WorldWideScience

Sample records for broad band quasi-simultaneous

  1. The GREGOR Broad-Band Imager

    Science.gov (United States)

    von der Lühe, O.; Volkmer, R.; Kentischer, T. J.; Geißler, R.

    2012-11-01

    The design and characteristics of the Broad-Band Imager (BBI) of GREGOR are described. BBI covers the visible spectral range with two cameras simultaneously for a large field and with critical sampling at 390 nm, and it includes a mode for observing the pupil in a Foucault configuration. Samples of first-light observations are shown.

  2. The broad-band radio spectrum of LSI+61303 in outburst

    CERN Document Server

    Zimmermann, L; Massi, M

    2015-01-01

    Aims: Our aim is to explore the broad-band radio continuum spectrum of LSI+61303 during its outbursts by employing the available set of secondary focus receivers of the Effelsberg 100 m telescope. Methods: The clear periodicity of the system LSI+61303 allowed observations to be scheduled covering the large radio outburst in March-April 2012. We observed LSI+61303 on 14 consecutive days at 2.6, 4.85, 8.35, 10.45, 14.3, 23, and 32 GHz with a cadence of about 12 hours followed by two additional observations several days later. Based on these observations we obtained a total of 24 quasi-simultaneous broad-band radio spectra. Results: During onset, the main flare shows an almost flat broad-band spectrum, most prominently seen on March 27, 2012, where - for the first time - a flat spectrum (alpha=0.00+/-0.07, S nu^alpha) is observed up to 32 GHz (9 mm wavelength). The flare decay phase shows superimposed 'sub-flares' with the spectral index oscillating between -0.4 and -0.1 in a quasi-regular fashion. Finally, the ...

  3. Broad-band acoustic hyperbolic metamaterial

    CERN Document Server

    Shen, Chen; Sui, Ni; Wang, Wenqi; Cummer, Steven A; Jing, Yun

    2015-01-01

    Acoustic metamaterials (AMMs) are engineered materials, made from subwavelength structures, that exhibit useful or unusual constitutive properties. There has been intense research interest in AMMs since its first realization in 2000 by Liu et al. A number of functionalities and applications have been proposed and achieved using AMMs. Hyperbolic metamaterials are one of the most important types of metamaterials due to their extreme anisotropy and numerous possible applications, including negative refraction, backward waves, spatial filtering, and subwavelength imaging. Although the importance of acoustic hyperbolic metamaterials (AHMMs) as a tool for achieving full control of acoustic waves is substantial, the realization of a broad-band and truly hyperbolic AMM has not been reported so far. Here, we demonstrate the design and experimental characterization of a broadband AHMM that operates between 1.0 kHz and 2.5 kHz.

  4. Broad-Band Molecular Polarization in White Dwarfs

    Science.gov (United States)

    Berdyugina, S. V.; Berdyugin, A. V.; Piirola, V.; Shapiro, A.

    2007-09-01

    We present novel calculations of broad-band polarization due to the molecular Paschen--Back effect in a strong magnetic field. Based on that, we analyze new spectropolarimetric observations of the cool magnetic helium-rich white dwarf G 99-37 which shows strongly polarized molecular bands in its spectrum. Combining the polarimetric observations with our model calculations for the CH bands at 4300 Å, we deduce a magnetic field of 8 MG on this unique magnetic white dwarf.

  5. Broad Band Photometric Reverberation Mapping of NGC 4395

    CERN Document Server

    Edri, Haim; Chelouche, Doron; Kaspi, Shai; Behar, Ehud

    2012-01-01

    We present results of broad band photometric reverberation mapping (RM) to measure the radius of the broad line region, and subsequently the black hole mass (M$_{\\rm BH}$), in the nearby, low luminosity active galactic nuclei (AGN) NGC 4395. Using the Wise Observatory's 1m telescope equipped with the SDSS g$'$, r$'$ and i$'$ broad band filters, we monitored NGC 4395 for 9 consecutive nights and obtained 3 light curves each with over 250 data points. The g$'$ and r$'$ bands include time variable contributions from H$\\beta$ and H$\\alpha$ (respectively) plus continuum. The i$'$ band is free of broad lines and covers exclusively continuum. We show that by looking for a peak in the difference between the cross-correlation and the auto-correlation functions for all combinations of filters, we can get a reliable estimate of the time lag necessary to compute M$_{\\rm BH}$. We measure the time lag for H$\\alpha$ to be $3.6 \\pm 0.8 $ hours, comparable to previous studies using the line resolved spectroscopic RM method. W...

  6. Broad-band hard X-ray reflectors

    DEFF Research Database (Denmark)

    Joensen, K.D.; Gorenstein, P.; Hoghoj, P.;

    1997-01-01

    Interest in optics for hard X-ray broad-band application is growing. In this paper, we compare the hard X-ray (20-100 keV) reflectivity obtained with an energy-dispersive reflectometer, of a standard commercial gold thin-film with that of a 600 bilayer W/Si X-ray supermirror. The reflectivity of ...

  7. 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...

  8. Broad-Band Spectroscopy of Hercules X-1 with Suzaku

    Science.gov (United States)

    Asami, Fumi; Enoto, Teruaki; Iwakiri, Wataru; Yamada, Shin'ya; Tamagawa, Toru; Mihara, Tatehiro; Nagase, Fumiaki

    2014-01-01

    Hercules X-1 was observed with Suzaku in the main-on state from 2005 to 2010. The 0.4- 100 keV wide-band spectra obtained in four observations showed a broad hump around 4-9 keV in addition to narrow Fe lines at 6.4 and 6.7 keV. The hump was seen in all the four observations regardless of the selection of the continuum models. Thus it is considered a stable and intrinsic spectral feature in Her X-1. The broad hump lacked a sharp structure like an absorption edge. Thus it was represented by two different spectral models: an ionized partial covering or an additional broad line at 6.5 keV. The former required a persistently existing ionized absorber, whose origin was unclear. In the latter case, the Gaussian fitting of the 6.5-keV line needs a large width of sigma = 1.0-1.5 keV and a large equivalent width of 400-900 eV. If the broad line originates from Fe fluorescence of accreting matter, its large width may be explained by the Doppler broadening in the accretion flow. However, the large equivalent width may be inconsistent with a simple accretion geometry.

  9. Broad band invisibility cloak made of normal dielectric multilayer

    CERN Document Server

    Xu, Xiaofei; Xiong, Shuai; Fan, Jinlong; Zhao, Jun-Ming; Jiang, Tian

    2011-01-01

    We present the design, fabrication and performance test of a quasi three-dimensional carpet cloak made of normal dielectric in the microwave regime. Taking advantage of a simple linear coordinate transformation we design a carpet cloak with homogeneous anisotropic medium and then practically realize the device with multilayer of alternating normal dielectric slabs based on the effective medium theory. As a proof-of-concept example, we fabricate the carpet cloak with multilayer of FR4 dielectric slabs with air spacing. The performance of the fabricated design is verified through full-wave numerical simulation and measurement of the far-field scattering electromagnetic waves in a microwave anechoic chamber. Experimental results have demonstrated pronounced cloaking effect in a very broad band from 8 GHz to 18 GHz (whole X and Ku band) due to the low loss, non-dispersive feature of the multilayer dielectric structure.

  10. Broad-band photometric evolution of star clusters

    OpenAIRE

    Girardi, Leo

    2001-01-01

    I briefly introduce a database of models that describe the evolution of star clusters in several broad-band photometric systems. Models are based on the latest Padova stellar evolutionary tracks - now including the alpha-enhanced case and improved AGB models - and a revised library of synthetic spectra from model atmospheres. As of today, we have revised isochrones in Johnson-Cousins-Glass, HST/WFPC2, HST/NICMOS, Thuan-Gunn, and Washington systems. Several other filter sets are included in a ...

  11. Seven broad absorption line quasars with excess broad band absorption near 2250

    CERN Document Server

    Zhang, Shaohua; Jiang, Peng; Zhou, Hongyan; Ma, Jingzhe; Brandt, W N; York, Donald G; Noterdaeme, P; Schneider, Donald P

    2014-01-01

    We report the discovery of excess broad band absorption near 2250 A (EBBA) in the spectra of seven broad absorption line (BAL) quasars. By comparing with the statistical results from the control quasar sample, the significance for the detections are all above the > 4{\\sigma} level, with five above > 5{\\sigma}. The detections have also been verified by several other independent methods. The EBBAs present broader and weaker bumps at smaller wavenumbers than the Milky Way, and similar to the Large Magellanic Cloud. The EBBA bump may be related to the 2175 A bump seen in the Local Group and may be a counterpart of the 2175 A bump under different conditions in the early Universe. Furthermore, five objects in this sample show low-ionization broad absorption lines (LoBALs), such as Mg II and Al III, in addition to the high-ionization broad absorption lines (HiBALs) of C IV and Si IV. The fraction of LoBALs in our sample, ~70%, is surprisingly high compared to that of general BAL quasars, ~10%. Although the origin of...

  12. A prism based magnifying hyperlens with broad-band imaging

    Science.gov (United States)

    Habib, Md. Samiul; Stefani, Alessio; Atakaramians, Shaghik; Fleming, Simon C.; Argyros, Alexander; Kuhlmey, Boris T.

    2017-03-01

    Magnification in metamaterial hyperlenses has been demonstrated using curved geometries or tapered devices, at frequencies ranging from the microwave to the ultraviolet spectrum. One of the main issues of such hyperlenses is the difficulty in manufacturing. In this letter, we numerically and experimentally study a wire medium prism as an imaging device at THz frequencies. We characterize the transmission of the image of two sub-wavelength apertures, observing that our device is capable of resolving the apertures and producing a two-fold magnified image at the output. The hyperlens shows strong frequency dependent artefacts, a priori limiting the use of the device for broad-band imaging. We identify the main source of image aberration as the reflections supported by the wire medium and also show that even the weaker reflections severely affect the imaging quality. In order to correct for the reflections, we devise a filtering technique equivalent to spatially variable time gating so that ultra-broad band imaging is achieved.

  13. Ultra-Broad-Band Optical Parametric Amplifier or Oscillator

    Science.gov (United States)

    Strekalov, Dmitry; Matsko, Andrey; Savchenkov, Anatolly; Maleki, Lute

    2009-01-01

    A concept for an ultra-broad-band optical parametric amplifier or oscillator has emerged as a by-product of a theoretical study in fundamental quantum optics. The study was originally intended to address the question of whether the two-photon temporal correlation function of light [in particular, light produced by spontaneous parametric down conversion (SPDC)] can be considerably narrower than the inverse of the spectral width (bandwidth) of the light. The answer to the question was found to be negative. More specifically, on the basis of the universal integral relations between the quantum two-photon temporal correlation and the classical spectrum of light, it was found that the lower limit of two-photon correlation time is set approximately by the inverse of the bandwidth. The mathematical solution for the minimum two-photon correlation time also provides the minimum relative frequency dispersion of the down-converted light components; in turn, the minimum relative frequency dispersion translates to the maximum bandwidth, which is important for the design of an ultra-broad-band optical parametric oscillator or amplifier. In the study, results of an analysis of the general integral relations were applied in the case of an optically nonlinear, frequency-dispersive crystal in which SPDC produces collinear photons. Equations were found for the crystal orientation and pump wavelength, specific for each parametric-down-converting crystal, that eliminate the relative frequency dispersion of collinear degenerate (equal-frequency) signal and idler components up to the fourth order in the frequency-detuning parameter

  14. Broad-band study with Suzaku of the magnetar class

    CERN Document Server

    Enoto, Teruaki; Makishima, Kazuo; Rea, Nanda; Hurley, Kevein; Shibata, Shinpei

    2010-01-01

    Broad-band (0.8-70 keV) spectra of the persistent X-ray emission from 9 magnetars were obtained with Suzaku, including 3 objects in apparent outburst. The soft X-ray component was detected from all of them, with a typical blackbody temperature of kT ~ 0.5 keV, while the hard-tail component, dominating above ~10 keV, was detected at ~1 mCrab intensity from 7 of them. Therefore, the spectrum composed of a soft emission and a hard-tail component may be considered to be a common property of magnetars, both in their active and quiescent states. Wide-band spectral analyses revealed that the hard-tail component has a 1-60 keV flux, Fh, comparable to or even higher than that carried by the 1-60 keV soft component, Fs. The hardness ratio of these objects, defined as xi=Fh/Fs, was found to be tightly anti-correlated with their characteristic age tau as xi=(3.3+/-0.3)x(tau/1 kyr)^(-0.67+/-0.04) with a correlation coefficient of -0.989, over the range from xi~10 to xi~0.1. Magnetars in outburst states were found to lie o...

  15. Broadening of effective photonic band gaps in biological chiral structures: From intrinsic narrow band gaps to broad band reflection spectra

    Science.gov (United States)

    Vargas, W. E.; Hernández-Jiménez, M.; Libby, E.; Azofeifa, D. E.; Solis, Á.; Barboza-Aguilar, C.

    2015-09-01

    Under normal illumination with non-polarized light, reflection spectra of the cuticle of golden-like and red Chrysina aurigans scarabs show a structured broad band of left-handed circularly polarized light. The polarization of the reflected light is attributed to a Bouligand-type left-handed chiral structure found through the scarab's cuticle. By considering these twisted structures as one-dimensional photonic crystals, a novel approach is developed from the dispersion relation of circularly polarized electromagnetic waves traveling through chiral media, to show how the broad band characterizing these spectra arises from an intrinsic narrow photonic band gap whose spectral position moves through visible and near-infrared wavelengths.

  16. Gap-bridging During Quasi-simultaneous Laser Transmission Welding

    Science.gov (United States)

    Schmailzl, Anton; Hierl, Stefan; Schmidt, Michael

    Tightness is often the main requirement for quasi-simultaneous laser transmission welds. However, remaining gaps cannot be detected by the used set-path monitoring. By using a pyrometer in combination with a 3D-scanner, weld seam interruptions can be localized precisely while welding, due to temperature deviations along the weld contour. To analyze the temperature signal in correlation to the progress of gap-bridging, T-joint samples with predefined gaps are welded. The set-path is measured synchronously. Additionally, the temperature distribution and the influence of the thermal expansion of the polymers are studied by a thermo-mechanical FEM-process simulation. On top of that, the melt blow-out of the welded samples is analyzed using μCT-measurements. The experiments have shown that closing of a gap can be identified reliably by the temperature signal and that the squeezed melt flow into the gap and the thermal expansion in the gap zone accelerates gap-bridging. Furthermore the inserted heat can be adapted in the fault zone, in order to avoid thermal damage.

  17. The characteristic of power flow in broad band dynamic vibration absorber

    Institute of Scientific and Technical Information of China (English)

    WANG Minqing; SHENG Meiping; SUN Jincai; LIU Yi

    2002-01-01

    DVA (dynamic vibration absorber) is good for restrain of the resonance vibration in low frequency, especially under the condition that there are only one mode or two modes in a frequency band. It seems rather difficult to control the resonance vibration of elastic structures in high frequency, since usually there are so many modes in high frequency band. The broad band DVA is brought forward to reduce the resonance vibration of elastic structures. The broad band DVA is designed on the basis of the characteristic of power flow in structure in this paper.The broad band DVA is effective on absorbing the resonance vibration power flow of the mostimportant modes. The ability of absorbing vibration for the broad band DVA is analyzed indetail. The results obtained in this paper provide a basis for the optimization design of thebroad band DVA and the optimization positions on structures.

  18. Free space optical networks for ultra-broad band services

    CERN Document Server

    Kartalopoulos, Stamatios V

    2011-01-01

    "Free Space Optical Network is a next generation communication network which uses optical waves instead of microwaves, potentially offering faster communication with ultra band width, meaning more complex communication services can be simultaneously offered. This book describes the network concepts in simple language starting with point-to-point free space optics basics and discusses networking, interoperability with existing communication network, and security. An ideal resource for communication professionals just entering the free space optical communication field and graduate students majoring in optical communications"--Provided by publisher.

  19. Parallel Processing of Broad-Band PPM Signals

    Science.gov (United States)

    Gray, Andrew; Kang, Edward; Lay, Norman; Vilnrotter, Victor; Srinivasan, Meera; Lee, Clement

    2010-01-01

    A parallel-processing algorithm and a hardware architecture to implement the algorithm have been devised for timeslot synchronization in the reception of pulse-position-modulated (PPM) optical or radio signals. As in the cases of some prior algorithms and architectures for parallel, discrete-time, digital processing of signals other than PPM, an incoming broadband signal is divided into multiple parallel narrower-band signals by means of sub-sampling and filtering. The number of parallel streams is chosen so that the frequency content of the narrower-band signals is low enough to enable processing by relatively-low speed complementary metal oxide semiconductor (CMOS) electronic circuitry. The algorithm and architecture are intended to satisfy requirements for time-varying time-slot synchronization and post-detection filtering, with correction of timing errors independent of estimation of timing errors. They are also intended to afford flexibility for dynamic reconfiguration and upgrading. The architecture is implemented in a reconfigurable CMOS processor in the form of a field-programmable gate array. The algorithm and its hardware implementation incorporate three separate time-varying filter banks for three distinct functions: correction of sub-sample timing errors, post-detection filtering, and post-detection estimation of timing errors. The design of the filter bank for correction of timing errors, the method of estimating timing errors, and the design of a feedback-loop filter are governed by a host of parameters, the most critical one, with regard to processing very broadband signals with CMOS hardware, being the number of parallel streams (equivalently, the rate-reduction parameter).

  20. Broad band polarimetric investigation of Type IIP supernova 2013ej

    CERN Document Server

    Kumar, Brajesh; Eswaraiah, C; Kawabata, K S

    2015-01-01

    We present results based on follow-up observations of the Type II-plateau supernova (SN) 2013ej at 6 epochs spanning a total duration of $\\sim$37 d. The $R_{c}$-band linear polarimetric observations were carried out between the end of the plateau and the beginning of the nebular phases as noticed in the photometric light curve. The contribution due to interstellar polarization (ISP) was constrained by using couple of approaches, i.e. based upon the observations of foreground stars lying within 5\\arcmin\\, and 10$\\degr$ radius of the SN location and also investigating the extinction due to the Milky Way and host galaxy towards the SN direction. Our analysis revealed that in general the intrinsic polarization of the SN is higher than the polarization values for the foreground stars and exhibits an increasing trend during our observations. After correcting the ISP of $\\sim$0.6 per cent, the maximum intrinsic polarization of SN~2013ej is found to be 2.14 $\\pm$ 0.57 per cent. Such a strong polarization has rarely b...

  1. System Realization of Broad Band Digital Beam Forming for Digital Array Radar

    Directory of Open Access Journals (Sweden)

    Wang Feng

    2013-09-01

    Full Text Available Broad band Digital Beam Forming (DBF is the key technique for the realization of Digital Array Radar (DAR. We propose the method of combination realization of the channel equalization and DBF time delay filter function by using adaptive Sample Matrix Inversion algorithm. The broad band DBF function is realized on a new DBF module based on parallel fiber optic engines and Field Program Gate Array (FPGA. Good performance is achieved when it is used to some radar products.

  2. Broad-Band Spectral Indices Variability of BL Lacertae by Wavelet Method

    Indian Academy of Sciences (India)

    Hao-Jing Zhang; Jing-Ming Bai; Yu-Ying Bao; Xiong Zhang

    2014-09-01

    BL Lacertae is one of the famous AGN that shows convincing evidence to support periodic variability. We compile R-band data and radio 22 GHz database from the available literature to build the light curves and to calculate broad-band spectral indices. This paper employs the wavelet periodic estimation method. The analysis results indicate that the most possible period is 7.02–7.36 yr in the selected wave-bands. The broad-band spectral indices have a possible period of 4.11 yr as a half value in selected wave-bands. The results confirm that the variability period in the radio 22 GHz is in agreement with the optical R band of about 7.01 yr, as also mentioned in other literatures.

  3. Estimating carbon dioxide fluxes from temperate mountain grasslands using broad-band vegetation indices

    Directory of Open Access Journals (Sweden)

    G. Wohlfahrt

    2010-02-01

    Full Text Available The broad-band normalised difference vegetation index (NDVI and the simple ratio (SR were calculated from measurements of reflectance of photosynthetically active and short-wave radiation at two temperate mountain grasslands in Austria and related to the net ecosystem CO2 exchange (NEE measured concurrently by means of the eddy covariance method. There was no significant statistical difference between the relationships of midday mean NEE with narrow- and broad-band NDVI and SR, measured during and calculated for that same time window, respectively. The skill of broad-band NDVI and SR in predicting CO2 fluxes was higher for metrics dominated by gross photosynthesis and lowest for ecosystem respiration, with NEE in between. A method based on a simple light response model whose parameters were parameterised based on broad-band NDVI allowed to improve predictions of daily NEE and is suggested to hold promise for filling gaps in the NEE time series. Relationships of CO2 flux metrics with broad-band NDVI and SR however generally differed between the two studied grassland sites indicting an influence of additional factors not yet accounted for.

  4. Cavity Enhanced Optical Vernier Spectroscopy, Broad Band, High Resolution, High Sensitivity

    CERN Document Server

    Gohle, Christoph; Schliesser, Albert; Udem, Thomas; Hänsch, Theodor W

    2007-01-01

    A femtosecond frequency comb provides a vast number of equidistantly spaced narrow band laser modes that can be simultaneously tuned and frequency calibrated with 15 digits accuracy. Our Vernier spectrometer utilizes all of theses modes in a massively parallel manner to rapidly record both absorption and dispersion spectra with a sensitivity that is provided by a high finesse broad band optical resonator and a resolution that is only limited by the frequency comb line width while keeping the required setup simple.

  5. Broad Band Spectral Index TeV Blazars Detected by Fermi LAT

    Indian Academy of Sciences (India)

    Yong Juan Cha; Xiong Zhang

    2014-09-01

    We collected the radio, K-band, optical, X-ray, and -ray data for 35 TeV blazars detected by Fermi LAT and studied the possible correlation between different broad band spectral indices (r.o, r.x, ir.o, ir.x, o., x.) in all states (average/high/low). Based on our results, we suggested that the seed photons of the -ray drive from the synchrotron radiation themselves.

  6. W频段宽带倍频器%BROAD-BAND TRIPLER OF W-BAND

    Institute of Scientific and Technical Information of China (English)

    杨涛; 向志军; 吴伟; 杨自强; 钱可伟

    2007-01-01

    A W-band broadband frequency tripler was formed by anti-parallel Schottky-barrier diode pair. The input signal was fed in by a WR-28 waveguide-to-microstrip transition, and the output signal was fed out by a reduced-height WR-10 waveguide. For the input power of 5dBm, the output power was 0.81±1.80dBm and the second harmonic rejection was greater than 25dBc in the whole W-band. This tripler can be used to extend Ka-band signal source to W-band.%介绍了一个W频段宽带倍频器.采用反向并联二极管对结构实现宽带倍频.该倍频器输入为WR-28波导到微带过渡结构,输出为WR-10减高波导.在输入功率为5dBm时,在整个W频段输出功率为0.81±1.80dBm,二次谐波抑制度大于25dBc.该倍频器可把Ka频段的信号源扩展到W频段.

  7. Broad-band transmission spectrum and K-band thermal emission of WASP-43b as observed from the ground

    Science.gov (United States)

    Chen, G.; van Boekel, R.; Wang, H.; Nikolov, N.; Fortney, J. J.; Seemann, U.; Wang, W.; Mancini, L.; Henning, Th.

    2014-03-01

    Aims: WASP-43b is the closest-orbiting hot Jupiter, and it has high bulk density. It causes deep eclipse depths in the system's light curve in both transit and occultation that is attributed to the cool temperature and small radius of its host star. We aim to secure a broad-band transmission spectrum and to detect its near-infrared thermal emission in order to characterize its atmosphere. Methods: We observed one transit and one occultation event simultaneously in the g', r', i', z', J, H, K bands using the GROND instrument on the MPG/ESO 2.2-m telescope, where the telescope was heavily defocused in staring mode. After modeling the light curves, we derived wavelength-dependent transit depths and flux ratios and compared them to atmospheric models. Results: From the transit event, we have independently derived WASP-43's system parameters with high precision and improved the period to be 0.81347437(13) days based on all the available timings. No significant variation in transit depths is detected, with the largest deviations coming from the i'-, H-, and K-bands. Given the observational uncertainties, the broad-band transmission spectrum can be explained by either (i) a flat featureless straight line that indicates thick clouds; (ii) synthetic spectra with absorption signatures of atomic Na/K, or molecular TiO/VO that in turn indicate cloud-free atmosphere; or (iii) a Rayleigh scattering profile that indicates high-altitude hazes. From the occultation event, we detected planetary dayside thermal emission in the K-band with a flux ratio of 0.197 ± 0.042%, which confirms previous detections obtained in the 2.09 μm narrow band and KS-band. The K-band brightness temperature 1878+108-116 K favors an atmosphere with poor day- to nightside heat redistribution. We also have a marginal detection in the i'-band (0.037+0.023-0.021%), corresponding to TB = 2225+139-225 K, which is either a false positive, a signature of non-blackbody radiation at this wavelength, or an

  8. Broad-band transmission spectrum and K-band thermal emission of WASP-43b as observed from the ground

    CERN Document Server

    Chen, Guo; Wang, Hongchi; Nikolov, Nikolay; Fortney, Jonathan J; Seemann, Ulf; Wang, Wei; Mancini, Luigi; Henning, Thomas

    2014-01-01

    (Abridged) We observed one transit and one occultation of the hot Jupiter WASP-43b simultaneously in the g'r'i'z'JHK bands using the GROND instrument on the MPG/ESO 2.2-meter telescope. From the transit event, we have independently derived WASP-43's system parameters with high precision, and improved the period to be 0.81347437(13) days. No significant variation in transit depths is detected, with the largest deviations coming from the i', H, and K bands. Given the observational uncertainties, the broad-band transmission spectrum can be explained by either a flat featureless straight line that indicates thick clouds, synthetic spectra with absorption signatures of atomic Na/K or molecular TiO/VO that indicate cloud-free atmosphere, or a Rayleigh scattering profile that indicates high-altitude hazes. From the occultation event, we have detected planetary dayside thermal emission in the K-band with a flux ratio of 0.197 +/- 0.042%, which confirms previous detections obtained in the 2.09 micron narrow band and K...

  9. Broad-band continuum and line emission of the gamma-ray blazar PKS 0537-441

    CERN Document Server

    Pian, E; Hartman, R C; Maraschi, L; Tavecchio, F; Tornikoski, M; Treves, A; Urry, C M; Ballo, L; Mukherjee, R; Scarpa, R; Thompson, D J; Pesce, J E

    2002-01-01

    PKS 0537-441, a bright gamma-ray emitting blazar, was observed at radio, optical, UV and X-ray frequencies during various EGRET pointings, often quasi-simultaneously. In 1995 the object was found in an intense emission state at all wavelengths. BeppoSAX observations made in 1998, non-simultaneously with exposures at other frequencies, allow us to characterize precisely the spectral shape of the high energy blazar component, which we attribute to inverse Compton scattering. The optical-to-gamma-ray spectral energy distributions at the different epochs show that the gamma-ray luminosity dominates the bolometric output. This, together with the presence of optical and UV line emission, suggests that, besides the synchrotron self-Compton mechanism, the Compton upscattering of photons external to the jet (e.g., in the broad line region) may have a significant role for high energy radiation. The multiwavelength variability can be reproduced by changes of the plasma bulk Lorentz factor. The spectrum secured by IUE in...

  10. Broad-band FT-ICR detection at the Penning trap mass spectrometer TRIGA-TRAP

    Energy Technology Data Exchange (ETDEWEB)

    Knuth, Konstantin; Eibach, Martin; Ketelaer, Jens; Ketter, Jochen; Sturm, Sven [Institut fuer Physik, Universitaet Mainz (Germany); Blaum, Klaus [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Physikalisches Institut, Universitaet Heidelberg Heidelberg (Germany); Block, Michael; Herfurth, Frank [GSI, Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Eberhardt, Klaus [Institut fuer Kernchemie, Universitaet Mainz (Germany); Nagy, Szilard [Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Repp, Julia [Institut fuer Physik, Universitaet Mainz (Germany); Max-Planck-Institut fuer Kernphysik, Heidelberg (Germany); Smorra, Christian [Physikalisches Institut, Universitaet Heidelberg Heidelberg (Germany); Institut fuer Kernchemie, Universitaet Mainz (Germany); Ulmer, Stefan [Institut fuer Physik, Universitaet Mainz (Germany); Physikalisches Institut, Universitaet Heidelberg Heidelberg (Germany)

    2009-07-01

    The double Penning trap mass spectrometer TRIGA-TRAP will perform high-precision mass measurements on exotic neutron-rich nuclides, which are produced via neutron-induced fission of actinide targets at the research reactor TRIGA Mainz. In order to determine which ion species are present in the ion bunch delivered to the Penning trap system, a non-destructive ion detection technique will be implemented in the cylindrical purification trap. This so called broad-band Fourier transform ion cyclotron resonance (FT-ICR) detection technique is based on the detection of image currents, induced by the ions in the trap electrodes. To this end, a new cryogenic low-noise broad-band amplifier is being designed and tested. With this system the identification of contaminations will be possible without the need to eject ions from the trap as usually done at other facilities. The setup as well as its present status are presented.

  11. Broad-Band Visually Evoked Potentials: Re(convolution in Brain-Computer Interfacing.

    Directory of Open Access Journals (Sweden)

    Jordy Thielen

    Full Text Available Brain-Computer Interfaces (BCIs allow users to control devices and communicate by using brain activity only. BCIs based on broad-band visual stimulation can outperform BCIs using other stimulation paradigms. Visual stimulation with pseudo-random bit-sequences evokes specific Broad-Band Visually Evoked Potentials (BBVEPs that can be reliably used in BCI for high-speed communication in speller applications. In this study, we report a novel paradigm for a BBVEP-based BCI that utilizes a generative framework to predict responses to broad-band stimulation sequences. In this study we designed a BBVEP-based BCI using modulated Gold codes to mark cells in a visual speller BCI. We defined a linear generative model that decomposes full responses into overlapping single-flash responses. These single-flash responses are used to predict responses to novel stimulation sequences, which in turn serve as templates for classification. The linear generative model explains on average 50% and up to 66% of the variance of responses to both seen and unseen sequences. In an online experiment, 12 participants tested a 6 × 6 matrix speller BCI. On average, an online accuracy of 86% was reached with trial lengths of 3.21 seconds. This corresponds to an Information Transfer Rate of 48 bits per minute (approximately 9 symbols per minute. This study indicates the potential to model and predict responses to broad-band stimulation. These predicted responses are proven to be well-suited as templates for a BBVEP-based BCI, thereby enabling communication and control by brain activity only.

  12. The range of validity of cluster masses and ages derived from broad-band photometry

    OpenAIRE

    2009-01-01

    I analyze the stochastic effects introduced by the sampling of the stellar initial mass function (SIMF) in the derivation of the individual masses and the cluster mass function (CMF) from broad-band visible-NIR unresolved photometry. The classical method of using unweighted UBV photometry to simultaneously establish ages and extinctions of stellar clusters is found to be unreliable for clusters older than approx. 30 Ma, even for relatively large cluster masses. On the other hand, augmenting t...

  13. Broad band X-ray spectrum of KS 1947+300 with BeppoSAX

    CERN Document Server

    Naik, S; Dotani, T; Paul, B

    2006-01-01

    We present results obtained from three BeppoSAX observations of the accretion-powered transient X-ray pulsar KS 1947+300 carried out during the declining phase of its 2000 November -- 2001 June outburst. A detailed spectral study of KS 1947+300 across a wide X-ray band (0.1--100.0 keV) is attempted for the first time here. Timing analysis of the data clearly shows a 18.7 s pulsation in the X-ray light curves in the above energy band. The pulse profile of KS 1947+300 is characterized by a broad peak with sharp rise followed by a narrow dip. The dip in the pulse profile shows a very strong energy dependence. Broad-band pulse-phase-averaged spectroscopy obtained with three of the BeppoSAX instruments shows that the energy spectrum in the 0.1--100 keV energy band has three components, a Comptonized component, a ~0.6 keV blackbody component, and a narrow and weak iron emission line at 6.7 keV with a low column density of material in the line of sight. We place an upper limit on the equivalent width of the iron K_\\...

  14. Study of LEO-SAT microwave link for broad-band mobile satellite communication system

    Science.gov (United States)

    Fujise, Masayuki; Chujo, Wataru; Chiba, Isamu; Furuhama, Yoji; Kawabata, Kazuaki; Konishi, Yoshihiko

    1993-01-01

    In the field of mobile satellite communications, a system based on low-earth-orbit satellites (LEO-SAT's) such as the Iridium system has been proposed. The LEO-SAT system is able to offer mobile telecommunication services in high-latitude areas. Rain degradation, fading and shadowing are also expected to be decreased when the system is operated at a high elevation angle. Furthermore, the propagation delay generated in the LEO-SAT system is less pronounced than that in the geostationary orbit satellite (GEO-SAT) system and, in voice services, the effect of the delay is almost negligible. We proposed a concept of a broad-band mobile satellite communication system with LEO-SAT's and Optical ISL. In that system, a fixed L-band (1.6/1.5 GHz) multibeam is used to offer narrow band service to the mobile terminals in the entire area covered by a LEO-SAT and steerable Ka-band (30/20 GHz) spot beams are used for the wide band service. In this paper, we present results of a study of LEO-SAT microwave link between a satellite and a mobile terminal for a broad-band mobile satellite communication system. First, the results of link budget calculations are presented and the antennas mounted on satellites are shown. For a future mobile antenna technology, we also show digital beamforming (DBF) techniques. DBF, together with modulation and/or demodulation, is becoming a key technique for mobile antennas with advanced functions such as antenna pattern calibration, correction, and radio interference suppression. In this paper, efficient DBF techniques for transmitting and receiving are presented. Furthermore, an adaptive array antenna system suitable for this LEO-SAT is presented.

  15. Active Noise Control for Narrow-band and Broad-band Signals Using Q-Learning Technique

    Directory of Open Access Journals (Sweden)

    B. Raeisy

    2013-06-01

    Full Text Available The acoustic noise pollution is one of the serious disasters in the current industrialized life. Though traditional solutions based on noise absorption have many different applications, but these methods have low performance for low frequency noises. Active Noise Control (ANC has been introduced to resolve this problem. In this paper, a new active method is introduced for suppressing acoustic noises based on the reinforcement learning. To achieve this, an algorithm to control periodic noises is suggested. Then, the method is developed further to deal with multi-tonal signals with a large number of harmonics. At the next step, the broad-band signals are considered. The problem is broken into some sub-problems in frequency domain and each is solved via a reinforcement learning approach. In all of the proposed techniques no model for the environment is needed. Combining the reinforcement learning and the traditional methods in ANC for broad-band signals is a new line research considered here. This combination could increase the speed of the response, but some information of the dynamics of the environment is needed. This will cause the system to become compatible with gradual changes of the environment. Simulation results show the effectiveness of the proposed approach.

  16. Design of broad-band mixer on V-band%V波段宽带混频器的设计

    Institute of Scientific and Technical Information of China (English)

    宋翔; 年夫顺; 代秀

    2012-01-01

    Because of broad-band mixer's broad working band and low conversion loss,it is often used in communication, radar and microwave measurement systems. In this paper, the design and the performance of a V-band single balance mixer based on fin-line circuit are described. From the theory of the single balance mixer,the design of the single balance mixer-circuit and the structure of waveguide to fin line are expounded. Finally,the conversion loss of this mixer is less than 10 dBm and has a good flatness when the mixer's RF is sweeping from 50~75 GHz.%宽带混频器由于其工作带宽大,变频损耗低,在通信、雷达以及微波毫米波测试仪器等系统得到广泛的应用.介绍了一种V波段鳍线单平衡混频器的设计过程并给出了测试结果.从单平衡混频器的基本原理出发,阐述了鳍线单平衡混频电路和矩形波导到鳍线的过渡结构的设计.最后制作出的宽带混频器在射频频率为50~75 GHz的整个V波段内,变频损耗小于10 dBm,并有良好的变频损耗平坦度.

  17. Ultra-broad band and dual-band highly efficient polarization conversion based on the three-layered chiral structure

    Science.gov (United States)

    Xu, Kai-kai; Xiao, Zhong-yin; Tang, Jing-yao; Liu, De-jun; Wang, Zi-hua

    2016-07-01

    In the paper, a novel three-layered chiral structure is proposed and investigated, which consists of a split-ring resonator sandwiched between two layers of sub-wavelength gratings. This designed structure can achieve simultaneously asymmetric transmission with an extremely broad bandwidth and high amplitude as well as multi-band 90° polarization rotator with very low dispersion. Numerical simulations adopted two kinds of softwares with different algorithms demonstrate that asymmetric parameter can reach a maximum of 0.99 and over than 0.8 from 4.6 to 16.8 GHz, which exhibit magnitude and bandwidth improvement over previous chiral metamaterials in microwave bands (S, C, X and Ku bands). Specifically, the reason of high amplitude is analyzed in detail based on the Fabry-perot like resonance. Subsequently, the highly efficient polarization conversion with very low dispersion between two orthogonal linearly polarized waves is also analyzed by the optical activity and ellipticity. Finally, the electric fields are also investigated and further demonstrate the correctness of the simulated and calculated results.

  18. Unveiling the broad band X-ray continuum and iron line complex in Mkr 841

    CERN Document Server

    Petrucci, P O; Matt, G; Longinotti, A L; Malzac, J; Mouchet, M; Boisson, C; Maraschi, L; Nandra, K; Ferrando, P

    2007-01-01

    Mkr 841 is a bright Seyfert 1 galaxy known to harbor a strong soft excess and a variable K$\\alpha$ iron line. It has been observed during 3 different periods by XMM for a total cumulated exposure time of $\\sim$108 ks. We present in this paper a broad band spectral analysis of the complete EPIC-pn data sets. We were able to test two different models for the soft excess, a relativistically blurred photoionized reflection (\\r model) and a relativistically smeared ionized absorption (\\a model). The continuum is modeled by a simple cut-off power law and we also add a neutral reflection. These observations reveal the extreme and puzzling spectral and temporal behaviors of the soft excess and iron line. The 0.5-3 keV soft X-ray flux decreases by a factor 3 between 2001 and 2005 and the line shape appears to be a mixture of broad and narrow components. We succeed in describing this complex broad-band 0.5-10 keV spectral variability using either \\r or \\a to fit the soft excess. Both models give statistically equivalen...

  19. Broad-band near-field ground motion simulations in 3-dimensional scattering media

    KAUST Repository

    Imperatori, W.

    2012-12-06

    The heterogeneous nature of Earth\\'s crust is manifested in the scattering of propagating seismic waves. In recent years, different techniques have been developed to include such phenomenon in broad-band ground-motion calculations, either considering scattering as a semi-stochastic or purely stochastic process. In this study, we simulate broad-band (0–10 Hz) ground motions with a 3-D finite-difference wave propagation solver using several 3-D media characterized by von Karman correlation functions with different correlation lengths and standard deviation values. Our goal is to investigate scattering characteristics and its influence on the seismic wavefield at short and intermediate distances from the source in terms of ground motion parameters. We also examine scattering phenomena, related to the loss of radiation pattern and the directivity breakdown. We first simulate broad-band ground motions for a point-source characterized by a classic ω2 spectrum model. Fault finiteness is then introduced by means of a Haskell-type source model presenting both subshear and super-shear rupture speed. Results indicate that scattering plays an important role in ground motion even at short distances from the source, where source effects are thought to be dominating. In particular, peak ground motion parameters can be affected even at relatively low frequencies, implying that earthquake ground-motion simulations should include scattering also for peak ground velocity (PGV) calculations. At the same time, we find a gradual loss of the source signature in the 2–5 Hz frequency range, together with a distortion of the Mach cones in case of super-shear rupture. For more complex source models and truly heterogeneous Earth, these effects may occur even at lower frequencies. Our simulations suggests that von Karman correlation functions with correlation length between several hundred metres and few kilometres, Hurst exponent around 0.3 and standard deviation in the 5–10 per cent

  20. [Broad excitation band alkaline-earth silicate luminescent materials activated by rare earth and its applications].

    Science.gov (United States)

    Xia, Wei; Lei, Ming-Kai; Luo, Xi-Xian; Xiao, Zhi-Guo

    2008-01-01

    Series of novel broad excitation band phosphors M2 MgSis O7 : Eu, Dy(M = Ca, Sr) were prepared by a high temperature solid-state reaction method. The crystal structure of compound was characterized. And the effects of part substitution of alkaline-earth on crystal structure, photoluminescence spectra and luminescence properties were also investigated. It is found that the excitation band of silicate luminescent materials extend to visible region and they exhibit yellow, green and blue long after-glow luminescence after excited by ultraviolet or visible light. Ca MgSi O7 : Eu, Dy luminescent materials can be excited effectively under the 450-480 nm range and exhibit a strong emission at 536 nm, nicely combining with blue light emitted by InGaN chips to produce white light. This promises the silicate luminescent materials a potential yellow phosphor for white LED.

  1. Broad-band X-ray observations of CIR X-1

    Science.gov (United States)

    Maisack, M.; Staubert, R.; Balucinska-Church, M.; Skinner, G.; Doebereiner, S.; Englhauser, J.; Aref'ev, V. A.; Efremov, V. V.; Sunyaev, R. A.

    1995-08-01

    We present broad-band (2-88 keV) X-ray observations of the X-ray binary Cir X-1 with the TTM and HEXE instruments on board of the Mir space station. The observations were made in January/February 1989. The spectrum is best described by a model with 3 components: a blackbody at low energies, an iron line and a Comptonized hard continuum. The spectrum is variable during our observations; when the Comptonized component becomes harder, the spectrum becomes softer below 15 keV. The high-energy spectrum resembles that of X-ray binary pulsars.

  2. Dual-etalon cavity ring-down frequency-comb spectroscopy with broad band light source

    Science.gov (United States)

    Chandler, David W; Strecker, Kevin E

    2014-04-01

    In an embodiment, a dual-etalon cavity-ring-down frequency-comb spectrometer system is described. A broad band light source is split into two beams. One beam travels through a first etalon and a sample under test, while the other beam travels through a second etalon, and the two beams are recombined onto a single detector. If the free spectral ranges ("FSR") of the two etalons are not identical, the interference pattern at the detector will consist of a series of beat frequencies. By monitoring these beat frequencies, optical frequencies where light is absorbed may be determined.

  3. Broad-band polarization in molecular spectra. [Zeeman effect in magnetic stars

    Science.gov (United States)

    Illing, R. M. E.

    1981-01-01

    The rotational lines of the CN(0,0) red system have been observed to show a strongly asymmetric Zeeman profile. Certain molecules are very susceptible to magnetic perturbation because of the weakness of their spin-rotation coupling; a fairly weak magnetic field can cause a complete Paschen-Back effect. The calculation of transition probabilities incorporating this effect into the Hamiltonian is discussed, and the detailed calculation is then given. The resulting transition probabilities are transformed into synthetic line profiles by using the Unno (1956) model of polarized radiation transfer. The dependence of the net polarized flux on magnetic field and equivalent width is investigated. It is shown that entire band systems may be significantly polarized. Broad-band circular polarization of sunspots may be due, in part, to molecular bands. Analysis of the CH G band indicates a magnetic field of 0.25-0.50 x 10 to the 6th gauss in the white dwarf G99-37, an order of magnitude lower than previous estimates.

  4. Study of transmission line attenuation in broad band millimeter wave frequency range

    Energy Technology Data Exchange (ETDEWEB)

    Pandya, Hitesh Kumar B. [ITER-India, IPR, Gandhinagar, Gujarat (India); Austin, M. E. [Institute for Fusion Studies, the University of Texas at Austin, Austin, Texas (United States); Ellis, R. F. [Laboratory for Plasma and Fusion Energy Studies, University of Maryland, College Park, Maryland 20742 (United States)

    2013-10-15

    Broad band millimeter wave transmission lines are used in fusion plasma diagnostics such as electron cyclotron emission (ECE), electron cyclotron absorption, reflectometry and interferometry systems. In particular, the ECE diagnostic for ITER will require efficient transmission over an ultra wide band, 100 to 1000 GHz. A circular corrugated waveguide transmission line is a prospective candidate to transmit such wide band with low attenuation. To evaluate this system, experiments of transmission line attenuation were performed and compared with theoretical loss calculations. A millimeter wave Michelson interferometer and a liquid nitrogen black body source are used to perform all the experiments. Atmospheric water vapor lines and continuum absorption within this band are reported. Ohmic attenuation in corrugated waveguide is very low; however, there is Bragg scattering and higher order mode conversion that can cause significant attenuation in this transmission line. The attenuation due to miter bends, gaps, joints, and curvature are estimated. The measured attenuation of 15 m length with seven miter bends and eighteen joints is 1 dB at low frequency (300 GHz) and 10 dB at high frequency (900 GHz), respectively.

  5. Suzaku broad band observations of the Seyfert 1 galaxies Mrk 509 and Mrk 841

    CERN Document Server

    Cerruti, M; Boisson, C; Costantini, E; Longinotti, A L; Matt, G; Mouchet, M; Petrucci, P O

    2011-01-01

    We report an analysis and modelling of new Suzaku observations of the Seyfert 1 galaxies Mrk509 and Mrk841, taken between April and November 2006, for Mrk509, and January and July 2007, for Mrk841, for a total exposure time of ~100 ks each. Data from XIS and HXD/PIN instruments, going from 0.5 to 60 keV, represent the best resolution simultaneous broad band X-ray spectrum for these objects. We fitted the broad band spectrum of both sources with a double Comptonisation model, adding a neutral reflection from distant material and a two-phase warm absorber. We then studied the two competitive models aimed to explain the soft excess with atomic processes: a blurred ionised disc reflection and an ionised absorption by a high velocity material. When fitting the data in the 3-10 keV range with a power law spectrum, and extrapolating this result to low energies, a soft excess is clearly observed below 2 keV: its strength is however weak compared to past observations of both sources. A moderate hard excess is seen at ...

  6. A Successful Broad-band Survey for Giant Lya Nebulae II: Spectroscopic Confirmation

    CERN Document Server

    Prescott, Moire K M; Jannuzi, Buell T

    2012-01-01

    Using a systematic broad-band search technique, we have carried out a survey for large Lya nebulae (or Lya "blobs") at 2broad-band imaging to search for the bright e...

  7. Efficient photon extraction from a quantum dot in a broad-band planar cavity antenna

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Yong, E-mail: y.ma@hw.ac.uk; Kremer, Peter E.; Gerardot, Brian D., E-mail: B.D.Gerardot@hw.ac.uk [Institute of Photonics and Quantum Sciences, SUPA, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

    2014-01-14

    We analyse the extraction of photons emitted from single InAs quantum dots embedded in planar microcavities. The structures are designed to achieve broad-band operation and high-collection efficiency from a device requiring straightforward fabrication, even with electrical contacts. The designs consist of a quantum dot in a GaAs membrane with asymmetric top and bottom mirrors and a top-side solid immersion lens (SIL). Four separate cases are considered in our design: a GaAs membrane only (case 1), GaAs membrane with a glass SIL on top (case 2), a GaAs membrane with a glass SIL on top and a back mirror consisting of Au (case 3), a GaAs membrane with a glass SIL on top of a distribute Bragg reflector mirror and Au back mirror (case 4). Both finite difference time domain and analytical simulations are used to calculate the electric field, power density, and far-field radiation pattern. For optimized structures (case 4), we obtain significant extraction efficiencies (>50%) with modest Purcell enhancements (∼20%) and a large spectral full-width-half-maximum (>100 nm). The high-extraction efficiency, broad-band operation, and facile fabrication make the proposed structures promising for realistic quantum dot devices.

  8. Frequency-dispersive method for improving broad-band SBS phase conjugation of Cr:LiSAF laser

    Institute of Scientific and Technical Information of China (English)

    Chuanwen Ge(葛传文); Weijun Zhang(张为俊)

    2003-01-01

    After passing through four dispersive-prisms, the Q-switched Cr:LiSAF laser with broad frequency band is focused into carbon disulfide (CS2) to produce backward stimulated Brillouin scattering (SBS). Our experimental results and illustrative analysis have shown that this frequency-dispersive method can efficiently reduce the broad-band SBS intensity threshold, compress its pulsewidth, and improve the beam quality.

  9. Mapping the Broad-band Spectrum of a New Candidate Intermediate Mass Black Hole

    Science.gov (United States)

    Farrell, Sean

    2014-10-01

    We request joint XMM-Newton & HST observations of a new intermediate mass black hole candidate in the galaxy LEDA 87326 to map the broad-band spectral energy distribution from X-ray to near-IR. Previous observations with the XMM-Newton EPIC and OM cameras detected an X-ray source with an observed 0.2-10 keV luminosity of 6E41 erg/s, with the X-ray spectrum dominated by a hard power law and the UV/optical data consistent with thermal emission from a cool (~0.08 keV) accretion disc. The high X-ray luminosity and low disc temperature imply a black hole mass > 4000 Msun. By observing this source simultaneously with XMM-Newton and the HST we will confirm that the observed optical emission is from an accretion disc and determine whether any reprocessing in the outer disc is present.

  10. The range of validity of cluster masses and ages derived from broad-band photometry

    CERN Document Server

    Apellániz, J Maíz

    2009-01-01

    I analyze the stochastic effects introduced by the sampling of the stellar initial mass function (SIMF) in the derivation of the individual masses and the cluster mass function (CMF) from broad-band visible-NIR unresolved photometry. The classical method of using unweighted UBV photometry to simultaneously establish ages and extinctions of stellar clusters is found to be unreliable for clusters older than approx. 30 Ma, even for relatively large cluster masses. On the other hand, augmenting the filter set to include longer-wavelength filters and using weights for each filter increases the range of masses and ages that can be accurately measured with unresolved photometry. Nevertheless, a relatively large range of masses and ages is found to be dominated by SIMF sampling effects that render the observed masses useless, even when using UBVRIJHK photometry.

  11. Broad-band time-resolved near infrared spectroscopy in the TJ-II stellarator

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, M.C.; Pastor, I.; Cal, E. de la; McCarthy, K.J. [Laboratorio Nacional de Fusion, CIEMAT, Madrid (Spain); Diaz, D. [Universidad Autonoma de Madrid, Dept Quimica Fisica Aplicada, Madrid (Spain)

    2014-11-15

    First experimental results on broad-band, time-resolved Near Infrared (NIR;here loosely defined as covering from 750 to 1650 nm) passive spectroscopy using a high sensitivity InGaAs detector are reported for the TJ-II Stellarator. Experimental set-up is described together with its main characteristics, the most remarkable ones being its enhanced NIR response, broadband spectrum acquisition in a single shot, and time-resolved measurements with up to 1.8 kHz spectral rate. Prospects for future work and more extended physics studies in this newly open spectral region in TJ-II are discussed. (copyright 2014 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  12. Laser induced broad band anti-Stokes white emission from LiYbF4 nanocrystals

    Institute of Scientific and Technical Information of China (English)

    L. Marciniak; R. Tomala; M. Stefanski; D. Hreniak; W. Strek

    2016-01-01

    Spectroscopic properties of tetragonal LiYbF4 nanocrystals under high dense NIR excitation at vacuum condition were in-vestigated. White, broad band emission covering whole visible part of the spectrum from LiYbF4 nanocrystals was observed. Its in-tensity strongly depended on the excitation power, excitation wavelength and ambient pressure. Temperature of the nanocrystals un-der 975 nm excitation was determined as a function of excitation power. Strong photo-induced current was observed from LiYbF4 pallet. The emission kinetic was analyzed. The mechanism of the anti-Stokes white emission was discussed in terms of the la-ser-induced charge transfer emission from Yb2+ states.

  13. The broad-band X-ray spectrum of Cygnus X-2

    Science.gov (United States)

    Pravdo, S. H.

    1983-01-01

    Cygnus X-2 was observed with the broad-band X-ray spectroscopy experiment, HEAO 1 A-2, in the energy range 0.4-18 keV for four intervals of approximately 31 s over the course of 5 days in 1977. The spectra can be adequately represented by single-temperature thermal bremmstrahlung continua with temperatures ranging from 3.7 x 10 to the 7th K to 6.4 x 10 to the 7th K. An examination of the spectra and the spectra-luminosity relationship effectively rules out one degenerate dwarf model for the X-ray emission. The far-UV continuum emission could be dominated by this continuum component during X-ray high states, an effect which would be detected in optical UV line observations. A Comptonized X-ray cloud around a neutron star remains a viable model for the observed X-ray spectra.

  14. Near-infrared broad-band cavity enhanced absorption spectroscopy using a superluminescent light emitting diode.

    Science.gov (United States)

    Denzer, W; Hamilton, M L; Hancock, G; Islam, M; Langley, C E; Peverall, R; Ritchie, G A D

    2009-11-01

    A fibre coupled near-infrared superluminescent light emitting diode that emits approximately 10 mW of radiation between 1.62 and 1.7 microm is employed in combination with a broad-band cavity enhanced spectrometer consisting of a linear optical cavity with mirrors of reflectivity approximately 99.98% and either a dispersive near-infrared spectrometer or a Fourier transform interferometer. Results are presented on the absorption of 1,3-butadiene, and sensitivities are achieved of 6.1 x 10(-8) cm(-1) using the dispersive spectrometer in combination with phase-sensitive detection, and 1.5 x 10(-8) cm(-1) using the Fourier transform interferometer (expressed as a minimum detectable absorption coefficient) over several minutes of acquisition time.

  15. 11th International Conference On Broad-Band Wireless Computing, Communication and Applications

    CERN Document Server

    Xhafa, Fatos; Yim, Kangbin

    2017-01-01

    The success of all-IP networking and wireless technology has changed the ways of living the people around the world. The progress of electronic integration and wireless communications is going to pave the way to offer people the access to the wireless networks on the fly, based on which all electronic devices will be able to exchange the information with each other in ubiquitous way whenever necessary. The aim of the volume is to provide latest research findings, innovative research results, methods and development techniques from both theoretical and practical perspectives related to the emerging areas of broadband and wireless computing. This proceedings volume presents the results of the 11th International Conference on Broad-Band Wireless Computing, Communication And Applications (BWCCA-2016), held November 5-7, 2016, at Soonchunhyang University, Asan, Korea. .

  16. The range of validity of cluster masses and ages derived from broad-band photometry

    Science.gov (United States)

    Maíz Apellániz, J.

    2010-01-01

    I analyze the stochastic effects introduced by sampling the stellar initial mass function (SIMF) in the derivation of the individual masses and the cluster mass function (CMF) from broad-band visible/near-infrared unresolved photometry. The classical method of using unweighted U BV photometry to simultaneously establish ages and extinctions of stellar clusters is found to be unreliable for clusters older than ≈30 Myr, even for relatively large cluster masses. On the other hand, augmenting the filter set to include longer-wavelength filters and using weights for each filter increases the range of masses and ages that can be measured accurately with unresolved photometry. Nevertheless, a relatively large range of masses and ages is found to be dominated by SIMF sampling effects that render the observed masses useless, even when using U BV RI JHK photometry.

  17. Higher degree moment tensor inversion of Mani earthquake using far-field broad- band recording

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Breakthrough point source model, extended earthquake source model is used to calculate more seismic source parameters in this paper. We express seismic source using higher degree moment tensors, to reduce a large number terms originally presenting in higher degree moment tensor representation, Haskell rupture model is used. We inverted the source parameters of Mani earthquake in Tibet using broad-band body wave of 32 stations of Global Seismograph Network (GSN), the results show that it is a strike-slip fault, rupture direction is 75° , rupture duration is 19 s, the fault plan is f =77° , d =88° , l =0° , the auxiliary plane is f =347° , d =90° , l =178° , and the fault dimension is 47 km′ 28 km. These results will give new quantitative data for earth dynamics and have practical meaning for seismic source tomography research.

  18. Results on the Performance of a Broad Band Focussing Cherenkov Counter

    Science.gov (United States)

    Cester, R.; Fitch, V. L.; Montag, A.; Sherman, S.; Webb, R. C.; Witherell, M. S.

    1980-01-01

    The field of ring imaging (broad band differential) Cherenkov detectors has become a very active area of interest in detector development at several high energy physics laboratories. Our group has previously reported on a method of Cherenkov ring imaging for a counter with large momentum and angular acceptance using standard photo multipliers. Recently, we have applied this technique to the design of a set of Cherenkov counters for use in a particle search experiment at Fermi National Accelerator Laboratory (FNAL). This new detector operates over the range 0.998 a delta..beta.. approx. 2 x 10{sup -4}. The acceptance in angle is +- 14 mrad in the horizontal and +- 28 mrad in the vertical. We report here on the performance of this counter.

  19. The development of silicate matrix phosphors with broad excitation band for phosphor-convered white LED

    Institute of Scientific and Technical Information of China (English)

    LUO XiXian; CAO WangHe; SUN Fei

    2008-01-01

    This paper briefly reviews the recent progress in alkaline earth silicate host luminescent materials with broad excitation band for phosphor-convered white LED. Among them, the Sr-rich binary phases (Sr, Ba, Ca, Mg)2SiO4: Eu2+ and (Sr, Ba, Ca, Mg)3SiO5: Eu2+ are excellent phosphors for blue LED chip white LED. They have very broad excitation bands and exhibit strong absorption of blue radiation in the range of 450-480 nm. And they exhibit green and yellow-orange emission under the InGaN blue LED chip radiation, respectively. The luminous efficiency of InGaN-based (Sr, Ba, Ca, Mg)2SiO4: Eu2+ and (Sr, Ba, Ca, Mg)3SiO5: Eu2+ is about 70-80 lm/W, about 95%-105% that of the InGaN-based YAG:Ce, while the correlated color temperature is between 4600-11000 K. Trinary alkaline earth silicate host luminescent materials MO(M=Sr, Ca, Ba)-Mg(Zn)O-SiO2 show strong absorption of deep blue/near-ultraviolet radia-tion in the range of 370-440 nm. They can convert the deep blue/near-ultraviolet radiation into blue, green, and red emissions to generate white light. The realization of high-performance white-light LEDs by this approach presents excellent chromaticity and high color rendering index, and the application disadvantages caused by the mixture of various matrixes can be avoided. Moreover, the application prospects and the trends of research and development of alkaline earth silicate phosphors are also discussed.

  20. Broad band spectrum of Cygnus X-1 in two spectral states with BeppoSAX

    CERN Document Server

    Frontera, F; Zdziarski, A A; Haardt, F; Perola, G C; Chiappetti, L; Cusumano, G; Dal Fiume, D; Del Sordo, S; Orlandini, M; Parmar, A N; Piro, L; Santangelo, A; Segreto, A; Treves, A; Trifoglio, M

    2000-01-01

    We report on the 0.5--200 keV spectral properties of Cyg X-1 observed at different epochs with the Narrow Field Instruments of the BeppoSAX satellite. The source was in its soft state during the first observation of 1996 June. In the second observation of 1996 September, the source had parameters characteristic to its hard state. A soft X-ray excess, a broad Fe K$\\alpha$ line and Compton reflection are clearly detected in both states. The soft-state broad-band continuum is well modeled by a disk blackbody (accounting for the soft excess) and Compton upscattering of the disk photons by a hybrid, thermal/non-thermal, plasma, probably forming a corona above the disk (also giving rise to the Compton-reflection component). In the hard state, the primary hard X-ray spectrum can be well modeled by Compton upscattering of a weak blackbody emission by a thermal plasma at a temperature of $\\sim 60$ keV. The soft excess is then explained by thermal Comptonization of the same blackbody emission by another hot plasma clou...

  1. A tunable dual-broad-band branch-line coupler utilizing composite right/left-handed transmission lines

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yu; HU Li; HE Sai-ling

    2005-01-01

    A tunable dual-broad-band branch-line coupler (BLC) utilizing composite right/left-handed (CRLH) transmission lines is presented. Two λ/4 segments consisting of CRLH transmission lines are added to each port to broaden the dual bands of the branch-line coupler. Numerical simulation and optimal design of the novel coupler are presented. The dual bands of the novel coupler are tunable and broad. The 1-dB bandwidth of each passband is more than 16% of the central frequency.

  2. Stray light correction and contrast analysis of Hinode broad band images

    CERN Document Server

    Mathew, S K; Solanki, S K

    2009-01-01

    The contrasts of features in the quiet Sun are studied using filtergrams recorded by the Broad-band Filter Imager on the Hinode/Solar Optical Telescope. In a first step, the scattered light originating in the instrument is modeled using Mercury transit data. Combinations of four two-dimensional Gaussians with different widths and weights were employed to retrieve the point-spread functions (PSF) of the instrument at different wavelengths, which also describe instrumental scattered light. The parameters of PSFs at different wavelengths are tabulated. The observed images were then deconvolved using the PSFs. The corrected images were used to obtain contrasts of features such as bright points and granulation in different wavelength bands. After correction, rms contrasts of the granulation of between 0.11 (at 668 nm) and 0.22 (at 388 nm) are obtained. Similarly, bright point contrasts ranging from 0.07 (at 668 nm) to 0.78 (at 388 nm) are found, which are a factor of 1.8 to 2.8 higher than those obtained before PS...

  3. Broad Band X-Ray Observations of the Narrow Line X-Ray Galaxy NGC 5506

    CERN Document Server

    Wang, T G; Otani, C; Matsuoka, M; Awaki, H

    1999-01-01

    We present a detailed analysis of broad band X-ray data of the Seyfert 2 galaxy NGC5506. 2-10 keV band are detected during a 1-day ASCA observation, while no significant change in the 2-10 keV continuum shape is found. The ASCA spectrum consists of an absorbed power-law, a 'soft excess' below 2 keV, and an Fe K$\\alpha$ emission line at 6.4 keV. The 'soft excess' can be well described by either thermal emission from very low abundance material at a temperature kT$\\simeq$0.8 keV, or scattered/leaking flux from the primary power-law plus a small amount of thermal emission. Analysis of ROSAT HRI data reveals that the soft X-ray emission is extended on kpc scales in this object, and the extended component may account for most of the soft X-ray excess observed by the ASCA. The result suggests that in this type 2 AGN, the 'soft excess' at least partly comes from an extended region, imposing serious problem for the model in which the source is partially covered. Fe K$\\alpha$ profile is complex and can not be satisfac...

  4. High sensitivity ultra-broad-band absorption spectroscopy of inductively coupled chlorine plasma

    Science.gov (United States)

    Marinov, Daniil; Foucher, Mickaël; Campbell, Ewen; Brouard, Mark; Chabert, Pascal; Booth, Jean-Paul

    2016-06-01

    We propose a method to measure the densities of vibrationally excited Cl2(v) molecules in levels up to v  =  3 in pure chlorine inductively coupled plasmas (ICPs). The absorption continuum of Cl2 in the 250-450 nm spectral range is deconvoluted into the individual components originating from the different vibrational levels of the ground state, using a set of ab initio absorption cross sections. It is shown that gas heating at constant pressure is the major depletion mechanism of the Cl2 feedstock in the plasma. In these line-integrated absorption measurements, the absorption by the hot (and therefore rarefied) Cl2 gas in the reactor centre is masked by the cooler (and therefore denser) Cl2 near the walls. These radial gradients in temperature and density make it difficult to assess the degree of vibrational excitation in the centre of the reactor. The observed line-averaged vibrational distributions, when analyzed taking into account the radial temperature gradient, suggest that vibrational and translational degrees of freedom in the plasma are close to local equilibrium. This can be explained by efficient vibrational-translational (VT) relaxation between Cl2 and Cl atoms. Besides the Cl2(v) absorption band, a weak continuum absorption is observed at shorter wavelengths, and is attributed to photodetachment of Cl- negative ions. Thus, line-integrated densities of negative ions in chlorine plasmas can be directly measured using broad-band absorption spectroscopy.

  5. Probing the gamma-ray variability in 3C 279 using broad-band observations

    Science.gov (United States)

    Rani, B.; Krichbaum, T. P.; Lee, S.-S.; Sokolovsky, K.; Kang, S.; Byun, D.-Y.; Mosunova, D.; Zensus, J. A.

