WorldWideScience

Sample records for band quasi-simultaneous observations

  1. Quasi-simultaneous ultraviolet, optical, and infrared observations of the BL Lacertae object PKS 0048-09

    International Nuclear Information System (INIS)

    Falomo, R.; Bouchet, P.; Maraschi, L.; Treves, A.; Tanzi, E.G.

    1988-01-01

    This paper reports on quasi-simultaneous UV, optical, and IR observations of the BL Lac object PKS 0048-09, carried out on January 7-9, 1987, when the object was in a moderately high optical state. The data were used to derive a detailed energy distribution from about 10 to the 14th to about 2.5 x 10 to the 15th Hz. A comparison of observations obtained on January 7-9, 1987, with observations on September 12, 1986, pertaining to a lower state of the source, indicates spectral hardening with increasing intensity on time scales of months. 26 references

  2. Quasi-simultaneous ultraviolet, optical, and infrared observations of the BL Lacertae object PKS 0048-09

    Energy Technology Data Exchange (ETDEWEB)

    Falomo, R.; Bouchet, P.; Maraschi, L.; Treves, A.; Tanzi, E.G.

    1988-12-01

    This paper reports on quasi-simultaneous UV, optical, and IR observations of the BL Lac object PKS 0048-09, carried out on January 7-9, 1987, when the object was in a moderately high optical state. The data were used to derive a detailed energy distribution from about 10 to the 14th to about 2.5 x 10 to the 15th Hz. A comparison of observations obtained on January 7-9, 1987, with observations on September 12, 1986, pertaining to a lower state of the source, indicates spectral hardening with increasing intensity on time scales of months. 26 references.

  3. Quasi-simultaneous observations of BL Lac object Mrk 501 in X-ray, UV, visible, IR, and radio frequencies

    International Nuclear Information System (INIS)

    Kondo, Y.; Worrall, D.M.; Mushotzky, R.F.; Hackney, R.L.; Hackney, K.R.H.; Oke, J.B.; Yee, H.K.C.; Neugebauer, G.; Matthews, K.; Feldman, P.A.; Brown, R.L.

    1981-01-01

    Quasi-simultaneous observations of the BL Lac object Mrk 501 were performed for the first time at X-ray, ultraviolet, visible infrared, and radio frequencies. As the BL Lac objects are known to vary in their flux, such a ''quasi-instantaneous'' spectral energy profile is necessary in order to describe properly the energy generation mechanism. The observed spectral slope from the X-ray to UV regions is positive and continuous, but that from the mid-UV to visible light region becomes gradually flat and possibly turns down toward lower frequencies; the optical-radio emission cannot be accounted for by a single power law. Several theoretical models have been considered for the emission mechanism. In some cases quantitative comparison with the data is not practical. However, most of the models are, at least, not inconsistent with the observations. A quantitative comparison has been peformed with the synchroton self-Compton model; the total spectrum is found consistent with this model. The spectrum from visible light to X-ray is consistent with synchrotron radiation or with inverse-Compton scattering by a hot thermal cloud of electrons. The continuity of the spectral slope from X-ray to UV implied by the current data suggests that the previous estimates of the total luminosity of this BL Lac object has been underestimated by a factor of about 3 or 4

  4. Quasi-simultaneous observations of BL Lac object Mrk 501 in X-ray, UV, visible, IR, and radio frequencies

    Science.gov (United States)

    Kondo, Y.; Worrall, D. M.; Oke, J. B.; Yee, H. K. C.; Neugebauer, G.; Matthews, K.; Feldman, P. A.; Mushotzky, R. F.; Hackney, R. L.; Hackney, K. R. H.

    1981-01-01

    Observations in the X-ray, UV, visible, IR and radio regions of the BL Lac object Mrk 501 made over the course of two months are reported. The measurements were made with the A2 experiment on HEAO 1 (X-ray), the SWP and LWR cameras on IUE (UV), the 5-m Hale telescope (visible), the 2.5-m telescope at Mount Wilson (IR), the NRAO 92-m radio telescope at Green Bank (4750 MHz) and the 46-m radio telescope at the Algonquin Observatory (10275 and 10650 MHz). The quasi-simultaneously observed spectral slope is found to be positive and continuous from the X-ray to the UV, but to gradually flatten and possibly turn down from the mid-UV to the visible; the optical-radio emission cannot be accounted for by a single power law. The total spectrum is shown to be compatible with a synchrotron self-Compton emission mechanism, while the spectrum from the visible to the X-ray is consistent with synchrotron radiation or inverse-Compton scattering by a hot thermal electron cloud. The continuity of the spectrum from the UV to the X-ray is noted to imply a total luminosity greater than previous estimates by a factor of 3-4.

  5. Quasi-simultaneous observations of the BL Lac object MK 501 in X-ray, UV, visible, IR and radio frequencies

    Science.gov (United States)

    Kondo, D. M.; Worrall, D. M.; Mushotzky, R. F.; Hackney, R. L.; Hackney, K. H.; Oke, J. B.; Yee, H.; Neugebauer, G.; Matthews, K.; Feldman, P. A.

    1980-01-01

    Quasi-simultaneous observations of the BL Lacertae (Lac) objects MK 501 were performed for the first time at X-ray, ultraviolet, visible, infrared, and radio frequencies. The observed spectral slope from the X-ray to UV regions is positive and continuous, but that from the mid UV to visible light region becomes gradually flat and possibly turns down toward lower frequencies; the optical radio emission can not be accounted for by a single power law. Several theoretical models were considered for the emission mechanism. A quantitative comparison was performed with the synchrotron-self-Compton model; the total spectrum is found consistent with this model. The spectrum from visible light to X-ray is consistent with synchrotron radiation or with inverse-Compton scattering by a hot thermal cloud of electrons. The continuity of the spectral slope from X-ray to UV implied by the current data suggests that the previous estimates of the total luminosity of this BL Lac object is underestimated by a factor of about three or four.

  6. Observation of dipole bands in 144Sm

    International Nuclear Information System (INIS)

    Raut, R.; Ganguly, S.; Kshetri, R.; Banerjee, P.; Bhattacharya, S.; Dasmahapatra, B.; Mukherjee, A.; Sahasarkar, M.; Goswami, A.; Basu, S.K.; Bhattacharjee, T.; Mukherjee, G.; Chakraborty, A.; Ghughre, S.S.; Krishichayan; Mukhopadhyay, S.; Gangopadhyay, G.; Singh, A.K.

    2007-01-01

    The nucleus 144 Sm (Z=62, N=82), with its proximity to the shell closure and possibilities of particles and holes occupying high j orbitals, following appropriate excitations, is a suitable system for observation of dipole (MR) bands

  7. Quasi-Simultaneous Viscous-Inviscid Interaction for Transonic Airfoil Flow

    NARCIS (Netherlands)

    Veldman, Arthur E.P.

    2005-01-01

    Following Prandtl, a viscous-inviscid interaction (VII) method is presented, where the flow field is divided into a viscous shear layer and an inviscid outer region. Their coupling is performed with the quasi-simultaneous approach, making use of an appropriately chosen interaction law. Firstly, an

  8. Quasi-simultaneous OCT en-face imaging with two different depth resolutions

    International Nuclear Information System (INIS)

    Podoleanu, Adrian Gh; Cucu, Radu G; Rosen, Richard B; Dobre, George M; Rogers, John A; Jackson, David A

    2003-01-01

    We report a system capable of acquiring two quasi-simultaneous en-face optical coherence tomography (OCT) images of different depth resolution (one better than 20 μm and the other between 80 and 330 μm) at a frame rate of 2 Hz. The larger depth resolution image makes it ideal for target positioning in the OCT imaging of moving organs, such as eye fundus and cornea, as well as in the alignment of stacks of en-face OCT images. This role is similar to that of the confocal channel in a previously reported dual channel OCT/confocal imaging instrument. The system presented operates as a dual channel imaging instrument, where both channels operate on the OCT principle. We illustrate the functionality of the system with examples from a coin, skin from a finger and optic nerve in vivo

  9. Observations of banding in first-year Arctic sea ice

    Science.gov (United States)

    Cole, David M.; Eicken, Hajo; Frey, Karoline; Shapiro, Lewis H.

    2004-08-01

    Horizontal banding features, alternating dark and bright horizontal bands apparent in ice cores and stratigraphic cross sections have long been observed in first-year sea ice and are frequently associated with bands of high and low brine or gas porosity. Observations on the land-fast ice near Barrow, Alaska, in recent years have revealed particularly striking banding patterns and prompted a study of their macroscopic and microscopic characteristics. The banding patterns are quantified from photographs of full-depth sections of the ice, and examples are presented from the Chukchi Sea and Elson Lagoon. Statistics on band spacing are presented, and the growth records for three seasons are employed to estimate their time of formation. These data provide insight into the periodicity of the underlying phenomena. Micrographs are used to examine the microstructural variations associated with various banding features and to quantify the geometry of the constituent brine inclusions associated with high- and low-porosity bands. The micrography revealed that the area fraction of brine inclusions varied by a factor of nearly 3 through the more pronounced high- and low-porosity bands. Vertical micrographs obtained shortly after the materials' removal from the ice sheet showed that significantly larger inclusions form abruptly at the start of the high-porosity bands and frequently terminate abruptly at the end of the band. Crystallographic observations indicated that the high-porosity bands supported the nucleation and growth of crystals having substantially different orientations from the very well aligned columnar structure that characterized the bulk of the sheet.

  10. Deformation bands in porous carbonate grainstones: Field and laboratory observations

    NARCIS (Netherlands)

    Cilona, A.; Baud, P.; Tondi, E.; Agosta, F.; Vinciguerra, S.; Rustichelli, A.; Spiers, C.J.

    2012-01-01

    Recent field-based studies documented deformation bands in porous carbonates; these structures accommodate volumetric and/or shear strain by means of pore collapse, grain rotation and/or sliding. Microstructural observations of natural deformation bands in carbonates showed that, at advanced stages

  11. Proposed colour banded early warning observation charts for South ...

    African Journals Online (AJOL)

    Introduction of a colour banded observation chart should be combined with a clear communication strategy. The process should be used to change the organisational culture to be more proactive in initiating early intervention to reduce the burden of unintended complications. Keywords: Observation chart; Physiology; ...

  12. Whistler Triggered Upper Band Chorus Observed in Alaska

    Science.gov (United States)

    Hosseini, P.; Golkowski, M.

    2017-12-01

    VLF radiation from lightning discharges is one of several sources of energy injection into the inner magnetosphere from the Earth. Lightning discharges initially produce a broadband impulse or `sferic' but after propagation in the dispersive magnetosphere this waveform soon becomes quasi narrow band with the characteristic spectrographic form of the whistler. Most of the lightning induced VLF wave energy injected into the magnetosphere will be unducted with a k-vector which becomes increasingly oblique. Although unducted radiation is ubiquitous throughout the inner magnetosphere, it is generally of a low amplitude due to Landau damping and is not expected to produce strong nonlinear phenomena such as triggered emissions and chorus waves. However, VLF wave energy ducted or trapped in field-aligned plasma density enhancements can have relatively large amplitudes due to focusing and also linear cyclotron resonance growth. Therefore high amplitude ducted whistler waves can trigger a number of complex nonlinear phenomena. These include the triggering of VLF emissions and triggering of VLF hiss or chorus. Such phenomena are generally considered to result from nonlinear electron cyclotron phase trapping. Observation of such VLF emissions triggered by natural whistlers have been reported since the 1970s in Antarctica. We present observations of whistlers triggered upper band chorus emission from Alaska. Dispersion analyze of whistlers determine the L-shell range to be 4.5 clear frequency band gap between upper and lower band of the observed chorus emissions. The observations point to ducted chorus generation in the vicinity of the plasmapause boundary.

  13. Estimating Coastal Turbidity using MODIS 250 m Band Observations

    Science.gov (United States)

    Davies, James E.; Moeller, Christopher C.; Gunshor, Mathew M.; Menzel, W. Paul; Walker, Nan D.

    2004-01-01

    Terra MODIS 250 m observations are being applied to a Suspended Sediment Concentration (SSC) algorithm that is under development for coastal case 2 waters where reflectance is dominated by sediment entrained in major fluvial outflows. An atmospheric correction based on MODIS observations in the 500 m resolution 1.6 and 2.1 micron bands is used to isolate the remote sensing reflectance in the MODIS 25Om resolution 650 and 865 nanometer bands. SSC estimates from remote sensing reflectance are based on accepted inherent optical properties of sediment types known to be prevalent in the U.S. Gulf of Mexico coastal zone. We present our findings for the Atchafalaya Bay region of the Louisiana Coast, in the form of processed imagery over the annual cycle. We also apply our algorithm to selected sites worldwide with a goal of extending the utility of our approach to the global direct broadcast community.

  14. NARROW-K-BAND OBSERVATIONS OF THE GJ 1214 SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    Colón, Knicole D.; Gaidos, Eric, E-mail: colonk@hawaii.edu [Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, HI 96822 (United States)

    2013-10-10

    GJ 1214 is a nearby M dwarf star that hosts a transiting super-Earth-size planet, making this system an excellent target for atmospheric studies. Most studies find that the transmission spectrum of GJ 1214b is flat, which favors either a high mean molecular weight or cloudy/hazy hydrogen (H) rich atmosphere model. Photometry at short wavelengths (<0.7 μm) and in the K band can discriminate the most between these different atmosphere models for GJ 1214b, but current observations do not have sufficiently high precision. We present photometry of seven transits of GJ 1214b through a narrow K-band (2.141 μm) filter with the Wide Field Camera on the 3.8 m United Kingdom Infrared Telescope. Our photometric precision is typically 1.7 × 10{sup –3} (for a single transit), comparable with other ground-based observations of GJ 1214b. We measure a planet-star radius ratio of 0.1158 ± 0.0013, which, along with other studies, also supports a flat transmission spectrum for GJ 1214b. Since this does not exclude a scenario where GJ 1214b has an H-rich envelope with heavy elements that are sequestered below a cloud/haze layer, we compare K-band observations with models of H{sub 2} collision-induced absorption in an atmosphere for a range of temperatures. While we find no evidence for deviation from a flat spectrum (slope s = 0.0016 ± 0.0038), an H{sub 2}-dominated upper atmosphere (<60 mbar) cannot be excluded. More precise observations at <0.7 μm and in the K band, as well as a uniform analysis of all published data, would be useful for establishing more robust limits on atmosphere models for GJ 1214b.

  15. Observation of symmetry-protected topological band with ultracold fermions

    Science.gov (United States)

    Song, Bo; Zhang, Long; He, Chengdong; Poon, Ting Fung Jeffrey; Hajiyev, Elnur; Zhang, Shanchao; Liu, Xiong-Jun; Jo, Gyu-Boong

    2018-01-01

    Symmetry plays a fundamental role in understanding complex quantum matter, particularly in classifying topological quantum phases, which have attracted great interests in the recent decade. An outstanding example is the time-reversal invariant topological insulator, a symmetry-protected topological (SPT) phase in the symplectic class of the Altland-Zirnbauer classification. We report the observation for ultracold atoms of a noninteracting SPT band in a one-dimensional optical lattice and study quench dynamics between topologically distinct regimes. The observed SPT band can be protected by a magnetic group and a nonlocal chiral symmetry, with the band topology being measured via Bloch states at symmetric momenta. The topology also resides in far-from-equilibrium spin dynamics, which are predicted and observed in experiment to exhibit qualitatively distinct behaviors in quenching to trivial and nontrivial regimes, revealing two fundamental types of spin-relaxation dynamics related to bulk topology. This work opens the way to expanding the scope of SPT physics with ultracold atoms and studying nonequilibrium quantum dynamics in these exotic systems. PMID:29492457

  16. Multiflash whistlers in ELF-band observed at low latitude

    Directory of Open Access Journals (Sweden)

    A. K. Singh

    2011-01-01

    Full Text Available Multiflash whistler-like event in the ELF-band, observed during March 1998 at low latitude station Jammu, is reported. The most prominent feature of these events is the multiflash nature along with the decrease in frequency within a very short span of time resembling similar to terrestrial whistlers. The events have a significantly smaller time duration (0.5–3.5 s than those reported earlier from high, mid and low latitudes and also display a diurnal maximum occurring around 09:30 h (IST. There have been similar reportings from other latitudes, but whistlers in the ELF-band with a multiflash nature along with a precursor emission have never been reported. Lightning seems to be the dominant source for the ELF whistlers reported here.

  17. Aquarius L-Band Radiometers Calibration Using Cold Sky Observations

    Science.gov (United States)

    Dinnat, Emmanuel P.; Le Vine, David M.; Piepmeier, Jeffrey R.; Brown, Shannon T.; Hong, Liang

    2015-01-01

    An important element in the calibration plan for the Aquarius radiometers is to look at the cold sky. This involves rotating the satellite 180 degrees from its nominal Earth viewing configuration to point the main beams at the celestial sky. At L-band, the cold sky provides a stable, well-characterized scene to be used as a calibration reference. This paper describes the cold sky calibration for Aquarius and how it is used as part of the absolute calibration. Cold sky observations helped establish the radiometer bias, by correcting for an error in the spillover lobe of the antenna pattern, and monitor the long-term radiometer drift.

  18. W-band spaceborne radar observations of atmospheric river events

    Science.gov (United States)

    Matrosov, S. Y.

    2010-12-01

    While the main objective of the world first W-band radar aboard the CloudSat satellite is to provide vertically resolved information on clouds, it proved to be a valuable tool for observing precipitation. The CloudSat radar is generally able to resolve precipitating cloud systems in their vertical entirety. Although measurements from the liquid hydrometer layer containing rainfall are strongly attenuated, special retrieval approaches can be used to estimate rainfall parameters. These approaches are based on vertical gradients of observed radar reflectivity factor rather than on absolute estimates of reflectivity. Concurrent independent estimations of ice cloud parameters in the same vertical column allow characterization of precipitating systems and provide information on coupling between clouds and rainfall they produce. The potential of CloudSat for observations atmospheric river events affecting the West Coast of North America is evaluated. It is shown that spaceborne radar measurements can provide high resolution information on the height of the freezing level thus separating areas of rainfall and snowfall. CloudSat precipitation rate estimates complement information from the surface-based radars. Observations of atmospheric rivers at different locations above the ocean and during landfall help to understand evolutions of atmospheric rivers and their structures.

  19. Laboratory observation of hot bands of H+3

    International Nuclear Information System (INIS)

    Bawendi, M.G.; Rehfuss, B.D.; Oka, T.

    1990-01-01

    The (2ν 2 ,l=2 left-arrow ν 2 ), (2ν 2 ,l=0 left-arrow ν 2 ), and (ν 1 +ν 2 left-arrow ν 1 ) hot bands of H + 3 were observed. The vibrationally hot ions were produced in a liquid nitrogen cooled 6 kHz ac discharge using gas mixtures of H 2 and He. The spectra were detected in direct absorption using a newly extended tunable difference frequency spectrometer using both LiNbO 3 and LiIO 3 crystals as nonlinear optical elements. The range of this spectrometer is now ∼5300--∼1900 cm -1 . The positions of the rovibrational transitions compare extremely well with the theoretical predictions of Miller and Tennyson. A vibrational temperature study of the discharge indicates a significant population inversion between the ν 1 and ν 2 levels

  20. Observation of band gaps in the gigahertz range and deaf bands in a hypersonic aluminum nitride phononic crystal slab

    Science.gov (United States)

    Gorisse, M.; Benchabane, S.; Teissier, G.; Billard, C.; Reinhardt, A.; Laude, V.; Defaÿ, E.; Aïd, M.

    2011-06-01

    We report on the observation of elastic waves propagating in a two-dimensional phononic crystal composed of air holes drilled in an aluminum nitride membrane. The theoretical band structure indicates the existence of an acoustic band gap centered around 800 MHz with a relative bandwidth of 6.5% that is confirmed by gigahertz optical images of the surface displacement. Further electrical measurements and computation of the transmission reveal a much wider attenuation band that is explained by the deaf character of certain bands resulting from the orthogonality of their polarization with that of the source.

  1. Online process monitoring at quasi-simultaneous laser transmission welding using a 3D-scanner with integrated pyrometer

    Science.gov (United States)

    Schmailzl, A.; Steger, S.; Dostalek, M.; Hierl, S.

    2016-03-01

    Quasi-simultaneous laser transmission welding is a well-known joining technique for thermoplastics and mainly used in the automotive as well as in the medical industry. For process control usually the so called set-path monitoring is used, where the weld is specified as "good" if the irradiation time is inside a defined confidence interval. However, the detection of small-sized gaps or thermal damaged zones is not possible with this technique. The analyzation of the weld seam temperature during welding offers the possibility to overcome this problem. In this approach a 3D-scanner is used instead of a scanner with flat-field optic. By using a pyrometer in combination with a 3D-scanner no color-corrected optic is needed in order to provide that laser- and detection-spot are concentric. Experimental studies on polyethylene T-joints have shown that the quality of the signal is adequate, despite the use of an optical setup with a long working distance and a small optical aperture. The effects on temperature are studied for defects like a gap in the joining zone. Therefore a notch was milled into the absorbent polymer. In case of producing housings for electronic parts the effect of an electrical wire between the joining partners is also investigated. Both defects can be identified by a local temperature deviation even at a feed rate of four meters per second. Furthermore a strategy for signal-processing is demonstrated. By this, remaining defects can be identified. Consequently an online detection of local defects is possible, which makes a dynamic process control feasible.

  2. Observations of the initial stages of colloidal band formation

    Science.gov (United States)

    Li, Yanrong; Tagawa, Yoshiyuki; Yee, Andrew; Yoda, Minami

    2017-11-01

    A number of studies have shown that particles suspended in a conducting fluid near a wall are subject to wall-normal repulsive ``lift'' forces, even in the absence of interparticle interactions, in a flowing suspension. Evanescent-wave visualizations have shown that colloidal particles in a dilute (volume fractions negative zeta-potentials. Above a minimum ``threshold'' electric field magnitude |Emin | , the particles assemble into dense ``bands'' with cross-sectional dimensions of a few μm and length comparable to that of the channel (i.e., a few cm). The results suggest that the threshold field |Emin | is large enough so that there is a region of ``reverse'' flow, along the direction of the EO flow, near the wall. Visualization of a large segment of the channel (>300 hydraulic diameters) at frame rates as great as 1 kHz is used to determine banding maps for a variety of dilute colloidal suspensions and to investigate the initial stages of band formation over a wide range of flow conditions. Supported by US Army Research Office.

  3. SKS splitting observed at Romanian broad-band seismic network

    Science.gov (United States)

    Ivan, Marian; Popa, Mihaela; Ghica, Daniela

    2008-12-01

    Shear-wave splitting results are presented for the broad-band stations of the Romanian seismic network. For stations BUC1 and CRAR (located in Moesian Platform), IAS (in East-European Platform), TIRR and CVD (in Central Dobrudja-Black Sea microplate), TIM and DRGR (in Dacia-Tisza plate, including Apuseni Mts.), BURAR, BZS and GZR (in, or very close to the Carpathian Arc), the fast directions ( φ) are around 135°. The mean delay values ( δt) of the slow wave are slightly greater for the stations placed in platform areas ( δt ~ 1.5 s) than for the stations situated in the (proximity) of Carpathians ( δt ~ 1.2 s). For the MLR station located in the South-Western part of Vrancea area, at the Carpathian Bend, the fast direction is 48°, similar to VOIR station (located in Southern Carpathians, 70 km West of MLR). At VRI and PLOR, located in the North-Eastern part of Vrancea, the fast axis is oriented approximately on North-South direction, with a possible dependence of the splitting parameters with back azimuth. At least for some stations, the splitting results are not consistent with vertical coherent lithospheric anisotropy.

  4. Multi-band Observations of Gamma Ray Bursts

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    A statistical analysis to estimate the probable redshifts of host galaxies using the luminosity function ... shown that fading Optical Transient (OT) is observable over a couple of months from ... 99% confidence level) come from afterglow analysis.

  5. Radio Band Observations of Blazar Variability Margo F. Aller , Hugh ...

    Indian Academy of Sciences (India)

    gle dish monitoring and spatial resolution from VLBA imaging. Such measurements now available in all four ... linear-to-circular mode conversion in a region that is at least partially self- absorbed. Detailed analysis of ... Single dish monitoring observations from Metsähovi, Michigan (hereafter. UMRAO), and recently from the ...

  6. Observations of Terrestrial Nightglow (Meinel Bands) at King

    Science.gov (United States)

    Won, Young-In; Cho, Young-Min; Lee, Bang Yong; Kim, Jhoon; Chung, Jong Kyun; Kim, Yong Ha

    1999-12-01

    A Fourier Transform Spectrometer was used to study upper mesospheric thermodynamic by observing the hydroxyl(OH) emission. Rocket-born and satellited-born photometers place the peak emission near 87 μm. The instrument was installed in February 1999 at King Sejong station (62.22 deg S,301.25 deg E), Antarctica and has been in routine operation since then. An intensive operational effort has resulted in a substantial data between April and June, 1999. A harmonic analysis was carried out to examine information on the tidal characteristics. The measured amplitudes of the 12-hour oscillation are in the range of 2.4-3.7 K, which are in resonable agreement with theoretical model outputs. The harmonic analysis also revealed 8-hour oscillation which is not expected from the traditional theoretical studies. In addition, the observed 8-hour oscillations are apparent and sometimes dominate the temperature variation in the upper mesosphere.

  7. Calibration of VIIRS F1 Sensor Fire Detection Band Using lunar Observations

    Science.gov (United States)

    McIntire, Jeff; Efremova, Boryana; Xiong, Xiaoxiong

    2012-01-01

    Visible Infrared Imager Radiometer Suite (VIIRS) Fight 1 (Fl) sensor includes a fire detection band at roughly 4 microns. This spectral band has two gain states; fire detection occurs in the low gain state above approximately 345 K. The thermal bands normally utilize an on-board blackbody to provide on-orbit calibration. However, as the maximum temperature of this blackbody is 315 K, the low gain state of the 4 micron band cannot be calibrated in the same manner as the rest of the thermal bands. Regular observations of the moon provide an alternative calibration source. The lunar surface temperature has been recently mapped by the DIVINER sensor on the LRO platform. The periodic on-board high gain calibration along with the DIVINER surface temperatures was used to determine the emissivity and solar reflectance of the lunar surface at 4 microns; these factors and the lunar data are then used to fit the low gain calibration coefficients of the 4 micron band. Furthermore, the emissivity of the lunar surface is well known near 8.5 microns due to the Christiansen feature (an emissivity maximum associated with Si-O stretching vibrations) and the solar reflectance is negligible. Thus, the 8.5 micron band is used for relative calibration with the 4 micron band to de-trend any temporal variations. In addition, the remaining thermal bands are analyzed in a similar fashion, with both calculated emissivities and solar reflectances produced.

  8. Observations of 40-70 micron bands of ice in IRAS 09371 + 1212 and other stars

    Science.gov (United States)

    Omont, A.; Forveille, T.; Moseley, S. H.; Glaccum, W. J.; Harvey, P. M.; Likkel, L.; Loewenstein, R. F.; Lisse, C. M.

    1990-01-01

    IRAS 09371 + 1212 is still an absolutely unique object. This M giant star, with circumstellar CO and a spectacular bipolar nebula, displays unique IRAS FIR colors which had been attributed to strong emission in the 40-70-micron bands of ice, as subsequently supported by the observation of a strong 3.1-micron absorption band. The results of the KAO observations have confirmed its unusual nature: the far-infrared bands of ice are by far the strongest known. Its dust temperature, 50 K or less, is by far the lowest known for a late-type circumstellar envelope.

  9. Multi-Band Intra-Night Optical Variability of BL Lacertae

    Directory of Open Access Journals (Sweden)

    Haritma Gaur

    2017-12-01

    Full Text Available We monitored BL Lacertae frequently during 2014–2016 when it was generally in a high state. We searched for intra-day variability for 43 nights using quasi-simultaneous measurements in the B, V, R, and I bands (totaling 143 light curves; the typical sampling interval was about eight minutes. On hour-like timescales, BL Lac exhibited significant variations during 13 nights in various optical bands. Significant spectral variations are seen during most of these nights such that the optical spectrum becomes bluer when brighter. The amplitude of variability is usually greater for longer observations but is lower when BL Lac is brighter. No evidence for periodicities or characteristic variability time-scales in the light curves was found. The color variations are mildly chromatic on long timescales.

  10. An Observational Study of Intermediate Band Students' Self-Regulated Practice Behaviors

    Science.gov (United States)

    Miksza, Peter; Prichard, Stephanie; Sorbo, Diana

    2012-01-01

    The purpose of this study was to investigate intermediate musicians' self-regulated practice behaviors. Thirty sixth- through eighth-grade students were observed practicing band repertoire individually for 20 min. Practice sessions were coded according to practice frame frequency and duration, length of musical passage selected, most prominent…

  11. The Low Band Observatory (LOBO): Expanding the VLA Low Frequency Commensal System for Continuous, Broad-band, sub-GHz Observations

    Science.gov (United States)

    Kassim, Namir E.; Clarke, Tracy E.; Helmboldt, Joseph F.; Peters, Wendy M.; Brisken, Walter; Hyman, Scott D.; Polisensky, Emil; Hicks, Brian

    2015-01-01

    The Naval Research Laboratory (NRL) and the National Radio Astronomy Observatory (NRAO) are currently commissioning the VLA Low Frequency Ionosphere and Transient Experiment (VLITE) on a subset of JVLA antennas at modest bandwidth. Its bounded scientific goals are to leverage thousands of JVLA on-sky hours per year for ionospheric and transient studies, and to demonstrate the practicality of a prime-focus commensal system on the JVLA. Here we explore the natural expansion of VLITE to a full-antenna, full-bandwidth Low Band Observatory (LOBO) that would follow naturally from a successful VLITE experience. The new Low Band JVLA receivers, coupled with the existing primary focus feeds, can access two frequency bands: 4 band (54 - 86 MHz) and P band (236-492 MHz). The 4 band feeds are newly designed and now undergoing testing. If they prove successful then they can be permanently mounted at the primary focus, unlike their narrow band predecessors. The combination of Low Band receivers and fixed, primary-focus feeds could provide continuous, broad-band data over two complimentary low-frequency bands. The system would also leverage the relatively large fields-of-view of ~10 degrees at 4 band, and ~2.5 degrees at P band, coupling an excellent survey capability with a natural advantage for serendipitous discoveries. We discuss the compelling science case that flows from LOBO's robust imaging and time domain capabilities coupled with thousands of hours of wide-field, JVLA observing time each year. We also touch on the possibility to incorporate Long Wavelength Array (LWA) stations as additional 'dishes' through the LOBO backend, to improve calibration and sensitivity in LOBO's 4 band.

  12. Experimental observation on asymmetric energy flux within the forbidden frequency band in the LC transmission line

    International Nuclear Information System (INIS)

    Tao Feng; Chen Weizhong; Pan Junting; Xu Wen; Du Sidan

    2012-01-01

    We study the energy flux in a nonlinear electrical transmission line consisting of two coupled segments which are identical in structure and different in parameters. The asymmetry of energy flux caused by nonlinear wave has been observed experimentally in the forbidden band of the line. The experiment shows whether the energy can flow through the transmission line depends on the amplitude of the boundary driving voltages, which can be well explained in the theoretical framework of nonlinear supratransmission. The numerical simulation based on Kirchhoff’s laws further verifies the existence of the asymmetric energy flux in the forbidden band.

  13. Multi-band, multi-epoch observations of the transiting warm Jupiter WASP-80b

    Energy Technology Data Exchange (ETDEWEB)

    Fukui, Akihiko; Kuroda, Daisuke [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asakuchi, Okayama 719-0232 (Japan); Kawashima, Yui; Ikoma, Masahiro; Kurosaki, Kenji [Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo, 7-3-1 Bunkyo-ku, Tokyo 113-0033 (Japan); Narita, Norio; Nishiyama, Shogo; Takahashi, Yasuhiro H.; Nagayama, Shogo [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Onitsuka, Masahiro; Baba, Haruka; Ryu, Tsuguru [The Graduate University for Advanced Studies, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Ita, Yoshifusa; Onozato, Hiroki [Astronomical Institute, Graduate School of Science, Tohoku University, 6-3 Aramaki Aoba, Aoba-ku, Sendai, Miyagi 980-8578 (Japan); Hirano, Teruyuki; Kawauchi, Kiyoe [Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8551 (Japan); Hori, Yasunori [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Nagayama, Takahiro [Department of Physics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan); Tamura, Motohide [Department of Astronomy, Graduate School of Science, The University of Tokyo, and National Astronomical Observatory of Japan (Japan); Kawai, Nobuyuki, E-mail: afukui@oao.nao.ac.jp [Department of Physics, Tokyo Institute of Technology, 2-12-1, Oookayama, Meguro, Tokyo 152-8551 (Japan); and others

    2014-08-01

    WASP-80b is a warm Jupiter transiting a bright late-K/early-M dwarf, providing a good opportunity to extend the atmospheric study of hot Jupiters toward the lower temperature regime. We report multi-band, multi-epoch transit observations of WASP-80b by using three ground-based telescopes covering from optical (g', R{sub c}, and I{sub c} bands) to near-infrared (NIR; J, H, and K{sub s} bands) wavelengths. We observe 5 primary transits, each in 3 or 4 different bands simultaneously, obtaining 17 independent transit light curves. Combining them with results from previous works, we find that the observed transmission spectrum is largely consistent with both a solar abundance and thick cloud atmospheric models at a 1.7σ discrepancy level. On the other hand, we find a marginal spectral rise in the optical region compared to the NIR region at the 2.9σ level, which possibly indicates the existence of haze in the atmosphere. We simulate theoretical transmission spectra for a solar abundance but hazy atmosphere, finding that a model with equilibrium temperature of 600 K can explain the observed data well, having a discrepancy level of 1.0σ. We also search for transit timing variations, but find no timing excess larger than 50 s from a linear ephemeris. In addition, we conduct 43 day long photometric monitoring of the host star in the optical bands, finding no significant variation in the stellar brightness. Combined with the fact that no spot-crossing event is observed in the five transits, our results confirm previous findings that the host star appears quiet for spot activities, despite the indications of strong chromospheric activities.

  14. CONSTRAINING THE SOLAR CORONAL MAGNETIC FIELD STRENGTH USING SPLIT-BAND TYPE II RADIO BURST OBSERVATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Kishore, P.; Ramesh, R.; Hariharan, K.; Kathiravan, C. [Indian Institute of Astrophysics, 2nd Block, Koramangala, Bangalore—560034 (India); Gopalswamy, N., E-mail: kishore@iiap.res.in [Code 671, Solar Physics Laboratory, NASA/GSFC, Greenbelt, MD 20771 (United States)

    2016-11-20

    We report on low-frequency radio (85–35 MHz) spectral observations of four different type II radio bursts, which exhibited fundamental-harmonic emission and split-band structure. Each of the bursts was found to be closely associated with a whitelight coronal mass ejection (CME) close to the Sun. We estimated the coronal magnetic field strength from the split-band characteristics of the bursts, by assuming a model for the coronal electron density distribution. The choice of the model was constrained, based on the following criteria: (1) when the radio burst is observed simultaneously in the upper and lower bands of the fundamental component, the location of the plasma level corresponding to the frequency of the burst in the lower band should be consistent with the deprojected location of the leading edge (LE) of the associated CME; (2) the drift speed of the type II bursts derived from such a model should agree closely with the deprojected speed of the LE of the corresponding CMEs. With the above conditions, we find that: (1) the estimated field strengths are unique to each type II burst, and (2) the radial variation of the field strength in the different events indicate a pattern. It is steepest for the case where the heliocentric distance range over which the associated burst is observed is closest to the Sun, and vice versa.

  15. Mini-RF S- and X-band Bistatic Observations of the Floor of Cabeus Crater

    Science.gov (United States)

    Patterson, Gerald Wesley; Stickle, Angela; Turner, Franklin; Jensen, James; Cahill, Joshua; Mini-RF Team

    2017-10-01

    The Mini-RF instrument aboard NASA’s Lunar Reconnaissance Orbiter (LRO) is a hybrid dual-polarized synthetic aperture radar (SAR) and operates in concert with the Arecibo Observatory (AO) and the Goldstone deep space communications complex 34 meter antenna DSS-13 to collect S- and X-band bistatic radar data of the Moon. Bistatic radar data provide a means to probe the near subsurface for the presence of water ice, which exhibits a strong response in the form of a Coherent Backscatter Opposition Effect (CBOE). This effect has been observed in radar data for the icy surfaces of the Galilean satellites, the polar caps of Mars, polar craters on Mercury, and terrestrial ice sheets in Greenland. Previous work using Mini-RF S-band (12.6 cm) bistatic data suggests the presence of a CBOE associated with the floor of the lunar south polar crater Cabeus. The LRO spacecraft has begun its third extended mission. For this phase of operations Mini-RF is leveraging the existing AO architecture to make S-band radar observations of additional polar craters (e.g., Haworth, Shoemaker, Faustini). The purpose of acquiring these data is to determine whether other polar craters exhibit the response observed for Cabeus. Mini-RF has also initiated a new mode of operation that utilizes the X-band (4.2cm) capability of the instrument receiver and a recently commissioned X/C-band transmitter within the Deep Space Network’s (DSN) Goldstone complex to collect bistatic X-band data of the Moon. The purpose of acquiring these data is to constrain the depth/thickness of materials that exhibit a CBOE response - with an emphasis on observing the floor of Cabeus. Recent Mini-RF X-band observations of the floors of the craters Cabeus do not show evidence for a CBOE. This would suggest that the upper ~0.5 meters of the regolith for the floor of Cabeus do not harber water ice in a form detectable at 4.2 cm wavelengths.

  16. Typhoon 9707 observations with the MU radar and L-band boundary layer radar

    Directory of Open Access Journals (Sweden)

    M. Teshiba

    2001-08-01

    Full Text Available Typhoon 9707 (Opal was observed with the VHF-band Middle and Upper atmosphere (MU radar, an L-band boundary layer radar (BLR, and a vertical-pointing C-band meteorological radar at the Shigaraki MU Observatory in Shiga prefecture, Japan on 20 June 1997. The typhoon center passed about 80 km southeast from the radar site. Mesoscale precipitating clouds developed due to warm-moist airmass transport from the typhoon, and passed over the MU radar site with easterly or southeasterly winds. We primarily present the wind behaviour including the vertical component which a conventional meteorological Doppler radar cannot directly observe, and discuss the relationship between the wind behaviour of the typhoon and the precipitating system. To investigate the dynamic structure of the typhoon, the observed wind was divided into radial and tangential wind components under the assumption that the typhoon had an axi-symmetric structure. Altitude range of outflow ascended from 1–3 km to 2–10 km with increasing distance (within 80–260 km range from the typhoon center, and in-flow was observed above and below the outflow. Outflow and inflow were associated with updraft and downdraft, respectively. In the tangential wind, the maximum speed of counterclockwise winds was confirmed at 1–2 km altitudes. Based on the vertical velocity and the reflectivity obtained with the MU radar and the C-band meteorological radar, respectively, precipitating clouds, accompanied by the wind behaviour of the typhoon, were classified into stratiform and convective precipitating clouds. In the stratiform precipitating clouds, a vertical shear of radial wind and the maximum speed of counterclockwise wind were observed. There was a strong reflectivity layer called a ‘bright band’ around the 4.2 km altitude. We confirmed strong updrafts and down-drafts below and above it, respectively, and the existence of a relatively dry layer around the bright band level from radiosonde

  17. Typhoon 9707 observations with the MU radar and L-band boundary layer radar

    Directory of Open Access Journals (Sweden)

    M. Teshiba

    Full Text Available Typhoon 9707 (Opal was observed with the VHF-band Middle and Upper atmosphere (MU radar, an L-band boundary layer radar (BLR, and a vertical-pointing C-band meteorological radar at the Shigaraki MU Observatory in Shiga prefecture, Japan on 20 June 1997. The typhoon center passed about 80 km southeast from the radar site. Mesoscale precipitating clouds developed due to warm-moist airmass transport from the typhoon, and passed over the MU radar site with easterly or southeasterly winds. We primarily present the wind behaviour including the vertical component which a conventional meteorological Doppler radar cannot directly observe, and discuss the relationship between the wind behaviour of the typhoon and the precipitating system. To investigate the dynamic structure of the typhoon, the observed wind was divided into radial and tangential wind components under the assumption that the typhoon had an axi-symmetric structure. Altitude range of outflow ascended from 1–3 km to 2–10 km with increasing distance (within 80–260 km range from the typhoon center, and in-flow was observed above and below the outflow. Outflow and inflow were associated with updraft and downdraft, respectively. In the tangential wind, the maximum speed of counterclockwise winds was confirmed at 1–2 km altitudes. Based on the vertical velocity and the reflectivity obtained with the MU radar and the C-band meteorological radar, respectively, precipitating clouds, accompanied by the wind behaviour of the typhoon, were classified into stratiform and convective precipitating clouds. In the stratiform precipitating clouds, a vertical shear of radial wind and the maximum speed of counterclockwise wind were observed. There was a strong reflectivity layer called a ‘bright band’ around the 4.2 km altitude. We confirmed strong updrafts and down-drafts below and above it, respectively, and the existence of a relatively dry layer around the bright band level from radiosonde

  18. Soil moisture estimation by assimilating L-band microwave brightness temperature with geostatistics and observation localization.

    Directory of Open Access Journals (Sweden)

    Xujun Han

    Full Text Available The observation could be used to reduce the model uncertainties with data assimilation. If the observation cannot cover the whole model area due to spatial availability or instrument ability, how to do data assimilation at locations not covered by observation? Two commonly used strategies were firstly described: One is covariance localization (CL; the other is observation localization (OL. Compared with CL, OL is easy to parallelize and more efficient for large-scale analysis. This paper evaluated OL in soil moisture profile characterizations, in which the geostatistical semivariogram was used to fit the spatial correlated characteristics of synthetic L-Band microwave brightness temperature measurement. The fitted semivariogram model and the local ensemble transform Kalman filter algorithm are combined together to weight and assimilate the observations within a local region surrounding the grid cell of land surface model to be analyzed. Six scenarios were compared: 1_Obs with one nearest observation assimilated, 5_Obs with no more than five nearest local observations assimilated, and 9_Obs with no more than nine nearest local observations assimilated. The scenarios with no more than 16, 25, and 36 local observations were also compared. From the results we can conclude that more local observations involved in assimilation will improve estimations with an upper bound of 9 observations in this case. This study demonstrates the potentials of geostatistical correlation representation in OL to improve data assimilation of catchment scale soil moisture using synthetic L-band microwave brightness temperature, which cannot cover the study area fully in space due to vegetation effects.

  19. Soil moisture estimation by assimilating L-band microwave brightness temperature with geostatistics and observation localization.

    Science.gov (United States)

    Han, Xujun; Li, Xin; Rigon, Riccardo; Jin, Rui; Endrizzi, Stefano

    2015-01-01

    The observation could be used to reduce the model uncertainties with data assimilation. If the observation cannot cover the whole model area due to spatial availability or instrument ability, how to do data assimilation at locations not covered by observation? Two commonly used strategies were firstly described: One is covariance localization (CL); the other is observation localization (OL). Compared with CL, OL is easy to parallelize and more efficient for large-scale analysis. This paper evaluated OL in soil moisture profile characterizations, in which the geostatistical semivariogram was used to fit the spatial correlated characteristics of synthetic L-Band microwave brightness temperature measurement. The fitted semivariogram model and the local ensemble transform Kalman filter algorithm are combined together to weight and assimilate the observations within a local region surrounding the grid cell of land surface model to be analyzed. Six scenarios were compared: 1_Obs with one nearest observation assimilated, 5_Obs with no more than five nearest local observations assimilated, and 9_Obs with no more than nine nearest local observations assimilated. The scenarios with no more than 16, 25, and 36 local observations were also compared. From the results we can conclude that more local observations involved in assimilation will improve estimations with an upper bound of 9 observations in this case. This study demonstrates the potentials of geostatistical correlation representation in OL to improve data assimilation of catchment scale soil moisture using synthetic L-band microwave brightness temperature, which cannot cover the study area fully in space due to vegetation effects.

  20. Optical observations of the nearby galaxy IC342 with narrow band [SII] and Hα filters. I

    Directory of Open Access Journals (Sweden)

    Vučetić M.M.

    2013-01-01

    Full Text Available We present observations of a portion of the nearby spiral galaxy IC342 using narrow band [SII] and Hα filters. These observations were carried out in November 2011 with the 2m RCC telescope at Rozhen National Astronomical Observatory in Bulgaria. In this paper we report coordinates, diameters, Hα and [SII] fluxes for 203 HII regions detected in two fields of view in IC342 galaxy. The number of detected HII regions is 5 times higher than previously known in these two parts of the galaxy. [Projekat Ministarstva nauke Republike Srbije, br. 176005: Emission nebulae: structure and evolution

  1. Observations of the Galaxy NGC 3077 in the Narrow-Band [S II] and Hα Filters

    Directory of Open Access Journals (Sweden)

    Andjelić M.

    2011-09-01

    Full Text Available We present observations of the H I tidal arm near a dwarf galaxy NGC 3077 (member of the M81 galaxy group in the narrow-band [S II] and Hα filters. Observations were carried out in 2011 March with the 2 m RCC telescope at the NAO Rozhen, Bulgaria. Our search for possible supernova remnant candidates (identified as sources with enhanced [S II] emission relative to their Hα emission in this region yielded no sources of this kind. Nevertheless, we found a number of objects with significant Hα emission that probably represent uncatalogued, low brightness H II regions.

  2. Observation of dark-current signals from the S-band structures of the SLAC linac

    International Nuclear Information System (INIS)

    Assmann, R.; Decker, F.J.; Seidel, M.; Siemann, R.H.; Whittum, D.

    1997-07-01

    It is well known that the electro-magnetic fields in high-gradient RF structures can cause electron emission from the metallic structure walls. If the emitted electrons are captured and accelerated by the accelerating fields so-called dark-current is induced. Dark-currents have been measured and studied for various RF-structures. In this paper the authors present measurements of RF induced signals for the SLC S-band structures. For nominal gradients of 17 MV/m it is shown that the dark-current can be strong enough to significantly reduce the signal-to-noise ratio of the SLC beam wire scanners. They also show results from RF measurements in the dipole band. The measurements are compared to more direct observations of dark-current and it is tried to connect the results to possible effects on the accelerated particle beam

  3. REFIR/BB initial observations in the water vapour rotational band: Results from a field campaign

    International Nuclear Information System (INIS)

    Esposito, F.; Grieco, G.; Leone, L.; Restieri, R.; Serio, C.; Bianchini, G.; Palchetti, L.; Pellegrini, M.; Cuomo, V.; Masiello, G.; Pavese, G.

    2007-01-01

    There is a growing interest in the far infrared spectral region 17-50 μm as a remote sensing tool in atmospheric sciences, since this portion of the spectrum contains the characteristic molecular rotational band for water vapour. Much of the Earth energy lost to space is radiated through this spectral region. The Radiation Explorer in the Far InfraRed Breadboard (REFIR/BB) spectrometer was born because of the quest to make observations in the far infrared. REFIR/BB is a Fourier Transform Spectrometer with a sampling resolution of 0.5 cm -1 and it was tested for the first time in the field to check its reliability and radiometric performance. The field campaign was held at Toppo di Castelgrande (40 o 49' N, 15 o 27' E, 1258 m a. s. l.), a mountain site in South Italy. The spectral and radiometric performance of the instrument and initial observations are shown in this paper. Comparisons to both (1) BOMEM MR100 Fourier Transform spectrometer observations and (2) line-by-line radiative transfer calculations for selected clear sky are presented and discussed. These comparisons (1) show a very nice agreement between radiance measured by REFIR/BB and by BOMEM MR100 and (2) demonstrate that REFIR/BB accurately observes the very fine spectral structure in the water vapour rotational band

  4. DEEP U BAND AND R IMAGING OF GOODS-SOUTH: OBSERVATIONS, DATA REDUCTION AND FIRST RESULTS ,

    International Nuclear Information System (INIS)

    Nonino, M.; Cristiani, S.; Vanzella, E.; Dickinson, M.; Reddy, N.; Rosati, P.; Grazian, A.; Giavalisco, M.; Kuntschner, H.; Fosbury, R. A. E.; Daddi, E.; Cesarsky, C.

    2009-01-01

    We present deep imaging in the U band covering an area of 630 arcmin 2 centered on the southern field of the Great Observatories Origins Deep Survey (GOODS). The data were obtained with the VIMOS instrument at the European Southern Observatory (ESO) Very Large Telescope. The final images reach a magnitude limit U lim ∼ 29.8 (AB, 1σ, in a 1'' radius aperture), and have good image quality, with full width at half-maximum ∼0.''8. They are significantly deeper than previous U-band images available for the GOODS fields, and better match the sensitivity of other multiwavelength GOODS photometry. The deeper U-band data yield significantly improved photometric redshifts, especially in key redshift ranges such as 2 lim ∼ 29 (AB, 1σ, 1'' radius aperture), and image quality ∼0.''75. We discuss the strategies for the observations and data reduction, and present the first results from the analysis of the co-added images.

  5. Synthetic profile analysis of the observed (0,0) Swan band of Comet Halley

    International Nuclear Information System (INIS)

    Krishna swamy, K.S.

    1991-01-01

    The time-dependent rotational population distribution for the (0,0) band of the Swan system was carried out. These population distributions are used to calculate the synthetic spectra over the wavelength region 5165-5132 A for comparing with the excellent spectra of Lambert et al. (1990) for Comet Halley. The synthetic spectra for the rotational population distribution corresponding to a time interval of about 8000 sec gives a good fit to the observed spectra over the whole special region. This seems to indicate that the level population does not appear to have reached the steady state values. 16 refs

  6. IR thermographic observation and shear bands plasticity analysis in Fe-based metallic glass

    International Nuclear Information System (INIS)

    Bouzakher, B.; Benameur, T.; Sidhom, H.

    2009-01-01

    Infrared thermography observation and in situ atomic force microscopy characterization were carried out to investigate the mechanical damage processes at the edge-notch region of large ribbons of Fe 78 Si 10 B 12 metallic glass. An obvious thermoelastic and inelastic degradation phenomenon was observed ahead at the notched region of the specimens, which probably result from free volume accumulation process and shear band activity during plane stress solicitations. Moreover, AFM topographic and frictional analysis of changes in the crack path during stable crack propagation regime revealed a periodic morphology evolution, formation of nanoscale damage cavity in the range of 20-140 nm and a maximum temperature rise ahead of the pre-crack tip was found in the order of 1.5 deg. C. The nanometer scaled shear offset, discreteness and shear bands density were determined. While these key parameters play a role in observing a large plastic zone in front of the crack, however they are unable to explain the distinct intrinsic ductility of some monolithic metallic glasses. A general Mohr-Coulomb-type constitutive description was used to deduce analytic expressions for prediction of the variation of hydrostatic component of the applied stress to the shear stress ratio as function of Poisson's ratio.

  7. Optimizing mesoscopic two-band superconductors for observation of fractional vortex states

    Energy Technology Data Exchange (ETDEWEB)

    Piña, Juan C. [Departamento de Física, Universidade Federal de Pernambuco, Cidade Universitária, 50670-901 Recife, PE (Brazil); Núcleo de Tecnologia, CAA, Universidade Federal de Pernambuco, 55002-970 Caruaru, PE (Brazil); Souza Silva, Clécio C. de, E-mail: clecio@df.ufpe [Departamento de Física, Universidade Federal de Pernambuco, Cidade Universitária, 50670-901 Recife, PE (Brazil); Milošević, Milorad V. [Departamento de Física, Universidade Federal do Ceará, 60455-900 Fortaleza, Ceará (Brazil); Departement Fysica, Universiteit Antwerpen, Groenenborgerlaan 171, B-2020 Antwerpen (Belgium)

    2014-08-15

    Highlights: • Observation of fractional vortices in two-band superconductors of broad size range. • There is a minimal sample size for observing each particular fractional state. • Optimal value for stability of each fractional state is determined. • A suitable magnetic dot enhances stability even further. - Abstract: Using the two-component Ginzburg–Landau model, we investigate the effect of sample size and magnitude and homogeneity of external magnetic field on the stability of fractional vortex states in a mesoscopic two-band superconducting disk. We found that each fractional state has a preferable sample size, for which the range of applied field in which the state is stable is pronouncedly large. Vice versa, there exists an optimal magnitude of applied field for which a large range of possible sample radii will support the considered fractional state. Finally, we show that the stability of fractional states can be enhanced even further by magnetic nanostructuring of the sample, i.e. by suitably chosen geometrical parameters and magnetic moment of a ferromagnetic dot placed on top of the superconducting disk.

  8. Mesoscale ionospheric electrodynamics of omega bands determined from ground-based electromagnetic and satellite optical observations

    Directory of Open Access Journals (Sweden)

    O. Amm

    2005-02-01

    Full Text Available We present ground-based electromagnetic data from the MIRACLE and BEAR networks and satellite optical observations from the UVI and PIXIE instruments on the Polar satellite of an omega band event over Northern Scandinavia on 26 June 1998, which occured close to the morning side edge of a substorm auroral bulge. Our analysis of the data concentrates on one omega band period from 03:18-03:27 UT, for which we use the method of characteristics combined with an analysis of the UVI and PIXIE data to derive a time series of instantaneous, solely data-based distributions of the mesoscale ionospheric electrodynamic parameters with a 1-min time resolution. In addition, the AMIE method is used to derive global Hall conductance patterns. Our results show that zonally alternating regions of enhanced ionospheric conductances ("tongues" up to ~60S and low conductance regions are associated with the omega bands. The tongues have a poleward extension of ~400km from their base and a zonal extension of ~380km. While they are moving coherently eastward with a velocity of ~770ms-1, the structures are not strictly stationary. The current system of the omega band can be described as a superposition of two parts: one consists of anticlockwise rotating Hall currents around the tongues, along with Pedersen currents, with a negative divergence in their centers. The sign of this system is reversing in the low conductance areas. It causes the characteristic ground magnetic signature. The second part consists of zonally aligned current wedges of westward flowing Hall currents and is mostly magnetically invisible below the ionosphere. This system dominates the field-aligned current (FAC pattern and causes alternating upward and downward FAC at the flanks of the tongues with maximum upward FAC of ~25µA m-2. The total FAC of ~2MA are comparable to the ones diverted inside a westward traveling surge. Throughout the event, the overwhelming part of the FAC are associated with

  9. Mesoscale ionospheric electrodynamics of omega bands determined from ground-based electromagnetic and satellite optical observations

    Directory of Open Access Journals (Sweden)

    O. Amm

    2005-02-01

    Full Text Available We present ground-based electromagnetic data from the MIRACLE and BEAR networks and satellite optical observations from the UVI and PIXIE instruments on the Polar satellite of an omega band event over Northern Scandinavia on 26 June 1998, which occured close to the morning side edge of a substorm auroral bulge. Our analysis of the data concentrates on one omega band period from 03:18-03:27 UT, for which we use the method of characteristics combined with an analysis of the UVI and PIXIE data to derive a time series of instantaneous, solely data-based distributions of the mesoscale ionospheric electrodynamic parameters with a 1-min time resolution. In addition, the AMIE method is used to derive global Hall conductance patterns. Our results show that zonally alternating regions of enhanced ionospheric conductances ("tongues" up to ~60S and low conductance regions are associated with the omega bands. The tongues have a poleward extension of ~400km from their base and a zonal extension of ~380km. While they are moving coherently eastward with a velocity of ~770ms-1, the structures are not strictly stationary. The current system of the omega band can be described as a superposition of two parts: one consists of anticlockwise rotating Hall currents around the tongues, along with Pedersen currents, with a negative divergence in their centers. The sign of this system is reversing in the low conductance areas. It causes the characteristic ground magnetic signature. The second part consists of zonally aligned current wedges of westward flowing Hall currents and is mostly magnetically invisible below the ionosphere. This system dominates the field-aligned current (FAC pattern and causes alternating upward and downward FAC at the flanks of the tongues with maximum upward FAC of ~25µA m-2. The total FAC of ~2MA are comparable to the ones diverted inside a westward traveling surge. Throughout the event, the overwhelming part of the FAC

  10. Field observations of mating behavior in the neck-banded snake Scaphiodontophis annulatus (Serpentes: Colubridae

    Directory of Open Access Journals (Sweden)

    Mahmood Sasa

    2006-06-01

    Full Text Available We observed the mating behavior of the neck-banded snake Scaphiodontophis annulatus (a common species of colubrid in the South Pacific of Costa Rica in the pre-montane wet forest of Las Cruces Biological Station (San Vito de Java, Costa Rica. Three S. annulatus were observed during courtship between 10-12 AM in a patch of primary forest. The two males were observed to interact with the female, but not signs of male-male agonistic interactions were observed. Their behavior includes grabbing and holding the female, copula, and biting during the copula. Rev. Biol. Trop. 54(2: 647-650. Epub 2006 Jun 01.El comportamiento de apareamiento es descrito para la serpiente Scaphiodontophis annulatus, una especie de colúbrido común en el Pacífico sur de Costa Rica. El comportamiento incluye capturar y sujetar a la hembra, mordiscos durante la cópula y coito. Dos machos fueron observados al interactuar con una sola hembra, pero no se detectó señales de interacciones antagónicas macho-macho.

  11. Strong RFI observed in protected 21 cm band at Zurich observatory, Switzerland

    Science.gov (United States)

    Monstein, C.

    2014-03-01

    While testing a new antenna control software tool, the telescope was moved to the most western azimuth position pointing to our own building. While de-accelerating the telescope, the spectrometer showed strong broadband radio frequency interference (RFI) and two single-frequency carriers around 1412 and 1425 MHz, both of which are in the internationally protected band. After lengthy analysis it was found out, that the Webcam AXIS2000 was the source for both the broadband and single-frequency interference. Switching off the Webcam solved the problem immediately. So, for future observations of 21 cm radiation, all nearby electronics has to be switched off. Not only the Webcam but also all unused PCs, printers, networks, monitors etc.

  12. Wide-banded NTC radiation: local to remote observations by the four Cluster satellites

    Directory of Open Access Journals (Sweden)

    P. M. E. Décréau

    2015-10-01

    Full Text Available The Cluster multi-point mission offers a unique collection of non-thermal continuum (NTC radio waves observed in the 2–80 kHz frequency range over almost 15 years, from various view points over the radiating plasmasphere. Here we present rather infrequent case events, such as when primary electrostatic sources of such waves are embedded within the plasmapause boundary far from the magnetic equatorial plane. The spectral signature of the emitted electromagnetic waves is structured as a series of wide harmonic bands within the range covered by the step in plasma frequency encountered at the boundary. Developing the concept that the frequency distance df between harmonic bands measures the magnetic field magnitude B at the source (df = Fce, electron gyrofrequency, we analyse three selected events. The first one (studied in Grimald et al., 2008 presents electric field signatures observed by a Cluster constellation of small size (~ 200 to 1000 km spacecraft separation placed in the vicinity of sources. The electric field frequency spectra display frequency peaks placed at frequencies fs = n df (n being an integer, with df of the order of Fce values encountered at the plasmapause by the spacecraft. The second event, taken from the Cluster tilt campaign, leads to a 3-D view of NTC waves ray path orientations and to a localization of a global source region at several Earth radii (RE from Cluster (Décréau et al., 2013. The measured spectra present successive peaks placed at fs ~ (n+ 1/2 df. Next, considering if both situations might be two facets of the same phenomenon, we analyze a third event. The Cluster fleet, configured into a constellation of large size (~ 8000 to 25 000 km spacecraft separation, allows us to observe wide-banded NTC waves at different distances from their sources. Two new findings can be derived from our analysis. First, we point out that a large portion of the plasmasphere boundary layer, covering a large range of magnetic

  13. Observation of large photonic band gaps and defect modes in one-dimensional networked waveguides

    CERN Document Server

    Mir, A; Vasseur, J O; Djafari-Rouhani, B; Fettouhi, N; Boudouti, E H E; Dobrzynski, L; Zemmouri, J

    2003-01-01

    The photonic band structures and transmission spectra of serial loop structures (SLSs), made of loops pasted together with segments of finite length, are investigated experimentally and theoretically. These monomode structures, composed of one-dimensional dielectric materials, may exhibit large stop bands where the propagation of electromagnetic waves is forbidden. The width of these band gaps depends on the geometrical and compositional parameters of the structure and may be drastically increased in a tandem geometry made up of several successive SLSs which differ in their physical characteristics. These SLSs may have potential applications as ultrawide-band filters.

  14. Observations of copolar correlation coefficient through a bright band at vertical incidence

    Science.gov (United States)

    Zrnic, D. S.; Raghavan, R.; Chandrasekar, V.

    1994-01-01

    This paper discusses an application of polarimetric measurements at vertical incidence. In particular, the correlation coefficients between linear copolar components are examined, and measurements obtained with the National Severe Storms Laboratory (NSSL)'s and National Center for Atmospheric Research (NCAR)'s polarimetric radars are presented. The data are from two well-defined bright bands. A sharp decrease of the correlation coefficient, confined to a height interval of a few hundred meters, marks the bottom of the bright band.

  15. Correlations between Strong Range Spread-F and GPS L-Band Scintillations Observed in Hainan in 2004

    International Nuclear Information System (INIS)

    Guo-Jun, Wang; Jian-Kui, Shi; She-Ping, Shang; Xiao, Wang

    2009-01-01

    Data from the DPS-4 digisonde and the GPS L-band ionospheric scintillation monitor are employed to study the correlations between strong range spread-F (SSF) and GPS L-band scintillations observed in the ionosphere over Hainan Island, China (19.5°N, 109.1°E geogr., dip lat. 9°N) in 2004. The SSF in the ionogram is different from the general range spread-F because it extends in frequency well beyond FoF2 and makes FoF2 difficult to be determined. The observations show that the SSF phenomenon is frequently accompanied by the occurrence of GPS L-band scintillations. The SSF and GPS L-band scintillations occur frequently in the equinoctial months (March, April, September, and October), but rarely in the winter (January, February, November, and December) and summer (May–August); especially, occurrence variations of the SSF and GPS L-band scintillations nearly have a same trend. The SSF and scintillations may be associated with the occurrence of topside plasma bubbles and could be explained by the generalized Rayleigh–Taylor instability

  16. Modeling L-band synthetic aperture radar observations through dielectric changes in soil moisture and vegetation over shrublands

    Science.gov (United States)

    L-band airborne synthetic aperture radar observations were made over California shrublands to better understand the effects by soil and vegetation parameters on backscatter. Temporal changes in radar backscattering coefficient (s0) of up to 3 dB were highly correlated to surface soil moisture but no...

  17. VizieR Online Data Catalog: TrES-2b multi-band transit observations (Mislis+, 2010)

    Science.gov (United States)

    Mislis, D.; Schroeter, S.; Schmitt, J. H. M. M.; Cordes, O.; Reif, K.

    2010-02-01

    The OLT data were taken on 11 April 2009 using a 3Kx3K CCD with a 1x1 FOV and an I-band filter as in our previous observing run (Paper I, Mislis & Schmitt, 2009, Cat. ). The Calar Alto data were taken on 28 May 2009 using BUSCA and the 2.2m telescope. (1 data file).

  18. Observations of magnetospheric ionization enhancements using upper-hybrid resonance noise band data from the RAE-1 satellite

    Science.gov (United States)

    Mosier, S. R.

    1975-01-01

    Noise bands associated with the upper-hybrid resonance were used to provide direct evidence for the existence of regions of enhanced density in the equatorial magnetosphere near L = 2. Density enhancements ranging from several percent to as high as 45 percent are observed with radial dimensions of several hundred kilometers. The enhancement characteristics strongly suggest their identification as magnetospheric whistler ducts.

  19. Uncertainty quantification of GEOS-5 L-band radiative transfer model parameters using Bayesian inference and SMOS observations

    NARCIS (Netherlands)

    De Lannoy, G.J.M.; Reichle, R.H.; Vrugt, J.A.

    2014-01-01

    Uncertainties in L-band (1.4 GHz) microwave radiative transfer modeling (RTM) affect the simulation of brightness temperatures (Tb) over land and the inversion of satellite-observed Tb into soil moisture retrievals. In particular, accurate estimates of the microwave soil roughness, vegetation

  20. First observation of yrast band in odd-odd 162Lu

    International Nuclear Information System (INIS)

    Zhang, Y.H.; Yuan, G.J.; Liu, X.A.

    1996-01-01

    High spin states of the odd-odd 162 Lu nucleus have been studied via 147 Sm( 19 F, 4nγ) 162 Lu reaction at 95MeV beam energy. Level scheme for yrast band based on π[h 11/2 ] υ[i 13/2 ] quasiparticle configuration was established up to I π =(23 - ) for the first time. This band shows the signature inversion in energy before backbending generally appeared in this mass region. It is stressed that the signature splitting in 162 Lu is larger than that in the 160 Tm nucleus. (orig.)

  1. Experimental observation of G banding verifying X-ray workers' chromosome translocation detected by FISH

    International Nuclear Information System (INIS)

    Sun Yuanming; Li Jin; Wang Qin; Tang Weisheng; Wang Zhiquan

    2002-01-01

    Objective: FISH is the most effective way of detecting chromosome aberration and many factors affect its accuracy. G-banding is used to verify the results of early X-ray workers' chromosome translocation examined by FISH. Methods: The chromosome translocations of early X-ray workers have been analysed by FISH (fluorescence in situ hybridization) and G-banding, yields of translocation treated with statistics. Results: The chromosome aberrations frequencies by tow methods are closely related. Conclusion: FISH is a feasible way to analyse chromosome aberrations of X-ray workers and reconstruct dose

  2. CAROLS: A New Airborne L-Band Radiometer for Ocean Surface and Land Observations

    DEFF Research Database (Denmark)

    Zribi, Mehrez; Parde, Mickael; Boutin, Jacquline

    2011-01-01

    The "Cooperative Airborne Radiometer for Ocean and Land Studies" (CAROLS) L-Band radiometer was designed and built as a copy of the EMIRAD II radiometer constructed by the Technical University of Denmark team. It is a fully polarimetric and direct sampling correlation radiometer. It is installed ...

