Sample records for michigan-tribe-nottawaseppi huron band

  1. MODELING PHYTOPLANKTON ABUNDANCE IN SAGINAW BAY, LAKE HURON: USING ARTIFICIAL NEURAL NETWORKS TO DISCERN FUNCTIONAL INFLUENCE

    E-Print Network [OSTI]

    MODELING PHYTOPLANKTON ABUNDANCE IN SAGINAW BAY, LAKE HURON: USING ARTIFICIAL NEURAL NETWORKS; phytoplankton Abbreviations: ANN, artificial neural network; ClŔ , chloride; DOC, dissolved organic carbon; Kd Phytoplankton abundance, as chl a, in Saginaw Bay, Lake Huron was modeled using arti- ficial neural networks

  2. MHK Projects/Lake Huron | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOf KilaueaInformationCygnet < MHKSound,IrontonKrotz SpringsHuron

  3. Temperature effects induced by climate change on the growth and consumption by salmonines in Lakes Michigan and Huron

    E-Print Network [OSTI]

    2014 Abstract We used bioenergetics models to investigate temperature effects induced by climate change (1964­1993) and projected in the future period (2043­2070). Bioenergetics simula- tions were run across change . Bioenergetics models . Salmonines . Lake michigan . Lake huron Introduction Following the global

  4. Fast Track Reservoir Modeling of Shale Formations in the Appalachian Basin. Application to Lower Huron Shale in Eastern Kentucky

    SciTech Connect (OSTI)

    Grujic, Ognjen; Mohaghegh, Shahab; Bromhal, Grant

    2010-07-01T23:59:59.000Z

    In this paper a fast track reservoir modeling and analysis of the Lower Huron Shale in Eastern Kentucky is presented. Unlike conventional reservoir simulation and modeling which is a bottom up approach (geo-cellular model to history matching) this new approach starts by attempting to build a reservoir realization from well production history (Top to Bottom), augmented by core, well-log, well-test and seismic data in order to increase accuracy. This approach requires creation of a large spatial-temporal database that is efficiently handled with state of the art Artificial Intelligence and Data Mining techniques (AI & DM), and therefore it represents an elegant integration of reservoir engineering techniques with Artificial Intelligence and Data Mining. Advantages of this new technique are a) ease of development, b) limited data requirement (as compared to reservoir simulation), and c) speed of analysis. All of the 77 wells used in this study are completed in the Lower Huron Shale and are a part of the Big Sandy Gas field in Eastern Kentucky. Most of the wells have production profiles for more than twenty years. Porosity and thickness data was acquired from the available well logs, while permeability, natural fracture network properties, and fracture aperture data was acquired through a single well history matching process that uses the FRACGEN/NFFLOW simulator package. This technology, known as Top-Down Intelligent Reservoir Modeling, starts with performing conventional reservoir engineering analysis on individual wells such as decline curve analysis and volumetric reserves estimation. Statistical techniques along with information generated from the reservoir engineering analysis contribute to an extensive spatio-temporal database of reservoir behavior. The database is used to develop a cohesive model of the field using fuzzy pattern recognition or similar techniques. The reservoir model is calibrated (history matched) with production history from the most recently drilled wells. The calibrated model is then further used for field development strategies to improve and enhance gas recovery.

  5. The Pennsylvania State University Marching Blue Band Blue Band Office

    E-Print Network [OSTI]

    Maroncelli, Mark

    The Pennsylvania State University Marching Blue Band Press Kit Blue Band Office 101 Blue Band Director vcc2@psu.edu orb1@psu.edu gad157@psu.edu (814) 865 - 3982 #12;History of the Blue Band The Marching Blue Band numbers 310 members which includes: 260 instrumentalists, 34 silks, 14 Touch of Blue

  6. Huron Schools | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEIHesperia, California:Project Jump to:WouldIndustrial

  7. Banded electromagnetic stator core

    DOE Patents [OSTI]

    Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

    1994-04-05T23:59:59.000Z

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figures.

  8. Banded electromagnetic stator core

    DOE Patents [OSTI]

    Fanning, A.W.; Gonzales, A.A.; Patel, M.R.; Olich, E.E.

    1996-06-11T23:59:59.000Z

    A stator core for an electromagnetic pump includes a plurality of circumferentially adjoining groups of flat laminations disposed about a common centerline axis and collectively defining a central bore and a discontinuous outer perimeter, with adjacent groups diverging radially outwardly to form V-shaped gaps. An annular band surrounds the groups and is predeterminedly tensioned to clamp together the laminations, and has a predetermined flexibility in a radial direction to form substantially straight bridge sections between the adjacent groups. 5 figs.

  9. Broad band waveguide spectrometer

    SciTech Connect (OSTI)

    Goldman, D.S.

    1995-08-29T23:59:59.000Z

    A spectrometer is disclosed for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the waveguide and a sample material. A tapered portion forms a part of the entry of the waveguide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis. 16 figs.

  10. Broad band waveguide spectrometer

    DOE Patents [OSTI]

    Goldman, Don S. (Folsom, CA)

    1995-01-01T23:59:59.000Z

    A spectrometer for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the wave guide and a sample material. A tapered portion forms a part of the entry of the wave guide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis.

  11. Broad-band beam buncher

    DOE Patents [OSTI]

    Goldberg, David A. (Walnut Creek, CA); Flood, William S. (Berkeley, CA); Arthur, Allan A. (Martinez, CA); Voelker, Ferdinand (Orinda, CA)

    1986-01-01T23:59:59.000Z

    A broad-band beam buncher is disclosed, comprising an evacuated housing, an electron gun therein for producing an electron beam, a buncher cavity having entrance and exit openings through which the beam is directed, grids across such openings, a source providing a positive DC voltage between the cavity and the electron gun, a drift tube through which the electron beam travels in passing through such cavity, grids across the ends of such drift tube, gaps being provided between the drift tube grids and the entrance and exit grids, a modulator for supplying an ultrahigh frequency modulating signal to the drift tube for producing velocity modulation of the electrons in the beam, a drift space in the housing through which the velocity modulated electron beam travels and in which the beam is bunched, and a discharge opening from such drift tube and having a grid across such opening through which the bunched electron beam is discharged into an accelerator or the like. The buncher cavity and the drift tube may be arranged to constitute an extension of a coaxial transmission line which is employed to deliver the modulating signal from a signal source. The extended transmission line may be terminated in its characteristic impedance to afford a broad-band response and the device as a whole designed to effect broad-band beam coupling, so as to minimize variations of the output across the response band.

  12. Bosonic condensation in a flat energy band

    E-Print Network [OSTI]

    Baboux, F; Jacqmin, T; Biondi, M; Lemaître, A; Gratiet, L Le; Sagnes, I; Schmidt, S; Türeci, H E; Amo, A; Bloch, J

    2015-01-01T23:59:59.000Z

    Flat bands are non-dispersive energy bands made of fully degenerate quantum states. Such bands are expected to support emergent phenomena with extraordinary spatial and temporal structures, as they strongly enhance the effect of any perturbation induced by disorder, dissipation or interactions. However, flat bands usually appear at energies above the ground state, preventing their study in systems in thermodynamic equilibrium. Here we use cavity polaritons to circumvent this issue. We engineer a flat band in a frustrated lattice of micro-pillar optical cavities. By taking advantage of the non-hermiticity of our system, we achieve for the first time bosonic condensation in a flat band. This allows revealing the peculiar effect of disorder in such band: The condensate fragments into highly localized modes, reflecting the elementary eigenstates produced by geometric frustration. This non-hermitian engineering of a bosonic flat band condensate offers a novel approach to studying coherent phases of light and matte...

  13. Low band gap polymers Organic Photovoltaics

    E-Print Network [OSTI]

    Low band gap polymers for Organic Photovoltaics Eva Bundgaard Ph.D. Dissertation Risř National Bundgaard Title: Low band gap polymers for Organic photovoltaics Department: The polymer department Report the area of organic photovoltaics are focusing on low band gap polymers, a type of polymer which absorbs

  14. Poisson statistics for random deformed band matrices with power law band width

    E-Print Network [OSTI]

    Vladimir Pchelin

    2015-05-25T23:59:59.000Z

    We show Poisson statistics for random band matrices which diagonal entries have Gaussian components. These components are possibly as small as $n^{-\\varepsilon}$. Particularly, our result is applicable for a band matrix cut from the GUE with the band width satisfying $w^{3.5}density of states (DOS) is obtained for complex deformed Gaussian band matrices with arbitrary $w$. A lower estimate of the DOS is also proven for arbitrary $w$ in a certain class of band matrices.

  15. For discussion only 2011 Huron Consulting Group

    E-Print Network [OSTI]

    3. Computer Bundles 4. Demand Management of Supplies 5. Single Email & Calendaring Platform and cooling costs · Fewer FTEs allocated towards server management · Decreased consumption of space by servers

  16. Huron, California: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEIHesperia, California:Project Jump to:WouldIndustrialCalifornia:

  17. Huron, Ohio: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetecGtel JumpCounty, Texas: Energy ResourcesMontana: EnergyOhio: Energy

  18. Photonic band gap structure simulator

    DOE Patents [OSTI]

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

    2006-10-03T23:59:59.000Z

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

  19. Possible chiral bands in {sup 194}Tl

    SciTech Connect (OSTI)

    Masiteng, P. L.; Ramashidzha, T. M.; Maliage, S. M.; Sharpey-Schafer, J. F.; Vymers, P. A. [iThemba LABS, P.O Box 722, 7129 (South Africa); University of the Western Cape, Private Bag X17, 7535 Bellville (South Africa); Lawrie, E. A.; Lawrie, J. J.; Bark, R. A.; Mullins, S. M.; Murray, S. H. T. [iThemba LABS, P.O Box 722, 7129 (South Africa); Kau, J.; Komati, F. [iThemba LABS, P.O Box 722, 7129 (South Africa); University of the North West, Private Bag X2046, 2735 Mafikeng (South Africa); Lindsay, R. [University of the Western Cape, Private Bag X17, 7535 Bellville (South Africa); Matamba, I. [University of Venda for Science and Technology, Thohoyandou (South Africa); Mutshena, P. [iThemba LABS, P.O Box 722, 7129 (South Africa); University of Venda for Science and Technology, Thohoyandou (South Africa); Zhang, Y. [iThemba LABS, P.O Box 722, 7129 (South Africa); University of Cape Town, Private Bag, 7701 Rondebosch (South Africa)

    2011-10-28T23:59:59.000Z

    High spin states in {sup 194}Tl, excited through the {sup 181}Ta({sup 18}O,5n) fusion evaporation reaction, were studied using the AFRODITE array at iThemba LABS. Candidate chiral bands built on the {pi}h{sub 9/2} x {nu}i{sub 13/2}{sup 1} configuration were found. Furthermore these bands were observed through a band crossing caused by the excitation of a {nu}i{sub 13/2} pair. Above the band crossing the excitation energies remain close, suggesting that chirality may persist for the four quasiparticle configuration too.

  20. Narrow band gap amorphous silicon semiconductors

    DOE Patents [OSTI]

    Madan, A.; Mahan, A.H.

    1985-01-10T23:59:59.000Z

    Disclosed is a narrow band gap amorphous silicon semiconductor comprising an alloy of amorphous silicon and a band gap narrowing element selected from the group consisting of Sn, Ge, and Pb, with an electron donor dopant selected from the group consisting of P, As, Sb, Bi and N. The process for producing the narrow band gap amorphous silicon semiconductor comprises the steps of forming an alloy comprising amorphous silicon and at least one of the aforesaid band gap narrowing elements in amount sufficient to narrow the band gap of the silicon semiconductor alloy below that of amorphous silicon, and also utilizing sufficient amounts of the aforesaid electron donor dopant to maintain the amorphous silicon alloy as an n-type semiconductor.

  1. Maximum Likelihood Sub-band Weighting for Robust Speech Recognition

    E-Print Network [OSTI]

    , bins of log filter-band energy (FBE) in each sub-band are multiplied with a weighting factor depending on the reliability of the sub-band. For each sub-band, zero padding is performed on the log FBE vector lengthening. For the DCT has the size of full-band FBE vector, the feature vector consists of the correlations across

  2. Dipole Bands in {sup 196}Hg

    SciTech Connect (OSTI)

    Lawrie, J. J.; Lawrie, E. A.; Newman, R. T.; Sharpey-Schafer, J. F.; Smit, F. D. [iThemba LABS, PO Box 722, Somerset West 7129 (South Africa); Msezane, B. [iThemba LABS, PO Box 722, Somerset West 7129 (South Africa); Physics Department, University of Zululand, Private Bag X1001, Kwadlangezwa 3886 (South Africa); Benatar, M.; Mabala, G. K.; Mutshena, K. P. [iThemba LABS, PO Box 722, Somerset West 7129 (South Africa); Physics Department, University of Cape Town, Rondebosch 7700 (South Africa); Federke, M.; Mullins, S. M. [Physics Department, University of Cape Town, Rondebosch 7700 (South Africa); Ncapayi, N. J.; Vymers, P. [iThemba LABS, PO Box 722, Somerset West 7129 (South Africa); Physics Department, University of the Western Cape, Private Bag X17, Belleville 7535 (South Africa)

    2011-10-28T23:59:59.000Z

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

  3. Behavioral/Systems/Cognitive Synchronous, Focally Modulated -Band Oscillations

    E-Print Network [OSTI]

    Graybiel, Ann M.

    , primarily synchronous -band voltage oscillations occur in the sensorimotor and frontal cortex of humansBehavioral/Systems/Cognitive Synchronous, Focally Modulated -Band Oscillations Characterize Local oscillations in the -frequency band ( 15­30Hz

  4. ISM band to U-NII band frequency transverter and method of frequency transversion

    DOE Patents [OSTI]

    Stepp, Jeffrey David (Grandview, MO); Hensley, Dale (Grandview, MO)

    2006-04-04T23:59:59.000Z

    A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz-6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

  5. ISM band to U-NII band frequency transverter and method of frequency transversion

    SciTech Connect (OSTI)

    Stepp, Jeffrey David (Grandview, MO); Hensley, Dale (Grandview, MO)

    2006-09-12T23:59:59.000Z

    A frequency transverter (10) and method for enabling bi-frequency dual-directional transfer of digitally encoded data on an RF carrier by translating between a crowded or otherwise undesirable first frequency band, such as the 2.4 GHz ISM band, and a less-crowded or otherwise desirable second frequency band, such as the 5.0 GHz 6.0 GHz U-NII band. In a preferred embodiment, the transverter (10) connects between an existing data radio (11) and its existing antenna (30), and comprises a bandswitch (12); an input RF isolating device (14); a transmuter (16); a converter (18); a dual output local oscillator (20); an output RF isolating device (22); and an antenna (24) tuned to the second frequency band. The bandswitch (12) allows for bypassing the transverter (10), thereby facilitating its use with legacy systems. The transmuter (14) and converter (16) are adapted to convert to and from, respectively, the second frequency band.

  6. Control Banding and Nanotechnology Synergist

    SciTech Connect (OSTI)

    Zalk, D; Paik, S

    2009-12-15T23:59:59.000Z

    The average Industrial Hygienist (IH) loves a challenge, right? Okay, well here is one with more than a few twists. We start by going through the basics of a risk assessment. You have some chemical agents, a few workers, and the makings of your basic exposure characterization. However, you have no occupational exposure limit (OEL), essentially no toxicological basis, and no epidemiology. Now the real handicap is that you cannot use sampling pumps, cassettes, tubes, or any of the media in your toolbox, and the whole concept of mass-to-dose is out the window, even at high exposure levels. Of course, by the title, you knew we were talking about nanomaterials (NM). However, we wonder how many IHs know that this topic takes everything you know about your profession and turns it upside down. It takes the very foundations that you worked so hard in college and in the field to master and pulls it out from underneath you. It even takes the gold standard of our profession, the quantitative science of exposure assessment, and makes it look pretty darn rusty. Now with NM there is the potential to get some aspect of quantitative measurements, but the instruments are generally very expensive and getting an appropriate workplace personal exposure measurement can be very difficult if not impossible. The potential for workers getting exposures, however, is very real, as evidenced by a recent publication reporting worker exposures to polyacrylate nanoparticles in a Chinese factory (Song et al. 2009). With something this complex and challenging, how does a concept as simple as Control Banding (CB) save the day? Although many IHs have heard of CB, most of their knowledge comes from its application in the COSHH Essentials toolkit. While there is conflicting published research on COSHH Essentials and its value for risk assessments, almost all of the experts agree that it can be useful when no OELs are available (Zalk and Nelson 2008). It is this aspect of CB, its utility with uncertainty, that attracted international NM experts to recommend this qualitative risk assessment approach for NM. However, since their CB recommendation was only in theory, we took on the challenge of developing a working toolkit, the CB Nanotool (see Zalk et al. 2009 and Paik et al. 2008), as a means to perform a risk assessment and protect researchers at the Lawrence Livermore National Laboratory. While it's been acknowledged that engineered NM have potentially endless benefits for society, it became clear to us that the very properties that make nanotechnology so useful to industry could also make them dangerous to humans and the environment. Among the uncertainties and unknowns with NM are: the contribution of their physical structure to their toxicity, significant differences in their deposition and clearance in the lungs when compared to their parent material (PM), a lack of agreement on the appropriate indices for exposure to NM, and very little background information on exposure scenarios or populations at risk. Part of this lack of background information can be traced to the lack of risk assessments historically performed in the industry, with a recent survey indicating that 65% of companies working with NM are not doing any kind of NM-specific risk assessment as they focus on traditional PM methods for IH (Helland et al. 2009). The good news is that the amount of peer-reviewed publications that address environmental, health and safety aspects of NM has been increasing over the last few years; however, the percentage of these that address practical methods to reduce exposure and protect workers is orders of magnitude lower. Our intent in developing the CB Nanotool was to create a simplified approach that would protect workers while unraveling the mysteries of NM for experts and non-experts alike. Since such a large part of the toxicological effects of both the physical and chemical properties of NM were unknown, not to mention changing logarithmically as new NM research continues growing, we needed to account for this lack of information as part of the CB Nano

  7. Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries. Band-Gap Engineering of Carbon Nanotubes with Grain Boundaries. Abstract: Structure and electronic properties of...

  8. System-level, Unified In-band and Out-of-band Dynamic Thermal Control

    E-Print Network [OSTI]

    of the decrease in computation capacity. Less studied are out-of-band techniques (e.g. CPU cooling fans [10]) that operate completely outside the critical performance path of an application. Out-of-band techniques cool system slowdowns or shutdowns. Techniques such as dynamically scaling down the voltage of the CPUs

  9. Energy Band Model Based on Effective Mass

    E-Print Network [OSTI]

    Viktor Ariel

    2012-09-06T23:59:59.000Z

    In this work, we demonstrate an alternative method of deriving an isotropic energy band model using a one-dimensional definition of the effective mass and experimentally observed dependence of mass on energy. We extend the effective mass definition to anti-particles and particles with zero rest mass. We assume an often observed linear dependence of mass on energy and derive a generalized non-parabolic energy-momentum relation. The resulting non-parabolicity leads to velocity saturation at high particle energies. We apply the energy band model to free relativistic particles and carriers in solid state materials and obtain commonly used dispersion relations and experimentally confirmed effective masses. We apply the model to zero rest mass particles in graphene and propose using the effective mass for photons. Therefore, it appears that the new energy band model based on the effective mass can be applied to relativistic particles and carriers in solid state materials.

  10. Band filling effects on temperature performance of intermediate band quantum wire solar cells

    SciTech Connect (OSTI)

    Kunets, Vas. P., E-mail: vkunets@uark.edu; Furrow, C. S.; Ware, M. E.; Souza, L. D. de; Benamara, M.; Salamo, G. J. [Institute for Nanoscience and Engineering, University of Arkansas, Fayetteville, Arkansas 72701 (United States); Mortazavi, M. [Department of Chemistry and Physics, University of Arkansas at Pine Bluff, Pine Bluff, Arkansas 71601 (United States)

    2014-08-28T23:59:59.000Z

    Detailed studies of solar cell efficiency as a function of temperature were performed for quantum wire intermediate band solar cells grown on the (311)A plane. A remotely doped one-dimensional intermediate band made of self-assembled In{sub 0.4}Ga{sub 0.6}As quantum wires was compared to an undoped intermediate band and a reference p-i-n GaAs sample. These studies indicate that the efficiencies of these solar cells depend on the population of the one-dimensional band by equilibrium free carriers. A change in this population by free electrons under various temperatures affects absorption and carrier transport of non-equilibrium carriers generated by incident light. This results in different efficiencies for both the doped and undoped intermediate band solar cells in comparison with the reference GaAs p-i-n solar cell device.

  11. UNIDENTIFIED INFRARED EMISSION BANDS: PAHs or MAONs?

    SciTech Connect (OSTI)

    Sun Kwok; Yong Zhang, E-mail: sunkwok@hku.hk [Department of Physics, University of Hong Kong, Pokfulam Road, Hong Kong (Hong Kong)

    2013-07-01T23:59:59.000Z

    We suggest that the carrier of the unidentified infrared emission (UIE) bands is an amorphous carbonaceous solid with mixed aromatic/aliphatic structures, rather than free-flying polycyclic aromatic hydrocarbon molecules. Through spectral fittings of the astronomical spectra of the UIE bands, we show that a significant amount of the energy is emitted by the aliphatic component, implying that aliphatic groups are an essential part of the chemical structure. Arguments in favor of an amorphous, solid-state structure rather than a gas-phase molecule as a carrier of the UIE are also presented.

  12. Carbon Monoxide bands in M dwarfs

    E-Print Network [OSTI]

    Yakiv V. Pavlenko; Hugh R. A. Jones

    2002-10-01T23:59:59.000Z

    We compare the observational and theoretical spectra of the $\\Delta v$ = 2 CO bands in a range of M dwarfs. We investigate the dependence of theoretical spectra on effective temperatures as well as carbon abundance. In general we find that the synthetic CO bands fit the observed data extremely well and are excellent diagnostics. In particular the synthetic spectra reasonably match observations and the best fit temperatures are similar to those found by empirical methods. We also examine the \\CDC isotopic ratio. We find that fundamental $^{13}$CO bands around 2.345 and 2.375 $\\mu$m are good discriminators for the \\CDC ratio in M dwarfs. The 2.375 $\\mu$m is more useful because it doesn't suffer such serious contamination by water vapour transitions. Our current dataset does not quite have the wavelength coverage to perform a reliable determination of the \\CDC ratio in M dwarfs. For this we recommend observing the region 2.31--2.40 $\\mu$m at a resolution of better than 1000. Alternatively the observational problems of contamination by water vapour at 2.345 $\\mu$m maybe solved by observing at resolutions of around 50000. We also investigated the possibility of using the $\\Delta v$ = 1 CO bands around 4.5 $\\mu$m. We find that the contamination due to water vapour is even more of a problem at these wavelengths.

  13. Shear banding in soft glassy materials

    E-Print Network [OSTI]

    Suzanne M. Fielding

    2014-08-20T23:59:59.000Z

    Many soft materials, including foams, dense emulsions, micro gel bead suspensions, star polymers, dense packing of surfactant onion micelles, and textured morphologies of liquid crystals, share the basic "glassy" features of structural disorder and metastability. These in turn give rise to several notable features in the low frequency shear rheology (deformation and flow properties) of these materials: in particular, the existence of a yield stress below which the material behaves like a solid, and above which it flows like a liquid. In the last decade, intense experimental activity has also revealed that these materials often display a phenomenon known as shear banding, in which the flow profile across the shear cell exhibits macroscopic bands of different viscosity. Two distinct classes of yield stress fluid have been identified: those in which the shear bands apparently persist permanently (for as long as the flow remains applied), and those in which banding arises only transiently during a process in which a steady flowing state is established out of an initial rest state (for example, in a shear startup or step stress experiment). After surveying the motivating experimental data, we describe recent progress in addressing it theoretically, using the soft glassy rheology model and a simple fluidity model. We also briefly place these theoretical approaches in the context of others in the literature, including elasto-plastic models, shear transformation zone theories, and molecular dynamics simulations. We discuss finally some challenges that remain open to theory and experiment alike.

  14. Kinematics analyses of Dodekapod Prakash Bande a

    E-Print Network [OSTI]

    Saha, Subir Kumar

    Kinematics analyses of Dodekapod Prakash Bande a , Martin Seibt b , Eckart Uhlmann b , S.K. Saha c. Tel.: +91 11 2659 1135; fax: +91 11 2658 2053. E-mail address: saha@mech.iitd.ernet.in (S.K. Saha

  15. Fabrication of photonic band gap materials

    DOE Patents [OSTI]

    Constant, Kristen (Ames, IA); Subramania, Ganapathi S. (Ames, IA); Biswas, Rana (Ames, IA); Ho, Kai-Ming (Ames, IA)

    2002-01-15T23:59:59.000Z

    A method for forming a periodic dielectric structure exhibiting photonic band gap effects includes forming a slurry of a nano-crystalline ceramic dielectric or semiconductor material and monodisperse polymer microspheres, depositing a film of the slurry on a substrate, drying the film, and calcining the film to remove the polymer microspheres therefrom. The film may be cold-pressed after drying and prior to calcining. The ceramic dielectric or semiconductor material may be titania, and the polymer microspheres may be polystyrene microspheres.

  16. Permanent magnet focused X-band photoinjector

    DOE Patents [OSTI]

    Yu, David U. L. (Rancho Palos Verdes, CA); Rosenzweig, James (Los Angeles, CA)

    2002-09-10T23:59:59.000Z

    A compact high energy photoelectron injector integrates the photocathode directly into a multicell linear accelerator with no drift space between the injection and the linac. High electron beam brightness is achieved by accelerating a tightly focused electron beam in an integrated, multi-cell, X-band rf linear accelerator (linac). The photoelectron linac employs a Plane-Wave-Transformer (PWT) design which provides strong cell-to-cell coupling, easing manufacturing tolerances and costs.

  17. The Zeeman effect in the G band

    E-Print Network [OSTI]

    H. Uitenbroek; E. Miller-Ricci; A. Asensio Ramos; J. Trujillo Bueno

    2004-01-22T23:59:59.000Z

    We investigate the possibility of measuring magnetic field strength in G-band bright points through the analysis of Zeeman polarization in molecular CH lines. To this end we solve the equations of polarized radiative transfer in the G band through a standard plane-parallel model of the solar atmosphere with an imposed magnetic field, and through a more realistic snapshot from a simulation of solar magneto-convection. This region of the spectrum is crowded with many atomic and molecular lines. Nevertheless, we find several instances of isolated groups of CH lines that are predicted to produce a measurable Stokes V signal in the presence of magnetic fields. In part this is possible because the effective Land\\'{e} factors of lines in the stronger main branch of the CH A$^{2}\\Delta$--X$^{2}\\Pi$ transition tend to zero rather quickly for increasing total angular momentum $J$, resulting in a Stokes $V$ spectrum of the G band that is less crowded than the corresponding Stokes $I$ spectrum. We indicate that, by contrast, the effective Land\\'{e} factors of the $R$ and $P$ satellite sub-branches of this transition tend to $\\pm 1$ for increasing $J$. However, these lines are in general considerably weaker, and do not contribute significantly to the polarization signal. In one wavelength location near 430.4 nm the overlap of several magnetically sensitive and non-sensitive CH lines is predicted to result in a single-lobed Stokes $V$ profile, raising the possibility of high spatial-resolution narrow-band polarimetric imaging. In the magneto-convection snapshot we find circular polarization signals of the order of 1% prompting us to conclude that measuring magnetic field strength in small-scale elements through the Zeeman effect in CH lines is a realistic prospect.

  18. Broad Band Photon Harvesting Biomolecules for Photovoltaics

    E-Print Network [OSTI]

    P. Meredith; B. J. Powell; J. Riesz; R. Vogel; D. Blake; I. Kartini; G. Will; S. Subianto

    2004-06-04T23:59:59.000Z

    We discuss the key principles of artificial photosynthesis for photovoltaic energy conversion. We demonstrate these principles by examining the operation of the so-called "dye sensitized solar cell" (DSSC) - a photoelectrochemical device which simulates the charge separation process across a nano-structured membrane that is characteristic of natural systems. These type of devices have great potential to challenge silicon semiconductor technology in the low cost, medium efficiency segment of the PV market. Ruthenium charge transfer complexes are currently used as the photon harvesting components in DSSCs. They produce a relatively broad band UV and visible response, but have long term stability problems and are expensive to manufacture. We suggest that a class of biological macromolecules called the melanins may be suitable replacements for the ruthenium complexes. They have strong, broad band absorption, are chemically and photochemically very stable, can be cheaply and easily synthesized, and are also bio-available and bio-compatible. We demonstrate a melanin-based regenerative solar cell, and discuss the key properties that are necessary for an effective broad band photon harvesting system.

  19. Highly Mismatched Alloys for Intermediate Band Solar Cells

    E-Print Network [OSTI]

    2005-01-01T23:59:59.000Z

    for Intermediate Band Solar Cells W. Walukiewicz 1 , K. M.single-junction intermediate band solar cells. Figure 5:conversion efficiency for a solar cell fabricated from a Zn

  20. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Wednesday, 26 March 2008 00:00 Prospective challengers to...

  1. Direct band gap narrowing in highly doped Ge

    E-Print Network [OSTI]

    Han, Zhaohong

    Direct band gap narrowing in highly doped n-type Ge is observed through photoluminescence measurements by determining the spectrum peak shift. A linear relationship between the direct band gap emission and carrier concentration ...

  2. FROM RUBBER BANDS TO RATIONAL MAPS RESEARCH REPORT

    E-Print Network [OSTI]

    Thurston, Dylan

    FROM RUBBER BANDS TO RATIONAL MAPS RESEARCH REPORT DYLAN P. THURSTON Dedicated to the memory-print, and surely has mistakes; please give comments! , elastic networks (rubber bands) at equilibrium within

  3. Quebec Recovery of White-Fronted Goose Banded in Greenland

    E-Print Network [OSTI]

    O. H. Hewitt Journal:  Bird Banding Volume:  19 Issue:  3 (July) Section:  General Notes Year:  1948 Pages:  124

  4. Arctic Tern Banded in Greenland, Recovered in Ontario

    E-Print Network [OSTI]

    T. M. Shortt Journal:  Bird Banding Volume:  20 Issue:  1 (January) Section:  General Notes Year:  1949 Pages:  50

  5. Excitation of Banded Whistler Waves in the Magnetosphere

    SciTech Connect (OSTI)

    Gary, S. Peter [Los Alamos National Laboratory; Liu, Kaijun [Los Alamos National Laboratory; Winske, Dan [Los Alamos National Laboratory

    2012-07-13T23:59:59.000Z

    Banded whistler waves can be generated by the whistler anisotropy instability driven by two bi-Maxwellian electron components with T{sub {perpendicular}}/T{sub {parallel}} > 1 at different T{sub {parallel}} For typical magnetospheric condition of 1 < {omega}{sub e}/{Omega}{sub e} < 5 in regions associated with strong chorus, upper-band waves can be excited by anisotropic electrons below {approx} 1 keV, while lower-band waves are excited by anisotropic electrons above {approx} 10 keV. Lower-band waves are generally field-aligned and substantially electromagnetic, while upper-band waves propagate obliquely and have quasi-electrostatic fluctuating electric fields. The quasi-electrostatic feature of upper-band waves suggests that they may be more easily identified in electric field observations than in magnetic field observations. Upper-band waves are liable to Landau damping and the saturation level of upperband waves is lower than lower-band waves, consistent with observations that lower-band waves are stronger than upper-band waves on average. The oblique propagation, the lower saturation level, and the more severe Landau damping together would make upper-band waves more tightly confined to the geomagnetic equator (|{lambda}{sub m}| < {approx}10{sup o}) than lower-band waves.

  6. FROM RUBBER BANDS TO RATIONAL MAPS RESEARCH REPORT

    E-Print Network [OSTI]

    Thurston, Dylan

    FROM RUBBER BANDS TO RATIONAL MAPS RESEARCH REPORT DYLAN P. THURSTON Dedicated to the memory and conformal surfaces with boundary, that let us on the one hand tell when one rubber band network is looser a circle of ideas, relating: , elastic networks (rubber bands) at equilibrium within a graph, , extremal

  7. Anisotropy of strong pinning in multi-band superconductors

    E-Print Network [OSTI]

    Boyer, Edmond

    pinning in multi-band superconductors 2 1. Introduction The multi-band nature of superconductivity in iron the anisotropy of superconducting parameters in the iron-based superconductors. In particular, Kidzun et al. [23Anisotropy of strong pinning in multi-band superconductors C.J. van der Beek, M. Konczykowski

  8. absorption band profiles: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    absorption band profiles First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Band profiles and band...

  9. Semiconductor heterojunction band offsets and charge neutrality

    E-Print Network [OSTI]

    Lee, Chomsik

    1989-01-01T23:59:59.000Z

    = 33&Pb = 3 3&PAB = 35 1 . aI M 0 A 0. ? 1 2. 0. Energy(eV) 1 2. 0 0. ? 1 0. Energy(eV) 1 2. Figure 4. 4. Local density of states, parameters for this case are s, = ? 7, s?= 1, s, = l&sp 7~Pa = 4~A = 4)DAB ? .35. -12. 0. Energy(eV) 0... Signature of APS Member Roland E. Allen Department of Physics'- Texas A&M University ' College Station, TX 77843 s p ~ CX3 SEMICONDUCTOR HETEROJUNCTION BAND OFFSETS AND CHARGE NEUTRALITY A Thesis by CHOMSIK LEE Submitted to the Oflice of Graduate...

  10. Universal EUV in-band intensity detector

    DOE Patents [OSTI]

    Berger, Kurt W.

    2004-08-24T23:59:59.000Z

    Extreme ultraviolet light is detected using a universal in-band detector for detecting extreme ultraviolet radiation that includes: (a) an EUV sensitive photodiode having a diode active area that generates a current responsive to EUV radiation; (b) one or more mirrors that reflects EUV radiation having a defined wavelength(s) to the diode active area; and (c) a mask defining a pinhole that is positioned above the diode active area, wherein EUV radiation passing through the pinhole is restricted substantially to illuminating the diode active area.

  11. Hybrid Band effects program (Lockheed Martin shared vision CRADA)

    SciTech Connect (OSTI)

    Bacon, L. D.

    2012-03-01T23:59:59.000Z

    Hybrid Band{trademark} (H-band) is a Lockheed Martin Missiles and Fire Control (LMMFC) designation for a specific RF modulation that causes disruption of select electronic components and circuits. H-Band enables conventional high-power microwave (HPM) effects (with a center frequency of 1 to 2 GHz, for example) using a higher frequency carrier signal. The primary technical objective of this project was to understand the fundamental physics of Hybrid Band{trademark} Radio Frequency effects on electronic systems. The follow-on objective was to develop and validate a Hybrid Band{trademark} effects analysis process.

  12. Puzzling Phenomenon of Diffuse Interstellar Bands

    E-Print Network [OSTI]

    B. Wszolek

    2007-12-10T23:59:59.000Z

    The discovery of the first diffuse interstellar bands (DIBs) dates back to the pioneering years of stellar spectroscopy. Today, we know about 300 absorption structures of this kind. There exists a great variety of the profiles and intensities of DIBs, so they can not be readily described, classified or characterized. To the present day no reliable identification of the DIBs' carriers has been found. Many carriers of DIBs have been proposed over the years. They ranged from dust grains to free molecules of different kinds, and to more exotic specimens, like hydrogen negative ion. Unfortunately, none of them is responsible for observed DIBs. Furthermore, it was shown that a single carrier cannot be responsible for all known DIBs. It is hard to estimate how many carriers can participate in producing these bands. The problem is further complicated by the fact that to this day it is still impossible to find any laboratory spectrum of any substance which would match the astrophysical spectra. Here, a historical outline concerning DIBs is followed by a brief description of their whole population. Then, a special attention is focused on the procedures trying to extract spectroscopic families within the set of all known DIBs.

  13. Red Band Needle Blight Programme Red Band Needle Blight of Pine Programme Group

    E-Print Network [OSTI]

    and that the private 1 | Paper 1 - Minutes | Debbie Erskine | 23/01/2009 #12;Red Band Needle Blight Programme Group Group England Working Group Wales Working Group RBNB Operational GB Working Group (including private Groups would only meet on an ad hoc basis and the structure was agreed. Action: Jim/Roddie to re

  14. Wide band stepped frequency ground penetrating radar

    DOE Patents [OSTI]

    Bashforth, M.B.; Gardner, D.; Patrick, D.; Lewallen, T.A.; Nammath, S.R.; Painter, K.D.; Vadnais, K.G.

    1996-03-12T23:59:59.000Z

    A wide band ground penetrating radar system is described embodying a method wherein a series of radio frequency signals is produced by a single radio frequency source and provided to a transmit antenna for transmission to a target and reflection therefrom to a receive antenna. A phase modulator modulates those portions of the radio frequency signals to be transmitted and the reflected modulated signal is combined in a mixer with the original radio frequency signal to produce a resultant signal which is demodulated to produce a series of direct current voltage signals, the envelope of which forms a cosine wave shaped plot which is processed by a Fast Fourier Transform Unit 44 into frequency domain data wherein the position of a preponderant frequency is indicative of distance to the target and magnitude is indicative of the signature of the target. 6 figs.

  15. Wide band stepped frequency ground penetrating radar

    DOE Patents [OSTI]

    Bashforth, Michael B. (Buellton, CA); Gardner, Duane (Santa Maria, CA); Patrick, Douglas (Santa Maria, CA); Lewallen, Tricia A. (Ventura, CA); Nammath, Sharyn R. (Santa Barbara, CA); Painter, Kelly D. (Goleta, CA); Vadnais, Kenneth G. (Alexandria, VA)

    1996-01-01T23:59:59.000Z

    A wide band ground penetrating radar system (10) embodying a method wherein a series of radio frequency signals (60) is produced by a single radio frequency source (16) and provided to a transmit antenna (26) for transmission to a target (54) and reflection therefrom to a receive antenna (28). A phase modulator (18) modulates those portion of the radio frequency signals (62) to be transmitted and the reflected modulated signal (62) is combined in a mixer (34) with the original radio frequency signal (60) to produce a resultant signal (53) which is demodulated to produce a series of direct current voltage signals (66) the envelope of which forms a cosine wave shaped plot (68) which is processed by a Fast Fourier Transform unit 44 into frequency domain data (70) wherein the position of a preponderant frequency is indicative of distance to the target (54) and magnitude is indicative of the signature of the target (54).

  16. Band terminations in density functional theory

    E-Print Network [OSTI]

    A. V. Afanasjev

    2009-02-01T23:59:59.000Z

    The analysis of the terminating bands has been performed in the relativistic mean field framework. It was shown that nuclear magnetism provides an additional binding to the energies of the specific configuration and this additional binding increases with spin and has its {\\it maximum} exactly at the terminating state. This suggests that the terminating states can be an interesting probe of the time-odd mean fields {\\it provided that other effects can be reliably isolated.} Unfortunately, a reliable isolation of these effects is not that simple: many terms of the density functional theories contribute into the energies of the terminating states and the deficiencies in the description of those terms affect the result. The recent suggestion \\cite{ZSW.05} that the relative energies of the terminating states in the $N \

  17. Eastern Band of Cherokee Strategic Energy Plan

    SciTech Connect (OSTI)

    Souther Carolina Institute of energy Studies-Robert Leitner

    2009-01-30T23:59:59.000Z

    The Eastern Band of Cherokee Indians was awarded a grant under the U.S. Department of Energy Tribal Energy Program (TEP) to develop a Tribal Strategic Energy Plan (SEP). The grant, awarded under the “First Steps” phase of the TEP, supported the development of a SEP that integrates with the Tribe’s plans for economic development, preservation of natural resources and the environment, and perpetuation of Tribal heritage and culture. The Tribe formed an Energy Committee consisting of members from various departments within the Tribal government. This committee, together with its consultant, the South Carolina Institute for Energy Studies, performed the following activities: • Develop the Tribe’s energy goals and objectives • Establish the Tribe’s current energy usage • Identify available renewable energy and energy efficiency options • Assess the available options versus the goals and objectives • Create an action plan for the selected options

  18. Band gap engineering at a semiconductor - crystalline oxide interface

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Moghadam, Jahangir-Moghadam; Shen, Xuan; Chrysler, Matthew; Ahmadi-Majlan, Kamyar; Su, Dong; Ngai, Joseph H.

    2015-03-01T23:59:59.000Z

    The epitaxial growth of crystalline oxides on semiconductors provides a pathway to introduce new functionalities to semiconductor devices. Key to integrating the functionalities of oxides onto semiconductors is controlling the band alignment at interfaces between the two materials. Here we apply principles of band gap engineering traditionally used at heterojunctions between conventional semiconductors to control the band offset between a single crystalline oxide and a semiconductor. Reactive molecular beam epitaxy is used to realize atomically abrupt and structurally coherent interfaces between SrZrxTi1-xO? and Ge, in which the band gap of the former is enhanced with Zr content x. We presentmore »structural and electrical characterization of SrZrxTi1-xO?-Ge heterojunctions and demonstrate a type-I band offset can be achieved. These results demonstrate that band gap engineering can be exploited to realize functional semiconductor crystalline oxide heterojunctions.« less

  19. acoustic band gaps: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    type of phononic crystals manufactured Institute of Physics. DOI: 10.10631.2167794 The propagation of acoustic waves in periodic composite Deymier, Pierre 2 Acoustic band gap...

  20. Substrate-Induced Band-Gap Opening in Epitaxial Graphene

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Substrate-Induced Band-Gap Opening in Epitaxial Graphene Print Prospective challengers to silicon, the long-reigning king of semiconductors for computer chips and other electronic...

  1. Engineering the Electronic Band Structure for Multiband Solar Cells

    SciTech Connect (OSTI)

    Lopez, N.; Reichertz, L.A.; Yu, K.M.; Campman, K.; Walukiewicz, W.

    2010-07-12T23:59:59.000Z

    Using the unique features of the electronic band structure of GaNxAs1-x alloys, we have designed, fabricated and tested a multiband photovoltaic device. The device demonstrates an optical activity of three energy bands that absorb, and convert into electrical current, the crucial part of the solar spectrum. The performance of the device and measurements of electroluminescence, quantum efficiency and photomodulated reflectivity are analyzed in terms of the Band Anticrossing model of the electronic structure of highly mismatched alloys. The results demonstrate the feasibility of using highly mismatched alloys to engineer the semiconductor energy band structure for specific device applications.

  2. Diffuse interstellar bands in M33

    E-Print Network [OSTI]

    Smith, Keith T; Evans, Christopher J; Cox, Nick L J; Sarre, Peter J

    2013-01-01T23:59:59.000Z

    We present the first sample of diffuse interstellar bands (DIBs) in the nearby galaxy M33. Studying DIBs in other galaxies allows the behaviour of the carriers to be examined under interstellar conditions which can be quite different from those of the Milky Way, and to determine which DIB properties can be used as reliable probes of extragalactic interstellar media. Multi-object spectroscopy of 43 stars in M33 has been performed using Keck/DEIMOS. The stellar spectral types were determined and combined with literature photometry to determine the M33 reddenings E(B-V)_M33. Equivalent widths or upper limits have been measured for the {\\lambda}5780 DIB towards each star. DIBs were detected towards 20 stars, demonstrating that their carriers are abundant in M33. The relationship with reddening is found to be at the upper end of the range observed in the Milky Way. The line of sight towards one star has an unusually strong ratio of DIB equivalent width to E(B-V)_M33, and a total of seven DIBs were detected towards...

  3. Intermediate Band Properties of Femtosecond-Laser Hyperdoped Silicon

    E-Print Network [OSTI]

    Mazur, Eric

    . The high concentration of dopants forms an intermediate band (IB), instead of discrete energy levels exhibits broad-band light absorption to wavelengths deep below the corresponding bandgap energy of silicon) using secondary ion mass spectrometry. By varying the pressure of SF6, we find that the surface adsorbed

  4. Band excitation method applicable to scanning probe microscopy

    DOE Patents [OSTI]

    Jesse, Stephen; Kalinin, Sergei V

    2013-05-28T23:59:59.000Z

    Methods and apparatus are described for scanning probe microscopy. A method includes generating a band excitation (BE) signal having finite and predefined amplitude and phase spectrum in at least a first predefined frequency band; exciting a probe using the band excitation signal; obtaining data by measuring a response of the probe in at least a second predefined frequency band; and extracting at least one relevant dynamic parameter of the response of the probe in a predefined range including analyzing the obtained data. The BE signal can be synthesized prior to imaging (static band excitation), or adjusted at each pixel or spectroscopy step to accommodate changes in sample properties (adaptive band excitation). An apparatus includes a band excitation signal generator; a probe coupled to the band excitation signal generator; a detector coupled to the probe; and a relevant dynamic parameter extractor component coupled to the detector, the relevant dynamic parameter extractor including a processor that performs a mathematical transform selected from the group consisting of an integral transform and a discrete transform.

  5. Band excitation method applicable to scanning probe microscopy

    DOE Patents [OSTI]

    Jesse, Stephen (Knoxville, TN) [Knoxville, TN; Kalinin, Sergei V. (Knoxville, TN) [Knoxville, TN

    2010-08-17T23:59:59.000Z

    Methods and apparatus are described for scanning probe microscopy. A method includes generating a band excitation (BE) signal having finite and predefined amplitude and phase spectrum in at least a first predefined frequency band; exciting a probe using the band excitation signal; obtaining data by measuring a response of the probe in at least a second predefined frequency band; and extracting at least one relevant dynamic parameter of the response of the probe in a predefined range including analyzing the obtained data. The BE signal can be synthesized prior to imaging (static band excitation), or adjusted at each pixel or spectroscopy step to accommodate changes in sample properties (adaptive band excitation). An apparatus includes a band excitation signal generator; a probe coupled to the band excitation signal generator; a detector coupled to the probe; and a relevant dynamic parameter extractor component coupled to the detector, the relevant dynamic parameter extractor including a processor that performs a mathematical transform selected from the group consisting of an integral transform and a discrete transform.

  6. A multi-band phase-locked loop frequency synthesizer

    E-Print Network [OSTI]

    Palermo, Samuel Michael

    1999-01-01T23:59:59.000Z

    to switch to different bands of operation. The multi-band PLL frequency synthesizer is implemented in a standard 1.2[]m CMOS technology using a 2.7V supply. The frequency synthesizer has a measured frequency range of 111 to 290MHz with phase noise up to -96d...

  7. V Concurs de Bandes de la UPF BASES GENERALS

    E-Print Network [OSTI]

    Geffner, Hector

    V Concurs de Bandes de la UPF BASES GENERALS requisits generals: Podran participar-hi tots els comunitat universitŕria de la UPF. inscripció: Les bandes que es presentin a concurs lliuraran al Punt d i la política de privacitat, de manera que exoneren la UPF de qualsevol responsabilitat derivada d

  8. K-BAND RADIO FREQUENCY INTERFERENCE SURVEY OF SOUTHEASTERN MICHIGAN

    E-Print Network [OSTI]

    Ruf, Christopher

    K-BAND RADIO FREQUENCY INTERFERENCE SURVEY OF SOUTHEASTERN MICHIGAN Shannon Curry1 , Michael Ahlers University of Michigan 2455 Hayward St. Ann Arbor, MI 48109-2143 USA cruf@umich.edu 2 DTU Space Technical resolution. A K-Band airborne version has been built and flown across southeast Michigan. A kurtosis detector

  9. SEMIEMPIRICAL MOLECULAR ORBITAL CALCULATIONS OF BAND GAPS OF CONJUGATED POLYMERS

    E-Print Network [OSTI]

    Goddard III, William A.

    SEMI­EMPIRICAL MOLECULAR ORBITAL CALCULATIONS OF BAND GAPS OF CONJUGATED POLYMERS Tahir Cagin Research and Development Center, Materials Labarotory, Polymer Branch, Wright Patterson AFB, Ohio 45433 geometries and energy band gaps of conjugated polymers. In this study, we used a modified version of semi

  10. absorption band substructure: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    absorption band substructure First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 THE ABSORPTION BAND EDGE...

  11. Nitrogen Dynamics in Sandy Freshwater Sediments (Saginaw Bay, Lake Huron)

    E-Print Network [OSTI]

    of added 15NH4 + from lake water passing over dark sediment cores. Sediment-water fluxes of nitrogen at the sediment- water interface is derived from ammonium pro- duced from organic matter mineralization in surface ABSTRACT. Sediment-water nitrogen fluxes and transformations were examined at two sites in Sagi- naw Bay

  12. Huron County, Ohio: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, search OpenEIHesperia, California:Project Jump to:WouldIndustrial ParkOhio:

  13. Huron County, Michigan: Energy Resources | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdfGetecGtel JumpCounty, Texas: Energy ResourcesMontana: Energy

  14. Port Huron, MI Liquefied Natural Gas Exports (Million Cubic Feet)

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5 Tables July 1996 Energy Information Administration Office ofthroughYear Jan Feb Mar AprYear JanPricePrice5,594.9DecadeDecade(Million

  15. First principles investigation of scaling trends of zirconium silicate interface band offsets

    E-Print Network [OSTI]

    Dutton, Robert W.

    First principles investigation of scaling trends of zirconium silicate interface band offsets out to investigate the scaling trends of band offsets at model silicon/zirconium silicate interfaces. Owing to the d character of zirconium silicate conduction bands, the band gap and band offset are shown

  16. Observation of excitonic and band-to-band behavior in ordered InGaP{sub 2} alloys

    SciTech Connect (OSTI)

    Jones, E.D.; Follstaedt, D.M.; Lee, H.; Nelson, J.S.; Schneider, R.P. Jr. [Sandia National Labs., Albuquerque, NM (United States); Alonso, R.G.; Horner, G.S.; Machol, J.; Mascarenhas, A. [National Renewable Energy Lab., Golden, CO (United States)

    1994-09-01T23:59:59.000Z

    Photoluminescence measurements on ordered InGaP{sub 2} were studied as a function of temperature, laser power density, and magnetic field. The temperature varied between 1.4 and 300 K, the laser power densities ranged from 10 nW/cm{sup 2} to 20 W/cm{sup 2}, and the maximum magnetic field was 13.6 T. The data show both excitonic and band-to-band behavior, depending upon the incident laser power density. A consistent interpretation of all data leads to a type-II valence-band offset between the ordered domains.

  17. angstrom extinction band: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Galactic extinction curve, which implies that the properties of dust in the extragalactic enviroment are similar to those of the Milky Way. The ratio of the total V band extinction...

  18. Feasibility of band gap engineering of pyrite FeS?

    E-Print Network [OSTI]

    Sun, Ruoshi

    We use first-principles computations to investigate whether the band gap of pyrite FeS? can be increased by alloying in order to make it a more effective photovoltaic material. In addition to the isostructural compounds ...