    2017-01-01

    We present the results of a broad-band radio-to-GeV observing campaign organized to get a better understanding of the radiation processes responsible for the γ-ray flares observed in 3C 279. The total intensity and polarization observations of the source were carried out between 2013 December 28 and 2014 January 03 using the Fermi-Large Area Telescope, Swift-XRT, Swift-UVOT, and Korean VLBI Network telescopes. A prominent flare observed in the optical/near-UV passbands was found to be correlated with a concurrent γ-ray flare at a confidence level >95 per cent, which suggests a co-spatial origin of the two. Moreover, the flaring activity in the two regimes was accompanied by no significant spectral variations. A peak in the X-ray light curve coincides with the peaks of the fractional polarization curves at 43 and 86 GHz radio bands. No prominent variation was noticed for the total intensity and the electric vector position angle observations at radio bands during this period. We noticed a possible hint of steepening of the radio spectrum with an increase in percentage polarization, which suggests that the radio polarization variations could be simply due to a spectral change. In a simple scenario, the correlated optical/γ-ray flares could be caused by the same population of emitting particles. The coincidence of the increase in radio polarization with the X-ray flux supports the picture that X-rays are produced via inverse-Compton scattering of radio photons. The observed fractional variability for the γ-ray flare ˜0.23 does not exceed that in the optical regime, which is inconsistent with what we usually observe for 3C 279; it could be due to different dependencies of the magnetic field and the external radiation field energy density profiles along the jet.

  6. Uncooled ultrasensitive broad-band solution-processed photodetectors (Conference Presentation)

    Science.gov (United States)

    Gong, Xiong

    2016-09-01

    Sensing from the ultraviolet (UV)-visible to infrared (IR) is critical to environmental monitoring and remote sensing, fibre-optic communication, day and night-time surveillance, and emerging medical imaging modalities. Today, separate sensors or materials are required for different sub-bands within the UV to IR wavelength range. In general, AlGaN, Si, InGaAs and PbS based photodetectors (PDs) are used for the four important sub-bands: 0.25 μm-0.4 μm (UV), 0.45 μm-0.8 μm (visible), 0.9 μm-1.7 μm (near IR), 1.5 μm-2.6 μm (middle IR), respectively. To obtain the desired sensitivity, these detectors must be operated at low temperatures (for example, at 4.2 K). Thus, a "breakthrough" technology would be enabled by a new class of PDs -- PDs that do not require cooling to obtain high detectivity; PDs which are fabricated by solution-processing to enable low-cost multi-color, high quantum efficiency, high sensitivity and high speed response over this broad spectral range. The availability of such PDs for use at room temperature (RT) would offer new and important applications. In this presentation, we would like to share with you how we approach RT operated ultrasensitive broad-band solution-processed PDs. - By developing novel low bandgap semiconducting polymers, we are able to develop RT operated solution-processed polymers PDs with spectral response from 350 nm to 1450 nm, the detectivity over 1013 Jones and linear dynamic range over 100 dB; spectral response from 350 nm to 2500 nm, the detectivity over 1012 Jones; - By using low bandgap semiconducting polymers mixed with high electrical conductivity PbS quantum dots (QDs), inverted polymer hybrid PDs with spectral response from 300 nm to 25000 nm, the detectivity over 1013 Jones and linear dynamic range over 100 dB are realized; - By using novel perovskite hybrid materials incorporated with carbon nanotubes, novel n-type newly developed semiconducting polymers, we are able to realize RT operated solution

  7. Properties of Broad Band Continuum of Narrow Line Seyfert 1 Galaxies

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We have performed a statistical study of the properties of the broadband continuum of Narrow Line Seyfert 1 galaxies (NLS1s) by collecting ratio,infrared, optical and X-ray continuum data from various databases and comparedthe results with control samples of Broad Line Seyfert 1 galaxies (BLSls). We findthat the fraction (~ 6%) of Radio Loud (RL) NLSls is significantly less than thatof BLS1s (~ 13%), which is caused by the lack of radio-very-loud sources in theformer. The rarity of RL NLS1s, especially radio-very-loud ones, is consistent withthe scenario of small black hole and high accretion rate for NLSls. Six new radio loudNLSls are found and five RL NLS1 candidates are presented. In comparison withthe BLS1s, the NLS1s tend to have stronger far infrared emission, cooler infraredcolors and redder B- K color, which suggests that NLS1s are hosted by dust-richernuclei. The NLS1s also show steeper soft X-ray spectrum and large soft X-rayto optical flux ratio, while a significant fraction show fiat soft X-ray spectra. Atleast two factors can account for this, absorption and spectral variability. We alsoperform a correlation analysis between various broad band data. It is found thatmost correlations identified for NLS1s are also valid for radio quiet BLS1s: (1) theoptical colors are anti-correlated with X-ray spectral index; (2) higher optical, X-ray and NIR luminosity objects show bluer optical colors and red H - K color; (3)higher luminosity objects show warmer IRAS color; (4) the radio loudness correlateswith B - K and X-ray to optical flux ratio. Radio loud objects behave somewhatdifferently in a few correlations.

  8. Enlarged broad band photodetection using Indium doped TiO{sub 2} alloy thin film

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, Mitra Barun [National Institute of Technology Agartala, Department of Electronics and Communication Engineering, Jirania, Tripura (West) 799055 (India); Mondal, Aniruddha, E-mail: aniruddhamo@gmail.com [National Institute of Technology Agartala, Department of Electronics and Communication Engineering, Jirania, Tripura (West) 799055 (India); Choudhuri, Bijit; Mahajan, Bikram Kishore; Chakrabartty, Shubhro [National Institute of Technology Agartala, Department of Electronics and Communication Engineering, Jirania, Tripura (West) 799055 (India); Ngangbam, Chitralekha [National Institute of Technology Manipur, Department of Electronics and Communication Engineering, Takyelpat, Imphal, Manipur 795001 (India)

    2014-12-05

    Highlights: • An easy technique has been used to dope Indium (instantaneous source) into TiO{sub 2} TF. • An inhomogeneous layer of In{sub x}Ti{sub y}O{sub 2} alloy was formed due to doping. • The lattice constant and optical band gap of TiO{sub 2} has increased after In doping. • Enhanced visible light absorption and detection were recorded for In doped TiO{sub 2} TF. • Almost no delay in photo response for In doped photodetector was observed. - Abstract: An instantaneous source of Indium (In) was used to dope the TiO{sub 2} thin film (TF) on the Si substrate. The X-ray diffraction depicted the presence of rutile phases of TiO{sub 2}, which shifted to the lower value 61.7 from 61.9 (2θ). Secondary ion mass spectrometry (SIMS) reveals that the diffusion of Indium ion yield decreases sharply from the surface, as approached toward the TiO{sub 2} TF–Si substrate interface. The bulk diffusion of In into TiO{sub 2} was observed at a depth of 125–200 nm, up to the edge of TiO{sub 2} TF. An inhomogeneous layer of In{sub x}Ti{sub y}O{sub 2} alloy was formed during annealing process. An average of two fold enhanced photo absorption was recorded for the In doped TiO{sub 2} TF in the 300–350 nm and 450–800 nm regions respectively. The main band gap of In doped TiO{sub 2} was increased to 3.4 eV, whereas the large absorption edge was observed at 3.1 eV. The leakage current (34 nA at −0.5 V) of In doped TiO{sub 2} TF detector was significantly reduced. A maximum 2.5 times (−3.5 V) enlarged photodetection has been observed for In doped TiO{sub 2} TF device under white light illumination. The In doped TiO{sub 2} TF detector shows the broad band photodetection, with an infinitesimal delay in its photo response time as compared to undoped TiO{sub 2} TF.

  9. Basic system design of a broad-band real-time phase contrast wavefront sensor for adaptive optics

    Science.gov (United States)

    Bloemhof, E. E.; Wallace, J. K.

    2005-08-01

    The most common wavefront sensor for real-time use in high-order adaptive optics systems is the Shack-Hartmann, in part because it is sensitive to a broad optical band. An alternative possibility is based on Zernike's phase contrast technique. Though quite sensitive in principle, at least for monochromatic light, there had been no simple way to obtain the broadband performance needed for competitive sensitivity in an actual adaptive optics system. Recently, we proposed a general achromatization scheme that relies upon the innate π/2 phase shift between the transmitted and reflected beams in a beam splitter. Here, a more detailed study of this broad-band phase contrast wavefront sensor is presented, along with some practical issues concerning component tolerances. These results offer encouraging indications that broad-wavelength-band implementations will be feasible in practice.

  10. The impact of JWST broad-band filter choice on photometric redshift estimation

    CERN Document Server

    Bisigello, L; Colina, L; Fèvre, O Le; Nørgaard-Nielsen, H U; Pérez-González, P G; Pye, J; van der Werf, P; Ilbert, O; Grogin, N; Koekemoer, A

    2016-01-01

    The determination of galaxy redshifts in James Webb Space Telescope (JWST)'s blank-field surveys will mostly rely on photometric estimates, based on the data provided by JWST's Near-Infrared Camera (NIRCam) at 0.6-5.0 {\\mu}m and Mid Infrared Instrument (MIRI) at {\\lambda}>5.0 {\\mu}m. In this work we analyse the impact of choosing different combinations of NIRCam and MIRI broad-band filters (F070W to F770W), as well as having ancillary data at {\\lambda}=10, but the zphot quality significantly degrades at S/N<=5. Adding MIRI photometry with one magnitude brighter depth than the NIRCam depth allows for a redshift recovery of 83-99%, depending on SED type, and its effect is particularly noteworthy for galaxies with nebular emission. The vast majority of NIRCam galaxies with [F150W]=29 AB mag at z=7-10 will be detected with MIRI at [F560W, F770W]<28 mag if these sources are at least mildly evolved or have spectra with emission lines boosting the mid-infrared fluxes.

  11. Toward broad-band x-ray detected ferromagnetic resonance in longitudinal geometry

    Energy Technology Data Exchange (ETDEWEB)

    Ollefs, K. [Fakultät für Physik, Universität Duisburg-Essen, Lotharstr. 1, 47057 Duisburg (Germany); European Synchrotron Radiation Facility (ESRF), CS 40220, 38043 Grenoble Cedex (France); Meckenstock, R.; Spoddig, D.; Römer, F. M.; Hassel, Ch.; Schöppner, Ch.; Farle, M. [Fakultät für Physik, Universität Duisburg-Essen, Lotharstr. 1, 47057 Duisburg (Germany); Ney, V.; Ney, A., E-mail: andreas.ney@jku.at [Fakultät für Physik, Universität Duisburg-Essen, Lotharstr. 1, 47057 Duisburg (Germany); Institut für Halbleiter-und Festkörperphysik, Johannes Kepler Universität, Altenberger Str. 69, 4040 Linz (Austria)

    2015-06-14

    An ultrahigh-vacuum-compatible setup for broad-band X-ray detected ferromagnetic resonance (XFMR) in longitudinal geometry is introduced which relies on a low-power, continuous-wave excitation of the ferromagnetic sample. A simultaneous detection of the conventional ferromagnetic resonance via measuring the reflected microwave power and the XFMR signal of the X-ray absorption is possible. First experiments on the Fe and Co L{sub 3}-edges of a permalloy film covered with Co nanostripes as well as the Fe and Ni K-edges of a permalloy film are presented and discussed. Two different XFMR signals are found, one of which is independent of the photon energy and therefore does not provide element-selective information. The other much weaker signal is element-selective, and the dynamic magnetic properties could be detected for Fe and Co separately. The dependence of the latter XFMR signal on the photon helicity of the synchrotron light is found to be distinct from the usual x-ray magnetic circular dichroism effect.

  12. Attenuation structure beneath the volcanic front in northeastern Japan from broad-band seismograms

    Science.gov (United States)

    Takanami, Tetsuo; Selwyn Sacks, I.; Hasegawa, Akira

    2000-10-01

    Anelastic structure in the asthenosphere beneath the volcanic front in northeastern Japan arc is estimated by using the spectral amplitude ratio data of P and S waves from about 100 events which occurred in the subducting Pacific slab below Japan. These earthquakes occurred within a 90 km radius centered about the station Sawauchi (SWU), with focal depths ranging from 60 to 200 km. Waveforms were recorded by the Carnegie broad-band three-component seismograph and were corrected for instrument responses, crustal reverberations, corner frequencies, and superimposed noise. Ray paths and travel times of P and S waves are calculated using a three-dimensional velocity model [Zhao, D., Hasegawa, A., Horiuchi, S., 1992. J. Geophys. Res. 97, 19909-19928]. We find a low- Q region ( QS˜70) extending down to 55 km depth from the lower crust beneath the volcanic front. Using Q-temperature laboratory results [Sato, H., Sacks, I.S., Murase, T., Muncill, G., Fukushima, H., 1989. J. Geophys. Res. 94, 10647-10661], this implies a temperature of about 130°C higher than the eastern forearc region and about 30°C higher than the western backarc region, in good agreement with the tomographic results of Zhao et al. [Zhao, D., Hasegawa, A., Horiuchi, S., 1992. J. Geophys. Res. 97, 19909-19928]. This suggests that low velocities in the crust and uppermost mantle beneath SWU may be explained by a subsolidus temperature increase without partial melting.

  13. [Optimization of broad-band flat-field holographic concave grating without astigmatism].

    Science.gov (United States)

    Kong, Peng; Tang, Yu-guo; Bayanheshig; Li, Wen-hao; Cui, Jin-jiang

    2012-02-01

    The desirable imaging locations of the flat-field holographic concave gratings should be in a plane. And the object can be imaged perfectly by the grating when the tangential focal curve and sagittal focal curve both superpose the intersection of the image plane and dispersion plane. But actually, the defocus can not be eliminated over the entire wavelength range, while the astigmatism vanishes when the grating parameters satisfy some conditions. An optimization method for broad-band flat-field holographic concave gratings with absolute astigmatism correction was proposed. The ray tracing software ZEMAX was used for investigating the imaging properties of the grating. And we made a comparison between spectral performance of gratings designed by this new method and that by conventional method, respectively. The results indicated that the spectral performance of gratings designed by using the absolute astigmatism correction method can be as good as gratings designed with the conventional method. And the focusing performance in the sagittal direction is much better, so that the S/N ratio can be greatly improved.

  14. Synthetic Stellar Photometry. I-General considerations and new transformations for broad-band systems

    CERN Document Server

    Casagrande, Luca

    2014-01-01

    After a pedagogical introduction to the main concepts of synthetic photometry, colours and bolometric corrections in the Johnson-Cousins, 2MASS, and HST-ACS/WFC3 photometric systems are generated from MARCS synthetic fluxes for various [Fe/H] and [alpha/Fe] combinations, and virtually any value of reddening E(B-V) < 0.7. The successes and failures of model fluxes in reproducing the observed magnitudes are highlighted. Overall, extant synthetic fluxes predict quite realistic broad-band colours and bolometric corrections, especially at optical and longer wavelengths: further improvements of the predictions for the blue and ultraviolet spectral regions await the use of hydrodynamic models where the microturbulent velocity is not treated as a free parameter. We show how the morphology of the colour-magnitude diagram (CMD) changes for different values of [Fe/H] and [alpha/Fe]; in particular, how suitable colour combinations can easily discriminate between red giant branch and lower main sequence populations wit...

  15. Multiplexed Volume Bragg Gratings in Narrowand Broad-band Spectral Systems: Analysis and Application

    Science.gov (United States)

    Ingersoll, Gregory B.

    Volume Bragg gratings (VBGs) are important holographic optical elements in many spectral systems. Using multiple volume gratings, whether multiplexed or arranged sequentially, provides advantages to many types of systems in overall efficiency, dispersion performance, flexibility of design, etc. However, the use of multiple gratings---particularly when the gratings are multiplexed in a single holographic optical element (HOE)---is subject to inter-grating coupling effects that ultimately limit system performance. Analyzing these coupling effects requires a more complex mathematical model than the straightforward analysis of a single volume grating. We present a matrix-based algorithm for determining diffraction efficiencies of significant coupled waves in these multiplexed grating holographic optical elements (HOEs). Several carefully constructed experiments with spectrally multiplexed gratings in dichromated gelatin verify our conclusions. Applications of this theory to broad- and narrow-band systems are explored in detailed simulations. Broadband systems include spectrum splitters for diverse-bandgap photovoltaic (PV) cells. Volume Bragg gratings can serve as effective spectrum splitters, but the inherent dispersion of a VBG can be detrimental given a broad-spectrum input. The performance of a holographic spectrum splitter element can be improved by utilizing multiple volume gratings, each operating in a slightly different spectral band. However, care must be taken to avoid inter-grating coupling effects that limit ultimate performance. We explore broadband multi-grating holographic optical elements (HOEs) in sandwiched arrangements where individual single-grating HOEs are placed in series, and in multiplexed arrangements where multiple gratings are recorded in a single HOE. Particle swarm optimization (PSO) is used to tailor these systems to the solar spectrum taking into account both efficiency and dispersion. Both multiplexed and sandwiched two-grating systems

  16. Broad-band spectrophotometry of HAT-P-32 b: search for a scattering signature in the planetary spectrum

    Science.gov (United States)

    Mallonn, M.; Bernt, I.; Herrero, E.; Hoyer, S.; Kirk, J.; Wheatley, P. J.; Seeliger, M.; Mackebrandt, F.; von Essen, C.; Strassmeier, K. G.; Granzer, T.; Künstler, A.; Dhillon, V. S.; Marsh, T. R.; Gaitan, J.

    2016-11-01

    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 previously published light curves for a homogeneous analysis of the broad-band transmission spectrum from the Sloan u' band to the Sloan z' band. Our results rule out cloud-free planetary atmosphere models of solar metallicity. Furthermore, a discrepancy at reddest wavelengths to previously published results 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.

  17. Broad-band spectrophotometry of HAT-P-32 b: Search for a scattering signature in the planetary spectrum

    CERN Document Server

    Mallonn, M; Herrero, E; Hoyer, S; Kirk, J; Wheatley, P J; Seeliger, M; Mackebrandt, F; von Essen, C; Strassmeier, K G; Granzer, T; Künstler, A; Dhillon, V S; Marsh, T R; Gaitan, J

    2016-01-01

    Multi-colour broad-band transit observations offer the opportunity to characterise 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 previously published light curves for a homogeneous analysis of the broad-band transmission spectrum from the Sloan u' band to the Sloan z' band. Our results rule out cloud-free planetary atmosphere models of solar metallicity. Furthermore, a discrepancy at reddest wavelengths to previously published results 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.

  18. Quasi-simultaneous multimodal imaging of cutaneous tissue oxygenation and perfusion

    Science.gov (United States)

    Ren, Wenqi; Gan, Qi; Wu, Qiang; Zhang, Shiwu; Xu, Ronald

    2015-12-01

    Simultaneous and quantitative assessment of multiple tissue parameters may facilitate more effective diagnosis and therapy in many clinical applications, such as wound healing. However, existing wound assessment methods are typically subjective and qualitative, with the need for sequential data acquisition and coregistration between modalities, and lack of reliable standards for performance evaluation or calibration. To overcome these limitations, we developed a multimodal imaging system for quasi-simultaneous assessment of cutaneous tissue oxygenation and perfusion in a quantitative and noninvasive fashion. The system integrated multispectral and laser speckle imaging technologies into one experimental setup. Tissue oxygenation and perfusion were reconstructed by advanced algorithms. The accuracy and reliability of the imaging system were quantitatively validated in calibration experiments and a tissue-simulating phantom test. The experimental results were compared with a commercial oxygenation and perfusion monitor. Dynamic detection of cutaneous tissue oxygenation and perfusion was also demonstrated in vivo by a postocclusion reactive hyperemia procedure in a human subject and a wound healing process in a wounded mouse model. Our in vivo experiments not only validated the performance of the multimodal imaging system for cutaneous tissue oxygenation and perfusion imaging but also demonstrated its technical potential for wound healing assessment in clinical practice.

  19. Design of an Ultra Broad Band YIG-Tuned FET Oscillator Operating within -45~+65℃

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In this paper, the design of an ultra broad band YIG-Tuned FET oscillator is briefly presented. These performances of the superior linearity, the pure spectrum and the ultra broad band tuned oscillation have been realized by a common source circuit topology and a dual coupling YIG resonator. Using a BeO substrate and a buffering amplification stage made up of monolithic MIC traveling wave amplifier, the RF output power has been obtained above 13 dBm in the range from 4 to 16.5 GHz; By means of YIG heater and the temperature compensation of the magnetic circuit, the broad temperature operation performance of YTO has been realized within -45~+65℃.

  20. Large-area broad band saturable Bragg reflectors using oxidized AlAs in the circular and inverted mesa geometries

    Science.gov (United States)

    Nabanja, Sheila P.; Kolodziejski, Leslie A.; Petrich, Gale S.; Sander, Michelle Y.; Morse, Jonathan L.; Shtyrkova, Katia; Ippen, Erich P.; Kärtner, Franz X.

    2013-04-01

    A semiconductor Saturable Bragg Reflector (SBR) is a mirror structure comprising alternating layers of high and low refractive index materials with an incorporated saturable absorber. SBRs can be used to initiate and sustain ultra-short pulses in various laser systems. In order to form ultra-short pulses, SBRs with high reflectivity over a broad wavelength range are required. Furthermore, large-area SBRs facilitate easy integration in a laser cavity. One of the key elements for the realization of broad band SBRs is the development of the thermal oxidation process that creates buried low-index AlxOy layers over large areas. The design, fabrication, characterization, and implementation of broad band, high index contrast III-V/AlxOy SBRs in the form of circular mesas, as well as inverted mesa structures, is presented.

  1. Broad-band Rayleigh wave phase velocity maps (10-150 s) across the United States from ambient noise data

    Science.gov (United States)

    Zhao, Kaifeng; Luo, Yinhe; Xie, Jun

    2017-02-01

    In this study, we demonstrate the feasibility of imaging broad-band (10-150 s) Rayleigh wave phase velocity maps on a continental scale using ambient noise tomography (ANT). We obtain broad-band Rayleigh waves from cross-correlations of ambient noise data between all station pairs of USArray and measure the dispersion curves from these cross-correlations at a period band of 10-150 s. The large-scale dense USArray enables us to obtain over 500 000 surface wave paths which cover the contiguous United States densely. Using these paths, we generate Rayleigh wave phase velocity maps at 10-150 s periods. Our phase velocity maps are similar to other reported phase velocity maps based on ambient noise data at short periods (phase velocity maps from ANT can be used to construct 3-D lithospheric and asthenospheric velocity structures.

  2. 0.8-5.2GHz Broad-Band SiGe-MMIC Quadrature Mixer for Software Defined Radio Receiver

    Science.gov (United States)

    Murakami, Keishi; Suematsu, Noriharu; Tsutsumi, Koji; Kanazawa, Gakushi; Sekine, Tomotsugu; Kubo, Hiroshi; Isota, Yoji

    For the next generation wireless terminals used in the software defined radio (SDR), multi-band / multi-mode transceivers and their MMIC are required which cover the wide RF frequency range from several hundreds MHz up to several GHz. In this paper, 0.8-5.2GHz broad-band SiGe-MMIC quadrature mixer (Q-MIX) for multi-band / multi-mode direct conversion receiver has been developed. By using a static type frequency divider as a 90 degrees local (LO) power divider, measured error vector magnitude (EVM) of less than 3.1% can be achieved in the cases of 0.8/2.1GHz W-CDMA and 5.2GHz wireless Local Area Network (LAN) (IEEE 802.11a) reception. This Q-MIX also shows broad-band characteristic for base-band signal and is applicable for 4G cellular. By using fabricated Q-MIX, a multi-band / multi-mode (1.9GHz (3rd generation cellular (W-CDMA)) / 5.2GHz (4th generation cellular (Multi-Carrier (MC)-CDMA))) receiver has been developed and it has firstly demonstrated the successful reception of motion picture via W-CDMA and MC-CDMA.

  3. Broad-band colours and overall photometric properties of template galaxy models from stellar population synthesis

    Science.gov (United States)

    Buzzoni, Alberto

    2005-08-01

    the observation (and the interpretation) of high-redshift surveys. In addition to broad-band colours, the modelling of Balmer line emission in disc-dominated systems shows that striking emission lines, like Hα, can very effectively track stellar birth rate in a galaxy. For these features to be useful age tracers as well, however, one should first assess the real change of b versus time on the basis of supplementary (and physically independent) arguments.

  4. Analytical Approximation of the Deconvolution of Strongly Overlapping Broad Fluorescence Bands

    Science.gov (United States)

    Dubrovkin, J. M.; Tomin, V. I.; Ushakou, D. V.

    2016-09-01

    A method for deconvoluting strongly overlapping spectral bands into separate components that enables the uniqueness of the deconvolution procedure to be monitored was proposed. An asymmetric polynomial-modified function subjected to Fourier filtering (PMGFS) that allowed more accurate and physically reasonable band shapes to be obtained and also improved significantly the deconvolution convergence was used as the band model. The method was applied to the analysis of complexation in solutions of the molecular probe 4'-(diethylamino)-3-hydroxyflavone with added LiCl. Two-band fluorescence of the probe in such solutions was the result of proton transfer in an excited singlet state and overlapped strongly with stronger spontaneous emission of complexes with the ions. Physically correct deconvolutions of overlapping bands could not always be obtained using available software.

  5. Broad-band modelling of short gamma-ray bursts with energy injection from magnetar spin-down and its implications for radio detectability

    NARCIS (Netherlands)

    B.P. Gompertz; A.J. van der Horst; P.T. O'Brien; G.A. Wynn; K. Wiersema

    2015-01-01

    The magnetar model has been proposed to explain the apparent energy injection in the X-ray light curves of short gamma-ray bursts (SGRBs), but its implications across the full broad-band spectrum are not well explored. We investigate the broad-band modelling of four SGRBs with evidence for energy in

  6. Data Acquisition and Control System for Broad-band Microwave Reflectometry on EAST

    CERN Document Server

    Wen, Fei; Zhang, Shoubiao; Kong, Defeng; Wang, Yuming; Han, Xiang; Qu, Hao; Gao, Xiang

    2014-01-01

    Microwave reflectometry is a non-intrusive plasma diagnostic tool which is widely applied in many fusion devices. In 2014, the microwave reflectometry on Experimental Advanced Superconducting Tokamak (EAST) had been upgraded to measure plasma density profile and fluctuation, which covered the frequency range of Q-band (32-56 GHz), V-band (47-76 GHz) and W-band (71-110 GHz). This paper presented a dedicated data acquisition and control system (DAQC) to meet the measurement requirements of high accuracy and temporal resolution. The DAQC consisted of two control modules, which integrated arbitrary waveform generation block (AWG) and trigger processing block (TP), and two data acquisition modules (DAQ) that was implemented base on the PXIe platform from National Instruments (NI). All the performance parameters had satisfied the requirements of reflectometry. The actual performance will be further examined in the experiments of EAST in 2014.

  7. Multiwavelength observations of the energetic GRB 080810: detailed mapping of the broad-band spectral evolution

    NARCIS (Netherlands)

    Page, K.L.; Willingale, R.; Bissaldi, E.; de Ugarte Postigo, A.; Holland, S.T.; McBreen, S.; O'Brien, P.T.; Osborne, J.P.; Prochaska, J.X.; Rol, E.; Rykoff, E.S.; Starling, R.L.C.; Tanvir, N.R.; van der Horst, A.J.; Wiersema, K.; Zhang, B.; Aceituno, F.J.; Akerlof, C.; Beardmore, A.P.; Briggs, M.S.; Burrows, D.N.; Castro-Tirado, A.J.; Connaughton, V.; Evans, P.A.; Fynbo, J.P.U.; Gehrels, N.; Guidorzi, C.; Howard, A.W.; Kennea, J.A.; Kouveliotou, C.; Pagani, C.; Preece, R.; Perley, D.; Steele, I.A.; Yuan, F.

    2009-01-01

    GRB 080810 was one of the first bursts to trigger both Swift and the Fermi Gamma-ray Space Telescope. It was subsequently monitored over the X-ray and UV/optical bands by Swift, in the optical by Robotic Optical Transient Search Experiment (ROTSE) and a host of other telescopes, and was detected in

  8. Description and Field Evaluation of the Broad-Band Underwater Recording Buoy System

    Science.gov (United States)

    2005-12-01

    expériences de transmission acoustique. Importance des résultats Une nouvelle capacité d’enregistrement acoustique sous-marin large bande a été produite...HMCS Ville de Quebec in Bedford Basin, Nova Scotia. These measurements were severely compromised by the fact that the ship was not able to

  9. Space Telescope and Optical Reverberation Mapping Project. III. Optical Continuum Emission and Broad-Band Time Delays in NGC 5548

    CERN Document Server

    Fausnaugh, M M; Barth, A J; Bentz, M C; Bottorff, M C; Carini, M T; Croxall, K V; De Rosa, G; Goad, M R; Horne, Keith; Joner, M D; Kaspi, S; Kim, M; Klimanov, S A; Kochanek, C S; Leonard, D C; Netzer, H; Peterson, B M; Schnulle, K; Sergeev, S G; Vestergaard, M; Zheng, W -K; Anderson, M D; Arevalo, P; Bazhaw, C; Borman, G A; Boroson, T A; Brandt, W N; Breeveld, A A; Brewer, B J; Cackett, E M; Crenshaw, D M; Bonta, E Dalla; De Lorenzo-Caceres, A; Dietrich, M; Edelson, R; Efimova, N V; Ely, J; Evans, P A; Filippenko, A V; Flatland, K; Gehrels, N; Geier, S; Gelbord, J M; Gonzalez, L; Gorjian, V; Grier, C J; Grupe, D; Hall, P B; Hicks, S; Horenstein, D; Hutchison, T; Im, M; Jensen, J J; Jones, J; Kaastra, J; Kelly, B C; Kennea, J A; Kim, S C; Korista, K T; Kriss, G A; Larionov, V M; Lee, J C; Lira, P; MacInnis, F; Manne-Nicholas, E R; Mathur, S; McHardy, I M; Montouri, C; Musso, R; Nazarov, S V; Norris, R P; Nousek, J A; Okhmat, D N; Pancoast, A; Papadakis, I; Parks, J R; Pei, L; Pogge, R W; Pott, J -U; Rafter, S E; Rix, H -W; Saylor, D A; Schimoia, J S; Siegel, M; Spencer, M; Starkey, D; Sung, H -I; Teems, K G; Treu, T; Turner, C S; Uttley, P; Villforth, C; Weiss, Y; Woo, J -H; Yan, H; Young, S; Zu, Y

    2015-01-01

    We present ground-based optical photometric monitoring data for NGC 5548, part of an extended multi-wavelength reverberation mapping campaign. The light curves have nearly daily cadence from 2014 January to July in nine filters ($BVRI$ and $ugriz$). Combined with UV data from the $Hubble$ $Space$ $Telescope$ and $Swift$, we confirm significant time delays between the continuum bands as a function of wavelength, extending the wavelength coverage from $1158\\,{\\rm \\AA}$ to the $z$-band ($\\sim\\! 9160\\,{\\rm \\AA}$). We find that the lags at wavelengths longer than the $V$ band are equal to or greater than the lags of high ionization-state emission lines (such as HeII$\\lambda 1640$ and $\\lambda 4686$), suggesting that the continuum emitting source is of a physical size comparable to the inner broad line region. The trend of lag with wavelength is broadly consistent with the prediction for continuum reprocessing by an accretion disk with $\\tau \\propto \\lambda^{4/3}$. However, the lags also imply a disk radius that is...

  10. Experimental demonstration of terahertz metamaterial absorbers with a broad and flat high absorption band.

    Science.gov (United States)

    Huang, Li; Chowdhury, Dibakar Roy; Ramani, Suchitra; Reiten, Matthew T; Luo, Sheng-Nian; Taylor, Antoinette J; Chen, Hou-Tong

    2012-01-15

    We present the design, numerical simulations and experimental measurements of terahertz metamaterial absorbers with a broad and flat absorption top over a wide incidence angle range for either transverse electric or transverse magnetic polarization depending on the incident direction. The metamaterial absorber unit cell consists of two sets of structures resonating at different but close frequencies. The overall absorption spectrum is the superposition of individual components and becomes flat at the top over a significant bandwidth. The experimental results are in excellent agreement with numerical simulations.

  11. Effects of broad band electromagnetic fields on HSP70 expression and ischemia-reperfusion in rat hearts.

    Science.gov (United States)

    Ronchi, Raffaella; Marano, Lidia; Braidotti, Paola; Bianciardi, Paola; Calamia, Mario; Fiorentini, Cesare; Samaja, Michele

    2004-09-03

    Although exposure to broad band (0.2-20 MHz) electromagnetic fields (EMF) is part of the treatment of several diseases, little is known as to their effects on myocardial protein expression and resistance to ischemia-reperfusion (I/R). We exposed Sprague-Dawley rats to either high (H, 10 min/day at 200 V/m, 36.1 microT) or low (L, 2 min/day at 30 V/m, 11.4 microT) intensity broad band EMF for 15 days. At the end of the treatment, myocardial HSP70 was 32 +/- 8% (mean +/- SEM) higher in L (P = 0.01) than in control (C), whereas in H it remained the same as in C. Electron microscopy revealed sporadic ruptures of mitochondrial cristae in H hearts, with no differences in other parameters. Malondialdehyde was increased in treated hearts (P < 0.05), but especially in H (P = 0.008). To assess the protective role of HSP70 during I/R, hearts were Langendorff-perfused with Krebs-Henseleit. After I/R, C hearts displayed depressed rate. pressure (-13 +/- 7%) and increased end-diastolic (+9.2 +/- 2.8 mmHg) and perfusion pressures (+30 +/- 10 mmHg). In H and L, rate. pressure recovery was similar to C (-2 +/- 21% and -12 +/- 16%, respectively, P = NS). In contrast, both end-diastolic and perfusion pressures were higher in L than in H (30.8 +/- 5.4 vs 18.2 +/- 3.5, P = 0.01, and 54 +/- 8 vs 21 +/- 8 mmHg, P = 0.01, respectively) indicating diastolic derangement in L. In conclusion, the effects of broad band EMF on HSP70 appear to be biphasic, and HSP70 overexpression might not be directly related to improved protection against I/R.

  12. A compact planar multi-broad band monopole antenna for mobile devices

    Science.gov (United States)

    Zhong, Xiaoqing; Yao, Bin; Zheng, Qinhong; Yang, Jikong; Cao, Xiangqi

    2015-10-01

    A Multiple-frequency broadband planar monopole antenna is proposed in this Paper. The antenna is stimulated and numerically optimized by HFSS13.0 (High Frequency Structure Simulator). The size of it is 39mm×22mm×1.7mm. The antenna resonates at many frequencies. The parameter S11antenna matches well with its feed-line and covers many useful operation frequency bands, including 2G(DCS1800 and PCS1900), 3G(UMTS), 4G(LTE2300 and LTE2500), ISM, WLAN. It is quiet appropriate for the present ultra-thin smart phones

  13. A tunable, linac based, intense, broad-band THz source forpump-probe experiments

    Energy Technology Data Exchange (ETDEWEB)

    Schmerge, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Adolphsen, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Corbett, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Dolgashev, V. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Durr, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Fazio, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Fisher, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Frisch, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Gaffney, K. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Guehr, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hastings, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hettel, B. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hoffmann, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Hogan, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Holtkamp, N. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Huang, X. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Huang, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Kirchmann, P. [SLAC National Accelerator Lab., Menlo Park, CA (United States); LaRue, J. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Limborg, C. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Lindenberg, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Loos, H. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Maxwell, T. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Nilsson, A. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Raubenheimer, T. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Reis, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Ross, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Shen, Z. -X. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Stupakov, G. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Tantawi, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Tian, K. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Wu, Z. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Xiang, D. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Yakimenko, V. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-02-02

    We propose an intense THz source with tunable frequency and bandwidth that can directly interact with the degrees of freedom that determine the properties of materials and thus provides a new tool for controlling and directing these ultrafast processes as well as aiding synthesis of new materials with new functional properties. This THz source will broadly impact our understanding of dynamical processes in matter at the atomic-scale and in real time. Established optical pumping schemes using femtosecond visible frequency laser pulses for excitation are extended into the THz frequency regime thereby enabling resonant excitation of bonds in correlated solid state materials (phonon pumping), to drive low energy electronic excitations, to trigger surface chemistry reactions, and to all-optically bias a material with ultrashort electric fields or magnetic fields. A linac-based THz source can supply stand-alone experiments with peak intensities two orders of magnitude stronger than existing laser-based sources, but when coupled with atomic-scale sensitive femtosecond x-ray probes it opens a new frontier in ultrafast science with broad applications to correlated materials, interfacial and liquid phase chemistry, and materials in extreme conditions.

  14. Interaction Between The Broad-lined Type Ic Supernova 2012ap and Carriers of Diffuse Interstellar Bands

    CERN Document Server

    Milisavljevic, D; Crabtree, K N; Foster, J B; Soderberg, A M; Fesen, R A; Parrent, J T; Sanders, N E; Drout, M R; Kamble, A; Chakraborti, S; Pickering, T E; Cenko, S B; Silverman, J M; Filippenko, A V; Kirshner, R P; Mazzali, P; Maeda, K; Marion, G H; Vinko, J; Wheeler, J C

    2014-01-01

    The diffuse interstellar bands (DIBs) are absorption features observed in optical and near-infrared spectra that are thought to be associated with carbon-rich polyatomic molecules in interstellar gas. However, because the central wavelengths of these bands do not correspond with electronic transitions of any known atomic or molecular species, their nature has remained uncertain since their discovery almost a century ago. Here we report on unusually strong DIBs in optical spectra of the broad-lined Type Ic supernova SN 2012ap that exhibit changes in equivalent width over short (~30 days) timescales. The 4428 and 6283 Angstrom DIB features get weaker with time, whereas the 5780 Angstrom feature shows a marginal increase. These nonuniform changes suggest that the supernova is interacting with a nearby source of the DIBs and that the DIB carriers possess high ionization potentials, such as small cations or charged fullerenes. We conclude that moderate-resolution spectra of supernovae with DIB absorptions obtained...

  15. Multi-cavity coupling acoustic metamaterials with low-frequency broad band gaps based on negative mass density

    Science.gov (United States)

    Yang, Chuanhui; Wu, Jiu Hui; Cao, Songhua; Jing, Li

    2016-08-01

    This paper studies a novel kind of low-frequency broadband acoustic metamaterials with small size based on the mechanisms of negative mass density and multi-cavity coupling. The structure consists of a closed resonant cavity and an open resonant cavity, which can be equivalent to a homogeneous medium with effective negative mass density in a certain frequency range by using the parameter inversion method. The negative mass density makes the anti-resonance area increased, which results in broadened band gaps greatly. Owing to the multi-cavity coupling mechanism, the local resonances of the lower frequency mainly occur in the closed cavity, while the local resonances of the higher frequency mainly in the open cavity. Upon the interaction between the negative mass density and the multi-cavity coupling, there exists two broad band gaps in the range of 0-1800 Hz, i.e. the first-order band gap from 195 Hz to 660 Hz with the bandwidth of 465 Hz and the second-order band gap from 1157 Hz to 1663 Hz with the bandwidth of 506 Hz. The acoustic metamaterials with small size presented in this paper could provide a new approach to reduce the low-frequency broadband noises.

  16. Design of Grazing-Incidence Broad-Band Multilayers for Hard X-Ray Reflectors

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhong; WANG Zhan-Shan; WANG Feng-Li; QIN Shu-Ji; CHEN Ling-Yan

    2004-01-01

    @@ A new method of designing x-ray supermirrors with broad angular or energy response for use as coatings in x-ray optics is presented. The design is based on an analytical method with oversimplified analytical and semi-empirical formulae, and an extensive numerical method is used in the optimization design. A better initial multilayer is obtained with the former method and optimized with the latter method. In the optimization, a good design is achieved with much less computing time. In addition, the saturation effect due to the interfacial roughness in multilayer also emerges in the design of x-ray supermirrors with definite performances. The reflectivity of C/W x-ray supermirrors as a function of photon energy at the fixed grazing incident angle 0.5° is presented.

  17. Broad-Band Spectrum of The Black Hole Candidate IGR J17497-2821 Studied with Suzaku

    CERN Document Server

    Paizis, A; Takahashi, H; Dotani, T; Kohmura, T; Kokubun, M; Rodríguez, J; Ueda, Y; Walter, R; Yamada, S; Yamaoka, K; Yuasa, T

    2008-01-01

    The broad-band 1-300 keV Suzaku spectrum of IGR J17497-2821, the X-ray transient discovered by INTEGRAL in September 2006, is presented. Suzaku observed IGR J17497-2821 on September 25, eight days after its discovery, for a net exposure of about 53 ksec. During the Suzaku observation, IGR J17497-2821 is very bright, 2 x 10^37 erg/s at 8 kpc in the 1-300 keV range, and shows a hard spectrum, typical of black hole candidates in the low-hard state. Despite the multi-mission X-ray monitoring of the source, only with Suzaku is it possible to obtain a broad-band spectrum in the 1-300 keV range with a very high signal to noise ratio. A sum of a multi-color disc (DISKBB) and a thermal Comptonization component (COMPPS) with mild reflection is a good representation of our IGR J17497-2821 Suzaku spectrum. The spectral properties of the accretion disc as well as the cut-off energy in the spectrum at about 150 keV are clearly detected and constrained. We discuss the implications on the physical model used to interpret the...

  18. ASTRO-H White Paper - Broad-band Spectroscopy and Polarimetry

    CERN Document Server

    Coppi, P; Done, C; Fukazawa, Y; Gandhi, P; Hagino, K; LaMassa, S; Laurent, P; Madejski, G; Mizuno, T; Mukai, K; Odaka, H; Tajima, H; Tanaka, Y; Tombesi, F; Urry, M

    2014-01-01

    The broad energy range spanned by ASTRO-H instruments, from ~0.3 to 600 keV, with its high spectral resolution calorimeter and sensitive hard X-ray imaging, offers unique opportunities to study black holes and their environments. The ability to measure polarization is particularly novel, with potential sources including blazars, Galactic pulsars and X-ray binaries. In this White Paper, we present an overview of the synergistic instrumental capabilities and the improvements over prior missions. We also show how ASTRO-H fits into the multi-wavelength landscape. We present in more detail examples and simulations of key science ASTRO-H can achieve in a typical 100 ksec observation when data from all four instruments are combined. Specifically, we consider observations of black-hole source (Cyg X-1 and GRS 1915+105), blazars (Mrk 421 and Mrk 501), a quasar (3C 273), radio galaxies (Centaurus A and 3C 120), and active galaxies with a strong starburst (Circinus and NGC 4945). We will also address possible new discov...

  19. High-performance broad-band spectroscopy for breast cancer risk assessment

    Science.gov (United States)

    Pawluczyk, Olga; Blackmore, Kristina; Dick, Samantha; Lilge, Lothar

    2005-09-01

    Medical diagnostics and screening are becoming increasingly demanding applications for spectroscopy. Although for many years the demand was satisfied with traditional spectrometers, analysis of complex biological samples has created a need for instruments capable of detecting small differences between samples. One such application is the measurement of absorbance of broad spectrum illumination by breast tissue, in order to quantify the breast tissue density. Studies have shown that breast cancer risk is closely associated with the measurement of radiographic breast density measurement. Using signal attenuation in transillumination spectroscopy in the 550-1100nm spectral range to measure breast density, has the potential to reduce the frequency of ionizing radiation, or making the test accessible to younger women; lower the cost and make the procedure more comfortable for the patient. In order to determine breast density, small spectral variances over a total attenuation of up to 8 OD have to be detected with the spectrophotometer. For this, a high performance system has been developed. The system uses Volume Phase Holographic (VPH) transmission grating, a 2D detector array for simultaneous registration of the whole spectrum with high signal to noise ratio, dedicated optical system specifically optimized for spectroscopic applications and many other improvements. The signal to noise ratio exceeding 50,000 for a single data acquisition eliminates the need for nitrogen cooled detectors and provides sufficient information to predict breast tissue density. Current studies employing transillumination breast spectroscopy (TIBS) relating to breast cancer risk assessment and monitoring are described.

  20. Broad band polarimetric follow-up of Type IIP SN 2012aw

    CERN Document Server

    Kumar, Brajesh; Eswaraiah, C; Gorosabel, J

    2014-01-01

    We present the results based on R-band polarimetric follow-up observations of the nearby (~10 Mpc) Type II-plateau SN 2012aw. Starting from ~10 days after the SN explosion, these polarimetric observations cover ~90 days (during the plateau phase) and are distributed over 9 epochs. To characterize the Milky Way interstellar polarization (ISP_MW ), we have observed 14 field stars lying in a radius of 10 degree around the SN. We have also tried to subtract the host galaxy dust polarization component assuming that the dust properties in the host galaxy are similar to that observed for Galactic dust and the general magnetic field follow the large scale structure of the spiral arms of a galaxy. After correcting the IS_PMW , our analysis infer that SN 2012aw has maximum polarization of 0.85% +- 0.08% but polarization angle does not show much variation with a weighted mean value of ~138 degree. However, if both ISP_MW and host galaxy polarization (ISP_HG ) components are subtracted from the observed polarization valu...

  1. Harvesting Broad Frequency Band Blue Energy by a Triboelectric-Electromagnetic Hybrid Nanogenerator.

    Science.gov (United States)

    Wen, Zhen; Guo, Hengyu; Zi, Yunlong; Yeh, Min-Hsin; Wang, Xin; Deng, Jianan; Wang, Jie; Li, Shengming; Hu, Chenguo; Zhu, Liping; Wang, Zhong Lin

    2016-07-26

    Ocean wave associated energy is huge, but it has little use toward world energy. Although such blue energy is capable of meeting all of our energy needs, there is no effective way to harvest it due to its low frequency and irregular amplitude, which may restrict the application of traditional power generators. In this work, we report a hybrid nanogenerator that consists of a spiral-interdigitated-electrode triboelectric nanogenerator (S-TENG) and a wrap-around electromagnetic generator (W-EMG) for harvesting ocean energy. In this design, the S-TENG can be fully isolated from the external environment through packaging and indirectly driven by the noncontact attractive forces between pairs of magnets, and W-EMG can be easily hybridized. Notably, the hybrid nanogenerator could generate electricity under either rotation mode or fluctuation mode to collect energy in ocean tide, current, and wave energy due to the unique structural design. In addition, the characteristics and advantages of outputs indicate that the S-TENG is irreplaceable for harvesting low rotation speeds (blue energy, while W-EMG is able to produce larger output at high frequencies (>10 Hz). The complementary output can be maximized and hybridized for harvesting energy in a broad frequency range. Finally, a single hybrid nanogenerator unit was demonstrated to harvest blue energy as a practical power source to drive several LEDs under different simulated water wave conditions. We also proposed a blue energy harvesting system floating on the ocean surface that could simultaneously harvest wind, solar, and wave energy. The proposed hybrid nanogenerator renders an effective and sustainable progress in practical applications of the hybrid nanogenerator toward harvesting water wave energy offered by nature.

  2. An efficient broad-band mid-wave IR fiber optic light source: Design and performance simulation

    CERN Document Server

    Barh, A; Varshney, R K; Pal, B P

    2013-01-01

    Design of a mid-wave IR (MWIR) broad-band fiber-based light source exploiting four-wave mixing (FWM) in a meter long suitably designed highly nonlinear (NL) chalcogenide microstructured optical fiber (MOF) is reported. This superior FWM bandwidth (BW) was obtained through precise tailoring of the fibers dispersion profile so as to realize positive quartic dispersion at the pump wavelength. We consider an Erbium (Er3+) doped continuous wave (CW) ZBLAN fiber laser emitting at 2.8 micron as the pump source with an average power of 5 W. Amplification factor as high as 25 dB is achievable in the 3 to 3.9 microns spectral range with average power conversion efficiency more than 32 percent.

  3. Which are the youngest protostars? Determining properties of confirmed and candidate Class0 sources by broad-band photometry

    CERN Document Server

    Fröbrich, D

    2004-01-01

    We searched the literature to obtain a complete list of known Class0 sources. A list of 95 confirmed or candidate objects was compiled. To the best of our knowledge, all published broad-band observations from 1mu to 3.5mm have been collected and are assembled in a catalogue. These data were used to determine physical properties (T_bol, L_bol, L_smm/L_bol, M_env) and for a uniform classification. 50 sources possess sufficient observational data and are classified as Class0 or Class0/1 objects. The source properties are compared with different evolutionary models to infer ages and masses, and their correlations are investigated. About 25% of the sources are found to be in a quiet accretion phase or possess a significantly different time evolution of the accretion rate than the average. In Taurus, with its isolated star formation mode, this seems especially to be the case.

  4. A flexible experimental setup for femtosecond time-resolved broad-band ellipsometry and magneto-optics

    Energy Technology Data Exchange (ETDEWEB)

    Boschini, F.; Hedayat, H.; Piovera, C.; Dallera, C. [Dipartimento di Fisica, Politecnico di Milano, p.zza Leonardo da Vinci 32, 20133 Milano (Italy); Gupta, A. [Department of Chemistry, University of Alabama, Tuscaloosa, Alabama 35487 (United States); Carpene, E., E-mail: ettore.carpene@polimi.it [CNR-IFN, Dipartimento di Fisica, Politecnico di Milano, p.zza Leonardo da Vinci 32, 20133 Milano (Italy)

    2015-01-15

    A versatile experimental setup for femtosecond time-resolved ellipsometry and magneto-optical Kerr effect measurements in the visible light range is described. The apparatus is based on the pump-probe technique and combines a broad-band probing beam with an intense near-infrared pump. According to Fresnel scattering matrix formalism, the analysis of the reflected beam at different polarization states of the incident probe light allows one to determine the diagonal and the off-diagonal elements of the dielectric tensor in the investigated sample. Moreover, the pump-probe method permits to study the dynamics of the dielectric response after a short and intense optical excitation. The performance of the experimental apparatus is tested on CrO{sub 2} single crystals as a benchmark.

  5. Phase velocities of Rayleigh and Love waves in central and northern Europe from automated, broad-band, interstation measurements

    Science.gov (United States)

    Soomro, R. A.; Weidle, C.; Cristiano, L.; Lebedev, S.; Meier, T.; Passeq Working Group

    2016-01-01

    The increasingly dense coverage of Europe with broad-band seismic stations makes it possible to image its lithospheric structure in great detail, provided that structural information can be extracted effectively from the very large volumes of data. We develop an automated technique for the measurement of interstation phase velocities of (earthquake-excited) fundamental-mode surface waves in very broad period ranges. We then apply the technique to all available broad-band data from permanent and temporary networks across Europe. In a new implementation of the classical two-station method, Rayleigh and Love dispersion curves are determined by cross-correlation of seismograms from a pair of stations. An elaborate filtering and windowing scheme is employed to enhance the target signal and makes possible a significantly broader frequency band of the measurements, compared to previous implementations of the method. The selection of acceptable phase-velocity measurements for each event is performed in the frequency domain, based on a number of fine-tuned quality criteria including a smoothness requirement. Between 5 and 3000 single-event dispersion measurements are averaged per interstation path in order to obtain robust, broad-band dispersion curves with error estimates. In total, around 63,000 Rayleigh- and 27,500 Love-wave dispersion curves between 10 and 350 s have been determined, with standard deviations lower than 2 per cent and standard errors lower than 0.5 per cent. Comparisons of phase-velocity measurements using events at opposite backazimuths and the examination of the variance of the phase-velocity curves are parts of the quality control. With the automated procedure, large data sets can be consistently and repeatedly measured using varying selection parameters. Comparison of average interstation dispersion curves obtained with different degrees of smoothness shows that rough perturbations do not systematically bias the average dispersion measurement. They

  6. Search for gamma ray burst quasi simultaneous optical emission with BOOTES-1

    Science.gov (United States)

    Castro Cerón, J. M.; Castro-Tirado, A. J.; Soldán, J.; Hudec, R.; Bernas, M.; Páta, P.; Mateo Sanguino, T. J.; de Ugarte Postigo, A.; Berná, J. Á; Nekola, M.; Gorosabel, J.; de la Morena, B. A.; Más-Hesse, J. M.; Giménez, Á.; Torres Riera, J.

    The Burst Observer and Optical Transient Exploring System experiment (BOOTES) has been designed to provide an automatic real time observing response to the detection of Gamma Ray Bursts (GRBs). It achieves such response by using wide field cameras attached to small robotic telescopes and imaging in the B,I and R bands. To date we have obtained images for about 50 events with the Wide Field Camera (WFC), starting, in several ocasions, 3 minutes after the burst commenced. One of the last searches resulted in the detection of an optical transient, candidate to be the optical counterpart of the GRB 000313, although such relation has not been established to absolute certainty yet.

  7. Swiss AlpArray: deployment of the Swiss AlpArray temporary broad-band stations and their noise characterization

    Science.gov (United States)

    Molinari, Irene; Kissling, Edi; Clinton, John; Hetényi, György; Šipka, Vesna; Stipćević, Josip; Dasović, Iva; Solarino, Stefano; Wéber, Zoltán; Gráczer, Zoltán; Electronics Lab, SED

    2016-04-01

    One of the main actions of the AlpArray European initiative is the deployment of a dense seismic broad-band network, that complements the existing permanent stations. This will ensure a spatially homogeneous seismic coverage of the greater Alpine area for at least two years, allowing a great number of innovative scientific works to be carried out. Our contribution to the AlpArray Seismic Network consists in the deployment of 24 temporary broad-band stations: three in Switzerland, twelve in Italy, three in Croatia, three in Bosnia and Herzegovina and three in Hungary. This deployment is lead by ETH Zurich and founded by the Swiss-AlpArray Sinergia programme by SNSF, and is the result of a fruitful collaboration between five research institutes. Stations were installed between Autumn and Winter 2015. Our installations are both free field and in-house and consist of 21 STS-2 and 3 Trillium Compact sensors equipped with Taurus digitizers and 3G telemetry sending data in real time to the ETH EIDA node. In this work, we present sites and stations setting and we discuss in details the characteristics in terms of site effects and noise level of each station. In particular we analyse the power spectral density estimates investigating the major source of noise and the background noise related to seasons, time of the day, human activities and type of installation. In addition we will show examples of data usage - i.e. earthquake locations, noise cross correlations, measures of surface wave dispersion curves. We thanks the Swiss AlpArray Field Team: Blanchard A., Erlanger E. D., Jarić D., Herak D., M. Herak, Hermann M., Koelemeijer P. J., Markušić S., Obermann A., Sager K., Šikman S., Singer J., Winterberg S. SED Electronic Lab: Barman S., Graf P., Hansemann R., Haslinger F., Hiemer S., Racine R., Tanner R., Weber F.

  8. Recovering galaxy stellar population properties from broad-band spectral energy distribution fitting II. The case with unknown redshift

    CERN Document Server

    Pforr, Janine; Tonini, Chiara

    2013-01-01

    (Abridged) In a recent work we explored the dependence of galaxy stellar population properties derived from broad-band spectral energy distribution fitting on the fitting parameters, e.g. SFHs, age grid, metallicity, IMF, dust reddening, reddening law, filter setup and wavelength coverage. In this paper we consider also redshift as a free parameter in the fit and study whether one can obtain reasonable estimates of photometric redshifts and stellar population properties at once. We use mock star-forming as well as passive galaxies placed at various redshifts (0.5 to 3) as test particles. Mock star-forming galaxies are extracted from a semi-analytical galaxy formation model. We show that for high-z star-forming galaxies photometric redshifts, stellar masses and reddening can be determined simultaneously when using a broad wavelength coverage and a wide template setup in the fit. Masses are similarly well recovered (median ~ 0.2 dex) as at fixed redshift. For old galaxies with little recent star formation masse...

  9. Broad-band spectral energy distribution of 3000 Angstroem break quasars from the Sloan Digital Sky Survey

    CERN Document Server

    Meusinger, H; Mirhosseini, A; Pertermann, F

    2016-01-01

    The Sloan Digital Sky Survey (SDSS) discovered a few unusual quasars with a characteristic break in the continuum around 3000 A that neither shows the typical structure of broad absorption line (BAL) troughs nor is explained by typical intrinsic dust reddening. We used the method of Kohonen self-organising maps for a systematical search for quasars with such properties in the SDSS spectra archive. We constructed a sample of 23 quasars classified as 3000 A break quasars and two comparison samples of quasars with similar properties, to some extent, but also showing typical BAL features. We computed ensemble-averaged broad-band SEDs based on archival data from SDSS, GALEX, 2MASS, UKIDSS, and WISE. The SEDs were corrected for intrinsic dust absorption by the comparison with the average SED of normal quasars. The de-reddened arithmetic median composite SED of the 3000 A break quasars is found to be indistinguishable from that of the unusual BAL quasars. We conclude that 3000 A break quasars are most likely extreme...

  10. Broad Band X-ray Spectra of Atoll Source 4U 1636-536: NuSTAR and Swift Results

    CERN Document Server

    Agrawal, Vivek Kumar

    2016-01-01

    In this work we investigate broad band (1-79 keV) spectral nature of the atoll source 4U 1636-536 using the combined Nu-STAR and SWIFT-XRT data. The spectra are complex and have emission components from the disc, boundary-layer and corona. In addition to that a broad iron line is also observed. A relativistic line model assuming Schwarzchild metric fits this feature. The total flux varies from 1.4 $\\times$ 10$^{-9}$ to 4.36 $\\times$ 10$^{-9}$ $ergs/s/cm^2$. At the highest flux level the source was found in the soft state. In this state the Comptonized component has temperature $kT_e \\sim 3$ keV and optical depth $\\tau \\sim $ 16. We also detect a non-thermal tail with index $\\sim$ 2.4, contributing $\\sim$ 10 \\% of the total flux in the soft state. We also find that the inner disc radius, electron temperature and optical depth vary with the total 0.1-100 keV unabsorbed flux. We discuss the implication of the results in this paper.

  11. Real-time monitoring of reactive species in downstream etch reactor by VUV broad-band absorption spectroscopy

    Science.gov (United States)

    Soriano, R.; Vallier, L.; Cunge, G.; Sadeghi, N.

    2016-09-01

    Plasma etching of nanometric size, high aspect-ratio structures is more challenging at each new technological node. Remote plasmas are beginning to find use when damages on nanostructures by ion bombardment become critical or when etching with high selectivity on different materials present on the wafer is necessary (i . e . tungsten oxide etching with fluorine and hydrogen containing plasmas in remote reactor from AMAT). Furthermore, it is expected that downstream plasma will replace many wet chemical etching processes to alleviate the issue of pattern collapses caused by capillary forces when nanometer size high aspect ratio structures are immersed in liquids. In these downstream plasmas, radicals are the main active species and a control of their density is of prime importance. Most of gases used and radicals produced in etching plasmas (HBr, BrCl, Br2, NF3, CH2F2,...) have strong absorption bands in the vacuum UV spectral region and we have shown that very low concentration of these species can be detected by VUV absorption. We have recently improved the technique by using a VUV CCD camera, instead of the PMT, which render possible the Broad-Band absorption spectroscopy in the 120-200 nm range, with a deuterium lamp, or a laser produced xenon arc lamp as light source. The multi-spectral detection ability of the CCD reduces the acquisition time to less than 1 second and can permit the real time control of the process control.

  12. Synchronous chaos and broad band gamma rhythm in a minimal multi-layer model of primary visual cortex.

    Directory of Open Access Journals (Sweden)

    Demian Battaglia

    2011-10-01

    Full Text Available Visually induced neuronal activity in V1 displays a marked gamma-band component which is modulated by stimulus properties. It has been argued that synchronized oscillations contribute to these gamma-band activity. However, analysis of Local Field Potentials (LFPs across different experiments reveals considerable diversity in the degree of oscillatory behavior of this induced activity. Contrast-dependent power enhancements can indeed occur over a broad band in the gamma frequency range and spectral peaks may not arise at all. Furthermore, even when oscillations are observed, they undergo temporal decorrelation over very few cycles. This is not easily accounted for in previous network modeling of gamma oscillations. We argue here that interactions between cortical layers can be responsible for this fast decorrelation. We study a model of a V1 hypercolumn, embedding a simplified description of the multi-layered structure of the cortex. When the stimulus contrast is low, the induced activity is only weakly synchronous and the network resonates transiently without developing collective oscillations. When the contrast is high, on the other hand, the induced activity undergoes synchronous oscillations with an irregular spatiotemporal structure expressing a synchronous chaotic state. As a consequence the population activity undergoes fast temporal decorrelation, with concomitant rapid damping of the oscillations in LFPs autocorrelograms and peak broadening in LFPs power spectra. We show that the strength of the inter-layer coupling crucially affects this spatiotemporal structure. We predict that layer VI inactivation should induce global changes in the spectral properties of induced LFPs, reflecting their slower temporal decorrelation in the absence of inter-layer feedback. Finally, we argue that the mechanism underlying the emergence of synchronous chaos in our model is in fact very general. It stems from the fact that gamma oscillations induced by

  13. A kind of deep-water broad-band transducer%一种深水宽带换能器

    Institute of Scientific and Technical Information of China (English)

    夏铁坚; 郝浩琦

    2012-01-01

    深海潜水器是支撑探查和开发深海资源、开展深海科学研究、进行深海工程作业的重要装备,作为深海潜水器上的重要部件,可在超深水工作的声学换能器具有广泛的应用前景.介绍了一种深水宽带换能器的设计方法,采用纵弯换能器,该型换能器利用纵向振动和前盖板弯曲振动相互耦合,具有宽带工作的特点;换能器封装在带有压力平衡装置的耐压外壳中,耐压外壳采用钛合金材料,外壳及换能器内部充有硅油.实际测试表明,换能器最大工作深度可达7000m,最大声源级大于195dB,工作频段7~15kHz,覆盖了深海探测领域常用的频段,具有良好的适应性和广泛的应用前景.%The deep submergence vehicle is very important equipment for ocean exploitation, scientific research and engineering construction in deep ocean. As a key component of the deep submergence vehicle, the deep-water transducer has broad application foreground. This paper presents the design of a deep-water transducer with a feature of broad bandwidth. The tonpilz transducer's head mass is properly designed for coupling the longitudinal and flexural vibration; the bandwidth of the transducer hence can be broadened. The transducer is encapsulated in a pressure-resisted titanium alloy shell, which has pressure balance equipment. The silicon oil is filled between the transducer and the shell. The maximum operating depth is 7000 meters, the maximum source level is beyond 195 dB, and the working frequency band is 7-15 kHz, which contain the usual frequency band in deep ocean detection. It has well adaptability and broad application foreground.

