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1

High-Resolution Autoradiography  

NASA Technical Reports Server (NTRS)

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

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

1955-01-01

2

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

3

High resolution track etch autoradiography  

DOEpatents

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

Solares, G.; Zamenhof, R.G.

1994-12-27

4

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

5

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

E-print Network

the tradeoffs between the use of autoradiography and small animal PET for functional brain imaging studies investigative possibilities. Small animal PET is however, not suitable for all functional brain imaging studies. In this respect, quantitative autoradiography and PET functional imaging methods contrast with other methods

Smith, Carolyn Beebe

6

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

7

Skin research and drug localization with receptor microscopic autoradiography  

Microsoft Academic Search

For the localization of drugs and related functional characterization, cellular-subcellular resolution can be achieved with radiolabelled compounds of high specific activity and receptor microscopic autoradiography, which is the method of choice for high-resolution qualitative and quantitative imaging. Detailed information together with integrative surveys can be obtained which is impossible with other methods. The history of discoveries of drug targets testifies

Walter E. Stumpf; Naohiko Hayakawa; Hans-Juergen Bidmon

2007-01-01

8

High resolution data acquisition  

DOEpatents

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

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

1993-04-06

9

High resolution data acquisition  

DOEpatents

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

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

1993-01-01

10

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

SciTech Connect

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

Appel, N.M.; Mitchell, W.M.; Contrera, J.F.; De Souza, E.B. (NIDA Addiction Research Center, Baltimore, MD (USA))

1990-01-01

11

High resolution electrocardiography.  

PubMed

Over the past decade, significant advances were made in the research, diagnosis, and treatment of cardiovascular diseases. Such progress was in every sphere of cardiology that includes non-invasive, minimally invasive, and invasive technologies. Interpretive electrocardiography, cardiac pacemakers, cardiac stents, and angioplasty are some areas where the progress has been significant. Non-invasive methods of diagnosis of cardiac disorders involve digital recording of cardiac signals at the body surface (chest) and subsequent computerized analysis. Such methods and instruments provide a vital first step to the diagnosis of the heart without involving surgical procedures. One such non-invasive field is High Resolution Electrocardiography (HRECG). A high-resolution electrocardiogram detects very low amplitude signals in the ventricles called 'Late Potentials' in patients with abnormal heart conditions. A standard electrocardiogram cannot detect these signals. The presence of late potentials is widely accepted to have prognostic significance in patients after Acute Myocardial Infarction (AMI) High Resolution Electrocardiography enhances the diagnostic capabilities of ECGs. This article describes the principles involved in HRECG and the techniques that are employed to derive such superior diagnostic capabilities. The use of these techniques may lead to more discoveries in the causes of cardiac disorders and improved drug discoveries to combat such conditions. PMID:17006557

Narayanaswamy, S

2002-01-01

12

Autoradiography techniques and quantification of drug distribution.  

PubMed

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

Solon, Eric G

2015-04-01

13

Scanning electron microscopic autoradiography of lung  

SciTech Connect

Scanning electron microscopic (SEM) autoradiography of the lung is being used to determine the distribution of inhaled, alpha particle-emitting, plutonium dioxide particles. SEM autoradiography provides high visual impact views of alpha activity. Particles irradiating the bronchiolar epithelium were detected both on the bronchiolar surface and in peribronchiolar alveoli. The technique is being used to obtain quantitative data on the clearance rates of plutonium particles from bronchi and bronchioles.

Lauhala, K.E.; Sanders, C.L.; McDonald, K.E.

1988-09-01

14

Miranda - High Resolution Mosaic  

NASA Technical Reports Server (NTRS)

This computer-assembled mosaic of Miranda includes many of the high-resolution frames obtained by Voyager 2 during its close flyby of the Uranian moon. Miranda, roughly 500 kilometers (300 miles) in diameter, exhibits varied geologic provinces, seen in this mosaic of clear-filter, narrow-angle images from Jan. 24, 1986. The images were obtained from distances of 30,160 to 40,310 km (18,730 to 25,030 mi); resolution ranges from 560 to 740 meters (1,840 to 2,430 feet). These are among the highest-resolution pictures that Voyager has obtained of any of the new 'worlds' it has encountered during its mission. On Miranda, ridges and valleys of one province are cut off against the boundary of the next province. Probable compressional (pushed-together) folded ridges are seen in curvilinear patterns, as are many extensional (pulled-apart) faults. Some of these show very large scarps, or cliffs, ranging from O.5 to 5 km (O.3 to 3 mi) in height -- that is, higher that the walls of the Grand Canyon on Earth. The missing piece of Miranda's surface will be included in a later mosaic once more complicated computer processing can be completed. The Voyager project is managed for NASA by the Jet Propulsion Laboratory.

1986-01-01

15

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

16

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

17

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

18

High resolution hypernuclear spectroscopy  

SciTech Connect

Hypernuclear spectroscopy provides fundamental information for understanding the effective ?-Nucleon interaction. Jefferson Laboratory experiment E94-107 was designed to perform high resolution hypernuclear spectroscopy by electroproduction of strangeness in four 1p-shell nuclei: 12C, 9Be, 16O, and 7Li. The first part of the experiment on 12C and 9Be has been performed in January and April-May 2004 in Hall A at Jefferson Lab. Significant modifications were made to the standard Hall A apparatus for this challenging experiment: two septum magnets and a RICH detector have been added to get reasonable counting rates and excellent particle identification, as required for the experiment. A description of the apparatus and the preliminary analysis results are presented here.

F. Garibaldi

2005-02-01

19

High resolution Doppler lidar  

NASA Technical Reports Server (NTRS)

A high resolution lidar system was implemented to measure winds in the lower atmosphere. The wind speed along the line of sight was determined by measuring the Doppler shift of the aerosol backscattered laser signal. The system in its present configuration is stable, and behaves as indicated by theoretical simulations. This system was built to demonstrate the capabilities of the detector system as a prototype for a spaceborne lidar. The detector system investigated consisted of a plane Fabry-Perot etalon, and a 12-ring anode detector. This system is generically similar to the Fabry-Perot interferometer developed for passive wind measurements on board the Dynamics Explorer satellite. That this detector system performs well in a lidar configuration was demonstrated.

Abreu, Vincent J.; Hays, Paul B.; Barnes, John E.

1989-01-01

20

High resolution time interval meter  

DOEpatents

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

Martin, A.D.

1986-05-09

21

ANL high-resolution injector  

SciTech Connect

The ANL (Argonne National Laboratory) high-resolution injector has been installed to obtain higher mass resolution and higher preacceleration, and to utilize effectively the full mass range of ATLAS (Argonne tandem linac accelerator system). Preliminary results of the first beam test are reported briefly. The design and performance, in particular a high-mass-resolution magnet with aberration compensation, are discussed.

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

1986-05-01

22

High resolution radar imaging  

NASA Astrophysics Data System (ADS)

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 could be acquired with a high-resolution radar-imaging system operating with an optical-or radio-frequency carrier. Two approaches are under study. The first is motivated by an image-reconstruction algorithm used in radionuclide imaging called the confidence-weighted algorithm; here, we will refer to this approach as the chirp-rate modulation approach. The second approach is based on more fundamental principles which starts with a mathematical model that accurately describes the physics of an imaging radar-system and then uses statistical-estimation theory with this model to derive processing algorithms; we will refer to this as the estimation-theory approach. Progress during this reporting period has been made on: (1) extending the estimation-theory approach to include a constraint on input signal-to-noise ratio; (2) extending the estimation-theory approach to include a sieve constraint for stabilizing image estimates, (3) extending the estimation-theory approach to include a specular or glint component in the radar-echo data; (4) analyzing the performance of the estimation-theory approach through computer simulations; and (5) modifying the chirp-rate modulation approach through the introduction of the Wigner-Ville distribution. A patent was awarded associated with the chirp-rate modulation approach.

Snyder, Donald L.

1988-11-01

23

High Resolution Nanoimprint for Nanophotonics  

E-print Network

of SERS-active device depends on two main factors: good reproducibility and high enhancement factor. Ordered metallic nanostructures with high resolution are usually preferred for SERS application. Nanoimprint lithography can provide a low-cost and high...

Jiang, Youwei

2014-04-28

24

High Resolution Formaldehyde Photochemistry  

NASA Astrophysics Data System (ADS)

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

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

2010-12-01

25

High resolution telescope  

DOEpatents

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

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

1992-01-01

26

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

27

A high resolution TDC subsystem  

Microsoft Academic Search

A high resolution TDC subsystem was developed at the Institute for Nuclear Physics in Mainz. The TDC chip offers a time resolution of less than 300 ps and a programmable measurement range from O to 16 ?sec. The time measurement is done with a new, purely digital counting method. The chip can be operated in common start or common stop

R. Geiges; K. Merle

1994-01-01

28

High resolution signal processing  

NASA Astrophysics Data System (ADS)

Motivated by the goal of efficient, effective, high-speed integrated-circuit realization, we have discovered an algorithm for high speed Fourier analysis called the Arithmetic Fourier Transform (AFT). It is based on the number-theoretic method of Mobius inversion, a method that is well suited for integrated-circuit realization. The computation of the AFT can be carried out in parallel, pipelined channels, and the individual operations are very simple to execute and control. Except for a single scaling in each channel, all the operations are additions or subtractions. Thus, it can reduce the required power, volume, and cost. Also, analog switched-capacitor realizations of the AFT have been studied. We have also analyzed the performance of a broad and useful class of data adaptive signal estimation algorithms. This in turn has led to our proposed improvements in the methods. We have used perturbation analysis of the rank-reduced data matrix to calculate its statistical properties. The improvements made have been demonstrated by computer simulation as well as by comparison with the Cramer-Rao Bound.

Tufts, Donald W.

1993-08-01

29

High Resolution Doppler Lidar  

NASA Technical Reports Server (NTRS)

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

1996-01-01

30

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

31

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

32

High resolution AMS imaging of radiocarbon in biomedical applications  

NASA Astrophysics Data System (ADS)

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

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

1997-03-01

33

High resolution tomographic instrument development  

NASA Astrophysics Data System (ADS)

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

34

HRSC: High resolution stereo camera  

USGS Publications Warehouse

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

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

2009-01-01

35

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

36

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

37

A high resolution TDC subsystem  

SciTech Connect

A high resolution TDC subsystem was developed at the Institute for Nuclear Physics in Mainz. The TDC chip offers a time resolution of less than 300 ps and a programmable measurement range from 0 to 16 [mu]sec. The time measurement is done with a new, purely digital counting method. The chip can be operated in common start or common stop mode. In common start mode the chip is able to store up to 4 multiple hits per channel. The chip is used to build a transputer controlled subsystem for the measurement of the drift times of a vertical drift chamber. The design of the subsystem will be described and the first results from the tests of the prototype system will be presented.

Geiges, R.; Merle, K. (Mainz Univ. (Germany))

1994-02-01

38

Global high resolution climate reconstructions  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

39

High Resolution Scanning Reflectarray Antenna  

NASA Technical Reports Server (NTRS)

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

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

2000-01-01

40

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

41

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 µm below the surface. Thus, we are for the first time able to visualize the dynamic interactions between B cells and immune complex deposits on follicular dendritic cells within germinal centers (GCs) of live mice. These interactions play a decisive role in the process of clonal selection, leading to affinity maturation of the humoral immune response. This novel high-resolution intravital microscopy method has a huge potential for numerous applications in neurosciences, immunology, cancer research and developmental biology. 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; Günther, Robert; Spiecker, Heinrich; Radbruch, Helena; Gerhard, Jenny; Sporbert, Anje; Cseresnyes, Zoltan; Hauser, Anja E.; Niesner, Raluca

2012-01-01

42

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

43

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

44

A simple, high efficiency, high resolution spectropolarimeter  

NASA Astrophysics Data System (ADS)

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

Barden, Samuel C.

2012-09-01

45

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 1920×1200 microdisplay in a 0.86" diagonal area. In addition to the conventional matrix addressing circuitry, the HDTV+ display includes a very lowpower, low-voltage-differential-signaling (LVDS) serialized interface to minimize cable and connector size as well as electromagnetic emissions (EMI), an on-chip set of look-up-tables for digital gamma correction, and a novel pulsewidth- modulation (PWM) scheme that together with the standard analog control provides a total dimming range of 0.05cd/m2 to 2000cd/m2 in the monochrome version. The PWM function also enables an impulse drive mode of operation that significantly reduces motion artifacts in high speed scene changes. An internal 10-bit DAC ensures that a full 256 gamma-corrected gray levels are available across the entire dimming range, resulting in a measured dynamic range exceeding 20-bits. This device has been successfully tested for operation at frame rates ranging from 30Hz up to 85Hz. This paper describes the operational features and detailed optical and electrical test results for the new AMOLED WUXGA resolution microdisplay.

Wacyk, Ihor; Prache, Olivier; Ghosh, Amal

2011-06-01

46

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

47

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

48

High Resolution Imaging of Io  

Microsoft Academic Search

The technique of super-resolution imaging will be used to obtain near-IR images of Io with sufficient resolution to map the surface on this volcanically active satellite of Jupiter. A series of four images in each filter will be recorded with 4-point square dithering a distance of 91.5 pixel offsets { 4''}. This will provide a well-sampled data set that will

Rich Terrile

1997-01-01

49

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

50

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

51

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

52

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

NASA Astrophysics Data System (ADS)

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

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

2013-04-01

53

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

54

Direct beta autoradiography using microchannel plate (MCP) detectors  

NASA Astrophysics Data System (ADS)

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

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

1997-02-01

55

High Resolution Spectroscopy of Supernova Remnants  

Microsoft Academic Search

With the advent of XMM-Newton and Chandra, high resolution spectroscopy has become a new tool for investigating supernova remnants. In the near future it will become even more important as micro calorimeters are entering the field, for example with ASTRO-E2, Constellation-X and Xeus. High resolution spectroscopy is an important diagnostic tool for measuring plasma properties, such as plasma temperatures, non-equilibrium

J. Vink

2004-01-01

56

High-Resolution X-Ray Telescopes  

NASA Technical Reports Server (NTRS)

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

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

2010-01-01

57

Research of high range resolution lidar system  

NASA Astrophysics Data System (ADS)

Lidar system often use pulse range method, phase detection (PD) range method and linear frequency modulation continues wave (LFM/CW) range method. Each method has its limit between range resolution and no fuzzy range. In this paper, a Lidar system with high range resolution in a long distance is designed by using LFM/CW range method cooperating with PD range method. A MCU is used to control the system working on LFM/CW range mode and PD range mode alternately. In which LFM/CW range mode is used to obtain an approximate target range with low resolution in long distance, and PD range mode is used to obtain a high resolution range value within one resolution of LFM/CW range mode. Then use the PD mode's range value to amend the range from LFM/CW method, and achieve high range resolution in long distance. This paper describes the system's principle. The simulation and experiment results in typical object situation prove the system could achieve high range resolution effectively.

Wang, Qiao; Du, Xiao-ping; Zhao, Ji-guang

2011-06-01

58

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

59

High-Resolution Radar Imagery of Mars  

Microsoft Academic Search

We present high-resolution radar images of Mars obtained during the 2005 and 2007 oppositions. The images were constructed from long-code delay-Doppler observations made with the Arecibo S-band (13-cm) radar. The average image resolution of 3 km represented a better than order-of-magnitude improvement over pre-upgrade Arecibo imagery of the planet. Images of depolarized reflectivity (an indicator primarily of wavelength-scale surface roughness)

John K. Harmon; M. C. Nolan

2009-01-01

60

OPERATING MANUAL HIGH RESOLUTION MICROSTEP DRIVE  

E-print Network

). The CN0I65 uses high speed opto-isolators for the Step Pulse and the Direction inputs to provide maximum^ ^ o CN0165 OPERATING MANUAL HIGH RESOLUTION MICROSTEP DRIVE \\ J ^ M P A N Y 3879 SOUIH MAIN Linder-Voltage Lockout 15 PERFORMANCE Microslepping 15 .Anti-resonance 16 Torque and Power 17 Motor

Kleinfeld, David

61

High resolution schemes for hyperbolic conservation laws  

Microsoft Academic Search

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

A. Harten

1983-01-01

62

High-Resolution, High-Pressure NMR Studies of Proteins  

Microsoft Academic Search

Advanced high-resolution NMR spectroscopy, including two-dimensional NMR techniques, combined with high pressure capability, represents a powerful new tool in the study of proteins. This contribution is organized in the following way. First, the specialized instrumentation needed for high-pressure NMR experiments is discussed, with specific emphasis on the design features and performance characteristics of a high-sensitivity, high-resolution, variable-temperature NMR probe operating

J. Jonas; L. Ballard; D. Nash

1998-01-01

63

Initial Results from SOI\\/MDI High Resolution Magnetograms  

Microsoft Academic Search

The Michelson Doppler Imager (MDI) on SoHO takes magnetogram s with resolutions of 1.2 (high resolution) and 4 (full disk) arcseconds. Movies of 16 hour duration have been constructed in full disk and high resolution mode. High resolution movies of the south polar region also have been obtained. In sums of nine high resolution magnetograms it is possible to detect

T. Tarbell; Z. Frank; C. Schrijver; R. Shine; J. Wolfson; I. Zayer; P. Scherrer; R. Bush; C. Deforest; T. Hoeksema

1996-01-01

64

High-Resolution PET Detector. Final report  

SciTech Connect

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

Karp, Joel

2014-03-26

65

High spectral resolution reflectance spectroscopy of minerals  

USGS Publications Warehouse

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

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

1990-01-01

66

High Spatial Resolution Thermal Satellite Technologies  

NASA Technical Reports Server (NTRS)

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

Ryan, Robert

2003-01-01

67

Single shot high resolution digital holography.  

PubMed

We demonstrate a novel computational method for high resolution image recovery from a single digital hologram frame. The complex object field is obtained from the recorded hologram by solving a constrained optimization problem. This approach which is unlike the physical hologram replay process is shown to provide high quality image recovery even when the dc and the cross terms in the hologram overlap in the Fourier domain. Experimental results are shown for a Fresnel zone hologram of a resolution chart, intentionally recorded with a small off-axis reference beam angle. Excellent image recovery is observed without the presence of dc or twin image terms and with minimal speckle noise. PMID:23481715

Khare, Kedar; Ali, P T Samsheer; Joseph, Joby

2013-02-11

68

ELECTRONICS UPGRADE OF HIGH RESOLUTION MASS SPECTROMETERS  

SciTech Connect

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

Mcintosh, J; Joe Cordaro, J

2008-03-10

69

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.

70

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

71

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

72

High resolution matting via interactive trimap segmentation  

Microsoft Academic Search

We present a new approachto the mattingproblem which splits the task into two steps: interactive trimap extraction followed by trimap-based alpha matting. By doing so we gain considerably in terms of speed and quality and are able to deal with high resolution images. This paper has three contributions: (i) a new trimap segmentation method using parametric max-flow; (ii) an alpha

Christoph Rhemann; Carsten Rother; Alex Rav-acha; Toby Sharp

2008-01-01

73

The IMAGE High-Resolution Data Set  

Microsoft Academic Search

The entire IMAGE mission high resolution (level 0.5) data set is being archived in Universal Data Format (UDF). This data format is self-documenting, does not alter the incoming telemetry values, allows for easy access through a small number of generic software routines, and returns data in any physical unit for which an algorithm has been constructed. This paper discusses the

Chris Gurgiolo

2000-01-01

74

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

75

HIGH RESOLUTION PCB (POLYCHLORINATED BIPHENYLS) ANALYSIS  

EPA Science Inventory

The potential environmental and health impact of PCBs must account not only for the integrated quantitation of the PCBs mixtures but also the concentrations of the specific congeners which are potentially toxic. The authors confirm the feasibility of high resolution PCB analysis ...

76

Extragalactic science at very high spectral resolution  

E-print Network

I briefly mention a few possible applications of very high spectral resolution spectroscopy with CRIRES to the study of nearby galaxies. This includes the fields of AGN, dynamically cold systems, super stellar and emission line clusters, and a more speculative program on the measurement of gravitational redshifts.

Eric Emsellem

2004-09-27

77

High-resolution x-ray scattering  

SciTech Connect

Beamline and spectrometer instrumentation for high-resolution x-ray scattering at the Stanford Synchrotron Radiation Laboratory is described. The combination of photon intensity at the sample of approx. 10/sup 13/ photons/sec/10 mm/sup 2/ and the momentum-transfer resolution of ..delta..Q approx. 10/sup -4/ A/sup -1/ make this a unique facility. Examples are given of data obtained on two-dimensional phase transitions both in studies of thin (2 molecular layers) liquid-crystal films and rare-gas monolayers on pyrolytic-graphite substrates.

Moncton, D.E.; Brown, G.S.

1982-01-01

78

High-resolution dosimetry with stimulated phosphorescence.  

PubMed

Thermally stimulated radiophosphorescence has been studied as a means of high-resolution dosimetry. Small grains of CaSO4:Mn phosphor, embedded in a thin Teflon tape, constitute the dosimeter. The light emitted after irradiation is measured with a photomultiplier coupled to the eyepiece of a scanning microscope. With CaSO4:Mn, the phosphorescence at room temperature is sufficient for measurement after doses in excess of 3000 rads. The spatial resolution of the technique is about 0.2 mm. The method has been tested by measuring the dose distributions from a radium needle and a beta-emitting eye applicator. PMID:1256377

Bjärngard, B E; Chen, G T; Maddox, B J

1976-01-01

79

A Portable, High Resolution, Surface Measurement Device  

NASA Technical Reports Server (NTRS)

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

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

2012-01-01

80

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

81

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

82

High-resolution reconstruction for terahertz imaging.  