  19. Band gap engineering strategy via polarization rotation in perovskite ferroelectrics

    SciTech Connect (OSTI)

    Wang, Fenggong, E-mail: fenggong@sas.upenn.edu; Grinberg, Ilya; Rappe, Andrew M., E-mail: rappe@sas.upenn.edu [The Makineni Theoretical Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104–6323 (United States)

    2014-04-14T23:59:59.000Z

    We propose a strategy to engineer the band gaps of perovskite oxide ferroelectrics, supported by first principles calculations. We find that the band gaps of perovskites can be substantially reduced by as much as 1.2?eV through local rhombohedral-to-tetragonal structural transition. Furthermore, the strong polarization of the rhombohedral perovskite is largely preserved by its tetragonal counterpart. The B-cation off-center displacements and the resulting enhancement of the antibonding character in the conduction band give rise to the wider band gaps of the rhombohedral perovskites. The correlation between the structure, polarization orientation, and electronic structure lays a good foundation for understanding the physics of more complex perovskite solid solutions and provides a route for the design of photovoltaic perovskite ferroelectrics.

  20. Global estimation of precipitation using opaque microwave bands

    E-Print Network [OSTI]

    Chen, Frederick Wey-Min, 1975-

    2004-01-01T23:59:59.000Z

    This thesis describes the use of opaque microwave bands for global estimation of precipitation rate. An algorithm was developed for estimating instantaneous precipitation rate for the Advanced Microwave Sounding Unit (AMSU) ...

  1. Substrate-induced band gap opening in epitaxial graphene

    E-Print Network [OSTI]

    2008-01-01T23:59:59.000Z

    H.A. Electronic states of graphene nanoribbons studied withS.G. Louie. Energy gaps in graphene nanoribbons. Phys. Rev.band-gap engineering of graphene nanoribbons. Phys. Rev.

  2. Direct observation of a dispersionless impurity band in hydrogenated graphene

    E-Print Network [OSTI]

    Haberer, D.

    We show with angle-resolved photoemission spectroscopy that a new energy band appears in the electronic structure of electron-doped hydrogenated monolayer graphene (H-graphene). Its occupation can be controlled with the ...

  3. Multi-band OFDM UWB receiver with narrowband interference suppression 

    E-Print Network [OSTI]

    Kelleci, Burak

    2009-05-15T23:59:59.000Z

    A multi band orthogonal frequency division multiplexing (MB-OFDM) compatible ultra wideband (UWB) receiver with narrowband interference (NBI) suppression capability is presented. The average transmit power of UWB system ...

  4. New description of the doublet bands in doubly odd nuclei

    SciTech Connect (OSTI)

    Ganev, H. G.; Georgieva, A. I. [Institute of Nuclear Research and Nuclear Energy, Bulgarian Academy of Sciences, Sofia 1784 (Bulgaria); Brant, S. [Department of Physics, Faculty of Science, University of Zagreb, 10000 Zagreb (Croatia); Ventura, A. [Ente per le Nuove tecnologie, l'Energia e l'Ambiente, I-40129 Bologna and Istituto Nazionale di Fisica Nucleare, Sezione di Bologna (Italy)

    2009-04-15T23:59:59.000Z

    The experimentally observed {delta}I=1 doublet bands in some odd-odd nuclei are analyzed within the orthosymplectic extension of the interacting vector boson model (IVBM). A new, purely collective interpretation of these bands is given on the basis of the obtained boson-fermion dynamical symmetry of the model. It is illustrated by its application to three odd-odd nuclei from the A{approx}130 region, namely {sup 126}Pr, {sup 134}Pr, and {sup 132}La. The theoretical predictions for the energy levels of the doublet bands as well as E2 and M1 transition probabilities between the states of the yrast band in the last two nuclei are compared with experiment and the results of other theoretical approaches. The obtained results reveal the applicability of the orthosymplectic extension of the IVBM.

  5. Comparative cytotaxonomy in the tribe Bovini studied by banding techniques

    E-Print Network [OSTI]

    Rich, Donna Carol

    1986-01-01T23:59:59.000Z

    Committee: Dr. James E. Womack Chromosomes of eight species of the tribe Bovini were studied by G ? banding, C ? banding and silver staining techniques. The results of this comparative cytogenetic study support the theory that Robertsonian fusion... in the tribe Bovini whose species appear to differ by a series of centromeric fusions. The phylogenetic tree derived from the cytogenetic data of this study is not consistent with morphological and behavioral trees previously described for the tribe Bovini...

  6. X-Band Photonic Band-Gap Accelerator Structure Breakdown Experiment

    SciTech Connect (OSTI)

    Marsh, Roark A.; /MIT /MIT /NIFS, Gifu /JAERI, Kyoto /LLNL, Livermore; Shapiro, Michael A.; Temkin, Richard J.; /MIT; Dolgashev, Valery A.; Laurent, Lisa L.; Lewandowski, James R.; Yeremian, A.Dian; Tantawi, Sami G.; /SLAC

    2012-06-11T23:59:59.000Z

    In order to understand the performance of photonic band-gap (PBG) structures under realistic high gradient, high power, high repetition rate operation, a PBG accelerator structure was designed and tested at X band (11.424 GHz). The structure consisted of a single test cell with matching cells before and after the structure. The design followed principles previously established in testing a series of conventional pillbox structures. The PBG structure was tested at an accelerating gradient of 65 MV/m yielding a breakdown rate of two breakdowns per hour at 60 Hz. An accelerating gradient above 110 MV/m was demonstrated at a higher breakdown rate. Significant pulsed heating occurred on the surface of the inner rods of the PBG structure, with a temperature rise of 85 K estimated when operating in 100 ns pulses at a gradient of 100 MV/m and a surface magnetic field of 890 kA/m. A temperature rise of up to 250 K was estimated for some shots. The iris surfaces, the location of peak electric field, surprisingly had no damage, but the inner rods, the location of the peak magnetic fields and a large temperature rise, had significant damage. Breakdown in accelerator structures is generally understood in terms of electric field effects. These PBG structure results highlight the unexpected role of magnetic fields in breakdown. The hypothesis is presented that the moderate level electric field on the inner rods, about 14 MV/m, is enhanced at small tips and projections caused by pulsed heating, leading to breakdown. Future PBG structures should be built to minimize pulsed surface heating and temperature rise.

  7. A Study of the Process of Commissioning New Music for the Concert Band

    E-Print Network [OSTI]

    McAllister, James

    2012-08-31T23:59:59.000Z

    This study examined the process of commissioning a new composition for the concert band. Composer Brian Balmages was commissioned to write a piece for concert band that had standard band instrumentation and was of Grade IV difficulty. The Temple...

  8. Shear band dynamics from a mesoscopic modeling of plasticity

    E-Print Network [OSTI]

    E. A. Jagla

    2010-06-07T23:59:59.000Z

    The ubiquitous appearance of regions of localized deformation (shear bands) in different kinds of disordered materials under shear is studied in the context of a mesoscopic model of plasticity. The model may or may not include relaxational (aging) effects. In the absence of relaxational effects the model displays a monotonously increasing dependence of stress on strain-rate, and stationary shear bands do not occur. However, in start up experiments transient (although long lived) shear bands occur, that widen without bound in time. I investigate this transient effect in detail, reproducing and explaining a t^1/2 law for the thickness increase of the shear band that has been obtained in atomistic numerical simulations. Relaxation produces a negative sloped region in the stress vs. strain-rate curve that stabilizes the formation of shear bands of a well defined width, which is a function of strain-rate. Simulations at very low strain-rates reveal a non-trivial stick-slip dynamics of very thin shear bands that has relevance in the study of seismic phenomena. In addition, other non-stationary processes, such as stop-and-go, or strain-rate inversion situations display a phenomenology that matches very well the results of recent experimental studies.

  9. Strategic Energy Management Plan for the Santa Ynez Band of Chumash...

    Office of Scientific and Technical Information (OSTI)

    Strategic Energy Management Plan for the Santa Ynez Band of Chumash Indians Re-direct Destination: This plan outlines the Santa Ynez Band of Chumash Indians' comprehensive energy...

  10. Scent marking in wild banded mongooses: 2. Intrasexual overmarking and competition between males

    E-Print Network [OSTI]

    RĂĽedi, Peter

    Scent marking in wild banded mongooses: 2. Intrasexual overmarking and competition between males on wild banded mongooses, Mungos mungo, suggests that overmarking may primarily affect behavioural mating

  11. Robotic end gripper with a band member to engage object

    DOE Patents [OSTI]

    Pollard, R.E.; Robinson, S.C.; Thompson, W.F.; Couture, S.A.; Sutton, B.J.

    1994-05-10T23:59:59.000Z

    An end effector for use with robotic arms and like devices is described that utilizes a flexible band to draw an object against an anvil having a concave surface. One typical convex surface is created by a V-block, with an apex of the V being centrally located. If an object to be grasped is fragile, the contour of the concave surface closely matches the surface of the object. Typically the movement of the band is effected by a linear actuator, with the anvil remaining fixed relative to a support base. Several embodiments are described that utilize variations in drawing the band toward the anvil, with one of these embodiments described in detail in the form of a fabricated unit. One embodiment includes a cover element that can be moved over an object after the grasping thereof, with this cover potentially serving various functions. Movement of the cover can be effected with a second linear actuator. 8 figures.

  12. Robotic end gripper with a band member to engage object

    DOE Patents [OSTI]

    Pollard, Roy E. (Maryville, TN); Robinson, Samuel C. (Knoxville, TN); Thompson, William F. (Oak Ridge, TN); Couture, Scott A. (Knoxville, TN); Sutton, Bill J. (Powell, TN)

    1994-01-01T23:59:59.000Z

    An end effector for use with robotic arms and like devices that utilizes a flexible band to draw an object against an anvil having a concave surface. One typical convex surface is created by a V-block, with an apex of the V being centrally located. If an object to be grasped is fragile, the contour of the concave surface closely matches the surface of the object. Typically the movement of the band is effected by a linear actuator, with the anvil remaining fixed relative to a support base. Several embodiments are described that utilize variations in drawing the band toward the anvil, with one of these embodiments described in detail in the form of a fabricated unit. One embodiment includes a cover element that can be moved over an object after the grasping thereof, with this cover potentially serving various functions. Movement of the cover can be effected with a second linear actuator.

  13. Numerical method for shear bands in ductile metal with inclusions

    SciTech Connect (OSTI)

    Plohr, Jee Yeon N [Los Alamos National Laboratory; Plohr, Bradley J [Los Alamos National Laboratory

    2010-01-01T23:59:59.000Z

    A numerical method for mesoscale simulation of high strain-rate loading of ductile metal containing inclusions is described. Because of small-scale inhomogeneities, such a composite material is prone to localized shear deformation (adiabatic shear bands). The modeling framework is the Generalized Method of Cells of Paley and Aboudi [Mech. Materials, vol. 14, pp. /27-139, 1992], which ensures that the micromechanical response of the material is reflected in the behavior of the composite at the mesoscale. To calculate the effective plastic strain rate when shear bands are present, the analytic and numerical analysis of shear bands by Glimm, Plohr, and Sharp [Mech. Materials, vol. 24, pp. 31-41, 1996] is adapted and extended.

  14. Status Report and Proposal Concerning the Supply of Depleted Uranium Metal Bands for a Particle Detector

    E-Print Network [OSTI]

    1980-01-01T23:59:59.000Z

    Status Report and Proposal Concerning the Supply of Depleted Uranium Metal Bands for a Particle Detector

  15. Electronic band structure of magnetic bilayer graphene superlattices

    SciTech Connect (OSTI)

    Pham, C. Huy; Nguyen, T. Thuong [Theoretical and Computational Physics Department, Institute of Physics, VAST, 10 Dao Tan, Ba Dinh Distr., Hanoi 10000 (Viet Nam); SISSA/International School for Advanced Study, Via Bonomea 265, I-34136 Trieste (Italy); Nguyen, V. Lien, E-mail: nvlien@iop.vast.ac.vn [Theoretical and Computational Physics Department, Institute of Physics, VAST, 10 Dao Tan, Ba Dinh Distr., Hanoi 10000 (Viet Nam); Institute for Bio-Medical Physics, 109A Pasteur, 1st Distr., Hochiminh City (Viet Nam)

    2014-09-28T23:59:59.000Z

    Electronic band structure of the bilayer graphene superlattices with ?-function magnetic barriers and zero average magnetic flux is studied within the four-band continuum model, using the transfer matrix method. The periodic magnetic potential effects on the zero-energy touching point between the lowest conduction and the highest valence minibands of pristine bilayer graphene are exactly analyzed. Magnetic potential is shown also to generate the finite-energy touching points between higher minibands at the edges of Brillouin zone. The positions of these points and the related dispersions are determined in the case of symmetric potentials.

  16. Ultra high vacuum broad band high power microwave window

    DOE Patents [OSTI]

    Nguyen-Tuong, Viet (Seaford, VA); Dylla, III, Henry Frederick (Yorktown, VA)

    1997-01-01T23:59:59.000Z

    An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost.

  17. Special purpose modes in photonic band gap fibers

    DOE Patents [OSTI]

    Spencer, James; Noble, Robert; Campbell, Sara

    2013-04-02T23:59:59.000Z

    Photonic band gap fibers are described having one or more defects suitable for the acceleration of electrons or other charged particles. Methods and devices are described for exciting special purpose modes in the defects including laser coupling schemes as well as various fiber designs and components for facilitating excitation of desired modes. Results are also presented showing effects on modes due to modes in other defects within the fiber and due to the proximity of defects to the fiber edge. Techniques and devices are described for controlling electrons within the defect(s). Various applications for electrons or other energetic charged particles produced by such photonic band gap fibers are also described.

  18. Ultra high vacuum broad band high power microwave window

    DOE Patents [OSTI]

    Nguyen-Tuong, V.; Dylla, H.F. III

    1997-11-04T23:59:59.000Z

    An improved high vacuum microwave window has been developed that utilizes high density polyethylene coated on two sides with SiOx, SiNx, or a combination of the two. The resultant low dielectric and low loss tangent window creates a low outgassing, low permeation seal through which broad band, high power microwave energy may be passed. No matching device is necessary and the sealing technique is simple. The features of the window are broad band transmission, ultra-high vacuum compatibility with a simple sealing technique, low voltage standing wave ratio, high power transmission and low cost. 5 figs.

  19. Energy distribution of nonequilibrium electrons and optical phonons in GaAs under band-to-band pumping by intense short pulses of light

    SciTech Connect (OSTI)

    Altybaev, G. S.; Kumekov, S. E., E-mail: skumekov@mail.ru; Mahmudov, A. A. [Satpaev Kazakh National Technical University (Kazakhstan)

    2009-03-15T23:59:59.000Z

    Deviation from the Fermi distribution of nonequilibrium electrons and distribution of 'hot' optical phonons in GaAs under band-to-band pumping by picosecond pulses of light are calculated.

  20. Shear bands in a bulk metallic glass after large plastic deformation

    SciTech Connect (OSTI)

    Qu, D.D.; Wang, Y.B.; Liao, X.Z.; Shen, J. (Harbin); (Sydney)

    2012-10-23T23:59:59.000Z

    A transmission electron microscopy investigation is conducted to trace shear bands in a Zr{sub 53}Cu{sub 18.7}Ni{sub 12}Al{sub 16.3} bulk metallic glass after experiencing 4% plastic deformation. Shear band initiation, secondary shear band interactions, mature shear band broadening and the interactions of shear bands with shear-induced nanocrystals are captured. Results suggest that the plasticity of the bulk metallic glass is enhanced by complex shear bands and their interactions which accommodate large plastic strain and prevent catastrophic shear band propagation.

  1. Evidence for hybrid surface metallic band in (4?×?4) silicene on Ag(111)

    SciTech Connect (OSTI)

    Tsoutsou, D., E-mail: dtsoutsou@ims.demokritos.gr; Xenogiannopoulou, E.; Golias, E.; Tsipas, P.; Dimoulas, A. [National Center for Scientific Research “Demokritos,” 15310 Athens (Greece)] [National Center for Scientific Research “Demokritos,” 15310 Athens (Greece)

    2013-12-02T23:59:59.000Z

    The electronic band structure of monolayer (4?×?4) silicene on Ag(111) is imaged by angle resolved photoelectron spectroscopy. A dominant hybrid surface metallic band is observed to be located near the bulk Ag sp-band which is also faintly visible. The two-dimensional character of the hybrid band has been distinguished against the bulk character of the Ag(111) sp-band by means of photon energy dependence experiments. The surface band exhibits a steep linear dispersion around the K{sup Ż}{sub Ag} point and has a saddle point near the M{sup Ż}{sub Ag} point of Ag(111) resembling the ?-band dispersion in graphene.

  2. ON THE SIMULATION OF KINK BANDS IN FIBER REINFORCED COMPOSITES

    E-Print Network [OSTI]

    ON THE SIMULATION OF KINK BANDS IN FIBER REINFORCED COMPOSITES Kim D. Sørensen , Lars P. Mikkelsen reinforced composites are carried out using the commercial finite element program ABAQUS. A smeared in fiber reinforced composites has been the subject of a number of recent investigations. It has been found

  3. On complex perturbations of infinite band Schrodinger operators

    E-Print Network [OSTI]

    L. Golinskii; S. Kupin

    2015-02-20T23:59:59.000Z

    We study a complex perturbation of a self-adjoint infinite band Schrodinger operator (defined in the form sense), and obtain the Lieb--Thirring type inequalities for the rate of convergence of the discrete spectrum of the perturbed operator to the joint essential spectrum of both operators.

  4. Amplitude modulation free, wide band frequency modulated oscillator

    E-Print Network [OSTI]

    Nelson, Dick Frank

    1951-01-01T23:59:59.000Z

    /g sCIRIE/90 " --j/s~P&CI, 5 (5) The value of thc capacitance produced across the tank circuit is C = qgRICI. he c!er'vation gust nade is only good for the case where a si~mal is nodulated over a narrow band of two or t'. ~e per- cent deviation...

  5. Spatial dependence of banded chorus intensity near the magnetic equator

    E-Print Network [OSTI]

    of a provides a new boundary condition for consideration in current and future chorus generation models electrons with energies of 10 to 100 keV during and after geomagnetic storms can result in energy diffusion, using CRRES measurements, for both upper and lower band chorus as a function of L-shell and MLT

  6. CIRCULARLY POLARIZED ANTENNA ON SOI FOR THE 60 GHZ BAND

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of the primary criteria for evaluating the quality of the antenna; Improper feed, higher order band radiation integrated on SOI. In the first part, we describe the spiral antenna theory in order to have good radiation. The feeding structure is composed of a transition between radiofrequency coplanar waveguide feed, coplanar

  7. Bird Banding Fall 2014 The Arboretum at Penn State

    E-Print Network [OSTI]

    Boyer, Elizabeth W.

    -Central Rail Trail in Big Hollow, approximately 0.5 mile NW of the H.O. Smith Botanic Gardens. Banding is forest edge of brush growth, primarily 0 5 10 15 20 25 30 35 40 45 50 9-Sep 11-Sep 13-Sep 15-Sep 17-Sep

  8. Band-engineered Ge-on-Si lasers

    E-Print Network [OSTI]

    Liu, Jifeng

    We report optically-pumped Ge-on-Si lasers with direct gap emission near 1600 nm at room temperature. The Ge-on-Si material was band-engineered by tensile strain and n-type doping to compensate the energy difference between ...

  9. Degenerate band edges in optical fiber with multiple

    E-Print Network [OSTI]

    the forward energy fluxes S of the two media defines the coupling efficiency Ľ S2=S1. For PBG materialsDegenerate band edges in optical fiber with multiple grating: efficient coupling to slow light), School of Physics, University of Sydney, Sydney, New South Wales 2006, Australia 2 CUDOS, School

  10. Simultaneous confidence bands in curve prediction applied to load curves

    E-Print Network [OSTI]

    Boyer, Edmond

    Simultaneous confidence bands in curve prediction applied to load curves J.M. Aza¨is1, S. Bercu2, J, load curve. 1 Introduction In curve prediction, one is generally interested in deriving simultaneous this technique in the numerical context of load curve pre- diction: power producers like EDF, the electrical

  11. Anisotropy of strong pinning in multi-band superconductors

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Anisotropy of strong pinning in multi-band superconductors C.J. van der Beek, M. Konczykowski of the critical current density in iron-based superconductors is evaluated using a phenomenological approach collective pinning limit, and the strong pinning limit relevant for iron-based superconductors at low

  12. Structure and evolution of a convective band MCS

    E-Print Network [OSTI]

    Valdes-Manzanilla, Arturo

    1995-01-01T23:59:59.000Z

    circulation of the Mesoscale Convective Complex apparently aided in the formation of new lines of convection behind the primary convective line of the system. This process was repeated twice in the storm life cycle and led to multiple bands of convection...

  13. Safety Analysis for Packaging Steel Banded Wooden Shipping Containers

    SciTech Connect (OSTI)

    FERRELL, P.C.

    2000-12-05T23:59:59.000Z

    This safety analysis report for packaging describes the steel banded wooden shipping containers, which are certified as Type AF packagings. The authorized payload for these containers is unirradiated, slightly enriched, uranium ingots, billets, extrusions, and scrap materials. The amount of uranium in the containers will not exceed the LSA-II material requirements as defined in 49 CFR 173.403.

  14. absorption bands observed: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    absorption bands observed First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 AKARI observations of ice...

  15. Single-band and Dual-band Beam Switching Systems and Offset-fed Beam Scanning Reflectarray

    E-Print Network [OSTI]

    Lee, Jungkyu

    2012-07-16T23:59:59.000Z

    for multi-band applications. A modified Butler matrix is used to reduce a size and a sidelobe level. The bandwidth of the microstrip antenna is inherently small. A broadband circularly polarized microstrip antenna with dual-offset feedlines is introduced...

  16. Taxonomy of Clifford Cl_{3,0} subgroups: Choir and band groups

    E-Print Network [OSTI]

    Quirino M. Sugon Jr.; Daniel J. McNamara

    2008-09-02T23:59:59.000Z

    We list the subgroups of the basis set of Cl_{3,0} and classify them according to three criteria for construction of universal Clifford algebras: (1) each generator squares to +1 or -1, (2) the generators within the group anticommute, and (3) the order of the resulting group is 2^{n+1}, where n is the number of nontrivial generators. Obedient groups we call choirs; disobedient groups, bands. We classify choirs by modes and bands by rhythms, based on canonical equality. Each band generator has a transposition (number of other generators it commutes with). The band's transposition signature is the band's chord. The sum of transpositions divided by twice the number of generator pair combinations is the band's beat. The band's order deviation is the band's disorder. For n less than or equal 3, we show that the Cl_{3,0} basis set has 21 non-isomorphic subgroups consisting of 9 choirs and 12 bands.

  17. High peak power test of S-band waveguide switches

    SciTech Connect (OSTI)

    Nassiri, A.; Grelick, A.; Kustom, R.L.; White, M.

    1997-08-01T23:59:59.000Z

    The injector and source of particles for the Advanced Photon Source (APS) is a 2856-MHz S-band electron-positron linear accelerator (linac) which produces electrons with energies up to 650 MeV or positrons with energies up to 450 MeV. To improve the linac rf system availability, an additional modulator-klystron subsystem is being constructed to provide a switchable hot spare unit for each of the five existing S-band transmitters. The switching of the transmitters will require the use of SF6-pressurized waveguide switches at a peak operating power of 35 MW. A test stand was set up at the Stanford Linear Accelerator Center (SLAC) Klystron-Microwave laboratory to conduct tests characterizing the power handling capability of these waveguide switches. Test results are presented.

  18. RF modulation studies on the S band pulse compressor

    E-Print Network [OSTI]

    Shu, G; Pei, S; Xiao, O

    2015-01-01T23:59:59.000Z

    An S band SLED-type pulse compressor has been manufactured by IHEP to challenge the 100 MW maximum input power, which means the output peak power is about 500 MW at the phase reversal time. In order to deal with the RF breakdown problem, the dual side-wall coupling irises model was used. To further improve the reliability at very high power, amplitude modulation and phase modulation with flat-top output were taken into account. The RF modulation studies on an S-band SLED are presented in this paper. Furthermore, a method is developed by using the CST Microwave Studio transient solver to simulate the time response of the pulse compressor, which can be a verification of the modulate theory. In addition, the experimental setup was constructed and the flat-top output is obtained in the low power tests.

  19. RF modulation studies on the S band pulse compressor

    E-Print Network [OSTI]

    G. Shu; F. Zhao; S. Pei; O. Xiao

    2015-05-28T23:59:59.000Z

    An S band SLED-type pulse compressor has been manufactured by IHEP to challenge the 100 MW maximum input power, which means the output peak power is about 500 MW at the phase reversal time. In order to deal with the RF breakdown problem, the dual side-wall coupling irises model was used. To further improve the reliability at very high power, amplitude modulation and phase modulation with flat-top output were taken into account. The RF modulation studies on an S-band SLED are presented in this paper. Furthermore, a method is developed by using the CST Microwave Studio transient solver to simulate the time response of the pulse compressor, which can be a verification of the modulate theory. In addition, the experimental setup was constructed and the flat-top output is obtained in the low power tests.

  20. The Broad Band Spectral Energy Distributions of SDSS Blazars

    E-Print Network [OSTI]

    Li, Huaizhen; Jiang, Yunguo; Yi, Tingfeng

    2015-01-01T23:59:59.000Z

    We compiled the radio, optical, and X-ray data of blazars from the Sloan Digital Sky Survey (SDSS) database, and presented the distribution of luminosities and broad band spectral indices. The distribution of luminosities shows that the averaged luminosity of flat-spectral radio quasars (FSRQs) is larger than that of BL Lacs objects. On the other hand, the broad band spectral energy distribution reveals that FSRQs and low energy peaked BL Lac objects (LBLs) objects have similar spectral properties, but high energy peaked BL Lac objects (HBLs) have a distinct spectral property. This may be due to that different subclasses of blazars have different intrinsic environments and are at different cooling levels. Even so, a unified scheme also is revealed from the color-color diagram, which hints that there are similar physical processes operating in all objects under a range of intrinsic physical conditions or beaming parameter.

  1. Majorana Flat Bands in s-Wave Gapless Topological Superconductors

    E-Print Network [OSTI]

    Shusa Deng; Gerardo Ortiz; Amrit Poudel; Lorenza Viola

    2014-04-28T23:59:59.000Z

    We demonstrate how the non-trivial interplay between spin-orbit coupling and nodeless $s$-wave superconductivity can drive a fully gapped two-band topological insulator into a time-reversal invariant gapless topological superconductor supporting symmetry-protected Majorana flat bands. We characterize topological phase diagrams by a ${\\mathbb Z}_2 \\times{\\mathbb Z}_2$ partial Berry-phase invariant, and show that, despite the trivial crystal geometry, no unique bulk-boundary correspondence exists. We trace this behavior to the anisotropic quasiparticle bulk gap closing, linear vs. quadratic, and argue that this provides a unifying principle for gapless topological superconductivity. Experimental implications for tunneling conductance measurements are addressed, relevant for lead chalcogenide materials.

  2. Dissipationless Directed Transport in Rocked Single-Band Quantum Dynamics

    E-Print Network [OSTI]

    Jiangbin Gong; Dario Poletti; Peter Hanggi

    2007-02-28T23:59:59.000Z

    Using matter waves that are trapped in a deep optical lattice, dissipationless directed transport is demonstrated to occur if the single-band quantum dynamics is periodically tilted on one half of the lattice by a monochromatic field. Most importantly, the directed transport can exist for almost all system parameters, even after averaged over a broad range of single-band initial states. The directed transport is theoretically explained within ac-scattering theory. Total reflection phenomena associated with the matter waves travelling from a tilting-free region to a tilted region are emphasized. The results are of relevance to ultracold physics and solid-state physics, and may lead to powerful means of selective, coherent, and directed transport of cold particles in optical lattices.

  3. Chiral CP^2 skyrmions in three-band superconductors

    E-Print Network [OSTI]

    Julien Garaud; Johan Carlstrom; Egor Babaev; Martin Speight

    2013-01-14T23:59:59.000Z

    It is shown that under certain conditions, three-component superconductors (and in particular three-band systems) allow stable topological defects different from vortices. We demonstrate the existence of these excitations, characterized by a $CP^2$ topological invariant, in models for three-component superconductors with broken time reversal symmetry. We term these topological defects "chiral $GL^{(3)}$ skyrmions", where "chiral" refers to the fact that due to broken time reversal symmetry, these defects come in inequivalent left- and right-handed versions. In certain cases these objects are energetically cheaper than vortices and should be induced by an applied magnetic field. In other situations these skyrmions are metastable states, which can be produced by a quench. Observation of these defects can signal broken time reversal symmetry in three-band superconductors or in Josephson-coupled bilayers of $s_\\pm$ and s-wave superconductors.

  4. Band Tunneling through Double Barrier in Bilayer Graphene

    E-Print Network [OSTI]

    Hasan A. Alshehab; Hocine Bahlouli; Abderrahim El Mouhafid; Ahmed Jellal

    2014-01-20T23:59:59.000Z

    By taking into account the full four band energy spectrum, we calculate the transmission probability and conductance of electrons across symmetric and asymmetric double potential barrier with a confined interlayer potential difference in bilayer graphene. For energies less than the interlayer coupling \\gamma_{1}, E \\gamma_{1}, we obtain four possible ways for transmission resulting from the two propagating modes. We compute the associated transmission probabilities as well as their contribution to the conductance, study the effect of the double barrier geometry.

  5. TECHNICAL PAPER Micromachined W-band polymeric tunable iris filter

    E-Print Network [OSTI]

    Lin, Liwei

    -variable electrical length. Tunable filters with 3.8% tuning range at 20 GHz and a minimum insertion loss of 3.6 dTECHNICAL PAPER Micromachined W-band polymeric tunable iris filter Firas Sammoura · Liwei Lin.79 GHz and a minimum insertion loss of 2.37 dB with return loss better than 15 dB. As a tunable filter

  6. Implications of mercury interactions with band-gap semiconductor oxides

    SciTech Connect (OSTI)

    Granite, E.J.; King, W.P.; Stanko, D.C.; Pennline, H.W.

    2008-09-01T23:59:59.000Z

    Titanium dioxide is a well-known photooxidation catalyst. It will oxidize mercury in the presence of ultraviolet light from the sun and oxygen and/or moisture to form mercuric oxide. Several companies manufacture self-cleaning windows. These windows have a transparent coating of titanium dioxide. The titanium dioxide is capable of destroying organic contaminants in air in the presence of ultraviolet light from the sun, thereby keeping the windows clean. The commercially available self-cleaning windows were used to sequester mercury from oxygen–nitrogen mixtures. Samples of the self-cleaning glass were placed into specially designed photo-reactors in order to study the removal of elemental mercury from oxygen–nitrogen mixtures resembling air. The possibility of removing mercury from ambient air with a self-cleaning glass apparatus is examined. The intensity of 365-nm ultraviolet light was similar to the natural intensity from sunlight in the Pittsburgh region. Passive removal of mercury from the air may represent an option in lieu of, or in addition to, point source clean-up at combustion facilities. There are several common band-gap semiconductor oxide photocatalysts. Sunlight (both the ultraviolet and visible light components) and band-gap semiconductor particles may have a small impact on the global cycle of mercury in the environment. The potential environmental consequences of mercury interactions with band-gap semiconductor oxides are discussed. Heterogeneous photooxidation might impact the global transport of elemental mercury emanating from flue gases.

  7. Engineering Design of a Multipurpose X-band Accelerating Structure

    E-Print Network [OSTI]

    Gudkov, Dmitry; Samoshkin, Alexander; Zennaro, Riccardo; Dehler, Micha; Raguin, Jean-Yves

    2010-01-01T23:59:59.000Z

    Both FEL projects, SwissFEL and Fermi-Elettra each require an X-band RF accelerating structure for optimal bunch compression at the respective injectors. As the CLIC project is pursuing a program for producing and testing the X-band high-gradient RF structures, a collaboration between PSI, Elettra and CERN has been established to build a multipurpose X-band accelerating structure. This paper focuses on its engineering design, which is based on the disked cells jointed together by diffusion bonding. Vacuum brazing and laser beam welding is used for auxiliary components. The accelerating structure consists of two coupler subassemblies, 73 disks and includes a wakefield monitor and diagnostic waveguides. The engineering study includes the external cooling system, consisting of two parallel cooling circuits and an RF tuning system, which allows phase advance tuning of the cell by deforming the outer wall. The engineering solution for the installation and sealing of the wake field monitor feed-through devices that...

  8. Transport band gap opening at metal–organic interfaces

    SciTech Connect (OSTI)

    Haidu, Francisc, E-mail: francisc.haidu@physik.tu-chemnitz.de; Salvan, Georgeta; Zahn, Dietrich R. T. [Semiconductor Physics, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Smykalla, Lars; Hietschold, Michael [Solid Surfaces Analysis, Technische Universität Chemnitz, D-09107 Chemnitz (Germany); Knupfer, Martin [Electronic and Optical Properties Department, IFW Dresden, D-01171 Dresden (Germany)

    2014-07-01T23:59:59.000Z

    The interface formation between copper phthalocyanine (CuPc) and two representative metal substrates, i.e., Au and Co, was investigated by the combination of ultraviolet photoelectron spectroscopy and inverse photoelectron spectroscopy. The occupied and unoccupied molecular orbitals and thus the transport band gap of CuPc are highly influenced by film thickness, i.e., molecule substrate distance. Due to the image charge potential given by the metallic substrates the transport band gap of CuPc “opens” from (1.4?±?0.3) eV for 1?nm thickness to (2.2?±?0.3) eV, and saturates at this value above 10?nm CuPc thickness. The interface dipoles with values of 1.2?eV and 1.0?eV for Au and Co substrates, respectively, predominantly depend on the metal substrate work functions. X-ray photoelectron spectroscopy measurements using synchrotron radiation provide detailed information on the interaction between CuPc and the two metal substrates. While charge transfer from the Au or Co substrate to the Cu metal center is present only at sub-monolayer coverages, the authors observe a net charge transfer from the molecule to the Co substrate for films in the nm range. Consequently, the Fermi level is shifted as in the case of a p-type doping of the molecule. This is, however, a competing phenomenon to the energy band shifts due to the image charge potential.

  9. A Multiple-Channel Sub-Band Transient Detection System

    SciTech Connect (OSTI)

    David A. Smith

    1998-11-01T23:59:59.000Z

    We have developed a unique multiple-channel sub-band transient detection system to record transient electromagnetic signals in carrier-dominated radio environments; the system has been used to make unique observations of weak, transient HF signals. The detection system has made these observations possible through improved sensitivity compared to conventional broadband transient detection systems; the sensitivity improvement is estimated to be at least 20 dB. The increase in sensitivity has been achieved through subdivision of the band of interest (an 18 MHz tunable bandwidth) into eight sub-band independent detection channels, each with a 400 kHz bandwidth and its own criteria. The system generates a system trigger signal when a predetermined number of channels (typically five) trigger within a predetermined window of time (typically 100 ~s). Events are recorded with a broadband data acquisition system sampling at 50 or 100 Msample/s, so despite the fact that the detection system operates on portions of the signal confined to narrow bands, data acquisition is broadband. Between May and September of 1994, the system was used to detect and record over six thousand transient events in the frequency band from 3 to 30 MHz. Approximately 500 of the events have been characterized as paired bursts of radio noise with individual durations of 2 to 10 ps and separations between the bursts of 5 to 160 ps. The paired transients are typically 5 to 40 dB brighter than the background electromagnetic spectrum between carrier signals. We have termed these events SubIonospheric Pulse Pairs (SIPPS) and presently have no explanation as to their source. Our observations of SIPPS resemble observations of TransIonospheric Pulse Pairs (TIPPs) recorded by the Blackboard instrument on the ALEXIS satellite; the source of TIPP events is also unknown. Most of the recorded SIPP events do not exhibit frequency dispersion, implying propagation along a line-of-sight (groundwave) path; but seven of the pairs exhibit dispersion characteristic of skywave propagation via refraction from the ionosphere. The maximum line-of-sight observation range for radio propagation extends as far as 300 km for a source at an altitude of 5 km, and 520 km for a source at 15 km. Refraction from the ionosphere, however, may allow HF radiation to propagate around the globe. Information about the times and locations of sources, in conjunction with regional, weather maps and computer models of ionospheric propagation, suggest that some SIPP events originate in the vicinity of large-scale thunderstorm complexes.

  10. Pressure Behaviour of the UV and Green Emission Bands in ZnO...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Pressure Behaviour of the UV and Green Emission Bands in ZnO Micro-rods. Pressure Behaviour of the UV and Green Emission Bands in ZnO Micro-rods. Abstract: The pressure behavior of...

  11. Grand Traverse Band Renewable Energy Feasibility Study in Wind, Biomass and Solar

    SciTech Connect (OSTI)

    Suzanne McSawby, Project Director

    2008-12-31T23:59:59.000Z

    Renewable Energy Feasibility Study for wind, biomass, solar on the Grand Traverse Band tribal lands from 2005 - 2008

  12. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

    DOE Patents [OSTI]

    Wanlass, Mark W. (Golden, CO)

    1994-01-01T23:59:59.000Z

    A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.

  13. Diffuse Interstellar Band at 5850 as a Member of 5797 Spectroscopic Family

    E-Print Network [OSTI]

    Katarzyna Bryndal; Bogdan Wszo?ek

    2006-07-10T23:59:59.000Z

    The carriers of diffuse interstellar bands are still mysterious species. There exist many arguments that diffuse bands at 5797 and 5850 angstroms have the same carrier. Using high-resolution spectra of few dozens of reddened stars we have searched mutual correlation between intensities of considered bands. Results of our analysis indicate that 5797 and 5850 really tend to have the same carrier.

  14. The PortevinLe Chatelier (PLC) effect and shear band formation in an AA5754 alloy

    E-Print Network [OSTI]

    Niewczas, Marek

    The Portevin­Le Chatelier (PLC) effect and shear band formation in an AA5754 alloy Herdawandi Halim in order to observe Portevin­Le Chatelier (PLC) band behaviour during tensile deformation of AA5754 sheet and subsequently to measure the level of incre- mental plastic strain carried within the bands. In addition, PLC

  15. Retention of Butt-End Aluminum Leg Bands by Wild Turkeys

    E-Print Network [OSTI]

    Butler, Matthew J.

    Note Retention of Butt-End Aluminum Leg Bands by Wild Turkeys MATTHEW J. BUTLER,1,2 Department wild turkeys (Meleagris gallopavo intermedia) captured in Texas and Kansas, USA, 2000­2009. We examined 187 recaptured or harvested radiotagged wild turkeys to determine band retention and modeled band

  16. Band anticrossing effects in highly mismatched semiconductor alloys

    SciTech Connect (OSTI)

    Wu, Junqiao

    2002-09-09T23:59:59.000Z

    The first five chapters of this thesis focus on studies of band anticrossing (BAC) effects in highly electronegativity- mismatched semiconductor alloys. The concept of bandgap bowing has been used to describe the deviation of the alloy bandgap from a linear interpolation. Bowing parameters as large as 2.5 eV (for ZnSTe) and close to zero (for AlGaAs and ZnSSe) have been observed experimentally. Recent advances in thin film deposition techniques have allowed the growth of semiconductor alloys composed of significantly different constituents with ever- improving crystalline quality (e.g., GaAs{sub 1-x}N{sub x} and GaP{sub 1-x}N{sub x} with x {approx}< 0.05). These alloys exhibit many novel and interesting properties including, in particular, a giant bandgap bowing (bowing parameters > 14 eV). A band anticrossing model has been developed to explain these properties. The model shows that the predominant bowing mechanism in these systems is driven by the anticrossing interaction between the localized level associated with the minority component and the band states of the host. In this thesis I discuss my studies of the BAC effects in these highly mismatched semiconductors. It will be shown that the results of the physically intuitive BAC model can be derived from the Hamiltonian of the many-impurity Anderson model. The band restructuring caused by the BAC interaction is responsible for a series of experimental observations such as a large bandgap reduction, an enhancement of the electron effective mass, and a decrease in the pressure coefficient of the fundamental gap energy. Results of further experimental investigations of the optical properties of quantum wells based on these materials will be also presented. It will be shown that the BAC interaction occurs not only between localized states and conduction band states at the Brillouin zone center, but also exists over all of k-space. Finally, taking ZnSTe and ZnSeTe as examples, I show that BAC also occurs between localized states and the valence band states. Soft x-ray fluorescence experiments provide direct evidence of the BAC interaction in these systems. In the final chapter of the thesis, I describe and summarize my studies of optical properties of wurtzite InN and related alloys. Early studies performed on InN films grown by sputtering techniques suggested a direct bandgap of {approx}1.9 eV for this semiconductor. Very recently, high-quality InN films with much higher mobility have become available by using the molecular beam epitaxy growth method. Optical experiments carried out on these samples reveal a narrow bandgap for InN of 0.77 eV, much lower than the previously accepted value. Optical properties of InGaN and InAlN ternaries on the In rich side have also been characterized and are found to be consistent with the narrow bandgap of InN. The bandgap bowing parameters in these alloys were determined. In the context of these findings, the bandgap energies of InGaN and InAlN were found to cover a wide spectral range from the infrared for InN to the ultraviolet for GaN and deep ultraviolet for AlN. The significance of this work is rooted in many important applications of nitride semiconductors in optoelectronics and solar energy conversion devices.

  17. History and Evolution of Control Banding: A Review

    SciTech Connect (OSTI)

    Zalk, D; Nelson, D

    2006-07-19T23:59:59.000Z

    Control Banding (CB) strategies offer simplified solutions for controlling worker exposures to constituents often encountered in the workplace. The original CB model was developed within the pharmaceutical industry; however, the modern movement involves models developed for non-experts to input hazard and exposure potential information for bulk chemical processes, receiving control advice as a result. The CB approach utilizes these models for the dissemination of qualitative and semi-quantitative risk assessment tools being developed to complement the traditional industrial hygiene model of air sampling and analysis. It is being applied and tested in small and medium size enterprises (SMEs) within developed countries and industrially developing countries; however, large enterprises (LEs) have also incorporated these strategies within chemical safety programs. Existing research of the components of the most available CB model, the Control of Substances Hazardous to Health (COSHH) Essentials, has shown that exposure bands do not always provide adequate margins of safety, that there is a high rate of under-control errors, that it works better with dusts than with vapors, that there is an inherent inaccuracy in estimating variability, and that when taken together the outcomes of this model may lead to potentially inappropriate workplace confidence in chemical exposure reduction in some operations. Alternatively, large-scale comparisons of industry exposure data to this CB model's outcomes have indicated more promising results with a high correlation seen internationally. With the accuracy of the toxicological ratings and hazard band classification currently in question, their proper reevaluation will be of great benefit to the reliability of existing and future CB models. The need for a more complete analysis of CB model components and, most importantly, a more comprehensive prospective research process remains and will be important in understanding implications of the model's overall effectiveness. Since the CB approach is now being used worldwide with an even broader implementation in progress, further research toward understanding its strengths and weaknesses will assist in its further refinement and confidence in its ongoing utility.

  18. ZnO/Sn:In2O3 and ZnO/CdTe band offsets for extremely thin absorber...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ZnOSn:In2O3 and ZnOCdTe band offsets for extremely thin absorber photovoltaics . ZnOSn:In2O3 and ZnOCdTe band offsets for extremely thin absorber photovoltaics . Abstract: Band...

  19. Wide band cryogenic ultra-high vacuum microwave absorber

    DOE Patents [OSTI]

    Campisi, Isidoro E. (Newport News, VA)

    1992-01-01T23:59:59.000Z

    An absorber wave guide assembly for absorbing higher order modes of microwave energy under cryogenic ultra-high vacuum conditions, that absorbs wide-band multi-mode energy. The absorber is of a special triangular shape, made from flat tiles of silicon carbide and aluminum nitride. The leading sharp end of the absorber is located in a corner of the wave guide and tapers to a larger cross-sectional area whose center is located approximately in the center of the wave guide. The absorber is relatively short, being of less height than the maximum width of the wave guide.

  20. Wide band cryogenic ultra-high vacuum microwave absorber

    DOE Patents [OSTI]

    Campisi, I.E.

    1992-05-12T23:59:59.000Z

    An absorber waveguide assembly for absorbing higher order modes of microwave energy under cryogenic ultra-high vacuum conditions, that absorbs wide-band multi-mode energy. The absorber is of a special triangular shape, made from flat tiles of silicon carbide and aluminum nitride. The leading sharp end of the absorber is located in a corner of the waveguide and tapers to a larger cross-sectional area whose center is located approximately in the center of the wave guide. The absorber is relatively short, being of less height than the maximum width of the waveguide. 11 figs.

  1. VIMOS total transmission profiles for broad-band filters

    E-Print Network [OSTI]

    S. Mieske; M. Rejkuba; S. Bagnulo; C. Izzo; G. Marconi

    2007-04-13T23:59:59.000Z

    VIMOS is a wide-field imager and spectrograph mounted on UT3 at the VLT, whose FOV consists of four 7'x8' quadrants. Here we present the measurements of total transmission profiles -- i.e. the throughput of telescope + instrument -- for the broad band filters U, B, V, R, I, and z for each of its four quadrants. Those measurements can also be downloaded from the public VIMOS web-page. The transmission profiles are compared with previous estimates from the VIMOS consortium.

  2. Band Structure Asymmetry of Bilayer Graphene Revealed by Infrared Spectroscopy

    SciTech Connect (OSTI)

    Li, Z.Q.; Henriksen, E.A.; Jiang, Z.; Hao, Zhao; Martin, Michael C.; Kim, P.; Stormer, H.L.; Basov, Dimitri N.

    2008-12-10T23:59:59.000Z

    We report on infrared spectroscopy of bilayer graphene integrated in gated structures. We observe a significant asymmetry in the optical conductivity upon electrostatic doping of electrons and holes. We show that this finding arises from a marked asymmetry between the valence and conduction bands, which is mainly due to the inequivalence of the two sublattices within the graphene layer and the next-nearest-neighbor interlayer coupling. From the conductivity data, the energy difference of the two sublattices and the interlayer coupling energy are directly determined.

  3. W-band ARM Cloud Radar (WACR) Update and Status

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron SpinPrincetonUsing Maps1 -VisualizingVote For the Next HowSEEW-band ARM

  4. Triaxial strongly deformed bands in {sup 164}Hf and the effect of elevated yrast line

    SciTech Connect (OSTI)

    Ma Wenchao [Department of Physics, Mississippi State University, Mississippi State, MS 39762 (United States)

    2012-10-20T23:59:59.000Z

    Two exotic rotational bands have been identified in {sup 164}Hf and linked to known states. They are interpreted as being associated with the calculated triaxial strongly deformed (TSD) potential energy minimum. The bands are substantially stronger and are located at much lower spins than the previously discovered TSD bands in {sup 168}Hf. In addition to the proton and neutron shell gaps at large trixiality, it was proposed that the relative excitation energy of TSD bands above the yrast line plays an important role in the population of TSD bands.

  5. Partially filled intermediate band of Cr-doped GaN films

    SciTech Connect (OSTI)

    Sonoda, S. [Department of Electronics, Kyoto Institute of Technology, Kyoto 606-8585 (Japan)

    2012-05-14T23:59:59.000Z

    We investigated the band structure of sputtered Cr-doped GaN (GaCrN) films using optical absorption, photoelectron yield spectroscopy, and charge transport measurements. It was found that an additional energy band is formed in the intrinsic band gap of GaN upon Cr doping, and that charge carriers in the material move in the inserted band. Prototype solar cells showed enhanced short circuit current and open circuit voltage in the n-GaN/GaCrN/p-GaN structure compared to the GaCrN/p-GaN structure, which validates the proposed concept of an intermediate-band solar cell.

  6. Enhancement of band-to-band tunneling in mono-layer transition metal dichalcogenides two-dimensional materials by vacancy defects

    SciTech Connect (OSTI)

    Jiang, Xiang-Wei; Li, Shu-Shen [State Key Laboratory of Superlattices and Microstructures, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Gong, Jian [School of Physics Science and Technology, Inner Mongolia University, Hohhot 010021 (China); Xu, Nuo [Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Zhang, Jinfeng; Hao, Yue [Key Laboratory of Wide Band Gap Semiconductor Materials and Devices, School of Microelectronics, Xidian University, Xi'an 710071 (China); Wang, Lin-Wang, E-mail: lwwang@lbl.gov [Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2014-01-13T23:59:59.000Z

    The band-to-band tunneling of monolayer transition metal dichalcogenides nano-junction is investigated using atomistic ab initio quantum transport simulations. From the simulation, it is found that the transition metal vacancy defect in the two-dimensional MX{sub 2} (M = Mo,W; X = S,Se) band-to-band tunneling diode can dramatically boost the on-state current up to 10 times while maintaining the device sub-threshold swing. The performance enhancement mechanism is discussed in detail by examining partial density of states of the system. It is found that the transition metal vacancy induces band-gap states, which reduce the effective length of the tunneling transition region.

  7. Voltage-matched, monolithic, multi-band-gap devices

    SciTech Connect (OSTI)

    Wanlass, Mark W.; Mascarenhas, Angelo

    2006-08-22T23:59:59.000Z

    Monolithic, tandem, photonic cells include at least a first semiconductor layer and a second semiconductor layer, wherein each semiconductor layer includes an n-type region, a p-type region, and a given band-gap energy. Formed within each semiconductor layer is a sting of electrically connected photonic sub-cells. By carefully selecting the numbers of photonic sub-cells in the first and second layer photonic sub-cell string(s), and by carefully selecting the manner in which the sub-cells in a first and second layer photonic sub-cell string(s) are electrically connected, each of the first and second layer sub-cell strings may be made to achieve one or more substantially identical electrical characteristics.

  8. Voltage-Matched, Monolithic, Multi-Band-Gap Devices

    DOE Patents [OSTI]

    Wanlass, M. W.; Mascarenhas, A.

    2006-08-22T23:59:59.000Z

    Monolithic, tandem, photonic cells include at least a first semiconductor layer and a second semiconductor layer, wherein each semiconductor layer includes an n-type region, a p-type region, and a given band-gap energy. Formed within each semiconductor layer is a string of electrically connected photonic sub-cells. By carefully selecting the numbers of photonic sub-cells in the first and second layer photonic sub-cell string(s), and by carefully selecting the manner in which the sub-cells in a first and second layer photonic sub-cell string(s) are electrically connected, each of the first and second layer sub-cell strings may be made to achieve one or more substantially identical electrical characteristics.

  9. Engineering integrated pure narrow-band photon sources

    E-Print Network [OSTI]

    Enrico Pomarico; Bruno Sanguinetti; Clara I. Osorio; Harald Herrmann; Rob Thew

    2011-08-29T23:59:59.000Z

    Engineering and controlling well defined states of light for quantum information applications is of increasing importance as the complexity of quantum systems grows. For example, in quantum networks high multi-photon interference visibility requires properly devised single mode sources. In this paper we propose a spontaneous parametric down conversion source based on an integrated cavity-waveguide, where single narrow-band, possibly distinct, spectral modes for the idler and the signal fields can be generated. This mode selection takes advantage of the clustering effect, due to the intrinsic dispersion of the nonlinear material. In combination with a CW laser and fast detection, our approach provides a means to engineer a source that can efficiently generate pure photons, without filtering, that is compatible with long distance quantum communication. Furthermore, it is extremely flexible and could easily be adapted to a wide variety of wavelengths and applications.