  3. Polarimetric C-Band SAR Observations of Sea Ice in the Greenland Sea

    DEFF Research Database (Denmark)

    Thomsen, Bjørn Bavnehøj; Nghiem, S.V.; Kwok, R.

    1998-01-01

    The fully polarimetric EMISAR acquired C-band radar signatures of sea ice in the Greenland Sea during a campaign in March 1995. The authors present maps of polarimetric signatures over an area containing various kinds of ice and discuss the use of polarimetric SAR for identification of ice types...

  4. Observations of Multi-band Structures in Double Star TC-1 PEACE Electron and HIA Ion Data

    Science.gov (United States)

    Mohan Narasimhan, K.; Fazakerley, A. N.; Grimald, S.; Dandouras, I. S.; Mihaljcic, B.; Kistler, L. M.; Owen, C. J.

    2015-12-01

    Several authors have reported inner magnetosphere observations of proton distributions confined to narrow energy bands in the range 1 - 25 keV (Smith and Hoffman (1974), etc). These structures have been described as "nose structures", with reference to their appearance in energy-time spectrograms and are also known as "bands" if they occur for extended periods of time. Multi-nose structures have been observed if 2 or more noses appear at the same time (Vallat et al., 2007). Gaps between "noses" (or "bands") have been explained in terms of the competing corotation, convection and magnetic gradient drifts. Charge exchange losses in slow drift paths for steady state scenarios and the role of substorm injections have also been considered (Li et al., 2000; Ebihara et al., 2004). We analyse observations of electron and ion multi-band structures frequently seen in Double-Star TC1 PEACE and HIA data. We present results from statistical surveys conducted using data from the duration of the mission. Furthermore, using a combination of both statistics and simulations, we test previous theories as to possible formation mechanisms and explore other possible explanations.

  5. Comparing and Merging Observation Data from Ka-Band Cloud Radar, C-Band Frequency-Modulated Continuous Wave Radar and Ceilometer Systems

    Directory of Open Access Journals (Sweden)

    Liping Liu

    2017-12-01

    Full Text Available Field experiment in South China was undertaken to improve understanding of cloud and precipitation properties. Measurements of the vertical structures of non-precipitating and precipitating clouds were obtained using passive and active remote sensing equipment: a Ka-band cloud radar (CR system, a C-band frequency modulated continuous wave vertical pointing radar (CVPR, a microwave radiometer and a laser ceilometer (CEIL. CR plays a key role in high-level cloud observation, whereas CVPR is important for observing low- and mid-level clouds and heavy precipitation. CEIL helps us diminish the effects of “clear-sky” in the planetary boundary layer. The experiment took place in Longmen, Guangdong Province, China from May to September of 2016. This study focuses on evaluating the ability of the two radars to deliver consistent observation data and develops an algorithm to merge the CR, CVPR and CEIL data. Cloud echo base, thickness, frequency of observed cloud types and reflectivity vertical distributions are analyzed in the radar data. Comparisons between the collocated data sets show that reflectivity biases between the CR three operating modes are less than 2 dB. The averaged difference between CR and CVPR reflectivity can be reduced with attenuation correction to 3.57 dB from the original 4.82 dB. No systemic biases were observed between velocity data collected in the three CR modes and CVPR. The corrected CR reflectivity and velocity data were then merged with the CVPR data and CEIL data to fill in the gaps during the heavy precipitation periods and reduce the effects of Bragg scattering and fog on cloud observations in the boundary layer. Meanwhile, the merging of velocity data with different Nyquist velocities and resolutions diminishes velocity folding to provide fine-grain information about cloud and precipitation dynamics. The three daily periods in which low-level clouds tended to occur were at sunrise, noon and sunset and large

  6. In-Sample Confidence Bands and Out-of-Sample Forecast Bands for Time-Varying Parameters in Observation Driven Models

    NARCIS (Netherlands)

    Blasques, F.; Koopman, S.J.; Lasak, K.A.; Lucas, A.

    2016-01-01

    We study the performances of alternative methods for calculating in-sample confidence and out-of-sample forecast bands for time-varying parameters. The in-sample bands reflect parameter uncertainty, while the out-of-sample bands reflect not only parameter uncertainty, but also innovation

  7. Dynamics of isolated magnetic bright points derived from Hinode/SOT G-band observations

    Science.gov (United States)

    Utz, D.; Hanslmeier, A.; Muller, R.; Veronig, A.; Rybák, J.; Muthsam, H.

    2010-02-01

    Context. Small-scale magnetic fields in the solar photosphere can be identified in high-resolution magnetograms or in the G-band as magnetic bright points (MBPs). Rapid motions of these fields can cause magneto-hydrodynamical waves and can also lead to nanoflares by magnetic field braiding and twisting. The MBP velocity distribution is a crucial parameter for estimating the amplitudes of those waves and the amount of energy they can contribute to coronal heating. Aims: The velocity and lifetime distributions of MBPs are derived from solar G-band images of a quiet sun region acquired by the Hinode/SOT instrument with different temporal and spatial sampling rates. Methods: We developed an automatic segmentation, identification and tracking algorithm to analyse G-Band image sequences to obtain the lifetime and velocity distributions of MBPs. The influence of temporal/spatial sampling rates on these distributions is studied and used to correct the obtained lifetimes and velocity distributions for these digitalisation effects. Results: After the correction of algorithm effects, we obtained a mean MBP lifetime of (2.50 ± 0.05) min and mean MBP velocities, depending on smoothing processes, in the range of (1-2) km~s-1. Corrected for temporal sampling effects, we obtained for the effective velocity distribution a Rayleigh function with a coefficient of (1.62 ± 0.05) km~s-1. The x- and y-components of the velocity distributions are Gaussians. The lifetime distribution can be fitted by an exponential function.

  8. Observation of intermediate bands in Eu3+ doped YPO4 host: Li+ ion effect and blue to pink light emitter

    Directory of Open Access Journals (Sweden)

    Abdul Kareem Parchur

    2012-09-01

    Full Text Available This article explores the tuning of blue to pink colour generation from Li+ ion co-doped YPO4:5Eu nanoparticles prepared by polyol method at ∼100-120 °C with ethylene glycol (EG as a capping agent. Interaction of EG molecules capped on the surface of the nanoparticles and/or created oxygen vacancies induces formation of intermediate/mid gap bands in the host structure, which is supported by UV-Visible absorption data. Strong blue and pink colors can be observed in the cases of as-prepared and 500 °C annealed samples, respectively. Co-doping of Li+ enhances the emission intensities of intermediate band as well as Eu3+. On annealing as-prepared sample to 500 °C, the intermediate band emission intensity decreases, whereas Eu3+ emission intensity increases suggesting increase of extent of energy transfer from the intermediate band to Eu3+ on annealing. Emission intensity ratio of electric to magnetic dipole transitions of Eu3+ can be varied by changing excitation wavelength. The X-ray photoelectron spectroscopy (XPS study of as-prepared samples confirms the presence of oxygen vacancies and Eu3+ but absence of Eu2+. Dispersed particles in ethanol and polymer film show the strong blue color, suggesting that these materials will be useful as probes in life science and also in light emitting device applications.

  9. Partially Observable Markov Decision Process-Based Transmission Policy over Ka-Band Channels for Space Information Networks

    Directory of Open Access Journals (Sweden)

    Jian Jiao

    2017-09-01

    Full Text Available The Ka-band and higher Q/V band channels can provide an appealing capacity for the future deep-space communications and Space Information Networks (SIN, which are viewed as a primary solution to satisfy the increasing demands for high data rate services. However, Ka-band channel is much more sensitive to the weather conditions than the conventional communication channels. Moreover, due to the huge distance and long propagation delay in SINs, the transmitter can only obtain delayed Channel State Information (CSI from feedback. In this paper, the noise temperature of time-varying rain attenuation at Ka-band channels is modeled to a two-state Gilbert–Elliot channel, to capture the channel capacity that randomly ranging from good to bad state. An optimal transmission scheme based on Partially Observable Markov Decision Processes (POMDP is proposed, and the key thresholds for selecting the optimal transmission method in the SIN communications are derived. Simulation results show that our proposed scheme can effectively improve the throughput.

  10. Oil Slick Observation at Low Incidence Angles in Ku-Band

    Science.gov (United States)

    Panfilova, M. A.; Karaev, V. Y.; Guo, Jie

    2018-03-01

    On the 20 April 2010 the oil platform Deep Water Horizon in the Gulf of Mexico suffered an explosion during the final phases of drilling an exploratory well. As a result, an oil film covered the sea surface area of several thousand square kilometers. In the present paper the data of the Ku-band Precipitation Radar, which operates at low incidence angles, were used to explore the oil spill event. The two-scale model of the scattering surface was used to describe radar backscatter from the sea surface. The algorithm for retrieval of normalized radar cross section at nadir and the total slope variance of large-scale waves compared to the wavelength of electromagnetic wave (22 mm) was developed for the Precipitation Radar swath. It is shown that measurements at low incidence angles can be used for oil spill detection. This is the first time that the dependence of mean square slope of large-scale waves on wind speed has been obtained for oil slicks from Ku-band data, and compared to mean square slope obtained by Cox and Munk from optical data.

  11. CAROLS: A New Airborne L-Band Radiometer for Ocean Surface and Land Observations

    Directory of Open Access Journals (Sweden)

    Ernesto Lopez-Baeza

    2011-01-01

    Full Text Available The “Cooperative Airborne Radiometer for Ocean and Land Studies” (CAROLS L-Band radiometer was designed and built as a copy of the EMIRAD II radiometer constructed by the Technical University of Denmark team. It is a fully polarimetric and direct sampling correlation radiometer. It is installed on board a dedicated French ATR42 research aircraft, in conjunction with other airborne instruments (C-Band scatterometer—STORM, the GOLD-RTR GPS system, the infrared CIMEL radiometer and a visible wavelength camera. Following initial laboratory qualifications, three airborne campaigns involving 21 flights were carried out over South West France, the Valencia site and the Bay of Biscay (Atlantic Ocean in 2007, 2008 and 2009, in coordination with in situ field campaigns. In order to validate the CAROLS data, various aircraft flight patterns and maneuvers were implemented, including straight horizontal flights, circular flights, wing and nose wags over the ocean. Analysis of the first two campaigns in 2007 and 2008 leads us to improve the CAROLS radiometer regarding isolation between channels and filter bandwidth. After implementation of these improvements, results show that the instrument is conforming to specification and is a useful tool for Soil Moisture and Ocean Salinity (SMOS satellite validation as well as for specific studies on surface soil moisture or ocean salinity.

  12. The first observations of wide-band interferometers and the spectra of relic gravitons

    CERN Document Server

    Giovannini, Massimo

    2016-01-01

    Stochastic backgrounds of relic gravitons of cosmological origin extend from frequencies of the order of the aHz up to the GHz range. Since the temperature and polarization anisotropies constrain the low frequency normalization of the spectra, in the concordance paradigm the strain amplitude corresponding to the frequency window of wide-band interferometers turns out to be, approximately, nine orders of magnitude smaller than the astounding signal recently reported and attributed to a binary black hole merger. The backgrounds of relic gravitons expected from the early Universe are compared with the stochastic foregrounds stemming from the estimated multiplicity of the astrophysical sources. It is suggested that while the astrophysical foregrounds are likely to dominate between few Hz and 10 kHz, relic gravitons with frequencies exceeding 100 kHz represent a potentially uncontaminated signal for the next generation of high-frequency detectors currently under scrutiny.

  13. Partner bands of 126Cs - first observation of chiral electromagnetic selection rules

    International Nuclear Information System (INIS)

    Grodner, E.; Sankowska, I.; Morek, T.; Rohozinski, S.G.; Droste, Ch.; Srebrny, J.; Pasternak, A.A.; Kisielinski, M.; Kowalczyk, M.; Kownacki, J.; Mierzejewski, J.; Krol, A.

    2011-01-01

    The lifetimes of the excited states belonging to the chiral partner bands built on the πh 11/2 xνh 11/2 -1 configuration in 126 Cs have been measured using the DSA technique. For the first time the large set of the experimental transition probabilities is in qualitative agreement with all selection rules predicted for the strong chiral symmetry breaking limit. The selection rules originate from two general features of a chiral nucleus, namely, from the existence of well separated left- and right-handed systems built of three angular momentum vectors and extra symmetries appearing in addition to the chiral symmetry breaking. The B(M1) staggering resulting from these additional symmetries is sensitive to triaxiality of odd-odd nuclei as well as configuration of valence particles.

  14. PAHs and the Diffuse Interstellar Bands. What have we Learned from the New Generation of Laboratory and Observational Studies?

    Science.gov (United States)

    Salama, Farid

    2005-01-01

    Polycyclic Aromatic Hydrocarbons (PAHs) are an important and ubiquitous component of carbon-bearing materials in space. PAHs are the best-known candidates to account for the IR emission bands (UIR bands) and PAH spectral features are now being used as new probes of the ISM. PAHs are also thought to be among the carriers of the diffuse interstellar absorption bands (DIBs). In the model dealing with the interstellar spectral features, PAHs are present as a mixture of radicals, ions and neutral species. PAH ionization states reflect the ionization balance of the medium while PAH size, composition, and structure reflect the energetic and chemical history of the medium. A major challenge for laboratory astrophysics is to reproduce (in a realistic way) the physical conditions that exist in the emission and/or absorption interstellar zones, An extensive laboratory program has been developed at NASA Ames to characterize the physical and chemical properties of PAHs in astrophysical environments and to describe how they influence the radiation and energy balance in space and the interstellar chemistry. In particular, laboratory experiments provide measurements of the spectral characteristics of interstellar PAH analogs from the ultraviolet and visible range to the infrared range for comparison with astronomical data. This paper will focus on the recent progress made in the laboratory to measure the direct absorption spectra of neutral and ionized PAHs in the gas phase in the near-W and visible range in astrophysically relevant environments. These measurements provide data on PAHs and nanometer-sized particles that can now be directly compared to astronomical observations. The harsh physical conditions of the IS medium - characterized by a low temperature, an absence of collisions and strong V W radiation fields - are simulated in the laboratory by associating a molecular beam with an ionizing discharge to generate a cold plasma expansion. PAH ions are formed from the neutral

  15. Theoretical study of electronic absorption spectroscopy of propadienylidene molecule vis-â-vis the observed diffuse interstellar bands

    International Nuclear Information System (INIS)

    Reddy, Samala Nagaprasad; Mahapatra, S.

    2012-01-01

    Highlights: ► Theoretical study of spectroscopy and dynamics of electronically excited l-C 3 H 2 . ► Construction of ab initio electronic potential energy and diabatic coupling surfaces. ► First principles study of nuclear dynamics on excited electronic states. ► Findings reveal l-C 3 H 2 is a potential molecular carrier of diffuse interstellar bands. ► Electronically excited l-C 3 H 2 decays by ultrafast nonradiative internal conversion. -- Abstract: Observation of broad and diffuse interstellar bands (DIBs) at 4881 Å and 5440 Å assigned to the optical absorption spectrum of Y-shaped propadienylidene (H 2 C=C=C:) molecule is theoretically examined in this paper. This molecule apparently absorbs in the same wavelength region as the observed DIBs and was suggested to be a potential carrier of these DIBs. This assignment mostly relied on the experimental data from radioastronomy and laboratory measurements. Motivated by these available experimental data we attempt here a theoretical study and investigate the detailed electronic structure and nuclear dynamics underlying the electronic absorption bands of propadienylidene molecule. Our results show that this molecule indeed absorbs in the wavelength region of the recorded DIBs. Strong nonadiabatic coupling between its energetically low-lying electronic states plays major role, initiates ultrafast internal conversion and contributes to the spectral broadening. Theoretical findings are finally compared with the available experimental and theoretical data and discussed in connection with the recorded DIBs.

  16. Broad Band Observations of Gravitationally Lensed Blazar during a Gamma-Ray Outburst

    Directory of Open Access Journals (Sweden)

    Julian Sitarek

    2016-09-01

    Full Text Available QSO B0218+357 is a gravitationally lensed blazar located at a cosmological redshift of 0.944. In July 2014 a GeV flare was observed by Fermi-LAT, triggering follow-up observations with the MAGIC telescopes at energies above 100 GeV. The MAGIC observations at the expected time of arrival of the trailing component resulted in the first detection of QSO B0218+357 in Very-High-Energy (VHE, >100 GeV gamma rays. We report here the observed multiwavelength emission during the 2014 flare.

  17. Possibilities of the observation of the discrete spectrum of the water dimer at equilibrium in millimeter-wave band

    International Nuclear Information System (INIS)

    Krupnov, A.F.; Tretyakov, M.Yu.; Leforestier, C.

    2009-01-01

    Attempts of experimental observations of the water dimer spectrum at equilibrium conditions have lasted for more than 40 years since the dimeric hypothesis for extra absorption, but have not yielded any positive confirmed result. In the present paper a new approach is considered: using a high-resolution millimeter-wave spectrum of the water dimer at equilibrium, calculated by a rigorous fully quantum method, we show the potential existence of discernible spectral series of discrete features of the water dimer, which correspond to J+1 1 symmetry, already observed in cold molecular beam experiments and having, therefore, well-defined positions. The intensity of spectral series and contrast to the remaining continuum-like spectrum of the dimer are calculated and compared with the monomer absorption. The suitability of two types of microwave spectrometers for observing these series is considered. The collisional line-width of millimeter lines of the dimer at equilibrium is estimated and the width of IR dimer bands is discussed. It is pointed out that the large width of IR dimer bands may pose difficulties for their reliable observation and conclusive separation from the rest of absorption in water vapor. This situation contrasts with the suggested approach of dimer detection in millimeter-waves.

  18. Near-infrared Spectroscopic Observations of Comet C/2013 R1 (Lovejoy) by WINERED: CN Red-system Band Emission

    Energy Technology Data Exchange (ETDEWEB)

    Shinnaka, Yoshiharu; Yasui, Chikako; Izumi, Natsuko [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Kawakita, Hideyo; Kondo, Sohei; Ikeda, Yuji; Kobayashi, Naoto; Hamano, Satoshi; Sameshima, Hiroaki; Fukue, Kei; Matsunaga, Noriyuki; Otsubo, Shogo; Takenaka, Keiichi; Watase, Ayaka; Kawanishi, Takafumi; Nakanishi, Kenshi; Nakaoka, Tetsuya [Laboratory of Infrared High-resolution Spectroscopy, Koyama Astronomical Observatory, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto 603-8555 (Japan); Mizumoto, Misaki, E-mail: yoshiharu.shinnaka@nao.ac.jp, E-mail: kawakthd@cc.kyoto-su.ac.jp [Department of Astronomy, School of Science, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2017-08-01

    Although high-resolution spectra of the CN red-system band are considered useful in cometary sciences, e.g., in the study of isotopic ratios of carbon and nitrogen in cometary volatiles, there have been few reports to date due to the lack of high-resolution ( R  ≡  λ /Δ λ  > 20,000) spectrographs in the near-infrared region around ∼1 μ m. Here, we present the high-resolution emission spectrum of the CN red-system band in comet C/2013 R1 (Lovejoy), acquired by the near-infrared high-resolution spectrograph WINERED mounted on the 1.3 m Araki telescope at the Koyama Astronomical Observatory, Kyoto, Japan. We applied our fluorescence excitation models for CN, based on modern spectroscopic studies, to the observed spectrum of comet C/2013 R1 (Lovejoy) to search for CN isotopologues ({sup 13}C{sup 14}N and {sup 12}C{sup 15}N). We used a CN fluorescence excitation model involving both a “pure” fluorescence excitation model for the outer coma and a “fully collisional” fluorescence excitation model for the inner coma region. Our emission model could reproduce the observed {sup 12}C{sup 14}N red-system band of comet C/2013 R1 (Lovejoy). The derived mixing ratio between the two excitation models was 0.94(+0.02/−0.03):0.06(+0.03/−0.02), corresponding to the radius of the collision-dominant region of ∼800–1600 km from the nucleus. No isotopologues were detected. The observed spectrum is consistent, within error, with previous estimates in comets of {sup 12}C/{sup 13}C (∼90) and {sup 14}N/{sup 15}N (∼150).

  19. Optical Observations of M81 Galaxy Group in Narrow Band [SII] and H_alpha Filters: Holmberg IX

    Directory of Open Access Journals (Sweden)

    Arbutina, B.

    2009-12-01

    Full Text Available We present observations of the nearby tidal dwarf galaxy Holmberg IX in M81 galaxy group in narrow band [SII] and H$alpha$ filters, carried out in March and November 2008 with the 2m RCC telescope at NAO Rozhen, Bulgaria. Our search for resident supernova remnants (identified as sources with enhanced [SII] emission relative to their H$alpha$ emission in this galaxy yielded no sources of this kind, besides M&H 10-11 or HoIX X-1. Nevertheless, we found a number of objects with significant H$alpha$ emission that probably represent uncatalogued HII regions.

  20. Spectroscopy of 9Be and observation of neutron halo structure in the states of positive parity rotational band

    Directory of Open Access Journals (Sweden)

    Demyanova A.S.

    2014-03-01

    Full Text Available The differential cross sections of the 9Be + α inelastic scattering at 30 MeV were measured at the tandem of Tsukuba University. All the known states of 9Be up to energies ~ 12 MeV were observed and decomposed into three rotational bands, each of them having a cluster structure consisting of a 8Be core plus a valence neutron in one of the sub-shells: p3/2−, s1/2+ and p1/2−. Existence of a neutron halo in the positive parity states was confirmed.

  1. Revealing the Faraday depth structure of radio galaxy NGC 612 with broad-band radio polarimetric observations

    Science.gov (United States)

    Kaczmarek, J. F.; Purcell, C. R.; Gaensler, B. M.; Sun, X.; O'Sullivan, S. P.; McClure-Griffiths, N. M.

    2018-05-01

    We present full-polarization, broad-band observations of the radio galaxy NGC 612 (PKS B0131-637) from 1.3 to 3.1 GHz using the Australia Telescope Compact Array. The relatively large angular scale of the radio galaxy makes it a good candidate with which to investigate the polarization mechanisms responsible for the observed Faraday depth structure. By fitting complex polarization models to the polarized spectrum of each pixel, we find that a single polarization component can adequately describe the observed signal for the majority of the radio galaxy. While we cannot definitively rule out internal Faraday rotation, we argue that the bulk of the Faraday rotation is taking place in a thin skin that girts the polarized emission. Using minimum energy estimates, we find an implied total magnetic field strength of 4.2 μG.

  2. Observation of solar radio bursts using swept-frequency radiospectrograph in 20 - 40 MHz band

    International Nuclear Information System (INIS)

    Aoyama, Takashi; Oya, Hiroshi.

    1987-01-01

    A new station for the observation of solar decametric radio bursts has been developed at Miyagi Vocational Training College in Tsukidate, Miyagi, Japan. Using the swept frequency radiospectrograph covering a frequency range from 20 MHz to 40 MHz within 200 msec, with bandwidth of 30 kHz, the radio outbursts from the sun have been currently monitored with colored dynamic spectrum display. After July 1982, successful observations provide the data which include all types of solar radio bursts such as type I, II, III, IV and V in the decametric wavelength range. In addition to these typical radio bursts, rising tone bursts with fast drift rate followed by strong type III bursts and a series of bursts repeating rising and falling tone bursts with slow drift rate have been observed. (author)

  3. Observations of Terrestrial Nightglow (Meinel Bands at King Sejong Station, Antarctica

    Directory of Open Access Journals (Sweden)

    Young-In Won

    1999-12-01

    Full Text Available A Fourier Transform Spectrometer was used to study upper mesospheric thermodynamic by observing the hydroxyl (OH emission. Rocket-born and satellited-born photometers place the peak emission near 87 km. The instrument was installed in February 1999 at King Sejong station (62.22 °S, 301.25 °E, Antarctica and has been in routine operation since then. An intensive operational effort has resulted in a substantial data between April and June, 1999. A harmonic analysis was carried out to examine information on the tidal characteristics. The measured amplitudes of the 12-hour oscillation are in the range of 2.4-3.7 K, which are in resonable agreement with theoretical model outputs. The harmonic analysis also revealed 8-hour oscillation which is not expected from the traditional theoretical studies. In addition, the observed 8-hour oscillations are apparent and sometimes dominate the temperature variation in the upper mesosphere.

  4. Characterization of VHF radar observations associated with equatorial Spread F by narrow-band optical measurements

    Directory of Open Access Journals (Sweden)

    R. Sekar

    2004-09-01

    Full Text Available The VHF radars have been extensively used to investigate the structures and dynamics of equatorial Spread F (ESF irregularities. However, unambiguous identification of the nature of the structures in terms of plasma depletion or enhancement requires another technique, as the return echo measured by VHF radar is proportional to the square of the electron density fluctuations. In order to address this issue, co-ordinated radar backscatter and thermospheric airglow intensity measurements were carried out during March 2003 from the MST radar site at Gadanki. Temporal variations of 630.0-nm and 777.4-nm emission intensities reveal small-scale ("micro" and large-scale ("macro" variations during the period of observation. The micro variations are absent on non-ESF nights while the macro variations are present on both ESF and non-ESF nights. In addition to the well-known anti-correlation between the base height of the F-region and the nocturnal variation of thermospheric airglow intensities, the variation of the base height of the F-layer, on occasion, is found to manifest as a bottomside wave-like structure, as seen by VHF radar on an ESF night. The micro variations in the airglow intensities are associated with large-scale irregular plasma structures and found to be in correspondence with the "plume" structures obtained by VHF radar. In addition to the commonly observed depletions with upward movement, the observation unequivocally reveals the presence of plasma enhancements which move downwards. The observation of enhancement in 777.4-nm airglow intensity, which is characterized as plasma enhancement, provides an experimental verification of the earlier prediction based on numerical modeling studies.

  5. Atmospheric monitoring in the millimetre and submillimetre bands for cosmological observations: CASPER2

    Science.gov (United States)

    De Petris, M.; De Gregori, S.; Decina, B.; Lamagna, L.; Pardo, J. R.

    2013-02-01

    Cosmological observations from ground at millimetre and submillimetre wavelengths are affected by atmospheric absorption and consequent emission. The low- and high-frequency (sky-noise) fluctuations of atmospheric performance necessitate careful observational strategies and/or instrumental technical solutions. Measurements of atmospheric emission spectra are necessary for accurate calibration procedures as well as for site-testing statistics. CASPER2, an instrument designed to explore the 90-450 GHz (3-15 cm-1) spectral region, was developed and had its operation verified in the Alps. A Martin-Puplett interferometer (MPI) operates by comparing sky radiation, coming from a field of view (FOV) of 28 arcmin (full width at half-maximum) and collected by a 62-cm-diameter Pressman-Camichel telescope, with a reference source. The signals at the two output ports of the interferometer are detected by two bolometers cooled to 300 mK inside a wet cryostat. Three different but complementary interferometric techniques can be performed with CASPER2: amplitude modulation (AM), fast-scan (FS) and phase modulation (PM). An altazimuthal mount allows sky pointing, possibly co-aligned with the optical axis of the 2.6-m-diameter telescope of MITO (Millimetre and Infrared Testagrigia Observatory, Italy). The optimal time-scale to average acquired spectra is inferred by Allan variance analysis at five fiducial frequencies. We present the motivation for and design of the atmospheric spectrometer CASPER2. The procedure adopted to calibrate the instrument and the preliminary performance of it are described. Instrument capabilities were checked during the summer observational campaign at MITO in 2010 July by measuring atmospheric emission spectra with the three procedures.

  6. Observations of Terrestrial Nightglow (Meinel Bands) at King Sejong Station, Antarctica

    OpenAIRE

    Young-In Won; Young-Mon Cho; Bang Yong Lee; Jhoon Kim; Jong Kyun Chung; Yong Ha Kim

    1999-01-01

    A Fourier Transform Spectrometer was used to study upper mesospheric thermodynamic by observing the hydroxyl (OH) emission. Rocket-born and satellited-born photometers place the peak emission near 87 km. The instrument was installed in February 1999 at King Sejong station (62.22 °S, 301.25 °E), Antarctica and has been in routine operation since then. An intensive operational effort has resulted in a substantial data between April and June, 1999. A harmonic analysis was carried out to examine ...

  7. Observation of Whole Flushing Process of a River Sand Bar by a Flood Using X-Band Radar

    Directory of Open Access Journals (Sweden)

    Satoshi Takewaka

    2016-05-01

    Full Text Available Morphological changes during a flood event in July 2010 were observed with X-band marine radar at the mouth of Tenryu River, Shizuoka, Japan. Radar images were collected hourly for more than 72 h from the beginning of the flood and processed into time-averaged images. Changes in the morphology of the area were interpreted from the time-averaged images, revealing that the isolated river dune was washed away by the flood, the width of the river mouth increased gradually, and the river mouth terrace expanded radially. Furthermore, image analysis of the radar images was applied to estimate the migration speed of the brightness pattern, which is assumed to be a proxy of bottom undulation of the river bed. The migration was observed to be faster when the water level gradient between the river channel and sea increased.

  8. Uncertainty Quantification of GEOS-5 L-band Radiative Transfer Model Parameters Using Bayesian Inference and SMOS Observations

    Science.gov (United States)

    DeLannoy, Gabrielle J. M.; Reichle, Rolf H.; Vrugt, Jasper A.

    2013-01-01

    Uncertainties in L-band (1.4 GHz) radiative transfer modeling (RTM) affect the simulation of brightness temperatures (Tb) over land and the inversion of satellite-observed Tb into soil moisture retrievals. In particular, accurate estimates of the microwave soil roughness, vegetation opacity and scattering albedo for large-scale applications are difficult to obtain from field studies and often lack an uncertainty estimate. Here, a Markov Chain Monte Carlo (MCMC) simulation method is used to determine satellite-scale estimates of RTM parameters and their posterior uncertainty by minimizing the misfit between long-term averages and standard deviations of simulated and observed Tb at a range of incidence angles, at horizontal and vertical polarization, and for morning and evening overpasses. Tb simulations are generated with the Goddard Earth Observing System (GEOS-5) and confronted with Tb observations from the Soil Moisture Ocean Salinity (SMOS) mission. The MCMC algorithm suggests that the relative uncertainty of the RTM parameter estimates is typically less than 25 of the maximum a posteriori density (MAP) parameter value. Furthermore, the actual root-mean-square-differences in long-term Tb averages and standard deviations are found consistent with the respective estimated total simulation and observation error standard deviations of m3.1K and s2.4K. It is also shown that the MAP parameter values estimated through MCMC simulation are in close agreement with those obtained with Particle Swarm Optimization (PSO).

  9. Observation of total electron content and irregularities in electron density using GHz band radiowaves emitted from satellite

    International Nuclear Information System (INIS)

    Ogawa, Tadahiko; Fujita, Masaharu; Awaka, Jun.

    1978-01-01

    The experiments to investigate the influence of troposphere on millimeter and sub-millimeter wave propagation were carried out, using the engineering test satellite -- 2 (ETS-2) which became the Japanese first stationary satellite and carries the transmitter emitting beacon waves of 1.7, 11.5 and 34.5 GHz coherent each other. By these experiments, it was found that the waves of 1.7 and 11.5 GHz were affected by the ionosphere. The measurement of total electron content using GHz band waves was the first trial in the world, and is capable of grasping its change with higher accuracy than conventional methods. Scintillation of 1.7 GHz is mainly the phenomenon during night, and it was revealed that it has a peak at 22.30 local time and occurred through the radiowave scattering owing to the irregularities of the ionosphere. It is also suggested that some plasma instability is generated in the place where electron density gradient in the ionosphere is large, and the irregularities of fine scale are produced, assuming from GHz band scintillations at the time of magnetic storm. The relations among wave number spectrum, scintillation frequency spectrum and S4 index (statistical quantity to give estimate for scintillation amplitude) can be derived by the weak scattering theory (Simple scattering theory). As seen above, the diagnosis of plasma disturbances in the ionosphere is feasible by the simultaneous observations of total electron content and scintillation. (Wakatsuki, Y.)

  10. Multi-wave band SMM-VLA observations of an M2 flare and an associated coronal mass ejection

    Science.gov (United States)

    Willson, Robert F.; Lang, Kenneth R.; Schmelz, Joan T.; Gonzalez, Raymond D.; Smith, Kermit L.

    1991-01-01

    Results are presented of observations of an M2 flare and an associated coronal mass ejection CME by instruments on the SMM as well as by the VLA and other ground-based observatories on September 30, 1988. The multiwave band data show a gradual slowly changing event which lasted several hours. The microwave burst emission was found to originate in compact moderately circularly polarized sources located near the sites of bright H-alpha and soft X-ray emission. These data are combined with estimates of an electron temperature of 1.5 x 10 to the 7th K and an emission measure of about 2.0 x 10 to the 49th/cu cm obtained from Ca XIX and Fe XXV spectra to show that the microwave emission can be attributed to thermal gyrosynchrotron radiation in regions where the magnetic field strength is 425-650 G. The CME acceleration at low altitudes is measured on the basis of ground- and space-based coronagraphs.

  11. FIRST L-BAND INTERFEROMETRIC OBSERVATIONS OF A YOUNG STELLAR OBJECT: PROBING THE CIRCUMSTELLAR ENVIRONMENT OF MWC 419

    International Nuclear Information System (INIS)

    Ragland, S.; Armandroff, T.; Wizinowich, P. L.; Akeson, R. L.; Millan-Gabet, R.; Colavita, M. M.; Traub, W. A.; Vasisht, G.; Danchi, W. C.; Hillenbrand, L. A.; Ridgway, S. T.

    2009-01-01

    We present spatially resolved K- and L-band spectra (at spectral resolution R = 230 and R = 60, respectively) of MWC 419, a Herbig Ae/Be star. The data were obtained simultaneously with a new configuration of the 85 m baseline Keck Interferometer. Our observations are sensitive to the radial distribution of temperature in the inner region of the disk of MWC 419. We fit the visibility data with both simple geometric and more physical disk models. The geometric models (uniform disk and Gaussian) show that the apparent size increases linearly with wavelength in the 2-4 μm wavelength region, suggesting that the disk is extended with a temperature gradient. A model having a power-law temperature gradient with radius simultaneously fits our interferometric measurements and the spectral energy distribution data from the literature. The slope of the power law is close to that expected from an optically thick disk. Our spectrally dispersed interferometric measurements include the Br γ emission line. The measured disk size at and around Br γ suggests that emitting hydrogen gas is located inside (or within the inner regions) of the dust disk.

  12. First L-Band Interferometric Observations of a Young Stellar Object: Probing the Circumstellar Environment of MWC 419

    Science.gov (United States)

    Ragland, S.; Akeson, R. L.; Armandroff, T.; Colavita, M. M.; Danchi, W. C.; Hillenbrand, L. A.; Millan-Gabet, R.; Ridgway, S. T.; Traub, W. A.; Vasisht, G.; Wizinowich, P. L.

    2009-09-01

    We present spatially resolved K- and L-band spectra (at spectral resolution R = 230 and R = 60, respectively) of MWC 419, a Herbig Ae/Be star. The data were obtained simultaneously with a new configuration of the 85 m baseline Keck Interferometer. Our observations are sensitive to the radial distribution of temperature in the inner region of the disk of MWC 419. We fit the visibility data with both simple geometric and more physical disk models. The geometric models (uniform disk and Gaussian) show that the apparent size increases linearly with wavelength in the 2-4 μm wavelength region, suggesting that the disk is extended with a temperature gradient. A model having a power-law temperature gradient with radius simultaneously fits our interferometric measurements and the spectral energy distribution data from the literature. The slope of the power law is close to that expected from an optically thick disk. Our spectrally dispersed interferometric measurements include the Br γ emission line. The measured disk size at and around Br γ suggests that emitting hydrogen gas is located inside (or within the inner regions) of the dust disk.

  13. Observations of a Cold Front at High Spatiotemporal Resolution Using an X-Band Phased Array Imaging Radar

    Directory of Open Access Journals (Sweden)

    Andrew Mahre

    2017-02-01

    Full Text Available While the vertical structure of cold fronts has been studied using various methods, previous research has shown that traditional methods of observing meteorological phenomena (such as pencil-beam radars in PPI/volumetric mode are not well-suited for resolving small-scale cold front phenomena, due to relatively low spatiotemporal resolution. Additionally, non-simultaneous elevation sampling within a vertical cross-section can lead to errors in analysis, as differential vertical advection cannot be distinguished from temporal evolution. In this study, a cold front from 19 September 2015 is analyzed using the Atmospheric Imaging Radar (AIR. The AIR transmits a 20-degree fan beam in elevation, and digital beamforming is used on receive to generate simultaneous receive beams. This mobile, X-band, phased-array radar offers temporal sampling on the order of 1 s (while in RHI mode, range sampling of 30 m (37.5 m native resolution, and continuous, arbitrarily oversampled data in the vertical dimension. Here, 0.5-degree sampling is used in elevation (1-degree native resolution. This study is the first in which a cold front has been studied via imaging radar. The ability of the AIR to obtain simultaneous RHIs at high temporal sampling rates without mechanical steering allows for analysis of features such as Kelvin-Helmholtz instabilities and feeder flow.

  14. Observation of a hidden hole-like band approaching the fermi level in K-doped iron selenide superconductor

    International Nuclear Information System (INIS)

    Sunagawa, Masanori; Terashima, Kensei; Hamada, Takahiro

    2016-01-01

    One of the ultimate goals of the study of iron-based superconductors is to identify the common feature that produces the high critical temperature (T c ). In the early days, based on a weak-coupling viewpoint, the nesting between hole- and electron-like Fermi surfaces (FSs) leading to the so-called s± state was considered to be one such key feature. However, this theory has faced a serious challenge ever since the discovery of alkali-metal-doped FeSe (AFS) superconductors, in which only electron-like FSs with a nodeless superconducting gap are observed. Several theories have been proposed, but a consistent understanding is yet to be achieved. Here we show experimentally that a hole-like band exists in K x Fe 2-y Se 2 , which presumably forms a hole-like Fermi surface. The present study suggests that AFS can be categorized in the same group as iron arsenides with both hole- and electron-like FSs present. This result provides a foundation for a comprehensive understanding of the superconductivity in iron-based superconductors. (author)

  15. Observation of an electron band above the Fermi level in FeTe0.55Se0.45 from in-situ surface doping

    International Nuclear Information System (INIS)

    Zhang, P.; Ma, J.; Qian, T.; Richard, P.; Ding, H.; Xu, N.; Xu, Y.-M.; Fedorov, A. V.; Denlinger, J. D.; Gu, G. D.

    2014-01-01

    We used in-situ potassium (K) evaporation to dope the surface of the iron-based superconductor FeTe 0.55 Se 0.45 . The systematic study of the bands near the Fermi level confirms that electrons are doped into the system, allowing us to tune the Fermi level of this material and to access otherwise unoccupied electronic states. In particular, we observe an electron band located above the Fermi level before doping that shares similarities with a small three-dimensional pocket observed in the cousin, heavily electron-doped KFe 2−x Se 2 compound.

  16. Simulation study for ground-based Ku-band microwave observations of ozone and hydroxyl in the polar middle atmosphere

    Science.gov (United States)

    Newnham, David; Clilverd, Mark; Kosch, Michael; Verronen, Pekka

    2017-04-01

    Commercial satellite TV broadcasting is possible due to remarkable advances in microwave electronics, enabling weak signals transmitted over 36,000 km from geostationary orbit to be received by inexpensive rooftop dishes. The Ku band satellite frequencies (10.70-14.25 GHz) overlap microwave emissions from ozone (O3) at 11.072 GHz and hydroxyl radical (OH) at 13.44 GHz. These important chemical species in the polar middle atmosphere respond strongly to solar variability and, at high latitudes, geomagnetic activity associated with space weather. Atmospheric model calculations predict that energetic electron precipitation (EEP) driven by magnetospheric substorms produces large changes in polar mesospheric O3 and OH. The EEP typically peaks at geomagnetic latitudes ˜65˚ (e.g. Kilpisjärvi, Finland and Syowa station, Antarctica) and evolves rapidly with time eastwards and over the geomagnetic latitude range 60˚ -80˚ (e.g. reaching Halley, Antarctica). During the substorms OH can increase by more than 1000% at 64-84 km. The substorms leave footprints of 5-55% O3 loss lasting many hours of local time, with strong altitude and seasonal dependences. An atmospheric simulation and retrieval study is performed to determine the specification and design requirements for microwave radiometers capable of measuring O3 and OH profiles from Arctic and Antarctic locations using accessible satellite TV receiver technology. The proposed observations are highly applicable to studies of EEP, atmospheric dynamics, planetaryscale circulation, chemical transport, and the representation of these processes in polar and global climate models. They would provide a lowcost, reliable alternative to increasingly sparse satellite measurements, extending long-term data records and also providing "ground truth" calibration data.

  17. Observation of states beyond band termination in 156,157,158Er and strongly deformed structures in 173,174,175Hf

    International Nuclear Information System (INIS)

    Riley, M A; Djongolov, M K; Evans, A O

    2006-01-01

    High-spin terminating bands in heavy nuclei were first identified in nuclei around 158 Er 90 . While examples of terminating states have been identified in a number of erbium isotopes, almost nothing is known about the states lying beyond band termination. In the present work, the high-spin structure of 156,157,158 Er has been studied using the Gammasphere spectrometer. The subject of triaxial superdeformation and 'wobbling' modes in Lu nuclei has rightly attracted a great deal of attention. Very recently four strongly or superdeformed (SD) sequences have been observed in 174 Hf, and cranking calculations using the Ultimate Cranker code predict that such structures may have significant triaxial deformation. We have performed two experiments in an attempt to verify the possible triaxial nature of these bands. A lifetime measurement was performed to confirm the large (and similar) deformation of the bands. In addition, a high-statistics, thin-target experiment took place to search for linking transitions between the SD bands, possible wobbling modes, and new SD band structures

  18. The broad-band X-ray spectrum of IC 4329A from a joint NuSTAR/Suzaku observation

    Energy Technology Data Exchange (ETDEWEB)

    Brenneman, L. W.; Elvis, M. [Harvard-Smithsonian CfA, 60 Garden St., MS-67, Cambridge, MA 02138 (United States); Madejski, G. [Kavli Institute for Particle Astrophysics and Cosmology, SLAC National Accelerator Laboratory, Menlo Park, CA 94025 (United States); Fuerst, F.; Harrison, F. A.; Grefenstette, B. W.; Madsen, K. K.; Rivers, E.; Walton, D. J. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, Pasadena, CA 91125 (United States); Matt, G.; Marinucci, A. [Dipartimento di Matematica e Fisica, Università Roma Tre, via della Vasca Navale 84, I-00146 Roma (Italy); Ballantyne, D. R. [Center for Relativistic Astrophysics, School of Physics, Georgia Institute of Technology, Atlanta, GA 30332 (United States); Boggs, S. E. [Space Science Laboratory, University of California, Berkeley, CA 94720 (United States); Christensen, F. E.; Craig, W. W. [DTU Space-National Space Institute, Technical University of Denmark, Elektrovej 327, DK-2800 Lyngby (Denmark); Fabian, A. C. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Hailey, C. J. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Stern, D. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Zhang, W. W. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2014-06-10

    We have obtained a deep, simultaneous observation of the bright, nearby Seyfert galaxy IC 4329A with Suzaku and NuSTAR. Through a detailed spectral analysis, we are able to robustly separate the continuum, absorption, and distant reflection components in the spectrum. The absorbing column is found to be modest (∼6×10{sup 21} cm{sup −2} ), and does not introduce any significant curvature in the Fe K band. We are able to place a strong constraint on the presence of a broadened Fe Kα line (E{sub rest}=6.46{sub −0.07}{sup +0.08} keV with σ=0.33{sub −0.07}{sup +0.08} keV and EW=34{sub −7}{sup +8} eV), though we are not able to constrain any of the parameters of a relativistic reflection model. These results highlight the range in broad Fe K line strengths observed in nearby, bright, active galactic nuclei (roughly an order of magnitude), and imply a corresponding range in the physical properties of the inner accretion disk in these sources. We have also updated our previously reported measurement of the high-energy cutoff of the hard X-ray emission using both observatories rather than just NuSTAR alone: E {sub cut} = 186 ± 14 keV. This high-energy cutoff acts as a proxy for the temperature of the coronal electron plasma, enabling us to further separate this parameter from the plasma's optical depth and to update our results for these parameters as well. We derive kT=50{sub −3}{sup +6} keV with τ=2.34{sub −0.11}{sup +0.16} using a spherical geometry, kT = 61 ± 1 keV with τ = 0.68 ± 0.02 for a slab geometry, with both having an equivalent goodness-of-fit.

  19. LOCAL BENCHMARKS FOR THE EVOLUTION OF MAJOR-MERGER GALAXIES-SPITZER OBSERVATIONS OF A K-BAND SELECTED SAMPLE

    International Nuclear Information System (INIS)

    Xu, C. Kevin; Cheng Yiwen; Lu Nanyao; Mazzarella, Joseph M.; Cutri, Roc; Domingue, Donovan; Huang Jiasheng; Gao Yu; Sun, W.-H.; Surace, Jason

    2010-01-01

    We present Spitzer observations for a sample of close major-merger galaxy pairs (KPAIR sample) selected from cross-matches between the Two Micron All Sky Survey and Sloan Digital Sky Survey Data Release 3. The goals are to study the star formation activity in these galaxies and to set a local bench mark for the cosmic evolution of close major mergers. The Spitzer KPAIR sample (27 pairs, 54 galaxies) includes all spectroscopically confirmed spiral-spiral (S+S) and spiral-elliptical (S+E) pairs in a parent sample that is complete for primaries brighter than K = 12.5 mag, projected separations of 5 h -1 kpc ≤ s ≤ 20 h -1 kpc, and mass ratios ≤2.5. The Spitzer data, consisting of images in seven bands (3.6, 4.5, 5.8, 8, 24, 70, 160 μm), show very diversified IR emission properties. Compared to single spiral galaxies in a control sample, only spiral galaxies in S+S pairs show significantly enhanced specific star formation rate (sSFR = SFR/M), whereas spiral galaxies in S+E pairs do not. Furthermore, the SFR enhancement of spiral galaxies in S+S pairs is highly mass-dependent. Only those with M ∼> 10 10.5 M sun show significant enhancement. Relatively low-mass (M ∼ 10 10 M sun ) spirals in S+S pairs have about the same SFR/M compared to their counterparts in the control sample, while those with 10 11 M sun have on average a ∼3 times higher SFR/M than single spirals. There is evidence for a correlation between the global star formation activities (but not the nuclear activities) of the component galaxies in massive S+S major-merger pairs (the H olmberg effect ) . There is no significant difference in the SFR/M between the primaries and the secondaries, nor between spirals of SEP KPAIR =2.54 x 10 -4 (M sun yr -1 Mpc -3 ).

  20. N-parameter retrievals from L-band microwave observations acquired over a variety of crop fields

    DEFF Research Database (Denmark)

    Pardé, M.; Wigneron, J-P.; Waldteufel, P.

    2004-01-01

    A number of studies have shown the feasibility of estimating surface soil moisture from L-band passive microwave measurements. Such measurements should be acquired in the near future by the Soil Moisture and Ocean Salinity (SMOS) mission. The SMOS measurements will be done at many incidence angles...

  1. Deep absorption band in Cu(In,Ga)Se{sub 2} thin films and solar cells observed by transparent piezoelectric photothermal spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Shirakata, Sho; Atarashi, Akiko [Faculty of Engineering, Ehime University, Matsuyama 790-8577 (Japan); Yagi, Masakazu [Kagawa National College of Technology, Mitoyo-shi 769-1192 (Japan)

    2015-06-15

    The photo-acoustic spectroscopy (PAS) using a transparent piezoelectric photo-thermal (Tr-PPT) method was carried out on Cu(In,Ga)Se{sub 2} (CIGS) thin films (both CIGS/Mo/SLG and CdS/CIGS/Mo/SLG) and solar cells (ZnO/CdS/CIGS/Mo/SLG). Using the Tr-PPT method, the high background absorption in the below gap region observed in both a microphone and a conventional transducer PAS spectra was strongly reduced. This high background absorption came from the CIGS/Mo interface. This result proves that the Tr-PPT PAS is the surface sensitive method. In the below-band region, a bell-shape deep absorption band has been observed at 0.76 eV, in which a full-width at the half-maximum value was 70-120 meV. This deep absorption band was observed for both CdS/CIGS/Mo/SLG and ZnO/CdS/CIGS/Mo/SLG structures. The peak energy of the absorption band was independent of the alloy composition for 0.25≤Ga/III≤0.58. Intensity of the PA signal was negatively correlated to the Na concentration at the CIGS film surface. The origin of the 0.76 eV peak is discussed with relation to native defects such as a Cu-vacancy-related defect (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Inferring Land Surface Model Parameters for the Assimilation of Satellite-Based L-Band Brightness Temperature Observations into a Soil Moisture Analysis System

    Science.gov (United States)

    Reichle, Rolf H.; De Lannoy, Gabrielle J. M.

    2012-01-01

    The Soil Moisture and Ocean Salinity (SMOS) satellite mission provides global measurements of L-band brightness temperatures at horizontal and vertical polarization and a variety of incidence angles that are sensitive to moisture and temperature conditions in the top few centimeters of the soil. These L-band observations can therefore be assimilated into a land surface model to obtain surface and root zone soil moisture estimates. As part of the observation operator, such an assimilation system requires a radiative transfer model (RTM) that converts geophysical fields (including soil moisture and soil temperature) into modeled L-band brightness temperatures. At the global scale, the RTM parameters and the climatological soil moisture conditions are still poorly known. Using look-up tables from the literature to estimate the RTM parameters usually results in modeled L-band brightness temperatures that are strongly biased against the SMOS observations, with biases varying regionally and seasonally. Such biases must be addressed within the land data assimilation system. In this presentation, the estimation of the RTM parameters is discussed for the NASA GEOS-5 land data assimilation system, which is based on the ensemble Kalman filter (EnKF) and the Catchment land surface model. In the GEOS-5 land data assimilation system, soil moisture and brightness temperature biases are addressed in three stages. First, the global soil properties and soil hydraulic parameters that are used in the Catchment model were revised to minimize the bias in the modeled soil moisture, as verified against available in situ soil moisture measurements. Second, key parameters of the "tau-omega" RTM were calibrated prior to data assimilation using an objective function that minimizes the climatological differences between the modeled L-band brightness temperatures and the corresponding SMOS observations. Calibrated parameters include soil roughness parameters, vegetation structure parameters

  3. Observation of coherently enhanced tunable narrow-band terahertz transition radiation from a relativistic sub-picosecond electron bunch train

    International Nuclear Information System (INIS)

    Piot, P.; Maxwell, T. J.; Sun, Y.-E; Ruan, J.; Lumpkin, A. H.; Thurman-Keup, R.; Rihaoui, M. M.

    2011-01-01

    We experimentally demonstrate the production of narrow-band (δf/f≅20% at f≅0.5THz) transition radiation with tunable frequency over [0.37, 0.86] THz. The radiation is produced as a train of sub-picosecond relativistic electron bunches transits at the vacuum-aluminum interface of an aluminum converter screen. The bunch train is generated via a transverse-to-longitudinal phase space exchange technique. We also show a possible application of modulated beams to extend the dynamical range of a popular bunch length diagnostic technique based on the spectral analysis of coherent radiation.

  4. Observation of band bending of metal/high-k Si capacitor with high energy x-ray photoemission spectroscopy and its application to interface dipole measurement

    Science.gov (United States)

    Kakushima, K.; Okamoto, K.; Tachi, K.; Song, J.; Sato, S.; Kawanago, T.; Tsutsui, K.; Sugii, N.; Ahmet, P.; Hattori, T.; Iwai, H.

    2008-11-01

    Band bendings of Si substrates have been observed using hard x-ray photoemission spectroscopy. With a capability of collecting photoelectrons generated as deep as 40 nm, the binding energy shift in a core level caused by the potential profile at the surface of the substrate results in a spectrum broadening. The broadening is found to be significant when heavily doped substrates are used owing to its steep potential profile. The surface potential of the substrate can be obtained by deconvolution of the spectrum. This method has been applied to observe the band bending profile of metal-oxide-semiconductor capacitors with high-k gate dielectrics. By comparing the band bending profiles of heavily-doped n+- and p+-Si substrates, the interface dipoles presented at interfaces can be estimated. In the case of W gated La2O3/La-silicate capacitor, an interface dipole to shift the potential of -0.45 V has been estimated at La-silicate/Si interface, which effectively reduces the apparent work function of W. On the other hand, an interface dipole of 0.03-0.07 V has been found to exist at Hf-silicate/SiO2 interface for W gated HfO2/Hf-silicate/SiO2 capacitor.

  5. Observation of snowfall with a low-power FM-CW K-band radar (Micro Rain Radar)

    Science.gov (United States)

    Kneifel, Stefan; Maahn, Maximilian; Peters, Gerhard; Simmer, Clemens

    2011-06-01

    Quantifying snowfall intensity especially under arctic conditions is a challenge because wind and snow drift deteriorate estimates obtained from both ground-based gauges and disdrometers. Ground-based remote sensing with active instruments might be a solution because they can measure well above drifting snow and do not suffer from flow distortions by the instrument. Clear disadvantages are, however, the dependency of e.g. radar returns on snow habit which might lead to similar large uncertainties. Moreover, high sensitivity radars are still far too costly to operate in a network and under harsh conditions. In this paper we compare returns from a low-cost, low-power vertically pointing FM-CW radar (Micro Rain Radar, MRR) operating at 24.1 GHz with returns from a 35.5 GHz cloud radar (MIRA36) for dry snowfall during a 6-month observation period at an Alpine station (Environmental Research Station Schneefernerhaus, UFS) at 2,650 m height above sea level. The goal was to quantify the potential and limitations of the MRR in relation to what is achievable by a cloud radar. The operational MRR procedures to derive standard radar variables like effective reflectivity factor ( Z e) or the mean Doppler velocity ( W) had to be modified for snowfall since the MRR was originally designed for rain observations. Since the radar returns from snowfall are weaker than from comparable rainfall, the behavior of the MRR close to its detection threshold has been analyzed and a method is proposed to quantify the noise level of the MRR based on clear sky observations. By converting the resulting MRR- Z e into 35.5 GHz equivalent Z e values, a remaining difference below 1 dBz with slightly higher values close to the noise threshold could be obtained. Due to the much higher sensitivity of MIRA36, the transition of the MRR from the true signal to noise can be observed, which agrees well with the independent clear sky noise estimate. The mean Doppler velocity differences between both radars

  6. The broad-band X-ray spectrum of IC 4329A from a joint NuSTAR/Suzaku observation

    DEFF Research Database (Denmark)

    Brenneman, L. W.; Madejski, G.; Fuerst, F.

    2014-01-01

    We have obtained a deep, simultaneous observation of the bright, nearby Seyfert galaxy IC 4329A with Suzaku andNuSTAR. Through a detailed spectral analysis, we are able to robustly separate the continuum, absorption, and distant reflection components in the spectrum. The absorbing column is found...... also updated our previously reported measurement of the high-energy cutoff of the hard X-ray emission using both observatories rather than justNuSTAR alone: Ecut = 186±14 keV. This high-energy cutoff acts as a proxy for the temperature of the coronal electron plasma, enabling us to further separate...

  7. Observations of C-Band Brightness Temperature and Ocean Surface Wind Speed and Rain Rate in Hurricanes Earl And Karl (2010)

    Science.gov (United States)

    Miller, Timothy; James, Mark; Roberts, Brent J.; Biswax, Sayak; Uhlhorn, Eric; Black, Peter; Linwood Jones, W.; Johnson, Jimmy; Farrar, Spencer; Sahawneh, Saleem

    2012-01-01

    Ocean surface emission is affected by: a) Sea surface temperature. b) Wind speed (foam fraction). c) Salinity After production of calibrated Tb fields, geophysical fields wind speed and rain rate (or column) are retrieved. HIRAD utilizes NASA Instrument Incubator Technology: a) Provides unique observations of sea surface wind, temp and rain b) Advances understanding & prediction of hurricane intensity c) Expands Stepped Frequency Microwave Radiometer capabilities d) Uses synthetic thinned array and RFI mitigation technology of Lightweight Rain Radiometer (NASA Instrument Incubator) Passive Microwave C-Band Radiometer with Freq: 4, 5, 6 & 6.6 GHz: a) Version 1: H-pol for ocean wind speed, b) Version 2: dual ]pol for ocean wind vectors. Performance Characteristics: a) Earth Incidence angle: 0deg - 60deg, b) Spatial Resolution: 2-5 km, c) Swath: approx.70 km for 20 km altitude. Observational Goals: WS 10 - >85 m/s RR 5 - > 100 mm/hr.

  8. Mesoscale kinematics derived from X-band Doppler radar observations of convective versus stratiform precipitation and comparison with GPS radiosonde profiles

    Science.gov (United States)

    Deshpande, Sachin M.; Dhangar, N.; Das, S. K.; Kalapureddy, M. C. R.; Chakravarty, K.; Sonbawne, S.; Konwar, M.

    2015-11-01

    Single Doppler analysis techniques known as velocity azimuth display (VAD) and volume velocity processing (VVP) are used to analyze kinematics of mesoscale flow such as horizontal wind and divergence using X-band Doppler weather radar observations, for selected cases of convective, stratiform, and shallow cloud systems near tropical Indian sites Pune (18.58°N, 73.92°E, above sea level (asl) 560 m) and Mandhardev (18.51°N, 73.85°E, asl 1297 m). The vertical profiles of horizontal wind estimated from radar VVP/VAD methods agree well with GPS radiosonde profiles, with the low-level jet at about 1.5 km during monsoon season well depicted in both. The vertical structure and temporal variability of divergence and reflectivity profiles are indicative of the dynamical and microphysical characteristics of shallow convective, deep convective, and stratiform cloud systems. In shallow convective systems, vertical development of reflectivity profiles is limited below 5 km. In deep convective systems, reflectivity values as large as 55 dBZ were observed above freezing level. The stratiform system shows the presence of a reflectivity bright band (~35 dBZ) near the melting level. The diagnosed vertical profiles of divergence in convective and stratiform systems are distinct. In shallow convective conditions, convergence was seen below 4 km with divergence above. Low-level convergence and upper level divergence are observed in deep convective profiles, while stratiform precipitation has midlevel convergence present between lower level and upper level divergence. The divergence profiles in stratiform precipitation exhibit intense shallow layers of "melting convergence" at 0°C level, near 4.5 km altitude, with a steep gradient on the both sides of the peak. The level of nondivergence in stratiform situations is lower than that in convective situations. These observed vertical structures of divergence are largely indicative of latent heating profiles in the atmosphere, an

  9. Mesoscale spiral vortex embedded within a Lake Michigan snow squall band - High resolution satellite observations and numerical model simulations

    Science.gov (United States)

    Lyons, Walter A.; Keen, Cecil S.; Hjelmfelt, Mark; Pease, Steven R.

    1988-01-01

    It is known that Great Lakes snow squall convection occurs in a variety of different modes depending on various factors such as air-water temperature contrast, boundary-layer wind shear, and geostrophic wind direction. An exceptional and often neglected source of data for mesoscale cloud studies is the ultrahigh resolution multispectral data produced by Landsat satellites. On October 19, 1972, a clearly defined spiral vortex was noted in a Landsat-1 image near the southern end of Lake Michigan during an exceptionally early cold air outbreak over a still very warm lake. In a numerical simulation using a three-dimensional Eulerian hydrostatic primitive equation mesoscale model with an initially uniform wind field, a definite analog to the observed vortex was generated. This suggests that intense surface heating can be a principal cause in the development of a low-level mesoscale vortex.

  10. Comparison of convective clouds observed by spaceborne W-band radar and simulated by cloud-resolving atmospheric models

    Science.gov (United States)

    Dodson, Jason B.

    Deep convective clouds (DCCs) play an important role in regulating global climate through vertical mass flux, vertical water transport, and radiation. For general circulation models (GCMs) to simulate the global climate realistically, they must simulate DCCs realistically. GCMs have traditionally used cumulus parameterizations (CPs). Much recent research has shown that multiple persistent unrealistic behaviors in GCMs are related to limitations of CPs. Two alternatives to CPs exist: the global cloud-resolving model (GCRM), and the multiscale modeling framework (MMF). Both can directly simulate the coarser features of DCCs because of their multi-kilometer horizontal resolutions, and can simulate large-scale meteorological processes more realistically than GCMs. However, the question of realistic behavior of simulated DCCs remains. How closely do simulated DCCs resemble observed DCCs? In this study I examine the behavior of DCCs in the Nonhydrostatic Icosahedral Atmospheric Model (NICAM) and Superparameterized Community Atmospheric Model (SP-CAM), the latter with both single-moment and double-moment microphysics. I place particular emphasis on the relationship between cloud vertical structure and convective environment. I also emphasize the transition between shallow clouds and mature DCCs. The spatial domains used are the tropical oceans and the contiguous United States (CONUS), the latter of which produces frequent vigorous convection during the summer. CloudSat is used to observe DCCs, and A-Train and reanalysis data are used to represent the large-scale environment in which the clouds form. The CloudSat cloud mask and radar reflectivity profiles for CONUS cumuliform clouds (defined as clouds with a base within the planetary boundary layer) during boreal summer are first averaged and compared. Both NICAM and SP-CAM greatly underestimate the vertical growth of cumuliform clouds. Then they are sorted by three large-scale environmental variables: total preciptable

  11. Formation of bands of ultrafine beryllium particles during rapid solidification of Al-Be alloys: Modeling and direct observations

    International Nuclear Information System (INIS)

    Elmer, J.W.; Tanner, L.E.; Smith, P.M.; Wall, M.A.; Aziz, M.J.

    1994-01-01

    Rapid solidification of dilute hyper-eutectic and monotectic alloys sometimes produces a dispersion of ultrafine randomly-oriented particles that lie in arrays parallel to the advancing solidification front. The authors characterize this effect in Al-Be where Be-rich particles with diameters on the order of 10 nm form in arrays spaced approximately 25 nm apart, and they present a model of macroscopically steady state but microscopically oscillatory motion of the solidification front to explain this unusual microstructure. The proposed mechanism involves; (i) the build-up of rejected solute in a diffusional boundary layer which slows down the growing crystal matrix, (2) the boundary layer composition entering a metastable liquid miscibility gap, (3) homogeneous nucleation of solute rich liquid droplets in the boundary layer, and crystallization of these droplets, and (4) growth of the matrix past the droplets and its reformation into a planar interface. The size of the Be-rich particles is limited by the beryllium supersaturation in the diffusional boundary layer. A numerical model was developed to investigate this solidification mechanism, and the results of the model are in good agreement with experimental observations of rapidly solidified Al-5 at.% Be

  12. Cluster observations of band-limited Pc 1 waves associated with streaming H+ and O+ ions in the high-altitude plasma mantle

    Science.gov (United States)

    Engebretson, M. J.; Kahlstorf, C. R. G.; Murr, D. L.; Posch, J. L.; Keiling, A.; Lavraud, B.; Rème, H.; Lessard, M. R.; Kim, E.-H.; Johnson, J. R.; Dombeck, J.; Grison, B.; Robert, P.; Glassmeier, K.-H.; Décréau, P. M. E.

    2012-10-01

    Bursts of band-limited Pc 1 waves (0.2 to ˜1.0 Hz) with normalized frequency f/fH+ ˜ 0.5 have been observed by the Cluster spacecraft during many passes through the high-latitude plasma mantle. These transverse, left-hand polarized waves are associated with regions of H+ and O+ ions streaming away from Earth along magnetic field lines at the same velocity (˜140 km/s). Waves were observed only when H+ fluxes increased by factors of 10-1000 and energies of both ion species increased by factors of up to 10. We present two satellite-ground conjunctions to demonstrate the high latitude localization of these waves and their ability to reach the polar ionosphere and two extended examples of waves and associated ion distribution functions near the southern dusk flank magnetopause. We also present the results of a search for all such events during Cluster's 2002 and 2003 passages through the magnetotail, with orbital precession covering dawn to dusk on Earth's night side (June through December). A total of 46 events (band-limited Pc 1-2 waves accompanied by a sustained population of streaming H+ and O+ ions, separated by at least 12 min) were observed on 29 days. The waves were generally associated with intervals of southward IMF Bz and/or large IMF By (times of active cusp reconnection), and often but not always occurred during the main phase or early recovery phase of magnetic storms. Analysis of selected events shows that the waves are associated with large H+ temperature anisotropy, and that the waves propagate opposite to the direction of the streaming ions. A wave instability analysis using the WHAMP code confirms that the generation of these waves, via the ion cyclotron instability, is basically consistent with known physics. Their extended region of wave growth is likely, however, to reach tailward significantly beyond the Cluster orbit.

  13. The Cryogenic AntiCoincidence detector for ATHENA X-IFU: a scientific assessment of the observational capabilities in the hard X-ray band

    Science.gov (United States)

    D'Andrea, M.; Lotti, S.; Macculi, C.; Piro, L.; Argan, A.; Gatti, F.