PubMed

We present a high-resolution (HR) reconstruction model and algorithms for terahertz imaging, taking advantage of super-resolution methodology and algorithms. The algorithms used include projection onto a convex sets approach, iterative backprojection approach, Lucy-Richardson iteration, and 2D wavelet decomposition reconstruction. Using the first two HR reconstruction methods, we successfully obtain HR terahertz images with improved definition and lower noise from four low-resolution (LR) 22×24 terahertz images taken from our homemade THz-TDS system at the same experimental conditions with 1.0 mm pixel. Using the last two HR reconstruction methods, we transform one relatively LR terahertz image to a HR terahertz image with decreased noise. This indicates potential application of HR reconstruction methods in terahertz imaging with pulsed and continuous wave terahertz sources. PMID:25607865

Xu, Li-Min; Fan, Wen-Hui; Liu, Jia

2014-11-20

83

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

84

Progress toward high resolution EUV spectroscopy  

NASA Astrophysics Data System (ADS)

HIgh resolution EUV spectroscopy is a critical instrumental technique to understand fundamental physical processes in the high temperature solar atmosphere. Spectroscopic observations are used to measure differential emission measure, line of sight and turbulent flows, plasma densities and emission measures. Spatially resolved, spectra of these emission lines with adequate cadence will provide the necessary clues linking small scale structures with large scale, energetic solar phenomena. The necessary observations to determine underlying physical processes and to provide comprehensive temperature coverage of the solar atmosphere above the chromosphere will be obtained by the proposed EUVST instrument for Solar C. This instrument and its design will be discussed in this paper. Progress on the VEry high Resolution Imaging Spectrograph (VERIS) sounding rocket instrument presently under development at the Naval Research Laboratory will also be discussed.

Korendyke, C.; Doschek, G. A.; Warren, H.; Young, P. R.; Chua, D.; Hassler, D. M.; Landi, E.; Davila, J. M.; Klimchuck, J.; Tun, S.; DeForest, C.; Mariska, J. T.; Solar C Spectroscopy Working Group; LEMUR; EUVST Development Team

2013-07-01

85

DKIST: Observing the Sun at High Resolution  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

86

A highly adaptive detector system for high resolution neutron imaging  

Microsoft Academic Search

An optimized detector system that allows high-resolution neutron imaging with desired flexibility is described. The presented system can be adapted and integrated with standard CCD-based neutron detectors. Novel neutron scintillating materials with good photon discrimination and optical lens components are tested and optimized for high-resolution neutron tomographic purposes. The presented detector system provides variable field of view and can be

N. Kardjilov; M. Dawson; A. Hilger; I. Manke; M. Strobl; D. Penumadu; F. H. Kim; F. Garcia-Moreno; J. Banhart

2011-01-01

87

SOHO - A high resolution solar physics mission  

NASA Technical Reports Server (NTRS)

The present study discusses SOHO (Solar and Heliospheric Observatory), a satellite with a pointing stability of 1 arcsec that will be launched in 1995 to the L1 Lagrangian point between the sun and the earth. In situ measurements, at approximately 1 AU, are to trace the results of solar wind expansion. The SOHO mission aims are discussed: to obtain long and uninterrupted series of solar oscillation measurements either in flux or in velocity in order to sound the solar interior using high resolution in the frequency domain; to probe the upper atmosphere with high-resolution UV/EUV imager/spectrometers and UV/visible coronagraphs and photometers in order to bring new constraints on the coronal heating; and to measure in situ the solar wind flow in front of the earth and thus establish the link between the sun and the near-earth environment. The satellite and instrumentation are reviewed in relation to the specific capabilities that they offer.

Lemaire, P.

1991-01-01

88

Information extraction from high resolution satellite images  

NASA Astrophysics Data System (ADS)

Information extracted from high resolution satellite images, such as roads, buildings, water and vegetation, has a wide range of applications in disaster assessment and environmental monitoring. At present, object oriented supervised learning is usually used in the objects identification from the high spatial resolution satellite images. In classical ways, we have to label some regions of interests from every image to be classified at first, which is labor intensive. In this paper, we build a feature base for information extraction in order to reduce the labeling efforts. The features stored are regulated and labeled. The labeled samples for a new coming image can be selected from the feature base. And the experiments are taken on GF-1 and ZY-3 images. The results show the feasibility of the feature base for image interpretation.

Yang, Haiping; Luo, Jiancheng; Shen, Zhanfeng; Xia, Liegang

2014-11-01

89

High-resolution broadband spectral interferometry  

NASA Astrophysics Data System (ADS)

We demonstrate solar spectra from a novel interferometric method for compact broadband high-resolution spectroscopy. The spectral interferometer (SI) is a hybrid instrument that uses a spectrometer to externally disperse the output of a fixed-delay interferometer. It also has been called an externally dispersed interferometer (EDI). The interferometer can be used with linear spectrometers for imaging spectroscopy or with echelle spectrometers for very broad-band coverage. EDI's heterodyning technique enhances the spectrometer's response to high spectral-density features, increasing the effective resolution by factors of several while retaining its bandwidth. The method is extremely robust to instrumental insults such as focal spot size or displacement. The EDI uses no moving parts, such as purely interferometric FTS spectrometers, and can cover a much wider simultaneous bandpass than other internally dispersed interferometers (e.g. HHS or SHS).

Erskine, David J.; Edelstein, Jerry

2003-02-01

90

High-Resolution Broadband Spectral Interferometry  

SciTech Connect

We demonstrate solar spectra from a novel interferometric method for compact broadband high-resolution spectroscopy. The spectral interferometer (SI) is a hybrid instrument that uses a spectrometer to externally disperse the output of a fixed-delay interferometer. It also has been called an externally dispersed interferometer (EDI). The interferometer can be used with linear spectrometers for imaging spectroscopy or with echelle spectrometers for very broad-band coverage. EDI's heterodyning technique enhances the spectrometer's response to high spectral-density features, increasing the effective resolution by factors of several while retaining its bandwidth. The method is extremely robust to instrumental insults such as focal spot size or displacement. The EDI uses no moving parts, such as purely interferometric FTS spectrometers, and can cover a much wider simultaneous bandpass than other internally dispersed interferometers (e.g. HHS or SHS).

Erskine, D J; Edelstein, J

2002-08-09

91

High resolution lunar radar studies: Preliminary results  

NASA Technical Reports Server (NTRS)

High resolution radar data for the lunar surface were acquired over 14 sites in June and November 1990 using the new 10 MHz data taking system at the Arecibo Observatory. The raw data collected for each site covers an area approximately 100 by 400 km and will be processed using delay-Doppler techniques into images of backscatter cross section with three fo four independent looks. All observations transmitted a circularly polarized signal and both senses of circular polarization were received containing the polarized and depolarized component of the backscatter signal. The relative power in these two polarizations provides useful information on properties of the surface, in particular surface roughness. The effort to date focused on the initial data analysis with new software written to perform a full synthetic aperture focusing on the raw radar data. This analysis will involve the use of complementary high resolution optical and topographic data sets to aid interpretation of surface scattering mechanisms.

Stacy, Nicholas J. S.; Campbell, Donald B.

1991-01-01

92

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

93

A METHOD FOR INTRACELLULAR AUTORADIOGRAPHY IN THE ELECTRON MICROSCOPE  

PubMed Central

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 µcurie per ml of thymidine-H3. 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 carbon-stabilized electron microscope grids. A 150 to 450 A layer of silver metal was then evaporated onto the tissue. The coated grids were exposed to bromine vapor for 1.5 to 2 minutes under red light, allowed to dry for 1 minute, and then covered with a thin film of 1 per cent aqueous gelatin applied by means of a fine wire loop lowered over the grid supported on a glass peg. For autoradiographic exposure, the grids were stored 50 days in a light-proof container at 4°C with calcium chloride desiccant. Development was carried out for 5 minutes at 20°C in Promicrol (May and Baker, England) diluted 1:1 with water, followed by a 1 minute water wash and fixation for 2.5 minutes in 15 per cent aqueous sodium thiosulphate. After removal of the gelatin by immersion for 16 hours in water at 37°C, the autoradiograms were dried and examined in the electron microscope. Ultrastructural detail was fairly well defined and the cytoplasm of each labeled cell was covered with an electron opaque deposit of silver, suggesting that a polynucleotide containing thymidine may be synthesized in the cytoplasm. The matter is discussed. PMID:19866594

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

1961-01-01

94

Genotyping by high-resolution melting analysis.  

PubMed

High-resolution melting (HRM) analysis is a simple, closed tube, post-PCR method used to identify genetic variation. The method is highly sensitive and can discriminate DNA sequence variants based on length (such as insertions or deletions), composition (such as single nucleotide polymorphisms, i.e., SNP) or strand complementarity (such as heterozygous or homozygous material). The technique involves PCR amplification of a target sequence in the presence of a fluorescent double-stranded DNA (dsDNA) binding dye, melting of the fluorescent amplicons, and subsequent interpretation of melt curve profiles. Here, we describe general considerations for assay design, PCR amplification, and HRM analysis. PMID:24816659

Tucker, Elise J; Huynh, Bao Lam

2014-01-01

95

High Resolution Laser Spectroscopy of Rhenium Carbide  

NASA Astrophysics Data System (ADS)

The first spectroscopic study of rhenium carbide, ReC, has been performed using both low and high resolution techniques to collect rotationally resolved electronic spectra from 420 to 500nm. Laser-induced fluorescence (LIF), and dispersed fluorescence (DF) techniques were employed. ReC was formed in our laser ablation molecular jet apparatus by ablating a rhenium target rod in the presence of 1% methane in helium. The low resolution spectrum identified four bands of an electronic system belonging to ReC, three of which have been studied so far. Extensive hyperfine structure composed of six hyperfine components was observed in the high resolution spectrum, as well as a clear distinction between the 187ReC and 185ReC isotopologues. The data seems consistent with a ^4? - ^4?- transition, as was predicted before experimentation. Dispersed fluorescence spectra allowed us to determine the ground state vibrational frequency (?e"=994.4 ± 0.3 wn), and to identify a low-lying electronically excited state at Te"=1118.4 ± 0.4 wn with a vibrational frequency of ?e"=984 ± 2 wn. Personal communication, F. Grein, University of New Brunswick

Adam, Allan G.; Hall, Ryan M.; Linton, Colan; Tokaryk, Dennis

2014-06-01

96

A new approach to high resolution FISH  

SciTech Connect

Various gene mapping efforts need high resolution ordering of clones. Using fluorescence in situ hybridization (FISH) best resolution has so far been achieved by the methods where the cells have been lysed and the chromatin has been stretched on the slide. This original DIRVISH method can resolve probes located only a few kilobases apart. We describe here another, novel alternative for high resolution FISH mapping. In this method agarose embedded DNA in form of a pulse field gel block is used as a hybridization target. This target is easy to prepare and available in many laboratories dealing with positional cloning. A small piece of PFGE block is melted on a microscope slide, the DNA is stretched and air-dried. In addition to the technical simplicity of the method it also offers possibilities for pretreatments of the target DNA such as cleavage by rare cutting restriction enzymes. The modification has significantly improved the reproducibility, hybridization efficiency and quality of hybridization signals in the stretched DNA. In practice this method has been applied in positional cloning of genes behind two variants of neuronal lipofuscinosis (INCL, Chr 1p and vINCL, Chr 13q). Here we have successfully ordered YACs, cosmid, phage and plasmid clones on genomic DNA facilitating rapid construction of physical maps of the two areas. DNA released from YAC-blocks has also been used as target for ordering cosmid and phage clones within the YAC.

Heiskanen, M.A.; Karhu, R.; Hellsten, E. [National Public Health Institute, Helsinki (Finland)] [and others

1994-09-01

97

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

98

The SKA and "High-Resolution" Science  

E-print Network

"High-resolution", or "long-baseline", science with the SKA and its precursors covers a broad range of topics in astrophysics. In several research areas, the coupling between improved brightness sensitivity of the SKA and a sub-arcsecond resolution would uncover truly unique avenues and opportunities for studying extreme states of matter, vicinity of compact relativistic objects, and complex processes in astrophysical plasmas. At the same time, long baselines would secure excellent positional and astrometric measurements with the SKA and critically enhance SKA image fidelity at all scales. The latter aspect may also have a substantial impact on the survey speed of the SKA, thus affecting several key science projects of the instrument.

Lobanov, A P

2011-01-01

99

Development of a high resolution and high dispersion Thomson parabola.  

PubMed

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

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

2011-01-01

100

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

101

Transmitter sensitivity of neurons assayed by autoradiography  

SciTech Connect

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

Yoshikami, D.

1981-05-22

102

Sequential High-Resolution Wind Profile Measurements  

NASA Technical Reports Server (NTRS)

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

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

1978-01-01

103

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.

2014-09-14

104

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

105

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.; Rouvière, N.

2006-11-01

106

Limiting liability via high resolution image processing  

SciTech Connect

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, T.K.

1996-12-31

107

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

108

High Resolution Camera for Mapping Titan Surface  

NASA Technical Reports Server (NTRS)

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

Reinhardt, Bianca

2011-01-01

109

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

110

High resolution wavefront measurement of aspheric optics  

NASA Astrophysics Data System (ADS)

With the recently emerged large volume production of miniature aspheric lenses for a wide range of applications, a new fast fully automatic high resolution wavefront measurement instrument has been developed. The Shack-Hartmann based system with reproducibility better than 0.05 waves is able to measure highly aspheric optics and allows for real time comparison with design data. Integrated advanced analysis tools such as calculation of Zernike coefficients, 2D-Modulation Transfer Function (MTF), Point Spread Function (PSF), Strehl-Ratio and the measurement of effective focal length (EFL) as well as flange focal length (FFL) allow for the direct verification of lens properties and can be used in a development as well as in a production environment.

Erichsen, I.; Krey, S.; Heinisch, J.; Ruprecht, A.; Dumitrescu, E.

2008-08-01

111

Analysis of brominated dioxins and furans by high resolution gas chromatography/high resolution mass spectrometry.  

PubMed

This article reviews the available literature on the analysis of brominated dibenzo-p dioxins and furans (PBDD/Fs) by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). Sample extraction and clean up, injection techniques, chromatographic separation, labelled standards and QA/QC works are discussed. Furthermore, full separation of PBDD/Fs from polybrominated diphenyl ethers (PBDEs) during clean up and control of possible chromatographic interference of PBDEs during instrumental analysis as well as possible actions to further enhance the quality of published data are discussed in detail. PMID:18954873

Hagberg, Jessika

2009-01-16

112

Visualizing receptors for neurotransmitters in the human brain with autoradiography.  

PubMed

Receptors for neurotransmitters and drugs are now well characterized at the molecular level. Thanks to the development of numerous radiolabeled molecules and to the use of autoradiography it is possible to study the characteristics and distribution of these receptors with the anatomical resolution of the microscope. We have used quantitative receptor autoradiography to examine receptors in the human brain and to study receptor alterations in neurodegenerative diseases of the human brain. Alterations in the density and distribution of receptors have been found in diseases such as amyothrophic lateral sclerosis, Huntington's Chorea, Parkinson's disease and Alzheimer's disease. In these diseases different types of receptor alterations have been found. The most characteristic ones are selective receptor losses associated with neuronal losses. Alterations such as receptor hypersensitivity due to degeneration of target areas have also been observed. In some cases no correlations between alterations of the neurotransmitters and receptors have been found. These results indicate that different receptors are associated with specific neuronal systems and could be used as markers for these neuronal populations in different pathological studies. The possibility of visualizing receptors in the living human with non-invasive techniques such as PET could lead to the future use of receptor alterations as a diagnostic tool. PMID:2546100

Palacios, J M; Chinaglia, G; Probst, A

1989-01-01

113

High Spatial Resolution MIR Spectroscopy of AGN  

NASA Astrophysics Data System (ADS)

In the classical unified model of Seyfert AGN, the classification as a Seyfert 1 or 2 is dependent on the orientation to the line of sight of an optically and geometrically thick torus surrounding the central engine (i.e. Antonucci & Miller 1985). Detailed observations and models of the spatial extent and SED of the torus are therefore crucial to the advancement of unified models. The torus must intercept a significant fraction of the energy from the central engine, and will re-radiate this energy with the observed emission peaking at mid-infrared (MIR) wavelengths. Thus mid-IR observations of AGN provide a powerful diagnostic of the torus and central activity in AGN. However, recent MIR imaging and spectroscopy of AGN have demonstrated that a significant amount of mid-IR emission is commonly found to be extended around the nucleus and ionization cones, with properties that differ significantly from those of the nucleus. Hence, torus models based on low-spatial resolution (1 arcsec or worse) observations suffer significant contamination which greatly detracts from the validity of those models. To advance these models, we plan to make high spatial resolution spectroscopy of the central regions of 2 bright, nearby AGN and then use new models to account for the observed emission.

Packham, Christopher

2006-08-01

114

The CIBA high resolution RBS facility  

NASA Astrophysics Data System (ADS)

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

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

2006-08-01

115

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

116

High-Resolution Structured Light Range Scanner with Automatic Calibration  

E-print Network

High-Resolution Structured Light Range Scanner with Automatic Calibration ALEXANDER M. BRONSTEIN-cost high-resolution structured light range scanner with automatic calibration, based on temporal stripe-cost high-resolution structured light scanner with automatic calibration. The term structured light refers

Kimmel, Ron

117

High Resolution Infrared Spectroscopy in Astronomy  

Microsoft Academic Search

Infrared Spectroscopy at a resolution of a few km\\/s allows to study rotational-vibrational transitions of many abundant molecules as well as important atomic lines in a multitude of interesting astrophysical environments. The ESO VLT will shortly be equipped with two unique infrared spectrometers which combine spectral resolution with spatial resolutions of = 0.2 arcsec:

H. U. Käufl; A. Moorwood

2003-01-01

118

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

119

Limits of simulation based high resolution EBSD.  

PubMed

High resolution electron backscattered diffraction (HREBSD) is a novel technique for a relative determination of both orientation and stress state in crystals through digital image correlation techniques. Recent works have tried to use simulated EBSD patterns as reference patterns to achieve the absolute orientation and stress state of crystals. However, a precise calibration of the pattern centre location is needed to avoid the occurrence of phantom stresses. A careful analysis of the projective transformation involved in the formation of EBSD patterns has permitted to understand these phantom stresses. This geometrical analysis has been confirmed by numerical simulations. The results indicate that certain combinations of crystal strain states and sample locations (pattern centre locations) lead to virtually identical EBSD patterns. This ambiguity makes the problem of solving the absolute stress state of a crystal unfeasible in a single-detector configuration. PMID:23676453

Alkorta, Jon

2013-08-01

120

Optical High Resolution Spectra of APOGEE Stars  

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

121

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 1×1 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.

Bräuer-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

122

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

123

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

124

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

125

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

126

HDIR: very high resolution thermal imager  

NASA Astrophysics Data System (ADS)

The High-Definition InfraRed (HDIR) thermal-imaging system is a thermal camera with highest geometrical resolution producing a video signal according to the HDTV (High- Definition TeleVision) standard. The thermal-imaging system is a parallel-scanning device with two fold interlace. Its detector is sensitive within the 7-11 micrometers spectral region and features 576 x n elements (n being the number of TDI stages). It has been carefully optimized in terms of range performance and size of optical entrance pupil as well as feasibility of production and yield. The 16:9 aspect ratio of the HDTV standard together with the high number of 1920 pixels/line and 1152 lines propose a drastic increase in range performance. In fact, model calculations predict an increase of up to 60% for identification range as compared to present-standard TV-compatible thermal imagers with the same vertical field of view. With the HDIR having been integrated into a German main battle tank Leopard 2, trials were undertaken in comparison with other equipment like the OPHELIOS and the Common Module WBG-X.

Duchateau, Ruediger; Hoefft, Jens-Rainer; Kuerbitz, Gunther; Wieland, Hans-Ulrich

2000-12-01

127

High Resolution Spectroscopic Study of Abell 78  

NASA Astrophysics Data System (ADS)

High resolution spectroscopic data of the central knots and the outer shell of the planetary nebula Abell 78 are analyzed. Chemical abundances and kinematics were derived for each region. The inner knots appear to be denser and slightly cooler than the outer shell, and they are constituted by an extremely H-deficient material. These knots are receding from the central star with velocities in the range from +40 to -60 km s-1 and present cometary structures probably caused by the stellar wind. The outer shell appears to have very low metallicity but we conclude that abundance determinations are probably affected by large temperature fluctuations in the gas, caused by additional heating mechanisms such as shocks by high speed ejecta and photo-electrons from dust grains, etc. Our kinematical analysis clearly demonstrates that H lines are not emitted in the inner knots but in the outer shell. In the outer zone we have detected a high-velocity compact structure, with velocities from -40 to 90 km s-1. This spike emits in collisionally excited lines (mainly [O III]), but it is not detected in H or He lines. Therefore, it should consist of a ``bullet'' of H-deficient material that is colliding with the outer shell.

Medina, S.; Peña, M.

2000-10-01

128

The use of electronic autoradiography in radiopharmacy.  

