High Resolution Freeze and Thaw States Detection Using Combination of Sentinel 1A SAR and Passive Microwave Measurements

NASA Astrophysics Data System (ADS)

Azarderakhsh, M.; McDonald, K. C.; Norouzi, H.; Rebolledo, M. A.; Prakash, S.

2017-12-01

The freeze and thaw (FT) cycles in high-latitude regions have great impact on many biogeochemical transitions, hydrology and ecosystem especially in wetland areas. Passive and active microwave remote sensing data from satellite observations have been deployed in the past to define the status of the surface in terms of freeze and thaw. While many progresses have been made in this field, the limitations attached to such observations have hindered our ability to fully predict the change of surface state in the scale that is appropriate for the aforementioned applications. The transition between freeze and thaw states may occur frequently (even within a day) especially during shifts from cold to warm seasons and vice versa. Passive microwave sensors have different acquisition times, and data fusion of these sensors may provide a complete diurnal variation estimate of FT states. However, the coarse spatial resolution of these measurements may undermine their applicability. However, active microwave backscatter measurements from sensors such as Sentinel 1A and the Advanced Land Observing Satellite Phased Array L-Band SAR (ALOS PALSAR) can deliver high resolution information about wetlands and FT status. In this project, Synthetic Aperture Radar (SAR) c-band backscatter data from Sentinel 1 from April 2014 to June 2017 are deployed to detect high resolution freeze/thaw states and wetland areas. The contrasts between frozen and thawed seasons are used to define FT states after performing required radiometric corrections and calibrations. A method based on phase changes in polarized images is developed for different land cover types to maximize the accuracy of the detections. The aggregated (up-scaled) estimates from active measurements are compared to passive microwave-based FT product. The results of this method reveal that the estimates are relatively in good agreement with SNOw TELemetry (SNOTEL) ground measurements. Finally, a downscaling method is tried to link passive emissivity-based FT product to high resolution active FT estimates to increase the temporal frequency of the high-resolution Sentinel data. The results of this study contribute to better understanding sources of positive carbon and methane (CH4) feedback to the atmosphere.

High-Resolution Study of the Perturbation in the CO Triplet Band

NASA Astrophysics Data System (ADS)

Momona, M.; Kanamori, H.; Sakurai, K.

1993-05-01

Seven hundred absorption lines have been observed in the discharge plasma of He and CO in the 12600-12 800 cm-1 region with Doppler-limited resolution by a near-infrared diode laser spectrometer. Out of complex spectral patterns, more than 400 lines were assigned to the CO triplet band, d3Δ(v‧ = 2) - a3Π (v″ = 1). The upper state of this transition is known to be severely perturbed. The measurement of all the spin subbands of the 3Δ - 3Π transition allowed us to reanalyze the perturbation of the d3Δ (v = 2) state with the highly vibrationally excited state, v = 9, in the a3Π state. Diode laser spectroscopy with high sensitivity and Doppler-limited resolution revealed the overtone band transition from v = 1 to v = 9 within the a3Π state and the Λ-type doubling in the d3Δ state. Those interesting phenomena can be understood as a result of the perturbation and were successfully reproduced by the eigenvectors determined in this analysis.

High resolution in-operando microimaging of solar cells with pulsed electrically-detected magnetic resonance

NASA Astrophysics Data System (ADS)

Katz, Itai; Fehr, Matthias; Schnegg, Alexander; Lips, Klaus; Blank, Aharon

2015-02-01

The in-operando detection and high resolution spatial imaging of paramagnetic defects, impurities, and states becomes increasingly important for understanding loss mechanisms in solid-state electronic devices. Electron spin resonance (ESR), commonly employed for observing these species, cannot meet this challenge since it suffers from limited sensitivity and spatial resolution. An alternative and much more sensitive method, called electrically-detected magnetic resonance (EDMR), detects the species through their magnetic fingerprint, which can be traced in the device's electrical current. However, until now it could not obtain high resolution images in operating electronic devices. In this work, the first spatially-resolved electrically-detected magnetic resonance images (EDMRI) of paramagnetic states in an operating real-world electronic device are provided. The presented method is based on a novel microwave pulse sequence allowing for the coherent electrical detection of spin echoes in combination with powerful pulsed magnetic-field gradients. The applicability of the method is demonstrated on a device-grade 1-μm-thick amorphous silicon (a-Si:H) solar cell and an identical device that was degraded locally by an electron beam. The degraded areas with increased concentrations of paramagnetic defects lead to a local increase in recombination that is mapped by EDMRI with ∼20-μm-scale pixel resolution. The novel approach presented here can be widely used in the nondestructive in-operando three-dimensional characterization of solid-state electronic devices with a resolution potential of less than 100 nm.

A 4.5 km resolution Arctic Ocean simulation with the global multi-resolution model FESOM 1.4

NASA Astrophysics Data System (ADS)

Wang, Qiang; Wekerle, Claudia; Danilov, Sergey; Wang, Xuezhu; Jung, Thomas

2018-04-01

In the framework of developing a global modeling system which can facilitate modeling studies on Arctic Ocean and high- to midlatitude linkage, we evaluate the Arctic Ocean simulated by the multi-resolution Finite Element Sea ice-Ocean Model (FESOM). To explore the value of using high horizontal resolution for Arctic Ocean modeling, we use two global meshes differing in the horizontal resolution only in the Arctic Ocean (24 km vs. 4.5 km). The high resolution significantly improves the model's representation of the Arctic Ocean. The most pronounced improvement is in the Arctic intermediate layer, in terms of both Atlantic Water (AW) mean state and variability. The deepening and thickening bias of the AW layer, a common issue found in coarse-resolution simulations, is significantly alleviated by using higher resolution. The topographic steering of the AW is stronger and the seasonal and interannual temperature variability along the ocean bottom topography is enhanced in the high-resolution simulation. The high resolution also improves the ocean surface circulation, mainly through a better representation of the narrow straits in the Canadian Arctic Archipelago (CAA). The representation of CAA throughflow not only influences the release of water masses through the other gateways but also the circulation pathways inside the Arctic Ocean. However, the mean state and variability of Arctic freshwater content and the variability of freshwater transport through the Arctic gateways appear not to be very sensitive to the increase in resolution employed here. By highlighting the issues that are independent of model resolution, we address that other efforts including the improvement of parameterizations are still required.

Evaluation and development of unmanned aircraft (UAV) for UDOT needs.

DOT National Transportation Integrated Search

2012-05-01

This research involved the use of high-resolution aerial photography obtained from Unmanned Aerial Vehicles (UAV) to aid UDOT in monitoring and documenting State Roadway structures and associated issues. Using geo-referenced UAV high resolution aeria...

HIGH-RESOLUTION SPATIAL MODELING OF DAILY WEATHER ELEMENTS FOR A CATCHMENT IN THE OREGON CASCADE MOUNTAINS, UNITED STATES

EPA Science Inventory

High-quality, daily meteorological data at high spatial resolution are essential for a variety of hydrologic and ecological modeling applications that support environmental risk assessments and decision making. This paper describes the development, application, and assessment of ...

High-resolution synchrotron X-ray analysis of bioglass-enriched hydrogels.

PubMed

Gorodzha, Svetlana; Douglas, Timothy E L; Samal, Sangram K; Detsch, Rainer; Cholewa-Kowalska, Katarzyna; Braeckmans, Kevin; Boccaccini, Aldo R; Skirtach, Andre G; Weinhardt, Venera; Baumbach, Tilo; Surmeneva, Maria A; Surmenev, Roman A

2016-05-01

Enrichment of hydrogels with inorganic particles improves their suitability for bone regeneration by enhancing their mechanical properties, mineralizability, and bioactivity as well as adhesion, proliferation, and differentiation of bone-forming cells, while maintaining injectability. Low aggregation and homogeneous distribution maximize particle surface area, promoting mineralization, cell-particle interactions, and homogenous tissue regeneration. Hence, determination of the size and distribution of particles/particle agglomerates in the hydrogel is desirable. Commonly used techniques have drawbacks. High-resolution techniques (e.g., SEM) require drying. Distribution in the dry state is not representative of the wet state. Techniques in the wet state (histology, µCT) are of lower resolution. Here, self-gelling, injectable composites of Gellan Gum (GG) hydrogel and two different types of sol-gel-derived bioactive glass (bioglass) particles were analyzed in the wet state using Synchrotron X-ray radiation, enabling high-resolution determination of particle size and spatial distribution. The lower detection limit volume was 9 × 10(-5) mm(3) . Bioglass particle suspensions were also studied using zeta potential measurements and Coulter analysis. Aggregation of bioglass particles in the GG hydrogels occurred and aggregate distribution was inhomogeneous. Bioglass promoted attachment of rat mesenchymal stem cells (rMSC) and mineralization. © 2016 Wiley Periodicals, Inc.

High-Resolution Views of Io's Emakong Patera: Latest Galileo Imaging Results

NASA Technical Reports Server (NTRS)

Williams, D. A.; Keszthelyi, L. P.; Davies, A. G.; Greeley, R.; Head, J. W., III

2002-01-01

This presentation will discuss analyses of the latest Galileo SSI (solid state imaging) high-resolution images of the Emakong lava channels and flow field on Jupiter's moon Io. Additional information is contained in the original extended abstract.

DETERMINATION OF 2,3,7,8 CHLORINE-SUBSTITUTED DIBENZO-P-DIOXINS AND FURANS AT THE PART PER TRILLION LEVEL IN UNITED STATES BEEF FAT USING HIGH-RESOLUTION GAS CHROMATOGRAPHY/HIGH-RESOLUTION MASS SPECTROMETRY

EPA Science Inventory

As part of the U.S. EPA Dioxin Reassessment Program, the 2,3,7,8-chlorine-substituted dibenzo-p-dioxins and furans were measured at part per trillion (ppt) levels in beef fat collected from slaughter facilities in the United States. This is the first statistically designed natio...

High-resolution internal state control of ultracold 23Na87Rb molecules

NASA Astrophysics Data System (ADS)

Guo, Mingyang; Ye, Xin; He, Junyu; Quéméner, Goulven; Wang, Dajun

2018-02-01

We report the full internal state control of ultracold 23Na87Rb molecules, including vibrational, rotational, and hyperfine degrees of freedom. Starting from a sample of weakly bound Feshbach molecules, we realize the creation of molecules in single hyperfine levels of both the rovibrational ground and excited states with a high-efficiency and high-resolution stimulated Raman adiabatic passage. This capability brings broad possibilities for investigating ultracold polar molecules with different chemical reactivities and interactions with a single molecular species. Moreover, starting from the rovibrational and hyperfine ground state, we achieve rotational and hyperfine control with one- and two-photon microwave spectroscopy to reach levels not accessible by the stimulated Raman transfer. The combination of these two techniques results in complete control over the internal state of ultracold polar molecules, which paves the way to study state-dependent molecular collisions and state-controlled chemical reactions.

Adaptive optics high-resolution IR spectroscopy with silicon grisms and immersion gratings

NASA Astrophysics Data System (ADS)

Ge, Jian; McDavitt, Daniel L.; Chakraborty, Abhijit; Bernecker, John L.; Miller, Shane

2003-02-01

The breakthrough of silicon immersion grating technology at Penn State has the ability to revolutionize high-resolution infrared spectroscopy when it is coupled with adaptive optics at large ground-based telescopes. Fabrication of high quality silicon grism and immersion gratings up to 2 inches in dimension, less than 1% integrated scattered light, and diffraction-limited performance becomes a routine process thanks to newly developed techniques. Silicon immersion gratings with etched dimensions of ~ 4 inches are being developed at Penn State. These immersion gratings will be able to provide a diffraction-limited spectral resolution of R = 300,000 at 2.2 micron, or 130,000 at 4.6 micron. Prototype silicon grisms have been successfully used in initial scientific observations at the Lick 3m telescope with adaptive optics. Complete K band spectra of a total of 6 T Tauri and Ae/Be stars and their close companions at a spectral resolution of R ~ 3000 were obtained. This resolving power was achieved by using a silicon echelle grism with a 5 mm pupil diameter in an IR camera. These results represent the first scientific observations conducted by the high-resolution silicon grisms, and demonstrate the extremely high dispersing power of silicon-based gratings. New discoveries from this high spatial and spectral resolution IR spectroscopy will be reported. The future of silicon-based grating applications in ground-based AO IR instruments is promising. Silicon immersion gratings will make very high-resolution spectroscopy (R > 100,000) feasible with compact instruments for implementation on large telescopes. Silicon grisms will offer an efficient way to implement low-cost medium to high resolution IR spectroscopy (R ~ 1000-50000) through the conversion of existing cameras into spectrometers by locating a grism in the instrument's pupil location.

High-resolution synchrotron infrared spectroscopy of acrolein: The vibrational levels between 700 and 820 cm-1

NASA Astrophysics Data System (ADS)

McKellar, A. R. W.; Billinghurst, B. E.

2015-09-01

The weak combination bands ν12 + ν18 and ν17 + ν18 of trans-acrolein in the 700-760 cm-1 region are observed at high resolution (<0.001 cm-1) using spectra obtained at the Canadian Light Source synchrotron radiation facility. A detailed rotational analysis of the 121181 and 171181 upper states is made which includes the nearby perturbing states 185, 132181, and 131183. Taking the results of this 5-state fit, together with earlier results on lower lying vibrations, we now have experimental characterization for all 15 excited vibrational states of acrolein lying below 820 cm-1.

A ultra-small-angle self-mixing sensor system with high detection resolution and wide measurement range

NASA Astrophysics Data System (ADS)

Yang, Bo; Wang, Dehui; Zhou, Lin; Wu, Shuang; Xiang, Rong; Zhang, Wenhua; Gui, Huaqiao; Liu, Jianguo; Wang, Huanqing; Lu, Liang; Yu, Benli

2017-06-01

The self-mixing technique based on the traditional reflecting mirror has been demonstrated with great merit for angle sensing applications. Here we demonstrate a modified self-reflection-mixing angle measurement system by combine a right-angle prism to self-mixing angle measurement. In our system, the wavelength is crucial to the angle measurement resolution. For a microchip solid-state laser, the measurement resolution can reach 0.49 mrad, while the resolution for the He-Ne laser is 0.53 mrad. In addition, the ranges in the system with the microchip solid-state laser and He-Ne laser are up to 22 mrad and 24.9 mrad respectively. This modified angle measurement system effectively combines the advantage of self-mixing measurement system with a compact structure, providing interesting features such as of high requisition of resolution and precision.

Temporal reliability of ultra-high field resting-state MRI for single-subject sensorimotor and language mapping.

PubMed

Branco, Paulo; Seixas, Daniela; Castro, São Luís

2018-03-01

Resting-state fMRI is a well-suited technique to map functional networks in the brain because unlike task-based approaches it requires little collaboration from subjects. This is especially relevant in clinical settings where a number of subjects cannot comply with task demands. Previous studies using conventional scanner fields have shown that resting-state fMRI is able to map functional networks in single subjects, albeit with moderate temporal reliability. Ultra-high resolution (7T) imaging provides higher signal-to-noise ratio and better spatial resolution and is thus well suited to assess the temporal reliability of mapping results, and to determine if resting-state fMRI can be applied in clinical decision making including preoperative planning. We used resting-state fMRI at ultra-high resolution to examine whether the sensorimotor and language networks are reliable over time - same session and one week after. Resting-state networks were identified for all subjects and sessions with good accuracy. Both networks were well delimited within classical regions of interest. Mapping was temporally reliable at short and medium time-scales as demonstrated by high values of overlap in the same session and one week after for both networks. Results were stable independently of data quality metrics and physiological variables. Taken together, these findings provide strong support for the suitability of ultra-high field resting-state fMRI mapping at the single-subject level. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Ultra high resolution molecular beam cars spectroscopy with application to planetary atmospheric molecules

NASA Technical Reports Server (NTRS)

Byer, R. L.

1982-01-01

The measurement of high resolution pulsed and continuous wave (CW) coherent anti-Stokes Raman spectroscopy (CARS) measurements in pulsed and steady state supersonic expansions were demonstrated. Pulsed molecular beam sources were characterized, and saturation of a Raman transition and, for the first time, the Raman spectrum of a complex molecular cluster were observed. The observation of CW CARS spectra in a molecular expansion and the effects of transit time broadening is described. Supersonic expansion is established as a viable technique for high resolution Raman spectroscopy of cold molecules with resolutions of 100 MH2.

Spectroscopy of molecules in very high rotational states using an optical centrifuge.

PubMed

Yuan, Liwei; Toro, Carlos; Bell, Mack; Mullin, Amy S

2011-01-01

We have developed a high power optical centrifuge for measuring the spectroscopy of molecules in extreme rotational states. The optical centrifuge has a pulse energy that is more than 2 orders of magnitude greater than in earlier instruments. The large pulse energy allows us to drive substantial number densities of molecules to extreme rotational states in order to measure new spectroscopic transitions that are not accessible with traditional methods. Here we demonstrate the use of the optical centrifuge for measuring IR transitions of N2O from states that have been inaccessible until now. In these studies, the optical centrifuge drives N2O molecules into states with J ~ 200 and we use high resolution transient IR probing to measure the appearance of population in states with J = 93-99 that result from collisional cooling of the centrifuged molecules. High resolution Doppler broadened line profile measurements yield information about the rotational and translational energy distributions in the optical centrifuge.

High-resolution Bio-Argo and Argo Measurements to Reveal Specific Oceanic Processes.

NASA Astrophysics Data System (ADS)

Poteau, A.; Claustre, H.; Briggs, N.; D'Ortenzio, F.; Schmechtig, C.; Prieur, L. M.; Boss, E.

2016-02-01

Together with temperature and salinity measurements, Bio-Argo profiling floats now measure a significant range of biogeochemical (e.g. O2, NO3) and bio-optical variables (Chla, backscattering coefficient and radiometry). To transmit the very large amount of data acquired by this new generation of floats, it was required to substitute the Argos telemetry (Argo program) with iridium telemetry. The obvious consequence is not only a much greater flexibly on data transmission but also on data acquisition thanks to the two-way communication allowed by iridium. Our group has now deployed and managed over 100 Bio-Argo floats of this type. In particular we have set up high-resolution mode of acquisition for certain periods of time or for dedicated portions of the water column. Here we illustrate with three examples the potential of conducting high-resolution measurement to identify and explore certain oceanic processes. (1) High resolution measurements of pressure, temperature and salinity (every 2 s) when the float is finishing its ascent (without any pump action) in the upper 10 m layer are analyzed with respect to sea state. We particularly focus on the study of the speed anomaly as compared to a nominal speed expected for a calm sea state. By comparison between speed anomaly of a float in the Mediterranean Sea and concurrent sea state measurements by a weather buoy in the same area, we suggest that float behaviour can be an indicator of sea state. (2) Each year, in response to springtime phytoplankton blooms, the resolution of bio-optical variables (backscattering and Chla) in the top 1000 m was increased to at least 1 m (every 10 s) for all floats in the North Atlantic and Southern Ocean. This resolution allowed accurate estimation of the concentration of large phytoplankton aggregates and revealed systematic differences in bulk aggregate sinking rate between ocean basins. (3) Finally we continuously record all the variables at a 10 min resolution during the float drift at 1000m. This allows us to characterize some events at this depth that can be related to bottom currents, high mixing or massive export of aggregates.

A ``Cyber Wind Facility'' for HPC Wind Turbine Field Experiments

NASA Astrophysics Data System (ADS)

Brasseur, James; Paterson, Eric; Schmitz, Sven; Campbell, Robert; Vijayakumar, Ganesh; Lavely, Adam; Jayaraman, Balaji; Nandi, Tarak; Jha, Pankaj; Dunbar, Alex; Motta-Mena, Javier; Craven, Brent; Haupt, Sue

2013-03-01

The Penn State ``Cyber Wind Facility'' (CWF) is a high-fidelity multi-scale high performance computing (HPC) environment in which ``cyber field experiments'' are designed and ``cyber data'' collected from wind turbines operating within the atmospheric boundary layer (ABL) environment. Conceptually the ``facility'' is akin to a high-tech wind tunnel with controlled physical environment, but unlike a wind tunnel it replicates commercial-scale wind turbines operating in the field and forced by true atmospheric turbulence with controlled stability state. The CWF is created from state-of-the-art high-accuracy technology geometry and grid design and numerical methods, and with high-resolution simulation strategies that blend unsteady RANS near the surface with high fidelity large-eddy simulation (LES) in separated boundary layer, blade and rotor wake regions, embedded within high-resolution LES of the ABL. CWF experiments complement physical field facility experiments that can capture wider ranges of meteorological events, but with minimal control over the environment and with very small numbers of sensors at low spatial resolution. I shall report on the first CWF experiments aimed at dynamical interactions between ABL turbulence and space-time wind turbine loadings. Supported by DOE and NSF.

Plant respirometer enables high resolution of oxygen consumption rates

NASA Technical Reports Server (NTRS)

Foster, D. L.

1966-01-01

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krishnan, Venkat; Cole, Wesley

This poster is based on the paper of the same name, presented at the IEEE Power & Energy Society General Meeting, July18, 2016. Power sector capacity expansion models (CEMs) have a broad range of spatial resolutions. This paper uses the Regional Energy Deployment System (ReEDS) model, a long-term national scale electric sector CEM, to evaluate the value of high spatial resolution for CEMs. ReEDS models the United States with 134 load balancing areas (BAs) and captures the variability in existing generation parameters, future technology costs, performance, and resource availability using very high spatial resolution data, especially for wind and solarmore » modeled at 356 resource regions. In this paper we perform planning studies at three different spatial resolutions - native resolution (134 BAs), state-level, and NERC region level - and evaluate how results change under different levels of spatial aggregation in terms of renewable capacity deployment and location, associated transmission builds, and system costs. The results are used to ascertain the value of high geographically resolved models in terms of their impact on relative competitiveness among renewable energy resources.« less

High-resolution infrared spectroscopy of the asymmetric NO stretch band of jet-cooled nitromethane and assignment of the lowest four torsional states

DOE PAGES

Dawadi, Mahesh B.; Degliumberto, Lou; Perry, David S.; ...

2017-08-10

We used a high-throughput CW slit-jet apparatus coupled to a high-resolution FTIR to record the asymmetric NO stretch band of nitromethane. The b-type band, including torsionally excited states with m ≤ 3, has been assigned for Ka" ≤ 10, J" ≤ 20. The ground state combination differences derived from these assigned levels were fit with the RAM36 program to give an RMS deviation of 0.0006 cm -1. The band origin is 1583.0 (±0.1) cm -1 and the torsional level spacing is nearly identical to that in the ground state. The upper state levels are split into multiplets by perturbations. Wemore » also fit a subset of the available upper state combination differences for m = 0, Ka' ≤ 7, J' ≤ 10 with the same program, but with rather poorer precision (0.01 cm -1) than for the ground state.« less

High-resolution infrared spectroscopy of the asymmetric NO stretch band of jet-cooled nitromethane and assignment of the lowest four torsional states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dawadi, Mahesh B.; Degliumberto, Lou; Perry, David S.

We used a high-throughput CW slit-jet apparatus coupled to a high-resolution FTIR to record the asymmetric NO stretch band of nitromethane. The b-type band, including torsionally excited states with m ≤ 3, has been assigned for Ka" ≤ 10, J" ≤ 20. The ground state combination differences derived from these assigned levels were fit with the RAM36 program to give an RMS deviation of 0.0006 cm -1. The band origin is 1583.0 (±0.1) cm -1 and the torsional level spacing is nearly identical to that in the ground state. The upper state levels are split into multiplets by perturbations. Wemore » also fit a subset of the available upper state combination differences for m = 0, Ka' ≤ 7, J' ≤ 10 with the same program, but with rather poorer precision (0.01 cm -1) than for the ground state.« less

High-resolution infrared spectroscopy of the asymmetric NO stretch band of jet-cooled nitromethane and assignment of the lowest four torsional states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dawadi, Mahesh B.; Degliumberto, Lou; Perry, David S.

A high-throughput CW slit-jet apparatus coupled to a high-resolution FTIR was used to record the asymmetric NO stretch band of nitromethane. The b-type band, including torsionally excited states with m ≤ 3, has been assigned for Ka" ≤ 10, J" ≤ 20. The ground state combination differences derived from these assigned levels were fit with the RAM36 program to give an RMS deviation of 0.0006 cm-1. The band origin is 1583.0 (+/- 0.1) cm-1 and the torsional level spacing is nearly identical to that in the ground state. The upper state levels are split into multiplets by perturbations. A subsetmore » of the available upper state combination differences for m = 0, Ka' ≤ 7, J' ≤ 10 were fit with the same program, but with rather poorer precision (0.01 cm-1) than for the ground state.« less

High-resolution infrared spectroscopy of the asymmetric NO stretch band of jet-cooled nitromethane and assignment of the lowest four torsional states

NASA Astrophysics Data System (ADS)

Dawadi, Mahesh B.; Degliumberto, Lou; Perry, David S.; Mettee, Howard D.; Sams, Robert L.

2018-01-01

A high-throughput CW slit-jet apparatus coupled to a high-resolution FTIR was used to record the asymmetric NO stretch band of nitromethane. The b-type band, including torsionally excited states with m ≤ 3, has been assigned for Ka″ ≤ 10, J″ ≤ 20. The ground state combination differences derived from these assigned levels were fit with the RAM36 program to give an RMS deviation of 0.0006 cm-1. The band origin is 1583.0 (±0.1) cm-1 and the torsional level spacing is nearly identical to that in the ground state. The upper state levels are split into multiplets by perturbations. A subset of the available upper state combination differences for m = 0, Ka‧ ≤ 7, J‧ ≤ 10 were fit with the same program, but with rather poorer precision (0.01 cm-1) than for the ground state.

Forest biomass estimated from MODIS and FIA data in the Lake States: MN, WI and MI, USA

Treesearch

Daolan Zheng; Linda S. Heath; Mark J. Ducey

2007-01-01

This study linked the Moderate Resolution Imaging Spectrometer and USDA Forest Service, Forest Inventory and Analysis (FIA) data through empirical models established using high-resolution Landsat Enhanced Thematic Mapper Plus observations to estimate aboveground biomass (AGB) in three Lake States in the north-central USA. While means obtained from larger sample sizes...

Absolute single-photoionization cross sections of Se 2 + : Experiment and theory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Macaluso, D. A.; Aguilar, A.; Kilcoyne, A. L. D.

2015-12-28

Absolute single-photoionization cross-section measurements for Se 2+ ions were performed at the Advanced Light Source at Lawrence Berkeley National Laboratory using the merged-beams photo-ion technique. Measurements were made at a photon energy resolution of 24 ± 3 meV in the photon energy range 23.5-42.5 eV, spanning the ground state and low-lying metastable state ionization thresholds. Here, to clearly resolve the resonant structure near the ground-state threshold, high-resolution measurements were made from 30.0 to 31.9 eV at a photon energy resolution of 6.7 ± 0.7 meV. Numerous resonance features observed in the experimental spectra are assigned and their energies and quantummore » defects tabulated. The high-resolution cross-section measurements are compared with large-scale, state-of-the-art theoretical cross-section calculations obtained from the Dirac Coulomb R -matrix method. Suitable agreement is obtained over the entire photon energy range investigated. In conclusion, these results are an experimental determination of the absolute photoionization cross section of doubly ionized selenium and include a detailed analysis of the photoionization resonance spectrum of this ion.« less

High resolution FTIR spectroscopy of the ν7 band of CD3CCH

NASA Astrophysics Data System (ADS)

Pal, Ayan Kumar; Kshirsagar, R. J.

2018-03-01

The high-resolution Fourier transform spectrum of propyne-d3 (CD3CCH) at room temperature has been recorded in the region of the ν7 band (950-1200 cm-1) at an apodized resolution of 0.004 cm-1. About 2400 lines consisting of a total of 25 sub-bands ranging from KΔK = -13 to 12 have been assigned in the ν7 band of CD3CCH. In the fitting analysis, the ν4 = 1 state to which transitions have not been identified in the experimental spectrum included as a "shadow" state. The data have been analyzed taking into account of the strong x-y Coriolis interaction of the ν7 = 1 state with the ν4 = 1 state. l-type interactions between the ± l components of the ν7 = 1 state, and a weak k-type doubling interaction between ν7 = 1 and ν4 = 1 states have been included in the analysis. The vibration-rotation transitions for K ≥ 8 show fairly large amount of deviation and most likely interacted by other nearby states. The transitions upto K = 7 and Jmax = 61 could be fitted with a standard deviation of 0.0007 cm-1.

High-Resolution Vibration-Rotation Spectroscopy of CO[subscript 2]: Understanding the Boltzmann Distribution

ERIC Educational Resources Information Center

Castle, Karen J.

2007-01-01

In this undergraduate physical chemistry laboratory experiment, students acquire a high-resolution infrared absorption spectrum of carbon dioxide and use their data to show that the rotational-vibrational state populations follow a Boltzmann distribution. Data are acquired with a mid-infrared laser source and infrared detector. Appropriate…

The Application of High-Resolution Electron Microscopy to Problems in Solid State Chemistry: The Exploits of a Peeping TEM.

ERIC Educational Resources Information Center

Eyring, LeRoy

1980-01-01

Describes methods for using the high-resolution electron microscope in conjunction with other tools to reveal the identity and environment of atoms. Problems discussed include the ultimate structure of real crystalline solids including defect structure and the mechanisms of chemical reactions. (CS)

Assignment and Analysis of the NO2 In-Plane Rock Band of Nitromethane Recorded by High-Resolution FTIR Synchrotron Spectroscopy

NASA Astrophysics Data System (ADS)

Dawadi, Mahesh B.; Perry, David S.; Twagirayezu, Sylvestre; Billinghurst, Brant E.

2014-06-01

The high-resolution rotationally resolved Fourier Transform Far-infrared spectrum of the NO2 in plane-rock band (440-510 cm-1) of nitromethane (CH3NO2) has been recorded using the Far-Infrared Beamline at the Canadian Light Source, with a resolution of 0.00096 cm-1. More than 1500 transitions lines have been assigned for ' = 0; {_a}' {≤ 7}; ' {≤ 50}; using an automated ground state combination difference program together with the traditional Loomis Wood approach. Transitions involving ' = 0; {_a}' {≤7}; ' {≤ 20}; in the upper vibrational state are fit using the six-fold torsion-rotation program developed by Ilyushin et.al. The torsion-rotation energy pattern in the lowest torsional state ( ' = 0) of the upper vibrational state is similar to that of the vibrational ground state. C. F. Neese., An Interactive Loomis-Wood Package, V2.0, {56th},OSU Interanational Symposium on Molecular Spectroscopy (2001). V. V. Ilyushin, Z. Kisiel, L. Pszczolkowski, H. Mader, and J. T. Hougen, M. Mol. Spectrosc., 259, 26, (2010).

High resolution spectroscopic study of Be Λ 10

DOE PAGES

Gogami, T.; Chen, C.; Kawama, D.; ...

2016-03-10

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

Slow Photoelectron Velocity-Map Imaging of Cryogenically Cooled Anions

NASA Astrophysics Data System (ADS)

Weichman, Marissa L.; Neumark, Daniel M.

2018-04-01

Slow photoelectron velocity-map imaging spectroscopy of cryogenically cooled anions (cryo-SEVI) is a powerful technique for elucidating the vibrational and electronic structure of neutral radicals, clusters, and reaction transition states. SEVI is a high-resolution variant of anion photoelectron spectroscopy based on photoelectron imaging that yields spectra with energy resolution as high as 1-2 cm‑1. The preparation of cryogenically cold anions largely eliminates hot bands and dramatically narrows the rotational envelopes of spectral features, enabling the acquisition of well-resolved photoelectron spectra for complex and spectroscopically challenging species. We review the basis and history of the SEVI method, including recent experimental developments that have improved its resolution and versatility. We then survey recent SEVI studies to demonstrate the utility of this technique in the spectroscopy of aromatic radicals, metal and metal oxide clusters, nonadiabatic interactions between excited states of small molecules, and transition states of benchmark bimolecular reactions.

High resolution spectroscopic study of Be10Lambda;

NASA Astrophysics Data System (ADS)

Gogami, T.; Chen, C.; Kawama, D.; Achenbach, P.; Ahmidouch, A.; Albayrak, I.; Androic, D.; Asaturyan, A.; Asaturyan, R.; Ates, O.; Baturin, P.; Badui, R.; Boeglin, W.; Bono, J.; Brash, E.; Carter, P.; Chiba, A.; Christy, E.; Danagoulian, S.; de Leo, R.; Doi, D.; Elaasar, M.; Ent, R.; Fujii, Y.; Fujita, M.; Furic, M.; Gabrielyan, M.; Gan, L.; Garibaldi, F.; Gaskell, D.; Gasparian, A.; Han, Y.; Hashimoto, O.; Horn, T.; Hu, B.; Hungerford, Ed. V.; Jones, M.; Kanda, H.; Kaneta, M.; Kato, S.; Kawai, M.; Khanal, H.; Kohl, M.; Liyanage, A.; Luo, W.; Maeda, K.; Margaryan, A.; Markowitz, P.; Maruta, T.; Matsumura, A.; Maxwell, V.; Mkrtchyan, A.; Mkrtchyan, H.; Nagao, S.; Nakamura, S. N.; Narayan, A.; Neville, C.; Niculescu, G.; Niculescu, M. I.; Nunez, A.; Nuruzzaman, Okayasu, Y.; Petkovic, T.; Pochodzalla, J.; Qiu, X.; Reinhold, J.; Rodriguez, V. M.; Samanta, C.; Sawatzky, B.; Seva, T.; Shichijo, A.; Tadevosyan, V.; Tang, L.; Taniya, N.; Tsukada, K.; Veilleux, M.; Vulcan, W.; Wesselmann, F. R.; Wood, S. A.; Yamamoto, T.; Ya, L.; Ye, Z.; Yokota, K.; Yuan, L.; Zhamkochyan, S.; Zhu, L.; Hksjlab E05-115 Collaboration

2016-03-01

Spectroscopy of a Be10Lambda; hypernucleus was carried out at JLab Hall C using the (e ,e'K+) reaction. A new magnetic spectrometer system (SPL+HES+HKS), specifically designed for high resolution hypernuclear spectroscopy, was used to obtain an energy spectrum with a resolution of ˜0.78 MeV (FWHM). The well-calibrated spectrometer system of the present experiment using p (e ,e'K+)Λ ,Σ0 reactions allowed us to determine the energy levels; and the binding energy of the ground-state peak (mixture of 1- and 2- states) was found to be BΛ=8.55 ±0.07 (stat . ) ±0.11 (sys . ) MeV. The result indicates that the ground-state energy is shallower than that of an emulsion study by about 0.5 MeV which provides valuable experimental information on the charge symmetry breaking effect in the Λ N interaction.

Moon Mineralogy Mapper: Unlocking the Mysteries of the Moon

NASA Technical Reports Server (NTRS)

Runyon, Cassandra

2006-01-01

Moon Mineralogy Mapper (M3) is a state-of-the-art high spectral resolution imaging spectrometer that will characterize and map the mineral composition of the Moon. The M3 instrument will be flown on Chandrayaan-I, the Indian Space Research Organization (ISRO) mission to be launched in March 2008. The Moon is a cornerstone to understanding early solar system processes. M3 high-resolution compositional maps will dramatically improve our understanding about the early evolution of the terrestrial planets and will provide an assessment of lunar resources at high spatial resolution.

The construction of a high resolution crystal backscattering spectrometer HERMES I

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larese, J.Z.

There is a need in the United States for a state-of-the-art, cold-neutron, crystal backscattering spectrometer (CBS) designed to investigate the structure and dynamics of condensed matter systems by the simultaneous utilization of long wavelength elastic diffraction and high-energy-resolution inelastic scattering. Cold neutron spectroscopy with CBS-type instruments has already made many important contributions to the study of atomic and molecular diffusion in biomaterials, polymers, semiconductors, liquid crystals, superionic conductors and the like. Such instruments have also been invaluable for ultra high resolution investigations of the low-lying quantum tunneling processes that provide direct insight into the dynamical response of solids at themore » lowest energies. Until relatively recently, however, all such instruments were located at steady-state reactors. This proposal describes HERMES I (High Energy Resolution Machines I) a CBS intended for installation at the LANSCE pulsed neutron facility of Los Alamos National Laboratory. As explained in detail in the main text, the authors propose to construct an updated, high-performance CBS which incorporates neutron techniques developed during the decade since IRIS was built, i.e., improved supermirror technology, a larger area crystal analyzer and high efficiency wire gas detectors. The instrument is designed in such a way as to be readily adaptable to future upgrades. HERMES I, they believe, will substantially expand the range and flexibility of neutron investigations in the United States and open new and potentially fruitful directions for condensed matter exploration. This document describes a implementation plan with a direct cost range between $4.5 to 5.6 M and scheduled duration of 39--45 months for identified alternatives.« less

High-Resolution Forest Carbon Monitoring and Modeling: Continued Prototype Development and Deployment Across The Tri-state Area (MD, PA, DE), USA

NASA Astrophysics Data System (ADS)

Hurtt, G. C.; Birdsey, R.; Campbell, E.; Dolan, K. A.; Dubayah, R.; Escobar, V. M.; Finley, A. O.; Flanagan, S.; Huang, W.; Johnson, K.; Lister, A.; ONeil-Dunne, J.; Sepulveda Carlo, E.; Zhao, M.

2017-12-01

Local, national and international programs have increasing need for precise and accurate estimates of forest carbon and structure to support greenhouse gas reduction plans, climate initiatives, and other international climate treaty frameworks. In 2010 Congress directed NASA to initiate research towards the development of Carbon Monitoring Systems (CMS). In response, our team has worked to develop a robust, replicable framework to produce maps of high-resolution carbon stocks and future carbon sequestration potential. High-resolution (30m) maps of carbon stocks and uncertainty were produced by linking national 1m-resolution imagery and existing wall-to-wall airborne lidar to spatially explicit in-situ field observations such as the USFS Forest Inventory and Analysis (FIA) network. These same data, characterizing forest extent and vertical structure, were used to drive a prognostic ecosystem model to predict carbon fluxes and carbon sequestration potential at unprecedented spatial resolution and scale (90m), more than 100,000 times the spatial resolution of standard global models. Through project development, the domain of this research has expanded from two counties in MD (2,181 km2), to the entire state (32,133 km2), to the tri-state region of MD, PA, and DE (157,868 km2), covering forests in four major USDA ecological providences (Eastern Broadleaf, Northeastern Mixed, Outer Coastal Plain, and Central Appalachian). Across the region, we estimate 694 Tg C (14 DE, 113 MD, 567 PA) in above ground biomass, and estimate a carbon sequestration potential more than twice that amount. Empirical biomass products enhance existing approaches though high resolution accounting for trees outside traditional forest maps. Modeling products move beyond traditional MRV, and map future afforestation and reforestation potential for carbon at local actionable spatial scales. These products are relevant to multiple stakeholder needs in the region as discussed through the Tri-sate Working Group, and are actively being used to inform the state of MD's Greenhouse Gas Reduction Act. The approach is scalable, and provides a protoype framework for application in other domains and for future spaceborne lidar missions.

MRI Superresolution Using Self-Similarity and Image Priors

PubMed Central

Manjón, José V.; Coupé, Pierrick; Buades, Antonio; Collins, D. Louis; Robles, Montserrat

2010-01-01

In Magnetic Resonance Imaging typical clinical settings, both low- and high-resolution images of different types are routinarily acquired. In some cases, the acquired low-resolution images have to be upsampled to match with other high-resolution images for posterior analysis or postprocessing such as registration or multimodal segmentation. However, classical interpolation techniques are not able to recover the high-frequency information lost during the acquisition process. In the present paper, a new superresolution method is proposed to reconstruct high-resolution images from the low-resolution ones using information from coplanar high resolution images acquired of the same subject. Furthermore, the reconstruction process is constrained to be physically plausible with the MR acquisition model that allows a meaningful interpretation of the results. Experiments on synthetic and real data are supplied to show the effectiveness of the proposed approach. A comparison with classical state-of-the-art interpolation techniques is presented to demonstrate the improved performance of the proposed methodology. PMID:21197094

HIGH-RESOLUTION FOURIER TRANSFORM INFRARED SPECTRUM OF THE ν2 + ν12 BAND OF ETHYLENE (12C2H4)

NASA Astrophysics Data System (ADS)

Lebron, G. B.; Tan, T. L.

2013-09-01

The high-resolution Fourier transform infrared absorption spectrum of the ν2 + ν12 combination band of normal ethylene (12C2H4) in the 3050-3105 cm-1 region was recorded at a resolution of 0.0063 cm-1 and at an ambient temperature of 296 K. Upper state rovibrational analysis was carried out using a standard Watson's Hamiltonian in asymmetric reduction in Ir representation. The band center, rotational constants and centrifugal distortion constants up to quartic terms of the upper ν2 + ν12 = 1 state were determined from the final fit that included 102 infrared transitions. The root-mean-square deviation of the fit was 0.000729 cm-1.

Detection of tannins in modern and fossil barks and in plant residues by high-resolution solid-state 13C nuclear magnetic resonance

USGS Publications Warehouse

Wilson, M.A.; Hatcher, P.G.

1988-01-01

Bark samples isolated from brown coal deposits in Victoria, Australia, and buried wood from Rhizophora mangle have been studies by high-resolution solid-state nuclear magnetic resonance (NMR) techniques. Dipolar dephasing 13C NMR appears to be a useful method of detecting the presence of tannins in geochemical samples including barks, buried woods, peats and leaf litter. It is shown that tannins are selectively preserved in bark during coalification to the brown coal stage. ?? 1988.

High Resolution UV Emission Spectroscopy of Molecules Excited by Electron Impact

NASA Technical Reports Server (NTRS)

James, G. K.; Ajello, J. M.; Beegle, L.; Ciocca, M.; Dziczek, D.; Kanik, I.; Noren, C.; Jonin, C.; Hansen, D.

1999-01-01

Photodissociation via discrete line absorption into predissociating Rydberg and valence states is the dominant destruction mechanism of CO and other molecules in the interstellar medium and molecular clouds. Accurate values for the rovibronic oscillator strengths of these transitions and predissociation yields of the excited states are required for input into the photochemical models that attempt to reproduce observed abundances. We report here on our latest experimental results of the electron collisional properties of CO and N2 obtained using the 3-meter high resolution single-scattering spectroscopic facility at JPL.

Xenia Mission: Spacecraft Design Concept

NASA Technical Reports Server (NTRS)

Hopkins, R. C.; Johnson, C. L.; Kouveliotou, C.; Jones, D.; Baysinger, M.; Bedsole, T.; Maples, C. C.; Benfield, P. J.; Turner, M.; Capizzo, P.;

High-resolution Monthly Satellite Precipitation Product over the Conterminous United States

NASA Astrophysics Data System (ADS)

Hashemi, H.; Fayne, J.; Knight, R. J.; Lakshmi, V.

2017-12-01

We present a data set that enhanced the Tropical Rainfall Measuring Mission (TRMM) Multi-satellite Precipitation Analysis (TMPA) monthly product 3B43 in its accuracy and spatial resolution. For this, we developed a correction function to improve the accuracy of TRMM 3B43, spatial resolution of 25 km, by estimating and removing the bias in the satellite data using a ground-based precipitation data set. We observed a strong relationship between the bias and land surface elevation; TRMM 3B43 tends to underestimate the ground-based product at elevations above 1500 m above mean sea level (m.amsl) over the conterminous United States. A relationship was developed between satellite bias and elevation. We then resampled TRMM 3B43 to the Digital Elevation Model (DEM) data set at a spatial resolution of 30 arc second ( 1 km on the ground). The produced high-resolution satellite-based data set was corrected using the developed correction function based on the bias-elevation relationship. Assuming that each rain gauge represents an area of 1 km2, we verified our product against 9,200 rain gauges across the conterminous United States. The new product was compared with the gauges, which have 50, 60, 70, 80, 90, and 100% temporal coverage within the TRMM period of 1998 to 2015. Comparisons between the high-resolution corrected satellite-based data and gauges showed an excellent agreement. The new product captured more detail in the changes in precipitation over the mountainous region than the original TRMM 3B43.

Implications of uncertainty on regional CO2 mitigation policies for the U.S. onroad sector based on a high-resolution emissions estimate

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mendoza, D.; Gurney, Kevin R.; Geethakumar, Sarath

2013-04-01

In this study we present onroad fossil fuel CO2 emissions estimated by the Vulcan Project, an effort quantifying fossil fuel CO2 emissions for the U.S. in high spatial and temporal resolution. This high-resolution data, aggregated at the state-level and classified in broad road and vehicle type categories, is compared to a commonly used national-average approach. We find that the use of national averages incurs state-level biases for road groupings that are almost twice as large as for vehicle groupings. The uncertainty for all groups exceeds the bias, and both quantities are positively correlated with total state emissions. States with themore » largest emissions totals are typically similar to one another in terms of emissions fraction distribution across road and vehicle groups, while smaller-emitting states have a wider range of variation in all groups. Errors in reduction estimates as large as ±60% corresponding to ±0.2 MtC are found for a national-average emissions mitigation strategy focused on a 10% emissions reduction from a single vehicle class, such as passenger gas vehicles or heavy diesel trucks. Recommendations are made for reducing CO2 emissions uncertainty by addressing its main drivers: VMT and fuel efficiency uncertainty.« less

Enhancing SMAP Soil Moisture Retrievals via Superresolution Techniques

NASA Astrophysics Data System (ADS)

Beale, K. D.; Ebtehaj, A. M.; Romberg, J. K.; Bras, R. L.

2017-12-01

Soil moisture is a key state variable that modulates land-atmosphere interactions and its high-resolution global scale estimates are essential for improved weather forecasting, drought prediction, crop management, and the safety of troop mobility. Currently, NASA's Soil Moisture Active/Passive (SMAP) satellite provides a global picture of soil moisture variability at a resolution of 36 km, which is prohibitive for some hydrologic applications. The goal of this research is to enhance the resolution of SMAP passive microwave retrievals by a factor of 2 to 4 using modern superresolution techniques that rely on the knowledge of high-resolution land surface models. In this work, we explore several super-resolution techniques including an empirical dictionary method, a learned dictionary method, and a three-layer convolutional neural network. Using a year of global high-resolution land surface model simulations as training set, we found that we are able to produce high-resolution soil moisture maps that outperform the original low-resolution observations both qualitatively and quantitatively. In particular, on a patch-by-patch basis we are able to produce estimates of high-resolution soil moisture maps that improve on the original low-resolution patches by on average 6% in terms of mean-squared error, and 14% in terms of the structural similarity index.

Interactive Display of High-Resolution Images on the World Wide Web.

ERIC Educational Resources Information Center

Clyde, Stephen W.; Hirschi, Gregory W.

Viewing high-resolution images on the World Wide Web at a level of detail necessary for collaborative research is still a problem today, given the Internet's current bandwidth limitations and its ever increasing network traffic. ImageEyes is an interactive display tool being developed at Utah State University that addresses this problem by…

ERIC First Analysis: The United States Justice System; 1983-84 National High School Debate Resolutions.

ERIC Educational Resources Information Center

Wagner, David L.

Designed to serve as a framework from which high school debate students, coaches, and judges can evaluate the issues, arguments, and evidence present in sustaining and reforming the U.S. justice system, this booklet provides debaters with guidelines for research on the 1983-84 debate resolutions selected by the National University Continuing…

ERIC First Analysis: Water Resources; 1985-86 National High School Debate Resolutions.

ERIC Educational Resources Information Center

Wagner, David L.; Fraleigh, Douglas

Designed to serve as a framework from which high school debate students, coaches, and judges can evaluate the issues, arguments and evidence present in the availability and quality of water resources in the United States, this booklet provides guidelines for research on the 1985-86 debate resolutions selected by the National Federation of State…

High-resolution study of Gamow-Teller transitions in the 47Ti(3He,t)47V reaction

NASA Astrophysics Data System (ADS)

Ganioǧlu, E.; Fujita, H.; Fujita, Y.; Adachi, T.; Algora, A.; Csatlós, M.; Deaven, J. M.; Estevez-Aguado, E.; Guess, C. J.; Gulyás, J.; Hatanaka, K.; Hirota, K.; Honma, M.; Ishikawa, D.; Krasznahorkay, A.; Matsubara, H.; Meharchand, R.; Molina, F.; Okamura, H.; Ong, H. J.; Otsuka, T.; Perdikakis, G.; Rubio, B.; Scholl, C.; Shimbara, Y.; Susoy, G.; Suzuki, T.; Tamii, A.; Thies, J. H.; Zegers, R. G. T.; Zenihiro, J.

2013-01-01

Given the importance of Gamow-Teller (GT) transitions in nuclear structure and astrophysical nuclear processes, we have studied Tz=+3/2→+1/2, GT transitions starting from the 47Ti nucleus in the (3He,t) charge-exchange reaction at 0∘ and at an intermediate incident energy of 140 MeV/nucleon. The experiments were carried out at the Research Center for Nuclear Physics (RCNP), Osaka, using the high-resolution facility with a high-dispersion beam line and the Grand-Raiden spectrometer. With an energy resolution of 20 keV, individual GT transitions were observed and GT strength was derived for each state populated up to an excitation energy (Ex) of 12.5 MeV. The GT strength was widely distributed from low excitation energy up to 12.5 MeV, where we had to stop the analysis because of the high level density. The distribution of the GT strengths was compared with the results of shell model calculations using the GXPF1 interaction. The calculations could reproduce the experimental GT distributions well. The GT transitions from the ground state of 47Ti and the M1 transitions from the isobaric analog state in 47V to the same low-lying states in 47V are analogous. It was found that the ratios of GT transition strengths to the ground state, the 0.088-MeV state, and the 0.146-MeV state are similar to the ratios of the strengths of the analogous M1 transitions from the isobaric analog state (IAS) to these states. The measured distribution of the GT strengths was also compared with those starting from the Tz=+3/2 nucleus 41K to the Tz=+1/2 nucleus 41Ca.

High-Resolution Audio with Inaudible High-Frequency Components Induces a Relaxed Attentional State without Conscious Awareness.

PubMed

Kuribayashi, Ryuma; Nittono, Hiroshi

2017-01-01

High-resolution audio has a higher sampling frequency and a greater bit depth than conventional low-resolution audio such as compact disks. The higher sampling frequency enables inaudible sound components (above 20 kHz) that are cut off in low-resolution audio to be reproduced. Previous studies of high-resolution audio have mainly focused on the effect of such high-frequency components. It is known that alpha-band power in a human electroencephalogram (EEG) is larger when the inaudible high-frequency components are present than when they are absent. Traditionally, alpha-band EEG activity has been associated with arousal level. However, no previous studies have explored whether sound sources with high-frequency components affect the arousal level of listeners. The present study examined this possibility by having 22 participants listen to two types of a 400-s musical excerpt of French Suite No. 5 by J. S. Bach (on cembalo, 24-bit quantization, 192 kHz A/D sampling), with or without inaudible high-frequency components, while performing a visual vigilance task. High-alpha (10.5-13 Hz) and low-beta (13-20 Hz) EEG powers were larger for the excerpt with high-frequency components than for the excerpt without them. Reaction times and error rates did not change during the task and were not different between the excerpts. The amplitude of the P3 component elicited by target stimuli in the vigilance task increased in the second half of the listening period for the excerpt with high-frequency components, whereas no such P3 amplitude change was observed for the other excerpt without them. The participants did not distinguish between these excerpts in terms of sound quality. Only a subjective rating of inactive pleasantness after listening was higher for the excerpt with high-frequency components than for the other excerpt. The present study shows that high-resolution audio that retains high-frequency components has an advantage over similar and indistinguishable digital sound sources in which such components are artificially cut off, suggesting that high-resolution audio with inaudible high-frequency components induces a relaxed attentional state without conscious awareness.

Development and Evaluation of High-Resolution Climate Simulations Over the Mountainous Northeastern United States

NASA Technical Reports Server (NTRS)

Winter, Jonathan M.; Beckage, Brian; Bucini, Gabriela; Horton, Radley M.; Clemins, Patrick J.

2016-01-01

The mountain regions of the northeastern United States are a critical socioeconomic resource for Vermont, New York State, New Hampshire, Maine, and southern Quebec. While global climate models (GCMs) are important tools for climate change risk assessment at regional scales, even the increased spatial resolution of statistically downscaled GCMs (commonly approximately 1/ 8 deg) is not sufficient for hydrologic, ecologic, and land-use modeling of small watersheds within the mountainous Northeast. To address this limitation, an ensemble of topographically downscaled, high-resolution (30"), daily 2-m maximum air temperature; 2-m minimum air temperature; and precipitation simulations are developed for the mountainous Northeast by applying an additional level of downscaling to intermediately downscaled (1/ 8 deg) data using high-resolution topography and station observations. First, observed relationships between 2-m air temperature and elevation and between precipitation and elevation are derived. Then, these relationships are combined with spatial interpolation to enhance the resolution of intermediately downscaled GCM simulations. The resulting topographically downscaled dataset is analyzed for its ability to reproduce station observations. Topographic downscaling adds value to intermediately downscaled maximum and minimum 2-m air temperature at high-elevation stations, as well as moderately improves domain-averaged maximum and minimum 2-m air temperature. Topographic downscaling also improves mean precipitation but not daily probability distributions of precipitation. Overall, the utility of topographic downscaling is dependent on the initial bias of the intermediately downscaled product and the magnitude of the elevation adjustment. As the initial bias or elevation adjustment increases, more value is added to the topographically downscaled product.

Unusual inhomogeneous microstructures in charge glass state of PbCrO3

NASA Astrophysics Data System (ADS)

Kurushima, Kosuke; Tsukasaki, Hirofumi; Ogata, Takahiro; Sakai, Yuki; Azuma, Masaki; Ishii, Yui; Mori, Shigeo

2018-05-01

We investigated the microstructures and local structures of perovskite PbCrO3, which shows a metal-to-insulator transition and a 9.8% volume collapse, by electron diffraction, high-resolution transmission electron microscopy (TEM), and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). It is revealed that the charge glass state is characterized by the unique coexistence of the crystalline state with a cubic symmetry on average and the noncrystalline state. HAADF-STEM observation at atomic resolution revealed that Pb ions were displaced from the ideal A site position of the cubic perovskite structure, which gives rise to characteristic diffuse scatterings around the fundamental Bragg reflections. These structural inhomogeneities are crucial to the understanding of the unique physical properties in the charge glass state of PbCrO3.

Electron microscopy localization and characterization of functionalized composite organic-inorganic SERS nanoparticles on leukemia cells.

PubMed

Koh, Ai Leen; Shachaf, Catherine M; Elchuri, Sailaja; Nolan, Garry P; Sinclair, Robert

2008-12-01

We demonstrate the use of electron microscopy as a powerful characterization tool to identify and locate antibody-conjugated composite organic-inorganic nanoparticle (COINs) surface enhanced Raman scattering (SERS) nanoparticles on cells. U937 leukemia cells labeled with antibody CD54-conjugated COINs were characterized in their native, hydrated state using wet scanning electron microscopy (SEM) and in their dehydrated state using high-resolution SEM. In both cases, the backscattered electron (BSE) detector was used to detect and identify the silver constituents in COINs due to its high sensitivity to atomic number variations within a specimen. The imaging and analytical capabilities in the SEM were further complemented by higher resolution transmission electron microscopy (TEM) images and scanning Auger electron spectroscopy (AES) data to give reliable and high-resolution information about nanoparticles and their binding to cell surface antigens.

Electron Microscopy Localization and Characterization of Functionalized Composite Organic-Inorganic SERS Nanoparticles on Leukemia Cells

PubMed Central

Koh, Ai Leen; Shachaf, Catherine M.; Elchuri, Sailaja; Nolan, Garry P.; Sinclair, Robert

2008-01-01

We demonstrate the use of electron microscopy as a powerful characterization tool to identify and locate antibody-conjugated composite organic-inorganic (COINs) surface enhanced Raman scattering (SERS) nanoparticles on cells. U937 leukemia cells labeled with antibody CD54-conjugated COINs were characterized in their native, hydrated state using wet Scanning Electron Microscopy (SEM) and in their dehydrated state using high-resolution SEM. In both cases, the backscattered electron detector (BSE) was used to detect and identify the silver constituents in COINs due to its high sensitivity to atomic number variations within a specimen. The imaging and analytical capabilities in the SEM were further complemented by higher resolution Transmission Electron Microscope (TEM) images and Scanning Auger Electron Spectroscopy (AES) data to give reliable and high-resolution information about nanoparticles and their binding to cell surface antigens. PMID:18995965

ERIC First Analysis: 1980-81 National High School Debate Resolutions (How Can the Interests of United States Consumers Best Be Served?).

ERIC Educational Resources Information Center

Wagner, David L.

The five chapters of this book are intended to prepare high school debaters and their coaches for the efficient investigation of the 1980-81 High Scbool Debate Problem Area and Resolutions. The first chapter contains an overview of the problem area--consumer interests--describing the basic concepts of regulation and risk, the definitions of the…

Mesosacle eddies in a high resolution OGCM and coupled ocean-atmosphere GCM

NASA Astrophysics Data System (ADS)

Yu, Y.; Liu, H.; Lin, P.

2017-12-01

The present study described high-resolution climate modeling efforts including oceanic, atmospheric and coupled general circulation model (GCM) at the state key laboratory of numerical modeling for atmospheric sciences and geophysical fluid dynamics (LASG), Institute of Atmospheric Physics (IAP). The high-resolution OGCM is established based on the latest version of the LASG/IAP Climate system Ocean Model (LICOM2.1), but its horizontal resolution and vertical resolution are increased to 1/10° and 55 layers, respectively. Forced by the surface fluxes from the reanalysis and observed data, the model has been integrated for approximately more than 80 model years. Compared with the simulation of the coarse-resolution OGCM, the eddy-resolving OGCM not only better simulates the spatial-temporal features of mesoscale eddies and the paths and positions of western boundary currents but also reproduces the large meander of the Kuroshio Current and its interannual variability. Another aspect, namely, the complex structures of equatorial Pacific currents and currents in the coastal ocean of China, are better captured due to the increased horizontal and vertical resolution. Then we coupled the high resolution OGCM to NCAR CAM4 with 25km resolution, in which the mesoscale air-sea interaction processes are better captured.

"No! The lambs can stay out because they got cozies": constructive and destructive sibling conflict, pretend play, and social understanding.

PubMed

Howe, Nina; Rinaldi, Christina M; Jennings, Melissa; Petrakos, Harriet

2002-01-01

Associations among constructive and destructive sibling conflict, pretend play, internal state language, and sibling relationship quality were investigated in 40 middle-class dyads with a kindergarten-age child (M age = 5.7 years). In 20 dyads the sibling was older (M age = 7.1 years) and in 20 dyads the sibling was younger (M age = 3.6 years). Dyads were videotaped playing with a farm set for 15 min; transcribed sessions were coded for (1) five types of conflict issues; (2) constructive, destructive, and passive resolution strategies; and (3) verbal and physical aggression. Measures of pretend play enactment, low- and high-level pretense negotiation strategies, and internal state language were also based on the transcripts. The Sibling Behavior and Feelings Questionnaire was used to assess both siblings' perceptions of sibling relationship quality. Findings revealed that conflict issues, aggression, and internal state language were associated with specific resolution strategies. Associations were evident between conflict issues and resolutions. Moreover, conflict issues and resolutions were associated with (1) relationship quality, (2) high-level pretense negotiation, and (3) internal state language employed in both play and conflict. Findings are discussed in light of recent theory on developmental processes operating within children's relationships.

Applied Geospatial Education: Acquisition and Processing of High Resolution Airborne LIDAR and Orthoimages for the Great Smoky Mountains National Park, Southeastern United States

NASA Astrophysics Data System (ADS)

Jordan, T. R.; Madden, M.; Sharma, J. B.; Panda, S. S.

2012-07-01

In an innovative collaboration between government, university and private industry, researchers at the University of Georgia and Gainesville State College are collaborating with Photo Science, Inc. to acquire, process and quality control check lidar and or-thoimages of forest areas in the Southern Appalachian Mountains of the United States. Funded by the U.S. Geological Survey, this project meets the objectives of the ARRA initiative by creating jobs, preserving jobs and training students for high skill positions in geospatial technology. Leaf-off lidar data were acquired at 1-m resolution of the Tennessee portion of the Great Smoky Mountain National Park (GRSM) and adjacent Foothills Parkway. This 1400-sq. km. area is of high priority for national/global interests due to biodiversity, rare and endangered species and protection of some of the last remaining virgin forest in the U.S. High spatial resolution (30 cm) leaf-off 4-band multispectral orthoimages also were acquired for both the Chattahoochee National Forest in north Georgia and the entire GRSM. The data are intended to augment the National Elevation Dataset and orthoimage database of The National Map with information that can be used by many researchers in applications of LiDAR point clouds, high resolution DEMs and or-thoimage mosaics. Graduate and undergraduate students were involved at every stage of the workflow in order to provide then with high level technical educational and professional experience in preparation for entering the geospatial workforce. This paper will present geospatial workflow strategies, multi-team coordination, distance-learning training and industry-academia partnership.

Differential absorption lidars for remote sensing of atmospheric pressure and temperature profiles

NASA Technical Reports Server (NTRS)

Korb, C. Laurence; Schwemmer, Geary K.; Famiglietti, Joseph; Walden, Harvey; Prasad, Coorg

1995-01-01

A near infrared differential absorption lidar technique is developed using atmospheric oxygen as a tracer for high resolution vertical profiles of pressure and temperature with high accuracy. Solid-state tunable lasers and high-resolution spectrum analyzers are developed to carry out ground-based and airborne measurement demonstrations and results of the measurements presented. Numerical error analysis of high-altitude airborne and spaceborne experiments is carried out, and system concepts developed for their implementation.

Landscape correlates of forest plant invasions: A high-resolution analysis across the eastern United States

Treesearch

Kurt Riitters; Kevin Potter; Basil V. Iannone; Christopher Oswalt; Songlin Fei; Qinfeng Guo

2017-01-01

Aim: Invasive species occurrence is often related to the anthropogenic context of a given area. Quantifying the effects of roads is of particular interest as roads are a major vector for invasion. Our objective was to further quantify the effects of roads on forest plant invasion through a macroscale, high-resolution investigation to assist...

ERIC First Analysis: National Defense Commitments; 1982-83 National High School Debate Resolutions.

ERIC Educational Resources Information Center

Wagner, David L.

The purpose of this booklet is to provide a brief overview of some of the issues involved in the 1982-83 high school debate resolutions, which focus on the defense commitments of the United States. The first of the booklet's four chapters provides a review of information sources for use in researching the topic of defense commitments. The…

Using fire regimes to delineate zones in a high-resolution lake sediment record from the western United States

Treesearch

Jesse L. Morris; Andrea Brunelle; R. Justin DeRose; Heikki Seppa; Mitchell J. Power; Vachel Carter; Ryan Bares

2013-01-01

Paleoenvironmental reconstructions are important for understanding the influence of long-term climate variability on ecosystems and landscape disturbance dynamics. In this paper we explore the linkages among past climate, vegetation, and fire regimes using a high-resolution pollen and charcoal reconstruction from Morris Pond located on the Markagunt Plateau in...

High-resolution threshold photoionization of N2O

NASA Technical Reports Server (NTRS)

Wiedmann, R. T.; Grant, E. R.; Tonkyn, R. G.; White, M. G.

1991-01-01

Pulsed field ionization (PFI) has been used in conjunction with a coherent VUV source to obtain high-resolution threshold photoelectron spectra for the (000), (010), (020), and (100) vibrational states of the N2O(+) cation. Simulations for the rotational profiles of each vibronic level were obtained by fitting the Buckingham-Orr-Sichel equations using accurate spectroscopic constants for the ground states of the neutral and the ion. The relative branch intensities are interpreted in terms of the partial waves of the outgoing photoelectron to which the ionic core is coupled and in terms of the angular momentum transferred to the core.

High-resolution absorption measurements of NH3 at high temperatures: 500-2100 cm-1

NASA Astrophysics Data System (ADS)

Barton, Emma J.; Yurchenko, Sergei N.; Tennyson, Jonathan; Clausen, Sønnik; Fateev, Alexander

2015-12-01

High-resolution absorption spectra of NH3 in the region 500-2100 cm-1 at temperatures up to 1027 °C and approximately atmospheric pressure (1013±20 mbar) are measured. NH3 concentrations of 1000 ppm, 0.5% and 1% in volume fraction were used in the measurements. Spectra are recorded in high temperature gas flow cells using a Fourier Transform Infrared (FTIR) spectrometer at a nominal resolution of 0.09 cm-1. Measurements at 22.7 °C are compared to high-resolution cross sections available from the Pacific Northwest National Laboratory (PNNL). The higher temperature spectra are analysed by comparison to a variational line list, BYTe, and experimental energy levels determined using the MARVEL procedure. Approximately 2000 lines have been assigned, of which 851 are newly assigned to mainly hot bands involving vibrational states as high as v2=5.

Solid state high resolution multi-spectral imager CCD test phase

NASA Technical Reports Server (NTRS)

1973-01-01

The program consisted of measuring the performance characteristics of charge coupled linear imaging devices, and a study defining a multispectral imaging system employing advanced solid state photodetection techniques.

High Resolution Far Infrared Spectroscopy of HFC-134a at Cold Temperatures

NASA Astrophysics Data System (ADS)

Wong, Andy; Medcraft, Chris; Thompson, Christopher; Robertson, Evan Gary; Appadoo, Dominique; McNaughton, Don

2016-06-01

Since the signing of the Montreal protocol, long-lived chlorofluorocarbons have been banned due to their high ozone depleting potential. In order to minimise the effect of such molecules, hydrofluorocarbons (HFCs) were synthesized as replacement molecules to be used as refrigerants and foam blowing agents. HFC-134a, or 1,1,1,2-tetrafluoroethane, is one of these molecules. Although HFCs do not cause ozone depletion, they are typically strong absorbers within the 10 micron atmospheric window, which lead to high global warming potentials. A high resolution FT-IR analysis of the νb{8} band (near 665 wn) of HFC-134a has been performed to help understand the intermode coupling between the νb{8} vibrational state and unobserved dark states.

Single image super-resolution reconstruction algorithm based on eage selection

NASA Astrophysics Data System (ADS)

Zhang, Yaolan; Liu, Yijun

2017-05-01

Super-resolution (SR) has become more important, because it can generate high-quality high-resolution (HR) images from low-resolution (LR) input images. At present, there are a lot of work is concentrated on developing sophisticated image priors to improve the image quality, while taking much less attention to estimating and incorporating the blur model that can also impact the reconstruction results. We present a new reconstruction method based on eager selection. This method takes full account of the factors that affect the blur kernel estimation and accurately estimating the blur process. When comparing with the state-of-the-art methods, our method has comparable performance.

High-Resolution Land Use and Land Cover Mapping

USGS Publications Warehouse

,

1999-01-01

As the Nation?s population grows, quantifying, monitoring, and managing land use becomes increasingly important. The U.S. Geological Survey (USGS) has a long heritage of leadership and innovation in land use and land cover (LULC) mapping that has been the model both nationally and internationally for over 20 years. At present, the USGS is producing high-resolution LULC data for several watershed and urban areas within the United States. This high-resolution LULC mapping is part of an ongoing USGS Land Cover Characterization Program (LCCP). The four components of the LCCP are global (1:2,000,000-scale), national (1:100,000-scale), urban (1:24,000-scale), and special projects (various scales and time periods). Within the urban and special project components, the USGS Rocky Mountain Mapping Center (RMMC) is collecting historical as well as contemporary high-resolution LULC data. RMMC?s high-resolution LULC mapping builds on the heritage and success of previous USGS LULC programs and provides LULC information to meet user requirements.

Experimental sub-Rayleigh resolution by an unseeded high-gain optical parametric amplifier for quantum lithography

NASA Astrophysics Data System (ADS)

Sciarrino, Fabio; Vitelli, Chiara; de Martini, Francesco; Glasser, Ryan; Cable, Hugo; Dowling, Jonathan P.

2008-01-01

Quantum lithography proposes to adopt entangled quantum states in order to increase resolution in interferometry. In the present paper we experimentally demonstrate that the output of a high-gain optical parametric amplifier can be intense yet exhibits quantum features, namely, sub-Rayleigh fringes, as proposed by [Agarwal , Phys. Rev. Lett. 86, 1389 (2001)]. We investigate multiphoton states generated by a high-gain optical parametric amplifier operating with a quantum vacuum input for gain values up to 2.5. The visibility has then been increased by means of three-photon absorption. The present paper opens interesting perspectives for the implementation of such an advanced interferometrical setup.

NHDPlusHR: A national geospatial framework for surface-water information

USGS Publications Warehouse

Viger, Roland; Rea, Alan H.; Simley, Jeffrey D.; Hanson, Karen M.

2016-01-01

The U.S. Geological Survey is developing a new geospatial hydrographic framework for the United States, called the National Hydrography Dataset Plus High Resolution (NHDPlusHR), that integrates a diversity of the best-available information, robustly supports ongoing dataset improvements, enables hydrographic generalization to derive alternate representations of the network while maintaining feature identity, and supports modern scientific computing and Internet accessibility needs. This framework is based on the High Resolution National Hydrography Dataset, the Watershed Boundaries Dataset, and elevation from the 3-D Elevation Program, and will provide an authoritative, high precision, and attribute-rich geospatial framework for surface-water information for the United States. Using this common geospatial framework will provide a consistent basis for indexing water information in the United States, eliminate redundancy, and harmonize access to, and exchange of water information.

γ-ray telescopes using conversions to e+e- pairs: event generators, angular resolution and polarimetry

NASA Astrophysics Data System (ADS)

Gros, P.; Bernard, D.

2017-02-01

We benchmark various available event generators in Geant4 and EGS5 in the light of ongoing projects for high angular-resolution pair-conversion telescopes at low energy. We compare the distributions of key kinematic variables extracted from the geometry of the three final state particles. We validate and use as reference an exact generator using the full 5D differential cross-section of the conversion process. We focus in particular on the effect of the unmeasured recoiling nucleus on the angular resolution. We show that for high resolution trackers, the choice of the generator affects the estimated resolution of the telescope. We also show that the current available generator are unable to describe accurately a linearly polarised photon source.