    2017-12-01

    ATHENA is a large X-ray observatory, planned to be launched by ESA in 2028 towards an L2 orbit. One of the two instruments of the payload is the X-IFU: a cryogenic spectrometer based on a large array of TES microcalorimeters, able to perform integral field spectrography in the 0.2-12 keV band (2.5 eV FWHM at 6 keV). The X-IFU sensitivity is highly degraded by the particle background expected in the L2 orbit, which is induced by primary protons of both galactic and solar origin, and mostly by secondary electrons. To reduce the particle background level and enable the mission science goals, the instrument incorporates a Cryogenic AntiCoincidence detector (CryoAC). It is a 4 pixel TES based detector, placed 10 keV). The aim of the study has been to understand if the present detector design can be improved in order to enlarge the X-IFU scientific capability on an energy band wider than the TES array. This is beyond the CryoAC baseline, being this instrument aimed to operate as anticoincidence particle detector and not conceived to perform X-ray observations.

  14. BAND-9 ALMA OBSERVATIONS OF THE [N II] 122 μm LINE AND FIR CONTINUUM IN TWO HIGH-z GALAXIES

    Energy Technology Data Exchange (ETDEWEB)

    Ferkinhoff, Carl [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); Brisbin, Drew; Stacey, Gordon J. [Department of Astronomy, Cornell University, Ithaca, NY 14853 (United States); Nikola, Thomas [Center for Radiophysics and Space Research, Cornell University, Ithaca, NY 14853 (United States); Sheth, Kartik [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Hailey-Dunsheath, Steve [California Institute of Technology, Mail Code 301-17, 1200 E. California Blvd., Pasadena, CA 91125 (United States); Falgarone, Edith, E-mail: ferkinhoff@mpia.de [LERMA, CNRS, Observatoire de Paris and ENS (France)

    2015-06-20

    We present Atacama Large Millimeter Array (ALMA) observations of two high-redshift systems (SMMJ02399-0136 at z{sub 1} ∼ 2.8 and the Cloverleaf QSO at z{sub 1} ∼ 2.5) in their rest-frame 122 μm continuum (ν{sub sky} ∼ 650 GHz, λ{sub sky} ∼ 450 μm) and [N ii] 122 μm line emission. The continuum observations with a synthesized beam of ∼0.″ 25 resolve both sources and recover the expected flux. The Cloverleaf is resolved into a partial Einstein ring, while SMMJ02399-0136 is unambiguously separated into two components: a point source associated with an active galactic nucleus and an extended region at the location of a previously identified dusty starburst. We detect the [N ii] line in both systems, though significantly weaker than our previous detections made with the first generation z (Redshift) and Early Universe Spectrometer. We show that this discrepancy is mostly explained if the line flux is resolved out due to significantly more extended emission and longer ALMA baselines than expected. Based on the ALMA observations we determine that ≥75% of the total [N ii] line flux in each source is produced via star formation. We use the [N ii] line flux that is recovered by ALMA to constrain the N/H abundance, ionized gas mass, hydrogen- ionizing photon rate, and star formation rate. In SMMJ02399-0136 we discover it contains a significant amount (∼1000 M{sub ⊙} yr{sup −1}) of unobscured star formation in addition to its dusty starburst and argue that SMMJ02399-0136 may be similar to the Antennae Galaxies (Arp 244) locally. In total these observations provide a new look at two well-studied systems while demonstrating the power and challenges of Band-9 ALMA observations of high-z systems.

  15. Band-9 ALMA Observations of the [N II] 122 μm Line and FIR Continuum in Two High-z galaxies.

    Science.gov (United States)

    Ferkinhoff, Carl; Brisbin, Drew; Nikola, Thomas; Stacey, Gordon J.; Sheth, Kartik; Hailey-Dunsheath, Steve; Falgarone, Edith

    2015-06-01

    We present Atacama Large Millimeter Array (ALMA) observations of two high-redshift systems (SMMJ02399-0136 at z 1 ˜ 2.8 and the Cloverleaf QSO at z 1 ˜ 2.5) in their rest-frame 122 μm continuum (ν sky ˜ 650 GHz, λ sky ˜ 450 μm) and [N ii] 122 μm line emission. The continuum observations with a synthesized beam of ˜0.″ 25 resolve both sources and recover the expected flux. The Cloverleaf is resolved into a partial Einstein ring, while SMMJ02399-0136 is unambiguously separated into two components: a point source associated with an active galactic nucleus and an extended region at the location of a previously identified dusty starburst. We detect the [N ii] line in both systems, though significantly weaker than our previous detections made with the first generation z (Redshift) and Early Universe Spectrometer. We show that this discrepancy is mostly explained if the line flux is resolved out due to significantly more extended emission and longer ALMA baselines than expected. Based on the ALMA observations we determine that ≥75% of the total [N ii] line flux in each source is produced via star formation. We use the [N ii] line flux that is recovered by ALMA to constrain the N/H abundance, ionized gas mass, hydrogen- ionizing photon rate, and star formation rate. In SMMJ02399-0136 we discover it contains a significant amount (˜1000 M ⊙ yr-1) of unobscured star formation in addition to its dusty starburst and argue that SMMJ02399-0136 may be similar to the Antennae Galaxies (Arp 244) locally. In total these observations provide a new look at two well-studied systems while demonstrating the power and challenges of Band-9 ALMA observations of high-z systems.

  16. The GAPS Programme with HARPS-N at TNG. XV. A substellar companion around a K giant star identified with quasi-simultaneous HARPS-N and GIANO measurements

    Science.gov (United States)

    González-Álvarez, E.; Affer, L.; Micela, G.; Maldonado, J.; Carleo, I.; Damasso, M.; D'Orazi, V.; Lanza, A. F.; Biazzo, K.; Poretti, E.; Gratton, R.; Sozzetti, A.; Desidera, S.; Sanna, N.; Harutyunyan, A.; Massi, F.; Oliva, E.; Claudi, R.; Cosentino, R.; Covino, E.; Maggio, A.; Masiero, S.; Molinari, E.; Pagano, I.; Piotto, G.; Smareglia, R.; Benatti, S.; Bonomo, A. S.; Borsa, F.; Esposito, M.; Giacobbe, P.; Malavolta, L.; Martinez-Fiorenzano, A.; Nascimbeni, V.; Pedani, M.; Rainer, M.; Scandariato, G.

    2017-10-01

    Context. Identification of planetary companions of giant stars is made difficult because of the astrophysical noise, that may produce radial velocity variations similar to those induced by a companion. On the other hand any stellar signal is wavelength dependent, while signals due to a companion are achromatic. Aims: Our goal is to determine the origin of the Doppler periodic variations observed in the thick disk K giant star TYC 4282-605-1 by HARPS-N at the Telescopio Nazionale Galileo (TNG) and verify if they can be due to the presence of a substellar companion. Methods: Several methods have been used to exclude the stellar origin of the observed signal including detailed analysis of activity indicators and bisector and the analysis of the photometric light curve. Finally we have conducted an observational campaign to monitor the near infrared (NIR) radial velocity with GIANO at the TNG in order to verify whether the NIR amplitude variations are comparable with those observed in the visible. Results: Both optical and NIR radial velocities show consistent variations with a period at 101 days and similar amplitude, pointing to the presence of a companion orbiting the target. The main orbital properties obtained for our giant star with a derived mass of M = 0.97 ± 0.03M⊙ are MPsini = 10.78 ± 0.12MJ; P = 101.54 ± 0.05 days; e = 0.28 ± 0.01 and a = 0.422 ± 0.009 AU. The chemical analysis shows a significant enrichment in the abundance of Na I, Mg I, Al I and Si I while the rest of analyzed elements are consistent with the solar value demonstrating that the chemical composition corresponds with an old K giant (age = 10.1 Gyr) belonging to local thick disk. Conclusions: We conclude that the substellar companion hypothesis for this K giant is the best explanation for the observed periodic radial velocity variation. This study also shows the high potential of multi-wavelength radial velocity observations for the validation of planet candidates. Based on

  17. The hierarchically organized splitting of chromosome bands into sub-bands analyzed by multicolor banding (MCB).

    Science.gov (United States)

    Lehrer, H; Weise, A; Michel, S; Starke, H; Mrasek, K; Heller, A; Kuechler, A; Claussen, U; Liehr, T

    2004-01-01

    To clarify the nature of chromosome sub-bands in more detail, the multicolor banding (MCB) probe-set for chromosome 5 was hybridized to normal metaphase spreads of GTG band levels at approximately 850, approximately 550, approximately 400 and approximately 300. It could be observed that as the chromosomes became shorter, more of the initial 39 MCB pseudo-colors disappeared, ending with 18 MCB pseudo-colored bands at the approximately 300-band level. The hierarchically organized splitting of bands into sub-bands was analyzed by comparing the disappearance or appearance of pseudo-color bands of the four different band levels. The regions to split first are telomere-near, centromere-near and in 5q23-->q31, followed by 5p15, 5p14, and all GTG dark bands in 5q apart from 5q12 and 5q32 and finalized by sub-band building in 5p15.2, 5q21.2-->q21.3, 5q23.1 and 5q34. The direction of band splitting towards the centromere or the telomere could be assigned to each band separately. Pseudo-colors assigned to GTG-light bands were resistant to band splitting. These observations are in concordance with the recently proposed concept of chromosome region-specific protein swelling. Copyright 2003 S. Karger AG, Basel

  18. Multiband Observations of the Quasar PKS 2326–502 during Active and Quiescent Gamma-Ray States in 2010–2012

    Energy Technology Data Exchange (ETDEWEB)

    Dutka, Michael S. [The Catholic University of America, 620 Michigan Avenue, NE, Washington, DC 20064 (United States); Carpenter, Bryce D.; Gehrels, Neil [NASA Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771 (United States); Ojha, Roopesh [UMBC/NASA Goddard Space Flight Center, Astrophysics Science Division, Code 661, Greenbelt, MD 20771 (United States); Finke, Justin D. [Naval Research Laboratory, Space Science Division, Code 7653, 4555 Overlook Avenue, SW, Washington, DC 20375 (United States); D’Ammando, Filippo [Università di Bologna Dipartimento di Fisica e Astronomia, INAF-IRA, Bologna (Italy); Kadler, Matthias [Lehrstuhl für Astronomie, Universität Würzburg, Emil -Fischer-Straße 31, D-97074 Würzburg (Germany); Edwards, Philip G. [CSIRO Astronomy and Space Science, P.O. Box 76, Epping NSW 1710 (Australia); Stevens, Jamie [CSIRO Astronomy and Space Science, 1828 Yarrie Lake Road, Narrabri NSW 2390 (Australia); Torresi, Eleonora; Grandi, Paola [Istituto Nazionale di Astrofisica, (National Institute of Astrophysics) INAF-IASFBO, via Gobetti 101, I-40129 Bologna (Italy); Nesci, Roberto [Istituto Nazionale di Astrofisica, (National Institute of Astrophysics) INAF-IAPS, via Fosso del Cavaliere 100, I-00133 Roma (Italy); Krauß, Felicia [GRAPPA and Anton Pannekoek Institute for Astronomy, University of Amsterdam, Science Park 904, 1098 XH Amsterdam (Netherlands); Müller, Cornelia [Department of Astrophysics/IMAPP, Radboud University Nijmegen, P.O. Box 9010, 6500 GL, Nijmegen (Netherlands); Wilms, Joern, E-mail: ditko86@gmail.com, E-mail: carpbr01@gmail.com [Remeis Observatory and ECAP, Sternwartstr. 7, D-96049 Bamberg (Germany)

    2017-02-01

    Quasi-simultaneous observations of the Flat Spectrum Radio Quasar PKS 2326−502 were carried out in the γ -ray, X-ray, UV, optical, near-infrared, and radio bands. Using these observations, we are able to characterize the spectral energy distribution (SED) of the source during two flaring and one quiescent γ -ray states. These data were used to constrain one-zone leptonic models of the SEDs of each flare and investigate the physical conditions giving rise to them. While modeling one flare required only changes in the electron spectrum compared to the quiescent state, modeling the other flare required changes in both the electron spectrum and the size of the emitting region. These results are consistent with an emerging pattern of two broad classes of flaring states seen in blazars. Type 1 flares are explained by changes solely in the electron distribution, whereas type 2 flares require a change in an additional parameter. This suggests that different flares, even in the same source, may result from different physical conditions or different regions in the jet.

  19. Seeing the Night in a New Light—VIIRS Day/Night Band Capabilities and Prospects for a Joint Suomi/JPSS-1 Observing System

    Science.gov (United States)

    Solbrig, J. E.; Miller, S. D.; Straka, W. C.; Seaman, C.; Combs, C.; Heidinger, A.; Walther, A.

    2017-12-01

    The Day/Night Band (DNB), a special sensor on board the Visible/Infrared Imaging Radiometer Suite (VIIRS) devoted to low-light visible imaging, has representated a kind of `disruptive technology' in terms of how we observe the nocturnal environment. Since its debut on the Suomi National Polar-orbiting Partnership (NPP), launched in Fall 2011, the DNB has solidified its claim to fame as the most novel addition to the National Oceanic and Atmospheric Administration's future polar-oribitng program, represented by the Joint Polar Satellite System (JPSS). The first member of which (JPSS-1) is scheduled to launch in Fall of 2017, joining Suomi in its 1330 local time ascending node orbit. JPSS-1 will be displaced by ½ orbit ahead of Suomi, providing roughly 50 min between overpasses. Importantly, JPSS-1 will provide a second DNB observation, enabling the first time-resolved measurements of low-light visible at low and mid-latitudes from this new sensor technology. The DNB provides unprecedented capability to leverage light emissions from natural and artificial nocturnal sources, ranging from moonlight and city lights, ships, fires, lightning flashes, and even atmospheric nightglow. The calibrated DNB observations enable use of moonlight in similar way to daytime visible, allowing for quantitative description of cloud and aerosol optical properties. This presentation updates the community on DNB-related research initiatives. Statistics based on a multi-year collection of data at Salar de Uyuni, Bolivia and White Sands, New Mexico lend confidence to the performance of a lunar irradiance model used to enable nighttime optical property retrievals. Selected examples of notable events, including the devastating Portugal wildfires, emergence of the massive rift in the Larsen C ice shelf, and examples from the growing compilation of atmospheric gravity waves in nightglow, will also be highlighted.

  20. Vascular density of superficial esophageal squamous cell carcinoma determined by direct observation of resected specimen using narrow band imaging with magnifying endoscopy.

    Science.gov (United States)

    Kikuchi, D; Iizuka, T; Hoteya, S; Nomura, K; Kuribayashi, Y; Toba, T; Tanaka, M; Yamashita, S; Furuhata, T; Matsui, A; Mitani, T; Inoshita, N; Kaise, M

    2017-11-01

    Observation of the microvasculature using narrow band imaging (NBI) with magnifying endoscopy is useful for diagnosing superficial squamous cell carcinoma. Increased vascular density is indicative of cancer, but not many studies have reported differences between cancerous and noncancerous areas based on an objective comparison. We observed specimens of endoscopic submucosal dissection (ESD) using NBI magnification, and determined the vascular density of cancerous and noncancerous areas. A total of 25 lesions of esophageal squamous cell carcinoma that were dissected en bloc by ESD between July 2013 and December 2013 were subjected to NBI magnification. We constructed a device that holds an endoscope and precisely controls the movement along the vertical axis in order to observe submerged specimens by NBI magnification. NBI image files of both cancerous (pathologically determined invasion depth, m1/2) and surrounding noncancerous areas were created and subjected to vascular density assessment by two endoscopists who were blinded to clinical information. The invasion depth was m1/2 in 20, m3/sm1 in four and sm2 in one esophageal cancer lesion. Mean vascular density was significantly increased in cancerous areas (37.6 ± 16.3 vessels/mm2) compared with noncancerous areas (17.6 ± 10.0 vessels/mm2) (P squamous cell carcinoma. The rates of agreement between vascular density values determined by two independent operators were high. © The Authors 2017. Published by Oxford University Press on behalf of International Society for Diseases of the Esophagus. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  1. Anomalous ELF phenomena in the Schumann resonance band as observed at Moshiri (Japan in possible association with an earthquake in Taiwan

    Directory of Open Access Journals (Sweden)

    M. Hayakawa

    2008-12-01

    Full Text Available The ELF observation at Moshiri (geographic coordinates: 44.29° N, 142.21° E in Hokkaido, Japan, was used to find anomalous phenomena in the Schumann resonance band, possibly associated with a large earthquake (magnitude of 7.8 in Taiwan on 26 December 2006. The Schumann resonance signal (fundamental (n=1, 8 Hz; 2nd harmonic, 14 Hz, 3rd harmonic, 20 Hz, 4th, 26 Hz etc. is known to be supported by electromagnetic radiation from the global thunderstorms, and the anomaly in this paper is characterized by an increase in intensity at frequencies from the third to fourth Schumann resonance modes mainly in the BEW component with a minor corresponding increase in the BNS component also. Spectral modification takes place only in the interval of 21:00 UT±1 h, which corresponds to the global lightning activity concentrated in America. While distortions were absent in other lightning-active UT intervals, in particular, around 08:00 UT±1 h (Asian thunderstorms and around 15±1 h (African lightning activity. The anomaly occurred on 23 December three days prior to the main shock. The results observed were explained in terms of ELF radio wave perturbation caused by the lower ionospheric depression around the earthquake epicenter. The difference in the path lengths between the direct radio wave from an active global thunderstorm center and the wave scattered from the non-uniformity above Taiwan causes interference at higher resonance modes, which is successful in explaining the observational data.

  2. A particle swarm optimized kernel-based clustering method for crop mapping from multi-temporal polarimetric L-band SAR observations

    Science.gov (United States)

    Tamiminia, Haifa; Homayouni, Saeid; McNairn, Heather; Safari, Abdoreza

    2017-06-01

    Polarimetric Synthetic Aperture Radar (PolSAR) data, thanks to their specific characteristics such as high resolution, weather and daylight independence, have become a valuable source of information for environment monitoring and management. The discrimination capability of observations acquired by these sensors can be used for land cover classification and mapping. The aim of this paper is to propose an optimized kernel-based C-means clustering algorithm for agriculture crop mapping from multi-temporal PolSAR data. Firstly, several polarimetric features are extracted from preprocessed data. These features are linear polarization intensities, and several statistical and physical based decompositions such as Cloude-Pottier, Freeman-Durden and Yamaguchi techniques. Then, the kernelized version of hard and fuzzy C-means clustering algorithms are applied to these polarimetric features in order to identify crop types. The kernel function, unlike the conventional partitioning clustering algorithms, simplifies the non-spherical and non-linearly patterns of data structure, to be clustered easily. In addition, in order to enhance the results, Particle Swarm Optimization (PSO) algorithm is used to tune the kernel parameters, cluster centers and to optimize features selection. The efficiency of this method was evaluated by using multi-temporal UAVSAR L-band images acquired over an agricultural area near Winnipeg, Manitoba, Canada, during June and July in 2012. The results demonstrate more accurate crop maps using the proposed method when compared to the classical approaches, (e.g. 12% improvement in general). In addition, when the optimization technique is used, greater improvement is observed in crop classification, e.g. 5% in overall. Furthermore, a strong relationship between Freeman-Durden volume scattering component, which is related to canopy structure, and phenological growth stages is observed.

  3. Origin of the 2.45 eV luminescence band observed in ZnO epitaxial layers grown on c-plane sapphire by chemical vapour deposition

    International Nuclear Information System (INIS)

    Saroj, R K; Dhar, S

    2014-01-01

    Zinc oxide epitaxial layers have been grown on c-plane sapphire substrates by the chemical vapour deposition (CVD) technique. A structural study shows (0001)-oriented films with good crystalline quality. The temperature and excitation power dependence of the photoluminescence (PL) characteristics of these layers is studied as a function of various growth parameters, such as the growth temperature, oxygen flow rate and Zn flux, which suggest that the origin of the broad visible luminescence (VL), which peaks at 2.45 eV, is the transition between the conduction band and the Zn vacancy acceptor states. A bound excitonic transition observed at 3.32 eV in low temperature PL has been identified as an exciton bound to the neutral Zn vacancy. Our study also reveals the involvement of two activation processes in the dynamics of VL, which has been explained in terms of the fluctuation of the capture barrier height for the holes trapped in Zn vacancy acceptors. The fluctuation, which might be a result of the inhomogeneous distribution of Zn vacancies, is found to be associated with an average height of 7 and 90 meV, respectively, for the local and global maxima. (paper)

  4. Hyperspectral observation of anthropogenic and biogenic pollution in coastal zone

    Science.gov (United States)

    Lavrova, Olga; Loupian, Evgeny; Mityagina, Marina; Uvarov, Ivan

    The work presents results of anthropogenic and biogenic pollution detection in coastal zones of the Black and Caspian Seas based on satellite hyperspetral data provided by the Hyperion and HICO instruments. Techniques developed on the basis of the analysis of spectral characteristics calculated in special points were employed to address the following problems: (a) assessment of the blooming intensity of cyanobacteria and their distribution in bays of western Crimea and discrimination between anthropogenic pollutant discharge events and algae bloom; (b) detection of anthropogenic pollution in Crimean lakes utilized as industrial liquid discharge reservoirs; (c) detection of oil pollution in areas of shelf oil production in the Caspian Sea. Information values of different spectral bands and their composites were estimated in connection with the retrieval of the main sea water components: phytoplankton, suspended matter and colored organic matter, and also various anthropogenic pollutants, including oil. Software tools for thematic hyperspectral data processing in application to the investigation of sea coastal zones and internal water bodies were developed on the basis of the See the Sea geoportal created by the Space Research Institute RAS. The geoportal is focused on the study of processes in the world ocean with the emphasis on the advantages of satellite systems of observation. The tools that were introduced into the portal allow joint analysis of quasi-simultaneous satellite data, in particular data from the Hyperion, HICO, OLI Landsat-8, ETM Landsat-7 and TM Landsat-5 instruments. Results of analysis attempts combining data from different sensors are discussed. Their strong and weak points are highlighted. The study was completed with partial financial support from The Russian Foundation for Basic Research grants # 14-05-00520-a and 13-07-12017.

  5. Multi-variable X-band radar observation and tracking of ash plume from Mt. Etna volcano on November 23, 2013 event

    Science.gov (United States)

    Montopoli, Mario; Vulpiani, Gianfranco; Riccci, Matteo; Corradini, Stefano; Merucci, Luca; Marzano, Frank S.

    2015-04-01

    Ground based weather radar observations of volcanic ash clouds are gaining momentum after recent works which demonstrated their potential use either as stand alone tool or in combination with satellite retrievals. From an operational standpoint, radar data have been mainly exploited to derive the height of ash plume and its temporal-spatial development, taking into account the radar limitation of detecting coarse ash particles (from approximately 20 microns to 10 millimeters and above in terms of particle's radius). More sophisticated radar retrievals can include airborne ash concentration, ash fall rate and out-flux rate. Marzano et al. developed several volcanic ash radar retrieval (VARR) schemes, even though their practical use is still subject to a robust validation activity. The latter is made particularly difficult due to the lack of field campaigns with multiple observations and the scarce repetition of volcanic events. The radar variable, often used to infer the physical features of actual ash clouds, is the radar reflectivity named ZHH. It is related to ash particle size distribution and it shows a nice power law relationship with ash concentration. This makes ZHH largely used in radar-volcanology studies. However, weather radars are often able to detect Doppler frequency shifts and, more and more, they have a polarization-diversity capability. The former means that wind speed spectrum of the ash cloud is potentially inferable, whereas the latter implies that variables other than ZHH are available. Theoretically, these additional radar variables are linked to the degree of eccentricity of ash particles, their orientation and density as well as the presence of strong turbulence effects. Thus, the opportunity to refine the ash radar estimates so far developed can benefit from the thorough analysis of radar Doppler and polarization diversity. In this work we show a detailed analysis of Doppler shifts and polarization variables measured by the X band radar

  6. Observation of the exciton and Urbach band tail in low-temperature-grown GaAs using four-wave mixing spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Webber, D.; Yildirim, M.; Hacquebard, L.; March, S.; Mathew, R.; Gamouras, A.; Hall, K. C. [Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia B3H 4R2 (Canada); Liu, X.; Dobrowolska, M.; Furdyna, J. K. [Department of Physics, University of Notre Dame, Notre Dame, Indiana 46556 (United States)

    2014-11-03

    Four-wave mixing (FWM) spectroscopy reveals clear signatures associated with the exciton, free carrier inter-band transitions, and the Urbach band tail in low-temperature-grown GaAs, providing a direct measure of the effective band gap as well as insight into the influence of disorder on the electronic structure. The ability to detect (and resolve) these contributions, in contrast to linear spectroscopy, is due to an enhanced sensitivity of FWM to the optical joint density of states and to many-body effects. Our experiments demonstrate the power of FWM for studying the near-band-edge optical properties and coherent carrier dynamics in low-temperature-grown semiconductors.

  7. METALLICITY AND TEMPERATURE INDICATORS IN M DWARF K-BAND SPECTRA: TESTING NEW AND UPDATED CALIBRATIONS WITH OBSERVATIONS OF 133 SOLAR NEIGHBORHOOD M DWARFS

    Energy Technology Data Exchange (ETDEWEB)

    Rojas-Ayala, Barbara [Department of Astrophysics, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024 (United States); Covey, Kevin R.; Lloyd, James P. [Department of Astronomy, Cornell University, 122 Sciences Drive, Ithaca, NY 14853 (United States); Muirhead, Philip S., E-mail: babs@amnh.org [Department of Astronomy, California Institute of Technology, 1200 East California Boulevard, MC 249-17, Pasadena, CA 91125 (United States)

    2012-04-01

    We present K-band spectra for 133 nearby (d < 33 ps) M dwarfs, including 18 M dwarfs with reliable metallicity estimates (as inferred from an FGK type companion), 11 M dwarf planet hosts, more than 2/3 of the M dwarfs in the northern 8 pc sample, and several M dwarfs from the LSPM catalog. From these spectra, we measure equivalent widths of the Ca and Na lines, and a spectral index quantifying the absorption due to H{sub 2}O opacity (the H{sub 2}O-K2 index). Using empirical spectral type standards and synthetic models, we calibrate the H{sub 2}O-K2 index as an indicator of an M dwarf's spectral type and effective temperature. We also present a revised relationship that estimates the [Fe/H] and [M/H] metallicities of M dwarfs from their Na I, Ca I, and H{sub 2}O-K2 measurements. Comparisons to model atmosphere provide a qualitative validation of our approach, but also reveal an overall offset between the atomic line strengths predicted by models as compared to actual observations. Our metallicity estimates also reproduce expected correlations with Galactic space motions and H{alpha} emission line strengths, and return statistically identical metallicities for M dwarfs within a common multiple system. Finally, we find systematic residuals between our H{sub 2}O-based spectral types and those derived from optical spectral features with previously known sensitivity to stellar metallicity, such as TiO, and identify the CaH1 index as a promising optical index for diagnosing the metallicities of near-solar M dwarfs.

  8. Tunneling observation at very low temperature of impurity bands within the gap of the Kondo superconducting system CuFe/Pb(T(K)>T(c))

    International Nuclear Information System (INIS)

    Dumoulin, Louis; Le Fur, Daniel

    1976-01-01

    Very low temperature superconducting tunneling experiments on CuFe(12.10 -6 ) backed by superconducting lead show a band of localized states next to the gap edge. There is no quantitative agreement with the perturbative approach of Mueller-Hartmann Zittartz in this system where the Kondo temperature is larger than the superconductive T(c) [fr

  9. Magnetic structure of deformation-induced shear bands in amorphous Fe{sub 80}B{sub 16}Si{sub 4} observed by magnetic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, G.W. [Center for Materials Science, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Hawley, M.E. [Materials Science and Technology Division, (MST-8), Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Markiewicz, D.J. [Department of Chemistry, Princeton University, Princeton, New Jersey 08544 (United States); Spaepen, F.; Barth, E.P. [Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States)

    1999-04-01

    Processing-induced magnetic structures in amorphous metallic alloys are of interest because of their impact on the performance of materials used in electric device applications. Plastic deformation associated with cutting or bending the material to the desired shape occurs through the formation of shear bands. The stress associated with these shear bands induces magnetic domains that can lead to power losses through interaction with the fields and currents involved in normal device operation. These domains have been studied previously using a variety of techniques capable of imaging magnetic domain structures. In an effort to better characterize and understand these issues, we have applied atomic and magnetic force microscopy to these materials to provide three-dimensional nanometer-scale topographic resolution and micrometer-scale magnetic resolution. {copyright} {ital 1999 American Institute of Physics.}

  10. OH-asterisk (7-5) Meinel band dayglow and nightglow measured by the SME limb scanning near infrared spectrometer - Comparison of the observed seasonal variability with two-dimensional model simulations

    Science.gov (United States)

    Le Texier, H.; Solomon, S.; Thomas, R. J.; Garcia, R. R.

    1989-01-01

    Seasonal variations of the OH-asterisk (7-5) mesospheric hydroxyl emission at 1.89 microns observed by the SME near-IR spectrometer are compared with the theoretical predictions of a two-dimensional dynamical/chemical model. The good agreement found at low latitudes for both dayglow and nightglow provides support for the model assumption that breaking gravity waves induce seasonal and latitudinal variations in diffusion. The seasonal behavior of atomic hydrogen in the upper mesosphere (related to vertical transport) and/or uncertainties in the OH Meinel band parameters are proposed as possible explanations for the discrepancy noted between model and observational data for the middle latitudes.

  11. The observation of valence band change on resistive switching of epitaxial Pr{sub 0.7}Ca{sub 0.3}MnO{sub 3} film using removable liquid electrode

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hong-Sub; Park, Hyung-Ho, E-mail: hhpark@yonsei.ac.kr [Department of Materials Science and Engineering, Yonsei University, Seodaemun-Ku, Seoul 120-749 (Korea, Republic of)

    2015-12-07

    The resistive switching (RS) phenomenon in transition metal oxides (TMOs) has received a great deal of attention for non-volatile memory applications. Various RS mechanisms have been suggested as to explain the observed RS characteristics. Many reports suggest that changes of interface and the role of oxygen vacancies originate in RS phenomena; therefore, in this study, we use a liquid drop of mercury as the top electrode (TE), epitaxial Pr{sub 0.7}Ca{sub 0.3}MnO{sub 3} (PCMO) (110) film of the perovskite manganite family for RS material, and an Nb-doped (0.7 at. %) SrTiO{sub 3} (100) single crystal as the substrate to observe changes in the interface between the TE and TMOs. The use of removable liquid electrode Hg drop as TE not only enables observation of the RS characteristic as a bipolar RS curve (counterclockwise) but also facilitates analysis of the valence band of the PCMO surface after resistive switching via photoelectron spectroscopy. The observed I-V behaviors of the low and high resistance states (HRS) are explained with an electrochemical migration model in PCMO film where accumulated oxygen vacancies at the interface between the Hg TE and PCMO (110) surface induce the HRS. The interpreted RS mechanism is directly confirmed via valence band spectrum analysis.

  12. Dipole Bands in 196Hg

    International Nuclear Information System (INIS)

    Lawrie, J. J.; Lawrie, E. A.; Newman, R. T.; Sharpey-Schafer, J. F.; Smit, F. D.; Msezane, B.; Benatar, M.; Mabala, G. K.; Mutshena, K. P.; Federke, M.; Mullins, S. M.; Ncapayi, N. J.; Vymers, P.

    2011-01-01

    High spin states in 196 Hg have been populated in the 198 Pt(α,6n) reaction at 65 MeV and the level scheme has been extended. A new dipole band has been observed and a previously observed dipole has been confirmed. Excitation energies, spins and parities of these bands were determined from DCO ratio and linear polarization measurements. Possible quasiparticle excitations responsible for these structures are discussed.

  13. Relating C-band Microwave and Optical Satellite Observations as A Function of Snow Thickness on First-Year Sea Ice during the Winter to Summer Transition

    Science.gov (United States)

    Zheng, J.; Yackel, J.

    2015-12-01

    The Arctic sea ice and its snow cover have a direct impact on both the Arctic and global climate system through their ability to moderate heat exchange across the ocean-sea ice-atmosphere (OSA) interface. Snow cover plays a key role in the OSA interface radiation and energy exchange, as it controls the growth and decay of first-year sea ice (FYI). However, meteoric accumulation and redistribution of snow on FYI is highly stochastic over space and time, which makes it poorly understood. Previous studies have estimated local-scale snow thickness distributions using in-situ technique and modelling but it is spatially limited and challenging due to logistic difficulties. Moreover, snow albedo is also critical for determining the surface energy balance of the OSA during the critical summer ablation season. Even then, due to persistent and widespread cloud cover in the Arctic at various spatio-temporal scales, it is difficult and unreliable to remotely measure albedo of snow cover on FYI in the optical spectrum. Previous studies demonstrate that only large-scale sea ice albedo was successfully estimated using optical-satellite sensors. However, space-borne microwave sensors, with their capability of all-weather and 24-hour imaging, can provide enhanced information about snow cover on FYI. Daily spaceborne C-band scatterometer data (ASCAT) and MODIS data are used to investigate the the seasonal co-evolution of the microwave backscatter coefficient and optical albedo as a function of snow thickness on smooth FYI. The research focuses on snow-covered FYI near Cambridge Bay, Nunavut (Fig.1) during the winter to advanced-melt period (April-June, 2014). The ACSAT time series (Fig.2) show distinct increase in scattering at melt onset indicating the first occurrence of melt water in the snow cover. The corresponding albedo exhibits no decrease at this stage. We show how the standard deviation of ASCAT backscatter on FYI during winter can be used as a proxy for surface roughness

  14. Optical observations of the nearby galaxy IC342 with narrow band [SII] and hα filters. II - detection of 16 optically-identified supernova remnant candidates

    Directory of Open Access Journals (Sweden)

    Vučetić M.M.

    2015-01-01

    Full Text Available We present the detection of 16 optical supernova remnant (SNR candidates in the nearby spiral galaxy IC342. The candidates were detected by applying the [Sii]/Hα ratio criterion on observations made with the 2 m RCC telescope at Rozhen National Astronomical Observatory in Bulgaria. In this paper, we report the coordinates, diameters, Hα and [S ii] fluxes for 16 SNRs detected in two fields of view in the IC342 galaxy. Also, we estimate the contamination of total Hα flux from SNRs in the observed portion of IC342 to be 1.4%. This would represent the fractional error when the star formation rate (SFR for this galaxy is derived from the total galaxy’s Hα emission.

  15. Congenital Constriction Band Syndrome

    OpenAIRE

    Rajesh Gupta, Fareed Malik, Rishabh Gupta, M.A.Basit, Dara Singh

    2008-01-01

    Congenital constriction bands are anomalous bands that encircle a digit or an extremity. Congenitalconstriction band syndrome is rare condition and is mostly associated with other musculoskeletaldisorders.We report such a rare experience.

  16. Dust bands in the asteroid belt

    International Nuclear Information System (INIS)

    Sykes, M.V.; Greenberg, R.; Dermott, S.F.; Nicholson, P.D.; Burns, J.A.

    1989-01-01

    This paper describes the original IRAS observations leading to the discovery of the three dust bands in the asteroid belt and the analysis of data. Special attention is given to an analytical model of the dust band torus and to theories concerning the origin of the dust bands, with special attention given to the collisional equilibrium (asteroid family), the nonequilibrium (random collision), and the comet hypotheses of dust-band origin. It is noted that neither the equilibrium nor nonequilibrium models, as currently formulated, present a complete picture of the IRAS dust-band observations. 32 refs

  17. The 3 micron ice band

    International Nuclear Information System (INIS)

    Greenberg, J.M.; Bult, C.E.P.M. van de

    1984-01-01

    Ever since it was proposed that H 2 O could be a dominant constituent of interstellar grains, its detection, or lack thereof, has played a large role in theories of grains and their evolution. It now appears possible to provide a basic theoretical structure for the evolution of grains in molecular clouds based on current observational evidence and laboratory experiments on the ice band. Both band strengths and shapes can be reasonably predicted by grain models. (U.K.)

  18. TIME-RESOLVED EMISSION FROM BRIGHT HOT PIXELS OF AN ACTIVE REGION OBSERVED IN THE EUV BAND WITH SDO/AIA AND MULTI-STRANDED LOOP MODELING

    Energy Technology Data Exchange (ETDEWEB)

    Tajfirouze, E.; Reale, F.; Petralia, A. [Dipartimento di Fisica e Chimica, Università di Palermo, Piazza del Parlamento 1, I-90134 (Italy); Testa, P., E-mail: aastex-help@aas.org [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

    2016-01-01

    Evidence of small amounts of very hot plasma has been found in active regions and might be an indication of impulsive heating released at spatial scales smaller than the cross-section of a single loop. We investigate the heating and substructure of coronal loops in the core of one such active region by analyzing the light curves in the smallest resolution elements of solar observations in two EUV channels (94 and 335 Å) from the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory. We model the evolution of a bundle of strands heated by a storm of nanoflares by means of a hydrodynamic 0D loop model (EBTEL). The light curves obtained from a random combination of those of single strands are compared to the observed light curves either in a single pixel or in a row of pixels, simultaneously in the two channels, and using two independent methods: an artificial intelligent system (Probabilistic Neural Network) and a simple cross-correlation technique. We explore the space of the parameters to constrain the distribution of the heat pulses, their duration, their spatial size, and, as a feedback on the data, their signatures on the light curves. From both methods the best agreement is obtained for a relatively large population of events (1000) with a short duration (less than 1 minute) and a relatively shallow distribution (power law with index 1.5) in a limited energy range (1.5 decades). The feedback on the data indicates that bumps in the light curves, especially in the 94 Å channel, are signatures of a heating excess that occurred a few minutes before.

  19. Multiwavelength Observations of the Powerful Gamma-ray Quasar PKS 1510-089: Clues on the Jet Composition

    Energy Technology Data Exchange (ETDEWEB)

    Kataoka, J.; Madejski, G.; Sikora, M.; Roming, P.; Chester, M.M.; Grupe, D.; Tsubuku, Y.; Sato, R.; Kawai, N.; Tosti, G.; Impiombato, D.; Kovalev, Y.Y.; Kovalev, Y.A.; Edwards, Philip G.; Wagner, S.J.; Moderski, R.; Stawarz, L.; Takahashi, T.; Watanabe, S.

    2007-09-28

    We present the results from a multiwavelength campaign conducted in August 2006 of the powerful {gamma}-ray quasar PKS 1510--089 (z = 0.361). This campaign commenced with a deep Suzaku observation lasting three days for a total exposure time of 120 ks, and continued with Swift monitoring over 18 days. Besides Swift observations, which sampled the optical/UV flux in all 6 UVOT filters as well as the X-ray spectrum in the 0.3--10 keV energy range, the campaign included ground-based optical and radio data, and yielded a quasi-simultaneous broad-band spectral energy distribution from 109 Hz to 1019 Hz. Thanks to its low instrumental background, the Suzaku observation provided a high S/N X-ray spectrum, which is well represented by an extremely hard power-law with photon index {Gamma}{approx_equal}1.2, augmented by a soft component apparent below 1 keV, which is well described by a black-body model with temperature kT {approx_equal}0.2 keV. Monitoring by Suzaku revealed temporal variability which is different between the low and high energy bands, again suggesting the presence of a second, variable component in addition to the primary power-law emission. We model the broadband spectrum of PKS 1510--089 assuming that the high energy spectral component results from Comptonization of infrared radiation produced by hot dust located in the surrounding molecular torus. In the adopted internal shock scenario, the derived model parameters imply that the power of the jet is dominated by protons but with a number of electrons/positrons exceeding a number of protons by a factor {approx} 10. We also find that inhomogeneities responsible for the shock formation, prior to the collision may produce bulk-Compton radiation which can explain the observed soft X-ray excess and possible excess at {approx} 18 keV. We note, however, that the bulk-Compton interpretation is not unique, and the observed soft excess could arise as well via some other processes discussed briefly in the text.

  20. Intruder bands in Z = 51 nuclei

    International Nuclear Information System (INIS)

    LaFosse, D.R.

    1993-01-01

    Recent investigations of h 11/2 proton intruder bands in odd 51 Sb nuclei are reported. In addition to experiments performed at SUNY Stony Brook and Chalk River, data from Early Implementation of GAMMASPHERE (analysis in progress) are presented. In particular, the nuclei 109 Sb and 111 Sb are discussed. Rotational bands based on the πh 11/2 orbital coupled to a 2p2h deformed state of the 50 Sn core have been observed. These bands have been observed to high spin, and in the case of 109 Sb to a rotational frequency of 1.4 MeV, the highest frequency observed in a heavy nucleus. The dynamic moments of inertia in these bands decrease slowly with frequency, suggesting a gradual band termination. The systematics of such bands in 109-119 Sb will be discussed

  1. Band structure of semiconductors

    CERN Document Server

    Tsidilkovski, I M

    2013-01-01

    Band Structure of Semiconductors provides a review of the theoretical and experimental methods of investigating band structure and an analysis of the results of the developments in this field. The book presents the problems, methods, and applications in the study of band structure. Topics on the computational methods of band structure; band structures of important semiconducting materials; behavior of an electron in a perturbed periodic field; effective masses and g-factors for the most commonly encountered band structures; and the treatment of cyclotron resonance, Shubnikov-de Haas oscillatio

  2. Atomic-Monolayer MoS2 Band-to-Band Tunneling Field-Effect Transistor

    KAUST Repository

    Lan, Yann Wen

    2016-09-05

    The experimental observation of band-to-band tunneling in novel tunneling field-effect transistors utilizing a monolayer of MoS2 as the conducting channel is demonstrated. Our results indicate that the strong gate-coupling efficiency enabled by two-dimensional materials, such as monolayer MoS2, results in the direct manifestation of a band-to-band tunneling current and an ambipolar transport.

  3. L-band brightness temperature disaggregation for use with S-band and C-band radiometer data for WCOM

    Science.gov (United States)

    Yao, P.; Shi, J.; Zhao, T.; Cosh, M. H.; Bindlish, R.

    2017-12-01

    There are two passive microwave sensors onboard the Water Cycle Observation Mission (WCOM), which includes a synthetic aperture radiometer operating at L-S-C bands and a scanning microwave radiometer operating from C- to W-bands. It provides a unique opportunity to disaggregate L-band brightness temperature (soil moisture) with S-band C-bands radiometer data. In this study, passive-only downscaling methodologies are developed and evaluated. Based on the radiative transfer modeling, it was found that the TBs (brightness temperature) between the L-band and S-band exhibit a linear relationship, and there is an exponential relationship between L-band and C-band. We carried out the downscaling results by two methods: (1) downscaling with L-S-C band passive measurements with the same incidence angle from payload IMI; (2) downscaling with L-C band passive measurements with different incidence angle from payloads IMI and PMI. The downscaling method with L-S bands with the same incident angle was first evaluated using SMEX02 data. The RMSE are 2.69 K and 1.52 K for H and V polarization respectively. The downscaling method with L-C bands is developed with different incident angles using SMEX03 data. The RMSE are 2.97 K and 2.68 K for H and V polarization respectively. These results showed that high-resolution L-band brightness temperature and soil moisture products could be generated from the future WCOM passive-only observations.

  4. Multiple band structure in 156Er

    International Nuclear Information System (INIS)

    Sunyar, A.W.; Der Mateosian, E.; Kistner, O.C.; Johnson, A.; Lumpkin, A.H.; Thieberger, P.

    1976-01-01

    The 142 Nd( 18 O,4n) 156 Er reaction at 90-95 MeV was used to study 156 Er high-spin states to spin 24. In addition to the background ground-state band, two well developed off-spin side bands, one of each parity, were observed. (Auth.)

  5. Wide Band to ''Double Band'' upgrade

    International Nuclear Information System (INIS)

    Kasper, P.; Currier, R.; Garbincius, P.; Butler, J.

    1988-06-01

    The Wide Band beam currently uses electrons obtained from secondary photon conversions to produce the photon beam incident on the experimental targets. By transporting the positrons produced in these conversions as well as the electrons it is possible to almost double the number of photons delivered to the experiments per primary beam proton. 11 figs

  6. Intestinal malrotation and Ladd's bands in a young child | Gaido ...

    African Journals Online (AJOL)

    Intestinal malrotation and Ladd's bands in a young child. ... East African Medical Journal ... potentially more challenging, as it was not the most typical age for duodenal stenosis due to Ladd's bands, which is often mostly observed earlier in life.

  7. Fluctuation diamagnetism in two-band superconductors

    Science.gov (United States)

    Adachi, Kyosuke; Ikeda, Ryusuke

    2016-04-01

    Anomalously large fluctuation diamagnetism around the superconducting critical temperature has been recently observed in iron selenide (FeSe) [Kasahara et al. (unpublished)]. This indicates that superconducting fluctuations (SCFs) play a more significant role in FeSe, which supposedly has a two-band structure, than in the familiar single-band superconductors. Motivated by the data on FeSe, SCF-induced diamagnetism is examined in a two-band system, on the basis of a phenomenological approach with a Ginzburg-Landau functional. The obtained results indicate that the SCF-induced diamagnetism may be more enhanced than that in a single-band system due to the existence of two distinct fluctuation modes. Such enhancement of diamagnetism unique to a two-band system seems consistent with the large diamagnetism observed in FeSe, though still far from a quantitative agreement.

  8. Deep K-band Observations of TMC-1 with the Green Bank Telescope: Detection of HC7O, Nondetection of HC11N, and a Search for New Organic Molecules

    Science.gov (United States)

    Cordiner, M. A.; Charnley, S. B.; Kisiel, Z.; McGuire, B. A.; Kuan, Y.-J.

    2017-12-01

    The 100 m Robert C. Byrd Green Bank Telescope K-band (KFPA) receiver was used to perform a high-sensitivity search for rotational emission lines from complex organic molecules in the cold interstellar medium toward TMC-1 (cyanopolyyne peak), focussing on the identification of new carbon-chain-bearing species as well as molecules of possible prebiotic relevance. We report a detection of the carbon-chain oxide species HC7O and derive a column density of (7.8+/- 0.9)× {10}11 cm-2. This species is theorized to form as a result of associative electron detachment reactions between oxygen atoms and C7H-, and/or reaction of C6H2 + with CO (followed by dissociative electron recombination). Upper limits are given for the related HC6O, C6O, and C7O molecules. In addition, we obtained the first detections of emission from individual 13C isotopologues of HC7N, and derive abundance ratios HC7N/HCCC13CCCCN = 110 ± 16 and HC7N/HCCCC13CCCN = 96 ± 11, indicative of significant 13C depletion in this species relative to the local interstellar elemental 12C/13C ratio of 60-70. The observed spectral region covered two transitions of HC11N, but emission from this species was not detected, and the corresponding column density upper limit is 7.4× {10}10 {{cm}}-2 (at 95% confidence). This is significantly lower than the value of 2.8× {10}11 {{cm}}-2 previously claimed by Bell et al. and confirms the recent nondetection of HC11N in TMC-1 by Loomis et al. Upper limits were also obtained for the column densities of malononitrile and the nitrogen heterocycles quinoline, isoquinoline, and pyrimidine.

  9. Amniotic constriction bands

    Science.gov (United States)

    ... Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Amniotic band sequence URL of this page: //medlineplus.gov/ency/ ... birth. The baby should be delivered in a medical center that has specialists experienced in caring for babies ... or partial loss of function of a body part. Congenital bands affecting large parts of the body cause the ...

  10. Does the chromatic Mach bands effect exist?

    Science.gov (United States)

    Tsofe, Avital; Spitzer, Hedva; Einav, Shmuel

    2009-06-30

    The achromatic Mach bands effect is a well-known visual illusion, discovered over a hundred years ago. This effect has been investigated thoroughly, mainly for its brightness aspect. The existence of Chromatic Mach bands, however, has been disputed. In recent years it has been reported that Chromatic Mach bands are not perceived under controlled iso-luminance conditions. However, here we show that a variety of Chromatic Mach bands, consisting of chromatic and achromatic regions, separated by a saturation ramp, can be clearly perceived under iso-luminance and iso-brightness conditions. In this study, observers' eye movements were recorded under iso-brightness conditions. Several observers were tested for their ability to perceive the Chromatic Mach bands effect and its magnitude, across different cardinal and non-cardinal Chromatic Mach bands stimuli. A computational model of color adaptation, which predicted color induction and color constancy, successfully predicts this variation of Chromatic Mach bands. This has been tested by measuring the distance of the data points from the "achromatic point" and by calculating the shift of the data points from predicted complementary lines. The results suggest that the Chromatic Mach bands effect is a specific chromatic induction effect.

  11. Band parameters of phosphorene

    International Nuclear Information System (INIS)

    Lew Yan Voon, L C; Wang, J; Zhang, Y; Willatzen, M

    2015-01-01

    Phosphorene is a two-dimensional nanomaterial with a direct band-gap at the Brillouin zone center. In this paper, we present a recently derived effective-mass theory of the band structure in the presence of strain and electric field, based upon group theory. Band parameters for this theory are computed using a first-principles theory based upon the generalized-gradient approximation to the density-functional theory. These parameters and Hamiltonian will be useful for modeling physical properties of phosphorene. (paper)

  12. Infrared diffuse interstellar bands

    Science.gov (United States)

    Galazutdinov, G. A.; Lee, Jae-Joon; Han, Inwoo; Lee, Byeong-Cheol; Valyavin, G.; Krełowski, J.

    2017-05-01

    We present high-resolution (R ˜ 45 000) profiles of 14 diffuse interstellar bands in the ˜1.45 to ˜2.45 μm range based on spectra obtained with the Immersion Grating INfrared Spectrograph at the McDonald Observatory. The revised list of diffuse bands with accurately estimated rest wavelengths includes six new features. The diffuse band at 15 268.2 Å demonstrates a very symmetric profile shape and thus can serve as a reference for finding the 'interstellar correction' to the rest wavelength frame in the H range, which suffers from a lack of known atomic/molecular lines.

  13. Band parameters of phosphorene

    DEFF Research Database (Denmark)

    Lew Yan Voon, L. C.; Wang, J.; Zhang, Y.

    2015-01-01

    Phosphorene is a two-dimensional nanomaterial with a direct band-gap at the Brillouin zone center. In this paper, we present a recently derived effective-mass theory of the band structure in the presence of strain and electric field, based upon group theory. Band parameters for this theory...... are computed using a first-principles theory based upon the generalized-gradient approximation to the density-functional theory. These parameters and Hamiltonian will be useful for modeling physical properties of phosphorene....

  14. CSF oligoclonal banding - slideshow

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/presentations/100145.htm CSF oligoclonal banding - series—Normal anatomy To use the ... 5 out of 5 Overview The cerebrospinal fluid (CSF) serves to supply nutrients to the central nervous ...

  15. Decay of superdeformed bands

    International Nuclear Information System (INIS)

    Carpenter, M.P.; Khoo, T.L.; Lauritsen, T.

    1995-01-01

    One of the major challenges in the study of superdeformation is to directly connect the large number of superdeformed bands now known to the yrast states. In this way, excitation energies, spins and parities can be assigned to the levels in the second well which is essential to establish the collective and single-particle components of these bands. This paper will review some of the progress which has been made to understand the decay of superdeformed bands using the new arrays including the measurement of the total decay spectrum and the establishment of direct one-step decays from the superdeformed band to the yrast line in 194 Hg. 42 refs., 5 figs

  16. Laparoscopic gastric banding

    Science.gov (United States)

    ... eat by making you feel full after eating small amounts of food. After surgery, your doctor can adjust the band ... You will feel full after eating just a small amount of food. The food in the small upper pouch will ...

  17. Warm-Up Activities of Middle and High School Band Directors Participating in State-Level Concert Band Assessments

    Science.gov (United States)

    Ward, Justin P.; Hancock, Carl B.

    2016-01-01

    The purpose of this study was to examine the warm-ups chosen by concert band directors participating in state-level performance assessments. We observed 29 middle and high school bands and coded the frequency and duration of warm-up activities and behaviors. Results indicated that most bands rehearsed music and played scales, long tones, and…

  18. Optical flickering of the symbiotic star CH Cyg

    Science.gov (United States)

    Stoyanov, K. A.; Martí, J.; Zamanov, R.; Dimitrov, V. V.; Kurtenkov, A.; Sánchez-Ayaso, E.; Bujalance-Fernández, I.; Latev, G. Y.; Nikolov, G.

    2018-02-01

    Here we present quasi-simultaneous observations of the flickering of the symbiotic binary star CH Cyg in U, B and V bands. We calculate the flickering source parameters and discuss the possible reason for the flickering cessation in the period 2010-2013.

  19. Decreasing patient identification band errors by standardizing processes.

    Science.gov (United States)

    Walley, Susan Chu; Berger, Stephanie; Harris, Yolanda; Gallizzi, Gina; Hayes, Leslie

    2013-04-01

    Patient identification (ID) bands are an essential component in patient ID. Quality improvement methodology has been applied as a model to reduce ID band errors although previous studies have not addressed standardization of ID bands. Our specific aim was to decrease ID band errors by 50% in a 12-month period. The Six Sigma DMAIC (define, measure, analyze, improve, and control) quality improvement model was the framework for this study. ID bands at a tertiary care pediatric hospital were audited from January 2011 to January 2012 with continued audits to June 2012 to confirm the new process was in control. After analysis, the major improvement strategy implemented was standardization of styles of ID bands and labels. Additional interventions included educational initiatives regarding the new ID band processes and disseminating institutional and nursing unit data. A total of 4556 ID bands were audited with a preimprovement ID band error average rate of 9.2%. Significant variation in the ID band process was observed, including styles of ID bands. Interventions were focused on standardization of the ID band and labels. The ID band error rate improved to 5.2% in 9 months (95% confidence interval: 2.5-5.5; P error rates. This decrease in ID band error rates was maintained over the subsequent 8 months.

  20. A superdeformed band in {sup 142}Sm

    Energy Technology Data Exchange (ETDEWEB)

    Hackman, G; Mullins, J M; Kuehner, J A; Prevost, D; Waddington, J C [McMaster Univ., Hamilton, ON (Canada). Dept. of Physics; Galindo-Uribarri, A; Janzen, V P; Radford, D C; Schmeing, N; Ward, D [Atomic Energy of Canada Ltd., Chalk River, ON (Canada). Chalk River Nuclear Labs.

    1992-08-01

    Observation of {gamma}-{gamma} coincidences from the reaction {sup 124}Sn({sup 24}Mg,6n){sup 142}Sm at 145 MeV indicates the existence of a rotational band with dynamic moment of inertia J{sup (2)} similar to that of the superdeformed band in the isotone {sup 143}Eu. This result is consistent with calculations predicting superdeformed structures in N = 80, Z {approx} 64 nuclei. (author). 8 refs., 4 figs.

  1. Ultra wide band antennas

    CERN Document Server

    Begaud, Xavier

    2013-01-01

    Ultra Wide Band Technology (UWB) has reached a level of maturity that allows us to offer wireless links with either high or low data rates. These wireless links are frequently associated with a location capability for which ultimate accuracy varies with the inverse of the frequency bandwidth. Using time or frequency domain waveforms, they are currently the subject of international standards facilitating their commercial implementation. Drawing up a complete state of the art, Ultra Wide Band Antennas is aimed at students, engineers and researchers and presents a summary of internationally recog

  2. Generalized seniority scheme for bands in odd-A nuclei

    International Nuclear Information System (INIS)

    Gai, M.; Arima, A.; Strottman, D.

    1980-01-01

    The microscopic generalized seniority scheme is applied for the description of bands in odd-A nuclei. A perturbation expansion in terms of the core-particle interaction is performed. The first-order correction for the band head and the first member of the band is discussed. The specific band structure of a given nucleus, as well as the systematic trend of bands, is described in an explicit N-dependent analytical formula. This formula involves a linear dependence on N which arises from the first-order perturbation expansion. This term is shown responsible for the large deviation of the 11/2 - ΔJ=2 band spacing in I isotopes from the spacing of the Te core. All observed band structures of an odd-A nucleus arise from one simple core-particle coupling. Hence decoupled-E2 bands and strongly coupled ΔJ=1 bands, particle or hole bands of low-spin or high-spin orbits, all follow one simple N-dependence. This uniformity of bands is manifested in E2 bands in 53 I isotopes and deltaJ=1 bands in 51 Sb that have the same 52 Te cores. For the calculations a particle-particle force with a large contribution from a g delta force is used with a coupling constant that is deduced from 210 Pb. 1 figure

  3. Band-notched spiral antenna

    Science.gov (United States)

    Jeon, Jae; Chang, John

    2018-03-13

    A band-notched spiral antenna having one or more spiral arms extending from a radially inner end to a radially outer end for transmitting or receiving electromagnetic radiation over a frequency range, and one or more resonance structures positioned adjacent one or more segments of the spiral arm associated with a notch frequency band or bands of the frequency range so as to resonate and suppress the transmission or reception of electromagnetic radiation over said notch frequency band or bands.

  4. Experimental study on the adiabatic shear bands

    International Nuclear Information System (INIS)

    Affouard, J.

    1984-07-01

    Four martensitic steels (Z50CDV5 steel, 28CND8 steel, 35NCDV16 steel and 4340 steel) with different hardness between 190 and 600 Hsub(B) (Brinell hardness), have been studied by means of dynamic compressive tests on split Hopkinson pressure bar. Microscopic observations show that the fracture are associated to the development of adiabatic shear bands (except 4340 steel with 190 Hsub(B) hardness). By means of tests for which the deformation is stopped at predetermined levels, the measurement of shear and hardness inside the band and the matrix indicates the chronology of this phenomenon: first the localization of shear, followed by the formation of adiabatic shear band and ultimatly crack initiation and propagation. These results correlated with few simulations by finite elements have permitted to suggest two mecanisms of deformation leading to the formation of adiabatic shear bands in this specific test [fr

  5. Some general constraints on identical band symmetries

    International Nuclear Information System (INIS)

    Guidry, M.W.; Strayer, M.R.; Wu, C.; Feng, D.H.

    1993-01-01

    We argue on general grounds that nearly identical bands observed for superdeformation and less frequently for normal deformation must be explicable in terms of a symmetry having a microscopic basis. We assume that the unknown symmetry is associated with a Lie algebra generated by terms bilinear in fermion creation and annihilation operators. Observed features of these bands and the general properties of Lie groups are then used to place constraints on acceptable algebras. Additional constraints are placed by assuming that the collective spectrum is associated with a dynamical symmetry, and examining the subgroup structure required by phenomenology. We observe that requisite symmetry cannot be unitary, and that the simplest known group structures consistent with these minimal criteria are associated with the Ginocchio algebras employed in the fermion dynamical symmetry model. However, our arguments are general in nature, and we propose that they imply model-independent constraints on any candidate explanation for identical bands

  6. Band gap and band offset of (GaIn)(PSb) lattice matched to InP

    Science.gov (United States)

    Köhler, F.; Böhm, G.; Meyer, R.; Amann, M.-C.

    2005-07-01

    Metastable (GaxIn1-x)(PySb1-y) layers were grown on (001) InP substrates by gas source molecular beam epitaxy. Low-temperature photoluminescence spectroscopy was applied to these heterostructures and revealed spatially indirect band-to-band recombination of electrons localized in the InP with holes in the (GaxIn1-x)(PySb1-y). In addition, samples with layer thicknesses larger than 100nm showed direct PL across the band gap of (GaxIn1-x)(PySb1-y). Band-gap energies and band offset energies of (GaxIn1-x)(PySb1-y) relative to InP were derived from these PL data. A strong bowing parameter was observed.

  7. Collapse and revival in inter-band oscillations of a two-band Bose-Hubbard model

    Energy Technology Data Exchange (ETDEWEB)

    Ploetz, Patrick; Wimberger, Sandro [Institut fuer Theoretische Physik, Universitaet Heidelberg, Philosophenweg 19, 69120 Heidelberg (Germany); Madronero, Javier, E-mail: ploetz@thphys.uni-heidelberg.d [Physik Department, Technische Universitaet Muenchen, James-Franck-Str. 1, 85748 Garching (Germany)

    2010-04-28

    We study the effect of a many-body interaction on inter-band oscillations in a two-band Bose-Hubbard model with an external Stark force. Weak and strong inter-band oscillations are observed, where the latter arise from a resonant coupling of the bands. These oscillations collapse and revive due to a weak two-body interaction between the atoms. Effective models for oscillations in and out of resonance are introduced that provide predictions for the system's behaviour, particularly for the time scales for the collapse and revival of the resonant inter-band oscillations. (fast track communication)

  8. Observing the semiconducting band-gap alignment of MoS{sub 2} layers of different atomic thicknesses using a MoS{sub 2}/SiO{sub 2}/Si heterojunction tunnel diode

    Energy Technology Data Exchange (ETDEWEB)

    Nishiguchi, Katsuhiko, E-mail: nishiguchi.katsuhiko@lab.ntt.co.jp; Yamaguchi, Hiroshi; Fujiwara, Akira [NTT Basic Research Laboratories, 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198 (Japan); Castellanos-Gomez, Andres; Zant, Herre S. J. van der; Steele, Gary A. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628CJ Delft (Netherlands)

    2015-08-03

    We demonstrate a tunnel diode composed of a vertical MoS{sub 2}/SiO{sub 2}/Si heterostructure. A MoS{sub 2} flake consisting four areas of different thicknesses functions as a gate terminal of a silicon field-effect transistor. A thin gate oxide allows tunneling current to flow between the n-type MoS{sub 2} layers and p-type Si channel. The tunneling-current characteristics show multiple negative differential resistance features, which we interpret as an indication of different conduction-band alignments of the MoS{sub 2} layers of different thicknesses. The presented tunnel device can be also used as a hybrid-heterostructure device combining the advantages of two-dimensional materials with those of silicon transistors.

  9. Band Edge Dynamics and Multiexciton Generation in Narrow Band Gap HgTe Nanocrystals.

    Science.gov (United States)

    Livache, Clément; Goubet, Nicolas; Martinez, Bertille; Jagtap, Amardeep; Qu, Junling; Ithurria, Sandrine; Silly, Mathieu G; Dubertret, Benoit; Lhuillier, Emmanuel

    2018-04-11

    Mercury chalcogenide nanocrystals and especially HgTe appear as an interesting platform for the design of low cost mid-infrared (mid-IR) detectors. Nevertheless, their electronic structure and transport properties remain poorly understood, and some critical aspects such as the carrier relaxation dynamics at the band edge have been pushed under the rug. Some of the previous reports on dynamics are setup-limited, and all of them have been obtained using photon energy far above the band edge. These observations raise two main questions: (i) what are the carrier dynamics at the band edge and (ii) should we expect some additional effect (multiexciton generation (MEG)) as such narrow band gap materials are excited far above the band edge? To answer these questions, we developed a high-bandwidth setup that allows us to understand and compare the carrier dynamics resonantly pumped at the band edge in the mid-IR and far above the band edge. We demonstrate that fast (>50 MHz) photoresponse can be obtained even in the mid-IR and that MEG is occurring in HgTe nanocrystal arrays with a threshold around 3 times the band edge energy. Furthermore, the photoresponse can be effectively tuned in magnitude and sign using a phototransistor configuration.

  10. Search for positive parity bands in 117Xe

    International Nuclear Information System (INIS)

    Liu, Z.; Sun, X.; Zhou, X.; Lei, X.; Zhang, Y.; Jin, H.; Pan, Q.; Guo, Y.; Chen, X.; Luo, Y.; Wen, S.; Yuan, G.; Yang, C.; Luo, W.; Chen, Y.S.; Xing, Z.; Chen, X.Q.

    1995-01-01

    Excited states of 117 Xe were populated via the reaction 28 Si+ 92 Mo at 100-120MeV. More than 40 new γ-transitions and three new positive parity bands have been observed by means of in-beam γ-ray spectroscopy. The previously known νh 11/2 bands were confirmed, and the νg 7/2 favored band was extended up to 47/2 + in which two bandcrossings have been observed at hω=0.33 and 0.44MeV, respectively. The band structures have been discussed by means of TRS and CSM calculations. A newly observed rotational band consisting of five γ-transitions has been considered as the πh 11/2 band of 117 Cs. ((orig.))

  11. High macro rubber band ligature

    Directory of Open Access Journals (Sweden)

    José A. Reis Neto

    2013-07-01

    Full Text Available Purpose: The goal of a rubber band ligature is to promote fibrosis of the submucosa with subsequent fixation of the anal epithelium to the underlying sphincter. Following this principle, a new technique of ligature was developed based on two aspects: 1. macro banding: to have a better fibrosis and fixation by banding a bigger volume of mucosa and 2. higher ligature: to have this fixation at the origin of the hemorrhoidal cushion displacement. Methods: 1634 patients with internal hemorrhoidal disease grade II or III were treated by the technique called high macro rubber band. There was no distinction as to age, gender or race. To perform this technique a new hemorrhoidal device was specially designed with a larger diameter and a bigger capacity for mucosal volume aspiration. It is recommended to utilize a longer and wider anoscope to obtain a better view of the anal canal, which will facilitate the injection of submucosa higher in the anal canal and the insertion of the rubber band device. The hemorrhoidal cushion must be banded higher in the anal canal (4 cm above the pectinate line. It is preferable to treat all the hemorrhoids in one single session (maximum of three areas banded. Results: The analysis was retrospective without any comparison with conventional banding. The period of evaluation extended from one to twelve years. The analysis of the results showed perianal edema in 1.6% of the patients, immediate tenesmus in 0.8%, intense pain (need for parenteral analgesia in 1.6%, urinary retention in 0.1% of the patients and a symptomatic recurrence rate of 4.2%. All patients with symptomatic recurrence were treated with a new session of macro rubber banding. None of the patients developed anal or rectal sepsis. Small post-ligature bleeding was observed only in 0.8% of the patients. Conclusions: The high macro rubber banding technique represents an alternative method for the treatment of hemorrhoidal disease grades II or III, with good

  12. A simple method to produce quasi-simultaneous multiple energy helium implantation

    International Nuclear Information System (INIS)

    Paszti, F.; Fried, M.; Manuaba, A.; Mezey, G.; Kotai, E.; Lohner, T.