  10. G-Band Vapor Radiometer Profiler (GVRP) Handbook

    SciTech Connect (OSTI)

    Caddeau, MP

    2010-06-23T23:59:59.000Z

    The G-Band Vapor Radiometer Profiler (GVRP) provides time-series measurements of brightness temperatures from 15 channels between 170 and 183.310 GHz. Atmospheric emission in this spectral region is primarily due to water vapor, with some influence from liquid water. Channels between 170.0 and 176.0 GHz are particularly sensitive to the presence of liquid water. The sensitivity to water vapor of the 183.31-GHz line is approximately 30 times higher than at the frequencies of the two-channel microwave radiometer (MWR) for a precipitable water vapor (PWV) amount of less than 2.5 mm. Measurements from the GVRP instrument are therefore especially useful during low-humidity conditions (PWV < 5 mm). In addition to integrated water vapor and liquid water, the GVRP can provide low-resolution vertical profiles of water vapor in very dry conditions.

  11. Initial assessment of an airborne Ku-band polarimetric SAR.

    SciTech Connect (OSTI)

    Raynal, Ann Marie; Doerry, Armin Walter

    2013-02-01T23:59:59.000Z

    Polarimetric synthetic aperture radar (SAR) has been used for a variety of dual-use research applications since the 1940's. By measuring the direction of the electric field vector from radar echoes, polarimetry may enhance an analyst's understanding of scattering effects for both earth monitoring and tactical surveillance missions. Polarimetry may provide insight into surface types, materials, or orientations for natural and man-made targets. Polarimetric measurements may also be used to enhance the contrast between scattering surfaces such as man-made objects and their surroundings. This report represents an initial assessment of the utility of, and applications for, polarimetric SAR at Ku-band for airborne or unmanned aerial systems.

  12. Band offsets at heterojunctions and the charge neutrality condition

    E-Print Network [OSTI]

    Taferner, Waltraud Teresa

    1990-01-01T23:59:59.000Z

    P InSb ZnSe Znte Gap indirect indirect indirect indirect direct indirect direct direct direct direct direct direct E4 (eV) O'K 0. 76 1. 13 2. 30 1. 88 1. 55 2. 35 0. 78 0. 43 1. 41 0. 23 2. 68 2. 56 If the atoms of a...&' ?r&rl c!?? &'nt h&: R . F. . X I 1 e n t C. 'k&r&ic &?f l'nn&rr&it&ee) l. H. B. r&ss (:& I e m h e r! R. R. L?cchese (lvlpmhe& ) etta. g R. AIT&&J?' &t t (Ifead of Department) May 1990 ABSTRACT Band OfFsets at Heterojunctions...

  13. 1634 IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS, VOL. 12, 2013 A Compact Dual-Band Rectenna Using Slot-Loaded

    E-Print Network [OSTI]

    Tentzeris, Manos

    , dual-band rectenna, dual-band rectifier, energy harvesting, wireless power transmission. I bands, RF energy harvesters capable of operating in multiple bands are of great importance. Nowadays by a microwave signal of available power of 9 dBm for a load resistor of 2.2 k . Index Terms--Dipole antenna

  14. Surface Plasmon Band Gap Sensor A new sensor for robust on-field biosensing (SEN 1)

    E-Print Network [OSTI]

    Arnaud Benahmed; Robert Lam; Chih-Ming Ho

    2006-01-01T23:59:59.000Z

    Networked Sensing Surface Plasmon Band Gap Sensor A newsensing concept Nanostructures for Surface Plasmon SensingSurface Plasmon are surface EM waves whose wavelength is

  15. Theoretical performance of solar cell based on mini-bands quantum dots

    SciTech Connect (OSTI)

    Aly, Abou El-Maaty M., E-mail: drabouelmaaty@hotmail.com, E-mail: ashraf.nasr@gmail.com [Power Electronics and Energy Conversion Department, ERI, NRCB (Egypt); College of Computer, Qassim University, P.O.B. 6688, Buryadah 51453 (Saudi Arabia); Nasr, A., E-mail: drabouelmaaty@hotmail.com, E-mail: ashraf.nasr@gmail.com [Radiation Engineering Department, NCRRT, Atomic Energy Authority (Egypt); College of Computer, Qassim University, P.O.B. 6688, Buryadah 51453 (Saudi Arabia)

    2014-03-21T23:59:59.000Z

    The tremendous amount of research in solar energy is directed toward intermediate band solar cell for its advantages compared with the conventional solar cell. The latter has lower efficiency because the photons have lower energy than the bandgap energy and cannot excite mobile carriers from the valence band to the conduction band. On the other hand, if mini intermediate band is introduced between the valence and conduction bands, then the smaller energy photons can be used to promote charge carriers transfer to the conduction band and thereby the total current increases while maintaining a large open circuit voltage. In this article, the influence of the new band on the power conversion efficiency for structure of quantum dots intermediate band solar cell is theoretically investigated and studied. The time-independent Schrödinger equation is used to determine the optimum width and location of the intermediate band. Accordingly, achievement of a maximum efficiency by changing the width of quantum dots and barrier distances is studied. Theoretical determination of the power conversion efficiency under the two different ranges of QD width is presented. From the obtained results, the maximum power conversion efficiency is about 70.42%. It is carried out for simple cubic quantum dot crystal under fully concentrated light. It is strongly dependent on the width of quantum dots and barrier distances.

  16. Fractional Band Filling in an Atomic Chain Structure J. N. Crain,1

    E-Print Network [OSTI]

    Himpsel, Franz J.

    then splits into a spinon and holon band. The energy scale of this many-electron effect can be boosted [13

  17. Band structure engineering through orbital interaction for enhanced thermoelectric power factor

    E-Print Network [OSTI]

    Zhu, Hong

    Band structure engineering for specific electronic or optical properties is essential for the further development of many important technologies including thermoelectrics, optoelectronics, and microelectronics. In this ...

  18. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

    DOE Patents [OSTI]

    Wanlass, M.W.

    1994-12-27T23:59:59.000Z

    A single-junction solar cell is described having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of ''pinning'' the optimum band gap for a wide range of operating conditions at a value of 1.14[+-]0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap. 7 figures.

  19. The mechanism and realization of a band-agile coaxial relativistic backward-wave oscillator

    SciTech Connect (OSTI)

    Ge, Xingjun; Zhang, Jun; Zhong, Huihuang; Qian, Baoliang; Wang, Haitao [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2014-11-03T23:59:59.000Z

    The mechanism and realization of a band-agile coaxial relativistic backward-wave oscillator (RBWO) are presented. The operation frequency tuning can be easily achieved by merely altering the inner-conductor length. The key effects of the inner-conductor length contributing to the mechanical frequency tunability are investigated theoretically and experimentally. There is a specific inner-conductor length where the operation frequency can jump from one mode to another mode, which belongs to a different operation band. In addition, the operation frequency is tunable within each operation band. During simulation, the L-band microwave with a frequency of 1.61 GHz is radiated when the inner-conductor length is 39?cm. Meanwhile, the S-band microwave with a frequency of 2.32 GHz is radiated when the inner-conductor length is 5?cm. The frequency adjustment bandwidths of L-band and S-band are about 8.5% and 2%, respectively. Moreover, the online mechanical tunability process is described in detail. In the initial experiment, the generated microwave frequencies remain approximately 1.59 GHz and 2.35?GHz when the inner-conductor lengths are 39?cm and 5?cm. In brief, this technical route of the band-agile coaxial RBWO is feasible and provides a guide to design other types of band-agile high power microwaves sources.

  20. PHYSICAL REVIEW B 90, 115209 (2014) Computational search for direct band gap silicon crystals

    E-Print Network [OSTI]

    Lee, Jooyoung

    2014-01-01T23:59:59.000Z

    of microns thick, while solar cells made from direct band gap materials (such as CdTe, CIGS, or CZTS) can

  1. Temperature dependent band offsets in PbSe/PbEuSe quantum well heterostructures

    SciTech Connect (OSTI)

    Simma, M.; Bauer, G.; Springholz, G. [Institut fuer Halbleiter und Festkoerperphysik, Johannes Kepler Universitaet, A-4040 Linz (Austria)

    2012-10-22T23:59:59.000Z

    The band offsets of PbSe/Pb{sub 1-x}Eu{sub x}Se multi-quantum wells grown by molecular beam epitaxy are determined as a function of temperature and europium content using temperature-modulated differential transmission spectroscopy. The confined quantum well states in the valence and conduction bands are analyzed using a k{center_dot}p model with envelope function approximation. From the fit of the experimental data, the normalized conduction band offset is determined as 0.45{+-}0.15 of the band gap difference, independently of Eu content up to 14% and temperature from 20 to 300 K.

  2. Band gap and band parameters of InN and GaN from quasiparticle energy calculations based on exact-exchange density-functional theory

    E-Print Network [OSTI]

    Band gap and band parameters of InN and GaN from quasiparticle energy calculations based on exact; published online 20 October 2006 The authors have studied the electronic structure of InN and GaN employing. © 2006 American Institute of Physics. DOI: 10.1063/1.2364469 The group III-nitrides AlN, GaN, and In

  3. CO Cameron band and CO2+ UV doublet emissions in the dayglow of Venus: Role of CO in the Cameron band production

    E-Print Network [OSTI]

    Bhardwaj, Anil

    2013-01-01T23:59:59.000Z

    Present study deals with the model calculations of CO Cameron band and CO2+ ultraviolet doublet emissions in the dayglow of Venus. The overhead and limb intensities of CO Cameron band and CO2+ UV doublet emissions are calculated for low, moderate, and high solar activity conditions. Using updated cross sections, the impact of dierent e-CO cross section for Cameron band production is estimated. The electron impact on CO is the major source mechanism of Cameron band, followed by electron and photon impact dissociation of CO2. The overhead intensities of CO Cameron band and CO2+ UV doublet emissions are about a factor of 2 higher in solar maximum than those in solar minimum condition. The effect of solar EUV flux models on the emission intensity is ~30-40% in solar minimum condition and ~2-10% in solar maximum condition. At the altitude of emission peak (135 km), the model predicted limb intensity of CO Cameron band and CO2+ UV doublet emissions in moderate (F10.7 = 130) solar activity condition is about 2400 an...

  4. Dual-band infrared capabilities for imaging buried object sites

    SciTech Connect (OSTI)

    Del Grande, N.K.; Durbin, P.F.; Gorvad, M.R.; Perkins, D.E.; Clark, G.A.; Hernandez, J.E.; Sherwood, R.J.

    1993-04-02T23:59:59.000Z

    We discuss dual-band infrared (DBIR) capabilities for imaging buried object sizes. We identify physical features affecting thermal contrast needed to distinguish buried object sites from undisturbed sites or surface clutter. Apart from atmospheric transmission and system performance, these features include: object size, shape, and burial depth; ambient soil, disturbed soil and object site thermal diffusivity differences; surface temperature, emissivity, plant-cover, slope, albedo and roughness variations; weather conditions and measurement times. We use good instrumentation to measure the time-varying temperature differences between buried object sites and undisturbed soil sites. We compare near surface soil temperature differences with radiometric infrared (IR) surface temperature differences recorded at 4.7 {plus_minus} 0.4 {mu}m and at 10.6 {plus_minus} 1.0 {mu}m. By producing selective DBIR image ratio maps, we distinguish temperature-difference patterns from surface emissivity effects. We discuss temperature differences between buried object sites, filled hole site (without buried objects), cleared (undisturbed) soil sites, and grass-covered sites (with and without different types of surface clutter). We compare temperature, emissivity-ratio, visible and near-IR reflectance signatures of surface objects, leafy plants and sod. We discuss the physical aspects of environmental, surface and buried target features affecting interpretation of buried targets, surface objects and natural backgrounds.

  5. Precision Magnet Measurements for X-Band Accelerator Quadrupole Triplets

    SciTech Connect (OSTI)

    Marsh, R A; Anderson, S G; Armstrong, J P

    2012-05-16T23:59:59.000Z

    An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray (MEGa-Ray) technology at LLNL. Beamline magnets will include an emittance compensation solenoid, windowpane steering dipoles, and quadrupole magnets. Demanding tolerances have been placed on the alignment of these magnets, which directly affects the electron bunch beam quality. A magnet mapping system has been established at LLNL in order to ensure the delivered magnets match their field specification, and the mountings are aligned and capable of reaching the specified alignment tolerances. The magnet measurement system will be described which uses a 3-axis Lakeshore gauss probe mounted on a 3-axis translation stage. Alignment accuracy and precision will be discussed, as well as centering measurements and analysis. The dependence on data analysis over direct multi-pole measurement allows a significant improvement in useful alignment information. Detailed analysis of measurements on the beamline quadrupoles will be discussed, including multi-pole content both from alignment of the magnets, and the intrinsic level of multi-pole magnetic field.

  6. A representative sample of Be stars III: H band spectroscopy

    E-Print Network [OSTI]

    I. A. Steele; J. S. Clark

    2001-03-16T23:59:59.000Z

    We present H band (1.53 - 1.69 micron) spectra of 57 isolated Be stars of spectral types O9-B9 and luminosity classes III,IV & V. The HI Brackett (n-4) series is seen in emission from Br 11-18, and FeII emission is also apparent for a subset of those stars with HI emission. No emission from species with a higher excitation temperature, such as He II or CIII is seen, and no forbidden line emission is present. A subset of 12 stars show no evidence for emission from any species; these stars appear indistinguishable from normal B stars of a comparable spectral type. In general the line ratios constructed from the transitions in the range Br 11-18 do not fit case B recombination theory particularly well. Strong correlations between the line ratios with Br-gamma and spectral type are found. These results most likely represent systematic variations in the temperature and ionization of the circumstellar disc with spectral type. Weak correlations between the line widths and projected rotational velocity of the stars are observed; however no systematic trend for increasing line width through the Brackett series is observed.

  7. High-spin structure and Band Termination in $^{103}$Cd

    E-Print Network [OSTI]

    A. Chakraborty; Krishichayan; S. Mukhopadhyay; S. Ray; S. N. Chintalapudi; S. S. Ghugre; N. S. Pattabiraman; A. K. Sinha; S. Sarkar; U. Garg; S. Zhu; M. Saha Sarkar

    2007-09-11T23:59:59.000Z

    Excited states of the neutron deficient $^{103}$Cd nucleus have been investigated via the $^{72}$Ge($^{35}$Cl, p3n) reaction at beam energy of 135 MeV by use of in-beam spectroscopic methods. Gamma rays depopulating the excited states were detected using the Gammasphere spectrometer with high-fold $\\gamma$-ray coincidences. A quadrupole $\\gamma$-ray coincidence analysis ($\\gamma^{4}$) has been used to extend the known level scheme. The positive parity levels have been established up to $J = 35/2\\hbar$ and $E_{x} = 7.071$ MeV. In addition to the observation of highly-fragmented level scheme belonging to the positive-parity sequences at E$_{x}\\sim$ 5 MeV, the termination of a negative-parity sequence connected by $E2$ transitions has been established at $J = 47/2 \\hbar$ and $E_{x} = 11.877$ MeV. The experimental results corresponding to both the positive- and negative-parity sequences have been theoretically interpreted in the framework of the core particle coupling model. Evidence is presented for a shape change from collective prolate to non-collective oblate above the $J^{\\pi} = 39/2^{-}$ (8011 keV) level and for a smooth termination of the negative-parity band.

  8. Frozen light in photonic crystals with degenerate band edge

    E-Print Network [OSTI]

    A. Figotin; I. Vitebskiy

    2006-10-09T23:59:59.000Z

    Consider a plane monochromatic wave incident on a semi-infinite periodic structure. What happens if the normal component of the transmitted wave group velocity vanishes? At first sight, zero normal component of the transmitted wave group velocity simply implies total reflection of the incident wave. But we demonstrate that total reflection is not the only possible outcome. Instead, the transmitted wave can appear in the form of a frozen mode with very large diverging amplitude and either zero, or purely tangential energy flux. The field amplitude in the transmitted wave can exceed that of the incident wave by several orders of magnitude. There are two qualitatively different kinds of frozen mode regime. The first one is associated with a stationary inflection point of electromagnetic dispersion relation. This phenomenon has been analyzed in our previous publications. Now, our focus is on the frozen mode regime related to a degenerate photonic band edge. An advantage of this new phenomenon is that it can occur in much simpler periodic structures. This spectacular effect is extremely sensitive to the frequency and direction of propagation of the incident plane wave. These features can be very attractive in a variety practical applications, such as higher harmonic generation and wave mixing, light amplification and lasing, highly efficient superprizms, etc.

  9. Enhancement of computer program SPECTRAN to provide optional synthesis of 1/12 octave-band and critical-band spectra from 1/3 octave-band spectra

    SciTech Connect (OSTI)

    Chang, Young-Soo [Argonne National Lab., IL (United States); Liebich, R.E. [Raytheon Environmental Services Company, Cambridge, MA (United States)

    1997-07-01T23:59:59.000Z

    This paper describes greatly enhanced version of the computer program SPECTRAN, which was initially presented in Paper No. 96-RA104.01, at the A&WMA 89th Annual Meeting in June 1996. The program has had three basic upgrades since that time. The first is provision of an option to use either batch-mode input from previously prepared data files or a {open_quotes}user-friendly{close_quotes} interactive input routine. The latter is primarily for first-time users and those having only one, or very few, spectra to process. The second improvement is the synthesis of 1/12 octave-band spectra from 1/3 octave-band spectra, with {open_quotes}tone correction,{close_quotes} in a manner similar to that used in the original version of the program. The third fundamental improvement is addition of a unique new capability to synthesize classic {open_quotes}critical-band{close_quotes} spectra from 1/3 octave-band input spectra. Critical-band spectra are also termed {open_quotes}equivalent-rectangular-bandwidth (ERB){close_quotes} and {open_quotes}equal-contribution-to-speech (ECS){close_quotes} spectra.

  10. Intermediate-band solar cells based on quantum dot supracrystals Q. Shao and A. A. Balandina

    E-Print Network [OSTI]

    parameter in the photovoltaic PV solar cell technology. It is defined as = FFVocJsc Pin , 1 where FFIntermediate-band solar cells based on quantum dot supracrystals Q. Shao and A. A. Balandina Nano to implement the intermediate-band solar cell with the efficiency exceeding the Shockley-Queisser limit

  11. Dopant-induced band filling and bandgap renormalization in CdO:In films

    E-Print Network [OSTI]

    thereof or The Regents of the University of California. 1 #12;Abstract The effect of carrier concentration-Moss effect for a nonparabolic conduction band and bandgap renormalization effects. The band filling attracted much interest due to their tremendous importance in applications such as displays, photovoltaic

  12. Fractal Shear Bands at Elastic-Plastic Transitions in Random Mohr-Coulomb Materials

    E-Print Network [OSTI]

    Ostoja-Starzewski, Martin

    Fractal Shear Bands at Elastic-Plastic Transitions in Random Mohr-Coulomb Materials J. Li, A.M.ASCE1 ; and M. Ostoja-Starzewski, M.ASCE2 Abstract: This paper studies fractal patterns forming of plastic grains (i.e., a shear-band system) is always a monotonically growing fractal under increasing

  13. Crossing of large multiquasiparticle magnetic-rotation bands in $^{198}$Bi

    E-Print Network [OSTI]

    H. Pai; G. Mukherjee; S. Bhattacharyya; C. Bhattacharya; S. Bhattacharya; T. Bhattacharjee; S. K. Basu; S. Kundu; T. K. Ghosh; K. Banerjee; T. K. Rana; J. K. Meena; R. K. Bhowmik; R. P. Singh; S. Muralithar; S. Chanda; R. Garg; B. Maheshwari; D. Choudhury; A. K. Jain

    2014-12-22T23:59:59.000Z

    High-spin states in the doubly-odd $^{198}$Bi nucleus have been studied by using the $^{185,187}$Re($^{16}$O, xn) reactions at the beam energy of 112.5 MeV. $\\gamma-\\gamma$ coincidence were measured by using the INGA array with 15 Compton suppressed clover HPGe detectors. The observed levels have been assigned definite spin-parity. The high spin structure is grouped into three bands (B1, B2 and B3), of which two (B1 and B2) exhibit the properties of magnetic rotation (MR). Tilted axis cranking calculations were carried out to explain the MR bands having large multi-quasiparticle configurations. The calculated results explain the bands B1 and B2 very nicely, confirming the shears mechanism and suggest a crossing of two MR bands in both the cases. The crossing is from 6-qp to 8-qp in band B1 and from 4-qp to 6-qp in band B2, a very rare finding. A semiclassical model has also been used to obtain the particle-hole interaction strengths for the bands B1 and B2, below the band crossing.

  14. A Multi-band VCO PLL with the Continuously Maintained Optimum VCO

    E-Print Network [OSTI]

    Choi, Woo-Young

    , voltage, and temperature (PVT) variation and, consequently, multi-band VCOs are commonly used. A multi with the selected VCO sub-band is done in the low- gain mode. Fig. 1 shows the block diagram of one type of a dual Structure: Fig. 3 shows the block diagram of our PLL that can continuously maintain optimum Vcont. Our PLL

  15. Semiclassical molecular dynamics simulations of ultrafast photodissociation dynamics associated with the Chappuis band of ozone

    E-Print Network [OSTI]

    Miller, William H.

    with the Chappuis band of ozone Victor S. Batista and William H. Millera) Department of Chemistry, University A ) of ozone following photoexcitation of the molecule in the gas phase with visible light. Our algorithm and recurrence events, as well as an interpretation of experimental studies of the Chappuis band of ozone

  16. Characterization of Al and Mg alloys from their x-ray emission bands

    E-Print Network [OSTI]

    in that regard. The main alloying element of Mg alloys is aluminum. Also, magnesium is an important alloying element of aluminum alloys. Therefore, studying the band structure of Mg­Al alloys is as important1 Characterization of Al and Mg alloys from their x-ray emission bands Philippe Jonnard, Karine Le

  17. PHYSICAL REVIEW B 85, 195405 (2012) Graphene on Ru(0001): Evidence for two graphene band structures

    E-Print Network [OSTI]

    Goodman, Wayne

    2012-01-01T23:59:59.000Z

    PHYSICAL REVIEW B 85, 195405 (2012) Graphene on Ru(0001): Evidence for two graphene band structures) High-resolution photoemission illustrates that the band structure of graphene on Ru(0001) exhibits a well- defined splitting. This splitting is largest with the graphene directly on the Ru(0001) substrate

  18. Beta band oscillations during basic sentence comprehension in patients with schizophrenia

    E-Print Network [OSTI]

    Kuperberg, Gina

    Beta band oscillations during basic sentence comprehension in patients with schizophrenia Kirsten & Hickok (2009) Beta band oscillations during language processing ·In language comprehension we bind words wordlists elicits larger responses in the lower beta frequency range1 ·This has been attributed

  19. Comparison of Model Prediction With Measurements of Galactic Background Noise at L-Band

    E-Print Network [OSTI]

    Boyer, Edmond

    with measurements made with several modern L-band remote sensing radiometers. The comparison validates the model and ocean salinity that are needed for understanding the hydrological cycle, ocean circu- lation, and energy surface salinity, which requires high radiometric accuracy (at L-band the sensitivity to salinity

  20. Active Slip Band Separation and the Energetics of Slip in Single Crystals

    E-Print Network [OSTI]

    Active Slip Band Separation and the Energetics of Slip in Single Crystals Abstract This research supports recent efforts to provide an energetic ap- proach the formulation of new measures of the active slip-band separation and of the number of lattice cells

  1. Low-voltage broad-band electroabsorption from thin Ge/SiGe

    E-Print Network [OSTI]

    Miller, David A. B.

    Low-voltage broad-band electroabsorption from thin Ge/SiGe quantum wells epitaxially grown than 5 dB over the entire telecommunication S- and C-bands with only 1V drive using a new Ge/SiGe QW epitaxy design approach; further, this is demonstrated with the thinnest Ge/SiGe epitaxy to date, using

  2. Rubber Band Recoil By R. Vermorel, N. Vandenberghe and E. Villermaux

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Rubber Band Recoil By R. Vermorel, N. Vandenberghe and E. Villermaux Universit´e de Provence, IRPHE, 49, rue Fr´ed´eric Joliot-Curie 13384 Marseille Cedex 13, France When an initially stretched rubber to obtain a relation be- tween the buckled wavelength, the initial stretching and the rubber band thickness

  3. Thermoelectric power measurements of wide band gap semiconducting Chul-Ho Lee,1

    E-Print Network [OSTI]

    Kim, Philip

    Thermoelectric power measurements of wide band gap semiconducting nanowires Chul-Ho Lee,1 Gyu online 13 January 2009 We investigated the temperature-dependent thermoelectric power TEP of individual concentration in wide band gap semiconducting nano- wires employing temperature-dependent thermoelectric power

  4. Slow electromagnetic pulse propagation through a narrow transmission band in a coaxial photonic crystal

    E-Print Network [OSTI]

    Robertson, William

    Slow electromagnetic pulse propagation through a narrow transmission band in a coaxial photonic the slow group-velocity propagation of electromagnetic pulses through a narrow transmission band describe a simple experimental configuration that leads to slow-group-velocity electromagnetic pulse

  5. Contribution to the establishment of the R-banded karyotype in dogs

    E-Print Network [OSTI]

    Boyer, Edmond

    Contribution to the establishment of the R-banded karyotype in dogs M Moreno-Millán A Rodero FJ a system of arranging R-bands. We describe a new contribution to the canine karyotype obtained after cultures of integral blood according to the method of de Grouchy et al (1964) slightly mod- ified

  6. Light trapping design for low band-gap polymer solar cells

    E-Print Network [OSTI]

    John, Sajeev

    Light trapping design for low band-gap polymer solar cells Stephen Foster1,* and Sajeev John1,2 1 demonstrate numerically a 2-D nanostructured design for light trapping in a low band-gap polymer solar cell observe an enhancement in solar absorption of almost 40% relative to a planar cell. Improvements

  7. Plasma process-induced band-gap modifications of a strained SiGe heterostructure

    E-Print Network [OSTI]

    Misra, Durgamadhab "Durga"

    Plasma process-induced band-gap modifications of a strained SiGe heterostructure P. K. Swain,a) S the strain of coherently strained SiGe. This work investigates the change in valence-band discontinuity in plasma-exposed SiGe films due to strain relaxation by a capacitance­voltage (C­V) profiling technique

  8. Electronic structure of QD arrays: Application to intermediate-band solar cells

    E-Print Network [OSTI]

    )Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK Abstract-Intermediate band solar cells (IBSC) have the thermodynamic efficiency limits of solar energy conversion. While tandem solar cells can the- oretically exceedNUSOD 2007 Electronic structure of QD arrays: Application to intermediate-band solar cells S

  9. Band gap changes of GaN shocked to 13 GPa M. D. McCluskeya)

    E-Print Network [OSTI]

    McCluskey, Matthew

    Band gap changes of GaN shocked to 13 GPa M. D. McCluskeya) and Y. M. Gupta Institute for Shock, California 94304 Received 24 October 2001; accepted for publication 19 December 2001 The band gap of GaN in shock-wave experiments. Shock waves were generated by impacting the GaN samples with c-cut sapphire

  10. Fine structure of the red luminescence band in undoped GaN

    SciTech Connect (OSTI)

    Reshchikov, M. A., E-mail: mreshchi@vcu.edu [Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Usikov, A. [Nitride Crystals, Inc., 181E Industry Ct., Ste. B, Deer Park, New York 11729 (United States); Saint-Petersburg National Research University of Information Technologies, Mechanics and Optics, 49 Kronverkskiy Ave., 197101 Saint Petersburg (Russian Federation); Helava, H.; Makarov, Yu. [Nitride Crystals, Inc., 181E Industry Ct., Ste. B, Deer Park, New York 11729 (United States)

    2014-01-20T23:59:59.000Z

    Many point defects in GaN responsible for broad photoluminescence (PL) bands remain unidentified. Their presence in thick GaN layers grown by hydride vapor phase epitaxy (HVPE) detrimentally affects the material quality and may hinder the use of GaN in high-power electronic devices. One of the main PL bands in HVPE-grown GaN is the red luminescence (RL) band with a maximum at 1.8?eV. We observed the fine structure of this band with a zero-phonon line (ZPL) at 2.36?eV, which may help to identify the related defect. The shift of the ZPL with excitation intensity and the temperature-related transformation of the RL band fine structure indicate that the RL band is caused by transitions from a shallow donor (at low temperature) or from the conduction band (above 50?K) to an unknown deep acceptor having an energy level 1.130?eV above the valence band.

  11. PLASTICITY OF DAMAGED SOLIDS AND SHEAR BAND LOCALIZATION MARIA K.DUSZEK and PIOTR PERZYNA

    E-Print Network [OSTI]

    Boyer, Edmond

    694 PLASTICITY OF DAMAGED SOLIDS AND SHEAR BAND LOCALIZATION MARIA K.DUSZEK and PIOTR PERZYNA of shear band localization conditions for finite elastic-plastic rate independent deformations of damaged for elastic-plastic solids when iso- tropic and kinematic hardening effects and micro-damage process are taken

  12. A Near-Infrared Stellar Spectral Library: II. K-Band Spectra

    E-Print Network [OSTI]

    Arvind C. Ranade; Harinder P. Singh; Ranjan Gupta; N. M. Ashok

    2007-05-31T23:59:59.000Z

    This paper is the second in the series of papers on near-infrared (NIR) stellar spectral library produced by reducing the observations carried out with 1.2 meter Gurushikhar Infrared Telescope (GIRT), at Mt. Abu, India using a NICMOS3 HgCdTe 256 X 256 NIR array based spectrometer. In paper I (Ranade et al. 2004), H-band spectra of 135 stars at a resolution of ~16 Ang were presented. The K-band library being released now consists of 114 stars covering spectral types O7--M7 and luminosity classes I--V. The spectra have a moderate resolution of ~22 Ang in the K band and have been continuum shape corrected to their respective effective temperatures. We hope to release the remaining J-band spectra soon. The complete H and K-Band library is available online at: http://vo.iucaa.ernet.in/~voi/NIR_Header.html

  13. One-dimensional electromagnetic band gap structures formed by discharge plasmas in a waveguide

    SciTech Connect (OSTI)

    Arkhipenko, V. I.; Simonchik, L. V., E-mail: l.simonchik@dragon.bas-net.by; Usachonak, M. S. [B.I. Stepanov Institute of Physics of the NAS of Belarus, Ave. Nezavisimostsi 68, 220072 Minsk (Belarus); Callegari, Th.; Sokoloff, J. [Université de Toulouse, UPS, INPT, LAPLACE, Laboratoire Plasma et Conversion d'Energie, 118 route de Narbonne, F-31062 Toulouse cedex 9 (France)

    2014-09-28T23:59:59.000Z

    We demonstrate the ability to develop one-dimensional electromagnetic band gap structure in X-band waveguide solely by using the positive columns of glow discharges in neon at the middle pressure. Plasma inhomogeneities are distributed uniformly along a typical X-band waveguide with cross section of 23?×?10?mm{sup 2}. It is shown that electron densities larger than 10{sup 14?}cm{sup ?3} are needed in order to create an effective one-dimensional electromagnetic band gap structure. Some applications for using the one-dimensional electromagnetic band gap structure in waveguide as a control of microwave (broadband filter and device for variation of pulse duration) are demonstrated.

  14. Dilute Group III-V nitride intermediate band solar cells with contact blocking layers

    DOE Patents [OSTI]

    Walukiewicz, Wladyslaw (Kensington, CA); Yu, Kin Man (Lafayette, CA)

    2012-07-31T23:59:59.000Z

    An intermediate band solar cell (IBSC) is provided including a p-n junction based on dilute III-V nitride materials and a pair of contact blocking layers positioned on opposite surfaces of the p-n junction for electrically isolating the intermediate band of the p-n junction by blocking the charge transport in the intermediate band without affecting the electron and hole collection efficiency of the p-n junction, thereby increasing open circuit voltage (V.sub.OC) of the IBSC and increasing the photocurrent by utilizing the intermediate band to absorb photons with energy below the band gap of the absorber layers of the IBSC. Hence, the overall power conversion efficiency of a IBSC will be much higher than an conventional single junction solar cell. The p-n junction absorber layers of the IBSC may further have compositionally graded nitrogen concentrations to provide an electric field for more efficient charge collection.

  15. Defect-Band Emission Photoluminescence Imaging on Multi-Crystalline Si Solar Cells: Preprint

    SciTech Connect (OSTI)

    Yan, F.; Johnston, S.; Zaunbrecher, K.; Al-Jassim, M.; Sidelkheir, O.; Blosse, A.

    2011-07-01T23:59:59.000Z

    Defect-band photoluminescence (PL) imaging with an InGaAs camera was applied to multicrystalline silicon (mc-Si) wafers, which were taken from different heights of different Si bricks. Neighboring wafers were picked at six different processing steps, from as-cut to post-metallization. By using different cut-off filters, we were able to separate the band-to-band emission images from the defect-band emission images. On the defect-band emission images, the bright regions that originate from the grain boundaries and defect clusters were extracted from the PL images. The area fraction percentage of these regions at various processing stages shows a correlation with the final cell electrical parameters.

  16. Effects of CO2 on H2O band profiles and band strengths in mixed H2O:CO2 ices

    E-Print Network [OSTI]

    Karin I. Oberg; Helen J. Fraser; A. C. Adwin Boogert; Suzanne E. Bisschop; Guido W. Fuchs; Ewine F. van Dishoeck; Harold Linnartz

    2006-10-25T23:59:59.000Z

    H2O is the most abundant component of astrophysical ices. In most lines of sight it is not possible to fit both the H2O 3 um stretching, the 6 um bending and the 13 um libration band intensities with a single pure H2O spectrum. Recent Spitzer observations have revealed CO2 ice in high abundances and it has been suggested that CO2 mixed into H2O ice can affect relative strengths of the 3 um and 6 um bands. We used laboratory infrared transmission spectroscopy of H2O:CO2 ice mixtures to investigate the effects of CO2 on H2O ice spectral features at 15-135 K. We find that the H2O peak profiles and band strengths are significantly different in H2O:CO2 ice mixtures compared to pure H2O ice. In all H2O:CO2 mixtures, a strong free-OH stretching band appears around 2.73 um, which can be used to put an upper limit on the CO2 concentration in the H2O ice. The H2O bending mode profile also changes drastically with CO2 concentration; the broad pure H2O band gives way to two narrow bands as the CO2 concentration is increased. This makes it crucial to constrain the environment of H2O ice to enable correct assignments of other species contributing to the interstellar 6 um absorption band. The amount of CO2 present in the H2O ice of B5:IRS1 is estimated by simultaneously comparing the H2O stretching and bending regions and the CO2 bending mode to laboratory spectra of H2O, CO2, H2O:CO2 and HCOOH.

  17. A Generalized {ital K} Correction for Type Ia Supernovae: Comparing {ital R}-band Photometry Beyond {ital z=9.2} with B,V, and {ital R}-band Nearby Photometry

    E-Print Network [OSTI]

    Goodbar, Ariel

    2008-01-01T23:59:59.000Z

    spectroscopically peculiar supernovae, and to search for anyK Correction for Type Ia Supernovae: Comparing R-bandK Correction for Type Ia Supernovae: Comparing R-band

  18. Valence band hybridization in N-rich GaN1-xAsx alloys

    SciTech Connect (OSTI)

    Wu, J.; Walukiewicz, W.; Yu, K.M.; Denlinger, J.D.; Shan, W.; Ager III, J.W.; Kimura, A.; Tang, H.F.; Kuech, T.F.

    2004-05-04T23:59:59.000Z

    We have used photo-modulated transmission and optical absorption spectroscopies to measure the composition dependence of interband optical transitions in N-rich GaN{sub 1-x}As{sub x} alloys with x up to 0.06. The direct bandgap gradually decreases as x increases. In the dilute x limit, the observed band gap approaches 2.8 eV; this limiting value is attributed to a transition between the As localized level, which has been previously observed in As-doped GaN at 0.6 eV above the valence band maximum in As-doped GaN, and the conduction band minimum. The structure of the valence band of GaN{sub 1-x}As{sub x} is explained by the hybridization of the localized As states with the extended valence band states of GaN matrix. The hybridization is directly confirmed by soft x-ray emission experiments. To describe the electronic structure of the GaN{sub 1-x}As{sub x} alloys in the entire composition range a linear interpolation is used to combine the effects of valence band hybridization in N-rich alloys with conduction band anticrossing in As-rich alloys.

  19. Two-zone heterogeneous structure within shear bands of a bulk metallic glass

    SciTech Connect (OSTI)

    Shao, Yang; Yao, Kefu; Liu, Xue [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China)] [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Li, Mo [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China) [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0245 (United States)

    2013-10-21T23:59:59.000Z

    Shear bands, the main plastic strain carrier in metallic glasses, are severely deformed regions often considered as disordered and featureless. Here we report the observations of a sandwich-like heterogeneous structure inside shear bands in Pd{sub 40.5}Ni{sub 40.5}P{sub 19} metallic glass sample after plastic deformation by high-resolution transmission electron microscopy. The experimental results suggest a two-step plastic deformation mechanism with corresponding microstructure evolution at atomic scale, which may intimately connected to the stability of the shear band propagation and the overall plastic deformability.

  20. A narrow-band speckle-free light source via random Raman lasing

    E-Print Network [OSTI]

    Hokr, Brett H; Bixler, Joel N; Dyer, Phillip N; Noojin, Gary D; Redding, Brandon; Thomas, Robert J; Rockwell, Benjamin A; Cao, Hui; Yakovlev, Vladislav V; Scully, Marlan O

    2015-01-01T23:59:59.000Z

    Currently, no light source exists which is both narrow-band and speckle-free with sufficient brightness for full-field imaging applications. Light emitting diodes (LEDs) are excellent spatially incoherent sources, but are tens of nanometers broad. Lasers on the other hand can produce very narrow-band light, but suffer from high spatial coherence which leads to speckle patterns which distort the image. Here we propose the use of random Raman laser emission as a new kind of light source capable of providing short-pulsed narrow-band speckle-free illumination for imaging applications.

  1. Investigation of shear-banding mechanism in fully dense nanocrystalline Ni sheet

    SciTech Connect (OSTI)

    Zhu Rongtao [Department of Mechanical Engineering, Nanjing University of Technology, Nanjing, Jiangsu 210009 (China); Zhou Jianqiu, E-mail: zhouj@njut.edu.cn [Department of Mechanical Engineering, Nanjing University of Technology, Nanjing, Jiangsu 210009 (China); Li Xinbo; Jiang Hua; Ling Xiang [Department of Mechanical Engineering, Nanjing University of Technology, Nanjing, Jiangsu 210009 (China)

    2010-04-15T23:59:59.000Z

    Evolution of shear banding in fully dense electrodeposited nanocrystalline Ni was successfully monitored by using a digital image correlation technique under a quasi-static uniaxial tensile load. To investigate the microscopic physical mechanism of the shear banding, in-situ tensile testing for the nanocrystalline Ni sample was conducted in a transmission electron microscope and fracture surface of the sample was examined by field emission scanning electron microscope. The results suggest that grain boundary migration based on atomic diffusion is a main carrier of the shear banding.

  2. Emergence of rotational bands in ab initio no-core configuration interaction calculations

    E-Print Network [OSTI]

    M. A. Caprio; P. Maris; J. P. Vary; R. Smith

    2015-02-04T23:59:59.000Z

    Rotational bands have been observed to emerge in ab initio no-core configuration interaction (NCCI) calculations for p-shell nuclei, as evidenced by rotational patterns for excitation energies, electromagnetic moments, and electromagnetic transitions. We investigate the ab initio emergence of nuclear rotation in the Be isotopes, focusing on 9Be for illustration, and make use of basis extrapolation methods to obtain ab initio predictions of rotational band parameters for comparison with experiment. We find robust signatures for rotational motion, which reproduce both qualitative and quantitative features of the experimentally observed bands.

  3. Properties of rotational bands at the spin limit in A $\\sim$ 50, A $\\sim$ 65 and A $\\sim$ 110 nuclei

    E-Print Network [OSTI]

    Janzen, V P; Andrews, H R; Ball, G C; Cameron, J A; Cromaz, M; DeGraaf, J; Flibotte, S; Galindo-Uribarri, A; Hackman, G; Headly, D M; Jonkman, J; Mullins, S M; Radford, D C; Ragnarsson, I; Rodríguez, J L; Svensson, C E; Waddington, J C; Ward, D; Zwartz, G

    1996-01-01T23:59:59.000Z

    Properties of rotational bands at the spin limit in A $\\sim$ 50, A $\\sim$ 65 and A $\\sim$ 110 nuclei

  4. Design and Development of Dual Polarized, Stacked Patch Antenna Element for S-Band Dual-Pol Weather Radar Array

    E-Print Network [OSTI]

    Bhardwaj, Shubhendu

    2012-01-01T23:59:59.000Z

    in Weather Detection . . . . . . . . . . . . . . . . . .for S-Band Weather Radar . . . . . . . . . . . . . Dual-polpatterns of polarimetric weather radars,” Journal of

  5. Ultra-High Gradient Compact S-Band Linac for Laboratory and Industrial Applications

    SciTech Connect (OSTI)

    Faillace, Luigi; /RadiaBeam Tech.; Agustsson, Ronald; /RadiaBeam Tech.; Frigola, Pedro; /RadiaBeam Tech.; Murokh, Alex; /RadiaBeam Tech.; Dolgashev, Valery; /SLAC; Rosenzweig, James; /UCLA

    2012-07-03T23:59:59.000Z

    There is growing demand from the industrial and research communities for high gradient, compact RF accelerating structures. The commonly used S-band SLAC-type structure has an operating gradient of only about 20 MV/m; while much higher operating gradients (up to 70 MV/m) have been recently achieved in X-band, as a consequence of the substantial efforts by the Next Linear Collider (NLC) collaboration to push the performance envelope of RF structures towards higher accelerating gradients. Currently however, high power X-band RF sources are not readily available for industrial applications. Therefore, RadiaBeam Technologies is developing a short, standing wave S-band structure which uses frequency scaled NLC design concepts to achieve up to a 50 MV/m operating gradient at 2856 MHz. The design and prototype commissioning plans are presented.

  6. Field measurements of a swell band, shore normal, flux divergence reversal

    E-Print Network [OSTI]

    Link, Shmuel G

    2011-01-01T23:59:59.000Z

    Throughout this thesis we will discuss the theoretical background and empirical observation of a swell band shore normal flux divergence reversal. Specifically, we will demonstrate the existence and persistence of the ...

  7. Calculation of wakefields in a 17 GHz beam-driven photonic band-gap accelerator structure

    E-Print Network [OSTI]

    Hu, Min

    We present the theoretical analysis and computer simulation of the wakefields in a 17 GHz photonic band-gap (PBG) structure for accelerator applications. Using the commercial code CST Particle Studio, the fundamental ...

  8. Dual-band reflectarrays using microstrip ring elements and their applications with various feeding arrangements

    E-Print Network [OSTI]

    Han, Chul Min

    2006-10-30T23:59:59.000Z

    -fed reflectarray antenna has been designed to demonstrate the dual-band circular polarized operation. The proposed ring structure provides many advantages of compact size, more freedom in the selection of element spacing, less blockage between circuit layers...

  9. Tunable frequency band-gap and pulse propagation in a strongly nonlinear diatomic chain

    E-Print Network [OSTI]

    E. B. Herbold; J. Kim; V. F. Nesterenko; S. Wang; C. Daraio

    2008-06-26T23:59:59.000Z

    One-dimensional nonlinear phononic crystals have been assembled from periodic diatomic chains of stainless steel cylinders alternated with Polytetrafluoroethylene (PTFE) spheres. We report the presence of acoustic band gaps in the dispersion relation of the linearized systems and study the transformation of single and multiple pulses in linear, nonlinear and strongly nonlinear regimes with numerical calculations and experiments. The limiting frequencies of the band gap are within the audible frequency range (20-20,000 Hz) and can be tuned by varying the particle's material properties, mass and initial compression. Pulses rapidly transform within very short distances from the impacted end due to the influence of the band gap in the linear and in nonlinear elastic chains. The effects of an in situ band gap created by a mean dynamic compression are observed in the strongly nonlinear wave regime.

  10. System and Circuit Design Techniques for Silicon-based Multi-band/Multi-standard Receivers

    E-Print Network [OSTI]

    El-Nozahi, Mohamed A.

    2011-08-08T23:59:59.000Z

    by the global trend of developing multi-band/multistandard terminals for low-cost and multifunction transceivers. Exploring the unused 10-66 GHz frequency spectrum for high data rate communication is also another trend in the wireless industry...

  11. Band structure engineering through orbital interaction for enhanced thermoelectric power factor

    SciTech Connect (OSTI)

    Zhu, Hong; Sun, Wenhao; Ceder, Gerbrand [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Armiento, Rickard [Department of Physics, Chemistry and Biology (IFM), Linköping University, SE-58183 Linköping (Sweden); Lazic, Predrag [Theoretical Physics Division, Rudjer Boskovic Institute, Bijenicka Cesta 54, Zagreb (Croatia)

    2014-02-24T23:59:59.000Z

    Band structure engineering for specific electronic or optical properties is essential for the further development of many important technologies including thermoelectrics, optoelectronics, and microelectronics. In this work, we report orbital interaction as a powerful tool to finetune the band structure and the transport properties of charge carriers in bulk crystalline semiconductors. The proposed mechanism of orbital interaction on band structure is demonstrated for IV-VI thermoelectric semiconductors. For IV-VI materials, we find that the convergence of multiple carrier pockets not only displays a strong correlation with the s-p and spin-orbit coupling but also coincides with the enhancement of power factor. Our results suggest a useful path to engineer the band structure and an enticing solid-solution design principle to enhance thermoelectric performance.

  12. Shear Banding and Spatiotemporal Oscillations in Vortex Matter in Nanostructured Superconductors

    E-Print Network [OSTI]

    C. Reichhardt; C. J. Olson Reichhardt

    2009-12-16T23:59:59.000Z

    We propose a simple nanostructured pinning array geometry where a rich variety of complex vortex shear banding phenomena can be realized. A single row of pinning sites is removed from a square pinning array. Shear banding effects arise when vortex motion in the pin-free channel nucleates motion of vortices in the surrounding pinned regions, creating discrete steps in the vortex velocity profile away from the channel. Near the global depinning transition, the width of the band of moving vortices undergoes oscillations or fluctuations that can span the entire system. We use simulations to show that these effects should be observable in the transport properties of the system. Similar large oscillations and shear banding effects are known to occur for sheared complex fluids in which different dynamical phases coexist.

  13. Zone folding effect in Raman G-band intensity of twisted bilayer graphene

    E-Print Network [OSTI]

    Dresselhaus, Mildred

    The G-band Raman intensity is calculated for twisted bilayer graphene as a function of laser excitation energy based on the extended tight binding method. Here we explicitly consider the electron-photon and electron-phonon ...

  14. Investigation of shear banding in three-dimensional foams G. Ovarlez1

    E-Print Network [OSTI]

    stress, this leads to the viscosity bifurcation phenomenon [8,9]. This implies that, in addition) and shear-induced resuspension [11]. Some yield stress fluids seem not to exhibit shear banding, although

  15. Investigation of shear banding in three-dimensional foams G. Ovarlez1

    E-Print Network [OSTI]

    Boyer, Edmond

    average is equal to macro. In macroscopic rheo- metric experiments, under applied stress, this leads-induced resuspension [11]. Some yield stress fluids seem not to exhibit shear banding, although experiments only

  16. Rock Bands/Rock Brands: Mediation and Musical Performance in Post-liberalization Bangalore

    E-Print Network [OSTI]

    Coventry, Chloe Louise

    2013-01-01T23:59:59.000Z

    and the Delhi-based electronica band Midival Punditz (Murthymoney and listening to electronica at swanky clubs; rather,in a kind of lo-fi electronica that is meant to document

  17. F. J. Wild A. C. Jones A. W. Tudhope Investigation of luminescent banding in solid coral

    E-Print Network [OSTI]

    REPORT F. J. Wild á A. C. Jones á A. W. Tudhope Investigation of luminescent banding in solid coral-Verlag 2000 F. J. Wild á A. C. Jones (&) Department of Chemistry, The University of Edinburgh, King

  18. arecibo l-band feed: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Galactic studies with the Arecibo L-band Feed Array (ALFA) is conducting a neutral hydrogen (HI) survey of the whole Arecibo sky (declination range from -1 to 38 degrees), with...

  19. Narrow-Band Absorption-Enhanced Quantum Dot/J-Aggregate Conjugates

    E-Print Network [OSTI]

    Walker, Brian J.

    We report narrow-band absorption enhancement of semiconductor nanocrystals via Förster resonance energy transfer from cyanine J-aggregates. These J-aggregated dyes associate electrostatically with short quantum-dot (QD) ...

  20. Parametric representation of wave propagation in nonuniform media (both in transmission and stop bands)

    E-Print Network [OSTI]

    A. Popov; V. Kovalchuk

    2011-12-06T23:59:59.000Z

    An analytical approach based on the parametric representation of the wave propagation in nonuniform media was considered. In addition to the previously developed theory of parametric antiresonance describing the field attenuation in stop bands, in the present paper the behaviour of the Bloch wave in a transmission band was investigated. A wide class of exact solutions was found and the correspondence to the quasi-periodic Floquet solutions was shown.

  1. On a Limiting Distribution of Singular Values of Random Band Matrices

    E-Print Network [OSTI]

    Anna Lytova; Leonid Pastur

    2015-03-14T23:59:59.000Z

    An equation is obtained for the Stieltjes transform of the normalized distribution of singular values of non-symmetric band random matrices in the limit when the band width and rank of the matrix simultaneously tend to infinity. Conditions under which this limit agrees with the quarter-circle law are found. An interesting particular case of lower triangular random matrices is also considered and certain properties of the corresponding limiting singular value distribution are given.

  2. Solar DEM Models : A solar image in color band b, mn pixels,

    E-Print Network [OSTI]

    Wolfe, Patrick J.

    Solar DEM Models : A solar image in color band b, m×n pixels, containing a particular solar feature, for t = 1, 2, . . . , T. btM sianFieldRandomGaus I M I I bbb T t bbtt bbb bb 2 1 2 )( #12;Solar DEM.bI : the measure error of the ith row and jth column pixel of the certain image in color band b. ijbe #12;Solar DEM

  3. Thermophotovoltaic conversion using selective infrared line emitters and large band gap photovoltaic devices

    DOE Patents [OSTI]

    Brandhorst, Jr., Henry W. (Auburn, AL); Chen, Zheng (Auburn, AL)

    2000-01-01T23:59:59.000Z

    Efficient thermophotovoltaic conversion can be performed using photovoltaic devices with a band gap in the 0.75-1.4 electron volt range, and selective infrared emitters chosen from among the rare earth oxides which are thermally stimulated to emit infrared radiation whose energy very largely corresponds to the aforementioned band gap. It is possible to use thermovoltaic devices operating at relatively high temperatures, up to about 300.degree. C., without seriously impairing the efficiency of energy conversion.