  14. Highly luminescent S, N co-doped graphene quantum dots with broad visible absorption bands for visible light photocatalysts

    Science.gov (United States)

    Qu, Dan; Zheng, Min; Du, Peng; Zhou, Yue; Zhang, Ligong; Li, Di; Tan, Huaqiao; Zhao, Zhao; Xie, Zhigang; Sun, Zaicheng

    2013-11-01

    A facile hydrothermal synthesis route to N and S, N co-doped graphene quantum dots (GQDs) was developed by using citric acid as the C source and urea or thiourea as N and S sources. Both N and S, N doped GQDs showed high quantum yield (78% and 71%), excitation independent under excitation of 340-400 nm and single exponential decay under UV excitation. A broad absorption band in the visible region appeared in S, N co-doped GQDs due to doping with sulfur, which alters the surface state of GQDs. However, S, N co-doped GQDs show different color emission under excitation of 420-520 nm due to their absorption in the visible region. The excellent photocatalytic performance of the S, N co-doped GQD/TiO2 composites was demonstrated by degradation of rhodamine B under visible light. The apparent rate of S, N:GQD/TiO2 is 3 and 10 times higher than that of N:GQD/TiO2 and P25 TiO2 under visible light irradiation, respectively.A facile hydrothermal synthesis route to N and S, N co-doped graphene quantum dots (GQDs) was developed by using citric acid as the C source and urea or thiourea as N and S sources. Both N and S, N doped GQDs showed high quantum yield (78% and 71%), excitation independent under excitation of 340-400 nm and single exponential decay under UV excitation. A broad absorption band in the visible region appeared in S, N co-doped GQDs due to doping with sulfur, which alters the surface state of GQDs. However, S, N co-doped GQDs show different color emission under excitation of 420-520 nm due to their absorption in the visible region. The excellent photocatalytic performance of the S, N co-doped GQD/TiO2 composites was demonstrated by degradation of rhodamine B under visible light. The apparent rate of S, N:GQD/TiO2 is 3 and 10 times higher than that of N:GQD/TiO2 and P25 TiO2 under visible light irradiation, respectively. Electronic supplementary information (ESI) available: More XPS and UV-Vis spectra. See DOI: 10.1039/c3nr04402e

  15. The Seismic Broad Band Western Mediterranean (wm) Network and the Obs Fomar Pool: Current state and Obs activities.

    Science.gov (United States)

    Pazos, Antonio; Davila, Jose Martin; Buforn, Elisa; Bezzeghoud, Mourad; Harnafi, Mimoun; Mattesini, Mauricio; Caldeira, Bento; Hanka, Winfried; El Moudnib, Lahcen; Strollo, Angelo; Roca, Antoni; Lopez de Mesa, Mireya; Dahm, Torsten; Cabieces, Roberto

    2016-04-01

    The Western Mediterranean (WM) seismic network started in 1996 as an initiative of the Royal Spanish Navy Observatory (ROA) and the Universidad Complutense de Madrid (UCM), with the collaboration of the GeoForschungsZentrum (GFZ) of Potsdam. A first broad band seismic station (SFUC) was installed close to Cádiz (South Spain). Since then, additional stations have been installed in the Ibero-Moghrebian region. In 2005, the "WM" code was assigned by the FDSN and new partners were jointed: Evora University (UEVO, Portugal), the Scientifique Institute of Rabat (ISRABAT, Morocco), and GFZ. Now days, the WM network is composed by 15 BB stations, all of them with Streckaisen STS-2 or STS-2.5 sensors, Quanterra or Earthdata digitizers and SeiscomP. Most them have co-installed a permanent geodetic GPS stations, and some them also have an accelerometer. There are 10 stations deployed in Spanish territory (5 in the Iberian peninsula, 1 in Balearic islands and 4 in North Africa Spanish places) with VSAT or Internet communications, 2 in Portugal (one of them without real time), and 3 in Morocco (2 VSAT and 1 ADSL). Additionally, 2 more stations (one in South Spain and one in Morocco) will be installed along this year. Additionally ROA has deployed a permanent real time VBB (CMG-3T: 360s) station at the Alboran Island. Due to the fact that part of the seismic activity is located at marine areas, and also because of the poor geographic azimuthal coverage at some zones provided by the land stations (specially in the SW of the San Vicente Cape area), ROA and UCM have acquired six broad band "LOBSTERN" OBS, manufactured by KUM (Kiel, Germany), conforming the OBS FOMAR pool. Three of them with CMG-40T sensor and the other with Trillium 120. These OBS were deployed along the Gibraltar strait since January to November 2014 to study the microseismicity in the Gibraltar strait area. In September 2015 FOMAR network has been deployed in SW of the San Vicente Cape for 8 months as a part of

  16. Broad-band spectral changes of the microquasars Cygnus X-1 and SWIFT J1753.5-0127

    CERN Document Server

    Bel, M C; Rodríguez, J; Chaty, S; Corbel, S; Goldwurm, A; Bel, Marion Cadolle; Ribo, Marc; Rodriguez, Jerome; Chaty, Sylvain; Corbel, Stephane; Goldwurm, Andrea

    2006-01-01

    We report high-energy results obtained with INTEGRAL and Rossi-XTE on two microquasars: the persistent high-mass system Cygnus X-1 and the transient low-mass binary SWIFT J1753.5-0127. INTEGRAL observed Cygnus X-1 from 2002 to 2004: the spectral (5-1000 keV) properties of the source, seen at least in three distinct spectral states, show disc and corona changes. In 2003 June, a high-energy tail at several hundred keV in excess of the thermal Comptonization model was observed, suggesting the presence of an additional non-thermal component. At that time, we detected an unusual correlation between radio data and high-energy hardness. We also report and compare the results obtained with simultaneous observations of the transient source SWIFT J1753.5-0127 performed with Rossi-XTE, INTEGRAL, VLA, REM and NTT on 2005 August 10-12 near its hard X-ray outburst. Broad-band spectra and fast time-variability properties are derived on this source (probably located in the galactic halo) together with radio, IR and optical d...

  17. Extreme Emission Line Galaxies in CANDELS: Broad-Band Selected, Star-Bursting Dwarf Galaxies at z>1

    CERN Document Server

    van der Wel, A; Rix, H -W; Finkelstein, S L; Koekemoer, A M; Weiner, B J; Wuyts, S; Bell, E F; Faber, S M; Trump, J R; Koo, D; Ferguson, H C; Scarlata, C; Hathi, N P; Dunlop, J S; Newman, J A; Dickinson, M; Salmon, B; Kocevski, D F de Mello D D; Lai, K; Grogin, N A; Rodney, S A; Guo, Yicheng; McGrath, E G; Lee, K -S; Calvo, G B; Huang, K -H

    2011-01-01

    We identify an abundant population of extreme emission line galaxies (EELGs) at redshift z=1.6-1.8 in the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS) imaging from Hubble Space Telescope/Wide Field Camera 3 (HST/WFC3). 69 EELG candidates are selected by the large contribution of exceptionally bright emission lines to their near-infrared, broad-band fluxes. Supported by spectroscopic confirmation of strong [OIII] emission lines -- with rest-frame equivalent widths ~1000\\AA -- in the four candidates that have HST/WFC3 grism observations, we conclude that these objects are dwarf galaxies with ~10^8 Msol in stellar mass, undergoing an enormous starburst phase with M*/(dM*/dt) of only ~15 Myr. These bursts may cause outflows that are strong enough to produce cored dark matter profiles in low-mass galaxies. The individual star formation rates and the co-moving number density (3.7 x 10^-4 Mpc^-3) can produce in ~4 Gyr much of the stellar mass density that is presently contained in 10^8-10^9 Mso...

  18. Performance of the NIST goniocolorimeter with a broad-band source and multichannel charged coupled device based spectrometer

    Science.gov (United States)

    Podobedov, V. B.; Miller, C. C.; Nadal, M. E.

    2012-09-01

    The authors describe the NIST high-efficiency instrument for measurements of bidirectional reflectance distribution function of colored materials, including gonioapparent materials such as metallic and pearlescent coatings. The five-axis goniospectrometer measures the spectral reflectance of samples over a wide range of illumination and viewing angles. The implementation of a broad-band source and a multichannel CCD spectrometer corrected for stray light significantly increased the efficiency of the goniometer. In the extended range of 380 nm to 1050 nm, a reduction of measurement time from a few hours to a few minutes was obtained. Shorter measurement time reduces the load on the precise mechanical assembly ensuring high angular accuracy over time. We describe the application of matrix-based correction of stray light and the extension of effective dynamic range of measured fluxes to the values of 106 to 107 needed for the absolute characterization of samples. The measurement uncertainty was determined to be 0.7% (k = 2), which is comparable with similar instruments operating in a single channel configuration. Several examples of reflectance data obtained with the improved instrument indicate a 0.3% agreement compared to data collected with the single channel configuration.

  19. 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.

  20. Spectral modification of the laser emission of a terahertz quantum cascade laser induced by broad-band double pulse injection seeding

    Energy Technology Data Exchange (ETDEWEB)

    Markmann, Sergej, E-mail: sergej.markmann@ruhr-uni-bochum.de; Nong, Hanond, E-mail: nong.hanond@ruhr-uni-bochum.de; Hekmat, Negar; Jukam, Nathan [AG Terahertz Spektroskopie und Technologie, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Pal, Shovon [AG Terahertz Spektroskopie und Technologie, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Scholz, Sven; Kukharchyk, Nadezhda; Ludwig, Arne; Wieck, Andreas D. [Lehrstuhl für Angewandte Festkörperphysik, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Dhillon, Sukhdeep; Tignon, Jérôme [Laboratoire Pierre Aigrain, Ecole Normale Supérieure, UMR 8551 CNRS, UPMC, Univ. Paris 6, 75005 Paris (France); Marcadet, Xavier [Alcatel-Thales III-V Lab, Route Départementale 128, 91767 Palaiseau Cedex (France); Bock, Claudia; Kunze, Ulrich [Lehrstuhl für Werkstoffe und Nanoelektronik, Ruhr-Universität Bochum, D-44780 Bochum (Germany)

    2015-09-14

    We demonstrate by injection seeding that the spectral emission of a terahertz (THz) quantum cascade laser (QCL) can be modified with broad-band THz pulses whose bandwidths are greater than the QCL bandwidth. Two broad-band THz pulses delayed in time imprint a modulation on the single THz pulse spectrum. The resulting spectrum is used to injection seed the THz QCL. By varying the time delay between the THz pulses, the amplitude distribution of the QCL longitudinal modes is modified. By applying this approach, the QCL emission is reversibly switched from multi-mode to single mode emission.

  1. A physical parameter method for the design of broad-band X-ray imaging systems to do coronal plasma diagnostics

    Science.gov (United States)

    Kahler, S.; Krieger, A. S.

    1978-01-01

    The technique commonly used for the analysis of data from broad-band X-ray imaging systems for plasma diagnostics is the filter ratio method. This requires the use of two or more broad-band filters to derive temperatures and line-of-sight emission integrals or emission measure distributions as a function of temperature. Here an alternative analytical approach is proposed in which the temperature response of the imaging system is matched to the physical parameter being investigated. The temperature response of a system designed to measure the total radiated power along the line of sight of any coronal structure is calculated. Other examples are discussed.

  2. Broad-band Seismology for Understanding Earthquake Physics and Developing a Modern Practice for Seismic Damage Mitigation

    Science.gov (United States)

    Kanamori, H.; Heaton, T. H.

    2003-12-01

    In 1987, immediately after the 1987 Whittier Narrows earthquake, the Caltech broad-band regional seismic network project, TERRAscope, was launched under the direction of Don Anderson. At the time, UC Berkeley had also embarked on such a project. The objectives included: 1) Collect high-quality seismic data for developing theories of Earth's interior and exterior, 2) Develop a physics-based earthquake damage mitigation method, 3) Provide a test-bed for novel approaches in real-time seismology, 4) Provide an infrastructure for cultivating new directions in seismology. The data from TERRAscope, combined with those from other networks such as GDSN, IDA, IRIS, GeoScope networks were used to study various seismological problems, some of which had not been commonly investigated. We focus on three areas. The interaction between the solid earth and atmosphere had been the subject of considerable interest. The broadband networks detected interesting atmospheric waves from a few Hz (N waves from space shuttles) to 0.001 Hz (Morning-glory waves. At the time it was not recognized as such). Also, it recorded monochromatic (period ˜ 230 sec) Rayleigh waves which were generated by the near source atmospheric oscillations excited by the 1991 Pinatubo eruption. These waves were not immediately recognized as such, because they had not been observed yet. This represents one of few cases in which significant energy transfer occurred from the atmosphere to the solid earth. These observations eventually led to the more ambitious ongoing projects for detecting ionospheric signature of acoustic and internal gravity waves in the atmosphere that couple into the solid earth. Gutenberg, together with Richter, published a series of papers on the energy of earthquakes in the 1940's to 1950's. The intent of these studies was to determine the most important quantity necessary for understanding the fundamental physics of earthquakes. Unfortunately, because of the overwhelming observational

  3. X-Ray Emitting GHz-Peaked Spectrum Galaxies: Testing a Dynamical-Radiative Model with Broad-Band Spectra

    Energy Technology Data Exchange (ETDEWEB)

    Ostorero, L.; /Turin U. /INFN, Turin; Moderski, R.; /Warsaw, Copernicus Astron. Ctr. /KIPAC, Menlo Park; Stawarz, L.; /KIPAC, Menlo Park /Jagiellonian U., Astron. Observ.; Diaferio, A.; /Turin U. /INFN, Turin; Kowalska, I.; /Warsaw U. Observ.; Cheung, C.C.; /NASA, Goddard /Naval Research Lab, Wash., D.C.; Kataoka, J.; /Waseda U., RISE; Begelman, M.C.; /JILA, Boulder; Wagner, S.J.; /Heidelberg Observ.

    2010-06-07

    In a dynamical-radiative model we recently developed to describe the physics of compact, GHz-Peaked-Spectrum (GPS) sources, the relativistic jets propagate across the inner, kpc-sized region of the host galaxy, while the electron population of the expanding lobes evolves and emits synchrotron and inverse-Compton (IC) radiation. Interstellar-medium gas clouds engulfed by the expanding lobes, and photoionized by the active nucleus, are responsible for the radio spectral turnover through free-free absorption (FFA) of the synchrotron photons. The model provides a description of the evolution of the GPS spectral energy distribution (SED) with the source expansion, predicting significant and complex high-energy emission, from the X-ray to the {gamma}-ray frequency domain. Here, we test this model with the broad-band SEDs of a sample of eleven X-ray emitting GPS galaxies with Compact-Symmetric-Object (CSO) morphology, and show that: (i) the shape of the radio continuum at frequencies lower than the spectral turnover is indeed well accounted for by the FFA mechanism; (ii) the observed X-ray spectra can be interpreted as non-thermal radiation produced via IC scattering of the local radiation fields off the lobe particles, providing a viable alternative to the thermal, accretion-disk dominated scenario. We also show that the relation between the hydrogen column densities derived from the X-ray (N{sub H}) and radio (N{sub HI}) data of the sources is suggestive of a positive correlation, which, if confirmed by future observations, would provide further support to our scenario of high-energy emitting lobes.

  4. REVERBERATION MAPPING WITH INTERMEDIATE-BAND PHOTOMETRY: DETECTION OF BROAD-LINE Hα TIME LAGS FOR QUASARS AT 0.2 < z < 0.4

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Linhua [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China); Shen, Yue [Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); McGreer, Ian D.; Fan, Xiaohui [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Morganson, Eric [National Center for Supercomputing Applications, University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Windhorst, Rogier A., E-mail: jiangKIAA@pku.edu.cn [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States)

    2016-02-20

    We present a reverberation mapping (RM) experiment that combines broad- and intermediate-band photometry; it is the first such attempt targeting 13 quasars at 0.2 < z < 0.9. The quasars were selected to have strong Hα or Hβ emission lines that are located in one of three intermediate bands (with FWHM around 200 Å) centered at 8045, 8505, and 9171 Å. The imaging observations were carried out in the intermediate bands and the broad i and z bands using the prime-focus imager 90Prime on the 2.3 m Bok telescope. Because of the large (∼1 deg{sup 2}) field of view (FOV) of 90Prime, we included the 13 quasars within only five telescope pointings or fields. The five fields were repeatedly observed over 20–30 epochs that were unevenly distributed over a duration of 5–6 months. The combination of the broad- and intermediate-band photometry allows us to derive accurate light curves for both optical continuum emission (from the accretion disk) and line emission (from the broad-line region, or BLR). We detect Hα time lags between the continuum and line emission in six quasars. These quasars are at relatively low redshifts 0.2 < z < 0.4. The measured lags are consistent with the current BLR size–luminosity relation for Hβ at z < 0.3. While this experiment appears successful in detecting lags of the bright Hα line, further investigation is required to see if it can also be applied to the fainter Hβ line for quasars at higher redshifts. Finally we demonstrate that, by using a small telescope with a large FOV, intermediate-band photometric RM can be efficiently executed for a large sample of quasars at z > 0.2.

  5. Imaging P-to-S conversions with broad-band seismic arrays using multichannel time-domain deconvolution

    Science.gov (United States)

    Neal, Scott L.; Pavlis, Gary L.

    2001-09-01

    reduced and the input model is reliably recovered. Further tests with data from the Lodore broad-band array in Colorado and Wyoming show significant improvement over conventional time domain methods. We image lateral variations in Moho continuity and reflectivity across the array, with significant improvement in resolution in the first 10 seconds of data.

  6. Broad-band X-ray emission and the reality of the broad iron line from the neutron star-white dwarf X-ray binary 4U 1820-30

    Science.gov (United States)

    Mondal, Aditya S.; Dewangan, G. C.; Pahari, M.; Misra, R.; Kembhavi, A. K.; Raychaudhuri, B.

    2016-09-01

    Broad relativistic iron lines from neutron star X-ray binaries are important probes of the inner accretion disc. The X-ray reflection features can be weakened due to strong magnetic fields or very low iron abundances such as is possible in X-ray binaries with low mass, first generation stars as companions. Here, we investigate the reality of the broad iron line detected earlier from the neutron-star low-mass X-ray binary 4U 1820-30 with a degenerate helium dwarf companion. We perform a comprehensive, systematic broad-band spectral study of the atoll source using Suzaku and simultaneous NuSTAR and Swift observations. We have used different continuum models involving accretion disc emission, thermal blackbody and thermal Comptonization of either disc or blackbody photons. The Suzaku data show positive and negative residuals in the region of Fe K band. These features are well described by two absorption edges at 7.67 ± 0.14 keV and 6.93 ± 0.07 keV or partial covering photoionized absorption or by blurred reflection. Though, the simultaneous Swift and NuSTAR data do not clearly reveal the emission or absorption features, the data are consistent with the presence of either absorption or emission features. Thus, the absorption based models provide an alternative to the broad iron line or reflection model. The absorption features may arise in winds from the inner accretion disc. The broad-band spectra appear to disfavour continuum models in which the blackbody emission from the neutron-star surface provides the seed photons for thermal Comptonization. Our results suggest emission from a thin accretion disc (kTdisc ˜ 1 keV), Comptonization of disc photons in a boundary layer most likely covering a large fraction of the neutron-star surface and innermost parts of the accretion disc, and blackbody emission (kTbb ˜ 2 keV) from the polar regions.

  7. Quasi-simultaneous XMM-Newton and VLA observation of the non-thermal radio emitter HD\\168112 (O5.5III(f^+))

    OpenAIRE

    De Becker, Michaël; Rauw, Grégor; Blomme, Ronny; Waldron, Wayne; Sana, Hugues; Pittard, Julian; Eenens, Philippe; Stevens, Ian Robert; Runacres, Mark; Van Loo, Sven; Pollock, Andy

    2004-01-01

    We report the results of a multiwavelength study of the non-thermal radio emitter HD 168112 (O5.5III(f+)). The detailed analysis of two quasi-simultaneous XMM-Newton and VLA observations reveals strong variability of this star both in the X-ray and radio ranges. The X-ray observations separated by five months reveal a decrease of the X-ray flux of ˜30%. The radio emission on the other hand increases by a factor 5-7 between the two observations obtained roughly simultaneously with the XMM-Newt...

  8. Comparing Broad-Band and Red Edge-Based Spectral Vegetation Indices to Estimate Nitrogen Concentration of Crops Using Casi Data

    Science.gov (United States)

    Wang, Yanjie; Liao, Qinhong; Yang, Guijun; Feng, Haikuan; Yang, Xiaodong; Yue, Jibo

    2016-06-01

    In recent decades, many spectral vegetation indices (SVIs) have been proposed to estimate the leaf nitrogen concentration (LNC) of crops. However, most of these indices were based on the field hyperspectral reflectance. To test whether they can be used in aerial remote platform effectively, in this work a comparison of the sensitivity between several broad-band and red edge-based SVIs to LNC is investigated over different crop types. By using data from experimental LNC values over 4 different crop types and image data acquired using the Compact Airborne Spectrographic Imager (CASI) sensor, the extensive dataset allowed us to evaluate broad-band and red edge-based SVIs. The result indicated that NDVI performed the best among the selected SVIs while red edge-based SVIs didn't show the potential for estimating the LNC based on the CASI data due to the spectral resolution. In order to search for the optimal SVIs, the band combination algorithm has been used in this work. The best linear correlation against the experimental LNC dataset was obtained by combining the 626.20nm and 569.00nm wavebands. These wavelengths correspond to the maximal chlorophyll absorption and reflection position region, respectively, and are known to be sensitive to the physiological status of the plant. Then this linear relationship was applied to the CASI image for generating an LNC map, which can guide farmers in the accurate application of their N fertilization strategies.

  9. COMPARING BROAD-BAND AND RED EDGE-BASED SPECTRAL VEGETATION INDICES TO ESTIMATE NITROGEN CONCENTRATION OF CROPS USING CASI DATA

    Directory of Open Access Journals (Sweden)

    Y. Wang

    2016-06-01

    Full Text Available In recent decades, many spectral vegetation indices (SVIs have been proposed to estimate the leaf nitrogen concentration (LNC of crops. However, most of these indices were based on the field hyperspectral reflectance. To test whether they can be used in aerial remote platform effectively, in this work a comparison of the sensitivity between several broad-band and red edge-based SVIs to LNC is investigated over different crop types. By using data from experimental LNC values over 4 different crop types and image data acquired using the Compact Airborne Spectrographic Imager (CASI sensor, the extensive dataset allowed us to evaluate broad-band and red edge-based SVIs. The result indicated that NDVI performed the best among the selected SVIs while red edge-based SVIs didn’t show the potential for estimating the LNC based on the CASI data due to the spectral resolution. In order to search for the optimal SVIs, the band combination algorithm has been used in this work. The best linear correlation against the experimental LNC dataset was obtained by combining the 626.20nm and 569.00nm wavebands. These wavelengths correspond to the maximal chlorophyll absorption and reflection position region, respectively, and are known to be sensitive to the physiological status of the plant. Then this linear relationship was applied to the CASI image for generating an LNC map, which can guide farmers in the accurate application of their N fertilization strategies.

  10. The broad band spectral variability of MCG-6-30-15 observed by NuSTAR and XMM-Newton

    CERN Document Server

    Marinucci, A; Miniutti, G; Guainazzi, M; Parker, M L; Brenneman, L; Fabian, A C; Kara, E; Arevalo, P; Ballantyne, D R; Boggs, S E; Cappi, M; Christensen, F E; Craig, W W; Elvis, M; Hailey, C J; Harrison, F A; Reynolds, C S; Risaliti, G; Stern, D K; Walton, D J; Zhang, W

    2014-01-01

    MCG-6-30-15, at a distance of 37 Mpc (z=0.008), is the archetypical Seyfert 1 galaxy showing very broad Fe K$\\alpha$ emission. We present results from a joint NuSTAR and XMM-Newton observational campaign that, for the first time, allows a sensitive, time-resolved spectral analysis from 0.35 keV up to 80 keV. The strong variability of the source is best explained in terms of intrinsic X-ray flux variations and in the context of the light bending model: the primary, variable emission is reprocessed by the accretion disk, which produces secondary, less variable, reflected emission. The broad Fe K$\\alpha$ profile is, as usual for this source, well explained by relativistic effects occurring in the innermost regions of the accretion disk around a rapidly rotating black hole. We also discuss the alternative model in which the broadening of the Fe K$\\alpha$ is due to the complex nature of the circumnuclear absorbing structure. Even if this model cannot be ruled out, it is disfavored on statistical grounds. We also d...

  11. Plasmonic coupling with most of the transition metals: a new family of broad band and near infrared nanoantennas

    Science.gov (United States)

    Manchon, Delphine; Lermé, Jean; Zhang, Taiping; Mosset, Alexis; Jamois, Cécile; Bonnet, Christophe; Rye, Jan-Michael; Belarouci, Ali; Broyer, Michel; Pellarin, Michel; Cottancin, Emmanuel

    2014-12-01

    In this article, we show for the first time, both theoretically and empirically, that plasmonic coupling can be used to generate Localized Surface Plasmon Resonances (LSPRs) in transition metal dimeric nano-antennas (NAs) over a broad spectral range (from the visible to the near infrared) and that the spectral position of the resonance can be controlled through morphological variation of the NAs (size, shape, interparticle distance). First, accurate calculations using the generalized Mie theory on spherical dimers demonstrate that we can take advantage of the plasmonic coupling to enhance LSPRs over a broad spectral range for many transition metals (Pt, Pd, Cr, Ni etc.). The LSPR remains broad for low interparticle distances and masks the various hybridized modes within the overall resonance. However, an analysis of the charge distribution on the surface of the nanoparticles reveals these modes and their respective contributions to the observed LSPR. In the case of spherical dimers, the transfer of the oscillator strengths from the ``dipolar'' mode to higher orders involves a maximum extinction cross-section for intermediate interparticle distances of a few nanometers. The emergence of the LSPR has been then experimentally illustrated with parallelepipedal NAs (monomers and dimers) made of various transition metals (Pt, Pd and Cr) and elaborated by nanolithography. Absolute extinction cross-sections have been measured with the spatial modulation spectroscopy technique over a broad spectral range (300-900 nm) for individual NAs, the morphology of which has been independently characterized by electron microscopy imaging. A clear enhancement of the LSPR has been revealed for a longitudinal excitation and plasmonic coupling has been clearly evidenced in dimers by an induced redshift and broadening of the LSPR compared to monomers. Furthermore, the LSPR has been shown to be highly sensitive to slight modifications of the interparticle distance. All the experimental

  12. Hard x-ray broad band Laue lenses (80 - 600 keV): building methods and performances

    CERN Document Server

    Virgilli, E; Rosati, P; Liccardo, V; Squerzanti, S; Carassiti, V; Caroli, E; Auricchio, N; Stephen, J B

    2015-01-01

    We present the status of the laue project devoted to develop a technology for building a 20 meter long focal length Laue lens for hard x-/soft gamma-ray astronomy (80 - 600 keV). The Laue lens is composed of bent crystals of Gallium Arsenide (GaAs, 220) and Germanium (Ge, 111), and, for the first time, the focusing property of bent crystals has been exploited for this field of applications. We show the preliminary results concerning the adhesive employed to fix the crystal tiles over the lens support, the positioning accuracy obtained and possible further improvements. The Laue lens petal that will be completed in a few months has a pass band of 80 - 300 keV and is a fraction of an entire Laue lens capable of focusing X-rays up to 600 keV, possibly extendable down to 20 - 30 keV with suitable low absorption crystal materials and focal length. The final goal is to develop a focusing optics that can improve the sensitivity over current telescopes in this energy band by 2 orders of magnitude.

  13. Relation between the "Double-Hump" Behavior in the Radio Band and the Broad-Line Luminosity for Blazars

    Institute of Scientific and Technical Information of China (English)

    Zhao-Hua Xie; Hong Dai; Jian-Ming Hao; Lei-Ming Du; Xiong Zhang

    2007-01-01

    The physics behind the spectral energy distribution (SED) of blazars remains open.We assembled 36 blazars to tackle the factors that control their SED. Now, many blazar spectra have the "double hump" feature in the radio and far-IR frequencies. For these a parameter,△, is created to characterize the behavior of the SED. We found a significant correlation between the broad-line luminosity (LBLR) and △. Because LBLR is an indicator of the accreting power of the source in blazars, we derived a linear correlation,△∝ (M)1/3. 18, which suggests that the SED of blazars may depend on the accretion rate, like that of BL Lac objects. We also found a significant correlation between (m) and△ for a sample of 11 blazars (out of one of 36)with available black hole masses. This implies the Eddington accretion ratio may influence the shape of the SED of blazars.

  14. The non-equilibrium response of a superconductor to pair-breaking radiation measured over a broad frequency band

    Energy Technology Data Exchange (ETDEWEB)

    Visser, P. J. de, E-mail: p.j.devisser@tudelft.nl [Kavli Institute of NanoScience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Yates, S. J. C. [SRON Netherlands Institute for Space Research, Landleven 12, 9747AD Groningen (Netherlands); Guruswamy, T.; Goldie, D. J.; Withington, S. [Cavendish Laboratory, University of Cambridge, JJ Thomson Avenue, Cambridge CB3 0HE (United Kingdom); Neto, A.; Llombart, N. [Faculty of Electrical Engineering, Mathematics and Computer Science, Terahertz Sensing Group, Delft University of Technology, Mekelweg 4, 2628 CD Delft (Netherlands); Baryshev, A. M. [SRON Netherlands Institute for Space Research, Landleven 12, 9747AD Groningen (Netherlands); Kapteyn Astronomical Institute, University of Groningen, Landleven 12, 9747 AD Groningen (Netherlands); Klapwijk, T. M. [Kavli Institute of NanoScience, Faculty of Applied Sciences, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Physics Department, Moscow State Pedagogical University, Moscow 119991 (Russian Federation); Baselmans, J. J. A. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands); Faculty of Electrical Engineering, Mathematics and Computer Science, Terahertz Sensing Group, Delft University of Technology, Mekelweg 4, 2628 CD Delft (Netherlands)

    2015-06-22

    We have measured the absorption of terahertz radiation in a BCS superconductor over a broad range of frequencies from 200 GHz to 1.1 THz, using a broadband antenna-lens system and a tantalum microwave resonator. From low frequencies, the response of the resonator rises rapidly to a maximum at the gap edge of the superconductor. From there on, the response drops to half the maximum response at twice the pair-breaking energy. At higher frequencies, the response rises again due to trapping of pair-breaking phonons in the superconductor. In practice, this is a measurement of the frequency dependence of the quasiparticle creation efficiency due to pair-breaking in a superconductor. The efficiency, calculated from the different non-equilibrium quasiparticle distribution functions at each frequency, is in agreement with the measurements.

  15. Non-thermal emission from extragalactic radio sources a high resolution broad band (radio to X-rays) approach

    CERN Document Server

    Brunetti, G

    2002-01-01

    In the framework of the study of extragalactic radio sources, we will focus on the importance of the spatial resolution at different wavelengths, and of the combination of observations at different frequency bands. In particular, a substantial step forward in this field is now provided by the new generation X-ray telescopes which are able to image radio sources in between 0.1--10 keV with a spatial resolution comparable with that of the radio telescopes (VLA) and of the optical telescopes. After a brief description of some basic aspects of acceleration mechanisms and of the radiative processes at work in the extragalactic radio sources, we will focus on a number of recent radio, optical and X-ray observations with arcsec resolution, and discuss the deriving constraints on the physics of these sources.

  16. Improving the Estimation of Star-formation Rates and Stellar Population Ages of High-redshift Galaxies from Broad-band Photometry

    CERN Document Server

    Lee, Seong-Kook; Somerville, Rachel S; Wiklind, Tommy; Giavalisco, Mauro

    2010-01-01

    We explore methods to improve the estimates of star-formation rates and mean stellar population ages from broad-band photometry of high redshift star-forming galaxies. We use synthetic spectral templates with a variety of simple parametric star-formation histories to fit broad-band spectral-energy distributions. These parametric models are used to infer ages, star-formation rates and stellar masses for a mock data set drawn from a hierarchical semi-analytic model of galaxy evolution. Traditional parametric models generally assume an exponentially declining rate of star-formation after an initial instantaneous rise. Our results show that star-formation histories with a much more gradual rise in the star-formation rate are likely to be better templates, and are likely to give better overall estimates of the age distribution and star-formation rate distribution of Lyman-break galaxies. For B- and V-dropouts, we find the best simple parametric model to be one where the star-formation rate increases linearly with ...

  17. A New Idea and Technique of Fiber Gratings and Photodetectors in Broad-band Fiber Communication Systems

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Contents of this thesis are supported by the National Natural Foudation of China under Contract No.69625101, and the item is named “Tunable Optical Technology in Wavelength Division Multiplexing (WDM)” and is under charge of Professor Ren Xiaomin. They are also supported by subject 307 in National Program “863”: i.e., RCE photodetectors (PDs) used in Wavelength Division Multiplexing. Fiber Bragg Gratings (FBGs) have emerged as important optical fiber passive components in a variety of light-wave applications. It is expected that FBGs will play a key role in the next generation of optical fiber communication systems and sensor fileds. Most of these applications are based on the narrow-band reflection of FBGs. In this thesis, transmission dispersion, nonlinearity and tunability of FBGs are studied. The main contents are as follows: Transmission dispersion of FBGs is studied and the capability of dispersion compensation of FBGs is calculated theoretically. In the experiments, the dispersions of 10 Gb/s at 11.1 km and 22.22 km are compensated successfully by an unchirped fiber grating for the first time in China and the tunable compensation is achieved for the first time internationally. The scheme of tunable dispersion compensation using cascaded fiber gratings in WDM is analyzed and designed. It is indicated that the dispersion compensation in transmission using uniform fiber gratings is a better and more effective compensation scheme compared with the tradifitonal dispersion compensation using chirped fiber gratings. It is originally proposed that people can simulate characteristics of a long distance optical fiber by a short uniform fiber grating. This is verified for the first time experimentally. In the experiment, a short grating (about 1 cm) operated in transmission is used to simulate pulse broadening of 11.1 km optical fiber. This method can be used to detect performance of long distance transmission of communication systems. It is originally proposed

  18. Negative thermal expansion and broad band photoluminescence in a novel material of ZrScMo2VO12

    Science.gov (United States)

    Ge, Xianghong; Mao, Yanchao; Liu, Xiansheng; Cheng, Yongguang; Yuan, Baohe; Chao, Mingju; Liang, Erjun

    2016-04-01

    In this paper, we present a novel material with the formula of ZrScMo2VO12 for the first time. It was demonstrated that this material exhibits not only excellent negative thermal expansion (NTE) property over a wide temperature range (at least from 150 to 823 K), but also very intense photoluminescence covering the entire visible region. Structure analysis shows that ZrScMo2VO12 has an orthorhombic structure with the space group Pbcn (No. 60) at room temperature. A phase transition from monoclinic to orthorhombic structure between 70 and 90 K is also revealed. The intense white light emission is tentatively attributed to the n- and p-type like co-doping effect which creates not only the donor- and acceptor-like states in the band gap, but also donor-acceptor pairs and even bound exciton complexes. The excellent NTE property integrated with the intense white-light emission implies a potential application of this material in light emitting diode and other photoelectric devices.

  19. Broad Balmer Wings in BA Hyper/Supergiants Distorted by Diffuse Interstellar Bands: Five Examples in the 30 Doradus Region from the VLT-FLAMES Tarantula Survey

    CERN Document Server

    Walborn, Nolan R; Evans, Christopher J; Taylor, William D; Sabbi, Elena; Barbá, Rodolfo H; Morrell, Nidia I; Apellániz, Jesús Maíz; Sota, Alfredo; Dufton, Philip L; McEvoy, Catherine M; Clark, J Simon; Markova, Nevena; Ulaczyk, Krzysztof

    2015-01-01

    Extremely broad emission wings at H$\\beta$ and H$\\alpha$ have been found in VFTS data for five very luminous BA supergiants in or near 30 Doradus in the Large Magellanic Cloud. The profiles of both lines are extremely asymmetrical, which we have found to be caused by very broad diffuse interstellar bands (DIBs) in the longward wing of H$\\beta$ and the shortward wing of H$\\alpha$. These DIBs are well known to interstellar but not to many stellar specialists, so that the asymmetries may be mistaken for intrinsic features. The broad emission wings are generally ascribed to electron scattering, although we note difficulties for that interpretation in some objects. Such profiles are known in some Galactic hyper/supergiants and are also seen in both active and quiescent Luminous Blue Variables. No prior or current LBV activity is known in these 30 Dor stars, although a generic relationship to LBVs is not excluded; subject to further observational and theoretical investigation, it is possible that these very luminou...

  20. Broad-band efficiency calibration of ITER bolometer prototypes using Pt absorbers on SiN membranes

    Science.gov (United States)

    Meister, H.; Willmeroth, M.; Zhang, D.; Gottwald, A.; Krumrey, M.; Scholze, F.

    2013-12-01

    The energy resolved efficiency of two bolometer detector prototypes for ITER with 4 channels each and absorber thicknesses of 4.5 μm and 12.5 μm, respectively, has been calibrated in a broad spectral range from 1.46 eV up to 25 keV. The calibration in the energy range above 3 eV was performed against previously calibrated silicon photodiodes using monochromatized synchrotron radiation provided by five different beamlines of Physikalische Technische Bundesanstalt at the electron storage rings BESSY II and Metrology Light Source in Berlin. For the measurements in the visible range, a setup was realised using monochromatized halogen lamp radiation and a calibrated laser power meter as reference. The measurements clearly demonstrate that the efficiency of the bolometer prototype detectors in the range from 50 eV up to ≈6 keV is close to unity; at a photon energy of 20 keV the bolometer with the thick absorber detects 80% of the photons, the one with the thin absorber about 50%. This indicates that the detectors will be well capable of measuring the plasma radiation expected from the standard ITER scenario. However, a minimum absorber thickness will be required for the high temperatures in the central plasma. At 11.56 keV, the sharp Pt-L3 absorption edge allowed to cross-check the absorber thickness by fitting the measured efficiency to the theoretically expected absorption of X-rays in a homogeneous Pt-layer. Furthermore, below 50 eV the efficiency first follows the losses due to reflectance expected for Pt, but below 10 eV it is reduced further by a factor of 2 for the thick absorber and a factor of 4 for the thin absorber. Most probably, the different histories in production, storage, and operation led to varying surface conditions and additional loss channels.

  1. Broad-band efficiency calibration of ITER bolometer prototypes using Pt absorbers on SiN membranes.

    Science.gov (United States)

    Meister, H; Willmeroth, M; Zhang, D; Gottwald, A; Krumrey, M; Scholze, F

    2013-12-01

    The energy resolved efficiency of two bolometer detector prototypes for ITER with 4 channels each and absorber thicknesses of 4.5 μm and 12.5 μm, respectively, has been calibrated in a broad spectral range from 1.46 eV up to 25 keV. The calibration in the energy range above 3 eV was performed against previously calibrated silicon photodiodes using monochromatized synchrotron radiation provided by five different beamlines of Physikalische Technische Bundesanstalt at the electron storage rings BESSY II and Metrology Light Source in Berlin. For the measurements in the visible range, a setup was realised using monochromatized halogen lamp radiation and a calibrated laser power meter as reference. The measurements clearly demonstrate that the efficiency of the bolometer prototype detectors in the range from 50 eV up to ≈6 keV is close to unity; at a photon energy of 20 keV the bolometer with the thick absorber detects 80% of the photons, the one with the thin absorber about 50%. This indicates that the detectors will be well capable of measuring the plasma radiation expected from the standard ITER scenario. However, a minimum absorber thickness will be required for the high temperatures in the central plasma. At 11.56 keV, the sharp Pt-L3 absorption edge allowed to cross-check the absorber thickness by fitting the measured efficiency to the theoretically expected absorption of X-rays in a homogeneous Pt-layer. Furthermore, below 50 eV the efficiency first follows the losses due to reflectance expected for Pt, but below 10 eV it is reduced further by a factor of 2 for the thick absorber and a factor of 4 for the thin absorber. Most probably, the different histories in production, storage, and operation led to varying surface conditions and additional loss channels.

  2. Broad-band radio circular polarization spectrum of the relativistic jet in PKS B2126-158

    Science.gov (United States)

    O'Sullivan, S. P.; McClure-Griffiths, N. M.; Feain, I. J.; Gaensler, B. M.; Sault, R. J.

    2013-10-01

    We present full Stokes radio polarization observations of the quasar PKS B2126-158 (z = 3.268) from 1 to 10 GHz using the Australia Telescope Compact Array. The source has large fractional circular polarization (CP), mc ≡ |V|/I, detected at high significance across the entire band (from 15 to 90σ per 128 MHz subband). This allows us to construct the most robust CP spectrum of an active galactic nucleus (AGN) jet to date. We find mc ∝ ν+0.60 ± 0.03 from 1.5 to 6.5 GHz, with a peak of mc ˜ 1 per cent before the spectrum turns over somewhere between 6.5 and 8 GHz, above which mc ∝ ν-3.0 ± 0.4. The fractional linear polarization (LP; p) varies from ≲0.2 to ˜1 per cent across our frequency range and is strongly anticorrelated with the fractional CP, with a best-fitting power law giving mc ∝ p-0.24 ± 0.03. This is the first clear relation between the observed LP and CP of an AGN jet, revealing the action of Faraday conversion of LP to CP within the jet. More detailed modelling in conjunction with high spatial resolution observations are required to determine the true driving force behind the conversion (i.e. magnetic twist or internal Faraday rotation). In particular determining whether the observed Faraday rotation is internal or entirely external to the jet is key to this goal. The simplest interpretation of our observations favours some internal Faraday rotation, implying that Faraday rotation-driven conversion of LP to CP is the dominant CP generation mechanism. In this case, a small amount of vector-ordered magnetic field along the jet axis is required, along with internal Faraday rotation from the low-energy end of the relativistic electron energy spectrum in an electron-proton-dominated jet.

  3. The advantage of linear viscoelastic material behavior in passive damper design-with application in broad-banded resonance dampers for industrial high-precision motion stages

    Science.gov (United States)

    Verbaan, Cornelis A. M.; Peters, Gerrit W. M.; Steinbuch, Maarten

    2017-01-01

    In this paper we demonstrate the advantage of applying viscoelastic materials instead of purely viscous materials as damping medium in mechanical dampers. Although the loss modulus decreases as function of frequency in case of viscoelastic behavior, which can be interpreted as a decrease of damping, the viscoelastic behavior still leads to an increased modal damping for mechanical structures. This advantage holds for inertial-mass-type dampers that are tuned for broad-banded resonance damping. It turns out that an increase of the storage modulus as function of frequency contributes to the effectiveness of mechanical dampers with respect to energy dissipation at different mechanical resonance frequencies. It is shown that this phenomenon is medium specific and is independent of the amount of damper mass.

  4. Investigation of Relative Time Constant Influence of Inertial Part of Superheater on Quality of Steam Temperature Control Behind Boiler in Broad Band of Loading Variations

    Directory of Open Access Journals (Sweden)

    G. T. Kulakov

    2008-01-01

    Full Text Available The paper is devoted to computational investigation of influence relative time constant of an object which changes in broad band on quality of steam temperature control behind a boiler with due account of value of regulating action in the system with PI- and PID- regulator. The simulation has been based on a single-loop automatic control system (ACS. It has been revealed that the less value of the relative time constant of an object leads to more integral control error in system with PID- regulator while operating external ACS perturbation. Decrease of numerical value of relative time constant of an object while operating external perturbation causes decrease of relative time concerning appearance of maximum dynamic control error from common relative control time.

  5. Imaging of the reaction zone in a 100 kW oil-burning furnace by use of a broad-band excimer laser

    Science.gov (United States)

    Radi, P. P.; Mischler, B.; Gerber, T.; Dreher, H.; Lehmann, B.; Ochs, M.

    1996-01-01

    The reaction zone in the hostile combustion environment of a 100 kW oil-burning furnace has been imaged by laser-induced fluorescence using a broad-band XeCl-excimer laser. Upon excitation, the averaged images obtained by using an interference filter around 320 nm (FWHM of 10 nm) show three distinct areas along the direction of the gas flow. An intense emission spreads around the spray axis and is attributed to the fluorescence of large hydrocarbons in the unburned fuel. Approximately 12 cm downstream of the nozzle, a narrow dark region is displayed suggesting the preheat zone of the combustion process where large hydrocarbons are considerably degraded. The third distinct region is characterized by a strong onset of the fluorescence intensity localized downstream of the dark region. This feature is strongly suppressed by replacing the interference filter by a broad-band transmission filter passing light from 350 to 500 nm. Since OH strongly absorbs at the laser wavelength and its fluorescence is significantly lower above 345 nm, the findings imply that the major contribution to the observed intensity in this region originates from the OH radical. This molecule reaches its maximum concentration immediately downstream of the flame front. However, a contribution from other flame species fluorescing around 320 nm cannot be ruled out. Nevertheless, the combined spatial and spectral information obtained imply that the reaction zone of the combustion process can be localized accurately. The results are compared with simultaneously performed numerical simulations of the burner and are in reasonable agreement.

  6. Evidence for a change in the radiation mechanism in the hard state of GRO J1655-40. Hysteresis in the broad-band noise components

    CERN Document Server

    Reig, P; Sobolewska, M A; Malzac, J

    2013-01-01

    We have analysed RXTE archival data to study the aperiodic variability of the black-hole binary GRO J1655-40 during the hard state of the 2005 outburst. We computed the 0.008-64 Hz power spectral density during the rise and decay of the 2005 outburst, and we found that they were reasonably well modelled by the sum of two, broad Lorenztian functions in most cases (plus a narrow QPO) which correspond to three different variability components. Our aim is to study the evolution of the timing properties of the source during the outburst, by studying the correlation between the characteristics of the broad-band noise components in the power spectra and the source luminosity. Our results suggest that the whole power spectrum shifts to high (low) frequencies as the source luminosity increases (decreases), in agreement with previous studies of other black hole binaries. However, we also detect a strong "hysteresis" pattern in the "frequency-luminosity" plots, and show that the "critical" luminosity limit, above which ...

  7. Virial Black Hole Mass Estimates for 280,000 AGNs from the SDSS Broad-Band Photometry and Single Epoch Spectra

    CERN Document Server

    Kozłowski, Szymon

    2016-01-01

    We use the Sloan Digital Sky Survey (SDSS) Quasar Data Release 12 (DR12Q), containing nearly 300,000 AGNs, to calculate the monochromatic luminosities at 5100\\AA, 3000\\AA, and 1350\\AA, derived from the broad-band extinction-corrected SDSS magnitudes. After matching them to their counterparts based on spectra and published in the SDSS Quasar Data Release 7 (DR7Q), we find perfect correlations with minute mean offsets ($\\sim$0.01 dex) and dispersions of differences of 0.11, 0.10, 0.12 dex, respectively, across a 2.5 dex luminosity range. We then estimate the active galactic nuclei (AGNs) black hole masses using the broad line region radius--luminosity relations and the FWHM of the MgII and CIV emission lines, to provide a catalog of 283,032 virial black hole mass estimates (132,451 for MgII, 213,068 for CIV, and 62,487 for both) along with the bolometric luminosity and the Eddington ratio estimates for $0.1

  8. A Decade of Short-duration Gamma-ray Burst Broad-band Afterglows: Energetics, Circumburst Densities, and Jet Opening Angles

    CERN Document Server

    Fong, Wen-fai; Margutti, Raffaella; Zauderer, B Ashley

    2015-01-01

    We present a comprehensive catalog and analysis of broad-band afterglow observations for 103 short-duration gamma-ray bursts (GRBs), comprised of all short GRBs from November 2004 to March 2015 with prompt follow-up observations in the X-ray, optical, near-infrared and/or radio bands. These afterglow observations have uncovered 71 X-ray detections, 30 optical/NIR detections, and 4 radio detections. Employing the standard afterglow synchrotron model, we perform joint probability analyses for a subset of 38 short GRBs with well-sampled light curves to infer the burst isotropic-equivalent energies and circumburst densities. For this subset, we find median isotropic-equivalent gamma-ray and kinetic energies of E_gamma,iso~2x10^51 erg, and E_K,iso~(1-3)x10^51 erg, respectively, depending on the values of the model input parameters. We further find that short GRBs occur in low-density environments, with a median density of n~(3-15)x10^-3 cm^-3, and that ~80-95% of bursts have densities of less than 1 cm^-3. We inve...

  9. High-resolution Fourier-transform cavity-enhanced absorption spectroscopy in the near-infrared using an incoherent broad-band light source.

    Science.gov (United States)

    Orphal, Johannes; Ruth, Albert A

    2008-11-10

    An incoherent broad-band cavity-enhanced absorption (IBB-CEA) set-up was used in combination with a Fourier-transform (FT) spectrometer in order to explore the potential of this technique for high-resolution molecular spectroscopy in the near-infrared region. Absorption spectra of overtone bands of CO2, OCS, and HD18O were measured between 5800 and 7000 cm(-1) using a small sampling volume (1100 cm3, based on a 90 cm cavity length). The quality of the spectra in this study is comparable to that obtained with Fourier transform spectrometers employing standard multi-pass reflection cells, which require substantially larger sampling volumes. High-resolution methods such as FT-IBB-CEAS also provide an elegant way to determine effective mirror reflectivities (R(eff), i.e. a measure of the inherent overall cavity loss) by using a calibration gas with well-known line strengths. For narrow absorption features and non-congested spectra this approach does not even require a zero-absorption measurement with the empty cavity. Absolute cross-sections or line strengths of a target species can also be determined in one single measurement, if gas mixtures with known partial pressures are used. This feature of FT-IBB-CEAS reduces systematic errors significantly; it is illustrated based on CO2 as calibration gas.

  10. 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.

  11. Quasi-simultaneous XMM-Newton and VLA observation of the non-thermal radio emitter HD\\168112 (O5.5III(f^+))

    CERN Document Server

    De Becker, M; Blomme, R; Waldron, W L; Sana, H; Pittard, J M; Eenens, P; Stevens, I R; Runacres, M C; Van Loo, S; Pollock, A M T

    2004-01-01

    We report the results of a multiwavelength study of the non-thermal radio emitter HD168112 (O5.5III(f^+)). The detailed analysis of two quasi-simultaneous XMM-Newton and VLA observations reveals strong variability of this star both in the X-ray and radio ranges. The X-ray observations separated by five months reveal a decrease of the X-ray flux of ~30%. The radio emission on the other hand increases by a factor 5-7 between the two observations obtained roughly simultaneously with the XMM-Newton pointings. The X-ray data reveal a hard emission that is most likely produced by a thermal plasma at kT ~2-3 keV while the VLA data confirm the non-thermal status of this star in the radio waveband. Comparison with archive X-ray and radio data confirms the variability of this source in both wavelength ranges over a yet ill defined time scale. The properties of HD168112 in the X-ray and radio domain point towards a binary system with a significant eccentricity and an orbital period of a few years. However, our optical s...

  12. Study and Control of Various Corona Modes in an Atmospheric Pressure Weakly Ionized Plasma Reactor Using a Current Sensor Characterized by a Broad Frequency Band

    Science.gov (United States)

    Islam, Rokibul; Pedrow, Patrick; Lekobou, William; Englund, Karl

    2013-09-01

    A broad band current sensor is being used to monitor the various phenomena (primary streamers, secondary streamers, back corona, etc.) associated with an atmospheric pressure needle-array-to-grounded-screen corona discharge. The reactor consists of a PVC tube and the needle array consists of nickel coated steel electrodes with radius of curvature about 50 μ . The grounded screen is made from stainless steel mesh and applied voltage has a frequency of 60 Hz with an RMS value ranging from 0 to 10 kV. The voltage sensor is a resistive divider and the current sensor is a viewing resistor with value 50 Ω. The feed gas stream is presently (argon + acetylene) or (argon + oxygen) with the argon acting as carrier gas and the acetylene and oxygen acting as precursor gases. Voltage and current are captured with a LeCroy 9350AL 500MHz oscilloscope and analyzed with Matlab using digital signal processing algorithms. The goals of the research are 1) to measure reactor electrical power on a real time basis; 2) to provide real time control of the applied voltage and thus avoid spark conditions; and 3) to identify the various corona modes present in the reactor. Processing of substrates takes place downstream from the grounded screen, outside of the harsh corona discharge environment.

  13. Broad-band spectrophotometry of the hot Jupiter HAT-P-12b from the near-UV to the near-IR

    CERN Document Server

    Mallonn, M; Weingrill, J; von Essen, C; Strassmeier, K G; Piotto, G; Pagano, I; Scandariato, G; Csizmadia, Sz; Herrero, E; Sada, P V; Dhillon, V S; Marsh, T R; Künstler, A; Bernt, I; Granzer, T

    2015-01-01

    The detection of trends or gradients in the transmission spectrum of extrasolar planets is possible with observations at very low spectral resolution. Transit measurements of sufficient accuracy using selected broad-band filters allow for an initial characterization of the atmosphere of the planet. We obtained time series photometry of 20 transit events and analyzed them homogeneously, along with eight light curves obtained from the literature. In total, the light curves span a range from 0.35 to 1.25 microns. During two observing seasons over four months each, we monitored the host star to constrain the potential influence of starspots on the derived transit parameters. We rule out the presence of a Rayleigh slope extending over the entire optical wavelength range, a flat spectrum is favored for HAT-P-12b with respect to a cloud-free atmosphere model spectrum. A potential cause of such gray absorption is the presence of a cloud layer at the probed latitudes. Furthermore, in this work we refine the transit pa...

  14. Modelling the variable broad-band optical/UV/X-ray spectrum of PG1211+143: Implications for the ionized outflow

    CERN Document Server

    Papadakis, I E; Panagiotou, C

    2016-01-01

    We present the results from a detailed analysis of the 2007 Swift monitoring campaign of the quasar PG1211+143. We constructed broad-band, optical/UV/X-ray spectral energy distributions over three X-ray flux intervals. We fitted them with a model which accounts for the disc and the X-ray coronal emission and the warm absorber (well established in this source). The three flux spectra are well fitted by the model we considered. The disc inner temperature remains constant at ~2 eV, while X-rays are variable both in spectral slope and normalization. The absorber covers almost 90% of the central source. It is outflowing with a velocity less than 2.3*10^4 km/s (3sigma upper limit), and has a column density of ~10^23.2. Its ionization parameter varies by a factor of 1.6, and it is in photo-ionizing equilibrium with the ionizing flux. It is located at a distance of less than 0.35 pc from the central source and its relative thickness, DR/R is less than 0.1. The absorber' s ionization parameter variations can explain t...

  15. Sensitivity of broad-band ground-motion simulations to earthquake source and Earth structure variations: an application to the Messina Straits (Italy)

    KAUST Repository

    Imperatori, W.

    2012-03-01

    In this paper, we investigate ground-motion variability due to different faulting approximations and crustal-model parametrizations in the Messina Straits area (Southern Italy). Considering three 1-D velocity models proposed for this region and a total of 72 different source realizations, we compute broad-band (0-10 Hz) synthetics for Mw 7.0 events using a fault plane geometry recently proposed. We explore source complexity in terms of classic kinematic (constant rise-time and rupture speed) and pseudo-dynamic models (variable rise-time and rupture speed). Heterogeneous slip distributions are generated using a Von Karman autocorrelation function. Rise-time variability is related to slip, whereas rupture speed variations are connected to static stress drop. Boxcar, triangle and modified Yoffe are the adopted source time functions. We find that ground-motion variability associated to differences in crustal models is constant and becomes important at intermediate and long periods. On the other hand, source-induced ground-motion variability is negligible at long periods and strong at intermediate-short periods. Using our source-modelling approach and the three different 1-D structural models, we investigate shaking levels for the 1908 Mw 7.1 Messina earthquake adopting a recently proposed model for fault geometry and final slip. Our simulations suggest that peak levels in Messina and Reggio Calabria must have reached 0.6-0.7 g during this earthquake.

  16. Comparison of broad band time series recorded parallel by FGI type interferometric water level and Lippmann type pendulum tilt meters at Conrad observatory, Austria

    Science.gov (United States)

    Ruotsalainen, Hannu; Papp, Gabor; Leonhardt, Roman; Ban, Dora; Szücs, Eszter; Benedek, Judith

    2016-04-01

    The Finnish Geodetic Institute (FGI) the progenitor of Finnish Geospatial Research Institute of NLS designed and built a 5.5m long prototype of interferometric water level tiltmeter (iWT) in early 2014. Geodetic and Geophysical Institute (GGI), Sopron, Hungary bought the instrument and started tilt measurement in August 2014 at the Conrad observatory (COBS), Austria to monitor geodynamical phenomena like microseisms, free oscillations of the Earth, earth tides, mass loading effects and crustal deformations in cooperation with Austrian Central Institute for Meteorology and Geodynamics (ZAMG) and the FGI. On the July 16 2015 a Lippmann-type 2D tilt sensor (LTS) was also installed by GGI on the 6 m long pier where iWT was set up previously. This situation opens a possibility to do broad band (from secular to seismic variations up to 15 Hz) geophysical signal analysis comparing the responses of long (several meters) and short (a few decimeters) base instruments implementing different physical principles (relative height change of a level surface and inclination change of the plumb line). The characteristics of the sensors are studied by the evaluation of the spectra of recorded signals dominated by microseisms. The iWT has internal interferometric calibration and it can be compared to Lippmanns tilt meter one. Both instruments show good long term ( > 1 day) stability when earth tides and ocean and air mass loading tilts are modelled.

  17. Contamination of Broad-Band Photometry by Nebular Emission in High Redshift Galaxies: Investigations with Keck's MOSFIRE Near-Infrared Spectrograph

    CERN Document Server

    Schenker, Matthew A; Konidaris, Nick P; Stark, Daniel P

    2013-01-01

    Earlier work has raised the potential importance of nebular emission in the derivation of the physical characteristics of high redshift Lyman break galaxies. Within certain redshift ranges, and especially at z ~ 6-7, such lines may be strong enough to reduce estimates of the stellar masses and ages of galaxies compared those derived assuming broad-band photometry represents stellar light alone. To test this hypothesis at the highest redshifts where such lines can be probed with ground-based facilities, we examine the near-infrared spectra of a representative sample of 20 3.0 < z < 3.8 Lyman break galaxies using the newly-commissioned MOSFIRE near-infrared spectrograph at the Keck I telescope. We use this data to derive the rest-frame equivalent widths (EW) of [O III] emission and show that these are comparable to estimates derived using the SED fitting technique introduced for sources of known redshift by Stark et al (2013). Although our current sample is modest, its [O III] EW distribution is consisten...

  18. Discovery of Extremely Broad Balmer Absorption Lines in SDSS J152350.42+391405.2

    CERN Document Server

    Zhang, Shaohua; Shi, Xiheng; Shu, Xinwen; Liu, Wenjuan; Ji, Tuo; Jiang, Peng; Sun, Luming; Zhou, Junyan; Pan, Xiang

    2015-01-01

    We present the discovery of Balmer line absorption from H$\\alpha$ to H$\\gamma$ in an iron low-ionization broad absorption line (FeLoBAL) quasar SDSS J152350.42+391405.2 (hereafter J1523), by the quasi-simultaneous optical and near-infrared spectroscopy. The Balmer line absorption is at $z_{absor}$ = 0.6039 +/-0.0021 and blueshifted by v=10,353 km/s with respect to the Balmer emission lines. All Balmer BALs have uniform absorption profile with the widths of $\\Delta$ v ~12,000 km/s. We also found the absorption trough in He 1* $\\lambda$10830 with the same velocity and width in the H-band TripleSpec spectrum of J1523. This object is only the tenth active galactic nucleus known to exhibit non-stellar Balmer absorption, and also the case with the highest velocity and broadest Balmer absorption lines which have ever been found. A CLOUDY analysis shows that the absorbers require an gas density of $log_{10} n_ e (cm^{-3})=9$ and an ionization parameter of $log_{10} U=-1.0$. They locate at a distance of ~0.2 pc from t...

  19. Broad-band spectrophotometry of the hot Jupiter HAT-P-12b from the near-UV to the near-IR

    Science.gov (United States)

    Mallonn, M.; Nascimbeni, V.; Weingrill, J.; von Essen, C.; Strassmeier, K. G.; Piotto, G.; Pagano, I.; Scandariato, G.; Csizmadia, Sz.; Herrero, E.; Sada, P. V.; Dhillon, V. S.; Marsh, T. R.; Künstler, A.; Bernt, I.; Granzer, T.

    2015-11-01

    Context. The detection of trends or gradients in the transmission spectrum of extrasolar planets is possible with observations at very low spectral resolution. Transit measurements of sufficient accuracy using selected broad-band filters allow for an initial characterization of the atmosphere of the planet. Aims: We want to investigate the atmosphere of the hot Jupiter HAT-P-12b for an increased absorption at the very blue wavelength regions caused by scattering. Furthermore, we aim for a refinement of the transit parameters and the orbital ephemeris. Methods: We obtained time series photometry of 20 transit events and analyzed them homogeneously, along with eight light curves obtained from the literature. In total, the light curves span a range from 0.35 to 1.25 microns. During two observing seasons over four months each, we monitored the host star to constrain the potential influence of starspots on the derived transit parameters. Results: We rule out the presence of a Rayleigh slope extending over the entire optical wavelength range, a flat spectrum is favored for HAT-P-12b with respect to a cloud-free atmosphere model spectrum. A potential cause of such gray absorption is the presence of a cloud layer at the probed latitudes. Furthermore, in this work we refine the transit parameters, the ephemeris and perform a TTV analysis in which we found no indication for an unseen companion. The host star showed a mild non-periodic variability of up to 1%. However, no stellar rotation period could be detected to high confidence.

  20. Seismic source study of the 1989, October 29, Chenoua (Algeria earthquake from aftershocks, broad-band and strong ground motion records

    Directory of Open Access Journals (Sweden)

    L. Rivera

    2003-06-01

    Full Text Available The broad-band teleseismics records of the earthquake of October 29,1989 in Algeria (MW = 6.0 allow a detailed study of the rupture process of this earthquake. The focal mechanism obtained by P and SH modeling corresponds to reverse faulting with a small amount of left-lateral movement along a fault striking 246° and dipping 56°. The rupture is found to be complex with two sub-events separated in time but occurring on the same plane. The lowfrequency records of an accelerometer located some 25 km to the west of the main shock are also better fi tted when the rupture is composed of a double pulse. In the two cases, there is strong evidence for the rupture to propagate from south-west towards north-east.The relocalisation of the main shock by using a master-event technique and the data from Italian and Spanish stations led to the same conclusions. Soon after the main event, a temporary seimic network was installed in the epicentral area. The aftershock clouds defi ne a SW-NE fault dipping to the NW compatible with the results of the modelisations of the teleseismic body-waves and the accelerogram. The focal mechanisms correspond mainly to reverse faulting. The maximum principal direction of the stress tensor obtained from the inversion is about N-S and the minimum is vertical, typical of a compressive regime. The Chenoua earthquake took place on a fault which was not recognized as active. Repeated comparable seismic events on this fault and on the fault that borders the massif to the south explain this intriguing topographic feature.

  1. Broad-band strong motion simulations coupling k-square kinematic source models with empirical Green's functions: the 2009 L'Aquila earthquake

    Science.gov (United States)

    Del Gaudio, Sergio; Causse, Mathieu; Festa, Gaetano

    2015-10-01

    The use of simulated accelerograms may improve the evaluation of the seismic hazard when an accurate modelling of both source and propagation is performed. In this paper, we performed broad-band simulations of the 2009, M 6.3 L'Aquila earthquake, coupling a k-2 kinematic model for the seismic source with empirical Green's functions (EGFs) as propagators. We extracted 10 EGFs candidates from a database of aftershocks satisfying quality criteria based on signal-to-noise ratio, fault proximity, small magnitude, similar focal mechanism and stress drop. For comparison with real observations, we also derived a low-frequency kinematic model, based on inversion of ground displacement as integrated from strong motion data. Kinematic properties of the inverted model (rupture velocity, position of the rupture nucleation, low-frequency slip and roughness degree of slip heterogeneity) were used as constraints in the k-2 model, to test the use of a single specific EGF against the use of the whole set of EGFs. Comparison to real observations based on spectral and peak ground acceleration shows that the use of all available EGFs improves the fit of simulations to real data. Moreover the epistemic variability related to the selection of a specific EGF is significantly larger (two to three times) than recent observations of between event variability, that is the variability associated with the randomness of the rupture process. We finally performed `blind' simulations releasing all the information on source kinematics and only considering the fault geometry and the magnitude of the target event as known features. We computed peak ground acceleration, acceleration Fourier and response spectra. Simulations follow the same trend with distance as real observations. In most cases these latter fall within one sigma from predictions. Predictions with source parameters constrained at low frequency do not perform better than `blind' simulations, showing that extrapolation of the low

  2. Dynamics of the 2007 Eruptions of Piton de la Fournaise and the Related Caldera Collapse from a Single Very Broad-band Seismic Station

    Science.gov (United States)

    Fontaine, Fabrice R.; Roult, Geneviève; Michon, Laurent; Barruol, Guilhem; Ferrazzini, Valérie; Di Muro, Andrea; Reymond, Dominique; Peltier, Aline; Staudacher, Thomas

    2014-05-01

    Seismic records from the RER very broad-band seismic station (La Réunion Island) belonging to the GEOSCOPE network are investigated to understand the eruptive succession (February to May) of Piton de la Fournaise and the caldera collapse episode of April 2007. Data first indicate that the short-lived, small volume, summit eruption of February 18 occurred during a phase of continuous inflation initiated in January 2007. Inflation decelerated around 2 weeks before a second short-lived small volume eruption on March 30-31 on the SE flank, almost simultaneous with a sudden, large deflation of the edifice. Deflation rate, which had stabilized at a relatively low level, increased anew on April 1 while no magma was emitted, followed on April 2 by a more distant and one of the most voluminous eruptions of the last two centuries at La Réunion Island. The RER station shows that very long period (VLP) and ultra long period (ULP) events developed during this period. Seven ULP events preceded the caldera collapse and 48 ones occurred during the caldera collapse over 9 days, most of which during the first 30 hours. A thorough examination of the seismic signals corrected for tide effects shows that each collapse event was coeval with VLP and ULP signals. Each individual collapse showed similar ULP and VLP signals characterized by periods of ~ 500 s and ~ 7 s, respectively. The back-azimuth of most ULP signals related to the caldera collapse points clearly toward the Dolomieu caldera. The strikingly constant duration of the VLP signals (around 20 s) related to the collapse events and their occurrence before the collapse initiation suggest a physical control of the volcanic edifice. Waveforms and spectrograms of the various caldera collapse events show very homogeneous patterns, suggesting a similar and repeating volcano-tectonic process for the formation of the VLP signals events. Although tilt may be responsible of part of the ULP signals observed during the collapse events, we

  3. Ultrathin, high-efficiency, broad-band, omni-acceptance, organic solar cells enhanced by plasmonic cavity with subwavelength hole array.