    1982-11-01

    If a monoenergetic ion beam is bombarding a target through an absorber foil tilted continuously (i.e. its effective thickness changing continuously), the depth distribution of the implanted ions in the sample depends on the way the absorber is moving. The present paper describes a way of absorber tilting for obtaining a uniform depth distribution and its experimental verification in the case of MeV energy helium ions implanted into aluminium target. (author)

  13. UNVEILING THE NATURE OF IGR J17177-3656 WITH X-RAY, NEAR-INFRARED, AND RADIO OBSERVATIONS

    International Nuclear Information System (INIS)

    Paizis, A.; Nowak, M. A.; Wilms, J.; Chaty, S.; Corbel, S.; Rodriguez, J.; Del Santo, M.; Ubertini, P.; Chini, R.

    2011-01-01

    We report on the first broadband (1-200 keV) simultaneous Chandra-INTEGRAL observations of the recently discovered hard X-ray transient IGR J17177-3656 that took place on 2011 March 22, about two weeks after the source discovery. The source had an average absorbed 1-200 keV flux of about 8 x 10 -10 erg cm -2 s -1 . We extracted a precise X-ray position of IGR J17177-3656, α J2000 = 17 h 17 m 42. s 62, δ J2000 = -36 0 56'04.''5 (90% uncertainty of 0.''6). We also report Swift, near-infrared, and quasi-simultaneous radio follow-up observations. With the multi-wavelength information at hand, we propose IGR J17177-3656 is a low-mass X-ray binary, seen at high inclination, probably hosting a black hole.

  14. Noise exposure in marching bands

    Science.gov (United States)

    Keefe, Joseph

    2005-09-01

    Previous studies involving orchestras have shown that music ensembles can produce hazardous noise levels. There are no similar data for marching bands and pep bands. In order to evaluate the noise levels produced by marching and pep bands, 1/3-octave-band sound-pressure levels were measured while these groups rehearsed and performed. Data were collected while marching with the bands to ensure a realistic environment. Comparing these data to OSHA and NIOSH criteria, marching and pep band exposures often exceed safe values. For typical exposures, OSHA doses range from 11% to 295%, while NIOSH doses range from 35% to 3055%. Exposures that would be considered hazardous in the workplace are common in marching and pep bands; students and band directors should take steps to recognize the risk posed by various instruments and various locations, and should implement hearing conservation efforts.

  15. Nanoindentation hardness of banded Australian sedimentary opal

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, P S; Smallwood, A S; Ray, A S [Department of Chemistry, Material and Forensic Science, University of Technology Sydney, PO Box 123, Broadway, NSW 2007 (Australia); Briscoe, B J; Parsonage, D [Department of Chemical Engineering and Chemical Technology, Imperial College of Science, Technology and Medicine, London, SW7 2AZ (United Kingdom)], E-mail: paul.thomas@uts.edu.au

    2008-04-07

    Nanoindentation hardness data in continuous stiffness mode are reported for banded potch and play of colour opals sourced from Lightning Ridge in New South Wales and Andamooka in South Australia. Despite the significant visible heterogeneities observed and the significant differences in origin and microstructures, as observed by SEM, and subtle differences in the elemental distributions between bands within specimens, little difference was observed in the mechanical properties. Specimens were found to be mechanically homogeneous and values of the hardness and moduli were found to be similar between samples. The creep behaviour of the specimens was also observed to be similar. It was concluded that the similarities in mechanical properties were due to the similarities in the silica morphology of the specimens, formed in similar geological environments, as differences in microstructure and trace element distribution were found not to significantly influence the observed bulk mechanical properties.

  16. Semiconductors bonds and bands

    CERN Document Server

    Ferry, David K

    2013-01-01

    As we settle into this second decade of the twenty-first century, it is evident that the advances in micro-electronics have truly revolutionized our day-to-day lifestyle. The technology is built upon semiconductors, materials in which the band gap has been engineered for special values suitable to the particular application. This book, written specifically for a one semester course for graduate students, provides a thorough understanding of the key solid state physics of semiconductors. It describes how quantum mechanics gives semiconductors unique properties that enabled the micro-electronics revolution, and sustain the ever-growing importance of this revolution.

  17. Study of band structure in 78,80Sr using Triaxial Projected Shell Model

    International Nuclear Information System (INIS)

    Behera, N.; Naik, Z.; Bhat, G.H.; Sheikh, J.A.; Palit, R.; Sun, Y.

    2017-01-01

    The purpose of present work is to carry out a systematic study of the yrast-band and gamma-band structure for the even-even 78-80 Sr nuclei using Triaxial Projected Shell Model (TPSM) approach. These nuclei were chosen because 78 Sr has well developed side band(unassigned configuration) and 80 Sr has well developed band observed experimentally

  18. A comparative cepstral based analysis of simulated and measured S-band and X-band radar Doppler spectra of human motion

    CSIR Research Space (South Africa)

    Van Eeden, WD

    2015-10-01

    Full Text Available targets. It is also shown that, whereas the motion of most body parts of a human target can be observed in the X-band data, only the main torso sway can be observed at S-band. This implies that X-band data is well suited to cepstrum based human motion...

  19. The first multi-wavelength campaign of AXP 4U 0142+61 from radio to hard X-rays

    NARCIS (Netherlands)

    den Hartog, P.R.; Kuiper, L.; Hermsen, W.; Rea, N.; Durant, M.; Stappers, B.; Kaspi, V.M.; Dib, R.

    2007-01-01

    For the first time a quasi-simultaneous multi-wavelength campaign has been performed on an Anomalous X-ray Pulsar from the radio to the hard X-ray band. 4U 0142+61 was an INTEGRAL target for 1 Ms in July 2005. During these observations it was also observed in the X-ray band with Swift and RXTE, in

  20. Observation of the anisotropic Dirac cone in the band dispersion of 112-structured iron-based superconductor Ca{sub 0.9}La{sub 0.1}FeAs{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Z. T.; Li, M. Y.; Fan, C. C.; Yang, H. F.; Liu, J. S.; Wang, Z. [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050 (China); Xing, X. Z.; Zhou, W.; Sun, Y.; Shi, Z. X. [Department of Physics and Key Laboratory of MEMS of the Ministry of Education, Southeast University, Nanjing 211189 (China); Yao, Q. [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050 (China); State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433 (China); Li, W. [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050 (China); State Key Laboratory of Surface Physics, Department of Physics, and Advanced Materials Laboratory, Fudan University, Shanghai 200433 (China); CAS-Shanghai Science Research Center, Shanghai 201203 (China); Shen, D. W., E-mail: dwshen@mail.sim.ac.cn [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology (SIMIT), Chinese Academy of Sciences, Shanghai 200050 (China); CAS-Shanghai Science Research Center, Shanghai 201203 (China); CAS Center for Excellence in Superconducting Electronics (CENSE), Shanghai 200050 (China)

    2016-07-25

    CaFeAs{sub 2} is a parent compound of recently discovered 112-type iron-based superconductors. It is predicted to be a staggered intercalation compound that naturally integrates both quantum spin Hall insulating and superconducting layers and an ideal system for the realization of Majorana modes. We performed a systematical angle-resolved photoemission spectroscopy and first-principles calculation study of the slightly electron-doped CaFeAs{sub 2}. We found that the zigzag As chain of 112-type iron-based superconductors play a considerable role in the low-energy electronic structure, resulting in the characteristic Dirac-cone like band dispersion as the prediction. Our experimental results further confirm that these Dirac cones only exist around the X but not Y points in the Brillouin zone, breaking the S{sub 4} symmetry at iron sites. Our findings present the compelling support to the theoretical prediction that the 112-type iron-based superconductors might host the topological nontrivial edge states. The slightly electron doped CaFeAs{sub 2} would provide us a unique opportunity to realize and explore Majorana fermion physics.

  1. Statistical study of auroral omega bands

    Directory of Open Access Journals (Sweden)

    N. Partamies

    2017-09-01

    Full Text Available The presence of very few statistical studies on auroral omega bands motivated us to test-use a semi-automatic method for identifying large-scale undulations of the diffuse aurora boundary and to investigate their occurrence. Five identical all-sky cameras with overlapping fields of view provided data for 438 auroral omega-like structures over Fennoscandian Lapland from 1996 to 2007. The results from this set of omega band events agree remarkably well with previous observations of omega band occurrence in magnetic local time (MLT, lifetime, location between the region 1 and 2 field-aligned currents, as well as current density estimates. The average peak emission height of omega forms corresponds to the estimated precipitation energies of a few keV, which experienced no significant change during the events. Analysis of both local and global magnetic indices demonstrates that omega bands are observed during substorm expansion and recovery phases that are more intense than average substorm expansion and recovery phases in the same region. The omega occurrence with respect to the substorm expansion and recovery phases is in a very good agreement with an earlier observed distribution of fast earthward flows in the plasma sheet during expansion and recovery phases. These findings support the theory that omegas are produced by fast earthward flows and auroral streamers, despite the rarity of good conjugate observations.

  2. High spin rotational bands in Zn

    Indian Academy of Sciences (India)

    We present here some preliminary results from our studies in the. ~ ¼ region in which we have observed an yrast band structure in Zn extending to spin (41/2 ). ... gaps implies that nuclei may exhibit different shapes at different excitation energies. .... uration, identifying previously unobserved states up to an excitation energy ...

  3. Degenerate band edge laser

    Science.gov (United States)

    Veysi, Mehdi; Othman, Mohamed A. K.; Figotin, Alexander; Capolino, Filippo

    2018-05-01

    We propose a class of lasers based on a fourth-order exceptional point of degeneracy (EPD) referred to as the degenerate band edge (DBE). EPDs have been found in parity-time-symmetric photonic structures that require loss and/or gain; here we show that the DBE is a different kind of EPD since it occurs in periodic structures that are lossless and gainless. Because of this property, a small level of gain is sufficient to induce single-frequency lasing based on a synchronous operation of four degenerate Floquet-Bloch eigenwaves. This lasing scheme constitutes a light-matter interaction mechanism that leads also to a unique scaling law of the laser threshold with the inverse of the fifth power of the laser-cavity length. The DBE laser has the lowest lasing threshold in comparison to a regular band edge laser and to a conventional laser in cavities with the same loaded quality (Q ) factor and length. In particular, even without mirror reflectors the DBE laser exhibits a lasing threshold which is an order of magnitude lower than that of a uniform cavity laser of the same length and with very high mirror reflectivity. Importantly, this novel DBE lasing regime enforces mode selectivity and coherent single-frequency operation even for pumping rates well beyond the lasing threshold, in contrast to the multifrequency nature of conventional uniform cavity lasers.

  4. The Keenan and Wing bands in S stars

    International Nuclear Information System (INIS)

    Lambert, D.L.; Clegg, R.E.S.

    1980-01-01

    New observations of the near infrared spectra of S stars are presented as part of a survey of the unidentified Keenan and Wing bands. Bandhead wavelengths accurate to 0.5 A are presented. A new band is found at 9014 A. The bands are not present in normal M giants and dwarfs. Laboratory spectroscopy of heavy element oxides is reported. Several new identifications are proposed. The 10 300 A Wing band is identified with the Δv = - 1 sequence of the ZrO 9300 A Δv = 0 bands. The ZrO B 1 PI-A 1 Δ (Δv = 0) system may be responsible for either the 9736 A or the 10 515 A Wing bands. Two new bands in the near infrared at 8219 and 8235 A are provided by CeO. A new band with heads at 7503 and 7509 A in a spectrum of R And is tentatively attributed to YS. A band at 8268 A in M stars is the TiO delta(2-1) head. The 8610 A Keenan band is not due to CrH. Potential carriers of the Keenan and Wing bands are reviewed. It is suggested that the heavy element sulphides and, perhaps, chlorides are leading candidates. Identification of YS in R And may provide the first evidence for these sulphides. ZrS is a leading candidate for which laboratory spectroscopy is needed. (author)

  5. Surface Resonance Bands on (001)W: Experimental Dispersion Relations

    DEFF Research Database (Denmark)

    Willis, R. F.; Feuerbacher, B.; Christensen, N. Egede

    1977-01-01

    A band of unbound surface states (resonances), located in an energy region above the vacuum threshold corresponding to an energy band gap in the electron states of the bulk crystal, has been observed by angle-resolved secondary-electron-emission spectroscopy. The experimental dispersion behavior...... is in agreement with the two-dimensional band structure of a clean (001)W surface recently proposed by Smith and Mittheiss....

  6. Identical gamma-vibrational bands in {sup 165}Ho

    Energy Technology Data Exchange (ETDEWEB)

    Radford, D.C.; Galindo-Uribarri, A.; Janzen, V.P. [Chalk River Labs., Ontario (Canada)] [and others

    1996-12-31

    The structure of {sup 165}Ho at moderate spins has been investigated by means of Coulomb excitation. Two {gamma}-vibrational bands (K{sup {pi}} = 11/2{sup {minus}} and K{sup {pi}} = 3/2{sup {minus}}) are observed, with very nearly identical in-band {gamma}-ray energies. Gamma-ray branching ratios are analyzed to extract information on Coriolis mixing, and the role of the K quantum number in identical bands is discussed.

  7. Ka-band waveguide rotary joint

    KAUST Repository

    Yevdokymov, Anatoliy

    2013-04-11

    The authors present a design of a waveguide rotary joint operating in Ka-band with central frequency of 33 GHz, which also acts as an antenna mount. The main unit consists of two flanges with a clearance between them; one of the flanges has three circular choke grooves. Utilisation of three choke grooves allows larger operating clearance. Two prototypes of the rotary joint have been manufactured and experimentally studied. The observed loss is from 0.4 to 0.8 dB in 1.5 GHz band.

  8. Kπ=0+ band moment of inertia anomaly

    International Nuclear Information System (INIS)

    Zeng, J.Y.; Wu, C.S.; Cheng, L.; Lin, C.Z.; China Center of Advanced Science and Technology

    1990-01-01

    The moments of inertia of K π =0 + bands in the well-deformed nuclei are calculated by a particle-number-conserving treatment for the cranked shell model. The very accurate solutions to the low-lying K π =0 + bands are obtained by making use of an effective K truncation. Calculations show that the main contribution to the moments of inertia comes from the nucleons in the intruding high-j orbits. Considering the fact that no free parameter is involved in the calculation and no extra inert core contribution is added, the agreement between the calculated and the observed moments of inertia of 0 + bands in 168 Er is very satisfactory

  9. Wide band ENDOR spectrometer

    International Nuclear Information System (INIS)

    Mendonca Filho, C.

    1973-01-01

    The construction of an ENDOR spectrometer operating from 0,5 to 75 MHz within a single band, with ore Klystron and homodine detection, and no fundamental changes on the electron spin resonance spectrometer was described. The ENDOR signal can be detected both by amplitude modulation of the frequency field, or direct detection of the ESR output, which is taken to a signal analyser. The signal-to-noise ratio is raised by averaging rather than filtering avoiding the use of long time constants, providing natural line widths. The experimental apparatus and the spectra obtained are described. A discussion, relating the ENDOR line amplitudes with the experimental conditions is done and ENDOR mechanism, in which there is a relevant presence of cross relaxation is proposed

  10. Electronic band structure

    International Nuclear Information System (INIS)

    Grosso, G.

    1986-01-01

    The aim of this chapter is to present, in detail, some theoretical methods used to calculate electronic band structures in crystals. The basic strategies employed to attack the problem of electronic-structure calculations are presented. Successive sections present the basic formulations of the tight-binding, orthogonalized-plane-wave, Green'sfunction, and pseudopotential methods with a discussion of their application to perfect solids. Exemplifications in the case of a few selected problems provide further insight by the author into the physical aspects of the different methods and are a guide to the use of their mathematical techniques. A discussion is offered of completely a priori Hartree-Fock calculations and attempts to extend them. Special aspects of the different methods are also discussed in light of recently published related work

  11. Wurtzite gallium phosphide has a direct-band gap

    NARCIS (Netherlands)

    Assali, S.; Zardo, I.; Plissard, S.; Verheijen, M.A.; Haverkort, J.E.M.; Bakkers, E.P.A.M.

    2013-01-01

    Gallium Phosphide (GaP) with the normal cubic crystal structure has an indirect band gap, which severely limits the emission efficiency. We report the fabrication of GaP nanowires with pure hexagonal crystal structure and demonstrate the direct nature of the band gap. We observe strong

  12. Accurate calculation of superdeformed bands in Hg and Pb

    International Nuclear Information System (INIS)

    Lei Yian; Zeng Jinyan

    1993-01-01

    The superdeformed (SD) rotational bands in Hg and Pb are analyzed by means of the abc expression for rotational bands, which was derived from the Bohr Hamiltonian. The agreement between calculated and observed transition energies is incredibly well. The deviation of the calculated E' γ s from the observed results turns out to be absolute value δ ≤0.5 keV (except for a few cases, 0.5 kev ≤ absolute value δ ≤ 0.7 keV). Some transitions which have not been observed yet in these SD bands are also predicted, which may be useful for experimental investigation

  13. Enhancement of phononic band gaps in ternary/binary structure

    International Nuclear Information System (INIS)

    Aly, Arafa H.; Mehaney, Ahmed

    2012-01-01

    Based on the transfer matrix method (TMM) and Bloch theory, the interaction of elastic waves (normal incidence) with 1D phononic crystal had been studied. The transfer matrix method was obtained for both longitudinal and transverse waves by applying the continuity conditions between the consecutive unit cells. Dispersion relations are calculated and plotted for both binary and ternary structures. Also we have investigated the corresponding effects on the band gaps values for the two types of phononic crystals. Furthermore, it can be observed that the complete band gaps are located in the common frequency stop-band regions. Numerical simulations are performed to investigate the effect of different thickness ratios inside each unit cell on the band gap values, as well as unit cells thickness on the central band gap frequency. These phononic band gap materials can be used as a filter for elastic waves at different frequencies values.

  14. Band head spin assignment of superdeformed bands in Hg isotopes through power index formula

    Science.gov (United States)

    Sharma, Honey; Mittal, H. M.

    2018-05-01

    The power index formula has been used to obtain the band head spin (I 0) of all the superdeformed (SD) bands in Hg isotopes. A least squares fitting approach is used. The root mean square deviations between the determined and the observed transition energies are calculated by extracting the model parameters using the power index formula. Whenever definite spins are available, the determined and the observed transition energies are in accordance with each other. The computed values of dynamic moment of inertia J (2) obtained by using the power index formula and its deviation with the rotational frequency is also studied. Excellent agreement is shown between the calculated and the experimental results for J (2) versus the rotational frequency. Hence, the power index formula works very well for all the SD bands in Hg isotopes expect for 195Hg(2, 3, 4).

  15. BROADBAND OBSERVATIONS OF HIGH REDSHIFT BLAZARS

    Energy Technology Data Exchange (ETDEWEB)

    Paliya, Vaidehi S. [Department of Physics and Astronomy, Clemson University, Kinard Lab of Physics, Clemson, SC 29634-0978 (United States); Parker, M. L.; Fabian, A. C. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Stalin, C. S., E-mail: vpaliya@g.clemson.edu [Indian Institute of Astrophysics, Block II, Koramangala, Bangalore-560034 (India)

    2016-07-01

    We present a multi-wavelength study of four high redshift blazars, S5 0014+81 ( z = 3.37), CGRaBS J0225+1846 ( z = 2.69), BZQ J1430+4205 ( z = 4.72), and 3FGL J1656.2−3303 ( z = 2.40) using quasi-simultaneous data from the Swift , Nuclear Spectroscopic Telescope Array ( NuSTAR ) and the Fermi -Large Area Telescope (LAT) and also archival XMM-Newton observations. Other than 3FGL J1656.2−3303, none of the sources were known as γ -ray emitters, and our analysis of ∼7.5 yr of LAT data reveals the first time detection of statistically significant γ -ray emission from CGRaBS J0225+1846. We generate the broadband spectral energy distributions (SED) of all the objects, centering at the epoch of NuSTAR observations and reproduce them using a one-zone leptonic emission model. The optical−UV emission in all the objects can be explained by radiation from the accretion disk, whereas the X-ray to γ -ray windows of the SEDs are found to be dominated by inverse Compton scattering off the broad line region photons. All of them host black holes that are billions of solar masses. Comparing the accretion disk luminosity and the jet power of these sources with a large sample of blazars, we find them to occupy a high disk luminosity–jet power regime. We also investigate the X-ray spectral properties of the sources in detail with a major focus on studying the causes of soft X-ray deficit, a feature generally seen in high redshift radio-loud quasars. We summarize that this feature could be explained based on the intrinsic curvature in the jet emission rather than being due to the external effects predicted in earlier studies, such as host galaxy and/or warm absorption.

  16. Transport in bilayer and trilayer graphene: band gap engineering and band structure tuning

    Science.gov (United States)

    Zhu, Jun

    2014-03-01

    Controlling the stacking order of atomically thin 2D materials offers a powerful tool to control their properties. Linearly dispersed bands become hyperbolic in Bernal (AB) stacked bilayer graphene (BLG). Both Bernal (ABA) and rhombohedral (ABC) stacking occur in trilayer graphene (TLG), producing distinct band structures and electronic properties. A symmetry-breaking electric field perpendicular to the sample plane can further modify the band structures of BLG and TLG. In this talk, I will describe our experimental effort in these directions using dual-gated devices. Using thin HfO2 film deposited by ALD as gate dielectric, we are able to apply large displacement fields D > 6 V/nm and observe the opening and saturation of the field-induced band gap Eg in bilayer and ABC-stacked trilayer graphene, where the conduction in the mid gap changes by more than six decades. Its field and temperature dependence highlights the crucial role played by Coulomb disorder in facilitating hopping conduction and suppressing the effect of Eg in the tens of meV regime. In contrast, mid-gap conduction decreases with increasing D much more rapidly in clean h-BN dual-gated devices. Our studies also show the evolution of the band structure in ABA-stacked TLG, in particular the splitting of the Dirac-like bands in large D field and the signatures of two-band transport at high carrier densities. Comparison to theory reveals the need for more sophisticated treatment of electronic screening beyond self-consistent Hartree calculations to accurately predict the band structures of trilayer graphene and graphenic materials in general.

  17. Report from the banding lab

    Science.gov (United States)

    Tautin, J.

    1995-01-01

    Mr. Tautin reported on the seemingly everchanging structure of biological science units within the Interior Department. Current Congressional proposals would either change the name of the Bird Banding Lab's parent agency or make it part of the Geological Survey. The current Congress has not looked favorably on science budgets within the Interior Department, and the Banding Lab's budget is being squeezed ever tighter.

  18. Precipitation Estimation Using L-Band and C-Band Soil Moisture Retrievals

    Science.gov (United States)

    Koster, Randal D.; Brocca, Luca; Crow, Wade T.; Burgin, Mariko S.; De Lannoy, Gabrielle J. M.

    2016-01-01

    An established methodology for estimating precipitation amounts from satellite-based soil moisture retrievals is applied to L-band products from the Soil Moisture Active Passive (SMAP) and Soil Moisture and Ocean Salinity (SMOS) satellite missions and to a C-band product from the Advanced Scatterometer (ASCAT) mission. The precipitation estimates so obtained are evaluated against in situ (gauge-based) precipitation observations from across the globe. The precipitation estimation skill achieved using the L-band SMAP and SMOS data sets is higher than that obtained with the C-band product, as might be expected given that L-band is sensitive to a thicker layer of soil and thereby provides more information on the response of soil moisture to precipitation. The square of the correlation coefficient between the SMAP-based precipitation estimates and the observations (for aggregations to approximately100 km and 5 days) is on average about 0.6 in areas of high rain gauge density. Satellite missions specifically designed to monitor soil moisture thus do provide significant information on precipitation variability, information that could contribute to efforts in global precipitation estimation.

  19. Strongly coupled band in 140Gd

    International Nuclear Information System (INIS)

    Falla-Sotelo, F.; Oliveira, J.R.B.; Rao, M.N.

    2005-01-01

    Several high-K states are known to exist in the mass 130-140 region. For the N=74 even-even isotopes, Kπ = 8 - isomers, with lifetimes ranging from ns to ms, are known in 128 Xe, 130 Ba, 132 Ce, 134 Nd, 136 Sm, and 138 Gd[. In 140 Gd, we have observed for the first time a band also based on an Iπ = 8 - state. This could be the first case of a Kπ = 8 - state observed in an N=76 even-even isotope. The systematics of the Kπ = 8 - isomeric states in N=74 isotopes has been studied by A.M. Bruce et al. These states decay towards the K = 0 ground state band, and the transitions are K-forbidden. The 140 Gd case presents strong similarities but also some significant differences with relation to the N=74 isotopes. We propose the same configuration but with larger deformation in 140 Gd

  20. Dual-band infrared camera

    Science.gov (United States)

    Vogel, H.; Schlemmer, H.

    2005-10-01

    Every year, numerous accidents happen on European roads due to bad visibility (fog, night, heavy rain). Similarly, the dramatic aviation accidents of year 2001 in Milan and Zurich have reminded us that aviation safety is equally affected by reduced visibility. A dual-band thermal imager was developed in order to raise human situation awareness under conditions of reduced visibility especially in the automotive and aeronautical context but also for all transportation or surveillance tasks. The chosen wavelength bands are the Short Wave Infrared SWIR and the Long Wave Infrared LWIR band which are less obscured by reduced visibility conditions than the visible band. Furthermore, our field tests clearly show that the two different spectral bands very often contain complementary information. Pyramidal fusion is used to integrate complementary and redundant features of the multi-spectral images into a fused image which can be displayed on a monitor to provide more and better information for the driver or pilot.

  1. Collective oblate bands in Pb nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Huebel, H; Baldsefen, G; Mehta, D [Bonn Univ. (Germany). Inst. fuer Strahlen- und Kernphysik; and others

    1992-08-01

    The coexistence of different nuclear shapes is a well established phenomenon in the Hg-Pb region, where spherical, oblate, prolate and superdeformed prolate shapes have been observed. In this work, the authors report on several new rotational bands in the normally spherical nuclei {sup 199-201}Pb. Similar structures were found previously in the lighter isotopes {sup 197,198}Pb. 11 refs., 1 tab., 3 figs.

  2. Systematic description of superdeformed bands in the mass-190 region

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yang; Guidry, M. [Oak Ridge National Lab., TN (United States)]|[Univ. of Tennessee, Knoxville, TN (United States); Zhang, Jing-ye [Univ. of Tennessee, Knoxville, TN (United States)

    1996-12-31

    Superdeformed bands for the mass-190 region are described by the Projected Shell Model. Even-even, odd mass and odd-odd nuclei are equally well described. Good agreement with available data for all isotopes studied is obtained. The authors calculation of electromagnetic properties and pairing correlations provides an understanding of the observed gradual increase of dynamical moments of inertia with angular momentum observed in many bands in this mass region.

  3. VIBRONIC PROGRESSIONS IN SEVERAL DIFFUSE INTERSTELLAR BANDS

    International Nuclear Information System (INIS)

    Duley, W. W.; Kuzmin, Stanislav

    2010-01-01

    A number of vibronic progressions based on low-energy vibrational modes of a large molecule have been found in the diffuse interstellar band (DIB) spectrum of HD 183143. Four active vibrational modes have been identified with energies at 5.18 cm -1 , 21.41 cm -1 , 31.55 cm -1 , and 34.02 cm -1 . The mode at 34.02 cm -1 was previously recognized by Herbig. Four bands are associated with this molecule, with origins at 6862.61 A, 6843.64 A, 6203.14 A, and 5545.11 A (14589.1 cm -1 , 14608.08 cm -1 , 16116.41 cm -1 , and 18028.9 cm -1 , respectively). The progressions are harmonic and combination bands are observed involving all modes. The appearance of harmonic, rather than anharmonic, terms in these vibronic progressions is consistent with torsional motion of pendant rings, suggesting that the carrier is a 'floppy' molecule. Some constraints on the type and size of the molecule producing these bands are discussed.

  4. Deep-Space Ka-Band Flight Experience

    Science.gov (United States)

    Morabito, D. D.

    2017-11-01

    Lower frequency bands have become more congested in allocated bandwidth as there is increased competition between flight projects and other entities. Going to higher frequency bands offers significantly more bandwidth, allowing for the use of much higher data rates. However, Ka-band is more susceptible to weather effects than lower frequency bands currently used for most standard downlink telemetry operations. Future or prospective flight projects considering deep-space Ka-band (32-GHz) telemetry data links have expressed an interest in understanding past flight experience with received Ka-band downlink performance. Especially important to these flight projects is gaining a better understanding of weather effects from the experience of current or past missions that operated Ka-band radio systems. We will discuss the historical flight experience of several Ka-band missions starting from Mars Observer in 1993 up to present-day deep-space missions such as Kepler. The study of historical Ka-band flight experience allows one to recommend margin policy for future missions. Of particular interest, we will review previously reported-on flight experience with the Cassini spacecraft Ka-band radio system that has been used for radio science investigations as well as engineering studies from 2004 to 2015, when Cassini was in orbit around the planet Saturn. In this article, we will focus primarily on the Kepler spacecraft Ka-band link, which has been used for operational telemetry downlink from an Earth trailing orbit where the spacecraft resides. We analyzed the received Ka-band signal level data in order to characterize link performance over a wide range of weather conditions and as a function of elevation angle. Based on this analysis of Kepler and Cassini flight data, we found that a 4-dB margin with respect to adverse conditions ensures that we achieve at least a 95 percent data return.

  5. Terra MODIS Band 27 Electronic Crosstalk Effect and Its Removal

    Science.gov (United States)

    Sun, Junqiang; Xiong, Xiaoxiong; Madhavan, Sriharsha; Wenny, Brian

    2012-01-01

    The MODerate-resolution Imaging Spectroradiometer (MODIS) is one of the primary instruments in the NASA Earth Observing System (EOS). The first MODIS instrument was launched in December, 1999 on-board the Terra spacecraft. MODIS has 36 bands, covering a wavelength range from 0.4 micron to 14.4 micron. MODIS band 27 (6.72 micron) is a water vapor band, which is designed to be insensitive to Earth surface features. In recent Earth View (EV) images of Terra band 27, surface feature contamination is clearly seen and striping has become very pronounced. In this paper, it is shown that band 27 is impacted by electronic crosstalk from bands 28-30. An algorithm using a linear approximation is developed to correct the crosstalk effect. The crosstalk coefficients are derived from Terra MODIS lunar observations. They show that the crosstalk is strongly detector dependent and the crosstalk pattern has changed dramatically since launch. The crosstalk contributions are positive to the instrument response of band 27 early in the mission but became negative and much larger in magnitude at later stages of the mission for most detectors of the band. The algorithm is applied to both Black Body (BB) calibration and MODIS L1B products. With the crosstalk effect removed, the calibration coefficients of Terra MODIS band 27 derived from the BB show that the detector differences become smaller. With the algorithm applied to MODIS L1B products, the Earth surface features are significantly removed and the striping is substantially reduced in the images of the band. The approach developed in this report for removal of the electronic crosstalk effect can be applied to other MODIS bands if similar crosstalk behaviors occur.

  6. SINGLE-BAND, TRIPLE-BAND, OR MULTIPLE-BAND HUBBARD MODELS

    NARCIS (Netherlands)

    ESKES, H; SAWATZKY, GA

    1991-01-01

    The relevance of different models, such as the one-band t-J model and the three-band Emery model, as a realistic description of the electronic structure of high-T(c) materials is discussed. Starting from a multiband approach using cluster calculations and an impurity approach, the following

  7. Band-to-band transitions, selection rules, effective mass, and excitonic contributions in monoclinic β -Ga2O3

    Science.gov (United States)

    Mock, Alyssa; Korlacki, Rafał; Briley, Chad; Darakchieva, Vanya; Monemar, Bo; Kumagai, Yoshinao; Goto, Ken; Higashiwaki, Masataka; Schubert, Mathias

    2017-12-01

    We employ an eigenpolarization model including the description of direction dependent excitonic effects for rendering critical point structures within the dielectric function tensor of monoclinic β -Ga2O3 yielding a comprehensive analysis of generalized ellipsometry data obtained from 0.75-9 eV. The eigenpolarization model permits complete description of the dielectric response. We obtain, for single-electron and excitonic band-to-band transitions, anisotropic critical point model parameters including their polarization vectors within the monoclinic lattice. We compare our experimental analysis with results from density functional theory calculations performed using the Gaussian-attenuation-Perdew-Burke-Ernzerhof hybrid density functional. We present and discuss the order of the fundamental direct band-to-band transitions and their polarization selection rules, the electron and hole effective mass parameters for the three lowest band-to-band transitions, and their excitonic contributions. We find that the effective masses for holes are highly anisotropic and correlate with the selection rules for the fundamental band-to-band transitions. The observed transitions are polarized close to the direction of the lowest hole effective mass for the valence band participating in the transition.

  8. Higher superdeformed band members in {sup 190}Hg. Evidence for a band interaction

    Energy Technology Data Exchange (ETDEWEB)

    Bearden, I G; Daly, P J [Purdue Univ., Lafayette, IN (United States); Janssens, V F; Carpenter, M P; Ahmad, I; Khoo, T L; Lauritsen, T; Liang, Y [Argonne National Lab., IL (United States); Drigert, M W [Idaho National Engineering Lab., Idaho Falls, ID (United States); Garg, U; Reviol, W [Notre Dame Univ., IN (United States); Wyss, R [Joint Inst. for Heavy Ion Research, Oak Ridge, TN (United States)

    1992-08-01

    The superdeformed band of {sup 190}Hg has been traced up to a frequency {Dirac_h}{omega} {>=} 0.4 MeV by combining data from several experiments. A distinct change in the slope of the dynamic moment of inertia J{sup (2)} vs {Dirac_h}{omega} is observed at {Dirac_h}{omega} 0.32 MeV. This result is interpreted as evidence for a band interaction at the highest frequencies. Possible interpretations are reviewed. (author) 14 refs., 3 figs.

  9. Experimental study of shear bands formation in a granular material

    Directory of Open Access Journals (Sweden)

    Nguyen Thai Binh

    2017-01-01

    Full Text Available We present an experimental investigation of the formation of shear bands in a granular sample submitted to a biaxial test. Our principal result is the direct observation of the bifurcation at the origin of the localization process in the material. At the bifurcation, the shear band is spatially extended: we observe a breaking of symmetry without any sudden localization of the deformation in a narrow band. Our work thus allows to clearly distinguish different phenomena: bifurcation which is a ponctual event which occurs before the peak, localization which is a process that covers a range of deformation of several percents during which the peak occurs and finally stationary shear bands which are well-defined permanent structures that can be observed at the end of the localization process, after the peak.

  10. Band-selective filter in a zigzag graphene nanoribbon.

    Science.gov (United States)

    Nakabayashi, Jun; Yamamoto, Daisuke; Kurihara, Susumu

    2009-02-13

    Electric transport of a zigzag graphene nanoribbon through a steplike potential and a barrier potential is investigated by using the recursive Green's function method. In the case of the steplike potential, we demonstrate numerically that scattering processes obey a selection rule for the band indices when the number of zigzag chains is even; the electrons belonging to the "even" ("odd") bands are scattered only into the even (odd) bands so that the parity of the wave functions is preserved. In the case of the barrier potential, by tuning the barrier height to be an appropriate value, we show that it can work as the "band-selective filter", which transmits electrons selectively with respect to the indices of the bands to which the incident electrons belong. Finally, we suggest that this selection rule can be observed in the conductance by applying two barrier potentials.

  11. Chiral topological excitons in a Chern band insulator

    Science.gov (United States)

    Chen, Ke; Shindou, Ryuichi

    2017-10-01

    A family of semiconductors called Chern band insulators are shown to host exciton bands with nonzero topological Chern integers and chiral exciton edge modes. Using a prototypical two-band Chern insulator model, we calculate a cross-correlation function to obtain the exciton bands and their Chern integers. The lowest exciton band acquires Chern integers such as ±1 and ±2 in the electronic Chern insulator phase. The nontrivial topology can be experimentally observed both by a nonlocal optoelectronic response of exciton edge modes and by a phase shift in the cross-correlation response due to the bulk mode. Our result suggests that magnetically doped HgTe, InAs/GaSb quantum wells, and (Bi,Sb)2Te3 thin films are promising candidates for a platform of topological excitonics.

  12. Deep space propagation experiments at Ka-band

    Science.gov (United States)

    Butman, Stanley A.

    1990-01-01

    Propagation experiments as essential components of the general plan to develop an operational deep space telecommunications and navigation capability at Ka-band (32 to 35 GHz) by the end of the 20th century are discussed. Significant benefits of Ka-band over the current deep space standard X-band (8.4 GHz) are an improvement of 4 to 10 dB in telemetry capacity and a similar increase in radio navigation accuracy. Propagation experiments are planned on the Mars Observer Mission in 1992 in preparation for the Cassini Mission to Saturn in 1996, which will use Ka-band in the search for gravity waves as well as to enhance telemetry and navigation at Saturn in 2002. Subsequent uses of Ka-band are planned for the Solar Probe Mission and the Mars Program.

  13. Superdeformed bands in 130Ce

    International Nuclear Information System (INIS)

    Paul, E.S.; Semple, A.T.; Boston, A.J.; Joss, D.T.; Nolan, P.J.; Shepherd, S.L.

    1997-01-01

    Four superdeformed bands have been assigned to 130 Ce following a high-statistics γ-ray study using the EUROGAM II spectrometer. The strongest band exhibits two distinct backbends which, in one scenario, may be interpreted as crossings between high-j N = 6 neutron orbitals (νi 13/2 ) and low-j N = 4 orbitals (νd 3/2 ) in an unpaired system. (author)

  14. Spectral band discrimination for species observed from hyperspectral remote sensing

    CSIR Research Space (South Africa)

    Dudeni, N

    2009-08-01

    Full Text Available across the spectrum. Spectral matching is often achieved by means of matching algorithms such as the Spectral Angle Mapper (SAM), Spectral information divergence (SID) and mixed measures of SAM and SID using either the tangent or the sine trigonometric...

  15. Intrinsic properties of high-spin band structures in triaxial nuclei

    Science.gov (United States)

    Jehangir, S.; Bhat, G. H.; Sheikh, J. A.; Palit, R.; Ganai, P. A.

    2017-12-01

    The band structures of 68,70Ge, 128,130,132,134Ce and 132,134,136,138Nd are investigated using the triaxial projected shell model (TPSM) approach. These nuclei depict forking of the ground-state band into several s-bands and in some cases, both the lowest two observed s-bands depict neutron or proton character. It was discussed in our earlier work that this anomalous behaviour can be explained by considering γ-bands based on two-quasiparticle configurations. As the parent band and the γ-band built on it have the same intrinsic structure, g-factors of the two bands are expected to be similar. In the present work, we have undertaken a detailed investigation of g-factors for the excited band structures of the studied nuclei and the available data for a few high-spin states are shown to be in fair agreement with the predicted values.

  16. L-Band RFI in Japan

    Science.gov (United States)

    Soldo, Yan; de Matthaeis, Paolo; Le Vine, David M.

    2016-01-01

    In recent years, three instruments have been launched into orbit with the aim of producing global maps of sea surface salinity and soil moisture using the 1400-1427 MHz band: SMOS, Aquarius and SMAP. Although this frequency band is allocated to passive measurements only, RFI (Radio-Frequency Interference) is present in the data of all three missions. On a global scale, the three sensors have observed approximately the same distribution of RFI. Japan is an important exception that has implications for the design of RFI detection algorithms. RFI in Japan is caused by a large number of emitters belonging to the same system (TV receivers) and for this reason some traditional RFI detection strategies detect little to no RFI over Japan. The study of this case has led to an improvement of the approach to detect RFI in Aquarius data.

  17. Observing participating observation

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2011-01-01

    Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming...

  18. Observing participating observation

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    2010-01-01

    Current methodology concerning participating observation in general leaves the act of observation unobserved. Approaching participating observation from systems theory offers fundamental new insights into the topic. Observation is always participation. There is no way to escape becoming...

  19. Proxy magnetometry of the photosphere: why are G-band bright points so bright?

    NARCIS (Netherlands)

    Rutten, R.J.; Kiselman, Dan; Voort, Luc Rouppe van der; Plez, Bertrand

    2000-01-01

    We discuss the formation of G-band bright points in terms of standard uxtube modeling, in particular the 1D LTE models constructed by Solanki and coworkers. Combined with LTE spectral synthesis they explain observed G-band bright point contrasts quite well. The G-band contrast increase over the

  20. First Results of the Sideband-Separating Mixer for ALMA Band 9 Upgrade

    NARCIS (Netherlands)

    Khudchenko, Andrey; Hesper, Ronald; Baryshev, Andrey; Mena, F. Patricio; Gerlofma, Gerrit; Zijlstra, Tony; Klapwijk, Teun M.; Kooi, Jacob W.; Spaans, Marco

    2011-01-01

    Last year, the design and implementation details of a new modular sideband-separating mixer block, intended as an upgrade for the current single-ended ALMA Band 9 mixers, were presented at this conference. In high-frequency observation bands like ALMA Band 9 (600-720 GHz), which is strongly

  1. Retrieval of Wind Speed Using an L-band Synthetic Aperture Radar

    DEFF Research Database (Denmark)

    Monaldo, Frank M.; Thompson, Donald R.; Badger, Merete

    2007-01-01

    Retrieval of wind speed using L-band synthetic aperture radar (SAR) is both an old and new endeavor. Although the Seasat L-band SAR in 1978 was not well calibrated, early results indicated a strong relationship between observed SAR image intensity and wind speed. The JERS-1 L-band SAR had limited...

  2. Introduction to the viewpoint set on shear bands

    International Nuclear Information System (INIS)

    Hutchinson, J.W.

    1984-01-01

    Recent work aimed at improving our understanding of shear banding and flow localization as modes of deformation and failure is summarized in the six viewpoint articles which follow. For the most part, the emphasis here is on the observation and analysis of shear banding in metals, but active efforts are also underway to understand the role of shear bands in the deformation and failure of soils and rocks. There is a tendency to regard shear bands as a failure mode, as indeed they often are. But extensive straining under highly constrained conditions such as rolling can give rise to profuse flow localization into shear bands which can be regarded as microscopic in the sense that their extent is on the scale of the grains rather than the overall dimensions of the block of material being deformed. Hatherly and Malin describe in detail the observation of such bands and emphasize that they should be considered as a mode of deformation under these circumstances. They relate the formation of the bands to microstructural aspects and discuss their role in the development of recrystallization textures. It will be clear from reading the articles in this viewpoint set that the beginnings of a quantitative theory of shear banding is in place. Continued progress will require parallel developments in constitutive theory and experimental observation. Moreover, basic questions remain to be explored related to the spatial development of the shear bands, their mutual interaction, their development into a failure mode, and how these are influenced by factors such as overall deformational constraint, rate of straining, and temperature

  3. Microscopic mechanism of identical multi-quasiparticle bands

    International Nuclear Information System (INIS)

    Lei Yian; Zhao Enguang; Zeng Jinyan

    1997-01-01

    Identical one-quasiparticle and two-quasiparticle bands in neighboring odd-and even-mass nuclei are recognized; The intrinsic structure of identical bands is demonstrated by using the particle-number-conserving (PNC) treatment. The occurrence of almost identical moments of inertia is the result of competition among the shell effect (including shape variation), pairing (anti-alignment) effect and blocking (anti-pairing) effect. The observed moments of inertia of identical multi-quasiparticle bands are reproduced quite well by the PNC calculation

  4. Experimental studies of narrow band effects in the actinides

    Energy Technology Data Exchange (ETDEWEB)

    Brodsky, M.B.

    1976-01-01

    In many actinide metallic systems the f-electrons exhibit band behavior. This is a consequence of direct f-f wave function overlap or hybridization of f-electrons with s-, p-, and d-electrons. The f-bands can be responsible for large electronic densities of states at the Fermi level which may lead to band magnetism of various types. Although the concept of valence instabilities must be approached cautiously especially in the light actinides, it would not be surprising to observe them in the future, especially in Am compounds.

  5. Experimental studies of narrow band effects in the actinides

    International Nuclear Information System (INIS)

    Brodsky, M.B.

    1976-01-01

    In many actinide metallic systems the f-electrons exhibit band behavior. This is a consequence of direct f-f wave function overlap or hybridization of f-electrons with s-, p-, and d-electrons. The f-bands can be responsible for large electronic densities of states at the Fermi level which may lead to band magnetism of various types. Although the concept of valence instabilities must be approached cautiously especially in the light actinides, it would not be surprising to observe them in the future, especially in Am compounds

  6. Multiple triaxial bands and abnormal signature inversion in 7433As

    International Nuclear Information System (INIS)

    Hu, Shi-Peng; Ma, Hai-Liang; Cao, Xue-Peng; Wu, Xiao-Guang; Zhang, Huan-Qiao; Hua, Hui; Sun, Jun-Jie; Sun, Hui-Bin; He, Chuang-Ye; Zheng, Yun; Li, Guang-Sheng; Li, Cong-Bo; Yao, Shun-He; Yu, Bei-Bei; Wang, Jin-Long; Li, Hong-We; Wu, Yi-Heng; Liu, Jia-Jian; Luo, Peng-Wei; Xu, Chuan

    2014-01-01

    Excited states of the odd–odd nucleus 74 As have been investigated via heavy ion fusion evaporation reaction 70 Zn( 7 Li,3n) 74 As at beam energy of 30 MeV. The properties of the positive- and the negative- parity bands can be interpreted in terms of the Cranked Nilsson–Strutinsky (CNS) model calculations which show that the observed bands are built on the triaxial deformed shape. The inversion of the favored and unfavored signature branches observed in the positive-parity bands presents at high spins rather than normal signature inversion occurs at low spins. This phenomenon may be explained as the origin of unpaired band crossing in a highly rotating triaxial nucleus.

  7. Single-Band and Dual-Band Infrared Detectors

    Science.gov (United States)

    Ting, David Z. (Inventor); Gunapala, Sarath D. (Inventor); Soibel, Alexander (Inventor); Nguyen, Jean (Inventor); Khoshakhlagh, Arezou (Inventor)

    2017-01-01

    Bias-switchable dual-band infrared detectors and methods of manufacturing such detectors are provided. The infrared detectors are based on a back-to-back heterojunction diode design, where the detector structure consists of, sequentially, a top contact layer, a unipolar hole barrier layer, an absorber layer, a unipolar electron barrier, a second absorber, a second unipolar hole barrier, and a bottom contact layer. In addition, by substantially reducing the width of one of the absorber layers, a single-band infrared detector can also be formed.

  8. Adhesives for fixed orthodontic bands.

    Science.gov (United States)

    Millett, Declan T; Glenny, Anne-Marie; Mattick, Rye Cr; Hickman, Joy; Mandall, Nicky A

    2016-10-25

    Orthodontic treatment involves using fixed or removable appliances (dental braces) to correct the positions of teeth. It has been shown that the quality of treatment result obtained with fixed appliances is much better than with removable appliances. Fixed appliances are, therefore, favoured by most orthodontists for treatment. The success of a fixed orthodontic appliance depends on the metal attachments (brackets and bands) being attached securely to the teeth so that they do not become loose during treatment. Brackets are usually attached to the front and side teeth, whereas bands (metal rings that go round the teeth) are more commonly used on the back teeth (molars). A number of adhesives are available to attach bands to teeth and it is important to understand which group of adhesives bond most reliably, as well as reducing or preventing dental decay during the treatment period. To evaluate the effectiveness of the adhesives used to attach bands to teeth during fixed appliance treatment, in terms of:(1) how often the bands come off during treatment; and(2) whether they protect the banded teeth against decay during fixed appliance treatment. The following electronic databases were searched: Cochrane Oral Health's Trials Register (searched 2 June 2016), Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 5) in the Cochrane Library (searched 2 June 2016), MEDLINE Ovid (1946 to 2 June 2016) and EMBASE Ovid (1980 to 2 June 2016). We searched ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. Randomised and controlled clinical trials (RCTs and CCTs) (including split-mouth studies) of adhesives used to attach orthodontic bands to molar teeth were selected. Patients with full arch fixed orthodontic appliance(s) who had bands attached to molars were included. All review authors

  9. Cranking model interpretation of weakly coupled bands in Hg isotopes

    International Nuclear Information System (INIS)

    Guttormsen, M.; Huebel, H.

    1982-01-01

    The positive-parity yrast states of the transitional sup(189-198)Hg isotopes are interpreted within the Bengtsson and Frauendorf version of the cranking model. The very sharp backbendings can be explained by small interaction matrix elements between the ground and s-bands. The experimentally observed large aligned angular momenta and the low band-crossing frequencies are well reproduced in the calculations. (orig.)

  10. Atmospheric scanning electron microscope observes cells and tissues in open medium through silicon nitride film.

    Science.gov (United States)

    Nishiyama, Hidetoshi; Suga, Mitsuo; Ogura, Toshihiko; Maruyama, Yuusuke; Koizumi, Mitsuru; Mio, Kazuhiro; Kitamura, Shinichi; Sato, Chikara

    2010-03-01

    Direct observation of subcellular structures and their characterization is essential for understanding their physiological functions. To observe them in open environment, we have developed an inverted scanning electron microscope with a detachable, open-culture dish, capable of 8 nm resolution, and combined with a fluorescence microscope quasi-simultaneously observing the same area from the top. For scanning electron microscopy from the bottom, a silicon nitride film window in the base of the dish maintains a vacuum between electron gun and open sample dish while allowing electrons to pass through. Electrons are backscattered from the sample and captured by a detector under the dish. Cells cultured on the open dish can be externally manipulated under optical microscopy, fixed, and observed using scanning electron microscopy. Once fine structures have been revealed by scanning electron microscopy, their component proteins may be identified by comparison with separately prepared fluorescence-labeled optical microscopic images of the candidate proteins, with their heavy-metal-labeled or stained ASEM images. Furthermore, cell nuclei in a tissue block stained with platinum-blue were successfully observed without thin-sectioning, which suggests the applicability of this inverted scanning electron microscope to cancer diagnosis. This microscope visualizes mesoscopic-scale structures, and is also applicable to non-bioscience fields including polymer chemistry. (c) 2010 Elsevier Inc. All rights reserved.

  11. Topological magnon bands in ferromagnetic star lattice

    International Nuclear Information System (INIS)

    Owerre, S A

    2017-01-01

    The experimental observation of topological magnon bands and thermal Hall effect in a kagomé lattice ferromagnet Cu(1–3, bdc) has inspired the search for topological magnon effects in various insulating ferromagnets that lack an inversion center allowing a Dzyaloshinskii–Moriya (DM) spin–orbit interaction. The star lattice (also known as the decorated honeycomb lattice) ferromagnet is an ideal candidate for this purpose because it is a variant of the kagomé lattice with additional links that connect the up-pointing and down-pointing triangles. This gives rise to twice the unit cell of the kagomé lattice, and hence more interesting topological magnon effects. In particular, the triangular bridges on the star lattice can be coupled either ferromagnetically or antiferromagnetically which is not possible on the kagomé lattice ferromagnets. Here, we study DM-induced topological magnon bands, chiral edge modes, and thermal magnon Hall effect on the star lattice ferromagnet in different parameter regimes. The star lattice can also be visualized as the parent material from which topological magnon bands can be realized for the kagomé and honeycomb lattices in some limiting cases. (paper)

  12. Topological magnon bands in ferromagnetic star lattice.

    Science.gov (United States)

    Owerre, S A

    2017-05-10

    The experimental observation of topological magnon bands and thermal Hall effect in a kagomé lattice ferromagnet Cu(1-3, bdc) has inspired the search for topological magnon effects in various insulating ferromagnets that lack an inversion center allowing a Dzyaloshinskii-Moriya (DM) spin-orbit interaction. The star lattice (also known as the decorated honeycomb lattice) ferromagnet is an ideal candidate for this purpose because it is a variant of the kagomé lattice with additional links that connect the up-pointing and down-pointing triangles. This gives rise to twice the unit cell of the kagomé lattice, and hence more interesting topological magnon effects. In particular, the triangular bridges on the star lattice can be coupled either ferromagnetically or antiferromagnetically which is not possible on the kagomé lattice ferromagnets. Here, we study DM-induced topological magnon bands, chiral edge modes, and thermal magnon Hall effect on the star lattice ferromagnet in different parameter regimes. The star lattice can also be visualized as the parent material from which topological magnon bands can be realized for the kagomé and honeycomb lattices in some limiting cases.

  13. Comparison of eigensolvers for symmetric band matrices.

    Science.gov (United States)

    Moldaschl, Michael; Gansterer, Wilfried N

    2014-09-15

    We compare different algorithms for computing eigenvalues and eigenvectors of a symmetric band matrix across a wide range of synthetic test problems. Of particular interest is a comparison of state-of-the-art tridiagonalization-based methods as implemented in Lapack or Plasma on the one hand, and the block divide-and-conquer (BD&C) algorithm as well as the block twisted factorization (BTF) method on the other hand. The BD&C algorithm does not require tridiagonalization of the original band matrix at all, and the current version of the BTF method tridiagonalizes the original band matrix only for computing the eigenvalues. Avoiding the tridiagonalization process sidesteps the cost of backtransformation of the eigenvectors. Beyond that, we discovered another disadvantage of the backtransformation process for band matrices: In several scenarios, a lot of gradual underflow is observed in the (optional) accumulation of the transformation matrix and in the (obligatory) backtransformation step. According to the IEEE 754 standard for floating-point arithmetic, this implies many operations with subnormal (denormalized) numbers, which causes severe slowdowns compared to the other algorithms without backtransformation of the eigenvectors. We illustrate that in these cases the performance of existing methods from Lapack and Plasma reaches a competitive level only if subnormal numbers are disabled (and thus the IEEE standard is violated). Overall, our performance studies illustrate that if the problem size is large enough relative to the bandwidth, BD&C tends to achieve the highest performance of all methods if the spectrum to be computed is clustered. For test problems with well separated eigenvalues, the BTF method tends to become the fastest algorithm with growing problem size.

  14. Decay from the superdeformed bands in 194Hg

    International Nuclear Information System (INIS)

    Henry, R.G.; Khoo, T.L.; Carpenter, M.P.

    1995-01-01

    Superdeformed bands in 194 H g were studied using the early implementation of Gammasphere. The response functions for the Ge detectors were measured for the first time as part of this experiment. Experiments were performed with both a backed target (where the residue stopped in the Au backing) and a thin target (where the residue recoiled into vacuum). This will permit measurements of the decay times of the quasicontinuum γrays. The spectrum in coincidence with the yrast SD band in 194 Hg reveals the same features as found in the quasicontinuum structure in 192 Hg. These features include: statistical γrays feeding the SD band, a pronounced E2 peak from transitions feeding the SD band, a Ml/E2 bump at low energies that is associated with the last stages of feeding of the superdeformed band, and a quasicontinuous distribution from γrays linking SD and normal states, including a sizable clustering of strength around 1.7 MeV. The remarkable similarity of the spectra coincident with SD bands in 192,194 Hg provides additional support for a statistical process for decay out of the SD states. This similarity contrasts with differences observed in the spectrum coincident with the SD band in the odd-even 191 Hg, confirming the predictions about the role of pairing (in normal states) in influencing the shape of the decay-out spectrum

  15. Decay from the superdeformed bands in {sup 194}Hg

    Energy Technology Data Exchange (ETDEWEB)

    Henry, R.G.; Khoo, T.L.; Carpenter, M.P. [and others

    1995-08-01

    Superdeformed bands in {sup 194}H g were studied using the early implementation of Gammasphere. The response functions for the Ge detectors were measured for the first time as part of this experiment. Experiments were performed with both a backed target (where the residue stopped in the Au backing) and a thin target (where the residue recoiled into vacuum). This will permit measurements of the decay times of the quasicontinuum {gamma}rays. The spectrum in coincidence with the yrast SD band in {sup 194}Hg reveals the same features as found in the quasicontinuum structure in {sup 192}Hg. These features include: statistical {gamma}rays feeding the SD band, a pronounced E2 peak from transitions feeding the SD band, a Ml/E2 bump at low energies that is associated with the last stages of feeding of the superdeformed band, and a quasicontinuous distribution from {gamma}rays linking SD and normal states, including a sizable clustering of strength around 1.7 MeV. The remarkable similarity of the spectra coincident with SD bands in {sup 192,194}Hg provides additional support for a statistical process for decay out of the SD states. This similarity contrasts with differences observed in the spectrum coincident with the SD band in the odd-even {sup 191}Hg, confirming the predictions about the role of pairing (in normal states) in influencing the shape of the decay-out spectrum.

  16. Super rigid nature of super-deformed bands

    International Nuclear Information System (INIS)

    Sharma, Neha; Mittal, H.M.; Jain, A.K.

    2012-01-01

    The phenomenon of high-spin super-deformation represents one of the most remarkable discoveries in nuclear physics. A large number of SD bands have been observed in A = 60, 80, 130, 150, 190 mass regions. The cascades of SD bands are known to be connected by electric quadruple E2 transitions. Because of absence of linking transitions between superdeformed (SD) and normal deformed (ND) levels, the spin assignments of most of these bands carry a minimum uncertainty ≈ 1-2ħ. It was found in an analysis of SD bands in the context of semi classical approach that moment of inertia comes close to the rigid body value in most of the cases. Lack of knowledge of spins has led to an emphasis on the study of dynamical moment of inertia of SD bands and systematic of kinematic moment of inertia has not been examined so far. In this paper, we extract the band moment of inertia J 0 and softness parameter (σ) of all the SD bands corresponding to axes ratio (x) = 1.5 and present their systematic

  17. Secular trends in Cherokee cranial morphology: Eastern vs Western bands.

    Science.gov (United States)

    Sutphin, Rebecca; Ross, Ann H; Jantz, Richard L

    2014-01-01

    The research objective was to examine if secular trends can be identified for cranial data commissioned by Boas in 1892, specifically for cranial breadth and cranial length of the Eastern and Western band Cherokee who experienced environmental hardships. Multiple regression analysis was used to test the degree of relationship between each of the cranial measures: cranial length, cranial breadth and cephalic index, along with predictor variables (year-of-birth, location, sex, admixture); the model revealed a significant difference for all craniometric variables. Additional regression analysis was performed with smoothing Loess plots to observe cranial length and cranial breadth change over time (year-of-birth) separately for Eastern and Western Cherokee band females and males born between 1783-1874. This revealed the Western and Eastern bands show a decrease in cranial length over time. Eastern band individuals maintain a relatively constant head breadth, while Western Band individuals show a sharp decline beginning around 1860. These findings support negative secular trend occurring for both Cherokee bands where the environment made a detrimental impact; this is especially marked with the Western Cherokee band.

  18. 47 CFR 90.531 - Band plan.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Band plan. 90.531 Section 90.531...-805 MHz Bands § 90.531 Band plan. This section sets forth the band plan for the 763-775 MHz and 793... and portables subject to Commission-approved regional planning committee regional plans. Transmitter...

  19. Metaphyseal bands in osteogenesis imperfecta

    Directory of Open Access Journals (Sweden)

    Suresh S

    2010-01-01

    Full Text Available An increasing number of patients with osteogenesis imperfecta are undergoing pamidronate therapy to prevent the incidence of fragility fractures. The authors herein report a child aged 3 years who received five cycles of pamidronate, resulting in metaphyseal bands, known as "zebra lines."

  20. Metaphyseal bands in osteogenesis imperfecta

    International Nuclear Information System (INIS)

    Suresh, SS; Thomas, John K

    2010-01-01

    An increasing number of patients with osteogenesis imperfecta are undergoing pamidronate therapy to prevent the incidence of fragility fractures. The authors herein report a child aged 3 years who received five cycles of pamidronate, resulting in metaphyseal bands, known as “zebra lines.”

  1. Mars Global Surveyor Ka-Band Frequency Data Analysis

    Science.gov (United States)

    Morabito, D.; Butman, S.; Shambayati, S.

    2000-01-01

    for the feed and electronics equipment. A dichroic plate is used to reflect the X-band energy and pass the Ka-band energy to another mirror. The RF energy for each band is then focused onto a feed horn and low-noise amplifier package. After amplification and RF/IF downconversion, the IF signals are sent to the Experimental Tone Tracker (ETT), a digital phase-lock-loop receiver, which simultaneously tracks both X-band and Ka-band carrier signals. Once a signal is detected, the ETT outputs estimates of the SNR in a I -Hz bandwidth (Pc/No), baseband phase and frequency of the signals every I -sec. Between December 1996 and December 1998, the Ka-band and X-band signals from MGS were tracked on a regular basis using the ETT. The Ka-band downlink frequencies described here were referenced to the spacecraft's on-board USO which was also the X-band frequency reference (fka= 3.8 fx). The ETT estimates of baseband phase at I -second sampled time tags were converted to sky frequency estimates. Frequency residuals were then generated for each band by removing a model frequency from each observable frequency at each time tag. The model included Doppler and other effects derived from spacecraft trajectory files obtained from the MGS Navigation Team. A simple troposphere correction was applied to the data. In addition to residuals, the USO frequencies emitted by the spacecraft were estimated. For several passes, the USO frequencies were determined from X-band data and from Ka-band data (referred to X-band by dividing by 3.8) and were found to be in good agreement. In addition, X-band USO frequency estimates from MGS Radio Science data acquired from operational DSN stations were available for comparison and were found to agree within the I Hz level. The remaining sub-Hertz differences were attributed to the different models and software algorithms used by MGS Radio Science and KaBLE-11. A summary of the results of a linear fit of the USO frequency versus time (day of year) is

  2. Strongly coupled band in {sup 140}Gd

    Energy Technology Data Exchange (ETDEWEB)

    Falla-Sotelo, F.; Oliveira, J.R.B.; Rao, M.N. [Instituto de Fisica, Universidade de Sao Paulo, Sao Paulo (Brazil)] (and others)

    2005-07-01

    Several high-K states are known to exist in the mass 130-140 region. For the N=74 even-even isotopes, K{pi} = 8{sup -} isomers, with lifetimes ranging from ns to ms, are known in {sup 128}Xe, {sup 130}Ba, {sup 132}Ce, {sup 134}Nd, {sup 136}Sm, and {sup 138}Gd[. In {sup 140}Gd, we have observed for the first time a band also based on an I{pi} = 8{sup -} state. This could be the first case of a K{pi} = 8{sup -} state observed in an N=76 even-even isotope. The systematics of the K{pi} = 8{sup -} isomeric states in N=74 isotopes has been studied by A.M. Bruce et al. These states decay towards the K = 0 ground state band, and the transitions are K-forbidden. The {sup 140}Gd case presents strong similarities but also some significant differences with relation to the N=74 isotopes. We propose the same configuration but with larger deformation in {sup 140}Gd.

  3. Identification of the unfavored N=7 superdeformed band in 191Hg

    International Nuclear Information System (INIS)

    Carpenter, M.P.; Janssens, R.V.F.; Cederwall, B.; Crowell, B.; Ahmad, I.; Becker, J.A.; Brinkman, M.J.; Deleplanque, M.A.; Diamond, R.M.; Fallon, P.; Farris, L.P.; Garg, U.; Gassmann, D.; Henry, E.A.; Henry, R.G.; Hughes, J.R.; Khoo, T.L.; Lauritsen, T.; Lee, I.Y.; Machiavelli, A.O.; Moore, E.F.; Nisius, D.; Stephens, F.S.

    1995-01-01

    A new superdeformed band has been identified in 191 Hg bringing the total number of bands observed in this nucleus to four. The new band has properties similar to those of a superdeformed band reported recently in 193 Hg. Both bands are believed to be built on the unfavored signature of the j 15/2 intruder configuration. Comparisons between the data and cranked Woods-Saxon calculations highlight the strengths and weaknesses of theory in describing high-N orbitals at large deformation

  4. Band-to-Band Misregistration of the Images of MODIS Onboard Calibrators and Its Impact on Calibration

    Science.gov (United States)

    Wang, Zhipeng; Xiong, Xiaoxiong

    2017-01-01

    The Moderate Resolution Imaging Spectroradiometer (MODIS) instruments aboard Terra and Aqua satellites are radiometrically calibrated on-orbit with a set of onboard calibrators (OBCs), including a solar diffuser, a blackbody, and a space view port through which the detectors can view the dark space. As a whisk-broom scanning spectroradiometer, thirty-six MODIS spectral bands are assembled in the along-scan direction on four focal plane assemblies (FPAs). These bands capture images of the same target sequentially with the motion of a scan mirror. Then the images are coregistered onboard by delaying the appropriate band-dependent amount of time, depending on the band locations on the FPA. While this coregistration mechanismis functioning well for the far-field remote targets such as earth view scenes or the moon, noticeable band-to-band misregistration in the along-scan direction has been observed for near field targets, particularly in OBCs. In this paper, the misregistration phenomenon is presented and analyzed. It is concluded that the root cause of the misregistration is that the rotating element of the instrument, the scan mirror, is displaced from the focus of the telescope primary mirror. The amount of the misregistrationis proportional to the band location on the FPA and is inversely proportional to the distance between the target and the scan mirror. The impact of this misregistration on the calibration of MODIS bands is discussed. In particular, the calculation of the detector gain coefficient m1of bands 8-16 (412 nm 870 nm) is improved by up to 1.5% for Aqua MODIS.

  5. Band-to-Band Misregistration of the Images of MODIS On-Board Calibrators and Its Impact to Calibration

    Science.gov (United States)

    Wang, Zhipeng; Xiong, Xiaoxiong

    2017-01-01

    The MODIS instruments aboard Terra and Aqua satellites are radiometrically calibrated on-orbit with a set of onboard calibrators (OBC) including a solar diffuser (SD), a blackbody (BB) and a space view (SV) port through which the detectors can view the dark space. As a whisk-broom scanning spectroradiometer, thirty-six MODIS spectral bands are assembled in the along-scan direction on four focal plane assemblies (FPA). These bands capture images of the same target sequentially with the motion of a scan mirror. Then the images are co-registered on board by delaying appropriate band dependent amount of time depending on the band locations on the FPA. While this co-registration mechanism is functioning well for the "far field" remote targets such as Earth view (EV) scenes or the Moon, noticeable band-to-band misregistration in the along-scan direction has been observed for near field targets, in particular the OBCs. In this paper, the misregistration phenomenon is presented and analyzed. It is concluded that the root cause of the misregistration is that the rotating element of the instrument, the scan mirror, is displaced from the focus of the telescope primary mirror. The amount of the misregistration is proportional to the band location on the FPA and is inversely proportional to the distance between the target and the scan mirror. The impact of this misregistration to the calibration of MODIS bands is discussed. In particular, the calculation of the detector gain coefficient m1 of bands 8-16 (412 nm 870 nm) is improved by up to 1.5% for Aqua MODIS.

