura, Yoshiki; Ishikawa, Tetsuya [RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo, Hyogo 679-5148 (Japan); Senba, Yasunori; Ohashi, Haruhiko [Japan Synchrotron Radiation Research Institute, SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo, Hyogo 679-5198 (Japan)

2011-06-01

370

Prospects for vibrational-mode EELS with high spatial resolution.  

PubMed

Taking advantage of previous measurements by Geiger and co-workers, we discuss the possibilities and problems of measuring vibrational modes of energy loss in a transmission electron microscope fitted with a monochromator and a high-resolution energy-loss spectrometer. The tail of the zero-loss peak is seen to be a major limitation, rather than its full-width at half-maximum. Because of the low oscillator strengths and small cross-sections involved, radiation damage will limit the spatial resolution if this technique is applied to organic specimens. Delocalization of the inelastic scattering may also be a limitation, if a dipole description of the scattering process is valid. PMID:24548332

Egerton, R F

2014-06-01

371

Fabricating High Resolution Mirrors for Hand X-Ray Astronomy  

NASA Technical Reports Server (NTRS)

We describe the fabrication process for producing high-resolution conical mirrors for hard x-ray astronomy. When flown aboard stratospheric balloons, these high-resolution reflective mirrors focus hard x-rays (10-70 keV) emitted from cosmic sources such as supernovae, neutron stars, and quasars onto imaging focal plane detectors. Focused hard x-ray images allow scientists to determine the elemental compositions, temperatures, magnetic fields, velocities, and gravitational fields of these celestial bodies. The fabrication process involves generating super-polished mandrels, mandrel metrology, mirror shell nickel electroforming, and mirror testing. Each mandrel is a cylinder consisting of two conical segments; each segment is approximately 305-mm long. Through precision grinding these mandrels before super polishing, we have achieved 30 arc seconds, half power diameter replicated mirrors. During a May 2001 high atmosphere balloon flight, these mirrors focused high energy x-rays from three different celestial sources. However, we seek to improve the angular resolutions of future mirror shells by a factor of two. To achieve this goal, we have begun single point diamond turning the mandrels before super polishing. This has allowed greater precision tolerances on mandrel surface roughness and axial figure errors before super polishing. Surface roughnesses before polishing have been reduced from approximately 60 nm to approximately 15 nm. The peak to valley axial figure profile errors have been reduced from approximately 1.0 micrometers to approximately 0.4 micrometers. We are currently in Phase 2 of the HERO (high energy replicated optics) program which entails the production of sixteen 6-m-focal-length mirror modules, each containing a nested array of 15 mirror shells of diameters ranging from 50-mm to 94-mm. This flight is slated for the fall of 2003.

Speegle, Chet O.; Ramsey, Brian D.; Engelhaupt, Darell; Six, N. Frank (Technical Monitor)

2001-01-01

372

High-resolution mapping of motor vehicle carbon dioxide emissions  

NASA Astrophysics Data System (ADS)

fuel-based inventory for vehicle emissions is presented for carbon dioxide (CO2) and mapped at various spatial resolutions (10 km, 4 km, 1 km, and 500 m) using fuel sales and traffic count data. The mapping is done separately for gasoline-powered vehicles and heavy-duty diesel trucks. Emission estimates from this study are compared with the Emissions Database for Global Atmospheric Research (EDGAR) and VULCAN. All three inventories agree at the national level within 5%. EDGAR uses road density as a surrogate to apportion vehicle emissions, which leads to 20-80% overestimates of on-road CO2 emissions in the largest U.S. cities. High-resolution emission maps are presented for Los Angeles, New York City, San Francisco-San Jose, Houston, and Dallas-Fort Worth. Sharp emission gradients that exist near major highways are not apparent when emissions are mapped at 10 km resolution. High CO2 emission fluxes over highways become apparent at grid resolutions of 1 km and finer. Temporal variations in vehicle emissions are characterized using extensive day- and time-specific traffic count data and are described over diurnal, day of week, and seasonal time scales. Clear differences are observed when comparing light- and heavy-duty vehicle traffic patterns and comparing urban and rural areas. Decadal emission trends were analyzed from 2000 to 2007 when traffic volumes were increasing and a more recent period (2007-2010) when traffic volumes declined due to recession. We found large nonuniform changes in on-road CO2 emissions over a period of ~5 years, highlighting the importance of timely updates to motor vehicle emission inventories.

McDonald, Brian C.; McBride, Zoe C.; Martin, Elliot W.; Harley, Robert A.

2014-05-01

373

Digital Holography for Fast High-Spatial-Resolution Density Measurements  

NASA Astrophysics Data System (ADS)

A digital holography demonstration system has been used on the ORNL Disruption Mitigation Test Stand to make extremely high spatial resolution (less than one mm) 2-D density measurements. Although holographic interferometry has long been used as a density diagnostic, this is the first application of digital holography (no plates, no darkroom, no chemicals, no waiting) to high-resolution spatial measurements of density. In the present experiments a CO2 laser and 320 x 256 pixel (82,000 pixels) infrared-camera based digital holography system has measured the expansion plume from a fast-valve high-pressure gas injection system similar to the disruption mitigation system presently being tested on DIII-D. The present system is capable of exposures as short as 20 microseconds at 30 frames-per-second (FPS). The experimental design and data from the ORNL Disruption Mitigation Test Stand experiments will be presented, along with discussion of the design and specifications for a second generation system with pulse exposures as short as one microsecond and frame rates as high as 10,000 FPS, proposed for use as a density and fluctuation diagnostic on the LTX experiment at PPPL.

Thomas, C. E., Jr.; Baylor, L. R.; Combs, S. K.; Meitner, S. J.; Rasmussen, D. A.

2008-11-01

374

A high-resolution bedrock map for the Antarctic Peninsula  

NASA Astrophysics Data System (ADS)

Glaciers on the Antarctic Peninsula show a high sensitivity to changed climatic and oceanic conditions and are expected to significantly contribute to sea-level rise over the next decades. So far, the best bedrock data set for the region is the recently released Bedmap2 providing ice thickness on a 1 km grid. Whereas for large-scale ice sheet modelling the spatial resolution provided by Bedmap2 is sufficient, detailed considerations of surface mass balance, ice flow and grounding line dynamics of Antarctic Peninsula glaciers necessitate the application of models that are able to cope with the high spatial variability of the governing processes. For ice flow models used to predict future glacier response to climate change and/or ice shelf break-off, a high-resolution bedrock topography is required as an essential boundary condition. Here, we derive a complete bedrock data set for the Antarctic Peninsula north of 70S on a 100 m grid. We further develop an established method to invert surface topography using simple ice dynamic modelling to obtain distributed ice thickness. Our approach makes use of a high-resolution digital elevation model, catchment boundaries for all glaciers of the Peninsula, and RACMO-based surface mass balance data. The results are constrained with all available thickness measurements from Operation IceBridge and gridded ice flow speeds for the entire study region. The new data set resolves the rugged subglacial topography in great detail, indicates deeply incised troughs with thicknesses of up to 1500 m, and shows that 32% of the ice volume is grounded below sea level. The Antarctic Peninsula has the potential to raise global sea level by 71.95.8 mm. In comparison to Bedmap2 we find a significantly higher mean ice thickness (+47%) which is attributed to the approach used to calculate thickness in regions not covered with direct measurements. Our high-resolution bedrock data set offers new possibilities for studying the contribution of the Antarctic Peninsula to sea-level rise with state-of-the-art glacier models.

Huss, Matthias; Farinotti, Daniel

2014-05-01

375

CSpace high-resolution volumetric 3D display  

NASA Astrophysics Data System (ADS)

We are currently in the process of developing a static-volume 3D display, CSpace display, that has the capability to produce images of much larger size than any other static-volume display currently under development, with up to nearly 800 million voxel resolution. A key component in achieving the size and resolution of the display is the optical system that transfers the pixel data from a standard DMD projection unit to the voxel size required by the display with high contrast and minimal distortion. The current optical system is capable of such performance for only small image sizes, and thus new designs of the optical system must be developed. We report here on the design and testing of a new optical projection system with the intent of achieving performance close to that of a telecentric lens. Theoretical analysis with Zemax allowed selection of appropriate lens size, spacing, and focal length, and identified the need for tilting the assembly to produce the desired beam properties. Experimental analysis using the CSpace prototype showed that the improved beam parameters allowed for higher resolution and brighter images than those previously achieved, though their remains room for further improvement of the design. Heating of the DMD and its housing components were also addressed to minimize heating effects on the optical system. A combination of a thermo-electric cooler and a small fan produced sufficient cooling to stabilize the temperature of the system to acceptable levels.