  4. A high-resolution, four-band SAR testbed with real-time image formation

    SciTech Connect (OSTI)

    Walker, B.; Sander, G.; Thompson, M.; Burns, B.; Fellerhoff, R.; Dubbert, D.

    1996-03-01T23:59:59.000Z

    This paper describes the Twin-Otter SAR Testbed developed at Sandia National Laboratories. This SAR is a flexible, adaptable testbed capable of operation on four frequency bands: Ka, Ku, X, and VHF/UHF bands. The SAR features real-time image formation at fine resolution in spotlight and stripmap modes. High-quality images are formed in real time using the overlapped subaperture (OSA) image-formation and phase gradient autofocus (PGA) algorithms.

  5. Band gap engineering for graphene by using Na{sup +} ions

    SciTech Connect (OSTI)

    Sung, S. J.; Lee, P. R.; Kim, J. G.; Ryu, M. T.; Park, H. M.; Chung, J. W., E-mail: jwc@postech.ac.kr [Department of Physics, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

    2014-08-25T23:59:59.000Z

    Despite the noble electronic properties of graphene, its industrial application has been hindered mainly by the absence of a stable means of producing a band gap at the Dirac point (DP). We report a new route to open a band gap (E{sub g}) at DP in a controlled way by depositing positively charged Na{sup +} ions on single layer graphene formed on 6H-SiC(0001) surface. The doping of low energy Na{sup +} ions is found to deplete the ?* band of graphene above the DP, and simultaneously shift the DP downward away from Fermi energy indicating the opening of E{sub g}. The band gap increases with increasing Na{sup +} coverage with a maximum E{sub g}?0.70?eV. Our core-level data, C 1s, Na 2p, and Si 2p, consistently suggest that Na{sup +} ions do not intercalate through graphene, but produce a significant charge asymmetry among the carbon atoms of graphene to cause the opening of a band gap. We thus provide a reliable way of producing and tuning the band gap of graphene by using Na{sup +} ions, which may play a vital role in utilizing graphene in future nano-electronic devices.

  6. Valence band structure of the icosahedral Ag-In-Yb quasicrystal

    SciTech Connect (OSTI)

    Sharma, H. R.; Simutis, G.; Dhanak, V. R.; Nugent, P. J.; McGrath, R. [Surface Science Research Centre and Department of Physics, University of Liverpool, Liverpool L69 3BX (United Kingdom); Cui, C. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Shimoda, M. [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Tsai, A. P. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Ishii, Y. [Department of Physics, Chuo University, Kasuga, Tokyo 112-8551 (Japan)

    2010-03-01T23:59:59.000Z

    The valence band structure of the icosahedral (i) Ag-In-Yb quasicrystal, which is isostructural to the binary i-Cd-Yb system, is investigated by ultraviolet photoemission spectroscopy (UPS). Experimental results are compared with electronic-structure calculations of a cubic approximant of the same phase. UPS spectra from the fivefold, threefold, and twofold i-Ag-In-Yb surfaces reveal that the valence band near to the Fermi level is dominated by Yb 4f-derived states, in agreement with calculations. The spectra also exhibit peaks which are surface core level shifted, caused by changes in the electronic structure in surface layers. Calculations yield a pseudogap in the density of states due to a hybridization of the Yb 5d band with the Ag 5p and In 5p bands. Both experimental and calculated band features are very similar to those of Cd-Yb. The modification of the band structure after surface treatment by sputtering and by oxidation is also studied. Additionally, the work function of i-Ag-In-Yb measured from the width of UPS spectrum is found to be almost unaffected by surface orientation, but increases after sputtering or oxidation.

  7. Electronic band structure and optical properties of the cubic, Sc, Y and La hydride systems

    SciTech Connect (OSTI)

    Peterman, D.J.

    1980-01-01T23:59:59.000Z

    Electronic band structure calculations are used to interpret the optical spectra of the cubic Sc, Y and La hydride systems. Self-consistent band calculations of ScH/sub 2/ and YH/sub 2/ were carried out. The respective joint densities of states are computed and compared to the dielectric functions determined from the optical measurements. Additional calculations were performed in which the Fermi level or band gap energies are rigidly shifted by a small energy increment. These calculations are then used to simulate the derivative structure in thermomodulation spectra and relate the origin of experimental interband features to the calculated energy bands. While good systematic agreement is obtained for several spectral features, the origin of low-energy interband transitions in YH/sub 2/ cannot be explained by these calculated bands. A lattice-size-dependent premature occupation of octahedral sites by hydrogen atoms in the fcc metal lattice is suggested to account for this discrepancy. Various non-self-consistent calculations are used to examine the effect of such a premature occupation. Measurements of the optical absorptivity of LaH/sub x/ with 1.6 < x < 2.9 are presented which, as expected, indicate a more premature occupation of the octahedral sites in the larger LaH/sub 2/ lattice. These experimental results also suggest that, in contrast to recent calculations, LaH/sub 3/ is a small-band-gap semiconductor.

  8. Band gap structure modification of amorphous anodic Al oxide film by Ti-alloying

    SciTech Connect (OSTI)

    Canulescu, S., E-mail: stec@fotonik.dtu.dk; Schou, J. [Department of Photonics Engineering, Technical University of Denmark, 4000 Roskilde (Denmark); Rechendorff, K.; Pleth Nielsen, L. [Danish Technological Institute, Kongsvang Alle 29, 8000 Aarhus (Denmark); Borca, C. N. [Paul Scherrer Institute, 5232 Villigen (Switzerland); Jones, N. C.; Hoffmann, S. V. [ISA, Department of Physics and Astronomy, Aarhus University, 8000 Aarhus (Denmark); Bordo, K.; Ambat, R. [Department of Mechanical Engineering, Technical University of Denmark, 2800 Kongens Lyngby (Denmark)

    2014-03-24T23:59:59.000Z

    The band structure of pure and Ti-alloyed anodic aluminum oxide has been examined as a function of Ti concentration varying from 2 to 20 at.?%. The band gap energy of Ti-alloyed anodic Al oxide decreases with increasing Ti concentration. X-ray absorption spectroscopy reveals that Ti atoms are not located in a TiO{sub 2} unit in the oxide layer, but rather in a mixed Ti-Al oxide layer. The optical band gap energy of the anodic oxide layers was determined by vacuum ultraviolet spectroscopy in the energy range from 4.1 to 9.2?eV (300–135?nm). The results indicate that amorphous anodic Al{sub 2}O{sub 3} has a direct band gap of 7.3?eV, which is about ?1.4?eV lower than its crystalline counterpart (single-crystal Al{sub 2}O{sub 3}). Upon Ti-alloying, extra bands appear within the band gap of amorphous Al{sub 2}O{sub 3}, mainly caused by Ti 3d orbitals localized at the Ti site.

  9. Phase Angle Effects on 3-micron Absorption Band on Ceres: Implications for Dawn Mission

    E-Print Network [OSTI]

    Takir, Driss; Sanchez, Juan A; Corre, Lucille Le; Hardersen, Paul S; Nathues, Andreas

    2015-01-01T23:59:59.000Z

    Phase angle-induced spectral effects are important to characterize since they affect spectral band parameters such as band depth and band center, and therefore skew mineralogical interpretations of planetary bodies via reflectance spectroscopy. Dwarf planet (1) Ceres is the next target of NASA's Dawn mission, which is expected to arrive in March 2015. The visible and near-infrared mapping spectrometer (VIR) onboard Dawn has the spatial and spectral range to characterize the surface between 0.25-5.0 microns. Ceres has an absorption feature at 3.0 microns due to hydroxyl- and/or water-bearing minerals (e.g. Lebofsky et al. 1981, Rivkin et al. 2003). We analyzed phase angle-induced spectral effects on the 3-micron absorption band on Ceres using spectra measured with the long-wavelength cross-dispersed (LXD: 1.9-4.2 microns) mode of the SpeX spectrograph/imager at the NASA Infrared Telescope Facility (IRTF). Ceres LXD spectra were measured at different phase angles ranging from 0.7o to 22o. We found that the band...

  10. Apparatus for producing a thin sample band in a microchannel system

    DOE Patents [OSTI]

    Griffiths, Stewart K. (Livermore, CA; , Nilson, Robert H. (Cardiff, CA)

    2008-05-13T23:59:59.000Z

    The present invention improves the performance of microchannel systems for chemical and biological synthesis and analysis by providing a method and apparatus for producing a thin band of a species sample. Thin sample bands improve the resolution of microchannel separation processes, as well as many other processes requiring precise control of sample size and volume. The new method comprises a series of steps in which a species sample is manipulated by controlled transport through a junction formed at the intersection of four or more channels. A sample is first inserted into the end of one of these channels in the vicinity of the junction. Next, this sample is thinned by transport across the junction one or more times. During these thinning steps, flow enters the junction through one of the channels and exists through those remaining, providing a divergent flow field that progressively stretches and thins the band with each traverse of the junction. The thickness of the resulting sample band may be smaller than the channel width. Moreover, the thickness of the band may be varied and controlled by altering the method alone, without modification to the channel or junction geometries. The invention is applicable to both electroosmotic and electrophoretic transport, to combined electrokinetic transport, and to some special cases in which bulk fluid transport is driven by pressure gradients. It is further applicable to channels that are open, filled with a gel or filled with a porous or granular material.

  11. M dwarf luminosity, radius, and $\\alpha$-enrichment from $I$-band spectral features

    E-Print Network [OSTI]

    Terrien, Ryan C; Bender, Chad F; Deshpande, Rohit; Robertson, Paul

    2015-01-01T23:59:59.000Z

    Despite the ubiquity of M dwarfs and their growing importance to studies of exoplanets, Galactic evolution, and stellar structure, methods for precisely measuring their fundamental stellar properties remain elusive. Existing techniques for measuring M dwarf luminosity, mass, radius, or composition are calibrated over a limited range of stellar parameters or require expensive observations. We find a strong correlation between the $K_S$-band luminosity ($M_K$), the observed strength of the $I$-band sodium doublet absorption feature, and [Fe/H] in M dwarfs without strong H$\\alpha$ emission. We show that the strength of this feature, coupled with [Fe/H] and spectral type, can be used to derive M dwarf $M_K$ and radius without requiring parallax. Additionally, we find promising evidence that the strengths of the $I$-band sodium doublet and the nearby $I$-band calcium triplet may jointly indicate $\\alpha$-element enrichment. The use of these $I$-band features requires only moderate-resolution near-infrared spectros...

  12. Reading data stored in the state of metastable defects in silicon using band-band photoluminescence: Proof of concept and physical limits to the data storage density

    SciTech Connect (OSTI)

    Rougieux, F. E.; Macdonald, D. [Research School of Engineering, College of Engineering and Computer Science, The Australian National University, Canberra, ACT 0200 (Australia)

    2014-03-24T23:59:59.000Z

    The state of bistable defects in crystalline silicon such as iron-boron pairs or the boron-oxygen defect can be changed at room temperature. In this letter, we experimentally demonstrate that the chemical state of a group of defects can be changed to represent a bit of information. The state can then be read without direct contact via the intensity of the emitted band-band photoluminescence signal of the group of defects, via their impact on the carrier lifetime. The theoretical limit of the information density is then computed. The information density is shown to be low for two-dimensional storage but significant for three-dimensional data storage. Finally, we compute the maximum storage capacity as a function of the lower limit of the photoluminescence detector sensitivity.

  13. ARM - Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency Profilers, S-band Radar (williams-s_band)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Williams, Christopher

    This data was collected by the NOAA 449-MHz and 2.8-GHz profilers in support of the Department of Energy (DOE) and NASA sponsored Mid-latitude Continental Convective Cloud Experiment (MC3E). The profiling radars were deployed in Northern Oklahoma at the DOE Atmospheric Radiation Mission (ARM) Southern Great Plans (SGP) Central Facility from 22 April through 6 June 2011. NOAA deployed three instruments: a Parsivel disdrometer, a 2.8-GHz profiler, and a 449-MHz profiler. The parasivel provided surface estimates of the raindrop size distribution and is the reference used to absolutely calibrate the 2.8 GHz profiler. The 2.8-GHz profiler provided unattenuated reflectivity profiles of the precipitation. The 449-MHz profiler provided estimates of the vertical air motion during precipitation from near the surface to just below the freezing level. By using the combination of 2.8-GHz and 449-MHz profiler observations, vertical profiles of raindrop size distributions can be retrieved. The profilers are often reference by their frequency band: the 2.8-GHz profiler operates in the S-band and the 449-MHz profiler operates in the UHF band. The raw observations are available as well as calibrated spectra and moments. This document describes how the instruments were deployed, how the data was collected, and the format of the archived data.

  14. Atomistic full-band simulations of monolayer MoS{sub 2} transistors

    SciTech Connect (OSTI)

    Chang, Jiwon; Register, Leonard F.; Banerjee, Sanjay K. [Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States)] [Microelectronics Research Center, The University of Texas at Austin, Austin, Texas 78758 (United States)

    2013-11-25T23:59:59.000Z

    We study the transport properties of deeply scaled monolayer MoS{sub 2} n-channel metal-oxide-semiconductor field effect transistors (MOSFETs), using full-band ballistic quantum transport simulations, with an atomistic tight-binding Hamiltonian obtained from density functional theory. Our simulations suggest that monolayer MoS{sub 2} MOSFETs can provide near-ideal subthreshold slope, suppression of drain-induced barrier lowering, and gate-induced drain leakage. However, these full-band simulations exhibit limited transconductance. These ballistic simulations also exhibit negative differential resistance (NDR) in the output characteristics associated with the narrow width in energy of the lowest conduction band, but this NDR may be substantially reduced or eliminated by scattering in MoS{sub 2}.

  15. High-Q band edge mode of plasmonic crystals studied by cathodoluminescence

    SciTech Connect (OSTI)

    Honda, Masahiro; Yamamoto, Naoki, E-mail: nyamamot@phys.titech.ac.jp [Department of Physics, Tokyo Institute of Technology, Tokyo 152-8551 (Japan)

    2014-02-24T23:59:59.000Z

    We have investigated the quality factor (Q-factor) of the band edge modes in the plasmonic crystal by a cathodoluminescence technique. We have found that the Q-factor at the ? point depends on the terrace width (D)/period (P) ratio of the plasmonic crystal. The finite-difference time-domain methods predict that the band edge mode at D/P?=?3/4 has a high-Q-factor (Q???250 by Palik's permittivity data and Q???530 by Johnson and Christy's data). The beam-scan spectral images allowed us to visualize the standing surface plasmon polariton waves at the band edge energies, and a high-Q-factor of ?200 was observed at D/P???3/4.

  16. Predicted band structures of III-V semiconductors in wurtzite phase

    E-Print Network [OSTI]

    Amrit De; Craig E. Pryor

    2009-08-13T23:59:59.000Z

    While non-nitride III-V semiconductors typically have a zincblende structure, they may also form wurtzite crystals under pressure or when grown as nanowhiskers. This makes electronic structure calculation difficult since the band structures of wurtzite III-V semiconductors are poorly characterized. We have calculated the electronic band structure for nine III-V semiconductors in the wurtzite phase using transferable empirical pseudopotentials including spin-orbit coupling. We find that all the materials have direct gaps. Our results differ significantly from earlier {\\it ab initio} calculations, and where experimental results are available (InP, InAs and GaAs) our calculated band gaps are in good agreement. We tabulate energies, effective masses, and linear and cubic Dresselhaus zero-field spin-splitting coefficients for the zone-center states. The large zero-field spin-splitting coefficients we find may lead to new functionalities for designing devices that manipulate spin degrees of freedom.

  17. Investigation of crystalline and electronic band alignment properties of GaP/Ge(111) heterostructure

    SciTech Connect (OSTI)

    Dixit, V. K.; Kumar, Shailendra; Singh, S. D.; Khamari, S. K.; Kumar, R.; Tiwari, Pragya; Sharma, T. K.; Oak, S. M. [Raja Ramanna Centre for Advanced Technology, Indore, Madhya Pradesh 452013 (India); Phase, D. M. [UGC-DAE Consortium for Scientific Research, Khandwa Road, Indore, Madhya Pradesh 452001 (India)

    2014-03-03T23:59:59.000Z

    Gallium phosphide (GaP) epitaxial layer and nanostructures are grown on n-Ge(111) substrates using metal organic vapour phase epitaxy. It is confirmed by high resolution x-ray diffraction measurements that the layer is highly crystalline and oriented with the coexistence of two domains, i.e., GaP(111)A and GaP(111)B, with an angle of 60° between them due to the formation of a wurtzite monolayer at the interface. The valence band offset between GaP and Ge is 0.7?±?0.1?eV as determined from the valence band onsets and from Kraut's method. A band alignment diagram for GaP/Ge/GeOx is also constructed which can be used to design monolithic optoelectronic integrated circuits.

  18. Dynamical generation of Floquet Majorana flat bands in s-wave superconductors

    E-Print Network [OSTI]

    Amrit Poudel; Gerardo Ortiz; Lorenza Viola

    2014-12-08T23:59:59.000Z

    We present quantum control techniques to engineer flat bands of symmetry-protected Majorana edge modes in s-wave superconductors. Specifically, we show how periodic control may be employed for designing time-independent effective Hamiltonians, which support $Floquet$ $Majorana$ $flat$ $bands$, starting from equilibrium conditions that are either topologically trivial or only support individual Majorana pairs. In the first approach, a suitable modulation of the chemical potential simultaneously induces Majorana flat bands and dynamically $activates$ a pre-existing chiral symmetry which is responsible for their protection. In the second approach, the application of effective parity kicks dynamically $generates$ a desired chiral symmetry by suppressing chirality-breaking terms in the static Hamiltonian. Our results demonstrate how the use of time-dependent control enlarges the range of possibilities for realizing gapless topological superconductivity, potentially enabling access to topological states of matter that have no known equilibrium counterpart.

  19. Method of manufacturing flexible metallic photonic band gap structures, and structures resulting therefrom

    DOE Patents [OSTI]

    Gupta, Sandhya (Bloomington, MN); Tuttle, Gary L. (Ames, IA); Sigalas, Mihail (Ames, IA); McCalmont, Jonathan S. (Ames, IA); Ho, Kai-Ming (Ames, IA)

    2001-08-14T23:59:59.000Z

    A method of manufacturing a flexible metallic photonic band gap structure operable in the infrared region, comprises the steps of spinning on a first layer of dielectric on a GaAs substrate, imidizing this first layer of dielectric, forming a first metal pattern on this first layer of dielectric, spinning on and imidizing a second layer of dielectric, and then removing the GaAs substrate. This method results in a flexible metallic photonic band gap structure operable with various filter characteristics in the infrared region. This method may be used to construct multi-layer flexible metallic photonic band gap structures. Metal grid defects and dielectric separation layer thicknesses are adjusted to control filter parameters.

  20. ATMOSPHERIC COMPOSITION OF WEAK G BAND STARS: CNO AND Li ABUNDANCES

    SciTech Connect (OSTI)

    Adamczak, Jens; Lambert, David L., E-mail: adamczak@astro.as.utexas.edu [McDonald Observatory, University of Texas, Austin, TX 78712 (United States)

    2013-03-10T23:59:59.000Z

    We determined the chemical composition of a large sample of weak G band stars-a rare class of G and K giants of intermediate mass with unusual abundances of C, N, and Li. We have observed 24 weak G band stars with the 2.7 m Harlan J. Smith Telescope at the McDonald Observatory and derived spectroscopic abundances for C, N, O, and Li, as well as for selected elements from Na-Eu. The results show that the atmospheres of weak G band stars are highly contaminated with CN-cycle products. The C underabundance is about a factor of 20 larger than for normal giants and the {sup 12}C/{sup 13}C ratio approaches the CN-cycle equilibrium value. In addition to the striking CN-cycle signature the strong N overabundance may indicate the presence of partially ON-cycled material in the atmospheres of the weak G band stars. The exact mechanism responsible for the transport of the elements to the surface has yet to be identified but could be induced by rapid rotation of the main sequence progenitors of the stars. The unusually high Li abundances in some of the stars are an indicator for Li production by the Cameron-Fowler mechanism. A quantitative prediction of a weak G band star's Li abundance is complicated by the strong temperature sensitivity of the mechanism and its participants. In addition to the unusual abundances of CN-cycle elements and Li, we find an overabundance of Na that is in accordance with the NeNa chain running in parallel with the CN cycle. Apart from these peculiarities, the element abundances in a weak G band star's atmosphere are consistent with those of normal giants.

  1. Chemical banding revealed by chemical etching in a cold-rolled metastable stainless steel

    SciTech Connect (OSTI)

    Celada, C., E-mail: c.celada@cenim.csic.es [MATERALIA Research Group, Department of Physical Metallurgy, Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Av. Gregorio del Amo 8, 28040 Madrid (Spain); Toda-Caraballo, I., E-mail: it247@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); Kim, B., E-mail: bnk20@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, Pembroke Street, Cambridge CB2 3QZ (United Kingdom); San Martín, D., E-mail: dsm@cenim.csic.es [MATERALIA Research Group, Department of Physical Metallurgy, Centro Nacional de Investigaciones Metalúrgicas (CENIM-CSIC), Av. Gregorio del Amo 8, 28040 Madrid (Spain)

    2013-10-15T23:59:59.000Z

    The current work describes the metallographic characterization of the initial microstructure of a cold rolled precipitation hardening semi-austenitic stainless steel (12Cr–9Ni–4Mo–2Cu–1Ti, in wt.%). The use of the Lichtenegger and Blöch (L–B) color etching solution has been shown to reveal not only the phases present in the microstructure, but also the existence of chemical banding along the rolling direction. The L–B reagent has been found to color the microstructure in bands depending on what alloying elements have segregated to each band. Two-dimensional electron probe microanalysis (EPMA) maps have shown that Ni, Cu and Ti segregate together in the bands, while Cr has an opposite behavior. Mo has a mixed segregation behavior although much weaker than the other elements and more prompt to segregate like Ni does. A direct comparison of light optical micrographs with the EPMA maps of the same area of the microstructure has enable to establish a direct relationship between the alloying element band concentration and the resulting etching color contrast obtained with the L–B reagent. Thermodynamic calculations predict that solidification in this steel takes place with ferrite as the primary phase. Equilibrium partitioning coefficient calculations seem to support the observed segregation patterns. - Highlights: • A cold rolled metastable stainless steel has been characterized thoroughly. • EPMA shows that Ni, Cu and Ti segregate together; Cr in an opposite way. • L–B color etching is sensitive to the segregation of these chemical elements. • This chemical banding has been reduced by applying a homogenization heat treatment. • Partitioning coefficient calculations agree with the observed segregation patterns.

  2. Near-field scanning optical microscopy as a simultaneous probe of fields and band structure of photonic crystals: A computational study

    E-Print Network [OSTI]

    Fan, Shanhui

    optical microscopy NSOM imaging to simultaneously obtain both the eigenfield distribution and the band

  3. RF design of X-band RF deflector for femtosecond diagnostics of LCLS electron beam

    SciTech Connect (OSTI)

    Dolgashev, Valery A.; Wang Juwen [SLAC National Accelerator Laboratory, Menlo Park, CA, 94025 (United States)

    2012-12-21T23:59:59.000Z

    We designed a successful constant impedance traveling wave X-band rf deflector for electron beam diagnostics at the 14 GeV SLAC Linac Coherent Light Source (LCLS). This is the first practical deflector built with a waveguide coupler. The 1-meter rf deflector produces 24 MeV peak transverse kick when powered with 20 MW of 11.424 GHz rf. The design is based on our experience with high gradient X-band accelerating structures. Several deflectors of this design have been built at SLAC and are currently in use. Here we describe the design and distinguishing features of this device.

  4. New Analytical Approach for Computation of Band Structure in One-dimensional Periodic Media

    E-Print Network [OSTI]

    Sina Khorasani; Ali Adibi

    2003-01-31T23:59:59.000Z

    In this paper, we present a new approach for the exact calculation of band structure in one-dimensional periodic media, such as photonic crystals and superlattices, based on the recently reported differential transfer matrix method (DTMM). The media analyzed in this paper can have arbitrary profile of refractive index. We derive a closed form dispersion equation using differential transfer matrix formalism, and simplify it under the assumptions of even symmetry and real-valued wavenumber. We also show that under normal incidence both TE and TM modes must have the same band structure. Several numerical test cases are also studied and discussed.

  5. A Minimal Two-band Model for the Superconducting Fe-pnictides

    SciTech Connect (OSTI)

    Raghu, S.

    2010-03-25T23:59:59.000Z

    Following the discovery of the Fe-pnictide superconductors, LDA band structure calculations showed that the dominant contributions to the spectral weight near the Fermi energy came from the Fe 3d orbitals. The Fermi surface is characterized by two hole surfaces around the {Lambda} point and two electron surfaces around the M point of the 2 Fe/cell Brillouin zone. Here, we describe a 2-band model that reproduces the topology of the LDA Fermi surface and exhibits both ferromagnetic and q = ({pi}, 0) spin density wave (SDW) fluctuations. We argue that this minimal model contains the essential low energy physics of these materials.

  6. Direct measurements of band gap grading in polycrystalline CIGS solar cells

    E-Print Network [OSTI]

    Heinrich, M P; Zhang, Y; Kiowski, O; Powalla, M; Lemmer, U; Slobodskyy, A

    2010-01-01T23:59:59.000Z

    We present direct measurements of depth-resolved band gap variations of CuIn(1-x)Ga(x)Se2 thin-film solar cell absorbers. A new measurement technique combining parallel measurements of local thin-film interference and spectral photoluminescence was developed for this purpose. We find sample-dependent correlation parameters between measured band gap depth and composition profiles, and emphasize the importance of direct measurements. These results bring a quantitative insight into the electronic properties of the solar cells and open a new way to analyze parameters that determine the efficiency of solar cells.

  7. Measurement of wakefield suppression in a detuned x-band accelerator structure

    SciTech Connect (OSTI)

    Adolphsen, C.; Bane, K.; Higo, T.; Kubo, K.; Miller, R.; Ruth, R.; Thompson, K.; Wang, J.

    1994-08-01T23:59:59.000Z

    Research is underway at SLAC to develop accelerator structures for a next generation linear collider. A full-scale prototype X-band structure has been built in which the dipole mode frequencies were detuned to suppress the long-range transverse wakefield by about two orders of magnitude. To verify that the detuning works as expected, a facility to measure the long-range wakefield, called the Accelerator Structure SETup, or ASSET, was constructed in the SLAC Linear Collider (SLC). This paper presents the results from the measurement of the prototype X-band structure with this facility.

  8. Direct measurements of band gap grading in polycrystalline CIGS solar cells

    E-Print Network [OSTI]

    M. P. Heinrich; Z-H. Zhang; Y. Zhang; O. Kiowski; M. Powalla; U. Lemmer; A. Slobodskyy

    2010-09-20T23:59:59.000Z

    We present direct measurements of depth-resolved band gap variations of CuIn(1-x)Ga(x)Se2 thin-film solar cell absorbers. A new measurement technique combining parallel measurements of local thin-film interference and spectral photoluminescence was developed for this purpose. We find sample-dependent correlation parameters between measured band gap depth and composition profiles, and emphasize the importance of direct measurements. These results bring a quantitative insight into the electronic properties of the solar cells and open a new way to analyze parameters that determine the efficiency of solar cells.

  9. Price of Port Huron, MI Liquefied Natural Gas Exports (Dollars per Thousand

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122Commercial ConsumersThousand Cubic Feet)Thousand CubicFeet)(Dollars perCubic

  10. Price of Port Huron, MI Liquefied Natural Gas Exports (Dollars per Thousand

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122Commercial ConsumersThousand Cubic Feet)Thousand CubicFeet)(Dollars

  11. Price of Port Huron, MI Liquefied Natural Gas Exports to Canada (Dollars

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122Commercial ConsumersThousand Cubic Feet)Thousand CubicFeet)(Dollarsper

  12. Price of Port Huron, MI Liquefied Natural Gas Exports to Canada (Dollars

    Annual Energy Outlook 2013 [U.S. Energy Information Administration (EIA)]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33 111 1,613 122Commercial ConsumersThousand Cubic Feet)Thousand CubicFeet)(Dollarsperper

  13. Port Huron, MI Liquefied Natural Gas Exports to Canada (Million Cubic Feet)

    U.S. Energy Information Administration (EIA) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5 Tables July 1996 Energy Information Administration Office ofthroughYear Jan Feb Mar AprYear JanPricePrice5,594.9DecadeDecade(Millionto

  14. Surface Plasmon Polariton Assisted Optical Switching in Noble Metal Nanoparticle Systems: A Sub-Band Gap Approach

    E-Print Network [OSTI]

    Dhara, S

    2015-01-01T23:59:59.000Z

    In a proposed book chapter surface plasmon polariton assisted optical switching in noble metal nanoparticle systems is discussed in the sub-band gap formalism.

  15. L & M band infrared studies of V4332 Sagittarii - detection of the water-ice absorption band at 3.05 microns and the CO fundamental band in emission

    E-Print Network [OSTI]

    Dipankar P. K. Banerjee; Watson P. Varricatt; Nagarhalli M. Ashok

    2004-09-16T23:59:59.000Z

    L and M band observations of the nova-like variable V4332 Sgr are presented. Two significant results are obtained viz. the unusual detection of water ice at 3.05 microns and the fundamental band of 12CO at 4.67 microns in emission. The ice feature is a first detection in a nova-like variable while the CO emission is rarely seen in novae. These results, when considered together with other existing data, imply that V4332 Sgr could be a young object surrounded by a circumstellar disc containing gas, dust and ice. The reason for a nova-like outburst to occur in such a system is unclear. But since planets are believed to form in such disks, it appears plausible that the enigmatic outburst of V4332 Sgr could be due to a planetary infall. We also give a more reliable estimate for an epoch of dust formation around V4332 Sgr which appears to have taken place rather late in 1999 - nearly five years after its outburst.

  16. Infrared Spectroscopy of H3O : The 1 Fundamental Band Jian Tang and Takeshi Oka

    E-Print Network [OSTI]

    Oka, Takeshi

    Infrared Spectroscopy of H3O : The 1 Fundamental Band Jian Tang and Takeshi Oka Department, Illinois 60637 E-mail: t-oka@uchicago.edu Received December 24, 1998 The infrared spectrum of H3O 113.6(1)°. © 1999 Academic Press Key Words: infrared spectroscopy; H3O ; vibration

  17. A Near-Infrared Stellar Spectral Library: III. J-Band Spectra

    E-Print Network [OSTI]

    Arvind C. Ranade; N. M. Ashok; Harinder P. Singh; Ranjan Gupta

    2007-09-28T23:59:59.000Z

    This paper is the third in the series of papers published on near-infrared (NIR) stellar spectral library by Ranade et al. (2004 & 2007). The observations were carried out with 1.2 meter Gurushikhar Infrared Telescope (GIRT), at Mt. Abu, India using a NICMOS3 HgCdTe $256 \\times 256$ NIR array based spectrometer. In paper I (Ranade et al. 2004), H-band spectra of 135 stars at a resolution of $\\sim 16$\\AA & paper II (Ranade et al. 2007), K band spectra of 114 stars at a resolution of $\\sim 22$\\AA were presented. The J-band library being released now consists of 126 stars covering spectral types O5--M8 and luminosity classes I--V. The spectra have a moderate resolution of $\\sim 12.5$\\AA in the J band and have been continuum shape corrected to their respective effective temperatures. The complete set of library in near-infrared (NIR) will serve as a good database for researchers working in the field of stellar population synthesis. The complete library in J, H & K is available online at: http://vo.iucaa.ernet.in/$\\sim$voi/NIR\\_Header.html

  18. FRACTAL SHAPED MICROSTRIP COUPLED LINE BAND PASS FILTERS FOR SUPPRESSION OF 2ND

    E-Print Network [OSTI]

    Tentzeris, Manos

    1 FRACTAL SHAPED MICROSTRIP COUPLED LINE BAND PASS FILTERS FOR SUPPRESSION OF 2ND HARMONIC Il Kwon Koch fractal curves are proposed for the first time. These filters are fabricated on Liquid Crystal, the 2nd harmonic of fractal filters can be significantly suppressed through the use of fractal shapes

  19. Broad-band microwave imaging spectroscopy with a solar-dedicated array

    E-Print Network [OSTI]

    , and to study energy release and particle energization in transient events, requires a solarBroad-band microwave imaging spectroscopy with a solar-dedicated array T.S. Bastiana, D.E. Garyb, S of Maryland, College Park, MD 20742 dSolar Astronomy 264-33, Caltech, Pasadena, CA 91125 ABSTRACT For many

  20. The effect of a multivalley energy band structure on the thermoelectric figure of merit

    E-Print Network [OSTI]

    Boyer, Edmond

    L-49 The effect of a multivalley energy band structure on the thermoelectric figure of merit D. M A comparison is drawn between the dimensionless thermoelectric figure of merit of a multivalleyed semiconductor a multivalleyed semiconductor in thermoelectric applications it is concluded that the beneficial effect

  1. Synchronous Ultra-Wide Band Wireless Sensors Networks for oil and gas exploration

    E-Print Network [OSTI]

    Savazzi, Stefano

    Synchronous Ultra-Wide Band Wireless Sensors Networks for oil and gas exploration Stefano Savazzi1 of new oil and gas reservoir. Seismic exploration requires a large number (500 ÷ 2000 nodes, MAC and network layer to develop wireless sensors networks tailored for oil (and gas) exploration

  2. Intensity profiles of superdeformed bands in Pb isotopes in a two-level mixing model

    SciTech Connect (OSTI)

    Wilson, A. N.; Szigeti, S. S.; Rogers, J. I. [Department of Nuclear Physics, Research School of Physical Sciences and Engineering Australian National University, Canberra, ACT 0200 (Australia); Department of Physics, Australian National University, Canberra, ACT 0200 (Australia); Davidson, P. M. [Department of Nuclear Physics, Research School of Physical Sciences and Engineering Australian National University, Canberra, ACT 0200 (Australia); Cardamone, D. M. [Physics Department, Simon Fraser University, 8888 University Drive, Burnaby, BC V5A 1S6 (Canada)

    2009-01-15T23:59:59.000Z

    A recently developed two-level mixing model of the decay out of superdeformed bands is applied to examine the loss of flux from the yrast superdeformed bands in {sup 192}Pb, {sup 194}Pb, and {sup 196}Pb. Probability distributions for decay to states at normal deformations are calculated at each level. The sensitivity of the results to parameters describing the levels at normal deformation and their coupling to levels in the superdeformed well is explored. It is found that except for narrow ranges of the interaction strength coupling the states, the amount of intensity lost is primarily determined by the ratio of {gamma} decay widths in the normal and superdeformed wells. It is also found that while the model can accommodate the observed fractional intensity loss profiles for decay from bands at relatively high excitation, it cannot accommodate the similarly abrupt decay from bands at lower energies if standard estimates of the properties of the states in the first minimum are employed.

  3. Characterization of Graphene-based Nano-antennas in the Terahertz Band

    E-Print Network [OSTI]

    Politècnica de Catalunya, Universitat

    Characterization of Graphene-based Nano-antennas in the Terahertz Band (Invited Paper) Ignacio and Communication Technology, KTH Royal Institute of Technology, 16640 Kista, Sweden Email: lemme@kth.se Abstract--Graphene communications at the nanoscale. Indeed, graphene- based nano-antennas just a few micrometers in size have been

  4. JOURNAL OF MATERIALS SCIENCE 37 (2002) 2441 2446 Influence of L uders bands on magnetic

    E-Print Network [OSTI]

    Clapham, Lynann

    2002-01-01T23:59:59.000Z

    is primarily utilized for the detection of corrosion defects in oil and gas pipelines [6, 7]. As most and gas pipelines during in-service aging act as stress raisers as these pipelines are operated at up. The MFL results indicate that magnetic flux leaks out into the air from regions with L ¨uders bands due

  5. Off-The-Grid X-band Weather Radar Network for the West

    E-Print Network [OSTI]

    Gilbes, Fernando

    and target. CayeyNWS radar Mayaguez The Problem #12;Puerto Rico Test Bed · Multi-level Research Team · Low · Relay Stations #12;Network Node · Weather Radar · Processing Computer · Wireless Link #12;X-Band Weather cost · Better Merging algorithms · More Radars.... #12;PR Test Bed Team #12;Questions · ??? #12;Live

  6. Goncu, JASA-EL Exploiting pattern transformation to tune phononic band

    E-Print Network [OSTI]

    Luding, Stefan

    .05 × 103 kg/m3 , Young's modulus Er = 360 kPa, shear modulus Gr = 120 kPa and longitudinal speed of sound . The attenuation of electromagnetic, acoustic or elastic waves in certain frequency ranges known as band gaps numerically the propagation of elastic waves in a 2D bi-disperse granular crystal composed of large (and soft

  7. PHYSICAL NATURE OF SHEAR BANDS FORMATION AND CONSTITUTIVE MODELLING FOR PLASTIC INSTABILITY

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    697 PHYSICAL NATURE OF SHEAR BANDS FORMATION AND CONSTITUTIVE MODELLING FOR PLASTIC INSTABILITYtokrzyska 21,00-049 Warsaw,Poland Revue Phys. Appl. 23 (1988) 697 AVRIL 1988, Studies of plastic deformation dependent hardening property can be pivotal in the modelling for plastic deform- ation instability

  8. Sea ice extent mapping using Ku band scatterometer data Quinn P. Remund and David G. Long

    E-Print Network [OSTI]

    Long, David G.

    Sea ice extent mapping using Ku band scatterometer data Quinn P. Remund and David G. Long enhancement techniques can be used to increase the utility of scatterometer data in monitoring sea-ice extent is the incidence angle dependence of o . Dual-polarization A and B parameters are used to identify sea ice

  9. STRUCTURE DE BANDES DES CRISTAUX DE TYPE WURTZITE TRANSITIONS OPTIQUES INTRINSQUES DANS LE CdS.

    E-Print Network [OSTI]

    Boyer, Edmond

    825. STRUCTURE DE BANDES DES CRISTAUX DE TYPE WURTZITE TRANSITIONS OPTIQUES INTRINSČQUES DANS LE Cd Brillouin pour des cristaux de type wurtzite est déduite des considérations de la théorie des groupes. Le Cd d'excitons. Un second article traite le problčme de l'exciton dans les cristaux de type wurtzite

  10. Unoccupied band structure of wurtzite GaN,,0001... T. Valla and P. D. Johnson

    E-Print Network [OSTI]

    Homes, Christopher C.

    Unoccupied band structure of wurtzite GaN,,0001... T. Valla and P. D. Johnson Department of Physics of the unoccupied states of thin-film n-type wurtzite GaN. For incident electron energies below 30 eV, free of electronic devices based on heteroepitaxially grown wurtzite films of these nitrides.1 Extensive investiga

  11. Bandgap and band discontinuity in wurtzite/zincblende GaAs homomaterial heterostructure

    E-Print Network [OSTI]

    Shalish, Ilan

    Bandgap and band discontinuity in wurtzite/zincblende GaAs homomaterial heterostructure Ron Gurwitz (Received 28 January 2012; accepted 21 April 2012; published online 9 May 2012) A wurtzite GaAs epilayer photovoltage spectroscopy. The wurtzite structure of the epilayer is disclosed by scanning electron microscope

  12. Band offsets at zincblende-wurtzite GaAs nanowire sidewall surfaces P. Capiod,1

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    Band offsets at zincblende-wurtzite GaAs nanowire sidewall surfaces P. Capiod,1 T. Xu,1,2 J. P. Nys of zincblende (ZB)-wurtzite (WZ) GaAs nanowires are investigated by scanning tunneling spectroscopy and density inclusions consisting of zinc-blende (ZB) and wurtzite (WZ) segments form during the growth of NWs and where

  13. Photonic band structures of periodic arrays of pores in a metallic host

    E-Print Network [OSTI]

    Stroud, David

    . Scherer, O. Painter, B. D'Urso, R. Lee, and A. Yariv, "InGaAsP photonic band gap crystal membrane mi Crystal Waveguides," Phys. Rev. Lett. 77, 3787­3790 (1996). 6. O. Painter, R. K. Lee, A. Scherer, A. Yariv Spontaneous Emission in Solid-State Physics and Electronics," Phys. Rev. Lett. 58, 2059­2062 (1987). 4. A

  14. A low RF-band impedance spectroscopy based sensor for in-situ, wireless soil sensing

    E-Print Network [OSTI]

    Kumar, Ratnesh

    1 A low RF-band impedance spectroscopy based sensor for in-situ, wireless soil sensing Gunjan of impedance spectroscopy. Impedance measurement at multiple frequencies is done by comparing the amplitude impedance of the board in the measurements to minimize the errors. Measurements of both real and imaginary

  15. New Reconfigurable Power Divider Based on Radial Waveguide and Cylindrical Electromagnetic Band Gap Structure for Low

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Structure for Low Power and Low Cost Smart Antenna Systems Halim Boutayeb, Paul Watson and Toby Kemp AntennaNew Reconfigurable Power Divider Based on Radial Waveguide and Cylindrical Electromagnetic Band Gap halim.boutayeb@huawei.com Abstract--A new low power and low cost technique is proposed for designing

  16. Ultrathin, high-efficiency, broad-band, omni-acceptance, organic solar cells enhanced by

    E-Print Network [OSTI]

    Ultrathin, high-efficiency, broad-band, omni- acceptance, organic solar cells enhanced by plasmonic: Three of central challenges in solar cells are high light coupling into solar cell, high light trapping and demonstration of a new ultra-thin high- efficiency organic solar cell (SC), termed "plasmonic cavity

  17. Near-band edge optical properties of exfoliated h-BN layers , J. Barjon

    E-Print Network [OSTI]

    Near-band edge optical properties of exfoliated h-BN layers J. Loayza 1,2 , J. Barjon 2 , A when it is supported by a h-BN film, in particular when mechanically exfoliated from h-BN crystallites layers have been obtained by mechanically exfoliating small crystallites. Exfoliated flakes were reported

  18. Exploiting pattern transformation to tune phononic band gaps in a two-dimensional granular crystal

    E-Print Network [OSTI]

    ) cylinders is investigated numerically. This system was previously shown to undergo a pattern transformation with uniaxial compression by Go¨ncu¨ et al. [Soft Matter 7, 2321 (2011)]. The dispersion relations, or elastic waves in certain frequency ranges known as band gaps is an important feature of these materials

  19. C-band side-entry Ge quantum-well electroabsorption modulator on SOI

    E-Print Network [OSTI]

    Miller, David A. B.

    C-band side-entry Ge quantum-well electroabsorption modulator on SOI operating at 1 V swing J. Modulation was due to the quantum-confined Stark effect from ten Ge/SiGe quantum wells epitaxially grown the totally internally reflecting air-SiGe interface and a frustrated total internal reflection from

  20. New multi-rod linear actuator for direct-drive, wide mechanical band pass

    E-Print Network [OSTI]

    Boyer, Edmond

    (e.g. gears). This mechanical transmission is required in order to adapt the load to a standard motor), · reducing noise, · increasing movement control, · widening the mechanical band pass, · lowering maintenance. For automation applications, such as command (plane command, hard disk harm) or regulation (vibration

  1. Solar DEM Model Proposal : A solar image in color band b, mn pixels,

    E-Print Network [OSTI]

    Wolfe, Patrick J.

    Solar DEM Model Proposal : A solar image in color band b, m×n pixels, containing a particular solar 11 )( #12;Solar DEM Model Proposal : the volume (abundance?) of ion ii : the proportion of the total volume at temperature t t T t bitt I i ib MIE 11 )( #12;Solar Dataset · 15 Filters.txt files

  2. Monte Carlo Simulation of Radiation in Gases with a NarrowBand Model

    E-Print Network [OSTI]

    Dufresne, Jean-Louis

    , France (\\Phi) now at the Institute of Energy and Power Plant Technology, TH Darmstadt, 64287 DarmstadtMonte Carlo Simulation of Radiation in Gases with a Narrow­Band Model and a Net is used for simulation of radiative heat transfers in non­gray gases. The proposed procedure is based

  3. Formation of bands and ridges on Europa by cyclic deformation: Insights from analogue wax experiments

    E-Print Network [OSTI]

    Manga, Michael

    Formation of bands and ridges on Europa by cyclic deformation: Insights from analogue wax perform a set of analogue wax experiments aimed at understanding the processes and conditions that lead to lineament formation on Europa. We heat a layer of wax from below and cool it from above so that a solid

  4. Unifier: Unifying Cache Management and Communication Buffer Management for PVFS over InfiniBand

    E-Print Network [OSTI]

    Panda, Dhabaleswar K.

    , and National Science Foundation's grants #EIA- 9986052, #CCR-0204429, and #CCR-0311542.Ą Work done whileBand Jiesheng Wu1 ˇ Pete Wyckoff2 Dhabaleswar Panda1 Rob Ross3 1 Computer and Information Science The Ohio State Columbus, OH 43212 pw@osc.edu 3 Mathematics and Computer Science Division Argonne National Laboratory

  5. Unifier: Unifying Cache Management and Communication Buffer Management for PVFS over InfiniBand

    E-Print Network [OSTI]

    Panda, Dhabaleswar K.

    , and National Science Foundation's grants #EIA- 9986052, #CCR-0204429, and #CCR-0311542.Ą Work done in partBand Jiesheng Wu1 ˇ Pete Wyckoff2 Dhabaleswar Panda1 Rob Ross3 1 Computer and Information Science The Ohio State Columbus, OH 43212 pw@osc.edu 3 Mathematics and Computer Science Division Argonne National Laboratory

  6. A narrow-band high-speed switched-capacitor sixth order bandpass ladder filter 

    E-Print Network [OSTI]

    Adut, Jozef

    2002-01-01T23:59:59.000Z

    In narrow-band high-speed switched-capacitor filters, the main limitation comes from the capacitance spread and from amplifier settling time. A secondary clock, that averages at an integer fraction of the main clock signal, is used to reduce...

  7. Time-dependent model for diluted magnetic semiconductors including band structure and confinement effects

    E-Print Network [OSTI]

    Boyer, Edmond

    Time-dependent model for diluted magnetic semiconductors including band structure and confinement dynamics in confined diluted magnetic semiconductors induced by laser. The hole-spin relaxation process light-induced magnetization dynamics in ferro- magnetic films and in diluted magnetic semiconductors DMS

  8. High Performance MPI on IBM 12x InfiniBand Architecture Abhinav Vishnu Brad Benton

    E-Print Network [OSTI]

    Panda, Dhabaleswar K.

    . Panda Network Based Computing Lab Department of Computer Science and Engineering The Ohio StateHigh Performance MPI on IBM 12x InfiniBand Architecture Abhinav Vishnu Brad Benton Dhabaleswar K University {vishnu, panda}@cse.ohio-state.edu IBM Austin 11501 Burnet Road Austin, TX 78758 {brad.benton}@us.ibm

  9. VEGETATION CLASSIFICATION USING SEASONAL VARIATIONS OF SCATTEROMETER DATA AT C-BAND AND

    E-Print Network [OSTI]

    Long, David G.

    VEGETATION CLASSIFICATION USING SEASONAL VARIATIONS OF SCATTEROMETER DATA AT C-BAND AND KU for submission to the university library. Date Dr. David Long Chair, Graduate Committee Accepted of Engineering and Technology #12;ABSTRACT VEGETATION CLASSIFICATION USING SEASONAL VARIATIONS OF SCATTEROMETER

  10. The Electrical and Band-Gap Properties of Amorphous Zinc-Indium-Tin Oxide Thin Films

    E-Print Network [OSTI]

    Shahriar, Selim

    MRSEC The Electrical and Band-Gap Properties of Amorphous Zinc-Indium-Tin Oxide Thin Films D Science & Engineering Center For zinc-indium-tin oxide (ZITO) films, grown by pulsed-laser deposition was replaced by substitution with zinc and tin in equal molar proportions (co-substitution). All ZITO films

  11. Energy Band-Gap Engineering of Graphene Nanoribbons Melinda Y. Han,1

    E-Print Network [OSTI]

    Kim, Philip

    , New York, New York 10027, USA 2 Department of Physics, Columbia University, New York, New York 10027Energy Band-Gap Engineering of Graphene Nanoribbons Melinda Y. Han,1 Barbaros O¨ zyilmaz,2 Yuanbo an energy gap near the charge neutrality point. Individual graphene layers are contacted with metal

  12. High-Efficiency X-Band MMIC GaN Power Amplifiers Operating as Rectifiers

    E-Print Network [OSTI]

    Popovic, Zoya

    High-Efficiency X-Band MMIC GaN Power Amplifiers Operating as Rectifiers Michael Litchfield, Scott two 10 x 100j.Lm power combined devices. The MMICs exhibit 67% and 56% power added efficiency at VDD a RF-to-DC efficiency of 64%. The output powers of the two MMIC PAs are around 3.2W. In rectifier mode

  13. Maximum Theoretical Efficiency Limit of Photovoltaic Devices: Effect of Band Structure on Excited State Entropy

    E-Print Network [OSTI]

    Osterloh, Frank

    Maximum Theoretical Efficiency Limit of Photovoltaic Devices: Effect of Band Structure on Excited a theoretical limit for the maximum energy conversion efficiency of single junction photovoltaic cells for the efficiency variations observed for real photovoltaic devices today.4-6 Here, we show that the extractable

  14. A Generalization of the Rainbow Band Separation Attack and its Applications to

    E-Print Network [OSTI]

    Recovery Attack, Rainbow, Enhanced STS, Enhanced TTS, MFE, Diophantine Equations, MQQ-Enc, MQQ-Sig 1-trivial generaliza- tion of the well known Unbalanced Oil and Vinegar (UOV) signature scheme (Eurocrypt '99) minimizing the length of the signatures. By now the Rainbow Band Separation attack is the best key recovery

  15. THE EFFECT OF MEMORY INCLUSION ON MUTUAL INFORMATION BETWEEN SPEECH FREQUENCY BANDS

    E-Print Network [OSTI]

    Kabal, Peter

    through bandwidth extension (BWE) attempts to regenerate the low (20­300 Hz) and high band (3.4­8 k compatibility with existing networks. In contrast to the abundance of published research on BWE tech- niques. This initial attempt, however, did not present a mean- ingful conclusion in terms of BWE. This work

  16. Low-order-mode harmonic multiplying gyrotron traveling-wave amplifier in W band

    SciTech Connect (OSTI)

    Yeh, Y. S.; Chen, C. H.; Yang, S. J.; Lai, C. H.; Lin, T. Y.; Lo, Y. C.; Hong, J. W. [Department of Electro-Optical Engineering, Southern Taiwan University, Tainan, Taiwan (China); Hung, C. L. [Department of Communication Engineering, National Penghu University of Science and Technology, Penghu, Taiwan (China); Chang, T. H. [Department of Physics, National Tsing Hua University, Hsinchu, Taiwan (China)

    2012-09-15T23:59:59.000Z

    Harmonic multiplying gyrotron traveling-wave amplifiers (gyro-TWAs) allow for magnetic field reduction and frequency multiplication. To avoid absolute instabilities, this work proposes a W-band harmonic multiplying gyro-TWA operating at low-order modes. By amplifying a fundamental harmonic TE{sub 11} drive wave, the second harmonic component of the beam current initiates a TE{sub 21} wave to be amplified. Absolute instabilities in the gyro-TWA are suppressed by shortening the interaction circuit and increasing wall losses. Simulation results reveal that compared with Ka-band gyro-TWTs, the lower wall losses effectively suppress absolute instabilities in the W-band gyro-TWA. However, a global reflective oscillation occurs as the wall losses decrease. Increasing the length or resistivity of the lossy section can reduce the feedback of the oscillation to stabilize the amplifier. The W-band harmonic multiplying gyro-TWA is predicted to yield a peak output power of 111 kW at 98 GHz with an efficiency of 25%, a saturated gain of 26 dB, and a bandwidth of 1.6 GHz for a 60 kV, 7.5 A electron beam with an axial velocity spread of 8%.

