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Zinc oxyfluoride transparent conductor
Gordon, Roy G. (Cambridge, MA)
Transparent, electrically conductive and infrared-reflective films of zinc oxyfluoride are produced by chemical vapor deposition from vapor mixtures of zinc, oxygen and fluorine-containing compounds. The substitution of fluorine for some of the oxygen in zinc oxide results in dramatic increases in the electrical conductivity. For example, diethyl zinc, ethyl alcohol and hexafluoropropene vapors are reacted over a glass surface at 400.degree. C. to form a visibly transparent, electrically conductive, infrared reflective and ultraviolet absorptive film of zinc oxyfluoride. Such films are useful in liquid crystal display devices, solar cells, electrochromic absorbers and reflectors, energy-conserving heat mirrors, and antistatic coatings.
A comparison of graphene, superconductors and metals as conductors for metamaterials and plasmonics
Tassin, Philippe; Koschny, Thomas; Kafesaki, Maria; Soukoulis, Costas
Recent advancements in metamaterials and plasmonics have promised a number of exciting applications, in particular at terahertz and optical frequencies. Unfortunately, the noble metals used in these photonic structures are not particularly good conductors at high frequencies, resulting in significant dissipative loss. Here, we address the question of what is a good conductor for metamaterials and plasmonics. For resonant metamaterials, we develop a figure-of-merit for conductors that allows for a straightforward classification of conducting materials according to the resulting dissipative loss in the metamaterial. Application of our method predicts that graphene and high-T{sub c} superconductors are not viable alternatives for metals in metamaterials. We also provide an overview of a number of transition metals, alkali metals and transparent conducting oxides. For plasmonic systems, we predict that graphene and high-T{sub c} superconductors cannot outperform gold as a platform for surface plasmon polaritons, because graphene has a smaller propagation length-to-wavelength ratio.
Nanostructured Transparent Conductors Have Potential for Thin-Film Photovoltaics (Fact Sheet)
Not Available
Possible alternatives to transparent conductors show promise for enabling new processes and reducing costs.
Slow-light plasmonic metamaterial based on dressed-state analog of electromagnetically-induced transparency
Raza, S½ren
We consider a simple configuration for realizing one-dimensional slow-light metamaterials with large bandwidth-delay products using stub-shaped Fabry-Perot resonators as building blocks. Each metaatom gives rise to large group indices due to a classical analog of the dressed-state picture of electromagnetically-induced transparency. By connecting up to eight metaatoms, we find bandwidth-delay products over unity and group indices approaching 100. Our approach is quite general and can be applied to any type of Fabry-Perot resonators and tuned to different operating wavelengths.
Copper and Transparent-Conductor Reflectarray Elements on Thin-Film Solar Cell Panels
Dreyer, Philippe; Nicolay, Sylvain; Ballif, Christophe; Perruisseau-Carrier, Julien
This work addresses the integration of reflectarray antennas (RA) on thin film Solar Cell (SC) panels, as a mean to save real estate, weight, or cost in platforms such as satellites or transportable autonomous antenna systems. Our goal is to design a good RA unit cell in terms of phase response and bandwidth, while simultaneously achieving high optical transparency and low microwave loss, to preserve good SC and RA energy efficiencies, respectively. Since there is a trade-off between the optical transparency and microwave surface conductivity of a conductor, here both standard copper and transparent conductors are considered. The results obtained at the unit cell level demonstrates the feasibility of integrating RA on a thin-film SC, preserving for the first time good performance in terms of both SC and RA efficiency. For instance, measurement at X-band demonstrate families of cells providing a phase range larger than 270{\\deg} with average microwave loss of -2.45dB (resp. -0.25dB) and average optical transpa...
Remarkable Thermal Stability of Amorphous In-Zn-O Transparent Conductors
Taylor, M. P.; Readey, D. W.; van Hest, M. F. A. M.; Teplin, C. W.; Alleman, J. L.; Dabney, M. S.; Gedvilas, L. M.; Keyes, B. M.; To, B.; Perkins, J. D.; Ginley, D. S.
Transparent conducting oxides (TCOs) are increasingly critical components in photovoltaic cells, low-e windows, flat panel displays, electrochromic devices, and flexible electronics. The conventional TCOs, such as Sn-doped In{sub 2}O{sub 3}, are crystalline single phase materials. Here, we report on In-Zn-O (IZO), a compositionally tunable amorphous TCO with some significantly improved properties. Compositionally graded thin film samples were deposited by co-sputtering from separate In{sub 2}O{sub 3} and ZnO targets onto glass substrates at 100 C. For the metals composition range of 55-84 cation% indium, the as-deposited IZO thin films are amorphous, smooth (R{sub RMS} < 0.4 nm), conductive ({sigma} {approx} 3000 {Omega}{sup -1} {center_dot} cm{sup -1}), and transparent in the visible (T{sub Vis} > 90%). Furthermore, the amorphous IZO thin films demonstrate remarkable functional and structural stability with respect to heating up to 600 C in either air or argon. Hence, though not completely understood at present, these amorphous materials constitute a new class of fundamentally interesting and technologically important high performance transparent conductors.
Igor I. Smolyaninov
Optical space in metamaterials may be engineered to mimic the landscape of a multidimensional Universe which has regions of different topology and different effective dimensionality. The "metamaterial landscape" may include regions in which one or two spatial dimensions are compactified. Nonlinear optics of metamaterials in these regions mimics either U(1) or SU(2) Kaluza-Klein theories having one or more kinds of effective charges. As a result, novel "photon blockade" nonlinear optical metamaterial devices may be realized. Topology-changing phase transitions in such metamaterials lead to considerable particle creation perceived as flashes of light, thus providing a toy model of birth of an individual physical Universe.
Peralta, Xomalin Guaiuli; Brener, Igal; O'Hara, John; Azad, Abul; Smirnova, Evgenya; Williams, John D.; Averitt, Richard D.
Terahertz metamaterials comprise a periodic array of resonator elements disposed on a dielectric substrate or thin membrane, wherein the resonator elements have a structure that provides a tunable magnetic permeability or a tunable electric permittivity for incident electromagnetic radiation at a frequency greater than about 100 GHz and the periodic array has a lattice constant that is smaller than the wavelength of the incident electromagnetic radiation. Microfabricated metamaterials exhibit lower losses and can be assembled into three-dimensional structures that enable full coupling of incident electromagnetic terahertz radiation in two or three orthogonal directions. Furthermore, polarization sensitive and insensitive metamaterials at terahertz frequencies can enable new devices and applications.
Plasmon-induced photonic switching in a metamaterial
H. Xu; B. S. Ham
Using light-induced localized surface plasmon interactions in a metamaterial, we present a plasmonic control of light absorption for photonic switching. We discuss that the present surface plasmon-induced photonic switching is comparable with coherence swapping in a tripod optical system based on electromagnetically induced transparency. This outcome opens a door to active controls of the surface plasmons in a metamaterial for potential applications of nano photonics.
Active terahertz metamaterials
Chen, Hou-tong [Los Alamos National Laboratory
We demonstrate planar terahertz metamaterial devices enabling actively controllable transmission amplitude, phase, or frequency at room temperature via carrier depletion or photoexcitation in the semiconductor substrate or in semiconductor materials incorporated into the metamaterial structure.
Resonant dielectric metamaterials
Loui, Hung; Carroll, James; Clem, Paul G; Sinclair, Michael B
A resonant dielectric metamaterial comprises a first and a second set of dielectric scattering particles (e.g., spheres) having different permittivities arranged in a cubic array. The array can be an ordered or randomized array of particles. The resonant dielectric metamaterials are low-loss 3D isotropic materials with negative permittivity and permeability. Such isotropic double negative materials offer polarization and direction independent electromagnetic wave propagation.
Milewski, M.A.; Delmolino, W.P.
An electrochemical cell is described comprising a cell container which is closed by a resilient insulative cell top and an electrode conductor inserted through the cell top and into an electrode of the cell, with the electrode conductor being physically and electrically accessible to the exterior of the cell whereby it functions as a terminal for the electrode, and wherein a portion of the electrode conductor is enclosed within the cell top, characterized in that the cell further comprises means for substantially restraining movement of the electrode conductor relative to the cell top. The electrode conductor has a nail configuration comprising a head and a shank with the head of the nail providing the external physical and electrical accessibility, wherein the restraining means is integrated with the shank of the nail. The restraining means is positioned on the shank, interior to the cell container and below the interior surface of the cell top and in close juxtaposition to the interior surface. The restraining means comprises a circumferential barb longitudinally disposed on the shank and having an upper portion which engages the interior surface to provide the substantial restraining of movement.
Active terahertz metamaterial devices
Chen, Houtong (Los Alamos, NM); Padilla, Willie John (Newton, MA); Averitt, Richard Douglas (Newton, MA); O'Hara, John F. (Los Alamos, NM); Lee, Mark (Albuquerque, NM)
Metamaterial structures are taught which provide for the modulation of terahertz frequency signals. Each element within an array of metamaterial (MM) elements comprises multiple loops and at least one gap. The MM elements may comprise resonators with conductive loops and insulated gaps, or the inverse in which insulated loops are present with conductive gaps; each providing useful transmissive control properties. The metamaterial elements are fabricated on a semiconducting substrate configured with a means of enhancing or depleting electrons from near the gaps of the MM elements. An on to off transmissivity ratio of about 0.5 is achieved with this approach. Embodiments are described in which the MM elements incorporated within a Quantum Cascade Laser (QCL) to provide surface emitting (SE) properties.
Three-dimensional metamaterials
Burckel, David Bruce (Albuquerque, NM)
A fabrication method is capable of creating canonical metamaterial structures arrayed in a three-dimensional geometry. The method uses a membrane suspended over a cavity with predefined pattern as a directional evaporation mask. Metallic and/or dielectric material can be evaporated at high vacuum through the patterned membrane to deposit resonator structures on the interior walls of the cavity, thereby providing a unit cell of micron-scale dimension. The method can produce volumetric metamaterial structures comprising layers of such unit cells of resonator structures.
Metamaterial flexible sheets could transform optics
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Metamaterial flexible sheets could transform optics Metamaterial flexible sheets could transform optics Advances would boost security screening systems, infrared thermal cameras,...
Chimeras in SQUID Metamaterials
N. Lazarides; G. Neofotistos; G. P. Tsironis
Regular lattices comprising Superconducting QUantum Interference Devices (SQUIDs) form magnetic metamaterials exhibiting extraordinary properties, including tuneability, dynamic multistability, and negative magnetic permeability. The SQUIDs in a metamaterial interact through non-local, magnetic dipole-dipole forces, that makes it possible for counter-intuitive dynamic states referred to as {\\em chimera states} to appear; the latter feature clusters of SQUIDs with synchronous dynamics which coexist with clusters exhibiting asynchronous behaviour. The spontaneous appearance of {\\em chimera states} is demonstrated numerically for SQUID metamaterials driven by an alternating magnetic field in which the fluxes threading the SQUID rings are randomly initialized; then, chimera states appear generically for sufficiently strong initial excitations, which exhibit relatively long life-times. The synchronization and metastability levels of the chimera states are discussed in terms of appropriate measures. Given that SQUID metamaterials have been already fabricated and investigated in the lab, the presence of a chimera state could in principle be detected with presently available experimental set-ups.
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transparencies to be recycled. 2.) SEPARATE the transparencies from ringed binders, plastic or paper folders, envelopes, andor files. 3.) PLACE the transparencies (only) into...
HorvÃth, I L; Marti, H P; Neuenschwander, J; Smith, R P; Fabbricatore, P; Musenich, R; Calvo, A; Campi, D; CurÕ, B; Desirelli, Alberto; Favre, G; Riboni, P L; Sgobba, Stefano; Tardy, T; Sequeira-Lopes-Tavares, S
The Compact Muon Solenoid (CMS) is one of the experiments, which are being designed in the framework of the Large Hadron Collider (LHC) project at CERN, the design field of the CMS magnet is 4 T, the magnetic length is 13 m and the aperture is 6 m. This high magnetic field is achieved by means of a 4 layer, 5 modules superconducting coil. The coil is wound from an Al-stabilized Rutherford type conductor. The nominal current of the magnet is 20 kA at 4.5 K. In the CMS coil the structural function is ensured, unlike in other existing Al-stabilized thin solenoids, both by the Al-alloy reinforced conductor and the external former. In this paper the retained manufacturing process of the 50-km long reinforced conductor is described. In general the Rutherford type cable is surrounded by high purity aluminium in a continuous co-extrusion process to produce the Insert. Thereafter the reinforcement is joined by Electron Beam Welding to the pure Al of the insert, before being machined to the final dimensions. During the...
Graphene-Silica Composite Thin Films as Transparent Conductors
as fillers for a broad range of composite materials. Attempts to exfoliate graphene-based sheets by intercalation of graphite with potassium metal have been discussed;34 however, the exfoliated nanoplatelets oxide-based sheets35,36 produced by complete exfoliation of graphite oxide (GO) as an entry
Doped graphene nanohole arrays for flexible transparent conductors
Liu, Jianwei; Xu, Guowei; Rochford, Caitlin; Lu, Rongtao; Wu, Judy; Edwards, Christina M.; Berrie, Cindy L.; Chen, Zhijun; Maroni, Victor A.
Graphene nanohole arrays (GNAs) were fabricated using nanoimprint lithography. The improved optical transmittance of GNAs is primarily due to the reduced surface coverage of graphene from the nanohole fabrication. Importantly, the exposed edges...
Floating insulated conductors for heating subsurface formations
Burns, David; Goodwin, Charles R.
A heating system for a subsurface formation includes a conduit located in a first opening in the subsurface formation. Three electrical conductors are located in the conduit. A return conductor is located inside the conduit. The return conductor is electrically coupled to the ends of the electrical conductors distal from the surface of the formation. Insulation is located inside the conduit. The insulation electrically insulates the three electrical conductors, the return conductor, and the conduit from each other.
Selective radiative heating of nanostructures using hyperbolic metamaterials
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Ding, Ding; Minnich, Austin J
Hyperbolic metamaterials (HMM) are of great interest due to their ability to break the diffraction limit for imaging and enhance near-field radiative heat transfer. Here we demonstrate that an annular, transparent HMM enables selective heating of a sub-wavelength plasmonic nanowire by controlling the angular mode number of a plasmonic resonance. A nanowire emitter, surrounded by an HMM, appears dark to incoming radiation from an adjacent nanowire emitter unless the second emitter is surrounded by an identical lens such that the wavelength and angular mode of the plasmonic resonance match. Our result can find applications in radiative thermal management.
Manipulating the plasmon-induced transparency in terahertz metamaterials
Oklahoma State University
Laboratory of Opto-Electronics Information and Technical Science, Ministry of Education, Tianjin University, China 2 School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, Oklahoma 79(8), 085111 (2009). 7. P. Tassin, L. Zhang, T. Koschny, E. N. Economou, and C. M. Soukoulis, "Low-loss
Paranthaman, Mariappan Parans [ORNL
Since the discovery of high-temperature superconductors (HTS) in 1986, both (Bi,Pb)2Sr2Ca2Cu3O10 (BSCCO or 2223 with a critical temperature, Tc of 110 K) and YBa2Cu3O7- (YBCO or 123 with a Tc of 91 K) have emerged as the leading candidate materials for the first generation (1G) and second generation (2G) high temperature superconductor wires or tapes that will carry high critical current density in liquid nitrogen temperatures [1-7]. The crystal structures and detailed fundamental properties of BSCCO and YBCO superconductors have been reviewed by Matsumoto in a separate chapter in this book. The U.S. Department of Energy s target price for the conductor is close to the current copper wire cost of $10-50/kA-meter, i.e. a meter of copper type conductor carrying 1000 A current costs ~ $ 50 [8]. The long-term goal for the DOE, Office of Electricity, Advanced Conductors and Cables program is to achieve HTS wire in 1000 meters long with current carrying capacity of 1000 A/cm [8]. Robust, high-performance HTS wire will certainly revolutionize the electric power grid and various other electric power equipments as well. Sumitomo Electric Power (Japan) has been widely recognized as the world leader in manufacturing the first-generation HTS wires based on BSCCO materials using the Oxide-Powder-In-Tube (OPIT) over-pressure process [9]. Typically, 1G HTS wires carry critical currents, Ic, of over 200 Amperes (A) in piece lengths of one kilometer lengths at the standard 4 mm width and ~ 200 m thickness. However, due to the higher cost of 1G wire, mainly because of the cost of Ag alloy sheath, the researchers shifted their effort towards the development of YBCO (second generation 2G) tapes in the last fifteen years [1-7]. One of the main obstacles to the ability to carry high critical currents in YBCO films has been the phenomenon of weak links, i.e., grain boundaries formed by the misalignment of neighboring YBCO grains are known to form obstacles to current flow [10]. By carefully aligning the grains in YBCO films, low angle boundaries between superconducting YBCO grains allow more current to flow. In fact below a critical misalignment angle of 4 , the critical current density approaches that of YBCO films grown on single crystal substrates [10]. Typically, 2G HTS wires have three components, flexible metal substrate, buffer layers, and REBa2Cu3O7- (REBCO: RE = Rare Earth) superconductor layers [1-7]. Several methods were developed to obtain biaxially textured templates suitable for fabricating high-performance YBCO coated conductors. They are Ion-Beam Assisted Deposition (IBAD), Rolling-Assisted Biaxially Textured Substrates (RABiTS) and Inclined-Substrate Deposition (ISD). Compared to 1G wire, for producing 2G wires using RABiTS or IBAD process, silver is replaced by a low cost nickel alloy, which allows for fabrication of less expensive HTS wires.
FDTD Analysis of Metamaterial Coated Microwave Antenna
Cholleti, Vipin K.
of the metamaterial antenna is reduced over the classical design while the radiation pattern of the antenna remains virtually unchanged....
Quartz antenna with hollow conductor
Leung, Ka-Ngo (Hercules, CA); Benabou, Elie (Alameda, CA)
A radio frequency (RF) antenna for plasma ion sources is formed of a hollow metal conductor tube disposed within a glass tube. The hollow metal tubular conductor has an internal flow channel so that there will be no coolant leakage if the outer glass tube of the antenna breaks. A portion of the RF antenna is formed into a coil; the antenna is used for inductively coupling RF power to a plasma in an ion source chamber. The antenna is made by first inserting the metal tube inside the glass tube, and then forming the glass/metal composite tube into the desired coil shape.
Terahertz antireflection coatings using metamaterials
Chen, Hou-tong [Los Alamos National Laboratory; Zhou, Jiangfeng [Los Alamos National Laboratory; O' Hara, John F [Los Alamos National Laboratory; Azad, Abul K [Los Alamos National Laboratory; Chen, Frank [Los Alamos National Laboratory; Taylor, Antoinette J [Los Alamos National Laboratory
We demonstrate terahertz metamaterial antireflection coatings (ARCs) that significantly reduce the reflection and enhance the transmission at an interface of dielectric media. They are able to operate over a wide range of incidence angles for both TM and TE polarizations. Experiments and finite-element simulations will be presented and discussed.
High Critical Current Coated Conductors
Paranthaman, M. P.; Selvamanickam, V. (SuperPower, Inc.)
One of the important critical needs that came out of the DOEs coated conductor workshop was to develop a high throughput and economic deposition process for YBCO. Metal-organic chemical vapor deposition (MOCVD) technique, the most critical steps in high technical micro fabrications, has been widely employed in semiconductor industry for various thin film growth. SuperPower has demonstrated that (Y,Gd)BCO films can be deposited rapid with world record performance. In addition to high critical current density with increased film thickness, flux pinning properties of REBCO films needs to be improved to meet the DOE requirements for various electric-power equipments. We have shown that doping with Zr can result in BZO nanocolumns, but at substantially reduced deposition rate. The primary purpose of this subtask is to develop high current density MOCVD-REBCO coated conductors based on the ion-beam assisted (IBAD)-MgO deposition process. Another purpose of this subtask is to investigate HTS conductor design optimization (maximize Je) with emphasis on stability and protection issues, and ac loss for REBCO coated conductors.
Conductor-polymer composite electrode materials
Ginley, D.S.; Kurtz, S.R.; Smyrl, W.H.; Zeigler, J.M.
A conductive composite material useful as an electrode, comprises a conductor and an organic polymer which is reversibly electrochemically dopable to change its electrical conductivity. Said polymer continuously surrounds the conductor in intimate electrical contact therewith and is prepared by electrochemical growth on said conductor or by reaction of its corresponding monomer(s) on said conductor which has been pre-impregnated or pre-coated with an activator for said polymerization. Amount of the conductor is sufficient to render the resultant composite electrically conductive even when the polymer is in an undoped insulating state.
Temperature limited heater utilizing non-ferromagnetic conductor
Vinegar; Harold J. (Bellaire, TX), Harris; Christopher Kelvin (Houston, TX)
A heater is described. The heater includes a ferromagnetic conductor and an electrical conductor electrically coupled to the ferromagnetic conductor. The ferromagnetic conductor is positioned relative to the electrical conductor such that an electromagnetic field produced by time-varying current flow in the ferromagnetic conductor confines a majority of the flow of the electrical current to the electrical conductor at temperatures below or near a selected temperature.
Graphene plasmonics for tunable terahertz metamaterials
Wang, Feng
Graphene plasmonics for tunable terahertz metamaterials Long Ju1 , Baisong Geng1,6 , Jason Horng1 metamaterials1Ù3 . Plasmons of two-dimensional massless electrons, as present in graphene, show unusual graphene micro- ribbonarrays.Wedemonstratethatgrapheneplasmonresonances can be tuned over a broad terahertz
Wave guides: vacuum w/ tube of conductor
Hart, Gus
Wave guides: vacuum w/ tube of conductor boundary conditions for conductor Properties: non-transverse waves except TEM mode in coaxial cable speed normal modes (from Liouville problem) TE or TM TEM for coaxial cable cuto frequency otherwise evanescent waves separation into and components with 1 #12;B
Flexible and Transparent Memory
H. Seo and K. L. Wang. , Flexible and Transparent Memory2] S. Kim and J. Lee Flexible Organic Transistor MemoryMemory Transistors for Flexible Sensor Arrays Science, Vol.
Supersymmetric transparent optical intersections
Stefano Longhi
Supersymmetric (SUSY) optical structures provide a versatile platform to manipulate the scattering and localization properties of light, with potential applications to mode conversion, spatial multiplexing and invisible devices. Here we show that SUSY can be exploited to realize broadband transparent intersections between guiding structures in optical networks for both continuous and discretized light. These include transparent crossing of high-contrast-index waveguides and directional couplers, as well as crossing of guiding channels in coupled resonator lattices.
Interferometric direction finding with a metamaterial detector
Venkatesh, Suresh; Schurig, David, E-mail: firstname.lastname@example.com [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)] [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Shrekenhamer, David; Padilla, Willie [Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467 (United States)] [Department of Physics, Boston College, Chestnut Hill, Massachusetts 02467 (United States); Xu, Wangren; Sonkusale, Sameer [Department of Electrical and Computer Engineering, Tufts University, Medford, Massachusetts 02155 (United States)] [Department of Electrical and Computer Engineering, Tufts University, Medford, Massachusetts 02155 (United States)
We present measurements and analysis demonstrating useful direction finding of sources in the S band (24?GHz) using a metamaterial detector. An augmented metamaterial absorber that supports magnitude and phase measurement of the incident electric field, within each unit cell, is described. The metamaterial is implemented in a commercial printed circuit board process with off-board back-end electronics. We also discuss on-board back-end implementation strategies. Direction finding performance is analyzed for the fabricated metamaterial detector using simulated data and the standard algorithm, MUtiple SIgnal Classification. The performance of this complete system is characterized by its angular resolution as a function of radiation density at the detector. Sources with power outputs typical of mobile communication devices can be resolved at kilometer distances with sub-degree resolution and high frame rates.
An electromagnetic black hole made of metamaterials
Cheng, Qiang
Traditionally, a black hole is a region of space with huge gravitational field in the means of general relativity, which absorbs everything hitting it including the light. In general relativity, the presence of matter-energy densities results in the motion of matter propagating in a curved spacetime1, which is similar to the electromagnetic-wave propagation in a curved space and in an inhomogeneous metamaterial2. Hence one can simulate the black hole using electromagnetic fields and metamaterials. In a recent theoretical work, an optical black hole has been proposed based on metamaterials, in which the numerical simulations showed a highly efficient light absorption3. Here we report the first experimental demonstration of electromagnetic black hole in the microwave frequencies. The proposed black hole is composed of non-resonant and resonant metamaterial structures, which can absorb electromagnetic waves efficiently coming from all directions due to the local control of electromagnetic fields. Hence the elect...
Active negative-index metamaterial powered by an electron beam
Shapiro, Michael
An active negative index metamaterial that derives its gain from an electron beam is introduced. The metamaterial consists of a stack of equidistant parallel metal plates perforated by a periodic array of holes shaped as ...
Levitated crystals and quasicrystals of metamaterials
Wang, Zhehui [Los Alamos National Laboratory; Morris, Christopher [Los Alamos National Laboratory; Goree, John A [Dept Phys and Astron., University of Iowa
New scientific and technological opportunities exist by marrying dusty plasma research with metamaterials. Specifically, by balancing control and self-assembly, certain laboratory plasmas can become a generic levitation platform for novel structure formation and nanomaterial synthesis. We propose to experimentally investigate two dimensional (2D) and three dimensional (3D) levitated structures of metamaterials and their properties. Such structures can self assemble in laboratory plasmas, similar to levitated dust crystals which were discovered in the mid 1990's. Laboratory plasma platform for metamaterial formation eliminates substrates upon which most metamaterials have to be supported. Three types of experiments, with similar setups, are discussed here. Levitated crystal structures of metamaterials using anisotropic microparticles are the most basic of the three. The second experiment examines whether quasicrystals of metamaterials are possible. Quasicrystals, discovered in the 1980's, possess so-called forbidden symmetries according to the conventional crystallography. The proposed experiment could answer many fundamental questions about structural, thermal and dynamical properties of quasicrystals. And finally, how to use nanoparticle coated microparticles to synthesize very long carbon nanotubes is also described. All of the experiments can fit inside a standard International Space Station locker with dimensions of 8-inch x 17-inch X 18-inch. Microgravity environment is deemed essential in particular for large 3D structures and very long carbon nanotube synthesis.
Wright, S. E. (Spencer E.); Konecni, S. (Snezana); Ammerman, C. N. (Curtt N.); Sims, J. R. (James R.)
This study presents development of a unique, powerful method for cooling high-frequency, AC conductors that can benefit end users of transformer windings, electrical machine windings, and magnet coils. This method of heat removal involves boiling a dielectric, fluorinert refrigerant that is in direct contact with litz wire conductors. A pool boiling test vessel is constructed, which provides for temperature control of the pool of fluorinert liquid. The test vessel is fitted with viewing ports so that the experiments are observed and studied with the aid of high-speed photography. Tests are performed on a variety of litz wire conductors. The boiling heat transfer coefficient is dependent on the conductor surface roughness. The size of the features on the conductor surface depends on the single-strand wire gage from which the conductor is constructed. All tests are performed with the conductors mounted horizontally. These tests are performed using a DC power supply. The results of these experiments will aid in the design of future cooling systems.
anisotropic metamaterials generated: Topics by E-print Network
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terahertz frequencies Engineering Websites Summary: Flexible metamaterial absorbers for stealth applications at terahertz frequencies Krzysztof: We have wrapped metallic...
anisotropic magnetodielectric metamaterials: Topics by E-print...
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terahertz frequencies Engineering Websites Summary: Flexible metamaterial absorbers for stealth applications at terahertz frequencies Krzysztof: We have wrapped metallic...
Transparent Cost Database | Transparent Cost Database
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 YouKizildere IRaghuraji Agro IndustriesTown of Ladoga, Indiana (Utility Company)Library < TransmissionTransparent
Indoor Powerline Conductor Accelerated Testing Facility (Indoor-PCAT)
conductors in parallel tests. The tension limitations (i.e., the number of conductors) inherent in towersIndoor Powerline Conductor Accelerated Testing Facility (Indoor-PCAT) Overview: The Indoor Powerline Conductor Accelerated Testing facility (or Indoor-PCAT), planned for construction in FY04 at Oak
A replacement consideration in conductor economics
Ciniglio Manzzo, Orlando Antonio
A REPLACEMENT CONSIDERATION IN CONDUCTOR ECONOMICS A Thesis by ORLANDO ANTONIO CINIGLIO MANZZO Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August... 1977 Major Subject: Electrical Engineering A REPLACEMENT CONSIDERATION IN CONDUCTOR ECONOMICS A Thesis ORLANDO ANTONIO CINIGLIO MANZZO Approved as to style and content by: (Chairman of Committee) // f, ', , / j (Head of Depart'ment) Member...
Product Information Transparent
Yoo, S. J. Ben
, transformers, amplifiers, high voltage resistor packs, and relays; adhesive/encapsulant for solar cellsProduct Information Solar FEATURES ôñ Transparent ôñ Cures to flexible elastomer ôñ Constant cure rate elastomer, which is suited for the protection of electrical/electronic devices in solar applications. HOW
Electrode with transparent series resistance for uniform switching of optical modulation devices
Tench, D. Morgan (Camarillo, CA); Cunningham, Michael A. (Thousand Oaks, CA); Kobrin, Paul H. (Newbury Park, CA)
Switching uniformity of an optical modulation device for controlling the propagation of electromagnetic radiation is improved by use of an electrode comprising an electrically resistive layer that is transparent to the radiation. The resistive layer is preferably an innerlayer of a wide-bandgap oxide sandwiched between layers of indium tin oxide or another transparent conductor, and may be of uniform thickness, or may be graded so as to provide further improvement in the switching uniformity. The electrode may be used with electrochromic and reversible electrochemical mirror (REM) smart window devices, as well as display devices based on various technologies.
A two-dimensional nanopatterned thin metallic transparent conductor with high transparency from the ultraviolet to the infrared
Demir, Hilmi Volkan
optoelectronic devices, including solar cells, flat panel displays, and light emitting diodes (LEDs). Most
Thermal conductor for high-energy electrochemical cells
Hoffman, Joseph A. (Minneapolis, MN); Domroese, Michael K. (South St. Paul, MN); Lindeman, David D. (Hudson, WI); Radewald, Vern E. (Austin, TX); Rouillard, Roger (Beloeil, CA); Trice, Jennifer L. (Eagan, MN)
A thermal conductor for use with an electrochemical energy storage device is disclosed. The thermal conductor is attached to one or both of the anode and cathode contacts of an electrochemical cell. A resilient portion of the conductor varies in height or position to maintain contact between the conductor and an adjacent wall structure of a containment vessel in response to relative movement between the conductor and the wall structure. The thermal conductor conducts current into and out of the electrochemical cell and conducts thermal energy between the electrochemical cell and thermally conductive and electrically resistive material disposed between the conductor and the wall structure. The thermal conductor may be fabricated to include a resilient portion having one of a substantially C-shaped, double C-shaped, Z-shaped, V-shaped, O-shaped, S-shaped, or finger-shaped cross-section. An elastomeric spring element may be configured so as to be captured by the resilient conductor for purposes of enhancing the functionality of the thermal conductor. The spring element may include a protrusion that provides electrical insulation between the spring conductor and a spring conductor of an adjacently disposed electrochemical cell in the presence of relative movement between the cells and the wall structure. The thermal conductor may also be fabricated from a sheet of electrically conductive material and affixed to the contacts of a number of electrochemical cells.
Flux Exclusion Superconducting Quantum Metamaterial: Towards
Zheludev, Nikolay
Flux Exclusion Superconducting Quantum Metamaterial: Towards Quantum-level Switching V. Savinov1, they require extremely high levels of nanofabrication. Here we introduce a new quantum superconducting properties of the mac- roscopic quantum state of superconducting carriers1 , and essentially plasmonic nature
Birck Nanotechnology Center Transforming Light with Metamaterials
Fiebig, Peter
Birck Nanotechnology Center Transforming Light with Metamaterials (with A.V. Kildishev, W. Cai, V.P. Drachev, S. Xiao, U. Chettiar) OUTLINE Birck Nanotechnology Center Vladimir M. Shalaev Purdue University;Birck Nanotechnology Center Meta-Magnetics: from 10GHz to 200THz Terahertz magnetism a) Yen, et al. ~ 1
Stators with improved conductor assembly and method of making same
Dang, Dang Dinh; Blissenbach, Rolf; Schauer, David; Wattleworth, John; Milani, Michael; Hatch, Erik
A stator includes a stator core, a plurality of slots, and a conductor. The plurality of slots are formed within the stator core. The conductor is disposed continuously within at least two of the plurality of openings.
Systematic Evaluation of Jc Decrease in Thick Film Coated Conductors
Alex Ignatiev; Dr. Amit Goyal
Address both thickness dependence of Jc, in thick film YBCO coated conductors through an application of a suite of new measurement techniques to thick film wire samples produced by commercially viable coated conductor technologies.
Reducing the losses of optical metamaterials
Fang, Anan
The field of metamaterials is driven by fascinating and far-reaching theoretical visions, such as perfect lenses, invisibility cloaking, and enhanced optical nonlinearities. However, losses have become the major obstacle towards real world applications in the optical regime. Reducing the losses of optical metamaterials becomes necessary and extremely important. In this thesis, two approaches are taken to reduce the losses. One is to construct an indefinite medium. Indefinite media are materials where not all the principal components of the permittivity and permeability tensors have the same sign. They do not need the resonances to achieve negative permittivity, {var_epsilon}. So, the losses can be comparatively small. To obtain indefinite media, three-dimensional (3D) optical metallic nanowire media with different structures are designed. They are numerically demonstrated that they are homogeneous effective indefinite anisotropic media by showing that their dispersion relations are hyperbolic. Negative group refraction and pseudo focusing are observed. Another approach is to incorporate gain into metamaterial nanostructures. The nonlinearity of gain is included by a generic four-level atomic model. A computational scheme is presented, which allows for a self-consistent treatment of a dispersive metallic photonic metamaterial coupled to a gain material incorporated into the nanostructure using the finite-difference time-domain (FDTD) method. The loss compensations with gain are done for various structures, from 2D simplified models to 3D realistic structures. Results show the losses of optical metamaterials can be effectively compensated by gain. The effective gain coefficient of the combined system can be much larger than the bulk gain counterpart, due to the strong local-field enhancement.
Synthesis of Oxidation-Resistant Cupronickel Nanowires for Transparent Conducting Nanowire Networks
Rathmall, Aaron [Duke University; Nguyen, Minh [Duke University; Wiley, Benjamin J [Duke University
Nanowires of copper can be coated from liquids to create flexible, transparent conducting films that can potentially replace the dominant transparent conductor, indium tin oxide, in displays, solar cells, organic light-emitting diodes, and electrochromic windows. One issue with these nanowire films is that copper is prone to oxidation. It was hypothesized that the resistance to oxidation could be improved by coating copper nanowires with nickel. This work demonstrates a method for synthesizing copper nanowires with nickel shells as well as the properties of cupronickel nanowires in transparent conducting films. Time- and temperature-dependent sheet resistance measurements indicate that the sheet resistance of copper and silver nanowire films will double after 3 and 36 months at room temperature, respectively. In contrast, the sheet resistance of cupronickel nanowires containing 20 mol % nickel will double in about 400 years. Coating copper nanowires to a ratio of 2:1 Cu:Ni gave them a neutral gray color, making them more suitable for use in displays and electrochromic windows. These properties, and the fact that copper and nickel are 1000 times more abundant than indium or silver, make cupronickel nanowires a promising alternative for the sustainable, efficient production of transparent conductors.
New Concept Conformal Antennas Utilizing Metamaterial and Transformation Optics
Luo, Yu
In this letter, we show by theoretical analysis and computer simulation that conformal antennas can be designed using metamaterial with inhomogeneous constitutive parameters by applying the electromagnetic coordinate ...
100 kA Record Current for HTS Conductor "A conductor current of 100,000 A is
Davis, James C.
in Japan. Fujikura Ltd. provided the tapes used in the experiment. "Yttrium-based HTS wire has been100 kA Record Current for HTS Conductor "A conductor current of 100,000 A is sufficient for fusion, our 100 kA is still lower, however ours is presently the world's highest among HTS conductors. Put
METAMATERIALS: Large-area printed 3D negative-index metamaterial is flexible -Laser Focus World http://www.laserfocusworld.com/articles/print/volume-47/issue-8/world-news/metamaterials-large-area-printed-3d-negative-index-metamaterial-is-flexible.html[8/1
Rogers, John A.
