Science.gov

Sample records for affected large areas

  1. Large-scale climatic patterns and area affected by mountain pine beetle in British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Macias Fauria, Marc; Johnson, E. A.

    2009-03-01

    We present evidence of high spatial synchrony in an area affected by mountain pine beetle (MPB, Dendroctonus ponderosae) across large distances in British Columbia, Canada, in a study of a spatially explicit database of an area affected by MPB-caused tree mortality for the period 1959-2002. We further show that large-scale climatic patterns (Pacific Decadal Oscillation (PDO) and, to a lesser degree, Arctic Oscillation (AO)) are strongly related to the observed MPB synchrony, and that they probably operate through controlling the frequency of extreme cold winter temperatures that affect MPB larvae survival. A smaller portion of the data's variability is linked to the onset of the two largest outbreaks in the studied period and might be attributed to dispersal from outbreak-prone areas or else to differences in microhabitat (e.g., host availability) in these regions. The onset of a warm PDO phase in 1976 favored MPB outbreaks by reducing the occurrence of extremely low winter temperatures province-wide. Likewise, the exceptionally high and persistent AO values of the late 1980s and 1990s enhanced MPB activity in the southern and northern parts of the region. Summer warmth cannot be discarded as an important agent at smaller scales.

  2. The Large Area Telescope

    SciTech Connect

    Michelson, Peter F.; /KIPAC, Menlo Park /Stanford U., HEPL

    2007-11-13

    The Large Area Telescope (LAT), one of two instruments on the Gamma-ray Large Area Space Telescope (GLAST) mission, is an imaging, wide field-of-view, high-energy pair-conversion telescope, covering the energy range from {approx}20 MeV to more than 300 GeV. The LAT is being built by an international collaboration with contributions from space agencies, high-energy particle physics institutes, and universities in France, Italy, Japan, Sweden, and the United States. The scientific objectives the LAT will address include resolving the high-energy gamma-ray sky and determining the nature of the unidentified gamma-ray sources and the origin of the apparently isotropic diffuse emission observed by EGRET; understanding the mechanisms of particle acceleration in celestial sources, including active galactic nuclei, pulsars, and supernovae remnants; studying the high-energy behavior of gamma-ray bursts and transients; using high-energy gamma-rays to probe the early universe to z {ge} 6; and probing the nature of dark matter. The components of the LAT include a precision silicon-strip detector tracker and a CsI(Tl) calorimeter, a segmented anticoincidence shield that covers the tracker array, and a programmable trigger and data acquisition system. The calorimeter's depth and segmentation enable the high-energy reach of the LAT and contribute significantly to background rejection. The aspect ratio of the tracker (height/width) is 0.4, allowing a large field-of-view and ensuring that nearly all pair-conversion showers initiated in the tracker will pass into the calorimeter for energy measurement. This paper includes a description of each of these LAT subsystems as well as a summary of the overall performance of the telescope.

  3. Large area Czochralski silicon

    NASA Technical Reports Server (NTRS)

    Rea, S. N.; Gleim, P. S.

    1977-01-01

    The overall cost effectiveness of the Czochralski process for producing large-area silicon was determined. The feasibility of growing several 12 cm diameter crystals sequentially at 12 cm/h during a furnace run and the subsequent slicing of the ingot using a multiblade slurry saw were investigated. The goal of the wafering process was a slice thickness of 0.25 mm with minimal kerf. A slice + kerf of 0.56 mm was achieved on 12 cm crystal using both 400 grit B4C and SiC abrasive slurries. Crystal growth experiments were performed at 12 cm diameter in a commercially available puller with both 10 and 12 kg melts. Several modifications to the puller hoz zone were required to achieve stable crystal growth over the entire crystal length and to prevent crystallinity loss a few centimeters down the crystal. The maximum practical growth rate for 12 cm crystal in this puller design was 10 cm/h, with 12 to 14 cm/h being the absolute maximum range at which melt freeze occurred.

  4. Large area bulk superconductors

    DOEpatents

    Miller, Dean J.; Field, Michael B.

    2002-01-01

    A bulk superconductor having a thickness of not less than about 100 microns is carried by a polycrystalline textured substrate having misorientation angles at the surface thereof not greater than about 15.degree.; the bulk superconductor may have a thickness of not less than about 100 microns and a surface area of not less than about 50 cm.sup.2. The textured substrate may have a thickness not less than about 10 microns and misorientation angles at the surface thereof not greater than about 15.degree.. Also disclosed is a process of manufacturing the bulk superconductor and the polycrystalline biaxially textured substrate material.

  5. Large area plasma source

    NASA Technical Reports Server (NTRS)

    Foster, John (Inventor); Patterson, Michael (Inventor)

    2008-01-01

    An all permanent magnet Electron Cyclotron Resonance, large diameter (e.g., 40 cm) plasma source suitable for ion/plasma processing or electric propulsion, is capable of producing uniform ion current densities at its exit plane at very low power (e.g., below 200 W), and is electrodeless to avoid sputtering or contamination issues. Microwave input power is efficiently coupled with an ionizing gas without using a dielectric microwave window and without developing a throat plasma by providing a ferromagnetic cylindrical chamber wall with a conical end narrowing to an axial entrance hole for microwaves supplied on-axis from an open-ended waveguide. Permanent magnet rings are attached inside the wall with alternating polarities against the wall. An entrance magnet ring surrounding the entrance hole has a ferromagnetic pole piece that extends into the chamber from the entrance hole to a continuing second face that extends radially across an inner pole of the entrance magnet ring.

  6. Fermi's Large Area Telescope (LAT)

    NASA Video Gallery

    Fermi’s Large Area Telescope (LAT) is the spacecraft’s main scientificinstrument. This animation shows a gamma ray (purple) entering the LAT,where it is converted into an electron (red) and a...

  7. Large Area Vacuum Deposited Coatings

    SciTech Connect

    Martin, Peter M.

    2003-04-30

    It's easy to make the myriad of types of large area and decorative coatings for granted. We probably don't even think about most of them; the low-e and heat mirror coatings on our windows and car windows, the mirrors in displays, antireflection coatings on windows and displays, protective coatings on aircraft windows, heater coatings on windshields and aircraft windows, solar reflectors, thin film solar cells, telescope mirrors, Hubble mirrors, transparent conductive coatings, and the list goes on. All these products require large deposition systems and chambers. Also, don't forget that large batches of small substrates or parts are coated in large chambers. In order to be cost effective hundreds of ophthalmic lenses, automobile reflectors, display screens, lamp reflectors, cell phone windows, laser reflectors, DWDM filters, are coated in batches.

  8. Large-area lanthanum hexaboride electron emitter

    NASA Astrophysics Data System (ADS)

    Goebel, D. M.; Hirooka, Y.; Sketchley, T. A.

    1985-09-01

    The characteristics of lanthanum-boron thermionic electron emitters are discussed, and a large-area, continuously operating cathode assembly and heater are described. Impurity production and structural problems involving the support of the LaB6 have been eliminated in the presented configuration. The performance of the cathode in a plasma discharge, where surface modification occurs by ion sputtering, is presented. Problem areas which affect lifetime and emission current capability are discussed.

  9. Large area CMOS image sensors

    NASA Astrophysics Data System (ADS)

    Turchetta, R.; Guerrini, N.; Sedgwick, I.

    2011-01-01

    CMOS image sensors, also known as CMOS Active Pixel Sensors (APS) or Monolithic Active Pixel Sensors (MAPS), are today the dominant imaging devices. They are omnipresent in our daily life, as image sensors in cellular phones, web cams, digital cameras, ... In these applications, the pixels can be very small, in the micron range, and the sensors themselves tend to be limited in size. However, many scientific applications, like particle or X-ray detection, require large format, often with large pixels, as well as other specific performance, like low noise, radiation hardness or very fast readout. The sensors are also required to be sensitive to a broad spectrum of radiation: photons from the silicon cut-off in the IR down to UV and X- and gamma-rays through the visible spectrum as well as charged particles. This requirement calls for modifications to the substrate to be introduced to provide optimized sensitivity. This paper will review existing CMOS image sensors, whose size can be as large as a single CMOS wafer, and analyse the technical requirements and specific challenges of large format CMOS image sensors.

  10. [Estimation of spur dike-affected fish habitat area].

    PubMed

    Ray-Shyan, Wu; Yan-Ru, Chen; Yi-Liang, Ge

    2012-04-01

    Based on the HEC-RAS and River 2D modes, and taking 5% change rate of weighted usable area (WUA) as the threshold to define the spur dike- affected area of target fish species Acrossocheilus paradoxus in Fazi River in Taiwan, this paper studied the affected area of the fish habitat by spur dike, and, in combining with the references about the installations of spur dikes in Taiwan in recent 10 years, analyzed the relative importance of related affecting factors such as dike height, dike length (water block rate), average slope gradient of river way, single or double spur dike, and flow discharge. In spite of the length of the dike, the affected area in downstream was farther, and was about 2-6 times as large as that in upstream. The ratio of the affected area in downstream / upstream decreased with increasing slope gradient, but increased with increasing dike length and flow discharge. When the discharge was approximate to 10 years return periods, the ratio of the affected area would be close to a constant of 2. Building double spur dike would produce a better WUA than building single spur dike.

  11. Do large hiatal hernias affect esophageal peristalsis?

    PubMed Central

    Roman, Sabine; Kahrilas, Peter J; Kia, Leila; Luger, Daniel; Soper, Nathaniel; Pandolfino, John E

    2013-01-01

    Background & Aim Large hiatal hernias can be associated with a shortened or tortuous esophagus. We hypothesized that these anatomic changes may alter esophageal pressure topography (EPT) measurements made during high-resolution manometry (HRM). Our aim was to compare EPT measures of esophageal motility in patients with large hiatal hernias to those of patients without hernia. Methods Among 2000 consecutive clinical EPT, we identified 90 patients with large (>5 cm) hiatal hernias on endoscopy and at least 7 evaluable swallows on EPT. Within the same database a control group without hernia was selected. EPT was analyzed for lower esophageal sphincter (LES) pressure, Distal Contractile Integral (DCI), contraction amplitude, Contractile Front Velocity (CFV) and Distal Latency time (DL). Esophageal length was measured on EPT from the distal border of upper esophageal sphincter to the proximal border of the LES. EPT diagnosis was based on the Chicago Classification. Results The manometry catheter was coiled in the hernia and did not traverse the crural diaphragm in 44 patients (49%) with large hernia. Patients with large hernias had lower average LES pressures, lower DCI, slower CFV and shorter DL than patients without hernia. They also exhibited a shorter mean esophageal length. However, the distribution of peristaltic abnormalities was not different in patients with and without large hernia. Conclusions Patients with large hernias had an alteration of EPT measurements as a consequence of the associated shortened esophagus. However, the distribution of peristaltic disorders was unaffected by the presence of hernia. PMID:22508779

  12. Development of large-area glass GEM

    NASA Astrophysics Data System (ADS)

    Mitsuya, Yuki; Fujiwara, Takeshi; Fushie, Takashi; Maekawa, Tatsuyuki; Takahashi, Hiroyuki

    2015-09-01

    We have developed a new gaseous radiation detector, referred to as the Glass GEM (G-GEM). The G-GEM is composed of a photosensitive etching glass (PEG3) substrate from HOYA Corporation, Japan. Since a large-area detector is required for imaging device applications, we newly developed a large-area G-GEM prototype with a sensitive area of 280×280 mm2. In this study, we investigated its basic characteristics and confirmed that it worked properly and had sufficient uniformity across the entire sensitive area. It had high gas gain of up to approximately 7700, along with good energy resolution of 26.2% (FWHM) for a 5.9-keV X-ray with a gas mixture of Ar (90%) and CH4 (10%). The gain variation across the sensitive area was almost within the range of ±10%.

  13. The Large Area Crop Inventory Experiment (LACIE)

    NASA Technical Reports Server (NTRS)

    Macdonald, R. B.

    1976-01-01

    A Large Area Crop Inventory Experiment (LACIE) was undertaken to prove out an economically important application of remote sensing from space. The experiment focused upon determination of wheat acreages in the U.S. Great Plains and upon the development and testing of yield models. The results and conclusions are presented.

  14. Large area space solar cell assemblies

    NASA Technical Reports Server (NTRS)

    Spitzer, M. B.; Nowlan, M. J.

    1982-01-01

    Development of a large area space solar cell assembly is presented. The assembly consists of an ion implanted silicon cell and glass cover. The important attributes of fabrication are (1) use of a back surface field which is compatible with a back surface reflector, and (2) integration of coverglass application and call fabrication.

  15. GLAST Large Area Telescope Multiwavelength Planning

    SciTech Connect

    Reimer, O.; Michelson, P.F.; Cameron, R.A.; Digel, S.W.; Thompson, D.J.; Wood, K.S.

    2007-01-03

    Gamma-ray astrophysics depends in many ways on multiwavelength studies. The Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) Collaboration has started multiwavelength planning well before the scheduled 2007 launch of the observatory. Some of the high-priority multiwavelength needs include: (1) availability of contemporaneous radio and X-ray timing of pulsars; (2) expansion of blazar catalogs, including redshift measurements; (3) improved observations of molecular clouds, especially at high galactic latitudes; (4) simultaneous broad-band blazar monitoring; (5) characterization of gamma-ray transients, including gamma ray bursts; (6) radio, optical, X-ray and TeV counterpart searches for reliable and effective sources identification and characterization. Several of these activities are needed to be in place before launch.

  16. GLAST Large Area Telescope Multiwavelength Planning

    NASA Technical Reports Server (NTRS)

    Reimer, O.; Michelson, P. F.; Cameron, R. A.; Digel, S. W.; Thompson, D. J.; Wood, K. S.

    2007-01-01

    Gamma-ray astrophysics depends in many ways on multiwavelength studies. The Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) Collaboration has started multiwavelength planning well before the scheduled 2007 launch of the observatory. Some of the high-priority multiwavelength needs include: (1) availability of contemporaneous radio and X-ray timing of pulsars; (2) expansion of blazar catalogs, including redshift measurements; (3) improved observations of molecular clouds, especially at high galactic latitudes; (4) simultaneous broad-spectrum blazar monitoring; (5) characterization of gamma-ray transients, including gamma ray bursts; (6) radio, optical, X-ray and TeV counterpart searches for reliable and effective sources identification and characterization. Several of these activities are needed to be in place before launch.

  17. Large-area thin-film modules

    NASA Technical Reports Server (NTRS)

    Tyan, Y. S.; Perez-Albuerne, E. A.

    1985-01-01

    The low cost potential of thin film solar cells can only be fully realized if large area modules can be made economically with good production yields. This paper deals with two of the critical challenges. A scheme is presented which allows the simple, economical realization of the long recognized, preferred module structure of monolithic integration. Another scheme reduces the impact of shorting defects and, as a result, increases the production yields. Analytical results demonstrating the utilization and advantages of such schemes are discussed.

  18. Large-Area Vacuum Ultraviolet Sensors

    NASA Technical Reports Server (NTRS)

    Aslam, Shahid; Franz, David

    2012-01-01

    Pt/(n-doped GaN) Schottky-barrier diodes having active areas as large as 1 cm square have been designed and fabricated as prototypes of photodetectors for the vacuum ultraviolet portion (wavelengths approximately equal 200 nm) of the solar spectrum. In addition to having adequate sensitivity to photons in this wavelength range, these photodetectors are required to be insensitive to visible and infrared components of sunlight and to have relatively low levels of dark current.

  19. Some Pregnant Women Still Travel to Zika-Affected Areas

    MedlinePlus

    ... 160025.html Some Pregnant Women Still Travel to Zika-Affected Areas 41 New York City moms-to- ... women from New York City are traveling to Zika-affected areas and then getting tested when they ...

  20. The Large Area Pulsed Solar Simulator (LAPSS)

    NASA Technical Reports Server (NTRS)

    Mueller, R. L.

    1993-01-01

    A Large Area Pulsed Solar Simulator (LAPSS) has been installed at JPL. It is primarily intended to be used to illuminate and measure the electrical performance of photovoltaic devices. The simulator, originally manufactured by Spectrolab, Sylmar, California, occupies an area measuring about 3 meters wide by 12 meters long. The data acquisition and data processing subsystems have been modernized. Tests on the LAPSS performance resulted in better than +/- 2 percent uniformity of irradiance at the test plane and better than +/- 0.3 percent measurement repeatability after warm-up. Glass absorption filters are used to reduce the level of ultraviolet light emitted from the xenon flash lamps. This provides a close match to standard airmass zero and airmass 1.5 spectral irradiance distributions. The 2 millisecond light pulse prevents heating of the device under test, resulting in more reliable temperature measurements. Overall, excellent electrical performance measurements have been made of many different types and sizes of photovoltaic devices.

  1. Timing Characteristics of Large Area Picosecond Photodetectors

    SciTech Connect

    Adams, Bernhard W.; Elagin, Andrey L.; Frisch, H.; Obaid, Razib; Oberla, E; Vostrikov, Alexander; Wagner, Robert G.; Wang, Jingbo; Wetstein, Matthew J.; Northrop, R

    2015-09-21

    The LAPPD Collaboration was formed to develop ultralast large-area imaging photodetectors based on new methods for fabricating microchannel plates (MCPs). In this paper we characterize the time response using a pulsed, sub picosecond laser. We observe single photoelectron time resolutions of a 20 cm x 20 cm MCP consistently below 70 ps, spatial resolutions of roughly 500 pm, and median gains higher than 10(7). The RMS measured at one particular point on an LAPPD detector is 58 ps, with in of 47 ps. The differential time resolution between the signal reaching the two ends of the delay line anode is measured to be 5.1 ps for large signals, with an asymptotic limit falling below 2 ps as noise-over-signal approaches zero.

  2. Large area position sensitive β-detector

    NASA Astrophysics Data System (ADS)

    Vaintraub, S.; Hass, M.; Edri, H.; Morali, N.; Segal, T.

    2015-03-01

    A new conceptual design of a large area electron detector, which is position and energy sensitive, was developed. This detector is designed for beta decay energies up to 4 MeV, but in principle can be re-designed for higher energies. The detector incorporates one large plastic scintillator and, in general, a limited number of photomultipliers (7 presently). The current setup was designed and constructed after an extensive Geant4 simulation study. By comparison of a single hit light distribution between the various photomultipliers to a pre-measured accurate position-response map, the anticipated position resolution is around 5 mm. The first benchmark experiments have been conducted in order to calibrate and confirm the position resolution of the detector. The new method, results of the first test experiments and comparison to simulations are presented.

  3. Timing characteristics of Large Area Picosecond Photodetectors

    NASA Astrophysics Data System (ADS)

    Adams, B. W.; Elagin, A.; Frisch, H. J.; Obaid, R.; Oberla, E.; Vostrikov, A.; Wagner, R. G.; Wang, J.; Wetstein, M.

    2015-09-01

    The LAPPD Collaboration was formed to develop ultrafast large-area imaging photodetectors based on new methods for fabricating microchannel plates (MCPs). In this paper we characterize the time response using a pulsed, sub-picosecond laser. We observe single-photoelectron time resolutions of a 20 cm × 20 cm MCP consistently below 70 ps, spatial resolutions of roughly 500 μm, and median gains higher than 107. The RMS measured at one particular point on an LAPPD detector is 58 ps, with ± 1σ of 47 ps. The differential time resolution between the signal reaching the two ends of the delay line anode is measured to be 5.1 ps for large signals, with an asymptotic limit falling below 2 ps as noise-over-signal approaches zero.

  4. Large Area X-Ray Spectroscopy Mission

    NASA Technical Reports Server (NTRS)

    Tananbaum, H.

    1997-01-01

    The Large Area X-ray Spectroscopy (LAXS) mission concept study continues to evolve strongly following the merging of the LAXS mission with the Next Generation X-ray Observatory (NGXO, PI: Nick White) into the re-named High Throughput X-ray Spectroscopy (HTXS) Mission. HTXS retains key elements of the LAXS proposal, including the use of multiple satellites for risk-reduction and cost savings. A key achievement of the program has been the recommendation by the Structure and Evolution of the Universe (SEUS) (April 1997) for a new start for the HTXS mission in the 2000-2004 timeframe.

  5. High Efficiency Large Area Polysilicon Solar Cells

    NASA Technical Reports Server (NTRS)

    Johnson, S. M.; Winter, C.

    1985-01-01

    Large area (100 sq cm) polysilicon solar cells having efficiencies of up to 14.1% (100 mW/sq cm, 25 C) were fabricated and a detailed analysis was performed to identify the efficiency loss mechanisms. The 1-5 characteristics of the best cell were dominated by recombination in the quasi-neutral base due to the combination of minority carrier diffusion length and base resistivity. An analysis of the microstructural defects present in the material and their effect on the electrical properties is presented.

  6. Large area cold plasma applicator for decontamination

    NASA Astrophysics Data System (ADS)

    Konesky, G. A.

    2008-04-01

    Cold plasma applicators have been used in the Medical community for several years for uses ranging from hemostasis ("stop bleeding") to tumor removal. An added benefit of this technology is enhanced wound healing by the destruction of infectious microbial agents without damaging healthy tissue. The beam is typically one millimeter to less than a centimeter in diameter. This technology has been adapted and expanded to large area applicators of potentially a square meter or more. Decontamination applications include both biological and chemical agents, and assisting in the removal of radiological agents, with minimal or no damage to the contaminated substrate material. Linear and planar multiemitter array plasma applicator design and operation is discussed.

  7. The Large Area Pulsed Solar Simulator (LAPSS)

    NASA Technical Reports Server (NTRS)

    Mueller, R. L.

    1994-01-01

    The Large Area Pulsed Solar Simulator (LAPSS) has been installed at JPL. It is primarily intended to be used to illuminate and measure the electrical performance of photovoltaic devices. The simulator, originally manufactured by Spectrolab, Sylmar, CA, occupies an area measuring about 3 m wide x 12 m long. The data acquisition and data processing subsystems have been modernized. Tests on the LAPSS performance resulted in better than plus or minus 2 percent uniformity of irradiance at the test plane and better than plus or minus 0.3 percent measurement repeatability after warm-up. Glass absorption filters reduce the ultraviolet light emitted from the xenon flash lamps. This results in a close match to three different standard airmass zero and airmass 1.5 spectral irradiances. The 2-ms light pulse prevents heating of the device under test, resulting in more reliable temperature measurements. Overall, excellent electrical performance measurements have been made of many different types and sizes of photovoltaic devices. Since the original printing of this publication, in 1993, the LAPSS has been operational and new capabilities have been added. This revision includes a new section relating to the installation of a method to measure the I-V curve of a solar cell or array exhibiting a large effective capacitance. Another new section has been added relating to new capabilities for plotting single and multiple I-V curves, and for archiving the I-V data and test parameters. Finally, a section has been added regarding the data acquisition electronics calibration.

  8. Electrohydrodynamically driven large-area liquid ion sources

    DOEpatents

    Pregenzer, Arian L.

    1988-01-01

    A large-area liquid ion source comprises means for generating, over a large area of the surface of a liquid, an electric field of a strength sufficient to induce emission of ions from a large area of said liquid. Large areas in this context are those distinct from emitting areas in unidimensional emitters.

  9. Soil resources area affects herbivore health.

    PubMed

    Garner, James A; Ahmad, H Anwar; Dacus, Chad M

    2011-06-01

    Soil productivity effects nutritive quality of food plants, growth of humans and animals, and reproductive health of domestic animals. Game-range surveys sometimes poorly explained variations in wildlife populations, but classification of survey data by major soil types improved effectiveness. Our study evaluates possible health effects of lower condition and reproductive rates for wild populations of Odocoileus virginianus Zimmerman (white-tailed deer) in some physiographic regions of Mississippi. We analyzed condition and reproductive data for 2400 female deer from the Mississippi Department of Wildlife, Fisheries, and Parks herd health evaluations from 1991-1998. We evaluated age, body mass (Mass), kidney mass, kidney fat mass, number of corpora lutea (CL) and fetuses, as well as fetal ages. Region affected kidney fat index (KFI), which is a body condition index, and numbers of fetuses of adults (P≤0.001). Region affected numbers of CL of adults (P≤0.002). Mass and conception date (CD) were affected (P≤0.001) by region which interacted significantly with age for Mass (P≤0.001) and CD (P<0.04). Soil region appears to be a major factor influencing physical characteristics of female deer.

  10. The CLAS12 large area RICH detector

    SciTech Connect

    M. Contalbrigo, E. Cisbani, P. Rossi

    2011-05-01

    A large area RICH detector is being designed for the CLAS12 spectrometer as part of the 12 GeV upgrade program of the Jefferson Lab Experimental Hall-B. This detector is intended to provide excellent hadron identification from 3 GeV/c up to momenta exceeding 8 GeV/c and to be able to work at the very high design luminosity-up to 1035 cm2 s-1. Detailed feasibility studies are presented for two types of radiators, aerogel and liquid C6F14 freon, in conjunction with a highly segmented light detector in the visible wavelength range. The basic parameters of the RICH are outlined and the resulting performances, as defined by preliminary simulation studies, are reported.

  11. The CLAS12 large area RICH detector

    NASA Astrophysics Data System (ADS)

    Contalbrigo, M.; Cisbani, E.; Rossi, P.

    2011-05-01

    A large area RICH detector is being designed for the CLAS12 spectrometer as part of the 12 GeV upgrade program of the Jefferson Lab Experimental Hall-B. This detector is intended to provide excellent hadron identification from 3 GeV/ c up to momenta exceeding 8 GeV/ c and to be able to work at the very high design luminosity-up to 10 35 cm 2 s -1. Detailed feasibility studies are presented for two types of radiators, aerogel and liquid C 6F 14 freon, in conjunction with a highly segmented light detector in the visible wavelength range. The basic parameters of the RICH are outlined and the resulting performances, as defined by preliminary simulation studies, are reported.

  12. Large Area Lunar Dust Flux Measurement Instrument

    NASA Technical Reports Server (NTRS)

    Corsaro, R.; Giovane, F.; Liou, Jer-Chyi; Burchell, M.; Stansbery, Eugene; Lagakos, N.

    2009-01-01

    The instrument under development is designed to characterize the flux and size distribution of the lunar micrometeoroid and secondary ejecta environment. When deployed on the lunar surface, the data collected will benefit fundamental lunar science as well as enabling more reliable impact risk assessments for human lunar exploration activities. To perform this task, the instrument requirements are demanding. It must have as large a surface area as possible to sample the very sparse population of the larger potentially damage-inducing micrometeorites. It must also have very high sensitivity to enable it to measure the flux of small (<10 micron) micrometeorite and secondary ejecta dust particles. To be delivered to the lunar surface, it must also be very low mass, rugged and stow compactly. The instrument designed to meet these requirements is called FOMIS. It is a large-area thin film under tension (i.e. a drum) with multiple fiber optic displacement (FOD) sensors to monitor displacements of the film. This sensor was chosen since it can measure displacements over a wide dynamic range: 1 cm to sub-Angstrom. A prototype system was successfully demonstrated using the hypervelocity impact test facility at the University of Kent (Canterbury, UK). Based on these results, the prototype system can detect hypervelocity (approx.5 km/s) impacts by particles as small as 2 microns diameter. Additional tests using slow speeds find that it can detect secondary ejecta particles (which do not penetrate the film) with momentums as small as 15 pico-gram 100m/s, or nominally 5 microns diameter at 100 m/s.

  13. Fermi Large Area Telescope Second Source Catalog

    NASA Astrophysics Data System (ADS)

    Nolan, P. L.; Abdo, A. A.; Ackermann, M.; Ajello, M.; Allafort, A.; Antolini, E.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Bechtol, K.; Belfiore, A.; Bellazzini, R.; Berenji, B.; Bignami, G. F.; Blandford, R. D.; Bloom, E. D.; Bonamente, E.; Bonnell, J.; Borgland, A. W.; Bottacini, E.; Bouvier, A.; Brandt, T. J.; Bregeon, J.; Brigida, M.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Campana, R.; Cañadas, B.; Cannon, A.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Ceccanti, M.; Cecchi, C.; Çelik, Ö.; Charles, E.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chipaux, R.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Corbet, R.; Cutini, S.; D'Ammando, F.; Davis, D. S.; de Angelis, A.; DeCesar, M. E.; DeKlotz, M.; De Luca, A.; den Hartog, P. R.; de Palma, F.; Dermer, C. D.; Digel, S. W.; Silva, E. do Couto e.; Drell, P. S.; Drlica-Wagner, A.; Dubois, R.; Dumora, D.; Enoto, T.; Escande, L.; Fabiani, D.; Falletti, L.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Focke, W. B.; Fortin, P.; Frailis, M.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Gehrels, N.; Germani, S.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Gustafsson, M.; Hadasch, D.; Hanabata, Y.; Harding, A. K.; Hayashida, M.; Hays, E.; Hill, A. B.; Horan, D.; Hou, X.; Hughes, R. E.; Iafrate, G.; Itoh, R.; Jóhannesson, G.; Johnson, R. P.; Johnson, T. E.; Johnson, A. S.; Johnson, T. J.; Kamae, T.; Katagiri, H.; Kataoka, J.; Katsuta, J.; Kawai, N.; Kerr, M.; Knödlseder, J.; Kocevski, D.; Kuss, M.; Lande, J.; Landriu, D.; Latronico, L.; Lemoine-Goumard, M.; Lionetto, A. M.; Llena Garde, M.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Marelli, M.; Massaro, E.; Mazziotta, M. N.; McConville, W.; McEnery, J. E.; Mehault, J.; Michelson, P. F.; Minuti, M.; Mitthumsiri, W.; Mizuno, T.; Moiseev, A. A.; Mongelli, M.; Monte, C.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nakamori, T.; Naumann-Godo, M.; Norris, J. P.; Nuss, E.; Nymark, T.; Ohno, M.; Ohsugi, T.; Okumura, A.; Omodei, N.; Orlando, E.; Ormes, J. F.; Ozaki, M.; Paneque, D.; Panetta, J. H.; Parent, D.; Perkins, J. S.; Pesce-Rollins, M.; Pierbattista, M.; Pinchera, M.; Piron, F.; Pivato, G.; Porter, T. A.; Racusin, J. L.; Rainò, S.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Ritz, S.; Rochester, L. S.; Romani, R. W.; Roth, M.; Rousseau, R.; Ryde, F.; Sadrozinski, H. F.-W.; Salvetti, D.; Sanchez, D. A.; Saz Parkinson, P. M.; Sbarra, C.; Scargle, J. D.; Schalk, T. L.; Sgrò, C.; Shaw, M. S.; Shrader, C.; Siskind, E. J.; Smith, D. A.; Spandre, G.; Spinelli, P.; Stephens, T. E.; Strickman, M. S.; Suson, D. J.; Tajima, H.; Takahashi, H.; Takahashi, T.; Tanaka, T.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Tinebra, F.; Tinivella, M.; Torres, D. F.; Tosti, G.; Troja, E.; Uchiyama, Y.; Vandenbroucke, J.; Van Etten, A.; Van Klaveren, B.; Vasileiou, V.; Vianello, G.; Vitale, V.; Waite, A. P.; Wallace, E.; Wang, P.; Werner, M.; Winer, B. L.; Wood, D. L.; Wood, K. S.; Wood, M.; Yang, Z.; Zimmer, S.

    2012-04-01

    We present the second catalog of high-energy γ-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24 month period. The second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in five energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 MeV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely γ-ray-producing source classes. We dedicate this paper to the memory of our colleague Patrick Nolan, who died on 2011 November 6. His career spanned much of the history of high-energy astronomy from space and his work on the Large Area Telescope (LAT) began nearly 20 years ago when it was just a concept. Pat was a central member in the operation of the LAT collaboration and he is greatly missed.

  14. Large-area mapping of biodiversity

    USGS Publications Warehouse

    Scott, J.M.; Jennings, M.D.

    1998-01-01

    The age of discovery, description, and classification of biodiversity is entering a new phase. In responding to the conservation imperative, we can now supplement the essential work of systematics with spatially explicit information on species and assemblages of species. This is possible because of recent conceptual, technical, and organizational progress in generating synoptic views of the earth's surface and a great deal of its biological content, at multiple scales of thematic as well as geographic resolution. The development of extensive spatial data on species distributions and vegetation types provides us with a framework for: (a) assessing what we know and where we know it at meso-scales, and (b) stratifying the biological universe so that higher-resolution surveys can be more efficiently implemented, coveting, for example, geographic adequacy of specimen collections, population abundance, reproductive success, and genetic dynamics. The land areas involved are very large, and the questions, such as resolution, scale, classification, and accuracy, are complex. In this paper, we provide examples from the United States Gap Analysis Program on the advantages and limitations of mapping the occurrence of terrestrial vertebrate species and dominant land-cover types over large areas as joint ventures and in multi-organizational partnerships, and how these cooperative efforts can be designed to implement results from data development and analyses as on-the-ground actions. Clearly, new frameworks for thinking about biogeographic information as well as organizational cooperation are needed if we are to have any hope of documenting the full range of species occurrences and ecological processes in ways meaningful to their management. The Gap Analysis experience provides one model for achieving these new frameworks.

  15. Large area silicon sheet by EFG

    NASA Technical Reports Server (NTRS)

    Kalejs, J. P.

    1982-01-01

    Work carried out on the JPL Flat Plate Solar Array Project, for the purpose of developing a method for silicon ribbon production by Edge-defined Film-fed Growth (EEG) for use as low-cost substrate material in terrestrial solar cell manufacture, is described. A multiple ribbon furnace unit that is designed to operate on a continuous basis for periods of at least one week, with melt replenishment and automatic ribbon width control, and to produce silicon sheet at a rate of one square meter per hour, was constructed. Program milestones set for single ribbon furnace operation to demonstrate basic EEG system capabilities with respect to growth speed, thickness and cell performance were achieved for 10 cm wide ribbon: steady-state growth at 4 cm/min and 200 micron thickness over periods of an hour and longer was made routine, and a small area cell efficiency of 13+% demonstrated. Large area cells of average efficiency of 10 to 11%, with peak values of 11 to 12% were also achieved. The integration of these individual performance levels into multiple ribbon furnace operation was not accomplished.

  16. Large-area Silicon-Film™ manufacturing

    NASA Astrophysics Data System (ADS)

    Ford, D. H.; Barnett, A. M.; Checchi, J. C.; Culik, J. S.; Hall, R. B.; Jackson, E. L.; Kendall, C. L.; Rand, J. A.

    1997-02-01

    The Silicon-Film™ process is on an accelerated path to large-scale manufacturing. A key element in that development is optimizing the specific geometry of both the Silicon-Film™ sheet and the resulting solar cell. That decision has been influenced by cost factors, engineering concerns, and marketing issues. The geometry investigation has focused first on sheet nominally 15 cm wide. This sheet generated solar cells with areas of 240 cm2 and 675 cm2. Most recently a new sheet fabrication machine was constructed that produces Silicon-Film™ with a width in excess of 30 cm. The results of testing have indicated that there is no limit to the width of sheet generated by this process. The new wide material has led to prototype solar cells with areas of 300, 400 and 1800 cm2. Test results are available on some sizes, with all results expected later this year. Significant advances in solar cell processing have been developed in support of fabricating devices of this size including diffusion and application of the anti-reflection coating.

  17. Uniformity studies in large area triple-GEM based detectors

    NASA Astrophysics Data System (ADS)

    Akl, M. Abi; Bouhali, O.; Castaneda, A.; Maghrbi, Y.; Mohamed, T.

    2016-10-01

    Gas Electron Multiplier (GEM) based detectors have been used in many applications since their introduction in 1997. Large areas, e.g. exceeding 30×30 cm2, of GEM detectors are foreseen in future experiments which puts stringent requirements on the uniformity of response across the detection area. We investigate the effect of small variations of several parameters that could affect the uniformity. Parameters such as the anode pitch, the gas gap, the size and the shape of the holes are investigated. Simulation results are presented and compared to previous experimental data.

  18. Timing Conception Might Help Reduce Zika Risk in Affected Areas

    MedlinePlus

    ... fullstory_160127.html Timing Conception Might Help Reduce Zika Risk in Affected Areas Researcher suggests attempting pregnancy ... THURSDAY, July 28, 2016 (HealthDay News) -- Women in Zika-affected countries might reduce their risk of infection ...

  19. Targeted flight opportunities with large area collectors

    NASA Technical Reports Server (NTRS)

    Mackinnon, I. D. R.

    1986-01-01

    A major factor in the stratospheric collection process is the relative density of particles at the collection altitude. With current aircraft-borne collector plate geometries, one potential extraterrestrial particle of about 10 micron diameter is collected approximately every hour. However, a new design for the collector plate, termed the Large Area Collector (LAC), allows a factor of 10 improvement in collection efficiency over current conventional geometry. The implementation of LAC design on future stratospheric collection flights will provide many opportunities for additional data on both terrestrial and extraterrestrial phenomena. With the improvement in collection efficiency, LAC's may provide a suitable number of potential extraterrestrial particles in one short flight of between 4 and 8 hours duration. Alternatively, total collection periods of approximately 40 hours enhance the probability that rare particles can be retrieved from the stratosphere. This latter approach is of great value for the cosmochemist who may wish to perform sophisticated analyses on interplanetary dust greater than a picogram. The former approach, involving short duration flights, may also provide invaluable data on the source of many extraterrestrial particles. The time dependence of particle entry to the collection altitude is an important parameter which may be correlated with specific global events (e.g., meteoroid streams) provided the collection time is known to an accuracy of 2 hours.

  20. Large area atmospheric-pressure plasma jet

    DOEpatents

    Selwyn, Gary S.; Henins, Ivars; Babayan, Steve E.; Hicks, Robert F.

    2001-01-01

    Large area atmospheric-pressure plasma jet. A plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two planar, parallel electrodes are employed to generate a plasma in the volume therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly spacing the rf-powered electrode. Because of the atmospheric pressure operation, there is a negligible density of ions surviving for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike the situation for low-pressure plasma sources and conventional plasma processing methods.

  1. FERMI LARGE AREA TELESCOPE SECOND SOURCE CATALOG

    SciTech Connect

    Nolan, P. L.; Ajello, M.; Allafort, A.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Abdo, A. A.; Ackermann, M.; Antolini, E.; Bonamente, E.; Atwood, W. B.; Belfiore, A.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Ballet, J.; Bastieri, D.; Bignami, G. F. E-mail: Gino.Tosti@pg.infn.it E-mail: tburnett@u.washington.edu; and others

    2012-04-01

    We present the second catalog of high-energy {gamma}-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24 month period. The second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in five energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 MeV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely {gamma}-ray-producing source classes.

  2. Large area silicon sheet by EFG

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Progress was made in improving ribbon flatness and reducing stress, and in raising cell performance for 10 cm wide ribbon grown in single cartridge EFG furnaces. Optimization of growth conditions resulted in improved ribbon thickness uniformity at a thickness of 200 micron, grown at 4 cm/minute, and growth at this target speed is routinely achieved over periods of the order of one hour or more. With the improved ribbon flatness, fabrication of large area (50 cm2) cells is now possible, and 10 to 11% efficiencies were demonstrated on ribbon grown at 3.5 to 4 cm/minute. Factors limiting performance of the existing multiple ribbon furnace were identified, and growth system improvements implemented to help raise throughput rates and the time percentage of simultaneous three-ribbon growth. However, it is evident that major redesign of this furnace would be needed to overcome shortfalls in its ability to achieve the Technical Features Demonstration goals of 1980. It was decided to start construction of a new multiple ribbon furnace and to incorporate the desired improvements into its design. The construction of this furnace is completed.

  3. Fermi Large Area Telescope Second Source Catalog

    NASA Technical Reports Server (NTRS)

    Nolan, P. L.; Abdo, A. A.; Ackermann, M.; Ajello, M; Allafort, A.; Antolini, E; Bonnell, J.; Cannon, A.; Celik O.; Corbet, R.; Davis, D. S.; DeCesar, M. E.; Ferrara, E. C.; Gehrels, N.; Harding, A. K.; Hays, E.; Johnson, T. E.; McConville, W.; McEnery, J. E; Perkins, J. S.; Racusin, J. L; Scargle, J. D.; Stephens, T. E.; Thompson, D. J.; Troja, E.

    2012-01-01

    We present the second catalog of high-energy gamma-ray sources detected by the Large Area Telescope (LAT), the primary science instrument on the Fermi Gamma-ray Space Telescope (Fermi), derived from data taken during the first 24 months of the science phase of the mission, which began on 2008 August 4. Source detection is based on the average flux over the 24-month period. The Second Fermi-LAT catalog (2FGL) includes source location regions, defined in terms of elliptical fits to the 95% confidence regions and spectral fits in terms of power-law, exponentially cutoff power-law, or log-normal forms. Also included are flux measurements in 5 energy bands and light curves on monthly intervals for each source. Twelve sources in the catalog are modeled as spatially extended. We provide a detailed comparison of the results from this catalog with those from the first Fermi-LAT catalog (1FGL). Although the diffuse Galactic and isotropic models used in the 2FGL analysis are improved compared to the 1FGL catalog, we attach caution flags to 162 of the sources to indicate possible confusion with residual imperfections in the diffuse model. The 2FGL catalog contains 1873 sources detected and characterized in the 100 11eV to 100 GeV range of which we consider 127 as being firmly identified and 1171 as being reliably associated with counterparts of known or likely gamma-ray-producing source classes.

  4. Fermi Large Area Telescope Third Source Catalog

    NASA Astrophysics Data System (ADS)

    Acero, F.; Ackermann, M.; Ajello, M.; Albert, A.; Atwood, W. B.; Axelsson, M.; Baldini, L.; Ballet, J.; Barbiellini, G.; Bastieri, D.; Belfiore, A.; Bellazzini, R.; Bissaldi, E.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Bonino, R.; Bottacini, E.; Bregeon, J.; Britto, R. J.; Bruel, P.; Buehler, R.; Burnett, T. H.; Buson, S.; Caliandro, G. A.; Cameron, R. A.; Caputo, R.; Caragiulo, M.; Caraveo, P. A.; Casandjian, J. M.; Cavazzuti, E.; Charles, E.; Chaves, R. C. G.; Chekhtman, A.; Cheung, C. C.; Chiang, J.; Chiaro, G.; Ciprini, S.; Claus, R.; Cohen-Tanugi, J.; Cominsky, L. R.; Conrad, J.; Cutini, S.; D'Ammando, F.; de Angelis, A.; DeKlotz, M.; de Palma, F.; Desiante, R.; Digel, S. W.; Di Venere, L.; Drell, P. S.; Dubois, R.; Dumora, D.; Favuzzi, C.; Fegan, S. J.; Ferrara, E. C.; Finke, J.; Franckowiak, A.; Fukazawa, Y.; Funk, S.; Fusco, P.; Gargano, F.; Gasparrini, D.; Giebels, B.; Giglietto, N.; Giommi, P.; Giordano, F.; Giroletti, M.; Glanzman, T.; Godfrey, G.; Grenier, I. A.; Grondin, M.-H.; Grove, J. E.; Guillemot, L.; Guiriec, S.; Hadasch, D.; Harding, A. K.; Hays, E.; Hewitt, J. W.; Hill, A. B.; Horan, D.; Iafrate, G.; Jogler, T.; Jóhannesson, G.; Johnson, R. P.; Johnson, A. S.; Johnson, T. J.; Johnson, W. N.; Kamae, T.; Kataoka, J.; Katsuta, J.; Kuss, M.; La Mura, G.; Landriu, D.; Larsson, S.; Latronico, L.; Lemoine-Goumard, M.; Li, J.; Li, L.; Longo, F.; Loparco, F.; Lott, B.; Lovellette, M. N.; Lubrano, P.; Madejski, G. M.; Massaro, F.; Mayer, M.; Mazziotta, M. N.; McEnery, J. E.; Michelson, P. F.; Mirabal, N.; Mizuno, T.; Moiseev, A. A.; Mongelli, M.; Monzani, M. E.; Morselli, A.; Moskalenko, I. V.; Murgia, S.; Nuss, E.; Ohno, M.; Ohsugi, T.; Omodei, N.; Orienti, M.; Orlando, E.; Ormes, J. F.; Paneque, D.; Panetta, J. H.; Perkins, J. S.; Pesce-Rollins, M.; Piron, F.; Pivato, G.; Porter, T. A.; Racusin, J. L.; Rando, R.; Razzano, M.; Razzaque, S.; Reimer, A.; Reimer, O.; Reposeur, T.; Rochester, L. S.; Romani, R. W.; Salvetti, D.; Sánchez-Conde, M.; Saz Parkinson, P. M.; Schulz, A.; Siskind, E. J.; Smith, D. A.; Spada, F.; Spandre, G.; Spinelli, P.; Stephens, T. E.; Strong, A. W.; Suson, D. J.; Takahashi, H.; Takahashi, T.; Tanaka, Y.; Thayer, J. G.; Thayer, J. B.; Thompson, D. J.; Tibaldo, L.; Tibolla, O.; Torres, D. F.; Torresi, E.; Tosti, G.; Troja, E.; Van Klaveren, B.; Vianello, G.; Winer, B. L.; Wood, K. S.; Wood, M.; Zimmer, S.; Fermi-LAT Collaboration

    2015-06-01

    We present the third Fermi Large Area Telescope (LAT) source catalog (3FGL) of sources in the 100 MeV-300 GeV range. Based on the first 4 yr of science data from the Fermi Gamma-ray Space Telescope mission, it is the deepest yet in this energy range. Relative to the Second Fermi LAT catalog, the 3FGL catalog incorporates twice as much data, as well as a number of analysis improvements, including improved calibrations at the event reconstruction level, an updated model for Galactic diffuse γ-ray emission, a refined procedure for source detection, and improved methods for associating LAT sources with potential counterparts at other wavelengths. The 3FGL catalog includes 3033 sources above 4σ significance, with source location regions, spectral properties, and monthly light curves for each. Of these, 78 are flagged as potentially being due to imperfections in the model for Galactic diffuse emission. Twenty-five sources are modeled explicitly as spatially extended, and overall 238 sources are considered as identified based on angular extent or correlated variability (periodic or otherwise) observed at other wavelengths. For 1010 sources we have not found plausible counterparts at other wavelengths. More than 1100 of the identified or associated sources are active galaxies of the blazar class; several other classes of non-blazar active galaxies are also represented in the 3FGL. Pulsars represent the largest Galactic source class. From source counts of Galactic sources we estimate that the contribution of unresolved sources to the Galactic diffuse emission is ˜3% at 1 GeV.

  5. Large Area X-ray Spectroscopy Mission

    NASA Technical Reports Server (NTRS)

    Tananbaum, Harvey

    1996-01-01

    The Large Area X-ray Spectroscopy (LAXS) mission study concept has evolved strongly over the last year culminating in the merging of LAXS with the Goddard Space Flight Center (GSFC) proposal for a similar mission, the Next Generation X-ray Observatory (NGXO, PI: Nick White). The resulting merger, re-named the High Throughput X-rays Spectroscopy (HTXS) Mission has also expanded by the inclusion of another SAO proposed new mission concept proposal, the Hard X-Ray Telescope (PI: Paul Gorenstein). The resultant multi-instrument mission retains much of heritage from the LAXS proposal, including the use of multiple satellites for robustness. These mergers resulted from a series of contacts between various team members, via e-mail, telecons, and in-person meetings. The impetus for the mergers was the fundamental similarity between the missions, and the recognition that all three proposal teams had significant contributions to make in the effort to define the next stage in the X-ray exploration of the universe. We have enclosed four items that represent some of the work that has occurred during the first year of the study: first, a presentation at the Leicester meeting, second a presentation that was made to Dan Goldin following the merging of LAXS and NGXO, third a copy of the first announcement for the Workshop, and finally the interim report that was prepared by the HTXS study team towards the end of the first year. This last document provides the foundation for the HTXS Technology Roadmap that is being generated. The HTXS roadmap will define the near-term goals that the merged mission must achieve over the next few years. A web site has been developed and populated that contains much of the material that has been generated over the past year.

  6. Polyurethane Masks Large Areas in Electroplating

    NASA Technical Reports Server (NTRS)

    Beasley, J. L.

    1985-01-01

    Polyurethane foam provides effective mask in electroplating of copper or nickel. Thin layer of Turco maskant painted on area to be masked: Layer ensures polyurethane foam removed easily after served its purpose. Component A, isocyanate, and component B, polyol, mixed together and brushed or sprayed on mask area. Mixture reacts, yielding polyurethane foam. Foam prevents deposition of nickel or copper on covered area. New method saves time, increases productivity and uses less material than older procedures.

  7. ISABELLE. Volume 3. Experimental areas, large detectors

    SciTech Connect

    Not Available

    1981-01-01

    This section presents the papers which resulted from work in the Experimental Areas portion of the Workshop. The immediate task of the group was to address three topics. The topics were dictated by the present state of ISABELLE experimental areas construction, the possibility of a phased ISABELLE and trends in physics and detectors.

  8. Gamma-Ray Large Area Space Telescope- GLAST Mission Overview

    NASA Technical Reports Server (NTRS)

    Moiseev, Alexander A.

    2007-01-01

    This viewgraph presentation reviews the Gamma-ray Large Area Space Telescope (GLAST), and the instrumentation that will be on the spacecraft: Large Area Telescope (LAT) and GLAST Burst Monitor (GBM). The presentation revierws in detail the LAT instrument.

  9. Large area flexible solar array design for Space Shuttle application

    NASA Technical Reports Server (NTRS)

    Souza, C. J.

    1980-01-01

    A large area flexible solar array has been designed for Shuttle power augmentation. The solar array utilizes large area, low cost, weldable solar cells. The paper addresses how the unique requirements of this system are implemented into the design. Economic and reliability issues relating to the optimization of a large area, foldable solar array concomitant to the Shuttle/Orbiter system are reviewed.

  10. Towards large area THz electromagnetic metamaterials

    NASA Astrophysics Data System (ADS)

    Moser, H. O.; Bahou, M.; Chen, A.; Heussler, S. P.; Jian, L. K.; Kalaiselvi, S. M. P.; Liu, G.; Maniam, S. M.; bin Mahmood, Shahrain; Gu, P. D.; Wen, L.; Kong, J. A.; Chen, H. S.; Cheng, X. X.; Wu, B. I.; Casse, B. D. F.; Rockstuhl, C.; Lederer, F.

    2008-08-01

    Up to date, electromagnetic metamaterials (EM3) have been mostly fabricated by primary pattern generation via electron beam or laser writer. Such an approach is time-consuming and may have limitations of the area filled with structures. Especially, electron beam written structures are typically confined to areas of a few 100×100 μm2. However, for meaningful technological applications, larger quantities of good quality materials are needed. Lithography, in particular X-ray deep lithography, is well suited to accomplish this task. Singapore Synchrotron Light Source (SSLS) has been applying its LIGA process that includes primary pattern generation via electron beam or laser writer, X-ray deep lithography and electroplating to the micro/nano-manufacturing of high-aspect ratio structures to produce a variety of EM3 structures. Starting with Pendry's split ring resonators, we have pursued structure designs suitable for planar lithography since 2002 covering a range of resonance frequencies from 1 to 216 THz. More recently, string-like structures have also been included. Latest progress made in the manufacturing and characterization of quasi 3D metamaterials having either split ring or string structures over areas of about ~1 cm2 extension will be described.

  11. Large Area Silicon Sheet by EFG

    NASA Technical Reports Server (NTRS)

    Wald, F. V.

    1979-01-01

    Progress made in the development of EFG ribbon growth is discussed. Specific areas covered include: (1) demonstration of multiple growth for ribbons 5 cm wide in runs of 12 and 20 hours duration; (2) a single cartridge crystal growth station was built expanding observational capacity by virtue of an anamorphic optical-video system which allows close observation of the meniscus over 7.5 cm wide, as well as video taping of the ribbon growth process; (3) growth station no.1 achieved reproducible and reliable growth of 7.5 cm wide ribbon at speeds up to 4 cm/min; (4) introduction of the 'mini cold shoe'; (5) increases in cell efficiency due to interface shaping using the 'displaced die' concept; and (6) clarification of the role of gaseous impurities in cartridge furnaces and stabilization of their destabilizing influence on growth.

  12. Large-area silicon sheet task

    NASA Astrophysics Data System (ADS)

    Morrison, A. D.

    1982-04-01

    A set of computer models was used to define a growth system configuration that was then built and used to grow web with lower thermally generated stress. Aspects of research in the edge-defined film-fed growth (EFG) method of making Si ribbon are reported. A technique was developed to determine base resistivity and carrier lifetime in semicrystalline wafers. Automated growth of 150 kg of 15 cm-dia ingot material per crucible is reviewed. Scanning transmisson electron microscopy (STEM) and microprobe investigations of processed EFG ribbon are reported. The chemical composition of the large precipitates was studied. The structural arrangement and the electrical activity of distentions or close to the central twin plane in processed material were studied. The electrical and structural properties of grain boundaries in silicon are discussed. Temperature-dependence measurements of zero-bias conductance, a photoconductivity technique, and deep-level transient spectroscopy (DLTS) were developed. A grooving and staining technique, secondary ion mass spectroscopy, and EBIC measurements in scanning electron microscopy were used to study enhanced diffusion of phosphorus at grain boundaries in polycrystaline silicon. The fundamental mechanisms of abrasion and wear and the deformation of Si by a diamond in various fluid environments are described. The efficiency of solar cells made from EFG ribbon and Semix Inc. material is reported.

  13. Large-area silicon sheet task

    NASA Technical Reports Server (NTRS)

    Morrison, A. D.

    1982-01-01

    A set of computer models was used to define a growth system configuration that was then built and used to grow web with lower thermally generated stress. Aspects of research in the edge-defined film-fed growth (EFG) method of making Si ribbon are reported. A technique was developed to determine base resistivity and carrier lifetime in semicrystalline wafers. Automated growth of 150 kg of 15 cm-dia ingot material per crucible is reviewed. Scanning transmisson electron microscopy (STEM) and microprobe investigations of processed EFG ribbon are reported. The chemical composition of the large precipitates was studied. The structural arrangement and the electrical activity of distentions or close to the central twin plane in processed material were studied. The electrical and structural properties of grain boundaries in silicon are discussed. Temperature-dependence measurements of zero-bias conductance, a photoconductivity technique, and deep-level transient spectroscopy (DLTS) were developed. A grooving and staining technique, secondary ion mass spectroscopy, and EBIC measurements in scanning electron microscopy were used to study enhanced diffusion of phosphorus at grain boundaries in polycrystaline silicon. The fundamental mechanisms of abrasion and wear and the deformation of Si by a diamond in various fluid environments are described. The efficiency of solar cells made from EFG ribbon and Semix Inc. material is reported.

  14. Hydrological and sediment connectivity in areas affected by wildfires.

    NASA Astrophysics Data System (ADS)

    Martinez-Murillo, Juan F.; Ruiz-Sinoga, José D.

    2016-04-01

    This study deals with the hydrological and sediment connectivity (HSC) process in burned areas, from detailed to wider spatial scales: -First of all, it is presented a brief review and analysis of meta-data, already published. -Secondly, some examples of HSC are shown from areas affected by wildfires in South of Spain. -Finally, it is an attempt of applying some indexes of hydrological connectivity to those areas. The study try to shed light on this complex process of connectivity from the hydrological and sedimentary point of view, a kew issue to improve the management of burned areas.

  15. Large-scale mapping of mutations affecting zebrafish development

    PubMed Central

    Geisler, Robert; Rauch, Gerd-Jörg; Geiger-Rudolph, Silke; Albrecht, Andrea; van Bebber, Frauke; Berger, Andrea; Busch-Nentwich, Elisabeth; Dahm, Ralf; Dekens, Marcus PS; Dooley, Christopher; Elli, Alexandra F; Gehring, Ines; Geiger, Horst; Geisler, Maria; Glaser, Stefanie; Holley, Scott; Huber, Matthias; Kerr, Andy; Kirn, Anette; Knirsch, Martina; Konantz, Martina; Küchler, Axel M; Maderspacher, Florian; Neuhauss, Stephan C; Nicolson, Teresa; Ober, Elke A; Praeg, Elke; Ray, Russell; Rentzsch, Brit; Rick, Jens M; Rief, Eva; Schauerte, Heike E; Schepp, Carsten P; Schönberger, Ulrike; Schonthaler, Helia B; Seiler, Christoph; Sidi, Samuel; Söllner, Christian; Wehner, Anja; Weiler, Christian; Nüsslein-Volhard, Christiane

    2007-01-01

    Background Large-scale mutagenesis screens in the zebrafish employing the mutagen ENU have isolated several hundred mutant loci that represent putative developmental control genes. In order to realize the potential of such screens, systematic genetic mapping of the mutations is necessary. Here we report on a large-scale effort to map the mutations generated in mutagenesis screening at the Max Planck Institute for Developmental Biology by genome scanning with microsatellite markers. Results We have selected a set of microsatellite markers and developed methods and scoring criteria suitable for efficient, high-throughput genome scanning. We have used these methods to successfully obtain a rough map position for 319 mutant loci from the Tübingen I mutagenesis screen and subsequent screening of the mutant collection. For 277 of these the corresponding gene is not yet identified. Mapping was successful for 80 % of the tested loci. By comparing 21 mutation and gene positions of cloned mutations we have validated the correctness of our linkage group assignments and estimated the standard error of our map positions to be approximately 6 cM. Conclusion By obtaining rough map positions for over 300 zebrafish loci with developmental phenotypes, we have generated a dataset that will be useful not only for cloning of the affected genes, but also to suggest allelism of mutations with similar phenotypes that will be identified in future screens. Furthermore this work validates the usefulness of our methodology for rapid, systematic and inexpensive microsatellite mapping of zebrafish mutations. PMID:17212827

  16. Factors affecting occupational therapy job site selection in underserviced areas.

    PubMed

    Polatajko, H; Quintyn, M

    1986-06-01

    Rural and isolated areas such as those found in northern Ontario are often underserved with respect to occupational therapy. These areas present special problems for those involved in recruitment and planning recruitment programs. While it is generally recognized that practice in these areas can be both stimulating and rewarding, little is known about what factors might influence occupational therapists to choose these areas for job sites. It was the purpose of this study to investigate factors affecting job site selection and retention among occupational therapists in northern Ontario. Seven potential factors were explored: family proximity, place of origin, lifestyle, fieldwork placements, job opportunities and recruitment tours. These became the basis for the development of a questionnaire which was sent to all facilities employing occupational therapists in northern Ontario. The responses of twenty eight therapists (70%) indicated that the factors affecting job site selection were, in descending order: lifestyle, job opportunity, partner's employment and family proximity. The results also indicated that the factors influencing recruitment and retention differ. Based on the findings, recruitment efforts should focus on emphasizing the attractive features of the north and perhaps on people with family in the north. Retention incentives should include money for equipment, space, continuing education, travel, better salaries, links to educational resources and fieldwork placements.

  17. INTERIOR VIEW, PREPARING LARGE MOLD IN BOX FLOOR AREA. WORKERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    INTERIOR VIEW, PREPARING LARGE MOLD IN BOX FLOOR AREA. WORKERS JUST FILLED THE FLASK WITH SAND FROM A HIGH VELOCITY MECHANICAL SAND THRUSTER. - Stockham Pipe & Fittings Company, Ductile Iron Foundry, 4000 Tenth Avenue North, Birmingham, Jefferson County, AL

  18. Satellite image collection modeling for large area hazard emergency response

    NASA Astrophysics Data System (ADS)

    Liu, Shufan; Hodgson, Michael E.

    2016-08-01

    Timely collection of critical hazard information is the key to intelligent and effective hazard emergency response decisions. Satellite remote sensing imagery provides an effective way to collect critical information. Natural hazards, however, often have large impact areas - larger than a single satellite scene. Additionally, the hazard impact area may be discontinuous, particularly in flooding or tornado hazard events. In this paper, a spatial optimization model is proposed to solve the large area satellite image acquisition planning problem in the context of hazard emergency response. In the model, a large hazard impact area is represented as multiple polygons and image collection priorities for different portion of impact area are addressed. The optimization problem is solved with an exact algorithm. Application results demonstrate that the proposed method can address the satellite image acquisition planning problem. A spatial decision support system supporting the optimization model was developed. Several examples of image acquisition problems are used to demonstrate the complexity of the problem and derive optimized solutions.

  19. Factors affecting areas contributing recharge to wells in shallow aquifers

    USGS Publications Warehouse

    Reilly, Thomas E.; Pollock, David W.

    1993-01-01

    The source of water to wells is ultimately the location where the water flowing to a well enters the boundary surface of the ground-water system. In ground-water systems that receive most of their water from areal recharge, the location of the water entering the ground-water system is at the water table. The area contributing recharge to a discharging well is the surface area that defines the location of the water entering the ground-water system at the water table that flows to the well and is eventually discharged from the well. The calculation of areas contributing recharge to wells is complex because flow paths in ground-water systems change in response to development, and the aquifer material in ground-water systems is heterogeneous and is hidden from direct observation . Hypothetical experiments were undertaken to show the complexities in the delineation of areas contributing recharge to wells. Four different 'cases' are examined to demonstrate the effect of different conceptualized aquifer frameworks on deterministically calculated areas contributing recharge. The main conclusion drawn from the experiments is that, in order to understand the cause and effect relations that affect the quality of water derived from wells, the importance and nature of the variability in the ground-waterflow system must be considered and accounted for in any efforts to 'protect' the water supply.

  20. Role of community health nurse in earthquake affected areas.

    PubMed

    Gulzar, Saleema Aziz; Faheem, Zahid Ali; Somani, Rozina Karim

    2012-10-01

    The role of Community Health Nurses (CHNs) outside the traditional hospital setting is meant to provide and promote the health care needs of the community. Such nurses can play a substantial role in the community setting including emergencies like disasters. This became evident after the earthquake of October 8, 2005 in Pakistan. The objective was to address the issues, faced by primary healthcare providers working in earthquake-affected areas focusing on participatory approach. The experience of the interventions done by CHN by a guided frame work (assessment, planning, implementation and evaluation components) is described. Issues identified by CHN included: lack of training of health care providers, lack of collaboration, communication between the medical and management staff due to poor infrastructure of the healthcare facilities. The interventions were carried out, utilizing existing resources. Efforts were directed to build capacity of health care providers at grass root level to fill in gaps of health care delivery system for sustainable change. Overall, working in the earthquake affected areas is challenging. Health leadership should foresee role of CHN in emergencies where quality healthcare interventions are essential.

  1. Plasma and Ion Sources in Large Area Coatings: A Review

    SciTech Connect

    Anders, Andre

    2005-02-28

    Efficient deposition of high-quality coatings often requires controlled application of excited or ionized particles. These particles are either condensing (film-forming) or assisting by providing energy and momentum to the film growth process, resulting in densification, sputtering/etching, modification of stress, roughness, texture, etc. In this review, the technical means are surveyed enabling large area application of ions and plasmas, with ion energies ranging from a few eV to a few keV. Both semiconductortype large area (single wafer or batch processing with {approx} 1000 cm{sup 2}) and in-line web and glass-coating-type large area (> 10{sup 7} m{sup 2} annually) are considered. Characteristics and differences between plasma and ion sources are explained. The latter include gridded and gridless sources. Many examples are given, including sources based on DC, RF, and microwave discharges, some with special geometries like hollow cathodes and E x B configurations.

  2. Progress on large-area polarization grating fabrication

    NASA Astrophysics Data System (ADS)

    Miskiewicz, Matthew N.; Kim, Jihwan; Li, Yanming; Komanduri, Ravi K.; Escuti, Michael J.

    2012-06-01

    Over the last several years, we have pioneered liquid crystal polarization gratings (PGs), in both switchable and polymer versions. We have also introduced their use in many applications, including mechanical/non-mechanical laser beam steering and polarization imaging/sensing. Until now, conventional holographic congurations were used to create PGs where the diameter of the active area was limited to 1-2 inches. In this paper, we discuss a new holography setup to fabricate large area PGs using spherical waves as the diverging coherent beams. Various design parameters of this setup are examined for impact on the quality of the recorded PG profile. Using this setup, we demonstrate a large area polymer PG with approximately 66 inch square area, and present detailed characterization.

  3. Large-area metallic photonic lattices for military applications.

    SciTech Connect

    Luk, Ting Shan

    2007-11-01

    In this project we developed photonic crystal modeling capability and fabrication technology that is scaleable to large area. An intelligent optimization code was developed to find the optimal structure for the desired spectral response. In terms of fabrication, an exhaustive survey of fabrication techniques that would meet the large area requirement was reduced to Deep X-ray Lithography (DXRL) and nano-imprint. Using DXRL, we fabricated a gold logpile photonic crystal in the <100> plane. For the nano-imprint technique, we fabricated a cubic array of gold squares. These two examples also represent two classes of metallic photonic crystal topologies, the connected network and cermet arrangement.

  4. Large-area cryocooling for far-infrared telescopes

    NASA Astrophysics Data System (ADS)

    Hoang, Triem T.; O'Connell, Tamara A.; Ku, Jentung; Butler, C. D.; Swanson, Theodore D.

    2003-10-01

    Requirements for cryocooling of large-area heat sources begin to appear in studies of future space missions. Examples are the cooling of (i) the entire structure/mirror of large Far Infrared space telescopes to 4-40K and (ii) cryogenic thermal bus to maintain High Temperature Superconductor electronics to below 75K. The cryocooling system must provide robust/reliable operation and not cause significant vibration to the optical components. But perhaps the most challenging aspect of the system design is the removal of waste heat over a very large area. A cryogenic Loop Heat Pipe (C-LHP)/ cryocooler cooling system was developed with the ultimate goal of meeting the aforementioned requirements. In the proposed cooling concept, the C-LHP collected waste heat from a large-area heat source and then transported it to the cryocooler coldfinger for rejection. A proof-of-concept C-LHP test loop was constructed and performance tested in a vacuum chamber to demonstrate the feasibility of the proposed C-LHP to distribute the cryocooler cooling power over a large area. The test loop was designed to operate with any cryogenic working fluid such as Oxygen/Nitrogen (60-120K), Neon (28-40K), Hydrogen (18-30K), and Helium (2.5-4.5K). Preliminary test results indicated that the test loop had a cooling capacity of 4.2W in the 30-40K temperature range with Neon as the working fluid.

  5. Semiconductor-based, large-area, flexible, electronic devices

    DOEpatents

    Goyal, Amit

    2011-03-15

    Novel articles and methods to fabricate the same resulting in flexible, large-area, triaxially textured, single-crystal or single-crystal-like, semiconductor-based, electronic devices are disclosed. Potential applications of resulting articles are in areas of photovoltaic devices, flat-panel displays, thermophotovoltaic devices, ferroelectric devices, light emitting diode devices, computer hard disc drive devices, magnetoresistance based devices, photoluminescence based devices, non-volatile memory devices, dielectric devices, thermoelectric devices and quantum dot laser devices.

  6. Modeling a Dry Etch Process for Large-Area Devices

    SciTech Connect

    Buss, R.J.; Hebner, G.A.; Ruby, D.S.; Yang, P.

    1999-07-28

    There has been considerable interest in developing dry processes which can effectively replace wet processing in the manufacture of large area photovoltaic devices. Environmental and health issues are a driver for this activity because wet processes generally increase worker exposure to toxic and hazardous chemicals and generate large volumes of liquid hazardous waste. Our work has been directed toward improving the performance of screen-printed solar cells while using plasma processing to reduce hazardous chemical usage.

  7. Identifying Corridors among Large Protected Areas in the United States

    PubMed Central

    Belote, R. Travis; Dietz, Matthew S.; McRae, Brad H.; Theobald, David M.; McClure, Meredith L.; Irwin, G. Hugh; McKinley, Peter S.; Gage, Josh A.; Aplet, Gregory H.

    2016-01-01

    Conservation scientists emphasize the importance of maintaining a connected network of protected areas to prevent ecosystems and populations from becoming isolated, reduce the risk of extinction, and ultimately sustain biodiversity. Keeping protected areas connected in a network is increasingly recognized as a conservation priority in the current era of rapid climate change. Models that identify suitable linkages between core areas have been used to prioritize potentially important corridors for maintaining functional connectivity. Here, we identify the most “natural” (i.e., least human-modified) corridors between large protected areas in the contiguous Unites States. We aggregated results from multiple connectivity models to develop a composite map of corridors reflecting agreement of models run under different assumptions about how human modification of land may influence connectivity. To identify which land units are most important for sustaining structural connectivity, we used the composite map of corridors to evaluate connectivity priorities in two ways: (1) among land units outside of our pool of large core protected areas and (2) among units administratively protected as Inventoried Roadless (IRAs) or Wilderness Study Areas (WSAs). Corridor values varied substantially among classes of “unprotected” non-core land units, and land units of high connectivity value and priority represent diverse ownerships and existing levels of protections. We provide a ranking of IRAs and WSAs that should be prioritized for additional protection to maintain minimal human modification. Our results provide a coarse-scale assessment of connectivity priorities for maintaining a connected network of protected areas. PMID:27104683

  8. Identifying Corridors among Large Protected Areas in the United States.

    PubMed

    Belote, R Travis; Dietz, Matthew S; McRae, Brad H; Theobald, David M; McClure, Meredith L; Irwin, G Hugh; McKinley, Peter S; Gage, Josh A; Aplet, Gregory H

    2016-01-01

    Conservation scientists emphasize the importance of maintaining a connected network of protected areas to prevent ecosystems and populations from becoming isolated, reduce the risk of extinction, and ultimately sustain biodiversity. Keeping protected areas connected in a network is increasingly recognized as a conservation priority in the current era of rapid climate change. Models that identify suitable linkages between core areas have been used to prioritize potentially important corridors for maintaining functional connectivity. Here, we identify the most "natural" (i.e., least human-modified) corridors between large protected areas in the contiguous Unites States. We aggregated results from multiple connectivity models to develop a composite map of corridors reflecting agreement of models run under different assumptions about how human modification of land may influence connectivity. To identify which land units are most important for sustaining structural connectivity, we used the composite map of corridors to evaluate connectivity priorities in two ways: (1) among land units outside of our pool of large core protected areas and (2) among units administratively protected as Inventoried Roadless (IRAs) or Wilderness Study Areas (WSAs). Corridor values varied substantially among classes of "unprotected" non-core land units, and land units of high connectivity value and priority represent diverse ownerships and existing levels of protections. We provide a ranking of IRAs and WSAs that should be prioritized for additional protection to maintain minimal human modification. Our results provide a coarse-scale assessment of connectivity priorities for maintaining a connected network of protected areas. PMID:27104683

  9. LEAP - A LargE Area Burst Polarimeter for the ISS

    NASA Astrophysics Data System (ADS)

    McConnell, M. L.; LEAP Collaboration

    2016-10-01

    The LargE Area burst Polarimeter (LEAP) is a mission concept for a 50-500 keV Compton scatter polarimeter instrument that would be deployed on the ISS. It will be proposed as an astrophysics Mission of Opportunity (MoO) in late 2016.

  10. MONITORING OF LARGE INSTABLE AREAS: system reliability and new tools.

    NASA Astrophysics Data System (ADS)

    Leandro, G.; Mucciarelli, M.; Pellicani, R.; Spilotro, G.