Refai, Hakki H.; Melnik, George; Willner, Mark

2013-05-01

376

High-resolution and broadband all-fiber spectrometers  

E-print Network

The development of optical fibers has revolutionized telecommunications by enabling long-distance broad-band transmission with minimal loss. In turn, the ubiquity of high-quality low-cost fibers enabled a number of additional applications, including fiber sensors, fiber lasers, and imaging fiber bundles. Recently, we showed that a mutlimode optical fiber can also function as a spectrometer by measuring the wavelength-dependent speckle pattern formed by interference between the guided modes. Here, we reach a record resolution of 1 pm at wavelength 1500 nm using a 100 meter long multimode fiber, outperforming the state-of-the-art grating spectrometers. we also achieved broad-band operation with a 4 cm long fiber, covering 400 nm - 750 nm with 1 nm resolution. The fiber spectrometer, consisting of the fiber which can be coiled to a small volume and a monochrome camera that records the speckle pattern, is compact, lightweight, and low cost while providing ultrahigh resolution, broad bandwidth and low loss.

Redding, Brandon; Seifert, Martin; Cao, Hui

2014-01-01

377

Extraction and labeling high-resolution images from PDF documents  

NASA Astrophysics Data System (ADS)

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

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

2013-12-01

378

Computational analysis of high resolution unsteady airloads for rotor aeroacoustics  

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

379

Resolution of a High Performance Cavity Beam Positron Monitor System  

SciTech Connect

International Linear Collider (ILC) interaction region beam sizes and component position stability requirements will be as small as a few nanometers. It is important to the ILC design effort to demonstrate that these tolerances can be achieved--ideally using beam-based stability measurements. It has been estimated that RF cavity beam position monitors (BPMs) could provide position measurement resolutions of less than one nanometer and could form the basis of the desired beam-based stability measurement. We have developed a high resolution RF cavity BPM system. A triplet of these BPMs has been installed in the extraction line of the KEK Accelerator Test Facility (ATF) for testing with its ultra-low emittance beam. A metrology system for the three BPMs was recently installed. This system employed optical encoders to measure each BPM's position and orientation relative to a zero-coefficient of thermal expansion carbon fiber frame and has demonstrated that the three BPMs behave as a rigid-body to less than 5 nm. To date, we have demonstrated a BPM resolution of less than 20 nm over a dynamic range of +/- 20 microns.

Walston, S.; Chung, C.; Fitsos, P.; Gronberg, J.; /LLNL, Livermore; Ross, M.; /Fermilab; Khainovski, O.; Kolomensky, Y.; Loscutoff, P.; /LBL, Berkeley; Slater, M.; Thomson, M.; Ward, D.; /Cambridge U.; Boogert, S.; /Royal Holloway, U. of London; Vogel, V.; /DESY; Meller, R.; /Cornell U., LNS; Lyapin, A.; Malton, S.; Miller, D.; /University Coll. London; Frisch, J.; Hinton, S.; May, J.; McCormick, D.; /SLAC /Caltech /KEK, Tsukuba

2007-07-06

380

Resolution of a High Performance Cavity Beam Position Monitor System  

SciTech Connect

International Linear Collider (ILC) interaction region beam sizes and component position stability requirements will be as small as a few nanometers. It is important to the ILC design effort to demonstrate that these tolerances can be achieved - ideally using beam-based stability measurements. It has been estimated that RF cavity beam position monitors (BPMs) could provide position measurement resolutions of less than one nanometer and could form the basis of the desired beam-based stability measurement. We have developed a high resolution RF cavity BPM system. A triplet of these BPMs has been installed in the extraction line of the KEK Accelerator Test Facility (ATF) for testing with its ultra-low emittance beam. A metrology system for the three BPMs was recently installed. This system employed optical encoders to measure each BPM's position and orientation relative to a zero-coefficient of thermal expansion carbon fiber frame and has demonstrated that the three BPMs behave as a rigid-body to less than 5 nm. To date, we have demonstrated a BPM resolution of less than 20 nm over a dynamic range of +/- 20 microns.

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

2005-09-12

381

High-resolution retinal imaging with micro adaptive optics system.  

PubMed

Based on the dynamic characteristics of human eye aberration, a microadaptive optics retina imaging system set is established for real-time wavefront measurement and correction. This paper analyzes the working principles of a 127-unit Hartmann-Shack wavefront sensor and a 37-channel micromachine membrane deformable mirror adopted in the system. The proposed system achieves wavefront reconstruction through the adaptive centroid detection method and the mode reconstruction algorithm of Zernike polynomials, so that human eye aberration can be measured accurately. Meanwhile, according to the adaptive optics aberration correction control model, a closed-loop iterative aberration correction algorithm based on Smith control is presented to realize efficient and real-time correction of human eye aberration with different characteristics, and characteristics of the time domain of the system are also optimized. According to the experiment results tested on a USAF 1951 standard resolution target and a living human retina (subject ZHY), the resolution of the system can reach 3.6?LP/mm, and the human eye wavefront aberration of 0.728? (?=785?nm) can be corrected to 0.081? in root mean square (RMS) so as to achieve the diffraction limit (Strehl ratio is 0.866), then high-resolution retina images are obtained. PMID:21833112

Niu, Saisai; Shen, Jianxin; Liang, Chun; Zhang, Yunhai; Li, Bangming

2011-08-01

382

A High Resolution Radar Survey of the Lunar Near Side  

NASA Astrophysics Data System (ADS)

Since 2005 we have been using the Arecibo 13 cm transmitting system and the 100 m Green Bank Telescope (GBT) in a bi-static radar configuration for multi-polarization imaging of the lunar surface at resolutions as fine as 20 m. A circularly polarized wave is transmitted and the echo received in both senses of received circular polarization, allowing imaging in the full Stokes polarization parameters of the reflected signal. The initial objective was the South Pole region, with emphasis on high-resolution images of possible landing sites and polarimetric analysis of putative ice deposits (D. Campbell et al, 2006 Nature, 443, 835). A byproduct of this work was a method for clearly identifying secondary craters from Tycho via their circular polarization ratio signature (K. Wells et al, 2006, DPS abst). Subsequent observations have concentrated on studies of pyroclastic deposits including potentially resource-rich areas such as the Aristarchus plateau, where the radar's ability to probe the sub-surface has allowed the subsurface rock distribution to be investigated (B. Campbell et al, 2008, Geology, 36, 135; Carter et al, 2007 LPSC Conf. 38, Houston, Texas). We have begun a systematic mapping program that will image most of the near side of the Moon in the full Stokes parameters. The initial product is a large area image of the south-polar region at 20 m resolution, with one look (see http://arecibo.tc.cornell.edu/lunarimages/default.aspx). To reduce the required observation time to an acceptable level, subsequent images will be at 80 m resolution, four looks. The results will be made available through the PDS. We acknowledge the NASA Planetary Astronomy program for partial support of this work and NAIC and NRAO for making Arecibo and the GBT available for the observations.

Campbell, Donald B.; Campbell, B. A.; Carter, L. M.; Ghent, R. R.; Nolan, M. C.; Wells, K. S.

2008-09-01

383

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

NASA Technical Reports Server (NTRS)

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

Prechtl, Eric F.; Sedwick, Raymond J.

2010-01-01

384

Sensitivity of ozone to model grid resolutionI. Application of high-resolution regional acid deposition model  

Microsoft Academic Search

This paper examines the sensitivity of ozone (O3) predictions to grid resolution in Eulerian grid models. A high-resolution version of the regional acid deposition model (HR-RADM) was developed and applied to simulate O3 formation at different grid resolutions. Horizontal grid-cell sizes of 20, 40, and 80 km were selected for this sensitivity study. Individual meteorological and chemical processes that contribute

Daewon Byun; Jonathan E. Pleim

1995-01-01

385

Resolution and noise properties of the Goddard High-Resolution Spectrograph  

NASA Technical Reports Server (NTRS)

The Goddard High-Resolution Spectrograph (GHRS) observation characteristics and data analysis procedures, including deconvolution, are discussed. Particular attention is given to the detection of weak absorption lines in low-signal-to-noise observations. It is found that observations with the GHRS large aperture provide greater sensitivity for the detection of weak, isolated spectral features than does the small aperture for equal observing times. The noise characteristics are well represented by a Poisson distribution at low signal-to-noise characteristics. It is proposed that GHRS observations should be routinely structured with the use of comb-addition, quarter-substepping, FP-SPLITS, and multiple repeats to enable the proper discrimination against noise events capable of mimicking spectral features.