PubMed

The use of Microchannel Plate Analysers (Instant Imager, Canberra Packard), the so called Electronic Autoradiography, in Radiopharmacy is described. The system can be used for quality control of radiopharmaceuticals as well as for scientific research purposes. Quantitative analysis of 2-dimensional radioactive samples of all radionuclides used in Nuclear Medicine (especially 99mTc) can be performed in a very short time with little effort. Advantages and limitations for radiopharmaceutical work are described. PMID:9257336

Decristoforo, C; Zaknun, J; Kohler, B; Oberladstaetter, M; Riccabona, G

1997-05-01

129

A method for generating high resolution satellite image time series  

NASA Astrophysics Data System (ADS)

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

Guo, Tao

2014-10-01

130

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

131

High resolution electron attachment to CO? clusters.  

PubMed

Electron attachment to CO? clusters performed at high energy resolution (0.1 eV) is studied for the first time in the extended electron energy range from threshold (0 eV) to about 10 eV. Dissociative electron attachment (DEA) to single molecules yields O(-) as the only fragment ion arising from the well known (2)?(u) shape resonance (ion yield centered at 4.4 eV) and a core excited resonance (at 8.2 eV). On proceeding to CO? clusters, non-dissociated complexes of the form (CO?)(n)(-) including the monomer CO?(-) are generated as well as solvated fragment ions of the form (CO?)(n)O(-). The non-decomposed complexes appear already within a resonant feature near threshold (0 eV) and also within a broad contribution between 1 and 4 eV which is composed of two resonances observed for example for (CO?)(4)(-) at 2.2 eV and 3.1 eV (peak maxima). While the complexes observed around 3.1 eV are generated via the (2)?(u) resonance as precursor with subsequent intracluster relaxation, the contribution around 2.2 eV can be associated with a resonant scattering feature, recently discovered in single CO? in the selective excitation of the higher energy member of the well known Fermi dyad [M. Allan, Phys. Rev. Lett., 2001, 87, 0332012]. Formation of (CO?)(n)(-) in the threshold region involves vibrational Feshbach resonances (VFRs) as previously discovered via an ultrahigh resolution (1 meV) laser photoelectron attachment method [E. Leber, S. Barsotti, I. I. Fabrikant, J. M. Weber, M.-W. Ruf and H. Hotop, Eur. Phys. J. D, 2000, 12, 125]. The complexes (CO?)(n)O(-) clearly arise from DEA at an individual molecule within the cluster involving both the (2)?(u) and the core excited resonance. PMID:21491691

Denifl, Stephan; Vizcaino, Violaine; Märk, Tilmann D; Illenberger, Eugen; Scheier, Paul

2010-01-01

132

High resolution rainfall measurements around a high rise building  

NASA Astrophysics Data System (ADS)

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 to two to four times the height of any nearby obstruction to obtain a measurement that is representative for the surrounding area. In an urban area it is almost impossible to find a location that suits this recommendation. Rain measurements in urban area with a high spatial resolution are desired, to obtain a better understanding of urban hydrology, but costs may be prohibitive. A low cost disdrometer has been developed to make it affordable to perform rain measurements with a very high spatial and temporal resolution. The disdrometer is tested around a high rise building on the Delft University of Technology campus. The faculty of Electrical Engineering, Mathematics and Computer Science (EWI) on the campus of Delft University of Technology consists of a high rise building of 90 meters and a low rise building of 15 meters. Sensors are placed on the low rise building to measure the impact of the high rise building on the spatial distribution of precipitation. In addition to the disdrometer, two other methods are used to measure precipitation differences around the high rise building. Tipping bucket rain gauges have been placed on two elevator shaft housings on the low rise building, of which one is situated in the shadow of the high rise building. Simultaneously, runoff from the elevator shafts is measured. A comparison of the different methods will be presented.

de Jong, Stijn; van de Giesen, Nick; Hut, Rolf

2010-05-01

133

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

134

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

135

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

Microsoft Academic Search

A feasibility study for a high resolution positron emission tomograph, based on 9.5×4×4 mm3 LSO crystals viewed by 3 mm diameter avalanche photodiodes, has been carried out. Using a Na22 source we 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

C. Schmelz; S. M. Bradbury; I. Holl; E. Lorenz; D. Renker; S. Ziegler

1995-01-01

136

High-resolution colorimetric imaging of paintings  

Microsoft Academic Search

With the aim of providing a digital electronic replacement for conventional photography of paintings, a scanner has been constructed based on a 3000 X 2300 pel resolution camera which is moved precisely over a 1 meter square area. Successive patches are assembled to form a mosaic which covers the whole area at c. 20 pels\\/mm resolution, which is sufficient to

Kirk Martinez; John Cupitt; David R. Saunders

1993-01-01

137

The High Time Resolution Radio Sky  

NASA Astrophysics Data System (ADS)

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

Thornton, D.

2013-11-01

138

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

139

Holographic high-resolution endoscopic image recording  

NASA Astrophysics Data System (ADS)

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

Bjelkhagen, Hans I.

1991-03-01

140

High-resolution imaging using endoscopic holography  

NASA Astrophysics Data System (ADS)

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

Bjelkhagen, Hans I.

1990-08-01

141

High resolution scanning electron microscopy of plasmodesmata.  

PubMed

Symplastic transport occurs between neighbouring plant cells through functionally and structurally dynamic channels called plasmodesmata (PD). Relatively little is known about the composition of PD or the mechanisms that facilitate molecular transport into neighbouring cells. While transmission electron microscopy (TEM) provides 2-dimensional information about the structural components of PD, 3-dimensional information is difficult to extract from ultrathin sections. This study has exploited high-resolution scanning electron microscopy (HRSEM) to reveal the 3-dimensional morphology of PD in the cell walls of algae, ferns and higher plants. Varied patterns of PD were observed in the walls, ranging from uniformly distributed individual PD to discrete clusters. Occasionally the thick walls of the giant alga Chara were fractured, revealing the surface morphology of PD within. External structures such as spokes, spirals and mesh were observed surrounding the PD. Enzymatic digestions of cell wall components indicate that cellulose or pectin either compose or stabilise the extracellular spokes. Occasionally, the PD were fractured open and desmotubule-like structures and other particles were observed in their central regions. Our observations add weight to the argument that Chara PD contain desmotubules and are morphologically similar to higher plant PD. PMID:21626150

Brecknock, Sarah; Dibbayawan, Teresa P; Vesk, Maret; Vesk, Peter A; Faulkner, Christine; Barton, Deborah A; Overall, Robyn L

2011-10-01

142

High vertical resolution crosswell seismic imaging  

DOEpatents

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

Lazaratos, Spyridon K. (Houston, TX)

1999-12-07

143

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.

Koike, Masako (Moraga, CA)

1996-01-01

144

High-resolution ophthalmic imaging system  

DOEpatents

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

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

2007-12-04

145

Fundamental constants and high-resolution spectroscopy  

NASA Astrophysics Data System (ADS)

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

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

2014-01-01

146

High resolution fire risk mapping in Italy  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

147

High Resolution Pulse Compression Imaging Using Super Resolution FM-Chirp Correlation Method (SCM)  

NASA Astrophysics Data System (ADS)

This study addresses the issue of the super-resolution pulse compression technique (PCT) for ultrasound imaging. Time resolution of multiple ultrasonic echoes using the FM-Chirp PCT is limited by the bandwidth of the sweep-frequency. That is, the resolution depends on the sharpness of auto-correlation function. We propose the Super resolution FM-Chirp correlation Method (SCM) and evaluate its performance. This method is based on the multiple signal classification (MUSIC) algorithm. Our simulations were made for the model assuming multiple signals reflected from some scatterers. We confirmed that SCM detects time delay of complicated reflected signals successfully with high resolution.

Fujiwara, M.; Okubo, K.; Tagawa, N.

148

Ultra High Resolution Rain Retrieval from QuikSCAT Data  

E-print Network

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

Long, David G.

149

MULTIPULSE - high resolution and high power in one TDEM system  

NASA Astrophysics Data System (ADS)

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

Chen, Tianyou; Hodges, Greg; Miles, Philip

2015-09-01

150

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

SciTech Connect

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

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

2000-01-01

151

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

152

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

153

High Resolution Velocity Structure in Eastern Turkey  

NASA Astrophysics Data System (ADS)

We investigate the crust and upper mantle structure of eastern Turkey where the Anatolian, Arabian and Eurasian Plates meet, forming a complex tectonic regime. 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) provide a unique opportunity for studying the high resolution velocity structure of the region. Zor et al. (2003) found an average 46 km thick crust in the Anatolian plateau using a 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 functions alone, however, may result in an apparent depth-velocity trade-off [Ammon et al., 1990]. In order to improve upon this velocity model, we have combined the receiver functions with surface wave data using the joint inversion method of Julia et al. (2000). In this technique, the two sets of observations are combined into a single algebraic equation and each data set is weighted by an estimate of the uncertainty in the observations. The receiver functions are calculated using an iterative time-domain deconvolution technique. We also consider azimuthal changes in the receiver functions and have stacked them into different groups accordingly. We are improving our surface wave model by making Love and Rayleigh dispersion measurements at the ETSE stations and incorporating them into a regional group velocity model for periods between 10 and 100 seconds. Preliminary results indicate a strong trend in the long period group velocities toward the northeast, indicating slow upper mantle velocities in the area consistent with Pn, Sn and receiver function results. Starting models used for the joint inversions include both a 1-D model from a 12-ton dam shot recorded by ETSE [Gurbuz et al., 2004] and the models from the original receiver function inversions. We observe that the joint inversion results are independent of the starting model and converge to the same final model, with some differences compared to the original profiles. While we don't observe significant changes in the first order discontinuities of the model, such as Moho depth, we are better able to resolve features in the crust.

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

2004-12-01

154

The measurement of grain boundary diffusion by the method of autoradiography  

Microsoft Academic Search

The method of autoradiography is used in the quantitative measurement of grain boundary diffusion. The autoradiographic image is examined using the Joyce-Loebl isodensitracer to produce an accurate two-dimensional density map of the grain boundary region sufficient in detail to allow a more extensive analysis of grain boundary diffusion. Tracer diffusion of the very high, medium and very low energy isotopes

T. J. Renouf

1970-01-01

155

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

156

High-resolution electrohydrodynamic jet printing  

Microsoft Academic Search

Efforts to adapt and extend graphic arts printing techniques for demanding device applications in electronics, biotechnology and microelectromechanical systems have grown rapidly in recent years. Here, we describe the use of electrohydrodynamically induced fluid flows through fine microcapillary nozzles for jet printing of patterns and functional devices with submicrometre resolution. Key aspects of the physics of this approach, which has

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

2007-01-01

157

The High Resolution Fly's Eye (hires) Project  

Microsoft Academic Search

At the present time, the origin of cosmic rays in the EH E region ( Energy > 10 18 eV ) remains uncertain. The major limitation to progress in determination of the source of these particles is the low event statistics and poor directional, energy, and primary composition resolution of present cosmic ray observatories in this energy range. We describe

P. Sokolsky; J. Boyer; R. W. Clay; S. C. Corbató; H. Y. Dai; B. R. Dawson; R. W. Downing; J. W. Elbert; M. A. Huang; D. B. Kidd; D. B. Kieda; S. Ko; C. G. Larsen; W. Lee; E. C. Loh; E. Mannel; T. A. O'Halloran; M. H. Salamon; J. D. Smith; P. Sommers; J. K. K. Tang; S. B. Thomas

1997-01-01

158

High resolution SAR applications and instrument design  

Microsoft Academic Search

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

C. Dionisio; A. Torre

1993-01-01

159

The High Resolution Microwave Cavity Search for Dark Matter Axions  

NASA Astrophysics Data System (ADS)

The Axion Dark Matter eXperiment (ADMX) has recently added a high resolution channel in ongoing efforts to detect axions in our galactic halo. This channel is designed to observe the signal from discrete flows of dark matter near Earth, in addition to the thermal spectrum, which is observable by the experiment's medium resolution channel. After briefly reviewing the properties of dark matter axions, I describe ADMX and present results from the high resolution channel.

Duffy, Leanne

2005-04-01

160

OBJECTIVE SYNOPTIC CLASSIFICATION COMBINED WITH HIGH RESOLUTION METEOROLOGICAL MODELS FOR  

E-print Network

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

Politècnica de Catalunya, Universitat

161

Advances in turbulent flow computations using high-resolution methods  

Microsoft Academic Search

The paper reviews research activity in connection with the use of high-resolution methods in turbulent flow computations. High-resolution methods have proven to successfully compute a number of turbulent flows without need to resort to an explicit turbulence model. Here, we review the basic properties of these methods, present evidence from the successful implementation of these methods in turbulent flows, and

Dimitris Drikakis

2003-01-01

162

Adaptive optics with pupil tracking for high resolution retinal imaging  

E-print Network

for high resolution retinal imaging because eye movements constitute an important part of the ocular of Ireland, Galway, Ireland 2Imagine Eyes, 18 Rue Charles de Gaulle, 91400, Orsay, France betulhn ocular aberrations in real time and results in improved high resolution images that reveal

Dainty, Chris

163

Novel radiation hard microfabricated scintillation detectors with high spatial resolution  

E-print Network

Novel radiation hard microfabricated scintillation detectors with high spatial resolution A, Switzerland a r t i c l e i n f o Available online 4 July 2009 Keywords: Scintillation detectors Microfabrication Microfluidics a b s t r a c t A novel liquid scintillation detector with high spatial resolution

Dalang, Robert C.

164

High-resolution ground-based spectroscopy: where and how ?  

NASA Astrophysics Data System (ADS)

An overview is presented of high-resolution optical spectrographs in operation or under development at large telescopes, with emphasis on those facilities best suited for the study of late-type stars and stellar surface inhomogeneities. Plans for the development of new high-resolution spectroscopic instruments are discussed with emphasis on the ICE spectrograph for the PEPSI spectropolarimeter at the LBT.

Pallavicini, R.

2002-07-01

165

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

166

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

167

HIGH RESOLUTION PHOTOEMISSION STUDIES OF COMPLEX MATERIALS.  

SciTech Connect

Recent instrumentation developments in photoemission are providing new insights into the physics of complex materials. With increased energy and momentum resolution, it has become possible to examine in detail different contributions to the self-energy or inverse lifetime of the photohole created in the photoexcitation process. Employing momentum distribution and energy distribution curves, a detailed study of the optimally doped cuprate, Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}}, shows that the material behaves like a non-Fermi liquid with no evidence for the quasi-particles characteristic of a Fermi liquid.

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

1999-10-13

168

DSCOVR High Time Resolution Solar Wind Measurements  

NASA Technical Reports Server (NTRS)

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

Szabo, Adam

2012-01-01

169

DSCOVR High Time Resolution Solar Wind Measurements  

NASA Astrophysics Data System (ADS)

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

Szabo, A.

2012-12-01

170

HIGH RESOLUTION PHOTOEMISSION STUDIES OF COMPLEX MATERIALS.  

SciTech Connect

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

JOHNSON,P.D.

1999-10-13

171

High resolution obtained by photoelectric scanning techniques.  

NASA Technical Reports Server (NTRS)

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

Hall, J. S.

1972-01-01

172

High Resolution Chemical Study of ALH84001  

NASA Technical Reports Server (NTRS)

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

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

2001-01-01

173

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

174

An improved IHS fusion for high resolution remote sensing images  

NASA Astrophysics Data System (ADS)

Image fusion plays an important role in improving high resolution remote sensing images, as many Earth observation satellites provide both high-resolution panchromatic and multispectral images. To date, many image fusion techniques have been developed. Existing traditional image fusion techniques such as the intensity-hue-saturation (IHS) transform, wavelet transform and principal components analysis(PCA) methods may not be optimal for fusing the new generation commercial high-resolution satellite images such as IKONOS and Quick Bird. However, the available algorithms can hardly meet a satisfactory fusion requirement for high resolution remote sensing images. Among the existing fusion algorithms, the IHS technique is the most widely used one technique. But the color distortion of this technique is often obvious, especially when high resolution multispectral images are fused with its panchromatic images. This study presents a new fusion approach that integrates both IHS and histogram match techniques to reduce the color distortion of high resolution remote sensing fusion results. Different high resolution remote sensing images have been fused with this new approach. The result proves that the concept of the proposed improved IHS is promising, and it does significantly improve the fusion quality compared to conventional IHS transform fusion techniques.

Hu, Youjian; Zhang, Xiaohua

2010-02-01

175

High resolution airborne geophysics at hazardous waste disposal sites  

SciTech Connect

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

Beard, L.P.; Nyquist, J.E.; Doll, W.E. [Oak Ridge National Lab., TN (United States); Chong Foo, M.; Gamey, T.J. [Aerodat, Inc., Mississauga, Ontario (Canada)

1995-06-01

176

Wide-field, high-resolution Fourier ptychographic microscopy.  

PubMed

In this article, we report an imaging method, termed Fourier ptychographic microscopy (FPM), which iteratively stitches together a number of variably illuminated, low-resolution intensity images in Fourier space to produce a wide-field, high-resolution complex sample image. By adopting a wavefront correction strategy, the FPM method can also correct for aberrations and digitally extend a microscope's depth-of-focus beyond the physical limitations of its optics. As a demonstration, we built a microscope prototype with a resolution of 0.78 ?m, a field-of-view of ~120 mm(2), and a resolution-invariant depth-of-focus of 0.3 mm (characterized at 632 nm). Gigapixel colour images of histology slides verify FPM's successful operation. The reported imaging procedure transforms the general challenge of high-throughput, high-resolution microscopy from one that is coupled to the physical limitations of the system's optics to one that is solvable through computation. PMID:25243016

Zheng, Guoan; Horstmeyer, Roarke; Yang, Changhuei

2013-09-01

177

Wide-field, high-resolution Fourier ptychographic microscopy  

NASA Astrophysics Data System (ADS)

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

Zheng, Guoan; Horstmeyer, Roarke; Yang, Changhuei

2013-09-01

178

Robust Tips for High Resolution Chemical Imaging  

NASA Astrophysics Data System (ADS)

Tip enhanced Raman spectroscopy (TERS) combines scanning probe microscopy with Raman spectroscopy, taking advantage of apertureless near-field optics. A plasmonic structure at the apex of a sharp tip provides signal amplification required for chemical imaging. Plasmonic structure characteristics such as roughness, shape, and radius determine the spatial resolution and signal enhancement. Unfortunately, noble metal nanostructures have limited lifetimes due to mechanical, chemical, and thermal degradation. Lifetime extension requires slowing degradation processes while minimizing unfavorable influences on the optical response. An ultrathin SiOx protective coating provides lifetime improvement of silver plasmonic nanostructures on SPM tips. Controlled physical vapor deposition (PVD) of Al can be used to create ultrathin (˜2-3 nm) Al2O3 coatings that improve significantly the stability and wear resistance of plasmonics structures without substantial degradation of optical properties. Such a coating completely prevented decay in plasmonic activity after 40 days of use.

Barrios, Carlos; Malkovskiy, Andrey; Kisliuk, Alexander; Sokolov, Alexei; Foster, Mark

2009-03-01

179

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

180

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 (Dürr et al., 2005; Gleeson et al., 2010; Hartmann and Moosdorf, 2013) combined with information about e.g. aquifer thickness and presence of less permeable, impermeable, and semi-impermeable layers. For the parameterization, we relied entirely on available global datasets and did not calibrate the model so that it can equally be expanded to data poor environments. We forced the groundwater model with the output from the global hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the net groundwater recharge and average surface water levels derived from routed channel discharge. We validated simulated groundwater heads with observations, from North America and Australia, resulting in a coefficient of determination of 0.8 and 0.7 respectively. This shows that it is feasible to build a global groundwater model using best available global information, and estimated water table depths are within acceptable accuracy in many parts of the world.

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

2013-12-01

181

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.

Cash, Webster

2002-01-01

182

Micro-Resonator-Array for high-resolution spectroscopy  

Microsoft Academic Search

Summary form only given. In this paper we show that a comparable spectral resolution can be achieved using an array of spherical or nearly spherical dielectric microresonators arranged on a flat light guide. Recently, high resolution spectroscopic devices were developed in the millimeter or micrometer size rang. Basically, three types of instruments are available: scanning Fabry-Perot (SFP) interferometer, grating spectrometer

G. Schweiger; R. Nett

2007-01-01

183

High-resolution neutron microtomography with noiseless neutron counting detector  

Microsoft Academic Search

The improved collimation and intensity of thermal and cold neutron beamlines combined with recent advances in neutron imaging devices enable high-resolution neutron radiography and microtomography, which can provide information on the internal structure of objects not achievable with conventional X-ray imaging techniques. Neutron detection efficiency, spatial and temporal resolution (important for the studies of dynamic processes) and low background count

A. S. Tremsin; J. B. McPhate; J. V. Vallerga; O. H. W. Siegmund; W. B. Feller; E. Lehmann; L. G. Butler; M. Dawson

2011-01-01

184

High resolution data base for use with MAP  

SciTech Connect

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

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

1987-05-05

185

High-Resolution Fluorometer for Mapping Microscale Phytoplankton Distributions  

PubMed Central

A new high-resolution, in situ profiling fluorometer maps fluorescence distributions with a spatial resolution of 0.5 to 1.5 mm to a depth of 70 m in the open ocean. We report centimeter-scale patterns for phytoplankton distributions associated with gradients exhibiting 10- to 30-fold changes in fluorescence in contrasting marine ecosystems. PMID:16751572

Doubell, Mark J.; Seuront, Laurent; Seymour, Justin R.; Patten, Nicole L.; Mitchell, James G.