    Science.gov (United States)

    Chou, Stephen Y; Ding, Wei

    2013-01-14

    Three of central challenges in solar cells are high light coupling into solar cell, high light trapping and absorption in a sub-absorption-length-thick active layer, and replacement of the indium-tin-oxide (ITO) transparent electrode used in thin-film devices. Here, we report a proposal and the first experimental study and demonstration of a new ultra-thin high-efficiency organic solar cell (SC), termed "plasmonic cavity with subwavelength hole-array (PlaCSH) solar cell", that offers a solution to all three issues with unprecedented performances. The ultrathin PlaCSH-SC is a thin plasmonic cavity that consists of a 30 nm thick front metal-mesh electrode with subwavelength hole-array (MESH) which replaces ITO, a thin (100 nm thick) back metal electrode, and in-between a polymer photovoltaic active layer (P3HT/PCBM) of 85 nm thick (1/3 average absorption-length). Experimentally, the PlaCSH-SCs have achieved (1) light coupling-efficiency/absorptance as high as 96% (average 90%), broad-band, and Omni acceptance (light coupling nearly independent of both light incident angle and polarization); (2) an external quantum efficiency of 69% for only 27% single-pass active layer absorptance; leading to (3) a 4.4% power conversion efficiency (PCE) at standard-solar-irradiation, which is 52% higher than the reference ITO-SC (identical structure and fabrication to PlaCSH-SC except MESH replaced by ITO), and also is among the highest PCE for the material system that was achievable previously only by using thick active materials and/or optimized polymer compositions and treatments. In harvesting scattered light, the Omni acceptance can increase PCE by additional 81% over ITO-SC, leading to a total 175% increase (i.e. 8% PCE). Furthermore, we found that (a) after formation of PlaCSH the light reflection and absorption by MESH are reduced by 2 to 6 fold from the values when it is alone; and (b) the sheet resistance of a 30 nm thick MESH is 2.2 ohm/sq or less-4.5 fold or more lower

  4. Multiwavelength campaign on Mrk 509 XV. A global modeling of the broad emission lines in the Optical, UV and X-ray bands

    CERN Document Server

    Costantini, E; Kaastra, J S; Bianchi, S; Branduardi-Raymont, G; Cappi, M; De Marco, B; Ebrero, J; Mehdipour, M; Petrucci, P -O; Paltani, S; Ponti, G; Steenbrugge, K C; Arav, N

    2016-01-01

    We model the broad emission lines present in the optical, UV and X-ray spectra of Mrk 509, a bright type 1 Seyfert galaxy. The broad lines were simultaneously observed during a large multiwavelength campaign, using the XMM-Newton-OM for the optical lines, HST-COS for the UV lines and XMM-Newton-RGS and Epic for the X-ray lines respectively. We also used FUSE archival data for the broad lines observed in the far-ultra-violet. The goal is to find a physical connection among the lines measured at different wavelengths and determine the size and the distance from the central source of the emitting gas components. We used the "Locally optimally emission Cloud" (LOC) model which interprets the emissivity of the broad line region (BLR) as regulated by powerlaw distributions of both gas density and distances from the central source. We find that one LOC component cannot model all the lines simultaneously. In particular, we find that the X-ray and UV lines likely may originate in the more internal part of the AGN, at ...

  5. Analysis of shallow-water experimental acoustic data including a comparison with a broad-band normal-mode-propagation model

    NARCIS (Netherlands)

    Simons, D.G.; McHugh, R.; Snellen, M.; McCormick, N.H.; Lawson, E.A.

    2001-01-01

    Channel temporal variability, resulting from fluctuations in oceanographic parameters, is an important issue for reliable communications in shallow-water-long-range acoustic propagation. As part of an acoustic model validation exercise, audio-band acoustic data and oceanographic data were collected

  6. A broad slow frequencies band and high slowing down factor by using one-dimensional hybrid periodic/Fibonacci photonic crystals

    Energy Technology Data Exchange (ETDEWEB)

    Ben Ali, N; Kanzari, M, E-mail: naimgi2@yahoo.fr [Photovoltaic and Semiconductor Materials Laboratory, El-Manar University-ENIT PO Box 37, Le belvedere 1002-Tunis (Tunisia)

    2010-11-15

    By using a theoretical model based on Transfer Matrix Method (TMM) for normal incidence simulator, and for serial (S) polarisation, the slowing of light in one-dimensional (1D) hybrid (Fibonacci{sub 1}/periodic/Fibonacci{sub 2}) photonic crystals is studied at visible frequency band. Effects of the periodicity, the non-periodicity and the number of layers of each photonic structure on the slowing down of light are discussed. The higher slowing down factors was obtained by the hybrid Fibonacci{sub 1}/periodic/Fibonacci{sub 2} structures. This slowing down factors is greater than those corresponding to the periodic, the Fibonacci, the Thue-Morse and the Cantor band-gap structures. In addition this hybrid structure gives the possibility to slowing several frequencies

  7. Lattice dynamics and broad-band dielectric properties of multiferroic Pb(Fe{sub 1/2}Nb{sub 1/2})O{sub 3} ceramics

    Energy Technology Data Exchange (ETDEWEB)

    Mackeviciute, R.; Greicius, S.; Grigalaitis, R.; Banys, J. [Faculty of Physics, Vilnius University, Sauletekio av. 9, III b. 817, LT-10222 Vilnius (Lithuania); Goian, V.; Nuzhnyy, D.; Kamba, S., E-mail: kamba@fzu.cz [Institute of Physics, The Czech Academy of Sciences, Na Slovance 2, 182 21 Prague 8 (Czech Republic); Holc, J. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2015-02-28

    Complex dielectric properties of Pb(Fe{sub 1/2}Nb{sub 1/2})O{sub 3} ceramics were investigated in a broad frequency range from 100 Hz up to 90 THz. A broad dielectric anomaly was observed near the temperature of the ferroelectric phase transition (T{sub C1} = 376 K). Below 1 MHz, the anomaly is strongly influenced by conductivity of the sample, but higher frequency data taken up to 81 MHz reveal a broad and frequency independent peak at T{sub C1} typical for a diffuse ferroelectric phase transition. Surprisingly, dielectric permittivity measured at 37 GHz exhibits a peak shifted by 25 K above T{sub C1}, which indicates polar nanoregions with dynamics in microwave frequency region. A dielectric relaxation, which appears in THz region below 700 K, slows down towards T{sub C1} and again hardens below T{sub C2} = 356 K. This central mode drives both phase transitions, so they belong to order–disorder type, although the polar phonons exhibit anomalies near both phase transitions. In the paraelectric phase, infrared reflectivity spectra correspond to local Fm3{sup ¯}m structure due to short-range chemical ordering of Fe and Nb cations on the B perovskite sites. Moreover, each polar phonon is split due to two different cations on the B sites. Recently, Manley et al. [Nat. Commun. 5, 3683 (2014)] proposed a new mechanism of creation of polar nanoregions in relaxor ferroelectrics. They argued, based on their inelastic neutron scattering studies of PMN–PT, that the TO1 phonon is split and interaction of both components gives rise to so called Anderson phonon localization, which can produce regions of trapped standing waves and these waves induce polar nanoregions in relaxors. We cannot exclude or confirm this mechanism, but we show that the splitting of polar phonons is a common feature for all complex perovskites with relaxor ferroelectric behavior and it can be also observed in canonical ferroelectric BaTiO{sub 3}, where the soft mode is split in

  8. Lattice dynamics and broad-band dielectric properties of multiferroic Pb(Fe1/2Nb1/2)O3 ceramics

    Science.gov (United States)

    Mackeviciute, R.; Goian, V.; Greicius, S.; Grigalaitis, R.; Nuzhnyy, D.; Holc, J.; Banys, J.; Kamba, S.

    2015-02-01

    Complex dielectric properties of Pb(Fe1/2Nb1/2)O3 ceramics were investigated in a broad frequency range from 100 Hz up to 90 THz. A broad dielectric anomaly was observed near the temperature of the ferroelectric phase transition (TC1 = 376 K). Below 1 MHz, the anomaly is strongly influenced by conductivity of the sample, but higher frequency data taken up to 81 MHz reveal a broad and frequency independent peak at TC1 typical for a diffuse ferroelectric phase transition. Surprisingly, dielectric permittivity measured at 37 GHz exhibits a peak shifted by 25 K above TC1, which indicates polar nanoregions with dynamics in microwave frequency region. A dielectric relaxation, which appears in THz region below 700 K, slows down towards TC1 and again hardens below TC2 = 356 K. This central mode drives both phase transitions, so they belong to order-disorder type, although the polar phonons exhibit anomalies near both phase transitions. In the paraelectric phase, infrared reflectivity spectra correspond to local F m 3 ¯ m structure due to short-range chemical ordering of Fe and Nb cations on the B perovskite sites. Moreover, each polar phonon is split due to two different cations on the B sites. Recently, Manley et al. [Nat. Commun. 5, 3683 (2014)] proposed a new mechanism of creation of polar nanoregions in relaxor ferroelectrics. They argued, based on their inelastic neutron scattering studies of PMN-PT, that the TO1 phonon is split and interaction of both components gives rise to so called Anderson phonon localization, which can produce regions of trapped standing waves and these waves induce polar nanoregions in relaxors. We cannot exclude or confirm this mechanism, but we show that the splitting of polar phonons is a common feature for all complex perovskites with relaxor ferroelectric behavior and it can be also observed in canonical ferroelectric BaTiO3, where the soft mode is split in paraelectric phase due to a strong lattice anharmonicity.

  9. Synthesis and luminescence properties of a broad-band red phosphor Ca{sub 3}Si{sub 2}O{sub 7}:Eu{sup 2+} for warm white light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Qian Fengjiao [College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Fu Renli, E-mail: renlifu@nuaa.edu.cn [College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China); Agathopoulos, Simeon [Materials Science and Engineering Department, University of Ioannina, GR-451 10 Ioannina (Greece); Gu Xiguang; Song Xiufeng [College of Materials Science and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 210016 (China)

    2012-01-15

    Single-phase broad-band red-emitting Ca{sub 3}Si{sub 2}O{sub 7}:Eu{sup 2+} phosphors, with photoluminescence features that qualify them as candidates for white light-emitting diodes applications, were successfully synthesized via a modified solid-state reaction method that employed H{sub 3}BO{sub 3} as a flux. The phosphors produced have an intense broad red emission band, with a peak at 603 nm, a full width at half maximum of 110 nm, and color coordinates of (0.550, 0.438). Concentration quenching occurred at 0.01 mol Eu{sup 2+}. The discussion of the results shows that Eu{sup 2+} ions should be accommodated at the Ca-sites of the lattice, dipole-dipole interactions should predominantly govern the energy transfer mechanism among them, and the critical distance between them is {approx}31 A. - Highlights: > Pure Ca{sub 3}Si{sub 2}O{sub 7}:Eu{sup 2+} phosphor was successfully synthesized by adding H{sub 3}BO{sub 3} . > Effects of H{sub 3}BO{sub 3} on phase formation and emission intensity were presented. > Luminescence properties in conjunction with Ca{sub 3}Si{sub 2}O{sub 7} structure were studied. > Energy transfer mechanism of Eu{sup 2+} and its critical distance were proposed.

  10. Optimal design and loss mechanism analysis of microwave absorbing unidirectional SiC fiber composites with broad absorption band and good polarization stability

    Science.gov (United States)

    Wan, Guangchao; Jiang, Jianjun; He, Yun; Bie, Shaowei

    2016-04-01

    A microwave-absorbing unidirectional SiC fiber composite with wide absorption and good polarization stability was designed by genetic algorithm. The anisotropic nature of unidirectional fiber composites was considered in the design by characterizing tensor permittivity. This special composite is composed of two kinds of SiC fibers that separately exhibit relatively high conductivity and low conductivity. The electromagnetic loss mechanism of this composite was examined for polarizations that differ in the electric field of the incident wave, applied either in the direction of the fiber or in the transverse direction, perpendicular to the fibers. For both polarizations, the absorption band of our composite can reach 6 GHz and the lowest microwave reflectivity was about -20 dB over a range of 8-18 GHz. When the electric field is polarized parallel to fibers, strong coupling among the high-conductivity fibers can induce a strong current and thus efficiently dissipate the electromagnetic energy. When the electric field is polarized perpendicular to fibers, the electromagnetic loss mechanism in the composite resembles the electric energy loss in capacitors and currents in the transverse direction are obstructed by the fibers resulting in attenuation of the electromagnetic energy in the matrix.

  11. Wide-field broad-band radio imaging with phased array feeds: a pilot multi-epoch continuum survey with ASKAP-BETA

    Science.gov (United States)

    Heywood, I.; Bannister, K. W.; Marvil, J.; Allison, J. R.; Ball, L.; Bell, M. E.; Bock, D. C.-J.; Brothers, M.; Bunton, J. D.; Chippendale, A. P.; Cooray, F.; Cornwell, T. J.; De Boer, D.; Edwards, P.; Gough, R.; Gupta, N.; Harvey-Smith, L.; Hay, S.; Hotan, A. W.; Indermuehle, B.; Jacka, C.; Jackson, C. A.; Johnston, S.; Kimball, A. E.; Koribalski, B. S.; Lenc, E.; Macleod, A.; McClure-Griffiths, N.; McConnell, D.; Mirtschin, P.; Murphy, T.; Neuhold, S.; Norris, R. P.; Pearce, S.; Popping, A.; Qiao, R. Y.; Reynolds, J. E.; Sadler, E. M.; Sault, R. J.; Schinckel, A. E. T.; Serra, P.; Shimwell, T. W.; Stevens, J.; Tuthill, J.; Tzioumis, A.; Voronkov, M. A.; Westmeier, T.; Whiting, M. T.

    2016-04-01

    The Boolardy Engineering Test Array is a 6 × 12 m dish interferometer and the prototype of the Australian Square Kilometre Array Pathfinder (ASKAP), equipped with the first generation of ASKAP's phased array feed (PAF) receivers. These facilitate rapid wide-area imaging via the deployment of simultaneous multiple beams within an ˜30 deg2 field of view. By cycling the array through 12 interleaved pointing positions and using nine digitally formed beams, we effectively mimic a traditional 1 h × 108 pointing survey, covering ˜150 deg2 over 711-1015 MHz in 12 h of observing time. Three such observations were executed over the course of a week. We verify the full bandwidth continuum imaging performance and stability of the system via self-consistency checks and comparisons to existing radio data. The combined three epoch image has arcminute resolution and a 1σ thermal noise level of 375 μJy beam-1, although the effective noise is a factor of ˜3 higher due to residual sidelobe confusion. From this we derive a catalogue of 3722 discrete radio components, using the 35 per cent fractional bandwidth to measure in-band spectral indices for 1037 of them. A search for transient events reveals one significantly variable source within the survey area. The survey covers approximately two-thirds of the Spitzer South Pole Telescope Deep Field. This pilot project demonstrates the viability and potential of using PAFs to rapidly and accurately survey the sky at radio wavelengths.

  12. The Design of the Broad-Band Microwave Amplifier DC Bias Circuits%一种宽带微波放大器偏置电路的设计

    Institute of Scientific and Technical Information of China (English)

    姚波; 张永慧

    2009-01-01

    本文利用微波平面结构谐振模式情况下场等效的方法,对单扇形微带传输线电路进行了分析,并在此基础上介绍了一种宽带直流偏置电路的分析和设计方法.此种形式的偏置电路应用于一种C波段的微波放大器上,仿真和实验结果证明了这种宽带直流偏置电路是有效的.%In this paper, the analysis of the microstrip radial-line stubs is presented. The method is based on the electromagnetic field expansion in terms of resonant modes of the planar structure. Using this theory, the analysis and design of a kind of broad-band de bias circuit is presented. The bias circuit is used in a C-Band microwave amplifier. Simulation and testing result prove that the bias circuit is good.

  13. Noise in Broad-Band Hydrophones

    Science.gov (United States)

    1975-05-01

    accolertion and pressure in water A• / , ILLUS’.RATIONrs (coat 1d ) 22 Aaplifiar and titrisi nOise backgnnumd JMT 1 BUTION’ . ... . .. t. .* .*. . *. . *** o. o...Then, Z (fros equation (49c)) W 2 1 S2 2n,- - 2(69)QU 2ni(69 This appriisate relationship has boon used in the following ezW , even wtare the element is

  14. Broad Band/MILS Listening System

    Science.gov (United States)

    1971-03-02

    underwater speed sensor, Model 460, shown in Figure 8, is made by Hydro Products. The unit is a precision balanced, high impact *, polystyrene Savonius ...ocean environment. Tiie operation of the unit is as follows: water movement past the underwater sensor rotates the Savonius rotor at an angular rate

  15. An open labeled, comparative clinical study on efficacy and tolerability of oral minipulse of steroid (OMP alone, OMP with PUVA and broad / narrow band UVB phototherapy in progressive vitiligo

    Directory of Open Access Journals (Sweden)

    Rath Namita

    2008-01-01

    Full Text Available Background: Several modalities of treatment have been tried in vitiligo with varied results; however, Indian data on comparative studies of two or more therapies are limited. Aims: We compared different phototherapy methods with an oral steroid as an adjunct to determine the method with the best tolerability and efficacy. Methods: Eighty-six patients with progressive vitiligo were randomly assigned to different study groups according to a continuous selection method over a period of one year. Group 1 was given OMP + PUVA, group 2 OMP + UVB (NB, group 3 OMP + UVB (BB and group 4 was given OMP alone. Each patient was followed up for six months and then released from treatment. Clinical evaluation was made at the end of three and six months. Results: In group 1 (OMP + PUVA, marked improvement was seen in 18.51% while moderate improvement was seen in 66.66% of the patients. Marked improvement was seen in 37.03% in group 2 (OMP + NB-UVB while 44.44% had moderate improvement. In group 3 (OMP + BB UVB, 8.33% showed marked improvement while moderate improvement was seen in 25% of the patients. Marked and moderate improvement was seen in 5 and 10% of group 4 (OMP patients, respectively. Conclusions: Our study compared four treatment modalities in vitiligo patients, out of which oral minipulse of steroids (OMP only had an adjunct value and was not very effective by itself. Narrow band UVB has a definite edge over broad band UVB and should be preferred when both options are available. NB-UVB and PUVA showed comparable efficacy.

  16. Broad-band spectroscopy of the transient X-ray binary pulsar KS 1947+300 during 2013 giant outburst: Detection of pulsating soft X-ray excess component

    CERN Document Server

    Epili, Prahlad; Jaisawal, Gaurava K

    2016-01-01

    We present the results obtained from detailed timing and spectral studies of the Be/X-ray binary pulsar KS 1947+300 during its 2013 giant outburst. We used data from Suzaku observations of the pulsar at two epochs i.e. on 2013 October 22 (close to the peak of the outburst) and 2013 November 22. X-ray pulsations at $\\sim$18.81 s were clearly detected in the light curves obtained from both observations. Pulse periods estimated during the outburst showed that the pulsar was spinning up. The pulse profile was found to be single-peaked up to $\\sim$10 keV beyond which a sharp peak followed by a dip-like feature appeared at hard X-rays. The dip-like feature has been observed up to $\\sim$70 keV. The 1-110 keV broad-band spectroscopy of both observations revealed that the best-fit model comprised of a partially absorbed Negative and Positive power law with EXponential cutoff (NPEX) continuum model along with a blackbody component for the soft X-ray excess and two Gaussian functions at 6.4 and 6.7 keV for emission line...

  17. Tectonic and Kinematic Regime along the Northern Caribbean Plate Boundary: New Insights from Broad-band Modeling of the May 25, 1992, Ms = 6.9 Cabo Cruz, Cuba, Earthquake

    Science.gov (United States)

    Perrot, J.; Calais, E.; Mercier de Lépinay, B.

    On May 25th, 1992, an Ms = 6.9 earthquake occurred off the southwestern tip of Cuba, along the boundary between the Caribbean and North American plates. This earthquake was the largest to strike southern Cuba since 1917 and the largest ever recorded in that region by global seismic networks. It is therefore a key element for our understanding of the tectonic and kinematic regime along the northern Caribbean plate boundary. In order to test the previously proposed source parameters of the Cabo Cruz earthquake and to better constrain its focal mechanism, we derived a new set of source parameters from unfiltered broad-band teleseismic records. We used a hybrid ray tracing method that allows us to take into account propagation effects of seismic waves in a realistic crustal model around the source. Our solution is consistent with the long-period focal mechanism solution of Virieux et al. (1992). Our solution also models the higher frequency crustal and water layer phases. The primarily strike-slip focal mechanism has a small thrust component. Its shows an east-west trending nodal plane dipping 55° to the north that we interpret as the rupture plane since it corresponds to the geometry of the major active fault in that area. The displacement on this plane is a left-lateral strike-slip combined with a small amount of southward thrust. The result is in good agreement with the active tectonic structures observed along the Oriente fault south of Cuba. The small thrust component demonstrates that, contrary to prior belief, the transpressive regime extends along this whole segment of the Caribbean/North American plate boundary. Together with historical seismicity, it suggests that most of the stress accumulated by the Caribbean/North American plate motion is released seismically along the southern Cuban margin during relatively few but large earthquakes.

  18. Runs 800, 813, 842 and physics runs from 18.1.77 to 21.5.77, Development of a new set-up for working line measurements including a Fast Fourier Transform Spectrum Analyser and using weak beam excitiation with broad-band noise

    CERN Document Server

    Borer, J

    1977-01-01

    Runs 800, 813, 842 and physics runs from 18.1.77 to 21.5.77, Development of a new set-up for working line measurements including a Fast Fourier Transform Spectrum Analyser and using weak beam excitiation with broad-band noise

  19. The 2010 Broad Prize

    Science.gov (United States)

    Education Digest: Essential Readings Condensed for Quick Review, 2011

    2011-01-01

    A new data analysis, based on data collected as part of The Broad Prize process, provides insights into which large urban school districts in the United States are doing the best job of educating traditionally disadvantaged groups: African-American, Hispanics, and low-income students. Since 2002, The Eli and Edythe Broad Foundation has awarded The…

  20. The Broad Foundations, 2006

    Science.gov (United States)

    Broad Foundation, 2006

    2006-01-01

    The mission of the Broad Foundations is to transform K-12 urban public education through better governance, management, labor relations and competition; make significant contributions to advance major scientific and medical research; foster public appreciation of contemporary art by increasing access for audiences worldwide; and lead and…

  1. High Reflectivity, Broad-Band Silver Coating Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future space telescopes such as the Super Nova Acceleration Probe (SNAP) require exceptionally reflective coatings applied to mirrors several meters in diameter. In...

  2. Computer-aided design of broad band reflection type amplifiers

    DEFF Research Database (Denmark)

    Hammershaimb, Edgar; Jeppesen, Palle; Schjær-Jacobsen, Hans

    1974-01-01

    . At the same time the impedance of unpackaged devices are obtained by on-line correction for the package parasitics. The microwave circuit chosen is a multiple slug coaxial cavity, that is modelled by sections of lossy transmission lines including step susceptances. The measured small signal impedance...... of the packaged TED's and the cavity model are used in a direct optimization procedure, in which the calculated minimum gain in the prescribed frequency range is progressively maximized by adjusting the lengths, characteristic impedances and positions of the slugs. The computed results are displayed...... on a datascreen, which allows for interactive programming. Comparisons of predicted amplifier performance for packaged and unpackaged devices form a basis for evaluating the possible degrading effect of package parasitics. The predictions of the computer-aided design are in good agreement with experimental...

  3. A broad-band microseismometer for planetary operations

    Science.gov (United States)

    Banerdt, W. B.; Vanzandt, T.; Kaiser, W. J.; Kenny, T. W.

    1993-06-01

    There has recently been renewed interest in the development of instrumentation for making measurements on the surface of Mars. This is due to the Mars Environmental Survey (MESUR) Mission, for which approximately 16 small, long-lived (2-10 years), relatively inexpensive surface stations will be deployed in a planet-wide network. This will allow the investigation of processes (such as seismology and meteorology) which require the simultaneous measurement of phenomena at many widely spaced locations on the surface over a considerable length of time. Due to the large number of vehicles involved, the mass, power, and cost of the payload will be severely constrained. A seismometer has been identified as one of the highest priority instruments in the MESUR straw-man payload. The requirements for an effective seismic experiment on Mars place a number of constraints on any viable sensor design. First, a large number of sensors must be deployed in a long-lived global network in order to be able to locate many events reliably, provide good spatial sampling of the interior, and increase the probability of seismic detection in the event of localized seismicity and/or high attenuation. From a practical standpoint, this means that individual surface stations will necessarily be constrained in terms of cost, mass, and power. Landing and thermal control systems will probably be simple, in order to minimize cost, resulting in large impact accelerations and wide daily and seasonal thermal swings. The level of seismic noise will determine the maximum usable sensitivity for seismometer. Unfortunately, the ambient seismic noise level for Mars is not well known. However lunar seismic noise levels are several orders of magnitude below that of the Earth. Sensitivities on the order of 10(exp -11)g over a bandwidth of .04 to 20 Hz are thought to be necessary to fulfill the science objectives for a seimometer placed on the Martian surface. Silicon micromachined sensor technology offers techniques for the fabrication of monolithic, robust, compact, lower power and mass accelerometers. Conventional micro-machined accelerometers have been developed and are commercially available for high frequency and large acceleration measurements. The new seismometer we are developing incorporates certain principles of conventional silicon micromachined accelerometer technology. However, currently available silicon micromachined sensors offer inadequate sensitivity and bandwidth for the Mars seismometer application. Our implementation of an advanced silicon micromachined seismometer is based on principles recently developed at JPL for high-sensitivity position sensor technology.

  4. Broad-Band EUV Multilayer Coatings For Solar Physics Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose to develop and commercialize a new class of aperiodic multilayer coating that is designed to provide high normal-incidence reflectance over a wide...

  5. High Reflectivity, Broad-Band Silver Coating Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Silver coatings for optics greater than 2-meters in diameter are sought by NASA for future space telescope systems. In the Phase I research, Surface Optics...

  6. Broad Band Properties of the BAT Selected AGN

    Science.gov (United States)

    Mushotzky, Richard; Winter, Lisa; Tueller, Jack

    2008-01-01

    I will present the x-ray spectral properties of approx.150 BAT selected ACN focusing on the issues of spectral complexity, x-ray absorption and its distribution and that contribution of sources to the x-ray background. If time permits we will also present the nature of the host galaxies of the ACN and their relationship to merger candidates.

  7. Ultra-broad band supercontinuum produced by terawatt femtosecond laser

    Institute of Scientific and Technical Information of China (English)

    张伟力; 王清月; 邢岐荣; 柴路; K.M.Yoo

    1997-01-01

    The characteristics of supercontinuum produced by high-intensity femtosecond pulses were investigated under different interaction lengths, various pump intensities, different pump wavelengths at the fundamental 800 nm and its second-harmonic 400 nm. High transfer-efficiency supercontinuum with flat-top in liquid media was produced. As the main nonlinear mechanisms, the effects of self-phase modulation (SPM) and four-photon parametric emission were also investigated.

  8. A multi-spectral band stellar photo-polarimeter

    CERN Document Server

    Srinivasulu, G; Muneer, S; Mekkaden, M V; Jayavel, N; Somashekar, M R; Sagayanathan, K; Ramamoorthy, S; Rosario, M J; Jayakumar, K

    2015-01-01

    We designed and built a new astronomical photo-polarimeter that can measure linear polarization simultaneously in three spectral bands. It has a Calcite beamdisplacement prism as the analyzer. The ordinary and extra-ordinary emerging beams in each spectral bands are quasi-simultaneously detected by the same photomultiplier by using a high speed rotating chopper. A rotating superachromatic Pancharatnam halfwave plate is used to modulate the light incident on the analyzer. The spectral bands are isolated using appropriate dichroic and glass filters. We show that the reduction of 50% in the efficiency of the polarimeter because of the fact that the intensities of the two beams are measured alternately is partly compensated by the reduced time to be spent on the observation of the sky background. The use of a beam-displacement prism as the analyzer completely removes the polarization of background skylight, which is a major source of error during moonlit nights, especially, in the case of faint stars. The field t...

  9. The clinical observation of 1100~1800 nm broad band infrared intense pulsed light for the treatment of periorbital wrinkle%1100~1800 nm宽波红外强光治疗眶周皱纹的临床观察

    Institute of Scientific and Technical Information of China (English)

    董依云; 周国瑜

    2014-01-01

    Objective To investigated the broad band infrared intense pulsed light (IPL) instrument for periorbital wrinkle. Methods 1100~1800 nm broad band infrared IPL (Titan, Cutera, Brisbane, CA) was used for periorbital wrinkle therapy of 31 chinese with modiifed Fitzpatrick wrinkle score (MFWS) 0.5-2.5. Energy range was 26~34 J/cm², the interval was 4 weeks, 3 to 5 times as a course. Two treatment-independent evaluators conifrmed efifcacy at baseline, the last treatment, 1 and 3 months’ follow up. The patients were asked to rate the pain level during the treatment and their satisfactory by questionnaires at 3 months’ follow up. Results An average of 0.85 class and 0.75 class was achieved at 1 and 3 months follow up respectively, which had statistical difference (P<0.05). No dissatisfactory and no adverse effect was observed. 93.54%(29/31) patients rated painless during the session. Conclusion The broad band infrared IPL technology is safe and effective for periorbital wrinkle, painless is a main advantage.%目的:验证宽波红外强光治疗眶周皱纹的有效性和安全性。方法31例治疗前改良的Fitzpatrick皱纹分型(MFWS)眶周皱纹处于0.5~2.5级的患者被纳入研究。采用1100~1800 nm宽波红外强脉冲光进行治疗,能量26~34 J/cm2,4周1次,3~5次为1个疗程。由两位独立的第三方专家同时对患者眶周皱纹治疗前、疗程结束后、疗程结束后1个月和3个月的疗效进行分析。通过问卷形式由患者对术中疼痛度和术后3个月疗效满意度进行评分。结果治疗后1个月、3个月随访中患者Fitzpatrick 皱纹分型平均值分别由治疗前的1.5级下降到0.85级和0.75级,差异有统计学意义(P<0.05)。93.54%(29/31)的患者认为治疗过程中无疼痛,无明显不良反应。结论宽波红外强脉冲光技术治疗眶周皱纹安全有效,疼痛感少是其优点。

  10. 多波段相关光子光谱分布与时间相关性测量实验研究%Research on the Distribution of Broad-Band Correlated Photon Spectra and the Measurement of Time-Correlation

    Institute of Scientific and Technical Information of China (English)

    高冬阳; 李健军; 夏茂鹏; 郑小兵

    2016-01-01

    基于相关光子的定标技术能够实现“无标准传递”绝对定标,研究相关光子的光谱辐射特性及时间相关特性对遥感器在宽波段的辐射定标具有重要意义。为满足光电探测器在宽谱段量子效率定标需求,基于相关光子的定标技术有必要从单一波段向更多波段扩展。根据自发参量下转换所满足的相位匹配条件,推导出相关光子在晶体内的非共线角计算公式,通过数值模拟相关光子光谱辐射角度分布规律,优化晶体相位匹配角,使得自发参量下转换产生的相关光子具有宽光谱分布,并且相关光子辐射角度与光谱波长能够一一对应。根据光谱分布数值模拟结果,建立了多波段相关光子的光谱分布和时间相关性测量实验系统,利用该系统测量了四对相关光子的光谱分布、符合计数、相关时间以及偏振特性。其中,测量的光谱分布范围为633~808 nm,最大光谱分布测量偏差为1.51 mm,光谱分布实验测量结果与数值模拟结果符合一致;测量了四对相关光子对的相关时间,最小相关时间为0.32 ns,并在实验中观察到了“符合三峰”现象;相关光子单光子计数及符合计数与泵浦光的偏振方向呈正弦函数关系。实验研究表明,相关光子对具有可见光~近红外宽波段分布、时间相关及偏振特性。论文研究结果在国内外尚属首次报道,该研究结果有望应用于光电探测器在多波段的辐射定标。%The correlated photon technique makes it possible to achieve a radiation calibration processing without chain transfer-ring.The study of the spectral radiation character and time correlation of the photon is of great significance for broad-band radio-metric calibration.To absolutely calibrate quantum efficiency of photoelectric detector,it is necessary to extend calibration band from single band to more bands.According to the phase-matching condition of the spontaneous

  11. Oil spill analysis by means of full polarimetric UAVSAR (L-band) and Radarsat-2 (C-band) products acquired during Deepwater Horizon Disaster

    Science.gov (United States)

    Latini, Daniele; Del Frate, Fabio; Jones, Cathleen E.

    2014-10-01

    SAR instruments with polarimetric capabilities, high resolution and short revisit time can provide powerful support in oil spill monitoring and different techniques of analysis have been developed for this purpose [1][2]. An oil film on the sea surface results in darker areas in SAR images, but careful interpretation is required because dark spots can also be caused by natural phenomena. In view of the very low backscatter from slicks, the Noise Equivalent Sigma Zero (NESZ) is a primary sensor parameter to be considered when using a sensor for slick analysis. Among the existing full polarimetric sensors, the high resolution and very low NESZ values of UAVSAR (L-band) and RADARSAT-2 (C-band) make them preferable for oil spill analysis compared to the last generation SAR instruments. The Deepwater Horizon disaster that occurred in the Gulf of Mexico in 2010 represents a unique and extensive test site where large amounts of SAR imagery and ground validation data are available. By applying the Cloude-Pottier decomposition method to full polarimetric UAVSAR (L-band) and RADARSAT-2 (C-band), it is possible to extract parameters that describe the scattering mechanism of the target. By comparing quasi-simultaneous acquisitions and exploiting the different penetration capabilities of the sensors, we investigate the potential of full polarimetric SAR to discriminate oil on the sea surface from look-alike phenomena covering the full range of backscattering values down to those at the instrument noise floor.

  12. Colloquium: Topological band theory

    Science.gov (United States)

    Bansil, A.; Lin, Hsin; Das, Tanmoy

    2016-04-01

    The first-principles band theory paradigm has been a key player not only in the process of discovering new classes of topologically interesting materials, but also for identifying salient characteristics of topological states, enabling direct and sharpened confrontation between theory and experiment. This review begins by discussing underpinnings of the topological band theory, which involve a layer of analysis and interpretation for assessing topological properties of band structures beyond the standard band theory construct. Methods for evaluating topological invariants are delineated, including crystals without inversion symmetry and interacting systems. The extent to which theoretically predicted properties and protections of topological states have been verified experimentally is discussed, including work on topological crystalline insulators, disorder and interaction driven topological insulators (TIs), topological superconductors, Weyl semimetal phases, and topological phase transitions. Successful strategies for new materials discovery process are outlined. A comprehensive survey of currently predicted 2D and 3D topological materials is provided. This includes binary, ternary, and quaternary compounds, transition metal and f -electron materials, Weyl and 3D Dirac semimetals, complex oxides, organometallics, skutterudites, and antiperovskites. Also included is the emerging area of 2D atomically thin films beyond graphene of various elements and their alloys, functional thin films, multilayer systems, and ultrathin films of 3D TIs, all of which hold exciting promise of wide-ranging applications. This Colloquium concludes by giving a perspective on research directions where further work will broadly benefit the topological materials field.

  13. Band Together!

    Science.gov (United States)

    Olson, Cathy Applefeld

    2011-01-01

    After nearly a decade as band director at St. James High School in St. James, Missouri, Derek Limback knows that the key to building a successful program is putting the program itself above everything else. Limback strives to augment not only his students' musical prowess, but also their leadership skills. Key to his philosophy is instilling a…

  14. Multi-band optical variability of the Blazar S5 0716+714 in outburst state during 2014-2015

    CERN Document Server

    Agarwal, Aditi; Bachev, R; Strigachev, A; Semkov, E; Wiita, Paul J; Fan, J H; Pandey, U S; Boeva, S; Spassov, B

    2015-01-01

    We analyzed the multi-band optical behaviour of the BL Lacertae object, S5 0716+714, during its outburst state from 2014 November - 2015 March. We took data on 23 nights at three observatories, one in India and two in Bulgaria, making quasi-simultaneous observations in B, V, R, and I bands. We measured multi-band optical fluxes, colour and spectral variations for this blazar on intraday and short timescales. The source was in a flaring state during the period analyzed and displayed intense variability in all wavelengths. R band magnitude of 11.6 was attained by the target on 18 Jan 2015, which is the brightest value ever recorded for S5 0716+714. The discrete correlation function method yielded good correlation between the bands with no measurable time lags, implying that radiation in these bands originate from the same region and by the same mechanism. We also used the structure function technique to look for characteristic timescales in the light curves. During the times of rapid variability, no evidence fo...

  15. Broad spectral range synchronized flat-top arrayed waveguide grating

    NARCIS (Netherlands)

    Akca, B. Imran; Doerr, Christopher R.; Pollnau, Markus; Ridder, de René M.

    2012-01-01

    A broad-band Mach-Zehnder-interferometer-synchronized flat-top arrayed waveguide grating is presented with a 0.5-dB bandwidth of 12 nm over 90 nm of spectral range and a central excess loss value of -0.5 dB.

  16. Broad-spectrum antiviral agents

    Directory of Open Access Journals (Sweden)

    Jun-Da eZhu

    2015-05-01

    Full Text Available Development of highly effective, broad-spectrum antiviral agents is the major objective shared by the fields of virology and pharmaceutics. Antiviral drug development has focused on targeting viral entry and replication, as well as modulating cellular defense system. High throughput screening of molecules, genetic engineering of peptides, and functional screening of agents have identified promising candidates for development of optimal broad-spectrum antiviral agents to intervene in viral infection and control viral epidemics. This review discusses current knowledge, prospective applications, opportunities, and challenges in the development of broad-spectrum antiviral agents.

  17. Broad resonances in transport theory

    CERN Document Server

    Leupold, S

    2003-01-01

    The extension of the transport theoretical framework to include states with a broad mass distribution is discussed. The proper life-time and cross sections for a state with an arbitrarily given invariant mass is discussed in detail. (author)

  18. PG 1411 + 442 - The nearest broad absorption line quasar

    Science.gov (United States)

    Malkan, Matthew A.; Green, Richard F.; Hutchings, John B.

    1987-01-01

    IUE observations reveal strong, moderately broad absorption troughs in the blue wings of the C IV and N V emission lines of the quasar PG 1411 + 442. No absorption from weakly ionized gas is detected. The emission-line strengths and overall shape of the ultraviolet/optical/near-infrared/far-infrared continuum of the new broad absorption line quasar are within the range normally measured in quasars. Its redshift is low enough to allow the morphology of the host galaxy to be studied in deep broad-band and intermediate-band CCD images. The galaxy appears to be a large spiral with a very long arm or tail. The inclination angle is 57 deg, which rules out the possibility that the line of sight to the nucleus intersects a large path length in a galactic disk.

  19. Modeling the spectral-energy-distribution of 3C 454.3 in a "flat" broad-line-region scenario

    CERN Document Server

    Lei, Maichang

    2014-01-01

    The broad-line region (BLR) of flat-spectrum radio quasars (FSRQs) could have a "flat" geometrical structure to allow GeV gamma-ray photons escape, to produce the observed gamma-ray flares with short timescales. In this paper, we collect the quasi-simultaneous spectral energy distributions (SEDs) of the FSRQ 3C 454.3 obtained by the multi-wavelength campaigns spanning from 2007 July to 2011 January, and use a model with the "flat" structure BLR, the accretion disc and the dust torus to explain the SEDs of gamma-ray outbursts. We obtain the following results: (i) The jet is almost in equipartition between magnetic and particle energy densities during the outbursts; (ii) When the emitting region locates inside the cavity of the BLR, the covering factor $f_{\\rm BLR}$ of the BLR is very small; as the emitting region goes into the BLR structure, $f_{\\rm BLR}$ increases. (iii) The aperture angle $\\alpha$ describing the BLR structure is about $45^{\\circ}$; (iv) The central black hole (BH) mass is about $5\\times 10^{...

  20. A beam-displacement prism based, three band stellar photo-polarimeter

    CERN Document Server

    Raveendran, A V; Muneer, S; Mekkaden, M V; Jayavel, N; Somashekar, M R; Sagayanathan, K; Ramamoorthy, S; Rosario, M J; Jayakumar, K

    2015-01-01

    A new astronomical photo-polarimeter that can measure linear polarization of point sources simultaneously in three spectral bands was designed and built in Indian Institute of Astrophysics. The polarimeter has a Calcite beam-displacement prism as the analyzer. The ordinary and extra-ordinary emerging beams in each spectral band are quasi-simultaneously detected by the same photomultiplier by using a high speed rotating chopper. The effective chopping frequency can be set to as high as 200 Hz. A rotating superachromatic Pancharatnam halfwave plate is used to modulate the light incident on the analyzer. The spectral bands are isolated using appropriate dichroic and glass filters. A detailed analysis shows that the reduction of 50% in the efficiency of the polarimeter because of the fact that the intensities of the two beams are measured alternately is partly compensated by the reduced time to be spent on the observation of the sky background. The position angle of polarization produced by the Glan-Taylor prism ...

  1. The Broad Autism Phenotype Questionnaire

    Science.gov (United States)

    Hurley, Robert S. E.; Losh, Molly; Parlier, Morgan; Reznick, J. Steven; Piven, Joseph

    2007-01-01

    The broad autism phenotype (BAP) is a set of personality and language characteristics that reflect the phenotypic expression of the genetic liability to autism, in non-autistic relatives of autistic individuals. These characteristics are milder but qualitatively similar to the defining features of autism. A new instrument designed to measure the…

  2. Broad Diphotons from Narrow States

    CERN Document Server

    An, Haipeng; Zhang, Yue

    2015-01-01

    ATLAS and CMS have each reported a modest diphoton excess consistent with the decay of a broad resonance at ~ 750 GeV. We show how this signal can arise in a weakly coupled theory comprised solely of narrow width particles. In particular, if the decaying particle is produced off-shell, then the associated diphoton resonance will have a broad, adjustable width. We present simplified models which explain the diphoton excess through the three-body decay of a scalar or fermion. Our minimal ultraviolet completion is a weakly coupled and renormalizable theory of a singlet scalar plus a heavy vector-like quark and lepton. The smoking gun of this mechanism is an asymmetric diphoton peak recoiling against missing transverse energy, jets, or leptons.

  3. Broad-spectrum antiviral therapeutics.

    Directory of Open Access Journals (Sweden)

    Todd H Rider

    Full Text Available Currently there are relatively few antiviral therapeutics, and most which do exist are highly pathogen-specific or have other disadvantages. We have developed a new broad-spectrum antiviral approach, dubbed Double-stranded RNA (dsRNA Activated Caspase Oligomerizer (DRACO that selectively induces apoptosis in cells containing viral dsRNA, rapidly killing infected cells without harming uninfected cells. We have created DRACOs and shown that they are nontoxic in 11 mammalian cell types and effective against 15 different viruses, including dengue flavivirus, Amapari and Tacaribe arenaviruses, Guama bunyavirus, and H1N1 influenza. We have also demonstrated that DRACOs can rescue mice challenged with H1N1 influenza. DRACOs have the potential to be effective therapeutics or prophylactics for numerous clinical and priority viruses, due to the broad-spectrum sensitivity of the dsRNA detection domain, the potent activity of the apoptosis induction domain, and the novel direct linkage between the two which viruses have never encountered.

  4. Ghost imaging with broad distance

    Institute of Scientific and Technical Information of China (English)

    段德洋; 张路; 杜少将; 夏云杰

    2015-01-01

    We present a scheme that is able to achieve the ghost imaging with broad distance. The physical nature of our scheme is that the different wavelength beams are separated in free space by an optical media according to the slow light or dispersion principle. Meanwhile, the equality of the optical distance of the two light arms is not violated. The photon correlation is achieved by the rotating ground glass plate (RGGP) and spatial light modulator (SLM), respectively. Our work shows that a monochromic ghost image can be obtained in the case of RGGP. More importantly, the position (or distance) of the object can be ascertained by the color of the image. Thus, the imaging and ranging processes are combined as one process for the first time to the best of our knowledge. In the case of SLM, we can obtain a colored image regardless of where the object is.

  5. HYBASE : HYperspectral BAnd SElection

    NARCIS (Netherlands)

    Schwering, P.B.W.; Bekman, H.H.P.T.; Seijen, H.H. van

    2009-01-01

    Band selection is essential in the design of multispectral sensor systems. This paper describes the TNO hyperspectral band selection tool HYBASE. It calculates the optimum band positions given the number of bands and the width of the spectral bands. HYBASE is used to assess the minimum number of spe

  6. Broad Leaves in Strong Flow

    CERN Document Server

    Miller, Laura

    2013-01-01

    Flexible broad leaves are thought to reconfigure in the wind and water to reduce the drag forces that act upon them. Simple mathematical models of a flexible beam immersed in a two-dimensional flow will also exhibit this behavior. What is less understood is how the mechanical properties of a leaf in a three-dimensional flow will passively allow roll up into a cone shape and reduce both drag and vortex induced oscillations. In this fluid dynamics video, the flows around the leaves are compared with those of simplified sheets using 3D numerical simulations and physical models. For some reconfiguration shapes, large forces and oscillations due to strong vortex shedding are produced. In the actual leaf, a stable recirculation zone is formed within the wake of the reconfigured cone. In physical and numerical models that reconfigure into cones, a similar recirculation zone is observed with both rigid and flexible tethers. These results suggest that the three-dimensional cone structure in addition to flexibility is ...

  7. Broad-Spectrum Solution-Processed Photovoltaics

    Science.gov (United States)

    Ip, Alexander Halley

    High global demand for energy coupled with dwindling fossil fuel supply has driven the development of sustainable energy sources such as solar photovoltaics. Emerging solar technologies aim for low-cost, solution-processable materials which would allow wide deployment. Colloidal quantum dots (CQDs) are such a materials system which exhibits the ability to absorb across the entire solar spectrum, including in the infrared where many technologies cannot harvest photons. However, due to their nanocrystalline nature, CQDs are susceptible to surface-associated electronic traps which greatly inhibit performance. In this thesis, surface engineering of CQDs is presented through a combined ligand approach which improves the passivation of surface trap states. A metal halide treatment is found to passivate quantum dot surfaces in solution, while bifunctional organic ligands produce a dense film in solid state. This approach reduced midgap trap states fivefold compared with conventional passivation strategies and led to solar cells with a record certified 7.0% power conversion efficiency. The effect of this process on the electronic structure is studied through photoelectron spectroscopy. It is found that while the halide provides deep trap passivation, the nature of the metal cation on the CQD surface affects the density of band tail states. This effect is explored further through a wide survey of materials, and it is found that the coordination ability of the metal cation is responsible for the suppression of shallow traps. With this understanding of CQD surface passivation, broad spectral usage is then explored through a study of visible-absorbing organolead halide perovskite materials as well as narrow-bandgap CQD solar cells. Control over growth conditions and modification of electrode interfaces resulted in efficient perovskite devices with effective usages of visible photons. For infrared-absorbing CQDs, it is found that, in addition to providing surface trap

  8. 76 FR 34087 - Broad Stakeholder Survey

    Science.gov (United States)

    2011-06-10

    ... SECURITY Broad Stakeholder Survey AGENCY: National Protection and Programs Directorate, DHS. ACTION: 60-day... comments concerning the Broad Stakeholder Survey. DATES: Comments are encouraged and will be accepted until.... The Broad Stakeholder Survey is designed to gather stakeholder feedback on the effectiveness of...

  9. 78 FR 20119 - Broad Stakeholder Survey

    Science.gov (United States)

    2013-04-03

    ... SECURITY Broad Stakeholder Survey AGENCY: National Protection and Programs Directorate, DHS. ACTION: 30-day... soliciting comments concerning the Broad Stakeholder Survey. DHS previously published this ICR in the Federal... responders across the Nation. The Broad Stakeholder Survey is designed to gather stakeholder feedback on...

  10. 77 FR 50144 - Broad Stakeholder Survey

    Science.gov (United States)

    2012-08-20

    ... SECURITY Broad Stakeholder Survey AGENCY: National Protection and Programs Directorate, DHS. ACTION: 60-day... comments concerning the Broad Stakeholder Survey. DATES: Comments are encouraged and will be accepted until... across the Nation. The Broad Stakeholder Survey is designed to gather stakeholder feedback on...

  11. Enhanced transmittance of a dual pass-band metamaterial filter

    Science.gov (United States)

    Wang, XiaoZhi; Zhu, Honghui; Liu, Zhigang

    2017-03-01

    A broad pass-band metamaterial-based optical filter is experimentally and numerically studied. The designed structure consists of periodically arranged composite metallic arrays and dielectric layer that exhibits transmission responses composed of two flat pass-bands. The coupling of localized surface plasmon (LSP) modes results in the low-frequency pass-band, while the internal surface plasmon polaritons (ISPPs) between the upper and lower metal layers leads to the high-frequency pass-band. Structural parameters (L and R) are experimentally considered from the viewpoint of exploiting their effects on the pass-bands and resonance frequencies. The bandwidths of these pass-bands both can reach to maximums by optimization of these structural parameters. In addition, the two pass-bands can be modulated to be a single pass-band with a bandwidth of 10.7 THz by optimizing L and R simultaneously.

  12. Biconical Ring Antenna Array for Wide Band Applications

    Directory of Open Access Journals (Sweden)

    C.SUBBA RAO

    2012-02-01

    Full Text Available Circular or ring arrays are conformal to the cylindrical surfaces unlike the linear arrays and can be mounted on moving objects. Biconical antenna is simple in construction and exhibits broad band characteristics. This antenna presents broad band radiation characteristics. In this paper circular or ring array of biconical antenna is proposed and its characteristics are analyzed for frequency band of 0.1 to 1GHz range. Radiation characteristicsof the array with excitation phase change are presented. Simulated results of the radiation characteristics of the circular array are analyzed.

  13. 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

  14. 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...

  15. Low Power Band to Band Tunnel Transistors

    Science.gov (United States)

    2010-12-15

    the E-field and tunneling at the source- pocket junction you form a parasitic NPN + transistor and the injection mechanism of carriers into the...hypothesis that the 1000 ° C, 5s anneal split lead to a very wide pocket and the accidental formation of a NPN + transistor , while the 1000 ° C, 1s anneal...Low Power Band to Band Tunnel Transistors Anupama Bowonder Electrical Engineering and Computer Sciences University of California at Berkeley

  16. Broad Prize: Do the Successes Spread?

    Science.gov (United States)

    Samuels, Christina A.

    2011-01-01

    When the Broad Prize for Urban Education was created in 2002, billionaire philanthropist Eli Broad said he hoped the awards, in addition to rewarding high-performing school districts, would foster healthy competition; boost the prestige of urban education, long viewed as dysfunctional; and showcase best practices. Over the 10 years the prize has…

  17. Influenza virus antigenicity and broadly neutralizing epitopes.

    Science.gov (United States)

    Air, Gillian M

    2015-04-01

    A vaccine formulation that would be effective against all strains of influenza virus has long been a goal of vaccine developers, but antibodies after infection or vaccination were seen to be strain specific and there was little evidence of cross-reactive antibodies that neutralized across subtypes. Recently a number of broadly neutralizing monoclonal antibodies have been characterized. This review describes the different classes of broadly neutralizing antibodies and discusses the potential of their therapeutic use or for design of immunogens that induce a high proportion of broadly neutralizing antibodies.

  18. Gutzwiller theory of band magnetism in LaOFeAs

    Energy Technology Data Exchange (ETDEWEB)

    Schickling, Tobias; Gebhard, Florian [Fachbereich Physik, Philipps Universitaet, D-35037 Marburg (Germany); Buenemann, Joerg [Institut fuer Physik, BTU Cottbus, D-03013 Cottbus (Germany); Boeri, Lilia; Andersen, Ole K. [Max Planck Institute for Solid State Research, D-70569 Stuttgart (Germany); Weber, Werner [Fakultaet Physik, TU Dortmund, D-44221 Dortmund (Germany)

    2012-07-01

    For the iron pnictide LaOFeAs we investigate multi-band Hubbard models which are assumed to capture the relevant physics. In our calculations, we employ the Gutzwiller variational theory which is a genuine many particle approach. We will present results both on the paramagnetic and antiferromagnetic phases of our model systems. These results show that a five band-model is not adequate to capture the relevant physics in LaOFeAs. However, our results for the eight band-model which includes the arsenic 4p bands reproduce the experimental data, especially the small magnetic moment, for a broad parameter regime.

  19. Measuring Prevention More Broadly, An Empirical...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Measuring Prevention More Broadly, An Empirical Assessment of CHIPRA Core Measures Differences in CHIP design and structure, across states and over time, may limit...

  20. Design of Dual-Band Two-Branch-Line Couplers with Arbitrary Coupling Coefficients in Bands

    Directory of Open Access Journals (Sweden)

    I. Prudyus

    2014-12-01

    Full Text Available A new approach to design dual-band two-branch couplers with arbitrary coupling coefficients at two operating frequency bands is proposed in this article. The method is based on the usage of equivalent subcircuits input reactances of the even-mode and odd-mode excitations. The exact design formulas for three options of the dual-band coupler with different location and number of stubs are received. These formulas permit to obtain the different variants for each structure in order to select the physically realizable solution and can be used in broad range of frequency ratio and power division ratio. For verification, three different dual-band couplers, which are operating at 2.4/3.9 GHz with different coupling coefficients (one with 3/6 dB, and 10/3 dB two others are designed, simulated, fabricated and tested. The measured results are in good agreement with the simulated ones.

  1. Broad-Band Imaging of a Large Sample of Irregular Galaxies

    CERN Document Server

    Hunter, D A; Hunter, Deidre A.; Elmegreen, Bruce G.

    2005-01-01

    We present the results of UBV imaging of a large sample of irregular galaxies: 94 Im systems, 24 Blue Compact Dwarfs (BCDs), and 18 Sm galaxies. We also include JHK imaging of 41 of these galaxies. The sample spans a large range in galactic parameters. Ellipse fit axial ratios, inclinations, and position angles are derived, integrated photometry and azimuthally-averaged surface photometry profiles are determined, and exponential fits give the central surface brightnesses, scale lengths, and isophotal and half-power radii. These data are used to address the shapes of Im galaxies, look for clues to past interactions in large-scale peculiarities, examine the nature and consequences of bars, study color gradients and large-scale color variations, and compare the exponential disk profiles of the young and old stellar components. For example, color gradients exhibit a great variety and not all passbands are correlated. Bars are associated with higher star formation rates. Many irregulars show a double exponential r...

  2. Coaxial Sensors For Broad-Band Complex Permittivity Measurements of Petroleum Fluids

    Energy Technology Data Exchange (ETDEWEB)

    Folgeroe, K.

    1996-12-31

    This doctoral thesis verifies that dielectric spectroscopy and microwave permittivity measurements can be used to characterize petroleum liquids. It concentrates on developing sensors for three potential industrial applications: quality characterization of crude oil and petroleum fractions, monitoring of gas-hydrate formation in water-in-oil emulsions, and determination of water-content in thin liquid layers. The development of a permittivity measurement system for crude oil and petroleum fractions is described. As black oils have low dielectric constant and loss, the system must be very sensitive in order to measure the dielectric spectra and to distinguish oils of different permittivity. Such a system was achieved by combining impedance and scattering parameter measurements with appropriate permittivity calculation methods. The frequency range from 10 kHz to 6 GHz was found convenient for observing the main dispersion of the oils. All the oils had dielectric constants between 2.1 and 2.9 and dielectric loss below 0.01. The oils studied were samples of the feedstock for the cracker and coke processes at a petroleum refinery. This verifies that dielectric spectroscopy is a potential technique for on-line quality monitoring of the feedstock at petroleum refineries. Gas hydrates may cause major problems like clogging of pipelines. Dielectric spectroscopy is proposed as a means of monitoring the formation of gas hydrates in emulsions. It is found that open-ended coaxial probes fulfill the sensitivity requirements for such sensors. 312 refs., 87 figs., 20 tabs.

  3. Ultrafast carrier dynamics in band edge and broad deep defect emission ZnSe nanowires

    Science.gov (United States)

    Othonos, Andreas; Lioudakis, Emmanouil; Philipose, U.; Ruda, Harry E.

    2007-12-01

    Ultrafast carrier dynamics of ZnSe nanowires grown under different growth conditions have been studied. Transient absorption measurements reveal the dependence of the competing effects of state filling and photoinduced absorption on the probed energy states. The relaxation of the photogenerated carriers occupying defect states in the stoichiometric and Se-rich samples are single exponentials with time constants of 3-4ps. State filling is the main contribution for probe energies below 1.85eV in the Zn-rich grown sample. This ultrafast carrier dynamics study provides an important insight into the role that intrinsic point defects play in the observed photoluminescence from ZnSe nanowires.

  4. Broad band Transmission Performance over Residential Power Lines Employing VDSL2

    Directory of Open Access Journals (Sweden)

    Usha Rani K R

    2013-01-01

    Full Text Available Bridging and Transmission of VDSL2 broadband over power lines has received considerable attention recently to cater to broadband distribution within the premises of a residence. Power lines are fundamentally different from telephone lines both in topology and load impedance. Power lines have a thicker gauge and shorter straight lengths, apart from a large number of bridge taps (BT with inductive load terminations, which are not matched to line impedances. In this paper ABCD parameters of the individual sections are used to analyze the power line channel of upto 10 bridge taps over a 600 meter length. The noise profiles considered include periodic impulse noise which is predominant over power line sections, apart from AWGN. Tone loading profiles have been obtained using Discrete Multitone Transmission (DMT as in VDSL2 over a bandwidth of 30 MHz. This analysis points to the fact that lower Transmit PSD would suffice to match the rates achievable by traditional VDSL2 when bridge taps are open. However with inductive loads typical in residences, we recommend a two step approach of (a equipping existing VDSL2 modem front end hybrids with settable impedances that would approach a conjugate match of the loaded line along with (b capability to nominally increase the Transmit PSD and added subbands to achieve the desired rates in a seamless manner as in VDSL2.

  5. Development of a large reactive silencer to attenuate mid frequency broad band sound: a case study

    Energy Technology Data Exchange (ETDEWEB)

    Sacks, M. P.; Kane, J.

    1996-08-01

    Development of a large reactive silencer, modifying the pollution control system of a fluid catalytic cracking unit at an east coast oil refinery, was described. The modification was necessitated by complaints from nearby residents, and company determination that sound levels in the community could reach 75dBA to 80 dBA under frequent downwind conditions in an otherwise quiet residential area. Design, construction and testing of a scale model, static testing of the full size silencer prior to delivery and installation, and preliminary in situ results were reviewed and discussed. 1 ref., 5 figs.

  6. Happy Birthday Swift: Ultra-long GRB141121A and its broad-band Afterglow

    CERN Document Server

    Cucchiara, A; Corsi, A; Cenko, S B; Perley, D A; Marshall, A Lien F E; Pagani, C; Toy, V L; Capone, J I; Frail, D A; Horesh, A; Modjaz, M; Butler, N R; Littlejohns, O M; Watson, A M; Kutyrev, A S; Lee, W H; Richer, M G; Klein, C R; Fox, O D; Prochaska, J X; Bloom, J S; Troja, E; Ramirez-Ruiz, E; de Diego, J A; Georgiev, L; Gonzalez, J; Roman-Zuniga, C G; Gehrels, N; Moseley, H

    2015-01-01

    We present our extensive observational campaign on the Swift-discovered GRB141121A, al- most ten years after its launch. Our observations covers radio through X-rays, and extends for more than 30 days after discovery. The prompt phase of GRB 141121A lasted 1410 s and, at the derived redshift of z = 1.469, the isotropic energy is E{\\gamma},iso = 8.0x10^52 erg. Due to the long prompt duration, GRB141121A falls into the recently discovered class of UL-GRBs. Peculiar features of this burst are a flat early-time optical light curve and a radio-to-X-ray rebrightening around 3 days after the burst. The latter is followed by a steep optical-to-X-ray decay and a much shallower radio fading. We analyze GRB 141121A in the context of the standard forward-reverse shock (FS,RS) scenario and we disentangle the FS and RS contributions. Finally, we comment on the puzzling early-time (t ~3 d) behavior of GRB 141121A, and suggest that its interpretation may require a two-component jet model. Overall, our analysis confirms that ...

  7. Advanced Multi-Photon Chromophores for Broad-Band Ultra-Fast Optical Limiting

    Science.gov (United States)

    2014-11-04

    benzothiazole (BT) and NO2, represent a range of electron-donating (ED) and electron-withdrawing (EW) strengths, while the Pt-core acts as a weak ED...different substituents, R = N(phenyl)2 (NPh2), NH2, OCH3, t-butyl, CH3, H, F, CF3, CN, benzothiazole (BT) and NO2, represent a range of electron...variation in electron donating (ED) and electron withdrawing (EW) strengths R = NPh2, NH2, OCH3, t-Butyl, CH3, H, F, CF3, CN, Benzothiazole (BT) and

  8. Teleseismic SKS splitting beneath East Antarctica using broad-band stations around Soya Coast

    Science.gov (United States)

    Usui, Y.; Kanao, M.

    2006-12-01

    We observed shear wave splitting of SKS waves from digital seismographs that are recorded at 5 stations around Soya Coast in the Lutzow-Holm Bay, East Antarctica. Their recording systems are composed of a three-component broadband seismometer (CMG-40T), a digital recording unit and a solar power battery supply. The events used were selected from 1999 to 2004 and phase arrival times were calculated using the IASPEI91 earth model (Kennet, 1995). In general, we chose the data from earthquakes with m>6.0 and a distance range 85° < Δ < 130° for the most prominent SKS waves We used the methods of Silver and Chan (1991) for the inversion of anisotropy parameters and estimated the splitting parameters φ (fast polarization direction) and δt (delay time between split waves) assuming a single layer of hexagonal symmetry with a horizontal symmetry axis. The weighted averages of all splitting parameters (φ, δt) for each station are AKR (30±4, 1.30±0.2), LNG (58±6, 1.27±0.2), SKL (67±10, 0.94±0.2), SKV (40±6, 1.28±0.3) and TOT (52±8, 1.26±0.3), where the weights are inversely proportional to the standard deviations for each solution. As compared to typical delay times of SKS waves which show 1.2s (Silver and Chan 1991; Vinnik et al., 1992), the result shows generally the same value. In previous study, Kubo and Hiramatsu (1998) estimate the splitting parameter for Syowa station (SYO), where is located near our using stations in East Antarctica, and the results are (49±3, 0.70±0.1). Although it is consistent with our results for fast polarization direction, δt for our results are large relatively to those of SYO. The difference may be due to either different incident angle or more complex anisotropic structure. We found that fast polarization direction is systematically parallel to coast line in the Lutzow-Holm Bay, East Antarctica, which is consistent with NE-SW paleo compressional stress. The absolute plate motion based on the HS2-NUVEL1 (Gripp and Gordon, 1990), that may reflect the present horizontal mantle flow, shows the direction of N120°E and velocity of 1cm/yr in this study region. Since it doesn't coincide with fast polarization direction (the difference is about 50°~90°), we conclude that the mechanism of observed anisotropy is lattice preferred orientation of olivine along the mantle flow which caused NE-SW paleo compressional stress. In future works, we will accomplish the analysis assumed more complex anisotropy systems, such as a two layer model of azimuthal anisotropy, because we could find there is the possibility of azimuthal variations of the splitting parameters in a few station.