Gilliland, Ronald L.; Morris, Simon L.; Weymann, Ray J.; Ebbets, Dennis C.; Lindler, Don J.

1992-01-01

386

A new method of high resolution, quantitative phase scanning microscopy  

NASA Astrophysics Data System (ADS)

Coherent Diffractive Imaging (CDI) is a method of lensless imaging that reconstructs a target object from recordings of the diffraction pattern it generates when illuminated by a coherent source. A new method of scanning CDI, 'Ptychography,' was introduced recently and has been successfully demonstrated as a method of lensless microscopy at optical and x-ray wavelengths. Here we show how it can be applied to visible light microscopy to produce high resolution quantitative phase images of low-contrast objects, such as unstained cells.

Maiden, A. M.; Rodenburg, J. M.; Humphry, M. J.

2010-06-01

387

High-resolution AMLCD for the electronic library system  

NASA Astrophysics Data System (ADS)

The Electronic Library System (ELS), is a proposed data resource for the cockpit which can provide the aircrew with a vast array of technical information on their aircraft and flight plan. This information includes, but is not limited to, approach plates, Jeppeson Charts, and aircraft technical manuals. Most of these data are appropriate for digitization at high resolution (300 spi). Xerox Corporation has developed a flat panel active matrix liquid crystal display, AMLCD, that is an excellent match to the ELS, due to its innovative and aggressive design.

Martin, Russel A.; Middo, Kathy; Turner, William D.; Lewis, Alan; Thompson, Malcolm J.; Silverstein, Louis D.

1994-06-01

388

Design of a High Resolution Hexapod Positioning Mechanism  

NASA Technical Reports Server (NTRS)

This paper describes the development of a high resolution, six-degree of freedom positioning mechanism. This mechanism, based on the Stewart platform concept, was designed for use with the Developmental Comparative Active Optics Telescope Testbed (DCATT), a ground-based technology testbed for the Next Generation Space Telescope (NGST). The mechanism provides active control to the DCATT telescope's segmented primary mirror. Emphasis is on design decisions and technical challenges. Significant issues include undesirable motion properties of PZT-inchworm actuators, testing difficulties, dimensional stability and use of advanced composite materials. Supporting test data from prototype mechanisms is presented.

Britt, Jamie; Brodeur, Stephen J. (Technical Monitor)

2001-01-01

389

Design of a High Resolution Hexapod Positioning Mechanism  

NASA Technical Reports Server (NTRS)

This paper describes the development of a high resolution, six-degree of freedom positioning mechanism. This mechanism, based on the Stewart platform concept, was designed for use with the Developmental Comparative Active Optics Telescope Testbed (DCATT), a ground-based technology testbed for the Next Generation Space Telescope (NGST). The mechanism provides active control to the DCATT telescope's segmented primary mirror. Emphasis is on design decisions and technical challenges. Significant issues include undesirable motion properties of PZT-inchworm actuators, testing difficulties, dimensional stability, and use of advanced composite materials. Supporting test data from prototype mechanisms is presented.

Britt, Jamie

2001-01-01

390

Coherent and polarisation properties of high resolution radar sea echo  

NASA Astrophysics Data System (ADS)

This paper presents the results of a series of investigations into the characteristics of high range resolution Doppler spectra resulting from radar scattering by a perturbed sea surface. In particular, it is demonstrated how the non-Gaussian characteristics of noncoherently detected clutter manifest themselves in the spectral domain and how these characteristics must be thoroughly understood in order to optimize any detection processing. In addition, the dependence of the scattering characteristics on transmitter and receiver polarization, sea state, and grazing angle have been measured in order to investigate the mechanisms responsible for the experimental observations.

Baker, C. J.

391

High-resolution satellite imagery for mesoscale meteorological studies  

NASA Technical Reports Server (NTRS)

In this article high-resolution satellite imagery from a variety of meteorological and environmental satellites is compared. Digital datasets from Geostationary Operational Environmental Satellite (GOES), National Oceanic and Atmospheric Administration (NOAA), Defense Meteorological Satellite Program (DMSP), Landsat, and Satellite Pour l'Observation de la Terre (SPOT) satellites were archived as part of the 1990 Hawaiian Rainband Project (HaRP) and form the basis of the comparisons. During HaRP, GOES geostationary satellite coverage was marginal, so the main emphasis is on the polar-orbiting satellites.

Johnson, David B.; Flament, Pierre; Bernstein, Robert L.

1994-01-01

392

High-resolution ultrasound of the extrinsic carpal ligaments?  

PubMed Central

Thanks to its intrinsic high spatial resolution, ultrasound is an ideal imaging modality for examining very thin, superficial structures, and this makes it very helpful in the evaluation of extrinsic carpal ligaments. These structures, which arise from the radius and ulna and insert on the carpal bones, are extremely important for wrist stability. Previous studies have assessed the use of ultrasound to study the extrinsic carpal ligaments in cadavers, healthy asymptomatic subjects, and patients with rheumatoid arthritis. In the present report, we review the normal anatomy, biomechanics, and ultrasound appearance of these ligaments. PMID:23730393

Orlandi, D.; Fabbro, E.; Ferrero, G.; Martini, C.; Lacelli, F.; Serafini, G.; Silvestri, E.; Sconfienza, L.M.

2012-01-01

393

NASA Langley Airborne High Spectral Resolution Lidar Instrument Description  

NASA Technical Reports Server (NTRS)

NASA Langley Research Center (LaRC) recently developed the LaRC Airborne High Spectral Resolution Lidar (HSRL) to make measurements of aerosol and cloud distribution and optical properties. The Airborne HSRL has undergone as series of test flights and was successfully deployed on the Megacity Initiative: Local and Global Research Observations (MILAGRO) field mission in March 2006 (see Hair et al. in these proceedings). This paper provides an overview of the design of the Airborne HSRL and descriptions of some key subsystems unique to this instrument.

Harper, David B.; Cook, Anthony; Hostetler, Chris; Hair, John W.; Mack, Terry L.

2006-01-01

394

POWERWALL: International Workshop on Interactive, Ultra-High-Resolution Displays  

SciTech Connect

Ultra-high-resolution (Powerwall) displays are becoming increasingly popular due to the ever decreasing cost of hardware. As a result they are appearing more frequently in research institutes, and making the jump out of the lab and into industry. Due to the amount of work in this research area that has been published in CHI over the last few years, we felt that this confernece would be the ideal host for the first opportunity for both academics and practitioners in this field to get together.

Rooney, Chris; Endert, Alexander; Fekete, Jean-Daniel; Hornbaek, Kasper; North, Chris

2013-04-27

395

On the small vessel detection in high resolution retinal images.  

PubMed

In this paper, we proposed a new scheme for detection of small blood vessels in retinal images. A novel filter called Gabor Variance Filter and a modified histogram equalization technique are developed to enhance the contrast between vessels and background. Vessel segmentation is then performed on the enhanced map using thresholding and branch pruning based on the vessel structures. The experiments on high resolution images showed the desirable results with performance of 84.75% true positive rate and 0.15% false positive rate. PMID:17282919

Zhang, Ming; Wu, Di; Liu, Jyh-Charn

2005-01-01

396

Applied high resolution geophysical methods: Offshore geoengineering hazards  

SciTech Connect

This book is an examination of the purpose, methodology, equipment, and data interpretation of high-resolution geophysical methods, which are used to assess geological and manmade engineering hazards at offshore construction locations. It is a state-of-the-art review. Contents: 1. Introduction. 2. Maring geophysics, an overview. 3. Marine geotechnique, an overview. 4. Echo sounders. 5. Side scan sonar. 6. Subbottom profilers. 7. Seismic sources. 8. Single-channel seismic reflection systems. 9. Multifold acquisition and digital processing. 10. Marine magnetometers. 11. Marine geoengineering hazards. 12. Survey organization, navigation, and future developments. Appendix. Glossary. References. Index.

Trabant, P.K.

1984-01-01

397

High-resolution frequency domain second harmonic optical coherence tomography  

NASA Astrophysics Data System (ADS)

We used continuum generated in an 8.5 cm long fiber by a femtosecond Yb fiber laser to improve threefold the axial resolution of frequency domain SH-OCT to 12?m. The acquisition time was shortened by more than two orders of magnitude compared to time domain SH-OCT. The system was applied to image biological tissue of fish scales, pig leg tendon and rabbit eye sclera. Highly organized collagen fibrils can be visualized in the recorded images. Polarization dependence on second harmonic has been used to obtain polarization resolved images.