METAMATERIALS: Large-area printed 3D negative-index metamaterial is flexible - Laser Focus World-area printed 3D negative-index metamaterial is flexible METAMATERIALS: Large-area printed 3D negative, with the advent of a printing process that produces large-area 3D multilayer optical NIMs --8.7 æ 8.7 cm square
Radio and audible noise performance of T2 conductors
Chartier, V.L.; Lowder, S.M. [Bonneville Power Administration, Vancouver, WA (United States)] [Bonneville Power Administration, Vancouver, WA (United States); Rodick, S. [Burns and McDonnell, Kansas City, MO (United States)] [Burns and McDonnell, Kansas City, MO (United States); Vogt, M.W. [Central Iowa Power Cooperative, Cedar Rapids, IA (United States)] [Central Iowa Power Cooperative, Cedar Rapids, IA (United States)
Central Iowa Power Cooperative (CIPCO) plans to build a 345-kV line using a bundle of four Partridge T2 conductors. T2 conductor is two normal cylindrical conductors twisted together to prevent galloping during freezing rain and wind. Since it was not known whether any of the analytical expressions for calculating the radio and audible noise performance of conductors would work for T2 conductors, measurements were performed in the Bonneville Power Administration`s (BPA) high voltage laboratory to compare the radio influence voltage (RIV) and audible noise (AN) performance of the Partridge T2, Partridge and Dove conductors. The Dove conductor has about the same cross section and current carrying capacity as the Partridge T2 conductor. The tests showed that no consistent, measurable difference could be found in the RIV and AN levels between the Partridge T2 and Dove conductors under dry or artificial rain conditions and whether the conductors were arranged in bundles of 4, 3, or 2 subconductors or as single conductors.
Stretchable and Transparent Hydrogels as Soft Conductors for Dielectric Elastomer Actuators
Suo, Zhigang
interfaces,2,5 adaptive optics,6Ù8 generators,9,10 morphing wings,11 airships,12 and vibration isolators.13
p-Type Zinc Oxide Spinels: Application to Transparent Conductors and Spintronics
Stoica, Maria
We report on the electronic and optical properties of two theoretically predicted stable spinel compounds of the form ZnB2O4, where B = Ni or Cu; neither compound has been previously synthesized, so we compare them to the previously studied p-type ZnCo2O4 spinel. These new materials exhibit spin polarization that is ideal for spintronics applications, and broad conductivity maxima near the valence band edge that facilitate p-type dopability. We show that 3d electrons on the octahedrally coordinated Zn atom fall deep within the valence band and do not contribute significantly to the electronic structure of the material, while the O 2p and tetrahedrally coordinated B 3d electrons hybridize broadly in the shallow valence states, resulting in increasing curvature (i.e., decreased electron effective mass) of valence bands near the band edge. In particular, ZnCu2O4 exhibits high electrical conductivities near the valence band edge that, at sigma = 2 x 10^4 S/cm, are twice the maximum found for ZnCo2O4, a previously...
Center for Inverse Design Highlight: Anomalous Surface Conductivity in In2O3 Transparent Conductors
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Wireless energy transfer between anisotropic metamaterials shells
DÚaz-Rubio, Ana; Carbonell, Jorge; SÃnchez-Dehesa, JosÕ, E-mail: firstname.lastname@example.com
The behavior of strongly coupled Radial Photonic Crystals shells is investigated as a potential alternative to transfer electromagnetic energy wirelessly. These sub-wavelength resonant microstructures, which are based on anisotropic metamaterials, can produce efficient coupling phenomena due to their high quality factor. A configuration of selected constitutive parameters (permittivity and permeability) is analyzed in terms of its resonant characteristics. The coupling to loss ratio between two coupled resonators is calculated as a function of distance, the maximum (in excess of 300) is obtained when the shells are separated by three times their radius. Under practical conditions an 83% of maximum power transfer has been also estimated. -- Highlights: Anisotropic metamaterial shells exhibit high quality factors and sub-wavelength size. Exchange of electromagnetic energy between shells with high efficiency is analyzed. Strong coupling is supported with high wireless transfer efficiency. End-to-end energy transfer efficiencies higher than 83% can be predicted.
Metamaterials for threat reduction applications: imaging, signal processing, and cloaking
Metamaterials for threat reduction applications: imaging, signal processing, and cloaking R. D effort is underway to fill this "THz gap" in view of potential threat reduction applications) and Theoretical Divisions, are exploring metamaterials-based de- vices operating at THz frequencies for threat
Highly Strained Compliant Optical Metamaterials with Large Frequency
Atwater, Harry
of a metamaterial in the near-infrared by changing the distances and thus the coupling strength between pairs, we demonstrate dynamic surface-enhanced infrared absorption by tuning the metamaterial resonant frequency through a CH stretch vibrational mode, enhancing the reflection signal by a factor of 180
Electron Waiting Times in Mesoscopic Conductors
Mathias Albert; GÕraldine Haack; Christian Flindt; Markus B■ttiker
Electron transport in mesoscopic conductors has traditionally involved investigations of the mean current and the fluctuations of the current. A complementary view on charge transport is provided by the distribution of waiting times between charge carriers, but a proper theoretical framework for coherent electronic systems has so far been lacking. Here we develop a quantum theory of electron waiting times in mesoscopic conductors expressed by a compact determinant formula. We illustrate our methodology by calculating the waiting time distribution for a quantum point contact and find a cross-over from Wigner-Dyson statistics at full transmission to Poisson statistics close to pinch-off. Even when the low-frequency transport is noiseless, the electrons are not equally spaced in time due to their inherent wave nature. We discuss the implications for renewal theory in mesoscopic systems and point out several analogies with energy level statistics and random matrix theory.
Ionic conductors for solid oxide fuel cells
Krumpelt, Michael (Naperville, IL); Bloom, Ira D. (Bolingbrook, IL); Pullockaran, Jose D. (Hanover Park, IL); Myles, Kevin M. (Downers Grove, IL)
An electrolyte that operates at temperatures ranging from 600.degree. C. to 800.degree. C. is provided. The electrolyte conducts charge ionically as well as electronically. The ionic conductors include molecular framework structures having planes or channels large enough to transport oxides or hydrated protons and having net-positive or net-negative charges. Representative molecular framework structures include substituted aluminum phosphates, orthosilicates, silicoaluminates, cordierites, apatites, sodalites, and hollandites.
Experimental demonstration of metamaterial multiverse in a ferrofluid
Smolyaninov, Igor I; Bates, Evan; Smolyaninova, Vera N
Extraordinary light rays propagating inside a hyperbolic metamaterial look similar to particle world lines in a 2+1 dimensional Minkowski spacetime [1]. Magnetic nanoparticles in a ferrofluid are known to form nanocolumns aligned along the magnetic field, so that a hyperbolic metamaterial may be formed at large enough nanoparticle concentration nH. Here we investigate optical properties of such a metamaterial just below nH. While on average such a metamaterial is elliptical, thermal fluctuations of nanoparticle concentration lead to transient formation of hyperbolic regions (3D Minkowski spacetimes) inside this metamaterial. Thus, thermal fluctuations in a ferrofluid look similar to creation and disappearance of individual Minkowski spacetimes (universes) in the cosmological multiverse. This theoretical picture is supported by experimental measurements of polarization-dependent optical transmission of a cobalt based ferrofluid at 1500 nm.
Experimental demonstration of metamaterial multiverse in a ferrofluid
Igor I. Smolyaninov; Bradley Yost; Evan Bates; Vera N. Smolyaninova
Extraordinary light rays propagating inside a hyperbolic metamaterial look similar to particle world lines in a 2+1 dimensional Minkowski spacetime [1]. Magnetic nanoparticles in a ferrofluid are known to form nanocolumns aligned along the magnetic field, so that a hyperbolic metamaterial may be formed at large enough nanoparticle concentration nH. Here we investigate optical properties of such a metamaterial just below nH. While on average such a metamaterial is elliptical, thermal fluctuations of nanoparticle concentration lead to transient formation of hyperbolic regions (3D Minkowski spacetimes) inside this metamaterial. Thus, thermal fluctuations in a ferrofluid look similar to creation and disappearance of individual Minkowski spacetimes (universes) in the cosmological multiverse. This theoretical picture is supported by experimental measurements of polarization-dependent optical transmission of a cobalt based ferrofluid at 1500 nm.
Transparent fluids for 157-nm immersion lithography
Rollins, Andrew M.
Lawrence, Massachusetts 01843 Abstract. More than 50 fluorocarbon liquids are measured for transpar- ency; transpar- ency; fluorocarbon; fluoroether. Paper 014013 received Aug. 4, 2003; revised manuscript received
Precise Application of Transparent Conductive Oxide Coatings...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Application of Transparent Conductive Oxide Coatings for Flat Panel Displays and Photovoltaic Cells Technology available for licensing: New transparent conducting oxide (TCO)...
Flexible Terahertz Metamaterials: Towards a Terahertz Metamaterial Invisible Cloak , N. I. Landy2
In this work, we present flexible metamaterials on free standing polyimide substrates operating at terahertz fabricated on 5.5m thick polyimide substrates. The samples include purely electric resonator (#1 of the polyimide substrate; w, line width; l, length of the gap; g, gap distance. The SRR structure can be tuned
Conductor requirements for high-temperature superconducting utility power transformers
Pleva, E. F. [Waukesha Electric Systems, Waukesha, WI; Mehrotra, V. [Waukesha Electric Systems, Waukesha, WI; Schwenterly, S W [ORNL
High-temperature superconducting (HTS) coated conductors in utility power transformers must satisfy a set of operating requirements that are driven by two major considerations-HTS transformers must be economically competitive with conventional units, and the conductor must be robust enough to be used in a commercial manufacturing environment. The transformer design and manufacturing process will be described in order to highlight the various requirements that it imposes on the HTS conductor. Spreadsheet estimates of HTS transformer costs allow estimates of the conductor cost required for an HTS transformer to be competitive with a similarly performing conventional unit.
Development of twisted high-temperature superconductor composite conductors
Christopherson, C.J.; Riley, G.N. Jr. [American Superconductor Corporation, Westborough, Massachusetts 01581 (United States)] [American Superconductor Corporation, Westborough, Massachusetts 01581 (United States)
Multifilamentary high-temperature superconductor (HTS) composite conductors have been developed for alternating current (ac) applications. A twisted HTS conductor containing the Bi-2223 phase fabricated using a modified powder-in-tube technique is reported. Transport critical current densities of 13 800 and 10 900 A/cm {sup 2} (77 K, self-field, 1 {mu}V/cm) have been achieved for twisted tape and wire conductors with twist pitches of 3.7 and 3.6 mm, respectively. These conductors are strongly linked and are thus suitable for use in ac applications.
Micro-electro-mechanically switchable near infrared complementary metamaterial absorber
Pitchappa, Prakash; Pei Ho, Chong [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Institute of Microelectronics (IME), 11 Science Park Road, Singapore 117685 (Singapore); Kropelnicki, Piotr; Singh, Navab; Kwong, Dim-Lee [Institute of Microelectronics (IME), 11 Science Park Road, Singapore 117685 (Singapore); Lee, Chengkuo, E-mail: firstname.lastname@example.com [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore)
We experimentally demonstrate a micro-electro-mechanically switchable near infrared complementary metamaterial absorber by integrating the metamaterial layer to be the out of plane movable microactuator. The metamaterial layer is electrostatically actuated by applying voltage across the suspended complementary metamaterial layer and the stationary bottom metallic reflector. Thus, the effective spacing between the metamaterial layer and bottom metal reflector is varied as a function of applied voltage. With the reduction of effective spacing between the metamaterial and reflector layers, a strong spectral blue shift in the peak absorption wavelength can be achieved. With spacing change of 300?nm, the spectral shift of 0.7??m in peak absorption wavelength was obtained for near infrared spectral region. The electro-optic switching performance of the device was characterized, and a striking switching contrast of 1500% was achieved at 2.1??m. The reported micro-electro-mechanically tunable complementary metamaterial absorber device can potentially enable a wide range of high performance electro-optical devices, such as continuously tunable filters, modulators, and electro-optic switches that form the key components to facilitate future photonic circuit applications.
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Polymeric matrix materials for infrared metamaterials
Dirk, Shawn M; Rasberry, Roger D; Rahimian, Kamyar
A polymeric matrix material exhibits low loss at optical frequencies and facilitates the fabrication of all-dielectric metamaterials. The low-loss polymeric matrix material can be synthesized by providing an unsaturated polymer, comprising double or triple bonds; partially hydrogenating the unsaturated polymer; depositing a film of the partially hydrogenated polymer and a crosslinker on a substrate; and photopatterning the film by exposing the film to ultraviolet light through a patterning mask, thereby cross-linking at least some of the remaining unsaturated groups of the partially hydrogenated polymer in the exposed portions.
Seismic metamaterials based on isochronous mechanical oscillators
Finocchio, G., E-mail: email@example.com; Garescš, F.; Azzerboni, B. [Department of Electronic Engineering, Industrial Chemistry and Engineering, University of Messina, C.da di Dio, I-98166 Messina (Italy); Casablanca, O.; Chiappini, M. [Istituto Nazionale di Geofisica e Vulcanologia (INGV), Via Vigna Murata 605, 00143 Roma (Italy); Ricciardi, G. [Department of Civil, Informatic, Architectural, and Environmental Engineering and Applied Mathematics, C.da di Dio, I-98166 Messina (Italy); Alibrandi, U. [Department of Civil and Environmental Engineering, National University of Singapore, 1 Engineering Drive 2, Singapore 117576 (Singapore)
This Letter introduces a seismic metamaterial (SM) composed by a chain of mass-in-mass system able to filter the S-waves of an earthquake. We included the effect of the SM into the mono dimensional model for the soil response analysis. The SM modifies the soil behavior and in presence of an internal damping the amplitude of the soil amplification function is reduced also in a region near the resonance frequency. This SM can be realized by a continuous structure with inside a 3d-matrix of isochronous oscillators based on a sphere rolling over a cycloidal trajectory.
Testing of the 3M Company ACCR Conductor
Stovall, J.P.; RIzy, D.T.; Kisner, R.A.; Deve, H.E. (3M Comp.)
The 3M Company has developed a high-temperature low-sag conductor referred to as Aluminum- Conductor Composite-Reinforced or ACCR. The conductor uses an aluminum metal matrix material to replace the steel in conventional conductors so the core has a lower density and higher conductivity. The objective of this work is to accelerate the commercial acceptance by electric utilities of these new conductor designs by testing four representative conductor classes in controlled conditions. Overhead transmission lines use bare aluminum conductor strands wrapped around a steel core strands to transmit electricity. The typical cable is referred to as aluminum-conductor steel-reinforced (ACSR). The outer strands are aluminum, chosen for its conductivity, low weight, and low cost. The center strand is of steel for the strength required to support the weight without stretching the aluminum due to its ductility. The power density of a transmission corridor has been directly increased by increasing the voltage level. Transmission voltages have increased from 115-kV to 765- kV over the past 80 years. In the United States, further increasing the voltage level is not feasible at this point in time, so in order to further increase the power density of a transmission corridor, conductor designs that increase the current carrying capability have been examined. One of the key limiting factors in the design of a transmission line is the conductor sag which determines the clearance of the conductor above ground or underlying structures needed for electrical safety. Increasing the current carrying capability of a conductor increases the joule heating in the conductor which increases the conductor sag. A conductor designed for high-temperature and lowsag operation requires an engineered modification of the conductor materials. To make an advanced cable, the 3M Company solution has been the development of a composite conductor consisting of Nextel ceramic fibers to replace the steel core and an aluminum-zirconium alloy to improve the outer strands. The result is a cable that can carry more current than steelaluminum lines without sagging as much at higher temperatures. A unique facility called the Powerline Conductor Accelerated Testing (PCAT) Facility was built at ORNL for testing overhead conductors. The PCAT has been uniquely designed for testing overhead bare transmission line conductors at high currents and temperatures after they have been installed and tensioned to the manufacturer's specifications. The ability to operate a transmission line conductor in this manner does not exist elsewhere in the United States. Four classes of ACCR cable designed by 3M have been successfully test at ORNL small, medium, large and small/compact. Based on these and other manufacturer tests, the 3M Company has successfully introduced the ACCR into the commercial market and has completed over twenty installations for utility companies.
HTS Conductor Design Issues Including Quench and Stability,
HTS Conductor Design Issues Including Quench and Stability, AC Losses, and Fault Currents M. J objective and technical approach ñ The purpose of this collaborative R&D project is an investigation of HTS conductor design optimization with emphasis on stability and protection issues for YBCO wires and coils
Development and Testing of a BI-2212 Textured Powder Conductor
Damborsky, Kyle
Superconducting wires based on the high field superconductor Bi_(2)Sr_(2)Ca_(1)Cu_(2)O_(8)+x are an enabling technology for the development of very high field (>18 T) magnets. While these conductors have the potential to serve as the conductors...
Application of the Global Positioning System to the Measurement of Overhead Power Transmission Conductor Sag
, incident solar radiation, limiting physical conductor characteristics, and conductor configuration renewed importance because some companies are marketing transmission access. A widely used system
Towards a metamaterial simulation of a spinning cosmic string
Tom G. Mackay; Akhlesh Lakhtakia
Establishing the constitutive parameters of a nonhomogeneous bianisotropic medium that is equivalent to the spacetime metric of a spinning cosmic string, in a noncovariant formalism, we found a metamaterial route to investigate the existence of closed timelike curves.
Anisotropic Complementary Acoustic Metamaterial for Canceling out Aberrating Layers
Shen, Chen
In this paper, we investigate a type of anisotropic, acoustic complementary metamaterial (CMM) and its application in restoring acoustic fields distorted by aberrating layers. The proposed quasi two-dimensional (2D), ...
A novel approach to antireflection coating using planar metamaterials
Chen, Hou-tong [Los Alamos National Laboratory; Zhou, Jiangfeng [Los Alamos National Laboratory; O' Hara, John F [Los Alamos National Laboratory; Azad, Abul K [Los Alamos National Laboratory; Chen, Frank [Los Alamos National Laboratory; Taylor, Antoinette J [Los Alamos National Laboratory
We experimentally demonstrate a novel antireflection coating using planar metamaterials. It dramatically reduces the reflectance and enhances the transmittance over a wide range of incidence angles for both polarizations near the designed wavelength.
Terahertz superconductor metamaterial Jianqiang Gu,1,2
Oklahoma State University
School of Electrical and Computer Engineering, Oklahoma State University, Stillwater, Oklahoma 74078, USA, The Key Laboratory of Optoelectronics Information and Technical Science (Ministry of Education), Tianjin behavior of the superconducting metamaterial would lead to development of low loss terahertz switches
A review of nano-optics in metamaterial hybrid heterostructures
Singh, Mahi R. [Department of Physics and Astronomy, Western University, London N6G 3K7 (Canada)
We present a review for the nonlinear nano-optics in quantum dots doped in a metamaterial heterostructure. The heterostructure is formed by depositing a metamaterial on a dielectric substrate and ensemble of noninteracting quantum dots are doped near the heterostructure interface. It is shown that there is enhancement of the second harmonic generation due to the surface plasmon polaritons field present at the interface.
Electrochromic device with a polymer ionic conductor
Zhou, Y.; Gu, P.; Tang, J. [Zhejiang Univ., Hangzhou (China). Dept. of Optical Engineering
An electrochromic material is one which can undergo a reversible color change on the exertion of an external electric field. This can be used for large-area glazings of future buildings, automobiles, aircrafts, etc. Transmittance control of the smart windows can be useful to reduce lighting, heating and cooling energy loads. The optical and electrochromic properties of tungsten oxide films deposited by e-beam evaporation were investigated. A laminated structure device was prepared. The as-deposited tungsten oxide film was used as the electrochromic film. A solid polymer electrolyte PPG-PMMA-LiClO{sub 4} was used as an ionic conductor. Spectrophotometric measurements show that the luminous transmittance of the device can be modulated between about 60% and 15%.
Tunable hyperbolic metamaterials utilizing phase change heterostructures
Krishnamoorthy, Harish N. S.; Menon, Vinod M., E-mail: email@example.com [Department of Physics, Queens College of the City University of New York and Center for Photonic and Multiscale Nanomaterials, Queens, New York 11367 (United States); Department of Physics, Graduate Center of the City University of New York, New York, New York 10016 (United States); Zhou, You; Ramanathan, Shriram [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Narimanov, Evgenii [Birck Nanotechnology Center, School of Computer and Electrical Engineering, Purdue University, West Lafayette, Indiana 47907 (United States)
We present a metal-free tunable anisotropic metamaterial where the iso-frequency surface is tuned from elliptical to hyperbolic dispersion by exploiting the metal-insulator phase transition in the correlated material vanadium dioxide (VO{sub 2}). Using VO{sub 2}-TiO{sub 2} heterostructures, we demonstrate the transition in the effective dielectric constant parallel to the layers to undergo a sign change from positive to negative as the VO{sub 2} undergoes the phase transition. The possibility to tune the iso-frequency surface in real time using external perturbations such as temperature, voltage, or optical pulses creates new avenues for controlling light-matter interaction.
Transparent lithium-ion batteries , Sangmoo Jeongb
Cui, Yi
voltage window. For example, LiCoO2 and graphite, the most common cathode and anode in Li-ion batteriesTransparent lithium-ion batteries Yuan Yanga , Sangmoo Jeongb , Liangbing Hua , Hui Wua , Seok Woo, and solar cells; however, transparent batteries, a key component in fully integrated transparent devices
The efficiency of depth discrimination for non-transparent and transparent stereoscopic surfaces
Mamassian, Pascal
The efficiency of depth discrimination for non-transparent and transparent stereoscopic surfaces investigate here how well human observers cope with stereo transparency by comparing their efficiency between transparent and opaque depth judgments. In two experiments, the efficiency measure was computed relative
Superconductors and Complex Transition Metal Oxides for Tunable THz Plasmonic Metamaterials
Singh, Ranjan [Los Alamos National Laboratory; Xiong, Jie [Los Alamos National Laboratory; Azad, Md A. [Los Alamos National Laboratory; Yang, Hao [Los Alamos National Laboratory; Trugman, Stuart A. [Los Alamos National Laboratory; Jia, Quanxi [Los Alamos National Laboratory; Taylor, Antoinette [Los Alamos National Laboratory; Chen, Houtong [Los Alamos National Laboratory
The outline of this presentation are: (1) Motivation - Non-tunability of metal metamaterials; (2) Superconductors for temperature tunable metamaterials; (3) Ultrafast optical switching in superconductor metamaterials; (4) Controlling the conductivity with infrared pump beam; (5) Complex metal oxides as active substrates - Strontium Titanate; and (6) Conclusion. Conclusions are: (1) High Tc superconductors good for tunable and ultrafast metamaterials; (2) Large frequency and amplitude tunability in ultrathin superconductor films; (3) Such tunable properties cannot be accessed using metals; (4) Complex metal oxides can be used as active substrates - large tunability; (5) Complex oxides fail to address the issue of radiation losses in THz metamaterials.
Critical Current Metrology for Nb3Sn Conductor Development
Goodrich, Loren F. [NIST
The research is focused on the variable temperature studies of high-performance Nb3Sn and other high-field conductors for the next-generation of HEP magnets.
Fast dynamic force computation for electrostatic and electromagnetic conductors
Koteeswaran, Prabhavathi
This thesis presents an improved method for dynamic force computation applicable to both electrostatic and electromagnetic conductors with complex 3D geometries. During the transient simulation of electrostatic actuated MEMS, the positions...
Fast dynamic force computation for electrostatic and electromagnetic conductors
Koteeswaran, Prabhavathi
FAST DYNAMIC FORCE COMPUTATION FOR ELECTROSTATIC AND ELECTROMAGNETIC CONDUCTORS AThesis by PRABHAVATHI KOTEESWARAN Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 2004 Major Subject: Computer Engineering FAST DYNAMIC FORCE COMPUTATION FOR ELECTROSTATIC AND ELECTROMAGNETIC CONDUCTORS AThesis by PRABHAVATHI KOTEESWARAN Submitted to Texas A&M University in partial fulfillment...
Energy dependence of color transparency
Jennings, B.K. (TRIUMF, 4004 Wesbrook Mall, Vancouver, British Columbia, Canada V6T 2A3 (CA) Institute for Nuclear Theory, HN-12, University of Washington, Seattle, WA (USA)); Miller, G.A. (Department of Physics, FM-15, University of Washington, Seattle, WA (USA) Institute for Nuclear Theory, HN-12, University of Washington, Seattle, WA (USA))
A quantum-mechanical approach is used to study high-momentum-transfer reactions in which a nucleon is knocked out of a target nucleus. It is found that the nuclear interactions of the wave packet produced in such a hard interaction may cancel, so that the nuclear medium is transparent. Expressions for the effective wave-packet--nucleon interaction and the corresponding distorted waves are presented. An analysis of existing ({ital p},{ital pp}) data at beam momenta from about 5 to 12 GeV/{ital c} suggests that only the nucleon and Roper resonance components of the wave packet contribute to the scattering amplitude. The ({ital p},{ital pp}) data and our theory imply that color-transparency effects in the ({ital e},{ital e}{prime}{ital p}) reaction may be significant at relatively low-momentum transfers of {ital Q}{sup 2}{approx}3--6 GeV{sup 2}.
Review Article: The weak interactive characteristic of resonance cells and broadband effect of metamaterials
Zhao, Xiaopeng, E-mail: email@example.com; Song, Kun [Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University, Xian, 710129 (China)
Metamaterials are artificial media designed to control electromagnetic wave propagation. Due to resonance, most present-day metamaterials inevitably suffer from narrow bandwidth, extremely limiting their practical applications. On the basis of tailored properties, a metamaterial within which each distinct unit cell resonates at its inherent frequency and has almost no coupling effect with the other ones, termed as weak interaction system, can be formulated. The total response of a weak interaction system can be treated as an overlap of the single resonance spectrum of each type of different unit cells. This intriguing feature therefore makes it possible to accomplish multiband or broadband metamaterials in a simple way. By introducing defects into metamaterials to form a weak interaction system, multiband and broadband electromagnetic metamaterials have first been experimentally demonstrated by our group. The similar concept can also be readily extended to acoustic and seismic metamaterials.
Transparent electrode for optical switch
Goldhar, J.; Henesian, M.A.
The invention relates generally to optical switches and techniques for applying a voltage to an electro-optical crystal, and more particularly, to transparent electodes for an optical switch. System architectures for very large inertial confinement fusion (ICF) lasers require active optical elements with apertures on the order of one meter. Large aperture optical switches are needed for isolation of stages, switch-out from regenerative amplifier cavities and protection from target retroreflections.
Hyperbolic Metamaterial Feasible for Fabrication with Direct Laser Writing Processes
Zhang, Xu; G■ney, Durdu ø
Stimulated emission depletion microscopy inspired direct laser writing (STED-DLW) processes can offer diffraction-unlimited fabrication of 3D-structures, not possible with traditional electron-beam or optical lithography. We propose a hyperbolic metamaterial for fabrication with STED-DLW. First, we design meandering wire structures with three different magnetic dipoles which can be excited under different incidences of light. Then, based on effective parameters corresponding to normal incidence and lateral incidence, we find that the hyperbolic dispersion relation for five-layer structure appears between 15THz to 20THz. Finally, we investigate the influence of imaginary parts of the effective parameters on the metamaterial dispersion. The proposed metamaterial structure has also potential for three-dimensionally isotropic permeability despite geometric anisotropy.
Thermally Induced Nonlinear Optical Absorption in Metamaterial Perfect Absorbers
Guddala, Sriram; Ramakrishna, S Anantha
A metamaterial perfect absorber consisting of a tri-layer (Al/ZnS/Al) metal-dielectric-metal system with top aluminium nano-disks is fabricated by laser-interference lithography and lift-off processing. The metamaterial absorber had peak resonant absorbance at 1090 nm and showed nonlinear absorption for 600ps laser pulses at 1064 nm wavelength. A nonlinear saturation of reflectance was measured to be dependent on the average laser power incident and not the peak laser intensity. The nonlinear behaviour is shown to arise from the heating due to the absorbed radiation and photo-thermal changes in the dielectric properties of aluminium. The metamaterial absorber is seen to be damage resistant at large laser intensities of 25 MW/cm2.
Optical properties of two-dimensional metamaterial photonic crystals
MejÚa-Salazar, J. R. [Departamento de FÚsica, Universidad del Valle, AA 25360, Cali, Colombia and Instituto de FÚsica, UNICAMP, Campinas-SP 13083-859 (Brazil)
In the present work, we theoretically study a 2D photonic crystal (PC) comprised by double negative (DNG) metamaterial cylinders, showing that such a system presents a superior light-matter interaction when compared with their single negative (SNG) plasmonic PC counterparts, suggesting a route to enhance the performance of sensors and photovoltaic cells. On the other hand, we have observed that depending on the frequency, the mode symmetry resembles either the case of SNG electric (SNG-E) or SNG magnetic (SNG-M) PC, suggesting that either the electric or magnetic character of the DNG metamaterial dominates in each case.
Integrated digital metamaterials enables ultra-compact optical diodes
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Shen, Bing; Polson, Randy; Menon, Rajesh
We applied nonlinear optimization to design integrated digital metamaterials in silicon for unidirectional energy flow. Two devices, one for each polarization state, were designed, fabricated, and characterized. Both devices offer comparable or higher transmission efficiencies and extinction ratios, are easier to fabricate, exhibit larger bandwidths and are more tolerant to fabrication errors, when compared to alternatives. Furthermore, each device footprint is only 3?m æ 3?m, which is the smallest optical diode ever reported. To illustrate the versatility of digital metamaterials, we also designed a polarization-independent optical diode.
Quantification of disturbance energy due to conductor motion and stability analysis of superconducting composite wire
Tsukamoto, O.; Takao, T.; Honjo, S.
One of the most intricate disturbances causing quenches in high-current-density superconducting magnets is an abrupt conductor motion. There have been very few papers investigating the disturbance energy of the conductor motion and its generally understood that its quantification is very difficult. The authors have proposed a model to quantify the disturbance energy due to conductor motion. The model relates the disturbance energy to mechanical properties of a conductor, electromagnetic force and winding structure. In the paper, stability of a superconducting composite conductor subject to an abrupt conductor motion is analyzed based on the proposed model. It is pointed out that the stability of the conductor is improved by decreasing distance between spacers placed between the conductors. However, it is also pointed out that there is a limit to the improvement of the stability of decreasing the spacer distance, because of limited accuracies of the conductor and spacer dimensions.
New excitation system for indoor testing of overhead conductors
Gopalan, T.V. (Regional Engineering Coll., Calicut (India). Industry-Inst. Linkage Cell)
In the study of wind-induced motion of conductors of overhead power transmission lines, an indoor test span measuring 30 m or more is normally used. The span is generally excited into motion by an electrodynamic-type exciter connected at a span end. This connection increases the stiffness of the span at the point of connection, which will affect the dynamic characteristics of the test span. A more exact simulation of the indoor test-conductor motion is essential. Simulation of test-conductor motion using the principle of electrodynamic forces between parallel, long conductors is proposed. Indoor test-span motion by this method is equivalent to steady crosswinds excitation in the field as distinguished from galloping conductors resulting from a combination of wind direction, velocity, moisture, and temperature. Consequently, the results of vibration experiments also will be more exact. The principle employed in the new excitation system, the methods of excitation in indoor spans using the principle, and the advantages of the new excitation system as compared to the presently employed system are discussed in this paper.
Enhancing Optical Gradient Forces with Metamaterials Vincent Ginis,1
Enhancing Optical Gradient Forces with Metamaterials Vincent Ginis,1 Philippe Tassin,2,* Costas M demonstrate how the optical gradient force between two waveguides can be enhanced using transformation optics perceived by light, resulting in a more than tenfold enhancement of the optical force. This process
Complex Doppler effect in left-handed metamaterials
Ziemkiewicz, David
The Doppler shift is investigated in one-dimensional system with moving source. Theoretical findings are confirmed in numerical simulations of optical and acoustical waves propagation in simple metamaterial model, showing the reversed shift and the existence of multiple frequency modes. The properties of these waves are discussed. The effect of absorption on the phenomenon is outlined.
Temperature control of Fano resonances and transmission in superconducting metamaterials
Zheludev, Nikolay
, China 5 Shanghai Institute of Technical Physics, Chinese Academy of Sciences, Shanghai, 200083, China *firstname.lastname@example.com Abstract: Losses are the main evil that limits the use of metamaterials in practical applications. While radiation losses may be controlled by design, Joule losses are hereditary
Optimization of transparent and reflecting electrodes for amorphous-silicon solar cells. Final subcontract report, 1 May 1991--30 April 1994
Gordon, R.G.; Hu, J.; Lacks, D.; Musher, J.; Thornton, J.; Liang, H. [Harvard Univ., Cambridge, MA (United States)
Fluorine-doped zinc oxide was shown to have the lowest absorption loss of any of the known transparent conductors. An apparatus was constructed to deposit textured, transparent, conductive, fluorine-doped zinc oxide layers with uniform thickness over a 10 cm by 10 cm area, using inexpensive, high-productivity atmospheric pressure chemical vapor deposition. Amorphous silicon solar cells grown on these textured films show very high peak quantum efficiencies (over 90%). However, a significant contact resistance develops at the interface between the amorphous silicon and the zinc oxide. Transparent, conductive gallium-doped zinc oxide films were grown by APCVD at a low enough temperature (260{degree}C) to be deposited on amorphous silicon as a final conductive back contact to solar cells. A quantum-mechanical theory of bonding was developed and applied to some metal oxides; it forms a basis for understanding TCO structures and the stability of their interfaces with silicon.
Splice Resistance Measurements in 2G YBCO Coated Conductor
Rey, Christopher M [ORNL; Duckworth, Robert C [ORNL; Zhang, Yifei [ORNL
Abstract The Oak Ridge National Laboratory has been investigating the electrical splice resistance of second-generation (2G) YBCO coated conductor. The purpose of the experimental investigation is to study the splice resistance of 2G YBCO coated conductor as a function of: a) operating temperature, b) magnetic field strength (B-field), and c) magnetic field orientation ( ). Understanding the splice resistance with its corresponding variation as a function of surface preparation and operating conditions is essential to the practical implementation of electric utility devices; e.g., motors, generators, transformers, cables, and fault-current limiters, etc. Preliminary test results indicate that the 2G YBCO splice resistance shows a weak temperature dependence and a significantly stronger dependence upon magnetic field strength and magnetic field orientation. Surface preparation conditions are also briefly discussed. Index Terms coated conductor, splice, critical current, YBCO
Optimization of transparent and reflecting electrodes for amorphous silicon solar cells. Annual technical report, April 1, 1995--March 31, 1996
Gordon, R.G.; Sato, H.; Liang, H.; Liu, X.; Thornton, J. [Harvard Univ., Cambridge, MA (United States)
The general objective is to develop methods to deposit materials which can be used to make more efficient solar cells. The work is organized into three general tasks: Task 1. Develop improved methods for depositing and using transparent conductors of fluorine-doped zinc oxide in amorphous silicon solar cells Task 2. Deposit and evaluate titanium oxide as a reflection-enhancing diffusion barrier between amorphous silicon and an aluminum or silver back-reflector. Task 3. Deposit and evaluate electrically conductive titanium oxide as a transparent conducting layer on which more efficient and more stable superstrate cells can be deposited. About one-third of the current project resources are allocated to each of these three objectives.
Taylor, C.
NIOBIUM-TIN CONOOCTOR' C. Taylor, R. Meuser. S. Caspi. W.NIOBIUM-TIN CONDUCTOR C. Taylor, R. Meuser, S. Caspi, W.NIOBIUM-TIN CONDUCTOR* C. Taylor, R. Meuser, S. Caspi, W.
New Polymeric Proton Conductors for Water-free and High-temperature...
Broader source: Energy.gov (indexed) [DOE]
New Polymeric Proton Conductors for Water-free and High-temperature Fuel Cells New Polymeric Proton Conductors for Water-free and High-temperature Fuel Cells Presentation on New...
Using core-shell metamaterial engineering to triple the critical temperature of a superconductor
Smolyaninova, Vera N; Gresock, Thomas; Jensen, Christopher; Prestigiacomo, Joseph C; Osofsky, M S; Smolyaninov, Igor I
Recent experiments have shown the viability of the metamaterial approach to dielectric response engineering for moderately enhancing the transition temperature, Tc, of a superconductor. In this report, we demonstrate the use of Al2O3-coated aluminium nanoparticles to form the recently proposed epsilon near zero (ENZ) core-shell metamaterial superconductor with a Tc that is three times that of pure aluminium. IR reflectivity measurements confirm the predicted metamaterial modification of the dielectric function thus demonstrating the efficacy of the ENZ metamaterial approach to Tc engineering. These results provide an explanation for the long known, but not understood, enhancement of the Tc of granular aluminum films.