  9. Compact High-Resolution Broad-Band Terahertz Fabry-Perot Spectrometer Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Our objective is to develop a compact scanning Fabry-Perot spectrometer, for satellite far-infrared astronomy and Earth remote sensing, that operates at wavelengths...

  10. Broad-band Gaussian noise is most effective in improving motor performance and is most pleasant.

    Science.gov (United States)

    Trenado, Carlos; Mikulić, Areh; Manjarrez, Elias; Mendez-Balbuena, Ignacio; Schulte-Mönting, Jürgen; Huethe, Frank; Hepp-Reymond, Marie-Claude; Kristeva, Rumyana

    2014-01-01

    Modern attempts to improve human performance focus on stochastic resonance (SR). SR is a phenomenon in non-linear systems characterized by a response increase of the system induced by a particular level of input noise. Recently, we reported that an optimum level of 0-15 Hz Gaussian noise applied to the human index finger improved static isometric force compensation. A possible explanation was a better sensorimotor integration caused by increase in sensitivity of peripheral receptors and/or of internal SR. The present study in 10 subjects compares SR effects in the performance of the same motor task and on pleasantness, by applying three Gaussian noises chosen on the sensitivity of the fingertip receptors (0-15 Hz mostly for Merkel receptors, 250-300 Hz for Pacini corpuscles and 0-300 Hz for all). We document that only the 0-300 Hz noise induced SR effect during the transitory phase of the task. In contrast, the motor performance was improved during the stationary phase for all three noise frequency bandwidths. This improvement was stronger for 0-300 Hz and 250-300 Hz than for 0-15 Hz noise. Further, we found higher degree of pleasantness for 0-300 Hz and 250-300 Hz noise bandwidths than for 0-15 Hz. Thus, we show that the most appropriate Gaussian noise that could be used in haptic gloves is the 0-300 Hz, as it improved motor performance during both stationary and transitory phases. In addition, this noise had the highest degree of pleasantness and thus reveals that the glabrous skin can also forward pleasant sensations.

  11. Detecting Lamb waves with broad-band acousto-ultrasonic signals in composite structures

    Science.gov (United States)

    Kautz, Harold E.

    1992-01-01

    Lamb waves can be produced and detected in ceramic matrix composites (CMC) and metal matrix composites (MMC) plates using the acousto-ultrasonic configuration employing broadband transducers. Experimental dispersion curves of lowest symmetric and antisymmetric modes behave in a manner analogous to the graphite/polymer theoretical curves. In this study a basis has been established for analyzing Lamb wave velocities for characterizing composite plates. Lamb wave dispersion curves and group velocities were correlated with variations in axial stiffness and shear stiffness in MMC and CMC. For CMC, interfacial shear strength was also correlated with the first antisymmetric Lamb mode.

  12. Internal entrainment and the origin of jet-related broad-band emission in Centaurus A

    CERN Document Server

    Wykes, Sarka; Karakas, Amanda I; Vink, Jorick S

    2014-01-01

    The dimensions of Fanaroff-Riley class I jets and the stellar densities at galactic centres imply that there will be numerous interactions between the jet and stellar winds. These may give rise to the observed diffuse and 'knotty' structure of the jets in the X-ray, and can also mass load the jets. We performed modelling of internal entrainment from stars intercepted by Centaurus A's jet, using stellar evolution- and wind codes. From photometry and a code-synthesised population of 12 Gyr (Z = 0.004), 3 Gyr (Z = 0.008) and 0 - 60 Myr (Z = 0.02) stars, appropriate for the parent elliptical NGC 5128, the total number of stars in the jet is ~ 8 x 10^8. Our model is energetically capable of producing the observed X-ray emission, even without young stars. We also reproduce the radio through X-ray spectrum of the jet, albeit in a downstream region with distinctly fewer young stars, and recover the mean X-ray spectral index. We derive an internal entrainment rate of ~ 2.3 x 10^-3 Msun yr^-1 which implies substantial ...

  13. A Computer Aided Broad Band Impedance Matching Technique Using a Comparison Reflectometer. Ph.D. Thesis

    Science.gov (United States)

    Gordy, R. S.

    1972-01-01

    An improved broadband impedance matching technique was developed. The technique is capable of resolving points in the waveguide which generate reflected energy. A version of the comparison reflectometer was developed and fabricated to determine the mean amplitude of the reflection coefficient excited at points in the guide as a function of distance, and the complex reflection coefficient of a specific discontinuity in the guide as a function of frequency. An impedance matching computer program was developed which is capable of impedance matching the characteristics of each disturbance independent of other reflections in the guide. The characteristics of four standard matching elements were compiled, and their associated curves of reflection coefficient and shunt susceptance as a function of frequency are presented. It is concluded that an economical, fast, and reliable impedance matching technique has been established which can provide broadband impedance matches.

  14. Molecular response of nasal mucosa to therapeutic exposure to broad-band ultraviolet radiation.

    Science.gov (United States)

    Mitchell, David; Paniker, Lakshmi; Sanchez, Guillermo; Bella, Zsolt; Garaczi, Edina; Szell, Marta; Hamid, Qutayba; Kemeny, Lajos; Koreck, Andrea

    2010-01-01

    Ultraviolet radiation (UVR) phototherapy is a promising new treatment for inflammatory airway diseases. However, the potential carcinogenic risks associated with this treatment are not well understood. UV-specific DNA photoproducts were used as biomarkers to address this issue. Radioimmunoassay was used to quantify cyclobutane pyrimidine dimers (CPDs) and (6-4) photoproducts in DNA purified from two milieus: nasal mucosa samples from subjects exposed to intranasal phototherapy and human airway (EpiAirway) and human skin (EpiDerm) tissue models. Immunohistochemistry was used to detect CPD formation and persistence in human nasal biopsies and human tissue models. In subjects exposed to broadband ultraviolet radiation, DNA damage frequencies were determined prior to as well as immediately after treatment and at increasing times post-treatment. We observed significant levels of DNA damage immediately after treatment and efficient removal of the damage within a few days. No residual damage was observed in human subjects exposed to multiple UVB treatments several weeks after the last treatment. To better understand the molecular response of the nasal epithelium to DNA damage, parallel experiments were conducted in EpiAirway and EpiDerm model systems. Repair rates in these two tissues were very similar and comparable to that observed in human skin. The data suggest that the UV-induced DNA damage response of respiratory epithelia is very similar to that of the human epidermis and that nasal mucosa is able to efficiently repair UVB induced DNA damage.

  15. Beam-based model of broad-band impedance of the Diamond Light Source

    Science.gov (United States)

    Smaluk, Victor; Martin, Ian; Fielder, Richard; Bartolini, Riccardo

    2015-06-01

    In an electron storage ring, the interaction between a single-bunch beam and a vacuum chamber impedance affects the beam parameters, which can be measured rather precisely. So we can develop beam-based numerical models of longitudinal and transverse impedances. At the Diamond Light Source (DLS) to get the model parameters, a set of measured data has been used including current-dependent shift of betatron tunes and synchronous phase, chromatic damping rates, and bunch lengthening. A matlab code for multiparticle tracking has been developed. The tracking results and analytical estimations are quite consistent with the measured data. Since Diamond has the shortest natural bunch length among all light sources in standard operation, the studies of collective effects with short bunches are relevant to many facilities including next generation of light sources.

  16. Secure communication in fiber optic systems via transmission of broad-band optical noise.

    Science.gov (United States)

    Buskila, O; Eyal, A; Shtaif, M

    2008-03-03

    We propose a new scheme for data encryption in the physical layer. Our scheme is based on the distribution of a broadband optical noise-like signal between Alice and Bob. The broadband signal is used for the establishment of a secret key that can be used for the secure transmission of information by using the one-time-pad method. We characterize the proposed scheme and study its applicability to the existing fiber-optics communications infrastructure.

  17. Optimising the design of a broad-band light source for the treatment of skin.

    Science.gov (United States)

    Clement, Marc; Daniel, Gwenaelle; Trelles, Mario

    2005-12-01

    Phototherapy has become a treatment of choice in many areas of medicine. Light can be used to deliver energy to tissue selectively targeting specific structures in order to induce the desired therapeutic outcome. The choice of optical parameters for a specific application is not simple. Wavelength, energy, exposure time and fluence can be varied and induce a wide range of tissue effects. The treatment of the skin with light is probably the one phototherapy application that is most developed in terms of technology and market maturity. White light systems are extensively used to address a range of skin conditions. However, different conditions have different physiology and hence require differing optical parameters. The technology standard is based upon systems, which have a number of different optical filters allowing the output to be tailored to the specific application. This paper discusses the advantages of a different type of system, namely the iPulse i300 (Cyden Ltd, Swansea, UK), which uses a single dichroic reflectance filter and whose optical output is changed by varying other parameters in a carefully controlled manner.

  18. The redshift and broad band spectral energy distribution of NRAO 150

    CERN Document Server

    Acosta-Pulido, J A; Barrena, R; Almeida, C Ramos; Manchado, A; Rodríguez-Gil, P

    2010-01-01

    Context. NRAO 150 is one of the brightest radio and mm AGN sources on the northern sky. It has been revealed as an interesting source where to study extreme relativistic jet phenomena. However, its cosmological distance has not been reported so far, because of its optical faintness produced by strong Galactic extinction. Aims. Aiming at measuring the redshift of NRAO 150, and hence to start making possible quantitative studies from the source. Methods. We have conducted spectroscopic and photometric observations of the source in the near-IR, as well as in the optical. Results. All such observations have been successful in detecting the source. The near-IR spectroscopic observations reveal strong H$\\alpha$ and H$\\beta$ emission lines from which the cosmological redshift of NRAO 150 ($z=1.517\\pm0.002$) has been determined for the first time. We classify the source as a flat-spectrum radio-loud quasar, for which we estimate a large super-massive black-hole mass $\\sim5\\times 10^{9} \\mathrm{M_\\odot}$. After extinc...

  19. Broad-Band Tunability of a Far-Infrared Free-Electron Laser

    NARCIS (Netherlands)

    Bakker, R. J.; van der Geer, C. A. J.; Jaroszynski, D. A.; van der Meer, A. F. G.; Oepts, D.; van Amersfoort, P. W.

    1993-01-01

    A unique property of the free-electron laser (FEL) is its capability to be tuned continuously over a wide spectral range. This is a major difference with all other high-power lasers. However, the tunability of first-generation FELs used to be quite poor (typically 10% or less), due to constraints im

  20. The broad-band spectrum of Cygnus X-1 measured by INTEGRAL

    CERN Document Server

    Bel, M C; Goldwurm, A; Rodríguez, J; Laurent, P; Zdziarski, A A; Foschini, L; Goldoni, P; Gouiffes, C; Malzac, J; Jourdain, E; Roques, J P

    2005-01-01

    The INTEGRAL satellite extensively observed the black hole binary Cygnus X-1 from 2002 November to 2004 November during calibration, open time and core program (Galactic Plane Scan) observations. These data provide evidence for significant spectral variations over the period. In the framework of the accreting black hole phenomenology, the source was most of the time in the Hard State and occasionally switched to the so-called "Intermediate State". Using the results of the analysis performed on these data, we present and compare the spectral properties of the source over the whole energy range (5 keV - 1 MeV) covered by the high-energy instruments on board INTEGRAL, in both observed spectral states. Fe line and reflection component evolution occurs with spectral changes in the hard and soft components. The observed behaviour of Cygnus X-1 is consistent with the general picture of galactic black holes. Our results give clues to the physical changes that took place in the system (disc and corona) at almost const...

  1. Broad-band colors and overall photometric properties of template galaxy models from stellar population synthesis

    CERN Document Server

    Buzzoni, A

    2005-01-01

    We present here a new set of evolutionary population synthesis models for template galaxies along the Hubble morphological sequence. The models, that account for the individual evolution of the bulge, disk, and halo components, provide basic morphological features, along with bolometric luminosity and color evolution (including Johnson/Cousins "UBVRcIcJHK", Gunn "gri", and Washington "CMT1T2" photometric systems) between 1 and 15 Gyr. Luminosity contribution from residual gas is also evaluated, both in terms of nebular continuum and Balmer-line enhancement.

  2. Broad-band colors and overall photometric properties of template galaxy models from stellar population synthesis

    OpenAIRE

    Buzzoni, Alberto

    2005-01-01

    We present here a new set of evolutionary population synthesis models for template galaxies along the Hubble morphological sequence. The models, that account for the individual evolution of the bulge, disk, and halo components, provide basic morphological features, along with bolometric luminosity and color evolution (including Johnson/Cousins "UBVRcIcJHK", Gunn "gri", and Washington "CMT1T2" photometric systems) between 1 and 15 Gyr. Luminosity contribution from residual gas is also evaluate...

  3. Broad-band short term X-ray spectral variability of the quasar PDS 456

    Science.gov (United States)

    Matzeu, G.; Reeves, J.; Nardini, E.; Braito, V.; Costa, M.; Tombesi, F.

    2015-07-01

    We present an analysis of a recent 500 ks Suzaku observation, carried out in 2013, of the nearby (z=0.184) luminous (L_{bol}˜10^{47} erg s^{-1}) quasar PDS 456 in which the X-ray flux was unusually low. Short term X-ray spectral variability has been detected, which may be caused by two variable coverers of column density log (N_{H,1}/cm^{-2})=22.3±0.1 and log (N_{H,2}/cm(-2) )=23.2±0.1 We find that the partial covering requires an outflow velocity of ˜0.25 c, coincident with the velocity of the highly ionised outflow at the 99.9 % confidence level. Therefore the partial covering clouds could be the denser clumpy part of an inhomogeneous wind. An obscuration event occurs 1250 ks into the observation, where the spectrum becomes totally opaque at Fe K. This implies that the size of the absorber and likewise the X-ray emitter, to be less than 20 Rg. We also analyse the flaring behaviour in the lightcurve. The behaviour of the soft and hard X-ray flux, suggested a corona characterised by an extended "warm" region of ˜20 Rg in size combined with more compact regions of "hot" electrons of ˜8 Rg in size.

  4. Algorithm Development for Measurement and Prediction the Traffic in Broad Band Integrated Service Networks

    Directory of Open Access Journals (Sweden)

    Mohammad A. Rawajbeh

    2010-01-01

    Full Text Available Problem statement: In this study an effort had been made to develop an algorithm for traffic prediction and measurement for a wide use networks such as B-ISDN. Such algorithm should base on valuable parameters during the various stages of data elements transmission. The offered algorithm was expected to enforce the main sources of congestion problem in network. With this technique the admission decision is made according to the prediction of a few quality of service parameters expected for the new connections. Approach: This research aimed to find out the suitable method for improving the performance and the quality of service during the real time work in wide used networks now days. The improvement of quality of services in B-ISDN can be achieved by a significant estimation of the network state and discovering the most critical situation during the work time. The most repeated problems in such networks are loses of connection, delay time and saturation of communication lines. These problems are known and some solution could be sufficient to deal with, but not for a long time. Results: The proposed solution was based on the need of traffic prediction method in real time to determine the state of network and decide how to deal with. Such method should base on finding the most significant parameters in network during the real time work and use them as prediction variable to predict the situation or the state of network in the future time and then take the appropriate action. Suffering from permanent problems finding the most significant parameters, which can be estimated at the real time to help for solving a raw problems which encountered during the work in networks such as saturation, bottleneck, disconnecting and time delay. Conclusion: The results which achieved by this research was based on the developed algorithm which can be used to predict the traffic in B-ISDN, optimizing the bandwidth and making the bandwidth available to the behaving sources under congestion situation and also when there is no congestion. Meet the QoS demands of the network traffic during congestion situation and also when there is no congestion. Reject/drop all the packets. First guideline for future study in this direction is investigation additional objective functions, such as bandwidth limitation for archive more general results.

  5. Broad-band chopper for a CW proton linac at Fermilab

    Energy Technology Data Exchange (ETDEWEB)

    Gianfelice-Wendt, E.; Lebedev, V.A.; Solyak, N.; Nagaitsev, S.; Sun, D.; /Fermilab

    2011-03-01

    The future Fermilab program in the high energy physics is based on a new facility called the Project X [1] to be built in the following decade. It is based on a 3 MW CW linear accelerator delivering the 3 GeV 1 mA H{sup -} beam to a few experiments simultaneously. Small fraction of this beam will be redirected for further acceleration to 8 GeV to be injected to the Recycler/Main Injector for a usage in a neutrino program and other synchrotron based high energy experiments. Requirements and technical limitations to the bunch-by-bunch chopper for the Fermilab Project X are discussed.

  6. Microcalorimeters for broad band high resolution X-ray spectral analysis

    Energy Technology Data Exchange (ETDEWEB)

    LeGros, Mark (Laboratory For Experimental Astrophysics, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94550 (United States)); Silver, Eric (Laboratory For Experimental Astrophysics, Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94550 (United States)); Madden, Norman (Lawrence Berkeley Laboratory, Berkeley (United States)); Beeman, Jeffrey (Lawrence Berkeley Laboratory, Berkeley (United States)); Goulding, Frederick (Lawrence Berkeley Laboratory, Berkeley (United States)); Landis, Donald (Lawrence Berkeley Laboratory, Berkeley (United States)); Haller, Eugene (Lawrence Berkeley Laboratory, Berkeley (United States))

    1994-07-01

    A large area microcalorimeter with 95% quantum efficiency at 6 keV has been developed. When fully illuminated, it produces X-ray spectra between 0.5 and 7 keV with an energy resolution of 23 eV. On a smaller, but similar detector, we measure 18 eV. The resolution is obtained at input count rates of 10-50 Hz in real-time with analog pulse processing and thermal pile-up rejection. The detector is incorporated into a compact and portable cryogenic refrigerator system that is ready for use as a tool for analytical spectroscopy. ((orig.))

  7. A broad-Band FT-ICR Penning TRap System for KATRIN

    CERN Document Server

    Ubieto-Diaz, M; Lukic, S; Nagy, Sz; Stahl, S; Blaum, K

    2009-01-01

    The KArlsruhe TRItium Neutrino experiment KATRIN aims at improving the upper limit of the mass of the electron antineutrino to about 0.2 eV (90% c.l.) by investigating the beta-decay of tritium gas molecules. The experiment is currently under construction to start first data taking in 2012. One source of systematic uncertainties in the KATRIN experiment is the formation of ion clusters when tritium decays and decay products interact with residual tritium molecules. It is essential to monitor the abundances of these clusters since they have different final state energies than tritium ions. For this purpose, a prototype of a cylindrical Penning trap has been constructed and tested at the Max-Planck-Institute for Nuclear Physics in Heidelberg, which will be installed in the KATRIN beam line. This system employs the technique of Fourier-Transform Ion-Cyclotron-Resonance in order to measure the abundances of the different stored ion species.

  8. A Class of Broad-Band Dissipative Matching Networks Designed on an Insertion-Loss Basis

    Science.gov (United States)

    1952-01-25

    34" "~3Ö MMnaaaHapiKiNX-’jM ÜM85F PLEASE RETURN THIS COPY f-D- ARMED SERVICES TECHNICAL /NFCkuT/OttAGEfCY D(KUMEimSERy!CECMmR ^ Knott Building...nee;d be- taken. This, haä been ^RßfÄliti^: c Report &~0i.*$2, FIB -2Q3 Contract ;J!o;=, NÖDsa?«i Page 11 ! f indicated by the heavy lines in...Make, corrections in,~^ the .läcujj> f o~^^ circular !ärc;i - - • -: : - ; ’I i •••<::A ~f -n ;. t: Report Ä«-26fe£2* FIB * 203 •Göhtract No

  9. Swift broad band observations of the Black Hole transient GRS 1716-249

    Science.gov (United States)

    Del Santo, Melania; D'Ai', Antonino; Bassi, Tiziana; Segreto, Alberto; Belloni, Tomaso; Cusumano, Giancarlo; Parola, Valentina La

    2017-02-01

    We report on Swift observations of the ongoing outburst of the Black Hole Transient (BHT) GRS 1716-249 (ATel #9876, #9895). We analyzed both XRT and BAT data of three Swift ToO pointings performed on 2017 January 28, 29 and 30 (Target ID 34924, segments 1, 2, 3). The XRT count rate is about 90 count/s and therefore the observations have been performed in window-timing mode.

  10. The Solar Shield: A Thermally Insulating, Broad-Band, Electromagnetic Window for Satellites

    Science.gov (United States)

    1986-06-02

    usually somewhat puckered , instead of lying flat, and in addition to the fact that the netting between sandwiches is often somewhat wrinkled, there is...On the front of each of the secondary envelopes three separating layers of polyester mesh (See Table I) shall be installed. Sew a polyester seam on the

  11. A new method for detemining the Angstrom turbidity coefficient from broad-band filter measurements.

    OpenAIRE

    Utrillas Esteban, Mª Pilar; Pedrós Esteban, Roberto; Martínez Lozano, José Antonio; Tena Sangüesa, Fernando

    2000-01-01

    In this work, a new method for determining Ångström turbidity coefficients is presented. This method is based on broadband filter irradiance measurements. By combining measurements obtained with different filters it is possible to obtain a single value of the turbidity coefficient representative of the whole measurement range of the pyrheliometer. The results provided by this new method are compared with the original Ångström method and turbidity coefficient values derived by spectroradiometr...

  12. A concept of advanced broad-band solid-state supermirror polarizers for cold neutrons

    Science.gov (United States)

    Petukhov, A. K.; Nesvizhevsky, V. V.; Bigault, T.; Courtois, P.; Jullien, D.; Soldner, T.

    2016-12-01

    An ideal solid-state supermirror (SM) neutron polarizer assumes total reflection of neutrons from the SM coating for one spin-component and total absorption for the other, thus providing a perfectly polarized neutron beam at the exit. However, in practice, the substrate's neutron-nuclei optical potential does not match perfectly that for spin-down neutrons in the SM. For a positive step in the optical potential (as in a Fe / Si Nx SM on Si substrate), this mismatch results in spin-independent total reflection for neutrons with small momentum transfer Q , limiting the useful neutron bandwidth in the low- Q region. To overcome this limitation, we propose to replace Si single-crystal substrates by media with higher optical potential than that for spin-down neutrons in the SM ferromagnetic layers. We found single-crystal sapphire and single-crystal quartz as good candidates for solid-state Fe / Si Nx SM polarizers. To verify this idea, we coated a thick plate of single-crystal sapphire with a m = 2.5 Fe / Si Nx SM. At the T3 instrument at the ILL, we measured the spin-up and spin-down reflectivity curves with λ = 7.5 Å neutrons incident from the substrate to the interface between the substrate and the SM coating. Results of this experimental test are in excellent agreement with our expectations: the bandwidth of high polarizing power extends significantly into the low- Q region. This finding, together with the possibility to apply a strong magnetizing field, opens a new road to produce high-efficiency solid-state SM polarizers with an extended neutron wavelength bandwidth and near-to-perfect polarizing power.

  13. Optimized Variational 1D Boussinesq Modelling for broad-band waves over flat bottom

    NARCIS (Netherlands)

    Lakhturov, I.; Adytia, D.; Groesen, van E.

    2012-01-01

    The Variational Boussinesq Model (VBM) for waves above a layer of ideal fluid conserves mass, momentum, energy, and has decreased dimensionality compared to the full problem. It is derived from the Hamiltonian formulation via an approximation of the kinetic energy, and can provide approximate disper

  14. Optimized variational Boussinesq modelling; part 1: Broad-band waves over flat bottom

    NARCIS (Netherlands)

    Lakhturov, I.; Groesen, van E.

    2010-01-01

    The Variational Boussinesq Model (VBM) for waves above a layer of ideal fluid conserves mass, momentum, energy, and has decreased dimensionality compared to the full problem. It is derived from the Hamiltonian formulation via an approximation of the kinetic energy, and can provide approximate disper

  15. Broad-band Gausssian noise is most effective in improving motor performance and is most pleasant

    Directory of Open Access Journals (Sweden)

    Carlos eTrenado

    2014-02-01

    Full Text Available Modern attempts to improve human performance focus on stochastic resonance (SR. SR is a phenomenon in nonlinear systems characterized by a response increase of the system induced by a particular level of input noise. Recently, we reported that an optimum level of 0-15 Hz Gaussian noise applied to the human index finger improved static isometric force compensation. A possible explanation was a better sensorimotor integration caused by increase in sensitivity of peripheral receptors and/or of internal SR. The present study in 10 subjects compares SR effects in the performance of the same motor task and on pleasantness, by applying three Gaussian noises chosen on the sensitivity of the fingertip receptors (0-15 Hz mostly for Merkel receptors, 250-300 Hz for Pacini corpuscules and 0-300 Hz for all. We document that only the 0-300 Hz noise induced SR effect during the transitory phase of the task. In contrast, the motor performance was improved during the stationary phase for all three noise frequency bandwidths. This improvement was stronger for 0-300 Hz and 250-300 Hz than for 0-15 Hz noise. Further, we found higher degree of pleasantness for 0-300 Hz and 250-300 Hz noise bandwidths than for 0-15 Hz. Thus, we show that the most appropriate Gaussian noise that could be used in haptic gloves is the 0-300 Hz, as it improved motor performance during both stationary and transitory phases. In addition, this noise had the highest degree of pleasantness and thus reveals that the glabrous skin can also forward pleasant sensations. These new findings provide worthy information for neurorehabilitation.

  16. Experimental estimations of viscoelastic properties of multilayer damped plates in broad-band frequency range

    CERN Document Server

    Ege, Kerem; Laulagnet, Bernard; Guyader, Jean-Louis

    2012-01-01

    Regarding lightweighting structures for aeronautics, automotive or construction applications, the level of performance of solutions proposed in terms of damping and isolation is fundamental. Hence multilayered plate appears as an interesting answer if damping performances are properly optimized. In this paper, a novel modal analysis method (Ege et al, JSV 325 (4-5), 2009) is used to identify viscoelastic properties (loss factors, Young's modulus) of "polyethylene thermoplastic / aluminum" bilayer plates. The thermoplastic is chosen for its high loss factors and relative low mass. The experimental method consists in a high-resolution technique (ESPRIT algorithm) which allows precise estimations of the viscoelastic properties even in frequency domains with high modal overlap (high damping or modal density). Experimental loss factors estimated from impact hammer excitations on the free-free plates highly corresponds with two theoretical estimations. In the first model (Guyader & Lesueur, JSV 58(1), 1978) the...

  17. Advanced broad-band solid-state supermirror polarizers for cold neutrons

    CERN Document Server

    Petukhov, A K; Bigault, T; Courtois, P; Jullien, D; Soldner, T

    2016-01-01

    An ideal solid-state supermirror (SM) neutron polarizer assumes total reflection of neutrons from the SM coating for one spin-component and total absorption for the other, thus providing a perfectly polarized neutron beam at the exit. However, in practice, the substrate's neutron-nucleai optical potential does not match perfectly that for spin-down neutrons in the SM. For a positive step in the optical potential (as in a Fe/SiN(x) SM on Si substrate), this mismatch results in spin-independent total reflection for neutrons with small momentum transfer Q, limiting the useful neutron bandwidth in the low-Q region. To overcome this limitation, we propose to replace Si single-crystal substrates by media with higher optical potential than that for spin-down neutrons in the SM ferromagnetic layers. We found single-crystal sapphire and single-crystal quartz as good candidates for solid-state Fe/SiN(x) SM polarizers. To verify this idea, we coated a thick plate of single-crystal sapphire with a m=2.4 Fe/SiN(x) SM. At ...

  18. The design of broad band anti-reflection coatings for solar cell applications

    Science.gov (United States)

    Siva Rama Krishna, Angirekula; Sabat, Samrat Lagnajeet; Ghanashyam Krishna, Mamidipudi

    2017-01-01

    The design of broadband anti-reflection coatings (ARCs) for solar cell applications using multiobjective differential evolutionary (MODE) algorithms is reported. The effect of thickness and refractive index contrast within the layers of the ARC on the bandwidth of reflectance is investigated in detail. In the case of the hybrid plasmonic ARC structures the effect of size, shape and filling fraction of silver (Ag) nanoparticles on the reflectance is studied. Bandwidth is defined as the spectral region of wavelengths over which the reflectance is below 2%. Single, two and three layers ARCs (consisting of MgF2, Al2O3, Si3N4, TiO2 and ZnS or combinations of these materials) were simulated for performance evaluation on an a-Si photovoltaic cell. It is observed that the three layer ARC consisting of MgF2/Si3N4/TiO2(ZnTe) of 81/42/36 nm thicknesses, respectively, exhibited a weighted reflectance of 1.9% with a bandwidth of 450 nm over the wavelength range of 300-900 nm. The ARC bandwidth could be further improved by embedding randomly distributed Ag nanoparticles of size between 100 and 120 nm on a two layer ARC consisting of Al2O3/TiO2 with thickness of 42 nm and 56 nm respectively. This plasmon-dielectric hybrid ARC design exhibited a weighted reflectance of 0.6% with a bandwidth of 560 nm over the wavelength range of 300-900 nm.

  19. 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.

  20. ZEBRAFISH CHROMOSOME-BANDING

    NARCIS (Netherlands)

    PIJNACKER, LP; FERWERDA, MA

    1995-01-01

    Banding techniques were carried out on metaphase chromosomes of zebrafish (Danio rerio) embryos. The karyotypes with the longest chromosomes consist of 12 metacentrics, 26 submetacentrics, and 12 subtelocentrics (2n = 50). All centromeres are C-band positive. Eight chromosomes have a pericentric C-b

  1. Stretch Band Exercise Program

    Science.gov (United States)

    Skirka, Nicholas; Hume, Donald

    2007-01-01

    This article discusses how to use stretch bands for improving total body fitness and quality of life. A stretch band exercise program offers a versatile and inexpensive option to motivate participants to exercise. The authors suggest practical exercises that can be used in physical education to improve or maintain muscular strength and endurance,…

  2. Progressive Band Selection

    Science.gov (United States)

    Fisher, Kevin; Chang, Chein-I

    2009-01-01

    Progressive band selection (PBS) reduces spectral redundancy without significant loss of information, thereby reducing hyperspectral image data volume and processing time. Used onboard a spacecraft, it can also reduce image downlink time. PBS prioritizes an image's spectral bands according to priority scores that measure their significance to a specific application. Then it uses one of three methods to select an appropriate number of the most useful bands. Key challenges for PBS include selecting an appropriate criterion to generate band priority scores, and determining how many bands should be retained in the reduced image. The image's Virtual Dimensionality (VD), once computed, is a reasonable estimate of the latter. We describe the major design details of PBS and test PBS in a land classification experiment.

  3. Wide band polarizer with suspended germanium resonant grating

    Institute of Scientific and Technical Information of China (English)

    Wugang Cao; Jianyong Ma; Changhe Zhou

    2012-01-01

    An ultra broad band polarizer that operates in the telecommunication wavelength band is proposed.This device,which consists of a single suspended germanium resonant grating layer,is designed using the inverse mathematical method and the rigorous vector diffraction theory.Calculated results indicate that the ultra broad band polarizer exhibits extremely high reflection (R > 99%) for TE polarization light and high transmission (T > 99%) for TM polarization at the wavelength range greater than 300 nm,and it has an extinction ratio of approximately 1 000 at the 1 550-nm central wavelength.The results of the rigorous coupled wave analysis indicate that the extremely wide band property of the TE polarization is caused by the excitation of strong modulation guided modes in the design wavelength range.

  4. Narrow line Seyfert 1 galaxies: where are the broad line regions?

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A sample consisting of 211 narrow line Seyfert 1 galaxies (NLS1s) with high quality spectra from the Sloan Digital Sky Survey (SDSS) is selected to explore where broad line regions are in these objects. We find that the Hβ profile can be fitted well by three (narrow, intermediate and broad) Gaussian components, and the FWHM ratios of the broad to the intermediate components hold a constant of 3.0 roughly for the entire sample. If the broad components originate from the region scaled by the well-determined Hβ reverberation mapping relation, we find that the intermediate components originate from the inner edge of the torus, which is scaled by dust K-band reverberation. We find that the IC and the BC are strongly linked dynamically, but the relation of their covering factors is much more relaxed, implying that both regions are clumpy.

  5. Giant Broad Line Regions in Dwarf Seyferts

    CERN Document Server

    Devereux, Nick

    2015-01-01

    High angular resolution spectroscopy obtained with the Hubble Space Telescope (HST) has revealed a remarkable population of galaxies hosting dwarf Seyfert nuclei with an unusually large broad-line region (BLR). These objects are remarkable for two reasons. Firstly, the size of the BLR can, in some cases, rival those seen in the most luminous quasars. Secondly, the size of the BLR is not correlated with the central continuum luminosity, an observation that distinguishes them from their reverberating counterparts. Collectively, these early results suggest that non-reverberating dwarf Seyferts are a heterogeneous group and not simply scaled versions of each other. Careful inspection reveals broad H Balmer emission lines with single peaks, double peaks, and a combination of the two, suggesting that the broad emission lines are produced in kinematically distinct regions centered on the black hole (BH). Because the gravitational field strength is already known for these objects, by virtue of knowing their BH mass, ...

  6. Modelling Demand for Broad Money in Australia

    OpenAIRE

    Abbas Valadkhani

    2002-01-01

    The existence of a stable demand for money is very important for the conduct of monetary policy. It is argued that previous work on the demand for money in Australia has not been very satisfactory in a number of ways. This paper examines the long- and short-run determinants of the demand for broad money employing the Johansen cointegration technique and a short-run dynamic model. Using quarterly data for the period 1976:3-2002:2, this paper finds, inter alia, that the demand for broad money i...

  7. Iliotibial band friction syndrome.

    Science.gov (United States)

    Lavine, Ronald

    2010-07-20

    Published articles on iliotibial band friction syndrome have been reviewed. These articles cover the epidemiology, etiology, anatomy, pathology, prevention, and treatment of the condition. This article describes (1) the various etiological models that have been proposed to explain iliotibial band friction syndrome; (2) some of the imaging methods, research studies, and clinical experiences that support or call into question these various models; (3) commonly proposed treatment methods for iliotibial band friction syndrome; and (4) the rationale behind these methods and the clinical outcome studies that support their efficacy.

  8. Teaching the Broad, Interdisciplinary Impact of Evolution

    Science.gov (United States)

    Benson, David; Atlas, Pierre; Haberski, Raymond; Higgs, Jamie; Kiley, Patrick; Maxwell, Michael, Jr.; Mirola, William; Norton, Jamey

    2009-01-01

    As perhaps the most encompassing idea in biology, evolution has impacted not only science, but other academic disciplines as well. The broad, interdisciplinary impact of evolution was the theme of a course taught at Marian College, Indianapolis, Indiana in 2002, 2004, and 2006. Using a strategy that could be readily adopted at other institutions,…

  9. Diet after gastric banding

    Science.gov (United States)

    ... helps people who have a gastric band stay satisfied longer. This includes things like salad with grilled ... ADAM Health Solutions. About MedlinePlus Site Map FAQs Customer Support Get email updates Subscribe to RSS Follow ...

  10. HYBASE - HYperspectral BAnd SElection tool

    NARCIS (Netherlands)

    Schwering, P.B.W.; Bekman, H.H.P.T.; Seijen, H.H. van

    2008-01-01

    Band selection is essential in the design of multispectral sensor systems. This paper describes the TNO hyperspectral band selection tool HYBASE. It calculates the optimum band positions given the number of bands and the width of the spectral bands. HYBASE is used to calculate the minimum number of

  11. Broadly Neutralizing Antibodies for HIV Eradication.

    Science.gov (United States)

    Stephenson, Kathryn E; Barouch, Dan H

    2016-02-01

    Passive transfer of antibodies has long been considered a potential treatment modality for infectious diseases, including HIV. Early efforts to use antibodies to suppress HIV replication, however, were largely unsuccessful, as the antibodies that were studied neutralized only a relatively narrow spectrum of viral strains and were not very potent. Recent advances have led to the discovery of a large portfolio of human monoclonal antibodies that are broadly neutralizing across many HIV-1 subtypes and are also substantially more potent. These antibodies target multiple different epitopes on the HIV envelope, thus allowing for the development of antibody combinations. In this review, we discuss the application of broadly neutralizing antibodies (bNAbs) for HIV treatment and HIV eradication strategies. We highlight bNAbs that target key epitopes, such as the CD4 binding site and the V2/V3-glycan-dependent sites, and we discuss several bNAbs that are currently in the clinical development pipeline.

  12. Multiple and broad frequency response Gunn diodes

    Science.gov (United States)

    Pilgrim, N. J.; Macpherson, R. F.; Khalid, A.; Dunn, G. M.; Cumming, D. R. S.

    2009-10-01

    Gunn diodes, operating in transit time mode, are usually thought of as incapable of generating power at multiple frequencies or over a broad frequency range. In this paper, we report experimental results showing that these diodes can generate power at several frequencies and, using Monte Carlo simulations of both planar and vertical devices, we offer an explanation of how this unusual behaviour may come into being and suggest possible applications for this novel device.

  13. Photonic band gap materials

    Science.gov (United States)

    Cassagne, D.

    Photonic band gap materials Photonic band gap materials are periodic dielectric structures that control the propagation of electromagnetic waves. We describe the plane wave method, which allows to calculate the band structures of photonic crystals. By symmetry analysis and a perturbative approach, we predict the appearance of the low energy photonic band gaps of hexagonal structures. We propose new two-dimensional structures called graphite and boron nitride. Using a transfer matrix method, we calculate the transmission of the graphite structure and we show the crucial role of the coupling with external modes. We study the appearance of allowed modes in the photonic band gap by the introduction of localized defects in the periodicity. Finally, we discuss the properties of opals formed by self-organized silica microspheres, which are very promising for the fabrication of three-dimensional photonic crystals. Les matériaux à bandes interdites photoniques sont des structures diélectriques périodiques qui contrôlent la propagation des ondes électromagnétiques. Nous décrivons la méthode des ondes planes qui permet de calculer les structures de bandes des cristaux photoniques. Par une analyse de la symétrie et une approche perturbative, nous précisons les conditions d'existence des bandes interdites de basse énergie. Nous proposons de nouvelles structures bidimensionnelles appelées graphite et nitrure de bore. Grâce à une méthode de matrices de transfert, nous calculons la transmission de la structure graphite et nous mettons en évidence le rôle fondamental du couplage avec les modes extérieurs. Nous étudions l'apparition de modes permis dans la bande interdite grâce à l'introduction de défauts dans la périodicité. Enfin, nous discutons les propriétés des opales constituées de micro-billes de silice auto-organisées, qui sont très prometteuses pour la fabrication de cristaux photoniques tridimensionnels.

  14. A wide-band Gunn-effect CW waveguide amplifier.

    Science.gov (United States)

    Sene, A.; Rosenbaum, F. J.

    1972-01-01

    Broad-band CW amplification with Gunn diodes in waveguide circuits has been obtained, with power gains typically between 10 and 15 dB and half-power bandwidths of more than 1 GHz. It is found that amplifier performance can be modeled with fair accuracy using a rough characterization for the diode parameters.

  15. Suicidal ligature strangulation using gymnastics bands.

    Science.gov (United States)

    Tzimas, Iliana; Bajanowski, Thomas; Pollak, Stefan; Trübner, Kurt; Thierauf, Annette

    2014-03-01

    Suicidal ligature strangulation is a rare event. The most important issue to solve in the investigation is whether it is a case of homicide or suicide. The characteristics of suicidal ligature strangulation are summarized by Koops and Brinkmann with the emphasis on the nature of the ligature instrument(s). In this article, we present two cases of self-strangulation with an almost identical modus operandi using gymnastics bands. The autopsy findings and the nature of the ligature in these cases are depicted and in good accordance with the described typical observations in suicidal cases. The importance of a broad medico-legal investigation is demonstrated.

  16. Distribution Free Prediction Bands

    CERN Document Server

    Lei, Jing

    2012-01-01

    We study distribution free, nonparametric prediction bands with a special focus on their finite sample behavior. First we investigate and develop different notions of finite sample coverage guarantees. Then we give a new prediction band estimator by combining the idea of "conformal prediction" (Vovk et al. 2009) with nonparametric conditional density estimation. The proposed estimator, called COPS (Conformal Optimized Prediction Set), always has finite sample guarantee in a stronger sense than the original conformal prediction estimator. Under regularity conditions the estimator converges to an oracle band at a minimax optimal rate. A fast approximation algorithm and a data driven method for selecting the bandwidth are developed. The method is illustrated first in simulated data. Then, an application shows that the proposed method gives desirable prediction intervals in an automatic way, as compared to the classical linear regression modeling.

  17. To Broad-Match or Not to Broad-Match : An Auctioneer's Dilemma ?

    CERN Document Server

    Singh, Sudhir Kumar

    2008-01-01

    We initiate the study of an interesting aspect of sponsored search advertising, namely the consequences of broad match-a feature where an ad of an advertiser can be mapped to a broader range of relevant queries, and not necessarily to the particular keyword(s) that ad is associated with. Starting with a very natural setting for strategies available to the advertisers, and via a careful look through algorithmic and complexity theoretic glasses, we first propose a solution concept called broad match equilibrium(BME) for the game originating from the strategic behavior of advertisers as they try to optimize their budget allocation across various keywords. Next, we consider two broad match scenarios based on factors such as information asymmetry between advertisers and the auctioneer, and the extent of auctioneer's control on the budget splitting. In the first scenario, the advertisers have the full information about broad match and relevant parameters, and can reapportion their own budgets to utilize the extra i...

  18. 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

  19. Crx broadly modulates the pineal transcriptome

    DEFF Research Database (Denmark)

    Rovsing, Louise; Clokie, Samuel; Bustos, Diego M;

    2011-01-01

    Cone-rod homeobox (Crx) encodes Crx, a transcription factor expressed selectively in retinal photoreceptors and pinealocytes, the major cell type of the pineal gland. In this study, the influence of Crx on the mammalian pineal gland was studied by light and electron microscopy and by use......-regulation of 745 genes (p pineal glands of wild......-type animals; only eight of these were also day/night expressed in the Crx-/- pineal gland. However, in the Crx-/- pineal gland 41 genes exhibited differential night/day expression that was not seen in wild-type animals. These findings indicate that Crx broadly modulates the pineal transcriptome and also...

  20. Broad spectrum antibiotic compounds and use thereof

    Energy Technology Data Exchange (ETDEWEB)

    Koglin, Alexander; Strieker, Matthias

    2016-07-05

    The discovery of a non-ribosomal peptide synthetase (NRPS) gene cluster in the genome of Clostridium thermocellum that produces a secondary metabolite that is assembled outside of the host membrane is described. Also described is the identification of homologous NRPS gene clusters from several additional microorganisms. The secondary metabolites produced by the NRPS gene clusters exhibit broad spectrum antibiotic activity. Thus, antibiotic compounds produced by the NRPS gene clusters, and analogs thereof, their use for inhibiting bacterial growth, and methods of making the antibiotic compounds are described.

  1. FTIR Study of White and Green Broad Beans Based on Curve-fitting

    Institute of Scientific and Technical Information of China (English)

    Xiaohua; WANG; Gang; LIU; Quanhong; OU; Xingxiang; ZHAO; Jianming; HAO; Xiangping; ZHOU

    2013-01-01

    Fourier transform infrared(FTIR)spectroscopy was used to study two kinds of broad beans with white and green cotyledons respectively.The results show that the infrared spectra of the two kinds of broad beans are similar and mainly made up of the absorption bands of protein,and polysaccharides.The second derivative infrared spectra amplified the differences and revealed that there were some obvious differences in the range of 1 800-700 cm-1and 1 200-700 cm-1.Hierarchical cluster analysis(HCA)were used for the discrimination of the two kinds broad beans based on the second derivative spectral data in the region of 1 611-1 100 cm-1,and yielded 88.9%accuracy.The spectra in the range from 1 700 to 1 600 cm-1were used to perform Fourier self-deconvolution and curve fitting,which obtained nine peaks.The ratios of relative areas of the bands atα-helix,β-sheet,β-turn and the unordered structure of protein in white beans were 67.71%,35.6%,35.6%and 21.09%respectively,while the ratios in green beans were 8.02%,31.59%,37.12%and 23.27%respectively.The results indicate that the secondary structure of protein was different in the two kinds of broad beans.

  2. Exceptionally large banded spherulites

    Science.gov (United States)

    Lagasse, R. R.

    1994-07-01

    This article concerns the crystallization of maleic anhydride from a blend containing 2 wt% of poly(acrylonitrile). High speed photography and temperature measurements during the crystallization as well as X-ray diffraction from the blend after crystallization are consistent with a banded spherulitic morphology.

  3. DUAL BAND MONOPOLE ANTENNA DESIGN

    Directory of Open Access Journals (Sweden)

    P. Jithu

    2013-06-01

    Full Text Available The WLAN and Bluetooth applications become popular in mobile devices, integrating GSM and ISM bands operation in one compact antenna, can reduce the size of mobile devices. Recently, lot many investigations are carried out in designing a dual band antennas with operating frequencies in GSM band and in ISM band for mobile devices. Printed monopoles are under this investigation. In this paper, dual-band printed monopoles are presented to operate at GSM band i.e. 900 MHz and ISM band i.e. 2.4 GHz. We intend to observe the antenna characteristics on the network analyzer and verify the theoretical results with the practical ones.

  4. XMM-Newton and Broad Iron Lines

    CERN Document Server

    Fabian, A C

    2007-01-01

    Iron line emission is common in the X-ray spectra of accreting black holes. When the line emission is broad or variable then it is likely to originate from close to the black hole. X-ray irradiation of the accretion flow by the power-law X-ray continuum produces the X-ray 'reflection' spectrum which includes the iron line. The shape and variability of the iron lines and reflection can be used as a diagnostic of the radius, velocity and nature of the flow. The inner radius of the dense flow corresponds to the innermost stable circular orbit and thus can be used to determine the spin of the black hole. Studies of broad iron lines and reflection spectra offer much promise for understanding how the inner parts of accretion flows (and outflows) around black holes operate. There remains great potential for XMM-Newton to continue to make significant progress in this work. The need for high quality spectra and thus for long exposure times is paramount.

  5. Coded excitation and sub-band processing for blood velocity estmation in medical ultrasound

    DEFF Research Database (Denmark)

    Gran, Fredrik; Udesen, Jesper; Jensen, Jørgen Arendt

    2007-01-01

    . However, the axial resolution of the narrow-band pulse is too poor for brightness-mode (B-mode) imaging. Therefore, a separate transmission sequence is used for updating the B-mode image, which lowers the overall frame-rate of the system. By using broad-band excitation signals, the backscattered received...

  6. The broad Fe K line profile in NGC 4151

    CERN Document Server

    Wang, J; Wang, T; Wang, Junxian.; Zhou, Youyuan.; Wang, Tinggui.

    1999-01-01

    We present an analysis of the Fe K line profile of NGC 4151 by using long ASCA observation data obtained in May 1995. The unprecedented good data quality, which is much better in the energy band around 6.4 keV than that of the famous 4.2-day ASCA observation of MCG -6-30-15 in July 1994, offers a unique opportunity to study the details of Fe K line profile. Apart from those characteristics already noticed in earlier ASCA observations on this object (Yaqoob et al. 1995): a broad and skewed profile, with a strong peak at about 6.4 keV and a large red wing extending to $\\sim$4 - 5 keV, which is remarkably similar to that of MCG -6-30-15, we also find a weak blue wing extending to about 8 keV, thanks to the good quality of the data. When fitted by a relativistic accretion disk line plus a narrow core at 6.4 keV, the data constrain the accretion disk to be nearly face-on, contrary to the edge-on geometry inferred from optical and UV observations. However, the extended blue wing can not be well fitted even after we...

  7. Diffuse interstellar absorption bands

    Institute of Scientific and Technical Information of China (English)

    XIANG FuYuan; LIANG ShunLin; LI AiGen

    2009-01-01

    The diffuse interstellar bands (DIBs) are a large number of absorption bands that are superposed on the interstellar extinction curve and are of interstellar origin. Since the discovery of the first two DIBs in the 1920s, the exact nature of DIBs still remains unclear. This article reviews the history of the detec-tions of DIBs in the Milky Way and external galaxies, the major observational characteristics of DIBs, the correlations or anti-correlations among DIBs or between DIBs and other interstellar features (e.g. the prominent 2175 Angstrom extinction bump and the far-ultraviolet extinction rise), and the proposed candidate carriers. Whether they are also present in circumstellar environments is also discussed.

  8. Diffuse interstellar absorption bands

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The diffuse interstellar bands(DIBs) are a large number of absorption bands that are superposed on the interstellar extinction curve and are of interstellar origin. Since the discovery of the first two DIBs in the 1920s,the exact nature of DIBs still remains unclear. This article reviews the history of the detections of DIBs in the Milky Way and external galaxies,the major observational characteristics of DIBs,the correlations or anti-correlations among DIBs or between DIBs and other interstellar features(e.g. the prominent 2175 Angstrom extinction bump and the far-ultraviolet extinction rise),and the proposed candidate carriers. Whether they are also present in circumstellar environments is also discussed.

  9. Magnetohydrodynamic stability of broad line region clouds

    CERN Document Server

    Krause, Martin; Burkert, Andreas

    2012-01-01

    Hydrodynamic stability has been a longstanding issue for the cloud model of the broad line region in active galactic nuclei. We argue that the clouds may be gravitationally bound to the supermassive black hole. If true, stabilisation by thermal pressure alone becomes even more difficult. We further argue that if magnetic fields should be present in such clouds at a level that could affect the stability properties, they need to be strong enough to compete with the radiation pressure on the cloud. This would imply magnetic field values of a few Gauss for a sample of Active Galactic Nuclei we draw from the literature. We then investigate the effect of several magnetic configurations on cloud stability in axi-symmetric magnetohydrodynamic simulations. For a purely azimuthal magnetic field which provides the dominant pressure support, the cloud first gets compressed by the opposing radiative and gravitational forces. The pressure inside the cloud then increases, and it expands vertically. Kelvin-Helmholtz and colu...

  10. Spectrophotometry of six broad absorption line QSOs

    Science.gov (United States)

    Junkkarinen, Vesa T.; Burbidge, E. Margaret; Smith, Harding E.

    1987-01-01

    Spectrophotometric observations of six broad absorption-line QSOs (BALQSOs) are presented. The continua and emission lines are compared with those in the spectra of QSOs without BALs. A statistically significant difference is found in the emission-line intensity ratio for (N V 1240-A)/(C IV 1549-A). The median value of (N V)/(C IV) for the BALQSOs is two to three times the median for QSOs without BALs. The absorption features of the BALQSOs are described, and the column densities and limits on the ionization structure of the BAL region are discussed. If the dominant ionization mechanism is photoionization, then it is likely that either the ionizing spectrum is steep or the abundances are considerably different from solar. Collisional ionization may be a significant factor, but it cannot totally dominate the ionization rate.

  11. Micromechanics of shear banding

    Energy Technology Data Exchange (ETDEWEB)

    Gilman, J.J.

    1992-08-01

    Shear-banding is one of many instabilities observed during the plastic flow of solids. It is a consequence of the dislocation mechanism which makes plastic flow fundamentally inhomogeneous, and is exacerbated by local adiabatic heating. Dislocation lines tend to be clustered on sets of neighboring glide planes because they are heterogeneously generated; especially through the Koehler multiple-cross-glide mechanism. Factors that influence their mobilities also play a role. Strain-hardening decreases the mobilities within shear bands thereby tending to spread (delocalize) them. Strain-softening has the inverse effect. This paper reviews the micro-mechanisms of these phenomena. It will be shown that heat production is also a consequence of the heterogeneous nature of the microscopic flow, and that dislocation dipoles play an important role. They are often not directly observable, but their presence may be inferred from changes in thermal conductivity. It is argued that after deformation at low temperatures dipoles are distributed a la Pareto so there are many more small than large ones. Instability at upper yield point, the shapes of shear-band fronts, and mechanism of heat generation are also considered. It is shown that strain-rate acceleration plays a more important role than strain-rate itself in adiabatic instability.

  12. Advances in X-Band and S-Band Linear Accelerators for Security, NDT, and Other Applications

    CERN Document Server

    Mishin, Andrey V

    2005-01-01

    At AS&E High Energy Systems Division, we designed several new advanced high energy electron beam and X-ray sources. Our primary focus has always been in building the world's most portable commercial X-band accelerators. Today, our X-band systems frequently exceed performance of the similar S-band machines, while they are more portable compared to the latter. The new designs of the X-band accelerators in the most practical energy range from 1 MeV to 6 MeV have been tested delivering outstanding results. Seventy 6 MeV X-band linacs systems have been produced. The most compact linac for security is used by AS&E in a self-shielded, Shaped Energy™ cargo screening system. We pioneered using the X-band linear accelerators for CT, producing high quality images of oil pipes and wood logs. An X-band linear accelerator head on a robotic arm has been used for electron beam radiation curing of an odd-shaped graphite composite part. We developed the broad-range 4 MeV to over 10 MeV energy-regulated X-band ...

  13. 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.

  14. The Wulf bands of oxygen

    Science.gov (United States)

    Bernath, Peter; Carleer, Michel; Fally, Sophie; Jenouvrier, Alain; Vandaele, Ann Carine; Hermans, Christian; Mérienne, Marie-France; Colin, Reginald

    1998-11-01

    The Wulf bands of oxygen in the 240-290 nm spectral region are caused by collision-induced absorption of the Herzberg III ( A' 3Δu- X3Σ-g) system. These bands had been previously attributed to the oxygen dimer, (O 2) 2. Under atmospheric conditions the Wulf bands are thus the long-wavelength extension of the Herzberg continuum. Absorption of solar radiation by the Wulf bands may be an additional source of NO in the stratosphere.

  15. Photoionisation modelling of the broad line region

    Science.gov (United States)

    King, Anthea

    2016-08-01

    Two of the most fundamental questions regarding the broad line region (BLR) are "what is its structure?" and "how is it moving?" Baldwin et al. (1995) showed that by summing over an ensemble of clouds at differing densities and distances from the ionising source we can easily and naturally produce a spectrum similar to what is observed for AGN. This approach is called the `locally optimally emitting clouds' (LOC) model. This approach can also explain the well-observed stratification of emission lines in the BLR (e.g. Clavel et al. 1991, Peterson et al. 1991, Kollatschny et al. 2001) and `breathing' of BLR with changes in the continuum luminosity (Netzer & Mor 1990, Peterson et al. 2014) and is therefore a generally accepted model of the BLR. However, LOC predictions require some assumptions to be made about the distribution of the clouds within the BLR. By comparing photoionization predictions, for a distribution of cloud properties, with observed spectra we can infer something about the structure of the BLR and distribution of clouds. I use existing reverberation mapping data to constrain the structure of the BLR by observing how individual line strengths and ratios of different lines change in high and low luminosity states. I will present my initial constraints and discuss the challenges associated with the method.

  16. All-fiber broad-range self-sweeping Yb-doped fiber laser

    Science.gov (United States)

    Lobach, Ivan A.; Kablukov, Sergey A.; Podivilov, Evgeniy V.; Babin, Sergey A.

    2012-02-01

    The effect of broad-range self-sweeping in Yb-doped fiber laser has been demonstrated experimentally for the first time. The self-sweeping effect is observed in an all-fiber laser configuration with a double-clad Yb-doped fiber and a cavity formed by a broad-band fiber loop mirror and Fresnel reflection from one cleaved end. The sweep range is limited by the width of the broad-band reflector and reaches up to 16nm. It is found that the self-sweeping effect is related to selfpulsations. So the sweep rate is increased with an increase in pump power and is decreased with increasing cavity length. RF and optical spectra (linewidth is measured to be not more than 100 MHz) show that during the evolution of a single pulse a small number of longitudinal modes take a part in lasing. Based on these results we propose a model describing dynamics of the laser frequency. The model is based on the spatial hole burning effect and the gain saturation in Yb laser transition, and takes into account self-pulsations of the laser. Theoretical estimation for pulse to pulse change of lasing frequency is in good agreement with experimental data.

  17. The upper critical field in two-band layered superconductors

    Institute of Scientific and Technical Information of China (English)

    Liu Min-Xia; Gan Zi-Zhao

    2007-01-01

    The upper critical field of clean MgB2 is investigated using the two-band layered Ginzburg-Landau (GL) theory.The calculated results are fitted to the experimental data of clean MgB2 crystal very well in a broad temperature range.Based on the GL theory for clean superconductors,a phenomenOlogical theory for dirty superconductor is proposed.Selecting appropriate parameters,two-band layered GL theory is successfully applied to the crystal of Mg(B1-xCx)2 and the neutron irradiation samples of MgB2.

  18. AN EFFICIENT IMPLEMENTATION ARCHITECTURE FOR WIDE-BAND DIGITAL DOWNCONVERSION

    Institute of Scientific and Technical Information of China (English)

    Gao Zhicheng; Xiao Xianci

    2001-01-01

    The wide-band digital receiving systems require digital downconversion(DDC) with high data rate and short tuning time in order to intercept the narrow-band signals within broad tuning bandwidth. But these requirements can not be met by the commercial DDC. In this paper an efficient implementation architecture is presented. It combines the flexibility of DFT tuning with the efficiency of the polyphase filter bank decomposition. By first decimating the data prior to filtering and mixing, this architecture gives a better solution to the mismatch between the lower hardware speed and high data rate. The computer simulations show the feasibility of this processing architecture.

  19. Wide-Band Multi-spectral Space for Color Representation

    Institute of Scientific and Technical Information of China (English)

    KONG Lingwang; ZHU Yuanhong; Kurt Muenger; ZHANG Xuliang

    2003-01-01

    This paper develops a wide-band multi-spectral space for color representation with Aitken PCA algorithm. This novel mathematical space using the broad-band spectra matching method aims at improving the accuracy of color representation as well as reducing costs for processing and storing multi-spectral images. The results show that the space can present our experimental original spectral spaces (i. e. Munsell color matt and DIN-6164 color chips) with high efficiency, and that the spanning space with three eigenvectors can present the original space at more than 98%CSCR, and when 5 eigenvectors are used it can cover almost the whole original spaces.

  20. Validation, automatic generation and use of broad phonetic transcriptions

    NARCIS (Netherlands)

    Bael, Cristophe Patrick Jan Van

    2007-01-01

    Broad phonetic transcriptions represent the pronunciation of words as strings of characters from specifically designed symbol sets. In everyday life, broad phonetic transcriptions are often used as aids to pronounce (foreign) words. In addition, broad phonetic transcriptions are often used for lingu

  1. Broad spectrum anthelmintic potential of Cassia plants

    Institute of Scientific and Technical Information of China (English)

    Suman Kundu; Saptarshi Roy; Larisha Mawkhleing Lyndem

    2014-01-01

    Objective: To study the in vitro anthelmintic efficacy of Cassia alata (C. alata), Cassia(C. angustifolia) and Cassia occidentalis (C. occidentalis). angustifolia Methods: Crude ethanol extract from leaves of the three plants were prepared in rotary evaporator and different concentrations (10, 20 and 40 mg/mL) of leaf extracts were used for treatment on different representatives of helminthes (Heterakis gallinarum, Raillietina tetragona and Catatropis sp.) from domestic fowl (Gallus gallus domesticus). Loss of motility and death were monitored frequently.Results: C. alata showed early paralysis in all worms treated followed by C. angustifolia. C. occidentalis in combination with C. alata together caused early paralysis in all treated worms than the combination of C. alata with C. angustfolia. While Heterakis gallinarum in control survived for (81.33±2.07) h, treated worms lost their motility at (5.71±0.10) h, (6.60±0.86) h and (13.95±0.43) h with C. angustifolia, C. alata and C. occidentalis respectively at a concentration of 40 mg/mL which showed better efficacy than albendazole. Catatropis sp. survival period was (26.49±1.38) h in control, but with plant treatment, it lost its motility in just (0.57±0.08) h, (1.00±0.12) h and (1.47±0.40) h at 40 mg/mL concentration of C. alata, C. angustifolia and C. occidentalis respectively.Raillietina tetragona on the other hand became paralysed at (1.68±0.27) h, (2.95±0.29) h and (4.13±0.31) h with above concentrations treated with three plants respectively, however in control it survived up to (81.93±4.71) h.Conclusions:This present study indicated broad spectrum vermifugal activity of all plants tested.

  2. Arctic Change Information for a Broad Audience

    Science.gov (United States)

    Soreide, N. N.; Overland, J. E.; Calder, J.

    2002-12-01

    Demonstrable environmental changes have occurred in the Arctic over the past three decades. NOAA's Arctic Theme Page is a rich resource web site focused on high latitude studies and the Arctic, with links to widely distributed data and information focused on the Arctic. Included is a collection of essays on relevant topics by experts in Arctic research. The website has proven useful to a wide audience, including scientists, students, teachers, decision makers and the general public, as indicated through recognition by USA Today, Science magazine, etc. (http://www.arctic.noaa.gov) Working jointly with NSF and the University of Washington's Polar Science Center as part of the Study of Environmental Arctic Change (SEARCH) program, NOAA has developed a website for access to pan-Arctic time series spanning diverse data types including climate indices, atmospheric, oceanic, sea ice, terrestrial, biological and fisheries. Modest analysis functions and more detailed analysis results are provided. (http://www.unaami.noaa.gov/). This paper will describe development of an Artic Change Detection status website to provide a direct and comprehensive view of previous and ongoing change in the Arctic for a broad climate community. For example, composite metrics are developed using principal component analysis based on 86 multivariate pan-Arctic time series for seven data types. Two of these metrics can be interpreted as a regime change/trend component and an interdecadal component. Changes can also be visually observed through tracking of 28 separate biophysical indicators. Results will be presented in the form of a web site with relevant, easily understood, value-added knowledge backed by peer review from Arctic scientists and scientific journals.

  3. Evidence for AGN Feedback in the Broad Absorption Lines and Reddening of Mrk 231

    CERN Document Server

    Leighly, Karen M; Baron, Eddie; Lucy, Adrian B; Dietrich, Matthias; Gallagher, Sarah C

    2014-01-01

    We present the first J-band spectrum of Mrk 231, which reveals a large \\ion{He}{1}*$\\lambda 10830$ broad absorption line with a profile similar to that of the well-known \\ion{Na}{1} broad absorption line. Combining this spectrum with optical and UV spectra from the literature, we show that the unusual reddening noted by \\citet{veilleux13} is explained by a reddening curve like those previously used to explain low values of total-to-selective extinction in SNe Ia. The nuclear starburst may be the origin and location of the dust. Spatially-resolved emission in the broad absorption line trough suggests nearly full coverage of the continuum emission region. The broad absorption lines reveal higher velocities in the \\ion{He}{1}* lines (produced in the quasar-photoionized \\ion{H}{2} region) compared with the \\ion{Na}{1} and \\ion{Ca}{2} lines (produced in the corresponding partially-ionized zone). {\\it Cloudy} simulations show that a density increase is required between the \\ion{H}{2} and partially-ionized zones to ...