  6. Identical and shifted identical bands

    International Nuclear Information System (INIS)

    Dodder, R.S; Jones, E.F.; Hamilton, J.H.

    1997-01-01

    Spontaneous fission of 252 Cm was studied with 72 large Compton suppressed Ge detectors in Gamma sphere. New isotopes 160 Sm and 162 Gd were identified. Through X-ray-γ and γ-γ-γ) coincidence measurements, level energies were established to spins 14 + to 20 + in 152 , 154 156 60 Nd 92 94 96 , 156 , 158 , 160 62 Sm 94 , 96 , 98 , and 160 , 162 64 Gd 96 , 98 . These nuclei exhibit a remarkable variety of identical bands and bands where the energies and moments of inertia are shifted by the same constant amount for every spin state from 2 + to 12 + for various combinations of nuclei differing by 2n, 4n, 2p, 4p, and α

  7. NCenter wide band neutrino beam

    International Nuclear Information System (INIS)

    Stutte, L.G.

    1985-01-01

    This memo describes the physical properties of the currently operating N-Center wide band neutrino beam---commonly called the triplet train, following a past tradition of a triplet lens configuration. In reality, in order to gain a larger momentum acceptance and to minimize the angular divergence of the beam, a quadruplet beam (4 lenses) employing point-to-parallel optics at a central momentum of 300 GeV was built. 6 refs., 13 figs., 1 tab

  8. [Gastric band erosion: Alternative management].

    Science.gov (United States)

    Echaverry-Navarrete, Denis José; Maldonado-Vázquez, Angélica; Cortes-Romano, Pablo; Cabrera-Jardines, Ricardo; Mondragón-Pinzón, Erwin Eduardo; Castillo-González, Federico Armando

    2015-01-01

    Obesity is a public health problem, for which the prevalence has increased worldwide at an alarming rate, affecting 1.7 billion people in the world. To describe the technique employed in incomplete penetration of gastric band where endoscopic management and/or primary closure is not feasible. Laparoscopic removal of gastric band was performed in five patients with incomplete penetrance using Foley catheterization in the perforation site that could lead to the development of a gastro-cutaneous fistula. The cases presented include a leak that required surgical lavage with satisfactory outcome, and one patient developed stenosis 3 years after surgical management, which was resolved endoscopically. In all cases, the penetration site closed spontaneously. Gastric band erosion has been reported in 3.4% of cases. The reason for inserting a catheter is to create a controlled gastro-cutaneous fistula, allowing spontaneous closure. Various techniques have been described: the totally endoscopic, hybrid techniques (endoscopic/laparoscopic) and completely laparoscopic. A technique is described here that is useful and successful in cases where the above-described treatments are not viable. Copyright © 2015. Published by Masson Doyma México S.A.

  9. Characterization of band structure for transverse acoustic phonons in Fibonacci superlattices by a bandedge formalism

    International Nuclear Information System (INIS)

    Hsueh, W J; Chen, R F; Tang, K Y

    2008-01-01

    We present a divergence-free method to determine the characteristics of band structures and projected band structures of transverse acoustic phonons in Fibonacci superlattices. A set of bandedge equations is formulated to solve the band structures for the phonon instead of using the traditional dispersion relation. Numerical calculations show band structures calculated by the present method for the Fibonacci superlattice without numerical instability, which may occur in traditional methods. Based on the present formalism, the band structure for the acoustic phonons has been characterized by closure points and the projected bandgaps of the forbidden bands. The projected bandgaps are determined by the projected band structure, which is characterized by the cross points of the projected bandedges. We observed that the band structure and projected band structure and their characteristics were quite different for different generation orders and the basic layers for the Fibonacci superlattice. In this study, concise rules to determine these characteristics of the band structure and the projected band structure, including the number and the location of closure points of forbidden bands and those of projected bandgaps, in Fibonacci superlattices with arbitrary generation order and basic layers are proposed.

  10. Crosstalk effect and its mitigation in Aqua MODIS middle wave infrared bands

    Science.gov (United States)

    Sun, Junqiang; Madhavan, Sriharsha; Wang, Menghua

    2017-09-01

    The MODerate-resolution Imaging Spectroradiometer (MODIS) is one of the primary instruments in the National Aeronautics and Space Administration (NASA) Earth Observing System (EOS). The first MODIS instrument was launched in December 1999 on-board the Terra spacecraft. A follow on MODIS was launched on an afternoon orbit in 2002 and is aboard the Aqua spacecraft. Both MODIS instruments are very akin, has 36 bands, among which bands 20 to 25 are Middle Wave Infrared (MWIR) bands covering a wavelength range from approximately 3.750 μm to 4.515 μm. It was found that there was severe contamination in these bands early in mission but the effect has not been characterized and mitigated at the time. The crosstalk effect induces strong striping in the Earth View (EV) images and causes significant retrieval errors in the EV Brightness Temperature (BT) in these bands. An algorithm using a linear approximation derived from on-orbit lunar observations has been developed to correct the crosstalk effect and successfully applied to mitigate the effect in both Terra and Aqua MODIS Long Wave Infrared (LWIR) Photovoltaic (PV) bands. In this paper, the crosstalk effect in the Aqua MWIR bands is investigated and characterized by deriving the crosstalk coefficients using the scheduled Aqua MODIS lunar observations for the MWIR bands. It is shown that there are strong crosstalk contaminations among the five MWIR bands and they also have significant crosstalk contaminations from Short Wave Infrared (SWIR) bands. The crosstalk correction algorithm previously developed is applied to correct the crosstalk effect in these bands. It is demonstrated that the crosstalk correction successfully reduces the striping in the EV images and improves the accuracy of the EV BT in the five bands as was done similarly for LWIR PV bands. The crosstalk correction algorithm should thus be applied to improve both the image quality and radiometric accuracy of the Aqua MODIS MWIR bands Level 1B (L1B) products.

  11. Vortex excitations and identical superdeformed bands

    Energy Technology Data Exchange (ETDEWEB)

    Waddington, J C; Bhaduri, R K [McMaster Univ., Hamilton, ON (Canada). Dept. of Physics

    1992-08-01

    Striking relationships exist amongst the transition energies of the identical superdeformed bands (SDB). In this paper, the authors suggest that all of these bands in both the mass 150 and mass 190 regions can be explained as excitations of the specially stable doubly closed shell {sup 152}Dy. Typical of these bands is the case of {sup 153}Dy. Two excited SDB`s were observe which not only have a moment of inertia identical to that of {sup 152}Dy, but the transition energies are shifted by exactly {+-}1/4 of a rotational spacing. It is as though the spin 1/2 of the last neutron had been added directly to the angular momentum of the core, but the mass of this last particle had not contributed to the moment of inertia. The possibility is being investigated that the identical SDBs arise from an equivalent picture under the strong rotation of the specially stable {sup 152}Dy. The rotation renders the 3-dimensional space topologically nontrivial. The moment of inertia of {sup 192}Hg extrapolated to zero spin is identical to that of {sup 152}Dy at high spin. This suggests that a superfluid is formed as particles are added to {sup 152}Dy to make {sup 192}Hg. It is proposed that as the rotational frequency of {sup 192}Hg is increased, quantized vortices are formed, like vortices in superfluid {sup 4}He. These vortices lead to an additional alignment in{sup 192}Hg relative to the {sup 152} core, increasing as I{sup 2}, reaching a value of 4{Dirac_h} at I = 48. 3 refs., 3 figs.

  12. Optical model with multiple band couplings using soft rotator structure

    Science.gov (United States)

    Martyanov, Dmitry; Soukhovitskii, Efrem; Capote, Roberto; Quesada, Jose Manuel; Chiba, Satoshi

    2017-09-01

    A new dispersive coupled-channel optical model (DCCOM) is derived that describes nucleon scattering on 238U and 232Th targets using a soft-rotator-model (SRM) description of the collective levels of the target nucleus. SRM Hamiltonian parameters are adjusted to the observed collective levels of the target nucleus. SRM nuclear wave functions (mixed in K quantum number) have been used to calculate coupling matrix elements of the generalized optical model. Five rotational bands are coupled: the ground-state band, β-, γ-, non-axial- bands, and a negative parity band. Such coupling scheme includes almost all levels below 1.2 MeV of excitation energy of targets. The "effective" deformations that define inter-band couplings are derived from SRM Hamiltonian parameters. Conservation of nuclear volume is enforced by introducing a monopolar deformed potential leading to additional couplings between rotational bands. The present DCCOM describes the total cross section differences between 238U and 232Th targets within experimental uncertainty from 50 keV up to 200 MeV of neutron incident energy. SRM couplings and volume conservation allow a precise calculation of the compound-nucleus (CN) formation cross sections, which is significantly different from the one calculated with rigid-rotor potentials with any number of coupled levels.

  13. HIFI observations of water in the atmosphere of comet C/2008 Q3 (Garradd)

    Science.gov (United States)

    Hartogh, P.; Crovisier, J.; de Val-Borro, M.; Bockelée-Morvan, D.; Biver, N.; Lis, D. C.; Moreno, R.; Jarchow, C.; Rengel, M.; Emprechtinger, M.; Szutowicz, S.; Banaszkiewicz, M.; Bensch, F.; Blecka, M. I.; Cavalié, T.; Encrenaz, T.; Jehin, E.; Küppers, M.; Lara, L.-M.; Lellouch, E.; Swinyard, B. M.; Vandenbussche, B.; Bergin, E. A.; Blake, G. A.; Blommaert, J. A. D. L.; Cernicharo, J.; Decin, L.; Encrenaz, P.; de Graauw, T.; Hutsemekers, D.; Kidger, M.; Manfroid, J.; Medvedev, A. S.; Naylor, D. A.; Schieder, R.; Thomas, N.; Waelkens, C.; Roelfsema, P. R.; Dieleman, P.; Güsten, R.; Klein, T.; Kasemann, C.; Caris, M.; Olberg, M.; Benz, A. O.

    2010-07-01

    High-resolution far-infrared and sub-millimetre spectroscopy of water lines is an important tool to understand the physical and chemical properties of cometary atmospheres. We present observations of several rotational ortho- and para-water transitions in comet C/2008 Q3 (Garradd) performed with HIFI on Herschel. These observations have provided the first detection of the 212-101 (1669 GHz) ortho and 111-000 (1113 GHz) para transitions of water in a cometary spectrum. In addition, the ground-state transition 110-101 at 557 GHz is detected and mapped. By detecting several water lines quasi-simultaneously and mapping their emission we can constrain the excitation parameters in the coma. Synthetic line profiles are computed using excitation models which include excitation by collisions, solar infrared radiation, and radiation trapping. We obtain the gas kinetic temperature, constrain the electron density profile, and estimate the coma expansion velocity by analyzing the map and line shapes. We derive water production rates of 1.7-2.8 × 1028 s-1 over the range rh = 1.83-1.85 AU. Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA.Figure 5 is only available in electronic form at http://www.aanda.org

  14. More on Estimation of Banded and Banded Toeplitz Covariance Matrices

    OpenAIRE

    Berntsson, Fredrik; Ohlson, Martin

    2017-01-01

    In this paper we consider two different linear covariance structures, e.g., banded and bended Toeplitz, and how to estimate them using different methods, e.g., by minimizing different norms. One way to estimate the parameters in a linear covariance structure is to use tapering, which has been shown to be the solution to a universal least squares problem. We know that tapering not always guarantee the positive definite constraints on the estimated covariance matrix and may not be a suitable me...

  15. Glucose Absorption by the Bacillary Band of Trichuris muris.

    Directory of Open Access Journals (Sweden)

    Tina V A Hansen

    2016-09-01

    Full Text Available A common characteristic of Trichuris spp. infections in humans and animals is the variable but low efficacy of single-dose benzimidazoles currently used in mass drug administration programmes against human trichuriasis. The bacillary band, a specialised morphological structure of Trichuris spp., as well as the unique partly intracellular habitat of adult Trichuris spp. may affect drug absorption and perhaps contribute to the low drug accumulation in the worm. However, the exact function of the bacillary band is still unknown.We studied the dependency of adult Trichuris muris on glucose and/or amino acids for survival in vitro and the absorptive function of the bacillary band. The viability of the worms was evaluated using a motility scale from 0 to 3, and the colorimetric assay Alamar Blue was utilised to measure the metabolic activity. The absorptive function of the bacillary band in living worms was explored using a fluorescent glucose analogue (6-NBDG and confocal microscopy. To study the absorptive function of the bacillary band in relation to 6-NBDG, the oral uptake was minimised or excluded by sealing the oral cavity with glue and agarose.Glucose had a positive effect on both the motility (p < 0.001 and metabolic activity (p < 0.001 of T. muris in vitro, whereas this was not the case for amino acids. The 6-NBDG was observed in the pores of the bacillary band and within the stichocytes of the living worms, independent of oral sealing.Trichuris muris is dependent on glucose for viability in vitro, and the bacillary band has an absorptive function in relation to 6-NBDG, which accumulates within the stichocytes. The absorptive function of the bacillary band calls for an exploration of its possible role in the uptake of anthelmintics, and as a potential anthelmintic target relevant for future drug development.

  16. Study of band terminating in the A {approx_equal} 100 by EUROGAM; Recherche de terminaisons de bandes dans la region A {approx_equal} 100 avec EUROGAM

    Energy Technology Data Exchange (ETDEWEB)

    Gizon, J.; Gizon, A.; Genevey, J.; Santos, D. [Inst. des Sciences Nucleaires, Grenoble-1 Univ., 38 (France); Nyako, B.M.; Timar, J.; Zolnai, L. [Institute of Nuclear Research, Debrecen (Hungary); Boston, A.J.; Zoss, D.T.; Paul, E.S.; Semple, A.T. [Oliver Lodge Laboratory, University of Liverpool, Liverpool (United Kingdom); O`Brien, N.J.; Parry, C.M. [Department of Physics, University of York, Heslington, York (United Kingdom); Cata-Danil, Gh.; Bucurescu, D. [Horia Hulubei Institute of Physics and Nuclear Engineering, Bucharest (Romania); Afanasjev, A.V.; Ragnarsson, I. [Department of Mathematical Physics, University of Lund, Lund (Sweden)

    1997-12-31

    Terminating bands in nuclei in the A{approx_equal} 100 region have been investigated using the EUROGAM2 array. Results have been obtained for Pd (Z 46) and Rh (Z = 45) isotopes. In the nucleus {sup 102}Pd, eight terminating configurations are identified. It is the first nucleus where terminating bands built on the valence space configurations and on core excited configurations are observed. Terminating bands have been also found in {sup 103}Pd and {sup 102}Rh. For {sup 102}Rh it is the first case of band terminations identified in a doubly-odd nucleus below the Z = 50 shell closure. (authors) 9 refs., 2 figs.

  17. Microscopic nuclear structure models and methods: chiral symmetry, wobbling motion and γ –bands

    International Nuclear Information System (INIS)

    Sheikh, Javid A; Bhat, Gowhar H; Dar, Waheed A; Jehangir, Sheikh; Ganai, Prince A

    2016-01-01

    A systematic investigation of the nuclear observables related to the triaxial degree of freedom is presented using the multi-quasiparticle triaxial projected shell model (TPSM) approach. These properties correspond to the observation of γ -bands, chiral doublet bands and the wobbling mode. In the TPSM approach, γ -bands are built on each quasiparticle configuration and it is demonstrated that some observations in high-spin spectroscopy that have remained unresolved for quite some time could be explained by considering γ -bands based on two-quasiparticle configurations. It is shown in some Ce-, Nd- and Ge-isotopes that the two observed aligned or s-bands originate from the same intrinsic configuration with one of them as the γ -band based on a two-quasiparticle configuration. In the present work, we have also performed a detailed study of γ -bands observed up to the highest spin in dysposium, hafnium, mercury and uranium isotopes. Furthermore, several measurements related to chiral symmetry breaking and wobbling motion have been reported recently. These phenomena, which are possible only for triaxial nuclei, have been investigated using the TPSM approach. It is shown that doublet bands observed in lighter odd–odd Cs-isotopes can be considered as candidates for chiral symmetry breaking. Transverse wobbling motion recently observed in 135 Pr has also been investigated and it is shown that TPSM approach provides a reasonable description of the measured properties. (invited comment)

  18. Reprint of: Atmospheric scanning electron microscope observes cells and tissues in open medium through silicon nitride film.

    Science.gov (United States)

    Nishiyama, Hidetoshi; Suga, Mitsuo; Ogura, Toshihiko; Maruyama, Yuusuke; Koizumi, Mitsuru; Mio, Kazuhiro; Kitamura, Shinichi; Sato, Chikara

    2010-11-01

    Direct observation of subcellular structures and their characterization is essential for understanding their physiological functions. To observe them in open environment, we have developed an inverted scanning electron microscope with a detachable, open-culture dish, capable of 8 nm resolution, and combined with a fluorescence microscope quasi-simultaneously observing the same area from the top. For scanning electron microscopy from the bottom, a silicon nitride film window in the base of the dish maintains a vacuum between electron gun and open sample dish while allowing electrons to pass through. Electrons are backscattered from the sample and captured by a detector under the dish. Cells cultured on the open dish can be externally manipulated under optical microscopy, fixed, and observed using scanning electron microscopy. Once fine structures have been revealed by scanning electron microscopy, their component proteins may be identified by comparison with separately prepared fluorescence-labeled optical microscopic images of the candidate proteins, with their heavy-metal-labeled or stained ASEM images. Furthermore, cell nuclei in a tissue block stained with platinum-blue were successfully observed without thin-sectioning, which suggests the applicability of this inverted scanning electron microscope to cancer diagnosis. This microscope visualizes mesoscopic-scale structures, and is also applicable to non-bioscience fields including polymer chemistry. Copyright © 2010 Elsevier Inc. All rights reserved.

  19. Band Subset Selection for Hyperspectral Image Classification

    Directory of Open Access Journals (Sweden)

    Chunyan Yu

    2018-01-01

    Full Text Available This paper develops a new approach to band subset selection (BSS for hyperspectral image classification (HSIC which selects multiple bands simultaneously as a band subset, referred to as simultaneous multiple band selection (SMMBS, rather than one band at a time sequentially, referred to as sequential multiple band selection (SQMBS, as most traditional band selection methods do. In doing so, a criterion is particularly developed for BSS that can be used for HSIC. It is a linearly constrained minimum variance (LCMV derived from adaptive beamforming in array signal processing which can be used to model misclassification errors as the minimum variance. To avoid an exhaustive search for all possible band subsets, two numerical algorithms, referred to as sequential (SQ and successive (SC algorithms are also developed for LCMV-based SMMBS, called SQ LCMV-BSS and SC LCMV-BSS. Experimental results demonstrate that LCMV-based BSS has advantages over SQMBS.

  20. The DSS-14 C-band exciter

    Science.gov (United States)

    Rowan, D. R.

    1989-01-01

    The development and implementation of a C-band exciter for use with the Block IV Receiver-Exciter Subsystem at Deep Space Station 14 (DSS-14) has been completed. The exciter supplements the standard capabilities of the Block IV system by providing a drive signal for the C-band transmitter while generating coherent translation frequencies for C-band (5-GHz) to S-band (2.2- to 2.3-GHz) Doppler extraction, C-band to L-band (1.6-GHz) zero delay measurements, and a level calibrated L-band test signal. Exciter functions are described, and a general explanation and description of the C-band uplink controller is presented.

  1. Changing optical band structure with single photons

    Science.gov (United States)

    Albrecht, Andreas; Caneva, Tommaso; Chang, Darrick E.

    2017-11-01

    Achieving strong interactions between individual photons enables a wide variety of exciting possibilities in quantum information science and many-body physics. Cold atoms interfaced with nanophotonic structures have emerged as a platform to realize novel forms of nonlinear interactions. In particular, when atoms are coupled to a photonic crystal waveguide, long-range atomic interactions can arise that are mediated by localized atom-photon bound states. We theoretically show that in such a system, the absorption of a single photon can change the band structure for a subsequent photon. This occurs because the first photon affects the atoms in the chain in an alternating fashion, thus leading to an effective period doubling of the system and a new optical band structure for the composite atom-nanophotonic system. We demonstrate how this mechanism can be engineered to realize a single-photon switch, where the first incoming photon switches the system from being highly transmissive to highly reflective, and analyze how signatures can be observed via non-classical correlations of the outgoing photon field.

  2. Spectra of γ rays feeding superdeformed bands

    International Nuclear Information System (INIS)

    Lauritsen, T.; Khoo, T.L.; Henry, R.G.

    1995-01-01

    The spectrum of γrays coincident with SD transitions contains the transitions which populate the SD band. This spectrum can provide information on the feeding mechanism and on the properties (moment of inertia, collectivity) of excited SD states. We used a model we developed to explain the feeding of SD bands, to calculate the spectrum of feeding γrays. The Monte Carlo simulations take into account the trigger conditions present in our Eurogam experiment. Both experimental and theoretical spectra contain a statistical component and a broad E2 peak (from transitions occurring between excited states in the SD well). There is good resemblance between the measured and calculated spectra although the calculated multiplicity of an E2 bump is low by ∼30%. Work is continuing to improve the quality of the fits, which will result in a better understanding of excited SD states. In addition, a model for the last steps, which cool the γ cascade into the SD yrast line, needs to be developed. A strong M1/E2 low-energy component, which we believe is responsible for this cooling, was observed

  3. Study of intruder band in 112Sn

    International Nuclear Information System (INIS)

    Ganguly, S.; Banerjee, P.; Ray, I.; Kshetri, R.; Raut, R.; Bhattacharya, S.; Saha-Sarkar, M.; Goswami, A.; Mukhopadhyay, S.; Mukherjee, A.; Mukherjee, G.; Basu, S.K.

    2007-01-01

    Excited states of the positive-parity intruder band in 112 Sn, populated in the 100 Mo( 20 Ne,α4n) reaction at a beam energy of 136 MeV, have been studied. The band has been observed up to 11570.0 keV with spin (24 + ). Mean lifetimes have been measured for six states up to the 22 + , 10335.1 keV level and an upper limit of the lifetime has been estimated for the 11570.0 keV (24 + ) state. The B(E2) values, derived from the present lifetime results, correspond to a moderate quadrupole deformation of β 2 ∼0.18 for states with spin J π >=12 + , and the decrease in B(E2) for the 14 + ->12 + transition is consistent with a ν(h 11/2 ) 2 alignment at ω∼0.35 MeV, predicted by a cranked shell-model calculation. Total Routhian surface calculations predict a triaxial shape following the alignment

  4. Spectra of {gamma} rays feeding superdeformed bands

    Energy Technology Data Exchange (ETDEWEB)

    Lauritsen, T.; Khoo, T.L.; Henry, R.G. [and others

    1995-08-01

    The spectrum of {gamma}rays coincident with SD transitions contains the transitions which populate the SD band. This spectrum can provide information on the feeding mechanism and on the properties (moment of inertia, collectivity) of excited SD states. We used a model we developed to explain the feeding of SD bands, to calculate the spectrum of feeding {gamma}rays. The Monte Carlo simulations take into account the trigger conditions present in our Eurogam experiment. Both experimental and theoretical spectra contain a statistical component and a broad E2 peak (from transitions occurring between excited states in the SD well). There is good resemblance between the measured and calculated spectra although the calculated multiplicity of an E2 bump is low by {approximately}30%. Work is continuing to improve the quality of the fits, which will result in a better understanding of excited SD states. In addition, a model for the last steps, which cool the {gamma} cascade into the SD yrast line, needs to be developed. A strong M1/E2 low-energy component, which we believe is responsible for this cooling, was observed.

  5. Thermodynamics of many-band superconductors

    International Nuclear Information System (INIS)

    Waelte, A.

    2006-01-01

    In the present thesis the microscopical properties of the superconducting state of MgCNi 3 , MgB 2 , and some rare earth-transition metal borocarbides are studied by means of measurements of the specific heat. Furthermore the frequency spectrum of the lattice vibrations is estimated. The energy gap of the superconducting state can be determined from the specific heat of the superconducting state, which yields as like as the upper critical mafnetic field H c2 (0) hints on the electron-phonon coupling. From the analysis of these results and the comparison with results from transport measurements as well as the tunnel and point-contact spectroscopy can be concluded, how far the BCS model of superconductivity must be modified in order to be able to describe the superconducting state of the studied compounds. Studies on MgCNi 3 , which lies near a magnetic instability, show that occurring magnetic fluctuations have a bisection of the superconducting transition temperature T C as consequence. The under this aspect relatively high value of T C =7 K is a consequence of strong electron-phonon coupling, which is essentailly carried by nickel vibrations stabilized by carbon. A for the first time observed distinct anomaly in the specific heat of the classical many-band superconductor MgB 2 (here with pure 10 B) at about T c /4=10 K can be understood by means of a two-band model for the case of especially weak coupling between both bands. The analysis of the specific heat of the superconducting phase of the non-magnetic rare earth-nickel borocarbide YNi 2 B 2 C and LuNi 2 B 2 C leads to the conclusion thet visible effects of the many-band electron system are dependent on the mass on the position both of the rare earth and the transition metal. The signal of the superconducting phase transformation visible in the specific heat of the antiferromagnetic HoNi 2 B 2 C is smaller than expected

  6. Study of rotational band in 111Sn

    International Nuclear Information System (INIS)

    Ganguly, S.; Banerjee, P.; Ray, I.; Kshetri, R.; Raut, R.; Goswami, A.; Saha Sarkar, M.; Bhattacharya, S.; Mukherjee, A.; Mukherjee, G.; Basu, S.K.; Mukhopadhyay, S.

    2006-01-01

    The motivation of the present work is to study the negative-parity rotational band in 111 Sn. Study of the lifetimes of the states of the rotational band is expected to provide information on their structures as well as the band termination phenomenon

  7. Prenatal diagnosis of amniotic band syndrome

    Directory of Open Access Journals (Sweden)

    Laxmi Devi Padmanabhan

    2016-01-01

    Full Text Available Amniotic band can cause a broad spectrum of anomalies ranging from simple band constrictions to major craniofacial and visceral defects. It can cause significant neonatal morbidity. Accurate diagnosis will help in the management of the present pregnancy and in counseling with regard to future pregnancies. Here we report three cases of amniotic band syndrome detected in the prenatal period.

  8. Complex band structure and electronic transmission eigenchannels

    DEFF Research Database (Denmark)

    Jensen, Anders; Strange, Mikkel; Smidstrup, Soren

    2017-01-01

    and complex band structure, in this case individual eigenchannel transmissions and different complex bands. We present calculations of decay constants for the two most conductive states as determined by complex band structure and standard DFT Landauer transport calculations for one semi-conductor and two...

  9. High-energy band structure of gold

    DEFF Research Database (Denmark)

    Christensen, N. Egede

    1976-01-01

    The band structure of gold for energies far above the Fermi level has been calculated using the relativistic augmented-plane-wave method. The calculated f-band edge (Γ6-) lies 15.6 eV above the Fermi level is agreement with recent photoemission work. The band model is applied to interpret...

  10. Multi-band Modelling of Appearance

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Larsen, Rasmus

    2003-01-01

    the appearance of both derived feature bands and an intensity band. As a special case of feature-band augmented appearance modelling we propose a dedicated representation with applications to face segmentation. The representation addresses a major problem within face recognition by lowering the sensitivity...

  11. Multi-band Modelling of Appearance

    DEFF Research Database (Denmark)

    Stegmann, Mikkel Bille; Larsen, Rasmus

    2002-01-01

    the appearance of both derived feature bands and an intensity band. As a special case of feature-band augmented appearance modelling we propose a dedicated representation with applications to face segmentation. The representation addresses a major problem within face recognition by lowering the sensitivity...

  12. A Sideband-Separating Mixer Upgrade for ALMA Band 9

    NARCIS (Netherlands)

    Hesper, R.; Gerlofsma, G.; Mena, P.; Spaans, M.; Baryshev, A.

    2009-01-01

    The ALMA band 9 (600-720 GHz) receiver cartridge, as currently being produced, features two single-ended (dual sideband) SIS mixers in orthogonal polarisations. In the case of spectral line observations in the presence of atmospheric backgound, the integration time to reach a certain desired signal

  13. Simply folded band chaos in a VHF microstrip oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Blakely, Jonathan N. [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States)]. E-mail: jonathan.blakely@us.army.mil; Holder, J. Darryl [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States); Corron, Ned J. [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States); Pethel, Shawn D. [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States)

    2005-10-10

    We present experimental observations of a microstrip circuit that produces Roessler-like chaos with center frequency of 175 MHz. A simply folded band chaotic attractor is created through a period doubling route. The circuit provides an experimental realization of a chaotic neutral delay differential equation, a largely unexplored type of nonlinear dynamical system.

  14. Absence of paired crossing in the positive parity bands of 124Cs

    Science.gov (United States)

    Singh, A. K.; Basu, A.; Nag, Somnath; Hübel, H.; Domscheit, J.; Ragnarsson, I.; Al-Khatib, A.; Hagemann, G. B.; Herskind, B.; Elema, D. R.; Wilson, J. N.; Clark, R. M.; Cromaz, M.; Fallon, P.; Görgen, A.; Lee, I.-Y.; Ward, D.; Ma, W. C.

    2018-02-01

    High-spin states in 124Cs were populated in the 64Ni(64Ni,p 3 n ) reaction and the Gammasphere detector array was used to measure γ -ray coincidences. Both positive- and negative-parity bands, including bands with chiral configurations, have been extended to higher spin, where a shape change has been observed. The configurations of the bands before and after the alignment are discussed within the framework of the cranked Nilsson-Strutinsky model. The calculations suggest that the nucleus undergoes a shape transition from triaxial to prolate around spin I ≃22 of the positive-parity states. The alignment gain of 8 ℏ , observed in the positive-parity bands, is due to partial alignment of several valence nucleons. This indicates the absence of band crossing due to paired nucleons in the bands.

  15. Linking an Artery to the Circulation : Introducing a Quasi-Simultaneous Coupling Approach for Partitioned Systems in Hemodynamics

    NARCIS (Netherlands)

    Rozema, G.; Maurits, N. M.; Veldman, A. E. P.; VanderSloten, J; Verdonck, P; Nyssen, M; Haueisen, J

    2009-01-01

    When modeling complex systems such as the cardiovascular circulation one often needs to separate the problem into smaller subproblems because of the heterogeneous nature of the system and/or the modeling techniques. The application at hand is to link blood flow in an artery to that in the

  16. The cyanogen band of Comet Halley

    Science.gov (United States)

    Tatum, J. B.; Campbell, E. C.

    The results of improved whole disk solar irradiance spectrum calculations performed for projected Halley's Comet heliocentric radial velocity and distance are provided. The computations were carried out to account for Doppler effects in the Fraunhofer lines of rotational excitation bands of violet CN emissions from the comet in its encounters with solar radiation. The calculations spanned every half-day for 200 days before and after perihelion. The 801 computer images of the expected intensities were photographed in sequence to form an animated film paced by background music from Liszt's Second Hungarian Rhapsody. The results are intended for accounting for spectral changes observed due to Doppler effects induced by changing velocity and distance, rather than physical mechanisms of the emitting processes.

  17. Photonic band gaps of porous solids

    International Nuclear Information System (INIS)

    Biswas, R.; Sigalas, M. M.; Subramania, G.; Soukoulis, C. M.; Ho, K.-M.

    2000-01-01

    Colloidal inverse photonic crystals composed of ordered lattices of air spheres in a high dielectric background are found to have three-dimensional photonic gaps for face-centered cubic, hexgaonal close-packed, and double hexagonal close-packed stacking sequences. Conditions for the occurrence of the complete gap are a sufficient dielectric contrast and a geometry near close packed. Although the lower pseudogaps of these stacking sequences differ, the lowest stop band in the stacking direction is insensitive to the stacking sequence; hence their experimental reflection should be similar. Transmission calculations with structural disorder show the lower pseudogap is relatively unaffected but the higher gap is very difficult to observe with moderate disorder. (c) 2000 The American Physical Society

  18. Thematic mapper studies band correlation analysis

    Science.gov (United States)

    Ungar, S. G.; Kiang, R.

    1976-01-01

    Spectral data representative of thematic mapper candidate bands 1 and 3 to 7 were obtained by selecting appropriate combinations of bands from the JSC 24 channel multispectral scanner. Of all the bands assigned, only candidate bands 4 (.74 mu to .80 mu) and 5 (.80 mu to .91 mu) showed consistently high intercorrelation from region to region and time to time. This extremely high correlation persisted when looking at the composite data set in a multitemporal, multilocation domain. The GISS investigations lend positive confirmation to the hypothesis, that TM bands 4 and 5 are redundant.

  19. Experimental Evaluation of Cold-Sprayed Copper Rotating Bands for Large-Caliber Projectiles

    Science.gov (United States)

    2015-05-01

    process parameters used during the initial deposition of copper material, given the observation that these initial copper rotating bands tended to “ flake ...ARL-TR-7299 ● MAY 2015 US Army Research Laboratory Experimental Evaluation of Cold-Sprayed Copper Rotating Bands for Large...Experimental Evaluation of Cold-Sprayed Copper Rotating Bands for Large-Caliber Projectiles by Michael A Minnicino Weapons and Materials Research

  20. Gamma decay and band structures in 46Ti

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Radford, D.C.; Poletti, A.R.

    1978-03-01

    The states of 46 Ti have been studied using the 43 Ca(α,nγ) reaction. The level and decay scheme of 46 Ti was deduced from γ-γ coincidence, γ-ray energy and intensity measurements. Spins are suggested on the basis of the γ-ray angular distribution, supported by relative excitation functions. The ground state band has been extended to spin 10 + , and about 20 new states are observed. Some of these can be grouped into rotational-like bands based on the 3 - state at 3.059 MeV and other excited states

  1. Mechanical Design of Military Communication Satellite X-band PCM

    Directory of Open Access Journals (Sweden)

    Hyung Je Woo

    1998-12-01

    Full Text Available Before an actual military communications satellite is designed and constructed, a feasibility study should take place. The basic functions of such system can be observed and demonstrated in an X-Band payload simulator. For this purpose a Payload Concept Model (PCM for X-Band payload subsystem has been developed to simulate the workings of an actual military communications payload. This paper explains and illustrates the mechanical design, manufacture, and integration of the PCM. Basic RF tests also have been performed in order to verify the design requirement of the system. The results demonstrate successful development of the PCM and operation without RF losses.

  2. Table of members of quasi-bands

    International Nuclear Information System (INIS)

    Sakai, Mitsuo.

    1984-04-01

    The probable members of the quasi-bands in even-even nuclei for Z between 6 and 100 are listed in this table. The terms quasi-bands have been introduced in the so-called spherical regions as the counter parts of the collective bands in the deformed regions. In the present compilation, the data for deformed nuclei are classified for convenience under the same titles, Quasi-Ground Band, Quasi-Beta Band and Quasi-Gamma Band, as are used for other nuclear regions. The present edition covers the literature through September, 1983. Fifteen newly discovered nuclides are included. The classification of energy level into quasi-bands is made on the basis of the systematic trend in the data over large groups of nuclei. (Kato, T.)

  3. A Novel Ku-Band/Ka-Band and Ka-Band/E-Band Multimode Waveguide Couplers for Power Measurement of Traveling-Wave Tube Amplifier Harmonic Frequencies

    Science.gov (United States)

    Wintucky, Edwin G.; Simons, Rainee N.

    2015-01-01

    This paper presents the design, fabrication and test results for a novel waveguide multimode directional coupler (MDC). The coupler, fabricated from two dissimilar frequency band waveguides, is capable of isolating power at the second harmonic frequency from the fundamental power at the output port of a traveling-wave tube (TWT) amplifier. Test results from proof-of-concept demonstrations are presented for a Ku-band/Ka-band MDC and a Ka-band/E-band MDC. In addition to power measurements at harmonic frequencies, a potential application of the MDC is in the design of a satellite borne beacon source for atmospheric propagation studies at millimeter-wave (mm-wave) frequencies (Ka-band and E-band).

  4. Dual-band frequency selective surface with large band separation and stable performance

    Science.gov (United States)

    Zhou, Hang; Qu, Shao-Bo; Peng, Wei-Dong; Lin, Bao-Qin; Wang, Jia-Fu; Ma, Hua; Zhang, Jie-Qiu; Bai, Peng; Wang, Xu-Hua; Xu, Zhuo

    2012-05-01

    A new technique of designing a dual-band frequency selective surface with large band separation is presented. This technique is based on a delicately designed topology of L- and Ku-band microwave filters. The two band-pass responses are generated by a capacitively-loaded square-loop frequency selective surface and an aperture-coupled frequency selective surface, respectively. A Faraday cage is located between the two frequency selective surface structures to eliminate undesired couplings. Based on this technique, a dual-band frequency selective surface with large band separation is designed, which possesses large band separation, high selectivity, and stable performance under various incident angles and different polarizations.

  5. Deformation bands in porous sandstones their microstructure and petrophysical properties

    Energy Technology Data Exchange (ETDEWEB)

    Torabi, Anita

    2007-12-15

    Deformation bands are commonly thin tabular zones of crushed or reorganized grains that form in highly porous rocks and sediments. Unlike a fault, typically the slip is negligible in deformation bands. In this dissertation the microstructure and petrophysical properties of deformation bands have been investigated through microscopy and numerical analysis of experimental and natural examples. The experimental work consists of a series of ring-shear experiments performed on porous sand at 5 and 20 MPa normal stresses and followed by microscopic examination of thin sections from the sheared samples. The results of the ring-shear experiments and comparison of them to natural deformation bands reveals that burial depth (level of normal stress in the experiments) and the amount of shear displacement during deformation are the two significant factors influencing the mode in which grains break and the type of shear zone that forms. Two end-member types of experimental shear zones were identified: (a) Shear zones with diffuse boundaries, which formed at low levels of normal stress and/or shear displacement; and (b) Shear zones with sharp boundaries, which formed at higher levels of normal stress and/or shear displacement. Our interpretation is that with increasing burial depth (approximately more than one kilometer, simulated in the experiments by higher levels of normal stress), the predominant mode of grain fracturing changes from flaking to splitting; which facilitates the formation of sharp-boundary shear zones. This change to grain splitting increases the power law dimension of the grain size distribution (D is about 1.5 in sharp boundary shear zones). Based on our observations, initial grain size has no influence in the deformation behavior of the sand at 5 MPa normal stresses. A new type of cataclastic deformation band is described through outcrop and microscopic studies; here termed a 'slipped deformation band'. Whereas previously reported cataclastic

  6. Migratory connectivity of american woodcock using band return data

    Science.gov (United States)

    Moore, Joseph D.; Krementz, David G.

    2017-01-01

    American woodcock (Scolopax minor) are managed as a Central and an Eastern population in the United States and Canada based on band return data showing little crossover between populations or management regions. The observed proportion of crossover between management regions, however, depends on the criteria used to subset the band return data. We analyzed the amount of crossover between management regions using only band return records that represent complete migrations between the breeding and wintering grounds by using only band return records in which the capture took place during the breeding season and the band recovery took place during the wintering season or vice versa (n = 224). Additionally, we applied spatial statistics and a clustering algorithm to investigate woodcock migratory connectivity using this subset of migratory woodcock band return records. Using raw counts, 17.9% of records showed crossover between management regions, a higher proportion than the <5% crossover reported in studies that did not use only migratory band returns. Our results showed woodcock from the breeding grounds in the Central Region largely migrate to destinations within the Central Region, whereas woodcock from the breeding grounds in the Eastern Region migrate to destinations across the entire wintering range and mix with individuals from the Central Region. Using the division coefficient, we estimated that 54% of woodcock from the breeding grounds of the Eastern Region migrate to the Central Region wintering grounds. Our result that many woodcock from separate regions of the breeding grounds mix on the wintering grounds has implications for the 2-region basis for woodcock management. Elucidating finer scale movement patterns among regions provides a basis for reassessing the need for separate management regions to ensure optimal conservation and management of the species.

  7. Table of superdeformed nuclear bands and fission isomers

    International Nuclear Information System (INIS)

    Firestone, R.B.; Singh, B.

    1994-06-01

    A minimum in the second potential well of deformed nuclei was predicted and the associated shell gaps are illustrated in the harmonic oscillator potential shell energy surface calculations shown in this report. A strong superdeformed minimum in 152 Dy was predicted for β 2 -0.65. Subsequently, a discrete set of γ-ray transitions in 152 DY was observed and, assigned to the predicted superdeformed band. Extensive research at several laboratories has since focused on searching for other mass regions of large deformation. A new generation of γ-ray detector arrays is already producing a wealth of information about the mechanisms for feeding and deexciting superdeformed bands. These bands have been found in three distinct regions near A=l30, 150, and 190. This research extends upon previous work in the actinide region near A=240 where fission isomers were identified and also associated with the second potential well. Quadrupole moment measurements for selected cases in each mass region are consistent with assigning the bands to excitations in the second local minimum. As part of our committment to maintain nuclear structure data as current as possible in the Evaluated Nuclear Structure Reference File (ENSDF) and the Table of Isotopes, we have updated the information on superdeformed nuclear bands. As of April 1994, we have complied data from 86 superdeformed bands and 46 fission isomers identified in 73 nuclides for this report. For each nuclide there is a complete level table listing both normal and superdeformed band assignments; level energy, spin, parity, half-life, magneto moments, decay branchings; and the energies, final levels, relative intensities, multipolarities, and mixing ratios for transitions deexciting each level. Mass excess, decay energies, and proton and neutron separation energies are also provided from the evaluation of Audi and Wapstra

  8. Table of superdeformed nuclear bands and fission isomers

    Energy Technology Data Exchange (ETDEWEB)

    Firestone, R.B. [Lawrence Berkeley Lab., CA (United States); Singh, B. [McMaster Univ., Hamilton, ON (Canada)

    1994-06-01

    A minimum in the second potential well of deformed nuclei was predicted and the associated shell gaps are illustrated in the harmonic oscillator potential shell energy surface calculations shown in this report. A strong superdeformed minimum in {sup 152}Dy was predicted for {beta}{sub 2}-0.65. Subsequently, a discrete set of {gamma}-ray transitions in {sup 152}DY was observed and, assigned to the predicted superdeformed band. Extensive research at several laboratories has since focused on searching for other mass regions of large deformation. A new generation of {gamma}-ray detector arrays is already producing a wealth of information about the mechanisms for feeding and deexciting superdeformed bands. These bands have been found in three distinct regions near A=l30, 150, and 190. This research extends upon previous work in the actinide region near A=240 where fission isomers were identified and also associated with the second potential well. Quadrupole moment measurements for selected cases in each mass region are consistent with assigning the bands to excitations in the second local minimum. As part of our committment to maintain nuclear structure data as current as possible in the Evaluated Nuclear Structure Reference File (ENSDF) and the Table of Isotopes, we have updated the information on superdeformed nuclear bands. As of April 1994, we have complied data from 86 superdeformed bands and 46 fission isomers identified in 73 nuclides for this report. For each nuclide there is a complete level table listing both normal and superdeformed band assignments; level energy, spin, parity, half-life, magneto moments, decay branchings; and the energies, final levels, relative intensities, multipolarities, and mixing ratios for transitions deexciting each level. Mass excess, decay energies, and proton and neutron separation energies are also provided from the evaluation of Audi and Wapstra.

  9. Search for superdeformed bands in {sup 154}Dy

    Energy Technology Data Exchange (ETDEWEB)

    Nisius, D.; Janssens, R.V.F.; Khoo, T.L. [and others

    1995-08-01

    The island of superdeformation in the vicinity of the doubly magic {sup 152}Dy yrast superdeformed (SD) band is thought to be well understood in the framework of cranked mean field calculations. In particular, the calculations suggested that in {sup 154}Dy there should be no yrast or near yrast SD minimum in the 40-60 h spin range, where SD bands in this mass region are thought to be {sup 153}Dy nucleus, it is populated. However, with the presence of five SD bands in the neighboring necessary to ascertain if the addition of one single neutron diminishes the importance of shell effects to the extent that superdeformation can no longer be sustained. In an experiment utilizing the increased resolving power of the early implementation phase of Gammasphere, the reaction {sup 122}Sn({sup 36}S,4n) at 165 MeV was employed to populate high spin states in {sup 154}Dy. In a four-day run with 36 detectors, over one billion triple and higher fold coincidence events were recorded. One new SD band was identified and was assigned to {sup 154}Dy. From comparisons with the Im{sup (2)} moments of inertia of the SD bands in {sup 152}Dy and {sup 153}Dy, a configuration based on (514)9/2{sup 2} neutrons coupled to the {sup 152}Dy SD core was proposed. One unexpected and as yet unexplained feature of this new SD band is that the transition energies are almost identical to those of an excited SD band in {sup 153}Dy. It is also worth noting that the feeding of the yrast states is similar to that achieved by the deexcitation from the ensemble of all entry states in the reaction. This observation emphasizes the statistical nature of the decay-out process. A paper reporting these results was accepted for publication.

  10. Band structure and Fermi surface of UPd2Al3 studied by angle-resolved photoemission spectroscopy

    International Nuclear Information System (INIS)

    Fujimori, Shin-ichi; Saitoh, Yuji; Okane, Tetsuo; Yamagami, Hiroshi; Fujimori, Atsushi; Haga, Yoshinori; Yamamoto, Etsuji; Onuki, Yoshichika

    2007-01-01

    We have observed the band structure and Fermi surfaces of the heavy Fermion superconductor UPd 2 Al 3 by angle-resolved photoemission experiments in the soft X-ray region. We observed renormalized quasi-particle bands in the vicinity of the Fermi level and strongly dispersive bands on the higher binding energy side. Our observation suggests that the structure previously assigned to contributions from localized states in the U 5f spectrum has strong energy dispersions

  11. Search for the characters of chiral rotation in excited bands for the idea chiral nuclei with A ∼ 130

    International Nuclear Information System (INIS)

    Chen Qibo; Yao Jiangming; Meng Jie; Zhang Shuangquan; Qi Bin

    2010-01-01

    Since the occurrence of chirality was originally suggested in 1997 by Frauendorf and Meng [1] and experimentally observed in 2001 [2] , the investigation of chiral symmetry in atomic nuclei becomes one of the most important topics in nuclear physics. More and more chiral doublet bands [3-7] in atomic nuclei [8] have been reported. There are also many discussions about the fingerprints of chirality. In the pioneer paper [1] , the two lowest near degenerate bands given by the particle-rotor model (PRM) are interpreted as chiral doublet bands. If the nucleus has chiral geometry with proper configuration, the character of chiral rotation may appear not only in the two lowest bands, but also in the other bands. Therefore, it is interesting to search for the character of chiral rotation, Based on the PRM model with configuration corresponding to A ∼ 130 mass region, we examine the theoretical spectroscopy of higher excited bands (band3, band4, band5 and band6) beyond the two lowest bands (bandl and band2), including energies, spin-alignments, projection of total angular momentum and electromagnetic transition probabilities. The results show that band3 and band4 have characters of chirality in some spin region. (authors)

  12. Decay out of the superdeformed band in {sup 143}Eu

    Energy Technology Data Exchange (ETDEWEB)

    Atac, A; Piiparinen, M; Herskind, B [Copenhagen Univ. (Denmark); and others

    1992-08-01

    The connection between the super-deformed (SD) and normal-deformed (ND) states had not been observed, owing its difficulty to a statistical, highly fragmented decay path out of the SD bands. This left both the spin and the excitation energy of the SD bands undetermined. In this paper, the authors present results of a new experimental approach, where they take advantage of triple and higher-fold coincidences to study the decay-out of a SD band. They carried out an experiment at the Niels Bohr Institute Tandem Accelerator Laboratory, where they used the (160 MeV) {sup 37}Cl + {sup 110}Pd {yields} {sup 143}Eu + 4n reaction. 9 refs., 3 figs.

  13. Search for excited superdeformed bands in {sup 151}Dy

    Energy Technology Data Exchange (ETDEWEB)

    Nisius, D.; Janssens, R.V.F.; Crowell, B. [and others

    1995-08-01

    Following the first report of superdeformed (SD) bands with identical transition energies in the pairs ({sup 151}Tb*,{sup 152}Dy), ({sup 150}Gd*, {sup 151}Tb) and ({sup 153}Dy*, {sup 152}Dy) (where * denotes an excited SD band), it was proposed by Nazarewicz et al. that the observations could be understood in a strong-coupling approach if pseudo SU(3) symmetry were invoked. In this model there are three limiting values of the decoupling parameter; i.e. a = 0, {plus_minus}1. In the first two cases mentioned above the pairs of bands have nearly identical transition energies and are interpreted as proton excitations involving the [200]1/2 pseudospin orbital coupled to the {sup 152}Dy core, for which the value of the decoupling parameter is calculated to be a =+1.

  14. New bands and spin-parity assignments in 111Ru

    International Nuclear Information System (INIS)

    Urban, W.; Rzaca-Urban, T.; Droste, C.; Rohozinski, S.G.; Durell, J.L.; Phillips, W.R.; Smith, A.G.; Varley, B.J.; Schulz, N.; Ahmad, I.; Pinston, J.A.

    2004-01-01

    The 111 Ru nucleus, populated in the spontaneous fission of 248 Cm has been studied by means of prompt gamma spectroscopy using the EUROGAM2 array. Spin and parity assignments, based on angular correlations, linear polarization, and conversion coefficient measurements differ from those available in the literature. New bands are reported, which incorporate γ transitions seen previously but not placed in the scheme of 111 Ru or placed incorrectly. The bands are interpreted as neutron excitations into subshells originating predominantly from the h 11/2 , g 7/2 and s 1/2 spherical orbitals. The s 1/2 band, strongly mixed with the d 3/2 , d 5/2 and g 7/2 configurations, is observed for the first time in this region. (orig.)

  15. Photonic band gap structure simulator

    Science.gov (United States)

    Chen, Chiping; Shapiro, Michael A.; Smirnova, Evgenya I.; Temkin, Richard J.; Sirigiri, Jagadishwar R.

    2006-10-03

    A system and method for designing photonic band gap structures. The system and method provide a user with the capability to produce a model of a two-dimensional array of conductors corresponding to a unit cell. The model involves a linear equation. Boundary conditions representative of conditions at the boundary of the unit cell are applied to a solution of the Helmholtz equation defined for the unit cell. The linear equation can be approximated by a Hermitian matrix. An eigenvalue of the Helmholtz equation is calculated. One computation approach involves calculating finite differences. The model can include a symmetry element, such as a center of inversion, a rotation axis, and a mirror plane. A graphical user interface is provided for the user's convenience. A display is provided to display to a user the calculated eigenvalue, corresponding to a photonic energy level in the Brilloin zone of the unit cell.

  16. Determination of shift in energy of band edges and band gap of ZnSe spherical quantum dot

    Science.gov (United States)

    Siboh, Dutem; Kalita, Pradip Kumar; Sarma, Jayanta Kumar; Nath, Nayan Mani

    2018-04-01

    We have determined the quantum confinement induced shifts in energy of band edges and band gap with respect to size of ZnSe spherical quantum dot employing an effective confinement potential model developed in our earlier communication "arXiv:1705.10343". We have also performed phenomenological analysis of our theoretical results in comparison with available experimental data and observe a very good agreement in this regard. Phenomenological success achieved in this regard confirms validity of the confining potential model as well as signifies the capability and applicability of the ansatz for the effective confining potential to have reasonable information in the study of real nano-structured spherical systems.

  17. Annual Growth Bands in Hymenaea courbaril

    Energy Technology Data Exchange (ETDEWEB)

    Westbrook, J A; Guilderson, T P; Colinvaux, P A

    2004-02-09

    One significant source of annual temperature and precipitation data arises from the regular annual secondary growth rings of trees. Several tropical tree species are observed to form regular growth bands that may or may not form annually. Such growth was observed in one stem disk of the tropical legume Hymenaea courbaril near the area of David, Panama. In comparison to annual reference {Delta}{sup 14}C values from wood and air, the {Delta}{sup 14}C values from the secondary growth rings formed by H. courbaril were determined to be annual in nature in this one stem disk specimen. During this study, H. courbaril was also observed to translocate recently produced photosynthate into older growth rings as sapwood is converted to heartwood. This process alters the overall {Delta}{sup 14}C values of these transitional growth rings as cellulose with a higher {Delta}{sup 14}C content is translocated into growth rings with a relatively lower {Delta}{sup 14}C content. Once the annual nature of these growth rings is established, further stable isotope analyses on H. courbaril material in other studies may help to complete gaps in the understanding of short and of long term global climate patterns.

  18. Broad-band beam buncher

    International Nuclear Information System (INIS)

    Goldberg, D.A.; Flood, W.S.; Arthur, A.A.; Voelker, F.

    1986-01-01

    This patent describes a broad-band beam buncher. This beam buncher consists of: a housing adapted to be eacuated, an electron gun in the housing for producing a beam of electrons, buncher means in the housing forming a buncher cavity which has an entrance opening for receiving the electron beam and an exit opening through which the electron beam passes out of the buncher cavity, a drift tube electrode in the buncher cavity and disposed between the entrance opening and the exit opening with first and second gaps between the drift tube electrode and the entrance and exit openings, the drift tube electrode which has a first drift space through which the electron beam passes in traveling between the entrance and exit openings, modulating means for supplying an ultrahigh frequeny modulating signal to the drift tube electrode for producing velocity modulation of the electrons in the electron beam as the electrons pass through the buncher cavity and the drift tube electrode between the entrance opening and the exit opening, drift space means in the housing forming a second drift space for receiving the velocity modulated electron beam from the exit opening, the velocity modulated electron beam being bunched as it passes along the second drift space, the drift space means has a discharge opening through which the electron beam is discharged from the second drift space after being bunched therein, the modulating means containing a signal source for producing an ultrahigh frequency signal, a transmission line connected between the signal source and the drift tube electrode, and terminating means connected to the drift tube electrode for terminating the transmission line in approximately its characteristic impedance to afford a broad response band with minimum 6 variations therein

  19. Single and multi-band electromagnetic induced transparency-like metamaterials with coupled split ring resonators

    Science.gov (United States)

    Bagci, Fulya; Akaoglu, Baris

    2017-08-01

    We present a metamaterial configuration exhibiting single and multi-band electromagnetic induced transparency (EIT)-like properties. The unit cell of the single band EIT-like metamaterial consists of a multi-split ring resonator surrounded by a split ring resonator. The multi-split ring resonator acts as a quasi-dark or dark resonator, depending on the polarization of the incident wave, and the split ring resonator serves as the bright resonator. Combination of these two resonators results in a single band EIT-like transmission inside the stop band. EIT-like transmission phenomenon is also clearly observed in the measured transmission spectrum at almost the same frequencies for vertical and horizontal polarized waves, and the numerical results are verified for normal incidence. Moreover, multi-band transmission windows are created within a wide band by combining the two slightly different single band EIT-like metamaterial unit cells that exhibit two different coupling strengths inside a supercell configuration. Group indices as high as 123 for single band and 488 for tri-band transmission, accompanying with high transmission rates (over 80%), are achieved, rendering the metamaterial very suitable for multi-band slow light applications. It is shown that the group delay of the propagating wave can be increased and dynamically controlled by changing the polarization angle. Multi-band EIT-like transmission is also verified experimentally, and a good agreement with simulations is obtained. The proposed novel methodology for obtaining multi-band EIT, which takes advantage of a supercell configuration by hosting slightly different configured unit cells, can be utilized for easily formation and manipulation of multi-band transmission windows inside a stop band.

  20. Backbendings of superdeformed bands in 36;40Ar

    Science.gov (United States)

    Xiang, Xu-Hui; He, Xiao-Tao

    2018-05-01

    Experimentally observed superdeformed (SD) rotational bands in 36Ar and 40Ar are studied by the cranked shell model (CSM) with the pairing correlations treated by a particle-number-conserving (PNC) method. This is the first time that PNC-CSM calculations have been performed on the light nuclear mass region around A=40. The experimental kinematic moments of inertia J (1) versus rotational frequency are reproduced well. The backbending of the SD band at frequency around ℏω=1.5 MeV in 36Ar is attributed to the sharp rise of the simultaneous alignments of the neutron and proton 1d 5/2[202]5/2 pairs and 1f 7/2[321]3/2 pairs, which is a consequence of the band crossing between the 1d 5/2[202]5/2 and 1f 7/2[321]3/2 configuration states. The gentle upbending at low frequency of the SD band in 40Ar is mainly affected by the alignments of the neutron 1f 7/2[321]3/2 pairs and proton 1d 5/2[202]5/2 pairs. The PNC-CSM calculations show that besides the diagonal parts, the off-diagonal parts of the alignments play an important role in the rotational behavior of the SD bands. Supported by National Natural Science Foundation of China (11775112 and 11275098) and the Priority Academic Program Development of Jiangsu Higher Education Institutions

  1. Diffusion properties of band 3 in human erythrocytes

    Science.gov (United States)

    Spector, Jeffrey O.

    The plasma membrane of the human erythrocyte (RBC) is a six fold symmetric network held together at various pinning points by several multi-protein complexes. This unique architecture is what gives the RBC its remarkable material properties and any disruptions to the network can have severe consequences for the cell. Band 3 is a major transmembrane protein that plays the role of linking the fluid lipid bilayer to the cytoskeletal network. To interrogate the structural integrity of the RBC membrane we have tracked individual band 3 molecules in RBCs displaying a variety of pathologies that are all a consequence of membrane or network related defects. These diseases are spherocytosis, elliptocytosis, and pyropokilocytosis. We have also investigated the protein related diseases sickle cell, and south east asian ovalocytosis. To assess the impact that the network has on the dynamic organization of the cell we have also studied the mobility of band 3 in RBC progenitor cells. Individual band 3 molecules were imaged at 120 frames/second and their diffusion coefficients and compartment sizes recorded. The distributions of the compartment sizes combined with the information about the short and long time diffusion of band 3 has given us insight into the architecture of the membrane in normal and diseased cells. The observation that different membrane pathologies can be distinguished, even to the point of different molecular origins of the same disease, implies that the mobility of transmembrane proteins may be a useful tool for characterizing the "health" of the membrane.

  2. Traction calculation of band conveyors using the ''Nairi-2'' computer

    Energy Technology Data Exchange (ETDEWEB)

    Kutlunin, V A; Livshis, A V; Pod' yemshchikov, A N

    1982-01-01

    An algorithm is described and a program is introduced for traction calculation of band conveyors using the ''Nairi-2'' computer. The calculation system of the conveyor is derived by means of dividing the closed loop of the band into straight sections, which are separated by drums. The number of sections depends on the number of drums, the bypass system of them by the band, the shape of the conveyor route and in each specific case, a specific number is chosen. The initial information for the computer is assigned by a matrix, each row of which consists of parameters of the corresponding section. As a result, the forces of the beginning and end of the sections are found, and the required output of the drive motors with observance of the conditions of non-slippage of the drive drums and limiting of the maximum slack of the band between rollers are also found. The program allows one to make traction calculations of band conveyors with any routing shape for any number and position of the drive drums.

  3. Band 3 in aging and neurological disease.

    Science.gov (United States)

    Kay, M M

    1991-01-01

    Senescent cell antigen appears on old cells and marks them for death by initiating the binding of IgG autoantibody and subsequent removal by phagocytes in mammals and other vertebrates. We have created a synthetic aging antigen that blocks binding of IgG to senescent cells in vitro. Synthetic senescent cell antigen might be effective in preventing cellular destruction in vivo in certain diseases, and can be used to manipulate cellular life span in situ. Senescent cell antigen is generated by the modification of an important structural and transport membrane molecule, protein band 3. Band 3 is present in cellular, nuclear, Golgi, and mitochondrial membranes as well as in cell membranes. Band 3 proteins in nucleated cells participate in cell surface patching and capping. Band 3 maintains acid-base balance by mediating the exchange of anions (e.g., chloride, bicarbonate), and is the binding site for glycolytic enzymes. It is responsible for CO2 exchange in all tissues and organs. Thus, it is the most heavily used anion transport system in the body. Band 3 is a major transmembrane structural protein which attaches the plasma membrane to the internal cell cytoskeleton by binding to band 2.1 (ankyrin). Oxidation generates senescent cell antigen in situ. Band 3 is present in the central nervous system, and differences have been described in band 3 between young and aging brain tissue. One autosomal recessive neurological disease, choreoacanthocytosis, is associated with band 3 abnormalities. The 150 residues of the carboxyl terminus segment of band 3 appear to be altered. In brains from Alzheimer's disease patients, antibodies to aged band 3 label the amyloid core of classical plaques and the microglial cells located in the middle of the plaque in tissue sections, and an abnormal band 3 in immunoblots. Band 3 protein(s) in mammalian brain performs the same functions as that of erythroid band 3. These functions is anion transport, ankyrin binding, and generation of

  4. The dynamics of a shear band

    Science.gov (United States)

    Giarola, Diana; Capuani, Domenico; Bigoni, Davide

    2018-03-01

    A shear band of finite length, formed inside a ductile material at a certain stage of a continued homogeneous strain, provides a dynamic perturbation to an incident wave field, which strongly influences the dynamics of the material and affects its path to failure. The investigation of this perturbation is presented for a ductile metal, with reference to the incremental mechanics of a material obeying the J2-deformation theory of plasticity (a special form of prestressed, elastic, anisotropic, and incompressible solid). The treatment originates from the derivation of integral representations relating the incremental mechanical fields at every point of the medium to the incremental displacement jump across the shear band faces, generated by an impinging wave. The boundary integral equations (under the plane strain assumption) are numerically approached through a collocation technique, which keeps into account the singularity at the shear band tips and permits the analysis of an incident wave impinging a shear band. It is shown that the presence of the shear band induces a resonance, visible in the incremental displacement field and in the stress intensity factor at the shear band tips, which promotes shear band growth. Moreover, the waves scattered by the shear band are shown to generate a fine texture of vibrations, parallel to the shear band line and propagating at a long distance from it, but leaving a sort of conical shadow zone, which emanates from the tips of the shear band.

  5. Multiparticle excitations and identical bands in the superdeformed 149Gd nucleus

    International Nuclear Information System (INIS)

    Flibotte, S.; Hackman, G.; Theisen, C.; Andrews, H.R.; Ball, G.C.; Beausang, C.W.; Beck, F.A.; Belier, G.; Bentley, M.A.; Byrski, T.; Curien, D.; de France, G.; Disdier, D.; Duchene, G.; Fallon, P.; Haas, B.; Janzen, V.P.; Jones, P.M.; Kharraja, B.; Kuehner, J.A.; Lisle, J.C.; Merdinger, J.C.; Mullins, S.M.; Paul, E.S.; Prevost, D.; Radford, D.C.; Rauch, V.; Smith, J.F.; Styczen, J.; Twin, P.J.; Vivien, J.P.; Waddington, J.C.; Ward, D.; Zuber, K.

    1993-01-01

    Eight superdeformed rotational bands have been observed in the 149 Gd nucleus. Several excited bands have partners in neighboring nuclei which differ by up to four nucleons, with nearly identical dynamic moments of inertia and quantized γ-ray phasing. These observations cannot be easily explained by theoretical models including an intrinsic scaling with mass of the moment of inertia. A paired backbend and an interaction due to an accidental degeneracy between two superdeformed levels have also been observed

  6. Tunable band gap emission and surface passivation of germanium nanocrystals synthesized in the gas phase

    NARCIS (Netherlands)

    Wheeler, LM; Levij, L.M.; Kortshagen, U.R.

    2013-01-01

    The narrow bulk band gap and large exciton Bohr radius of germanium (Ge) make it an attractive material for optoelectronics utilizing band-gap-tunable photoluminescence (PL). However, realization of PL due to quantum confinement remains scarcely reported. Instead, PL is often observed from surface

  7. Studies on the red absorption band of chlorophyll a in vivo

    NARCIS (Netherlands)

    Thomas, J.B.; Kleinen Hammans, J.W.; Arnolds, W.J.

    1965-01-01

    It was studied whether certain earlier observed weak shoulders on the red absorption band of chlorophyll a in vivo might represent anomalies due to overlap of absorption bands. The results are suggested of the fact that no such anomalies occur. It is therefore concluded that the present study

  8. The intensity of the 1602 cm-1 band in human cells is related to mitochondrial activity

    NARCIS (Netherlands)

    Pully, V.V.; Otto, Cornelis

    2009-01-01

    We report a Raman band at 1602 cm−1 in the spectra of human cells, which previously had only been observed in mitochondria of yeast cells. This band, which has not yet been assigned to a particular molecular species, was found to occur in HeLa cells, peripheral blood lymphocytes, human mesenchymal

  9. Kink bands in thrust regime: Examples from Srinagar–Garhwal area ...

    Indian Academy of Sciences (India)

    Srinagar–Garhwal; kink bands; paleostress; shearing along kink planes; Himalaya; North Almora Thrust. J. Earth Syst. Sci. 120, No. 5, October 2011, pp. 939–948 ..... The α>β geometry observed in kink bands suggest towards shearing as a common phenomenon along the kink planes. (Anderson 1964). Since considerable ...

  10. Theoretical study of relative width of photonic band gap for the 3-D ...

    Indian Academy of Sciences (India)

    ... of refractive index and relative radius of the photonic band gap for the fcc closed packed 3-D dielectric microstructure are reported and comparison of experimental observations and theoretical predictions are given. This work is useful for the understanding of photonic crystals and occurrence of the photonic band gap.