Industrial Cu-Ni alloys for HTS coated conductor tape. A Girard1,2,3
Boyer, Edmond
Industrial Cu-Ni alloys for HTS coated conductor tape. A Girard1,2,3 , C E Bruzek4 , J L Jorda1 , L efficient substrates for coated conductor wires. The study is focused on two industrial compositions: Cu55Ni-textured substrate is one of the critical steps for the HTS coated conductor development. The RABiTS (Rolling
High Strength Composite Conductors 2009 NHMFL Science Highlight for NSF
Weston, Ken
High Strength Composite Conductors 2009 NHMFL Science Highlight for NSF DMR-Award 0654118 Magnet-Award 0654118 Magnet Science and Technology International Collaborations This work is a result Science & Engineering, McMaster University, Canada and Dr. A. Misra from Los Alamos National Laboratory
Making the Economic Case for Innovative HTLS Overhead Conductors
#12;Executive Summary Obtaining new right of ways for constructing transmission lines to handle right of ways. High temperature, low sag overhead transmission conductors present an attractive option is available for downloading from the PSERC website. 2014 Arizona State University. All rights reserved. #12
Tuning the Properties of Transparent Oxide Conductors. Dopant Ion Size and Electronic Structure Effects on CdO-Based
Medvedeva, Julia E.
as key components in optoelectronic devices such as flat panel displays (FPDs), organic light-emitting diodes (OLEDs), photovoltaics, solar cells, optical waveguides, and energy-efficient windows.1
New York City Benchmarking and Transparency Policy Impact Evaluation...
New York City Benchmarking and Transparency Policy Impact Evaluation Report New York City Benchmarking and Transparency Policy Impact Evaluation Report Prepared for the U.S....
Rules for Service-Entrance Conductors Section 240.21(D) allows the service conductors to be tapped
Johnson, Eric E.
As state and federal incentives continue and proliferate, larger photovoltaic (PV) systems are being connection, as permitted in Section 230.82(6). In that section, photovoltaic systems are listed as equipment-entrance conductors be sized at 125 percent of the continuous loads. (All currents in a PV system are worst
Multiwire conductor having greatly increased interwire resistance and method for making same
Luhman, T.; Suenaga, M.
An improved multiwire conductor of the type which is mechanically stabilized by a tin based solder filler is described. A solder filled conductor is heated to a temperature above its melting point for a period long enough to allow a substantial amount of copper to be dissolved from the wires comprising the conductor. The copper forms the brittle intermetallic compound Cu/sub 5/Sn/sub 6/ with tin in the solder. After cooling the conductor is flexed causing a random cracking of the solder, and thereby increasing the interwire resistance of the conductor. The subject invention is particularly adapted for use with braided, ribbon-type solder filled superconductors.
Thin film electronic devices with conductive and transparent gas and moisture permeation barriers
Simpson, Lin Jay
A thin film stack (100, 200) is provided for use in electronic devices such as photovoltaic devices. The stack (100, 200) may be integrated with a substrate (110) such as a light transmitting/transmissive layer. A electrical conductor layer (120, 220) is formed on a surface of the substrate (110) or device layer such as a transparent conducting (TC) material layer (120,220) with pin holes or defects (224) caused by manufacturing. The stack (100) includes a thin film (130, 230) of metal that acts as a barrier for environmental contaminants (226, 228). The metal thin film (130,230) is deposited on the conductor layer (120, 220) and formed from a self-healing metal such as a metal that forms self-terminating oxides. A permeation plug or block (236) is formed in or adjacent to the thin film (130, 230) of metal at or proximate to the pin holes (224) to block further permeation of contaminants through the pin holes (224).
Dynamic frequency tuning of electric and magnetic metamaterial response
O'Hara, John F; Averitt, Richard; Padilla, Willie; Chen, Hou-Tong
A geometrically modifiable resonator is comprised of a resonator disposed on a substrate, and a means for geometrically modifying the resonator. The geometrically modifiable resonator can achieve active optical and/or electronic control of the frequency response in metamaterials and/or frequency selective surfaces, potentially with sub-picosecond response times. Additionally, the methods taught here can be applied to discrete geometrically modifiable circuit components such as inductors and capacitors. Principally, controlled conductivity regions, using either reversible photodoping or voltage induced depletion activation, are used to modify the geometries of circuit components, thus allowing frequency tuning of resonators without otherwise affecting the bulk substrate electrical properties. The concept is valid over any frequency range in which metamaterials are designed to operate.
High-Q terahertz metamaterial from superconducting niobium nitride films
Zhang, C H; Jin, B B; Ji, Z M; Kang, L; Xu, W W; Chen, J; Wu, P H
We present in this letter terahertz (THz) metamaterials with low ohmic losses made from low-temperature superconductor niobium nitride (NbN) films. The resonance properties are characterized by THz time-domain spectroscopy. The unloaded quality factor reaches as high as about 178 at 8 K with the resonance frequency at around 0.58 THz, which is about 24 times as many as gold metamaterials with the same structure. The unloaded quality factor also keeps high as the resonance frequency increases, which is about 90 at 1.02 THz that is close the gap frequency of NbN film. All these experimental observations are well understood in the framework of Bardeen-Cooper-Schrieffer theory and equivalent circuit model. Our work offers an efficient way to design and make high-performance THz electronic devices.
Magnetic levitation of metamaterial bodies enhanced with magnetostatic surface resonances
Urzhumov, Yaroslav; Bingham, Chris; Padilla, Willie; Smith, David R
We propose that macroscopic objects built from negative-permeability metamaterials may experience resonantly enhanced magnetic force in low-frequency magnetic fields. Resonant enhancement of the time-averaged force originates from magnetostatic surface resonances (MSR) which are analogous to the electrostatic resonances of negative-permittivity particles, well known as surface plasmon resonances in optics. We generalize the classical problem of MSR of a homogeneous object to include anisotropic metamaterials, and consider the most extreme case of anisotropy where the permeability is negative in one direction but positive in the others. It is shown that deeply subwavelength objects made of such indefinite (hyperbolic) media exhibit a pronounced magnetic dipole resonance that couples strongly to uniform or weakly inhomogeneous magnetic field and provides strong enhancement of the magnetic force, enabling applications such as enhanced magnetic levitation.
A Testing Platform for Validation of Overhead Conductor Aging Models and Understanding Thermal Limits
Irminger, Philip [ORNL; Starke, Michael R [ORNL; Dimitrovski, Aleksandar D [ORNL; Young II, Marcus Aaron [ORNL; Rizy, D Tom [ORNL; Stovall, John P [ORNL; Overholt, Philip N [U.S. Department of Energy, Office of Electricity Delivery and Energy Reliability (OE)
Power system equipment manufacturers and researchers continue to experiment with novel overhead electric conductor designs that support better conductor performance and address congestion issues. To address the technology gap in testing these novel designs, Oak Ridge National Laboratory constructed the Powerline Conductor Accelerated Testing (PCAT) facility to evaluate the performance of novel overhead conductors in an accelerated fashion in a field environment. Additionally, PCAT has the capability to test advanced sensors and measurement methods for accessing overhead conductor performance and condition. Equipped with extensive measurement and monitoring devices, PCAT provides a platform to improve/validate conductor computer models and assess the performance of novel conductors. The PCAT facility and its testing capabilities are described in this paper.
Resonant Casimir--Polder forces in planar meta-materials
Agnes Sambale; Stefan Yoshi Buhmann; Ho Trung Dung; Dirk-Gunnar Welsch
We study the resonant Casimir--Polder potential of an excited atom near a half space containing magneto-electric meta-material of various kinds on the basis of macroscopic quantum electrodynamics. Analytical results are obtained in the nonretarded and retarded distance regimes and numerical examples are given. We compare our findings with the potential of an excited atom near a left-handed superlens.
Acoustic wave propagation and stochastic effects in metamaterial absorbers
Christensen, J., E-mail: email@example.com; Willatzen, M. [Department of Photonics Engineering, Technical University of Denmark, DK-2800 Kgs. Lyngby (Denmark)
We show how stochastic variations of the effective parameters of anisotropic structured metamaterials can lead to increased absorption of sound. For this, we derive an analytical model based on the Bourret approximation and illustrate the immediate connection between material disorder and attenuation of the averaged field. We demonstrate numerically that broadband absorption persists at oblique irradiation and that the influence of red noise comprising short spatial correlation lengths increases the absorption beyond what can be archived with a structured but ordered system.
A waveguide model of the return stroke channel with a "metamaterial" corona
Lehtinen, Nikolai G.
) highly conducting thin core channel; (2) "metamaterial" corona, i.e., corona with an effective bulk, 2005], highly conducting thin core surrounded by a perfectly conducting cylindrical shell corona shieldA waveguide model of the return stroke channel with a "metamaterial" corona Nikolai G. Lehtinen1
An electromechanically reconfigurable plasmonic metamaterial operating in the near-infrared
Zheludev, Nikolay
An electromechanically reconfigurable plasmonic metamaterial operating in the near-infrared Jun and modulating metamaterial proper- ties in the visible and near-infrared range remain major technological to electromechanically reconfigure the metamolecules and dramatically change the transmission and reflection spectra
Scientists produce transparent, light-harvesting material
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
light-harvesting material The material could be used in development of transparent solar panels. November 3, 2010 Los Alamos National Laboratory sits on top of a once-remote...
Microsoft Word - Net Requirements Transparency Process_09302014
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
4 As part of its Net Requirements Transparency process, on July 31, 2014 BPA published the SliceBlock and Block customers' FY2013 and forecast FY2015 Total Retail Load (TRL) and...
Beyond transparency : collective engagement in sustainable design
Bonanni, Leonardo Amerigo, 1977-
For a timely answer to the question of sustainability, or how to provide for future generations, there needs to be shared accounting of our social and physical resources. Supply chain transparency makes it possible to map ...
Transparent conducting oxides and production thereof
Gessert, Timothy A.; Yoshida, Yuki; Coutts, Timothy J.
Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber. The method may also comprise depositing a metal oxide on the target in the process chamber to form a thin film having enhanced optical properties without substantially decreasing electrical quality.
Transparent conducting oxides and production thereof
Gessert, Timothy A; Yoshida, Yuki; Coutts, Timothy J
Transparent conducting oxides and production thereof are disclosed. An exemplary method of producing a transparent conducting oxide (TCO) material may comprise: providing a TCO target (110) doped with either a high-permittivity oxide or a low-permittivity oxide in a process chamber (100). The method may also comprise depositing a metal oxide on the target (110) to form a thin film having enhanced optical properties without substantially decreasing electrical quality.
High quality transparent conducting oxide thin films
Gessert, Timothy A. (Conifer, CO); Duenow, Joel N. (Golden, CO); Barnes, Teresa (Evergreen, CO); Coutts, Timothy J. (Golden, CO)
A transparent conducting oxide (TCO) film comprising: a TCO layer, and dopants selected from the elements consisting of Vanadium, Molybdenum, Tantalum, Niobium, Antimony, Titanium, Zirconium, and Hafnium, wherein the elements are n-type dopants; and wherein the transparent conducting oxide is characterized by an improved electron mobility of about 42 cm.sup.2/V-sec while simultaneously maintaining a high carrier density of .about.4.4e.times.10.sup.20 cm.sup.-3.
Exchanging Ohmic Losses in Metamaterial Absorbers with Useful Optical Absorption for Photovoltaics
Vora, Ankit; Pala, Nezih; Kulkarni, Anand; Pearce, Joshua M; G■ney, Durdu ø
Using metamaterial absorbers, we have shown that metallic layers in the absorbers do not necessarily constitute undesired resistive heating problem for photovoltaics. Tailoring the geometric skin depth of metals and employing the natural bulk absorbance characteristics of the semiconductors in those absorbers can enable the exchange of undesired resistive losses with the useful optical absorbance in the active semiconductors. Thus, Ohmic loss dominated metamaterial absorbers can be converted into photovoltaic near-perfect absorbers with the advantage of harvesting the full potential of light management offered by the metamaterial absorbers. Based on experimental permittivity data for indium gallium nitride, we have shown that between 75%-95% absorbance can be achieved in the semiconductor layers of the converted metamaterial absorbers. Besides other metamaterial and plasmonic devices, our results may also apply to photodectors and other metal or semiconductor based optical devices where resistive losses and p...
Catoptric electrodes: transparent metal electrodes using shaped surfaces
Kik, Pieter
-conductivity top contacts. ˋ 2014 Optical Society of America OCIS codes: (310.7005) Transparent conductive coatings
Vertically aligned gas-insulated transmission line having particle traps at the inner conductor
Dale, Steinar J. (Monroeville, PA)
Gas insulated electrical apparatus having first and second conductors separated by an insulating support within an insulating gas environment, and particle traps disposed along the surface of the high potential conductor for trapping and inactivating foreign particles which may be present within the insulating gas medium. Several embodiments of the invention were developed which are particularly suited for vertically aligned gas insulated transmission lines. The particle traps are grooves or cavities formed into the walls of the tubular inner conductor, without extending into the hollow portion of the conductor. In other embodiments, the traps are appendages or insert flanges extending from the inner conductor, with the insulator supports contacting the appendages instead of the inner conductor.
Semi-flexible gas-insulated transmission line using protection tube in conductor plug-in joint
Kommineni, P.R.
A gas-insulated transmission line includes an outer sheath, an inner conductor, an insulating gas electrically insulating the inner conductor from the outer sheath, and insulating supports insulatably supporting the inner conductor within the outer sheath. The inner conductor is provided with flexibility by main conductor sections which are joined together through a conductor hub section and flexible flexing elements. Stress shields are provided to control the electric field at the locations of the conductor hub sections where the insulating supports are contacting the inner conductor. A plug and socket arrangement is utilized for joining adjacent sections of the inner conductor, and a protection tube is utilized inside the hollow plug to maintain proper alignment of the joint when the transmission line is bent. 3 figs.
Microsoft Word - CX-BigEddy-Redmond-ConductorMaintenance-FY13...
Broader source: Energy.gov (indexed) [DOE]
4, 2013 REPLY TO ATTN OF: KEP-4 SUBJECT: Environmental Clearance Memorandum Stacy Hensley Project Manager - TEP-CSB-2 Proposed Action: Conductor maintenance on Bonneville Power...
High temperature superconducting composite conductor and method for manufacturing the same
Holesinger, Terry G. (Los Alamos, NM); Bingert, John F. (Jemez Springs, NM)
A high temperature superconducting composite conductor is provided including a high temperature superconducting material surrounded by a noble metal layer, the high temperature superconducting composite conductor characterized as having a fill factor of greater than about 40. Additionally, the conductor can be further characterized as containing multiple cores of high temperature superconducting material surrounded by a noble metal layer, said multiple cores characterized as having substantially uniform geometry in the cross-sectional dimensions. Processes of forming such a high temperature superconducting composite conductor are also provided.
Fabrication of transparent ceramics using nanoparticles
Cherepy, Nerine J; Tillotson, Thomas M; Kuntz, Joshua D; Payne, Stephen A
A method of fabrication of a transparent ceramic using nanoparticles synthesized via organic acid complexation-combustion includes providing metal salts, dissolving said metal salts to produce an aqueous salt solution, adding an organic chelating agent to produce a complexed-metal sol, heating said complexed-metal sol to produce a gel, drying said gel to produce a powder, combusting said powder to produce nano-particles, calcining said nano-particles to produce oxide nano-particles, forming said oxide nano-particles into a green body, and sintering said green body to produce the transparent ceramic.
Capacitive micromachined ultrasonic transducer arrays as tunable acoustic metamaterials
Lani, Shane W., E-mail: email@example.com, E-mail: firstname.lastname@example.com, E-mail: firstname.lastname@example.com; Sabra, Karim G. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801Ferst Drive, Georgia 30332-0405 (United States); Wasequr Rashid, M.; Hasler, Jennifer [School of Electrical and Computer Engineering, Georgia Institute of Technology, Van Leer Electrical Engineering Building, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250 (United States); Levent Degertekin, F. [George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, 801Ferst Drive, Georgia 30332-0405 (United States); School of Electrical and Computer Engineering, Georgia Institute of Technology, Van Leer Electrical Engineering Building, 777 Atlantic Drive NW, Atlanta, Georgia 30332-0250 (United States)
Capacitive Micromachined Ultrasonic Transducers (CMUTs) operating in immersion support dispersive evanescent waves due to the subwavelength periodic structure of electrostatically actuated membranes in the array. Evanescent wave characteristics also depend on the membrane resonance which is modified by the externally applied bias voltage, offering a mechanism to tune the CMUT array as an acoustic metamaterial. The dispersion and tunability characteristics are examined using a computationally efficient, mutual radiation impedance based approach to model a finite-size array and realistic parameters of variation. The simulations are verified, and tunability is demonstrated by experiments on a linear CMUT array operating in 2-12?MHz range.
Method for deposition of a conductor in integrated circuits
Creighton, J.R.; Dominguez, F.; Johnson, A.W.; Omstead, T.R.
A method is described for fabricating integrated semiconductor circuits and, more particularly, for the selective deposition of a conductor onto a substrate employing a chemical vapor deposition process. By way of example, tungsten can be selectively deposited onto a silicon substrate. At the onset of loss of selectivity of deposition of tungsten onto the silicon substrate, the deposition process is interrupted and unwanted tungsten which has deposited on a mask layer with the silicon substrate can be removed employing a halogen etchant. Thereafter, a plurality of deposition/etch back cycles can be carried out to achieve a predetermined thickness of tungsten. 2 figs.
Method for deposition of a conductor in integrated circuits
Creighton, J. Randall (Albuquerque, NM); Dominguez, Frank (Albuquerque, NM); Johnson, A. Wayne (Albuquerque, NM); Omstead, Thomas R. (Albuquerque, NM)
A method is described for fabricating integrated semiconductor circuits and, more particularly, for the selective deposition of a conductor onto a substrate employing a chemical vapor deposition process. By way of example, tungsten can be selectively deposited onto a silicon substrate. At the onset of loss of selectivity of deposition of tungsten onto the silicon substrate, the deposition process is interrupted and unwanted tungsten which has deposited on a mask layer with the silicon substrate can be removed employing a halogen etchant. Thereafter, a plurality of deposition/etch back cycles can be carried out to achieve a predetermined thickness of tungsten.
Suspended graphene films and their Casimir interaction with ideal conductor
I. V. Fialkovsky
We adopt the Dirac model for graphene and calculate the Casimir interaction energy between a plane suspended graphene sample and a parallel plane ideal conductor. We employ both the Quantum Field Theory (QFT) approach, and the Lifshitz formula generalizations. The first approach turns out to be the leading order in the coupling constant of the second one. The Casimir interaction for this system appears to be rather weak but experimentally measurable. It exhibits a strong dependence on the mass of the quasi-particles in graphene.
Contributing Storage using the Transparent File System
Berger, Emery
Contributing Storage using the Transparent File System JAMES CIPAR and MARK D. CORNER and EMERY D barrier to the adoption of contributory storage systems is that contributing a large quantity of local--all of the currently available space-- without impacting the performance of ordinary file access operations. We show
Process for forming transparent aerogel insulating arrays
Tewari, P.H.; Hunt, A.J.
An improved supercritical drying process for forming transparent silica aerogel arrays is described. The process is of the type utilizing the steps of hydrolyzing and condensing aloxides to form alcogels. A subsequent step removes the alcohol to form aerogels. The improvement includes the additional step, after alcogels are formed, of substituting a solvent, such as CO/sub 2/, for the alcohol in the alcogels, the solvent having a critical temperature less than the critical temperature of the alcohol. The resulting gels are dried at a supercritical temperature for the selected solvent, such as CO/sub 2/, to thereby provide a transparent aerogel array within a substantially reduced (days-to-hours) time period. The supercritical drying occurs at about 40/sup 0/C instead of at about 270/sup 0/C. The improved process provides increased yields of large scale, structurally sound arrays. The transparent aerogel array, formed in sheets or slabs, as made in accordance with the improved process, can replace the air gap within a double glazed window, for example, to provide a substantial reduction in heat transfer. The thus formed transparent aerogel arrays may also be utilized, for example, in windows of refrigerators and ovens, or in the walls and doors thereof or as the active material in detectors for analyzing high energy elementary particles or cosmic rays.
Process for forming transparent aerogel insulating arrays
Tewari, Param H. (Milpitas, CA); Hunt, Arlon J. (Oakland, CA)
An improved supercritical drying process for forming transparent silica aerogel arrays is described. The process is of the type utilizing the steps of hydrolyzing and condensing aloxides to form alcogels. A subsequent step removes the alcohol to form aerogels. The improvement includes the additional step, after alcogels are formed, of substituting a solvent, such as CO.sub.2, for the alcohol in the alcogels, the solvent having a critical temperature less than the critical temperature of the alcohol. The resulting gels are dried at a supercritical temperature for the selected solvent, such as CO.sub.2, to thereby provide a transparent aerogel array within a substantially reduced (days-to-hours) time period. The supercritical drying occurs at about 40.degree. C. instead of at about 270.degree. C. The improved process provides increased yields of large scale, structurally sound arrays. The transparent aerogel array, formed in sheets or slabs, as made in accordance with the improved process, can replace the air gap within a double glazed window, for example, to provide a substantial reduction in heat transfer. The thus formed transparent aerogel arrays may also be utilized, for example, in windows of refrigerators and ovens, or in the walls and doors thereof or as the active material in detectors for analyzing high energy elementry particles or cosmic rays.
Deformable Transparent All-Carbon-Nanotube Transistors
Maruyama, Shigeo
and organic materials16,17 are candidates for next-generation flexible and transparent electronic devices-carbon-nanotube field-effect transistors (CNT- FETs), making use of the flexible yet robust nature of single than those used in other flexible CNT-FETs allowed our devices to be highly deformable without
Nonlinear Terahertz Metamaterials via Field-Enhanced Carrier Dynamics in GaAs
Fan, Kebin
We demonstrate nonlinear metamaterial split ring resonators (SRRs) on GaAs at terahertz frequencies. For SRRs on doped GaAs films, incident terahertz radiation with peak fields of ?20160??kV/cm drives intervalley scattering. ...
Experimental demonstration of near-infrared epsilon-near-zero multilayer metamaterial slabs
Yang, Xiaodong; Deng, Huixu; Rosenmann, Daniel; Czaplewski, David A; Gao, Jie
Near-infrared epsilon-near-zero (ENZ) metamaterial slabs based on silver-germanium (Ag-Ge) multilayers are experimentally demonstrated. Transmission, reflection and absorption spectra are characterized and used to determine the complex refractive indices and the effective permittivities of the ENZ metamaterial slabs, which match the results obtained from both the numerical simulations and the optical nonlocalities analysis. A rapid post-annealing process is used to reduce the collision frequency of silver and therefore decrease the optical absorption loss of multilayer metamaterial slabs. Furthermore, multilayer grating structures are studied to enhance the optical transmission and also tune the location of ENZ wavelength. The demonstrated near-infrared ENZ multilayer metamaterial slabs are important for realizing many exotic applications, such as phase front shaping and engineering of photonic density of states.
Topological modes bound to dislocations in mechanical metamaterials
Jayson Paulose; Bryan Gin-ge Chen; Vincenzo Vitelli
Mechanical metamaterials are artificial structures with unusual properties, such as negative Poisson ratio, bistability or tunable vibrational properties, that originate in the geometry of their unit cell. At the heart of such unusual behaviour is often a soft mode: a motion that does not significantly stretch or compress the links between constituent elements. When activated by motors or external fields, soft modes become the building blocks of robots and smart materials. Here, we demonstrate the existence of topological soft modes that can be positioned at desired locations in a metamaterial while being robust against a wide range of structural deformations or changes in material parameters. These protected modes, localized at dislocations, are the mechanical analogue of topological states bound to defects in electronic systems. We create physical realizations of the topological modes in prototypes of kagome lattices built out of rigid triangular plates. We show mathematically that they originate from the interplay between two Berry phases: the Burgers vector of the dislocation and the topological polarization of the lattice. Our work paves the way towards engineering topologically protected nano-mechanical structures for molecular robotics or information storage and read-out.
Topological modes bound to dislocations in mechanical metamaterials
Jayson Paulose; Bryan Gin-ge Chen; Vincenzo Vitelli
Mechanical metamaterials are artificial structures with unusual properties, such as negative Poisson ratio, bistability or tunable vibrational properties, that originate in the geometry of their unit cell. At the heart of such unusual behaviour is often a soft mode: a motion that does not significantly stretch or compress the links between constituent elements. When activated by motors or external fields, soft modes become the building blocks of robots and smart materials. Here, we demonstrate the existence of topological soft modes that can be positioned at desired locations in a metamaterial while being robust against a wide range of structural deformations or changes in material parameters. These protected modes, localized at dislocations, are the mechanical analogue of topological states bound to defects in electronic systems. We create physical realizations of the topological modes in prototypes of kagome lattices built out of rigid triangular plates. We show mathematically that they originate from the interplay between two Berry phases: the Burgers vector of the dislocation and the topological polarization of the lattice. Our work paves the way towards engineering topologically protected nano-mechanical structures for molecular robotics or information storage and read-out.
Texas Cities in the Era of Government Transparency
Bearfield, Domonic; Bowman, Ann O'M
We are in the Era of Government Transparency. Recently, politicians from President Barack Obama to Texas Governor Rick Perry have touted a commitment to openness and transparency in their respective administrations. Citizens have also embraced...
Electromagnetically induced transparency with broadband laser pulses D. D. Yavuz
Yavuz, Deniz
Electromagnetically induced transparency with broadband laser pulses D. D. Yavuz Department pulses inside an atomic medium using electromag- netically induced transparency. Extending the suggestion.65. k Over the last decade, counterintuitive optical effects using electromagnetically induced
Characterization of Light Scattering in Transparent Polycrystalline Laser Ceramics
Sharma, Saurabh
Laser Media (PLM) .. 4 Bulk Scatteringacross and through the entire PLM regardless of dimensions.42 Characterization of Transparent PLM . 43
Zheng, Weiying
AN EFFICIENT EDDY CURRENT MODEL FOR NONLINEAR MAXWELL EQUATIONS WITH LAMINATED CONDUCTORS XUE JIANG AND WEIYING ZHENG Abstract. In this paper, we propose a new eddy current model for the nonlinear Maxwell equations with laminated conductors. Direct simulation of three-dimensional (3D) eddy currents in grain
Conductor Color-Coding In the recent past, most PV arrays have grounded the DC
Johnson, Eric E.
Conductor Color-Coding In the recent past, most PV arrays have grounded the DC negative conductor would be most clearly understood if it were black. The increasing use of transformerless inverters will dictate the use of ungrounded PV arrays (Section 690.35). Then we can adopt a "red is positive" and "black
Ceramic to metal attachment system. [Ceramic electrode to metal conductor in MHD generator
Marchant, D.D.
A composition and method are described for attaching a ceramic electrode to a metal conductor. A layer of randomly interlocked metal fibers saturated with polyimide resin is sandwiched between the ceramic electrode and the metal conductor. The polyimide resin is then polymerized providing bonding.
Thin magnetic conductor substrate for placement-immune, electrically-small antennas.
Eubanks, Travis Wayne; McDonald, Jacob J.; Loui, Hung
An antenna is considered to be placement-immune when the antenna operates effectively regardless of where it is placed. By building antennas on magnetic conductor materials, the radiated fields will be positively reinforced in the desired radiation direction instead of being negatively affected by the environment. Although this idea has been discussed thoroughly in theoretical research, the difficulty in building thin magnetic conductor materials necessary for in-phase field reflections prevents this technology from becoming more widespread. This project's purpose is to build and measure an electrically-small antenna on a new type of non-metallic, thin magnetic conductor. This problem has not been previously addressed because non-metallic, thin magnetic conductor materials have not yet been discovered. This work proposed the creation of an artificial magnetic conductor (AMC) with in-phase field reflections without using internal electric conductors, the placement of an electrically-small antenna on this magnetic conductor, and the development of a transmit-receive system that utilizes the substrate and electrically-small antenna. By not using internal electric conductors to create the AMC, the substrate thickness can be minimized. The electrically-small antenna will demonstrate the substrate's ability to make an antenna placement immune, and the transmit-receive system combines both the antenna and the substrate while adding a third layer of system complexity to demonstrate the complete idea.
Tension of Conductor Under Concentrated Loads WongS.P.Yu*,P.
Yu, Pei
Tension of Conductor Under Concentrated Loads WongS.P.Yu*,P. P.W. International Inc. 5H4V5RCanada be found. This paper presents methodologies to compute conductor tension and static con-underproceduressolutionexactandapproximatebothusingspacedimensionalthreeinprofile centrated loads with different boundary conditions. Practical engineering examples from galloping demon
Percolation in Transparent and Conducting Carbon Nanotube Networks
Gruner, George
and chemical sensors9 , field emission devices10,11 , and transparent conductive coatings7 . We12 , and another. Transmission measurements also indicate the usefulness of nanotube network films as a transparent, conductive coating. Avenues for improvement of the network transparency are discussed. KEYWORDS Nanotubes, Networks
Transparent monolithic metal ion containing nanophase aerogels
Risen, W. M., Jr.; Hu, X.; Ji, S.; Littrell, K.
The formation of monolithic and transparent transition metal containing aerogels has been achieved through cooperative interactions of high molecular weight functionalized carbohydrates and silica precursors, which strongly influence the kinetics of gelation. After initial gelation, subsequent modification of the ligating character of the system, coordination of the group VIII metal ions, and supercritical extraction afford the aerogels. The structures at the nanophase level have been probed by photon and electron transmission and neutron scattering techniques to help elucidate the basis for structural integrity together with the small entity sizes that permit transparency in the visible range. They also help with understanding the chemical reactivities of the metal-containing sites in these very high surface area materials. These results are discussed in connection with new reaction studies.
Theory of Dipole Induced Electromagnetic Transparency
Puthumpally-Joseph, Raiju; Sukharev, Maxim; Charron, Eric
A detailed theory describing linear optics of vapors comprised of interacting multi-level quantum emitters is proposed. It is shown both by direct integration of Maxwell-Bloch equations and using a simple analytical model that at large densities narrow transparency windows appear in otherwise completely opaque spectra. The existence of such windows is attributed to overlapping resonances. This effect, first introduced for three-level systems in [R. Puthumpally-Joseph, M. Sukharev, O. Atabek and E. Charron, Phys. Rev. Lett. 113, 163603 (2014)], is due to strongly enhanced dipole-dipole interactions at high emitters' densities. The presented theory extends this effect to the case of multilevel systems. The theory is applied to the D1 transitions of interacting Rb-85 atoms. It is shown that at high atomic densities, Rb-85 atoms can behave as three-level emitters exhibiting all the properties of dipole induced electromagnetic transparency. Applications including slow light and laser pulse shaping are also propose...
Dynamic, transparent Internet server replication using HYDRANET
Dillon, Geoffrey A.
-tolerance through redundancy, since Replicas can continue to function when their Origin Servers are no longer online. HYDRANET accomplishes these objectives by replicating Transport-level Service Access Points (TSAPs) [8] of servers in the operating system of our... modified Repli- cation Server. A modified IP-router provides the client traffic redirection by IP-in-IP tunneling. The use of TSAPs in this scheme allows us to selectively and transpar- ently replicate services from specific hosts without disrupting...
Transparent heat-spreader for optoelectronic applications
Minano, Juan Carlos; Benitez, Pablo
An optoelectronic cooling system is equally applicable to an LED collimator or a photovoltaic solar concentrator. A transparent fluid conveys heat from the optoelectronic chip to a hollow cover over the system aperture. The cooling system can keep a solar concentrator chip at the same temperature as found for a one-sun flat-plate solar cell. Natural convection or forced circulation can operate to convey heat from the chip to the cover.
Transparent conducting oxides: A -doped superlattice approach
Cooper, Valentino R [ORNL; Seo, Sung Seok A. [University of Kentucky, Lexington; Lee, Suyoun [ORNL; Kim, Jun Sung [Pohang University of Science and Technology (POSTECH), Pohang, Republic of Korea; Choi, Woo Seok [ORNL; Okamoto, Satoshi [ORNL; Lee, Ho Nyung [ORNL
Two-dimensional electron gases (2DEGs) at the interface of oxide heterostructures have been the subject of recent experiment and theory, due to the intriguing phenomena that occur in confined electronic states. However, while much has been done to understand the origin of 2DEGs and related phenomena, very little has been explored with regards to the control of conduction pathways and the distribution of charge carriers. Using first principles simulations and experimental thin film synthesis methods, we examine the effect of dimensionality on carrier transport in La delta-doped SrTiO3 (STO) superlattices, as a function of the thickness of the insulating STO spacer. Our computed Fermi surfaces and layer-resolved carrier density proles demonstrate that there is a critical thickness of the STO spacer, below which carrier transport is dominated by three-dimensional conduction of interface charges arising from appreciable overlap of the quantum mechanical wavefunctions between neighboring delta-doped layers. We observe that, experimentally, these superlattices remain highly transparent to visible light. Band structure calculations indicate that this is a result of the appropriately large gap between the O 2p and Ti d states. The tunability of the quantum mechanical wavefunctions and the optical transparency highlight the potential for using oxide heterostructures in novel opto-electronic devices; thus providing a route to the creation of novel transparent conducting oxides.
Energy transport faster than light in good conductors and superconductors
Z. Y. Wang
People need a model to study tachyons whose prediction can be tested easily. The dispersion relation w^2=k^2C^2-a^2C^2 of a low-frequency electromagnetic field in good conductors is equivalent to the energy-momentum equation E^2=p^2C^2-m^2C^4 of a tachyon where the proportionality coefficient is h^2. An experiment in 1980s to measure the phase velocity Vp [1] can be regarded as an indirect evidence of the superluminal velocity V>>c of those photons just equals the rate of energy flow S/w of the field.Instability of the tachyonic field corresponds to the Joule heat. To detect the speed of energy is difficult and we plan to modulate signals to observe the information velocity (speed of points of non-analyticity)[2].
Segmented saddle-shaped passive stabilization conductors for toroidal plasmas
Leuer, J.A.
A large toroidal vacuum chamber for plasma generation and confinement is lined with a toroidal blanket for shielding using modules segmented in the toroidal direction. To provide passive stabilization in the same manner as a conductive vacuum chamber wall, saddle-shaped conductor loops are provided on blanket modules centered on a midplane of the toroidal chamber with horizontal conductive bars above and below the midplane, and vertical conductive legs on opposite sides of each module to provide return current paths between the upper and lower horizontal conductive bars. The close proximity of the vertical legs provided on adjacent modules without making physical contact cancel the electromagnetic field of adjacent vertical legs. The conductive bars spaced equally above and below the midplane simulate toroidal conductive loops or hoops that are continuous, for vertical stabilization of the plasma even though they are actually segmented. 5 figs.
Strain tolerances in Nb/sub 3/Sn conductors
Luhman, T.
This paper reviews the literature pertinent to the effect of strain on the critical currents of a variety of differently heat-treated multifilamentary Nb/sub 3/Sn superconductors. The dependence of the critical currents on the parameters of uniaxial, tensile, bending, and intrinsic strains, and on temperature and composite ratio variations, is both plotted and analyzed. A review of specific efforts to enhance the strain tolerances of Nb/sub 3/Sn superconductors is given. Those efforts include 1) the approach of minimizing an accomodating plastic flow in the bronze during a cooldown from the reaction heat treatment temperaure by alloying the bronze with Be; 2) the method of jacketing a conductor with stainless steel to enhance the effect R /SUB v/ ; and 3) the ''wind and react'' approach, or the procedure olf vacuum-impregnating the coil windings with epoxy following the reaction heat treatment.
A High Conducting Oxide Sulfide Composite Lithium Superionic Conductor
Rangasamy, Ezhiylmurugan [ORNL] [ORNL; Keum, Jong Kahk [ORNL] [ORNL; Sahu, Gayatri [ORNL] [ORNL; Rondinone, Adam Justin [ORNL; Dudney, Nancy J [ORNL] [ORNL; Liang, Chengdu [ORNL] [ORNL
A hybrid superionic conductor was fabricated utilizing the space charge effect between the LLZO and LPS interfaces. This space-charge effect resulted in an improvement over the individual bulk conductivities of the two systems. Sample with higher weight fractions of LLZO are limited by the porosity and grain boundary resistance arising from non-sintered membranes. By combining the properties of LLZO and LPS, the high temperature sintering step has been avoided thus facilitating easier materials processing. The interfacial resistances were also measured to be minimal at ambient conditions. This procedure thus opens a new avenue for improving the ionic conductivity and electrochemical properties of existing solid state electrolytes. High frequency impedance analyses could aid in resolving the ionic conductivity contributions from the space charge layer in the higher conducting composites while mechanical property investigations could illustrate an improvement in the composite electrolyte in comparison with the crystalline LPS membranes.
Ground-based transmission line conductor motion sensor
Jacobs, M.L.; Milano, U.
A ground-based-conductor motion-sensing apparatus is provided for remotely sensing movement of electric-power transmission lines, particularly as would occur during the wind-induced condition known as galloping. The apparatus is comprised of a motion sensor and signal-generating means which are placed underneath a transmission line and will sense changes in the electric field around the line due to excessive line motion. The detector then signals a remote station when a conditioning of galloping is sensed. The apparatus of the present invention is advantageous over the line-mounted sensors of the prior art in that it is easier and less hazardous to install. The system can also be modified so that a signal will only be given when particular conditions, such as specific temperature range, large-amplitude line motion, or excessive duration of the line motion, are occurring.