    2009-04-01

    The monitoring of unstable or potentially unstable areas is a necessary operation every time you can not remove the conditions of risk and apply to mitigation measures. In Italian Apennine regions there are many urban or extra-urban areas affected by instability, for which it is impracticable to remove hazard conditions, because of size and cost problems. The technological evolution exportable to the field of land instability monitoring is particularly lively and allows the use of warning systems unthinkable just few years ago. However, the monitoring of unstable or potentially unstable areas requires a very great knowledge of the specific problems, without which the reliability of the system may be dangerously overestimated. The movement may arise, indeed, in areas not covered by instrumentation, or covered with vegetation that prevents the acquisition of both reflected signals in the multi-beam laser techniques and radar signals. Environmental conditions (wind, concentrated sources of light, temperature changes, presence of animals) may also invalidate the accuracy of the measures, by introducing modulations or disturbance at a level well above the threshold of alarm signal, leading consequently to raise the values of the warning threshold. The Authors have gained long experience with the observation and monitoring of some large landslides in the Southern Apennine (Aliano, Buoninventre, Calciano, Carlantino, etc.) and unstable areas also at regional scale. One of the most important experiences is about the case of landslides of extensive areas, where unstable and stables zones coexist along transverse and longitudinal axis. In many of these cases you need the accurate control of the movement at selected points to evaluate the trend of displacement velocity, which can be achieved by means of a single-beam laser. The control of these movements, however, does not provide information on stress pattern into the stable areas. Among the sensitive precursors, acoustic

  11. Large area, low cost solar cell development and production readiness

    NASA Technical Reports Server (NTRS)

    Michaels, D.

    1982-01-01

    A process sequence for a large area ( or = 25 sq. cm) silicon solar cell was investigated. Generic cell choice was guided by the expected electron fluence, by the packing factors of various cell envelope designs onto each panel to provide needed voltage as well as current, by the weight constraints on the system, and by the cost goals of the contract.

  12. Large Area Crop Inventory Experiment (LACIE). Phase 1: Evaluation report

    NASA Technical Reports Server (NTRS)

    1976-01-01

    It appears that the Large Area Crop Inventory Experiment over the Great Plains, can with a reasonable expectation, be a satisfactory component of a 90/90 production estimator. The area estimator produced more accurate area estimates for the total winter wheat region than for the mixed spring and winter wheat region of the northern Great Plains. The accuracy does appear to degrade somewhat in regions of marginal agriculture where there are small fields and abundant confusion crops. However, it would appear that these regions tend also to be marginal with respect to wheat production and thus increased area estimation errors do not greatly influence the overall production estimation accuracy in the United States. The loss of segments resulting from cloud cover appears to be a random phenomenon that introduces no significant bias into the estimates. This loss does increase the variance of the estimates.

  13. Spatially explicit shallow landslide susceptibility mapping over large areas

    USGS Publications Warehouse

    Bellugi, Dino; Dietrich, William E.; Stock, Jonathan D.; McKean, Jim; Kazian, Brian; Hargrove, Paul

    2011-01-01

    Recent advances in downscaling climate model precipitation predictions now yield spatially explicit patterns of rainfall that could be used to estimate shallow landslide susceptibility over large areas. In California, the United States Geological Survey is exploring community emergency response to the possible effects of a very large simulated storm event and to do so it has generated downscaled precipitation maps for the storm. To predict the corresponding pattern of shallow landslide susceptibility across the state, we have used the model Shalstab (a coupled steady state runoff and infinite slope stability model) which susceptibility spatially explicit estimates of relative potential instability. Such slope stability models that include the effects of subsurface runoff on potentially destabilizing pore pressure evolution require water routing and hence the definition of upslope drainage area to each potential cell. To calculate drainage area efficiently over a large area we developed a parallel framework to scale-up Shalstab and specifically introduce a new efficient parallel drainage area algorithm which produces seamless results. The single seamless shallow landslide susceptibility map for all of California was accomplished in a short run time, and indicates that much larger areas can be efficiently modelled. As landslide maps generally over predict the extent of instability for any given storm. Local empirical data on the fraction of predicted unstable cells that failed for observed rainfall intensity can be used to specify the likely extent of hazard for a given storm. This suggests that campaigns to collect local precipitation data and detailed shallow landslide location maps after major storms could be used to calibrate models and improve their use in hazard assessment for individual storms.

  14. Management of fire affected areas. Beyond the environmental question

    NASA Astrophysics Data System (ADS)

    Pereira, Paulo

    2016-04-01

    Fire is considered a natural element of the ecosystems. With exception of the polar areas, fire visited with more or less frequency all the earth biomes, determining the ecosystems characteristics, to the point that several species are fire-dependent to survive and are very resilient to their impact. Fire was a fundamental element for human evolution, which allowed us to cook, manipulation of metals, hunt, protect from predators and clear fields for agriculture. In some extension, we are only humans because of fire. In the last millennium fire was used to shape the landscape as we know today. One good example of this is the Mediterranean environment, a landscape where the ecology is not understood without the presence of fire. Until the end of the first half of the last century, fire was used frequently by farmers to landscape management. However, due to rural abandonment, change of life styles, disconnection with rural environment and lack of understanding of fire role in the ecosystems. The perception of fire changed and nowadays is understood by the population as a threat to the ecosystems, rather than a tool that helped to manage the landscape and help us in our evolution. This change of vision promoted the idea that fire has negative impacts in the ecosystems and should be banned from the nature. Something that is impossible. All these perceptions facilitated the implementation of fire-suppression policies, which today are recognized by science as one of the causes of the occurrence of frequent high-severity wildfires, with important impacts on the ecosystems, economy and society. However, most of the ecosystems can regenerate sooner or later, depending of the fire severity and the ecosystem affected. Thus, fire is not an ecological, but social and economic problem, due to lives loss and the temporary destruction of ecosystems, which local communities depend on. In this context, when we are managing fire affected areas, it goes much beyond environmental

  15. Large area, surface discharge pumped, vacuum ultraviolet light source

    DOEpatents

    Sze, Robert C.; Quigley, Gerard P.

    1996-01-01

    Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source. A contamination-free VUV light source having a 225 cm.sup.2 emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm.sup.2 at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing.

  16. Large area, surface discharge pumped, vacuum ultraviolet light source

    DOEpatents

    Sze, R.C.; Quigley, G.P.

    1996-12-17

    Large area, surface discharge pumped, vacuum ultraviolet (VUV) light source is disclosed. A contamination-free VUV light source having a 225 cm{sup 2} emission area in the 240-340 nm region of the electromagnetic spectrum with an average output power in this band of about 2 J/cm{sup 2} at a wall-plug efficiency of approximately 5% is described. Only ceramics and metal parts are employed in this surface discharge source. Because of the contamination-free, high photon energy and flux, and short pulse characteristics of the source, it is suitable for semiconductor and flat panel display material processing. 3 figs.

  17. Large-area nanoscale patterning: chemistry meets fabrication.

    PubMed

    Henzie, Joel; Barton, Jeremy E; Stender, Christopher L; Odom, Teri W

    2006-04-01

    This Account describes a new paradigm for large-area nanoscale patterning that combines bottom-up and top-down approaches, merging chemistry with fabrication. This hybrid strategy uses simple nanofabrication techniques to control the alignment, size, shape, and periodicity of nanopatterns and chemical methods to control their materials properties and crystallinity. These tools are highly flexible and can create surface-patterned nanostructures with unusual properties and free-standing nanostructures that are multifunctional and monodisperse. The unprecedented scientific and technological opportunities enabled by nanoscale patterning over wafer-sized areas are discussed.

  18. Optimized metallization patterns for large-area silicon solar cells

    NASA Technical Reports Server (NTRS)

    Matzen, W. T.; Chiang, S. Y.; Carbajal, B. G.

    1976-01-01

    Design criteria is presented for optimizing the front-surface metallization pattern of large-area silicon solar cells. A computer program calculates the spacing of metal fingers which minimizes resistive and shadowing losses. Finger spacing and efficiency for the optimum design are presented as a function of finger width and cell size. It is shown that quantitative evaluation of metallization pattern options can be made without cell fabrication.

  19. Uniform large-area thermionic cathode for SCALPEL

    NASA Astrophysics Data System (ADS)

    Katsap, Victor; Sewell, Peter B.; Waskiewicz, Warren K.; Zhu, Wei

    1999-11-01

    An electron beam lithography tool, which employs the SCALPEL technique, requires an extremely uniform beam to illuminate the scattering Mask, with the cathode operating in the temperature limited mode. It has been previously shown that LaB6 cathodes are not stable in this mode of operation. We have explored the possibility of implementing refined Tantalum-based emitters in the SCALPEL source cathode, and have developed large-area flat cathodes featuring suitably high emission uniformity under temperature limited operation.

  20. Chemical vapor deposition of silicon carbide for large area mirrors

    NASA Astrophysics Data System (ADS)

    Gentilman, R. L.; Maguire, E. A.

    1982-05-01

    CVD-SiC has been identified as the leading mirror material for high energy synchrotron radiation because of its high K/alpha ratio and its ability to be super-polished to less than or equal to 10 A rms roughness. Technology already exists for depositing SiC over large areas (approximately 70 cm x 20 cm). The CVD process, substrate selection, and mirror design considerations are discussed.

  1. Characterization of Large Area APDs for the EXO-200 Detector

    SciTech Connect

    Neilson, R.; LePort, F.; Pocar, A.; Kumar, K.; Odian, A.; Prescott, C.Y.; Tenev, V.; Ackerman, N.; Akimov, D.; Auger, M.; Benitez-Medina, C.; Breidenbach, M.; Burenkov, A.; Conley, R.; Cook, S.; deVoe, R.; Dolinski, M.J.; Fairbank, W., Jr.; Farine, J.; Fierlinger, P.; Flatt, B.; /Stanford U., Phys. Dept. /Bern U., LHEP /Stanford U., Phys. Dept. /Maryland U. /Colorado State U. /Laurentian U. /Carleton U. /SLAC /Maryland U. /Moscow, ITEP /Alabama U. /SLAC /Colorado State U. /Stanford U., Phys. Dept. /Alabama U. /Stanford U., Phys. Dept. /Alabama U. /SLAC /Carleton U. /SLAC /Maryland U. /Moscow, ITEP /Carleton U. /Stanford U., Phys. Dept. /Bern U., LHEP /SLAC /Laurentian U. /SLAC /Maryland U.

    2011-12-02

    EXO-200 uses 468 large area avalanche photodiodes (LAAPDs) for detection of scintillation light in an ultra-low-background liquid xenon (LXe) detector. We describe initial measurements of dark noise, gain and response to xenon scintillation light of LAAPDs at temperatures from room temperature to 169 K - the temperature of liquid xenon. We also describe the individual characterization of more than 800 LAAPDs for selective installation in the EXO-200 detector.

  2. High Energy Astrophysics with the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Hays, Elizabeth

    2009-01-01

    This slide presentation reviews some of the findings of the Large Area Telescope (LAT) aboard the Fermi Observatory. It includes information about the LAT, and the Gamma-Ray Burst Monitor (GBM), detection of the quiet sun and the moon in gamma rays, Pulsars observed by the observatory, Globular Star Clusters, Active Galactic Nucleus, and Gamma-Ray Bursts, with specific information about GRB 080916C.

  3. Gravure printing of graphene for large-area flexible electronics.

    PubMed

    Secor, Ethan B; Lim, Sooman; Zhang, Heng; Frisbie, C Daniel; Francis, Lorraine F; Hersam, Mark C

    2014-07-01

    Gravure printing of graphene is demonstrated for the rapid production of conductive patterns on flexible substrates. Development of suitable inks and printing parameters enables the fabrication of patterns with a resolution down to 30 μm. A mild annealing step yields conductive lines with high reliability and uniformity, providing an efficient method for the integration of graphene into large-area printed and flexible electronics.

  4. Fiber-optic large area average temperature sensor

    SciTech Connect

    Looney, L.L.; Forman, P.R.

    1994-05-01

    In many instances the desired temperature measurement is only the spatial average temperature over a large area; eg. ground truth calibration for satellite imaging system, or average temperature of a farm field. By making an accurate measurement of the optical length of a long fiber-optic cable, we can determine the absolute temperature averaged over its length and hence the temperature of the material in contact with it.

  5. Factors affecting the performance of large-aperture microphone arrays.

    PubMed

    Silverman, Harvey F; Patterson, William R; Sachar, Joshua

    2002-05-01

    Large arrays of microphones have been proposed and studied as a possible means of acquiring data in offices, conference rooms, and auditoria without requiring close-talking microphones. When such an array essentially surrounds all possible sources, it is said to have a large aperture. Large-aperture arrays have attractive properties of spatial resolution and signal-to-noise enhancement. This paper presents a careful comparison of theoretical and measured performance for an array of 256 microphones using simple delay-and-sum beamforming. This is the largest currently functional, all digital-signal-processing array that we know of. The array is wall-mounted in the moderately adverse environment of a general-purpose laboratory (8 m x 8 m x 3 m). The room has a T60 reverberation time of 550 ms. Reverberation effects in this room severely impact the array's performance. However, the width of the main lobe remains comparable to that of a simplified prediction. Broadband spatial resolution shows a single central peak with 10 dB gain about 0.4 m in diameter at the -3 dB level. Away from that peak, the response is approximately flat over most of the room. Optimal weighting for signal-to-noise enhancement degrades the spatial resolution minimally. Experimentally, we verify that signal-to-noise gain is less than proportional to the square root of the number of microphones probably due to the partial correlation of the noise between channels, to variation of signal intensity with polar angle about the source, and to imperfect correlation of the signal over the array caused by reverberations. We show measurements of the relative importance of each effect in our environment. PMID:12051434

  6. Factors affecting the performance of large-aperture microphone arrays.

    PubMed

    Silverman, Harvey F; Patterson, William R; Sachar, Joshua

    2002-05-01

    Large arrays of microphones have been proposed and studied as a possible means of acquiring data in offices, conference rooms, and auditoria without requiring close-talking microphones. When such an array essentially surrounds all possible sources, it is said to have a large aperture. Large-aperture arrays have attractive properties of spatial resolution and signal-to-noise enhancement. This paper presents a careful comparison of theoretical and measured performance for an array of 256 microphones using simple delay-and-sum beamforming. This is the largest currently functional, all digital-signal-processing array that we know of. The array is wall-mounted in the moderately adverse environment of a general-purpose laboratory (8 m x 8 m x 3 m). The room has a T60 reverberation time of 550 ms. Reverberation effects in this room severely impact the array's performance. However, the width of the main lobe remains comparable to that of a simplified prediction. Broadband spatial resolution shows a single central peak with 10 dB gain about 0.4 m in diameter at the -3 dB level. Away from that peak, the response is approximately flat over most of the room. Optimal weighting for signal-to-noise enhancement degrades the spatial resolution minimally. Experimentally, we verify that signal-to-noise gain is less than proportional to the square root of the number of microphones probably due to the partial correlation of the noise between channels, to variation of signal intensity with polar angle about the source, and to imperfect correlation of the signal over the array caused by reverberations. We show measurements of the relative importance of each effect in our environment.

  7. Factors affecting the performance of large-aperture microphone arrays

    NASA Astrophysics Data System (ADS)

    Silverman, Harvey F.; Patterson, William R.; Sachar, Joshua

    2002-05-01

    Large arrays of microphones have been proposed and studied as a possible means of acquiring data in offices, conference rooms, and auditoria without requiring close-talking microphones. When such an array essentially surrounds all possible sources, it is said to have a large aperture. Large-aperture arrays have attractive properties of spatial resolution and signal-to-noise enhancement. This paper presents a careful comparison of theoretical and measured performance for an array of 256 microphones using simple delay-and-sum beamforming. This is the largest currently functional, all digital-signal-processing array that we know of. The array is wall-mounted in the moderately adverse environment of a general-purpose laboratory (8 m×8 m×3 m). The room has a T60 reverberation time of 550 ms. Reverberation effects in this room severely impact the array's performance. However, the width of the main lobe remains comparable to that of a simplified prediction. Broadband spatial resolution shows a single central peak with 10 dB gain about 0.4 m in diameter at the -3 dB level. Away from that peak, the response is approximately flat over most of the room. Optimal weighting for signal-to-noise enhancement degrades the spatial resolution minimally. Experimentally, we verify that signal-to-noise gain is less than proportional to the square root of the number of microphones probably due to the partial correlation of the noise between channels, to variation of signal intensity with polar angle about the source, and to imperfect correlation of the signal over the array caused by reverberations. We show measurements of the relative importance of each effect in our environment.

  8. Advanced Large Area Plastic Scintillator Project (ALPS): Final Report

    SciTech Connect

    Jordan, David V.; Reeder, Paul L.; Todd, Lindsay C.; Warren, Glen A.; McCormick, Kathleen R.; Stephens, Daniel L.; Geelhood, Bruce D.; Alzheimer, James M.; Crowell, Shannon L.; Sliger, William A.

    2008-02-05

    The advanced Large-Area Plastic Scintillator (ALPS) Project at Pacific Northwest National Laboratory investigated possible technological avenues for substantially advancing the state-of-the-art in gamma-ray detection via large-area plastic scintillators. The three predominant themes of these investigations comprised the following: * Maximizing light collection efficiency from a single large-area sheet of plastic scintillator, and optimizing hardware event trigger definition to retain detection efficiency while exploiting the power of coincidence to suppress single-PMT "dark current" background; * Utilizing anti-Compton vetoing and supplementary spectral information from a co-located secondary, or "Back" detector, to both (1) minimize Compton background in the low-energy portion of the "Front" scintillator's pulse-height spectrum, and (2) sharpen the statistical accuracy of the front detector's low-energy response prediction as impelmented in suitable energy-windowing algorithms; and * Investigating alternative materials to enhance the intrinsic gamma-ray detection efficiency of plastic-based sensors.

  9. How large-scale subsidence affects stratocumulus transitions

    NASA Astrophysics Data System (ADS)

    van der Dussen, J. J.; de Roode, S. R.; Siebesma, A. P.

    2016-01-01

    Some climate modeling results suggest that the Hadley circulation might weaken in a future climate, causing a subsequent reduction in the large-scale subsidence velocity in the subtropics. In this study we analyze the cloud liquid water path (LWP) budget from large-eddy simulation (LES) results of three idealized stratocumulus transition cases, each with a different subsidence rate. As shown in previous studies a reduced subsidence is found to lead to a deeper stratocumulus-topped boundary layer, an enhanced cloud-top entrainment rate and a delay in the transition of stratocumulus clouds into shallow cumulus clouds during its equatorwards advection by the prevailing trade winds. The effect of a reduction of the subsidence rate can be summarized as follows. The initial deepening of the stratocumulus layer is partly counteracted by an enhanced absorption of solar radiation. After some hours the deepening of the boundary layer is accelerated by an enhancement of the entrainment rate. Because this is accompanied by a change in the cloud-base turbulent fluxes of moisture and heat, the net change in the LWP due to changes in the turbulent flux profiles is negligibly small.

  10. Large area radiation source for water and wastewater treatment

    NASA Astrophysics Data System (ADS)

    Mueller, Michael T.; Lee, Seungwoo; Kloba, Anthony; Hellmer, Ronald; Kumar, Nalin; Eaton, Mark; Rambo, Charlotte; Pillai, Suresh

    2011-06-01

    There is a strong desire for processes that improve the safety of water supplies and that minimize disinfection byproducts. Stellarray is developing mercury-free next-generation x-ray and UV-C radiation sources in flat-panel and pipe form factors for water and wastewater treatment applications. These new radiation sources are designed to sterilize sludge and effluent, and to enable new treatment approaches to emerging environmental concerns such as the accumulation of estrogenic compounds in water. Our UV-C source, based on cathodoluminescent technology, differs significantly from traditional disinfection approaches using mercury arc lamps or UV LEDs. Our sources accelerate electrons across a vacuum gap, converting their energy into UV-C when striking a phosphor, or x-rays when striking a metallic anode target. Stellarray's large area radiation sources for wastewater treatment allow matching of the radiation source area to the sterilization target area for maximum coverage and improved efficiency.

  11. Large areas elemental mapping by ion beam analysis techniques

    NASA Astrophysics Data System (ADS)

    Silva, T. F.; Rodrigues, C. L.; Curado, J. F.; Allegro, P.; Moro, M. V.; Campos, P. H. O. V.; Santos, S. B.; Kajiya, E. A. M.; Rizzutto, M. A.; Added, N.; Tabacniks, M. H.

    2015-07-01

    The external beam line of the Laboratory for Material Analysis with Ion Beams (LAMFI) is a versatile setup for multi-technique analysis. X-ray detectors for Particle Induced X-rays Emission (PIXE) measurements, a Gamma-ray detector for Particle Induced Gamma- ray Emission (PIGE), and a particle detector for scattering analysis, such as Rutherford Backscattering Spectrometry (RBS), were already installed. In this work, we present some results, using a large (60-cm range) XYZ computer controlled sample positioning system, completely developed and build in our laboratory. The XYZ stage was installed at the external beam line and its high spacial resolution (better than 5 μm over the full range) enables positioning the sample with high accuracy and high reproducibility. The combination of a sub-millimeter beam with the large range XYZ robotic stage is being used to produce elemental maps of large areas in samples like paintings, ceramics, stones, fossils, and all sort of samples. Due to its particular characteristics, this is a unique device in the sense of multi-technique analysis of large areas. With the continuous development of the external beam line at LAMFI, coupled to the robotic XYZ stage, it is becoming a robust and reliable option for regular analysis of trace elements (Z > 5) competing with the traditional in-vacuum ion-beam-analysis with the advantage of automatic rastering.

  12. Characterization and Calibration of Large Area Resistive Strip Micromegas Detectors

    NASA Astrophysics Data System (ADS)

    Lösel, Philipp; ATLAS Muon Collaboration

    2016-07-01

    Resistive strip Micromegas detectors have been tested extensively as small detectors of about 10×10 cm2 in size and they work reliably at high rates of 100 kHz/cm2 and above. Tracking resolution well below 100 μm has been observed for 100 GeV muons and pions. Micromegas detectors are meanwhile proposed as large area muon precision trackers of 2-3 m2 in size. To investigate possible differences between small and large detectors, a 1 m2 detector with 2048 resistive strips at a pitch of 450 μm was studied in the LMU Cosmic Ray Measurement Facility (CRMF) using two 4×2.2 m2 large Monitored Drift Tube (MDT) chambers for cosmic muon reference tracking. A segmentation of the resistive strip anode plane in 57.6 mm×93 mm large areas has been realized by the readout of 128 strips with one APV25 chip each and by eleven 93 mm broad trigger scintillators placed along the readout strips. This allows for mapping of homogeneity in pulse height and efficiency, determination of signal propagation along the 1 m long anode strips and calibration of the position of the anode strips.

  13. SPLASH: A Southern Parkes Large Area Survey in Hydroxyl

    NASA Astrophysics Data System (ADS)

    Dawson, Joanne; Caswell, James; Gomez, Jose F.; Mcclure-Griffiths, Naomi; Lo, Nadia; Jones, Paul; Dickey, John; Cunningham, Maria; Green, James; Carretti, Ettore; Ellingsen, Simon; Walsh, Andrew; Purcell, Cormac; Breen, Shari; Hennebelle, Patrick; Imai, Hiroshi; Lowe, Vicki; Gibson, Steven; Brown, Courtney; Krishnan, Vasaant

    2014-04-01

    The OH 18 cm lines are powerful and versatile probes of diffuse molecular gas, that trace a largely unstudied component of the Galactic ISM. SPLASH (the Southern Parkes Large Area Survey in Hydroxyl) is a large, unbiased and fully-sampled survey of OH emission, absorption and masers in the Galactic Plane that will achieve sensitivities an order of magnitude better than previous work. The survey is answering critical questions on the global distribution of diffuse OH, the degree to which it traces ‘hidden’ material caught between the regimes probed by traditional tracers of the neutral ISM, and its role as a probe of molecular cloud formation. As a blind survey for all four ground-state transitions, SPLASH is also detecting many new OH masers, facilitating a broad range of astrophysical studies. This proposal requests 250 hours to complete Phase 1 of the SPLASH project, which is mapping 152 square degrees in the inner Galactic Plane, including the Galactic Centre.

  14. Large area flexible SERS active substrates using engineered nanostructures

    NASA Astrophysics Data System (ADS)

    Chung, Aram J.; Huh, Yun Suk; Erickson, David

    2011-07-01

    Surface enhanced Raman scattering (SERS) is an analytical sensing method that provides label-free detection, molecularly specific information, and extremely high sensitivity. The Raman enhancement that makes this method attractive is mainly attributed to the local amplification of the incident electromagnetic field that occurs when a surface plasmon mode is excited at a metallic nanostructure. Here, we present a simple, cost effective method for creating flexible, large area SERS-active substrates using a new technique we call shadow mask assisted evaporation (SMAE). The advantage of large, flexible SERS substrates such as these is they have more area for multiplexing and can be incorporated into irregular surfaces such as clothing. We demonstrate the formation of four different types of nanostructure arrays (pillar, nib, ellipsoidal cylinder, and triangular tip) by controlling the evaporation angle, substrate rotation, and deposition rate of metals onto anodized alumina nanoporous membranes as large as 27 mm. In addition, we present experimental results showing how a hybrid structure comprising of gold nanospheres embedded in a silver nano-pillar structure can be used to obtain a 50× SERS enhancement over the raw nanoparticles themselves.Surface enhanced Raman scattering (SERS) is an analytical sensing method that provides label-free detection, molecularly specific information, and extremely high sensitivity. The Raman enhancement that makes this method attractive is mainly attributed to the local amplification of the incident electromagnetic field that occurs when a surface plasmon mode is excited at a metallic nanostructure. Here, we present a simple, cost effective method for creating flexible, large area SERS-active substrates using a new technique we call shadow mask assisted evaporation (SMAE). The advantage of large, flexible SERS substrates such as these is they have more area for multiplexing and can be incorporated into irregular surfaces such as

  15. Factors Affecting the Occurrence of Large Solar Energetic Particle Events

    NASA Astrophysics Data System (ADS)

    Gopalswamy, N.; Yashiro, S.; Akiyama, S.; Xie, H.; Makela, P. A.; Thakur, N.

    2014-12-01

    In order to understand the paucity of high-energy solar energetic particle (SEP) events in solar cycle 24, we examined all major eruptions (soft X-ray flare size ≥M5.0) on the front side of the Sun during the period from December 1, 2008 to January 31, 2014. There were 59 such eruptions that were associated with CMEs. When a flux rope was fitted to the white-light CMEs observed by SOHO and STEREO it was found that the CME sources were on the disk only for 55 eruptions. There were 16 large SEP events (proton intensity ≥10 pfu in the >10 MeV channel) detected by GOES and 4 by STEREO-B in association with these eruptions. When the CMEs were grouped according to their speeds (<1500 km/s and ≥ 1500 km/s) it was found that only three of the <1500 km/s CMEs (or 11%) were associated with large SEP events compared to 17 or (61%) of the ≥ 1500 km/s CMEs. This result confirms the importance of CME speed for SEP association. In fact there were ten other large SEP events with flare size

  16. Priority areas for large mammal conservation in Equatorial Guinea.

    PubMed

    Murai, Mizuki; Ruffler, Heidi; Berlemont, Antoine; Campbell, Genevieve; Esono, Fidel; Agbor, Anthony; Mbomio, Domingo; Ebana, Agustín; Nze, Antonio; Kühl, Hjalmar S

    2013-01-01

    Hunting is one of the main driving forces behind large mammal density distribution in many regions of the world. In tropical Africa, urban demand for bushmeat has been shown to dominate over subsistence hunting and its impact often overrides spatial-ecological species characteristics. To effectively protect remaining mammal populations the main factors that influence their distribution need to be integrated into conservation area prioritisation and management plans. This information has been lacking for Río Muni, Equatorial Guinea, as prior studies have been outdated or have not systematically covered the continental region of the country. In this study we evaluated: 1) the relative importance of local vs. commercial hunting; 2) wildlife density of protected vs. non-protected areas; and 3) the importance of ecological factors vs. human influence in driving mammal density distribution in Río Muni. We adopted a systematic countrywide line transect approach with particular focus on apes and elephants, but also including other mammal species. For analysis of field data we used generalised linear models with a set of predictor variables representing ecological conditions, anthropogenic pressure and protected areas. We estimate that there are currently 884 (437-1,789) elephants and 11,097 (8,719-13,592) chimpanzees and gorillas remaining in Río Muni. The results indicate strong hunting pressures on both local and commercial levels, with roads demonstrating a negative impact on elephants and overall mammal body mass. Protected areas played no role in determining any of the mammal species distributions and significant human hunting signs were found inside these protected areas, illustrating the lack of environmental law enforcement throughout the country. Río Muni is currently under-represented in conservation efforts in Western Equatorial Africa, and we recommend a focus on cross-boundary conservation, in particular in the Monte Alén-Monts de Cristal and Río Campo

  17. Application issues for large-area electrochromic windows incommercial buildings

    SciTech Connect

    Lee, Eleanor S.; DiBartolomeo, D.L.

    2000-05-01

    Projections of performance from small-area devices to large-area windows and enterprise marketing have created high expectations for electrochromic glazings. As a result, this paper seeks to precipitate an objective dialog between material scientists and building-application scientists to determine whether actual large-area electrochromic devices will result in significant performance benefits and what material improvements are needed, if any, to make electrochromics more practical for commercial building applications. Few in-situ tests have been conducted with large-area electrochromic windows applied in buildings. This study presents monitored results from a full-scale field test of large-area electrochromic windows to illustrate how this technology will perform in commercial buildings. The visible transmittance (Tv) of the installed electrochromic ranged from 0.11 to 0.38. The data are limited to the winter period for a south-east-facing window. The effect of actual device performance on lighting energy use, direct sun control, discomfort glare, and interior illumination is discussed. No mechanical system loads were monitored. These data demonstrate the use of electrochromics in a moderate climate and focus on the most restrictive visual task: computer use in offices. Through this small demonstration, we were able to determine that electrochromic windows can indeed provide unmitigated transparent views and a level of dynamic illumination control never before seen in architectural glazing materials. Daily lighting energy use was 6-24 percent less compared to the 11 percent-glazing, with improved interior brightness levels. Daily lighting energy use was 3 percent less to 13 percent more compared to the 38 percent-glazing, with improved window brightness control. The electrochromic window may not be able to fulfill both energy-efficiency and visual comfort objectives when low winter direct sun is present, particularly for computer tasks using cathode-ray tube (CRT

  18. Large area flexible SERS active substrates using engineered nanostructures.

    PubMed

    Chung, Aram J; Huh, Yun Suk; Erickson, David

    2011-07-01

    Surface enhanced Raman scattering (SERS) is an analytical sensing method that provides label-free detection, molecularly specific information, and extremely high sensitivity. The Raman enhancement that makes this method attractive is mainly attributed to the local amplification of the incident electromagnetic field that occurs when a surface plasmon mode is excited at a metallic nanostructure. Here, we present a simple, cost effective method for creating flexible, large area SERS-active substrates using a new technique we call shadow mask assisted evaporation (SMAE). The advantage of large, flexible SERS substrates such as these is they have more area for multiplexing and can be incorporated into irregular surfaces such as clothing. We demonstrate the formation of four different types of nanostructure arrays (pillar, nib, ellipsoidal cylinder, and triangular tip) by controlling the evaporation angle, substrate rotation, and deposition rate of metals onto anodized alumina nanoporous membranes as large as 27 mm. In addition, we present experimental results showing how a hybrid structure comprising of gold nanospheres embedded in a silver nano-pillar structure can be used to obtain a 50× SERS enhancement over the raw nanoparticles themselves.

  19. Electronic hybridization of large-area stacked graphene films.

    PubMed

    Robinson, Jeremy T; Schmucker, Scott W; Diaconescu, C Bogdan; Long, James P; Culbertson, James C; Ohta, Taisuke; Friedman, Adam L; Beechem, Thomas E

    2013-01-22

    Direct, tunable coupling between individually assembled graphene layers is a next step toward designer two-dimensional (2D) crystal systems, with relevance for fundamental studies and technological applications. Here we describe the fabrication and characterization of large-area (>cm(2)), coupled bilayer graphene on SiO(2)/Si substrates. Stacking two graphene films leads to direct electronic interactions between layers, where the resulting film properties are determined by the local twist angle. Polycrystalline bilayer films have a "stained-glass window" appearance explained by the emergence of a narrow absorption band in the visible spectrum that depends on twist angle. Direct measurement of layer orientation via electron diffraction, together with Raman and optical spectroscopy, confirms the persistence of clean interfaces over large areas. Finally, we demonstrate that interlayer coupling can be reversibly turned off through chemical modification, enabling optical-based chemical detection schemes. Together, these results suggest that 2D crystals can be individually assembled to form electronically coupled systems suitable for large-scale applications.

  20. Dark Matter Searches with the Fermi Large Area Telescope

    SciTech Connect

    Meurer, Christine

    2008-12-24

    The Fermi Gamma-Ray Space Telescope, successfully launched on June 11th, 2008, is the next generation satellite experiment for high-energy gamma-ray astronomy. The main instrument, the Fermi Large Area Telescope (LAT), with a wide field of view (>2 sr), a large effective area (>8000 cm{sup 2} at 1 GeV), sub-arcminute source localization, a large energy range (20 MeV-300 GeV) and a good energy resolution (close to 8% at 1 GeV), has excellent potential to either discover or to constrain a Dark Matter signal. The Fermi LAT team pursues complementary searches for signatures of particle Dark Matter in different search regions such as the galactic center, galactic satellites and subhalos, the milky way halo, extragalactic regions as well as the search for spectral lines. In these proceedings we examine the potential of the LAT to detect gamma-rays coming from Weakly Interacting Massive Particle annihilations in these regions with special focus on the galactic center region.

  1. A large-area gamma-ray imaging telescope system

    NASA Technical Reports Server (NTRS)

    Koch, D. G.

    1983-01-01

    The concept definition of using the External Tank (ET) of the Space Shuttle as the basis for constructing a large area gamma ray imaging telescope in space is detailed. The telescope will be used to locate and study cosmic sources of gamma rays of energy greater than 100 MeV. Both the telescope properties and the means whereby an ET is used for this purpose are described. A parallel is drawn between those systems that would be common to both a Space Station and this ET application. In addition, those systems necessary for support of the telescope can form the basis for using the ET as part of the Space Station. The major conclusions of this concept definition are that the ET is ideal for making into a gamma ray telescope, and that this telescope will provide a substantial increase in collecting area.

  2. Large Area Crop Inventory Experiment (LACIE). Phase 2 evaluation report

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Documentation of the activities of the Large Area Crop Inventory Experiment during the 1976 Northern Hemisphere crop year is presented. A brief overview of the experiment is included as well as phase two area, yield, and production estimates for the United States Great Plains, Canada, and the Union of Soviet Socialist Republics spring winter wheat regions. The accuracies of these estimates are compared with independent government estimates. Accuracy assessment of the United States Great Plains yardstick region based on a through blind sight analysis is given, and reasons for variations in estimating performance are discussed. Other phase two technical activities including operations, exploratory analysis, reporting, methods of assessment, phase three and advanced system design, technical issues, and developmental activities are also included.

  3. Large scale land use cartography of special areas

    SciTech Connect

    Amico, F.D.; Maccarone, D.; Pandiscia, G.V.

    1996-11-01

    On 06 October 1993 an aerial remote sensing mission has been done on the {open_quote}Mounts of the Sila{close_quotes} area, using a DAEDALUS ATM multispectral scanner, in the framework of the TELAER project, supported by I.A.S.M. (Istituto per l`Assistenza e lo Sviluppo del Mezzogiorno). The study area is inside the National Park of Calabria, well known for its coniferous forests. The collected imagery were used to produce a large scale land use cartography, on the scale of 1 to 5000, extracting information on natural and anthropical vegetation from the multispectral images, with the aid of stereo photos acquired simultaneously. 5 refs., 1 fig., 1 tab.

  4. Development of large area fast microchannel plate photo-detectors

    NASA Astrophysics Data System (ADS)

    Byrum, Karen

    2011-05-01

    We report on a cross-disciplined, multi-institutional effort to develop large-scale 'frugal' photo-detectors capable of mm-scale space resolution and pico-second time resolution. This new R&D effort is being led by the High Energy Physics branch within DOE. The large-area fast photodetectors (LAPPD) being developed would have applications in many fields, including particle physics, astrophysics, nuclear sciences, and medical imaging. The basic approach uses novel inexpensive micro channel pores which have been functionalized using a technique called atomic layer deposition. A custom anode and fast electronics are used to readout the photodetector. High quantum efficiency photocathodes are also being explored. The R&D program includes detailed testing and end to end simulations.

  5. Large area III-V infrared focal planes

    NASA Astrophysics Data System (ADS)

    Gunapala, S. D.; Ting, D. Z.; Hill, C. J.; Nguyen, J.; Soibel, A.; Rafol, S. B.; Keo, S. A.; Mumolo, J. M.; Lee, M. C.; Liu, J. K.; Yang, B.; Liao, A.

    2011-05-01

    Jet Propulsion Laboratory is actively developing the III-V based infrared detector and focal plane arrays (FPAs) for remote sensing and imaging applications. Currently, we are working on Superlattice detectors, multi-band quantum well infrared photodetectors (QWIPs), and quantum dot infrared photodetector (QDIPs) technologies suitable for high pixel-pixel uniformity and high pixel operability large area imaging arrays. In this paper, we will discuss the demonstration of long-wavelength 1 K × 1 K QDIP FPA, 1 K × 1K QWIP FPA, the first demonstration of the megapixel-simultaneously-readable and pixel-co-registered dual-band QWIP FPA, and demonstration of the first mid-wave and long-wave 1K × 1K superlattice FPA. In addition, we will discuss the advantages of III-V material system in the context of large format infrared FPAs.

  6. MILDOS-AREA: An enhanced version of MILDOS for large-area sources

    SciTech Connect

    Yuan, Y.C.; Wang, J.H.C.; Zielen, A.

    1989-06-01

    The MILDOS-AREA computer code is a modified version of the MILDOS code, which estimates the radiological impacts of airborne emissions from uranium mining and milling facilities or any other large-area source involving emissions of radioisotopes of the uranium-238 series. MILDOS-AREA is designed for execution on personal computers. The modifications incorporated in the MILDOS-AREA code provide enhanced capabilities for calculating doses from large-area sources and update dosimetry calculations. The major revision from the original MILDOS code is the treatment of atmospheric dispersion from area sources: MILDOS-AREA substitutes a finite element integration approach for the virtual-point method (the algorithm used in the original MILDOS code) when specified by the user. Other revisions include the option of using Martin-Tickvart dispersion coefficients in place of Briggs coefficients for a given source, consideration of plume reflection, and updated internal dosimetry calculations based on the most recent recommendations of the International Commission on Radiation Protection and the age-specific dose calculation methodology developed by Oak Ridge National Laboratory. This report also discusses changes in computer code structure incorporated into MILDOS-AREA, summarizes data input requirements, and provides instructions for installing and using the program on personal computers. 15 refs., 9 figs., 26 tabs.

  7. Large area photodetector based on microwave cavity perturbation techniques

    SciTech Connect

    Braggio, C. Carugno, G.; Sirugudu, R. K.; Lombardi, A.; Ruoso, G.

    2014-07-28

    We present a preliminary study to develop a large area photodetector, based on a semiconductor crystal placed inside a superconducting resonant cavity. Laser pulses are detected through a variation of the cavity impedance, as a consequence of the conductivity change in the semiconductor. A novel method, whereby the designed photodetector is simulated by finite element analysis, makes it possible to perform pulse-height spectroscopy on the reflected microwave signals. We measure an energy sensitivity of 100 fJ in the average mode without the employment of low noise electronics and suggest possible ways to further reduce the single-shot detection threshold, based on the results of the described method.

  8. Large Area Crop Inventory Experiment (LACIE). Executive summary

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The author has identified the following significant results. The Large Area Crop Inventory Experiment (LACIE), completed June 30, 1978, has met the USDA at-harvest goals (90% accuracy with a 90% confidence level) in the US Great Plains and U.S.S.R. for two consecutive years. In addition, in the U.S.S.R., LACIE indicated a shortfall in the '76-'77 wheat crop about two months prior to harvest, thus demonstrating the capability of LACIE to make accurate preharvest estimates.

  9. Method of manufacturing a large-area segmented photovoltaic module

    DOEpatents

    Lenox, Carl

    2013-11-05

    One embodiment of the invention relates to a segmented photovoltaic (PV) module which is manufactured from laminate segments. The segmented PV module includes rectangular-shaped laminate segments formed from rectangular-shaped PV laminates and further includes non-rectangular-shaped laminate segments formed from rectangular-shaped and approximately-triangular-shaped PV laminates. The laminate segments are mechanically joined and electrically interconnected to form the segmented module. Another embodiment relates to a method of manufacturing a large-area segmented photovoltaic module from laminate segments of various shapes. Other embodiments relate to processes for providing a photovoltaic array for installation at a site. Other embodiments and features are also disclosed.

  10. Laterally periodic resonator for large-area gain lasers.

    PubMed

    Feng, Yan; Ueda, Ken-Ichi

    2003-03-24

    Laterally periodic resonators, which can be constructed by use of transversely periodic phase- or amplitude-modulating elements in a cavity, are proposed for stabilization and generation of transversely coherent output from large-area gain. Lasers with periodic resonators have the combined features of conventional cavities and laser arrays. Significant low-order transverse modes and mode discrimination of a sample resonator with intracavity periodic phase elements are investigated numerically by the iteration method. Wave-propagation calculations are carried out by use of a fast Fourier transform, and a modified Prony method is used to evaluate wave functions and losses of transverse modes. Results of numerical calculations are consistent with expectations.

  11. Large area nuclear particle detectors using ET materials

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The purpose of this SBIR Phase 1 feasibility effort was to demonstrate the usefulness of Quantex electron-trapping (ET) materials for spatial detection of nuclear particles over large areas. This demonstration entailed evaluating the prompt visible scintillation as nuclear particles impinged on films of ET materials, and subsequently detecting the nuclear particle impingement information pattern stored in the ET material, by means of the visible-wavelength luminescence produced by near-infrared interrogation. Readily useful levels of scintillation and luminescence outputs are demonstrated.

  12. Large-Scale Compton Imaging for Wide-Area Surveillance

    SciTech Connect

    Lange, D J; Manini, H A; Wright, D M

    2006-03-01

    We study the performance of a large-scale Compton imaging detector placed in a low-flying aircraft, used to search wide areas for rad/nuc threat sources. In this paper we investigate the performance potential of equipping aerial platforms with gamma-ray detectors that have photon sensitivity up to a few MeV. We simulate the detector performance, and present receiver operating characteristics (ROC) curves for a benchmark scenario using a {sup 137}Cs source. The analysis uses a realistic environmental background energy spectrum and includes air attenuation.

  13. LACIE large area acreage estimation. [United States of America

    NASA Technical Reports Server (NTRS)

    Chhikara, R. S.; Feiveson, A. H. (Principal Investigator)

    1979-01-01

    A sample wheat acreage for a large area is obtained by multiplying its small grains acreage estimate as computed by the classification and mensuration subsystem by the best available ratio of wheat to small grains acreages obtained from historical data. In the United States, as in other countries with detailed historical data, an additional level of aggregation was required because sample allocation was made at the substratum level. The essential features of the estimation procedure for LACIE countries are included along with procedures for estimating wheat acreage in the United States.

  14. High-Throughput Dry Processes for Large-Area Devices

    SciTech Connect

    BUSS,RICHARD J.; HEBNER,GREGORY A.; RUBY,DOUGLAS S.; YANG,PIN

    1999-11-01

    In October 1996, an interdisciplinary team began a three-year LDRD project to study the plasma processes of reactive ion etching and plasma-enhanced chemical vapor deposition on large-area silicon devices. The goal was to develop numerical models that could be used in a variety of applications for surface cleaning, selective etching, and thin-film deposition. Silicon solar cells were chosen as the experimental vehicle for this project because an innovative device design was identified that would benefit from immediate performance improvement using a combination of plasma etching and deposition processes. This report presents a summary of the technical accomplishments and conclusions of the team.

  15. Fermi Large Area Telescope Bright Gamma-ray Source List

    SciTech Connect

    Abdo, Aous A.; Ackermann, M.; Ajello, M.; Atwood, W.B.; Axelsson, M.; Baldini, L.; Ballet, J.; Band, D.L.; Barbiellini, Guido; Bastieri, Denis; Bechtol, K.; Bellazzini, R.; Berenji, B.; Bignami, G.F.; Bloom, Elliott D.; Bonamente, E.; Borgland, A.W.; Bregeon, J.; Brigida, M.; Bruel, P.; Burnett, Thompson H.; /more authors..

    2009-05-15

    Following its launch in 2008 June, the Fermi Gamma-ray Space Telescope (Fermi) began a sky survey in August. The Large Area Telescope (LAT) on Fermi in three months produced a deeper and better resolved map of the {gamma}-ray sky than any previous space mission. We present here initial results for energies above 100 MeV for the 205 most significant (statistical significance greater than {approx}10{sigma}) {gamma}-ray sources in these data. These are the best characterized and best localized point-like (i.e., spatially unresolved) {gamma}-ray sources in the early mission data.

  16. Ultraflexible, large-area, physiological temperature sensors for multipoint measurements

    PubMed Central

    Yokota, Tomoyuki; Inoue, Yusuke; Terakawa, Yuki; Reeder, Jonathan; Kaltenbrunner, Martin; Ware, Taylor; Yang, Kejia; Mabuchi, Kunihiko; Murakawa, Tomohiro; Sekino, Masaki; Voit, Walter; Sekitani, Tsuyoshi; Someya, Takao

    2015-01-01

    We report a fabrication method for flexible and printable thermal sensors based on composites of semicrystalline acrylate polymers and graphite with a high sensitivity of 20 mK and a high-speed response time of less than 100 ms. These devices exhibit large resistance changes near body temperature under physiological conditions with high repeatability (1,800 times). Device performance is largely unaffected by bending to radii below 700 µm, which allows for conformal application to the surface of living tissue. The sensing temperature can be tuned between 25 °C and 50 °C, which covers all relevant physiological temperatures. Furthermore, we demonstrate flexible active-matrix thermal sensors which can resolve spatial temperature gradients over a large area. With this flexible ultrasensitive temperature sensor we succeeded in the in vivo measurement of cyclic temperatures changes of 0.1 °C in a rat lung during breathing, without interference from constant tissue motion. This result conclusively shows that the lung of a warm-blooded animal maintains surprising temperature stability despite the large difference between core temperature and inhaled air temperature. PMID:26554008

  17. Large-area settlement pattern recognition from Landsat-8 data

    NASA Astrophysics Data System (ADS)

    Wieland, Marc; Pittore, Massimiliano

    2016-09-01

    The study presents an image processing and analysis pipeline that combines object-based image analysis with a Support Vector Machine to derive a multi-layered settlement product from Landsat-8 data over large areas. 43 image scenes are processed over large parts of Central Asia (Southern Kazakhstan, Kyrgyzstan, Tajikistan and Eastern Uzbekistan). The main tasks tackled by this work include built-up area identification, settlement type classification and urban structure types pattern recognition. Besides commonly used accuracy assessments of the resulting map products, thorough performance evaluations are carried out under varying conditions to tune algorithm parameters and assess their applicability for the given tasks. As part of this, several research questions are being addressed. In particular the influence of the improved spatial and spectral resolution of Landsat-8 on the SVM performance to identify built-up areas and urban structure types are evaluated. Also the influence of an extended feature space including digital elevation model features is tested for mountainous regions. Moreover, the spatial distribution of classification uncertainties is analyzed and compared to the heterogeneity of the building stock within the computational unit of the segments. The study concludes that the information content of Landsat-8 images is sufficient for the tested classification tasks and even detailed urban structures could be extracted with satisfying accuracy. Freely available ancillary settlement point location data could further improve the built-up area classification. Digital elevation features and pan-sharpening could, however, not significantly improve the classification results. The study highlights the importance of dynamically tuned classifier parameters, and underlines the use of Shannon entropy computed from the soft answers of the SVM as a valid measure of the spatial distribution of classification uncertainties.

  18. Large area x-ray detectors for cargo radiography

    NASA Astrophysics Data System (ADS)

    Bueno, C.; Albagli, D.; Bendahan, J.; Castleberry, D.; Gordon, C.; Hopkins, F.; Ross, W.

    2007-04-01

    Large area x-ray detectors based on phosphors coupled to flat panel amorphous silicon diode technology offer significant advances for cargo radiologic imaging. Flat panel area detectors provide large object coverage offering high throughput inspections to meet the high flow rate of container commerce. These detectors provide excellent spatial resolution when needed, and enhanced SNR through low noise electronics. If the resolution is reduced through pixel binning, further advances in SNR are achievable. Extended exposure imaging and frame averaging enables improved x-ray penetration of ultra-thick objects, or "select-your-own" contrast sensitivity at a rate many times faster than LDAs. The areal coverage of flat panel technology provides inherent volumetric imaging with the appropriate scanning methods. Flat panel area detectors have flexible designs in terms of electronic control, scintillator selection, pixel pitch, and frame rates. Their cost is becoming more competitive as production ramps up for the healthcare, nondestructive testing (NDT), and homeland protection industries. Typically used medical and industrial polycrystalline phosphor materials such as Gd2O2S:Tb (GOS) can be applied to megavolt applications if the phosphor layer is sufficiently thick to enhance x-ray absorption, and if a metal radiator is used to augment the quantum detection efficiency and reduce x-ray scatter. Phosphor layers ranging from 0.2-mm to 1-mm can be "sandwiched" between amorphous silicon flat panel diode arrays and metal radiators. Metal plates consisting of W, Pb or Cu, with thicknesses ranging from 0.25-mm to well over 1-mm can be used by covering the entire area of the phosphor plate. In some combinations of high density metal and phosphor layers, the metal plate provides an intensification of 25% in signal due to electron emission from the plate and subsequent excitation within the phosphor material. This further improves the SNR of the system.

  19. Prospects for Pulsar Studies with the GLAST Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.

    2007-01-01

    The Large Area Telescope (LAT) on the Gamma-ray Large Area Space Telescope (GLAST), due to launch in November 2007, will have unprecedented sensitivity and energy resolution for gamma-rays in the range of 30 MeV to 200 GeV. GLAST is therefore expected to provide major advances in the understanding of high-energy emission from rotation-powered pulsars. As the only presently known galactic GeV source class; pulsars will be one of the most important sources for study with GLAST. The main science goals of the LAT for pulsar studies include an increase in the number of detected radio-loud and radio-quiet gamma-ray pulsars, including millisecond pulsars, giving much better statistics for elucidating population characteristics, measurement of the high-energy spectrum and the shape of spectral cutoffs and determining pulse profiles for a variety of pulsars of different age. Further, measurement of phase-resolved spectra and energy dependent pulse profiles of the brighter pulsars should allow detailed tests of magnetospheric particle acceleration and radiation mechanisms, by comparing data with theoretical models that have been developed. Additionally, the LAT will have the sensitivity to allow blind pulsation searches of nearly all unidentified EGRET sources, to possibly uncover more radio-quiet Geminga-like pulsars.

  20. Prospects for Pulsar Studies with the GLAST Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.

    2006-01-01

    The Large Area Telescope (LAT) on the Gamma-ray Large Area Space Telescope (GLAST) will have unprecedented sensitivity and energy resolution for gamma-rays in the range of 30 MeV to 200 GeV. GLAST is therefore expected to provide major advances in the understanding of high-energy emission from rotation-powered pulsars. As the only presently known galactic GeV source class, pulsars will be one of the most important sources for study with GLAST. The main science goals of the LAT for pulsar studies include an increase in the number of detected radio-loud and radio-quiet gamma ray pulsars, including millisecond pulsars, giving much better statistics for elucidating population characteristics, measurement of the high-energy spectrum and the shape of spectral cutoffs and determining pulse profiles for a variety of pulsars of different age. Further, measurement of phase-resolved spectra and energy dependent pulse profiles of the brighter pulsars should allow detailed tests of magnetospheric particle acceleration and radiation mechanisms, by comparing data with theoretical models that have been developed. Additionally, the LAT will have the sensitivity to allow blind pulsation searches of nearly all unidentified EGRET sources, to possibly uncover more radio-quiet Geminga-like pulsars.

  1. Prospects for Pulsar Studies with the GLAST Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Harding, Alice K.

    2007-01-01

    The Large Area Telescope (LAT) on the Gamma-ray Large Area Space Telescope (GLAST), due to launch in November 2007, will have unprecedented sensitivity and energy resolution for gamma-rays in the range of 30 MeV to 200 GeV. GLAST is therefore expected to provide major advances in the understanding of high-energy emission from rotation-powered p ulsars. As the only presently known galactic GeV source class, pulsar s will be one of the most important sources for study with GLAST. The main science goals of the LAT for pulsar studies include an increase in the number of detected radio-loud and radio-quiet gamma-ray pulsar s, including millisecond pulsars, giving much better statistics for e lucidating population characteristics, measurement of the high-energy spectrum and the shape of spectral cutoffs and determining pulse profiles for a variety of pulsars of different age. Further, measurement of phase-resolved spectra and energy dependent pulse profiles of the brighter pulsars should allow detailed tests of magnetospheric partic le acceleration and radiation mechanisms, by comparing data with theo retical models that have been developed. Additionally, the LAT will have the sensitivity to allow blind pulsation searches of nearly all un identified EGRET sources, to possibly uncover more radio-quiet Geming a-like pulsars.

  2. Large-Area Zone Plate Fabrication with Optical Lithography

    SciTech Connect

    Denbeaux, G.

    2011-09-09

    Zone plates as condenser optics for x-ray microscopes offer simple optical designs for both illumination and spectral resolution when used as a linear monochromator. However, due to the long write times for electron beam lithography, both the availability and the size of zone plates for condensers have been limited. Since the resolution provided by the linear monochromator scales almost linearly with the diameter of the zone plate, the full potential for zone plate monochromators as illumination systems for x-ray microscopes has not been achieved. For example, the 10-mm-diameter zone plate has demonstrated a spectral resolution of E/{Delta}E = 700[1], but with a 26-mm-diameter zone plate, the calculated spectral resolution is higher than E/{Delta}E = 3000. These large-area zone plates are possible to fabricate with the leading edge semiconductor lithography tools such as those available at the College of Nanoscale Science and Engineering at the University at Albany. One of the lithography tools available is the ASML TWINSCAN XT: 1950i with 37-nm resolution [2]. A single 300-mm wafer can contain more than 60 fields, each with a large area condenser, and the throughput of the tool can be more than one wafer every minute.

  3. Development of a Large-Area Ultracold Neutron Detector

    NASA Astrophysics Data System (ADS)

    Stoffel, Jenna; Liu, Chen-Yu; UCN Tau Collaboration

    2015-10-01

    To improve our knowledge in particle physics and cosmology, including big-bang nucleosynthesis, we need a more precise and accurate measurement of the lifetime of free neutrons. Though there have been many attempts to measure the neutron lifetime, discrepancies exist between the two major experimental techniques of the beam and the bottle methods. To resolve this discrepancy, the UCN τ experiment will trap ultracold neutrons (UCNs) to perform lifetime measurements to the 1-second level. To accomplish this goal, we are developing a large-area, high-efficiency UCN detector. We construct a scintillating UCN detector by evaporating a thin film of boron-10 onto an airbrushed layer of zinc sulfide (ZnS); the 10B-coated ZnS scintillating film is then glued to wavelength-shifting plastic, which acts as a light guide to direct photons into modern silicon photomultipliers. This new detector has similar efficiency and background noise as the previously-used ion gas detectors, but can be easily scaled up to cover large areas for many applications. The new detector opens up exciting new ways to study systematic effects, as they hold the key to the interpretation of neutron lifetime.

  4. An advanced open path atmospheric pollution monitor for large areas

    SciTech Connect

    Taylor, L.; Suhre, D.; Mani, S.

    1996-12-31

    Over 100 million gallons of radioactive and toxic waste materials generated in weapon materials production are stored in 322 tanks buried within large areas at DOE sites. Toxic vapors occur in the tank headspace due to the solvents used and chemical reactions within the tanks. To prevent flammable or explosive concentration of volatile vapors, the headspace are vented, either manually or automatically, to the atmosphere when the headspace pressure exceeds preset values. Furthermore, 67 of the 177 tanks at the DOE Hanford Site are suspected or are known to be leaking into the ground. These underground storage tanks are grouped into tank farms which contain closely spaced tanks in areas as large as 1 km{sup 2}. The objective of this program is to protect DOE personnel and the public by monitoring the air above these tank farms for toxic air pollutants without the monitor entering the tanks farms, which can be radioactive. A secondary objective is to protect personnel by monitoring the air above buried 50 gallon drums containing moderately low radioactive materials but which could also emit toxic air pollutants.

  5. Large-Area Zone Plate Fabrication with Optical Lithography

    NASA Astrophysics Data System (ADS)

    Denbeaux, G.

    2011-09-01

    Zone plates as condenser optics for x-ray microscopes offer simple optical designs for both illumination and spectral resolution when used as a linear monochromator. However, due to the long write times for electron beam lithography, both the availability and the size of zone plates for condensers have been limited. Since the resolution provided by the linear monochromator scales almost linearly with the diameter of the zone plate, the full potential for zone plate monochromators as illumination systems for x-ray microscopes has not been achieved. For example, the 10-mm-diameter zone plate has demonstrated a spectral resolution of E/ΔE = 700 [1], but with a 26-mm-diameter zone plate, the calculated spectral resolution is higher than E/ΔE = 3000. These large-area zone plates are possible to fabricate with the leading edge semiconductor lithography tools such as those available at the College of Nanoscale Science and Engineering at the University at Albany. One of the lithography tools available is the ASML TWINSCAN XT: 1950i with 37-nm resolution [2]. A single 300-mm wafer can contain more than 60 fields, each with a large area condenser, and the throughput of the tool can be more than one wafer every minute.

  6. Priority Areas for Large Mammal Conservation in Equatorial Guinea

    PubMed Central

    Murai, Mizuki; Ruffler, Heidi; Berlemont, Antoine; Campbell, Genevieve; Esono, Fidel; Agbor, Anthony; Mbomio, Domingo; Ebana, Agustín; Nze, Antonio; Kühl, Hjalmar S.

    2013-01-01

    Hunting is one of the main driving forces behind large mammal density distribution in many regions of the world. In tropical Africa, urban demand for bushmeat has been shown to dominate over subsistence hunting and its impact often overrides spatial-ecological species characteristics. To effectively protect remaining mammal populations the main factors that influence their distribution need to be integrated into conservation area prioritisation and management plans. This information has been lacking for Río Muni, Equatorial Guinea, as prior studies have been outdated or have not systematically covered the continental region of the country. In this study we evaluated: 1) the relative importance of local vs. commercial hunting; 2) wildlife density of protected vs. non-protected areas; and 3) the importance of ecological factors vs. human influence in driving mammal density distribution in Río Muni. We adopted a systematic countrywide line transect approach with particular focus on apes and elephants, but also including other mammal species. For analysis of field data we used generalised linear models with a set of predictor variables representing ecological conditions, anthropogenic pressure and protected areas. We estimate that there are currently 884 (437–1,789) elephants and 11,097 (8,719–13,592) chimpanzees and gorillas remaining in Río Muni. The results indicate strong hunting pressures on both local and commercial levels, with roads demonstrating a negative impact on elephants and overall mammal body mass. Protected areas played no role in determining any of the mammal species distributions and significant human hunting signs were found inside these protected areas, illustrating the lack of environmental law enforcement throughout the country. Río Muni is currently under-represented in conservation efforts in Western Equatorial Africa, and we recommend a focus on cross-boundary conservation, in particular in the Monte Alén-Monts de Cristal and R

  7. Ultra-stiff large-area carpets of carbon nanotubes.

    PubMed

    Meysami, Seyyed Shayan; Dallas, Panagiotis; Britton, Jude; Lozano, Juan G; Murdock, Adrian T; Ferraro, Claudio; Gutierrez, Eduardo Saiz; Rijnveld, Niek; Holdway, Philip; Porfyrakis, Kyriakos; Grobert, Nicole

    2016-06-01

    Herewith, we report the influence of post-synthesis heat treatment (≤2350 °C and plasma temperatures) on the crystal structure, defect density, purity, alignment and dispersibility of free-standing large-area (several cm(2)) carpets of ultra-long (several mm) vertically aligned multi-wall carbon nanotubes (VA-MWCNTs). VA-MWCNTs were produced in large quantities (20-30 g per batch) using a semi-scaled-up aerosol-assisted chemical vapour deposition (AACVD) setup. Electron and X-ray diffraction showed that the heat treatment at 2350 °C under inert atmosphere purifies, removes residual catalyst particles, and partially aligns adjacent single crystals (crystallites) in polycrystalline MWCNTs. The purification and improvement in the crystallites alignment within the MWCNTs resulted in reduced dispersibility of the VA-MWCNTs in liquid media. High-resolution microscopy revealed that the crystallinity is improved in scales of few tens of nanometres while the point defects remain largely unaffected. The heat treatment also had a marked benefit on the mechanical properties of the carpets. For the first time, we report compression moduli as high as 120 MPa for VA-MWCNT carpets, i.e. an order of magnitude higher than previously reported figures. The application of higher temperatures (arc-discharge plasma, ≥4000 °C) resulted in the formation of a novel graphite-matrix composite reinforced with CVD and arc-discharge-like carbon nanotubes. PMID:27240959

  8. SPLASH: A Southern Parkes Large Area Survey in Hydroxyl

    NASA Astrophysics Data System (ADS)

    Dawson, Joanne; Caswell, James; Gomez, Jose F.; Mcclure-Griffiths, Naomi; Lo, Nadia; Jones, Paul; Dickey, John; Cunningham, Maria; Green, James; Carretti, Ettore; Ellingsen, Simon; Walsh, Andrew; Purcell, Cormac; Breen, Shari; Hennebelle, Patrick; Imai, Hiroshi; Lowe, Vicki; Gibson, Steven; Jones, Courtney; Krishnan, Vasaant

    2013-10-01

    The OH 18 cm lines are powerful and versatile probes of diffuse molecular gas, that may trace a largely unstudied component of the Galactic ISM. SPLASH (the Southern Parkes Large Area Survey in Hydroxyl) is a large, unbiased and fully-sampled survey of OH emission, absorption and masers in the Galactic Plane that will achieve sensitivities an order of magnitude better than previous work. The survey will answer critical questions on the global distribution of diffuse OH, the degree to which it traces ‘hidden’ material caught between the regimes probed by traditional tracers of the neutral ISM, and its role as a probe of molecular cloud formation. As a blind survey for all four ground-state transitions, SPLASH will also detect many new OH masers, facilitating a broad range of astrophysical studies. This proposal requests 670 hours spread over two semesters to complete Phase 1 of the SPLASH project, which will map 152 square degrees in the inner Galactic Plane, including the Galactic Centre. Following the ongoing success of the project, we request that its pre-graded status be renewed for a final two semesters.

  9. Nephrologic Impact of Hurricanes Katrina and Rita in Areas Not Directly Affected.

    PubMed

    Dossabhoy, Neville R; Qadri, Mashood; Beal, Lauren M

    2015-01-01

    Hurricanes Katrina and Rita resulted in enormous loss of life and disrupted the delivery of health care in areas affected by them. In causing mass movements of patients, natural disasters can overwhelm the resources of nephrology communities in areas not suffering direct damage. The following largely personal account evaluates the impact these hurricanes had upon the nephrology community, patients and health care providers alike, in areas not directly affected by the storms. Mass evacuation of hundreds of dialysis patients to surrounding areas overwhelmed the capacity of local hemodialysis centers. Non-availability of medical records in patients arriving without a supply of their routine medications led to confusion and sub-optimal treatment of conditions such as hypertension and congestive heart failure. Availability of cadaveric organs for transplantation was reduced in the surrounding areas, as the usual lines of communication and transportation were severed for several weeks. All of these issues led to prolong waiting times for patients on the transplant list. The hurricanes severely disrupted usual supply lines of medications to hospitals; certain rare conditions may be seen in higher numbers as a result of the shortages induced. We present the interesting surge in cases of acute kidney injury secondary to use of intravenous immune globulin.

  10. Nephrologic Impact of Hurricanes Katrina and Rita in Areas Not Directly Affected.

    PubMed

    Dossabhoy, Neville R; Qadri, Mashood; Beal, Lauren M

    2015-01-01

    Hurricanes Katrina and Rita resulted in enormous loss of life and disrupted the delivery of health care in areas affected by them. In causing mass movements of patients, natural disasters can overwhelm the resources of nephrology communities in areas not suffering direct damage. The following largely personal account evaluates the impact these hurricanes had upon the nephrology community, patients and health care providers alike, in areas not directly affected by the storms. Mass evacuation of hundreds of dialysis patients to surrounding areas overwhelmed the capacity of local hemodialysis centers. Non-availability of medical records in patients arriving without a supply of their routine medications led to confusion and sub-optimal treatment of conditions such as hypertension and congestive heart failure. Availability of cadaveric organs for transplantation was reduced in the surrounding areas, as the usual lines of communication and transportation were severed for several weeks. All of these issues led to prolong waiting times for patients on the transplant list. The hurricanes severely disrupted usual supply lines of medications to hospitals; certain rare conditions may be seen in higher numbers as a result of the shortages induced. We present the interesting surge in cases of acute kidney injury secondary to use of intravenous immune globulin. PMID:26741684

  11. Laser deposition of large-area thin films

    SciTech Connect

    Kuzanyan, A S; Petrosyan, V A; Pilosyan, S Kh; Nesterov, V M

    2011-03-31

    A new method for fabricating large-area thin films of uniform thickness on a rotating substrate is proposed. Its distinctive features are (i) the presence of a diaphragm, partially transmitting the evaporated material, between the target and substrate and (ii) the translatory motion of the rotating substrate with respect to the target at a certain velocity. The method proposed makes it possible to obtain thin films of uniform thickness on substrates with sizes limited by only the deposition chamber size. The method is experimentally verified by depositing thin CuO films on silicon substrates placed over the radius of a disk 300 mm in diameter. The deviation of the film thickness from the average value does not exceed {+-}3% throughout the entire radius, which confirms good prospects of this method for microelectronics, optical industry, and other modern technologies. (laser technology)

  12. FIRBACK: A Large Area 175 micron Survey with ISO

    NASA Astrophysics Data System (ADS)

    Lagache, Guilaine

    We have conducted a deep cosmological large area survey at 175 microns with the ISOPHOT instrument in several high latitude regions relatively free of cirrus contamination. The main, but striking, result of this survey is that number counts of sources above 100 mJy is larger by about an order of magnitude than the extrapolation of the nearby IRAS 60 microns population of infrared galaxies. Nevertheless, these counts are consistent with predictions of the source population responsible for the Cosmic Far InfraRed Background detected with COBE. The FIRBACK collaboration involves J. L. Puget, D. L. Clements, H. Dole, R. Gispert, W. T. Reach, F. R. Bouchet, C. Cesarsky, F. X. Desert, D. Elbaz, A. Franceschini, B. Guiderdoni, M. Harwit, D. Lemke, R. Laureijs and A. F. M Moorwood.

  13. Optical Distortion Evaluation in Large Area Windows using Interferometry

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert C.; Skow, Miles; Nurge, Mark A.

    2015-01-01

    It is important that imagery seen through large area windows, such as those used on space vehicles, not be substantially distorted. Many approaches are described in the literature for measuring the distortion of an optical window, but most suffer from either poor resolution or processing difficulties. In this paper a new definition of distortion is presented, allowing accurate measurement using an optical interferometer. This new definition is shown to be equivalent to the definitions provided by the military and the standards organizations. In order to determine the advantages and disadvantages of this new approach the distortion of an acrylic window is measured using three different methods; image comparison, Moiré interferometry, and phase-shifting interferometry.

  14. Plasma generating apparatus for large area plasma processing

    DOEpatents

    Tsai, Chin-Chi; Gorbatkin, Steven M.; Berry, Lee A.

    1991-01-01

    A plasma generating apparatus for plasma processing applications is based on a permanent magnet line-cusp plasma confinement chamber coupled to a compact single-coil microwave waveguide launcher. The device creates an electron cyclotron resonance (ECR) plasma in the launcher and a second ECR plasma is created in the line cusps due to a 0.0875 tesla magnetic field in that region. Additional special magnetic field configuring reduces the magnetic field at the substrate to below 0.001 tesla. The resulting plasma source is capable of producing large-area (20-cm diam), highly uniform (.+-.5%) ion beams with current densities above 5 mA/cm.sup.2. The source has been used to etch photoresist on 5-inch diam silicon wafers with good uniformity.

  15. Plasma generating apparatus for large area plasma processing

    DOEpatents

    Tsai, C.C.; Gorbatkin, S.M.; Berry, L.A.

    1991-07-16

    A plasma generating apparatus for plasma processing applications is based on a permanent magnet line-cusp plasma confinement chamber coupled to a compact single-coil microwave waveguide launcher. The device creates an electron cyclotron resonance (ECR) plasma in the launcher and a second ECR plasma is created in the line cusps due to a 0.0875 tesla magnetic field in that region. Additional special magnetic field configuring reduces the magnetic field at the substrate to below 0.001 tesla. The resulting plasma source is capable of producing large-area (20-cm diam), highly uniform (.+-.5%) ion beams with current densities above 5 mA/cm[sup 2]. The source has been used to etch photoresist on 5-inch diam silicon wafers with good uniformity. 3 figures.

  16. Large-area multilayer infrared nano-wire grid polarizers

    NASA Astrophysics Data System (ADS)

    Gayduk, Alexey E.; Prinz, Victor Ya.; Seleznev, Vladimir A.; Rechkunov, Sergey N.

    2016-03-01

    We have developed a technology for fabricating infrared polarizers based on double- and four-layer metal-dielectric nanogratings. Due to the use of nanoimprint lithography, the size of fabricated samples with 190-nm grating period could be made exceeding 170 cm2. The fabricated polarizers are flexible, and they have high quality over the entire area of the sample. Spectrophotometric measurements and numerical simulations have showed that the polarizers exhibited a large transmission coefficient and a high extinction ratio (over 3 ṡ 104). In order to expand applications of polarizers to the bio-inspired wide field-of-view systems, technology for fabricating polarizers on curved surfaces prepared by 3D printing has been developed. The obtained results offer much promise for polarimetry purposes.

  17. Large area MEMS based ultrasound device for cancer detection

    NASA Astrophysics Data System (ADS)

    Wodnicki, Robert; Thomenius, Kai; Ming Hooi, Fong; Sinha, Sumedha P.; Carson, Paul L.; Lin, Der-Song; Zhuang, Xuefeng; Khuri-Yakub, Pierre; Woychik, Charles

    2011-08-01

    We present image results obtained using a prototype ultrasound array that demonstrates the fundamental architecture for a large area MEMS based ultrasound device for detection of breast cancer. The prototype array consists of a tiling of capacitive Micromachined Ultrasound Transducers (cMUTs) that have been flip-chip attached to a rigid organic substrate. The pitch on the cMUT elements is 185 μm and the operating frequency is nominally 9 MHz. The spatial resolution of the new probe is comparable to those of production PZT probes; however the sensitivity is reduced by conditions that should be correctable. Simulated opposed-view image registration and Speed of Sound volume reconstruction results for ultrasound in the mammographic geometry are also presented.

  18. PROSPECTS FOR GRB SCIENCE WITH THE FERMI LARGE AREA TELESCOPE

    SciTech Connect

    Band, D. L.; Axelsson, M.; Baldini, L.; Bellazzini, R.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Battelino, M.; Bissaldi, E.; Bogaert, G.; Chiang, J.; Do Couto e Silva, E.; Cohen-Tanugi, J.; Cutini, S.; De Palma, F.; Dingus, B. L.; Fishman, G.

    2009-08-20

    The Large Area Telescope (LAT) instrument on the Fermi mission will reveal the rich spectral and temporal gamma-ray burst (GRB) phenomena in the >100 MeV band. The synergy with Fermi's Gamma-ray Burst Monitor detectors will link these observations to those in the well explored 10-1000 keV range; the addition of the >100 MeV band observations will resolve theoretical uncertainties about burst emission in both the prompt and afterglow phases. Trigger algorithms will be applied to the LAT data both onboard the spacecraft and on the ground. The sensitivity of these triggers will differ because of the available computing resources onboard and on the ground. Here we present the LAT's burst detection methodologies and the instrument's GRB capabilities.