  11. Detailed characterization of complex banding in air-cooled bainitic steels

    Directory of Open Access Journals (Sweden)

    Morales-Rivas L.

    2015-01-01

    Full Text Available The presence of banding in a hot-rolled air-cooled bainitic steel has been thoroughly characterized. The banded microstructure was observed due to distinctive sensitivities to the etching agent. Microstructural and crystallographic studies by means of Scanning Electron Microscopy and Electron Backscatter Diffraction did not reveal any substantial differences between bands and matrix. However, solute segregation of some alloying elements was detected by Wavelength- Dispersive Spectroscopy, being found that bands are enriched in Cr, Mo and Si and depleted in Mn. Finally, a set of theoretical calculations suggested that the solidification mode is responsible for such unusual partitioning behavior, which is beneficial in terms of the bainitic transformation.

  12. Superdeformed bands of odd nuclei in A=190 region in the quasiparticle picture

    International Nuclear Information System (INIS)

    Terasaki, J.; Flocard, H.; Heenen, P.H.; Bonche, P.

    1996-07-01

    Properties of the superdeformed (SD) bands of 195 Pb and 193 Hg have been studied by the cranked Hartree-Fock-Bogoliubov method. The calculations reproduce the flat behavior of the dynamical moment of inertia of two of the SD bands of 195 Pb measured recently. Possible configuration assignments for the observed bands 3 and 4 of 195 Pb are discussed. The two interacting SD bands of 193 Hg have also been calculated. The analysis confirms the superiority of a density-dependent pairing force over a seniority pairing interaction. (author)

  13. Study of band terminating in the A ≅ 100 by EUROGAM

    International Nuclear Information System (INIS)

    Gizon, J.; Gizon, A.; Genevey, J.; Santos, D.; Nyako, B.M.; Timar, J.; Zolnai, L.; Boston, A.J.; Zoss, D.T.; Paul, E.S.; Semple, A.T.; O'Brien, N.J.; Parry, C.M.; Cata-Danil, Gh.; Bucurescu, D.; Afanasjev, A.V.; Ragnarsson, I.

    1997-01-01

    Terminating bands in nuclei in the A≅ 100 region have been investigated using the EUROGAM2 array. Results have been obtained for Pd (Z 46) and Rh (Z = 45) isotopes. In the nucleus 102 Pd, eight terminating configurations are identified. It is the first nucleus where terminating bands built on the valence space configurations and on core excited configurations are observed. Terminating bands have been also found in 103 Pd and 102 Rh. For 102 Rh it is the first case of band terminations identified in a doubly-odd nucleus below the Z = 50 shell closure. (authors)

  14. Outcome of band ligation in oesophageal varices

    International Nuclear Information System (INIS)

    Abbasi, A.; Bhutto, A.R.; Bhatti, K.I.; Mahmood, K.; Lal, K.

    2013-01-01

    Objective: To find out the outcome og band ligation of oesophageal varices in decompensated chronic liver disease patients. Methods: The quasi experimental study was conducted at the Jinnah Postgraduate Medical Centre, Karachi, and Civil Hospital, Karachi, unit from September 2007 to August 2011. Subjects were eligible if they had a diagnosis of cirrhosis based on history, physical examination, biochemical parameters and liver biopsy in some cases. Patients with advanced cirrhosis (Child-Pugh class C), antibodies against human immunodeficiency virus, hepatocellular carcinoma, portal vein thrombosis evident on ultrasonography, parenteral drug addiction, current alcohol abuse, previous or current treatment with β-blockers were excluded from the study. All patients were asked about alcohol intake and tested to determine the cause of liver cirrhosis. Tests for other causes of cirrhosis were carried out only if there was a suggestive clue. All patients under-went upper gastrointestinal endoscopy after consent. SPSS 15 was used for statistical analysis. Results: The age of the 173 patients who met the inclusion criteria ranged from 15 to 85 years, with a mean of 48.39+-13.38 years. There were 112 (64.7%) males. High-grade varices were seen in 130 (75.1%) patients, while low-grade varices were observed in 43 (24.9%) on first endoscopy. At initial endoscopy, 111 (64.2%) patients had portal hypertensive gastropathy. The patients were followed up for a mean period of 5.20+-2.67 months. Variceal obliteration was achieved in 138 (79.8%), while 33 (19.1%) cases developed re-bleeding. Mean number of endoscopy sessions for these patients were 2.28+-.918 with a maximum of 4. Conclusion: Band ligation eradicated oesophageal varices with less complications and a lower re-bleeding rate, but at the same time eradication was associated with more frequent development of portal hypertensive gastropathy. (author)

  15. Low-bias flat band-stop filter based on velocity modulated gaussian graphene superlattice

    Science.gov (United States)

    Sattari-Esfahlan, S. M.; Shojaei, S.

    2018-05-01

    Transport properties of biased planar Gaussian graphene superlattice (PGGSL) with Fermi velocity barrier is investigated by transfer matrix method (TMM). It is observed that enlargement of bias voltage over miniband width breaks the miniband to WSLs leads to suppressing resonant tunneling. Transmission spectrum shows flat wide stop-band property controllable by external bias voltage with stop-band width of near 200 meV. The simulations demonstrate that strong velocity barriers prevent tunneling of Dirac electrons leading to controllable enhancement of stop-band width. By increasing ratio of Fermi velocity in barriers to wells υc stop-band width increase. As wide transmission stop-band width (BWT) of filter is tunable from 40 meV to 340 meV is obtained by enhancing ratio of υc from 0.2 to 1.5, respectively. Proposed structure suggests easy tunable wide band-stop electronic filter with a modulated flat stop-band characteristic by height of electrostatic barrier and structural parameters. Robust sensitivity of band width to velocity barrier intensity in certain bias voltages and flat band feature of proposed filter may be opens novel venue in GSL based flat band low noise filters and velocity modulation devices.

  16. Multiple superdeformed bands in sup 194 Hg and their dynamical moments of inertia

    Energy Technology Data Exchange (ETDEWEB)

    Riley, M.A.; Cullen, D.M.; Alderson, A.; Ali, I.; Fallon, P.; Forsyth, P.D.; Hanna, F.; Mullins, S.M.; Roberts, J.W.; Sharpey-Schafer, J.F.; Twin, P.J. (Liverpool Univ. (UK). Oliver Lodge Lab.); Poynter, R.; Wadsworth, R. (York Univ. (UK). Dept. of Physics); Bentley, M.A.; Bruce, A.M.; Simpson, J. (Science and Engineering Research Council, Daresbury (UK). Daresbury Lab.); Sletten, G. (Niels Bohr Inst., Roskilde (Denmark). Tandem Accelerator Lab.); Nazarewicz, W. (Liverpool Univ. (UK). Oliver Lodge Lab. Politechnika Warszawska (Poland). Inst. Fizyki); Bengtsson, T. (Lund Inst. of Tech. (Sweden). Dept. of Mathematical Physics); Wyss, R. (Manne Siegbahn Inst. of Physics, Stockholm (Sweden))

    1990-05-28

    Three superdeformed bands have been observed in {sup 194}Hg. The dynamical moment of inertia J{sup (2)} of all three bands is observed to increase by 30-40% over the frequency range {Dirac h}{omega}=0.1-0.4 MeV. This phenomena can be understood in terms of the gradual alignment of pairs of high-j intruder orbitals within the framework of the cranked Woods-Saxon and Nilsson models including pairing. The calculations together with the observed J{sup (2)} behaviour of the three bands indicate that pairing correlations in the superdeformed minimum are rather weak. (orig.).

  17. Band resolution of optical spectra of solvated electrons in water, alcohols, and tetrahydrofuran

    International Nuclear Information System (INIS)

    Jou, F.-Y.; Freeman, G.R.

    1979-01-01

    The optical absorption spectra of solvated electrons in water, alcohols, and tetrahydrofuran are empirically resolved into two Gaussian bands and a continuum tail. The first Gaussian band covers most of the low energy side of the spectrum. The second Gaussian band lies at an energy slightly above that of the absorption maximum of the total spectrum. With the exception of tert-butyl alcohol, in water and alcohols the following were observed: (a) the first Gaussian bands have the same half-width, but the oscillator strength in water is about double that in an alcohol; (b) the second Gaussian bands have similar half-widths and oscillator strengths; (c) the continuum tails have similar half-widths, yet that in water possesses only about one third as much oscillator strength as the one in alcohol. In tert-butyl alcohol and tetrahydrofuran the first Gaussian band and the continuum tail each carry nearly half of the total oscillator strength. (author)

  18. Angular dependent XPS study of surface band bending on Ga-polar n-GaN

    Science.gov (United States)

    Huang, Rong; Liu, Tong; Zhao, Yanfei; Zhu, Yafeng; Huang, Zengli; Li, Fangsen; Liu, Jianping; Zhang, Liqun; Zhang, Shuming; Dingsun, An; Yang, Hui

    2018-05-01

    Surface band bending and composition of Ga-polar n-GaN with different surface treatments were characterized by using angular dependent X-ray photoelectron spectroscopy. Upward surface band bending of varying degree was observed distinctly upon to the treatment methods. Besides the nitrogen vacancies, we found that surface states of oxygen-containing absorbates (O-H component) also contribute to the surface band bending, which lead the Fermi level pined at a level further closer to the conduction band edge on n-GaN surface. The n-GaN surface with lower surface band bending exhibits better linear electrical properties for Ti/GaN Ohmic contacts. Moreover, the density of positively charged surface states could be derived from the values of surface band bending.

  19. Amniotic band syndrome: A clinical brief

    Directory of Open Access Journals (Sweden)

    Dasaradha Ramireddy Malireddy

    2017-01-01

    Full Text Available Amniotic band syndrome (ABS results from bands of amnion entangling fetal parts. They may manifest as constriction rings or complex congenital anomalies resulting in stillbirth. Karyotyping is important for exclusion of inherited disorders and proper counseling. Two case reports one stillbirth and the other with constriction ring of fingers and mild hydronephrosis are presented. The aim of this paper is to make awareness and stress the need for doing thorough work-up in all cases of constriction bands.

  20. Fade Mitigation Techniques at Ka-Band

    Science.gov (United States)

    Dissanayake, Asoka (Editor)

    1996-01-01

    Rain fading is the dominant propagation impairment affecting Ka-band satellite links and rain fade mitigation is a key element in the design of Ka-band satellite networks. Some of the common fade mitigation techniques include: power control, diversity, adaptive coding, and resource sharing. The Advanced Communications Technology Satellite (ACTS) provides an excellent opportunity to develop and test Ka-band rain impairment amelioration techniques. Up-link power control and diversity are discussed in this paper.

  1. BAND STRUCTURE OF NON-STEIOCHIOMETRIC LARGE-SIZED NANOCRYSTALLITES

    Directory of Open Access Journals (Sweden)

    I.V.Kityk

    2004-01-01

    Full Text Available A band structure of large-sized (from 20 to 35nm non-steichiometric nanocrystallites (NC of the Si2-xCx (1.04 < x < 1.10 has been investigated using different band energy approaches and a modified Car-Parinello molecular dynamics structure optimization of the NC interfaces. The non-steichiometric excess of carbon favors the appearance of a thin prevailingly carbon-contained layer (with thickness of about 1 nm covering the crystallites. As a consequence, one can observe a substantial structure reconstruction of boundary SiC crystalline layers. The numerical modeling has shown that these NC can be considered as SiC reconstructed crystalline films with thickness of about 2 nm covering the SiC crystallites. The observed data are considered within the different one-electron band structure methods. It was shown that the nano-sized carbon sheet plays a key role in a modified band structure. Independent manifestation of the important role played by the reconstructed confined layers is due to the experimentally discovered excitonic-like resonances. Low-temperature absorption measurements confirm the existence of sharp-like absorption resonances originating from the reconstructed layers.

  2. Predicting superdeformed rotational band-head spin in A ∼ 190 mass region using variable moment of inertia model

    International Nuclear Information System (INIS)

    Uma, V.S.; Goel, Alpana; Yadav, Archana; Jain, A.K.

    2016-01-01

    The band-head spin (I 0 ) of superdeformed (SD) rotational bands in A ∼ 190 mass region is predicted using the variable moment of inertia (VMI) model for 66 SD rotational bands. The superdeformed rotational bands exhibited considerably good rotational property and rigid behaviour. The transition energies were dependent on the prescribed band-head spins. The ratio of transition energies over spin Eγ/ 2 I (RTEOS) vs. angular momentum (I) have confirmed the rigid behaviour, provided the band-head spin value is assigned correctly. There is a good agreement between the calculated and the observed transition energies. This method gives a very comprehensive interpretation for spin assignment of SD rotational bands which could help in designing future experiments for SD bands. (author)

  3. Polarimetric and Structural Properties of a Boreal Forest at P-Band and L-Band

    Science.gov (United States)

    Tebaldini, S.; Rocca, F.

    2010-12-01

    allows to overcome this limitation, thus providing a way to obtain the vertical structures associated with volume-only contributions. Experimental results will be provided showing the following. At P-Band the most relevant scattering contributions are observed at the ground level, not only in the co-polar channels, but also in HV, consistently with he first BioSAR campaign. L-Band data have shown a remarkable difference, resulting in a more uniform distribution of the backscattered power along the vertical direction. Volume top height has been observed to be substantially invariant to the choice of the solution for volume-only scattering. These results underline the validity of modeling a forest scenario as being constituted by volume and ground (or rather ground-locked) scattering, and the importance of forest top height as the most robust indicator of the forest structure as imaged through microwaves measurements. Nevertheless, it has also been shown that different solutions for volume scattering correspond to dramatically different vertical structures. In this framework, tomography represents a powerful tool for investigating the potential solutions, as it allows to see what kind of vertical structure has been retrieved. On this basis, a solution has been proposed as a criterion to emphasize volume contributions at P-Band.

  4. Computational Design of Flat-Band Material

    Science.gov (United States)

    Hase, I.; Yanagisawa, T.; Kawashima, K.

    2018-02-01

    Quantum mechanics states that hopping integral between local orbitals makes the energy band dispersive. However, in some special cases, there are bands with no dispersion due to quantum interference. These bands are called as flat band. Many models having flat band have been proposed, and many interesting physical properties are predicted. However, no real compound having flat band has been found yet despite the 25 years of vigorous researches. We have found that some pyrochlore oxides have quasi-flat band just below the Fermi level by first principles calculation. Moreover, their valence bands are well described by a tight-binding model of pyrochlore lattice with isotropic nearest neighbor hopping integral. This model belongs to a class of Mielke model, whose ground state is known to be ferromagnetic with appropriate carrier doping and on-site repulsive Coulomb interaction. We have also performed a spin-polarized band calculation for the hole-doped system from first principles and found that the ground state is ferromagnetic for some doping region. Interestingly, these compounds do not include magnetic element, such as transition metal and rare-earth elements.

  5. Reward banding to determine reporting rate of recovered mourning dove bands

    Science.gov (United States)

    Tomlinson, R.E.

    1968-01-01

    Reward bands placed on the other leg of certain regularly banded immature mourning doves (Zenaidura macroura) were used to develop information on reporting rates of recovered dove bands. Reports from 15 widely separated sections of the United States showed considerable variation in recovery rate of doves both with and without reward bands. The overall percentages of banded doves that were reported as recovered were 9.69% for those with reward bands and 3.83% for controls. The bandreporting rate for states influenced by publicity was 66%; that for states not influenced was 32%.

  6. Rotational band structure in 132La

    International Nuclear Information System (INIS)

    Oliveira, J.R.B.; Emediato, L.G.R.; Rizzutto, M.A.; Ribas, R.V.; Seale, W.A.; Rao, M.N.; Medina, N.H.; Botelho, S.; Cybulska, E.W.

    1989-01-01

    '3'2La was studied using on-line gamma-spectroscopy through the reactions '1 24,126 Te( 11,10 B, 3, 4n) 132 La. The excitation function was obtained with 10 B(E lab =41.4; 45.4 and 48 MeV) in order to identify 132 La gamma-transitions. Gamma-gamma coincidences and angular distributions were performed for the 126 Te( 10 B, 4n) 132 La reaction. From the experimental results a rotational band with strongest M1 transitions and less intense 'cross-overs' E2 transitions was constructed. Using the methods of Bengtsson and Frauendorf the alignment (ix) and the Routhian (e') as a function of the angular velocity (ω) were also obtained from the experimental data. It was observed a constant alignment up to ω≅0.4 MeV, and a signature-splitting Δe'=25keV. Preliminary triaxial Cranking-Shell Model calculations indicate that a γ=-8deg deformation is consistent with the signature-splitting value of 25 keV experimentally observed. (Author) [es

  7. The infrared emission bands. III. Southern IRAS sources.

    Science.gov (United States)

    Cohen, M; Tielens, A G; Bregman, J; Witteborn, F C; Rank, D M; Allamandola, L J; Wooden, D H; de Muizon, M

    1989-06-01

    We present airborne 5-8 micrometers spectra of southern IRAS sources which reveal strong polycyclic aromatic hydrocarbon (PAH) emission features. The good correlation between the bands, in particular the dominant 6.2 and "7.7" micrometers features, strongly imply a common carrier, reinforcing the PAH hypothesis. However, small but detectable spectral variations exist. Planetaries have a distinctly different ratio of I(6.2)/I(7.7) than other nebulae, accompanied by a redward shift in the actual wavelength of the "7.7" micrometers peak. Further, we have detected a new feature, previously predicted from laboratory spectra of PAH molecules, at 5.2 micrometers in many of these sources. Spectra of two rare [WC 10] planetary nebular nuclei indicate a very prominent plateau of emission, linking the 6.2 and 7.7 micrometers bands. Several of our sources show definite evidence for emission structure between 14 and 23 micrometers in their IRAS Low-Resolution Spectral Atlas spectra: we attribute this structure to PAH bands. too. We have defined the "generic" spectrum of emission bands relating the mean intensities of each band to that of the strongest, near 7.7 micrometers. We have added three more planetary or protoplanetary nebulae to our correlation between 7.7 micrometers band intensity and nebular gas phase C/O ratio, namely NGC 6302, HR 4049, and the highly carbon-rich [WC 10] nucleus, CPD--56 degrees 8032. For the latter we have determined a ratio for C/O of approximately 4.8 from IUE observations. The good correlation between the intensity ratio of the "7.7" micrometers feature relative to the far-infrared dust continuum and nebular C/O also supports a carbonaceous carrier for these emission features.

  8. The broad-band overlap problem in atmospheric trace gases

    International Nuclear Information System (INIS)

    Subasilar, B.

    1991-01-01

    In relation to a better understanding of climate change and the related greenhouse problem, one way of projecting for the next decades is through general circulation models (GCMs). The only input as a driving force in the changing atmospheric and oceanic circulation patterns is the amount of heat perturbation either due to natural or man-caused activities. Among these, CO 2 concentrations resulting from the latter has been observed to be accelerating at alarmingly high rates especially after the advent of the industrialization which just began in the last century. In addition to that, collective effects of other greenhouse gases (freons, SO 2 , H 2 O, CH 4 , etc.) are as important as CO 2 . Hence, it is evident from the above considerations that, in the predictions of climate models, the heat input which triggers changes in the atmospheric patterns, should be formulated accurately. In order to realize this objective, in this research, beginning with the available line parameter data, the problems of absorption have been investigated and attacked in the frame known as the broad band modeling since that is the only best and fastest manageable representation for GCMs. The first step was the construction of a full broad band (intra band overlap) model that was also flexible enough to accommodate the individual peculiarities of the bands. Before, the well known and very useful Ramanathan model had a limited applicability in the concentration scale, and it was also not systematically or successfully incorporated into an inter band overlap picture. Then, the established ideas that served as bases up to present, have been employed but found to have a limited practical applicability when it came to predict the inter band overlaps

  9. Spins of superdeformed band in {sup 192}Hg

    Energy Technology Data Exchange (ETDEWEB)

    Lauritsen, T.; Khoo, T.L.; Henry, R.G. [and others

    1995-08-01

    Determination of the spins of SD states is the most important challenge in the study of superdeformation. Knowledge of the spin will provide crucial information on SD bands, in particular on the fascinating phenomenon of bands with identical energies and moments of inertia. Angular distribution coefficients of the {gamma}rays decaying out of the {sup 192}Hg SD band were determined using Eurogam data. These coefficients, as well as the spectral shape and multiplicity of the spectrum, are compared with the results of calculations, thereby providing a check on these calculations. From the measured decay multiplicity and the calculated average spin removed per photon (0.3 h), we deduce the average spin {bar I}{sub decay} removed by the {gamma} rays connecting SD and normal states. The spin I{sub SD} of the SD band from which the decay occurs is given by I{sub SD} = {bar I} decay + {bar I} ND, where {bar I} ND is the average spin removed by the normal yrast states. The state from which the major decay out of the SD band occurs is found to have spin 9.5 {plus_minus} 0.8 h. Since angular momentum is (quantized), this leads to a spin assignment of 9 or 10 h. The latter value is favored since the yrast band in the SD well must have only even spin values. This constitutes the first deduction of spin from data in the mass 150 and 190 regions. The spin of 10 h agrees with the spin which is inferred from a model, using the observed moment of inertia (Im){sup (2)}{omega}.

  10. The VLA Low-band Ionosphere and Transient Experiment (VLITE)

    Science.gov (United States)

    Clarke, Tracy; Peters, Wendy; Brisken, Walter; Giacintucci, Simona; Kassim, Namir; Polisensky, Emil; Helmboldt, Joseph; Richards, Emily E.; Erickson, Alan; Ray, Paul S.; Kerr, Matthew T.; Deneva, Julia; Coburn, William; Huber, Robert; Long, Jeff

    2018-01-01

    The VLA Low-band Ionosphere and Transient Experiment (VLITE, http://vlite.nrao.edu/ ) is a commensal low-frequency observing system that has been operational on the National Radio Astronomy Observatory's Karl G. Jansky Very Large Array (VLA) since late 2014. The separate optical paths of the prime-focus sub-GHz dipole feeds and the Cassegrain-focus 1-50 GHz feeds allow both systems to operate simultaneously with independent correlators. The initial 2.5 years of VLITE operation provided real-time correlation of 10 antennas across the 320-384 MHz band with a total observing time approaching 12,000 hours. During the summer of 2017, VLITE was upgraded to a total of 16 antennas (more than doubling the number of baselines) with enhanced correlator capabilities to enable correlation of the on-the-fly observing mode being used for the new NRAO VLA Sky Survey (VLASS).We present an overview of the VLITE system, including highlights of the complexities of a commensal observing program, sparse-array challenges, and scientific capabilities from our science-ready data pipeline. In the longer term, we seek a path to broadband expansion across all VLA antennas to develop a powerful new LOw Band Observatory (LOBO).

  11. Solid State KA-Band, Solid State W-Band and TWT Amplifiers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Phase I of the proposal describes plans to develop a state of the art transmitter for the W-Band and KA -Band Cloud Radar system. Our focus will be concentrated in...

  12. 47 CFR 90.1213 - Band plan.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Band plan. 90.1213 Section 90.1213 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES PRIVATE LAND... § 90.1213 Band plan. The following channel center frequencies are permitted to be aggregated for...

  13. Signature effects in 2-qp rotational bands

    International Nuclear Information System (INIS)

    Jain, A.K.; Goel, A.

    1992-01-01

    The authors briefly review the progress in understanding the 2-qp rotational bands in odd-odd nuclei. Signature effects and the phenomenon of signature inversion are discussed. The Coriolis coupling appears to have all the ingredients to explain the inversion. Some recent work on signature dependence in 2-qp bands of even-even nuclei is also discussed; interesting features are pointed out

  14. Low band gap polymers for organic photovoltaics

    DEFF Research Database (Denmark)

    Bundgaard, Eva; Krebs, Frederik C

    2007-01-01

    Low band gap polymer materials and their application in organic photovoltaics (OPV) are reviewed. We detail the synthetic approaches to low band gap polymer materials starting from the early methodologies employing quinoid homopolymer structures to the current state of the art that relies...

  15. Band mixing in /sup 160/Dy

    Energy Technology Data Exchange (ETDEWEB)

    Hasiza, M L; Singh, K; Sahota, H S [Punjabi Univ., Patiala (India). Dept. of Physics

    1982-11-01

    The intensities of the gamma transitions in /sup 160/Dy have been measured precisely by a 45 cc Ge(Li) detector. Unequal quadrupole moments for the ground and gamma vibrational bands have been proposed in order to remove the inconsistencies in the values of band mixing parameter Z sub(gamma) for this doubly even deformed nucleus of /sup 160/Dy.

  16. Convex Banding of the Covariance Matrix.

    Science.gov (United States)

    Bien, Jacob; Bunea, Florentina; Xiao, Luo

    2016-01-01

    We introduce a new sparse estimator of the covariance matrix for high-dimensional models in which the variables have a known ordering. Our estimator, which is the solution to a convex optimization problem, is equivalently expressed as an estimator which tapers the sample covariance matrix by a Toeplitz, sparsely-banded, data-adaptive matrix. As a result of this adaptivity, the convex banding estimator enjoys theoretical optimality properties not attained by previous banding or tapered estimators. In particular, our convex banding estimator is minimax rate adaptive in Frobenius and operator norms, up to log factors, over commonly-studied classes of covariance matrices, and over more general classes. Furthermore, it correctly recovers the bandwidth when the true covariance is exactly banded. Our convex formulation admits a simple and efficient algorithm. Empirical studies demonstrate its practical effectiveness and illustrate that our exactly-banded estimator works well even when the true covariance matrix is only close to a banded matrix, confirming our theoretical results. Our method compares favorably with all existing methods, in terms of accuracy and speed. We illustrate the practical merits of the convex banding estimator by showing that it can be used to improve the performance of discriminant analysis for classifying sound recordings.

  17. Signature splitting in two quasiparticle rotational bands of 180, 182 Ta

    Indian Academy of Sciences (India)

    quasiparticle rotor model. The phase as well as magnitudeof the experimentally observed signature splitting in K π = 1 + band of 180 Ta, which could not be explained in earlier calculations, is successfully reproduced. The conflict regarding placement of ...

  18. Utility of testing for monoclonal bands in serum of patients with suspected osteoporosis

    DEFF Research Database (Denmark)

    Abrahamsen, B.; Andersen, Ivan; Christensen, Susanne S.

    2005-01-01

    OBJECTIVE: To determine whether measuring monoclonal bands (M component) in serum should be part of the investigation of patients referred to osteoporosis clinics. DESIGN: Retrospective, cross sectional, observational study. SETTING: Referral centre for osteoporosis in a university hospital...

  19. Information retrieval from wide-band meteorological data - An example

    Science.gov (United States)

    Adelfang, S. I.; Smith, O. E.

    1983-01-01

    The methods proposed by Smith and Adelfang (1981) and Smith et al. (1982) are used to calculate probabilities over rectangles and sectors of the gust magnitude-gust length plane; probabilities over the same regions are also calculated from the observed distributions and a comparison is also presented to demonstrate the accuracy of the statistical model. These and other statistical results are calculated from samples of Jimsphere wind profiles at Cape Canaveral. The results are presented for a variety of wavelength bands, altitudes, and seasons. It is shown that wind perturbations observed in Jimsphere wind profiles in various wavelength bands can be analyzed by using digital filters. The relationship between gust magnitude and gust length is modeled with the bivariate gamma distribution. It is pointed out that application of the model to calculate probabilities over specific areas of the gust magnitude-gust length plane can be useful in aerospace design.

  20. Energy correlations for mixed rotational bands

    International Nuclear Information System (INIS)

    Doessing, T.

    1985-01-01

    A schematic model for the mixing of rotational bands above the yrast line in well deformed nuclei is considered. Many-particle configurations of a rotating mean field form basis bands, and these are subsequently mixed due to a two body residual interaction. The energy interval over which a basis band is spread out increases with increasing excitation energy above the yrast line. Conversely, the B(E2) matrix element for rotational decay out of one of the mixed band states is spread over an interval which is predicted to become more narrow with increasing excitation energy. Finally, the implication of band mixing for γ-ray energy correlations is briefly discussed. (orig.)

  1. Design of a side-band-separating heterodyne mixer for band 9 of ALMA

    NARCIS (Netherlands)

    Baryshev, AM; Kooi, J; Mena, FR; Lodewijk, CRJ; Wild, W

    2005-01-01

    A side-band-separating (SBS) heterodyne mixer has been designed for the Atacama Large Millimeter Array (ALMA) 602-720 GHz band, as it will present a great improvement over the current double-side-band configuration under development at the moment. Here we present design details and the results of

  2. Absorption band Q model for the earth

    International Nuclear Information System (INIS)

    Anderson, D.L.; Given, J.W.

    1982-01-01

    Body wave, surface wave, and normal mode data are used to place constraints on the frequency dependence of Q in the mantle. With a simple absorption band model it is possible to satisfy the shear sensitive data over a broad frequency range. The quality factor Q/sub s/(ω) is proportional to ω/sup α/ in the band and to ω and ω -1 at higher and lower frequencies, respectively, as appropriate for a relaxation mechanism with a spectrum of relaxation time. The parameters of the band are Q(min) = 80, α = 0.15, and width, 5 decades. The center of the band varies from 10 1 seconds in the upper mantle, to 1.6 x 10 3 seconds in the lower mantle. The shift of the band with depth is consistent with the expected effects of temperature, pressure and stress. High Q, regions of the mantle are attributed to a shift of the absorption band to longer periods. To satisfy the gravest fundamental spheroidal modes and the ScS data, the absorption band must shift back into the short-period seismic band at the base of the mantle. This may be due to a high temperature gradient or high shear stresses. A preliminary attempt is also made to specify bulk dissipation in the mantle and core. Specific features of the absorption band model are low Q in the body wave band at both the top and the base of the mantle, low Q for long-period body waves in the outer core, an inner core Q 2 that increases with period, and low Q/sub p//Q/sub s/ at short periods in the middle mantel. The short-period Q/sub s/ increases rapidly at 400 km and is relatively constant from this depth to 2400 km. The deformational Q of the earth at a period of 14 months is predicted to be 463

  3. Band-type microelectrodes for amperometric immunoassays

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ga-Yeon; Chang, Young Wook; Ko, Hyuk [Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of); Kang, Min-Jung [Korea Institute of Science and Technology (KIST), Seoul (Korea, Republic of); Pyun, Jae-Chul, E-mail: jcpyun@yonsei.ac.kr [Department of Materials Science and Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749 (Korea, Republic of)

    2016-07-20

    A band-type microelectrode was made using a parylene-N film as a passivation layer. A circular-type, mm-scale electrode with the same diameter as the band-type microelectrode was also made with an electrode area that was 5000 times larger than the band-type microelectrode. By comparing the amperometric signals of 3,5,3′,5′-tetramethylbenzidine (TMB) samples at different optical density (OD) values, the band-type microelectrode was determined to be 9 times more sensitive than the circular-type electrode. The properties of the circular-type and the band-type electrodes (e.g., the shape of their cyclic voltammograms, the type of diffusion layer used, and the diffusion layer thickness per unit electrode area) were characterized according to their electrode area using the COMSOL Multiphysics software. From these simulations, the band-type electrode was estimated to have the conventional microelectrode properties, even when the electrode area was 100 times larger than a conventional circular-type electrode. These results show that both the geometry and the area of an electrode can influence the properties of the electrode. Finally, amperometric analysis based on a band-type electrode was applied to commercial ELISA kits to analyze human hepatitis B surface antigen (hHBsAg) and human immunodeficiency virus (HIV) antibodies. - Highlights: • A band-type microelectrode was made using a parylene-N film as a passivation layer. • The band-type microelectrode was 14-times more sensitive than circular-type electrode. • The influence of geometry on microelectrode properties was simulated using COMSOL. • The band-type electrode was applied to ELISA kits for hHBsAg and hHIV-antibodies.

  4. Life test on indigenous s-band pulsed magnetron

    International Nuclear Information System (INIS)

    Wanmode, Y.D.; Shrivastava, P.; Hannurkar, P.R.

    1999-01-01

    A 2 MW S-band pulsed magnetron has been developed under joint collaboration between CAT and CEERI. In this development effort several lab prototypes were evaluated on 2 MW microwave test facility developed at CAT. One magnetron is subjected to life test. The present paper describes the setup and procedures used for life test. Various observations and corrections made during the life tests are also described. Results of the tests are discussed. (author)

  5. Imaging the Nanoscale Band Structure of Topological Sb

    OpenAIRE

    Soumyanarayanan, Anjan; Yee, Michael M.; He, Yang; Lin, Hsin; Gardner, Dillon R.; Bansil, Arun; Lee, Young S.; Hoffman, Jennifer E.

    2013-01-01

    Many promising building blocks of future electronic technology - including non-stoichiometric compounds, strongly correlated oxides, and strained or patterned films - are inhomogeneous on the nanometer length scale. Exploiting the inhomogeneity of such materials to design next-generation nanodevices requires a band structure probe with nanoscale spatial resolution. To address this demand, we report the first simultaneous observation and quantitative reconciliation of two candidate probes - La...

  6. Demosaicking Based on Optimization and Projection in Different Frequency Bands

    Directory of Open Access Journals (Sweden)

    Omer OsamaA

    2008-01-01

    Full Text Available Abstract A fast and effective iterative demosaicking algorithm is described for reconstructing a full-color image from single-color filter array data. The missing color values are interpolated on the basis of optimization and projection in different frequency bands. A filter bank is used to decompose an initially interpolated image into low-frequency and high-frequency bands. In the low-frequency band, a quadratic cost function is minimized in accordance with the observation that the low-frequency components of chrominance slowly vary within an object region. In the high-frequency bands, the high-frequency components of the unknown values are projected onto the high-frequency components of the known values. Comparison of the proposed algorithm with seven state-of-the-art demosaicking algorithms showed that it outperforms all of them for 20 images on average in terms of objective quality and that it is competitive with them from the subjective quality and complexity points of view.

  7. Relaxation and cross section effects in valence band photoemission spectroscopy

    International Nuclear Information System (INIS)

    McFeely, F.R.

    1976-09-01

    Various problems relating to the interpretation of valence band x-ray photoemission (XPS) spectra of solids are discussed. The experiments and calculations reported herein deal with the following questions: (1) To what extent do many-body effects manifest themselves in an XPS valence band spectrum, and thus invalidate a direct comparison between the photoemission energy distribution, I(E), and the density of states, N(E), calculated on the basis of ground-state one-electron theory. (2) The effect of the binding-energy-dependent photoemission cross section on I(E) at XPS energies. (3) In favorable cases indicated by (1) and (2) we examine the effect of the interaction of the crystal field with the apparent spin-orbit splittings of core levels observed in XPS spectra. (4) The use of tight binding band structure calculations to parameterize the electronic band structure from XPS and other data is described. (5) The use of high energy angle-resolved photoemission on oriented single crystals to gain orbital symmetry information is discussed. (6) The evolution of the shape of the photoemission energy distribution (of polycrystalline Cu) as a function of photon energy from 50 less than or equal h ω less than or equal 175 is discussed

  8. Broad-Band Analysis of Polar Motion Excitations

    Science.gov (United States)

    Chen, J.

    2016-12-01

    Earth rotational changes, i.e. polar motion and length-of-day (LOD), are driven by two types of geophysical excitations: 1) mass redistribution within the Earth system, and 2) angular momentum exchange between the solid Earth (more precisely the crust) and other components of the Earth system. Accurate quantification of Earth rotational excitations has been difficult, due to the lack of global-scale observations of mass redistribution and angular momentum exchange. The over 14-years time-variable gravity measurements from the Gravity Recovery and Climate Experiment (GRACE) have provided a unique means for quantifying Earth rotational excitations from mass redistribution in different components of the climate system. Comparisons between observed Earth rotational changes and geophysical excitations estimated from GRACE, satellite laser ranging (SLR) and climate models show that GRACE-derived excitations agree remarkably well with polar motion observations over a broad-band of frequencies. GRACE estimates also suggest that accelerated polar region ice melting in recent years and corresponding sea level rise have played an important role in driving long-term polar motion as well. With several estimates of polar motion excitations, it is possible to estimate broad-band noise variance and noise power spectra in each, given reasonable assumptions about noise independence. Results based on GRACE CSR RL05 solutions clearly outperform other estimates with the lowest noise levels over a broad band of frequencies.

  9. Severe neurological complication following adjustable gastric banding.

    Science.gov (United States)

    Martines, G; Musa, N; Aquilino, F; Capuano, P

    2018-01-01

    In the last years with the increase of bariatric surgery, first of all as a result of new indications, a rise in the incidence of nutrient-related complications has been observed. Currently little is known about the impact of post-bariatric malnutrition and neurological complications. Wernicke's encephalopathy is a severe neurological syndrome which occurs as a result of thiamine deficiency. Wernicke-Korsakoff syndrome must be considered a serious neurological complication of bariatric surgery with significant morbidity and mortality, with rapidly progressing neurological symptoms, and must be treated immediately. We report the case of a 35 years-old male patient, affected by morbid obesity, anxious-depressive syndrome and alcohol use disorder, who after adjustable gastric banding implanted in another hospital developed a severe malnutrition and neurological syndrome. The patient showed poor adherence to the follow-up and to the dietary indications and after all, we needed to place a PEG for enteral nutrition in order to resolve the malnutrition condition and the neurological syndrome. Our experience emphasizes that preoperative selection and assessment of a patient's nutritional status according to guidelines, is required to identify potential problems, and that bariatric surgeons or physicians caring for patient who have undergone bariatric surgery should be familiar with the constellation of nutritional and neurological disorder that may occur after surgery. We want to remark the importance of preoperative selection of the patients, the follow-up and the cooperation between patient and physician in order to obtain the best result and avoid severe complications.

  10. Band structure studies of actinide systems

    International Nuclear Information System (INIS)

    Koelling, D.D.

    1976-01-01

    The nature of the f-orbitals in an actinide system plays a crucial role in determining the electronic properties. It has long been realized that when the actinide separation is small enough for the f-orbitals to interact directly, the system will exhibit itinerant electron properties: an absence of local moment due to the f-orbitals and sometimes even superconductivity. However, a number of systems with the larger actinide separation that should imply local moment behavior also exhibit intinerant properties. Such systems (URh 3 , UIr 3 , UGe 3 , UC) were examined to learn something about the other f-interactions. A preliminary observation made is that there is apparently a very large and ansiotropic mass enhancement in these systems. There is very good reason to believe that this is not solely due to large electron--electron correlations but to a large electron--phonon interaction as well. These features of the ''non-magnetic'', large actinide separation systems are discussed in light of our results to date. Finally, the results of some recent molecular calculations on actinide hexafluorides are used to illustrate the shielding effects on the intra-atomic Coulomb term U/sub f-f/ which would appear in any attempt to study the formation of local moments. As one becomes interested in materials for which a band structure is no longer an adequate model, this screened U/sub ff/ is the significant parameter and efforts must be made to evaluate it in solid state systems

  11. Dilatancy induced ductile-brittle transition of shear band in metallic glasses

    Science.gov (United States)

    Zeng, F.; Jiang, M. Q.; Dai, L. H.

    2018-04-01

    Dilatancy-generated structural disordering, an inherent feature of metallic glasses (MGs), has been widely accepted as the physical mechanism for the primary origin and structural evolution of shear banding, as well as the resultant shear failure. However, it remains a great challenge to determine, to what degree of dilatation, a shear banding will evolve into a runaway shear failure. In this work, using in situ acoustic emission monitoring, we probe the dilatancy evolution at the different stages of individual shear band in MGs that underwent severely plastic deformation by the controlled cutting technology. A scaling law is revealed that the dilatancy in a shear band is linearly related to its evolution degree. A transition from ductile-to-brittle shear bands is observed, where the formers dominate stable serrated flow, and the latter lead to a runaway instability (catastrophe failure) of serrated flow. To uncover the underlying mechanics, we develop a theoretical model of shear-band evolution dynamics taking into account an atomic-scale deformation process. Our theoretical results agree with the experimental observations, and demonstrate that the atomic-scale volume expansion arises from an intrinsic shear-band evolution dynamics. Importantly, the onset of the ductile-brittle transition of shear banding is controlled by a critical dilatation.

  12. Two-band superconductor magnesium diboride

    International Nuclear Information System (INIS)

    Xi, X X

    2008-01-01

    This review focuses on the most important features of the 40 K superconductor MgB 2 -the weakly interacting multiple bands (the σ and π bands) and the distinct multiple superconducting energy gaps (the σ and π gaps). Even though the pairing mechanism of superconductor MgB 2 is the conventional electron-phonon coupling, the prominent influence of the two bands and two gaps on its properties sets it apart from other superconductors. It leads to markedly different behaviors in upper critical field, vortex structure, magnetoresistance and many other superconducting and normal-state properties in MgB 2 from single-band superconductors. Further, it gives rise to new physics that does not exist in single-band superconductors, such as the internal Josephson effects between the two order parameters. These unique phenomena depend sensitively on scattering inside and between the two bands, and the intraband and interband scattering can be modified by chemical substitution and irradiation. MgB 2 has brought unprecedented attention to two-band superconductivity, which has been found to exist in other old and new superconductors. The legacy of MgB 2 will be long lasting because of this, as well as the lessons it teaches in terms of the search for new phonon-mediated higher T c superconductors

  13. Dual-band frequency selective surface with large band separation and stable performance

    International Nuclear Information System (INIS)

    Zhou Hang; Qu Shao-Bo; Lin Bao-Qin; Wang Jia-Fu; Ma Hua; Zhang Jie-Qiu; Peng Wei-Dong; Bai Peng; Wang Xu-Hua; Xu Zhuo

    2012-01-01

    A new technique of designing a dual-band frequency selective surface with large band separation is presented. This technique is based on a delicately designed topology of L- and Ku-band microwave filters. The two band-pass responses are generated by a capacitively-loaded square-loop frequency selective surface and an aperture-coupled frequency selective surface, respectively. A Faraday cage is located between the two frequency selective surface structures to eliminate undesired couplings. Based on this technique, a dual-band frequency selective surface with large band separation is designed, which possesses large band separation, high selectivity, and stable performance under various incident angles and different polarizations. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  14. Band-to-band tunneling in Γ valley for Ge source lateral tunnel field effect transistor: Thickness scaling

    Science.gov (United States)

    Jain, Prateek; Rastogi, Priyank; Yadav, Chandan; Agarwal, Amit; Chauhan, Yogesh Singh

    2017-07-01

    The direct and indirect valleys in Germanium (Ge) are separated by a very small offset, which opens up the prospect of direct tunneling in the Γ valley of an extended Ge source tunnel field effect transistor (TFET). We explore the impact of thickness scaling of extended Ge source lateral TFET on the band to band tunneling (BTBT) current. The Ge source is extended inside the gate by 2 nm to confine the tunneling in Ge only. We observe that as the thickness is scaled, the band alignment at the Si/Ge heterojunction changes significantly, which results in an increase in Ge to Si BTBT current. Based on density functional calculations, we first obtain the band structure parameters (bandgap, effective masses, etc.) for the Ge and Si slabs of varying thickness, and these are then used to obtain the thickness dependent Kane's BTBT tunneling parameters. We find that electrostatics improves as the thickness is reduced in the ultra-thin Ge film ( ≤ 10 nm). The ON current degrades as we scale down in thickness; however, the subthreshold slope ( S S AVG ) improves remarkably with thickness scaling due to subsurface BTBT. We predict that 8 nm thin devices offer the best option for optimized ON current and S S AVG .

  15. Visible bands of ammonia: band strengths, curves of growth, and the spatial distribution of ammonia on Jupiter

    International Nuclear Information System (INIS)

    Lutz, B.L.; Owen, T.

    1980-01-01

    We report room-temperature laboratory studies of the 5520 A (6ν 1 ) and 6475 A (5ν 1 ) bands of self-broadened ammonia at column densities ranging from 1.7--435.7 meter-amagats (m-am). Detailed equivalent-width measurements at 24 different pressure-pathlength combinations corresponding to four pressures between 44 and 689 torr and pathlengths between 32 and 512 m are used to determin curves of growth and integrated band strengths. The band strengths for the 6ν 1 and 5ν 1 overtones are 5520 A: S=0.096 +- 0.005 cm -1 (m-am) -1 and 6475 A: S=0.63 +- 0.03 cm -1 (m-am) -1 , respectively.Using these band strengths and curves of growth, we analyze new spatially resolved spectra of Jupiter showing a nonhomogeneous distribution of ammonia in the Jovian atmosphere. The observed variations in the CH 4 /NH 3 mixing ratio are interpreted as evidence of altitude-dependent depletion of ammonia in the atmosphere

  16. Band-to-Band Tunneling-Dominated Thermo-Enhanced Field Electron Emission from p-Si/ZnO Nanoemitters.

    Science.gov (United States)

    Huang, Zhizhen; Huang, Yifeng; Xu, Ningsheng; Chen, Jun; She, Juncong; Deng, Shaozhi

    2018-06-13

    Thermo-enhancement is an effective way to achieve high performance field electron emitters, and enables the individually tuning on the emission current by temperature and the electron energy by voltage. The field emission current from metal or n-doped semiconductor emitter at a relatively lower temperature (i.e., current saturation was observed in the thermo-enhanced field emission measurements. The emission current density showed about ten-time enhancement (from 1.31 to 12.11 mA/cm 2 at 60.6 MV/m) by increasing the temperature from 323 to 623 K. The distinctive performance did not agree with the interband excitation mechanism but well-fit to the band-to-band tunneling model. The strong thermo-enhancement was proposed to be benefit from the increase of band-to-band tunneling probability at the surface portion of the p-Si/ZnO nanojunction. This work provides promising cathode for portable X-ray tubes/panel, ionization vacuum gauges and low energy electron beam lithography, in where electron-dose control at a fixed energy is needed.

  17. Hyperspectral band selection and classification of Hyperion image of Bhitarkanika mangrove ecosystem, eastern India

    Science.gov (United States)

    Ashokkumar, L.; Shanmugam, S.

    2014-10-01

    Tropical mangrove forests along the coast evolve dynamically due to constant changes in the natural ecosystem and ecological cycle. Remote sensing has paved the way for periodic monitoring and conservation of such floristic resources, compared to labour intensive in-situ observations. With the laboratory quality image spectra obtained from hyperspectral image data, species level discrimination in habitats and ecosystems is attainable. One of the essential steps before classification of hyperspectral image data is band selection. It is important to eliminate the redundant bands to mitigate the problems of Hughes effect that are likely to affect further image analysis and classification accuracy. This paper presents a methodology for the selection of appropriate hyperspectral bands from the EO-1 Hyperion image for the identification and mapping of mangrove species and coastal landcover types in the Bhitarkanika coastal forest region, eastern India. Band selection procedure follows class based elimination procedure and the separability of the classes are tested in the band selection process. Individual bands are de-correlated and redundant bands are removed from the bandwise correlation matrix. The percent contribution of class variance in each band is analysed from the factors of PCA component ranking. Spectral bands are selected from the wavelength groups and statistically tested. Further, the band selection procedure is compared with similar techniques (Band Index and Mutual information) for validation. The number of bands in the Hyperion image was reduced from 196 to 88 by the Factor-based ranking approach. Classification was performed by Support Vector Machine approach. It is observed that the proposed Factor-based ranking approach performed well in discriminating the mangrove species and other landcover units compared to the other statistical approaches. The predominant mangrove species Heritiera fomes, Excoecaria agallocha and Cynometra ramiflora are spectral

  18. Asymmetric acoustic transmission in multiple frequency bands

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hong-xiang, E-mail: jsdxshx@ujs.edu.cn [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China); State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190 (China); Yuan, Shou-qi, E-mail: Shouqiy@ujs.edu.cn [Research Center of Fluid Machinery Engineering and Technology, Jiangsu University, Zhenjiang 212013 (China); Zhang, Shu-yi [Laboratory of Modern Acoustics, Institute of Acoustics, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093 (China)

    2015-11-23

    We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices.

  19. Asymmetric acoustic transmission in multiple frequency bands

    International Nuclear Information System (INIS)

    Sun, Hong-xiang; Yuan, Shou-qi; Zhang, Shu-yi

    2015-01-01

    We report both experimentally and numerically that the multi-band device of the asymmetric acoustic transmission is realized by placing two periodic gratings with different periods on both sides of two brass plates immersed in water. The asymmetric acoustic transmission can exist in four frequency bands below 1500 kHz, which arises from the interaction between various diffractions from the two gratings and Lamb modes in the brass plates immersed in water. The results indicate that the device has the advantages of multiple band, broader bandwidth, and simpler structure. Our finding should have great potential applications in ultrasonic devices

  20. Exact nonparametric confidence bands for the survivor function.

    Science.gov (United States)

    Matthews, David

    2013-10-12

    A method to produce exact simultaneous confidence bands for the empirical cumulative distribution function that was first described by Owen, and subsequently corrected by Jager and Wellner, is the starting point for deriving exact nonparametric confidence bands for the survivor function of any positive random variable. We invert a nonparametric likelihood test of uniformity, constructed from the Kaplan-Meier estimator of the survivor function, to obtain simultaneous lower and upper bands for the function of interest with specified global confidence level. The method involves calculating a null distribution and associated critical value for each observed sample configuration. However, Noe recursions and the Van Wijngaarden-Decker-Brent root-finding algorithm provide the necessary tools for efficient computation of these exact bounds. Various aspects of the effect of right censoring on these exact bands are investigated, using as illustrations two observational studies of survival experience among non-Hodgkin's lymphoma patients and a much larger group of subjects with advanced lung cancer enrolled in trials within the North Central Cancer Treatment Group. Monte Carlo simulations confirm the merits of the proposed method of deriving simultaneous interval estimates of the survivor function across the entire range of the observed sample. This research was supported by the Natural Sciences and Engineering Research Council (NSERC) of Canada. It was begun while the author was visiting the Department of Statistics, University of Auckland, and completed during a subsequent sojourn at the Medical Research Council Biostatistics Unit in Cambridge. The support of both institutions, in addition to that of NSERC and the University of Waterloo, is greatly appreciated.

  1. Discrete Analysis of Damage and Shear Banding in Argillaceous Rocks

    Science.gov (United States)

    Dinç, Özge; Scholtès, Luc

    2018-05-01

    A discrete approach is proposed to study damage and failure processes taking place in argillaceous rocks which present a transversely isotropic behavior. More precisely, a dedicated discrete element method is utilized to provide a micromechanical description of the mechanisms involved. The purpose of the study is twofold: (1) presenting a three-dimensional discrete element model able to simulate the anisotropic macro-mechanical behavior of the Callovo-Oxfordian claystone as a particular case of argillaceous rocks; (2) studying how progressive failure develops in such material. Material anisotropy is explicitly taken into account in the numerical model through the introduction of weakness planes distributed at the interparticle scale following predefined orientation and intensity. Simulations of compression tests under plane-strain and triaxial conditions are performed to clarify the development of damage and the appearance of shear bands through micromechanical analyses. The overall mechanical behavior and shear banding patterns predicted by the numerical model are in good agreement with respect to experimental observations. Both tensile and shear microcracks emerging from the modeling also present characteristics compatible with microstructural observations. The numerical results confirm that the global failure of argillaceous rocks is well correlated with the mechanisms taking place at the local scale. Specifically, strain localization is shown to directly result from shear microcracking developing with a preferential orientation distribution related to the orientation of the shear band. In addition, localization events presenting characteristics similar to shear bands are observed from the early stages of the loading and might thus be considered as precursors of strain localization.

  2. Lunar Noise-Temperature Increase Measurements at S-Band, X-Band, and Ka-Band Using a 34-Meter-Diameter Beam-Waveguide Antenna

    Science.gov (United States)

    Morabito, D. D.

    2006-08-01

    The Moon radiates energy at infrared and microwave wavelengths, in addition to reflecting sunlight at optical wavelengths. As a result, an antenna pointed at or near the Moon will cause an increase in receiver noise temperature that needs to be accounted for in telemetry, radio science, or ranging link budgets. The Deep Space Network may be required to use its antennas in future lunar robotic or human missions, and thus it is important to understand the nature of this temperature increase as a function of observing frequency, lunar phase, and angular offset of the antenna beam from the center of the lunar disk. This article quantifies such a set of measurements acquired at DSS 13, a 34-m-diameter research and development beam-waveguide antenna located at Goldstone, California, at three different telecommunication frequencies, S-band (2.3 GHz), X-band (8.4 GHz), and Ka-band (32 GHz), over a wide range of lunar phase, for both disk-centered and limb-centered positions of the antenna beam.

  3. A Multiple-Channel Sub-Band Transient Detection System

    Energy Technology Data Exchange (ETDEWEB)

    David A. Smith

    1998-11-01

    We have developed a unique multiple-channel sub-band transient detection system to record transient electromagnetic signals in carrier-dominated radio environments; the system has been used to make unique observations of weak, transient HF signals. The detection system has made these observations possible through improved sensitivity compared to conventional broadband transient detection systems; the sensitivity improvement is estimated to be at least 20 dB. The increase in sensitivity has been achieved through subdivision of the band of interest (an 18 MHz tunable bandwidth) into eight sub-band independent detection channels, each with a 400 kHz bandwidth and its own criteria. The system generates a system trigger signal when a predetermined number of channels (typically five) trigger within a predetermined window of time (typically 100 ~s). Events are recorded with a broadband data acquisition system sampling at 50 or 100 Msample/s, so despite the fact that the detection system operates on portions of the signal confined to narrow bands, data acquisition is broadband. Between May and September of 1994, the system was used to detect and record over six thousand transient events in the frequency band from 3 to 30 MHz. Approximately 500 of the events have been characterized as paired bursts of radio noise with individual durations of 2 to 10 ps and separations between the bursts of 5 to 160 ps. The paired transients are typically 5 to 40 dB brighter than the background electromagnetic spectrum between carrier signals. We have termed these events SubIonospheric Pulse Pairs (SIPPS) and presently have no explanation as to their source. Our observations of SIPPS resemble observations of TransIonospheric Pulse Pairs (TIPPs) recorded by the Blackboard instrument on the ALEXIS satellite; the source of TIPP events is also unknown. Most of the recorded SIPP events do not exhibit frequency dispersion, implying propagation along a line-of-sight (groundwave) path; but seven of

  4. Frequency band analysis of muscle activation during cycling to exhaustion

    Directory of Open Access Journals (Sweden)

    Fernando Diefenthaeler

    2012-04-01

    Full Text Available DOI: http://dx.doi.org/10.5007/1980-0037.2012v14n3p243 Lower limb muscles activation was assessed during cycling to exhaustion using frequency band analysis. Nine cyclists were evaluated in two days. On the first day, cyclists performed a maximal incremental cycling exercise to measure peak power output, which was used on the second day to define the workload for a constant load time to exhaustion cycling exercise (maximal aerobic power output from day 1. Muscle activation of vastus lateralis (VL, long head of biceps femoris (BF, lateral head of gastrocnemius (GL, and tibialis anterior (TA from the right lower limb was recorded during the time to exhaustion cycling exercise. A series of nine band-pass Butterworth digital filters was used to analyze muscle activity amplitude for each band. The overall amplitude of activation and the high and low frequency components were defined to assess the magnitude of fatigue effects on muscle activity via effect sizes. The profile of the overall muscle activation during the test was analyzed using a second order polynomial, and the variability of the overall bands was analyzed by the coefficient of variation for each muscle in each instant of the test. Substantial reduction in the high frequency components of VL and BF activation was observed. The overall and low frequency bands presented trivial to small changes for all muscles. High relationship between the second order polynomial fitting and muscle activity was found (R2 > 0.89 for all muscles. High variability (~25% was found for muscle activation at the four instants of the fatigue test. Changes in the spectral properties of the EMG signal were only substantial when extreme changes in fatigue state were induced.

  5. Unidentified bands lambda lambda 6830, 7088 in symbiotic stars

    Energy Technology Data Exchange (ETDEWEB)

    Allen, D A [Anglo-Australian Observatory, Epping (Australia)

    1980-01-01

    About 60 stars are known which show broad emission bands centred at wavelengths of 6830 and 7088 A. The stars are all classified as symbiotic, since they combine high-excitation emission and M-type absorption spectra. From the behaviour of the bands in the evolution of slow novae as they approach the symbiotic phase, and from the occurrence of the bands in stars of different excitation, it is concluded that the ions responsible have ionization potentials near 100 eV. The similarity of behaviour and profile of the two suggests that both arise in the same species. No suitable identification appears possible at this time, because of the lack of data on highly ionized species. Arguments are presented which narrow the range of possibilities, the most notable argument being the absence of O VI emission. It is suggested that Fe VII or Fe VI may be responsible. In particular, it is recommended that transitions from the z/sup 3/P/sup 0/ and z/sup 1/F/sup 0/ levels of Fe VII be examined in detail. The differing, and time-varying profiles of the 6830 and 7088 bands in the stars observed are best explained in terms of velocity broadening. Velocities in excess of 1000 km s/sup -1/ are present. Rotation is a more credible form of the mass motion than expansion, because of the tendency to double profiles in these bands. If rotation is responsible, these velocities imply that the objects central to the emission nebulae are more compact than main sequence stars.

  6. Chromosome Banding in Amphibia. XXXII. The Genus Xenopus (Anura, Pipidae).

    Science.gov (United States)

    Schmid, Michael; Steinlein, Claus

    2015-01-01

    Mitotic chromosomes of 16 species of the frog genus Xenopus were prepared from kidney and lung cell cultures. In the chromosomes of 7 species, high-resolution replication banding patterns could be induced by treating the cultures with 5-bromodeoxyuridine (BrdU) and deoxythymidine (dT) in succession, and in 6 of these species the BrdU/dT-banded chromosomes could be arranged into karyotypes. In the 3 species of the clade with 2n = 20 and 4n = 40 chromosomes (X. tropicalis, X. epitropicalis, X. new tetraploid 1), as well as in the 3 species with 4n = 36 chromosomes (X. laevis, X. borealis, X. muelleri), the BrdU/dT-banded karyotypes show a high degree of homoeology, though differences were detected between these groups. Translocations, inversions, insertions or sex-specific replication bands were not observed. Minor replication asynchronies found between chromosomes probably involve heterochromatic regions. BrdU/dT replication banding of Xenopus chromosomes provides the landmarks necessary for the exact physical mapping of genes and repetitive sequences. FISH with an X. laevis 5S rDNA probe detected multiple hybridization sites at or near the long-arm telomeric regions in most chromosomes of X. laevis and X. borealis, whereas in X. muelleri, the 5S rDNA sequences are located exclusively at the long-arm telomeres of a single chromosome pair. Staining with the AT base pair-specific fluorochrome quinacrine mustard revealed brightly fluorescing heterochromatic regions in the majority of X. borealis chromosomes which are absent in other Xenopus species.

  7. Valence band structure of binary chalcogenide vitreous semiconductors by high-resolution XPS

    International Nuclear Information System (INIS)

    Kozyukhin, S.; Golovchak, R.; Kovalskiy, A.; Shpotyuk, O.; Jain, H.

    2011-01-01

    High-resolution X-ray photoelectron spectroscopy (XPS) is used to study regularities in the formation of valence band electronic structure in binary As x Se 100−x , As x S 100−x , Ge x Se 100−x and Ge x S 100−x chalcogenide vitreous semiconductors. It is shown that the highest occupied energetic states in the valence band of these materials are formed by lone pair electrons of chalcogen atoms, which play dominant role in the formation of valence band electronic structure of chalcogen-rich glasses. A well-expressed contribution from chalcogen bonding p electrons and more deep s orbitals are also recorded in the experimental valence band XPS spectra. Compositional dependences of the observed bands are qualitatively analyzed from structural and compositional points of view.

  8. Valence band structure of binary chalcogenide vitreous semiconductors by high-resolution XPS

    Energy Technology Data Exchange (ETDEWEB)

    Kozyukhin, S., E-mail: sergkoz@igic.ras.ru [Russian Academy of Science, Institute of General and Inorganic Chemistry (Russian Federation); Golovchak, R. [Lviv Scientific Research Institute of Materials of SRC ' Carat' (Ukraine); Kovalskiy, A. [Lehigh University, Department of Materials Science and Engineering (United States); Shpotyuk, O. [Lviv Scientific Research Institute of Materials of SRC ' Carat' (Ukraine); Jain, H. [Lehigh University, Department of Materials Science and Engineering (United States)

    2011-04-15

    High-resolution X-ray photoelectron spectroscopy (XPS) is used to study regularities in the formation of valence band electronic structure in binary As{sub x}Se{sub 100-x}, As{sub x}S{sub 100-x}, Ge{sub x}Se{sub 100-x} and Ge{sub x}S{sub 100-x} chalcogenide vitreous semiconductors. It is shown that the highest occupied energetic states in the valence band of these materials are formed by lone pair electrons of chalcogen atoms, which play dominant role in the formation of valence band electronic structure of chalcogen-rich glasses. A well-expressed contribution from chalcogen bonding p electrons and more deep s orbitals are also recorded in the experimental valence band XPS spectra. Compositional dependences of the observed bands are qualitatively analyzed from structural and compositional points of view.

  9. Bands dispersion and charge transfer in β-BeH2

    Science.gov (United States)

    Trivedi, D. K.; Galav, K. L.; Joshi, K. B.

    2018-04-01

    Predictive capabilities of ab-initio method are utilised to explore bands dispersion and charge transfer in β-BeH2. Investigations are carried out using the linear combination of atomic orbitals method at the level of density functional theory. The crystal structure and related parameters are settled by coupling total energy calculations with the Murnaghan equation of state. Electronic bands dispersion from PBE-GGA is reported. The PBE-GGA, and PBE0 hybrid functional, show that β-BeH2 is a direct gap semiconductor with 1.18 and 2.40 eV band gap. The band gap slowly decreases with pressure and beyond l00 GPa overlap of conduction and valence bands at the r point is observed. Charge transfer is studied by means of Mullikan population analysis.

  10. Acoustic band gaps of the woodpile sonic crystal with the simple cubic lattice

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Liang-Yu; Chen, Lien-Wen, E-mail: chenlw@mail.ncku.edu.t [Department of Mechanical Engineering, National Cheng Kung University, Tainan 70101, Taiwan (China)

    2011-02-02

    This study theoretically and experimentally investigates the acoustic band gap of a three-dimensional woodpile sonic crystal. Such crystals are built by blocks or rods that are orthogonally stacked together. The adjacent layers are perpendicular to each other. The woodpile structure is embedded in air background. Their band structures and transmission spectra are calculated using the finite element method with a periodic boundary condition. The dependence of the band gap on the width of the stacked rods is discussed. The deaf bands in the band structure are observed by comparing with the calculated transmission spectra. The experimental transmission spectra for the {Gamma}-X and {Gamma}-X' directions are also presented. The calculated results are compared with the experimental results.

  11. Atomistic simulation study of the shear-band deformation mechanism in Mg-Cu metallic glasses

    DEFF Research Database (Denmark)

    Bailey, Nicholas; Schiøtz, Jakob; Jacobsen, Karsten Wedel

    2006-01-01

    We have simulated plastic deformation of a model Mg-Cu metallic glass in order to study shear banding. In uniaxial tension, we find a necking instability occurs rather than shear banding. We can force the latter to occur by deforming in plane strain, forbidding the change of length in one...... of the transverse directions. Furthermore, in most of the simulations a notch is used to initiate shear bands, which lie at a 45 degrees angle to the tensile loading direction. The shear bands are characterized by the Falk and Langer local measure of plastic deformation D-min(2), averaged here over volumes...... observe a slight decrease in density, up to 1%, within the shear band, which is consistent with notions of increased free volume or disorder within a plastically deforming amorphous material....

  12. Line shape and thermal Kinetics analysis of the Fe2+ -band in Brazilian Green beryl

    International Nuclear Information System (INIS)

    Isotani, S.; Furtado, W.; Antonini, R.; Dias, O.L.

    1988-03-01

    The optical absorption spectra study through isothermal treatments of the σ- and Π-polarized bands of Fe 2+ -band is reported. It was shown a linear correlation between these bands through thermal treatments. Irradiation with γ-rays from 60 Co, showed the decrease of this band. The line shape analysis and the discussions lend us to assign the Π- and σ-polarized bands to Fe 2+ ions in the structural channels with and without neighbour water molecules, respectively. The kinetics analysis through a ''bimolecular-like'' model gives untrapping parameter with Arrhenius behavior. The retrapping and recombination parameters showed a behavior proportional to T 1/2 - T 1/2 o which were explained from free electron distribution of velocities and minimum untrapped electron energy due to a potential barrier of the trap. The kinetics cut-off temperature, T 0 , agrees with the previous experimental observation. (author) [pt

  13. Intrinsic states and rotational bands in 177Pt

    International Nuclear Information System (INIS)

    Dracoulis, G.D.; Fabricius, B.; Bark, R.A.; Stuchbery, A.E.; Popescu, D.G.; Kibedi, T.

    1989-11-01

    The 149 Sm ( 32 S,4n) 177 Pt reaction has been used to populate excited states in the neutron-deficient nucleus 177 Pt. Rotational bands based on intrinsic states assigned to the 1/2-[521], 5/2-[521] and (mixed) 7/2+ [633] Nilsson configurations have been observed. In contrast to the neighbou-ring even isotope 176 Pt, anomalies attributed to shape co-existence at low spin have not been observed. Implications for the deformation of 177 Pt are discussed together with the systematics of intrinsic states in this region, and alignments and other properties of N=99 nuclei. 37 refs., 15 figs., 3 tabs

  14. Broad-band spectrophotometry of HAT-P-32 b

    DEFF Research Database (Denmark)

    Mallonn, M.; Bernt, I.; Herrero, E.