Solderability Study of RABiTS-Based YBCO Coated Conductors
Zhang, Yifei [ORNL; Duckworth, Robert C [ORNL; Ha, Tam T [ORNL; Gouge, Michael J [ORNL
The solderability of commercially available YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO) coated conductors that were made from Rolling Assisted Biaxially Textured Substrates (RABiTS)-based templates was studied. The coated conductors, also known as second-generation (2G) high temperature superconductor (HTS) wires (in the geometry of flat tapes about 4 mm wide), were laminated with copper, brass, or stainless steel strips as stabilizers. To understand the factors that influence their solderability, surface profilometry and scanning electron microscopy were used to characterize the wire surfaces. The solderability of three solders, 52In48Sn, 67Bi33In, and 100In (wt.%), was evaluated using a standard test (IPC/ECA J-STD-002) and with two different commercial fluxes. It was found that the solderability varied with the solder and flux but the three different wires showed similar solderability for a fixed combination of solder and flux. Solder joints of the 2G wires were fabricated using the tools and the procedures recommended by the HTS wire manufacturer. The solder joints were made in a lap-joint geometry and with the superconducting sides of the two wires face-to-face. The electrical resistances of the solder joints were measured at 77 K, and the results were analyzed to qualify the soldering materials and evaluate the soldering process. It was concluded that although the selection of soldering materials affected the resistance of a solder joint, the resistivity of the stabilizer was the dominant factor.
Multimode circuit QED with hybrid metamaterial transmission lines
Daniel J. Egger; Frank K. Wilhelm
Quantum transmission lines are a central to superconducting and hybrid quantum computing. Parallel to these developments are those of left-handed meta-materials. They have a wide variety of applications in photonics from the microwave to the visible range such as invisibility cloaks and perfect flat lenses. For classical guided microwaves, left-handed transmission lines have been proposed and studied on the macroscopic scale. We combine these ideas in presenting a left-handed/right-handed hybrid transmission line for applications in quantum optics on a chip. The resulting system allows circuit QED to reach a new regime: multi-mode ultra-strong coupling. Out of the many potential applications of this novel device, we discuss two; the preparation of multipartite entangled states and its use as a quantum simulator for the spin-boson model where a quantum phase transition is reached up to finite size-effects.
On the possibility of Casimir repulsion using metamaterials
Da Rosa, Felipe S [Los Alamos National Laboratory
It is well known that the Casimir force between two half-spaces is dictated by their electromagnetic properties. In particular, when one of the half-spaces is mainly metallic or dielectric and the other is mainly magnetic, it is possible to show that the force is repulsive. This has attracted lots of interest towards the study of metamaterials (MMs) in the context of Casimir effect, as their magnetic activity might help bring the idea of Casimir repulsion from the theoretical realm to experimental verification. In this paper we investigate the possibility of repulsion when the MM magnetic permeability is given not by a Drude-Lorentz behavior, but by a model put forward by Pendry et al. [16]. After introducing the model and deriving the necessary formulas, we show that it is impossible to achieve repulsion with such a model and present a qualitative discussion of why this is so.
A passively tunable acoustic metamaterial lens for selective ultrasonic excitation
Zhu, H.; Semperlotti, F., E-mail: firstname.lastname@example.com [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
In this paper, we present an approach to ultrasonic beam-forming and beam-steering in structures based on the concept of embedded acoustic metamaterial lenses. The lens design exploits the principle of acoustic drop-channel that enables the dynamic coupling of multiple ultrasonic waveguides at selected frequencies. In contrast with currently available technology, the embedded lens allows exploiting the host structure as a key component of the transducer system therefore enabling directional excitation by means of a single ultrasonic transducer. The design and the performance of the lens are numerically investigated by using Plane Wave Expansion and Finite Difference Time Domain techniques applied to bulk structures. Then, the design is experimentally validated on a thin aluminum plate waveguide where the lens is implemented by through-holes. The dynamic response of the embedded lens is estimated by reconstructing, via Laser Vibrometry, the velocity field induced by a single source located at the center of the lens.
Glatkowski, P.J.; Landis, D.A.
Todays solar cells are fabricated using metal oxide based transparent conductive coatings (TCC) or metal wires with optoelectronic performance exceeding that currently possible with Carbon Nanotube (CNT) based TCCs. The motivation for replacing current TCC is their inherent brittleness, high deposition cost, and high deposition temperatures; leading to reduced performance on thin substrates. With improved processing, application and characterization techniques Nanofiber and/or CNT based TCCs can overcome these shortcomings while offering the ability to be applied in atmospheric conditions using low cost coating processes At todays level of development, CNT based TCC are nearing commercial use in touch screens, some types of information displays (i.e. electronic paper), and certain military applications. However, the resistivity and transparency requirements for use in current commercial solar cells are more stringent than in many of these applications. Therefore, significant research on fundamental nanotube composition, dispersion and deposition are required to reach the required performance commanded by photovoltaic devices. The objective of this project was to research and develop transparent conductive coatings based on novel nanomaterial composite coatings, which comprise nanotubes, nanofibers, and other nanostructured materials along with binder materials. One objective was to show that these new nanomaterials perform at an electrical resistivity and optical transparency suitable for use in solar cells and other energy-related applications. A second objective was to generate new structures and chemistries with improved resistivity and transparency performance. The materials also included the binders and surface treatments that facilitate the utility of the electrically conductive portion of these composites in solar photovoltaic devices. Performance enhancement venues included: CNT purification and metallic tube separation techniques, chemical doping, CNT patterning and alignment, advances in commercial and research materials and field effect schemes. In addition, Eikos continued to develop improved efficiency coating materials and transfer methods suitable for batch and continuous roll-to-roll fabrication requirements. Finally, Eikos collaborated with NREL and the PV-community at large in fabricating and characterizing Invisiconû?ô?û?ôÛ enabled solar cells.
Liquid fuel vaporizer and combustion chamber having an adjustable thermal conductor
Powell, Michael R; Whyatt, Greg A; Howe, Daniel T; Fountain, Matthew S
The efficiency and effectiveness of apparatuses for vaporizing and combusting liquid fuel can be improved using thermal conductors. For example, an apparatus having a liquid fuel vaporizer and a combustion chamber can be characterized by a thermal conductor that conducts heat from the combustion chamber to the vaporizer. The thermal conductor can be a movable member positioned at an insertion depth within the combustion chamber that corresponds to a rate of heat conduction from the combustion chamber to the vaporizer. The rate of heat conduction can, therefore, be adjusted by positioning the movable member at a different insertion depth.
NPT Transparency Visit | National Nuclear Security Administration
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. DOE Office of Science (SC)Integrated CodesTransparency Visit | National Nuclear Security Administration Facebook
Multiple-scattering series for color transparency
Greenberg, W.R.; Miller, G.A. (Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))
Cold transparency (CT) depends on the formation of a wave packet of small spatial extent. It is useful to interpret experimental searches for CT with a multiple-scattering series based on wave-packet--nucleon scattering instead of the standard one using nucleon-nucleon scattering. We develop several new techniques which are valid for differing ranges of energy. These techniques are applied to verify some early approximations, study new forms of the wave-packet--nucleon interaction, examine effects of treating wave packets of nonzero size, and predict the production of [ital N][sup *]'s in electron scattering experiments.
Transparent Cost Database | Open Energy Information
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Stress-tuned conductor-polymer composite for use in sensors
Martin, James E; Read, Douglas H
A method for making a composite polymeric material with electrical conductivity determined by stress-tuning of the conductor-polymer composite, and sensors made with the stress-tuned conductor-polymer composite made by this method. Stress tuning is achieved by mixing a miscible liquid into the polymer precursor solution or by absorbing into the precursor solution a soluble compound from vapor in contact with the polymer precursor solution. The conductor may or may not be ordered by application of a magnetic field. The composite is formed by polymerization with the stress-tuning agent in the polymer matrix. The stress-tuning agent is removed following polymerization to produce a conductor-polymer composite with a stress field that depends on the amount of stress-tuning agent employed.
Taylor, C.
DIPOLE HAGNET USING NIOBIUM-TIN CONOOCTOR' C. Taylor, R.DIPOLE MAGNET USING NIOBIUM-TIN CONDUCTOR C. Taylor, R.slid tooling for the niobium- tin magnet .sre on halld, and
Rapid synthesis and size control of CuInS2 semi-conductor nanoparticle...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
semi-conductor nanoparticles make them attractive materials for use in next-generation photovoltaics. We have prepared CuInS2 nanoparticles from single source precursors via...
Rapid Synthesis and Size Control of CuInS2 Semi-Conductor Nanoparticle...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
semi-conductor nanoparticles make them attractive materials for use in next-generation photovoltaics. We have prepared CuInS2 nanoparticles from single source precursors via...
Risk assessment and evaluation of the conductor setting depth in shallow water, Gulf of Mexico
Tu, Yong B.
. Earlier risk assessment tools and general engineering practice guidelines for the determination of the conductor casing design were based more on traditional practices rather than sound engineering practices. This study focuses on the rudimentary...
Soil-Spring Model for Fatigue Evaluation of Cyclic-Loaded Offshore Conductors
Ilupeju, Olusola Ayandire
more important. Design considerations and methodology for dealing with conductors and piles subjected to cyclic lateral loads, have been based on modifications to formulations for monotonic loads. Soil-structure interaction problems involving offshore...
New Polymeric Proton Conductors for Water-free and High-temperature Fuel Cells
Broader source: Energy.gov [DOE]
Presentation on New Polymeric Proton Conductors for Water-free and High-temperature Fuel Cells to the High Temperature Membrane Working Group Meeting held in Arlington, Virginia, May 26,2005.
Thermal hydraulic characteristics study of prototype NET and CEA cable-in-conduit conductors (CICCs)
Maekawa, Ryuji
The thermal hydraulic characteristics of low temperature helium in a Cable-in-Conduit Conductor (CICC) significantly affects the overall design and performance of the associated large scale superconducting magnet system. It is essential to understand the transient and steady state behavior of the helium in the conductor. Throughout the development of CICCs, the reduction of flow impedance has been one of the key factors to improving the overall pressure drop. The newly developed CICC for the ITER project has a hybrid cooling scheme: a central channel that is surrounded by bundles, for which the thermal hydraulic characteristics are not well understood. This thesis describes an experimental and analytical investigation of thermal hydraulic characteristics of low temperature helium in conventional and hybrid CICCS. Pressure drop measurements for both NET and CEA conductors have been conducted, using low temperature helium and liquid nitrogen to obtain a range of Reynolds numbers. The results are correlated with classical friction factor and Reynolds number analysis. The flow impedance reduction of the CEA conductor is described by measures of a developed flow model. Thermally induced flow in the CEA conductor has been studied with an inductive heating method. The induced velocity in the central channel is measured by a Pitot tube with steady state Reynolds number up to {approximately}7000. The transient pressure wave propagation has been recorded with pressure transducers placed equally along the conductor. The supercritical helium temperature in the central channel has been measured with the thermometer probe. However, the reduction of the central channel area significantly affects the overall thermal hydraulic characteristics of the conductor. The results suggest the importance of the central channel. A transient heat transfer experiment studied the.transverse heat transfer mechanism in the CEA conductor. The temperatures in the central channel and bundle region were measured with different sized heat pulses. The results are discussed in terms of a heat transfer model which is based upon the communication of the helium in the central channel and bundle.
Fluid dynamics of supercritical hellium within cable-in-conduit conductors. Progress report
Van Sciver, S.W.
The enclosed report summarizes work carried out under DOE/MFE Support, during the past four years. Emphasis is placed on progress within the last year. Results of experiments on pressure drop and heat transfer within several Cable-in-Conduit Conductors are described. These results are compared to models for flow in similar geometrics. The work provides a basis for design of magnets using the CIC Conductor Concept.
Fluid dynamics of supercritical hellium within cable-in-conduit conductors
Van Sciver, S.W.
The enclosed report summarizes work carried out under DOE/MFE Support, during the past four years. Emphasis is placed on progress within the last year. Results of experiments on pressure drop and heat transfer within several Cable-in-Conduit Conductors are described. These results are compared to models for flow in similar geometrics. The work provides a basis for design of magnets using the CIC Conductor Concept.
Doped Y.sub.2O.sub.3 buffer layers for laminated conductors
Paranthaman, Mariappan Parans (Knoxville, TN) [Knoxville, TN; Schoop, Urs (Westborough, MA) [Westborough, MA; Goyal, Amit (Knoxville, TN) [Knoxville, TN; Thieme, Cornelis Leo Hans (Westborough, MA) [Westborough, MA; Verebelyi, Darren T. (Oxford, MA) [Oxford, MA; Rupich, Martin W. (Framingham, MA) [Framingham, MA
A laminated conductor includes a metallic substrate having a surface, a biaxially textured buffer layer supported by the surface of the metallic substrate, the biaxially textured buffer layer comprising Y.sub.2O.sub.3 and a dopant for blocking cation diffusion through the Y.sub.2O.sub.3, and a biaxially textured conductor layer supported by the biaxially textured buffer layer.
Qualification of the US made conductors for ITER TF magnet system
Martovetsky, N; Hatfield, D; Miller, J; Bruzzone, P; Stepanov, B; Seber, B
The US Domestic Agency (USDA) is one of the six suppliers of the TF conductor for ITER. In order to qualify conductors according to ITER requirements we prepared several lengths of the CICC and short samples for testing in the SULTAN facility in CRPP, Switzerland. We also fully characterized the strands that were used in these SULTAN samples. Fabrication experience and test results are presented and discussed.
atmospheric transparency studies: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
pressures lower than 0.1 bar, transparency to thermal radiation allows shortwave heating to dominate, creating a stratosphere. At higher pressures, atmospheres become...
Net Requirements Transparency Process for Slice/Block Customers
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
4, 2012 Net Requirements Transparency Process for SliceBlock Customers Description of Changes and a Response to Comments September 24, 2012 Background and Description of Changes:...
Sorted Single-Walled Carbon Nanotube Films for Transparent Electrodes...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Sorted Single-Walled Carbon Nanotube Films for Transparent Electrodes in Organic Solar Cells Home > Research > ANSER Research Highlights > Sorted Single-Walled Carbon Nanotube...
Electrically tunable terahertz wave modulator based on complementary metamaterial and graphene
He, Xun-jun, E-mail: email@example.com; Li, Teng-yue; Wang, Lei; Wang, Jian-min; Jiang, Jiu-xing [Department of Electronic Science and technology, School of Applied Sciences, Harbin University of Science and Technology, Harbin 150080 (China); Yang, Guo-hui; Meng, Fan-yi; Wu, Qun [Department of Electronic and Communications Engineering, School of Electronic Information Engineering, Harbin Institute of Technology, Harbin 150001 (China)
In this paper, we design and numerically demonstrate an electrically controllable light-matter interaction in a hybrid material/metamaterial system consisting of an artificially constructed cross cut-wire complementary metamaterial and an atomically thin graphene layer to realize terahertz (THz) wave modulator. By applying a bias voltage between the metamaterial and the graphene layer, this modulator can dynamically control the amplitude and phase of the transmitted wave near 1.43 THz. Moreover, the distributions of current density show that this large modulation depth can be attributed to the resonant electric field parallel to the graphene sheet. Therefore, the modulator performance indicates the enormous potential of graphene for developing sophisticated THz communication systems.
A non-resonant dielectric metamaterial for enhancement of thin-film solar cells
Omelyanovich, Mikhail; Simovski, Constantin
Recently, we have suggested dielectric metamaterial composed as an array of submicron dielectric spheres located on top of an amorphous thin-film solar cell. We have theoretically shown that this metamaterial can decrease the reflection and simultaneously can suppress the transmission through the photovoltaic layer because it transforms the incident plane wave into a set of focused light beams. This theoretical concept has been strongly developed and experimentally confirmed in the present paper. Here we consider the metamaterial for oblique angle illumination, redesign the solar cell and present a detailed experimental study of the whole structure. In contrast to our precedent theoretical study we show that our omnidirectional light-trapping structure may operate better than the optimized flat coating obtained by plasma-enhanced chemical vapor deposition.
Switchable wavelength-selective and diffuse metamaterial absorber/emitter with a phase transition spacer layer
Wang, Hao; Yang, Yue; Wang, Liping, E-mail: email@example.com [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, Arizona 85287 (United States)
We numerically demonstrate a switchable metamaterial absorber/emitter by thermally turning on or off the excitation of magnetic resonance upon the phase transition of vanadium dioxide (VO{sub 2}). Perfect absorption peak exists around the wavelength of 5??m when the excitation of magnetic resonance is supported with the insulating VO{sub 2} spacer layer. The wavelength-selective absorption is switched off when the magnetic resonance is disabled with metallic VO{sub 2} that shorts the top and bottom metallic structures. The resonance wavelength can be tuned with different geometry, and the switchable metamaterial exhibits diffuse behaviors at oblique angles. The results would facilitate the design of switchable metamaterials for active control in energy and sensing applications.
Transparent conducting thin films for spacecraft applications
Perez-Davis, M.E.; Malave-Sanabria, T.; Hambourger, P.; Rutledge, S.K.; Roig, D.; Degroh, K.K.; Hung, C.
Transparent conductive thin films are required for a variety of optoelectronic applications: automotive and aircraft windows, and solar cells for space applications. Transparent conductive coatings of indium-tin-oxide (ITO)-magnesium fluoride (MgF2) and aluminum doped zinc oxide (AZO) at several dopant levels are investigated for electrical resistivity (sheet resistance), carrier concentration, optical properties, and atomic oxygen durability. The sheet resistance values of ITO-MgF2 range from 10[sup 2] to 10[sup 11] ohms/square, with transmittance of 75 to 86 percent. The AZO films sheet resistances range from 10[sup 7] to 10[sup 11] ohms/square with transmittances from 84 to 91 percent. It was found that in general, with respect to the optical properties, the zinc oxide (ZnO), AZO, and the high MgF2 content ITO-MgF2 samples, were all durable to atomic oxygen plasma, while the low MgF2 content of ITO-MgF2 samples were not durable to atomic oxygen plasma exposure.
Transparent self-cleaning dust shield
Mazumder, Malay K.; Sims, Robert A.; Wilson, James D.
A transparent electromagnetic shield to protect solar panels and the like from dust deposition. The shield is a panel of clear non-conducting (dielectric) material with embedded parallel electrodes. The panel is coated with a semiconducting film. Desirably the electrodes are transparent. The electrodes are connected to a single-phase AC signal or to a multi-phase AC signal that produces a travelling electromagnetic wave. The electromagnetic field produced by the electrodes lifts dust particles away from the shield and repels charged particles. Deposited dust particles are removed when the electrodes are activated, regardless of the resistivity of the dust. Electrostatic charges on the panel are discharged by the semiconducting film. When used in conjunction with photovoltaic cells, the power for the device may be obtained from the cells themselves. For other surfaces, such as windshields, optical windows and the like, the power must be derived from an external source. One embodiment of the invention employs monitoring and detection devices to determine when the level of obscuration of the screen by dust has reached a threshold level requiring activation of the dust removal feature.
Combined complex Doppler and Cherenkov effect in left-handed metamaterials
Ziemkiewicz, David
We derive the formula of the complex Doppler shift in a two-dimensional, dispersive metamaterial and we show that a moving, monochromatic radiation source generates multiple frequency modes. The role of the group velocity is stressed and the Doppler shifted radiation field exhibits features of the Cherenkov effect. The presented theory is also applicable to the case of a moving, nonoscillating charge and explains many peculiar characteristics of the Cherenkov radiation in lefthanded metamaterials such as the backward direction of power emission, the constant radiation angle and the lack of velocity threshold.
Spatiotemporal electromagnetic soliton and spatial ring formation in nonlinear metamaterials
Zhang Jinggui; Wen Shuangchun; Xiang Yuanjiang; Wang Youwen; Luo Hailu [Key Laboratory for Micro/Nano Optoelectronic Devices of Ministry of Education, School of Computer and Communication, Hunan University, Changsha 410082 (China)
We present a systematic investigation of ultrashort electromagnetic pulse propagation in metamaterials (MMs) with simultaneous cubic electric and magnetic nonlinearity. We predict that spatiotemporal electromagnetic solitons may exist in the positive-index region of a MM with focusing nonlinearity and anomalous group velocity dispersion (GVD), as well as in the negative-index region of the MM with defocusing nonlinearity and normal GVD. The experimental circumstances for generating and manipulating spatiotemporal electromagnetic solitons can be created by elaborating appropriate MMs. In addition, we find that, in the negative-index region of a MM, a spatial ring may be formed as the electromagnetic pulse propagates for focusing nonlinearity and anomalous GVD; while the phenomenon of temporal splitting of the electromagnetic pulse may appear for the same case except for the defocusing nonlinearity. Finally, we demonstrate that the nonlinear magnetization makes the sign of effective electric nonlinear effect switchable due to the combined action of electric and magnetic nonlinearity, exerting a significant influence on the propagation of electromagnetic pulses.
Perception-Based Transparency Optimization for Direct Volume Rendering
Chen, Wei
Perception-Based Transparency Optimization for Direct Volume Rendering Ming-Yuen Chan, Student. Perceptual enhancement on transparent layers in direct volume rendered images: a CT head dataset with layered structures (left); layers are enhanced using our proposed rendering optimization method (right). Abstract
Rollins, Andrew M.
DEGRADATION OF TRANSPARENT CONDUCTIVE OXIDES: MECHANISTIC INSIGHTS AND INTERFACIAL ENGINEERING;Degradation of Transparent Conductive Oxides: Mechanistic insights and Interfacial engineering Case Western;Dedicated to the science and engineering of photovoltaics, in an effort to make a better world. #12;Table
High carrier concentration p-type transparent conducting oxide films
Yan, Yanfa; Zhang, Shengbai
A p-type transparent conducting oxide film is provided which is consisting essentially of, the transparent conducting oxide and a molecular doping source, the oxide and doping source grown under conditions sufficient to deliver the doping source intact onto the oxide.
Matched slow pulses using double electromagnetically induced transparency
Lvovsky, Alexander
Matched slow pulses using double electromagnetically induced transparency Andrew MacRae,* Geoff, 2008 We implement double electromagnetically induced transparency (DEIT) in rubidium vapor using Optical Society of America OCIS codes: 270.1670, 270.5585, 190.5530. Electromagnetically induced
Eyo: Device-Transparent Personal Storage Jacob Strauss
Gummadi, Ramakrishna
Eyo: Device-Transparent Personal Storage Jacob Strauss Justin Mazzola Paluska Chris Lesniewski on multiple personal devices, each of which typically offers a storage management interface oblivious. This paper presents Eyo, a novel personal storage sys- tem that provides device transparency: a user can
Integrated broadband bowtie antenna on transparent substrate
Zhang, Xingyu; Subbaraman, Harish; Zhan, Qiwen; Pan, Zeyu; Chung, Chi-jui; Yan, Hai; Chen, Ray T
The bowtie antenna is a topic of growing interest in recent years. In this paper, we design, fabricate, and characterize a modified gold bowtie antenna integrated on a transparent glass substrate. We numerically investigate the antenna characteristics, specifically its resonant frequency and enhancement factor. We simulate the dependence of resonance frequency on bowtie geometry, and verify the simulation results through experimental investigation, by fabricating different sets of bowtie antennas on glass substrates utilizing CMOS compatible processes and measuring their resonance frequencies. Our designed bowtie antenna provides a strong broadband electric field enhancement in its feed gap. The far-field radiation pattern of the bowtie antenna is measured, and it shows dipole-like characteristics with large beam width. Such a broadband antenna will be useful for a myriad of applications, ranging from wireless communications to electromagnetic wave detection.
Gravitational Lensing Characteristics of the Transparent Sun
Bijunath Patla; Robert J. Nemiroff
The transparent Sun is modeled as a spherically symmetric and centrally condensed gravitational lens using recent Standard Solar Model (SSM) data. The Sun's minimum focal length is computed to a refined accuracy of 23.5 +/- 0.1 AU, just beyond the orbit of Uranus. The Sun creates a single image of a distant point source visible to observers inside this minimum focal length and to observers sufficiently removed from the line connecting the source through the Sun's center. Regions of space are mapped where three images of a distant point source are created, along with their associated magnifications. Solar caustics, critical curves, and Einstein rings are computed and discussed. Extremely high gravitational lens magnifications exist for observers situated so that an angularly small, unlensed source appears near a three-image caustic. Types of radiations that might undergo significant solar lens magnifications as they can traverse the core of the Sun, including neutrinos and gravitational radiation, are discussed.
Heavy duty insulator assemblies for 500-kV bulk power transmission line with large diameter octagonalbundled conductor
Tsujimoto, K.; Hayase, I.; Hirai, J.; Inove, M.; Naito, K.; Yukino, T.
This paper describes the design procedure and the results of field tests on mechanical performances of insulator assemblies newly developed to support octagonal-bundled conductors for 500-kV bulk power transmission. Taking account of conductor-motion-induced peak tensile load, fatigue, torsional torque and others, a successful design has been achieved in two prototype assemblies for such heavy mechanical duties as encountered during conductor galloping or swing. This has been proved throughout three years of the field tests.
Carbon Nanotube Assemblies for Transparent Conducting Electrodes
Garrett, Matthew P [ORNL] [ORNL; Gerhardt, Rosario [ORNL] [ORNL
The goal of this chapter is to introduce readers to the fundamental and practical aspects of nanotube assemblies made into transparent conducting networks and discuss some practical aspects of their characterization. Transparent conducting coatings (TCC) are an essential part of electro-optical devices, from photovoltaics and light emitting devices to electromagnetic shielding and electrochromic widows. The market for organic materials (including nanomaterials and polymers) based TCCs is expected to show a growth rate of 56.9% to reach nearly 20.3billionin2015,whilethemarketfortraditionalinorganictransparentelectronicswillexperiencegrowthwithratesof6.7103 billion in 2015. Emerging flexible electronic applications have brought additional requirements of flexibility and low cost for TCC. However, the price of indium (the major component in indium tin oxide TCC) continues to increase. On the other hand, the price of nanomaterials has continued to decrease due to development of high volume, quality production processes. Additional benefits come from the low cost, nonvacuum deposition of nanomaterials based TCC, compared to traditional coatings requiring energy intensive vacuum deposition. Among the materials actively researched as alternative TCC are nanoparticles, nanowires, and nanotubes with high aspect ratio as well as their composites. The figure of merit (FOM) can be used to compare TCCs made from dissimilar materials and with different transmittance and conductivity values. In the first part of this manuscript, we will discuss the seven FOM parameters that have been proposed, including one specifically intended for flexible applications. The approach for how to measure TCE electrical properties, including frequency dependence, will also be discussed. We will relate the macroscale electrical characteristics of TCCs to the nanoscale parameters of conducting networks. The fundamental aspects of nanomaterial assemblies in conducting networks will also be addressed. We will review recent literature on TCCs composed of carbon nanotubes of different types in terms of the FOM.
Toward photonic-crystal metamaterials: Creating magnetic emitters in photonic crystals
explore the possibility of designing photonic crystals to act as magnetic metamaterials: structures the constituents of natural para- and ferromagnetic materials, these synthetic magnetic emitters can be designed, quantitatively demonstrating that point-defect modes can be designed to have a magnetic character. We choose
Electromagnetic parameter retrieval from inhomogeneous metamaterials D. R. Smith,1,2,
Soukoulis, Costas
Electromagnetic parameter retrieval from inhomogeneous metamaterials D. R. Smith,1,2, * D. C. Vier: 10.1103/PhysRevE.71.036617 PACS number s : 41.20. q, 42.70. a I. INTRODUCTION A. Effective media
Controlling terahertz waves with meta-materials and photonic bandgap structures
Shchegolkov, Dmitry [Los Alamos National Laboratory; Azad, Abul [Los Alamos National Laboratory; O' Hara, John F [Los Alamos National Laboratory; Moody, Nathan A [Los Alamos National Laboratory; Simakov, Evgenya I [Los Alamos National Laboratory
We will describe research conducted at Los Alamos National Laboratory towards developing components for controlling terahertz waves. We employ meta-materials and, particularly, meta-films, as very compact absorbers for controlling quasioptical beams. We believe that dielectric photonic bandgap structures could replace ordinary metal waveguide devices at THz, since metal structures become extremely lossy in this frequency range.
Pneumatically switchable graded index metamaterial lens I. E. Khodasevych,1,2,a)
the material can pose a challenge for practical realiza- tion. The engineered refractive indices of metamaterials can be varied to a much greater extent than is possible with natu- ral materials by adjusting to alter the electromagnetic signature of a lens when it is not in use for stealth purposes. Tunable lenses
Parametric investigation and analysis of fishnet metamaterials in the microwave regime
- ward step was started from the work by Podolskiy et al. [15], in which a resonant magnetic response simulations the electromagnetic response of microwave fishnet metamaterials and its dependence on the system description of the fishnet design and reveals a left-handed response with high transmittance for a wide
Subwavelength silicon through-hole arrays as an all-dielectric broadband terahertz gradient index metamaterial
Park, Sang-Gil; Jeong, Ki-Hun, E-mail: firstname.lastname@example.com [Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); KAIST Institute for Optical Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Lee, Kanghee; Han, Daehoon; Ahn, Jaewook [KAIST Institute for Optical Science and Technology, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Department of Physics, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)
Structuring at subwavelength scales brings out artificial media with anomalous optical features called metamaterials. All-dielectric metamaterials have high potential for practical applications over the whole electromagnetic spectrum owing to low loss and optical isotropy. Here, we report subwavelength silicon through-hole arrays as an all-dielectric gradient index metamaterial with broadband THz operation. The unit cell consists of a single subwavelength through-hole on highly resistive monocrystalline silicon. Depending on the fill-factor and period, the effective index was linearly modulated at 0.31.6 THz. The experimental results also demonstrate silicon gradient refractive index (Si-GRIN) lenses with parabolic index profiles through the spatial modification of a single unit cell along the radial direction. Si-GRIN lenses either focus 0.41.6 THz beam to the diffraction-limit or serve as a flat and thin solid immersion lens on the backside of THz photoconductive antenna for highly efficient pulse extraction. This all-dielectric gradient index metamaterial opens up opportunities for integrated THz GRIN optics.
A microwave metamaterial with integrated power harvesting functionality Allen M. Hawkes,a)
Cummer, Steven A.
A microwave metamaterial with integrated power harvesting functionality Allen M. Hawkes power harvesting, the focus of this work. Power harvesting devices convert one type of energy to another, typically converting to a direct current (DC) signal. Many types of energy can be harvested, from acoustic
Casimir Energy, Holographic Dark Energy and Electromagnetic Metamaterial Mimicking de Sitter
Miao Li; Rong-Xin Miao; Yi Pang
We compute the Casimir energy of the photon field in a de Sitter space and find it to be proportional to the size of the horizon, the same form of the holographic dark energy. We suggest to make metamaterials to mimic de Sitter space in laboratory and measure the predicted Casimir energy.
Metamaterial Perfect Absorber Based Hot Electron Photodetection Wei Li and Jason Valentine*
Simaan, Nabil
be harnessed in the form of hot electrons for use in photocatalysis, photovoltaics, and photodetectors, and photocatalysis systems. KEYWORDS: Plasmonics, metamaterial perfect absorber, hot electrons, infrared including photo- detection,11-20 photovoltaic devices,21,22 photocatalysis,23-26 and surface imaging.27
Cryogenic temperatures as a path toward high-Q terahertz metamaterials Ranjan Singh,1,2
Oklahoma State University
,3 Jiaguang Han,4 Carsten Rockstuhl,5 Jianqiang Gu,1,3 and Weili Zhang1,a 1 School of Electrical and Computer of Optoelectronics Information and Technical Science (Ministry of Education), Tianjin 300072, People's Republic to be a promising path toward low-loss metamaterials since nonradiative losses are strongly suppressed due to higher
2011 Annual Health Physics Report for the HEU transparency Program
Radev, R
During the 2008 calendar year, Lawrence Livermore National Laboratory (LLNL) provided health physics support for the Highly Enriched Uranium (HEU) Transparency Program for external and internal radiation protection. They also provided technical expertise related to BDMS radioactive sources and Russian radiation safety regulatory compliance. For the calendar year 2008, there were 158 person-trips that required dose monitoring of the U.S. monitors. Of the 158 person-trips, 148 person-trips were SMVs and 10 person-trips were Transparency Monitoring Office (TMO) trips. There were 6 monitoring visits by TMO monitors to facilities other than UEIE and 8 to UEIE itself. There were three monitoring visits (source changes) that were back-to-back with a total of 24 monitors. LLNL's Hazard Control Department laboratories provided the dosimetry services for the HEU Transparency monitors. In 2008, the HEU Transparency activities in Russia were conducted in a radiologically safe manner for the HEU Transparency monitors in accordance with the expectations of the HEU Transparency staff, NNSA and DOE. The HEU Transparency now has thirteen years of successful experience in developing and providing health and safety support in meeting its technical objectives.
Insulated conductor temperature limited heater for subsurface heating coupled in a three-phase WYE configuration
Vinegar, Harold J. (Bellaire, TX); Sandberg, Chester Ledlie (Palo Alto, CA)
A heating system for a subsurface formation is described. The heating system includes a first heater, a second heater, and a third heater placed in an opening in the subsurface formation. Each heater includes: an electrical conductor; an insulation layer at least partially surrounding the electrical conductor; and an electrically conductive sheath at least partially surrounding the insulation layer. The electrical conductor is electrically coupled to the sheath at a lower end portion of the heater. The lower end portion is the portion of the heater distal from a surface of the opening. The first heater, the second heater, and the third heater are electrically coupled at the lower end portions of the heaters. The first heater, the second heater, and the third heater are configured to be electrically coupled in a three-phase wye configuration.
Arithmetic and Differential Swan Conductors of rank one representations with finite local monodromy
Chiarellotto, Bruno
We consider a complete discrete valuation field of characteristic p, with possibly non perfect residue field. Let V be a continuous representation with finite local monodromy of its absolute Galois group. We will prove that the Arithmetic Swan conductor of V (defined after Kato in [Kat89] which fits in the more general theory of [AS02] and [AS06]) coincides with the Differential Swan conductor of the associated differential module $D^{\\dag}(V)$ defined by Kedlaya in [Ked]. This construction is a generalization to the non perfect residue case of the Fontaine's formalism as presented in [Tsu98a]. Our method of proof will allow us to give a new interpretation of the Refined Swan Conductor.
Information sources for transparency measures at sensitive facilities
Stanbro, W.D.; Olinger, C.T.; Close, D.A.; Kniss, B.
The concept of transparency stems from a desire to assure other parties that some action such as the dismantlement of a weapons system is taking place while avoiding the intrusiveness, complexity, and lengthy negotiations associated with formal verification measures. By their nature, transparency measures may fall short of providing the degree of confidence associated with arms control treaties, such as INF or START, but can be more quickly and easily implemented. This paper discusses information sources that could form the basis of transparency measures at sensitive facilities.
Information sources for transparency measures at sensitive facilities
Stanbro, W.D.; Olinger, C.T.; Close, D.A.; Kniss, B. [Los Alamos National Lab., NM (United States)
The concept of transparency stems from a desire to assure other parties that some action such as the dismantlement of a weapons system is taking place while avoiding the intrusiveness, complexity, and lengthy negotiations associated with formal verification measures. By their nature, transparency measures may fall short of providing the degree of confidence associated with arms control treaties, such as INF or START, but can be more quickly and easily implemented. This paper discusses information sources that could form the basis of transparency measures at sensitive facilities.
Analysis of Conductor Impedances Accounting for Skin Effect and Nonlinear Permeability
Perkins, M P; Ong, M M; Brown, C G; Speer, R D
It is often necessary to protect sensitive electrical equipment from pulsed electric and magnetic fields. To accomplish this electromagnetic shielding structures similar to Faraday Cages are often implemented. If the equipment is inside a facility that has been reinforced with rebar, the rebar can be used as part of a lighting protection system. Unfortunately, such shields are not perfect and allow electromagnetic fields to be created inside due to discontinuities in the structure, penetrations, and finite conductivity of the shield. In order to perform an analysis of such a structure it is important to first determine the effect of the finite impedance of the conductors used in the shield. In this paper we will discuss the impedances of different cylindrical conductors in the time domain. For a time varying pulse the currents created in the conductor will have different spectral components, which will affect the current density due to skin effects. Many construction materials use iron and different types of steels that have a nonlinear permeability. The nonlinear material can have an effect on the impedance of the conductor depending on the B-H curve. Although closed form solutions exist for the impedances of cylindrical conductors made of linear materials, computational techniques are needed for nonlinear materials. Simulations of such impedances are often technically challenging due to the need for a computational mesh to be able to resolve the skin depths for the different spectral components in the pulse. The results of such simulations in the time domain will be shown and used to determine the impedances of cylindrical conductors for lightning current pulses that have low frequency content.