  17. Integrated Polymer Optoelectronic Time Delay Device for an X-band Phased Array Antenna System

    E-Print Network [OSTI]

    Chen, Ray

    Integrated Polymer Optoelectronic Time Delay Device for an X-band Phased Array Antenna System Brie ABSTRACT A 4-bit polymer optoelectronic true time delay device is demonstrated. The device is composed of monolithically integrated, low loss, passive polymer waveguide delay lines and 2x2 polymer thermo-optic switches

  18. InN/GaN Superlattices: Band Structures and Their Pressure Dependence Iza Gorczyca1

    E-Print Network [OSTI]

    Svane, Axel Torstein

    InN/GaN Superlattices: Band Structures and Their Pressure Dependence Iza Gorczyca1Ă , Tadek Suski1; published online May 20, 2013 Creation of short-period InN/GaN superlattices is one of the possible ways with one monolayer of InN and 40 monolayers of GaN. The results are compared with calculations performed

  19. Band engineering of GaN/AlN quantum wells by Si dopants

    SciTech Connect (OSTI)

    Zhuo, Xiaolong; Ni, Jianchao; Li, Jinchai; Lin, Wei; Cai, Duanjun; Li, Shuping, E-mail: lsp@xmu.edu.cn, E-mail: jykang@xmu.edu.cn; Kang, Junyong, E-mail: lsp@xmu.edu.cn, E-mail: jykang@xmu.edu.cn [Fujian Key Laboratory of Semiconductor Materials and Applications, Department of Physics, Xiamen University, Xiamen 361005 (China)

    2014-03-28T23:59:59.000Z

    The electronic properties of GaN/AlN quantum wells are engineered by Si doped in different positions with the aid of the first-principle calculations. The local potential where the dopant located is dragged down as a result of negative center induced by the Si atom, leading to a different shift of the potential, and further affects the band bending and carrier distribution. The band profiles are depicted by analyzing the projected densities of states, it is found that the different positions of Si doping lead to a different band bending owing to the modified polarization fields. The spatial distributions of electrons and holes plotted by the partial charge densities reveal that electrons and holes experience redistribution by Si dopant in different positions. The above results demonstrate that the effect of polarization on the band bending has been significantly modulated by Si doped in different positions. Such modification of electronic structure is especially valuable for the fabrication of GaN/AlN QWs under desired control.

  20. Band gap reduction in GaNSb alloys due to the anion mismatch

    SciTech Connect (OSTI)

    Veal, T.D.; Piper, L.F.J.; Jollands, S.; Bennett, B.R.; Jefferson, P.H.; Thomas, P.A.; McConville, C.F.; Murdin, B.N.; Buckle, L.; Smith, G.W.; Ashley, T. [Department of Physics, University of Warwick, Coventry, CV4 7AL (United Kingdom); School of Electronics and Physical Sciences, University of Surrey, Guildford, GU2 5XH (United Kingdom); QinetiQ Ltd., St. Andrews Road, Malvern, Worcestershire, WR14 3PS (United Kingdom)

    2005-09-26T23:59:59.000Z

    The structural and optoelectronic properties in GaN{sub x}Sb{sub 1-x} alloys (0{<=}x<0.02) grown by molecular-beam epitaxy on both GaSb substrates and AlSb buffer layers on GaAs substrates are investigated. High-resolution x-ray diffraction (XRD) and reciprocal space mapping indicate that the GaN{sub x}Sb{sub 1-x} epilayers are of high crystalline quality and the alloy composition is found to be independent of substrate, for identical growth conditions. The band gap of the GaNSb alloys is found to decrease with increasing nitrogen content from absorption spectroscopy. Strain-induced band-gap shifts, Moss-Burstein effects, and band renormalization were ruled out by XRD and Hall measurements. The band-gap reduction is solely due to the substitution of dilute amounts of highly electronegative nitrogen for antimony, and is greater than observed in GaNAs with the same N content.

  1. the normal modes. The appearance of the broad band series between 2700 and 1900 cm1

    E-Print Network [OSTI]

    Liang, Haiyi

    density rechargeable lithium-ion batteries self-assembled from graphite oxide nanoplatelets-salt of graphite oxide that ketone functionalities must be present in the GO structure. Deuterium ex- change over graphite oxide imposes a shift of all OH re- lated bands, allowing for clear distinction between C­ OH

  2. A narrow-band high-speed switched-capacitor sixth order bandpass ladder filter

    E-Print Network [OSTI]

    Adut, Jozef

    2002-01-01T23:59:59.000Z

    In narrow-band high-speed switched-capacitor filters, the main limitation comes from the capacitance spread and from amplifier settling time. A secondary clock, that averages at an integer fraction of the main clock signal, is used to reduce...

  3. OUTFLOWS AND DARK BANDS AT ARCADE-LIKE ACTIVE REGION CORE BOUNDARIES

    SciTech Connect (OSTI)

    Scott, J. T.; Martens, P. C. H.; Tarr, L. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2013-03-10T23:59:59.000Z

    Observations from the EUV Imaging Spectrometer (EIS) on board Hinode have revealed outflows and non-thermal line broadening in low intensity regions at the edges of active regions (ARs). We use data from Hinode's EIS, Solar Dynamic Observatory's Atmospheric Imaging Assembly and Helioseismic and Magnetic Imager, and the Transition Region and Coronal Explorer instrument to investigate the boundaries of arcade-like AR cores for NOAA ARs 11112, 10978, and 9077. A narrow, low intensity region that is observed at the core's periphery as a dark band shows outflows and increased spectral line broadening. This dark band is found to exist for days and appears between the bright coronal loop structures of different coronal topologies. We find a case where the dark band region is formed between the magnetic field from emerging flux and the field of the pre-existing flux. A magnetic field extrapolation indicates that this dark band is coincident with the spine lines or magnetic separatrices in the extrapolated field. This occurs over unipolar regions where the brightened coronal field is separated in connectivity and topology. This separation does not appear to be infinitesimal and an initial estimate of the minimum distance of separation is found to be Almost-Equal-To 1.5-3.5 Mm.

  4. Observation of precursorlike behavior of femtosecond pulses in a dye with a strong absorption band

    E-Print Network [OSTI]

    Springer, Matthew M.; Yang, Wenlong; Kolomenski, Alexandre A.; Schuessler, Hans A.; Strohaber, James; Kattawar, George W.; Sokolov, Alexei V.

    2011-01-01T23:59:59.000Z

    absorption band and anomalous dispersion at a wavelength of approximately 800 nm. We explore this regime experimentally with sub-10-fs pulses with a central wavelength of approximately 800 nm from a Ti : sapphire oscillator. The pulses are passed through a...

  5. Birds of Prey and the Band-Tailed Pigeon on Isla Guadalupe, Mexico

    E-Print Network [OSTI]

    ... BIRDS OF PREY AND THE BAND-TAILED PIGEON ON ISLA GUADALUPE, MEXICO JUAN-PABLO GALLO-REYNOSO, Centro de Investigación en Alimentación ... nascent recovery, such studies should be encouraged. Mexico has taken a major step toward the island’s conservation by declaring ...

  6. A Compact X-Band Linac for an X-Ray FEL

    SciTech Connect (OSTI)

    Adolphsen, Chris; Huang, Zhirong; Bane, Karl L.F.; Li, Zenghai; Zhou, Feng; Wang, Faya; Nantista, Christopher D.; /SLAC

    2011-09-12T23:59:59.000Z

    With the growing demand for FEL light sources, cost issues are being reevaluated. To make the machines more compact, higher frequency room temperature linacs are being considered, specifically ones using C-band (5.7 GHz) rf technology, for which 40 MV/m gradients are achievable. In this paper, we show that an X-band (11.4 GHz) linac using the technology developed for NLC/GLC can provide an even lower cost solution. In particular, stable operation is possible at gradients of 100 MV/m for single bunch operation and 70 MV/m for multibunch operation. The concern, of course, is whether the stronger wakefields will lead to unacceptable emittance dilution. However, we show that the small emittances produced in a 250 MeV, low bunch charge, LCLS-like S-band injector and bunch compressor can be preserved in a multi-GeV X-band linac with reasonable alignment tolerances. The successful lasing and operation of the LCLS [1] has generated world-wide interest in X-ray FELs. The demand for access to such a light source by researchers eager to harness the capabilities of this new tool far exceeds the numbers that can be accommodated, spurring plans for additional facilities. Along with cost, spatial considerations become increasingly important for a hard X-ray machine driven by a multi-GeV linac. The consequent need for high acceleration gradient focuses attention on higher frequency normal conducting accelerator technology, rather than the superconducting technology of a soft X-ray facility like FLASH. C-band technology, such as used by Spring-8, is a popular option, capable of providing 40 MV/m. However, more than a decade of R&D toward an X-band linear collider, centered at SLAC and KEK, has demonstrated that this frequency option can extend the gradient reach to the 70-100 MV/m range. The following design and beam dynamics calculations show an X-band linac to be an attractive choice on which to base an X-ray FEL.

  7. Beam Dynamics Study of X-Band Linac Driven X-Ray FELS

    SciTech Connect (OSTI)

    Adolphsen, C.; Limborg-Deprey, C.; Raubenheimer, T.O.; Wu, J.; /SLAC; Sun, Y.; /SLAC

    2011-12-13T23:59:59.000Z

    Several linac driven X-ray Free Electron Lasers (XFELs) are being developed to provide high brightness photon beams with very short, tunable wavelengths. In this paper, three XFEL configurations are proposed that achieve LCLS-like performance using X-band linac drivers. These linacs are more versatile, efficient and compact than ones using S-band or C-band rf technology. For each of the designs, the overall accelerator layout and the shaping of the bunch longitudinal phase space are described briefly. During the last 40 years, the photon wavelengths from linac driven FELs have been pushed shorter by increasing the electron beam energy and adopting shorter period undulators. Recently, the wavelengths have reached the X-ray range, with FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source) successfully providing users with soft and hard X-rays, respectively. FLASH uses a 1.2 GeV L-band (1.3 GHz) superconducting linac driver and can deliver 10-70 fs FWHM long photon pulses in a wavelength range of 44 nm to 4.1 nm. LCLS uses the last third of the SLAC 3 km S-band (2.856 GHz) normal-conducting linac to produce 3.5 GeV to 15 GeV bunches to generate soft and hard X-rays with good spatial coherence at wavelengths from 2.2 nm to 0.12 nm. Newer XFELs (at Spring8 and PSI) use C-band (5.7 GHz) normal-conducting linac drivers, which can sustain higher acceleration gradients, and hence shorten the linac length, and are more efficient at converting rf energy to bunch energy. The X-band (11.4 GHz) rf technology developed for NLC/GLC offers even higher gradients and efficiencies, and the shorter rf wavelength allows more versatility in longitudinal bunch phase space compression and manipulation. In the following sections, three different configurations of X-band linac driven XFELs are described that operate from 6 to 14 GeV. The first (LOW CHARGE DESIGN) has an electron bunch charge of only 10 pC; the second (OPTICS LINEARIZATION DESIGN) is based on optics linearization of the longitudinal phase space in the first stage bunch compressor and can operate with either a high (250 pC) or low (20 pC) bunch charge; and the third (LCLS INJECTOR DESIGN) is similar to LCLS but uses an X-band linac after the first stage bunch compressor at 250 MeV to achieve a final beam energy up to 14 GeV. Compared with LCLS, these X-band linacs are at least a factor of three shorter.

  8. THE MULTIWAVELENGTH SURVEY BY YALE-CHILE (MUSYC): DEEP MEDIUM-BAND OPTICAL IMAGING AND HIGH-QUALITY 32-BAND PHOTOMETRIC REDSHIFTS IN THE ECDF-S

    SciTech Connect (OSTI)

    Cardamone, Carolin N.; Van Dokkum, Pieter G.; Urry, C. Megan; Brammer, Gabriel [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Taniguchi, Yoshi [Research Center for Space and Cosmic Evolution, Ehime University, Bunkyo-cho 2-5, Matsuyama 790-8577 (Japan); Gawiser, Eric; Bond, Nicholas [Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854-8019 (United States); Taylor, Edward; Damen, Maaike [Sterrewacht Leiden, Leiden University, NL-2300 RA Leiden (Netherlands); Treister, Ezequiel [Institute for Astronomy, 2680 Woodlawn Drive, University of Hawaii, Honolulu, HI 96822 (United States); Cobb, Bethany E. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Schawinski, Kevin [Yale Center for Astronomy and Astrophysics, Yale University, P.O. Box 208121, New Haven, CT 06520 (United States); Lira, Paulina [Departamento de Astronoma, Universidad de Chile, Casilla 36-D, Santiago (Chile); Murayama, Takashi [Astronomical Institute, Graduate School of Science, Tohoku University, Aramaki, Aoba, Sendai 980-8578 (Japan); Saito, Tomoki [Institute for Physics and Mathematics of the Universe, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8583 (Japan); Sumikawa, Kentaro, E-mail: carolin.cardamone@astro.yale.ed [Graduate School of Science and Engineering, Ehime University, Bunkyo-cho, Matsuyama 790-8577 (Japan)

    2010-08-15T23:59:59.000Z

    We present deep optical 18-medium-band photometry from the Subaru telescope over the {approx}30' x 30' Extended Chandra Deep Field-South, as part of the Multiwavelength Survey by Yale-Chile (MUSYC). This field has a wealth of ground- and space-based ancillary data, and contains the GOODS-South field and the Hubble Ultra Deep Field. We combine the Subaru imaging with existing UBVRIzJHK and Spitzer IRAC images to create a uniform catalog. Detecting sources in the MUSYC 'BVR' image we find {approx}40,000 galaxies with R {sub AB} < 25.3, the median 5{sigma} limit of the 18 medium bands. Photometric redshifts are determined using the EAzY code and compared to {approx}2000 spectroscopic redshifts in this field. The medium-band filters provide very accurate redshifts for the (bright) subset of galaxies with spectroscopic redshifts, particularly at 0.1 < z < 1.2 and at z {approx}> 3.5. For 0.1 < z < 1.2, we find a 1{sigma} scatter in {Delta}z/(1 + z) of 0.007, similar to results obtained with a similar filter set in the COSMOS field. As a demonstration of the data quality, we show that the red sequence and blue cloud can be cleanly identified in rest-frame color-magnitude diagrams at 0.1 < z < 1.2. We find that {approx}20% of the red sequence galaxies show evidence of dust emission at longer rest-frame wavelengths. The reduced images, photometric catalog, and photometric redshifts are provided through the public MUSYC Web site.

  9. Experimental determination of band offsets of NiO-based thin film heterojunctions

    SciTech Connect (OSTI)

    Kawade, Daisuke; Sugiyama, Mutsumi, E-mail: mutsumi@rs.noda.tus.ac.jp [Faculty of Science and Technology/Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda 278-8510 (Japan); Chichibu, Shigefusa F. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba, Sendai 980–8577 (Japan)

    2014-10-28T23:59:59.000Z

    The energy band diagrams of NiO-based solar cell structures that use various n-type oxide semiconductors such as ZnO, Mg{sub 0.3}Zn{sub 0.7}O, Zn{sub 0.5}Sn{sub 0.5}O, In{sub 2}O{sub 3}:Sn (ITO), SnO{sub 2}, and TiO{sub 2} were evaluated by photoelectron yield spectroscopy. The valence band discontinuities were estimated to be 1.6?eV for ZnO/NiO and Mg{sub 0.3}Zn{sub 0.7}O/NiO, 1.7?eV for Zn{sub 0.5}Sn{sub 0.5}O/NiO and ITO/NiO, and 1.8?eV for SnO{sub 2}/NiO and TiO{sub 2}/NiO heterojunctions. By using the valence band discontinuity values and corresponding energy bandgaps of the layers, energy band diagrams were developed. Judging from the band diagram, an appropriate solar cell consisting of p-type NiO and n-type ZnO layers was deposited on ITO, and a slight but noticeable photovoltaic effect was obtained with an open circuit voltage (V{sub oc}) of 0.96?V, short circuit current density (J{sub sc}) of 2.2??A/cm{sup 2}, and fill factor of 0.44.

  10. Near infrared 3~~ overtone band of Hl Brian F. Ventrudo and Daniel T. Cassidy

    E-Print Network [OSTI]

    Oka, Takeshi

    Near infrared 3~~ overtone band of Hl Brian F. Ventrudo and Daniel T. Cassidy Department infrared spectrum of the 3vz overtone band (v2=3+0) of H; has been observed at 1.4 pm. The spectrum transitions. Short-external-cavity InCaAsP diodes were used as tunable near infrared radiation sources

  11. The Huggins band of ozone: Unambiguous electronic and vibrational Zheng-Wang Qu, Hui Zhu, Motomichi Tashiro, and Reinhard Schinkea)

    E-Print Network [OSTI]

    Farantos, Stavros C.

    The Huggins band of ozone: Unambiguous electronic and vibrational assignment Zheng-Wang Qu, Hui Zhu 12 February 2004; accepted 2 March 2004 The Huggins band of ozone is investigated by means of exact.1063/1.1711589 Because of the importance of ozone for the shielding of harmful UV light, its photophysics has been

  12. The Huggins band of ozone: A theoretical analysis Zheng-Wang Qu, Hui Zhu, Sergy Yu. Grebenshchikov, and Reinhard Schinkea)

    E-Print Network [OSTI]

    Farantos, Stavros C.

    The Huggins band of ozone: A theoretical analysis Zheng-Wang Qu, Hui Zhu, Sergy Yu. Grebenshchikov; accepted 16 September 2004 The Huggins band of ozone is investigated by means of dynamics calculations American Institute of Physics. DOI: 10.1063/1.1814098 I. INTRODUCTION Because of the importance of ozone

  13. Electronic band structure of wurtzite GaN under biaxial strain in the M plane investigated with photoreflectance spectroscopy

    E-Print Network [OSTI]

    Ghosh, Sandip

    Electronic band structure of wurtzite GaN under biaxial strain in the M plane investigated; published 7 January 2002 We investigate the modification of the electronic band structure in wurtzite Ga.40.Fy I. INTRODUCTION The wurtzite WZ structure of III-V nitrides leads to electrostatic fields due

  14. Electronic band-structure engineering of GaAs/AlxGa1(xAs quantum well superlattices with substructures

    E-Print Network [OSTI]

    Cao, Wenwu

    Electronic band-structure engineering of GaAs/AlxGa1(xAs quantum well superlattices investigation on the band structures of electrons in both infinite and finite semiconductor quantum well of these two materials, narrower passbands and/or broad stopbands can be obtained for electrons with energy

  15. Fermi level stabilization and band edge energies in Cd{sub x}Zn{sub 1?x}O alloys

    SciTech Connect (OSTI)

    Detert, Douglas M.; Tom, Kyle B.; Dubon, Oscar D. [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Materials Science and Engineering, University of California, Berkeley, California 94720 (United States); Battaglia, Corsin; Javey, Ali [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California 94720 (United States); Denlinger, Jonathan D. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Lim, Sunnie H. N. [Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Anders, André [Accelerator and Fusion Research Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Yu, Kin M.; Walukiewicz, Wladek [Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

    2014-06-21T23:59:59.000Z

    We have measured the band edge energies of Cd{sub x}Zn{sub 1?x}O thin films as a function of composition by three independent techniques: we determine the Fermi level stabilization energy by pinning the Fermi level with ion irradiation, measure the binding energy of valence band states and core levels by X-ray photoelectron spectroscopy, and probe shifts in the conduction band and valence band density of states using soft X-ray absorption and emission spectroscopy, respectively. The three techniques find consensus in explaining the origin of compositional trends in the optical-bandgap narrowing upon Cd incorporation in wurtzite ZnO and widening upon Zn incorporation in rocksalt CdO. The conduction band minimum is found to be stationary for both wurtzite and rocksalt alloys, and a significant upward rise of the valence band maximum accounts for the majority of these observed bandgap changes. Given these band alignments, alloy disorder scattering is found to play a negligible role in decreasing the electron mobility for all alloys. These band alignment details, combined with the unique optical and electrical properties of the two phase regimes, make CdZnO alloys attractive candidates for photoelectrochemical water splitting applications.

  16. Effects of surface termination on the band gap of ultrabright Si29 nanoparticles: Experiments and computational models

    E-Print Network [OSTI]

    Braun, Paul

    Effects of surface termination on the band gap of ultrabright Si29 nanoparticles: Experiments constituting a H-terminated reconstructed Si surface was recently proposed as a structural prototype termination with a N linkage in butylamine and O linkage in pentane . The emission band for N-termination

  17. A Tunable X-Band SiGe HBT Single Stage Cascode Mustafa DOGAN1,2

    E-Print Network [OSTI]

    Yanikoglu, Berrin

    A Tunable X-Band SiGe HBT Single Stage Cascode LNA Mustafa DOGAN1,2 1 TUBITAK ­ UEKAE, ETTM ­ EMC-band silicon-germanium (SiGe) single stage cascode tunable low-noise amplifier (LNA) for active phased array transmit/receive modules. LNA is implemented by using IHP SiGe heterojunction bipolar transistors (HBTs) 0

  18. Band Offsets of InGaP/GaAs Heterojunctions by Scanning Tunneling Spectroscopy Y. Dong and R. M. Feenstra

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Band Offsets of InGaP/GaAs Heterojunctions by Scanning Tunneling Spectroscopy Y. Dong and R. M Abstract Scanning tunneling microscopy and spectroscopy are used to study InGaP/GaAs heterojunctions computation of the tunnel current. Curve fitting of theory to experiment is performed. Using an InGaP band gap

  19. Roles of nanoclusters in shear banding and plastic deformation of bulk metallic glasses

    SciTech Connect (OSTI)

    Nieh, T.G.

    2012-07-31T23:59:59.000Z

    During the course of this research we published 33 papers in various physics/material journals. We select four representing papers in this report and their results are summarized as follows. I. To study shear banding process, it is pertinent to know the intrinsic shear strain rate within a propagating shear band. To this aim, we used nanoindentation technique to probe the mechanical response of a Au49Ag5.5Pd2.3Cu26.9Si16.3 bulk metallic glass in locality and found notable pop-in events associated with shear band emission. Using a free volume model and under the situation when temperature and stress/hardness are fixed result in an equation, which predicts that hardness serration caused by pop-in decreases exponentially with the strain rate. Our data are in good agreement with the prediction. The result also predicts that, when strain rate is higher than a critical strain rate of 1700 s^-1, there will be no hardness serration, thereby no pop-in. In other words, multiple shear bandings will take place and material will flow homogeneously. The critical strain rate of 1700 s^-1 can be treated as the intrinsic strain rate within a shear band. We subsequently carried out a simulation study and showed that, if the imposed strain rate was over , the shear band spacing would become so small that the entire sample would virtually behave like one major shear band. Using the datum strain rate =1700 s^-1 and based on a shear band nucleation model proposed by us, the size of a shear-band nucleus in Au-BMG was estimated to be 3 ���� 10^6 atoms, or a sphere of ~30 nm in diameter. II. Inspired by the peculiar result published in a Science article �¢����Super Plastic Bulk Metallic Glasses at Room Temperature�¢���, we synthesized the Zr-based bulk metallic glass with a composition identical to that in the paper (Zr64.13Cu15.75Ni10.12Al10) and, subsequently, tested in compression at the same slow strain rate (~10^-4 s^-1). We found that the dominant deformation mode is always single shear. The stress-strain curve exhibited serrated pattern in the plastic region, which conventionally has been attributed to individual shear band propagation. The scanning electron micrographs taken from the deformed sample surface revealed regularly spaced striations. Analysis indicates that the observed stress-strain serrations are intimately related to the striations on the shear surface, suggesting the serrations were actually caused slip-and-stick shear along the principal shear plane. We further use video camera to conduct in situ compression experiments to unambiguously confirm the one-to-one temporal and spatial correspondence between the intermittent sliding and flow serration. This preferential shear band formation along the principal shear plane is, in fact, a natural consequence of Mode II crack, independent of strain softening or hardening, usually claimed in the literature. III. Flow serration in compression of metallic glasses is caused by the formation and propagation of localized shear bands. These shear bands propagate at an extremely high speed, so high that a load cell and load frame were unable to capture the details of the dynamic event. To subdue this problem, we conducted uniaxial compression on Zr64.13Cu15.75Ni10.12Al10 bulk metallic glass using a high-speed camera to capture the sample image and also high-sensitivity strain gauges attached to the test samples to directly measure the strain. The displacement-time curves obtained from the test and a magnified version of the displacement burst reveals clearly a three-step (acceleration, steady-state, and deceleration) process during shear band propagation. The fastest propagating speed occurring at the steady state is calculated as 8����10^2 ���µm/s. This speed is about 1,000 times faster than the crosshead speed. This explains the gradual disappearance of flow serration at higher strain rates previously reported during compression of

  20. InGaAs tunnel diodes for the calibration of semi-classical and quantum mechanical band-to-band tunneling models

    SciTech Connect (OSTI)

    Smets, Quentin; Verreck, Devin; Vandervorst, Wilfried; Groeseneken, Guido; Heyns, Marc M. [Imec, Kapeldreef 75, 3001 Heverlee (Belgium); KULeuven, 3001 Leuven (Belgium); Verhulst, Anne S.; Rooyackers, Rita; Merckling, Clément; Simoen, Eddy; Collaert, Nadine; Thean, Voon Y. [Imec, Kapeldreef 75, 3001 Heverlee (Belgium); Van De Put, Maarten; Sorée, Bart [Imec, Kapeldreef 75, 3001 Heverlee (Belgium); Universiteit Antwerpen, 2020 Antwerpen (Belgium)

    2014-05-14T23:59:59.000Z

    Promising predictions are made for III-V tunnel-field-effect transistor (FET), but there is still uncertainty on the parameters used in the band-to-band tunneling models. Therefore, two simulators are calibrated in this paper; the first one uses a semi-classical tunneling model based on Kane's formalism, and the second one is a quantum mechanical simulator implemented with an envelope function formalism. The calibration is done for In{sub 0.53}Ga{sub 0.47}As using several p+/intrinsic/n+ diodes with different intrinsic region thicknesses. The dopant profile is determined by SIMS and capacitance-voltage measurements. Error bars are used based on statistical and systematic uncertainties in the measurement techniques. The obtained parameters are in close agreement with theoretically predicted values and validate the semi-classical and quantum mechanical models. Finally, the models are applied to predict the input characteristics of In{sub 0.53}Ga{sub 0.47}As n- and p-lineTFET, with the n-lineTFET showing competitive performance compared to MOSFET.

  1. $^{16}$O + $^{16}$O molecular structures of positive- and negative-parity superdeformed bands in $^{34}$S

    E-Print Network [OSTI]

    Yasutaka Taniguchi

    2014-08-09T23:59:59.000Z

    The structures of excited states in $^{34}$S are investigated using the antisymmetrized molecular dynamics and generator coordinate method (GCM). The GCM basis wave functions are calculated via energy variation with a constraint on the quadrupole deformation parameter $\\beta$. By applying the GCM after parity and angular momentum projections, the coexistence of two positive- and one negative-parity superdeformed (SD) bands are predicted, and low-lying states and other deformed bands are obtained. The SD bands have structures of $^{16}$O + $^{16}$O + two valence neutrons in molecular orbitals around the two $^{16}$O cores in a cluster picture. The configurations of the two valence neutrons are $\\delta^2$ and $\\pi^2$ for the positive-parity SD bands and $\\pi^1\\delta^1$ for the negative-parity SD band. The structural changes of the yrast states are also discussed.

  2. Tunability over three frequency bands induced by mode transition in relativistic backward wave oscillator with strong end reflections

    SciTech Connect (OSTI)

    Wu, Ping; Deng, Yuqun [Department of Engineering Physics, Tsinghua University, Beijing 100084 (China); Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Fan, Juping; Teng, Yan; Shi, Yanchao; Sun, Jun [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China)

    2014-10-15T23:59:59.000Z

    This paper presents an efficient approach to realizing the frequency tunability of a relativistic backward wave oscillator (RBWO) over three frequency bands by mode transition without changing the slow wave structure (SWS). It is figured out that the transition of the operation mode in the RBWO can be efficiently achieved by using the strong end reflection of the SWS. This mode transition results in the tunability of the RBWO over three frequency bands at high power and high efficiency without changing the SWS. In numerical simulation, the output frequency of the RBWO can jump over 7.9?GHz in C-band, 9.9?GHz in X-band, and 12.4?GHz in Ku-band with output power exceeding 3.0?GW and conversion efficiency higher than 35% by just reasonably transforming the structures of the front and post resonant reflectors which provide the strong end reflection for the SWS.

  3. Heterojunction band offsets and dipole formation at BaTiO{sub 3}/SrTiO{sub 3} interfaces

    SciTech Connect (OSTI)

    Balaz, Snjezana [Department of Physics and Astronomy, Youngstown State University, One University Plaza, Youngstown, Ohio 44555 (United States)] [Department of Physics and Astronomy, Youngstown State University, One University Plaza, Youngstown, Ohio 44555 (United States); Zeng, Zhaoquan [Department of Electrical and Computer Engineering, The Ohio State University, 205 Dreese Lab, 2015 Neil Ave., Columbus, Ohio 43210 (United States)] [Department of Electrical and Computer Engineering, The Ohio State University, 205 Dreese Lab, 2015 Neil Ave., Columbus, Ohio 43210 (United States); Brillson, Leonard J. [Department of Electrical and Computer Engineering, The Ohio State University, 205 Dreese Lab, 2015 Neil Ave., Columbus, Ohio 43210 (United States) [Department of Electrical and Computer Engineering, The Ohio State University, 205 Dreese Lab, 2015 Neil Ave., Columbus, Ohio 43210 (United States); Department of Physics, The Ohio State University, 191 West Woodruff, Columbus, Ohio 43210 (United States)

    2013-11-14T23:59:59.000Z

    We used a complement of photoemission and cathodoluminescence techniques to measure formation of the BaTiO{sub 3} (BTO) on SrTiO{sub 3} (STO) heterojunction band offset grown monolayer by monolayer by molecular beam epitaxy. X-ray photoemission spectroscopy (XPS) provided core level and valence band edge energies to monitor the valence band offset in-situ as the first few crystalline BTO monolayers formed on the STO substrate. Ultraviolet photoemission spectroscopy (UPS) measured Fermi level positions within the band gap, work functions, and ionization potentials of the growing BTO film. Depth-resolved cathodoluminescence spectroscopy measured energies and densities of interface states at the buried heterojunction. Kraut-based XPS heterojunction band offsets provided evidence for STO/BTO heterojunction linearity, i.e., commutativity and transitivity. In contrast, UPS and XPS revealed a large dipole associated either with local charge transfer or strain-induced polarization within the BTO epilayer.

  4. Band alignment between GaN and ZrO{sub 2} formed by atomic layer deposition

    SciTech Connect (OSTI)

    Ye, Gang; Wang, Hong, E-mail: ewanghong@ntu.edu.sg; Arulkumaran, Subramaniam; Ng, Geok Ing; Li, Yang; Ang, Kian Siong [Novitas, Nanoelectronics Center of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798 (Singapore); Liu, Zhi Hong [Singapore-MIT Alliance for Research and Technology, 1 CREATE Way, Singapore 138602 (Singapore)

    2014-07-14T23:59:59.000Z

    The band alignment between Ga-face GaN and atomic-layer-deposited ZrO{sub 2} was investigated using X-ray photoelectron spectroscopy (XPS). The dependence of Ga 3d and Zr 3d core-level positions on the take-off angles indicated upward band bending at GaN surface and potential gradient in ZrO{sub 2} layer. Based on angle-resolved XPS measurements combined with numerical calculations, valence band discontinuity ?E{sub V} of 1?±?0.2?eV and conduction band discontinuity ?E{sub C} of 1.2?±?0.2?eV at ZrO{sub 2}/GaN interface were determined by taking GaN surface band bending and potential gradient in ZrO{sub 2} layer into account.

  5. Multi-bands photoconductive response in AlGaN/GaN multiple quantum wells

    SciTech Connect (OSTI)

    Chen, G.; Rong, X.; Xu, F. J.; Tang, N. [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Wang, X. Q., E-mail: wangshi@pku.edu.cn; Shen, B., E-mail: bshen@pku.edu.cn [State Key Laboratory of Artificial Microstructure and Mesoscopic Physics, School of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Fu, K.; Zhang, B. S. [Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Ruoshui Road 398, 215123 Suzhou (China); Hashimoto, H.; Yoshikawa, A. [Center for SMART Green Innovation Research, Chiba University, 1-33 Yayoi-cho, Inage-ku, Chiba 263-8522 (Japan); Ge, W. K. [Department of Physics, Tsinghua University, Beijing 100871 (China)

    2014-04-28T23:59:59.000Z

    Based on the optical transitions among the quantum-confined electronic states in the conduction band, we have fabricated multi-bands AlGaN/GaN quantum well infrared photodetectors. Crack-free AlGaN/GaN multiple quantum wells (MQWs) with atomically sharp interfaces have been achieved by inserting an AlN interlayer, which releases most of the tensile strain in the MQWs grown on the GaN underlayer. With significant reduction of dark current by using thick AlGaN barriers, photoconductive responses are demonstrated due to intersubband transition in multiple regions with center wavelengths of 1.3, 2.3, and 4??m, which shows potential applications on near infrared detection.

  6. High power operation of an X-band coaxial multi-beam relativistic klystron amplifier

    SciTech Connect (OSTI)

    Liu, Zhenbang; Huang, Hua; Jin, Xiao; Zhao, Yucong; He, Hu; Lei, Lurong; Chen, Zhaofu [Science and Technology on High Power Microwave Laboratory, Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900 (China)] [Science and Technology on High Power Microwave Laboratory, Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900 (China)

    2013-11-15T23:59:59.000Z

    An X-band coaxial multi-beam relativistic klystron amplifier is designed in order to increase output microwave power and operating frequency of the amplifier tube. The experiment is performed on a Tesla-type accelerator. The amplifier is driven by an electron beam of 2.8 kA at 720 kV, and a microwave power of 30 kW and frequency of 9.384 GHz is injected into an input cavity by means of an external source, then a microwave power of over 800 MW is extracted, the amplifier gain is about 44 dB, and conversion efficiency is 40%. The experiment proves that output power of nearly GWs can be generated with the X-band coaxial multi-beam relativistic klystron amplifier driven by a kW-level input power.

  7. Competition and Coexistence of Order Parameters in Holographic Multi-Band Superconductors

    E-Print Network [OSTI]

    Cai, Rong-Gen; Li, Li-Fang; Wang, Yong-Qiang

    2013-01-01T23:59:59.000Z

    We construct a holographic multi-band superconductor model with each complex scalar field in the bulk minimally coupled to a same gauge field. Taking into account the back reaction of matter fields on the background geometry and focusing on the two band case with two scalar order parameters, we find that depending on the strength of the back reaction and the charge ratio of the two bulk scalars, five different superconducting phases exist, and three of five phases exhibit some region where both orders coexist and are thermodynamically favored. The other two superconducting phases have only one scalar order. The model exhibits rich phase structure and we construct the full diagram for the five superconducting phases. Our analysis indicates that the equivalent attractive interaction mediated by gravity between the two order parameters tends to make the coexistence of two orders much more easy rather than more difficult.

  8. Triaxial shape coexistence and new aligned band in {sup 178}Os

    SciTech Connect (OSTI)

    Kumar, Rajesh; Govil, I. M. [Department of Physics, Panjab University, Chandigarh-160014 (India); Dhal, A.; Chaturvedi, L. [Department of Physics, Banaras Hindu University, Varanasi-220115, Uttar Pradesh (India); Praharaj, C. R. [Institute of Physics, Bhubaneshwar-751005 (India); Rath, A. K. [Department of Physics, Sambalpur University, Jyoti Vihar, Burla, Sambalpur-768019, Orissa (India); Kumar, G. Kiran [Department of Physics, Maharaja Sayajirao University, Vadodara, Baroda 390002 (India); Basu, S. K. [Variable Energy Cyclotron Center, Bidhan Nagar, Calcutta-700064 (India); Chakraborty, A.; Krishichayan; Mukhopadhyay, S.; Pattabiraman, N. S.; Ghugre, S. S.; Sinha, A. K. [UGC-DAE Consortium for Scientific Research, Calcutta Centre, Sector III LB-8, Bidhan Nagar, Kolkata-700098 (India)

    2009-11-15T23:59:59.000Z

    High spin states in {sup 178}Os were studied by means of {sup 165}Ho({sup 20}Ne,p6n){sup 178}Os fusion evaporation reaction at a beam energy of 150 MeV, using a clover detector array. Several new transitions belonging to {sup 178}Os were placed in a level scheme and a new aligned rotational band was observed in addition to earlier known bands. Spin-parity assignments for most of the proposed levels were made using the deduced directional correlation orientation and polarization measurements for the de-exciting transitions. Experimental results are compared with the projected angular momentum deformed Hartree-Fock model calculations and cranked Woods-Saxon model calculations. This nucleus is predicted to be prolate deformed in the ground state but the {gamma}-softness at higher excitation is revealed by the cranked Woods-Saxon model and the geometrical asymmetric model calculations.

  9. Band gap tuning in transition metal oxides by site-specific substitution

    DOE Patents [OSTI]

    Lee, Ho Nyung; Chisholm, Jr., Matthew F; Jellison, Jr., Gerald Earle; Singh, David J; Choi, Woo Seok

    2013-12-24T23:59:59.000Z

    A transition metal oxide insulator composition having a tuned band gap includes a transition metal oxide having a perovskite or a perovskite-like crystalline structure. The transition metal oxide includes at least one first element selected form the group of Bi, Ca, Ba, Sr, Li, Na, Mg, K, Pb, and Pr; and at least one second element selected from the group of Ti, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zr, Nb, Mo, Ru, Rh, Hf, Ta, W, Re, Os, Ir, and Pt. At least one correlated insulator is integrated into the crystalline structure, including REMO.sub.3, wherein RE is at least one Rare Earth element, and wherein M is at least one element selected from the group of Co, V, Cr, Ni, Mn, and Fe. The composition is characterized by a band gap of less of 4.5 eV.

  10. Converter-Modulator Design and Operations for the ILC L-band Test Stand

    SciTech Connect (OSTI)

    Reass, William A.; /Los Alamos; Burkhart, C.; Adolphsen, Chris E.; Beukers, T.; Cassel, R.; de Lira, A.; Papas, C.; Nguyen, M.; Went, R.; /SLAC; Anderson, David E.; /Oak

    2007-09-10T23:59:59.000Z

    To facilitate a rapid response to the International Linear Collider (ILC) L-band development program at SLAC, a spare converter-modulator was shipped from LANL. This modulator was to be a spare for the spallation neutron source (SNS) accelerator at ORNL. The ILC application requires a 33% higher peak output power (15 MW) and output current (120 Amp). This presents significant design challenges to modify the existing hardware and yet maintain switching parameters and thermal cycling within the semiconductor component ratings. To minimize IGBT commutation and free-wheeling diode currents, a different set of optimizations, as compared to the SNS design, were used to tune the resonant switching networks. Additional complexities arose as nanocrystalline cores with different performance characteristics (as compared to SNS), were used to fabricate the resonant 'boost' transformers. This paper will describe the electrical design, modeling efforts, and resulting electrical performance as implemented for the ILC L-band test stand.

  11. H-band thermal emission from the 0.79-day period planet WASP-19b

    E-Print Network [OSTI]

    Anderson, D R; Maxted, P F L; Barman, T S; Cameron, A Collier; Hellier, C; Queloz, D; Smalley, B; Triaud, A H M J

    2010-01-01T23:59:59.000Z

    We present the first ground-based detection of thermal emission from an exoplanet in the H-band. Using HAWK-I on the VLT, we observed an occultation of WASP-19b by its G8V-type host star. WASP-19b is a Jupiter-mass planet with an orbital period of only 0.79 d, and thus, being highly irradiated, is expected to be hot. We measure an H-band occultation depth of (0.259 +0.046 -0.044) %. A cloud-free model of the planet's atmosphere, with no redistribution of energy from day-side to night-side, under-predicts the planet/star flux density ratio by a factor of two. As the stellar parameters, and thus the level of planetary irradiation, are well-constrained by measurement, it is likely that our model of the planet's atmosphere is too simple.

  12. Energy band modulation of graphane by hydrogen-vacancy chains: A first-principles study

    SciTech Connect (OSTI)

    Wu, Bi-Ru [Department of Natural science, Center for General Education, Chang Gung University, Kueishan 333, Taiwan, ROC (China); Yang, Chih-Kai, E-mail: ckyang@nccu.edu.tw [Graduate Institute of Applied Physics, National Chengchi University, Taipei 11605, Taiwan, ROC (China)

    2014-08-15T23:59:59.000Z

    We investigated a variety of configurations of hydrogen-vacancy chains in graphane by first-principles density functional calculation. We found that graphane with two zigzag H-vacancy chains segregated by one or more H chain is generally a nonmagnetic conductor or has a negligible band gap. However, the same structure is turned into a semiconductor and generates a magnetic moment if either one or both of the vacancy chains are blocked by isolated H atoms. If H-vacancy chains are continuously distributed, the structure is similar to a zigzag graphene nanoribbon embedded in graphane. It was also found that the embedded zigzag graphene nanoribbon is antiferromagnetic, and isolated H atoms left in the 2-chain nanoribbon can tune the band gap and generate net magnetic moments. Similar effects are also obtained if bare carbon atoms are present outside the nanoribbon. These results are useful for designing graphene-based nanoelectronic circuits.

  13. The effect of spin-orbit coupling in band structure of few-layer graphene

    SciTech Connect (OSTI)

    Sahdan, Muhammad Fauzi, E-mail: sahdan89@yahoo.co.id; Darma, Yudi, E-mail: sahdan89@yahoo.co.id [Department of Physics, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung 40132 (Indonesia)

    2014-03-24T23:59:59.000Z

    Topological insulators are electronic materials that have a bulk band gap like an ordinary insulator but have protected conducting states on their edge or surface. This can be happened due to spin-orbit coupling and time-reversal symmetry. Moreover, the edge current flows through their edge or surface depends on its spin orientation and also it is robust against non-magnetic impurities. Therefore, topological insulators are predicted to be useful ranging from spintronics to quantum computation. Graphene was first predicted to be the precursor of topological insulator by Kane-Mele. They developed a Hamiltonian model to describe the gap opening in graphene. In this work, we investigate the band structure of few-layer graphene by using this model with analytical approach. The results of our calculations show that the gap opening occurs at K and K’ point, not only in single layer, but also in bilayer and trilayer graphene.

  14. Support pedestals for interconnecting a cover and nozzle band wall in a gas turbine nozzle segment

    DOE Patents [OSTI]

    Yu, Yufeng Phillip (Simpsonville, SC); Itzel, Gary Michael (Simpsonville, SC); Webbon, Waylon Willard (Greenville, SC); Bagepalli, Radhakrishna (Schenectady, NY); Burdgick, Steven Sebastian (Schenectady, NY); Kellock, Iain Robertson (Simpsonville, SC)

    2002-01-01T23:59:59.000Z

    A gas turbine nozzle segment has outer and inner band portions. Each band portion includes a nozzle wall, a cover and an impingement plate between the cover and nozzle wall defining two cavities on opposite sides of the impingement plate. Cooling steam is supplied to one cavity for flow through the apertures of the impingement plate to cool the nozzle wall. Structural pedestals interconnect the cover and nozzle wall and pass through holes in the impingement plate to reduce localized stress otherwise resulting from a difference in pressure within the chamber of the nozzle segment and the hot gas path and the fixed turbine casing surrounding the nozzle stage. The pedestals may be cast or welded to the cover and nozzle wall.

  15. Frequency Conversion: Side-band cooling, state-swapping, and coherent control of mechanical resonators

    E-Print Network [OSTI]

    Kurt Jacobs; Hendra I. Nurdin; Frederick W. Strauch; Matthew James

    2010-07-03T23:59:59.000Z

    Sideband cooling is a technique that potentially allows mechanical resonators to be prepared in their ground states, important for future applications in quantum technologies. Tian has recently shown that side-band cooling can be implemented by modulating the coupling between a nano-resonator and a superconducting oscillator, a process of frequency conversion [L. Tian, PRB 79, 193407 (2009)]. While side-band cooling is usually treated in the steady-state regime, the effective resonant coupling will also generate near perfect state-swapping from the superconductor to the mechanical resonator. We perform numerical simulations of this system, examining the ground-state cooling achieved by the state-swapping. Further, we show that the superconducting oscillator can be used to control the amplitude and phase of the resonator, while simultaneously cooling it, and thus act as a coherent "quantum feedback controller".

  16. Indirect-direct band gap transition through electric tuning in bilayer MoS{sub 2}

    SciTech Connect (OSTI)

    Zhang, Z. Y.; Si, M. S., E-mail: sims@lzu.edu.cn; Wang, Y. H.; Gao, X. P. [Key laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou 730 000 (China)] [Key laboratory for Magnetism and Magnetic Materials of the Ministry of Education, School of Physical Science and Technology, Lanzhou University, Lanzhou 730 000 (China); Sung, Dongchul; Hong, Suklyun [Graphene Research Institute, Sejong University, Seoul 143 747 (Korea, Republic of)] [Graphene Research Institute, Sejong University, Seoul 143 747 (Korea, Republic of); He, Junjie [Department of Physics, Xiangtan University, Hunan 411 105 (China)] [Department of Physics, Xiangtan University, Hunan 411 105 (China)

    2014-05-07T23:59:59.000Z

    We investigate the electronic properties of bilayer MoS{sub 2} exposed to an external electric field by using first-principles calculations. It is found that a larger interlayer distance, referring to that by standard density functional theory (DFT) with respect to that by DFT with empirical dispersion corrections, makes indirect-direct band gap transition possible by electric control. We show that external electric field effectively manipulates the valence band contrast between the K- and ?-valleys by forming built-in electric dipole fields, which realizes an indirect-direct transition before a semiconductor-metal transition happens. Our results provide a novel efficient access to tune the electronic properties of two-dimensional layered materials.

  17. High-frequency homogenization of zero frequency stop band photonic and phononic crystals

    E-Print Network [OSTI]

    Antonakakis, Tryfon; Guenneau, Sebastien

    2013-01-01T23:59:59.000Z

    We present an accurate methodology for representing the physics of waves, for periodic structures, through effective properties for a replacement bulk medium: This is valid even for media with zero frequency stop-bands and where high frequency phenomena dominate. Since the work of Lord Rayleigh in 1892, low frequency (or quasi-static) behaviour has been neatly encapsulated in effective anisotropic media. However such classical homogenization theories break down in the high-frequency or stop band regime. Higher frequency phenomena are of significant importance in photonics (transverse magnetic waves propagating in infinite conducting parallel fibers), phononics (anti-plane shear waves propagating in isotropic elastic materials with inclusions), and platonics (flexural waves propagating in thin-elastic plates with holes). Fortunately, the recently proposed high-frequency homogenization (HFH) theory is only constrained by the knowledge of standing waves in order to asymptotically reconstruct dispersion curves an...

  18. Narrow band wavelength selective filter using grating assisted single ring resonator

    SciTech Connect (OSTI)

    Prabhathan, P., E-mail: PPrabhathan@ntu.edu.sg; Murukeshan, V. M. [Centre for Optical and Laser Engineering (COLE), School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore)

    2014-09-15T23:59:59.000Z

    This paper illustrates a filter configuration which uses a single ring resonator of larger radius connected to a grating resonator at its drop port to achieve single wavelength selectivity and switching property with spectral features suitable for on-chip wavelength selection applications. The proposed configuration is expected to find applications in silicon photonics devices such as, on-chip external cavity lasers and multi analytic label-free biosensors. The grating resonator has been designed for a high Q-factor, high transmittivity, and minimum loss so that the wavelength selectivity of the device is improved. The proof-of-concept device has been demonstrated on a Silicon-on-Insulator (SOI) platform through electron beam lithography and Reactive Ion Etching (RIE) process. The transmission spectrum shows narrow band single wavelength selection and switching property with a high Free Spectral Range (FSR) ?60 nm and side band rejection ratio >15 dB.

  19. Single Bunch Wakefields in the CERN-PSI-ELETTRA X-band Linear Accelerator

    E-Print Network [OSTI]

    El-Ashmawy, Mostafa; Dehler, Micha; Raguin, Jean-Yves; Riddone, Germana; Zennaro, Riccardo

    2010-01-01T23:59:59.000Z

    FERMI@ELETTRA and PSI-XFEL are 4th Generation Light Sources that require high quality electron beam at the entrance of the undulator chains. In this context, a specially developed X-band structure with integrated alignment monitors will be used to mitigate the nonlinearities in the longitudinal phase space due to the second order RF time curvature and the second order momentum compaction term of chicane compressor. The knowledge of the transverse and longitudinal short range wakefields in the X-band structure is essential to evaluate the beam quality in terms of longitudinal energy spread and transverse kick spread. We have used the ABCI code to numerically evaluate the transverse and longitudinal wake potentials for short bunches in this structure

  20. Reflection and transmission of ocean wave spectra by a band of randomly distributed ice floes

    E-Print Network [OSTI]

    Montiel, Fabien; Bennetts, Luke

    2014-01-01T23:59:59.000Z

    A new ocean wave/sea-ice interaction model is proposed that simulates how a directional wave spectrum evolves as it travels through an arbitrary finite array of circular ice floes, where wave/ice dynamics are entirely governed by wave scattering effects. The model is applied to characterise the wave reflection and transmission properties of a strip of ice floes, such as an ice edge band. A method is devised to extract the reflected and transmitted directional wave spectra produced by the array. The method builds upon an integral mapping from polar to Cartesian coordinates of the scattered wave components. Sensitivity tests are conducted for a row of floes randomly perturbed from a regular arrangement. Results for random arrays are generated using ensemble averaging. A realistic ice edge band is then reconstructed from field experiments data. Simulations show a good qualitative agreement with the data in terms of transmitted wave energy and directional spreading. In particular, it is observed that short waves ...