2006-01-01

186

Mapping cognitive brain function with modern high-resolution electroencephalography  

Microsoft Academic Search

High temporal resolution is necessary to resolve the rapidly changing patterns of brain activity that underlie mental function. While electroencephalography (EEG) provides temporal resolution in the millisecond range, which would seem to make it an ideal complement to other imaging modalities, traditional EEG technology and practice provides insufficient spatial detail to identify relationships between brain electrical events and structures and

Alan Gevins; Harrison Leong; Michael E. Smith; Jian Le; Robert Du

1995-01-01

187

Sensitivity of urban hydrodynamic modelling to high resolution radar rainfall  

NASA Astrophysics Data System (ADS)

Since the early 90's, the need to improve the spatial and temporal resolution of rainfall estimates has been emphasised. Urban hydrological applications require high resolution rainfall inputs matching rapid response times of such catchments. With the advent of new radar technology, urban hydrologists nowadays have access to highly accurate rainfall estimates to drive their models. High resolution rainfall products are provided by dual polarimetric X-band radars, which retrieve rainfall rates at 1 min temporal resolution and 30 m spatial resolution. This study attempts to characterise sensitivity of hydrologic response to high resolution weather radar rainfall input for hydrodynamic models at urban scale. Spatial resolutions of both rainfall input and hydrologic units are of the order of 100 meters. Rainfall rates derived from X-band polarimetric weather radar are used as input into a detailed hydrodynamic sewer model for an urban catchment in Rotterdam, The Netherlands. Rainfall data of two storms, one convective and one stratiform, at different spatial resolutions, are used to analyse the effect of precipitation data resolution on simulated in-sewer water levels as well as runoff peaks. Dimensionless parameters are derived to analyse the effect of rainfall resolution in relation to storm and catchment properties. Simulation results are first analysed in relation to 'storm redistribution' induced by spatial precipitation sampling: storm correlation distance is compared to rainfall resolution and the effect on hydrodynamic model results is discussed. Sensitivity of hydrodynamic model results to storm redistribution will be discussed for varying positions throughout the catchment and dependent on localisation of convective storm cells.

Bruni, Guendalina; Reinoso, Ricardo; van de Giesen, Nick; Clemens, Francois; ten Veldhuis, Marie-Claire

2014-05-01

188

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

189

Towards high-resolution mantle convection simulations  

NASA Astrophysics Data System (ADS)

The motion of tectonic plates at the Earth’s surface, earthquakes, most forms of volcanism, the growth and evolution of continents, and the volatile fluxes that govern the composition and evolution of the oceans and atmosphere are all controlled by the process of solid-state thermal convection in the Earth’s rocky mantle, with perhaps a minor contribution from convection in the iron core. Similar processes govern the evolution of other planetary objects such as Mars, Venus, Titan, and Europa, all of which might conceivably shed light on the origin and evolution of life on Earth. Modeling and understanding this complicated dynamical system is one of the true “grand challenges” of Earth and planetary science. In the past three decades much progress towards understanding the dynamics of mantle convection has been made, with the increasing aid of computational modeling. Numerical sophistication has evolved significantly, and a small number of independent codes have been successfully employed. Computational power continues to increase dramatically, and with it the ability to resolve increasingly finer fluid mechanical structures. Yet, the perhaps most often cited limitation in numerical modeling based publications is still the limitation of computing power, because the ability to resolve thermal boundary layers within the convecting mantle (e.g., lithospheric plates), requires a spatial resolution of ~ 10 km. At present, the largest supercomputing facilities still barely approach the power to resolve this length scale in mantle convection simulations that include the physics necessary to model plate-like behavior. Our goal is to use supercomputing facilities to perform 3D spherical mantle convection simulations that include the ingredients for plate-like behavior, i.e. strongly temperature- and stress-dependent viscosity, at Earth-like convective vigor with a global resolution of order 10 km. In order to qualify to use such facilities, it is also necessary to demonstrate good parallel efficiency. Here we will present two kinds of results: (1) scaling properties of the community code CitcomS on DOE/NERSC's supercomputer Franklin for up to ~ 6000 processors, and (2) preliminary simulations that illustrate the role of a low-viscosity asthenosphere in plate-like behavior in mantle convection.

Höink, T.; Richards, M. A.; Lenardic, A.

2009-12-01

190

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 (Dürr et al., 2005; Gleeson et al., 2010; Hartmann and Moosdorf, 2013), combined with our estimate of aquifer thickness for sedimentary basins. We forced the groundwater model with the output from the global hydrological model PCR-GLOBWB (van Beek et al., 2011), specifically the net groundwater recharge and average surface water levels derived from routed channel discharge. For the parameterization, we relied entirely on available global datasets and did not calibrate the model so that it can equally be expanded to data poor environments. Based on our sensitivity analysis, in which we run the model with various hydrogeological parameter settings, we observed that most variance in groundwater 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

191

Ultra-high resolution and high-brightness AMOLED  

NASA Astrophysics Data System (ADS)

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

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

2012-06-01

192

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.

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

2008-08-01

193

A comparative autoradiography study in post mortem whole hemisphere human brain slices taken from Alzheimer patients and age-matched controls using two radiolabelled DAA1106 analogues with high affinity to the peripheral benzodiazepine receptor (PBR) system  

Microsoft Academic Search

The binding of two radiolabelled analogues (N-(5-[125I]Iodo-2-phenoxyphenyl)-N-(2,5-dimethoxybenzyl)acetamide ([125I]desfluoro-DAA1106) and N-(5-[125I]Fluoro-2-phenoxyphenyl)-N-(2-[125I]Iodo-5-methoxybenzyl)acetamide ([125I]desmethoxy-DAA1106) of the peripheral benzodiazepine receptor (PBR) (or TSPO, 18kDa translocator protein) ligand DAA1106 was examined by in vitro autoradiography on human post mortem whole hemisphere brain slices obtained from Alzheimer's disease (AD) patients and age-matched controls. Both [125I]desfluoro-IDAA1106 and [125I]desmethoxy-IDAA1106 were effectively binding to various brain structures. The binding

Balázs Gulyás; Boglárka Makkai; Péter Kása; Károly Gulya; Lidia Bakota; Szilvia Várszegi; Zsuzsa Beliczai; Jan Andersson; László Csiba; Andrea Thiele; Thomas Dyrks; Tetsua Suhara; Kazutoshi Suzuki; Makato Higuchi; Christer Halldin

2009-01-01

194

High Resolution CryoFESEM of Microbial Surfaces  

NASA Astrophysics Data System (ADS)

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

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

2003-08-01

195

High resolution difference schemes for compressible gas dynamics  

SciTech Connect

The advantages and disadvantages of four new high-resolution difference schemes, namely the von Neumann-Richtmyer, Godunovs, MUSCL and Glimms, for mathematically representing physical conditions in compressible gas flows are compared. (LCL)

Woodward, P.; Colella, P.

1980-07-30

196

Fluorinated diamondlike carbon templates for high resolution nanoimprint lithography  

E-print Network

Fluorinated diamondlike carbon templates for high resolution nanoimprint lithography M. Schvartzman was found to form a Teflon-like thin layer on the treated DLC surface. The fluorinated templates were used

Hone, James

197

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

198

AVHRR/1-FM Advanced Very High Resolution Radiometer  

NASA Technical Reports Server (NTRS)

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

1979-01-01

199

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.

200

A high resolution SPECT detector based on thin continuous LYSO.  

PubMed

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

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

2014-01-01

201

Lithography High-Resolution Soft Lithography: Enabling  

E-print Network

-molding in capilla- ries (MIMIC), and microcontact printing (MCP), and 2) rigid imprint techniques (NIL).[8] Polydimethylsiloxane (PDMS) [*] J. P. Rolland, G. M. Denison, Prof. J. M. De Simone, such as PDMS, offers numerous attractive properties in several lithographic techniques. PDMS is highly UV

Carter, Kenneth

202

Performance characteristics of high resolution Compton telescopes  

NASA Astrophysics Data System (ADS)

To build upon the goals of the upcoming INTEGRAL mission, the next generation soft gamma -ray (0.2-20 MeV) observatory will require improved sensitivity to continuum and nuclear line emission, while maintaining high spectroscopy to resolve Doppler shifts and broadenings. We present the simulated performance of two germanium Compton telescope (GCT) designs in high Earth orbit conditions. The goal of this work is both to determine realistic sensitivities for the GCTs, as well as determine the geometry which best takes advantage of the spectral, imaging, and stopping power of germanium detectors. We find that a novel Compact design optimizes the sensitivity to both nuclear line and continuum sources, with an effective factor of 2.0 improvement over a Classical design. The Compact GCT would provide an order of magnitude improvement in sensitivity over INTEGRAL.

Boggs, S. E.; Jean, P.

2001-09-01

203

High resolution angular studies of layered superconductors  

NASA Astrophysics Data System (ADS)

Torque and magnetotransport measurements on single crystals of several high Tc superconductors reveal new effects which appear when a magnetic field is applied very close to the layer direction. In the flux-motion resistance, a local maximum is observed, centered at ?=90°, where ? is the angle between the applied field and the c-axis. This resistance peak has an angular width of about 0.03° in TlBa2Ca2Cu3Ox and 0.30° in Bi2Sr2CaCu2Ox, and is highly nonlinear with applied current. This result is at odds with all previous reports of resistance anisotropy in the mixed state of the high Tc materials, where only an overall resistance minimum at the parallel orientation was observed. We suggest a possible mechanism for the new resistance peak: an instability in the vortex lattice at zero tilt angle resulting in the random flipping of vortex ``pancakes,'' from the ±c to the ?c directions, producing additional flux motion and dissipation. In the torque, a deviation is observed from that expected for an anisotropic, 3D superconductor in the same angular range as the resistance peak. This deviation, seen in TlBa2Ca2Cu3Ox and Tl2Ba2CaCu2Ox crystals, is similar in appearance to a prediction by Feinberg of a torque enhancement near the parallel orientation arising from the locking-in of the vortices along the layer direction.

Chung, O. H.; Chaparala, M.; Naughton, M. J.

1992-02-01

204

A high resolution multimode synthetic aperture radar  

NASA Astrophysics Data System (ADS)

Modifications to a high performance synthetic aperture mode for the AN/APS-506 radar are described. The modifications include improvements in the system coherency, the addition of demodulation and digitization circuitry, the installment of a strapdown inertial sensing system on the antenna, and the development of the real time motion compensation and airborne SAR processing subsystems. In the modified version of the radar pulse compression waveform generation is based on a digital waveform scheme that makes it possible to enhance the spectral purity of the radar signals and to obtain a great deal of flexibility in generating waveforms of various bandwidths.

Haslam, G. E.; vant, M. R.; Difilippo, D.

205

HIGH RESOLUTION ANALOG / DIGITAL POWER SUPPLY CONTROLLER  

SciTech Connect

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

Medvedko, Evgeny A

2003-05-21

206

R.: Guide shapes for high resolution naturalistic liquid simulation  

E-print Network

A boat emerges from water. (a) Adequate depth is needed for the desired large-scale disturbances. (b) We compute a guide shape from the finalized coarse solve to capture the deep motion. (c) The guide shape constrains a high resolution simulation of a thin outer shell of liquid to keep the same look. (d) A high resolution simulation in shallow water fails to capture the large-scale motion. Art direction of high resolution naturalistic liquid simulations is notoriously hard, due to both the chaotic nature of the physics and the computational resources required. Resimulating a scene at higher resolution often produces very different results, and is too expensive to allow many design cycles. We present a method of constraining or guiding a high resolution liquid simulation to stay close to a finalized low resolution version (either simulated or directly animated), restricting the solve to a thin outer shell of liquid around a guide shape. Our method is generally faster than an unconstrained simulation and can be integrated with a standard fluid simulator. We demonstrate several applications, with both simulated and handanimated inputs.

Michael B. Nielsen; Robert Bridson

207

[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

208

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

209

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

210

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

211

A Procedure for High Resolution Satellite Imagery Quality Assessment  

PubMed Central

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

212

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

213

Organosilicate Materials for High Resolution Patterning  

NASA Astrophysics Data System (ADS)

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

Christopher, Soles

2010-03-01

214

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.

Schütz, Oliver

2005-02-01

215

A Pipeline for High Resolution Radio Images  

NASA Astrophysics Data System (ADS)

The VLBA Calibrator Survey (VCS) is a database of ~2200 extragalactic radio sources evenly distributed on the sky between declinations of -40 and +90 degrees. In addition to providing a list of potential phase and bandpass calibrators for science observations, the very high astrometric accuracy of the VCS has also proven enormously useful in establishing and refining the International Celestial Reference Frame (ICRF). Using the VLBA at 2.3 and 8.4 GHz, we have recently begun a new epoch of snapshot observations of ~2400 compact VCS sources. Here, we present the preliminary results of a project, conducted with the Common Astronomy Software Applications package (CASA), to design and implement an imaging pipeline for these observations . This pipeline provides images of the sources that are useful for determining their quality as VLBA calibrators and for potentially revealing details that might make them scientifically interesting in their own right. As the observations of this survey are still in progress, we present preliminary images of a few of the sources that have been observed thus far. When completed, these observations will allow significant improvements in the next generation ICRF.

Thomas, Brianna P.; Peck, Alison B.; Hodge, Jacqueline; Beasley, Anthony J.; VCS Team

2015-01-01

216

High resolution air-coupled ultrasonic imaging of thin materials  

Microsoft Academic Search

This paper describes the use of a focussed air-coupled capacitance transducer combined with pulse compression techniques to form high-resolution images of thin materials in air. The focussing of the device is achieved by using an off-axis parabolic mirror. Initial measurements were performed to determine the lateral resolution of the focussed transducer, which was found to be better than 0.5mm. A

Tat Hean Gan; David A. Hutchins; Duncan R. Billson; David W. Schindel

2002-01-01

217

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

218

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

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

219

Infrared emission high spectral resolution atlas of the stratospheric limb  

SciTech Connect

An atlas of high resolution infrared emission spectra identifies a number of gaseous atmospheric features significant to stratospheric chemistry in the 770--900- and 1100--1360-cm/sup -1/ regions at six zenith angles from 86.7 to 95.1/sup 0/. A balloon-borne Michelson interferometer was flown to obtain /similar to/0.03-cm/sup -1/ resolution spectra. Two 10-cm/sup -1/ extracts are presented here.

Maquire, W.C.; Kunde, V.G.; Herath, L.W.

1989-03-15

220

Active high resolution time delay estimation for large BT signals  

Microsoft Academic Search

Two different high-resolution time-delay estimation (HRTDE) methods, a temporal method and a frequency method, specially adapted to large bandwidth duration (BT) product time-resolvent signals, are described. The performance gain of these methods is shown to be about four times better in comparison with the classical time-delay resolution methods. The frequency HRTDE method is applied to real data obtained from an

Marie-Agnks Pallas; Genevike Jourdain

1991-01-01

221

Ocular Imaging Combining Ultrahigh Resolution and High Speed OCT  

NASA Astrophysics Data System (ADS)

The impact of ultrahigh-resolution and ultrahigh-speed OCT technique on corneal and retinal imaging is shown. The capabilities of advanced OCT system for imaging of the cornea and the thickness determination of the tear film, corneal epithelium, and Bowman's layer over a wide field of view are demonstrated. The high transverse and axial resolution of OCT system allowing one to image individual nerve fiber bundles, the parafoveal capillary network, and individual cone photoreceptors is described.

Schmoll, Tilman; Leitgeb, Rainer A.

222

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

PubMed

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

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

2014-11-01

223

Mass spectrometry imaging with high resolution in mass and space.  

PubMed

Mass spectrometry (MS) imaging links molecular information and the spatial distribution of analytes within a sample. In contrast to most histochemical techniques, mass spectrometry imaging can differentiate molecular modifications and does not require labeling of targeted compounds. We have recently introduced the first mass spectrometry imaging method that provides highly specific molecular information (high resolution and accuracy in mass) at cellular dimensions (high resolution in space). This method is based on a matrix-assisted laser desorption/ionization (MALDI) imaging source working at atmospheric pressure which is coupled to an orbital trapping mass spectrometer. Here, we present a number of application examples and demonstrate the benefit of 'mass spectrometry imaging with high resolution in mass and space.' Phospholipids, peptides and drug compounds were imaged in a number of tissue samples at a spatial resolution of 5-10 ?m. Proteins were analyzed after on-tissue tryptic digestion at 50-?m resolution. Additional applications include the analysis of single cells and of human lung carcinoma tissue as well as the first MALDI imaging measurement of tissue at 3 ?m pixel size. MS image analysis for all these experiments showed excellent correlation with histological staining evaluation. The high mass resolution (R = 30,000) and mass accuracy (typically 1 ppm) proved to be essential for specific image generation and reliable identification of analytes in tissue samples. The ability to combine the required high-quality mass analysis with spatial resolution in the range of single cells is a unique feature of our method. With that, it has the potential to supplement classical histochemical protocols and to provide new insights about molecular processes on the cellular level. PMID:23652571

Römpp, Andreas; Spengler, Bernhard

2013-06-01

224

Isotope specific resolution recovery image reconstruction in high resolution PET imaging  

SciTech Connect

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

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

2014-05-15

225

High resolution BPMS with integrated gain correction system  

SciTech Connect

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

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

2009-08-01

226

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

227

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

E-print Network

-free alternative to convert heat into electricity. This approach relies on scavenging waste heat from automotive exhausts or industrial processes, all of which generate enormous amounts of unused waste heatStudying Thermoelectric Oxides using High-Resolution Scanning Transmission Electron Microscopy 0

Ben-Arie, Jezekiel

228

High-resolution gas chromatography\\/matrix isolation infrared spectrometry  

Microsoft Academic Search

An apparatus is described that allows the collection, within a matrix of condensed inert gas, of the effluent compounds from a high-resolution gas chromatograph. Each collected compound is contained within an area typically 0.3 mm in diameter yielding a concomitant high level of infrared spectral absorbance per nanogram of sample. Tests demonstrate the level of infrared sensitivity, the achievement of

Gerald T. Reedy; Deon G. Ettinger; John F. Schneider; Sidney. Bourne

1985-01-01

229

Shallow Water High Resolution MultiBeam Echo Sounder  

Microsoft Academic Search

This paper presents a Shallow water High Resolution Multi-Beam Echo Sounder (SHMBES), which will be used widely in modern ocean exploration and underwater engineering. It is highly synthesized and developed on the basis of many new techniques such as theories of underwater acoustic and modern signal processing, Very Large Scale Integration (VLSI), DSP array processing, etc. It is mainly composed

Haisen Li; Bin Yao; Tian Zhou; Yukuo Wei; Baowei Chen; Xiao Liu; Haixin Yu; Ningning Weng

2008-01-01

230

Detection of Underground Marlpit Quarries Using High Resolution Seismic  

E-print Network

to the general principle, the increase oife requires powerful and wide band sources (i.e. emitting very short concerning the choice of the source type. In spite of high ground absorption and natural irregularitiesDetection of Underground Marlpit Quarries Using High Resolution Seismic B. Piwakowski* (Ecole

Boyer, Edmond

231

Development of high resolution TDC ASICs at GSI  

Microsoft Academic Search

Based on the long experience on high precision time measurement systems at GSI the GSI ASIC design group is developing a new TDC ASIC for CBM one of the next generation large scale experiments at GSI. The main requirement on the TDC is the high timing resolution < 20 ps. The data acquisition architecture has to be event driven. Two

Holger Flemming; Harald Deppe

2007-01-01

232

Lynx: A High-Resolution Synthetic Aperture Radar  

SciTech Connect

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

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

1999-03-08

233

Vehicle Detection and Classification from High Resolution Satellite Images  

NASA Astrophysics Data System (ADS)

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

Abraham, L.; Sasikumar, M.

2014-11-01

234

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

235

The High Resolution Search for Axions in Galactic Halo Substructure  

NASA Astrophysics Data System (ADS)

The Axion Dark Matter eXperiment uses a Sikivie microwave cavity detector to search for dark matter axions. The new, high resolution channel is designed to search for discrete flows of axions passing through the detector. Such flows are expected to be present in our galactic halo from tidal stripping of dwarf galaxies and from late infall of dark matter on our galactic halo. A discrete flow of axions with small velocity dispersion will appear as a narrow peak in the output of a microwave cavity detector. Such a peak can be searched for with high signal-to-noise ratio using the high resolution channel. This new channel increases the sensitivity of ADMX by a factor of 3, compared to using ADMX's medium resolution channel only.

Duffy, Leanne

2006-10-01

236

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

237

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

238

High-resolution structure of viruses from random diffraction snapshots.  

PubMed

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

2014-07-17

239

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

240

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

241

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

242

Automated frame selection process for analyzing high resolution microendoscope images  

NASA Astrophysics Data System (ADS)

We developed an automated frame selection algorithm for high resolution microendoscope images. The algorithm rapidly selects a representative frame with minimal motion artifact from a short video sequence, enabling fully automated image analysis at the point-of-care. The performance of the algorithm was evaluated by comparing automatically selected frames to manually selected frames using quantitative image parameters. The implementation of fully automated high-resolution microendoscopy at the point-of-care has the potential to reduce the number of biopsies needed for accurate diagnosis of precancer and cancer in low-resource settings, where there may be limited infrastructure and personnel for standard histologic analysis.