  19. Large area nuclear particle detectors using ET materials, phase 2

    NASA Technical Reports Server (NTRS)

    Wrigley, Charles Y.; Storti, George M.; Walter, Lee; Mathews, Scott

    1990-01-01

    This report presents work done under a Phase 2 SBIR contract for demonstrating large area detector planes utilizing Quantex electron trapping materials as a film medium for storing high-energy nuclide impingement information. The detector planes utilize energy dissipated by passage of the high-energy nuclides to produce localized populations of electrons stored in traps. Readout of the localized trapped electron populations is effected by scanning the ET plane with near-infrared, which frees the trapped electrons and results in optical emission at visible wavelengths. The effort involved both optimizing fabrication technology for the detector planes and developing a readout system capable of high spatial resolution for displaying the recorded nuclide passage tracks.

  20. Terahertz and infrared spectroscopy of gated large-area graphene.

    PubMed

    Ren, Lei; Zhang, Qi; Yao, Jun; Sun, Zhengzong; Kaneko, Ryosuke; Yan, Zheng; Nanot, Sébastien; Jin, Zhong; Kawayama, Iwao; Tonouchi, Masayoshi; Tour, James M; Kono, Junichiro

    2012-07-11

    We have fabricated a centimeter-size single-layer graphene device with a gate electrode, which can modulate the transmission of terahertz and infrared waves. Using time-domain terahertz spectroscopy and Fourier-transform infrared spectroscopy in a wide frequency range (10-10 000 cm(-1)), we measured the dynamic conductivity change induced by electrical gating and thermal annealing. Both methods were able to effectively tune the Fermi energy, E(F), which in turn modified the Drude-like intraband absorption in the terahertz as well as the "2E(F) onset" for interband absorption in the mid-infrared. These results not only provide fundamental insight into the electromagnetic response of Dirac fermions in graphene but also demonstrate the key functionalities of large-area graphene devices that are desired for components in terahertz and infrared optoelectronics. PMID:22663563

  1. Towards Large Area Growth of 3C-SiC

    SciTech Connect

    Vasiliauskas, Remigijus; Liljedahl, Rickard; Syvaejaervi, Mikael; Yakimova, Rositza

    2010-11-01

    In this work we have analyzed the possibility of upscaling the growth of 3C-SiC. The growth was done at different temperatures to find limiting mechanisms of the growth rate and to examine the morphology of grown layers. Coverage by 3C-SiC increases when increasing temperature, however more twins appeared. Activation energy of the growth is 130 kcal/mol--showing that growth rate limiting mechanism is sublimation of the source. We discuss the influence of large area 6H-SiC wafers on the formation of 3C-SiC, in which the change in basal plane orientation could also influence the growth of 3C-SiC.

  2. Direct LED backlight for large area LCD TVs: brightness analysis

    NASA Astrophysics Data System (ADS)

    Sun, Ching-Cherng; Moreno, Ivan; Chung, Shih-Hsun; Chien, Wei-Ting; Hsieh, Chih-To; Yang, Tsung-Hsun

    2007-09-01

    A direct or bottom LED backlight is a key concept in large area LCD displays because it does not use a light guide, is flat, and is easy to assemble. In this paper, a method of luminance management for a bottom LED backlight is proposed and demonstrated. We analytically calculate both the power consumption and brightness uniformity in function of: screen brightness, screen size, backlight thickness, transmittance of the LCD panel, reflective cavity efficiency, gain and cone angle of enhancement films, LED array configuration, and the average luminous flux and radiation pattern of a single LED. Moreover, a 42-inch LCD television with this backlight design approach is made and demonstrated. The bottom backlight incorporates an array of RGGB 4-in-1 multi-chip LEDs within a highly reflective box behind a diffuser and a dual brightness enhancement film. We predict with an accuracy of 94% the brightness uniformity and with 96% the luminance level.

  3. Pulsed-laser deposition of oxides over large areas

    NASA Astrophysics Data System (ADS)

    Greer, James A.; Van Hook, H. J.

    1991-03-01

    Due to its short wavelength and high peak power the excimer laser has become the de facto choice for Pulsed Laser Deposition (PLD) of ceramic superconductors as well as other complex chemical compounds. This paper will describe a unique excimer-based laser deposition system which is capable of producing thin films of a variety of oxide compounds or other materials over large areas (up to 46 cm2). Well over a dozen chemical compounds have been deposited with this system for a wide variety of electronic applications. Also the PLD technique has been adapted to grow thin films on the internal surface of cored cylindrical substrates in order to form resonant microwave cavity structures. The uniformity morphology and electrical properties of films grown on both planar and cylindrical substrates will be discussed.

  4. A new approach for defect inspection on large area masks

    NASA Astrophysics Data System (ADS)

    Scheuring, Gerd; Döbereiner, Stefan; Hillmann, Frank; Falk, Günther; Brück, Hans-Jürgen

    2007-02-01

    Besides the mask market for IC manufacturing, which mainly uses 6 inch sized masks, the market for the so called large area masks is growing very rapidly. Typical applications of these masks are mainly wafer bumping for current packaging processes, color filters on TFTs, and Flip Chip manufacturing. To expose e.g. bumps and similar features on 200 mm wafers under proximity exposure conditions 9 inch masks are used, while in 300 mm wafer bumping processes (Fig. 1) 14 inch masks are handled. Flip Chip manufacturing needs masks up to 28 by 32 inch. This current maximum mask dimension is expected to hold for the next 5 years in industrial production. On the other hand shrinking feature sizes, just as in case of the IC masks, demand enhanced sensitivity of the inspection tools. A defect inspection tool for those masks is valuable for both the mask maker, who has to deliver a defect free mask to his customer, and for the mask user to supervise the mask behavior conditions during its lifetime. This is necessary because large area masks are mainly used for proximity exposures. During this process itself the mask is vulnerable by contacting the resist on top of the wafers. Therefore a regular inspection of the mask after 25, 50, or 100 exposures has to be done during its whole lifetime. Thus critical resist contamination and other defects, which lead to yield losses, can be recognized early. In the future shrinking feature dimensions will require even more sensitive and reliable defect inspection methods than they do presently. Besides the sole inspection capability the tools should also provide highly precise measurement capabilities and extended review options.

  5. Large Area Nondestructive Evaluation of a Fatigue Loaded Composite Structure

    NASA Technical Reports Server (NTRS)

    Zalameda, Joseph N.; Burke, Eric R.; Horne, Michael R.; Madaras, Eric I.

    2016-01-01

    Large area nondestructive evaluation (NDE) inspections are required for fatigue testing of composite structures to track damage initiation and growth. Of particular interest is the progression of damage leading to ultimate failure to validate damage progression models. In this work, passive thermography and acoustic emission NDE were used to track damage growth up to failure of a composite three-stringer panel. Fourteen acoustic emission sensors were placed on the composite panel. The signals from the array were acquired simultaneously and allowed for acoustic emission location. In addition, real time thermal data of the composite structure were acquired during loading. Details are presented on the mapping of the acoustic emission locations directly onto the thermal imagery to confirm areas of damage growth leading to ultimate failure. This required synchronizing the acoustic emission and thermal data with the applied loading. In addition, processing of the thermal imagery which included contrast enhancement, removal of optical barrel distortion and correction of angular rotation before mapping the acoustic event locations are discussed.

  6. Development of a large area space solar cell assembly

    NASA Technical Reports Server (NTRS)

    Spitzer, M. B.

    1982-01-01

    The development of a large area high efficiency solar cell assembly is described. The assembly consists of an ion implanted silicon solar cell and glass cover. The important attributes of fabrication are the use of a back surface field which is compatible with a back surface reflector, and integration of coverglass application and cell fabrications. Cell development experiments concerned optimization of ion implantation processing of 2 ohm-cm boron-doped silicon. Process parameters were selected based on these experiments and cells with area of 34.3 sq cm wre fabricated. The average AMO efficiency of the twenty-five best cells was 13.9% and the best bell had an efficiency of 14.4%. An important innovation in cell encapsulation was also developed. In this technique, the coverglass is applied before the cell is sawed to final size. The coverglass and cell are then sawed as a unit. In this way, the cost of the coverglass is reduced, since the tolerance on glass size is relaxed, and costly coverglass/cell alignment procedures are eliminated. Adhesive investigated were EVA, FEP-Teflon sheet and DC 93-500. Details of processing and results are reported.

  7. Large area patterning using interference and nanoimprint lithography

    NASA Astrophysics Data System (ADS)

    Bläsi, B.; Tucher, N.; Höhn, O.; Kübler, V.; Kroyer, T.; Wellens, Ch.; Hauser, H.

    2016-04-01

    Interference lithography (IL) is the best suited technology for the origination of large area master structures with high resolution. In prior works, we seamlessly pattern areas of up to 1.2 x 1.2 m2 with periodic features, i.e. a diffraction grating with a period in the micron range. For this process we use an argon ion laser emitting at 363.8 nm. Thus, feasible periods are in the range of 100 μm to 200 nm. Edge-defined techniques or also called (self-aligned) double patterning processes can be used to double the spatial frequency of such structures. This way, we aim to reduce achievable periods further down to 100 nm. In order to replicate master structures, we make use of nanoimprint lithography (NIL) processes. In this work, we present results using IL as mastering and NIL as replication technology in the fields of photovoltaics as well as display and lighting applications. In photovoltaics different concepts like the micron-scale patterning of the front side as well as the realization of rear side diffraction gratings are presented. The benefit for each is shown on final device level. In the context of display and lighting applications, we realized various structures ranging from designed, symmetric or asymmetric, diffusers, antireflective and/or antiglare structures, polarization optical elements (wire grid polarizers), light guidance and light outcoupling structures.

  8. Edge field emission of large-area single layer graphene

    NASA Astrophysics Data System (ADS)

    Kleshch, Victor I.; Bandurin, Denis A.; Orekhov, Anton S.; Purcell, Stephen T.; Obraztsov, Alexander N.

    2015-12-01

    Field electron emission from the edges of large-area (∼1 cm × 1 cm) graphene films deposited onto quartz wafers was studied. The graphene was previously grown by chemical vapour deposition on copper. An extreme enhancement of electrostatic field at the edge of the films with macroscopically large lateral dimensions and with single atom thickness was achieved. This resulted in the creation of a blade type electron emitter, providing stable field emission at low-voltage with linear current density up to 0.5 mA/cm. A strong hysteresis in current-voltage characteristics and a step-like increase of the emission current during voltage ramp up were observed. These effects were explained by the local mechanical peeling of the graphene edge from the quartz substrate by the ponderomotive force during the field emission process. Specific field emission phenomena exhibited in the experimental study are explained by a unique combination of structural, electronic and mechanical properties of graphene. Various potential applications ranging from linear electron beam sources to microelectromechanical systems are discussed.

  9. Ultra-stiff large-area carpets of carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Meysami, Seyyed Shayan; Dallas, Panagiotis; Britton, Jude; Lozano, Juan G.; Murdock, Adrian T.; Ferraro, Claudio; Gutierrez, Eduardo Saiz; Rijnveld, Niek; Holdway, Philip; Porfyrakis, Kyriakos; Grobert, Nicole

    2016-06-01

    Herewith, we report the influence of post-synthesis heat treatment (<=2350 °C and plasma temperatures) on the crystal structure, defect density, purity, alignment and dispersibility of free-standing large-area (several cm2) carpets of ultra-long (several mm) vertically aligned multi-wall carbon nanotubes (VA-MWCNTs). VA-MWCNTs were produced in large quantities (20-30 g per batch) using a semi-scaled-up aerosol-assisted chemical vapour deposition (AACVD) setup. Electron and X-ray diffraction showed that the heat treatment at 2350 °C under inert atmosphere purifies, removes residual catalyst particles, and partially aligns adjacent single crystals (crystallites) in polycrystalline MWCNTs. The purification and improvement in the crystallites alignment within the MWCNTs resulted in reduced dispersibility of the VA-MWCNTs in liquid media. High-resolution microscopy revealed that the crystallinity is improved in scales of few tens of nanometres while the point defects remain largely unaffected. The heat treatment also had a marked benefit on the mechanical properties of the carpets. For the first time, we report compression moduli as high as 120 MPa for VA-MWCNT carpets, i.e. an order of magnitude higher than previously reported figures. The application of higher temperatures (arc-discharge plasma, >=4000 °C) resulted in the formation of a novel graphite-matrix composite reinforced with CVD and arc-discharge-like carbon nanotubes.Herewith, we report the influence of post-synthesis heat treatment (<=2350 °C and plasma temperatures) on the crystal structure, defect density, purity, alignment and dispersibility of free-standing large-area (several cm2) carpets of ultra-long (several mm) vertically aligned multi-wall carbon nanotubes (VA-MWCNTs). VA-MWCNTs were produced in large quantities (20-30 g per batch) using a semi-scaled-up aerosol-assisted chemical vapour deposition (AACVD) setup. Electron and X-ray diffraction showed that the heat treatment at 2350 °C under

  10. Llamas: Large-area microphone arrays and sensing systems

    NASA Astrophysics Data System (ADS)

    Sanz-Robinson, Josue

    Large-area electronics (LAE) provides a platform to build sensing systems, based on distributing large numbers of densely spaced sensors over a physically-expansive space. Due to their flexible, "wallpaper-like" form factor, these systems can be seamlessly deployed in everyday spaces. They go beyond just supplying sensor readings, but rather they aim to transform the wealth of data from these sensors into actionable inferences about our physical environment. This requires vertically integrated systems that span the entirety of the signal processing chain, including transducers and devices, circuits, and signal processing algorithms. To this end we develop hybrid LAE / CMOS systems, which exploit the complementary strengths of LAE, enabling spatially distributed sensors, and CMOS ICs, providing computational capacity for signal processing. To explore the development of hybrid sensing systems, based on vertical integration across the signal processing chain, we focus on two main drivers: (1) thin-film diodes, and (2) microphone arrays for blind source separation: 1) Thin-film diodes are a key building block for many applications, such as RFID tags or power transfer over non-contact inductive links, which require rectifiers for AC-to-DC conversion. We developed hybrid amorphous / nanocrystalline silicon diodes, which are fabricated at low temperatures (<200 °C) to be compatible with processing on plastic, and have high current densities (5 A/cm2 at 1 V) and high frequency operation (cutoff frequency of 110 MHz). 2) We designed a system for separating the voices of multiple simultaneous speakers, which can ultimately be fed to a voice-command recognition engine for controlling electronic systems. On a device level, we developed flexible PVDF microphones, which were used to create a large-area microphone array. On a circuit level we developed localized a-Si TFT amplifiers, and a custom CMOS IC, for system control, sensor readout and digitization. On a signal processing

  11. Effects of Different Rainfalls on Run-out Distances and Affected Areas of Debris Flow

    NASA Astrophysics Data System (ADS)

    Lin, Meei-Ling; Chen, Ter-Wei; Lin, Yu-Chung; Chen, Tien-chien; Wang, Kuo-Lung; Huang, Hsiao-Yue; Chen, Mei-Jeng

    2013-04-01

    Taiwan locates at the junction of plate tectonic boundaries with active geologically condition, which results in steep terrains and fragile geological conditions. The heavy rainfall carried by typhoons often causes severe hazard of landslide and debris flow. After Typhoon Morakot, 2009, it was found that the volume of debris transported by the triggered debris flow and its effects on the affected area were much more significant compared to previous case history due to the very large amount of rainfall carried by the Typhoon. In this study, field investigations of 21 debris flow torrents with events triggered by Typhoon Morakot, 2009, were conducted, and the database of debris deposition volume and run-out distance was established. Additional dataset of debris deposition volume and run out distance of debris flow triggered by different typhoons were also collected. Comparisons of the debris deposition volumes by Typhoon Morakot and other typhoons suggested that the high precipitation of Typhoon Morakot caused larger volume of debris transportation. Statistical analysis was performed to determine the correlation of run-out distance and watershed properties. The results suggest that the correlation based on Typhoon Morakot would tend to over-estimate the possible run-out distance of the affected area in most other precipitation condition. Based on the regression analysis of dataset, regression formula of Typhoon Morakot with 50% and 70% of data distribution coverage can be used for determining run-out distance for delineating the affected area, which corresponds to medium and heavy precipitation conditions, respectively. The proposed delineation procedures for the debris flow affected area provide helpful tool for developing delineation map of potential debris flow torrent under effects of different predicted rainfall.

  12. Large Area Microcorrals and Cavity Formation on Cantilevers using a Focused Ion Beam

    SciTech Connect

    Saraf, Laxmikant V.; Britt, David W.

    2011-09-14

    We utilize focused ion beam (FIB) to explore various sputtering parameters to form large area microcorrals and cavities on cantilevers. Microcorrals were rapidly created by modifying ion beam blur and overlaps. Modification in FIB sputtering parameters affects the periodicity and shape of corral microstructure. Cantilever deflections show ion beam amorphization effects as a function of sputtered area and cantilever base cavities with or without side walls. The FIB sputtering parameters address a method for rapid creation of a cantilever tensiometer with integrated fluid storage and delivery.

  13. 40 CFR Table 4 to Subpart Zzzzz of... - Compliance Certifications for New and Existing Affected Sources Classified as Large Iron and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Existing Affected Sources Classified as Large Iron and Steel Foundries 4 Table 4 to Subpart ZZZZZ of Part... Emission Standards for Hazardous Air Pollutants for Iron and Steel Foundries Area Sources Pt. 63, Subpt... Affected Sources Classified as Large Iron and Steel Foundries As required by § 63.10900(b),...

  14. 40 CFR Table 4 to Subpart Zzzzz of... - Compliance Certifications for New and Existing Affected Sources Classified as Large Iron and...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Existing Affected Sources Classified as Large Iron and Steel Foundries 4 Table 4 to Subpart ZZZZZ of Part... Emission Standards for Hazardous Air Pollutants for Iron and Steel Foundries Area Sources Pt. 63, Subpt... Affected Sources Classified as Large Iron and Steel Foundries As required by § 63.10900(b),...

  15. 40 CFR Table 4 to Subpart Zzzzz of... - Compliance Certifications for New and Existing Affected Sources Classified as Large Iron and...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Existing Affected Sources Classified as Large Iron and Steel Foundries 4 Table 4 to Subpart ZZZZZ of Part... Emission Standards for Hazardous Air Pollutants for Iron and Steel Foundries Area Sources Pt. 63, Subpt... Affected Sources Classified as Large Iron and Steel Foundries As required by § 63.10900(b),...

  16. Building ISOC Status Displays for the Large AreaTelescope aboard the Gamma Ray Large Area Space Telescope (GLAST) Observatory

    SciTech Connect

    Ketchum, Christina; /SLAC

    2006-09-01

    In September 2007 the Gamma Ray Large Area Space Telescope (GLAST) is scheduled to launch aboard a Delta II rocket in order to put two high-energy gamma-ray detectors, the Large Area Telescope (LAT) and the GLAST Burst Monitor (GBM) into low earth orbit. The Instrument Science Operations Center (ISOC) at SLAC is responsible for the LAT operations for the duration of the mission, and will therefore build an operations center including a monitoring station at SLAC to inform operations staff and visitors of the status of the LAT instrument and GLAST. This monitoring station is to include sky maps showing the location of GLAST in its orbit as well as the LAT's projected field of view on the sky containing known gamma-ray sources. The display also requires a world map showing the locations of GLAST and three Tracking and Data Relay Satellites (TDRS) relative to the ground, their trail lines, and ''footprint'' circles indicating the range of communications for each satellite. The final display will also include a space view showing the orbiting and pointing information of GLAST and the TDRS satellites. In order to build the displays the astronomy programs Xephem, DS9, SatTrack, and STK were employed to model the position of GLAST and pointing information of the LAT instrument, and the programming utilities Python and Cron were used in Unix to obtain updated information from database and load them into the programs at regular intervals. Through these methods the indicated displays were created and combined to produce a monitoring display for the LAT and GLAST.

  17. [Ecology of syngamosis in a large scale farming area].

    PubMed

    Bejsovec, J

    1976-11-01

    Within recent 20 years, Czechoslovak agriculture has undergone considerable changes due to the introduction of largescale farming. Our contribution presents the results of studies on chickens (Gallus gallus f. dom.) reared traditionally on runs in an area contaminated with the eggs of Syngamus trachea distributed with pheasant faeces. In addition to postmortem examination of 336 chicken tracheae, their faeces collected for one year from the runs were examined, but syngamosis was not found. Studies on small stocks of fowl in gardens close to the fields visited regularly by roosting, Syngamus-infected pheasants disclosed an occasional incidence of syngamosis in the chickens, none in guinea fowl, but frequent infection in young and adult turkeys. Another observation was made on a chicken stock reared inside a pheasantry. Although the incidence of infection of the pheasants with syngamosis was high throughout most of the year, an occasional infection only of the chickens was observed in three months. Postmortem examination of 254 tracheae of free-living birds disclosed that the incidence of syngamosis was highest in the pheasant. - Due to the introduction of large-scale farming, numerous biotopes formerly covered with trees and shrubs, were changed into arrable land. A considerable reduction occurred in the former high stand of partridges (Perdix perdix), while the pheasant (Phasianus colchicus) became widely distributed in agricultural areas. We studied the ecology of the pheasant in various biotopes by means of regular coprological examination without disturbance of the pheasants under consideration. Throughout most of the year the pheasant roosts on trees often growing in moist biotopes. In the morning and evening, the pheasant feeds regularly off the ground close to the roosting trees. From the spring onwards, throughout the summer any autumn, we observed at several sites a marked distribution of pheasants from the trees into the field where they roosted on the

  18. Fermi Large Area Telescope Operations: Progress Over 4 Years

    SciTech Connect

    Cameron, Robert A.; /SLAC

    2012-06-28

    The Fermi Gamma-ray Space Telescope was launched into orbit in June 2008, and is conducting a multi-year gamma-ray all-sky survey, using the main instrument on Fermi, the Large Area Telescope (LAT). Fermi began its science mission in August 2008, and has now been operating for almost 4 years. The SLAC National Accelerator Laboratory hosts the LAT Instrument Science Operations Center (ISOC), which supports the operation of the LAT in conjunction with the Mission Operations Center (MOC) and the Fermi Science Support Center (FSSC), both at NASA's Goddard Space Flight Center. The LAT has a continuous output data rate of about 1.5 Mbits per second, and data from the LAT are stored on Fermi and transmitted to the ground through TDRS and the MOC to the ISOC about 10 times per day. Several hundred computers at SLAC are used to process LAT data to perform event reconstruction, and gamma-ray photon data are subsequently delivered to the FSSC for public release with a few hours of being detected by the LAT. We summarize the current status of the LAT, and the evolution of the data processing and monitoring performed by the ISOC during the first 4 years of the Fermi mission, together with future plans for further changes to detected event data processing and instrument operations and monitoring.

  19. Influence of the Earth's magnetic field on large area photomultipliers

    SciTech Connect

    Leonora, E.; Aiello, S.; Leotta, G.

    2011-07-01

    The influence of the Earth's magnetic field on large area photomultipliers proposed for a future deep sea neutrino telescope was studied under the EU-funded KM3NeT design study. The aims were to evaluate variations in PMT performance in the Earth's magnetic field and to decide whether the use of magnetic shielding is necessary. Measurements were performed on three Hamamatsu PMTs: two 8-inch R5912 types, one of these with super-bi-alkali photocathode, and a 10-inch R7081 type with a standard bi-alkali photocathode. The various characteristics of the PMTs were measured while varying the PMT orientations with respect to the Earth's magnetic field, both with and without a mu-metal cage as magnetic shield. In the 8-inch PMTs the impact of the magnetic field was found to be smaller than that on the 10-inch PMT. The increased quantum efficiency in the 8 super-bi-alkali PMT almost compensated its smaller detection surface compared to the 10' PMT. No significant effects were measured upon transit time and the fraction of spurious pulses. (authors)

  20. Flexible and mechanical strain resistant large area SERS active substrates

    NASA Astrophysics Data System (ADS)

    Singh, J. P.; Chu, Hsiaoyun; Abell, Justin; Tripp, Ralph A.; Zhao, Yiping

    2012-05-01

    We report a cost effective and facile way to synthesize flexible, uniform, and large area surface enhanced Raman scattering (SERS) substrates using an oblique angle deposition (OAD) technique. The flexible SERS substrates consist of 1 μm long, tilted silver nanocolumnar films deposited on flexible polydimethylsiloxane (PDMS) and polyethylene terephthalate (PET) sheets using OAD. The SERS enhancement activity of these flexible substrates was determined using 10-5 M trans-1,2-bis(4-pyridyl) ethylene (BPE) Raman probe molecules. The in situ SERS measurements on these flexible substrates under mechanical (tensile/bending) strain conditions were performed. Our results show that flexible SERS substrates can withstand a tensile strain (ε) value as high as 30% without losing SERS performance, whereas the similar bending strain decreases the SERS performance by about 13%. A cyclic tensile loading test on flexible PDMS SERS substrates at a pre-specified tensile strain (ε) value of 10% shows that the SERS intensity remains almost constant for more than 100 cycles. These disposable and flexible SERS substrates can be integrated with biological substances and offer a novel and practical method to facilitate biosensing applications.

  1. FERMI LARGE AREA TELESCOPE DETECTION OF SUPERNOVA REMNANT RCW 86

    SciTech Connect

    Yuan, Qiang; Huang, Xiaoyuan; Liu, Siming; Zhang, Bing

    2014-04-20

    Using 5.4 yr Fermi Large Area Telescope data, we report the detection of GeV γ-ray emission from the shell-type supernova remnant RCW 86 (G315.4-2.3) with a significance of ∼5.1σ. The data slightly favors an extended emission of this supernova remnant. The spectral index of RCW 86 is found to be very hard, Γ ∼ 1.4, in the 0.4-300 GeV range. A one-zone leptonic model can well fit the multi-wavelength data from radio to very high energy γ-rays. The very hard GeV γ-ray spectrum and the inferred low gas density seem to disfavor a hadronic origin for the γ-rays. The γ-ray behavior of RCW 86 is very similar to several other TeV shell-type supernova remnants, e.g., RX J1713.7-3946, RX J0852.0-4622, SN 1006, and HESS J1731-347.

  2. Saturn: A large area x-ray simulation accelerator

    SciTech Connect

    Bloomquist, D.D.; Stinnett, R.W.; McDaniel, D.H.; Lee, J.R.; Sharpe, A.W.; Halbleib, J.A.; Schlitt, L.G.; Spence, P.W.; Corcoran, P.

    1987-01-01

    Saturn is the result of a major metamorphosis of the Particle Beam Fusion Accelerator-I (PBFA-I) from an ICF research facility to the large-area x-ray source of the Simulation Technology Laboratory (STL) project. Renamed Saturn, for its unique multiple-ring diode design, the facility is designed to take advantage of the numerous advances in pulsed power technology made by the ICF program in recent years and much of the existing PBFA-I support system. Saturn will include significant upgrades in the energy storage and pulse-forming sections. The 36 magnetically insulated transmission lines (MITLs) that provided power flow to the ion diode of PBFA-I were replaced by a system of vertical triplate water transmission lines. These lines are connected to three horizontal triplate disks in a water convolute section. Power will flow through an insulator stack into radial MITLs that drive the three-ring diode. Saturn is designed to operate with a maximum of 750 kJ coupled to the three-ring e-beam diode with a peak power of 25 TW to provide an x-ray exposure capability of 5 x 10/sup 12/ rads/s (Si) and 5 cal/g (Au) over 500 cm/sup 2/.

  3. Large-area nanogap plasmon resonator arrays for plasmonics applications

    NASA Astrophysics Data System (ADS)

    Jin, Mingliang; van Wolferen, Henk; Wormeester, Herbert; van den Berg, Albert; Carlen, Edwin T.

    2012-07-01

    Large-area (~8000 mm2) Au nanogap plasmon resonator array substrates manufactured using maskless laser interference lithography (LIL) with high uniformity are presented. The periodically spaced subwavelength nanogap arrays are formed between adjacent nanopyramid (NPy) structures with precisely defined pitch and high length density (~1 km cm-2), and are ideally suited as scattering sites for surface enhanced Raman scattering (SERS), as well as refractive index sensing. The two-dimensional grid arrangement of NPy structures renders the excitation of the plasmon resonators minimally dependent on the incident polarization. The SERS average enhancement factor (AEF) has been characterized using over 30 000 individual measurements of benzenethiol (BT) chemisorbed on the Au NPy surfaces. From the 1(a1), βCCC + νCS ring mode (1074 cm-1) of BT on surfaces with pitch λg = 200 nm, AEF = 0.8 × 106 and for surfaces with λg = 500 nm, AEF = 0.3 × 107 from over 99% of the imaged spots. Maximum AEFs > 108 have been measured in both cases.

  4. FERMI LARGE AREA TELESCOPE OBSERVATIONS OF THE VELA PULSAR

    SciTech Connect

    Abdo, A. A.; Ackermann, M.; Bartelt, J.; Bechtol, K.; Berenji, B.; Blandford, R. D.; Bloom, E. D.; Bogart, J. R.; Atwood, W. B.; Bagagli, R.; Baldini, L.; Bellardi, F.; Bellazzini, R.; Ballet, J.; Barbiellini, G.; Baring, M. G.; Bastieri, D.; Bisello, D.; Baughman, B. M. E-mail: massimiliano.razzano@pi.infn.it

    2009-05-10

    The Vela pulsar is the brightest persistent source in the GeV sky and thus is the traditional first target for new {gamma}-ray observatories. We report here on initial Fermi Large Area Telescope observations during verification phase pointed exposure and early sky survey scanning. We have used the Vela signal to verify Fermi timing and angular resolution. The high-quality pulse profile, with some 32,400 pulsed photons at E {>=} 0.03 GeV, shows new features, including pulse structure as fine as 0.3 ms and a distinct third peak, which shifts in phase with energy. We examine the high-energy behavior of the pulsed emission; initial spectra suggest a phase-averaged power-law index of {gamma} = 1.51{sup +0.05} {sub -0.04} with an exponential cutoff at E{sub c} = 2.9 {+-} 0.1 GeV. Spectral fits with generalized cutoffs of the form e{sup -(E/E{sub c}){sup b}} require b {<=} 1, which is inconsistent with magnetic pair attenuation, and thus favor outer-magnetosphere emission models. Finally, we report on upper limits to any unpulsed component, as might be associated with a surrounding pulsar wind nebula.

  5. Pulsar Simulations for the Fermi Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Razzano, M.; Harding, A. K.; Baldini, L.; Bellazzini, R.; Bregeon, J.; Burnett, T.; Chiang, J.; Digel, S. W.; Dubois, R.; Kuss, M. W.; Latronico, L.; McEnery, J. E.; Omodei, N.; Pesce-Rollins, M.; Sgro, C.; Spandre, G.; Thompson, D. J.

    2009-01-01

    Pulsars are among the prime targets for the Large Area Telescope (LAT) aboard the recently launched Fermi observatory. The LAT will study the gamma-ray Universe between 20 MeV and 300 GeV with unprecedented detail. Increasing numbers of gamma-ray pulsars are being firmly identified, yet their emission mechanisms are far from being understood. To better investigate and exploit the tAT capabilities for pulsar science. a set of new detailed pulsar simulation tools have been developed within the LAT collaboration. The structure of the pulsar simulator package (PulsarSpeccrum) is presented here. Starting from photon distributions in energy and phase obtained from theoretical calculations or phenomenological considerations, gamma-rays are generated and their arrival times at the spacecraft are determined by taking Into account effects such as barycentric effects and timing noise. Pulsars in binary systems also can be simulated given orbital parameters. We present how simulations can be used for generating a realistic set of gamma rays as observed by the LAT, focusing on some case studies that show the performance of the LAT for pulsar observations.

  6. Fermi Large Area Telescope Detection of Supernova Remnant RCW 86

    NASA Astrophysics Data System (ADS)

    Yuan, Qiang; Huang, Xiaoyuan; Liu, Siming; Zhang, Bing

    2014-04-01

    Using 5.4 yr Fermi Large Area Telescope data, we report the detection of GeV γ-ray emission from the shell-type supernova remnant RCW 86 (G315.4-2.3) with a significance of ~5.1σ. The data slightly favors an extended emission of this supernova remnant. The spectral index of RCW 86 is found to be very hard, Γ ~ 1.4, in the 0.4-300 GeV range. A one-zone leptonic model can well fit the multi-wavelength data from radio to very high energy γ-rays. The very hard GeV γ-ray spectrum and the inferred low gas density seem to disfavor a hadronic origin for the γ-rays. The γ-ray behavior of RCW 86 is very similar to several other TeV shell-type supernova remnants, e.g., RX J1713.7-3946, RX J0852.0-4622, SN 1006, and HESS J1731-347.

  7. DESIGN OF A LARGE-AREA FAST NEUTRON DIRECTIONAL DETECTOR.

    SciTech Connect

    VANIER, P.E.

    2006-10-29

    A large-area fast-neutron double-scatter directional detector and spectrometer is being constructed using l-meter-long plastic scintillator paddles with photomultiplier tubes at both ends. The scintillators detect fast neutrons by proton recoil and also gamma rays by Compton scattering. The paddles are arranged in two parallel planes so that neutrons can be distinguished from muons and gamma rays by time of flight between the planes. The signal pulses are digitized with a time resolution of one gigasample per second. The location of an event along each paddle can be determined from the relative amplitudes or timing of the signals at the ends. The angle of deflection of a neutron in the first plane can be estimated from the energy deposited by the recoil proton, combined with the scattered neutron time-of-flight energy. Each scattering angle can be back-projected as a cone, and many intersecting cones define the incident neutron direction from a distant point source. Moreover, the total energy of each neutron can be obtained, allowing some regions of a fission source spectrum to be distinguished from background generated by cosmic rays. Monte Carlo calculations will be compared with measurements.

  8. Fabrication of large area flexible PDMS waveguide sheets

    NASA Astrophysics Data System (ADS)

    Green, Robert; Knopf, George K.; Bordatchev, Evgueni

    2016-03-01

    Soft-lithography techniques can be used to fabricate mechanically flexible polydimethylsiloxane (PDMS) optical waveguide sheets that act as large area light collectors (concentrators) and illuminators (diffusers). The performance and efficiency of these optical sheets is determined by the position and geometry of micro-optical features embedded in the sheet or imprinted on its surface, thickness and shape of the waveguide, core and cladding refractive indices, and wavelength of the incident light source. The critical design-for-manufacturability parameters are discussed and a scalable method of fabricating multi-layered PDMS optical waveguides is introduced. To illustrate the concepts a prototype waveguide sheet that acts a combined light collector and illumination panel is fabricated and tested. The region of the waveguide sheet that acts as the light collector consists of two superimposed PDMS layers with slightly different indices of refraction. The top layer is patterned with micro-lenses that focus the incident light rays onto the micro-wedge features that act as reflectors on the bottom of the second layer and, due to total internal reflection, redirect the light rays to the light diffuser region of the waveguide sheet. The bottom face of the diffuser PDMS layer is patterned with angled triangular wedge micro-features that project the light out of the waveguide sheet forming an illuminating pattern. The proposed fabrication technique utilizes precision machined polymethylmethacrylate (PMMA) moulds with negative patterned PDMS inserts that transfer the desired micro-optical features onto the moulded waveguide.

  9. Saturn: A large area X-ray simulation accelerator

    NASA Astrophysics Data System (ADS)

    Bloomquist, D. D.; Stinnett, R. W.; McDaniel, D. H.; Lee, J. R.; Sharpe, A. W.; Halbleib, J. A.; Schlitt, L. G.; Spence, P. W.; Corcoran, P.

    1987-06-01

    Saturn is the result of a major metamorphosis of the Particle Beam Fusion Accelerator-I (PBFA-I) from an ICF research facility to the large-area X-ray source of the Simulation Technology Laboratory (STL) project. Renamed Saturn, for its unique multiple-ring diode design, the facility is designed to take advantage of the numerous advances in pulsed power technology. Saturn will include significant upgrades in the energy storage and pulse-forming sections. The 36 magnetically insulated transmission lines (MITLs) that provided power flow to the ion diode of PBFA-I were replaced by a system of vertical triplate water transmission lines. These lines are connected to three horizontal triplate disks in a water convolute section. Power will flow through an insulator stack into radial MITLs that drive the three-ring diode. Saturn is designed to operate with a maximum of 750 kJ coupled to the three-ring e-beam diode with a peak power of 25 TW to provide an X-ray exposure capability of 5 x 10 rads/s (Si) and 5 cal/g (Au) over 500 cm.

  10. Research and Development of Large Area Color AC Plasma Displays

    NASA Astrophysics Data System (ADS)

    Shinoda, Tsutae

    1998-10-01

    Plasma display is essentially a gas discharge device using discharges in small cavities about 0. 1 m. The color plasma displays utilize the visible light from phosphors excited by the ultra-violet by discharge in contrast to monochrome plasma displays utilizing visible light directly from gas discharges. At the early stage of the color plasma display development, the degradation of the phosphors and unstable operating voltage prevented to realize a practical color plasma display. The introduction of the three-electrode surface-discharge technology opened the way to solve the problems. Two key technologies of a simple panel structure with a stripe rib and phosphor alignment and a full color image driving method with an address-and-display-period-separated sub-field method have realized practically available full color plasma displays. A full color plasma display has been firstly developed in 1992 with a 21-in.-diagonal PDP and then a 42-in.-diagonal PDP in 1995 Currently a 50-in.-diagonal color plasma display has been developed. The large area color plasma displays have already been put into the market and are creating new markets, such as a wall hanging TV and multimedia displays for advertisement, information, etc. This paper will show the history of the surface-discharge color plasma display technologies and current status of the color plasma display.

  11. Fabrication of large area nanostructures with surface modified silica spheres

    NASA Astrophysics Data System (ADS)

    Kang, Kwang-Sun

    2014-03-01

    Surface modification of silica spheres with 3-(trimethoxysilyl)propylmethacrylate (TMSPM) has been performed at ambient condition. However, the FTIR spectra and field emission scanning electron microscope (FESEM) images show no evidence of the surface modification. The reaction temperatures were varied from 60 to 80 °C with various reaction periods. Small absorption shoulder of the CO stretching vibration was at 1700 cm-1, and slightly increased with the increase of the reaction time at 60 °C. The clear absorption peak appeared at 1698 cm-1 for the spheres reacted for 80 min at 70 °C and shifted toward 1720 cm-1 with the increase the reaction time. Strong absorption peak showed at 1698 cm-1 and shifted toward 1725 cm-1 with the increase of the reaction time at 80 °C. The spheres were dispersed to methanol and added photoinitiator (Irgacure-184). The solution was poured to a patterned glass substrate and exposed to the 254 nm UV-light during a self-assembly process. A large area and crack-free silica sphere film was formed. To increase the mechanical stability, a cellulose acetate solution was spin-coated to the film. The film was lift-off from the glass substrate to analyze the surface nanostructures. The surface nanostructures were maintained, and the film is stable enough to use as a mold to duplicate the nanopattern and flexible.

  12. Attribution and Characterisation of Sclerophyll Forested Landscapes Over Large Areas

    NASA Astrophysics Data System (ADS)

    Jones, Simon; Soto-Berelov, Mariela; Suarez, Lola; Wilkes, Phil; Woodgate, Will; Haywood, Andrew

    2016-06-01

    This paper presents a methodology for the attribution and characterisation of Sclerophyll forested landscapes over large areas. First we define a set of woody vegetation data primitives (e.g. canopy cover, leaf area index (LAI), bole density, canopy height), which are then scaled-up using multiple remote sensing data sources to characterise and extract landscape woody vegetation features. The advantage of this approach is that vegetation landscape features can be described from composites of these data primitives. The proposed data primitives act as building blocks for the re-creation of past woody characterisation schemes as well as allowing for re-compilation to support present and future policy and management and decision making needs. Three main research sites were attributed; representative of different sclerophyll woody vegetated systems (Box Iron-bark forest; Mountain Ash forest; Mixed Species foothills forest). High resolution hyperspectral and full waveform LiDAR data was acquired over the three research sites. At the same time, land management agencies (Victorian Department of Environment, Land Water and Planning) and researchers (RMIT, CRC for Spatial Information and CSIRO) conducted fieldwork to collect structural and functional measurements of vegetation, using traditional forest mensuration transects and plots, terrestrial lidar scanning and high temporal resolution in-situ autonomous laser (VegNet) scanners. Results are presented of: 1) inter-comparisons of LAI estimations made using ground based hemispherical photography, LAI 2200 PCA, CI-110 and terrestrial and airborne laser scanners; 2) canopy height and vertical canopy complexity derived from airborne LiDAR validated using ground observations; and, 3) time-series characterisation of land cover features. 1. Accuracy targets for remotely sensed LAI products to match within ground based estimates are ± 0.5 LAI or a 20% maximum (CEOS/GCOS) with new aspirational targets of 5%). In this research we

  13. How diversification rates and diversity limits combine to create large-scale species–area relationships

    PubMed Central

    Kisel, Yael; McInnes, Lynsey; Toomey, Nicola H.; Orme, C. David L.

    2011-01-01

    Species–area relationships (SARs) have mostly been treated from an ecological perspective, focusing on immigration, local extinction and resource-based limits to species coexistence. However, a full understanding across large regions is impossible without also considering speciation and global extinction. Rates of both speciation and extinction are known to be strongly affected by area and thus should contribute to spatial patterns of diversity. Here, we explore how variation in diversification rates and ecologically mediated diversity limits among regions of different sizes can result in the formation of SARs. We explain how this area-related variation in diversification can be caused by either the direct effects of area or the effects of factors that are highly correlated with area, such as habitat diversity and population size. We also review environmental, clade-specific and historical factors that affect diversification and diversity limits but are not highly correlated with region area, and thus are likely to cause scatter in observed SARs. We present new analyses using data on the distributions, ages and traits of mammalian species to illustrate these mechanisms; in doing so we provide an integrated perspective on the evolutionary processes shaping SARs. PMID:21807732

  14. An evaluation of supervised classifiers for indirectly detecting salt-affected areas at irrigation scheme level

    NASA Astrophysics Data System (ADS)

    Muller, Sybrand Jacobus; van Niekerk, Adriaan

    2016-07-01

    Soil salinity often leads to reduced crop yield and quality and can render soils barren. Irrigated areas are particularly at risk due to intensive cultivation and secondary salinization caused by waterlogging. Regular monitoring of salt accumulation in irrigation schemes is needed to keep its negative effects under control. The dynamic spatial and temporal characteristics of remote sensing can provide a cost-effective solution for monitoring salt accumulation at irrigation scheme level. This study evaluated a range of pan-fused SPOT-5 derived features (spectral bands, vegetation indices, image textures and image transformations) for classifying salt-affected areas in two distinctly different irrigation schemes in South Africa, namely Vaalharts and Breede River. The relationship between the input features and electro conductivity measurements were investigated using regression modelling (stepwise linear regression, partial least squares regression, curve fit regression modelling) and supervised classification (maximum likelihood, nearest neighbour, decision tree analysis, support vector machine and random forests). Classification and regression trees and random forest were used to select the most important features for differentiating salt-affected and unaffected areas. The results showed that the regression analyses produced weak models (<0.4 R squared). Better results were achieved using the supervised classifiers, but the algorithms tend to over-estimate salt-affected areas. A key finding was that none of the feature sets or classification algorithms stood out as being superior for monitoring salt accumulation at irrigation scheme level. This was attributed to the large variations in the spectral responses of different crops types at different growing stages, coupled with their individual tolerances to saline conditions.

  15. Suppressing geo-facts in landslide-affected areas

    NASA Astrophysics Data System (ADS)

    Sajinkumar, Ks; Pradeepkumar, Ap; Rani, Vr; Di Capua, Giuseppe

    2014-05-01

    The Western Ghats, the bold westerly escarpment of India and which borders the eastern portion of Kerala State (India), bears the testimony of frequent landslides, especially during the monsoon season, and they cause widespread damage to life and property. The natural hazards can turn into disasters in this hilly state, due to the high density of population (~800 per km2). The elements at landslide risk in any area include human population, livestock, land and its resources, environmental values, buildings and economic activities. The loss of lives is the most heart breaking side of the story and cannot be compensated in pecuniary terms. The role of the geoscientist comes into picture to protect the life and property from imminent landslides. But the unbiased role of a geoscientist is blocked by several societal issues like fear of disapproval by the public, political interference, false information propagated through the fourth estate and last but not the least the lack of confidence in her/himself as the profession is now mainly non-societal. This paper aims at looking into these issues in a landslide-prone area of the state. The deontological vs consequential ethical behaviours that characterise the responses by the official machinery and the common man conspire to create disastrous situations, which ultimately brings suffering to the common man, while straining the resources of the state through recurrent payment of damages, every year. The "moral vs monetary" values of society and its government is laid bare in Kerala, especially during landslide disasters and the state's social contract obligations sometimes become ambiguous. Another aspect that has to be addressed is the impact on the marginalized during landslide disasters in Kerala. Does the newly instituted 'Disaster Insurance' scheme adequately cover them? What is the ethical dimensions that such schemes address? The Kerala state is the most socially, educationally, and demographically advanced one in

  16. Testosterone affects language areas of the adult human brain

    PubMed Central

    Hahn, Andreas; Kranz, Georg S.; Sladky, Ronald; Kaufmann, Ulrike; Ganger, Sebastian; Hummer, Allan; Seiger, Rene; Spies, Marie; Vanicek, Thomas; Winkler, Dietmar; Kasper, Siegfried; Windischberger, Christian; Swaab, Dick F.

    2016-01-01

    Abstract Although the sex steroid hormone testosterone is integrally involved in the development of language processing, ethical considerations mostly limit investigations to single hormone administrations. To circumvent this issue we assessed the influence of continuous high‐dose hormone application in adult female‐to‐male transsexuals. Subjects underwent magnetic resonance imaging before and after 4 weeks of testosterone treatment, with each scan including structural, diffusion weighted and functional imaging. Voxel‐based morphometry analysis showed decreased gray matter volume with increasing levels of bioavailable testosterone exclusively in Broca's and Wernicke's areas. Particularly, this may link known sex differences in language performance to the influence of testosterone on relevant brain regions. Using probabilistic tractography, we further observed that longitudinal changes in testosterone negatively predicted changes in mean diffusivity of the corresponding structural connection passing through the extreme capsule. Considering a related increase in myelin staining in rodents, this potentially reflects a strengthening of the fiber tract particularly involved in language comprehension. Finally, functional images at resting‐state were evaluated, showing increased functional connectivity between the two brain regions with increasing testosterone levels. These findings suggest testosterone‐dependent neuroplastic adaptations in adulthood within language‐specific brain regions and connections. Importantly, deteriorations in gray matter volume seem to be compensated by enhancement of corresponding structural and functional connectivity. Hum Brain Mapp 37:1738–1748, 2016. © 2016 Wiley Periodicals, Inc. PMID:26876303

  17. Large-Area Permanent-Magnet ECR Plasma Source

    NASA Technical Reports Server (NTRS)

    Foster, John E.

    2007-01-01

    A 40-cm-diameter plasma device has been developed as a source of ions for material-processing and ion-thruster applications. Like the device described in the immediately preceding article, this device utilizes electron cyclotron resonance (ECR) excited by microwave power in a magnetic field to generate a plasma in an electrodeless (noncontact) manner and without need for an electrically insulating, microwave-transmissive window at the source. Hence, this device offers the same advantages of electrodeless, windowless design - low contamination and long operational life. The device generates a uniform, high-density plasma capable of sustaining uniform ion-current densities at its exit plane while operating at low pressure [<10(exp -4) torr (less than about 1.3 10(exp -2) Pa)] and input power <200 W at a frequency of 2.45 GHz. Though the prototype model operates at 2.45 GHz, operation at higher frequencies can be achieved by straightforward modification to the input microwave waveguide. Higher frequency operation may be desirable in those applications that require even higher background plasma densities. In the design of this ECR plasma source, there are no cumbersome, power-hungry electromagnets. The magnetic field in this device is generated by a permanent-magnet circuit that is optimized to generate resonance surfaces. The microwave power is injected on the centerline of the device. The resulting discharge plasma jumps into a "high mode" when the input power rises above 150 W. This mode is associated with elevated plasma density and high uniformity. The large area and uniformity of the plasma and the low operating pressure are well suited for such material-processing applications as etching and deposition on large silicon wafers. The high exit-plane ion-current density makes it possible to attain a high rate of etching or deposition. The plasma potential is <3 V low enough that there is little likelihood of sputtering, which, in plasma processing, is undesired

  18. Evaluating biodiversity conservation around a large Sumatran protected area.

    PubMed

    Linkie, Matthew; Smith, Robert J; Zhu, Yu; Martyr, Deborah J; Suedmeyer, Beth; Pramono, Joko; Leader-Williams, Nigel

    2008-06-01

    Many of the large, donor-funded community-based conservation projects that seek to reduce biodiversity loss in the tropics have been unsuccessful. There is, therefore, a need for empirical evaluations to identify the driving factors and to provide evidence that supports the development of context-specific conservation projects. We used a quantitative approach to measure, post hoc, the effectiveness of a US$19 million Integrated Conservation and Development Project (ICDP) that sought to reduce biodiversity loss through the development of villages bordering Kerinci Seblat National Park, a UNESCO World Heritage Site in Indonesia. We focused on the success of the ICDP component that disbursed a total of US$1.5 million through development grants to 66 villages in return for their commitment to stop illegally clearing the forest. To investigate whether the ICDP lowered deforestation rates in focal villages, we selected a subset of non-ICDP villages that had similar physical and socioeconomic features and compared their respective deforestation rates. Village participation in the ICDP and its development schemes had no effect on deforestation. Instead, accessible areas where village land-tenure had been undermined by the designation of selective-logging concessions tended to have the highest deforestation rates. Our results indicate that the goal of the ICDP was not met and, furthermore, suggest that both law enforcement inside the park and local property rights outside the park need to be strengthened. Our results also emphasize the importance of quantitative approaches in helping to inform successful and cost-effective strategies for tropical biodiversity conservation. PMID:18336620

  19. A large area cooled-CCD detector for electron microscopy

    NASA Astrophysics Data System (ADS)

    Faruqi, A. R.; Andrews, H. N.; Raeburn, C.

    1994-09-01

    Large area cooled-CCDs are an excellent medium for (indirectly) recording electron images and electron diffraction patterns in real time and for use in electron tomography; real-time imaging is extremely useful in making rapid adjustments in the electron microscope. CCDs provide high sensitivity (useful for minimising dosage to radiation-sensitive biological specimen), good resolution, stable performance, excellent dynamic range and linearity and a reasonably fast readout. We have built an electron imaging device based on the EEV 1152 by 814 pixel CCD which is controlled from a unix based SUN Sparestation operating under X-Windows. The incident 100 kV electrons are converted to visible light in a 0.5 mm thick YAG single crystal which is imaged through a lens on to the CCD. The CCD electronics is designed to be as flexible as possible and allows a wide variation in the readout speed to cater for the relatively fast application where readout noise is less critical and low readout noise applications where the extra few seconds of readout time are not significant. The CCD electronics is built in VME format which is controlled through a S-bus to VME driver. With two parallel channels of readout the whole image can be read out in ˜ 1 s (using the faster readout speed) with 16 bit precision and the image is displayed under X-Windows in a few seconds. The present readout works at 500 kHz and has a noise of ˜ 30 e rms per pixel. With a Peltier cooling device we can operate the CCD at ˜ -40°C which reduces the dark current adequately to allow exposures of up to several minutes. Several examples of patterns collected with the system on a Philips CM12 microscope will be presented.

  20. Evaluating biodiversity conservation around a large Sumatran protected area.

    PubMed

    Linkie, Matthew; Smith, Robert J; Zhu, Yu; Martyr, Deborah J; Suedmeyer, Beth; Pramono, Joko; Leader-Williams, Nigel

    2008-06-01

    Many of the large, donor-funded community-based conservation projects that seek to reduce biodiversity loss in the tropics have been unsuccessful. There is, therefore, a need for empirical evaluations to identify the driving factors and to provide evidence that supports the development of context-specific conservation projects. We used a quantitative approach to measure, post hoc, the effectiveness of a US$19 million Integrated Conservation and Development Project (ICDP) that sought to reduce biodiversity loss through the development of villages bordering Kerinci Seblat National Park, a UNESCO World Heritage Site in Indonesia. We focused on the success of the ICDP component that disbursed a total of US$1.5 million through development grants to 66 villages in return for their commitment to stop illegally clearing the forest. To investigate whether the ICDP lowered deforestation rates in focal villages, we selected a subset of non-ICDP villages that had similar physical and socioeconomic features and compared their respective deforestation rates. Village participation in the ICDP and its development schemes had no effect on deforestation. Instead, accessible areas where village land-tenure had been undermined by the designation of selective-logging concessions tended to have the highest deforestation rates. Our results indicate that the goal of the ICDP was not met and, furthermore, suggest that both law enforcement inside the park and local property rights outside the park need to be strengthened. Our results also emphasize the importance of quantitative approaches in helping to inform successful and cost-effective strategies for tropical biodiversity conservation.

  1. Holistic method for evaluating large area transparent conducting electrodes.

    PubMed

    Gupta, Ritu; Kulkarni, Giridhar U

    2013-02-01

    Nowadays, specifying the quality of a transparent conducting electrode (TCE) using a figure of merit (FoM) is considered nearly mandatory. However, not much attention is paid to the local variations in the FoM itself across the large area of the TCE. This calls for the definition of a local FoM (LFoM), particularly relevant with regard to several new generation TCEs which have been and are being proposed recently. A LFoM based on local measurements of transmission and sheet resistance, pixel by pixel, would be a Herculean task. The present article addresses this central issue by defining a LFoM based on the diffraction efficiency (DE) of a calibrated high-resolution transmission grating overlaid with a given TCE. The DE value, which critically depends on the periodic nature of the grating material, is shown to be highly sensitive to the various nonuniformities in the TCE overlaid on the grating, with length scales comparable to the grating period. The effectiveness of the so-defined LFoM was demonstrated using a pointer laser and a photodiode in combination with a transmission grating with ∼μm periodicity by taking ITO/glass and ITO/PET as case examples. A metal grating pattern of Cu deposited on seed Pd grating lines was fabricated as an example of new generation TCE and examined for FoM and LFoM, however, without the aid of the external grating. The LFoM based on DE presented here should serve as an excellent screening method for both conventional and emerging TCEs.

  2. Solid images generated from UAVs to analyze areas affected by rock falls

    NASA Astrophysics Data System (ADS)

    Giordan, Daniele; Manconi, Andrea; Allasia, Paolo; Baldo, Marco

    2015-04-01

    The study of rock fall affected areas is usually based on the recognition of principal joints families and the localization of potential instable sectors. This requires the acquisition of field data, although as the areas are barely accessible and field inspections are often very dangerous. For this reason, remote sensing systems can be considered as suitable alternative. Recently, Unmanned Aerial Vehicles (UAVs) have been proposed as platform to acquire the necessary information. Indeed, mini UAVs (in particular in the multi-rotors configuration) provide versatility for the acquisition from different points of view a large number of high resolution optical images, which can be used to generate high resolution digital models relevant to the study area. By considering the recent development of powerful user-friendly software and algorithms to process images acquired from UAVs, there is now a need to establish robust methodologies and best-practice guidelines for correct use of 3D models generated in the context of rock fall scenarios. In this work, we show how multi-rotor UAVs can be used to survey areas by rock fall during real emergency contexts. We present two examples of application located in northwestern Italy: the San Germano rock fall (Piemonte region) and the Moneglia rock fall (Liguria region). We acquired data from both terrestrial LiDAR and UAV, in order to compare digital elevation models generated with different remote sensing approaches. We evaluate the volume of the rock falls, identify the areas potentially unstable, and recognize the main joints families. The use on is not so developed but probably this approach can be considered the better solution for a structural investigation of large rock walls. We propose a methodology that jointly considers the Structure from Motion (SfM) approach for the generation of 3D solid images, and a geotechnical analysis for the identification of joint families and potential failure planes.

  3. The Spitzer-HETDEX Exploratory Large-area Survey

    NASA Astrophysics Data System (ADS)

    Papovich, C.; Shipley, H. V.; Mehrtens, N.; Lanham, C.; Lacy, M.; Ciardullo, R.; Finkelstein, S. L.; Bassett, R.; Behroozi, P.; Blanc, G. A.; de Jong, R. S.; DePoy, D. L.; Drory, N.; Gawiser, E.; Gebhardt, K.; Gronwall, C.; Hill, G. J.; Hopp, U.; Jogee, S.; Kawinwanichakij, L.; Marshall, J. L.; McLinden, E.; Mentuch Cooper, E.; Somerville, R. S.; Steinmetz, M.; Tran, K.-V.; Tuttle, S.; Viero, M.; Wechsler, R.; Zeimann, G.

    2016-06-01

    We present post-cryogenic Spitzer imaging at 3.6 and 4.5 μm with the Infrared Array Camera (IRAC) of the Spitzer/HETDEX Exploratory Large-Area (SHELA) survey. SHELA covers ≈24 deg2 of the Sloan Digital Sky Survey “Stripe 82” region, and falls within the footprints of the Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) and the Dark Energy Survey. The HETDEX blind R ˜ 800 spectroscopy will produce ˜200,000 redshifts from the Lyα emission for galaxies in the range 1.9 < z < 3.5, and an additional ˜200,000 redshifts from the [O ii] emission for galaxies at z < 0.5. When combined with deep ugriz images from the Dark Energy Camera, K-band images from NEWFIRM, and other ancillary data, the IRAC photometry from Spitzer will enable a broad range of scientific studies of the relationship between structure formation, galaxy stellar mass, halo mass, the presence of active galactic nuclei, and environment over a co-moving volume of ˜0.5 Gpc3 at 1.9 < z < 3.5. Here, we discuss the properties of the SHELA IRAC data set, including the data acquisition, reduction, validation, and source catalogs. Our tests show that the images and catalogs are 80% (50%) complete to limiting magnitudes of 22.0 (22.6) AB mag in the detection image, which is constructed from the weighted sum of the IRAC 3.6 and 4.5 μm images. The catalogs reach limiting sensitivities of 1.1 μJy at both 3.6 and 4.5 μm (1σ, for R = 2″ circular apertures). As a demonstration of the science, we present IRAC number counts, examples of highly temporally variable sources, and galaxy surface density profiles of rich galaxy clusters. In the spirit of the Spitzer Exploratory programs, we provide all of the images and catalogs as part of the publication.

  4. The Spitzer-HETDEX Exploratory Large-area Survey

    NASA Astrophysics Data System (ADS)

    Papovich, C.; Shipley, H. V.; Mehrtens, N.; Lanham, C.; Lacy, M.; Ciardullo, R.; Finkelstein, S. L.; Bassett, R.; Behroozi, P.; Blanc, G. A.; de Jong, R. S.; DePoy, D. L.; Drory, N.; Gawiser, E.; Gebhardt, K.; Gronwall, C.; Hill, G. J.; Hopp, U.; Jogee, S.; Kawinwanichakij, L.; Marshall, J. L.; McLinden, E.; Mentuch Cooper, E.; Somerville, R. S.; Steinmetz, M.; Tran, K.-V.; Tuttle, S.; Viero, M.; Wechsler, R.; Zeimann, G.

    2016-06-01

    We present post-cryogenic Spitzer imaging at 3.6 and 4.5 μm with the Infrared Array Camera (IRAC) of the Spitzer/HETDEX Exploratory Large-Area (SHELA) survey. SHELA covers ≈24 deg2 of the Sloan Digital Sky Survey “Stripe 82” region, and falls within the footprints of the Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) and the Dark Energy Survey. The HETDEX blind R ˜ 800 spectroscopy will produce ˜200,000 redshifts from the Lyα emission for galaxies in the range 1.9 < z < 3.5, and an additional ˜200,000 redshifts from the [O ii] emission for galaxies at z < 0.5. When combined with deep ugriz images from the Dark Energy Camera, K-band images from NEWFIRM, and other ancillary data, the IRAC photometry from Spitzer will enable a broad range of scientific studies of the relationship between structure formation, galaxy stellar mass, halo mass, the presence of active galactic nuclei, and environment over a co-moving volume of ˜0.5 Gpc3 at 1.9 < z < 3.5. Here, we discuss the properties of the SHELA IRAC data set, including the data acquisition, reduction, validation, and source catalogs. Our tests show that the images and catalogs are 80% (50%) complete to limiting magnitudes of 22.0 (22.6) AB mag in the detection image, which is constructed from the weighted sum of the IRAC 3.6 and 4.5 μm images. The catalogs reach limiting sensitivities of 1.1 μJy at both 3.6 and 4.5 μm (1σ, for R = 2″ circular apertures). As a demonstration of the science, we present IRAC number counts, examples of highly temporally variable sources, and galaxy surface density profiles of rich galaxy clusters. In the spirit of the Spitzer Exploratory programs, we provide all of the images and catalogs as part of the publication.

  5. Rural areas affected by the Chernobyl accident: radiation exposure and remediation strategies.

    PubMed

    Jacob, P; Fesenko, S; Bogdevitch, I; Kashparov, V; Sanzharova, N; Grebenshikova, N; Isamov, N; Lazarev, N; Panov, A; Ulanovsky, A; Zhuchenko, Y; Zhurba, M

    2009-12-15

    Main objectives of the present work were to develop an internationally agreed methodology for deriving optimized remediation strategies in rural areas that are still affected by the Chernobyl accident, and to give an overview of the radiological situation in the three affected countries, Belarus, Russia and Ukraine. Study settlements were defined by having in 2004 less than 10,000 inhabitants and official dose estimates exceeding 1 mSv. Data on population, current farming practices, contamination of soils and foodstuffs, and remedial actions previously applied were collected for each of such 541 study settlements. Calculations of the annual effective dose from internal radiation were validated with extensive data sets on whole body counter measurements. According to our calculations for 2004, in 290 of the study settlements the effective dose exceeded 1 mSv, and the collective dose in these settlements amounted to about 66 person-Sv. Six remedial actions were considered: radical improvement of grassland, application of ferrocyn to cows, feeding pigs with uncontaminated fodder before slaughter, application of mineral fertilizers for potato fields, information campaign on contaminated forest produce, and replacement of contaminated soil in populated areas by uncontaminated soil. Side effects of the remedial actions were quantified by a 'degree of acceptability'. Results are presented for two remediation strategies, namely, Strategy 1, in which the degree of acceptability was given a priority, and Remediation Strategy 2, in which remedial actions were chosen according to lowest costs per averted dose only. Results are highly country-specific varying from preference for soil replacement in populated areas in Belarus to preference for application of ferrocyn to cows in Ukraine. Remedial actions in 2010 can avert a large collective dose of about 150 person-Sv (including averted doses, which would be received in the following years). Nevertheless, the number of

  6. Large area controlled assembly of transparent conductive networks

    DOEpatents

    Ivanov, Ilia N.; Simpson, John T.

    2015-09-29

    A method of preparing a network comprises disposing a solution comprising particulate materials in a solvent onto a superhydrophobic surface comprising a plurality of superhydrophobic features and interfacial areas between the superhydrophobic features. The plurality of superhydrophobic features has a water contact angle of at least about 150.degree.. The method of preparing the network also comprises removing the solvent from the solution of the particulate materials, and forming a network of the particulate materials in the interfacial areas, the particulate materials receding to the interfacial areas as the solvent is removed.

  7. Trajectories of posttraumatic stress symptomatology in older persons affected by a large-magnitude disaster.

    PubMed

    Pietrzak, Robert H; Van Ness, Peter H; Fried, Terri R; Galea, Sandro; Norris, Fran H

    2013-04-01

    This study examined the nature and determinants of longitudinal trajectories of disaster-related posttraumatic stress disorder (PTSD) symptoms in older persons affected by a large-magnitude disaster. Two hundred six adults age 60 or older (mean = 69, range = 60-92) who resided in the Galveston Bay area when Hurricane Ike struck in September 2008 completed telephone interviews an average of 3-, 6-, and 15-months after this disaster. Latent growth mixture modeling was employed to identify predominant trajectories of disaster-related PTSD symptoms over time; and pre-, peri-, and post-disaster determinants of these trajectories were then examined. A 3-class solution optimally characterized PTSD symptom trajectories, with the majority (78.7%) of the sample having low/no PTSD symptoms over all assessments (i.e., resistant); 16.0% having chronically elevated symptoms (i.e., chronic); and 5.3% having a delayed onset course of symptoms (i.e., delayed-onset). Lower education, greater severity of Hurricane Ike exposure (i.e., Ike-related physical illness or injury and high level of community destruction), and greater number of traumatic and stressful life events after Hurricane Ike, particularly financial problems, were associated with a chronic PTSD trajectory. Greater number of traumatic and stressful life events, particularly financial problems after Hurricane Ike, was also associated with a delayed-onset trajectory. These findings suggest that there are heterogeneous trajectories of disaster-related PTSD symptoms in older adults and that these trajectories have common and unique determinants. They also underscore the importance of prevention efforts designed to mitigate the deleterious effects of post-disaster stressors, most notably financial distress, in older persons affected by disasters.

  8. Trajectories of posttraumatic stress symptomatology in older persons affected by a large-magnitude disaster.

    PubMed

    Pietrzak, Robert H; Van Ness, Peter H; Fried, Terri R; Galea, Sandro; Norris, Fran H

    2013-04-01

    This study examined the nature and determinants of longitudinal trajectories of disaster-related posttraumatic stress disorder (PTSD) symptoms in older persons affected by a large-magnitude disaster. Two hundred six adults age 60 or older (mean = 69, range = 60-92) who resided in the Galveston Bay area when Hurricane Ike struck in September 2008 completed telephone interviews an average of 3-, 6-, and 15-months after this disaster. Latent growth mixture modeling was employed to identify predominant trajectories of disaster-related PTSD symptoms over time; and pre-, peri-, and post-disaster determinants of these trajectories were then examined. A 3-class solution optimally characterized PTSD symptom trajectories, with the majority (78.7%) of the sample having low/no PTSD symptoms over all assessments (i.e., resistant); 16.0% having chronically elevated symptoms (i.e., chronic); and 5.3% having a delayed onset course of symptoms (i.e., delayed-onset). Lower education, greater severity of Hurricane Ike exposure (i.e., Ike-related physical illness or injury and high level of community destruction), and greater number of traumatic and stressful life events after Hurricane Ike, particularly financial problems, were associated with a chronic PTSD trajectory. Greater number of traumatic and stressful life events, particularly financial problems after Hurricane Ike, was also associated with a delayed-onset trajectory. These findings suggest that there are heterogeneous trajectories of disaster-related PTSD symptoms in older adults and that these trajectories have common and unique determinants. They also underscore the importance of prevention efforts designed to mitigate the deleterious effects of post-disaster stressors, most notably financial distress, in older persons affected by disasters. PMID:23290559

  9. Regional contraction of brain surface area involves three large-scale networks in schizophrenia.

    PubMed

    Palaniyappan, Lena; Mallikarjun, Pavan; Joseph, Verghese; White, Thomas P; Liddle, Peter F

    2011-07-01

    In schizophrenia, morphological changes in the cerebral cortex have been primarily investigated using volumetric or cortical thickness measurements. In healthy subjects, as the brain size increases, the surface area expands disproportionately when compared to the scaling of cortical thickness. In this structural MRI study, we investigated the changes in brain surface area in schizophrenia by constructing relative areal contraction/expansion maps showing group differences in surface area using Freesurfer software in 57 patients and 41 controls. We observed relative areal contraction affecting Default Mode Network, Central Executive Network and Salience Network, in addition to other regions in schizophrenia. We confirmed the surface area reduction across these three large-scale brain networks by undertaking further region-of-interest analysis of surface area. We also observed a significant hemispheric asymmetry in the surface area changes, with the left hemisphere showing a greater reduction in the areal contraction maps. Our findings suggest that a fundamental disturbance in cortical expansion is likely in individuals who develop schizophrenia. PMID:21497489

  10. Large-scale climatic anomalies affect marine predator foraging behaviour and demography.

    PubMed

    Bost, Charles A; Cotté, Cedric; Terray, Pascal; Barbraud, Christophe; Bon, Cécile; Delord, Karine; Gimenez, Olivier; Handrich, Yves; Naito, Yasuhiko; Guinet, Christophe; Weimerskirch, Henri

    2015-10-27

    Determining the links between the behavioural and population responses of wild species to environmental variations is critical for understanding the impact of climate variability on ecosystems. Using long-term data sets, we show how large-scale climatic anomalies in the Southern Hemisphere affect the foraging behaviour and population dynamics of a key marine predator, the king penguin. When large-scale subtropical dipole events occur simultaneously in both subtropical Southern Indian and Atlantic Oceans, they generate tropical anomalies that shift the foraging zone southward. Consequently the distances that penguins foraged from the colony and their feeding depths increased and the population size decreased. This represents an example of a robust and fast impact of large-scale climatic anomalies affecting a marine predator through changes in its at-sea behaviour and demography, despite lack of information on prey availability. Our results highlight a possible behavioural mechanism through which climate variability may affect population processes.

  11. Large-scale climatic anomalies affect marine predator foraging behaviour and demography

    PubMed Central

    Bost, Charles A.; Cotté, Cedric; Terray, Pascal; Barbraud, Christophe; Bon, Cécile; Delord, Karine; Gimenez, Olivier; Handrich, Yves; Naito, Yasuhiko; Guinet, Christophe; Weimerskirch, Henri

    2015-01-01

    Determining the links between the behavioural and population responses of wild species to environmental variations is critical for understanding the impact of climate variability on ecosystems. Using long-term data sets, we show how large-scale climatic anomalies in the Southern Hemisphere affect the foraging behaviour and population dynamics of a key marine predator, the king penguin. When large-scale subtropical dipole events occur simultaneously in both subtropical Southern Indian and Atlantic Oceans, they generate tropical anomalies that shift the foraging zone southward. Consequently the distances that penguins foraged from the colony and their feeding depths increased and the population size decreased. This represents an example of a robust and fast impact of large-scale climatic anomalies affecting a marine predator through changes in its at-sea behaviour and demography, despite lack of information on prey availability. Our results highlight a possible behavioural mechanism through which climate variability may affect population processes. PMID:26506134

  12. Large-scale climatic anomalies affect marine predator foraging behaviour and demography

    NASA Astrophysics Data System (ADS)

    Bost, Charles A.; Cotté, Cedric; Terray, Pascal; Barbraud, Christophe; Bon, Cécile; Delord, Karine; Gimenez, Olivier; Handrich, Yves; Naito, Yasuhiko; Guinet, Christophe; Weimerskirch, Henri

    2015-10-01

    Determining the links between the behavioural and population responses of wild species to environmental variations is critical for understanding the impact of climate variability on ecosystems. Using long-term data sets, we show how large-scale climatic anomalies in the Southern Hemisphere affect the foraging behaviour and population dynamics of a key marine predator, the king penguin. When large-scale subtropical dipole events occur simultaneously in both subtropical Southern Indian and Atlantic Oceans, they generate tropical anomalies that shift the foraging zone southward. Consequently the distances that penguins foraged from the colony and their feeding depths increased and the population size decreased. This represents an example of a robust and fast impact of large-scale climatic anomalies affecting a marine predator through changes in its at-sea behaviour and demography, despite lack of information on prey availability. Our results highlight a possible behavioural mechanism through which climate variability may affect population processes.