The determination of potential energy curve and dipole moment of the (5)0{sup +} electronic state of {sup 85}Rb{sup 133}Cs molecule by high resolution photoassociation spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Jinpeng; Zhao, Yanting, E-mail: zhaoyt@sxu.edu.cn; Ji, Zhonghua

2015-12-14

We present the formation of ultracold {sup 85}Rb{sup 133}Cs molecules in the (5)0{sup +} electronic state by photoassociation and their detection via resonance-enhanced two-photon ionization. Up to v = 47 vibrational levels including the lowest v = 0 vibrational and lowest J = 0 levels are identified with rotationally resolved high resolution photoassociation spectra. Precise Dunham coefficients are determined for the (5)0{sup +} state with high accuracy, then the Rydberg-Klein-Rees potential energy curve is derived. The electric dipole moments with respect to the vibrational numbers of the (5)0{sup +} electronic state of {sup 85}Rb{sup 133}Cs molecule are also measured inmore » the range between 1.9 and 4.8 D. These comprehensive studies on previously unobserved rovibrational levels of the (5)0{sup +} state are helpful to understand the molecular structure and discover suitable transition pathways for transferring ultracold atoms to deeply bound rovibrational levels of the electronic ground state.« less

Seismic Tomography and the Development of a State Velocity Profile

NASA Astrophysics Data System (ADS)

Marsh, S. J.; Nakata, N.

2017-12-01

Earthquakes have been a growing concern in the State of Oklahoma in the last few years and as a result, accurate earthquake location is of utmost importance. This means using a high resolution velocity model with both lateral and vertical variations. Velocity data is determined using ambient noise seismic interferometry and tomography. Passive seismic data was acquired from multiple IRIS networks over the span of eight years (2009-2016) and filtered for earthquake removal to obtain the background ambient noise profile for the state. Seismic Interferometry is applied to simulate ray paths between stations, this is done with each possible station pair for highest resolution. Finally the method of seismic tomography is used to extract the velocity data and develop the state velocity map. The final velocity profile will be a compilation of different network analyses due to changing station availability from year to year. North-Central Oklahoma has a dense seismic network and has been operating for the past few years. The seismic stations are located here because this is the most seismically active region. Other parts of the state have not had consistent coverage from year to year, and as such a reliable and high resolution velocity profile cannot be determined from this network. However, the Transportable Array (TA) passed through Oklahoma in 2014 and provided a much wider and evenly spaced coverage. The goal of this study is to ultimately combine these two arrays over time, and provide a high quality velocity profile for the State of Oklahoma.

Evaluation of real-time high-resolution MM5 predictions over the Great Lakes region

Treesearch

Shiyuan Zhong; Hee-Jin In; Xindi Bian; Joseph Charney; Warren Heilman; Brian Potter

2005-01-01

Real-time high-resolution mesoscale predictions using the fifth-generation Pennsylvania State University–NCAR Mesoscale Model (MM5) over the Great Lakes region are evaluated for the 2002/03 winter and 2003 summer seasons using surface and upper-air observations, with a focus on near-surface and boundary layer properties that are important for applications such as air...

The AstroSat Production Line: From AstroSat 100 to AstroSat 1000

NASA Astrophysics Data System (ADS)

Maliet, E.; Pawlak, D.; Koeck, C.; Beaufumé, E.

2008-08-01

From the late 90s onward, Astrium Satellites has developed and improved several classes of high resolution optical Earth Observation satellites. The resulting product line ranges from micro-satellites (about 120 kg) type to the large satellites (in the range of 1 200 kg). They all make uses of state of the art technologies for optical payloads, as well as for avionics. Several classes of platforms have thus been defined and standardised: AstroSat 100 for satellites up to 150 kg, allowing affordable but fully operational missions, AstroSat 500 for satellites up to 800 kg, allowing complex high resolution missions, and AstroSat 1000 for satellites up to 1 200 kg, providing very high resolution and outstanding imaging and agility capabilities. A new class, AstroSat 250, has been developed by Astrium Satellites, and is now proposed, offering a state-of-the-art 3-axis agile platform for high- resolution missions, with a launch mass below 550 kg. The Astrosat platforms rely on a centralised architecture avionics based on an innovative AOCS hybridising of measurements from GPS, stellar sensors and inertial reference unit. Operational safety has been emphasised through thruster free safe modes. All optical payloads make use of all Silicon Carbide (SiC) telescopes. High performance and low consumption linear CCD arrays provide state of the art images. The satellites are designed for simple flight operations, large data collection capability, and large versatility of payload and missions. They are adaptable to a large range of performances. Astrium satellites have already been selected by various customers worldwide.

High-resolution electronic spectra of yttrium oxide (YO): The D2Σ+-X2Σ+ transition.

PubMed

Zhang, Deping; Zhang, Qiang; Zhu, Boxing; Gu, Jingwang; Suo, Bingbing; Chen, Yang; Zhao, Dongfeng

2017-03-21

The D 2 Σ + -X 2 Σ + electronic absorption spectrum of the astrophysically relevant yttrium oxide (YO) molecule has been recorded for the first time in the 400-440 nm region using laser induced fluorescence. YO molecules are produced by corona discharge of oxygen between the tips of two yttrium needles in a supersonic jet expansion. An unambiguous spectroscopic identification of the D 2 Σ + -X 2 Σ + transition becomes possible from a combined analysis of the moderate-resolution laser excitation spectrum and dispersed fluorescence spectrum. We have also performed multi-state complete active space second order perturbation theory calculations on the first six doublets of YO, and the results support our assignment of the D 2 Σ + state. Accurate spectroscopic constants for D 2 Σ + ν' = 0 and 1 levels have been determined from a rotational analysis of the high resolution spectra that are recorded with a resolution of ∼0.018 cm -1 . Severe perturbations are observed in the experimental spectra and are considered to originate from interactions with at least one nearby 2/4 Π electronic state, e.g., the undetected C 2 Π state. We have also measured the radiative lifetimes of B 2 Σ + ν' = 0, and D 2 Σ + ν' = 0 and 1 states, based on which the B 2 Σ + -X 2 Σ + (0, 0) and D 2 Σ + -X 2 Σ + (0/1, 0) band oscillator strengths have been determined.

High-resolution electronic spectra of yttrium oxide (YO): The D2Σ+-X2Σ+ transition

NASA Astrophysics Data System (ADS)

Zhang, Deping; Zhang, Qiang; Zhu, Boxing; Gu, Jingwang; Suo, Bingbing; Chen, Yang; Zhao, Dongfeng

2017-03-01

The D2Σ+ -X2Σ+ electronic absorption spectrum of the astrophysically relevant yttrium oxide (YO) molecule has been recorded for the first time in the 400-440 nm region using laser induced fluorescence. YO molecules are produced by corona discharge of oxygen between the tips of two yttrium needles in a supersonic jet expansion. An unambiguous spectroscopic identification of the D2Σ+ -X2Σ+ transition becomes possible from a combined analysis of the moderate-resolution laser excitation spectrum and dispersed fluorescence spectrum. We have also performed multi-state complete active space second order perturbation theory calculations on the first six doublets of YO, and the results support our assignment of the D2Σ+ state. Accurate spectroscopic constants for D2Σ+ ν ' = 0 and 1 levels have been determined from a rotational analysis of the high resolution spectra that are recorded with a resolution of ˜0.018 cm-1. Severe perturbations are observed in the experimental spectra and are considered to originate from interactions with at least one nearby 2/4Π electronic state, e.g., the undetected C2Π state. We have also measured the radiative lifetimes of B2 Σ+ ν ' = 0, and D2 Σ+ ν ' = 0 and 1 states, based on which the B2Σ+ -X2Σ+ (0, 0) and D2Σ+ -X2Σ+ (0/1, 0) band oscillator strengths have been determined.

SWICS/Ulysses and MASS/wind observations of solar wind sulfur charge states

NASA Technical Reports Server (NTRS)

Cohen, C. M. S.; Galvin, A. B.; Hamilton, D. C.; Gloeckler, G.; Geiss, J.; Bochsler, P.

1995-01-01

As Ulysses journeys from the southern to the northern solar pole, the newly launched Wind spacecraft is monitoring the solar wind near 1 AU, slightly upstream of the Earth. Different solar wind structures pass over both spacecraft as coronal holes and other features rotate in and out of view. Ulysses and Wind are presently on opposing sides of the sun allowing us to monitor these streams for extended periods of time. Composition measurements made by instruments on both spacecraft provide information concerning the evolution and properties of these structures. We have combined data from the Solar Wind Ion Composition Spectrometer (SWICS) on Ulysses and the high mass resolution spectrometer (MASS) on Wind to determine the charge state distribution of sulfur in the solar wind. Both instruments employ electrostatic deflection with time-of-flight measurement. The high mass resolution of the MASS instrument (M/Delta-M approximately 100) allows sulfur to be isolated easily while the stepping energy/charge selection provides charge state information. SWICS measurements allow the unique identification of heavy ions by their mass and mass/charge with resolutions of M/Delta-M approximately 3 and M/q/Delta(M/q) approximately 20. The two instruments complement each other nicely in that MASS has the greater mass resolution while SWICS has the better mass/charge resolution and better statistics.

Development of High-Resolution Dynamic Dust Source Function - A Case Study with a Strong Dust Storm in a Regional Model

NASA Technical Reports Server (NTRS)

Kim, Dongchul; Chin, Mian; Kemp, Eric M.; Tao, Zhining; Peters-Lidard, Christa D.; Ginoux, Paul

2017-01-01

A high-resolution dynamic dust source has been developed in the NASA Unified-Weather Research and Forecasting (NU-WRF) model to improve the existing coarse static dust source. In the new dust source map, topographic depression is in 1-km resolution and surface bareness is derived using the Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectroradiometer (MODIS). The new dust source better resolves the complex topographic distribution over the Western United States where its magnitude is higher than the existing, coarser resolution static source. A case study is conducted with an extreme dust storm that occurred in Phoenix, Arizona in 0203 UTC July 6, 2011. The NU-WRF model with the new high-resolution dynamic dust source is able to successfully capture the dust storm, which was not achieved with the old source identification. However the case study also reveals several challenges in reproducing the time evolution of the short-lived, extreme dust storm events.

Development of High-Resolution Dynamic Dust Source Function -A Case Study with a Strong Dust Storm in a Regional Model

PubMed Central

Kim, Dongchul; Chin, Mian; Kemp, Eric M.; Tao, Zhining; Peters-Lidard, Christa D.; Ginoux, Paul

2018-01-01

A high-resolution dynamic dust source has been developed in the NASA Unified-Weather Research and Forecasting (NU-WRF) model to improve the existing coarse static dust source. In the new dust source map, topographic depression is in 1-km resolution and surface bareness is derived using the Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectroradiometer (MODIS). The new dust source better resolves the complex topographic distribution over the Western United States where its magnitude is higher than the existing, coarser resolution static source. A case study is conducted with an extreme dust storm that occurred in Phoenix, Arizona in 02-03 UTC July 6, 2011. The NU-WRF model with the new high-resolution dynamic dust source is able to successfully capture the dust storm, which was not achieved with the old source identification. However the case study also reveals several challenges in reproducing the time evolution of the short-lived, extreme dust storm events. PMID:29632432

Development of High-Resolution Dynamic Dust Source Function -A Case Study with a Strong Dust Storm in a Regional Model.

PubMed

Kim, Dongchul; Chin, Mian; Kemp, Eric M; Tao, Zhining; Peters-Lidard, Christa D; Ginoux, Paul

2017-06-01

A high-resolution dynamic dust source has been developed in the NASA Unified-Weather Research and Forecasting (NU-WRF) model to improve the existing coarse static dust source. In the new dust source map, topographic depression is in 1-km resolution and surface bareness is derived using the Normalized Difference Vegetation Index (NDVI) data from Moderate Resolution Imaging Spectroradiometer (MODIS). The new dust source better resolves the complex topographic distribution over the Western United States where its magnitude is higher than the existing, coarser resolution static source. A case study is conducted with an extreme dust storm that occurred in Phoenix, Arizona in 02-03 UTC July 6, 2011. The NU-WRF model with the new high-resolution dynamic dust source is able to successfully capture the dust storm, which was not achieved with the old source identification. However the case study also reveals several challenges in reproducing the time evolution of the short-lived, extreme dust storm events.

High Resolution Land Surface Modeling with the next generation Land Data Assimilation Systems

NASA Astrophysics Data System (ADS)

Kumar, S. V.; Eylander, J.; Peters-Lidard, C.

2005-12-01

Knowledge of land surface processes is important to many real-world applications such as agricultural production, water resources management, and flood predication. The Air Force Weather Agency (AFWA) has provided the USDA and other customers global soil moisture and temperature data for the past 30 years using the agrometeorological data assimilation model (now called AGRMET), merging atmospheric data. Further, accurate initialization of land surface conditions has been shown to greatly influence and improve weather forecast model and seasonal-to-interannual climate predictions. The AFWA AGRMET model exploits real time precipitation observations and analyses, global forecast model and satellite data to generate global estimates of soil moisture, soil temperature and other land surface states at 48km spatial resolution. However, to truly address the land surface initialization and climate prediction problem, and to mitigate the errors introduced by the differences in spatial scales of models, representations of land surface conditions need to be developed at the same fine scales such as that of cloud resolving models. NASA's Goddard Space Flight Center has developed an offline land data assimilation system known as the Land Information System (LIS) capable of modeling land atmosphere interactions at spatial resolutions as fine as 1km. LIS provides a software architecture that integrates the use of the state of the art land surface models, data assimilation techniques, and high performance computing and data management tools. LIS also employs many high resolution surface parameters such as the NASA Earth Observing System (EOS)-era products. In this study we describe the development of a next generation high resolution land surface modeling and data assimilation system, combining the capabilities of LIS and AGRMET. We investigate the influence of high resolution land surface data and observations on the land surface conditions by comparing with the operational AGRMET outputs.

Super resolution reconstruction of μ-CT image of rock sample using neighbour embedding algorithm

NASA Astrophysics Data System (ADS)

Wang, Yuzhu; Rahman, Sheik S.; Arns, Christoph H.

2018-03-01

X-ray computed tomography (μ-CT) is considered to be the most effective way to obtain the inner structure of rock sample without destructions. However, its limited resolution hampers its ability to probe sub-micro structures which is critical for flow transportation of rock sample. In this study, we propose an innovative methodology to improve the resolution of μ-CT image using neighbour embedding algorithm where low frequency information is provided by μ-CT image itself while high frequency information is supplemented by high resolution scanning electron microscopy (SEM) image. In order to obtain prior for reconstruction, a large number of image patch pairs contain high- and low- image patches are extracted from the Gaussian image pyramid generated by SEM image. These image patch pairs contain abundant information about tomographic evolution of local porous structures under different resolution spaces. Relying on the assumption of self-similarity of porous structure, this prior information can be used to supervise the reconstruction of high resolution μ-CT image effectively. The experimental results show that the proposed method is able to achieve the state-of-the-art performance.

Image intensification; Proceedings of the Meeting, Los Angeles, CA, Jan. 17, 18, 1989

NASA Astrophysics Data System (ADS)

Csorba, Illes P.

Various papers on image intensification are presented. Individual topics discussed include: status of high-speed optical detector technologies, super second generation imge intensifier, gated image intensifiers and applications, resistive-anode position-sensing photomultiplier tube operational modeling, undersea imaging and target detection with gated image intensifier tubes, image intensifier modules for use with commercially available solid state cameras, specifying the components of an intensified solid state television camera, superconducting IR focal plane arrays, one-inch TV camera tube with very high resolution capacity, CCD-Digicon detector system performance parameters, high-resolution X-ray imaging device, high-output technology microchannel plate, preconditioning of microchannel plate stacks, recent advances in small-pore microchannel plate technology, performance of long-life curved channel microchannel plates, low-noise microchannel plates, development of a quartz envelope heater.

Dual-comb spectroscopy of laser-induced plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bergevin, Jenna; Wu, Tsung-Han; Yeak, Jeremy

Dual-comb spectroscopy has become a powerful spectroscopic technique in applications that rely on its broad spectral coverage combined with high frequency resolution capabilities. Experiments to date have primarily focused on detection and analysis of multiple gas species under semi-static conditions, with applications ranging from environmental monitoring of greenhouse gases to high resolution molecular spectroscopy. Here, we utilize dual-comb spectroscopy to demonstrate broadband, high-resolution, and time-resolved measurements in a laser induced plasma for the first time. As a first demonstration, we simultaneously detect trace amounts of Rb and K in solid samples with a single laser ablation shot, with transitions separatedmore » by over 6 THz (13 nm) and spectral resolution sufficient to resolve isotopic and ground state hyperfine splittings of the Rb D2 line. This new spectroscopic approach offers the broad spectral coverage found in the powerful techniques of laser-induced breakdown spectroscopy (LIBS) while providing the high-resolution and accuracy of cw laser-based spectroscopies.« less

Photoelectron angular distributions from rotationally resolved autoionizing states of N 2

DOE PAGES

Chartrand, A. M.; McCormack, E. F.; Jacovella, U.; ...

2017-12-08

The single-photon, photoelectron-photoion coincidence spectrum of N 2 has been recorded at high (~1.5 cm -1) resolution in the region between the N 2 + X 2Σ g +, v + = 0 and 1 ionization thresholds by using a double imaging spectrometer and intense vacuum-ultraviolet light from the Synchrotron SOLEIL. This approach provides the relative photoionization cross section, the photoelectron energy distribution, and the photoelectron angular distribution as a function of photon energy. The region of interest contains autoionizing valence states, vibrationally autoionizing Rydberg states converging to vibrationally excited levels of the N 2 + X 2Σ g +more » ground state, and electronically autoionizing states converging to the N 2 + A 2Π and B 2Σ u + states. The wavelength resolution is sufficient to resolve rotational structure in the autoionizing states, but the electron energy resolution is insufficient to resolve rotational structure in the photoion spectrum. Here, a simplified approach based on multichannel quantum defect theory is used to predict the photoelectron angular distribution parameters, β, and the results are in reasonably good agreement with experiment.« less

High-resolution neutron diffraction study of CuNCN: New evidence of structure anomalies at low temperature

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacobs, Philipp; Houben, Andreas; Dronskowski, Richard, E-mail: drons@HAL9000.ac.rwth-aachen.de

Copper carbodiimide (CuNCN) is the nitrogen-containing analogue of cupric oxide. Based on high-resolution neutron-diffraction data, CuNCN's lattice parameters are derived as a function of the temperature. In accordance with a recent synchrotron study, a clear trend in the cell parameter a is observed accompanying the changing magnetic behavior. With decreasing temperature, a slowly decreases to a minimum at ∼100 K after which it rises again. The same trend—albeit more pronounced—is observed for the c lattice parameter at ∼35 K. The herein presented neutron powder-diffraction data also support the conjectured sequence of transitions from the high-temperature one-dimensional resonating valence-bond (RVB) statemore » to a transient two-dimensional RVB state and eventually, at lowest temperatures, into another two-dimensional RVB state, presumably the ground state.« less

The Soil Moisture Active Passive (SMAP) Radar: Measurements at High Latitudes and of Surface Freeze/Thaw State

NASA Technical Reports Server (NTRS)

Spencer, Michael; Dunbar, Scott; Chen, Curtis

2013-01-01

The Soil Moisture Active/Passive (SMAP) mission is scheduled for a late 2014 launch date. The mission will use both active radar and passive radiometer instruments at L-Band in order to achieve the science objectives of measuring soil moisture and land surface freeze-thaw state. To achieve requirements for a wide swath at sufficiently high resolution for both active and passive channels, an instrument architecture that uses a large rotating reflector is employed. In this paper, focus will be placed on the radar design. The radar will employ synthetic-aperture processing to achieve a "moderate" resolution dual-pol product over a 1000 km swath. Because the radar is operating continuously, very frequent temporal coverage will be achieved at high latitudes. This data will be used to produce a surface freeze/thaw state data product.

Oxidation-state sensitive imaging of cerium dioxide by atomic-resolution low-angle annular dark field scanning transmission electron microscopy.

PubMed

Johnston-Peck, Aaron C; Winterstein, Jonathan P; Roberts, Alan D; DuChene, Joseph S; Qian, Kun; Sweeny, Brendan C; Wei, Wei David; Sharma, Renu; Stach, Eric A; Herzing, Andrew A

2016-03-01

Low-angle annular dark field (LAADF) scanning transmission electron microscopy (STEM) imaging is presented as a method that is sensitive to the oxidation state of cerium ions in CeO2 nanoparticles. This relationship was validated through electron energy loss spectroscopy (EELS), in situ measurements, as well as multislice image simulations. Static displacements caused by the increased ionic radius of Ce(3+) influence the electron channeling process and increase electron scattering to low angles while reducing scatter to high angles. This process manifests itself by reducing the high-angle annular dark field (HAADF) signal intensity while increasing the LAADF signal intensity in close proximity to Ce(3+) ions. This technique can supplement STEM-EELS and in so doing, relax the experimental challenges associated with acquiring oxidation state information at high spatial resolutions. Published by Elsevier B.V.

Three-dimensional nature of the band structure of ZrTe 5 measured by high-momentum-resolution photoemission spectroscopy [3D nature ZrTe 5 band structure measured by high-momentum-resolution photoemission spectroscopy

DOE PAGES

Xiong, H.; Sobota, J. A.; Yang, S. -L.; ...

2017-05-10

Here, we have performed a systematic high-momentum-resolution photoemission study on ZrTe 5 using 6-eV photon energy. We have measured the band structure near the Γ point, and quantified the gap between the conduction and valence band as 18 ≤ Δ ≤ 29 meV. We have also observed photon-energy-dependent behavior attributed to final-state effects and the three-dimensional (3D) nature of the material's band structure. Our interpretation indicates the gap is intrinsic and reconciles discrepancies on the existence of a topological surface state reported by different studies. The existence of a gap suggests that ZrTe 5 is not a 3D strong topologicalmore » insulator nor a 3D Dirac semimetal. Therefore, our experiment is consistent with ZrTe 5 being a 3D weak topological insulator.« less

Adding polarimetric imaging to depth map using improved light field camera 2.0 structure

NASA Astrophysics Data System (ADS)

Zhang, Xuanzhe; Yang, Yi; Du, Shaojun; Cao, Yu

2017-06-01

Polarization imaging plays an important role in various fields, especially for skylight navigation and target identification, whose imaging system is always required to be designed with high resolution, broad band, and single-lens structure. This paper describe such a imaging system based on light field 2.0 camera structure, which can calculate the polarization state and depth distance from reference plane for every objet point within a single shot. This structure, including a modified main lens, a multi-quadrants Polaroid, a honeycomb-liked micro lens array, and a high resolution CCD, is equal to an "eyes array", with 3 or more polarization imaging "glasses" in front of each "eye". Therefore, depth can be calculated by matching the relative offset of corresponding patch on neighboring "eyes", while polarization state by its relative intensity difference, and their resolution will be approximately equal to each other. An application on navigation under clear sky shows that this method has a high accuracy and strong robustness.

Three-dimensional nature of the band structure of ZrTe 5 measured by high-momentum-resolution photoemission spectroscopy [3D nature ZrTe 5 band structure measured by high-momentum-resolution photoemission spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xiong, H.; Sobota, J. A.; Yang, S. -L.

Here, we have performed a systematic high-momentum-resolution photoemission study on ZrTe 5 using 6-eV photon energy. We have measured the band structure near the Γ point, and quantified the gap between the conduction and valence band as 18 ≤ Δ ≤ 29 meV. We have also observed photon-energy-dependent behavior attributed to final-state effects and the three-dimensional (3D) nature of the material's band structure. Our interpretation indicates the gap is intrinsic and reconciles discrepancies on the existence of a topological surface state reported by different studies. The existence of a gap suggests that ZrTe 5 is not a 3D strong topologicalmore » insulator nor a 3D Dirac semimetal. Therefore, our experiment is consistent with ZrTe 5 being a 3D weak topological insulator.« less

Single image super-resolution via regularized extreme learning regression for imagery from microgrid polarimeters

NASA Astrophysics Data System (ADS)

Sargent, Garrett C.; Ratliff, Bradley M.; Asari, Vijayan K.

2017-08-01

The advantage of division of focal plane imaging polarimeters is their ability to obtain temporally synchronized intensity measurements across a scene; however, they sacrifice spatial resolution in doing so due to their spatially modulated arrangement of the pixel-to-pixel polarizers and often result in aliased imagery. Here, we propose a super-resolution method based upon two previously trained extreme learning machines (ELM) that attempt to recover missing high frequency and low frequency content beyond the spatial resolution of the sensor. This method yields a computationally fast and simple way of recovering lost high and low frequency content from demosaicing raw microgrid polarimetric imagery. The proposed method outperforms other state-of-the-art single-image super-resolution algorithms in terms of structural similarity and peak signal-to-noise ratio.

A 16-year time series of 1 km AVHRR satellite data of the conterminous United States and Alaska

USGS Publications Warehouse

Eidenshink, Jeff

2006-01-01

The U.S. Geological Survey (USGS) has developed a 16-year time series of vegetation condition information for the conterminous United States and Alaska using 1 km Advanced Very High Resolution Radiometer (AVHRR) data. The AVHRR data have been processed using consistent methods that account for radiometric variability due to calibration uncertainty, the effects of the atmosphere on surface radiometric measurements obtained from wide field-of-view observations, and the geometric registration accuracy. The conterminous United States and Alaska data sets have an atmospheric correction for water vapor, ozone, and Rayleigh scattering and include a cloud mask derived using the Clouds from AVHRR (CLAVR) algorithm. In comparison with other AVHRR time series data sets, the conterminous United States and Alaska data are processed using similar techniques. The primary difference is that the conterminous United States and Alaska data are at 1 km resolution, while others are at 8 km resolution. The time series consists of weekly and biweekly maximum normalized difference vegetation index (NDVI) composites.

Excited-state lifetime measurement of silicon vacancy centers in diamond by single-photon frequency upconversion

NASA Astrophysics Data System (ADS)

Rong, Youying; Ma, Jianhui; Chen, Lingxiao; Liu, Yan; Siyushev, Petr; Wu, Botao; Pan, Haifeng; Jelezko, Fedor; Wu, E.; Zeng, Heping

2018-05-01

We report a method with high time resolution to measure the excited-state lifetime of silicon vacancy centers in bulk diamond avoiding timing jitter from the single-photon detectors. Frequency upconversion of the fluorescence emitted from silicon vacancy centers was achieved from 738 nm to 436 nm via sum frequency generation with a short pump pulse. The excited-state lifetime can be obtained by measuring the intensity of upconverted light while the pump delay changes. As a probe, a pump laser with pulse duration of 11 ps provided a high temporal resolution of the measurement. The lifetime extracted from the pump–probe curve was 0.755 ns, which was comparable to the timing jitter of the single-photon detectors.

Circuit for high resolution decoding of multi-anode microchannel array detectors

NASA Technical Reports Server (NTRS)

Kasle, David B. (Inventor)

1995-01-01

A circuit for high resolution decoding of multi-anode microchannel array detectors consisting of input registers accepting transient inputs from the anode array; anode encoding logic circuits connected to the input registers; midpoint pipeline registers connected to the anode encoding logic circuits; and pixel decoding logic circuits connected to the midpoint pipeline registers is described. A high resolution algorithm circuit operates in parallel with the pixel decoding logic circuit and computes a high resolution least significant bit to enhance the multianode microchannel array detector's spatial resolution by halving the pixel size and doubling the number of pixels in each axis of the anode array. A multiplexer is connected to the pixel decoding logic circuit and allows a user selectable pixel address output according to the actual multi-anode microchannel array detector anode array size. An output register concatenates the high resolution least significant bit onto the standard ten bit pixel address location to provide an eleven bit pixel address, and also stores the full eleven bit pixel address. A timing and control state machine is connected to the input registers, the anode encoding logic circuits, and the output register for managing the overall operation of the circuit.

DIVERSITY OF ECOLOGICAL COMMUNITIES OF THE UNITED STATES

EPA Science Inventory

Biodiversity, although recognized as encompassing several levels of biological organization, is often thought of as species diversity. Three diversity estimates were calculated for the conterminous United States using satellite data acquired from the Advanced Very High Resolution...

High-resolution magnetic resonance spectroscopy using a solid-state spin sensor

NASA Astrophysics Data System (ADS)

Glenn, David R.; Bucher, Dominik B.; Lee, Junghyun; Lukin, Mikhail D.; Park, Hongkun; Walsworth, Ronald L.

2018-03-01

Quantum systems that consist of solid-state electronic spins can be sensitive detectors of nuclear magnetic resonance (NMR) signals, particularly from very small samples. For example, nitrogen–vacancy centres in diamond have been used to record NMR signals from nanometre-scale samples, with sensitivity sufficient to detect the magnetic field produced by a single protein. However, the best reported spectral resolution for NMR of molecules using nitrogen–vacancy centres is about 100 hertz. This is insufficient to resolve the key spectral identifiers of molecular structure that are critical to NMR applications in chemistry, structural biology and materials research, such as scalar couplings (which require a resolution of less than ten hertz) and small chemical shifts (which require a resolution of around one part per million of the nuclear Larmor frequency). Conventional, inductively detected NMR can provide the necessary high spectral resolution, but its limited sensitivity typically requires millimetre-scale samples, precluding applications that involve smaller samples, such as picolitre-volume chemical analysis or correlated optical and NMR microscopy. Here we demonstrate a measurement technique that uses a solid-state spin sensor (a magnetometer) consisting of an ensemble of nitrogen–vacancy centres in combination with a narrowband synchronized readout protocol to obtain NMR spectral resolution of about one hertz. We use this technique to observe NMR scalar couplings in a micrometre-scale sample volume of approximately ten picolitres. We also use the ensemble of nitrogen–vacancy centres to apply NMR to thermally polarized nuclear spins and resolve chemical-shift spectra from small molecules. Our technique enables analytical NMR spectroscopy at the scale of single cells.

High-resolution two-photon spectroscopy of a 5 p56 p ←5 p6 transition of xenon

NASA Astrophysics Data System (ADS)

Altiere, Emily; Miller, Eric R.; Hayamizu, Tomohiro; Jones, David J.; Madison, Kirk W.; Momose, Takamasa

2018-01-01

We report high-resolution Doppler-free two-photon excitation spectroscopy of Xe from the ground state to the 5 p5(P 3 /2 2 ) 6 p [3 /2 ] 2 2 electronic excited state. This is a first step to developing a comagnetometer using polarized 129Xe atoms for planned neutron electric dipole moment measurements at TRIUMF. Narrow linewidth radiation at 252.5 nm produced by a continuous wave laser was built up in an optical cavity to excite the two-photon transition, and the near-infrared emission from the 5 p56 p excited state to the 5 p56 s intermediate electronic state was used to detect the two-photon transition. Hyperfine constants and isotope shift parameters were evaluated and compared with previously reported values. In addition, the detected photon count rate was estimated from the observed intensities.

PEPSI, the High-Resolution Optical-IR Spectrograph for the LBT

NASA Astrophysics Data System (ADS)

Andersen, Michael; Strassmeier, Klaus; Hoffman, Axel; Woche, Manfred; Spano, Paolo

PEPSI is a high resolution fibre feed optical-IR polarimetric echelle spectrograph for the Large Binocular Telescope (LBT). PEPSI utilizes the two 8.4m LBT apertures to simultaneously record four polarization states at a resolution of 120.000. The extension of the coverage towards the IR is mainly motivated by the larger Zeeman splitting of IR lines, which would allow to study weaker/fainter magnetic structures on stars. The two optical arms, which also have an integral light mode with R up to 300.000, are under construction, while the IR arm is being designed.

Development of New High Resolution Neutron Detector

NASA Astrophysics Data System (ADS)

Mostella, L. D., III; Rajabali, M.; Loureiro, D. P.; Grzywacz, R.

2017-09-01

Beta-delayed neutron emission is a prevalent form of decay for neutron-rich nuclei. This occurs when an unstable nucleus undergoes beta decay, but produces a daughter nucleus in an excited state above the neutron separation energy. The daughter nucleus then de-excites by ejecting one or more neutrons. We wish to map the states from which these nuclei decay via neutron spectroscopy using NEXT, a new high resolution neutron detector. NEXT utilizes silicon photomultipliers and 6 mm thick pulse-shape discriminating plastic scintillators, allowing for smaller and more compact modular geometries in the NEXT array. Timing measurements for the detector were performed and a resolution of 893 ps (FWHM) has been achieved so far. Aspects of the detector that were investigated and will be presented here include scintillator geometry, wrapping materials, fitting functions for the digitized signals, and electronic components coupled to the silicon photomultipliers for signal shaping.

Probing hydrogen bond potentials via combination band spectroscopy: A near infrared study of the geared bend/van der Waals stretch intermolecular modes in (HF)2

NASA Astrophysics Data System (ADS)

Anderson, David T.; Davis, Scott; Nesbitt, David J.

1996-04-01

High resolution near infrared spectra of the two lowest frequency intermolecular modes in HF-stretch excited states of (HF)2 have been characterized using a slit-jet infrared spectrometer. In the spectral region surveyed, ten vibration-rotation-tunneling (VRT) bands are observed and assigned to the low frequency ``van der Waals stretch'' (ν4) and ``geared bend'' (ν5) intermolecular modes, in combination with either the hydrogen bond acceptor (ν1) or donor (ν2) high-frequency intramolecular HF stretches. Analysis of the rotationally resolved spectra provide intermolecular frequencies, rotational constants, tunneling splittings, and predissociation rates for the ν4/ν5 intermolecular excited states. The intermolecular vibrational frequencies in the combination states display a systematic dependence on intramolecular redshift that allows far-IR intermolecular frequencies to be reliably extrapolated from the near-IR data. Approximately tenfold increases in the hydrogen bond interconversion tunneling splittings with either ν4 or ν5 excitation indicate that both intermolecular modes correlate strongly to the tunneling coordinate. The high resolution VRT line shapes reveal mode specific predissociation broadening sensitive predominantly to intramolecular excitation, with weaker but significant additional effects due to low frequency intermolecular excitation. Analysis of the high resolution spectroscopic data for these ν4 and ν5 combination bands suggests strong state mixing between what has previously been considered van der Waals stretch and geared bend degrees of freedom.

Respiratory syncytial virus tracking using internet search engine data.

PubMed

Oren, Eyal; Frere, Justin; Yom-Tov, Eran; Yom-Tov, Elad

2018-04-03

Respiratory Syncytial Virus (RSV) is the leading cause of hospitalization in children less than 1 year of age in the United States. Internet search engine queries may provide high resolution temporal and spatial data to estimate and predict disease activity. After filtering an initial list of 613 symptoms using high-resolution Bing search logs, we used Google Trends data between 2004 and 2016 for a smaller list of 50 terms to build predictive models of RSV incidence for five states where long-term surveillance data was available. We then used domain adaptation to model RSV incidence for the 45 remaining US states. Surveillance data sources (hospitalization and laboratory reports) were highly correlated, as were laboratory reports with search engine data. The four terms which were most often statistically significantly correlated as time series with the surveillance data in the five state models were RSV, flu, pneumonia, and bronchiolitis. Using our models, we tracked the spread of RSV by observing the time of peak use of the search term in different states. In general, the RSV peak moved from south-east (Florida) to the north-west US. Our study represents the first time that RSV has been tracked using Internet data results and highlights successful use of search filters and domain adaptation techniques, using data at multiple resolutions. Our approach may assist in identifying spread of both local and more widespread RSV transmission and may be applicable to other seasonal conditions where comprehensive epidemiological data is difficult to collect or obtain.

Superconducting gamma and fast-neutron spectrometers with high energy resolution

DOEpatents

Friedrich, Stephan; , Niedermayr, Thomas R.; Labov, Simon E.

2008-11-04

Superconducting Gamma-ray and fast-neutron spectrometers with very high energy resolution operated at very low temperatures are provided. The sensor consists of a bulk absorber and a superconducting thermometer weakly coupled to a cold reservoir, and determines the energy of the incident particle from the rise in temperature upon absorption. A superconducting film operated at the transition between its superconducting and its normal state is used as the thermometer, and sensor operation at reservoir temperatures around 0.1 K reduces thermal fluctuations and thus enables very high energy resolution. Depending on the choice of absorber material, the spectrometer can be configured either as a Gamma-spectrometer or as a fast-neutron spectrometer.

Estimate of the Coulomb correlation energy in CeAg2Ge2 from inverse photoemission and high resolution photoemission spectroscopy

NASA Astrophysics Data System (ADS)

Banik, Soma; Arya, A.; Bendounan, Azzedine; Maniraj, M.; Thamizhavel, A.; Vobornik, I.; Dhar, S. K.; Deb, S. K.

2014-08-01

The occupied and the unoccupied electronic structure of CeAg2Ge2 single crystal has been studied using high resolution photoemission and inverse photoemission spectroscopy, respectively. High resolution photoemission reveals the clear signature of Ce 4f states in the occupied electronic structure which was not observed clearly in our earlier studies. The Coulomb correlation energy in this system has been determined experimentally from the position of the 4f states above and below the Fermi level. Theoretically, the correlation energy has been determined by using the first principles density functional calculations within the generalized gradient approximations taking into account the strong intra-atomic (on-site) interaction Hubbard Ueff term. The calculated valence band shows minor changes in the spectral shape with increasing Ueff due to the fact that the density of Ce 4f state is narrow in the occupied part and is hybridized with the Ce 5d, Ag 4d and Ge 4p states. On the other hand, substantial changes are observed in the spectral shape of the calculated conduction band with increasing Ueff since the density of Ce 4f state is very large in the unoccupied part, compared to other states. The estimated value of correlation energy for CeAg2Ge2 from the experiment and the theory is ≈ 4.2 eV. The resonant photoemission data are analyzed in the framework of the single-impurity Anderson model which further confirms the presence of the Coulomb correlation energy and small hybridization in this system.

Errors on interrupter tasks presented during spatial and verbal working memory performance are linearly linked to large-scale functional network connectivity in high temporal resolution resting state fMRI.

PubMed

Magnuson, Matthew Evan; Thompson, Garth John; Schwarb, Hillary; Pan, Wen-Ju; McKinley, Andy; Schumacher, Eric H; Keilholz, Shella Dawn

2015-12-01

The brain is organized into networks composed of spatially separated anatomical regions exhibiting coherent functional activity over time. Two of these networks (the default mode network, DMN, and the task positive network, TPN) have been implicated in the performance of a number of cognitive tasks. To directly examine the stable relationship between network connectivity and behavioral performance, high temporal resolution functional magnetic resonance imaging (fMRI) data were collected during the resting state, and behavioral data were collected from 15 subjects on different days, exploring verbal working memory, spatial working memory, and fluid intelligence. Sustained attention performance was also evaluated in a task interleaved between resting state scans. Functional connectivity within and between the DMN and TPN was related to performance on these tasks. Decreased TPN resting state connectivity was found to significantly correlate with fewer errors on an interrupter task presented during a spatial working memory paradigm and decreased DMN/TPN anti-correlation was significantly correlated with fewer errors on an interrupter task presented during a verbal working memory paradigm. A trend for increased DMN resting state connectivity to correlate to measures of fluid intelligence was also observed. These results provide additional evidence of the relationship between resting state networks and behavioral performance, and show that such results can be observed with high temporal resolution fMRI. Because cognitive scores and functional connectivity were collected on nonconsecutive days, these results highlight the stability of functional connectivity/cognitive performance coupling.

Enzyme Active Site Interactions by Raman/FTIR, NMR, and Ab Initio Calculations

PubMed Central

Deng, Hua

2017-01-01

Characterization of enzyme active site structure and interactions at high resolution is important for the understanding of the enzyme catalysis. Vibrational frequency and NMR chemical shift measurements of enzyme-bound ligands are often used for such purpose when X-ray structures are not available or when higher resolution active site structures are desired. This review is focused on how ab initio calculations may be integrated with vibrational and NMR chemical shift measurements to quantitatively determine high-resolution ligand structures (up to 0.001 Å for bond length and 0.01 Å for hydrogen bonding distance) and how interaction energies between bound ligand and its surroundings at the active site may be determined. Quantitative characterization of substrate ionic states, bond polarizations, tautomeric forms, conformational changes and its interactions with surroundings in enzyme complexes that mimic ground state or transition state can provide snapshots for visualizing the substrate structural evolution along enzyme-catalyzed reaction pathway. Our results have shown that the integration of spectroscopic studies with theoretical computation greatly enhances our ability to interpret experimental data and significantly increases the reliability of the theoretical analysis. PMID:24018325

Evaluation of High Resolution Rapid Refresh-Smoke (HRRR-Smoke) model products for a case study using surface PM2.5 observations

NASA Astrophysics Data System (ADS)

Deanes, L. N.; Ahmadov, R.; McKeen, S. A.; Manross, K.; Grell, G. A.; James, E.

2016-12-01

Wildfires are increasing in number and size in the western United States as climate change contributes to warmer and drier conditions in this region. These fires lead to poor air quality and diminished visibility. The High Resolution Rapid Refresh-Smoke modeling system (HRRR-Smoke) is designed to simulate fire emissions and smoke transport with high resolution. The model is based on the Weather Research and Forecasting model, coupled with chemistry (WRF-Chem) and uses fire detection data from the Visible Infrared and Imaging Radiometer Suite (VIIRS) satellite instrument to simulate wildfire emissions and their plume rise. HRRR-Smoke is used in both real-time applications and case studies. In this study, we evaluate the HRRR-Smoke for August 2015, during one of the worst wildfire seasons on record in the United States, by focusing on wildfires that occurred in the northwestern US. We compare HRRR-Smoke simulations with hourly fine particulate matter (PM2.5) observations from the Air Quality System (https://www.epa.gov/aqs) from multiple air quality monitoring sites in Washington state. PM2.5 data includes measurements from urban, suburban and remote sites in the state. We discuss the model performance in capturing large PM2.5 enhancements detected at surface sites due to wildfires. We present various statistical parameters to demonstrate HRRR-Smoke's performance in simulating surface PM2.5 levels.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chartrand, A. M.; McCormack, E. F.; Jacovella, U.

The single-photon, photoelectron-photoion coincidence spectrum of N 2 has been recorded at high (~1.5 cm -1) resolution in the region between the N 2 + X 2Σ g +, v + = 0 and 1 ionization thresholds by using a double imaging spectrometer and intense vacuum-ultraviolet light from the Synchrotron SOLEIL. This approach provides the relative photoionization cross section, the photoelectron energy distribution, and the photoelectron angular distribution as a function of photon energy. The region of interest contains autoionizing valence states, vibrationally autoionizing Rydberg states converging to vibrationally excited levels of the N 2 + X 2Σ g +more » ground state, and electronically autoionizing states converging to the N 2 + A 2Π and B 2Σ u + states. The wavelength resolution is sufficient to resolve rotational structure in the autoionizing states, but the electron energy resolution is insufficient to resolve rotational structure in the photoion spectrum. Here, a simplified approach based on multichannel quantum defect theory is used to predict the photoelectron angular distribution parameters, β, and the results are in reasonably good agreement with experiment.« less

High-resolution infrared spectrum of triacetylene: The ν5 state revisited and new vibrational states

NASA Astrophysics Data System (ADS)

Doney, K. D.; Zhao, D.; Linnartz, H.

2015-10-01

New data are presented that follow from a high-resolution survey, from 3302 to 3352 cm-1, through expanding acetylene plasma, and covering the Csbnd H asymmetric (ν5) fundamental band of triacetylene (HC6H). Absorption signals are recorded using continuous wave cavity ring-down spectroscopy (cw-CRDS). A detailed analysis of the resulting spectra allows revisiting the molecular parameters of the ν5 fundamental band in terms of interactions with a perturbing state, which is observed for the first time. Moreover, four fully resolved hot bands (501 1011, 501 1111, 501 1311, and 101 801 1110), with band origins at 3328.5829(2), 3328.9994(2), 3328.2137(2) and 3310.8104(2) cm-1, respectively, are reported for the first time. These involve low lying bending vibrations that have been studied previously, which guarantees unambiguous identifications. Combining available data allows to derive accurate molecular parameters, both for the ground state as well as the excited states involved in the bands.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Fuyu; Collins, William D.; Wehner, Michael F.

High-resolution climate models have been shown to improve the statistics of tropical storms and hurricanes compared to low-resolution models. The impact of increasing horizontal resolution in the tropical storm simulation is investigated exclusively using a series of Atmospheric Global Climate Model (AGCM) runs with idealized aquaplanet steady-state boundary conditions and a fixed operational storm-tracking algorithm. The results show that increasing horizontal resolution helps to detect more hurricanes, simulate stronger extreme rainfall, and emulate better storm structures in the models. However, increasing model resolution does not necessarily produce stronger hurricanes in terms of maximum wind speed, minimum sea level pressure, andmore » mean precipitation, as the increased number of storms simulated by high-resolution models is mainly associated with weaker storms. The spatial scale at which the analyses are conducted appears to have more important control on these meteorological statistics compared to horizontal resolution of the model grid. When the simulations are analyzed on common low-resolution grids, the statistics of the hurricanes, particularly the hurricane counts, show reduced sensitivity to the horizontal grid resolution and signs of scale invariant.« less

Monitoring vegetation greenness with satellite data

Treesearch

Robert E. Burgan; Roberta A. Hartford

1993-01-01

Vegetation greenness can be monitored at 1-km resolution for the conterminous United States through data obtained from the Advanced Very High Resolution Radiometer on the NOAA-11 weather satellites. The data are used to calculate biweekly composites of the Normalized Difference Vegetation Index. The resulting composite images are updated weekly and made available to...

The Soil Moisture Active Passive (SMAP): Radar Measurements at High Latitudes and of Freeze/Thaw State

NASA Technical Reports Server (NTRS)

Spencer, Michael; Dunbar, Scott; Chen, Curtis

2013-01-01

The Soil Moisture Active/Passive (SMAP) mission is scheduled for a late 2014 launch date. The mission will use both active radar and passive radiometer instruments at L-Band. In order to achieve a wide swath at sufficiently high resolution for both active and passive channels, an instrument architecture that uses a large rotating reflector is employed. In this paper, a focus will be places on the radar design and associated data products at high latitudes. The radar will employ synthetic-aperture processing to achieve a "moderate" resolution dual-pol product over a 1000 km swath. Because the radar is operating continuously, very frequent temporal coverage will be achieved at high latitudes. This data will be used, among other things, to produce a surface freeze/thaw state data product.

Deriving Continuous Fields of Tree Cover at 1-m over the Continental United States From the National Agriculture Imagery Program (NAIP) Imagery to Reduce Uncertainties in Forest Carbon Stock Estimation

NASA Astrophysics Data System (ADS)

Ganguly, S.; Basu, S.; Mukhopadhyay, S.; Michaelis, A.; Milesi, C.; Votava, P.; Nemani, R. R.

2013-12-01

An unresolved issue with coarse-to-medium resolution satellite-based forest carbon mapping over regional to continental scales is the high level of uncertainty in above ground biomass (AGB) estimates caused by the absence of forest cover information at a high enough spatial resolution (current spatial resolution is limited to 30-m). To put confidence in existing satellite-derived AGB density estimates, it is imperative to create continuous fields of tree cover at a sufficiently high resolution (e.g. 1-m) such that large uncertainties in forested area are reduced. The proposed work will provide means to reduce uncertainty in present satellite-derived AGB maps and Forest Inventory and Analysis (FIA) based regional estimates. Our primary objective will be to create Very High Resolution (VHR) estimates of tree cover at a spatial resolution of 1-m for the Continental United States using all available National Agriculture Imaging Program (NAIP) color-infrared imagery from 2010 till 2012. We will leverage the existing capabilities of the NASA Earth Exchange (NEX) high performance computing and storage facilities. The proposed 1-m tree cover map can be further aggregated to provide percent tree cover at any medium-to-coarse resolution spatial grid, which will aid in reducing uncertainties in AGB density estimation at the respective grid and overcome current limitations imposed by medium-to-coarse resolution land cover maps. We have implemented a scalable and computationally-efficient parallelized framework for tree-cover delineation - the core components of the algorithm [that] include a feature extraction process, a Statistical Region Merging image segmentation algorithm and a classification algorithm based on Deep Belief Network and a Feedforward Backpropagation Neural Network algorithm. An initial pilot exercise has been performed over the state of California (~11,000 scenes) to create a wall-to-wall 1-m tree cover map and the classification accuracy has been assessed. Results show an improvement in accuracy of tree-cover delineation as compared to existing forest cover maps from NLCD, especially over fragmented, heterogeneous and urban landscapes. Estimates of VHR tree cover will complement and enhance the accuracy of present remote-sensing based AGB modeling approaches and forest inventory based estimates at both national and local scales. A requisite step will be to characterize the inherent uncertainties in tree cover estimates and propagate them to estimate AGB.

High Resolution Regional Climate Simulations over Alaska

NASA Astrophysics Data System (ADS)

Monaghan, A. J.; Clark, M. P.; Arnold, J.; Newman, A. J.; Musselman, K. N.; Barlage, M. J.; Xue, L.; Liu, C.; Gutmann, E. D.; Rasmussen, R.

2016-12-01

In order to appropriately plan future projects to build and maintain infrastructure (e.g., dams, dikes, highways, airports), a number of U.S. federal agencies seek to better understand how hydrologic regimes may shift across the country due to climate change. Building on the successful completion of a series of high-resolution WRF simulations over the Colorado River Headwaters and contiguous USA, our team is now extending these simulations over the challenging U.S. States of Alaska and Hawaii. In this presentation we summarize results from a newly completed 4-km resolution WRF simulation over Alaska spanning 2002-2016 at 4-km spatial resolution. Our aim is to gain insight into the thermodynamics that drive key precipitation processes, particularly the extremes that are most damaging to infrastructure.

Bendable X-ray Optics for High Resolution Imaging

NASA Technical Reports Server (NTRS)

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

2014-01-01

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

Complete (1)H resonance assignment of beta-maltose from (1)H-(1)H DQ-SQ CRAMPS and (1)H (DQ-DUMBO)-(13)C SQ refocused INEPT 2D solid-state NMR spectra and first principles GIPAW calculations.

PubMed

Webber, Amy L; Elena, Bénédicte; Griffin, John M; Yates, Jonathan R; Pham, Tran N; Mauri, Francesco; Pickard, Chris J; Gil, Ana M; Stein, Robin; Lesage, Anne; Emsley, Lyndon; Brown, Steven P

2010-07-14

A disaccharide is a challenging case for high-resolution (1)H solid-state NMR because of the 24 distinct protons (14 aliphatic and 10 OH) having (1)H chemical shifts that all fall within a narrow range of approximately 3 to 7 ppm. High-resolution (1)H (500 MHz) double-quantum (DQ) combined rotation and multiple pulse sequence (CRAMPS) solid-state NMR spectra of beta-maltose monohydrate are presented. (1)H-(1)H DQ-SQ CRAMPS spectra are presented together with (1)H (DQ)-(13)C correlation spectra obtained with a new pulse sequence that correlates a high-resolution (1)H DQ dimension with a (13)C single quantum (SQ) dimension using the refocused INEPT pulse-sequence element to transfer magnetization via one-bond (13)C-(1)H J couplings. Compared to the observation of only a single broad peak in a (1)H DQ spectrum recorded at 30 kHz magic-angle spinning (MAS), the use of DUMBO (1)H homonuclear decoupling in the (1)H DQ CRAMPS experiment allows the resolution of distinct DQ correlation peaks which, in combination with first-principles chemical shift calculations based on the GIPAW (Gauge Including Projector Augmented Waves) plane-wave pseudopotential approach, enables the assignment of the (1)H resonances to the 24 distinct protons. We believe this to be the first experimental solid-state NMR determination of the hydroxyl OH (1)H chemical shifts for a simple sugar. Variable-temperature (1)H-(1)H DQ CRAMPS spectra reveal small increases in the (1)H chemical shifts of the OH resonances upon decreasing the temperature from 348 K to 248 K.

Reconstructing the 20th century high-resolution climate of the southeastern United States

NASA Astrophysics Data System (ADS)

Dinapoli, Steven M.; Misra, Vasubandhu

2012-10-01

We dynamically downscale the 20th Century Reanalysis (20CR) to a 10-km grid resolution from 1901 to 2008 over the southeastern United States and the Gulf of Mexico using the Regional Spectral Model. The downscaled data set, which we call theFlorida Climate Institute-Florida State University Land-Atmosphere Reanalysis for theSoutheastern United States at 10-km resolution (FLAReS1.0), will facilitate the study of the effects of low-frequency climate variability and major historical climate events on local hydrology and agriculture. To determine the suitability of the FLAReS1.0 downscaled data set for any subsequent applied climate studies, we compare the annual, seasonal, and diurnal variability of temperature and precipitation in the model to various observation data sets. In addition, we examine the model's depiction of several meteorological phenomena that affect the climate of the region, including extreme cold waves, summer sea breezes and associated convective activity, tropical cyclone landfalls, and midlatitude frontal systems. Our results show that temperature and precipitation variability are well-represented by FLAReS1.0 on most time scales, although systematic biases do exist in the data. FLAReS1.0 accurately portrays some of the major weather phenomena in the region, but the severity of extreme weather events is generally underestimated. The high resolution of FLAReS1.0 makes it more suitable for local climate studies than the coarser 20CR.

A CMOS-based large-area high-resolution imaging system for high-energy x-ray applications

NASA Astrophysics Data System (ADS)

Rodricks, Brian; Fowler, Boyd; Liu, Chiao; Lowes, John; Haeffner, Dean; Lienert, Ulrich; Almer, John

2008-08-01

CCDs have been the primary sensor in imaging systems for x-ray diffraction and imaging applications in recent years. CCDs have met the fundamental requirements of low noise, high-sensitivity, high dynamic range and spatial resolution necessary for these scientific applications. State-of-the-art CMOS image sensor (CIS) technology has experienced dramatic improvements recently and their performance is rivaling or surpassing that of most CCDs. The advancement of CIS technology is at an ever-accelerating pace and is driven by the multi-billion dollar consumer market. There are several advantages of CIS over traditional CCDs and other solid-state imaging devices; they include low power, high-speed operation, system-on-chip integration and lower manufacturing costs. The combination of superior imaging performance and system advantages makes CIS a good candidate for high-sensitivity imaging system development. This paper will describe a 1344 x 1212 CIS imaging system with a 19.5μm pitch optimized for x-ray scattering studies at high-energies. Fundamental metrics of linearity, dynamic range, spatial resolution, conversion gain, sensitivity are estimated. The Detective Quantum Efficiency (DQE) is also estimated. Representative x-ray diffraction images are presented. Diffraction images are compared against a CCD-based imaging system.

Superconducting High Resolution Fast-Neutron Spectrometers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hau, Ionel Dragos

2006-01-01

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

High efficiency video coding for ultrasound video communication in m-health systems.

PubMed

Panayides, A; Antoniou, Z; Pattichis, M S; Pattichis, C S; Constantinides, A G

2012-01-01

Emerging high efficiency video compression methods and wider availability of wireless network infrastructure will significantly advance existing m-health applications. For medical video communications, the emerging video compression and network standards support low-delay and high-resolution video transmission, at the clinically acquired resolution and frame rates. Such advances are expected to further promote the adoption of m-health systems for remote diagnosis and emergency incidents in daily clinical practice. This paper compares the performance of the emerging high efficiency video coding (HEVC) standard to the current state-of-the-art H.264/AVC standard. The experimental evaluation, based on five atherosclerotic plaque ultrasound videos encoded at QCIF, CIF, and 4CIF resolutions demonstrates that 50% reductions in bitrate requirements is possible for equivalent clinical quality.

(14)N overtone transition in double rotation solid-state NMR.

PubMed

Haies, Ibraheem M; Jarvis, James A; Brown, Lynda J; Kuprov, Ilya; Williamson, Philip T F; Carravetta, Marina

2015-10-07

Solid-state NMR transitions involving outer energy levels of the spin-1 (14)N nucleus are immune, to first order in perturbation theory, to the broadening caused by the nuclear quadrupole interaction. The corresponding overtone spectra, when acquired in conjunction with magic-angle sample spinning, result in lines, which are just a few kHz wide, permitting the direct detection of nitrogen compounds without the need for labeling. Despite the success of this technique, "overtone" resonances are still broadened due to indirect, second order effects arising from the large quadrupolar interaction. Here we demonstrate that another order of magnitude in spectral resolution may be gained by using double rotation. This brings the width of the (14)N solid-state NMR lines much closer to the region commonly associated with high-resolution solid-state NMR spectroscopy of (15)N and demonstrates the improvements in resolution that may be possible through the development of pulsed methodologies to suppress these second order effects.

HIGH RESOLUTION SPECTROSCOPY IN THE GAS PHASE: Even Large Molecules Have Well-Defined Shapes

NASA Astrophysics Data System (ADS)

Pratt, David W.

1998-10-01

A review of recent high-resolution microwave, infrared, and optical spectroscopy experiments demonstrates that remarkable progress has been made in the past 20 years in determining the equilibrium geometries of large polyatomic molecules and their clusters in the gas phase, and how these geometries change when the photon is absorbed. A special focus is on the dynamical information that can be obtained from such studies, particularly of electronically excited states.

Structure of Ce2RhIn8: an example of complementary use of high-resolution neutron powder diffraction and reciprocal-space mapping to study complex materials.

PubMed

Moshopoulou, E G; Ibberson, R M; Sarrao, J L; Thompson, J D; Fisk, Z

2006-04-01

The room-temperature crystal structure of the heavy fermion antiferromagnet Ce2RhIn8, dicerium rhodium octaindide, has been studied by a combination of high-resolution synchrotron X-ray reciprocal-space mapping of single crystals and high-resolution time-of-flight neutron powder diffraction. The structure is disordered, exhibiting a complex interplay of non-periodic, partially correlated planar defects, coexistence and segregation of polytypic phases (induced by periodic planar ;defects'), mosaicity (i.e. domain misalignment) and non-uniform strain. These effects evolve as a function of temperature in a complicated way, but they remain down to low temperatures. The room-temperature diffraction data are best represented by a complex mixture of two polytypic phases, which are affected by non-periodic, partially correlated planar defects, differ slightly in their tetragonal structures, and exhibit different mosaicities and strain values. Therefore, Ce2RhIn8 approaches the paracrystalline state, rather than the classic crystalline state and thus several of the concepts of conventional single-crystal crystallography are inapplicable. The structural results are discussed in the context of the role of disorder in the heavy-fermion state and in the interplay between superconductivity and magnetism.

A comparison of GLAS SAT and NMC high resolution NOSAT forecasts from 19 and 11 February 1976

NASA Technical Reports Server (NTRS)

Atlas, R.

1979-01-01

A subjective comparison of the Goddard Laboratory for Atmospheric Sciences (GLAS) and the National Meteorological Center (NMC) high resolution model forecasts is presented. Two cases where NMC's operational model in 1976 had serious difficulties in forecasting for the United States were examined. For each of the cases, the GLAS model forecasts from initial conditions which included satellite sounding data were compared directly to the NMC higher resolution model forecasts, from initial conditions which excluded the satellite data. The comparison showed that the GLAS satellite forecasts significantly improved upon the current NMC operational model's predictions in both cases.

A seamless, high-resolution digital elevation model (DEM) of the north-central California coast

USGS Publications Warehouse

Foxgrover, Amy C.; Barnard, Patrick L.

2012-01-01

A seamless, 2-meter resolution digital elevation model (DEM) of the north-central California coast has been created from the most recent high-resolution bathymetric and topographic datasets available. The DEM extends approximately 150 kilometers along the California coastline, from Half Moon Bay north to Bodega Head. Coverage extends inland to an elevation of +20 meters and offshore to at least the 3 nautical mile limit of state waters. This report describes the procedures of DEM construction, details the input data sources, and provides the DEM for download in both ESRI Arc ASCII and GeoTIFF file formats with accompanying metadata.

Chemical speciation using high energy resolution PIXE spectroscopy in the tender X-ray range

NASA Astrophysics Data System (ADS)

Kavčič, Matjaž; Petric, Marko; Vogel-Mikuš, Katarina

2018-02-01

High energy resolution X-ray emission spectroscopy employing wavelength dispersive (WDS) crystal spectrometers can provide energy resolution on the level of core-hole lifetime broadening of the characteristic emission lines. While crystal spectrometers have been traditionally used in combination with electron excitation for major and minor element analysis, they have been rarely considered in proton induced X-ray emission (PIXE) trace element analysis mainly due to low detection efficiency. Compared to the simplest flat crystal WDS spectrometer the efficiency can be improved by employing cylindrically or even spherically curved crystals in combination with position sensitive X-ray detectors. When such spectrometer is coupled to MeV proton excitation, chemical bonding effects are revealed in the high energy resolution spectra yielding opportunity to extend the analytical capabilities of PIXE technique also towards chemical state analysis. In this contribution we will focus on the high energy resolution PIXE (HR-PIXE) spectroscopy in the tender X-ray range performed in our laboratory with our home-built tender X-ray emission spectrometer. Some general properties of high energy resolution PIXE spectroscopy in the tender X-ray range are presented followed by an example of sulfur speciation in biological tissue illustrating the capabilities as well as limitations of HR-PIXE method used for chemical speciation in the tender X-ray range.

The high resolution spectrum of 15NH3 in the far-infrared: Rotation-inversion transitions in the ground, v2=1, 2 and v4=1 states

NASA Astrophysics Data System (ADS)

Fusina, Luciano; Di Lonardo, Gianfranco; Canè, Elisabetta; Predoi-Cross, Adriana; Rozario, Hoimonti; Herman, Michel

2017-12-01

The high resolution spectrum of 15NH3 has been recorded at unapodized resolution of 0.00096 cm-1 in the region 60-600 cm-1 using the Bruker IFS 125 Fourier transform spectrometer located at the far-infrared beam-line, Canadian Light Source. We report on the observation and analysis of the rotation-inversion spectrum in the ground, v2=1, 2 and v4=1 states. All the rotation-inversion transitions in the ground state together with the pure inversion transitions present in the literature were fitted simultaneously on the basis of a rotation-inversion Hamiltonian which includes distortion constants up to the 12th power in the angular momentum and the Δk=±3 and Δk=±6 interaction terms. A set of effective parameters was also obtained for the v2=1 state adopting the same theoretical model. For the v2=2 and v4=1 states only a list of observed transitions is reported. The wavenumbers of all the assigned transitions were compared with their theoretically predicted values [S.N. Yurchenko, J. Quant. Spectrosc. Radiat. Transf., 2015, 152, 28]. The present results noticeably improve the wavenumber line list in the HITRAN data base [L. S. Rothman et al. J. Quant. Spectrosc. Radiat. Transf.,2013, 130, 4].

High resolution multidetector CT aided tissue analysis and quantification of lung fibrosis

NASA Astrophysics Data System (ADS)

Zavaletta, Vanessa A.; Karwoski, Ronald A.; Bartholmai, Brian; Robb, Richard A.

2006-03-01

Idiopathic pulmonary fibrosis (IPF, also known as Idiopathic Usual Interstitial Pneumontis, pathologically) is a progressive diffuse lung disease which has a median survival rate of less than four years with a prevalence of 15-20/100,000 in the United States. Global function changes are measured by pulmonary function tests and the diagnosis and extent of pulmonary structural changes are typically assessed by acquiring two-dimensional high resolution CT (HRCT) images. The acquisition and analysis of volumetric high resolution Multi-Detector CT (MDCT) images with nearly isotropic pixels offers the potential to measure both lung function and structure. This paper presents a new approach to three dimensional lung image analysis and classification of normal and abnormal structures in lungs with IPF.

Crystal structure of the GTPase domain and the bundle signalling element of dynamin in the GDP state

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anand, Roopsee; Eschenburg, Susanne; Reubold, Thomas F., E-mail: Reubold.Thomas@mh-hannover.de

Dynamin is the prototype of a family of large multi-domain GTPases. The 100 kDa protein is a key player in clathrin-mediated endocytosis, where it cleaves off vesicles from membranes using the energy from GTP hydrolysis. We have solved the high resolution crystal structure of a fusion protein of the GTPase domain and the bundle signalling element (BSE) of dynamin 1 liganded with GDP. The structure provides a hitherto missing snapshot of the GDP state of the hydrolytic cycle of dynamin and reveals how the switch I region moves away from the active site after GTP hydrolysis and release of inorganic phosphate.more » Comparing our structure of the GDP state with the known structures of the GTP state, the transition state and the nucleotide-free state of dynamin 1 we describe the structural changes through the hydrolytic cycle. - Highlights: • High resolution crystal structure of the GDP-state of a dynamin 1 GTPase-BSE fusion. • Visualizes one of the key states of the hydrolytic cycle of dynamin. • The dynamin-specific loop forms a helix as soon as a guanine base is present.« less

Exploring high-resolution magic angle spinning (HR-MAS) NMR spectroscopy for metabonomic analysis of apples.

PubMed

Vermathen, Martina; Marzorati, Mattia; Vermathen, Peter

2012-01-01

Classical liquid-state high-resolution (HR) NMR spectroscopy has proved a powerful tool in the metabonomic analysis of liquid food samples like fruit juices. In this paper the application of (1)H high-resolution magic angle spinning (HR-MAS) NMR spectroscopy to apple tissue is presented probing its potential for metabonomic studies. The (1)H HR-MAS NMR spectra are discussed in terms of the chemical composition of apple tissue and compared to liquid-state NMR spectra of apple juice. Differences indicate that specific metabolic changes are induced by juice preparation. The feasibility of HR-MAS NMR-based multivariate analysis is demonstrated by a study distinguishing three different apple cultivars by principal component analysis (PCA). Preliminary results are shown from subsequent studies comparing three different cultivation methods by means of PCA and partial least squares discriminant analysis (PLS-DA) of the HR-MAS NMR data. The compounds responsible for discriminating organically grown apples are discussed. Finally, an outlook of our ongoing work is given including a longitudinal study on apples.

A comprehensive pipeline for multi-resolution modeling of the mitral valve: Validation, computational efficiency, and predictive capability.

PubMed

Drach, Andrew; Khalighi, Amir H; Sacks, Michael S

2018-02-01

Multiple studies have demonstrated that the pathological geometries unique to each patient can affect the durability of mitral valve (MV) repairs. While computational modeling of the MV is a promising approach to improve the surgical outcomes, the complex MV geometry precludes use of simplified models. Moreover, the lack of complete in vivo geometric information presents significant challenges in the development of patient-specific computational models. There is thus a need to determine the level of detail necessary for predictive MV models. To address this issue, we have developed a novel pipeline for building attribute-rich computational models of MV with varying fidelity directly from the in vitro imaging data. The approach combines high-resolution geometric information from loaded and unloaded states to achieve a high level of anatomic detail, followed by mapping and parametric embedding of tissue attributes to build a high-resolution, attribute-rich computational models. Subsequent lower resolution models were then developed and evaluated by comparing the displacements and surface strains to those extracted from the imaging data. We then identified the critical levels of fidelity for building predictive MV models in the dilated and repaired states. We demonstrated that a model with a feature size of about 5 mm and mesh size of about 1 mm was sufficient to predict the overall MV shape, stress, and strain distributions with high accuracy. However, we also noted that more detailed models were found to be needed to simulate microstructural events. We conclude that the developed pipeline enables sufficiently complex models for biomechanical simulations of MV in normal, dilated, repaired states. Copyright © 2017 John Wiley & Sons, Ltd.

Satellite remote sensing of landscape freeze/thaw state dynamics for complex Topography and Fire Disturbance Areas Using multi-sensor radar and SRTM digital elevation models

NASA Technical Reports Server (NTRS)

Podest, Erika; McDonald, Kyle; Kimball, John; Randerson, James

2003-01-01

We characterize differences in radar-derived freeze/thaw state, examining transitions over complex terrain and landscape disturbance regimes. In areas of complex terrain, we explore freezekhaw dynamics related to elevation, slope aspect and varying landcover. In the burned regions, we explore the timing of seasonal freeze/thaw transition as related to the recovering landscape, relative to that of a nearby control site. We apply in situ biophysical measurements, including flux tower measurements to validate and interpret the remotely sensed parameters. A multi-scale analysis is performed relating high-resolution SAR backscatter and moderate resolution scatterometer measurements to assess trade-offs in spatial and temporal resolution in the remotely sensed fields.

A high-resolution thermoelectric module-based calorimeter for measuring the energetics of isolated ventricular trabeculae at body temperature.

PubMed

Johnston, Callum M; Han, June-Chiew; Ruddy, Bryan P; Nielsen, Poul M F; Taberner, Andrew J

2015-07-15

Isolated ventricular trabeculae are the most common experimental preparations used in the study of cardiac energetics. However, the experiments have been conducted at subphysiological temperatures. We have overcome this limitation by designing and constructing a novel calorimeter with sufficiently high thermal resolution for simultaneously measuring the heat output and force production of isolated, contracting, ventricular trabeculae at body temperature. This development was largely motivated by the need to better understand cardiac energetics by performing such measurements at body temperature to relate tissue performance to whole heart behavior in vivo. Our approach uses solid-state thermoelectric modules, tailored for both temperature sensing and temperature control. The thermoelectric modules have high sensitivity and low noise, which, when coupled with a multilevel temperature control system, enable an exceptionally high temperature resolution with a noise-equivalent power an order of magnitude greater than those of other existing muscle calorimeters. Our system allows us to rapidly and easily change the experimental temperature without disturbing the state of the muscle. Our calorimeter is useful in many experiments that explore the energetics of normal physiology as well as pathophysiology of cardiac muscle. Copyright © 2015 the American Physiological Society.

HIPS: A new hippocampus subfield segmentation method.

PubMed

Romero, José E; Coupé, Pierrick; Manjón, José V

2017-12-01

The importance of the hippocampus in the study of several neurodegenerative diseases such as Alzheimer's disease makes it a structure of great interest in neuroimaging. However, few segmentation methods have been proposed to measure its subfields due to its complex structure and the lack of high resolution magnetic resonance (MR) data. In this work, we present a new pipeline for automatic hippocampus subfield segmentation using two available hippocampus subfield delineation protocols that can work with both high and standard resolution data. The proposed method is based on multi-atlas label fusion technology that benefits from a novel multi-contrast patch match search process (using high resolution T1-weighted and T2-weighted images). The proposed method also includes as post-processing a new neural network-based error correction step to minimize systematic segmentation errors. The method has been evaluated on both high and standard resolution images and compared to other state-of-the-art methods showing better results in terms of accuracy and execution time. Copyright © 2017 Elsevier Inc. All rights reserved.