  4. Fast outflows in broad absorption line quasars and their connection with CSS/GPS sources

    CERN Document Server

    Bruni, G; Montenegro-Montes, F M; Brienza, M; González-Serrano, J I

    2015-01-01

    Broad absorption line quasars are among the objects presenting the fastest outflows. The launching mechanism itself is not completely understood. Models in which they could be launched from the accretion disk, and then curved and accelerated by the effect of the radiation pressure, have been presented. We conducted an extensive observational campaign, from radio to optical band, to collect information about their nature and test the models present in the literature, the main dichotomy being between a young scenario and an orientation one. We found a variety of possible orientations, morphologies, and radio ages, not converging to a particular explanation for the BAL phenomenon. From our latest observations in the m- and mm-band, we obtained an indication of a lower dust abundance with respect to normal quasars, thus suggesting a possible feedback process on the host galaxy. Also, in the low-frequency regime we confirmed the presence of CSS components, sometime in conjunction with a GPS one already detected at...

  5. Broad Frequency LTCC Vertical Interconnect Transition for Multichip Modules and System on Package Applications

    Science.gov (United States)

    Decrossas, Emmanuel; Glover, Michael D.; Porter, Kaoru; Cannon, Tom; Mantooth, H. Alan; Hamilton, M. C.

    2013-01-01

    Various stripline structures and flip chip interconnect designs for high-speed digital communication systems implemented in low temperature co-fired ceramic (LTCC) substrates are studied in this paper. Specifically, two different transition designs from edge launch 2.4 millimeter connectors to stripline transmission lines embedded in LTCC are discussed. After characterizing the DuPont (sup trademark) 9K7 green tape, different designs are proposed to improve signal integrity for high-speed digital data. The full-wave simulations and experimental data validate the presented designs over a broad frequency band from Direct Current to 50 gigahertz and beyond.

  6. The Tully-Fisher Relation and Its Residuals for a Broadly Selected Sample of Galaxies

    CERN Document Server

    Pizagno, J; Weinberg, D H; Rix, H W; Pogge, R W; Grebel, E K; Harbeck, D; Blanton, M; Brinkmann, J; Gunn, J E; Pizagno, James; Prada, Francisco; Weinberg, David H.; Rix, Hans-Walter; Pogge, Richard W.; Grebel, Eva K.; Harbeck, Daniel; Blanton, Michael; Gunn, James E.

    2006-01-01

    We measure the relation between galaxy luminosity and disk circular velocity (the Tully-Fisher [TF] relation), in the g, r, i, and z-bands, for a broadly selected sample of galaxies from the Sloan Digital Sky Survey, with the goal of providing well defined observational constraints for theoretical models of galaxy formation. The input sample of 234 galaxies has a roughly flat distribution of absolute magnitudes in the range -18.5 > Mr > -22, and our only morphological selection is an axis-ratio cut b/a < 0.6 to allow accurate inclination corrections. Long-slit spectroscopy yields usable H-alpha rotation curves for 170 galaxies. Observational errors, including distance errors due to peculiar velocities, are small compared to the intrinsic scatter of the TF relation. The slope of the forward TF relation steepens from -5.4 +/- 0.2 mag/log(km/s) in the g-band to -6.4 +/- 0.2 mag/log(km/s) in the z-band. The intrinsic scatter is approximately 0.4 mag in all bands. The scatter is not dominated by rare outliers o...

  7. Theoretical Simulation for Identical Bands

    Institute of Scientific and Technical Information of China (English)

    CHEN Yong-Jing; CHEN Yong-Shou; GAO Zao-Chun

    2004-01-01

    @@ The frequency of occurrence of identical bands is studied by analysing a large number of rotational bands calculated with the reflection asymmetric shell model, and the statistical properties of identical bands indicated in all the experimental observations are reproduced within the mean field approximation and beyond mean field treatment, such as angular momentum projection. The distributions of the calculated J(2), Eγ and the fractional change of J(2) are discussed.

  8. Cluster banding heat source model

    Institute of Scientific and Technical Information of China (English)

    Zhang Liguo; Ji Shude; Yang Jianguo; Fang Hongyuan; Li Yafan

    2006-01-01

    Concept of cluster banding heat source model is put forward for the problem of overmany increment steps in the process of numerical simulation of large welding structures, and expression of cluster banding heat source model is deduced based on energy conservation law.Because the expression of cluster banding heat source model deduced is suitable for random weld width, quantitative analysis of welding stress field for large welding structures which have regular welds can be made quickly.

  9. Band calculation of lonsdaleite Ge

    Science.gov (United States)

    Chen, Pin-Shiang; Fan, Sheng-Ting; Lan, Huang-Siang; Liu, Chee Wee

    2017-01-01

    The band structure of Ge in the lonsdaleite phase is calculated using first principles. Lonsdaleite Ge has a direct band gap at the Γ point. For the conduction band, the Γ valley is anisotropic with the low transverse effective mass on the hexagonal plane and the large longitudinal effective mass along the c axis. For the valence band, both heavy-hole and light-hole effective masses are anisotropic at the Γ point. The in-plane electron effective mass also becomes anisotropic under uniaxial tensile strain. The strain response of the heavy-hole mass is opposite to the light hole.

  10. Scarless platysmaplasty for platysmal bands

    Directory of Open Access Journals (Sweden)

    Shiffman Melvin

    2004-01-01

    Full Text Available Transection of plastysmal bands has required a surgical approach that leaves scars and limits patient activities for a period of time. The author has developed a simple method to transect the platysmal bands under local anesthesia without resorting to skin incisions. The transection is performed with the use of a Vicryl ® suture that is inserted through the skin, around the platysmal band, and then out through the original entry point. A back and forth motion of the suture cuts through the band.

  11. Iliotibial band Z-lengthening.

    Science.gov (United States)

    Richards, David P; Alan Barber, F; Troop, Randal L

    2003-03-01

    Iliotibial band friction syndrome (ITBFS) is a common overuse injury reported to afflict 1.6% to 12% of runners. It results from an inflammatory response secondary to excessive friction that occurs between the lateral femoral epicondyle and the iliotibial band. Initial treatments include rest, anti-inflammatory medication, modalities (ice or heat), stretching, physical therapy, and possibly a cortisone injection. In recalcitrant cases of ITBFS, surgery has been advocated. This report describes a surgical technique of Z-lengthening of the iliotibial band in patients presenting with lateral knee pain localized to the iliotibial band at the lateral femoral epicondyle and Gerdy's tubercle who failed all nonoperative efforts.

  12. Garage Band or GarageBand[R]? Remixing Musical Futures

    Science.gov (United States)

    Vakeva, Lauri

    2010-01-01

    In this paper, I suggest that it is perhaps time to consider the pedagogy of popular music in more extensive terms than conventional rock band practices have to offer. One direction in which this might lead is the expansion of the informal pedagogy based on a "garage band" model to encompass various modes of digital artistry wherever this artistry…

  13. 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.

  14. On the Operational Meaning of Broad-Spectrum Philosophy Methodology

    Directory of Open Access Journals (Sweden)

    Miao Yi

    2012-06-01

    Full Text Available This study analyze the Broad-spectrum Philosophy Methodology on the operational meaning, and discusses three relatively primary methods of Broad-spectrum Philosophy Methodologies. The methodology of Broad-spectrum philosophy cannot pursuit of accuracy of numerical sense, but it pursuits of the exact nature of the research questions, the accuracy of the sense of set theory and sums up the experience which we solve problems in real life and make it up to the generalized quantization and procedural level and thus the methodology of Broad-spectrum philosophy has a general guide and it is a broad operations research. We gets the results that along with deep exploration and development of Broad-spectrum Philosophy Methodology, its function as generalized operation research can be more powerful.

  15. Cross-reactive broadly neutralizing antibodies: timing is everything

    OpenAIRE

    Euler, Zelda; Schuitemaker, Hanneke

    2012-01-01

    The recent surge of research into new broadly neutralizing antibodies in HIV-1 infection has recharged the field of HIV-1 vaccinology. In this review we discuss the currently known broadly neutralizing antibodies and focus on factors that may shape these antibodies in natural infection. We further discuss the role of these antibodies in the clinical course of the infection and consider immunological obstacles in inducing broadly neutralizing antibodies with a vaccine.

  16. Cross-reactive broadly neutralizing antibodies: timing is everything.

    Science.gov (United States)

    Euler, Zelda; Schuitemaker, Hanneke

    2012-01-01

    The recent surge of research into new broadly neutralizing antibodies in HIV-1 infection has recharged the field of HIV-1 vaccinology. In this review we discuss the currently known broadly neutralizing antibodies and focus on factors that may shape these antibodies in natural infection. We further discuss the role of these antibodies in the clinical course of the infection and consider immunological obstacles in inducing broadly neutralizing antibodies with a vaccine.

  17. Long Lake banding project, 1965

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This report summarizes the results of a banding project on Long Lake in 1965. The dates at the banding site were July 27th through August 8th. As in the past, the...

  18. Inclination of Broad Line Region in Narrow Line and Broad Line Seyfert 1 Galaxies

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The sizes of the Broad Line Region (BLR) of some Seyfert 1 galax-ies and nearby quasars can be determined by the reverberation mapping method.Combining with the observed FWHM of Hβ emission line and assuming that themotion of BLR clouds is virialized, the black hole masses of these objects have beenestimated. However, this method strongly depends on the poorly-understood geom-etry and inclination of the BLR. On the other hand, a tight correlation between theblack hole mass and the bulge velocity dispersion was recently found for both activeand nearby inactive galaxies. This may provide another method, independent of theBLR geometry, for estimating the black hole mass. Using this method for estimatingthe black hole mass and combining with the measured BLR size and FWHM of Hβemission line, we derived the BLR inclination angles for 20 Seyfert I galaxies underthe assumption that the BLR is disk-like. The derived inclination angles agree wellwith those derived previously by fitting the UV continuum and Hβ emission lineprofiles. Adopting a relation between the FWHMs of [OⅢ]λ5007 forbidden line andthe stellar velocity dispersion, we also estimated the BLR inclinations for 50 nar-row line Seyfert 1 galaxies (NLSls). We found that the inclinations of broad LineSeyfert 1 galaxies (BLS1s) are systematically greater than those of NLS1s, whichseldom exceed 30. This may be an important factor that leads to the differencesbetween NLS1s and BLS1s if the BLR of NLS1s is really disk-like.

  19. Theoretical study on the two-band degenerate-gaps superconductors: Application to SrPt3P

    Science.gov (United States)

    Huang, Hai; Hou, Li-Chao; Zhao, Bin-Peng

    2016-09-01

    We study the magnetic properties of two-band degenerate-gaps superconductors with two-band isotropic Ginzburg-Landau theory. The exact solutions of upper critical field and London penetration depth are obtained, and the calculations reproduce the experimental data of the recently observed superconducting crystal SrPt3P in a broad temperature range. It directly underlies that SrPt3P is a multi-band superconductor with equal gaps in two Fermi surface sheets.

  20. Signature of a three-dimensional photonic band gap observed on silicon inverse woodpile photonic crystals

    CERN Document Server

    Huisman, Simon R; Woldering, Léon A; Leistikow, Merel D; Mosk, Allard P; Vos, Willem L

    2010-01-01

    We have studied the reflectivity of CMOS-compatible three-dimensional silicon inverse woodpile photonic crystals at near-infrared frequencies. Polarization-resolved reflectivity spectra were obtained from two orthogonal crystal surfaces corresponding to 1.88 pi sr solid angle. The spectra reveal broad peaks with high reflectivity up to 67 % that are independent of the spatial position on the crystals. The spectrally overlapping reflectivity peaks for all directions and polarizations form the signature of a broad photonic band gap with a relative bandwidth up to 16 %. This signature is supported with stopgaps in plane wave bandstructure calculations and with the frequency region of the expected band gap.

  1. Assessing Eli Broad's Assault on Public School System Leadership

    Science.gov (United States)

    English, Fenwick W.; Crowder, Zan

    2012-01-01

    Eli Broad's approach to reforming urban public education does not recognize his own self-interest in promoting changes within such educational systems, a classic problem of misrecognition. The Broad agenda is an assault on the notion of the mission of public education as a service instead of a for-profit enterprise concerned with making money for…

  2. Social Cognition, Social Skill, and the Broad Autism Phenotype

    Science.gov (United States)

    Sasson, Noah J.; Nowlin, Rachel B.; Pinkham, Amy E.

    2013-01-01

    Social-cognitive deficits differentiate parents with the "broad autism phenotype" from non-broad autism phenotype parents more robustly than other neuropsychological features of autism, suggesting that this domain may be particularly informative for identifying genetic and brain processes associated with the phenotype. The current study…

  3. Broadly protective influenza vaccines: Redirecting the antibody response through adjuvation

    NARCIS (Netherlands)

    Cox, F.

    2016-01-01

    Influenza virus infections are responsible for significant morbidity worldwide and current vaccines have limited coverage, therefore it remains a high priority to develop broadly protective vaccines. With the discovery of broadly neutralizing antibodies (bnAbs) against influenza these vaccines becam

  4. Boot Camp for Education CEOs: The Broad Foundation Superintendents Academy

    Science.gov (United States)

    Jehlen, Alain

    2012-01-01

    The Broad Foundation Superintendents Academy is the most prominent and most controversial training institute for school chiefs. The Academy is the flagship program of the Eli and Edythe Broad Foundation, the smallest of a triumvirate of corporate foundations that are at the heart of the billionaire campaign to remake public education in the image…

  5. The broad-line region and dust torus size of the Seyfert 1 galaxy PGC50427

    CERN Document Server

    Nuñez, F Pozo; Westhues, C; Haas, M; Chini, R; Steenbrugge, K; Domínguez, A Barr; Kaderhandt, L; Hackstein, M; Kollatschny, W; Zetzl, M; Hodapp, Klaus W; Murphy, M

    2015-01-01

    We present the results of a three years monitoring campaigns of the $z = 0.024$ type-1 active galactic nucleus (AGN) PGC50427. Through the use of Photometric Reverberation Mapping with broad and narrow band filters, we determine the size of the broad-line emitting region by measuring the time delay between the variability of the continuum and the H$\\alpha$ emission line. The H$\\alpha$ emission line responds to blue continuum variations with an average rest frame lag of $19.0 \\pm 1.23$ days. Using single epoch spectroscopy we determined a broad-line H$\\alpha$ velocity width of 1020 km s$^{-1}$ and in combination with the rest frame lag and adoption a geometric scaling factor $f = 5.5$, we calculate a black hole mass of $M_{BH} \\sim 17 \\times 10^{6} M_{\\odot}$. Using the flux variation gradient method, we separate the host galaxy contribution from that of the AGN to calculate the rest frame 5100\\AA~ luminosity at the time of our monitoring campaign. The rest frame lag and the host-subtracted luminosity permit u...

  6. SN 2009bb: a Peculiar Broad-Lined Type Ic Supernova

    CERN Document Server

    Pignata, Giuliano; Soderberg, Alicia; Mazzali, Paolo; Phillips, M M; Morrell, Nidia; Anderson, J P; Boldt, Luis; Campillay, Abdo; Contreras, Carlos; Folatelli, Gastón; Förster, Francisco; González, Sergio; Hamuy, Mario; Krzeminski, Wojtek; Maza, José; Roth, Miguel; Levesque, Francisco Salgado Emily M; Rest, Armin; Crain, J Adam; Foster, Andrew C; Haislip, Joshua B; Ivarsen, Kevin M; LaCluyze, Aaron P; Nysewander, Melissa C; Reichart, Daniel E

    2010-01-01

    Ultraviolet, optical, and near-infrared photometry and optical spectroscopy of the broad-lined Type Ic supernova (SN) 2009bb are presented, following the flux evolution from -10 to +285 days past B-band maximum. Thanks to the very early discovery, it is possible to place tight constraints on the SN explosion epoch. The expansion velocities measured from near maximum spectra are found to be only slightly smaller than those measured from spectra of the prototype broad-lined SN 1998bw associated with GRB 980425. Fitting an analytical model to the pseudo-bolometric light curve of SN 2009bb suggests that 4.1+-1.9 Msun of material was ejected with 0.22 +-0.06 Msun of it being 56Ni. The resulting kinetic energy is 1.8+-0.7x10^52 erg. This, together with an absolute peak magnitude of MB=-18.36+-0.44, places SN 2009bb on the energetic and luminous end of the broad-lined Type Ic (SN Ic) sequence. Detection of helium in the early time optical spectra accompanied with strong radio emission, and high metallicity of its en...

  7. Microstrip microwave band gap structures

    Indian Academy of Sciences (India)

    V Subramanian

    2008-04-01

    Microwave band gap structures exhibit certain stop band characteristics based on the periodicity, impedance contrast and effective refractive index contrast. These structures though formed in one-, two- and three-dimensional periodicity, are huge in size. In this paper, microstrip-based microwave band gap structures are formed by removing the substrate material in a periodic manner. This paper also demonstrates that these structures can serve as a non-destructive characterization tool for materials, a duplexor and frequency selective coupler. The paper presents both experimental results and theoretical simulation based on a commercially available finite element methodology for comparison.

  8. Power and Efficiency Optimized in Traveling-Wave Tubes Over a Broad Frequency Bandwidth

    Science.gov (United States)

    Wilson, Jeffrey D.

    2001-01-01

    A traveling-wave tube (TWT) is an electron beam device that is used to amplify electromagnetic communication waves at radio and microwave frequencies. TWT's are critical components in deep space probes, communication satellites, and high-power radar systems. Power conversion efficiency is of paramount importance for TWT's employed in deep space probes and communication satellites. A previous effort was very successful in increasing efficiency and power at a single frequency (ref. 1). Such an algorithm is sufficient for narrow bandwidth designs, but for optimal designs in applications that require high radiofrequency power over a wide bandwidth, such as high-density communications or high-resolution radar, the variation of the circuit response with respect to frequency must be considered. This work at the NASA Glenn Research Center is the first to develop techniques for optimizing TWT efficiency and output power over a broad frequency bandwidth (ref. 2). The techniques are based on simulated annealing, which has the advantage over conventional optimization techniques in that it enables the best possible solution to be obtained (ref. 3). Two new broadband simulated annealing algorithms were developed that optimize (1) minimum saturated power efficiency over a frequency bandwidth and (2) simultaneous bandwidth and minimum power efficiency over the frequency band with constant input power. The algorithms were incorporated into the NASA coupled-cavity TWT computer model (ref. 4) and used to design optimal phase velocity tapers using the 59- to 64-GHz Hughes 961HA coupled-cavity TWT as a baseline model. In comparison to the baseline design, the computational results of the first broad-band design algorithm show an improvement of 73.9 percent in minimum saturated efficiency (see the top graph). The second broadband design algorithm (see the bottom graph) improves minimum radiofrequency efficiency with constant input power drive by a factor of 2.7 at the high band edge (64

  9. Band head spin assignment of superdeformed bands in 86Zr

    Science.gov (United States)

    Dadwal, Anshul; Mittal, H. M.

    2016-11-01

    Two parameter expressions for rotational spectra viz. variable moment of inertia (VMI), ab formula and three parameter Harris ω 2 expansion are used to assign the band head spins (I 0) of four rotational superdeformed bands in 86Zr. The least-squares fitting method is employed to obtain the band head spins of these four bands in the A ∼ 80 mass region. Model parameters are extracted by fitting of intraband γ-ray energies, so as to obtain a minimum root-mean-square (rms) deviation between the calculated and the observed transition energies. The calculated transition energies are found to depend sensitively on the assigned spins. Whenever an accurate band head spin is assigned, the calculated transition energies are in agreement with the experimental transition energies. The dynamic moment of inertia is also extracted and its variation with rotational frequency is investigated. Since a better agreement of band head spin with experimental results is found using the VMI model, it is a more powerful tool than the ab formula and Harris ω 2 expansion.

  10. Broad-Band Photocurrent Enhancement in MoS2 Layers Directly Grown on Light-Trapping Si Nanocone Arrays.

    Science.gov (United States)

    Cho, Yunae; Cho, Byungjin; Kim, Yonghun; Lee, Jihye; Kim, Eunah; Nguyen, Trang Thi Thu; Lee, Ju Hyun; Yoon, Seokhyun; Kim, Dong-Ho; Choi, Jun-Hyuk; Kim, Dong-Wook

    2017-02-22

    There has been growing research interest in realizing optoelectronic devices based on the two-dimensional atomically thin semiconductor MoS2 owing to its distinct physical properties that set it apart from conventional semiconductors. However, there is little optical absorption in these extremely thin MoS2 layers, which presents an obstacle toward applying them for use in high-efficiency light-absorbing devices. We synthesized trilayers of MoS2 directly on SiO2/Si nanocone (NC) arrays using chemical vapor deposition and investigated their photodetection characteristics. The photoresponsivity of the MoS2/NC structure was much higher than that of the flat counterpart across the whole visible wavelength range (for example, it was almost an order of magnitude higher at λ = 532 nm). Strongly concentrated light near the surface that originated from a Fabry-Perot interference in the SiO2 thin layers and a Mie-like resonance caused by the Si NCs boosted the optical absorption in MoS2. Our work demonstrates that MoS2/NC structures could provide a useful means to realize high-performance optoelectronic devices.

  11. 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...

  12. Low Temperature Broad Band Dielectric Spectroscopy of Multiferroic Bi6Fe2Ti3O18 Ceramics

    Directory of Open Access Journals (Sweden)

    Lisińska-Czekaj A.

    2016-09-01

    Full Text Available In the present research the tool of broadband dielectric spectroscopy was utilized to characterize dielectric behavior of Bi6Fe2Ti3O18 (BFTO Aurivillius-type multiferroic ceramics. Dielectric response of BFTO ceramics was studied in the frequency domain (Δν=0.1Hz – 10MHz within the temperature range ΔT=-100°C – 200°C. The Kramers-Kronig data validation test was employed to validate the impedance data measurements and it was found that the measured impedance data exhibited good quality justifying further analysis. The residuals were found to be less than 1%, whereas the “chi-square” parameter was within the range χ2~10−7−10−5. Experimental data were analyzed using the circle fit of simple impedance arc plotted in the complex Z”-Z’ plane (Nyquist plot. The total ac conductivity of the grain boundaries was thus revealed and the activation energy of ac conductivity for the grain boundaries was calculated. It was found that activation energy of ac conductivity of grain boundaries changes from EA=0.20eV to EA=0.55eV while temperature rises from T=-100°C up to T=200°C. On the base of maxima of the impedance semicircles (ωmτm=1 the relaxation phenomena were characterized in terms of the temperature dependence of relaxation times and relevant activation energy was calculated (EA=0.55eV.

  13. Broad-band BeppoSAX observation of the low-mass X-ray binary X1822-371

    CERN Document Server

    Parmar, A N; Del Sordo, S; Segreto, A; Santangelo, A; Dal Fiume, D; Orlandini, M

    2000-01-01

    Results of a 1997 September 9-10 BeppoSAX observation of the 5.57 hr low-mass X-ray binary (LMXRB) X1822-371 are presented. The 0.3-40 keV spectrum is unusually complex and cannot be fit by any of the standard models applied to other LMXRB. At least two components are required. One component has a shape consistent with that expected from the Comptonization of an input soft (Wein) spectrum while the other, contributing ~40% of the 1-10 keV flux, is consistent with being a blackbody. In addition, there is a ``dip'' in the spectrum which can be modeled by a 1.33 +0.05 -0.11 keV absorption edge with an optical depth, tau, of 0.28 +/- 0.06. If the same model is fit to ASCA Solid-State Imaging Spectrometer spectra obtained in 1993 and 1996, then reasonable fits are also obtained, with a similar absorption feature required. The nature of this feature is highly uncertain; its energy corresponds to the K-edges of highly ionized Ne x and neutral Mg, or to an L-edge of moderately ionized Fe. Surprisingly, no strong (tau...

  14. Broad band shock associated noise predictions in axisymmetric and asymmetric jets using an improved turbulence scale model

    Science.gov (United States)

    Kalyan, Anuroopa; Karabasov, Sergey A.

    2017-04-01

    Supersonic jets that are subject to off-design operating conditions are marked by three distinct regions in their far-field spectra: mixing noise, screech and Broadband Shock Associated Noise (BBSAN). BBSAN is conspicuous by the prominent multiple peaks. The Morris and Miller BBSAN model that is based on an acoustic analogy, offering a straightforward implementation for RANS, forms the foundation of the present work. The analogy model robustly captures the peak frequency noise, that occurs near Strouhal number of about 1, based on the nozzle exit diameter but leads to major sound under prediction for higher frequencies. In the jet mixing noise literature, it has been shown that an inclusion of frequency dependence into the characteristic length and temporal scales of the effective noise sources improves the far-field noise predictions. In the present paper, several modifications of the original Morris and Miller model are considered that incorporate the frequency dependent scales as recommended in the jet mixing noise literature. In addition to these, a new mixed scale model is proposed that incorporates a correlation scale that depends both on the mean-flow velocity gradient and the standard mixing noise-type scaling based on the dissipation of turbulent kinetic energy. In comparison with the original Morris and Miller model, the mixed scale model shows considerable improvements in the noise predictions for the benchmark axisymmetric convergent-divergent and convergent jets. Further to this validation, the new model has been applied for improved predictions for elliptic jets of various eccentricity. It has been shown that, for the same thrust conditions, the elliptical nozzles lead to noise reduction at the source in comparison with the baseline axisymmetric jets.

  15. A new strip line broad-band measurement evaluation for determining the complex permeability of thin ferromagnetic films

    Energy Technology Data Exchange (ETDEWEB)

    Bekker, V.; Seemann, K. E-mail: klaus.seemann@imf.fzk.de; Leiste, H

    2004-04-01

    In the present paper, a new method for determining the frequency dependent complex permeability of thin magnetic films, designed for measurements up to 5 GHz, is presented. The measurement technique described here was carried out by a one-port permeameter, which is based on a short-circuited strip line. The complex permeability was deduced by a new analytical approach from the measured reflection coefficient of a strip line (S{sub 11}) with and without a ferromagnetic film material inside. An adaptive error correction was applied in the measurement procedure. The spectral permeability of thin FeCoAlN films with an in-plane uniaxial anisotropy of {mu}{sub 0}{sup *}H{sub a}=3.2 mT induced by annealing at CMOS temperatures in a static magnetic field was investigated. The measurements were compared with a theoretical model taking the Landau-Lifshitz and eddy current theories into account. A resonant frequency of about 1.6 GHz was observed.

  16. Broad-band X-ray spectral evolution of GX 339-4 during a state transition

    CERN Document Server

    Del Santo, M; Homan, J; Bazzano, A; Casella, P; Fender, R P; Gallo, E; Gehrels, N; Lewin, W H G; Méndez, M; Van der Klis, M

    2008-01-01

    We report on X-ray and soft gamma-ray observations of the black-hole candidate GX 339-4 during its 2007 outburst, performed with the RXTE and INTEGRAL satellites. The hardness-intensity diagram of all RXTE/PCA data combined shows a q-shaped track similar to that observed in previous outbursts.The evolution in the diagram suggested that a transition from hard-intermediate state to soft-intermediate state occurred, simultaneously with INTEGRAL observations performed in March. The transition is confirmed by the timing analysis presented in this work, which reveals that a weak type-A quasi-periodic oscillation (QPO) replaces a strong type-C QPO. At the same time, spectral analysis shows that the flux of the high-energy component shows a significant decrease in its flux. However, we observe a delay (roughly one day) between variations of the spectral parameters of the high-energy component and changes in the flux and timing properties. The changes in the high-energy component can be explained either in terms the h...

  17. Broad-band robustly single-mode hollow-core PCF by resonant filtering of higher order modes

    CERN Document Server

    Günendi, Mehmet C; Frosz, Michael H; Russell, Philip St J

    2015-01-01

    We propose and theoretically analyse a novel hollow-core photonic crystal fibre (PCF) that is engineered so as to strongly suppress higher order modes, i.e., to provide robust LP$_{01}$ single-mode guidance in all the wavelength ranges where the fibre guides with low loss. Encircling the core is a single ring of non-touching glass elements whose modes are tailored to ensure resonant phase-matched coupling to higher-order core modes, causing them to leak at a very high rate into the supporting solid glass sheath. Using a model based on coupled capillary waveguides, as well as full vectorial finite element modelling, we show that this modal filtering effect depends on only one dimensionless geometrical parameter, akin to the well-known $d/{\\Lambda}$ parameter for endlessly single-mode solid-core PCF. The design is scalable up to large core sizes and is predicted to deliver LP$_{01}$ mode losses of some $10$s of dB/km in multiple transmission windows, the broadest of which spans more than an octave. At the same ...

  18. Cell-Based Sensor System Using L6 Cells for Broad Band Continuous Pollutant Monitoring in Aquatic Environments

    Directory of Open Access Journals (Sweden)

    Evamaria Stütz

    2012-03-01

    Full Text Available Pollution of drinking water sources represents a continuously emerging problem in global environmental protection. Novel techniques for real-time monitoring of water quality, capable of the detection of unanticipated toxic and bioactive substances, are urgently needed. In this study, the applicability of a cell-based sensor system using selected eukaryotic cell lines for the detection of aquatic pollutants is shown. Readout parameters of the cells were the acidification (metabolism, oxygen consumption (respiration and impedance (morphology of the cells. A variety of potential cytotoxic classes of substances (heavy metals, pharmaceuticals, neurotoxins, waste water was tested with monolayers of L6 cells (rat myoblasts. The cytotoxicity or cellular effects induced by inorganic ions (Ni2+ and Cu2+ can be detected with the metabolic parameters acidification and respiration down to 0.5 mg/L, whereas the detection limit for other substances like nicotine and acetaminophen are rather high, in the range of 0.1 mg/L and 100 mg/L. In a close to application model a real waste water sample shows detectable signals, indicating the existence of cytotoxic substances. The results support the paradigm change from single substance detection to the monitoring of overall toxicity.

  19. Ultra-Broad-Band LiNbO3 Electro-Optic Modulators with Novel Complex Electrode

    Institute of Scientific and Technical Information of China (English)

    ZHOU Weiqin; WU Boyu; PENG Jihu; GU Jinghua; HU Jinyang

    2000-01-01

    The characteristics of Z- cut LiNbO3 optical modulators with novel complex electrode are discussed by using the finite element method (FEM) and studied experimentally in this paper. The travelling wave electrode consists of upper and lower parts. It can easily realize phase velocity matching between microwave and optical wave and drastically reduce microwave electrode loss. An electrooptic modulator with larger than 100 GHz bandwidth and half wave voltage 6 V is designed, fabricated and measured. Vπ is 5.1 V and the attenuation coefficient a0 is 0.3 dB/(cm· GHz1/2 ). The experimental results show that the modulator has great potentiality for expanding bandwidth.

  20. A High-Sensitivity Broad-Band Seismic Sensor for Shallow Seismic Sounding of the Lunar Regolith

    Science.gov (United States)

    Pike, W. Thomas; Standley, Ian M.; Banerdt, W. Bruce

    2005-01-01

    The recently undertaken Space Exploration Initiative has prompted a renewed interest in techniques for characterizing the surface and shallow subsurface (0-10s of meters depth) of the Moon. There are several reasons for this: First, there is an intrinsic scientific interest in the subsurface structure. For example the stratigraphy, depth to bedrock, density/porosity, and block size distribution all have implications for the formation of, and geological processes affecting the surface, such as sequential crater ejecta deposition, impact gardening, and seismic settling. In some permanently shadowed craters there may be ice deposits just below the surface. Second, the geotechnical properties of the lunar surface layers are of keen interest to future mission planners. Regolith thickness, strength, density, grain size and compaction will affect construction of exploration infrastructure in terms of foundation strength and stability, ease of excavation, radiation shielding effectiveness, as well as raw material handling and processing techniques for resource extraction.

  1. Theoretical predictions for the effect of nebular emission on the broad band photometry of high-redshift galaxies

    CERN Document Server

    Wilkins, Stephen M; Caruana, Joseph; Croft, Rupert; Di Matteo, Tiziana; Khandai, Nishikanta; Feng, Yu; Bunker, Andrew; Elbert, Holly

    2013-01-01

    By combining optical and near-IR observations from the Hubble Space Telescope with NIR photometry from the Spitzer Space Telescope it is possible to measure the rest-frame UV-optical colours of galaxies at z=4-8. The UV-optical spectral energy distribution of star formation dominated galaxies is the result of several different factors. These include the joint distribution of stellar masses, ages, and metallicities, and the subsequent reprocessing by dust and gas in the ISM. Using a large cosmological hydrodynamical simulation we investigate the predicted spectral energy distributions of galaxies at high-redshift with a particular emphasis on assessing the potential contribution of nebular emission. We find that the average pure stellar UV-optical colour correlates with both luminosity and redshift such that galaxies at lower-redshift and higher-luminosity are typically redder. Assuming the escape fraction of ionising photons is close to zero, the effect of nebular emission is to redden the UV-optical 1500-V_w...

  2. Design and Analysis of Broad-Band Fixed-Tuned Submillimeter-Waveguide Multipliers using MMIC Style Circuit Topology

    Science.gov (United States)

    Bruston, J.; Kim, M.; Martin, S. C.; Mehdi, I.; Smith, R. P.; Siegel, P. H.

    1996-01-01

    The design and analysis of varactor diode doubler, quadrupler and cascaded doubler circuits for 320 and 640 GHz have been completed. A new approach has been employed to produce a tunerless waveguide mount with a very flexible, frequency scaleable, MMIC style multiplier circuit. The concept, design, predicted performance and measurements on some of the constituent mount elements are presented.

  3. GRB 110530A: Peculiar Broad Bump and Delayed Plateau in Early Optical Afterglows

    Science.gov (United States)

    Zhong, Shu-Qing; Xin, Li-Ping; Liang, En-Wei; Wei, Jian-Yan; Urata, Yuji; Huang, Kui-Yun; Qiu, Yu-Lei; Deng, Can-Min; Wang, Yuan-Zhu; Deng, Jin-Song

    2016-11-01

    We report our very early optical observations of GRB 110530A and investigate its jet properties together with its X-ray afterglow data. A peculiar broad onset bump followed by a plateau is observed in its early R band afterglow light curve. The optical data in the other bands and the X-ray data are well consistent with the temporal feature of the R band light curve. Our joint spectral fits of the optical and X-ray data show that they are in the same regime, with a photon index of ∼1.70. The optical and X-ray afterglow light curves are well fitted with the standard external shock model by considering a delayed energy injection component. Based on our modeling results, we find that the radiative efficiency of the gamma-ray burst jet is ∼ 1 % and the magnetization parameter of the afterglow jet is \\lt 0.04 with a derived extremely low {ε }B (the ratio of shock energy to the magnetic field) of (1.64+/- 0.25)× {10}-6. These results indicate that the jet may be matter dominated. A discussion on delayed energy injection from the accretion of the late fall-back material of its pre-supernova star is also presented.

  4. GRB 110530A: Peculiar Broad Bump and Delayed Plateau in Early Optical Afterglows

    CERN Document Server

    Zhong, Shu-Qing; Liang, En-Wei; Wei, Jian-Yan; Urata, Yuji; Huang, Kui-Yun; Qiu, Yu-Lei; Deng, Can-Min; Wang, Yuan-Zhu; Deng, Jin-Song

    2016-01-01

    We report our very early optical observations of GRB 110530A and investigate its jet properties together with its X-ray afterglow data. A peculiar broad onset bump followed by a plateau is observed in its early R band afterglow lightcurve. The optical data in the other bands and the X-ray data are well consistent with the temporal feature of the R band lightcurve. Our joint spectral fits of the optical and X-ray data show that they are in the same regime, with a photon index of $\\sim 1.70$. The optical and X-ray afterglow lightcurves are well fitted with the standard external shock model by considering a delayed energy injection component. Based on our modeling results, we find that the radiative efficiency of the GRB jet is $\\sim 1\\%$ and the magnetization parameter of the afterglow jet is $<0.04$ with the derived extremely low $\\epsilon_B$ (the fraction of shock energy to magnetic field) of $(1.64\\pm 0.25)\\times 10^{-6}$. These results indicate that the jet may be matter dominated. Discussion on delayed ...

  5. Ultra-broad bandwidth parametric amplification at degeneracy.

    Science.gov (United States)

    Limpert, J; Aguergaray, C; Montant, S; Manek-Hönninger, I; Petit, S; Descamps, D; Cormier, E; Salin, F

    2005-09-19

    We report on a novel approach of ultra-broad bandwidth parametric amplification around degeneracy. A bandwidth of up to 400 nm centered around 800 nm is amplified in a BBO crystal by using chirped pump pulses with a bandwitdth as broad as 10 nm. A supercontinuum signal is generated in a microstructured fiber, having to first order a quadratic chirp, which is necessary to ensure temporal overlap of the interacting waves over this broad bandwidth. Furthermore, we discuss the potential of this approach for an octave-spanning parametric amplification.

  6. Large Frequency Range of Photonic Band Gaps on Porous Silicon Heterostructures for Infrared Applications

    CERN Document Server

    Manzanares-Martinez, J; Archuleta-Garcia, R; Moctezuma-Enriquez, D

    2010-01-01

    In this work we show theoretically that it is possible to design a large band gap in the infrared range using a one-dimensional Photonic Crystal heterostructure made of porous silicon. Stacking together multiple photonic crystal substructures of the same contrast index, but of different lattice periods, it is possible to broad the narrow forbidden band gap that can be reached by the low contrast index of the porous silicon multilayers. The main idea in this work is that we can construct a Giant Photonic Band Gap -as large as desired- by combining a tandem of photonic crystals substructures by using a simple analytical rule to determine the period of each substructure.

  7. AGN Broad Line Regions Scale with Bolometric Luminosity

    CERN Document Server

    Trippe, Sascha

    2015-01-01

    The masses of supermassive black holes in active galactic nuclei (AGN) can be derived spectroscopically via virial mass estimators based on selected broad optical/ultraviolet emission lines. These estimates commonly use the line width as a proxy for the gas speed and the monochromatic continuum luminosity as a proxy for the radius of the broad line region. However, if the size of the broad line region scales with bolometric rather than monochromatic AGN luminosity, mass estimates based on different emission lines will show a systematic discrepancy which is a function of the color of the AGN continuum. This has actually been observed in mass estimates based on H-alpha / H-beta and C IV lines, indicating that AGN broad line regions indeed scale with bolometric luminosity. Given that this effect seems to have been overlooked as yet, currently used single-epoch mass estimates are likely to be biased.

  8. Broad Spectrum Sanitizing Wipes with Food Additives Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Microcide proposes to develop novel multipurpose non-toxic sanitizing wipes that are aqueous based, have shelf life of 3-5 years, have broad spectrum microbicidal...

  9. A CENSUS OF BROAD-LINE ACTIVE GALACTIC NUCLEI IN NEARBY GALAXIES: COEVAL STAR FORMATION AND RAPID BLACK HOLE GROWTH

    Energy Technology Data Exchange (ETDEWEB)

    Trump, Jonathan R.; Fang, Jerome J.; Faber, S. M.; Koo, David C.; Kocevski, Dale D. [University of California Observatories/Lick Observatory and Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Hsu, Alexander D. [The Harker School, 500 Saratoga Avenue, San Jose, CA 95129 (United States)

    2013-02-15

    We present the first quantified, statistical map of broad-line active galactic nucleus (AGN) frequency with host galaxy color and stellar mass in nearby (0.01 < z < 0.11) galaxies. Aperture photometry and z-band concentration measurements from the Sloan Digital Sky Survey are used to disentangle AGN and galaxy emission, resulting in estimates of uncontaminated galaxy rest-frame color, luminosity, and stellar mass. Broad-line AGNs are distributed throughout the blue cloud and green valley at a given stellar mass, and are much rarer in quiescent (red sequence) galaxies. This is in contrast to the published host galaxy properties of weaker narrow-line AGNs, indicating that broad-line AGNs occur during a different phase in galaxy evolution. More luminous broad-line AGNs have bluer host galaxies, even at fixed mass, suggesting that the same processes that fuel nuclear activity also efficiently form stars. The data favor processes that simultaneously fuel both star formation activity and rapid supermassive black hole accretion. If AGNs cause feedback on their host galaxies in the nearby universe, the evidence of galaxy-wide quenching must be delayed until after the broad-line AGN phase.

  10. Clues to Quasar Broad Line Region Geometry and Kinematics

    DEFF Research Database (Denmark)

    Vestergaard, Marianne; Wilkes, B. J.; Barthel, P. D.

    2000-01-01

    width to show significant inverse correlations with the fractional radio core-flux density, R, the radio axis inclination indicator. Highly inclined systems have broader line wings, consistent with a high-velocity field perpendicular to the radio axis. By contrast, the narrow line-core shows...... and with an accretion disk-wind emitting the broad lines. A spherical distribution of randomly orbiting broad-line clouds and a polar high-ionization outflow are ruled out....

  11. Identification and specificity of broadly neutralizing antibodies against HIV

    OpenAIRE

    McCoy, Laura E.; Burton, Dennis R.

    2017-01-01

    Summary Beginning in 2009, studies of the humoral responses of HIV‐positive individuals have led to the identification of scores, if not hundreds, of antibodies that are both broadly reactive and potently neutralizing. This development has provided renewed impetus toward an HIV vaccine and led directly to the development of novel immunogens. Advances in identification of donors with the most potent and broad anti‐HIV serum neutralizing responses were crucial in this effort. Equally, developme...

  12. Quasi-static stop band with flexural metamaterial having zero rotational stiffness

    Science.gov (United States)

    Oh, Joo Hwan; Assouar, Badreddine

    2016-01-01

    Metamaterials realizing stop bands have attracted much attentions recently since they can break-through the well-known mass law. However, achieving the stop band at extremely low frequency has been still a big challenge in the fields of elastic metamaterials. In this paper, we propose a new metamaterial based on the idea of the zero rotational stiffness, to achieve extremely low frequency stop band for flexural elastic waves. Unlike the previous ways to achieve the stop band, we found that the zero rotational stiffness can provide a broad stop band at extremely low frequency, which starts from even almost zero frequency. To achieve the zero rotational stiffness, we propose a new elastic metamaterial consisting of blocks and links with the hinge connection. Analytic developments as well as numerical simulations evidence that this new metamaterial can exhibit extremely low and broad stop band, even at the quasi-static ranges. In addition, the metamaterial is shown to exhibit the negative group velocity at extremely low frequency ranges, as well as the quasi-static stop band, if it is properly designed. PMID:27651146

  13. Packaging and Performance of 980nm Broad Area Semiconductor Lasers

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    High power broad area semiconductor lasers have found increasing applications in pumping of solid state laser systems and fiber amplifiers, frequency doubling, medical systems and material processing.Packaging including the assembly design, process and thermal management, has a significant impact on the optical performance and reliability of a high power broad area laser. In this paper, we introduce the package structures and assembling process of 980nm broad area lasers and report the performances including output power, thermal behavior and far fields.We will report two types of high power broad area laser assemblies.One is a microchannel liquid cooled assembly and the other is a conduction cooled CT-mount assembly. Optical powers of 15W and 10W were achieved from a 980nm broad area laser with a 120 μ m stripe width in a microchannel liquid cooled assembly and conduction cooled CT-mount assembly, respectively.Furthermore,a high power of 6.5W out of fiber was demonstrated from a pigtailed, fully packaged butterfly-type module without TEC (Thermoelectric cooler).The measurement results showed that thermal management is the key in not only improving output power, but also significantly improving beam divergence and far field distribution.The results also showed that the die attach solder can significant impact the reliability of high power broad area lasers and that indium solder is not suitable for high power laser applications due to electromigration at high current densities and high temperatures.

  14. William Band at Yenching University

    Science.gov (United States)

    Hu, Danian

    2008-04-01

    William Band (1906-1993) has been widely remembered by his American colleagues and students as ``a fine physicist and teacher,'' who taught at Washington State University in Pullman between 1949 and 1971 and authored Introduction to Quantum Statistics (1954) and Introduction to Mathematical Physics (1959). Not many, however, knew much about Band's early career, which was very ``uncommon and eventful.'' Born in England, Band graduated from University of Liverpool in 1927 with an MsSc degree in physics. Instead of pursuing his Ph.D. at Cambridge, he chose to teach physics at Yenching University, a prestigious Christian university in Beijing, China. Arriving in 1929, Band established his career at Yenching, where he taught and researched the theory of relativity and quantum mechanics, pioneered the study on low-temperature superconductivity in China, founded the country's first graduate program in physics, and chaired the Physics Department for 10 years until he fled from Yenching upon hearing of the attack on Pearl Harbor. It took him two years to cross Japanese occupied areas under the escort of the Communist force; he left China in early 1945. This presentation will explore Band's motivation to work in China and his contributions to the Chinese physics research and education.

  15. Rotational band in 12C based on the Hoyle state

    Directory of Open Access Journals (Sweden)

    Ogloblin A.A.

    2014-03-01

    Full Text Available α + 12C inelastic differential cross-sections were measured at the energies 65 and 110 MeV. A new broad state at 13.75 MeV was observed. Its spin-parity has been determined as 4+ and the diffraction radius of the corresponding L = 4 transition is ~ 0.8 fm larger than that of the excitation of the 4+, 14.8 MeV level. The 13.75 MeV state was considered to be the third member of the rotational band based on the Hoyle state.

  16. X-Band PLL Synthesizer

    Directory of Open Access Journals (Sweden)

    P. Kutin

    2006-04-01

    Full Text Available This paper deals with design and realization of a PLL synthesizer for the microwave X−band. The synthesizer is intended for use as a local oscillator in a K−band downconverter. The design goal was to achieve very low phase noise and spurious free signal with a sufficient power level. For that purpose a low phase noise MMIC VCO was used in phase locked loop. The PLL works at half the output frequency, therefore there is a frequency doubler at the output of the PLL. The output signal from the frequency doubler is filtered by a band-pass filter and finally amplified by a single stage amplifier.

  17. Holographic Multi-Band Superconductor

    CERN Document Server

    Huang, Ching-Yu; Maity, Debaprasad

    2011-01-01

    We propose a gravity dual for the holographic superconductor with multi-band carriers. Moreover, the currents of these carriers are unified under a global non-Abelian symmetry, which is dual to the bulk non-Abelian gauge symmetry. We study the phase diagram of our model, and find it qualitatively agrees with the one for the realistic 2-band superconductor, such as MgB2. We also evaluate the holographic conductivities and find the expected mean-field like behaviors in some cases. However, for a wide range of the parameter space, we also find the non-mean-field like behavior with negative conductivities.

  18. X-Band PLL Synthesizer

    OpenAIRE

    P. Kutin; Vagner, P.

    2006-01-01

    This paper deals with design and realization of a PLL synthesizer for the microwave X−band. The synthesizer is intended for use as a local oscillator in a K−band downconverter. The design goal was to achieve very low phase noise and spurious free signal with a sufficient power level. For that purpose a low phase noise MMIC VCO was used in phase locked loop. The PLL works at half the output frequency, therefore there is a frequency doubler at the output of the PLL. The output signal ...

  19. A Dual Ridge Broadband Orthomode Transducer for the 7-mm Band

    Science.gov (United States)

    Reyes, Nicolas; Zorzi, Pablo; Pizarro, Jose; Finger, Ricardo; Mena, F. Patricio; Bronfman, Leonardo

    2012-12-01

    In this work we present a Q-band waveguide orthomode transducer (OMT) based on a dual ridge structure. It was designed to be used in astronomical projects were an excellent broad-band performance is mandatory. Of particular interest is the case of ALMA Band 1 (originally set at 31-45 GHz) project which will need several OMTs with outstanding performance and demonstrated manufacturability. By using a symmetrical structure, low cross-polar level and good input matching are achieved over a broad bandwidth (37 %). The proposed design incorporates an octagonal mode converter which allows the unit to be directly mated with the horn avoiding cross-polar issues at the interface. The OMT was designed to have a compact configuration and easiness of fabrication, both crucial features in projects where several units (up to 70) have to be constructed.

  20. Bid Optimization in Broad-Match Ad auctions

    CERN Document Server

    Even-dar, Eyal; Mirrokni, Vahab; Muthukrishnan, S; Nadav, Uri

    2009-01-01

    Ad auctions in sponsored search support ``broad match'' that allows an advertiser to target a large number of queries while bidding only on a limited number. While giving more expressiveness to advertisers, this feature makes it challenging to optimize bids to maximize their returns: choosing to bid on a query as a broad match because it provides high profit results in one bidding for related queries which may yield low or even negative profits. We abstract and study the complexity of the {\\em bid optimization problem} which is to determine an advertiser's bids on a subset of keywords (possibly using broad match) so that her profit is maximized. In the query language model when the advertiser is allowed to bid on all queries as broad match, we present an linear programming (LP)-based polynomial-time algorithm that gets the optimal profit. In the model in which an advertiser can only bid on keywords, ie., a subset of keywords as an exact or broad match, we show that this problem is not approximable within any ...

  1. Antiviral Therapy by HIV-1 Broadly Neutralizing and Inhibitory Antibodies

    Directory of Open Access Journals (Sweden)

    Zhiqing Zhang

    2016-11-01

    Full Text Available Human immunodeficiency virus type 1 (HIV-1 infection causes acquired immune deficiency syndrome (AIDS, a global epidemic for more than three decades. HIV-1 replication is primarily controlled through antiretroviral therapy (ART but this treatment does not cure HIV-1 infection. Furthermore, there is increasing viral resistance to ART, and side effects associated with long-term therapy. Consequently, there is a need of alternative candidates for HIV-1 prevention and therapy. Recent advances have discovered multiple broadly neutralizing antibodies against HIV-1. In this review, we describe the key epitopes on the HIV-1 Env protein and the reciprocal broadly neutralizing antibodies, and discuss the ongoing clinical trials of broadly neutralizing and inhibitory antibody therapy as well as antibody combinations, bispecific antibodies, and methods that improve therapeutic efficacy by combining broadly neutralizing antibodies (bNAbs with latency reversing agents. Compared with ART, HIV-1 therapeutics that incorporate these broadly neutralizing and inhibitory antibodies offer the advantage of decreasing virus load and clearing infected cells, which is a promising prospect in HIV-1 prevention and treatment.

  2. Antiviral Therapy by HIV-1 Broadly Neutralizing and Inhibitory Antibodies.

    Science.gov (United States)

    Zhang, Zhiqing; Li, Shaowei; Gu, Ying; Xia, Ningshao

    2016-11-18

    Human immunodeficiency virus type 1 (HIV-1) infection causes acquired immune deficiency syndrome (AIDS), a global epidemic for more than three decades. HIV-1 replication is primarily controlled through antiretroviral therapy (ART) but this treatment does not cure HIV-1 infection. Furthermore, there is increasing viral resistance to ART, and side effects associated with long-term therapy. Consequently, there is a need of alternative candidates for HIV-1 prevention and therapy. Recent advances have discovered multiple broadly neutralizing antibodies against HIV-1. In this review, we describe the key epitopes on the HIV-1 Env protein and the reciprocal broadly neutralizing antibodies, and discuss the ongoing clinical trials of broadly neutralizing and inhibitory antibody therapy as well as antibody combinations, bispecific antibodies, and methods that improve therapeutic efficacy by combining broadly neutralizing antibodies (bNAbs) with latency reversing agents. Compared with ART, HIV-1 therapeutics that incorporate these broadly neutralizing and inhibitory antibodies offer the advantage of decreasing virus load and clearing infected cells, which is a promising prospect in HIV-1 prevention and treatment.

  3. Broad-line Reverberation in the Kepler-field Seyfert Galaxy Zw 229-015

    Science.gov (United States)

    Barth, Aaron J.; Nguyen, My L.; Malkan, Matthew A.; Filippenko, Alexei V.; Li, Weidong; Gorjian, Varoujan; Joner, Michael D.; Bennert, Vardha Nicola; Botyanszki, Janos; Cenko, S. Bradley; Childress, Michael; Choi, Jieun; Comerford, Julia M.; Cucciara, Antonino; da Silva, Robert; Duchêne, Gaspard; Fumagalli, Michele; Ganeshalingam, Mohan; Gates, Elinor L.; Gerke, Brian F.; Griffith, Christopher V.; Harris, Chelsea; Hintz, Eric G.; Hsiao, Eric; Kandrashoff, Michael T.; Keel, William C.; Kirkman, David; Kleiser, Io K. W.; Laney, C. David; Lee, Jeffrey; Lopez, Liliana; Lowe, Thomas B.; Moody, J. Ward; Morton, Alekzandir; Nierenberg, A. M.; Nugent, Peter; Pancoast, Anna; Rex, Jacob; Rich, R. Michael; Silverman, Jeffrey M.; Smith, Graeme H.; Sonnenfeld, Alessandro; Suzuki, Nao; Tytler, David; Walsh, Jonelle L.; Woo, Jong-Hak; Yang, Yizhe; Zeisse, Carl

    2011-05-01

    The Seyfert 1 galaxy Zw 229-015 is among the brightest active galaxies being monitored by the Kepler mission. In order to determine the black hole mass in Zw 229-015 from Hβ reverberation mapping, we have carried out nightly observations with the Kast Spectrograph at the Lick 3 m telescope during the dark runs from 2010 June through December, obtaining 54 spectroscopic observations in total. We have also obtained nightly V-band imaging with the Katzman Automatic Imaging Telescope at Lick Observatory and with the 0.9 m telescope at the Brigham Young University West Mountain Observatory over the same period. We detect strong variability in the source, which exhibited more than a factor of two change in broad Hβ flux. From cross-correlation measurements, we find that the Hβ light curve has a rest-frame lag of 3.86+0.69 -0.90 days with respect to the V-band continuum variations. We also measure reverberation lags for Hα and Hγ and find an upper limit to the Hδ lag. Combining the Hβ lag measurement with a broad Hβ width of σline = 1590 ± 47 km s-1 measured from the rms variability spectrum, we obtain a virial estimate of M BH = 1.00+0.19 -0.24 × 107 M sun for the black hole in Zw 229-015. As a Kepler target, Zw 229-015 will eventually have one of the highest-quality optical light curves ever measured for any active galaxy, and the black hole mass determined from reverberation mapping will serve as a benchmark for testing relationships between black hole mass and continuum variability characteristics in active galactic nuclei.

  4. Modelling photometric reverberation data -- a disk-like broad line region and larger black hole mass for 3C120

    CERN Document Server

    Nuñez, F Pozo; Ramolla, M; Westhues, C; Haas, M; Chini, R; Steenbrugge, K; Lemke, R; Murphy, M

    2013-01-01

    We consider photometric reverberation mapping, where the nuclear continuum variations are monitored via a broad band filter and the echo of emission line clouds of the broad line region (BLR) is measured with a suitable narrow band (NB) filter. We investigate how an incomplete emission line coverage by the NB filter influences the BLR size determination. This includes two basic cases: 1) a symmetric cut of the blue and red part of the line wings, and 2) the filter positioned asymmetrically to the line center so that essentially a complete half of the emission line is contained in the NB filter. We find that symmetric cutting of line wings may lead to an overestimate of the BLR size which is less than 5%. The case of asymmetric line coverage, as for our data of the Seyfert-1 galaxy 3C120, yields the BLR size with less than 1% bias. Our results suggest that any BLR size bias due to narrow-band line cut in photometric reverberation mapping is small and in most cases negligible. We use well sampled photometric re...

  5. 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."

  6. Bands for girls and boys

    Institute of Scientific and Technical Information of China (English)

    王为成

    2001-01-01

    Like many people, you may be dreaming of a career(职业) as rock and roll stars. There are two ways to go about getting one. First is the traditional way. Find some friends and form a group. Learn to play the guitar or the drums. Write your own songs. Spend hours arguing about the band name. Then go out on the road.

  7. A PHOTONIC BAND GAP FIBRE

    DEFF Research Database (Denmark)

    1999-01-01

    An optical fibre having a periodicidal cladding structure provididing a photonic band gap structure with superior qualities. The periodical structure being one wherein high index areas are defined and wherein these are separated using a number of methods. One such method is the introduction...

  8. Familial band-shaped keratopathy.

    Science.gov (United States)

    Ticho, U; Lahav, M; Ivry, M

    1979-01-01

    A brother and sister out of a consanguinous family of four siblings are presented as prototypes of primary band-shaped keratopathy. The disease manifested sever progressive changes of secondary nature over two years of follow-up. Histology and treatment are described.

  9. K-Band Latching Switches

    Science.gov (United States)

    Piotrowski, W. S.; Raue, J. E.

    1984-01-01

    Design, development, and tests are described for two single-pole-double-throw latching waveguide ferrite switches: a K-band switch in WR-42 waveguide and a Ka-band switch in WR-28 waveguide. Both switches have structurally simple junctions, mechanically interlocked without the use of bonding materials; they are impervious to the effects of thermal, shock, and vibration stresses. Ferrite material for the Ka-band switch with a proper combination of magnetic and dielectric properties was available and resulted in excellent low loss, wideband performance. The high power handling requirement of the K-band switch limited the choice of ferrite to nickel-zinc compositions with adequate magnetic properties, but with too low relative dielectric constant. The relative dielectric constant determines the junction dimensions for given frequency responses. In this case the too low value unavoidably leads to a larger than optimum junction volume, increasing the insertion loss and restricting the operating bandwidth. Efforts to overcome the materials-related difficulties through the design of a composite junction with increased effective dielectric properties efforts to modify the relative dielectric constant of nickel-zinc ferrite are examined.

  10. K-band latching switches

    Science.gov (United States)

    Piotrowski, W. S.; Raue, J. E.

    1984-05-01

    Design, development, and tests are described for two single-pole-double-throw latching waveguide ferrite switches: a K-band switch in WR-42 waveguide and a Ka-band switch in WR-28 waveguide. Both switches have structurally simple junctions, mechanically interlocked without the use of bonding materials; they are impervious to the effects of thermal, shock, and vibration stresses. Ferrite material for the Ka-band switch with a proper combination of magnetic and dielectric properties was available and resulted in excellent low loss, wideband performance. The high power handling requirement of the K-band switch limited the choice of ferrite to nickel-zinc compositions with adequate magnetic properties, but with too low relative dielectric constant. The relative dielectric constant determines the junction dimensions for given frequency responses. In this case the too low value unavoidably leads to a larger than optimum junction volume, increasing the insertion loss and restricting the operating bandwidth. Efforts to overcome the materials-related difficulties through the design of a composite junction with increased effective dielectric properties efforts to modify the relative dielectric constant of nickel-zinc ferrite are examined.

  11. Folded cavity angled-grating broad-area lasers.

    Science.gov (United States)

    Zhao, Yunsong; Zhu, Lin

    2013-10-01

    The angled-grating broad-area laser is a promising candidate for high power, high brightness diode laser source. The key point in the design is the angled gratings which can simultaneously support the unique snake-like zigzag lasing mode and eliminate the direct Fabry-Perot (FP) feedback. Unlike a conventional laser waveguide mode, the phase front of the zigzag mode periodically changes along the propagation direction. By use of the mirror symmetry of the zigzag mode, we propose and demonstrate the folded cavity angled-grating broad-area lasers. One benefit of this design is to reduce the required wafer space compared to a regular angled-grating broad-area laser, especially in a long cavity laser for high power operation. Experimental results show that the folded cavity laser exhibits good beam quality in far field with a slightly larger threshold and smaller slope efficiency due to the additional interface loss.

  12. Surface Roughness Effects on Discharge Coefficient of Broad Crested Weir

    Directory of Open Access Journals (Sweden)

    Shaker A. Jalil

    2014-06-01

    Full Text Available The aim of this study is to investigate the effects of surface roughness sizes on the discharge coefficient for a broad crested weirs. For this purpose, three models having different lengths of broad crested weirs were tested in a horizontal flume. In each model, the surface was roughed four times. Experimental results of all models showed that the logical negative effect of roughness increased on the discharge (Q for different values of length. The performance of broad crested weir improved with decrease ratio of roughness to the weir height (Ks/P and with the increase of the total Head to the Length (H/L. An empirical equation was obtained to estimate the variation of discharge coefficient Cd in terms total head to length ratio, with total head to roughness ratio.

  13. Broad ligament pregnancy a diagnostic dilemma: a case report

    Directory of Open Access Journals (Sweden)

    Amit Gupta

    2016-07-01

    Full Text Available Broad ligament pregnancy is one of the rarest forms of ectopic pregnancy with high risk of maternal mortality. Although ultrasonography is usually helpful in making the diagnosis but it is mostly established during laparotomy. 34 year old G2P1 with previous caesarean section reported at 8th month of pregnancy with inability to perceive foetal movements. Ultrasonography confirmed intrauterine fetal demise. Patient was taken for caesarean section after failed induction. Intraoperative diagnosis of broad ligament pregnancy was made and broad ligament along with fetus, sac, fallopian tube and ovary was excised. Post-operative period was uneventful. [Int J Reprod Contracept Obstet Gynecol 2016; 5(7.000: 2478-2480

  14. Polarization-Controlled Broad Color Palette Based on an Ultrathin One-Dimensional Resonant Grating Structure

    Science.gov (United States)

    Koirala, Ishwor; Shrestha, Vivek Raj; Park, Chul-Soon; Lee, Sang-Shin; Choi, Duk-Yong

    2017-01-01

    Highly efficient polarization-tuned structural color filters, which are based on a one- dimensional resonant aluminum grating that is integrated with a silicon nitride waveguide, are proposed and demonstrated to feature a broad color palette. For such a metallic grating structure, transmissive color filtering is only feasible for the incident transverse-magnetic (TM) polarization due to its high reflection regarding the transverse-electric (TE) case; however, polarization-tuned customized colors can be efficiently achieved by optimizing the structural parameters like the duty ratio of the metallic grating. For the fabricated color filters, the transmission peaks, which are imputed to the resonance between the incident light and the guided modes that are supported by the dielectric waveguide, provided efficiencies as high as 90% and 70% for the TM and TE polarizations, respectively, as intended. Through the tailoring of the polarization, a group of filters with different grating periods were successfully exploited to produce a broad color palette spanning the entire visible band. Lastly, a nanoscale alphabetic pattern featuring a flexible combination of colorations was practically constructed via an arrangement of horizontal and vertical gratings.

  15. Discovery of Broad Soft X-ray Absorption Lines from the Quasar Wind in PDS 456

    CERN Document Server

    Reeves, James; Nardini, Emanuele; Behar, Ehud; O'Brien, Paul; Tombesi, Francesco; Turner, Tracey Jane; Costa, Michele

    2016-01-01

    High resolution soft X-ray spectroscopy of the prototype accretion disk wind quasar, PDS 456, is presented. Here, the XMM-Newton RGS spectra are analyzed from the large 2013-2014 XMM-Newton campaign, consisting of 5 observations of approximately 100 ks in length. During the last observation (hereafter OBS. E), the quasar is at a minimum flux level and broad absorption line profiles are revealed in the soft X-ray band, with typical velocity widths of $\\sigma_{\\rm v}\\sim 10,000$ km s$^{-1}$. During a period of higher flux in the 3rd and 4th observations (OBS. C and D, respectively), a very broad absorption trough is also present above 1 keV. From fitting the absorption lines with models of photoionized absorption spectra, the inferred outflow velocities lie in the range $\\sim 0.1-0.2c$. The absorption lines likely originate from He and H-like neon and L-shell iron at these energies. Comparison with earlier archival data of PDS 456 also reveals similar absorption structure near 1 keV in a 40 ks observation in 20...