    2016-01-01

    Multicolour broad-band transit observations offer the opportunity to characterize the atmosphere of an extrasolar planet with small- to medium-sized telescopes. One of the most favourable targets is the hot Jupiter HAT-P-32 b. We combined 21 new transit observations of this planet with 36 previou...... makes a recent tentative detection of a scattering feature less likely. Instead, the available spectral measurements of HAT-P-32 b favour a completely flat spectrum from the near-UV to the near-IR. A plausible interpretation is a thick cloud cover at high altitudes....

  15. Intermediate band mobility in heavily titanium-doped silicon layers

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez-Diaz, G.; Olea, J.; Martil, I.; Pastor, D. [Dpto. de Fisica Aplicada III (Electricidad y Electronica), Facultad de Ciencias Fisicas, Universidad Complutense de Madrid, 28040 Madrid (Spain); Marti, A.; Antolin, E.; Luque, A [Instituto de Energia Solar, Universidad Politecnica de Madrid, Escuela Tecnica Superior de Ingenieros de Telecomunicacion, Ciudad Universitaria sn, 28040 Madrid (Spain)

    2009-09-15

    The sheet resistance and the Hall mobility of high-purity Si wafers, in whose surface Ti atoms are implanted and laser annealed reaching concentrations above 10{sup 21} cm{sup -3}, are measured in the 90-370 K range. Below 240 K, an unconventional behavior is observed that is well explained on the basis of the appearance of an intermediate band (IB) region able to form a blocking junction with the substrate and of the appearance of an IB conduction. Explanations based on ordinary device physics fail to justify all the unconventional behavior of the characteristics observed. (author)

  16. Silicone rubber band for laparoscopic tubal sterilization.

    Science.gov (United States)

    Ansari, A H; Sealey, R M; Gay, J W; Kang, I

    1977-12-01

    In 1974, Yoon and associates (Am J Obstet Gynecol 120:132, 1974) described a new approach in which laparoscopic tubal occlusion was accomplished by utilizing the silicone rubber band technique. Recognizing the great advantages of the new technique in eliminating potential thermal injury associated with electrocoagulation, the authors have utilized the Yoon silicone rubber band technique in these institutions over the past 20 months. Thus far the procedure has been performed in 304 patients without any major complications. In the hope of eliminating and/or reducing possible pregnancy-failure rates, in 110 cases. In addition to application of the silicone band, the tube within the band was transected with non-electrical Seigler biopsy forceps. This, we believe, should provide an interesting long-term comparative study.

  17. Microbial processes in banded iron formation deposition

    DEFF Research Database (Denmark)

    Posth, Nicole; Konhauser, Kurt; Kappler, Andreas

    2013-01-01

    , remains unresolved. Evidence of an anoxic Earth with only localized oxic areas until the Great Oxidation Event ca 2·45 to 2·32 Ga makes the investigation of O2-independent mechanisms for banded iron formation deposition relevant. Recent studies have explored the long-standing proposition that Archean......Banded iron formations have been studied for decades, particularly regarding their potential as archives of the Precambrian environment. In spite of this effort, the mechanism of their deposition and, specifically, the role that microbes played in the precipitation of banded iron formation minerals...... banded iron formations may have been formed, and diagenetically modified, by anaerobic microbial metabolisms. These efforts encompass a wide array of approaches including isotope, ecophysiological and phylogeny studies, molecular and mineral marker analysis, and sedimentological reconstructions. Herein...

  18. Simulating Precambrian banded iron formation diagenesis

    DEFF Research Database (Denmark)

    Posth, Nicole R.; K??hler, Inga; D. Swanner, Elizabeth

    2013-01-01

    Post-depositional diagenetic alteration makes the accurate interpretation of key precipitation processes in ancient sediments, such as Precambrian banded iron formations (BIFs), difficult. While microorganisms are proposed as key contributors to BIF deposition, the diagenetic transformation...

  19. The Novel Microwave Stop-Band Filter

    Directory of Open Access Journals (Sweden)

    R. E. Chernobrovkin

    2008-01-01

    Full Text Available The stop-band filter with the new band-rejection element is proposed. The element is a coaxial waveguide with the slot in the centre conductor. In the frame of this research, the numerical and experimental investigations of the amplitude-frequency characteristics of the filter are carried out. It is noted that according to the slot parameters the two typical resonances (half-wave and quarter-wave can be excited. The rejection band of the single element is defined by the width, depth, and dielectric filling of the slot. Fifth-order Chebyshev filter utilizing the aforementioned element is also synthesized, manufactured, and tested. The measured and simulated results are in good agreement. The experimental filter prototype exhibits the rejection band 0.86 GHz at the level −40 dB.

  20. The cellular approach to band structure calculations

    International Nuclear Information System (INIS)

    Verwoerd, W.S.

    1982-01-01

    A short introduction to the cellular approach in band structure calculations is given. The linear cellular approach and its potantial applicability in surface structure calculations is given some consideration in particular

  1. Full L-S Band Telemetry System

    National Research Council Canada - National Science Library

    Jensen, Michael

    2001-01-01

    Recent changes in spectrum availability as well as higher demands for spectrum have motivated the development of telemetry transmit systems capable of fully operating over both L and S telemetry bands...

  2. Full L-S Band Telemetry System

    National Research Council Canada - National Science Library

    Jensen, Michael

    2003-01-01

    Recent changes in spectrum availability as well as higher demands for spectrum have motivated the development of telemetry transmit systems capable of fully operating over both L and S telemetry bands...

  3. Full L-S Band Telemetry System

    National Research Council Canada - National Science Library

    Jensen, Michael

    2002-01-01

    Recent changes in spectrum availability as well as higher demands for spectrum have motivated the development of telemetry transmit systems capable of fully operating over both L and S telemetry bands...

  4. Deployable Ka-Band Reflectarray, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Tyvak, in collaboration with UCLA, proposes a novel approach to the challenge of creating a large reflector for Ka-band high data rate links. We propose to attach...

  5. Confidence bands for inverse regression models

    International Nuclear Information System (INIS)

    Birke, Melanie; Bissantz, Nicolai; Holzmann, Hajo

    2010-01-01

    We construct uniform confidence bands for the regression function in inverse, homoscedastic regression models with convolution-type operators. Here, the convolution is between two non-periodic functions on the whole real line rather than between two periodic functions on a compact interval, since the former situation arguably arises more often in applications. First, following Bickel and Rosenblatt (1973 Ann. Stat. 1 1071–95) we construct asymptotic confidence bands which are based on strong approximations and on a limit theorem for the supremum of a stationary Gaussian process. Further, we propose bootstrap confidence bands based on the residual bootstrap and prove consistency of the bootstrap procedure. A simulation study shows that the bootstrap confidence bands perform reasonably well for moderate sample sizes. Finally, we apply our method to data from a gel electrophoresis experiment with genetically engineered neuronal receptor subunits incubated with rat brain extract

  6. Selective feeding by coral reef fishes on coral lesions associated with brown band and black band disease

    Science.gov (United States)

    Chong-Seng, K. M.; Cole, A. J.; Pratchett, M. S.; Willis, B. L.

    2011-06-01

    Recent studies have suggested that corallivorous fishes may be vectors for coral disease, but the extent to which fishes actually feed on and thereby potentially transmit coral pathogens is largely unknown. For this study, in situ video observations were used to assess the level to which fishes fed on diseased coral tissues at Lizard Island, northern Great Barrier Reef. Surveys conducted at multiple locations around Lizard Island revealed that coral disease prevalence, especially of brown band disease (BrB), was higher in lagoon and backreef locations than in exposed reef crests. Accordingly, video cameras were deployed in lagoon and backreef habitats to record feeding by fishes during 1-h periods on diseased sections of each of 44 different coral colonies. Twenty-five species from five fish families (Blennidae, Chaetodontidae, Gobiidae, Labridae and Pomacentridae) were observed to feed on infected coral tissues of staghorn species of Acropora that were naturally infected with black band disease (BBD) or brown band disease (BrB). Collectively, these fishes took an average of 18.6 (±5.6 SE) and 14.3 (±6.1 SE) bites per hour from BBD and BrB lesions, respectively. More than 40% (408/948 bites) and nearly 25% (314/1319 bites) of bites were observed on lesions associated with BBD and BrB, respectively, despite these bands each representing only about 1% of the substratum available. Moreover, many corallivorous fishes ( Labrichthys unilineatus, Chaetodon aureofasciatus, C. baronessa, C. lunulatus, C. trifascialis, Cheiloprion labiatus) selectively targeted disease lesions over adjacent healthy coral tissues. These findings highlight the important role that reef fishes may play in the dynamics of coral diseases, either as vectors for the spread of coral disease or in reducing coral disease progression through intensive and selective consumption of diseased coral tissues.

  7. A compact dual band MIMO PIFA for 5G applications

    Science.gov (United States)

    Rachakonda, A.; Bang, P.; Mudiganti, J.

    2017-11-01

    5G applications support operations in 28, 37, 60 and 73GHz bands and is expected to support 1GHz bandwidth. In the present paper, planar inverted F antenna for 28GHz operation has been proposed for 5G applications for which a return loss of -17.46dB and a gain of 9.30dB have been observed. In addition, the design has been extended for dual band operation at 28 and 37GHz by implementing an L slot in the patch. An excellent return loss of -32.54dB and -18.57dB with a gain of 8.62dB has been observed. Moreover, a feasible bandwidth of 1.02GHz has been obtained in former design, while an enhanced bandwidth of 1.3GHz has been obtained at both bands in case of latter design. However, for better gain & data rate considerations, the previous design has been extended as a MIMO configuration with 2 antenna elements (2x1) and corresponding performance parameters have been evaluated.

  8. Closure of large wounds using rubber bands in rabbits

    Directory of Open Access Journals (Sweden)

    Maria Angélica Baron Magalhães

    Full Text Available OBJECTIVE: to verify the effectiveness of the rubber elastic band in the treatment of large wounds of the body wall of rabbits by means of traction of its edges. METHODS: we studied 30 New Zealand rabbits, divided into three groups (n=10: Group 1- healing by secondary intention; Group 2- removal and eutopic repositioning of skin as full thickness skin graft; Group 3- Approximation of wound edges with elastic rubber band. In all animals, we removed a segment of the back skin and subcutaneous tissue down to the fascia, in accordance with an acrylic mold of 8cm long by 12cm wide. All animals were observed for 21 days. RESULTS: two animals of groups 1 and 2 had wound abscess. In Group 2, there was partial or total graft loss in 90% of animals. The complete closure of the wounds was observed in four animals of Group 1, six of Group 2 and eight of Group 3. There was no difference between the scar resistance values of groups 2 and 3, which were higher than those in Group 1. The scars of the three groups were characterized by the presence of mature connective tissue mixed with blood vessels and inflammatory infiltration, predominantly polymorphonuclear. CONCLUSION: the tensile strength of the wound edges with rubber elastic band is as efficient as the skin graft to treat rabbits' large body wounds.

  9. Collective dipole rotational bands in the A {approx} 200 region

    Energy Technology Data Exchange (ETDEWEB)

    Clark, R M; Wadsworth, R; Regan, P H [York Univ. (United Kingdom). Dept. of Physics; Paul, E S; Beausang, C W; Ali, I; Cullen, D M; Dagnall, P J; Fallon, P; Joyce, M J; Sharpey-Schafer, J F [Liverpool Univ. (United Kingdom). Oliver Lodge Lab.; Astier, A; Meyer, M; Redon, N [Lyon-1 Univ., 69 - Villeurbanne (France). Inst. de Physique Nucleaire; Nazakewicz, W; Wyss, R [Joint Inst. for Heavy Ion Research, Oak Ridge, TN (United States)

    1992-08-01

    Rotational oblate bands consisting of regular sequences of magnetic dipole transitions have recently been identified in {sup 196-200}Pb. Their observation indicates a drastic change in the high-spin configurations between the Hg, Tl and {sup 194}Pb nuclei, in which SD bands are clearly observed, and the heavier Pb isotopes, where these weakly deformed oblate structures see to dominate. Angular correlation ratios show the transitions to be dipoles. Their magnetic nature can be deduced from intensity measurements, and they are characterized by small dynamic moments of inertia. Several of the bands have been interpreted as being built on high-K two-proton configurations coupled to an aligned pair of i{sub 13/2} neutrons in the even A nuclei, and to either one or three i{sub 13/2} neutrons in the odd A nuclei. Cranked shell model calculations predict the alignment of a pair of i{sub 13/2} neutrons (the AB crossing) at {omega} {approx} 0.18 MeV{Dirac_h}{sub -1}. The higher frequency crossing at {omega} {approx} 0.4 MeV{Dirac_h}{sub -1} may be due to the alignment of f{sub 5/2} neutrons, h{sub 11/2} protons, or both. 17 refs., 4 figs.

  10. Control Banding and Nanotechnology Synergist

    Energy Technology Data Exchange (ETDEWEB)

    Zalk, D; Paik, S

    2009-12-15

    The average Industrial Hygienist (IH) loves a challenge, right? Okay, well here is one with more than a few twists. We start by going through the basics of a risk assessment. You have some chemical agents, a few workers, and the makings of your basic exposure characterization. However, you have no occupational exposure limit (OEL), essentially no toxicological basis, and no epidemiology. Now the real handicap is that you cannot use sampling pumps, cassettes, tubes, or any of the media in your toolbox, and the whole concept of mass-to-dose is out the window, even at high exposure levels. Of course, by the title, you knew we were talking about nanomaterials (NM). However, we wonder how many IHs know that this topic takes everything you know about your profession and turns it upside down. It takes the very foundations that you worked so hard in college and in the field to master and pulls it out from underneath you. It even takes the gold standard of our profession, the quantitative science of exposure assessment, and makes it look pretty darn rusty. Now with NM there is the potential to get some aspect of quantitative measurements, but the instruments are generally very expensive and getting an appropriate workplace personal exposure measurement can be very difficult if not impossible. The potential for workers getting exposures, however, is very real, as evidenced by a recent publication reporting worker exposures to polyacrylate nanoparticles in a Chinese factory (Song et al. 2009). With something this complex and challenging, how does a concept as simple as Control Banding (CB) save the day? Although many IHs have heard of CB, most of their knowledge comes from its application in the COSHH Essentials toolkit. While there is conflicting published research on COSHH Essentials and its value for risk assessments, almost all of the experts agree that it can be useful when no OELs are available (Zalk and Nelson 2008). It is this aspect of CB, its utility with

  11. A case study on large-scale dynamical influence on bright band using cloud radar during the Indian summer monsoon

    Science.gov (United States)

    Jha, Ambuj K.; Kalapureddy, M. C. R.; Devisetty, Hari Krishna; Deshpande, Sachin M.; Pandithurai, G.

    2018-02-01

    The present study is a first of its kind attempt in exploring the physical features (e.g., height, width, intensity, duration) of tropical Indian bright band using a Ka-band cloud radar under the influence of large-scale cyclonic circulation and attempts to explain the abrupt changes in bright band features, viz., rise in the bright band height by 430 m and deepening of the bright band by about 300 m observed at around 14:00 UTC on Sep 14, 2016, synoptically as well as locally. The study extends the utility of cloud radar to understand how the bright band features are associated with light precipitation, ranging from 0 to 1.5 mm/h. Our analysis of the precipitation event of Sep 14-15, 2016 shows that the bright band above (below) 3.7 km, thickness less (more) than 300 m can potentially lead to light drizzle of 0-0.25 mm/h (drizzle/light rain) at the surface. It is also seen that the cloud radar may be suitable for bright band study within light drizzle limits than under higher rain conditions. Further, the study illustrates that the bright band features can be determined using the polarimetric capability of the cloud radar. It is shown that an LDR value of - 22 dB can be associated with the top height of bright band in the Ka-band observations which is useful in the extraction of the bright band top height and its width. This study is useful for understanding the bright band phenomenon and could be potentially useful in establishing the bright band-surface rain relationship through the perspective of a cloud radar, which would be helpful to enhance the cloud radar-based quantitative estimates of precipitation.

  12. Modification in band gap of zirconium complexes

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Mayank, E-mail: mayank30134@gmail.com; Singh, J.; Chouhan, S. [Department of Physics, ISLE, IPS Academy, Indore (M.P.) (India); Mishra, A. [School of Physics, Devi Ahilya Vishwavidyalaya, Indore (M.P.) (India); Shrivastava, B. D. [Govt. P. G. College, Biora (M.P.) (India)

    2016-05-06

    The optical properties of zirconium complexes with amino acid based Schiff bases are reported here. The zirconium complexes show interesting stereo chemical features, which are applicable in organometallic and organic synthesis as well as in catalysis. The band gaps of both Schiff bases and zirconium complexes were obtained by UV-Visible spectroscopy. It was found that the band gap of zirconium complexes has been modified after adding zirconium compound to the Schiff bases.

  13. Theoretical Prediction of the Forming Limit Band

    International Nuclear Information System (INIS)

    Banabic, D.; Paraianu, L.; Vos, M.; Jurco, P.

    2007-01-01

    Forming Limit Band (FLB) is a very useful tool to improve the sheet metal forming simulation robustness. Until now, the study of the FLB was only experimental. This paper presents the first attempt to model the FLB. The authors have established an original method for predicting the two margins of the limit band. The method was illustrated on the AA6111-T43 aluminum alloy. A good agreement with the experiments has been obtained

  14. Theoretical Prediction of the Forming Limit Band

    Science.gov (United States)

    Banabic, D.; Vos, M.; Paraianu, L.; Jurco, P.

    2007-04-01

    Forming Limit Band (FLB) is a very useful tool to improve the sheet metal forming simulation robustness. Until now, the study of the FLB was only experimental. This paper presents the first attempt to model the FLB. The authors have established an original method for predicting the two margins of the limit band. The method was illustrated on the AA6111-T43 aluminum alloy. A good agreement with the experiments has been obtained.

  15. Home-use cancer detecting band aid

    Science.gov (United States)

    Zalevsky, Zeev; Rudnitsky, Arkady; Sheinman, Victor; Tzoy, Andrey; Toktosunov, Aitmamat; Adashov, Arkady

    2016-03-01

    In this paper we present a novel concept in which special band aid is developed for early detection of cancer. The band aid contains an array of micro needles with small detection array connected to each needle which inspects the color of the surface of the skin versus time after being pinched with the needles. We were able to show in pre-clinical trials that the color varies differently if the skin is close to tumor tissue.

  16. Deformation bands in ceria-stabilized tetragonal zirconia/alumina. 2: Stress-induced aging at room temperature

    International Nuclear Information System (INIS)

    Sergo, V.; Clarke, D.R.

    1995-01-01

    A stress-induced aging phenomenon is observed to occur at room temperature in deformation bands introduced into a 8.5 mol% ceria-stabilized tetragonal zirconia/alumina (Ce-TZP/Al 2 O 3 ) composite by flexural loading. The aging occurs with time after unloading and in laboratory air. Over a period of 100 days, the concentration of monoclinic zirconia within a deformation band increases and, in addition, the wedge-shaped deformation band grows with time. Accompanying these two changes are an increase in the tensile stress in the remaining tetragonal zirconia within the deformation band and a consequential increase in the overall compressive stress within the band. The average value of the monoclinic concentration within the deformation band is found to increase parabolically with time, suggesting the mechanism responsible for the observed aging is diffusion limited. Away from the deformation bands, no aging is observed to occur, suggesting aging is stress dependent. Although a water-vapor-mediated mechanism cannot be ruled out, it is proposed that the observed aging is in fact due to a tensile stress assisted chemical reduction of Ce 4+ to Ce 3+ whose rate is controlled by the indiffusion of oxygen vacancies driven by the tensile stress gradient. It is further proposed that the deformation band grows with time the region ahead of the band is under tension a subject to an enhanced rate of reduction

  17. Radar observations of Mercury

    International Nuclear Information System (INIS)

    Harmon, J.K.; Campbell, D.B.

    1988-01-01

    Some of the radar altimetry profiles of Mercury obtained on the basis of data from the Arecibo Observatory are presented. In these measurements, the delay-Doppler method was used to measure altitudes along the Doppler equator, rather than to map radar reflectivity. The profiles, derived from observations made over a 6-yr period, provide extensive coverage over a restricted equatorial band and permit the identification of radar signatures for features as small as 50-km diameter craters and 1-km-high arcuate scarps. The data allowed identification of large-scale topographic features such as smooth plains subsidence zones and major highland regions

  18. Band structures in near spherical 138Ce

    Science.gov (United States)

    Bhattacharjee, T.; Chanda, S.; Bhattacharyya, S.; Basu, S. K.; Bhowmik, R. K.; Das, J. J.; Pramanik, U. Datta; Ghugre, S. S.; Madhavan, N.; Mukherjee, A.; Mukherjee, G.; Muralithar, S.; Singh, R. P.

    2009-06-01

    The high spin states of N=80138Ce have been populated in the fusion evaporation reaction 130Te( 12C, 4n) 138Ce at E=65 MeV. The γ transitions belonging to various band structures were detected and characterized using an array of five Clover Germanium detectors. The level scheme has been established up to a maximum spin and excitation energy of 23 ℏ and 9511.3 keV, respectively, by including 53 new transitions. The negative parity ΔI=1 band, developed on the 6536.3 keV 15 level, has been conjectured to be a magnetic rotation band following a semiclassical analysis and comparing the systematics of similar bands in the neighboring nuclei. The said band is proposed to have a four quasiparticle configuration of [πgh]⊗[. Other band structures are interpreted in terms of multi-quasiparticle configurations, based on Total Routhian Surface (TRS) calculations. For the low and medium spin states, a shell model calculation using a realistic two body interaction has been performed using the code OXBASH.

  19. Electron correlations in narrow band systems

    International Nuclear Information System (INIS)

    Kishore, R.

    1983-01-01

    The effect of the electron correlations in narrow bands, such as d(f) bands in the transition (rare earth) metals and their compounds and the impurity bands in doped semiconductors is studied. The narrow band systems is described, by the Hubbard Hamiltonian. By proposing a local self-energy for the interacting electron, it is found that the results are exact in both atomic and band limits and reduce to the Hartree Fock results for U/Δ → 0, where U is the intra-atomic Coulomb interaction and Δ is the bandwidth of the noninteracting electrons. For the Lorentzian form of the density of states of the noninteracting electrons, this approximation turns out to be equivalent to the third Hubbard approximation. A simple argument, based on the mean free path obtained from the imaginary part of the self energy, shows how the electron correlations can give rise to a discontinous metal-nonmetal transition as proposed by Mott. The band narrowing and the existence of the satellite below the Fermi energy in Ni, found in photoemission experiments, can also be understood. (Author) [pt

  20. Band termination in the N=Z nucleus 44Ti

    International Nuclear Information System (INIS)

    Ur, C.A.; Lenzi, S.M.; Martinez-Pinedo, G.

    1998-01-01

    Nuclei in the vicinity of the middle of the 1f 7/2 shell show strong prolate deformation at low spins resulting in rotational-like band structures. With increasing angular momentum the structure of these nuclei evolves through triaxial and spherical shapes. Recently, band terminating states corresponding to fully aligned configurations of valence nucleons in the f 7/2 shell have been reported. Further increase of the angular momentum can be achieved by particle excitations on the higher shell. This will result in high energy γ-ray transitions as it was observed in 50 Cr. We have investigated the structure of 44 Ti up to the band termination. Excited states in 44 Ti have been populated via the 28 Si + 24 Mg at 110 MeV beam energy. The target consisted of ∼0.5 mg/cm 2 of 24 Mg deposited on a gold backing. Gamma-rays were detected with the GASP multidetector array composed by 40 HPGe Compton-suppressed detectors and the inner ball built of 80 BGO detectors. The preliminary level scheme of 44 Ti, as determined in our work, is presented. This nucleus has 2 valence protons and 2 valence neutrons filling the f 7/2 shell. The band terminating state corresponding to their total alignment is the 12 + state. Several γ-rays transitions above this state have been identified. Also, we have identified two negative parity bands strongly connected to the yrast positive parity structure. Such structures have also been observed in other two even-even N=Z nuclei in the f 7/2 shell, namely, 44 Cr and 52 Fe, but they were less populated. The structure of 44 Ti is also interesting from the point of view of the cross-conjugate symmetry. Comparing the level structure of 44 Ti and the one of its cross-conjugate nucleus at the other end of the shell, 52 Fe, it can be noticed that up to spin 10ℎ their structure is very similar, but in 44 Ti the band terminating state 12 + is not below the 10 + state as in the case of 52 Fe. This was related to a reminiscent degree of collectivity in the

  1. Entrance-channel effects in the population of superdeformed bands

    Energy Technology Data Exchange (ETDEWEB)

    Smith, G.; Haas, B.; Alderson, A.; Ali, I.; Beausang, C.W.; Bentley, M.A.; Dagnall, P.; Fallon, P.; de France, G.; Forsyth, P.D.; Huttmeier, U.; Romain, P.; Santos, D.; Twin, P.J.; Vivien, J.P. (Oliver Lodge Laboratory, University of Liverpool, Liverpool L69 3BX (United Kingdom) Centre de Recherches Nucleaires, F-67037 Strasbourg CEDEX (France) Sciences and Engineering Research Council, Daresbury Laboratory, Warrington WA44AD (United Kingdom))

    1992-01-13

    In order to investigate whether entrance-channel effects influence the production of superdeformed nuclei, we have measured the yield of the yrast superdeformed band in {sup 152}Dy populated via nearly mass-symmetric ({sup 82}Se+{sup 74}Ge) and mass-asymmetric ({sup 48}Ca+{sup 108}Pd, {sup 36}S+{sup 120}Sn) fusion reactions leading to the same compound nucleus at similar excitation energies and angular momenta. Large differences in the relative intensity of the band compared with the total yield of the nucleus are observed in the various reactions. This effect indicates that the competition between fission and neutron evaporation is affected by the mode of formation of the fusing system.

  2. Assignment of Nilsson orbitals at superdeformation - identical bands

    Energy Technology Data Exchange (ETDEWEB)

    Ragnarsson, I [Lund Univ. (Sweden). Dept. of Mathematical Physics

    1992-08-01

    The relative transition energies of superdeformed rotational bands are used to extract ``effective alignments`` of the valence particles. It is found that the effective alignments give a direct picture of the Nilsson orbitals which are active in {sup 146-150}Gd, i.e., especially the orbitals [651 1/2] and [642 5/2], and that all bands observed in these nuclei can be understood within one consistent scheme. The experimental features are reproduced in calculations using the Nilsson-Strutinsky cranking model. The nearly identical transition energies seen in neighboring odd-proton and even-proton nuclei in the Dy/Tb/Gd region are investigated using the same formalism. Again, a consistent picture seems to emerge where, as suggested previously, the nucleus with a hole in the [301 1/2] Nilsson orbital and the corresponding core nucleus have calculated transition energies which are almost identical over a large range in spin. 2 refs., figs.

  3. Microstructural evolution of a model, shear-banding micellar solution during shear startup and cessation.

    Science.gov (United States)

    López-Barrón, Carlos R; Gurnon, A Kate; Eberle, Aaron P R; Porcar, Lionel; Wagner, Norman J

    2014-04-01

    We present direct measurements of the evolution of the segmental-level microstructure of a stable shear-banding polymerlike micelle solution during flow startup and cessation in the plane of flow. These measurements provide a definitive, quantitative microstructural understanding of the stages observed during flow startup: an initial elastic response with limited alignment that yields with a large stress overshoot to a homogeneous flow with associated micellar alignment that persists for approximately three relaxation times. This transient is followed by a shear (kink) band formation with a flow-aligned low-viscosity band that exhibits shear-induced concentration fluctuations and coexists with a nearly isotropic band of homogenous, highly viscoelastic micellar solution. Stable, steady banding flow is achieved only after approximately two reptation times. Flow cessation from this shear-banded state is also found to be nontrivial, exhibiting an initial fast relaxation with only minor structural relaxation, followed by a slower relaxation of the aligned micellar fluid with the equilibrium fluid's characteristic relaxation time. These measurements resolve a controversy in the literature surrounding the mechanism of shear banding in entangled wormlike micelles and, by means of comparison to existing literature, provide further insights into the mechanisms driving shear-banding instabilities in related systems. The methods and instrumentation described should find broad use in exploring complex fluid rheology and testing microstructure-based constitutive equations.

  4. Metal-like Band Structures of Ultrathin Si {111} and {112} Surface Layers Revealed through Density Functional Theory Calculations.

    Science.gov (United States)

    Tan, Chih-Shan; Huang, Michael H

    2017-09-04

    Density functional theory calculations have been performed on Si (100), (110), (111), and (112) planes with tunable number of planes for evaluation of their band structures and density of states profiles. The purpose is to see whether silicon can exhibit facet-dependent properties derived from the presence of a thin surface layer having different band structures. No changes have been observed for single to multiple layers of Si (100) and (110) planes with a consistent band gap between the valence band and the conduction band. However, for 1, 2, 4, and 5 Si (111) and (112) planes, metal-like band structures were obtained with continuous density of states going from the valence band to the conduction band. For 3, 6, and more Si (111) planes, as well as 3 and 6 Si (112) planes, the same band structure as that seen for Si (100) and (110) planes has been obtained. Thus, beyond a layer thickness of five Si (111) planes at ≈1.6 nm, normal semiconductor behavior can be expected. The emergence of metal-like band structures for the Si (111) and (112) planes are related to variation in Si-Si bond length and bond distortion plus 3s and 3p orbital electron contributions in the band structure. This work predicts possession of facet-dependent electrical properties of silicon with consequences in FinFET transistor design. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Clamped seismic metamaterials: ultra-low frequency stop bands

    International Nuclear Information System (INIS)

    Achaoui, Y; Enoch, S; Guenneau, S; Antonakakis, T; Brûlé, S; Craster, R V

    2017-01-01

    The regularity of earthquakes, their destructive power, and the nuisance of ground vibration in urban environments, all motivate designs of defence structures to lessen the impact of seismic and ground vibration waves on buildings. Low frequency waves, in the range 1–10 Hz for earthquakes and up to a few tens of Hz for vibrations generated by human activities, cause a large amount of damage, or inconvenience; depending on the geological conditions they can travel considerable distances and may match the resonant fundamental frequency of buildings. The ultimate aim of any seismic metamaterial, or any other seismic shield, is to protect over this entire range of frequencies; the long wavelengths involved, and low frequency, have meant this has been unachievable to date. Notably this is scalable and the effects also hold for smaller devices in ultrasonics. There are three approaches to obtaining shielding effects: bragg scattering, locally resonant sub-wavelength inclusions and zero-frequency stop-band media. The former two have been explored, but the latter has not and is examined here. Elastic flexural waves, applicable in the mechanical vibrations of thin elastic plates, can be designed to have a broad zero-frequency stop-band using a periodic array of very small clamped circles. Inspired by this experimental and theoretical observation, all be it in a situation far removed from seismic waves, we demonstrate that it is possible to achieve elastic surface (Rayleigh) wave reflectors at very large wavelengths in structured soils modelled as a fully elastic layer periodically clamped to bedrock. We identify zero frequency stop-bands that only exist in the limit of columns of concrete clamped at their base to the bedrock. In a realistic configuration of a sedimentary basin 15 m deep we observe a zero frequency stop-band covering a broad frequency range of 0–30 Hz. (paper)

  6. Snow bands over the Gulf of Finland in wintertime

    Directory of Open Access Journals (Sweden)

    Jordi Mazon

    2015-01-01

    Full Text Available Large shore-parallel, quasi-stationary snow bands are occasionally observed over the Gulf of Finland during wintertime when the sea is not frozen. On the basis of Weather Research and Forecasting mesoscale model experiments and radar observations of snow bands formed in January 2006 and February 2012, we show that their dynamics share common characteristics: (1 the sea gulf that produces the known lake effect, (2 cold easterly large-scale flow along the gulf and (3 a cold local flow from the two near and opposite coastlines of Estonia and Finland in the form of two land-breeze cells which collide offshore. The associated fronts, which have strong rising motions, are maintained by the convergence of the land-breeze cells. In addition to these factors, the concave shape of the coast in the eastern part of the Gulf of Finland promotes offshore convergence and the formation of several secondary bands of precipitation that are adjacent to the eastern part of the main band. When the easterlies turn to southerlies, horizontal convective rolls appear over the sea. The Estonian land breeze is enhanced while the cold air remains stagnant inland over the Finnish coast, acting as an orographic barrier lifting the marine air mass upwards. Consequently, a line of convective precipitation composed of several cells is formed along the Finnish coast. In both events, the simulations also show two low-level jets generated by the combined effects of the land-breeze cells and baroclinicity over the coast of Finland and Estonia.

  7. B(M1) values in the band-crossing of shears bands in 197Pb

    Science.gov (United States)

    Krücken, R.; Cooper, J. R.; Beausang, C. W.; Novak, J. R.; Dewald, A.; Klug, T.; Kemper, G.; von Brentano, P.; Carpenter, M.; Wiedenhöver, I.

    We present details of the band crossing mechanism of shears bands using the example of 197Pb. Absolute reduced matrix elements B(M1) were determined by means of a RDM lifetime measurement in one of the shears bands in 197Pb. The experiment was performed using the New Yale Plunger Device (NYPD) in conjunction with the Gammasphere array. Band mixing calculations on the basis of the semi-classical model of the shears mechanism are used to describe the transition matrix elements B(M1) and energies throughout the band-crossing regions. Good agreement with the data was obtained and the detailed composition of the states in the shears band are discussed.

  8. ISM band to U-NII band frequency transverter and method of frequency transversion

    Science.gov (United States)

    Stepp, Jeffrey David [Grandview, MO; Hensley, Dale [Grandview, MO

    2006-09-12

    A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz 6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

  9. Revisiting Short-Wave-Infrared (SWIR) Bands for Atmospheric Correction in Coastal Waters

    Science.gov (United States)

    Pahlevan, Nima; Roger, Jean-Claude; Ahmad, Ziauddin

    2017-01-01

    The shortwave infrared (SWIR) bands on the existing Earth Observing missions like MODIS have been designed to meet land and atmospheric science requirements. The future geostationary and polar-orbiting ocean color missions, however, require highly sensitive SWIR bands (greater than 1550nm) to allow for a precise removal of aerosol contributions. This will allow for reasonable retrievals of the remote sensing reflectance (R(sub rs)) using standard NASA atmospheric corrections over turbid coastal waters. Design, fabrication, and maintaining high-performance SWIR bands at very low signal levels bear significant costs on dedicated ocean color missions. This study aims at providing a full analysis of the utility of alternative SWIR bands within the 1600nm atmospheric window if the bands within the 2200nm window were to be excluded due to engineering/cost constraints. Following a series of sensitivity analyses for various spectral band configurations as a function of water vapor amount, we chose spectral bands centered at 1565 and 1675nm as suitable alternative bands within the 1600nm window for a future geostationary imager. The sensitivity of this band combination to different aerosol conditions, calibration uncertainties, and extreme water turbidity were studied and compared with that of all band combinations available on existing polar-orbiting missions. The combination of the alternative channels was shown to be as sensitive to test aerosol models as existing near-infrared (NIR) band combinations (e.g., 748 and 869nm) over clear open ocean waters. It was further demonstrated that while in extremely turbid waters the 1565/1675 band pair yields R(sub rs) retrievals as good as those derived from all other existing SWIR band pairs (greater than 1550nm), their total calibration uncertainties must be less than 1% to meet current science requirements for ocean color retrievals (i.e., delta R(sub rs) (443) less than 5%). We further show that the aerosol removal using the

  10. Properties of rotational bands at the spin limit in A {approximately} 50, A {approximately} 65 and A {approximately} 110 nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Janzen, V.P.; Andrews, H.R.; Ball, G.C. [Chalk River Labs., Ontario (Canada)] [and others

    1996-12-31

    There is now widespread evidence for the smooth termination of rotational bands in A {approx_equal} 110 nuclei at spins of 40-to-50{Dirac_h}s. The characteristics of these bands are compared to those of bands recently observed to high spin in {sup 64}Zn and {sup 48}Cr, studied with the 8{pi} {gamma}-ray spectrometer coupled to the Chalk River miniball charged-particle-detector array.

  11. Optic nerve compression as a late complication of a hydrogel explant with silicone encircling band

    Directory of Open Access Journals (Sweden)

    Niels Crama

    2018-06-01

    Full Text Available Purpose: To present a complication of compressive optic neuropathy caused by a swollen hydrogel explant and posteriorly displaced silicone encircling band. Observations: A 72-year-old female patient presented with progressive visual loss and a tilted optic disc. Her medical history included a retinal detachment in 1993 that was treated with a hydrogel explant under a solid silicone encircling band. Visual acuity had decreased from 6/10 to 6/20 and perimetry showed a scotoma in the temporal superior quadrant. On Magnetic Resonance Imaging (MRI, compression of the optic nerve by a displaced silicone encircling band inferior nasally in combination with a swollen episcleral hydrogel explant was observed. Surgical removal of the hydrogel explant and silicone encircling band was uneventful and resulted in improvement of visual acuity and visual field loss. Conclusions and importance: This is the first report on compressive optic neuropathy caused by swelling of a hydrogel explant resulting in a dislocated silicone encircling band. The loss of visual function resolved upon removal of the explant and encircling band. Keywords: Retinal detachment, Tilted disc, Optic neuropathy, Miragel, Explant, Encircling band

  12. Evidence of ion intercalation mediated band structure modification and opto-ionic coupling in lithium niobite

    Science.gov (United States)

    Shank, Joshua C.; Tellekamp, M. Brooks; Doolittle, W. Alan

    2015-01-01

    The theoretically suggested band structure of the novel p-type semiconductor lithium niobite (LiNbO2), the direct coupling of photons to ion motion, and optically induced band structure modifications are investigated by temperature dependent photoluminescence. LiNbO2 has previously been used as a memristor material but is shown here to be useful as a sensor owing to the electrical, optical, and chemical ease of lithium removal and insertion. Despite the high concentration of vacancies present in lithium niobite due to the intentional removal of lithium atoms, strong photoluminescence spectra are observed even at room temperature that experimentally confirm the suggested band structure implying transitions from a flat conduction band to a degenerate valence band. Removal of small amounts of lithium significantly modifies the photoluminescence spectra including additional larger than stoichiometric-band gap features. Sufficient removal of lithium results in the elimination of the photoluminescence response supporting the predicted transition from a direct to indirect band gap semiconductor. In addition, non-thermal coupling between the incident laser and lithium ions is observed and results in modulation of the electrical impedance.

  13. Evidence of ion intercalation mediated band structure modification and opto-ionic coupling in lithium niobite

    Energy Technology Data Exchange (ETDEWEB)

    Shank, Joshua C.; Tellekamp, M. Brooks; Doolittle, W. Alan, E-mail: alan.doolittle@ece.gatech.edu [Department of Electrical and Computer Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)

    2015-01-21

    The theoretically suggested band structure of the novel p-type semiconductor lithium niobite (LiNbO{sub 2}), the direct coupling of photons to ion motion, and optically induced band structure modifications are investigated by temperature dependent photoluminescence. LiNbO{sub 2} has previously been used as a memristor material but is shown here to be useful as a sensor owing to the electrical, optical, and chemical ease of lithium removal and insertion. Despite the high concentration of vacancies present in lithium niobite due to the intentional removal of lithium atoms, strong photoluminescence spectra are observed even at room temperature that experimentally confirm the suggested band structure implying transitions from a flat conduction band to a degenerate valence band. Removal of small amounts of lithium significantly modifies the photoluminescence spectra including additional larger than stoichiometric-band gap features. Sufficient removal of lithium results in the elimination of the photoluminescence response supporting the predicted transition from a direct to indirect band gap semiconductor. In addition, non-thermal coupling between the incident laser and lithium ions is observed and results in modulation of the electrical impedance.

  14. Evidence of ion intercalation mediated band structure modification and opto-ionic coupling in lithium niobite

    International Nuclear Information System (INIS)

    Shank, Joshua C.; Tellekamp, M. Brooks; Doolittle, W. Alan

    2015-01-01

    The theoretically suggested band structure of the novel p-type semiconductor lithium niobite (LiNbO 2 ), the direct coupling of photons to ion motion, and optically induced band structure modifications are investigated by temperature dependent photoluminescence. LiNbO 2 has previously been used as a memristor material but is shown here to be useful as a sensor owing to the electrical, optical, and chemical ease of lithium removal and insertion. Despite the high concentration of vacancies present in lithium niobite due to the intentional removal of lithium atoms, strong photoluminescence spectra are observed even at room temperature that experimentally confirm the suggested band structure implying transitions from a flat conduction band to a degenerate valence band. Removal of small amounts of lithium significantly modifies the photoluminescence spectra including additional larger than stoichiometric-band gap features. Sufficient removal of lithium results in the elimination of the photoluminescence response supporting the predicted transition from a direct to indirect band gap semiconductor. In addition, non-thermal coupling between the incident laser and lithium ions is observed and results in modulation of the electrical impedance

  15. RRI-GBT MULTI-BAND RECEIVER: MOTIVATION, DESIGN, AND DEVELOPMENT

    International Nuclear Information System (INIS)

    Maan, Yogesh; Deshpande, Avinash A.; Chandrashekar, Vinutha; Chennamangalam, Jayanth; Rao, K. B. Raghavendra; Somashekar, R.; Ezhilarasi, M. S.; Sujatha, S.; Kasturi, S.; Sandhya, P.; Duraichelvan, R.; Amiri, Shahram; Aswathappa, H. A.; Sarabagopalan, G.; Ananda, H. M.; Anderson, Gary; Bauserman, Jonah; Beaudet, Carla; Bloss, Marty; Barve, Indrajit V.

    2013-01-01

    We report the design and development of a self-contained multi-band receiver (MBR) system, intended for use with a single large aperture to facilitate sensitive and high time-resolution observations simultaneously in 10 discrete frequency bands sampling a wide spectral span (100-1500 MHz) in a nearly log-periodic fashion. The development of this system was primarily motivated by need for tomographic studies of pulsar polar emission regions. Although the system design is optimized for the primary goal, it is also suited for several other interesting astronomical investigations. The system consists of a dual-polarization multi-band feed (with discrete responses corresponding to the 10 bands pre-selected as relatively radio frequency interference free), a common wide-band radio frequency front-end, and independent back-end receiver chains for the 10 individual sub-bands. The raw voltage time sequences corresponding to 16 MHz bandwidth each for the two linear polarization channels and the 10 bands are recorded at the Nyquist rate simultaneously. We present the preliminary results from the tests and pulsar observations carried out with the Robert C. Byrd Green Bank Telescope using this receiver. The system performance implied by these results and possible improvements are also briefly discussed.

  16. RRI-GBT MULTI-BAND RECEIVER: MOTIVATION, DESIGN, AND DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    Maan, Yogesh; Deshpande, Avinash A.; Chandrashekar, Vinutha; Chennamangalam, Jayanth; Rao, K. B. Raghavendra; Somashekar, R.; Ezhilarasi, M. S.; Sujatha, S.; Kasturi, S.; Sandhya, P.; Duraichelvan, R.; Amiri, Shahram; Aswathappa, H. A.; Sarabagopalan, G.; Ananda, H. M. [Raman Research Institute, Bangalore (India); Anderson, Gary; Bauserman, Jonah; Beaudet, Carla; Bloss, Marty [National Radio Astronomy Observatory, P.O. Box 2, Green Bank, WV (United States); Barve, Indrajit V. [Indian Institute of Astrophysics, Bangalore (India); and others

    2013-01-15

    We report the design and development of a self-contained multi-band receiver (MBR) system, intended for use with a single large aperture to facilitate sensitive and high time-resolution observations simultaneously in 10 discrete frequency bands sampling a wide spectral span (100-1500 MHz) in a nearly log-periodic fashion. The development of this system was primarily motivated by need for tomographic studies of pulsar polar emission regions. Although the system design is optimized for the primary goal, it is also suited for several other interesting astronomical investigations. The system consists of a dual-polarization multi-band feed (with discrete responses corresponding to the 10 bands pre-selected as relatively radio frequency interference free), a common wide-band radio frequency front-end, and independent back-end receiver chains for the 10 individual sub-bands. The raw voltage time sequences corresponding to 16 MHz bandwidth each for the two linear polarization channels and the 10 bands are recorded at the Nyquist rate simultaneously. We present the preliminary results from the tests and pulsar observations carried out with the Robert C. Byrd Green Bank Telescope using this receiver. The system performance implied by these results and possible improvements are also briefly discussed.

  17. Madelung and Hubbard interactions in polaron band model of doped organic semiconductors

    Science.gov (United States)

    Png, Rui-Qi; Ang, Mervin C.Y.; Teo, Meng-How; Choo, Kim-Kian; Tang, Cindy Guanyu; Belaineh, Dagmawi; Chua, Lay-Lay; Ho, Peter K.H.

    2016-01-01

    The standard polaron band model of doped organic semiconductors predicts that density-of-states shift into the π–π* gap to give a partially filled polaron band that pins the Fermi level. This picture neglects both Madelung and Hubbard interactions. Here we show using ultrahigh workfunction hole-doped model triarylamine–fluorene copolymers that Hubbard interaction strongly splits the singly-occupied molecular orbital from its empty counterpart, while Madelung (Coulomb) interactions with counter-anions and other carriers markedly shift energies of the frontier orbitals. These interactions lower the singly-occupied molecular orbital band below the valence band edge and give rise to an empty low-lying counterpart band. The Fermi level, and hence workfunction, is determined by conjunction of the bottom edge of this empty band and the top edge of the valence band. Calculations are consistent with the observed Fermi-level downshift with counter-anion size and the observed dependence of workfunction on doping level in the strongly doped regime. PMID:27582355

  18. Attenuation and velocity dispersion in the exploration seismic frequency band

    Science.gov (United States)

    Sun, Langqiu

    In an anelastic medium, seismic waves are distorted by attenuation and velocity dispersion, which depend on petrophysical properties of reservoir rocks. The effective attenuation and velocity dispersion is a combination of intrinsic attenuation and apparent attenuation due to scattering, transmission response, and data acquisition system. Velocity dispersion is usually neglected in seismic data processing partly because of insufficient observations in the exploration seismic frequency band. This thesis investigates the methods of measuring velocity dispersion in the exploration seismic frequency band and interprets the velocity dispersion data in terms of petrophysical properties. Broadband, uncorrelated vibrator data are suitable for measuring velocity dispersion in the exploration seismic frequency band, and a broad bandwidth optimizes the observability of velocity dispersion. Four methods of measuring velocity dispersion in uncorrelated vibrator VSP data are investigated, which are the sliding window crosscorrelation (SWCC) method, the instantaneous phase method, the spectral decomposition method, and the cross spectrum method. Among them, the SWCC method is a new method and has satisfactory robustness, accuracy, and efficiency. Using the SWCC method, velocity dispersion is measured in the uncorrelated vibrator VSP data from three areas with different geological settings, i.e., Mallik gas hydrate zone, McArthur River uranium mines, and Outokumpu crystalline rocks. The observed velocity dispersion is fitted to a straight line with respect to log frequency for a constant (frequency-independent) Q value. This provides an alternative method for calculating Q. A constant Q value does not directly link to petrophysical properties. A modeling study is implemented for the Mallik and McArthur River data to interpret the velocity dispersion observations in terms of petrophysical properties. The detailed multi-parameter petrophysical reservoir models are built according to

  19. The Fermi surface and band folding in La{sub 2-x}Sr{sub x}CuO{sub 4}, probed by angle-resolved photoemission

    Energy Technology Data Exchange (ETDEWEB)

    Razzoli, E; Radovic, M; Patthey, L; Shi, M [Swiss Light Source, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Sassa, Y; Chang, J [Laboratory for Neutron Scattering, Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Drachuck, G; Keren, A; Shay, M [Department of Physics, Technion-Israel Institute of Technology, Haifa 32000 (Israel); Maansson, M; Mesot, J [Laboratory for Synchrotron and Neutron Spectroscopy, EPF Lausanne, CH-1015 Lausanne (Switzerland); Berntsen, M H; Tjernberg, O [Materials Physics, KTH Royal Institute of Technology, S-16440 Kista (Sweden); Pailhes, S [CEA, CNRS, CE Saclay, Laboratoire Leon Brillouin, F-91191 Gif Sur Yvette (France); Momono, N [Department of Applied Sciences, Muroran Institute of Technology, Muroran 050-8585 (Japan); Oda, M; Ido, M [Department of Physics, Hokkaido University, Sapporo 060-0810 (Japan); Lipscombe, O J; Hayden, S M, E-mail: ming.shi@psi.c [H H Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom)

    2010-12-15

    A systematic angle-resolved photoemission study of the electronic structure of La{sub 2-x}Sr{sub x}CuO{sub 4} in a wide doping range is presented in this paper. In addition to the main energy band, we observed a weaker additional band, the ({pi}, {pi}) folded band, which shows unusual doping dependence. The appearance of the folded band suggests that a Fermi surface reconstruction is doping dependent and could already occur at zero magnetic field.

  20. Test of Neural Network Techniques using Simulated Dual-Band Data of LEO Satellites

    Science.gov (United States)

    2010-09-01

    component to allow for glinting surfaces, such as solar panels. Radiant intensities are calculated for a blue band (468-495 nm) and a red band (738-765...When a satellite is visible for at least one of the observation sites, OSC is used to calculate radiant intensity in the blue and red spectral bands...Input node, aji , contains the ith value of radiant intensity for the jth pass of a satellite. In this work, the n input nodes are values of radiant

  1. Near-infrared emission bands of TeH and TeD

    Science.gov (United States)

    Fink, E. H.; Setzer, K. D.; Ramsay, D. A.; Vervloet, M.

    1989-11-01

    High-resolution emission spectra of TeH and TeD have been obtained in the region 4200 to 3600 cm -1 using a Bomem DA3.002 Fourier transform spectrometer. Analyses are given for the 0-0 and 1-1 bands of the X 22Π{1}/{2}-X 12Π{3}/{2} system of TeH and for the 0-0 band of TeD. In addition the 2-0 vibrational overtone bands of 130TeH, 128TeH, and 126TeH are observed and analyzed. Accurate molecular constants are given for the first time.

  2. Anomalous electrical resistivity and Hall constant of Anderson lattice with finite f-band width

    International Nuclear Information System (INIS)

    Panwar, Sunil; Singh, Ishwar

    2002-01-01

    We study here an extension of the periodic Anderson model by considering finite f-band width. A variational method is used to study the temperature dependence of electronic transport properties of Anderson lattice for different values of the f-band width. The electrical resistivity ρ(T) and Hall constant R H (T) calculated show qualitatively the features experimentally observed in heavy fermion materials. We find that as f-band width increases, the low temperature peak in ρ(T) disappears, while the low-temperature peak in R H (T) becomes sharper. (author)

  3. Study of III-V semiconductor band structure by synchrotron photoemission

    International Nuclear Information System (INIS)

    Williams, G.P.; Cerrina, F.; Anderson, J.; Lapeyre, G.J.; Smith, R.J.; Hermanson, J.; Knapp, J.A.

    1982-01-01

    Angle-resolved synchrotron photoemission studies of six III-V semiconductors have been carried out. For emission normal to the (110) plane of these materials, peaks in the experimental spectra were identified with the bands involved in the transitions, and the critical point energies X 3 , X 5 , and Σ 1 /sup min/, were determined. The data indicate that k perpendicular is conserved in the transitions. Comparison of the data with theoretical bands permits an evaluation of k perpendicular associated with the experimentally observed transition, and from this information the bands were plotted out

  4. A multitude of rotational bands in {sup 163}Er and their mutual interaction

    Energy Technology Data Exchange (ETDEWEB)

    Bosetti, P.; Leoni, S.; Bracco, A. [Univ. of Milan (Italy)] [and others

    1996-12-31

    Using the {sup 150}Nd({sup 18}O, 5n){sup 163}Er reaction a multitude of rotational bands have been established with firm spin and parity assignments in {sup 163}Er. In 16 out of {approximately} 23 band crossings E2 cross-band transitions have been observed. The interaction strength varies between {approximately} 1 and {approximately} 50 keV. These interactions sample a variety of the lowest (multi)-quasiparticle configurations. Some of the band configurations, in particular those with high K-values, can be rather well established. Quite complicated changes in the wavefunctions must occur at these crossings, and, to explain the observed interaction strengths, one may have to invoke coupling to various vibrational degrees of freedom, in addition to possible residual neutron-proton interactions.

  5. Ferritin associates with marginal band microtubules

    International Nuclear Information System (INIS)

    Infante, Anthony A.; Infante, Dzintra; Chan, M.-C.; How, P.-C.; Kutschera, Waltraud; Linhartova, Irena; Muellner, Ernst W.; Wiche, Gerhard; Propst, Friedrich

    2007-01-01

    We characterized chicken erythrocyte and human platelet ferritin by biochemical studies and immunofluorescence. Erythrocyte ferritin was found to be a homopolymer of H-ferritin subunits, resistant to proteinase K digestion, heat stable, and contained iron. In mature chicken erythrocytes and human platelets, ferritin was localized at the marginal band, a ring-shaped peripheral microtubule bundle, and displayed properties of bona fide microtubule-associated proteins such as tau. Red blood cell ferritin association with the marginal band was confirmed by temperature-induced disassembly-reassembly of microtubules. During erythrocyte differentiation, ferritin co-localized with coalescing microtubules during marginal band formation. In addition, ferritin was found in the nuclei of mature erythrocytes, but was not detectable in those of bone marrow erythrocyte precursors. These results suggest that ferritin has a function in marginal band formation and possibly in protection of the marginal band from damaging effects of reactive oxygen species by sequestering iron in the mature erythrocyte. Moreover, our data suggest that ferritin and syncolin, a previously identified erythrocyte microtubule-associated protein, are identical. Nuclear ferritin might contribute to transcriptional silencing or, alternatively, constitute a ferritin reservoir

  6. Excited negative parity bands in 160Yb

    Science.gov (United States)

    Saha, A.; Bhattacharjee, T.; Curien, D.; Dedes, I.; Mazurek, K.; Banerjee, S. R.; Rajbanshi, S.; Bisoi, A.; de Angelis, G.; Bhattacharya, Soumik; Bhattacharyya, S.; Biswas, S.; Chakraborty, A.; Das Gupta, S.; Dey, B.; Goswami, A.; Mondal, D.; Pandit, D.; Palit, R.; Roy, T.; Singh, R. P.; Saha Sarkar, M.; Saha, S.; Sethi, J.

    2018-03-01

    Negative parity rotational bands in {} 70160Yb{}90 nucleus have been studied. They were populated in the 148Sm(16O, 4n)160Yb reaction at 90 MeV. The gamma-coincidence data have been collected using Indian National Gamma Array composed of twenty Compton suppressed clover germanium (Ge) detectors. Double gating on triple gamma coincidence data were selectively used to develop the decay scheme for these negative parity bands by identifying and taking care of the multiplet transitions. The even- and odd-spin negative parity bands in 160Yb have been studied by comparing the reduced transition probability ratios with the similar bands in neighbouring even-even rare earth nuclei. It is concluded that the concerned odd-spin and even-spin bands are not signature partners and that their structures are compatible with those of the ‘pear-shape’ and ‘pyramid-shape’ oscillations, respectively, the octupole shapes superposed with the quadrupole shape of the ground-state.

  7. Self-assembly of colloidal bands driven by a periodic external field

    Energy Technology Data Exchange (ETDEWEB)

    Nunes, André S.; Araújo, Nuno A. M., E-mail: nmaraujo@fc.ul.pt; Telo da Gama, Margarida M. [Departamento de Física, Faculdade de Ciências, Universidade de Lisboa, P-1749-016 Lisboa, Portugal and Centro de Física Teórica e Computacional, Universidade de Lisboa, P-1749-016 Lisboa (Portugal)

    2016-01-21

    We study the formation of bands of colloidal particles driven by periodic external fields. Using Brownian dynamics, we determine the dependence of the band width on the strength of the particle interactions and on the intensity and periodicity of the field. We also investigate the switching (field-on) dynamics and the relaxation times as a function of the system parameters. The observed scaling relations were analyzed using a simple dynamic density-functional theory of fluids.

  8. Rubber band ligation and infrared photocoagulation for the outpatient treatment of hemorrhoidal disease.

    Science.gov (United States)

    Ricci, Maurício Pichler; Matos, Délcio; Saad, Sarhan Sydney

    2008-01-01

    To compare the results of rubber band ligation and infrared photocoagulation for the treatment of hemorrhoidal disease through the analysis of the incidence of complications after each treatment and respective success rate. Forty-eight patients with first, second or third degree hemorrhoidal disease were randomized to receive treatment with either rubber band ligation (n=23) or infrared photocoagulation (n=25). Each patient was assessed at 1 week and 4 week intervals after treatment. We compared the incidence of complications and efficiency of each treatment modality and Qui-square, Fisher's Exact Test and Student's t Test were used to statistical analysis. Bleeding occured in eight (34,7%) patients treated with rubber band ligation and in four (16,0%) after infrared photocoagulation (p=0,243). Thirteen (52,0%) patients felt pain during infrared photocoagulation and 9 (39,1%) after rubber band ligation (p=0,546). After rubber band ligation, 14 (60,8%) required medication for pain relief. One patient (4,0%) required medication after infrared photocoagulation (prubber band ligator and 1 (4,0%) treated with infrared photocoagulation had symptomatic mucosal ulcers. Perianal dermatitis occured in two (8,0%) patients treated with infrared photocoagulation and one patient (4,3%) was observed to have prolapsed thrombosed piles after rubber band ligation. One month after treatment, 17 of 23 patients treated with rubber band ligation (73,9%) and 18 of 25 patients treated with infrared photocoagulation were asymptomatic. Rubber band ligation treated bleeding and prolapse in 90,0% and 82,4% respectively. Infrared photocoagulation treats bleeding and prolapse in 93,7% and 87,5% respectively. Those differences are not significant. Rubber band ligation causes significantly more pain than infrared photocoagulation during the first week after the procedures and their success rate are not different after four weeks of treatment.

  9. Deformation-Induced Microstructural Banding in TRIP Steels

    Science.gov (United States)

    Celotto, S.; Ghadbeigi, H.; Pinna, C.; Shollock, B. A.; Efthymiadis, P.

    2018-05-01

    Microstructure inhomogeneities can strongly influence the mechanical properties of advanced high-strength steels in a detrimental manner. This study of a transformation-induced plasticity (TRIP) steel investigates the effect of pre-existing contiguous grain boundary networks (CGBNs) of hard second-phases and shows how these develop into bands during tensile testing using in situ observations in conjunction with digital image correlation (DIC). The bands form by the lateral contraction of the soft ferrite matrix, which rotates and displaces the CGBNs of second-phases and the individual features within them to become aligned with the loading direction. The more extensive pre-existing CGBNs that were before the deformation already aligned with the loading direction are the most critical microstructural feature for damage initiation and propagation. They induce micro-void formation between the hard second-phases along them, which coalesce and develop into long macroscopic fissures. The hard phases, retained austenite and martensite, were not differentiated as it was found that the individual phases do not play a role in the formation of these bands. It is suggested that minimizing the presence of CGBNs of hard second-phases in the initial microstructure will increase the formability.

  10. Band gap engineering of indium zinc oxide by nitrogen incorporation

    Energy Technology Data Exchange (ETDEWEB)

    Ortega, J.J., E-mail: jjosila@hotmail.com [Unidad Académica de Física, Universidad Autónoma de Zacatecas, Calzada Solidaridad esq. Paseo la Bufa, Fracc. Progreso, C.P. 98060 Zacatecas (Mexico); Doctorado Institucional de Ingeniería y Ciencia de Materiales, Universidad Autónoma de San Luis Potosí, Av. Salvador Nava, Zona Universitaria, C.P. 78270 San Luis Potosí (Mexico); Aguilar-Frutis, M.A.; Alarcón, G. [Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada del Instituto Politécnico Nacional, Unidad Legaría, Calz. Legaría No. 694, Col. Irrigación, C.P. 11500 México D.F. (Mexico); Falcony, C. [Departamento de Física, Centro de Investigación y Estudios Avanzados del Instituto Politécnico Nacional campus Zacatenco, Av. Instituto Politécnico Nacional 2508, Col. San Pedro Zacatenco, C.P. 07360 México D.F. (Mexico); and others

    2014-09-15

    Highlights: • IZON thin films were deposited by RF reactive sputtering at room temperature. • The effects of nitrogen on physical properties of IZO were analyzed. • Optical properties of IZON were studied by SE and UV–vis spectroscopy. • Adachi and classical parameters were quantitative and qualitatively congruent. • Nitrogen induces a gradual narrowing band gap from 3.5 to 2.5 eV on IZON films. - Abstract: The effects of nitrogen incorporation in indium zinc oxide films, as grown by RF reactive magnetron sputtering, on the structural, electrical and optical properties were studied. It was determined that the variation of the N{sub 2}/Ar ratio, in the reactive gas flux, was directly proportional to the nitrogen percentage measured in the sample, and the incorporated nitrogen, which substituted oxygen in the films induces changes in the band gap of the films. This phenomenon was observed by measurement of absorption and transmission spectroscopy in conjunction with spectral ellipsometry. To fit the ellipsometry spectra, the classical and Adachi dispersion models were used. The obtained optical parameters presented notable changes related to the increment of the nitrogen in the film. The band gap narrowed from 3.5 to 2.5 eV as the N{sub 2}/Ar ratio was increased. The lowest resistivity obtained for these films was 3.8 × 10{sup −4} Ω cm with a carrier concentration of 5.1 × 10{sup 20} cm{sup −3}.

  11. Band gap engineering of indium zinc oxide by nitrogen incorporation

    International Nuclear Information System (INIS)

    Ortega, J.J.; Aguilar-Frutis, M.A.; Alarcón, G.; Falcony, C.

    2014-01-01

    Highlights: • IZON thin films were deposited by RF reactive sputtering at room temperature. • The effects of nitrogen on physical properties of IZO were analyzed. • Optical properties of IZON were studied by SE and UV–vis spectroscopy. • Adachi and classical parameters were quantitative and qualitatively congruent. • Nitrogen induces a gradual narrowing band gap from 3.5 to 2.5 eV on IZON films. - Abstract: The effects of nitrogen incorporation in indium zinc oxide films, as grown by RF reactive magnetron sputtering, on the structural, electrical and optical properties were studied. It was determined that the variation of the N 2 /Ar ratio, in the reactive gas flux, was directly proportional to the nitrogen percentage measured in the sample, and the incorporated nitrogen, which substituted oxygen in the films induces changes in the band gap of the films. This phenomenon was observed by measurement of absorption and transmission spectroscopy in conjunction with spectral ellipsometry. To fit the ellipsometry spectra, the classical and Adachi dispersion models were used. The obtained optical parameters presented notable changes related to the increment of the nitrogen in the film. The band gap narrowed from 3.5 to 2.5 eV as the N 2 /Ar ratio was increased. The lowest resistivity obtained for these films was 3.8 × 10 −4 Ω cm with a carrier concentration of 5.1 × 10 20 cm −3

  12. Modulation of EEG Theta Band Signal Complexity by Music Therapy

    Science.gov (United States)

    Bhattacharya, Joydeep; Lee, Eun-Jeong

    The primary goal of this study was to investigate the impact of monochord (MC) sounds, a type of archaic sounds used in music therapy, on the neural complexity of EEG signals obtained from patients undergoing chemotherapy. The secondary goal was to compare the EEG signal complexity values for monochords with those for progressive muscle relaxation (PMR), an alternative therapy for relaxation. Forty cancer patients were randomly allocated to one of the two relaxation groups, MC and PMR, over a period of six months; continuous EEG signals were recorded during the first and last sessions. EEG signals were analyzed by applying signal mode complexity, a measure of complexity of neuronal oscillations. Across sessions, both groups showed a modulation of complexity of beta-2 band (20-29Hz) at midfrontal regions, but only MC group showed a modulation of complexity of theta band (3.5-7.5Hz) at posterior regions. Therefore, the neuronal complexity patterns showed different changes in EEG frequency band specific complexity resulting in two different types of interventions. Moreover, the different neural responses to listening to monochords and PMR were observed after regular relaxation interventions over a short time span.

  13. Determination of Primary Spectral Bands for Remote Sensing of Aquatic Environments

    Directory of Open Access Journals (Sweden)

    MingXia He

    2007-12-01

    Full Text Available About 30 years ago, NASA launched the first ocean-color observing satellite:the Coastal Zone Color Scanner. CZCS had 5 bands in the visible-infrared domain with anobjective to detect changes of phytoplankton (measured by concentration of chlorophyll inthe oceans. Twenty years later, for the same objective but with advanced technology, theSea-viewing Wide Field-of-view Sensor (SeaWiFS, 7 bands, the Moderate-ResolutionImaging Spectrometer (MODIS, 8 bands, and the Medium Resolution ImagingSpectrometer (MERIS, 12 bands were launched. The selection of the number of bands andtheir positions was based on experimental and theoretical results achieved before thedesign of these satellite sensors. Recently, Lee and Carder (2002 demonstrated that foradequate derivation of major properties (phytoplankton biomass, colored dissolved organicmatter, suspended sediments, and bottom properties in both oceanic and coastalenvironments from observation of water color, it is better for a sensor to have ~15 bands inthe 400 – 800 nm range. In that study, however, it did not provide detailed analysesregarding the spectral locations of the 15 bands. Here, from nearly 400 hyperspectral (~ 3-nm resolution measurements of remote-sensing reflectance (a measure of water colortaken in both coastal and oceanic waters covering both optically deep and optically shallowwaters, first- and second-order derivatives were calculated after interpolating themeasurements to 1-nm resolution. From these derivatives, the frequency of zero values foreach wavelength was accounted for, and the distribution spectrum of such frequencies wasobtained. Furthermore, the wavelengths that have the highest appearance of zeros wereidentified. Because these spectral locations indicate extrema (a local maximum orminimum of the reflectance spectrum or inflections of the spectral curvature, placing the bands of a sensor at these wavelengths maximizes the potential of capturing (and then restoring

  14. Band gaps for the relativistic Mathieu potential

    International Nuclear Information System (INIS)

    Clerk, G.J.; McKellar, B.H.J.