Wavelength scanning achieves pixel super-resolution in holographic on-chip microscopy

NASA Astrophysics Data System (ADS)

Luo, Wei; Göröcs, Zoltan; Zhang, Yibo; Feizi, Alborz; Greenbaum, Alon; Ozcan, Aydogan

2016-03-01

Lensfree holographic on-chip imaging is a potent solution for high-resolution and field-portable bright-field imaging over a wide field-of-view. Previous lensfree imaging approaches utilize a pixel super-resolution technique, which relies on sub-pixel lateral displacements between the lensfree diffraction patterns and the image sensor's pixel-array, to achieve sub-micron resolution under unit magnification using state-of-the-art CMOS imager chips, commonly used in e.g., mobile-phones. Here we report, for the first time, a wavelength scanning based pixel super-resolution technique in lensfree holographic imaging. We developed an iterative super-resolution algorithm, which generates high-resolution reconstructions of the specimen from low-resolution (i.e., under-sampled) diffraction patterns recorded at multiple wavelengths within a narrow spectral range (e.g., 10-30 nm). Compared with lateral shift-based pixel super-resolution, this wavelength scanning approach does not require any physical shifts in the imaging setup, and the resolution improvement is uniform in all directions across the sensor-array. Our wavelength scanning super-resolution approach can also be integrated with multi-height and/or multi-angle on-chip imaging techniques to obtain even higher resolution reconstructions. For example, using wavelength scanning together with multi-angle illumination, we achieved a halfpitch resolution of 250 nm, corresponding to a numerical aperture of 1. In addition to pixel super-resolution, the small scanning steps in wavelength also enable us to robustly unwrap phase, revealing the specimen's optical path length in our reconstructed images. We believe that this new wavelength scanning based pixel super-resolution approach can provide competitive microscopy solutions for high-resolution and field-portable imaging needs, potentially impacting tele-pathology applications in resource-limited-settings.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiswell, S

2009-01-11

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

High-Resolution, Low-Cost Spectrometer-on-Chip

DTIC Science & Technology

2015-01-02

extracted for each PhCs for λ=400 and 500 nm, respectively; d) example of the spectral response of our prototype to two input filtered lights. aBeam...packed into the size of a USB key. Nano-spectrometers with a resolution down to 0.5 nm and a spectral range up to 229 nm were successfully demonstrated...Our miniaturized spectrometers are defining the state-of-the-art for on-chip spectroscopy, as well as in terms of spectral resolution and bandwidth

Atomic-resolution 3D structure of amyloid β fibrils: The Osaka mutation

DOE PAGES

Schutz, Anne K.; Wall, Joseph; Vagt, Toni; ...

2014-11-13

Despite its central importance for understanding the molecular basis of Alzheimer's disease (AD), high-resolution structural information on amyloid β-peptide (Aβ) fibrils, which are intimately linked with AD, is scarce. We report an atomic-resolution fibril structure of the Aβ 1-40 peptide with the Osaka mutation (E22Δ), associated with early-onset AD. The structure, which differs substantially from all previously proposed models, is based on a large number of unambiguous intra- and intermolecular solid-state NMR distance restraints

Employing temporal self-similarity across the entire time domain in computed tomography reconstruction

PubMed Central

Kazantsev, D.; Van Eyndhoven, G.; Lionheart, W. R. B.; Withers, P. J.; Dobson, K. J.; McDonald, S. A.; Atwood, R.; Lee, P. D.

2015-01-01

There are many cases where one needs to limit the X-ray dose, or the number of projections, or both, for high frame rate (fast) imaging. Normally, it improves temporal resolution but reduces the spatial resolution of the reconstructed data. Fortunately, the redundancy of information in the temporal domain can be employed to improve spatial resolution. In this paper, we propose a novel regularizer for iterative reconstruction of time-lapse computed tomography. The non-local penalty term is driven by the available prior information and employs all available temporal data to improve the spatial resolution of each individual time frame. A high-resolution prior image from the same or a different imaging modality is used to enhance edges which remain stationary throughout the acquisition time while dynamic features tend to be regularized spatially. Effective computational performance together with robust improvement in spatial and temporal resolution makes the proposed method a competitive tool to state-of-the-art techniques. PMID:25939621

Resolving shocked and UV excited components of H2 emission in planetary nebulae with high-resolution near-infrared spectroscopy

NASA Astrophysics Data System (ADS)

Kaplan, Kyle; Dinerstein, Harriet L.; Jaffe, Daniel Thomas

2016-06-01

Planetary nebulae (PNe) form when low and intermediate-mass stars eject their outer layers into the ISM at the end of the AGB phase. Many PNe exhibit near-infrared (NIR) emission from molecular hydrogen (H2). This NIR emission arises from radiative decay out of excited rotation-vibration (rovibrational) states. The rovibrational states can be populated by excitation to higher electronic states through absorption of a far-UV photon followed by a radiative cascade to the electronic ground state, or by collisions (e.g., in a hot gas). The two processes populate the rovibrational levels of H2 differently, so the observed emergent emission spectrum provides an effective probe of the mechanisms that excite the H2. Many PNe display line intensity ratios that are intermediate between these two processes (Otsuka et al. 2013). With the advantages of the high spectral resolution (R~40000), broad wavelength coverage (1.45-2.45 μm), and high spatial resolution of the Immersion GRating Infrared Spectrometer (IGRINS, Park et al. 2014), we are able to differentiate components in position-velocity space: we see a slowly expanding UV-excited H2 shell in the PN M 1-11 and two faster moving “bullets” of thermalized H2 that we interpret as shocked gas from a bipolar outflow. We also present observations of several other PNe that exhibit similar morphologies of thermalized and UV-excited H2 components.

AN AMMONIA EMISSION INVENTORY FOR FERTILIZER APPLICATION IN THE UNITED STATES. (R826371C006)

EPA Science Inventory

Fertilizer application represents a significant fraction of ammonia emissions from all sources in the United States. Previously published ammonia inventories have generally suffered from poor spatial and temporal resolution, erroneous activity levels, and highly uncertain emis...

Resolution analysis of archive films for the purpose of their optimal digitization and distribution

NASA Astrophysics Data System (ADS)

Fliegel, Karel; Vítek, Stanislav; Páta, Petr; Myslík, Jiří; Pecák, Josef; Jícha, Marek

2017-09-01

With recent high demand for ultra-high-definition (UHD) content to be screened in high-end digital movie theaters but also in the home environment, film archives full of movies in high-definition and above are in the scope of UHD content providers. Movies captured with the traditional film technology represent a virtually unlimited source of UHD content. The goal to maintain complete image information is also related to the choice of scanning resolution and spatial resolution for further distribution. It might seem that scanning the film material in the highest possible resolution using state-of-the-art film scanners and also its distribution in this resolution is the right choice. The information content of the digitized images is however limited, and various degradations moreover lead to its further reduction. Digital distribution of the content in the highest image resolution might be therefore unnecessary or uneconomical. In other cases, the highest possible resolution is inevitable if we want to preserve fine scene details or film grain structure for archiving purposes. This paper deals with the image detail content analysis of archive film records. The resolution limit in captured scene image and factors which lower the final resolution are discussed. Methods are proposed to determine the spatial details of the film picture based on the analysis of its digitized image data. These procedures allow determining recommendations for optimal distribution of digitized video content intended for various display devices with lower resolutions. Obtained results are illustrated on spatial downsampling use case scenario, and performance evaluation of the proposed techniques is presented.

A High Angular Resolution Survey of Massive Stars in Cygnus OB2: Results from the Hubble Space Telescope Fine Guidance Sensors

DTIC Science & Technology

2014-02-01

F. J. Moffat9, and N. R. Walborn2 1 Center for High Angular Resolution Astronomy, Department of Physics and Astronomy, Georgia State University, P.O...Martin Drive, Baltimore, MD 21218, USA; nelan@stsci.edu, walborn@stsci.edu 3 Department of Natural Sciences, University of South Carolina Beaufort, 1 ...Online-only material: figure set 1 . INTRODUCTION Massive stars (10M) play a fundamental role in the evo- lution of the universe, from influencing

High-resolution imaging and target designation through clouds or smoke

DOEpatents

Perry, Michael D.

2003-01-01

A method and system of combining gated intensifiers and advances in solid-state, short-pulse laser technology, compact systems capable of producing high resolution (i.e., approximately less than 20 centimeters) optical images through a scattering medium such as dense clouds, fog, smoke, etc. may be achieved from air or ground based platforms. Laser target designation through a scattering medium is also enabled by utilizing a short pulse illumination laser and a relatively minor change to the detectors on laser guided munitions.

High temporal-resolution view of transcription and chromatin states across distinct metabolic states in budding yeast

PubMed Central

Kuang, Zheng; Cai, Ling; Zhang, Xuekui; Ji, Hongkai; Tu, Benjamin P.; Boeke, Jef D.

2014-01-01

Under continuous, glucose-limited conditions, budding yeast exhibit robust metabolic cycles associated with major oscillations of gene expression. How such fluctuations are linked to changes in chromatin status is not well understood. Here we examine the correlated genome-wide transcription and chromatin states across the yeast metabolic cycle at unprecedented temporal resolution, revealing a “just-in-time supply chain” by which components from specific cellular processes such as ribosome biogenesis become available in a highly coordinated manner. We identify distinct chromatin and splicing patterns associated with different gene categories and determine the relative timing of chromatin modifications to maximal transcription. There is unexpected variation in the chromatin modification and expression relationship, with histone acetylation peaks occurring with varying timing and “sharpness” relative to RNA expression both within and between cycle phases. Chromatin modifier occupancy reveals subtly distinct spatial and temporal patterns compared to the modifications themselves. PMID:25173176

Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations.

PubMed

Ferreira da Silva, F; Lange, E; Limão-Vieira, P; Jones, N C; Hoffmann, S V; Hubin-Franskin, M-J; Delwiche, J; Brunger, M J; Neves, R F C; Lopes, M C A; de Oliveira, E M; da Costa, R F; Varella, M T do N; Bettega, M H F; Blanco, F; García, G; Lima, M A P; Jones, D B

2015-10-14

The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5-10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range.

Electronic excitation of furfural as probed by high-resolution vacuum ultraviolet spectroscopy, electron energy loss spectroscopy, and ab initio calculations

NASA Astrophysics Data System (ADS)

Ferreira da Silva, F.; Lange, E.; Limão-Vieira, P.; Jones, N. C.; Hoffmann, S. V.; Hubin-Franskin, M.-J.; Delwiche, J.; Brunger, M. J.; Neves, R. F. C.; Lopes, M. C. A.; de Oliveira, E. M.; da Costa, R. F.; Varella, M. T. do N.; Bettega, M. H. F.; Blanco, F.; García, G.; Lima, M. A. P.; Jones, D. B.

2015-10-01

The electronic spectroscopy of isolated furfural (2-furaldehyde) in the gas phase has been investigated using high-resolution photoabsorption spectroscopy in the 3.5-10.8 eV energy-range, with absolute cross section measurements derived. Electron energy loss spectra are also measured over a range of kinematical conditions. Those energy loss spectra are used to derive differential cross sections and in turn generalised oscillator strengths. These experiments are supported by ab initio calculations in order to assign the excited states of the neutral molecule. The good agreement between the theoretical results and the measurements allows us to provide the first quantitative assignment of the electronic state spectroscopy of furfural over an extended energy range.

Identification of the iron oxidation state and coordination geometry in iron oxide- and zeolite-based catalysts using pre-edge XAS analysis.

PubMed

Boubnov, Alexey; Lichtenberg, Henning; Mangold, Stefan; Grunwaldt, Jan Dierk

2015-03-01

Analysis of the oxidation state and coordination geometry using pre-edge analysis is attractive for heterogeneous catalysis and materials science, especially for in situ and time-resolved studies or highly diluted systems. In the present study, focus is laid on iron-based catalysts. First a systematic investigation of the pre-edge region of the Fe K-edge using staurolite, FePO4, FeO and α-Fe2O3 as reference compounds for tetrahedral Fe(2+), tetrahedral Fe(3+), octahedral Fe(2+) and octahedral Fe(3+), respectively, is reported. In particular, high-resolution and conventional X-ray absorption spectra are compared, considering that in heterogeneous catalysis and material science a compromise between high-quality spectroscopic data acquisition and simultaneous analysis of functional properties is required. Results, which were obtained from reference spectra acquired with different resolution and quality, demonstrate that this analysis is also applicable to conventionally recorded pre-edge data. For this purpose, subtraction of the edge onset is preferentially carried out using an arctangent and a first-degree polynomial, independent of the resolution and quality of the data. For both standard and high-resolution data, multiplet analysis of pre-edge features has limitations due to weak transitions that cannot be identified. On the other hand, an arbitrary empirical peak fitting assists the analysis in that non-local transitions can be isolated. The analysis of the oxidation state and coordination geometry of the Fe sites using a variogram-based method is shown to be effective for standard-resolution data and leads to the same results as for high-resolution spectra. This method, validated by analysing spectra of reference compounds and their well defined mixtures, is finally applied to track structural changes in a 1% Fe/Al2O3 and a 0.5% Fe/BEA zeolite catalyst during reduction in 5% H2/He. The results, hardly accessible by other techniques, show that Fe(3+) is transformed into Fe(2+), while the local Fe-O coordination number of 4-5 is maintained, suggesting that the reduction involves a rearrangement of the oxygen neighbours rather than their removal. In conclusion, the variogram-based analysis of Fe K-edge spectra proves to be very useful in catalysis research.

Assignment of the photoelectron spectrum of the nitrate anion NO3- and vibronic interactions in the nitrate free radical

NASA Astrophysics Data System (ADS)

Hirota, Eizi

2018-01-01

The unpaired electron orbital of NO3 is of a2‧ symmetry in the ground electronic state, and thus its motion about the symmetry axis of the molecule is free rotation. When a degenerate vibration is excited, however, the free azimuthal rotation of the unpaired electron is perturbed much by nuclear motions of the degenerate mode, as evidenced by high-resolution spectroscopic studies. Thus the ν4 fundamental state, for example, bears some characters of the B ˜ excited electronic state through the Herzberg-Teller (H-T) interaction, and Neumark et al. explained anomalous ν4 progression in the photoelectron spectra of the NO3- anion by the H-T mechanism. However, the interaction parameter Neumark required was too large to reproduce the ν4 molecular parameters in the ground electronic state precisely determined by high-resolution IR spectroscopy. This discrepancy was resolved by the fact that the upper ν4 overtone/combination states of Neumark's photoelectron transitions were primarily of vibrational in nature. The present study thus showed that NO3 bears both vibrational and H-T induced electronic characters in excited states of degenerate modes in the ground electronic state.

Very high resolution far infrared synchrotron radiation spectrum of methanol-D1 (CH2DOH) in the first three torsional-vibrational modes

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Indra; Billinghurst, B. E.

2016-11-01

In our effort to systematically study the far infrared (FIR) spectra of asymmetrically mono deuterated methanol (CH2DOH) and thereby obtain the transition wavenumbers with better and better accuracy (Mukhopadhyay, 2016a,b), the complete Fourier transform (FT) spectra from FIR to infrared (IR) vibrational bands (in the range 50-1190 cm-1) have been re-recorded using the Synchrotron Radiation Source at the Canadian Light Sources in Saskatchewan, Canada. The resolution of the spectrum is unprecedented, reaching beyond the Doppler limited resolution as low as about 0.0008 cm-1 with a signal to noise (S/N) ratio is many fold better than that can be obtained by commercially available FT spectrometer using thermal sources (e.g., Globar). Spectra were also recorded beyond 1190 cm-1 to about 5000 cm-1 at a somewhat lower resolution of 0.002-0.004 cm-1. In this report the analysis of the b-type and c-type torsional - rotational spectra in the ground vibrational state corresponding to gauche- (e1/o1) to gauche- (e1/o1) and gauche- (e1/o1) to trans- (e0) states in the ground vibrational state are reported and an atlas of the wavenumber for about 2500 FIR assigned absorption lines has been prepared. The transitions within a given sub-band are analyzed using state dependent expansion parameters and the Q-branch origins. The data from previous results (Mukhopadhyay, 2016a,b) along with the present work allowed a global analysis yielding a complete set of molecular parameters. The state dependent molecular parameters reproduce the experimental wavenumbers within experimental uncertainty. In addition, the sensitivity of the spectrum allowed observation of forbidden transitions previously unobserved and helped reassignment of rotational angular momentum quantum numbers of some ΔK = ±1, Q-branch transitions in highly excited states recently reported in the literature. To our knowledge the wavenumbers reported in the present work are the most accurate so far reported in the literature and represent the highest resolution spectra for this molecular species.

Ultrahigh-resolution imaging of the human brain with phase-cycled balanced steady-state free precession at 7 T.

PubMed

Zeineh, Michael M; Parekh, Mansi B; Zaharchuk, Greg; Su, Jason H; Rosenberg, Jarrett; Fischbein, Nancy J; Rutt, Brian K

2014-05-01

The objectives of this study were to acquire ultra-high resolution images of the brain using balanced steady-state free precession (bSSFP) at 7 T and to identify the potential utility of this sequence. Eight volunteers participated in this study after providing informed consent. Each volunteer was scanned with 8 phase cycles of bSSFP at 0.4-mm isotropic resolution using 0.5 number of excitations and 2-dimensional parallel acceleration of 1.75 × 1.75. Each phase cycle required 5 minutes of scanning, with pauses between the phase cycles allowing short periods of rest. The individual phase cycles were aligned and then averaged. The same volunteers underwent scanning using 3-dimensional (3D) multiecho gradient recalled echo at 0.8-mm isotropic resolution, 3D Cube T2 at 0.7-mm isotropic resolution, and thin-section coronal oblique T2-weighted fast spin echo at 0.22 × 0.22 × 2.0-mm resolution for comparison. Two neuroradiologists assessed image quality and potential research and clinical utility. The volunteers generally tolerated the scan sessions well, and composite high-resolution bSSFP images were produced for each volunteer. Rater analysis demonstrated that bSSFP had a superior 3D visualization of the microarchitecture of the hippocampus, very good contrast to delineate the borders of the subthalamic nucleus, and relatively good B1 homogeneity throughout. In addition to an excellent visualization of the cerebellum, subtle details of the brain and skull base anatomy were also easier to identify on the bSSFP images, including the line of Gennari, membrane of Liliequist, and cranial nerves. Balanced steady-state free precession had a strong iron contrast similar to or better than the comparison sequences. However, cortical gray-white contrast was significantly better with Cube T2 and T2-weighted fast spin echo. Balanced steady-state free precession can facilitate ultrahigh-resolution imaging of the brain. Although total imaging times are long, the individually short phase cycles can be acquired separately, improving examination tolerability. These images may be beneficial for studies of the hippocampus, iron-containing structures such as the subthalamic nucleus and line of Gennari, and the basal cisterns and their contents.

Assessment of summer rainfall forecast skill in the Intra-Americas in GFDL high and low-resolution models

NASA Astrophysics Data System (ADS)

Krishnamurthy, Lakshmi; Muñoz, Ángel G.; Vecchi, Gabriel A.; Msadek, Rym; Wittenberg, Andrew T.; Stern, Bill; Gudgel, Rich; Zeng, Fanrong

2018-05-01

The Caribbean low-level jet (CLLJ) is an important component of the atmospheric circulation over the Intra-Americas Sea (IAS) which impacts the weather and climate both locally and remotely. It influences the rainfall variability in the Caribbean, Central America, northern South America, the tropical Pacific and the continental Unites States through the transport of moisture. We make use of high-resolution coupled and uncoupled models from the Geophysical Fluid Dynamics Laboratory (GFDL) to investigate the simulation of the CLLJ and its teleconnections and further compare with low-resolution models. The high-resolution coupled model FLOR shows improvements in the simulation of the CLLJ and its teleconnections with rainfall and SST over the IAS compared to the low-resolution coupled model CM2.1. The CLLJ is better represented in uncoupled models (AM2.1 and AM2.5) forced with observed sea-surface temperatures (SSTs), emphasizing the role of SSTs in the simulation of the CLLJ. Further, we determine the forecast skill for observed rainfall using both high- and low-resolution predictions of rainfall and SSTs for the July-August-September season. We determine the role of statistical correction of model biases, coupling and horizontal resolution on the forecast skill. Statistical correction dramatically improves area-averaged forecast skill. But the analysis of spatial distribution in skill indicates that the improvement in skill after statistical correction is region dependent. Forecast skill is sensitive to coupling in parts of the Caribbean, Central and northern South America, and it is mostly insensitive over North America. Comparison of forecast skill between high and low-resolution coupled models does not show any dramatic difference. However, uncoupled models show improvement in the area-averaged skill in the high-resolution atmospheric model compared to lower resolution model. Understanding and improving the forecast skill over the IAS has important implications for highly vulnerable nations in the region.

Towards high-resolution laser ionization spectroscopy of the heaviest elements in supersonic gas jet expansion

PubMed Central

Ferrer, R.; Barzakh, A.; Bastin, B.; Beerwerth, R.; Block, M.; Creemers, P.; Grawe, H.; de Groote, R.; Delahaye, P.; Fléchard, X.; Franchoo, S.; Fritzsche, S.; Gaffney, L. P.; Ghys, L.; Gins, W.; Granados, C.; Heinke, R.; Hijazi, L.; Huyse, M.; Kron, T.; Kudryavtsev, Yu.; Laatiaoui, M.; Lecesne, N.; Loiselet, M.; Lutton, F.; Moore, I. D.; Martínez, Y.; Mogilevskiy, E.; Naubereit, P.; Piot, J.; Raeder, S.; Rothe, S.; Savajols, H.; Sels, S.; Sonnenschein, V.; Thomas, J-C; Traykov, E.; Van Beveren, C.; Van den Bergh, P.; Van Duppen, P.; Wendt, K.; Zadvornaya, A.

2017-01-01

Resonant laser ionization and spectroscopy are widely used techniques at radioactive ion beam facilities to produce pure beams of exotic nuclei and measure the shape, size, spin and electromagnetic multipole moments of these nuclei. However, in such measurements it is difficult to combine a high efficiency with a high spectral resolution. Here we demonstrate the on-line application of atomic laser ionization spectroscopy in a supersonic gas jet, a technique suited for high-precision studies of the ground- and isomeric-state properties of nuclei located at the extremes of stability. The technique is characterized in a measurement on actinium isotopes around the N=126 neutron shell closure. A significant improvement in the spectral resolution by more than one order of magnitude is achieved in these experiments without loss in efficiency. PMID:28224987

Open Science CBS Neuroimaging Repository: Sharing ultra-high-field MR images of the brain.

PubMed

Tardif, Christine Lucas; Schäfer, Andreas; Trampel, Robert; Villringer, Arno; Turner, Robert; Bazin, Pierre-Louis

2016-01-01

Magnetic resonance imaging at ultra high field opens the door to quantitative brain imaging at sub-millimeter isotropic resolutions. However, novel image processing tools to analyze these new rich datasets are lacking. In this article, we introduce the Open Science CBS Neuroimaging Repository: a unique repository of high-resolution and quantitative images acquired at 7 T. The motivation for this project is to increase interest for high-resolution and quantitative imaging and stimulate the development of image processing tools developed specifically for high-field data. Our growing repository currently includes datasets from MP2RAGE and multi-echo FLASH sequences from 28 and 20 healthy subjects respectively. These datasets represent the current state-of-the-art in in-vivo relaxometry at 7 T, and are now fully available to the entire neuroimaging community. Copyright © 2015 Elsevier Inc. All rights reserved.

Determination of accurate 1H positions of an alanine tripeptide with anti-parallel and parallel β-sheet structures by high resolution 1H solid state NMR and GIPAW chemical shift calculation.

PubMed

Yazawa, Koji; Suzuki, Furitsu; Nishiyama, Yusuke; Ohata, Takuya; Aoki, Akihiro; Nishimura, Katsuyuki; Kaji, Hironori; Shimizu, Tadashi; Asakura, Tetsuo

2012-11-25

The accurate (1)H positions of alanine tripeptide, A(3), with anti-parallel and parallel β-sheet structures could be determined by highly resolved (1)H DQMAS solid-state NMR spectra and (1)H chemical shift calculation with gauge-including projector augmented wave calculations.

The Feasibility of Publicly Funded Residential Education in Pennsylvania. Staff Analysis Pursuant to House Resolution 43 of 1995.

ERIC Educational Resources Information Center

Pennsylvania Joint State Government Commission, Harrisburg.

Pennsylvania's House Resolution 43 of 1995 directs the Joint State Government Commission to report to the General Assembly on the feasibility of creating a voluntary residential school program for disadvantaged children. The Commission assembled a Working Group to consider this issue, and the group focused on poor children living in high crime…

Enhancing Conservation with High Resolution Productivity Datasets for the Conterminous United States

NASA Astrophysics Data System (ADS)

Robinson, Nathaniel Paul

Human driven alteration of the earth's terrestrial surface is accelerating through land use changes, intensification of human activity, climate change, and other anthropogenic pressures. These changes occur at broad spatio-temporal scales, challenging our ability to effectively monitor and assess the impacts and subsequent conservation strategies. While satellite remote sensing (SRS) products enable monitoring of the earth's terrestrial surface continuously across space and time, the practical applications for conservation and management of these products are limited. Often the processes driving ecological change occur at fine spatial resolutions and are undetectable given the resolution of available datasets. Additionally, the links between SRS data and ecologically meaningful metrics are weak. Recent advances in cloud computing technology along with the growing record of high resolution SRS data enable the development of SRS products that quantify ecologically meaningful variables at relevant scales applicable for conservation and management. The focus of my dissertation is to improve the applicability of terrestrial gross and net primary productivity (GPP/NPP) datasets for the conterminous United States (CONUS). In chapter one, I develop a framework for creating high resolution datasets of vegetation dynamics. I use the entire archive of Landsat 5, 7, and 8 surface reflectance data and a novel gap filling approach to create spatially continuous 30 m, 16-day composites of the normalized difference vegetation index (NDVI) from 1986 to 2016. In chapter two, I integrate this with other high resolution datasets and the MOD17 algorithm to create the first high resolution GPP and NPP datasets for CONUS. I demonstrate the applicability of these products for conservation and management, showing the improvements beyond currently available products. In chapter three, I utilize this dataset to evaluate the relationships between land ownership and terrestrial production across the CONUS domain. The main results of this work are three publicly available datasets: 1) 30 m Landsat NDVI; 2) 250 m MODIS based GPP and NPP; and 3) 30 m Landsat based GPP and NPP. My goal is that these products prove useful for the wider scientific, conservation, and land management communities as we continue to strive for better conservation and management practices.

Spectroscopic Characterisation of CARMENES Target Candidates from FEROS, CAFE and HRS High-Resolution Spectra

NASA Astrophysics Data System (ADS)

Passegger, Vera Maria; Reiners, Ansgar; Jeffers, Sandra V.; Wende, Sebastian; Schöfer, Patrick; Amado, Pedro J.; Caballero, Jose A.; Montes, David; Mundt, Reinhard; Ribas, Ignasi; Quirrenbach, Andreas

2016-07-01

CARMENES (Calar Alto high-Resolution search for M dwarfs with Exoearths with Near-infrared and optical Échelle Spectrographs) started a new planet survey on M-dwarfs in January this year. The new high-resolution spectrographs are operating in the visible and near-infrared at Calar Alto Observatory. They will perform high-accuracy radial-velocity measurements (goal 1 m s-1) of about 300 M-dwarfs with the aim to detect low-mass planets within habitable zones. We characterised the candidate sample for CARMENES and provide fundamental parameters for these stars in order to constrain planetary properties and understand star-planet systems. Using state-of-the-art model atmospheres (PHOENIX-ACES) and χ2-minimization with a downhill-simplex method we determine effective temperature, surface gravity and metallicity [Fe/H] for high-resolution spectra of around 480 stars of spectral types M0.0-6.5V taken with FEROS, CAFE and HRS. We find good agreement between the models and our observed high-resolution spectra. We show the performance of the algorithm, as well as results, parameter and spectral type distributions for the CARMENES candidate sample, which is used to define the CARMENES target sample. We also present first preliminary results obtained from CARMENES spectra.

Diversity of ecological communities of the United States

Treesearch

J.D. Wickham; T.G. Wade; K.B. Jones; Kurt H. Riitters; R.V. O' Neill

1995-01-01

Biodiversity, although recognized as encompassing several levels of biological organization, is often thought of as species diversity. Three diversity estimates were calculated for the conterminous United States using satellite data acquired from the Advanced Very High Resolution Radiometer (AVHRR): land cover richness, vegetation richness, and vegetation clustering....

A new synoptic scale resolving global climate simulation using the Community Earth System Model

NASA Astrophysics Data System (ADS)

Small, R. Justin; Bacmeister, Julio; Bailey, David; Baker, Allison; Bishop, Stuart; Bryan, Frank; Caron, Julie; Dennis, John; Gent, Peter; Hsu, Hsiao-ming; Jochum, Markus; Lawrence, David; Muñoz, Ernesto; diNezio, Pedro; Scheitlin, Tim; Tomas, Robert; Tribbia, Joseph; Tseng, Yu-heng; Vertenstein, Mariana

2014-12-01

High-resolution global climate modeling holds the promise of capturing planetary-scale climate modes and small-scale (regional and sometimes extreme) features simultaneously, including their mutual interaction. This paper discusses a new state-of-the-art high-resolution Community Earth System Model (CESM) simulation that was performed with these goals in mind. The atmospheric component was at 0.25° grid spacing, and ocean component at 0.1°. One hundred years of "present-day" simulation were completed. Major results were that annual mean sea surface temperature (SST) in the equatorial Pacific and El-Niño Southern Oscillation variability were well simulated compared to standard resolution models. Tropical and southern Atlantic SST also had much reduced bias compared to previous versions of the model. In addition, the high resolution of the model enabled small-scale features of the climate system to be represented, such as air-sea interaction over ocean frontal zones, mesoscale systems generated by the Rockies, and Tropical Cyclones. Associated single component runs and standard resolution coupled runs are used to help attribute the strengths and weaknesses of the fully coupled run. The high-resolution run employed 23,404 cores, costing 250 thousand processor-hours per simulated year and made about two simulated years per day on the NCAR-Wyoming supercomputer "Yellowstone."

High spatial resolution compressed sensing (HSPARSE) functional MRI.

PubMed

Fang, Zhongnan; Van Le, Nguyen; Choy, ManKin; Lee, Jin Hyung

2016-08-01

To propose a novel compressed sensing (CS) high spatial resolution functional MRI (fMRI) method and demonstrate the advantages and limitations of using CS for high spatial resolution fMRI. A randomly undersampled variable density spiral trajectory enabling an acceleration factor of 5.3 was designed with a balanced steady state free precession sequence to achieve high spatial resolution data acquisition. A modified k-t SPARSE method was then implemented and applied with a strategy to optimize regularization parameters for consistent, high quality CS reconstruction. The proposed method improves spatial resolution by six-fold with 12 to 47% contrast-to-noise ratio (CNR), 33 to 117% F-value improvement and maintains the same temporal resolution. It also achieves high sensitivity of 69 to 99% compared the original ground-truth, small false positive rate of less than 0.05 and low hemodynamic response function distortion across a wide range of CNRs. The proposed method is robust to physiological noise and enables detection of layer-specific activities in vivo, which cannot be resolved using the highest spatial resolution Nyquist acquisition. The proposed method enables high spatial resolution fMRI that can resolve layer-specific brain activity and demonstrates the significant improvement that CS can bring to high spatial resolution fMRI. Magn Reson Med 76:440-455, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.

Design studies of large aperture, high-resolution Earth science microwave radiometers compatible with small launch vehicles

NASA Technical Reports Server (NTRS)

Schroeder, Lyle C.; Bailey, M. C.; Harrington, Richard F.; Kendall, Bruce M.; Campbell, Thomas G.

1994-01-01

High-spatial-resolution microwave radiometer sensing from space with reasonable swath widths and revisit times favors large aperture systems. However, with traditional precision antenna design, the size and weight requirements for such systems are in conflict with the need to emphasize small launch vehicles. This paper describes tradeoffs between the science requirements, basic operational parameters, and expected sensor performance for selected satellite radiometer concepts utilizing novel lightweight compactly packaged real apertures. Antenna, feed, and radiometer subsystem design and calibration are presented. Preliminary results show that novel lightweight real aperture coupled with state-of-the-art radiometer designs are compatible with small launch systems, and hold promise for high-resolution earth science measurements of sea ice, precipitation, soil moisture, sea surface temperature, and ocean wind speeds.

The CHARA optical array

NASA Astrophysics Data System (ADS)

McAlister, Harold A.

1992-11-01

The Center for High Angular Resolution Astronomy (CHARA) was established in the College of Arts and Sciences at Georgia State University in 1984 with the goals of designing, constructing, and then operating a facility for very high spatial resolution astronomy. The interest in such a facility grew out of the participants' decade of activity in speckle interferometry. Although speckle interferometry continues to provide important astrophysical measurements of a variety of objects, many pressing problems require resolution far beyond that which can be expected from single aperture telescopes. In early 1986, CHARA received a grant from the National Science Foundation which has permitted a detailed exploration of the feasibility of constructing a facility which will provide a hundred-fold increase in angular resolution over what is possible by speckle interferometry at the largest existing telescopes. The design concept for the CHARA Array was developed initially with the contractural collaboration of United Technologies Optical Systems, Inc., in West Palm Beach, Florida, an arrangement that expired in August 1987. In late November 1987, the Georgia Tech Research Institute joined with CHARA to continue and complete the design concept study. Very high-resolution imaging at optical wavelengths is clearly coming of age in astronomy. The CHARA Array and other related projects will be important and necessary milestones along the way toward the development of a major national facility for high-resolution imaging--a true optical counterpart to the Very Large Array. Ground-based arrays and their scientific output will lead to high resolution facilities in space and, ultimately, on the Moon.

AMM15: a new high-resolution NEMO configuration for operational simulation of the European north-west shelf

NASA Astrophysics Data System (ADS)

Graham, Jennifer A.; O'Dea, Enda; Holt, Jason; Polton, Jeff; Hewitt, Helene T.; Furner, Rachel; Guihou, Karen; Brereton, Ashley; Arnold, Alex; Wakelin, Sarah; Castillo Sanchez, Juan Manuel; Mayorga Adame, C. Gabriela

2018-02-01

This paper describes the next-generation ocean forecast model for the European north-west shelf, which will become the basis of operational forecasts in 2018. This new system will provide a step change in resolution and therefore our ability to represent small-scale processes. The new model has a resolution of 1.5 km compared with a grid spacing of 7 km in the current operational system. AMM15 (Atlantic Margin Model, 1.5 km) is introduced as a new regional configuration of NEMO v3.6. Here we describe the technical details behind this configuration, with modifications appropriate for the new high-resolution domain. Results from a 30-year non-assimilative run using the AMM15 domain demonstrate the ability of this model to represent the mean state and variability of the region.

Overall, there is an improvement in the representation of the mean state across the region, suggesting similar improvements may be seen in the future operational system. However, the reduction in seasonal bias is greater off-shelf than on-shelf. In the North Sea, biases are largely unchanged. Since there has been no change to the vertical resolution or parameterization schemes, performance improvements are not expected in regions where stratification is dominated by vertical processes rather than advection. This highlights the fact that increased horizontal resolution will not lead to domain-wide improvements. Further work is needed to target bias reduction across the north-west shelf region.

Determination of 2,3,7,8-chlorine-substituted dibenzo-p-dioxins and -furans at the part per trillion level in United States beef fat using high-resolution gas chromatography/high-resolution mass spectrometry

NASA Technical Reports Server (NTRS)

Ferrario, J.; Byrne, C.; McDaniel, D.; Dupuy, A. Jr; Harless, R.

1996-01-01

As part of the U.S. EPA Dioxin Reassessment Program, the 2,3,7,8-chlorine-substituted dibenzo-p-dioxins and furans were measured at part per trillion (ppt) levels in beef fat collected from slaughter facilities in the United States. This is the first statistically designed national survey of these compounds in the U.S. beef supply. Analyte concentrations were determined by high-resolution gas chromatography/high-resolution mass spectrometry, using isotope dilution methodology. Method limits of detection on a whole weight basis were 0.05 ppt for TCDD and 0.10 ppt for TCDF, 0.50 ppt for the pentas (PeCDDs/PeCDFs)/hexas (HxCDDs/HxCDFs)/heptas (HpCDDs/HpCDFs), and 3.00 ppt for the octas (OCDD/OCDF). Method detection and quantitation limits were established on the basis of demonstrated performance criteria utilizing fortified samples rather than by conventional signal-to-noise or variability of response methods. The background subtraction procedures developed for this study minimized the likelihood of false positives and increased the confidence associated with reported values near the detection limits. Mean and median values for each of the 2,3,7,8-Cl-substituted dioxins and furans are reported, along with the supporting information required for their interpretation. The mean toxic equivalence values for the samples are 0.35 ppt (nondetects = 0) and 0.89 ppt (nondetects = 1/2 LOD).

Frequency analysis of the visual steady-state response measured with the fast optical signal in younger and older adults.

PubMed

Tse, Chun-Yu; Gordon, Brian A; Fabiani, Monica; Gratton, Gabriele

2010-09-01

Relatively high frequency activity (>4Hz) carries important information about the state of the brain or its response to high frequency events. The electroencephalogram (EEG) is commonly used to study these changes because it possesses high temporal resolution and a good signal-to-noise ratio. However, it provides limited spatial information. Non-invasive fast optical signals (FOS) have been proposed as a neuroimaging tool combining spatial and temporal resolution. Yet, this technique has not been applied to study high frequency brain oscillations because of its relatively low signal-to-noise ratio. Here we investigate the sensitivity of FOS to relatively high-frequency brain oscillations. We measured the steady-state optical response elicited in medial and lateral occipital cortex by checkerboard reversals occurring at 4, 6, and 8Hz in younger and older adults. Stimulus-dependent oscillations were observed at the predicted stimulation frequency. In addition, in the younger adults the FOS steady-state response was smaller in lateral than medial areas, whereas in the older adults it was reversed in these two cortical regions. This may reflect diminished top-down inhibitory control in the older adults. The results indicate that FOS can be used to study the modulation of relatively high-frequency brain oscillations in adjacent cortical regions. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Up Close and Personal

NASA Image and Video Library

2014-05-08

This image is one of the highest-resolution MDIS observations to date! Many craters of varying degradation states are visible, as well as gentle terrain undulations. Very short exposure times are needed to make these low-altitude observations while the spacecraft is moving quickly over the surface; thus the images are slightly noisier than typical MDIS images. This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury's surface at resolutions much higher than the 200-meter/pixel morphology base map. It is not possible to cover all of Mercury's surface at this high resolution, but typically several areas of high scientific interest are imaged in this mode each week. Date acquired: March 15, 2014 Image Mission Elapsed Time (MET): 37173522 Image ID: 5936740 Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS) Center Latitude: 71.91° Center Longitude: 232.7° E Resolution: 5 meters/pixel Scale: The image is approximately 8.3 km (5.2 mi.) across. Incidence Angle: 79.4° Emission Angle: 4.0° Phase Angle: 83.4° http://photojournal.jpl.nasa.gov/catalog/PIA18370

Soil Erosion map of Europe based on high resolution input datasets

NASA Astrophysics Data System (ADS)

Panagos, Panos; Borrelli, Pasquale; Meusburger, Katrin; Ballabio, Cristiano; Alewell, Christine

2015-04-01

Modelling soil erosion in European Union is of major importance for agro-environmental policies. Soil erosion estimates are important inputs for the Common Agricultural Policy (CAP) and the implementation of the Soil Thematic Strategy. Using the findings of a recent pan-European data collection through the EIONET network, it was concluded that most Member States are applying the empirical Revised Universal Soil Loss Equation (RUSLE) for the modelling soil erosion at National level. This model was chosen for the pan-European soil erosion risk assessment and it is based on 6 input factors. Compared to past approaches, each of the factors is modelled using the latest pan-European datasets, expertise and data from Member states and high resolution remote sensing data. The soil erodibility (K-factor) is modelled using the recently published LUCAS topsoil database with 20,000 point measurements and incorporating the surface stone cover which can reduce K-factor by 15%. The rainfall erosivity dataset (R-factor) has been implemented using high temporal resolution rainfall data from more than 1,500 precipitation stations well distributed in Europe. The cover-management (C-factor) incorporates crop statistics and management practices such as cover crops, tillage practices and plant residuals. The slope length and steepness (combined LS-factor) is based on the first ever 25m Digital Elevation Model (DEM) of Europe. Finally, the support practices (P-factor) is modelled for first time at this scale taking into account the 270,000 LUCAS earth observations and the Good Agricultural and Environmental Condition (GAEC) that farmers have to follow in Europe. The high resolution input layers produce the final soil erosion risk map at 100m resolution and allow policy makers to run future land use, management and climate change scenarios.

An Estimation of the Climatic Effects of Stratospheric Ozone Losses during the 1980s. Appendix K

NASA Technical Reports Server (NTRS)

MacKay, Robert M.; Ko, Malcolm K. W.; Shia, Run-Lie; Yang, Yajaing; Zhou, Shuntai; Molnar, Gyula

1997-01-01

In order to study the potential climatic effects of the ozone hole more directly and to assess the validity of previous lower resolution model results, the latest high spatial resolution version of the Atmospheric and Environmental Research, Inc., seasonal radiative dynamical climate model is used to simulate the climatic effects of ozone changes relative to the other greenhouse gases. The steady-state climatic effect of a sustained decrease in lower stratospheric ozone, similar in magnitude to the observed 1979-90 decrease, is estimated by comparing three steady-state climate simulations: 1) 1979 greenhouse gas concentrations and 1979 ozone, II) 1990 greenhouse gas concentrations with 1979 ozone, and III) 1990 greenhouse gas concentrations with 1990 ozone. The simulated increase in surface air temperature resulting from nonozone greenhouse gases is 0.272 K. When changes in lower stratospheric ozone are included, the greenhouse warming is 0.165 K, which is approximately 39% lower than when ozone is fixed at the 1979 concentrations. Ozone perturbations at high latitudes result in a cooling of the surface-troposphere system that is greater (by a factor of 2.8) than that estimated from the change in radiative forcing resulting from ozone depiction and the model's 2 x CO, climate sensitivity. The results suggest that changes in meridional heat transport from low to high latitudes combined with the decrease in the infrared opacity of the lower stratosphere are very important in determining the steady-state response to high latitude ozone losses. The 39% compensation in greenhouse warming resulting from lower stratospheric ozone losses is also larger than the 28% compensation simulated previously by the lower resolution model. The higher resolution model is able to resolve the high latitude features of the assumed ozone perturbation, which are important in determining the overall climate sensitivity to these perturbations.

Colloquium on High Resolution Molecular Spectroscopy (8th), 19-23 September 1983 (Colloque sur la Spectroscopie Moleculaire a Haute Resolution (Huitieme), 19-23 Septembre 1983).

DTIC Science & Technology

1983-09-23

avec lea autres State. A FITTING PROCEDURE FOP EXTENSIVELY PERTURBED HAMILTONIANS APPLICATION TO THE A1I- STATE OF CO ANDRE LE FLOCH AND JEAN MASSON...BENICHOU, Jean -Claude DEROCHE Laboratoire d’Infrarouge, Associg au C.N.R.S. Universitf de Paris-Sud, Bitiment 350 91405 ORSAY Cfdex, France Le pompage...MEUDON, FRANCE and Jean -Yves RONCIN Equipe de Spectroscopie, C.N.R.S. (L.A. 171, Universitis de Lyon I et Saint-Etienne) 158 bis Cours Fauriel, 42023

LONG TERM METABOLIC CONSEQUENCES OF EXPOSURES TO MULTIPOLLUTANT ATMOSPHERES IN THE GREAT LAKES REGION

EPA Science Inventory

Using state- of-the-art mobile inhalation exposure systems available at our laboratory (OASIS 1 and 2) and at Michigan State University (AirCARE 1 and 2), along with novel and high-resolution exposure characterization methods of our collaborators at The University of Michigan ...

Effect of land cover change on snow free surface albedo across the continental United States

EPA Science Inventory

Land cover changes (e.g., forest to grassland) affect albedo, and changes in albedo can influence radiative forcing (warming, cooling). We empirically tested albedo response to land cover change for 130 locations across the continental United States using high resolution (30 m-&t...

High-resolution boomer seismic-reflection profiles of the shelf off southern California from cruise A-1-00-SC: Santa Monica Bay to San Diego

USGS Publications Warehouse

Gutmacher, Christina E.; Ross, Stephanie L.; Triezenberg, Peter J.; Sliter, Ray W.; Normark, William R.; Edwards, Brian D.

2006-01-01

High-resolution boomer data were collected in the California Continental Borderland as part of the southern California Earthquake Hazards Task of the Southern California Coastal and Marine Geology Regional Investigations Project. During the period from 1997 to 2002, five data-acquisition cruises collected seismic-reflection data using several different systems from offshore Santa Barbara, California, south to the Exclusive Economic Zone boundary with Mexico. A key mission of this project was to map late Quaternary deformation in addition to improving our understanding of which offshore fault zones might have potential to damage highly populated areas of southern California. State regulations concerning the use of seismic-reflection equipment within three miles of the coastline precluded the routine gathering of high-resolution multichannel data in that swath adjacent to the coast. Boomer seismic-reflection data, however, can be obtained within the state 3-mile limit provided the operation receives authorization from the California State Lands Commission. The Geopulse boomer data accessible through this report were collected on the cruise A-1-00-SC, which was the only survey where we requested permission to work inside the 3-mile limit of the State of California. These data are critical to discovering connections between onshore and offshore faults, the overall lengths of which are related to the potential size of an earthquake that might be generated along them. The 2000 survey was designed to fill the gap between onshore data and reflection data obtained in deeper water on previous cruises as well as data anticipated from future surveys. This report includes trackline maps showing the location of the data, as well as both digital data files (SEG-Y) and images of all of the profiles.

Experimental flat-panel high-spatial-resolution volume CT of the temporal bone.

PubMed

Gupta, Rajiv; Bartling, Soenke H; Basu, Samit K; Ross, William R; Becker, Hartmut; Pfoh, Armin; Brady, Thomas; Curtin, Hugh D

2004-09-01

A CT scanner employing a digital flat-panel detector is capable of very high spatial resolution as compared with a multi-section CT (MSCT) scanner. Our purpose was to determine how well a prototypical volume CT (VCT) scanner with a flat-panel detector system defines fine structures in temporal bone. Four partially manipulated temporal-bone specimens were imaged by use of a prototypical cone-beam VCT scanner with a flat-panel detector system at an isometric resolution of 150 microm at the isocenter. These specimens were also depicted by state-of-the-art multisection CT (MSCT). Forty-two structures imaged by both scanners were qualitatively assessed and rated, and scores assigned to VCT findings were compared with those of MSCT. Qualitative assessment of anatomic structures, lesions, cochlear implants, and middle-ear hearing aids indicated that image quality was significantly better with VCT (P < .001). Structures near the spatial-resolution limit of MSCT (e.g., bony covering of the tympanic segment of the facial canal, the incudo-stapedial joint, the proximal vestibular aqueduct, the interscalar septum, and the modiolus) had higher contrast and less partial-volume effect with VCT. The flat-panel prototype provides better definition of fine osseous structures of temporal bone than that of currently available MSCT scanners. This study provides impetus for further research in increasing spatial resolution beyond that offered by the current state-of-the-art scanners.

A review of surface energy balance models for estimating actual evapotranspiration with remote sensing at high spatiotemporal resolution over large extents

USGS Publications Warehouse

McShane, Ryan R.; Driscoll, Katelyn P.; Sando, Roy

2017-09-27

Many approaches have been developed for measuring or estimating actual evapotranspiration (ETa), and research over many years has led to the development of remote sensing methods that are reliably reproducible and effective in estimating ETa. Several remote sensing methods can be used to estimate ETa at the high spatial resolution of agricultural fields and the large extent of river basins. More complex remote sensing methods apply an analytical approach to ETa estimation using physically based models of varied complexity that require a combination of ground-based and remote sensing data, and are grounded in the theory behind the surface energy balance model. This report, funded through cooperation with the International Joint Commission, provides an overview of selected remote sensing methods used for estimating water consumed through ETa and focuses on Mapping Evapotranspiration at High Resolution with Internalized Calibration (METRIC) and Operational Simplified Surface Energy Balance (SSEBop), two energy balance models for estimating ETa that are currently applied successfully in the United States. The METRIC model can produce maps of ETa at high spatial resolution (30 meters using Landsat data) for specific areas smaller than several hundred square kilometers in extent, an improvement in practice over methods used more generally at larger scales. Many studies validating METRIC estimates of ETa against measurements from lysimeters have shown model accuracies on daily to seasonal time scales ranging from 85 to 95 percent. The METRIC model is accurate, but the greater complexity of METRIC results in greater data requirements, and the internalized calibration of METRIC leads to greater skill required for implementation. In contrast, SSEBop is a simpler model, having reduced data requirements and greater ease of implementation without a substantial loss of accuracy in estimating ETa. The SSEBop model has been used to produce maps of ETa over very large extents (the conterminous United States) using lower spatial resolution (1 kilometer) Moderate Resolution Imaging Spectroradiometer (MODIS) data. Model accuracies ranging from 80 to 95 percent on daily to annual time scales have been shown in numerous studies that validated ETa estimates from SSEBop against eddy covariance measurements. The METRIC and SSEBop models can incorporate low and high spatial resolution data from MODIS and Landsat, but the high spatiotemporal resolution of ETa estimates using Landsat data over large extents takes immense computing power. Cloud computing is providing an opportunity for processing an increasing amount of geospatial “big data” in a decreasing period of time. For example, Google Earth EngineTM has been used to implement METRIC with automated calibration for regional-scale estimates of ETa using Landsat data. The U.S. Geological Survey also is using Google Earth EngineTM to implement SSEBop for estimating ETa in the United States at a continental scale using Landsat data.

Non-Destructive High-Resolution Organic Matter Record on Lake Sediment using Steady-State Solid Phase Fluorescence: Organic Matter Quality and Quantity Assessment.

NASA Astrophysics Data System (ADS)

Quiers, M.; Perrette, Y.; Etienne, D.; Develle, A. L.; Jacq, K.

2017-12-01

The use of organic proxies increases in paleoenvironmental reconstructions from natural archives. Major advances have been achieved by the development of new highly informative molecular proxies usually linked to specific compounds. While studies focused on targeted compounds, offering a high information degree, advances on bulk organic matter are limited. However, this bulk is the main contributor to carbon cycle and has been shown to be a driver of many mineral or organic compounds transfer and record. Development of target proxies need complementary information on bulk organic matter to understand biases link to controlling factors or analytical methods, and provide a robust interpretation. Fluorescence methods have often been employed to characterize and quantify organic matter. However, these technics are mainly developed for liquid samples, inducing material and resolution loss when working on natural archives (either stalagmite or sediments). High-resolution solid phase fluorescence (SPF) was developed on speleothems. This method allows now to analyse organic matter quality and quantity if procedure to constrain the optical density are adopted. In fact, a calibration method using liquid phase fluorescence (LPF) was developed for speleothem, allowing to quantify organic carbon at high-resolution. We report here an application of such a procedure SPF/LPF measurements on lake sediments. In order to avoid sediment matrix effects on the fluorescence signal, a calibration using LPF measurements was realised. First results using this method provided organic matter quality record of different organic matter compounds (humic-like, protein-like and chlorophylle-like compounds) at high resolution for the sediment core. High resolution organic matter fluxes are obtained in a second time, applying pragmatic chemometrics model (non linear models, partial least square models) on high resolution fluorescence data. SPF method can be considered as a promising tool for high resolution record on organic matter quality and quantity. Potential application of this method will be evocated (lake ecosystem dynamic, changes in trophic levels)

Going Beyond Einstein with the Constellation-X Mission

NASA Technical Reports Server (NTRS)

White, Nicholas

2007-01-01

The Constellation-X mission will address the questions: "What happens to matter close to a black hole?" and "What is Dark Energy?" These questions are central to the NASA Beyond Einstein Program, where Constellation-X plays a central role. The mission will address these questions by using high throughput X-ray spectroscopy to observe the effects of strong gravity close to the event horizon of black holes, and to observe the formation and evolution of clusters of galaxies in order to precisely determine Cosmological parameters. To achieve these primary science goals requires a factor of 25-100 increase in sensitivity for high resolution X-ray spectroscopy.'The mission will also perform routine high-resolution X-ray spectroscopy of faint 2nd extended X-ray source populations. This will provide diagnostic information such as density, elemental abundances, velocity; and ionization state for a wide range of astrophysical problems, including new constraints on the Neutron Star equation of state.

High-resolution Fourier-transform infrared spectroscopy of the ν6 and Coriolis perturbation allowed ν10 modes of ketenimine.

PubMed

Bane, Michael K; Robertson, Evan G; Thompson, Christopher D; Appadoo, Dominique R T; McNaughton, Don

2011-12-14

High-resolution FTIR spectra of the short lived species ketenimine have been recorded in the region 700-1300 cm(-1) and over 1500 transitions of the ν(10) and ν(6) modes have been assigned. Effective rotational and centrifugal distortion parameters for the v(10) = 1 and v(6) = 1 (excluding K(a) = 5) states were determined by co-fitting transitions, and treating strong a- and c-axis Coriolis interactions between them. Other perturbations attributed to interactions with the v(8) = 2 and v(12) = 1 + v(8) = 1 dark-states were also observed and treated. The ν(10) transitions are predicted to be inherently very weak, but are enhanced by an intensity stealing effect with the highly IR active ν(6) mode. A mechanism for this intensity stealing in ketenimine is also detailed. © 2011 American Institute of Physics

ERIC First Analysis: 1978-79 National High School Debate Resolutions (What Should Be the Energy Policy of the United States?)

ERIC Educational Resources Information Center

Henderson, Bill

Intended for use by high school debaters and their teachers, this book provides guidelines for research on the debate topic for the 1978-1979 school year: "What should be the energy policy of the United States?" The first section is designed to broaden the student's comprehension of the debating process by focusing on the meaning of the…

Edge technique lidar for high accuracy, high spatial resolution wind measurement in the Planetary Boundary Layer

NASA Technical Reports Server (NTRS)

Korb, C. L.; Gentry, Bruce M.

1995-01-01

The goal of the Army Research Office (ARO) Geosciences Program is to measure the three dimensional wind field in the planetary boundary layer (PBL) over a measurement volume with a 50 meter spatial resolution and with measurement accuracies of the order of 20 cm/sec. The objective of this work is to develop and evaluate a high vertical resolution lidar experiment using the edge technique for high accuracy measurement of the atmospheric wind field to meet the ARO requirements. This experiment allows the powerful capabilities of the edge technique to be quantitatively evaluated. In the edge technique, a laser is located on the steep slope of a high resolution spectral filter. This produces large changes in measured signal for small Doppler shifts. A differential frequency technique renders the Doppler shift measurement insensitive to both laser and filter frequency jitter and drift. The measurement is also relatively insensitive to the laser spectral width for widths less than the width of the edge filter. Thus, the goal is to develop a system which will yield a substantial improvement in the state of the art of wind profile measurement in terms of both vertical resolution and accuracy and which will provide a unique capability for atmospheric wind studies.

A theoretical and experimental benchmark study of core-excited states in nitrogen

NASA Astrophysics Data System (ADS)

Myhre, Rolf H.; Wolf, Thomas J. A.; Cheng, Lan; Nandi, Saikat; Coriani, Sonia; Gühr, Markus; Koch, Henrik

2018-02-01

The high resolution near edge X-ray absorption fine structure spectrum of nitrogen displays the vibrational structure of the core-excited states. This makes nitrogen well suited for assessing the accuracy of different electronic structure methods for core excitations. We report high resolution experimental measurements performed at the SOLEIL synchrotron facility. These are compared with theoretical spectra calculated using coupled cluster theory and algebraic diagrammatic construction theory. The coupled cluster singles and doubles with perturbative triples model known as CC3 is shown to accurately reproduce the experimental excitation energies as well as the spacing of the vibrational transitions. The computational results are also shown to be systematically improved within the coupled cluster hierarchy, with the coupled cluster singles, doubles, triples, and quadruples method faithfully reproducing the experimental vibrational structure.

The Focusing Optics X-ray Solar Imager (FOXSI) SMEX Mission

NASA Astrophysics Data System (ADS)

Christe, S.; Shih, A. Y.; Krucker, S.; Glesener, L.; Saint-Hilaire, P.; Caspi, A.; Allred, J. C.; Battaglia, M.; Chen, B.; Drake, J. F.; Gary, D. E.; Goetz, K.; Gburek, S.; Grefenstette, B.; Hannah, I. G.; Holman, G.; Hudson, H. S.; Inglis, A. R.; Ireland, J.; Ishikawa, S. N.; Klimchuk, J. A.; Kontar, E.; Kowalski, A. F.; Massone, A. M.; Piana, M.; Ramsey, B.; Schwartz, R.; Steslicki, M.; Turin, P.; Ryan, D.; Warmuth, A.; Veronig, A.; Vilmer, N.; White, S. M.; Woods, T. N.

2017-12-01

We present FOXSI (Focusing Optics X-ray Solar Imager), a Small Explorer (SMEX) Heliophysics mission that is currently undergoing a Phase A concept study. FOXSI will provide a revolutionary new perspective on energy release and particle acceleration on the Sun. FOXSI is a direct imaging X-ray spectrometer with higher dynamic range and better than 10x the sensitivity of previous instruments. Flown on a 3-axis-stabilized spacecraft in low-Earth orbit, FOXSI uses high-angular-resolution grazing-incidence focusing optics combined with state-of-the-art pixelated solid-state detectors to provide direct imaging of solar hard X-rays for the first time. FOXSI is composed of a pair of x-ray telescopes with a 14-meter focal length enabled by a deployable boom. Making use of a filter-wheel and high-rate-capable solid-state detectors, FOXSI will be able to observe the largest flares without saturation while still maintaining the sensitivity to detect x-ray emission from weak flares, escaping electrons, and hot active regions. This mission concept is made possible by past experience with similar instruments on two FOXSI sounding rocket flights, in 2012 and 2014, and on the HEROES balloon flight in 2013. FOXSI's hard X-ray imager has a field of view of 9 arcminutes and an angular resolution of better than 8 arcsec; it will cover the energy range from 3 up to 50-70 keV with a spectral resolution of better than 1 keV; and it will have sub-second temporal resolution.

The Focusing Optics X-ray Solar Imager (FOXSI) SMEX Mission

NASA Astrophysics Data System (ADS)

Christe, S.; Shih, A. Y.; Krucker, S.; Glesener, L.; Saint-Hilaire, P.; Caspi, A.; Allred, J. C.; Battaglia, M.; Chen, B.; Drake, J. F.; Gary, D. E.; Goetz, K.; Grefenstette, B.; Hannah, I. G.; Holman, G.; Hudson, H. S.; Inglis, A. R.; Ireland, J.; Ishikawa, S. N.; Klimchuk, J. A.; Kontar, E.; Kowalski, A. F.; Massone, A. M.; Piana, M.; Ramsey, B.; Gubarev, M.; Schwartz, R. A.; Steslicki, M.; Ryan, D.; Turin, P.; Warmuth, A.; White, S. M.; Veronig, A.; Vilmer, N.; Dennis, B. R.

2016-12-01

We present FOXSI (Focusing Optics X-ray Solar Imager), a recently proposed Small Explorer (SMEX) mission that will provide a revolutionary new perspective on energy release and particle acceleration on the Sun. FOXSI is a direct imaging X-ray spectrometer with higher dynamic range and better than 10x the sensitivity of previous instruments. Flown on a 3-axis stabilized spacecraft in low-Earth orbit, FOXSI uses high-angular-resolution grazing-incidence focusing optics combined with state-of-the-art pixelated solid-state detectors to provide direct imaging of solar hard X-rays for the first time. FOXSI is composed of two individual x-ray telescopes with a 14-meter focal length enabled by a deployable boom. Making use of a filter-wheel and high-rate-capable solid-state detectors, FOXSI will be able to observe the largest flares without saturation while still maintaining the sensitivity to detect x-ray emission from weak flares, escaping electrons, and hot active regions. This SMEX mission is made possible by past experience with similar instruments on two sounding rocket flights, in 2012 and 2014, and on the HEROES balloon flight in 2013. FOXSI will image the Sun with a field of view of 9 arcminutes and an angular resolution of better than 8 arcsec; it will cover the energy range from 3 to 100 keV with a spectral resolution of better than 1 keV; and it will have sub-second temporal resolution.

Stimulated emission depletion microscopy resolves individual nitrogen vacancy centers in diamond nanocrystals.

PubMed

Arroyo-Camejo, Silvia; Adam, Marie-Pierre; Besbes, Mondher; Hugonin, Jean-Paul; Jacques, Vincent; Greffet, Jean-Jacques; Roch, Jean-François; Hell, Stefan W; Treussart, François

2013-12-23

Nitrogen-vacancy (NV) color centers in nanodiamonds are highly promising for bioimaging and sensing. However, resolving individual NV centers within nanodiamond particles and the controlled addressing and readout of their spin state has remained a major challenge. Spatially stochastic super-resolution techniques cannot provide this capability in principle, whereas coordinate-controlled super-resolution imaging methods, like stimulated emission depletion (STED) microscopy, have been predicted to fail in nanodiamonds. Here we show that, contrary to these predictions, STED can resolve single NV centers in 40-250 nm sized nanodiamonds with a resolution of ≈10 nm. Even multiple adjacent NVs located in single nanodiamonds can be imaged individually down to relative distances of ≈15 nm. Far-field optical super-resolution of NVs inside nanodiamonds is highly relevant for bioimaging applications of these fluorescent nanolabels. The targeted addressing and readout of individual NV(-) spins inside nanodiamonds by STED should also be of high significance for quantum sensing and information applications.

A High-Resolution Spatially Explicit Monte-Carlo Simulation Approach to Commercial and Residential Electricity and Water Demand Modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morton, April M; McManamay, Ryan A; Nagle, Nicholas N

Abstract As urban areas continue to grow and evolve in a world of increasing environmental awareness, the need for high resolution spatially explicit estimates for energy and water demand has become increasingly important. Though current modeling efforts mark significant progress in the effort to better understand the spatial distribution of energy and water consumption, many are provided at a course spatial resolution or rely on techniques which depend on detailed region-specific data sources that are not publicly available for many parts of the U.S. Furthermore, many existing methods do not account for errors in input data sources and may thereforemore » not accurately reflect inherent uncertainties in model outputs. We propose an alternative and more flexible Monte-Carlo simulation approach to high-resolution residential and commercial electricity and water consumption modeling that relies primarily on publicly available data sources. The method s flexible data requirement and statistical framework ensure that the model is both applicable to a wide range of regions and reflective of uncertainties in model results. Key words: Energy Modeling, Water Modeling, Monte-Carlo Simulation, Uncertainty Quantification Acknowledgment This manuscript has been authored by employees of UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the U.S. Department of Energy. Accordingly, the United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes.« less

High Performance Non-Dispersive X-Ray Spectrometers for Charge Exchange Measurements

NASA Technical Reports Server (NTRS)

Porter Frederick; Adams, J.; Beiersdorfer, P.; Brown, G. V.; Karkatoua, D.; Kelley, R. L.; Kilbourne, C. A.; Lautenagger, M.

2010-01-01

Currently, the only measurements of cosmological charge exchange have been made using low resolution, non-dispersive spectrometers like the PSPC on ROSAT and the CCD instruments on Chandra and XMM/Newton. However, upcoming cryogenic spectrometers on Astro-H and IXO will add vast new capabilities to investigate charge exchange in local objects such as comets and planetary atmospheres. They may also allow us to observe charge exchange in extra-solar objects such as galactic supernova remnants. With low spectral resolution instruments such as CCDs, x-ray emission due to charge exchange recombination really only provides information on the acceptor species, such as the solar wind. With the new breed of x-ray calorimeter instruments, emission from charge exchange becomes highly diagnostic allowing one to uniquely determine the acceptor species, ionization state, donor species and ionization state, and the relative velocity of the interaction. We will describe x-ray calorimeter instrumentation and its potential for charge exchange measurements in the near term. We will also touch on the instrumentation behind a decade of high resolution measurements of charge exchange using an x-ray calorimeter at the Lawrence Livermore National Laboratory.

Rapid high-resolution spin- and angle-resolved photoemission spectroscopy with pulsed laser source and time-of-flight spectrometer

NASA Astrophysics Data System (ADS)

Gotlieb, K.; Hussain, Z.; Bostwick, A.; Lanzara, A.; Jozwiak, C.

2013-09-01

A high-efficiency spin- and angle-resolved photoemission spectroscopy (spin-ARPES) spectrometer is coupled with a laboratory-based laser for rapid high-resolution measurements. The spectrometer combines time-of-flight (TOF) energy measurements with low-energy exchange scattering spin polarimetry for high detection efficiencies. Samples are irradiated with fourth harmonic photons generated from a cavity-dumped Ti:sapphire laser that provides high photon flux in a narrow bandwidth, with a pulse timing structure ideally matched to the needs of the TOF spectrometer. The overall efficiency of the combined system results in near-EF spin-resolved ARPES measurements with an unprecedented combination of energy resolution and acquisition speed. This allows high-resolution spin measurements with a large number of data points spanning multiple dimensions of interest (energy, momentum, photon polarization, etc.) and thus enables experiments not otherwise possible. The system is demonstrated with spin-resolved energy and momentum mapping of the L-gap Au(111) surface states, a prototypical Rashba system. The successful integration of the spectrometer with the pulsed laser system demonstrates its potential for simultaneous spin- and time-resolved ARPES with pump-probe based measurements.

High Resolution Land Use Land Cover Classification using Landsat Earth Observation Data for the Continental Africa

NASA Astrophysics Data System (ADS)

Midekisa, A.; Bennet, A.; Gething, P. W.; Holl, F.; Andrade-Pacheco, R.; Savory, D. J.; Hugh, S. J.

2016-12-01

Spatially detailed and temporally dynamic land use land cover data is necessary to monitor the state of the land surface for various applications. Yet, such data at a continental to global scale is lacking. Here, we developed high resolution (30 meter) annual land use land cover layers for the continental Africa using Google Earth Engine. To capture ground truth training data, high resolution satellite imageries were visually inspected and used to identify 7, 212 sample Landsat pixels that were comprised entirely of one of seven land use land cover classes (water, man-made impervious surface, high biomass, low biomass, rock, sand and bare soil). For model validation purposes, 80% of points from each class were used as training data, with 20% withheld as a validation dataset. Cloud free Landsat 7 annual composites for 2000 to 2015 were generated and spectral bands from the Landsat images were then extracted for each of the training and validation sample points. In addition to the Landsat spectral bands, spectral indices such as normalized difference vegetation index (NDVI) and normalized difference water index (NDWI) were used as covariates in the model. Additionally, calibrated night time light imageries from the National Oceanic and Atmospheric Administration (NOAA) were included as a covariate. A decision tree classification algorithm was applied to predict the 7 land cover classes for the periods 2000 to 2015 using the training dataset. Using the validation dataset, classification accuracy including omission error and commission error were computed for each land cover class. Model results showed that overall accuracy of classification was high (88%). This high resolution land cover product developed for the continental Africa will be available for public use and can potentially enhance the ability of monitoring and studying the state of the Earth's surface.

A Semi-Automated Machine Learning Algorithm for Tree Cover Delineation from 1-m Naip Imagery Using a High Performance Computing Architecture

NASA Astrophysics Data System (ADS)

Basu, S.; Ganguly, S.; Nemani, R. R.; Mukhopadhyay, S.; Milesi, C.; Votava, P.; Michaelis, A.; Zhang, G.; Cook, B. D.; Saatchi, S. S.; Boyda, E.

2014-12-01

Accurate tree cover delineation is a useful instrument in the derivation of Above Ground Biomass (AGB) density estimates from Very High Resolution (VHR) satellite imagery data. Numerous algorithms have been designed to perform tree cover delineation in high to coarse resolution satellite imagery, but most of them do not scale to terabytes of data, typical in these VHR datasets. In this paper, we present an automated probabilistic framework for the segmentation and classification of 1-m VHR data as obtained from the National Agriculture Imagery Program (NAIP) for deriving tree cover estimates for the whole of Continental United States, using a High Performance Computing Architecture. The results from the classification and segmentation algorithms are then consolidated into a structured prediction framework using a discriminative undirected probabilistic graphical model based on Conditional Random Field (CRF), which helps in capturing the higher order contextual dependencies between neighboring pixels. Once the final probability maps are generated, the framework is updated and re-trained by incorporating expert knowledge through the relabeling of misclassified image patches. This leads to a significant improvement in the true positive rates and reduction in false positive rates. The tree cover maps were generated for the state of California, which covers a total of 11,095 NAIP tiles and spans a total geographical area of 163,696 sq. miles. Our framework produced correct detection rates of around 85% for fragmented forests and 70% for urban tree cover areas, with false positive rates lower than 3% for both regions. Comparative studies with the National Land Cover Data (NLCD) algorithm and the LiDAR high-resolution canopy height model shows the effectiveness of our algorithm in generating accurate high-resolution tree cover maps.

A Hybrid CPU-GPU Accelerated Framework for Fast Mapping of High-Resolution Human Brain Connectome

PubMed Central

Ren, Ling; Xu, Mo; Xie, Teng; Gong, Gaolang; Xu, Ningyi; Yang, Huazhong; He, Yong

2013-01-01

Recently, a combination of non-invasive neuroimaging techniques and graph theoretical approaches has provided a unique opportunity for understanding the patterns of the structural and functional connectivity of the human brain (referred to as the human brain connectome). Currently, there is a very large amount of brain imaging data that have been collected, and there are very high requirements for the computational capabilities that are used in high-resolution connectome research. In this paper, we propose a hybrid CPU-GPU framework to accelerate the computation of the human brain connectome. We applied this framework to a publicly available resting-state functional MRI dataset from 197 participants. For each subject, we first computed Pearson’s Correlation coefficient between any pairs of the time series of gray-matter voxels, and then we constructed unweighted undirected brain networks with 58 k nodes and a sparsity range from 0.02% to 0.17%. Next, graphic properties of the functional brain networks were quantified, analyzed and compared with those of 15 corresponding random networks. With our proposed accelerating framework, the above process for each network cost 80∼150 minutes, depending on the network sparsity. Further analyses revealed that high-resolution functional brain networks have efficient small-world properties, significant modular structure, a power law degree distribution and highly connected nodes in the medial frontal and parietal cortical regions. These results are largely compatible with previous human brain network studies. Taken together, our proposed framework can substantially enhance the applicability and efficacy of high-resolution (voxel-based) brain network analysis, and have the potential to accelerate the mapping of the human brain connectome in normal and disease states. PMID:23675425

Para-hydrogen raser delivers sub-millihertz resolution in nuclear magnetic resonance

NASA Astrophysics Data System (ADS)

Suefke, Martin; Lehmkuhl, Sören; Liebisch, Alexander; Blümich, Bernhard; Appelt, Stephan

2017-06-01

The precision of nuclear magnetic resonance spectroscopy (NMR) is limited by the signal-to-noise ratio, the measurement time Tm and the linewidth Δν = 1/(πT2). Overcoming the T 2 limit is possible if the nuclear spins of a molecule emit continuous radio waves. Lasers and masers are self-organized systems which emit coherent radiation in the optical and micro-wave regime. Both are based on creating a population inversion of specific energy states. Here we show continuous oscillations of proton spins of organic molecules in the radiofrequency regime (raser). We achieve this by coupling a population inversion created through signal amplification by reversible exchange (SABRE) to a high-quality-factor resonator. For the case of 15N labelled molecules, we observe multi-mode raser activity, which reports different spin quantum states. The corresponding 1H-15N J-coupled NMR spectra exhibit unprecedented sub-millihertz resolution and can be explained assuming two-spin ordered quantum states. Our findings demonstrate a substantial improvement in the frequency resolution of NMR.