  16. The Spectral Energy Distribution of Fermi bright blazars

    CERN Document Server

    Abdo, A A; Ajello, M; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Baughman, B M; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, R D; Bloom, E D; Bonamente, E; Borgland, A; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, T H; Buson, S; Caliandro, G A; Cameron, R A; Caraveo, P A; Casandjian, J M; Cavazzuti, E; Cecchi, C; Celik, O; Charles, E; Chaty, S; Chekhtman, A; Chiang, J; Ciprini, S; Claus, R; Cohen-Tanugi, J; Colafrancesco, S; Cominsky, L R; Conrad, J; Costamante, L; Cutini, S; Dermer, C D; de Angelis, A; de Palma, F; Digel, S W; Silva, E do Couto e; Drell, P S; Dubois, R; Dumora, D; Farnier, C; Favuzzi, C; Fegan, S J; Focke, W B; Fortin, P; Frailis, M; Fuhrmann, L; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, N; Giommi, P; Giordano, F; Glanzman, T; Godfrey, G; Grenier, I A; Grove, J E; Guillemot, L; Guiriec, S; Hadasch, D; Hanabata, Y; Harding, A K; Hayashida, M; Hays, E; Healey, S E; Horan, D; Hughes, R E; Itoh, R; Jackson, M S; Johannesson, G; Johnson, A S; Johnson, W N; Kadler, M; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knodlseder, J; Kocian, M L; Kuss, M; Lande, J; Latronico, L; Longo, F; Loparco, F; Lott, B; Lovellette, M N; Lubrano, P; Madejski, G M; Makeev, A; Max-Moerbeck, W; Mazziotta, M N; McConville, W; McEnery, J E; Meurer, C; Michelson, P F

    2009-01-01

    (Abridged) We have conducted a detailed investigation of the broad-band spectral properties of the \\gamma-ray selected blazars of the Fermi LAT Bright AGN Sample (LBAS). By combining our accurately estimated Fermi gamma-ray spectra with Swift, radio, infra-red, optical and other hard X-ray/gamma-ray data, collected within three months of the LBAS data taking period, we were able to assemble high-quality and quasi-simultaneous Spectral Energy Distributions (SED) for 48 LBAS blazars.The SED of these gamma-ray sources is similar to that of blazars discovered at other wavelengths, clearly showing, in the usual Log $\

  17. Broad-Line Reverberation in the Kepler-Field Seyfert Galaxy Zw 229-015

    CERN Document Server

    Barth, A J; Malkan, M A; Filippenko, A V; Li, W; Gorjian, V; Joner, M D; Bennert, V N; Botyanszki, J; Cenko, S B; Childress, M; Choi, J; Comerford, J M; Cucciara, A; da Silva, R; Duchene, G; Fumagalli, M; Ganeshalingam, M; Gates, E L; Gerke, B F; Griffith, C V; Harris, C; Hintz, E G; Hsiao, E; Kandrashoff, M T; Keel, W C; Kirkman, D; Kleiser, I K W; Laney, C D; Lee, J; Lopez, L; Lowe, T B; Moody, J W; Morton, A; Nierenberg, A M; Nugent, P; Pancoast, A; Rex, J; Rich, R M; Silverman, J M; Smith, G H; Sonnenfeld, A; Suzuki, N; Tytler, D; Walsh, J L; Woo, J -H; Yang, Y; Zeisse, C

    2011-01-01

    The Seyfert 1 galaxy Zw 229-015 is among the brightest active galaxies being monitored by the Kepler mission. In order to determine the black hole mass in Zw 229-015 from H-beta reverberation mapping, we have carried out nightly observations with the Kast Spectrograph at the Lick 3m telescope during the dark runs from June through December 2010, obtaining 54 spectroscopic observations in total. We have also obtained nightly V-band imaging with the Katzman Automatic Imaging Telescope at Lick Observatory and with the 0.9m telescope at the Brigham Young University West Mountain Observatory over the same period. We detect strong variability in the source, which exhibited more than a factor of 2 change in broad H-beta flux. From cross-correlation measurements, we find that the H-beta light curve has a rest-frame lag of 3.86(+0.69,-0.90) days with respect to the V-band continuum variations. We also measure reverberation lags for H-alpha and H-gamma and find an upper limit to the H-delta lag. Combining the H-beta la...

  18. Restarting radio activity and dust emission in radio-loud broad absorption line quasars

    CERN Document Server

    Bruni, G; Montenegro-Montes, F M; Brienza, M; González-Serrano, J I

    2015-01-01

    Broad absorption line quasars (BAL QSOs) are objects showing absorption from relativistic outflows, with velocities up to 0.2c. These manifest, in about 15% of quasars, as absorption troughs on the blue side of UV emission lines, such as C iv and Mg ii. In this work, we complement the information collected in the cm band for our previously presented sample of radio loud BAL QSOs with new observations at m and mm bands. Our aim is to verify the presence of old, extended radio components in the MHz range, and probe the emission of dust (linked to star formation) in the mm domain. We observed 5 sources from our sample, already presenting hints of low-frequency emission, with the GMRT at 235 and 610 MHz. Other 17 sources (more than half the sample) were observed with bolometer cameras at IRAM-30m and APEX. All sources observed with the GMRT present extended emission at a scale of tens of kpc. In some cases these measurements allow us to identify a second component in the SED, at frequencies below 1.4 GHz, beyond ...

  19. A Census of Broad-Line Active Galactic Nuclei in Nearby Galaxies: Coeval Star Formation and Rapid Black Hole Growth

    CERN Document Server

    Trump, Jonathan R; Fang, Jerome J; Faber, S M; Koo, David C; Kocevski, Dale D

    2012-01-01

    We present the first quantified, statistical map of broad-line active galactic nucleus (AGN) frequency with host galaxy color and stellar mass in nearby (0.01 < z < 0.11) galaxies. Aperture photometry and z-band concentration measurements from the Sloan Digital Sky Survey (SDSS) are used to dis- entangle AGN and galaxy emission, resulting in estimates of uncontaminated galaxy rest-frame color, luminosity, and stellar mass. Broad-line AGNs are distributed throughout the blue cloud and green valley at a given stellar mass, and are much rarer in quiescent (red sequence) galaxies. This is in contrast to the published host galaxy properties of weaker narrow-line AGNs, indicating that broad-line AGNs occur during a different phase in galaxy evolution. More luminous broad-line AGNs have bluer host galaxies, even at fixed mass, suggesting that the same processes that fuel nuclear activity also efficiently form stars. The data favor processes that simultaneously fuel both star formation activity and rapid superm...

  20. Silver Nanoparticles with Broad Multiband Linear Optical Absorption

    KAUST Repository

    Bakr, Osman M.

    2009-07-06

    A simple one-pot method produces silver nanoparticles coated with aryl thiols that show intense, broad nonplasmonic optical properties. The synthesis works with many aryl-thiol capping ligands, including water-soluble 4-mercaptobenzoic acid. The nanoparticles produced show linear absorption that is broader, stronger, and more structured than most conventional organic and inorganic dyes.

  1. Mathematical Development: The Role of Broad Cognitive Processes

    Science.gov (United States)

    Calderón-Tena, Carlos O.

    2016-01-01

    This study investigated the role of broad cognitive processes in the development of mathematics skills among children and adolescents. Four hundred and forty-seven students (age mean [M] = 10.23 years, 73% boys and 27% girls) from an elementary school district in the US southwest participated. Structural equation modelling tests indicated that…

  2. PRINCIPAR An Efficient, Broad-coverage, Principle-based Parser

    CERN Document Server

    Lin, D

    1994-01-01

    We present an efficient, broad-coverage, principle-based parser for English. The parser has been implemented in C++ and runs on SUN Sparcstations with X-windows. It contains a lexicon with over 90,000 entries, constructed automatically by applying a set of extraction and conversion rules to entries from machine readable dictionaries.

  3. Model Invariance across Genders of the Broad Autism Phenotype Questionnaire

    Science.gov (United States)

    Broderick, Neill; Wade, Jordan L.; Meyer, J. Patrick; Hull, Michael; Reeve, Ronald E.

    2015-01-01

    ASD is one of the most heritable neuropsychiatric disorders, though comprehensive genetic liability remains elusive. To facilitate genetic research, researchers employ the concept of the broad autism phenotype (BAP), a milder presentation of traits in undiagnosed relatives. Research suggests that the BAP Questionnaire (BAPQ) demonstrates…

  4. ALMA Band 5 Cartridge Performance

    Science.gov (United States)

    Billade, Bhushan; Lapkin, I.; Nystrom, O.; Sundin, E.; Fredrixon, M.; Finger, R.; Rashid, H.; Desmaris, V.; Meledin, D.; Pavolotsky, A.; Belitsky, Victor

    2010-03-01

    Work presented here concerns the design and performance of the ALMA Band 5 cold cartridge, one of the 10 frequency channels of ALMA project, a radio interferometer under construction at Atacama Desert in Chile. The Band 5 cartridge is a dual polarization receiver with the polarization separation performed by orthomode transducer (OMT). For each polarization, Band 5 receiver employs sideband rejection (2SB) scheme based on quadrature layout, with SIS mixers covering 163-211 GHz with 4-8 GHz IF. The LO injection circuitry is integrated with mixer chip and is implemented on the same substrate, resulting in a compact 2SB assembly. Amongst the other ALMA bands, the ALMA Band 5 being the lowest frequency band that uses all cold optics, has the largest mirror. Consequently, ALMA Band 5 mirror along with its support structure leaves very little room for placing OMT, mixers and IF subsystems. The constraints put by the size of cold optics and limited cartridge space, required of us to revise the original 2SB design and adopt a design where all the components like OMT, mixer, IF hybrid, isolators and IF amplifier are directly connected to each other without using any co-ax cables in-between. The IF subsystem uses the space between 4 K and 15 K stage of the cartridge and is thermally connected to 4 K stage. Avoiding co-ax cabling required use of custom designed IF hybrid, furthermore, due to limited cooling capacity at 4 K stage, resistive bias circuitry for the mixers is moved to 15 K stage and the IF hybrid along with an integrated bias-T is implemented using superconducting micro-strip lines. The E-probes for both LO and RF waveguide-to-microstrip transitions are placed perpendicular to the wave direction (back-piece configuration). The RF choke at the end of the probes provides a virtual ground for the RF/LO signal, and the choke is DC grounded to the chassis. The on-chip LO injection is done using a microstrip line directional coupler with slot-line branches in the

  5. Purification of the major UsnRNPs from broad bean nuclear extracts and characterization of their protein constituents.

    OpenAIRE

    1989-01-01

    Small nuclear ribonucleoprotein particles containing the five major nucleoplasmic snRNAs U1, U2, U4, U5 and U6 as well as two smaller sized snRNAs were purified from broad bean nuclear extracts by anti-m3G, monoclonal antibody, immunoaffinity chromatography. We have so far defined 13 polypeptides of approximate mol. wts. of 11 kd, 11.5 kd, 12.5 kd, 16 kd, 17 kd, 17.5 kd, 18.5 kd, 25 kd (double band), 30 kd, 31 kd, 35 kd, 36 kd and 54 kd. Upon fractionation of the UsnRNPs by anion exchange chr...

  6. S-Band propagation measurements

    Science.gov (United States)

    Briskman, Robert D.

    1994-08-01

    A geosynchronous satellite system capable of providing many channels of digital audio radio service (DARS) to mobile platforms within the contiguous United States using S-band radio frequencies is being implemented. The system is designed uniquely to mitigate both multipath fading and outages from physical blockage in the transmission path by use of satellite spatial diversity in combination with radio frequency and time diversity. The system also employs a satellite orbital geometry wherein all mobile platforms in the contiguous United States have elevation angles greater than 20 deg to both of the diversity satellites. Since implementation of the satellite system will require three years, an emulation has been performed using terrestrial facilities in order to allow evaluation of DARS capabilities in advance of satellite system operations. The major objective of the emulation was to prove the feasibility of broadcasting from satellites 30 channels of CD quality programming using S-band frequencies to an automobile equipped with a small disk antenna and to obtain quantitative performance data on S-band propagation in a satellite spatial diversity system.

  7. [Spatial analysis of LAIe of montane evergreen broad-leaved forest in southwest Sichuan, Northwest China, based on image texture].

    Science.gov (United States)

    Zhao, An-Jiu; Yang, Chang-Qing; Liao, Cheng-Yun

    2014-11-01

    Optical remote sensing is still one of the most attractive choices for obtaining leaf area index (LAI) information, but currently may be derived from remotely sensed data with limited accuracy. Effective leaf area index (LAIe) of montane evergreen broad-leaved forest in southwest Sichuan was inventoried and assessed in 83 sample field plots of 20 m x 20 m using different types of image processing techniques, including simple spectral band, simple spectral band ratios and principal component. Texture information was extracted by gray level co-occurrence matrices (GLCM) from different types of processing image. The results showed that there were correlations of different degrees between LAIe and texture parameters, and highly significant correlations were observed between LAIe with the homogeneity of the B1 band, B1/B4 band ratio or principal component PC1. Using texture information of remotely sensed data as auxiliary variables, we developed geostatistics models. Compared with the model based on NDVI auxiliary variable, the accuracy of LAIe were improved, presenting an increase by 5.3% with the homogeneity of the B1 band, 11.0% with the homogeneity B1/B4 band ratio, and 14.5% with the homogeneity principal component PC1, and the statistical errors were also reduced to some extent. The optimal LAIe model of spatial geostatistics was obtained when taking NDVI and homogeneity principal component PC1 as auxiliary variables (R2 = 0.840, RMSE = 0.212). Our results provided a new way to estimate regional spatial distribution of LAI using other auxiliary variables besides the vegetation index.

  8. Origin of the ``Red'' Luminescence Band in Bulk N-doped ZnO

    Science.gov (United States)

    Glaser, E. R.; Garces, N. Y.; Tarun, M. C.; McCluskey, M. D.

    2012-02-01

    Optically detected magnetic resonance (ODMR) at 24 GHz was performed on bulk ZnO crystals doped with nitrogen impurities (of high interest for p-type conductivity) to provide more details on the origin of a recently reported red/near-IR photoluminescence (PL) band.ootnotetextM.C. Tarun et al., AIP Advances 1, 022105 (2011). PL at 7K revealed strong bandedge excitonic recombination at 3.364 eV, a broad ``green'' emission band at 2.45 eV, and a broad ``red'' PL band near 1.7 eV. Two luminescence-increasing ODMR signals were found on this ``red'' emission. The first was a sharp feature with g-value of 1.957 and FWHM of 1 mT and is attributed to shallow donors based on electron spin resonance (ESR) of n-type ZnO. The second feature exhibited a g-value near 2 and a broad, asymmetric lineshape with FWHM of ˜ 10 mT. A simulation of the spectrum showed that the broad resonance could be fit as the sum of three equally spaced lines with magnetic field splitting value and relative intensities in close agreement to those observed for deep nitrogen acceptors as identified from previous ESR studies. Thus, the ODMR results strongly suggest that the ``red'' PL is due to radiative recombination involving residual shallow donors and deep nitrogen acceptor centers.

  9. An extension to flat band ferromagnetism

    Science.gov (United States)

    Gulacsi, M.; Kovacs, G.; Gulacsi, Z.

    2014-11-01

    From flat band ferromagnetism, we learned that the lowest energy half-filled flat band gives always ferromagnetism if the localized Wannier states on the flat band satisfy the connectivity condition. If the connectivity conditions are not satisfied, ferromagnetism does not appear. We show that this is not always the case namely, we show that ferromagnetism due to flat bands can appear even if the connectivity condition does not hold due to a peculiar behavior of the band situated just above the flat band.

  10. Design and experimental verification of a dual-band metamaterial filter

    Science.gov (United States)

    Zhu, Hong-Yang; Yao, Ai-Qin; Zhong, Min

    2016-10-01

    In this paper, we present the design, simulation, and experimental verification of a dual-band free-standing metamaterial filter operating in a frequency range of 1 THz-30 THz. The proposed structure consists of periodically arranged composite air holes, and exhibits two broad and flat transmission bands. To clarify the effects of the structural parameters on both resonant transmission bands, three sets of experiments are performed. The first resonant transmission band shows a shift towards higher frequency when the side width w 1 of the main air hole is increased. In contrast, the second resonant transmission band displays a shift towards lower frequency when the side width w 2 of the sub-holes is increased, while the first resonant transmission band is unchanged. The measured results indicate that these resonant bands can be modulated individually by simply optimizing the relevant structural parameters (w 1 or w 2) for the required band. In addition, these resonant bands merge into a single resonant band with a bandwidth of 7.7 THz when w 1 and w 2 are optimized simultaneously. The structure proposed in this paper adopts different resonant mechanisms for transmission at different frequencies and thus offers a method to achieve a dual-band and low-loss filter. Project supported by the Doctorate Scientific Research Foundation of Hezhou University, China (Grant No. HZUBS201503), the Promotion of the Basic Ability of Young and Middle-aged Teachers in Universities Project of Guangxi Zhuang Autonomous Region, China (Grant No. KY2016YB453), the Guangxi Colleges and Universities Key Laboratory Symbolic Computation, China, Engineering Data Processing and Mathematical Support Autonomous Discipline Project of Hezhou University, China (Grant No. 2016HZXYSX01).

  11. Dynamic Beam Shaping Using a Dual-Band Metasurface-Inspired Electronically Tunable Reflectarray Antenna

    CERN Document Server

    Tayebi, Amin; Paladhi, Pavel Roy; Udpa, Lalita; Udpa, Satish; Rothwell, Edward

    2015-01-01

    An electronically reconfigurable dual-band-reflectarray antenna is presented in this paper. The tunable unit cell, a ring loaded square patch with a single varactor diode connected across the gap between the ring and the patch, is modeled using both a full-wave solver and an equivalent circuit. The parameters of the equivalent circuit are calculated independently of the simulation and experiment using analysis techniques employed in frequency selective surfaces. The reflection phase of the proposed unit cell is shown to provide an excellent phase range of 335$^{\\circ}$ in F band and 340$^{\\circ}$ in S band. Results from the analysis are used to design and build a 10x10 element reflectarray antenna. The high tuning phase range of each element allows the fabricated reflectarray to demonstrate a very broad steering range of up to $\\pm$60$^{\\circ}$ in both frequency bands.

  12. Permissiveness of soil microbial communities towards broad host range plasmids

    DEFF Research Database (Denmark)

    Klümper, Uli

    larger than previously assumed. I was able to show abundant plasmid transfer from the Gram negative donor strains to a wide diversity of Gram positive soil bacteria, formerly thought to constitute distinct clusters of gene transfer. Moreover, among the observed transconjugants, I identified a core super...... environmental factors that modulate plasmid transfer in soil microbial communities. In order to attain these goals, I developed a high-throughput method that enabled me to evaluate the permissiveness of bacterial communities towards introduced plasmids. This new approach is based on the introduction...... fraction of soil the bacteria (up to 1 in 10,000) were able to take up any of these broad host range conjugal plasmids. The transconjugal pools comprised 11 bacterial phyla. This finding indicates that the realized transfer range of broad host range plasmids in environmental microbial communities is much...

  13. 30 GHz monitoring of broad absorption line (BAL) quasars

    CERN Document Server

    Ceglowski, Maciej; Pazderska, Bogna; Gawronski, Marcin

    2014-01-01

    Broad absorption line (BAL) quasars have been studied for over thirty years. Yet it is still unclear why and when we observe broad absorption lines in quasars. Is this phenomenon caused by geometry or is it connected with the evolution process? Variability of the BAL quasars, if present, can give us information about their orientation, namely it can indicate whether they are oriented more pole-on. Using the Torun 32-metre dish equipped with the One Centimetre Receiver Array (OCRA) we have started a monitoring campaign of a sample of compact radio-loud BAL quasars. This 30 GHz variability monitoring program supplements the high-resolution interferometric observations of these objects we have carried out with the EVN and VLBA.

  14. Flow characteristics at trapezoidal broad-crested side weir

    Directory of Open Access Journals (Sweden)

    Říha Jaromír

    2015-06-01

    Full Text Available Broad-crested side weirs have been the subject of numerous hydraulic studies; however, the flow field at the weir crest and in front of the weir in the approach channel still has not been fully described. Also, the discharge coefficient of broad-crested side weirs, whether slightly inclined towards the stream or lateral, still has yet to be clearly determined. Experimental research was carried out to describe the flow characteristics at low Froude numbers in the approach flow channel for various combinations of in- and overflow discharges. Three side weir types with different oblique angles were studied. Their flow characteristics and discharge coefficients were analyzed and assessed based on the results obtained from extensive measurements performed on a hydraulic model. The empirical relation between the angle of side weir obliqueness, Froude numbers in the up- and downstream channels, and the coefficient of obliqueness was derived.

  15. Evolution of Broad-line Emission from Active Galactic Nuclei

    CERN Document Server

    Elitzur, Moshe; Trump, Jonathan R

    2013-01-01

    Apart from viewing-dependent obscuration, intrinsic broad-line emission from active galactic nuclei (AGNs) follows an evolutionary sequence: Type $1 \\to 1.2/1.5 \\to 1.8/1.9 \\to 2$ as the accretion rate onto the central black hole is decreasing. This spectral evolution is controlled, at least in part, by the parameter $L_{\\rm bol}/M^{2/3}$, where $L_{\\rm bol}$ is the AGN bolometric luminosity and $M$ is the black hole mass. Both this dependence and the double-peaked profiles that emerge along the sequence arise naturally in the disk-wind scenario for the AGN broad-line region.

  16. Diverse Broad Line Region Kinematic Signatures From Reverberation Mapping

    CERN Document Server

    Denney, K D; Pogge, R W; Adair, A; Atlee, D W; Au-Yong, K; Bentz, M C; Bird, J C; Brokofsky, D J; Chisholm, E; Comins, M L; Dietrich, M; Doroshenko, V T; Eastman, J D; Efimov, Y S; Ewald, S; Ferbey, S; Gaskell, C M; Hedrick, C H; Jackson, K; Klimanov, S A; Klimek, E S; Kruse, A K; Ladéroute, A; Lamb, J B; Leighly, K; Minezaki, T; Nazarov, S V; Onken, C A; Petersen, E A; Peterson, P; Poindexter, S; Sakata, Y; Schlesinger, K J; Sergeev, S G; Skolski, N; Stieglitz, L; Tobin, J J; Unterborn, C; Vestergaard, M; Watkins, A E; Watson, L C; Yoshii, Y

    2009-01-01

    A detailed analysis of the data from a high sampling rate, multi-month reverberation mapping campaign, undertaken primarily at MDM Observatory with supporting observations from telescopes around the world, reveals that the Hbeta emission region within the broad line regions (BLRs) of several nearby AGNs exhibit a variety of kinematic behaviors. While the primary goal of this campaign was to obtain either new or improved Hbeta reverberation lag measurements for several relatively low luminosity AGNs (presented in a separate work), we were also able to unambiguously reconstruct velocity-resolved reverberation signals from a subset of our targets. Through high cadence spectroscopic monitoring of the optical continuum and broad Hbeta emission line variations observed in the nuclear regions of NGC 3227, NGC 3516, and NGC 5548, we clearly see evidence for outflowing, infalling, and virialized BLR gas motions, respectively.

  17. The broad autism phenotype: findings from an epidemiological survey.

    Science.gov (United States)

    Micali, N; Chakrabarti, S; Fombonne, E

    2004-03-01

    This study aimed to determine if relatives of children with autism and less severe pervasive developmental disorders (PDDs) have higher rates of various components of the broad autistic phenotype. Psychiatric and medical disorders were investigated. Parents of children with PDDs were selected from an epidemiological survey and compared with parents of control children with non-autistic developmental problems. Rates of abnormalities and disorders were compared in relatives of 79 cases and 61 controls. Medical and autoimmune disorders in both groups were endorsed by few relatives. Specific developmental disorders were commoner in parents of controls. Depression and anxiety were significantly more prevalent in mothers of children with PDDs. Significantly more PDD children had at least one first-degree relative with anxiety and one second-degree relative with OCD. PDDs were commoner in first-degree relatives. The implications of the findings for the definition of the broad phenotype of autism are discussed.

  18. Flow structure in front of the broad-crested weir

    Directory of Open Access Journals (Sweden)

    Zachoval Zbyněk

    2015-01-01

    Full Text Available The paper deals with research focused on description of flow structure in front of broad-crested weir. Based on experimental measurement, the flow structure in front of the weir (the recirculation zone of flow and tornado vortices and flow structure on the weir crest has been described. The determined flow character has been simulated using numerical model and based on comparing results the suitable model of turbulence has been recommended.

  19. Broad Money Demand and Monetary Policy in Tunisia

    OpenAIRE

    Volker Treichel

    1997-01-01

    The development of empirical foundations to the conduct of monetary policy in Tunisia is the central concern of this paper. Finding stable money demand functions, it broadly corroborates the choice of monetary aggregates as intermediate targets of monetary policy by the Tunisian Central Bank. It finds, however, a lower income elasticity than the one currently applied by the Central Bank and proposes a different methodology for defining monetary growth targets. The paper also finds that both i...

  20. The broad spectrum revisited: Evidence from plant remains

    OpenAIRE

    Weiss, Ehud; Wetterstrom, Wilma; Nadel, Dani; Bar-Yosef, Ofer

    2004-01-01

    The beginning of agriculture is one of the most important developments in human history, with enormous consequences that paved the way for settled life and complex society. Much of the research on the origins of agriculture over the last 40 years has been guided by Flannery's [Flannery, K. V. (1969) in The Domestication and Exploitation of Plants and Animals, eds. Ucko, P. J. & Dimbleby, G. W. (Duckworth, London), pp. 73–100] “broad spectrum revolution” (BSR) hypothesis, which posits that the...

  1. Broad spectrum antiangiogenic treatment for ocular neovascular diseases.

    Directory of Open Access Journals (Sweden)

    Ofra Benny

    Full Text Available UNLABELLED: Pathological neovascularization is a hallmark of late stage neovascular (wet age-related macular degeneration (AMD and the leading cause of blindness in people over the age of 50 in the western world. The treatments focus on suppression of choroidal neovascularization (CNV, while current approved therapies are limited to inhibiting vascular endothelial growth factor (VEGF exclusively. However, this treatment does not address the underlying cause of AMD, and the loss of VEGF's neuroprotective can be a potential side effect. Therapy which targets the key processes in AMD, the pathological neovascularization, vessel leakage and inflammation could bring a major shift in the approach to disease treatment and prevention. In this study we have demonstrated the efficacy of such broad spectrum antiangiogenic therapy on mouse model of AMD. METHODS AND FINDINGS: Lodamin, a polymeric formulation of TNP-470, is a potent broad-spectrum antiangiogenic drug. Lodamin significantly reduced key processes involved in AMD progression as demonstrated in mice and rats. Its suppressive effects on angiogenesis, vascular leakage and inflammation were studied in a wide array of assays including; a Matrigel, delayed-type hypersensitivity (DTH, Miles assay, laser-induced CNV and corneal micropocket assay. Lodamin significantly suppressed the secretion of various pro-inflammatory cytokines in the CNV lesion including monocyte chemotactic protein-1 (MCP-1/Ccl2. Importantly, Lodamin was found to regress established CNV lesions, unlike soluble fms-like tyrosine kinase-1 (sFlk-1. The drug was found to be safe in mice and have little toxicity as demonstrated by electroretinography (ERG assessing retinal and by histology. CONCLUSIONS: Lodamin, a polymer formulation of TNP-470, was identified as a first in its class, broad-spectrum antiangiogenic drug that can be administered orally or locally to treat corneal and retinal neovascularization. Several unique properties

  2. 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.

  3. Relativistic Model for two-band Superconductivity

    OpenAIRE

    Ohsaku, Tadafumi

    2003-01-01

    To understand the superconductivity in MgB2, several two-band models of superconductivity were proposed. In this paper, by using the relativistic fermion model, we clearize the effect of the lower band in the superconductivity.

  4. A Simple Disk Wind Model for Broad Absorption Line Quasars

    CERN Document Server

    Higginbottom, N; Long, K S; Sim, S A; Matthews, J H

    2013-01-01

    Approximately 20% of quasi-stellar objects (QSOs) exhibit broad, blue-shifted absorption lines in their ultraviolet spectra. Such features provide clear evidence for significant outflows from these systems, most likely in the form of accretion disk winds. These winds may represent the "quasar" mode of feedback that is often invoked in galaxy formation/evolution models, and they are also key to unification scenarios for active galactic nuclei (AGN) and QSOs. To test these ideas, we construct a simple benchmark model of an equatorial, biconical accretion disk wind in a QSO and use a Monte Carlo ionization/radiative transfer code to calculate the ultraviolet spectra as a function of viewing angle. We find that for plausible outflow parameters, sightlines looking directly into the wind cone do produce broad, blue-shifted absorption features in the transitions typically seen in broad absorption line QSOs. However, our benchmark model is intrinsically X-ray weak in order to prevent overionization of the outflow, an...

  5. FTIR Spectroscopic Study of Broad Bean 3iseased Leaves

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    [Objective] The aim was to indentify diseased leaves of broad bean by vibra- tional spectroscopy. [Method] In this paper, broad bean rust, fusarium rhizome rot, broad bean zonate spot, yellow leaf curl virus and normal leaves were studied using Fourier transform infrared spectroscopy combined with chemometrics. [Result] The spectra of the samples were similar, only with minor differences in absorption inten- sity of several peaks. Second derivative analyses show that the significant difference of all samples was in the range of 1 200-700 cm2. The data in the range of 1 200- 700 cm' were selected to evaluate correlation coefficients, hierarchical cluster analy- sis (HCA) and principal component analysis (PCA). Results showed that the correla- tion coefficients are larger than 0.928 not only between the healthy leaves, but also between the same diseased leaves. The values between healthy and diseased leaves, and among diseased leaves, are all declined. HCA and PCA yielded about 73.3% and 82.2% accuracy, respectively. [Conclusion] This study demonstrated that FTIR techniques might be used to detect crop diseases.

  6. Metamaterial Absorbers in Terahertz Band

    Institute of Scientific and Technical Information of China (English)

    Qi-Ye Wen; Huai-Wu Zhang; Qing-Hui Yang; Man-Man Mo

    2013-01-01

    In recent years, a great deal of effort has been made to a create terahertz (THz) wave absorber based on metamaterials (MM). Metamaterials absorbers have a variety of potential applications including thermal emitters, detector, stealth technology, phase imaging, etc. In this paper, we firstly introduce the basic structure and work principle of the THz MM absorbers, and a transmission line model is developed for devices analysis. To expand the application of THz absorbers, dual-band and broadband THz MM absorbers are designed, fabricated, and measured. At the end of this article, the future development trends of MM absorbers are discussed.

  7. Bonds and bands in semiconductors

    CERN Document Server

    Phillips, Jim

    2009-01-01

    This classic work on the basic chemistry and solid state physics of semiconducting materials is now updated and improved with new chapters on crystalline and amorphous semiconductors. Written by two of the world's pioneering materials scientists in the development of semiconductors, this work offers in a single-volume an authoritative treatment for the learning and understanding of what makes perhaps the world's most important engineered materials actually work. Readers will find: --' The essential principles of chemical bonding, electron energy bands and their relationship to conductive and s

  8. Evidence for active galactic nucleus feedback in the broad absorption lines and reddening of MRK 231 {sup ,}

    Energy Technology Data Exchange (ETDEWEB)

    Leighly, Karen M.; Baron, Eddie; Lucy, Adrian B. [Homer L. Dodge Department of Physics and Astronomy, The University of Oklahoma, 440 West Brooks Street, Norman, OK 73019 (United States); Terndrup, Donald M. [Department of Astronomy, The Ohio State University, 140 West 18th Avenue, Columbus, OH 43210 (United States); Dietrich, Matthias [Department of Physics and Astronomy, Ohio University, Clippinger Labs 251B, Athens, OH 45701 (United States); Gallagher, Sarah C. [Department of Physics and Astronomy, The University of Western Ontario, London, ON, N6A 3K7 (Canada)

    2014-06-20

    We present the first J-band spectrum of Mrk 231, which reveals a large He I* λ10830 broad absorption line with a profile similar to that of the well-known Na I broad absorption line. Combining this spectrum with optical and UV spectra from the literature, we show that the unusual reddening noted by Veilleux et al. is explained by a reddening curve like those previously used to explain low values of total-to-selective extinction in Type Ia supernovae. The nuclear starburst may be the origin and location of the dust. Spatially resolved emission in the broad absorption line trough suggests nearly full coverage of the continuum emission region. The broad absorption lines reveal higher velocities in the He I* lines (produced in the quasar-photoionized H II region) compared with the Na I and Ca II lines (produced in the corresponding partially ionized zone). Cloudy simulations show that a density increase is required between the H II and partially ionized zones to produce ionic column densities consistent with the optical and IR absorption line measurements and limits, and that the absorber lies ∼100 pc from the central engine. These results suggest that the He I* lines are produced in an ordinary quasar BAL wind that impacts upon, compresses, and accelerates the nuclear starburst's dusty effluent (feedback in action), and the Ca II and Na I lines are produced in this dusty accelerated gas. This unusual circumstance explains the rarity of Na I absorption lines; without the compression along our line of sight, Mrk 231 would appear as an ordinary iron low-ionization, broad absorption line quasar.

  9. Tap Teens' Curiosity with Lab Band.

    Science.gov (United States)

    Saunders, Jane

    2002-01-01

    Describes the Lab Band project used with 12th grade students at the Westgate Collegiate and Vocational Institute in Thunder Bay, Ontario (Canada). Explains that each band student taught a peer how to play their instrument which created versatility in the band. States that all students kept a reflective journal. (CMK)

  10. DUAL-BAND INFRARED DETECTORS

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    As the infrared technology continues to advance, there is a growing demand for multispectral detectors for advanced IR systems with better target discrimination and identification. Both HgCdTe detectors and quantum well GaAs/AlGaAs photodetectors offer wavelength flexibility from medium wavelength to very long wavelength and multicolor capability in these regions. The main challenges facing all multicolor devices are more complicated device structtures, thicker and multilayer material growth, and more difficult device fabrication, especially when the array size gets larger and pixel size gets smaller. In the paper recent progress in development of two-color HgCdTe photodiodes and quantum well infrared photodetectors is presented.More attention is devoted to HgCdTe detectors. The two-color detector arrays are based upon an n-P-N (the capital letters mean the materials with larger bandgap energy) HgCdTe triple layer heterojunction design. Vertically stacking the two p-n junctions permits incorporation of both detectros into a single pixel. Both sequential mode and simultaneous mode detectors are fabricated. The mode of detection is determined by the fabrication process of the multilayer materials.Also the performances of stacked multicolor QWIPs detectors are presented. For multicolor arrays, QWIP's narrow band spectrum is an advantage, resulting in low spectral crosstalk. The major challenge for QWIP is developing broadband or multicolor optical coupling structures that permit efficient absorption of all required spectral bands.

  11. Empirical determination of the energy band gap narrowing in highly doped n+ silicon

    Science.gov (United States)

    Yan, Di; Cuevas, Andres

    2013-07-01

    Highly doped regions in silicon devices should be analyzed using Fermi-Dirac statistics, taking into account energy band gap narrowing (BGN). An empirical expression for the BGN as a function of dopant concentration is derived here by matching the modeled and measured thermal recombination current densities J0 of a broad range of n+ dopant concentration profiles prepared by phosphorus diffusion. The analysis is repeated with Boltzmann statistics in order to determine a second empirical expression for the apparent energy band gap narrowing, which is found to be in good agreement with previous work.

  12. Band offsets at the crystalline / hydrogenated amorphous silicon interface from first-principles

    Science.gov (United States)

    Hazrati, Ebrahim; Jarolimek, Karol; de Wijs, Gilles A.; InstituteMolecules; Materials Team

    2015-03-01

    The heterojunction formed between crystalline silicon (c-Si) and hydrogenated amorphous silicon (a-Si:H) is a key component of a new type of high-efficiency silicon solar cell. Since a-Si:H has a larger band gap than c-Si, band offsets are formed at the interface. A band offset at the minority carrier band will mitigate recombination and lead to an increased efficiency. Experimental values of band offsets scatter in a broad range. However, a recent meta-analysis of the results (W. van Sark et al.pp. 405, Springer 2012) gives a larger valence offset (0.40 eV) than the conduction offset (0.15 eV). In light of the conflicting reports our goal is to calculate the band offsets at the c-Si/a-Si:H interface from first-principles. We have prepared several atomistic models of the interface. The crystalline part is terminated with (111) surfaces on both sides. The amorphous structure is generated by simulating an annealing process at 1100 K, with DFT molecular dynamics. Once the atomistic is ready it can be used to calculate the electronic structure of the interface. Our preliminary results show that the valence offset is larger than the conduction band offset.

  13. Synthesis and Characterization of ZnS:Eu3+ - CMC nanophosphors emitting white light over broad excitation range

    Science.gov (United States)

    de, Dilip; Ahemen, Ikorya; Bruno, Viena

    In this paper we report for the first time the synthesis and characterization of nanophosphors of ZnS:Eu3+ - embedded in sodium carboxymethyl cellulose matrix (CMC) that emits high quality white light over broad range of excitation. The nano-phosphors of cubic (zinc blende) structure were synthesized using precipitation technique with doping concentrations of Eu3+ ions 1 mol% and 5 mol%. The crystal sizes were 2.56 nm and 2.91 nm respectively. Annealing at 300 oC in a sulfur-rich atmosphere altered the crystal size to 4.35 nm and 3.65 nm respectively and the band gap from 4.2 eV to 3.76 eV and 3.81 eV respectively. The as-synthesized samples gave pure orange-red emission when excited at wavelengths of 394 nm and 465 nm. After thermal annealing of the samples, a broad emission band in the blue-green region assigned to defect related states emerged or were enhanced. Also enhanced were the emission lines of Eu3+ ions in the orange-red region. A combination of these two transitions gave white light of different shades (recorded on the CIE 1931 chromaticity diagram) from cool white through Day-light to warm white light, depending on Eu3+ concentration and the excitation wavelengths (UV-330 to blue 465 nm), thus showing great potential applications of these nano-phosphors.

  14. THE DIFFERENCES IN THE TORUS GEOMETRY BETWEEN HIDDEN AND NON-HIDDEN BROAD LINE ACTIVE GALACTIC NUCLEI

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, Kohei; Ueda, Yoshihiro [Department of Astronomy, Kyoto University, Kitashirakawa-Oiwake-cho, Sakyo-ku, Kyoto 606-8502 (Japan); Packham, Christopher; Lopez-Rodriguez, Enrique; Alsip, Crystal D. [Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249 (United States); Almeida, Cristina Ramos; Ramos, Andrés Asensio; González-Martín, Omaira [Instituto de Astrofísica de Canarias, C/Vía Láctea, s/n, E-38205 La Laguna, Tenerife (Spain); Alonso-Herrero, Almudena [Instituto de Física de Cantabria, CSIC-Universidad de Cantabria, E-39005 Santander (Spain); Díaz-Santos, Tanio [Spitzer Science Center, California Institute of Technology, MS 220-6, Pasadena, CA 91125 (United States); Elitzur, Moshe [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506-0055 (United States); Hönig, Sebastian F. [School of Physics and Astronomy, University of Southampton, Southampton SO17 1BJ (United Kingdom); Imanishi, Masatoshi [Subaru Telescope, 650 North A’ohoku Place, Hilo, HI 96720 (United States); Levenson, Nancy A. [Gemini Observatory, Southern Operations Center, c/o AURA, Casilla 603, La Serena (Chile); Mason, Rachel E. [Gemini Observatory, Northern Operations Center, 670 N. A’ohoku Place, Hilo, HI 96720 (United States); Perlman, Eric S., E-mail: ichikawa@kusastro.kyoto-u.ac.jp [Department of Physics and Space Sciences, 150 W. University Blvd., Florida Institute of Technology, Melbourne, FL 32901 (United States)

    2015-04-20

    We present results from the fitting of infrared (IR) spectral energy distributions of 21 active galactic nuclei (AGNs) with clumpy torus models. We compiled high spatial resolution (∼0.3–0.7 arcsec) mid-IR (MIR) N-band spectroscopy, Q-band imaging, and nuclear near- and MIR photometry from the literature. Combining these nuclear near- and MIR observations, far-IR photometry, and clumpy torus models enables us to put constraints on the torus properties and geometry. We divide the sample into three types according to the broad line region (BLR) properties: type-1s, type-2s with scattered or hidden broad line region (HBLR) previously observed, and type-2s without any published HBLR signature (NHBLR). Comparing the torus model parameters gives us the first quantitative torus geometrical view for each subgroup. We find that NHBLR AGNs have smaller torus opening angles and larger covering factors than HBLR AGNs. This suggests that the chance to observe scattered (polarized) flux from the BLR in NHBLR could be reduced by the dual effects of (a) less scattering medium due to the reduced scattering volume given the small torus opening angle and (b) the increased torus obscuration between the observer and the scattering region. These effects give a reasonable explanation for the lack of observed HBLR in some type-2 AGNs.

  15. The complex circumnuclear environment of the broad-line radio galaxy 3C 390.3 revealed by Chandra HETG

    CERN Document Server

    Tombesi, F; Kallman, T; Reynolds, C S; Mushotzky, R F; Braito, V; Behar, E; Leutenegger, M A; Cappi, M

    2016-01-01

    We present the first high spectral resolution X-ray observation of the broad-line radio galaxy 3C 390.3 obtained with the high energy transmission grating (HETG) spectrometer on board the Chandra X-ray Observatory. The spectrum shows complex emission and absorption features in both the soft X-rays and Fe K band. We detect emission and absorption lines in the energy range between E = 700-1000 eV associated with ionized Fe L transitions (Fe XVII-XX). An emission line at the energy of E=6.4 keV consistent with the Fe K\\alpha is also observed. Our best-fit model requires at least three different components: (i) a hot emission component likely associated with the hot interstellar medium in this elliptical galaxy with temperature kT=0.5+/-0.1 keV; (ii) a warm absorber with ionization parameter log\\xi=2.3+/-0.5 erg s^{-1} cm, column density logN_H=20.7+/-0.1 cm^{-2}, and outflow velocity of v_{out}<150 km s^{-1}; (iii) a lowly ionized reflection component in the Fe K band likely associated with the optical broad ...

  16. Iliotibial band syndrome: evaluation and management.

    Science.gov (United States)

    Strauss, Eric J; Kim, Suezie; Calcei, Jacob G; Park, Daniel

    2011-12-01

    Iliotibial band syndrome is a common overuse injury typically seen in runners, cyclists, and military recruits. Affected patients report lateral knee pain associated with repetitive motion activities. The diagnosis is usually made based on a characteristic history and physical examination, with imaging studies reserved for cases of recalcitrant disease to rule out other pathologic entities. Several etiologies have been proposed for iliotibial band syndrome, including friction of the iliotibial band against the lateral femoral epicondyle, compression of the fat and connective tissue deep to the iliotibial band, and chronic inflammation of the iliotibial band bursa. The mainstay of treatment is nonsurgical; however, in persistent or chronic cases, surgical management is indicated.

  17. Evolutions of Compaction Bands of Saturated Soils

    Institute of Scientific and Technical Information of China (English)

    鲁晓兵; 王义华; 崔鹏

    2004-01-01

    The development of compaction bands in saturated soils, which is coupling-rate, inertial and pore-pressure-dependent, under axisymmetric loading was discussed, using a simple model and a matching technique at the moving boundary of a band. It is shown that the development of compaction bands is dominated by the coupling-rate and pore-pressure effects of material. The soil strength makes the band shrinking, whilst pore pressure diffusion makes the band expand. Numerical simulations were carried out in this paper.

  18. Multitemporal spectroscopy for crop stress detection using band selection methods

    Science.gov (United States)

    Mewes, Thorsten; Franke, Jonas; Menz, Gunter

    2008-08-01

    A fast and precise sensor-based identification of pathogen infestations in wheat stands is essential for the implementation of site-specific fungicide applications. Several works have shown possibilities and limitations for the detection of plant stress using spectral sensor data. Hyperspectral data provide the opportunity to collect spectral reflectance in contiguous bands over a broad range of the electromagnetic spectrum. Individual phenomena like the light absorption of leaf pigments can be examined in detail. The precise knowledge of stress-dependent shifting in certain spectral wavelengths provides great advantages in detecting fungal infections. This study focuses on band selection techniques for hyperspectral data to identify relevant and redundant information in spectra regarding a detection of plant stress caused by pathogens. In a laboratory experiment, five 1 sqm boxes with wheat were multitemporarily measured by a ASD Fieldspec® 3 FR spectroradiometer. Two stands were inoculated with Blumeria graminis - the pathogen causing powdery mildew - and one stand was used to simulate the effect of water deficiency. Two stands were kept healthy as control stands. Daily measurements of the spectral reflectance were taken over a 14-day period. Three ASD Pro Lamps were used to illuminate the plots with constant light. By applying band selection techniques, the three types of different wheat vitality could be accurately differentiated at certain stages. Hyperspectral data can provide precise information about pathogen infestations. The reduction of the spectral dimension of sensor data by means of band selection procedures is an appropriate method to speed up the data supply for precision agriculture.

  19. Inter-Band Radiometric Comparison and Calibration of ASTER Visible and Near-Infrared Bands

    Directory of Open Access Journals (Sweden)

    Kenta Obata

    2015-11-01

    Full Text Available The present study evaluates inter-band radiometric consistency across the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER visible and near-infrared (VNIR bands and develops an inter-band calibration algorithm to improve radiometric consistency. Inter-band radiometric comparison of current ASTER data shows a root mean square error (RMSE of 3.8%–5.7% among radiance outputs of spectral bands due primarily to differences between calibration strategies of the NIR band for nadir-looking (Band 3N and the other two bands (green and red bands, corresponding to Bands 1 and 2. An algorithm for radiometric calibration of Bands 2 and 3N with reference to Band 1 is developed based on the band translation technique and is used to obtain new radiometric calibration coefficients (RCCs for sensor sensitivity degradation. The systematic errors between radiance outputs are decreased by applying the derived RCCs, which result in reducing the RMSE from 3.8%–5.7% to 2.2%–2.9%. The remaining errors are approximately equal to or smaller than the intrinsic uncertainties of inter-band calibration derived by sensitivity analysis. Improvement of the radiometric consistency would increase the accuracy of band algebra (e.g., vegetation indices and its application. The algorithm can be used to evaluate inter-band radiometric consistency, as well as for the calibration of other sensors.

  20. 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).

  1. A simple disc wind model for broad absorption line quasars

    Science.gov (United States)

    Higginbottom, N.; Knigge, C.; Long, K. S.; Sim, S. A.; Matthews, J. H.

    2013-12-01

    Approximately 20 per cent of quasi-stellar objects (QSOs) exhibit broad, blue-shifted absorption lines in their ultraviolet spectra. Such features provide clear evidence for significant outflows from these systems, most likely in the form of accretion disc winds. These winds may represent the `quasar' mode of feedback that is often invoked in galaxy formation/evolution models, and they are also key to unification scenarios for active galactic nuclei (AGN) and QSOs. To test these ideas, we construct a simple benchmark model of an equatorial, biconical accretion disc wind in a QSO and use a Monte Carlo ionization/radiative transfer code to calculate the ultraviolet spectra as a function of viewing angle. We find that for plausible outflow parameters, sightlines looking directly into the wind cone do produce broad, blue-shifted absorption features in the transitions typically seen in broad absorption line (BAL) QSOs. However, our benchmark model is intrinsically X-ray weak in order to prevent overionization of the outflow, and the wind does not yet produce collisionally excited line emission at the level observed in non-BAL QSOs. As a first step towards addressing these shortcomings, we discuss the sensitivity of our results to changes in the assumed X-ray luminosity and mass-loss rate, Ṁwind. In the context of our adopted geometry, Ṁwind ˜ Ṁacc is required in order to produce significant BAL features. The kinetic luminosity and momentum carried by such outflows would be sufficient to provide significant feedback.

  2. New focal plane detector system for the broad range spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Sjoreen, T.P.

    1984-01-01

    A focal plane detector system consisting of a vertical drift chamber, parallel plate avalanche counters, and an ionization chamber with segmented anodes has been installed in the Broad Range Spectrometer at the Holifield Facility at Oak Ridge. The system, which has been designed for use with light-heavy ions with energies ranging from 10 to 25 MeV/amu, has a position resolution of approx. 0.1 mm, a scattering angle resolution of approx. 3 mrad, and a mass resolution of approx. 1/60.

  3. VLBA imaging of radio-loud Broad Absorption Line QSOs

    CERN Document Server

    Montenegro-Montes, F M; Benn, C R; Carballo, R; Dallacasa, D; González-Serrano, J I; Holt, J; Jiménez-Luján, F

    2009-01-01

    Broad Absorption Line Quasars (BAL QSOs) have been found to be associated with extremely compact radio sources. These reduced dimensions can be either due to projection effects or these objects might actually be intrinsically small. Exploring these two hypotheses is important to understand the nature and origin of the BAL phenomenon because orientation effects are an important discriminant between the different models proposed to explain this phenomenon. In this work we present VLBA observations of 5 BAL QSOs and discuss their pc-scale morphology.

  4. Discovery of Balmer broad absorption lines in the quasar LBQS 1206+1052

    Institute of Scientific and Technical Information of China (English)

    Tuo Ji; Ting-Gui Wang; Hong-Yan Zhou; Hui-Yuan Wang

    2012-01-01

    We report the discovery of Balmer broad absorption lines (BALs) in the quasar LBQS 1206+1052 and present a detailed analysis of the peculiar absorption line spectrum.Besides the Mg Ⅱ λλ2796,2803 doublet,BALs are also detected in the He Ⅰ* multiplet at λλ2946,3189,3889(A) arising from the metastable helium 23S level,and in Hα and Hβ from the excited hydrogen H Ⅰ* n =2 level,which are rarely seen in quasar spectra.We identify two components in the BAL troughs of △v ~2000 km s-1 width:One component shows an identical profile in H Ⅰ*,He Ⅰ* and Mg Ⅱ with its centroid blueshifted by —vc ≈ 726 km s-1.The other component is detected in He Ⅰ* and Mg Ⅱ with —vc ≈ 1412 km s-1.We estimate the column densities of H Ⅰ*,He Ⅰ*,and Mg Ⅱ,and compare them with possible level population mechanisms.Our results favor the scenario that the Balrner BALs originate in a partially ionized region with a column density of NH ~ 1021 - 1022 cm-2 for an electron density of ne ~ 106 - 108 cm-3 via Lyα resonant scattering pumping.The harsh conditions needed may help to explain the rarity of Balmer absorption line systems in quasar spectra.With ani-band PSF magnitude of 16.50,LBQS 1206+1052 is the brightest Balmer-BAL quasar ever reported.Its high brightness and unique spectral properties make LBQS 1206+1052 a promising candidate for followup high-resolution spectroscopy,multi-band observations,and long-term monitoring.

  5. Detection of faint broad emission lines in type 2 AGN - I. Near-infrared observations and spectral fitting

    Science.gov (United States)

    Onori, F.; La Franca, F.; Ricci, F.; Brusa, M.; Sani, E.; Maiolino, R.; Bianchi, S.; Bongiorno, A.; Fiore, F.; Marconi, A.; Vignali, C.

    2017-01-01

    We present medium resolution near-infrared spectroscopic observations of 41 obscured and intermediate class active galactic nuclei (AGN; type 2, 1.9 and 1.8; AGN2) with redshift z ≲ 0.1, selected from the Swift/Burst Alert Telescope 70-month catalogue. The observations have been carried out in the framework of a systematic study of the AGN2 near-infrared spectral properties and have been executed using Infrared Spectrometer And Array Camera/VLT, X-shooter/VLT and LUCI/LBT, reaching an average S/N ratio of ˜30 per resolution element. For those objects observed with X-shooter, we also obtained simultaneous optical and UV spectroscopy. We have identified a component from the broad line region in 13 out of 41 AGN2, with full width at half-maximum (FWHM) > 800 km s-1. We have verified that the detection of the broad line region components does not significantly depend on selection effects due to the quality of the spectra, the X-ray or near-infrared fluxes, the orientation angle of the host galaxy or the hydrogen column density measured in the X-ray band. The average broad line region components found in AGN2 has a significantly (a factor 2) smaller FWHM if compared with a control sample of type 1 AGN.

  6. Detection of faint broad emission lines in type 2 AGN: I. Near infrared observations and spectral fitting

    CERN Document Server

    Onori, F; Ricci, F; Brusa, M; Sani, E; Maiolino, R; Bianchi, S; Bongiorno, A; Fiore, F; Marconi, A; Vignali, C

    2016-01-01

    We present medium resolution near infrared spectroscopic observations of 41 obscured and intermediate class AGN (type 2, 1.9 and 1.8; AGN2) with redshift $z \\lesssim$0.1, selected from the Swift/BAT 70-month catalogue. The observations have been carried out in the framework of a systematic study of the AGN2 near infrared spectral properties and have been executed using ISAAC/VLT, X-shooter/VLT and LUCI/LBT, reaching an average S/N ratio of $\\sim$30 per resolution element. For those objects observed with X-shooter we also obtained simultaneous optical and UV spectroscopy. We have identified a component from the broad line region in 13 out of 41 AGN2, with FWHM ${\\rm > 800 }$ km/s. We have verified that the detection of the broad line region components does not significantly depend on selection effects due to the quality of the spectra, the X-ray or near infrared fluxes, the orientation angle of the host galaxy or the hydrogen column density measured in the X-ray band. The average broad line region components f...

  7. Weak-Line Quasars at High Redshift: Extremely High Accretion Rates or Anemic Broad-Line Regions?

    CERN Document Server

    Shemmer, Ohad; Anderson, Scott F; Brandt, W N; Diamond-Stanic, Aleksandar M; Fan, Xiaohui; Lira, Paulina; Netzer, Hagai; Plotkin, Richard M; Richards, Gordon T; Schneider, Donald P; Strauss, Michael A

    2010-01-01

    We present Gemini-North K-band spectra of two representative members of the class of high-redshift quasars with exceptionally weak rest-frame ultraviolet emission lines (WLQs), SDSS J114153.34+021924.3 at z=3.55 and SDSS J123743.08+630144.9 at z=3.49. In both sources we detect an unusually weak broad H_beta line and we place tight upper limits on the strengths of their [O III] lines. Virial, H_beta-based black-hole mass determinations indicate normalized accretion rates of L/L_Edd=0.4 for these sources, which is well within the range observed for typical quasars with similar luminosities and redshifts. We also present high-quality XMM-Newton imaging spectroscopy of SDSS J114153.34+021924.3 and find a hard-X-ray photon index of Gamma=1.91^{+0.24}_{-0.22} which supports the virial L/L_Edd determination in this source. Our results suggest that the weakness of the broad-emission lines in WLQs is not a consequence of an extreme continuum-emission source but instead due to abnormal broad-emission line region proper...

  8. Detection of faint broad emission lines in type 2 AGN: I. Near infrared observations and spectral fitting

    Science.gov (United States)

    Onori, F.; La Franca, F.; Ricci, F.; Brusa, M.; Sani, E.; Maiolino, R.; Bianchi, S.; Bongiorno, A.; Fiore, F.; Marconi, A.; Vignali, C.

    2016-09-01

    We present medium resolution near infrared spectroscopic observations of 41 obscured and intermediate class AGN (type 2, 1.9 and 1.8; AGN2) with redshift z ≲0.1, selected from the Swift/BAT 70-month catalogue. The observations have been carried out in the framework of a systematic study of the AGN2 near infrared spectral properties and have been executed using ISAAC/VLT, X-shooter/VLT and LUCI/LBT, reaching an average S/N ratio of ˜30 per resolution element. For those objects observed with X-shooter we also obtained simultaneous optical and UV spectroscopy. We have identified a component from the broad line region in 13 out of 41 AGN2, with FWHM >800 km s-1. We have verified that the detection of the broad line region components does not significantly depend on selection effects due to the quality of the spectra, the X-ray or near infrared fluxes, the orientation angle of the host galaxy or the hydrogen column density measured in the X-ray band. The average broad line region components found in AGN2 has a significantly (a factor 2) smaller FWHM if compared with a control sample of type 1 AGN.

  9. Giemsa C-banding of Barley Chromosomes. I: Banding Pattern Polymorphism

    DEFF Research Database (Denmark)

    Linde-Laursen, Ib

    1978-01-01

    Twenty barley (Hordeum vulgare) lines studied had a common basic chromosome banding pattern. Most bands ranged from medium to very small in size. The most conspicuous banding occurred at or near the centromeres, in the proximal, intercalary parts of most chromosome arms and beside the secondary c...... 7. Seventeen differently banded karyotypes were found. Some banding pattern polymorphisms can be used in cytological and cytogenetic studies....

  10. Spatial and Temporal Evolution of Ultra-Wide-Band Optical Pulses in Propagation

    Institute of Scientific and Technical Information of China (English)

    XU Jing-Zhou; WANG Li; YANG Guo-Zhen

    2000-01-01

    The propagation of ultrashort coherent electromagnetic pulses with broad spectral bandwidth in free space is studied by using scalar diffraction theory. It is confirmed and experimentally demonstrated that the diffraction not only affects the spatial structure but also changes the temporal waveform of an ultra-wide-band pulse during propagation. The terahertz pulse travelling as basic mode of Gaussian beam is discussed in detail

  11. Multivalent dendritic molecules as broad spectrum bacteria agglutination agents.

    Science.gov (United States)

    Xiao, Shuzhang; Abu-Esba, Lica; Turkyilmaz, Serhan; White, Alexander G; Smith, Bradley D

    2013-01-01

    This study reports the first set of synthetic molecules that act as broad spectrum agglutination agents and thus are complementary to the specific targeting of antibodies. The molecules have dendritic architecture and contain multiple copies of zinc(II)-dipicolylamine (ZnDPA) units that have selective affinity for the bacterial cell envelope. A series of molecular structures were evaluated, with the number of appended ZnDPA units ranging from four to thirty-two. Agglutination assays showed that the multivalent probes rapidly cross-linked ten different strains of bacteria, regardless of Gram-type and cell morphology. Fluorescence microscopy studies using probes with four ZnDPA units indicated a high selectivity for bacteria agglutination in the presence of mammalian cells and no measurable effect on the health of the cells. The high bacterial selectivity was confirmed by conducting in vivo optical imaging studies of a mouse leg infection model. The results suggest that multivalent ZnDPA molecular probes with dendritic structures have great promise as selective, broad spectrum bacterial agglutination agents for infection imaging and theranostic applications.

  12. Broad Ly alpha Emission from Three Nearby BL Lacertae Objects

    CERN Document Server

    Stocke, John T; Perlman, Eric S

    2011-01-01

    We present far-UV HST/COS spectra of four nearby BL Lac Objects. BL Lac spectra are dominated by a smooth, power-law continuum which arises in a relativistic jet. However, the spectra are not necessarily featureless; weak, broad- and/or narrow-line emission is sometimes seen in high-quality optical spectra. We present detections of Lya emission in HST/COS spectra of Mrk421 (z=0.030) and PKS2005-489 (z=0.071) as well as an archival HST/GHRS observation of Mrk501 (z=0.0337). Archival HST/STIS observations of PKS2155-304 (z=0.116) show no Lya emission to a very low upper limit. Using the assumption that the broad-line region (BLR) clouds are asymmetrically placed around the AGN, we use these measured Lya emission features to constrain either the relativistic Gamma values for the ionizing continuum produced by the jet (in the ionization-bounded case) or the mass of warm gas (in the density-bounded case). While realistic Gamma values can be obtained for all four cases, the values for Mrk421 and PKS2155-304 are hig...

  13. Broad spectrum microarray for fingerprint-based bacterial species identification

    Directory of Open Access Journals (Sweden)

    Frey Jürg E

    2010-02-01

    Full Text Available Abstract Background Microarrays are powerful tools for DNA-based molecular diagnostics and identification of pathogens. Most target a limited range of organisms and are based on only one or a very few genes for specific identification. Such microarrays are limited to organisms for which specific probes are available, and often have difficulty discriminating closely related taxa. We have developed an alternative broad-spectrum microarray that employs hybridisation fingerprints generated by high-density anonymous markers distributed over the entire genome for identification based on comparison to a reference database. Results A high-density microarray carrying 95,000 unique 13-mer probes was designed. Optimized methods were developed to deliver reproducible hybridisation patterns that enabled confident discrimination of bacteria at the species, subspecies, and strain levels. High correlation coefficients were achieved between replicates. A sub-selection of 12,071 probes, determined by ANOVA and class prediction analysis, enabled the discrimination of all samples in our panel. Mismatch probe hybridisation was observed but was found to have no effect on the discriminatory capacity of our system. Conclusions These results indicate the potential of our genome chip for reliable identification of a wide range of bacterial taxa at the subspecies level without laborious prior sequencing and probe design. With its high resolution capacity, our proof-of-principle chip demonstrates great potential as a tool for molecular diagnostics of broad taxonomic groups.

  14. Peculiar Broad Absorption Line Quasars found in DPOSS

    CERN Document Server

    Brunner, R J; Djorgovski, S G; Gal, R R; Mahabal, A A; Lopes, P A A; De Carvalho, R R; Odewahn, S C; Castro, S; Thompson, D; Chaffee, F; Darling, J; Desai, V; Brunner, Robert J.; Hall, Patrick B.

    2003-01-01

    With the recent release of large (i.e., > hundred million objects), well-calibrated photometric surveys, such as DPOSS, 2MASS, and SDSS, spectroscopic identification of important targets is no longer a simple issue. In order to enhance the returns from a spectroscopic survey, candidate sources are often preferentially selected to be of interest, such as brown dwarfs or high redshift quasars. This approach, while useful for targeted projects, risks missing new or unusual species. We have, as a result, taken the alternative path of spectroscopically identifying interesting sources with the sole criterion being that they are in low density areas of the g - r and r - i color-space defined by the DPOSS survey. In this paper, we present three peculiar broad absorption line quasars that were discovered during this spectroscopic survey, demonstrating the efficacy of this approach. PSS J0052+2405 is an Iron LoBAL quasar at a redshift z = 2.4512 with very broad absorption from many species. PSS J0141+3334 is a reddened...

  15. Outflow and hot dust emission in broad absorption line quasars

    CERN Document Server

    Zhang, Shaohua; Wang, Tinggui; Xing, Feijun; Zhang, Kai; Zhou, Hongyan; Jiang, Peng

    2014-01-01

    We have investigated a sample of 2099 broad absorption line (BAL) quasars with z=1.7-2.2 built from the Sloan Digital Sky Survey Data Release Seven and the Wide-field Infrared Survey. This sample is collected from two BAL quasar samples in the literature, and refined by our new algorithm. Correlations of outflow velocity and strength with hot dust indicator (beta_NIR) and other quasar physical parameters, such as Eddington ratio, luminosity and UV continuum slope, are explored in order to figure out which parameters drive outflows. Here beta_NIR is the near-infrared continuum slope, a good indicator of the amount of hot dust emission relative to accretion disk emission. We confirm previous findings that outflow properties moderately or weakly depends on Eddington ratio, UV slope and luminosity. For the first time, we report moderate and significant correlations of outflow strength and velocity with beta_NIR in BAL quasars. It is consistent with the behavior of blueshifted broad emission lines in non-BAL quasa...

  16. Broad-spectrum antimicrobial polycarbonate hydrogels with fast degradability.

    Science.gov (United States)

    Pascual, Ana; Tan, Jeremy P K; Yuen, Alex; Chan, Julian M W; Coady, Daniel J; Mecerreyes, David; Hedrick, James L; Yang, Yi Yan; Sardon, Haritz

    2015-04-13

    In this study, a new family of broad-spectrum antimicrobial polycarbonate hydrogels has been successfully synthesized and characterized. Tertiary amine-containing eight-membered monofunctional and difunctional cyclic carbonates were synthesized, and chemically cross-linked polycarbonate hydrogels were obtained by copolymerizing these monomers with a poly(ethylene glycol)-based bifunctional initiator via organocatalyzed ring-opening polymerization using 1,8-diazabicyclo[5.4.0]undec-7-ene catalyst. The gels were quaternized using methyl iodide to confer antimicrobial properties. Stable hydrogels were obtained only when the bifunctional monomer concentration was equal to or higher than 12 mol %. In vitro antimicrobial studies revealed that all quaternized hydrogels exhibited broad-spectrum antimicrobial activity against Staphylococcus aureus (Gram-positive), Escherichia coli (Gram-negative), Pseudomonas aeruginosa (Gram-negative), and Candida albicans (fungus), while the antimicrobial activity of the nonquaternized hydrogels was negligible. Moreover, the gels showed fast degradation at room temperature (4-6 days), which makes them ideal candidates for wound healing and implantable biomaterials.