  13. Large-scale climatic anomalies affect marine predator foraging behaviour and demography.

    PubMed

    Bost, Charles A; Cotté, Cedric; Terray, Pascal; Barbraud, Christophe; Bon, Cécile; Delord, Karine; Gimenez, Olivier; Handrich, Yves; Naito, Yasuhiko; Guinet, Christophe; Weimerskirch, Henri

    2015-01-01

    Determining the links between the behavioural and population responses of wild species to environmental variations is critical for understanding the impact of climate variability on ecosystems. Using long-term data sets, we show how large-scale climatic anomalies in the Southern Hemisphere affect the foraging behaviour and population dynamics of a key marine predator, the king penguin. When large-scale subtropical dipole events occur simultaneously in both subtropical Southern Indian and Atlantic Oceans, they generate tropical anomalies that shift the foraging zone southward. Consequently the distances that penguins foraged from the colony and their feeding depths increased and the population size decreased. This represents an example of a robust and fast impact of large-scale climatic anomalies affecting a marine predator through changes in its at-sea behaviour and demography, despite lack of information on prey availability. Our results highlight a possible behavioural mechanism through which climate variability may affect population processes. PMID:26506134

  14. Large-scale brain networks are distinctly affected in right and left mesial temporal lobe epilepsy.

    PubMed

    de Campos, Brunno Machado; Coan, Ana Carolina; Lin Yasuda, Clarissa; Casseb, Raphael Fernandes; Cendes, Fernando

    2016-09-01

    Mesial temporal lobe epilepsy (MTLE) with hippocampus sclerosis (HS) is associated with functional and structural alterations extending beyond the temporal regions and abnormal pattern of brain resting state networks (RSNs) connectivity. We hypothesized that the interaction of large-scale RSNs is differently affected in patients with right- and left-MTLE with HS compared to controls. We aimed to determine and characterize these alterations through the analysis of 12 RSNs, functionally parceled in 70 regions of interest (ROIs), from resting-state functional-MRIs of 99 subjects (52 controls, 26 right- and 21 left-MTLE patients with HS). Image preprocessing and statistical analysis were performed using UF(2) C-toolbox, which provided ROI-wise results for intranetwork and internetwork connectivity. Intranetwork abnormalities were observed in the dorsal default mode network (DMN) in both groups of patients and in the posterior salience network in right-MTLE. Both groups showed abnormal correlation between the dorsal-DMN and the posterior salience, as well as between the dorsal-DMN and the executive-control network. Patients with left-MTLE also showed reduced correlation between the dorsal-DMN and visuospatial network and increased correlation between bilateral thalamus and the posterior salience network. The ipsilateral hippocampus stood out as a central area of abnormalities. Alterations on left-MTLE expressed a low cluster coefficient, whereas the altered connections on right-MTLE showed low cluster coefficient in the DMN but high in the posterior salience regions. Both right- and left-MTLE patients with HS have widespread abnormal interactions of large-scale brain networks; however, all parameters evaluated indicate that left-MTLE has a more intricate bihemispheric dysfunction compared to right-MTLE. Hum Brain Mapp 37:3137-3152, 2016. © 2016 The Authors Human Brain Mapping Published by Wiley Periodicals, Inc.

  15. Large area solar power heliostat array for OSETI

    NASA Astrophysics Data System (ADS)

    Covault, Corbin E.

    2001-08-01

    Current OSETI programs make use of optical telescopes with light collection areas on the order of 10 square meters or less. The small collection area limits the ultimate sensitivity achievable to low-intensity signals. However, solar power facilities such as the National Solar Thermal Test Facility (NSTTF) provide the potential for a much larger collecting area. The NSTTF is operated at by the Department of Energy at Sandia National Laboratories for research in solar power development and testing. The NSTTF site includes over 200 fully steerable mirrors (called heliostats) each providing 37 square meters of collecting area. This facility is currently being used at night for gamma-ray astronomy. The STACEE experiment makes use of 64 heliostats to detect nanosecond flashes of optical Cherenkov light associated with gamma-ray air showers from the top of the atmosphere. The STACEE experiment has been in operation since 1998 and has already detected gamma-rays from the Crab Nebula. In principle, the STACEE experiment can be operated with minor modifications to detect OSETI signals on the ground at a photon density of less than two optical photons per square meter per pulse. We summarize performance results from the STACEE experiment, and we discuss the sensitivity of a hypothetical future STACEE-OSETI experiment with particular attention to potential sources of background.

  16. Large-area, triple junction a-Si alloy production

    SciTech Connect

    Oswald, R.; Jansen, K.; Johnson, B.; Willing, F.; Raquet, J.; Kloss, T.; Morris, J.; Weiss, P.; Yang, L.; Hainsworth, M.C.; Ashenfelter, W.; Stabinsky, B.; Twesme, E.; Chen, L.F.; O'Dowd, J. )

    1994-06-30

    Amorphous silicon alloy based triple junction 0.1 m[sup 2] modules with initial efficiencies greater than 11% have been produced using manufacturing equipment. Scale-up of equipment to process substrates 0.56 m[sup 2] in area is nearly complete.

  17. A new approach to large area microchannel plate manufacture

    NASA Technical Reports Server (NTRS)

    1986-01-01

    Methods of manufacture of twisted single elements as the base for producing microchannel plates (MCP) are discussed. Initial evaluations validated the off-axis channel concept and no technological roadblocks were identified which would prevent fabrication of high gain, high spatial resolution, large format MCP's using this technique. The first MP's have operated at stable gains of 3 million with pulse height resolution superior to results obtained by standard chevron MCP's.

  18. Heat-Pipe Array for Large-Area Cooling

    NASA Technical Reports Server (NTRS)

    Edelstein, F.; Brown, R. F.

    1986-01-01

    High rates of heat transfer anticipated. Prototype evaporative cold plate gathers waste heat from equipment mounted on it. Plate made by welding together flanges of several sections of heat pipe. Since plate separates liquid and vapor phases at inlet and outlet ports, eliminates complexities and uncertainties of two-phase flow in zero gravity. On earth, inlet valve enables plate to operate at relatively-large height differences with other plates in same system.

  19. Rapid fabrication of large area binary polystyrene colloidal crystals

    NASA Astrophysics Data System (ADS)

    Luo, Chun-Li; Yang, Rui-Xia; Yan, Wei-Guo; Zhao, Jian; Yang, Guang-Wu; Jia, Guo-Zhi

    2016-07-01

    Binary colloidal crystals (BCCs) possess great potentials in tuning material and optical properties. In this paper, the combination of interface transferred method and spin-coating method is used to fabricate BCCs with different patterns via controlling the size ratio of small (S) to large (L) colloidal spheres and the spin speeds. It is found that BCCs formed LS2, LS4 and LS6 by changing the size ratio. In addition, there are some new and complicated structures, such as LS12, Janus arrays, formed at the low spin speed. This simple assembly method has potential to allow for the creation of optical metmaterials and the plasmonic structures with chiral optical properties.

  20. Large area spark counter with fine time and position resolution

    SciTech Connect

    Ogawa, A.; Fujiwara, N.; Pestov, Yu.N.; Sugahara, R.

    1984-03-01

    The key properties of spark counters include their capability of precision timing (at the sub 100 ps level) and of measuring the position of the charged particle to high accuracy. At SLAC we have undertaken a program to develop these devices for use in high energy physics experiments involving large detectors. A spark counter of size 1.2 m x 0.1 m has been constructed and has been operating continuously in our test setup for several months. Some details of its construction and its properties as a particle detector are reported. 14 references. (WHK)

  1. Acrolein Microspheres Are Bonded To Large-Area Substrates

    NASA Technical Reports Server (NTRS)

    Rembaum, Alan; Yen, Richard C. K.

    1988-01-01

    Reactive cross-linked microspheres produced under influence of ionizing radiation in aqueous solutions of unsaturated aldehydes, such as acrolein, with sodium dodecyl sulfate. Diameters of spheres depend on concentrations of ingredients. If polystyrene, polymethylmethacrylate, or polypropylene object immersed in solution during irradiation, microspheres become attached to surface. Resulting modified surface has grainy coating with reactivity similar to free microspheres. Aldehyde-substituted-functional microspheres react under mild conditions with number of organic reagents and with most proteins. Microsphere-coated macrospheres or films used to immobilize high concentrations of proteins, enzymes, hormones, viruses, cells, and large number of organic compounds. Applications include separation techniques, clinical diagnostic tests, catalytic processes, and battery separators.

  2. Timeless: A Large Sample Study on the Temporal Robustness of Affective Responses

    PubMed Central

    Postzich, Christopher; Blask, Katarina; Frings, Christian; Walther, Eva

    2016-01-01

    Emotion and its effects on other psychological phenomena are frequently studied by presenting emotional pictures for a short amount of time. However, the duration of exposure strongly differs across paradigms. In order to ensure the comparability of affective response elicitation across those paradigms, it is crucial to empirically validate emotional material not only with regard to the affective dimensions valence and arousal, but also with regard to varying presentation times. Despite this operational necessity for the temporal robustness of emotional material, there is only tentative empirical evidence on this issue. To close this gap, we conducted a large sample study testing for the influence of presentation time on affective response elicitation. Two hundred and forty emotional pictures were presented for either 200 or 1000 ms and were rated by 302 participants on the core affect dimensions valence and arousal. The most important finding was that affective response elicitation was comparable for 200 and 1000 ms presentation times, indicating reliable temporal robustness of affective response elicitation within the supra-liminal spectrum. Yet, a more detailed look on the data showed that presentation time impacted particularly on high arousing negative stimuli. However, because these interaction effects were exceedingly small, they must be interpreted with caution and do not endanger the main finding, namely the quite reliable temporal robustness of affective response elicitation. Results are discussed with regard to the comparability of affective response elicitation across varying paradigms. PMID:27313561

  3. Large Area Dust Detector onboard Solar Power Sail Spacecraft

    NASA Astrophysics Data System (ADS)

    Yano, Hajime

    JAXA is aiming to launch the solar power sail engineering demonstrator to the outer planet region of the solar system like Jupiter and the Jovian Trojan asteroids in 2010's. Its interplanetary cruise is a relevant and rare opportunity to monitor physical properties that may be varied by heliocentric distances continuously such as solar wind, solar magnetosphere and micrometeoroid flux. We have been developing the largest but still light-weight dust detector ever to be onboard deep space probes since 2000. PVDF films of a few to 10's of micron thickness are attached as a small part of the solar sail membrane to count and time hypervelocity impacts by micrometeoroids larger than micron size. The first spaceflight test of this dust detector in the order of 100 cm2 detection area was conducted onboard SSSAT (Solar Sail Satellite) as the M-V sub-payload launched to LEO in September 2006. The second opportunity of this series will be the 4- channel impact sensors onboard Kagayaki nano-satellite as an H-IIA piggyback to be launched in 2008. Actual interplanetary measurements can be achieved by the Small Solar Power Sail Demonstrator that will go inside the orbit of the Earth (1 AU) close to Venus around 2010. On this spacecraft, the 8-channel PVDF sensors of about 1 m2 detection area will be onboard to test this system in the interplanetary operation and to hopefully measure dust flux anisotropy in the trailing edge of the Earth, heliocentric flux variance inside 1 AU, and opportunistic detections of possible cometary dust trails and flux enhancement near Venus. The sensors filter electronic, thermal and vibration noises and record time, peak hold value, and relax duration of signals of micrometeoroid impacts. When the full-size solar power sail mission goes beyond 1 AU passing the main asteroid belt to 5 AU in 2010's, this dust detector system will be onboard in the order of several m2 active area. It will also compare its results with infrared observation of zodiacal

  4. Andean Basins Morphometry: Assesing South American Large Rivers' Source Areas

    NASA Astrophysics Data System (ADS)

    Bean, R. A.; Latrubesse, E. M.

    2014-12-01

    Presently there are no regional-scale morphometric analyses of Andean fluvial basins. Therefore, we created a continental-scale database of these basins. Our data covers over an area 1,000,000 km2 of the Andes, from Venezuela to Argentina. These basins are the source of some of the largest rivers in the world including the Amazon, Orinoco, Parana, and Magdalena. Morphometric parameters including shape factor, relief ratio, longitudinal profiles and different indices of basin elevation were calculated based on the CGIAR SRTM 4.1 DEM (~90 m resolution). FAO Hydrosheds were used to segment the DEM by major catchment and then manually cut at the Andean zone. In the North and Central Andes, this produced over 500,000 subcatchments, which we reduced to 619 by setting minimum catchment area to 100 km2. We then integrate lithologic data from DNPM geologic data. Our results indicate that sedimentary lithologies dominate Central Andean catchments (n=268,k=4), which cover an area 767,00 km2, while the Northern Andean catchments (covering 350,000 km2) are more varied, dominated by volcanics in the Pacific (n=78), a sedimentary (48%) dominant mix in the Caribbean (n=138) and 60% sedimentary in the Amazon-Orinoco subregion catchments (n=138). Elevation averages are smallest in the north Andes and average maximum elevations (6,026 m) in the Argentinian catchments (n=65) of the Central Andes are the highest. Shape factors range from 0.49 to 0.58 in the North and 0.52 to 0.58 in the Central Andes. There are clear differences in all categories between region and subregion, but that difference does not hinge on a single morphometric or geologic parameter. Morphometric parameters at a watershed scale (listed in Table) are analyzed and hydrologic data from gauging stations throughout the Andes (n=100) are used to compare morphometric parameters with lithology and characteristics from the basin hydrograph (peak discharge timing, minimum and maximum discharge, and runoff).

  5. Wearable light management system for light stimulated healing of large area chronic wounds (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Kallweit, David; Mayer, Jan; Fricke, Sören; Schnieper, Marc; Ferrini, Rolando

    2016-03-01

    Chronic wounds represent a significant burden to patients, health care professionals, and health care systems, affecting over 40 million patients and creating costs of approximately 40 billion € annually. We will present a medical device for photo-stimulated wound care based on a wearable large area flexible and disposable light management system consisting of a waveguide with incorporated micro- and nanometer scale optical structures for efficient light in-coupling, waveguiding and homogeneous illumination of large area wounds. The working principle of this innovative device is based on the therapeutic effects of visible light to facilitate the self-healing process of chronic wounds. On the one hand, light exposure in the red (656nm) induces growth of keratinocytes and fibroblasts in deeper layers of the skin. On the other hand, blue light (453nm) is known to have antibacterial effects predominately at the surface layers of the skin. In order to be compliant with medical requirements the system will consist of two elements: a disposable wound dressing with embedded flexible optical waveguides for the light management and illumination of the wound area, and a non-disposable compact module containing the light sources, a controller, a rechargeable battery, and a data transmission unit. In particular, we will report on the developed light management system. Finally, as a proof-of-concept, a demonstrator will be presented and its performances will be reported to demonstrate the potential of this innovative device.

  6. Complex vibration ultrasonic welding systems with large area welding tips.

    PubMed

    Tsujino, Jiromaru; Sano, Tsutomu; Ogata, Hayato; Tanaka, Soichi; Harada, Yoshiki

    2002-05-01

    Vibration and welding characteristics of complex vibration ultrasonic welding systems of 27 and 40 kHz were studied. Complex vibration systems, which have elliptical to circular or rectangular to square locus, are effective for ultrasonic welding of various specimens including the same and different metal specimens, and for direct welding of semiconductor tips and packaging of various electronic devices without solder. The complex vibration systems consist of a one-dimensional longitudinal-torsional vibration converter with slitted part, a stepped horn and a longitudinal vibration transducer as a driving source. The complex vibration welding tips of 27 and 40 kHz have enough area of 6-8 mm square for various welding specimens. Aluminum plate specimens of 0.3-1.0 mm thickness were successfully joined with weld strengths almost equal to aluminum specimen strength, and independent to the specimen direction. Required vibration amplitude of 40 kHz is smaller than that of 27 kHz.

  7. Wide-area ATM networking for large-scale MPPs

    SciTech Connect

    Papadopoulos, P.M.; Geist, G.A. II

    1997-04-01

    This paper presents early experiences with using high-speed ATM interfaces to connect multiple Intel Paragons on both local and wide area networks. The testbed includes the 1024 and 512 node Paragons running the OSF operating system at Oak Ridge National Laboratory and the 1840 node Paragon running the Puma operating system at Sandia National Laboratories. The experimental OC-12 (622 Mbits/sec) interfaces are built by GigaNet and provide a proprietary API for sending AAL-5 encapsulated packets. PVM is used as the massaging infrastructure and significant modifications have been made to use the GigaNet API, operate in the Puma environment, and attain acceptable performance over local networks. These modifications are described along with a discussion of roadblocks to networking MPPs with high-performance interfaces. Our early prototype utilizes approximately 25 percent of an OC-12 circuit and 80 percent of an OC-3 circuit in send plus acknowledgment ping-pong tests.

  8. Large-area sheet task advanced dendritic web growth development

    NASA Technical Reports Server (NTRS)

    Duncan, C. S.; Seidensticker, R. G.; Mchugh, J. P.

    1984-01-01

    The thermal models used for analyzing dendritic web growth and calculating the thermal stress were reexamined to establish the validity limits imposed by the assumptions of the models. Also, the effects of thermal conduction through the gas phase were evaluated and found to be small. New growth designs, both static and dynamic, were generated using the modeling results. Residual stress effects in dendritic web were examined. In the laboratory, new techniques for the control of temperature distributions in three dimensions were developed. A new maximum undeformed web width of 5.8 cm was achieved. A 58% increase in growth velocity of 150 micrometers thickness was achieved with dynamic hardware. The area throughput goals for transient growth of 30 and 35 sq cm/min were exceeded.

  9. LSSA large area silicon sheet task continuous Czochralski process development

    NASA Technical Reports Server (NTRS)

    Rea, S. N.

    1978-01-01

    A Czochralski crystal growing furnace was converted to a continuous growth facility by installation of a premelter to provide molten silicon flow into the primary crucible. The basic furnace is operational and several trial crystals were grown in the batch mode. Numerous premelter configurations were tested both in laboratory-scale equipment as well as in the actual furnace. The best arrangement tested to date is a vertical, cylindrical graphite heater containing small fused silicon test tube liner in which the incoming silicon is melted and flows into the primary crucible. Economic modeling of the continuous Czochralski process indicates that for 10 cm diameter crystal, 100 kg furnace runs of four or five crystals each are near-optimal. Costs tend to asymptote at the 100 kg level so little additional cost improvement occurs at larger runs. For these conditions, crystal cost in equivalent wafer area of around $20/sq m exclusive of polysilicon and slicing was obtained.

  10. Large area spark counters with fine time and position resolution

    SciTech Connect

    Ogawa, A.; Atwood, W.B.; Fujiwara, N.; Pestov, Yu.N.; Sugahara, R.

    1983-10-01

    Spark counters trace their history back over three decades but have been used in only a limited number of experiments. The key properties of these devices include their capability of precision timing (at the sub 100 ps level) and of measuring the position of the charged particle to high accuracy. At SLAC we have undertaken a program to develop these devices for use in high energy physics experiments involving large detectors. A spark counter of size 1.2 m x 0.1 m has been constructed and has been operating continuously in our test setup for several months. In this talk I will discuss some details of its construction and its properties as a particle detector. 14 references.

  11. Large area magnetic micropallet arrays for cell colony sorting.

    PubMed

    Cox-Muranami, Wesley A; Nelson, Edward L; Li, G P; Bachman, Mark

    2016-01-01

    A new micropallet array platform for adherent cell colony sorting has been developed. The platform consisted of thousands of square plastic pallets, 270 μm by 270 μm on each side, large enough to hold a single colony of cells. Each pallet included a magnetic core, allowing them to be collected with a magnet after being released using a microscope mounted laser system. The micropallets were patterned from 1002F epoxy resist and were fabricated on translucent, gold coated microscope slides. The gold layer was used as seed for electroplating the ferromagnetic cores within every individual pallet. The gold layer also facilitated the release of each micropallet during laser release. This array allows for individual observation, sorting and collection of isolated cell colonies for biological cell colony research. In addition to consistent release and recovery of individual colonies, we demonstrated stable biocompatibility and minimal loss in imaging quality compared to previously developed micropallet arrays. PMID:26606460

  12. Large area magnetic micropallet arrays for cell colony sorting.

    PubMed

    Cox-Muranami, Wesley A; Nelson, Edward L; Li, G P; Bachman, Mark

    2016-01-01

    A new micropallet array platform for adherent cell colony sorting has been developed. The platform consisted of thousands of square plastic pallets, 270 μm by 270 μm on each side, large enough to hold a single colony of cells. Each pallet included a magnetic core, allowing them to be collected with a magnet after being released using a microscope mounted laser system. The micropallets were patterned from 1002F epoxy resist and were fabricated on translucent, gold coated microscope slides. The gold layer was used as seed for electroplating the ferromagnetic cores within every individual pallet. The gold layer also facilitated the release of each micropallet during laser release. This array allows for individual observation, sorting and collection of isolated cell colonies for biological cell colony research. In addition to consistent release and recovery of individual colonies, we demonstrated stable biocompatibility and minimal loss in imaging quality compared to previously developed micropallet arrays.

  13. Ultraclean and large-area monolayer hexagonal boron nitride on Cu foil using chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Wen, Yao; Shang, Xunzhong; Dong, Ji; Xu, Kai; He, Jun; Jiang, Chao

    2015-07-01

    Atomically thin hexagonal boron nitride (h-BN) has been demonstrated to be an excellent dielectric layer as well as an ideal van der Waals epitaxial substrate for fabrication of two-dimensional (2D) atomic layers and their vertical heterostructures. Although many groups have obtained large-scale monolayer h-BN through low pressure chemical vapor deposition (LPCVD), it is still a challenge to grow clean monolayers without the reduction of domain size. Here we report the synthesis of large-area (4 × 2 cm2) high quality monolayer h-BN with an ultraclean and unbroken surface on copper foil by using LPCVD. A detailed investigation of the key factors affecting growth and transfer of the monolayer was carried out in order to eliminate the adverse effects of impurity particles. Furthermore, an optimized transfer approach allowed the nondestructive and clean transfer of the monolayer from copper foil onto an arbitrary substrate, including a flexible substrate, under mild conditions. Atomic force microscopy indicated that the root-mean-square (RMS) roughness of the monolayer h-BN on SiO2 was less than 0.269 nm for areas with fewer wrinkles. Selective area electron diffraction analysis of the h-BN revealed a pattern of hexagonal diffraction spots, which unambiguously demonstrated its highly crystalline character. Our work paves the way toward the use of ultraclean and large-area monolayer h-BN as the dielectric layer in the fabrication of high performance electronic and optoelectronic devices for novel 2D atomic layer materials.

  14. Issues in the support and disaster preparedness of severely disabled children in affected areas.

    PubMed

    Tanaka, Soichiro

    2013-03-01

    Relative to their numbers, more than twice the number of disabled children fell victim to the Great East Japan Earthquake than did normal people. It was important to find out needs and provide support, as the needs of disabled children vulnerable to the disaster, such as a shortage of diapers of the right size for disabled children in the affected areas, were not given priority. In addition, the role of coordinators to spread word of who needed what and where, and linking this to specific support, was important. Regions and authorities need to determine how disabled children are to be evacuated in a disaster. Each household should prepare, as disaster prevention measures, their own private power generator and carry medical information for oral or other medicine. Each region should prepare, as a local disaster measure, welfare evacuation areas for disabled children. One thing that was felt acutely in this recent disaster is that disaster preparations and manuals need to be revised from the point of view of welfare, and that the most reliable people were those who, whether as assisters or the assisted, were involved with the disabled on a daily basis from before the disaster. The existence of disabled children as a familiar part of society, and supporting agencies networking based around the children as part of normal operations, plays a very large part. Raising children as part of their local communities is the biggest factor in saving them from disasters.

  15. A large-area RF source for negative hydrogen ions

    NASA Astrophysics Data System (ADS)

    Frank, P.; Feist, J. H.; Kraus, W.; Speth, E.; Heinemann, B.; Probst, F.; Trainham, R.; Jacquot, C.

    1998-08-01

    In a collaboration with CEA Cadarache, IPP is presently developing an rf source, in which the production of negative ions (H-/D-) is being investigated. It utilizes PINI-size rf sources with an external antenna and for the first step a small size extraction system with 48 cm2 net extraction area. First results from BATMAN (Ba¯varian T_est Ma¯chine for N_egative Ions) show (without Cs) a linear dependence of the negative ion yield with rf power, without any sign of saturation. At elevated pressure (1.6 Pa) a current density of 4.5 mA/cm2 H- (without Cs) has been found so far. At medium pressure (0.6 Pa) the current density is lower by approx. a factor of 5, but preliminary results with Cesium injection show a relative increase by almost the same factor in this pressure range. Langmuir probe measurements indicate an electron temperature Te>2 eV close to the plasma grid with a moderate magnetic filter (700 Gcm). Attempts to improve the performance by using different magnetic configurations and different wall materials are under way.

  16. A large-area RF source for negative hydrogen ions

    SciTech Connect

    Frank, P.; Feist, J. H.; Kraus, W.; Speth, E.; Heinemann, B.; Probst, F.; Trainham, R.; Jacquot, C.

    1998-08-20

    In a collaboration with CEA Cadarache, IPP is presently developing an rf source, in which the production of negative ions (H{sup -}/D{sup -}) is being investigated. It utilizes PINI-size rf sources with an external antenna and for the first step a small size extraction system with 48 cm{sup 2} net extraction area. First results from BATMAN (Bavarian T lowbar est Machine for N lowbar egative Ions) show (without Cs) a linear dependence of the negative ion yield with rf power, without any sign of saturation. At elevated pressure (1.6 Pa) a current density of 4.5 mA/cm{sup 2} H{sup -} (without Cs) has been found so far. At medium pressure (0.6 Pa) the current density is lower by approx. a factor of 5, but preliminary results with Cesium injection show a relative increase by almost the same factor in this pressure range. Langmuir probe measurements indicate an electron temperature T{sub e}>2 eV close to the plasma grid with a moderate magnetic filter (700 Gcm). Attempts to improve the performance by using different magnetic configurations and different wall materials are under way.

  17. Performance model for large area solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Klotz, Dino; Schmidt, Jan Philipp; Weber, André; Ivers-Tiffée, Ellen

    2014-08-01

    A parameter set obtained from a 1 cm2 size electrode cell is used to develop and calibrate a one-dimensional spatially resolved model. It is demonstrated that this performance model precalculates the evolving operating parameters along the gas channel of a large-sized cell. Input parameters are: (i) number of discretization elements N, accounting for anodic gas conversion, (ii) anodic gas flow rate and composition and (iv) operating voltage. The model calculations based on data from the 1 cm2 cell are scaled to be equivalent to a larger cell with 16 cm2 electrode size which is used to validate the performance model. The current/voltage characteristics can be predicted very accurately, even when anodic gas flow rates vary by as much as a factor of four. The performance model presented herein simulates the total overvoltage and does so in a broad range of operation conditions. This is done with an accuracy of the simulated current better than 6.1% for UOP = 0.85 V, 3.8% for UOP = 0.8 V and 3.7% for UOP = 0.75 V. It is hoped that these equations will form the basis of a greater model, capable of predicting all the conditions found throughout any industrial stack.

  18. Large-Area Semiconducting Graphene Nanomesh Tailored by Interferometric Lithography

    PubMed Central

    Kazemi, Alireza; He, Xiang; Alaie, Seyedhamidreza; Ghasemi, Javad; Dawson, Noel Mayur; Cavallo, Francesca; Habteyes, Terefe G.; Brueck, Steven R. J.; Krishna, Sanjay

    2015-01-01

    Graphene nanostructures are attracting a great deal of interest because of newly emerging properties originating from quantum confinement effects. We report on using interferometric lithography to fabricate uniform, chip-scale, semiconducting graphene nanomesh (GNM) with sub-10 nm neck widths (smallest edge-to-edge distance between two nanoholes). This approach is based on fast, low-cost, and high-yield lithographic technologies and demonstrates the feasibility of cost-effective development of large-scale semiconducting graphene sheets and devices. The GNM is estimated to have a room temperature energy bandgap of ~30 meV. Raman studies showed that the G band of the GNM experiences a blue shift and broadening compared to pristine graphene, a change which was attributed to quantum confinement and localization effects. A single-layer GNM field effect transistor exhibited promising drive current of ~3.9 μA/μm and ON/OFF current ratios of ~35 at room temperature. The ON/OFF current ratio of the GNM-device displayed distinct temperature dependence with about 24-fold enhancement at 77 K. PMID:26126936

  19. The Incidence of Dwarf Novae in Large Area Transient Searches

    NASA Astrophysics Data System (ADS)

    Rau, A.; Schwarz, R.; Kulkarni, S. R.; Ofek, E. O.; Kasliwal, M. M.; Brinkworth, C.; Cenko, S. B.; Lipkin, Y.; Soderberg, A. M.

    2007-07-01

    Understanding and quantifying the contribution of known classes of transient and variable sources is an important lesson to be learned from the manifold of precursor programs of the near-future large synoptic sky survey programs such as SkyMapper, Pan-STARRS, and LSST. With this goal in mind, we undertook photometric and spectroscopic follow-up observations of four recently reported unidentified transients. For two sources, WFI J132813.7-214237 and WFI J161953.3+031909, we show that unfortunate coincidences led to their previous designation as transients. While the former is now interpreted as the spatial coincidence of a solar system object with a faint background star, the latter is merely a cataclysmic variable unfortunately caught in and out of eclipse. The third candidate, ROTSE3 J160213.1-021311.7, is identified as an SU UMa type dwarf nova with quiescent brightness of R~22.7 and an outburst amplitude of ~5 mag. The fourth event, SDSS-SN 15207, similarly shows evidence for a dwarf nova origin. Our main conclusion is that cataclysmic variables in their various avatars will contribute moderately to the population of transient objects.

  20. A new large area lanthanum hexaboride plasma source

    NASA Astrophysics Data System (ADS)

    Cooper, C. M.; Gekelman, W.; Pribyl, P.; Lucky, Z.

    2010-08-01

    A new 18×18 cm2 active area lanthanum hexaboride (LaB6) plasma source for use in a dc discharge has been developed at UCLA. The cathode consists of four tiled LaB6 pieces indirectly heated to electron emission (1750 °C) by a graphite heater. A molybdenum mesh anode 33 cm in front of the LaB6 accelerates the electrons, ionizing a fill gas to create a 20×20 cm2 nearly square plasma. The source is run in pulsed operation with the anode biased up to +400 V dc with respect to the cathode for up to 100 ms at a 1 Hz repetition rate. Both the cathode and anode "float" electrically with respect to the chamber walls. The source is placed in a toroidal chamber 2 m wide and 3 m tall with a major radius of 5 m. Toroidal and vertical magnetic fields confine the current-free plasma which follows the field in a helix. The plasma starts on the bottom of the machine and spirals around it up to four times (120 m) and can be configured to terminate either on the top wall or on the neutral gas itself. The source typically operates with a discharge current up to 250 A in helium making plasmas with Te<30 eV, Ti<16 eV, and ne<3×1013 cm-3 in a background field of 100 G

  1. A new large area lanthanum hexaboride plasma source

    SciTech Connect

    Cooper, C. M.; Gekelman, W.; Pribyl, P.; Lucky, Z.

    2010-08-15

    A new 18x18 cm{sup 2} active area lanthanum hexaboride (LaB{sub 6}) plasma source for use in a dc discharge has been developed at UCLA. The cathode consists of four tiled LaB{sub 6} pieces indirectly heated to electron emission (1750 deg. C) by a graphite heater. A molybdenum mesh anode 33 cm in front of the LaB{sub 6} accelerates the electrons, ionizing a fill gas to create a 20x20 cm{sup 2} nearly square plasma. The source is run in pulsed operation with the anode biased up to +400 V dc with respect to the cathode for up to 100 ms at a 1 Hz repetition rate. Both the cathode and anode ''float'' electrically with respect to the chamber walls. The source is placed in a toroidal chamber 2 m wide and 3 m tall with a major radius of 5 m. Toroidal and vertical magnetic fields confine the current-free plasma which follows the field in a helix. The plasma starts on the bottom of the machine and spirals around it up to four times (120 m) and can be configured to terminate either on the top wall or on the neutral gas itself. The source typically operates with a discharge current up to 250 A in helium making plasmas with T{sub e}<30 eV, T{sub i}<16 eV, and n{sub e}<3x10{sup 13} cm{sup -3} in a background field of 100 G

  2. A large area, silicon photomultiplier-based PET detector module

    NASA Astrophysics Data System (ADS)

    Raylman, R. R.; Stolin, A.; Majewski, S.; Proffitt, J.

    2014-01-01

    The introduction of silicon photomultipliers (SiPM) has facilitated construction of compact, efficient and magnetic field-hardened positron emission tomography (PET) scanners. To take full advantage of these devices, methods for using them to produce large field-of-view PET scanners are needed. In this investigation, we explored techniques to combine two SiPM arrays to form the building block for a small animal PET scanner. The module consists of a 26×58 array of 1.5×1.5 mm2 LYSO elements (spanning 41×91 mm2) coupled to two SensL SiPM arrays. The SiPMs were read out with new multiplexing electronics developed for this project. To facilitate calculation of event position with multiple SiPM arrays it was necessary to spread scintillation light amongst a number of elements with a small light guide. This method was successful in permitting identification of all detector elements, even at the seam between two SiPM arrays. Since the performance of SiPMs is enhanced by cooling, the detector module was fitted with a cooling jacket, which allowed the temperature of the device and electronics to be controlled. Testing demonstrated that the peak-to-valley contrast ratio of the light detected from the scintillation array was increased by ~45% when the temperature was reduced from 28 °C to 16 °C. Energy resolution for 511 keV photons improved slightly from 18.8% at 28 °C to 17.8% at 16 °C. Finally, the coincidence timing resolution of the module was found to be insufficient for time-of-flight applications (~2100 ps at 14 °C). The first use of these new modules will be in the construction of a small animal PET scanner to be integrated with a 3 T clinical magnetic resonance imaging scanner.

  3. A large area, silicon photomultiplier-based PET detector module.

    PubMed

    Raylman, Rr; Stolin, A; Majewski, S; Proffitt, J

    2014-01-21

    The introduction of silicon photomultipliers (SiPM) has facilitated construction of compact, efficient and magnetic field-hardened positron emission tomography (PET) scanners. To take full advantage of these devices, methods for using them to produce large field-of-view PET scanners are needed. In this investigation, we explored techniques to combine two SiPM arrays to form the building block for a small animal PET scanner. The module consists of a 26 × 58 array of 1.5 × 1.5mm(2) LYSO elements (spanning 41 × 91mm(2)) coupled to two SensL SiPM arrays. The SiPMs were read out with new multiplexing electronics developed for this project. To facilitate calculation of event position with multiple SiPM arrays it was necessary to spread scintillation light amongst a number of elements with a small light guide. This method was successful in permitting identification of all detector elements, even at the seam between two SiPM arrays. Since the performance of SiPMs is enhanced by cooling, the detector module was fitted with a cooling jacket, which allowed the temperature of the device and electronics to be controlled. Testing demonstrated that the peak-to-valley contrast ratio of the light detected from the scintillation array was increased by ∼45% when the temperature was reduced from 28 °C to 16 °C. Energy resolution for 511 keV photons improved slightly from 18.8% at 28 °C to 17.8% at 16 °C. Finally, the coincidence timing resolution of the module was found to be insufficient for time-of-flight applications (∼2100 ps at 14 °C). The first use of these new modules will be in the construction of a small animal PET scanner to be integrated with a 3T clinical magnetic resonance imaging scanner. PMID:24319305

  4. A large area, silicon photomultiplier-based PET detector module.

    PubMed

    Raylman, Rr; Stolin, A; Majewski, S; Proffitt, J

    2014-01-21

    The introduction of silicon photomultipliers (SiPM) has facilitated construction of compact, efficient and magnetic field-hardened positron emission tomography (PET) scanners. To take full advantage of these devices, methods for using them to produce large field-of-view PET scanners are needed. In this investigation, we explored techniques to combine two SiPM arrays to form the building block for a small animal PET scanner. The module consists of a 26 × 58 array of 1.5 × 1.5mm(2) LYSO elements (spanning 41 × 91mm(2)) coupled to two SensL SiPM arrays. The SiPMs were read out with new multiplexing electronics developed for this project. To facilitate calculation of event position with multiple SiPM arrays it was necessary to spread scintillation light amongst a number of elements with a small light guide. This method was successful in permitting identification of all detector elements, even at the seam between two SiPM arrays. Since the performance of SiPMs is enhanced by cooling, the detector module was fitted with a cooling jacket, which allowed the temperature of the device and electronics to be controlled. Testing demonstrated that the peak-to-valley contrast ratio of the light detected from the scintillation array was increased by ∼45% when the temperature was reduced from 28 °C to 16 °C. Energy resolution for 511 keV photons improved slightly from 18.8% at 28 °C to 17.8% at 16 °C. Finally, the coincidence timing resolution of the module was found to be insufficient for time-of-flight applications (∼2100 ps at 14 °C). The first use of these new modules will be in the construction of a small animal PET scanner to be integrated with a 3T clinical magnetic resonance imaging scanner.

  5. Long-period ocean-bottom motions in the source areas of large subduction earthquakes.

    PubMed

    Nakamura, Takeshi; Takenaka, Hiroshi; Okamoto, Taro; Ohori, Michihiro; Tsuboi, Seiji

    2015-01-01

    Long-period ground motions in plain and basin areas on land can cause large-scale, severe damage to structures and buildings and have been widely investigated for disaster prevention and mitigation. However, such motions in ocean-bottom areas are poorly studied because of their relative insignificance in uninhabited areas and the lack of ocean-bottom strong-motion data. Here, we report on evidence for the development of long-period (10-20 s) motions using deep ocean-bottom data. The waveforms and spectrograms demonstrate prolonged and amplified motions that are inconsistent with attenuation patterns of ground motions on land. Simulated waveforms reproducing observed ocean-bottom data demonstrate substantial contributions of thick low-velocity sediment layers to development of these motions. This development, which could affect magnitude estimates and finite fault slip modelling because of its critical period ranges on their estimations, may be common in the source areas of subduction earthquakes where thick, low-velocity sediment layers are present.

  6. Long-period ocean-bottom motions in the source areas of large subduction earthquakes

    PubMed Central

    Nakamura, Takeshi; Takenaka, Hiroshi; Okamoto, Taro; Ohori, Michihiro; Tsuboi, Seiji

    2015-01-01

    Long-period ground motions in plain and basin areas on land can cause large-scale, severe damage to structures and buildings and have been widely investigated for disaster prevention and mitigation. However, such motions in ocean-bottom areas are poorly studied because of their relative insignificance in uninhabited areas and the lack of ocean-bottom strong-motion data. Here, we report on evidence for the development of long-period (10–20 s) motions using deep ocean-bottom data. The waveforms and spectrograms demonstrate prolonged and amplified motions that are inconsistent with attenuation patterns of ground motions on land. Simulated waveforms reproducing observed ocean-bottom data demonstrate substantial contributions of thick low-velocity sediment layers to development of these motions. This development, which could affect magnitude estimates and finite fault slip modelling because of its critical period ranges on their estimations, may be common in the source areas of subduction earthquakes where thick, low-velocity sediment layers are present. PMID:26617193

  7. Evaluation of geochemical and hydrogeological processes by geochemical modeling in an area affected by evaporite karstification

    NASA Astrophysics Data System (ADS)

    Acero, P.; Auqué, L. F.; Galve, J. P.; Gutiérrez, F.; Carbonel, D.; Gimeno, M. J.; Yechieli, Y.; Asta, M. P.; Gómez, J. B.

    2015-10-01

    The Ebro Valley in the outskirts of Zaragoza (NE Spain) is severely affected by evaporite karstification, leading to multiple problems related to subsidence and sinkhole formation. In this work, a combination of inverse (mixing + mass-balance) and forward (reaction-path) geochemical calculations is applied for the quantification of the main karstification processes and seasonal variations in this area. The obtained results prove the suitability of the applied methodology for the characterization of similar problems in other areas with scarce geological and hydrogeological information. The hydrogeology and hydrochemistry of the system can be mainly attributed to the mixing of variable proportions of concentrated groundwater from the evaporitic aquifer and more dilute water from the overlying alluvial aquifer. The existence of a good connection between these aquifers is supported by: (1) the fast changes in the hydrochemistry of the karst aquifer related to recharge by irrigation, and (2) the deduced input of evaporitic groundwater in the alluvial materials. The evolution in some parts of the alluvial/evaporitic aquifer system is clearly dominated by the seasonal variations in the recharge by dilute irrigation waters (up to 95% of water volume in some sinkhole ponds), whereas other points seem to be clearly determined by the hydrochemistry of the concentrated evaporitic aquifer groundwater (up to 50% of the water volume in some springs). The following reactions, previous or superimposed to mixing processes, explain the observed hydrochemistry in the studied area: dissolution of halite (NaCl), gypsum (CaSO4ṡ2H2O)/anhydrite (CaSO4) and dolomite (CaMg(CO3)2), CO2(g) input and degassing and calcite (CaCO3) dissolution/precipitation. The modeling results suggest the existence of a large spatial variability in the composition of the evaporitic groundwater, mainly caused by large differences in the availability of halite in contact with the groundwater. Active subsidence

  8. Large rainfall changes consistently projected over substantial areas of tropical land

    NASA Astrophysics Data System (ADS)

    Chadwick, Robin; Good, Peter; Martin, Gill; Rowell, David P.

    2016-02-01

    Many tropical countries are exceptionally vulnerable to changes in rainfall patterns, with floods or droughts often severely affecting human life and health, food and water supplies, ecosystems and infrastructure. There is widespread disagreement among climate model projections of how and where rainfall will change over tropical land at the regional scales relevant to impacts, with different models predicting the position of current tropical wet and dry regions to shift in different ways. Here we show that despite uncertainty in the location of future rainfall shifts, climate models consistently project that large rainfall changes will occur for a considerable proportion of tropical land over the twenty-first century. The area of semi-arid land affected by large changes under a higher emissions scenario is likely to be greater than during even the most extreme regional wet or dry periods of the twentieth century, such as the Sahel drought of the late 1960s to 1990s. Substantial changes are projected to occur by mid-century--earlier than previously expected--and to intensify in line with global temperature rise. Therefore, current climate projections contain quantitative, decision-relevant information on future regional rainfall changes, particularly with regard to climate change mitigation policy.

  9. The geomorphological features of a large scale deep-seated landslide in the Luchang area, Taiwan

    NASA Astrophysics Data System (ADS)

    Huang, Ming-Wan; Liao, Jyh-Jong; Pan, Yii-Wen

    2016-04-01

    Landslides events are frequently induced by high-intensity precipitation and active tectonic in Taiwan. Several catastrophic deep-seated landslides have been occurred in past few decades. The pre-existing landslides are the potential sites to occur again. The geomorphology features could provide their important information in reflection of landslide activity. The large scale deep-seated landslide of Luchang locates in the mountain area of Miaoli County, west-northern Taiwan. The site is about 60 hectares in area and from west to east is comprised of a ridge (El. 1100~950 m), main scarp, terrace (El. 925~900 m), hilly slope (El. 900~700 m), and the Luchang River. The regional geology is mainly the middle Miocene sedimentary rock which composed of thick sandstone, interlayered sandstone and shale, and coal. The major structures include the Luchang fault and the Shibi anticline, which the location of the former is approximately coincidental to the Luchang River and the latter is approximately coincidental to the ridge. In this study, we identify the geomorphology features by viewing stereo pairs of aerial photographs and examine in the field. UAV (Unmanned Aerial Vehicle) is adopted to assist in unreachable area. Several clear topographic features including scarps, anti-slopes, bulges, etc. are observed in this site. Active bedrock incision has caused many slope collapsed in the Luchang River, which could possibly be the important factors affecting the stability of this site. We also compared the topographic changes through the chronological aerial photographs. The topographic changes likely include several small-scale landslides. The preliminary evolution model of the large scale landslide is proposed in this study. The results help us to evaluate the recurrence potential of a large scale deep-seated landslide.

  10. Investigation of large-area multicoil inductively coupled plasma sources using three-dimensional fluid model

    NASA Astrophysics Data System (ADS)

    Brcka, Jozef

    2016-07-01

    A multi inductively coupled plasma (ICP) system can be used to maintain the plasma uniformity and increase the area processed by a high-density plasma. This article presents a source in two different configurations. The distributed planar multi ICP (DM-ICP) source comprises individual ICP sources that are not overlapped and produce plasma independently. Mutual coupling of the ICPs may affect the distribution of the produced plasma. The integrated multicoil ICP (IMC-ICP) source consists of four low-inductance ICP antennas that are superimposed in an azimuthal manner. The identical geometry of the ICP coils was assumed in this work. Both configurations have highly asymmetric components. A three-dimensional (3D) plasma model of the multicoil ICP configurations with asymmetric features is used to investigate the plasma characteristics in a large chamber and the operation of the sources in inert and reactive gases. The feasibility of the computational calculation, the speed, and the computational resources of the coupled multiphysics solver are investigated in the framework of a large realistic geometry and complex reaction processes. It was determined that additional variables can be used to control large-area plasmas. Both configurations can form a plasma, that azimuthally moves in a controlled manner, the so-called “sweeping mode” (SM) or “polyphase mode” (PPM), and thus they have the potential for large-area and high-density plasma applications. The operation in the azimuthal mode has the potential to adjust the plasma distribution, the reaction chemistry, and increase or modulate the production of the radicals. The intrinsic asymmetry of the individual coils and their combined operation were investigated within a source assembly primarily in argon and CO gases. Limited investigations were also performed on operation in CH4 gas. The plasma parameters and the resulting chemistry are affected by the geometrical relation between individual antennas. The aim of

  11. Crop identification and area estimation over large geographic areas using LANDSAT MSS data

    NASA Technical Reports Server (NTRS)

    Bauer, M. E. (Principal Investigator)

    1977-01-01

    The author has identified the following significant results. LANDSAT MSS data was adequate to accurately identify wheat in Kansas; corn and soybean estimates in Indiana were less accurate. Computer-aided analysis techniques were effectively used to extract crop identification information from LANDSAT data. Systematic sampling of entire counties made possible by computer classification methods resulted in very precise area estimates at county, district, and state levels. Training statistics were successfully extended from one county to other counties having similar crops and soils if the training areas sampled the total variation of the area to be classified.

  12. Rapid health assessments of evacuation centres in areas affected by Typhoon Haiyan

    PubMed Central

    de los Reyes, Vikki Carr; Sucaldito, Ma Nemia; Tayag, Enrique

    2015-01-01

    Introduction Typhoon Haiyan caused thousands of deaths and catastrophic destruction, leaving many homeless in Region 8 of the Philippines. A team from the Philippine Field Epidemiology Training Program conducted a rapid health assessment survey of evacuation centres severely affected by Haiyan. Methods A descriptive study was conducted whereby a convenience sample of evacuation centres were assessed on the number of toilets per evacuee, sanitation, drinking-water, food supply source and medical services. Results Of the 20 evacuation centres assessed, none had a designated manager. Most were located in schools (70%) with the estimated number of evacuees ranging from 15 to 5000 per centre. Only four (20%) met the World Health Organization standard for number of toilets per evacuee; none of the large evacuation centres had even half the recommended number of toilets. All of the evacuation centres had available drinking-water. None of the evacuation centres had garbage collection, vector control activities or standby medical teams. Fourteen (70%) evacuation centres had onsite vaccination activities for measles, tetanus and polio virus. Many evacuation centres were overcrowded. Conclusion Evacuation centres are needed in almost every disaster. They should be safely located and equipped with the required amenities. In disaster-prone areas such as the Philippines, schools and community centres should not be designated as evacuation centres unless they are equipped with adequate sanitation services. PMID:26767134

  13. Environmental factors affecting large-bodied coral reef fish assemblages in the Mariana Archipelago.

    PubMed

    Richards, Benjamin L; Williams, Ivor D; Vetter, Oliver J; Williams, Gareth J

    2012-01-01

    Large-bodied reef fishes represent an economically and ecologically important segment of the coral reef fish assemblage. Many of these individuals supply the bulk of the reproductive output for their population and have a disproportionate effect on their environment (e.g. as apex predators or bioeroding herbivores). Large-bodied reef fishes also tend to be at greatest risk of overfishing, and their loss can result in a myriad of either cascading (direct) or indirect trophic and other effects. While many studies have investigated habitat characteristics affecting populations of small-bodied reef fishes, few have explored the relationship between large-bodied species and their environment. Here, we describe the distribution of the large-bodied reef fishes in the Mariana Archipelago with an emphasis on the environmental factors associated with their distribution. Of the factors considered in this study, a negative association with human population density showed the highest relative influence on the distribution of large-bodied reef fishes; however, depth, water temperature, and distance to deep water also were important. These findings provide new information on the ecology of large-bodied reef fishes can inform discussions concerning essential fish habitat and ecosystem-based management for these species and highlight important knowledge gaps worthy of additional research.

  14. Environmental Factors Affecting Large-Bodied Coral Reef Fish Assemblages in the Mariana Archipelago

    PubMed Central

    Richards, Benjamin L.; Williams, Ivor D.; Vetter, Oliver J.; Williams, Gareth J.

    2012-01-01

    Large-bodied reef fishes represent an economically and ecologically important segment of the coral reef fish assemblage. Many of these individuals supply the bulk of the reproductive output for their population and have a disproportionate effect on their environment (e.g. as apex predators or bioeroding herbivores). Large-bodied reef fishes also tend to be at greatest risk of overfishing, and their loss can result in a myriad of either cascading (direct) or indirect trophic and other effects. While many studies have investigated habitat characteristics affecting populations of small-bodied reef fishes, few have explored the relationship between large-bodied species and their environment. Here, we describe the distribution of the large-bodied reef fishes in the Mariana Archipelago with an emphasis on the environmental factors associated with their distribution. Of the factors considered in this study, a negative association with human population density showed the highest relative influence on the distribution of large-bodied reef fishes; however, depth, water temperature, and distance to deep water also were important. These findings provide new information on the ecology of large-bodied reef fishes can inform discussions concerning essential fish habitat and ecosystem-based management for these species and highlight important knowledge gaps worthy of additional research. PMID:22384014

  15. Survey of arsenic in food composites from an arsenic-affected area of West Bengal, India.

    PubMed

    Roychowdhury, T; Uchino, T; Tokunaga, H; Ando, M

    2002-11-01

    An investigation of total arsenic in food composites, collected from the villagers, was carried out in arsenic-affected areas of the Murshidabad district, West Bengal where the agricultural system is mostly groundwater dependent. The shallow, large-diameter tubewells installed for agricultural irrigation contain an appreciable amount of arsenic (mean 0.085 mg/l, n=6). Even the soil is arsenic-contaminated (mean 11.35 mg/kg, n=36), so some arsenic can be expected in the food chain from crops cultivated in this area. The results revealed that the individual food composite and food groups containing the highest mean arsenic concentrations (microg/kg) are potato skin (292.62 and 104), leaf of vegetables (212.34 and 294.67), arum leaf (331 and 341), papaya (196.50 and 373), rice (226.18 and 245.39), wheat (7 and 362), cumin (47.86 and 209.75), turmeric powder (297.33 and 280.9), cereals and bakery goods (156.37 and 294.47), vegetables (91.73 and 123.22), spices (92.22 and 207.60) and miscellaneous items (138.37 and 137.80) for the Jalangi and Domkal blocks, respectively. Arsenic is absorbed by the skin of most of the vegetables. The arsenic concentration in fleshy vegetable material is low (mean 2.72 microg/kg, n=45). Higher levels of arsenic were observed in cooked items compared with raw. Daily dietary intakes of arsenic (microg) from the foodstuffs for adults are 171.20 and 189.13 and for children are 91.89 and 101.63 in the Jalangi and Domkal blocks, respectively.

  16. Survey of arsenic in food composites from an arsenic-affected area of West Bengal, India.

    PubMed

    Roychowdhury, T; Uchino, T; Tokunaga, H; Ando, M

    2002-11-01

    An investigation of total arsenic in food composites, collected from the villagers, was carried out in arsenic-affected areas of the Murshidabad district, West Bengal where the agricultural system is mostly groundwater dependent. The shallow, large-diameter tubewells installed for agricultural irrigation contain an appreciable amount of arsenic (mean 0.085 mg/l, n=6). Even the soil is arsenic-contaminated (mean 11.35 mg/kg, n=36), so some arsenic can be expected in the food chain from crops cultivated in this area. The results revealed that the individual food composite and food groups containing the highest mean arsenic concentrations (microg/kg) are potato skin (292.62 and 104), leaf of vegetables (212.34 and 294.67), arum leaf (331 and 341), papaya (196.50 and 373), rice (226.18 and 245.39), wheat (7 and 362), cumin (47.86 and 209.75), turmeric powder (297.33 and 280.9), cereals and bakery goods (156.37 and 294.47), vegetables (91.73 and 123.22), spices (92.22 and 207.60) and miscellaneous items (138.37 and 137.80) for the Jalangi and Domkal blocks, respectively. Arsenic is absorbed by the skin of most of the vegetables. The arsenic concentration in fleshy vegetable material is low (mean 2.72 microg/kg, n=45). Higher levels of arsenic were observed in cooked items compared with raw. Daily dietary intakes of arsenic (microg) from the foodstuffs for adults are 171.20 and 189.13 and for children are 91.89 and 101.63 in the Jalangi and Domkal blocks, respectively. PMID:12176088

  17. Affective Video Retrieval: Violence Detection in Hollywood Movies by Large-Scale Segmental Feature Extraction

    PubMed Central

    Eyben, Florian; Weninger, Felix; Lehment, Nicolas; Schuller, Björn; Rigoll, Gerhard

    2013-01-01

    Without doubt general video and sound, as found in large multimedia archives, carry emotional information. Thus, audio and video retrieval by certain emotional categories or dimensions could play a central role for tomorrow's intelligent systems, enabling search for movies with a particular mood, computer aided scene and sound design in order to elicit certain emotions in the audience, etc. Yet, the lion's share of research in affective computing is exclusively focusing on signals conveyed by humans, such as affective speech. Uniting the fields of multimedia retrieval and affective computing is believed to lend to a multiplicity of interesting retrieval applications, and at the same time to benefit affective computing research, by moving its methodology “out of the lab” to real-world, diverse data. In this contribution, we address the problem of finding “disturbing” scenes in movies, a scenario that is highly relevant for computer-aided parental guidance. We apply large-scale segmental feature extraction combined with audio-visual classification to the particular task of detecting violence. Our system performs fully data-driven analysis including automatic segmentation. We evaluate the system in terms of mean average precision (MAP) on the official data set of the MediaEval 2012 evaluation campaign's Affect Task, which consists of 18 original Hollywood movies, achieving up to .398 MAP on unseen test data in full realism. An in-depth analysis of the worth of individual features with respect to the target class and the system errors is carried out and reveals the importance of peak-related audio feature extraction and low-level histogram-based video analysis. PMID:24391704

  18. Mental health burden amongst inhabitants of an arsenic-affected area in Inner Mongolia, China.

    PubMed

    Fujino, Yoshihisa; Guo, Xiaojuan; Liu, Jun; You, Lingui; Miyatake, Munetoshi; Yoshimura, Takesumi

    2004-11-01

    Inner Mongolia, China, is an area with high levels of arsenic. The adverse health effects resulting from chronic arsenic exposure include skin keratosis, vascular diseases and cancers. However, the effects of arsenic exposure on mental health have not received much attention. The purpose of this study was to examine the effects of arsenic poisoning on the mental health of the inhabitants of an arsenic-affected area. We performed a cross-sectional study at two villages in Hetao Plain, Inner Mongolia. The populations of both villages were similar in age, sex, lifestyle, socioeconomic conditions, and geographic location. One hundred and thirty four (93.7%) of the 143 inhabitants in the arsenic-affected village and 36 (76.6%) of the 47 inhabitants in the arsenic-free village participated in the study. Subjects with a 30-item version of General Health Questionnaire score of 9 or more were defined as having symptoms of distress. The multiple logistic analyses showed that the mental health of the subjects in the arsenic-affected village was worse than in those in the arsenic-free village (OR=2.5, 95% CI=1.1-6.0). The effect of arsenic on mental health in arsenic-affected areas deserves further investigation. The mental health burden in arsenic-affected areas should be considered in the wider context of public and community health.

  19. Targeting of blood safety measures to affected areas with ongoing local transmission of malaria.

    PubMed

    Domanović, D; Kitchen, A; Politis, C; Panagiotopoulos, T; Bluemel, J; Van Bortel, W; Overbosch, D; Lieshout-Krikke, R; Fabra, C; Facco, G; Zeller, H

    2016-06-01

    An outbreak of locally acquired Plasmodium vivax malaria in Greece started in 2009 and peaked in 2011. Targeting of blood safety measures to affected areas with ongoing transmission of malaria raised questions of how to define spatial boundaries of such an area and when to trigger any specific blood safety measures, including whether and which blood donation screening strategy to apply. To provide scientific advice the European Centre for Disease Prevention and Control (ECDC) organised expert meetings in 2013. The outcomes of these consultations are expert opinions covering spatial targeting of blood safety measures to affected areas with ongoing local transmission of malaria and blood donation screening strategy for evidence of malaria infection in these areas. Opinions could help EU national blood safety authorities in developing a preventive strategy during malaria outbreaks. PMID:27238883

  20. Dynamic Response of Large Wind Power Plant Affected by Diverse Conditions at Individual Turbines

    SciTech Connect

    Elizondo, Marcelo A.; Lu, Shuai; Lin, Guang; Wang, Shaobu

    2014-07-31

    Diverse operating conditions at individual wind turbine generators (WTG) within wind power plants (WPPs) can affect the WPP dynamic response to system faults. For example, individual WTGs can experience diverse terminal voltage and power output caused by different wind direction and speed, affecting the response of protection and control limiters. In this paper, we present a study to investigate the dynamic response of a detailed WPP model under diverse power outputs of its individual WTGs. Wake effect is considered as the reason for diverse power outputs. The diverse WTG power output is evaluated in a test system where a large 168-machine test WPP is connected to the IEEE-39-bus system. The power output from each WTG is derived from a wake effect model that uses realistic statistical data for incoming wind speed and direction. The results show that diverse WTG output due to wake effect can affect the WPP dynamic response activating specialized control in some turbines. In addition, transient stability is affected by exhibiting uncertainty in critical clearing time calculation.

  1. Improved time response for large area microchannel plate photomultiplier tubes in fusion diagnostics

    SciTech Connect

    Milnes, J. S. Conneely, T. M.; Howorth, J.; Horsfield, C. J.

    2014-11-15

    Fusion diagnostics that utilise high speed scintillators often need to capture a large area of light with a high degree of time accuracy. Microchannel plate (MCP) photomultiplier tubes (PMTs) are recognised as the leading device for capturing fast optical signals. However, when manufactured in their traditional proximity focused construction, the time response performance is reduced as the active area increases. This is due to two main factors: the capacitance of a large anode and the difficulty of obtaining small pore MCPs with a large area. Collaboration between Photek and AWE has produced prototype devices that combine the excellent time response of small area MCP-PMTs with a large active area by replacing the traditional proximity-gap front section with an electro-optically focused photocathode to MCP. We present results from both single and double MCP devices with a 40 mm diameter active area and show simulations for the 100 mm device being built this year.

  2. Large family with both parents affected by distinct BRCA1 mutations: implications for genetic testing

    PubMed Central

    Sokolenko, Anna P; Voskresenskiy, Dmitry A; Iyevleva, Aglaya G; Bit-Sava, Elena M; Gutkina, Nadezhda I; Anisimenko, Maxim S; Yu Sherina, Nathalia; Mitiushkina, Nathalia V; Ulibina, Yulia M; Yatsuk, Olga S; Zaitseva, Olga A; Suspitsin, Evgeny N; Togo, Alexandr V; Pospelov, Valery A; Kovalenko, Sergey P; Semiglazov, Vladimir F; Imyanitov, Evgeny N

    2009-01-01

    Although the probability of both parents being affected by BRCA1 mutations is not negligible, such families have not been systematically described in the literature. Here we present a large breast-ovarian cancer family, where 3 sisters and 1 half-sister inherited maternal BRCA1 5382insC mutation while the remaining 2 sisters carried paternal BRCA1 1629delC allele. No BRCA1 homozygous mutations has been detected, that is consistent with the data on lethality of BRCA1 knockout mice. This report exemplifies that the identification of a single cancer-predisposing mutation within the index patient may not be sufficient in some circumstances. Ideally, all family members affected by breast or ovarian tumor disease have to be subjected to the DNA testing, and failure to detect the mutation in any of them calls for the search of the second cancer-associated allele. PMID:19338681

  3. The Spatial Effects of Antenna Configuration in a Large Area Inductively Coupled Plasma System for Flat Panel Displays

    NASA Astrophysics Data System (ADS)

    Seon-Geun, Oh; Young-Jun, Lee; Jae-Hong, Jeon; Jong-Hyeon, Seo; Hee-Hwan, Choe

    2014-08-01

    Spatial distributions of plasma parameters such as electron density, electron temperature and electric potential were investigated using a commercial simulation software (COMSOLTM) to predict the effects of antenna configuration in a large area inductively coupled plasma (ICP) system for flat panel displays. Nine planar antenna sets were evenly placed above a ceramic window. While the electron density was influenced by both the input current and gas pressure, the electron temperature and electric potential were dominantly affected by the gas pressure.

  4. Variables Affecting Delivery of Exceptional Child Services to Rural Areas and Suggested Educational Approaches.

    ERIC Educational Resources Information Center

    Frith, Greg

    Discussed are such variables affecting delivery of services to exceptional children in rural areas as incidence of handicapping conditions, family size, transportation, and communication; and recommended are such educational approaches to the problem as personnel recruitment, parent involvement, mainstreaming, and multi-system cooperation. (IM)

  5. 44 CFR 206.40 - Designation of affected areas and eligible assistance.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 44 Emergency Management and Assistance 1 2010-10-01 2010-10-01 false Designation of affected areas and eligible assistance. 206.40 Section 206.40 Emergency Management and Assistance FEDERAL EMERGENCY MANAGEMENT AGENCY, DEPARTMENT OF HOMELAND SECURITY DISASTER ASSISTANCE FEDERAL DISASTER ASSISTANCE...

  6. Anatomical, physiological and experimental factors affecting the bioavailability of sc administered large biotherapeutics

    PubMed Central

    Fathallah, Anas M.; Balu-Iyer, Sathy V.

    2014-01-01

    Subcutaneous route of administration is highly desirable for protein therapeutics. It improves patient compliance and quality of life1,2, while reducing healthcare cost2. Recent evidence also suggests that sc administration of protein therapeutics can increase tolerability to some treatments such as intravenous immunoglobulin therapy (IVIG) by administering it subcutaneously (subcutaneous immunoglobulin therapy SCIG), which will reduce fluctuation in plasma drug concentration3. Furthermore, sc administration may reduce the risk of systemic infections associated with iv infusion1,2. This route, however, has its challenges especially for large multi-domain proteins. Poor bioavailability and poor scalability from preclinical models are often cited. This commentary will discuss barriers to sc absorption as well as physiological and experimental factors that could affect pharmacokinetics of subcutaneously administered large protein therapeutics in preclinical models. A mechanistic pharmacokinetic model is proposed as a potential tool to address the issue of scalability of sc pharmacokinetic from preclinical models to humans PMID:25411114

  7. Large area high temperature hard X-ray spectroscopy detectors for space experiments

    NASA Astrophysics Data System (ADS)

    Pahari, Mayukh; Yadav, J. S.; Mishra, Suprabha A.; Pandya, Amishkumar

    2010-09-01

    High quantum efficiency, good energy resolution and room temperature operation make Cadmium Zinc Telluride (CZT) pixel detector an unique advantage for space experiments. We present here the results of two large area CZT detector systems; one with external ADC (Analog-to-Digital Converter) and high power Application-Specific Integrated Circuits (ASICs)(Ideas) having faster parallel readout system and the other with on-pixel ADC and low power ASICs (OrboTech) having slower serial readout system. We have studied background, energy resolution and detection efficiency of these detectors between 20 and 100 keV. For Ideas detectors, large power dissipation in ASICs increases the detector temperature (upto 70 °C) and the thermal background. This rise in temperature increases thermal noise sharply which drastically affects both the energy resolution as well as the detection efficiency. The low energy dissipation in OrboTech ASICs keeps the detector temperature low & constant, making thermal background stable. We find that OrboTech resolution & efficiency are far better than that of Ideas detector in spite of slower readout system. We further discuss the use of these detectors in space experiments.

  8. Calibrating an optical scanner for quality assurance of large area radiation detectors

    NASA Astrophysics Data System (ADS)

    Karadzhinova, A.; Hildén, T.; Berdova, M.; Lauhakangas, R.; Heino, J.; Tuominen, E.; Franssila, S.; Hæggström, E.; Kassamakov, I.

    2014-11-01

    A gas electron multiplier (GEM) is a particle detector used in high-energy physics. Its main component is a thin copper-polymer-copper sandwich that carries Ø =70  ±  5 µm holes. Quality assurance (QA) is needed to guarantee both long operating life and reading fidelity of the GEM. Absence of layer defects and conformity of the holes to specifications is important. Both hole size and shape influence the detector’s gas multiplication factor and hence affect the collected data. For the scanner the required lateral measurement tolerance is ± 5 µm. We calibrated a high aspect ratio optical scanning system (OSS) to allow ensuring the quality of large GEM foils. For the calibration we microfabricated transfer standards, which were imaged with the OSS and which were compared to corresponding scanning electron microscopy (SEM) images. The calibration fulfilled the ISO/IEC 17025 and UKAS M3003 requirements: the calibration factor was 1.01  ±  0.01, determined at 95% confidence level across a 950  ×  950 mm2 area. The proposed large-scale scanning technique can potentially be valuable in other microfabricated products too.

  9. Experimental parasite community ecology: intraspecific variation in a large tapeworm affects community assembly.

    PubMed

    Benesh, Daniel P; Kalbe, Martin

    2016-07-01

    Non-random species associations occur in naturally sampled parasite communities. The processes resulting in predictable community structure (e.g. particular host behaviours, cross-immunity, interspecific competition) could be affected by traits that vary within a parasite species, like growth or antigenicity. We experimentally infected three-spined sticklebacks with a large tapeworm (Schistocephalus solidus) that impacts the energy needs, foraging behaviour and immune reactions of its host. The tapeworms came from two populations, characterized by high or low growth in sticklebacks. Our goal was to evaluate how this parasite, and variation in its growth, affects the acquisition of other parasites. Fish infected with S. solidus were placed into cages in a lake to expose them to the natural parasite community. We also performed a laboratory experiment in which infected fish were exposed to a fixed dose of a common trematode parasite. In the field experiment, infection with S. solidus affected the abundance of four parasite species, relative to controls. For two of the four species, changes occurred only in fish harbouring the high-growth S. solidus; one species increased in abundance and the other decreased. These changes did not appear to be directly linked to S. solidus growth though. The parasite exhibiting elevated abundance was the same trematode used in the laboratory infection. In that experiment, we found a similar infection pattern, suggesting that S. solidus affects the physiological susceptibility of fish to this trematode. Associations between S. solidus and other parasites occur and vary in direction. However, some of these associations were contingent on the S. solidus population, suggesting that intraspecific variability can affect the assembly of parasite communities. PMID:27061288

  10. Graphene-based large area dye-sensitized solar cell modules

    NASA Astrophysics Data System (ADS)

    Casaluci, Simone; Gemmi, Mauro; Pellegrini, Vittorio; di Carlo, Aldo; Bonaccorso, Francesco

    2016-02-01

    We demonstrate spray coating of graphene ink as a viable method for large-area fabrication of graphene-based dye-sensitized solar cell (DSSC) modules. A graphene-based ink produced by liquid phase exfoliation of graphite is spray coated onto a transparent conductive oxide substrate to realize a large area (>90 cm2) semi-transparent (transmittance 44%) counter-electrode (CE) replacing platinum, the standard CE material. The graphene-based CE is successfully integrated in a large-area (43.2 cm2 active area) DSSC module achieving a power conversion efficiency of 3.5%. The approach demonstrated here paves the way to all-printed, flexible, and transparent graphene-based large-area and cost-effective photovoltaic devices on arbitrary substrates.

  11. Physically-based failure analysis of shallow layered soil deposits over large areas

    NASA Astrophysics Data System (ADS)

    Cuomo, Sabatino; Castorino, Giuseppe Claudio; Iervolino, Aniello

    2014-05-01

    In the last decades, the analysis of slope stability conditions over large areas has become popular among scientists and practitioners (Cascini et al., 2011; Cuomo and Della Sala, 2013). This is due to the availability of new computational tools (Baum et al., 2002; Godt et al., 2008; Baum and Godt, 2012; Salciarini et al., 2012) - implemented in GIS (Geographic Information System) platforms - which allow taking into account the major hydraulic and mechanical issues related to slope failure, even for unsaturated soils, as well as the spatial variability of both topography and soil properties. However, the effectiveness (Sorbino et al., 2010) of the above methods it is still controversial for landslides forecasting especially depending on the accuracy of DTM (Digital Terrain Model) and for the chance that distinct triggering mechanisms may occur over large area. Among the major uncertainties, layering of soil deposits is of primary importance due to soil layer conductivity contrast and differences in shear strength. This work deals with the hazard analysis of shallow landslides over large areas, considering two distinct schematizations of soil stratigraphy, i.e. homogeneous or layered. To this purpose, the physically-based model TRIGRS (Baum et al., 2002) is firstly used, then extended to the case of layered deposit: specifically, a unique set of hydraulic properties is assumed while distinct soil unit weight and shear strength are considered for each soil layer. Both models are applied to a significant study area of Southern Italy, about 4 km2 large, where shallow deposits of air-fall volcanic (pyroclastic) soils have been affected by several landslides, causing victims, damages and economic losses. The achieved results highlight that soil volume globally mobilized over the study area highly depends on local stratigraphy of shallow deposits. This relates to the depth of critical slip surface which rarely corresponds to the bedrock contact where cohesionless coarse

  12. Reactivation of extremely large paleosinkholes in the Three Gorges Dam area

    NASA Astrophysics Data System (ADS)

    Gao, Y.; Lei, M.

    2012-12-01

    Many large sinkholes and tiankengs were found in the Three Gorges Dam area. Most of these features were paleokarst landforms formed within Triassic carbonate rocks. However, one large sinkhole collapsed on May 30, 1997 in Baotaping, Fengjie area. The collapsing process lasted approximately 30 minutes and formed a 20 m deep and 20 - 25 m wide elliptical shaped sinkhole. Karst features including springs, large sinkholes, caves, joints, and fracture zones were mapped in the study area. In addition, three large paleosinkholes were reported in the study area. Geophysical survey and model experimental study of the Baotaping sinkhole reveals that the collapse of this sinkhole was the result of the reactivation of a paleosinkhole. The Beimengou sinkhole in Ziyang village was an extremely large paleosinkhole with a depth of nearly 60 m. Geologic investigation of this sinkhole demonstrates that this sinkhole was likely formed within the lower Triassic (T1j) limestone and propagated to middle Triassic (T2b) carbonates. The mechanism of the formation of Beimengou sinkhole is probably similar to Tiankengs found in the Fengjie area. Karst feature investigation in the study area shows that many large paleosinkholes and Tiankengs exist within lower and middle Triassic carbonate rocks in the Three Gorges Dam area. Water level and hydrodynamic changes after the construction of the world's largest dam may induce geohazards such as landslides and reactivations of large paleosinkholes in the future.