High-resolution study of Gamow-Teller transitions via the 54Fe(3He,t)54Co reaction

NASA Astrophysics Data System (ADS)

Adachi, T.; Fujita, Y.; Bacher, A. D.; Berg, G. P. A.; Black, T.; de Frenne, D.; Foster, C. C.; Fujita, H.; Fujita, K.; Hatanaka, K.; Honma, M.; Jacobs, E.; Jänecke, J.; Kanzaki, K.; Katori, K.; Nakanishi, K.; Negret, A.; Otsuka, T.; Popescu, L.; Roberts, D. A.; Sakemi, Y.; Shimbara, Y.; Shimizu, Y.; Stephenson, E. J.; Tameshige, Y.; Tamii, A.; Uchida, M.; Ueno, H.; Yamanaka, T.; Yosoi, M.; Zell, K. O.

2012-02-01

The Gamow-Teller transition strengths, B(GT), in pf-shell nuclei are of interest in nuclear physics as well as in nuclear astrophysics. A high-resolution (3He,t) charge-exchange (CE) reaction was performed on the Tz=+1 nucleus 54Fe at 0∘ and at an intermediate incident energy of 140 MeV/nucleon for the study of precise GT transition strengths to the final Tz=0 nucleus 54Co. By applying dispersion matching techniques for a high-quality 3He beam at RCNP, an energy resolution of 21 keV and an angular resolution of 5 mr were realized. The bumplike structure of the GT resonance observed in low-resolution CE reactions at around the excitation energy (Ex) of 10 MeV was resolved in individual L = 0, GT states. Excitation strengths were obtained for these GT states. If the R2 value that is defined by the ratio between GT and Fermi unit cross sections is known, the B(GT) values can be determined from the excitation strengths. For the derivation of the R2 value, the “merged analysis” combining the GT strength distribution from the 54Fe(3He,t)54Co study and the half-life from a 54Ni β decay was used, where T=1 isospin symmetry for A=54 isobars was assumed. The GT strengths were compared with a shell-model calculation using the GXPF1 interaction. The final GT states can have the isospin values T = 0, 1, and 2. The isospin T of each GT state observed in the 8.3≤Ex≤12.0 MeV region of the 54Fe(3He,t)54Co spectrum was identified by comparing the excitation strength with that of corresponding M1 state observed in a 54Fe(p,p')54Fe experiment. The B(GT) values of the states identified to have T=2, in particular, are of importance for the calculation of the electron capture rates at the core-collapse stage of presupernovae. The B(GT) strengths were further compared with B(M1) strengths measured in the 54Fe(e,e')54Fe reaction. In the M1 excitation using an electromagnetic probe, isoscalar (IS) and isovector (IV) orbital type operators are active in addition to the IV spin type operator that mediates the GT transitions. The contributions of the IS and IV orbital terms were studied by calculating the ratio of the strengths of analogous M1 and GT transitions.

A study on the anisole-water complex by molecular beam-electronic spectroscopy and molecular mechanics calculations.

PubMed

Becucci, M; Pietraperzia, G; Pasquini, M; Piani, G; Zoppi, A; Chelli, R; Castellucci, E; Demtroeder, W

2004-03-22

An experimental and theoretical study is made on the anisole-water complex. It is the first van der Waals complex studied by high resolution electronic spectroscopy in which the water is seen acting as an acid. Vibronically and rotationally resolved electronic spectroscopy experiments and molecular mechanics calculations are used to elucidate the structure of the complex in the ground and first electronic excited state. Some internal dynamics in the system is revealed by high resolution spectroscopy. (c) 2004 American Institute of Physics

A small-displacement sensor using total internal reflection theory and surface plasmon resonance technology for heterodyne interferometry.

PubMed

Wang, Shinn-Fwu

2009-01-01

A small-displacement sensor based on total-internal reflection theory and surface plasmon resonance technology is proposed for use in heterodyne interferometry. A small displacement can be obtained simply by measuring the variation in phase difference between s- and p-polarization states with the small-displacement sensor. The theoretical displacement resolution of the small-displacement sensor can reach 0.45 nm. The sensor has some additional advantages, e.g., a simple optical setup, high resolution, high sensitivity and rapid measurement. Its feasibility is also demonstrated.

Accessing High Spatial Resolution in Astronomy Using Interference Methods

NASA Astrophysics Data System (ADS)

Carbonel, Cyril; Grasset, Sébastien; Maysonnave, Jean

2018-04-01

In astronomy, methods such as direct imaging or interferometry-based techniques (Michelson stellar interferometry for example) are used for observations. A particular advantage of interferometry is that it permits greater spatial resolution compared to direct imaging with a single telescope, which is limited by diffraction owing to the aperture of the instrument as shown by Rueckner et al. in a lecture demonstration. The focus of this paper, addressed to teachers and/or students in high schools and universities, is to easily underline both an application of interferometry in astronomy and stress its interest for resolution. To this end very simple optical experiments are presented to explain all the concepts. We show how an interference pattern resulting from the combined signals of two telescopes allows us to measure the distance between two stars with a resolution beyond the diffraction limit. Finally this work emphasizes the breathtaking resolution obtained in state-of-the-art instruments such as the VLTi (Very Large Telescope interferometer).

Compressed Sensing for Resolution Enhancement of Hyperpolarized 13C Flyback 3D-MRSI

PubMed Central

Hu, Simon; Lustig, Michael; Chen, Albert P.; Crane, Jason; Kerr, Adam; Kelley, Douglas A.C.; Hurd, Ralph; Kurhanewicz, John; Nelson, Sarah J.; Pauly, John M.; Vigneron, Daniel B.

2008-01-01

High polarization of nuclear spins in liquid state through dynamic nuclear polarization has enabled the direct monitoring of 13C metabolites in vivo at very high signal to noise, allowing for rapid assessment of tissue metabolism. The abundant SNR afforded by this hyperpolarization technique makes high resolution 13C 3D-MRSI feasible. However, the number of phase encodes that can be fit into the short acquisition time for hyperpolarized imaging limits spatial coverage and resolution. To take advantage of the high SNR available from hyperpolarization, we have applied compressed sensing to achieve a factor of 2 enhancement in spatial resolution without increasing acquisition time or decreasing coverage. In this paper, the design and testing of compressed sensing suited for a flyback 13C 3D-MRSI sequence are presented. The key to this design was the undersampling of spectral k-space using a novel blipped scheme, thus taking advantage of the considerable sparsity in typical hyperpolarized 13C spectra. Phantom tests validated the accuracy of the compressed sensing approach and initial mouse experiments demonstrated in vivo feasibility. PMID:18367420

California State Waters Map Series Data Catalog

USGS Publications Warehouse

Golden, Nadine E.

2013-01-01

In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California's State Waters. The CSMP approach is to create highly detailed seafloor maps and associated data layers through the collection, integration, interpretation, and visualization of swath sonar data, acoustic backscatter, seafloor video, seafloor photography, high-resolution seismic-reflection profiles, and bottom-sediment sampling data. CSMP has divided coastal California into 110 map blocks (fig. 1), each to be published individually as USGS Scientific Investigations Maps (SIMs) at a scale of 1:24,000. The map products display seafloor morphology and character, identify potential marine benthic habitats, and illustrate both the seafloor geology and shallow (to about 100 m) subsurface geology. This CSMP data catalog contains much of the data used to prepare the SIMs in the California State Waters Map Series. Other data that were used to prepare the maps were compiled from previously published sources (for example, onshore geology) and, thus, are not included herein.

Measurement of DNA translocation dynamics in a solid-state nanopore at 100-ns temporal resolution

PubMed Central

Shekar, Siddharth; Niedzwiecki, David J.; Chien, Chen-Chi; Ong, Peijie; Fleischer, Daniel A.; Lin, Jianxun; Rosenstein, Jacob K.; Drndic, Marija; Shepard, Kenneth L.

2017-01-01

Despite the potential for nanopores to be a platform for high-bandwidth study of single-molecule systems, ionic current measurements through nanopores have been limited in their temporal resolution by noise arising from poorly optimized measurement electronics and large parasitic capacitances in the nanopore membranes. Here, we present a complementary metal-oxide-semiconductor (CMOS) nanopore (CNP) amplifier capable of low noise recordings at an unprecedented 10 MHz bandwidth. When integrated with state-of-the-art solid-state nanopores in silicon nitride membranes, we achieve an SNR of greater than 10 for ssDNA translocations at a measurement bandwidth of 5 MHz, which represents the fastest ion current recordings through nanopores reported to date. We observe transient features in ssDNA translocation events that are as short as 200 ns, which are hidden even at bandwidths as high as 1 MHz. These features offer further insights into the translocation kinetics of molecules entering and exiting the pore. This platform highlights the advantages of high-bandwidth translocation measurements made possible by integrating nanopores and custom-designed electronics. PMID:27332998

A device to measure the effects of strong magnetic fields on the image resolution of PET scanners

NASA Astrophysics Data System (ADS)

Burdette, D.; Albani, D.; Chesi, E.; Clinthorne, N. H.; Cochran, E.; Honscheid, K.; Huh, S. S.; Kagan, H.; Knopp, M.; Lacasta, C.; Mikuz, M.; Schmalbrock, P.; Studen, A.; Weilhammer, P.

2009-10-01

Very high resolution images can be achieved in small animal PET systems utilizing solid state silicon pad detectors. As these systems approach sub-millimeter resolutions, the range of the positron is becoming the dominant contribution to image blur. The size of the positron range effect depends on the initial positron energy and hence the radioactive tracer used. For higher energy positron emitters, such as Ga68 and Tc94m, which are gaining importance in small animal studies, the width of the annihilation point distribution dominates the spatial resolution. This positron range effect can be reduced by embedding the field of view of the PET scanner in a strong magnetic field. In order to confirm this effect experimentally, we developed a high resolution PET instrument based on silicon pad detectors that can operate in a 7 T magnetic field. In this paper, we describe the instrument and present initial results of a study of the effects of magnetic fields up to 7 T on PET image resolution for Na22 and Ga68 point sources.

Towards ultrahigh resting-state functional connectivity in the mouse brain using photoacoustic microscopy

NASA Astrophysics Data System (ADS)

Hariri, Ali; Bely, Nicholas; Chen, Chen; Nasiriavanaki, Mohammadreza

2016-03-01

The increasing use of mouse models for human brain disease studies, coupled with the fact that existing high-resolution functional imaging modalities cannot be easily applied to mice, presents an emerging need for a new functional imaging modality. Utilizing both mechanical and optical scanning in the photoacoustic microscopy, we can image spontaneous cerebral hemodynamic fluctuations and their associated functional connections in the mouse brain. The images is going to be acquired noninvasively with a fast frame rate, a large field of view, and a high spatial resolution. We developed an optical resolution photoacoustic microscopy (OR-PAM) with diode laser. Laser light was raster scanned due to XY-stage movement. Images from ultra-high OR-PAM can then be used to study brain disorders such as stroke, Alzheimer's, schizophrenia, multiple sclerosis, autism, and epilepsy.

Beyond RGB: Very high resolution urban remote sensing with multimodal deep networks

NASA Astrophysics Data System (ADS)

Audebert, Nicolas; Le Saux, Bertrand; Lefèvre, Sébastien

2018-06-01

In this work, we investigate various methods to deal with semantic labeling of very high resolution multi-modal remote sensing data. Especially, we study how deep fully convolutional networks can be adapted to deal with multi-modal and multi-scale remote sensing data for semantic labeling. Our contributions are threefold: (a) we present an efficient multi-scale approach to leverage both a large spatial context and the high resolution data, (b) we investigate early and late fusion of Lidar and multispectral data, (c) we validate our methods on two public datasets with state-of-the-art results. Our results indicate that late fusion make it possible to recover errors steaming from ambiguous data, while early fusion allows for better joint-feature learning but at the cost of higher sensitivity to missing data.

Effects of Drake Passage on a strongly eddying global ocean

NASA Astrophysics Data System (ADS)

Viebahn, Jan; von der Heydt, Anna S.; Dijkstra, Henk A.

2015-04-01

During the past 65 Million (Ma) years, Earth's climate has undergone a major change from warm 'greenhouse' to colder 'icehouse' conditions with extensive ice sheets in the polar regions of both hemispheres. The Eocene-Oligocene (~34 Ma) and Oligocene-Miocene (~23 Ma) boundaries reflect major transitions in Cenozoic global climate change. Proposed mechanisms of these transitions include reorganization of ocean circulation due to critical gateway opening/deepening, changes in atmospheric CO2-concentration, and feedback mechanisms related to land-ice formation. Drake Passage (DP) is an intensively studied gateway because it plays a central role in closing the transport pathways of heat and chemicals in the ocean. The climate response to a closed DP has been explored with a variety of general circulation models, however, all of these models employ low model-grid resolutions such that the effects of subgrid-scale fluctuations ('eddies') are parameterized. We present results of the first high-resolution (0.1° horizontally) realistic global ocean model simulation with a closed DP in which the eddy field is largely resolved. The simulation extends over more than 200 years such that the strong transient adjustment process is passed and a near-equilibrium ocean state is reached. The effects of DP are diagnosed by comparing with both an open DP high-resolution control simulation (of same length) and corresponding low-resolution simulations. By focussing on the heat/tracer transports we demonstrate that the results are twofold: Considering spatially integrated transports the overall response to a closed DP is well captured by low-resolution simulations. However, looking at the actual spatial distributions drastic differences appear between far-scattered high-resolution and laminar-uniform low-resolution fields. We conclude that sparse and highly localized tracer proxy observations have to be interpreted carefully with the help of high-resolution model simulations.

Rovibrational study of the 2ν2 band of D213CO by high-resolution Fourier transform infrared spectroscopy

NASA Astrophysics Data System (ADS)

Wu, Q. Y.; Tan, T. L.; A'dawiah, Rabia'tul; Ng, L. L.

2018-03-01

The high-resolution FTIR spectrum of the 2ν2 band (3250-3380 cm-1) of D213CO was recorded at an unapodized resolution of 0.0063 cm-1. A total of 747 rovibrational transitions have been assigned and fitted up to J″ = 32 and Ka″ = 10 using the Watson's A-reduced Hamiltonian in the Ir representation. A set of accurate upper state (v2 = 2) rovibrational constants, three rotational and five quartic centrifugal distortion constants, were determined for the first time. The band center of the 2ν2 band was found to be 3326.765109 ± 0.000079 cm-1. The rms deviation of the rovibrational fit was 0.00096 cm-1.

Note: Near infrared spectral and transient measurements of PbS quantum dots luminescence.

PubMed

Parfenov, P S; Litvin, A P; Ushakova, E V; Fedorov, A V; Baranov, A V; Berwick, K

2013-11-01

We describe an experimental setup for the characterization of luminescence from nanostructures. The setup is intended for steady-state and time-resolved luminescence measurements in the near-infrared region. The setup allows us to study spectral luminescence properties in the spectral range of 0.8-2.0 μm with high spectral resolution and kinetic luminescence properties between 0.8 and 1.7 μm with a time resolution of 3 ns. The capabilities of the system are illustrated by taking luminescence measurements from PbS quantum dots. We established the size dependencies of the optical properties of the PbS quantum dots over a wide spectral range. Finally, the energy transfer process was studied with a high temporal and spectral resolution.

Thermodynamical effects and high resolution methods for compressible fluid flows

NASA Astrophysics Data System (ADS)

Li, Jiequan; Wang, Yue

2017-08-01

One of the fundamental differences of compressible fluid flows from incompressible fluid flows is the involvement of thermodynamics. This difference should be manifested in the design of numerical schemes. Unfortunately, the role of entropy, expressing irreversibility, is often neglected even though the entropy inequality, as a conceptual derivative, is verified for some first order schemes. In this paper, we refine the GRP solver to illustrate how the thermodynamical variation is integrated into the design of high resolution methods for compressible fluid flows and demonstrate numerically the importance of thermodynamic effects in the resolution of strong waves. As a by-product, we show that the GRP solver works for generic equations of state, and is independent of technical arguments.

High-Resolution FTIR Spectrum of the ν 5Band of HCOOD

NASA Astrophysics Data System (ADS)

Goh, K. L.; Ong, P. P.; Tan, T. L.; Teo, H. H.; Wang, W. F.

1998-10-01

The high-resolution Fourier transform infrared spectrum of HCOOD has been measured in the ν5region between 1120 and 1220 cm-1with a resolution of 0.004 cm-1. As expected for an in-plane vibrational fundamental mode, the ν5band is a hybrid band consisting of botha-type andb-type transitions. Using the Watson'sA-reduced Hamiltonian in theIrrepresentation, 1943 infrared transitions have been assigned and fitted to give 12 rovibrational constants for thev5= 1 state. The ν5band is primarilyAtype with a band center at 1177.09378 ± 0.00002 cm-1. It is found that ν5is slightly perturbed by the nearby 2ν7. About 90 perturbed transitions were identified.

Amperometric Carbon Fiber Nitrite Microsensor for In Situ Biofilm Monitoring

EPA Science Inventory

A highly selective needle type solid state amperometric nitrite microsensor based on direct nitrite oxidation on carbon fiber was developed using a simplified fabrication method. The microsensor’s tip diameter was approximately 7 µm, providing a high spatial resolution of at lea...

The nature of the excited state of the reaction center of photosystem II of green plants: A high-resolution fluorescence spectroscopy study

PubMed Central

Peterman, Erwin J. G.; van Amerongen, Herbert; van Grondelle, Rienk; Dekker, Jan P.

1998-01-01

We studied the electronically excited state of the isolated reaction center of photosystem II with high-resolution fluorescence spectroscopy at 5 K and compared the obtained spectral features with those obtained earlier for the primary electron donor. The results show that there is a striking resemblance between the emitting and charge-separating states in the photosystem II reaction center, such as a very similar shape of the phonon wing with characteristic features at 19 and 80 cm−1, almost identical frequencies of a number of vibrational modes, a very similar double-Gaussian shape of the inhomogeneous distribution function, and relatively strong electron-phonon coupling for both states. We suggest that the emission at 5 K originates either from an exciton state delocalized over the inactive branch of the photosystem or from a fraction of the primary electron donor that is long-lived at 5 K. The latter possibility can be explained by a distribution of the free energy difference of the primary charge separation reaction around zero. Both possibilities are in line with the idea that the state that drives primary charge separation in the reaction center of photosystem II is a collective state, with contributions from all chlorophyll molecules in the central part of the complex. PMID:9600929

Fusion of PET and MRI for Hybrid Imaging

NASA Astrophysics Data System (ADS)

Cho, Zang-Hee; Son, Young-Don; Kim, Young-Bo; Yoo, Seung-Schik

Recently, the development of the fusion PET-MRI system has been actively studied to meet the increasing demand for integrated molecular and anatomical imaging. MRI can provide detailed anatomical information on the brain, such as the locations of gray and white matter, blood vessels, axonal tracts with high resolution, while PET can measure molecular and genetic information, such as glucose metabolism, neurotransmitter-neuroreceptor binding and affinity, protein-protein interactions, and gene trafficking among biological tissues. State-of-the-art MRI systems, such as the 7.0 T whole-body MRI, now can visualize super-fine structures including neuronal bundles in the pons, fine blood vessels (such as lenticulostriate arteries) without invasive contrast agents, in vivo hippocampal substructures, and substantia nigra with excellent image contrast. High-resolution PET, known as High-Resolution Research Tomograph (HRRT), is a brain-dedicated system capable of imaging minute changes of chemicals, such as neurotransmitters and -receptors, with high spatial resolution and sensitivity. The synergistic power of the two, i.e., ultra high-resolution anatomical information offered by a 7.0 T MRI system combined with the high-sensitivity molecular information offered by HRRT-PET, will significantly elevate the level of our current understanding of the human brain, one of the most delicate, complex, and mysterious biological organs. This chapter introduces MRI, PET, and PET-MRI fusion system, and its algorithms are discussed in detail.

High Speed Computational Ghost Imaging via Spatial Sweeping

NASA Astrophysics Data System (ADS)

Wang, Yuwang; Liu, Yang; Suo, Jinli; Situ, Guohai; Qiao, Chang; Dai, Qionghai

2017-03-01

Computational ghost imaging (CGI) achieves single-pixel imaging by using a Spatial Light Modulator (SLM) to generate structured illuminations for spatially resolved information encoding. The imaging speed of CGI is limited by the modulation frequency of available SLMs, and sets back its practical applications. This paper proposes to bypass this limitation by trading off SLM’s redundant spatial resolution for multiplication of the modulation frequency. Specifically, a pair of galvanic mirrors sweeping across the high resolution SLM multiply the modulation frequency within the spatial resolution gap between SLM and the final reconstruction. A proof-of-principle setup with two middle end galvanic mirrors achieves ghost imaging as fast as 42 Hz at 80 × 80-pixel resolution, 5 times faster than state-of-the-arts, and holds potential for one magnitude further multiplication by hardware upgrading. Our approach brings a significant improvement in the imaging speed of ghost imaging and pushes ghost imaging towards practical applications.

Amorphization dynamics of Ge{sub 2}Sb{sub 2}Te{sub 5} films upon nano- and femtosecond laser pulse irradiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siegel, J.; Gawelda, W.; Puerto, D.

2008-01-15

Phase transformations of crystalline Ge{sub 2}Sb{sub 2}Te{sub 5} films upon pulsed laser irradiation have been studied using in situ reflectivity measurements with temporal resolution. Two different configurations allowed point probing with nanosecond temporal resolution and imaging with subpicosecond temporal and micrometer spatial resolution. The role of the pulse duration and laser fluence on the dynamics of the phase change and the degree of amorphization is discussed. Several advantageous features of femtosecond compared to nanosecond laser-induced amorphization are identified. Moreover, a high-resolution study of the amorphization dynamics reveals the onset of amorphization at moderate fluences to occur within {approx}100 ps aftermore » arrival of the laser pulse. At high fluences, amorphization occurs after {approx}430 ps and the molten phase is characterized by an anomalously low reflectivity value, indicative of a state of extreme supercooling.« less

Femtosecond MeV Electron Energy-Loss Spectroscopy

NASA Astrophysics Data System (ADS)

Li, R. K.; Wang, X. J.

2017-11-01

Pump-probe electron energy-loss spectroscopy (EELS) with femtosecond temporal resolution will be a transformative research tool for studying nonequilibrium chemistry and electronic dynamics of matter. In this paper, we propose a concept of femtosecond EELS utilizing mega-electron-volt electron beams from a radio-frequency (rf) photocathode source. The high acceleration gradient and high beam energy of the rf gun are critical to the generation of 10-fs electron beams, which enables an improvement of the temporal resolution by more than 1 order of magnitude beyond the state of the art. In our proposal, the "reference-beam technique" relaxes the energy stability requirement of the rf power source by roughly 2 orders of magnitude. The requirements for the electron-beam quality, photocathode, spectrometer, and detector are also discussed. Supported by particle-tracking simulations, we demonstrate the feasibility of achieving sub-electron-volt energy resolution and approximately 10-fs temporal resolution with existing or near-future hardware performance.

Extreme storm surge modelling in the North Sea. The role of the sea state, forcing frequency and spatial forcing resolution

NASA Astrophysics Data System (ADS)

Ridder, Nina; de Vries, Hylke; Drijfhout, Sybren; van den Brink, Henk; van Meijgaard, Erik; de Vries, Hans

2018-02-01

This study shows that storm surge model performance in the North Sea is mostly unaffected by the application of temporal variations of surface drag due to changes in sea state provided the choice of a suitable constant Charnock parameter in the sea-state-independent case. Including essential meteorological features on smaller scales and minimising interpolation errors by increasing forcing data resolution are shown to be more important for the improvement of model performance particularly at the high tail of the probability distribution. This is found in a modelling study using WAQUA/DCSMv5 by evaluating the influence of a realistic air-sea momentum transfer parameterization and comparing it to the influence of changes in the spatial and temporal resolution of the applied forcing fields in an effort to support the improvement of impact and climate analysis studies. Particular attention is given to the representation of extreme water levels over the past decades based on the example of the Netherlands. For this, WAQUA/DCSMv5 is forced with ERA-Interim reanalysis data. Model results are obtained from a set of different forcing fields, which either (i) include a wave-state-dependent Charnock parameter or (ii) apply a constant Charnock parameter ( α C h = 0.032) tuned for young sea states in the North Sea, but differ in their spatial and/or temporal resolution. Increasing forcing field resolution from roughly 79 to 12 km through dynamically downscaling can reduce the modelled low bias, depending on coastal station, by up to 0.25 m for the modelled extreme water levels with a 1-year return period and between 0.1 m and 0.5 m for extreme surge heights.

Multifrequency Ultra-High Resolution Miniature Scanning Microscope Using Microchannel And Solid-State Sensor Technologies And Method For Scanning Samples

NASA Technical Reports Server (NTRS)

Wang, Yu (Inventor)

2006-01-01

A miniature, ultra-high resolution, and color scanning microscope using microchannel and solid-state technology that does not require focus adjustment. One embodiment includes a source of collimated radiant energy for illuminating a sample, a plurality of narrow angle filters comprising a microchannel structure to permit the passage of only unscattered radiant energy through the microchannels with some portion of the radiant energy entering the microchannels from the sample, a solid-state sensor array attached to the microchannel structure, the microchannels being aligned with an element of the solid-state sensor array, that portion of the radiant energy entering the microchannels parallel to the microchannel walls travels to the sensor element generating an electrical signal from which an image is reconstructed by an external device, and a moving element for movement of the microchannel structure relative to the sample. Discloses a method for scanning samples whereby the sensor array elements trace parallel paths that are arbitrarily close to the parallel paths traced by other elements of the array.

Structural investigations of Pu{sup III} phosphate by X-ray diffraction, MAS-NMR and XANES spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Popa, Karin; Raison, Philippe E., E-mail: philippe.raison@ec.europa.eu; Martel, Laura

2015-10-15

PuPO{sub 4} was prepared by a solid state reaction method and its crystal structure at room temperature was solved by powder X-ray diffraction combined with Rietveld refinement. High resolution XANES measurements confirm the +III valence state of plutonium, in agreement with valence bond derivation. The presence of the americium (as β{sup −} decay product of plutonium) in the +III oxidation state was determined based on XANES spectroscopy. High resolution solid state {sup 31}P NMR agrees with the XANES results and the presence of a solid-solution. - Graphical abstract: A full structural analysis of PuPO{sub 4} based on Rietveld analysis ofmore » room temperature X-ray diffraction data, XANES and MAS NMR measurements was performed. - Highlights: • The crystal structure of PuPO{sub 4} monazite is solved. • In PuPO{sub 4} plutonium is strictly trivalent. • The presence of a minute amount of Am{sup III} is highlighted. • We propose PuPO{sub 4} as a potential reference material for spectroscopic and microscopic studies.« less

Spatiotemporal source analysis in scalp EEG vs. intracerebral EEG and SPECT: a case study in a 2-year-old child.

PubMed

Aarabi, A; Grebe, R; Berquin, P; Bourel Ponchel, E; Jalin, C; Fohlen, M; Bulteau, C; Delalande, O; Gondry, C; Héberlé, C; Moullart, V; Wallois, F

2012-06-01

This case study aims to demonstrate that spatiotemporal spike discrimination and source analysis are effective to monitor the development of sources of epileptic activity in time and space. Therefore, they can provide clinically useful information allowing a better understanding of the pathophysiology of individual seizures with time- and space-resolved characteristics of successive epileptic states, including interictal, preictal, postictal, and ictal states. High spatial resolution scalp EEGs (HR-EEG) were acquired from a 2-year-old girl with refractory central epilepsy and single-focus seizures as confirmed by intracerebral EEG recordings and ictal single-photon emission computed tomography (SPECT). Evaluation of HR-EEG consists of the following three global steps: (1) creation of the initial head model, (2) automatic spike and seizure detection, and finally (3) source localization. During the source localization phase, epileptic states are determined to allow state-based spike detection and localization of underlying sources for each spike. In a final cluster analysis, localization results are integrated to determine the possible sources of epileptic activity. The results were compared with the cerebral locations identified by intracerebral EEG recordings and SPECT. The results obtained with this approach were concordant with those of MRI, SPECT and distribution of intracerebral potentials. Dipole cluster centres found for spikes in interictal, preictal, ictal and postictal states were situated an average of 6.3mm from the intracerebral contacts with the highest voltage. Both amplitude and shape of spikes change between states. Dispersion of the dipoles was higher in the preictal state than in the postictal state. Two clusters of spikes were identified. The centres of these clusters changed position periodically during the various epileptic states. High-resolution surface EEG evaluated by an advanced algorithmic approach can be used to investigate the spatiotemporal characteristics of sources located in the epileptic focus. The results were validated by standard methods, ensuring good spatial resolution by MRI and SPECT and optimal temporal resolution by intracerebral EEG. Surface EEG can be used to identify different spike clusters and sources of the successive epileptic states. The method that was used in this study will provide physicians with a better understanding of the pathophysiological characteristics of epileptic activities. In particular, this method may be useful for more effective positioning of implantable intracerebral electrodes. Copyright © 2011 Elsevier Masson SAS. All rights reserved.

Improving Numerical Weather Predictions of Summertime Precipitation Over the Southeastern U.S. Through a High-Resolution Initialization of the Surface State

NASA Technical Reports Server (NTRS)

Case, Jonathan L.; Kumar, Sujay V.; Krikishen, Jayanthi; Jedlovec, Gary J.

2011-01-01

It is hypothesized that high-resolution, accurate representations of surface properties such as soil moisture and sea surface temperature are necessary to improve simulations of summertime pulse-type convective precipitation in high resolution models. This paper presents model verification results of a case study period from June-August 2008 over the Southeastern U.S. using the Weather Research and Forecasting numerical weather prediction model. Experimental simulations initialized with high-resolution land surface fields from the NASA Land Information System (LIS) and sea surface temperature (SST) derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) are compared to a set of control simulations initialized with interpolated fields from the National Centers for Environmental Prediction 12-km North American Mesoscale model. The LIS land surface and MODIS SSTs provide a more detailed surface initialization at a resolution comparable to the 4-km model grid spacing. Soil moisture from the LIS spin-up run is shown to respond better to the extreme rainfall of Tropical Storm Fay in August 2008 over the Florida peninsula. The LIS has slightly lower errors and higher anomaly correlations in the top soil layer, but exhibits a stronger dry bias in the root zone. The model sensitivity to the alternative surface initial conditions is examined for a sample case, showing that the LIS/MODIS data substantially impact surface and boundary layer properties.

Resting-state functional connectivity imaging of the mouse brain using photoacoustic tomography

NASA Astrophysics Data System (ADS)

Nasiriavanaki, Mohammadreza; Xia, Jun; Wan, Hanlin; Bauer, Adam Q.; Culver, Joseph P.; Wang, Lihong V.

2014-03-01

Resting-state functional connectivity (RSFC) imaging is an emerging neuroimaging approach that aims to identify spontaneous cerebral hemodynamic fluctuations and their associated functional connections. Clinical studies have demonstrated that RSFC is altered in brain disorders such as stroke, Alzheimer's, autism, and epilepsy. However, conventional neuroimaging modalities cannot easily be applied to mice, the most widely used model species for human brain disease studies. For instance, functional magnetic resonance imaging (fMRI) of mice requires a very high magnetic field to obtain a sufficient signal-to-noise ratio and spatial resolution. Functional connectivity mapping with optical intrinsic signal imaging (fcOIS) is an alternative method. Due to the diffusion of light in tissue, the spatial resolution of fcOIS is limited, and experiments have been performed using an exposed skull preparation. In this study, we show for the first time, the use of photoacoustic computed tomography (PACT) to noninvasively image resting-state functional connectivity in the mouse brain, with a large field of view and a high spatial resolution. Bilateral correlations were observed in eight regions, as well as several subregions. These findings agreed well with the Paxinos mouse brain atlas. This study showed that PACT is a promising, non-invasive modality for small-animal functional brain imaging.

A high-resolution Godunov method for compressible multi-material flow on overlapping grids

NASA Astrophysics Data System (ADS)

Banks, J. W.; Schwendeman, D. W.; Kapila, A. K.; Henshaw, W. D.

2007-04-01

A numerical method is described for inviscid, compressible, multi-material flow in two space dimensions. The flow is governed by the multi-material Euler equations with a general mixture equation of state. Composite overlapping grids are used to handle complex flow geometry and block-structured adaptive mesh refinement (AMR) is used to locally increase grid resolution near shocks and material interfaces. The discretization of the governing equations is based on a high-resolution Godunov method, but includes an energy correction designed to suppress numerical errors that develop near a material interface for standard, conservative shock-capturing schemes. The energy correction is constructed based on a uniform-pressure-velocity flow and is significant only near the captured interface. A variety of two-material flows are presented to verify the accuracy of the numerical approach and to illustrate its use. These flows assume an equation of state for the mixture based on the Jones-Wilkins-Lee (JWL) forms for the components. This equation of state includes a mixture of ideal gases as a special case. Flow problems considered include unsteady one-dimensional shock-interface collision, steady interaction of a planar interface and an oblique shock, planar shock interaction with a collection of gas-filled cylindrical inhomogeneities, and the impulsive motion of the two-component mixture in a rigid cylindrical vessel.

Large laser projection displays utilizing all-solid-state RGB lasers

NASA Astrophysics Data System (ADS)

Xu, Zuyan; Bi, Yong

2005-01-01

RGB lasers projection displays have the advantages of producing large color triangle, high color saturation and high image resolution. In this report, with more than 4W white light synthesized by red (671nm), green (532nm) and blue (473nm) lasers, a RGB laser projection display system based on diode pumped solid-state lasers is developed and the performance of brilliant and vivid DVD dynamitic pictures on 60 inch screen is demonstrated.

In-depth evolution of chemical states and sub-10-nm-resolution crystal orientation mapping of nanograins in Ti(5 nm)/Au(20 nm)/Cr(3 nm) tri-layer thin films

NASA Astrophysics Data System (ADS)

Zhu, Xiaoli; Todeschini, Matteo; Bastos da Silva Fanta, Alice; Liu, Lintao; Jensen, Flemming; Hübner, Jörg; Jansen, Henri; Han, Anpan; Shi, Peixiong; Ming, Anjie; Xie, Changqing

2018-09-01

The applications of Au thin films and their adhesion layers often suffer from a lack of sufficient information about the chemical states of adhesion layers and about the high-lateral-resolution crystallographic morphology of Au nanograins. Here, we demonstrate the in-depth evolution of the chemical states of adhesive layers at the interfaces and the crystal orientation mapping of gold nanograins with a lateral resolution of less than 10 nm in a Ti/Au/Cr tri-layer thin film system. Using transmission electron microscopy, the variation in the interdiffusion at Cr/Au and Ti/Au interfaces was confirmed. From X-ray photoelectron spectroscopy (XPS) depth profiling, the chemical states of Cr, Au and Ti were characterized layer by layer, suggesting the insufficient oxidation of the adhesive layers. At the interfaces the Au 4f peaks shift to higher binding energies and this behavior can be described by a proposed model based on electron reorganization and substrate-induced final-state neutralization in small Au clusters supported by the partially oxidized Ti layer. Utilizing transmission Kikuchi diffraction (TKD) in a scanning electron microscope, the crystal orientation of Au nanograins between two adhesion layers was non-destructively characterized with sub-10 nm spatial resolution. The results provide nanoscale insights into the Ti/Au/Cr thin film system and contribute to our understanding of its behavior in nano-optic and nano-electronic devices.

Uses of continuum radiation in the AXAF calibration

NASA Technical Reports Server (NTRS)

Kolodziejczak, J. J.; Austin, R. A.; Elsner, R. F.; O'Dell, S. L.; Sulkanen, M. E.; Swartz, D. A.; Tennant, A. F.; Weisskopf, M. C.; Zirnstein, G.; McDermott, W. C.

1997-01-01

X-ray calibration of the Advanced X-ray Astrophysics Facility (AXAF) observatory at the MSFC X-Ray Calibration Facility (XRCF) made novel use of the x-ray continuum from a conventional electron-impact source. Taking advantage of the good spectral resolution of solid-state detectors, continuum measurements proved advantageous in calibrating the effective area of AXAF's High-Resolution Mirror Assembly (HRMA) and in verifying its alignment to the XRCF's optical axis.

Structure-from-motion for MAV image sequence analysis with photogrammetric applications

NASA Astrophysics Data System (ADS)

Schönberger, J. L.; Fraundorfer, F.; Frahm, J.-M.

2014-08-01

MAV systems have found increased attention in the photogrammetric community as an (autonomous) image acquisition platform for accurate 3D reconstruction. For an accurate reconstruction in feasible time, the acquired imagery requires specialized SfM software. Current systems typically use high-resolution sensors in pre-planned flight missions from far distance. We describe and evaluate a new SfM pipeline specifically designed for sequential, close-distance, and low-resolution imagery from mobile cameras with relatively high frame-rate and high overlap. Experiments demonstrate reduced computational complexity by leveraging the temporal consistency, comparable accuracy and point density with respect to state-of-the-art systems.

Application of Curved MPR Algorithm to High Resolution 3 Dimensional T2 Weighted CISS Images for Virtual Uncoiling of Membranous Cochlea as an Aid for Cochlear Morphometry.

PubMed

Kumar, Joish Upendra; Kavitha, Y

2017-02-01

With the use of various surgical techniques, types of implants, the preoperative assessment of cochlear dimensions is becoming increasingly relevant prior to cochlear implantation. High resolution CISS protocol MRI gives a better assessment of membranous cochlea, cochlear nerve, and membranous labyrinth. Curved Multiplanar Reconstruction (MPR) algorithm provides better images that can be used for measuring dimensions of membranous cochlea. To ascertain the value of curved multiplanar reconstruction algorithm in high resolution 3-Dimensional T2 Weighted Gradient Echo Constructive Interference Steady State (3D T2W GRE CISS) imaging for accurate morphometry of membranous cochlea. Fourteen children underwent MRI for inner ear assessment. High resolution 3D T2W GRE CISS sequence was used to obtain images of cochlea. Curved MPR reconstruction algorithm was used to virtually uncoil the membranous cochlea on the volume images and cochlear measurements were done. Virtually uncoiled images of membranous cochlea of appropriate resolution were obtained from the volume data obtained from the high resolution 3D T2W GRE CISS images, after using curved MPR reconstruction algorithm mean membranous cochlear length in the children was 27.52 mm. Maximum apical turn diameter of membranous cochlea was 1.13 mm, mid turn diameter was 1.38 mm, basal turn diameter was 1.81 mm. Curved MPR reconstruction algorithm applied to CISS protocol images facilitates in getting appropriate quality images of membranous cochlea for accurate measurements.

Efficient creation of electron vortex beams for high resolution STEM imaging.

PubMed

Béché, A; Juchtmans, R; Verbeeck, J

2017-07-01

The recent discovery of electron vortex beams carrying quantised angular momentum in the TEM has led to an active field of research, exploring a variety of potential applications including the possibility of mapping magnetic states at the atomic scale. A prerequisite for this is the availability of atomic sized electron vortex beams at high beam current and mode purity. In this paper we present recent progress showing that by making use of the Aharonov-Bohm effect near the tip of a long single domain ferromagnetic Nickel needle, a very efficient aperture for the production of electron vortex beams can be realised. The aperture transmits more than 99% of all electrons and provides a vortex mode purity of up to 92%. Placing this aperture in the condenser plane of a state of the art Cs corrected microscope allows us to demonstrate atomic resolution HAADF STEM images with spatial resolution better than 1 Angström, in agreement with theoretical expectations and only slightly inferior to the performance of a non-vortex probe on the same instrument. Copyright © 2016 Elsevier B.V. All rights reserved.

a Study of Vibrational Mode Coupling in 2-FLUOROETHANOL and 1,2-DIFLUOROETHANE Using High-Resolution Infrared Spectroscopy.

NASA Astrophysics Data System (ADS)

Mork, Steven Wayne

High resolution infrared spectroscopy was used to examine intramolecular vibrational interactions in 2 -fluoroethanol (2FE) and 1,2-difluoroethane (DFE). A high resolution infrared spectrophotometer capable of better than 10 MHz spectral resolution was designed and constructed. The excitation source consists of three lasers: an argon-ion pumped dye laser which pumps a color -center laser. The infrared beam from the color-center laser is used to excite sample molecules which are rotationally and vibrationally cooled in a supersonic molecular beam. Rovibrational excitation of the sample molecules is detected by monitoring the kinetic energy of the molecular beam with a bolometer. The high resolution infrared spectrum of 2FE was collected and analyzed over the 2977-2990 cm^ {-1}^ectral region. This region contains the asymmetric CH stretch on the fluorinated carbon. The spectrum revealed extensive perturbations in the rotational fine structure. Analysis of these perturbations has provided a quantitative measure of selective vibrational mode coupling between the C-H stretch and its many neighboring dark vibrational modes. Interestingly, excitation of the C-H stretch is known to induce a photoisomerization reaction between 2FE's Gg^' and Tt conformers. Implications of the role of mode coupling in the reaction mechanism are also addressed. Similarly, the high resolution infrared spectrum of DFE was collected and analyzed over the 2978-2996 cm ^{-1}^ectral region. This region contains the symmetric combination of asymmetric C-H stretches in DFE. Perturbations in the rotational fine structure indicate vibrational mode coupling to a single dark vibrational state. The dark state is split by approximately 19 cm^{-1} due to tunneling between two identical gauche conformers. The coupling mechanism is largely anharmonic with a minor component of B/C-plane Coriolis coupling. Effects of centrifugal distortion along the molecular A-axis are also observed. The coupled vibrational mode has been identified as containing C-C torsion, CCF bend and CH_2 rock. As in 2FE, DFE undergoes an isomerization reaction upon excitation of the C-H stretch. Coupling between the C-H stretch and C-C torsion is addressed with respect to the reaction mechanism.

Spectrocopic measurements of water vapor plasmas at high resolution: The optical transition probabilities for OH (A 2 Sigma - X 2 Pi)

NASA Technical Reports Server (NTRS)

Klein, L.

1972-01-01

Emission and absorption spectra of water vapor plasmas generated in a wall-stabilized arc at atmospheric pressure and 4 current, and at 0.03 atm and 15 to 50 A, were measured at high spatial and spectral resolution. The gas temperature was determined from the shape of Doppler-broadened rotational lines of OH. The observed nonequilibrium population distributions over the energy levels of atoms are interpreted in terms of a theoretical state model for diffusion-controlled arc plasmas. Excellent correlation is achieved between measured and predicted occupation of hydrogen energy levels. It is shown that the population distribution over the nonpredissociating rotational-vibrational levels of the A 2 Sigma state of OH is close to an equilibrium distribution at the gas temperature, although the total density of this state is much higher than its equilibrium density. The reduced intensities of the rotational lines originating in these levels yielded Boltzmann plots that were strictly linear.

DETECTING LOW-LEVEL SYNTHESIS IMPURITIES IN MODIFIED PHOSPHOROTHIOATE OLIGONUCLEOTIDES USING LIQUID CHROMATOGRAPHY – HIGH RESOLUTION MASS SPECTROMETRY

PubMed Central

Nikcevic, Irena; Wyrzykiewicz, Tadeusz K.; Limbach, Patrick A.

2010-01-01

Summary An LC-MS method based on the use of high resolution Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS) for profiling oligonucleotides synthesis impurities is described. Oligonucleotide phosphorothioatediesters (phosphorothioate oligonucleotides), in which one of the non-bridging oxygen atoms at each phosphorus center is replaced by a sulfur atom, are now one of the most popular oligonucleotide modifications due to their ease of chemical synthesis and advantageous pharmacokinetic properties. Despite significant progress in the solid-phase oligomerization chemistry used in the manufacturing of these oligonucleotides, multiple classes of low-level impurities always accompany synthetic oligonucleotides. Liquid chromatography-mass spectrometry has emerged as a powerful technique for the identification of these synthesis impurities. However, impurity profiling, where the entire complement of low-level synthetic impurities is identified in a single analysis, is more challenging. Here we present an LC-MS method based the use of high resolution-mass spectrometry, specifically Fourier transform ion cyclotron resonance mass spectrometry (FTIRCMS or FTMS). The optimal LC-FTMS conditions, including the stationary phase and mobile phases for the separation and identification of phosphorothioate oligonucleotides, were found. The characteristics of FTMS enable charge state determination from single m/z values of low-level impurities. Charge state information then enables more accurate modeling of the detected isotopic distribution for identification of the chemical composition of the detected impurity. Using this approach, a number of phosphorothioate impurities can be detected by LC-FTMS including failure sequences carrying 3′-terminal phosphate monoester and 3′-terminal phosphorothioate monoester, incomplete backbone sulfurization and desulfurization products, high molecular weight impurities, and chloral, isobutyryl, and N3 (2-cyanoethyl) adducts of the full length product. When compared with low resolution LC-MS, ~60% more impurities can be identified when charge state and isotopic distribution information is available and used for impurity profiling. PMID:21811394

Delayed gamma-ray spectroscopy with lanthanum bromide detector for non-destructive assay of nuclear material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Favalli, Andrea; Iliev, Metodi; Ianakiev, Kiril

High-energy delayed γ-ray spectroscopy is a potential technique for directly assaying spent fuel assemblies and achieving the safeguards goal of quantifying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Requirements for the γ-ray detection system, up to ~6 MeV, can be summarized as follows: high efficiency at high γ-ray energies, high energy resolution, good linearity between γ-ray energy and output signal amplitude, ability to operate at very high count rates, and ease of use in industrial environments such as nuclear facilities. High Purity Germanium Detectors (HPGe) are the state of the artmore » and provide excellent energy resolution but are limited in their count rate capability. Lanthanum Bromide (LaBr 3) scintillation detectors offer significantly higher count rate capabilities at lower energy resolution. Thus, LaBr 3 detectors may be an effective alternative for nuclear spent-fuel applications, where count-rate capability is a requirement. This paper documents the measured performance of a 2” (length) × 2” (diameter) of LaBr3 scintillation detector system, coupled to a negatively biased PMT and a tapered active high voltage divider, with count-rates up to ~3 Mcps. An experimental methodology was developed that uses the average current from the PMT’s anode and a dual source method to characterize the detector system at specific very high count rate values. Delayed γ-ray spectra were acquired with the LaBr 3 detector system at the Idaho Accelerator Center, Idaho State University, where samples of ~3g of 235U were irradiated with moderated neutrons from a photo-neutron source. Results of the spectroscopy characterization and analysis of the delayed γ-ray spectra acquired indicate the possible use of LaBr3 scintillation detectors when high count rate capability may outweigh the lower energy resolution.« less

Delayed gamma-ray spectroscopy with lanthanum bromide detector for non-destructive assay of nuclear material

DOE PAGES

Favalli, Andrea; Iliev, Metodi; Ianakiev, Kiril; ...

2017-10-09

High-energy delayed γ-ray spectroscopy is a potential technique for directly assaying spent fuel assemblies and achieving the safeguards goal of quantifying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Requirements for the γ-ray detection system, up to ~6 MeV, can be summarized as follows: high efficiency at high γ-ray energies, high energy resolution, good linearity between γ-ray energy and output signal amplitude, ability to operate at very high count rates, and ease of use in industrial environments such as nuclear facilities. High Purity Germanium Detectors (HPGe) are the state of the artmore » and provide excellent energy resolution but are limited in their count rate capability. Lanthanum Bromide (LaBr 3) scintillation detectors offer significantly higher count rate capabilities at lower energy resolution. Thus, LaBr 3 detectors may be an effective alternative for nuclear spent-fuel applications, where count-rate capability is a requirement. This paper documents the measured performance of a 2” (length) × 2” (diameter) of LaBr3 scintillation detector system, coupled to a negatively biased PMT and a tapered active high voltage divider, with count-rates up to ~3 Mcps. An experimental methodology was developed that uses the average current from the PMT’s anode and a dual source method to characterize the detector system at specific very high count rate values. Delayed γ-ray spectra were acquired with the LaBr 3 detector system at the Idaho Accelerator Center, Idaho State University, where samples of ~3g of 235U were irradiated with moderated neutrons from a photo-neutron source. Results of the spectroscopy characterization and analysis of the delayed γ-ray spectra acquired indicate the possible use of LaBr3 scintillation detectors when high count rate capability may outweigh the lower energy resolution.« less

Delayed gamma-ray spectroscopy with lanthanum bromide detector for non-destructive assay of nuclear material

NASA Astrophysics Data System (ADS)

Favalli, Andrea; Iliev, Metodi; Ianakiev, Kiril; Hunt, Alan W.; Ludewigt, Bernhard

2018-01-01

High-energy delayed γ-ray spectroscopy is a potential technique for directly assaying spent fuel assemblies and achieving the safeguards goal of quantifying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Requirements for the γ-ray detection system, up to ∼6 MeV, can be summarized as follows: high efficiency at high γ-ray energies, high energy resolution, good linearity between γ-ray energy and output signal amplitude, ability to operate at very high count rates, and ease of use in industrial environments such as nuclear facilities. High Purity Germanium Detectors (HPGe) are the state of the art and provide excellent energy resolution but are limited in their count rate capability. Lanthanum Bromide (LaBr3) scintillation detectors offer significantly higher count rate capabilities at lower energy resolution. Thus, LaBr3 detectors may be an effective alternative for nuclear spent-fuel applications, where count-rate capability is a requirement. This paper documents the measured performance of a 2" (length) × 2" (diameter) of LaBr3 scintillation detector system, coupled to a negatively biased PMT and a tapered active high voltage divider, with count-rates up to ∼3 Mcps. An experimental methodology was developed that uses the average current from the PMT's anode and a dual source method to characterize the detector system at specific very high count rate values. Delayed γ-ray spectra were acquired with the LaBr3 detector system at the Idaho Accelerator Center, Idaho State University, where samples of ∼3g of 235U were irradiated with moderated neutrons from a photo-neutron source. Results of the spectroscopy characterization and analysis of the delayed γ-ray spectra acquired indicate the possible use of LaBr3 scintillation detectors when high count rate capability may outweigh the lower energy resolution.

Resolution dependence of precipitation statistical fidelity in hindcast simulations

DOE PAGES

O'Brien, Travis A.; Collins, William D.; Kashinath, Karthik; ...

2016-06-19

This article is a U.S. Government work and is in the public domain in the USA. Numerous studies have shown that atmospheric models with high horizontal resolution better represent the physics and statistics of precipitation in climate models. While it is abundantly clear from these studies that high-resolution increases the rate of extreme precipitation, it is not clear whether these added extreme events are “realistic”; whether they occur in simulations in response to the same forcings that drive similar events in reality. In order to understand whether increasing horizontal resolution results in improved model fidelity, a hindcast-based, multiresolution experimental designmore » has been conceived and implemented: the InitiaLIzed-ensemble, Analyze, and Develop (ILIAD) framework. The ILIAD framework allows direct comparison between observed and simulated weather events across multiple resolutions and assessment of the degree to which increased resolution improves the fidelity of extremes. Analysis of 5 years of daily 5 day hindcasts with the Community Earth System Model at horizontal resolutions of 220, 110, and 28 km shows that: (1) these hindcasts reproduce the resolution-dependent increase of extreme precipitation that has been identified in longer-duration simulations, (2) the correspondence between simulated and observed extreme precipitation improves as resolution increases; and (3) this increase in extremes and precipitation fidelity comes entirely from resolved-scale precipitation. Evidence is presented that this resolution-dependent increase in precipitation intensity can be explained by the theory of Rauscher et al. (), which states that precipitation intensifies at high resolution due to an interaction between the emergent scaling (spectral) properties of the wind field and the constraint of fluid continuity.« less

Resolution dependence of precipitation statistical fidelity in hindcast simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

O'Brien, Travis A.; Collins, William D.; Kashinath, Karthik

This article is a U.S. Government work and is in the public domain in the USA. Numerous studies have shown that atmospheric models with high horizontal resolution better represent the physics and statistics of precipitation in climate models. While it is abundantly clear from these studies that high-resolution increases the rate of extreme precipitation, it is not clear whether these added extreme events are “realistic”; whether they occur in simulations in response to the same forcings that drive similar events in reality. In order to understand whether increasing horizontal resolution results in improved model fidelity, a hindcast-based, multiresolution experimental designmore » has been conceived and implemented: the InitiaLIzed-ensemble, Analyze, and Develop (ILIAD) framework. The ILIAD framework allows direct comparison between observed and simulated weather events across multiple resolutions and assessment of the degree to which increased resolution improves the fidelity of extremes. Analysis of 5 years of daily 5 day hindcasts with the Community Earth System Model at horizontal resolutions of 220, 110, and 28 km shows that: (1) these hindcasts reproduce the resolution-dependent increase of extreme precipitation that has been identified in longer-duration simulations, (2) the correspondence between simulated and observed extreme precipitation improves as resolution increases; and (3) this increase in extremes and precipitation fidelity comes entirely from resolved-scale precipitation. Evidence is presented that this resolution-dependent increase in precipitation intensity can be explained by the theory of Rauscher et al. (), which states that precipitation intensifies at high resolution due to an interaction between the emergent scaling (spectral) properties of the wind field and the constraint of fluid continuity.« less

Fusing Unmanned Aerial Vehicle Imagery with High Resolution Hydrologic Modeling (Invited)

NASA Astrophysics Data System (ADS)

Vivoni, E. R.; Pierini, N.; Schreiner-McGraw, A.; Anderson, C.; Saripalli, S.; Rango, A.

2013-12-01

After decades of development and applications, high resolution hydrologic models are now common tools in research and increasingly used in practice. More recently, high resolution imagery from unmanned aerial vehicles (UAVs) that provide information on land surface properties have become available for civilian applications. Fusing the two approaches promises to significantly advance the state-of-the-art in terms of hydrologic modeling capabilities. This combination will also challenge assumptions on model processes, parameterizations and scale as land surface characteristics (~0.1 to 1 m) may now surpass traditional model resolutions (~10 to 100 m). Ultimately, predictions from high resolution hydrologic models need to be consistent with the observational data that can be collected from UAVs. This talk will describe our efforts to develop, utilize and test the impact of UAV-derived topographic and vegetation fields on the simulation of two small watersheds in the Sonoran and Chihuahuan Deserts at the Santa Rita Experimental Range (Green Valley, AZ) and the Jornada Experimental Range (Las Cruces, NM). High resolution digital terrain models, image orthomosaics and vegetation species classification were obtained from a fixed wing airplane and a rotary wing helicopter, and compared to coarser analyses and products, including Light Detection and Ranging (LiDAR). We focus the discussion on the relative improvements achieved with UAV-derived fields in terms of terrain-hydrologic-vegetation analyses and summer season simulations using the TIN-based Real-time Integrated Basin Simulator (tRIBS) model. Model simulations are evaluated at each site with respect to a high-resolution sensor network consisting of six rain gauges, forty soil moisture and temperature profiles, four channel runoff flumes, a cosmic-ray soil moisture sensor and an eddy covariance tower over multiple summer periods. We also discuss prospects for the fusion of high resolution models with novel observations from UAVs, including synthetic aperture radar and multispectral imagery.

Exploring image data assimilation in the prospect of high-resolution satellite oceanic observations

NASA Astrophysics Data System (ADS)

Durán Moro, Marina; Brankart, Jean-Michel; Brasseur, Pierre; Verron, Jacques

2017-07-01

Satellite sensors increasingly provide high-resolution (HR) observations of the ocean. They supply observations of sea surface height (SSH) and of tracers of the dynamics such as sea surface salinity (SSS) and sea surface temperature (SST). In particular, the Surface Water Ocean Topography (SWOT) mission will provide measurements of the surface ocean topography at very high-resolution (HR) delivering unprecedented information on the meso-scale and submeso-scale dynamics. This study investigates the feasibility to use these measurements to reconstruct meso-scale features simulated by numerical models, in particular on the vertical dimension. A methodology to reconstruct three-dimensional (3D) multivariate meso-scale scenes is developed by using a HR numerical model of the Solomon Sea region. An inverse problem is defined in the framework of a twin experiment where synthetic observations are used. A true state is chosen among the 3D multivariate states which is considered as a reference state. In order to correct a first guess of this true state, a two-step analysis is carried out. A probability distribution of the first guess is defined and updated at each step of the analysis: (i) the first step applies the analysis scheme of a reduced-order Kalman filter to update the first guess probability distribution using SSH observation; (ii) the second step minimizes a cost function using observations of HR image structure and a new probability distribution is estimated. The analysis is extended to the vertical dimension using 3D multivariate empirical orthogonal functions (EOFs) and the probabilistic approach allows the update of the probability distribution through the two-step analysis. Experiments show that the proposed technique succeeds in correcting a multivariate state using meso-scale and submeso-scale information contained in HR SSH and image structure observations. It also demonstrates how the surface information can be used to reconstruct the ocean state below the surface.

High-energy-resolution monochromator for nuclear resonant scattering of synchrotron radiation by Te-125 at 35.49 keV

NASA Astrophysics Data System (ADS)

Imai, Yasuhiko; Yoda, Yoshitaka; Kitao, Shinji; Masuda, Ryo; Higashitaniguchi, Satoshi; Inaba, Chika; Seto, Makoto

2007-09-01

We have developed a high-resolution monochromator (HRM) for the measurement of nuclear resonant scattering (NRS) of synchrotron radiation by Te-125 at 35.49 keV using the backscattering of sapphire (9 1 -10 68). HRMs for nuclei with excitation energies less than 30 keV have been successfully developed using high angle diffractions by silicon crystals. Nearly perfect silicon crystal, however, is not suitable for high efficient HRMs at higher energy regions because the symmetry of the crystal structure is high and the Debye-temperature is low. Therefore, we used high quality synthetic sapphire crystal, which has low symmetry of crystal structure and high Debye-temperature. The temperature of the crystal was precisely controlled around 218 K to diffract synchrotron radiation with a Bragg angle of π/2 - 0.52 mrad. Energy was tuned by changing the crystal temperature under the condition of constant diffraction angle. Energy resolution was measured by detecting nuclear forward scattering by Te-125 in enriched TeO II. The relative energy resolution of 2.1×10 -7 is achieved, that is 7.5 meV in energy bandwidth. This HRM opens studies on element-specific dynamics and electronic state of substances containing Te-125.

Cr{sub 2}O{sub 5} as new cathode for rechargeable sodium ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Xu-Yong; Chien, Po-Hsiu; Rose, Alyssa M.

2016-10-15

Chromium oxide, Cr{sub 2}O{sub 5}, was synthesized by pyrolyzing CrO{sub 3} at 350 °C and employed as a new cathode in rechargeable sodium ion batteries. Cr{sub 2}O{sub 5}/Na rechargeable batteries delivered high specific capacities up to 310 mAh/g at a current density of C/16 (or 20 mA/g). High-resolution solid-state {sup 23}Na NMR both qualitatively and quantitatively revealed the reversible intercalation of Na ions into the bulk electrode and participation of Na ions in the formation of the solid-electrolyte interphase largely at low potentials. Amorphization of the electrode structure occurred during the first discharge revealed by both NMR and X-ray diffractionmore » data. CrO{sub 3}-catalyzed electrolyte degradation and loss in electronic conductivity led to gradual capacity fading. The specific capacity stabilized at >120 mAh/g after 50 charge-discharge cycles. Further improvement in electrochemical performance is possible via electrode surface modification, polymer binder incorporation, or designs of new morphologies. - Graphical abstract: Electrochemical profile of a Cr{sub 2}O{sub 5}/Na battery cell and high-resolution solid-state {sup 23}Na MAS NMR spectrum of a Cr{sub 2}O{sub 5} electrode discharged to 2 V. - Highlights: • Cr{sub 2}O{sub 5} was synthesized and used as a new cathode in rechargeable Na ion batteries. • A high capacity of 310 mAh/g and an energy density of 564 Wh/kg were achieved. • High-resolution solid-state {sup 23}Na NMR was employed to follow the reaction mechanisms.« less

All-passive pixel super-resolution of time-stretch imaging

PubMed Central

Chan, Antony C. S.; Ng, Ho-Cheung; Bogaraju, Sharat C. V.; So, Hayden K. H.; Lam, Edmund Y.; Tsia, Kevin K.

2017-01-01

Based on image encoding in a serial-temporal format, optical time-stretch imaging entails a stringent requirement of state-of-the-art fast data acquisition unit in order to preserve high image resolution at an ultrahigh frame rate — hampering the widespread utilities of such technology. Here, we propose a pixel super-resolution (pixel-SR) technique tailored for time-stretch imaging that preserves pixel resolution at a relaxed sampling rate. It harnesses the subpixel shifts between image frames inherently introduced by asynchronous digital sampling of the continuous time-stretch imaging process. Precise pixel registration is thus accomplished without any active opto-mechanical subpixel-shift control or other additional hardware. Here, we present the experimental pixel-SR image reconstruction pipeline that restores high-resolution time-stretch images of microparticles and biological cells (phytoplankton) at a relaxed sampling rate (≈2–5 GSa/s)—more than four times lower than the originally required readout rate (20 GSa/s) — is thus effective for high-throughput label-free, morphology-based cellular classification down to single-cell precision. Upon integration with the high-throughput image processing technology, this pixel-SR time-stretch imaging technique represents a cost-effective and practical solution for large scale cell-based phenotypic screening in biomedical diagnosis and machine vision for quality control in manufacturing. PMID:28303936

Land cover mapping and change detection in urban watersheds using QuickBird high spatial resolution satellite imagery

NASA Astrophysics Data System (ADS)

Hester, David Barry

The objective of this research was to develop methods for urban land cover analysis using QuickBird high spatial resolution satellite imagery. Such imagery has emerged as a rich commercially available remote sensing data source and has enjoyed high-profile broadcast news media and Internet applications, but methods of quantitative analysis have not been thoroughly explored. The research described here consists of three studies focused on the use of pan-sharpened 61-cm spatial resolution QuickBird imagery, the spatial resolution of which is the highest of any commercial satellite. In the first study, a per-pixel land cover classification method is developed for use with this imagery. This method utilizes a per-pixel classification approach to generate an accurate six-category high spatial resolution land cover map of a developing suburban area. The primary objective of the second study was to develop an accurate land cover change detection method for use with QuickBird land cover products. This work presents an efficient fuzzy framework for transforming map uncertainty into accurate and meaningful high spatial resolution land cover change analysis. The third study described here is an urban planning application of the high spatial resolution QuickBird-based land cover product developed in the first study. This work both meaningfully connects this exciting new data source to urban watershed management and makes an important empirical contribution to the study of suburban watersheds. Its analysis of residential roads and driveways as well as retail parking lots sheds valuable light on the impact of transportation-related land use on the suburban landscape. Broadly, these studies provide new methods for using state-of-the-art remote sensing data to inform land cover analysis and urban planning. These methods are widely adaptable and produce land cover products that are both meaningful and accurate. As additional high spatial resolution satellites are launched and the cost of high resolution imagery continues to decline, this research makes an important contribution to this exciting era in the science of remote sensing.

Diagnosing Cloud Biases in the GFDL AM3 Model With Atmospheric Classification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, Stuart; Marchand, Roger; Ackerman, Thomas

In this paper, we define a set of 21 atmospheric states, or recurring weather patterns, for a region surrounding the Atmospheric Radiation Measurement Program's Southern Great Plains site using an iterative clustering technique. The states are defined using dynamic and thermodynamic variables from reanalysis, tested for statistical significance with cloud radar data from the Southern Great Plains site, and are determined every 6 h for 14 years, creating a time series of atmospheric state. The states represent the various stages of the progression of synoptic systems through the region (e.g., warm fronts, warm sectors, cold fronts, cold northerly advection, andmore » high-pressure anticyclones) with a subset of states representing summertime conditions with varying degrees of convective activity. We use the states to classify output from the NOAA/Geophysical Fluid Dynamics Laboratory AM3 model to test the model's simulation of the frequency of occurrence of the states and of the cloud occurrence during each state. The model roughly simulates the frequency of occurrence of the states but exhibits systematic cloud occurrence biases. Comparison of observed and model-simulated International Satellite Cloud Climatology Project histograms of cloud top pressure and optical thickness shows that the model lacks high thin cloud under all conditions, but biases in thick cloud are state-dependent. Frontal conditions in the model do not produce enough thick cloud, while fair-weather conditions produce too much. Finally, we find that increasing the horizontal resolution of the model improves the representation of thick clouds under all conditions but has little effect on high thin clouds. However, increasing resolution also changes the distribution of states, causing an increase in total cloud occurrence bias.« less

Diagnosing Cloud Biases in the GFDL AM3 Model With Atmospheric Classification

NASA Astrophysics Data System (ADS)

Evans, Stuart; Marchand, Roger; Ackerman, Thomas; Donner, Leo; Golaz, Jean-Christophe; Seman, Charles

2017-12-01

We define a set of 21 atmospheric states, or recurring weather patterns, for a region surrounding the Atmospheric Radiation Measurement Program's Southern Great Plains site using an iterative clustering technique. The states are defined using dynamic and thermodynamic variables from reanalysis, tested for statistical significance with cloud radar data from the Southern Great Plains site, and are determined every 6 h for 14 years, creating a time series of atmospheric state. The states represent the various stages of the progression of synoptic systems through the region (e.g., warm fronts, warm sectors, cold fronts, cold northerly advection, and high-pressure anticyclones) with a subset of states representing summertime conditions with varying degrees of convective activity. We use the states to classify output from the NOAA/Geophysical Fluid Dynamics Laboratory AM3 model to test the model's simulation of the frequency of occurrence of the states and of the cloud occurrence during each state. The model roughly simulates the frequency of occurrence of the states but exhibits systematic cloud occurrence biases. Comparison of observed and model-simulated International Satellite Cloud Climatology Project histograms of cloud top pressure and optical thickness shows that the model lacks high thin cloud under all conditions, but biases in thick cloud are state-dependent. Frontal conditions in the model do not produce enough thick cloud, while fair-weather conditions produce too much. We find that increasing the horizontal resolution of the model improves the representation of thick clouds under all conditions but has little effect on high thin clouds. However, increasing resolution also changes the distribution of states, causing an increase in total cloud occurrence bias.

Diagnosing Cloud Biases in the GFDL AM3 Model With Atmospheric Classification

DOE PAGES

Evans, Stuart; Marchand, Roger; Ackerman, Thomas; ...

2017-11-16

In this paper, we define a set of 21 atmospheric states, or recurring weather patterns, for a region surrounding the Atmospheric Radiation Measurement Program's Southern Great Plains site using an iterative clustering technique. The states are defined using dynamic and thermodynamic variables from reanalysis, tested for statistical significance with cloud radar data from the Southern Great Plains site, and are determined every 6 h for 14 years, creating a time series of atmospheric state. The states represent the various stages of the progression of synoptic systems through the region (e.g., warm fronts, warm sectors, cold fronts, cold northerly advection, andmore » high-pressure anticyclones) with a subset of states representing summertime conditions with varying degrees of convective activity. We use the states to classify output from the NOAA/Geophysical Fluid Dynamics Laboratory AM3 model to test the model's simulation of the frequency of occurrence of the states and of the cloud occurrence during each state. The model roughly simulates the frequency of occurrence of the states but exhibits systematic cloud occurrence biases. Comparison of observed and model-simulated International Satellite Cloud Climatology Project histograms of cloud top pressure and optical thickness shows that the model lacks high thin cloud under all conditions, but biases in thick cloud are state-dependent. Frontal conditions in the model do not produce enough thick cloud, while fair-weather conditions produce too much. Finally, we find that increasing the horizontal resolution of the model improves the representation of thick clouds under all conditions but has little effect on high thin clouds. However, increasing resolution also changes the distribution of states, causing an increase in total cloud occurrence bias.« less

High Resolution Evaporative Fluxes Over Corn and Soybean Crops from Lidar

NASA Astrophysics Data System (ADS)

Eichinger, W. E.; Cooper, D. I.; Hipps, L. E.; Kustas, W. P.; Neale, C. M.; Prueger, J. H.

2003-12-01

The Soil Moisture-Atmosphere Coupling Experiment (SMACEX) was conducted in the Walnut Creek Watershed near Ames, Iowa over the period from June 15-July 11, 2002. A main focus of SMACEX was the investigation of the interactions between the atmospheric boundary layer, surface moisture and current vegetative state. The Lidar collected data over fields of soybeans and corn, with mutually supporting measurements by the NRC Twin Otter atmospheric research aircraft, the Utah State University Piper Seneca remote sensing aircraft, two elastic Lidars, and an array of eddy covariance towers in the nearby fields. The aircraft and lidar will provide a high resolution mapping of the evaporation rate over the fields and the changes between them. A mapping of the evaporative fluxes that existed during the field campaign, with a comparison to the topology of the local area will be presented.

A theoretical and experimental benchmark study of core-excited states in nitrogen

DOE PAGES

Myhre, Rolf H.; Wolf, Thomas J. A.; Cheng, Lan; ...

2018-02-14

The high resolution near edge X-ray absorption fine structure spectrum of nitrogen displays the vibrational structure of the core-excited states. This makes nitrogen well suited for assessing the accuracy of different electronic structure methods for core excitations. We report high resolution experimental measurements performed at the SOLEIL synchrotron facility. These are compared with theoretical spectra calculated using coupled cluster theory and algebraic diagrammatic construction theory. The coupled cluster singles and doubles with perturbative triples model known as CC3 is shown to accurately reproduce the experimental excitation energies as well as the spacing of the vibrational transitions. In conclusion, the computationalmore » results are also shown to be systematically improved within the coupled cluster hierarchy, with the coupled cluster singles, doubles, triples, and quadruples method faithfully reproducing the experimental vibrational structure.« less

Technical challenges for the future of high energy lasers

NASA Astrophysics Data System (ADS)

LaFortune, K. N.; Hurd, R. L.; Fochs, S. N.; Rotter, M. D.; Pax, P. H.; Combs, R. L.; Olivier, S. S.; Brase, J. M.; Yamamoto, R. M.

2007-02-01

The Solid-State, Heat-Capacity Laser (SSHCL) program at Lawrence Livermore National Laboratory is a multi-generation laser development effort scalable to the megawatt power levels with current performance approaching 100 kilowatts. This program is one of many designed to harness the power of lasers for use as directed energy weapons. There are many hurdles common to all of these programs that must be overcome to make the technology viable. There will be a in-depth discussion of the general issues facing state-of-the-art high energy lasers and paths to their resolution. Despite the relative simplicity of the SSHCL design, many challenges have been uncovered in the implementation of this particular system. An overview of these and their resolution are discussed. The overall system design of the SSHCL, technological strengths and weaknesses, and most recent experimental results will be presented.