Ishijima, Ayumu; Mondrik, Sharon; Schwarz, Richard A.; Vigneswaran, Nadarajah; Gillenwater, Ann M.; Richards-Kortum, Rebecca

2014-05-01

243

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

NASA Technical Reports Server (NTRS)

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

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

1982-01-01

244

Design and test of a High-Resolution EUV Spectroheliometer  

NASA Technical Reports Server (NTRS)

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

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

1992-01-01

245

High resolution collimator system for X-ray detector  

DOEpatents

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

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

1987-01-01

246

Extracting high spatial resolution local gravity field from GRACE data  

NASA Astrophysics Data System (ADS)

GRACE spherical harmonic coefficients are typically limited to degree and order 50 or 60. This means that the spatial resolution of geophysical estimates from GRACE gravity field are limited by truncation errors and leakage of signals from, for example, oceans to continents or from one glacier to another. This results in estimates of local mass balance of glaciers or hydrological catchments being inaccurate. In this paper, we use least squares to estimate discrete mass changes of small regions that sum to the integrated signal as seen by GRACE. The goal is to find the highest spatial resolution that can be estimated from GRACE. We find that the spatial resolution is dependent on the latitude of the region, with greater resolution in high latitude regions where the groundtracks are denser. We show results of two regions: estimating mass changes in Australian continent (mid-latitude) to study hydrology of drainage basins, and estimating mass balance in Greenland (high latitude) to study changes of the ice sheet. We find that high negative correlation between neighbouring regions restrict the spatial resolution that can be achieved.

Darbeheshti, N.; Tregoning, P.; McClusky, S.

2012-04-01

247

High-resolution EEG (HR-EEG) and magnetoencephalography (MEG).  

PubMed

High-resolution EEG (HR-EEG) and magnetoencephalography (MEG) allow the recording of spontaneous or evoked electromagnetic brain activity with excellent temporal resolution. Data must be recorded with high temporal resolution (sampling rate) and high spatial resolution (number of channels). Data analyses are based on several steps with selection of electromagnetic signals, elaboration of a head model and use of algorithms in order to solve the inverse problem. Due to considerable technical advances in spatial resolution, these tools now represent real methods of ElectroMagnetic Source Imaging. HR-EEG and MEG constitute non-invasive and complementary examinations, characterized by distinct sensitivities according to the location and orientation of intracerebral generators. In the presurgical assessment of drug-resistant partial epilepsies, HR-EEG and MEG can characterize and localize interictal activities and thus the irritative zone. HR-EEG and MEG often yield significant additional data that are complementary to other presurgical investigations and particularly relevant in MRI-negative cases. Currently, the determination of the epileptogenic zone and functional brain mapping remain rather less well-validated indications. In France, in 2014, HR-EEG is now part of standard clinical investigation of epilepsy, while MEG remains a research technique. PMID:25648821

Gavaret, M; Maillard, L; Jung, J

2015-03-01

248

Wide-field, high-resolution Fourier ptychographic microscopy  

PubMed Central

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

Zheng, Guoan; Horstmeyer, Roarke; Yang, Changhuei

2014-01-01

249

Rapid and high resolution detection of in situ hybridisation to polytene chromosomes using fluorochrome-labeled RNA.  

PubMed

Fluorochrome-labeled RNA allows the rapid detection of in situ hybrids without the need for long exposure times as in the autoradiographical hybridisation methods. Resolution is high because of the high resolving power of fluorescence microscopy. The application of a previously reported method for the hybrido-cytochemical detection of DNA sequences to polytene chromosomes of Drosophilia is described. The specificity and sensitivity of the method are demonstrated by the hybridisation with polytene chromosomes of 1) rhodamine-labeled 5S RNA, to the 5S rRNA sites of D. melanogaster (56F) and D. hydei (23B), 2) rhodamine-labeled RNA complementary to a plasmid containing histone genes, to the 39DE region of D. melanogaster, 3) rhodamine-labeled D. melanogaster tRNA species (Gly-3 and Arg-2), to their respective loci in D. melanogaster, 4) rhodamine-labeled RNA complementary to the insert of plasmid 232.1 containing part of a D. melanogaster heat shock gene from locus 87C, to D. hydei heat shock locus 2-32A. In the latter instance it was possible to demonstrate the labeling of a double band which escaped unambiguous detection by autoradiography in the radioactive cytochemical hybridisation procedure because of the low topological resolution of autoradiograms. The sensitivity of the fluorochrome-labeled RNA method is compared with the radioactive methods which use 3H- or 125 I-labeled RNAs. The factors governing the sensitivity and the number of bound fluorochrome molecules to be expected are discussed. PMID:6170491

Bauman, J G; Wiegant, J; Van Duijn, P; Lubsen, N H; Sondermeijer, P J; Hennig, W; Kubli, E

1981-01-01

250

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

251

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

252

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

NASA Astrophysics Data System (ADS)

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

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

2011-09-01

253

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

254

Remote Measurements of the Atmosphere with High Spatial Resolution  

NASA Astrophysics Data System (ADS)

Global atmosphere-ocean models are now operating at 3.5 km resolution and mesoscale weather prediction models operating at 1.7 km resolution have been used for the analysis of hurricanes. One can expect that weather prediction models will operate at resolutions better than 5 km during the coming decade. Microwave sensors have contributed valuable information about rainfall and sea surface winds. The Precipitation Radar (PR) onboard the Tropical Rainfall Measuring Mission (TRMM) can address this need. However it may be nearing the end of its life, and its replacement by the Global Precipitation Measurement (GPM) mission is expected no earlier than 2013. Recently the four Italian Cosmo-SkyMed, and the German Terra-SAR X-band synthetic aperture radars (SAR’s) have displayed rain distributions with resolution better than 0.5 km. The Quickscat also now provides distributions of rainfall and sea surface winds with 2.5 km resolution. We will describe rainfall retrieval algorithms, show rainfall distributions retrieved from Terra-SAR, and discuss errors in those measurements. We will also describe multi-frequency radar measurements of sea surface winds and rainfall during hurricanes. Although most remotely sensed rainfall and wind data can be expected to be obtained from satellites, unmanned aerial vehicles (UAV’s) with one week cruising duration and ~180 kg payloads flying at 18 km height may become attractive platforms from which severe weather can be tracked with high resolution.

Weinman, J. A.; Marzano, F. S.; Mugnai, A.

2009-09-01

255

Remote sensing cloud properties from high spectral resolution infrared observations  

NASA Technical Reports Server (NTRS)

A technique for estimating cloud radiative properties (spectral emissivity and reflectivity) in the IR is developed based on observations at a spectral resolution of approximately 0.5/cm. The algorithm uses spectral radiance observations and theoretical calculations of the IR spectra for clear and cloudy conditions along with lidar-determined cloud-base and cloud-top pressure. An advantage of the high spectral resolution observations is that the absorption effects of atmospheric gases are minimized by analyzing between gaseous absorption lines. The technique is applicable to both ground-based and aircraft-based platforms and derives the effective particle size and associated cloud water content required to satisfy, theoretically, the observed cloud IR spectra. The algorithm is tested using theoretical simulations and applied to observations made with the University of Wisconsin's ground-based and NASA ER-2 aircraft High-Resolution Infrared Spectrometer instruments.

Smith, William L.; Ma, Xia L.; Ackerman, Steven A.; Revercomb, H. E.; Knuteson, R. O.

1993-01-01

256

High Resolution VUV Spectrometer at the INDUS-1 Synchrotron Source  

SciTech Connect

An indigenously developed high-resolution vacuum ultraviolet (VUV) spectrometer has recently been commissioned at the INDUS-1 Synchrotron Source, Indore, India for carrying out spectroscopic research of atomic and molecular gases. The spectrometer uses a 6.65-meter concave grating in off-plane Eagle mounting and a photomultiplier tube (PMT) for recording the intensity profile of various spectral lines. Experimental performance of the spectrometer has been tested using laboratory sources and 1200 grooves/mm and 4800 grooves/mm concave gratings. Wavelength resolutions of 0.08 Aa and 0.01 Aa have been achieved when 1200 grooves/mm and 4800 grooves/mm concave gratings have been mounted successfully in the spectrometer. The instrument has been integrated with the high resolution VUV beamline at INDUS-1 and its performance is being evaluated with synchrotron radiation.

Das, Nimai C.; Shukla, Ram P.; Udupa, Dinesh V.; Sahoo, Naba K.; Bhattacharyya, Dibyendu; Sunanda, K.; Saraswathy, P. [Spectroscopy Division, Bhabha Atomic Research Centre, Mumbai -400 085 (India)

2007-01-19

257

High-resolution spectral imaging based on coded dispersion.  

PubMed

Since the energy of the incident light is constant, the spatial and spectral resolution can hardly be improved without scarifying the other with the spectral imaging method of a pushbroom scanner. Thus, a new spectral imaging method is proposed to obtain a high-resolution (HR) spectral image with a low-resolution detector array. The method, namely coded dispersion, by which compressive measurement is achieved, improves light collection efficiency, and then a high-quality reconstructed HR spectral image is obtained with fewer sensors. The simulation result shows that with prior knowledge of scenes available, the proposed method also offers a new way to acquire an HR spectral image while the density of detector array is constrained by battery, capacity, transmission bandwidth, and cost. PMID:23400066

Lin, Yaohai; Shi, Guangming; Gao, Dahua; Liu, Danhua

2013-02-10

258

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

259

Science with High Spatial Resolution Far-Infrared Data  

NASA Technical Reports Server (NTRS)

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

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

1994-01-01

260

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

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

2013-12-01

261

Spin-Echo fMRI in Humans Using High Spatial Resolutions and High Magnetic Fields  

E-print Network

cortex at 4 and 7 T. This study used high spatial resolution, afforded by the increased signal fields, such as 7 T, the contribution of large vessels to GRE BOLD decreases relative to the microvasSpin-Echo fMRI in Humans Using High Spatial Resolutions and High Magnetic Fields Essa Yacoub

Duong, Timothy Q.

262

A compact high-resolution X-ray powder diffractometer  

PubMed Central

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

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

2013-01-01

263

A comparative autoradiography study in post mortem whole hemisphere human brain slices taken from Alzheimer patients and age-matched controls using two radiolabelled DAA1106 analogues with high affinity to the peripheral benzodiazepine receptor (PBR) system.  

PubMed

The binding of two radiolabelled analogues (N-(5-[125I]Iodo-2-phenoxyphenyl)-N-(2,5-dimethoxybenzyl)acetamide ([125I]desfluoro-DAA1106) and N-(5-[125I]Fluoro-2-phenoxyphenyl)-N-(2-[125I]Iodo-5-methoxybenzyl)acetamide ([125I]desmethoxy-DAA1106) of the peripheral benzodiazepine receptor (PBR) (or TSPO, 18kDa translocator protein) ligand DAA1106 was examined by in vitro autoradiography on human post mortem whole hemisphere brain slices obtained from Alzheimer's disease (AD) patients and age-matched controls. Both [(125)I]desfluoro-IDAA1106 and [(125)I]desmethoxy-IDAA1106 were effectively binding to various brain structures. The binding could be blocked by the unlabelled ligand as well as by other PBR specific ligands. With both radiolabelled compounds, the binding showed regional inhomogeneity and the specific binding values proved to be the highest in the hippocampus, temporal and parietal cortex, the basal ganglia and thalamus in the AD brains. Compared with age-matched control brains, specific binding in several brain structures (temporal and parietal lobes, thalamus and white matter) in Alzheimer brains was significantly higher, indicating that the radioligands can effectively label-activated microglia and the up-regulated PBR/TSPO system in AD. Complementary immunohistochemical studies demonstrated reactive microglia activation in the AD brain tissue and indicated that increased ligand binding coincides with increased regional microglia activation due to neuroinflammation. These investigations yield further support to the PBR/TSPO binding capacity of DAA1106 in human brain tissue, demonstrate the effective usefulness of its radio-iodinated analogues as imaging biomarkers in post mortem human studies, and indicate that its radiolabelled analogues, labelled with short half-time bioisotopes, can serve as prospective in vivo imaging biomarkers of activated microglia and the up-regulated PBR/TSPO system in the human brain. PMID:18984021

Gulyás, Balázs; Makkai, Boglárka; Kása, Péter; Gulya, Károly; Bakota, Lidia; Várszegi, Szilvia; Beliczai, Zsuzsa; Andersson, Jan; Csiba, László; Thiele, Andrea; Dyrks, Thomas; Suhara, Tetsua; Suzuki, Kazutoshi; Higuchi, Makato; Halldin, Christer

2009-01-01

264

EVALUATING HIGH RESOLUTION QUICKBIRD SATELLITE IMAGERY FOR ESTIMATING COTTON YIELD  

Technology Transfer Automated Retrieval System (TEKTRAN)

High spatial resolution imagery from recently launched satellite sensors offers new opportunities for crop management. The objective of this study was to evaluate QuickBird satellite imagery for mapping plant growth and yield variability in cotton fields. A QuickBird image scene with 2.8 m resolutio...

265

High-resolution EUS in children with eosinophilic “allergic” esophagitis  

Microsoft Academic Search

Background: The pathophysiology of dysphagia associated with eosinophilic esophagitis is unknown. This study investigated possible anatomic alterations in children with eosinophilic esophagitis in comparison with healthy children by using high-resolution EUS to precisely measure individual tissue layers of the esophagus. Methods: Children with eosinophilic esophagitis (n = 11) and control children (n = 8) without esophagitis were prospectively evaluated by

Victor L. Fox; Samuel Nurko; Jonathan E. Teitelbaum; Kamran Badizadegan; Glenn T. Furuta

2003-01-01

266

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

267

High resolution x-ray tomography in an electron microprobe  

Microsoft Academic Search

Conversion of an electron microprobe for use as an x-ray microtomograph is described. Only minor modifications are required, indeed several of the utilities of the microprobe can be used to ensure high resolution radiography and tomography. System performance was evaluated by analysis of glass fiber reinforced polymer composites and of a carbonate reservoir rock. Individual glass fibers of 10 and

Rogério Ferreira de Paiva; Michel Bisiaux; John Lynch; Elisabeth Rosenberg

1996-01-01

268

High resolution measurements in liquid metal by focused ultrasonic wave  

Microsoft Academic Search

High spatial resolution measurements in molten zinc at temperatures more than 600 °C are performed using a focused ultrasonic pulse-echo technique with clad metallic buffer rods. The focused ultrasonic waves are generated by a spherical acoustic lens which is fabricated at the end of the buffer rod. In order to evaluate its focussing ability, several experiments are carried out in

I. Ihara; C.-K. Jen; D. Ramos França

2000-01-01

269

High resolution power spectra of daily Zurich sunspot numbers  

NASA Technical Reports Server (NTRS)

High resolution power spectra of 77 years of Zurich daily sunspot numbers were computed using various lags and data point intervals. Major harmonic peaks of the approximately 124-month period showed up strongly as well as the 27-day solar rotational period.

Euler, H. C., Jr.

1973-01-01

270

High Resolution Methods and Adaptive Refinement for Tsunami Propagation and  

E-print Network

High Resolution Methods and Adaptive Refinement for Tsunami Propagation and Inundation. David L volume methods and adaptive refinement for the shallow water equations in the context of tsunami modeling contexts, however, tsunami modeling presents some unique challenges that must be overcome. We describe some

LeVeque, Randy

271

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

272

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

E-print Network

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

Hooper, Scott

273

High-resolution speech signal reconstruction in Wireless Sensor Networks  

E-print Network

High-resolution speech signal reconstruction in Wireless Sensor Networks Andria Pazarloglou, Radu With the recent growth of Wireless Sensor Networks (WSNs), many advanced application areas have received sig, rgutier}@cs.tamu.edu Abstract--Data streaming is an emerging class of applica- tions for sensor networks

Gutierrez-Osuna, Ricardo

274

Earthquake Damage Identification using High-Resolution Satellite  

E-print Network

& evaluation · High-resolution satellite imagery · Images from Boumerdes, Algeria · Semi-automated damage, 7:44 pm, Mw 6.8 from neic.usgs.gov #12;Satellite Images · 3 Quickbird images of Boumerdes ­ 22 April requires 64 km2 minimum size #12;Boumerdes 23 May 2003 500 m #12;SW Boumerdes ­ April 02 Buildings, roads

Shinozuka, Masanobu

275

High-resolution terahertz atmospheric water vapor continuum measurements  

E-print Network

transmission window at 1.5THz. The transmission of broadband terahertz radiation through pure water vaporHigh-resolution terahertz atmospheric water vapor continuum measurements David M. Slocum,* Thomas M, Lowell, MA 01854, United States ABSTRACT The terahertz frequency regime is often used as the `chemical

Massachusetts at Lowell, University of

276

Application of Classification Models to Pharyngeal High-Resolution Manometry  

ERIC Educational Resources Information Center

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

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

2012-01-01

277

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

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

278

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

279

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

280

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...

281

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...

282

High-Resolution Seismic Reflection to Monitor Change  

Microsoft Academic Search

High-resolution seismic reflection has proven a valuable tool detecting changes in fluid composition, rock petrophysical properties, and structures critical to reservoir production management and groundwater protection in Kansas. Surface seismic reflection is not a method that lends itself to direct detection and delineation of boundaries between different fluid compositions in porous media. However, time-lapse seismic does appear to have been

R. D. Miller; A. E. Raef; J. L. Lambrecht; A. P. Byrnes

2006-01-01

283

High-Resolution Nuclear Magnetic Resonance of Solids.  

ERIC Educational Resources Information Center

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

Maciel, Gary E.

1984-01-01

284

High-resolution elasticity imaging for tissue engineering  

Microsoft Academic Search

An elasticity microscope provides high resolution images of tissue elasticity. With this instrument, it may be possible to monitor cell growth and tissue development in tissue engineering. To test this hypothesis, elasticity micrographs were obtained in two model systems commonly used for tissue engineering. In the first, strain images of a tissue-engineered smooth muscle sample clearly identified a several hundred

N. Abraham Cohn; B.-S. Kim; R. Q. Erkamp; D. J. Mooney; S. Y. Emelianov; A. R. Skovoroda; M. O'Donnell

2000-01-01

285

Gemini high-resolution optical spectrograph conceptual design  

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

286

Calibration of advanced very high resolution radiometer infrared observations  

Microsoft Academic Search

A detailed analysis of the calibration procedures for the NOAA advanced very high resolution radiometer (AVHRR) based on thermal vacuum test data was performed as part of the Warm Core Rings Experiment. Systematic differences in the derived calibration results and those reported in the various addenda to work by Lauritson et al. (1979) were found. A weak, but important, dependence

O. B. Brown; R. H. Evans; J. W. Brown

1985-01-01

287

Genetic Analysis of High Angular Resolution Diffusion Images (HARDI)  

E-print Network

Diffusion Imaging, tensor distribution function, structural equation model, twins, quantitative geneticsGenetic Analysis of High Angular Resolution Diffusion Images (HARDI) Liang Zhan1 , Alex D. Leow2 of Medical Research, Brisbane, Australia Abstract. Imaging genetics is a new field that extends methods from

Thompson, Paul

288

MULTIPARENTAL POPULATIONS High-Resolution Genetic Mapping of Complex Traits  

E-print Network

to fearful or stressful events (Mahan and Ressler 2012). Twin and family studies support a genetic basisMULTIPARENTAL POPULATIONS High-Resolution Genetic Mapping of Complex Traits from a Combined in Neuroscience, Middlebury College, Middlebury, Vermont 05753, and Department of Human Genetics and Department

Abney, Mark

289

Atmospheric correction of Advanced Very High Resolution Radiometer imagery  

Microsoft Academic Search

The present paper proposes an automated approach to estimate the aerosol reflectance at the Advanced Very High Resolution Radiometer (AVHRR) red channel. The aerosol dominant pixels were separated through two orthogonal transforms. The aerosol reflectance ratio at these pixels was estimated through regression. The results are validated with in situ measurements. The retrieved water-leaving reflectance matched the modelled values with

Mhd. Suhyb Salama; Jaak Monbaliu; Pol Coppin

2004-01-01

290

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

291

High energy-resolution inelastic x-ray scattering  

SciTech Connect

A brief review is presented of various aspects of high energy-resolution inelastic x-ray scattering based on synchrotron sources. We show what kinematical advantages are provided by the photon probe and propose mirror and monochromator designs to achieve an optically efficient beam line for inelastic x-ray scattering.

Hastings, J.B.; Moncton, D.E.; Fujii

1984-01-01

292

High-resolution photography of the solar chromosphere  

Microsoft Academic Search

High-resolution observations of the low chromosphere beyond the limb at the centre of the Ha line reveal the existence of two types of fine structure whose presence has hitherto been unobserved: (1) small bright features which show a close correspondence in properties with the bright mottles on the disk and are unequivocally identifiable as the latter seen beyond the limb;

R. E. Loughhead

1969-01-01

293

HIGH RESOLUTION SPECTROSCOPY OF RECENTLY DISCOVERED CHROMOSPHERICALLY ACTIVE BINARY STARS  

E-print Network

567 HIGH RESOLUTION SPECTROSCOPY OF RECENTLY DISCOVERED CHROMOSPHERICALLY ACTIVE BINARY STARS M. C, we have obtained information about orbital solution and about the activity of the chromosphere the Ca II H & K to Ca II IRT lines) that are formed at different heights in the chromosphere

Complutense de Madrid, Universidad

294

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

295

A High-resolution Reanalysis for the European CORDEX Region  

NASA Astrophysics Data System (ADS)

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

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

2014-05-01

296

Solutions on high-resolution multiple configuration system sensors  

NASA Astrophysics Data System (ADS)

For aim to achieve an improved resolution in modern image domain, a method of continuous zoom multiple configuration, with a core optics is attempt to establish model by novel principle on energy transfer and high accuracy localization, by which the system resolution can be improved with a level in nano meters. A comparative study on traditional vs modern methods can demonstrate that the dialectical relationship and their balance is important, among Merit function, Optimization algorithms and Model parameterization. The effect of system evaluated criterion that MTF, REA, RMS etc. can support our arguments qualitatively.