  13. Diachronic analysis of salt-affected areas using remote sensing techniques: the case study of Biskra area, Algeria

    NASA Astrophysics Data System (ADS)

    Afrasinei, Gabriela M.; Melis, Maria T.; Buttau, Cristina; Bradd, John M.; Arras, Claudio; Ghiglieri, Giorgio

    2015-10-01

    In the Wadi Biskra arid and semi-arid area, sustainable development is limited by land degradation, such as secondary salinization of soils. As an important high quality date production region of Algeria, it needs continuous monitoring of desertification indicators, since the bio-physical setting defines it as highly exposed to climate-related risks. For this particular study, for which little ground truth data was possible to acquire, we set up an assessment of appropriate methods for the identification and change detection of salt-affected areas, involving image interpretation and processing techniques employing Landsat imagery. After a first phase consisting of a visual interpretation study of the land cover types, two automated classification approaches were proposed and applied for this specific study: decision tree classification and principal components analysis (PCA) of Knepper ratios. Five of the indices employed in the Decision Tree construction were set up within the current study, among which we propose a salinity index (SMI) for the extraction of highly saline areas. The results of the 1984 to 2014 diachronic analysis of salt - affected areas variation were supported by the interpreted land cover map for accuracy estimation. Connecting the outputs with auxiliary bio-physical and socio-economic data, comprehensive results are discussed, which were indispensable for the understanding of land degradation dynamics and vulnerability to desertification. One aspect that emerged was the fact that the expansion of agricultural land in the last three decades may have led and continue to contribute to a secondary salinization of soils. This study is part of the WADIS-MAR Demonstration Project, funded by the European Commission through the Sustainable Water Integrated Management (SWIM) Program (www.wadismar.eu).

  14. Cholinergic and serotonergic modulations differentially affect large-scale functional networks in the mouse brain.

    PubMed

    Shah, Disha; Blockx, Ines; Keliris, Georgios A; Kara, Firat; Jonckers, Elisabeth; Verhoye, Marleen; Van der Linden, Annemie

    2016-07-01

    Resting-state functional MRI (rsfMRI) is a widely implemented technique used to investigate large-scale topology in the human brain during health and disease. Studies in mice provide additional advantages, including the possibility to flexibly modulate the brain by pharmacological or genetic manipulations in combination with high-throughput functional connectivity (FC) investigations. Pharmacological modulations that target specific neurotransmitter systems, partly mimicking the effect of pathological events, could allow discriminating the effect of specific systems on functional network disruptions. The current study investigated the effect of cholinergic and serotonergic antagonists on large-scale brain networks in mice. The cholinergic system is involved in cognitive functions and is impaired in, e.g., Alzheimer's disease, while the serotonergic system is involved in emotional and introspective functions and is impaired in, e.g., Alzheimer's disease, depression and autism. Specific interest goes to the default-mode-network (DMN), which is studied extensively in humans and is affected in many neurological disorders. The results show that both cholinergic and serotonergic antagonists impaired the mouse DMN-like network similarly, except that cholinergic modulation additionally affected the retrosplenial cortex. This suggests that both neurotransmitter systems are involved in maintaining integrity of FC within the DMN-like network in mice. Cholinergic and serotonergic modulations also affected other functional networks, however, serotonergic modulation impaired the frontal and thalamus networks more extensively. In conclusion, this study demonstrates the utility of pharmacological rsfMRI in animal models to provide insights into the role of specific neurotransmitter systems on functional networks in neurological disorders. PMID:26195064

  15. The influence of forest shelterbelts on 137Cs fallout in Chernobyl affected areas (Tula region, Russia).

    NASA Astrophysics Data System (ADS)

    Ivanov, Maxim; Shamshurina, Eugeniya; Tatyana, Paramonova; Vladimir, Belyaev; Angelina, Gavruchenkova; Nikolai, Lugovoy; Konstantinov, Pavel

    2015-04-01

    The radioactive fallout after Chernobyl accident caused serious contamination by 137Cs along extensive area of East-European plain.Cs137 fall down on earth surface in two ways: gravitational - "dry" and rainfall - "wet" way. "Dry" fallout is a result of direct deposition of radionuclides from atmosphere with average speed of about 0.1-1 mm/sec. The fate of "dry fall"is far less than rainfall mechanism. Erupted water steam of reactor zone full of radioactive material enriched precipitation with 137Cs. Therefore, the derived spatial structure of contamination was under control of rainfall pattern in May-June 1986. On the areas affected by rainfall fallout was the Southern part of Tula region in Middle Russia. It got name as "Plava hot spot" by the town in the center of this area. Tula is a traditional rural region, the vast areas covered by chernozem soils are cultivated for centuries. During cultivation forest cover was reduced that urged growth of wind erosion and loss of soil fertility. Hence, in the middle of 20 the century large arrangements for creation of forest shelterbelts were conducted. High efficiency of shelterbelts made them a widely provided part of new human-transformed landscape. Usually shelterbelts are set as a regular network across main direction of winds in particular region. Such organization help to reduce speed of air steam in the lowest 20-30 m layer of atmosphere. In addition, shelterbelts are very good collectors of snow in winter time which increase total moisture of soil and its fertility. Represented investigation is conducted to find out any correlation between shelterbelts and fallout of radionuclides. If such correlation is significant, it has to be taken into account for further environmental surveys. Two shelterbelts on the interfluve positions were chosen for detailed examination. Both selected objects emerged before 1986 but have different width, floristic composition, orientation and type of construction. One of shelterbelts is

  16. Motor, cognitive, and affective areas of the cerebral cortex influence the adrenal medulla

    PubMed Central

    Dum, Richard P.; Levinthal, David J.; Strick, Peter L.

    2016-01-01

    Modern medicine has generally viewed the concept of “psychosomatic” disease with suspicion. This view arose partly because no neural networks were known for the mind, conceptually associated with the cerebral cortex, to influence autonomic and endocrine systems that control internal organs. Here, we used transneuronal transport of rabies virus to identify the areas of the primate cerebral cortex that communicate through multisynaptic connections with a major sympathetic effector, the adrenal medulla. We demonstrate that two broad networks in the cerebral cortex have access to the adrenal medulla. The larger network includes all of the cortical motor areas in the frontal lobe and portions of somatosensory cortex. A major component of this network originates from the supplementary motor area and the cingulate motor areas on the medial wall of the hemisphere. These cortical areas are involved in all aspects of skeletomotor control from response selection to motor preparation and movement execution. The second, smaller network originates in regions of medial prefrontal cortex, including a major contribution from pregenual and subgenual regions of anterior cingulate cortex. These cortical areas are involved in higher-order aspects of cognition and affect. These results indicate that specific multisynaptic circuits exist to link movement, cognition, and affect to the function of the adrenal medulla. This circuitry may mediate the effects of internal states like chronic stress and depression on organ function and, thus, provide a concrete neural substrate for some psychosomatic illness. PMID:27528671

  17. Motor, cognitive, and affective areas of the cerebral cortex influence the adrenal medulla.

    PubMed

    Dum, Richard P; Levinthal, David J; Strick, Peter L

    2016-08-30

    Modern medicine has generally viewed the concept of "psychosomatic" disease with suspicion. This view arose partly because no neural networks were known for the mind, conceptually associated with the cerebral cortex, to influence autonomic and endocrine systems that control internal organs. Here, we used transneuronal transport of rabies virus to identify the areas of the primate cerebral cortex that communicate through multisynaptic connections with a major sympathetic effector, the adrenal medulla. We demonstrate that two broad networks in the cerebral cortex have access to the adrenal medulla. The larger network includes all of the cortical motor areas in the frontal lobe and portions of somatosensory cortex. A major component of this network originates from the supplementary motor area and the cingulate motor areas on the medial wall of the hemisphere. These cortical areas are involved in all aspects of skeletomotor control from response selection to motor preparation and movement execution. The second, smaller network originates in regions of medial prefrontal cortex, including a major contribution from pregenual and subgenual regions of anterior cingulate cortex. These cortical areas are involved in higher-order aspects of cognition and affect. These results indicate that specific multisynaptic circuits exist to link movement, cognition, and affect to the function of the adrenal medulla. This circuitry may mediate the effects of internal states like chronic stress and depression on organ function and, thus, provide a concrete neural substrate for some psychosomatic illness. PMID:27528671

  18. Large area substrate for surface enhanced Raman spectroscopy (SERS) using glass-drawing technique

    DOEpatents

    Ivanov, Ilia N.; Simpson, John T.

    2012-06-26

    A method of making a large area substrate comprises drawing a plurality of tubes to form a plurality of drawn tubes, and cutting the plurality of drawn tubes into cut drawn tubes. Each cut drawn tube has a first end and a second end along the longitudinal direction of the respective cut drawn tube. The cut drawn tubes collectively have a predetermined periodicity. The method of making a large area substrate also comprises forming a metal layer on the first ends of the cut drawn tubes to provide a large area substrate.

  19. Evaluation of a WorldView-2 image for soil salinity monitoring in a moderately affected irrigated area

    NASA Astrophysics Data System (ADS)

    Vermeulen, Divan; van Niekerk, Adriaan

    2016-04-01

    Conventional methods for monitoring salt accumulation within irrigation schemes involve regular field visits to collect soil samples for laboratory analysis. Remote sensing has been proposed as a less time-consuming, more cost-effective alternative as it provides imagery covering large areas throughout the year. This study evaluated the efficacy of very high resolution (VHR) WorldView-2 imagery to map areas affected by salt accumulation. Classifications based on thresholds obtained from Jeffries-Matusita distance, regression modeling, classification and regression trees, as well as supervised classification approaches, were evaluated for discriminating between salt-affected and unaffected soils in Vaalharts, South Africa. The WorldView-2 bands were supplemented with salinity indices (SIs), principal components, and texture measures to increase the number of predictive variables. In situ soil samples were used for model development, classifier training, and accuracy assessment. The results showed that a simple threshold implemented on a normalized difference SI was the most successful in separating classes, with an overall accuracy of 80%. The findings suggest that VHR satellite imagery holds much potential for monitoring salt accumulation, but more research is needed to investigate why the classification results tend to overestimate salt-affected areas. More work is also needed to evaluate the transferability of the techniques to other irrigation schemes.

  20. A novel photovoltaic power system which uses a large area concentrator mirror

    NASA Technical Reports Server (NTRS)

    Arrison, Anne; Fatemi, Navid

    1987-01-01

    A preliminary analysis has been made of a novel photovoltaic power system concept. The system is composed of a small area, dense photovoltaic array, a large area solar concentrator, and a battery system for energy storage. The feasibility of such a system is assessed for space power applications. The orbital efficiency, specific power, mass, and area of the system are calculated under various conditions and compared with those for the organic Rankine cycle solar dynamic system proposed for Space Station. Near term and advanced large area concentrator photovoltaic systems not only compare favorably to solar dynamic systems in terms of performance but offer other benefits as well.

  1. Computation of discharge using the index-velocity method in tidally affected areas

    USGS Publications Warehouse

    Ruhl, Catherine A.; Simpson, Michael R.

    2005-01-01

    Computation of a discharge time-series in a tidally affected area is a two-step process. First, the cross-sectional area is computed on the basis of measured water levels and the mean cross-sectional velocity is computed on the basis of the measured index velocity. Then discharge is calculated as the product of the area and mean velocity. Daily mean discharge is computed as the daily average of the low-pass filtered discharge. The Sacramento-San Joaquin River Delta and San Francisco Bay, California, is an area that is strongly influenced by the tides, and therefore is used as an example of how this methodology is used.

  2. Large area crop inventory experiment crop assessment subsystem software requirements document

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The functional data processing requirements are described for the Crop Assessment Subsystem of the Large Area Crop Inventory Experiment. These requirements are used as a guide for software development and implementation.

  3. MUTAGENIC CHARACTERISTICS OF RIVER WATERS FLOWING THROUGH LARGE METROPOLITAN AREAS IN NORTH AMERICA

    EPA Science Inventory

    Mutagenic characteristics of river waters flowing through large metropolitan areas in North America

    The hanging technique using blue rayon, which specifically adsorbs mutagens with multicyclic planar structures, has the advantages over most conventional methods of not havi...

  4. Deep brain stimulation affects conditioned and unconditioned anxiety in different brain areas.

    PubMed

    van Dijk, A; Klanker, M; van Oorschot, N; Post, R; Hamelink, R; Feenstra, M G P; Denys, D

    2013-01-01

    Deep brain stimulation (DBS) of the nucleus accumbens (NAc) has proven to be an effective treatment for therapy refractory obsessive-compulsive disorder. Clinical observations show that anxiety symptoms decrease rapidly following DBS. As in clinical studies different regions are targeted, it is of principal interest to understand which brain area is responsible for the anxiolytic effect and whether high-frequency stimulation of different areas differentially affect unconditioned (innate) and conditioned (learned) anxiety. In this study, we examined the effect of stimulation in five brain areas in rats (NAc core and shell, bed nucleus of the stria terminalis (BNST), internal capsule (IC) and the ventral medial caudate nucleus (CAU)). The elevated plus maze was used to test the effect of stimulation on unconditioned anxiety, the Vogel conflict test for conditioned anxiety, and an activity test for general locomotor behaviour. We found different anxiolytic effects of stimulation in the five target areas. Stimulation of the CAU decreased both conditioned and unconditioned anxiety, while stimulation of the IC uniquely reduced conditioned anxiety. Remarkably, neither the accumbens nor the BNST stimulation affected conditioned or unconditioned anxiety. Locomotor activity increased with NAc core stimulation but decreased with the BNST. These findings suggest that (1) DBS may have a differential effect on unconditioned and conditioned anxiety depending on the stimulation area, and that (2) stimulation of the IC exclusively reduces conditioned anxiety. This suggests that the anxiolytic effects of DBS seen in OCD patients may not be induced by stimulation of the NAc, but rather by the IC. PMID:23900312

  5. Polycrystalline CVD diamond detector: Fast response and high sensitivity with large area

    SciTech Connect

    Liu, Linyue Zhang, Xianpeng; Zhong, Yunhong; Ouyang, Xiaoping Zhang, Jianfu

    2014-01-15

    Polycrystalline diamond was successfully used to fabricate a large area (diameter up to 46 mm) radiation detector. It was proven that the developed detector shows a fast pulsed response time and a high sensitivity, therefore its rise time is lower than 5 ns, which is two times faster than that of a Si-PIN detector of the same size. And because of the large sensitive area, this detector shows good dominance in fast pulsed and low density radiation detection.

  6. Combining large area fluorescence with multiphoton microscopy for improved detection of oral epithelial neoplasia (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Pal, Rahul; Yang, Jinping; Qiu, Suimin; McCammon, Susan; Resto, Vicente; Vargas, Gracie

    2016-03-01

    Volumetric Multiphoton Autofluorescence Microscopy (MPAM) and Second Harmonic Generation Microscopy (SHGM) show promise for revealing indicators of neoplasia representing the complex microstructural organization of mucosa, potentially providing high specificity for detection of neoplasia, but is limited by small imaging area. Large area fluorescence methods on the other hand show high sensitivity appropriate for screening but are hampered by low specificity. In this study, we apply MPAM-SHGM following guidance from large area fluorescence, by either autofluorescence or a targeted metabolic fluorophore, as a potentially clinically viable approach for detection of oral neoplasia. Sites of high neoplastic potentially were identified by large area red/green autofluorescence or by a fluorescently labelled deoxy-glucose analog, 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose (2-NBDG) to highlight areas of high glucose uptake across the buccal pouch of a hamster model for OSCC. Follow-up MPAM-SHGM was conducted on regions of interests (ROIs) to assess whether microscopy would reveal microscopic features associated with neoplasia to confirm or exclude large area fluorescence findings. Parameters for analysis included cytologic metrics, 3D epithelial connective tissue interface metrics (MPAM-SHGM) and intensity of fluorescence (widefield). Imaged sites were biopsied and processed for histology and graded by a pathologist. A small sample of human ex vivo tissues were also imaged. A generalized linear model combining image metrics from large area fluorescence and volumetric MPAM-SHGM indicated the ability to delineate normal and inflammation from neoplasia.

  7. Analysis of shallow landslides and soil erosion induced by rainfall over large areas

    NASA Astrophysics Data System (ADS)

    Cuomo, Sabatino; Della Sala, Maria

    2014-05-01

    Due to heavy rainstorms, steep hillslopes may be affected by either shallow landslides or soil superficial erosion (Acharya et al., 2011), which originate different flow-like mass movements in adjacent or overlapping source areas (Cascini et al., 2013). Triggering analysis (Cascini et al., 2011) is a relevant issue for hazard assessment that is, in turn, the first step of risk analysis procedures (Fell et al., 2008). Nevertheless, the available approaches separately consider shallow landslides and soil erosion. Specifically, quantitative models for landslides triggering analysis allow simulating the physical processes leading to failure such as pore water pressure increase and soil shear mobilization and provide estimates of the amount of material potentially involved; however, success of quantitative methods must be carefully evaluated in complex geological setting as recently outlined (Sorbino et al., 2010) and further applications to real case histories are straightforward. On the other hand, a wide range of models exist for soil erosion analysis, which differ in terms of complexity, processes considered and data required for the model calibration and practical applications; in particular, quantitative models can estimate the source areas and the amount of eroded soil through empirical relationships or mathematical equations describing the main physical processes governing soil erosion (Merritt et al., 2003). In this work a spatially distributed analysis is proposed for testing the potentialities of two available models to respectively investigate the spatial occurrence of first-time shallow landslides and superficial soil erosion repeatedly occurring in a large test area of the Southern Italy. Both analyses take into account the seasonal variation of soil suction, rainfall characteristics and soil cover use (Cuomo and Della Sala, 2013). The achieved results show that the source areas of shallow landslides strongly depend on rainfall intensity and duration and

  8. The large earthquake of 8 August 1303 in Crete: seismic scenario and tsunami in the Mediterranean area

    NASA Astrophysics Data System (ADS)

    Guidoboni, Emanuela; Comastri, Alberto

    By conducting a historical review of this large seismic event in the Mediterranean, it has been possible to identify both the epicentral area and the area in which its effects were principally felt. Ever since the nineteenth century, the seismological tradition has offered a variety of partial interpretations of the earthquake, depending on whether the main sources used were Arabic, Greek or Latin texts. Our systematic research has involved the analysis not only of Arab, Byzantine and Italian chronicle sources, but also and in particular of a large number of never previously used official and public authority documents, preserved in Venice in the State Archive, in the Marciana National Library and in the Library of the Museo Civico Correr. As a result, it has been possible to establish not only chronological parameters for the earthquake (they were previously uncertain) but also its overall effects (epicentral area in Crete, Imax XI MCS). Sources containing information in 41 affected localities and areas were identified. The earthquake also gave rise to a large tsunami, which scholars have seen as having certain interesting elements in common with that of 21 July 365, whose epicentre was also in Crete. As regards methodology, this research made it clear that knowledge of large historical earthquakes in the Mediterranean is dependent upon developing specialised research and going beyond the territorial limits of current national catalogues.

  9. Going home after Hurricane Katrina: Determinants of return migration and changes in affected areas.

    PubMed

    Groen, Jeffrey A; Polivka, Anne E

    2010-11-01

    This article examines the decision of Hurricane Katrina evacuees to return to their pre-Katrina areas and documents how the composition of the Katrina-affected region changed over time. Using data from the Current Population Survey, we show that an evacuee's age, family income, and the severity of damage in an evacuee's county of origin are important determinants of whether an evacuee returned during the first year after the storm. Blacks were less likely to return than whites, but this difference is primarily related to the geographical pattern of storm damage rather than to race per se. The difference between the composition of evacuees who returned and the composition of evacuees who did not return is the primary force behind changes in the composition of the affected areas in the first two years after the storm. Katrina is associated with substantial shifts in the racial composition of the affected areas (namely, a decrease in the percentage of residents who are black) and an increasing presence of Hispanics. Katrina is also associated with an increase in the percentage of older residents, a decrease in the percentage of residents with low income/education, and an increase in the percentage of residents with high income/education. PMID:21308560

  10. Going home after Hurricane Katrina: Determinants of return migration and changes in affected areas.

    PubMed

    Groen, Jeffrey A; Polivka, Anne E

    2010-11-01

    This article examines the decision of Hurricane Katrina evacuees to return to their pre-Katrina areas and documents how the composition of the Katrina-affected region changed over time. Using data from the Current Population Survey, we show that an evacuee's age, family income, and the severity of damage in an evacuee's county of origin are important determinants of whether an evacuee returned during the first year after the storm. Blacks were less likely to return than whites, but this difference is primarily related to the geographical pattern of storm damage rather than to race per se. The difference between the composition of evacuees who returned and the composition of evacuees who did not return is the primary force behind changes in the composition of the affected areas in the first two years after the storm. Katrina is associated with substantial shifts in the racial composition of the affected areas (namely, a decrease in the percentage of residents who are black) and an increasing presence of Hispanics. Katrina is also associated with an increase in the percentage of older residents, a decrease in the percentage of residents with low income/education, and an increase in the percentage of residents with high income/education.

  11. Going Home after Hurricane Katrina: Determinants of Return Migration and Changes in Affected Areas

    PubMed Central

    GROEN, JEFFREY A.; POLIVKA, ANNE E.

    2010-01-01

    This article examines the decision of Hurricane Katrina evacuees to return to their pre-Katrina areas and documents how the composition of the Katrina-affected region changed over time. Using data from the Current Population Survey, we show that an evacuee’s age, family income, and the severity of damage in an evacuee’s county of origin are important determinants of whether an evacuee returned during the first year after the storm. Blacks were less likely to return than whites, but this difference is primarily related to the geographical pattern of storm damage rather than to race per se. The difference between the composition of evacuees who returned and the composition of evacuees who did not return is the primary force behind changes in the composition of the affected areas in the first two years after the storm. Katrina is associated with substantial shifts in the racial composition of the affected areas (namely, a decrease in the percentage of residents who are black) and an increasing presence of Hispanics. Katrina is also associated with an increase in the percentage of older residents, a decrease in the percentage of residents with low income/education, and an increase in the percentage of residents with high income/education. PMID:21308560

  12. Detecting Change in Landscape Greenness over Large Areas: An Example for New Mexico, USA

    EPA Science Inventory

    Monitoring and quantifying changes in vegetation cover over large areas using remote sensing can potentially detect large-scale, slow changes (e.g., climate change), as well as more local and rapid changes (e.g., fire, land development). A useful indicator for detecting change i...

  13. Habitat restoration across large areas: Assessing wildlife responses in the Clearwater basin, Idaho

    USGS Publications Warehouse

    Scanvara, L.K.; Servheen, G.; Melquist, W.; Davis, D.; Scott, J.M.

    2004-01-01

    Over the past century, fire suppression and prevention have altered disturbance regimes across the Pacific Northwest, resulting in a significant divergence of historical and current conditions in forested habitats. To address this continuing trend in habitat changes and begin restoring historical patterns of disturbance, the Clearwater Basin Elk Habitat Initiative (CEI) proposes relatively extensive management actions in the Clearwater basin of north-central Idaho. We attempted to evaluate potential effects of such management actions on selected wildlife species using extant data sets and suggest ways to improve such projects with respect to a multispecies and adaptive management approach. Although there is increased interest in ecosystem management over large areas, the increased scale of analysis and implementation require a substantial increase in the level of species information beyond what currently exists. We conclude that baseline information required for an effective multispecies land-management policy in the Clearwater basin does not exist for many terrestrial wildlife species. To implement a true multispecies or ecosystem approach, wildlife and land managers should cooperate to increase existing population data and modeling efforts for wildlife species in the basin and develop a sustainable monitoring program to evaluate habitat management changes and their influence on wildlife populations within the context of adaptive management theory. Management actions to restore disturbance patterns should attempt spatial and temporal scales that are biologically relevant to the population ecology of species being affected. ?? 2004 by the Society of American Foresters.

  14. Large area UV casting using diverse polyacrylates of microchannels separated by high aspect ratio microwalls.

    PubMed

    Zhou, W X; Chan-Park, Mary B

    2005-05-01

    Large area molding of long and deep microchannels separated by high aspect ratio microwalls is important for high sensitivity and high throughput microfluidic devices. Ultraviolet (UV) casting is a feasible, economical and convenient method of replication of such microstructures in plastics. It is shown that a wide variety of polyacrylates with diverse properties such as those made from epoxy (EP), polyurethane (UR), polyester (ES), poly (ethylene glycol) (EG) and poly(propylene glycol) (PG) can be used for the high aspect ratio (7-9) UV casting of such linear microstructures over a 100 mm diameter, enlarging the range of applications of the replicated microstructures. Some challenges arise. With the EG formulation, wavy microstructures were observed; this can be overcome by stress relaxation. With non-polar PG formulation, poor adhesion between the polyester substrate and resin can lead to delamination of the casting from the substrate during demolding; this can be overcome by pre-coating a partially cured same resin on the polyester substrate. An optimum UV irradiation time was important for cure at the deepest end of the microstructure without excessive crosslinking leading to much increased demolding forces. The viscosity and wetting capability of the formulations were found to affect replication fidelity.

  15. Air pollution impacts of speed limitation measures in large cities: The need for improving traffic data in a metropolitan area

    NASA Astrophysics Data System (ADS)

    Baldasano, José M.; Gonçalves, María; Soret, Albert; Jiménez-Guerrero, Pedro

    2010-08-01

    Assessing the effects of air quality management strategies in urban areas is a major concern worldwide because of the large impacts on health caused by the exposure to air pollution. In this sense, this work analyses the changes in urban air quality due to the introduction of a maximum speed limit to 80 km h -1 on motorways in a large city by using a novel methodology combining traffic assimilation data and modelling systems implemented in a supercomputing facility. Albeit the methodology has been non-specifically developed and can be extrapolated to any large city or megacity, the case study of Barcelona is presented here. Hourly simulations take into account the entire year 2008 (when the 80 km h -1 limit has been introduced) vs. the traffic conditions for the year 2007. The data has been assimilated in an emission model, which considers hourly variable speeds and hourly traffic intensity in the affected area, taken from long-term measurement campaigns for the aforementioned years; it also permits to take into account the traffic congestion effect. Overall, the emissions are reduced up to 4%; however the local effects of this reduction achieve an important impact for the adjacent area to the roadways, reaching 11%. In this sense, the speed limitation effects assessed represent enhancements in air quality levels (5-7%) of primary pollutants over the area, directly improving the welfare of 1.35 million inhabitants (over 41% of the population of the Metropolitan Area) and affecting 3.29 million dwellers who are potentially benefited from this strategy for air quality management (reducing 0.6% the mortality rates in the area).

  16. Large-scale synthesis of high-quality hexagonal boron nitride nanosheets for large-area graphene electronics.

    PubMed

    Lee, Kang Hyuck; Shin, Hyeon-Jin; Lee, Jinyeong; Lee, In-yeal; Kim, Gil-Ho; Choi, Jae-Young; Kim, Sang-Woo

    2012-02-01

    Hexagonal boron nitride (h-BN) has received a great deal of attention as a substrate material for high-performance graphene electronics because it has an atomically smooth surface, lattice constant similar to that of graphene, large optical phonon modes, and a large electrical band gap. Herein, we report the large-scale synthesis of high-quality h-BN nanosheets in a chemical vapor deposition (CVD) process by controlling the surface morphologies of the copper (Cu) catalysts. It was found that morphology control of the Cu foil is much critical for the formation of the pure h-BN nanosheets as well as the improvement of their crystallinity. For the first time, we demonstrate the performance enhancement of CVD-based graphene devices with large-scale h-BN nanosheets. The mobility of the graphene device on the h-BN nanosheets was increased 3 times compared to that without the h-BN nanosheets. The on-off ratio of the drain current is 2 times higher than that of the graphene device without h-BN. This work suggests that high-quality h-BN nanosheets based on CVD are very promising for high-performance large-area graphene electronics. PMID:22220633

  17. Recognition of large scale deep-seated landslides in vegetated areas of Taiwan

    NASA Astrophysics Data System (ADS)

    Lin, C. W.; Tarolli, P.; Tseng, C. M.; Tseng, Y. H.

    2012-04-01

    In August 2009, Typhoon Morakot triggered thousands of landslides and debris flows, and according to government reports, 619 people were dead and 76 missing and the economic loss was estimated at hundreds million of USD. In particular, the large deep-seated landslides are critical and deserve attention, since they can be affected by a reactivation during intense events, that usually can evolve in destructive failures. These are also difficult to recognize in the field, especially under dense forest areas. A detailed and constantly updated inventory map of such phenomena, and the recognition of their topographic signatures really represents a key tool for landslide risk mitigation, and mapping. The aim of this work is to test the performance of a new developed method for the automatic extraction of geomorphic features related to landslide crowns developed by Tarolli et al. (2010), in support to field surveys in order to develop a detailed and accurate inventory map of such phenomena. The methodology is based on the detection of thresholds derived by the statistical analysis of variability of landform curvature from high resolution LiDAR derived topography. The analysis suggested that the method allowed a good performance in localization and extraction, respect to field analysis, of features related to deep-seated landslides. Thanks to LiDAR capabilty to detect the bare ground elevation data also in forested areas, it was possible to recognize in detail landslide features also in remote regions difficult to access. Reference Tarolli, P., Sofia, G., Dalla Fontana, G. (2010). Geomorphic features extraction from high-resolution topography: landslide crowns and bank erosion, Natural Hazards, doi:10.1007/s11069-010-9695-2

  18. Large herbivore grazing affects the vegetation structure and greenhouse gas balance in a high arctic mire

    NASA Astrophysics Data System (ADS)

    Falk, Julie Maria; Schmidt, Niels Martin; Christensen, Torben R.; Ström, Lena

    2015-04-01

    Herbivory is an important part of most ecosystems and affects the ecosystems’ carbon balance both directly and indirectly. Little is known about herbivory and its impact on the carbon balance in high arctic mire ecosystems. We hypothesized that trampling and grazing by large herbivores influences the vegetation density and composition and thereby also the carbon balance. In 2010, we established fenced exclosures in high arctic Greenland to prevent muskoxen (Ovibos moschatus) from grazing. During the growing seasons of 2011 to 2013 we measured CO2 and CH4 fluxes in these ungrazed blocks and compared them to blocks subjected to natural grazing. Additionally, we measured depth of the water table and active layer, soil temperature, and in 2011 and 2013 an inventory of the vegetation density and composition were made. In 2013 a significant decrease in total number of vascular plant (33-44%) and Eriophorum scheuchzeri (51-53%) tillers were found in ungrazed plots, the moss-layer and amount of litter had also increased substantially in these plots. This resulted in a significant decrease in net ecosystem uptake of CO2 (47%) and likewise a decrease in CH4 emission (44%) in ungrazed plots in 2013. While the future of the muskoxen in a changing arctic is unknown, this experiment points to a potentially large effect of large herbivores on the carbon balance in natural Arctic ecosystems. It thus sheds light on the importance of grazing mammals, and hence adds to our understanding of natural ecosystem greenhouse gas balance in the past and in the future.

  19. Through what mechanisms do protected areas affect environmental and social outcomes?

    PubMed Central

    Ferraro, Paul J.; Hanauer, Merlin M.

    2015-01-01

    To develop effective protected area policies, scholars and practitioners must better understand the mechanisms through which protected areas affect social and environmental outcomes. With strong evidence about mechanisms, the key elements of success can be strengthened, and the key elements of failure can be eliminated or repaired. Unfortunately, empirical evidence about these mechanisms is limited, and little guidance for quantifying them exists. This essay assesses what mechanisms have been hypothesized, what empirical evidence exists for their relative contributions and what advances have been made in the past decade for estimating mechanism causal effects from non-experimental data. The essay concludes with a proposed agenda for building an evidence base about protected area mechanisms. PMID:26460122

  20. CVD diamond wafers as large-area thermoluminescence detectors for measuring the spatial distribution of dose

    NASA Astrophysics Data System (ADS)

    Marczewska, B.; Bilski, P.; Olko, P.; Olko, P.; Nesládek, M.; Bergonzo, P.; Rbisz, M.; Waligórski, M. P. R.

    2003-09-01

    The applicability of large-area CVD diamond wafers (diameter about 5 cm, thickness about 0.1 mm), read out as thermoluminescence (TL) detectors, for assessing two-dimensional (2-D) dose distribution over their area, was investigated. To obtain 2-D TL images, a special TL reader equipped with large-area planchet and a CCD camera instead of the usual PM tube was developed. Several 2-D TL images: of an alpha source (Am-241), a Ra-226 needle source and a Ru-106 ophthalmic applicator, were measured and high-resolution digital images obtained. Our preliminary results demonstrate the potential capability of large-area CVD diamond wafers, read out as TL detectors, in 2-D dosimetry for medical applications. (

  1. Development of broadband X-ray interference lithography large area exposure system

    NASA Astrophysics Data System (ADS)

    Xue, Chaofan; Wu, Yanqing; Zhu, Fangyuan; Yang, Shumin; Liu, Haigang; Zhao, Jun; Wang, Liansheng; Tai, Renzhong

    2016-04-01

    The single-exposure patterned area is about several 102 × 102 μm2 which is mainly decided by the mask area in multi-beam X-ray interference lithography (XIL). The exposure area is difficult to stitch to a larger one because the patterned area is surrounded by 0th diffraction exposure areas. To block the 0th diffraction beams precisely and effectively, a new large area exposure technology is developed in the Shanghai Synchrotron Radiation Facility by applying an order-sorting aperture with a new in situ monitoring scheme in the XIL system. The patterned area could be stitched readily up to several square centimeters and even bigger by this technology.

  2. Development of broadband X-ray interference lithography large area exposure system.

    PubMed

    Xue, Chaofan; Wu, Yanqing; Zhu, Fangyuan; Yang, Shumin; Liu, Haigang; Zhao, Jun; Wang, Liansheng; Tai, Renzhong

    2016-04-01

    The single-exposure patterned area is about several 10(2) × 10(2) μm(2) which is mainly decided by the mask area in multi-beam X-ray interference lithography (XIL). The exposure area is difficult to stitch to a larger one because the patterned area is surrounded by 0th diffraction exposure areas. To block the 0th diffraction beams precisely and effectively, a new large area exposure technology is developed in the Shanghai Synchrotron Radiation Facility by applying an order-sorting aperture with a new in situ monitoring scheme in the XIL system. The patterned area could be stitched readily up to several square centimeters and even bigger by this technology. PMID:27131667

  3. Can large scale sea ice cover changes affect precipitation patterns over California?

    NASA Astrophysics Data System (ADS)

    Cvijanovic, I.; Bonfils, C.; Lucas, D. D.; Santer, B. D.; Chiang, J. C. H.

    2015-12-01

    Pronounced Arctic sea ice loss since the beginning of the satellite era has intensified the interest into whether these high latitude changes can significantly influence the weather and climate far from the Arctic. Current attempts to demonstrate statistically significant remote responses to sea ice changes have been hindered by factors such as large high latitude variability, relatively short observational datasets, and model limitations in adequately representing current sea ice changes. In this study, we sample uncertainty in sea ice physics parameters and variability in atmospheric initial conditions to obtain an ensemble of simulations with substantially different states of Arctic and Antarctic sea ice cover. This large ensemble isolates a robust, statistically significant climate change response arising from changes in sea ice cover only. Our results show a significant link between Arctic and Antarctic sea ice cover changes and precipitation across the tropical Atlantic and Pacific basins, the Sahel, and the west coast of the United States. For example, large Arctic sea ice decline leads to a northward shift of the tropical convergence zone, increased subsidence over the southwest United States and a geopotential anomaly over the North Pacific; with all of these factors resulting in significant drying over California. We conclude that high-latitude sea ice cover changes are an important driver of low-latitude precipitation. Consequently, reliable predictions of future precipitation changes over areas such as California (and the Sahel) will strongly depend on our ability to adequately simulate both Arctic and Antarctic sea ice changes. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and is released as LLNL-ABS-675694.

  4. Prevalence of HCV and HIV infections in 2005-Earthquake-affected areas of Pakistan

    PubMed Central

    Khan, Saeed; Rai, Mohammad A; Khan, Adnan; Farooqui, Amber; Kazmi, Shahana U; Ali, Syed H

    2008-01-01

    Background On October 8, 2005, an earthquake of magnitude 7.6 hit the Northern parts of Pakistan. In the post-earthquake scenario, overcrowding, improper sewage disposal, contamination of food and drinking water, hasty surgical procedures, and unscreened blood transfusions to earthquake victims most likely promotes the spread of infections already prevalent in the area. Objective The objective of the study reported here was to determine the prevalence of Human Immunodeficiency and Hepatitis C viruses (respectively, HIV and HCV) in the earthquake-affected communities of Pakistan. The samples were analyzed 2 months and then again 11 months after the earthquake to estimate the burden of HIV and HCV in these areas, and to determine any rise in the prevalence of these viral infections as a result of the earthquake. Methods Blood samples were initially collected during December, 2005 to March 2006, from 245 inhabitants of the earthquake-affected areas. These samples were screened for HCV and HIV, using immunochromatography and Enzyme-Linked Immuno-Sorbent Assay (ELISA). Results Out of 245 samples tested, 8 (3.26%) were found positive for HCV, and 0 (0.0%) for HIV, indicating the existence of HCV infection in the earthquake-stricken areas. The same methods were used to analyze the samples collected in the second round of screening in the same area, in September, 2006 – 11 months after the earthquake. This time 290 blood samples were collected, out of which 16 (5.51%) samples were positive for HCV, and 0 for HIV. Conclusion A slightly higher prevalence of HCV was recorded 11 months after the earthquake; this increase, however, was not statistically significant. None of the study participants was found HIV-infected. PMID:18954443

  5. Ecological and physiological factors affecting brood patch area and prolactin levels in arctic-nesting geese

    USGS Publications Warehouse

    Jonsson, J.E.; Afton, A.D.; Alisauskas, R.T.; Bluhm, C.K.; El Halawani, M.E.

    2006-01-01

    We investigated effects of ecological and physiological factors on brood patch area and prolactin levels in free-ranging Lesser Snow Geese (Chen caerulescens caerulescens; hereafter "Snow Geese") and Ross's Geese (C. rossii). On the basis of the body-size hypothesis, we predicted that the relationships between prolactin levels, brood patch area, and body condition would be stronger in Ross's Geese than in the larger Snow Geese. We found that brood patch area was positively related to clutch volume and inversely related to prolactin levels in Ross's Geese, but not in Snow Geese. Nest size, nest habitat, and first egg date did not affect brood patch area in either species. Prolactin levels increased as incubation progressed in female Snow Geese, but this relationship was not significant in Ross's Geese. Prolactin levels and body condition (as indexed by size-adjusted body mass) were inversely related in Ross's Geese, but not in Snow Geese. Our findings are consistent with the prediction that relationships between prolactin levels, brood patch area, and body condition are relatively stronger in Ross's Geese, because they mobilize endogenous reserves at faster rates than Snow Geese. ?? The American Ornithologists' Union, 2006. Printed in USA.

  6. Affective Analgesia following Muscarinic Activation of the Ventral Tegmental Area in Rats

    PubMed Central

    Kender, Robert G.; Harte, Steven E.; Munn, Elizabeth M.; Borszcz, George S.

    2009-01-01

    Cholinergic stimulation of dopamine neurons in the ventral tegmental area (VTA) underlies activation of the brain reward circuitry. Activation of this circuit is proposed to preferentially suppress the affective reaction to noxious stimulation. Vocalization afterdischarges (VADs) are a validated model of the affective response of rats to noxious tailshock. The antinociceptive action of the acetylcholine agonist carbachol microinjected into the VTA on VAD threshold was compared to its effect on the thresholds of other tailshock-elicited responses (VDS = vocalizations during shock, and SMR = spinal motor reflexes). Whereas VADs are organized within the forebrain, VDSs and SMRs are organized at medullary and spinal levels of the neuraxis, respectively. Carbachol (1 μg, 2 μg, and 4 μg) injected into VTA produced dose-dependent increases in VAD and VDS thresholds, although increases in VAD threshold were significantly greater than increases in VDS threshold. Administration of carbachol into VTA failed to elevate SMR threshold. Elevations in vocalization thresholds produced by intra-VTA carbachol were reversed in a dose-dependent manner by local administration of the muscarinic receptor antagonist atropine sulfate (30 μg and 60 μg). These results provide the first demonstration of the involvement of the VTA in muscarinic-induced suppression of pain affect. Perspective Cholinergic activation of the brain reward circuit produced a preferential suppression of rats’ affective reaction to noxious stimulation. The neurobiology that relates reinforcement to suppression of pain affect may provide insights into new treatments for pain and its associated affective disorders. PMID:18387853

  7. Ten factors that affect the severity of environmental impacts of visitors in protected areas.

    PubMed

    Pickering, Catherine Marina

    2010-02-01

    Protected areas represent the major method for conserving biodiversity. However, visitor use can threaten their conservation value. Based on a review of recent research, I have categorized factors that affect the severity of environmental impacts of visitor use. These factors need to be considered or evaluated when assessing visitor use of sites in protected areas. They are: (i) the conservation value of the site, (ii) its resistance to use, (iii) its recovery from use, (iv) its susceptibility to erosion, (v) the severity of direct impacts associated with specific activities, (vi) the severity of indirect impacts, (vii) the amount of use, (viii) the social and (ix) ecological dimensions to the timing of use, and (x) the total area affected. Although the factors may not be of equal importance or necessarily assessed on an equal scale, they allow people to make more informed assessments of potential impacts, assist in identifying where monitoring may be required, and indicate where additional site- or activity-specific research may be appropriate.

  8. Synthesis of Large Area Graphene for High Performance in Flexible Optoelectronic Devices

    PubMed Central

    Polat, Emre O.; Balci, Osman; Kakenov, Nurbek; Uzlu, Hasan Burkay; Kocabas, Coskun; Dahiya, Ravinder

    2015-01-01

    This work demonstrates an attractive low-cost route to obtain large area and high-quality graphene films by using the ultra-smooth copper foils which are typically used as the negative electrodes in lithium-ion batteries. We first compared the electronic transport properties of our new graphene film with the one synthesized by using commonly used standard copper foils in chemical vapor deposition (CVD). We observed a stark improvement in the electrical performance of the transistors realized on our graphene films. To study the optical properties on large area, we transferred CVD based graphene to transparent flexible substrates using hot lamination method and performed large area optical scanning. We demonstrate the promise of our high quality graphene films for large areas with ~400 cm2 flexible optical modulators. We obtained a profound light modulation over a broad spectrum by using the fabricated large area transparent graphene supercapacitors and we compared the performance of our devices with the one based on graphene from standard copper. We propose that the copper foils used in the lithium-ion batteries could be used to obtain high-quality graphene at much lower-cost, with the improved performance of electrical transport and optical properties in the devices made from them. PMID:26578425

  9. Synthesis of Large Area Graphene for High Performance in Flexible Optoelectronic Devices.

    PubMed

    Polat, Emre O; Balci, Osman; Kakenov, Nurbek; Uzlu, Hasan Burkay; Kocabas, Coskun; Dahiya, Ravinder

    2015-01-01

    This work demonstrates an attractive low-cost route to obtain large area and high-quality graphene films by using the ultra-smooth copper foils which are typically used as the negative electrodes in lithium-ion batteries. We first compared the electronic transport properties of our new graphene film with the one synthesized by using commonly used standard copper foils in chemical vapor deposition (CVD). We observed a stark improvement in the electrical performance of the transistors realized on our graphene films. To study the optical properties on large area, we transferred CVD based graphene to transparent flexible substrates using hot lamination method and performed large area optical scanning. We demonstrate the promise of our high quality graphene films for large areas with ~400 cm(2) flexible optical modulators. We obtained a profound light modulation over a broad spectrum by using the fabricated large area transparent graphene supercapacitors and we compared the performance of our devices with the one based on graphene from standard copper. We propose that the copper foils used in the lithium-ion batteries could be used to obtain high-quality graphene at much lower-cost, with the improved performance of electrical transport and optical properties in the devices made from them. PMID:26578425

  10. Synthesis of Large Area Graphene for High Performance in Flexible Optoelectronic Devices

    NASA Astrophysics Data System (ADS)

    Polat, Emre O.; Balci, Osman; Kakenov, Nurbek; Uzlu, Hasan Burkay; Kocabas, Coskun; Dahiya, Ravinder

    2015-11-01

    This work demonstrates an attractive low-cost route to obtain large area and high-quality graphene films by using the ultra-smooth copper foils which are typically used as the negative electrodes in lithium-ion batteries. We first compared the electronic transport properties of our new graphene film with the one synthesized by using commonly used standard copper foils in chemical vapor deposition (CVD). We observed a stark improvement in the electrical performance of the transistors realized on our graphene films. To study the optical properties on large area, we transferred CVD based graphene to transparent flexible substrates using hot lamination method and performed large area optical scanning. We demonstrate the promise of our high quality graphene films for large areas with ~400 cm2 flexible optical modulators. We obtained a profound light modulation over a broad spectrum by using the fabricated large area transparent graphene supercapacitors and we compared the performance of our devices with the one based on graphene from standard copper. We propose that the copper foils used in the lithium-ion batteries could be used to obtain high-quality graphene at much lower-cost, with the improved performance of electrical transport and optical properties in the devices made from them.

  11. Simple room-temperature preparation of high-yield large-area graphene oxide.

    PubMed

    Huang, N M; Lim, H N; Chia, C H; Yarmo, M A; Muhamad, M R

    2011-01-01

    Graphene has attracted much attention from researchers due to its interesting mechanical, electrochemical, and electronic properties. It has many potential applications such as polymer filler, sensor, energy conversion, and energy storage devices. Graphene-based nanocomposites are under an intense spotlight amongst researchers. A large amount of graphene is required for preparation of such samples. Lately, graphene-based materials have been the target for fundamental life science investigations. Despite graphene being a much sought-after raw material, the drawbacks in the preparation of graphene are that it is a challenge amongst researchers to produce this material in a scalable quantity and that there is a concern about its safety. Thus, a simple and efficient method for the preparation of graphene oxide (GO) is greatly desired to address these problems. In this work, one-pot chemical oxidation of graphite was carried out at room temperature for the preparation of large-area GO with ~100% conversion. This high-conversion preparation of large-area GO was achieved using a simplified Hummer's method from large graphite flakes (an average flake size of 500 μm). It was found that a high degree of oxidation of graphite could be realized by stirring graphite in a mixture of acids and potassium permanganate, resulting in GO with large lateral dimension and area, which could reach up to 120 μm and ~8000 μm(2), respectively. The simplified Hummer's method provides a facile approach for the preparation of large-area GO. PMID:22267928

  12. Simple room-temperature preparation of high-yield large-area graphene oxide.

    PubMed

    Huang, N M; Lim, H N; Chia, C H; Yarmo, M A; Muhamad, M R

    2011-01-01

    Graphene has attracted much attention from researchers due to its interesting mechanical, electrochemical, and electronic properties. It has many potential applications such as polymer filler, sensor, energy conversion, and energy storage devices. Graphene-based nanocomposites are under an intense spotlight amongst researchers. A large amount of graphene is required for preparation of such samples. Lately, graphene-based materials have been the target for fundamental life science investigations. Despite graphene being a much sought-after raw material, the drawbacks in the preparation of graphene are that it is a challenge amongst researchers to produce this material in a scalable quantity and that there is a concern about its safety. Thus, a simple and efficient method for the preparation of graphene oxide (GO) is greatly desired to address these problems. In this work, one-pot chemical oxidation of graphite was carried out at room temperature for the preparation of large-area GO with ~100% conversion. This high-conversion preparation of large-area GO was achieved using a simplified Hummer's method from large graphite flakes (an average flake size of 500 μm). It was found that a high degree of oxidation of graphite could be realized by stirring graphite in a mixture of acids and potassium permanganate, resulting in GO with large lateral dimension and area, which could reach up to 120 μm and ~8000 μm(2), respectively. The simplified Hummer's method provides a facile approach for the preparation of large-area GO.

  13. Fast and large-area growth of uniform MoS2 monolayers on molybdenum foils

    NASA Astrophysics Data System (ADS)

    Tai, Guoan; Zeng, Tian; Yu, Jin; Zhou, Jianxin; You, Yuncheng; Wang, Xufeng; Wu, Hongrong; Sun, Xu; Hu, Tingsong; Guo, Wanlin

    2016-01-01

    A controllable synthesis of two-dimensional crystal monolayers in a large area is a prerequisite for potential applications, but the growth of transition metal dichalcogenide monolayers in a large area with spatial homogeneity remains a great challenge. Here we report a novel and efficient method to fabricate large-scale MoS2 monolayers by direct sulfurization of pre-annealed molybdenum foil surfaces with large grain boundaries of more than 50 μm in size at elevated temperatures. Continuous MoS2 monolayers can be formed uniformly by sulfurizing the Mo foils in sulfur vapor at 600 °C within 1 min. At a lower temperature even down to 500 °C, uniform MoS2 monolayers can still be obtained but in a much longer sulfurizing duration. It is demonstrated that the formed monolayers can be nondestructively transferred onto arbitrary substrates by removing the Mo foil using diluted ferric chloride solution and can be successfully fabricated into photodetectors. The results show a novel avenue to efficiently fabricate two-dimensional crystals in a large area in a highly controllable way and should have great potential for the development of large-scale applications of two-dimensional crystals in electrophotonic systems.A controllable synthesis of two-dimensional crystal monolayers in a large area is a prerequisite for potential applications, but the growth of transition metal dichalcogenide monolayers in a large area with spatial homogeneity remains a great challenge. Here we report a novel and efficient method to fabricate large-scale MoS2 monolayers by direct sulfurization of pre-annealed molybdenum foil surfaces with large grain boundaries of more than 50 μm in size at elevated temperatures. Continuous MoS2 monolayers can be formed uniformly by sulfurizing the Mo foils in sulfur vapor at 600 °C within 1 min. At a lower temperature even down to 500 °C, uniform MoS2 monolayers can still be obtained but in a much longer sulfurizing duration. It is demonstrated that the

  14. A New Algorithm for Detection of Cloudiness and Moon Affect Area

    NASA Astrophysics Data System (ADS)

    Dindar, Murat; Helhel, Selcuk; Ünal Akdemir, Kemal

    2016-07-01

    Cloud detection is a crucial issue for observatories already operating and during phase of the site selection. Sky Quality Meter (SQM) devices mostly use to determine parameters of the quality of sky such as cloudiness, light flux. But, those parameters do not give us exact information about the cloudiness and moon affects. In this study we improved a new cloudiness and moon affects area detection algorithm. The algorithm is based on image processing methods and different approaches applied to both day time and night time images to calculate the sky coverage. The new algorithm also implemented with Matlab by using the images taken by all sky camera located at TÜBİTAK National Observatory and results were given.

  15. Factors affecting fuel break effectiveness in the control of large fires on the Los Padres National Forest, California

    USGS Publications Warehouse

    Syphard, Alexandra D.; Keeley, Jon E.; Brennan, Teresa J.

    2011-01-01

    As wildfires have increased in frequency and extent, so have the number of homes developed in the wildland-urban interface. In California, the predominant approach to mitigating fire risk is construction of fuel breaks, but there has been little empirical study of their role in controlling large fires.We constructed a spatial database of fuel breaks on the Los Padres National Forest in southern California to better understand characteristics of fuel breaks that affect the behaviour of large fires and to map where fires and fuel breaks most commonly intersect. We evaluated whether fires stopped or crossed over fuel breaks over a 28-year period and compared the outcomes with physical characteristics of the sites, weather and firefighting activities during the fire event. Many fuel breaks never intersected fires, but others intersected several, primarily in historically fire-prone areas. Fires stopped at fuel breaks 46% of the time, almost invariably owing to fire suppression activities. Firefighter access to treatments, smaller fires and longer fuel breaks were significant direct influences, and younger vegetation and fuel break maintenance indirectly improved the outcome by facilitating firefighter access. This study illustrates the importance of strategic location of fuel breaks because they have been most effective where they provided access for firefighting activities.

  16. Factors affecting pesticide occurrence and transport in a large Midwestern river basin

    USGS Publications Warehouse

    Crawford, Charles G.

    2001-01-01

    Several factors affect the occurrence and transport of pesticides in surface waters of the 29,400 km2 White River Basin in Indiana. A relationship was found between pesticide use and the average annual concentration of that pesticide in the White River, although this relationship varies for different classes of pesticides. About one percent of the mass applied of each of the commonly used agricultural herbicides was transported from the basin via the White River. Peak pesticide concentrations were typically highest in late spring or early summer and were associated with periods of runoff following application. Concentrations of diazinon were higher in an urban basin than in two agricultural basins, corresponding to the common use of this insecticide on lawns and gardens in urban areas. Concentrations of atrazine, a corn herbicide widely used in the White River Basin, were higher in an agricultural basin with permeable, well-drained soils, than in an agricultural basin with less permeable, more poorly drained soils. Although use of butylate and cyanazine was comparable in the White River Basin between 1992 and 1994, concentrations in the White River of butylate, which is incorporated into soil, were substantially less than for cyanazine, which is typically applied to the soil surface.

  17. Microflora of soils under pine forests area affected by gradation of leaf-eating insects.

    PubMed

    Stremińska, Marta A; Błaszczyk, Mieczysław; Sierpińska, Alicja; Kolk, Andrzej

    2002-01-01

    Soils of pine forests in the Bytnica Forestry District, Poland, are poor in nutrients readily accessible to plants. The excessively acidic reaction of the soils, typical for soils under pine forests, unfavourably affects the growth of microorganisms whose numbers are lower than in soils under deciduous and mixed forests. In the pine forests of the studied forestry there were outbreaks of a defoliating insect - pine beauty moth (Panolis flammea L.), which resulted in over 60% defoliation of the trees. The studies were carried out on the area of tree stands subjected to gradation by leaf-eating insects (sprayed and not sprayed) and healthy stand of the same age class (age 60 to 70 years). The studies revealed increased number of soil microorganisms in samples taken from the area affected by pine beauty moth gradation in the case of both unsprayed areas and those sprayed with the pesticide. The occurrence in these soils of larger numbers of ammonifying and denitrifying bacteria points to the presence of conditions favouring the growth of heterotrophic organisms. Changes in the number of actinomycetes and fungi in soils under tree stands subjected to gradation by insects, compared to healthy stands, can be a consequence of a change of environmental conditions (e.g. % content of organic carbon). Soils under defoliated tree stands show higher biochemical activity related to nitrogen cycling in the pine forest ecosystem. This leads to higher availability of organic nitrogen for conversion to inorganic forms of nitrogen, which are utilised by trees. Further changes occurring in soils under forest stands affected by gradation by leaf-eating insects would allow to gain knowledge on the ecological consequences of the use of insecticides in the protection of pine stands against harmful insects, with particular stress on those situations in which pine stands not threatened by complete defoliation are sprayed.

  18. Knee osteoarthritis negatively affects the recovery step following large forward-directed postural perturbations.

    PubMed

    Pater, Mackenzie L; Rosenblatt, Noah J; Grabiner, Mark D

    2016-05-01

    The reasons for higher fall risk of people with osteoarthritis (OA) compared to people without OA are not known. It is possible that following a loss of balance OA may negatively affect the recovery stepping response. Stepping responses have not been reported for people with knee OA. Here, we compared recovery step kinematics following laboratory-induced trip and following a large treadmill-delivered perturbation simulating a trip between a group of women with and without self-reported knee OA. We hypothesized that knee OA would significantly impair recovery step kinematics compared to those of a control group. Following the laboratory-induced trip, step length and trunk flexion velocity at recovery step completion of women with OA were significantly impaired and more so for the women who fell. Following the treadmill-delivered perturbation, the recovery step kinematics of women with OA were not significantly impaired. For both perturbations, the women who fell had significantly impaired recovery step kinematics compared to those who did not fall, regardless of OA. The results are consistent with previous work on healthy middle aged and older women and suggest that the same biomechanical risk factors for trip-related falls are shared by middle age and older women regardless of the presence of knee OA. The results support the need to determine whether training protocols which have been shown to improve recovery step kinematics and reduce prospective falls by healthy older women can have similar outcomes for people with knee OA.

  19. Uniformity of large-area bilayer graphene grown by chemical vapor deposition

    NASA Astrophysics Data System (ADS)

    Sheng, Yuewen; Rong, Youmin; He, Zhengyu; Fan, Ye; Warner, Jamie H.

    2015-10-01

    Graphene grown by chemical vapor deposition (CVD) on copper foils is a viable method for large area films for transparent conducting electrode (TCE) applications. We examine the spatial uniformity of large area films on the centimeter scale when transferred onto both Si substrates with 300 nm oxide and flexible transparent polyethylene terephthalate substrates. A difference in the quality of graphene, as measured by the sheet resistance and transparency, is found for the areas at the edges of large sheets that depends on the supporting boat used for the CVD growth. Bilayer graphene is grown with uniform properties on the centimeter scale when a flat support is used for CVD growth. The flat support provides consistent delivery of precursor to the copper catalyst for graphene growth. These results provide important insights into the upscaling of CVD methods for growing high quality graphene and its transfer onto flexible substrates for potential applications as a TCE.

  20. Uniformity of large-area bilayer graphene grown by chemical vapor deposition.

    PubMed

    Sheng, Yuewen; Rong, Youmin; He, Zhengyu; Fan, Ye; Warner, Jamie H

    2015-10-01

    Graphene grown by chemical vapor deposition (CVD) on copper foils is a viable method for large area films for transparent conducting electrode (TCE) applications. We examine the spatial uniformity of large area films on the centimeter scale when transferred onto both Si substrates with 300 nm oxide and flexible transparent polyethylene terephthalate substrates. A difference in the quality of graphene, as measured by the sheet resistance and transparency, is found for the areas at the edges of large sheets that depends on the supporting boat used for the CVD growth. Bilayer graphene is grown with uniform properties on the centimeter scale when a flat support is used for CVD growth. The flat support provides consistent delivery of precursor to the copper catalyst for graphene growth. These results provide important insights into the upscaling of CVD methods for growing high quality graphene and its transfer onto flexible substrates for potential applications as a TCE. PMID:26349521

  1. Impact of substrate characteristics on performance of large area plasmonic photoconductive emitters.

    PubMed

    Yardimci, Nezih T; Salas, Rodolfo; Krivoy, Erica M; Nair, Hari P; Bank, Seth R; Jarrahi, Mona

    2015-12-14

    We present a comprehensive analysis of terahertz radiation from large area plasmonic photoconductive emitters in relation with characteristics of device substrate. Specifically, we investigate the radiation properties of large area plasmonic photoconductive emitters fabricated on GaAs substrates that exhibit short carrier lifetimes through low-temperature substrate growth and through epitaxially embedded rare-earth arsenide (ErAs and LuAs) nanoparticles in superlattice structures. Our analysis indicates that the utilized substrate composition and growth process for achieving short carrier lifetimes are crucial in determining substrate resistivity, carrier drift velocity, and carrier lifetime, which directly impact optical-to-terahertz conversion efficiency, radiation power, radiation bandwidth, and reliability of large area plasmonic photoconductive emitters.

  2. Large-Area Chemical and Biological Decontamination Using a High Energy Arc Lamp (HEAL) System.

    SciTech Connect

    Duty, Chad E; Smith, Rob R; Vass, Arpad Alexander; Ilgner, Ralph H; Brown, Gilbert M

    2008-01-01

    Methods for quickly decontaminating large areas exposed to chemical and biological (CB) warfare agents can present significant logistical, manpower, and waste management challenges. Oak Ridge National Laboratory (ORNL) is pursuing an alternate method to decompose CB agents without the use of toxic chemicals or other potentially harmful substances. This process uses a high energy arc lamp (HEAL) system to photochemically decompose CB agents over large areas (12 m2). Preliminary tests indicate that more than 5 decades (99.999%) of an Anthrax spore simulant (Bacillus globigii) were killed in less than 7 seconds of exposure to the HEAL system. When combined with a catalyst material (TiO2) the HEAL system was also effective against a chemical agent simulant, diisopropyl methyl phosphonate (DIMP). These results demonstrate the feasibility of a rapid, large-area chemical and biological decontamination method that does not require toxic or corrosive reagents or generate hazardous wastes.

  3. Design of a broadband ultra-large area acoustic cloak based on a fluid medium

    NASA Astrophysics Data System (ADS)

    Zhu, Jian; Chen, Tianning; Liang, Qingxuan; Wang, Xiaopeng; Jiang, Ping

    2014-10-01

    A broadband ultra-large area acoustic cloak based on fluid medium was designed and numerically implemented with homogeneous metamaterials according to the transformation acoustics. In the present work, fluid medium as the body of the inclusion could be tuned by changing the fluid to satisfy the variant acoustic parameters instead of redesign the whole cloak. The effective density and bulk modulus of the composite materials were designed to agree with the parameters calculated from the coordinate transformation methodology by using the effective medium theory. Numerical simulation results showed that the sound propagation and scattering signature could be controlled in the broadband ultra-large area acoustic invisibility cloak, and good cloaking performance has been achieved and physically realized with homogeneous materials. The broadband ultra-large area acoustic cloaking properties have demonstrated great potentials in the promotion of the practical applications of acoustic cloak.

  4. Open Skies aerial photography of selected areas in Central America affected by Hurricane Mitch

    USGS Publications Warehouse

    Molnia, Bruce; Hallam, Cheryl A.

    1999-01-01

    Between October 27 and November 1, 1998, Central America was devastated by Hurricane Mitch. Following a humanitarian relief effort, one of the first informational needs was complete aerial photographic coverage of the storm ravaged areas so that the governments of the affected countries, the U.S. agencies planning to provide assistance, and the international relief community could come to the aid of the residents of the devastated area. Between December 4 and 19, 1998 an Open Skies aircraft conducted five successful missions and obtained more than 5,000 high-resolution aerial photographs and more than 15,000 video images. The aerial data are being used by the Reconstruction Task Force and many others who are working to begin rebuilding and to help reduce the risk of future destruction.

  5. Source characterization of volatile organic compounds affecting the air quality in a coastal urban area of South Texas.

    PubMed

    Sanchez, Marciano; Karnae, Saritha; John, Kuruvilla

    2008-09-01

    Selected Volatile Organic Compounds (VOC) emitted from various anthropogenic sources including industries and motor vehicles act as primary precursors of ozone, while some VOC are classified as air toxic compounds. Significantly large VOC emission sources impact the air quality in Corpus Christi, Texas. This urban area is located in a semi-arid region of South Texas and is home to several large petrochemical refineries and industrial facilities along a busy ship-channel. The Texas Commission on Environmental Quality has setup two continuous ambient monitoring stations (CAMS 633 and 634) along the ship channel to monitor VOC concentrations in the urban atmosphere. The hourly concentrations of 46 VOC compounds were acquired from TCEQ for a comprehensive source apportionment study. The primary objective of this study was to identify and quantify the sources affecting the ambient air quality within this urban airshed. Principal Component Analysis/Absolute Principal Component Scores (PCA/APCS) was applied to the dataset. PCA identified five possible sources accounting for 69% of the total variance affecting the VOC levels measured at CAMS 633 and six possible sources affecting CAMS 634 accounting for 75% of the total variance. APCS identified natural gas emissions to be the major source contributor at CAMS 633 and it accounted for 70% of the measured VOC concentrations. The other major sources identified at CAMS 633 included flare emissions (12%), fugitive gasoline emissions (9%), refinery operations (7%), and vehicle exhaust (2%). At CAMS 634, natural gas sources were identified as the major source category contributing to 31% of the observed VOC. The other sources affecting this site included: refinery operations (24%), flare emissions (22%), secondary industrial processes (12%), fugitive gasoline emissions (8%) and vehicle exhaust (3%). PMID:19139530

  6. Source Characterization of Volatile Organic Compounds Affecting the Air Quality in a Coastal Urban Area of South Texas

    PubMed Central

    Sanchez, Marciano; Karnae, Saritha; John, Kuruvilla

    2008-01-01

    Selected Volatile Organic Compounds (VOC) emitted from various anthropogenic sources including industries and motor vehicles act as primary precursors of ozone, while some VOC are classified as air toxic compounds. Significantly large VOC emission sources impact the air quality in Corpus Christi, Texas. This urban area is located in a semi-arid region of South Texas and is home to several large petrochemical refineries and industrial facilities along a busy ship-channel. The Texas Commission on Environmental Quality has setup two continuous ambient monitoring stations (CAMS 633 and 634) along the ship channel to monitor VOC concentrations in the urban atmosphere. The hourly concentrations of 46 VOC compounds were acquired from TCEQ for a comprehensive source apportionment study. The primary objective of this study was to identify and quantify the sources affecting the ambient air quality within this urban airshed. Principal Component Analysis/Absolute Principal Component Scores (PCA/APCS) was applied to the dataset. PCA identified five possible sources accounting for 69% of the total variance affecting the VOC levels measured at CAMS 633 and six possible sources affecting CAMS 634 accounting for 75% of the total variance. APCS identified natural gas emissions to be the major source contributor at CAMS 633 and it accounted for 70% of the measured VOC concentrations. The other major sources identified at CAMS 633 included flare emissions (12%), fugitive gasoline emissions (9%), refinery operations (7%), and vehicle exhaust (2%). At CAMS 634, natural gas sources were identified as the major source category contributing to 31% of the observed VOC. The other sources affecting this site included: refinery operations (24%), flare emissions (22%), secondary industrial processes (12%), fugitive gasoline emissions (8%) and vehicle exhaust (3%). PMID:19139530

  7. Amylolytic hydrolysis of native starch granules affected by granule surface area.

    PubMed

    Kim, J C; Kong, B W; Kim, M J; Lee, S H

    2008-11-01

    Initial stage of hydrolysis of native starch granules with various amylolytic enzymes, alpha-amylase from Bacillus subtilis, glucoamylase I (GA-I) and II (GA-II) from Aspergillus niger, and beta-amylase from sweet potato showed that the reaction was apparently affected by a specific surface area of the starch granules. The ratios of the reciprocal of initial velocity of each amylolytic hydrolysis for native potato and maize starch to that for rice with the amylolytic enzymes were nearly equivalent to the ratio of surface area per mass of the 2 starch granules to that of rice, that is, 6.94 and 2.25, respectively. Thus, the reciprocal of initial velocity of each enzymatic hydrolysis as expressed in a Lineweaver-Burk plot was a linear function of the reciprocal of surface area for each starch granule. As a result, it is concluded that amylolytic hydrolysis of native starch granules is governed by the specific surface area, not by the mass concentration, of each granule. PMID:19021791

  8. Amylolytic hydrolysis of native starch granules affected by granule surface area.

    PubMed

    Kim, J C; Kong, B W; Kim, M J; Lee, S H

    2008-11-01

    Initial stage of hydrolysis of native starch granules with various amylolytic enzymes, alpha-amylase from Bacillus subtilis, glucoamylase I (GA-I) and II (GA-II) from Aspergillus niger, and beta-amylase from sweet potato showed that the reaction was apparently affected by a specific surface area of the starch granules. The ratios of the reciprocal of initial velocity of each amylolytic hydrolysis for native potato and maize starch to that for rice with the amylolytic enzymes were nearly equivalent to the ratio of surface area per mass of the 2 starch granules to that of rice, that is, 6.94 and 2.25, respectively. Thus, the reciprocal of initial velocity of each enzymatic hydrolysis as expressed in a Lineweaver-Burk plot was a linear function of the reciprocal of surface area for each starch granule. As a result, it is concluded that amylolytic hydrolysis of native starch granules is governed by the specific surface area, not by the mass concentration, of each granule.

  9. 110 GHz measurement of large-area graphene integrated in low-loss microwave structures

    NASA Astrophysics Data System (ADS)

    Skulason, H. S.; Nguyen, H. V.; Guermoune, A.; Sridharan, V.; Siaj, M.; Caloz, C.; Szkopek, T.

    2011-10-01

    We report high-frequency scattering parameter measurement of large-area monolayer graphene integrated on low-loss quartz substrates. High-quality graphene was grown by chemical vapour deposition on copper, chemically hole doped, and transferred to quartz. Microwave measurements were performed from 0.01 to 110 GHz. Simple microwave models were used to extract graphene impedance parameters. We find that contact resistance is effectively shunted above 3 GHz. Atomically thin large area graphene behaves as a wideband resistor with negligible kinetic inductance and negligible skin effect.

  10. System and method for interfacing large-area electronics with integrated circuit devices

    DOEpatents

    Verma, Naveen; Glisic, Branko; Sturm, James; Wagner, Sigurd

    2016-07-12

    A system and method for interfacing large-area electronics with integrated circuit devices is provided. The system may be implemented in an electronic device including a large area electronic (LAE) device disposed on a substrate. An integrated circuit IC is disposed on the substrate. A non-contact interface is disposed on the substrate and coupled between the LAE device and the IC. The non-contact interface is configured to provide at least one of a data acquisition path or control path between the LAE device and the IC.

  11. Electrochemical preparation of metal microstructures on large areas of etched ion track membranes

    NASA Astrophysics Data System (ADS)

    Dobrev, D.; Vetter, J.; Angert, N.

    1999-01-01

    A microgalvanic method for metal filling of etched ion tracks in organic foils on large areas is described. The method and the used galvanic cell permit the deposition of stable standing individual metal whiskers with high aspect ratio and a density of 10 5-10 8 per cm 2 on an area of 12.5 cm 2. The method was verified with copper and it is suitable also for various other metals. It can be applied for the replication of etched ion tracks and for the fabrication of microstructures containing large numbers of individual metal whiskers.

  12. Hybrid Ytterbium-doped large-mode-area photonic crystal fiber amplifier for long wavelengths.

    PubMed

    Petersen, Sidsel R; Alkeskjold, Thomas T; Poli, Federica; Coscelli, Enrico; Jørgensen, Mette M; Laurila, Marko; Lægsgaard, Jesper; Broeng, Jes

    2012-03-12

    A large-mode-area Ytterbium-doped photonic crystal fiber amplifier with build-in gain shaping is presented. The fiber cladding consists of a hexagonal lattice of air holes, where three rows are replaced with circular high-index inclusions. Seven missing air holes define the large-mode-area core. Light confinement is achieved by combined index and bandgap guiding, which allows for single-mode operation and gain shaping through distributed spectral filtering of amplified spontaneous emission. The fiber properties are ideal for amplification in the long wavelength regime of the Ytterbium gain spectrum above 1100 nm, and red shifting of the maximum gain to 1130 nm is demonstrated.

  13. A novel method for the activity measurement of large-area beta reference sources.

    PubMed

    Stanga, D; De Felice, P; Keightley, J; Capogni, M; Ioan, M R

    2016-03-01

    A novel method has been developed for the activity measurement of large-area beta reference sources. It makes use of two emission rate measurements and is based on the weak dependence between the source activity and the activity distribution for a given value of transmission coefficient. The method was checked experimentally by measuring the activity of two ((60)Co and (137)Cs) large-area reference sources constructed from anodized aluminum foils. Measurement results were compared with the activity values measured by gamma spectrometry. For each source, they agree within one standard uncertainty and also agree within the same limits with the certified values of the source activity. PMID:26701656

  14. An Analysis Methodology for the Gamma-ray Large Area Space Telescope

    NASA Technical Reports Server (NTRS)

    Morris, Robin D.; Cohen-Tanugi, Johann

    2004-01-01

    The Large Area Telescope (LAT) instrument on the Gamma Ray Large Area Space Telescope (GLAST) has been designed to detect high-energy gamma rays and determine their direction of incidence and energy. We propose a reconstruction algorithm based on recent advances in statistical methodology. This method, alternative to the standard event analysis inherited from high energy collider physics experiments, incorporates more accurately the physical processes occurring in the detector, and makes full use of the statistical information available. It could thus provide a better estimate of the direction and energy of the primary photon.