Investigation of conductor swinging by wind and its application for design of compact transmission line
Tsujimoto, K.; Fujii, K.; Kubokawa, H.; Okomura, T.; Simojima, K.; Yoshioka, V.
In Japan it has recently become necessary to shorten the interphase spacing in overhead transmission lines because of land limitations and economical considerations. In this connection, the authors have attempted to analyze, in-depth, the possibilities of shortened interphase spacing via conductor swinging caused by wind effects: one of the important factors in the design of more compact overhead lines. This paper describes not only the investigative results of conductor swinging that were obtained both through computer simulation and in 3 years of full scale field line testing, but also design methodology for compact overhead lines based on these results.
Casimir force calculations near the insulator-conductor transition in gold thin films
R. Esquivel-Sirvent
We present theoretical calculations of the Casimir force for Au thin films near the insulator-conductor transition that has been observed experimentally. The dielectric function of the Au thin films is described by the Drude-Smith model. The parameters needed to model the dielectric function such as the relaxation time, plasma frequency and the backscattering constant depend on the thickness of the film. The Casimir force decreases as the film thickness decreases until it reaches a minimum after which the force increases again. The minimum of the force coincides with the critical film thickness where a percolation conductor-insulator occurs.
Temperature control of some metallic conductors in the region of the melting point
Rahman, Arifur
TEMPERATURE CONTROL OF SOME METALLIC CONDUCTORS IN THE REGION OF THE MELTING POINT A Thesis by Ari fur Rahman Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 1961 Ma)or Sub)ect: Electrical Engineering TEMPE~ CONTROL OF SOME METALLIC CONDUCTORS IN THE REGION OF THE MELTING POINT 4 4 E 4 K 0 5 0 A Thesis by Arifur Rahman Approved as to style and content by: (Ch...
PHYSICAL REVIEW B VOLUME 47, NUMBER 4 15 JANUARY 1993-II Nonlinear voltages in multiple-lead coherent conductors
Presilla, Carlo
PHYSICAL REVIEW B VOLUME 47, NUMBER 4 15 JANUARY 1993-II Nonlinear voltages in multiple-lead to study multiple-lead coherent conductors in the case of finite applied voltages. In this framework we discuss the transverse voltage arising in a four-lead conductor with two symmetric biased leads. Recently
Method and system for evaluating integrity of adherence of a conductor bond to a mating surface of a substrate
Telschow, K.L.; Siu, B.K.
A method of evaluating integrity of adherence of a conductor bond to a substrate includes: (a) impinging a plurality of light sources onto a substrate; (b) detecting optical reflective signatures emanating from the substrate from the impinged light; (c) determining location of a selected conductor bond on the substrate from the detected reflective signatures; (d) determining a target site on the selected conductor bond from the detected reflective signatures; (e) optically imparting an elastic wave at the target site through the selected conductor bond and into the substrate; (f) optically detecting an elastic wave signature emanating from the substrate resulting from the optically imparting step; and (g) determining integrity of adherence of the selected conductor bond to the substrate from the detected elastic wave signature emanating from the substrate. A system is disclosed which is capable of conducting the method. 13 figs.
Directed Social Queries With Transparent User Models Saiph Savage1
California at Santa Barbara, University of
.forbes@cs, holl@cs}.ucsb.edu 2 Universidad Nacional AutÇonoma de MÇexico {rodrigosavage@comunidad, norma?" Computers Music Pets Cooking Transparent Interface Socially Aware Interface "Mexican Food and Salsa Dancing
Acoustical transparency induced by local resonance in Bragg bandgaps
Yu, Gaokun; Wang, Xinlong, E-mail: firstname.lastname@example.com [Key Laboratory of Modern Acoustics and Institute of Acoustics, Nanjing University, Nanjing 210093 (China)
We show that sound waves can resonantly transmit through Bragg bandgaps in an acoustical duct periodically attached with an array of Helmholtz resonators, forming within the normally forbidden band a transparency window with group velocity smaller than the normal speed of sound. The transparency occurs for the locally resonant frequency so much close to the Bragg one that both the local-resonance-induced bandgap and the Bragg one heavily overlap with each other. The phenomenon seems an acoustical analog of the well-known electromagnetically induced transparency by quantum interference. Different from the Fano-like interference explanation, we also provide a mechanism for the transparency window phenomenon which makes it possible to extend the phenomenon in general.
Device Transparency: a New Model for Mobile Storage
Strauss, Jacob A.
This paper proposes a new storage model, device transparency, in which users view and manage their entire data collection from any of their devices, even from disconnected storage-limited devices holding only a subset of ...
DMTCP: Transparent Checkpointing for Cluster Computations and the Desktop
Arya, Kapil
DMTCP (Distributed MultiThreaded CheckPointing) is a transparent user-level checkpointing package for distributed applications. Checkpointing and restart is demonstrated for a wide range of over 20 well known applications, ...
alternative transparent electrodes: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
large fraction of power incident on a curved primary mirror using an on-axis secondary mirror Kik, Pieter 7 Electrospun Metal Nanofiber Webs as High-Performance Transparent...
al transparent conducting: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Reduction of graphene oxide films on Al foil for hybrid transparent conductive film applications...
Net Requirements Transparency Process for Slice/Block and Block...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
3 As part of its Net Requirements Transparency process, on July 31, 2013 BPA published the SliceBlock and Block customers' FY2012 and forecast FY2014 Total Retail Load (TRL) and...
Slip casting nano-particle powders for making transparent ceramics
Kuntz, Joshua D. (Livermore, CA); Soules, Thomas F. (Livermore, CA); Landingham, Richard Lee (Livermore, CA); Hollingsworth, Joel P. (Oakland, CA)
A method of making a transparent ceramic including the steps of providing nano-ceramic powders in a processed or unprocessed form, mixing the powders with de-ionized water, the step of mixing the powders with de-ionized water producing a slurry, sonifing the slurry to completely wet the powder and suspend the powder in the de-ionized water, separating very fine particles from the slurry, molding the slurry, and curing the slurry to produce the transparent ceramic.
Coupled-resonator-induced transparency with a squeezed vacuum
Ke Di; Changde Xie; Jing Zhang
We present the first experimental observation of quantum fluctuation spectra in two coupled optical cavities with an injected squeezed vacuum light. The quadrature components of the reflected squeezed vacuum spectra are measured by phase sensitive homodyne detector. The experimental results demonstrate coupled-resonator-induced transparency in the quantum regime, in which electromagnetically-induced-transparency-like characteristic of the absorption and dispersion properties of the coupled optical cavities determines the line-shape of the reflected quantum noise spectra.
Realistic hadronic matrix element approach to color transparency
Jennings, B.K. (TRIUMF, Vancouver, British Columbia, V6T 2A3 (Canada)); Miller, G.A. (Physics Department, FM-15, University of Washington, Seattle, Washington 98195 (United States))
Color transparency occurs if a small-sized wave packet, formed in a high momentum transfer process, escapes the nucleus before expanding. The time required for the expansion depends on the masses of the baryonic components of the wave packet. Measured proton diffractive dissociation and electron deep inelastic scattering cross sections are used to examine and severely constrain the relevant masses. These constraints allow significant color transparency effects to occur at experimentally accessible momentum transfers.
Color transparency and Landshoff multiple-scattering processes
Botts, J. (Department of Physics, FM-15, University of Washington, Seattle, Washington (USA))
In the following, the leading and nonleading contributions to fixed angle hadron-hadron elastic scattering are included in a qualitative analysis of {ital T}({ital s}), the transparency of {ital pN} quasielastic scattering. A simple model is given to predict the center-of-mass energies at which a target nuclei will become transparent to hard- and triple- (Landshoff-) scattered protons.
NEPA Success Stories: Celebrating 40 Years of Transparency and Open Government
Broader source: Energy.gov [DOE]
NEPA Success Stories: Celebrating 40 Years of Transparency and Open Government, Environmental Law Institute, 2010.
Nuclear transparency in 90c.m. quasielastic A,,p,2p... reactions
Christensen, Nelson
Nuclear transparency in 90c.m. ¯ quasielastic A,,p,2p... reactions J. Aclander,7 J. Alster,7 G Synchrotron of BNL to measure the nuclear transparency of nuclei measured in the A p,2p quasielastic of the energy dependence of the nuclear transparency. In E850 the angular dependence of the nuclear transparency
Is Opacity A Basic Feature? It's Not Transparent. Randall S. Birnkrant Jeremy M. Wolfe Hermie Mendoza
transparent objects and/or vice versa? Stimuli: Transparent bars were created by moving a virtual green filter Mendoza Brigham & Women's Hospital Brigham & Women's Hospital & Harvard Medical School OPAQUE You spotted as a basic feature? TRANSPARENT Exp. 1: Does an opaque object stick out among transparent objects and/or vice
Nuclear waste repository transparency technology test bed demonstrations at WIPP
Secretary of Energy, Bill Richardson, has stated that one of the nuclear waste legacy issues is ``The challenge of managing the fuel cycle's back end and assuring the safe use of nuclear power.'' Waste management (i.e., the back end) is a domestic and international issue that must be addressed. A key tool in gaining acceptance of nuclear waste repository technologies is transparency. Transparency provides information to outside parties for independent assessment of safety, security, and legitimate use of materials. Transparency is a combination of technologies and processes that apply to all elements of the development, operation, and closure of a repository system. A test bed for nuclear repository transparency technologies has been proposed to develop a broad-based set of concepts and strategies for transparency monitoring of nuclear materials at the back end of the fuel/weapons cycle. WIPP is the world's first complete geologic repository system for nuclear materials at the back end of the cycle. While it is understood that WIPP does not currently require this type of transparency, this repository has been proposed as realistic demonstration site to generate and test ideas, methods, and technologies about what transparency may entail at the back end of the nuclear materials cycle, and which could be applicable to other international repository developments. An integrated set of transparency demonstrations was developed and deployed during the summer, and fall of 1999 as a proof-of-concept of the repository transparency technology concept. These demonstrations also provided valuable experience and insight into the implementation of future transparency technology development and application. These demonstrations included: Container Monitoring Rocky Flats to WIPP; Underground Container Monitoring; Real-Time Radiation and Environmental Monitoring; Integrated level of confidence in the system and information provided. As the world's only operating deep geologic repository, the Waste Isolation Pilot Plant (WIPP) offers a unique opportunity to serve as an international cooperative test bed for developing and demonstrating technologies and processes in a fully operational repository system setting. To address the substantial national security implications for the US resulting from the lack of integrated, transparent management and disposition of nuclear materials at the back-end of the nuclear fuel and weapons cycles, it is proposed that WIPP be used as a test bed to develop and demonstrate technologies that will enable the transparent and proliferation-resistant geologic isolation of nuclear materials. The objectives of this initiative are to: (1) enhance public confidence in safe, secure geologic isolation of nuclear materials; (2) develop, test, and demonstrate transparency measures and technologies for the back-end of nuclear fuel cycle; and (3) foster international collaborations leading to workable, effective, globally-accepted standards for the transparent monitoring of geological repositories for nuclear materials. Test-bed activities include: development and testing of monitoring measures and technologies; international demonstration experiments; transparency workshops; visiting scientist exchanges; and educational outreach. These activities are proposed to be managed by the Department of Energy/Carlsbad Area Office (DOE/CAO) as part of The Center for Applied Repository and Underground Studies (CARUS).
High upper critical field and irreversibility field in MgB2 coated-conductor fibers
Eom, Chang Beom
the so-called "powder-in-tube" PIT technique with encourag- ing results.5Ù7 MgB2 conductors also promise horizontal surface of the susceptor heater and heated to 685Ù720 ¯C in H2 carrier gas during the depo- sition magnesium MeCp 2Mg , a carbon-containing metalorganic magnesium precursor, to the gas flow during
Instrumentation for Measurement of Strain Dependence of Nb3Sn Conductors National High Magnetic Field Laboratory
Weston, Ken
Instrumentation for Measurement of Strain Dependence of Nb3Sn Conductors National High Magnetic Field Laboratory Magnet Science and Technology, Florida State University An NHMFL User Collaboration Grants Program (UCGP) award is supporting students from the FAMU-FSU College of Engineering as part
Selected materials development for the 100 T magnet: Cu-Nb conductors with
Weston, Ken
Selected materials development for the 100 T magnet: Cu-Nb conductors with nanocomposite components (PBO) based composite for reinforcement Materials R&D for the 100-Tesla Pulsed Magnet Gregory S for this achievement was the long-term and painstaking research and development of high strength materials
Local Heating in Nanoscale Conductors Yu-Chang Chen, Michael Zwolak, and Massimiliano Di Ventra*
Zwolak, Michael
Local Heating in Nanoscale Conductors Yu-Chang Chen, Michael Zwolak, and Massimiliano Di Ventra Received October 2, 2003 ABSTRACT We report first-principles calculations of local heating in nanoscale heat dissipation, the single molecule heats less than the gold point contact. We also find that
Sum rules for inhomogeneous Coulomb fluids, and ideal conductor boundary conditions
Paris-Sud XI, UniversitÕ de
of particles interacting through Coulomb's law plus some short-range interaction (a hard core repulsion389 Sum rules for inhomogeneous Coulomb fluids, and ideal conductor boundary conditions B of an inhomogeneous Coulomb fluid is shown to obey a sum rule involving electrical multipole moments of arbitrary
Dielectric breakdown model for conductor-loaded and insulator-loaded composite materials P. Bergero,1
Peruani, Fernando
Dielectric breakdown model for conductor-loaded and insulator-loaded composite materials P. Bergero strength is highly desirable, and in the past years composite materials such as resin matrix filled- tors, and composites containing carbon black and titanium dioxide have recently been tested
Aluminum Stabilized NbTi Conductor Test Coil Design, Fabrication, and Test Results
Andreev, N.; Chlachidze, G.; Evbota, D.; Kashikhin, V.S.; Lamm, M.; Makarov, A.; Tartaglia, M.; /Fermilab; Nakamoto, T.; Ogitsu, T.; Tanaka, K.; Yamamoto, A.; /KEK, Tsukuba
A new generation of precision muon conversion experiments is planned at both Fermilab and KEK. These experiments will depend upon a complex set of solenoid magnets for the production, momentum selection and transport of a muon beam to a stopping target, and for tracking detector momentum analysis of candidate conversion electrons from the target. Baseline designs for the production and detector solenoids use NbTi cable that is heavily stabilized by an extruded high RRR aluminum jacket. A U.S.-Japan research collaboration has begun whose goal is to advance the development of optimized Al-NbTi conductors, gain experience with the technology of winding coils from this material, and test the conductor performance as modest length samples become available. For this purpose, a 'conductor test' solenoid with three coils was designed and built at Fermilab. A sample of the RIKEN Al-NbTi conductor from KEK was wound into a 'test' coil; this was sandwiched between two 'field' coils wound from doubled SSC cable, to increase the peak field on the RIKEN test coil. All three solenoid coils were epoxy impregnated, and utilized aluminum outer bandage rings to apply preload to the coils when cold. The design and fabrication details, and results of the magnet quench performance tests are presented and discussed.
Ion transport and storage of ionic liquids in ionic polymer conductor network composites
Heflin, Randy
, have shown a great promise for ap- plications in energy storage, conversion devices, and otherIon transport and storage of ionic liquids in ionic polymer conductor network composites Yang Liu,1, USA 6 Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, USA Received 24 February
Control of F\\"orster energy transfer in vicinity of metallic surfaces and hyperbolic metamaterials
Tumkur, Thejaswi U; Bonner, Carl E; Poddubny, Alexander N; Narimanov, Evgenii E; Noginov, Mikhail A
Optical cavities, plasmonic structures, photonic band crystals, interfaces, as well as, generally speaking, any photonic media with homogeneous or spatially inhomogeneous dielectric permittivity (including metamaterials) have local densities of photonic states, which are different from that in vacuum. These modified density of states environments are known to control both the rate and angular distribution of spontaneous emission. In the present study, we ask the question whether the proximity to metallic and metamaterial surfaces can affect other physical phenomena of fundamental and practical importance. We show that the same substrates and the same nonlocal dielectric environments that boost spontaneous emission, also inhibit F\\"orster energy transfer between donor and acceptor molecules doped into a thin polymeric film. This finding correlates with the fact that in dielectric media, the rate of spontaneous emission is proportional to the index of refraction n, while the rate of the donor-acceptor energy tr...
Realizing high-quality, ultra-large momentum states using semiconductor hyperbolic metamaterials
Campione, Salvatore; Luk, Ting S; Sinclair, Michael B
We employ both the effective medium approximation (EMA) and Bloch theory to compare the dispersion properties of semiconductor hyperbolic metamaterials (SHMs) at mid-infrared frequencies and metallic hyperbolic metamaterials (MHMs) at visible frequencies. This analysis reveals the conditions under which the EMA can be safely applied for both MHMs and SHMs. We find that the combination of precise nanoscale layering and the longer infrared operating wavelengths puts the SHMs well within the effective medium limit and, in contrast to MHMs, allows the attainment of very high photon momentum states. In addition, SHMs allow for new phenomena such as ultrafast creation of the hyperbolic manifold through optical pumping. In particular, we examine the possibility of achieving ultrafast topological transitions through optical pumping which can photo-dope appropriately designed quantum wells on the femtosecond time scale.
Highly-Efficient Selective Metamaterial Absorber for High-Temperature Solar Thermal Energy Harvesting
Wang, Hao; Mitchell, Arnan; Rosengarten, Gary; Phelan, Patrick; Wang, Liping
In this work, a metamaterial selective solar absorber made of nanostructured titanium gratings deposited on an ultrathin MgF2 spacer and a tungsten ground film is proposed and experimentally demonstrated. Normal absorptance of the fabricated solar absorber is characterized to be higher than 90% in the UV, visible and, near infrared (IR) regime, while the mid-IR emittance is around 20%. The high broadband absorption in the solar spectrum is realized by the excitation of surface plasmon and magnetic polariton resonances, while the low mid-IR emittance is due to the highly reflective nature of the metallic components. Further directional and polarized reflectance measurements show wide-angle and polarization-insensitive high absorption within solar spectrum. Temperature-dependent spectroscopic characterization indicates that the optical properties barely change at elevated temperatures up to 350{\\deg}C. The solar-to-heat conversion efficiency with the fabricated metamaterial solar absorber is predicted to be 78%...
The Transformation Design Method and Metamaterials: Tools to Realize Invisibility and Other Interesting Effects
Schurig, David (Duke University) [Duke University
I will explain how the transformation design method can yield a material specification that possesses the same electromagnetic behavior as a fairly general set of imagined space-time topologies. This method has been used to design invisibility cloaks, but the method is quite general and can be used to design a wide variety of interesting devices that guide, concentrate or shape electromagnetic fields in ways that would be difficult to manage with other design methodologies. Applications range from stealth to energy conversion and distribution to wireless communications to biomedical imaging. The drawback of the method is the complexity of the material specifications that it produces, which are in general anisotropic and inhomogeneous. Only with recent advances in the field of metamaterials can these specifications be realized. I will discuss how metamaterials accomplish this and what their limitations are, e.g. bandwidth, loss, frequency range etc. I will discuss in detail the recent implementation of an invisibility cloak in the microwave spectrum.
Controlling the Colour of Metals: Intaglio and Bas-Relief Metamaterials
Zhang, Jianfa; Papasimakis, Nikitas; Chen, Yifang; MacDonald, Kevin F; Zheludev, Nikolay I
The fabrication of indented ('intaglio') or raised ('bas-relief') sub-wavelength metamaterial patterns on a metal surface provides a mechanism for changing and controlling the colour of the metal without employing any form of chemical surface modification, thin-film coating or diffraction effects. We show that a broad range of colours can be achieved by varying the structural parameters of metamaterial designs to tune absorption resonances. This novel approach to the 'structural colouring' of pure metals offers great versatility and scalability for both aesthetic (e.g. jewellery design) and functional (e.g. sensors, optical modulators) applications. We focus here on visible colour but the concept can equally be applied to the engineering of metallic spectral response in other electromagnetic domains.
Tuning gain and bandwidth of traveling wave tubes using metamaterial beam-wave interaction structures
Lipton, Robert, E-mail: firstname.lastname@example.com; Polizzi, Anthony, E-mail: email@example.com [Department of Mathematics, Louisiana State University, Baton Rouge, Louisiana 70803-4918 (United States)
We employ metamaterial beam-wave interaction structures for tuning the gain and bandwidth of short traveling wave tubes. The interaction structures are made from metal rings of uniform cross section, which are periodically deployed along the length of the traveling wave tube. The aspect ratio of the ring cross sections is adjusted to control both gain and bandwidth. The frequency of operation is controlled by the filling fraction of the ring cross section with respect to the size of the period cell.
Selective buckling via states of self-stress in topological metamaterials
Jayson Paulose; Anne S. Meeussen; Vincenzo Vitelli
States of self-stress, tensions and compressions of structural elements that result in zero net forces, are ultimately responsible for the load-bearing ability of structures ranging from bridges to metamaterials with tunable mechanical properties. We exploit a class of recently introduced states of self-stress analogous to topological quantum states to sculpt localized buckling regions in the interior of periodic cellular metamaterials. Although the topological states of self stress arise in the linear response of an idealized mechanical frame of harmonic springs connected by freely-hinged joints, they leave a distinct signature in the nonlinear buckling behaviour of a cellular material built out of elastic beams with rigid joints. The salient feature of these localized buckling regions is that they are indistinguishable from their surroundings as far as material parameters or connectivity of their constituent elements are concerned. Furthermore, they are robust against a wide range of structural perturbations. We demonstrate the effectiveness of this topological design through analytical and numerical calculations as well as buckling experiments performed on two- and three-dimensional metamaterials built out of kagome lattices.
Tunable microwave impedance matching to a high impedance source using a Josephson metamaterial
Altimiras, Carles, E-mail: email@example.com; Parlavecchio, Olivier; Joyez, Philippe; Vion, Denis; Roche, Patrice; Esteve, Daniel; Portier, Fabien [Service de Physique de lEtat CondensÕ (CNRS URA 2464), IRAMIS, CEA Saclay, 91191 Gif-sur-Yvette (France)] [Service de Physique de lEtat CondensÕ (CNRS URA 2464), IRAMIS, CEA Saclay, 91191 Gif-sur-Yvette (France)
We report the efficient coupling of a 50??? microwave circuit to a high impedance conductor. We use an impedance transformer consisting of a ?/4 co-planar resonator whose inner conductor contains an array of superconducting quantum interference devices (SQUIDs), providing it with a tunable lineic inductance L?80??{sub 0}, resulting in a characteristic impedance Z{sub C}?1?k?. The impedance matching efficiency is characterized by measuring the shot noise power emitted by a dc biased tunnel junction connected to the resonator. We demonstrate matching to impedances in the 15 to 35?k? range with bandwidths above 100?MHz around a resonant frequency tunable between 4 and 6 GHz.
The effects of nonverbal behaviors exhibited by multiple conductors on the timbre, intonation, and perceptions of three university choirs, and assessed relationships between time spent in selected conductor behaviors and analysis of the choirs' performances
Grady, Melissa LeAnn
This investigation examined the effects of aggregate nonverbal behaviors exhibited by 10 videotaped conductors on the choral sound and perceptions of 3 university choirs (N = 61 choristers) as they sang from memory the same a cappella motet...
Matched Slow Pulses Using Double Electromagnetically Induced Transparency
Andrew MacRae; Geoff Campbell; A. I. Lvovsky
We implement double electromagnetically-induced transparency (double EIT) in rubidium vapor, using a tripod-shaped energy level scheme consisting of hyperfine and magnetic sublevels of the 5S1/2 to 5P1/2 transition. We show experimentally that through the use of double EIT one can control the contrast of transparency windows as well as group velocities of the two signal fields. In particular, the group velocities can be equalized, which holds promise to greatly enhance nonlinear optical interaction between these fields.
35.4 T Field Generated Using a Layer Wound Superconducting Coil Made of REBCO Coated Conductor
Weston, Ken
and round wire Bi-2212 are not be understood as mere competitors in field of HTS magnets but rather technology has caused a peak in the performance of HTS magnets. The two conductors featured here, REBCO
Comparison of gold- and graphene-based resonant nanostructures for terahertz metamaterials and an ultrathin graphene-based modulator
Shen, Nian-Hai [Ames Laboratory; Tassin, Philippe [Ames Laboratory; Koschny, Thomas [Ames Laboratory; Soukoulis, Costas M [Ames Laboratory
Graphene exhibits unique material properties, and in electromagnetic wave technology it raises the prospect of devices miniaturized down to the atomic length scale. Here we study split-ring resonator metamaterials made from graphene and we compare them to gold-based metamaterials. We find that graphene's huge reactive response derived from its large kinetic inductance allows for deeply subwavelength resonances, although its resonance strength is reduced due to higher dissipative loss damping and smaller dipole coupling. Nevertheless, tightly stacked graphene rings may provide for negative permeability and the electric dipole resonance of graphene meta-atoms turns out to be surprisingly strong. Based on these findings, we present a terahertz modulator based on a metamaterial with a multilayer stack of alternating patterned graphene sheets separated by dielectric spacers. Neighboring graphene flakes are biased against each other, resulting in modulation depths of over 75% at a transmission level of around 90%.
Magnetization measurements on multifilamentary Nb/sub 3/Sn and NbTi conductors
Ghosh, A.K.; Robins, K.E.; Sampson, W.B.
The effective filament size has been determined for a number of high current Nb/sub 3/Sn multifilamentary composites. In most cases it is much larger than the nominal filament size. For the smallest filaments (approx. 1 micron) the effective size can be as much as a factor of forty times the nominal size. Samples made by the internal tin, bronze route, and jelly roll methods have been examined with filaments in the range one to ten microns. Rate dependent magnetization and flux jumping have been observed in some cases. NbTi composites ranging in filament size from nine to two hundred microns and with copper to super-conductor ratios between 1.6:1 and 7:1 have been examined in the same apparatus. Low field flux jumping was only observed in conductors with very large filaments and relatively little stabilizing copper. 9 references, 6 figures, 3 tables.
Low AC Loss YBCO Coated Conductor Geometry by Direct Inkjet Printing
Rupich, Martin, Dr. [American Superconductor Corporation; Duckworth, Robert, Dr. [Oak Ridge National Laboratory
The second generation (2G) high temperature superconductors (HTS) wire offers potential benefits for many electric power applications, including ones requiring filamentized conductors with low ac loss, such as transformers and fault current limiters. However, the use of 2G wire in these applications requires the development of both novel multi-filamentary conductor designs with lower ac losses and the development of advanced manufacturing technologies that enable the low-cost manufacturing of these filamentized architectures. This Phase I SBIR project focused on testing inkjet printing as a potential low-cost, roll-to-roll manufacturing technique to fabricate potential low ac loss filamentized architectures directly on the 2G template strips.
Apparatus and method for measuring critical current properties of a coated conductor
Mueller, Fred M. (Los Alamos, NM); Haenisch, Jens (Dresden, DE)
The transverse critical-current uniformity in a superconducting tape was determined using a magnetic knife apparatus. A critical current I.sub.c distribution and transverse critical current density J.sub.c distribution in YBCO coated conductors was measured nondestructively with high resolution using a magnetic knife apparatus. The method utilizes the strong depression of J.sub.c in applied magnetic fields. A narrow region of low, including zero, magnetic field in a surrounding higher field is moved transversely across a sample of coated conductor. This reveals the critical current density distribution. A Fourier series inversion process was used to determine the transverse J.sub.c distribution in the sample.
Particle trap to sheath non-binding contact for a gas-insulated transmission line having a corrugated outer conductor
Fischer, William H. (Pittsburgh, PA)
A non-binding particle trap to outer sheath contact for use in gas insulated transmission lines having a corrugated outer conductor. The non-binding feature of the contact according to the teachings of the invention is accomplished by having a lever arm rotatably attached to a particle trap by a pivot support axis disposed parallel to the direction of travel of the inner conductor/insulator/particle trap assembly.
Heteroclite electrochemical stability of an I based Li7P2S8I superionic conductor
Rangasamy, Ezhiylmurugan [ORNL; Liu, Zengcai [ORNL; Gobet, Mallory [Hunter College of the City University of New York; Pilar, Kartik [Hunter College, City University of New York (CUNY); Sahu, Gayatri [ORNL; Greenbaum, Steve [Hunter College of the City University of New York; Liang, Chengdu [ORNL
Stability from Instability: A Li7P2S8I solid state Li-ion conductor derived from -Li3PS4 and LiI demonstrates exceptional electrochemical stability. The oxidation instability of I is subverted nullified via its incorporation into the coordinated structure. The inclusion of I also creates stability with metallic Li anode while simultaneously improving the interfacial kinetics. Low temperature membrane processability enables facile fabrication of dense membranes, making it suitable for industrial adoption.
Microstrip post production tuning bar error and compact resonators using negative refractive index metamaterials
Scher, Aaron David
. Such tuning bars are used in microwave circuit designs to allow the impedance or length of a microstrip line to be adjusted after fabrication. In general, the tuning bars are simply patterns of small, isolated sections of conductor adjacent to the thru line...
AC Loss Reduction in Filamentized YBCO Coated Conductors with Virtual Transverse Cross-cuts
Zhang, Yifei [ORNL; Duckworth, Robert C [ORNL; Ha, Tam T [ORNL; List III, Frederick Alyious [ORNL; Gouge, Michael J [ORNL; Chen, Y [SuperPower Incorporated, Schenectady, New York; X, Xiong, [SuperPower Incorporated, Schenectady, New York; Selvamanickam, V. [SuperPower Incorporated, Schenectady, New York
While the performance of YBa{sub 2}Cu{sub 3}O{sub 7-x} (YBCO)-based coated conductors under dc currents has improved significantly in recent years, filamentization is being investigated as a technique to reduce ac loss so that the 2nd generation (2G) high temperature superconducting (HTS) wires can also be utilized in various ac power applications such as cables, transformers and fault current limiters. Experimental studies have shown that simply filamentizing the superconducting layer is not effective enough to reduce ac loss because of incomplete flux penetration in between the filaments as the length of the tape increases. To introduce flux penetration in between the filaments more uniformly and further reduce the ac loss, virtual transverse cross-cuts were made in superconducting filaments of the coated conductors fabricated using the metal organic chemical vapor deposition (MOCVD) method. The virtual transverse cross-cuts were formed by making cross-cuts (17 - 120 {micro}m wide) on the IBAD (ion beam assisted deposition)-MgO templates using laser scribing followed by depositing the superconducting layer ({approx} 0.6 {micro}m thick). AC losses were measured and compared for filamentized conductors with and without the cross-cuts under applied peak ac fields up to 100 mT. The results were analyzed to evaluate the efficacy of filament decoupling and the feasibility of using this method to achieve ac loss reduction.
Fabrication, qualification and test of high Jc ROEBEL YBCO coated conductor cable for HEP magnets
Lombardo, V.; Barzi, E.; Turrioni, D.; Zlobin, A.V.; /Fermilab; Long, N.J.; Badcock, R.A.
The ROEBEL cable concept allows for a high critical current cable assembled using commercially available YBa{sub 2}Cu{sub 3}O{sub 7-{Delta}} coated conductors. this approach to cable design leads to several technological improvements if applied to the manufacture process of next generation low inductance, high current density HTS coils. A reduction in inductance proves to be extremely important when it comes to protection of coils capable of generating fields in the range of 40-50T, such as the ones needed in the last stage of the cooling channel of a muon collider. In this work several aspects are presented including the qualification and minimum requirements for YBa{sub 2}Cu{sub 3}O{sub 7-{Delta}}coated conductor in terms of 2D current density uniformity and the manufacturing process of ROEBEL cables. Test results achieved using a superconducting transformer for critical current measurements in liquid helium are shown, discussed and compared to the performance of a single YBa{sub 2}Cu{sub 3}O{sub 7-{Delta}} coated conductor tape.
The Levitated Dipole Experiment (LDX) is a novel approach for studying magnetic confinement of a fusion plasma. In this approach, a superconducting ring coil is magnetically levitated for up to 8 hours a day in the center of a 5 meter diameter vacuum vessel. The levitated coil, with on-board helium supply, is called the gloating Coil (F-Coil). Although the maximum field at the coil is only 5.3 tesla, a react-and-wind Nb{sub 3}Sn conductor was selected because the relatively high critical temperature will enable the coil to remain levitated while it warms from 5 K to 10 K. Since pre-reacted Nb{sub 3}Sn tape is no longer commercially available, a composite conductor was designed that contains an 18 strand Nb{sub 3}Sn Rutherford cable. The cable was reacted and then soldered into a structural copper channel that completes the conductor and also provides quench protection. The strain state of the cable was continuously controlled during fabrication steps such as: soldering into the copper channel, spooling, and coil winding, to prevent degradation of the critical current. Measurements of strand and cable critical currents are reported, as well as estimates of the effect of fabrication, winding and operating strains on critical current.
FEMCAM Analysis of SULTAN Test Results for ITER Nb3SN Cable-conduit Conductors
Yuhu Zhai, Pierluigi Bruzzone, Ciro Calzolaio
Performance degradation due to filament fracture of Nb3 Sn cable-in-conduit conductors (CICCs) is a critical issue in large-scale magnet designs such as ITER which is currently being constructed in the South of France. The critical current observed in most SULTAN TF CICC samples is significantly lower than expected and the voltage-current characteristic is seen to have a much broader transition from a single strand to the CICC. Moreover, most conductors exhibit the irreversible degradation due to filament fracture and strain relaxation under electromagnetic cyclic loading. With recent success in monitoring thermal strain distribution and its evolution under the electromagnetic cyclic loading from in situ measurement of critical temperature, we apply FEMCAM which includes strand filament breakage and local current sharing effects to SULTAN tested CICCs to study Nb3 Sn strain sensitivity and irreversible performance degradation. FEMCAM combines the thermal bending effect during cool down and the EM bending effect due to locally accumulating Lorentz force during magnet operation. It also includes strand filament fracture and related local current sharing for the calculation of cable n value. In this paper, we model continuous performance degradation under EM cyclic loading based on strain relaxation and the transition broadening upon cyclic loading to the extreme cases seen in SULTAN test data to better quantify conductor performance degradation.
Measurement of Resistance and Strength of Conductor Splices in the MICE Coupling Magnets
Xu, Feng Yu; Pan, Heng; Wu, Hong; Lui, X. K.; Li, E.; Dietderich, Dan; Higley, Hugh; Tam, D. G.; Trillaud, Fredric; Wang, Li; Green, M.A.
The superconducting magnets for the Muon Ionization Cooling Experiment [1] (MICE) use a copper based Nb-Ti conductor with un-insulated dimensions of 0.95 by 1.60 mm. There may be as many as twelve splices in one MICE superconducting coupling coil. These splices are to be wound in the coil. The conductor splices produce Joule heating, which may cause the magnet to quench. A technique of making conductor splices was developed by ICST. Two types of 1-meter long of soldered lap-joints have been tested. Side-by-side splices and up-down one splices were studied theoretically and experimentally using two types of soft solder made of eutectic tin-lead solder and tin-silver solder. The resistances of the splices made by ICST were tested at LBNL at liquid helium temperatures over a range of magnetic fields up to 5 T. The breaking strength of 250 mm long splices was also measured at room temperature and liquid nitrogen temperature.
advanced transparency framework: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
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 Tesla: A Transparent, Extensible Session-Layer Framework for End-to-end Network Services...
Jones phase microscopy of transparent and anisotropic samples
Gillette, Martha U.
with a transparent sample. JPM uses a modified version of the Hilbert phase microscope (HPM) [15,16]. HPM is similar,20], in the sense that it uses spatial modulation to encode the phase information of the object. How- ever, in HPM
Radiation-transparent windows, method for imaging fluid transfers
Shu, Deming (Darien, IL); Wang, Jin (Burr Ridge, IL)
A thin, x-ray-transparent window system for environmental chambers involving pneumatic pressures above 40 bar is presented. The window allows for x-ray access to such phenomena as fuel sprays injected into a pressurized chamber that mimics realistic internal combustion engine cylinder operating conditions.
PodBase: Transparent storage management for personal devices
Druschel, Peter
PodBase: Transparent storage management for personal devices Ansley Post Petr Kuznetsov PeterBase, a system that automatically manages the data and storage across a household's personal devices and frees Druschel Max Planck Institute for Software Systems Rice University 1. INTRODUCTION Personal electronic
Device-Transparent Personal Storage Jacob Alo Strauss
Gummadi, Ramakrishna
Device-Transparent Personal Storage by Jacob Alo Strauss S.B., Massachusetts Institute personal devices, each of which typically presents the user with a storage management interface isolated and drift out of sync. This thesis presents Eyo, a novel personal storage system that provides device trans
Transparent and Conductive Carbon Nanotube Multilayer Thin Films Suitable as an Indium Tin Oxide Replacement
Park, Yong Tae
Transparent electrodes made from metal oxides suffer from poor flexibility and durability. Highly transparent and electrically conductive thin films based on carbon nanotubes (CNTs) were assembled as a potential indium tin oxide (ITO) replacement...