  17. More Is Better: Selecting for Broad Host Range Bacteriophages.

    Science.gov (United States)

    Ross, Alexa; Ward, Samantha; Hyman, Paul

    2016-01-01

    Bacteriophages are viruses that infect bacteria. In this perspective, we discuss several aspects of a characteristic feature of bacteriophages, their host range. Each phage has its own particular host range, the range of bacteria that it can infect. While some phages can only infect one or a few bacterial strains, other phages can infect many species or even bacteria from different genera. Different methods for determining host range may give different results, reflecting the multiple mechanisms bacteria have to resist phage infection and reflecting the different steps of infection each method depends on. This makes defining host range difficult. Another difficulty in describing host range arises from the inconsistent use of the words "narrow" and especially "broad" when describing the breadth of the host range. Nearly all bacteriophages have been isolated using a single host strain of bacteria. While this procedure is fairly standard, it may more likely produce narrow rather than broad host range phage. Our results and those of others suggest that using multiple host strains during isolation can more reliably produce broader host range phages. This challenges the common belief that most bacteriophages have a narrow host range. We highlight the implications of this for several areas that are affected by host range including horizontal gene transfer and phage therapy.

  18. The UV-Optical Albedo of Broad Emission Line Clouds

    CERN Document Server

    Korista, K T; Korista, Kirk; Ferland, Gary

    1997-01-01

    We explore the effective UV-optical albedos of a variety of types of broad emission line clouds, as well as their possible effects on the observed spectra of AGN. An important albedo source in moderately ionized ionization-bounded clouds is that due to neutral hydrogen: Rayleigh scattering of continuum photons off the extreme damping wings of Lya. The photons resulting from this scattering mechanism may contribute significantly to the Lya emission line, especially in the very broad wings. In addition, line photons emitted near 1200 Angstroms (e.g., N V 1240) that stream toward the neutral portion of the cloud may be reflected off this Rayleigh scattering mirror, so that they preferentially escape from the illuminated face. Inclusion of this effect can alter predicted emission line strengths and profiles. In more highly-ionized ionization-bounded clouds, Thompson scattering dominates the UV-optical albedo, but this albedo is lessened by the hydrogen gas opacity. These clouds are most reflective on the long wav...

  19. Effect of gamma irradiation on antinutritional factors in broad bean

    Energy Technology Data Exchange (ETDEWEB)

    Al-Kaisey, M.T. E-mail: istd@uruklink.net; Alwan, A.-K.H.; Mohammad, M.H.; Saeed, A.H

    2003-06-01

    The effect of gamma irradiation on the level of antinutritional factors (trypsin inhibitor (TI), phytic acid and oligosaccharides) of broad bean was investigated. The seeds were subjected to gamma irradiation at 0, 2.5, 5, 7.5 and 10 kGy, respectively using cobalt-60 gamma radiation with a dose rate 2.37 kGy/h. TI activity was reduced by 4.5%, 6.7%, 8.5% and 9.2% at 2.5, 5, 7.5 and 10 kGy, respectively. Meanwhile, irradiation at 10.2, 12.3, 15.4 and 18.2 kGy reduced the phytic acid content. The flatulence causing oligosaccharides were decreased as the radiation dose increased. The chemical composition (protein, oil, ash and total carbohydrates) of the tested seeds was determined. Gamma radiation seems to be a good procedure to improve the quality of broad bean from the nutritional point of view.

  20. Communicating Science Broadly: An NSF Point of View

    Science.gov (United States)

    Leinen, M. S.

    2006-12-01

    In the view of NSF, communicating about both the process of doing science and about scientific results are of paramount importance. But those of us in the agency are not the ones who do the science or generate the results. Thus, our policy is to encourage the community we fund to communicate their results as broadly as possible. Why does NSF feel so strongly about communicating scientific results? First, science only moves forward when there is free and open debate about scientific results through public mechanisms in which there is an opportunity for thorough analysis (e.g. scientific literature, professional meetings and workshops). Second, the research we support is done for the good of the public and should be communicated to the public. Third, scientific results are critical to many important decision-making processes and policy-making processes. Democracies thrive when an informed public is engaged, so communicating science broadly to the lay public is important. Why does NSF feel so strongly about communicating about the process of science? Science is a habit of mind; an orderly process for testing ideas. But many do not understand how science is done, the difference between fact and conjecture, why speculation, hypotheses and theory are critical to progress, or why the culture of constructive criticism is essential to progress. Without this context, science can be misunderstood as magic, opinion, or argument. Thus the efforts that we fund to enhance scientific education and outreach are critical to having discourse about scientific results.

  1. The response of rodents to scent marks: four broad hypotheses.

    Science.gov (United States)

    Ferkin, Michael H

    2015-02-01

    This article is part of a Special Issue "Chemosignals and Reproduction". Many terrestrial mammals must be able to distinguish between the myriad of scent marks they encounter in order for them to facilitate or deter direct interactions with their scent donors. I review studies that examine how rodents, mainly meadow voles (Microtus pennsylvanicus), respond when they encounter the scent marks of conspecifics and heterospecifics, and how context, as well as the age and condition of senders and receivers, affect their responses. The review uses four broad hypotheses to discuss the response of rodents to scent marks. The four hypotheses are as follows: 1) Scent marks convey accurate information to the receiver about the sender's state and phenotype and genotype. 2) Scent marks are individually distinct. 3) The response of receivers to scent marks is flexible and would be modulated by the cognitive abilities of receivers. 4) Receivers respond to the information contained or conveyed by the scent mark in a manner that will increase their survival and fitness. The studies cited in this review show that scent marks signal accurate information about the sender's phenotype, genotype, and condition, which receivers use to distinguish among the scent marks of different conspecifics and heterospecifics, and by doing so, receivers tailor their response accordingly to increase their survival and fitness. Thus, the four broad hypotheses may serve as guide to increase our understanding of the response of receivers to scent marks and provide a conceptual framework for future research and the development of additional hypotheses.

  2. Amorphous oxide alloys as interfacial layers with broadly tunable electronic structures for organic photovoltaic cells.

    Science.gov (United States)

    Zhou, Nanjia; Kim, Myung-Gil; Loser, Stephen; Smith, Jeremy; Yoshida, Hiroyuki; Guo, Xugang; Song, Charles; Jin, Hosub; Chen, Zhihua; Yoon, Seok Min; Freeman, Arthur J; Chang, Robert P H; Facchetti, Antonio; Marks, Tobin J

    2015-06-30

    In diverse classes of organic optoelectronic devices, controlling charge injection, extraction, and blocking across organic semiconductor-inorganic electrode interfaces is crucial for enhancing quantum efficiency and output voltage. To this end, the strategy of inserting engineered interfacial layers (IFLs) between electrical contacts and organic semiconductors has significantly advanced organic light-emitting diode and organic thin film transistor performance. For organic photovoltaic (OPV) devices, an electronically flexible IFL design strategy to incrementally tune energy level matching between the inorganic electrode system and the organic photoactive components without varying the surface chemistry would permit OPV cells to adapt to ever-changing generations of photoactive materials. Here we report the implementation of chemically/environmentally robust, low-temperature solution-processed amorphous transparent semiconducting oxide alloys, In-Ga-O and Ga-Zn-Sn-O, as IFLs for inverted OPVs. Continuous variation of the IFL compositions tunes the conduction band minima over a broad range, affording optimized OPV power conversion efficiencies for multiple classes of organic active layer materials and establishing clear correlations between IFL/photoactive layer energetics and device performance.

  3. The role of the pupal determinant broad during embryonic development of a direct-developing insect

    Science.gov (United States)

    Rynerson, Melody R.; Truman, James W.; Riddiford, Lynn M.

    2010-01-01

    Metamorphosis is one of the most common, yet dramatic of life history strategies. In insects, complete metamorphosis with morphologically distinct larval stages arose from hemimetabolous ancestors that were more direct developing. Over the past century, several ideas have emerged that suggest the holometabolous pupa is developmentally homologous to the embryonic stages of the hemimetabolous ancestor. Other theories consider the pupal stage to be a modification of a hemimetabolous nymph. To address this question, we have isolated an ortholog of the pupal determinant, broad (br), from the hemimetabolous milkweed bug and examined its role during embryonic development. We show that Oncopeltus fasciatus br (Of'br) is expressed in two phases. The first occurs during germ band invagination and segmentation when Of'br is expressed ubiquitously in the embryonic tissues. The second phase of Of'br expression appears during the pronymphal phase of embryogenesis and persists through nymphal differentiation to decline just before hatching. Knock-down of Of'br transcripts results in defects that range from posterior truncations in the least-affected phenotypes to completely fragmented embryonic tissues in the most severe cases. Analysis of the patterning genes engrailed and hunchback reveal loss of segments and a failure in neural differentiation after Of'br depletion. Finally, we show that br is constitutively expressed during embyrogenesis of the ametabolous firebrat, Thermobia domestica. This suggests that br expression is prominent during embryonic development of ametabolous and hemimetabolous insects but was lost with the emergence of the completely metamorphosing insects. PMID:20127251

  4. The Corona of the Broad-Line Radio Galaxy 3C 390.3

    CERN Document Server

    Lohfink, Anne; Tombesi, Francesco; Walton, Dominic; Balokovic, Mislav; Zoghbi, Abdu; Ballantyne, David; Boggs, Steven; Christensen, Finn; Craig, William; Fabian, Andrew; Hailey, Charles; Harrison, Fiona; King, Ashley; Madejski, Greg; Matt, Giorgio; Reynolds, Christopher; Stern, Daniel; Ursini, Francesco; Zhang, William

    2015-01-01

    We present the results from a joint Suzaku/NuSTAR broad-band spectral analysis of 3C 390.3. The high quality data enables us to clearly separate the primary continuum from the reprocessed components allowing us to detect a high energy spectral cut-off ($E_\\text{cut}=117_{-14}^{+18}$ keV), and to place constraints on the Comptonization parameters of the primary continuum for the first time. The hard over soft compactness is 69$_{-24}^{+124}$ and the optical depth 4.1$_{-3.6}^{+0.5}$, this leads to an electron temperature of $30_{-8}^{+32}$ keV. Expanding our study of the Comptonization spectrum to the optical/UV by studying the simultaneous Swift-UVOT data, we find indications that the compactness of the corona allows only a small fraction of the total UV/optical flux to be Comptonized. Our analysis of the reprocessed emission show that 3C 390.3 only has a small amount of reflection (R~0.3), and of that the vast majority is from distant neutral matter. However we also discover a soft X-ray excess in the source...

  5. The High Energy view of the Broad Line Radio Galaxy 3C 111

    CERN Document Server

    Ballo, L; Reeves, J N; Sambruna, R M; Tombesi, F

    2011-01-01

    We present the analysis of Suzaku and XMM-Newton observations of the broad-line radio galaxy (BLRG) 3C 111. Its high energy emission shows variability, a harder continuum with respect to the radio quiet AGN population, and weak reflection features. Suzaku found the source in a minimum flux level; a comparison with the XMM-Newton data implies an increase of a factor of 2.5 in the 0.5-10 keV flux, in the 6 months separating the two observations. The iron K complex is detected in both datasets, with rather low equivalent width(s). The intensity of the iron K complex does not respond to the change in continuum flux. An ultra-fast, high-ionization outflowing gas is clearly detected in the XIS data; the absorber is most likely unstable. Indeed, during the XMM-Newton observation, which was 6 months after, the absorber was not detected. No clear roll-over in the hard X-ray emission is detected, probably due to the emergence of the jet as a dominant component in the hard X-ray band, as suggested by the detection above...

  6. The Baryon Acoustic Oscillation Broadband and Broad-beam Array: Design Overview and Sensitivity Forecasts

    CERN Document Server

    Pober, Jonathan C; DeBoer, David R; McDonald, Patrick; McQuinn, Matthew; Aguirre, James E; Ali, Zaki; Bradley, Richard F; Chang, Tzu-Ching; Morales, Miguel F

    2012-01-01

    This work describes a new instrument optimized for a detection of the neutral hydrogen 21cm power spectrum between redshifts of 0.5-1.5: the Baryon Acoustic Oscillation Broadband and Broad-beam (BAOBAB) Array. BAOBAB will build on the efforts of a first generation of 21cm experiments which are targeting a detection of the signal from the Epoch of Reionization at z ~ 10. At z ~ 1, the emission from neutral hydrogen in self-shielded overdense halos also presents an accessible signal, since the dominant, synchrotron foreground emission is considerably fainter than at redshift 10. The principle science driver for these observations are Baryon Acoustic Oscillations in the matter power spectrum which have the potential to act as a standard ruler and constrain the nature of dark energy. BAOBAB will fully correlate dual-polarization antenna tiles over the 600-900MHz band with a frequency resolution of 300 kHz and a system temperature of 50K. The number of antennas will grow in staged deployments, and reconfigurations...

  7. Effective band structure of random alloys.

    Science.gov (United States)

    Popescu, Voicu; Zunger, Alex

    2010-06-11

    Random substitutional A(x)B(1-x) alloys lack formal translational symmetry and thus cannot be described by the language of band-structure dispersion E(k(→)). Yet, many alloy experiments are interpreted phenomenologically precisely by constructs derived from wave vector k(→), e.g., effective masses or van Hove singularities. Here we use large supercells with randomly distributed A and B atoms, whereby many different local environments are allowed to coexist, and transform the eigenstates into an effective band structure (EBS) in the primitive cell using a spectral decomposition. The resulting EBS reveals the extent to which band characteristics are preserved or lost at different compositions, band indices, and k(→) points, showing in (In,Ga)N the rapid disintegration of the valence band Bloch character and in Ga(N,P) the appearance of a pinned impurity band.

  8. Broad belts of shear zones: The common form of surface rupture produced by the 28 June 1992 Landers, California, earthquake

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A.M.; Cruikshank, K.M. [Geological Survey, Denver, CO (United States)]|[Purdue Univ., West Lafayette, IN (United States). Richard H. Jahns Engineering Geology Lab.; Fleming, R.W. [Geological Survey, Denver, CO (United States)

    1993-12-31

    Surface rupturing during the 28 June 1992, Landers, California earthquake, east of Los Angeles, accommodated right-lateral offsets up to about 6 m along segments of distinct, en echelon fault zones with a total length of about 80 km. The offsets were accommodated generally not by faults -- distinct slip surfaces -- but rather by shear zones, tabular bands of localized shearing. In long, straight stretches of fault zones at Landers the rupture is characterized by telescoping of shear zones and intensification of shearing: broad shear zones of mild shearing, containing narrow shear zones of more intense shearing, containing even-narrower shear zones of very intense shearing, which may contain a fault. Thus the ground ruptured across broad belts of shearing with subparallel walls, oriented NW. Each broad belt consists of a broad zone of mild shearing, extending across its entire width (50 to 200 m), and much narrower (a few m wide) shear zones that accommodate most of the offset of the belt and are portrayed by en echelon tension cracks. In response to right-lateral shearing, the slices of ground bounded by the tension cracks rotated in a clockwise sense, producing left lateral shearing, and the slices were forced against the walls of the shear zone, producing thrusting. Even narrower shear zones formed within the narrow shear zones, and some of these were faults. Although the narrower shear zones probably are indicators to right-lateral fault segments at depth, the surface rupturing during the earthquake is characterized not by faulting, but by zones of shearing at various scales. Furthermore, understanding of the formation of the shear zones may be critical to understanding of earthquake faulting because, where faulting is associated with the formation of a shear zone, the faulting occurs late in the development of the shear zone. The faulting occurs after a shear zone or a belt of shear zones forms.

  9. 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.

  10. Multi-band Modelling of Appearance

    DEFF Research Database (Denmark)

    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...... to lighting conditions. Results show that localisation accuracy of facial features is considerably increased using this appearance representation under normal and abnormal lighting and at multiple scales....

  11. 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...... to lighting conditions. Results show that the localisation accuracy of facial features is considerably increased using this appearance representation under diffuse and directional lighting and at multiple scales....

  12. Coherent band pathways between knots and links

    CERN Document Server

    Buck, Dorothy

    2014-01-01

    We categorise coherent band (aka nullification) pathways between knots and 2-component links. Additionally, we characterise the minimal coherent band pathways (with intermediates) between any two knots or 2-component links with small crossing number. We demonstrate these band surgeries for knots and links with small crossing number. We apply these results to place lower bounds on the minimum number of recombinant events separating DNA configurations, restrict the recombination pathways and determine chirality and/or orientation of the resulting recombinant DNA molecules.

  13. Low band gap frequencies and multiplexing properties in 1D and 2D mass spring structures

    Science.gov (United States)

    Aly, Arafa H.; Mehaney, Ahmed

    2016-11-01

    This study reports on the propagation of elastic waves in 1D and 2D mass spring structures. An analytical and computation model is presented for the 1D and 2D mass spring systems with different examples. An enhancement in the band gap values was obtained by modeling the structures to obtain low frequency band gaps at small dimensions. Additionally, the evolution of the band gap as a function of mass value is discussed. Special attention is devoted to the local resonance property in frequency ranges within the gaps in the band structure for the corresponding infinite periodic lattice in the 1D and 2D mass spring system. A linear defect formed of a row of specific masses produces an elastic waveguide that transmits at the narrow pass band frequency. The frequency of the waveguides can be selected by adjusting the mass and stiffness coefficients of the materials constituting the waveguide. Moreover, we pay more attention to analyze the wave multiplexer and DE-multiplexer in the 2D mass spring system. We show that two of these tunable waveguides with alternating materials can be employed to filter and separate specific frequencies from a broad band input signal. The presented simulation data is validated through comparison with the published research, and can be extended in the development of resonators and MEMS verification.

  14. Naked eye visibility of Sirius in broad daylight.

    Science.gov (United States)

    Können, Gunther P; Tinbergen, Jaap; Stammes, Piet

    2015-02-01

    Sirius was spotted with the naked eye at broad daylight by looking along the finder of a 1 m telescope on La Palma Observatory at a 2370 m height. Sun elevation was 73°; Sirius was nearly straight under the Sun at 37° elevation. The sky radiance, although not recorded directly, could be determined from the simultaneously obtained high-precision wavelength-dependent sky polarization data near Sirius. This was done by fitting the polarization data with the doubling-adding KNMI (DAK) radiative transfer model, which provided the values of the surface albedo and of the aerosol optical thickness required for determining the absolute sky radiance. Our analysis implies that Sirius, when positioned overhead, can be a daytime naked eye object from sea level even if its culmination occurs at solar noon. It also suggests that the second-brightest star (Canopus), if positioned overhead, could be perceptible even at solar noon.

  15. Evidence for Photoionization Driven Broad Absorption Line Variability

    CERN Document Server

    Wang, Tinggui; Wang, Huiyuan; Ferland, Gary

    2015-01-01

    We present a qualitative analysis of the variability of quasar broad absorption lines using the large multi-epoch spectroscopic dataset of the Sloan Digital Sky Survey Data Release 10. We confirm that variations of absorption lines are highly coordinated among different components of the same ion or the same absorption component of different ions for C IV, Si IV and N V. Furthermore, we show that the equivalent widths of the lines decrease or increase statistically when the continuum brightens or dims. This is further supported by the synchronized variations of emission and absorption line equivalent width, when the well established intrinsic Baldwin effect for emission lines is taken into account. We find that the emergence of an absorption component is usually accompanying with dimming of the continuum while the disappearance of an absorption line component with brightening of the continuum. This suggests that the emergence or disappearance of a C IV absorption component is only the extreme case, when the i...

  16. Mucin biopolymers as broad-spectrum antiviral agents

    Science.gov (United States)

    Lieleg, Oliver; Lieleg, Corinna; Bloom, Jesse; Buck, Christopher B.; Ribbeck, Katharina

    2012-01-01

    Mucus is a porous biopolymer matrix that coats all wet epithelia in the human body and serves as the first line of defense against many pathogenic bacteria and viruses. However, under certain conditions viruses are able to penetrate this infection barrier, which compromises the protective function of native mucus. Here, we find that isolated porcine gastric mucin polymers, key structural components of native mucus, can protect an underlying cell layer from infection by small viruses such as human papillomavirus (HPV), Merkel cell polyomavirus (MCV), or a strain of influenza A virus. Single particle analysis of virus mobility inside the mucin barrier reveals that this shielding effect is in part based on a retardation of virus diffusion inside the biopolymer matrix. Our findings suggest that purified mucins may be used as a broad-range antiviral supplement to personal hygiene products, baby formula or lubricants to support our immune system. PMID:22475261

  17. Method for detection and imaging over a broad spectral range

    Science.gov (United States)

    Yefremenko, Volodymyr; Gordiyenko, Eduard; Pishko, legal representative, Olga; Novosad, Valentyn; Pishko, deceased; Vitalii

    2007-09-25

    A method of controlling the coordinate sensitivity in a superconducting microbolometer employs localized light, heating or magnetic field effects to form normal or mixed state regions on a superconducting film and to control the spatial location. Electron beam lithography and wet chemical etching were applied as pattern transfer processes in epitaxial Y--Ba--Cu--O films. Two different sensor designs were tested: (i) a 3 millimeter long and 40 micrometer wide stripe and (ii) a 1.25 millimeters long, and 50 micron wide meandering-like structure. Scanning the laser beam along the stripe leads to physical displacement of the sensitive area, and, therefore, may be used as a basis for imaging over a broad spectral range. Forming the superconducting film as a meandering structure provides the equivalent of a two-dimensional detector array. Advantages of this approach are simplicity of detector fabrication, and simplicity of the read-out process requiring only two electrical terminals.

  18. Broad Iron Lines in AGN and X-ray Binaries

    CERN Document Server

    Fabian, A C

    2004-01-01

    Several AGN and black hole X-ray binaries show a clear very broad iron line which is strong evidence that the black holes are rapidly spinning. Detailed analysis of these objects shows that the emission line is not significantly affected by absorption and that the source variability is principally due to variation in amplitude of a power-law. Underlying this is a much less variable, relativistically-smeared, reflection-dominated, component which carries the imprint of strong gravity at a few gravitational radii. The strong gravitational light bending in these regions then explains the power-law variability as due to changes in height of the primary X-ray source above the disc. The reflection component, in particular its variability and the profile of the iron line, enables us to study the innermost regions around an accreting, spinning, black hole.

  19. Clinical evaluation of clotrimazole. A broad-spectrum antifungal agent.

    Science.gov (United States)

    Spiekermann, P H; Young, M D

    1976-03-01

    The efficacy and safety of the broad-spectrum, topically applied antifungal agent clotrimazole were evaluated in two double-blind, multicentric trials. Ten investigators reported on a total of 1,361 cases in which a 1% solution or a 1% cream formulation was compared with its respective vehicle. Clotrimazole was therapeutically effective, as confirmed by mycological cure (negative microscopy and culture) and clinical improvement, in tinea pedis, tinea cruris, tinea corporis, pityriasis versicolor, and cutaneous candidasis. Furthermore, species identification established the efficacy of clotrimazole against Trichophyton rubrum, T mentagrophytes, Epidermophyton floccosum, Microsporum canis, Malassezia furfur (Pityrosporum orbiculare), and Candida albicans. Safety was demonstrated by the low incidence of possibly drug-related adverse experiences, namely, 19 (2.7%) of 699 patients who were treated with clotrimazole, of whom four (0.6%) discontinued treatment.

  20. The Broad Line Radio Galaxy J2114+820

    CERN Document Server

    Lara, L; Cotton, W D; Feretti, L; Giovannini, G; Marcaide, J M; Venturi, T

    1998-01-01

    In the frame of the study of a new sample of large angular size radio galaxies selected from the NRAO VLA Sky Survey, we have made radio observations of J2114+820, a low power radio galaxy with an angular size of 6'. Its radio structure basically consists of a prominent core, a jet directed in north-west direction and two extended S-shaped lobes. We have also observed the optical counterpart of J2114+820, a bright elliptical galaxy with a strong unresolved central component. The optical spectrum shows broad emission lines. This fact, together with its low radio power and FR-I type morphology, renders J2114+820 a non-trivial object from the point of view of the current unification schemes of radio loud active galactic nuclei.

  1. Spontaneous pattern formation in broad-area lasers

    Science.gov (United States)

    Krents, Anton; Anchikov, Dmitry; Molevich, Nonna; Pakhomov, Anton

    2016-10-01

    The paper studies the spontaneous formation of nonlinear optical patterns in broad area lasers. Spatiotemporal transverse dynamics of the laser is described by the Maxwell-Bloch equations (MBE). The instability of the steady-state solution leads to pattern formation. Two different types of instabilities were observed analytically (Hopf and wave). 2D numerical simulation of the MBE with the random initial conditions has been performed using a split-step Fourier method and periodic boundary conditions. Hopf instability leads to homogeneous oscillations, spatiotemporal chaos and spiral waves. In the case of wave instability, the direct numerical simulation showed that space-time (periodic, quasi-periodic, or chaotic) modulation of the uniform profile is observed. The characteristic sizes of excited patterns are in good agreement with analytical predictions. The nonlinear interaction of four travelling waves forms a square optical vortex lattice similar to the vortex lattices observed in superconductors and Bose Einstein condensate.

  2. Broadly neutralizing antibodies: An approach to control HIV-1 infection.

    Science.gov (United States)

    Yaseen, Mahmoud Mohammad; Yaseen, Mohammad Mahmoud; Alqudah, Mohammad Ali

    2017-01-02

    Although available antiretroviral therapy (ART) has changed human immunodeficiency virus (HIV)-1 infection to a non-fatal chronic disease, the economic burden of lifelong therapy, severe adverse ART effects, daily ART adherence, and emergence of ART-resistant HIV-1 mutants require prospecting for alternative therapeutic modalities. Indeed, a growing body of evidence suggests that broadly neutralizing anti-HIV-1 antibodies (BNAbs) may offer one such feasible alternative. To evaluate their therapeutic potential in established HIV-1 infection, we sought to address recent advances in pre-clinical and clinical investigations in this area of HIV-1 research. In addition, we addressed the obstacles that may impede the success of such immunotherapeutic approach, suggested strategic solutions, and briefly compared this approach with the currently used ART to open new insights for potential future passive immunotherapy for HIV-1 infection.

  3. Engineering broadly neutralizing antibodies for HIV prevention and therapy.

    Science.gov (United States)

    Hua, Casey K; Ackerman, Margaret E

    2016-08-01

    A combination of advances spanning from isolation to delivery of potent HIV-specific antibodies has begun to revolutionize understandings of antibody-mediated antiviral activity. As a result, the set of broadly neutralizing and highly protective antibodies has grown in number, diversity, potency, and breadth of viral recognition and neutralization. These antibodies are now being further enhanced by rational engineering of their anti-HIV activities and coupled to cutting edge gene delivery and strategies to optimize their pharmacokinetics and biodistribution. As a result, the prospects for clinical use of HIV-specific antibodies to treat, clear, and prevent HIV infection are gaining momentum. Here we discuss the diverse methods whereby antibodies are being optimized for neutralization potency and breadth, biodistribution, pharmacokinetics, and effector function with the aim of revolutionizing HIV treatment and prevention options.

  4. SPECTROSCOPY OF BROAD-LINE BLAZARS FROM 1LAC

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, Michael S.; Romani, Roger W.; Healey, Stephen E.; Michelson, Peter F. [Department of Physics/KIPAC, Stanford University, Stanford, CA 94305 (United States); Cotter, Garret; Potter, William J. [Department of Astrophysics, University of Oxford, Oxford OX1 3RH (United Kingdom); Readhead, Anthony C. S.; Richards, Joseph L.; Max-Moerbeck, Walter; King, Oliver G. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)

    2012-03-20

    We report on optical spectroscopy of 165 flat spectrum radio quasars (FSRQs) in the Fermi 1LAC sample, which have helped allow a nearly complete study of this population. Fermi FSRQs show significant evidence for non-thermal emission even in the optical; the degree depends on the {gamma}-ray hardness. They also have smaller virial estimates of hole mass than the optical quasar sample. This appears to be largely due to a preferred (axial) view of the {gamma}-ray FSRQ and non-isotropic (H/R {approx} 0.4) distribution of broad-line velocities. Even after correction for this bias, the Fermi FSRQs show higher mean Eddington ratios than the optical population. A comparison of optical spectral properties with Owens Valley Radio Observatory radio flare activity shows no strong correlation.

  5. Broad activation of latent HIV-1 in vivo

    DEFF Research Database (Denmark)

    Barton, Kirston; Hiener, Bonnie; Winckelmann, Anni;

    2016-01-01

    The 'shock and kill' approach to cure human immunodeficiency virus (HIV) includes transcriptional induction of latent HIV-1 proviruses using latency-reversing agents (LRAs) with targeted immunotherapy to purge infected cells. The administration of LRAs (panobinostat or vorinostat) to HIV-1-infected...... individuals on antiretroviral therapy induces a significant increase in cell-associated unspliced (CA-US) HIV-1 RNA from CD4(+) T cells. However, it is important to discern whether the increases in CA-US HIV-1 RNA are due to limited or broad activation of HIV-1 proviruses. Here we use single-genome sequencing...... to find that the RNA transcripts observed following LRA administration are genetically diverse, indicating activation of transcription from an extensive range of proviruses. Defective sequences are more frequently found in CA HIV-1 RNA than in HIV-1 DNA, which has implications for developing an accurate...

  6. Rufinamide: a novel broad-spectrum antiepileptic drug.

    Science.gov (United States)

    Wheless, James W; Vazquez, Blanca

    2010-01-01

    The last 20 years have witnessed a tremendous explosion in the number of antiepileptic drugs (AEDs) as well as the introduction of AEDS developed for specific epilepsy syndromes. The study of the efficacy and side effect profile of AEDs for unique epilepsy syndromes has allowed neurologists to utilize evidence-based medicine when treating patients. In late 2008, the Food and Drug Administration approved rufinamide for adjunctive use in the treatment of seizures associated with Lennox-Gastaut syndrome. This unique chemical compound is also the first new AED to reach the market in the United States having a pediatric indication prior to approval for adults. Rufinamide appears to have a broad spectrum of efficacy, is well tolerated, and may be rapidly initiated--properties that will likely extend its use outside of Lennox-Gastaut syndrome.

  7. Robust linear regression with broad distributions of errors

    CERN Document Server

    Postnikov, Eugene B

    2015-01-01

    We consider the problem of linear fitting of noisy data in the case of broad (say $\\alpha$-stable) distributions of random impacts ("noise"), which can lack even the first moment. This situation, common in statistical physics of small systems, in Earth sciences, in network science or in econophysics, does not allow for application of conventional Gaussian maximum-likelihood estimators resulting in usual least-squares fits. Such fits lead to large deviations of fitted parameters from their true values due to the presence of outliers. The approaches discussed here aim onto the minimization of the width of the distribution of residua. The corresponding width of the distribution can either be defined via the interquantile distance of the corresponding distributions or via the scale parameter in its characteristic function. The methods provide the robust regression even in the case of short samples with large outliers, and are equivalent to the normal least squares fit for the Gaussian noises. Our discussion is il...

  8. Characterisation of a Broad Energy Germanium (BEGe) detector

    Energy Technology Data Exchange (ETDEWEB)

    Barrientos, D., E-mail: diego_barrientos@usal.es [Laboratorio de Radiaciones Ionizantes, University of Salamanca (Spain); Boston, A.J.; Boston, H.C. [Nuclear Physics Group, University of Liverpool (United Kingdom); Quintana, B.; Sagrado, I.C. [Laboratorio de Radiaciones Ionizantes, University of Salamanca (Spain); Unsworth, C.; Moon, S.; Cresswell, J.R. [Nuclear Physics Group, University of Liverpool (United Kingdom)

    2011-08-21

    Characterisation of Germanium detectors used for gamma-ray tracking or medical imaging is one of the current goals in the Nuclear physics community. Good knowledge of detector response to different gamma radiations is needed for this purpose. In order to develop this task, Pulse Shape Analysis (PSA) techniques have been developed for different detector geometries or setups. In this work, we present the results of the application of PSA for a Canberra Broad Energy Germanium (BEGe) detector. This detector was scanned across its front and bottom face using a fully digital data acquisition system; allowing to record detector charge pulse shapes from well defined positions with collimated sources of {sup 241}Am, {sup 22}Na and {sup 137}Cs. With the study of the data acquired, characteristics of the inner detector geometry like crystal limits or positions of contact and isolate can be found, as well as the direction of the axes for the Germanium crystal.

  9. Broad spectrum moderators and advanced reflector filters using 208Pb

    DEFF Research Database (Denmark)

    Schönfeldt, Troels; Batkov, K.; Klinkby, Esben Bryndt

    2015-01-01

    thermalizing property of 208Pb to design a broad spectrum moderator, i.e. a moderator which emits thermal and cold neutrons from the same position. Using 208Pb as a reflector filter material is shown to be slightly less efficient than a conventional beryllium reflector filter. However, when surrounding...... the reflector filter by a cold moderator it is possible to regain the neutrons with wavelengths below the Bragg edge, which are suppressed in the beryllium reflector filter. In both the beryllium and lead case surrounding the reflector filter with a cold moderator increases the cold brightness significantly......Cold and thermal neutrons used in neutrons scattering experiments are produced in nuclear reactors and spallation sources. The neutrons are cooled to thermal or cold temperatures in thermal and cold moderators, respectively. The present study shows that it is possible to exploit the poor...

  10. Band engineering of thermoelectric materials.

    Science.gov (United States)

    Pei, Yanzhong; Wang, Heng; Snyder, G J

    2012-12-01

    Lead chalcogenides have long been used for space-based and thermoelectric remote power generation applications, but recent discoveries have revealed a much greater potential for these materials. This renaissance of interest combined with the need for increased energy efficiency has led to active consideration of thermoelectrics for practical waste heat recovery systems-such as the conversion of car exhaust heat into electricity. The simple high symmetry NaCl-type cubic structure, leads to several properties desirable for thermoelectricity, such as high valley degeneracy for high electrical conductivity and phonon anharmonicity for low thermal conductivity. The rich capabilities for both band structure and microstructure engineering enable a variety of approaches for achieving high thermoelectric performance in lead chalcogenides. This Review focuses on manipulation of the electronic and atomic structural features which makes up the thermoelectric quality factor. While these strategies are well demonstrated in lead chalcogenides, the principles used are equally applicable to most good thermoelectric materials that could enable improvement of thermoelectric devices from niche applications into the mainstream of energy technologies.

  11. Density of States for Warped Energy Bands

    Science.gov (United States)

    Mecholsky, Nicholas A.; Resca, Lorenzo; Pegg, Ian L.; Fornari, Marco

    2016-02-01

    Warping of energy bands can affect the density of states (DOS) in ways that can be large or subtle. Despite their potential for significant practical impacts on materials properties, these effects have not been rigorously demonstrated previously. Here we rectify this using an angular effective mass formalism that we have developed. To clarify the often confusing terminology in this field, “band warping” is precisely defined as pertaining to any multivariate energy function E(k) that does not admit a second-order differential at an isolated critical point in k-space, which we clearly distinguish from band non-parabolicity. We further describe band “corrugation” as a qualitative form of band warping that increasingly deviates from being twice differentiable at an isolated critical point. These features affect the density-of-states and other parameters ascribed to band warping in various ways. We demonstrate these effects, providing explicit calculations of DOS and their effective masses for warped energy dispersions originally derived by Kittel and others. Other physical and mathematical examples are provided to demonstrate fundamental distinctions that must be drawn between DOS contributions that originate from band warping and contributions that derive from band non-parabolicity. For some non-degenerate bands in thermoelectric materials, this may have profound consequences of practical interest.

  12. Triaxial superdeformed bands in {sup 86}Zr

    Energy Technology Data Exchange (ETDEWEB)

    Sarantites, D.G.; LaFosse, D.R.; Devlin, M.; Lerma, F. [Chemistry Department, Washington University, St. Louis, Missouri 63130 (United States); Wood, V.Q.; Saladin, J.X.; Winchell, D.F. [Physics Department, University of Pittsburgh, Pittsburgh, Pennsylvania 15260 (United States); Baktash, C.; Yu, C. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Fallon, P.; Lee, I.Y.; Macchiavelli, A.O.; MacLeod, R.W. [Nuclear Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Afanasjev, A.V.; Ragnarsson, I. [Department of Mathematical Physics, Lund Institute of Technology, Box 118, S-22100 Lund (Sweden)

    1998-01-01

    Four new superdeformed bands have been found in the nucleus {sup 86}Zr. The good agreement between experiment and configuration-dependent shell correction calculations suggests that three of the bands have triaxial superdeformed shapes. Such unique features in mass A{approximately}80 superdeformed bands have been predicted, but not observed experimentally until now. A fourth band in {sup 86}Zr is interesting due to a fairly constant and unusually high dynamic moment of inertia. Possible interpretations of this structure are discussed. {copyright} {ital 1998} {ital The American Physical Society}

  13. Magnetic resonance imaging of iliotibial band syndrome.

    Science.gov (United States)

    Ekman, E F; Pope, T; Martin, D F; Curl, W W

    1994-01-01

    Seven cases of iliotibial band syndrome and the pathoanatomic findings of each, as demonstrated by magnetic resonance imaging, are presented. These findings were compared with magnetic resonance imaging scans of 10 age- and sex-matched control knees without evidence of lateral knee pain. Magnetic resonance imaging signal consistent with fluid was seen deep to the iliotibial band in the region of the lateral femoral epicondyle in five of the seven cases. Additionally, when compared with the control group, patients with iliotibial band syndrome demonstrated a significantly thicker iliotibial band over the lateral femoral epicondyle (P iliotibial band in the disease group was 5.49 +/- 2.12 mm, as opposed to 2.52 +/- 1.56 mm in the control group. Cadaveric dissections were performed on 10 normal knees to further elucidate the exact nature of the area under the iliotibial band. A potential space, i.e., a bursa, was found between the iliotibial band and the knee capsule. This series suggests that magnetic resonance imaging demonstrates objective evidence of iliotibial band syndrome and can be helpful when a definitive diagnosis is essential. Furthermore, correlated with anatomic dissection, magnetic resonance imaging identifies this as a problem within a bursa beneath the iliotibial band and not a problem within the knee joint.

  14. Asymmetric localization in disordered Landau bands

    Energy Technology Data Exchange (ETDEWEB)

    Nita, M [Institute of Physics and Technology of Materials, PO Box MG7, Bucharest-Magurele (Romania); Aldea, A [Institute of Physics and Technology of Materials, PO Box MG7, Bucharest-Magurele (Romania); Zittartz, J [Institute of Theoretical Physics, Cologne University, 50937 Cologne (Germany)

    2007-06-06

    We show that, due to band mixing, the eigenstate localization within the disordered Landau bands gets an asymmetric structure: the degree of localization increases in the lower part of the band and decreases in the upper one. The calculation is performed for a two-dimensional lattice with the Anderson disorder potential and we prove that this effect is related to the upper shift of the extended states within the band and is enhanced by the disorder strength. The asymmetric localization and the energy shift disappear when the interband coupling is switched off.

  15. The Nature of Partial Covering in Broad Absorption Line Quasars

    Science.gov (United States)

    Leighly, Karen

    2012-10-01

    Ejected gas is seen as broad absorption lines in 20% of quasars. It has been known for 15 years that prominent lines such as CIV are usually saturated but not black because the absorbing gas only partially covers the continuum emission region. Therefore, column densities estimated from these lines are only lower limits. Accurate column densities can be obtained from rare ions that have two or more transitions from the same lower level, so that the optical depth and covering fraction can be solved for simultanously. Suitable lines are hard to find, so such measurements are rare. We have found that metastable helium is particularly useful for these measurements. Yet despite these advances, partial covering remains a just a parameter and its physical nature is not understood.We propose a unique experiment to constrain the physical nature of partial covering. We will compare the covering fraction measured from PV {a doublet in the far UV} with that measured from metastable HeI {optical and IR}. The ions creating these lines are relatively rare, and they present similar opacity over a wide range of gas parameters. But due to their wide wavelength separation, these lines probe dramatically different regions of the continuum source, the temperature-dependent accretion disk. So we expect different covering fraction behavior for different partial covering scenarios. This experiment is relevant for understanding the geometry and clumpiness of the outflow, and the results may impact our understanding of the global covering fraction, a parameter critical for determining the outflow kinetic luminosity, and thereby estimating feedback efficiency for broad absorption line outflows.

  16. Broad epitope coverage of a human in vitro antibody library

    Science.gov (United States)

    Sivasubramanian, Arvind; Lynaugh, Heather; Yu, Yao; Miles, Adam; Eckman, Josh; Schutz, Kevin; Piffath, Crystal; Boland, Nadthakarn; Durand, Stéphanie; Boland, Todd; Vásquez, Maximiliano; Xu, Yingda; Abdiche, Yasmina

    2017-01-01

    ABSTRACT Successful discovery of therapeutic antibodies hinges on the identification of appropriate affinity binders targeting a diversity of molecular epitopes presented by the antigen. Antibody campaigns that yield such broad “epitope coverage” increase the likelihood of identifying candidates with the desired biological functions. Accordingly, epitope binning assays are employed in the early discovery stages to partition antibodies into epitope families or “bins” and prioritize leads for further characterization and optimization. The collaborative program described here, which used hen egg white lysozyme (HEL) as a model antigen, combined 3 key capabilities: 1) access to a diverse panel of antibodies selected from a human in vitro antibody library; 2) application of state-of-the-art high-throughput epitope binning; and 3) analysis and interpretation of the epitope binning data with reference to an exhaustive set of published antibody:HEL co-crystal structures. Binning experiments on a large merged panel of antibodies containing clones from the library and the literature revealed that the inferred epitopes for the library clones overlapped with, and extended beyond, the known structural epitopes. Our analysis revealed that nearly the entire solvent-exposed surface of HEL is antigenic, as has been proposed for protein antigens in general. The data further demonstrated that synthetic antibody repertoires provide as wide epitope coverage as those obtained from animal immunizations. The work highlights molecular insights contributed by increasingly higher-throughput binning methods and their broad utility to guide the discovery of therapeutic antibodies representing a diverse set of functional epitopes. PMID:27748644

  17. Tri-band optical coherence tomography for lipid and vessel spectroscopic imaging

    Science.gov (United States)

    Yu, Luoqin; Kang, Jiqiang; Wang, Xie; Wei, Xiaoming; Chan, Kin-Tak; Lee, Nikki P.; Wong, Kenneth K. Y.

    2016-03-01

    Optical coherence tomography (OCT) has been utilized for various functional imaging applications. One of its highlights comes from spectroscopic imaging, which can simultaneously obtain both morphologic and spectroscopic information. Assisting diagnosis and therapeutic intervention of coronary artery disease is one of the major directions in spectroscopic OCT applications. Previously Tanaka et al. have developed a spectral domain OCT (SDOCT) to image lipid distribution within blood vessel [1]. In the meantime, Fleming et al. have demonstrated optical frequency domain imaging (OFDI) by a 1.3-μm swept source and quadratic discriminant analysis model [2]. However, these systems suffered from burdensome computation as the optical properties' variation was calculated from a single-band illumination that provided limited contrast. On the other hand, multi-band OCT facilitates contrast enhancement with separated wavelength bands, which further offers an easier way to distinguish different materials. Federici and Dubois [3] and Tsai and Chan [4] have demonstrated tri-band OCT systems to further enhance the image contrast. However, these previous work provided under-explored functional properties. Our group has reported a dual-band OCT system based on parametrically amplified Fourier domain mode-locked (FDML) laser with time multiplexing scheme [5] and a dual-band FDML laser OCT system with wavelength-division multiplexing [6]. Fiber optical parametric amplifier (OPA) can be ideally incorporated in multi-band spectroscopic OCT system as it has a broad amplification window and offers an additional output range at idler band, which is phase matched with the signal band. The sweeping ranges can thus overcome traditional wavelength bands that are limited by intra-cavity amplifiers in FDML lasers. Here, we combines the dual-band FDML laser together with fiber OPA, which consequently renders a simultaneous tri-band output at 1.3, 1.5, and 1.6 μm, for intravascular applications

  18. Response of Thematic Mapper bands to plant water stress

    Science.gov (United States)

    Cibula, W. G.; Zetka, E. F.; Rickman, D. L.

    1992-01-01

    Changes in leaf reflectance as water content decreases have been hypothesized to occur in the 1.55-1.75 and 2.08-2.35 micron wavelength regions. To evaluate this hypothesis, studies were conducted on ryegrass (Lolium multiflorum Lam.) and oats (Avena sativa L.), which were grown in a controlled, outdoor situation. Both fully-watered control beds and water-stressed beds were periodically examined with a spectroradiometer calibrated against a reflectance reference of polytetrafluoroethylene. The observed changes correspond to those predicted by stochastic leaf models employed by other investigators (leaf reflection increases in the 1.55-1.75 micron region as leaf water content decreases). Although the percentage changes in TM bands 1-3 are nearly as great as those found in TM bands 5 and 7, the absolute values of reflectance change are much lower. It is believed that these patterns are probably characteristic of a broad range of vegetation types. In terms of phenomena detection, these patterns should be considered in any practical remote sensing sensor scenario.

  19. Stellar classification from single-band imaging using machine learning

    CERN Document Server

    Kuntzer, T; Courbin, F

    2016-01-01

    Information on the spectral types of stars is of great interest in view of the exploitation of space-based imaging surveys. In this article, we investigate the classification of stars into spectral types using only the shape of their diffraction pattern in a single broad-band image. We propose a supervised machine learning approach to this endeavour, based on principal component analysis (PCA) for dimensionality reduction, followed by artificial neural networks (ANNs) estimating the spectral type. Our analysis is performed with image simulations mimicking the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) in the F606W and F814W bands, as well as the Euclid VIS imager. We first demonstrate this classification in a simple context, assuming perfect knowledge of the point spread function (PSF) model and the possibility of accurately generating mock training data for the machine learning. We then analyse its performance in a fully data-driven situation, in which the training would be performed with...

  20. Narrow band gap conjugated polymers for emergent optoelectronic technologies

    Science.gov (United States)

    Azoulay, Jason D.; Zhang, Benjamin A.; London, Alexander E.

    2015-09-01

    Conjugated organic molecules effectively produce and harvest visible light and find utility in a variety of emergent optoelectronic technologies. There is currently interest in expanding the scope of these materials to extend functionality into the infrared (IR) spectral regions and endow functionality relevant in emergent technologies. Developing an understanding of the interplay between chemical and electronic structure in these systems will require control of the frontier orbital energetics (separation, position, and alignment), ground state electronic configurations, interchain arrangements, solid-state properties, and many other molecular features with synthetic precision that has yet to be demonstrated. Bridgehead imine substituted 4H-cyclopenta[2,1-b:3,4-b']dithiophene (CPDT) structural units, in combination with strong acceptors with progressively delocalized π-systems, afford modular donor-acceptor copolymers with broad and long wavelength absorption that spans technologically relevant wavelength (λ) ranges from 0.7 < λ < 3.2 μm.1 Here we demonstrate that electronic and structural manipulation play a major role in influencing the energetics of these systems and ultimately controlling the band gap of the materials. These results bear implication in the development of very narrow band gap systems where precise control will be necessary for achieving desired properties such as interactions with longer wavelength light.

  1. Wide-band profile domain pulsar timing analysis

    Science.gov (United States)

    Lentati, L.; Kerr, M.; Dai, S.; Hobson, M. P.; Shannon, R. M.; Hobbs, G.; Bailes, M.; Bhat, N. D. Ramesh; Burke-Spolaor, S.; Coles, W.; Dempsey, J.; Lasky, P. D.; Levin, Y.; Manchester, R. N.; Osłowski, S.; Ravi, V.; Reardon, D. J.; Rosado, P. A.; Spiewak, R.; van Straten, W.; Toomey, L.; Wang, J.; Wen, L.; You, X.; Zhu, X.

    2017-04-01

    We extend profile domain pulsar timing to incorporate wide-band effects such as frequency-dependent profile evolution and broad-band shape variation in the pulse profile. We also incorporate models for temporal variations in both pulse width and in the separation in phase of the main pulse and interpulse. We perform the analysis with both nested sampling and Hamiltonian Monte Carlo methods. In the latter case, we introduce a new parametrization of the posterior that is extremely efficient in the low signal-to-noise regime and can be readily applied to a wide range of scientific problems. We apply this methodology to a series of simulations, and to between seven and nine years of observations for PSRs J1713+0747, J1744-1134 and J1909-3744 with frequency coverage that spans 700-3600 Mhz. We use a smooth model for profile evolution across the full frequency range, and compare smooth and piecewise models for the temporal variations in dispersion measure (DM). We find that the profile domain framework consistently results in improved timing precision compared to the standard analysis paradigm by as much as 40 per cent for timing parameters. Incorporating smoothness in the DM variations into the model further improves timing precision by as much as 30 per cent. For PSR J1713+0747, we also detect pulse shape variation uncorrelated between epochs, which we attribute to variation intrinsic to the pulsar at a level consistent with previously published analyses. Not accounting for this shape variation biases the measured arrival times at the level of ∼30 ns, the same order of magnitude as the expected shift due to gravitational waves in the pulsar timing band.

  2. Stellar classification from single-band imaging using machine learning

    Science.gov (United States)

    Kuntzer, T.; Tewes, M.; Courbin, F.

    2016-06-01

    Information on the spectral types of stars is of great interest in view of the exploitation of space-based imaging surveys. In this article, we investigate the classification of stars into spectral types using only the shape of their diffraction pattern in a single broad-band image. We propose a supervised machine learning approach to this endeavour, based on principal component analysis (PCA) for dimensionality reduction, followed by artificial neural networks (ANNs) estimating the spectral type. Our analysis is performed with image simulations mimicking the Hubble Space Telescope (HST) Advanced Camera for Surveys (ACS) in the F606W and F814W bands, as well as the Euclid VIS imager. We first demonstrate this classification in a simple context, assuming perfect knowledge of the point spread function (PSF) model and the possibility of accurately generating mock training data for the machine learning. We then analyse its performance in a fully data-driven situation, in which the training would be performed with a limited subset of bright stars from a survey, and an unknown PSF with spatial variations across the detector. We use simulations of main-sequence stars with flat distributions in spectral type and in signal-to-noise ratio, and classify these stars into 13 spectral subclasses, from O5 to M5. Under these conditions, the algorithm achieves a high success rate both for Euclid and HST images, with typical errors of half a spectral class. Although more detailed simulations would be needed to assess the performance of the algorithm on a specific survey, this shows that stellar classification from single-band images is well possible.

  3. Virilization of the Broad Line Region in Active Galactic Nuclei - connection between shifts and widths of broad emission lines

    CERN Document Server

    Jonic, Sanja; Ilic, Dragana; Popovic, Luka C

    2016-01-01

    We investigate the virilization of the emission lines Hbeta and Mg II in the sample of 287 Type 1 Active Galactic Nuclei taken from the Sloan Digital Sky Survey database. We explore the connections between the intrinsic line shifts and full widths at different levels of maximal intensity. We found that: (i) Hbeta seems to be a good virial estimator of black hole masses, and an intrinsic redshift of Hbeta is dominantly caused by the gravitational effect, (ii) there is an anti-correlation between the redshift and width of the wings of the Mg II line, (iii) the broad Mg II line can be used as virial estimator only at 50% of the maximal intensity, while the widths and intrinsic shifts of the line wings can not be used for this purpose.

  4. Solid State KA-Band, Solid State W-Band and TWT Amplifiers Project

    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...

  5. Band Gap Engineering and Layer-by-Layer Band Gap Mapping of Selenium-doped Molybdenum Disulfide

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yongji [Rice University; Liu, Zheng [Rice University; Lupini, Andrew R [ORNL; Lin, Junhao [ORNL; Pantelides, Sokrates T [ORNL; Pennycook, Stephen J [ORNL; Zhou, Wu [ORNL; Ajayan, Pullikel M [Rice University

    2014-01-01

    Ternary two-dimensional dichalcogenide alloys exhibit compositionally modulated electronic structure and hence, control of dopant concentration within each layer of these layered compounds provides a powerful way to modify their properties. The challenge then becomes quantifying and locating the dopant atoms within each layer in order to better understand and fine-tune the desired properties. Here we report the synthesis of selenium substitutionally doped molybdenum disulfide atomic layers, with a broad range of selenium concentrations, resulting in band gap modulations of over 0.2 eV. Atomic scale chemical analysis using Z-contrast imaging provides direct maps of the dopant atom distribution in individual MoS2 layers and hence a measure of the local band gaps. Furthermore, in a bilayer structure, the dopant distribution of each layer is imaged independently. We demonstrate that each layer in the bilayer contains similar doping levels, randomly distributed, providing new insights into the growth mechanism and alloying behavior in two-dimensional dichalcogenide atomic layers. The results show that growth of uniform, ternary, two-dimensional dichalcogenide alloy films with tunable electronic properties is feasible.

  6. 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...

  7. Complex band structure and superlattice electronic states

    Science.gov (United States)

    Schulman, J. N.; McGill, T. C.

    1981-04-01

    The complex band structures of the bulk materials which constitute the alternating layer (001) semiconductor-semiconductor superlattice are investigated. The complex bands near the center of the Brillouin zone in the [001] direction are studied in detail. The decay lengths of superlattice states whose energies lie in the bulk band gaps of one of the semiconductors are determined from the dispersion curves of these bands for imaginary k-->. This method is applied using a tight-binding band-structure calculation to two superlattices: the AlAs-GaAs superlattice and the CdTe-HgTe superlattice. The decay lengths of AlAs-GaAs superlattice conduction-band minimum states are found to be substantially shorter than those for the CdTe-HgTe superlattice. These differences in the decay of the states in the two superlattices result in differences in the variation of the conduction-band effective masses with the thickness of the AlAs and CdTe layers. The conduction-band effective masses increase more rapidly with AlAs thickness in the AlAs-GaAs superlattice than with CdTe thickness in the CdTe-HgTe superlattice.

  8. Concert Band Instrumentation: Realities and Remedies.

    Science.gov (United States)

    Rogers, George L.

    1991-01-01

    Suggests ways to solve problems resulting from imbalanced instrumentation in school concert bands. Identifies sources of imbalance. Encourages band directors to plan for correct instrumentation, to match students' characteristics and abilities to instruments, and to recruit students to play needed instruments. Discusses the benefits of balanced…

  9. Link adaptation in unlicensed radio bands

    NARCIS (Netherlands)

    Haartsen, Jaap C.; Schutter, George B.W.

    2005-01-01

    This paper presents a new collaborative mechanism for efficient coordination of radio communication devices, in particular addressing the unlicensed ISM band at 2.4 GHz. As the traffic in the ISM band is increasing tremendously, the potential for interference between uncoordinated devices is becomin

  10. Error Analysis of Band Matrix Method

    OpenAIRE

    Taniguchi, Takeo; Soga, Akira

    1984-01-01

    Numerical error in the solution of the band matrix method based on the elimination method in single precision is investigated theoretically and experimentally, and the behaviour of the truncation error and the roundoff error is clarified. Some important suggestions for the useful application of the band solver are proposed by using the results of above error analysis.

  11. 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...

  12. 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.

  13. Broad-scale patterns of late jurassic dinosaur paleoecology.

    Directory of Open Access Journals (Sweden)

    Christopher R Noto

    Full Text Available BACKGROUND: There have been numerous studies on dinosaur biogeographic distribution patterns. However, these distribution data have not yet been applied to ecological questions. Ecological studies of dinosaurs have tended to focus on reconstructing individual taxa, usually through comparisons to modern analogs. Fewer studies have sought to determine if the ecological structure of fossil assemblages is preserved and, if so, how dinosaur communities varied. Climate is a major component driving differences between communities. If the ecological structure of a fossil locality is preserved, we expect that dinosaur assemblages from similar environments will share a similar ecological structure. METHODOLOGY/PRINCIPAL FINDINGS: This study applies Ecological Structure Analysis (ESA to a dataset of 100+ dinosaur taxa arranged into twelve composite fossil assemblages from around the world. Each assemblage was assigned a climate zone (biome based on its location. Dinosaur taxa were placed into ecomorphological categories. The proportion of each category creates an ecological profile for the assemblage, which were compared using cluster and principal components analyses. Assemblages grouped according to biome, with most coming from arid or semi-arid/seasonal climates. Differences between assemblages are tied to the proportion of large high-browsing vs. small ground-foraging herbivores, which separates arid from semi-arid and moister environments, respectively. However, the effects of historical, taphonomic, and other environmental factors are still evident. CONCLUSIONS/SIGNIFICANCE: This study is the first to show that the general ecological structure of Late Jurassic dinosaur assemblages is preserved at large scales and can be assessed quantitatively. Despite a broad similarity of climatic conditions, a degree of ecological variation is observed between assemblages, from arid to moist. Taxonomic differences between Asia and the other regions demonstrate at

  14. Broad support evident for the emerging specialty of orofacial pain.

    Science.gov (United States)

    Talley, R L; Fricton, J R; Okeson, J P

    2000-01-01

    The emerging field of Orofacial Pain is being considered by the American Dental Association for full status as a new dental specialty. Many recent advances in the neuroscience of orofacial pain have lead to treatments by orofacial pain dentists that provide significant relief for patients with chronic orofacial pain disorders. However, access to this care has been limited leaving many patients to continue to suffer. Subsequently, recent efforts to improve this by developing the field into a specialty have shown broad support among dentists and increased awareness of the benefits this field can provide for dentists and their patients. A recent survey of 805 individuals in the general population who reported having a persistent pain disorder revealed that more than four out of 10 people have yet to find adequate relief, saying their pain is out of control-despite having the pain for more than 5 years and switching doctors at least once. "This survey suggests that there are millions of people living with severe uncontrolled pain," says Russell Portenoy, MD, President of the American Pain Society. "This is a great tragedy. Although not everyone can be helped, it is very likely that most of these patients could benefit if provided with state-of-the-art therapies and improved access to pain specialists when needed." (1). Development of the field of Orofacial Pain into a dental specialty has been motivated primarily by this issue; patients with complex chronic orofacial pain disorders have not been historically treated well by any discipline of health care. Recent studies of chronic orofacial pain patients have found that these patients have a high number of previous clinicians and have endured many years with pain prior to seeing an orofacial pain dentist (2) (Fig. 1). Complex pain patients and the clinicians who see them are often confused about whom they should consult for relief of the painful disorder. Treatment for these patients within the existing structure of

  15. Band structure of superdeformed bands in odd-A Hg nuclei

    Institute of Scientific and Technical Information of China (English)

    陈星渠; 邢正

    1997-01-01

    Through particle-rotor model, band structure of superdeformed bands in odd-A Hg nuclei is analysed. An overall and excellent agreement between the calculated and observed kinematic and dynamic moments of inertia is obtained. The electromagnetic transition properties of SD bands can be used to identify the configuration with certainty.

  16. 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.

  17. Biodiversity inhibits parasites: Broad evidence for the dilution effect.

    Science.gov (United States)

    Civitello, David J; Cohen, Jeremy; Fatima, Hiba; Halstead, Neal T; Liriano, Josue; McMahon, Taegan A; Ortega, C Nicole; Sauer, Erin Louise; Sehgal, Tanya; Young, Suzanne; Rohr, Jason R

    2015-07-14

    Infectious diseases of humans, wildlife, and domesticated species are increasing worldwide, driving the need to understand the mechanisms that shape outbreaks. Simultaneously, human activities are drastically reducing biodiversity. These concurrent patterns have prompted repeated suggestions that biodiversity and disease are linked. For example, the dilution effect hypothesis posits that these patterns are causally related; diverse host communities inhibit the spread of parasites via several mechanisms, such as by regulating populations of susceptible hosts or interfering with parasite transmission. However, the generality of the dilution effect hypothesis remains controversial, especially for zoonotic diseases of humans. Here we provide broad evidence that host diversity inhibits parasite abundance using a meta-analysis of 202 effect sizes on 61 parasite species. The magnitude of these effects was independent of host density, study design, and type and specialization of parasites, indicating that dilution was robust across all ecological contexts examined. However, the magnitude of dilution was more closely related to the frequency, rather than density, of focal host species. Importantly, observational studies overwhelmingly documented dilution effects, and there was also significant evidence for dilution effects of zoonotic parasites of humans. Thus, dilution effects occur commonly in nature, and they may modulate human disease risk. A second analysis identified similar effects of diversity in plant-herbivore systems. Thus, although there can be exceptions, our results indicate that biodiversity generally decreases parasitism and herbivory. Consequently, anthropogenic declines in biodiversity could increase human and wildlife diseases and decrease crop and forest production.

  18. Transient Broad Specular Reflections from Titan's North Pole

    Science.gov (United States)

    Dhingra, Rajani D.; Barnes, Jason W.

    2016-10-01

    In 2014, Cassini observed rough patches or transient broad specular reflections on one of Titan's seas, Punga Mare. These observations were made by the Visual and Infrared Mapping Spectrometer (VIMS). The rough patches were interpreted to be waves on the surface of the hydrocarbon sea with slopes of 60 ± 10. Although long anticipated, this was an important observation since there was no detection of waves in the initial flybys of north polar lakes and seas until the northern summer approached.We have analyzed several recent VIMS flybys of Titan's north pole looking for these rough surfaces. Our observations are classified as clouds, mudflats, specular reflections, or waves based on VIMS color composites. We observe waves in at least two seas at the north pole, Ligeia Mare and Kraken Mare. In addition, we also observe specular reflections from the shoreline or land, indicating the wet sidewalk effect or mudflat in other flybys. Wet sidewalk observations indicate a recent rainfall event causing diffuse specular reflection.These new observations help us understand more about the weather conditions and sea-wind interaction generating waves on the seas.

  19. HAMLET - A protein-lipid complex with broad tumoricidal activity.

    Science.gov (United States)

    Ho, James C S; Nadeem, Aftab; Svanborg, Catharina

    2017-01-15

    HAMLET (Human Alpha-lactalbumin Made LEthal to Tumor cells) is a tumoricidal protein-lipid complex with broad effects against cancer cells of different origin. The therapeutic potential is emphasized by a high degree of specificity for tumor tissue. Here we review early studies of HAMLET, in collaboration with the Orrenius laboratory, and some key features of the subsequent development of the HAMLET project. The early studies focused on the apoptotic response that accompanies death in HAMLET treated tumor cells and the role of mitochondria in this process. In subsequent studies, we have identified a sequence of interactions that starts with the membrane integration of HAMLET and the activation of ion fluxes followed by HAMLET internalization, progressive inhibition of MAPK kinases and GTPases and sorting of HAMLET to different cellular compartments, including the nuclei. Therapeutic efficacy of HAMLET has been demonstrated in animal models of glioblastoma, bladder cancer and intestinal cancer. In clinical studies, HAMLET has been shown to target skin papillomas and bladder cancers. The findings identify HAMLET as a new drug candidate with promising selectivity for cancer cells and a strong therapeutic potential.

  20. Broad Absorption Line Variability in Radio-Loud Quasars

    CERN Document Server

    Welling, C A; Brandt, W N; Capellupo, D M; Gibson, R R

    2014-01-01

    We investigate C IV broad absorption line (BAL) variability within a sample of 46 radio-loud quasars (RLQs), selected from SDSS/FIRST data to include both core-dominated (39) and lobe-dominated (7) objects. The sample consists primarily of high-ionization BAL quasars, and a substantial fraction have large BAL velocities or equivalent widths; their radio luminosities and radio-loudness values span ~2.5 orders of magnitude. We have obtained 34 new Hobby-Eberly Telescope (HET) spectra of 28 BAL RLQs to compare to earlier SDSS data, and we also incorporate archival coverage (primarily dual-epoch SDSS) for a total set of 78 pairs of equivalent width measurements for 46 BAL RLQs, probing rest-frame timescales of ~80-6000 d (median 500 d). In general, only modest changes in the depths of segments of absorption troughs are observed, akin to those seen in prior studies of BAL RQQs. Also similar to previous findings for RQQs, the RLQs studied here are more likely to display BAL variability on longer rest-frame timescal...