A theoretical and experimental benchmark study of core-excited states in nitrogen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Myhre, Rolf H.; Wolf, Thomas J. A.; Cheng, Lan

The high resolution near edge X-ray absorption fine structure spectrum of nitrogen displays the vibrational structure of the core-excited states. This makes nitrogen well suited for assessing the accuracy of different electronic structure methods for core excitations. We report high resolution experimental measurements performed at the SOLEIL synchrotron facility. These are compared with theoretical spectra calculated using coupled cluster theory and algebraic diagrammatic construction theory. The coupled cluster singles and doubles with perturbative triples model known as CC3 is shown to accurately reproduce the experimental excitation energies as well as the spacing of the vibrational transitions. In conclusion, the computationalmore » results are also shown to be systematically improved within the coupled cluster hierarchy, with the coupled cluster singles, doubles, triples, and quadruples method faithfully reproducing the experimental vibrational structure.« less

Determination of lattice parameters, strain state and composition in semipolar III-nitrides using high resolution X-ray diffraction

NASA Astrophysics Data System (ADS)

Frentrup, Martin; Hatui, Nirupam; Wernicke, Tim; Stellmach, Joachim; Bhattacharya, Arnab; Kneissl, Michael

2013-12-01

In group-III-nitride heterostructures with semipolar or nonpolar crystal orientation, anisotropic lattice and thermal mismatch with the buffer or substrate lead to a complex distortion of the unit cells, e.g., by shearing of the lattice. This makes an accurate determination of lattice parameters, composition, and strain state under assumption of the hexagonal symmetry impossible. In this work, we present a procedure to accurately determine the lattice constants, strain state, and composition of semipolar heterostructures using high resolution X-ray diffraction. An analysis of the unit cell distortion shows that four independent lattice parameters are sufficient to describe this distortion. Assuming only small deviations from an ideal hexagonal structure, a linear expression for the interplanar distances dhkl is derived. It is used to determine the lattice parameters from high resolution X-ray diffraction 2ϑ-ω-scans of multiple on- and off-axis reflections via a weighted least-square fit. The strain and composition of ternary alloys are then evaluated by transforming the elastic parameters (using Hooke's law) from the natural crystal-fixed coordinate system to a layer-based system, given by the in-plane directions and the growth direction. We illustrate our procedure taking an example of (112¯2) AlκGa1-κN epilayers with Al-contents over the entire composition range. We separately identify the in-plane and out-of-plane strains and discuss origins for the observed anisotropy.

A Large-Scale, High-Resolution Hydrological Model Parameter Data Set for Climate Change Impact Assessment for the Conterminous US

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oubeidillah, Abdoul A; Kao, Shih-Chieh; Ashfaq, Moetasim

2014-01-01

To extend geographical coverage, refine spatial resolution, and improve modeling efficiency, a computation- and data-intensive effort was conducted to organize a comprehensive hydrologic dataset with post-calibrated model parameters for hydro-climate impact assessment. Several key inputs for hydrologic simulation including meteorologic forcings, soil, land class, vegetation, and elevation were collected from multiple best-available data sources and organized for 2107 hydrologic subbasins (8-digit hydrologic units, HUC8s) in the conterminous United States at refined 1/24 (~4 km) spatial resolution. Using high-performance computing for intensive model calibration, a high-resolution parameter dataset was prepared for the macro-scale Variable Infiltration Capacity (VIC) hydrologic model. The VICmore » simulation was driven by DAYMET daily meteorological forcing and was calibrated against USGS WaterWatch monthly runoff observations for each HUC8. The results showed that this new parameter dataset may help reasonably simulate runoff at most US HUC8 subbasins. Based on this exhaustive calibration effort, it is now possible to accurately estimate the resources required for further model improvement across the entire conterminous United States. We anticipate that through this hydrologic parameter dataset, the repeated effort of fundamental data processing can be lessened, so that research efforts can emphasize the more challenging task of assessing climate change impacts. The pre-organized model parameter dataset will be provided to interested parties to support further hydro-climate impact assessment.« less

Enhancing the resolution of 1H and 13C solid-state NMR spectra by reduction of anisotropic bulk magnetic susceptibility broadening.

PubMed

Hanrahan, Michael P; Venkatesh, Amrit; Carnahan, Scott L; Calahan, Julie L; Lubach, Joseph W; Munson, Eric J; Rossini, Aaron J

2017-10-25

We demonstrate that natural isotopic abundance 2D heteronuclear correlation (HETCOR) solid-state NMR spectra can be used to significantly reduce or eliminate the broadening of 1 H and 13 C solid-state NMR spectra of organic solids due to anisotropic bulk magnetic susceptibility (ABMS). ABMS often manifests in solids with aromatic groups, such as active pharmaceutical ingredients (APIs), and inhomogeneously broadens the NMR peaks of all nuclei in the sample. Inhomogeneous peaks with full widths at half maximum (FWHM) of ∼1 ppm typically result from ABMS broadening and the low spectral resolution impedes the analysis of solid-state NMR spectra. ABMS broadening of solid-state NMR spectra has previously been eliminated using 2D multiple-quantum correlation experiments, or by performing NMR experiments on diluted materials or single crystals. However, these experiments are often infeasible due to their poor sensitivity and/or provide limited gains in resolution. 2D 1 H- 13 C HETCOR experiments have previously been applied to reduce susceptibility broadening in paramagnetic solids and we show that this strategy can significantly reduce ABMS broadening in diamagnetic organic solids. Comparisons of 1D solid-state NMR spectra and 1 H and 13 C solid-state NMR spectra obtained from 2D 1 H- 13 C HETCOR NMR spectra show that the HETCOR spectrum directly increases resolution by a factor of 1.5 to 8. The direct gain in resolution is determined by the ratio of the inhomogeneous 13 C/ 1 H linewidth to the homogeneous 1 H linewidth, with the former depending on the magnitude of the ABMS broadening and the strength of the applied field and the latter on the efficiency of homonuclear decoupling. The direct gains in resolution obtained using the 2D HETCOR experiments are better than that obtained by dilution. For solids with long proton longitudinal relaxation times, dynamic nuclear polarization (DNP) was applied to enhance sensitivity and enable the acquisition of 2D 1 H- 13 C HETCOR NMR spectra. 2D 1 H- 13 C HETCOR experiments were applied to resolve and partially assign the NMR signals of the form I and form II polymorphs of aspirin in a sample containing both forms. These findings have important implications for ultra-high field NMR experiments, optimization of decoupling schemes and assessment of the fundamental limits on the resolution of solid-state NMR spectra.

Accretion disc wind variability in the states of the microquasar GRS 1915+105

NASA Astrophysics Data System (ADS)

Neilsen, Joseph; Petschek, Andrew J.; Lee, Julia C.

2012-03-01

Continuing our study of the role and evolution of accretion disc winds in the microquasar GRS 1915+105, we present high-resolution spectral variability analysis of the β and γ states with the Chandra High-Energy Transmission Grating Spectrometer. By tracking changes in the absorption lines from the accretion disc wind, we find new evidence that radiation links the inner and outer accretion discs on a range of time-scales. As the central X-ray flux rises during the high-luminosity γ state, we observe the progressive overionization of the wind. In the β state, we argue that changes in the inner disc leading to the ejection of a transient 'baby jet' also quench the highly ionized wind from the outer disc. Our analysis reveals how the state, structure and X-ray luminosity of the inner accretion disc all conspire to drive the formation and variability of highly ionized accretion disc winds.

Generation of High Resolution Land Surface Parameters in the Community Land Model

NASA Astrophysics Data System (ADS)

Ke, Y.; Coleman, A. M.; Wigmosta, M. S.; Leung, L.; Huang, M.; Li, H.

2010-12-01

The Community Land Model (CLM) is the land surface model used for the Community Atmosphere Model (CAM) and the Community Climate System Model (CCSM). It examines the physical, chemical, and biological processes across a variety of spatial and temporal scales. Currently, efforts are being made to improve the spatial resolution of the CLM, in part, to represent finer scale hydrologic characteristics. Current land surface parameters of CLM4.0, in particular plant functional types (PFT) and leaf area index (LAI), are generated from MODIS and calculated at a 0.05 degree resolution. These MODIS-derived land surface parameters have also been aggregated to coarser resolutions (e.g., 0.5, 1.0 degrees). To evaluate the response of CLM across various spatial scales, higher spatial resolution land surface parameters need to be generated. In this study we examine the use of Landsat TM/ETM+ imagery and data fusion techniques for generating land surface parameters at a 1km resolution within the Pacific Northwest United States. . Land cover types and PFTs are classified based on Landsat multi-season spectral information, DEM, National Land Cover Database (NLCD) and the USDA-NASS Crop Data Layer (CDL). For each PFT, relationships between MOD15A2 high quality LAI values, Landsat-based vegetation indices, climate variables, terrain, and laser-altimeter derived vegetation height are used to generate monthly LAI values at a 30m resolution. The high-resolution PFT and LAI data are aggregated to create a 1km model grid resolution. An evaluation and comparison of CLM land surface response at both fine and moderate scale is presented.

High-resolution mechanical imaging of the kidney.

PubMed

Streitberger, Kaspar-Josche; Guo, Jing; Tzschätzsch, Heiko; Hirsch, Sebastian; Fischer, Thomas; Braun, Jürgen; Sack, Ingolf

2014-02-07

The objective of this study was to test the feasibility and reproducibility of in vivo high-resolution mechanical imaging of the asymptomatic human kidney. Hereby nine volunteers were examined at three different physiological states of urinary bladder filling (a normal state, urinary urgency, and immediately after urinary relief). Mechanical imaging was performed of the in vivo kidney using three-dimensional multifrequency magnetic resonance elastography combined with multifrequency dual elastovisco inversion. Other than in classical elastography, where the storage and loss shear moduli are evaluated, we analyzed the magnitude |G(⁎)| and the phase angle φ of the complex shear modulus reconstructed by simultaneous inversion of full wave field data corresponding to 7 harmonic drive frequencies from 30 to 60Hz and a resolution of 2.5mm cubic voxel size. Mechanical parameter maps were derived with a spatial resolution superior to that in previous work. The group-averaged values of |G(⁎)| were 2.67±0.52kPa in the renal medulla, 1.64±0.17kPa in the cortex, and 1.17±0.21kPa in the hilus. The phase angle φ (in radians) was 0.89±0.12 in the medulla, 0.83±0.09 in the cortex, and 0.72±0.06 in the hilus. All regional differences were significant (P<0.001), while no significant variation was found in relation to different stages of bladder filling. In summary our study provides first high-resolution maps of viscoelastic parameters of the three anatomical regions of the kidney. |G(⁎)| and φ provide novel information on the viscoelastic properties of the kidney, which is potentially useful for the detection of renal lesions or fibrosis. © 2013 Published by Elsevier Ltd.

An Example-Based Super-Resolution Algorithm for Selfie Images

PubMed Central

William, Jino Hans; Venkateswaran, N.; Narayanan, Srinath; Ramachandran, Sandeep

2016-01-01

A selfie is typically a self-portrait captured using the front camera of a smartphone. Most state-of-the-art smartphones are equipped with a high-resolution (HR) rear camera and a low-resolution (LR) front camera. As selfies are captured by front camera with limited pixel resolution, the fine details in it are explicitly missed. This paper aims to improve the resolution of selfies by exploiting the fine details in HR images captured by rear camera using an example-based super-resolution (SR) algorithm. HR images captured by rear camera carry significant fine details and are used as an exemplar to train an optimal matrix-value regression (MVR) operator. The MVR operator serves as an image-pair priori which learns the correspondence between the LR-HR patch-pairs and is effectively used to super-resolve LR selfie images. The proposed MVR algorithm avoids vectorization of image patch-pairs and preserves image-level information during both learning and recovering process. The proposed algorithm is evaluated for its efficiency and effectiveness both qualitatively and quantitatively with other state-of-the-art SR algorithms. The results validate that the proposed algorithm is efficient as it requires less than 3 seconds to super-resolve LR selfie and is effective as it preserves sharp details without introducing any counterfeit fine details. PMID:27064500

Sensitivity of Hydrologic Extremes to Spatial Resolution of Meteorological Forcings: A Case Study of the Conterminous United States

NASA Astrophysics Data System (ADS)

Kao, S. C.; Naz, B. S.; Gangrade, S.; Ashfaq, M.; Rastogi, D.

2016-12-01

The magnitude and frequency of hydroclimate extremes are projected to increase in the conterminous United States (CONUS) with significant implications for future water resource planning and flood risk management. Nevertheless, apart from the change of natural environment, the choice of model spatial resolution could also artificially influence the features of simulated extremes. To better understand how the spatial resolution of meteorological forcings may affect hydroclimate projections, we test the runoff sensitivity using the Variable Infiltration Capacity (VIC) model that was calibrated for each CONUS 8-digit hydrologic unit (HUC8) at 1/24° ( 4km) grid resolution. The 1980-2012 gridded Daymet and PRISM meteorological observations are used to conduct the 1/24° resolution control simulation. Comparative simulations are achieved by smoothing the 1/24° forcing into 1/12° and 1/8° resolutions which are then used to drive the VIC model for the CONUS. In addition, we also test how the simulated high and low runoff conditions would react to change in precipitation (±10%) and temperature (+1°C). The results are further analyzed for various types of hydroclimate extremes across different watersheds in the CONUS. This work helps us understand the sensitivity of simulated runoff to different spatial resolutions of climate forcings and also its sensitivity to different watershed sizes and characteristics of extreme events in the future climate conditions.

Solid-state NMR adiabatic TOBSY sequences provide enhanced sensitivity for multidimensional high-resolution magic-angle-spinning 1H MR spectroscopy

NASA Astrophysics Data System (ADS)

Andronesi, Ovidiu C.; Mintzopoulos, Dionyssios; Struppe, Jochem; Black, Peter M.; Tzika, A. Aria

2008-08-01

We propose a solid-state NMR method that maximizes the advantages of high-resolution magic-angle-spinning (HRMAS) applied to intact biopsies when compared to more conventional liquid-state NMR approaches. Theoretical treatment, numerical simulations and experimental results on intact human brain biopsies are presented. Experimentally, it is proven that an optimized adiabatic TOBSY (TOtal through Bond correlation SpectroscopY) solid-state NMR pulse sequence for two-dimensional 1H- 1H homonuclear scalar-coupling longitudinal isotropic mixing provides a 20%-50% improvement in signal-to-noise ratio relative to its liquid-state analogue TOCSY (TOtal Correlation SpectroscopY). For this purpose we have refined the C9151 symmetry-based 13C TOBSY pulse sequence for 1H MRS use and compared it to MLEV-16 TOCSY sequence. Both sequences were rotor-synchronized and implemented using WURST-8 adiabatic inversion pulses. As discussed theoretically and shown in simulations, the improved magnetization-transfer comes from actively removing residual dipolar couplings from the average Hamiltonian. Importantly, the solid-state NMR techniques are tailored to perform measurements at low temperatures where sample degradation is reduced. This is the first demonstration of such a concept for HRMAS metabolic profiling of disease processes, including cancer, from biopsies requiring reduced sample degradation for further genomic analysis.

High resolution photoelectron imaging of UO(-) and UO2(-) and the low-lying electronic states and vibrational frequencies of UO and UO2.

PubMed

Czekner, Joseph; Lopez, Gary V; Wang, Lai-Sheng

2014-12-28

We report a study of the electronic and vibrational structures of the gaseous uranium monoxide and dioxide molecules using high-resolution photoelectron imaging. Vibrationally resolved photoelectron spectra are obtained for both UO(-) and UO2(-). The spectra for UO2(-) are consistent with, but much better resolved than a recent study using a magnetic-bottle photoelectron analyzer [W. L. Li et al., J. Chem. Phys. 140, 094306 (2014)]. The electron affinity (EA) of UO is reported for the first time as 1.1407(7) eV, whereas a much more accurate EA is obtained for UO2 as 1.1688(6) eV. The symmetric stretching modes for the neutral and anionic ground states, and two neutral excited states for UO2 are observed, as well as the bending mode for the neutral ground state. These vibrational frequencies are consistent with previous experimental and theoretical results. The stretching vibrational modes for the ground state and one excited state are observed for UO. The current results for UO and UO2 are compared with previous theoretical calculations including relativistic effects and spin-orbit coupling. The accurate experimental data reported here provide more stringent tests for future theoretical methods for actinide-containing species.

Airborne laser scanning for high-resolution mapping of Antarctica

NASA Astrophysics Data System (ADS)

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

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

Measuring Large-Scale Social Networks with High Resolution

PubMed Central

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

2014-01-01

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

Identifying species from the air: UAVs and the very high resolution challenge for plant conservation.

PubMed

Baena, Susana; Moat, Justin; Whaley, Oliver; Boyd, Doreen S

2017-01-01

The Pacific Equatorial dry forest of Northern Peru is recognised for its unique endemic biodiversity. Although highly threatened the forest provides livelihoods and ecosystem services to local communities. As agro-industrial expansion and climatic variation transform the region, close ecosystem monitoring is essential for viable adaptation strategies. UAVs offer an affordable alternative to satellites in obtaining both colour and near infrared imagery to meet the specific requirements of spatial and temporal resolution of a monitoring system. Combining this with their capacity to produce three dimensional models of the environment provides an invaluable tool for species level monitoring. Here we demonstrate that object-based image analysis of very high resolution UAV images can identify and quantify keystone tree species and their health across wide heterogeneous landscapes. The analysis exposes the state of the vegetation and serves as a baseline for monitoring and adaptive implementation of community based conservation and restoration in the area.

High Resolution Three-Dimensional MR Imaging of the Skull Base: Compartments, Boundaries, and Critical Structures.

PubMed

Blitz, Ari Meir; Aygun, Nafi; Herzka, Daniel A; Ishii, Masaru; Gallia, Gary L

2017-01-01

High-resolution 3D MRI of the skull base allows for a more detailed and accurate assessment of normal anatomic structures as well as the location and extent of skull base pathologies than has previously been possible. This article describes the techniques employed for high-resolution skull base MRI including pre- and post-contrast constructive interference in the steady state (CISS) imaging and their utility for evaluation of the many small structures of the skull base, focusing on those regions and concepts most pertinent to localization of cranial nerve palsies and in providing pre-operative guidance and post-operative assessment. The concept of skull base compartments as a means of conceptualizing the various layers of the skull base and their importance in assessment of masses of the skull base is discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Rapid mapping of polarization switching through complete information acquisition

NASA Astrophysics Data System (ADS)

Somnath, Suhas; Belianinov, Alex; Kalinin, Sergei V.; Jesse, Stephen

2016-12-01

Polarization switching in ferroelectric and multiferroic materials underpins a broad range of current and emergent applications, ranging from random access memories to field-effect transistors, and tunnelling devices. Switching in these materials is exquisitely sensitive to local defects and microstructure on the nanometre scale, necessitating spatially resolved high-resolution studies of these phenomena. Classical piezoresponse force microscopy and spectroscopy, although providing necessary spatial resolution, are fundamentally limited in data acquisition rates and energy resolution. This limitation stems from their two-tiered measurement protocol that combines slow (~1 s) switching and fast (~10 kHz-1 MHz) detection waveforms. Here we develop an approach for rapid probing of ferroelectric switching using direct strain detection of material response to probe bias. This approach, facilitated by high-sensitivity electronics and adaptive filtering, enables spectroscopic imaging at a rate 3,504 times faster the current state of the art, achieving high-veracity imaging of polarization dynamics in complex microstructures.

Three-dimensional localization of nanoscale battery reactions using soft X-ray tomography.

PubMed

Yu, Young-Sang; Farmand, Maryam; Kim, Chunjoong; Liu, Yijin; Grey, Clare P; Strobridge, Fiona C; Tyliszczak, Tolek; Celestre, Rich; Denes, Peter; Joseph, John; Krishnan, Harinarayan; Maia, Filipe R N C; Kilcoyne, A L David; Marchesini, Stefano; Leite, Talita Perciano Costa; Warwick, Tony; Padmore, Howard; Cabana, Jordi; Shapiro, David A

2018-03-02

Battery function is determined by the efficiency and reversibility of the electrochemical phase transformations at solid electrodes. The microscopic tools available to study the chemical states of matter with the required spatial resolution and chemical specificity are intrinsically limited when studying complex architectures by their reliance on two-dimensional projections of thick material. Here, we report the development of soft X-ray ptychographic tomography, which resolves chemical states in three dimensions at 11 nm spatial resolution. We study an ensemble of nano-plates of lithium iron phosphate extracted from a battery electrode at 50% state of charge. Using a set of nanoscale tomograms, we quantify the electrochemical state and resolve phase boundaries throughout the volume of individual nanoparticles. These observations reveal multiple reaction points, intra-particle heterogeneity, and size effects that highlight the importance of multi-dimensional analytical tools in providing novel insight to the design of the next generation of high-performance devices.

POLARIS: A 30-meter probabilistic soil series map of the contiguous United States

USGS Publications Warehouse

Chaney, Nathaniel W; Wood, Eric F; McBratney, Alexander B; Hempel, Jonathan W; Nauman, Travis; Brungard, Colby W.; Odgers, Nathan P

2016-01-01

A new complete map of soil series probabilities has been produced for the contiguous United States at a 30 m spatial resolution. This innovative database, named POLARIS, is constructed using available high-resolution geospatial environmental data and a state-of-the-art machine learning algorithm (DSMART-HPC) to remap the Soil Survey Geographic (SSURGO) database. This 9 billion grid cell database is possible using available high performance computing resources. POLARIS provides a spatially continuous, internally consistent, quantitative prediction of soil series. It offers potential solutions to the primary weaknesses in SSURGO: 1) unmapped areas are gap-filled using survey data from the surrounding regions, 2) the artificial discontinuities at political boundaries are removed, and 3) the use of high resolution environmental covariate data leads to a spatial disaggregation of the coarse polygons. The geospatial environmental covariates that have the largest role in assembling POLARIS over the contiguous United States (CONUS) are fine-scale (30 m) elevation data and coarse-scale (~ 2 km) estimates of the geographic distribution of uranium, thorium, and potassium. A preliminary validation of POLARIS using the NRCS National Soil Information System (NASIS) database shows variable performance over CONUS. In general, the best performance is obtained at grid cells where DSMART-HPC is most able to reduce the chance of misclassification. The important role of environmental covariates in limiting prediction uncertainty suggests including additional covariates is pivotal to improving POLARIS' accuracy. This database has the potential to improve the modeling of biogeochemical, water, and energy cycles in environmental models; enhance availability of data for precision agriculture; and assist hydrologic monitoring and forecasting to ensure food and water security.

A tool for rapid post-hurricane urban tree debris estimates using high resolution aerial imagery

Treesearch

Zoltan Szantoi; Sparkle L Malone; Francisco Escobedo; Orlando Misas; Scot Smith; Bon Dewitt

2012-01-01

Coastal communities in the southeast United States have regularly experienced severe hurricane impacts. To better facilitate recovery efforts in these communities following natural disasters, state and federal agencies must respond quickly with information regarding the extent and severity of hurricane damage and the amount of tree debris volume. A tool was developed...

Comparison of Ohm's Law Terms Using New High Resolution Fast Plasma Investigation Plasma Moments

NASA Astrophysics Data System (ADS)

Rager, A. C.; Dorelli, J.; Gershman, D. J.; Avanov, L. A.; Burch, J. L.; Ergun, R.; Giles, B. L.; Lavraud, B.; Moore, T. E.; Paterson, W. R.; Pollock, C.; Russell, C.; Saito, Y.; Sauvaud, J. A.; Schiff, C.; Strangeway, R. J.; Torbert, R. B.; Figueroa-Vinas, A.

2016-12-01

The Fast Plasma Investigation's Dual Spectrometers, DES and DIS, on the Magnetospheric Multiscale (MMS) mission measure all-sky images of charged particles every 30 and 150ms, respectively. The azimuthal resolution of each skymap results from biasing the electrostatic analyzers through four 11.25 degree deflection states. We present a technique of deconstructing the four deflection states of the FPI analyzers, allowing us to then reconstruct the phase space density with 4x faster, 7.5ms DES and 37.5ms DIS, time resolution at the expense of azimuthal resolution (in that only one fourth of the azimuths are covered). Nonetheless, we show that higher time resolution structure in the plasma moments is reliably recoverable. We validate the resulting 7.5ms DES velocities through the comparison of -vxB with the perpendicular electric field measured by the Electric Field Double Probe instrument and utilizing the Fluxgate Magnetometer instrument on MMS. Using this technique, we provide an unprecedented look at the terms in Ohm's law for several events, including the electron diffusion region event on 16 October, 2015 and a magnetopause crossing under northward interplanetary magnetic field on 25 November, 2015.

High-resolution vacuum-ultraviolet photoabsorption spectra of 1-butyne and 2-butyne

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacovella, U.; Holland, D. M. P.; Boyé-Péronne, S.

2015-07-21

The absolute photoabsorption cross sections of 1- and 2-butyne have been recorded at high resolution by using the vacuum-ultraviolet Fourier-Transform spectrometer at the SOLEIL Synchrotron. Both spectra show more resolved structure than previously observed, especially in the case of 2-butyne. In this work, we assess the potential importance of Rydberg states with higher values of orbital angular momentum, l, than are typically observed in photoabsorption experiments from ground state molecules. We show how the character of the highest occupied molecular orbitals in 1- and 2-butyne suggests the potential importance of transitions to such high-l (l = 3 and 4) Rydbergmore » states. Furthermore, we use theoretical calculations of the partial wave composition of the absorption cross section just above the ionization threshold and the principle of continuity of oscillator strength through an ionization threshold to support this conclusion. The new absolute photoabsorption cross sections are discussed in light of these arguments, and the results are consistent with the expectations. This type of argument should be valuable for assessing the potential importance of different Rydberg series when sufficiently accurate direct quantum chemical calculations are difficult, for example, in the n ≥ 5 manifolds of excited states of larger molecules.« less

A High Resolution Tropical Cyclone Power Outage Forecasting Model for the Continental United States

NASA Astrophysics Data System (ADS)

Pino, J. V.; Quiring, S. M.; Guikema, S.; Shashaani, S.; Linger, S.; Backhaus, S.

2017-12-01

Tropical cyclones cause extensive damage to the power infrastructure system throughout the United States. This damage can leave millions without power for extended periods of time, as most recently seen with Hurricane Matthew (2016). Accurate and timely prediction of power outages are essential for utility companies, emergency management agencies, and governmental organizations. Here we present a high-resolution (250 m x 250 m) hurricane power outage model for the United States. The model uses only publicly-available data to make predictions. It uses forecasts of storm variables such as maximum 3-second wind gust, duration of strong winds > 20 m s-2, soil moisture, and precipitation. It also incorporates static environmental variables such as elevation characteristics, land cover type, population density, tree species data, and root zone depth. A web tool was established for use by the Department of Energy (DOE) so that the model can be used for real-time outage forecasting or for synthetic tropical cyclones as an exercise in emergency management. This web tool provides DOE decision-makers with high impact analytic results and products that can be disseminated to federal, local, and state agencies. The results then aid utility companies in their pre- and post-storm activities, thus decreasing restoration times and lowering costs.

Subatomic and atomic crystallographic studies of aldose reductase: implications for inhibitor binding.

PubMed

Podjarny, A; Cachau, R E; Schneider, T; Van Zandt, M; Joachimiak, A

2004-04-01

The determination of several of aldose reductase-inhibitor complexes at subatomic resolution has revealed new structural details, including the specific interatomic contacts involved in inhibitor binding. In this article, we review the structures of the complexes of ALR2 with IDD 594 (resolution: 0.66 angstrom, IC50 (concentration of the inhibitor that produced half-maximal effect): 30 nM, space group: P2(1)), IDD 393 (resolution: 0.90 angstrom, IC50: 6 nM, space group: P1), fidarestat (resolution: 0.92 angstrom, IC50: 9 nM, space group: P2(1)) and minalrestat (resolution: 1.10 angstrom, IC50: 73 nM, space group: P1). The structures are compared and found to be highly reproductible within the same space group (root mean square (RMS) deviations: 0.15 approximately 0.3 angstrom). The mode of binding of the carboxylate inhibitors IDD 594 and IDD 393 is analysed. The binding of the carboxylate head can be accurately determined by the subatomic resolution structures, since both the protonation states and the positions of the atoms are very precisely known. The differences appear in the binding in the specificity pocket. The high-resolution structures explain the differences in IC50, which are confirmed both experimentally by mass spectrometry measures of VC50 and theoretically by free energy perturbation calculations. The binding of the cyclic imide inhibitors fidarestat and minalrestat is also described, focusing on the observation of a Cl(-) ion which binds simultaneously with fidarestat. The presence of this anion, binding also to the active site residue His110, leads to a mechanism in which the inhibitor can bind in a neutral state and then become charged inside the active site pocket. This mechanism can explain the excellent in vivo properties of cyclic imide inhibitors. In summary, the complete and detailed information supplied by the subatomic resolution structures can explain the differences in binding energy of the different inhibitors.

Small-displacement sensing system based on multiple total internal reflections in heterodyne interferometry.

PubMed

Wang, Shinn-Fwu; Chiu, Ming-Hung; Chen, Wei-Wu; Kao, Fu-Hsi; Chang, Rong-Seng

2009-05-01

A small-displacement sensing system based on multiple total internal reflections in heterodyne interferometry is proposed. In this paper, a small displacement can be obtained only by measuring the variation in phase difference between s- and p-polarization states for the total internal reflection effect. In order to improve the sensitivity, we increase the number of total internal reflections by using a parallelogram prism. The theoretical resolution of the method is better than 0.417 nm. The method has some merits, e.g., high resolution, high sensitivity, and real-time measurement. Also, its feasibility is demonstrated.

High-resolution X-ray spectroscopy of M87 with the Einstein observatory - The detection of an O VIII emission line

NASA Technical Reports Server (NTRS)

Canizares, C. R.; Clark, G. W.; Markert, T. H.; Berg, C.; Smedira, M.; Bardas, D.; Schnopper, H.; Kalata, K.

1979-01-01

The paper deals with high-resolution X-ray spectroscopy performed to study the extended source surrounding the giant elliptical galaxy, M87, in the Virgo cluster. From observations carried out with a focal plane crystal spectrometer, L-alpha emission was detected from hydrogenic oxygen (O VIII). Upper limits could be set on lines from intermediate ionization states of iron. The presence of a quantity of cooler matter surrounding M87 was revealed, which has important implications for cluster models and favors a radiatively controlled accretion mechanism.

State of the art in video system performance

NASA Technical Reports Server (NTRS)

Lewis, Michael J.

1990-01-01

The closed circuit television (CCTV) system that is onboard the Space Shuttle has the following capabilities: camera, video signal switching and routing unit (VSU); and Space Shuttle video tape recorder. However, this system is inadequate for use with many experiments that require video imaging. In order to assess the state-of-the-art in video technology and data storage systems, a survey was conducted of the High Resolution, High Frame Rate Video Technology (HHVT) products. The performance of the state-of-the-art solid state cameras and image sensors, video recording systems, data transmission devices, and data storage systems versus users' requirements are shown graphically.

Compressed Sensing for fMRI: Feasibility Study on the Acceleration of Non-EPI fMRI at 9.4T

PubMed Central

Kim, Seong-Gi; Ye, Jong Chul

2015-01-01

Conventional functional magnetic resonance imaging (fMRI) technique known as gradient-recalled echo (GRE) echo-planar imaging (EPI) is sensitive to image distortion and degradation caused by local magnetic field inhomogeneity at high magnetic fields. Non-EPI sequences such as spoiled gradient echo and balanced steady-state free precession (bSSFP) have been proposed as an alternative high-resolution fMRI technique; however, the temporal resolution of these sequences is lower than the typically used GRE-EPI fMRI. One potential approach to improve the temporal resolution is to use compressed sensing (CS). In this study, we tested the feasibility of k-t FOCUSS—one of the high performance CS algorithms for dynamic MRI—for non-EPI fMRI at 9.4T using the model of rat somatosensory stimulation. To optimize the performance of CS reconstruction, different sampling patterns and k-t FOCUSS variations were investigated. Experimental results show that an optimized k-t FOCUSS algorithm with acceleration by a factor of 4 works well for non-EPI fMRI at high field under various statistical criteria, which confirms that a combination of CS and a non-EPI sequence may be a good solution for high-resolution fMRI at high fields. PMID:26413503

Absorption, autoionization, and predissociation in molecular hydrogen: High-resolution spectroscopy and multichannel quantum defect theory.

PubMed

Sommavilla, M; Merkt, F; Mezei, J Zs; Jungen, Ch

2016-02-28

Absorption and photoionization spectra of H2 have been recorded at a resolution of 0.09 and 0.04 cm(-1), respectively, between 125,600 cm(-1) and 126,000 cm(-1). The observed Rydberg states belong to series (n = 10 - 14) converging on the first vibrationally excited level of the X (2)Σ(g)(+) state of H2(+), and of lower members of series converging on higher vibrational levels. The observed resonances are characterized by the competition between autoionization, predissociation, and fluorescence. The unprecedented resolution of the present experimental data leads to a full characterization of the predissociation/autoionization profiles of many resonances that had not been resolved previously. Multichannel quantum defect theory is used to predict the line positions, widths, shapes, and intensities of the observed spectra and is found to yield quantitative agreement using previously determined quantum defect functions as the unique set of input parameters.

NASA's Soil Moisture Active Passive (SMAP) Observatory

NASA Technical Reports Server (NTRS)

Kellogg, Kent; Thurman, Sam; Edelstein, Wendy; Spencer, Michael; Chen, Gun-Shing; Underwood, Mark; Njoku, Eni; Goodman, Shawn; Jai, Benhan

2013-01-01

The SMAP mission will produce high-resolution and accurate global maps of soil moisture and its freeze/thaw state using data from a non-imaging synthetic aperture radar and a radiometer, both operating at L-band.

NRL Fact Book

DTIC Science & Technology

1991-05-01

Bio/Molecular Science & Engineering High Resolution Patterning Program Manager Archaebacteria Research Program Manager ONT Receptor Based Biosensor...CMC) in discharging their responsibilities on matters of general scientific and technical interest to the United States in the United Kingdom , Europe

NREL: International Activities - Bhutan Resource Maps

Science.gov Websites

modeling approach along with NREL's empirical validation methodology. The high-resolution (10-km) annual -time specific solar mapping approach developed at the U.S. State University of New York at Albany. Data

Glue-Free Stacked Luminescent Nanosheets Enable High-Resolution Ratiometric Temperature Mapping in Living Small Animals.

PubMed

Miyagawa, Takuya; Fujie, Toshinori; Ferdinandus; Vo Doan, Tat Thang; Sato, Hirotaka; Takeoka, Shinji

2016-12-14

In this paper, a microthermograph, temperature mapping with high spatial resolution, was established using luminescent molecules embedded ultrathin polymeric films (nanosheets), and demonstrated in a living small animal to map out and visualize temperature shift due to animal's muscular activity. Herein, we report super flexible and self-adhesive (no need of glue) nanothermosensor consisting of stacked two different polymeric nanosheets with thermosensitive (Eu-tris (dinaphthoylmethane)-bis-trioctylphosphine oxide: EuDT) and insensitive (Rhodamine 800) dyes being embedded. Such stacked nanosheets allow for the ratiometric thermometry, with which the undesired luminescence intensity shift due to focal drift or animal's z-axis displacement is eliminated and the desired intensity shift solely due to the temperature shift of the sample (living muscle) can be acquired. With the stacked luminescent nanosheets, we achieved the first-ever demonstration of video filming of chronologically changing temperature-shift distribution from the rest state to the active state of the muscles in the living animal. The polymer nanosheet engineering and in vivo microthermography presented in the paper are promising technologies to microscopically explore the heat production and heat transfer in living cells, tissues, and organisms with high spatial resolution beyond what existing thermometric technologies such as infrared thermography have ever achieved.

Effect of AMOC collapse on ENSO in a high resolution general circulation model

NASA Astrophysics Data System (ADS)

Williamson, Mark S.; Collins, Mat; Drijfhout, Sybren S.; Kahana, Ron; Mecking, Jennifer V.; Lenton, Timothy M.

2018-04-01

We look at changes in the El Niño Southern Oscillation (ENSO) in a high-resolution eddy-permitting climate model experiment in which the Atlantic Meridional Circulation (AMOC) is switched off using freshwater hosing. The ENSO mode is shifted eastward and its period becomes longer and more regular when the AMOC is off. The eastward shift can be attributed to an anomalous eastern Ekman transport in the mean equatorial Pacific ocean state. Convergence of this transport deepens the thermocline in the eastern tropical Pacific and increases the temperature anomaly relaxation time, causing increased ENSO period. The anomalous Ekman transport is caused by a surface northerly wind anomaly in response to the meridional sea surface temperature dipole that results from switching the AMOC off. In contrast to a previous study with an earlier version of the model, which showed an increase in ENSO amplitude in an AMOC off experiment, here the amplitude remains the same as in the AMOC on control state. We attribute this difference to variations in the response of decreased stochastic forcing in the different models, which competes with the reduced damping of temperature anomalies. In the new high-resolution model, these effects approximately cancel resulting in no change in amplitude.

The Excitation of High Spin States with Quasielastic and Deep Inelastic Reactions.

NASA Astrophysics Data System (ADS)

Knott, Clinton Neal

1988-12-01

The feasibility of populating high spin states using reactions induced by a 220 MeV ^{22 }Ne beam on a ^{170} Er target was studied. The experiment was carried out using a multidetector array for high resolution gamma-ray spectroscopy, a 14 element sum multiplicity spectrometer and six DeltaE-E particle telescopes. Detailed information was obtained concerning the reaction mechanisms associated with various reaction channels. Deep inelastic collisions are shown to be a promising tool for high spin spectroscopy in regions of the chart of nuclides which are not accessible by other reactions.

Population of high spin states by quasi-elastic and deep inelastic collisions

NASA Astrophysics Data System (ADS)

Takai, H.; Knott, C. N.; Winchell, D. F.; Saladin, J. X.; Kaplan, M. S.; de Faro, L.; Aryaeinejad, R.; Blue, R. A.; Ronningen, R. M.; Morrissey, D. J.; Lee, I. Y.; Dietzsch, O.

1988-09-01

The feasibility of populating high spin states using reactions induced by a 10 MeV/nucleon 22Ne beam on 170Er was studied. The experiment was carried out using a multidetector array for high resolution γ-ray spectroscopy, a 14 element sum-multiplicity spectrometer and six ΔE-E telescopes. Detailed information was obtained concerning the reaction mechanisms associated with various reaction channels. Deep inelastic collisions are shown to be a promising tool for high spin spectroscopy in regions of the chart of nuclides which are not accessible by other reactions.

Micro-XANES Determination Fe Speciation in Natural Basalts at Mantle-Relevant fO2

NASA Astrophysics Data System (ADS)

Fischer, R.; Cottrell, E.; Lanzirotti, A.; Kelley, K. A.

2007-12-01

We demonstrate that the oxidation state of iron (Fe3+/ΣFe) can be determined with a precision of ±0.02 (10% relative) on natural basalt glasses at mantle-relevant fO2 using Fe K-edge X-ray absorption near edge structure (XANES) spectroscopy. This is equivalent to ±0.25 log unit resolution relative to the QFM buffer. Precise determination of the oxidation state over this narrow range (Fe3+/ΣFe=0.06-0.30) and at low fO2 (down to QFM-2) relies on appropriate standards, high spectral resolution, and highly reproducible methods for extracting the pre-edge centroid position. We equilibrated natural tholeiite powder in a CO/CO2 gas mixing furnace at 1350°C from QFM-3 to QFM+2 to create six glasses of known Fe3+/ΣFe, independently determined by Mössbauer spectroscopy. XANES spectra were collected at station X26A at NSLS, Brookhaven Natl. Lab, in fluorescence mode (9 element Ge array detector) using both Si(111) and Si(311) monochromators. Generally, the energy position of the 1s→3d (pre-edge) transition centroid is the most sensitive monitor of Fe oxidation state using XANES. For the mixture of Fe oxidation states in these glasses and the resulting coordination geometries, the pre-edge spectra are best defined by two multiple 3d crystal field transitions. The Si(311) monochromator, with higher energy resolution, substantially improved spectral resolution for the 1s→3d transition. Dwell times of 5s at 0.1eV intervals across the pre-edge region yielded spectra with the 1s→3d transition peaks clearly resolved. The pre-edge centroid position is highly sensitive to the background subtraction and peak fitting procedures. Differences in fitting models result in small but significant differences in the calculated peak area of each pre-edge multiplet, and the relative contribution of each peak to the calculated centroid. We assessed several schemes and obtained robust centroid positions by simultaneously fitting the background with a damped harmonic oscillator (DHO) function and pre-edge features with two Gaussians over a sub-sample of the pre-edge region (7110-7120 eV). We found that the relation between Fe3+/ΣFe and the centroid energy is non-linear over this fO2 range, which is expected if the coordination environment changes with oxidation state. ΔQFM is linearly related (R2=0.99) to the centroid position. This new calibration allows the oxidation states of natural mantle melts to be discriminated with high spatial resolution (9μm). We apply the new calibration to determination of Fe3+/ΣFe in natural basaltic glasses and olivine-hosted glass inclusions (Cottrell et al. & Kelley et al., this meeting).

Extracting biomolecule collision cross sections from the high-resolution FT-ICR mass spectral linewidths.

PubMed

Jiang, Ting; Chen, Yu; Mao, Lu; Marshall, Alan G; Xu, Wei

2016-01-14

It is known that the ion collision cross section (CCS) may be calculated from the linewidth of a Fourier transform ion cyclotron resonance (FT-ICR) mass spectral peak at elevated pressure (e.g., ∼10(-6) Torr). However, the high mass resolution of FT-ICR is sacrificed in those experiments due to high buffer gas pressure. In this study, we describe a linewidth correction method to eliminate the windowing-induced peak broadening effect. Together with the energetic ion-neutral collision model previously developed by our group, this method enables the extraction of CCSs of biomolecules from high-resolution FT-ICR mass spectral linewidths, obtained at a typical operating buffer gas pressure of modern FT-ICR instruments (∼10(-10) Torr). CCS values of peptides including MRFA, angiotensin I, and bradykinin measured by the proposed method agree well with ion mobility measurements, and the unfolding of protein ions (ubiquitin) at higher charge states is also observed.

TADIR-production version: El-Op's high-resolution 480x4 TDI thermal imaging system

NASA Astrophysics Data System (ADS)

Sarusi, Gabby; Ziv, Natan; Zioni, O.; Gaber, J.; Shechterman, Mark S.; Lerner, M.

1999-07-01

Efforts invested at El-Op during the last four years have led to the development of TADIR - engineering model thermal imager, demonstrated in 1998, and eventually to the final production version of TADIR to be demonstrated in full operation during 1999. Both versions take advantage of the high resolution and high sensitivity obtained by the 480 X 4 TDI MCT detector as well as many more features implemented in the system to obtain a state of the art high- end thermal imager. The production version of TADIR uses a 480 X 6 TDI HgCdTe detector made by the SCD Israeli company. In this paper, we will present the main features of the production version of TADIR.

High Resolution, High Frame Rate Video Technology

NASA Technical Reports Server (NTRS)

1990-01-01

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

Improving PET spatial resolution and detectability for prostate cancer imaging

NASA Astrophysics Data System (ADS)

Bal, H.; Guerin, L.; Casey, M. E.; Conti, M.; Eriksson, L.; Michel, C.; Fanti, S.; Pettinato, C.; Adler, S.; Choyke, P.

2014-08-01

Prostate cancer, one of the most common forms of cancer among men, can benefit from recent improvements in positron emission tomography (PET) technology. In particular, better spatial resolution, lower noise and higher detectability of small lesions could be greatly beneficial for early diagnosis and could provide a strong support for guiding biopsy and surgery. In this article, the impact of improved PET instrumentation with superior spatial resolution and high sensitivity are discussed, together with the latest development in PET technology: resolution recovery and time-of-flight reconstruction. Using simulated cancer lesions, inserted in clinical PET images obtained with conventional protocols, we show that visual identification of the lesions and detectability via numerical observers can already be improved using state of the art PET reconstruction methods. This was achieved using both resolution recovery and time-of-flight reconstruction, and a high resolution image with 2 mm pixel size. Channelized Hotelling numerical observers showed an increase in the area under the LROC curve from 0.52 to 0.58. In addition, a relationship between the simulated input activity and the area under the LROC curve showed that the minimum detectable activity was reduced by more than 23%.

Motion robust high resolution 3D free-breathing pulmonary MRI using dynamic 3D image self-navigator.

PubMed

Jiang, Wenwen; Ong, Frank; Johnson, Kevin M; Nagle, Scott K; Hope, Thomas A; Lustig, Michael; Larson, Peder E Z

2018-06-01

To achieve motion robust high resolution 3D free-breathing pulmonary MRI utilizing a novel dynamic 3D image navigator derived directly from imaging data. Five-minute free-breathing scans were acquired with a 3D ultrashort echo time (UTE) sequence with 1.25 mm isotropic resolution. From this data, dynamic 3D self-navigating images were reconstructed under locally low rank (LLR) constraints and used for motion compensation with one of two methods: a soft-gating technique to penalize the respiratory motion induced data inconsistency, and a respiratory motion-resolved technique to provide images of all respiratory motion states. Respiratory motion estimation derived from the proposed dynamic 3D self-navigator of 7.5 mm isotropic reconstruction resolution and a temporal resolution of 300 ms was successful for estimating complex respiratory motion patterns. This estimation improved image quality compared to respiratory belt and DC-based navigators. Respiratory motion compensation with soft-gating and respiratory motion-resolved techniques provided good image quality from highly undersampled data in volunteers and clinical patients. An optimized 3D UTE sequence combined with the proposed reconstruction methods can provide high-resolution motion robust pulmonary MRI. Feasibility was shown in patients who had irregular breathing patterns in which our approach could depict clinically relevant pulmonary pathologies. Magn Reson Med 79:2954-2967, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

Long-term, high-spatial resolution carbon balance monitoring of the Amazonian frontier: Predisturbance and postdisturbance carbon emissions and uptake

NASA Astrophysics Data System (ADS)

Toomey, Michael; Roberts, Dar A.; Caviglia-Harris, Jill; Cochrane, Mark A.; Dewes, Candida F.; Harris, Daniel; Numata, Izaya; Sales, Marcio H.; Sills, Erin; Souza, Carlos M.

2013-06-01

We performed high-spatial and high-temporal resolution modeling of carbon stocks and fluxes in the state of Rondônia, Brazil for the period 1985-2009, using annual Landsat-derived land cover classifications and a modified bookkeeping modeling approach. According to these results, Rondônia contributed 3.5-4% of pantropical humid forest deforestation emissions over this period. Similar to well-known figures reported by the Brazilian Space Agency, we found a decline in deforestation rates since 2006. However, we estimate a lesser decrease, with deforestation rates continuing at levels similar to the early 2000s. Forest carbon stocks declined at an annual rate of 1.51%; emissions from postdisturbance land use nearly equaled those of the initial deforestation events. Carbon uptake by secondary forest was negligible due to limited spatial extent and high turnover rates. Net carbon emissions represented 93% of initial forest carbon stocks, due in part to repeated slash and pasture burnings and secondary forest clearing. We analyzed potential error incurred when spatially aggregating land cover by comparing results based on coarser-resolution (250 m) and full-resolution land cover products. At the coarser resolution, more than 90% of deforestation and secondary forest would be unresolvable, assuming that a 50% change threshold is necessary for detection. Therefore, we strongly suggest the use of Landsat-scale ( 30m) resolution carbon monitoring in tropical regions dominated by nonmechanized, smallholder land use change.

Introduction and Testing of a Monitoring and Colony-Mapping Method for Waterbird Populations That Uses High-Speed and Ultra-Detailed Aerial Remote Sensing

PubMed Central

Bakó, Gábor; Tolnai, Márton; Takács, Ádám

2014-01-01

Remote sensing is a method that collects data of the Earth's surface without causing disturbances. Thus, it is worthwhile to use remote sensing methods to survey endangered ecosystems, as the studied species will behave naturally while undisturbed. The latest passive optical remote sensing solutions permit surveys from long distances. State-of-the-art highly sensitive sensor systems allow high spatial resolution image acquisition at high altitudes and at high flying speeds, even in low-visibility conditions. As the aerial imagery captured by an airplane covers the entire study area, all the animals present in that area can be recorded. A population assessment is conducted by visual interpretations of an ortho image map. The basic objective of this study is to determine whether small- and medium-sized bird species are recognizable in the ortho images by using high spatial resolution aerial cameras. The spatial resolution needed for identifying the bird species in the ortho image map was studied. The survey was adjusted to determine the number of birds in a colony at a given time. PMID:25046012

High-Resolution Topography and its Implications for the Formation of Europa's Ridged Plains

NASA Astrophysics Data System (ADS)

Leonard, E. J.; Pappalardo, R. T.; Yin, A.; Patthoff, D. A.; Schenk, P.

2015-12-01

The Galileo Solid State Imager (SSI) recorded nine very high-resolution frames—eight at 12 m/pixel and one at 6 m/pixel—during the E12 flyby of Europa in Dec. 1997. To understand the implications for the small-scale structure and evolution of Europa, we mosaicked these frames (observations 12ESMOTTLE01 and 02, incidence ≈18°, emission ≈77°) into their regional context (part of observation 11ESREGMAP01, 220 m/pixel, incidence ≈74°, emission ≈23°). The topography data, which was created from the image mosaic overlaps, is sparse and segmented over the high-resolution images but connected by the underlying regional resolution topography. The high-resolution topography (24 m/pixel) is among the best for the current Europan dataset. From this dataset we ascertain the root mean square, or RMS, slope for some of the most common Europan surface features in a new region. We also employ a Fourier Transform method previously used on Ganymede and on other areas of Europa (Patel et al., 1999 JGR), to derive common wavelengths for the subunits of the ubiquitous ridged plains terrain. These results have important implications for differentiating between possible formation mechanisms—extensional tilt blocks (Pappalardo et al., 1995 JGR) or folds (Leonard et al., 2015 LPSC Abstract)—and for potential future missions. We continue this method for another high-resolution region taken in the E12 orbit, WEDGES01 and 02, with the specific goal of investigating how the variations in ridged plains morphologies relate across the surface of Europa.

High-resolution 3D-constructive interference in steady-state MR imaging and 3D time-of-flight MR angiography in neurovascular compression: a comparison between 3T and 1.5T.

PubMed

Garcia, M; Naraghi, R; Zumbrunn, T; Rösch, J; Hastreiter, P; Dörfler, A

2012-08-01

High-resolution MR imaging is useful for diagnosis and preoperative planning in patients with NVC. Because high-field MR imaging promises higher SNR and resolution, the aim of this study was to determine the value of high-resolution 3D-CISS and 3D-TOF MRA at 3T compared with 1.5T in patients with NVC. Forty-seven patients with NVC, trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia were examined at 1.5T and 3T, including high-resolution 3D-CISS and 3D-TOF MRA sequences. Delineation of anatomic structures, overall image quality, severity of artifacts, visibility of NVC, and assessment of the SNR and CNR were compared between field strengths. SNR and CNR were significantly higher at 3T (P < .001). Significantly better anatomic conspicuity, including delineation of CNs, nerve branches, and assessment of small vessels, was obtained at 3T (P < .02). Severity of artifacts was significantly lower at 3T (P < .001). Consequently, overall image quality was significantly higher at 3T. NVC was significantly better delineated at 3T (P < .001). Six patients in whom NVC was not with certainty identifiable at 1.5T were correctly diagnosed at 3T. Patients with NVC may benefit from the higher resolution and greater sensitivity of 3T for preoperative assessment of NVC, and 3T may be of particular value when 1.5T is equivocal.

LLNL/Lion Precision LVDT amplifier

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hopkins, D.J.

1994-04-01

A high-precision, low-noise, LVDT amplifier has been developed which is a significant advancement on the current state of the art in contact displacement measurement. This amplifier offers the dynamic range of a typical LVDT probe but with a resolution that rivals that of non contact displacement measuring systems such as capacitance gauges and laser interferometers. Resolution of 0.1 {mu} in with 100 Hz bandwidth is possible. This level of resolution is over an order of magnitude greater than what is now commercially available. A front panel switch can reduce the bandwidth to 2.5 Hz and attain a resolution of 0.025more » {mu} in. This level of resolution meets or exceeds that of displacement measuring laser interferometry or capacitance gauge systems. Contact displacement measurement offers high part spatial resolution and therefore can measure not only part contour but surface finish. Capacitance gauges and displacement laser interferometry offer poor part spatial resolution and can not provide good surface finish measurements. Machine tool builders, meteorologists and quality inspection departments can immediately utilize the higher accuracy and capabilities that this amplifier offers. The precision manufacturing industry can improve as a result of improved capability to measure parts that help reduce costs and minimize material waste.« less

Isotopic substitution of a hydrogen bond: A near infrared study of the intramolecular states in (DF)2

NASA Astrophysics Data System (ADS)

Davis, Scott; Anderson, David T.; Farrell, John T., Jr.; Nesbitt, David J.

1996-06-01

High resolution near infrared spectra of the two high frequency intramolecular modes in (DF)2 have been characterized using a slit-jet infrared spectrometer. In total, four pairs of vibration-rotation-tunneling (VRT) bands are observed, corresponding to K=0 and K=1 excitation of both the ν2 (``bound'') and ν1 (``free'') intramolecular DF stretching modes. Analysis of the rotationally resolved spectra provides vibrational origins, rotational constants, tunneling splittings and upper state predissociation lifetimes for all four states. The rotational constants indicate that the deuterated hydrogen bond contracts and bends upon intramolecular excitation, analogous to what has been observed for (HF)2. The isotope and K dependence of tunneling splittings for (HF)2 and (DF)2 in both intramolecular modes is interpreted in terms of a semiclassical 1-D tunneling model. High resolution line shape measurements reveal vibrational predissociation broadening in (DF)2: 56(2) and 3(2) MHz for the ν2 (bound) and ν1 (free) intramolecular stretching modes, respectively. This 20-fold mode specific enhancement parallels the ≥30-fold enhancement observed between analogous intramolecular modes of (HF)2, further elucidating the role of nonstatistical predissociation dynamics in such hydrogen bonded clusters.

Fusion of multi-source remote sensing data for agriculture monitoring tasks

NASA Astrophysics Data System (ADS)

Skakun, S.; Franch, B.; Vermote, E.; Roger, J. C.; Becker Reshef, I.; Justice, C. O.; Masek, J. G.; Murphy, E.

2016-12-01

Remote sensing data is essential source of information for enabling monitoring and quantification of crop state at global and regional scales. Crop mapping, state assessment, area estimation and yield forecasting are the main tasks that are being addressed within GEO-GLAM. Efficiency of agriculture monitoring can be improved when heterogeneous multi-source remote sensing datasets are integrated. Here, we present several case studies of utilizing MODIS, Landsat-8 and Sentinel-2 data along with meteorological data (growing degree days - GDD) for winter wheat yield forecasting, mapping and area estimation. Archived coarse spatial resolution data, such as MODIS, VIIRS and AVHRR, can provide daily global observations that coupled with statistical data on crop yield can enable the development of empirical models for timely yield forecasting at national level. With the availability of high-temporal and high spatial resolution Landsat-8 and Sentinel-2A imagery, course resolution empirical yield models can be downscaled to provide yield estimates at regional and field scale. In particular, we present the case study of downscaling the MODIS CMG based generalized winter wheat yield forecasting model to high spatial resolution data sets, namely harmonized Landsat-8 - Sentinel-2A surface reflectance product (HLS). Since the yield model requires corresponding in season crop masks, we propose an automatic approach to extract winter crop maps from MODIS NDVI and MERRA2 derived GDD using Gaussian mixture model (GMM). Validation for the state of Kansas (US) and Ukraine showed that the approach can yield accuracies > 90% without using reference (ground truth) data sets. Another application of yearly derived winter crop maps is their use for stratification purposes within area frame sampling for crop area estimation. In particular, one can simulate the dependence of error (coefficient of variation) on the number of samples and strata size. This approach was used for estimating the area of winter crops in Ukraine for 2013-2016. The GMM-GDD approach is further extended for HLS data to provide automatic winter crop mapping at 30 m resolution for crop yield model and area estimation. In case of persistent cloudiness, addition of Sentinel-1A synthetic aperture radar (SAR) images is explored for automatic winter crop mapping.

A High-Resolution Aerosol Retrieval Method for Urban Areas Using MISR Data

NASA Astrophysics Data System (ADS)

Moon, T.; Wang, Y.; Liu, Y.; Yu, B.

2012-12-01

Satellite-retrieved Aerosol Optical Depth (AOD) can provide a cost-effective way to monitor particulate air pollution without using expensive ground measurement sensors. One of the current state-of-the-art AOD retrieval method is NASA's Multi-angle Imaging SpectroRadiometer (MISR) operational algorithm, which has the spatial resolution of 17.6 km x 17.6 km. While the MISR baseline scheme already leads to exciting research opportunities to study particle compositions at regional scale, its spatial resolution is too coarse for analyzing urban areas where the AOD level has stronger spatial variations. We develop a novel high-resolution AOD retrieval algorithm that still uses MISR's radiance observations but has the resolution of 4.4km x 4.4km. We achieve the high resolution AOD retrieval by implementing a hierarchical Bayesian model and Monte-Carlo Markov Chain (MCMC) inference method. Our algorithm not only improves the spatial resolution, but also extends the coverage of AOD retrieval and provides with additional composition information of aerosol components that contribute to the AOD. We validate our method using the recent NASA's DISCOVER-AQ mission data, which contains the ground measured AOD values for Washington DC and Baltimore area. The validation result shows that, compared to the operational MISR retrievals, our scheme has 41.1% more AOD retrieval coverage for the DISCOVER-AQ data points and 24.2% improvement in mean-squared error (MSE) with respect to the AERONET ground measurements.

Phenological classification of the United States: A geographic framework for extending multi-sensor time-series data

USGS Publications Warehouse

Gu, Yingxin; Brown, Jesslyn F.; Miura, Tomoaki; van Leeuwen, Willem J.D.; Reed, Bradley C.

2010-01-01

This study introduces a new geographic framework, phenological classification, for the conterminous United States based on Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index (NDVI) time-series data and a digital elevation model. The resulting pheno-class map is comprised of 40 pheno-classes, each having unique phenological and topographic characteristics. Cross-comparison of the pheno-classes with the 2001 National Land Cover Database indicates that the new map contains additional phenological and climate information. The pheno-class framework may be a suitable basis for the development of an Advanced Very High Resolution Radiometer (AVHRR)-MODIS NDVI translation algorithm and for various biogeographic studies.

Achieving superresolution with illumination-enhanced sparsity.

PubMed

Yu, Jiun-Yann; Becker, Stephen R; Folberth, James; Wallin, Bruce F; Chen, Simeng; Cogswell, Carol J

2018-04-16

Recent advances in superresolution fluorescence microscopy have been limited by a belief that surpassing two-fold resolution enhancement of the Rayleigh resolution limit requires stimulated emission or the fluorophore to undergo state transitions. Here we demonstrate a new superresolution method that requires only image acquisitions with a focused illumination spot and computational post-processing. The proposed method utilizes the focused illumination spot to effectively reduce the object size and enhance the object sparsity and consequently increases the resolution and accuracy through nonlinear image post-processing. This method clearly resolves 70nm resolution test objects emitting ~530nm light with a 1.4 numerical aperture (NA) objective, and, when imaging through a 0.5NA objective, exhibits high spatial frequencies comparable to a 1.4NA widefield image, both demonstrating a resolution enhancement above two-fold of the Rayleigh resolution limit. More importantly, we examine how the resolution increases with photon numbers, and show that the more-than-two-fold enhancement is achievable with realistic photon budgets.

Solid state nuclear magnetic resonance studies of prion peptides and proteins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heller, Jonathan

1997-08-01

High-resolution structural studies using x-ray diffraction and solution nuclear magnetic resonance (NMR) are not feasible for proteins of low volubility and high tendency to aggregate. Solid state NMR (SSNMR) is in principle capable of providing structural information in such systems, however to do this efficiently and accurately, further SSNMR tools must be developed This dissertation describes the development of three new methods and their application to a biological system of interest, the priori protein (PrP).

Spectroscopic study on deuterated benzenes. II. High-resolution laser spectroscopy and rotational structure in the S{sub 1} state

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kunishige, Sachi; Katori, Toshiharu; Baba, Masaaki, E-mail: baba@kuchem.kyoto-u.ac.jp

High-resolution spectra of the S{sub 1}←S{sub 0} transition in jet-cooled deuterated benzenes were observed using pulse dye amplification of single-mode laser light and mass-selective resonance enhanced multiphoton ionization (REMPI) detection. The vibrational and rotational structures were accurately analyzed for the vibronic levels in the S{sub 1} state. The degenerate 6{sup 1} levels of C{sub 6}H{sub 6} or C{sub 6}D{sub 6} are split into 6a{sup 1} and 6b{sup 1} in many of deuterated benzenes. The rigid-rotor rotational constants were assessed and found to be slightly different between 6a and 6b because of different mean molecular structures. Their rotational levels are significantlymore » shifted by Coriolis interactions. It was found that the Coriolis parameter proportionally changed with the number of substituted D atoms.« less

The STROBE-X Science Case: An Overview

NASA Astrophysics Data System (ADS)

Maccarone, Thomas J.; STROBE-X consortium

2018-01-01

STROBE-X is a proposed NASA Probe class mission aimed at the extremes of high throughput X-ray astronomy, making use of an 8 m^2 total collecting area, CCD-quality spectral resolution, and a state-of-the art wide field monitor with both very large instantaneous sky coverage (ideal for follow-up of LIGO events) and good intrinsic spectral and time resolution. The core goals are time domain astrophysics and high count spectroscopy. Its capabilities span a broad range of topics, including those traditional to X-ray timing missions, like understanding the equation of states of neutron stars, and the spin distributions and masses of neutron stars and stellar mass and supermassive black holes, and the rates, and detailed properties, of a variety of classes of X-ray transients; and also topics not traditionally studied by such missions such as the spectra of supernova remnants, comets and of clusters and groups of galaxies.

Solid state parameters, structure elucidation, High Resolution X-Ray Diffraction (HRXRD), phase matching, thermal and impedance analysis on L-Proline trichloroacetate (L-PTCA) NLO single crystals.

PubMed

Kalaiselvi, P; Raj, S Alfred Cecil; Jagannathan, K; Vijayan, N; Bhagavannarayana, G; Kalainathan, S

2014-11-11

Nonlinear optical single crystal of L-Proline trichloroacetate (L-PTCA) was successfully grown by Slow Evaporation Solution Technique (SEST). The grown crystals were subjected to single crystal X-ray diffraction analysis to confirm the structure. From the single crystal XRD data, solid state parameters were determined for the grown crystal. The crystalline perfection has been evaluated using high resolution X-ray diffractometer. The frequencies of various functional groups were identified from FTIR spectral analysis. The percentage of transmittance was obtained from UV Visible spectral analysis. TGA-DSC measurements indicate the thermal stability of the crystal. The dielectric constant, dielectric loss and ac conductivity were measured by the impedance analyzer. The DC conductivity was calculated by the cole-cole plot method. Copyright © 2014 Elsevier B.V. All rights reserved.

Electronic state spectroscopy by high-resolution vacuum ultraviolet photoabsorption, He(I) photoelectron spectroscopy and ab initio calculations of ethyl acetate

NASA Astrophysics Data System (ADS)

Śmialek, Malgorzata A.; Łabuda, Marta; Guthmuller, Julien; Hubin-Franskin, Marie-Jeanne; Delwiche, Jacques; Hoffmann, Søren Vrønning; Jones, Nykola C.; Mason, Nigel J.; Limão-Vieira, Paulo

2016-06-01

The high-resolution vacuum ultraviolet photoabsorption spectrum of ethyl acetate, C4H8O2, is presented over the energy range 4.5-10.7 eV (275.5-116.0 nm). Valence and Rydberg transitions and their associated vibronic series observed in the photoabsorption spectrum, have been assigned in accordance with new ab initio calculations of the vertical excitation energies and oscillator strengths. Also, the photoabsorption cross sections have been used to calculate the photolysis lifetime of this ester in the upper stratosphere (20-50 km). Calculations have also been carried out to determine the ionisation energies and fine structure of the lowest ionic state of ethyl acetate and are compared with a newly recorded photoelectron spectrum (from 9.5 to 16.7 eV). Vibrational structure is observed in the first photoelectron band of this molecule for the first time.

Subnanosecond measurements of detonation fronts in solid high explosives

NASA Astrophysics Data System (ADS)

Sheffield, S. A.; Bloomquist, D. D.; Tarver, C. M.

1984-04-01

Detonation fronts in solid high explosives have been examined through measurements of particle velocity histories resulting from the interaction of a detonation wave with a thin metal foil backed by a water window. Using a high time resolution velocity-interferometer system, experiments were conducted on three explosives—a TATB (1,3,5-triamino-trinitrobenzene)-based explosive called PBX-9502, TNT (2,4,6-Trinitrotoluene), and CP (2-{5-cyanotetrazolato} pentaamminecobalt {III} perchlorate). In all cases, detonation-front rise times were found to be less than the 300 ps resolution of the interferometer system. The thermodynamic state in the front of the detonation wave was estimated to be near the unreacted state determined from an extrapolation of low-pressure unreacted Hugoniot data for both TNT and PBX-9502 explosives. Computer calculations based on an ignition and growth model of a Zeldovich-von Neumann-Doering (ZND) detonation wave show good agreement with the measurements. By using the unreacted Hugoniot and a JWL equation of state for the reaction products, we estimated the initial reaction rate in the high explosive after the detonation wave front interacted with the foil to be 40 μs-1 for CP, 60 μs-1 for TNT, and 80 μs-1 for PBX-9502. The shape of the profiles indicates the reaction rate decreases as reaction proceeds.

Stochastic Short-term High-resolution Prediction of Solar Irradiance and Photovoltaic Power Output

DOE Office of Scientific and Technical Information (OSTI.GOV)

Melin, Alexander M.; Olama, Mohammed M.; Dong, Jin

The increased penetration of solar photovoltaic (PV) energy sources into electric grids has increased the need for accurate modeling and prediction of solar irradiance and power production. Existing modeling and prediction techniques focus on long-term low-resolution prediction over minutes to years. This paper examines the stochastic modeling and short-term high-resolution prediction of solar irradiance and PV power output. We propose a stochastic state-space model to characterize the behaviors of solar irradiance and PV power output. This prediction model is suitable for the development of optimal power controllers for PV sources. A filter-based expectation-maximization and Kalman filtering mechanism is employed tomore » estimate the parameters and states in the state-space model. The mechanism results in a finite dimensional filter which only uses the first and second order statistics. The structure of the scheme contributes to a direct prediction of the solar irradiance and PV power output without any linearization process or simplifying assumptions of the signal’s model. This enables the system to accurately predict small as well as large fluctuations of the solar signals. The mechanism is recursive allowing the solar irradiance and PV power to be predicted online from measurements. The mechanism is tested using solar irradiance and PV power measurement data collected locally in our lab.« less

A High-Resolution Godunov Method for Compressible Multi-Material Flow on Overlapping Grids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Banks, J W; Schwendeman, D W; Kapila, A K

2006-02-13

A numerical method is described for inviscid, compressible, multi-material flow in two space dimensions. The flow is governed by the multi-material Euler equations with a general mixture equation of state. Composite overlapping grids are used to handle complex flow geometry and block-structured adaptive mesh refinement (AMR) is used to locally increase grid resolution near shocks and material interfaces. The discretization of the governing equations is based on a high-resolution Godunov method, but includes an energy correction designed to suppress numerical errors that develop near a material interface for standard, conservative shock-capturing schemes. The energy correction is constructed based on amore » uniform pressure-velocity flow and is significant only near the captured interface. A variety of two-material flows are presented to verify the accuracy of the numerical approach and to illustrate its use. These flows assume an equation of state for the mixture based on Jones-Wilkins-Lee (JWL) forms for the components. This equation of state includes a mixture of ideal gases as a special case. Flow problems considered include unsteady one-dimensional shock-interface collision, steady interaction of an planar interface and an oblique shock, planar shock interaction with a collection of gas-filled cylindrical inhomogeneities, and the impulsive motion of the two-component mixture in a rigid cylindrical vessel.« less

High-Resolution Laser Spectroscopy of the tilde{B} ← tilde{X} Transition of 14NO3 Radical: Vibrationally Excited States of the tilde{B} State

NASA Astrophysics Data System (ADS)

Kasahara, Shunji; Tada, Kohei; Hirata, Michihiro; Ishiwata, Takashi; Hirota, Eizi

2016-06-01

Rotationally-resolved high-resolution fluorescence excitation spectra of the tilde{B} 2E' ← tilde{X} 2A2' electronic transition of 14NO3 radical have been observed for 15860-15920 cm-1 region. Sub-Doppler excitation spectra were measured by crossing a single-mode laser beam perpendicular to a collimated radical beam, which was formed by the heat decomposition of 14N2O5; 14N2O5 → 14NO3 + 14NO2. We have also measured the high-resolution fluorescence excitation spectra of the 14NO2 tilde{A} 2B{2} ← tilde{X} 2A1 transition to distinguish the 14NO3 signals from the 14NO2 signals in the observed region. The typical linewidth was 30 MHz and the absolute wavenumber was calibrated with accuracy 0.0001 cm-1 by measurement of the Doppler-free saturation spectrum of iodine molecule and fringe pattern of the stabilized etalon. The observed rotational lines were too complicated to find any rotational series. In the observed spectra, only the rotational line pairs from the tilde{X} 2A2'(v''=0, K''=0, N''=1, F1 and F2) levels are assigned unambiguously by using the combination differences of the tilde{X} 2A2' state and measurement of the Zeeman splittings similar to the analysis of the 0-0 band at around 15100 cm-1 region. The observed results suggest the observed vibrationally excited states of the tilde{B} 2E' state are also interacts with the other vibronic levels similar to the tilde{B} 2E'(v'=0) level. K. Tada, W. Kashihara, M. Baba, T. Ishiwata, E. Hirota, and S. Kasahara, J. Chem. Physc. 141, 184307 (2014). K. Tada, T. Ishiwata, E. Hirota, and S. Kasahara, J. Mol. Spectrosc., 321, 23 (2016)

High resolution synchrotron radiation Fourier transform infrared spectrum of the COH-bending mode in methanol-D1 (CH2DOH)

NASA Astrophysics Data System (ADS)

Mukhopadhyay, Indra; Billinghurst, B. E.