  15. Direct Observation of Highly Ordered Dendrimer Soft Building Blocks over a Large Area.

    PubMed

    Kwon, Kiok; Ok, Jong Min; Kim, Yun Ho; Kim, Jong-Seon; Jung, Woo-Bin; Cho, Soo-Yeon; Jung, Hee-Tae

    2015-11-11

    Developing large-area, single domain of organic soft-building blocks such as block copolymers, colloids, and supramolecular materials is one of the most important issues in the materials science and nanotechnology. Owing to their small sizes, complex molecular architectures, and high mobility, supramolecular materials are not well-suited for building large area, single domain structures. In the described study, a single domain of supramolecular columnar dendrimers was created over large area. The columnar structures in these domains have smaller (4.5 nm) diameters, higher area densities (ca. 36 Tera-dots/in(2)) and larger domains (>0.1 × 0.1 mm(2)) than those of all existing BCP and colloidal assemblies. By simply annealing dendrimer thin films between two flat solid surfaces, single domains of hexagonal columnar structures are created over large macroscopic areas. Observations made in this effort should serve as the foundation for the design of new routes for bottom-up lithography based on supramolecular building blocks.

  16. [100] or [110] aligned, semiconductor-based, large-area, flexible, electronic devices

    DOEpatents

    Goyal, Amit

    2015-03-24

    Novel articles and methods to fabricate the same resulting in flexible, large-area, [100] or [110] textured, semiconductor-based, electronic devices are disclosed. Potential applications of resulting articles are in areas of photovoltaic devices, flat-panel displays, thermophotovoltaic devices, ferroelectric devices, light emitting diode devices, computer hard disc drive devices, magnetoresistance based devices, photoluminescence based devices, non-volatile memory devices, dielectric devices, thermoelectric devices and quantum dot laser devices.

  17. Biological soil crusts emit large amounts of NO and HONO affecting the nitrogen cycle in drylands

    NASA Astrophysics Data System (ADS)

    Tamm, Alexandra; Wu, Dianming; Ruckteschler, Nina; Rodríguez-Caballero, Emilio; Steinkamp, Jörg; Meusel, Hannah; Elbert, Wolfgang; Behrendt, Thomas; Sörgel, Matthias; Cheng, Yafang; Crutzen, Paul J.; Su, Hang; Pöschl, Ulrich; Weber, Bettina

    2016-04-01

    to the latest IPCC report. In summary, our measurements show that dryland emissions of nitrogen oxides are largely driven by biocrusts and not by the underlying soil. As precipitation patterns, which influence biocrust activity, are affected by climate change, alterations in global nitrogen oxide emissions are to be expected. Thus, the role of biocrusts in the global cycling of reactive nitrogen needs to be followed and also implemented in regional and global models of biogeochemistry, air chemistry and climate.

  18. Fast and large-area growth of uniform MoS2 monolayers on molybdenum foils.

    PubMed

    Tai, Guoan; Zeng, Tian; Yu, Jin; Zhou, Jianxin; You, Yuncheng; Wang, Xufeng; Wu, Hongrong; Sun, Xu; Hu, Tingsong; Guo, Wanlin

    2016-01-28

    A controllable synthesis of two-dimensional crystal monolayers in a large area is a prerequisite for potential applications, but the growth of transition metal dichalcogenide monolayers in a large area with spatial homogeneity remains a great challenge. Here we report a novel and efficient method to fabricate large-scale MoS2 monolayers by direct sulfurization of pre-annealed molybdenum foil surfaces with large grain boundaries of more than 50 μm in size at elevated temperatures. Continuous MoS2 monolayers can be formed uniformly by sulfurizing the Mo foils in sulfur vapor at 600 °C within 1 min. At a lower temperature even down to 500 °C, uniform MoS2 monolayers can still be obtained but in a much longer sulfurizing duration. It is demonstrated that the formed monolayers can be nondestructively transferred onto arbitrary substrates by removing the Mo foil using diluted ferric chloride solution and can be successfully fabricated into photodetectors. The results show a novel avenue to efficiently fabricate two-dimensional crystals in a large area in a highly controllable way and should have great potential for the development of large-scale applications of two-dimensional crystals in electrophotonic systems.

  19. Fast and large-area growth of uniform MoS2 monolayers on molybdenum foils.

    PubMed

    Tai, Guoan; Zeng, Tian; Yu, Jin; Zhou, Jianxin; You, Yuncheng; Wang, Xufeng; Wu, Hongrong; Sun, Xu; Hu, Tingsong; Guo, Wanlin

    2016-01-28

    A controllable synthesis of two-dimensional crystal monolayers in a large area is a prerequisite for potential applications, but the growth of transition metal dichalcogenide monolayers in a large area with spatial homogeneity remains a great challenge. Here we report a novel and efficient method to fabricate large-scale MoS2 monolayers by direct sulfurization of pre-annealed molybdenum foil surfaces with large grain boundaries of more than 50 μm in size at elevated temperatures. Continuous MoS2 monolayers can be formed uniformly by sulfurizing the Mo foils in sulfur vapor at 600 °C within 1 min. At a lower temperature even down to 500 °C, uniform MoS2 monolayers can still be obtained but in a much longer sulfurizing duration. It is demonstrated that the formed monolayers can be nondestructively transferred onto arbitrary substrates by removing the Mo foil using diluted ferric chloride solution and can be successfully fabricated into photodetectors. The results show a novel avenue to efficiently fabricate two-dimensional crystals in a large area in a highly controllable way and should have great potential for the development of large-scale applications of two-dimensional crystals in electrophotonic systems. PMID:26743938

  20. Satellite based classification (haze, fog) and affected area estimation over Indo - Pak Sub-Continent

    NASA Astrophysics Data System (ADS)

    Ghauri, Badar; Zafar, Sumaira

    2016-07-01

    Northern Pakistan and bordering Indian Punjab experience intense smog and fog during fall and winters. Environmentalists have been raising their voices over the situation and demanded control over regional emissions to save the livelihood of millions of dwellers whose trade, commerce and agriculture is at stake because of long smog/ fog spells.. This paper estimates the area affected by haze, smog and fog during 2006- 2010. MODIS (geo-referenced MODIS subsets India1, 2 &3) of the area in Pakistan and India from 2006 to 2010 for the period October to February) were analyzed using state of the art software ENVI 4.2 and ArcGIS 10.2. This process resulted in area belonging to each class that is; haze, smog and fog. On the basis of density, haze and fog cover was determined. Variations in fog cover, its density and identification of location of fog initiation process were also determined using near real time (30 minutes) METEOSAT-7 IODC data where actually fog formation started and then extended to the area of favorable conditions. Haze has been noticed to intensify due to massive burning of agricultural waste (rice husk) in India and Pakistan towards the end of October each year. MODIS thermal anomalies/fire data (MYD 14) were also used to verify this activity on the ground, which results in hazy conditions at regional level during fall months. Haze-affected area during 2006 to 2010 in Pakistan ranged from 155,000 Km2 to 354,000 Km2 and in India it ranged from 333,000 Km2 to 846,000 Km2. Similarly winter fog cover during this period in Pakistan varied from 136,000 Km2 to 381,000 Km2 and in India it was estimated at 327,000 Km2 to 566,000 Km2. This phenomenon was more prominent in India than in Pakistan where and fog cover was at least twice than that was observed in Pakistan. It has been noted that area covered by fog, smog and haze doubled during the study period in the region. Atmospheric dimming during autumn/ fall also reduces the mixing height leading to greater

  1. Children's Mental Health in the Area Affected by the Hebei Spirit Oil Spill Accident

    PubMed Central

    Jeong, Woo-Chul; Lim, Myungho; Kwon, Hojang; Choi, Yeyong; Yoo, Seung-Jin; Noh, Su Ryun; Cheong, Hae-Kwan

    2013-01-01

    Objectives Children are one of the most vulnerable populations to the impact of disasters. We aimed to examine children's mental health in the area affected by the Hebei Spirit oil spill accident on December 7, 2007. Methods A cross-sectional questionnaire survey was conducted using the Korean versions of the Children's Depression Inventory and State Anxiety Inventory for Children on 1,362 children attending elementary schools in the affected area. The information on distances between the nearest contaminated coastline to the child's residential house or attending school were obtained using a web-based map by inputting two address points. The symptom risks of depression and state anxiety were estimated by multiple logistic regression analyses adjusted for age, gender, and other covariates. Results Children with the closest distance (in the fourth quartile) to the school from the contaminated coastline showed a significantly higher symptom risk of depression compared to those with the farthest distance (first quartile)(odds ratio, 2.73; 95% confidence interval, 1.40-5.33), while there was no significant association between anxiety symptoms and distance. Conclusions Children, a vulnerable population for mental health impact by the oil spill accident, should be included in mental health programs in the community along with their family as victims of the disaster. PMID:24010065

  2. Major factors affecting in situ biodegradation rates of jet-fuel during large-scale biosparging project in sedimentary bedrock.

    PubMed

    Machackova, Jirina; Wittlingerova, Zdena; Vlk, Kvetoslav; Zima, Jaroslav

    2012-01-01

    Biodegradation of petroleum hydrocarbons (TPH), mainly jet fuel, had taken place at the former Soviet Army air base in the Czech Republic. The remediation of large-scale petroleum contamination of soil and groundwater has provided valuable information about biosparging efficiency in the sandstone sedimentary bedrock. In 1997 petroleum contamination was found to be present in soil and groundwater across an area of 28 hectares, divided for the clean-up purpose into smaller clean-up fields (several hectares). The total estimated quantity of TPH released to the environment was about 7,000 metric tons. Biosparging was applied as an innovative clean-up technology at the site and was operated over a 10-year period (1997-2008). Importance of a variety of factors that affect bacterial activity in unsaturated and saturated zones was widely studied on the site and influence of natural and technological factors on clean-up efficiency in heavily contaminates areas of clean-up fields (initial contaminant mass 111-452 metric ton/ha) was evaluated. Long-term monitoring of the groundwater temperature has shown seasonal rises and falls of temperature which have caused a fluctuation in biodegradation activity during clean-up. By contrast, an overall rise of average groundwater temperature was observed in the clean-up fields, most probably as a result of the biological activity during the clean-up process. The significant rise of biodegradation rates, observed after air sparging intensification, and strong linear correlation between the air injection rates and biodegradation activities have shown that the air injection rate is the principal factor in biodegradation efficiency in heavily contaminated areas. It has a far more important role for achieving a biodegradation activity than the contamination content which appeared to have had only a slight effect after the removal of about 75% of initial contamination.

  3. How Venus surface conditions evolution can be affected by large impacts at long timescales?

    NASA Astrophysics Data System (ADS)

    Gillmann, Cedric; Golabek, Gregor; Tackley, Paul

    2016-04-01

    Using numerical simulations, we investigate how the evolution of Venus' atmosphere and mantle is modified by large impacts, during Late Veneer and Late Heavy Bombardment. We propose a coupled model of mantle/atmosphere feedback. We also focus on volatile fluxes in and out of the atmosphere: atmospheric escape and degassing. The solid part of the planet is simulated using the StagYY code (Armann and Tackley, 2012) and releases volatiles into the atmosphere through degassing. Physical properties are depth-dependent. The assumed rheology is Newtonian diffusion creep plus plastic yielding. Atmospheric escape modeling involves two different aspects: hydrodynamic escape (0-500 Myr) and non-thermal escape mechanisms (dominant post 4 Ga). Hydrodynamic escape is the massive outflow of volatiles occurring when the solar energy input is strong. Post 4 Ga escape from non-thermal processes is comparatively low. The evolution of surface temperature is calculated from the greenhouse effect dependent on CO2 and water concentrations in the atmosphere, using a one-dimensional gray radiative-convective atmosphere model. It allows us to complete the coupling of the model: feedback of the atmosphere on the mantle is obtained by using surface temperature as a boundary condition for the convection. Large impacts are capable of contributing to (i) atmospheric escape, (ii) volatile replenishment and (iii) energy transfer to the mantle of the solid planet. We test a wide range of impactor parameters (size, velocity, timing) and different assumptions related to impact erosion (Shuvalov, 2010). For energy transfer, 2D distribution of the thermal anomaly created by the impact is used, leading to melting and subjected to transport by the mantle convection. Small (0-50 km) meteorites have a negligible effect on the global scale: they only affect the impact point and do not have lasting consequences on surface conditions. Medium ones (50-150 km) have strong short term influence through volatile

  4. A large-scale deforestation experiment: Effects of patch area and isolation on Amazon birds

    USGS Publications Warehouse

    Ferraz, G.; Nichols, J.D.; Hines, J.E.; Stouffer, P.C.; Bierregaard, R.O.; Lovejoy, T.E.

    2007-01-01

    As compared with extensive contiguous areas, small isolated habitat patches lack many species. Some species disappear after isolation; others are rarely found in any small patch, regardless of isolation. We used a 13-year data set of bird captures from a large landscape-manipulation experiment in a Brazilian Amazon forest to model the extinction-colonization dynamics of 55 species and tested basic predictions of island biogeography and metapopulation theory. From our models, we derived two metrics of species vulnerability to changes in isolation and patch area. We found a strong effect of area and a variable effect of isolation on the predicted patch occupancy by birds.

  5. Study on the spatiotemporal variability and affecting factors in soil moisture at a humid area

    NASA Astrophysics Data System (ADS)

    Liu, H.; Yu, Z.

    2008-12-01

    The spatiotemporal variability of soil moisture and its affecting factors in a humid area were examined based on the field measuring date in the Tai lake drainage basin, China. 24 sensors near the soil surface and 12 sensors in 2 profiles (6 in each) were set up for collecting hourly soil moisture data with the Frequency Domain Reflectometry (FDR) sensors in 2006. Coefficient of variation (CV) and semi-variogram were calculated to evaluate the temporal variability in different locations and the spatial variability in different periods. The surface soil moisture appears middle or weak variability, and most of the CV values are in the range of 0.13-0.26. Soil characteristics, topography, vegetation, meteorological factors and human activities influenced the soil moisture spatiotemporal variability significantly. The factors appear having different affecting abilities on the spatiotemporal variability, and the domain factors are different in four seasons. Soil characteristics mainly influence the temporal variability in the scale of hill slope. Coarser texture on the upper part of the slope results in a larger variability. Topography and micro-topography affects the spatial variability in all 3 dimensions. The variability is larger at upper locations and chine of the slope. The effect of vegetation on the soil moisture variability is stronger in spring, summer, and autumn than in winter, according to the different growth activities and water demand. The trees on the slope influence the CV values along the slope. Meteorological factors are the forcing factors of the soil water variation. Higher rainfall and evaporation variations produce higher variability in soil moisture while the rainfall has more influence in the summer and the evaporation has more in the fall. The results provide better understanding of soil moisture variation and base for further study on how the soil moisture variation could affect the rainfall runoff partitioning.

  6. Independent Peer Evaluation of the Large Area Crop Inventory Experiment (LACIE): The LACIE Symposium

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Yield models and crop estimate accuracy are discussed within the Large Area Crop Inventory Experiment. The wheat yield estimates in the United States, Canada, and U.S.S.R. are emphasized. Experimental results design, system implementation, data processing systems, and applications were considered.

  7. Ultra-low thermal conductivities in large-area Si-Ge nanomeshes for thermoelectric applications.

    PubMed

    Perez-Taborda, Jaime Andres; Muñoz Rojo, Miguel; Maiz, Jon; Neophytou, Neophytos; Martin-Gonzalez, Marisol

    2016-01-01

    In this work, we measure the thermal and thermoelectric properties of large-area Si0.8Ge0.2 nano-meshed films fabricated by DC sputtering of Si0.8Ge0.2 on highly ordered porous alumina matrices. The Si0.8Ge0.2 film replicated the porous alumina structure resulting in nano-meshed films. Very good control of the nanomesh geometrical features (pore diameter, pitch, neck) was achieved through the alumina template, with pore diameters ranging from 294 ± 5nm down to 31 ± 4 nm. The method we developed is able to provide large areas of nano-meshes in a simple and reproducible way, being easily scalable for industrial applications. Most importantly, the thermal conductivity of the films was reduced as the diameter of the porous became smaller to values that varied from κ = 1.54 ± 0.27 W K(-1)m(-1), down to the ultra-low κ = 0.55 ± 0.10 W K(-1)m(-1) value. The latter is well below the amorphous limit, while the Seebeck coefficient and electrical conductivity of the material were retained. These properties, together with our large area fabrication approach, can provide an important route towards achieving high conversion efficiency, large area, and high scalable thermoelectric materials. PMID:27650202

  8. Ultra-low thermal conductivities in large-area Si-Ge nanomeshes for thermoelectric applications

    PubMed Central

    Perez-Taborda, Jaime Andres; Muñoz Rojo, Miguel; Maiz, Jon; Neophytou, Neophytos; Martin-Gonzalez, Marisol

    2016-01-01

    In this work, we measure the thermal and thermoelectric properties of large-area Si0.8Ge0.2 nano-meshed films fabricated by DC sputtering of Si0.8Ge0.2 on highly ordered porous alumina matrices. The Si0.8Ge0.2 film replicated the porous alumina structure resulting in nano-meshed films. Very good control of the nanomesh geometrical features (pore diameter, pitch, neck) was achieved through the alumina template, with pore diameters ranging from 294 ± 5nm down to 31 ± 4 nm. The method we developed is able to provide large areas of nano-meshes in a simple and reproducible way, being easily scalable for industrial applications. Most importantly, the thermal conductivity of the films was reduced as the diameter of the porous became smaller to values that varied from κ = 1.54 ± 0.27 W K−1m−1, down to the ultra-low κ = 0.55 ± 0.10 W K−1m−1 value. The latter is well below the amorphous limit, while the Seebeck coefficient and electrical conductivity of the material were retained. These properties, together with our large area fabrication approach, can provide an important route towards achieving high conversion efficiency, large area, and high scalable thermoelectric materials. PMID:27650202

  9. Homeless Students and Academic Achievement: Evidence from a Large Urban Area

    ERIC Educational Resources Information Center

    Tobin, Kerri J.

    2016-01-01

    Child homelessness has recently reached levels unprecedented in the United States since the Great Depression. Contemporary research has attempted to isolate the effects of homelessness on education, with mixed results. This study reports results from a study in one large urban area and finds that there is no meaningful difference in achievement…

  10. Dust Sensor with Large Detection Area Using Polyimide Film and Piezoelectric Elements

    NASA Astrophysics Data System (ADS)

    Kobayashi, M.; Okudaira, O.; Kurosawa, K.; Okamoto, T.; Matsui, T.

    2016-10-01

    We describe the development of dust particles sensor in space with large area (1m × 1m scale). The sensor has just a thin film of polyimide attached with small tips of piezoelectric elements. We performed experiments to characterize the sensor.

  11. LARGE AREA LAND COVER MAPPING THROUGH SCENE-BASED CLASSIFICATION COMPOSITING

    EPA Science Inventory

    Over the past decade, a number of initiatives have been undertaken to create definitive national and global data sets consisting of precision corrected Landsat MSS and TM scenes. One important application of these data is the derivation of large area land cover products spanning ...

  12. Transformational, Large Area Fabrication of Nanostructured Materials Using Plasma Arc Lamps

    SciTech Connect

    2009-03-01

    This factsheet describes a study that will address critical additional steps over large areas of as-synthesized nanostructured materials, such as annealing, phase transformation, or activation of dopants, dramatically reducing the processing costs of the solid-state lighting and photovoltaic materials.

  13. Ultra-low thermal conductivities in large-area Si-Ge nanomeshes for thermoelectric applications.

    PubMed

    Perez-Taborda, Jaime Andres; Muñoz Rojo, Miguel; Maiz, Jon; Neophytou, Neophytos; Martin-Gonzalez, Marisol

    2016-09-21

    In this work, we measure the thermal and thermoelectric properties of large-area Si0.8Ge0.2 nano-meshed films fabricated by DC sputtering of Si0.8Ge0.2 on highly ordered porous alumina matrices. The Si0.8Ge0.2 film replicated the porous alumina structure resulting in nano-meshed films. Very good control of the nanomesh geometrical features (pore diameter, pitch, neck) was achieved through the alumina template, with pore diameters ranging from 294 ± 5nm down to 31 ± 4 nm. The method we developed is able to provide large areas of nano-meshes in a simple and reproducible way, being easily scalable for industrial applications. Most importantly, the thermal conductivity of the films was reduced as the diameter of the porous became smaller to values that varied from κ = 1.54 ± 0.27 W K(-1)m(-1), down to the ultra-low κ = 0.55 ± 0.10 W K(-1)m(-1) value. The latter is well below the amorphous limit, while the Seebeck coefficient and electrical conductivity of the material were retained. These properties, together with our large area fabrication approach, can provide an important route towards achieving high conversion efficiency, large area, and high scalable thermoelectric materials.

  14. Ultra-low thermal conductivities in large-area Si-Ge nanomeshes for thermoelectric applications

    NASA Astrophysics Data System (ADS)

    Perez-Taborda, Jaime Andres; Muñoz Rojo, Miguel; Maiz, Jon; Neophytou, Neophytos; Martin-Gonzalez, Marisol

    2016-09-01

    In this work, we measure the thermal and thermoelectric properties of large-area Si0.8Ge0.2 nano-meshed films fabricated by DC sputtering of Si0.8Ge0.2 on highly ordered porous alumina matrices. The Si0.8Ge0.2 film replicated the porous alumina structure resulting in nano-meshed films. Very good control of the nanomesh geometrical features (pore diameter, pitch, neck) was achieved through the alumina template, with pore diameters ranging from 294 ± 5nm down to 31 ± 4 nm. The method we developed is able to provide large areas of nano-meshes in a simple and reproducible way, being easily scalable for industrial applications. Most importantly, the thermal conductivity of the films was reduced as the diameter of the porous became smaller to values that varied from κ = 1.54 ± 0.27 W K‑1m‑1, down to the ultra-low κ = 0.55 ± 0.10 W K‑1m‑1 value. The latter is well below the amorphous limit, while the Seebeck coefficient and electrical conductivity of the material were retained. These properties, together with our large area fabrication approach, can provide an important route towards achieving high conversion efficiency, large area, and high scalable thermoelectric materials.

  15. Improve large area uniformity and production capacity of laser interference lithography with beam flattening device

    NASA Astrophysics Data System (ADS)

    Yang, Yin-Kuang; Wu, Yu-Xiang; Lin, Te-Hsun; Yu, Chun-Wen; Fu, Chien-Chung

    2016-03-01

    Laser interference lithography (LIL) is a maskless lithography technique with many advantages such as simple optical design, inexpensive, infinite depth of focus, and large area patterning with single exposure. However, the intensity of normal laser beam is Gaussian distribution. In order to obtain large area uniform structure, we have to expand the laser beam much bigger than the wafer and use only the center part of the beam. Resulting in wasting lots of energy and the production capacity decrease. In this study, we designed a beam shaping device which consists of two parallel fused silicon optical window with different coating on both side. Two optical window form an air thin film. When the expanded laser beam pass through the device, the beam will experience many refraction and reflection between two optical window and interference with each other. The transmittance of laser beam will depend on the incident angle. The output intensity distribution will change from Gaussian distribution to a flat top distribution. In our experiment, we combined the beam shaping device with a Lloyd's mirror LIL system. Experiment results indicated that the LIL system with beam shaping device can obtain large area uniform pattern. And compare with the traditional Lloyd's mirror LIL system, the exposure time is shorten up to 4.5 times. In conclusion, this study design a beam flattening device for LIL system. The flat top beam can improve the large area uniformity and the production capacity of LIL. Making LIL more suitable for industry application.

  16. Laser interference lithography for large area patterning and the fabrication of functional nanostructures

    NASA Astrophysics Data System (ADS)

    Wathuthanthri, Ishan

    Nature-inspired phenomena such as the "moth eye" and "lotus leaf" effects have gained a lot of interest in recent years due to potential applications in a wide range of scientific and engineering disciplines. To practically achieve a majority of these biomimetic applications it is necessary to fabricate such nano-featured surfaces in a low-cost and high-throughput manner. To this end, this dissertation focuses on developing and using the Interference Lithography (IL) technologies to achieve large-area nanopatterning. IL is a parallel-type nanolithography technique that shares many of the advantages of other parallel-type techniques such as deep-UV photolithography while alleviating a majority of concerns such as cost and complexity. IL relies on the interference of two or more beams of light where the resulting interference fringes are generally recorded on a light sensitive polymeric material such as photoresist. In simple two-beam IL systems, the periodicity of the interference fringes is simply a function of wavelength and the angle of separation of the two beams, while the maximum coverage area is a constrained by the optical path and the exposed area. To this extent, in the design of interferometers for nanopatterning, the challenge remains in designing systems where a simple mechanism exists for varying the angle of separation of the interfering beams and in turn periodicity of the interference fringes while also enabling large-area exposures. To this end, the first half of this dissertation demonstrates three different IL systems (Lloyd-mirror, two-degree-of freedom Lloyd-mirror, and the tunable two-mirror systems) designed and established at Stevens capable of fast tuning of periodicities while also achieving wafer-scale (4") large-area nanopatterning. Using the large-area nanopatterns of photoresist, various pattern transfer techniques have also been investigated where the photoresist film is used as a template layer to transfer the large-area periodic

  17. Mapping regional patterns of large forest fires in Wildland-Urban Interface areas in Europe.

    PubMed

    Modugno, Sirio; Balzter, Heiko; Cole, Beth; Borrelli, Pasquale

    2016-05-01

    Over recent decades, Land Use and Cover Change (LUCC) trends in many regions of Europe have reconfigured the landscape structures around many urban areas. In these areas, the proximity to landscape elements with high forest fuels has increased the fire risk to people and property. These Wildland-Urban Interface areas (WUI) can be defined as landscapes where anthropogenic urban land use and forest fuel mass come into contact. Mapping their extent is needed to prioritize fire risk control and inform local forest fire risk management strategies. This study proposes a method to map the extent and spatial patterns of the European WUI areas at continental scale. Using the European map of WUI areas, the hypothesis is tested that the distance from the nearest WUI area is related to the forest fire probability. Statistical relationships between the distance from the nearest WUI area, and large forest fire incidents from satellite remote sensing were subsequently modelled by logistic regression analysis. The first European scale map of the WUI extent and locations is presented. Country-specific positive and negative relationships of large fires and the proximity to the nearest WUI area are found. A regional-scale analysis shows a strong influence of the WUI zones on large fires in parts of the Mediterranean regions. Results indicate that the probability of large burned surfaces increases with diminishing WUI distance in touristic regions like Sardinia, Provence-Alpes-Côte d'Azur, or in regions with a strong peri-urban component as Catalunya, Comunidad de Madrid, Comunidad Valenciana. For the above regions, probability curves of large burned surfaces show statistical relationships (ROC value > 0.5) inside a 5000 m buffer of the nearest WUI. Wise land management can provide a valuable ecosystem service of fire risk reduction that is currently not explicitly included in ecosystem service valuations. The results re-emphasise the importance of including this ecosystem service

  18. Mapping regional patterns of large forest fires in Wildland-Urban Interface areas in Europe.

    PubMed

    Modugno, Sirio; Balzter, Heiko; Cole, Beth; Borrelli, Pasquale

    2016-05-01

    Over recent decades, Land Use and Cover Change (LUCC) trends in many regions of Europe have reconfigured the landscape structures around many urban areas. In these areas, the proximity to landscape elements with high forest fuels has increased the fire risk to people and property. These Wildland-Urban Interface areas (WUI) can be defined as landscapes where anthropogenic urban land use and forest fuel mass come into contact. Mapping their extent is needed to prioritize fire risk control and inform local forest fire risk management strategies. This study proposes a method to map the extent and spatial patterns of the European WUI areas at continental scale. Using the European map of WUI areas, the hypothesis is tested that the distance from the nearest WUI area is related to the forest fire probability. Statistical relationships between the distance from the nearest WUI area, and large forest fire incidents from satellite remote sensing were subsequently modelled by logistic regression analysis. The first European scale map of the WUI extent and locations is presented. Country-specific positive and negative relationships of large fires and the proximity to the nearest WUI area are found. A regional-scale analysis shows a strong influence of the WUI zones on large fires in parts of the Mediterranean regions. Results indicate that the probability of large burned surfaces increases with diminishing WUI distance in touristic regions like Sardinia, Provence-Alpes-Côte d'Azur, or in regions with a strong peri-urban component as Catalunya, Comunidad de Madrid, Comunidad Valenciana. For the above regions, probability curves of large burned surfaces show statistical relationships (ROC value > 0.5) inside a 5000 m buffer of the nearest WUI. Wise land management can provide a valuable ecosystem service of fire risk reduction that is currently not explicitly included in ecosystem service valuations. The results re-emphasise the importance of including this ecosystem service

  19. Large area strain analysis using scanning transmission electron microscopy across multiple images

    SciTech Connect

    Oni, A. A.; Sang, X.; LeBeau, J. M.; Raju, S. V.; Saxena, S.; Dumpala, S.; Broderick, S.; Rajan, K.; Kumar, A.; Sinnott, S.

    2015-01-05

    Here, we apply revolving scanning transmission electron microscopy to measure lattice strain across a sample using a single reference area. To do so, we remove image distortion introduced by sample drift, which usually restricts strain analysis to a single image. Overcoming this challenge, we show that it is possible to use strain reference areas elsewhere in the sample, thereby enabling reliable strain mapping across large areas. As a prototypical example, we determine the strain present within the microstructure of a Ni-based superalloy directly from atom column positions as well as geometric phase analysis. While maintaining atomic resolution, we quantify strain within nanoscale regions and demonstrate that large, unit-cell level strain fluctuations are present within the intermetallic phase.

  20. The Anti-Coincidence Detector for the GLAST Large Area Telescope

    SciTech Connect

    Moiseev, A.A.; Hartman, R.C.; Ormes, J.F.; Thompson, D.J.; Amato, M.J.; Johnson, T.E.; Segal, K.N.; Sheppard, D.A.

    2007-03-23

    This paper describes the design, fabrication and testing of the Anti-Coincidence Detector (ACD) for the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT). The ACD is LAT's first-level defense against the charged cosmic ray background that outnumbers the gamma rays by 3-5 orders of magnitude. The ACD covers the top and 4 sides of the LAT tracking detector, requiring a total active area of {approx}8.3 square meters. The ACD detector utilizes plastic scintillator tiles with wave-length shifting fiber readout. In order to suppress self-veto by shower particles at high gamma-ray energies, the ACD is segmented into 89 tiles of different sizes. The overall ACD efficiency for detection of singly charged relativistic particles entering the tracking detector from the top or sides of the LAT exceeds the required 0.9997.

  1. Toward Large-Area Sub-Arcsecond X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    O'Dell, Stephen L.; Aldcroft, Thomas L.; Allured, Ryan; Atkins, Carolyn; Burrows, David N.; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Cotroneo, Vincenzo; Elsner, Ronald F.; Graham, Michael E.; Gubarev, Mikhail V.; Heilmann, Ralf K.; Johnson-Wilke, Raegan L.; Kilaru, Kiranmayee; Kolodziejczak, Jeffrey J.; McMuldroch, Stuart; Ramsey, Brian D.; Reid, Paul B.; Riveros, Raul E.; Roche, Jacqueline M.; Saha, Timo T.; Schattenburg, Mark L.; Schwartz, Daniel A.; Trolier-McKinstry, Susan E.; Ulmer, Melville P.; Vaynman, Semyon; Vikhlinin, Alexey; Wang, Xiaoli; Weisskopf, Martin C.; Wilke, Rudeger H. T.; Zhang, William W.

    2014-01-01

    The future of x-ray astronomy depends upon development of x-ray telescopes with larger aperture areas (>1 sq m) and finer angular resolution(<1).Combined with the special requirements of nested grazing incidence optics, the mass and envelope constraints of spaceborne telescopes render such advances technologically challenging. Achieving this goal will require precision fabrication, alignment, mounting, and assembly of large areas (>100 sq m) of lightweight (1 kg/sq m areal density) high quality mirrors-possibly entailing active (in-space adjustable) alignment and figure correction. This paper discusses relevant programmatic and technological issues and summarizes progress toward large area sub-arcsecond x-ray telescopes. Key words: X-ray telescopes, x-ray optics, active optics, electroactive devices, silicon mirrors, differential deposition, ion implantation.

  2. Large-area semi-transparent light-sensitive nanocrystal skins.

    PubMed

    Akhavan, Shahab; Guzelturk, Burak; Sharma, Vijay Kumar; Demir, Hilmi Volkan

    2012-11-01

    We report a large-area, semi-transparent, light-sensitive nanocrystal skin (LS-NS) platform consisting of single monolayer colloidal nanocrystals. LS-NS devices, which were fabricated over areas up to 48 cm(2) using spray-coating and several cm-squares using dip-coating, are operated on the principle of photogenerated potential buildup, unlike the conventional charge collection. Implementing proof-of-concept devices using CdTe nanocrystals with ligand removal, we observed a substantial sensitivity enhancement factor of ~73%, accompanied with a 3-fold faster response time (<100 ms). With fully sealed nanocrystal monolayers, LS-NS is found to be highly stable under ambient conditions, promising for low-cost large-area UV/visible sensing in windows and facades of smart buildings. PMID:23187342

  3. Large-Area Synthesis of High-Quality Uniform Few-Layer MoTe2.

    PubMed

    Zhou, Lin; Xu, Kai; Zubair, Ahmad; Liao, Albert D; Fang, Wenjing; Ouyang, Fangping; Lee, Yi-Hsien; Ueno, Keiji; Saito, Riichiro; Palacios, Tomás; Kong, Jing; Dresselhaus, Mildred S

    2015-09-23

    The controlled synthesis of large-area, atomically thin molybdenum ditelluride (MoTe2) crystals is crucial for its various applications based on the attractive properties of this emerging material. In this work, we developed a chemical vapor deposition synthesis to produce large-area, uniform, and highly crystalline few-layer 2H and 1T' MoTe2 films. It was found that these two different phases of MoTe2 can be grown depending on the choice of Mo precursor. Because of the highly crystalline structure, the as-grown few-layer 2H MoTe2 films display electronic properties that are comparable to those of mechanically exfoliated MoTe2 flakes. Our growth method paves the way for the large-scale application of MoTe2 in high-performance nanoelectronics and optoelectronics. PMID:26305492

  4. Very Large Area/Volume Microwave ECR Plasma and Ion Source

    NASA Technical Reports Server (NTRS)

    Foster, John E. (Inventor); Patterson, Michael J. (Inventor)

    2009-01-01

    The present invention is an apparatus and method for producing very large area and large volume plasmas. The invention utilizes electron cyclotron resonances in conjunction with permanent magnets to produce dense, uniform plasmas for long life ion thruster applications or for plasma processing applications such as etching, deposition, ion milling and ion implantation. The large area source is at least five times larger than the 12-inch wafers being processed to date. Its rectangular shape makes it easier to accommodate to materials processing than sources that are circular in shape. The source itself represents the largest ECR ion source built to date. It is electrodeless and does not utilize electromagnets to generate the ECR magnetic circuit, nor does it make use of windows.

  5. Degenerate four wave mixing in large mode area hybrid photonic crystal fibers.

    PubMed

    Petersen, Sidsel R; Alkeskjold, Thomas T; Lægsgaard, Jesper

    2013-07-29

    Spontaneous degenerate four wave mixing (FWM) is investigated in large mode area hybrid photonic crystal fibers, in which photonic bandgap guidance and index guidance is combined. Calculations show the parametric gain is maximum on the edge of a photonic bandgap, for a large range of pump wavelengths. The FWM products are observed on the edges of a transmission band experimentally, in good agreement with the numerical results. Thereby the bandedges can be used to control the spectral positions of FWM products through a proper fiber design. The parametric gain control combined with a large mode area fiber design potentially allows for power scaling of light at wavelengths not easily accessible with e.g. rare earth ions. PMID:23938682

  6. Large-area high-quality graphene on Ge(001)/Si(001) substrates.

    PubMed

    Pasternak, I; Dabrowski, P; Ciepielewski, P; Kolkovsky, V; Klusek, Z; Baranowski, J M; Strupinski, W

    2016-06-01

    Various experimental data revealing large-area high-quality graphene films grown by the CVD method on Ge(001)/Si(001) substrates are presented. SEM images have shown that the structure of nano-facets is formed on the entire surface of Ge(001), which is covered by a graphene layer over the whole macroscopic sample surface of 1 cm(2). The hill-and-valley structures are positioned 90° to each other and run along the <100> direction. The hill height in relation to the valley measured by STM is about 10 nm. Raman measurements have shown that a uniform graphene monolayer covers the nano-facet structures on the Ge(001) surface. Raman spectroscopy has also proved that the grown graphene monolayer is characterized by small strain variations and minimal charge fluctuations. Atomically resolved STM images on the hills of the nanostructures on the Ge(001) surface have confirmed the presence of a graphene monolayer. In addition, the STS/CITS maps show that high-quality graphene has been obtained on such terraces. The subsequent coalescence of graphene domains has led to a relatively well-oriented large-area layer. This is confirmed by LEED measurements, which have indicated that two orientations are preferable in the grown large-area graphene monolayer. The presence of large-area coverage by graphene has been also confirmed by low temperature Hall measurements of a macroscopic sample, showing an n-type concentration of 9.3 × 10(12) cm(-2) and a mobility of 2500 cm(2) V(-1) s(-1). These important characteristic features of graphene indicate a high homogeneity of the layer grown on the large area Ge(001)/Si(001) substrates. PMID:27189131

  7. Large-area high-quality graphene on Ge(001)/Si(001) substrates

    NASA Astrophysics Data System (ADS)

    Pasternak, I.; Dabrowski, P.; Ciepielewski, P.; Kolkovsky, V.; Klusek, Z.; Baranowski, J. M.; Strupinski, W.

    2016-05-01

    Various experimental data revealing large-area high-quality graphene films grown by the CVD method on Ge(001)/Si(001) substrates are presented. SEM images have shown that the structure of nano-facets is formed on the entire surface of Ge(001), which is covered by a graphene layer over the whole macroscopic sample surface of 1 cm2. The hill-and-valley structures are positioned 90° to each other and run along the <100> direction. The hill height in relation to the valley measured by STM is about 10 nm. Raman measurements have shown that a uniform graphene monolayer covers the nano-facet structures on the Ge(001) surface. Raman spectroscopy has also proved that the grown graphene monolayer is characterized by small strain variations and minimal charge fluctuations. Atomically resolved STM images on the hills of the nanostructures on the Ge(001) surface have confirmed the presence of a graphene monolayer. In addition, the STS/CITS maps show that high-quality graphene has been obtained on such terraces. The subsequent coalescence of graphene domains has led to a relatively well-oriented large-area layer. This is confirmed by LEED measurements, which have indicated that two orientations are preferable in the grown large-area graphene monolayer. The presence of large-area coverage by graphene has been also confirmed by low temperature Hall measurements of a macroscopic sample, showing an n-type concentration of 9.3 × 1012 cm-2 and a mobility of 2500 cm2 V-1 s-1. These important characteristic features of graphene indicate a high homogeneity of the layer grown on the large area Ge(001)/Si(001) substrates.

  8. Simple room-temperature preparation of high-yield large-area graphene oxide

    PubMed Central

    Huang, NM; Lim, HN; Chia, CH; Yarmo, MA; Muhamad, MR

    2011-01-01

    Graphene has attracted much attention from researchers due to its interesting mechanical, electrochemical, and electronic properties. It has many potential applications such as polymer filler, sensor, energy conversion, and energy storage devices. Graphene-based nanocomposites are under an intense spotlight amongst researchers. A large amount of graphene is required for preparation of such samples. Lately, graphene-based materials have been the target for fundamental life science investigations. Despite graphene being a much sought-after raw material, the drawbacks in the preparation of graphene are that it is a challenge amongst researchers to produce this material in a scalable quantity and that there is a concern about its safety. Thus, a simple and efficient method for the preparation of graphene oxide (GO) is greatly desired to address these problems. In this work, one-pot chemical oxidation of graphite was carried out at room temperature for the preparation of large-area GO with ~100% conversion. This high-conversion preparation of large-area GO was achieved using a simplified Hummer’s method from large graphite flakes (an average flake size of 500 μm). It was found that a high degree of oxidation of graphite could be realized by stirring graphite in a mixture of acids and potassium permanganate, resulting in GO with large lateral dimension and area, which could reach up to 120 μm and ~8000 μm2, respectively. The simplified Hummer’s method provides a facile approach for the preparation of large-area GO. PMID:22267928

  9. High throughput fabrication of large-area plasmonic color filters by soft-X-ray interference lithography.

    PubMed

    Sun, Libin; Hu, Xiaolin; Wu, Qingjun; Wang, Liansheng; Zhao, Jun; Yang, Shumin; Tai, Renzhong; Fecht, Hans-Jorg; Zhang, Dong-Xian; Wang, Li-Qiang; Jiang, Jian-Zhong

    2016-08-22

    Plasmonic color filters in mass production have been restricted from current fabrication technology, which impede their applications. Soft-X-ray interference lithography (XIL) has recently generated considerable interest as a newly developed technique for the production of periodic nano-structures with resolution theoretically below 4 nm. Here we ameliorate XIL by adding an order sorting aperture and designing the light path properly to achieve perfect-stitching nano-patterns and fast fabrication of large-area color filters. The fill factor of nanostructures prepared on ultrathin Ag films can largely affect the transmission minimum of plasmonic color filters. By changing the fill factor, the color can be controlled flexibly, improving the utilization efficiency of the mask in XIL simultaneously. The calculated data agree well with the experimental results. Finally, an underlying mechanism has been uncovered after systematically analyzing the localized surface plasmon polaritons (LSPPs) coupling in electric field distribution. PMID:27557190

  10. Abdominally implanted satellite transmitters affect reproduction and survival rather than migration of large shorebirds

    USGS Publications Warehouse

    Hooijmeijer, Jos C. E. W.; Gill, Robert E.; Mulcahy, Daniel M.; Tibbitts, T. Lee; Kentie, Rosemarie; Gerritsen, Gerrit J.; Bruinzeel, Leo W.; Tijssen, David C.; Harwood, Christopher M.; Piersma, Theunis

    2014-01-01

    Satellite telemetry has become a common technique to investigate avian life-histories, but whether such tagging will affect fitness is a critical unknown. In this study, we evaluate multi-year effects of implanted transmitters on migratory timing and reproductive performance in shorebirds. Shorebirds increasingly are recognized as good models in ecology and evolution. That many of them are of conservation concern adds to the research responsibilities. In May 2009, we captured 56 female Black-tailed Godwits Limosa limosa limosa during late incubation in The Netherlands. Of these, 15 birds were equipped with 26-g satellite transmitters with a percutaneous antenna (7.8 % ± 0.2 SD of body mass), surgically implanted in the coelom. We compared immediate nest survival, timing of migration, subsequent nest site fidelity and reproductive behaviour including egg laying with those of the remaining birds, a comparison group of 41 females. We found no effects on immediate nest survival. Fledging success and subsequent southward and northward migration patterns of the implanted birds conformed to the expectations, and arrival time on the breeding grounds in 2010–2012 did not differ from the comparison group. Compared with the comparison group, in the year after implantation, implanted birds were equally faithful to the nest site and showed equal territorial behaviour, but a paucity of behaviours indicating nests or clutches. In the 3 years after implantation, the yearly apparent survival of implanted birds was 16 % points lower. Despite intense searching, we found only three eggs of two implanted birds; all were deformed. A similarly deformed egg was reported in a similarly implanted Whimbrel Numenius phaeopus returning to breed in central Alaska. The presence in the body cavity of an object slightly smaller than a normal egg may thus lead to egg malformation and, likely, reduced egg viability. That the use of implanted satellite transmitters in these large shorebirds

  11. Factors affecting handling qualities of a lift-fan aircraft during steep terminal area approaches

    NASA Technical Reports Server (NTRS)

    Gerdes, R. M.; Hynes, C. S.

    1975-01-01

    The XV-5B lift-fan aircraft was used to explore the factors affecting handling qualities in the terminal area. A 10 deg ILS approach task was selected to explore these problems. Interception of the glide slope at 457.2 m, glide slope tracking, deceleration along the glide slope to a spot hover were considered. Variations in airplane deck angle, deceleration schedule, and powered-lift management were studied. The overall descent performance envelope was identified on the basis of fan stall, maximum comfortable descent rate, and controllability restrictions. The collective-lift stick provided precise glide slope tracking capability. The pilot preferred a deck-parallel attitude for which he used powered lift to control glide slope and pitch attitude to keep the angle of attack near zero. Workload was reduced when the deceleration schedule was delayed until the aircraft was well established on the glide slope, since thrust vector changes induced flight path disturbances.

  12. Evaluation of impact-affected areas of glass fibre thermoplastic composites from thermographic images

    NASA Astrophysics Data System (ADS)

    Boccardi, S.; Carlomagno, G. M.; Simeoli, G.; Russo, P.; Meola, C.

    2016-07-01

    The usefulness of an infrared imaging device, in terms of both acting as a mechanism for surface thermal monitoring when a specimen is being impacted and as a non-destructive evaluation technique, has already been proved. Nevertheless, past investigation has focused on mainly thermoset-matrix composites with little attention towards thermoplastic ones. Conversely, these thermoplastic composites are becoming ever more attractive to the aeronautical sector. Their main advantage lies in the possibility of modifying their interface strength by adjusting the composition of the matrix. However, for a proper exploitation of new materials it is necessary to detail their characterization. The purpose of the present paper is to focus on the use of infrared thermography (IRT) to gain information on the behaviour of thermoplastic composites under impact. In addition, attention is given to image processing algorithms with the aim of more effectively measuring the extension of the impact-affected area.4

  13. Rehabilitation planning for flood affected areas of Thailand: experience from Phipun District.

    PubMed

    Wickramanayake, E; Shook, G A; Rojnkureesatien, T

    1995-12-01

    Floods are common in Thailand. A flood in the southern part of the country in 1988 was of unprecedented magnitude. Several villages and vast tracts of agricultural land were covered with mud slides washed away from deforested hills. Rehabilitation of the affected areas, a task which required complex planning, was a challenge for the District Development Committee (DDC), which is the local level planning body. The Committee encountered several problems, including inability to use the existing data base and lack of accurate information, human resources, adequate funds and coordination among agencies. Unable to cope with the new challenges, the DDC resorted to conventional planning which failed to address the problems caused by the flood. Guidelines should be formulated to strengthen district level planning for rehabilitation after a disaster. PMID:8564458

  14. Hurricanes Katrina and Rita: evacuee healthcare efforts remote from hurricane affected areas.

    PubMed

    Rozeman, Phillip A; Mayeaux, Edward J

    2006-12-01

    Hurricanes Katrina and Rita produced the largest evacuation due to a natural disaster in United States history. Many people were evacuated or rescued from New Orleans and the Gulf Coast, resulting in a need for mass disaster shelters and medical care for months following the storms. The shelter healthcare system that was successfully developed in the Shreveport-Bossier City, Louisiana area was accomplished with little support from customary sources. This report is written after much discussion and introspection of community leaders involved "on the ground," who organized and provided medical services to evacuees of south Louisiana. Its purpose is to compile "lessons learned" in preparation for the next disaster recovery effort that might affect this or any other region of our country.

  15. Monitoring of mass measles campaign in AILA-affected areas of West Bengal.

    PubMed

    Dasgupta, Samir; Bagchi, Saumendra Nath; Ghosh, Pramit; Sardar, Jadab Chandra; Roy, Amal Sinha; Sau, Manabendra

    2010-01-01

    A mass measles campaign was organized in AILA-affected areas of West Bengal in July-August 2009. The present cross-sectional study was conducted with the objectives to monitor and assess the cold chain maintenance, safe injection practices, IEC methods adopted, and to observe the conduction of the sessions in the campaign. All the cold chain points at the block level had adequate vaccines and equipments, twice monitoring of temperature which was in optimal range. 82% sessions had team according to microplan, AWW was present and team members were actively mobilizing the children in 83% sessions, puncture proof container was used and vaccines were given in correct sites in more than 95% sessions. The study observed satisfactory conduction of the whole campaign, still the injection safety procedures should be strengthened considering the potential harm to the health care providers.

  16. Dust-storm dynamics over Sistan region, Iran: Seasonality, transport characteristics and affected areas

    NASA Astrophysics Data System (ADS)

    Rashki, A.; Kaskaoutis, D. G.; Francois, P.; Kosmopoulos, P. G.; Legrand, M.

    2015-03-01

    The present work examines the seasonality, dust-plume altitudinal variation and affected areas for dust storms originated from the Sistan region, southeastern Iran during the summer (June-September) months of the period 2001-2012 synthesizing local meteorological records, satellite observations (TOMS, OMI, METEOSAT, MODIS) and HYSPLIT forward trajectories. Dust-storm days (356 in total) are associated with visibility below 1 km at Zabol, Iran meteorological station with higher frequency and intensity in June and July. Monthly-mean composite maps of TOMS and OMI AI show high (>3-3.5) values over Sistan and nearby downwind areas. HYSPLIT forward-trajectory analysis at 500 m for air masses originated from Sistan on the dust-storm days shows that they usually follow an anti-clockwise transport direction at elevations usually below 2 km, initially moving southwards and then shifting to east-northeast when they are approaching the Arabian Sea coast. This is the result of the influence of the local topography and formation of thermal low-pressure systems over the arid lands. It is found that in few cases the dust storms from Sistan affect central/south Arabian Sea and India, while they control the aerosol loading over northernmost Arabian Sea. The Infrared Difference Dust Index (IDDI) images, which represent brightness temperature reduction due to dust presence over land, are used at specific periods of persistent dust storms over Sistan, confirming the main pathways of the dust plumes and illustrating the importance of the region as one of the most active dust sources in southwest Asia.

  17. Marine organic geochemistry in industrially affected coastal areas in Greece: Hydrocarbons in surface sediments

    NASA Astrophysics Data System (ADS)

    Hatzianestis, Ioannis

    2015-04-01

    Hydrocarbons are abundant components of the organic material in coastal zones. Their sources are mainly anthropogenic, but several natural ones have also been recognized. Among hydrocarbons, the polycyclic aromatic ones (PAHs) have received special attention since they considered as hazardous environmental chemicals and are included in priority pollutant lists. The purpose of this study was to investigate the distribution, sources and transport pathways of hydrocarbons in marine areas in Greece directly influenced from the operation of major industrial units in the coastal zone by using a molecular marker approach, characteristic compositional patterns and related indices and also to evaluate their potential toxicity. Thirty two surface sediment samples were collected from three marine areas: a) Antikyra bay in Korinthiakos gulf, affected from the operation of an alumina and production plant b) Larymna bay in Noth Evoikos, affected from the operation of a nickel production plant and c) Aliveri bay in South Evoikos Gulf, affected from a cement production plant. In all the studied areas aquaculture and fishing activities have been also developed in the coastal zone. High aliphatic hydrocarbon (AHC) concentrations (~500 μg/g), indicating significant petroleum related inputs, were measured only in Antikyra bay. In all the other samples, AHC values were below 100 μg/g. N-alkanes were the most prominent resolved components (R) with an elevated odd to even carbon number preference, revealing the high importance of terrestrial inputs in the study areas. The unresolved complex mixture (UCM) was the major component of the aliphatic fraction (UCM/R > 4), indicating a chronic oil pollution. A series of hopanes were also identified, with patterns characteristic of oil-derived hydrocarbons, further confirming the presence of pollutant inputs from fossil fuel products. Extremely high PAH concentrations (> 100,000 ng/g) were found in the close vicinity of the alumina production

  18. Design, Production and Testing of Cost-Effective, Large-Area, MCP-based Planar Photodetectors

    NASA Astrophysics Data System (ADS)

    Xie, Junqi; Byrum, Karen; Demarteau, Marcel; Noonan, John; Setru, Sagar; Virgo, Mathew; Wagner, Robert; Walters, Dean; Wang, Xing; Xia, Lei; Zhao, Huyue

    2014-03-01

    Microchannel plate (MCP)-based photodetectors with large-area, thin planar geometry and glass-body assembly, are considered as next generation photodetector to replace photomultiplier tubes. They have shown significant potential for applications in high energy collider physics and astrophysics. Due to the extreme sensitivity of the photocathode to water and oxygen, the production of this kind of photodetectors requires photocathodes to be transferred under high vacuum. A new photodetector production facility at Argonne National Laboratory was designed and constructed. The facility aims to produce small form-factor, MCP-based photodetectors completely made out of glass. 6 x 6 cm2 photodetectors using metal and alkali antimonide as photocathode are currently under production. An overview of the production sequence and first performance results will be presented. Scaling up the production to larger form-factor devices will be discussed. The challenge of sealing a large area photodetector has recently been overcome. Windows with 20 × 20 cm2 active photocathode area were successfully sealed and progress towards large-area photodetector production progress will be reported.

  19. Large Area Superconducting TES Spiderweb Bolometer for Multi-mode Cavity Microwave Detect

    NASA Astrophysics Data System (ADS)

    Biasotti, M.; Bagliani, D.; Corsini, D.; De Bernardis, P.; Gatti, F.; Gualtieri, R.; Lamagna, L.; Masi, S.; Pizzigoni, G.; Schillaci, A.

    2014-05-01

    For the cosmic microwave background, the increase of the sensitivity of present superconducting TES Spiderweb Bolometers can be done coupling them to a large set of modes of the EM radiation inside the cavity. This will require a proper shaping of the horn-cavity assembly for the focal plane of the microwave telescope and the use of large area bolometers. Large area spiderweb bolometers of 8 mm diameter and a mesh size of 250 μm are fabricated in order to couple with approximately the first 20 modes of the cavity at about 140 GHz. These bolometers are fabricated with micro machining techniques from silicon wafer covered with SiO2 - Si3N4 CVD thick films, 0.3 μm and 1 μm respectively. The sensor is a Ti/Au/Ti 3 layer TES sensor with Tc tuned in the 330-380 mK and 2 mK transition width. The TES is electronically coupled to the EM gold absorber that is grown on to the spiderweb mesh in order to sense the temperature of the electron gas heated by the EM radiation. The gold absorber mesh has 5 um beam size over a Si3N4 10 μm beam size supporting mesh. The Si3N4 mesh is then fully suspended by means of DRIE back etching of the Si substrate. Here we present the first results of these large area bolometers.

  20. A novel lithography technique for formation of large areas of uniform nanostructures

    NASA Astrophysics Data System (ADS)

    Wu, Wei; Dey, Dibyendu; Memis, Omer G.; Katsnelson, Alex; Mohseni, Hooman

    2008-08-01

    With nanotechnology becoming widely used, many applications such as plasmonics, sensors, storage devices, solar cells, nano-filtration and artificial kidneys require the structures with large areas of uniform periodic nanopatterns. Most of the current nano-manufacturing techniques, including photolithography, electron-beam lithography, and focal ion beam milling, are either slow or expensive to be applied into the areas. Here, we demonstrate an alternative and novel lithography technique - Nanosphere Photolithography (NSP) - that generates a large area of highly uniform periodic nanoholes or nanoposts by utilizing the monolayer of hexagonally close packed (HCP) silica microspheres as super-lenses on top of photoresist. The size of the nanopatterns generated is almost independent of the sphere sizes and hence extremely uniform patterns can be obtained. We demonstrate that the method can produce hexagonally packed arrays of hole of sub-250 nm size in positive photoresist using a conventional exposure system with a broadband UV source centered at 400 nm. We also show a large area of highly uniform gold nanoholes (~180 nm) and nanoposts (~300nm) array with the period of 1 μm fabricated by the combination of lift-off and NSP. The process is not limited to gold. Similar structures have been shown with aluminum and silicon dioxide layer. The period and size of the structures can also be tuned by changing proper parameters. The technique applying self-assembled and focusing properties of micro-/nano-spheres into photolithography establishes a new paradigm for mask-less photolithography technique, allowing rapid and economical creation of large areas of periodic nanostructures with a high throughput.

  1. A Distributed Water Circulation Model Incorporating Large Irrigation Schemes for Paddy Areas

    NASA Astrophysics Data System (ADS)

    Yoshida, T.; Masumoto, T.; Kudo, R.; Horikawa, N.

    2010-12-01

    Water intake for paddy irrigation in Japan accounts for approximately 70% of total intake. Spatial and temporal variation of precipitation and river flow changes, likely to be caused by climate changes, directly affect paddy irrigation and its management schemes. Previous studies show that potential water stresses were estimated in the framework of grid-based distributed water circulation models, in which water availability and demand were roughly compared in large-scale grids of 10~100km. However, in mid and small-scale basins, where we carry out impact assessment studies of 1~10km grids, we need schemes to couple the irrigation intake and its allocation, because agricultural water is highly dependent on human decision making processes. Then, we have developed a model that couples natural hydrological behaviors of a basin and artificial irrigation systems. A distributed water circulation model, which explains natural hydrological behaviors of a basin, consists of approximately 1km square gridded meshes. Infiltration and saturation-excess flow and water requirements of irrigated paddy fields on any grid are calculated. The generated surface flow is routed by a kinematic wave equation so that daily flow rate can be calculated at any point of interest. The core of the model is water allocation and management scheme that exploit the spatial database of irrigation facilities and beneficiary areas. This analysis consists of new modeled plane for irrigation, which is calculated independently from the surface plain of the distributed water circulation model. Following the configuration of the water allocation and management schemes, the model is coupled with the distributed water circulation model. The reservoir operation scheme is an algorithm to determine the reservoir releases for irrigation based on requirement and flow rate at downstream diversion weirs. Diversion weirs intake water from associated rivers at the maximum rate, if water is available. The integrated

  2. Nitrogen multitemporal monitoring through mosses in urban areas affected by mud volcanoes around Mt. Etna, Italy.

    PubMed

    Bonanno, Giuseppe

    2013-10-01

    Nitrogen emissions were assessed by using mosses as bioindicators in a densely inhabited area affected by mud volcanoes. Such volcanoes, locally called Salinelle, are phenomena that occur around Mt. Etna (Sicily, Italy), and are interpreted as the surface outflow of a hydrothermal system located below Mt. Etna, which releases sedimentary fluids (hydrocarbons and Na-Cl brines) along with magmatic gases (mainly CO2 and He). To date, N emissions from such mud volcanoes have been only quantitatively assessed, and no biomonitoring campaigns are reported about the cumulative effects of these emissions. This study analyzed N concentrations in moss, water and soil samples, collected in a 4-year monitoring campaign. The bryophyte Bryum argenteum, a species widely adopted in surveys of atmospheric pollution, was used as a biological indicator. N concentrations in biomonitors showed relatively low values in the study sites. However, the results of this study suggest that N emissions from Salinelle may have an impact on surrounding ecosystems because N values in moss and water showed a significant correlation. N oxides, in particular, contribute to acidification of ecosystems, thus multitemporal biomonitoring is recommended, especially in those areas where N emitting sources are anthropogenic and natural.

  3. Female reproductive function in areas affected by radiation after the Chernobyl power station accident

    SciTech Connect

    Kulakov, V.I.; Sokur, T.N.; Volobuev, A.I.

    1993-07-01

    This paper reports the results of a comprehensive survey of the effects of the accidental release of radiation caused by the accident at the Chernobyl nuclear power station in April 1986. The accident and the resulting release of radiation and radioactive products into the atmosphere produced the most serious environmental contamination so far recorded. We have concentrated on evaluating the outcomes and health risks to women, their reproductive situation, and consequences for their progeny. We have concentrated on two well-defined areas: the Chechersky district of the Gomel region in Belorussia and the Polessky district of the Kiev region in the Ukraine. A number of investigations were carried out on 688 pregnant women and their babies, and data were obtained from 7000 labor histories of the development of newborns for a period of 8 years (3 years before the accident and 5 years after it). Parameters examined included birth rate, thyroid pathology, extragenital pathology such as anemias, renal disorders, hypertension, and abnormalities in the metabolism of fats, complications of gestation, spontaneous abortions, premature deliveries, perinatal morbidity and mortality, stillbirths and early neonatal mortality, infections and inflammatory diseases, neurological symptoms and hemic disturbances in both mothers and infants, trophic anomalies, and biochemical and structural changes in the placenta. Several exogenous, complicating influences were also considered such as psycho-emotional factors, stress, lifestyle changes, and others caused directly by the hazardous situation and by its consequences such as treatment, removal from affected areas, etc. 9 figs.

  4. Impact of large industrial emission sources on mortality and morbidity in Chile: A small-areas study.

    PubMed

    Ruiz-Rudolph, Pablo; Arias, Nelson; Pardo, Sandra; Meyer, Marianne; Mesías, Stephanie; Galleguillos, Claudio; Schiattino, Irene; Gutiérrez, Luis

    2016-01-01

    Chile suffers significant pollution from large industrial emitters associated with the mining, metal processing, paper production, and energy industries. The aim of this research was to determine whether the presence of large industrial facilities (i.e. coal- and oil-fired power plants, pulp and paper mills, mining facilities, and smelters) affects mortality and morbidity rates in Chile. For this, we conducted an ecological study that used Chilean communes as small-area observation units to assess mortality and morbidity. Public databases provided information on large pollution sources relevant to Chile. The large sources studied were oil- and coal-fired power plants, copper smelters, pulp and paper mills, and large mining facilities. Large sources were filtered by first year of production, type of process, and size. Mortality and morbidity data were acquired from public national databases, with morbidity being estimated from hospitalization records. Cause-specific rates were calculated for the main outcomes: cardiovascular, respiratory, cancer; and other more specific health outcomes. The impact of the large pollution sources was estimated using Bayesian models that included spatial correlation, overdispersion, and other covariates. Large and significant increases in health risks (around 20%-100%) were found for communes with power plants and smelters for total, cardiovascular, respiratory, all-cancer, and lung cancer mortality. Higher hospitalization rates for cardiovascular disease, respiratory disease, cancer, and pneumonia (20-100%) were also found for communes with power plants and smelters. The impacts were larger for men than women in terms of both mortality and hospitalizations. The impacts were also larger when the sources were analyzed as continuous (production volume) rather than dichotomous (presence/absence) variables. In conclusion, significantly higher rates of total cardiovascular, respiratory, all-cancer and lung cancer mortality and

  5. Impact of large industrial emission sources on mortality and morbidity in Chile: A small-areas study.

    PubMed

    Ruiz-Rudolph, Pablo; Arias, Nelson; Pardo, Sandra; Meyer, Marianne; Mesías, Stephanie; Galleguillos, Claudio; Schiattino, Irene; Gutiérrez, Luis

    2016-01-01

    Chile suffers significant pollution from large industrial emitters associated with the mining, metal processing, paper production, and energy industries. The aim of this research was to determine whether the presence of large industrial facilities (i.e. coal- and oil-fired power plants, pulp and paper mills, mining facilities, and smelters) affects mortality and morbidity rates in Chile. For this, we conducted an ecological study that used Chilean communes as small-area observation units to assess mortality and morbidity. Public databases provided information on large pollution sources relevant to Chile. The large sources studied were oil- and coal-fired power plants, copper smelters, pulp and paper mills, and large mining facilities. Large sources were filtered by first year of production, type of process, and size. Mortality and morbidity data were acquired from public national databases, with morbidity being estimated from hospitalization records. Cause-specific rates were calculated for the main outcomes: cardiovascular, respiratory, cancer; and other more specific health outcomes. The impact of the large pollution sources was estimated using Bayesian models that included spatial correlation, overdispersion, and other covariates. Large and significant increases in health risks (around 20%-100%) were found for communes with power plants and smelters for total, cardiovascular, respiratory, all-cancer, and lung cancer mortality. Higher hospitalization rates for cardiovascular disease, respiratory disease, cancer, and pneumonia (20-100%) were also found for communes with power plants and smelters. The impacts were larger for men than women in terms of both mortality and hospitalizations. The impacts were also larger when the sources were analyzed as continuous (production volume) rather than dichotomous (presence/absence) variables. In conclusion, significantly higher rates of total cardiovascular, respiratory, all-cancer and lung cancer mortality and

  6. Evaluation of large area crop estimation techniques using LANDSAT and ground-derived data. [Missouri

    NASA Technical Reports Server (NTRS)

    Amis, M. L.; Lennington, R. K.; Martin, M. V.; Mcguire, W. G.; Shen, S. S. (Principal Investigator)

    1981-01-01

    The results of the Domestic Crops and Land Cover Classification and Clustering study on large area crop estimation using LANDSAT and ground truth data are reported. The current crop area estimation approach of the Economics and Statistics Service of the U.S. Department of Agriculture was evaluated in terms of the factors that are likely to influence the bias and variance of the estimator. Also, alternative procedures involving replacements for the clustering algorithm, the classifier, or the regression model used in the original U.S. Department of Agriculture procedures were investigated.

  7. Coatings for large-area low-cost solar concentrators and reflectors

    NASA Astrophysics Data System (ADS)

    Martin, Peter M.; Affinito, John D.; Gross, Mark E.; Bennett, Wendy D.

    1994-09-01

    Large-optics coating facilities and processes at Pacific Northwest Laboratory (PNL) that were used to develop large-area high-performance laser mirrors for SDIO are now being used to fabricate a variety of optical components for commercial clients, and for novel applications for other DoD clients. Emphasis of this work is on technology transfer of low-cost coating processes and equipment to private clients. Much of the technology transfer is being accomplished through the CRADA (Cooperative Research and Development Agreement) process funded by the Department of Energy (DOE).

  8. Large-Area Atom Interferometry with Frequency-Swept Raman Adiabatic Passage.

    PubMed

    Kotru, Krish; Butts, David L; Kinast, Joseph M; Stoner, Richard E

    2015-09-01

    We demonstrate light-pulse atom interferometry with large-momentum-transfer atom optics based on stimulated Raman transitions and frequency-swept adiabatic rapid passage. Our atom optics have produced momentum splittings of up to 30 photon recoil momenta in an acceleration-sensitive interferometer for laser cooled atoms. We experimentally verify the enhancement of phase shift per unit acceleration and characterize interferometer contrast loss. By forgoing evaporative cooling and velocity selection, this method lowers the atom shot-noise-limited measurement uncertainty and enables large-area atom interferometry at higher data rates.

  9. Performance of the Anti-Coincidence Detector on the GLAST Large Area Telescope

    SciTech Connect

    Thompson, D.J.; Charles, E.; Hartman, R.C.; Moiseev, A.A.; Ormes, J.F.; /NASA, Goddard /Denver U.

    2007-10-22

    The Anti-Coincidence Detector (ACD), the outermost detector layer in the Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT), is designed to detect and veto incident cosmic ray charged particles, which outnumber cosmic gamma rays by 3-4 orders of magnitude. The challenge in ACD design is that it must have high (0.9997) detection efficiency for singly-charged relativistic particles, but must also have a low probability for self-veto of high-energy gammas by backsplash radiation from interactions in the LAT calorimeter. Simulations and tests demonstrate that the ACD meets its design requirements. The performance of the ACD has remained stable through stand-alone environmental testing, shipment across the U.S., installation onto the LAT, shipment back across the U.S., LAT environmental testing, and shipment to Arizona. As part of the fully-assembled GLAST observatory, the ACD is being readied for final testing before launch.

  10. Field effect tuning of microwave Faraday rotation and isolation with large-area graphene

    NASA Astrophysics Data System (ADS)

    Skulason, Helgi S.; Sounas, Dimitrios L.; Mahvash, Farzaneh; Francoeur, Sebastien; Siaj, Mohamed; Caloz, Christophe; Szkopek, Thomas

    2015-08-01

    We have demonstrated field effect tuning of microwave frequency Faraday rotation in magnetically biased large-area graphene in a hollow circular waveguide isolator geometry. Oxidized intrinsic silicon was used as a microwave transparent back-gate for large-area graphene devices. A 26 dB modulation of isolation in the K-band was achieved with a gate voltage modulation of 10 V corresponding to a carrier density modulation of 7 × 10 11 /cm2. We have developed a simple analytical model for transmission and isolation of the structure. Field effect modulation of Faraday rotation can be extended to other two dimensional electronic systems and is anticipated to be useful for gate voltage controlled isolators, circulators, and other non-reciprocal devices.

  11. A green synthesis method for large area silver thin film containing nanoparticles.

    PubMed

    Shinde, N M; Lokhande, A C; Lokhande, C D

    2014-07-01

    The green synthesis method is inexpensive and convenient for large area deposition of thin films. For the first time, a green synthesis method for large area silver thin film containing nanoparticles is reported. Silver nanostructured films are deposited using silver nitrate solution and guava leaves extract. The study confirmed that the reaction time plays a key role in the growth and shape/size control of silver nanoparticles. The properties of silver films are studied using UV-visible spectrophotometer, scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), contact angle, Fourier-transform Raman (FT-Raman) spectroscopy and Photoluminescence (PL) techniques. Finally, as an application, these films are used effectively in antibacterial activity study. PMID:24836517

  12. Large area mapping of soil moisture using the ESTAR passive microwave radiometer

    NASA Technical Reports Server (NTRS)

    Jackson, T. J.; Levine, D. M.; Swift, C. T.; Schmugge, T. J.

    1994-01-01

    Investigations designed to study land surface hydrologic-atmospheric interactions, showing the potential of L band passive microwave radiometry for measuring surface soil moisture over large areas, are discussed. Satisfying the data needs of these investigations requires the ability to map large areas rapidly. With aircraft systems this means a need for more beam positions over a wider swath on each flightline. For satellite systems the essential problem is resolution. Both of these needs are currently being addressed through the development and verification of Electronically Scanned Thinned Array Radiometer (ESTAR) technology. The ESTAR L band radiometer was evaluated for soil moisture mapping applications in two studies. The first was conducted over the semiarid rangeland Walnut Gulch watershed located in south eastern Arizona (U.S.). The second was performed in the subhumid Little Washita watershed in south west Oklahoma (U.S.). Both tests showed that the ESTAR is capable of providing soil moisture with the same level of accuracy as existing systems.

  13. Large area silicon sheet by EFG. Annual progress report, October 1, 1978-September 30, 1979

    SciTech Connect

    Not Available

    1980-03-14

    The progress which has been made in 1978/1979 to evolve systems designs for growth stations which produce multiple silicon ribbons by the EFG process is reported. This progress culminated in the demonstration of five ribbon multiple growth in May 1979 and in recent advances toward improved electronic quality of ribbons grown from these machines. These advances were made in large measure by studies in which the composition of the gas environment around the meniscus area was varied. By introducing gases such as CO/sub 2/, CO, and CH/sub 4/ into this region, reproducible increases in diffusion length and cell performance have been realized, with the best large area (5 cm x 10 cm) cells exceeding 11% (AM1) efficiency.

  14. Electronic sensor and actuator webs for large-area complex geometry cardiac mapping and therapy

    PubMed Central

    Kim, Dae-Hyeong; Ghaffari, Roozbeh; Lu, Nanshu; Wang, Shuodao; Lee, Stephen P.; Keum, Hohyun; D’Angelo, Robert; Klinker, Lauren; Su, Yewang; Lu, Chaofeng; Kim, Yun-Soung; Ameen, Abid; Li, Yuhang; Zhang, Yihui; de Graff, Bassel; Hsu, Yung-Yu; Liu, ZhuangJian; Ruskin, Jeremy; Xu, Lizhi; Lu, Chi; Omenetto, Fiorenzo G.; Huang, Yonggang; Mansour, Moussa; Slepian, Marvin J.; Rogers, John A.

    2012-01-01

    Curved surfaces, complex geometries, and time-dynamic deformations of the heart create challenges in establishing intimate, nonconstraining interfaces between cardiac structures and medical devices or surgical tools, particularly over large areas. We constructed large area designs for diagnostic and therapeutic stretchable sensor and actuator webs that conformally wrap the epicardium, establishing robust contact without sutures, mechanical fixtures, tapes, or surgical adhesives. These multifunctional web devices exploit open, mesh layouts and mount on thin, bio-resorbable sheets of silk to facilitate handling in a way that yields, after dissolution, exceptionally low mechanical moduli and thicknesses. In vivo studies in rabbit and pig animal models demonstrate the effectiveness of these device webs for measuring and spatially mapping temperature, electrophysiological signals, strain, and physical contact in sheet and balloon-based systems that also have the potential to deliver energy to perform localized tissue ablation. PMID:23150574

  15. Extraordinary suppression of carrier scattering in large area graphene oxide films

    SciTech Connect

    Negishi, R. Kobayashi, Y.