Su, Jianping; Tomov, I. V.; Jiang, Yi; Chen, Zhongping

2007-02-01

398

A High Resolution Microprobe Study of EETA79001 Lithology C  

NASA Technical Reports Server (NTRS)

Antarctic meteorite EETA79001 has received substantial attention for possibly containing a component of Martian soil in its impact glass (Lithology C) [1]. The composition of Martian soil can illuminate near-surface processes such as impact gardening [2] and hydrothermal and volcanic activity [3,4]. Impact melts in meteorites represent our most direct samples of Martian regolith. We present the initial findings from a high-resolution electron microprobe study of Lithology C from Martian meteorite EETA79001. As this study develops we aim to extract details of a potential soil composition and to examine Martian surface processes using elemental ratios and correlations.

Schrader, Christian M.; Cohen, B. A.; Donovan, J. J.; Vicenzi, E. P.

2010-01-01

399

High-resolution MR neurography of diffuse peripheral nerve lesions.  

PubMed

High-resolution MR imaging of peripheral nerves is becoming more common and practical with the increasing availability of 3T magnets. There are multiple reports of MR imaging of peripheral nerves in compression and entrapment neuropathies. However, there is a relative paucity of literature on MRN appearance of diffuse peripheral nerve lesions. We attempted to highlight the salient imaging features of myriad diffuse peripheral nerve disorders and imaging techniques for MRN. Using clinical and pathologically proved relevant examples, we present the MRN appearance of various types of diffuse peripheral nerve lesions, such as traumatic, inflammatory, infectious, hereditary, radiation-induced, neoplastic, and tumor variants. PMID:20966057

Thawait, S K; Chaudhry, V; Thawait, G K; Wang, K C; Belzberg, A; Carrino, J A; Chhabra, A

2011-09-01

400

High-resolution magnetic resonance neurography in upper extremity neuropathy.  

PubMed

The most common sites of nerve entrapment are in the upper extremity, commonly diagnosed based on clinical findings and electrophysiologic studies. Cross-sectional imaging modalities, such as ultrasonography and magnetic resonance (MR) imaging, have been used to enhance diagnostic accuracy and provide anatomic mapping of abnormalities. MR neurography offers multiplanar high-resolution imaging of upper extremity nerves as well as adjacent soft tissues, and provides an objective assessment of the neuromuscular anatomy and related abnormalities. This article reviews the normal 3-T MR neurographic appearance of the upper extremity nerves, and abnormal findings related to injury, entrapment, and other pathologic conditions. PMID:24210316

Chalian, Majid; Behzadi, Ashkan Heshmatzadeh; Williams, Eric H; Shores, Jaimie T; Chhabra, Avneesh

2014-02-01

401

High-resolution radio observations of X-ray binaries  

E-print Network

I present an overview of important results obtained using high-resolution very long baseline interferometry (VLBI) observations of X-ray binary systems. These results derive from both astrometric observations and resolved imaging of sources, from black holes to neutron star and even white dwarf systems. I outline a number of upcoming developments in instrumentation, both new facilities and ongoing upgrades to existing VLBI instruments, and I conclude by identifying a number of important areas of investigation where VLBI will be crucial in advancing our understanding of X-ray binaries.

James Miller-Jones

2008-09-15

402

Breakdown coefficients of high-resolution temporal rainfall  

NASA Astrophysics Data System (ADS)

Eleuch et al. [2010, SERRA 24(5), 559-565] have shown that the differences in spatial rainfall intensities scale with distance in a manner that is compatible with fractal scale invariance. On the same lines, the present work is dedicated to the study of the scale behaviour of joint statistics in high-resolution temporal rainfall. The position of the most extreme breakdown coefficients in the decomposition of temporal rainfall has been proven to determine the structure of autocorrelation in the time series of intensities [Carsteanu et al., 1999, JGR 104(D24), 31611-622], reason for which we are focusing on presenting our results in this framework.

Martnez-Novelo, Ricardo; Carsteanu, Alin Andrei

2013-04-01

403

Clickstream data yields high-resolution maps of science  

SciTech Connect

Intricate maps of science have been created from citation data to visualize the structure of scientific activity. However, most scientific publications are now accessed online. Scholarly web portals record detailed log data at a scale that exceeds the number of all existing citations combined. Such log data is recorded immediately upon publication and keeps track of the sequences of user requests (clickstreams) that are issued by a variety of users across many different domains. Given these advantagees of log datasets over citation data, we investigate whether they can produce high-resolution, more current maps of science.

Bollen, Johan [Los Alamos National Laboratory; Van De Sompel, Herbert [Los Alamos National Laboratory; Hagberg, Aric [Los Alamos National Laboratory; Bettencourt, Luis [Los Alamos National Laboratory; Chute, Ryan [Los Alamos National Laboratory; Rodriguez, Marko A [Los Alamos National Laboratory; Balakireva, Lyudmila [Los Alamos National Laboratory

2009-01-01

404

An Ultra High Resolution 7-Inch Round Monochrome Crt  

NASA Astrophysics Data System (ADS)

This report describes the general theory and design of an ultra high resolution, film recorder CRT which was developed at Tektronix, Inc. The electron gun utilizes a unique pre-focusing scheme to significantly reduce aberrations in the final focusing lens, thus yielding a spot of less than .001" (1 mil) at the half power point (50%) with a beam current of 10 ?A. The non-aluminized, fine particle phosphor screen was developed to minimize spot growth and maximize luminance output, while meeting stringent target defect specifications.

Jaqua, Evan; Kulkarni, Sudakar

1987-04-01

405

High-resolution continuum observations of the Sun  

NASA Technical Reports Server (NTRS)

The aim of the PFI or photometric filtergraph instrument is to observe the Sun in the continuum with as high resolution as possible and utilizing the widest range of wavelengths. Because of financial and political problems the CCD was eliminated so that the highest photometric accuracy is only obtainable by comparison with the CFS images. Presently there is a limitation to wavelengths above 2200 A due to the lack of sensitivity of untreated film below 2200 A. Therefore the experiment at present consists of a film camera with 1000 feet of film and 12 filters. The PFI experiments are outlined using only two cameras. Some further problems of the experiment are addressed.

Zirin, Harold

1987-01-01

406

New High Spatio-Thermal Resolution Liquid Crystal Sheet  

NASA Astrophysics Data System (ADS)

Liquid crystal is used with full success, mainly in breast cancer detection, skin disease, scrotal disease, and veterinarian experimentation, in addition to industrial quality control (mechanical and electronic circuitry testing). The importance of the results of these uses demonstrates the necessity of improving the spatiothermal resolution and isothermic possibilities. This work introduces new manufacturing processes of encapsulated liquid crystal mixtures selected for specific characteristics. The coating of the liquid crystal-Is explained, the accuracy measurement and testing are exposed, with all the new applications possible due to the high quality of the product. Comparison of special cases of old sheets and new ones are detailed. New potential uses and developments are discussed.

Liegeois, , C.; Fontaine, J.; Quenneville, Y.

1980-05-01

407

A high resolution pneumatic stepping actuator for harsh reactor environments  

NASA Astrophysics Data System (ADS)

A reactivity control actuator for a high-power density nuclear propulsion reactor must be installed in close proximity to the reactor core. The energy input from radiation to the actuator structure could exceed hundreds of W/cc unless low-cross section, low-absorptivity materials are chosen. Also, for post-test handling and subsequent storage, materials should not be used that are activated into long half-life isotopes. Pneumatic actuators can be constructed from various reactor-compatible materials, but conventional pneumatic piston actuators generally lack the stiffness required for high resolution reactivity control unless electrical position sensors and compensated electronic control systems are used. To overcome these limitations, a pneumatic actuator is under development that positions an output shaft in response to a series of pneumatic pulses, comprising a pneumatic analog of an electrical stepping motor. The pneumatic pulses are generated remotely, beyond the strong radiation environment, and transmitted to the actuator through tubing. The mechanically simple actuator uses a nutating gear harmonic drive to convert motion of small pistons directly to high-resolution angular motion of the output shaft. The digital nature of this actuator is suitable for various reactor control algorithms but is especially compatible with the three bean salad algorithm discussed by Ball et al. (1991).

Tippetts, Thomas B.; Evans, Paul S.; Riffle, George K.