  1. Band gap corrections for molecules and solids using Koopmans theorem and Wannier functions

    E-Print Network [OSTI]

    Ma, Jie

    2015-01-01T23:59:59.000Z

    We have proposed a method for correcting the Kohn-Sham eigen energies in the density functional theory (DFT) based on the Koopmans theorem using Wannier functions. The method provides a general approach applicable for molecules and solids for electronic structure calculations. It does not have any adjustable parameters and the computational cost is at the DFT level. For solids, the calculated eigen energies agree well with the experiments for not only the band gaps, but also the energies of other valence and conduction bands. For molecules, the calculated eigen energies agree well with the experimental ionization potentials and electron affinities, and show better trends than the traditional Delta-self-consistent-field (?SCF) results.

  2. A Single-band Cold Mass Support System for the MICE Superconducting Coupling Magnet

    SciTech Connect (OSTI)

    Wu, Hong; Wang, Li; Liu, X.K.; Liu, C.S.; Li, L.K.; Xu, Feng Yu; Jia, Lin X.; Green, Michael A.

    2008-04-02T23:59:59.000Z

    The cooling channel of the Muon Ionization Cooling Experiment (MICE) consists of eighteen superconducting solenoid coils, which are magnetically hooked together and contained in seven modules. The operations of a pair of MICE superconducting coupling magnets are affected directly by the other solenoid coils in the MICE channel. In order to meet the stringent requirement for the magnet center and axis azimuthal angle at 4.2 K, a self-centered tension-band cold mass support system with intermediate thermal interruption was applied for the MICE superconducting coupling magnet. The physical center of the magnet does not change as it is cooled down from 300 K to 4.2 K using this support system. This paper analyzed and calculated force loads on the coupling magnet under various operation modes of the MICE cooling channel. The performance parameters of a single-band cold mass support system were calculated also.

  3. Fabrication of Ceramic Layer-by-Layer Infrared Wavelength Photonic Band Gap Crystals

    SciTech Connect (OSTI)

    Henry Hao-Chuan Kang

    2004-12-19T23:59:59.000Z

    Photonic band gap (PBG) crystals, also known as photonic crystals, are periodic dielectric structures which form a photonic band gap that prohibit the propagation of electromagnetic (EM) waves of certain frequencies at any incident angles. Photonic crystals have several potential applications including zero-threshold semiconductor lasers, the inhibition of spontaneous emission, dielectric mirrors, and wavelength filters. If defect states are introduced in the crystals, light can be guided from one location to another or even a sharp bending of light in micron scale can be achieved. This generates the potential for optical waveguide and optical circuits, which will contribute to the improvement in the fiber-optic communications and the development of high-speed computers.

  4. Using Measurements of Fill Factor at High Irradiance to Deduce Heterobarrier Band Offsets: Preprint

    SciTech Connect (OSTI)

    Olson, J. M.; Steiner, M. A.; Kanevce, A.

    2011-07-01T23:59:59.000Z

    Using a 2D device simulation tool, we examine the high irradiance behavior of a single junction, GaAs concentrator cell as a function of the doping in the back surface confinement layer. The confinement layer is designed to be a barrier for both holes and electrons in the base of the solar cell. For a p-type base we show that the FF of the cell at high concentrations is a strong function of both the magnitude of the valence band offset and the doping level in the barrier. In short, for a given valence band offset (VBO), there is a critical barrier doping, below which the FF drops rapidly with lower doping. This behavior is confirmed experimentally for a GaInP/GaAs double heterostructure solar cell where the critical doping concentration (at 500 suns) in the back surface confinement layer is ~1e18 cm-3 for a VBO of 300 meV.

  5. Ferromagnetism and the electronic band structure in (Ga,Mn)(Bi,As) epitaxial layers

    SciTech Connect (OSTI)

    Yastrubchak, O., E-mail: yastrub@hektor.umcs.lublin.pl [Institute of Physics, Maria Curie-Sklodowska University in Lublin, Pl. M. Curie-Sk?odowskiej 1, 20-031 Lublin (Poland); Institute of Semiconductor Physics, National Academy of Sciences, 41 pr. Nauki, 03028 Kyiv (Ukraine); Sadowski, J. [MAX-IV Laboratory, Lund University, P.O. Box 118, SE-221 00 Lund (Sweden); Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Gluba, L.; ?uk, J.; Kulik, M. [Institute of Physics, Maria Curie-Sklodowska University in Lublin, Pl. M. Curie-Sk?odowskiej 1, 20-031 Lublin (Poland); Domagala, J. Z.; Andrearczyk, T.; Wosinski, T. [Institute of Physics, Polish Academy of Sciences, Al. Lotnikow 32/46, 02-668 Warsaw (Poland); Rawski, M. [Analytical Laboratory, Maria Curie-Sklodowska University in Lublin, Pl. M. Curie-Sk?odowskiej 3, 20-031 Lublin (Poland)

    2014-08-18T23:59:59.000Z

    Impact of Bi incorporation into (Ga,Mn)As layers on their electronic- and band-structures as well as their magnetic and structural properties has been studied. Homogenous (Ga,Mn)(Bi,As) layers of high structural perfection have been grown by the low-temperature molecular-beam epitaxy technique. Post-growth annealing treatment of the layers results in an improvement of their structural and magnetic properties and an increase in the hole concentration in the layers. The modulation photoreflectance spectroscopy results are consistent with the valence-band model of hole-mediated ferromagnetism in the layers. This material combines the properties of (Ga,Mn)As and Ga(Bi,As) ternary compounds and offers the possibility of tuning its electrical and magnetic properties by controlling the alloy composition.

  6. Periodic dielectric structure for production of photonic band gap and method for fabricating the same

    DOE Patents [OSTI]

    Ozbay, E.; Tuttle, G.; Michel, E.; Ho, K.M.; Biswas, R.; Chan, C.T.; Soukoulis, C.

    1995-04-11T23:59:59.000Z

    A method is disclosed for fabricating a periodic dielectric structure which exhibits a photonic band gap. Alignment holes are formed in a wafer of dielectric material having a given crystal orientation. A planar layer of elongate rods is then formed in a section of the wafer. The formation of the rods includes the step of selectively removing the dielectric material of the wafer between the rods. The formation of alignment holes and layers of elongate rods and wafers is then repeated to form a plurality of patterned wafers. A stack of patterned wafers is then formed by rotating each successive wafer with respect to the next-previous wafer, and then placing the successive wafer on the stack. This stacking results in a stack of patterned wafers having a four-layer periodicity exhibiting a photonic band gap. 42 figures.

  7. Band structures and intruder $?$$i_{13/2}$ state in $^{197}$Tl

    E-Print Network [OSTI]

    H. Pai; G. Mukherjee; S. Bhattacharya; C. Bhattacharya; S. Bhattacharyya; T. Bhattacharjee; S. Chanda; S. Rajbanshi; A. Goswami; M. R. Gohil; S. Kundu; T. K. Ghosh; K. Banerjee; T. K. Rana; R. Pandey; G. K. Prajapati; S. R. Banerjee; S. Mukhopadhyay; D. Pandit; S. Pal; J. K. Meena; P. Mukhopadhyay; A. Chawdhury

    2013-11-08T23:59:59.000Z

    The excited states in the odd-$A$ $^{197}$Tl nucleus have been studied by populating them using the $^{197}$Au($\\alpha$, 4$n$)$^{197}$Tl reaction at the beam energy of 48 MeV. The $\\gamma-\\gamma$ coincidence data were taken using a combination of clover, LEPS and single crystal HPGe detectors. Precise spin and parity assignments of the excited states have been done through the polarization and the DCO measurements. A new band structure has been identified and the evidence for a possible intruder $\\pi i_{13/2}$ state has been found for the first time. Possible configurations of the observed bands have been discussed. The total Routhian surface calculations have been performed to study the shape of $^{197}$Tl for different configurations.

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

    E-Print Network [OSTI]

    S. Naik; P. J. Callanan; B. Paul; T. Dotani

    2006-05-01T23:59:59.000Z

    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_\\alpha line at 6.4 keV of ~13 eV (for a width of 100 eV). Assuming a spherical blackbody emitting region and the distance of the source to be 10 kpc, the radius of the emitting region is found to be in the range of 14--22 km, which rules out the inner accretion disk as the soft X-ray emitting region.

  9. V-band Transmission and Reflection Grid Amplifier Packaged in Waveguide

    E-Print Network [OSTI]

    rotation. In a reflection amplifier, the back short provides tuning and a cross-polarized horn or an ortho of the drain and gate to be matched. In this work, we designed and packaged a V-band single-stage grid ampli, and off-state drain-source breakdown volt- age are 750 mS/mm, 650 mA/mm, and 7 V. TRW's baseline 75- ąm

  10. Pre-Stressed Viscoelastic Composites: Effective Incremental Moduli and Band-Gap Tuning

    SciTech Connect (OSTI)

    Parnell, William J. [School of Mathematics, Alan Turing Building, University of Manchester, Manchester, M13 9PL (United Kingdom)

    2010-09-30T23:59:59.000Z

    We study viscoelastic wave propagation along pre-stressed nonlinear elastic composite bars. In the pre-stressed state we derive explicit forms for the effective incremental storage and loss moduli with dependence on the pre-stress. We also derive a dispersion relation for the effective wavenumber in the case of arbitrary frequency, hence permitting a study of viscoelastic band-gap tuning via pre-stress.

  11. A preliminary study of the stratospheric warm band over North America

    E-Print Network [OSTI]

    Goldman, Joseph L

    1960-01-01T23:59:59.000Z

    III, DISCUSSION AND RESULTS OF CONSTANT PRESSURE ANALYSES ~ ~ 10 CHAPTER IV ~ TIME VARIATION OF STRATOSPHERIC TEMPERATURE IN THE VICIN ITY OF IBE WARN BAND i o ~ ~ ~ o o o o . o ~ ~ ~ o ~ o o ~ ~ ~ ~ RS CHAPTER V o CCSCLUSIONS AND RECOMMENDATIONS... ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 45 Q. Tine-Tenperaturs Profile& Port Barrison. . ~ . . ~ " ~ ~ ~ ~ "~ "~ . ~ 48 10 ' Tine Tenperature Prcfile& Buffalc ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 4T LIST OF TABLES I. Locations and teeperatures of the warn axis, and looations...

  12. The Moon Glistens: A New Work for Band by Joni Greene: A Conductor's Analysis

    E-Print Network [OSTI]

    Simons, Chad P.

    2014-05-31T23:59:59.000Z

    in the various ensembles within the UT band program. During the spring semester of 2001, Greene met Rafael Hernandez, a master’s candidate and a teaching assistant in the UT composition department. After submitting some short works for Hernandez’ review, she... soon began taking weekly composition lessons with him. This was Greene’s first formal training in musical composition and lead to the completion of her first piece: Wave. After meeting with some success studying with Hernandez, Greene auditioned...

  13. Electron Band Structure of MnGaN Dimiter Alexandrov1

    E-Print Network [OSTI]

    Dietz, Nikolaus

    to this orbital to be occupied. LCAO electron band structure of wurtzite MnxGa1-xN for points c1 and v15 ( = 1 of the wurtzite MnxGa1-xN are determined as well. INTRODUCTION The MnxGa1-xN semiconductor alloy is important model the MnGaN alloy on Mn content. Segregated Mn species in wurtzite GaN containing Mn

  14. A NEW MULTI-BAND RADIAL VELOCITY TECHNIQUE FOR DETECTING EXOPLANETS AROUND ACTIVE STARS

    SciTech Connect (OSTI)

    Ma Bo; Ge Jian, E-mail: boma@astro.ufl.edu, E-mail: jge@astrto.ufl.edu [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611 (United States)

    2012-05-10T23:59:59.000Z

    The radial velocity (RV) technique is one of the most efficient ways of detecting exoplanets. However, large RV jitters induced by starspots on an active star can inhibit detection of any exoplanet present or even lead to a false positive detection. This paper presents a new multi-band RV technique capable of substantially reducing starspot-induced RV jitters from stellar RV measurements to allow efficient and accurate extraction of RV signals caused by exoplanets. It takes full advantage of the correlation of RV jitters at different spectral bands and the independence of exoplanet signals at the corresponding bands. Simulations with a single-spot model and a multi-spot model have been conducted to investigate the RV jitter reduction capability of this method. The results show that this method can reduce the RV jitter amplitude by at least an order of magnitude, allowing detection of weaker exoplanet signals without significantly increasing RV observation time and cadence. This method can greatly reduce the observation time required to detect Earth-like planets around solar type stars with {approx}0.1 m s{sup -1} long term Doppler precision if spot-induced jitter is the dominant astrophysical noise source for RV measurements. This method can work efficiently for RV jitter removal if: (1) all the spots on a target star have approximately the same temperature during RV observations; (2) the RV jitter amplitude changes with wavelength, i.e., the RV jitter amplitude ratio, {alpha}, between two different spectral bands is not close to one; (3) the spot-induced RV jitter dominates the RV measurement error.

  15. Engineering of the band gap and optical properties of thin films of yttrium hydride

    SciTech Connect (OSTI)

    You, Chang Chuan; Mongstad, Trygve; Maehlen, Jan Petter; Karazhanov, Smagul, E-mail: smagulk@ife.no [Institute for Energy Technology, P.O. Box 40, NO-2027 Kjeller (Norway)

    2014-07-21T23:59:59.000Z

    Thin films of oxygen-containing yttrium hydride show photochromic effect at room temperature. In this work, we have studied structural and optical properties of the films deposited at different deposition pressures, discovering the possibility of engineering the optical band gap by variation of the oxygen content. In sum, the transparency of the films and the wavelength range of photons triggering the photochromic effect can be controlled by variation of the deposition pressure.

  16. Effect of silver incorporation in phase formation and band gap tuning of tungsten oxide thin films

    SciTech Connect (OSTI)

    Jolly Bose, R.; Kumar, R. Vinod; Sudheer, S. K.; Mahadevan Pillai, V. P. [Department of Optoelectronics, University of Kerala, Kariyavattom, Thiruvananthapuram, Kerala 695581 (India); Reddy, V. R.; Ganesan, V. [UGC - DAE Consortium for Scientific Research, Khandwa Road, Indore 452017, Madhyapradesh (India)

    2012-12-01T23:59:59.000Z

    Silver incorporated tungsten oxide thin films are prepared by RF magnetron sputtering technique. The effect of silver incorporation in micro structure evolution, phase enhancement, band gap tuning and other optical properties are investigated using techniques such as x-ray diffraction, micro-Raman spectroscopy, atomic force microscopy, scanning electron microscopy, energy dispersive x-ray spectroscopy, and UV-Visible spectroscopy. Effect of silver addition in phase formation and band gap tuning of tungsten oxide thin films are investigated. It is found that the texturing and phase formation improves with enhancement in silver content. It is also found that as the silver incorporation enhances the thickness of the films increases at the same time the strain in the film decreases. Even without annealing the desired phase can be achieved by doping with silver. A broad band centered at the wavelength 437 nm is observed in the absorption spectra of tungsten oxide films of higher silver incorporation and this can be attributed to surface plasmon resonance of silver atoms present in the tungsten oxide matrix. The transmittance of the films is decreased with increase in silver content which can be due to increase in film thickness, enhancement of scattering, and absorption of light caused by the increase of grain size, surface roughness and porosity of films and enhanced absorption due to surface plasmon resonance of silver. It is found that silver can act as the seed for the growth of tungsten oxide grains and found that the grain size increases with silver content which in turn decreases the band gap of tungsten oxide from 3.14 eV to 2.70 eV.

  17. Measurement of intensities of bands in the electronic absorption spectrum of chlorine dioxide

    E-Print Network [OSTI]

    Rapp, Thomas Louis

    1955-01-01T23:59:59.000Z

    energy levels are derived, Twelve bands in the electronic absorption spectrum of chlorine dioxide between the wavelengths 4250 R and 5250 R were photographed and measured. Of these twelve, the vibrational energy levels calculated for nine of them... Calculation of Vibrational Energy Levels . . . . , 35 Estimation of Errors . . . , . . . . . . . . . . . 38 CONCLUSIONS Conolusions ~ ~ ~ 47 B IBLI QGRAFEZ ~ ~ ~ ~ ~ ~ ~ ~ 48 ~INTRGDUGT10 Analysis of thc rotational structure of the chlorine dioxide...

  18. Band gap tunning in BN-doped graphene systems with high carrier mobility

    SciTech Connect (OSTI)

    Kaloni, T. P.; Schwingenschlögl, U., E-mail: udo.schwingenschlogl@kaust.edu.sa [KAUST, PSE Division, Thuwal 23955-6900 (Saudi Arabia); Joshi, R. P.; Adhikari, N. P. [Central Department of Physics, Tribhuvan University, Kirtipur, Kathmandu (Nepal)

    2014-02-17T23:59:59.000Z

    Using density functional theory, we present a comparative study of the electronic properties of BN-doped graphene monolayer, bilayer, trilayer, and multilayer systems. In addition, we address a superlattice of pristine and BN-doped graphene. Five doping levels between 12.5% and 75% are considered, for which we obtain band gaps from 0.02?eV to 2.43?eV. We demonstrate a low effective mass of the charge carriers.

  19. Miniaturized Multi-Band Antenna Design via Element Collocation and Inductive Feed Loading

    SciTech Connect (OSTI)

    Martin, R. P.

    2012-09-12T23:59:59.000Z

    In a FY09 SDRD project, four separate antennas were designed to receive signals of interest covering a broad range of frequencies. While the elements exceeded specifications, the array footprint is substantial. Research performed by the CU Microwave Active Antenna Group in collaboration with RSL, showed promise in realizing a reduced structure. This work will expand upon this previous research. This project will result in a prototype quad-band antenna.

  20. Population effects on the red giant clump absolute magnitude The K-band

    E-Print Network [OSTI]

    Salaris, M; Salaris, Maurizio

    2002-01-01T23:59:59.000Z

    We present a detailed analysis of the behaviour of the Red Clump K-band absolute magnitude (M(K,RC)) in simple and composite stellar populations, in light of its use as standard candle for distance determinations. The advantage of using M(K,RC), following recent empirical calibrations of its value for the solar neighbourhood, arises from its very low sensitivity to the extinction by interstellar dust. We provide data and equations which allow the determination of the K-band population correction Delta(M(K,RC)) (difference between the Red Clump brightness in the solar neighbourhood and in the population under scrutiny) for any generic stellar population. These data complement the results presented in Girardi & Salaris(2001) for the V- and I-band. We show how data from galactic open clusters consistently support our predicted Delta(M(V,RC)), Delta(M(I,RC)) and Delta(M(K,RC)) values. Multiband VIK population corrections for various galaxy systems are provided. They can be used in conjunction with the method ...

  1. FERROELECTRIC SWITCH FOR A HIGH-POWER Ka-BAND ACTIVE PULSE COMPRESSOR

    SciTech Connect (OSTI)

    Hirshfield, Jay L. [Omega-P, Inc.] [Omega-P, Inc.

    2013-12-18T23:59:59.000Z

    Results are presented for design of a high-power microwave switch for operation at 34.3 GHz, intended for use in an active RF pulse compressor. The active element in the switch is a ring of ferroelectric material, whose dielectric constant can be rapidly changed by application of a high-voltage pulse. As envisioned, two of these switches would be built into a pair of delay lines, as in SLED-II at SLAC, so as to allow 30-MW ?s-length Ka-band pulses to be compressed in time by a factor-of-9 and multiplied in amplitude to generate 200 MW peak power pulses. Such high-power pulses could be used for testing and evaluation of high-gradient mm-wave accelerator structures, for example. Evaluation of the switch design was carried out with an X-band (11.43 GHz) prototype, built to incorporate all the features required for the Ka-band version.

  2. Temperature-driven band inversion in Pb?.??Sn?.??Se: Optical and Hall-effect studies

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Anand, Naween; Gu, Genda; Buvaev, Sanal; Hebard, A. F.; Tanner, D. B.; Chen, Zhiguo; Li, Zhiqiang; Choudhary, Kamal; Sinnott, S. B.; Martin, C.

    2014-12-01T23:59:59.000Z

    Optical and Hall-effect measurements have been performed on single crystals of Pb?.??Sn?.??Se, a IV-VI mixed chalcogenide. The temperature dependent (10–300 K) reflectance was measured over 40–7000 cm?ą (5–870 meV) with an extension to 15,500 cm?ą (1.92 eV) at room temperature. The reflectance was fit to the Drude-Lorentz model using a single Drude component and several Lorentz oscillators. The optical properties at the measured temperatures were estimated via Kramers-Kronig analysis as well as by the Drude-Lorentz fit. The carriers were p-type with the carrier density determined by Hall measurements. A signature of valence intraband transition is found in the low-energy opticalmore »spectra. It is found that the valence-conduction band transition energy as well as the free carrier effective mass reach minimum values at 100 K, suggesting temperature-driven band inversion in the material. Density function theory calculation for the electronic band structure also make similar predictions.« less

  3. Ginzburg--Landau description of laminar-turbulent oblique band formation in transitional plane Couette flow

    E-Print Network [OSTI]

    Rolland, Joran

    2011-01-01T23:59:59.000Z

    Plane Couette flow, the flow between two parallel planes moving in opposite directions, is an example of wall-bounded flow experiencing a transition to turbulence with an ordered coexistence of turbulent and laminar domains in some range of Reynolds numbers [R_g,R_t]. When the aspect-ratio is sufficiently large, this coexistence occurs in the form of alternately turbulent and laminar oblique bands. As R goes up trough the upper threshold R_t, the bands disappear progressively to leave room to a uniform regime of featureless turbulence. This continuous transition is studied here by means of under-resolved numerical simulations understood as a modelling approach adapted to the long time, large aspect-ratio limit. The state of the system is quantitatively characterised using standard observables (turbulent fraction and turbulence intensity inside the bands). A pair of complex order parameters is defined for the pattern which is further analysed within a standard Ginzburg--Landau formalism. Coefficients of the mo...

  4. EXAMINING THE BROADBAND EMISSION SPECTRUM OF WASP-19b: A NEW z-BAND ECLIPSE DETECTION

    SciTech Connect (OSTI)

    Zhou, George; Bayliss, Daniel D. R. [Research School of Astronomy and Astrophysics, Australian National University, Cotter Rd, Weston Creek, ACT 2611 (Australia); Kedziora-Chudczer, Lucyna; Bailey, Jeremy, E-mail: george@mso.anu.edu.au [School of Physics, University of New South Wales, Sydney, NSW 2052 (Australia)

    2013-09-10T23:59:59.000Z

    WASP-19b is one of the most irradiated hot-Jupiters known. Its secondary eclipse is the deepest of all transiting planets and has been measured in multiple optical and infrared bands. We obtained a z-band eclipse observation with a measured depth of 0.080% {+-} 0.029%, using the 2 m Faulkes Telescope South, which is consistent with the results of previous observations. We combined our measurement of the z-band eclipse with previous observations to explore atmosphere models of WASP-19b that are consistent with its broadband spectrum. We use the VSTAR radiative transfer code to examine the effect of varying pressure-temperature profiles and C/O abundance ratios on the emission spectrum of the planet. We find that models with super-solar carbon enrichment best match the observations, which is consistent with previous model retrieval studies. We also include upper atmosphere haze as another dimension in the interpretation of exoplanet emission spectra and find that particles <0.5 {mu}m in size are unlikely to be present in WASP-19b.

  5. Photonic-band-gap properties for two-component slow light

    SciTech Connect (OSTI)

    Ruseckas, J.; Kudriasov, V.; Juzeliunas, G.; Unanyan, R. G.; Otterbach, J.; Fleischhauer, M. [Institute of Theoretical Physics and Astronomy, Vilnius University, A. Gostauto 12, Vilnius 01108 (Lithuania); Fachbereich Physik and Research Center OPTIMAS, Technische Universitaet Kaiserslautern, Kaiserslautern D-67663 (Germany)

    2011-06-15T23:59:59.000Z

    We consider two-component ''spinor'' slow light in an ensemble of atoms coherently driven by two pairs of counterpropagating control laser fields in a double tripod-type linkage scheme. We derive an equation of motion for the spinor slow light (SSL) representing an effective Dirac equation for a massive particle with the mass determined by the two-photon detuning. By changing the detuning the atomic medium acts as a photonic crystal with a controllable band gap. If the frequency of the incident probe light lies within the band gap, the light experiences reflection from the sample and can tunnel through it. For frequencies outside the band gap, the transmission and reflection probabilities oscillate with the increasing length of the sample. In both cases the reflection takes place into the complementary mode of the probe field. We investigate the influence of the finite excited state lifetime on the transmission and reflection coefficients of the probe light. We discuss possible experimental implementations of the SSL using alkali-metal atoms such as rubidium or sodium.

  6. CAN H{sub 2}CCC BE THE CARRIER OF BROAD DIFFUSE BANDS?

    SciTech Connect (OSTI)

    Krelowski, J. [Center for Astronomy, Nicholas Copernicus University, Gagarina 11, Pl-87-100 Torun (Poland); Galazutdinov, G. [Instituto de Astronomia, Universidad Catolica del Norte, Av. Angamos 0610, Antofagasta (Chile); Kolos, R., E-mail: jacek@astri.uni.torun.pl, E-mail: runizag@gmail.com, E-mail: robert.kolos@ichf.edu.pl [Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44, 01-224 Warsaw (Poland)

    2011-07-10T23:59:59.000Z

    The recent assignment of two broad diffuse interstellar bands (DIBs) near 4882 and 5450 A to the propadienylidene (l-C{sub 3}H{sub 2}) molecule is examined using a statistically meaningful sample of targets. Our spectra clearly show that the strength ratio of two broad DIBs is strongly variable, contrary to what should be observed if both features are due to l-C{sub 3}H{sub 2}, since the proposed transitions are lifetime broadened and start from the same level. Moreover, even in directions where the 4882 DIB and 5450 DIB are strong, the third expected l-C{sub 3}H{sub 2} band, in the 5165-5185 A region, is absent. Another puzzling characteristic of l-C{sub 3}H{sub 2} as the proposed carrier of both broad diffuse bands is its column density of several 10{sup 14} cm{sup -2}, inferred from the equivalent width of the 5450 DIB. This value is one order of magnitude higher than N(CH) toward the same objects and two to three orders of magnitude higher than N(H{sub 2}CCC), measured at radio frequencies in absorption, for comparable samples of the diffuse medium. We conclude that the proposed identification of broad DIBs is unjustified.

  7. Single particle spectral function in iron pnictide superconductors within two band model

    SciTech Connect (OSTI)

    Rani, Luxmi, E-mail: Luxmiphyiitr@gmail.com; Ajay, E-mail: Luxmiphyiitr@gmail.com [Department of Applied Science and Engineering, Indian Institute of Technology Roorkee, Saharanpur Campus, Saharanpur- 247001 (India)

    2014-04-24T23:59:59.000Z

    The newly discovered iron based superconductors have shown a great deal of interest in the condensed matter physics community around the world to explore the experimental and theoretical aspects of electronic properties of these materials to underline the technological potential. These materials have a layered tetragonal crystal structure and generally show small anisotropy. Based on ARPES data to understand the band structure of these systems, we present a theoretical tight binding model and numerical computation of the single particle spectral function within two orbital per site for iron pnictide superconductors. The two band tight binding model Hamiltonian containing various orbitals hopping energies, intra- and inter- band electronic correlations and Hund’s coupling energy in Fe 3d orbitals has been used. The expressions of single particle spectral function have been obtained by employing the Green’s function equation of motion approach within BCS-mean-field approximation. The spectral function is numerically computed at different k-points of Brillouin zone in extended s-wave paring symmetry. It is noticed that the behavior of electronic states is different at different k-points of Brillouin zone and highly influenced by onsite Coulomb interactions. Further, It is predicted that the presence of onsite coulomb correlation suppress the spectral weight close to Fermi level in iron pnictide systems. On the basis of numerical computation we have compared our theoretical results with recent angle resolved photoemission spectroscopic ARPES data.

  8. Temperature-driven band inversion in Pb?.??Sn?.??Se: Optical and Hall-effect studies

    SciTech Connect (OSTI)

    Anand, Naween [Univ. of Florida, Gainesville, FL (United States); Gu, Genda [Brookhaven National Lab. (BNL), Upton, NY (United States); Buvaev, Sanal [Univ. of Florida, Gainesville, FL (United States); Hebard, A. F. [Univ. of Florida, Gainesville, FL (United States); Tanner, D. B. [Univ. of Florida, Gainesville, FL (United States); Chen, Zhiguo [Florida State Univ., Tallahassee, FL (United States); Li, Zhiqiang [Florida State Univ., Tallahassee, FL (United States); Choudhary, Kamal [Univ. of Florida, Gainesville, FL (United States); Sinnott, S. B. [Univ. of Florida, Gainesville, FL (United States); Martin, C. [Ramapo College, Mahwah, NJ (United States)

    2014-12-01T23:59:59.000Z

    Optical and Hall-effect measurements have been performed on single crystals of Pb?.??Sn?.??Se, a IV-VI mixed chalcogenide. The temperature dependent (10–300 K) reflectance was measured over 40–7000 cm?ą (5–870 meV) with an extension to 15,500 cm?ą (1.92 eV) at room temperature. The reflectance was fit to the Drude-Lorentz model using a single Drude component and several Lorentz oscillators. The optical properties at the measured temperatures were estimated via Kramers-Kronig analysis as well as by the Drude-Lorentz fit. The carriers were p-type with the carrier density determined by Hall measurements. A signature of valence intraband transition is found in the low-energy optical spectra. It is found that the valence-conduction band transition energy as well as the free carrier effective mass reach minimum values at 100 K, suggesting temperature-driven band inversion in the material. Density function theory calculation for the electronic band structure also make similar predictions.

  9. Blocking a wave: Frequency band gaps in ice shelves with periodic crevasses

    E-Print Network [OSTI]

    Julian Freed-Brown; Jason M. Amundson; Douglas R. MacAyeal; Wendy W. Zhang

    2011-12-14T23:59:59.000Z

    We assess how the propagation of high-frequency elastic-flexural waves through an ice shelf is modified by the presence of spatially periodic crevasses. Analysis of the normal modes supported by the ice shelf with and without crevasses reveals that a periodic crevasse distribution qualitatively changes the mechanical response. The normal modes of an ice shelf free of crevasses are evenly distributed as a function of frequency. In contrast, the normal modes of a crevasse-ridden ice shelf are distributed unevenly. There are "band gaps", frequency ranges over which no eigenmodes exist. A model ice shelf that is 50 km in lateral extent and 300 m thick with crevasses spaced 500 m apart has a band gap from 0.2 to 0.38 Hz. This is a frequency range relevant for ocean wave/ice-shelf interactions. When the outermost edge of the crevassed ice shelf is oscillated at a frequency within the band gap, the ice shelf responds very differently from a crevasse-free ice shelf. The flexural motion of the crevassed ice shelf is confined to a small region near the outermost edge of the ice shelf and effectively "blocked" from reaching the interior.

  10. Blocking a wave: Frequency band gaps in ice shelves with periodic crevasses

    E-Print Network [OSTI]

    Freed-Brown, Julian; MacAyeal, Douglas R; Zhang, Wendy W

    2011-01-01T23:59:59.000Z

    We assess how the propagation of high-frequency elastic-flexural waves through an ice shelf is modified by the presence of spatially periodic crevasses. Analysis of the normal modes supported by the ice shelf with and without crevasses reveals that a periodic crevasse distribution qualitatively changes the mechanical response. The normal modes of an ice shelf free of crevasses are evenly distributed as a function of frequency. In contrast, the normal modes of a crevasse-ridden ice shelf are distributed unevenly. There are "band gaps", frequency ranges over which no eigenmodes exist. A model ice shelf that is 50 km in lateral extent and 300 m thick with crevasses spaced 500 m apart has a band gap from 0.2 to 0.38 Hz. This is a frequency range relevant for ocean wave/ice-shelf interactions. When the outermost edge of the crevassed ice shelf is oscillated at a frequency within the band gap, the ice shelf responds very differently from a crevasse-free ice shelf. The flexural motion of the crevassed ice shelf is c...

  11. Physical properties and band structure of reactive molecular beam epitaxy grown oxygen engineered HfO{sub 2{+-}x}

    SciTech Connect (OSTI)

    Hildebrandt, Erwin; Kurian, Jose; Alff, Lambert [Institute of Materials Science, Technische Universitaet Darmstadt, 64287 Darmstadt (Germany)

    2012-12-01T23:59:59.000Z

    We have conducted a detailed thin film growth structure of oxygen engineered monoclinic HfO{sub 2{+-}x} grown by reactive molecular beam epitaxy. The oxidation conditions induce a switching between (111) and (002) texture of hafnium oxide. The band gap of oxygen deficient hafnia decreases with increasing amount of oxygen vacancies by more than 1 eV. For high oxygen vacancy concentrations, defect bands form inside the band gap that induce optical transitions and p-type conductivity. The resistivity changes by several orders of magnitude as a function of oxidation conditions. Oxygen vacancies do not give rise to ferromagnetic behavior.

  12. Influence of GaAs surface termination on GaSb/GaAs quantum dot structure and band offsets

    SciTech Connect (OSTI)

    Zech, E. S.; Chang, A. S.; Martin, A. J.; Canniff, J. C.; Millunchick, J. M. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)] [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Lin, Y. H. [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)] [Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Goldman, R. S. [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States) [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States); Department of Physics, University of Michigan, Ann Arbor, Michigan 48109-2136 (United States)

    2013-08-19T23:59:59.000Z

    We have investigated the influence of GaAs surface termination on the nanoscale structure and band offsets of GaSb/GaAs quantum dots (QDs) grown by molecular-beam epitaxy. Transmission electron microscopy reveals both coherent and semi-coherent clusters, as well as misfit dislocations, independent of surface termination. Cross-sectional scanning tunneling microscopy and spectroscopy reveal clustered GaSb QDs with type I band offsets at the GaSb/GaAs interfaces. We discuss the relative influences of strain and QD clustering on the band offsets at GaSb/GaAs interfaces.

  13. ngatif des tubes oxygne rarfi, il s'est trouv conduit modi-fier sa conclusion prcdente et regarder la premire bande

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    précédente et à regarder la première bande (5182) comme étant due à l'azote et la bande (5592) comme étant

  14. Nonparabolicity of the conduction band of wurtzite GaN S. Syed, J. B. Heroux, Y. J. Wang, M. J. Manfra, R. J. Molnar et al.

    E-Print Network [OSTI]

    Manfra, Michael J.

    Nonparabolicity of the conduction band of wurtzite GaN S. Syed, J. B. Heroux, Y. J. Wang, M. J://apl.aip.org/about/rights_and_permissions #12;Nonparabolicity of the conduction band of wurtzite GaN S. Syeda) Department of Applied Physics of the nonparabolicity NP of the con- duction band of wurtzite GaN currently remains controver- sial. NP of a band can

  15. Estimation of suspended sedimentsEstimation of suspended sediments i MODIS 250 b di MODIS 250 b d iiusing MODIS 250 m bandsusing MODIS 250 m bands inin

    E-Print Network [OSTI]

    Gilbes, Fernando

    iiusing MODIS 250 m bandsusing MODIS 250 m bands inin Mayagüez Bay Puerto RicoMayagüez Bay Puerto Rico

  16. Projectile Lab Advanced You will shoot a projectile across the room with a rubber band and calculate how far it flies.

    E-Print Network [OSTI]

    Spakowitz, Andrew J.

    Projectile Lab ­ Advanced You will shoot a projectile across the room with a rubber band of the projectile is ___________________ g #12;Task 2 ­ Elasticity of the Rubber Band You will measure the "elastic constant" of the rubber band which will be used to shoot your projectile. This elastic constant tells you

  17. Projectile Lab student You will shoot a projectile across the room using a rubber band and calculate how far it flies.

    E-Print Network [OSTI]

    Spakowitz, Andrew J.

    Projectile Lab ­ student You will shoot a projectile across the room using a rubber band _____________ g #12;Task 2 ­ Elasticity of the Rubber Band You will measure the "elastic constant" of the rubber band which will be used to shoot your projectile. This elastic constant tells you how strong the rubber

  18. Defect assistant band alignment transition from staggered to broken gap in mixed As/Sb tunnel field effect transistor heterostructure

    E-Print Network [OSTI]

    Yener, Aylin

    .3As heterointerface. As a result, the band alignment was converted from staggered gap to broken gap-to-source voltage, VGS. As the SS of a MOSFET is governed by the transport mechanism of thermionic-emission over

  19. Effects of broad-banded higher harmonics on fatigue damage of risers due to vortex-induced vibrations

    E-Print Network [OSTI]

    Price, Rachel Elizabeth

    2011-01-01T23:59:59.000Z

    Recent works have discussed "chaotic" or "Type-II" riser motion and suggested that it is a general feature of VIV riser response. Chaotic riser response contains broad-banded harmonics and a combination of standing and ...

  20. Conduction band discontinuity and electron confinement at the Si[subscript x]Ge[subscript 1?x]/Ge interface

    E-Print Network [OSTI]

    Mazzeo, G.

    Germanium rich heterostructures can constitute a valid alternative to Silicon for the confinement of single electron spins. The conduction band discontinuity in SiGe/Ge heterostructures grown on pure germanium substrate ...

  1. Absolute infrared vibrational band intensities of molecular ions determined by direct laser absorption spectroscopy in fast ion beams

    SciTech Connect (OSTI)

    Keim, E.R.; Polak, M.L.; Owrutsky, J.C.; Coe, J.V.; Saykally, R.J. (Department of Chemistry, University of California, Berkeley, CA (USA))

    1990-09-01T23:59:59.000Z

    The technique of direct laser absorption spectroscopy in fast ion beams has been employed for the determination of absolute integrated band intensities ({ital S}{sup 0}{sub {ital v}}) for the {nu}{sub 3} fundamental bands of H{sub 3}O{sup +} and NH{sup +}{sub 4}. In addition, the absolute band intensities for the {nu}{sub 1} fundamental bands of HN{sup +}{sub 2} and HCO{sup +} have been remeasured. The values obtained in units of cm{sup {minus}2} atm{sup {minus}1} at STP are 1880(290) and 580(90) for the {nu}{sub 1} fundamentals of HN{sup +}{sub 2} and HCO{sup +}, respectively; and 4000(800) and 1220(190) for the {nu}{sub 3} fundamentals of H{sub 3}O{sup +} and NH{sup +}{sub 4}, respectively. Comparisons with {ital ab} {ital initio} results are presented.

  2. Electronic structure of Pt based topological Heusler compounds with C1{sub b} structure and 'zero band gap'

    SciTech Connect (OSTI)

    Ouardi, Siham; Shekhar, Chandra; Fecher, Gerhard H.; Kozina, Xeniya; Stryganyuk, Gregory; Felser, Claudia [Institut fuer Anorganische Chemie und Analytische Chemie, Johannes Gutenberg-Universitaet, D-55099 Mainz (Germany); Ueda, Shigenori; Kobayashi, Keisuke [NIMS Beamline Station at SPring-8, National Institute for Materials Science, Hyogo 679-5148 (Japan)

    2011-05-23T23:59:59.000Z

    Besides of their well-known wide range of properties it was recently shown that many of the heavy Heusler semiconductors with 1:1:1 composition and C1{sub b} structure exhibit a zero band gap behavior and are topological insulators induced by their inverted band structure. In the present study, the electronic structure of the Heusler compounds PtYSb and PtLaBi was investigated by bulk sensitive hard x-ray photoelectron spectroscopy. The measured valence band spectra are clearly resolved and in well agreement to the first-principles calculations of the electronic structure of the compounds. The experimental results give clear evidence for the zero band gap state.

  3. Generation of an integrated karyotype of the honey bee (Apis mellifera L.) by banding pattern and fluorescent in situ hybridization

    E-Print Network [OSTI]

    Aquino Perez, Gildardo

    2009-05-15T23:59:59.000Z

    organizer (6 and 12), four submetacentric heterochromatic chromosomes (16, 15, 4 and 13), four euchromatic subtelocentric chromosomes (2, 8, 11 and 14) and four acrocentric chromosomes (3, 5, 7 and 9). In situ nick-translation banding methods were used...

  4. Apparatus and methods for relieving thermally induced stresses in inner and outer bands of thermally cooled turbine nozzle stages

    DOE Patents [OSTI]

    Yu, Yufeng Phillip (Guilderland, NY); Itzel, Gary Michael (Clifton Park, NY); Correia, Victor H. S. (Milton Mills, NH)

    2002-01-01T23:59:59.000Z

    To control the temperature mismatch between the inner and outer bands and covers forming plenums with the inner and outer bands on sides thereof remote from the hot gas path, passages extend from the leading edge of the covers in communication with the hot gases of combustion to the trailing edge of the covers in communication with the hot gas flowpath. A mixing chamber is provided in each passage in communication with compressor discharge air for mixing the hot gases of combustion and compressor discharge air for flow through the passage, thereby heating the cover and minimizing the temperature differential between the inner and outer bands and their respective covers. The passages are particularly useful adjacent the welded or brazed joints between the covers and inner band portions.

  5. Study of band bending effect in Dye Sensitized Solar Cell through Constant-Current-Discharging Voltage Decay

    E-Print Network [OSTI]

    Wang, Xiaoqi

    2012-01-01T23:59:59.000Z

    A measurement method of constant-current-discharging voltage decay is established to characterize the band bending effect in the heterojunction of conducting glass/TiO2 for typical dye-sensitized solar cells. Furthermore, a dark-state electron transport regarding the TiO2 conduction band bending is proposed based upon the viewpoints of thermionic emission mechanism, which suggests an origin of the band bending effect in a theoretical model. This model quantitatively agrees well with our experimental results and indicates that both the Fermi level decay in TiO2 and the potential difference across the heterojunction will lead to the TiO2 conduction band bending downwards.

  6. Band offsets of n-type electron-selective contacts on cuprous oxide (Cu[subscript 2]O) for photovoltaics

    E-Print Network [OSTI]

    Brandt, Riley E.

    The development of cuprous oxide (Cu [subscript 2]O) photovoltaics (PVs) is limited by low device open-circuit voltages. A strong contributing factor to this underperformance is the conduction-band offset between Cu ...

  7. Scent marking in wild banded mongooses: 3. Intrasexual overmarking Neil R. Jordan a,*, Francis Mwanguhya a,b,1

    E-Print Network [OSTI]

    RĂĽedi, Peter

    Scent marking in wild banded mongooses: 3. Intrasexual overmarking in females Neil R. Jordan a, this is the first study to investigate female over- marking in any wild mammal. First, although we found some

  8. DESIGN, GROWTH, FABRICATION AND CHARACTERIZATION OF HIGH-BAND GAP InGaN/GaN SOLAR CELLS

    E-Print Network [OSTI]

    Honsberg, Christiana

    DESIGN, GROWTH, FABRICATION AND CHARACTERIZATION OF HIGH-BAND GAP InGaN/GaN SOLAR CELLS Omkar Jani1 with a band gap of 2.4 eV or greater. InxGa1-xN is one of a few alloys that can meet this key requirement. InGaN.4 eV. InGaN has the appropriate optical properties and has been well demonstrated for light

  9. Wave propagation in ordered, disordered, and nonlinear photonic band gap materials

    SciTech Connect (OSTI)

    Lidorikis, Elefterios

    1999-12-10T23:59:59.000Z

    Photonic band gap materials are artificial dielectric structures that give the promise of molding and controlling the flow of optical light the same way semiconductors mold and control the electric current flow. In this dissertation the author studied two areas of photonic band gap materials. The first area is focused on the properties of one-dimensional PBG materials doped with Kerr-type nonlinear material, while, the second area is focused on the mechanisms responsible for the gap formation as well as other properties of two-dimensional PBG materials. He first studied, in Chapter 2, the general adequacy of an approximate structure model in which the nonlinearity is assumed to be concentrated in equally-spaced very thin layers, or 6-functions, while the rest of the space is linear. This model had been used before, but its range of validity and the physical reasons for its limitations were not quite clear yet. He performed an extensive examination of many aspects of the model's nonlinear response and comparison against more realistic models with finite-width nonlinear layers, and found that the d-function model is quite adequate, capturing the essential features in the transmission characteristics. The author found one exception, coming from the deficiency of processing a rigid bottom band edge, i.e. the upper edge of the gaps is always independent of the refraction index contrast. This causes the model to miss-predict that there are no soliton solutions for a positive Kerr-coefficient, something known to be untrue.

  10. MAPPING H-BAND SCATTERED LIGHT EMISSION IN THE MYSTERIOUS SR21 TRANSITIONAL DISK

    SciTech Connect (OSTI)

    Follette, Katherine B.; Close, Laird [Steward Observatory, The University of Arizona, 933 N Cherry Ave, Tucson, AZ 85721 (United States)] [Steward Observatory, The University of Arizona, 933 N Cherry Ave, Tucson, AZ 85721 (United States); Tamura, Motohide; Hashimoto, Jun; Kwon, Jungmi; Kandori, Ryo [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)] [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Whitney, Barbara [Astronomy Department, University of Wisconsin-Madison, 475 N. Charter Street, Madison, WI 53706 (United States)] [Astronomy Department, University of Wisconsin-Madison, 475 N. Charter Street, Madison, WI 53706 (United States); Grady, Carol [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States)] [Eureka Scientific, 2452 Delmer, Suite 100, Oakland, CA 96002 (United States); Andrews, Sean M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)] [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Wisniewski, John [H.L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W Brooks St Norman, OK 73019 (United States)] [H.L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 W Brooks St Norman, OK 73019 (United States); Brandt, Timothy D.; Dong, Ruobing [Department of Astrophysical Sciences, Princeton University, NJ 08544 (United States)] [Department of Astrophysical Sciences, Princeton University, NJ 08544 (United States); Mayama, Satoshi [The Center for the Promotion of Integrated Sciences, The Graduate University for Advanced Studies (Sokendai), Shonan International Village, Hayama-cho, Miura-gun, Kanagawa 240-0193 (Japan)] [The Center for the Promotion of Integrated Sciences, The Graduate University for Advanced Studies (Sokendai), Shonan International Village, Hayama-cho, Miura-gun, Kanagawa 240-0193 (Japan); Abe, Lyu [Laboratoire Lagrange, UMR7293, Universite de Nice-Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, F-06300 Nice (France)] [Laboratoire Lagrange, UMR7293, Universite de Nice-Sophia Antipolis, CNRS, Observatoire de la Cote d'Azur, F-06300 Nice (France); Brandner, Wolfgang; Feldt, Markus [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany)] [Max Planck Institute for Astronomy, Koenigstuhl 17, D-69117 Heidelberg (Germany); Carson, Joseph [Department of Physics and Astronomy, College of Charleston, 58 Coming St., Charleston, SC 29424 (United States)] [Department of Physics and Astronomy, College of Charleston, 58 Coming St., Charleston, SC 29424 (United States); Currie, Thayne [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street M5S 3H4, Toronto Ontario (Canada)] [Department of Astronomy and Astrophysics, University of Toronto, 50 St. George Street M5S 3H4, Toronto Ontario (Canada); Egner, Sebastian E. [Subaru Telescope, 650 North Aohoku Place, Hilo, HI 96720 (United States)] [Subaru Telescope, 650 North Aohoku Place, Hilo, HI 96720 (United States); Goto, Miwa, E-mail: kfollette@as.arizona.edu [Universitats-Sternwarte Munchen, Ludwig-Maximilians-Universitat, Scheinerstr. 1, D-81679 Munchen (Germany)] [Universitats-Sternwarte Munchen, Ludwig-Maximilians-Universitat, Scheinerstr. 1, D-81679 Munchen (Germany); and others

    2013-04-10T23:59:59.000Z

    We present the first near infrared (NIR) spatially resolved images of the circumstellar transitional disk around SR21. These images were obtained with the Subaru HiCIAO camera, adaptive optics, and the polarized differential imaging technique. We resolve the disk in scattered light at H-band for stellocentric 0.''1 {<=} r {<=} 0.''6 (12 {approx}< r {approx}< 75 AU). We compare our results with previously published spatially resolved 880 {mu}m continuum Submillimeter Array images that show an inner r {approx}< 36 AU cavity in SR21. Radiative transfer models reveal that the large disk depletion factor invoked to explain SR21's sub-mm cavity cannot be 'universal' for all grain sizes. Even significantly more moderate depletions ({delta} = 0.1, 0.01 relative to an undepleted disk) than those that reproduce the sub-mm cavity ({delta} {approx} 10{sup -6}) are inconsistent with our H-band images when they are assumed to carry over to small grains, suggesting that surface grains scattering in the NIR either survive or are generated by whatever mechanism is clearing the disk midplane. In fact, the radial polarized intensity profile of our H-band observations is smooth and steeply inwardly-increasing (r {sup -3}), with no evidence of a break at the 36 AU sub-mm cavity wall. We hypothesize that this profile is dominated by an optically thin disk envelope or atmosphere component. We also discuss the compatibility of our data with the previously postulated existence of a sub-stellar companion to SR21 at r {approx} 10-20 AU, and find that we can neither exclude nor verify this scenario. This study demonstrates the power of multiwavelength imaging of transitional disks to inform modeling efforts, including the debate over precisely what physical mechanism is responsible for clearing these disks of their large midplane grains.

  11. Double Wall Carbon Nanotubes for Wide-Band, Ultrafast Pulse Generation

    E-Print Network [OSTI]

    Hasan, Tawfique; Sun, Zhipei; Tan, PingHeng; Popa, Daniel; Flahaut, Emmanuel; Kelleher, Edmund J. R.; Bonaccorso, Francesco; Wang, Fengqiu; Jiang, Zhe; Torrisi, Felice; Privitera, Giulia; Nicolosi, Valeria; Ferrari, Andrea C.

    2014-04-15T23:59:59.000Z

    Accepted Manuscript: ACS Nano, 2014, 8 (5), pp 4836–4847DOI: 10.1021/nn500767b 1 Double Wall Carbon Nanotubes for Wide-Band, Ultrafast Pulse Generation Tawfique Hasan1,*, Zhipei Sun2, PingHeng Tan3, Daniel Popa1, Emmanuel Flahaut4,5, Edmund J. R... , Polymer Composites, Saturable Absorber, Ultrafast Laser. Accepted Manuscript: ACS Nano, 2014, 8 (5), pp 4836–4847DOI: 10.1021/nn500767b 2 ABSTRACT: We demonstrate wideband ultrafast optical pulse generation at 1, 1.5 and 2?m using a single polymer...