    2014-12-22

    In this study, we find that thermal treatment in ethanol vapor has a remarkable suppression effect of carrier scattering occurring between reduced graphene oxide (rGO) flakes in large area films. We observe excellent electrical properties such as high carrier mobility (∼5 cm{sup 2}/Vs) and low sheet resistance (∼40 KΩ/□) for the rGO films. From the electrical conductivity analysis of large area rGO films using two-dimensional variable range hopping model and structural analysis using Raman spectra measured from the rGO films, we reveal that the significant effect is caused by the expansion of conjugated π-electron system in rGO flake due to the efficient restoration of graphitic structure.

  16. Circular polarization dependent cyclotron resonance in large-area graphene in ultrahigh magnetic fields

    NASA Astrophysics Data System (ADS)

    Booshehri, L. G.; Mielke, C. H.; Rickel, D. G.; Crooker, S. A.; Zhang, Q.; Ren, L.; Hároz, E. H.; Rustagi, A.; Stanton, C. J.; Jin, Z.; Sun, Z.; Yan, Z.; Tour, J. M.; Kono, J.

    2012-05-01

    Using ultrahigh magnetic fields up to 170 T and polarized midinfrared radiation with tunable wavelengths from 9.22 to 10.67 μm, we studied cyclotron resonance in large-area graphene grown by chemical vapor deposition. Circular polarization dependent studies reveal strong p-type doping for as-grown graphene, and the dependence of the cyclotron resonance on radiation wavelength allows for a determination of the Fermi energy. Thermal annealing shifts the Fermi energy to near the Dirac point, resulting in the simultaneous appearance of hole and electron cyclotron resonance in the magnetic quantum limit, even though the sample is still p-type, due to graphene's linear dispersion and unique Landau level structure. These high-field studies therefore allow for a clear identification of cyclotron resonance features in large-area, low-mobility graphene samples.

  17. Electronic sensor and actuator webs for large-area complex geometry cardiac mapping and therapy.

    PubMed

    Kim, Dae-Hyeong; Ghaffari, Roozbeh; Lu, Nanshu; Wang, Shuodao; Lee, Stephen P; Keum, Hohyun; D'Angelo, Robert; Klinker, Lauren; Su, Yewang; Lu, Chaofeng; Kim, Yun-Soung; Ameen, Abid; Li, Yuhang; Zhang, Yihui; de Graff, Bassel; Hsu, Yung-Yu; Liu, Zhuangjian; Ruskin, Jeremy; Xu, Lizhi; Lu, Chi; Omenetto, Fiorenzo G; Huang, Yonggang; Mansour, Moussa; Slepian, Marvin J; Rogers, John A

    2012-12-01

    Curved surfaces, complex geometries, and time-dynamic deformations of the heart create challenges in establishing intimate, nonconstraining interfaces between cardiac structures and medical devices or surgical tools, particularly over large areas. We constructed large area designs for diagnostic and therapeutic stretchable sensor and actuator webs that conformally wrap the epicardium, establishing robust contact without sutures, mechanical fixtures, tapes, or surgical adhesives. These multifunctional web devices exploit open, mesh layouts and mount on thin, bio-resorbable sheets of silk to facilitate handling in a way that yields, after dissolution, exceptionally low mechanical moduli and thicknesses. In vivo studies in rabbit and pig animal models demonstrate the effectiveness of these device webs for measuring and spatially mapping temperature, electrophysiological signals, strain, and physical contact in sheet and balloon-based systems that also have the potential to deliver energy to perform localized tissue ablation. PMID:23150574

  18. Phase stabilization of a large-mode-area ytterbium-doped fiber amplifier.

    PubMed

    Jones, D C; Stacey, C D; Scott, A M

    2007-03-01

    Measurements are reported on the open and closed-loop phase stability of a large-mode-area ytterbium-doped fiber amplifier. Phase fluctuations are characterized by a high-frequency low-amplitude jitter superimposed on a slow power-dependent drift. The amplifier may be phase locked to a precision of lambda/20 by using a low-bandwidth feedback loop. PMID:17392889

  19. Lithography-free large-area metamaterials for stable thermophotovoltaic energy conversion

    DOE PAGES

    Coppens, Zachary J.; Kravchenko, Ivan I.; Valentine, Jason G.

    2016-02-08

    A large-area metamaterial thermal emitter is fabricated using facile, lithography-free techniques. The device is composed of conductive oxides, refractory ceramics, and noble metals and shows stable, selective emission after exposure to 1173 K for 22 h in oxidizing and inert atmospheres. Lastly, the results indicate that the metamaterial can be used to achieve high-performance thermophotovoltaic devices for applications such as portable power generation.

  20. Fabrication of large-area and low mass critical-angle x-ray transmission gratings

    NASA Astrophysics Data System (ADS)

    Heilmann, Ralf K.; Bruccoleri, Alex R.; Guan, Dong; Schattenburg, Mark L.

    2014-07-01

    Soft x-ray spectroscopy of celestial sources with high resolving power R = E/ΔE and large collecting area addresses important science listed in the Astro2010 Decadal Survey New Worlds New Horizons, such as the growth of the large scale structure of the universe and its interaction with active galactic nuclei, the kinematics of galactic outflows, as well as coronal emission from stars and other topics. Numerous studies have shown that a transmission grating spectrometer based on lightweight critical-angle transmission (CAT) gratings can deliver R = 3000-5000 and large collecting area with high efficiency and minimal resource requirements, providing spectroscopic figures of merit at least an order of magnitude better than grating spectrometers on Chandra and XMM-Newton, as well as future calorimeter-based missions. The recently developed CAT gratings combine the advantages of transmission gratings (low mass, relaxed figure and alignment tolerances) and blazed reflection gratings (high broad band diffraction efficiency, utilization of higher diffraction orders). Their working principle based on blazing through reflection off the smooth, ultra-high aspect ratio grating bar sidewalls has previously been demonstrated on small samples with x rays. For larger gratings (area greater than 1 inch square) we developed a fabrication process for grating membranes with a hierarchy of integrated low-obscuration supports. The fabrication involves a combination of advanced lithography and highly anisotropic dry and wet etching techniques. We report on the latest fabrication results of free-standing, large-area CAT gratings with polished sidewalls and preliminary x-ray tests.

  1. Hot-electron flux observation in large-area microwave sustained plasmas

    NASA Astrophysics Data System (ADS)

    Kudela, Jozef; Terebessy, Tibor; Kando, Masashi

    2000-03-01

    Flux of hot electrons directed away from the waveguiding plasma-dielectric interface was experimentally observed in large-area microwave discharges. The energy of these electrons attains values of some 60 eV, and they are believed to be originating from the resonantly-enhanced electric field region localized near the dielectric. The phenomenon appears to play a significant role in discharge heating mechanism, which is demonstrated by plasma parameter profiles.

  2. Fabrication of CdZnTe strip detectors for large area arrays

    SciTech Connect

    Stahle, C.M.; Shi, Z.Q.; Hu, K.

    1998-12-31

    A CdZnTe strip detector large area array ({approximately} 60 cm{sup 2} with 36 detectors) with capabilities for high resolution imaging and spectroscopy has been built as a prototype for a space flight gamma ray burst instrument. The detector array also has applications in nuclear medical imaging. Two dimensional orthogonal strip detectors with 100 {micro}m pitch have been fabricated and tested. Details for the array design, fabrication and evaluation of the detectors will be presented.

  3. Caustic Recycle from Hanford Tank Waste Using Large Area NaSICON Structures (LANS)

    SciTech Connect

    Fountain, Matthew S.; Sevigny, Gary J.; Balagopal, S.; Bhavaraju, S.

    2009-03-31

    This report presents the results of a 5-day test of an electrochemical bench-scale apparatus using a proprietary (NAS-GY) material formulation of a (Na) Super Ion Conductor (NaSICON) membrane in a Large Area NaSICON Structures (LANS) configuration. The primary objectives of this work were to assess system performance, membrane seal integrity, and material degradation while removing Na from Group 5 and 6 tank waste from the Hanford Site.

  4. Implications of Harvest on the Boundaries of Protected Areas for Large Carnivore Viewing Opportunities.

    PubMed

    Borg, Bridget L; Arthur, Stephen M; Bromen, Nicholas A; Cassidy, Kira A; McIntyre, Rick; Smith, Douglas W; Prugh, Laura R

    2016-01-01

    The desire to see free ranging large carnivores in their natural habitat is a driver of tourism in protected areas around the globe. However, large carnivores are wide-ranging and subject to human-caused mortality outside protected area boundaries. The impact of harvest (trapping or hunting) on wildlife viewing opportunities has been the subject of intense debate and speculation, but quantitative analyses have been lacking. We examined the effect of legal harvest of wolves (Canis lupus) along the boundaries of two North American National Parks, Denali (DNPP) and Yellowstone (YNP), on wolf viewing opportunities within the parks during peak tourist season. We used data on wolf sightings, pack sizes, den site locations, and harvest adjacent to DNPP from 1997-2013 and YNP from 2008-2013 to evaluate the relationship between harvest and wolf viewing opportunities. Although sightings were largely driven by wolf population size and proximity of den sites to roads, sightings in both parks were significantly reduced by harvest. Sightings in YNP increased by 45% following years with no harvest of a wolf from a pack, and sightings in DNPP were more than twice as likely during a period with a harvest buffer zone than in years without the buffer. These findings show that harvest of wolves adjacent to protected areas can reduce sightings within those areas despite minimal impacts on the size of protected wolf populations. Consumptive use of carnivores adjacent to protected areas may therefore reduce their potential for non-consumptive use, and these tradeoffs should be considered when developing regional wildlife management policies.

  5. Implications of Harvest on the Boundaries of Protected Areas for Large Carnivore Viewing Opportunities

    PubMed Central

    Borg, Bridget L.; Arthur, Stephen M.; Bromen, Nicholas A.; Cassidy, Kira A.; McIntyre, Rick; Smith, Douglas W.; Prugh, Laura R.

    2016-01-01

    The desire to see free ranging large carnivores in their natural habitat is a driver of tourism in protected areas around the globe. However, large carnivores are wide-ranging and subject to human-caused mortality outside protected area boundaries. The impact of harvest (trapping or hunting) on wildlife viewing opportunities has been the subject of intense debate and speculation, but quantitative analyses have been lacking. We examined the effect of legal harvest of wolves (Canis lupus) along the boundaries of two North American National Parks, Denali (DNPP) and Yellowstone (YNP), on wolf viewing opportunities within the parks during peak tourist season. We used data on wolf sightings, pack sizes, den site locations, and harvest adjacent to DNPP from 1997–2013 and YNP from 2008–2013 to evaluate the relationship between harvest and wolf viewing opportunities. Although sightings were largely driven by wolf population size and proximity of den sites to roads, sightings in both parks were significantly reduced by harvest. Sightings in YNP increased by 45% following years with no harvest of a wolf from a pack, and sightings in DNPP were more than twice as likely during a period with a harvest buffer zone than in years without the buffer. These findings show that harvest of wolves adjacent to protected areas can reduce sightings within those areas despite minimal impacts on the size of protected wolf populations. Consumptive use of carnivores adjacent to protected areas may therefore reduce their potential for non-consumptive use, and these tradeoffs should be considered when developing regional wildlife management policies. PMID:27124729

  6. Implications of Harvest on the Boundaries of Protected Areas for Large Carnivore Viewing Opportunities.

    PubMed

    Borg, Bridget L; Arthur, Stephen M; Bromen, Nicholas A; Cassidy, Kira A; McIntyre, Rick; Smith, Douglas W; Prugh, Laura R

    2016-01-01

    The desire to see free ranging large carnivores in their natural habitat is a driver of tourism in protected areas around the globe. However, large carnivores are wide-ranging and subject to human-caused mortality outside protected area boundaries. The impact of harvest (trapping or hunting) on wildlife viewing opportunities has been the subject of intense debate and speculation, but quantitative analyses have been lacking. We examined the effect of legal harvest of wolves (Canis lupus) along the boundaries of two North American National Parks, Denali (DNPP) and Yellowstone (YNP), on wolf viewing opportunities within the parks during peak tourist season. We used data on wolf sightings, pack sizes, den site locations, and harvest adjacent to DNPP from 1997-2013 and YNP from 2008-2013 to evaluate the relationship between harvest and wolf viewing opportunities. Although sightings were largely driven by wolf population size and proximity of den sites to roads, sightings in both parks were significantly reduced by harvest. Sightings in YNP increased by 45% following years with no harvest of a wolf from a pack, and sightings in DNPP were more than twice as likely during a period with a harvest buffer zone than in years without the buffer. These findings show that harvest of wolves adjacent to protected areas can reduce sightings within those areas despite minimal impacts on the size of protected wolf populations. Consumptive use of carnivores adjacent to protected areas may therefore reduce their potential for non-consumptive use, and these tradeoffs should be considered when developing regional wildlife management policies. PMID:27124729

  7. Combining nanoimprint lithography with dynamic templating for the fabrication of dense, large-area nanoparticle arrays

    NASA Astrophysics Data System (ADS)

    Golze, Spencer D.

    The study of nanomaterials is a developing science with potentially large benefits in the development of catalysts, optical and chemical sensors, and solid state memory devices. As several of these devices require large arrays of nanoparticles, one of the greatest obstacles in material characterization and device development is the reliable manufacture of nanopatterns over a large surface area. In addition, various applications require different nanoparticle size and density. High density arrays with small nanoparticle sizes are difficult to achieve over a large surface area using current manufacturing processes. Herein, Nanoimprint Lithography (NIL) and Dynamic Templating are combined to create a new manufacturing process capable of developing high density arrays with small nanoparticle sizes. The NIL process involves the stamping of a polymer coated substrate by a silicon stamp with patterned nanofeatures. The stamp is then removed, leaving the pattern in the polymer, which is first etched and then coated with a thin layer of metal, filling the recessed regions of the pattern. The excess polymer is dissolved, leaving a pattern of nanoparticles on the substrate matching the pattern on the stamp. When Dynamic Templating is applied, a very thin layer of metal can be coated, which forms small nanoparticle sizes when dewetted. A custom NIL system has been developed to combine these two processes together, which has now proven to yield consistent large-area, dense arrays with a small nanoparticle size. An array spacing of 700 nm has been achieved, along with a nanoparticle size of 90 nm. Arrays have been created in gold and palladium, where there is now the potential to combine them with other solution-based syntheses which should lead to complex nanoparticle geometries suitable for sensor applications.

  8. Self-assembly and nanosphere lithography for large-area plasmonic patterns on graphene.

    PubMed

    Lotito, Valeria; Zambelli, Tomaso

    2015-06-01

    Plasmonic structures on graphene can tailor its optical properties, which is essential for sensing and optoelectronic applications, e.g. for the enhancement of photoresponsivity of graphene photodetectors. Control over their structural and, hence, spectral properties can be attained by using electron beam lithography, which is not a viable solution for the definition of patterns over large areas. For the fabrication of large-area plasmonic nanostructures, we propose to use self-assembled monolayers of nanospheres as a mask for metal evaporation and etching processes. An optimized approach based on self-assembly at air/water interface with a properly designed apparatus allows the attainment of monolayers of hexagonally closely packed patterns with high long-range order and large area coverage; special strategies are devised in order to protect graphene against damage resulting from surface treatment and further processing steps such as reactive ion etching, which could potentially impair graphene properties. Therefore we demonstrate that nanosphere lithography is a cost-effective solution to create plasmonic patterns on graphene.

  9. Rapid, High-Resolution Forest Structure and Terrain Mapping over Large Areas using Single Photon Lidar

    NASA Astrophysics Data System (ADS)

    Swatantran, Anu; Tang, Hao; Barrett, Terence; Decola, Phil; Dubayah, Ralph

    2016-06-01

    Single photon lidar (SPL) is an innovative technology for rapid forest structure and terrain characterization over large areas. Here, we evaluate data from an SPL instrument - the High Resolution Quantum Lidar System (HRQLS) that was used to map the entirety of Garrett County in Maryland, USA (1700 km2). We develop novel approaches to filter solar noise to enable the derivation of forest canopy structure and ground elevation from SPL point clouds. SPL attributes are compared with field measurements and an existing leaf-off, low-point density discrete return lidar dataset as a means of validation. We find that canopy and ground characteristics from SPL are similar to discrete return lidar despite differences in wavelength and acquisition periods but the higher point density of the SPL data provides more structural detail. Our experience suggests that automated noise removal may be challenging, particularly over high albedo surfaces and rigorous instrument calibration is required to reduce ground measurement biases to accepted mapping standards. Nonetheless, its efficiency of data collection, and its ability to produce fine-scale, three-dimensional structure over large areas quickly strongly suggests that SPL should be considered as an efficient and potentially cost-effective alternative to existing lidar systems for large area mapping.

  10. Rapid, High-Resolution Forest Structure and Terrain Mapping over Large Areas using Single Photon Lidar

    PubMed Central

    Swatantran, Anu; Tang, Hao; Barrett, Terence; DeCola, Phil; Dubayah, Ralph

    2016-01-01

    Single photon lidar (SPL) is an innovative technology for rapid forest structure and terrain characterization over large areas. Here, we evaluate data from an SPL instrument - the High Resolution Quantum Lidar System (HRQLS) that was used to map the entirety of Garrett County in Maryland, USA (1700 km2). We develop novel approaches to filter solar noise to enable the derivation of forest canopy structure and ground elevation from SPL point clouds. SPL attributes are compared with field measurements and an existing leaf-off, low-point density discrete return lidar dataset as a means of validation. We find that canopy and ground characteristics from SPL are similar to discrete return lidar despite differences in wavelength and acquisition periods but the higher point density of the SPL data provides more structural detail. Our experience suggests that automated noise removal may be challenging, particularly over high albedo surfaces and rigorous instrument calibration is required to reduce ground measurement biases to accepted mapping standards. Nonetheless, its efficiency of data collection, and its ability to produce fine-scale, three-dimensional structure over large areas quickly strongly suggests that SPL should be considered as an efficient and potentially cost-effective alternative to existing lidar systems for large area mapping. PMID:27329078

  11. Rapid, High-Resolution Forest Structure and Terrain Mapping over Large Areas using Single Photon Lidar.

    PubMed

    Swatantran, Anu; Tang, Hao; Barrett, Terence; DeCola, Phil; Dubayah, Ralph

    2016-06-22

    Single photon lidar (SPL) is an innovative technology for rapid forest structure and terrain characterization over large areas. Here, we evaluate data from an SPL instrument - the High Resolution Quantum Lidar System (HRQLS) that was used to map the entirety of Garrett County in Maryland, USA (1700 km(2)). We develop novel approaches to filter solar noise to enable the derivation of forest canopy structure and ground elevation from SPL point clouds. SPL attributes are compared with field measurements and an existing leaf-off, low-point density discrete return lidar dataset as a means of validation. We find that canopy and ground characteristics from SPL are similar to discrete return lidar despite differences in wavelength and acquisition periods but the higher point density of the SPL data provides more structural detail. Our experience suggests that automated noise removal may be challenging, particularly over high albedo surfaces and rigorous instrument calibration is required to reduce ground measurement biases to accepted mapping standards. Nonetheless, its efficiency of data collection, and its ability to produce fine-scale, three-dimensional structure over large areas quickly strongly suggests that SPL should be considered as an efficient and potentially cost-effective alternative to existing lidar systems for large area mapping.

  12. Site-specific stamping of graphene micro-patterns over large areas using flexible stamps.

    PubMed

    Chen, Chun-Hu; Reddy, Kongara M; Padture, Nitin P

    2012-06-15

    Site-specific stamping has the potential of becoming a low-cost, high-throughput method for depositing specific-shaped graphene micro-patterns over large areas on a wide variety of substrates. The use of an approach involving flexible stamps presented here represents an important advance towards reaching that potential. This approach entails lithographic creation (dry etching) of high-quality micro-pillar arrays of highly oriented pyrolytic graphite (HOPG) over large areas. This is followed by embedding the micro-pillar arrays in polydimethylsiloxane (PDMS), and detaching them from the HOPG base. This results in flexible stamps containing embedded HOPG micro-pillar arrays with freshly cleaved stamping surfaces. The flexible HOPG/PDMS stamps are then brought into contact with substrate surfaces to site-specifically stamp graphene or few-layer graphene (FLG) arrays over large areas. The freshly cleaved nature of the micro-pillar surfaces in the flexible stamps, the low elastic modulus of the flexible stamps and the elimination of sidewall deposits on the micro-pillars allow for more uniform stamping, relative to the use of stiff HOPG stamps from earlier studies. This approach has the potential to expand the substrate choice for graphene or FLG stamping to include curved and/or flexible substrates that could have an impact on the burgeoning field of flexible/stretchable electronics. PMID:22595887

  13. Site-specific stamping of graphene micro-patterns over large areas using flexible stamps

    NASA Astrophysics Data System (ADS)

    Chen, Chun-Hu; Reddy, Kongara M.; Padture, Nitin P.

    2012-06-01

    Site-specific stamping has the potential of becoming a low-cost, high-throughput method for depositing specific-shaped graphene micro-patterns over large areas on a wide variety of substrates. The use of an approach involving flexible stamps presented here represents an important advance towards reaching that potential. This approach entails lithographic creation (dry etching) of high-quality micro-pillar arrays of highly oriented pyrolytic graphite (HOPG) over large areas. This is followed by embedding the micro-pillar arrays in polydimethylsiloxane (PDMS), and detaching them from the HOPG base. This results in flexible stamps containing embedded HOPG micro-pillar arrays with freshly cleaved stamping surfaces. The flexible HOPG/PDMS stamps are then brought into contact with substrate surfaces to site-specifically stamp graphene or few-layer graphene (FLG) arrays over large areas. The freshly cleaved nature of the micro-pillar surfaces in the flexible stamps, the low elastic modulus of the flexible stamps and the elimination of sidewall deposits on the micro-pillars allow for more uniform stamping, relative to the use of stiff HOPG stamps from earlier studies. This approach has the potential to expand the substrate choice for graphene or FLG stamping to include curved and/or flexible substrates that could have an impact on the burgeoning field of flexible/stretchable electronics.

  14. Step-Controllable Electric-Field-Assisted Nanoimprint Lithography for Uneven Large-Area Substrates.

    PubMed

    Wang, Chunhui; Shao, Jinyou; Tian, Hongmiao; Li, Xiangming; Ding, Yucheng; Li, Ben Q

    2016-04-26

    Large-area nanostructures are widely used in various fields, but fabrication on large-area uneven substrates poses a significant challenge. This study demonstrates a step-controllable electric-field-assisted nanoimprint lithography (e-NIL) method that can achieve conformal contact with uneven substrates for high fidelity nanostructuring. Experiments are used to demonstrate the method where a substrate coated with liquid resist is brought into contact with a flexible template driven by the applied electric field. Theoretical analysis based on the elasticity theory and electro-hydrodynamic theory is carried out. Effective voltage range and the saturation voltage are also discussed. A step-controllable release of flexible template is proposed and demonstrated to ensure the continuous contact between the template and an uneven substrate. This prevents formation of air traps and allows large area conformal contact to be achieved. A combination of Vacuum-electric field assisted step-controllable e-NIL is implemented in the developed prototype. Finally, photonic crystal nanostructures are successfully fabricated on a 4 in., 158 μm bow gallium nitride light-emitting diode epitaxial wafer using the proposed method, which enhance the light extraction property. PMID:27015525

  15. Detection of Steel Fatigue Cracks with Strain Sensing Sheets Based on Large Area Electronics

    PubMed Central

    Yao, Yao; Glisic, Branko

    2015-01-01

    Reliable early-stage damage detection requires continuous monitoring over large areas of structure, and with sensors of high spatial resolution. Technologies based on Large Area Electronics (LAE) can enable direct sensing and can be scaled to the level required for Structural Health Monitoring (SHM) of civil structures and infrastructure. Sensing sheets based on LAE contain dense arrangements of thin-film strain sensors, associated electronics and various control circuits deposited and integrated on a flexible polyimide substrate that can cover large areas of structures. This paper presents the development stage of a prototype strain sensing sheet based on LAE for crack detection and localization. Two types of sensing-sheet arrangements with size 6 × 6 inch (152 × 152 mm) were designed and manufactured, one with a very dense arrangement of sensors and the other with a less dense arrangement of sensors. The sensing sheets were bonded to steel plates, which had a notch on the boundary, so the fatigue cracks could be generated under cyclic loading. The sensors within the sensing sheet that were close to the notch tip successfully detected the initialization of fatigue crack and localized the damage on the plate. The sensors that were away from the crack successfully detected the propagation of fatigue cracks based on the time history of the measured strain. The results of the tests have validated the general principles of the proposed sensing sheets for crack detection and identified advantages and challenges of the two tested designs. PMID:25853407

  16. Testing of a Neon Loop Heat Pipe for Large Area Cryocooling

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Robinson, Franklin Lee

    2014-01-01

    Cryocooling of large areas such as optics, detector arrays, and cryogenic propellant tanks is required for future NASA missions. A cryogenic loop heat pipe (CLHP) can provide a closed-loop cooling system for this purpose and has many advantages over other devices in terms of reduced mass, reduced vibration, high reliability, and long life. A neon CLHP was tested extensively in a thermal vacuum chamber using a cryopump as the heat sink to characterize its transient and steady performance and verify its ability to cool large areas or components. Tests conducted included loop cool-down from the ambient temperature, startup, power cycle, heat removal capability, loop capillary limit and recovery from a dry-out, low power operation, and long duration steady state operation. The neon CLHP demonstrated robust operation. The loop could be cooled from the ambient temperature to subcritical temperatures very effectively, and could start successfully by applying power to both the pump and evaporator without any pre-conditioning. It could adapt to changes in the pump power andor evaporator power, and reach a new steady state very quickly. The evaporator could remove heat loads between 0.25W and 4W. When the pump capillary limit was exceeded, the loop could resume its normal function by reducing the pump power. Steady state operations were demonstrated for up to 6 hours. The ability of the neon loop to cool large areas was therefore successfully verified.

  17. Rapid, High-Resolution Forest Structure and Terrain Mapping over Large Areas using Single Photon Lidar.

    PubMed

    Swatantran, Anu; Tang, Hao; Barrett, Terence; DeCola, Phil; Dubayah, Ralph

    2016-01-01

    Single photon lidar (SPL) is an innovative technology for rapid forest structure and terrain characterization over large areas. Here, we evaluate data from an SPL instrument - the High Resolution Quantum Lidar System (HRQLS) that was used to map the entirety of Garrett County in Maryland, USA (1700 km(2)). We develop novel approaches to filter solar noise to enable the derivation of forest canopy structure and ground elevation from SPL point clouds. SPL attributes are compared with field measurements and an existing leaf-off, low-point density discrete return lidar dataset as a means of validation. We find that canopy and ground characteristics from SPL are similar to discrete return lidar despite differences in wavelength and acquisition periods but the higher point density of the SPL data provides more structural detail. Our experience suggests that automated noise removal may be challenging, particularly over high albedo surfaces and rigorous instrument calibration is required to reduce ground measurement biases to accepted mapping standards. Nonetheless, its efficiency of data collection, and its ability to produce fine-scale, three-dimensional structure over large areas quickly strongly suggests that SPL should be considered as an efficient and potentially cost-effective alternative to existing lidar systems for large area mapping. PMID:27329078

  18. Laser microprocessing and nanoengineering of large-area functional micro/nanostructures

    NASA Astrophysics Data System (ADS)

    Tang, M.; Xie, X. Z.; Yang, J.; Chen, Z. C.; Xu, L.; Choo, Y. S.; Hong, M. H.

    2011-12-01

    Laser microprocessing and nanoengineering are of great interest to both scientists and engineers, since the inspired properties of functional micro/nanostructures over large areas can lead to numerous unique applications. Currently laser processing systems combined with high speed automation ensure the focused laser beam to process various materials at a high throughput and a high accuracy over large working areas. UV lasers are widely used in both laser microprocessing and nanoengineering. However by improving the processing methods, green pulsed laser is capable of replacing UV lasers to make high aspect ratio micro-grooves on fragile and transparent sapphire substrates. Laser micro-texturing can also tune the wetting property of metal surfaces from hydrophilic to super-hydrophobic at a contact angle of 161° without chemical coating. Laser microlens array (MLA) can split a laser beam into multiple laser beams and reduce the laser spot size down to sub-microns. It can be applied to fabricate split ring resonator (SRR) meta-materials for THz sensing, surface plasmonic resonance (SPR) structures for NIR and molding tools for soft lithography. Furthermore, laser interference lithography combined with thermal annealing can obtain a large area of sub-50nm nano-dot clusters used for SPR applications.

  19. A study on the fabrication of nanostructures with high aspect ratio and large area uniformity.

    PubMed

    Sun, Tangyou; Xut, Zhimou; Wang, Shuangbao; Zhao, Wenning; Wu, Xinghui; Liu, Sisi; Liu, Wen; Peng, Jing; Wang, Zhihao; Zhang, Xueming; He, Jian

    2013-03-01

    Nanoimprint lithography (NIL), as a promising next generation lithography method, has the advantages of high throughput, sub-10-nm feature and low cost. However, the requirements, such as the structure with high aspect ratio, large area uniformity, and pattern transfer on nonflat surface, have barely been satisfied at the same time. In this study, the authors present a novel fabrication process by introducing a three-mask-layer (TML) Soft UV NIL technique which proves to be a simple and effective method. The initial mold with low aspect ratio can guarantee the imprint uniformity on large area under a high pressure in NIL. Meanwhile, high aspect ratio structure can be easily obtained due to a high etching selectivity of SiO2 to resist in O2 plasma dry etching. Using the proposed technique to fabricate 40 nm gratings with the aspect ratio as high as 6 is proved successful. Uniform photonic crystal (PC) structures with micrometer scale nonflat steps are obtained on large area. The photoluminescence enhancements of the PC light-emitting diode (LED) fabricated by the proposed method to the one with conventional process and un-patterned LED are 1.6 fold and 2.2 fold, respectively. PMID:23755609

  20. Rapid fabrication of large-area, corrosion-resistant superhydrophobic Mg alloy surfaces.

    PubMed

    Xu, Wenji; Song, Jinlong; Sun, Jing; Lu, Yao; Yu, Ziyuan

    2011-11-01

    A superhydrophobic magnesium (Mg) alloy surface was successfully fabricated via a facile electrochemical machining process, and subsequently covered with a fluoroalkylsilane (FAS) film. The surface morphologies and chemical compositions were investigated using a scanning electron microscope (SEM) equipped with an energy-dispersive spectroscopy (EDS) and a Fourier-transform infrared spectrophotometer (FTIR). The results show hierarchal rough structures and an FAS film with a low surface energy on the Mg alloy surfaces, which confers good superhydrophobicity with a water contact angle of 165.2° and a water tilting angle of approximately 2°. The processing conditions, such as the processing time and removal rate per unit area at a constant removal mass per unit area, were investigated to determine their effects on the superhydrophobicity. Interestingly, when the removal mass per unit area is constant at approximately 11.10 mg/cm(2), the superhydrophobicity does not change with the removal rate per unit area. Therefore, a superhydrophobic Mg alloy surface can be rapidly fabricated based on this property. A large-area superhydrophobic Mg alloy surface was also fabricated for the first time using a small-area moving cathode. The corrosion resistance and durability of the superhydrophobic surfaces were also examined. PMID:22008385

  1. Toward Large-Area Sub-Arcsecond X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    ODell, Stephen L.; Aldcroft, Thomas L.; Allured, Ryan; Atkins, Carolyn; Burrows, David N.; Cao, Jian; Chalifoux, Brandon D.; Chan, Kai-Wing; Cotroneo, Vincenzo; Elsner, Ronald F.; Graham, Michael E.; Gubarev, Mikhail V.; Heilmann, Ralf K.; Johnson-Wilke, Raegan L.; Kilaru, Kiranmayee; Kolodziejczak, Jeffery J.; Lillie, Charles F.; McMuldroch, Stuart; Ramsey, Brian D.; Reid, Paul B.; Riveros, Raul E.; Roche, Jacqueline M.; Saha, Timo T.; Weisskopf, Martin C.; Zhang, William W.

    2014-01-01

    The future of x-ray astronomy depends upon development of x-ray telescopes with larger aperture areas (approx. = 3 square meters) and fine angular resolution (approx. = 1 inch). Combined with the special requirements of nested grazing-incidence optics, the mass and envelope constraints of space-borne telescopes render such advances technologically and programmatically challenging. Achieving this goal will require precision fabrication, alignment, mounting, and assembly of large areas (approx. = 600 square meters) of lightweight (approx. = 1 kilogram/square meter areal density) high-quality mirrors at an acceptable cost (approx. = 1 million dollars/square meter of mirror surface area). This paper reviews relevant technological and programmatic issues, as well as possible approaches for addressing these issues-including active (in-space adjustable) alignment and figure correction.

  2. A large area TOF-tracker device based on multi-gap Resistive Plate Chambers

    NASA Astrophysics Data System (ADS)

    Assis, P.; Bernardino, A.; Blanco, A.; Clemêncio, F.; Carolino, N.; Cunha, O.; Ferreira, M.; Fonte, P.; Lopes, L.; Loureiro, C.; Luz, R.; Mendes, L.; Michel, J.; Neiser, A.; Pereira, A.; Pimenta, M.; Shellard, R.; Traxler, M.

    2016-10-01

    The TOF-tracker concept, the simultaneous measurement of accurate time and bi-dimensional space coordinates in a single gaseous detector, has been previously demonstrated. The detector yielded a time resolution of 77 ps σ along with a bi-dimensional position resolution of 38 μm σ over a full active area of 60 × 60 mm2. In here, we report about a large area, 1550 × 1250 mm2, TOF-tracker device, tested by tracking cosmic muons, yielding a position resolution down to 1.33 mm σ, a simultaneous time resolution of 150 ps σ and 92% detection efficiency, over the entire area of the detector. The sub-millimetre electronic resolution of the readout chain suggests that the position resolution here reported could be dominated by non-corrected systematic effects and therefore it could be yet significantly improved.

  3. Atomically thin lateral p-n junction photodetector with large effective detection area

    NASA Astrophysics Data System (ADS)

    Xu, Zai-Quan; Zhang, Yupeng; Wang, Ziyu; Shen, Yuting; Huang, Wenchao; Xia, Xue; Yu, Wenzhi; Xue, Yunzhou; Sun, Litao; Zheng, Changxi; Lu, Yuerui; Liao, Lei; Bao, Qiaoliang

    2016-12-01

    The widely used photodetector design based on atomically thin transition metal dichalcogenides (TMDs) has a lateral metal-TMD-metal junction with a fairly small, line shape photoresponsive active area at the TMD-electrode interface. Here, we report a highly efficient photodetector with extremely large photoresponsive active area based on a lateral junction of monolayer-bilayer WSe2. Impressively, the separation of the electron-hole pairs (excitons) extends onto the whole 1L-2L WSe2 junction surface. The responsivity of the WSe2 junction photodetector is over 3200 times higher than that of a monolayer WSe2 device and leads to a highest external quantum efficiency of 256% due to the efficient carrier extraction. Unlike the TMD p-n junctions modulated by dual gates or localized doping, which require complex fabrication procedures, our study establishes a simple, controllable, and scalable method to improve the photodetection performance by maximizing the active area for current generation.

  4. A Hybrid Surface Energy Balance Approach for Large Scale Evapotranspiration Estimation and Prediction in Agricultural Areas

    NASA Astrophysics Data System (ADS)

    Neale, C. M.; Vinukollu, R. K.; Chavez, J. L.

    2005-05-01

    Over the last few years, several surface energy balance methods for the estimation of latent heat fluxes from remotely sensed satellite imagery have been introduced and/or refined. These models have shown the ability of obtaining seasonal spatially distributed evapotranspiration fluxes at various scales and over large areas. In the arid western United States, water managers are challenged in balancing the high consumptive use of irrigated agriculture with competing urban and ecological uses of fresh water. Water managers from Irrigation Districts and Federal Agencies such as the US Bureau of Reclamation have a need for improved operational tools for the prediction of evapotranspiration and irrigation water demand on a five to ten day timeframe. The paper will present a hybrid model that couples the surface energy balance approach with a simple empirical reflectance-based crop coefficient model, for estimation and prediction of evapotranspiration over large agricultural areas. The model is applied to a rain-fed intensively cultivated agricultural area, close to Ames, Iowa during the summer of 2002. The satellite, airborne and ground fluxes were collected during the SMACEX 02 experiment. The model is run in both simulation and prediction mode and the derived latent heat fluxes are compared spatially and temporally to aircraft derived fluxes from the USU airborne system and ground measured fluxes at thirteen eddy covariance stations, using appropriate upwind footprint source area functions.

  5. Large area double scattering telescope for balloon-borne studies of neutrons and gamma rays

    NASA Technical Reports Server (NTRS)

    Zych, A. D.; Herzo, D.; Koga, R.; Millard, W. A.; Moon, S.; Ryan, J.; Wilson, R.; White, R. S.; Dayton, B.

    1975-01-01

    A large area double scattering telescope for balloon-borne research is described. It measures the flux, energy and direction of 2-100 MeV neutrons and 0.5-30 MeV gamma rays. These measurements are made using time-of-flight and pulse height analysis techniques with two large tanks of mineral oil liquid scintillator. Results from Monte Carlo calculations of the efficiency, energy resolution and angular resolution are presented and the electronics implementation for the processing of 80 photomultiplier tubes signals will be discussed. The detector weighs 800 kg with a large part of this weight being the liquid scintillator (320 kg). It will be flown at 3 mbars for flight durations up to 40 hours. The first flight is planned for Spring, 1975.

  6. Dark Forward Electrical Test Techniques Developed for Large-Area Photovoltaic Arrays

    NASA Technical Reports Server (NTRS)

    Kerslake, Thomas W.; Scheiman, David A.; Hoffman, David J.

    1998-01-01

    Spacecraft photovoltaic arrays (PVA's) must be carefully handled during ground integration processing and transportation to the launch site. Care is exercised to avoid damage that could degrade on-orbit electrical performance. Because of this damage risk, however, PVA's are typically deployed and illuminated with a light source so performance characteristics can be measured prior to launch. For large-area arrays, such as the Mir Cooperative Solar Array (2.7- by 18-m) and the International Space Station PVA blankets (4.6- by 31.7-m), this integrity check becomes resource intensive. Large test support structures are needed to offload the array during deployment in 1g, and large-aperture illumination equipment is required to uniformly illuminate array panels. Significant program time, funds, and manpower must be allocated for this kind of test program. Alternatively, launch site electrical performance tests can be bypassed with an attendant increase in risk.

  7. Neuronal Heterotopias Affect the Activities of Distant Brain Areas and Lead to Behavioral Deficits.

    PubMed

    Ishii, Kazuhiro; Kubo, Ken-ichiro; Endo, Toshihiro; Yoshida, Keitaro; Benner, Seico; Ito, Yukiko; Aizawa, Hidenori; Aramaki, Michihiko; Yamanaka, Akihiro; Tanaka, Kohichi; Takata, Norio; Tanaka, Kenji F; Mimura, Masaru; Tohyama, Chiharu; Kakeyama, Masaki; Nakajima, Kazunori

    2015-09-01

    Neuronal heterotopia refers to brain malformations resulting from deficits of neuronal migration. Individuals with heterotopias show a high incidence of neurological deficits, such as epilepsy. More recently, it has come to be recognized that focal heterotopias may also show a range of psychiatric problems, including cognitive and behavioral impairments. However, because focal heterotopias are not always located in the brain areas responsible for the symptoms, the causal relationship between the symptoms and heterotopias remains elusive. In this study, we showed that mice with focal heterotopias in the somatosensory cortex generated by in utero electroporation exhibited spatial working memory deficit and low competitive dominance behavior, which have been shown to be closely associated with the activity of the medial prefrontal cortex (mPFC) in rodents. Analysis of the mPFC activity revealed that the immediate-early gene expression was decreased and the local field potentials of the mPFC were altered in the mice with heterotopias compared with the control mice. Moreover, activation of these ectopic and overlying sister neurons using the DREADD (designer receptor exclusively activated by designer drug) system improved the working memory deficits. These findings suggest that cortical regions containing focal heterotopias can affect distant brain regions and give rise to behavioral abnormalities. Significance statement: Recent studies reported that patients with heterotopias have a variety of clinical symptoms, such as cognitive disturbance, psychiatric symptoms, and autistic behavior. However, the causal relationship between the symptoms and heterotopias remains elusive. Here we showed that mice with focal heterotopias in the somatosensory cortex generated by in utero electroporation exhibited behavioral deficits that have been shown to be associated with the mPFC activity in rodents. The existence of heterotopias indeed altered the neural activities of the mPFC, and

  8. Neuronal Heterotopias Affect the Activities of Distant Brain Areas and Lead to Behavioral Deficits.

    PubMed

    Ishii, Kazuhiro; Kubo, Ken-ichiro; Endo, Toshihiro; Yoshida, Keitaro; Benner, Seico; Ito, Yukiko; Aizawa, Hidenori; Aramaki, Michihiko; Yamanaka, Akihiro; Tanaka, Kohichi; Takata, Norio; Tanaka, Kenji F; Mimura, Masaru; Tohyama, Chiharu; Kakeyama, Masaki; Nakajima, Kazunori

    2015-09-01

    Neuronal heterotopia refers to brain malformations resulting from deficits of neuronal migration. Individuals with heterotopias show a high incidence of neurological deficits, such as epilepsy. More recently, it has come to be recognized that focal heterotopias may also show a range of psychiatric problems, including cognitive and behavioral impairments. However, because focal heterotopias are not always located in the brain areas responsible for the symptoms, the causal relationship between the symptoms and heterotopias remains elusive. In this study, we showed that mice with focal heterotopias in the somatosensory cortex generated by in utero electroporation exhibited spatial working memory deficit and low competitive dominance behavior, which have been shown to be closely associated with the activity of the medial prefrontal cortex (mPFC) in rodents. Analysis of the mPFC activity revealed that the immediate-early gene expression was decreased and the local field potentials of the mPFC were altered in the mice with heterotopias compared with the control mice. Moreover, activation of these ectopic and overlying sister neurons using the DREADD (designer receptor exclusively activated by designer drug) system improved the working memory deficits. These findings suggest that cortical regions containing focal heterotopias can affect distant brain regions and give rise to behavioral abnormalities. Significance statement: Recent studies reported that patients with heterotopias have a variety of clinical symptoms, such as cognitive disturbance, psychiatric symptoms, and autistic behavior. However, the causal relationship between the symptoms and heterotopias remains elusive. Here we showed that mice with focal heterotopias in the somatosensory cortex generated by in utero electroporation exhibited behavioral deficits that have been shown to be associated with the mPFC activity in rodents. The existence of heterotopias indeed altered the neural activities of the mPFC, and

  9. Projecting large-scale area changes in land use and land cover for terrestrial carbon analyses.

    PubMed

    Alig, Ralph J; Butler, Brett J

    2004-04-01

    One of the largest changes in US forest type areas over the last half-century has involved pine types in the South. The area of planted pine has increased more than 10-fold since 1950, mostly on private lands. Private landowners have responded to market incentives and government programs, including subsidized afforestation on marginal agricultural land. Timber harvest is a crucial disturbance affecting planted pine area, as other forest types are converted to planted pine after harvest. Conversely, however, many harvested pine plantations revert to other forest types, mainly due to passive regeneration behavior on nonindustrial private timberlands. We model land use and land cover changes as a basis for projecting future changes in planted pine area, to aid policy analysts concerned with mitigation activities for global climate change. Projections are prepared in two stages. Projected land use changes include deforestation due to pressures to develop rural land as the human population expands, which is a larger area than that converted from other rural lands (e.g., agriculture) to forestry. In the second stage, transitions among forest types are projected on land allocated to forestry. We consider reforestation, influences of timber harvest, and natural succession and disturbance processes. Baseline projections indicate a net increase of about 5.6 million ha in planted pine area in the South over the next 50 years, with a notable increase in sequestered carbon. Additional opportunities to expand pine plantation area warrant study of landowner behavior to aid in designing more effective incentives for inducing land use and land cover changes to help mitigate climate change and attain other goals.

  10. Results of Large Area Crop Inventory Experiment (LACIE) drought analysis (South Dakota drought 1976)

    NASA Technical Reports Server (NTRS)

    Thompson, D. R.

    1976-01-01

    LACIE using techniques developed from the southern Great Plains drought analysis indicated the potential for drought damage in South Dakota. This potential was monitored and as it became apparent that a drought was developing, LACIE implemented some of the procedures used in the southern Great Plains drought. The technical approach used in South Dakota involved the normal use of LACIE sample segments (5 x 6 nm) every 18 days. Full frame color transparencies (100 x 100 nm) were used on 9 day intervals to identify the drought area and to track overtime. The green index number (GIN) developed using the Kauth transformation was computed for all South Dakota segments and selected North Dakota segments. A scheme for classifying segments as drought affected or not affected was devised and tested on all available 1976 South Dakota data. Yield model simulations were run for all CRD's Crop Reporting District) in South Dakota.

  11. 20 CFR 645.525 - What special consideration will be given to rural areas and cities with large concentrations of...

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... rural areas and cities with large concentrations of poverty? 645.525 Section 645.525 Employees' Benefits... cities with large concentrations of poverty? (a) Competitive grant awards will be targeted to geographic... rural areas and cities with large concentrations of residents living in poverty. (b) Grant...

  12. 20 CFR 645.525 - What special consideration will be given to rural areas and cities with large concentrations of...

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... rural areas and cities with large concentrations of poverty? 645.525 Section 645.525 Employees' Benefits... cities with large concentrations of poverty? (a) Competitive grant awards will be targeted to geographic... rural areas and cities with large concentrations of residents living in poverty. (b) Grant...

  13. 20 CFR 645.525 - What special consideration will be given to rural areas and cities with large concentrations of...

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... rural areas and cities with large concentrations of poverty? 645.525 Section 645.525 Employees' Benefits... cities with large concentrations of poverty? (a) Competitive grant awards will be targeted to geographic... rural areas and cities with large concentrations of residents living in poverty. (b) Grant...

  14. 20 CFR 645.525 - What special consideration will be given to rural areas and cities with large concentrations of...

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... rural areas and cities with large concentrations of poverty? 645.525 Section 645.525 Employees' Benefits... cities with large concentrations of poverty? (a) Competitive grant awards will be targeted to geographic... rural areas and cities with large concentrations of residents living in poverty. (b) Grant...

  15. 20 CFR 645.525 - What special consideration will be given to rural areas and cities with large concentrations of...

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... rural areas and cities with large concentrations of poverty? 645.525 Section 645.525 Employees' Benefits... cities with large concentrations of poverty? (a) Competitive grant awards will be targeted to geographic... rural areas and cities with large concentrations of residents living in poverty. (b) Grant...

  16. Flight Qualification And Production Results With Large Area Space Solar Cells And Panel Assembly

    NASA Astrophysics Data System (ADS)

    Sharma, S. K.; Hanley, James; Jun, Bogim; Bardfield, Rina; Stone, Beth

    2011-10-01

    Spectrolab's product roadmap provides improvement in product performance in parallel with continuous cost reduction to maintain competitive standing in our industry. Product performance improvement is achieved by developing higher efficiency solar cells (e.g. 29.5% XTJ and 33% IMM cells).Reduced product cost is achieved historically through a variety of means including yield improvements, direct material cost reductions, process changes, and most recently, a transition to large area cell configurations (e.g. "LEONE" at 59.65 cm2). Spectrolab has successfully completed the qualification of its latest triple junction space solar cell, the 29.5% 2 XTJ (26.62 cm ), per AIAA-S-111-2005 - augmented by additional Spectrolab testing. Large area LEONE UTJ and XTJ cells (59.65 cm2 from 100 mm diameter germanium wafer) have also been qualified. Use of these large area cells has resulted in the reduction of solar panel cost, add-on mass and manufacturing cycle time for programs. This evolution to larger area cells is the result of a strategic cost reduction effort initiated in 2006; the first step of which was to manufacture the largest possible cells (LEONE) using the 100 mm germanium (Ge) wafer. In flight production since 2007, the LEONE UTJ cell has now completed rigorous qualification testing to 15,549 GEO (Geosynchronous orbit) and 66,060 LEO (Low Earth Orbit) thermal cycles. Over 53,000 LEONE UTJ cells, including more than 27,000 cells on panels delivered to flight programs, have been produced to date. The on-orbit performance of the LEONE UTJ cells is nominal. Finally, progress on the second step of our strategic cost reduction effort towards larger cells and less piece part handling is presented. This effort involves the establishment of a 150 mm Ge -based manufacturing infrastructure.

  17. Sensing sheets based on large area electronics for fatigue crack detection

    NASA Astrophysics Data System (ADS)

    Yao, Yao; Glisic, Branko

    2015-03-01

    Reliable early-stage damage detection requires continuous structural health monitoring (SHM) over large areas of structure, and with high spatial resolution of sensors. This paper presents the development stage of prototype strain sensing sheets based on Large Area Electronics (LAE), in which thin-film strain gauges and control circuits are integrated on the flexible electronics and deposited on a polyimide sheet that can cover large areas. These sensing sheets were applied for fatigue crack detection on small-scale steel plates. Two types of sensing-sheet interconnects were designed and manufactured, and dense arrays of strain gauge sensors were assembled onto the interconnects. In total, four (two for each design type) strain sensing sheets were created and tested, which were sensitive to strain at virtually every point over the whole sensing sheet area. The sensing sheets were bonded to small-scale steel plates, which had a notch on the boundary so that fatigue cracks could be generated under cyclic loading. The fatigue tests were carried out at the Carleton Laboratory of Columbia University, and the steel plates were attached through a fixture to the loading machine that applied cyclic fatigue load. Fatigue cracks then occurred and propagated across the steel plates, leading to the failure of these test samples. The strain sensor that was close to the notch successfully detected the initialization of fatigue crack and localized the damage on the plate. The strain sensor that was away from the crack successfully detected the propagation of fatigue crack based on the time history of measured strain. Overall, the results of the fatigue tests validated general principles of the strain sensing sheets for crack detection.

  18. Large-area CMOS solid-state photomultipliers and recent developments

    NASA Astrophysics Data System (ADS)

    Johnson, Erik B.; Stapels, Christopher J.; Jie Chen, Xiao; Augustine, Frank L.; Christian, James F.

    2011-10-01

    The CMOS solid-state photomultiplier (SSPM) is an array of Geiger avalanche photodiodes (GPD) read out in parallel. These devices are not susceptible to magnetic fields, less expensive to fabricate than many other photodetector technologies, compact, and allow for on-chip integration of signal processing circuits. A number of nuclear detection applications require detector sizes on the order of 1 cm. Standard silicon fabrication technology limits the size of the SSPM die, and tiling of the silicon die can result in large-area devices but results in dead space between die for bonding purposes. Radiation Monitoring Devices (RMD) has fabricated 1×1 cm SSPM arrays on a single die. The size of these devices is large enough to provide an alternative detector for scintillation detector applications compared to photomultiplier tubes. Although the size increases the dark noise, we will demonstrate that the large-area SSPM can provide a PMT-like response for 22Na gamma rays using an LYSO crystal. Each of the noise terms associated with the large-area SSPM is discussed, quantifying the cross talk and after pulse multipliers, which are scaling factors to the gain to account for the additional output charge from the SSPM. The excess noise factor associated with cross talk and after pulsing has a linear dependence on the multiplier term. The signal and noise terms have been compiled to provide the best operating voltage of roughly 6 V above breakdown for a 1×1 cm CMOS SSPM to be operated with a short integration time (<10 ns) and at 0 °C.

  19. Aggressive experience affects the sensitivity of neurons towards pharmacological treatment in the hypothalamic attack area.

    PubMed

    Haller, J; Abrahám, I; Zelena, D; Juhász, G; Makara, G B; Kruk, M R

    1998-09-01

    Early investigators of brain stimulation-evoked complex behaviours (attack, escape, feeding, self-grooming, sexual behaviour) reported that experience may affect the behavioural outcome of brain stimulation. This intriguing example of functional neuronal plasticity was later totally neglected. The present experiment investigated the behavioural outcome of in vivo microdialysis perfusion of the glutamate agonist kainate and/or the GABAA antagonist bicuculline into the hypothalamic attack area (HAA) of (1) animals naive to dyadic encounters; (2) animals with a recent aggressive experience (the probe being implanted 6-24 h after the last of a series of dyadic encounters); and (3) animals with an earlier aggressive experience (probe being implanted 2 weeks after the last aggressive experience). On the experimental day, rats received two 5-min infusions during a dyadic encounter lasting 35 min with an unknown opponent. Flow rate was 1.5-2 microliters/min, drug concentrations were 1.8 x 10(-5) and 1.5 x 10(-5) M for kainate and bicuculline, respectively. Behaviour was analysed before, during and after perfusions. Only the combined kainate + bicuculline treatment had significant effects on behaviour at the doses studied. A significant increase in aggressive behaviour was elicited only in animals with a recent aggressive experience, while naive animals and with an earlier experience responded to the treatments by grooming. These results appear to support early observations indicating that one important aspect of brain stimulation effects is previous experience. PMID:9832932

  20. Socio-economic factors affecting the conservation of natural woodlands in Central Riyadh Area - Saudi Arabia.

    PubMed

    Al-Subaiee, Faisal Sultan

    2016-05-01

    This study aimed to identify some socioeconomic factors affecting local people in central Riyadh area for the utilization of wood and other energy sources in cooking and heating in order to develop some recommendations for conserving woodlands. The study results revealed that gas is the most common energy source used for cooking with a mean usage level of 2.79 (SD = 0.58). On the other hand, wood ranked first for heating with the highest mean, usage level of 1.90 (SD = 1.06). However, electricity and gas as sources of energy for heating ranked second and third with mean usage level of 1.81 and 0.80 respectively. The study revealed that local people with the university education were significantly making higher use of electricity for both cooking and heating and those with no formal education ranked the highest on wood use for both cooking and heating. In addition, those living in traditional houses significantly used more wood for cooking than those living in villas and apartments. Also, local people with high income levels significantly were using more electricity for heating than others. The study recommended conducting extension and environmental awareness raising programs to enhance local residents' adoption of wood substitutes, promoting employment opportunities for unemployed locals, and subsidizing prices of alternative energy sources. PMID:27081355

  1. Socio-economic factors affecting the conservation of natural woodlands in Central Riyadh Area - Saudi Arabia.

    PubMed

    Al-Subaiee, Faisal Sultan

    2016-05-01

    This study aimed to identify some socioeconomic factors affecting local people in central Riyadh area for the utilization of wood and other energy sources in cooking and heating in order to develop some recommendations for conserving woodlands. The study results revealed that gas is the most common energy source used for cooking with a mean usage level of 2.79 (SD = 0.58). On the other hand, wood ranked first for heating with the highest mean, usage level of 1.90 (SD = 1.06). However, electricity and gas as sources of energy for heating ranked second and third with mean usage level of 1.81 and 0.80 respectively. The study revealed that local people with the university education were significantly making higher use of electricity for both cooking and heating and those with no formal education ranked the highest on wood use for both cooking and heating. In addition, those living in traditional houses significantly used more wood for cooking than those living in villas and apartments. Also, local people with high income levels significantly were using more electricity for heating than others. The study recommended conducting extension and environmental awareness raising programs to enhance local residents' adoption of wood substitutes, promoting employment opportunities for unemployed locals, and subsidizing prices of alternative energy sources.

  2. Polycyclic aromatic hydrocarbons (PAHs) in Mississippi seafood from areas affected by the Deepwater Horizon Oil Spill.

    PubMed

    Xia, Kang; Hagood, Gale; Childers, Christina; Atkins, Jack; Rogers, Beth; Ware, Lee; Armbrust, Kevin; Jewell, Joe; Diaz, Dale; Gatian, Nick; Folmer, Henry

    2012-05-15

    Seafood samples from the fishing ground closure areas of Mississippi Gulf Coast that were affected by the Deepwater Horizon Oil Spill Disaster were collected and analyzed for twenty-five 2- to 6-ring PAHs, about one month after the first day of incident. A total of 278 seafood samples consisting of 86 fishes, 65 shrimps, 59 crabs, and 68 oysters were collected and analyzed weekly from May 27, 2010 until October 2010 and monthly thereafter until August 2011. Statistically higher levels of total PAHs were detected in all four types of seafood samples during early part of the sampling period compared to the later months. There was no significant concentration difference between PAHs detected in the oyster samples for the current study and the 10-year historical data from the NOAA Mussel Watch program. The PAH levels in the tested seafood samples were similar to those detected in commonly consumed processed foods purchased from local grocery stores and restaurants. Overall, the levels of PAHs in all the tested seafood samples collected within one-year period after the Oil Spill incident were far below the public health Levels of Concern (LOC) established jointly by the NOAA/FDA/Gulf Coast states under the protocol to reopen state and federal waters.

  3. Modified and double-clad large mode-area leakage channel fibers for extreme temperature conditions

    NASA Astrophysics Data System (ADS)

    Thavasi Raja, G.; Varshney, Shailendra K.

    2015-03-01

    Recently large-mode-area hybrid leakage channel fibers (HLCFs) were reported to overcome the limitation on mode area with single-mode (SM) operation for the practical bending radius of 7.5 cm at the preferred wavelength of 1064 nm. In this paper, we present the effects of a thermally induced refractive index change on the mode area of bend-compensated extremely LMA modified HLCFs (M-HLCFs) and double-clad M-HLCFs. A full-vectorial finite-element method-based modal solver is used to obtain the modal characteristics of M-HLCFs in various heat load conditions. Numerical simulations reveal that the effective mode area of M-HLCFs is ˜1433 μm2 at room temperature, which marginally decreases to ˜1387 μm2 while SM operation is maintained when the temperature distribution rises to ˜125 °C over the fiber geometry during high-power operations. We have also investigated a double-clad M-HLCF design exhibiting a mode area > ˜ 1000 μm2 for all heat load density variations up to a maximum of 12 × 109 W m-3, corresponding to a 250 °C temperature in the center of the fiber core region.

  4. Controlled Cu nanoparticle growth on wrinkle affecting deposition of large scale graphene

    NASA Astrophysics Data System (ADS)

    Ahmed, Mohsin; Uddin, Md Jasim; Rahman, Muhammad Anisur; Kishi, Naoki; Soga, Tetsuo

    2016-09-01

    For Chemical Vapor Deposition (CVD) grown graphene on Cu substrate, deviation from atomic orientation in crystals may be resulted from diffusion of abnormalities in the form of Cu nanoparticle (NP) formation or defects and affects graphene quality and properties drastically. However, for the uniform graphene deposition, mechanism of nanoparticle formation and its suppression procedure need to be better understood. We report growth of graphene, affected by Cu nanoparticles (NPs) emergence on Cu substrates. In the current study, growth of these nanoparticles has been suppressed by fine tuning of carrier gas by two-fold gas insertion mechanism and hence, quality and uniformity of graphene is significantly improved. It has been also observed that during the deposition by CVD, Cu nanoparticles cluster preferentially on wrinkles or terrace of the Cu surface. Composition of NP is extensively studied and found to be the oxide nanoparticle of Cu. Our result, controlled NP growth affecting deposition of graphene layer would provide useful insight on the growth of uniform and high quality Single layer or bilayer graphene for numerous electronics applications.

  5. Spatial distribution of gases emitted from large urban areas derived from SF6 measurements

    NASA Astrophysics Data System (ADS)

    Santella, N.; Ho, D.; Schlosser, P.; Stute, M.

    2004-12-01

    A 6 year (1998-2003) long, high-resolution, time series of atmospheric SF6 from Lamont Doherty Earth Observatory (LDEO), ~ 25 km north of New York City (NYC), has shown that SF6 mixing ratios are highly variable and elevated above remote atmosphere values. Subsequent measurements in soil air (which functions as a low-pass filter) around the New York metropolitan area demonstrate that elevated SF6 levels are widespread. Mapping of the elevated SF6 levels caused by local emissions in NYC allows us to determine the region influenced by emissions from this urban area. To determine if such elevated SF6 levels are typical for large US cities, soil air measurements were repeated in five major urban areas in the US. In each case, significant elevation of SF6 mixing ratios above remote atmosphere values was observed. SF6 emissions from the electrical industry in NYC are particular high, resulting in average mixing ratios within the city in excess of remote atmosphere values by up to 200 %, with elevated levels persisting out to ca. 200 km. Emissions from Boston, Philadelphia, Washington DC/Baltimore, and Tucson appear average for large cities in the U.S.A. with maximum mixing ratios 50-100% above background, and elevated levels detected over tens of kilometers. Using a simplistic atmospheric dispersion model and emissions records, the observed distribution of average SF6 mixing ratios around NYC can be reproduced. This indicates that studies using similar methods, with higher spatial resolution, coupled with modeling of atmospheric transport may allow independent estimates of emissions of SF6, or other inert gases. Observed distributions of SF6 are indicative of average atmospheric transport patterns, and elevated levels of SF6 in remote areas demonstrate significant influence of air masses from urban areas. Comparison of SF6 timeseries at LDEO and Harvard Forest, 205 km to the northeast, demonstrate transport of individual pollution events.

  6. Using large area imaging to integrate biogeochemical data across spatial scales

    NASA Astrophysics Data System (ADS)

    Sapers, H. M.; Laquerre, A.; Phaneuf, M. W.; Osinski, G. R.

    2014-12-01

    Large Area Imaging (LAI) systems such as the Carl Zeiss "Atlas" module allow acquisition of SEM images on the scale of millimeters to centimeters with an image resolution ranging from nanometers to micrometers. This provides researchers with the powerful capability to investigate large areas of up to tens of millimeters in scale and expand anywhere within these areas to see details on the micrometer to nanometer scale while retaining full contextual information regarding the areas under investigation. Biogeochemical processes operate on multiple scales and evidence of these phenomena can be difficult to observe across scales. For example, microbial etching of glass occurs on a nanometer scale as organic acids locally lower pH and destabilize Si-O bonds. However, interpreting a pattern of glass etching as abiotic or biogenic depends on observations at the micrometer to centimeter scale to assess evidence for microbial populations and/or biological behavior, assess fluid flow, changes in elemental composition and mineralogy. LAI is particularly suited to the investigation of multi-scale, interdisciplinary biogeochemical datasets. Using LAI we have generated contiguous image data at resolutions as high as 100 nm (pixel size) for areas approaching 25 cm2, using backscattered and secondary electrons in both traditional high vacuum and variable pressure SEM modes. Image stitching produces seamless mosaics composed of multiple image tiles; mosaic acquisition times can be as little as a few hours of fully automated operation. Using this primary information, additional micrometer-scale data sets such as EDX spectroscopy, millimeter-scale datasets such as transmitted light photomicrographs, and nanometer-scale information such as synchrotron-based spectroscopy, can be registered and fused with the LAI SEM images. LAI and data fusion facilitates critical connections across spatial scales to test hypotheses that cross the threshold of traditional microscopy methods.

  7. GLAST LARGE AREA TELESCOPE: DAILY SURVEY OF HIGH-ENERGY SKY

    SciTech Connect

    Kamae, T

    2003-12-12

    GLAST Large Area Telescope was proposed to NASA in 1999 as follow-up of EGRET on-board Compton Gamma-Ray Observatory by an international collaboration. The proposal has been approved as a part of the GLAST observatory mission in its capability to explore w die range of astrophysics with 5-40 times higher sensitivity and extended energy coverage (20 MeV to 300 GeV) than EGRET. The instrument consists of 16 towers of e{sup +}e{sup -} pair tracker, 16 blocks of segmented electro-magnetic calorimeter, and a st of anti-coincidence plastic scintillator tiles covering the tracker towers. It will have 5-10 times larger on-axis effective area, 6 times wider field-of-view (FOV), and up to 5 times better angular resolution when compared with EGRET. The Large Area Telescope will cover about 40% of the sky above the Earth's horizon in its FOV at any given time and will scan nearly the entire Universe every orbit ({approx} 90min): about 20% of Gamma-Ray Bursts will be observed from the onset of the bursts to the initial after-glow phase; all longer-lasting transients and variabilities will be detected daily at the improved sensitivity.

  8. Widefield TSCSPC-systems with large-area-detectors: application in simultaneous multi-channel-FLIM

    NASA Astrophysics Data System (ADS)

    Stepanov, Sergei; Bakhlanov, Sergei; Drobchenko, Evgeny; Eckert, Hann-Jörg; Kemnitz, Klaus

    2010-11-01

    Novel proximity-type Time- and Space-Correlated Single Photon Counting (TSCSPC) crossed-delay-line (DL)- and multi-anode (MA)-systems of outstanding performance and homogeneity were developed, using large-area detector heads of 25 and 40 mm diameter. Instrument response functions IRF(space) = (60 +/- 5) μm FWHM and IRF(time) = (28 +/- 3) ps FWHM were achieved over the full 12 cm2 area of the detector. Deadtime at throughput of 105 cps is 10% for "high-resolution" system and 5% in the "video"-system at 106 cps, at slightly reduced time- and space resolution. A fluorescence lifetime of (3.5 +/- 1) ps can be recovered from multi-exponential dynamics of a single living cyanobacterium (Acaryochloris marina). The present large-area detectors are particularly useful in simultaneous multichannel applications, such as 2-colour anisotropy or 4-colour lifetime imaging, utilizing dual- or quad-view image splitters. The long-term stability, low- excitation-intensity (< 100 mW/cm2) widefield systems enable minimal-invasive observation, without significant bleaching or photodynamic reactions, thus allowing long-period observation of up to several hours in living cells.

  9. Large area graphene growth on 6H-SiC(0001)

    NASA Astrophysics Data System (ADS)

    Johansson, L. I.; Virojanadara, C.; Syväjärvi, M.; Yakimova, R.; Zakharov, A. A.; Balasubramanian, T.

    2009-03-01

    Large area graphene growth on commercial Si-face on-axis 6H-SiC(0001) is demonstrated in this work. Samples were produced in a prototype of an inductively heated furnace. The growth was carried out in strongly isothermal conditions at a temperature of 2000 C and at an ambient argon pressure of 1 atm. The quality and thickness of the graphene layers grown, using this ex situ method, were investigated using PES, ARPES), LEED as well as LEEM, PEEM micro-LEED and micro-PES at specifically defined small areas. Our results show that single layer graphene is formed over quite large areas on the sample but that two different domains can exist on some parts. A comparison with an in situ graphene sample, prepared by resistive heating to 1275 C, was made. The results then obtained were similar to earlier findings [1-2] and showed that the size of the graphene flakes were very small compared to those obtained on the samples prepared with our ex situ method. [3pt] [1]. T. Ohta, F. El Gabaly, A. Bostwick, J.L. McChesney, K.V. Emtsev, A.K. Schmid, Th. Seyller, K. Horn, E. Rotenberg, New. J. Phys. 10 023034 (2008).[0pt] [2]. J.B. Hannon and R. M. Tromp, Phys. Rev. B 77 241404 (2008).

  10. Large area and deep sub-wavelength interference lithography employing odd surface plasmon modes

    PubMed Central

    Liu, Liqin; Luo, Yunfei; Zhao, Zeyu; Zhang, Wei; Gao, Guohan; Zeng, Bo; Wang, Changtao; Luo, Xiangang

    2016-01-01

    In this paper, large area and deep sub-wavelength interference patterns are realized experimentally by using odd surface plasmon modes in the metal/insulator/metal structure. Theoretical investigation shows that the odd modes possesses much higher transversal wave vector and great inhibition of tangential electric field components, facilitating surface plasmon interference fringes with high resolution and contrast in the measure of electric field intensity. Interference resist patterns with 45 nm (∼λ/8) half-pitch, 50 nm depth, and area size up to 20 mm × 20 mm were obtained by using 20 nm Al/50 nm photo resist/50 nm Al films with greatly reduced surface roughness and 180 nm pitch exciting grating fabricated with conventional laser interference lithography. Much deeper resolution down to 19.5 nm is also feasible by decreasing the thickness of PR. Considering that no requirement of expensive EBL or FIB tools are employed, it provides a cost-effective way for large area and nano-scale fabrication. PMID:27466010

  11. Further advancements for large area-detector based computed tomography system

    SciTech Connect

    Davis, A. W.; Keating, S. C.; Claytor, T. N.

    2001-01-01

    We present advancements made to a large area-detector based system for industrial x-ray computed tomography. Past performance improvements in data acquisition speeds were made by use of high-resolution large area, flat-panel amorphous-silicon (a-Si) detectors. The detectors have proven, over several years, to be a robust alternative to CCD-optics and image intensifier CT systems. These detectors also provide the advantage of area detection as compared with the single slice geometry of linear array systems. New advancements in this system include parallel processing of sinogram reconstructions, improved visualization software and migration to frame-rate a-Si detectors. Parallel processing provides significant speed improvements for data reconstruction, and is implemented for parallel-beam, fan-beam and Feldkamp cone-beam reconstruction algorithms. Reconstruction times are reduced by an order of magnitude by use of a cluster of ten or more equal-speed computers. Advancements in data visualization are made through interactive software, which allows interrogation of the full three-dimensional dataset. Inspection examples presented in this paper include an electromechanical device, a nonliving biological specimen and a press-cast plastic specimen. We also present a commonplace item for the benefit of the layperson.

  12. Large area and deep sub-wavelength interference lithography employing odd surface plasmon modes.

    PubMed

    Liu, Liqin; Luo, Yunfei; Zhao, Zeyu; Zhang, Wei; Gao, Guohan; Zeng, Bo; Wang, Changtao; Luo, Xiangang

    2016-01-01

    In this paper, large area and deep sub-wavelength interference patterns are realized experimentally by using odd surface plasmon modes in the metal/insulator/metal structure. Theoretical investigation shows that the odd modes possesses much higher transversal wave vector and great inhibition of tangential electric field components, facilitating surface plasmon interference fringes with high resolution and contrast in the measure of electric field intensity. Interference resist patterns with 45 nm (∼λ/8) half-pitch, 50 nm depth, and area size up to 20 mm × 20 mm were obtained by using 20 nm Al/50 nm photo resist/50 nm Al films with greatly reduced surface roughness and 180 nm pitch exciting grating fabricated with conventional laser interference lithography. Much deeper resolution down to 19.5 nm is also feasible by decreasing the thickness of PR. Considering that no requirement of expensive EBL or FIB tools are employed, it provides a cost-effective way for large area and nano-scale fabrication.

  13. Large area and deep sub-wavelength interference lithography employing odd surface plasmon modes

    NASA Astrophysics Data System (ADS)

    Liu, Liqin; Luo, Yunfei; Zhao, Zeyu; Zhang, Wei; Gao, Guohan; Zeng, Bo; Wang, Changtao; Luo, Xiangang

    2016-07-01

    In this paper, large area and deep sub-wavelength interference patterns are realized experimentally by using odd surface plasmon modes in the metal/insulator/metal structure. Theoretical investigation shows that the odd modes possesses much higher transversal wave vector and great inhibition of tangential electric field components, facilitating surface plasmon interference fringes with high resolution and contrast in the measure of electric field intensity. Interference resist patterns with 45 nm (∼λ/8) half-pitch, 50 nm depth, and area size up to 20 mm × 20 mm were obtained by using 20 nm Al/50 nm photo resist/50 nm Al films with greatly reduced surface roughness and 180 nm pitch exciting grating fabricated with conventional laser interference lithography. Much deeper resolution down to 19.5 nm is also feasible by decreasing the thickness of PR. Considering that no requirement of expensive EBL or FIB tools are employed, it provides a cost-effective way for large area and nano-scale fabrication.

  14. Large-area x-ray topographic screening of II-VI substrates and epilayers

    NASA Astrophysics Data System (ADS)

    Di Marzio, Don; Larson, David J., Jr.; Casagrande, Louis G.; Wu, Jun; Dudley, Michael; Tobin, Stephen P.; Norton, Peter W.