1993-01-01

408

A high resolution pneumatic stepping actuator for harsh reactor environments  

SciTech Connect

A reactivity control actuator for a high-power density nuclear propulsion reactor must be installed in close proximity to the reactor core. The energy input from radiation to the actuator structure could exceed hundreds of W/cc unless low-cross section, low-absorptivity materials are chosen. Also, for post-test handling and subsequent storage, materials should not be used that are activated into long half-life isotopes. Pneumatic actuators can be constructed from various reactor-compatible materials, but conventional pneumatic piston actuators generally lack the stiffness required for high resolution reactivity control unless electrical position sensors and compensated electronic control systems are used. To overcome these limitations, a pneumatic actuator is under development that positions an output shaft in response to a series of pneumatic pulses, comprising a pneumatic analog of an electrical stepping motor. The pneumatic pulses are generated remotely, beyond the strong radiation environment, and transmitted to the actuator through tubing. The mechanically simple actuator uses a nutating gear harmonic drive to convert motion of small pistons directly to high-resolution angular motion of the output shaft. The digital nature of this actuator is suitable for various reactor control algorithms but is especially compatible with the three bean salad algorithm discussed by Ball [ital et] [ital al]. (1991).

Tippetts, T.B.; Evans, P.S.; Riffle, G.K. (Allied-Signal Aerospace Company, Garrett Fluid Systems Division, 1300 W. Warner Rd., P.O. Box 22200, Tempe, Arizona 85282 (United States))

1993-01-20

409

High resolution micro ultrasonic machining for trimming 3D microstructures  

NASA Astrophysics Data System (ADS)

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

Viswanath, Anupam; Li, Tao; Gianchandani, Yogesh

2014-06-01

410

A high resolution terahertz spectrometer for chemical detection  

NASA Astrophysics Data System (ADS)

Goodrich has been developing a high resolution, broad band spectrometer that operates in the Terahertz (THz) region of the spectrum with the intent of performing chemical detection. THz spectroscopy exploits rotational resonances for detection of gas phase compounds. High resolution THz spectroscopy can improve detection and identification through increased probability of detection and reduced false alarms. The Goodrich THz spectrometer is based upon CW photomixer technology in a heterodyne configuration. The current Goodrich design offers continuous tunability across a 0.1 THz to 1.2 THz frequency range. One of the unique aspects of the Goodrich spectrometer is laser system control that has demonstrated difference frequency line widths on the order of 1.5 MHz with stability measured over long time scales. Absolute frequency accuracy is of the order of 4 MHz. The spectrometer design enables high THz energy densities with narrow line widths tunable over a broad spectrum. The system has demonstrated SNR better than a cryogenically cooled hot electron bolometer. This capability allows the Goodrich system to accurately determine absorption signatures of multiple chemicals with exceptional performance. Goodrich has completed initial system testing and verified performance. Initial tests were completed to determine SNR of the heterodyne photomixer transceiver. System performance was also verified for laser line width, stability, and repeatability. The spectrometer was tested against various toxic industrial chemicals. Preliminary data for HCN, HCl, NH 3, and SO II is presented.

Majewski, Alexander; Abreu, Rene; Wraback, Michael

2007-04-01

411

Characterisation of Nanoparticle Structure by High Resolution Electron Microscopy  

NASA Astrophysics Data System (ADS)

Whilst the use of microscopic techniques to determine the size distributions of nanoparticle samples is now well established, their characterisation challenges extend well beyond this. Here it is shown how high resolution electron microscopy can help meet these challenges. One of the key parameters is the determination of particle shape and structure in three dimensions. Here two approaches to determining nanoparticle structure are described and demonstrated. In the first scanning transmission electron microscopy combined with high angle annular dark field imaging (HAADF-STEM) is used to image homogenous nanoparticles, where the contrast is directly related to the thickness of the material in the electron beam. It is shown that this can be related to the three dimensional shape of the nano-object. High resolution TEM imaging, combined with fast Fourier transform (FFT) analysis, can determine the crystalline structure and orientation of nanoparticles as well as the presence of any defects. This combined approach allows the physical structure of a significant number of nano-objects to be characterised, relatively quickly.

Boyd, Robert D.; Gunnarsson, Rickard; Pilch, Iris; Helmersson, Ulf

2014-06-01

412

High resolution thermal infrared mapping of Martian channels  

NASA Technical Reports Server (NTRS)

Viking Infrared Thermal Mapper (IRTM) high resolution (2 to 5 km) data were compiled and compared to Viking Visual Imaging Subsystem (VIS) data and available 1:5M geologic maps for several Martian channels including Dao, Harmakhis, Mangala, Shalbatana, and Simud Valles in an effort to determine the surface characteristics and the processes active during and after the formation of these channels. Results show a dominance of aeolian processes active in and around the channels. These processes have left materials thick enough to mask any genuine channel deposits. Results also indicate that very comparable Martian channels and their surrounding terrain are blanketed by deposits which are homogeneous in their thermal inertia values. However, optimum IRTM data does not cover the entire Martian surface and because local deposits of high thermal inertia material may not be large enough in areal extent or may be in an unfavorable location on the planet, a high resolution data track may not always occur over these deposits. Therefore, aeolian processes may be even more active than the IRTM data tracts can always show.

Craddock, R. A.; Greeley, R.; Christensen, P. R.

1987-01-01

413

The Astro-E High Resolution X-Ray Spectrometer  

NASA Technical Reports Server (NTRS)

The Astro-E High Resolution X-ray Spectrometer (XRS) was developed jointly by the NASA/Goddard Space Flight Center and the Institute of Space and Astronautical Science in Japan. The instrument is based on a new approach to spectroscopy, the X-ray microcalorimeter. This device senses the energies of individual X-ray photons as heat with extreme precision. A 32 channel array of microcalorimeters is being employed, each with an energy resolution of about 12 eV at 6 keV (the Fe-K region). This will provide spectral resolving power 10 times higher than any other non-dispersive X-ray spectrometer. The instrument incorporates a three stage cooling system capable of operating the array at 60 mK for about two years in orbit. The array sits at the focus of a grazing incidence conical mirror. The quantum efficiency of the microcalorimeters and the reflectivity of the X-ray mirror system combine to give high throughput over the 0.3-12 keV energy band. This new capability will enable the study of a wide range of high-energy astrophysical sources with unprecedented spectral sensitivity. This paper presents the basic design requirements and implementation of the XRS, and also describes the instrument parameters and performance.

Kelley, Richard L.; Audley, Michael D.; Boyce, Kevin R.; Breon, Susan R.; Fujimoto, Ryuichi; Gendreau, Keith C.; Holt, Stephen S.; Ishisaki, Yoshitaka; McCammon, Dan; Mihara, Tatehiro

1999-01-01

414

The High-Resolution Coronal Imager (Hi-C)  

NASA Astrophysics Data System (ADS)

The High-Resolution Coronal Imager (Hi-C) was flown on a NASA sounding rocket on 11 July 2012. The goal of the Hi-C mission was to obtain high-resolution (? 0.3 - 0.4''), high-cadence (? 5 seconds) images of a solar active region to investigate the dynamics of solar coronal structures at small spatial scales. The instrument consists of a normal-incidence telescope with the optics coated with multilayers to reflect a narrow wavelength range around 19.3 nm (including the Fe xii 19.5-nm spectral line) and a 40964096 camera with a plate scale of 0.1'' pixel-1. The target of the Hi-C rocket flight was Active Region 11520. Hi-C obtained 37 full-frame images and 86 partial-frame images during the rocket flight. Analysis of the Hi-C data indicates the corona is structured on scales smaller than currently resolved by existing satellite missions.

Kobayashi, Ken; Cirtain, Jonathan; Winebarger, Amy R.; Korreck, Kelly; Golub, Leon; Walsh, Robert W.; De Pontieu, Bart; DeForest, Craig; Title, Alan; Kuzin, Sergey; Savage, Sabrina; Beabout, Dyana; Beabout, Brent; Podgorski, William; Caldwell, David; McCracken, Kenneth; Ordway, Mark; Bergner, Henry; Gates, Richard; McKillop, Sean; Cheimets, Peter; Platt, Simon; Mitchell, Nick; Windt, David

2014-11-01

415

High-Resolution Polarimetry of Supernova Remnant Kesteven 69  

NASA Astrophysics Data System (ADS)

Reported here are high-resolution 6 cm measurements of the adolescent supernova remnant (SNR) Kesteven 69 made with the hybrid BnC configuration of the Very Large Array. Several three-field mosaics of the polarized and total intensity have been used to study this SNR. These investigations lead to a coherent picture of this region. The expanding shock defines an outer rim of high total intensity, suggesting the front is running into large dense clouds with random magnetic field directions. The SNR consists of predominantly of two types of regions, those with high total and relatively weak polarized emission and those with relatively weak total and strong polarized emission. This morphology can be generally explained by the number of clouds with organized magnetic field along the line of sight. Within this SNR there are regions where the field is varying from radial to tangential. As the SN shock encounters clouds, magnetic fields within clouds will strongly affect cloud dynamics.