Liu, Hua; Ding, Quanxin; Guo, Chunjie; Zhou, Liwei

2014-11-01

297

High Resolution 3d Brain PET with Hybrid Photon Detectors  

NASA Astrophysics Data System (ADS)

The design of a high resolution 3 dimensional brain PET is presented. Thanks to its novel geometry a 3D measurement of the gamma interaction point in the detector is possible. Each 3D PET camera module consists of a matrix of long scintillation crystals, axially oriented, readout on both sides by Hybrid Photon Detectors. This concept leads to an image reconstruction free of parallax error and provides a uniform spatial and energy resolution over the whole sensitive volume. Furthermore it allows to enhance sensitivity by reconstructing a substantial fraction of the gamma quanta that underwent Compton scattering in the detectors.

Llatas, M. Chamizo; Braem, A.; Chesi, E.; Joram, C.; Mathot, S.; Seguinot, J.; Weilhammer, P.; Garibaldi, F.; Nappi, E.; Schoenahl, F.; Zaidi, H.

2004-07-01

298

Very high resolution seismic profiling at the Brazil Margin  

NASA Astrophysics Data System (ADS)

Acoustically stratified seismic images are widely used in studies of sedimentation mechanisms producing thick sedimentary aprons on continental rises. However, insuffcient vertical resolution of seismic records commonly restricts a more detailed interpretation of individual reflectors within accumulations to reconstruct specifc short-term sedimentological events. (Reflectors correspond to boundaries between sedimentary layers with different acoustic properties and are imaged in seismic records as continuous lines.) Very high resolution (VHR) seismic profiling conducted during Cruise 33 of the Russian research vessel Akademik Ioffe (2011) provided correlation of acoustic reflectors, distanced from one another by less than 50 centimeters, with thin sedimentary layers recovered by gravity cores.

Murdmaa, I. O.; Borisov, D. G.; Demidova, T. A.; Ivanova, E. V.; Levchenko, O. V.; Marinova, Y. G.; Mutovkin, A. D.; Putans, V. A.; Humbs, Peter; Skolotnev, S. G.; Peyve, A. A.

2012-06-01

299

Description of the High Resolution Fly's Eye Detector  

Microsoft Academic Search

The High Resolution Fly's Eye experiment measures properties of the highest energy cosmic rays. The air fluorescence technique used in HiRes was previously demonstrated by the original Fly's Eye detector. The HiRes Observatory is the realization of the next stage of air fluorescence observation of ultra high energy cosmic rays. The observatory has been operating in various sub-configurations since spring

2001-01-01

300

Calibration of the high resolution spectrometer barrel calorimeter at PEP  

Microsoft Academic Search

The High-Resolution Spectrometer (HRS) is a general-purpose detector for the study of high-energy electron-positron collisions. The HRS has been in data-taking operation since early 1982. This report covers the calibration of the barrel shower counter system. The barrel system consists of 40 modules placed in a circular arch having a mean radius of 2.1 m. Each module covers an azimuthal

Loos

1983-01-01

301

High Resolution Imaging X-ray Spectroscopy of Mars  

Microsoft Academic Search

The first observation of Mars with XMM-Newton, in November 2003, has provided a wealth of novel information about the X-ray properties of our neighbouring planet. High resolution imaging spectroscopy with RGS clearly shows that its X-ray emission is composed of two different components: fluorescent scattering of solar X-rays on neutral molecules in its upper atmosphere, and emission from highly charged

K. Dennerl

2006-01-01

302

High Resolution Programmable Digital Delay Generator Design and Realization  

Microsoft Academic Search

This article introduced a design principles and implementation method of a high resolution programmable digital delay generator. It described the system's composition in hardware and software view. This system is composed of deserializer MAX3885, high-speed clock generator AD9517-1, DDR2 SDRAM, serializer and USB2.0 Controller. Paper described FPGA software design methods includes DDR2 SDRAM controller and commands receive module. Modularized design

Sun Zhaolin; Li Nan; Wang Yinan; Yin Qinghong; Xu Xin; Guo Jing; Liu Haijun; Xu Hui

2010-01-01

303

High-Resolution Angioscopic Imaging During Endovascular Neurosurgery  

PubMed Central

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

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

2014-01-01

304

Photoacoustic lymphatic imaging with high spatial-temporal resolution  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

305

Bayesian Peptide Peak Detection for High Resolution TOF Mass Spectrometry  

PubMed Central

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

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

2011-01-01

306

Tuning and scanning control system for high resolution alexandrite lasers  

NASA Technical Reports Server (NTRS)

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

Smith, James C.; Schwemmer, Geary K.

1988-01-01

307

High resolution infrared absorptivities for gaseous chlorine nitrate. [in stratosphere  

NASA Technical Reports Server (NTRS)

High resolution infrared absorptivities of chlorine nitrate (ClONO2) are required in order to quantitatively evaluate, by examination of infrared spectra obtained recently from balloon-borne spectrometers, the possible occurrence of this compound in the stratosphere. In the present study, infrared absorptivities for four absorption bands of gaseous ClONO2 have been measured at 0.0625 per cm spectral resolution with a Fourier transform infrared (FT-IR) system. Spectra were obtained at two pressures (0.05 and 1.05 torr) of pure ClONO2 and with 125 torr of N2 added to a 0.50 torr sample. Absorptivities for a range of spectral resolutions (0.0625, 0.125, 0.25 and 0.50 per cm) have been calculated from the data.

Graham, R. A.; Tuazon, E. C.; Winer, A. M.; Pitts, J. N., Jr.; Molina, L. T.; Beaman, L.; Molina, M. J.

1977-01-01

308

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

309

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. 6 figs.

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

1998-07-07

310

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

311

SPRED spectrograph upgrade: high resolution grating and improved absolute calibrations  

SciTech Connect

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

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

1986-05-01

312

Bendable X-ray Optics for High Resolution Imaging  

NASA Technical Reports Server (NTRS)

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

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

2014-01-01

313

Performance characterization of a new high resolution PET scintillation detector  

NASA Astrophysics Data System (ADS)

Performance of a new high resolution PET detection concept is presented. In this new concept, annihilation radiation enters the scintillator detectors edge-on. Each detector module comprises two 8 × 8 LYSO scintillator arrays of 0.91 × 0.91 × 1 mm3 crystals coupled to two position-sensitive avalanche photodiodes (PSAPDs) mounted on a flex circuit. Appropriate crystal segmentation allows the recording of all three spatial coordinates of the interaction(s) simultaneously with submillimeter resolution. We report an average energy resolution of 14.6 ± 1.7% for 511 keV photons at FWHM. Coincident time resolution was determined to be 2.98 ± 0.13 ns FWHM on average. The coincidence point spread function (PSF) has an average FWHM of 0.837 ± 0.049 mm (using a 500 \\,\\rm \\mu m spherical source) and is uniform across the arrays. Both PSF and coincident time resolution degrade when Compton interactions are included in the data. Different blurring factors were evaluated theoretically, resulting in a calculated PSF of 0.793 mm, in good agreement with the measured value.

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

2010-10-01

314

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

315

Performance characterization of a new high resolution PET scintillation detector  

PubMed Central

Performance of a new high resolution PET detection concept is presented. In this new concept, annihilation radiation enters the scintillator detectors edge-on. Each detector module comprises two 8 × 8 LYSO scintillator arrays of 0.91 × 0.91 × 1 mm3 crystals coupled to two position-sensitive avalanche photodiodes (PSAPDs) mounted on a flex circuit. Appropriate crystal segmentation allows the recording of all three spatial coordinates of the interaction(s) simultaneously with submillimeter resolution. We report an average energy resolution of 14.6 ± 1.7% for 511 keV photons at FWHM. Coincident time resolution was determined to be 2.98 ± 0.13 ns FWHM on average. The coincidence point spread function (PSF) has an average FWHM of 0.837 ± 0.049 mm (using a 500 ?m spherical source) and is uniform across the arrays. Both PSF and coincident time resolution degrade when Compton interactions are included in the data. Different blurring factors were evaluated theoretically, resulting in a calculated PSF of 0.793 mm, in good agreement with the measured value. PMID:20844332

Foudray, A M K; Olcott, P D

2013-01-01

316

Development of High Resolution Scintillator Systems Based on Photocell Technology  

SciTech Connect

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

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

2006-01-01

317

Accelerated High-Resolution Differential Ion Mobility Separations Using Hydrogen  

PubMed Central

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

Shvartsburg, Alexandre A.; Smith, Richard D.

2011-01-01

318

High resolution meteorological modellingof the Inn Valley atmosphere, Part I  

NASA Astrophysics Data System (ADS)

Orography and local meteorology play a major role in Alpine valleys, as they are linked with valley and slope wind systems, stagnation and recirculation, temperature inversions and turbulence. Thus, they have a strong influence of transport and dilution of pollutants in the valley, affecting human health, and sound propagation. Shallow stable layers at the valley floor and low wind speed conditions, especially in autumn and winter, trap pollutants and thus cause unfavourable dispersion conditions , possibly leading to exceedances of air pollution limits. Moreover, under certain synoptic conditions such as persistent high-pressure systems inversion conditions prevail for days. Emissions may accumulate in the valley from day to day and thus critical levels of pollutants may be reached. With the current computer capabilities, numerical meteorological models and particle dispersion models are powerful tools to investigate such situations and their impact on emission-side measures. However, alpine valleys and other complex topographical areas require very high resolutions to ensure accurate representation of the physical processes. Typically, the highest resolutions used nowadays in episodic simulations with models such as, e.g., RAMS, WRF, or MM5, are around 1 km. This still smooths the orography, cutting the peaks and raising the valley bottoms. In this work a comparison of the simulation of the valley atmosphere with two meteorological models, MM5 and WRF, with high horizontal (0.6 km to 0.2 km) and vertical resolutions (35 to 39 half-s levels) is carried out for selected scenarios in which levels of pollutants exceeded air pollution limits. For a better representation of the orography SRTM 3" topography data is used in MM5 for resolutions below 1 km (~ resolution of SRTM 30" data), WRF will be tested only with SRTM 30" due to computational time constraints. The evolution of the valley atmosphere is studied using different PBL schemes available in the models as well as land-use representations. Rawinsonde data of the Innsbruck airport station and observation data of Innsbruck University and Patscherkofel will be used for comparison. These high-resolution simulations are very demanding in computational terms. Therefore, an evaluation of the computer demands of each of the simulations is also carried out. In order to asses the influence of this high resolution meteorological modelling on air quality conditions, further work with a dispersion model/chemistry model will be carried out and compared to observations (see contribution by Arnold et al., this session).

Schicker, I.; Arnold, D.; Seibert, P.

2009-09-01

319

Validation of AIRS high-resolution stratospheric temperature retrievals  

NASA Astrophysics Data System (ADS)

This paper focuses on stratospheric temperature observations by the Atmospheric InfraRed Sounder (AIRS) aboard NASA's Aqua satellite. We validate a nine-year record (2003 - 2011) of data retrieved with a scientific retrieval processor independent from the operational processor operated by NASA. The retrieval discussed here provides stratospheric temperature profiles for each individual AIRS footprint and has nine times better horizontal sampling than the operational data provided by NASA. The high-resolution temperature data are considered optimal for for gravity wave studies. For validation the high-resolution retrieval data are compared with results from the AIRS operational Level-2 data and the ERA-Interim meteorological reanalysis. Due to the large amount of data we performed statistical comparisons of monthly zonal mean cross-sections and time series. The comparisons show that the high-resolution temperature data are in good agreement with the validation data sets. The bias in the zonal averages is mostly within ±2K. The bias reaches a maximum of 7K to ERA-Interim and 4K to the AIRS operational data at the stratopause, it is related to the different resolutions of the data sets. Variability is nearly the same in all three data sets, having maximum standard deviations around the polar vortex in the mid and upper stratosphere. The validation presented here indicates that the high-resolution temperature retrievals are well-suited for scientific studies. In particular, we expect that they will become a valuable asset for future studies of stratospheric gravity waves.

Meyer, Catrin I.; Hoffmann, Lars

2014-10-01

320

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

DOEpatents

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

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

2006-10-31

321

High resolution hypernuclear spectroscopy in a wide mass region  

NASA Astrophysics Data System (ADS)

High resolution hypernuclear spectroscopy for medium heavy and heavy hypernuclei will enable us to extract the spin dependent ?-N interaction beyond p-shell and help us understand the role of strangeness in dense nuclear matter. In the light mass region, hypernuclear spectroscopy by electroproduction will help us understand the effect of Charge Symmetry Broken (CSB) by studying neutron rich hypernuclei and reveal new nuclear structure aspects induced by strangeness. The preliminary results from JLab HKS experiment, which was carried out in 2005, has demonstrated the ability of hypernuclear electroproduction in obtaining high resolution spectroscopy by utilizing high precision electron beam. In this talk, I will present the current updated spectra of ^12?B, ^28?Al and ^7?He. The experimental setup and spectrometer calibration procedure will also be described.

Yuan, Lulin

2007-10-01

322

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

323

Sparse Recovery Analysis of High-Resolution Climate Data  

NASA Astrophysics Data System (ADS)

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

Archibald, R.

2013-12-01

324

High Resolution Optical Spectra of HBC 722 After Outburst  

NASA Astrophysics Data System (ADS)

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

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

2011-04-01

325

Imaging collagen type I fibrillogenesis with high spatiotemporal resolution.  

PubMed

Fibrillar collagens, such as collagen type I, belong to the most abundant extracellular matrix proteins and they have received much attention over the last five decades due to their large interactome, complex hierarchical structure and high mechanical stability. Nevertheless, the collagen self-assembly process is still incompletely understood. Determining the real-time kinetics of collagen type I formation is therefore pivotal for better understanding of collagen type I structure and function, but visualising the dynamic self-assembly process of collagen I on the molecular scale requires imaging techniques offering high spatiotemporal resolution. Fast and high-speed scanning atomic force microscopes (AFM) provide the means to study such processes on the timescale of seconds under near-physiological conditions. In this study we have applied fast AFM tip scanning to study the assembly kinetics of fibrillar collagen type I nanomatrices with a temporal resolution reaching eight seconds for a frame size of 500 nm. By modifying the buffer composition and pH value, the kinetics of collagen fibrillogenesis can be adjusted for optimal analysis by fast AFM scanning. We furthermore show that amplitude-modulation imaging can be successfully applied to extract additional structural information from collagen samples even at high scan rates. Fast AFM scanning with controlled amplitude modulation therefore provides a versatile platform for studying dynamic collagen self-assembly processes at high resolution. PMID:25486377

Stamov, Dimitar R; Stock, Erik; Franz, Clemens M; Jähnke, Torsten; Haschke, Heiko

2015-02-01

326

High Resolution Imaging of Structure and Diffusion Gregory S. Boebinger, National High Magnetic Field Laboratory  

E-print Network

High Resolution Imaging of Structure and Diffusion Gregory S. Boebinger, National High Magnetic resolution magnetic resonance imaging (MRI) allow us to examine biological tissues and materials structures physiologically relevant conditions and to monitor fluid diffusion in complex structures. We recently measured

Weston, Ken

327

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

328

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

329

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

330

Temporal analysis of all high-resolution Mars imaging products  

NASA Astrophysics Data System (ADS)

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

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

2014-04-01

331

High Resolution Measurements and Electronic Structure Calculations of a Diazanaphthalene  

NASA Astrophysics Data System (ADS)

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

Gruet, Sébastien; Goubet, Manuel; Pirali, Olivier

2014-06-01

332

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

333

Adaptive optics with pupil tracking for high resolution retinal imaging  

PubMed Central

Adaptive optics, when integrated into retinal imaging systems, compensates for rapidly changing ocular aberrations in real time and results in improved high resolution images that reveal the photoreceptor mosaic. Imaging the retina at high resolution has numerous potential medical applications, and yet for the development of commercial products that can be used in the clinic, the complexity and high cost of the present research systems have to be addressed. We present a new method to control the deformable mirror in real time based on pupil tracking measurements which uses the default camera for the alignment of the eye in the retinal imaging system and requires no extra cost or hardware. We also present the first experiments done with a compact adaptive optics flood illumination fundus camera where it was possible to compensate for the higher order aberrations of a moving model eye and in vivo in real time based on pupil tracking measurements, without the real time contribution of a wavefront sensor. As an outcome of this research, we showed that pupil tracking can be effectively used as a low cost and practical adaptive optics tool for high resolution retinal imaging because eye movements constitute an important part of the ocular wavefront dynamics. PMID:22312577

Sahin, Betul; Lamory, Barbara; Levecq, Xavier; Harms, Fabrice; Dainty, Chris

2012-01-01

334

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

335

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

336

High-resolution imaging of the supercritical antisolvent process  

NASA Astrophysics Data System (ADS)

A high-magnification and high-resolution imaging technique was developed for the supercritical fluid antisolvent (SAS) precipitation process. Visualizations of the jet injection, flow patterns, droplets, and particles were obtained in a high-pressure vessel for polylactic acid and budesonide precipitation in supercritical CO2. The results show two regimes for particle production: one where turbulent mixing occurs in gas-like plumes, and another where distinct droplets were observed in the injection. Images are presented to demonstrate the capabilities of the method for examining particle formation theories and for understanding the underlying fluid mechanics, thermodynamics, and mass transport in the SAS process.

Bell, Philip W.; Stephens, Amendi P.; Roberts, Christopher B.; Duke, Steve R.

2005-06-01

337

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

338

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

339

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.

340

High-resolution spectroscopy using direct reactions of RI beams  

NASA Astrophysics Data System (ADS)

Nuclear spectroscopy via direct reactions of RI beams is discussed especially for focusing on charge exchange reactions of unstable nuclei. As an example, study of isospin multiplets of drip-line nuclei is presented discussing neutron halo phenomena studied by proton decay of isobaric analog states populated by the (p,n) reaction around 70 A MeV. The SHARAQ project is presented along high-resolution nuclear spectroscopy using RI beams at 150-350 A MeV, where the characteristics of exothemic charge exchange reactions are discussed. The present status of construction of the SHARAQ spectrometer and the high-resolution beam line in the RIBF at RIKEN are presented.

Shimoura, Susumu

2009-05-01

341

Advances in turbulent flow computations using high-resolution methods  

NASA Astrophysics Data System (ADS)

The paper reviews research activity in connection with the use of high-resolution methods in turbulent flow computations. High-resolution methods have proven to successfully compute a number of turbulent flows without need to resort to an explicit turbulence model. Here, we review the basic properties of these methods, present evidence from the successful implementation of these methods in turbulent flows, and discuss theoretical arguments and recent research aiming at justifying their use as an implicit turbulence model. Further, we discuss numerical issues that still need to be addressed. These include the relation of the dissipation and dispersion properties with turbulence properties such as turbulence anisotropy, as well as further validation of the methods in under-resolved simulations of near-wall turbulent attached and separated flows.

Drikakis, Dimitris

2003-10-01

342

Lateral shearing interferometry for high-resolution EUV optical testing  

NASA Astrophysics Data System (ADS)

Next generation EUV optical systems are moving to higher resolution optics to accommodate the smaller length scales targeted by the semiconductor industry. As the numerical apertures (NA) of the optics become larger, it becomes increasingly difficult to characterize aberrations, which broaden the point-spread function and thus limit the ultimate resolution of an optical system. Lateral shearing interferometry (LSI) provides an attractive alternative to conventional interferometric techniques such as point diffraction interferometry due to its experimental simplicity, stability, relaxed coherence requirements, and its ability to scale to high numerical apertures. In this paper we present an analytical solution to the LSI interferogram in various NA regimes. We demonstrate that systematic aberrations present in high NA interferograms due to grating distortion of the diffracted order angular spectrum are measurable and must be compensated for in the reconstruction algorithm.

Miyakawa, Ryan; Naulleau, Patrick

2011-04-01

343

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

344

High-Resolution Ocuar Imaging: Combining Advanced Optics and Microtechnology  

PubMed Central

Recent developments in imaging technologies offer great potential for the assessment of retinal ganglion cell disorders, with particular relevance to glaucoma. In particular, advances in this field have allowed unprecedented in vivo access to the retinal layers, using many different properties of light to differentiate cellular structures. This article is a summary of currently available and investigational advanced, high-resolution imaging technologies and their potential applications to glaucoma. It represents the topics of discussion at the annual Optic Nerve Rescue and Restoration Think Tank, sponsored by The Glaucoma Foundation, entitled “High Resolution Imaging of the Eye: Advanced Optics, Microtechnology and Nanotechnology” and held in New York, New York, September 28-29, 2007. PMID:19772272

Cordeiro, M. Francesca; Nickells, Robert; Drexler, Wolfgang; Borrás, Terete; Ritch, Robert

2014-01-01

345

Robust data reduction of high spatial resolution optical vibration measurements  

NASA Astrophysics Data System (ADS)

In several mechanical engineering applications high spatial resolution measurements are required. Adapted optical measurement instruments such as the laser scanning Doppler vibrometer (SLDV) and the electronic speckle pattern interferometer (ESPI) exist to perform this task. The result of this high spatial resolution measurement is that a large amount of data is available which has to be processed. In addition, care should be taken when processing the measurements, because locations with poor measurement quality typically exist. In this article a method will be developed to reduce the amount of measurements so that further processing is less time consuming. In addition, as a side effect of the data reduction method, poor quality measurements will be filtered and the overall SNR will improve. The method uses an iterative robust two-step spline approximation with an automatic model order determination procedure. The validation of the technique is performed both on scanning laser vibrometer measurements of a car door and a circuit board and on ESPI data.