2017-09-01

In this work the high resolution synchrotron radiation Fourier transform spectrum in the range 1180-1300 cm-1 corresponding to the COH-bending vibrational mode has been recorded and analyzed. The spectrum shows a structure analogous to a parallel band. Since the COH bending motion is one of the main contributors to the asymmetry in the torsional hindering potential barrier, the torsional barrier height in the excited state is expected to be quite different from that of the ground state. This makes the spectrum to spread over a wide region. Although the spectrum corresponding to the P- and R-branch looks very complicated, the Q-branches are well resolved and can be identified without much difficulty. It was possible to assign the spectra for K = 0 to 10 for the trans- (e0) species. The interesting feature of the spectra is the absence of the lines for two other lower lying gauche symmetry species e1 and o1. The spectra due to any perpendicular transitions were absent as well. However some weak c-type transitions from gauche states (o1 and e1) in the ground state to the trans-species (e0) in the COD bending mode for low K-values ΔK = 0 have been seen to be present in the spectra. These along with similar transitions for the OCD vibrational band are under investigation and the results will be communicated elsewhere. In the present work, analysis of the spectrum has been carried out to obtain precise term values and molecular parameters in the excited COH-bending state for the trans-species. The results will be shown valuable to assign similar spectra for the methanol-D2. This work represents the first reported high resolution study of this illusive vibrational mode in methanol-D1.

High-Resolution Infrared Imaging and Polarimetry plus Spectroscopy of Evolved Red and Yellow Supergiants

NASA Astrophysics Data System (ADS)

Gordon, Michael Scott; Humphreys, Roberta; Jones, Terry J.; Gehrz, Robert D.

2018-01-01

To what extent mass loss and periods of enhanced stellar outflow can influence the terminal state of the most massive stars remains an outstanding question in the fields of stellar physics, chemical enrichment of the Local Universe, andsupernova research. For my dissertation, I focus on characterizing the stellar ejecta around supergiants through a combination of observing techniques. Using the LBT, MMT, IRTF, VLT, and SOFIA observatories, I have performed high-resolution imaging, spectroscopy, and polarimetry—methods that provide us with keen insight on mass-loss histories and 3D morphology of the Local Group's most fascinating stars.Based on spectroscopic evidence for mass loss in the optical and the presence ofcircumstellar (CS) dust in infrared SEDs, we find that 30%–40% of observed yellow supergiants in M31 and M33 are likely in a post-RSG state. We also presentnear-IR spectra from IRTF/SPeX of optically-obscured RSGs in M33. These IR-bright sources likely have some of the highest mass-loss rates and are self-obscured in the optical by their own CS ejecta. For Galactic red supergiants (RSGs), we are able to observe the gas and CS dust ejecta both close in to the central star and at larger distances. The resulting radial profiles are valuable probes on timescale for the ejecta when combined with radiative-transfer models. We find evidence for both variable/high mass-loss events and constant mass loss over the last few thousand years. Finally, we discuss the use of high-resolution imaging polarimetry with VLT/NACO of two co-eval RSG clusters toward the Galactic center. The resulting polarized intensity images in the near-infrared provide unprecedented spatial and contrast resolution of the scattered light from extended nebular material.

Ab initio prediction of fast non-equilibrium transport of nascent polarons in SrI2: a key to high-performance scintillation

NASA Astrophysics Data System (ADS)

Zhou, Fei; Sadigh, Babak; Erhart, Paul; Åberg, Daniel

2016-08-01

The excellent light yield proportionality of europium-doped strontium iodide (SrI2:Eu) has resulted in state-of-the-art γ-ray detectors with remarkably high-energy resolution, far exceeding that of most halide compounds. In this class of materials, the formation of self-trapped hole polarons is very common. However, polaron formation is usually expected to limit carrier mobilities and has been associated with poor scintillator light-yield proportionality and resolution. Here using a recently developed first-principles method, we perform an unprecedented study of polaron transport in SrI2, both for equilibrium polarons, as well as nascent polarons immediately following a self-trapping event. We propose a rationale for the unexpected high-energy resolution of SrI2. We identify nine stable hole polaron configurations, which consist of dimerised iodine pairs with polaron-binding energies of up to 0.5 eV. They are connected by a complex potential energy landscape that comprises 66 unique nearest-neighbour migration paths. Ab initio molecular dynamics simulations reveal that a large fraction of polarons is born into configurations that migrate practically barrier free at room temperature. Consequently, carriers created during γ-irradiation can quickly diffuse away reducing the chance for non-linear recombination, the primary culprit for non-proportionality and resolution reduction. We conclude that the flat, albeit complex, landscape for polaron migration in SrI2 is a key for understanding its outstanding performance. This insight provides important guidance not only for the future development of high-performance scintillators but also of other materials, for which large polaron mobilities are crucial such as batteries and solid-state ionic conductors.

Ab initio prediction of fast non-equilibrium transport of nascent polarons in SrI 2: a key to high-performance scintillation [First-principles study of hole polaron formation and migration in strontium iodide

DOE PAGES

Zhou, Fei; Sadigh, Babak; Aberg, Daniel; ...

2016-08-12

The excellent light yield proportionality of europium-doped strontium iodide (SrI 2:Eu) has resulted in state-of-the-art γ-ray detectors with remarkably high-energy resolution, far exceeding that of most halide compounds. In this class of materials, the formation of self-trapped hole polarons is very common. However, polaron formation is usually expected to limit carrier mobilities and has been associated with poor scintillator light-yield proportionality and resolution. Here using a recently developed first-principles method, we perform an unprecedented study of polaron transport in SrI 2, both for equilibrium polarons, as well as nascent polarons immediately following a self-trapping event. We propose a rationale formore » the unexpected high-energy resolution of SrI 2. We identify nine stable hole polaron configurations, which consist of dimerised iodine pairs with polaron-binding energies of up to 0.5 eV. They are connected by a complex potential energy landscape that comprises 66 unique nearest-neighbour migration paths. Ab initio molecular dynamics simulations reveal that a large fraction of polarons is born into configurations that migrate practically barrier free at room temperature. Consequently, carriers created during γ-irradiation can quickly diffuse away reducing the chance for nonlinear recombination, the primary culprit for non-proportionality and resolution reduction. We conclude that the flat, albeit complex, landscape for polaron migration in SrI 2 is a key for understanding its outstanding performance. This insight provides important guidance not only for the future development of high-performance scintillators but also of other materials, for which large polaron mobilities are crucial such as batteries and solid-state ionic conductors.« less

Chaotic Brillouin optical correlation-domain analysis

NASA Astrophysics Data System (ADS)

Zhang, Jianzhong; Zhang, Mingtao; Zhang, Mingjiang; Liu, Yi; Feng, Changkun; Wang, Yahui; Wang, Yuncai

2018-04-01

We propose and experimentally demonstrate a chaotic Brillouin optical correlation-domain analysis (BOCDA) system for distributed fiber sensing. The utilization of the chaotic laser with low coherent state ensures high spatial resolution. The experimental results demonstrate a 3.92-cm spatial resolution over a 906-m measurement range. The uncertainty in the measurement of the local Brillouin frequency shift is 1.2MHz. The measurement signal-to-noise ratio is given, which is agreement with the theoretical value.

High-resolution high-sensitivity elemental imaging by secondary ion mass spectrometry: from traditional 2D and 3D imaging to correlative microscopy

NASA Astrophysics Data System (ADS)

Wirtz, T.; Philipp, P.; Audinot, J.-N.; Dowsett, D.; Eswara, S.

2015-10-01

Secondary ion mass spectrometry (SIMS) constitutes an extremely sensitive technique for imaging surfaces in 2D and 3D. Apart from its excellent sensitivity and high lateral resolution (50 nm on state-of-the-art SIMS instruments), advantages of SIMS include high dynamic range and the ability to differentiate between isotopes. This paper first reviews the underlying principles of SIMS as well as the performance and applications of 2D and 3D SIMS elemental imaging. The prospects for further improving the capabilities of SIMS imaging are discussed. The lateral resolution in SIMS imaging when using the microprobe mode is limited by (i) the ion probe size, which is dependent on the brightness of the primary ion source, the quality of the optics of the primary ion column and the electric fields in the near sample region used to extract secondary ions; (ii) the sensitivity of the analysis as a reasonable secondary ion signal, which must be detected from very tiny voxel sizes and thus from a very limited number of sputtered atoms; and (iii) the physical dimensions of the collision cascade determining the origin of the sputtered ions with respect to the impact site of the incident primary ion probe. One interesting prospect is the use of SIMS-based correlative microscopy. In this approach SIMS is combined with various high-resolution microscopy techniques, so that elemental/chemical information at the highest sensitivity can be obtained with SIMS, while excellent spatial resolution is provided by overlaying the SIMS images with high-resolution images obtained by these microscopy techniques. Examples of this approach are given by presenting in situ combinations of SIMS with transmission electron microscopy (TEM), helium ion microscopy (HIM) and scanning probe microscopy (SPM).

Note: Large active area solid state photon counter with 20 ps timing resolution and 60 fs detection delay stability

NASA Astrophysics Data System (ADS)

Prochazka, Ivan; Kodet, Jan; Eckl, Johann; Blazej, Josef

2017-10-01

We are reporting on the design, construction, and performance of a photon counting detector system, which is based on single photon avalanche diode detector technology. This photon counting device has been optimized for very high timing resolution and stability of its detection delay. The foreseen application of this detector is laser ranging of space objects, laser time transfer ground to space and fundamental metrology. The single photon avalanche diode structure, manufactured on silicon using K14 technology, is used as a sensor. The active area of the sensor is circular with 200 μm diameter. Its photon detection probability exceeds 40% in the wavelength range spanning from 500 to 800 nm. The sensor is operated in active quenching and gating mode. A new control circuit was optimized to maintain high timing resolution and detection delay stability. In connection to this circuit, timing resolution of the detector is reaching 20 ps FWHM. In addition, the temperature change of the detection delay is as low as 70 fs/K. As a result, the detection delay stability of the device is exceptional: expressed in the form of time deviation, detection delay stability of better than 60 fs has been achieved. Considering the large active area aperture of the detector, this is, to our knowledge, the best timing performance reported for a solid state photon counting detector so far.

Fundamental Attributes of Exemplary State Special Education Dispute Resolution Systems

ERIC Educational Resources Information Center

Center for Appropriate Dispute Resolution in Special Education (CADRE), 2013

2013-01-01

Between Fall 2008 and Summer 2010, the Center for Appropriate Dispute Resolution in Special Education (CADRE) analyzed state special education dispute resolution systems and their components, with the objective of identifying particularly effective systems and creating a resource that other states could draw on when considering improvement…

High Pressure Particulate Physics Facility

DTIC Science & Technology

2011-03-26

controlled loading conditions, nanosecond time resolution diagnostics are required. Therefore, state of the art diagnostic tools such as Velocity...front end plate. The Data Acquisition System (DAS) is based on the state of the art National Instruments PXI system. The architecture provides...obtained by copper wire. In the future x-ray cinematography , line VISAR and time indexed spectroscopy are planned. SECTION III SUMMARY We are

High School Debate Topic, 1996-1997. Subject Bibliography (SB)043.

ERIC Educational Resources Information Center

United States Government Printing Office, Washington, DC.

This 10-item annotated bibliography presents U.S. government documents suitable for use in preparation for a high school debate on the resolution that the federal government should establish a program to substantially reduce juvenile crime in the United States. Items in the annotated bibliography address correctional philosophy, community response…

High School Debate Topic, 1998-1999. Subject Bibliography (SB)043.

ERIC Educational Resources Information Center

United States Government Printing Office, Washington, DC.

This 12-item annotated bibliography presents U.S. government documents suitable for use in preparation for a high school debate on the resolution that the United States should substantially change its foreign policy toward Russia. Items in the annotated bibliography address American-Ukranian nuclear relations; economic policy and trade practices;…

High-resolution typing of Chlamydia trachomatis: epidemiological and clinical uses.

PubMed

de Vries, Henry J C; Schim van der Loeff, Maarten F; Bruisten, Sylvia M

2015-02-01

A state-of-the-art overview of molecular Chlamydia trachomatis typing methods that are used for routine diagnostics and scientific studies. Molecular epidemiology uses high-resolution typing techniques such as multilocus sequence typing, multilocus variable number of tandem repeats analysis, and whole-genome sequencing to identify strains based on their DNA sequence. These data can be used for cluster, network and phylogenetic analyses, and are used to unveil transmission networks, risk groups, and evolutionary pathways. High-resolution typing of C. trachomatis strains is applied to monitor treatment efficacy and re-infections, and to study the recent emergence of lymphogranuloma venereum (LGV) amongst men who have sex with men in high-income countries. Chlamydia strain typing has clinical relevance in disease management, as LGV needs longer treatment than non-LGV C. trachomatis. It has also led to the discovery of a new variant Chlamydia strain in Sweden, which was not detected by some commercial C. trachomatis diagnostic platforms. After a brief history and comparison of the various Chlamydia typing methods, the applications of the current techniques are described and future endeavors to extend scientific understanding are formulated. High-resolution typing will likely help to further unravel the pathophysiological mechanisms behind the wide clinical spectrum of chlamydial disease.

Multiband multi-echo imaging of simultaneous oxygenation and flow timeseries for resting state connectivity.

PubMed

Cohen, Alexander D; Nencka, Andrew S; Lebel, R Marc; Wang, Yang

2017-01-01

A novel sequence has been introduced that combines multiband imaging with a multi-echo acquisition for simultaneous high spatial resolution pseudo-continuous arterial spin labeling (ASL) and blood-oxygenation-level dependent (BOLD) echo-planar imaging (MBME ASL/BOLD). Resting-state connectivity in healthy adult subjects was assessed using this sequence. Four echoes were acquired with a multiband acceleration of four, in order to increase spatial resolution, shorten repetition time, and reduce slice-timing effects on the ASL signal. In addition, by acquiring four echoes, advanced multi-echo independent component analysis (ME-ICA) denoising could be employed to increase the signal-to-noise ratio (SNR) and BOLD sensitivity. Seed-based and dual-regression approaches were utilized to analyze functional connectivity. Cerebral blood flow (CBF) and BOLD coupling was also evaluated by correlating the perfusion-weighted timeseries with the BOLD timeseries. These metrics were compared between single echo (E2), multi-echo combined (MEC), multi-echo combined and denoised (MECDN), and perfusion-weighted (PW) timeseries. Temporal SNR increased for the MECDN data compared to the MEC and E2 data. Connectivity also increased, in terms of correlation strength and network size, for the MECDN compared to the MEC and E2 datasets. CBF and BOLD coupling was increased in major resting-state networks, and that correlation was strongest for the MECDN datasets. These results indicate our novel MBME ASL/BOLD sequence, which collects simultaneous high-resolution ASL/BOLD data, could be a powerful tool for detecting functional connectivity and dynamic neurovascular coupling during the resting state. The collection of more than two echoes facilitates the use of ME-ICA denoising to greatly improve the quality of resting state functional connectivity MRI.

The Western States Water Mission: A Hyper-Resolution Hydrological Model and Data Integration Platform for the Western United States

NASA Astrophysics Data System (ADS)

Famiglietti, J. S.; David, C. H.; Reager, J. T., II; Oaida, C.; Stampoulis, D.; Levoe, S.; Liu, P. W.; Trangsrud, A.; Basilio, R. R.; Allen, G. H.; Crichton, D. J.; Emery, C. M.; Farr, T.; Granger, S. L.; Hobbs, J.; Malhotra, S.; Osterman, G. B.; Rueckert, M.; Turmon, M.

2017-12-01

The Western States Water Mission (WSWM) is a high-resolution (3 km2), hydrological model and data integration platform under development at the Jet Propulsion Laboratory for the last 2 years. Distinctive features of the WSWM are its explicit representations of river networks and deep groundwater, an emphasis on uncertainty quantification, a major visualization and data distribution effort, and its focus on multivariate data assimilation, including GRACE/FO, SMAP, SWOT and MODSCAG fractional snow covered area. Importantly, the WSWM is actively managed as a flight project, i.e. with the rigor of a satellite mission. In this presentation we give an overview of the WSWM, including past accomplishments status, and future plans. In particular, results from recent 30-year simulations with GRACE and MODSCAG assimilation will be presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

M. P. Jensen; Toto, T.

Standard Atmospheric Radiation Measurement (ARM) Climate Research Facility sounding files provide atmospheric state data in one dimension of increasing time and height per sonde launch. Many applications require a quick estimate of the atmospheric state at higher time resolution. The INTERPOLATEDSONDE (i.e., Interpolated Sounding) Value-Added Product (VAP) transforms sounding data into continuous daily files on a fixed time-height grid, at 1-minute time resolution, on 332 levels, from the surface up to a limit of approximately 40 km. The grid extends that high so the full height of soundings can be captured; however, most soundings terminate at an altitude between 25more » and 30 km, above which no data is provided. Between soundings, the VAP linearly interpolates atmospheric state variables in time for each height level. In addition, INTERPOLATEDSONDE provides relative humidity scaled to microwave radiometer (MWR) observations.« less

Monitoring of Antarctic moss ecosystems using a high spatial resolution imaging spectroscopy

NASA Astrophysics Data System (ADS)

Malenovsky, Zbynek; Lucieer, Arko; Robinson, Sharon; Harwin, Stephen; Turner, Darren; Veness, Tony

2013-04-01

The most abundant photosynthetically active plants growing along the rocky Antarctic shore are mosses of three species: Schistidium antarctici, Ceratodon purpureus, and Bryum pseudotriquetrum. Even though mosses are well adapted to the extreme climate conditions, their existence in Antarctica depends strongly on availability of liquid water from snowmelt during the short summer season. Recent changes in temperature, wind speed and stratospheric ozone are stimulating faster evaporation, which in turn influences moss growing rate, health state and abundance. This makes them an ideal bio-indicator of the Antarctic climate change. Very short growing season, lasting only about three months, requires a time efficient, easily deployable and spatially resolved method for monitoring the Antarctic moss beds. Ground and/or low-altitude airborne imaging spectroscopy (called also hyperspectral remote sensing) offers a fast and spatially explicit approach to investigate an actual spatial extent and physiological state of moss turfs. A dataset of ground-based spectral images was acquired with a mini-Hyperspec imaging spectrometer (Headwall Inc., the USA) during the Antarctic summer 2012 in the surroundings of the Australian Antarctic station Casey (Windmill Islands). The collection of high spatial resolution spectral images, with pixels about 2 cm in size containing from 162 up to 324 narrow spectral bands of wavelengths between 399 and 998 nm, was accompanied with point moss reflectance measurements recorded with the ASD HandHeld-2 spectroradiometer (Analytical Spectral Devices Inc., the USA). The first spectral analysis indicates significant differences in red-edge and near-infrared reflectance of differently watered moss patches. Contrary to high plants, where the Normalized Difference Vegetation Index (NDVI) represents an estimate of green biomass, NDVI of mosses indicates mainly the actual water content. Similarly to high plants, reflectance of visible wavelengths is controlled by the composition and content of various foliar pigments (chlorophylls, xanthophylls, etc.). Additionally, the high spectral resolution reflectance together with the narrow bandwidth allows retrieving the steady state chlorophyll fluorescence, which indicates the actual moss photosynthetic activity. A first airborne imaging spectroscopy acquisition with the mini-Hyperspec sensor on-board a low-flying remote-controlled multi-rotor helicopter (known as micro Unmanned Aerial Systems - UAS) will be performed during the summer 2013. The aim of the UAS observations is to generate high spatial resolution maps of actual physiological state of several moss beds located within the Australian Antarctic Territory. The regular airborne monitoring is expected to reveal spatio-temporal changes in the Antarctic moss ecosystems, indicating the impact of the global climate change in Antarctica.

Applications and Innovations for Use of High Definition and High Resolution Digital Motion Imagery in Space Operations

NASA Technical Reports Server (NTRS)

Grubbs, Rodney

2016-01-01

The first live High Definition Television (HDTV) from a spacecraft was in November, 2006, nearly ten years before the 2016 SpaceOps Conference. Much has changed since then. Now, live HDTV from the International Space Station (ISS) is routine. HDTV cameras stream live video views of the Earth from the exterior of the ISS every day on UStream, and HDTV has even flown around the Moon on a Japanese Space Agency spacecraft. A great deal has been learned about the operations applicability of HDTV and high resolution imagery since that first live broadcast. This paper will discuss the current state of real-time and file based HDTV and higher resolution video for space operations. A potential roadmap will be provided for further development and innovations of high-resolution digital motion imagery, including gaps in technology enablers, especially for deep space and unmanned missions. Specific topics to be covered in the paper will include: An update on radiation tolerance and performance of various camera types and sensors and ramifications on the future applicability of these types of cameras for space operations; Practical experience with downlinking very large imagery files with breaks in link coverage; Ramifications of larger camera resolutions like Ultra-High Definition, 6,000 [pixels] and 8,000 [pixels] in space applications; Enabling technologies such as the High Efficiency Video Codec, Bundle Streaming Delay Tolerant Networking, Optical Communications and Bayer Pattern Sensors and other similar innovations; Likely future operations scenarios for deep space missions with extreme latency and intermittent communications links.

Detection of grapes in natural environment using HOG features in low resolution images

NASA Astrophysics Data System (ADS)

Škrabánek, Pavel; Majerík, Filip

2017-07-01

Detection of grapes in real-life images has importance in various viticulture applications. A grape detector based on an SVM classifier, in combination with a HOG descriptor, has proven to be very efficient in detection of white varieties in high-resolution images. Nevertheless, the high time complexity of such utilization was not suitable for its real-time applications, even when a detector of a simplified structure was used. Thus, we examined possibilities of the simplified version application on images of lower resolutions. For this purpose, we designed a method aimed at search for a detector’s setting which gives the best time complexity vs. performance ratio. In order to provide precise evaluation results, we formed new extended datasets. We discovered that even applied on low-resolution images, the simplified detector, with an appropriate setting of all tuneable parameters, was competitive with other state of the art solutions. We concluded that the detector is qualified for real-time detection of grapes in real-life images.

Femtosecond MeV Electron Energy-Loss Spectroscopy

DOE PAGES

Li, R. K.; Wang, X. J.

2017-11-09

Pump-probe electron energy-loss spectroscopy (EELS) with femtosecond temporal resolution will be a transformative research tool for studying nonequilibrium chemistry and electronic dynamics of matter. Here in this article, we propose a concept of femtosecond EELS utilizing mega-electron-volt electron beams from a radio-frequency (rf) photocathode source. The high acceleration gradient and high beam energy of the rf gun are critical to the generation of 10-fs electron beams, which enables an improvement of the temporal resolution by more than 1 order of magnitude beyond the state of the art. In our proposal, the “referencebeam technique” relaxes the energy stability requirement of themore » rf power source by roughly 2 orders of magnitude. The requirements for the electron-beam quality, photocathode, spectrometer, and detector are also discussed. Supported by particle-tracking simulations, we demonstrate the feasibility of achieving subelectron- volt energy resolution and approximately 10-fs temporal resolution with existing or near-future hardware performance.« less

Advances in high-resolution imaging--techniques for three-dimensional imaging of cellular structures.

PubMed

Lidke, Diane S; Lidke, Keith A

2012-06-01

A fundamental goal in biology is to determine how cellular organization is coupled to function. To achieve this goal, a better understanding of organelle composition and structure is needed. Although visualization of cellular organelles using fluorescence or electron microscopy (EM) has become a common tool for the cell biologist, recent advances are providing a clearer picture of the cell than ever before. In particular, advanced light-microscopy techniques are achieving resolutions below the diffraction limit and EM tomography provides high-resolution three-dimensional (3D) images of cellular structures. The ability to perform both fluorescence and electron microscopy on the same sample (correlative light and electron microscopy, CLEM) makes it possible to identify where a fluorescently labeled protein is located with respect to organelle structures visualized by EM. Here, we review the current state of the art in 3D biological imaging techniques with a focus on recent advances in electron microscopy and fluorescence super-resolution techniques.

Femtosecond MeV Electron Energy-Loss Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, R. K.; Wang, X. J.

Pump-probe electron energy-loss spectroscopy (EELS) with femtosecond temporal resolution will be a transformative research tool for studying nonequilibrium chemistry and electronic dynamics of matter. Here in this article, we propose a concept of femtosecond EELS utilizing mega-electron-volt electron beams from a radio-frequency (rf) photocathode source. The high acceleration gradient and high beam energy of the rf gun are critical to the generation of 10-fs electron beams, which enables an improvement of the temporal resolution by more than 1 order of magnitude beyond the state of the art. In our proposal, the “referencebeam technique” relaxes the energy stability requirement of themore » rf power source by roughly 2 orders of magnitude. The requirements for the electron-beam quality, photocathode, spectrometer, and detector are also discussed. Supported by particle-tracking simulations, we demonstrate the feasibility of achieving subelectron- volt energy resolution and approximately 10-fs temporal resolution with existing or near-future hardware performance.« less

Profiling of integral membrane proteins and their post translational modifications using high-resolution mass spectrometry

PubMed Central

Souda, Puneet; Ryan, Christopher M.; Cramer, William A.; Whitelegge, Julian

2011-01-01

Integral membrane proteins pose challenges to traditional proteomics approaches due to unique physicochemical properties including hydrophobic transmembrane domains that limit solubility in aqueous solvents. A well resolved intact protein molecular mass profile defines a protein’s native covalent state including post-translational modifications, and is thus a vital measurement toward full structure determination. Both soluble loop regions and transmembrane regions potentially contain post-translational modifications that must be characterized if the covalent primary structure of a membrane protein is to be defined. This goal has been achieved using electrospray-ionization mass spectrometry (ESI-MS) with low-resolution mass analyzers for intact protein profiling, and high-resolution instruments for top-down experiments, toward complete covalent primary structure information. In top-down, the intact protein profile is supplemented by gas-phase fragmentation of the intact protein, including its transmembrane regions, using collisionally activated and/or electroncapture dissociation (CAD/ECD) to yield sequence-dependent high-resolution MS information. Dedicated liquid chromatography systems with aqueous/organic solvent mixtures were developed allowing us to demonstrate that polytopic integral membrane proteins are amenable to ESI-MS analysis, including top-down measurements. Covalent post-translational modifications are localized regardless of their position in transmembrane domains. Top-down measurements provide a more detail oriented high-resolution description of post-transcriptional and post-translational diversity for enhanced understanding beyond genomic translation. PMID:21982782

Profiling of integral membrane proteins and their post translational modifications using high-resolution mass spectrometry.

PubMed

Souda, Puneet; Ryan, Christopher M; Cramer, William A; Whitelegge, Julian

2011-12-01

Integral membrane proteins pose challenges to traditional proteomics approaches due to unique physicochemical properties including hydrophobic transmembrane domains that limit solubility in aqueous solvents. A well resolved intact protein molecular mass profile defines a protein's native covalent state including post-translational modifications, and is thus a vital measurement toward full structure determination. Both soluble loop regions and transmembrane regions potentially contain post-translational modifications that must be characterized if the covalent primary structure of a membrane protein is to be defined. This goal has been achieved using electrospray-ionization mass spectrometry (ESI-MS) with low-resolution mass analyzers for intact protein profiling, and high-resolution instruments for top-down experiments, toward complete covalent primary structure information. In top-down, the intact protein profile is supplemented by gas-phase fragmentation of the intact protein, including its transmembrane regions, using collisionally activated and/or electron-capture dissociation (CAD/ECD) to yield sequence-dependent high-resolution MS information. Dedicated liquid chromatography systems with aqueous/organic solvent mixtures were developed allowing us to demonstrate that polytopic integral membrane proteins are amenable to ESI-MS analysis, including top-down measurements. Covalent post-translational modifications are localized regardless of their position in transmembrane domains. Top-down measurements provide a more detail oriented high-resolution description of post-transcriptional and post-translational diversity for enhanced understanding beyond genomic translation. Copyright © 2011 Elsevier Inc. All rights reserved.

First High Resolution IR Spectra of 2-^{13}C-PROPANE. the νb{9} B-Type Band Near 366.767 \\wn and the νb{26} C-Type Band Near 746.615 \\wn. Determination of Ground and Upper State Constants.

NASA Astrophysics Data System (ADS)

Daunt, S. J.; Grzywacz, Robert; Lafferty, Walter; Flaud, Jean-Marie; Billinghurst, Brant E.

2017-06-01

This is the first report in a project to record high resolution IR data of the ^{13}C and D substituted isotopologues of propane. In this talk we will give details on the first high resolution (Δν = 0.0009 \\wn) IR investigation of 2-^{13}C-propane. Spectra of the CCC skeletal bending mode near 336.767 \\wn (B-type) and the wagging mode near 746.615 \\wn (C-type) were recorded using the FTS on the Far-IR beamline of the Canadian Light Source (CLS). The spectra were assigned both traditionally and with the aid of the PGOPHER program of Colin Western. The only available MW data on this molecule are the six K =0 J lines from Lide. We therefore had to use the present data to determine a new set of ground state constants that included centrifugal distortion terms for this molecule. We compare these experimentally determined values with the recent ab initio values of Villa, Senent & Carvajal. Upper state constants for both bands have been found that provide a good simulation of the spectra. The hope is that this data will be useful in identifying isotopic propane lines in Titan and other astrophysical objects. C. Western, J. Quant. Spectrosc. & Rad. Transf. 186, 221 ff. (2017). Lide, J.Chem. Phys. 33, p.1514ff. (1960). Villa, Senent & Carvajal, PCCP 15, 10258 (2013).

Interaction of highly charged ions with carbon nano membranes

NASA Astrophysics Data System (ADS)

Gruber, Elisabeth; Wilhelm, Richard A.; Smejkal, Valerie; Heller, René; Facsko, Stefan; Aumayr, Friedrich

2015-09-01

Charge state and energy loss measurements of slow highly charged ions (HCIs) after transmission through nanometer and sub-nanometer thin membranes are presented. Direct transmission measurements through carbon nano membranes (CNMs) show an unexpected bimodal exit charge state distribution, accompanied by charge exchange dependent energy loss. The energy loss of ions in CNMs with large charge loss shows a quadratic dependency on the incident charge state, indicating charge state dependent stopping force values. Another access to the exit charge state distribution is given by irradiating stacks of CNMs and investigating each layer of the stack with high resolution imaging techniques like transmission electron microscopy (TEM) and helium ion microscopy (HIM) independently. The observation of pores created in all of the layers confirms the assumption derived from the transmission measurements that the two separated charge state distributions reflect two different impact parameter regimes, i.e. close collision with large charge exchange and distant collisions with weak ion-target interaction.

Single-channel recordings of RyR1 at microsecond resolution in CMOS-suspended membranes.

PubMed

Hartel, Andreas J W; Ong, Peijie; Schroeder, Indra; Giese, M Hunter; Shekar, Siddharth; Clarke, Oliver B; Zalk, Ran; Marks, Andrew R; Hendrickson, Wayne A; Shepard, Kenneth L

2018-02-20

Single-channel recordings are widely used to explore functional properties of ion channels. Typically, such recordings are performed at bandwidths of less than 10 kHz because of signal-to-noise considerations, limiting the temporal resolution available for studying fast gating dynamics to greater than 100 µs. Here we present experimental methods that directly integrate suspended lipid bilayers with high-bandwidth, low-noise transimpedance amplifiers based on complementary metal-oxide-semiconductor (CMOS) integrated circuits (IC) technology to achieve bandwidths in excess of 500 kHz and microsecond temporal resolution. We use this CMOS-integrated bilayer system to study the type 1 ryanodine receptor (RyR1), a Ca 2+ -activated intracellular Ca 2+ -release channel located on the sarcoplasmic reticulum. We are able to distinguish multiple closed states not evident with lower bandwidth recordings, suggesting the presence of an additional Ca 2+ binding site, distinct from the site responsible for activation. An extended beta distribution analysis of our high-bandwidth data can be used to infer closed state flicker events as fast as 35 ns. These events are in the range of single-file ion translocations.

Evaluation of arctic multibeam sonar data quality using nadir crossover error analysis and compilation of a full-resolution data product

NASA Astrophysics Data System (ADS)

Flinders, Ashton F.; Mayer, Larry A.; Calder, Brian A.; Armstrong, Andrew A.

2014-05-01

We document a new high-resolution multibeam bathymetry compilation for the Canada Basin and Chukchi Borderland in the Arctic Ocean - United States Arctic Multibeam Compilation (USAMBC Version 1.0). The compilation preserves the highest native resolution of the bathymetric data, allowing for more detailed interpretation of seafloor morphology than has been previously possible. The compilation was created from multibeam bathymetry data available through openly accessible government and academic repositories. Much of the new data was collected during dedicated mapping cruises in support of the United States effort to map extended continental shelf regions beyond the 200 nm Exclusive Economic Zone. Data quality was evaluated using nadir-beam crossover-error statistics, making it possible to assess the precision of multibeam depth soundings collected from a wide range of vessels and sonar systems. Data were compiled into a single high-resolution grid through a vertical stacking method, preserving the highest quality data source in any specific grid cell. The crossover-error analysis and method of data compilation can be applied to other multi-source multibeam data sets, and is particularly useful for government agencies targeting extended continental shelf regions but with limited hydrographic capabilities. Both the gridded compilation and an easily distributed geospatial PDF map are freely available through the University of New Hampshire's Center for Coastal and Ocean Mapping (ccom.unh.edu/theme/law-sea). The geospatial pdf is a full resolution, small file-size product that supports interpretation of Arctic seafloor morphology without the need for specialized gridding/visualization software.

Hydrogens detected by subatomic resolution protein crystallography in a [NiFe] hydrogenase.

PubMed

Ogata, Hideaki; Nishikawa, Koji; Lubitz, Wolfgang

2015-04-23

The enzyme hydrogenase reversibly converts dihydrogen to protons and electrons at a metal catalyst. The location of the abundant hydrogens is of key importance for understanding structure and function of the protein. However, in protein X-ray crystallography the detection of hydrogen atoms is one of the major problems, since they display only weak contributions to diffraction and the quality of the single crystals is often insufficient to obtain sub-ångström resolution. Here we report the crystal structure of a standard [NiFe] hydrogenase (∼91.3 kDa molecular mass) at 0.89 Å resolution. The strictly anoxically isolated hydrogenase has been obtained in a specific spectroscopic state, the active reduced Ni-R (subform Ni-R1) state. The high resolution, proper refinement strategy and careful modelling allow the positioning of a large part of the hydrogen atoms in the structure. This has led to the direct detection of the products of the heterolytic splitting of dihydrogen into a hydride (H(-)) bridging the Ni and Fe and a proton (H(+)) attached to the sulphur of a cysteine ligand. The Ni-H(-) and Fe-H(-) bond lengths are 1.58 Å and 1.78Å, respectively. Furthermore, we can assign the Fe-CO and Fe-CN(-) ligands at the active site, and can obtain the hydrogen-bond networks and the preferred proton transfer pathway in the hydrogenase. Our results demonstrate the precise comprehensive information available from ultra-high-resolution structures of proteins as an alternative to neutron diffraction and other methods such as NMR structural analysis.

Regional sea level variability in a high-resolution global coupled climate model

NASA Astrophysics Data System (ADS)

Palko, D.; Kirtman, B. P.

2016-12-01

The prediction of trends at regional scales is essential in order to adapt to and prepare for the effects of climate change. However, GCMs are unable to make reliable predictions at regional scales. The prediction of local sea level trends is particularly critical. The main goal of this research is to utilize high-resolution (HR) (0.1° resolution in the ocean) coupled model runs of CCSM4 to analyze regional sea surface height (SSH) trends. Unlike typical, lower resolution (1.0°) GCM runs these HR runs resolve features in the ocean, like the Gulf Stream, which may have a large effect on regional sea level. We characterize the variability of regional SSH along the Atlantic coast of the US using tide gauge observations along with fixed radiative forcing runs of CCSM4 and HR interactive ensemble runs. The interactive ensemble couples an ensemble mean atmosphere with a single ocean realization. This coupling results in a 30% decrease in the strength of the Atlantic meridional overturning circulation; therefore, the HR interactive ensemble is analogous to a HR hosing experiment. By characterizing the variability in these high-resolution GCM runs and observations we seek to understand what processes influence coastal SSH along the Eastern Coast of the United States and better predict future SLR.

An operational air quality objective analysis of surface pollutants

NASA Astrophysics Data System (ADS)

Menard, R.; Robichaud, A.

2013-05-01

As of December 2012 a surface analysis of O3, PM2.5 at a resolution of 10 km over Canada and USA has become an operational product of Environment Canada. Analyses based an optimum interpolation scheme adapted to the variability of surface pollutant is run each hour. We will briefly discuss the specifics of the scheme, the technical implementation that lead to an operational implementation, a description and validation of the product as it stands today. An analysis of NO2 and a map of an air quality health index is also under way. We are now developing a high resolution analysis, 2.5 km over major cities over the Montreal-Toronto area and over the Oil sands region. The effect of state-dependent error covariance modeling will be present with some early results of the high resolutions analysis/assimilation.

Ultra-fast quantitative imaging using ptychographic iterative engine based digital micro-mirror device

NASA Astrophysics Data System (ADS)

Sun, Aihui; Tian, Xiaolin; Kong, Yan; Jiang, Zhilong; Liu, Fei; Xue, Liang; Wang, Shouyu; Liu, Cheng

2018-01-01

As a lensfree imaging technique, ptychographic iterative engine (PIE) method can provide both quantitative sample amplitude and phase distributions avoiding aberration. However, it requires field of view (FoV) scanning often relying on mechanical translation, which not only slows down measuring speed, but also introduces mechanical errors decreasing both resolution and accuracy in retrieved information. In order to achieve high-accurate quantitative imaging with fast speed, digital micromirror device (DMD) is adopted in PIE for large FoV scanning controlled by on/off state coding by DMD. Measurements were implemented using biological samples as well as USAF resolution target, proving high resolution in quantitative imaging using the proposed system. Considering its fast and accurate imaging capability, it is believed the DMD based PIE technique provides a potential solution for medical observation and measurements.

Is high-resolution inverse characterization of heterogeneous river bed hydraulic conductivities needed and possible?

NASA Astrophysics Data System (ADS)

Kurtz, W.; Hendricks Franssen, H.-J.; Brunner, P.; Vereecken, H.

2013-10-01

River-aquifer exchange fluxes influence local and regional water balances and affect groundwater and river water quality and quantity. Unfortunately, river-aquifer exchange fluxes tend to be strongly spatially variable, and it is an open research question to which degree river bed heterogeneity has to be represented in a model in order to achieve reliable estimates of river-aquifer exchange fluxes. This research question is addressed in this paper with the help of synthetic simulation experiments, which mimic the Limmat aquifer in Zurich (Switzerland), where river-aquifer exchange fluxes and groundwater management activities play an important role. The solution of the unsaturated-saturated subsurface hydrological flow problem including river-aquifer interaction is calculated for ten different synthetic realities where the strongly heterogeneous river bed hydraulic conductivities (L) are perfectly known. Hydraulic head data (100 in the default scenario) are sampled from the synthetic realities. In subsequent data assimilation experiments, where L is unknown now, the hydraulic head data are used as conditioning information, with the help of the ensemble Kalman filter (EnKF). For each of the ten synthetic realities, four different ensembles of L are tested in the experiments with EnKF; one ensemble estimates high-resolution L fields with different L values for each element, and the other three ensembles estimate effective L values for 5, 3 or 2 zones. The calibration of higher-resolution L fields (i.e. fully heterogeneous or 5 zones) gives better results than the calibration of L for only 3 or 2 zones in terms of reproduction of states, stream-aquifer exchange fluxes and parameters. Effective L for a limited number of zones cannot always reproduce the true states and fluxes well and results in biased estimates of net exchange fluxes between aquifer and stream. Also in case only 10 head data are used for conditioning, the high-resolution characterization of L fields with EnKF is still feasible. For less heterogeneous river bed hydraulic conductivities, a high-resolution characterization of L is less important. When uncertainties in the hydraulic parameters of the aquifer are also regarded in the assimilation, the errors in state and flux predictions increase, but the ensemble with a high spatial resolution for L still outperforms the ensembles with effective L values. We conclude that for strongly heterogeneous river beds the commonly applied simplified representation of the streambed, with spatially homogeneous parameters or constant parameters for a few zones, might yield significant biases in the characterization of the water balance. For strongly heterogeneous river beds, we suggest adopting a stochastic field approach to model the spatially heterogeneous river beds geostatistically. The paper illustrates that EnKF is able to calibrate such heterogeneous streambeds on the basis of hydraulic head measurements, outperforming zonation approaches.

The PMC-Turbo Balloon Mission to Study Gravity Waves and Turbulence through High-Resolution Imaging of Polar Mesospheric Clouds

NASA Astrophysics Data System (ADS)

Williams, B. P.; Kjellstrand, B.; Jones, G.; Reimuller, J. D.; Fritts, D. C.; Miller, A.; Geach, C.; Limon, M.; Hanany, S.; Kaifler, B.; Wang, L.; Taylor, M. J.

2017-12-01

PMC-Turbo is a NASA long-duration, high-altitude balloon mission that will deploy 7 high-resolution cameras to image polar mesospheric clouds (PMC) and measure gravity wave breakdown and turbulence. The mission has been enhanced by the addition of the DLR Balloon Lidar Experiment (BOLIDE) and an OH imager from Utah State University. This instrument suite will provide high horizontal and vertical resolution of the wave-modified PMC structure along a several thousand kilometer flight track. We have requested a flight from Kiruna, Sweden to Canada in June 2017 or McMurdo Base, Antarctica in Dec 2017. Three of the PMC camera systems were deployed on an aircraft and two tomographic ground sites for the High Level campaign in Canada in June/July 2017. On several nights the cameras observed PMC's with strong gravity wave breaking signatures. One PMC camera will piggyback on the Super Tiger mission scheduled to be launched in Dec 2017 from McMurdo, so we will obtain PMC images and wave/turbulence data from both the northern and southern hemispheres.

X-ray diffraction microscopy on frozen hydrated specimens

NASA Astrophysics Data System (ADS)

Nelson, Johanna

X-rays are excellent for imaging thick samples at high resolution because of their large penetration depth compared to electrons and their short wavelength relative to visible light. To image biological material, the absorption contrast of soft X-rays, especially between the carbon and oxygen K-shell absorption edges, can be utilized to give high contrast, high resolution images without the need for stains or labels. Because of radiation damage and the desire for high resolution tomography, live cell imaging is not feasible. However, cells can be frozen in vitrified ice, which reduces the effect of radiation damage while maintaining their natural hydrated state. X-ray diffraction microscopy (XDM) is an imaging technique which eliminates the limitations imposed by current focusing optics simply by removing them entirely. Far-field coherent diffraction intensity patterns are collected on a pixelated detector allowing every scattered photon to be collected within the limits of the detector's efficiency and physical size. An iterative computer algorithm is then used to invert the diffraction intensity into a real space image with both absorption and phase information. This technique transfers the emphasis away from fabrication and alignment of optics, and towards data processing. We have used this method to image a pair of freeze-dried, immuno-labeled yeast cells to the highest resolution (13 nm) yet obtained for a whole eukaryotic cell. We discuss successes and challenges in working with frozen hydrated specimens and efforts aimed at high resolution imaging of vitrified eukaryotic cells in 3D.

Chicago Classification Criteria of Esophageal Motility Disorders Defined in High Resolution Esophageal Pressure Topography (EPT)†

PubMed Central

Bredenoord, Albert J; Fox, Mark; Kahrilas, Peter J; Pandolfino, John E; Schwizer, Werner; Smout, AJPM; Conklin, Jeffrey L; Cook, Ian J; Gyawali, Prakash; Hebbard, Geoffrey; Holloway, Richard H; Ke, Meiyun; Keller, Jutta; Mittal, Ravinder K; Peters, Jeff; Richter, Joel; Roman, Sabine; Rommel, Nathalie; Sifrim, Daniel; Tutuian, Radu; Valdovinos, Miguel; Vela, Marcelo F; Zerbib, Frank

2011-01-01

Background The Chicago Classification of esophageal motility was developed to facilitate the interpretation of clinical high resolution esophageal pressure topography (EPT) studies, concurrent with the widespread adoption of this technology into clinical practice. The Chicago Classification has been, and will continue to be, an evolutionary process, molded first by published evidence pertinent to the clinical interpretation of high resolution manometry (HRM) studies and secondarily by group experience when suitable evidence is lacking. Methods This publication summarizes the state of our knowledge as of the most recent meeting of the International High Resolution Manometry Working Group in Ascona, Switzerland in April 2011. The prior iteration of the Chicago Classification was updated through a process of literature analysis and discussion. Key Results The major changes in this document from the prior iteration are largely attributable to research studies published since the prior iteration, in many cases research conducted in response to prior deliberations of the International High Resolution Manometry Working Group. The classification now includes criteria for subtyping achalasia, EGJ outflow obstruction, motility disorders not observed in normal subjects (Distal esophageal spasm, Hypercontractile esophagus, and Absent peristalsis), and statistically defined peristaltic abnormalities (Weak peristalsis, Frequent failed peristalsis, Rapid contractions with normal latency, and Hypertensive peristalsis). Conclusions & Inferences The Chicago Classification is an algorithmic scheme for diagnosis of esophageal motility disorders from clinical EPT studies. Moving forward, we anticipate continuing this process with increased emphasis placed on natural history studies and outcome data based on the classification. PMID:22248109

Chicago classification criteria of esophageal motility disorders defined in high resolution esophageal pressure topography.

PubMed

Bredenoord, A J; Fox, M; Kahrilas, P J; Pandolfino, J E; Schwizer, W; Smout, A J P M

2012-03-01

The Chicago Classification of esophageal motility was developed to facilitate the interpretation of clinical high resolution esophageal pressure topography (EPT) studies, concurrent with the widespread adoption of this technology into clinical practice. The Chicago Classification has been an evolutionary process, molded first by published evidence pertinent to the clinical interpretation of high resolution manometry (HRM) studies and secondarily by group experience when suitable evidence is lacking. This publication summarizes the state of our knowledge as of the most recent meeting of the International High Resolution Manometry Working Group in Ascona, Switzerland in April 2011. The prior iteration of the Chicago Classification was updated through a process of literature analysis and discussion. The major changes in this document from the prior iteration are largely attributable to research studies published since the prior iteration, in many cases research conducted in response to prior deliberations of the International High Resolution Manometry Working Group. The classification now includes criteria for subtyping achalasia, EGJ outflow obstruction, motility disorders not observed in normal subjects (Distal esophageal spasm, Hypercontractile esophagus, and Absent peristalsis), and statistically defined peristaltic abnormalities (Weak peristalsis, Frequent failed peristalsis, Rapid contractions with normal latency, and Hypertensive peristalsis). The Chicago Classification is an algorithmic scheme for diagnosis of esophageal motility disorders from clinical EPT studies. Moving forward, we anticipate continuing this process with increased emphasis placed on natural history studies and outcome data based on the classification. © 2012 Blackwell Publishing Ltd.

New analytical model for the ozone electronic ground state potential surface and accurate ab initio vibrational predictions at high energy range.

PubMed

Tyuterev, Vladimir G; Kochanov, Roman V; Tashkun, Sergey A; Holka, Filip; Szalay, Péter G

2013-10-07

An accurate description of the complicated shape of the potential energy surface (PES) and that of the highly excited vibration states is of crucial importance for various unsolved issues in the spectroscopy and dynamics of ozone and remains a challenge for the theory. In this work a new analytical representation is proposed for the PES of the ground electronic state of the ozone molecule in the range covering the main potential well and the transition state towards the dissociation. This model accounts for particular features specific to the ozone PES for large variations of nuclear displacements along the minimum energy path. The impact of the shape of the PES near the transition state (existence of the "reef structure") on vibration energy levels was studied for the first time. The major purpose of this work was to provide accurate theoretical predictions for ozone vibrational band centres at the energy range near the dissociation threshold, which would be helpful for understanding the very complicated high-resolution spectra and its analyses currently in progress. Extended ab initio electronic structure calculations were carried out enabling the determination of the parameters of a minimum energy path PES model resulting in a new set of theoretical vibrational levels of ozone. A comparison with recent high-resolution spectroscopic data on the vibrational levels gives the root-mean-square deviations below 1 cm(-1) for ozone band centres up to 90% of the dissociation energy. New ab initio vibrational predictions represent a significant improvement with respect to all previously available calculations.

Rotation-vibration interactions in the spectra of polycyclic aromatic hydrocarbons: Quinoline as a test-case species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pirali, O.; Gruet, S.; Institut des Sciences Moléculaires d’Orsay, UMR8214 CNRS – Université Paris-Sud, Bât. 210, 91405 Orsay cedex

2015-03-14

Polycyclic aromatic hydrocarbons (PAHs) are highly relevant for astrophysics as possible, though controversial, carriers of the unidentified infrared emission bands that are observed in a number of different astronomical objects. In support of radio-astronomical observations, high resolution laboratory spectroscopy has already provided the rotational spectra in the vibrational ground state of several molecules of this type, although the rotational study of their dense infrared (IR) bands has only recently become possible using a limited number of experimental set-ups. To date, all of the rotationally resolved data have concerned unperturbed spectra. We presently report the results of a high resolution studymore » of the three lowest vibrational states of quinoline C{sub 9}H{sub 7}N, an N-bearing naphthalene derivative. While the pure rotational ground state spectrum of quinoline is unperturbed, severe complications appear in the spectra of the ν{sub 45} and ν{sub 44} vibrational modes (located at about 168 cm{sup −1} and 178 cm{sup −1}, respectively). In order to study these effects in detail, we employed three different and complementary experimental techniques: Fourier-transform microwave spectroscopy, millimeter-wave spectroscopy, and Fourier-transform far-infrared spectroscopy with a synchrotron radiation source. Due to the high density of states in the IR spectra of molecules as large as PAHs, perturbations in the rotational spectra of excited states should be ubiquitous. Our study identifies for the first time this effect and provides some insights into an appropriate treatment of such perturbations.« less

Dynamics of molecules in extreme rotational states

PubMed Central

Yuan, Liwei; Teitelbaum, Samuel W.; Robinson, Allison; Mullin, Amy S.

2011-01-01

We have constructed an optical centrifuge with a pulse energy that is more than 2 orders of magnitude larger than previously reported instruments. This high pulse energy enables us to create large enough number densities of molecules in extreme rotational states to perform high-resolution state-resolved transient IR absorption measurements. Here we report the first studies of energy transfer dynamics involving molecules in extreme rotational states. In these studies, the optical centrifuge drives CO2 molecules into states with J ∼ 220 and we use transient IR probing to monitor the subsequent rotational, translational, and vibrational energy flow dynamics. The results reported here provide the first molecular insights into the relaxation of molecules with rotational energy that is comparable to that of a chemical bond.

Palm Swamp Wetland Ecosystems of the Upper Amazon: Characterizing their Distribution and Inundation State Using Multiple Resolution Microwave Remote Sensing

NASA Astrophysics Data System (ADS)

Podest, E.; McDonald, K. C.; Schröder, R.; Pinto, N.; Zimmermann, R.; Horna, V.

2011-12-01

Palm swamp wetlands are prevalent in the Amazon basin, including extensive regions in northern Peru. These ecosystems are characterized by constant surface inundation and moderate seasonal water level variation. The combination of constantly saturated soils, giving rise to low oxygen conditions, and warm temperatures year-round can lead to considerable methane release to the atmosphere. Because of the widespread occurrence and expected sensitivity of these ecosystems to climate change, knowledge of their spatial extent and inundation state is crucial for assessing the associated land-atmosphere carbon exchange. Precise spatio-temporal information on palm swamps is difficult to gather because of their remoteness and difficult accessibility. Spaceborne microwave remote sensing is an effective tool for characterizing these ecosystems since it is sensitive to surface water and vegetation structure and allows monitoring large inaccessible areas on a temporal basis regardless of atmospheric conditions or solar illumination. We are developing a remote sensing methodology using multiple resolution microwave remote sensing data to determine palm swamp distribution and inundation state over focus regions in the Amazon basin in northern Peru. For this purpose, two types of multi-temporal microwave data are used: 1) high-resolution (100 m) data from the Advanced Land Observing Satellite (ALOS) Phased Array L-Band Synthetic Aperture Radar (PALSAR) to derive maps of palm swamp extent and inundation from dual-polarization fine-beam and multi-temporal HH-polarized ScanSAR, and 2) coarse resolution (25 km) combined active and passive microwave data from QuikSCAT and AMSR-E to derive inundated area fraction on a weekly basis. We compare information content and accuracy of the coarse resolution products to the PALSAR-based datasets to ensure information harmonization. The synergistic combination of high and low resolution datasets will allow for characterization of palm swamps and assessment of their flooding status. This work has been undertaken partly within the framework of the JAXA ALOS Kyoto & Carbon Initiative. PALSAR data have been provided by JAXA/EORC. Portions of this work were carried out at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.

Will high-resolution global ocean models benefit coupled predictions on short-range to climate timescales?

NASA Astrophysics Data System (ADS)

Hewitt, Helene T.; Bell, Michael J.; Chassignet, Eric P.; Czaja, Arnaud; Ferreira, David; Griffies, Stephen M.; Hyder, Pat; McClean, Julie L.; New, Adrian L.; Roberts, Malcolm J.

2017-12-01

As the importance of the ocean in the weather and climate system is increasingly recognised, operational systems are now moving towards coupled prediction not only for seasonal to climate timescales but also for short-range forecasts. A three-way tension exists between the allocation of computing resources to refine model resolution, the expansion of model complexity/capability, and the increase of ensemble size. Here we review evidence for the benefits of increased ocean resolution in global coupled models, where the ocean component explicitly represents transient mesoscale eddies and narrow boundary currents. We consider lessons learned from forced ocean/sea-ice simulations; from studies concerning the SST resolution required to impact atmospheric simulations; and from coupled predictions. Impacts of the mesoscale ocean in western boundary current regions on the large-scale atmospheric state have been identified. Understanding of air-sea feedback in western boundary currents is modifying our view of the dynamics in these key regions. It remains unclear whether variability associated with open ocean mesoscale eddies is equally important to the large-scale atmospheric state. We include a discussion of what processes can presently be parameterised in coupled models with coarse resolution non-eddying ocean models, and where parameterizations may fall short. We discuss the benefits of resolution and identify gaps in the current literature that leave important questions unanswered.

Rapid orthophoto development system.

DOT National Transportation Integrated Search

2013-06-01

The DMC system procured in the project represented state-of-the-art, large-format digital aerial camera systems at the start of : project. DMC is based on the frame camera model, and to achieve large ground coverage with high spatial resolution, the ...

Abstract ID: 242 Simulation of a Fast Timing Micro-Pattern Gaseous Detector for TOF-PET.

PubMed

Radogna, Raffaella; Verwilligen, Piet

2018-01-01

Micro-Pattern Gas Detectors (MPGDs) are a new generation of gaseous detectors that have been developed thanks to advances in micro-structure technology. The main features of the MPGDs are: high rate capability (>50 MHz/cm 2 ); excellent spatial resolution (down to 50 μm); good time resolution (down to 3 ns); reduced radiation length, affordable costs, and possible flexible geometries. A new detector layout has been recently proposed that aims at combining both the high spatial resolution and high rate capability (100 MHz/cm 2 ) of the current state-of-the-art MPGDs with a high time resolution. This new type of MPGD is named the Fast Timing MPGD (FTM) detector [1,2]. The FTM developed for detecting charged particles can potentially reach sub-millimeter spatial resolution and 100 ps time resolution. This contribution introduces a Fast Timing MPGD technology optimized to detect photons, as an innovative PET imaging detector concept and emphases the importance of full detector simulation to guide the design of the detector geometry. The design and development of a new FTM, combining excellent time and spatial resolution, while exploiting the advantages of a reasonable energy resolution, will be a boost for the design of affordable TOF-PET scanner with improved image contrast. The use of such an affordable gas detector allows to instrument large areas in a cost-effective way, and to increase in image contrast for shorter scanning times (lowering the risk for the patient) and better diagnosis of the disease. In this report a dedicated simulation study is performed to optimize the detector design in the contest of the INFN project MPGD-Fatima. Results are obtained with ANSYS, COMSOL, GARFIELD++ and GEANT4 simulation tools. The final detector layout will be trade-off between fast time and good energy resolution. Copyright © 2017.

Impulsive Collision Dynamics of CO Super Rotors from an Optical Centrifuge.

PubMed

Murray, Matthew J; Ogden, Hannah M; Toro, Carlos; Liu, Qingnan; Mullin, Amy S

2016-11-18

We report state-resolved collision dynamics for CO molecules prepared in an optical centrifuge and measured with high-resolution transient IR absorption spectroscopy. Time-resolved polarization-sensitive measurements of excited CO molecules in the J=29 rotational state reveal that the oriented angular momentum of CO rotors is relaxed by impulsive collisions. The translational energy gains for molecules in the initial plane of rotation are threefold larger than for randomized angular momentum orientations, indicating the presence of anisotropic kinetic energy. The transient data show enhanced population for CO molecules in the initial plane of rotation immediately following the optical centrifuge pulse. A comparison with previous CO 2 super rotor studies illustrates the behavior of molecular gyroscopes; spatial reorientation of CO 2 J=76 rotors takes substantially longer than that for CO J=29 rotors, despite similarities in classical rotational period and rotational energy gap. High-resolution transient IR absorption measurements of the CO J=29-39 rotational states show that the collisional depopulation rates increase with J quantum number. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Prolonged Instability Prior to a Regime Shift | Science ...

EPA Pesticide Factsheets

Regime shifts are generally defined as the point of ‘abrupt’ change in the state of a system. However, a seemingly abrupt transition can be the product of a system reorganization that has been ongoing much longer than is evident in statistical analysis of a single component of the system. Using both univariate and multivariate statistical methods, we tested a long-term high-resolution paleoecological dataset with a known change in species assemblage for a regime shift. Analysis of this dataset with Fisher Information and multivariate time series modeling showed that there was a∼2000 year period of instability prior to the regime shift. This period of instability and the subsequent regime shift coincide with regional climate change, indicating that the system is undergoing extrinsic forcing. Paleoecological records offer a unique opportunity to test tools for the detection of thresholds and stable-states, and thus to examine the long-term stability of ecosystems over periods of multiple millennia. This manuscript explores various methods of assessing the transition between alternative states in an ecological system described by a long-term high-resolution paleoecological dataset.

High resolution laser spectroscopy of the [13.8]0.5 - X2Δ3/2 and [14.2]1.5 - X2Δ3/2 transitions of hafnium monofluoride (HfF)

NASA Astrophysics Data System (ADS)

Adam, A. G.; Esson, L. M.; Linton, C.; Smith, A. M.; Tokaryk, D. W.

2018-07-01

Laser-induced fluorescence (LIF) spectra of the (0, 0) and (1, 0) bands of the [13.8]0.5 - X2Δ3/2 and [14.2]1.5 - X2Δ3/2 transitions of HfF have been obtained at high resolution (∼120 MHz) using a laser ablation source. Spectra of all five isotopologues, from 180HfF to 176HfF have been clearly resolved and the two most abundant, 180HfF and 178HfF, were chosen for analysis. The rotational levels of the [13.8]0.5 state showed clear Ω - doubling closely resembling that of a 2Σ state in the v = 0 level. Irregularity in the doubling in the v = 1 level and in the isotope shift indicated a strong perturbation affecting this level. The final fit included all the previously analysed bands in the visible region and the doubling of all the Ω = 0.5 states and the isotope effect are examined and discussed.

High-Resolution Electron Energy-Loss Spectroscopy (HREELS) Using a Monochromated TEM/STEM

NASA Technical Reports Server (NTRS)

Sai, Z. R.; Bradley, J. P.; Erni, R.; Browning, N.

2005-01-01

A 200 keV FEI TF20 XT monochromated (scanning) transmission electron microscope funded by NASA's SRLIDAP program is undergoing installation at Lawrence Livermore National Laboratory. Instrument specifications in STEM mode are Cs =1.0 mm, Cc =1.2 mm, image resolution =0.18 nm, and in TEM mode Cs =1.3 mm, Cc =1.3 mm, information limit =0.14 nm. Key features of the instrument are a voltage-stabilized high tension (HT) supply, a monochromator, a high-resolution electron energy-loss spectrometer/energy filter, a high-resolution annular darkfield detector, and a solid-state x-ray energy-dispersive spectrometer. The high-tension tank contains additional sections for 60Hz and high frequency filtering, resulting in an operating voltage of 200 kV plus or minus 0.005V, a greater than 10-fold improvement over earlier systems. The monochromator is a single Wien filter design. The energy filter is a Gatan model 866 Tridiem-ERS high resolution GIF spec d for less than or equal to 0.15 eV energy resolution with 29 pA of current in a 2 nm diameter probe. 0.13 eV has already been achieved during early installation. The x-ray detector (EDAX/Genesis 4000) has a take-off angle of 20 degrees, an active area of 30 square millimeters, and a solid angle of 0.3 steradians. The higher solid angle is possible because the objective pole-piece allows the detector to be positioned as close as 9.47 mm from the specimen. The voltage-stabilized HT supply, monochromator and GIF enable high-resolution electron energy-loss spectroscopy (HREELS) with energy resolution comparable to synchrotron XANES, but with approximately 100X better spatial resolution. The region between 0 and 100 eV is called the low-loss or valence electron energy-loss spectroscopy (VEELS) region where features due to collective plasma oscillations and single electron transitions of valence electrons are observed. Most of the low-loss VEELS features we are detecting are being observed for the first time in IDPs. A major focus of our research is to understand the origin and significance of these features and how they might be exploited to gain insight about IDPs and other meteoritic materials.

Enhancing interferometer phase estimation, sensing sensitivity, and resolution using robust entangled states

NASA Astrophysics Data System (ADS)

Smith, James F.

2017-11-01

With the goal of designing interferometers and interferometer sensors, e.g., LADARs with enhanced sensitivity, resolution, and phase estimation, states using quantum entanglement are discussed. These states include N00N states, plain M and M states (PMMSs), and linear combinations of M and M states (LCMMS). Closed form expressions for the optimal detection operators; visibility, a measure of the state's robustness to loss and noise; a resolution measure; and phase estimate error, are provided in closed form. The optimal resolution for the maximum visibility and minimum phase error are found. For the visibility, comparisons between PMMSs, LCMMS, and N00N states are provided. For the minimum phase error, comparisons between LCMMS, PMMSs, N00N states, separate photon states (SPSs), the shot noise limit (SNL), and the Heisenberg limit (HL) are provided. A representative collection of computational results illustrating the superiority of LCMMS when compared to PMMSs and N00N states is given. It is found that for a resolution 12 times the classical result LCMMS has visibility 11 times that of N00N states and 4 times that of PMMSs. For the same case, the minimum phase error for LCMMS is 10.7 times smaller than that of PMMS and 29.7 times smaller than that of N00N states.

VUV spectroscopic study of the ? state of H2

NASA Astrophysics Data System (ADS)

Dickenson, G. D.; Ubachs, W.

2014-04-01

Spectral lines, probing rotational quantum states J‧ = 0, 1, 2 of the inner well vibrations (υ‧ ≤ 8) in the ? state of molecular hydrogen, were recorded in high resolution using a vacuum ultraviolet Fourier transform absorption spectrometer in the wavelength range 73-86 nm. Accurate line positions and predissociation widths are determined from a fit to the absorption spectra. Improved values for the line positions are obtained, while the predissociation widths agree well with previous investigations.

Rovibrational constants of the ground state and v8 = 1 state of 13C2HD3 by high-resolution FTIR spectroscopy

NASA Astrophysics Data System (ADS)

Ng, L. L.; Tan, T. L.

2016-06-01

The Fourier transform infrared (FTIR) spectrum of the c-type ν8 band of 13C2HD3 was recorded for the first time at a unapodized resolution of 0.0063 cm-1 in the wavenumber region of 830-1000 cm-1. Through the fitting of a total of 1057 assigned infrared transitions using Watson's A-reduced Hamiltonian in the Ir representation, rovibrational constants for the upper state (v8 = 1) up to five quartic centrifugal distortion terms were derived for the first time with a root-mean-square (rms) deviation of 0.00073 cm-1. The band center of ν8 of 13C2HD3 was found to be 913.011021(55) cm-1. Ground state rovibrational constants up to five quartic terms of 13C2HD3 were also determined from a fit of 453 ground state combination-differences from the present infrared measurements with an rms deviation of 0.00072 cm-1 for the first time. The uncertainty of the measured infrared lines was estimated to be ±0.0012 cm-1. From the ground state rotational constants, the inertial defect of 13C2HD3 was calculated to be 0.06973(16) uÅ2, showing the high planarity of the molecule.

High resolution photoelectron imaging of UO{sup −} and UO{sub 2}{sup −} and the low-lying electronic states and vibrational frequencies of UO and UO{sub 2}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Czekner, Joseph; Lopez, Gary V.; Wang, Lai-Sheng

2014-12-28

We report a study of the electronic and vibrational structures of the gaseous uranium monoxide and dioxide molecules using high-resolution photoelectron imaging. Vibrationally resolved photoelectron spectra are obtained for both UO{sup −} and UO{sub 2}{sup −}. The spectra for UO{sub 2}{sup −} are consistent with, but much better resolved than a recent study using a magnetic-bottle photoelectron analyzer [W. L. Li et al., J. Chem. Phys. 140, 094306 (2014)]. The electron affinity (EA) of UO is reported for the first time as 1.1407(7) eV, whereas a much more accurate EA is obtained for UO{sub 2} as 1.1688(6) eV. The symmetricmore » stretching modes for the neutral and anionic ground states, and two neutral excited states for UO{sub 2} are observed, as well as the bending mode for the neutral ground state. These vibrational frequencies are consistent with previous experimental and theoretical results. The stretching vibrational modes for the ground state and one excited state are observed for UO. The current results for UO and UO{sub 2} are compared with previous theoretical calculations including relativistic effects and spin-orbit coupling. The accurate experimental data reported here provide more stringent tests for future theoretical methods for actinide-containing species.« less

Highly efficient chiral resolution of DL-arginine by cocrystal formation followed by recrystallization under preferential-enrichment conditions.

PubMed

Iwama, Sekai; Kuyama, Kazunori; Mori, Yuko; Manoj, Kochunnoonny; Gonnade, Rajesh G; Suzuki, Katsuaki; Hughes, Colan E; Williams, P Andrew; Harris, Kenneth D M; Veesler, Stéphane; Takahashi, Hiroki; Tsue, Hirohito; Tamura, Rui

2014-08-11

An excellent chiral symmetry-breaking spontaneous enantiomeric resolution phenomenon, denoted preferential enrichment, was observed on recrystallization of the 1:1 cocrystal of dl-arginine and fumaric acid, which is classified as a racemic compound crystal with a high eutectic ee value (>95 %), under non-equilibrium crystallization conditions. On the basis of temperature-controlled video microscopy and in situ time-resolved solid-state (13) C NMR spectroscopic studies on the crystallization process, a new mechanism of phase transition that can induce preferential enrichment is proposed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In situ calibration of a high-resolution gamma-ray borehole sonde for assaying uranium-bearing sandstone deposits

USGS Publications Warehouse

Day, J.H.

1985-01-01

A method is presented for assaying radioactive sandstone deposits in situ by using a high-resolution borehole gamma-ray spectrometer. Gamma-ray photopeaks from the same spectrum acquired to analyze a sample are used to characterize gamma-ray attenuation properties, from which a calibration function is determined. Assay results are independent of differences between properties of field samples and those of laboratory or test-hole standards generally used to calibrate a borehole sonde. This assaying technique is also independent of the state of radioactive disequilibrium that usually exists in nature among members of the natural-decay chains. ?? 1985.

Nondestructive laboratory measurement of geotechnical and geoacoustic properties through intact core-liner

USGS Publications Warehouse

Kayen, R.E.; Edwards, B.D.; Lee, H.J.

1999-01-01

High-resolution automated measurement of the geotechnical and geoacoustic properties of soil at the U.S. Geological Survey (USGS) is performed with a state-of-the-art multi-sensor whole-core logging device. The device takes measurements, directly through intact sample-tube wall, of p-wave acoustic velocity, of soil wet bulk density, and magnetic susceptibility. This paper summarizes our methodology for determining soil-sound speed and wet-bulk density for material encased in an unsplit liner. Our methodology for nondestructive measurement allows for rapid, accurate, and high-resolution (1 cm-spaced) mapping of the mass physical properties of soil prior to sample extrusion.

Design, construction, and evaluation of new high resolution medical imaging detector/systems

NASA Astrophysics Data System (ADS)

Jain, Amit

Increasing need of minimally invasive endovascular image guided interventional procedures (EIGI) for accurate and successful treatment of vascular disease has set a quest for better image quality. Current state of the art detectors are not up to the mark for these complex procedures due to their inherent limitations. Our group has been actively working on the design and construction of a high resolution, region of interest CCD-based X-ray imager for some time. As a part of that endeavor, a Micro-angiographic fluoroscope (MAF) was developed to serve as a high resolution, ROI X-ray imaging detector in conjunction with large lower resolution full field of view (FOV) state-of-the-art x-ray detectors. The newly developed MAF is an indirect x-ray imaging detector capable of providing real-time images with high resolution, high sensitivity, no lag and low instrumentation noise. It consists of a CCD camera coupled to a light image intensifier (LII) through a fiber optic taper. The CsI(Tl) phosphor serving as the front end is coupled to the LII. For this work, the MAF was designed and constructed. The linear system cascade theory was used to evaluate the performance theoretically. Linear system metrics such as MTF and DQE were used to gauge the detector performance experimentally. The capabilities of the MAF as a complete system were tested using generalized linear system metrics. With generalized linear system metrics the effects of finite size focal spot, geometric magnification and the presence of scatter are included in the analysis and study. To minimize the effect of scatter, an anti-scatter grid specially designed for the MAF was also studied. The MAF was compared with the flat panel detector using signal-to-noise ratio and the two dimensional linear system metrics. The signal-to-noise comparison was carried out to point out the effect of pixel size and Point Spread Function of the detector. The two dimensional linear system metrics were used to investigate the comparative performance of both the detectors in similar simulated clinical neuro-vascular conditions. The last part of this work presents a unique quality of the MAF: operation in single photon mode. The successful operation of the MAF was demonstrated with considerable improvement in spatial and contrast resolution over conventional energy integrating mode. The work presented shows the evolution of a high resolution, high sensitivity, and region of interest x-ray imaging detector as an attractive and capable x-ray imager for the betterment of complex EIGI procedures. The capability of single photon counting mode imaging provides the potential for additional uses of the MAF including the possibility of use in dual modality imaging with radionuclide sources as well as x-rays.