Wood, C. A.; Mufson, S. L.; Dickel, J. R.

2008-06-01

416

High resolution spectroscopy from low altitude satellites. [gamma ray astronomy  

NASA Technical Reports Server (NTRS)

The P 78 1 satellite to be placed in a synchronous polar orbit at an altitude of 550-660 km will carry two identical high resolution spectrometers each consisting of a single (approximately 85 cc) intrinsic germanium IGE detector. The payload also includes a pair of phoswitch scintillators, an array of CdTe detectors and several particle detectors, all of which are mounted on the wheel of the satellite. The intrinsic high purity IGE detectors receive cooling from two Stirling cycle refrigerators and facilitate the assembly of large and complex detector arrays planned for the next generation of high sensitivity instruments such as those planned for the gamma ray observatory. The major subsystems of the spectrometer are discussed as well as its capabilities.

Nakano, G. H.; Imhof, W. L.

1978-01-01

417

High resolution low dose scattered gamma-ray tomography  

NASA Astrophysics Data System (ADS)

This paper discusses a technique which uses Compton scattered gamma radiation to obtain high contrast, highly spatially resolved, three-dimensional images in optically opaque objects. A highly desirable property of this technology is that this method allows the acquisition of radiographs without the necessity of placing the object between the source and detector. This paper describes a prototype apparatus which is capable of obtaining images with a spatial resolution of about 1 mm at a depth of 25 mm in steel of normal density with the source and detector both on the same side of the object. Some modeling calculations, reconstruction algorithms, and data verifying the performance of this technique will be presented as well as details of how the efficiency and throughput of this system could be increased by over two orders of magnitude.

Thoe, R. S.

1996-01-01

418

High resolution low dose scattered gamma-ray tomography  

SciTech Connect

This paper discusses a technique which uses Compton scattered gamma radiation to obtain high contrast, highly spatially resolved, three-dimensional images in optically opaque objects. A highly desirable property of this technology is that this method allows the acquisition of radiographs without the necessity of placing the object between the source and detector. This paper describes a prototype apparatus which is capable of obtaining images with a spatial resolution of about 1 mm at a depth of 25 mm in steel of normal density with the source and detector both on the same side of the object. Some modeling calculations, reconstruction algorithms, and data verifying the performance of this technique will be presented as well as details of how the efficiency and throughput of this system could be increased by over two orders of magnitude. {copyright} {ital 1996 American Institute of Physics.}

Thoe, R.S. [V Division, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)] [V Division, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

1996-01-01

419

High resolution remote sensing of water surface patterns  

NASA Astrophysics Data System (ADS)

The assessment of in-stream habitat availability within fluvial environments in the UK traditionally includes the mapping of patterns which appear on the surface of the water, known as 'surface flow types' (SFTs). The UK's River Habitat Survey identifies ten key SFTs, including categories such as rippled flow, upwelling, broken standing waves and smooth flow. SFTs result from the interaction between the underlying channel morphology, water depth and velocity and reflect the local flow hydraulics. It has been shown that SFTs can be both biologically and hydraulically distinct. SFT mapping is usually conducted from the river banks where estimates of spatial coverage are made by eye. This approach is affected by user subjectivity and inaccuracies in the spatial extent of mapped units. Remote sensing and specifically the recent developments in unmanned aerial systems (UAS) may now offer an alternative approach for SFT mapping, with the capability for rapid and repeatable collection of very high resolution imagery from low altitudes, under bespoke flight conditions. This PhD research is aimed at investigating the mapping of SFTs using high resolution optical imagery (less than 10cm) collected from a helicopter-based UAS flown at low altitudes (less than 100m). This paper presents the initial findings from a series of structured experiments on the River Arrow, a small lowland river in Warwickshire, UK. These experiments investigate the potential for mapping SFTs from still and video imagery of different spatial resolutions collected at different flying altitudes and from different viewing angles (i.e. vertical and oblique). Imagery is processed using 3D mosaicking software to create orthophotos and digital elevation models (DEM). The types of image analysis which are tested include a simple, manual visual assessment undertaken in a GIS environment, based on the high resolution optical imagery. In addition, an object-based image analysis approach which makes use of the spectral and textural images properties is tested using Definiens eCognition software. Where possible, the DEM of the water surface topography is also analysed for identifying SFTs. The site is revisited in order to assess the temporal variability of SFTs as relating to changes in flow level, and the potential for variability in identifying SFTs from imagery as relating to changes in lighting and weather conditions.

Woodget, A.; Visser, F.; Maddock, I.; Carbonneau, P.

2012-12-01

420

High Resolution Digital Elevation Models of Pristine Explosion Craters  

NASA Technical Reports Server (NTRS)

In order to effectively capture a realistic terrain applicable to studies of cratering processes and landing hazards on Mars, we have obtained high resolution digital elevation models of several pristine explosion craters at the Nevada Test Site. We used the Airborne Terrain Mapper (ATM), operated by NASA's Wallops Flight Facility to obtain DEMs with 1 m spacing and 10 cm vertical errors of 4 main craters and many other craters and collapse pits. The main craters that were mapped are Sedan, Scooter, Schooner, and Danny Boy. The 370 m diameter Sedan crater, located on Yucca Flat, is the largest and freshest explosion crater on Earth that was formed under conditions similar to hypervelocity impact cratering. As such, it is effectively pristine, having been formed in 1962 as a result of a controlled detonation of a 100 kiloton thermonuclear device, buried at the appropriate equivalent depth of burst required to make a simple crater. Sedan was formed in alluvium of mixed lithology and subsequently studied using a variety of field-based methods. Nearby secondary craters were also formed at the time and were also mapped by ATM. Adjacent to Sedan and also in alluvium is Scooter, about 90 m in diameter and formed by a high-explosive event. Schooner (240 m) and Danny Boy (80 m) craters were also important targets for ATM as they were excavated in hard basalt and therefore have much rougher ejecta. This will allow study of ejecta patterns in hard rock as well as engineering tests of crater and rock avoidance and rover trafficability. In addition to the high resolution DEMs, crater geometric characteristics, RMS roughness maps, and other higher-order derived data products will be generated using these data. These will provide constraints for models of landing hazards on Mars and for rover trafficability. Other planned studies will include ejecta size-frequency distribution at the resolution of the DEM and at finer resolution through air photography and field measurements, correlation of ejecta size and composition with radar and visible-thermal IR remote sensing signatures, and comparison of these results with similar measurements of Mars. The final DEMs, ancillary data sets, and derived data products will be made available to the community.

Farr, T. G.; Krabill, W.; Garvin, J. B.

2004-01-01

421

High Resolution X-ray Views of Solar System Objects  

NASA Astrophysics Data System (ADS)

Over the last decade Chandra, and XMM-Newton, have revealed the beauty and multiplicity of X-ray emissions in our solar system: high resolution data, in both spectral and spatial domains, have been crucial in disentangling the physical processes at work. The talk will review the main findings in this area at the boundary between astrophysics and planetary science, and will show how the solar system offers `next door examples of widespread astrophysical phenomena. Jupiter shows bright X-ray aurorae, arising from the interactions of local and/or solar wind ions, and electrons, with its powerful magnetic environment: the ions undergo charge exchange with atmospheric neutrals and generate soft X-ray line emission, and the electrons give rise to bremsstrahlung X-rays. Chandra's unparalleled spatial resolution has shown how the X-ray footprints of the electrons in the aurorae coincide with the bright FUV auroral oval, indicating that the same electron population is likely to be at the origin of both emissions. Moreover, Jupiter's disk scatters solar X-rays, displaying a spectrum that closely resembles that of solar flares. Saturn has not revealed X-ray aurorae (yet), but its disk X-ray brightness, like Jupiter's, is strictly correlated with the Sun's X-ray output. A bright X-ray spot has also been resolved by Chandra on the eastern ansa of Saturn's rings, and its spectrum suggests an origin in the fluorescent scattering of solar X-rays on the rings icy particles. Both Mars and Venus have X-ray emitting disks and exospheres, which can be clearly resolved at high spectral and spatial resolution. And the Earth has bright X-ray aurorae that have been targets of Chandra observations. Finally, comets, with their extended neutral comae and extremely line-rich X-ray spectra, are spectacular X-ray sources, and ideal probes of the conditions of the solar wind in the Sun's proximity.