Creating transparency in the Chinese real estate development industry : a case study
Han, Feng, S.M. Massachusetts Institute of Technology
Transparency issue remains one of the top issues that have discouraged foreign investors to invest China's real estate market. This thesis establishes a framework for Chinese developers to create transparency for their ...
Text-Alternative Version of TAP Webinar: Measuring the Impact of Benchmarking & Transparency
Broader source: Energy.gov [DOE]
Transcript of the June TAP webinar, Measuring the Impact of Benchmarking & Transparency - Methodologies and the NYC Example.
Tesla: A Transparent, Extensible Session-Layer Framework for End-to-end Network Services
Gummadi, Ramakrishna
Tesla: A Transparent, Extensible Session-Layer Framework for End-to-end Network Services by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Arthur C. Smith Chairman, Department Committee on Graduate Students #12;2 #12;Tesla: A Transparent of these services, we describe Tesla, a transparent and extensible framework that allows session-layer services
TESLA: A Transparent, Extensible Session-Layer Architecture for End-to-end Network Services
TESLA: A Transparent, Extensible Session-Layer Architecture for End-to-end Network Services Jon describes TESLA, a transparent and extensible framework allowing session- layer services to be developed using a high-level flow- based abstraction. TESLA services can be deployed transparently using dynamic
Tesla: A Transparent, Extensible Session-Layer Framework for End-to-end Network Services
Tesla: A Transparent, Extensible Session-Layer Framework for End-to-end Network Services by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Arthur C. Smith Chairman, Department Committee on Graduate Students #12; 2 #12; Tesla: A Transparent of these services, we describe Tesla, a transparent and extensible framework that allows session-layer services
TESLA: A Transparent, Extensible Session-Layer Architecture for End-to-end Network Services
Gummadi, Ramakrishna
TESLA: A Transparent, Extensible Session-Layer Architecture for End-to-end Network Services Jon describes TESLA, a transparent and extensible framework allowing session- layer services to be developed using a high-level ôÊow- based abstraction. TESLA services can be deployed transparently using dynamic
Transparent Incremental State Saving in Time Warp Parallel Discrete Event Robert Rnngren, Michael Liljenstam Johan Montagnat
Boyer, Edmond
Transparent Incremental State Saving in Time Warp Parallel Discrete Event Simulation Robert is the state saving mechanism. It should not only allow efficient state saving, but also support efficient is transparent to the user. In this paper we present a method to implement a transparent incremental state saving
All-optical Hall effect by the dynamic toroidal moment in a cavity-based metamaterial
Dong, Zheng-Gao; Yin, Xiaobo; Li, Jiaqi; Lu, Changgui; Zhang, Xiang
Dynamic dipolar toroidal response is demonstrated by an optical plasmonic metamaterial composed of double disks. This response with a hotspot of localized E-field concentration is a well-behaved toroidal cavity mode that exhibits a large Purcell factor due to its deep-subwavelength mode volume. All-optical Hall effect (photovoltaic) due to this optical toroidal moment is demonstrated numerically, in mimicking the magnetoelectric effect in multiferroic systems. The result shows a promising avenue to explore various optical phenomena associated with this intriguing dynamic toroidal moment.
Phase-constant-nonreciprocal composite right/left-handed metamaterials based on coplanar waveguides
Porokhnyuk, Andrey, E-mail: email@example.com; Ueda, Tetsuya; Kado, Yuichi [Department of Electronics, Kyoto Institute of Technology, Kyoto 606-8585 (Japan); Itoh, Tatsuo [Department of Electrical Engineering, University of California at Los Angeles, Los Angeles, California 90095 (United States)
The purely phase-constant-nonreciprocal composite right-left handed metamaterial structure is proposed based on coplanar waveguides loaded with a ferrite layer. The structure exhibits considerably large nonreciprocity in phase constant which depends on the effective magnetization and whose magnitude can remain in leaky wave region of wavenumbers or can overcome a boundary to slow wave region. The nonreciprocity in amplitude of transmission coefficients, on the other hand, is effectively reduced by using a cavity-backed design to prevent undesired nonreciprocal radiation loss.
Near-field thermal radiation between hyperbolic metamaterials: Graphite and carbon nanotubes
Liu, X. L.; Zhang, R. Z.; Zhang, Z. M., E-mail: email@example.com [G. W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)
The near-field radiative heat transfer for two hyperbolic metamaterials, namely, graphite and vertically aligned carbon nanotubes (CNTs), is investigated. Graphite is a naturally existing uniaxial medium, while CNT arrays can be modeled as an effective anisotropic medium. Different hyperbolic modes can be separately supported by these materials in certain infrared regions, resulting in a strong enhancement in near-field heat transfer. It is predicted that the heat flux between two CNT arrays can exceed that between SiC plates at any vacuum gap distance and is about 10 times higher with a 10?nm gap.
Transparent runtime parallelization of the R scripting language
Yoginath, Srikanth B [ORNL
Scripting languages such as R and Matlab are widely used in scientific data processing. As the data volume and the complexity of analysis tasks both grow, sequential data processing using these tools often becomes the bottleneck in scientific workflows. We describe pR, a runtime framework for automatic and transparent parallelization of the popular R language used in statistical computing. Recognizing scripting languages interpreted nature and data analysis codes use pattern, we propose several novel techniques: (1) applying parallelizing compiler technology to runtime, whole-program dependence analysis of scripting languages, (2) incremental code analysis assisted with evaluation results, and (3) runtime parallelization of file accesses. Our framework does not require any modification to either the source code or the underlying R implementation. Experimental results demonstrate that pR can exploit both task and data parallelism transparently and overall has better performance as well as scalability compared to an existing parallel R package that requires code modification.
Ultraslow Propagation of Squeezed Vacuum Pulses with Electromagnetically Induced Transparency
Daisuke Akamatsu; Yoshihiko Yokoi; Manabu Arikawa; Satoshi Nagatsuka; Takahito Tanimura; Akira Furusawa; Mikio Kozuma
We have succeeded in observing ultraslow propagation of squeezed vacuum pulses with electromagnetically induced transparency. Squeezed vacuum pulses (probe lights) were incident on a laser cooled 87Rb gas together with an intense coherent light (control light). A homodyne method sensitive to the vacuum state was employed for detecting the probe pulse passing through the gas. A delay of 3.1us was observed for the probe pulse having a temporal width of 10 us.
Nanoantennas for enhanced light trapping in transparent organic solar cells
Voroshilov, Pavel M; Belov, Pavel A
We propose a light-trapping structure offering a significant enhancement of photovoltaic absorption in transparent organic solar cells operating at infrared while the visible light transmission keeps sufficiently high. The main mechanism of light trapping is related with the excitation of collective oscillations of the metal nanoantenna arrays, characterized by advantageous field distribution in the volume of the solar cell. It allows more than triple increase of infrared photovoltaic absorption.
Total neutron-nucleus cross sections and color transparency
Jennings, B.K. (TRIUMF, Vancouver, V6T2A3 (Canada)); Miller, G.A. (Nuclear Theory Group, Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States))
The neutron-nucleus cross section at Fermi lab energies is computed using Glauber-Gribov multiple scattering theory. The effects of higher moments in the cross section fluctuations are included and their physical origin discussed. The validity of the frozen approximation is critically examined. These studies of the nucleon-nucleus total cross sections provide a test of the [ital pp][r arrow][ital Xp] diffractive amplitudes used in calculations of color transparency effects.
Mixed Ionic and Electonic Conductors for Hydrogen Generation and Separation: A New Approach
Srikanth Gopalan
Composite mixed conductors comprising one electronic conducting phase, and one ionic conducting phase (MIECs) have been developed in this work. Such MIECs have applications in generating and separating hydrogen from hydrocarbon fuels at high process rates and high purities. The ionic conducting phase comprises of rare-earth doped ceria and the electronic conducting phase of rare-earth doped strontium titanate. These compositions are ideally suited for the hydrogen separation application. In the process studied in this project, steam at high temperatures is fed to one side of the MIEC membrane and hydrocarbon fuel or reformed hydrocarbon fuel to the other side of the membrane. Oxygen is transported from the steam side to the fuel side down the electrochemical potential gradient thereby enriching the steam side flow in hydrogen. The remnant water vapor can then be condensed to obtain high purity hydrogen. In this work we have shown that two-phase MIECs comprising rare-earth ceria as the ionic conductor and doped-strontium titanate as the electronic conductor are stable in the operating environment of the MIEC. Further, no adverse reaction products are formed when these phases are in contact at elevated temperatures. The composite MIECs have been characterized using a transient electrical conductivity relaxation technique to measure the oxygen chemical diffusivity and the surface exchange coefficient. Oxygen permeation and hydrogen generation rates have been measured under a range of process conditions and the results have been fit to a model which incorporates the oxygen chemical diffusivity and the surface exchange coefficient from the transient measurements.
Multiple-band reflective polarization converter using U-shaped metamaterial
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: email@example.com [College of Physical Science and Technology, Central China Normal University, Wuhan 430079 (China)
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.
Negative refractive index and higher-order harmonics in layered metallodielectric optical metamaterials
Maas, Ruben; Parsons, James; Polman, Albert
We study the propagation of light in a three-dimensional double-periodic Ag/TiO2 multilayer metamaterial composed of coupled plasmonic waveguides operating in the visible and UV spectral range. For these frequencies, light propagation in the plane of the waveguides is described by a negative phase velocity, while for the orthogonal direction light propagation is described by a Bloch wave composed of a large number of harmonics. As a result, the material cannot generally be described by a single phase index: decomposing the Bloch wave into different harmonics we show that for the wavelength range of interest the positive index m=1 harmonic dominates the propagation of light in the orthogonal direction. These results are corroborated by numerical simulations and optical refraction experiments on a double-periodic Ag/TiO2 multilayer metamaterial prism in the 380-600 nm spectral range, which show that positive refraction associated with right-handed harmonics dominates. Studying the isofrequency contours we find ...
Hyperbolic-metamaterial antennas for broadband enhancement of dipole emission to free space
Valagiannopoulos, C. A. [Department of Radio Science and Engineering, School of Electrical Engineering, Aalto University, P.O. Box 13000, FI-00076 Aalto (Finland); Department of Electrical and Computer Engineering, University of Texas at Austin, 1616 Guadalupe St., Texas 78712 (United States); Mirmoosa, M. S.; Nefedov, I. S.; Tretyakov, S. A.; Simovski, C. R. [Department of Radio Science and Engineering, School of Electrical Engineering, Aalto University, P.O. Box 13000, FI-00076 Aalto (Finland)
Dipole emitters used in nano optics and nanophotonics (e.g., fluorescent molecules or quantum dots) are weak radiators and thus detecting the radiation of a single emitter gets possible only if it is significantly enhanced. For this enhancement, one often utilizes resonant nanoantennas (Purcell's effect); this method, however, requires the exact knowledge of source location and radiation frequency which constitute a significant drawback. One known possibility for broadband location-insensitive radiation enhancement is to use a layer of the so-called hyperbolic metamaterial. However, the enhanced radiated energy is mainly directed into the volume of the lossy medium, where it is lost to heating. In this work, we suggest specific shapes of macroscopic hyperbolic metamaterial samples to open radiation windows for enhanced radiation to free space. We show that hyperbolic media slabs with properly shaped macroscopic grooves convert the evanescent waves produced by a dipole into waves traveling in free space, which results in the enhancement of useful radiation by one to two orders of magnitude. That level of enhancement of radiation into free-space which is also wideband and of non-resonant nature has not been reported up to now. These results may open possibilities for realization of broadband and directive antennas, where the primary radiators are randomly positioned fluorescent molecules or quantum dots.
Second harmonic generation from metamaterials strongly coupled to intersubband transitions in quantum wells
Campione, Salvatore, E-mail: email@example.com [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Center for Integrated Nanotechnologies (CINT), Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Department of Electrical Engineering and Computer Science, University of California Irvine, Irvine, California 92697 (United States); Benz, Alexander; Brener, Igal, E-mail: firstname.lastname@example.com [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Center for Integrated Nanotechnologies (CINT), Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Sinclair, Michael B. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Capolino, Filippo [Department of Electrical Engineering and Computer Science, University of California Irvine, Irvine, California 92697 (United States)
We theoretically analyze the second harmonic generation capacity of two-dimensional periodic metamaterials comprising sub-wavelength resonators strongly coupled to intersubband transitions in quantum wells (QWs) at mid-infrared frequencies. The metamaterial is designed to support a fundamental resonance at ?30?THz and an orthogonally polarized resonance at the second harmonic frequency (?60?THz), while the asymmetric quantum well structure is designed to provide a large second order susceptibility. Upon continuous wave illumination at the fundamental frequency we observe second harmonic signals in both the forward and backward directions, with the forward efficiency being larger. We calculate the overall second harmonic conversion efficiency of the forward wave to be ?1.3?æ?10{sup ?2} W/W{sup 2}a remarkably large value, given the deep sub-wavelength dimensions of the QW structure (about 1/15th of the free space wavelength of 10??m). The results shown in this Letter provide a strategy for designing easily fabricated sources across the entire infrared spectrum through proper choice of QW and resonator designs.
Measurement approaches to support future warhead arms control transparency
Olinger, C.T.; Frankle, C.M.; Johnson, M.W.; Poths, J.
Transparency on warhead stockpiles, warhead dismantlement, and fissile material stockpiles in nuclear weapons states will become increasingly important in the move beyond START II toward lower quantities of warheads. Congressional support for further warhead reductions will likely depend on the degree of irreversibility, or in other words, the rapidity with which warhead inventories could be reconstituted. Whether irreversibility considerations can be satisfied will depend on monitoring dismantlement as well as constraining the available stockpile of fissile materials for possible refabrication into warheads. Measurement techniques designed to address the above problems will need to consider NPT Article 1 obligations as well as Russian and US classification regulations, which prohibit or restrict the transfer of nuclear warhead design information to other states. Classification considerations currently limit the potential completeness of future inspections of weapons materials. Many conventional international safeguards approaches are not currently viable for arms control applications because they would reveal weapons design information. The authors discuss a variety of technical measures that may help to improve transparence of warhead and fissile material stockpiles and may enable limited warhead dismantlement transparency.
Insert Coil Test for HEP High Field Magnets Using YBCO Coated Conductor Tapes
Lombardo, V.; Barzi, E.; Turrioni, D.; Zlobin, A.V.; /Fermilab
The final beam cooling stages of a Muon Collider may require DC solenoid magnets with magnetic fields of 30-50 T. In this paper we present progress in insert coil development using commercially available YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} Coated Conductor. Technological aspects covered in the development, including coil geometry, insulation, manufacturing process and testing are summarized and discussed. Test results of double pancake coils operated in liquid nitrogen and liquid helium are presented and compared with the performance of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} tape short samples.
High current density electropolishing in the preparation of highly smooth substrate tapes for coated conductors
Kreiskott, Sascha (Los Alamos, NM); Matias, Vladimir (Santa Fe, NM); Arendt, Paul N. (Los Alamos, NM); Foltyn, Stephen R. (Los Alamos, NM); Bronisz, Lawrence E. (Los Alamos, NM)
A continuous process of forming a highly smooth surface on a metallic tape by passing a metallic tape having an initial roughness through an acid bath contained within a polishing section of an electropolishing unit over a pre-selected period of time, and, passing a mean surface current density of at least 0.18 amperes per square centimeter through the metallic tape during the period of time the metallic tape is in the acid bath whereby the roughness of the metallic tape is reduced. Such a highly smooth metallic tape can serve as a base substrate in subsequent formation of a superconductive coated conductor.
Arendt, Paul N.; Foltyn, Stephen R.; Stan, Liliana; Usov, Igor O.; Wang, Haiyan
Articles are provided including a base substrate having a layer of an IBAD oriented material thereon, and, a layer of barium-containing material selected from the group consisting of barium zirconate, barium hafnate, barium titanate, barium strontium titanate, barium dysprosium zirconate, barium neodymium zirconate and barium samarium zirconate, or a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates upon the layer of an IBAD oriented material. Such articles can further include thin films of high temperature superconductive oxides such as YBCO upon the layer of barium-containing material selected from the group consisting of barium zirconate, barium hafnate, barium titanate, barium strontium titanate, barium dysprosium zirconate, barium neodymium zirconate and barium samarium zirconate, or a cubic metal oxide material selected from the group consisting of rare earth zirconates and rare earth hafnates.
A MORE EFFICIENT ANODE MICROSTRUCTURE FOR SOFCs BASED ON PROTON CONDUCTORS
Rainwater, Ben H; Liu, Mingfei; Liu, Meilin
While the desired microstructure of the state-of-the-art Ni-YSZ anode for a solid oxide fuel cell (SOFC) based on YSZ is well known, the anode microstructure for a SOFC based on a proton conductor is yet to be optimized. In this study, we examined the effect of anode porosity on the performance of a SOFC based on BaZr{sub 0.1}Ce{sub 0.7}Y{sub 0.1}Yb{sub 0.1}O{sub 3??} (BZCYYb), a mixed ion (proton and oxygen anion) conductor with high ionic conductivity at intermediate temperatures. Three cells with Ni-BZCYYb cermet anodes of different porosities (37%, 42%, and 50%) and identical electrolytes and cathode components were fabricated and tested. Under typical fuel cell operating conditions, the cell with anode of the lowest porosity (37%), prepared without pore former, achieved the highest performance, demonstrating a peak power density of 1.2 W/cm{sup 2} at 750 ¯C. This is radically different from the results of Ni-YSZ anodes for YSZ based cells, where high anode porosity (?55%) is necessary to achieve high performance. The observed increase in performance (or electrocatalytic activity for anode reactions) is attributed primarily to the unique microstructure of the anode fabricated without the use of pore forming precursors.
Progress in superconducting performance of rolled multifilamentary Bi-2223 HTS composite conductors
Li, Q.; Riley, G.N. Jr.; Parrella, R.D. [American Superconductor Corp., Westborough, MA (United States)] [and others
Significant enhancements in critical current densities in rolled multifilamentary Bi-2223 HTS composite conductors have been achieved using the powder-in-tube technique. At 77 K and self field, oxide critical current densities (J{sub c})of 55 kA/cm{sup 2}, overall or engineering critical current densities of 15 kA/cm{sup 2}, and critical currents of 125 A have been achieved in different rolled multifilamentary composites. Progress in achieving such high electrical performance is believed to stem in part from an improvement of grain connectivity by reducing weak links. The J{sub c} dependence on magnetic field and the degree of c-axis texture of these high quality conductors have been investigated at various temperatures. Our results also demonstrate that the critical current retention in magnetic field can be independently controlled from the self field critical current density, suggesting that flux pinning improvements and weak link reductions can be separately engineered into Bi-2223 composites fabricated using manufacturable processes.
The Calculated and Measured Resistance for Splices between Conductors in a MICE Superconducting Coil
Green, Michael A.; Dietderich, Dan; Higley, Hugh; Pan, Heng; Tam, Darren; Trillaud, Federic; Wang, Li; Wu, Hong; Xu, Feng Yu
The resistance of superconducting joints within MICE coils is an important issue particularly for the coupling coils. The MICE tracker solenoids have only two superconducting joints in the three spectrometer set (end coil 1, the center coil and end coil 2). The AFC magnets may have only a single joint within the coil. The coupling coils may have as many as fifteen joints within the coil, due to relatively short piece lengths of the superconductor. LBNL and ICST looked at three types of coil joints. They are: (1) cold fusion butt joints, (2) side-by-side lap joints, and (3) up-down lap joints. A theoretical calculation of the joint resistance was done at LBNL and checked by ICST. After looking at the theoretical resistance of the three types of joints, it was decided that the cold welded butt joint was not an attractive alternative for joints within a MICE superconducting magnet coil. Side-by-side and up-down lap joints were fabricated at ICST using two types of soft solder between the conductors. These conductor joints were tested at LBNL at liquid helium temperatures over a range of magnetic fields. The joint resistance was compared with the theoretical calculations. Measurements of splice strength were also made at 300 K and 77 K.
Reconstruction of an unknown cavity with Robin boundary condition inside a heat conductor
Gen Nakamura; Haibing Wang
Active thermography is a non-destructive testing technique to detect the internal structure of a heat conductor, which is widely applied in industrial engineering. In this paper, we consider the problem of identifying an unknown cavity with Robin boundary condition inside a heat conductor from boundary measurements. To set up the inverse problem mathematically, we first state the corresponding forward problem and show its well-posedness in an anisotropic Sobolev space by the integral equation method. Then, taking the Neumann-to-Dirichlet map as mathematically idealized measured data for the active thermography, we present a linear sampling method for reconstructing the unknown Robin-type cavity and give its mathematical justification by using the layer potential argument. In addition, we analyze the indicator function used in this method and show its pointwise asymptotic behavior by investigating the reflected solution of the fundamental solution. From our asymptotic analysis, we can establish a pointwise reconstruction scheme for the boundary of the cavity, and can also know the distance to the unknown cavity as we probe it from its inside.
Multidimensional Nature of Molecular Organic Conductors Revealed by Angular Magnetoresistance Oscillations
Pashupati Dhakal, Harukazu Yoshino, Jeong-Il Oh, Koichi Kikuchi, Michael J. Naughton
Angle-dependent magnetoresistance experiments on organic conductors exhibit a wide range of angular oscillations associated with the dimensionality and symmetry of the crystal structure and electron energy dispersion. In particular, characteristics associated with 1, 2, and 3-dimensional electronic motion are separately revealed when a sample is rotated through different crystal planes in a magnetic field. Originally discovered in the TMTSF-based conductors, these effects are particularly pronounced in the related system (DMET){sub 2}I{sub 3}. Here, experimental and computational results for magnetoresistance oscillations in this material, over a wide range of magnetic field orientations, are presented in such a manner as to uniquely highlight this multidimensional behavior. The calculations employ the Boltzmann transport equation that incorporates the system's triclinic crystal structure, which allows for accurate estimates of the transfer integrals along the crystallographic axes, verifying the 1D, 2D and 3D nature of (DMET){sub 2}I{sub 3}, as well as crossovers between dimensions in the electronic behavior.
A calculation of the inductance of 3-phase buses comprised of square tubular conductors with 120-degree-angle spacing
Zuch, Howard Weller
LIBRARY A g M COLLEGE OF TEXAS A CALCULATION OF THE INDUCI'ANCE OF 3 ? PHASE BUSES COh6$ ISED OF SqUARE TUBULAR CONDUCTORS WITH 120-DEGREE-ANGLE S PAC ING A Thesis By Howard Wailer Zuch Submitted to ths Graduate School of the Agricultural... and Mechanical College of Texas in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE January 1959 Major Subject: Electrical Engineering A CAICULAT ION OF THE IMDUCTANCL' OF 3-PIIASI BUSES COMPR ISED OF SQUARE TUBULAR CONDUCTORS...
JOURNAL OF OPTIMIZATION THEORY AND APPLICATIONS: Vol.100, No. 2, pp. 253-263, FEBRUARY1999 On the Optimal Insulation of Conductors1
Cox, Steven J.
On the Optimal Insulation of Conductors1 S. J. COX,2 B. KAWOHL,3 AND P. X. UHLIG4 Communicated by K. A. Lurie Abstract. We coat a conductor with an insulator and equate the effec- tiveness of this procedure and conductivity of the insulator approach zero, the dissipation rate approaches the first eigenvalue of a Robin
Ballistic magnetoresistance in nickel single-atom conductors without magnetostriction Matthew R. Sullivan, Douglas A. Boehm, Daniel A. Ateya, Susan Z. Hua, and Harsh Deep Chopra*
Chopra, Harsh Deep
Ballistic magnetoresistance in nickel single-atom conductors without magnetostriction Matthew R single-atom conductors electrodeposited between microfabricated thin films. These measurements eliminate in electrodeposited Ni nanocontacts made between bulk Ni lead wires.2,3 Large magnetoresistance effect has also been
Rapid process for producing transparent, monolithic porous glass
Coronado, Paul R. (Livermore, CA)
A process for making transparent porous glass monoliths from gels. The glass is produced much faster and in much larger sizes than present technology for making porous glass. The process reduces the cost of making large porous glass monoliths because: 1) the process does not require solvent exchange nor additives to the gel to increase the drying rates, 2) only moderate temperatures and pressures are used so relatively inexpensive equipment is needed, an 3) net-shape glass monoliths are possible using this process. The process depends on the use of temperature to control the partial pressure of the gel solvent in a closed vessel, resulting in controlled shrinking during drying.
Radio-transparent multi-layer insulation for radiowave receivers
Choi, J. [Korea University, Anam-dong Seongbuk-gu, Seoul 136-713 (Korea, Republic of)] [Korea University, Anam-dong Seongbuk-gu, Seoul 136-713 (Korea, Republic of); Ishitsuka, H. [Department of Particle and Nuclear Physics, School of High Energy Accelerator Science, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama, Kanagawa 240-0193 (Japan)] [Department of Particle and Nuclear Physics, School of High Energy Accelerator Science, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Mima, S. [Terahertz Sensing and Imaging Team, Terahertz-wave Research Group, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan)] [Terahertz Sensing and Imaging Team, Terahertz-wave Research Group, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Oguri, S., E-mail: email@example.com [Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Oho, Tsukuba, Ibaraki 305-0801 (Japan); Takahashi, K. [Terahertz Sensing and Imaging Team, Terahertz-wave Research Group, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan) [Terahertz Sensing and Imaging Team, Terahertz-wave Research Group, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Department of Physics, Tohoku University, Sendai, Miyagi 980-8578 (Japan); Tajima, O. [Department of Particle and Nuclear Physics, School of High Energy Accelerator Science, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama, Kanagawa 240-0193 (Japan) [Department of Particle and Nuclear Physics, School of High Energy Accelerator Science, The Graduate University for Advanced Studies (SOKENDAI), Shonan Village, Hayama, Kanagawa 240-0193 (Japan); Institute of Particle and Nuclear Studies, High Energy Accelerator Research Organization (KEK), Oho, Tsukuba, Ibaraki 305-0801 (Japan)
In the field of radiowave detection, enlarging the receiver aperture to enhance the amount of light detected is essential for greater scientific achievements. One challenge in using radio transmittable apertures is keeping the detectors cool. This is because transparency to thermal radiation above the radio frequency range increases the thermal load. In shielding from thermal radiation, a general strategy is to install thermal filters in the light path between aperture and detectors. However, there is difficulty in fabricating metal mesh filters of large diameters. It is also difficult to maintain large diameter absorptive-type filters in cold because of their limited thermal conductance. A technology that maintains cold conditions while allowing larger apertures has been long-awaited. We propose radio-transparent multi-layer insulation (RT-MLI) composed from a set of stacked insulating layers. The insulator is transparent to radio frequencies, but not transparent to infrared radiation. The basic idea for cooling is similar to conventional multi-layer insulation. It leads to a reduction in thermal radiation while maintaining a uniform surface temperature. The advantage of this technique over other filter types is that no thermal links are required. As insulator material, we used foamed polystyrene; its low index of refraction makes an anti-reflection coating unnecessary. We measured the basic performance of RT-MLI to confirm that thermal loads are lowered with more layers. We also confirmed that our RT-MLI has high transmittance to radiowaves, but blocks infrared radiation. For example, RT-MLI with 12 layers has a transmittance greater than 95% (lower than 1%) below 200 GHz (above 4 THz). We demonstrated its effects in a system with absorptive-type filters, where aperture diameters were 200 mm. Low temperatures were successfully maintained for the filters. We conclude that this technology significantly enhances the cooling of radiowave receivers, and is particularly suitable for large-aperture systems. This technology is expected to be applicable to various fields, including radio astronomy, geo-environmental assessment, and radar systems.
Is the Universe transparent to TeV photons?
W. Kluzniak
If Lorentz invariance is broken at an energy scale Eq, as has recently been suggested in the context of attempts to quantize gravity, the kinematics of photon-photon collisions would be profoundly affected at lower energies. Specifically, electron-positron pair creation on soft photons may be forbidden at photon energies as low as 30 TeV times square root of (Eq/10**17 GeV) and the Universe would then be transparent to high energy photons. The proposition that Lorentz invariance is broken may be falsified by the techniques of TeV astronomy.
Few-cycle self-induced-transparency solitons
Lin, Yuan Yao; Chen, I-Hong; Lee, Ray-Kuang [Institute of Photonics Technologies, National Tsing Hua University Hsinchu, Taiwan (China)
We reveal the existence of an optical self-induced-transparency soliton family in a two-level absorbing system down to the few-cycle limit. Based on the few-cycle envelope approximation, we introduce a systematical method of reducing the Maxwell-Bloch equations beyond the slowly varying envelope approximation and characterize the parameter space to achieve slow and fast lights. Verified by direct numerical simulations with full vectorial Maxwell-Bloch equations, we also give the relationships for a number of optical cycles on area theory and pulse group velocity, which demonstrate possible coherent photon-matter interactions.
Electromagnetically induced transparency in mechanical effects of light
Agarwal, G. S.; Huang, Sumei [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)
We consider the dynamical behavior of a nanomechanical mirror in a high-quality cavity under the action of a coupling laser and a probe laser. We demonstrate the existence of the analog of electromagnetically induced transparency (EIT) in the output field at the probe frequency. Our calculations show explicitly the origin of EIT-like dips as well as the characteristic changes in dispersion from anomalous to normal in the range where EIT dips occur. Remarkably the pump-probe response for the optomechanical system shares all the features of the {Lambda} system as discovered by Harris and collaborators.
Electromagnetically induced transparency with quantized fields in optocavity mechanics
Huang Sumei; Agarwal, G. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)
We report electromagnetically induced transparency (EIT) using quantized fields in optomechanical systems. The weak probe field is a narrowband squeezed field. We present a homodyne detection of EIT in the output quantum field. We find that the EIT dip exists even though the photon number in the squeezed vacuum is at the single-photon level. The EIT with quantized fields can be seen even at temperatures on the order of 100 mK, thus paving the way for using optomechanical systems as memory elements.
Functional composites of plasmas and metamaterials: Flexible waveguides, and variable attenuators with controllable phase shift
Sakai, Osamu; Maeda, Jun; Shimomura, Takuya [Department of Electronic Science and Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan)] [Department of Electronic Science and Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); Urabe, Keiichiro [Department of Electronic Science and Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan) [Department of Electronic Science and Engineering, Kyoto University, Kyoto-daigaku Katsura, Nishikyo-ku, Kyoto 615-8510 (Japan); Department of Advanced Materials Science, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8561 (Japan)
Numerical predictions and experimental results in this study verify that plasmas with negative permittivity work as functional media for electromagnetic waves and that their composites with metallic metamaterials show further extraordinary properties. Chain structures of individual plasmas with negative permittivity, forming a straight line and a L-shaped bent line, serve flexible waveguides via coupling structures of localized surface waves standing around each plasma. Further progresses as wave controllers are achievable in an array of the composites of plasmas and micro metallic resonators; functions of phase shifters and attenuators are individually controlled, with rotation of working points on the complex refractive index plane by varying gas conditions and permeability modulation. Such proposed sets of flexible combination will lead to advanced scientific products with novel functions.
Negative refraction imaging of acoustic metamaterial lens in the supersonic range
Han, Jianning [School of Information and Communication Engineering, North University of China, Taiyuan 030051 (China); Wen, Tingdun [Key Laboratory of Instrumental Science and Dynamic Testing, Ministry of Education, North University of China, Taiyuan 030051 (China); Key Laboratory of Electronic Testing Technology, North University of China, Taiyuan 030051 (China); Yang, Peng; Zhang, Lu [Key Laboratory of Electronic Testing Technology, North University of China, Taiyuan 030051 (China)
Acoustic metamaterials with negative refraction index is the most promising method to overcome the diffraction limit of acoustic imaging to achieve ultrahigh resolution. In this paper, we use localized resonant phononic crystal as the unit cell to construct the acoustic negative refraction lens. Based on the vibration model of the phononic crystal, negative quality parameters of the lens are obtained while excited near the system resonance frequency. Simulation results show that negative refraction of the acoustic lens can be achieved when a sound wave transmiting through the phononic crystal plate. The patterns of the imaging field agree well with that of the incident wave, while the dispersion is very weak. The unit cell size in the simulation is 0.0005 m and the wavelength of the sound source is 0.02 m, from which we show that acoustic signal can be manipulated through structures with dimensions much smaller than the wavelength of incident wave.
Achieving selective interrogation and sub-wavelength resolution in thin plates with embedded metamaterial acoustic lenses
Semperlotti, F., E-mail: firstname.lastname@example.com; Zhu, H. [Department of Aerospace and Mechanical Engineering, University of Notre Dame, Notre Dame, Indiana 46556 (United States)
In this study, we present an approach to ultrasonic beam-forming and high resolution identification of acoustic sources having critical implications for applications such as structural health monitoring. The proposed concept is based on the design of dynamically tailored structural elements via embedded acoustic metamaterial lenses. This approach provides a completely new alternative to conventional phased-array technology enabling the formation of steerable and collimated (or focused) ultrasonic beams by exploiting a single transducer. Numerical results show that the ultrasonic beam can be steered by simply tuning the frequency of the excitation. Also, the embedded lens can be designed to achieve sub-wavelength resolution to clustered acoustic sources, which is a typical scenario encountered in incipient structural damage.
Elastodynamic behavior of the three dimensional layer-by-layer metamaterial structure
Aravantinos-Zafiris, N.; Sigalas, M. M. [Department of Materials Science, University of Patras, 26504 Patras (Greece); Economou, E. N. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and TechnologyHellas (FORTH), P.O. Box 1385, Heraklion GR-71110, Greece and Department of Physics, University of Crete, Heraklion GR-71003 (Greece)
In this work, we numerically investigate for the first time the elastodynamic behavior of a three dimensional layer-by-layer rod structure, which is easy to fabricate and has already proved to be very efficient as a photonic crystal. The Finite Difference Time Domain method was used for the numerical calculations. For the rods, several materials were examined and the effects of all the geometric parameters of the structure were also numerically investigated. Additionally, two modifications of the structure were included in our calculations. The results obtained here (for certain geometric parameters), exhibiting a high ratio of longitudinal over transverse sound velocity and therefore a close approach to ideal pentamode behavior over a frequency range, clearly show that the layer-by-layer rod structure, besides being an efficient photonic crystal, is a very serious contender as an elastodynamic metamaterial.
Meta-atom cluster acoustic metamaterial with broadband negative effective mass density
Chen, Huaijun; Zhai, Shilong; Ding, Changlin; Liu, Song; Luo, Chunrong; Zhao, Xiaopeng, E-mail: email@example.com [Smart Materials Laboratory, Department of Applied Physics, Northwestern Polytechnical University, Xi'an 710129 (China)
We design a resonant meta-atom cluster, via which a two-dimensional (2D) acoustic metamaterial (AM) with broadband negative effective mass density from 1560 Hz to 5580 Hz is fabricated. Experimental results confirm that there is only weak interaction among the meta-atoms in the cluster. And then the meta-atoms in the cluster independently resonate, resulting in the cluster becoming equivalent to a broadband resonance unit. Extracted effective refractive indices from reflection and transmission measurements of the 2D AM appear to be negative from 1500 Hz to 5480 Hz. The broadband negative refraction has also been demonstrated by our further experiments. We expect that this meta-atom cluster AM will significantly contribute to the design of broadband negative effective mass density AM.
Fresnel versus Kummer surfaces: geometrical optics in dispersionless linear (meta)materials and vacuum
Favaro, Alberto
Geometrical optics describes, with good accuracy, the propagation of high-frequency plane waves through an electromagnetic medium. Under such approximation, the behaviour of the electromagnetic fields is characterised by just three quantities: the temporal frequency $\\omega$, the spatial wave (co)vector $k$, and the polarisation (co)vector $a$. Numerous key properties of a given optical medium are determined by the Fresnel surface, which is the visual counterpart of the equation relating $\\omega$ and $k$. For instance, the propagation of electromagnetic waves in a uniaxial crystal, such as calcite, is represented by two light-cones. Kummer, whilst analysing quadratic line complexes as models for light rays in an optical apparatus, discovered in the framework of projective geometry a quartic surface that is linked to the Fresnel one. Given an arbitrary dispersionless linear (meta)material or vacuum, we aim to establish whether the resulting Fresnel surface is equivalent to, or is more general than, a Kummer su...
Fresnel versus Kummer surfaces: geometrical optics in dispersionless linear (meta)materials and vacuum
Alberto Favaro; Friedrich W. Hehl
Geometrical optics describes, with good accuracy, the propagation of high-frequency plane waves through an electromagnetic medium. Under such approximation, the behaviour of the electromagnetic fields is characterised by just three quantities: the temporal frequency $\\omega$, the spatial wave (co)vector $k$, and the polarisation (co)vector $a$. Numerous key properties of a given optical medium are determined by the Fresnel surface, which is the visual counterpart of the equation relating $\\omega$ and $k$. For instance, the propagation of electromagnetic waves in a uniaxial crystal, such as calcite, is represented by two light-cones. Kummer, whilst analysing quadratic line complexes as models for light rays in an optical apparatus, discovered in the framework of projective geometry a quartic surface that is linked to the Fresnel one. Given an arbitrary dispersionless linear (meta)material or vacuum, we aim to establish whether the resulting Fresnel surface is equivalent to, or is more general than, a Kummer surface.