Vanlanduit, S.; Guillaume, P.; Schoukens, J.

2004-07-01

346

Object-Based Building Extraction from High Resolution Satellite Imagery  

NASA Astrophysics Data System (ADS)

Automatic building extraction from high resolution satellite imagery is considered as an important field of research in remote sensing and machine vision. Many algorithms for extraction of buildings from satellite images have been presented so far. These algorithms mainly have considered radiometric, geometric, edge detection and shadow criteria approaches to perform the building extraction. In this paper, we propose a novel object based approach for automatic and robust detection and extraction of building in high spatial resolution images. To achieve this goal, we use stable and variable features together. Stable features are derived from inherent characteristics of building phenomenon and variable features are extracted using SEparability and THresholds analysis tool. The proposed method has been applied on a QuickBird imagery of an urban area in Isfahan city and visual validation demonstrates that the proposed method provides promising results.

Attarzadeh, R.; Momeni, M.

2012-07-01

347

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

348

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

349

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

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

2014-01-01

350

Measuring large-scale social networks with high resolution.  

PubMed

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

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

2014-01-01

351

Fabricating High-Resolution X-Ray Collimators  

NASA Technical Reports Server (NTRS)

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

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

2008-01-01

352

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

SciTech Connect

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

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

2010-05-05

353

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

354

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

355

Monitoring of vegetation coverage based on high-resolution images  

Microsoft Academic Search

Measurement of vegetation coverage on a small scale is the foundation for the monitoring of changes in vegetation coverage\\u000a and of the inversion model of monitoring vegetation coverage on a large scale by remote sensing. Using the object-oriented\\u000a analytical software, Definiens Professional 5, a new method for calculating vegetation coverage based on high-resolution images\\u000a (aerial photographs or near-surface photography) is

Li Zhang; Li-juan Li; Li-qiao Liang; Jiu-yi Li

2007-01-01

356

High resolution microstructural and microchemical analysis of zirconia eutectic interfaces  

SciTech Connect

The goal of the research performed here is to study and understand the nature of fine scale microchemical variation, on the order of the lattice periodicity, in ceramic oxides. To that end, during the past year, emphasis was placed on the selection of appropriate materials systems and their fabrication into samples suitable for study using advanced high resolution analytical electron microscopy (work to be performed in the coming year). The work concentrated on two materials systems.

Notis, M.R.

1992-01-28

357

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

358

High-Resolution Wind Measurements for Offshore Wind Energy Development  

NASA Technical Reports Server (NTRS)

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

Nghiem, Son V.; Neumann, Gregory

2011-01-01

359

ALOS-2 science program and high resolution SAR applications  

NASA Astrophysics Data System (ADS)

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

Shimada, M.; Osawa, Yuji

2012-11-01

360

High Resolution X-Ray Measurement on MST  

Microsoft Academic Search

A custom-built x-ray detector, with a 20 nanosecond shaping time, will provide a spectral measurement of photons in the 2 to 10 keV energy range. Output pulses from a shaping amplifier are directly digitized at 500 MHz to maximize spectral resolution. Each pulse can be fit to a Gaussian, and noise pulses are easily discriminated. This method is highly advantageous

M. W. Brookman; A. F. Almagri; D. J. Clayton; J. D. Lee; J. S. Sarff; Y. Diawara

2010-01-01

361

High spectral resolution remote sensing of canopy chemistry  

NASA Technical Reports Server (NTRS)

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

Aber, John D.; Martin, Mary E.

1995-01-01

362

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

NASA Technical Reports Server (NTRS)

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

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

1995-01-01

363

Need for high resolution in VUV Rydberg state spectroscopy  

NASA Technical Reports Server (NTRS)

The paper emphasizes the necessity of high energy resolution (resolving powers greater than 100,000) in VUV spectroscopic determinations of atomic and molecular Rydberg electronic structures. Attention is given to spectral observations of Rydberg levels in Ge I near the 4p 2P(0)1/2 limit, in Sr I near the 4d 2D3/2 limit, and in diatomic hydrogen halides (especially H I) below the X2Pi3/2 limit.

Ginter, M. L.; Ginter, D. S.; Brown, C. M.

1980-01-01

364

Pointed telescope subassembly for the UARS High Resolution Doppler Imager  

NASA Technical Reports Server (NTRS)

The Pointed Telescope Subassembly (PTS) consists of a telescope, its Coude relay optics, a two axis gimbal mechanism, and a cover/caging device. These components, their mechanisms, the requirements, and some of the trade-offs leading to the final design are described. The PTS supplies light to the interferometer of the High Resolution Doppler Imager to be used to study upper atmospheric wind velocity.

Renken, Robert D.

1987-01-01

365

Ultra-high-resolution small-animal SPECT imaging  

Microsoft Academic Search

The main subject of this thesis is the development of the first two in a series of dedicated ultra-high resolution Single Photon Emission Computed Tomography (SPECT) systems (U-SPECT-I and II) for the imaging of distributions of radio-isotope labeled tracers in small laboratory animals such as mice and rats. After an explanation of the history of pinhole imaging and the basics

F. van der Have

2007-01-01

366

High-resolution gamma-ray detectors for nuclear spectroscopy  

Microsoft Academic Search

Transition-edge sensor (TES) calorimeters are an attractive technology for precision measurements of electromagnetic radiation. However, in order to have a high-energy resolution detector, a small detector volume must be used, thereby limiting the count-rate and efficiency of the detector. As a result, many TES calorimeters must be operated simultaneously in order to achieve an appreciable detector count rate and stopping

Mark Forrest Cunningham

2002-01-01

367

Spectral analysis of high resolution temperature profiles in the stratosphere  

SciTech Connect

The authors present in this paper one of the first high resolution analysis of temperature profiles measured in the lower stratosphere. The temperature fluctuations level is shown to depend only on the static stability. Moreover, in the 12-1,500 m vertical wavelength range, the temperature spectrum has a mean slope around - 2.3, a value significantly above the - 3 saturated model value.

Cot, C.; Barat, J. (Service d' Aeronomie du CNRS, Verrieres le Buisson (France))

1989-10-01

368

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

NASA Technical Reports Server (NTRS)

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

1990-01-01

369

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

370

High-resolution optical spectroscopy of Praesepe white dwarfs  

Microsoft Academic Search

We present the results of a high-resolution optical spectroscopic study of nine white dwarf candidate members of Praesepe undertaken with the VLT and Ultraviolet and Visual Echelle Spectrograph. We find, contrary to a number of previous studies, that WD0836+201 (LB390, EG59) and WD0837+199 (LB393, EG61) are magnetic and non-magnetic white dwarfs, respectively. Subsequently, we determine the radial velocities for the

S. L. Casewell; P. D. Dobbie; R. Napiwotzki; M. R. Burleigh; M. A. Barstow; R. F. Jameson

2009-01-01

371

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

372

Comparison and analysis of fusion algorithms of high resolution imagery  

NASA Astrophysics Data System (ADS)

The fusion techniques have been developed quickly in recent years and become an important remote sensing research topic. This paper systematically discusses the technique used in pixel level image fusion including IHS transform, YIQ transform, HLS transform, HSV transform, PCA transform, HPF transform and wavelet transform image fusion method. Then a fusion experiment of IKONOS image is made to compares the different merging methods from spectral quality and the spatial quality in order to choose the suitable method for the high resolution image.

Dong, Guangjun; Huang, Xiaobo; Dai, Chenguang

2008-03-01

373

High resolution investigation of Nd3+-doped strontium lanthanum aluminate  

Microsoft Academic Search

Strontium lanthanum aluminates crystals (ASL) doped with Nd3+ with formula Sr1-xNdyLax-yMgxAl12-xO19 are interesting crystals for lasers operating in i.r. (~900 nm range) or blue spectral ranges. This paper uses high-resolution spectroscopy, at low temperatures, for investigation of the influence of composition and Nd3+ doping of ASL crystals on emission properties. Preliminary spectral characteristics of two non-equivalent centers were determined. From

Daniel Vivien; Gerard Aka; Aurelia Lupei; Voicu Lupei; Cristian Gheorghe

2004-01-01

374

High resolution images of Venus from ground-based radar  

NASA Technical Reports Server (NTRS)

The Goldstone Deep Space Station ground-based synthetic aperture radar system has been used to obtain radar images of Venus with resolutions of close to 1.3 km. Observations were made at 12.5 cm wavelength using circular polarization. From 12 days of observations during the 1986 inferior conjunction, three images have been selected for initial processing. The images show remarkable surface features including craters, ridges, and regions of high Fresnel reflectivity in the plains region.

Jurgens, R. F.; Slade, M. A.; Robinett, L.; Brokl, S.; Downs, G. S.

1988-01-01

375

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

376

High Resolution Electron Microscopy at the National Cancer Institute  

Cancer.gov

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

377

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

378

Quantification of Murine Pancreatic Tumors by High Resolution Ultrasound  

PubMed Central

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

Sastra, Stephen A.; Olive, Kenneth P.

2013-01-01

379

Multimodal microscopy with high resolution spectral focusing CARS  

NASA Astrophysics Data System (ADS)

In this work we describe a device that extends capabilities of multiphoton microscopes based on dual wavelength output femtosecond laser sources. CARS with 17cm-1 spectral resolution is experimentally demonstrated. Our approach is based on spectral focusing CARS. For pulse shaping of the pump and Stokes beams we utilize transmission gratings based stretcher. It allows the dispersion of the stretcher to be continuously adjusted in wide range. The best spectral resolution is achieved when the chirp rates in both pump and Stokes beam are matched. The device is automated. Any change in the beam path lengths due to the stretcher adjustment or wavelength tuning is compensated by the delay line. We incorporated into the device a computer controlled beam pointing stabilization system that compensates the beam pointing deviation due to dispersion in the system. High level of automation and computer control makes the operation of the device easy. We present CARS images of several samples that demonstrate high spectral resolution, high contrast and chemical selectivity.

Baldacchini, Tommaso; Zadoyan, Ruben

2014-02-01

380

Thin polymer etalon arrays for high-resolution photoacoustic imaging  

PubMed Central

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

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

2009-01-01

381

High Resolution Cluster Pressure Profile Measurements with MUSTANG and Bolocam  

NASA Astrophysics Data System (ADS)

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

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

2015-01-01

382

HIGH-RESOLUTION CH OBSERVATIONS OF TWO TRANSLUCENT MOLECULAR CLOUDS  

SciTech Connect

We present high-resolution (1.'3 x 1.'6) observations of the CH {sup 2}{pi}{sub 1/2} (F = 1-1) emission line at 3335 MHz in two high-latitude translucent clouds, MBM 3 and 40. At the assumed cloud distances, the angular resolution corresponds to {approx}0.05 pc, nearly an order of magnitude better than previous studies. Comparisons of the CH emission with previously obtained CO(1-0) data are difficult to interpret: the CO and CH line emission correlates in MBM 40 but not in MBM 3. In both clouds, there is a spatial offset in the peak emission, and perhaps in velocity for MBM 40. The difference in emission characteristics for the two tracers are noticeable in these two nearby clouds because of the high spatial resolution. Since both CH and CO are deemed to be reliable tracers of H{sub 2}, our results indicate that more care should be taken when using one of these tracers to determine the mass of a nearby molecular cloud.

Chastain, Raymond J. [Department of Physics and Astronomy, Louisiana State University, 368 Nicholson Hall, Tower Dr. Baton Rouge, LA 70803 (United States); Cotten, David; Magnani, Loris [Department of Physics and Astronomy, University of Georgia, Athens, GA 30602 (United States)

2010-01-15

383

High-resolution 3D relativistic MHD simulations of jets  

NASA Astrophysics Data System (ADS)

Relativistic magnetized jets are key elements in active galactic nuclei and in other astrophysical environments. Their structure and evolution involve a complex non-linear physics that can be approached by numerical studies only. Still, owing to a number of challenging computational aspects, only a few numerical investigations have been undertaken so far. In this paper, we present high-resolution three-dimensional numerical simulations of relativistic magnetized jets carrying an initially toroidal magnetic field. The presence of a substantial toroidal component of the field is nowadays commonly invoked and held responsible for the process of jet acceleration and collimation. We find that the typical nose cone structures, commonly observed in axisymmetric two-dimensional simulations, are not produced in the three-dimensional case. Rather, the toroidal field gives rise to strong current-driven kink instabilities leading to jet wiggling. However, it appears to be able to maintain a highly relativistic spine along its full length. By comparing low- and high-resolution simulations, we emphasize the impact of resolution on the jet dynamical properties.

Mignone, A.; Rossi, P.; Bodo, G.; Ferrari, A.; Massaglia, S.

2010-02-01

384

High-resolution optical imaging of the 'Frosty Leo' nebula  

NASA Technical Reports Server (NTRS)

High-resolution optical images have been obtained of IRAS 09371 + 1212 (the 'Frosty Leo' nebula). The images were taken with the Dominion Astrophysical Observatory/Canada-France-Hawaii Telescope (DAO/CFHT) High-Resolution Camera using broadband V and I filters and with an intermediate-band H-alpha filter. The red filters, particularly H-alpha show that the bipolar nebula is surrounded by a nearly spherical envelope of material approximately 30 sec in diameter. The high-resolution images allow a detailed study of changes in the nebular morphology with wavelength. The ansae remain stationary with wavelength, whereas the positions of the lobes and the position angle of the disk change with wavelength from the optical to the near infrared. These results suggest that the ejection process is colliminated by the disk, which has been processing with time. The possibility that the Frosty Leo nebula is not a post-asymptotic giant branch (AGB) star but a pre-main-sequence object formed in isolation from interstellar clouds is discussed.

Langill, Philip P.; Kwok, Sun; Hrivnak, Bruce J.

1994-01-01

385

High-resolution mapping of neuronal activity by thallium autometallography.  

PubMed

Different methods are available for imaging neuronal activity in the mammalian brain with a spatial resolution sufficiently high to detect activation patterns at the level of individual functional modules such as cortical columns. Severe difficulties exist, however, in visualizing the different degree of activity of each individual neuron within such a module, and mapping neuronal activity with a spatial resolution of single axons has remained impossible thus far. Here, we present a novel method for mapping neuronal activity that is able to visualize activation patterns with light and electron microscopical resolution. The method is based on the tight coupling of neuronal activity and potassium (K(+)) uptake. We have injected Mongolian gerbils with the K(+) analogue thallium (Tl(+)), stimulated the animals with pure tones of different frequencies and analyzed, by an autometallographic method, the Tl(+) distribution in the auditory cortex (AC). We find tonotopically organized columns of increased Tl(+)-uptake in AC. Within columns, the spatial patterns of neuronal activity as revealed by thallium autometallography are highly elaborated. Tl(+)-uptake differs in different layers, sublayers, and cell types, being especially high in large multipolar inhibitory interneurons in layer IV. A prominent feature of the columnar activation pattern is the presence of vertical modules of minicolumnar dimensions. Clusters of layer Vb pyramidal cells and their apical dendrite bundles are clearly visible in the center of the columns. PMID:15488413

Goldschmidt, Jürgen; Zuschratter, Werner; Scheich, Henning

2004-10-01

386

High Resolution Aircraft Scanner Mapping of Geothermal and Volcanic Areas  

SciTech Connect

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

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

1995-01-01

387

Pan-sharpening high spatial resolution ratio images using optimization  

NASA Astrophysics Data System (ADS)

Among most of current Pan-sharpening methods, resampling is generally required to make panchromatic (Pan) and multispectral (MS) images matched correctly pixel by pixel. However, few methods have focused on spectral distortions caused by shape distortions of real features during resampling. This paper proposes a new Pan-sharpening algorithm based on the gray and spectral relationships between Pan, MS and the fused images. In the algorithm, Pan-sharpening is defined as an optimization of a linear overdetermined system. It takes Pan and original MS images as input datasets without resampling. The Least square technique is applied to calculate the optimum values (quality fused images). QuickBird image datasets are tested, and the results are compared with the fused images of IHS, PCA and Gram-Schmidt using interpolated MS image. The result shows that the proposed method is more efficient than IHS, PCA and Gram-Schmidt in preserving spectral characteristics and increasing spatial resolution, especially for high spatial resolution ratio (SRR > 4:1, spatial resolution ratio is the ratio of the spatial resolution of MS image to that of Pan image.) images.

Li, Fangjun; Chen, Fu; Liu, Jianbo

2009-10-01

388

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

389

High-resolution free-electron laser spectroscopy  

SciTech Connect

The broad and continuous turnability of the rf linac-driven free-electron laser (FEL), coupled with its high power picosecond time structure, has greatly enhanced the research capabilities in the field of infrared spectroscopy. However, the duration of the optical pulses is often too long to probe ultrafast processes, and the spectral structure of the optical beam, with closely spaced longitudinal modes in a bandwidth determined by the Fourier transform of the short pulses, poses a significant limitation for experiments requiring high spectral resolution. The temporal resolution can be improved by operating the FEL with electron pulses whose energy varies linearly with time; the resulting optical pulses possess substantial frequency chirps and are susceptible to pulse compression in an external dispersive delay line. The spectral resolution can be enhanced by using an intracavity Michelson interferometer to couple successive optical pulses so that they build up from noise with a definite phase relationship; the longitudinal modes in the output beam are then separated by the rf frequency of the linac and can be individually filtered for applications in high resolution spectroscopy. This dissertation develops small signal analyses for each of these modes of operation, and reports the results of numerical pulse propagation simulations whose parameters were chosen to guide the design of feasible experiments on the Mark III FEL. Chirp-pulse simulations using modest energy chirps have demonstrated a x15 compression ratio at saturated power levels for 3.4 ps optical pulses at 3.35 [mu]m, and coupled pulse simulations have indicated substantial longitudinal mode reduction on microsecond time scales. The author also developed a derivation of FEL coupled mode equations using conventional mode locked laser theory, and solved them numerically in the frequency domain. Finally, the author reports the first operation of a Michelson mirror resonator on the Mark III FEL.

Szarmes, E.B.

1992-01-01

390

High-Resolution and Animal Imaging Instrumentation and Techniques  

NASA Astrophysics Data System (ADS)

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

Belcari, Nicola; Guerra, AlbertoDel

391

On a large time-step high resolution scheme  

NASA Technical Reports Server (NTRS)

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

Harten, A.

1986-01-01

392

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

393

DIRAC: A High Resolution Spectrometer for Pionium Detection  

E-print Network

The DIRAC spectrometer has been commissioned at CERN with the aim of detecting $\\pi^+ \\pi^-$ atoms produced by a 24 GeV/$c$ high intensity proton beam in thin foil targets. A challenging apparatus is required to cope with the high interaction rates involved, the triggering of pion pairs with very low relative momentum, and the measurement of the latter with resolution around 0.6 MeV/$c$. The general characteristics of the apparatus are explained and each part is described in some detail. The main features of the trigger system, data-acquisition, monitoring and setup performances are also given.

DIRAC Collaboration

2003-05-13

394

High-resolution gas chromatography/matrix isolation infrared spectrometry  

SciTech Connect

An apparatus is described that allows the collection, within a matrix of condensed inert gas, of the effluent compounds from a high-resolution gas chromatograph. Each collected compound is contained within an area typically 0.3 mm in diameter yielding a concomitant high level of infrared spectral absorbance per nanogram of sample. Tests demonstrate the level of infrared sensitivity, the achievement of matrix isolation of the sample molecules, and the maintenance of compound separation achieved by the gas chromatograph. Use of the apparatus is demonstrated for PAH, PCB, dioxin, and aliphatic hydrocarbon compounds. 15 references, 12 figures.

Reedy, G.T.; Ettinger, D.G.; Schneider, J.F.; Bourne, S.

1985-07-01

395

High resolution upgrade of the ATF damping ring BPM system  

SciTech Connect

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

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

2008-05-01

396

Measuring molecular flows with high-resolution stimulated Raman spectroscopy  

NASA Technical Reports Server (NTRS)

It is proposed to use high-resolution stimulated Raman spectroscopy to directly measure high-speed molecular flow velocities in wind tunnels and in combustive chambers. A feasibility study indicates that flow speeds from Mach 0.04 up may be measured with the proposed method using available laser systems. It is pointed out that the success of the proposed technique will make it possible to measure all interesting flow parameters, i.e., species concentration, temperature, and velocity, in a time of less than 1 microsecond at a repetition rate of 10,000/s using a single experimental arrangement.

She, C. Y.; Fairbank, W. M., Jr.; Exton, R. J.