Branduardi-Raymont, Graziella

2011-05-01

422

High Resolution Atmospheric Modeling for Wind Energy Applications  

SciTech Connect

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

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

2010-03-18

423

The AT20G high-angular-resolution catalogue  

NASA Astrophysics Data System (ADS)

We present the high-angular-resolution catalogue for the Australia Telescope 20 GHz (AT20G) survey, using the high-angular-resolution 6-km antenna data at the baselines of 4500 m of the Australia Telescope Compact Array. We have used the data to produce the visibility catalogue that separates the compact active galactic nuclei (AGNs) from the extended radio sources at the 0.15 arcsec angular scale, corresponding to the linear size scale of 1 kpc at redshifts higher than 0.7. We find the radio population at 20 GHz to be dominated by compact AGNs constituting 77 per cent of the total sources in the AT20G. We introduce the visibility-spectra diagnostic plot, produced using the AT20G cross-matches with lower frequency radio surveys at 1 GHz [the NRAO VLA Sky Survey (NVSS) and the Sydney University Molonglo Sky Survey (SUMSS)], that separates the 20 GHz population into distinct sub-populations of the compact AGNs, the compact steep-spectrum (CSS) sources, the extended AGN-powered sources and extended flat-spectrum sources. The extended flat-spectrum sources include a local thermal emitting population of high-latitude planetary nebulae and also gravitational lens and binary black hole candidates among the AGNs. We find a smooth transition in properties between the CSS sources and the AGN populations. The visibility catalogue, together with the main AT20G survey, provides an estimate of angular size scales for sources in the AT20G and an estimate of the flux arising from central cores of extended radio sources. The identification of the compact AGNs in the AT20G survey provides high-quality calibrators for high-frequency radio telescope arrays and very large baseline interferometry observations.

Chhetri, R.; Ekers, R. D.; Jones, P. A.; Ricci, R.

2013-09-01

424

High resolution sequence stratigraphic concepts applied to geostatistical modeling  

SciTech Connect

Lithofacies simulations using a high resolution 3D grid allow to enhance the geometries of internal heterogeneities of reservoirs. In this study the series simulated were the Ness formation, part of the Brent reservoir in the Dunbar field located in the Viking graben of the North Sea. Simulations results have been used to build the reservoir layering supporting the 3D grid used for reservoir engineering, and also used as a frame to study the effects of secondary diagenetic processes on petrophysical properties. The method used is based on a geostatistical study and integrates the following data: a geological model using sequence stratigraphic concepts to define lithofacies sequences and associated bounding surfaces, well data (cores and logs) used as database for geostatistical analysis and simulations, seismic data: a 3D seismic survey has been used to define the internal surfaces bounding the units, outcrop data: The Mesa Verde formation (Colorado, USA) has been used as an outcrop analog to calibrate geostatistical parameters for the simulations (horizontal range of the variograms). This study illustrates the capacity to use high resolution sequence stratigraphic concepts to improve the simulations of reservoirs when the lack of subsurface information reduce the accuracy of geostatistical analysis.

Desaubliaux, G. [Institut Francais du Petrole, Rueil Malmaison (France); De Lestang, A.P. [Beicip-Franlab, Rueil Malmaison (France); Eschard, R. [Institut Francais du Petrole, Rueil Malmaison (France)] [and others

1995-08-01

425

A High Resolution Survey of the Disk of M31  

NASA Technical Reports Server (NTRS)

This report describes research activities funded for SAO Proposal P3481-5-95, "Monitoring the Center of M31". Related activities for SAO Proposal P3486- 5-95, "A High-Resolution Survey of the Disk of M31" are also described. The research involved the data analysis and interpretation of eleven separate ROSAT (Roentgen Satellite) HRI (High Resolution Imager) observations of the center and inner disk of M31, obtained between July, 1990 and January, 1997. A log of the individual data sets is given. All proposed observations were successfully carried out by the ROSAT Observatory, and standard data products were successfully generated for each observation. There were two basic thrusts to the research. First, we wished to monitor the x-ray source nearest the nucleus of M31, to search for anti-correlated radio/x-ray variability predicted by theoretical models for the source. We would also be able to assess the degree and range of variability of other x-ray sources in the central bulge of M31 and to estimate rates of transients. Secondly, we wished to survey the entire inner disk of M31, and in particular the region covered by the recent MIT wide-band and narrow-band surveys to identify x-ray counterparts to supernova remnants, OB associations, and young blue stars, in areas in which the ROSAT PSPC survey was confused. Results of each research project are summarized. Papers describing the results in more detail are in preparation.

Primini, Francis A.

2000-01-01

426

High resolution multi-temperature sensors for biomedical application.  

PubMed

A temperature sensor array was designed in order to study local temperature variations and temperature gradients in biological samples. The sensor probe was inserted in the optical cortex of rabbits in order to study temperature changes during normal brain activity as well as under artificial ventilation conditions. Temperature sensitive areas of 0.14 mm x 0.1 mm are arranged in a row with interdistances of 0.4 mm yielding high spatial resolution. A temperature resolution of 0.1 mK and a 90% response time of maximum 3 milliseconds was obtained utilizing the high temperature dependence of 2%/K of the conductivity of vacuum evaporated germanium films. The sensor is passivated by a 1 micron thick PECVD-silicon nitride layer and can be placed on glass-, alumina- and polymer substrates. For brain tissue studies, in order to minimize tissue damage the temperature sensors were placed on a 0.1 mm thick needle-shaped glass substrate. A sensor element mounted on a glass substrate and immersed in water showed a self heating of less than 5 mK due to the applied measurement current of 2.1 microA. PMID:2146481

Urban, G; Jachimowicz, A; Kohl, F; Kuttner, H; Olcaytug, F; Goiser, P; Lindner, K; Pockberger, H; Prohaska, O; Schnauer, M

1990-01-01

427

Modeling Spatial Dependencies in High-Resolution Overhead Imagery  

SciTech Connect

Human settlement regions with different physical and socio-economic attributes exhibit unique spatial characteristics that are often illustrated in high-resolution overhead imageries. For example- size, shape and spatial arrangements of man-made structures are key attributes that vary with respect to the socioeconomic profile of the neighborhood. Successfully modeling these attributes is crucial in developing advanced image understanding systems for interpreting complex aerial scenes. In this paper we present three different approaches to model the spatial context in the overhead imagery. First, we show that the frequency domain of the image can be used to model the spatial context [1]. The shape of the spectral energy contours characterize the scene context and can be exploited as global features. Secondly, we explore a discriminative framework based on the Conditional Random Fields (CRF) [2] to model the spatial context in the overhead imagery. The features derived from the edge orientation distribution calculated for a neighborhood and the associated class labels are used as input features to model the spatial context. Our third approach is based on grouping spatially connected pixels based on the low-level edge primitives to form support-regions [3]. The statistical parameters generated from the support-region feature distributions characterize different geospatial neighborhoods. We apply our approaches on high-resolution overhead imageries. We show that proposed approaches characterize the spatial context in overhead imageries.

Cheriyadat, Anil M [ORNL] [ORNL; Bright, Eddie A [ORNL] [ORNL; Vatsavai, Raju [ORNL] [ORNL

2011-01-01

428

Limiting liability via high-resolution image processing  

NASA Astrophysics Data System (ADS)

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.

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

1997-01-01

429

Compressed Voxels for High-Resolution Phantom Simulations  

PubMed Central

Purpose We report here on a technique to implement high-resolution objects with voxels having variable dimensions (compressed) for the reduction of memory and central processing unit (CPU) requirements in Monte Carlo simulations. The technique, which was implemented in GATE, the GEANT4 application for positron emission tomography/single photon emission computed tomography (PET/SPECT) imaging simulations, was developed in response to our need for realistic high-resolution phantoms for dosimetry calculations. Procedures A compression algorithm similar to run-length encoding for one-dimensional data streams, was used to fuse together adjacent voxels with identical physical properties. The algorithm was verified by conducting dosimetric calculations and imaging experiments on compressed and uncompressed phantoms. Results Depending on the initial phantom size and composition, compression ratios of up to 99.9% were achieved allowing memory and CPU reductions of up to 85% and 70%, respectively. The output of the simulations was consistent with respect to the goals for each type of simulation performed (dosimetry and imaging). Conclusions The implementation of compressed voxels in GATE allows for significant memory and CPU reduction and is suitable for dosimetry as well as for imaging experiments. PMID:18046609

Taschereau, Richard; Chatziioannou, Arion F.