  12. Energy band structure and intrinsic coherent properties in two weakly linked Bose Einstein Condensates

    E-Print Network [OSTI]

    Wei-Dong Li; Yunbo Zhang; J. -Q. Liang

    2003-05-21T23:59:59.000Z

    The energy band structure and energy splitting due to quantum tunneling in two weakly linked Bose-Einstein condensates were calculated by using the instanton method. The intrinsic coherent properties of Bose Josephson junction were investigated in terms of energy splitting. For $E_{C}/E_{J}\\ll 1$, the energy splitting is small and the system is globally phase coherent. In the opposite limit, $E_{C}/E_{J}\\gg 1$, the energy splitting is large and the system becomes a phase dissipation. Our reslults suggest that one should investigate the coherence phenomna of BJJ in proper condition such as $E_{C}/E_{J}\\sim 1$.

  13. Characterization and calibration of 8-channel E-band heterodyne radiometer system for SST-1 tokamak

    SciTech Connect (OSTI)

    Siju, Varsha; Kumar, Dharmendra; Shukla, Praveena; Pathak, S. K. [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)] [Institute for Plasma Research, Bhat, Gandhinagar, Gujarat 382428 (India)

    2014-05-15T23:59:59.000Z

    An 8-channel E-band heterodyne radiometer system (74–86 GHz) is designed, characterized, and calibrated to measure the radial electron temperature profile by measuring Electron Cyclotron Emission spectrum at SST-1 Tokamak. The developed radiometer has a noise equivalent temperature of 1 eV and sensitivity of 5 × 10{sup 9} V/W. In order to precisely measure the absolute value of electron temperature, a calibration measurement of the radiometer system is performed using hot-cold Dicke switch method, which confirms the system linearity.

  14. Analysis of plasma-magnetic photonic crystal with a tunable band gap

    SciTech Connect (OSTI)

    Mehdian, H.; Mohammadzahery, Z.; Hasanbeigi, A. [Department of Physics and Plasma Research Institute of Tarbiat Moallem University, 49 Dr Mofatteh Avenue, Tehran 15614 (Iran, Islamic Republic of)

    2013-04-15T23:59:59.000Z

    In this paper, electromagnetic wave propagation through the one-dimensional plasma-magnetic photonic crystal in the presence of external magnetic field has been analyzed. The dispersion relation, transmission and reflection coefficients have been obtained by using the transfer matrix method. It is investigated how photonic band gap of photonic crystals will be tuned when both dielectric function {epsilon} and magnetic permeability {mu} of the constitutive materials, depend on applied magnetic field. This is shown by one dimensional photonic crystals consisting of plasma and ferrite material layers stacked alternately.

  15. First principles electronic band structure and phonon dispersion curves for zinc blend beryllium chalcogenide

    SciTech Connect (OSTI)

    Dabhi, Shweta, E-mail: venu.mankad@gmail.com; Mankad, Venu, E-mail: venu.mankad@gmail.com; Jha, Prafulla K., E-mail: venu.mankad@gmail.com [Department of Physics, Maharaja Krishnakumasinhji Bhavnagar University, Bhavnagar-364001 (India)

    2014-04-24T23:59:59.000Z

    A detailed theoretical study of structural, electronic and Vibrational properties of BeX compound is presented by performing ab-initio calculations based on density-functional theory using the Espresso package. The calculated value of lattice constant and bulk modulus are compared with the available experimental and other theoretical data and agree reasonably well. BeX (X = S,Se,Te) compounds in the ZB phase are indirect wide band gap semiconductors with an ionic contribution. The phonon dispersion curves are represented which shows that these compounds are dynamically stable in ZB phase.

  16. RF study and simulations of a C-band Barrel Open Cavity (BOC) pulse compressor

    E-Print Network [OSTI]

    Shu, Guan; He, Xiang

    2014-01-01T23:59:59.000Z

    This paper focuses on the RF study of a C-band(5712MHz) BOC pulse compressor. The operating principle of BOC is presented and the technical specifications are determined. The main components of BOC such as the cavity, the matching waveguide, the coupling slots and the tuning rings were numerically simulated by 3-D codes software HFSS and CST Microwave Studio(MWS). The "whispering gallery" mode TM6,1,1 with an unload Q of 100000 was chosen to oscillate in the cavity. An energy multiplication factor of 1.99 and a peak power gain of 6.34 were achieved theoretically.

  17. Electronic band structure imaging of three layer twisted graphene on single crystal Cu(111)

    SciTech Connect (OSTI)

    Marquez Velasco, J. [National Center for Scientific Research “Demokritos,” 15310 Athens (Greece) [National Center for Scientific Research “Demokritos,” 15310 Athens (Greece); Department of Physics, National Technical University of Athens, Athens (Greece); Kelaidis, N.; Xenogiannopoulou, E.; Tsoutsou, D.; Tsipas, P.; Speliotis, Th.; Pilatos, G.; Likodimos, V.; Falaras, P.; Dimoulas, A., E-mail: dimoulas@ims.demokritos.gr [National Center for Scientific Research “Demokritos,” 15310 Athens (Greece); Raptis, Y. S. [Department of Physics, National Technical University of Athens, Athens (Greece)] [Department of Physics, National Technical University of Athens, Athens (Greece)

    2013-11-18T23:59:59.000Z

    Few layer graphene (FLG) is grown on single crystal Cu(111) by Chemical Vapor Deposition, and the electronic valence band structure is imaged by Angle-Resolved Photo-Emission Spectroscopy. It is found that graphene essentially grows polycrystalline. Three nearly ideal Dirac cones are observed along the Cu ?{sup Ż}K{sup Ż} direction in k-space, attributed to the presence of ?4° twisted three layer graphene with negligible interlayer coupling. The number of layers and the stacking order are compatible with Raman data analysis demonstrating the complementarity of the two techniques for a more accurate characterization of FLG.

  18. Recent experimental results from a long-pulse J-band relativistic klystron amplifier developmental effort

    SciTech Connect (OSTI)

    Kato, K.G.; Crouch, D.D.; Sar, D.R.; Speciale, R.A. [Hughes Missile Systems Co., Rancho Cucamonga, CA (United States); Carlsten, B.E.; Fazio, M.V.; Haynes, W.B.; Stringfield, R.M. [Los Alamos National Lab., NM (United States)

    1994-12-31T23:59:59.000Z

    Recent experimental results, supporting simulations, and design modeling are presented from a developmental effort to a produce a long pulse ({approximately}1{mu}s) J-band (5.85-8.2 GHz) relativistic klystron amplifier (RKA) of the high current NRL genealogy. This RKA is designed to operate at approximately 6.6 GHz, with a desired RF output {approximately}700 MW. Conversion of electron beam energy to microwave energy is obtained by a mock magnetically insulated coaxial converter which, in various incarnations, can be made to be either a cavity gap extractor or an inverse cathode.

  19. X-band Scanning ARM Precipitation Radar (X-SAPR) Instrument Handbook

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N

    2012-10-29T23:59:59.000Z

    The X-band scanning ARM cloud radar (X-SAPR) is a full-hemispherical scanning polarimetric Doppler radar transmitting simultaneously in both H and V polarizations. With a 200 kW magnetron transmitter, this puts 100 kW of transmitted power for each polarization. The receiver for the X-SAPR is a Vaisala Sigmet RVP-900 operating in a coherent-on-receive mode. Three X-SAPRs are deployed around the Southern Great Plains (SGP) Central Facility in a triangular array. A fourth X-SAPR is deployed near Barrow, Alaska on top of the Barrow Arctic Research Center.

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

    DOE Patents [OSTI]

    Chandler, David W; Strecker, Kevin E

    2014-04-01T23:59:59.000Z

    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.

  1. Theory of small-polaron band conduction in ultrapure organic crystals

    E-Print Network [OSTI]

    K. Hannewald; P. A. Bobbert

    2004-01-27T23:59:59.000Z

    We present a novel theory of charge-carrier mobilities in organic molecular crystals of high purity. Our approach is based on Holstein's original concept of small-polaron bands but generalized with respect to the inclusion of nonlocal electron-phonon coupling. We derive an explicit expression for the mobilities as a function of temperature and, using ab-initio methods to obtain the material parameters, we demonstrate its predictive power by applying it to naphthalene. The results show a remarkably good agreement with experiments and provide new insight into the difference between electron and hole mobilities as well as their peculiar algebraic and anisotropic temperature dependences.

  2. Waveguides in three-dimensional metallic photonic band-gap materials

    SciTech Connect (OSTI)

    Sigalas, M.M.; Biswas, R.; Ho, K.M.; Soukoulis, C.M. [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States)] [Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011 (United States); Crouch, D.D. [Advanced Electromagnetic Technologies Center, Raytheon Corporation, Rancho Cucamonga, California 91729 (United States)] [Advanced Electromagnetic Technologies Center, Raytheon Corporation, Rancho Cucamonga, California 91729 (United States)

    1999-08-01T23:59:59.000Z

    We theoretically investigate waveguide structures in three-dimensional metallic photonic band-gap (MPBG) materials. The MPBG materials used in this study consist of a three-dimensional mesh of metallic wires embedded in a dielectric. An {ital L}-shaped waveguide is created by removing part of the metallic wires. Using finite difference time domain simulations, we found that an 85{percent} transmission efficiency can be achieved through the 90{degree} bend with just three unit cell thickness MPBG structures. thinsp {copyright} {ital 1999} {ital The American Physical Society}

  3. Sub-Doppler Stark Spectroscopy in the A?X (1,0) Band of CN

    SciTech Connect (OSTI)

    Hall, G.E.; Hause, M.L.; Sears, T.J.

    2009-11-26T23:59:59.000Z

    The effect of external electric fields has been measured in hyperfine-resolved sub-Doppler transitions in the A {sup 2}{Pi}-X {sup 2}{Sigma} (1,0) band of the CN radical near 10900 cm{sup -1}. Static electric fields less than 1 kV/cm are sufficient to mix the most closely spaced {Lambda}-dpublets in the A state, leading to Stark spectra with both new and shifted resonances. Simulations of the saturation-dip Stark spectral line profiles allow extraction of the A-state permanent electric dipole moment with a magnitude of 0.06 {+-} 0.02 D.

  4. Monolayer-induced band shifts at Si(100) and Si(111) surfaces

    SciTech Connect (OSTI)

    Mäkinen, A. J., E-mail: Antti.Makinen@nrl.navy.mil; Kim, Chul-Soo; Kushto, G. P. [Naval Research Laboratory, 4555 Overlook Avenue, Washington, DC 20375 (United States)

    2014-01-27T23:59:59.000Z

    We report our study of the interfacial electronic structure of Si(100) and Si(111) surfaces that have been chemically modified with various organic monolayers, including octadecene and two para-substituted benzene derivatives. X-ray photoelectron spectroscopy reveals an upward band shift, associated with the assembly of these organic monolayers on the Si substrates, that does not correlate with either the dipole moment or the electron withdrawing/donating character of the molecular moieties. This suggests that the nature and quality of the self-assembled monolayer and the intrinsic electronic structure of the semiconductor material define the interfacial electronic structure of the functionalized Si(100) and Si(111) surfaces.

  5. DOE/SC-ARM/TR-122 G-Band Vapor Radiometer Precipitable Water

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville Power Administration wouldDECOMPOSITION OF CALCIUMCOSTDOENuclear1382 THEDOE0-354-15022252 G-Band

  6. Evidence of Eu{sup 2+} 4f electrons in the valence band spectra of EuTiO{sub 3} and EuZrO{sub 3}

    SciTech Connect (OSTI)

    Kolodiazhnyi, T. [National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Valant, M. [Materials Research Laboratory, University of Nova Gorica, Vipavska 13, 5000 Nova Gorica (Slovenia); Williams, J. R. [International Center for Young Scientists (ICYS), MANA, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Bugnet, M.; Botton, G. A. [Department of Materials Science and Engineering, McMaster University, Hamilton, Ontario L8S 4L7 (Canada); Ohashi, N. [International Center for Materials Nanoarchitectonics, MANA, National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Sakka, Y. [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan)

    2012-10-15T23:59:59.000Z

    We report on optical band gap and valence electronic structure of two Eu{sup 2+}-based perovskites, EuTiO{sub 3} and EuZrO{sub 3} as revealed by diffuse optical scattering, electron energy loss spectroscopy, and valence-band x-ray photoelectron spectroscopy. The data show good agreement with the first-principles studies in which the top of the valence band structure is formed by the narrow Eu 4f{sup 7} electron band. The O 2p band shows the features similar to those of the Ba(Sr)TiO{sub 3} perovskites except that it is shifted to higher binding energies. Appearance of the Eu{sup 2+} 4f{sup 7} band is a reason for narrowing of the optical band gap in the title compounds as compared to their Sr-based analogues.

  7. Periodic dielectric structure for production of photonic band gap and devices incorporating the same

    DOE Patents [OSTI]

    Ho, Kai-Ming (Ames, IA); Chan, Che-Ting (Ames, IA); Soukoulis, Costas (Ames, IA)

    1994-08-02T23:59:59.000Z

    A periodic dielectric structure which is capable of producing a photonic band gap and which is capable of practical construction. The periodic structure is formed of a plurality of layers, each layer being formed of a plurality of rods separated by a given spacing. The material of the rods contrasts with the material between the rods to have a refractive index contrast of at least two. The rods in each layer are arranged with their axes parallel and at a given spacing. Adjacent layers are rotated by 90.degree., such that the axes of the rods in any given layer are perpendicular to the axes in its neighbor. Alternating layers (that is, successive layers of rods having their axes parallel such as the first and third layers) are offset such that the rods of one are about at the midpoint between the rods of the other. A four-layer periocity is thus produced, and successive layers are stacked to form a three-dimensional structure which exhibits a photonic band gap. By virtue of forming the device in layers of elongate members, it is found that the device is susceptible of practical construction.

  8. Nature of the narrow optical band in H*-aggregates: Dozy-chaos–exciton coupling

    SciTech Connect (OSTI)

    Egorov, Vladimir V., E-mail: egorov@photonics.ru [Photochemistry Center, Russian Academy of Sciences, Moscow, 119421 (Russian Federation)

    2014-07-15T23:59:59.000Z

    Dozy chaos emerges as a combined effect of the collective chaotic motion of electrons and nuclei, and their chaotic electromagnetic interactions in the transient state of molecules experiencing quantum transitions. Following earlier discussions of the well-known Brönsted relations for proton-transfer reactions; the temperature-dependent electron transfer in Langmuir–Blodgett films; the shape of the optical bands of polymethine dye monomers, their dimers, and J-aggregates, this paper reports one more application of the dozy-chaos theory of molecular quantum transitions. The qualitative and quantitative explanations for shape of a narrow and blue-shifted optical absorption band in H{sup *}-aggregates is given on the basis of the dozy-chaos theory by taking into account the dozy-chaos–exciton coupling effect. It is emphasized that in the H{sup *}-aggregate chromophore (dimer of cyclic bis-thiacarbocyanines) there is a competition between two Frenkel exciton transitions through the chaotic reorganization motion of nuclear environment. As a result, the highly organized quantum transition to the upper exciton state becomes an exciton-induced source of dozy chaos for the low organized transition to the lower exciton state. This manifests itself in appearing the narrow peak and broad wing in the optical spectrum pattern of H{sup *}-aggregates. A similar enhancement in the H{sup *}-effect caused by the strengthening of the exciton coupling in H{sup *}-dimers, which could be achieved by synthesizing tertiary and quarternary thiacarbocyanine monomers, is predicted.

  9. FABSOAR--A Fabry-Perot Spectrometer for Oxygen A-band Research Final Technical Report

    SciTech Connect (OSTI)

    Watchorn, Steven

    2010-09-10T23:59:59.000Z

    Because this was a Phase I project, it did not add extensively to the body of A-band knowledge. There was no basic research performed on that subject. The principal addition was that a mechanical and optical design for a triple-etalon Fabry-Perot interferometer (FABSOAR) capable of A-band sensing was sketched out and shown to be within readily feasible instrument fabrication parameters. The parameters for the proposed triple-etalon Fabry-Perot were shown to be very similar to existing Fabry-Perots built by Scientific Solutions. The mechanical design for the FABSOAR instrument incorporated the design of previous Scientific Solutions imagers, condensing the three three-inch-diameter etalons into a single, sturdy tube. The design allowed for the inclusion of a commercial off-the-shelf (COTS) filter wheel and a thermocooled CCD detector from Andor. The tube has supports to mount to a horizontal or vertical opticaltable surface, and was to be coupled to a Scientific Solutions pointing head at the Millstone Hill Observatory in Massachusetts for Phase II calibration and testing.

  10. Strain-engineered band parameters of graphene-like SiC monolayer

    SciTech Connect (OSTI)

    Behera, Harihar, E-mail: harihar@theglocaluniversity.in [School of Technology, The Glocal University, Mirzapur Pole, Dist.-Saharanpur, U.P.-247001, India and Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India); Mukhopadhyay, Gautam, E-mail: gmukh@phy.iitb.ac.in [Department of Physics, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India)

    2014-10-06T23:59:59.000Z

    Using full-potential density functional theory (DFT) calculations we show that the band gap and effective masses of charge carriers in SiC monolayer (ML-SiC) in graphene-like two-dimensional honeycomb structure are tunable by strain engineering. ML-SiC was found to preserve its flat 2D graphene-like structure under compressive strain up to 7%. A transition from indirect-to-direct gap-phase is predicted to occur for a strain value lying within the interval (1.11 %, 1.76%). In both gap-phases band gap decreases with increasing strain, although the rate of decrease is different in the two gap-phases. Effective mass of electrons show a non-linearly decreasing trend with increasing tensile strain in the direct gap-phase. The strain-sensitive properties of ML-SiC, may find applications in future strain-sensors, nanoelectromechanical systems (NEMS) and nano-optomechanical systems (NOMS) and other nano-devices.

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

    SciTech Connect (OSTI)

    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)

    2014-01-14T23:59:59.000Z

    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.

  12. Multiple-band reflective polarization converter using U-shaped metamaterial

    SciTech Connect (OSTI)

    Huang, Xiaojun [College of Physical Science and Technology, Central China Normal University, Wuhan 430079 (China); Department of Physics, Kashgar Teachers College, Kashgar 844000 (China); Yang, Dong [College of Physics and Electronics Science, Hubei Normal University, Huangshi 435002 (China); Yang, Helin, E-mail: emyang@mail.ccnu.edu.cn [College of Physical Science and Technology, Central China Normal University, Wuhan 430079 (China)

    2014-03-14T23:59:59.000Z

    A multiple-band metamaterial reflective polarization converter (RPC) is proposed, which is composed of the dielectric substrate sandwiched with U-shaped metallic patterns and continuous metal film. The proposed U-shaped metamaterial RPC (UMM-RPC) can convert a linearly polarized wave to its cross polarized wave at the three resonant frequencies, which also can convert the linearly polarized wave to circularly polarized wave at other three resonant frequencies. Furthermore, the proposed UMM-RPC can maintain the same conversional direction at the three resonant frequencies when incident on a circularly polarized wave. The simulated and measured results are in agreement in the entire frequency range, and the polarization conversion ratio is over 90% for both linear and circular polarizations. The surface current distributions of the UMM-RPC are discussed to look into the physical mechanism. The proposed UMM-RPC has simple geometry but more operating frequency bands compared to the previous designs and can be used in applications such as antenna radome, remote sensors, and radiometer.

  13. Study of Gravitational Lens Chromaticity from Ground-based Narrow Band Photometry

    E-Print Network [OSTI]

    Mosquera, Ana M; Mediavilla, Evencio; Kochanek, Christopher S

    2010-01-01T23:59:59.000Z

    We present observations of wavelength-dependent flux ratios for 4 gravitational lens systems (SDSS~J1650+4251, HE~0435$-$1223, FBQ 0951+2635, and Q~0142$-$100) obtained with the Nordic Optical telescope (NOT). The use of narrow band photometry, as well as the excellent seeing conditions during the observations, allow us to set good baselines to study their chromatic behavior. For SDSS~J1650+4251 we determine the extinction curve of the dust in the $z_L=0.58$ lens galaxy, and find that the 2175 \\AA \\ feature is absent. In the case of HE~0435$-$1223 we clearly detect chromatic microlensing. This allows us to estimate the wavelength dependent size of the accretion disk. We found an R-band disk size of $r^{R}_s=13\\pm5$ light days for a linear prior on $r^{R}_s$ and of $r^{R}_s=7\\pm6$ light days for a logarithmic prior. For a power law size-wavelength scaling of $r_s\\propto\\lambda^{p}$, we were able to constrain the value of the exponent to $p=1.3\\pm0.3$ for both $r^{R}_s$ priors, which is in agreement with the te...

  14. Fluorescent growth bands in irradiated-bitumen nodules: Evidence of episodic hydrocarbon migration

    SciTech Connect (OSTI)

    Rasmussen, B. [Univ. of Western Australia, Nedlands (Australia)

    1997-01-01T23:59:59.000Z

    Minute rims of solid bitumen ({approximately}40-50 {mu}m thick) surround detrital radioactive grains in the Permian-Triassic sandstones and Arranoo Member of the Kockatea Shale from the northern Perth basin, Australia. The bitumen formed as Th- and U-bearing minerals (monazite, xenotime, zircon, thorite) irradiated and immobilized fluid hydrocarbons coming within range of alpha-particle emissions. using transmitted light and scanning electron microscopy and rims appear compositionally homogeneous, but under blue/violet epifluorescent illumination the bitumen displays complex concentric and contorted banding. These fluorescent textures indicate that multiple influxes of hydrocarbons passed through the reservoir sandstones. Following radiation-induced immobilization of hydrocarbons from the first oil influx, the bitumen nodules grew through a process of swelling and expansion outward form the mineral core during subsequent oil influxes, producing graded fluorescent growth bands. Oil droplets and lamellae also were adsorbed onto the outer portion of the nodules. Such bitumen nodules are a new and potentially important source of data for understanding the movement of hydrocarbons in sedimentary basins, specifically for identifying hydrocarbon pathways, the number of discrete hydrocarbon pulses, and the relative timing of oil migration.

  15. Fermion space charge in narrow-band gap semiconductors, Weyl semimetals and around highly charged nuclei

    E-Print Network [OSTI]

    Eugene B. Kolomeisky; Joseph P. Straley; Hussain Zaidi

    2013-10-15T23:59:59.000Z

    The field of charged impurities in narrow-band gap semiconductors and Weyl semimetals can create electron-hole pairs when the total charge $Ze$ of the impurity exceeds a value $Z_{c}e$. The particles of one charge escape to infinity, leaving a screening space charge. The result is that the observable dimensionless impurity charge $Q_{\\infty}$ is less than $Z$ but greater than $Z_{c}$. There is a corresponding effect for nuclei with $Z >Z_{c} \\approx 170$, however in the condensed matter setting we find $Z_{c} \\simeq 10$. Thomas-Fermi theory indicates that $Q_{\\infty} = 0$ for the Weyl semimetal, but we argue that this is a defect of the theory. For the case of a highly-charged recombination center in a narrow band-gap semiconductor (or of a supercharged nucleus), the observable charge takes on a nearly universal value. In Weyl semimetals the observable charge takes on the universal value $Q_{\\infty} = Z_{c}$ set by the reciprocal of material's fine structure constant.

  16. Fluorine Substituted Conjugated Polymer of Medium Band Gap Yields 7% Efficiency in Polymer--Fullerene Solar Cells

    SciTech Connect (OSTI)

    Price, S C; Stuart, Andrew C.; Yang, L; Zhou, H; You, Wei

    2011-01-01T23:59:59.000Z

    Recent research advances on conjugated polymers for photovoltaic devices have focused on creating low band gap materials, but a suitable band gap is only one of many performance criteria required for a successful conjugated polymer. This work focuses on the design of two medium band gap (?2.0 eV) copolymers for use in photovoltaic cells which are designed to possess a high hole mobility and low highest occupied molecular orbital and lowest unoccupied molecular orbital energy levels. The resulting fluorinated polymer PBnDT?FTAZ exhibits efficiencies above 7% when blended with [6,6]-phenyl C{sub 61}-butyric acid methyl ester in a typical bulk heterojunction, and efficiencies above 6% are still maintained at an active layer thicknesses of 1 ?m. PBnDT?FTAZ outperforms poly(3-hexylthiophene), the current medium band gap polymer of choice, and thus is a viable candidate for use in highly efficient tandem cells. PBnDT?FTAZ also highlights other performance criteria which contribute to high photovoltaic efficiency, besides a low band gap.

  17. Laboratory Determination of the Infrared Band Strengths of Pyrene Frozen in Water Ice: Implications for the Composition of Interstellar Ices

    E-Print Network [OSTI]

    Hardegree-Ullman, E E; Boogert, A C A; Lignell, H; Allamandola, L J; Stapelfeldt, K R; Werner, M

    2014-01-01T23:59:59.000Z

    Broad infrared emission features (e.g., at 3.3, 6.2, 7.7, 8.6, and 11.3 microns) from the gas phase interstellar medium have long been attributed to polycyclic aromatic hydrocarbons (PAHs). A significant portion (10%-20%) of the Milky Way's carbon reservoir is locked in PAH molecules, which makes their characterization integral to our understanding of astrochemistry. In molecular clouds and the dense envelopes and disks of young stellar objects (YSOs), PAHs are expected to be frozen in the icy mantles of dust grains where they should reveal themselves through infrared absorption. To facilitate the search for frozen interstellar PAHs, laboratory experiments were conducted to determine the positions and strengths of the bands of pyrene mixed with H2O and D2O ices. The D2O mixtures are used to measure pyrene bands that are masked by the strong bands of H2O, leading to the first laboratory determination of the band strength for the CH stretching mode of pyrene in water ice near 3.25 microns. Our infrared band str...

  18. Equivalent Circuit Description of Non-compensated n-p Codoped TiO2 as Intermediate Band Solar Cells

    E-Print Network [OSTI]

    Tian-Li Feng; Guang-Wei Deng; Yi Xia; Feng-Cheng Wu; Ping Cui; Hai-Ping Lan; Zhen-Yu Zhang

    2010-12-09T23:59:59.000Z

    The novel concept of non-compensated n-p codoping has made it possible to create tunable intermediate bands in the intrinsic band gap of TiO2, making the codoped TiO2 a promising material for developing intermediate band solar cells (IBSCs). Here we investigate the quantum efficiency of such IBSCs within two scenarios - with and without current extracted from the extended intermediate band. Using the ideal equivalent circuit model, we find that the maximum efficiency of 57% in the first scenario and 53% in the second are both much higher than the Shockley-Queisser limit from single gap solar cells. We also obtain various key quantities of the circuits, a useful step in realistic development of TiO2 based solar cells invoking device integration. These equivalent circuit results are also compared with the efficiencies obtained directly from consideration of electron transition between the energy bands, and both approaches reveal the intriguing existence of double peaks in the maximum quantum efficiency as a function of the relative location of IBs.

  19. Equivalent Circuit Description of Non-compensated n-p Codoped TiO2 as Intermediate Band Solar Cells

    E-Print Network [OSTI]

    Feng, Tian-Li; Xia, Yi; Wu, Feng-Cheng; Cui, Ping; Lan, Hai-Ping; Zhang, Zhen-Yu

    2010-01-01T23:59:59.000Z

    The novel concept of non-compensated n-p codoping has made it possible to create tunable intermediate bands in the intrinsic band gap of TiO2, making the codoped TiO2 a promising material for developing intermediate band solar cells (IBSCs). Here we investigate the quantum efficiency of such IBSCs within two scenarios - with and without current extracted from the extended intermediate band. Using the ideal equivalent circuit model, we find that the maximum efficiency of 57% in the first scenario and 53% in the second are both much higher than the Shockley-Queisser limit from single gap solar cells. We also obtain various key quantities of the circuits, a useful step in realistic development of TiO2 based solar cells invoking device integration. These equivalent circuit results are also compared with the efficiencies obtained directly from consideration of electron transition between the energy bands, and both approaches reveal the intriguing existence of double peaks in the maximum quantum efficiency as a fun...

  20. Room temperature ferromagnetism in Co-doped amorphous carbon composites from the spin polarized semiconductor band

    SciTech Connect (OSTI)

    Hsu, H. S., E-mail: hshsu@mail.nptu.edu.tw; Chien, P. C.; Chang, Y. Y. [Department of Applied Physics, National Pingtung University, Pingtung 900, Taiwan (China); Sun, S. J. [Department of Applied Physics, National University of Kaohsiung, Kaohsiung 811, Taiwan (China); Lee, C. H. [Department of Engineering and System Science, National Tsing-Hua University, Hsinchu 300, Taiwan (China)

    2014-08-04T23:59:59.000Z

    This study provides conclusive evidence of room temperature ferromagnetism in Co-doped amorphous carbon (a-C) composites from the spin polarized semiconductor band. These composites are constructed from discontinuous [Co(3?nm)/a-C(d{sub c} nm)]{sub 5} multilayers with d{sub c}?=?3?nm and d{sub c}?=?6?nm. Only remnant circular dichroism (CD) was observed from the d{sub c}?=?3?nm sample but not when d{sub c}?=?6?nm. In addition, the remnant CD peaks at 5.5?eV, which is comparable with the absorption peak associated with the C ?-?* gap transition. We suggest that the possible mechanism for this coupling can be considered as a magnetic proximity effect in which a ferromagnetic moment in the C medium is induced by Co/C interfaces.

  1. H-BAND IMAGE OF A PLANETARY COMPANION AROUND HR 8799 IN 2002

    SciTech Connect (OSTI)

    Fukagawa, Misato; Fujita, Yutaka; Shibai, Hiroshi [Department of Earth and Space Science, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043 (Japan); Itoh, Yoichi; Oasa, Yumiko [Graduate School of Science, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo 657-8501 (Japan); Tamura, Motohide [Department of Astronomical Science, Graduate University for Advanced Studies (SOKENDAI), 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); Hayashi, Saeko S.; Hayashi, Masahiko [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)

    2009-05-01T23:59:59.000Z

    The discovery of three planetary companions around HR 8799 marked a significant epoch in direct imaging of extrasolar planets. Given the importance of this system, we re-analyzed H-band images of HR 8799 obtained with the Subaru 36-elements adaptive optics (AO) in 2002 July. The low-order AO imaging combined with the classical point-spread function (PSF) subtractions even revealed the extrasolar planet, HR 8799b. Our observations in 2002 confirmed that it has been orbiting HR 8799 in a counterclockwise direction. The flux of HR 8799b was consistent with those in the later epochs within the uncertainty of 0.25 mag, further supporting the planetary mass estimate by Marois et al.

  2. EXCITATION OF THE AROMATIC INFRARED EMISSION BANDS: CHEMICAL ENERGY IN HYDROGENATED AMORPHOUS CARBON PARTICLES?

    SciTech Connect (OSTI)

    Duley, W. W. [Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada); Williams, D. A., E-mail: wwduley@uwaterloo.ca [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2011-08-20T23:59:59.000Z

    We outline a model for the heating of hydrogenated amorphous carbon (HAC) dust via the release of stored chemical energy and show that this energy ({approx}12 kJ mole{sup -1}) is sufficient to heat dust grains of classical size (50-1000 A) to temperatures at which they can emit at 3.3 {mu}m and other 'UIR' wavelengths. Using laboratory data, we show that this heating process is consistent with a concentration of a few percent of dangling bonds in HAC and may be initiated by the recombination of trapped H atoms. We suggest that the release of chemical energy from dust represents an additional source of excitation for the UIR bands relaxing the previous requirement that only stochastically heated molecules having fewer than {approx}50 atoms can produce emission at 3.3 {mu}m.

  3. Microwave band gap and cavity mode in spoof-insulator-spoof waveguide with multiscale structured surface

    E-Print Network [OSTI]

    Zhang, Qiang; Han, Dezhuan; Qin, Fei Fei; Zhang, Xiao Ming; Yao, Yong

    2015-01-01T23:59:59.000Z

    We propose a multiscale spoof-insulator-spoof (SIS) waveguide by introducing periodic geometry modulation in the wavelength scale to a SIS waveguide made of perfect electric conductor. The MSIS consists of multiple SIS subcells. The dispersion relationship of the fundamental guided mode of the spoof surface plasmon polaritons (SSPPs) is studied analytically within the small gap approximation. It is shown that the multiscale SIS possesses microwave band gap (MBG) due to the Bragg scattering. The "gap maps" in the design parameter space are provided. We demonstrate that the geometry of the subcells can efficiently adjust the effective refraction index of the elementary SIS and therefore further control the width and the position of the MBG. The results are in good agreement with numerical calculations by the finite element method (FEM). For finite-sized MSIS of given geometry in the millimeter scale, FEM calculations show that the first-order symmetric SSPP mode has zero transmission in the MBG within frequency...

  4. Dual Band Electrodes in Generator-Collector Mode: Simultaneous Measurement of Two Species

    E-Print Network [OSTI]

    Barnes, Edward O; Dale, Sara E C; Marken, Frank; Compton, Richard G

    2013-01-01T23:59:59.000Z

    A computational model for the simulation of a double band collector-generator experiment is applied to the situation where two electrochemical reactions occur concurrently. It is shown that chronoamperometric measurements can be used to take advantage of differences in diffusion coefficients to measure the concentrations of both electroactive species simultaneously, by measuring the time at which the collection efficiency reaches a specific value. The separation of the electrodes is shown to not affect the sensitivity of the method (in terms of percentage changes in the measured time to reach the specified collection efficiency), but wider gaps can provide a greater range of (larger) absolute values of this characteristic time. It is also shown that measuring the time taken to reach smaller collection efficiencies can allow for the detection of smaller amounts of whichever species diffuses faster. The case of a system containing both ascorbic acid and opamine in water is used to exemplify the method, and it i...

  5. Optical-fiber source of polarization-entangled photon pairs in the 1550nm telecom band

    E-Print Network [OSTI]

    Xiaoying Li; Paul L. Voss; Jay E. Sharping; Prem Kumar

    2004-08-12T23:59:59.000Z

    We present a fiber based source of polarization-entangled photon pairs that is well suited for quantum communication applications in the 1550nm band of standard fiber-optic telecommunications. Polarization entanglement is created by pumping a nonlinear-fiber Sagnac interferometer with two time-delayed orthogonally-polarized pump pulses and subsequently removing the time distinguishability by passing the parametrically scattered signal-idler photon pairs through a piece of birefringent fiber. Coincidence detection of the signal-idler photons yields biphoton interference with visibility greater than 90%, while no interference is observed in direct detection of either the signal or the idler photons. All four Bell states can be prepared with our setup and we demonstrate violations of CHSH form of Bell's inequalities by up to 10 standard deviations of measurement uncertainty.

  6. Augustine Band of Cahuilla Indians Energy Conservation and Options Analysis - Final Report

    SciTech Connect (OSTI)

    Paul Turner

    2008-07-11T23:59:59.000Z

    The Augustine Band of Cahuilla Indians was awarded a grant through the Department of Energy First Steps program in June of 2006. The primary purpose of the grant was to enable the Tribe to develop energy conservation policies and a strategy for alternative energy resource development. All of the work contemplated by the grant agreement has been completed and the Tribe has begun implementing the resource development strategy through the construction of a 1.0 MW grid-connected photovoltaic system designed to offset a portion of the energy demand generated by current and projected land uses on the Tribe’s Reservation. Implementation of proposed energy conservation policies will proceed more deliberately as the Tribe acquires economic development experience sufficient to evaluate more systematically the interrelationships between conservation and its economic development goals.

  7. Intermediate-band photosensitive device with quantum dots having tunneling barrier embedded in organic matrix

    DOE Patents [OSTI]

    Forrest, Stephen R. (Ann Arbor, MI)

    2008-08-19T23:59:59.000Z

    A plurality of quantum dots each have a shell. The quantum dots are embedded in an organic matrix. At least the quantum dots and the organic matrix are photoconductive semiconductors. The shell of each quantum dot is arranged as a tunneling barrier to require a charge carrier (an electron or a hole) at a base of the tunneling barrier in the organic matrix to perform quantum mechanical tunneling to reach the respective quantum dot. A first quantum state in each quantum dot is between a lowest unoccupied molecular orbital (LUMO) and a highest occupied molecular orbital (HOMO) of the organic matrix. Wave functions of the first quantum state of the plurality of quantum dots may overlap to form an intermediate band.

  8. Intermediate-band photosensitive device with quantum dots embedded in energy fence barrier

    DOE Patents [OSTI]

    Forrest, Stephen R. (Ann Arbor, MI); Wei, Guodan (Ann Arbor, MI)

    2010-07-06T23:59:59.000Z

    A plurality of layers of a first semiconductor material and a plurality of dots-in-a-fence barriers disposed in a stack between a first electrode and a second electrode. Each dots-in-a-fence barrier consists essentially of a plurality of quantum dots of a second semiconductor material embedded between and in direct contact with two layers of a third semiconductor material. Wave functions of the quantum dots overlap as at least one intermediate band. The layers of the third semiconductor material are arranged as tunneling barriers to require a first electron and/or a first hole in a layer of the first material to perform quantum mechanical tunneling to reach the second material within a respective quantum dot, and to require a second electron and/or a second hole in a layer of the first semiconductor material to perform quantum mechanical tunneling to reach another layer of the first semiconductor material.

  9. C-Band Scanning ARM Precipitation Radar (C-SAPR) Handbook

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N

    2012-11-13T23:59:59.000Z

    The C-band scanning ARM precipitation radar (C-SAPR) is a scanning polarimetric Doppler radar transmitting simultaneously in both H and V polarizations. With a 350-kW magnetron transmitter, this puts 125 kW of transmitted power for each polarization. The receiver for the C-SAPR is a National Center for Atmospheric Research (NCAR) -developed Hi-Q system operating in a coherent-on-receive mode. The ARM Climate Research Facility operates two C-SAPRs; one of them is deployed near the Southern Great Plains (SGP) Central Facility near the triangular array of X-SAPRs, and the second C-SAPR is deployed at ARM’s Tropical Western Pacific (TWP) site on Manus Island in Papua New Guinea.

  10. Catalyzed Water Oxidation by Solar Irradiation of Band-Gap-Narrowed Semiconductors (Part 1. Overview).

    SciTech Connect (OSTI)

    Fujita,E.; Khalifah, P.; Lymar, S.; Muckerman, J.T.; Rodgriguez, J.

    2008-03-18T23:59:59.000Z

    The objectives of this report are: (1) Investigate the catalysis of water oxidation by cobalt and manganese hydrous oxides immobilized on titania or silica nanoparticles, and dinuclear metal complexes with quinonoid ligands in order to develop a better understanding of the critical water oxidation chemistry, and rationally search for improved catalysts. (2) Optimize the light-harvesting and charge-separation abilities of stable semiconductors including both a focused effort to improve the best existing materials by investigating their structural and electronic properties using a full suite of characterization tools, and a parallel effort to discover and characterize new materials. (3) Combine these elements to examine the function of oxidation catalysts on Band-Gap-Narrowed Semiconductor (BGNSC) surfaces and elucidate the core scientific challenges to the efficient coupling of the materials functions.

  11. Photonic band gap of a graphene-embedded quarter-wave stack

    SciTech Connect (OSTI)

    Fan, Yuancheng [Ames Laboratory; Wei, Zeyong [Tongji University; Li, Hongqiang [Tongji University; Chen, Hong [Tongji University; Soukoulis, Costas M [Ames Laboratory

    2013-12-10T23:59:59.000Z

    Here, we present a mechanism for tailoring the photonic band structure of a quarter-wave stack without changing its physical periods by embedding conductive sheets. Graphene is utilized and studied as a realistic, two-dimensional conductive sheet. In a graphene-embedded quarter-wave stack, the synergic actions of Bragg scattering and graphene conductance contributions open photonic gaps at the center of the reduced Brillouin zone that are nonexistent in conventional quarter-wave stacks. Such photonic gaps show giant, loss-independent density of optical states at the fixed lower-gap edges, of even-multiple characteristic frequency of the quarter-wave stack. The conductive sheet-induced photonic gaps provide a platform for the enhancement of light-matter interactions.

  12. Antarctica X-band MiniSAR crevasse detection radar : final report.

    SciTech Connect (OSTI)

    Sander, Grant J.; Bickel, Douglas Lloyd

    2007-09-01T23:59:59.000Z

    This document is the final report for the Antarctica Synthetic Aperture Radar (SAR) Project. The project involved the modification of a Sandia National Laboratories MiniSAR system to operate at X-band in order to assess the feasibility of an airborne radar to detect crevasses in Antarctica. This radar successfully detected known crevasses at various geometries. The best results were obtained for synthetic aperture radar resolutions of at most one foot and finer. In addition to the main goal of detecting crevasses, the radar was used to assess conops for a future operational radar. The radar scanned large areas to identify potential safe landing zones. In addition, the radar was used to investigate looking at objects on the surface and below the surface of the ice. This document includes discussion of the hardware development, system capabilities, and results from data collections in Antarctica.

  13. Commissioning of the First Klystron-Based X-Band Power Source at CERN

    E-Print Network [OSTI]

    Kovermann, J; Curt, S; Doebert, S; Naon, M; McMonagle, G; Paju, E; Rey, S; Riddone, G; Schirm, K; Syratchev, I; Timeo, L; Wuensch, W; Hamdi, A; Peauger, FF; Eichner, J; Haase, A; Sprehn, D

    2012-01-01T23:59:59.000Z

    A new klystron based X-band rf power source operating at 11.994 GHz has been installed and started to be commissioned at CERN in collaboration with CEA Saclay and SLAC for CLIC accelerating structure tests. The system comprises a solid state high voltage modulator, an XL5 klystron developed by SLAC, a cavity based SLED type pulse compressor, the necessary low level rf system including rf diagnostics and interlocks and the surrounding vacuum, cooling and controls infrastructure. The system is designed to produce up to 50 MW rf pulses of 1500 ns pulse width and 50 Hz repetition rate. After pulse compression, up to 100 MW of rf power at 250 ns pulse width will be available in the structure test bunker. This paper describes in more detail this setup and the process of commissioning which is necessary to arrive at the design performance.

  14. Discovery of Correlated Behavior Between the HXR and the Radio Bands in Cygnus X-3

    E-Print Network [OSTI]

    M. L. McCollough; C. R. Robinson; S. N. Zhang; B. A. Harmon; R. M. Hjellming; E. B. Waltman; R. S. Foster; F. D. Ghigo; M. S. Briggs; G. N. Pendleton; K. J. Johnston

    1998-10-14T23:59:59.000Z

    Using CGRO/BATSE hard X-ray (HXR) data and GHz radio monitoring data from the Green Bank Interferometer (GBI), we have performed a long term study ($\\sim$ 1800 days) of the unusual X-ray binary Cyg X-3 resulting in the discovery of a remarkable relationship between these two wavelength bands. We find that, during quiescent radio states, the radio flux is strongly anticorrelated with the intensity of the HXR emission. The relationship switches to a correlation with the onset of major radio flaring activity. During major radio flaring activity the HXR drops to a very low intensity during quenching in the radio and recovers during the radio flare. Injection of plasma into the radio jets of Cyg X-3 occurs during changes in the HXR emission and suggests that disk-related and jet-related components are responsible for the high energy emission.

  15. Photoinduced band filling in strongly confined colloidal PbS quantum dots

    SciTech Connect (OSTI)

    Ullrich, B., E-mail: bruno@fis.unam.mx [Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210 (Mexico); Ullrich Photonics LLC, Wayne, Ohio 43466 (United States); Xi, H. [Department of Physics and Astronomy, Bowling Green State University, Bowling Green, Ohio 43403-0209 (United States); Wang, J. S. [Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright Patterson AFB, Ohio 45433-7707 (United States)

    2014-06-21T23:59:59.000Z

    Increase in continuous wave laser excitation (6?W/cm{sup 2} to 120?W/cm{sup 2}) of colloidal PbS quantum dots in the strongly quantized regime (diameters 2.0?nm and 4.7?nm) deposited on semi-insulating GaAs and glass causes a clear blue shift (0.019?eV and 0.080?eV) of the emission spectra. Proof of the applicability of a dynamic three-dimensional band filling model is the significance of the presented results and demonstrates the effective electronic coupling in quantum dot arrays similar to superlattices. The work also reveals the influence of quantum dot sizes on photo-doping effects.

  16. 150-MW S-band klystron program at the Stanford Linear Accelerator Center

    SciTech Connect (OSTI)

    Sprehn, D.; Caryotakis, G.; Phillips, R.M.

    1996-07-01T23:59:59.000Z

    Two S-Band klystrons operating at 150 MW have been designed, fabricated and tested at the Stanford Linear Accelerator Center (SLAC) during the past two years for use in an experimental accelerator at Deutsches Elektronen-Synchrotron (DESY) in Hamburg, Germany. Both klystrons operate at the design power, 60 Hz repetition rate, 3 {micro}s pulsewidth, with an efficiency {gt} 40%, and agreement between the experimental results and simulations is excellent. The 535 kV, 700 A electron gun was tested by constructing a solenoidal focused beam stick which identified a source of oscillation, subsequently engineered out of the klystron guns. Design of the beam stick and the two klystrons is discussed, along with observation and suppression of spurious oscillations. Differences in design and the resulting performance of the Klystrons is emphasized.

  17. Nematic quantum criticality in three-dimensional Fermi system with quadratic band touching

    E-Print Network [OSTI]

    Janssen, Lukas

    2015-01-01T23:59:59.000Z

    We construct and discuss the field theory for tensorial nematic order parameter coupled to gapless four-component fermions at the quadratic band touching point in three (spatial) dimensions. Within a properly formulated epsilon-expansion this theory is found to have a quantum critical point, which describes the (presumably continuous) transition from the semimetal into a (nematic) Mott insulator. The latter phase breaks the rotational, but not the time-reversal symmetry, and may be relevant to materials such as gray tin or mercury telluride at low temperatures. The critical point represents the simplest quantum analogue of the familiar classical isotropic-to-nematic transition in liquid crystals. The properties and the consequences of this quantum critical point are discussed.

  18. Nematic quantum criticality in three-dimensional Fermi system with quadratic band touching

    E-Print Network [OSTI]

    Lukas Janssen; Igor F. Herbut

    2015-03-13T23:59:59.000Z

    We construct and discuss the field theory for tensorial nematic order parameter coupled to gapless four-component fermions at the quadratic band touching point in three (spatial) dimensions. Within a properly formulated epsilon-expansion this theory is found to have a quantum critical point, which describes the (presumably continuous) transition from the semimetal into a (nematic) Mott insulator. The latter phase breaks the rotational, but not the time-reversal symmetry, and may be relevant to materials such as gray tin or mercury telluride at low temperatures. The critical point represents the simplest quantum analogue of the familiar classical isotropic-to-nematic transition in liquid crystals. The properties and the consequences of this quantum critical point are discussed.

  19. X-band EPR imaging as a tool for gradient dose reconstruction in irradiated bones

    SciTech Connect (OSTI)

    Leveque, Philippe; Godechal, Quentin; Bol, Anne; Trompier, Francois; Gallez, Bernard [Biomedical Magnetic Resonance Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium); Molecular Imaging and Experimental Radiotherapy Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium); Institut de Surete Nucleaire et de Radioprotection, F-92262 Fontenay-aux-Roses (France); Biomedical Magnetic Resonance Unit, Universite catholique de Louvain, B-1200 Brussels (Belgium)

    2009-09-15T23:59:59.000Z

    Purpose: Various tools are currently available for dose reconstruction in individuals after accidental exposure to ionizing radiation. Among the available biological analyses, Monte Carlo simulations, and biophysical methods, such as electron paramagnetic resonance (EPR), the latter has proved its usefulness for retrospective dosimetry. Although EPR spectroscopy is probably the most sensitive technique, it does not provide spatial dosimetric data. This information is, however, highly desirable when steep dose gradient irradiations are involved. The purpose of this work was to explore the possibilities of EPR imaging (EPRI) for spatial dose reconstruction in irradiated biological material. Methods: X-band EPRI was used to reconstruct ex vivo the relative dose distribution in human bone samples and hydroxyapatite phantoms after irradiation with brachytherapy seeds or x rays. Three situations were investigated: Homogeneous, stepwise gradient, and continuous gradient irradiation. Results: EPRI gave a faithful relative spin density distribution in bone samples and in hydroxyapatite phantoms. Measured dose ratios were in close agreement with the actual delivered dose ratios. EPRI was able to distinguish the dose gradients induced by two different sources ({sup 125}I and {sup 192}Ir). However, the measured spatial resolution of the system was 1.9 mm and this appeared to be a limiting factor. The method could be improved by using new signal postprocessing strategies. Conclusions: This study demonstrates that EPRI can be used to assess the regional relative dose distribution in irradiated bone samples. The method is currently applicable to ex vivo measurements of small size samples with low variation in tissue density but is likely to be adapted for in vivo application using L-band EPRI.

  20. GRB 110721A: PHOTOSPHERE 'DEATH LINE' AND THE PHYSICAL ORIGIN OF THE GRB BAND FUNCTION

    SciTech Connect (OSTI)

    Zhang Bing; Lu Ruijing; Liang Enwei [Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University, Nanning 530004 (China); Wu Xuefeng [Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210008 (China)

    2012-10-20T23:59:59.000Z

    The prompt emission spectra of gamma-ray bursts (GRBs) usually have a dominant component that is well described by a phenomenological Band function. The physical origin of this spectral component is debated. Although the traditional interpretation is synchrotron radiation of non-thermal electrons accelerated in internal shocks or magnetic dissipation regions, the growing trend within the community is to interpret this component as modified thermal emission from a dissipative photosphere of a GRB fireball. We analyze the time-dependent spectrum of GRB 110721A detected by the Fermi Gamma-Ray Burst Monitor and Large Area Telescope, and pay special attention to the rapid evolution of the peak energy E{sub p} . We define a 'death line' of thermally dominated dissipative photospheric emission in the E{sub p} -L plane, and show that E{sub p} of GRB 110721A at the earliest epoch has a very high E{sub p} {approx} 15 MeV that is beyond the 'death line'. Together with the finding that an additional 'shoulder' component exists in this burst that is consistent with a photospheric origin, we suggest that at least for some bursts, the Band component is not from a dissipative photosphere, but must invoke a non-thermal origin (e.g., synchrotron or inverse Compton) in the optically thin region of a GRB outflow. We also suggest that the rapid hard-to-soft spectral evolution is consistent with the quick discharge of magnetic energy in a magnetically dominated outflow in the optically thin region.

  1. Broad band energy distribution of ROSAT detected quasars II: Radio-quiet objects

    E-Print Network [OSTI]

    W. Yuan; W. Brinkmann; J. Siebert; W. Voges

    1998-05-04T23:59:59.000Z

    A database of radio-quiet quasars detected with ROSAT is presented containing 846 quasars seen in the All-Sky Survey and/or in pointed PSPC observations. About 70% of the objects have been detected in X-rays for the first time. We present the soft X-ray fluxes and spectra, if available. Using an optically selected subsample compiled from this database, we study the broad band properties of radio-quiet quasars with high statistical significance. We confirm that radio-quiet quasars have in general steeper soft X-ray spectra than radio-loud. The spectral differences persist to high redshifts. A spectral flattening with increasing redshift is confirmed up to redshift around 2, beyond which the spectral slopes seem to be independent of redshift. The spectral slopes of the ROSAT radio-quiet quasars at z>2.5 are consistent with those found for nearby quasars in the medium energy band (2-10keV), implying that the X-ray spectral evolution is not important. We show that there is, in a statistical sense, little or no excess absorption for most of the radio-quiet objects at z>2. The existence of a correlation between the X-ray luminosity and the luminosity at 2500A is confirmed. Individual objects show a large scatter from this correlation. The X-ray loudness alpha_ox appears to be independent of z, but the analyses indicate a slight increase of alpha_ox with optical luminosity. However, this behavior is likely not caused by physical properties inherent to the quasars but is the result of the intrinsic dispersion. Finally, we find a small fraction of objects which appear to be relatively `X-ray quiet' compared to the bulk of the other quasars.