1981-01-01

397

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; Kjær, Helle Astrid; Vallelonga, Paul; Azuma, Nobuhiko; Takata, Morimasa

2014-05-01

398

Development of a high-resolution surveillance camera with 520 TV lines  

Microsoft Academic Search

We have newly developed a high-resolution surveillance camera that has 520 TV lines horizontal resolution using a single-chip 410 k pixels color CCD. This camera realizes about 10% improvement of horizontal resolution compared with conventional camera having 470 TV lines horizontal resolution. This paper describes three technologies to improve horizontal resolution. These technologies can be also applied to a video

Y. Mori; S. Okada; T. Mise; H. Murata; E. Azuma

2001-01-01

399

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

400

A New Thermal Method for High-resolution Aquifer Characterization  

NASA Astrophysics Data System (ADS)

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

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

2011-12-01

401

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.

König, Karsten

2011-03-01

402

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

403

Photoswitchable Nanoparticles Enable High-Resolution Cell Imaging: PULSAR Microscopy  

SciTech Connect

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

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

2008-10-22

404

Parallelization and Algorithmic Enhancements of High Resolution IRAS Image Construction  

NASA Astrophysics Data System (ADS)

The Infrared Astronomical Satellite carried out a nearly complete survey of the infrared sky, and the survey data are important for the study of many astrophysical phenomena. However, many data sets at other wavelengths have higher resolutions than that of the co-added IRAS maps, and high resolution IRAS images are strongly desired both for their own information content and their usefulness in correlation studies. The HIRES program was developed by the Infrared Processing and Analysis Center (IPAC) to produce high resolution (~1') images from IRAS data using the Maximum Correlation Method (MCM). We describe the port of HIRES to the Intel Paragon, a massively parallel supercomputer, other software developments for mass production of HIRES images, and the IRAS Galaxy Atlas, a project to map the Galactic plane at 60 and 100 microns. Images produced from the MCM algorithm sometimes suffer from visible striping and ringing artifacts. Correcting detector gain offsets and using a Burg entropy metric in the reconstruction scheme were found to be effective in suppressing these artifacts. A variation of the destriping algorithm was used to subtract zodiacal emission. (SECTION: Computing and Data Analysis)

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

1996-06-01

405

Permafrost kinematics from high resolution stereophotogrammetry - Application and Restrictions  

NASA Astrophysics Data System (ADS)

The dynamics of geomorphological processes in cold high mountain environments are evident in the geometrical changes of periglacial landforms. Especially periglacial systems close to their boundaries react most sensitive to changes of external factors such as temperature. These changes are not only assessable by morphometric analyses of the landforms but also by focusing on variations in energy and sediment fluxes within the system. A holistic approach using complementary high resolution remote sensing systems as well as in situ measurements is not only able to detect and characterize morphological changes of the landforms but also to describe spatiotemporal variations and extraordinary changes such as acceleration or degradation. Multitemporal and multisensoral high resolution airborne stereo imagery (GSD < 0.5m) is used to obtain digital elevation models of a periglacial mountain slope in Switzerland. A comprehensive accuracy analysis of the digital elevation models shows their spatially diverse performance and helps to interpret derived results accordingly. The sensor systems show different performances which have to be considered when using their products for further quantitative assessments . The multitemporal data from the last two decades allows the identification and quantification of movement of slow moving landforms (frozen talus slopes and rockglaciers). Horizontal and vertical changes within the dynamic landforms are assessed and quantified during the different timesteps. Feature tracking and DEM differencing of the high resolution data show the spatial development and kinematic behavior of the landforms. Numerous geodetic measurements of very high accuracy (1-2 cm) complement the remote sensing products and give also a spatially restricted reference to their performance. Special attention is given to outstanding processes such as degradation of permafrost features and acceleration of processes manifested in these landforms (permafrost creep). The analysis of the extraordinary behavior yields to a better understanding of the controlling processes and parameters.

Mueller, Johann; Gaertner-Roer, Isabelle; Thee, Patrick; Ginzler, Christian

2013-04-01

406

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

NASA Technical Reports Server (NTRS)

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

Sepulveda, Cesar; Wilson, Robert; Seshadri, Suresh

2007-01-01

407

High-resolution infrared observations of active galactic nuclei  

NASA Astrophysics Data System (ADS)

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

Pott, Jörg-Uwe

2012-07-01

408

Towards high-resolution ptychographic x-ray diffraction microscopy  

NASA Astrophysics Data System (ADS)

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 ?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; Zettsu, Nobuyuki; Kohmura, Yoshiki; Senba, Yasunori; Ohashi, Haruhiko; Yamauchi, Kazuto; Ishikawa, Tetsuya

2011-06-01

409

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

410

High-resolution random-modulation cw lidar.  

PubMed

A high-resolution random-modulation continuous wave lidar for surface detection using a semiconductor laser diode is presented. The laser diode is intensity modulated with the pseudorandom binary sequence. Its enhanced resolution is achieved via interpolation and a novel front-end analog technique, lowering the requirement of the analog-to-digital converter sampling rate and the associated circuitry. Its mathematical model is presented, including the derivation of the signal-to-noise ratio and the distance standard deviation. Analytical and experimental results demonstrate its capability to achieve distance accuracy of less than 2?cm within 2.6?ms acquisition time, over distances ranging from 1 to 12?m. The laser diode emits 1.4?mW of optical power at a wavelength of 635?nm. PMID:21833124

Ai, Xiao; Nock, Richard; Rarity, John G; Dahnoun, Naim

2011-08-01

411

High-resolution random-modulation cw lidar  

NASA Astrophysics Data System (ADS)

A high-resolution random-modulation continuous wave lidar for surface detection using a semiconductor laser diode is presented. The laser diode is intensity modulated with the pseudorandom binary sequence. Its enhanced resolution is achieved via interpolation and a novel front-end analog technique, lowering the requirement of the analog-to-digital converter sampling rate and the associated circuitry. Its mathematical model is presented, including the derivation of the signal-to-noise ratio and the distance standard deviation. Analytical and experimental results demonstrate its capability to achieve distance accuracy of less than 2cm within 2.6ms acquisition time, over distances ranging from 1 to 12m. The laser diode emits 1.4mW of optical power at a wavelength of 635nm.

Ai, Xiao; Nock, Richard; Rarity, John G.; Dahnoun, Naim

2011-08-01

412

The sun and nearby stars - Microwave observations at high resolution  

NASA Technical Reports Server (NTRS)

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

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

1985-01-01

413

High Resolution, Single-Step Patterning of Silica Aerogels  

NASA Technical Reports Server (NTRS)

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

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

2003-01-01

414

High-resolution ultrasound imaging of the eye – a review  

PubMed Central

This report summarizes the physics, technology and clinical application of ultrasound biomicroscopy (UBM) of the eye, in which frequencies of 35 MHz and above provide over a threefold improvement in resolution compared with conventional ophthalmic ultrasound systems. UBM allows imaging of anatomy and pathology involving the anterior segment, including regions obscured by overlying optically opaque anatomic or pathologic structures. UBM provides diagnostically significant information in conditions such as glaucoma, cysts and neoplasms, trauma and foreign bodies. UBM also can provide crucial biometric information regarding anterior segment structures, including the cornea and its constituent layers and the anterior and posterior chambers. Although UBM has now been in use for over 15 years, new technologies, including transducer arrays, pulse encoding and combination of ultrasound with light, offer the potential for significant advances in high-resolution diagnostic imaging of the eye. PMID:19138310

Silverman, Ronald H

2009-01-01

415

High Resolution Infrared Spectroscopy of Allene -D4.  

NASA Astrophysics Data System (ADS)

Two parallel bands of allene-d(,4), (nu)(,6) (occurring at 1920.2289 cm('-1)) and (nu)(,5) (occurring at 2228.4133 cm('-1)), and the perpendicular band, (nu)(,8) (occurring at 2321.2484 cm('-1)), were recorded by using two spectrometers under high resolution. The combination band, (nu)(,2) + (nu)(,7), was measured also; the band origin is located at 2276.0053 cm('-1), rather distant from the previously reported one at 2267.0 cm('-1). Initially, by using the 4.5 m grating spectrometer, deconvolution of the spectra achieved a resolution of (TURN)0.007 cm('-1). Although the resolution was high, a detailed analysis of the K structure could not be obtained. Other measurements were carried out by using a BOMEM Fourier transform spectrometer. Deconvolution of the spectra achieved a resolution of (TURN)0.002 cm(' -1). This made it possible to resolve and analyze these bands in detail. Successful ground state and upper state analyses were completed from this data. Combining all the three bands together, a ground state analysis has resulted in better values of. (DIAGRAM, TABLE OR GRAPHIC OMITTED...PLEASE SEE DAI). than the previously published works on the same molecule by others. A set of accurate spectroscopic constants was obtained for each band. The spectrum of the (nu)(,8) band was analyzed in detail, including the perturbations. The perturbed states for (nu)(,8) were assigned as 2(nu)(,9) + (nu)(,10), (nu)(,2) + (nu)(,9) + (nu)(,11) and 2(nu)(,3) + (nu)(,4), and the spectroscopic constants for those perturbed states were calculated.

Rousan, Khetam Ibrahim Khasawinah

416

High-resolution mapping of motor vehicle carbon dioxide emissions  

NASA Astrophysics Data System (ADS)

A 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

417

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 for genetic mapping experiments in model organisms. Here we report the establishment of a high-density SNP map and high-throughput genotyping assays for Drosophila melanogaster. Our map comprises 27,367 SNPs in common

Cai, Long

418

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 70°S 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 71.9±5.8 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

419

Flexible micromirror linear array for high-resolution projection display  

NASA Astrophysics Data System (ADS)

The visual displays of contemporary military flight simulators lack adequate definition to represent scenes in basic fast-jet fighter tasks. For example, air-to-air and air-to-ground targets are not projected with sufficient contrast and resolution for a pilot to perceive aspect, aspect rate and object detail at real world slant ranges. Simulator display geometries require the development of ultra-high resolution projectors with greater than 20 megapixel resolution at 60 Hz frame rate. A new micromirror device has been developed to address this requirement; it is able to modulate light intensity in an analog fashion with switching times shorter than 5 ?s. When combined with a scanner, a microlaser and Schlieren optics, a linear array of these flexible micromirrors can display images composed of thousands of lines at a frame rate of 60 Hz. The approach selected for light modulation and the micromirror fabrication process flow are reviewed. Static and dynamic performances of these electrostatic MOEMS are described. Preliminary results following the integration of the described modulator into a projector prototype are reported. Developments toward a fully addressable 2000 × 1 flexible micromirror array are presented. The specifications and design of the CMOS circuit required to control this micromirror array are described. Packaging issues related to these large arrays are discussed.

Picard, Francis; Campillo, Celine; Pope, Timothy D.; Niall, Keith K.; Peppler, Philipp W.; Larouche, Carl; Jerominek, Hubert

2003-01-01

420

High energy resolution with transparent ceramic garnet scintillators  

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

421

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

422

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

423

Reconstruction of High Resolution Tongue Volumes from MRI  

PubMed Central

Magnetic resonance (MR) images of the tongue have been used in both clinical studies and scientific research to reveal tongue structure. In order to extract different features of the tongue and its relation to the vocal tract, it is beneficial to acquire three orthogonal image volumes—e.g., axial, sagittal, and coronal volumes. In order to maintain both low noise and high visual detail and minimize the blurred effect due to involuntary motion artifacts, each set of images is acquired with an in-plane resolution that is much better than the through-plane resolution. As a result, any one data set, by itself, is not ideal for automatic volumetric analyses such as segmentation, registration, and atlas building or even for visualization when oblique slices are required. This paper presents a method of super-resolution volume reconstruction of the tongue that generates an isotropic image volume using the three orthogonal image volumes. The method uses preprocessing steps that include registration and intensity matching and a data combination approach with the edge-preserving property carried out by Markov random field optimization. The performance of the proposed method was demonstrated on fifteen clinical datasets, preserving anatomical details and yielding superior results when compared with different reconstruction methods as visually and quantitatively assessed. PMID:23033324

Woo, Jonghye; Murano, Emi Z.; Stone, Maureen; Prince, Jerry L.

2013-01-01

424

High-resolution analytical TEM of nanostructured materials.  

PubMed

This paper briefly reviews the potential applicability of analytical transmission electron microscopy (TEM) to elucidate both structural and chemical peculiarities of materials at high lateral resolution. Examples of analytical TEM investigations performed by energy-dispersive X-ray spectroscopy (EDXS), electron energy loss spectroscopy (EELS), and energy-filtered TEM (EFTEM) are presented for different materials systems including metals, ceramics, and compound semiconductors. In particular, results are given of imaging the element distribution in the interface region between gamma matrix and gamma' precipitate in the nickel-based superalloy SC16 by energy-filtered TEM. For core-shell structured BaTiO(3) particles the chemical composition and even the chemical bonding were revealed by EELS at a resolution of about 1 nm. A sub-nanometer resolution is demonstrated by energy-selective images of the Ga distribution in the surrounding of (In,Ga)As quantum dots. Moreover, the element distribution in (Al,Ga)As/AlAs multilayers with linear concentration gradients in a range of about 10 nm was investigated by EDXS line-profile analyses and EFTEM. PMID:12397484

Schneider, R

2002-10-01

425

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

426

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

427

HiRES: the High-Resolution EUV Spectroheliometer  

NASA Astrophysics Data System (ADS)

The high-resolution EUV spectroheliometer (HiRES) is our first step towards the 0.1 arc sec angular resolution goal at EUV wavelengths. The HiRES instrument consists of a Gregory telescope with a 45-cm-diameter primary mirror, and an imaging EUV spectrometer, employing a single-reflection toric diffraction grating in a Rowland circle mounting and an imaging pulse-counting multi-anode microchannel array (MAMA) detector system. The MAMA detector covers the spectral range from 560 to 631 angstrom with a spectral resolution of 70 mAngstrom. A Pt/Ne lamp impresses a wavelength calibration spectrum on the upper part of the detector while the solar spectrum is recorded simultaneously on the lower part. The times-of-arrival and addresses of the detected photons are transmitted directly to the ground to allow correction of the SPARCS pointing jitter. The HiRES spectrometer slit is pointed to a specific location using real-time control of the SPARCS, and SPARCS can be commanded to execute a linear (push broom) scan across the sun. Two EUV photodiodes are used to measure the absolute sola irradiances and the atmospheric extinction profiles in wavelength bands centered at 304 angstrom and 584 angstrom respectively.

Timothy, J. Gethyn; Bergamini, Paolo; Bhattacharyya, Jagadish C.; Huber, Martin H.; Jain, Surendra K.; Naletto, Giampiero; Nicholls, Ralph W.; Nicolosi, Piergiorgio; Saxena, Ajay K.; Tondello, Giuseppe; Walker, Arthur B.

1997-10-01

428

Designing arrays for modern high-resolution methods  

SciTech Connect

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

Dowla, F.U.

1987-10-01

429

High-resolution retinal imaging with micro adaptive optics system  

NASA Astrophysics Data System (ADS)

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 3.6LP/mm, and the human eye wavefront aberration of 0.728 ? (?=785nm) 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.

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

2011-08-01

430

High resolution reversible color images on photonic crystal substrates.  

PubMed

When light is incident on a crystalline structure with appropriate periodicity, some colors will be preferentially reflected (Joannopoulos, J. D.; Meade, R. D.; Winn, J. N. Photonic crystals: molding the flow of light; Princeton University Press: Princeton, NJ, 1995; p ix, 137 pp). These photonic crystals and the structural color they generate represent an interesting method for creating reflective displays and drawing devices, since they can achieve a continuous color response and do not require back lighting (Joannopoulos, J. D.; Villeneuve, P. R.; Fan, S. H. Photonic crystals: Putting a new twist on light. Nature 1997, 386, 143-149; Graham-Rowe, D. Tunable structural colour. Nat. Photonics 2009, 3, 551-553.; Arsenault, A. C.; Puzzo, D. P.; Manners, I.; Ozin, G. A. Photonic-crystal full-colour displays. Nat. Photonics 2007, 1, 468-472; Walish, J. J.; Kang, Y.; Mickiewicz, R. A.; Thomas, E. L. Bioinspired Electrochemically Tunable Block Copolymer Full Color Pixels. Adv. Mater.2009, 21, 3078). Here we demonstrate a technique for creating erasable, high-resolution, color images using otherwise transparent inks on self-assembled photonic crystal substrates (Fudouzi, H.; Xia, Y. N. Colloidal crystals with tunable colors and their use as photonic papers. Langmuir 2003, 19, 9653-9660). Using inkjet printing, we show the ability to infuse fine droplets of silicone oils into the crystal, locally swelling it and changing the reflected color (Sirringhaus, H.; Kawase, T.; Friend, R. H.; Shimoda, T.; Inbasekaran, M.; Wu, W.; Woo, E. P. High-resolution inkjet printing of all-polymer transistor circuits. Science 2000, 290, 2123-2126). Multicolor images with resolutions as high as 200 ?m are obtained from oils of different molecular weights with the lighter oils being able to penetrate deeper, yielding larger red shifts. Erasing of images is done simply by adding a low vapor pressure oil which dissolves the image, returning the substrate to its original state. PMID:21766808

Kang, Pilgyu; Ogunbo, Samuel O; Erickson, David

2011-08-16

431

Theoretical performance analysis for CMOS based high resolution detectors.  

PubMed

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

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

2013-03-01

432

Synergy Between Ground Measurements and High Spatial Resolution Imagery to Validate Medium Spatial Resolution Land Surface Product  

NASA Astrophysics Data System (ADS)

Currently, several biophysical variables such as the Leaf Area Index (LAI), the Fraction of Absorbed Photosynthetically Active Radiation (fAPAR) and the surface albedo are derived from remote sensing observations acquired with medium spatial resolution sensors (250m to 7km). Because of their high temporal frequency and their important spatial coverage, these products are very useful to describe the mass and energy fluxes between the earth surface and the atmosphere. Since these variables are required for an important range of investigations and applications, it is important to assess their accuracy. Validation activity consists in evaluating by independent means the quality of the land surface products estimated from coarse resolution sensors. Validation methods consist in generating a ground truth map of these products at high spatial resolution. These maps are produced by using ground measurements of the biophysical variable and radiometric data from a high spatial resolution sensor (10m-30m). The relationship between a biophysical variable and radiometric imagery, called the transfer function, allows extending the local ground measurements to the entire high spatial resolution image. The resulting biophysical variable map is aggregated to be compared with the medium spatial resolution satellite biophysical products. Several geometrical issues influence the validation results: - the registration accuracy of the local ground measurements relative to the high spatial resolution image - the difference of spatial support between the ground measurement support and the high spatial resolution pixel - the registration accuracy between the high and medium resolution images - the point spread function (PSF) associated to the medium spatial resolution image This work proposes a methodology to account for these sources of uncertainties within the validation process. First, these problems are investigated at the field measurement scale. The registration accuracy between ground measurement located by GPS and high spatial resolution pixel is modeled by a Gaussian random variable. For each possible relative position, the ground measurement is related to the radiometric data for the surrounding area weighted by the ground measurement spatial support area. A Monte Carlo simulation scheme accounting for the positional accuracy provides the probability distribution function of the parameters defining the transfer function. Second, registration error is investigated when aggregated high spatial resolution image is compared with coarse resolution image. The registration error is minimized by getting the best geometrical match between the two images using correlation techniques. Finally, the importance of the PSF associated to the medium spatial resolution biophysical products is evaluated using data from MODIS and VEGETATION sensors. This investigation is applied to several validation sites expressing a range of spatial heterogeneity.

Garrigues, S.; Morisette, J.; Baret, F.; Privette, J.

2005-12-01

433

Saturn - high-resolution filtered image of Enceladus  

NASA Technical Reports Server (NTRS)

This high-resolution filtered image of Enceladus was made from several images obtained Aug. 25 by Voyager 2 from a range of 119,000 kilometers (74,000 miles). It shows further surface detail on this Saturnian moon (also viewed in the accompanying release P-23955C/BW, S-2-50, imaged about the same time). Enceladus is seen to resemble Jupiter's Galilean satellite Ganymede, which is, however, about 10 times larger. Faintly visible here in 'Saturnshine' is the hemisphere turned away from the sun. The Voyager project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

1981-01-01

434

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

435

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

436

Quantitative high-resolution melting analysis for detecting adulterations.  

PubMed

Admixtures of different plant species are a common problem in raw materials for medicinal use. Two exemplary assays were developed to admixtures in Helleborus niger with high-resolution melting analysis. HRM proved to be a very sensitive tool in detecting admixtures, able to detect a ratio of 1:1000 with unknown species, and of 1:200,000 with Veratrum nigrum. The example proves the ability of HRM for quantification in multiplex PCR. The method is not limited to detecting adulterations. It can also be used to quantify a specific target by integrating a second amplicon in the assay as internal standard. PMID:20946863

Mader, Eduard; Ruzicka, Joana; Schmiderer, Corinna; Novak, Johannes

2011-02-01

437

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

438

High Resolution Coude Echelle Spectroscopy of IX Per  

NASA Astrophysics Data System (ADS)

High resolution (R = 45000) Coude-Echelle spectra of IX Per has been obtained at TÜB?TAK National Observatory (TUG) of Turkey. IX Per has been known to be a single lined (SB1) spectroscopic binary having chromospheric activity. However, analyzed spectra of IX Per by KOREL disentangling method indicated that the system is a double lined (SB2) spectroscopic binary. Weaker lines from the secondary are discovered on the decomposed spectra. A preliminary orbit indicates that the mass ratio of the system is 0.64. The light contribution of the secondary is up to 10% in investigated spectral region. Circular orbit is sufficient to explain radial velocity variations.

Ak, N. Filiz; Eker, Z.; Ak, H.; Küçük, I.

2009-02-01

439