Probing defect states in polycrystalline GaN grown on Si(111) by sub-bandgap laser-excited scanning tunneling spectroscopy

NASA Astrophysics Data System (ADS)

Hsiao, F.-M.; Schnedler, M.; Portz, V.; Huang, Y.-C.; Huang, B.-C.; Shih, M.-C.; Chang, C.-W.; Tu, L.-W.; Eisele, H.; Dunin-Borkowski, R. E.; Ebert, Ph.; Chiu, Y.-P.

2017-01-01

We demonstrate the potential of sub-bandgap laser-excited cross-sectional scanning tunneling microscopy and spectroscopy to investigate the presence of defect states in semiconductors. The characterization method is illustrated on GaN layers grown on Si(111) substrates without intentional buffer layers. According to high-resolution transmission electron microscopy and cathodoluminescence spectroscopy, the GaN layers consist of nanoscale wurtzite and zincblende crystallites with varying crystal orientations and hence contain high defect state densities. In order to discriminate between band-to-band excitation and defect state excitations, we use sub-bandgap laser excitation. We probe a clear increase in the tunnel current at positive sample voltages during sub-bandgap laser illumination for the GaN layer with high defect density, but no effect is found for high quality GaN epitaxial layers. This demonstrates the excitation of free charge carriers at defect states. Thus, sub-bandgap laser-excited scanning tunneling spectroscopy is a powerful complimentary characterization tool for defect states.

X-ray Free Electron Laser Determination of Crystal Structures of Dark and Light States of a Reversibly Photoswitching Fluorescent Protein at Room Temperature

PubMed Central

Hutchison, Christopher D. M.; Cordon-Preciado, Violeta; Morgan, Rhodri M. L.; Dorlhiac, Gabriel; Sanchez-Gonzalez, Alvaro; Fitzpatrick, Ann; Fare, Clyde; Marangos, Jon P.; Hunter, Mark S.; DePonte, Daniel P.; Boutet, Sébastien; Owada, Shigeki; Tanaka, Rie; Tono, Kensuke; Iwata, So; van Thor, Jasper J.

2017-01-01

The photochromic fluorescent protein Skylan-NS (Nonlinear Structured illumination variant mEos3.1H62L) is a reversibly photoswitchable fluorescent protein which has an unilluminated/ground state with an anionic and cis chromophore conformation and high fluorescence quantum yield. Photo-conversion with illumination at 515 nm generates a meta-stable intermediate with neutral trans-chromophore structure that has a 4 h lifetime. We present X-ray crystal structures of the cis (on) state at 1.9 Angstrom resolution and the trans (off) state at a limiting resolution of 1.55 Angstrom from serial femtosecond crystallography experiments conducted at SPring-8 Angstrom Compact Free Electron Laser (SACLA) at 7.0 keV and 10.5 keV, and at Linac Coherent Light Source (LCLS) at 9.5 keV. We present a comparison of the data reduction and structure determination statistics for the two facilities which differ in flux, beam characteristics and detector technologies. Furthermore, a comparison of droplet on demand, grease injection and Gas Dynamic Virtual Nozzle (GDVN) injection shows no significant differences in limiting resolution. The photoconversion of the on- to the off-state includes both internal and surface exposed protein structural changes, occurring in regions that lack crystal contacts in the orthorhombic crystal form. PMID:28880248

Estimating NOx emissions and surface concentrations at high spatial resolution using OMI

NASA Astrophysics Data System (ADS)

Goldberg, D. L.; Lamsal, L. N.; Loughner, C.; Swartz, W. H.; Saide, P. E.; Carmichael, G. R.; Henze, D. K.; Lu, Z.; Streets, D. G.

2017-12-01

In many instances, NOx emissions are not measured at the source. In these cases, remote sensing techniques are extremely useful in quantifying NOx emissions. Using an exponential modified Gaussian (EMG) fitting of oversampled Ozone Monitoring Instrument (OMI) NO2 data, we estimate NOx emissions and lifetimes in regions where these emissions are uncertain. This work also presents a new high-resolution OMI NO2 dataset derived from the NASA retrieval that can be used to estimate surface level concentrations in the eastern United States and South Korea. To better estimate vertical profile shape factors, we use high-resolution model simulations (Community Multi-scale Air Quality (CMAQ) and WRF-Chem) constrained by in situ aircraft observations to re-calculate tropospheric air mass factors and tropospheric NO2 vertical columns during summertime. The correlation between our satellite product and ground NO2 monitors in urban areas has improved dramatically: r2 = 0.60 in new product, r2 = 0.39 in operational product, signifying that this new product is a better indicator of surface concentrations than the operational product. Our work emphasizes the need to use both high-resolution and high-fidelity models in order to re-calculate vertical column data in areas with large spatial heterogeneities in NOx emissions. The methodologies developed in this work can be applied to other world regions and other satellite data sets to produce high-quality region-specific emissions estimates.

State-of-the-art for large area high resolution gray scale and full color AC plasma flat panel displays

NASA Technical Reports Server (NTRS)

Stoller, Ray A.; Wedding, Donald K.; Friedman, Peter S.

1993-01-01

A development status evaluation is presented for gas plasma display technology, noting how tradeoffs among the parameters of size, resolution, speed, portability, color, and image quality can yield cost-effective solutions for medical imaging, CAD, teleconferencing, multimedia, and both civil and military applications. Attention is given to plasma-based large-area displays' suitability for radar, sonar, and IR, due to their lack of EM susceptibility. Both monochrome and color displays are available.

Committee Meeting of Assembly Education Committee "To Receive Testimony from the Commissioner of Education, Mary Lee Fitzgerald, Department Staff, and Others Concerning the Department's Skills Testing Program, Including the Early Warning Test and High School Proficiency Test, Pursuant to Assembly Resolution No. 113."

ERIC Educational Resources Information Center

New Jersey State Office of Legislative Services, Trenton. Assembly Education Committee.

The Assembly Education Committee of the New Jersey Office of Legislative Services held a hearing pursuant to Assembly Resolution 113, a proposal directing the Committee to investigate the skills testing program developed and administered to New Jersey children by the State Department of Education. The Committee was interested in the eighth-grade…

Two-color CW STED nanoscopy

NASA Astrophysics Data System (ADS)

Chen, Xuanze; Liu, Yujia; Yang, Xusan; Wang, Tingting; Alonas, Eric; Santangelo, Philip J.; Ren, Qiushi; Xi, Peng

2013-02-01

Fluorescent microscopy has become an essential tool to study biological molecules, pathways and events in living cells, tissues and animals. Meanwhile even the most advanced confocal microscopy can only yield optical resolution approaching Abbe diffraction limit of 200 nm. This is still larger than many subcellular structures, which are too small to be resolved in detail. These limitations have driven the development of super-resolution optical imaging methodologies over the past decade. In stimulated emission depletion (STED) microscopy, the excitation focus is overlapped by an intense doughnut-shaped spot to instantly de-excite markers from their fluorescent state to the ground state by stimulated emission. This effectively eliminates the periphery of the Point Spread Function (PSF), resulting in a narrower focal region, or super-resolution. Scanning a sharpened spot through the specimen renders images with sub-diffraction resolution. Multi-color STED imaging can present important structural and functional information for protein-protein interaction. In this work, we presented a two-color, synchronization-free STED microscopy with a Ti:Sapphire oscillator. The excitation wavelengths were 532nm and 635nm, respectively. With pump power of 4.6 W and sample irradiance of 310 mW, we achieved super-resolution as high as 71 nm. Human respiratory syncytial virus (hRSV) proteins were imaged with our two-color CW STED for co-localization analysis.

An ultrafast angle-resolved photoemission apparatus for measuring complex materials

NASA Astrophysics Data System (ADS)

Smallwood, Christopher L.; Jozwiak, Christopher; Zhang, Wentao; Lanzara, Alessandra

2012-12-01

We present technical specifications for a high resolution time- and angle-resolved photoemission spectroscopy setup based on a hemispherical electron analyzer and cavity-dumped solid state Ti:sapphire laser used to generate pump and probe beams, respectively, at 1.48 and 5.93 eV. The pulse repetition rate can be tuned from 209 Hz to 54.3 MHz. Under typical operating settings the system has an overall energy resolution of 23 meV, an overall momentum resolution of 0.003 Å-1, and an overall time resolution of 310 fs. We illustrate the system capabilities with representative data on the cuprate superconductor Bi2Sr2CaCu2O8+δ. The descriptions and analyses presented here will inform new developments in ultrafast electron spectroscopy.

New materials for high-energy-resolution x-ray optics

DOE PAGES

Yavas, Hasan; Sutter, John P.; Gog, Thomas; ...

2017-06-09

The use of crystals other than silicon for x-ray optics is becoming more common for many challenging experiments such as resonant inelastic x-ray scattering and nuclear resonant scattering. As more—and more specialized—spectrometers become available at many synchrotron radiation facilities, interest in pushing the limits of experimental energy resolution has increased. The potentially large improvements in resolution and efficiency that nonsilicon optics offer are beginning to be realized. Furthermore, this article covers the background and state of the art for nonsilicon crystal optics with a focus on a resolution of 10 meV or better, concentrating on compounds that form trigonal crystals,more » including sapphire, quartz, and lithium niobate, rather than the more conventional cubic materials, including silicon, diamond, and germanium.« less

Climate and climate variability of the wind power resources in the Great Lakes region of the United States

Treesearch

X. Li; S. Zhong; X. Bian; W.E. Heilman

2010-01-01

The climate and climate variability of low-level winds over the Great Lakes region of the United States is examined using 30 year (1979-2008) wind records from the recently released North American Regional Reanalysis (NARR), a three-dimensional, high-spatial and temporal resolution, and dynamically consistent climate data set. The analyses focus on spatial distribution...

Shape indexes for semi-automated detection of windbreaks in thematic tree cover maps from the central United States

Treesearch

Greg C. Liknes; Dacia M. Meneguzzo; Todd A. Kellerman

2017-01-01

Windbreaks are an important ecological resource across the large expanse of agricultural land in the central United States and are often planted in straight-line or L-shaped configurations to serve specific functions. As high-resolution (i.e., <5 m) land cover datasets become more available for these areas, semi-or fully-automated methods for distinguishing...

Delineating pMDI model reactions with loblolly pine via solution-state NMR spectroscopy. Part 2, Non-catalyzed reactions with the wood cell wall

Treesearch

Daniel J. Yelle; John Ralph; Charles R. Frihart

2011-01-01

Solution-state NMR provides a powerful tool to observe the presence or absence of covalent bonds between wood and adhesives. Finely ground wood can be dissolved in an NMR compatible solvent system containing dimethylsulfoxide-d6 and N-methylimidazole-d6, in which the wood polymers remain largely intact. High-resolution...

Capability of AVHRR data in discriminating rangeland cover mixtures

USGS Publications Warehouse

Senay, Gabriel B.; Elliott, R.L.

2002-01-01

A combination of high temporal resolution Advanced Very High Resolution Radiometer (AVHRR) data and high spatial information Map Information Analysis and Display System (MIADS) landuse/landcover data from the United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS) were used to investigate the feasibility of using the combined dataset for regional evapotranspiration (ET) studies. It was shown that the biweekly maximum Normalized Difference Vegetation Index (NDVI) composite AVHRR data were capable of discriminating rangelands with different types of trees and shrubs species. AVHRR data also showed a potential to distinguish canopy cover differences within a mix of similar species. The combination of MIADS data and AVHRR data can be used to study temporal dynamics of various cover types for use in regional ET estimates.

High-precision shape representation using a neuromorphic vision sensor with synchronous address-event communication interface

NASA Astrophysics Data System (ADS)

Belbachir, A. N.; Hofstätter, M.; Litzenberger, M.; Schön, P.

2009-10-01

A synchronous communication interface for neuromorphic temporal contrast vision sensors is described and evaluated in this paper. This interface has been designed for ultra high-speed synchronous arbitration of a temporal contrast image sensors pixels' data. Enabling high-precision timestamping, this system demonstrates its uniqueness for handling peak data rates and preserving the main advantage of the neuromorphic electronic systems, that is high and accurate temporal resolution. Based on a synchronous arbitration concept, the timestamping has a resolution of 100 ns. Both synchronous and (state-of-the-art) asynchronous arbiters have been implemented in a neuromorphic dual-line vision sensor chip in a standard 0.35 µm CMOS process. The performance analysis of both arbiters and the advantages of the synchronous arbitration over asynchronous arbitration in capturing high-speed objects are discussed in detail.

Optimization of offsets and cycle length using high resolution signal event data.

DOT National Transportation Integrated Search

2011-01-01

Traffic signal systems represent a substantial component of the highway transportation network in the United States. It is challenging for most agencies to find engineering resources to properly update signal policies and timing plans to accommodate ...

Identifying species from the air: UAVs and the very high resolution challenge for plant conservation

PubMed Central

Moat, Justin; Whaley, Oliver; Boyd, Doreen S.

2017-01-01

The Pacific Equatorial dry forest of Northern Peru is recognised for its unique endemic biodiversity. Although highly threatened the forest provides livelihoods and ecosystem services to local communities. As agro-industrial expansion and climatic variation transform the region, close ecosystem monitoring is essential for viable adaptation strategies. UAVs offer an affordable alternative to satellites in obtaining both colour and near infrared imagery to meet the specific requirements of spatial and temporal resolution of a monitoring system. Combining this with their capacity to produce three dimensional models of the environment provides an invaluable tool for species level monitoring. Here we demonstrate that object-based image analysis of very high resolution UAV images can identify and quantify keystone tree species and their health across wide heterogeneous landscapes. The analysis exposes the state of the vegetation and serves as a baseline for monitoring and adaptive implementation of community based conservation and restoration in the area. PMID:29176860

Rapid mapping of polarization switching through complete information acquisition

DOE PAGES

Somnath, Suhas; Belianinov, Alex; Kalinin, Sergei V.; ...

2016-12-02

Polarization switching in ferroelectric and multiferroic materials underpins a broad range of current and emergent applications, ranging from random access memories to field-effect transistors, and tunnelling devices. Switching in these materials is exquisitely sensitive to local defects and microstructure on the nanometre scale, necessitating spatially resolved high-resolution studies of these phenomena. Classical piezoresponse force microscopy and spectroscopy, although providing necessary spatial resolution, are fundamentally limited in data acquisition rates and energy resolution. This limitation stems from their two-tiered measurement protocol that combines slow (~1 s) switching and fast (~10 kHz–1 MHz) detection waveforms. Here we develop an approach for rapidmore » probing of ferroelectric switching using direct strain detection of material response to probe bias. This approach, facilitated by high-sensitivity electronics and adaptive filtering, enables spectroscopic imaging at a rate 3,504 times faster the current state of the art, achieving high-veracity imaging of polarization dynamics in complex microstructures.« less

Monitoring black-tailed prairie dog colonies with high-resolution satellite imagery

USGS Publications Warehouse

Sidle, John G.; Johnson, D.H.; Euliss, B.R.; Tooze, M.

2002-01-01

The United States Fish and Wildlife Service has determined that the black-tailed prairie dog (Cynomys ludovicianus) warrants listing as a threatened species under the Endangered Species Act. Central to any conservation planning for the black-tailed prairie dog is an appropriate detection and monitoring technique. Because coarse-resolution satellite imagery is not adequate to detect black-tailed prairie dog colonies, we examined the usefulness of recently available high-resolution (1-m) satellite imagery. In 6 purchased scenes of national grasslands, we were easily able to visually detect small and large colonies without using image-processing algorithms. The Ikonos (Space Imaging(tm)) satellite imagery was as adequate as large-scale aerial photography to delineate colonies. Based on the high quality of imagery, we discuss a possible monitoring program for black-tailed prairie dog colonies throughout the Great Plains, using the species' distribution in North Dakota as an example. Monitoring plots could be established and imagery acquired periodically to track the expansion and contraction of colonies.

Perfect Composition Depth Profiling of Ionic Liquid Surfaces Using High-resolution RBS/ERDA.

PubMed

Nakajima, Kaoru; Zolboo, Enkhbayar; Ohashi, Tomohiro; Lísal, Martin; Kimura, Kenji

2016-01-01

In order to reveal the surface structures of large molecular ionic liquids (ILs), the near-surface elemental depth distributions of 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C n C 1 Im][Tf 2 N], n = 2, 6, 10) were studied using high-resolution Rutherford backscattering spectroscopy (HRBS) in combination with high-resolution elastic recoil detection analysis (HR-ERDA). The elemental depth profiles of all constituent elements, including hydrogen, were derived from HR-ERDA/HRBS measurements, so that the profiles would reproduce both HR-ERDA and HRBS spectra simultaneously. The derived elemental depth profiles agree with state-of-the-art molecular dynamics simulations, indicating the feasibility of this method. A controversy concerning the preferential orientation of [C 2 C 1 Im] at the surface has been resolved by this new combination analysis; namely, the [C 2 C 1 Im] cation has a preferential orientation with the ethyl chain pointing towards the vacuum in the topmost molecular layer.

Direct observation of charged domain walls in hybrid improper ferroelectric (Ca,Sr)3Ti2O7

NASA Astrophysics Data System (ADS)

Kurushima, Kousuke; Yoshimoto, Wataru; Ishii, Yui; Cheong, Sang-Wook; Mori, Shigeo

2017-10-01

We investigated ferroelectric (FE) domain wall structures including “charged domain walls” of hybrid improper FE (Ca,Sr)3Ti2O7 at the subatomic resolution by dark-field transmission electron microscopy (TEM) and high-resolution state-of-the-art aberration-corrected high-angle annular-dark-field (HAADF) scanning transmission electron microscopy (STEM). Dark-field TEM and high-resolution HAADF-STEM images obtained in the FE phase of single crystals of Ca2.46Sr0.54Ti2O7 revealed the formation of abundant charged domain walls with the head-to-head and tail-to-tail configurations in the FE domain structure, in addition to the FE 180° domain structure. The charged domain walls with the head-to-head and tail-to-tail FE polarizations exist stably and can be characterized as the unique double arc-type displacement of Ca/Sr ions in a unit cell without charge accumulation.

Rapid mapping of polarization switching through complete information acquisition

PubMed Central

Somnath, Suhas; Belianinov, Alex; Kalinin, Sergei V.; Jesse, Stephen

2016-01-01

Polarization switching in ferroelectric and multiferroic materials underpins a broad range of current and emergent applications, ranging from random access memories to field-effect transistors, and tunnelling devices. Switching in these materials is exquisitely sensitive to local defects and microstructure on the nanometre scale, necessitating spatially resolved high-resolution studies of these phenomena. Classical piezoresponse force microscopy and spectroscopy, although providing necessary spatial resolution, are fundamentally limited in data acquisition rates and energy resolution. This limitation stems from their two-tiered measurement protocol that combines slow (∼1 s) switching and fast (∼10 kHz–1 MHz) detection waveforms. Here we develop an approach for rapid probing of ferroelectric switching using direct strain detection of material response to probe bias. This approach, facilitated by high-sensitivity electronics and adaptive filtering, enables spectroscopic imaging at a rate 3,504 times faster the current state of the art, achieving high-veracity imaging of polarization dynamics in complex microstructures. PMID:27910941

High-angular-resolution stellar imaging with occultations from the Cassini spacecraft - III. Mira

NASA Astrophysics Data System (ADS)

Stewart, Paul N.; Tuthill, Peter G.; Nicholson, Philip D.; Hedman, Matthew M.

2016-04-01

We present an analysis of spectral and spatial data of Mira obtained by the Cassini spacecraft, which not only observed the star's spectra over a broad range of near-infrared wavelengths, but was also able to obtain high-resolution spatial information by watching the star pass behind Saturn's rings. The observed spectral range of 1-5 microns reveals the stellar atmosphere in the crucial water-bands which are unavailable to terrestrial observers, and the simultaneous spatial sampling allows the origin of spectral features to be located in the stellar environment. Models are fitted to the data, revealing the spectral and spatial structure of molecular layers surrounding the star. High-resolution imagery is recovered revealing the layered and asymmetric nature of the stellar atmosphere. The observational data set is also used to confront the state-of-the-art cool opacity-sampling dynamic extended atmosphere models of Mira variables through a detailed spectral and spatial comparison, revealing in general a good agreement with some specific departures corresponding to particular spectral features.

Capabilities and prospects of the East Asia Very Long Baseline Interferometry Network

NASA Astrophysics Data System (ADS)

An, T.; Sohn, B. W.; Imai, H.

2018-02-01

The very long baseline interferometry (VLBI) technique offers angular resolutions superior to any other instruments at other wavelengths, enabling unique science applications of high-resolution imaging of radio sources and high-precision astrometry. The East Asia VLBI Network (EAVN) is a collaborative effort in the East Asian region. The EAVN currently consists of 21 telescopes with diverse equipment configurations and frequency setups, allowing flexible subarrays for specific science projects. The EAVN provides the highest resolution of 0.5 mas at 22 GHz, allowing the fine imaging of jets in active galactic nuclei, high-accuracy astrometry of masers and pulsars, and precise spacecraft positioning. The soon-to-be-operational Five-hundred-meter Aperture Spherical radio Telescope (FAST) will open a new era for the EAVN. This state-of-the-art VLBI array also provides easy access to and crucial training for the burgeoning Asian astronomical community. This Perspective summarizes the status, capabilities and prospects of the EAVN.

The Next-generation Berkeley High Resolution NO2 (BEHR NO2) Retrieval: Design and Preliminary Emissions Constraints

NASA Astrophysics Data System (ADS)

Laughner, J.; Cohen, R. C.

2017-12-01

Recent work has identified a number of assumptions made in NO2 retrievals that lead to biases in the retrieved NO2 column density. These include the treatment of the surface as an isotropic reflector, the absence of lightning NO2 in high resolution a priori profiles, and the use of monthly averaged a priori profiles. We present a new release of the Berkeley High Resolution (BEHR) OMI NO2 retrieval based on the new NASA Standard Product (version 3) that addresses these assumptions by: accounting for surface anisotropy by using a BRDF albedo product, using an updated method of regridding NO2 data, and revised NO2 a priori profiles that better account for lightning NO2 and daily variation in the profile shape. We quantify the effect these changes have on the retrieved NO2 column densities and the resultant impact these updates have on constraints of urban NOx emissions for select cities throughout the United States.

Bound States and Field-Polarized Haldane Modes in a Quantum Spin Ladder.

PubMed

Ward, S; Mena, M; Bouillot, P; Kollath, C; Giamarchi, T; Schmidt, K P; Normand, B; Krämer, K W; Biner, D; Bewley, R; Guidi, T; Boehm, M; McMorrow, D F; Rüegg, Ch

2017-04-28

The challenge of one-dimensional systems is to understand their physics beyond the level of known elementary excitations. By high-resolution neutron spectroscopy in a quantum spin-ladder material, we probe the leading multiparticle excitation by characterizing the two-magnon bound state at zero field. By applying high magnetic fields, we create and select the singlet (longitudinal) and triplet (transverse) excitations of the fully spin-polarized ladder, which have not been observed previously and are close analogs of the modes anticipated in a polarized Haldane chain. Theoretical modeling of the dynamical response demonstrates our complete quantitative understanding of these states.

High-resolution spectroscopy of the C-N stretching band of methylamine

NASA Astrophysics Data System (ADS)

Lees, Ronald M.; Sun, Zhen-Dong; Billinghurst, B. E.

2011-09-01

The C-N stretching infrared fundamental of CH3NH2 has been investigated by high-resolution laser sideband and Fourier transform synchrotron spectroscopy to explore the energy level structure and to look for possible interactions with high-lying torsional levels of the ground state and other vibrational modes. The spectrum is complicated by two coupled large-amplitude motions in the molecule, the CH3 torsion and the NH2 inversion, which lead to rich spectral structure with a wide range of energy level splittings and relative line intensities. Numerous sub-bands have been assigned for K values ranging up to 12 for the stronger a inversion species for the vt = 0 torsional state, along with many of the weaker sub-bands of the s species. The C-N stretching sub-state origins have been determined by fitting the upper-state term values to J(J + 1) power-series expansions. For comparison with the ground-state behaviour, both ground and C-N stretch origins have been fitted to a phenomenological Fourier series model that produces an interesting pattern with the differing periodicities of the torsional and inversion energies. The amplitude of the torsional energy oscillation increases substantially for the C-N stretch, while the amplitude of the inversion energy oscillation is relatively unchanged. Independent inertial scale factors ρ were fitted for the torsion and the inversion and differ significantly in the upper state. The C-N stretching vibrational energy is determined to be 1044.817 cm-1, while the effective upper state B-value is 0.7318 cm-1. Several anharmonic resonances with vt = 4 ground-state levels have been observed and partially characterized. A variety of J-localized level-crossing resonances have also been seen, five of which display forbidden transitions arising from intensity borrowing that allow determination of the interaction coupling constants.

High resolution land surface response of inland moving Indian monsoon depressions over Bay of Bengal

NASA Astrophysics Data System (ADS)

Rajesh, P. V.; Pattnaik, S.

2016-05-01

During Indian summer monsoon (ISM) season, nearly about half of the monsoonal rainfall is brought inland by the low pressure systems called as Monsoon Depressions (MDs). These systems bear large amount of rainfall and frequently give copious amount of rainfall over land regions, therefore accurate forecast of these synoptic scale systems at short time scale can help in disaster management, flood relief, food safety. The goal of this study is to investigate, whether an accurate moisture-rainfall feedback from land surface can improve the prediction of inland moving MDs. High Resolution Land Data Assimilation System (HRLDAS) is used to generate improved land state .i.e. soil moisture and soil temperature profiles by means of NOAH-MP land-surface model. Validation of the model simulated basic atmospheric parameters at surface layer and troposphere reveals that the incursion of high resolution land state yields least Root Mean Squared Error (RMSE) with a higher correlation coefficient and facilitates accurate depiction of MDs. Rainfall verification shows that HRLDAS simulations are spatially and quantitatively in more agreement with the observations and the improved surface characteristics could result in the realistic reproduction of the storm spatial structure, movement as well as intensity. These results signify the necessity of investigating more into the land surface-rainfall feedbacks through modifications in moisture flux convergence within the storm.

Mapping whole-brain activity with cellular resolution by light-sheet microscopy and high-throughput image analysis (Conference Presentation)

NASA Astrophysics Data System (ADS)

Silvestri, Ludovico; Rudinskiy, Nikita; Paciscopi, Marco; Müllenbroich, Marie Caroline; Costantini, Irene; Sacconi, Leonardo; Frasconi, Paolo; Hyman, Bradley T.; Pavone, Francesco S.

2016-03-01

Mapping neuronal activity patterns across the whole brain with cellular resolution is a challenging task for state-of-the-art imaging methods. Indeed, despite a number of technological efforts, quantitative cellular-resolution activation maps of the whole brain have not yet been obtained. Many techniques are limited by coarse resolution or by a narrow field of view. High-throughput imaging methods, such as light sheet microscopy, can be used to image large specimens with high resolution and in reasonable times. However, the bottleneck is then moved from image acquisition to image analysis, since many TeraBytes of data have to be processed to extract meaningful information. Here, we present a full experimental pipeline to quantify neuronal activity in the entire mouse brain with cellular resolution, based on a combination of genetics, optics and computer science. We used a transgenic mouse strain (Arc-dVenus mouse) in which neurons which have been active in the last hours before brain fixation are fluorescently labelled. Samples were cleared with CLARITY and imaged with a custom-made confocal light sheet microscope. To perform an automatic localization of fluorescent cells on the large images produced, we used a novel computational approach called semantic deconvolution. The combined approach presented here allows quantifying the amount of Arc-expressing neurons throughout the whole mouse brain. When applied to cohorts of mice subject to different stimuli and/or environmental conditions, this method helps finding correlations in activity between different neuronal populations, opening the possibility to infer a sort of brain-wide 'functional connectivity' with cellular resolution.

Three-dimensional localization of nanoscale battery reactions using soft X-ray tomography

DOE PAGES

Yu, Young-Sang; Farmand, Maryam; Kim, Chunjoong; ...

2018-03-02

Battery function is determined by the efficiency and reversibility of the electrochemical phase transformations at solid electrodes. The microscopic tools available to study the chemical states of matter with the required spatial resolution and chemical specificity are intrinsically limited when studying complex architectures by their reliance on two-dimensional projections of thick material. Here in this paper, we report the development of soft X-ray ptychographic tomography, which resolves chemical states in three dimensions at 11 nm spatial resolution. We study an ensemble of nano-plates of lithium iron phosphate extracted from a battery electrode at 50% state of charge. Using a setmore » of nanoscale tomograms, we quantify the electrochemical state and resolve phase boundaries throughout the volume of individual nanoparticles. These observations reveal multiple reaction points, intra-particle heterogeneity, and size effects that highlight the importance of multi-dimensional analytical tools in providing novel insight to the design of the next generation of high-performance devices.« less

Three-dimensional localization of nanoscale battery reactions using soft X-ray tomography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yu, Young-Sang; Farmand, Maryam; Kim, Chunjoong

Battery function is determined by the efficiency and reversibility of the electrochemical phase transformations at solid electrodes. The microscopic tools available to study the chemical states of matter with the required spatial resolution and chemical specificity are intrinsically limited when studying complex architectures by their reliance on two-dimensional projections of thick material. Here in this paper, we report the development of soft X-ray ptychographic tomography, which resolves chemical states in three dimensions at 11 nm spatial resolution. We study an ensemble of nano-plates of lithium iron phosphate extracted from a battery electrode at 50% state of charge. Using a setmore » of nanoscale tomograms, we quantify the electrochemical state and resolve phase boundaries throughout the volume of individual nanoparticles. These observations reveal multiple reaction points, intra-particle heterogeneity, and size effects that highlight the importance of multi-dimensional analytical tools in providing novel insight to the design of the next generation of high-performance devices.« less

Ultrafast quantum control of ionization dynamics in krypton.

PubMed

Hütten, Konrad; Mittermair, Michael; Stock, Sebastian O; Beerwerth, Randolf; Shirvanyan, Vahe; Riemensberger, Johann; Duensing, Andreas; Heider, Rupert; Wagner, Martin S; Guggenmos, Alexander; Fritzsche, Stephan; Kabachnik, Nikolay M; Kienberger, Reinhard; Bernhardt, Birgitta

2018-02-19

Ultrafast spectroscopy with attosecond resolution has enabled the real time observation of ultrafast electron dynamics in atoms, molecules and solids. These experiments employ attosecond pulses or pulse trains and explore dynamical processes in a pump-probe scheme that is selectively sensitive to electronic state of matter via photoelectron or XUV absorption spectroscopy or that includes changes of the ionic state detected via photo-ion mass spectrometry. Here, we demonstrate how the implementation of combined photo-ion and absorption spectroscopy with attosecond resolution enables tracking the complex multidimensional excitation and decay cascade of an Auger auto-ionization process of a few femtoseconds in highly excited krypton. In tandem with theory, our study reveals the role of intermediate electronic states in the formation of multiply charged ions. Amplitude tuning of a dressing laser field addresses different groups of decay channels and allows exerting temporal and quantitative control over the ionization dynamics in rare gas atoms.

High-resolution x-ray imaging for microbiology at the Advanced Photon Source

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lai, B.; Kemner, K. M.; Maser, J.

1999-11-02

Exciting new applications of high-resolution x-ray imaging have emerged recently due to major advances in high-brilliance synchrotrons sources and high-performance zone plate optics. Imaging with submicron resolution is now routine with hard x-rays: the authors have demonstrated 150 run in the 6--10 keV range with x-ray microscopes at the Advanced Photon Source (APS), a third-generation synchrotrons radiation facility. This has fueled interest in using x-ray imaging in applications ranging from the biomedical, environmental, and materials science fields to the microelectronics industry. One important application they have pursued at the APS is a study of the microbiology of bacteria and theirmore » associated extracellular material (biofilms) using fluorescence microanalysis. No microscopy techniques were previously available with sufficient resolution to study live bacteria ({approx}1 {micro}m x 4 {micro}m in size) and biofilms in their natural hydrated state with better than part-per-million elemental sensitivity and the capability of determining g chemical speciation. In vivo x-ray imaging minimizes artifacts due to sample fixation, drying, and staining. This provides key insights into the transport of metal contaminants by bacteria in the environment and potential new designs for remediation and sequestration strategies.« less

Analysis of very-high-resolution Galileo images of Europa: Implications for small-scale structure and surface evolution

NASA Astrophysics Data System (ADS)

Leonard, E. J.; Pappalardo, R. T.; Yin, A.; Prockter, L. M.; Patthoff, D. A.

2014-12-01

The Galileo Solid State Imager (SSI) recorded nine very high-resolution frames (8 at 12 m/pixel and 1 at 6 m/pixel) during the E12 flyby of Europa in Dec. 1997. To understand the implications for the small-scale structure and evolution of Europa, we mosaicked these frames (observations 12ESMOTTLE01 and 02, incidence ≈18°, emission ≈77°) into their regional context (part of observation 11ESREGMAP01, 220 m/pixel, incidence ≈74°, emission ≈23°), despite their very different viewing and lighting conditions. We created a map of geological units based on morphology, structure, and albedo along with stereoscopic images where the frames overlapped. The highly diverse units range from: high albedo sub-parallel ridge and grooved terrain; to variegated-albedo hummocky terrain; to low albedo and relatively smooth terrain. We classified and analyzed the diverse units solely based on the high-resolution image mosaic, prior to comparison to the context image, to obtain an in-depth look at possible surface evolution and underlying formational processes. We infer that some of these units represent different stages and forms of resurfacing, including cryovolcanic and tectonic resurfacing. However, significant morphological variation among units in the region indicates that there are different degrees of resurfacing at work. We have created candidate morphological sequences that provide insight into the conversion of ridged plains to chaotic terrain—generally, a process of subduing formerly sharp features through tectonic modification and/or cryovolcanism. When the map of the high-resolution area is compared to the regional context, features that appear to be one unit at regional resolution are comprised of several distinct units at high resolution, and features that appear to be smooth in the context image are found to show distinct textures. Moreover, in the context image, transitions from ridged units to disrupted units appear to be gradual; however the high-resolution image reveals them to be abrupt, suggesting tectonic control of these boundaries. These discrepancies could have important implications for a future landed exploration.

Continuous probing of cold complex molecules with infrared frequency comb spectroscopy

NASA Astrophysics Data System (ADS)

Spaun, Ben; Changala, P. Bryan; Patterson, David; Bjork, Bryce J.; Heckl, Oliver H.; Doyle, John M.; Ye, Jun

2016-05-01

For more than half a century, high-resolution infrared spectroscopy has played a crucial role in probing molecular structure and dynamics. Such studies have so far been largely restricted to relatively small and simple systems, because at room temperature even molecules of modest size already occupy many millions of rotational/vibrational states, yielding highly congested spectra that are difficult to assign. Targeting more complex molecules requires methods that can record broadband infrared spectra (that is, spanning multiple vibrational bands) with both high resolution and high sensitivity. However, infrared spectroscopic techniques have hitherto been limited either by narrow bandwidth and long acquisition time, or by low sensitivity and resolution. Cavity-enhanced direct frequency comb spectroscopy (CE-DFCS) combines the inherent broad bandwidth and high resolution of an optical frequency comb with the high detection sensitivity provided by a high-finesse enhancement cavity, but it still suffers from spectral congestion. Here we show that this problem can be overcome by using buffer gas cooling to produce continuous, cold samples of molecules that are then subjected to CE-DFCS. This integration allows us to acquire a rotationally resolved direct absorption spectrum in the C-H stretching region of nitromethane, a model system that challenges our understanding of large-amplitude vibrational motion. We have also used this technique on several large organic molecules that are of fundamental spectroscopic and astrochemical relevance, including naphthalene, adamantane and hexamethylenetetramine. These findings establish the value of our approach for studying much larger and more complex molecules than have been probed so far, enabling complex molecules and their kinetics to be studied with orders-of-magnitude improvements in efficiency, spectral resolution and specificity.

Multi-beam laser altimeter

NASA Technical Reports Server (NTRS)

Bufton, Jack L.; Harding, David J.; Ramos-Izquierdo, Luis

1993-01-01

Laser altimetry provides a high-resolution, high-accuracy method for measurement of the elevation and horizontal variability of Earth-surface topography. The basis of the measurement is the timing of the round-trip propagation of short-duration pulses of laser radiation between a spacecraft and the Earth's surface. Vertical resolution of the altimetry measurement is determined primarily by laser pulsewidth, surface-induced spreading in time of the reflected pulse, and the timing precision of the altimeter electronics. With conventional gain-switched pulses from solid-state lasers and sub-nsec resolution electronics, sub-meter vertical range resolution is possible from orbital attitudes of several hundred kilometers. Horizontal resolution is a function of laser beam footprint size at the surface and the spacing between successive laser pulses. Laser divergence angle and altimeter platform height above the surface determine the laser footprint size at the surface, while laser pulse repetition-rate, laser transmitter beam configuration, and altimeter platform velocity determine the space between successive laser pulses. Multiple laser transitters in a singlaltimeter instrument provide across-track and along-track coverage that can be used to construct a range image of the Earth's surface. Other aspects of the multi-beam laser altimeter are discussed.

Single-Image Super Resolution for Multispectral Remote Sensing Data Using Convolutional Neural Networks

NASA Astrophysics Data System (ADS)

Liebel, L.; Körner, M.

2016-06-01

In optical remote sensing, spatial resolution of images is crucial for numerous applications. Space-borne systems are most likely to be affected by a lack of spatial resolution, due to their natural disadvantage of a large distance between the sensor and the sensed object. Thus, methods for single-image super resolution are desirable to exceed the limits of the sensor. Apart from assisting visual inspection of datasets, post-processing operations—e.g., segmentation or feature extraction—can benefit from detailed and distinguishable structures. In this paper, we show that recently introduced state-of-the-art approaches for single-image super resolution of conventional photographs, making use of deep learning techniques, such as convolutional neural networks (CNN), can successfully be applied to remote sensing data. With a huge amount of training data available, end-to-end learning is reasonably easy to apply and can achieve results unattainable using conventional handcrafted algorithms. We trained our CNN on a specifically designed, domain-specific dataset, in order to take into account the special characteristics of multispectral remote sensing data. This dataset consists of publicly available SENTINEL-2 images featuring 13 spectral bands, a ground resolution of up to 10m, and a high radiometric resolution and thus satisfying our requirements in terms of quality and quantity. In experiments, we obtained results superior compared to competing approaches trained on generic image sets, which failed to reasonably scale satellite images with a high radiometric resolution, as well as conventional interpolation methods.

Leveraging North Carolina's QL2 Lidar to Quantify Sensitivity of National Water Model Derived Flood Inundation Extent to DEM Resolution

NASA Astrophysics Data System (ADS)

Lovette, J. P.; Lenhardt, W. C.; Blanton, B.; Duncan, J. M.; Stillwell, L.

2017-12-01

The National Water Model (NWM) has provided a novel framework for near real time flood inundation mapping across CONUS at a 10m resolution. In many regions, this spatial scale is quickly being surpassed through the collection of high resolution lidar (1 - 3m). As one of the leading states in data collection for flood inundation mapping, North Carolina is currently improving their previously available 20 ft statewide elevation product to a Quality Level 2 (QL2) product with a nominal point spacing of 0.7 meters. This QL2 elevation product increases the ground points by roughly ten times over the previous statewide lidar product, and by over 250 times when compared to the 10m NED elevation grid. When combining these new lidar data with the discharge estimates from the NWM, we can further improve statewide flood inundation maps and predictions of at-risk areas. In the context of flood risk management, these improved predictions with higher resolution elevation models consistently represent an improvement on coarser products. Additionally, the QL2 lidar also includes coarse land cover classification data for each point return, opening the possibility for expanding analysis beyond the use of only digital elevation models (e.g. improving estimates of surface roughness, identifying anthropogenic features in floodplains, characterizing riparian zones, etc.). Using the NWM Height Above Nearest Drainage approach, we compare flood inundation extents derived from multiple lidar-derived grid resolutions to assess the tradeoff between precision and computational load in North Carolina's coastal river basins. The elevation data distributed through the state's new lidar collection program provide spatial resolutions ranging from 5-50 feet, with most inland areas also including a 3 ft product. Data storage increases by almost two orders of magnitude across this range, as does processing load. In order to further assess the validity of the higher resolution elevation products on flood inundation, we examine the NWM outputs from Hurricane Matthew, which devastated southeastern North Carolina in October 2016. When compared with numerous surveyed high water marks across the coastal plain, this assessment provides insight on the impacts of grid resolution on flood inundation extent.

Fabrication of perforated isoporous membranes via a transfer-free strategy: enabling high-resolution separation of cells.

PubMed

Ou, Yang; Lv, Chang-Jiang; Yu, Wei; Mao, Zheng-Wei; Wan, Ling-Shu; Xu, Zhi-Kang

2014-12-24

Thin perforated membranes with ordered pores are ideal barriers for high-resolution and high-efficiency selective transport and separation of biological species. However, for self-assembled thin membranes with a thickness less than several micrometers, an additional step of transferring the membranes onto porous supports is generally required. In this article, we present a facile transfer-free strategy for fabrication of robust perforated composite membranes via the breath figure process, and for the first time, demonstrate the application of the membranes in high-resolution cell separation of yeasts and lactobacilli without external pressure, achieving almost 100% rejection of yeasts and more than 70% recovery of lactobacilli with excellent viability. The avoidance of the transfer step simplifies the fabrication procedure of composite membranes and greatly improves the membrane homogeneity. Moreover, the introduction of an elastic triblock copolymer increases the interfacial strength between the membrane and the support, and allows the preservation of composite membranes in a dry state. Such perforated ordered membranes can also be applied in other size-based separation systems, enabling new opportunities in bioseparation and biosensors.

Digital micromirror device-based laser-illumination Fourier ptychographic microscopy

PubMed Central

Kuang, Cuifang; Ma, Ye; Zhou, Renjie; Lee, Justin; Barbastathis, George; Dasari, Ramachandra R.; Yaqoob, Zahid; So, Peter T. C.

2015-01-01

We report a novel approach to Fourier ptychographic microscopy (FPM) by using a digital micromirror device (DMD) and a coherent laser source (532 nm) for generating spatially modulated sample illumination. Previously demonstrated FPM systems are all based on partially-coherent illumination, which offers limited throughput due to insufficient brightness. Our FPM employs a high power coherent laser source to enable shot-noise limited high-speed imaging. For the first time, a digital micromirror device (DMD), imaged onto the back focal plane of the illumination objective, is used to generate spatially modulated sample illumination field for ptychography. By coding the on/off states of the micromirrors, the illumination plane wave angle can be varied at speeds more than 4 kHz. A set of intensity images, resulting from different oblique illuminations, are used to numerically reconstruct one high-resolution image without obvious laser speckle. Experiments were conducted using a USAF resolution target and a fiber sample, demonstrating high-resolution imaging capability of our system. We envision that our approach, if combined with a coded-aperture compressive-sensing algorithm, will further improve the imaging speed in DMD-based FPM systems. PMID:26480361

Digital micromirror device-based laser-illumination Fourier ptychographic microscopy.

PubMed

Kuang, Cuifang; Ma, Ye; Zhou, Renjie; Lee, Justin; Barbastathis, George; Dasari, Ramachandra R; Yaqoob, Zahid; So, Peter T C

2015-10-19

We report a novel approach to Fourier ptychographic microscopy (FPM) by using a digital micromirror device (DMD) and a coherent laser source (532 nm) for generating spatially modulated sample illumination. Previously demonstrated FPM systems are all based on partially-coherent illumination, which offers limited throughput due to insufficient brightness. Our FPM employs a high power coherent laser source to enable shot-noise limited high-speed imaging. For the first time, a digital micromirror device (DMD), imaged onto the back focal plane of the illumination objective, is used to generate spatially modulated sample illumination field for ptychography. By coding the on/off states of the micromirrors, the illumination plane wave angle can be varied at speeds more than 4 kHz. A set of intensity images, resulting from different oblique illuminations, are used to numerically reconstruct one high-resolution image without obvious laser speckle. Experiments were conducted using a USAF resolution target and a fiber sample, demonstrating high-resolution imaging capability of our system. We envision that our approach, if combined with a coded-aperture compressive-sensing algorithm, will further improve the imaging speed in DMD-based FPM systems.

High-resolution Single Particle Analysis from Electron Cryo-microscopy Images Using SPHIRE

PubMed Central

Moriya, Toshio; Saur, Michael; Stabrin, Markus; Merino, Felipe; Voicu, Horatiu; Huang, Zhong; Penczek, Pawel A.; Raunser, Stefan; Gatsogiannis, Christos

2017-01-01

SPHIRE (SPARX for High-Resolution Electron Microscopy) is a novel open-source, user-friendly software suite for the semi-automated processing of single particle electron cryo-microscopy (cryo-EM) data. The protocol presented here describes in detail how to obtain a near-atomic resolution structure starting from cryo-EM micrograph movies by guiding users through all steps of the single particle structure determination pipeline. These steps are controlled from the new SPHIRE graphical user interface and require minimum user intervention. Using this protocol, a 3.5 Å structure of TcdA1, a Tc toxin complex from Photorhabdus luminescens, was derived from only 9500 single particles. This streamlined approach will help novice users without extensive processing experience and a priori structural information, to obtain noise-free and unbiased atomic models of their purified macromolecular complexes in their native state. PMID:28570515

Taking the Measure of Massive Stars and their Environments with the CHARA Array Long-baseline Interferometer

NASA Astrophysics Data System (ADS)

Gies, Douglas R.

2017-11-01

Most massive stars are so distant that their angular diameters are too small for direct resolution. However, the observational situation is now much more favorable, thanks to new opportunities available with optical/IR long-baseline interferometry. The Georgia State University Center for High Angular Resolution Astronomy Array at Mount Wilson Observatory is a six-telescope instrument with a maximum baseline of 330 meters, which is capable of resolving stellar disks with diameters as small as 0.2 milliarcsec. The distant stars are no longer out of range, and many kinds of investigations are possible. Here we summarize a number of studies involving angular diameter measurements and effective temperature estimates for OB stars, binary and multiple stars (including the σ Orionis system), and outflows in Luminous Blue Variables. An enlarged visitors program will begin in 2017 that will open many opportunities for new programs in high angular resolution astronomy.

Modeling photovoltaic diffusion: an analysis of geospatial datasets

NASA Astrophysics Data System (ADS)

Davidson, Carolyn; Drury, Easan; Lopez, Anthony; Elmore, Ryan; Margolis, Robert

2014-07-01

This study combines address-level residential photovoltaic (PV) adoption trends in California with several types of geospatial information—population demographics, housing characteristics, foreclosure rates, solar irradiance, vehicle ownership preferences, and others—to identify which subsets of geospatial information are the best predictors of historical PV adoption. Number of rooms, heating source and house age were key variables that had not been previously explored in the literature, but are consistent with the expected profile of a PV adopter. The strong relationship provided by foreclosure indicators and mortgage status have less of an intuitive connection to PV adoption, but may be highly correlated with characteristics inherent in PV adopters. Next, we explore how these predictive factors and model performance varies between different Investor Owned Utility (IOU) regions in California, and at different spatial scales. Results suggest that models trained with small subsets of geospatial information (five to eight variables) may provide similar explanatory power as models using hundreds of geospatial variables. Further, the predictive performance of models generally decreases at higher resolution, i.e., below ZIP code level since several geospatial variables with coarse native resolution become less useful for representing high resolution variations in PV adoption trends. However, for California we find that model performance improves if parameters are trained at the regional IOU level rather than the state-wide level. We also find that models trained within one IOU region are generally representative for other IOU regions in CA, suggesting that a model trained with data from one state may be applicable in another state.

Design principles and applications of a cooled CCD camera for electron microscopy.

PubMed

Faruqi, A R

1998-01-01

Cooled CCD cameras offer a number of advantages in recording electron microscope images with CCDs rather than film which include: immediate availability of the image in a digital format suitable for further computer processing, high dynamic range, excellent linearity and a high detective quantum efficiency for recording electrons. In one important respect however, film has superior properties: the spatial resolution of CCD detectors tested so far (in terms of point spread function or modulation transfer function) are inferior to film and a great deal of our effort has been spent in designing detectors with improved spatial resolution. Various instrumental contributions to spatial resolution have been analysed and in this paper we discuss the contribution of the phosphor-fibre optics system in this measurement. We have evaluated the performance of a number of detector components and parameters, e.g. different phosphors (and a scintillator), optical coupling with lens or fibre optics with various demagnification factors, to improve the detector performance. The camera described in this paper, which is based on this analysis, uses a tapered fibre optics coupling between the phosphor and the CCD and is installed on a Philips CM12 electron microscope equipped to perform cryo-microscopy. The main use of the camera so far has been in recording electron diffraction patterns from two dimensional crystals of bacteriorhodopsin--from wild type and from different trapped states during the photocycle. As one example of the type of data obtained with the CCD camera a two dimensional Fourier projection map from the trapped O-state is also included. With faster computers, it will soon be possible to undertake this type of work on an on-line basis. Also, with improvements in detector size and resolution, CCD detectors, already ideal for diffraction, will be able to compete with film in the recording of high resolution images.

One-way coupling of an atmospheric and a hydrologic model in Colorado

USGS Publications Warehouse

Hay, L.E.; Clark, M.P.; Pagowski, M.; Leavesley, G.H.; Gutowski, W.J.

2006-01-01

This paper examines the accuracy of high-resolution nested mesoscale model simulations of surface climate. The nesting capabilities of the atmospheric fifth-generation Pennsylvania State University (PSU)-National Center for Atmospheric Research (NCAR) Mesoscale Model (MM5) were used to create high-resolution, 5-yr climate simulations (from 1 October 1994 through 30 September 1999), starting with a coarse nest of 20 km for the western United States. During this 5-yr period, two finer-resolution nests (5 and 1.7 km) were run over the Yampa River basin in northwestern Colorado. Raw and bias-corrected daily precipitation and maximum and minimum temperature time series from the three MM5 nests were used as input to the U.S. Geological Survey's distributed hydrologic model [the Precipitation Runoff Modeling System (PRMS)] and were compared with PRMS results using measured climate station data. The distributed capabilities of PRMS were provided by partitioning the Yampa River basin into hydrologic response units (HRUs). In addition to the classic polygon method of HRU definition, HRUs for PRMS were defined based on the three MM5 nests. This resulted in 16 datasets being tested using PRMS. The input datasets were derived using measured station data and raw and bias-corrected MM5 20-, 5-, and 1.7-km output distributed to 1) polygon HRUs and 2) 20-, 5-, and 1.7-km-gridded HRUs, respectively. Each dataset was calibrated independently, using a multiobjective, stepwise automated procedure. Final results showed a general increase in the accuracy of simulated runoff with an increase in HRU resolution. In all steps of the calibration procedure, the station-based simulations of runoff showed higher accuracy than the MM5-based simulations, although the accuracy of MM5 simulations was close to station data for the high-resolution nests. Further work is warranted in identifying the causes of the biases in MM5 local climate simulations and developing methods to remove them. ?? 2006 American Meteorological Society.

Potential sites for tidal power in New Jersey.

DOT National Transportation Integrated Search

2014-04-01

High-resolution simulation is made to model tidal energy along the coastlines of New Jersey (NJ) and its neighbor states with an : unprecedentedly fine grid. On the basis of the simulation, a thorough search is made for sites for tidal power generati...

Assessment and recommendations for using high-resolution weather information to improve winter maintenance operations.

DOT National Transportation Integrated Search

2013-11-01

A variety of methods for obtaining detailed analyses regarding the timing and duration of winter weather across the state of Indiana for : multiple seasons were compared and evaluated during this project. Meteorological information from sources such ...

Mobile Air Quality Monitoring for Local High-Resolution Characterization of Vehicle-Sourced Criteria Pollutant

DOT National Transportation Integrated Search

2017-06-19

Transportation-related emissions are a major source of air pollution in many urban areas. Human exposure to this pollution is related to their proximity to major roadways, yet federal and state Environmental Protection Agencies (EPAs) conduct regulat...

Observation of topological superconductivity on the surface of an iron-based superconductor

NASA Astrophysics Data System (ADS)

Zhang, Peng; Yaji, Koichiro; Hashimoto, Takahiro; Ota, Yuichi; Kondo, Takeshi; Okazaki, Kozo; Wang, Zhijun; Wen, Jinsheng; Gu, G. D.; Ding, Hong; Shin, Shik

2018-04-01

Topological superconductors are predicted to host exotic Majorana states that obey non-Abelian statistics and can be used to implement a topological quantum computer. Most of the proposed topological superconductors are realized in difficult-to-fabricate heterostructures at very low temperatures. By using high-resolution spin-resolved and angle-resolved photoelectron spectroscopy, we find that the iron-based superconductor FeTe1–xSex (x = 0.45; superconducting transition temperature Tc = 14.5 kelvin) hosts Dirac-cone–type spin-helical surface states at the Fermi level; the surface states exhibit an s-wave superconducting gap below Tc. Our study shows that the surface states of FeTe0.55Se0.45 are topologically superconducting, providing a simple and possibly high-temperature platform for realizing Majorana states.

Phase contrast scanning transmission electron microscopy imaging of light and heavy atoms at the limit of contrast and resolution.

PubMed

Yücelen, Emrah; Lazić, Ivan; Bosch, Eric G T

2018-02-08

Using state of the art scanning transmission electron microscopy (STEM) it is nowadays possible to directly image single atomic columns at sub-Å resolution. In standard (high angle) annular dark field STEM ((HA)ADF-STEM), however, light elements are usually invisible when imaged together with heavier elements in one image. Here we demonstrate the capability of the recently introduced Integrated Differential Phase Contrast STEM (iDPC-STEM) technique to image both light and heavy atoms in a thin sample at sub-Å resolution. We use the technique to resolve both the Gallium and Nitrogen dumbbells in a GaN crystal in [[Formula: see text

Observation of the Λ⁷He Hypernucleus by the (e, e'K⁺) Reaction

DOE PAGES

Nakamura, S. N.; Matsumura, A.; Okayasu, Y.; ...

2013-01-02

An experiment with a newly developed high-resolution kaon spectrometer and a scattered electron spectrometer with a novel configuration was performed in Hall C at Jefferson Lab. The ground state of a neutron-rich hypernucleus, He Λ⁷, was observed for the first time with the (e, e'K⁺) reaction with an energy resolution of ~0.6 MeV. This resolution is the best reported to date for hypernuclear reaction spectroscopy. The He Λ⁷ binding energy supplies the last missing information of the A=7, T=1 hypernuclear isotriplet, providing a new input for the charge symmetry breaking effect of the ΛN potential.

Tracking fronts in solutions of the shallow-water equations

NASA Astrophysics Data System (ADS)

Bennett, Andrew F.; Cummins, Patrick F.

1988-02-01

A front-tracking algorithm of Chern et al. (1986) is tested on the shallow-water equations, using the Parrett and Cullen (1984) and Williams and Hori (1970) initial state, consisting of smooth finite amplitude waves depending on one space dimension alone. At high resolution the solution is almost indistinguishable from that obtained with the Glimm algorithm. The latter is known to converge to the true frontal solution, but is 20 times less efficient at the same resolution. The solutions obtained using the front-tracking algorithm at 8 times coarser resolution are quite acceptable, indicating a very substantial gain in efficiency, which encourages application in realistic ocean models possessing two or three space dimensions.

High Performance Computing-based Assessment of the Impacts of Climate Change on the Santa Cruz and San Pedro River Basin at Very High Resolution

NASA Astrophysics Data System (ADS)

Robles-Morua, A.; Vivoni, E. R.; Rivera-Fernandez, E. R.; Dominguez, F.; Meixner, T.

2012-12-01

Assessing the impact of climate change on large river basins in the southwestern United States is important given the natural water scarcity in the region. The bimodal distribution of annual precipitation also presents a challenge as differential climate impacts during the winter and summer seasons are not currently well understood. In this work, we focus on the hydrological consequences of climate change in the Santa Cruz and San Pedro river basins along the Arizona-Sonora border at high spatiotemporal resolutions (~100 m and ~1 hour). These river systems support rich ecological communities along riparian corridors that provide habitat to migratory birds and support recreational and economic activities. Determining the climate impacts on riparian communities involves assessing how river flows and groundwater recharge will change with altered temperature and precipitation regimes. In this study, we use a distributed hydrologic model, known as the TIN-based Real-time Integrated Basin Simulator (tRIBS), to generate simulated hydrological fields under historical (1991-2000) and climate change (2031-2040) scenarios obtained from an application of the Weather Research and Forecast (WRF) model. Using the distributed model, we transform the meteorological scenarios from WRF at 10-km, hourly resolution into predictions of the annual water budget, seasonal land surface fluxes and individual hydrographs of flood and recharge events. For this contribution, we selected two full years in the historical period and in the future scenario that represent wet and dry conditions for each decade. Given the size of the two basins, we rely on a high performance computing platform and a parallel domain discretization using sub-basin partitioning with higher resolutions maintained at experimental catchments in each river basin. Model simulations utilize best-available data across the Arizona-Sonora border on topography, land cover and soils obtained from analysis of remotely-sensed imagery and government databases. For the historical period, we build confidence in the model simulations through comparisons with streamflow estimates in the region. We also evaluate the WRF forcing outcomes with respect to meteorological inputs from ground rain gauges and the North American Land Data Assimilation System (NLDAS). We then analyze the high-resolution spatiotemporal predictions of soil moisture, evapotranspiration, runoff generation and recharge under past conditions and for the climate change scenario. A comparison with the historical period will yield a first-of-its-kind assessment at very high spatiotemporal resolution on the impacts of climate change on the hydrologic response of two large semiarid river basins of the southwestern United States.

Liquid- and solid-state high-resolution NMR methods for the investigation of aging processes of silicone breast implants.

PubMed

Birkefeld, Anja Britta; Bertermann, Rüdiger; Eckert, Hellmut; Pfleiderer, Bettina

2003-01-01

To investigate aging processes of silicone gel breast implants, which may include migration of free unreacted material from the gel and rubber to local (e.g. connective tissue capsule) or distant sites in the body, chemical alteration of the polymer and infiltration of body compounds, various approaches of multinuclear nuclear magnetic resonance (NMR) experiments (29Si, 13C, 1H) were evaluated. While 29Si, 13C, and 1H solid-state magic angle spinning (MAS) NMR techniques performed on virgin and explanted envelopes of silicone prostheses provided only limited information, high-resolution liquid-state NMR techniques of CDCl(3) extracts were highly sensitive analytical tools for the detection of aging related changes in the materials. Using 2D 1H, 1H correlation spectroscopy (COSY) and 29Si, 1H heteronuclear multiple bond coherence (HMBC) experiments with gradient selection, it was possible to detect lipids (mainly phospholipids) as well as silicone oligomer species in explanted envelopes and gels. Silicone oligomers were also found in connective tissue capsules, indicating that cyclic polysiloxanes can migrate from intact implants to adjacent and distant sites. Furthermore, lipids can permeate the implant and modify its chemical composition. Copyright 2002 Elsevier Science Ltd.

Simple platform for chronic imaging of hippocampal activity during spontaneous behaviour in an awake mouse

PubMed Central

Villette, Vincent; Levesque, Mathieu; Miled, Amine; Gosselin, Benoit; Topolnik, Lisa

2017-01-01

Chronic electrophysiological recordings of neuronal activity combined with two-photon Ca2+ imaging give access to high resolution and cellular specificity. In addition, awake drug-free experimentation is required for investigating the physiological mechanisms that operate in the brain. Here, we developed a simple head fixation platform, which allows simultaneous chronic imaging and electrophysiological recordings to be obtained from the hippocampus of awake mice. We performed quantitative analyses of spontaneous animal behaviour, the associated network states and the cellular activities in the dorsal hippocampus as well as estimated the brain stability limits to image dendritic processes and individual axonal boutons. Ca2+ imaging recordings revealed a relatively stereotyped hippocampal activity despite a high inter-animal and inter-day variability in the mouse behavior. In addition to quiet state and locomotion behavioural patterns, the platform allowed the reliable detection of walking steps and fine speed variations. The brain motion during locomotion was limited to ~1.8 μm, thus allowing for imaging of small sub-cellular structures to be performed in parallel with recordings of network and behavioural states. This simple device extends the drug-free experimentation in vivo, enabling high-stability optophysiological experiments with single-bouton resolution in the mouse awake brain. PMID:28240275

Space-based observations of nitrogen dioxide: Trends in anthropogenic emissions

NASA Astrophysics Data System (ADS)

Russell, Ashley Ray

Space-based instruments provide routine global observations, offering a unique perspective on the spatial and temporal variation of atmospheric constituents. In this dissertation, trends in regional-scale anthropogenic nitrogen oxide emissions (NO + NO2 ≡ NOx) are investigated using high resolution observations from the Ozone Monitoring Instrument (OMI). By comparing trends in OMI observations with those from ground-based measurements and an emissions inventory, I show that satellite observations are well-suited for capturing changes in emissions over time. The high spatial and temporal resolutions of the observations provide a uniquely complete view of regional-scale changes in the spatial patterns of NO 2. I show that NOx concentrations have decreased significantly in urban regions of the United States between 2005 and 2011, with an average reduction of 32 ± 7%. By examining day-of-week and interannual trends, I show that these reductions can largely be attributed to improved emission control technology in the mobile source fleet; however, I also show that the economic downturn of the late 2000's has impacted emissions. Additionally, I describe the development of a high-resolution retrieval of NO2 from OMI observations known as the Berkeley High Resolution (BEHR) retrieval. The BEHR product uses higher spatial and temporal resolution terrain and profile parameters than the operational retrievals and is shown to provide a more quantitative measure of tropospheric NO2 column density. These results have important implications for future retrievals of NO2 from space-based observations.

Integration of High-resolution Data for Temporal Bone Surgical Simulations

PubMed Central

Wiet, Gregory J.; Stredney, Don; Powell, Kimerly; Hittle, Brad; Kerwin, Thomas

2016-01-01

Purpose To report on the state of the art in obtaining high-resolution 3D data of the microanatomy of the temporal bone and to process that data for integration into a surgical simulator. Specifically, we report on our experience in this area and discuss the issues involved to further the field. Data Sources Current temporal bone image acquisition and image processing established in the literature as well as in house methodological development. Review Methods We reviewed the current English literature for the techniques used in computer-based temporal bone simulation systems to obtain and process anatomical data for use within the simulation. Search terms included “temporal bone simulation, surgical simulation, temporal bone.” Articles were chosen and reviewed that directly addressed data acquisition and processing/segmentation and enhancement with emphasis given to computer based systems. We present the results from this review in relationship to our approach. Conclusions High-resolution CT imaging (≤100μm voxel resolution), along with unique image processing and rendering algorithms, and structure specific enhancement are needed for high-level training and assessment using temporal bone surgical simulators. Higher resolution clinical scanning and automated processes that run in efficient time frames are needed before these systems can routinely support pre-surgical planning. Additionally, protocols such as that provided in this manuscript need to be disseminated to increase the number and variety of virtual temporal bones available for training and performance assessment. PMID:26762105

Fabrication High Resolution Metrology Target By Step And Repeat Method

NASA Astrophysics Data System (ADS)

Dusa, Mircea

1983-10-01

Based on the photolithography process generally used to generate high resolution masks for semiconductor I.C.S, we found a very useful industrial application of laser technology.First, we have generated high resolution metrology targets which are used in industrial measurement laser interferometers as difra.ction gratings. Secondi we have generated these targets using step and repeat machine, with He-Ne laser interferometer controlled state, as a pattern generator, due to suitable computer programming.Actually, high resolution metrology target, means two chromium plates, one of which is called the" rule" the other one the "vernier". In Fig.1 we have the configuration of the rule and the vernier. The rule has a succesion of 3 μM lines generated as a difraction grating on a 4 x 4 inch chromium blank. The vernier has several exposed fields( areas) having 3 - 15 μm lines, fields placed on very precise position on the chromium blank surface. High degree of uniformity, tight CD tolerances, low defect density required by the targets, creates specialised problems during processing. Details of the processing, together with experimental results will be presented. Before we start to enter into process details, we have to point out that the dimensional requirements of the reticle target, are quite similar or perhaps more strict than LSI master casks. These requirements presented in Fig.2.

Boundaries of mass resolution in native mass spectrometry.

PubMed

Lössl, Philip; Snijder, Joost; Heck, Albert J R

2014-06-01

Over the last two decades, native mass spectrometry (MS) has emerged as a valuable tool to study intact proteins and noncovalent protein complexes. Studied experimental systems range from small-molecule (drug)-protein interactions, to nanomachineries such as the proteasome and ribosome, to even virus assembly. In native MS, ions attain high m/z values, requiring special mass analyzers for their detection. Depending on the particular mass analyzer used, instrumental mass resolution does often decrease at higher m/z but can still be above a couple of thousand at m/z 5000. However, the mass resolving power obtained on charge states of protein complexes in this m/z region is experimentally found to remain well below the inherent instrument resolution of the mass analyzers employed. Here, we inquire into reasons for this discrepancy and ask how native MS would benefit from higher instrumental mass resolution. To answer this question, we discuss advantages and shortcomings of mass analyzers used to study intact biomolecules and biomolecular complexes in their native state, and we review which other factors determine mass resolving power in native MS analyses. Recent examples from the literature are given to illustrate the current status and limitations.

A Super-Resolution Algorithm for Enhancement of FLASH LIDAR Data: Flight Test Results

NASA Technical Reports Server (NTRS)

Bulyshev, Alexander; Amzajerdian, Farzin; Roback, Eric; Reisse Robert

2014-01-01

This paper describes the results of a 3D super-resolution algorithm applied to the range data obtained from a recent Flash Lidar helicopter flight test. The flight test was conducted by the NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) project over a simulated lunar terrain facility at NASA Kennedy Space Center. ALHAT is developing the technology for safe autonomous landing on the surface of celestial bodies: Moon, Mars, asteroids. One of the test objectives was to verify the ability of 3D super-resolution technique to generate high resolution digital elevation models (DEMs) and to determine time resolved relative positions and orientations of the vehicle. 3D super-resolution algorithm was developed earlier and tested in computational modeling, and laboratory experiments, and in a few dynamic experiments using a moving truck. Prior to the helicopter flight test campaign, a 100mX100m hazard field was constructed having most of the relevant extraterrestrial hazard: slopes, rocks, and craters with different sizes. Data were collected during the flight and then processed by the super-resolution code. The detailed DEM of the hazard field was constructed using independent measurement to be used for comparison. ALHAT navigation system data were used to verify abilities of super-resolution method to provide accurate relative navigation information. Namely, the 6 degree of freedom state vector of the instrument as a function of time was restored from super-resolution data. The results of comparisons show that the super-resolution method can construct high quality DEMs and allows for identifying hazards like rocks and craters within the accordance of ALHAT requirements.

A super-resolution algorithm for enhancement of flash lidar data: flight test results

NASA Astrophysics Data System (ADS)

Bulyshev, Alexander; Amzajerdian, Farzin; Roback, Eric; Reisse, Robert

2013-03-01

This paper describes the results of a 3D super-resolution algorithm applied to the range data obtained from a recent Flash Lidar helicopter flight test. The flight test was conducted by the NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) project over a simulated lunar terrain facility at NASA Kennedy Space Center. ALHAT is developing the technology for safe autonomous landing on the surface of celestial bodies: Moon, Mars, asteroids. One of the test objectives was to verify the ability of 3D super-resolution technique to generate high resolution digital elevation models (DEMs) and to determine time resolved relative positions and orientations of the vehicle. 3D super-resolution algorithm was developed earlier and tested in computational modeling, and laboratory experiments, and in a few dynamic experiments using a moving truck. Prior to the helicopter flight test campaign, a 100mX100m hazard field was constructed having most of the relevant extraterrestrial hazard: slopes, rocks, and craters with different sizes. Data were collected during the flight and then processed by the super-resolution code. The detailed DEM of the hazard field was constructed using independent measurement to be used for comparison. ALHAT navigation system data were used to verify abilities of super-resolution method to provide accurate relative navigation information. Namely, the 6 degree of freedom state vector of the instrument as a function of time was restored from super-resolution data. The results of comparisons show that the super-resolution method can construct high quality DEMs and allows for identifying hazards like rocks and craters within the accordance of ALHAT requirements.

A Modeling and Verification Study of Summer Precipitation Systems Using NASA Surface Initialization Datasets

NASA Technical Reports Server (NTRS)

Jonathan L. Case; Kumar, Sujay V.; Srikishen, Jayanthi; Jedlovec, Gary J.

2010-01-01

One of the most challenging weather forecast problems in the southeastern U.S. is daily summertime pulse-type convection. During the summer, atmospheric flow and forcing are generally weak in this region; thus, convection typically initiates in response to local forcing along sea/lake breezes, and other discontinuities often related to horizontal gradients in surface heating rates. Numerical simulations of pulse convection usually have low skill, even in local predictions at high resolution, due to the inherent chaotic nature of these precipitation systems. Forecast errors can arise from assumptions within parameterization schemes, model resolution limitations, and uncertainties in both the initial state of the atmosphere and land surface variables such as soil moisture and temperature. For this study, it is hypothesized that high-resolution, consistent representations of surface properties such as soil moisture, soil temperature, and sea surface temperature (SST) are necessary to better simulate the interactions between the surface and atmosphere, and ultimately improve predictions of summertime pulse convection. This paper describes a sensitivity experiment using the Weather Research and Forecasting (WRF) model. Interpolated land and ocean surface fields from a large-scale model are replaced with high-resolution datasets provided by unique NASA assets in an experimental simulation: the Land Information System (LIS) and Moderate Resolution Imaging Spectroradiometer (MODIS) SSTs. The LIS is run in an offline mode for several years at the same grid resolution as the WRF model to provide compatible land surface initial conditions in an equilibrium state. The MODIS SSTs provide detailed analyses of SSTs over the oceans and large lakes compared to current operational products. The WRF model runs initialized with the LIS+MODIS datasets result in a reduction in the overprediction of rainfall areas; however, the skill is almost equally as low in both experiments using traditional verification methodologies. Output from object-based verification within NCAR s Meteorological Evaluation Tools reveals that the WRF runs initialized with LIS+MODIS data consistently generated precipitation objects that better matched observed precipitation objects, especially at higher precipitation intensities. The LIS+MODIS runs produced on average a 4% increase in matched precipitation areas and a simultaneous 4% decrease in unmatched areas during three months of daily simulations.

Distinct prediction errors in mesostriatal circuits of the human brain mediate learning about the values of both states and actions: evidence from high-resolution fMRI.