    1994-07-01

    A crucial aspect of process control in II-VI based device fabrication is the detailed monitoring of material properties, particularly structural quality. We have developed a method of mapping structural defects over large wafer areas using synchrotron white beam x-ray topography and have used it to characterize large area single crystal CdZnTe substrates and LPE HgCdTe epilayers grown on them. The synchrotron white beam technique produces high resolution topographic images of whole wafers regardless of long range strain, and the multiple images generated as a result of the polychromatic white beam (Laue geometry) provide an automatic defect depth profiling. The topographs reveal various types of defect structure in the CdZnTe substrates, and we have compared these topographic images to IR micrographs and x-ray rocking curve maps. Defect structures as revealed by the x-ray topographs were then followed from the CdZnTe substrates to the LPE grown HgCdTe epilayers. Epilayer topographs were also compared to conventional optical micrographs as well as with x-ray rocking curve maps. Finally, a scanning stage was constructed to topographically image large wafers and boule slabs.

  15. Upscaling of integrated photoelectrochemical water-splitting devices to large areas

    PubMed Central

    Turan, Bugra; Becker, Jan-Philipp; Urbain, Félix; Finger, Friedhelm; Rau, Uwe; Haas, Stefan

    2016-01-01

    Photoelectrochemical water splitting promises both sustainable energy generation and energy storage in the form of hydrogen. However, the realization of this vision requires laboratory experiments to be engineered into a large-scale technology. Up to now only few concepts for scalable devices have been proposed or realized. Here we introduce and realize a concept which, by design, is scalable to large areas and is compatible with multiple thin-film photovoltaic technologies. The scalability is achieved by continuous repetition of a base unit created by laser processing. The concept allows for independent optimization of photovoltaic and electrochemical part. We demonstrate a fully integrated, wireless device with stable and bias-free operation for 40 h. Furthermore, the concept is scaled to a device area of 64 cm2 comprising 13 base units exhibiting a solar-to-hydrogen efficiency of 3.9%. The concept and its successful realization may be an important contribution towards the large-scale application of artificial photosynthesis. PMID:27601181

  16. High-resolution and large-area nanoparticle arrays using EUV interference lithography.

    PubMed

    Karim, Waiz; Tschupp, Simon Andreas; Oezaslan, Mehtap; Schmidt, Thomas J; Gobrecht, Jens; van Bokhoven, Jeroen A; Ekinci, Yasin

    2015-04-28

    Well-defined model systems are needed for better understanding of the relationship between optical, electronic, magnetic, and catalytic properties of nanoparticles and their structure. Chemical synthesis of metal nanoparticles results in large size and shape dispersion and lack of lateral order. In contrast, conventional top-down lithography techniques provide control over the lateral order and dimensions. However, they are either limited in resolution or have low throughput and therefore do not enable the large patterning area needed to obtain good signal-to-noise ratio in common analytical and characterization techniques. Extreme ultraviolet (EUV) lithography has the throughput and simplicity advantages of photolithography as well as high resolution due to its wavelength. Using EUV achromatic Talbot lithography, we have obtained 15 nm particle arrays with a periodicity of about 100 nm over an area of several square centimeters with high-throughput enabling the use of nanotechnology for fabrication of model systems to study large ensembles of well-defined identical nanoparticles with a density of 10(10) particles cm(-2). PMID:25826457

  17. Spatial and temporal self shaping for large mode area fiber laser system

    NASA Astrophysics Data System (ADS)

    Deng, Ying; Wang, Jian-jun; Lin, Hong-huan; Li, Jing; Zhang, Rui; Xu, Dang-peng; Zhu, Na; Huang, Zhi-hua

    2011-10-01

    In order to suppress the mode noise of large mode area fiber amplifier system and enhance the signal to noise ratio of the output pulse, spatial and temporal self shaping for large mode area fiber laser system are studied in this paper. For removing off the mode noise, method of beam's spacial self-shaping based on mode matching is used. By the method of mode matching, the cladding mode are removed off clearly. Then a large mode fiber amplifier with a strictly single mode is obtained. For enhancing the signal to noise ratio of the output pulse, method of beam's temoral self-shaping based on Optical Kerr effct in fiber is used. By using Optical Kerr effect, the pulse get nonlinear polarization ratation, which make pulses selfly shaped in time and the ASE pedestal is removed off clearly. As a result, by spatial and temporal self shaping, cleared pulses with a strictly single mode in spatial and cleaned pulses without ASE pedestal are obtained.

  18. Large-area patterned substrates for micromagnetic actuation of superparamagnetic microbeads

    NASA Astrophysics Data System (ADS)

    Ouk, Minae; Beach, Geoffrey

    2014-03-01

    Superparamagnetic microbeads (SBs) are widely used to capture biological entities in a fluid environment. Chip-based magnetic actuation provides a means to transport SBs in lab-on-a-chip technologies. This is usually accomplished using the stray field from patterned magnetic microstructures, or domain walls in magnetic nanowires. However, lithographic patterning over a large area is costly and impractical using conventional techniques such as electron beam lithography. Here we use a simple floating-transfer technique for large-area self-assembly of polystyrene microspheres on a Si wafer to produce lithographic masks texturing a substrate. Hexagonal patterns are used as lift-off and etching masks to create magnetic dot and anti-dot arrays in CoFe thin films, with a size and spacing that can be tuned via sphere diameter and RIE etch time. Using a rotating magnetic fields, we show that these magnetically-patterned substrates can transport SBs across large distances on the wafer surface, opening the possibility to augment or replace microfluidic actuation for long distance transport. Supported by the MIT Deshpande Center.

  19. Microwave purification of large-area horizontally aligned arrays of single-walled carbon nanotubes.

    PubMed

    Xie, Xu; Jin, Sung Hun; Wahab, Muhammad A; Islam, Ahmad E; Zhang, Chenxi; Du, Frank; Seabron, Eric; Lu, Tianjian; Dunham, Simon N; Cheong, Hou In; Tu, Yen-Chu; Guo, Zhilin; Chung, Ha Uk; Li, Yuhang; Liu, Yuhao; Lee, Jong-Ho; Song, Jizhou; Huang, Yonggang; Alam, Muhammad A; Wilson, William L; Rogers, John A

    2014-11-12

    Recent progress in the field of single-walled carbon nanotubes (SWNTs) significantly enhances the potential for practical use of this remarkable class of material in advanced electronic and sensor devices. One of the most daunting challenges is in creating large-area, perfectly aligned arrays of purely semiconducting SWNTs (s-SWNTs). Here we introduce a simple, scalable, large-area scheme that achieves this goal through microwave irradiation of aligned SWNTs grown on quartz substrates. Microstrip dipole antennas of low work-function metals concentrate the microwaves and selectively couple them into only the metallic SWNTs (m-SWNTs). The result allows for complete removal of all m-SWNTs, as revealed through systematic experimental and computational studies of the process. As one demonstration of the effectiveness, implementing this method on large arrays consisting of ~20,000 SWNTs completely removes all of the m-SWNTs (~7,000) to yield a purity of s-SWNTs that corresponds, quantitatively, to at least to 99.9925% and likely significantly higher.

  20. Upscaling of integrated photoelectrochemical water-splitting devices to large areas.

    PubMed

    Turan, Bugra; Becker, Jan-Philipp; Urbain, Félix; Finger, Friedhelm; Rau, Uwe; Haas, Stefan

    2016-01-01

    Photoelectrochemical water splitting promises both sustainable energy generation and energy storage in the form of hydrogen. However, the realization of this vision requires laboratory experiments to be engineered into a large-scale technology. Up to now only few concepts for scalable devices have been proposed or realized. Here we introduce and realize a concept which, by design, is scalable to large areas and is compatible with multiple thin-film photovoltaic technologies. The scalability is achieved by continuous repetition of a base unit created by laser processing. The concept allows for independent optimization of photovoltaic and electrochemical part. We demonstrate a fully integrated, wireless device with stable and bias-free operation for 40 h. Furthermore, the concept is scaled to a device area of 64 cm(2) comprising 13 base units exhibiting a solar-to-hydrogen efficiency of 3.9%. The concept and its successful realization may be an important contribution towards the large-scale application of artificial photosynthesis. PMID:27601181

  1. Upscaling of integrated photoelectrochemical water-splitting devices to large areas

    NASA Astrophysics Data System (ADS)

    Turan, Bugra; Becker, Jan-Philipp; Urbain, Félix; Finger, Friedhelm; Rau, Uwe; Haas, Stefan

    2016-09-01

    Photoelectrochemical water splitting promises both sustainable energy generation and energy storage in the form of hydrogen. However, the realization of this vision requires laboratory experiments to be engineered into a large-scale technology. Up to now only few concepts for scalable devices have been proposed or realized. Here we introduce and realize a concept which, by design, is scalable to large areas and is compatible with multiple thin-film photovoltaic technologies. The scalability is achieved by continuous repetition of a base unit created by laser processing. The concept allows for independent optimization of photovoltaic and electrochemical part. We demonstrate a fully integrated, wireless device with stable and bias-free operation for 40 h. Furthermore, the concept is scaled to a device area of 64 cm2 comprising 13 base units exhibiting a solar-to-hydrogen efficiency of 3.9%. The concept and its successful realization may be an important contribution towards the large-scale application of artificial photosynthesis.

  2. Large wood budget assessment along a gravel bed river affected by volcanic eruption: the Rio Blanco study case (Chile).

    NASA Astrophysics Data System (ADS)

    Oss-Cazzador, Daniele; Iroume, Andres; Lenzi, Mario; Picco, Lorenzo

    2016-04-01

    Wood in riverine environments exerts different functions on ecological and geomorphic settings, influencing morphological processes, and increasing risks for sensitive structures. Large wood (LW) is defined as wood material, dead or alive, larger than 10 cm in diameter and 1 m in length. Natural hazards can strongly increase the presence of LW in waterways and flood events can transport it affecting the ecosystem and landscape. This study aims to increase the knowledge of wood budget, considering the effects of two subsequent slight flood events along a sub-reach of the Rio Blanco gravel bed river , in Chilean Patagonia, strongly affected by the eruption of Chaiten volcano in 2008. The volcanic eruption affected almost 3,5 km 2 of evergreen forest on the southern (left) bank, because of primary direct effects from pyroclastic density currents and lahar-floods that caused deposition up to 8 m of reworked tephra, alluvium, and wood on floodplains and terrace along the Rio Blanco. After the eruption, there was a considerable increase of LW into the main channel: into the bankfull channel, volume exceeds 100 m 3 /ha. Field surveys were carried out in January and March 2015, before and after two slight flood events (Recurrence Intervals lower than 1 year). The pre-event phase permitted to detect and analyze the presence of LW into the study area, along a 80 m-long reach of Rio Blanco (7500 m 2 . Every LW element was manually measured and described, a numbered metal tag was installed, and the position was recorded by GPS device. In January, there was a total amount of 113 m 3 /ha, 90% accumulated in LW jams (WJ) and 10% as single logs. The LW was characterized by mean dimensions of 3,36 m height, 0,25 m diameter and 0,26 m 3 volume, respectively. The WJ are characterized by wide range of dimension: volume varies from 0,28 m 3 to 672 m 3 , length from 1,20 m to 56 m, width from 0,40 m to 8,70 m and height from 0,20 m to 3 m, respectively. After the flood events, field

  3. Phosphate single mode large mode area all-solid photonic crystal fiber with multi-watt output power

    SciTech Connect

    Wang, Longfei; He, Dongbing; Yu, Chunlei; Hu, Lili; Chen, Danping; Liu, Hui; Qiu, Jianrong

    2014-03-31

    An index-depressed active core, single-mode phosphate all-solid large-mode-area photonic crystal fiber (PCF) is theoretically investigated using full-vectorial finite difference approach and experimentally realized. The PCF has a maximum output power of 5.4 W and 31% slope efficiency. Single-mode operation is realized through PCFs with core diameters of 30, 35, and 40 μm, respectively. The beam quality is not degraded even at maximum output power. Our simulations and experiments reveal that the laser performance is significantly affected by the center-to-center distance between the two nearest rods Λ, the rod diameter d, and their ratio d/Λ, implying that much attention should be given in employing optimal parameters to achieve excellent laser performance.

  4. Large nuclear vacuoles in spermatozoa negatively affect pregnancy rate in IVF cycles

    PubMed Central

    Ghazali, Shahin; Talebi, Ali Reza; Khalili, Mohammad Ali; Aflatoonian, Abbas; Esfandiari, Navid

    2015-01-01

    Background: Recently, motile sperm organelle morphology examination (MSOME) criteria as a new real time tool for evaluation of spermatozoa in intracytoplasmic sperm injection (ICSI) cycles has been considered. Objective: The aim was to investigate the predictive value of MSOME in in vitro fertilization (IVF) in comparison to ICSI cycles and evaluation of the association between MSOME parameters and traditional sperm parameters in both groups. Materials and Methods: This is a cross sectional prospective analysis of MSOME parameters in IVF (n=31) and ICSI cycles (n=35). MSOME parameters were also evaluated as the presence of vacuole (none, small, medium, large or mix); head size (normal, small or large); cytoplasmic droplet; head shape and acrosome normality. In sub-analysis, MSOME parameters were compared between two groups with successful or failed clinical pregnancy in each group. Results: In IVF group, the rate of large nuclear vacuole showed significant increase in failed as compared to successful pregnancies (13.81±9.7vs7.38±4.4, respectively, p=0.045) while MSOME parameters were the same between successful and failed pregnancies in ICSI group. Moreover, a negative correlation was noticed between LNV and sperm shape normalcy. In ICSI group, a negative correlation was established between cytoplasmic droplet and sperm shape normalcy. In addition, there was a positive correlation between sperm shape normalcy and non-vacuolated spermatozoa. Conclusion: The high rate of large nuclear vacuoles in sperm used in IVF cycles with failed pregnancies confirms that MSOME, is a helpful tool for fine sperm morphology assessment, and its application may enhance the assisted reproduction technology success rates. PMID:26494990

  5. GLAST: Exploring Nature's Highest Energy Processes with the Gamma-ray Large Area Space Telescope

    NASA Technical Reports Server (NTRS)

    Digel, Seth; Myers, J. D.; White, Nicholas E. (Technical Monitor)

    2001-01-01

    The Gamma-ray Large Area Space Telescope (GLAST) is an international and multi-agency space mission that will study the cosmos in the energy range 10 keV-300 GeV. Several successful exploratory missions in gamma-ray astronomy led to the Energetic Gamma Ray Experiment Telescope (EGRET) instrument on the Compton Gamma Ray Observatory (CGRO). Launched in 1991, EGRET made the first complete survey of the sky in the 30 MeV-10 GeV range. EGRET showed the high-energy gamma-ray sky to be surprisingly dynamic and diverse, with sources ranging from the sun and moon to massive black holes at large redshifts. Most of the gamma-ray sources detected by EGRET remain unidentified. In light of the discoveries with EGRET, the great potential of the next generation gamma-ray telescope can be appreciated. GLAST will have an imaging gamma-ray telescope vastly more capable than instruments flown previously, as well as a secondary instrument to augment the study of gamma-ray bursts. The main instrument, the Large Area Telescope (LAT), will have superior area, angular resolution, field of view, and deadtime that together will provide a factor of 30 or more advance in sensitivity, as well as provide capability for study of transient phenomena. The GLAST Burst Monitor (GBM) will have a field of view several times larger than the LAT and will provide spectral coverage of gamma-ray bursts that extends from the lower limit of the LAT down to 10 keV. The basic parameters of the GBM are compared to those of the Burst and Transient Source Experiment (BATSE) instrument on CGRO in Table 1-2. With the LAT and GBM, GLAST will be a flexible observatory for investigating the great range of astrophysical phenomena best studied in high-energy gamma rays. NASA plans to launch GLAST in late 2005.

  6. Testing of a Helium Loop Heat Pipe for Large Area Cryocooling

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Robinson, Franklin Lee

    2015-01-01

    Future NASA space telescopes and exploration missions require cryocooling of large areas such as optics, detector arrays, and cryogenic propellant tanks. One device that can potentially be used to provide closed-loop cryocooling is the cryogenic loop heat pipe (CLHP). A CLHP has many advantages over other devices in terms of reduced mass, reduced vibration, high reliability, and long life. A helium CLHP has been tested extensively in a thermal vacuum chamber using a cryocooler as the heat sink to characterize its transient and steady performance and verify its ability to cool large areas or components in the 3K temperature range. A copper plate with attached electrical heters was used to simulate the heat source, and heat was collected by the CLHP evaporator and transferred to the cryocooler for ultimate heat rejection. The helium CLHP thermal performance test included cool-down from the ambient temperature, startup, capillary limit, heat removal capability, rapid power changes, and long duration steady state operation. The helium CLHP demonstrated robust operation under steady state and transient conditions. The loop could be cooled from the ambient temperature to subcritical temperatures very effectively, and could start successfully without pre-conditioning by simply applying power to both the capillary pump and the evaporator plate. It could adapt to rapid changes in the heat load, and reach a new steady state very quickly. Heat removal between 10mW and 140mW was demonstrated, yielding a power turn down ratio of 14. When the CLHP capillary limit was exceeded, the loop could resume its normal function by reducing the power to the capillary pump. Steady state operations up to 17 hours at several heat loads were demonstrated. The ability of the helium CLHP to cool large areas was therefore successfully verified.

  7. Testing of a Helium Loop Heat Pipe for Large Area Cryocooling

    NASA Technical Reports Server (NTRS)

    Ku, Jentung; Robinson, Franklin

    2016-01-01

    Future NASA space telescopes and exploration missions require cryocooling of large areas such as optics, detector arrays, and cryogenic propellant tanks. One device that can potentially be used to provide closed-loop cryocooling is the cryogenic loop heat pipe (CLHP). A CLHP has many advantages over other devices in terms of reduced mass, reduced vibration, high reliability, and long life. A helium CLHP has been tested extensively in a thermal vacuum chamber using a cryocooler as the heat sink to characterize its transient and steady performance and verify its ability to cool large areas or components in the 3K temperature range. A copper plate with attached electrical heaters was used to simulate the heat source, and heat was collected by the CLHP evaporator and transferred to the cryocooler for ultimate heat rejection. The helium CLHP thermal performance test included cool-down from the ambient temperature, startup, capillary limit, heat removal capability, rapid power changes, and long duration steady state operation. The helium CLHP demonstrated robust operation under steady state and transient conditions. The loop could be cooled from the ambient temperature to subcritical temperatures very effectively, and could start successfully without pre-conditioning by simply applying power to both the capillary pump and the evaporator plate. It could adapt to rapid changes in the heat load, and reach a new steady state very quickly. Heat removal between 10mW and 140mW was demonstrated, yielding a power turn down ratio of 14. When the CLHP capillary limit was exceeded, the loop could resume its normal function by reducing the power to the capillary pump. Steady state operations up to 17 hours at several heat loads were demonstrated. The ability of the helium CLHP to cool large areas was therefore successfully verified.

  8. Nanosphere lithography based technique for fabrication of large area well ordered metal particle arrays

    NASA Astrophysics Data System (ADS)

    Barcelo, Steven J.; Lam, Si-Ty; Gibson, Gary A.; Sheng, Xia; Henze, Dick

    2012-03-01

    Nanosphere lithography is an effective technique for high throughput fabrication of well-ordered patterns, but expanding the method to large area coverage of nanoparticles less than 300 nm in diameter while maintaining good order has proven challenging. Here we demonstrate a nanosphere lithography based technique for fabricating large area, wellordered arrays of hemispherical metal particles which pushes the limits of these size constraints. First, large area monolayers of polystyrene (PS) nanospheres are assembled at an air-water interface and then transferred to a submerged substrate. The submerged substrate is supported at a 10° angle so that the water draining speed can be used to control the transfer rate, which is essential for hydrophobic substrates such as the polymer-coated glass used in our work. A double liftoff procedure was used to transfer the PS pattern to a silver particle array on an arbitrary substrate, achieving tunable control over the final metal particle diameter and spacing in the range of 50-150 nm and 100-200 nm, respectively. Additional control over particle shape and diameter can be obtained by modifying the substrate surface energy. For example, depositing silver on ITO-coated glass rather than a more hydrophilic clean glass substrate leads to a more hemispherical particle shape and a diameter reduction of 20%. Peak wavelength-selective reflection greater than 70% and total extinction greater than 90% were measured. The intensity, position and bandwidth of the main plasmon resonance of the arrays were shown to have minimal angle dependence up to at least 30° off normal.

  9. TFT-Based Active Pixel Sensors for Large Area Thermal Neutron Detection

    NASA Astrophysics Data System (ADS)

    Kunnen, George

    Due to diminishing availability of 3He, which is the critical component of neutron detecting proportional counters, large area flexible arrays are being considered as a potential replacement for neutron detection. A large area flexible array, utilizing semiconductors for both charged particle detection and pixel readout, ensures a large detection surface area in a light weight rugged form. Such a neutron detector could be suitable for deployment at ports of entry. The specific approach used in this research, uses a neutron converter layer which captures incident thermal neutrons, and then emits ionizing charged particles. These ionizing particles cause electron-hole pair generation within a single pixel's integrated sensing diode. The resulting charge is then amplified via a low-noise amplifier. This document begins by discussing the current state of the art in neutron detection and the associated challenges. Then, for the purpose of resolving some of these issues, recent design and modeling efforts towards developing an improved neutron detection system are described. Also presented is a low-noise active pixel sensor (APS) design capable of being implemented in low temperature indium gallium zinc oxide (InGaZnO) or amorphous silicon (a-Si:H) thin film transistor process compatible with plastic substrates. The low gain and limited scalability of this design are improved upon by implementing a new multi-stage self-resetting APS. For each APS design, successful radiation measurements are also presented using PiN diodes for charged particle detection. Next, detection array readout methodologies are modeled and analyzed, and use of a matched filter readout circuit is described as well. Finally, this document discusses detection diode integration with the designed TFT-based APSs.

  10. Influence of transbilayer area asymmetry on the morphology of large unilamellar vesicles.

    PubMed Central

    Mui, B L; Döbereiner, H G; Madden, T D; Cullis, P R

    1995-01-01

    The morphological consequences of differences in the monolayer surface areas of large unilamellar vesicles (LUVs) have been examined employing cryoelectron microscopy techniques. Surface area was varied by inducing net transbilayer transport of dioleoylphosphatidylglycerol (DOPG) in dioleoylphosphatidylcholine (DOPC):DOPG (9:1, mol:mol) LUVs in response to transmembrane pH gradients. It is shown that when DOPG is transported from the inner to the outer monolayer, initially invaginated LUVs are transformed to long narrow tubular structures, or spherical structures with one or more protrusions. Tubular structures are also seen in response to outward DOPG transport in DOPC:DOPG:Chol (6:1:3, mol:mol:mol) LUV systems, and when lyso-PC is allowed to partition into the exterior monolayer of DOPC:DOPG (9:1, mol:mol) LUVs in the absence of DOPG transport. Conversely, when the inner monolayer area is expanded by the transport of DOPG from the outer monolayer to the inner monolayer of non-invaginated LUVs, a reversion to invaginated structures is observed. The morphological changes are well described by an elastic bending theory of the bilayer. Identification of the difference in relaxed monolayer areas and of the volume-to-area ratio of the LUVs as the shape-determining factors allows a quantitative classification of the observed morphologies. The morphology seen in LUVs supports the possibility that factors leading to differences in monolayer surface areas could play important roles in intracellular membrane transport processes. Images FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 PMID:8519993

  11. Large-area few-layer MoS2 deposited by sputtering

    NASA Astrophysics Data System (ADS)

    Huang, Jyun-Hong; Chen, Hsing-Hung; Liu, Pang-Shiuan; Lu, Li-Syuan; Wu, Chien-Ting; Chou, Cheng-Tung; Lee, Yao-Jen; Li, Lain-Jong; Chang, Wen-Hao; Hou, Tuo-Hung

    2016-06-01

    Direct magnetron sputtering of transition metal dichalcogenide targets is proposed as a new approach for depositing large-area two-dimensional layered materials. Bilayer to few-layer MoS2 deposited by magnetron sputtering followed by post-deposition annealing shows superior area scalability over 20 cm2 and layer-by-layer controllability. High crystallinity of layered MoS2 was confirmed by Raman, photo-luminescence, and transmission electron microscopy analysis. The sputtering temperature and annealing ambience were found to play an important role in the film quality. The top-gate field-effect transistor by using the layered MoS2 channel shows typical n-type characteristics with a current on/off ratio of approximately 104. The relatively low mobility is attributed to the small grain size of 0.1-1 μm with a trap charge density in grain boundaries of the order of 1013 cm-2.

  12. Laboratory and test beam results from a large-area silicon drift detector

    NASA Astrophysics Data System (ADS)

    Bonvicini, V.; Busso, L.; Giubellino, P.; Gregorio, A.; Idzik, M.; Kolojvari, A.; Montano, L. M.; Nouais, D.; Petta, C.; Rashevsky, A.; Randazzo, N.; Reito, S.; Tosello, F.; Vacchi, A.; Vinogradov, L.; Zampa, N.

    2000-01-01

    A very large-area (6.75×8 cm 2) silicon drift detector with integrated high-voltage divider has been designed, produced and fully characterised in the laboratory by means of ad hoc designed MOS injection electrodes. The detector is of the "butterfly" type, the sensitive area being subdivided into two regions with a maximum drift length of 3.3 cm. The device was also tested in a pion beam (at the CERN PS) tagged by means of a microstrip detector telescope. Bipolar VLSI front-end cells featuring a noise of 250 e - rms at 0 pF with a slope of 40 e -/pF have been used to read out the signals. The detector showed an excellent stability and featured the expected characteristics. Some preliminary results will be presented.

  13. Stitching for a large area of surface topography analysis of diamond grinding wheel

    NASA Astrophysics Data System (ADS)

    Wang, Shuang; Cui, Changcai; Huang, Chunqi; Huang, Hui; Ye, Ruifang; Fu, Shiwei

    2013-01-01

    It is necessary to stitch small area of images together for large surface analysis while the measurement instrument used with a limited measurement area, e.g. White-light Interferometry (WLI)-based system. A new stitching method is proposed in this paper for diamond grinding wheel surface analysis. The images are captured by a WLI-based system and the 3D images' stitching requires an overlapping region of 30%~50%. First, two-step intensity correlation matching method is used to obtain several pairs of matched points fast and the RANSAC (Random Sample Consensus) algorithm is adopted to screen them to get exact pairs of matched points. Then the measurement errors are adjusted and a stitched topography is got after data fusion. Experiments show that this method can effectively stitch 3D images of diamond grinding wheel together in less than 4 minutes with a correlation coefficient above 0.9 for two horizontal overlapping regions after adjustment.

  14. Low-impedance internal linear inductive antenna for large-area flat panel display plasma processing

    SciTech Connect

    Kim, K.N.; Jung, S.J.; Lee, Y.J.; Yeom, G.Y.; Lee, S.H.; Lee, J.K.

    2005-03-15

    An internal-type linear inductive antenna, that is, a double-comb-type antenna, was developed for a large-area plasma source having the size of 1020 mmx830 mm, and high density plasmas on the order of 2.3x10{sup 11} cm{sup -3} were obtained with 15 mTorr Ar at 5000 W of inductive power with good plasma stability. This is higher than that for the conventional serpentine-type antenna, possibly due to the low impedance, resulting in high efficiency of power transfer for the double-comb antenna type. In addition, due to the remarkable reduction of the antenna length, a plasma uniformity of less than 8% was obtained within the substrate area of 880 mmx660 mm at 5000 W without having a standing-wave effect.

  15. Versatile large-mode-area femtosecond laser-written Tm:ZBLAN glass chip lasers.

    PubMed

    Lancaster, D G; Gross, S; Fuerbach, A; Heidepriem, H Ebendorff; Monro, T M; Withford, M J

    2012-12-01

    We report performance characteristics of a thulium doped ZBLAN waveguide laser that supports the largest fundamental modes reported in a rare-earth doped planar waveguide laser (to the best of our knowledge). The high mode quality of waveguides up to 45 um diameter (~1075 μm(2) mode-field area) is validated by a measured beam quality of M(2)~1.1 ± 0.1. Benefits of these large mode-areas are demonstrated by achieving 1.9 kW peak-power output Q-switched pulses. The 1.89 μm free-running cw laser produces 205 mW and achieves a 67% internal slope efficiency corresponding to a quantum efficiency of 161%. The 9 mm long planar chip developed for concept demonstration is rapidly fabricated by single-step optical processing, contains 15 depressed-cladding waveguides, and can operate in semi-monolithic or external cavity laser configurations.

  16. Yb-doped large mode area fibers with depressed clad and dopant confinement

    NASA Astrophysics Data System (ADS)

    Roy, Vincent; Paré, Claude; Laperle, Pierre; Desbiens, Louis; Taillon, Yves

    2016-03-01

    Large mode area fibers with depressed-index cladding layer and confinement of rare-earth dopants can provide effective suppression of high-order modes. A polarization-maintaining Yb-doped double-clad fiber with 35/250 μm core/clad diameter has been fabricated from conventional methods according to this design. The fiber which has an effective mode area close to 500 μm2 yields near diffraction-limited output with beam quality factor M2 close to 1.1 when tested as a power amplifier with a coherent seed light source. Beam pointing measurements provide further evidence for near single-mode behavior as the pointing fluctuations are shown to be negligible once the fiber is coiled to a given diameter.

  17. Large-area, uniform white light LED source on a flexible substrate.

    PubMed

    Sher, Chin-Wei; Chen, Kuo-Ju; Lin, Chien-Chung; Han, Hau-Vei; Lin, Huang-Yu; Tu, Zong-Yi; Tu, Hsien-Hao; Honjo, Keiji; Jiang, Hsin-Yi; Ou, Sin-Liang; Horng, Ray-Hua; Li, Xiuling; Fu, Chien-Chung; Kuo, Hao-Chung

    2015-09-21

    This study demonstrates the flexible white LED structure with high lumen efficiency and uniform optical performance for neutral white and warm white CCT. Flip-chip LEDs were attached on a polyimide substrate with copper strips as electrical and thermal conduction paths. Yellow phosphors are mixed with polydimenthysiloxane (PDMS) to provide mechanical support and flexibility. The light efficiency of this device can reach 120 lm/W and 85% of light output uniformity of the emission area can be achieved. Moreover, the optical simulation is employed to evaluate various designs of this flexible film in order to obtain uniform output. Both the pitch between the individual devices and the thickness of the phosphor film are calculated for optimization purpose. This flexible white LED with high lumen efficiency and good reliability is suitable for the large area fixture in the general lighting applications. PMID:26406747

  18. Large area CMOS bio-pixel array for compact high sensitive multiplex biosensing.

    PubMed

    Sandeau, Laure; Vuillaume, Cassandre; Contié, Sylvain; Grinenval, Eva; Belloni, Federico; Rigneault, Hervé; Owens, Roisin M; Fournet, Margaret Brennan

    2015-02-01

    A novel CMOS bio-pixel array which integrates assay substrate and assay readout is demonstrated for multiplex and multireplicate detection of a triplicate of cytokines with single digit pg ml(-1) sensitivities. Uniquely designed large area bio-pixels enable individual assays to be dedicated to and addressed by single pixels. A capability to simultaneously measure a large number of targets is provided by the 128 available pixels. Chemiluminescent assays are carried out directly on the pixel surface which also detects the emitted chemiluminescent photons, facilitating a highly compact sensor and reader format. The high sensitivity of the bio-pixel array is enabled by the high refractive index of silicon based pixels. This in turn generates a strong supercritical angle luminescence response significantly increasing the efficiency of the photon collection over conventional farfield modalities. PMID:25490928

  19. A large area cosmic muon detector located at Ohya stone mine

    NASA Technical Reports Server (NTRS)

    Nii, N.; Mizutani, K.; Aoki, T.; Kitamura, T.; Mitsui, K.; Matsuno, S.; Muraki, Y.; Ohashi, Y.; Okada, A.; Kamiya, Y.

    1985-01-01

    The chemical composition of the primary cosmic rays between 10 to the 15th power eV and 10 to the 18th power eV were determined by a Large Area Cosmic Muon Detector located at Ohya stone mine. The experimental aims of Ohya project are; (1) search for the ultra high-energy gamma-rays; (2) search for the GUT monopole created by Big Bang; and (3) search for the muon bundle. A large number of muon chambers were installed at the shallow underground near Nikko (approx. 100 Km north of Tokyo, situated at Ohya-town, Utsunomiya-city). At the surface of the mine, very fast 100 channel scintillation counters were equipped in order to measure the direction of air showers. These air shower arrays were operated at the same time, together with the underground muon chamber.

  20. Large-area functionalized CVD graphene for work function matched transparent electrodes

    PubMed Central

    Bointon, Thomas H.; Jones, Gareth F.; De Sanctis, Adolfo; Hill-Pearce, Ruth; Craciun, Monica F.; Russo, Saverio

    2015-01-01

    The efficiency of flexible photovoltaic and organic light emitting devices is heavily dependent on the availability of flexible and transparent conductors with at least a similar workfunction to that of Indium Tin Oxide. Here we present the first study of the work function of large area (up to 9 cm2) FeCl3 intercalated graphene grown by chemical vapour deposition on Nickel, and demonstrate values as large as 5.1 eV. Upon intercalation, a charge density per graphene layer of 5 ⋅ 1013 ± 5 ⋅ 1012 cm−2 is attained, making this material an attractive platform for the study of plasmonic excitations in the infrared wavelength spectrum of interest to the telecommunication industry. Finally, we demonstrate the potential of this material for flexible electronics in a transparent circuit on a polyethylene naphthalate substrate. PMID:26548711

  1. Effects of Large Area Liquid Lithium Limiters on Spherical Torus Plasmas

    SciTech Connect

    R. Kaita; R. Majeski; M. Boaz; P. Efthimion; G. Gettelfinger; T. Gray; D. Hoffman; S. Jardin; H. Kugel; P. Marfuta; T. Munsat; C. Neumeyer; S. Raftopoulos; V. Soukhanovskii; J. Spaleta; G. Taylor; J. Timberlake; R. Woolley; L. Zakharov; M. Finkenthal; D. Stutman; L. Delgado-Aparicio; R.P. Seraydarian; G. Antar; R. Doerner; S. Luckhardt; M. Baldwin; R.W. Conn; R. Maingi; M. Menon; R. Causey; D. Buchenauer; M. Ulrickson; B. Jones; D. Rodgers

    2004-06-07

    Use of a large-area liquid lithium surface as a first wall has significantly improved the plasma performance in the Current Drive Experiment-Upgrade (CDX-U) at the Princeton Plasma Physics Laboratory. Previous CDX-U experiments with a partially-covered toroidal lithium limiter tray have shown a decrease in impurities and the recycling of hydrogenic species. Improvements in loading techniques have permitted nearly full coverage of the tray surface with liquid lithium. Under these conditions, there was a large drop in the loop voltage needed to sustain the plasma current. The data are consistent with simulations that indicate more stable plasmas having broader current profiles, higher temperatures, and lowered impurities with liquid lithium walls. As further evidence for reduced recycling with a liquid lithium limiter, the gas puffing had to be increased by up to a factor of eight for the same plasma density achieved with an empty toroidal tray limiter.

  2. An advanced open-path atmospheric pollution monitor for large areas

    SciTech Connect

    Taylor, L.

    1995-10-01

    Large amounts of toxic waste materials, generated in manufacturing fuel for nuclear reactors, are stored in tanks buried over large areas at DOE sites. Flammable and hazardous gases are continually generated by chemical reactions in the waste materials. To prevent explosive concentrations of these gases, the gases are automatically vented to the atmosphere when the pressure exceeds a preset value. Real-time monitoring of the atmosphere above the tanks with automatic alarming is needed to prevent exposing workers to unsafe conditions when venting occurs. This report describes the development of a monitor which can measure concentrations of hazardous gases over ranges as long as 4km. The system consists of a carbon dioxide laser combined with an acousto-optic tunable filter.

  3. Large area x-ray collimator-the zone plate approach.

    PubMed

    Menz, Benedikt; Braig, Christoph; Bräuninger, Heinrich; Burwitz, Vadim; Hartner, Gisela; Predehl, Peter

    2015-09-10

    One question of particular interest in the measurement of x-ray imaging optics for space telescopes concerns the characteristics of the point spread function (PSF) in orbit and the focal length for an infinite source distance. In order to measure such a PSF, a parallel x-ray beam with a diameter of several centimeters to meters is required. For this purpose a large area transmission x-ray zone plate (ZP) for collimating x-ray beams has been designed, built, and tested. Furthermore we present a setup to determine large-scale aberrations of the collimated beam. From x-ray measurements we obtain an upper limit for the angular resolution of ±0.2 arc sec and a first-order diffraction efficiency of ≈13%. These results show that it is possible to use a ZP as a collimator for the PANTER x-ray test facility. PMID:26368954

  4. Evapotranspiration and runoff from large land areas: Land surface hydrology for atmospheric general circulation models

    NASA Technical Reports Server (NTRS)

    Famiglietti, J. S.; Wood, Eric F.

    1993-01-01

    A land surface hydrology parameterization for use in atmospheric GCM's is presented. The parameterization incorporates subgrid scale variability in topography, soils, soil moisture and precipitation. The framework of the model is the statistical distribution of a topography-soils index, which controls the local water balance fluxes, and is therefore taken to represent the large land area. Spatially variable water balance fluxes are integrated with respect to the topography-soils index to yield our large topography-soils distribution, and interval responses are weighted by the probability of occurrence of the interval. Grid square averaged land surface fluxes result. The model functions independently as a macroscale water balance model. Runoff ratio and evapotranspiration efficiency parameterizations are derived and are shown to depend on the spatial variability of the above mentioned properties and processes, as well as the dynamics of land surface-atmosphere interactions.

  5. Thin film cadmium telluride charged particle sensors for large area neutron detectors

    SciTech Connect

    Murphy, J. W.; Smith, L.; Calkins, J.; Mejia, I.; Cantley, K. D.; Chapman, R. A.; Quevedo-Lopez, M.; Gnade, B.; Kunnen, G. R.; Allee, D. R.; Sastré-Hernández, J.; Contreras-Puente, G.; Mendoza-Pérez, R.

    2014-09-15

    Thin film semiconductor neutron detectors are an attractive candidate to replace {sup 3}He neutron detectors, due to the possibility of low cost manufacturing and the potential for large areas. Polycrystalline CdTe is found to be an excellent material for thin film charged particle detectors—an integral component of a thin film neutron detector. The devices presented here are characterized in terms of their response to alpha and gamma radiation. Individual alpha particles are detected with an intrinsic efficiency of >80%, while the devices are largely insensitive to gamma rays, which is desirable so that the detector does not give false positive counts from gamma rays. The capacitance-voltage behavior of the devices is studied and correlated to the response due to alpha radiation. When coupled with a boron-based neutron converting material, the CdTe detectors are capable of detecting thermal neutrons.

  6. The large-area hybrid-optics CLAS12 RICH detector: Tests of innovative components

    SciTech Connect

    Contalbrigo, M; Baltzell, N; Benmokhtar, F; Barion, L; Cisbani, E; El Alaoui, A; Hafidi, K; Hoek, M; Kubarovsky, V; Lagamba, L; Lucherini, V; Malaguti, R; Mirazita, M; Montgomery, R; Movsisyan, A; Musico, P; Orecchini, D; Orlandi, A; Pappalardo, L L; Pereira, S; Perrino, R; Phillips, J; Pisano, S; Rossi, P; Squerzanti, S; Tomassini, S; Turisini, M; Viticchiè, A

    2014-07-01

    A large area ring-imaging Cherenkov detector has been designed to provide clean hadron identification capability in the momentum range from 3 GeV/c to 8 GeV/c for the CLAS12 experiments at the upgraded 12 GeV continuous electron beam accelerator facility of Jefferson Lab to study the 3D nucleon structure in the yet poorly explored valence region by deep-inelastic scattering, and to perform precision measurements in hadronization and hadron spectroscopy. The adopted solution foresees a novel hybrid optics design based on an aerogel radiator, composite mirrors and densely packed and highly segmented photon detectors. Cherenkov light will either be imaged directly (forward tracks) or after two mirror reflections (large angle tracks). The preliminary results of individual detector component tests and of the prototype performance at test-beams are reported here.

  7. Replication fidelity assessment of large area sub-μm structured polymer surfaces using scatterometry

    NASA Astrophysics Data System (ADS)

    Calaon, M.; Madsen, M. H.; Weirich, J.; Hansen, H. N.; Tosello, G.; Hansen, P. E.; Garnaes, J.; Tang, P. T.

    2015-12-01

    The present study addresses one of the key challenges in the product quality control of transparent structured polymer substrates, the replication fidelity of sub-μm structures over a large area. Additionally the work contributes to the development of new techniques focused on in-line characterization of large nanostructured surfaces using scatterometry. In particular an approach to quantify the replication fidelity of high volume manufacturing processes such as polymer injection moulding is presented. Both periodic channels and semi-spherical structures were fabricated on nickel shims used for later injection moulding of Cyclic-olefin-copolymer (COC) substrate were the sub-μm features where ultimately transferred. The scatterometry system was validated using calibrated atomic force microscopy measurements and a model based on scalar diffraction theory employed to calculate the expected angular distribution of the reflected and the transmitted intensity for the nickel surfaces and structured COC and, respectively.

  8. Infrared radiometric technique for rapid quantitative evaluation of heat flux distribution over large areas

    NASA Astrophysics Data System (ADS)

    Glazer, Stuart; Siebes, Georg

    1989-03-01

    This paper describes a novel approach for rapid, quantitative measurement of spatially distributed heat flux incident on a plane. The technique utilizes the spatial temperature distribution on an opaque thin film at the location of interest, as measured by an imaging infrared radiometer. Knowledge of film radiative properties, plus quantitative estimates of convection cooling permit the steady state energy balance at any location on the film sheet to be solved for the incident heat flux. Absolute accuracies on the order of 10-15 percent have been obtained in tests performed in air. The method is particularly useful for evaluation of spatial heat flux uniformity from distributed heat sources over large areas. It has recently been used in several applications at the Jet Propulsion Laboratory, including flux uniformity measurements from large distributed quartz lamp arrays used during thermal vacuum testing of several spacecraft components, and flux mapping of a low power NdYg laser beam.

  9. Strict dual-mode large-mode-area fiber with multicore structure

    NASA Astrophysics Data System (ADS)

    Jin, Wenxing; Ren, Guobin; Jian, Wei; Jiang, Youchao; Wu, Yue; Yang, Yuguang; Shen, Ya; Jian, Shuisheng

    2016-05-01

    In this paper, we proposed a new kind of quasi-37-cores fiber structure consisting of 15 conventional cores and 22 air-hole cores. Strict dual-mode condition is systematically analyzed about three structure parameters, core-to-core pitch, relative core diameter, and difference of refractive index between core and cladding. Large effective area about 1910.98 μm2 with low bending loss less than 10-3 dB / m is achieved while keeping strict dual-mode. This structured fiber has a great potential in high power fiber lasers and amplifiers.

  10. Final Scientific/Technical Report Development of Large-Area Photo-Detectors

    SciTech Connect

    Frisch, Henry J.

    2013-07-15

    This proposal requested ADR funds for two years to make measurements and detector proto-types in the context of planning a program in conjunction with Argonne National Laboratory to develop very large-area planar photodetectors. The proposed detectors have integrated transmission-line readout and sampling electronics able to achieve timing and position resolutions in the range of 1-50 psec and 1-10 mm, respectively. The capability for very precise time measurements is inherent in the design, and provides a third coordinate, orthogonal to the two in the plane, for the point of origin of photons or charged particles, allowing tomographic reconstruction in 3-dimensions inside a volume.

  11. Design and Characteristics of the Anticoincidence Detector for the GLAST Large Area Telescope

    NASA Technical Reports Server (NTRS)

    Moiseev, A. A.; Hartman, R. C.; Johnson, T. E.; Ormes, J. F.; Thompson, D. J.

    2005-01-01

    The Anti-Coincidence Detector (ACD) is the outermost detector layer in the GLAST Large Area Telescope (LAT), surrounding the top and sides of the tracker. The purpose of the ACD is to detect and veto incident cosmic ray charged particles, which outnumber cosmic gamma rays by 3-4 orders of magnitude. The challenge in ACD design is that it must have high (0.9997) detection efficiency for singly charged relativistic particles, but must also have low sensitivity to backsplash particles. These are products of high- energy interactions in the LAT calorimeter. They can cause a veto signal in the ACD, resulting in loss of good gamma-ray events.

  12. Approaching total absorption at near infrared in a large area monolayer graphene by critical coupling

    SciTech Connect

    Liu, Yonghao; Chadha, Arvinder; Zhao, Deyin; Shuai, Yichen; Menon, Laxmy; Yang, Hongjun; Zhou, Weidong; Piper, Jessica R.; Fan, Shanhui; Jia, Yichen; Xia, Fengnian; Ma, Zhenqiang

    2014-11-03

    We demonstrate experimentally close to total absorption in monolayer graphene based on critical coupling with guided resonances in transfer printed photonic crystal Fano resonance filters at near infrared. Measured peak absorptions of 35% and 85% were obtained from cavity coupled monolayer graphene for the structures without and with back reflectors, respectively. These measured values agree very well with the theoretical values predicted with the coupled mode theory based critical coupling design. Such strong light-matter interactions can lead to extremely compact and high performance photonic devices based on large area monolayer graphene and other two–dimensional materials.

  13. 1550 nm ErAs:In(Al)GaAs large area photoconductive emitters

    NASA Astrophysics Data System (ADS)

    Preu, S.; Mittendorff, M.; Lu, H.; Weber, H. B.; Winnerl, S.; Gossard, A. C.

    2012-09-01

    We report on high power terahertz (THz) emission from ErAs-enhanced In0.52Al0.48As-In0.53Ga0.47As superlattices for operation at 1550 nm. ErAs clusters act as efficient recombination centers. The optical power is distributed among a large, microstructured area in order to reduce the local optical intensity. A THz field strength of 0.7 V/cm (1 V/cm peak-to-peak) at 100 mW average optical power has been obtained, with emission up to about 4 THz in air, limited by the detection crystal used in the system.

  14. A versatile fluorescence lifetime imaging system for scanning large areas with high time and spatial resolution

    NASA Astrophysics Data System (ADS)

    Bernardo, César; Belsley, Michael; de Matos Gomes, Etelvina; Gonçalves, Hugo; Isakov, Dmitry; Liebold, Falk; Pereira, Eduardo; Pires, Vladimiro; Samantilleke, Anura; Vasilevskiy, Mikhail; Schellenberg, Peter

    2014-08-01

    We present a flexible fluorescence lifetime imaging device which can be employed to scan large sample areas with a spatial resolution adjustable from many micrometers down to sub-micrometers and a temporal resolution of 20 picoseconds. Several different applications of the system will be presented including protein microarrays analysis, the scanning of historical samples, evaluation of solar cell surfaces and nanocrystalline organic crystals embedded in electrospun polymeric nanofibers. Energy transfer processes within semiconductor quantum dot superstructures as well as between dye probes and graphene layers were also investigated.

  15. Microfabrication of large-area circular high-stress silicon nitride membranes for optomechanical applications

    NASA Astrophysics Data System (ADS)

    Serra, E.; Bawaj, M.; Borrielli, A.; Di Giuseppe, G.; Forte, S.; Kralj, N.; Malossi, N.; Marconi, L.; Marin, F.; Marino, F.; Morana, B.; Natali, R.; Pandraud, G.; Pontin, A.; Prodi, G. A.; Rossi, M.; Sarro, P. M.; Vitali, D.; Bonaldi, M.

    2016-06-01

    In view of the integration of membrane resonators with more complex MEMS structures, we developed a general fabrication procedure for circular shape SiNx membranes using Deep Reactive Ion Etching (DRIE). Large area and high-stress SiNx membranes were fabricated and used as optomechanical resonators in a Michelson interferometer, where Q values up to 1.3 × 106 were measured at cryogenic temperatures, and in a Fabry-Pérot cavity, where an optical finesse up to 50000 has been observed.

  16. Indirect searches for dark matter with the Fermi large area telescope

    DOE PAGES

    Albert, Andrea

    2015-03-24

    There is overwhelming evidence that non-baryonic dark matter constitutes ~ 27% of the energy density of the Universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce γ rays via annihilation or decay detectable by the Fermi Large Area Telescope (LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. We present recent results from the two cleanest indirect WIMP searches by the Fermi-LAT Collaboration: searches for γ-ray spectral lines and γ-ray emission associated with Milky Way dwarf spheroidal satellite galaxies.

  17. Beta Cage: A New, Large-Area Multi-Wire Screening Detector For Surface Beta Contamination

    SciTech Connect

    Shutt, T.; Schnee, R.W.; Dahl, C.E.; Viveiros, L. de; Gaitskell, R.J.

    2005-09-08

    We report on a design study for a new, dedicated, low-radioactive-background screening detector for low-energy beta-emitting contamination on surfaces. The detector, a large-area gaseous detector with multi-wire proportional readout, has sufficient sensitivity to screen materials at the level needed for the proposed SuperCDMS 1 ton dark matter experiment. Such capability does not currently exist. This detector would have additional applications in low-radioactive-background physics experiments, and radioactive trace analysis, such as 14C dating.

  18. Large area low cost processing for CIS photovoltaics. Final technical report

    SciTech Connect

    B. Basol; G. Norsworthy; C. Leidholm; A. Halani; R. Roe; V. Kapur

    1999-07-22

    An ink coating method was developed for CIS absorber deposition. The technique involves four processing steps: (1) preparation of a Cu-In alloy powder, (2) preparation of an ink using this powder, (3) deposition of the ink on a substrate in the form of a precursor layer, and (4) selenization to convert the Cu-In precursor into a fused CIS film. Absorbers grown by this low-cost, large-area method were used in the fabrication of 10.5% efficient solar cells.

  19. Characterization of large area PMTs at cryogenic temperature for rare event physics experiments

    NASA Astrophysics Data System (ADS)

    Agnes, P.; Raselli, G. L.; Rossella, M.

    2014-03-01

    We carried out a careful evaluation of the behaviour of the large cathode area Hamamatsu R5912-MOD and R5912-2-MOD photomultiplier tubes operating at cryogenic temperature. The measurements were focused on evaluating the parameters which mainly characterize the operating performances of the devices down to 77K. The results that we obtained demonstrate that both photomultipliers models are suited, with some distinguishing characteristics, for light detection in such unconventional operating conditions, certifying the devices for the direct measurement of scintillation light coming from noble-gas liquids in detectors dedicated to neutrino physics and Dark Matter research.

  20. The Fermi Large Area Telescope: Highlights from the first year on orbit

    SciTech Connect

    Raino, S.

    2010-03-26

    Since its launch from Cape Canaveral on June 11, 2008, the Large Area Telescope (LAT) onboard the Fermi Gamma-ray Space Telescope has been performing a survey of the high-energy astrophysical phenomena, including pulsars, black holes and active galactic nuclei; gamma-ray bursts; the origin of cosmic rays and supernova remnants and searches for new phenomena such as supersymmetric dark-matter annihilation. In this contribution I report on the performance of the LAT and on the highlight results achieved in its first year of observations.

  1. Large scale synthesis of nanoporous BN flake with high surface areas

    NASA Astrophysics Data System (ADS)

    Zhu, Hui-Ling; Han, Qiu-Xia; Wu, Jie; Meng, Xiang-Lin; Cui, Hong-Zhi

    2016-01-01

    Nanoporous boron nitride (BN) flake was synthesized in large scale at temperatures between 550 and 600 °C for 10 h via the simple reaction between NaBH4 and CH5N3S. X-ray diffraction and Fourier transform infrared spectra confirm the formation of hexagonal BN. Examination by high-resolution transmission electron microscope reveals that the product is comprised of nanoporous flake, which exhibits a high surface area of 214 m2 g-1 characterized by nitrogen adsorption-desorption isotherms. The nanoporous BN flake has good thermal stability and oxidation resistance up to 800 °C measured by thermogravimetric analysis.

  2. Detection of localized hot electrons in low-pressure large-area microwave discharges

    NASA Astrophysics Data System (ADS)

    Terebessy, Tibor; Kando, Masashi; Kudela, Jozef

    2000-10-01

    A localized hot-electron region was observed in low-pressure (<3 mTorr) large-area microwave discharges. The region appears in the vicinity of the waveguiding plasma-dielectric interface in the place of critical plasma density. The existence of localized hot electrons is explained on the basis of transit time heating in the resonantly enhanced electric field. The phenomenon provides experimental evidence that the plasma resonance region plays an active role in heating mechanism in low-pressure microwave discharges.

  3. Fabricating large-area metallic woodpile photonic crystals using stacking and rolling.

    PubMed

    Ibbotson, Lindsey A; Baumberg, Jeremy J

    2013-08-01

    Stacking thin polymer films supporting metal nanowire gratings provides a simple route, demonstrated here, to producing large-area metallic woodpile structures with high throughput. Under appropriate conditions the grating films can spontaneously roll up, giving a rapid and controllable method of creating multilayers. The resulting three-dimensional (3D) wire structures are flexible and potentially stretchable. Since this process can be extended to include a wide variety of functional materials, it opens up the manufacture of many tailored 3D optical metamaterials.

  4. Development of a large-area silicon α-particle detector.

    PubMed

    Tran, Linh T; Prokopovich, Dale A; Lerch, Michael L F; Petasecca, Marco; Siegele, Rainer; Reinhard, Mark I; Perevertaylo, Vladimir; Rosenfeld, Anatoly B

    2014-09-01

    Circular ion-implanted silicon detector of α-particles with a large, 5-cm(2), sensitive area has been developed. An advantage of the detector is that the detector surface is easily cleanable with chemicals. The hardened surface of the detector shows no signs of deterioration of the spectroscopic and electrical characteristics upon repeated cleaning. The energy resolution along the diameters of the detector was (1.0±0.1)% for the 5.486-MeV α-particles. Detailed tests of the charge collection efficiency and uniformity of the detector entrance window were also performed with a 5.5-MeV He(2+) microbeam.

  5. Large-area graphene films by simple solution casting of edge-selectively functionalized graphite.

    PubMed

    Bae, Seo-Yoon; Jeon, In-Yup; Yang, Jieun; Park, Noejung; Shin, Hyeon Suk; Park, Sungjin; Ruoff, Rodney S; Dai, Liming; Baek, Jong-Beom

    2011-06-28

    We report edge-selective functionalization of graphite (EFG) for the production of large-area uniform graphene films by simply solution-casting EFG dispersions in dichloromethane on silicon oxide substrates, followed by annealing. The resultant graphene films show ambipolar transport properties with sheet resistances of 0.52-3.11 kΩ/sq at 63-90% optical transmittance. EFG allows solution processing methods for the scalable production of electrically conductive, optically transparent, and mechanically robust flexible graphene films for use in practice.

  6. Large area TES spiderweb bolometer for multi-mode cavity microwave detect

    NASA Astrophysics Data System (ADS)

    Biasotti, M.; Bagliani, D.; Ceriale, V.; Corsini, D.; De Bernardis, P.; Gatti, F.; Gualtieri, R.; Lamagna, L.; Masi, S.; Pizzigoni, G.; Schillaci, A.

    2014-07-01

    Large area spiderweb bolometers of 8 mm diameter and a mesh size of 250 μm are fabricated in order to couple with approximately the first 20 modes of a multimode EM cavity at about 140 GHz. The sensor is a Ti/Au/Ti 3 layer TES with Tc tuned in the 330-380 mK and 2 mK transition width. We describe the detector design and the fabrication process, early TES electro-thermal measurements. We also report optical coupling measurement and show the multimode coupling.

  7. The Silicon Tracker Readout Electronics of the Gamma-ray Large Area Space Telescope

    SciTech Connect

    Baldini, Luca; Brez, Alessandro; Himel, Thomas; Hirayama, Masaharu; Johnson, R.P.; Kroeger, Wilko; Latronico, Luca; Minuti, Massimo; Nelson, David; Rando, Riccardo; Sadrozinski, H.F.-W.; Sgro, Carmelo; Spandre, Gloria; Spencer, E.N.; Sugizaki, Mutsumi; Tajima, Hiro; Cohen-Tanugi, Johann; Ziegler, Marcus; /Pisa U. /INFN, Pisa /SLAC /Maryland U. /UC, Santa Cruz /Padua U. /INFN, Padua

    2006-02-27

    A unique electronics system has been built and tested for reading signals from the silicon-strip detectors of the Gamma-ray Large Area Space Telescope mission. The system amplifies and processes signals from 884,736 36-cm strips using only 160 W of power, and it achieves close to 100% detection efficiency with noise occupancy sufficiently low to allow it to self trigger. The design of the readout system is described, and results are presented from ground-based testing of the completed detector system.

  8. Large-mode-area Yb3+-doped photonic crystal fiber laser

    NASA Astrophysics Data System (ADS)

    Yan, Pei-Guang; Zhang, Wei; Li, Yi-Gang; Zhu, Jianping; Ding, Lei; Chen, Sheng-Ping; Lu, Kecheng; Dong, Susan

    2005-01-01

    In this paper a large mode area Yb3+-doped double cladding photonic crystal fiber laser is reported. The laser's output power reaches as high as 4.3W. The slope efficiency and the maximum optical-to-optical efficiency of laser output are 69.4% and 59.7%, respectively, with respect to absorbed pump power. Single transverse mode operation is obtained at central wavelength of 1072.3nm and the measured mode distribution agrees with the simulation by using scalar beam propagation method.

  9. Long life electrodes for large-area x-ray generators

    NASA Technical Reports Server (NTRS)

    Rothe, Dietmar E. (Inventor)

    1991-01-01

    This invention is directed to rugged, reliable, and long-life electrodes for use in large-area, high-current-density electron gun and x-ray generators which are employed as contamination-free preionizers for high-energy pulsed gas lasers. The electron source at the cathode is a corona plasma formed at the interface between a conductor, or semiconductor, and a high-permittivity dielectric. Detailed descriptions are provided of a reliable cold plasma cathode, as well as an efficient liquid-cooled electron beam target (anode) and x-ray generator which concentrates the x-ray flux in the direction of an x-ray window.

  10. Indirect searches for dark matter with the Fermi large area telescope

    SciTech Connect

    Albert, Andrea

    2015-03-24

    There is overwhelming evidence that non-baryonic dark matter constitutes ~ 27% of the energy density of the Universe. Weakly Interacting Massive Particles (WIMPs) are promising dark matter candidates that may produce γ rays via annihilation or decay detectable by the Fermi Large Area Telescope (LAT). A detection of WIMPs would also indicate the existence of physics beyond the Standard Model. We present recent results from the two cleanest indirect WIMP searches by the Fermi-LAT Collaboration: searches for γ-ray spectral lines and γ-ray emission associated with Milky Way dwarf spheroidal satellite galaxies.

  11. Status of GLAST, the Gamma-ray Large-area Space Telescope

    SciTech Connect

    Rochester, L.; /SLAC

    2005-12-14

    GLAST is a satellite-based observatory consisting of the Large-Area Telescope (LAT), a modular 4 x 4-tower pair-conversion telescope with a field-of-view greater than 2 steradians, capable of measuring gamma-ray energies in the range 20 MeV to 300 GeV, and the GLAST Burst Monitor (GBM), a set of NaI and BGO detectors covering 8 steradians and sensitive to photons with energies between 10 keV and 25 MeV, allowing for correlative observations of transient events. The observatory is currently being constructed and is scheduled to be launched in August 2007.

  12. Observation and analysis of high-speed human motion with frequent occlusion in a large area

    NASA Astrophysics Data System (ADS)

    Wang, Yuru; Liu, Jiafeng; Liu, Guojun; Tang, Xianglong; Liu, Peng

    2009-12-01

    The use of computer vision technology in collecting and analyzing statistics during sports matches or training sessions is expected to provide valuable information for tactics improvement. However, the measurements published in the literature so far are either unreliably documented to be used in training planning due to their limitations or unsuitable for studying high-speed motion in large area with frequent occlusions. A sports annotation system is introduced in this paper for tracking high-speed non-rigid human motion over a large playing area with the aid of motion camera, taking short track speed skating competitions as an example. The proposed system is composed of two sub-systems: precise camera motion compensation and accurate motion acquisition. In the video registration step, a distinctive invariant point feature detector (probability density grads detector) and a global parallax based matching points filter are used, to provide reliable and robust matching across a large range of affine distortion and illumination change. In the motion acquisition step, a two regions' relationship constrained joint color model and Markov chain Monte Carlo based joint particle filter are emphasized, by dividing the human body into two relative key regions. Several field tests are performed to assess measurement errors, including comparison to popular algorithms. With the help of the system presented, the system obtains position data on a 30 m × 60 m large rink with root-mean-square error better than 0.3975 m, velocity and acceleration data with absolute error better than 1.2579 m s-1 and 0.1494 m s-2, respectively.

  13. Footprints of triggering in large area surveys of the nearby ISM and YSOs

    NASA Astrophysics Data System (ADS)

    Tóth, L. Viktor; Kiss, Zoltán T.

    Introduction: Our goal is to evaluate the role of trigger effects on the star formation and early stellar evolution by presenting statistically large sample of cloud and low-mass YSO data. Methods: We conducted large area surveys (ranging from 400square-degree to10800square-degree) in optical, NIR and FIR. The distribution of the ISM and low-mass YSOs were surveyed. Results: (1) We pointed out that according to the IRAS FIR data, the structure of the cold ISM is Swiss-cheese-like and compiled an all-sky catalogue of FIR loops (Kiss, Moór Tóth, 2004, A&A 418, 131, and Könyves et al. 2006 A&A submitted). (2) We identified more than 200 interstellar clouds in the Cepheus region, described their morphology and derived their FIR properties (Kiss, Tóth, Krause et al. 2006 A&A in press). (3) We analysed the distribution of classical TTauri candidate objects on very large areas finding galactic large scale distribution, clustering and local inhomogenities by a statistical investigation. Discussion: (1) A relative excess was found statistically in the number of clouds in the direction of the FIR loop shells indicating a possible excess formation. This is a complementary data set to eg. HI all-sky surveys. (2) We demonstrated the differences between the cloud and star formation activity in unperturbed and loop shell regions of the Upper Cepheus region showing possible trigger effects (Kiss, Tóth, Krause et al. 2006 A&A in press). (3) The obtained distribution of low-mass YSOs may be used in comparison with theoretical models and numerical simulations, as well as predictions for further surveys.

  14. Exome Sequencing of 75 Individuals from Multiply Affected Coeliac Families and Large Scale Resequencing Follow Up

    PubMed Central

    Mistry, Vanisha; Bockett, Nicholas A.; Levine, Adam P.; Mirza, Muddassar M.; Hunt, Karen A.; Ciclitira, Paul J.; Hummerich, Holger; Neuhausen, Susan L.; Simpson, Michael A.; Plagnol, Vincent; van Heel, David A.

    2015-01-01

    Coeliac disease (CeD) is a highly heritable common autoimmune disease involving chronic small intestinal inflammation in response to dietary wheat. The human leukocyte antigen (HLA) region, and 40 newer regions identified by genome wide association studies (GWAS) and dense fine mapping, account for ∼40% of the disease heritability. We hypothesized that in pedigrees with multiple individuals with CeD rare [minor allele frequency (MAF) <0.5%] mutations of larger effect size (odds ratios of ∼ 2–5) might exist. We sequenced the exomes of 75 coeliac individuals of European ancestry from 55 multiply affected families. We selected interesting variants and genes for further follow up using a combination of: an assessment of shared variants between related subjects, a model-free linkage test, and gene burden tests for multiple, potentially causal, variants. We next performed highly multiplexed amplicon resequencing of all RefSeq exons from 24 candidate genes selected on the basis of the exome sequencing data in 2,248 unrelated coeliac cases and 2,230 controls. 1,335 variants with a 99.9% genotyping call rate were observed in 4,478 samples, of which 939 were present in coding regions of 24 genes (Ti/Tv 2.99). 91.7% of coding variants were rare (MAF <0.5%) and 60% were novel. Gene burden tests performed on rare functional variants identified no significant associations (p<1×10−3) in the resequenced candidate genes. Our strategy of sequencing multiply affected families with deep follow up of candidate genes has not identified any new CeD risk mutations. PMID:25635822

  15. An Examination of Parameters Affecting Large Eddy Simulations of Flow Past a Square Cylinder

    NASA Technical Reports Server (NTRS)

    Mankbadi, M. R.; Georgiadis, N. J.

    2014-01-01

    Separated flow over a bluff body is analyzed via large eddy simulations. The turbulent flow around a square cylinder features a variety of complex flow phenomena such as highly unsteady vortical structures, reverse flow in the near wall region, and wake turbulence. The formation of spanwise vortices is often times artificially suppressed in computations by either insufficient depth or a coarse spanwise resolution. As the resolution is refined and the domain extended, the artificial turbulent energy exchange between spanwise and streamwise turbulence is eliminated within the wake region. A parametric study is performed highlighting the effects of spanwise vortices where the spanwise computational domain's resolution and depth are varied. For Re=22,000, the mean and turbulent statistics computed from the numerical large eddy simulations (NLES) are in good agreement with experimental data. Von-Karman shedding is observed in the wake of the cylinder. Mesh independence is illustrated by comparing a mesh resolution of 2 million to 16 million. Sensitivities to time stepping were minimized and sampling frequency sensitivities were nonpresent. While increasing the spanwise depth and resolution can be costly, this practice was found to be necessary to eliminating the artificial turbulent energy exchange.

  16. [Carbon source metabolic diversity of soil microbial community under different climate types in the area affected by Wenchuan earthquake].

    PubMed

    Zhang, Guang-Shuai; Lin, Yong-Ming; Ma, Rui-Feng; Deng, Hao-Jun; Du, Kun; Wu, Cheng-Zhen; Hong, Wei

    2015-02-01

    The MS8.0 Wenchuan earthquake in 2008 led to huge damage to land covers in northwest Sichuan, one of the critical fragile eco-regions in China which can be divided into Semi-arid dry hot climate zone (SDHC) and Subtropical humid monsoon climate zone (SHMC). Using the method of Bilog-ECO-microplate technique, this paper aimed to determine the functional diversity of soil microbial community in the earthquake-affected areas which can be divided into undamaged area (U), recover area (R) and damaged area without recovery (D) under different climate types, in order to provide scientific basis for ecological recovery. The results indicated that the average-well-color-development (AWCD) in undamaged area and recovery area showed SDHC > SHMC, which was contrary to the AWCD in the damaged area without recovery. The AWCD of damaged area without recovery was the lowest in both climate zones. The number of carbon source utilization types of soil microbial in SHMC zone was significantly higher than that in SDHC zone. The carbon source utilization types in both climate zones presented a trend of recover area > undamaged area > damaged area without recovery. The carbon source metabolic diversity characteristic of soil microbial community was significantly different in different climate zones. The diversity index and evenness index both showed a ranking of undamaged area > recover area > damaged area without recovery. In addition, the recovery area had the highest richness index. The soil microbial carbon sources metabolism characteristic was affected by soil nutrient, aboveground vegetation biomass and vegetation coverage to some extent. In conclusion, earthquake and its secondary disasters influenced the carbon source metabolic diversity characteristic of soil microbial community mainly through the change of aboveground vegetation and soil environmental factors.

  17. Can interface features affect aggression resulting from violent video game play? An examination of realistic controller and large screen size.

    PubMed

    Kim, Ki Joon; Sundar, S Shyam

    2013-05-01

    Aggressiveness attributed to violent video game play is typically studied as a function of the content features of the game. However, can interface features of the game also affect aggression? Guided by the General Aggression Model (GAM), we examine the controller type (gun replica vs. mouse) and screen size (large vs. small) as key technological aspects that may affect the state aggression of gamers, with spatial presence and arousal as potential mediators. Results from a between-subjects experiment showed that a realistic controller and a large screen display induced greater aggression, presence, and arousal than a conventional mouse and a small screen display, respectively, and confirmed that trait aggression was a significant predictor of gamers' state aggression. Contrary to GAM, however, arousal showed no effects on aggression; instead, presence emerged as a significant mediator.

  18. Can interface features affect aggression resulting from violent video game play? An examination of realistic controller and large screen size.

    PubMed

    Kim, Ki Joon; Sundar, S Shyam

    2013-05-01

    Aggressiveness attributed to violent video game play is typically studied as a function of the content features of the game. However, can interface features of the game also affect aggression? Guided by the General Aggression Model (GAM), we examine the controller type (gun replica vs. mouse) and screen size (large vs. small) as key technological aspects that may affect the state aggression of gamers, with spatial presence and arousal as potential mediators. Results from a between-subjects experiment showed that a realistic controller and a large screen display induced greater aggression, presence, and arousal than a conventional mouse and a small screen display, respectively, and confirmed that trait aggression was a significant predictor of gamers' state aggression. Contrary to GAM, however, arousal showed no effects on aggression; instead, presence emerged as a significant mediator. PMID:23505967

  19. Gamma Ray Large Area Space Telescope (GLAST) Balloon Flight Engineering Model: Overview

    NASA Technical Reports Server (NTRS)

    Thompson, D. J.; Godfrey, G.; Williams, S. M.; Grove, J. E.; Mizuno, T.; Sadrozinski, H. F.-W.; Kamae, T.; Ampe, J.; Briber, Stuart; Dann, James; White, Nicholas E. (Technical Monitor)

    2001-01-01

    The Gamma Ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) is a pair-production high-energy (greater than 20 MeV) gamma-ray telescope being built by an international partnership of astrophysicists and particle physicists for a satellite launch in 2006, designed to study a wide variety of high-energy astrophysical phenomena. As part of the development effort, the collaboration has built a Balloon Flight Engineering Model (BFEM) for flight on a high-altitude scientific balloon. The BFEM is approximately the size of one of the 16 GLAST-LAT towers and contains all the components of the full instrument: plastic scintillator anticoincidence system (ACD), high-Z foil/Si strip pair-conversion tracker (TKR), CsI hodoscopic calorimeter (CAL), triggering and data acquisition electronics (DAQ), commanding system, power distribution, telemetry, real-time data display, and ground data processing system. The principal goal of the balloon flight was to demonstrate the performance of this instrument configuration under conditions similar to those expected in orbit. Results from a balloon flight from Palestine, Texas, on August 4, 2001, show that the BFEM successfully obtained gamma-ray data in this high-background environment.

  20. Electrically tunable terahertz metamaterials with embedded large-area transparent thin-film transistor arrays

    PubMed Central

    Xu, Wei-Zong; Ren, Fang-Fang; Ye, Jiandong; Lu, Hai; Liang, Lanju; Huang, Xiaoming; Liu, Mingkai; Shadrivov, Ilya V.; Powell, David A.; Yu, Guang; Jin, Biaobing; Zhang, Rong; Zheng, Youdou; Tan, Hark Hoe; Jagadish, Chennupati

    2016-01-01

    Engineering metamaterials with tunable resonances are of great importance for improving the functionality and flexibility of terahertz (THz) systems. An ongoing challenge in THz science and technology is to create large-area active metamaterials as building blocks to enable efficient and precise control of THz signals. Here, an active metamaterial device based on enhancement-mode transparent amorphous oxide thin-film transistor arrays for THz modulation is demonstrated. Analytical modelling based on full-wave techniques and multipole theory exhibits excellent consistent with the experimental observations and reveals that the intrinsic resonance mode at 0.75 THz is dominated by an electric response. The resonant behavior can be effectively tuned by controlling the channel conductivity through an external bias. Such metal/oxide thin-film transistor based controllable metamaterials are energy saving, low cost, large area and ready for mass-production, which are expected to be widely used in future THz imaging, sensing, communications and other applications. PMID:27000419