    1992-01-01

    A study of the band structure of a massless particle in a cosine potential is made via the Dirac equation. It is shown that every alternate band gap disappears as a consequence of a periodicity of the potential combined with a peculiar symmetry of the Dirac equation. This basic potential is then used to study a simple one-dimensional model of the nucleus from which it is ascertained that modelling the mean field of the quarks in the nucleus via a pure scalar potential is unsatisfactory. A simple extension involving a combined scalar and vector potential is then proposed as a possible solution to this problem. The effect of the addition of this vector component to the band structure is also investigated. 32 refs

  15. What band rocks the MTB? (Invited)

    Science.gov (United States)

    Kind, J.; García-Rubio, I.; Gehring, A. U.

    2013-12-01

    Magnetotactic bacteria (MTB) are a polyphyletic group of bacteria that have been found in marine and lacustrine environments and soils [e.g. 1]. The hallmark of MTB is their intracellular formation of magnetosomes, single-domain ferrimagnetic particles that are aligned in chains. The chain configuration generates a strong magnetic dipole, which is used as magnetic compass to move the MTB into their favorable habit. The term band corresponds to a frequency window of microwaves in the gigahertz (GHz) range. Ferromagnetic resonance (FMR) spectroscopy uses the microwave absorption in a magnetic field to analyze the anisotropy properties and the domain state of magnetic materials. Specific microwave frequency causes absorption in a characteristic magnetic field range. For the investigation of MTB we use S-band (4.02 GHz), X-band (9.47 GHz), and Q-band (34.16 GHz). Experiments on cultured MTB and on sediment samples of Holocene age showed that absorption in X- and Q-band occurs when the sample is in a saturated or nearly saturated state [2, 3]. By contrast, absorption in the S-band appears in lower magnetic fields, where the sample is far from saturation. All FMR spectra show two distinct low-field features that can be assigned to magnetite particles in chains, aligned parallel and perpendicular to the external magnetic field. The detailed separation of the parallel and perpendicular components in the bulk samples is hampered, because of the random orientation of the chains in the sample. The comparison of S-, X-, and Q-band shows that the lower the frequency the better the separation of the components. In the S-band FMR spectroscopy, the separation of chains parallel to the external magnetic field is supported by the internal field of the sample. This field is caused by the remanence that contributes to the external magnetic field to fulfill the resonance condition [3,4]. Considering the different FMR responses, it can be postulated that a lower microwave frequency

  16. Simplicial band depth for multivariate functional data

    KAUST Repository

    López-Pintado, Sara

    2014-03-05

    We propose notions of simplicial band depth for multivariate functional data that extend the univariate functional band depth. The proposed simplicial band depths provide simple and natural criteria to measure the centrality of a trajectory within a sample of curves. Based on these depths, a sample of multivariate curves can be ordered from the center outward and order statistics can be defined. Properties of the proposed depths, such as invariance and consistency, can be established. A simulation study shows the robustness of this new definition of depth and the advantages of using a multivariate depth versus the marginal depths for detecting outliers. Real data examples from growth curves and signature data are used to illustrate the performance and usefulness of the proposed depths. © 2014 Springer-Verlag Berlin Heidelberg.

  17. Exact folded-band chaotic oscillator.

    Science.gov (United States)

    Corron, Ned J; Blakely, Jonathan N

    2012-06-01

    An exactly solvable chaotic oscillator with folded-band dynamics is shown. The oscillator is a hybrid dynamical system containing a linear ordinary differential equation and a nonlinear switching condition. Bounded oscillations are provably chaotic, and successive waveform maxima yield a one-dimensional piecewise-linear return map with segments of both positive and negative slopes. Continuous-time dynamics exhibit a folded-band topology similar to Rössler's oscillator. An exact solution is written as a linear convolution of a fixed basis pulse and a discrete binary sequence, from which an equivalent symbolic dynamics is obtained. The folded-band topology is shown to be dependent on the symbol grammar.

  18. 193Hg collective oblate band with Ex>5.7 MeV

    International Nuclear Information System (INIS)

    Roy, N.; Henry, E.A.; Becker, J.A.

    1993-01-01

    Rotational bands in the neutron-deficient Pb nuclei 192,194,196-201 Pb have been reported recently. Band members are connected by L = 1 transitions, with crossover L = 2 transitions observed at the higher γ-ray energies. Regular and irregular patterns of γ-ray energies are observed. Conversion coefficients determined from intensity balance suggest the L = 1 transitions are M1. The bands have generally been interpreted as collective oblate, involving deformation aligned high-j proton configurations such as π(s 1/2 -2 h 9/2 i 13/2 ), and rotation aligned i 13/2 -n neutrons. Evidence for a similar band in 193 Hg has been obtained. 193 Hg was populated in the reaction 176 Yb( 22 Ne,5n) at E i ( 22 Ne) = 110 MeV. Reaction γ rays were detected with the Ge detector array HERA. A new 'collective' structure was observed with E x >5.7 MeV. States of the structure extend from I≥47/2 to I +10, and they decay with competing dipole and quadrupole transitions. The ratio B(M1)/B(E2), ∼ 2μ 2 /(e b) 2 , is approximately 10x lower in 193 Hg than in the Pb bands. The lowest member is produced with ∼20% of the 193 Hg cross section. Evidence for a similar band in 196 Hg will be presented at this meeting

  19. Side-band-separating heterodyne mixer for band 9 of ALMA.

    NARCIS (Netherlands)

    Mena, F. P.; Baryshev, A. M.; Kooi, J.; Lodewijk, C. F. J.; Gerlofsma, G.; Hesper, R.; Wild, W.; Shen, XC; Lu, W; Zhang, J; Dou, WB

    2006-01-01

    Here we present the realization of a side-band-separating (2SB) heterodyne mixer for the frequency range from 602 to 720 GHz (corresponding to ALMA band 9). The mixer, in brief, consists of a quadrature hybrid, two LO injectors, two SIS junctions, and three dumping loads. All the parts were modeled

  20. Elastic band prediction equations for combined free-weight and elastic band bench presses and squats.

    Science.gov (United States)

    Shoepe, Todd C; Ramirez, David A; Almstedt, Hawley C

    2010-01-01

    Elastic bands added to traditional free-weight techniques have become a part of suggested training routines in recent years. Because of the variable loading patterns of elastic bands (i.e., greater stretch produces greater resistance), it is necessary to quantify the exact loading patterns of bands to identify the volume and intensity of training. The purpose of this study was to determine the length vs. tension properties of multiple sizes of a set of commonly used elastic bands to quantify the resistance that would be applied to free-weight plus elastic bench presses (BP) and squats (SQ). Five elastic bands of varying thickness were affixed to an overhead support beam. Dumbbells of varying weights were progressively added to the free end while the linear deformation was recorded with each subsequent weight increment. The resistance was plotted as a factor of linear deformation, and best-fit nonlinear logarithmic regression equations were then matched to the data. For both the BP and SQ loading conditions and all band thicknesses tested, R values were greater than 0.9623. These data suggest that differences in load exist as a result of the thickness of the elastic band, attachment technique, and type of exercise being performed. Facilities should adopt their own form of loading quantification to match their unique set of circumstances when acquiring, researching, and implementing elastic band and free-weight exercises into the training programs.

  1. Band-gap and band-edge engineering of multicomponent garnet scintillators from first principles

    Czech Academy of Sciences Publication Activity Database

    Yadav, S.K.; Uberuaga, B.P.; Nikl, Martin; Jiang, C.; Stanek, C.R.

    2015-01-01

    Roč. 4, č. 5 (2015), "054012-1"-"054012-9" ISSN 2331-7019 R&D Projects: GA ČR GAP204/12/0805 Institutional support: RVO:68378271 Keywords : scintillator * electronic band gap structure * garnets * band gap engineering Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 4.061, year: 2015

  2. Interpolation of band-limited discrete-time signals by minimising out-of-band energy

    NARCIS (Netherlands)

    Janssen, A.J.E.M.; Vries, L.B.

    1984-01-01

    An interpolation method for restoring burst errors in discrete—time, band—limited signals is presented. The restoration is such that the restored signal has minimal out—of—band energy. The filter coefficients depend Only on the burst length and on the size of the band to which the signal is assumed

  3. Band to Band Tunneling (BBT) Induced Leakage Current Enhancement in Irradiated Fully Depleted SOI Devices

    Science.gov (United States)

    Adell, Phillipe C.; Barnaby, H. J.; Schrimpf, R. D.; Vermeire, B.

    2007-01-01

    We propose a model, validated with simulations, describing how band-to-band tunneling (BBT) affects the leakage current degradation in some irradiated fully-depleted SOI devices. The dependence of drain current on gate voltage, including the apparent transition to a high current regime is explained.

  4. Modelling band-to-band tunneling current in InP-based heterostructure photonic devices

    NARCIS (Netherlands)

    van Engelen, J.P.; Shen, L.; van der Tol, J.J.G.M.; Smit, M.K.; Kockaert, P.; Emplit, P.; Gorza, S.-P.; Massar, S.

    2015-01-01

    Some semiconductor photonic devices show large discontinuities in the band structure. Short tunnel paths caused by this band structure may lead to an excessive tunneling current, especially in highly doped layers. Modelling of this tunnelling current is therefore important when designing photonic

  5. An L Band Spectrum of the Coldest Brown Dwarf

    Science.gov (United States)

    Morley, Caroline V.; Skemer, Andrew J.; Allers, Katelyn N.; Marley, Mark. S.; Faherty, Jacqueline K.; Visscher, Channon; Beiler, Samuel A.; Miles, Brittany E.; Lupu, Roxana; Freedman, Richard S.; Fortney, Jonathan J.; Geballe, Thomas R.; Bjoraker, Gordon L.

    2018-05-01

    The coldest brown dwarf, WISE 0855, is the closest known planetary-mass, free-floating object and has a temperature nearly as cold as the solar system gas giants. Like Jupiter, it is predicted to have an atmosphere rich in methane, water, and ammonia, with clouds of volatile ices. WISE 0855 is faint at near-infrared wavelengths and emits almost all its energy in the mid-infrared. Skemer et al. presented a spectrum of WISE 0855 from 4.5–5.1 μm (M band), revealing water vapor features. Here, we present a spectrum of WISE 0855 in the L band, from 3.4–4.14 μm. We present a set of atmosphere models that include a range of compositions (metallicities and C/O ratios) and water ice clouds. Methane absorption is clearly present in the spectrum. The mid-infrared color can be better matched with a methane abundance that is depleted relative to solar abundance. We find that there is evidence for water ice clouds in the M band spectrum, and we find a lack of phosphine spectral features in both the L and M band spectra. We suggest that a deep continuum opacity source may be obscuring the near-infrared flux, possibly a deep phosphorous-bearing cloud, ammonium dihyrogen phosphate. Observations of WISE 0855 provide critical constraints for cold planetary atmospheres, bridging the temperature range between the long-studied solar system planets and accessible exoplanets. The James Webb Space Telescope will soon revolutionize our understanding of cold brown dwarfs with high-precision spectroscopy across the infrared, allowing us to study their compositions and cloud properties, and to infer their atmospheric dynamics and formation processes.

  6. Mapping Greenland's Firn Aquifer using L-band Microwave Radiometry

    Science.gov (United States)

    Miller, J.; Bringer, A.; Jezek, K. C.; Johnson, J. T.; Scambos, T. A.; Long, D. G.

    2016-12-01

    Greenland's recently discovered firn aquifer is one of the most interesting, yet still mysterious, components of the ice sheet system. Many open questions remain regarding timescales of refreezing and/or englacial drainage of liquid meltwater, and the connections of firn aquifers to the subglacial hydrological system. If liquid meltwater production at the surface of the Greenland ice sheet continues to increase, subsequent increases in the volume of mobile liquid meltwater retained within Greenland's firn aquifer may increase the possibility of crevasse-deepening via hydrofracture. Hydrofracture is an important component of supraglacial lake drainage leading to at least temporary accelerated flow velocities and ice sheet mass balance changes. Firn aquifers may also support hydrofracture-induced drainage and thus are potentially capable of significantly influencing ice sheet mass balance and sea level rise. Spaceborne L-band microwave radiometers provide an innovative tool for ice-sheet wide mapping of the spatiotemporal variability of Greenland's firn aquifer. Both refreezing and englacial drainage may be observable given the sensitivity of the microwave response to the upper surface of liquid meltwater retained within snow and firn pore space as well as the ability of L band instruments to probe the ice sheet from the surface to the firn-ice transition at pore close-off depth. Here we combine L-band (1.4 GHz) brightness temperature observations from multiple sources to demonstrate the potential of mapping firn aquifers on ice sheets using L-band microwave radiometry. Data sources include the interferometric MIRAS instrument aboard ESA's Soil Moisture and Ocean Salinity (SMOS) satellite mission and the radiometer aboard NASA's Soil Moisture Active Passive (SMAP) satellite mission. We will also present mulit-frequency L-band brightness temperature data (0.5-2 GHz) that will be collected over several firn aquifer areas on the Greenland ice sheet by the Ohio State

  7. Understanding type Ia supernovae through their U-band spectra

    Science.gov (United States)

    Nordin, J.; Aldering, G.; Antilogus, P.; Aragon, C.; Bailey, S.; Baltay, C.; Barbary, K.; Bongard, S.; Boone, K.; Brinnel, V.; Buton, C.; Childress, M.; Chotard, N.; Copin, Y.; Dixon, S.; Fagrelius, P.; Feindt, U.; Fouchez, D.; Gangler, E.; Hayden, B.; Hillebrandt, W.; Kim, A.; Kowalski, M.; Kuesters, D.; Leget, P.-F.; Lombardo, S.; Lin, Q.; Pain, R.; Pecontal, E.; Pereira, R.; Perlmutter, S.; Rabinowitz, D.; Rigault, M.; Runge, K.; Rubin, D.; Saunders, C.; Smadja, G.; Sofiatti, C.; Suzuki, N.; Taubenberger, S.; Tao, C.; Thomas, R. C.; Nearby Supernova Factory

    2018-06-01

    Context. Observations of type Ia supernovae (SNe Ia) can be used to derive accurate cosmological distances through empirical standardization techniques. Despite this success neither the progenitors of SNe Ia nor the explosion process are fully understood. The U-band region has been less well observed for nearby SNe, due to technical challenges, but is the most readily accessible band for high-redshift SNe. Aims: Using spectrophotometry from the Nearby Supernova Factory, we study the origin and extent of U-band spectroscopic variations in SNe Ia and explore consequences for their standardization and the potential for providing new insights into the explosion process. Methods: We divide the U-band spectrum into four wavelength regions λ(uNi), λ(uTi), λ(uSi) and λ(uCa). Two of these span the Ca H&K λλ 3934, 3969 complex. We employ spectral synthesis using SYNAPPS to associate the two bluer regions with Ni/Co and Ti. Results: The flux of the uTi feature is an extremely sensitive temperature/luminosity indicator, standardizing the SN peak luminosity to 0.116 ± 0.011 mag root mean square (RMS). A traditional SALT2.4 fit on the same sample yields a 0.135 mag RMS. Standardization using uTi also reduces the difference in corrected magnitude between SNe originating from different host galaxy environments. Early U-band spectra can be used to probe the Ni+Co distribution in the ejecta, thus offering a rare window into the source of light curve power. The uCa flux further improves standardization, yielding a 0.086 ± 0.010 mag RMS without the need to include an additional intrinsic dispersion to reach χ2/dof 1. This reduction in RMS is partially driven by an improved standardization of Shallow Silicon and 91T-like SNe. All tables are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/614/A71. Individual SN spectra shown are available at http://snfactory.lbl.gov/snf/data

  8. Linkage Map of the Long Arm of Barley Chromosome 3 Using C-Bands and Marker Genes

    DEFF Research Database (Denmark)

    Linde-Laursen, Ib

    1982-01-01

    locations. No recombination was observed between the two proximal C-band locations whereas the two distal locations recombined with a frequency of 12 2 per cent. The three C-band locations were linked with loci cer-zd, uz, and cer-zn, but not with the tightly linked loci Est-1 and Est-4. The order...

  9. Structure of dipole bands in 106In

    International Nuclear Information System (INIS)

    Deo, A. Y.; Palit, R.; Naik, Z.; Joshi, P. K.; Mazumdar, I.; Sihotra, S.; Mehta, D.; Kumar, S.; Chakrabarti, R.; Kshetri, R.; Jain, H. C.

    2009-01-01

    High spin states in neutron-deficient 106 In were investigated using 78 Se( 32 S,p3n) reaction at 125 MeV. The level scheme is extended up to 7 MeV of excitation energy for the negative parity states constituting four dipole bands, and the positive parity states which mainly exhibit single-particle excitations are extended up to 5 MeV. Projected deformed Hartree-Fock calculations were carried out to understand the configurations of different bands in this nucleus.

  10. Maximizing band gaps in plate structures

    DEFF Research Database (Denmark)

    Halkjær, Søren; Sigmund, Ole; Jensen, Jakob Søndergaard

    2006-01-01

    periodic plate using Bloch theory, which conveniently reduces the maximization problem to that of a single base cell. Secondly, we construct a finite periodic plate using a number of the optimized base cells in a postprocessed version. The dynamic properties of the finite plate are investigated......Band gaps, i.e., frequency ranges in which waves cannot propagate, can be found in elastic structures for which there is a certain periodic modulation of the material properties or structure. In this paper, we maximize the band gap size for bending waves in a Mindlin plate. We analyze an infinite...... theoretically and experimentally and the issue of finite size effects is addressed....

  11. Itinerant ferromagnetism in the narrow band limit

    CERN Document Server

    Liu, S H

    2000-01-01

    It is shown that in the narrow band, strong interaction limit the paramagnetic state of an itinerant ferromagnet is described by the disordered local moment state. As a result, the Curie temperature is orders of magnitude lower than what is expected from the large exchange splitting of the spin bands. An approximate analysis has also been carried out for the partially ordered state, and the result explains the temperature evolvement of the magnetic contributions to the resistivity and low-energy optical conductivity of CrO sub 2.

  12. Proximal iliotibial band syndrome: case report

    Directory of Open Access Journals (Sweden)

    Guilherme Guadagnini Falotico

    2013-08-01

    Full Text Available OBJECTIVE: The overuse injuries in the hip joint occur commonly in sports practitioners and currently due to technical advances in diagnostic imaging, especially magnetic resonance imaging (MRI, are often misdiagnosed. Recently, a group of people were reported, all female, with pain and swelling in the pelvic region.T2-weighted MRI showed increased signal in the enthesis of the iliotibial band (ITB along the lower border of the iliac tubercle. We report a case of a 34 year old woman, non-professional runner, with pain at the iliac crest with no history of trauma and whose MRI was compatible with the proximal iliotibial band syndrome.

  13. Electron currents associated with an auroral band

    International Nuclear Information System (INIS)

    Spiger, R.J.; Anderson, H.R.

    1975-01-01

    Measurements of electron pitch angle distributions and energy spectra over a broad auroral band were used to calculate net electric current carried by auroral electrons in the vicinity of the band. The particle energy spectrometers were carried by a Nike-Tomahawk rocket launched from Poker Flat, Alaska, at 0722 UT on February 25, 1972. Data are presented which indicate the existence of upward field-aligned currents of electrons in the energy range 0.5-20 keV. The spatial relationship of these currents to visual structure of the auroral arc and the characteristics of the electrons carrying the currents are discussed

  14. Electron currents associated with an auroral band

    Science.gov (United States)

    Spiger, R. J.; Anderson, H. R.

    1975-01-01

    Measurements of electron pitch angle distributions and energy spectra over a broad auroral band were used to calculate net electric current carried by auroral electrons in the vicinity of the band. The particle energy spectrometers were carried by a Nike-Tomahawk rocket launched from Poker Flat, Alaska, at 0722 UT on February 25, 1972. Data are presented which indicate the existence of upward field-aligned currents of electrons in the energy range 0.5-20 keV. The spatial relationship of these currents to visual structure of the auroral arc and the characteristics of the electrons carrying the currents are discussed.

  15. Band theory of metals the elements

    CERN Document Server

    Altmann, Simon L

    1970-01-01

    Band Theory of Metals: The Elements focuses on the band theory of solids. The book first discusses revision of quantum mechanics. Topics include Heisenberg's uncertainty principle, normalization, stationary states, wave and group velocities, mean values, and variational method. The text takes a look at the free-electron theory of metals, including heat capacities, density of states, Fermi energy, core and metal electrons, and eigenfunctions in three dimensions. The book also reviews the effects of crystal fields in one dimension. The eigenfunctions of the translations; symmetry operations of t

  16. Banding of connection standards for distributed generation

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-05-04

    This report presents the views of distributed network operators (DNOs), developers, equipment manufacturers and consultants on the current banding of distributed generation in terms of connection standards and recommendations. The Documents ER G59/1, ER G75/1, ER G83/1 and ETR 113/1 covering recommendations for the connection of embedded generating plant to distribution systems and guidance notes for the protection of embedded generating plant are examined. The way in which the recommendations are applied in practice is investigated. Multiple distribution generator installations, fault ride through, and banding are considered as well as both protection required and maximum generator sizes at respective voltage levels.

  17. Quantum numbers and band topology of nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Damnjanovic, M [Faculty of Physics, University of Belgrade, POB 368, 11001 Belgrade (Yugoslavia); Milosevic, I [Faculty of Physics, University of Belgrade, POB 368, 11001 Belgrade (Yugoslavia); Vukovic, T [Faculty of Physics, University of Belgrade, POB 368, 11001 Belgrade (Yugoslavia); Maultzsch, J [Institut fuer Festkoerper Physik, Technische Universitaet Berlin, Hardenbergstr. 36, 10623 Berlin (Germany)

    2003-05-30

    Nanotubes as well as polymers and quasi-1D subsystems of 3D crystals have line group symmetry. This allows two types of quantum numbers: roto-translational and helical. The roto-translational quantum numbers are linear and total angular (not conserved) momenta, while the helical quantum numbers are helical and complementary angular momenta. Their mutual relations determine some topological properties of energy bands, such as systematic band sticking or van Hove singularities related to parities. The importance of these conclusions is illustrated by the optical absorption in carbon nanotubes: parity may prevent absorption peaks at van Hove singularities.

  18. Quantum numbers and band topology of nanotubes

    International Nuclear Information System (INIS)

    Damnjanovic, M; Milosevic, I; Vukovic, T; Maultzsch, J

    2003-01-01

    Nanotubes as well as polymers and quasi-1D subsystems of 3D crystals have line group symmetry. This allows two types of quantum numbers: roto-translational and helical. The roto-translational quantum numbers are linear and total angular (not conserved) momenta, while the helical quantum numbers are helical and complementary angular momenta. Their mutual relations determine some topological properties of energy bands, such as systematic band sticking or van Hove singularities related to parities. The importance of these conclusions is illustrated by the optical absorption in carbon nanotubes: parity may prevent absorption peaks at van Hove singularities

  19. Quantum numbers and band topology of nanotubes

    CERN Document Server

    Damnjanovic, M; Vukovic, T; Maultzsch, J

    2003-01-01

    Nanotubes as well as polymers and quasi-1D subsystems of 3D crystals have line group symmetry. This allows two types of quantum numbers: roto-translational and helical. The roto-translational quantum numbers are linear and total angular (not conserved) momenta, while the helical quantum numbers are helical and complementary angular momenta. Their mutual relations determine some topological properties of energy bands, such as systematic band sticking or van Hove singularities related to parities. The importance of these conclusions is illustrated by the optical absorption in carbon nanotubes: parity may prevent absorption peaks at van Hove singularities.

  20. Neutron transmission bands in one dimensional lattices

    International Nuclear Information System (INIS)

    Monsivais, G.; Moshinsky, M.

    1999-01-01

    The original Kronig-Penney lattice, which had delta function interactions at the end of each of the equal segments, seems a good model for the motion of neutrons in a linear lattice if the strength b of the δ functions depends of the energy of the neutrons, i.e., b(E). We derive the equation for the transmission bands and consider the relations of b(E) with the R(E) function discussed in a previous paper. We note the great difference in the behavior of the bands when b(E) is constant and when it is related with a single resonance of the R function. (Author)

  1. In-clustering induced anomalousbehavior of band gap in InAlN and InGaN

    DEFF Research Database (Denmark)

    Gorczyca, I.; Suski, T.; Christensen, Niels Egede

    2010-01-01

    Electronic band structure calculations of In containing ternary nitride alloys are presented showing a strong modification of the band gap, EG and its pressure coefficient, dEG/dp, as a function of In-content. Two different arrangements of In atoms are considered: uniform and clustered. It is shown...... that Indium clustering is the additional, large factor leading to the unusual bowings of the band gaps and their pressure coefficients. The theoretical results are compared with experimental data on variations of EG with In content. In the analysis of observed phenomena we point out the particular role...... of the uppermost valence band....

  2. Coastal flood inundation monitoring with Satellite C-band and L-band Synthetic Aperture Radar data

    Science.gov (United States)

    Ramsey, Elijah W.; Rangoonwala, Amina; Bannister, Terri

    2013-01-01

    Satellite Synthetic Aperture Radar (SAR) was evaluated as a method to operationally monitor the occurrence and distribution of storm- and tidal-related flooding of spatially extensive coastal marshes within the north-central Gulf of Mexico. Maps representing the occurrence of marsh surface inundation were created from available Advanced Land Observation Satellite (ALOS) Phased Array type L-Band SAR (PALSAR) (L-band) (21 scenes with HH polarizations in Wide Beam [100 m]) data and Environmental Satellite (ENVISAT) Advanced SAR (ASAR) (C-band) data (24 scenes with VV and HH polarizations in Wide Swath [150 m]) during 2006-2009 covering 500 km of the Louisiana coastal zone. Mapping was primarily based on a decrease in backscatter between reference and target scenes, and as an extension of previous studies, the flood inundation mapping performance was assessed by the degree of correspondence between inundation mapping and inland water levels. Both PALSAR- and ASAR-based mapping at times were based on suboptimal reference scenes; however, ASAR performance seemed more sensitive to reference-scene quality and other types of scene variability. Related to water depth, PALSAR and ASAR mapping accuracies tended to be lower when water depths were shallow and increased as water levels decreased below or increased above the ground surface, but this pattern was more pronounced with ASAR. Overall, PALSAR-based inundation accuracies averaged 84% (n = 160), while ASAR-based mapping accuracies averaged 62% (n = 245).

  3. Band 3 Erythrocyte Membrane Protein Acts as Redox Stress Sensor Leading to Its Phosphorylation by p72 Syk

    Directory of Open Access Journals (Sweden)

    Antonella Pantaleo

    2016-01-01

    Full Text Available In erythrocytes, the regulation of the redox sensitive Tyr phosphorylation of band 3 and its functions are still partially defined. A role of band 3 oxidation in regulating its own phosphorylation has been previously suggested. The current study provides evidences to support this hypothesis: (i in intact erythrocytes, at 2 mM concentration of GSH, band 3 oxidation, and phosphorylation, Syk translocation to the membrane and Syk phosphorylation responded to the same micromolar concentrations of oxidants showing identical temporal variations; (ii the Cys residues located in the band 3 cytoplasmic domain are 20-fold more reactive than GSH; (iii disulfide linked band 3 cytoplasmic domain docks Syk kinase; (iv protein Tyr phosphatases are poorly inhibited at oxidant concentrations leading to massive band 3 oxidation and phosphorylation. We also observed that hemichromes binding to band 3 determined its irreversible oxidation and phosphorylation, progressive hemolysis, and serine hyperphosphorylation of different cytoskeleton proteins. Syk inhibitor suppressed the phosphorylation of band 3 also preventing serine phosphorylation changes and hemolysis. Our data suggest that band 3 acts as redox sensor regulating its own phosphorylation and that hemichromes leading to the protracted phosphorylation of band 3 may trigger a cascade of events finally leading to hemolysis.

  4. Intercomparison of attenuation correction algorithms for single-polarized X-band radars

    Science.gov (United States)

    Lengfeld, K.; Berenguer, M.; Sempere Torres, D.

    2018-03-01

    Attenuation due to liquid water is one of the largest uncertainties in radar observations. The effects of attenuation are generally inversely proportional to the wavelength, i.e. observations from X-band radars are more affected by attenuation than those from C- or S-band systems. On the other hand, X-band radars can measure precipitation fields in higher temporal and spatial resolution and are more mobile and easier to install due to smaller antennas. A first algorithm for attenuation correction in single-polarized systems was proposed by Hitschfeld and Bordan (1954) (HB), but it gets unstable in case of small errors (e.g. in the radar calibration) and strong attenuation. Therefore, methods have been developed that restrict attenuation correction to keep the algorithm stable, using e.g. surface echoes (for space-borne radars) and mountain returns (for ground radars) as a final value (FV), or adjustment of the radar constant (C) or the coefficient α. In the absence of mountain returns, measurements from C- or S-band radars can be used to constrain the correction. All these methods are based on the statistical relation between reflectivity and specific attenuation. Another way to correct for attenuation in X-band radar observations is to use additional information from less attenuated radar systems, e.g. the ratio between X-band and C- or S-band radar measurements. Lengfeld et al. (2016) proposed such a method based isotonic regression of the ratio between X- and C-band radar observations along the radar beam. This study presents a comparison of the original HB algorithm and three algorithms based on the statistical relation between reflectivity and specific attenuation as well as two methods implementing additional information of C-band radar measurements. Their performance in two precipitation events (one mainly convective and the other one stratiform) shows that a restriction of the HB is necessary to avoid instabilities. A comparison with vertically pointing

  5. Nature of the Kπ = 4+ bands in the Os isotopes

    Science.gov (United States)

    Garrett, P. E.; Phillips, A. A.; Bettermann, L.; Braun, N.; Burke, D. G.; Demand, G. A.; Faestermann, T.; Finlay, P.; Green, K. L.; Hertenberger, R.; Leach, K. G.; Krücken, R.; Schumaker, M. A.; Svensson, C. E.; Wirth, H.-F.; Wong, J.

    2008-05-01

    Levels in 186,188Os have been investigated using the (3He,d) reaction with 30 MeV 3He beams. Absolute level-population cross sections have been determined, and angular distributions measured between 5° and 50°. The 43+ levels are observed to be some of the strongest populated states below 2 MeV excitation energy, and the magnitudes of the 5/2+[402]π+3/2+[402]π configuration extracted are in line with quasiparticle-phonon model predictions which state that the lowest-lying Kπ = 4+ band is predominantly a hexadecapole excitation.

  6. ANALISIS TIPOGRAFI PADA LOGOTYPE BAND FORGOTTEN

    Directory of Open Access Journals (Sweden)

    Atang Riyan Isnandar

    2016-12-01

    Full Text Available Abstrak Forgotten merupakan band asal kota Bandung yang beraliran death metal. Band ini telah memiliki beberapa album yang cukup sukses. Salah satu faktor yang turut berperan penting dalam album-album Forgotten adalah desain sampul album. Sampul album merupakan identitas dan pesan dari musik yang dibawakan oleh Forgotten. Dalam sampul album, terdapat salah satu elemen visual yaitu Tipografi. Salah satu peran tipografi dalam sampul album Forgotten adalah sebagai logotype dari band. Yang menarik, dari lima album yang telah dirilis Forgotten yaitu “Future Syndrome” (1997, “Obsesi Mati” (2000, “Tuhan Telah Mati” (2001, “Tiga Angka Enam” (2003 dan “Laras Perlaya” (2011 adalah tampilan logotype band yang selalu berbeda. Perubahan logotype Forgotten disebabkan oleh beberapa faktor seperti adanya perubahan selera, transformasi musik dan pergantian personil yang dialami oleh band Forgotten. Perubahan ini berakibat pada munculnya kesan visual yang berbeda-beda dari masing-masing logotype di setiap sampul albumnya. Apalagi logotype band dengan genre death metal memiliki kecendrungan yang unik, dekoratif, bahkan sulit untuk dibaca. Oleh karena itu untuk mengetahui kesan visual yang dimunculkan oleh setiap logotype akan dilakukan penelitian dengan pendekatan tipografi. Tujuan dari penelitian ini adalah selain untuk mengetahui perubahan logotype dari kelima sampul album yang telah dirilis oleh Forgotten juga ingin mengetahui kesan visual terhadap tipografi terkait dengan prinsip kejelasan (legibility, keterbacaan (readability dan kemampuannya untuk dilihat pada jarak tertentu (visibility. Kata Kunci: Sampul Album, Tipografi, Logotype, Forgotten Abstract Forgotten is a band from Bandung, the death metal genre. The band has had some fairly successful album. One of important factor in albums Forgotten is the album cover design. The album cover are the identity and the message of the music performed by the Forgotten. In the cover of the album

  7. IDENTIFICATION OF NEODYMIUM IN THE APOGEE H -BAND SPECTRA

    International Nuclear Information System (INIS)

    Hasselquist, Sten; Holtzman, Jon; Chojnowski, Drew; Shetrone, Matthew; Cunha, Katia; Pereira, C. B.; Smith, Verne V.; Lawler, J. E.; Prieto, Carlos Allende; García-Hernández, D. A.; Beers, Timothy C.; Placco, Vinicius M.; Zamora, Olga; Fernández-Trincado, J. G.; Hearty, Fred R.; Majewski, Steven R.; Villanova, Sandro

    2016-01-01

    We present the detection of 10 lines of singly ionized neodymium (Nd ii, Z  = 60) in H -band spectra using observations from the SDSS-III Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. These lines were detected in a metal-poor ([Fe/H] ∼ −1.5), neutron-capture element-enhanced star recently discovered in the APOGEE sample. Using an optical high-resolution spectrum, we derive a Nd abundance for this star using Nd ii lines with precise, laboratory-derived gf values. This optical abundance is used to derive log( gf ) values for the H -band lines. We use these lines to rederive Nd ii abundances for two more metal-rich, s -process enhanced stars observed by APOGEE and find that these lines yield consistent Nd ii abundances, confirming the Nd enhancement of these stars. We explore the region of parameter space in the APOGEE sample over which these lines can be used to measure Nd ii abundances. We find that Nd abundances can be reliably derived for ∼18% of the red giants observed by APOGEE. This will result in ∼50,000 Milky Way stars with Nd ii abundances following the conclusion of APOGEE-2, allowing for studies of neutron-capture element abundance distributions across the entire Milky Way.

  8. IDENTIFICATION OF NEODYMIUM IN THE APOGEE H -BAND SPECTRA

    Energy Technology Data Exchange (ETDEWEB)

    Hasselquist, Sten; Holtzman, Jon; Chojnowski, Drew [New Mexico State University, Las Cruces, NM 88003 (United States); Shetrone, Matthew [University of Texas at Austin, McDonald Observatory, Fort Davis, TX 79734 (United States); Cunha, Katia; Pereira, C. B. [Observatório Nacional/MCTI, Rua Gen. José Cristino, 77, 20921-400, Rio de Janeiro (Brazil); Smith, Verne V. [National Optical Astronomy Observatories, Tucson, AZ 85719 (United States); Lawler, J. E. [University of Wisconsin-Madison, Madison, WI 53706 (United States); Prieto, Carlos Allende; García-Hernández, D. A. [Instituto de Astrofísica de Canarias, E-38205 La Laguna, Tenerife (Spain); Beers, Timothy C.; Placco, Vinicius M.; Zamora, Olga [Department of Physics and JINA Center for the Evolution of the Elements, University of Notre Dame, Notre Dame, IN 46556 (United States); Fernández-Trincado, J. G. [Institut Utinam, CNRS UMR 6213, Université de Franche-Comté, OSU THETA Franche-Comté-Bourgogne, Observatoire de Besançon, BP 1615, F-25010 Besançon Cedex (France); Hearty, Fred R. [Department of Astronomy and Astrophysics, The Pennsylvania State University, 525 Davey Laboratory University Park, PA 16802 (United States); Majewski, Steven R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Villanova, Sandro, E-mail: sten@nmsu.edu, E-mail: shetrone@astro.as.utexas.edu, E-mail: cunha@email.noao.edu, E-mail: vsmith@email.noao.edu, E-mail: holtz@nmsu.edu, E-mail: jelawler@wisc.edu, E-mail: tbeers@nd.edu, E-mail: srm4n@virginia.edu, E-mail: claudio@on.br [Departamento de Astronomia, Casilla 160, Universidad de Concepción (Chile)

    2016-12-10

    We present the detection of 10 lines of singly ionized neodymium (Nd ii, Z  = 60) in H -band spectra using observations from the SDSS-III Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. These lines were detected in a metal-poor ([Fe/H] ∼ −1.5), neutron-capture element-enhanced star recently discovered in the APOGEE sample. Using an optical high-resolution spectrum, we derive a Nd abundance for this star using Nd ii lines with precise, laboratory-derived gf values. This optical abundance is used to derive log( gf ) values for the H -band lines. We use these lines to rederive Nd ii abundances for two more metal-rich, s -process enhanced stars observed by APOGEE and find that these lines yield consistent Nd ii abundances, confirming the Nd enhancement of these stars. We explore the region of parameter space in the APOGEE sample over which these lines can be used to measure Nd ii abundances. We find that Nd abundances can be reliably derived for ∼18% of the red giants observed by APOGEE. This will result in ∼50,000 Milky Way stars with Nd ii abundances following the conclusion of APOGEE-2, allowing for studies of neutron-capture element abundance distributions across the entire Milky Way.

  9. Evidence for octupole softness of the superdeformed shape from band interactions in sup 193,4 Hg

    Energy Technology Data Exchange (ETDEWEB)

    Cullen, D.M.; Riley, M.A.; Alderson, A.; Ali, I.; Fallon, P.; Forsyth, P.D.; Hanna, F.; Mullins, S.M.; Roberts, J.W.; Sharpey-Schafer, J.F.; Twin, P.J. (Liverpool Univ. (UK). Oliver Lodge Lab.); Bengtsson, T. (Lund Inst. of Tech. (Sweden). Dept. of Mathematical Physics); Bentley, M.A.; Bruce, A.M.; Simpson, J. (Science and Engineering Research Council, Daresbury (UK). Daresbury Lab.); Nazarewicz, W. (Liverpool Univ. (UK). Oliver Lodge Lab. Politechnika Warszawska (Poland). Inst. Fizyki); Poynter, R.; Regan, P.; Wadsworth, R. (York Univ. (UK). Dept. of Physics); Satula, W. (Warsaw Univ. (Poland). Inst. Fizyki Teoretycznej); Sletten, G. (Niels Bohr Inst., Roskilde (Denmark). Tandem Accelerator Lab.); Wyss, R. (Manne Siegbahn Inst. of Physics, Stockholm (Sweden))

    1990-12-24

    Three superdeformed (SD) bands have been observed in {sup 194}Hg and four (or five ) SD bands in {sup 193}Hg using the {sup 150}Nd+{sup 48}Ca reaction. All bands except for two in {sup 193}Hg show a steady increase in dynamical moment of inertia J{sup (2)} with rotational frequency. The two exceptional bands form a classical pair of strongly interacting bands. It is suggested that the strong interaction between the bands is caused by a softness to octupole deformation. Evidence is found for the existence of dipole transitions connecting bands of opposite signature in {sup 193}Hg. The strengths of these transitions suggest that they are probably E1 supporting the importance of the role of octupole vibrations. These data suggest the wider importance of octupole softness in enhancing E1 transitions in the SD feeding and decay mechanisms. The spectroscopy of the observed SD bands in {sup 193,4}Hg are discussed in detail and attention is drawn to the 'identical' energies of {gamma}-rays in these isotopes with those in lighter isotopes. The similarities in bands relate to the neutron sub-shell closure for SD nuclei at N=112. (orig.).

  10. Density changes in shear bands of a metallic glass determined by correlative analytical transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Rösner, Harald, E-mail: rosner@uni-muenster.de [Institut für Materialphysik, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster (Germany); Peterlechner, Martin [Institut für Materialphysik, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster (Germany); Kübel, Christian [Karlsruhe Institute of Technology (KIT), Institute of Nanotechnology (INT), Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany); Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), D-76344 Eggenstein-Leopoldshafen (Germany); Schmidt, Vitalij [Institut für Materialphysik, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster (Germany); Wilde, Gerhard [Institut für Materialphysik, Westfälische Wilhelms-Universität Münster, Wilhelm-Klemm-Strasse 10, D-48149 Münster (Germany); Institute of Nanochemistry and Nanobiology, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444 (China)

    2014-07-01

    Density changes between sheared zones and their surrounding amorphous matrix as a result of plastic deformation in a cold-rolled metallic glass (melt-spun Al{sub 88}Y{sub 7}Fe{sub 5}) were determined using high-angle annular dark-field (HAADF) detector intensities supplemented by electron-energy loss spectroscopy (EELS), energy-dispersive X-ray (EDX) and nano-beam diffraction analyses. Sheared zones or shear bands were observed as regions of bright or dark contrast arising from a higher or lower density relative to the matrix. Moreover, abrupt contrast changes from bright to dark and vice versa were found within individual shear bands. We associate the decrease in density mainly with an enhanced free volume in the shear bands and the increase in density with concomitant changes of the mass. This interpretation is further supported by changes in the zero loss and Plasmon signal originating from such sites. The limits of this new approach are discussed. - Highlights: • We describe a novel approach for measuring densities in shear bands of metallic glasses. • The linear relation of the dark-field intensity I/I{sub 0} and the mass thickness ρt was used. • Individual shear bands showed abrupt contrast changes from bright to dark and vice versa. • Density changes ranging from about −10% to +6% were found for such shear bands. • Mixtures of amorphous/medium range ordered domains were found within the shear bands.

  11. Modeling and analysis of renewable energy obligations and technology bandings in the UK electricity market

    International Nuclear Information System (INIS)

    Gürkan, Gül; Langestraat, Romeo

    2014-01-01

    In the UK electricity market, generators are obliged to produce part of their electricity with renewable energy resources in accordance with the Renewable Obligation Order. Since 2009 technology banding has been added, meaning that different technologies are rewarded with a different number of certificates. We analyze these two different renewable obligation policies in a mathematical representation of an electricity market with random availabilities of renewable generation outputs and random electricity demand. We also present another, alternative, banding policy. We provide revenue adequate pricing schemes for the three obligation policies. We carry out a simulation study via sampling. A key finding is that the UK banding policy cannot guarantee that the original obligation target is met, hence potentially resulting in more pollution. Our alternative provides a way to make sure that the target is met while supporting less established technologies, but it comes with a significantly higher consumer price. Furthermore, as an undesirable side effect, we observe that a cost reduction in a technology with a high banding (namely offshore wind) leads to more CO 2 emissions under the UK banding policy and to higher consumer prices under the alternative banding policy. - Highlights: • We model and analyze three renewable obligation policies in a mathematical framework. • We provide revenue adequate pricing schemes for the three policies. • We carry out a simulation study via sampling. • The UK policy cannot guarantee that the original obligation target is met. • Cost reductions can lead to more pollution or higher prices under banding policies

  12. A Ka-Band Celestial Reference Frame with Applications to Deep Space Navigation

    Science.gov (United States)

    Jacobs, Christopher S.; Clark, J. Eric; Garcia-Miro, Cristina; Horiuchi, Shinji; Sotuela, Ioana

    2011-01-01

    The Ka-band radio spectrum is now being used for a wide variety of applications. This paper highlights the use of Ka-band as a frequency for precise deep space navigation based on a set of reference beacons provided by extragalactic quasars which emit broadband noise at Ka-band. This quasar-based celestial reference frame is constructed using X/Ka-band (8.4/32 GHz) from fifty-five 24-hour sessions with the Deep Space Network antennas in California, Australia, and Spain. We report on observations which have detected 464 sources covering the full 24 hours of Right Ascension and declinations down to -45 deg. Comparison of this X/Ka-band frame to the international standard S/X-band (2.3/8.4 GHz) ICRF2 shows wRMS agreement of approximately 200 micro-arcsec in alpha cos(delta) and approximately 300 micro-arcsec in delta. There is evidence for systematic errors at the 100 micro-arcsec level. Known errors include limited SNR, lack of instrumental phase calibration, tropospheric refraction mis-modeling, and limited southern geometry. The motivation for extending the celestial reference frame to frequencies above 8 GHz is to access more compact source morphology for improved frame stability and to support spacecraft navigation for Ka-band based NASA missions.

  13. Tunable band structures of polycrystalline graphene by external and mismatch strains

    Institute of Scientific and Technical Information of China (English)

    Jiang-Tao Wu; Xing-Hua Shi; Yu-Jie Wei

    2012-01-01

    Lacking a band gap largely limits the application of graphene in electronic devices.Previous study shows that grain boundaries (GBs) in polycrystalline graphene can dramatically alter the electrical properties of graphene.Here,we investigate the band structure of polycrystalline graphene tuned by externally imposed strains and intrinsic mismatch strains at the GB by density functional theory (DFT) calculations.We found that graphene with symmetrical GBs typically has zero band gap even with large uniaxial and biaxial strain.However,some particular asymmetrical GBs can open a band gap in graphene and their band structures can be substantially tuned by external strains.A maximum band gap about 0.19 eV was observed in matched-armchair GB (5,5) | (3,7) with a misorientation of θ =13° when the applied uniaxial strain increases to 9%.Although mismatch strain is inevitable in asymmetrical GBs,it has a small influence on the band gap of polycrystalline graphene.

  14. Gamma band oscillations: a key to understanding schizophrenia symptoms and neural circuit abnormalities.

    Science.gov (United States)

    McNally, James M; McCarley, Robert W

    2016-05-01

    We review our current understanding of abnormal γ band oscillations in schizophrenia, their association with symptoms and the underlying cortical circuit abnormality, with a particular focus on the role of fast-spiking parvalbumin gamma-aminobutyric acid (GABA) neurons in the disease state. Clinical electrophysiological studies of schizophrenia patients and pharmacological models of the disorder show an increase in spontaneous γ band activity (not stimulus-evoked) measures. These findings provide a crucial link between preclinical and clinical work examining the role of γ band activity in schizophrenia. MRI-based experiments measuring cortical GABA provides evidence supporting impaired GABAergic neurotransmission in schizophrenia patients, which is correlated with γ band activity level. Several studies suggest that stimulation of the cortical circuitry, directly or via subcortical structures, has the potential to modulate cortical γ activity, and improve cognitive function. Abnormal γ band activity is observed in patients with schizophrenia and disease models in animals, and is suggested to underlie the psychosis and cognitive/perceptual deficits. Convergent evidence from both clinical and preclinical studies suggest the central factor in γ band abnormalities is impaired GABAergic neurotransmission, particularly in a subclass of neurons which express parvalbumin. Rescue of γ band abnormalities presents an intriguing option for therapeutic intervention.

  15. The decay-out of superdeformed bands in the A = 190 region. What have we learned?

    International Nuclear Information System (INIS)

    Lauritsen, T.; Hackman, G.; Khoo, T.L.; Carpenter, M.P.; Janssens, R.V.F.; Ackermann, D.; Ahmad, I.; Blumenthal, D.J.; Lopez-Martens, A.

    1997-01-01

    One-step decay transitions linking the superdeformed (SD) bands 1 and 3 in 194 Hg to yrast levels are discussed. Inter-band transitions between bands 1 and 3 have also been identified. For the first time, the spin, parity and excitation energy have been determined for two SD bands in the same nucleus. The low excitation energy of the excited band supports the view that it is based on an octupole excitation. It is believed that Porter-Thomas fluctuations play a major role in determining the strength of the one-step transitions as suggested by the fact that only one other SD band has been linked in the A = 190 mass region ( 194 Pb) at the present time. When Porter-Thomas fluctuations prevent the observation of one-step or two-step linking transitions, as e.g. in the case of 192 Hg, the analysis of the quasi-continuous part of the decay-out spectrum provides an alternative method for the determination of the excitation energy and spin of an SD band. This method is discussed in detail. (author)

  16. A reconfigurable frequency-selective surface for dual-mode multi-band filtering applications

    Science.gov (United States)

    Majidzadeh, Maryam; Ghobadi, Changiz; Nourinia, Javad

    2017-03-01

    A reconfigurable single-layer frequency-selective surface (FSS) with dual-mode multi-band modes of operation is presented. The proposed structure is printed on a compact 10 × 10 mm2 FR4 substrate with the thickness of 1.6 mm. A simple square loop is printed on the front side while another one along with two defected vertical arms is deployed on the backside. To realise the reconfiguration, two pin diodes are embedded on the backside square loop. Suitable insertion of conductive elements along with pin diodes yields in dual-mode multi-band rejection of applicable in service frequency ranges. The first operating mode due to diodes' 'ON' state provides rejection of 2.4 GHz WLAN in 2-3 GHz, 5.2/5.8 GHz WLAN and X band in 5-12 GHz, and a part of Ku band in 13.9-16 GHz. In diodes 'OFF' state, the FSS blocks WLAN in 4-7.3 GHz, X band in 8-12.7 GHz as well as part of Ku band in 13.7-16.7 GHz. As well, high attenuation of incident waves is observed by a high shielding effectiveness (SE) in the blocked frequency bands. Also, a stable behaviour against different polarisations and angles of incidence is obtained. Comprehensive studies are conducted on a fabricated prototype to assess its performance from which encouraging results are obtained.

  17. Band structure and orbital character of monolayer MoS2 with eleven-band tight-binding model

    Science.gov (United States)

    Shahriari, Majid; Ghalambor Dezfuli, Abdolmohammad; Sabaeian, Mohammad

    2018-02-01

    In this paper, based on a tight-binding (TB) model, first we present the calculations of eigenvalues as band structure and then present the eigenvectors as probability amplitude for finding electron in atomic orbitals for monolayer MoS2 in the first Brillouin zone. In these calculations we are considering hopping processes between the nearest-neighbor Mo-S, the next nearest-neighbor in-plan Mo-Mo, and the next nearest-neighbor in-plan and out-of-plan S-S atoms in a three-atom based unit cell of two-dimensional rhombic MoS2. The hopping integrals have been solved in terms of Slater-Koster and crystal field parameters. These parameters are calculated by comparing TB model with the density function theory (DFT) in the high-symmetry k-points (i.e. the K- and Γ-points). In our TB model all the 4d Mo orbitals and the 3p S orbitals are considered and detailed analysis of the orbital character of each energy level at the main high-symmetry points of the Brillouin zone is described. In comparison with DFT calculations, our results of TB model show a very good agreement for bands near the Fermi level. However for other bands which are far from the Fermi level, some discrepancies between our TB model and DFT calculations are observed. Upon the accuracy of Slater-Koster and crystal field parameters, on the contrary of DFT, our model provide enough accuracy to calculate all allowed transitions between energy bands that are very crucial for investigating the linear and nonlinear optical properties of monolayer MoS2.

  18. 47 CFR 15.715 - TV bands database administrator.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database administrator. 15.715 Section... Band Devices § 15.715 TV bands database administrator. The Commission will designate one or more entities to administer a TV bands database. Each database administrator shall: (a) Maintain a database that...

  19. New Kronig-Penney Equation Emphasizing the Band Edge Conditions

    Science.gov (United States)

    Szmulowicz, Frank

    2008-01-01

    The Kronig-Penney problem is a textbook example for discussing band dispersions and band gap formation in periodic layered media. For example, in photonic crystals, the behaviour of bands next to the band edges is important for further discussions of such effects as inhibited light emission, slow light and negative index of refraction. However,…

  20. 47 CFR 15.714 - TV bands database administration fees.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database administration fees. 15.714... Television Band Devices § 15.714 TV bands database administration fees. (a) A TV bands database administrator may charge a fee for provision of lists of available channels to fixed and personal/portable TVBDs and...

  1. 47 CFR 15.713 - TV bands database.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false TV bands database. 15.713 Section 15.713... TV bands database. (a) Purpose. The TV bands database serves the following functions: (1) To... databases. (b) Information in the TV bands database. (1) Facilities already recorded in Commission databases...

  2. Bands and chromosome arrangement in interphase nuclei

    International Nuclear Information System (INIS)

    Bianchi, N.O.; Bianchi, M.A.; Matayoshi, T.

    1977-01-01

    Chromosomes from the vole mouse Akodon dolores and from laboratory mouse showed the presence of G-bands after 3 minutes digestion with trypsin and Giemsa stain. Simultaneously, 30- to 40% of the interphase nuclei exhibited a dark ring parallel to the nuclear contour and a radial array of the chromatin in the internal and external regions of the ring. The origin and meaning of this ring image was analyzed by combining progressive trypsinizations with other methods such as C-banding procedures, autoradiography with 3 HTdR, staining with quinacrine mustard and 33258 Hoechst fluorochromes. Moreover, the presence of the dark ring was also investigated in cells treated with actinomycin and in control cells not subjected to any treatment. The results obtained allowed to assume that in interphase nuclei the chromosomes have chromatin bridges which connect the dark G-bands and that these bridges are probably involved in maintaining an ordered architecture of the nucleus with fixed chromosome positions in regard to the nuclear envelope and in regard to other chromosomes. Trypsinization produces a disruption of the interphase chromatin arrangement and the subsequent appearance of a dark ring formed by the combination of constitutive heterochromatin and dark G-bands. (auth.)

  3. Deformed configurations, band structures and spectroscopic ...

    Indian Academy of Sciences (India)

    2014-03-20

    Mar 20, 2014 ... The deformed configurations and rotational band structures in =50 Ge and Se nuclei are studied by deformed Hartree–Fock with quadrupole constraint and angular momentum projection. Apart from the `almost' spherical HF solution, a well-deformed configuration occurs at low excitation. A deformed ...

  4. Collective states in 230Th: band structure

    Directory of Open Access Journals (Sweden)

    A. I. Levon

    2009-12-01

    Full Text Available Experimental data for the excited states in the deformed nucleus 230Th studied in the (p, t reaction are analyzed. Sequences of the states are selected which can be treated as rotational bands and as multiplets of excitations. Experimental data are compared with the interacting boson model (IBM and the quasiparticle-phonon model (QPM calculations.

  5. Study on electromagnetic constants of rotational bands

    International Nuclear Information System (INIS)

    Abdurazakov, A.A.; Adib, Yu.Sh.; Karakhodzhaev, A.K.

    1991-01-01

    Values of electromagnetic constant S and rotation bands of odd nuclei with Z=64-70 within the mass number change interval A=153-173 are determined. Values of γ-transition mixing parameter with M1+E2 multipolarity are presented. ρ parameter dependence on mass number A is discussed

  6. Energy bands and gaps near an impurity

    Czech Academy of Sciences Publication Activity Database

    Mihóková, Eva; Schulman, L. S.

    2016-01-01

    Roč. 380, č. 41 (2016), s. 3430-3433 ISSN 0375-9601 R&D Projects: GA ČR GA13-09876S Institutional support: RVO:68378271 Keywords : crystal structure * impurity * modeling * energy bands Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.772, year: 2016

  7. Ka-band waveguide rotary joint

    KAUST Repository

    Yevdokymov, Anatoliy; Sirenko, Kostyantyn; Kryzhanovskiy, Volodymyr; Pazynin, Vadim

    2013-01-01

    The authors present a design of a waveguide rotary joint operating in Ka-band with central frequency of 33 GHz, which also acts as an antenna mount. The main unit consists of two flanges with a clearance between them; one of the flanges has three

  8. A Shear Banding Model for Penetration Calculations

    Science.gov (United States)

    2000-04-01

    mechanism of strength reduction to zero within a shear band in three different steels, includ- ing AISI 4340 with RHC 44, which is reasonably similar to RHA...TECH LIB CHINA LAKE CA 93555-6001 CDR NAVAL SUR WAR CTR C S COFFEY PPARK FZERILLI CODE 4140 R K GARRET JR JMCKIRGAN TECH LIB 101 STRAUSS AVE

  9. Electron band theory 1952-1962

    International Nuclear Information System (INIS)

    Lomer, W.M.

    1980-01-01

    Work undertaken by the Theoretical Physics Division between 1952 and 1965 to obtain an understanding of electrons in metals, with uranium and the actinides and the structurally-important transition metals as the main targets is examined. A main result of that period was a conviction that the majority of the physical properties of all metals, except the 4f rare-earth series and the actinides beyond uranium, were dominated by band effects which could be described well enough for most purposes by simple one-electron calculations with simple self-consistent fields. The period from 1960 on showed increasingly clearly the necessity of incorporating relativistic spin-orbit coupling terms in the heavy metals, and some 'local exchange field' correction to the fields close to nuclei. The problems of the non-local interaction of spins - highly important for alloy theory and for antiferromagnetic instability -required the evolution of computers large enough to produce wave-functions at all wave-vectors for all bands so that the susceptibility at arbitrary wave-vector could be computed. This work has not proved to be very illuminating so far, and much interest again focusses today on heuristic arguments that give qualitative descriptions of band structures, such as canonical d-bands to account for crystal structure. (UK)

  10. Phononic band gap structures as optimal designs

    DEFF Research Database (Denmark)

    Jensen, Jakob Søndergaard; Sigmund, Ole

    2003-01-01

    In this paper we use topology optimization to design phononic band gap structures. We consider 2D structures subjected to periodic loading and obtain the distribution of two materials with high contrast in material properties that gives the minimal vibrational response of the structure. Both in...

  11. The end of the unique myocardial band

    DEFF Research Database (Denmark)

    MacIver, David H; Partridge, John B; Agger, Peter

    2018-01-01

    Two of the leading concepts of mural ventricular architecture are the unique myocardial band and the myocardial mesh model. We have described, in an accompanying article published in this journal, how the anatomical, histological and high-resolution computed tomographic studies strongly favour th...

  12. Piecewise planar Möbius bands

    DEFF Research Database (Denmark)

    Gravesen, Jens

    2005-01-01

    t is shown that a closed polygon with an odd number of vertices is the median of exactly one piecewise planar cylinder and one piecewise planar Möbius band, intersecting each other orthogonally. A closed polygon with an even number of vertices is in the generic case neither the median...

  13. PHARUS: A C-band Airborne SAR

    NARCIS (Netherlands)

    Hoogeboom, P.; Koomen, P.J.; Pouwels, H.; Snoeij, P.

    1990-01-01

    In The Netherlands a plan to design aircraft and build a polarimetric C-band SAR system of a novel design, called PHARUS (PHased Array Universal SAR) is carried out by three institutes. These institutes are the Physics and Electronics Laboratory TNO in The Hague (prime contractor and project

  14. Faraday Rotation and L Band Oceanographic Measurements

    DEFF Research Database (Denmark)

    Skou, Niels

    2003-01-01

    Spaceborne radiometric measurements of the L band brightness temperature over the oceans make it possible to estimate sea surface salinity. However, Faraday rotation in the ionosphere disturbs the signals and must be corrected. Two different ways of assessing the disturbance directly from...

  15. Characterization of adiabatic shear bands in the zirconium alloy impacted by split Hopkinson pressure bar at a strain rate of 6000 s−1

    International Nuclear Information System (INIS)

    Zou, D.L.; Luan, B.F.; Liu, Q.; Chai, L.J.; Chen, J.W.

    2012-01-01

    The adiabatic shear bands formed in the zirconium alloy impacted by split Hopkinson pressure bar at a strain rate of about 6000 s −1 were characterized systemically by means of a high resolution field emission scanning electron microscope equipped with electron backscatter diffraction probe. The results show that the transformed bands were distinguished on the cross-section view of the impacted specimens, and the ultrafine and equiaxed grains formed in the transformed bands were confirmed. The gradient variation of the grains across the transformed bands from the boundary to the center of the bands was observed, and the grains at the center of the transformed bands were finer than other zones. Based on the characterization of the deformed microstructure adjacent to the transformed bands, the formation mechanism of the ultrafine and equiaxed grains in the transformed bands was revealed, and the rotational dynamic recrystallization mechanism should be responsible for the formation of the ultrafine and equiaxed grains in the transformed bands. According to the collection of the cumulative misorientation at different strain levels, the formation and evolution process of the ultrafine and equiaxed grains in the transformed bands were speculated. The microhardness measurements show that high microhardness value in the transformed bands was obtained because of the grain refining, and the large standard deviation of the microhardness at the center of the transformed bands was confirmed due to the gradient microstructural distribution in the bands.

  16. Observing nebulae

    CERN Document Server

    Griffiths, Martin

    2016-01-01

    This book enables anyone with suitable instruments to undertake an examination of nebulae and see or photograph them in detail. Nebulae, ethereal clouds of gas and dust, are among the most beautiful objects to view in the night sky. These star-forming regions are a common target for observers and photographers. Griffiths describes many of the brightest and best nebulae and includes some challenges for the more experienced observer. Readers learn the many interesting astrophysical properties of these clouds, which are an important subject of study in astronomy and astrobiology. Non-mathematical in approach, the text is easily accessible to anyone with an interest in the subject. A special feature is the inclusion of an observational guide to 70 objects personally observed or imaged by the author. The guide also includes photographs of each object for ease of identification along with their celestial coordinates, magnitudes and other pertinent information. Observing Nebulae provides a ready resource to allow an...

  17. Oblate L = 1 bands in 194,196-201Pb, and 193Hg

    International Nuclear Information System (INIS)

    Becker, J.A.; Kuhnert, A.; Stoyer, M.A.; Brinkman, M.J.; Wang, T.F.; Roy, N.; Cizewski, J.A.; Stephens, F.S.; Deleplanque, M.A.; Diamond, R.M.; Azaiez, F.; Macchiavelli, A.O.; Korten, W.; Draper, J.E.; California Univ., Berkeley, CA

    1992-11-01

    Reports of recent experiments have included observations of regular and irregular bands in neutron deficient Pb isotopes with A=194, 196--201. The bands are populated strongly in HI,xn reactions. The shared characteristics of the bands include: (1) Bandhead energies of few MeV; (2) High bandhead spin; (3) Large alignments; (4) Small dynamic moments of inertia, and (5) Strong L = 1 transitions and weaker L = 2 crossover transitions, with B(Ml/B(E2)) ∼ 20 μ 2 /e 2 b 2 . Lifetimes of band members in the 198 Pb regular band are B(Ml) ∼ 1 W.u., and B(E2) ∼ 10 W.u. (with large errors). These observations are consistent with an interpretation of the regular structures as collective oblate bands with both proton and neutron excitations involved; the closed proton shell at Z = 82 is broken, and coupled to v(i l3/2 ) -n excitations. The irregular structures may correspond to triaxial shapes, with similar orbits involved. A similar structure has been also found in 193 Hg

  18. High-spin structure of 121Xe: triaxiality, band termination and signature inversion

    International Nuclear Information System (INIS)

    Timar, J.; Paul, E.S.; Beausang, C.W.; Joyce, M.J.; Sharpey-Schafer, J.F.

    1995-01-01

    High-spin states of the odd-neutron 121 Xe nucleus have been studied with Eurogam using the 96 Zr( 30 Si, 5n) 121 Xe fusion-evaporation reaction. The level scheme has been extended up to a tentative spin of 67/2h at an excitation energy of ∼ 14 MeV. Several new rotational bands have been observed and the previously known bands extended. Two of them lose their regular character at high spins, which may be interpreted as transition from collective behaviour to a regime of noncollective oblate states. The deduced high-spin structure is compared to Woods-Saxon TRS cranking and CSM calculations. Configurations of the bands have been suggested. The νh 1 1/2 band is interpreted as having a triaxial shape. Signature inversion and an unexpectedly large staggering of the B(M1)/B(E2) ratios has been found for one of the bands. Enhanced E1 transitions have been observed between the νd 5/2 and the νh 1 1/2 bands. (orig.)

  19. Projected Shell Model Description of Positive Parity Band of 130Pr Nucleus

    Science.gov (United States)

    Singh, Suram; Kumar, Amit; Singh, Dhanvir; Sharma, Chetan; Bharti, Arun; Bhat, G. H.; Sheikh, J. A.

    2018-02-01

    Theoretical investigation of positive parity yrast band of odd-odd 130Pr nucleus is performed by applying the projected shell model. The present study is undertaken to investigate and verify the very recently observed side band in 130Pr theoretically in terms of quasi-particle (qp) configuration. From the analysis of band diagram, the yrast as well as side band are found to arise from two-qp configuration πh 11/2 ⊗ νh 11/2. The present calculations are viewed to have qualitatively reproduced the known experimental data for yrast states, transition energies, and B( M1) / B( E2) ratios of this nucleus. The recently observed positive parity side band is also reproduced by the present calculations. The energy states of the side band are predicted up to spin 25+, which is far above the known experimental spin of 18+ and this could serve as a motivational factor for future experiments. In addition, the reduced transition probability B( E2) for interband transitions has also been calculated for the first time in projected shell model, which would serve as an encouragement for other research groups in the future.

  20. New high spin states and band termination in 83Y and 84Zr

    International Nuclear Information System (INIS)

    Johnson, T.D.; Aprahamian, A.; Lister, C.J.; Blumenthal, D.J.; Crowell, B.; Chowdhury, P.; Fallon, P.; Machiavelli, A.O.

    1997-01-01

    The gamma decay of high spin yrast states in 83 Y up to I π =59/2 + and 53/2 - have been observed using the reaction 58 Ni( 29 Si,3p) at 110 MeV and the Gammasphere Early Implementation Array. The level scheme has been substantially extended due to the observations of several new transitions in all of the bands. A sequence of transitions feeding into the positive parity yrast band above I π =47/2 + seems to be consistent with a noncollective oblate structure expected at these high spins. A similar cascade is found in the data for 84 Zr. A new forking of the favored negative parity band is found which may be due to neutron alignment polarizing the core to a different shape. This suggests that the open-quotes isomeric close-quote close-quote band in 83 Y, for which one more connecting transition was found, is of a similar nature to other high-K bands found in this region. Lifetime measurements in the unfavored negative parity band are consistent with cranking calculations which predict a nearly oblate shape with a deformation parameter β 2 ∼0.2. A qualitative analysis of line shapes at very high spins suggests the persistence of collectivity in the yrast sequence to the highest excitations seen. copyright 1997 The American Physical Society