PubMed

Colas, Jaron T; Pauli, Wolfgang M; Larsen, Tobias; Tyszka, J Michael; O'Doherty, John P

2017-10-01

Prediction-error signals consistent with formal models of "reinforcement learning" (RL) have repeatedly been found within dopaminergic nuclei of the midbrain and dopaminoceptive areas of the striatum. However, the precise form of the RL algorithms implemented in the human brain is not yet well determined. Here, we created a novel paradigm optimized to dissociate the subtypes of reward-prediction errors that function as the key computational signatures of two distinct classes of RL models-namely, "actor/critic" models and action-value-learning models (e.g., the Q-learning model). The state-value-prediction error (SVPE), which is independent of actions, is a hallmark of the actor/critic architecture, whereas the action-value-prediction error (AVPE) is the distinguishing feature of action-value-learning algorithms. To test for the presence of these prediction-error signals in the brain, we scanned human participants with a high-resolution functional magnetic-resonance imaging (fMRI) protocol optimized to enable measurement of neural activity in the dopaminergic midbrain as well as the striatal areas to which it projects. In keeping with the actor/critic model, the SVPE signal was detected in the substantia nigra. The SVPE was also clearly present in both the ventral striatum and the dorsal striatum. However, alongside these purely state-value-based computations we also found evidence for AVPE signals throughout the striatum. These high-resolution fMRI findings suggest that model-free aspects of reward learning in humans can be explained algorithmically with RL in terms of an actor/critic mechanism operating in parallel with a system for more direct action-value learning.

Distinct prediction errors in mesostriatal circuits of the human brain mediate learning about the values of both states and actions: evidence from high-resolution fMRI

PubMed Central

Pauli, Wolfgang M.; Larsen, Tobias; Tyszka, J. Michael; O’Doherty, John P.

2017-01-01

Prediction-error signals consistent with formal models of “reinforcement learning” (RL) have repeatedly been found within dopaminergic nuclei of the midbrain and dopaminoceptive areas of the striatum. However, the precise form of the RL algorithms implemented in the human brain is not yet well determined. Here, we created a novel paradigm optimized to dissociate the subtypes of reward-prediction errors that function as the key computational signatures of two distinct classes of RL models—namely, “actor/critic” models and action-value-learning models (e.g., the Q-learning model). The state-value-prediction error (SVPE), which is independent of actions, is a hallmark of the actor/critic architecture, whereas the action-value-prediction error (AVPE) is the distinguishing feature of action-value-learning algorithms. To test for the presence of these prediction-error signals in the brain, we scanned human participants with a high-resolution functional magnetic-resonance imaging (fMRI) protocol optimized to enable measurement of neural activity in the dopaminergic midbrain as well as the striatal areas to which it projects. In keeping with the actor/critic model, the SVPE signal was detected in the substantia nigra. The SVPE was also clearly present in both the ventral striatum and the dorsal striatum. However, alongside these purely state-value-based computations we also found evidence for AVPE signals throughout the striatum. These high-resolution fMRI findings suggest that model-free aspects of reward learning in humans can be explained algorithmically with RL in terms of an actor/critic mechanism operating in parallel with a system for more direct action-value learning. PMID:29049406

80 and 100 Meter Wind Energy Resource Potential for the United States (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elliott, D.; Schwartz, M.; Haymes, S.

Accurate information about the wind potential in each state is required for federal and state policy initiatives that will expand the use of wind energy in the United States. The National Renewable Energy Laboratory (NREL) and AWS Truewind have collaborated to produce the first comprehensive new state-level assessment of wind resource potential since 1993. The estimates are based on high-resolution maps of predicted mean annual wind speeds for the contiguous 48 states developed by AWS Truewind. These maps, at spatial resolution of 200 meters and heights of 60 to 100 meters, were created with a mesoscale-microscale modeling technique and adjustedmore » to reduce errors through a bias-correction procedure involving data from more than 1,000 measurement masts. NREL used the capacity factor maps to estimate the wind energy potential capacity in megawatts for each state by capacity factor ranges. The purpose of this presentation is to (1) inform state and federal policy makers, regulators, developers, and other stakeholders on the availability of the new wind potential information that may influence development, (2) inform the audience of how the new information was derived, and (3) educate the audience on how the information should be interpreted in developing state and federal policy initiatives.« less

Transport systems of Ventricaria ventricosa: I/V analysis of both membranes in series as a function of [K(+)](o).

PubMed

Beilby, M J; Bisson, M A

1999-09-01

The current-voltage (I/V) profiles of Ventricaria (formerly Valonia) membranes were measured at a range of external potassium concentrations, [K(+)](o), from 0.1 to 100 mm. The conductance-voltage (G/V) characteristics were computed to facilitate better resolution of the profile change with time after exposure to different [K(+)](o). The resistance-voltage (R/V) characteristics were computed to attempt resolution of plasmalemma and tonoplast. Four basic electrophysiological stages emerged: (1) Uniform low resistance between -60 and +60 mV after the cell impalement. (2) High resistance between +50 and +150 for [K(+)](o) from 0.1 to 1.0 mm and hypotonic media. (3) High resistance between -150 and -20 mV for [K(+)](o) of 10 mm (close to natural seawater) and hypertonic media. (4) High resistance between -150 and +170 mV at [K(+)](o) of 100 mm. The changes between these states were slow, requiring minutes to hours and sometimes exhibiting spontaneous oscillations of the membrane p.d. (potential difference). Our analysis of the I/V data supports a previous hypothesis, that Ventricaria tonoplast is the more resistive membrane containing a pump, which transports K(+) into the vacuole to regulate turgor. We associate state (1) with the plasmalemma conductance being dominant and the K(+) pump at the tonoplast short-circuited probably by a K(+) channel, state (2) with the K(+) pump "off" or short-circuited at p.d.s more negative than +50 mV, state (3) with the K(+) pump "on, " and state (4) with the pump dominant, but affected by high K(+). A model for the Ventricaria membrane system is proposed.

Investigating the reactivity of pMDI with wood cell walls using high-resolution solution-state NMR spectroscopy

Treesearch

Daniel J. Yelle; John Ralph; Charles R. Frihart

2009-01-01

The objectives of this study are the following: (1) Use solution-state NMR to assign contours in HSQC spectra of the reaction products between pMDI model compounds and: (a) lignin model compounds, (b) milled-wood lignin, (c) ball-milled wood, (d) microtomed loblolly pine; (2) Determine where and to what degree urethane formation occurs with loblolly pine cell wall...

Turbulent Structure Under Short Fetch Wind Waves

DTIC Science & Technology

2015-12-01

1970) developed the LFT utilizing the concurrent measurement of sea surface elevation (η) and the near surface velocities to isolate the wave...Layers and Air-Sea Transfer program by making very high spatial resolution profile measurements of the 3-D velocity field into the crest-trough...distribution is unlimited TURBULENT STRUCTURE UNDER SHORT FETCH WIND WAVES Michael J. Papa Lieutenant Commander, United States Navy B.S., United States Naval

Short-Lived Electronically-Excited Diatomic Molecules Cooled via Supersonic Expansion from a Plasma Microjet

NASA Astrophysics Data System (ADS)

Houlahan, Thomas J., Jr.; Su, Rui; Eden, Gary

2014-06-01

Using a pulsed plasma microjet to generate short-lived, electronically-excited diatomic molecules, and subsequently ejecting them into vacuum to cool via supersonic expansion, we are able to monitor the cooling of molecules having radiative lifetimes as low as 16 ns. Specifically, we report on the rotational cooling of He_2 molecules in the d^3Σ_u^+, e^3Π_g, and f^3Σ_u^+ states, which have lifetimes of 25 ns, 67 ns, and 16 ns, respectively. The plasma microjet is driven with a 2.6 kV, 140 ns high-voltage pulse (risetime of 20 ns) which, when combined with a high-speed optical imaging system, allows the nonequilibrium rotational distribution for these molecular states to be monitored as they cool from 1200 K to below 250 K with spatial and temporal resolutions of below 10 μm and 10 ns, respectively. The spatial and temporal resolution afforded by this system also allows the observation of excitation transfer between the f^3Σ_u^+ state and the lower lying d^3Σ_u^+ and e^3Π_g states. The extension of this method to other electronically excited diatomics with excitation energies >5 eV will also be discussed.

Use of the quasi-geostrophic dynamical framework to reconstruct the 3-D ocean state in a high-resolution realistic simulation of North Atlantic.

NASA Astrophysics Data System (ADS)

Fresnay, Simon; Ponte, Aurélien

2017-04-01

The quasi-geostrophic (QG) framework has been, is and will be still for years to come a cornerstone method linking observations with estimates of the ocean circulation and state. We have used here the QG framework to reconstruct dynamical variables of the 3-D ocean in a state-of-the-art high-resolution (1/60 deg, 300 vertical levels) numerical simulation of the North Atlantic (NATL60). The work was carried out in 3 boxes of the simulation: Gulf Stream, Azores and Reykjaness Ridge. In a first part, general diagnostics describing the eddying dynamics have been performed and show that the QG scaling verifies in general, at depths distant from mixed layer and bathymetric gradients. Correlations with surface observables variables (e.g. temperature, sea level) were computed and estimates of quasi-geostrophic potential vorticity (QGPV) were reconstructed by the means of regression laws. It is shown that that reconstruction of QGPV exhibits valuable skill for a restricted scale range, mainly using sea level as the variable of regression. Additional discussion is given, based on the flow balanced with QGPV. This work is part of the DIMUP project, aiming to improve our ability to operationnaly estimate the ocean state.

Mercury exosphere. III: Energetic characterization of its sodium component

NASA Astrophysics Data System (ADS)

Leblanc, Francois; Chaufray, Jean-Yves; Doressoundiram, Alain; Berthelier, Jean-Jacques; Mangano, Valeria; López-Ariste, Arturo; Borin, Patrizia

2013-04-01

Mercury's sodium exosphere has been observed only few times with high spectral resolution from ground based observatories enabling the analysis of the emission spectra. These observations highlighted the energetic state of the sodium exospheric atoms relative to the surface temperature. More recently, the Doppler shift of the exospheric Na atoms was measured and interpreted as consistent with an exosphere moving outwards from the subsolar point (Potter, A.E., Morgan, T.H., Killen, R.E. [2009]. Icarus 204, 355-367). Using THEMIS solar telescope, we observed Mercury's sodium exosphere with very high spectral resolution at two opposite positions of its orbit. Using this very high spectral resolution and the scanning capabilities of THEMIS, we were able to reconstruct the 2D spatial distributions of the Doppler shifts and widths of the sodium atomic Na D2 and D1 lines. These observations revealed surprisingly large Doppler shift as well as spectral width consistent with previous observations. Starting from our 3D model of Mercury Na exosphere (Mercury Exosphere Global Circulation Model, Leblanc, F., Johnson, R.E. [2010]. Icarus 209, 280-300), we coupled this model with a 3D radiative transfer model described in a companion paper (Chaufray, J.Y., Leblanc, F. [2013]. Icarus, submitted for publication) which allows us to properly treat the non-maxwellian state of the simulated sodium exospheric population. Comparisons between THEMIS observations and simulations suggest that the previously observed energetic state of the Na exosphere might be essentially explained by a state of the Na exospheric atoms far from thermal equilibrium along with the Doppler shift dispersion of the Na atoms induced by the solar radiation pressure. However, the Doppler shift of the spectral lines cannot be explained by our modelling, suggesting either an exosphere spatially structured very differently than in our model or the inaccuracy of the spectral calibration when deriving the Doppler shift.

Structure of High Latitude Currents in Magnetosphere-Ionosphere Models

NASA Astrophysics Data System (ADS)

Wiltberger, M.; Rigler, E. J.; Merkin, V.; Lyon, J. G.

2017-03-01

Using three resolutions of the Lyon-Fedder-Mobarry global magnetosphere-ionosphere model (LFM) and the Weimer 2005 empirical model we examine the structure of the high latitude field-aligned current patterns. Each resolution was run for the entire Whole Heliosphere Interval which contained two high speed solar wind streams and modest interplanetary magnetic field strengths. Average states of the field-aligned current (FAC) patterns for 8 interplanetary magnetic field clock angle directions are computed using data from these runs. Generally speaking the patterns obtained agree well with results obtained from the Weimer 2005 computing using the solar wind and IMF conditions that correspond to each bin. As the simulation resolution increases the currents become more intense and narrow. A machine learning analysis of the FAC patterns shows that the ratio of Region 1 (R1) to Region 2 (R2) currents decreases as the simulation resolution increases. This brings the simulation results into better agreement with observational predictions and the Weimer 2005 model results. The increase in R2 current strengths also results in the cross polar cap potential (CPCP) pattern being concentrated in higher latitudes. Current-voltage relationships between the R1 and CPCP are quite similar at the higher resolution indicating the simulation is converging on a common solution. We conclude that LFM simulations are capable of reproducing the statistical features of FAC patterns.

Image super-resolution via adaptive filtering and regularization

NASA Astrophysics Data System (ADS)

Ren, Jingbo; Wu, Hao; Dong, Weisheng; Shi, Guangming

2014-11-01

Image super-resolution (SR) is widely used in the fields of civil and military, especially for the low-resolution remote sensing images limited by the sensor. Single-image SR refers to the task of restoring a high-resolution (HR) image from the low-resolution image coupled with some prior knowledge as a regularization term. One classic method regularizes image by total variation (TV) and/or wavelet or some other transform which introduce some artifacts. To compress these shortages, a new framework for single image SR is proposed by utilizing an adaptive filter before regularization. The key of our model is that the adaptive filter is used to remove the spatial relevance among pixels first and then only the high frequency (HF) part, which is sparser in TV and transform domain, is considered as the regularization term. Concretely, through transforming the original model, the SR question can be solved by two alternate iteration sub-problems. Before each iteration, the adaptive filter should be updated to estimate the initial HF. A high quality HF part and HR image can be obtained by solving the first and second sub-problem, respectively. In experimental part, a set of remote sensing images captured by Landsat satellites are tested to demonstrate the effectiveness of the proposed framework. Experimental results show the outstanding performance of the proposed method in quantitative evaluation and visual fidelity compared with the state-of-the-art methods.

Structure of high latitude currents in global magnetospheric-ionospheric models

USGS Publications Warehouse

Wiltberger, M; Rigler, E. J.; Merkin, V; Lyon, J. G

2016-01-01

Using three resolutions of the Lyon-Fedder-Mobarry global magnetosphere-ionosphere model (LFM) and the Weimer 2005 empirical model we examine the structure of the high latitude field-aligned current patterns. Each resolution was run for the entire Whole Heliosphere Interval which contained two high speed solar wind streams and modest interplanetary magnetic field strengths. Average states of the field-aligned current (FAC) patterns for 8 interplanetary magnetic field clock angle directions are computed using data from these runs. Generally speaking the patterns obtained agree well with results obtained from the Weimer 2005 computing using the solar wind and IMF conditions that correspond to each bin. As the simulation resolution increases the currents become more intense and narrow. A machine learning analysis of the FAC patterns shows that the ratio of Region 1 (R1) to Region 2 (R2) currents decreases as the simulation resolution increases. This brings the simulation results into better agreement with observational predictions and the Weimer 2005 model results. The increase in R2 current strengths also results in the cross polar cap potential (CPCP) pattern being concentrated in higher latitudes. Current-voltage relationships between the R1 and CPCP are quite similar at the higher resolution indicating the simulation is converging on a common solution. We conclude that LFM simulations are capable of reproducing the statistical features of FAC patterns.

Increasing vertical resolution of three-dimensional atmospheric water vapor retrievals using a network of scanning compact microwave radiometers

NASA Astrophysics Data System (ADS)

Sahoo, Swaroop

2011-12-01

The thermodynamic properties of the troposphere, in particular water vapor content and temperature, change in response to physical mechanisms, including frictional drag, evaporation, transpiration, heat transfer and flow modification due to terrain. The planetary boundary layer (PBL) is characterized by a high rate of change in its thermodynamic state on time scales of typically less than one hour. Large horizontal gradients in vertical wind speed and steep vertical gradients in water vapor and temperature in the PBL are associated with high-impact weather. Observation of these gradients in the PBL with high vertical resolution and accuracy is important for improvement of weather prediction. Satellite remote sensing in the visible, infrared and microwave provide qualitative and quantitative measurements of many atmospheric properties, including cloud cover, precipitation, liquid water content and precipitable water vapor in the upper troposphere. However, the ability to characterize the thermodynamic properties of the PBL is limited by the confounding factors of ground emission in microwave channels and of cloud cover in visible and IR channels. Ground-based microwave radiometers are routinely used to measure thermodynamic profiles. The vertical resolution of such profiles retrieved from radiometric brightness temperatures depends on the number and choice of frequency channels, the scanning strategy and the accuracy of brightness temperature measurements. In the standard technique, which uses brightness temperatures from vertically pointing radiometers, the vertical resolution of the retrieved water vapor profile is similar to or larger than the altitude at which retrievals are performed. This study focuses on the improvement of the vertical resolution of water vapor retrievals by including scanning measurements at a variety of elevation angles. Elevation angle scanning increases the path length of the atmospheric emission, thus improving the signal-to-noise ratio. This thesis also discusses Colorado State University's (CSU) participation in the European Space Agency (ESA)'s "Mitigation of Electromagnetic Transmission errors induced by Atmospheric WAter Vapor Effects" (METAWAVE) experiment conducted in the fall of 2008. CSU deployed a ground-based network of three Compact Microwave Radiometers for Humidity profiling (CMR-Hs) in Rome to measure atmospheric brightness temperatures. These measurements were used to retrieve high-resolution 3-D atmospheric water vapor and its variation with time. High-resolution information about water vapor can be crucial for the mitigation of wet tropospheric path delay variations that limit the quality of Interferometric Synthetic Aperture Radar satellite interferograms. Three-dimensional water vapor retrieval makes use of radiative transfer theory, algebraic tomographic reconstruction and Bayesian optimal estimation coupled with Kalman filtering. In addition, spatial interpolation (kriging) is used to retrieve water vapor density at unsampled locations. 3-D humidity retrievals from Rome data with vertical and horizontal resolution of 0.5 km are presented. The water vapor retrieved from CMR-H measurements is compared with MM5 Mesoscale Model output, as well as with measurements from the Medium Resolution Imaging Spectrometer (MERIS) aboard ESA's ENVISAT and the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard NASA's Aqua and Terra satellites.

31 CFR 560.510 - Transactions related to the resolution of disputes between the United States or United States...

Code of Federal Regulations, 2010 CFR

2010-07-01

... resolution of disputes between the United States or United States nationals and the Government of Iran. 560... between the United States or United States nationals and the Government of Iran. (a) Except as otherwise... with awards, decisions or orders of the Iran-United States Claims Tribunal in The Hague, the...

Modification of solid state CdZnTe (CZT) radiation detectors with high sensitivity or high resolution operation

DOEpatents

Washington, II, Aaron L; Duff, Martine C; Teague, Lucile C; Burger, Arnold; Groza, Michael

2014-11-11

An apparatus and process is provided to illustrate the manipulation of the internal electric field of CZT using multiple wavelength light illumination on the crystal surface at RT. The control of the internal electric field is shown through the polarization in the IR transmission image under illumination as a result of the Pockels effect.

High-Resolution Isotropic Three-Dimensional MR Imaging of the Extraforaminal Segments of the Cranial Nerves.

PubMed

Wen, Jessica; Desai, Naman S; Jeffery, Dean; Aygun, Nafi; Blitz, Ari

2018-02-01

High-resolution isotropic 3-dimensional (D) MR imaging with and without contrast is now routinely used for imaging evaluation of cranial nerve anatomy and pathologic conditions. The anatomic details of the extraforaminal segments are well-visualized on these techniques. A wide range of pathologic entities may cause enhancement or displacement of the nerve, which is now visible to an extent not available on standard 2D imaging. This article highlights the anatomy of extraforaminal segments of the cranial nerves and uses select cases to illustrate the utility and power of these sequences, with a focus on constructive interference in steady-state. Copyright © 2017 Elsevier Inc. All rights reserved.

Extracting the redox orbitals in Li battery materials with high-resolution x-ray compton scattering spectroscopy.

PubMed

Suzuki, K; Barbiellini, B; Orikasa, Y; Go, N; Sakurai, H; Kaprzyk, S; Itou, M; Yamamoto, K; Uchimoto, Y; Wang, Yung Jui; Hafiz, H; Bansil, A; Sakurai, Y

2015-02-27

We present an incisive spectroscopic technique for directly probing redox orbitals based on bulk electron momentum density measurements via high-resolution x-ray Compton scattering. Application of our method to spinel Li_{x}Mn_{2}O_{4}, a lithium ion battery cathode material, is discussed. The orbital involved in the lithium insertion and extraction process is shown to mainly be the oxygen 2p orbital. Moreover, the manganese 3d states are shown to experience spatial delocalization involving 0.16±0.05 electrons per Mn site during the battery operation. Our analysis provides a clear understanding of the fundamental redox process involved in the working of a lithium ion battery.

Performance evaluation of a two detector camera for real-time video.

PubMed

Lochocki, Benjamin; Gambín-Regadera, Adrián; Artal, Pablo

2016-12-20

Single pixel imaging can be the preferred method over traditional 2D-array imaging in spectral ranges where conventional cameras are not available. However, when it comes to real-time video imaging, single pixel imaging cannot compete with the framerates of conventional cameras, especially when high-resolution images are desired. Here we evaluate the performance of an imaging approach using two detectors simultaneously. First, we present theoretical results on how low SNR affects final image quality followed by experimentally determined results. Obtained video framerates were doubled compared to state of the art systems, resulting in a framerate from 22 Hz for a 32×32 resolution to 0.75 Hz for a 128×128 resolution image. Additionally, the two detector imaging technique enables the acquisition of images with a resolution of 256×256 in less than 3 s.

Structure-aware depth super-resolution using Gaussian mixture model

NASA Astrophysics Data System (ADS)

Kim, Sunok; Oh, Changjae; Kim, Youngjung; Sohn, Kwanghoon

2015-03-01

This paper presents a probabilistic optimization approach to enhance the resolution of a depth map. Conventionally, a high-resolution color image is considered as a cue for depth super-resolution under the assumption that the pixels with similar color likely belong to similar depth. This assumption might induce a texture transferring from the color image into the depth map and an edge blurring artifact to the depth boundaries. In order to alleviate these problems, we propose an efficient depth prior exploiting a Gaussian mixture model in which an estimated depth map is considered to a feature for computing affinity between two pixels. Furthermore, a fixed-point iteration scheme is adopted to address the non-linearity of a constraint derived from the proposed prior. The experimental results show that the proposed method outperforms state-of-the-art methods both quantitatively and qualitatively.

Large Observatory for x-ray Timing (LOFT-P): a Probe-class mission concept study

NASA Astrophysics Data System (ADS)

Wilson-Hodge, Colleen A.; Ray, Paul S.; Chakrabarty, Deepto; Feroci, Marco; Alvarez, Laura; Baysinger, Michael; Becker, Chris; Bozzo, Enrico; Brandt, Soren; Carson, Billy; Chapman, Jack; Dominguez, Alexandra; Fabisinski, Leo; Gangl, Bert; Garcia, Jay; Griffith, Christopher; Hernanz, Margarita; Hickman, Robert; Hopkins, Randall; Hui, Michelle; Ingram, Luster; Jenke, Peter; Korpela, Seppo; Maccarone, Tom; Michalska, Malgorzata; Pohl, Martin; Santangelo, Andrea; Schanne, Stephane; Schnell, Andrew; Stella, Luigi; van der Klis, Michiel; Watts, Anna; Winter, Berend; Zane, Silvia

2016-07-01

LOFT-P is a mission concept for a NASA Astrophysics Probe-Class (<$1B) X-ray timing mission, based on the LOFT M-class concept originally proposed to ESAs M3 and M4 calls. LOFT-P requires very large collecting area, high time resolution, good spectral resolution, broad-band spectral coverage (2-30 keV), highly flexible scheduling, and an ability to detect and respond promptly to time-critical targets of opportunity. It addresses science questions such as: What is the equation of state of ultra dense matter? What are the effects of strong gravity on matter spiraling into black holes? It would be optimized for sub-millisecond timing of bright Galactic X-ray sources including X-ray bursters, black hole binaries, and magnetars to study phenomena at the natural timescales of neutron star surfaces and black hole event horizons and to measure mass and spin of black holes. These measurements are synergistic to imaging and high-resolution spectroscopy instruments, addressing much smaller distance scales than are possible without very long baseline X-ray interferometry, and using complementary techniques to address the geometry and dynamics of emission regions. LOFT-P would have an effective area of >6 m2, > 10x that of the highly successful Rossi X-ray Timing Explorer (RXTE). A sky monitor (2-50 keV) acts as a trigger for pointed observations, providing high duty cycle, high time resolution monitoring of the X-ray sky with 20 times the sensitivity of the RXTE All-Sky Monitor, enabling multi-wavelength and multimessenger studies. A probe-class mission concept would employ lightweight collimator technology and large-area solid-state detectors, segmented into pixels or strips, technologies which have been recently greatly advanced during the ESA M3 Phase A study of LOFT. Given the large community interested in LOFT (>800 supporters*, the scientific productivity of this mission is expected to be very high, similar to or greater than RXTE ( 2000 refereed publications). We describe the results of a study, recently completed by the MSFC Advanced Concepts Office, that demonstrates that such a mission is feasible within a NASA probe-class mission budget.

Magnetic resonance spectroscopic imaging at superresolution: Overview and perspectives

NASA Astrophysics Data System (ADS)

Kasten, Jeffrey; Klauser, Antoine; Lazeyras, François; Van De Ville, Dimitri

2016-02-01

The notion of non-invasive, high-resolution spatial mapping of metabolite concentrations has long enticed the medical community. While magnetic resonance spectroscopic imaging (MRSI) is capable of achieving the requisite spatio-spectral localization, it has traditionally been encumbered by significant resolution constraints that have thus far undermined its clinical utility. To surpass these obstacles, research efforts have primarily focused on hardware enhancements or the development of accelerated acquisition strategies to improve the experimental sensitivity per unit time. Concomitantly, a number of innovative reconstruction techniques have emerged as alternatives to the standard inverse discrete Fourier transform (DFT). While perhaps lesser known, these latter methods strive to effect commensurate resolution gains by exploiting known properties of the underlying MRSI signal in concert with advanced image and signal processing techniques. This review article aims to aggregate and provide an overview of the past few decades of so-called "superresolution" MRSI reconstruction methodologies, and to introduce readers to current state-of-the-art approaches. A number of perspectives are then offered as to the future of high-resolution MRSI, with a particular focus on translation into clinical settings.

Harmonium: An Ultrafast Vacuum Ultraviolet Facility.

PubMed

Arrell, Christopher A; Ojeda, José; Longetti, Luca; Crepaldi, Alberto; Roth, Silvan; Gatti, Gianmarco; Clark, Andrew; van Mourik, Frank; Drabbels, Marcel; Grioni, Marco; Chergui, Majed

2017-05-31

Harmonium is a vacuum ultraviolet (VUV) photon source built within the Lausanne Centre for Ultrafast Science (LACUS). Utilising high harmonic generation, photons from 20-110 eV are available to conduct steady-state or ultrafast photoelectron and photoion spectroscopies (PES and PIS). A pulse preserving monochromator provides either high energy resolution (70 meV) or high temporal resolution (40 fs). Three endstations have been commissioned for: a) PES of liquids; b) angular resolved PES (ARPES) of solids and; c) coincidence PES and PIS of gas phase molecules or clusters. The source has several key advantages: high repetition rate (up to 15 kHz) and high photon flux (1011 photons per second at 38 eV). The capabilities of the facility complement the Swiss ultrafast and X-ray community (SwissFEL, SLS, NCCR MUST, etc.) helping to maintain Switzerland's leading role in ultrafast science in the world.

Groundwater nitrate pollution: High-resolution approach of calculating the nitrogen balance surplus for Germany

NASA Astrophysics Data System (ADS)

Klement, Laura; Bach, Martin; Breuer, Lutz; Häußermann, Uwe

2017-04-01

The latest inventory of the EU Water Framework Directive determined that 26.3% of Germany's groundwater bodies are in a poor chemical state regarding nitrate. As of late October 2016, the European Commission has filed a lawsuit against Germany for not taking appropriate measures against high nitrate levels in water bodies and thus failing to comply with the EU Nitrate Directive. Due to over-fertilization and high-density animal production, Agriculture was identified as the main source of nitrate pollution. One way to characterize the potential impact of reactive nitrogen on water bodies is the soil surface nitrogen balance where all agricultural nitrogen inputs within an area are contrasted with the output, i.e. the harvest. The surplus nitrogen (given in kg N per ha arable land and year) can potentially leach into the groundwater and thus can be used as a risk indicator. In order to develop and advocate appropriate measures to mitigate the agricultural nitrogen surplus with spatial precision, high-resolution data for the nitrogen surplus is needed. In Germany, not all nitrogen input data is available with the required spatial resolution, especially the use of mineral fertilizers is only given statewide. Therefore, some elements of the nitrogen balance need to be estimated based on agricultural statistics. Hitherto, statistics from the Federal Statistical Office and the statistical offices of the 16 federal states of Germany were used to calculate the soil surface balance annually for the spatial resolution of the 402 districts of Germany (mean size 890 km2). In contrast, this study presents an approach to estimate the nitrogen surplus at a much higher spatial resolution by using the comprehensive Agricultural census data collected in 2010 providing data for 326000 agricultural holdings. This resulted in a nitrogen surplus map with a 5 km x 5 km grid which was subsequently used to calculate the nitrogen concentration of percolation water. This provides a considerably more detailed insight on regions where the groundwater is particularly vulnerable to nitrate pollution and appropriate measures are most needed.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wojciech, Blachucki

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

Wave Processes in Arctic Seas, Observed from TerraSAR-X

DTIC Science & Technology

2015-09-30

Susanne Lehner German Aerospace Center Maritime Safety and Security Lab Henrich-Focke-Str. 4 28199 Bremen Germany phone: 0049 421/ 24420...of high resolution sea state forecast models in the German Bight, The International Archives of the Photogrammetry, Remote Sensing and Spatial

High Quality Data for Grid Integration Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clifton, Andrew; Draxl, Caroline; Sengupta, Manajit

As variable renewable power penetration levels increase in power systems worldwide, renewable integration studies are crucial to ensure continued economic and reliable operation of the power grid. The existing electric grid infrastructure in the US in particular poses significant limitations on wind power expansion. In this presentation we will shed light on requirements for grid integration studies as far as wind and solar energy are concerned. Because wind and solar plants are strongly impacted by weather, high-resolution and high-quality weather data are required to drive power system simulations. Future data sets will have to push limits of numerical weather predictionmore » to yield these high-resolution data sets, and wind data will have to be time-synchronized with solar data. Current wind and solar integration data sets are presented. The Wind Integration National Dataset (WIND) Toolkit is the largest and most complete grid integration data set publicly available to date. A meteorological data set, wind power production time series, and simulated forecasts created using the Weather Research and Forecasting Model run on a 2-km grid over the continental United States at a 5-min resolution is now publicly available for more than 126,000 land-based and offshore wind power production sites. The National Solar Radiation Database (NSRDB) is a similar high temporal- and spatial resolution database of 18 years of solar resource data for North America and India. The need for high-resolution weather data pushes modeling towards finer scales and closer synchronization. We also present how we anticipate such datasets developing in the future, their benefits, and the challenges with using and disseminating such large amounts of data.« less

Whole-central nervous system functional imaging in larval Drosophila

PubMed Central

Lemon, William C.; Pulver, Stefan R.; Höckendorf, Burkhard; McDole, Katie; Branson, Kristin; Freeman, Jeremy; Keller, Philipp J.

2015-01-01

Understanding how the brain works in tight concert with the rest of the central nervous system (CNS) hinges upon knowledge of coordinated activity patterns across the whole CNS. We present a method for measuring activity in an entire, non-transparent CNS with high spatiotemporal resolution. We combine a light-sheet microscope capable of simultaneous multi-view imaging at volumetric speeds 25-fold faster than the state-of-the-art, a whole-CNS imaging assay for the isolated Drosophila larval CNS and a computational framework for analysing multi-view, whole-CNS calcium imaging data. We image both brain and ventral nerve cord, covering the entire CNS at 2 or 5 Hz with two- or one-photon excitation, respectively. By mapping network activity during fictive behaviours and quantitatively comparing high-resolution whole-CNS activity maps across individuals, we predict functional connections between CNS regions and reveal neurons in the brain that identify type and temporal state of motor programs executed in the ventral nerve cord. PMID:26263051

Structure of the vacuolar H+-ATPase rotary motor reveals new mechanistic insights.

PubMed

Rawson, Shaun; Phillips, Clair; Huss, Markus; Tiburcy, Felix; Wieczorek, Helmut; Trinick, John; Harrison, Michael A; Muench, Stephen P

2015-03-03

Vacuolar H(+)-ATPases are multisubunit complexes that operate with rotary mechanics and are essential for membrane proton transport throughout eukaryotes. Here we report a ∼ 1 nm resolution reconstruction of a V-ATPase in a different conformational state from that previously reported for a lower-resolution yeast model. The stator network of the V-ATPase (and by implication that of other rotary ATPases) does not change conformation in different catalytic states, and hence must be relatively rigid. We also demonstrate that a conserved bearing in the catalytic domain is electrostatic, contributing to the extraordinarily high efficiency of rotary ATPases. Analysis of the rotor axle/membrane pump interface suggests how rotary ATPases accommodate different c ring stoichiometries while maintaining high efficiency. The model provides evidence for a half channel in the proton pump, supporting theoretical models of ion translocation. Our refined model therefore provides new insights into the structure and mechanics of the V-ATPases. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

First high resolution analysis of the 3ν2 and 3ν2 -ν2 bands of 32S16O2

NASA Astrophysics Data System (ADS)

Ulenikov, O. N.; Bekhtereva, E. S.; Gromova, O. V.; Berezkin, K. B.; Horneman, V.-M.; Sydow, C.; Maul, C.; Bauerecker, S.

2017-11-01

The second bending overtone band 3ν2 of sulfur dioxide has been studied for the first time with high resolution rotation-vibration spectroscopy. The 1530 transitions involving 728 upper state energy levels with Jmax.= 53 and Kamax . = 15 have been assigned to the 3ν2 band. The 746 transitions belonging to the 3ν2 -ν2 "hot" band have been also assigned in the region of 950-1100 cm-1. For the analysis of the assigned transitions, an effective Hamiltonian of an isolated (030) vibrational state (the Watson operator in A-reduction and Ir representation) was used. Set of 9 varied parameters was determined which reproduce the initial experimental data with the drms deviations of 9.0 ×10-4 cm-1 and 9.8 ×10-4 cm-1 for the 3ν2 and 3ν2 -ν2 bands, which are comparable with the experimental uncertainties.

In vivo biochemistry: quantifying ion and metabolite levels in individual cells or cultures of yeast.

PubMed

Bermejo, Clara; Ewald, Jennifer C; Lanquar, Viviane; Jones, Alexander M; Frommer, Wolf B

2011-08-15

Over the past decade, we have learned that cellular processes, including signalling and metabolism, are highly compartmentalized, and that relevant changes in metabolic state can occur at sub-second timescales. Moreover, we have learned that individual cells in populations, or as part of a tissue, exist in different states. If we want to understand metabolic processes and signalling better, it will be necessary to measure biochemical and biophysical responses of individual cells with high temporal and spatial resolution. Fluorescence imaging has revolutionized all aspects of biology since it has the potential to provide information on the cellular and subcellular distribution of ions and metabolites with sub-second time resolution. In the present review we summarize recent progress in quantifying ions and metabolites in populations of yeast cells as well as in individual yeast cells with the help of quantitative fluorescent indicators, namely FRET metabolite sensors. We discuss the opportunities and potential pitfalls and the controls that help preclude misinterpretation. © The Authors Journal compilation © 2011 Biochemical Society

High-resolution X-ray absorption spectroscopy as a probe of crystal-field and covalency effects in actinide compounds

DOE PAGES

Butorin, Sergei M.; Kvashnina, Kristina O.; Vegelius, Johan R.; ...

2016-07-01

Applying the high-energy resolution fluorescence-detection (HERFD) mode of X-ray absorption spectroscopy (XAS), we were able to probe, for the first time to our knowledge, the crystalline electric field (CEF) splittings of the 5f shell directly in the HERFD-XAS spectra of actinides. Using ThO 2 as an example, data measured at the Th 3d edge were interpreted within the framework of the Anderson impurity model. Because the charge-transfer satellites were also resolved in the HERFD-XAS spectra, the analysis of these satellites revealed that ThO 2 is not an ionic compound as previously believed. The Th 6d occupancy in the ground statemore » was estimated to be twice that of the Th 5f states. Here, we demonstrate that HERFD-XAS allows for characterization of the CEF interaction and degree of covalency in the ground state of actinide compounds as it is extensively done for 3d transition metal systems.« less

High-resolution threshold photoionization of N sub 2 O

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiedmann, R.T.; Grant, E.R.; Tonkyn, R.G.

1991-07-15

Pulsed field ionization (PFI) has been used in conjunction with a coherent vuv source to obtain high-resolution threshold photoelectron spectra for the (000), (010), (020), and (100) vibrational states of the N{sub 2}O{sup +} cation. Simulations for the rotational profiles of each vibronic level were obtained by fitting the Buckingham--Orr--Sichel equations (A. D. Buckingham, B. J. Orr, and J. M. Sichel, Philos. Trans. R. Soc. London, Ser. A {bold 268}, 147 (1970)) using accurate spectroscopic constants for the ground states of the neutral and the ion. The relative branch intensities are interpreted in terms of the partial waves of themore » outgoing photoelectron to which the ionic core is coupled and in terms of the angular momentum transferred to the core. The PFI technique also allows us to report an improved value for the ionization potential of N{sub 2}O of 103 963{plus minus}5 cm{sup {minus}1}.« less

A Dynamic Landsat Derived Normalized Difference Vegetation Index (NDVI) Product for the Conterminous United States

DOE PAGES

Robinson, Nathaniel; Allred, Brady; Jones, Matthew; ...

2017-08-21

Satellite derived vegetation indices (VIs) are broadly used in ecological research, ecosystem modeling, and land surface monitoring. The Normalized Difference Vegetation Index (NDVI), perhaps the most utilized VI, has countless applications across ecology, forestry, agriculture, wildlife, biodiversity, and other disciplines. Calculating satellite derived NDVI is not always straight-forward, however, as satellite remote sensing datasets are inherently noisy due to cloud and atmospheric contamination, data processing failures, and instrument malfunction. Readily available NDVI products that account for these complexities are generally at coarse resolution; high resolution NDVI datasets are not conveniently accessible and developing them often presents numerous technical and methodologicalmore » challenges. Here, we address this deficiency by producing a Landsat derived, high resolution (30 m), long-term (30+ years) NDVI dataset for the conterminous United States. We use Google Earth Engine, a planetary-scale cloud-based geospatial analysis platform, for processing the Landsat data and distributing the final dataset. We use a climatology driven approach to fill missing data and validate the dataset with established remote sensing products at multiple scales. We provide access to the composites through a simple web application, allowing users to customize key parameters appropriate for their application, question, and region of interest.« less

A Dynamic Landsat Derived Normalized Difference Vegetation Index (NDVI) Product for the Conterminous United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robinson, Nathaniel; Allred, Brady; Jones, Matthew

Satellite derived vegetation indices (VIs) are broadly used in ecological research, ecosystem modeling, and land surface monitoring. The Normalized Difference Vegetation Index (NDVI), perhaps the most utilized VI, has countless applications across ecology, forestry, agriculture, wildlife, biodiversity, and other disciplines. Calculating satellite derived NDVI is not always straight-forward, however, as satellite remote sensing datasets are inherently noisy due to cloud and atmospheric contamination, data processing failures, and instrument malfunction. Readily available NDVI products that account for these complexities are generally at coarse resolution; high resolution NDVI datasets are not conveniently accessible and developing them often presents numerous technical and methodologicalmore » challenges. Here, we address this deficiency by producing a Landsat derived, high resolution (30 m), long-term (30+ years) NDVI dataset for the conterminous United States. We use Google Earth Engine, a planetary-scale cloud-based geospatial analysis platform, for processing the Landsat data and distributing the final dataset. We use a climatology driven approach to fill missing data and validate the dataset with established remote sensing products at multiple scales. We provide access to the composites through a simple web application, allowing users to customize key parameters appropriate for their application, question, and region of interest.« less

High-Resolution THz Measurements of BrO Generated in AN Inductively Coupled Plasma

NASA Astrophysics Data System (ADS)

Nemchick, Deacon J.; Drouin, Brian

2017-06-01

Building upon the foundation provided by previous work, the X_{1}^{2}Π_{3/2} and X_{2}^{2}Π_{1/2} states of the transient radical, BrO, were interrogated in previously unprobed spectral regions (0.5 to 1.7 THz) by employing JPL developed high-resolution cascaded frequency multiplier sources. Like other members of the halogen monoxides (XO), this species has been the target of several recent atmospheric remote sensing studies and is a known participant in a catalytic ozone degradation cycle. For the current work, BrO is generated in an inductively coupled plasma under dynamic flow conditions and rotational lines are observed directly at their Doppler-limited resolution. New spectral transitions including those owing to both the ground (ν=0) and excited (ν=1 and 2) vibrational states of isotopologues composed of permutations of natural abundance ^{16}O, ^{18}O, ^{79}Br, and ^{81}Br are fit to a global Hamiltonian containing both fine and hyperfine terms. In addition to further refining existing spectroscopic parameters, new observations will be made available to remote detection communities through addition to the JPL catalog. New findings will be discussed along with future plans to extend these studies to other halogen monoxides (X=Cl and I) and the more massive halogen dioxides (OXO & XOO).

Atmospheric pressure and temperature profiling using near IR differential absorption lidar

NASA Technical Reports Server (NTRS)

Korb, C. L.; Schwemmer, G. K.; Dombrowski, M.; Weng, C. Y.

1983-01-01

The present investigation is concerned with differential absorption lidar techniques for remotely measuring the atmospheric temperature and pressure profile, surface pressure, and cloud top pressure-height. The procedure used in determining the pressure is based on the conduction of high-resolution measurements of absorption in the wings of lines in the oxygen A band. Absorption with respect to these areas is highly pressure sensitive in connection with the mechanism of collisional line broadening. The method of temperature measurement utilizes a determination of the absorption at the center of a selected line in the oxygen A band which originates from a quantum state with high ground state energy.

Near-Continuous Profiling of Temperature, Moisture, and Atmospheric Stability Using the Atmospheric Emitted Radiance Interferometer (AERI).

NASA Astrophysics Data System (ADS)

Feltz, W. F.; Smith, W. L.; Howell, H. B.; Knuteson, R. O.; Woolf, H.; Revercomb, H. E.

2003-05-01

The Department of Energy Atmospheric Radiation Measurement Program (ARM) has funded the development and installation of five ground-based atmospheric emitted radiance interferometer (AERI) systems at the Southern Great Plains (SGP) site. The purpose of this paper is to provide an overview of the AERI instrument, improvement of the AERI temperature and moisture retrieval technique, new profiling utility, and validation of high-temporal-resolution AERI-derived stability indices important for convective nowcasting. AERI systems have been built at the University of Wisconsin-Madison, Madison, Wisconsin, and deployed in the Oklahoma-Kansas area collocated with National Oceanic and Atmospheric Administration 404-MHz wind profilers at Lamont, Vici, Purcell, and Morris, Oklahoma, and Hillsboro, Kansas. The AERI systems produce absolutely calibrated atmospheric infrared emitted radiances at one-wavenumber resolution from 3 to 20 m at less than 10-min temporal resolution. The instruments are robust, are automated in the field, and are monitored via the Internet in near-real time. The infrared radiances measured by the AERI systems contain meteorological information about the vertical structure of temperature and water vapor in the planetary boundary layer (PBL; 0-3 km). A mature temperature and water vapor retrieval algorithm has been developed over a 10-yr period that provides vertical profiles at less than 10-min temporal resolution to 3 km in the PBL. A statistical retrieval is combined with the hourly Geostationary Operational Environmental Satellite (GOES) sounder water vapor or Rapid Update Cycle, version 2, numerical weather prediction (NWP) model profiles to provide a nominal hybrid first guess of temperature and moisture to the AERI physical retrieval algorithm. The hourly satellite or NWP data provide a best estimate of the atmospheric state in the upper PBL; the AERI radiances provide the mesoscale temperature and moisture profile correction in the PBL to the large-scale GOES and NWP model profiles at high temporal resolution. The retrieval product has been named AERIplus because the first guess used for the mathematical physical inversion uses an optimal combination of statistical climatological, satellite, and numerical model data to provide a best estimate of the atmospheric state. The AERI physical retrieval algorithm adjusts the boundary layer temperature and moisture structure provided by the hybrid first guess to fit the observed AERI downwelling radiance measurement. This provides a calculated AERI temperature and moisture profile using AERI-observed radiances `plus' the best-known atmospheric state above the boundary layer using NWP or satellite data. AERIplus retrieval accuracy for temperature has been determined to be better than 1 K, and water vapor retrieval accuracy is approximately 5% in absolute water vapor when compared with well-calibrated radiosondes from the surface to an altitude of 3 km. Because AERI can monitor the thermodynamics where the atmosphere usually changes most rapidly, atmospheric stability tendency information is readily available from the system. High-temporal-resolution retrieval of convective available potential energy, convective inhibition, and PBL equivalent potential temperature e are provided in near-real time from all five AERI systems at the ARM SGP site, offering a unique look at the atmospheric state. This new source of meteorological data has shown excellent skill in detecting rapid synoptic and mesoscale meteorological changes within clear atmospheric conditions. This method has utility in nowcasting temperature inversion strength and destabilization caused by e advection. This high-temporal-resolution monitoring of rapid atmospheric destabilization is especially important for nowcasting severe convection.

High Spatial Resolution of Atmospheric Particle Mixing State and Its Links to Particle Evolution in a Metropolitan Area

NASA Astrophysics Data System (ADS)

Ye, Q.; Gu, P.; Li, H.; Robinson, E. S.; Apte, J.; Sullivan, R. C.; Robinson, A. L.; Presto, A. A.; Donahue, N.

2017-12-01

Traditional air quality studies in urban areas have mostly relied on very few monitoring locations either at urban background sites or at roadside sites.However, air pollution is highly complex and dynamic and will undergo complicated transformations. Therefore, results from one or two monitoring sites may not be sufficient to address the spatial gradients of pollutants and their evolution after atmosphere processing on a local scale. Our study, as part of the Center for Air, Climate, and Energy Solutions, performed stratified mobile sampling of atmospheric particulate matter with high spatial resolution to address intra-city variability of atmospheric particle composition and mixing state. A suite of comprehensive real-time instrumentations including a state-of-the-art aerosol mass spectrometer with single particle measurement capability are deployed on the mobile platform. Our sampling locations covered a wide variety of places with substantial differences in emissions and land use types including tunnels, inter-state highways, commercial areas, residential neighborhood, parks, as well as locations upwind and downwind of the city center. Our results show that particles from traffic emissions and restaurant cookings are two major contributors to fresh particles in the urban environment. In addition, there are large spatial variabilities of source-specific particles and we identify the relevant physicochemical processes governing transformation of particle composition, size and mixing state. We also combine our results with demographic data to study population exposure to particles of specific sources. This work will help evaluate the performance of existing modeling tools for air quality and population exposure studies.

Simultaneous observations of structure function parameter of refractive index using a high-resolution radar and the DataHawk small airborne measurement system

NASA Astrophysics Data System (ADS)

Scipión, Danny E.; Lawrence, Dale A.; Milla, Marco A.; Woodman, Ronald F.; Lume, Diego A.; Balsley, Ben B.

2016-09-01

The SOUSY (SOUnding SYstem) radar was relocated to the Jicamarca Radio Observatory (JRO) near Lima, Peru, in 2000, where the radar controller and acquisition system were upgraded with state-of-the-art parts to take full advantage of its potential for high-resolution atmospheric sounding. Due to its broad bandwidth (4 MHz), it is able to characterize clear-air backscattering with high range resolution (37.5 m). A campaign conducted at JRO in July 2014 aimed to characterize the lower troposphere with a high temporal resolution (8.1 Hz) using the DataHawk (DH) small unmanned aircraft system, which provides in situ atmospheric measurements at scales as small as 1 m in the lower troposphere and can be GPS-guided to obtain measurements within the beam of the radar. This was a unique opportunity to make coincident observations by both systems and to directly compare their in situ and remotely sensed parameters. Because SOUSY only points vertically, it is only possible to retrieve vertical radar profiles caused by changes in the refractive index within the resolution volume. Turbulent variations due to scattering are described by the structure function parameter of refractive index Cn2. Profiles of Cn2 from the DH are obtained by combining pressure, temperature, and relative humidity measurements along the helical trajectory and integrated at the same scale as the radar range resolution. Excellent agreement is observed between the Cn2 estimates obtained from the DH and SOUSY in the overlapping measurement regime from 1200 m up to 4200 m above sea level, and this correspondence provides the first accurate calibration of the SOUSY radar for measuring Cn2.

Exploring image data assimilation in the prospect of high-resolution satellite data

NASA Astrophysics Data System (ADS)

Verron, J. A.; Duran, M.; Gaultier, L.; Brankart, J. M.; Brasseur, P.

2016-02-01

Many recent works show the key importance of studying the ocean at fine scales including the meso- and submesoscales. Satellite observations such as ocean color data provide informations on a wide range of scales but do not directly provide information on ocean dynamics. Satellite altimetry provide informations on the ocean dynamic topography (SSH) but so far with a limited resolution in space and even more, in time. However, in the near future, high-resolution SSH data (e.g. SWOT) will give a vision of the dynamic topography at such fine space resolution. This raises some challenging issues for data assimilation in physical oceanography: develop reliable methodology to assimilate high resolution data, make integrated use of various data sets including biogeochemical data, and even more simply, solve the challenge of handling large amont of data and huge state vectors. In this work, we propose to consider structured information rather than pointwise data. First, we take an image data assimilation approach in studying the feasibility of inverting tracer observations from Sea Surface Temperature and/or Ocean Color datasets, to improve the description of mesoscale dynamics provided by altimetric observations. Finite Size Lyapunov Exponents are used as an image proxy. The inverse problem is formulated in a Bayesian framework and expressed in terms of a cost function measuring the misfits between the two images. Second, we explore the inversion of SWOT-like high resolution SSH data and more especially the various possible proxies of the actual SSH that could be used to control the ocean circulation at various scales. One focus is made on controlling the subsurface ocean from surface only data. A key point lies in the errors and uncertainties that are associated to SWOT data.

Evaluating the role of land cover and climate uncertainties in computing gross primary production in Hawaiian Island ecosystems

PubMed Central

Selmants, Paul C.; Moreno, Alvaro; Running, Steve W.; Giardina, Christian P.

2017-01-01

Gross primary production (GPP) is the Earth’s largest carbon flux into the terrestrial biosphere and plays a critical role in regulating atmospheric chemistry and global climate. The Moderate Resolution Imaging Spectrometer (MODIS)-MOD17 data product is a widely used remote sensing-based model that provides global estimates of spatiotemporal trends in GPP. When the MOD17 algorithm is applied to regional scale heterogeneous landscapes, input data from coarse resolution land cover and climate products may increase uncertainty in GPP estimates, especially in high productivity tropical ecosystems. We examined the influence of using locally specific land cover and high-resolution local climate input data on MOD17 estimates of GPP for the State of Hawaii, a heterogeneous and discontinuous tropical landscape. Replacing the global land cover data input product (MOD12Q1) with Hawaii-specific land cover data reduced statewide GPP estimates by ~8%, primarily because the Hawaii-specific land cover map had less vegetated land area compared to the global land cover product. Replacing coarse resolution GMAO climate data with Hawaii-specific high-resolution climate data also reduced statewide GPP estimates by ~8% because of the higher spatial variability of photosynthetically active radiation (PAR) in the Hawaii-specific climate data. The combined use of both Hawaii-specific land cover and high-resolution Hawaii climate data inputs reduced statewide GPP by ~16%, suggesting equal and independent influence on MOD17 GPP estimates. Our sensitivity analyses within a heterogeneous tropical landscape suggest that refined global land cover and climate data sets may contribute to an enhanced MOD17 product at a variety of spatial scales. PMID:28886187

Evaluating the role of land cover and climate uncertainties in computing gross primary production in Hawaiian Island ecosystems

USGS Publications Warehouse

Kimball, Heather L.; Selmants, Paul; Moreno, Alvaro; Running Steve W,; Giardina, Christian P.

2017-01-01

Gross primary production (GPP) is the Earth’s largest carbon flux into the terrestrial biosphere and plays a critical role in regulating atmospheric chemistry and global climate. The Moderate Resolution Imaging Spectrometer (MODIS)-MOD17 data product is a widely used remote sensing-based model that provides global estimates of spatiotemporal trends in GPP. When the MOD17 algorithm is applied to regional scale heterogeneous landscapes, input data from coarse resolution land cover and climate products may increase uncertainty in GPP estimates, especially in high productivity tropical ecosystems. We examined the influence of using locally specific land cover and high-resolution local climate input data on MOD17 estimates of GPP for the State of Hawaii, a heterogeneous and discontinuous tropical landscape. Replacing the global land cover data input product (MOD12Q1) with Hawaii-specific land cover data reduced statewide GPP estimates by ~8%, primarily because the Hawaii-specific land cover map had less vegetated land area compared to the global land cover product. Replacing coarse resolution GMAO climate data with Hawaii-specific high-resolution climate data also reduced statewide GPP estimates by ~8% because of the higher spatial variability of photosynthetically active radiation (PAR) in the Hawaii-specific climate data. The combined use of both Hawaii-specific land cover and high-resolution Hawaii climate data inputs reduced statewide GPP by ~16%, suggesting equal and independent influence on MOD17 GPP estimates. Our sensitivity analyses within a heterogeneous tropical landscape suggest that refined global land cover and climate data sets may contribute to an enhanced MOD17 product at a variety of spatial scales.

Evaluating the role of land cover and climate uncertainties in computing gross primary production in Hawaiian Island ecosystems.

PubMed

Kimball, Heather L; Selmants, Paul C; Moreno, Alvaro; Running, Steve W; Giardina, Christian P

2017-01-01

Gross primary production (GPP) is the Earth's largest carbon flux into the terrestrial biosphere and plays a critical role in regulating atmospheric chemistry and global climate. The Moderate Resolution Imaging Spectrometer (MODIS)-MOD17 data product is a widely used remote sensing-based model that provides global estimates of spatiotemporal trends in GPP. When the MOD17 algorithm is applied to regional scale heterogeneous landscapes, input data from coarse resolution land cover and climate products may increase uncertainty in GPP estimates, especially in high productivity tropical ecosystems. We examined the influence of using locally specific land cover and high-resolution local climate input data on MOD17 estimates of GPP for the State of Hawaii, a heterogeneous and discontinuous tropical landscape. Replacing the global land cover data input product (MOD12Q1) with Hawaii-specific land cover data reduced statewide GPP estimates by ~8%, primarily because the Hawaii-specific land cover map had less vegetated land area compared to the global land cover product. Replacing coarse resolution GMAO climate data with Hawaii-specific high-resolution climate data also reduced statewide GPP estimates by ~8% because of the higher spatial variability of photosynthetically active radiation (PAR) in the Hawaii-specific climate data. The combined use of both Hawaii-specific land cover and high-resolution Hawaii climate data inputs reduced statewide GPP by ~16%, suggesting equal and independent influence on MOD17 GPP estimates. Our sensitivity analyses within a heterogeneous tropical landscape suggest that refined global land cover and climate data sets may contribute to an enhanced MOD17 product at a variety of spatial scales.

Advanced continuous cultivation methods for systems microbiology.

PubMed

Adamberg, Kaarel; Valgepea, Kaspar; Vilu, Raivo

2015-09-01

Increasing the throughput of systems biology-based experimental characterization of in silico-designed strains has great potential for accelerating the development of cell factories. For this, analysis of metabolism in the steady state is essential as only this enables the unequivocal definition of the physiological state of cells, which is needed for the complete description and in silico reconstruction of their phenotypes. In this review, we show that for a systems microbiology approach, high-resolution characterization of metabolism in the steady state--growth space analysis (GSA)--can be achieved by using advanced continuous cultivation methods termed changestats. In changestats, an environmental parameter is continuously changed at a constant rate within one experiment whilst maintaining cells in the physiological steady state similar to chemostats. This increases the resolution and throughput of GSA compared with chemostats, and, moreover, enables following of the dynamics of metabolism and detection of metabolic switch-points and optimal growth conditions. We also describe the concept, challenge and necessary criteria of the systematic analysis of steady-state metabolism. Finally, we propose that such systematic characterization of the steady-state growth space of cells using changestats has value not only for fundamental studies of metabolism, but also for systems biology-based metabolic engineering of cell factories.

XPEEM valence state imaging of mineral micro-intergrowths with a spatial resolution of 100nm

NASA Astrophysics Data System (ADS)

Smith, A. D.; Schofield, P. F.; Scholl, A.; Pattrick, R. A. D.; Bridges, J. C.

2003-03-01

The crystal chemistry and textural relationships of minerals hold a vast amount of information relating to the formation, history and stability of natural materials. The application of soft X-ray spectroscopy to mineralogical material has revealed that 2p (L{2,3}) spectra provide a sensitive fingerprint of the electronic states of 3d metals. In bulk powdered samples much of the textural and microstructural information is lost, but the area-selectivity capability of X-ray Photo-Emission Electron Microscopy (XPEEM) provides the ability to obtain valence state information from mineral intergrowths with a submicron spatial resolution. Using the state-of-the-art PEEM2 facility on beamline 7.3.1.1 at the Advanced Light Source, Berkeley, USA, a range of minerals, mineral intergrowths and mineralogical textures have been studied for a broad suite of geological, planetary and environmental science materials. High-quality, multi-element valence images have been obtained showing the distribution/variation of the metal valence states across single grains or mineral intergrowths/textures at the l00 nm scale and quantitative valence state ratios can be obtained from areas of 0.01 μ m^2.

Fully integrated sub 100ps photon counting platform

NASA Astrophysics Data System (ADS)

Buckley, S. J.; Bellis, S. J.; Rosinger, P.; Jackson, J. C.

2007-02-01

Current state of the art high resolution counting modules, specifically designed for high timing resolution applications, are largely based on a computer card format. This has tended to result in a costly solution that is restricted to the computer it resides in. We describe a four channel timing module that interfaces to a computer via a USB port and operates with a resolution of less than 100 picoseconds. The core design of the system is an advanced field programmable gate array (FPGA) interfacing to a precision time interval measurement module, mass memory block and a high speed USB 2.0 serial data port. The FPGA design allows the module to operate in a number of modes allowing both continuous recording of photon events (time-tagging) and repetitive time binning. In time-tag mode the system reports, for each photon event, the high resolution time along with the chronological time (macro time) and the channel ID. The time-tags are uploaded in real time to a host computer via a high speed USB port allowing continuous storage to computer memory of up to 4 millions photons per second. In time-bin mode, binning is carried out with count rates up to 10 million photons per second. Each curve resides in a block of 128,000 time-bins each with a resolution programmable down to less than 100 picoseconds. Each bin has a limit of 65535 hits allowing autonomous curve recording until a bin reaches the maximum count or the system is commanded to halt. Due to the large memory storage, several curves/experiments can be stored in the system prior to uploading to the host computer for analysis. This makes this module ideal for integration into high timing resolution specific applications such as laser ranging and fluorescence lifetime imaging using techniques such as time correlated single photon counting (TCSPC).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fang, Li; Xiong, Hui; Kukk, Edwin

Molecular dynamics is of fundamental interest in natural science research. The capability of investigating molecular dynamics is one of the various motivations for ultrafast optics. Here, we present our investigation of photoionization and nuclear dynamics in methyl iodine (CH 3I) molecule with an X-ray pump X-ray probe scheme. The pump–probe experiment was realized with a two-mirror X-ray split and delay apparatus. Time-of-flight mass spectra at various pump–probe delay times were recorded to obtain the time profile for the creation of high charge states via sequential ionization and for molecular dissociation. We observed high charge states of atomic iodine up tomore » 29+, and visualized the evolution of creating these high atomic ion charge states, including their population suppression and enhancement as the arrival time of the second X-ray pulse was varied. We also show the evolution of the kinetics of the high charge states upon the timing of their creation during the ionization-dissociation coupled dynamics. We demonstrate the implementation of X-ray pump–probe methodology for investigating X-ray induced molecular dynamics with femtosecond temporal resolution. The results indicate the footprints of ionization that lead to high charge states, probing the long-range potential curves of the high charge states.« less

Directional Sensitivity in Light-Mass Dark Matter Searches with Single-Electron-Resolution Ionization Detectors

NASA Astrophysics Data System (ADS)

Kadribasic, Fedja; Mirabolfathi, Nader; Nordlund, Kai; Sand, Andrea E.; Holmström, Eero; Djurabekova, Flyura

2018-03-01

We propose a method using solid state detectors with directional sensitivity to dark matter interactions to detect low-mass weakly interacting massive particles (WIMPs) originating from galactic sources. In spite of a large body of literature for high-mass WIMP detectors with directional sensitivity, no available technique exists to cover WIMPs in the mass range <1 GeV /c2 . We argue that single-electron-resolution semiconductor detectors allow for directional sensitivity once properly calibrated. We examine the commonly used semiconductor material response to these low-mass WIMP interactions.

Dynamical characteristics of Rydberg electrons released by a weak electric field

DOE PAGES

Diesen, Elias; Saalmann, Ulf; Richter, Martin; ...

2016-04-08

This paper discuss the dynamics of ultraslow electrons in the combined potential of an ionic core and a static electric field. With state-of-the-art detection it is possible to create such electrons through strong intense-field photoabsorption and to detect them via high-resolution time-of-flight spectroscopy despite their very low kinetic energy. The characteristic feature of their momentum spectrum, which emerges at the same position for different laser orientations, is derived and could be revealed experimentally with an energy resolution of the order of 1 meV.

Laboratory study supporting the interpretation of Solar Dynamics Observatory data

DOE PAGES

Trabert, E.; Beiersdorfer, P.

2015-01-29

High-resolution extreme ultraviolet spectra of ions in an electron beam ion trap are investigated as a laboratory complement of the moderate-resolution observation bands of the AIA experiment on board the Solar Dynamics Observatory (SDO) spacecraft. Here, the latter observations depend on dominant iron lines of various charge states which in combination yield temperature information on the solar plasma. Our measurements suggest additions to the spectral models that are used in the SDO data interpretation. In the process, we also note a fair number of inconsistencies among the wavelength reference data bases.

15 CFR 970.302 - Procedures and criteria for resolving conflicts.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Procedures for Applications Based on Exploration Commenced Before June 28, 1980; Resolution of Conflicts... resolving conflicts. (a) General. This section governs the resolution of all conflicts between or among... conflict resolution procedures in force between the United States and its reciprocating states pursuant to...

Structural studies of Proteus mirabilis catalase in its ground state, oxidized state and in complex with formic acid.

PubMed

Andreoletti, Pierre; Pernoud, Anaïs; Sainz, Germaine; Gouet, Patrice; Jouve, Hélène Marie

2003-12-01

The structure of Proteus mirabilis catalase in complex with an inhibitor, formic acid, has been solved at 2.3 A resolution. Formic acid is a key ligand of catalase because of its ability to react with the ferric enzyme, giving a high-spin iron complex. Alternatively, it can react with two transient oxidized intermediates of the enzymatic mechanism, compounds I and II. In this work, the structures of native P. mirabilis catalase (PMC) and compound I have also been determined at high resolution (2.0 and 2.5 A, respectively) from frozen crystals. Comparisons between these three PMC structures show that a water molecule present at a distance of 3.5 A from the haem iron in the resting state is absent in the formic acid complex, but reappears in compound I. In addition, movements of solvent molecules are observed during formation of compound I in a cavity located away from the active site, in which a glycerol molecule is replaced by a sulfate. These results give structural insights into the movement of solvent molecules, which may be important in the enzymatic reaction.

Excitonic Energy Landscape of the Y16F Mutant of the Chlorobium tepidum Fenna-Matthews-Olson (FMO) Complex: High Resolution Spectroscopic and Modeling Studies.

PubMed

Khmelnitskiy, Anton; Saer, Rafael G; Blankenship, Robert E; Jankowiak, Ryszard

2018-04-12

We report high-resolution (low-temperature) absorption, emission, and nonresonant/resonant hole-burned (HB) spectra and results of excitonic calculations using a non-Markovian reduced density matrix theory (with an improved algorithm for parameter optimization in heterogeneous samples) obtained for the Y16F mutant of the Fenna-Matthews-Olson (FMO) trimer from the green sulfur bacterium Chlorobium tepidum. We show that the Y16F mutant is a mixture of FMO complexes with three independent low-energy traps (located near 817, 821, and 826 nm), in agreement with measured composite emission and HB spectra. Two of these traps belong to mutated FMO subpopulations characterized by significantly modified low-energy excitonic states. Hamiltonians for the two major subpopulations (Sub 821 and Sub 817 ) provide new insight into extensive changes induced by the single-point mutation in the vicinity of BChl 3 (where tyrosine Y16 was replaced with phenylalanine F16). The average decay time(s) from the higher exciton state(s) in the Y16F mutant depends on frequency and occurs on a picosecond time scale.

Simultaneous broadband observations and high-resolution X-ray spectroscopy of the transitional millisecond pulsar PSR J1023+0038

NASA Astrophysics Data System (ADS)

Coti Zelati, F.; Campana, S.; Braito, V.; Baglio, M. C.; D'Avanzo, P.; Rea, N.; Torres, D. F.

2018-03-01

We report on the first simultaneous XMM-Newton, NuSTAR, and Swift observations of the transitional millisecond pulsar PSR J1023+0038 in the X-ray active state. Our multi-wavelength campaign allowed us to investigate with unprecedented detail possible spectral variability over a broad energy range in the X-rays, as well as correlations and lags among emissions in different bands. The soft and hard X-ray emissions are significantly correlated, with no lags between the two bands. On the other hand, the X-ray emission does not correlate with the UV emission. We refine our model for the observed mode switching in terms of rapid transitions between a weak propeller regime and a rotation-powered radio pulsar state, and report on a detailed high-resolution X-ray spectroscopy using all XMM-Newton Reflection Grating Spectrometer data acquired since 2013. We discuss our results in the context of the recent discoveries on the system and of the state of the art simulations on transitional millisecond pulsars, and show how the properties of the narrow emission lines in the soft X-ray spectrum are consistent with an origin within the accretion disc.

Binding patterns of vanadium ions with different valence states to human serum transferrin studied by HPLC/high-resolution ICP-MS.

PubMed

Nagaoka, Megumi Hamano; Yamazaki, Takeshi; Maitani, Tamio

2002-09-06

Vanadium (V) is an essential metal for mammals and has different valence states. In blood, V is bound to serum transferrin (Tf), a glycoprotein which has two metal-binding sites, and carbonate is generally required for the binding. In this study, the binding patterns of V(III), V(IV), and V(V) to human serum Tf (hTf) were analyzed using an HPLC system equipped with an anion-exchange column and directly connected to a high-resolution inductively coupled plasma-mass spectrometer for metal detection (51V). In affinity to hTf, the three ions were ranked V(III)>V(IV)>V(V) in the presence of bicarbonate and V(III) reverse congruent V(IV)>V(V) in the absence. Intermediates in the "open forms" binding to the respective sites were detected at the initial stage. V(IV) and V(V) were bound to the N-lobe site in the "closed form" and "open form," respectively. In the absence of bicarbonate, V ions with respective valence states were bound to hTf in the "open form." In terms of binding to hTf, tri-valent V was most favorable in the presence of bicarbonate.

Hyperspectral imaging polarimeter in the infrared

NASA Astrophysics Data System (ADS)

Jensen, Gary L.; Peterson, James Q.

1998-11-01

The Space Dynamics Laboratory at Utah State University is building an infrared Hyperspectral Imaging Polarimeter (HIP). Designed for high spatial and spectral resolution polarimetry of backscattered sunlight from cloud tops in the 2.7 micrometer water band, it will fly aboard the Flying Infrared Signatures Technology Aircraft (FISTA), an Air Force KC-135. It is a proof-of-concept sensor, combining hyperspectral pushbroom imaging with high speed, solid state polarimetry, using as many off-the-shelf components as possible, and utilizing an optical breadboard design for rapid prototyping. It is based around a 256 X 320 window selectable InSb camera, a solid-state Ferro-electric Liquid Crystal (FLC) polarimeter, and a transmissive diffraction grating.

Toward a 30m resolution time series of historical global urban expansion: exploring variation in North American cities

NASA Astrophysics Data System (ADS)

Stuhlmacher, M.; Wang, C.; Georgescu, M.; Tellman, B.; Balling, R.; Clinton, N. E.; Collins, L.; Goldblatt, R.; Hanson, G.

2016-12-01

Global representations of modern day urban land use and land cover (LULC) extent are becoming increasingly prevalent. Yet considerable uncertainties in the representation of built environment extent (i.e. global classifications generated from 250m resolution MODIS imagery or the United States' National Land Cover Database) remain because of the lack of a systematic, globally consistent methodological approach. We aim to increase resolution, accuracy, and improve upon past efforts by establishing a data-driven definition of the urban landscape, based on Landsat 5, 7 & 8 imagery and ancillary data sets. Continuous and discrete machine learning classification algorithms have been developed in Google Earth Engine (GEE), a powerful online cloud-based geospatial storage and parallel-computing platform. Additionally, thousands of ground truth points have been selected from high resolution imagery to fill in the previous lack of accurate data to be used for training and validation. We will present preliminary classification and accuracy assessments for select cities in the United States and Mexico. Our approach has direct implications for development of projected urban growth that is grounded on realistic identification of urbanizing hot-spots, with consequences for local to regional scale climate change, energy demand, water stress, human health, urban-ecological interactions, and efforts used to prioritize adaptation and mitigation strategies to offset large-scale climate change. Future work to apply the built-up detection algorithm globally and yearly is underway in a partnership between GEE, University of California in San Diego, and Arizona State University.

Detection of potato beetle damage using remote sensing from small unmanned aircraft systems

USDA-ARS?s Scientific Manuscript database

Remote sensing with small unmanned aircraft systems (sUAS) has potential applications in agriculture because low flight altitudes allow image acquisition at very high spatial resolution. We set up experiments at the Oregon State University Hermiston Agricultural Research and Extension Center (HAREC...

Validation of soil moisture ocean salinity (SMOS) satellite soil moisture products

USDA-ARS?s Scientific Manuscript database

The surface soil moisture state controls the partitioning of precipitation into infiltration and runoff. High-resolution observations of soil moisture will lead to improved flood forecasts, especially for intermediate to large watersheds where most flood damage occurs. Soil moisture is also key in d...