  2. Proposal of a gigawatt-class L/Ku dual-band magnetically insulated transmission line oscillator

    SciTech Connect (OSTI)

    Ju, J.-C., E-mail: jujinchuan@126.com; Fan, Y.-W.; Shu, T.; Zhong, H.-H. [College of Optoelectronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2014-10-15T23:59:59.000Z

    We present a gigawatt (GW)-class magnetically insulated transmission line oscillator (MILO) which is capable of generating dual-band high power microwaves (HPMs). The proposed device, deriving from previously studied complex MILO and dual-frequency MILO, is designed to produce two HPMs in L-band and Ku-band, respectively. It is found in particle-in-cell (PIC) simulation that when the diode voltage is 610?kV, HPMs with frequencies of 1.72 GHz and 14.6?GHz can be achieved with powers of 3.3?GW and 2.4?GW, respectively. The corresponding total power conversion efficiency is approximately 12.8%. Power difference of the two generated HPMs is approximately 1.4?dB, and frequency difference of them reaches a level as high as ?10?dB.

  3. Engineering direct-indirect band gap transition in wurtzite GaAs nanowires through size and uniaxial strain

    E-Print Network [OSTI]

    Copple, Andrew; Peng, Xihong; 10.1063/1.4718026

    2012-01-01T23:59:59.000Z

    Electronic structures of wurtzite GaAs nanowires in the [0001] direction were studied using first-principles calculations. It was found that the band gap of GaAs nanowires experience a direct-to-indirect transition when the diameter of the nanowires is smaller than ~28 {\\AA}. For those thin GaAs nanowires with an indirect band gap, it was found that the gap can be tuned to be direct if a moderate external uniaxial strain is applied. Both tensile and compressive strain can trigger the indirect-to-direct gap transition. The critical strains for the gap-transition are determined by the energy crossover of two states in conduction bands.

  4. Investigation of Band-Offsets at Monolayer-Multilayer MoS2 Junctions by Scanning Photocurrent Microscopy

    E-Print Network [OSTI]

    Howell, Sarah L; Wu, Chung-Chiang; Chen, Kan-Sheng; Sangwan, Vinod K; Kang, Junmo; Marks, Tobin J; Hersam, Mark C; Lauhon, Lincoln J

    2015-01-01T23:59:59.000Z

    The thickness-dependent band structure of MoS2 implies that discontinuities in energy bands exist at the interface of monolayer (1L) and multilayer (ML) thin films. The characteristics of such heterojunctions are analyzed here using current versus voltage measurements, scanning photocurrent microscopy, and finite element simulations of charge carrier transport. Rectifying I-V curves are consistently observed between contacts on opposite sides of 1L-ML junctions, and a strong bias-dependent photocurrent is observed at the junction. Finite element device simulations with varying carrier concentrations and electron affinities show that a type II band alignment at single layer/multi-layer junctions reproduces both the rectifying electrical characteristics and the photocurrent response under bias. However, the zero-bias junction photocurrent and its energy dependence are not explained by conventional photovoltaic and photothermoelectric mechanisms, indicating the contributions of hot carriers.

  5. The 10 $?$m infrared band of silicate dust: A laboratory study comparing the aerosol and KBr pellet techniques

    E-Print Network [OSTI]

    A. Tamanai; H. Mutschke; J. Blum; G. Meeus

    2006-09-08T23:59:59.000Z

    The profile of the silicate 10 $\\mu$m IR band contains important information about the evolutional stage of dust in circumstellar environments and the possible ongoing process of planetesimal formation. In order to extract this information, the observed band profiles are compared with calculated or laboratory-measured absorption cross sections of amorphous and crystalline grains with different sizes and compositions. We present in this study the first laboratory measurements of the 10 $\\mu$m band profiles of nonembedded, i.e. free-flying, particles of amorphous and crystalline Mg$_2$SiO$_4$ (with two different particle shapes), amorphous and crystalline MgSiO$_3$, and crystalline olivine. We compare the spectra with those measured on embedded grains and discuss the potential of the new experimental method for comparison with observed spectra, as well as for future studies of agglomeration and surface manipulation of the grains.

  6. The 10 $\\mu$m infrared band of silicate dust: A laboratory study comparing the aerosol and KBr pellet techniques

    E-Print Network [OSTI]

    Tamanai, A; Blum, J; Meeus, G

    2006-01-01T23:59:59.000Z

    The profile of the silicate 10 $\\mu$m IR band contains important information about the evolutional stage of dust in circumstellar environments and the possible ongoing process of planetesimal formation. In order to extract this information, the observed band profiles are compared with calculated or laboratory-measured absorption cross sections of amorphous and crystalline grains with different sizes and compositions. We present in this study the first laboratory measurements of the 10 $\\mu$m band profiles of nonembedded, i.e. free-flying, particles of amorphous and crystalline Mg$_2$SiO$_4$ (with two different particle shapes), amorphous and crystalline MgSiO$_3$, and crystalline olivine. We compare the spectra with those measured on embedded grains and discuss the potential of the new experimental method for comparison with observed spectra, as well as for future studies of agglomeration and surface manipulation of the grains.

  7. Contribution of ankyrin-band 3 complexes to the organization and mechanical properties of the membrane skeleton of human erythrocyte

    SciTech Connect (OSTI)

    Shen, B.W. [Argonne National Lab., IL (United States). Biological and Medical Research Div.

    1995-02-01T23:59:59.000Z

    To understand the role of ankyrin-band 3 complexes in the organization of the spectrin-based membrane skeleton and its contribution to the mechanical properties of human erythrocytes, intact skeletons and single-layered skeleton leaflets were prepared from intact and physically sheared membrane ghosts, expanded in low salt buffer, and examined by transmission electron microscopy. While the structures of intact skeletons and single-layered skeleton leaflets shared many common features, including rigid junctional complexes of spectrin, actin, and band 4.1; short stretches ({approximately}50 {angstrom}) of flexible spectrin filaments; and globular masses of ankyrin-band 3 complexes situated close to the middle of the spectrin filaments, the definition of structural units in the intact skeleton is obscured by the superposition of the two layers. However, the spatial disposition of structural elements can be clearly defined in the images of the single-layered skeleton leaflets. Partially expanded skeletal leaflets contain conglomerates of ankyrin-band 3 complexes arranged in a circular or clove-leaf configuration that straddles multiple strands of thick spectrin cables, presumably reflecting the association of ankyrin-band 3 complexes on neighboring spectrin tetramers as well as the lateral association of the spectrin filaments. Hyperexpansion of the skeleton leaflets led to dissociation of the conglomerates of ankyrin-band 3 complexes, full-extension of the spectrin tetramers, and separation of the individual strands of spectrin tetramers. Clearly defined stands of spectrin tetramers in the hyperexpanded single-layered skeletal leaflets often contained two sets of globular protein masses that divided the spectrin tetramers into three segments of approximately equal length.

  8. Mott Insulator-Superfluid Transition in a Generalized Bose-Hubbard Model with Topologically Non-trivial Flat-Band

    E-Print Network [OSTI]

    Xing-Hai Zhang; Su-Peng Kou

    2012-05-30T23:59:59.000Z

    In this paper, we studied a generalized Bose-Hubbard model on a checkerboard lattice with topologically nontrivial flat-band. We used mean-field method to decouple the model Hamiltonian and obtained phase diagram by Landau theory of second-order phase transition. We further calculate the energy gap and the dispersion of quasi-particle or quasi-hole in Mott insulator state and found that in strong interaction limit the quasi-particles or the quasi-holes also have flat bands.

  9. Observation of an electron band above the Fermi level in FeTe?.??Se?.?? from in-situ surface doping

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zhang, P. [Chinese Academy of Sciences (CAS), Beijing (China); Gu, G. D. [Brookhaven National Lab. (BNL), Upton, NY (United States); Richard, P. [Chinese Academy of Sciences (CAS), Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Xu, N. [Chinese Academy of Sciences (CAS), Beijing (China); Paul Scherrer Inst. (PSI), Villigen (Switzerland); Xu, Y. -M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ma, J. [Chinese Academy of Sciences (CAS), Beijing (China); Qian, T. [Chinese Academy of Sciences (CAS), Beijing (China); Fedorov, A. V. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Denlinger, J. D. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ding, H. [Chinese Academy of Sciences (CAS), Beijing (China); Collaborative Innovation Center of Quantum Matter, Beijing (China)

    2014-10-27T23:59:59.000Z

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

  10. Curvature-induced D-band Raman scattering in folded graphene This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Curvature-induced D-band Raman scattering in folded graphene This article has been downloaded from.1088/0953-8984/22/33/334205 Curvature-induced D-band Raman scattering in folded graphene* Awnish K Gupta1 , Cristiano Nisoli2 , Paul E Micro-Raman scattering from folds in single-layer graphene sheets finds a D-band at the fold for both

  11. The 846 nm A' 32; +X 3Z; band system of jet-cooled V, Eileen M. Spain, Jane M. Behm,a) and Michael D. Morse

    E-Print Network [OSTI]

    Morse, Michael D.

    The 846 nm A' 32; +X 3Z; band system of jet-cooled V, Eileen M. Spain, Jane M. Behm,a) and Michael October 1991; accepted 4 November 1991) The 846 nm band system of jet-cooled 5'V2 has been recorded using resonant two-photon ionization spectroscopy, and is assigned as the A '38; +X `2; band system. Both the w

  12. A Fully Integrated Multi-Band Multi-Output Synthesizer with Wide-Locking-Range 1/3 Injection Locked Divider Utilizing Self-Injection Technique for Multi-Band Microwave Systems

    E-Print Network [OSTI]

    Lee, Sang Hun

    2012-10-19T23:59:59.000Z

    This dissertation reports the development of a new multi-band multi-output synthesizer, 1/2 dual-injection locked divider, 1/3 injection-locked divider with phase-tuning, and 1/3 injection-locked divider with self-injection using 0.18-micrometer...

  13. ARM: W-Band Scanning ARM Cloud Radar (W-SACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Widener, Kevin; Nelson, Dan; Bharadwaj, Nitin; Lindenmaier, Iosif [Andrei; Johnson, Karen

    W-Band Scanning ARM Cloud Radar (W-SACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  14. ARM: X-Band Scanning ARM Cloud Radar (XSACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Widener, Kevin; Nelson, Dan; Bharadwaj, Nitin; Lindenmaier, Iosif [Andrei; Johnson, Karen

    X-Band Scanning ARM Cloud Radar (XSACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  15. ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Hemispherical Sky RHI Scan (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Bharadwaj, Nitin; Widener, Kevin

    Ka-Band Scanning ARM Cloud Radar (KASACR) Hemispherical Sky RHI Scan (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  16. Energetics of the Nanocrystalline Titanium Dioxide/Aqueous Solution Interface: Approximate Conduction Band Edge Variations between H0 ) -10 and H-) +26

    E-Print Network [OSTI]

    Energetics of the Nanocrystalline Titanium Dioxide/Aqueous Solution Interface: Approximate). Here we report on the dependence of the conduction band edge energy of nanocrystalline titanium dioxide

  17. Two-dimensional plasmon in a surface-state band Tadaaki Nagao a,b,c,*, Torsten Hildebrandt d

    E-Print Network [OSTI]

    Hasegawa, Shuji

    Two-dimensional plasmon in a surface-state band Tadaaki Nagao a,b,c,*, Torsten Hildebrandt d well with the plasmon dispersion calculated from two-dimensional (2D) nearly free-electron theory. As hallmarked from these observations, we identify the measured loss as a longitudinal intraband 2D plasmon

  18. Calculation of semiconductor band gaps with the M06-L density functional Yan Zhao and Donald G. Truhlara

    E-Print Network [OSTI]

    Truhlar, Donald G

    2009 The performance of the M06-L density functional has been tested for band gaps in seven,13 that is designed for main group thermo- chemistry, transition metal bonding, thermochemical kinet- ics in group-4, group 3­5, and metal oxide semiconductors. In Sec. II, we describe the test sets

  19. Signature of a spin-up magnetar from multi-band afterglow rebrightening of GRB 100814A

    E-Print Network [OSTI]

    Yu, Y B; Wu, X F; Xu, M; Geng, J J

    2015-01-01T23:59:59.000Z

    In recent years, more and more gamma-ray bursts with late rebrightenings in multi-band afterglows unveil the late-time activities of the central engines. GRB 100814A is a special one among the well-sampled events, with complex temporal and spectral evolution. The single power-law shallow decay index of the optical light curve observed by GROND between 640 s and 10 ks is $\\alpha_{\\rm opt} = 0.57 \\pm 0.02$, which apparently conflicts with the simple external shock model expectation. Especially, there is a remarkable rebrightening in the optical to near infrared bands at late time, challenging the external shock model with synchrotron emission coming from the interaction of the blast wave with the surrounding interstellar medium. In this paper, we invoke a magnetar with spin evolution to explain the complex multi-band afterglow emission of GRB 100814A. The initial shallow decay phase in optical bands and the plateau in X-ray can be explained as due to energy injection from a spin-down magnetar. At late time, wit...

  20. Photovoltaic devices with low band gap polymers Eva Bundgaarda, Sean Shaheenb, David S. Ginleyb, Frederik C. Krebsa

    E-Print Network [OSTI]

    Photovoltaic devices with low band gap polymers Eva Bundgaarda, Sean Shaheenb, David S. Ginleyb, Colorado, USA Abstract Progress in organic photovoltaic devices has recently resulted in reported temperature, active area of the device and molecular weight of the polymer, on the photovoltaic response

  1. Band offsets of TiZnSnO/Si heterojunction determined by x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Sun, R. J.; Jiang, Q. J.; Yan, W. C.; Feng, L. S.; Lu, B.; Ye, Z. Z. [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Li, X. F. [Key Laboratory of Advanced Display and System Application, Ministry of Education, Shanghai University, Shanghai 200072 (China); Li, X. D. [Xinyi PV Products (Anhui) Holdings LTD, Xinyi PV Glass Industrial Zone, No. 2 Xinyi Road, ETDZ, Wuhu 241009 (China); Lu, J. G., E-mail: lujianguo@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Key Laboratory of Advanced Display and System Application, Ministry of Education, Shanghai University, Shanghai 200072 (China)

    2014-09-28T23:59:59.000Z

    X-ray photoelectron spectroscopy (XPS) was utilized to measure the valence band offset (?E{sub V}) of the TiZnSnO (TZTO)/Si heterojunction. TZTO films were deposited on Si (100) substrates using magnetron sputtering at room temperature. By using the Zn 2p{sub 3/2} and Sn 3d{sub 5/2} energy levels as references, the value of ?E{sub V} was calculated to be 2.69 ± 0.1 eV. Combining with the experimental optical energy band gap of 3.98 eV for TZTO extracted from the UV-vis transmittance spectrum, the conduction band offset (?E{sub C}) was deduced to be 0.17 ± 0.1 eV at the interface. Hence, the energy band alignment of the heterojunction was determined accurately, showing a type-I form. This will be beneficial for the design and application of TZTO/Si hybrid devices.

  2. Discontinuous Non-Rigid Motion Analysis of Sea Ice using C-Band Synthetic Aperture Radar Satellite Imagery

    E-Print Network [OSTI]

    Delaware, University of

    Discontinuous Non-Rigid Motion Analysis of Sea Ice using C-Band Synthetic Aperture Radar Satellite@cis.udel.edu Cathleen Geiger Snow and Ice Branch USACRREL 72 Lyme Rd, Hanover, NH 03755 cathleen@cis.udel.edu Abstract Sea-ice motion consists of complex non-rigid motions in- volving continuous, piece-wise continuous

  3. Multipole-cancellation mechanism for high-Q cavities in the absence of a complete photonic band gap

    E-Print Network [OSTI]

    Multipole-cancellation mechanism for high-Q cavities in the absence of a complete photonic band gap in the lowest-order term s of the multipole far-field radiation expansion. We focus on the system of photonic-order term s in a multipole expansion of the far-field radiation, distinct from the near- field multipole

  4. Development of the Solid State X-band Radar and the Phased Array Radar System in Japan

    E-Print Network [OSTI]

    Droegemeier, Kelvin K.

    Development of the Solid State X-band Radar and the Phased Array Radar System in Japan By DR. TOMOO array radar system have been developed. Toshiba has developed the latest model of weather radar of precipitation and to achieve drastic reduction of its size and life cycle cost. It is now well known

  5. Molecular beam epitaxy of n-type ZnS: A wide band gap emitter for heterojunction PV devices

    E-Print Network [OSTI]

    Atwater, Harry

    Molecular beam epitaxy of n-type ZnS: A wide band gap emitter for heterojunction PV devices Jeffrey and AZO transparent conductive oxides did not. Applications to novel PV devices incorporating low electron-ray diffraction, zinc compounds. I. INTRODUCTION The growing interest in scalable, thin-film photovoltaics (PV

  6. InAs/InAsSb strain balanced superlattices for optical detectors: Material properties and energy band simulations

    E-Print Network [OSTI]

    Krishna, Sanjay

    InAs/InAsSb strain balanced superlattices for optical detectors: Material properties and energyAs/InAsSb strain balanced superlattices for optical detectors: Material properties and energy band simulations D February 2012) InAsSb/InAs type II strain balanced superlattices lattice matched to GaSb have recently been

  7. Band-gap grading in Cu(In,Ga)Se2 solar cells M. Gloeckler and J. R. Sites

    E-Print Network [OSTI]

    Sites, James R.

    Band-gap grading in Cu(In,Ga)Se2 solar cells M. Gloeckler and J. R. Sites Department of Physics solar cells, and some researchers have asserted that these fields can enhance performance to show that (1) there can be a beneficial effect of grading, (2) in standard thick- ness CIGS cells

  8. TABLE OF MAGNETIC-ROTATIONAL DIPOLE (SHEARS) BANDS Department of Physics, R.B. S. College, Agra 282002, India

    E-Print Network [OSTI]

    Ohta, Shigemi

    (ENSDF) database at Brookhaven) to each of the energy levels. Band Intensity The quoted value, when of Technology, Roorkee ­ 247667, India The table presents experimental data (extracted from recent publications contains gamma-ray energies, associated level energies with spins and parities, level lifetimes, B(M1

  9. Quasi-zero lattice mismatch and band alignment of BaTiO{sub 3} on epitaxial (110)Ge

    SciTech Connect (OSTI)

    Hudait, M. K.; Zhu, Y.; Jain, N. [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Maurya, D.; Zhou, Y.; Priya, S [Center for Energy Harvesting Materials and Systems (CEHMS), Virginia Tech, Blacksburg, Virginia 24061 (United States)

    2013-07-14T23:59:59.000Z

    Growth, structural, and band alignment properties of pulsed laser deposited amorphous BaTiO{sub 3} on epitaxial molecular beam epitaxy grown (110)Ge layer, as well as their utilization in low power transistor are reported. High-resolution x-ray diffraction demonstrated quasi-zero lattice mismatch of BaTiO{sub 3} on (110)Ge. Cross-sectional transmission electron microscopy micrograph confirms the amorphous nature of BaTiO{sub 3} layer as well as shows a sharp heterointerface between BaTiO{sub 3} and Ge with no traceable interfacial layer. The valence band offset, {Delta}E{sub v}, of 1.99 {+-} 0.05 eV at the BaTiO{sub 3}/(110)Ge heterointerface is measured using x-ray photoelectron spectroscopy. The conduction band offset, {Delta}E{sub c}, of 1.14 {+-} 0.1 eV is calculated using the bandgap energies of BaTiO{sub 3} of 3.8 eV and Ge of 0.67 eV. These band offset parameters for carrier confinement and the interface chemical properties of the BaTiO{sub 3}/(110)Ge system are significant advancement towards designing Ge-based p-and n-channel metal-oxide semiconductor field-effect transistors for low-power application.

  10. with transmission zeros near the passband are obtained. This dual band BPF shows the advantages including size and loss reduction

    E-Print Network [OSTI]

    Lee, Jong Duk

    -wide band (UWB); low noise amplifier (LNA);, Zeland Software, Fremont, CA, 1997. © 2008 Wiley Periodicals, Inc. LOW POWER SIZE-EFFICIENT CMOS UWB LOW-NOISE AMPLIFIER DESIGN Hee-Sauk Jhon, Ickhyun Song, Jongwook Jeon, MinSuk Koo, Byung-Gook Park, Jong Duk Lee

  11. Elastic and viscoelastic effects in rubber/air acoustic band gap structures: A theoretical and experimental study

    E-Print Network [OSTI]

    Deymier, Pierre

    Elastic and viscoelastic effects in rubber/air acoustic band gap structures: A theoretical rubber/air phononic crystal structures is investigated theoretically and experimentally. We introduce in a solid rubber matrix, as well as an array of rubber cylinders in an air matrix, are shown to behave

  12. Contr. Mineral. and Petrol. 12, 223--244 (1966) Staurolite-Quartzite Bands in Kyanite Quartzite at Big Rock,

    E-Print Network [OSTI]

    Lee, Cin-Ty Aeolus

    1966-01-01T23:59:59.000Z

    Contr. Mineral. and Petrol. 12, 223--244 (1966) Staurolite-Quartzite Bands in Kyanite Quartzite. Mineral.and Petrol., Vol.12 16 #12;224 W. SoH~Y~ and G. A. CHI~ER: Introduction In August 1958 one

  13. Simultaneous description of low-lying positive and negative parity bands in heavy even-even nuclei

    E-Print Network [OSTI]

    H. G. Ganev

    2014-09-05T23:59:59.000Z

    The low-lying spectra including the first few excited positive and negative parity bands of some heavy even-even nuclei from the rare earth and actinide mass regions are investigated within the framework of the symplectic Interacting Vector Boson Model with Sp(12,$R$) dynamical symmetry group. Symplectic dynamical symmetries allow the change of the number of excitation quanta or phonons building the collective states providing for larger representation spaces and richer subalgebraic structures to incorporate more complex nuclear spectra. The theoretical predictions for the energy levels and the electromagnetic transitions between the collective states of the ground state band and $K^{\\pi}=0^{-}$ band are compared with experiment and some other collective models incorporating octupole and/or dipole degrees of freedom. The energy staggering which is a sensitive indicator of the octupole correlations in the even-even nuclei is also calculated and compared with experiment. The results obtained for the energy levels, energy staggering and transition strengths reveal the relevance of the used dynamical symmetry of the model for the simultaneous description of both positive and negative parity low-lying collective bands.

  14. 1004 OPTICS LETTERS / Vol. 23, No. 13 / July 1, 1998 1.5-mm-band wavelength conversion based on

    E-Print Network [OSTI]

    Fejer, Martin M.

    telecommunications band based on difference-frequency generation in periodically poled lithium niobate waveguides converters was proposed.3 That architecture, exploiting the unique properties of DFG-based wavelengthGaAs) or limited homogeneous interaction lengths (in LiNbO3). Another critical issue with guided-wave DFG

  15. Compact Electrothermal Modeling of an X-band MMIC Sonali Luniya William Batty Vincent Caccamesi Mikael Garcia Carlos Christoffersen

    E-Print Network [OSTI]

    Davis, Rhett

    must be captured at the period of the carrier signals or at least at the envelope rate. Thermal of lumped electrical devices and compact thermal modeling of volu- metric materials enables efficient electrothermal modeling of microwave circuits. The compact thermal model of the body of an X-band MMIC is based

  16. Optical bistability and phase transitions in a doped photonic band-gap material Sajeev John and Tran Quang

    E-Print Network [OSTI]

    John, Sajeev

    in a pseudophotonic band gap PBG to an applied laser field. It is shown that in the case when the variance of resonant reactive ion etching techniques. The relative dif- ficulty in drilling to a depth of more than a few unit

  17. Ultra-high-frequency chaos in a time-delay electronic device with band-limited feedback

    E-Print Network [OSTI]

    Illing, Lucas

    Ultra-high-frequency chaos in a time-delay electronic device with band-limited feedback Lucas- dynamical electronic device. It consists of a transistor-based nonlinearity, commercially of such a device, we explore the dynamics of an electronic circuit that consists of a simple transistor

  18. Highly efficient Nd:YVO4 laser by direct in-band diode pumping at 914 nm

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Highly efficient Nd:YVO4 laser by direct in-band diode pumping at 914 nm Damien Sangla,1,2 Marc (Doc. ID 109884); published July 9, 2009 A Nd:YVO4 crystal was pumped directly into the emitting level nm for an absorbed pump power of 14.6 W, corresponding to an optical efficiency of 78.7%. We

  19. Here, we present the fabrication and use of plastic Photonic Band Gap Bragg fibres in photonic textiles for applications in

    E-Print Network [OSTI]

    Skorobogatiy, Maksim

    Here, we present the fabrication and use of plastic Photonic Band Gap Bragg fibres in photonic­section, Bragg fibres feature periodic sequence of layers of two distinct plastics. Under ambient illumination SCHICKER2 , NING GUO1 , CHARLES DUBOIS3 , RACHEL WINGFIELD2 & MAKSIM SKOROBOGATIY1 COLOUR-ON-DEMAND

  20. 480 IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 12, NO. 5, MAY 2000 Coupled Structure for Wide-Band EDFA with Gain

    E-Print Network [OSTI]

    Park, Namkyoo

    480 IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 12, NO. 5, MAY 2000 Coupled Structure for Wide applications due to the maturity of the supporting technologies such as the host material and pump sources-band EDFA's [4], [5], we have suggested a structure that recycles useless backward amplified spontaneous

  1. THE JOURNAL OF CHEMICAL PHYSICS 141, 22D524 (2014) Infrared spectral marker bands characterizing a transient water wire inside

    E-Print Network [OSTI]

    Gerwert, Klaus

    2014-01-01T23:59:59.000Z

    molecules distributed at inactive positions in a polar environment in the ground state. The movement properties. These band shifts are identified by time-resolved Fourier Transform Infrared difference surface to the proteins' active sites, or through the protein core across a membrane, in di- rectional

  2. Negative capacitance in GaN/AlGaN heterojunction dual-band detectors L. E. Byrum,1

    E-Print Network [OSTI]

    Dietz, Nikolaus

    Negative capacitance in GaN/AlGaN heterojunction dual-band detectors L. E. Byrum,1 G. Ariyawansa,1 online 2 September 2009 A study of trap states in n+ -GaN/AlGaN heterostructures using electrical related absorption centers attributed to shallow Si-donor pinned to the AlGaN barrier , N-vacancy/ C

  3. Band gap tuning in GaN through equibiaxial in-plane strains S. K. Yadav,2

    E-Print Network [OSTI]

    Alpay, S. Pamir

    in photovoltaics and light emission diodes LEDs . The InGaN system has been intensively studied during the past to the large atomic size mismatch between Ga and In.3 Thus, other methods to tune the band gap are needed for potential appli- cations of GaN and related materials systems. It is well-known that the structure

  4. Federal Communications Commission US311 Radio astronomy observations may be made in the bands 13501400 MHz and 49504990 MHz

    E-Print Network [OSTI]

    Bower, Geoffrey

    Federal Communications Commission 162 US311 Radio astronomy observations may be made in the bands and between longitudes 120° 15' W and 122° 15' W. NASA Goldstone Deep Space Communications Complex, Goldstone and safety communications, e.g., GMDSS, shall have priority access with real­time preemptive capability

  5. Liquid phase epitaxial growth and characterization of germanium far infrared blocked impurity band detectors

    SciTech Connect (OSTI)

    Bandaru, Jordana

    2001-05-12T23:59:59.000Z

    Germanium Blocked Impurity Band (BIB) detectors require a high purity blocking layer (< 10{sup 13} cm{sup -3}) approximately 1 mm thick grown on a heavily doped active layer ({approx} 10{sup 16} cm{sup -3}) approximately 20 mm thick. Epilayers were grown using liquid phase epitaxy (LPE) of germanium out of lead solution. The effects of the crystallographic orientation of the germanium substrate on LPE growth modes were explored. Growth was studied on substrates oriented by Laue x-ray diffraction between 0.02{sup o} and 10{sup o} from the {l_brace}111{r_brace} toward the {l_brace}100{r_brace}. Terrace growth was observed, with increasing terrace height for larger misorientation angles. It was found that the purity of the blocking layer was limited by the presence of phosphorus in the lead solvent. Unintentionally doped Ge layers contained {approx}10{sup 15} cm{sup -3} phosphorus as determined by Hall effect measurements and Photothermal Ionization Spectroscopy (PTIS). Lead purification by vacuum distillation and dilution reduced the phosphorus concentration in the layers to {approx} 10{sup 14} cm{sup -3} but further reduction was not observed with successive distillation runs. The graphite distillation and growth components as an additional phosphorus source cannot be ruled out. Antimony ({approx}10{sup 16} cm{sup -3}) was used as a dopant for the active BIB layer. A reduction in the donor binding energy due to impurity banding was observed by variable temperature Hall effect measurements. A BIB detector fabricated from an Sb-doped Ge layer grown on a pure substrate showed a low energy photoconductive onset ({approx}6 meV). Spreading resistance measurements on doped layers revealed a nonuniform dopant distribution with Sb pile-up at the layer surface, which must be removed by chemomechanical polishing. Sb diffusion into the pure substrate was observed by Secondary Ion Mass Spectroscopy (SIMS) for epilayers grown at 650 C. The Sb concentration at the interface dropped by an order of magnitude over {approx} 1.5 {micro}m. Layers grown at 550 C did not show significant Sb diffusion. Sn doped In{sub 2}O{sub 3} (ITO) was studied for use in far infrared transparent low temperature contacts for BIB arrays. It was found that {approx}100 nm of ITO deposited on Ge remains electrically conducting at 4 K and is {approx}90% transparent in the far infrared. ITO should be suitable for passivating contacts to Ge BIB arrays.

  6. A Low-Charge, Hard X-Ray FEL Driven with an X-band Injector and Accelerator

    SciTech Connect (OSTI)

    Sun, Yipeng; Adolphsen, Chris; Limborg-Deprey, Cecile; Raubenheimer, Tor; Wu, Juhao; /SLAC

    2012-02-17T23:59:59.000Z

    After the successful operation of FLASH (Free-Electron Laser in Hamburg) and LCLS (Linac Coherent Light Source), soft and hard X-ray Free Electron Lasers (FELs) are being built, designed or proposed at many accelerator laboratories. Acceleration employing lower frequency RF cavities, ranging from L-band to C-band, is usually adopted in these designs. In the first stage bunch compression, higher-frequency harmonic RF system is employed to linearize the beam's longitudinal phase space, which is nonlinearly chirped during the lower frequency RF acceleration process. In this paper, a hard X-ray FEL design using an all X-band accelerator at 11.424 GHz (from photo-cathode RF gun to linac end) is presented, without the assistance of any harmonic RF linearization. It achieves LCLS-like performance at low charge using X-band linac drivers, which is more versatile, efficient and compact than ones using S-band or C-band rf technology. It employs initially 42 microns long (RMS), low charge (10 pC) electron bunches from an X-band photoinjector. An overall bunch compression ratio of roughly 100 times is proposed in a two stage bunch compressor system. The start-to-end macro-particle 3-D simulation employing several computer codes is presented in this paper, where space charge, wakefields, incoherent and coherent synchrotron radiation (ISR and CSR) effects are included. Employing an undulator with a short period of 1.5 cm, a Genesis FEL simulation shows successful lasing at a wavelength of 0.15 nm with a pulse length of 2 fs and a power saturation length as short as 20 meters, which is equivalent to LCLS low charge mode. Its overall length of both accelerators and undulators is 180 meters (much shorter than the effective LCLS overall length of 1230 meters, including an accelerator length of 1100 meters and an undulator length of 130 meters), which makes it possible to be built in places where only limited space is available.

  7. Low-Charge, Hard X-Ray Free Electron Laser Driven with an X-Band Injector and Accelerator

    SciTech Connect (OSTI)

    Sun, Yipeng; Adolphsen, Chris; Limborg-Deprey, Cecile; Raubenheimer, Tor; Wu, Juhao; /SLAC

    2012-04-17T23:59:59.000Z

    After the successful operation of the Free Electron Laser in Hamburg (FLASH) and the Linac Coherent Light Source (LCLS), soft and hard x-ray free electron lasers (FELs) are being built, designed, or proposed at many accelerator laboratories. Acceleration employing lower frequency rf cavities, ranging from L-band to C-band, is usually adopted in these designs. In the first stage bunch compression, higher-frequency harmonic rf system is employed to linearize the beam's longitudinal phase space, which is nonlinearly chirped during the lower frequency rf acceleration process. In this paper, a hard x-ray FEL design using an all X-band accelerator at 11.424 GHz (from photocathode rf gun to linac end) is presented, without the assistance of any harmonic rf linearization. It achieves LCLS-like performance at low charge using X-band linac drivers, which is more versatile, efficient, and compact than ones using S-band or C-band rf technology. It employs initially 42 microns long (rms), low-charge (10 pC) electron bunches from an X-band photoinjector. An overall bunch compression ratio of roughly 100 times is proposed in a two stage bunch compressor system. The start-to-end macroparticle 3D simulation employing several computer codes is presented in this paper, where space charge, wakefields, and incoherent and coherent synchrotron radiation effects are included. Employing an undulator with a short period of 1.5 cm, a Genesis FEL simulation shows successful lasing at a wavelength of 0.15 nm with a pulse length of 2 fs and a power saturation length as short as 20 meters, which is equivalent to LCLS low-charge mode. Its overall length of both accelerators and undulators is 180 meters (much shorter than the effective LCLS overall length of 1230 meters, including an accelerator length of 1100 meters and an undulator length of 130 meters), which makes it possible to be built in places where only limited space is available.

  8. Power Spectra in V-band and Halpha of Nine Irregular Galaxies

    E-Print Network [OSTI]

    Kyle W. Willett; Bruce G. Elmegreen; Deidre A. Hunter

    2005-03-14T23:59:59.000Z

    Fourier transform power spectra of major axis cuts in V and Halpha images were made for a sample of 9 irregular galaxies. These power spectra reveal structure over a wide range of scales. For 6 of the galaxies the power spectrum slopes at intermediate scales (1-400 pc) in the V-band images range from -1.3 to -1.5. The similarity of slopes suggests that the same processes are structuring these systems. These slopes are slightly shallower than what is observed in other galaxies in HI, molecular emission, dust extinction, and optical light. Three of the galaxies have flat power spectra like noise from the sky; these three galaxies are relatively indistinct in the direct images. The power spectrum slope for Halpha steepens with increasing star formation rate, ranging from a shallow value comparable to the noise at low rates to a steep value with a slope of -1.5 at high rates. This change reflects the increasing areal filling factor of Halpha emission with increasing star formation rate, and an apparently universal slope inside the Halpha regions that is comparable to that for Kolmogorov turbulence. The power spectrum of HI in one galaxy has a steeper power law, with a slope of -2.9. The fact that the power laws of star formation are about the same for dwarf galaxies and giant spiral galaxies suggests the microscopic processes are the same, independent of spiral density waves and galaxy size.

  9. Hopf bifurcations in time-delay systems with band-limited feedback

    E-Print Network [OSTI]

    Lucas Illing; Daniel J. Gauthier

    2005-07-20T23:59:59.000Z

    We investigate the steady-state solution and its bifurcations in time-delay systems with band-limited feedback. This is a first step in a rigorous study concerning the effects of AC-coupled components in nonlinear devices with time-delayed feedback. We show that the steady state is globally stable for small feedback gain and that local stability is lost, generically, through a Hopf bifurcation for larger feedback gain. We provide simple criteria that determine whether the Hopf bifurcation is supercritical or subcritical based on the knowledge of the first three terms in the Taylor-expansion of the nonlinearity. Furthermore, the presence of double-Hopf bifurcations of the steady state is shown, which indicates possible quasiperiodic and chaotic dynamics in these systems. As a result of this investigation, we find that AC-coupling introduces fundamental differences to systems of Ikeda-type [Ikeda et al., Physica D 29 (1987) 223-235] already at the level of steady-state bifurcations, e.g. bifurcations exist in which limit cycles are created with periods other than the fundamental ``period-2'' mode found in Ikeda-type systems.

  10. Galaxy formation at z > 3 revealed by narrow-band selected [OIII] emission line galaxies

    E-Print Network [OSTI]

    Suzuki, Tomoko L; Tadaki, Ken-ichi; Hayashi, Masao; Koyama, Yusei; Tanaka, Ichi; Minowa, Yosuke; Shimakawa, Rhythm; Yamamoto, Moegi

    2015-01-01T23:59:59.000Z

    We present the physical properties of [OIII] emission line galaxies at z>3 as the tracers of active galaxies at 1Gyr before the peak epoch at z~2. We have performed deep narrow-band imaging surveys in the Subaru/XMM-Newton Deep Survey Field with MOIRCS on the Subaru Telescope and have constructed coherent samples of 34 [OIII] emitters at z=3.2 and 3.6, as well as 107 H$\\alpha$ emitters at z=2.2 and 2.5. We investigate their basic physical quantities, such as stellar masses, star formation rates (SFRs), and sizes using the publicly available multi-wavelength data and high resolution images by the Hubble Space Telescope. The stellar masses and SFRs show a clear correlation known as the "main sequence" of star-forming galaxies. It is found that the location of the main sequence of the [OIII] emitters at z=3.2 and 3.6 is almost identical to that of the H$\\alpha$ emitters at z=2.2 and 2.5. Also, we investigate their mass-size relation and find that the relation does not change between the two epochs. When we assum...

  11. Advanced X-Band Test Accelerator for High Brightness Electron and Gamma Ray Beams

    SciTech Connect (OSTI)

    Marsh, Roark; /LLNL, Livermore; Anderson, Scott; /LLNL, Livermore; Barty, Christopher; /LLNL, Livermore; Chu, Tak Sum; /LLNL, Livermore; Ebbers, Chris; /LLNL, Livermore; Gibson, David; /LLNL, Livermore; Hartemann, Fred; /LLNL, Livermore; Adolphsen, Chris; /SLAC; Jongewaard, Erik; /SLAC; Raubenheimer, Tor; /SLAC; Tantawi, Sami; /SLAC; Vlieks, Arnold; /SLAC; Wang, Juwen; /SLAC

    2012-07-03T23:59:59.000Z

    In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

  12. ADVANCED X-BAND TEST ACCELERATOR FOR HIGH BRIGHTNESS ELECTRON AND GAMMA RAY BEAMS

    SciTech Connect (OSTI)

    Marsh, R A; Anderson, S G; Barty, C P; Chu, T S; Ebbers, C A; Gibson, D J; Hartemann, F V; Adolphsen, C; Jongewaard, E N; Raubenheimer, T; Tantawi, S G; Vlieks, A E; Wang, J W

    2010-05-12T23:59:59.000Z

    In support of Compton scattering gamma-ray source efforts at LLNL, a multi-bunch test stand is being developed to investigate accelerator optimization for future upgrades. This test stand will enable work to explore the science and technology paths required to boost the current 10 Hz monoenergetic gamma-ray (MEGa-Ray) technology to an effective repetition rate exceeding 1 kHz, potentially increasing the average gamma-ray brightness by two orders of magnitude. Multiple bunches must be of exceedingly high quality to produce narrow-bandwidth gamma-rays. Modeling efforts will be presented, along with plans for a multi-bunch test stand at LLNL. The test stand will consist of a 5.5 cell X-band rf photoinjector, single accelerator section, and beam diagnostics. The photoinjector will be a high gradient standing wave structure, featuring a dual feed racetrack coupler. The accelerator will increase the electron energy so that the emittance can be measured using quadrupole scanning techniques. Multi-bunch diagnostics will be developed so that the beam quality can be measured and compared with theory. Design will be presented with modeling simulations, and layout plans.

  13. C-Band All-Sky Survey: A First Look at the Galaxy

    E-Print Network [OSTI]

    Irfan, M O; Davies, R D; Copley, C; Davis, R J; Ferreira, P G; Holler, C M; Jonas, J L; Jones, Michael E; King, O G; Leahy, J P; Leech, J; Leitch, E M; Muchovej, S J C; Pearson, T J; Peel, M W; Readhead, A C S; Stevenson, M A; Sutton, D; Taylor, Angela C; Zuntz, J

    2015-01-01T23:59:59.000Z

    We present an analysis of the diffuse emission at 5 GHz in the first quadrant of the Galactic plane using two months of preliminary intensity data taken with the C-Band All Sky Survey (C-BASS) northern instrument at the Owens Valley Radio Observatory, California. Combining C-BASS maps with ancillary data to make temperature-temperature plots we find synchrotron spectral indices of $\\beta = -2.65 \\pm 0.05$ between 0.408 GHz and 5 GHz and $ \\beta = -2.72 \\pm 0.09$ between 1.420 GHz and 5 GHz for $-10^{\\circ} template we determine the synchrotron spectral index in the Galactic plane ($ |b| < 4^{\\circ}$) to be $\\beta = -2.56 \\pm 0.07$ between 0.408 GHz and 5 GHz, with a contribution of $53 \\pm 8$ per cent from free-free emission at 5\\,GHz. These results are consistent with previous low frequency measurements in the Galactic plane. By including C-BASS data in spectral fits we dem...

  14. The Landauer Resistance and Band Spectra for the Counting Quantum Turing Machine

    E-Print Network [OSTI]

    Paul Benioff

    1997-02-07T23:59:59.000Z

    The generalized counting quantum Turing machine (GCQTM) is a machine which, for any N, enumerates the first $2^{N}$ integers in succession as binary strings. The generalization consists of associating a potential with read-1 steps only. The Landauer Resistance (LR) and band spectra were determined for the tight binding Hamiltonians associated with the GCQTM for energies both above and below the potential height. For parameters and potentials in the electron region, the LR fluctuates rapidly between very high and very low values as a function of momentum. The rapidity and extent of the fluctuations increases rapidly with increasing N. For N=18, the largest value considered, the LR shows good transmission probability as a function of momentum with numerous holes of very high LR values present. This is true for energies above and below the potential height. It is suggested that the main features of the LR can be explained by coherent superposition of the component waves reflected from or transmitted through the $2^{N-1}$ potentials in the distribution. If this explanation is correct, it provides a dramatic illustration of the effects of quantum nonlocality.

  15. The Landauer resistance and band spectra for the counting quantum Turing machine

    SciTech Connect (OSTI)

    Benioff, P.

    1996-12-31T23:59:59.000Z

    In other work, the generalized counting quantum Turing machine (GCQTM) was studied. For any N this machine enumerates the first 2{sup N} integers in succession as binary strings. The generalization consists of associating a potential with read 1 steps only. The Landauer Resistance (LR) and band spectra were determined for the tight binding Hamiltonians associated with the GCQTM for energies below the potential height. Here these calculations are extended to energies both above and below the barrier height. For parameters and potentials in the electron region, the LR fluctuates rapidly between very high and very low values as a function of momentum. The rapidity and extent of the fluctuations increases rapidly with increasing N. For N = 18, the largest value considered, the LR shows good transmission probability as a function of momentum with numerous holes of very high LR values present. This is true for energies both above and below the potential height. It is suggested that the main features of the LR can be explained by coherent superposition of the component waves reflected from or transmitted through or across the 2{sup N-1} potentials present in the distribution. If this explanation is correct, it provides a dramatic illustration of the effects of quantum nonlocality.

  16. A theoretical and experimental study of pressure broadening of the oxygen A-band by helium

    SciTech Connect (OSTI)

    Grimminck, Dennis L. A. G.; Spiering, Frans R.; Janssen, Liesbeth M. C.; Avoird, Ad van der; Zande, Wim J. van der; Groenenboom, Gerrit C., E-mail: Gerritg@theochem.ru.nl [Institute for Molecules and Materials, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen (Netherlands)

    2014-05-28T23:59:59.000Z

    The rotationally resolved magnetic dipole absorption spectrum of the oxygen A-band b{sup 1}?{sub g}{sup +}(v=0)?X{sup 3}?{sub g}{sup ?}(v=0) perturbed by collisions with helium was studied theoretically using the impact approximation. To calculate the relaxation matrix, scattering calculations were performed on a newly computed helium-oxygen (b{sup 1}?{sub g}{sup +}) interaction potential as well as on a helium-oxygen (X{sup 3}?{sub g}{sup ?}) interaction potential from the literature. The calculated integrated line cross sections and broadening coefficients are in good agreement with experimental results from the literature. Additionally, cavity ring-down experiments were performed in the wings of the spectral lines for a quantitative study of line-mixing, i.e., the redistribution of rotational line intensities by helium-oxygen collisions. It is shown that inclusion of line-mixing in the theory is required to reproduce the experimentally determined absolute absorption strengths as a function of the density of the helium gas.

  17. Method for implantation of high dopant concentrations in wide band gap materials

    DOE Patents [OSTI]

    Usov, Igor (Los Alamos, NM); Arendt, Paul N. (Los Alamos, NM)

    2009-09-15T23:59:59.000Z

    A method that combines alternate low/medium ion dose implantation with rapid thermal annealing at relatively low temperatures. At least one dopant is implanted in one of a single crystal and an epitaxial film of the wide band gap compound by a plurality of implantation cycles. The number of implantation cycles is sufficient to implant a predetermined concentration of the dopant in one of the single crystal and the epitaxial film. Each of the implantation cycles includes the steps of: implanting a portion of the predetermined concentration of the one dopant in one of the single crystal and the epitaxial film; annealing one of the single crystal and the epitaxial film and implanted portion at a predetermined temperature for a predetermined time to repair damage to one of the single crystal and the epitaxial film caused by implantation and activates the implanted dopant; and cooling the annealed single crystal and implanted portion to a temperature of less than about 100.degree. C. This combination produces high concentrations of dopants, while minimizing the defect concentration.

  18. Multi-band optical-NIR variability of blazars on diverse timescales

    E-Print Network [OSTI]

    Agarwal, Aditi; Bachev, R; Strigachev, A; Semkov, E; Wiita, Paul J; Bottcher, M; Boeva, S; Gaur, H; Gu, M F; Peneva, S; Ibryamov, S; Pandey, U S

    2015-01-01T23:59:59.000Z

    To search for optical variability on a wide range of timescales, we have carried out photometric monitoring of two flat spectrum radio quasars, 3C 454.3 and 3C 279, plus one BL Lac, S5 0716+714, all of which have been exhibiting remarkably high activity and pronounced variability at all wavelengths. CCD magnitudes in B, V, R and I pass-bands were determined for $\\sim$ 7000 new optical observations from 114 nights made during 2011 - 2014, with an average length of $\\sim$ 4 h each, at seven optical telescopes: four in Bulgaria, one in Greece, and two in India. We measured multiband optical flux and colour variations on diverse timescales. Discrete correlation functions were computed among B, V, R, and I observations, to search for any time delays. We found weak correlations in some cases with no significant time lags. The structure function method was used to estimate any characteristic time-scales of variability. We also investigated the spectral energy distribution of the three blazars using B, V, R, I, J and...

  19. Sodium and Oxygen Abundances in the Open Cluster NGC 6791 from APOGEE H-Band Spectroscopy

    E-Print Network [OSTI]

    Cunha, Katia; Johnson, Jennifer A; Bergemann, Maria; Meszaros, Szabolcs; Shetrone, Matthew D; Souto, Diogo; Prieto, Carlos Allende; Schiavon, Ricardo P; Frinchaboy, Peter; Zasowski, Gail; Bizyaev, Dmitry; Holtzman, Jon; Perez, Ana E Garcia; Majewski, Steven R; Nidever, David; Beers, Timothy; Carrera, Ricardo; Geisler, Doug; Gunn, James; Hearty, Fred; Ivans, Inese; Martell, Sarah; Pinsonneault, Marc; Schneider, Donald P; Sobeck, Jennifer; Stello, Dennis; Stassun, Keivan G; Skrutskie, Michael; Wilson, John C

    2014-01-01T23:59:59.000Z

    The open cluster NGC 6791 is among the oldest, most massive and metal-rich open clusters in the Galaxy. High-resolution $H$-band spectra from the Apache Point Observatory Galactic Evolution Experiment (APOGEE) of 11 red giants in NGC 6791 are analyzed for their chemical abundances of iron, oxygen, and sodium. The abundances of these three elements are found to be homogeneous (with abundance dispersions at the level of $\\sim$ 0.05 - 0.07 dex) in these cluster red giants, which span much of the red-giant branch (T$_{\\rm eff}$ $\\sim$ 3500K - 4600K), and include two red-clump giants. From the infrared spectra, this cluster is confirmed to be among the most metal-rich clusters in the Galaxy ($$ = 0.34 $\\pm$ 0.06), and is found to have a roughly solar value of [O/Fe] and slightly enhanced [Na/Fe]. Non-LTE calculations for the studied Na I lines in the APOGEE spectral region ($\\lambda$16373.86\\AA\\ and $\\lambda$16388.85\\AA) indicate only small departures from LTE ($\\leq$ 0.04 dex) for the parameter range and metallic...

  20. New H-band Stellar Spectral Libraries for the SDSS-III/APOGEE survey

    E-Print Network [OSTI]

    Zamora, O; Prieto, C Allende; Carrera, R; Koesterke, L; Edvardsson, B; Castelli, F; Plez, B; Bizyaev, D; Cunha, K; Perez, A E Garcia; Gustafsson, B; Holtzman, J A; Lawler, J E; Majewski, S R; Manchado, A; Meszaros, Sz; Shane, N; Shetrone, M; Smith, V V; Zasowski, G

    2015-01-01T23:59:59.000Z

    The Sloan Digital Sky Survey--III (SDSS--III) Apache Point Observatory Galactic Evolution Experiment (APOGEE) has obtained high resolution (R $\\sim$ 22,500), high signal-to-noise ($>$ 100) spectra in the H$-$band spectral region ($\\sim$1.5$-$1.7 $\\mu$m) for about 146,000 stars in the Milky Way galaxy. We have computed specific spectral libraries with effective temperature ($T\\rm{_{eff}}$) ranging from 3500 to 8000 K for the automated chemical analysis of the survey data. The spectral libraries, used to derive stellar parameters and abundances from the APOGEE spectra in the SDSS--III data release 12 (DR12), are based on ATLAS9 model atmospheres and the ASS$\\epsilon$T spectral synthesis code. We present a second set of stellar spectral libraries based on MARCS model atmospheres and the spectral synthesis code Turbospectrum. The ATLAS9/ASS$\\epsilon$T ($T\\rm{_{eff}}$ = 3500$-$8000 K) and MARCS/Turbospectrum ($T\\rm{_{eff}}$ = 3500$-$5500 K) grids of synthetic spectra cover a wide range of metallicity ($-$2.5 $\\leq...