2010-01-01

430

Optimized generation of high resolution breast anthropomorphic software phantoms  

SciTech Connect

Purpose: The authors present an efficient method for generating anthropomorphic software breast phantoms with high spatial resolution. Employing the same region growing principles as in their previous algorithm for breast anatomy simulation, the present method has been optimized for computational complexity to allow for fast generation of the large number of phantoms required in virtual clinical trials of breast imaging. Methods: The new breast anatomy simulation method performs a direct calculation of the Cooper's ligaments (i.e., the borders between simulated adipose compartments). The calculation corresponds to quadratic decision boundaries of a maximum a posteriori classifier. The method is multiscale due to the use of octree-based recursive partitioning of the phantom volume. The method also provides user-control of the thickness of the simulated Cooper's ligaments and skin. Results: Using the proposed method, the authors have generated phantoms with voxel size in the range of (25-1000 {mu}m){sup 3}/voxel. The power regression of the simulation time as a function of the reciprocal voxel size yielded a log-log slope of 1.95 (compared to a slope of 4.53 of our previous region growing algorithm). Conclusions: A new algorithm for computer simulation of breast anatomy has been proposed that allows for fast generation of high resolution anthropomorphic software phantoms.

Pokrajac, David D.; Maidment, Andrew D. A.; Bakic, Predrag R. [Computer and Information Sciences Department, Delaware State University, Dover, Delaware 19901 (United States); Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States)

2012-04-15

431

High-resolution climatology of lightning characteristics within Central Europe  

NASA Astrophysics Data System (ADS)

A 6-year analysis (including data of 36 million strokes) of the spatial and temporal occurrence of lightning strokes in Germany and neighbouring areas is presented. The analysis on a high-resolution grid with spatial resolution of 1 km allows assessing the local risk of lightning and studying local effects, e.g. the influence of orography on the occurrence of thunderstorms. The analysis reveals spatial and temporal patterns: the highest number of lightning strokes occurs in the pre-alpine region of southern Germany, further local maxima exists in low mountain ranges. The lowest number of lightning strokes 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) are present. In addition to this well-known annual and diurnal pattern, the analysis shows 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, the annual cycle of lightning is varying geographically, e.g. offshore and coastal regions show a lower amplitude of the annual cycle and a later maximum (autumn) compared to inland (mountainous) regions. In addition, the annual and diurnal cycles of lightning attributes are analysed. The analysis reveals rising height of inner-cloud lightning during the year with a maximum in late summer.

Wapler, Kathrin

2013-11-01

432

High Resolution Spectral Analysis for Irregularly Sampled Helioseismic Data  

NASA Astrophysics Data System (ADS)

Astronomical ground based data are very often irregularly sampled due to many factors such as: diurnal effect, weather conditions, etc. The analysis of such data cannot be performed with classical tools (such as periodigram) and new adapted methods are required. After presenting some of these techniques, we will focus on a regularized approach of the spectral analysis problem, which gives very good results in the case of band limited and narrow peaks spectrum. We will also show that with this approach we can achieve high-resolution spectra. Indeed, in classical Fourier analysis, spectral resolution is inversely proportional to the observation time T. Considering the spectral analysis problem as an inverse problem and introducing the a priori knowledge of band limited and narrow peak spectrum, this limit (1/T) can be exceeded and thus we can achieve highly resolved spectra, even with irregularly sampled data. This technique will be first applied to relevant simulated data, then to helioseismic data. Additional talk: Brief description of solar projects in Algiers Observatory A brief description of all projects developed in our department and that are related to the sun: helioseismology, solar data analysis (pipelines description), solar activity, VLF project, solar astrolabe (for solar diameter measurement), site testing for day-time observations, and the project of solar observatory in the Tamanrasset area.

Seghouani, N.

2006-11-01

433

High-resolution structure prediction and the crystallographic phase problem.  

PubMed

The energy-based refinement of low-resolution protein structure models to atomic-level accuracy is a major challenge for computational structural biology. Here we describe a new approach to refining protein structure models that focuses sampling in regions most likely to contain errors while allowing the whole structure to relax in a physically realistic all-atom force field. In applications to models produced using nuclear magnetic resonance data and to comparative models based on distant structural homologues, the method can significantly improve the accuracy of the structures in terms of both the backbone conformations and the placement of core side chains. Furthermore, the resulting models satisfy a particularly stringent test: they provide significantly better solutions to the X-ray crystallographic phase problem in molecular replacement trials. Finally, we show that all-atom refinement can produce de novo protein structure predictions that reach the high accuracy required for molecular replacement without any experimental phase information and in the absence of templates suitable for molecular replacement from the Protein Data Bank. These results suggest that the combination of high-resolution structure prediction with state-of-the-art phasing tools may be unexpectedly powerful in phasing crystallographic data for which molecular replacement is hindered by the absence of sufficiently accurate previous models. PMID:17934447

Qian, Bin; Raman, Srivatsan; Das, Rhiju; Bradley, Philip; McCoy, Airlie J; Read, Randy J; Baker, David

2007-11-01

434

Very High Resolution Image of Icy Cliffs on Europa  

NASA Technical Reports Server (NTRS)

This image, taken by the camera onboard NASA's Galileo spacecraft, is a very high resolution view of the Conamara Chaos region on Jupiter's moon Europa. It shows an area where icy plates have been broken apart and moved around laterally. The top of this image is dominated by corrugated plateaus ending in icy cliffs over a hundred meters (a few hundred feet) high. Debris piled at the base of the cliffs can be resolved down to blocks the size of a house. A fracture that runs horizontally across and just below the center of the Europa image is about the width of a freeway.

North is to the top right of the image, and the sun illuminates the surface from the east. The image is centered at approximately 9 degrees north latitude and 274 degrees west longitude. The image covers an area approximately 1.7 kilometers by 4 kilometers (1 mile by 2.5 miles). The resolution is 9 meters (30 feet) per picture element. This image was taken on December 16, 1997 at a range of 900 kilometers (540 miles) by Galileo's solid state imaging system.

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

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

1998-01-01

435

High-Resolution Displacement Sensor Using a SQUID Array Amplifier  

NASA Technical Reports Server (NTRS)

Improvement in the measurement of displacement has profound implications for both exploration technologies and fundamental physics. For planetary exploration, the new SQUID-based capacitive displacement sensor will enable a more sensitive gravity gradiometer for mapping the interior of planets and moons. A new concept of a superfluid clock to be reported by Penanen and Chui at this workshop is also based on a high-resolution displacement sensor. Examples of high-impact physics projects that can benefit from a better displacement sensor are: detection of gravitational waves, test of the equivalence principle, search for the postulated "axion" particle, and test of the inverse square law of gravity. We describe the concept of a new displacement sensor that makes use of a recent development in the Superconducting Quantum Interference Device (SQUID) technology. The SQUID array amplifier, invented by Welty and Martinis (IEEE Trans. Appl. Superconductivity 3, 2605, 1993), has about the same noise as a conventional SQUID; however, it can work at a much higher frequency of up to 5 MHz. We explain how the higher bandwidth can be translated into higher resolution using a bridge-balancing scheme that can simultaneously balance out both the carrier signal at the bridge output and the electrostatic force acting on the test mass.

Chui, Talso; Penanen, Konstantin; Barmatz, M.; Paik, Ho Jung

2004-01-01

436

Segmentation of Striatal Brain Structures from High Resolution PET Images  

PubMed Central

We propose and evaluate an automatic segmentation method for extracting striatal brain structures (caudate, putamen, and ventral striatum) from parametric 11C-raclopride positron emission tomography (PET) brain images. We focus on the images acquired using a novel brain dedicated high-resolution (HRRT) PET scanner. The segmentation method first extracts the striatum using a deformable surface model and then divides the striatum into its substructures based on a graph partitioning algorithm. The weighted kernel k-means algorithm is used to partition the graph describing the voxel affinities within the striatum into the desired number of clusters. The method was experimentally validated with synthetic and real image data. The experiments showed that our method was able to automatically extract caudate, ventral striatum, and putamen from the images. Moreover, the putamen could be subdivided into anterior and posterior parts. An automatic method for the extraction of striatal structures from high-resolution PET images allows for inexpensive and reproducible extraction of the quantitative information from these images necessary in brain research and drug development. PMID:19911061

Farinha, Ricardo J. P. C.; Ruotsalainen, Ulla; Hirvonen, Jussi; Tuominen, Lauri; Hietala, Jarmo; Fonseca, Jose M.; Tohka, Jussi

2009-01-01

437