Beam Collimation Using an Anisotropic Metamaterial Slab without Any Nanometer-sized Aperture
Zhang, Shou; Cui, Yanxia; Zhang, Feng; He, Sailing; Hao, Yuying; Zhu, Furong
Plasmonic beam collimation effect has been thoroughly investigated based on the well-known nanometer-scale bull's eye structure formed by complex and high-cost fabrication processes. In this work, we report our effort for attaining beam collimation using an anisotropic metamaterial (AMM) slab that consists of a stack of alternating metal/dielectric layers and an integrated top metal grating. The results show that AMM slab allows creating the beam collimation effect similar to that of the bull's eye structure, an enabling technology for practical application due to its simple architecture and cost benefits. The excitation of surface plasmons at the AMM/air interface is derived. The structure of the AMM slab and its impact on beaming performance were analyzed using the effective medium theory and Finite Element Method.
A universal electromagnetic energy conversion adapter based on a metamaterial absorber
Xie, Yunsong; Wilson, Jeffrey D; Simons, Rainee N; Chen, Yunpeng; Xiao, John Q
On the heels of metamaterial absorbers (MAs) which produce near perfect electromagnetic (EM) absorption and emission, we propose a universal electromagnetic energy conversion adapter (UEECA) based on MA. By choosing the appropriate energy converting sensors, the UEECA is able to achieve near 100% signal transfer ratio between EM energy and various forms of energy such as thermal, DC electric, or higher harmonic EM energy. The inherited subwavelength dimension and the EM field intensity enhancement can further empower UEECA in many critical applications such as energy harvesting, solar cell, and nonlinear optics. The principle of UEECA is understood with a transmission line model, which further provides a design strategy that can incorporate a variety of energy conversion devices. The concept is experimentally validated at a microwave frequency with a signal transfer ratio of 96% by choosing an RF diode as the energy converting sensor.
Effective-medium model of wire metamaterials in the problems of radiative heat transfer
Mirmoosa, M. S., E-mail: firstname.lastname@example.com; Nefedov, I. S., E-mail: email@example.com; Simovski, C. R., E-mail: email@example.com [Department of Radio Science and Engineering, School of Electrical Engineering, Aalto University, P. O. Box 13000, 00076 Aalto (Finland); R■ting, F., E-mail: firstname.lastname@example.com [Departamento de FÚsica Teorica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC), Universidad Autonoma de Madrid, E-28049 (Spain)
In the present work, we check the applicability of the effective medium model (EMM) to the problems of radiative heat transfer (RHT) through so-called wire metamaterials (WMMs)composites comprising parallel arrays of metal nanowires. It is explained why this problem is so important for the development of prospective thermophotovoltaic (TPV) systems. Previous studies of the applicability of EMM for WMMs were targeted by the imaging applications of WMMs. The analogous study referring to the transfer of radiative heat is a separate problem that deserves extended investigations. We show that WMMs with practically realizable design parameters transmit the radiative heat as effectively homogeneous media. Existing EMM is an adequate tool for qualitative prediction of the magnitude of transferred radiative heat and of its effective frequency band.
Flexible and elastic metamaterial absorber for low frequency, based on small-size unit cell
Yoo, Y. J.; Zheng, H. Y.; Kim, Y. J.; Lee, Y. P., E-mail: email@example.com [Department of Physics and RINS, Hanyang University, Seoul 133-791 (Korea, Republic of); Rhee, J. Y. [Department of Physics, Sungkyunkwan University, Suwon (Korea, Republic of); Kang, J.-H. [Department of Nano and Electronic Physics, Kookmin University, Seoul (Korea, Republic of); Kim, K. W. [Department of Information Display, Sunmoon University, Asan (Korea, Republic of); Cheong, H. [Department of Physics, Sogang University, Seoul (Korea, Republic of); Kim, Y. H. [Infovion Inc., Seoul (Korea, Republic of)
Using a planar and flexible metamaterial (MM), we obtained the low-frequency perfect absorption even with very small unit-cell size in snake-shape structure. These shrunken, deep-sub-wavelength and thin MM absorbers were numerically and experimentally investigated by increasing the inductance. The periodicity/thickness (the figure of merit for perfect absorption) is achieved to be 10 and 2 for single-snake-bar and 5-snake-bar structures, respectively. The ratio between periodicity and resonance wavelength (in mm) is close to 1/12 and 1/30 at 2?GHz and 400?MHz, respectively. The absorbers are specially designed for absorption peaks around 2?GHz and 400?MHz, which can be used for depressing the electromagnetic noise from everyday electronic devices and mobile phones.
Investigating the effective range of vacuum ultraviolet-mediated breakdown in high-power microwave metamaterials
Liu, Chien-Hao, E-mail: firstname.lastname@example.com; Neher, Joel D., E-mail: email@example.com; Booske, John H., E-mail: firstname.lastname@example.com; Behdad, Nader, E-mail: email@example.com [Department of Electrical and Computer Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, Wisconsin 53706 (United States)
Metamaterials and periodic structures operating under high-power excitations are susceptible to breakdown. It was recently demonstrated that a localized breakdown created in a given region of a periodic structure can facilitate breakdown in other regions of the structure where the intensity of the incident electromagnetic fields may not be high enough to cause breakdown under normal circumstances. It was also demonstrated that this phenomenon is due to the generation of vacuum ultraviolet radiation at the location of the initial discharge, which propagates to the neighboring regions (e.g., other unit cells in a periodic structure) and facilitates the generation of a discharge at a lower incident power level. In this paper, we present the results of an experimental study conducted to determine the effective range of this physical phenomenon for periodic structures that operate in air and in pure nitrogen gas at atmospheric pressure levels. It is demonstrated that when breakdown is induced in a periodic structure using a high-power pulse with a frequency of 9.382 GHz, duration of 0.8 ?s, and peak power level of 25 kW, this phenomenon is highly likely to happen in radii of approximately 1617 mm from the location of the initial discharge under these test conditions. The results of this study are significant in designing metamaterials and periodic structures for high-power microwave applications as they suggest that a localized discharge created in such a periodic structure with a periodicity less than 1617 mm can spread over a large surface and result in a distributed discharge.
ON THE OPTIMAL INSULATION OF CONDUCTORS Steven J. Cox 1 , Bernhard Kawohl 2 , and Paul X. Uhlig 3
Kawohl, Bernd
ON THE OPTIMAL INSULATION OF CONDUCTORS Steven J. Cox 1 , Bernhard Kawohl 2 , and Paul X. Uhlig 3 1 with an insulator and equate the effectiveness of this procedure with the rate at which the body dissipates heat when immersed in an ice-- bath. In the limit, as the thickness and conductivity of the insulator
Transmission Channel Model and Capacity of Overhead Multi-conductor Medium-Voltage Power-lines for Broadband Communications
Kavehrad, Mohsen
Transmission Channel Model and Capacity of Overhead Multi-conductor Medium-Voltage Power-lines signal transmission, power-line has many non-ideal properties as a communications medium. Impedance-voltage power distribution networks for broadband power-line communications applications. Keywords - channel
photoreceptor, the conductor Fermi level, the barrier height, and the position of the semiconductor conduction band edges, (2) the
Fisher, Andrew
coupling of the chromophore to the conductor for high absorbance and high electron transfer efficiency and overall energy efficiency are limited by low dye coverage (8 ôÈ 1014 molecules cm22 ) and the resulting low from a 250-W tungsten lamp (Oriel, 6129), with intensity measured using a radiometer (IL1700
www.iaei.org July.August 2005 IAEI NEWS 83 GROUNDING PV AND SYSTEMS FINE STRANDED CONDUCTORS
Johnson, Eric E.
with single inverters sized below about 10 kW. Figure 1 shows the dc grounding for a PV system as spelled outwww.iaei.org July.August 2005 IAEI NEWS 83 GROUNDING PV AND SYSTEMS FINE STRANDED CONDUCTORS Grounding In the "Perspectives on PV" article in the September- October 2004 issue of the IAEI News
Superconductivityand absence of a Kohn anomaly in the quasi-one-dimensional organic conductor : (TMTSF)2AsF6 (+)
Paris-Sud XI, Universitûˋ de
L-607 Superconductivityand absence of a Kohn anomaly in the quasi-one-dimensional organic conductor Kohn û 2 kF û basse tempûˋrature et û pression atmosphûˋrique. Abstract. 2014 Superconductivity has been under 12 kbar. The establishment of the superconducting state is apparently not related to the existence
An Efficient Transparent Test Scheme for Embedded Word-Oriented Memories
Li, Jin-Fu; Wey, Chin-Long
Memory cores are usually the densest portion with the smallest feature size in system-on-chip (SOC) designs. The reliability of memory cores thus has heavy impact on the reliability of SOCs. Transparent test is one of useful technique for improving the reliability of memories during life time. This paper presents a systematic algorithm used for transforming a bit-oriented march test into a transparent word-oriented march test. The transformed transparent march test has shorter test complexity compared with that proposed in the previous works [Theory of transparent BIST for RAMs, A transparent online memory test for simultaneous detection of functional faults and soft errors in memories]. For example, if a memory with 32-bit words is tested with March C-, time complexity of the transparent word-oriented test transformed by the proposed scheme is only about 56% or 19% time complexity of the transparent word-oriented test converted by the scheme reported in [Theory of transparent BIST for RAMs] or [A transparent...
Ultrathin Ultra-broadband Electro-Absorption Modulator based on Few-layer Graphene based Anisotropic Metamaterial
Sayem, Ayed Al; Jahangir, Ifat; Rahman, Md Saifur
In this article, a few-layered graphene-dielectric multilayer (metamaterial) electro-optic modulator has been proposed in the mid and far infrared range that works on electro-absorption mechanism. Graphene, both mono layer and few layer, is an actively tunable optical material that allows control of inter-band and intra-band transition by tuning its chemical potential. Utilizing this unique feature of graphene, we propose a multilayer graphene dielectric stack where few layer graphene is preferred over mono layer graphene. Although the total thickness of the stack still remains in the nanometer range, this device can exhibit superior performances in terms of (i) high modulation depth, (ii) ultra-broadband performance, (iii) ultra-low insertion loss due to inherent metamaterial properties, (iv) nanoscale footprint, (v) polarization independence and (vi) capability of being integrated to a silicon waveguide. Interestingly, these superior performances, achievable by using few layer graphene with carefully design...
Experimental tests of dropwise cooling on infrared-transparent media
Tarozzi, Luca; Muscio, Alberto; Tartarini, Paolo [Department of Mechanical and Civil Engineering, University of Modena and Reggio Emilia, Via Vignolese, 905, 41100 Modena (Italy)
The present work is aimed at analyzing the cooling of hot solid surfaces induced by liquid droplets. In particular, the study is focused on the non-intrusive measurement of the transient contact temperature between impinging droplets and hot solid surfaces. An experimental apparatus was built and set up in order to approach the non-trivial problem of the measurement of a solid-liquid interface temperature after droplet impingement. The solid-liquid interface temperature was monitored from below through a transparent-to-infrared material. That material had been coated with a very thin layer of high-emissivity, opaque paint on its upper side, so that it could effectively respond to the infrared camera located below. The paper reports the main results that have been collected to date, with particular regard to the approaches used to coat the transparent solid. Some considerations are also expressed about the effectiveness of the proposed method and about the improvements that are currently being implemented to get new and more accurate interface temperature measurements. (author)
Novel solid state proton-conductors based on polymeric non-oxy acids. Final report
Appleby, A.J.; Srinivasan, S.; Parthasarathy, A.; Gonzalez, E.R. [Texas A and M Univ., College Station, TX (United States). Center for Electrochemical Systems and Hydrogen Research; DesMarteau, D.; Gillette, M.S.; Ghosh, J.K. [Clemson Univ., SC (United States). Dept. of Chemistry; Jalan, V.; Desai, M. [ElectroChem, Inc., Woburn, MA (United States)
Objectives of this project were to prepare and characterize novel solid state proton-conductors and to evaluate these compounds as fuel cell electrolytes. The thrust was on the synthesis of new proton-conducting ``model`` and ``polymeric`` compounds, based on acid functions of the type (R{sub f}SO{sub 2}){sub 2}NH and (R{sub f}SO{sub 2}){sub 2}CH{sub 2} in appropriate fluorinated carbon structures, their physics-chemical characterization (Infra-red, Nuclear Magnetic Resonance, Differential Scanning Calorimetry, and X-ray Diffraction), and is pro. evaluation as candidate fuel cell electrolytes for use at elevated temperatures. This project consisted of four tasks (i) Synthesis of Proton-Conducting Polymer Electrolytes; (ii) Physical and Chemical Characterization of Proton-Conducting Polymer Electrolytes; (iii) Electrochemical Characterization of Proton-Conducting Polymer Electrolytes; and (iv) Evaluation of Proton-Conducting Polymer Electrolytes for Fuel Cells.
Method of reducing multipole content in a conductor assembly during manufacture
Meinke, Rainer (Melbourne, FL)
A method for manufacture of a conductor assembly. The assembly is of the type which, when conducting current, generates a magnetic field or in which, in the presence of a changing magnetic field, a voltage is induced. In an example embodiment one or more first coil rows are formed. The assembly has multiple coil rows about an axis with outer coil rows formed about inner coil rows. A determination is made of deviations from specifications associated with the formed one or more first coil rows. One or more deviations correspond to a magnitude of a multipole field component which departs from a field specification. Based on the deviations, one or more wiring patterns are generated for one or more second coil rows to be formed about the one or more first coil rows. The one or more second coil rows are formed in the assembly. The magnitude of each multipole field component that departs from the field specification is offset.
Method of reducing multipole content in a conductor assembly during manufacture
Meinke, Rainer
A method for manufacture of a conductor assembly. The assembly is of the type which, when conducting current, generates a magnetic field or in which, in the presence of a changing magnetic field, a voltage is induced. In an example embodiment one or more first coil rows are formed. The assembly has multiple coil rows about an axis with outer coil rows formed about inner coil rows. A determination is made of deviations from specifications associated with the formed one or more first coil rows. One or more deviations correspond to a magnitude of a multipole field component which departs from a field specification. Based on the deviations, one or more wiring patterns are generated for one or more second coil rows to be formed about the one or more first coil rows. The one or more second coil rows are formed in the assembly. The magnitude of each multipole field component that departs from the field specification is offset.
Microstructural Development and Superconducting Parameters of the YBa2Cu3O7-delta Coated Conductor
Rutter, Noel Anthony
and Superconducting Parameters of the YBa2Cu3O7-? Coated Conductor Noel Rutter 226 49. N. Koshizuka, T. Takagi, J.G. Wen, K. Nakao, T. Usagawa, Y. Eltsev, and T. Machi, Physica C, 2000. 337(1-4): p. 1-6. 50. J.G. Wen, T. Takagi, and N. Koshizuka, Supercond. Sci... (2 Pt2): p. 1502-1505. 104. F. Yang, E. Narumi, S. Patel, and D.T. Shaw, Physica C, 1995. 244(3-4): p. 299-304. 105. E.Y. Zhou, S.M. Gong, Y.J. Mao, M.P. Yuan, H. Zhang, J. Yuan, G.Q. Yang, X.H. Liu, and S.C. Zou, Physica C, 1997. 282(Pt2): p. 617...
Doubling the critical current density of high temperature superconducting coated conductors through proton irradiation
Jia, Y.; LeRoux, M.; Miller, D. J.; Wen, J. G.; Kwok, W. K.; Welp, U. [Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439 (United States)] [Materials Science Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, Illinois 60439 (United States); Rupich, M. W.; Li, X.; Sathyamurthy, S.; Fleshler, S.; Malozemoff, A. P. [American Superconductor Corp., 64 Jackson Road, Devens, Massachusetts 01434 (United States)] [American Superconductor Corp., 64 Jackson Road, Devens, Massachusetts 01434 (United States); Kayani, A. [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States)] [Department of Physics, Western Michigan University, Kalamazoo, Michigan 49008-5252 (United States); Ayala-Valenzuela, O.; Civale, L. [Los Alamos National Laboratory, MS-K764, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, MS-K764, Los Alamos, New Mexico 87545 (United States)
The in-field critical current of commercial YBa{sub 2}Cu{sub 3}O{sub 7} coated conductors can be substantially enhanced by post-fabrication irradiation with 4 MeV protons. Irradiation to a fluence of 8 æ 10{sup 16} p/cm{sup 2} induces a near doubling of the critical current in fields of 6 T || c at a temperature of 27 K, a field and temperature range of interest for applications, such as rotating machinery. A mixed pinning landscape of preexisting precipitates and twin boundaries and small, finely dispersed irradiation induced defects may account for the improved vortex pinning in high magnetic fields. Our data indicate that there is significant head-room for further enhancements.
Oscillation of bundle conductors in overhead lines due to turbulent wind
Diana, G.; Cheli, F. (Politecnico di Milano, Milano (IT)); Manenti, A. (Universita degli Studi di Brescia, Brescia (IT)); Nicolini, P.; Tavano, F. (ENEL/CREI, Milano (IT))
Due to the wind, the bundle conductors in overhead lines can oscillate and the distance between the phases can be reduced. This kind of movement may be caused by: non expansive oscillations of the phases due to the wind turbulence and to the correlated variations of the bundles aerodynamic coefficients during the movement (buffeting); expansive oscillations, or galloping, of the phases due to the unstable aerodynamic shapes that bundles may assume in presence of ice. This paper presents an analytical methodology to examine the dynamic behaviour of bundles subjected to the above mentioned phenomena. The results obtained during experiments carried out on a span of an energized 420-kV line equipped with triple bundles and subjected to oscillations due to buffeting are exposed. Lastly, the experimental data are compared with the analytical results.
Thickness influence on surface morphology and ozone sensing properties of nanostructured ZnO transparent
, 71004 Heraklion, Crete, Greece Available online 19 January 2006 Abstract Transparent zinc oxide (Zn Keywords: Zinc oxide; PLD; AFM; Ozone 1. Introduction Zinc oxide (ZnO) is an n-type semiconductor devices [3], varistors, planar optical waveguides [4], transparent electrodes [5,6], ultraviolet
Optical storage with electromagnetically induced transparency in a dense cold atomic ensemble
Du, Shengwang
Optical storage with electromagnetically induced transparency in a dense cold atomic ensemble storage with electromagnetically induced transparency in a dense cold 85 Rb atomic ensemble. By varying the optical depth (OD) from 0 to 140, we observe that the optimal storage effi- ciency has a saturation value
Elastic properties of transparent nano-polycrystalline diamond measured by GHz-ultrasonic interferometry and resonant
Jacobsen, Steven D.
Elastic properties of transparent nano-polycrystalline diamond measured by GHz-ultrasonic interferometry Sphere resonance Nano-polycrystalline diamond NPD Elastic properties Superhard materials a b s t r a c t The sound velocities and elastic moduli of transparent nano-polycrystalline diamond (NPD) have
Graphene growth on glass 1 Synthesis of conducting transparent few-layer graphene directly
Paris-Sud XI, UniversitÕ de
Graphene growth on glass 1 Synthesis of conducting transparent few-layer graphene directly on glass major hurdles that research has to overcome to get graphene out of research laboratories. Here, using transparent graphene layers at temperatures as low as 450 ¯C. Our few-layer graphene grows at the interface
Quantitative analyses of damp-heat-induced degradation in transparent conducting oxides
Park, Byungwoo
Quantitative analyses of damp-heat-induced degradation in transparent conducting oxides Jae Ik Kim online 9 January 2014 Keywords: Transparent conducting oxides Al-doped ZnO Damp-heat test Photovoltaics oxides is essential for actual applications in photovoltaic devices or displays requiring long
Middleware Transparent Software Development & the MDA Devon Simmonds, Sudipto Ghosh, Robert France
Simmonds, Devon M.
Middleware Transparent Software Development & the MDA Devon Simmonds, Sudipto Ghosh, Robert France of middleware technologies and the pervasiveness of distributed systems. The Model Driven Architecture (MDA of the target middleware. To support the MDA vision we have developed an aspect-oriented middleware transparent
Transparent conductive grids via direct writing of silver nanoparticle inks Bok Yeop Ahn,a
Lewis, Jennifer
. Using this approach, microscale features ($1 mm) in one-dimensional (1D) to three-dimensional (3D transparency and electrical conductivity.6 Recent efforts have focused on printing and other solution routes and co-workers have produced transparent conductive arrays by inkjet printing of dilute silver
On the Benefits of Transparent Compression for Cost-Effective Cloud Data Storage
Paris-Sud XI, UniversitÕ de
On the Benefits of Transparent Compression for Cost-Effective Cloud Data Storage Bogdan Nicolae of IaaS middleware: excessive storage costs associated with both user data and VM images might make-off resulting from transparently applying data compression to conserve storage space and bandwidth at the cost
ISIS technical report series, Vol. 2002-06 User Transparency: A Fully Sequential
Seinstra, Frank J.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4 A Sustainable Software Architecture for User Transparent Parallel Image Processing 12 4 to provide such a tool, we have designed a software architecture that allows transparent (i.e., se- quential the software architecture, and gives an assessment of the architecture's effectiveness in providing signif
ISIS technical report series, Vol. 2002-06 User Transparency: A Fully Sequential
Seinstra, Frank J.
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 4 A Sustainable Software Architecture for User Transparent Parallel Image Processing 12 4 to provide such a tool, we have designed a software architecture that allows transparent (i.e., se- quential the software architecture, and gives an assessment of the architecture's e#11;ectiveness in providing signif
Infrared transparent frequency selective surface based on metallic meshes
Yu, Miao [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033 (China) [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033 (China); University of Chinese Academy of Sciences, Beijing, 100049 (China); Xu, Nianxi; Liu, Hai; Gao, Jinsong, E-mail: email@example.com [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033 (China)] [Key Laboratory of Optical System Advanced Manufacturing Technology, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, Changchun, 130033 (China)
This paper presents an infrared transparent frequency selective surface (ITFSS) based on metallic meshes. In this ITFSS structure, periodic cross-slot units are integrated on square metallic meshes empowered by coating and UV-lithography. A matching condition is proposed to avoid the distortion of units. Experimental results show that this ITFSS possesses a good transmittance of 80% in the infrared band of 35 ?m, and also a stable band-pass behavior at the resonance frequency of 36.4 GHz with transmittance of ?0.56 dB. Theoretical simulations about the ITFSS diffractive characteristics and frequency responses are also investigated. The novel ITFSS will attract renewed interest and be exploited for applications in various fields.
Optically transparent, scratch-resistant, diamond-like carbon coatings
He, Xiao-Ming; Lee, Deok-Hyung; Nastasi, Michael A.; Walter, Kevin C.; Tuszewski, Michel G.
A plasma-based method for the deposition of diamond-like carbon (DLC) coatings is described. The process uses a radio-frequency inductively coupled discharge to generate a plasma at relatively low gas pressures. The deposition process is environmentally friendly and scaleable to large areas, and components that have geometrically complicated surfaces can be processed. The method has been used to deposit adherent 100-400 nm thick DLC coatings on metals, glass, and polymers. These coatings are between three and four times harder than steel and are therefore scratch resistant, and transparent to visible light. Boron and silicon doping of the DLC coatings have produced coatings having improved optical properties and lower coating stress levels, but with slightly lower hardness.
Tunable electromagnetically induced transparency and absorption with dressed superconducting qubits
Ian, Hou [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Liu, Yu-xi [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Institute of Microelectronics, Tsinghua University, Beijing 100084 (China); Tsinghua National Laboratory for Information Science and Technology (TNList), Tsinghua University, Beijing 100084 (China); Nori, Franco [Advanced Science Institute, RIKEN, Wako-shi, Saitama 351-0198 (Japan); Physics Department, The University of Michigan, Ann Arbor, Michagan 48109 (United States)
Electromagnetically induced transparency and absorption (EIT and EIA) are usually demonstrated using three-level atomic systems. In contrast to the usual case, we theoretically study the EIT and EIA in an equivalent three-level system: a superconducting two-level system (qubit) dressed by a single-mode cavity field. In this equivalent system, we find that both the EIT and the EIA can be tuned by controlling the level-spacing of the superconducting qubit and hence controlling the dressed system. This tunability is due to the dressed relaxation and dephasing rates which vary parametrically with the level-spacing of the original qubit and thus affect the transition properties of the dressed qubit and the susceptibility. These dressed relaxation and dephasing rates characterize the reaction of the dressed qubit to an incident probe field. Using recent experimental data on superconducting qubits (charge, phase, and flux qubits) to demonstrate our approach, we show the possibility of experimentally realizing this proposal.
Tunable electromagnetically induced transparency with a coupled superconducting system
Xin Wang; Hong-rong Li; Wen-xiao Liu; Fu-li Li
Electromagnetically induced transparency (EIT) has usually been demonstrated by using three-level atomic systems. In this paper, we theoretically proposed an efficient method to realize EIT in microwave regime through a coupled system consisting of a flux qubit and a superconducting LC resonator with relatively high quality factor. In the present composed system, the working levels are the dressed states of a two-level flux qubit and the resonators with a probe pump field. There exits a second order coherent transfer between the dressed states. By comparing the results with those in the conventional atomic system we have revealed the physical origin of the EIT phenomenon in this composed system. Since the whole system is artificial and tunable, our scheme may have potential applications in various domains.
Semi-transparent solar energy thermal storage device
McClelland, John F. (Ames, IA)
A visually transmitting solar energy absorbing thermal storage module includes a thermal storage liquid containment chamber defined by an interior solar absorber panel, an exterior transparent panel having a heat mirror surface substantially covering the exterior surface thereof and associated top, bottom and side walls, Evaporation of the thermal storage liquid is controlled by a low vapor pressure liquid layer that floats on and seals the top surface of the liquid. Porous filter plugs are placed in filler holes of the module. An algicide and a chelating compound are added to the liquid to control biological and chemical activity while retaining visual clarity. A plurality of modules may be supported in stacked relation by a support frame to form a thermal storage wall structure.
Semi-transparent solar energy thermal storage device
McClelland, John F. (Ames, IA)
A visually transmitting solar energy absorbing thermal storage module includes a thermal storage liquid containment chamber defined by an interior solar absorber panel, an exterior transparent panel having a heat mirror surface substantially covering the exterior surface thereof and associated top, bottom and side walls. Evaporation of the thermal storage liquid is controlled by a low vapor pressure liquid layer that floats on and seals the top surface of the liquid. Porous filter plugs are placed in filler holes of the module. An algicide and a chelating compound are added to the liquid to control biological and chemical activity while retaining visual clarity. A plurality of modules may be supported in stacked relation by a support frame to form a thermal storage wall structure.
Electromagnetically Induced Transparency and Slow Light with Optomechanics
Safavi-Naeini, Amir H; Chan, Jasper; Eichenfield, Matt; Winger, Martin; Lin, Qiang; Hill, Jeffrey T; Chang, Darrick; Painter, Oskar
Controlling the interaction between localized optical and mechanical excitations has recently become possible following advances in micro- and nano-fabrication techniques. To date, most experimental studies of optomechanics have focused on measurement and control of the mechanical subsystem through its interaction with optics, and have led to the experimental demonstration of dynamical back-action cooling and optical rigidity of the mechanical system. Converseley, the optical response of these systems is also modified in the presence of mechanical interactions, leading to strong nonlinear optical effects such as Electromagnetically Induced Transparency (EIT) and parametric normal-mode splitting. In atomic systems, seminal experiments and proposals to slow and stop the propagation of light, and their applicability to modern optical networks, and future quantum networks, have thrust EIT to the forefront of experimental study during the last two decades. In a similar fashion, here we use the optomechanical nonli...
Electromagnetically Induced Transparency and Slow Light with Optomechanics
Amir H. Safavi-Naeini; Thiago P. Mayer Alegre; Jasper Chan; Matt Eichenfield; Martin Winger; Qiang Lin; Jeffrey T. Hill; Darrick Chang; Oskar Painter
Controlling the interaction between localized optical and mechanical excitations has recently become possible following advances in micro- and nano-fabrication techniques. To date, most experimental studies of optomechanics have focused on measurement and control of the mechanical subsystem through its interaction with optics, and have led to the experimental demonstration of dynamical back-action cooling and optical rigidity of the mechanical system. Conversely, the optical response of these systems is also modified in the presence of mechanical interactions, leading to strong nonlinear effects such as Electromagnetically Induced Transparency (EIT) and parametric normal-mode splitting. In atomic systems, seminal experiments and proposals to slow and stop the propagation of light, and their applicability to modern optical networks, and future quantum networks, have thrust EIT to the forefront of experimental study during the last two decades. In a similar fashion, here we use the optomechanical nonlinearity to control the velocity of light via engineered photon-phonon interactions. Our results demonstrate EIT and tunable optical delays in a nanoscale optomechanical crystal device, fabricated by simply etching holes into a thin film of silicon (Si). At low temperature (8.7 K), we show an optically-tunable delay of 50 ns with near-unity optical transparency, and superluminal light with a 1.4 microseconds signal advance. These results, while indicating significant progress towards an integrated quantum optomechanical memory, are also relevant to classical signal processing applications. Measurements at room temperature and in the analogous regime of Electromagnetically Induced Absorption (EIA) show the utility of these chip-scale optomechanical systems for optical buffering, amplification, and filtering of microwave-over-optical signals.
Do More Transparent Corporate Actions Following a Restatement Influence the SEC's Decision to Issue an Enforcement Action?
Files, Rebecca Lynn
This study examines whether corporate transparency about a restatement influences the Securities and Exchange Commission's (SEC) decision to issue an enforcement action. I consider corporate transparency to be higher when ...
Particle trap to sheath contact for a gas-insulated transmission line having a corrugated outer conductor
Fischer, William H. (Pittsburgh, PA); Cookson, Alan H. (Pittsburgh, PA); Yoon, Kue H. (Pittsburgh, PA)
A particle trap to outer elongated conductor or sheath contact for gas-insulated transmission lines. The particle trap to outer sheath contact of the invention is applicable to gas-insulated transmission lines having either corrugated or non-corrugated outer sheaths. The contact of the invention includes an electrical contact disposed on a lever arm which in turn is rotatably disposed on the particle trap and biased in a direction to maintain contact between the electrical contact and the outer sheath.
Proposal for the Award of a Contract for the Supplyof Superconducting 600 A Multi-Conductor Cable for the LHC
This document concerns the award of a contract for the supply of 25 450 metres of superconducting 600 A multi-conductor cable for the LHC. Following a market survey carried out among 55 firms in fourteen Member States, a call for tenders (IT-3140/LHC/LHC) was sent on 6 January 2003 to seven firms in six Member States. By the closing date, CERN had received five tenders from five firms in four Member States. The Finance Committee is invited to agree to the negotiation of a contract with HEW-KABEL (DE), the lowest bidder, for the supply of 25 450 metres of superconducting 600 A multi-conductor cable for a total amount of 800 796 euros (1 174 704 Swiss francs), not subject to revision, with options for additional purchases of up to a further 5% of superconducting multi-conductor cable for an amount not exceeding 40 040 euros (58 735 Swiss francs), not subject to revision, bringing the total amount to 840 836 euros (1 233 439 Swiss francs), not subject to revision. The rate of exchange used is that stipulated in ...
Nuclear qualified in-containment electrical connectors and method of connecting electrical conductors
Powell, J. G. (Clifton Park, NY)
A nuclear qualified in-containment electrical connection comprises an insulated, sheathed instrument lead having electrical conductors extending from one end thereof to provide two exposed lead wires, a watertight cable having electrical conducting wires therein and extending from one end of the cable to provide two lead wires therefrom, two butt splice connectors each connecting the ends of respective ones of the lead wires from the instrument lead and cable, a length of heat shrinkable plastic tubing positioned over each butt splice connector and an adjacent portion of a respective lead wire from the cable and heat shrunk into position, a length of heat shrinkable plastic tubing on the end portion of the instrument lead adjacent the lead wires therefrom and heat shrunk thereon and a length of outer heat shrinkable plastic tubing extending over the end portion of the instrument lead and the heat shrinkable tubing thereon and over the butt splice connectors and a portion of the cable adjacent the cable lead lines, the outer heat shrinkable tubing being heat shrunk into sealing position on the instrument lead and cable.
Tungsten Nanowire Based Hyperbolic Metamaterial Emitters for Near-field Thermophotovoltaic Applications
Chang, Jui-Yung; Wang, Liping
Recently, near-field radiative heat transfer enhancement across nanometer vacuum gaps has been intensively studied between two hyperbolic metamaterials (HMMs) due to unlimited wavevectors and high photonic density of state. In this work, we theoretically analyze the energy conversion performance of a thermophotovoltaic (TPV) cell made of In0.2Ga0.8Sb when paired with a HMM emitter composed of tungsten nanowire arrays embedded in Al2O3 host at nanometer vacuum gaps. Fluctuational electrodynamics integrated with effective medium theory and anisotropic thin-film optics is used to calculate the near-field radiative heat transfer. It is found that the spectral radiative energy is enhanced by the epsilon-near-zero and hyperbolic modes at different polarizations. As a result, the power output from a semi-infinite TPV cell is improved by 1.85 times with the nanowire HMM emitter over that with a plain tungsten emitter at a vacuum gap of 10 nm. Moreover, by using a thin TPV cell with 10 um thickness, the conversion eff...
Reconfigurable liquid metal based terahertz metamaterials via selective erasure and refilling to the unit cell level
Wang, Jinqi; Liu, Shuchang; Nahata, Ajay, E-mail: email@example.com [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)] [Department of Electrical and Computer Engineering, University of Utah, Salt Lake City, Utah 84112 (United States); Guruswamy, Sivaraman [Department of Metallurgical Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)] [Department of Metallurgical Engineering, University of Utah, Salt Lake City, Utah 84112 (United States)
We demonstrate a technique for selectively erasing and refilling unit cells of terahertz (THz) metamaterials. The structures are formed by injecting eutectic gallium indium (EGaIn), a liquid metal at room temperature, into microchannels within a polydimethylsiloxane (PDMS) mold fabricated using conventional soft lithography techniques. The thin oxide layer that forms on the surface of EGaIn can be locally dissolved via exposure to hydrochloric acid (HCl) introduced at the surface of the gas permeable PDMS mold. In the absence of the oxide skin, the liquid metal retracts to a position where a stable new oxide layer can be formed, effectively erasing the liquid metal structure in the presence of HCl. After erasing selected structures, EGaIn can be re-injected into microchannels to yield the initial structure. In the case of small unit cells, we show that mechanical pressure can be used to effectively erase individual elements. We use THz time-domain spectroscopy to characterize the distinct transmission properties for each of these different structures.
Array of dipoles near a hyperbolic metamaterial: Evanescent-to-propagating Floquet wave transformation
Guclu, Caner; Capolino, Filippo
We investigate the capabilities of hyperbolic metamaterials (HMs) to couple near-fields (i.e., evanescent waves) emitted by a two-dimensional periodic array of electric dipoles to propagating waves. In particular, large order Floquet harmonics with transverse magnetic (TM) polarization, that would be evanescent in free space and therefore confined near the array surface, are transformed into propagating spectrum inside the HM, and thus carry power away. Because of this property, independent of the finite or infinite extent of the HM, the power generated by an array of elementary electric dipoles is strongly enhanced when the array is located near a HM surface and is mostly directed into the HM. In particular, the power coupled to the HM exhibits narrow frequency features that can be employed in detection applications. The results shown in this paper provide a clear signature on wave dynamics in HMs. A link between the results pertaining to the case of an isolated dipole on top of HM and the planar array is fo...
Dipole induced transparency in drop-filter cavity-waveguide systems
Edo Waks; Jelena Vuckovic
We show that a waveguide that is normally opaque due to interaction with a drop-filter cavity can be made transparent when the drop filter is also coupled to a dipole. A transparency condition is derived between the cavity lifetime and vacuum Rabi frequency of the dipole. This condition is much weaker than strong coupling, and amounts to simply achieving large Purcell factors. Thus, we can observe transparency in the weak coupling regime. We describe how this effect can be useful for designing quantum repeaters for long distance quantum communication.
Electromagnetically-induced transparency and light storing of a pair of pulses
A. Raczynski; J. Zaremba; S. Zielinska-Kaniasty
Electromagnetically-induced transparency and light storing are studied in the case of a medium of atoms in a double Lambda configuration, both in terms of dark- and bright-state polatitons and atomic susceptibility. It is proven that the medium can be made transparent simultaneously for two pulses following their self-adjusting so that a condition for an adiabatic evolution has become fulfilled. Analytic formulas are given for the shapes and phases of the transmitted/stored pulses. The level of transparency can be regulated by adjusting the heights and phases of the control fields.
Tunable Electromagnetically Induced Transparency and Absorption with Dressed Superconducting Qubits
Hou Ian; Yu-xi Liu; Franco Nori
Electromagnetically induced transparency and absorption (EIT and EIA) are usually demonstrated by three-level atomic or atom-like systems. In contrast to the usual case, we theoretically study the EIT and EIA in an equivalent three-level system, which is constructed by dressing a superconducting two-level system (qubit) dressed by a single-mode cavity field. In this equivalent system, we find that both the EIT and the EIA can be tuned by controlling the level-spacing of the superconducting qubit and hence controlling the dressed system. This tunability is due to the dressed relaxation and dephasing rates which vary parametrically with the level-spacing of the original qubit and thus affect the transition properties of the dressed qubit and the susceptibility. These dressed relaxation and dephasing rates characterize the reaction of the dressed qubit to an incident probe field. We also use recent experimental data on superconducting qubits (charge, phase, and flux qubits) to demonstrate our approach and show the possibility of experimentally realizing this proposal.
Programmable window : a large-scale transparent electronic display using SPD film
Ramos, Martin (Ramos Rizo-Patron)
This research demonstrates that Suspended Particle Device (SPD) film is a viable option for the development of large-scale transparent display systems. The thesis analyzes the SPD film from an architectural display application ...
GC Commits to Transparency on Nuclear Waste Fund Fee Adequacy Decisions
Broader source: Energy.gov [DOE]
Consistent with the Administration's commitment to transparency, DOE General Counsel Scott Blake Harris has decided that all future determinations as to the adequacy of the Nuclear Waste Fund fee...
Evidence for the Onset of Color Transparency in ?0 Electroproduction off Nuclei
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Guo, L; Hanretty, C; Hicks, K; Holt, R J; Hyde, C E; Ilieva, Y; Ireland, D G; Ishkhanov, B S; Isupov, E L; Jawalker, S S; Keller, D; Khandaker, M; Kheterpal, P; Kim, A; Kim, W; Klein, A; Klein, F J; Kubarovsky, V; Kuhn, S E; Kuleshov, S V; Kuznetsov, V; Laget, J M; Lu, H Y; MacGregor, I.D. J; Mao, Y; Markov, N; Mayer, M; McAndrew, J; McKinnon, B; Meyer, C A; Mineeva, T; Mirazita, M; Mokeev, V; Moreno, B; Moutarde, H; Muneva, E; Nadel-Turonski, P; Ni, A; Niccolai, S; Niculescu, G; Niculescu, I; Osipenko, M; Ostrovidov, A I; Pappalardo, L; Paremuzyan, R; Park, K; Park, S; Pasyuk, E; Anefalos Pereira, S; Phelps, E; Pisano, S; Pozdniakov, S; Price, J W; Procureur, S; Protopopescu, D; Raue, B A; Reimer, P E; Ricco, G; Rimal, D; Ripani, M; Ritchie, B G; Rosner, G; Rossi, P; Sabatie, F; Saini, M S; Salgado, C; Schott, D; Schumacher, R A; Seraydaryan, H; Sharabian, Y G; Smith, E S; Smith, G D; Sober, D I; Sokhan, D; Stepanyan, S S; Stepanyan, S; Stoler, P; Strauch, S; Taiuti, M; Tang, W; Taylor, C E; Tedeschi, D J; Tkachenko, S; Ungaro, M; Vernarsky, B; Vineyard, M F; Voskanyan, H; Voutier, E; Watts, D; Weinstein, L B; Weygand, D P; Wood, M H; Zachariou, N; Zhao, B; Zhao, Z W
We have measured the nuclear transparency of the incoherent diffractive A(e,e'?0) process in 12C and 56Fe targets relative to 2H using a 5 GeV electron beam. The nuclear transparency, the ratio of the produced {rho}{sup 0}'s on a nucleus relative to deuterium, which is sensitive to ?A interaction, was studied as function of the coherence length (Ic), a lifetime of the hadronic fluctuation of the virtual photon, and the four-momentum transfer squared (Q2). While the transparency for both 12C and 56Fe showed no Ic dependence, a significant Q2 dependence was measured, which is consistent with calculations that included the color transparency effects.
Synthesis of mono-to-multi-layer graphene for transparent electrode applications
Choi, Minseok
In this thesis, mono-to-multilayer graphene for transparent electrode applications was synthesized by Atmospheric Pressure Chemical Vapor Deposition (APCVD) and the key factors that determine the electrical and optical ...
Patternable transparent carbon nanotube films for electrochromic devices Liangbing Hu and George Grunera
Gruner, George
Patternable transparent carbon nanotube films for electrochromic devices Liangbing Hu and George nanotube films on polyethylene terephthalate as flexible electrodes in electrochromic devices using. Electrochromic devices attract much interest due to their potential use in applications such as smart windows
Polymer material selection and testing of resistive wire arrangement for a transparent infant warming blanket
Salazar, Madeline
The ThermoCloud was designed as a portable, scalable, transparent electrical blanket to warm and insulate infants, while permitting hassle-free medical transportation and maximum visualization of a patient's thorax and ...
Evidence for the Onset of Color Transparency in $?^0$ Electroproduction off Nuclei
L. El Fassi; L. Zana; K. Hafidi; M. Holtrop; B. Mustapha; W. K. Brooks; H. Hakobyan; X. Zheng; K. P. Adhikari; D. Adikaram; M. Aghasyan; M. J. Amaryan; M. Anghinolfi; J. Arrington; H. Avakian; H. Baghdasaryan; M. Battaglieri; V. Batourine; I. Bedlinskiy; A. S. Biselli; C. Bookwalter; D. Branford; W. J. Briscoe; S. Bultmann; V. D. Burkert; D. S. Carman; A. Celentano; S. Chandavar; P. L. Cole; M. Contalbrigo; V. Crede; A. D'Angelo; A. Daniel; N. Dashyan; R. De Vita; E. De Sanctis; A. Deur; B. Dey; R. Dickson; C. Djalali; G. E. Dodge; D. Doughty; R. Dupre; H. Egiyan; A. El Alaoui; L. Elouadrhiri; P. Eugenio; G. Fedotov; S. Fegan; M. Y. Gabrielyan; M. Garcon; N. Gevorgyan; G. P. Gilfoyle; K. L. Giovanetti; F. X. Girod; J. T. Goetz; W. Gohn; E. Golovatch; R. W. Gothe; K. A. Griffioen; M. Guidal; L. Guo; C. Hanretty; D. Heddle; K. Hicks; R. J. Holt; C. E. Hyde; Y. Ilieva; D. G. Ireland; B. S. Ishkhanov; E. L. Isupov; S. S. Jawalkar; D. Keller; M. Khandaker; P. Khetarpal; A. Kim; W. Kim; A. Klein; F. J. Klein; V. Kubarovsky; S. E. Kuhn; S. V. Kuleshov; V. Kuznetsov; J. M. Laget; H. Y. Lu; I. J. D. MacGregor; Y. Mao; N. Markov; M. Mayer; J. McAndrew; B. McKinnon; C. A. Meyer; T. Mineeva; M. Mirazita; V. Mokeev; B. Moreno; H. Moutarde; E. Munevar; P. Nadel-Turonski; A. Ni; S. Niccolai; G. Niculescu; I. Niculescu; M. Osipenko; A. I. Ostrovidov; L. Pappalardo; R. Paremuzyan; K. Park; S. Park; E. Pasyuk; S. Anefalos Pereira; E. Phelps; S. Pisano; S. Pozdniakov; J. W. Price; S. Procureur; D. Protopopescu; B. A. Raue; P. E. Reimer; G. Ricco; D. Rimal; M. Ripani; B. G. Ritchie; G. Rosner; P. Rossi; F. Sabatie; M. S. Saini; C. Salgado; D. Schott; R. A. Schumacher; H. Seraydaryan; Y. G. Sharabian; E. S. Smith; G. D. Smith; D. I. Sober; D. Sokhan; S. S. Stepanyan; S. Stepanyan; P. Stoler; S. Strauch; M. Taiuti; W. Tang; C. E. Taylor; D. J. Tedeschi; S. Tkachenko; M. Ungaro; B . Vernarsky; M. F. Vineyard; H. Voskanyan; E. Voutier; D. Watts; L. B. Weinstein; D. P. Weygand; M. H. Wood; N. Zachariou; B. Zhao; Z. W. Zhao
We have measured the nuclear transparency of the incoherent diffractive $A(e,e'\\rho^0)$ process in $^{12}$C and $^{56}$Fe targets relative to $^2$H using a 5 GeV electron beam. The nuclear transparency, the ratio of the produced $\\rho^0$'s on a nucleus relative to deuterium, which is sensitive to $\\rho A$ interaction, was studied as function of the coherence length ($l_c$), a lifetime of the hadronic fluctuation of the virtual photon, and the four-momentum transfer squared ($Q^2$). While the transparency for both $^{12}$C and $^{56}$Fe showed no $l_c$ dependence, a significant $Q^2$ dependence was measured, which is consistent with calculations that included the color transparency effects.
Transparent hydrogel with enhanced water retention capacity by introducing highly hydratable salt
Suo, Zhigang
Transparent hydrogel with enhanced water retention capacity by introducing highly hydratable salt 2014; published online 14 October 2014) Polyacrylamide hydrogels containing salt as electrolyte have of polyacrylamide hydrogel by introducing highly hydratable salts into the hydrogel. These hydrogels show enhanced
Transparent and Conductive Carbon Nanotube Multilayer Thin Films Suitable as an Indium Tin Oxide Replacement
Park, Yong Tae
and light-emitting diodes). For these electronic devices, transporting electrons to and from the electrode layer is required. In many cases, this electrode must transmit visible light because it is applied directly onto the surface of a transparent...
Demonstration of a hitless bypass switch using nanomechanical perturbation for high-bitrate transparent networks
Chatterjee, Rohit
We demonstrate an optical hitless bypass switch based on nanomechanical proximity perturbation for high-bitrate transparent networks. Embedded in a single-level ?-imbalanced Mach-Zehnder interferometer, the two ...
Transparent, near-infrared organic photovoltaic solar cells for window and energy-scavenging applications
Lunt, Richard R.
We fabricate near-infrared absorbing organic photovoltaics that are highly transparent to visible light. By optimizing near-infrared optical-interference, we demonstrate power efficiencies of 1.3Ý0.1% with simultaneous ...
Measurement of nuclear transparency from A(e,e'[pi]?) reactions
Clasie, Benjamin Michael Patrick
The color transparency phenomenon refers to the suppression of final-state interactions of a hadron propagating through the nuclear medium at large momentum transfer when the hadron is produced with small transverse size. ...
Thick and Thin Film Polymer CNT Nanocomposites for Thermoelectric Energy Conversion and Transparent Electrodes
Fisher, Frank
Thick and Thin Film Polymer ôÙ CNT Nanocomposites for Thermoelectric Energy Conversion gradient. Thermoelectric materials harvest electricity from waste heat or any temperature gradient]. The PDDA/(SWNT+DOC) system produced transparent (> 82% visible light transmittance) and electrically
Experimental demonstration of a broadband all-dielectric metamaterial perfect reflector Parikshit Moitra, Brian A. Slovick, Zhi Gang Yu, S. Krishnamurthy, and Jason Valentine
Simaan, Nabil
-silicon metamaterial with hyperbolic transition in near infrared Appl. Phys. Lett. 103, 021905 (2013); 10 a correlation between the degree of disorder and the reduction in reflectance. It is shown that near-unity reflection is preserved as long as resonator interaction is avoided. Realization of near-unity reflection
Color transparency and high-energy ( p ,2 p ) nuclear reactions
Lee, T.H. (Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)); Miller, G.A. (Department of Physics FM-15, University of Washington, Seattle, Washington 98195 (United States))
Predictions relevant for exploring color transparency in ({ital p},2{ital p}) nuclear reactions are often made by using simplified treatments of nuclear dynamics. We examine the extent to which the earlier predictions are valid by carrying out calculations using an improved treatment of the proton scattering wave functions, nucleon Fermi motion, and the effects of long- and short-range nuclear correlations. The consequences of two existing models of color transparency are also presented.
Magnetic transparent conducting oxide film and method of making
Windisch Jr., Charles F.; Exarhos, Gregory J.; Sharma, Shiv K.
Cobalt-nickel oxide films of nominal 100 nm thickness, and resistivity as low as 0.06 .OMEGA..multidot.cm have been deposited by spin-casting from both aqueous and organic precursor solutions followed by annealing at 450.degree. C. in air. Films deposited on sapphire substrates exhibit a refractive index of about 1.7 and are relatively transparent in the wavelength region from 0.6 to 10.0 .mu.m. They are also magnetic. The electrical and spectroscopic properties of the oxides have been studied as a function of x=Co/(Co+Ni) ratio. An increase in film resistivity was found upon substitution of other cations (e.g., Zn.sup.2+, Al.sup.3+) for Ni in the spinel structure. However, some improvement in the mechanical properties of the films resulted. On the other hand, addition of small amounts of Li decreased the resistivity. A combination of XRD, XPS, UV/Vis and Raman spectroscopy indicated that NiCo.sub.2 O.sub.4 is the primary conducting component and that the conductivity reaches a maximum at this stoichiometry. When x<0.67, NiO forms leading to an increase in resistivity; when x>0.67, the oxide was all spinel but the increased Co content lowered the conductivity. The influence of cation charge state and site occupancy in the spinel structure markedly affects calculated electron band structures and contributes to a reduction of p-type conductivity, the formation of polarons, and the reduction in population of mobile charge carriers that tend to limit transmission in the infrared.
Transparent building-integrated PV modules. Phase 1: Comprehensive report
This Comprehensive Report encompasses the activities that have been undertaken by Kiss + Cathcart, Architects, in conjunction with Energy Photovoltaics, Incorporated (EPV), to develop a flexible patterning system for thin-film photovoltaic (PV) modules for building applications. There are two basic methods for increasing transparency/light transmission by means of patterning the PV film: widening existing scribe lines, or scribing a second series of lines perpendicular to the first. These methods can yield essentially any degree of light transmission, but both result in visible patterns of light and dark on the panel surface. A third proposed method is to burn a grid of dots through the films, independent of the normal cell scribing. This method has the potential to produce a light-transmitting panel with no visible pattern. Ornamental patterns at larger scales can be created using combinations of these techniques. Kiss + Cathcart, Architects, in conjunction with EPV are currently developing a complementary process for the large-scale lamination of thin-film PVs, which enables building integrated (BIPV) modules to be produced in sizes up to 48 in. x 96 in. Flexible laser patterning will be used for three main purposes, all intended to broaden the appeal of the product to the building sector: To create semitransparent thin-film modules for skylights, and in some applications, for vision glazing.; to create patterns for ornamental effects. This application is similar to fritted glass, which is used for shading, visual screening, graphics, and other purposes; and to allow BIPV modules to be fabricated in various sizes and shapes with maximum control over electrical characteristics.
The new geospatial tools: global transparency enhancing safeguards verification
Pabian, Frank Vincent [Los Alamos National Laboratory
This paper focuses on the importance and potential role of the new, freely available, geospatial tools for enhancing IAEA safeguards and how, together with commercial satellite imagery, they can be used to promote 'all-source synergy'. As additional 'open sources', these new geospatial tools have heralded a new era of 'global transparency' and they can be used to substantially augment existing information-driven safeguards gathering techniques, procedures, and analyses in the remote detection of undeclared facilities, as well as support ongoing monitoring and verification of various treaty (e.g., NPT, FMCT) relevant activities and programs. As an illustration of how these new geospatial tools may be applied, an original exemplar case study provides how it is possible to derive value-added follow-up information on some recent public media reporting of a former clandestine underground plutonium production complex (now being converted to a 'Tourist Attraction' given the site's abandonment by China in the early 1980s). That open source media reporting, when combined with subsequent commentary found in various Internet-based Blogs and Wikis, led to independent verification of the reporting with additional ground truth via 'crowdsourcing' (tourist photos as found on 'social networking' venues like Google Earth's Panoramio layer and Twitter). Confirmation of the precise geospatial location of the site (along with a more complete facility characterization incorporating 3-D Modeling and visualization) was only made possible following the acquisition of higher resolution commercial satellite imagery that could be correlated with the reporting, ground photos, and an interior diagram, through original imagery analysis of the overhead imagery.
Enhanced Diffraction from a Grating on the Surface of a Negative-Index Metamaterial D. R. Smith, P. M. Rye, J. J. Mock, D. C. Vier, and A. F. Starr
Nemat-Nasser, Sia
Enhanced Diffraction from a Grating on the Surface of a Negative-Index Metamaterial D. R. Smith, P be carefully reexamined in the context of negative-index media. For example, in an analysis of the imaging
Communiquer dans un monde de normes l 198 Boutaud J-J. (2005), La transparence, nouveau rgime visible , Transparence & communication, MEI, n 22, Paris, L'Harmattan,
Paris-Sud XI, Universitûˋ de
visible ô£, Transparence & communication, MEI, nô¯ 22, Paris, L'Harmattan, pp. 1-7. Debord G. (1967), La communication, Paris, L'Harmattan, pp. 207-225. Introduction La communication proposûˋe s'inscrit dans la
Dr. John S. Hurley
In this study, we focus on the examination of ac losses in conductors utilizing Bi{sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O [BSCCO (2223)] high TC superconductors (HTS). In addition, we seek to assist other facilities such as the University of Wisconsin-Madison Applied Superconductivity Center (UW-ASC), Brookhaven National Laboratory, and other DoE facilities investigating the use of HTS in electric power applications (e.g., generators, motors, and transformers). To accomplish this we will develop an ac losses capability at Clark Atlanta University to complement the established ac losses efforts at Brookhaven National Laboratory (BSCCO) on BSCCO/Ag and various material characterization efforts taking place at the UW-ASC. Our goal is through this effort to gain a greater understanding of the effects on ac losses due to parameters such as ac/dc current, J{sub c}, tape geometry, voltage tap placement, field orientation, material anisotropy, surface irregularities, percolations and filament coupling effects. As a result, we expect to better understand how to minimize ac losses in applications requiring real or practical conductors. HTS conductors based on BSCCO-2223 are now being routinely produced in industrial lengths of high quality. Vendors such as Southwire and ASC are producing multi-filamentary tapes in lengths of 6 km or more carrying critical current densities of up to 3 kA/cm**2 at 77 K. While this is approaching the level of performance where some large-scale applications are considered to be economically viable, a number of problems remain to be solved. The remaining issues include: rapid reduction in JC in magnetic fields; and power dissipation due to varying magnetic fields or currents (ac losses).
Local structure analysis of solid state ionic conductors, perovskite-derived structures by NMR and computational studies
Dervisoglu, Riza
, supportive, encouraging, and patient wife Gulay. Despite the physical distance I have felt her comforting presence by my side throughout all these years. Thank you. Abstract In this work, local environments of ions in solid oxide fuel cell (SOFC) elec... conductors so as to develop new materials for use in solid state devices such as Solid Oxide Fuel Cells (SOFCs), sensors and gas separation membranes.(Shewmon [29], Julien and Nazri [30], Kharton et al. [31], Tillement [32]) SOFCs have the potential to be a...
Stress-induced martensitic transformation during tensile test of full-size TF conductor jacket tube at 4.2 K
Yang, H. H.; Li, S. P. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P.R. China and University of Chinese Academy of Sciences Beijing, 100049, P.R. (China); Wu, Z. X.; Huang, C. J.; Huang, R. J.; Li, L. F. [Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing, 100190, P.R. (China)
The toroidal-field (TF) conductor jacket of International Thermonuclear Experimental Reactor (ITER) is made of modified 316LN stainless steel, which is influenced by heat treatment at approximately 650 ¯C for 200 h to produce Nb{sub 3}Sn superconducting materials at the final stage. Due to the high electromagnetic forces arising during magnet operation, higher mechanical properties of the jacket materials at cryogenic temperatures are required. In our work, mechanical properties of the full-size TF conductor jacket tube were investigated, which satisfied the ITER requirements. Stress-induced martensitic transformation mechanism during tensile test of the conductor jacket material at 4.2 K was characterized by means of in-situ temperature dependent XRD, vibrating sample magnetometer (VSM) and in conjunction with transmission electron microscopy (TEM). The tensile behavior related to the amount of stress-induced phase transformation at cryogenic temperature was also discussed.
Roebel cables from REBCO coated conductors: a one-century-old concept for the superconductivity of the future
Goldacker, Wilfried; Pardo, Enric; Kario, Anna; Schlachter, Sonja I; Vojenciak, Michal
Energy applications employing high-temperature superconductors (HTS), such as motors/generators, transformers, transmission lines and fault current limiters, are usually operated in the alternate current (AC) regime. In order to be efficient, the HTS devices need to have a sufficiently low value of AC loss, in addition to the necessary current-carrying capacity. Most applications are operated with currents beyond the current capacity of single conductors and consequently require cabled conductor solutions with much higher current carrying capacity, from a few kA to up to 20-30 kA for large hydro-generators. A century ago, in 1914, Ludwig Roebel invented a low-loss cable design for copper cables, which was successively named after him. The main idea behind Roebel cables is to separate the current in different strands and to provide a full transposition of the strands along the cable direction. Nowadays, these cables are commonly used in the stator of large generators. Based on the same design concept of their ...
Energy Dependence of Nuclear Transparency in C(p,2p) Scattering
A. Leksanov; J. Alster; G. Asryan; Y. Averichev; D. Barton; V. Baturin; N. Bukhtoyarova; A. Carroll; S. Heppelmann; T. Kawabata; Y. Makdisi; E. Minina; I. Navon; A. Malki; H. Nicholson; A. Ogawa; Yu. Panebratsev; E. Piasetzky; A. Schetkovsky; S. Shimanskiy; A. Tang; J. W. Watson; H. Yoshida; D. Zhalov
The transparency of carbon for (p,2p) quasi-elastic events was measured at beam energies ranging from 6 to 14.5 GeV at 90 degrees c.m. The four momentum transfer squared q*q ranged from 4.8 to 16.9 (GeV/c)**2. We present the observed energy dependence of the ratio of the carbon to hydrogen cross sections. We also apply a model for the nuclear momentum distribution of carbon to normalize this transparency ratio. We find a sharp rise in transparency as the beam energy is increased to 9 GeV and a reduction to approximately the Glauber level at higher energies.
Control of microwave signals using bichromatic electromechanically induced transparency in three-mode circuit electromechanical systems
Cheng Jiang; Yuanshun Cui; Xiaowei Li
We theoretically investigate the tunable slowing and advancing of microwave signals based on bichromatic electromechanically induced transparency in a three-mode circuit electromechanical system, where two mechanical oscillators with closely spaced frequencies are independently coupled to a common microwave cavity. In the presence of a strong microwave pump field, we obtain two transparency windows accompanied by steep phase dispersion in the transmitted microwave probe field. The width of the transparency window and the group delay of the probe field can be controlled effectively by the power of the pump field. It is shown that the maximum group delay of 0.12 ms and the advance of 0.27 ms can be obtained in the current experiments.
Performance of Europium-Doped Strontium Iodide, Transparent Ceramics and Bismuth-loaded Polymer Scintillators
Cherepy, N J; Payne, S A; Sturm, B W; O'Neal, S P; Seeley, Z M; Drury, O B; Haselhorst, L K; Rupert, B L; Sanner, R D; Thelin, P A; Fisher, S E; Hawrami, R; Shah, K S; Burger, A; Ramey, J O; Boatner, L A
Recently discovered scintillators for gamma ray spectroscopy, single crystal SrI{sub 2}(Eu), GYGAG(Ce) transparent ceramic and Bismuth-loaded plastics, offer resolution and fabrication advantages compared to commercial scintillators, such as NaI(Tl) and standard PVT plastic. Energy resolution at 662 keV of 2.7% is obtained with SrI{sub 2}(Eu), while 4.5% is obtained with GYGAG(Ce). A new transparent ceramic scintillator for radiographic imaging systems, GLO(Eu) offers high light yield of 70,000 Photons/MeV, high stopping, and low radiation damage. Implementation of single crystal SrI{sub 2}(Eu), Gd-based transparent ceramics, and Bi-loaded plastic scintillators can advance the state-of-the art in ionizing radiation detection systems.
Transparent ultralow-density silica aerogels prepared by a two-step sol-gel process
Tillotson, T.M.; Hrubesh, L.W.
Conventional silica sol-gel chemistry is limited for the production of transparent ultralow-density aerogels because (1) gelation is either slow or unachievable, and (2) even when gelation is achieved, the large pore sizes result in loss of transparency for aerogels <.020 g/cc. We have developed a two-step sol-gel process that circumvents the limitations of the conventional process and allows the formation of ultralow-density gels in a matter of hours. we have found that the gel time is dependent on the catalyst concentration. After supercritical extraction, the aerogels are transparent, uncracked tiles with densities as low as .003 g/cc. 6 figs., 11 refs.
Atomic-Layer-Deposited Transparent Electrodes for Silicon Heterojunction Solar Cells
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Demaurex, Benedicte; Seif, Johannes P.; Smit, Sjoerd; Macco, Bart; Kessels, W. M.; Geissbuhler, Jonas; De Wolf, Stefaan; Ballif, Christophe
We examine damage-free transparent-electrode deposition to fabricate high-efficiency amorphous silicon/crystalline silicon heterojunction solar cells. Such solar cells usually feature sputtered transparent electrodes, the deposition of which may damage the layers underneath. Using atomic layer deposition, we insert thin protective films between the amorphous silicon layers and sputtered contacts and investigate their effect on device operation. We find that a 20-nm-thick protective layer suffices to preserve, unchanged, the amorphous silicon layers beneath. Insertion of such protective atomic-layer-deposited layers yields slightly higher internal voltages at low carrier injection levels. However, we identify the presence of a silicon oxide layer, formed during processing,more £between the amorphous silicon and the atomic-layer-deposited transparent electrode that acts as a barrier, impeding hole and electron collection.¨ less
Atomic-Layer-Deposited Transparent Electrodes for Silicon Heterojunction Solar Cells
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Demaurex, Benedicte; Seif, Johannes P.; Smit, Sjoerd; Macco, Bart; Kessels, W. M.; Geissbuhler, Jonas; De Wolf, Stefaan; Ballif, Christophe
We examine damage-free transparent-electrode deposition to fabricate high-efficiency amorphous silicon/crystalline silicon heterojunction solar cells. Such solar cells usually feature sputtered transparent electrodes, the deposition of which may damage the layers underneath. Using atomic layer deposition, we insert thin protective films between the amorphous silicon layers and sputtered contacts and investigate their effect on device operation. We find that a 20-nm-thick protective layer suffices to preserve, unchanged, the amorphous silicon layers beneath. Insertion of such protective atomic-layer-deposited layers yields slightly higher internal voltages at low carrier injection levels. However, we identify the presence of a silicon oxide layer, formed during processing, between the amorphous silicon and the atomic-layer-deposited transparent electrode that acts as a barrier, impeding hole and electron collection.
The Use of Large Transparent Ceramics in a High Powered, Diode Pumped Solid State Laser
Yamamoto, R; Bhachu, B; Cutter, K; Fochs, S; Letts, S; Parks, C; Rotter, M; Soules, T
The advent of large transparent ceramics is one of the key enabling technological advances that have shown that the development of very high average power compact solid state lasers is achievable. Large ceramic neodymium doped yttrium aluminum garnet (Nd:YAG) amplifier slabs are used in Lawrence Livermore National Laboratory's (LLNL) Solid State Heat Capacity Laser (SSHCL), which has achieved world record average output powers in excess of 67 kilowatts. We will describe the attributes of using large transparent ceramics, our present system architecture and corresponding performance; as well as describe our near term future plans.
Electronic Durability of Flexible Transparent Films from Type-Specific Single-Wall Carbon Nanotubes
Harris, J; Iyer, S; Bernhardt, A; Huh, JY; Hudson, S; Fagan, J; Hobbie, E.
The coupling between mechanical flexibility and electronic performance is evaluated for thin films of metallic and semiconducting single-wall carbon nanotubes (SWCNTs) deposited on compliant supports. Percolated networks of type-purified SWCNTs are assembled as thin conducting coatings on elastic polymer substrates, and the sheet resistance is measured as a function of compression and cyclic strain through impedance spectroscopy. The wrinkling topography, microstructure and transparency of the films are independently characterized using optical microscopy, electron microscopy, and optical absorption spectroscopy. Thin films made from metallic SWCNTs show better durability as flexible transparent conductive coatings, which we attribute to a combination of superior mechanical performance and higher interfacial conductivity.
Three-terminal resistive switching memory in a transparent vertical-configuration device
Ungureanu, Mariana; Llopis, Roger [CIC nanoGUNE Consolider, Donostia - San Sebastian (Spain)] [CIC nanoGUNE Consolider, Donostia - San Sebastian (Spain); Casanova, FÒlix; Hueso, Luis E. [CIC nanoGUNE Consolider, Donostia - San Sebastian (Spain) [CIC nanoGUNE Consolider, Donostia - San Sebastian (Spain); Ikerbasque, Basque Foundation for Science, Bilbao (Spain)
The resistive switching phenomenon has attracted much attention recently for memory applications. It describes the reversible change in the resistance of a dielectric between two non-volatile states by the application of electrical pulses. Typical resistive switching memories are two-terminal devices formed by an oxide layer placed between two metal electrodes. Here, we report on the fabrication and operation of a three-terminal resistive switching memory that works as a reconfigurable logic component and offers an increased logic density on chip. The three-terminal memory device we present is transparent and could be further incorporated in transparent computing electronic technologies.
Sun-tracking optical element realized using thermally activated transparency-switching material
Apostoleris, Harry; Lilliu, Samuele; Chiesa, Matteo
We present a proof of concept demonstration of a novel optical element: a light-responsive aperture that can track a moving light beam. The element is created using a thermally-activated transparency-switching material composed of paraffin wax and polydimethylsiloxane (PDMS). Illumination of the material with a focused beam causes the formation of a localized transparency at the focal spot location, due to local heating caused by absorption of a portion of the incident light. An application is proposed in a new design for a self-tracking solar collector.
Electromagnetically induced transparency from two-phonon processes in quadratically coupled membranes
Huang, Sumei; Agarwal, G. S. [Department of Physics, Oklahoma State University, Stillwater, Oklahoma 74078 (United States)
We describe how electromagnetically induced transparency can arise in quadratically coupled optomechanical systems. Due to quadratic coupling, the underlying optical process involves a two-phonon process in an optomechanical system, and this two-phonon process makes the mean displacement, which plays the role of atomic coherence in traditional electromagnetically induced transparency (EIT), zero. We show how the fluctuation in displacement can play a role similar to atomic coherence and can lead to EIT-like effects in quadratically coupled optomechanical systems. We show how such effects can be studied using the existing optomechanical systems.
JOURNAL DE PHYSIQUE Co[loqueC6, supplkment au no 7, Tome 41, Juillet 1980,page C6-17 FAST /ON CONDUCTORS.
Boyer, Edmond
CONDUCTORS. Quasielastic neutron scattering from a single crystal of a-AgI K. Funke (*), A. Hoch and R. E on a quasielastic neutron scattering experiment performed on a large single crystal of a-AgI. Time-of-flight spectra. - In this paper we give a first report on a quasielastic neutron scattering experiment performed on a large single
Nuclear magnetism and electron order in interacting one-dimensional conductors Bernd Braunecker,1 Pascal Simon,2 and Daniel Loss1
Braunecker, Bernd
Nuclear magnetism and electron order in interacting one-dimensional conductors Bernd Braunecker,1 to each other. We show here that this occurs when a lattice of nuclear spins is embedded in a Luttinger the nuclear spin and the conduction electron spin is very weak; yet it triggers a strong feedback reaction
PV OCPD + Main OCPD 1.2 R, where R is the ampacity of the conductor or the bus bar rating.
Johnson, Eric E.
available (from either the utility through the main breaker or from the PV system through the back-fed PV applies to the supply overcurrent devices on any conductor. If the PV inverter OCPD cannot be located common connection used for PV systems smaller than 10 kW. Section 690.64(B)--moving to 705.12(D
Service Entrance Conductor Taps for Utility-Interactive Inverter Systems Section 690.64 of the National Electrical Code (NEC) establishes how and where a utility-
Johnson, Eric E.
1 of 3 Service Entrance Conductor Taps for Utility-Interactive Inverter Systems Section 690.64 of the National Electrical Code (NEC) establishes how and where a utility- interactive PV system may be connected or in a group of enclosures. The PV system may be counted as a separate service (230.2) and could have up to six
IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 21, NO. 3, JUNE 2011 2529 Development of a Multifilament PIT V3GaConductor
. The prospect of sustainable fusion technology has spurred projects like the International Thermonuclear Ex of a Multifilament PIT V3GaConductor for Fusion Applications J. S. Distin, L. R. Motowidlo, P. J. Lee, D. C on V3Gaassert its suitability for use in proposed fusion reactors. V3Ga may outperform Nb3Sn
Homogeneous superconducting state at 8.1 K under ambient pressure in the organic conductor 03B2-(BEDT-TTF)2I3
Boyer, Edmond
L-1079 Homogeneous superconducting state at 8.1 K under ambient pressure in the organic conductor of the first narrow and complete superconducting transition yet obtained in 03B2-(BEDT-TTF)2I3 at 8.1 K superconductivity at ambient pressure is not stable above 250 K. J. Physique Lett. 46 (1985) L-1079 - L-1085 15
Characterization of a high-temperature superconducting conductor on round core cables in magnetic fields up to 20 T
van der Laan, Danko [Advanced Conductor Technologies; Noyes, Patrick [National High Magnetic Field Laboratory; Miller, George [National High Magnetic Field Laboratory; Weijers, Hubertus [National High Magnetic Field Laboratory; Willering, Gerard [CERN
The next generation of high-ÿ˜eld magnets that will operate at magnetic ÿ˜elds substantially above 20 T, or at temperatures substantially above 4.2 K, requires high-temperature superconductors (HTS). Conductor on round core (CORC) cables, in which RE-Ba{sub 2}Cu{sub 3}O{sub 7-{delta}} (RE = rare earth) (REBCO) coated conductors are wound in a helical fashion on a fl?exible core, are a practical and versatile HTS cable option for low-inductance, high-field magnets. We performed the first tests of CORC magnet cables in liquid helium in magnetic fields of up to 20 T. A record critical current I{sub c} of 5021 A was measured at 4.2 K and 19 T. In a cable with an outer diameter of 7.5 mm, this value corresponds to an engineering current density J{sub e} of 114 A mm{sup -2} , the highest J{sub e} ever reported for a superconducting cable at such high magnetic fields. Additionally, the first magnet wound from an HTS cable was constructed from a 6 m-long CORC cable. The 12-turn, double-layer magnet had an inner diameter of 9 cm and was tested in a magnetic field of 20 T, at which it had an I{sub c} of 1966 A. The cables were quenched repetitively without degradation during the measurements, demonstrating the feasibility of HTS CORC cables for use in high-field magnet applications.
Photoactive transparent nano-crystalline glass-ceramic for remazole red dye degradation
Gad-Allah, Tarek A., E-mail: firstname.lastname@example.com [Water Pollution Research Department, National Research Centre, Cairo 12311 (Egypt); Margha, Fatma H. [Department of Glass Research, National Research Centre, Cairo 12311 (Egypt)] [Department of Glass Research, National Research Centre, Cairo 12311 (Egypt)
Graphical abstract: Display Omitted Highlights: ? Preparation and characterization of novel transparent nanocrystalline glass-ceramic. ? Precipitation of photoactive phases by using controlled heat-treatment. ? Conservation of transparency along with photoactivity. ? Using the prepared nanocrystalline glass-ceramic in water purification. -- Abstract: Transparent glass ceramic material was prepared from alkali-borosilicate glass containing titania by proper heat treatment scheme. The prepared samples were characterized using differential thermal analysis, X-ray diffraction, transmission electron microscope, selected area electron diffraction and UVvisible spectroscopy. The applied heat treatment program allowed the crystallization of nano-crystalline anatase, rutile, barium titanate, titanium borate and silicate phases while maintaining the transparency. The precipitated nano-crystalline anatase and rutile phases were responsible for the observed high photocatalytic activity of the prepared samples. Samples of 24.29 and 32.39 TiO{sub 2} wt% showed better efficiency for the decolorization of remazole red dye compared with commercial-TiO{sub 2} used in preparation of glass-ceramic. The reuse of prepared glass-ceramic photocatalyst with nearly same efficiency for different times was also proved.
What is the Transparent, Activity-Based Budget System and why is it being done?
Saskatchewan, University of
What is the Transparent, Activity-Based Budget System and why is it being done? This project, and systematic way; link budgets to cycles of integrated planning; ensure resources are put behind strategic Planning (PCIP) in financial decision-making; ñ NOT result in zero-based budgeting (zero-based budgeting
Hair Self Shadowing and Transparency Depth Ordering Using Occupancy maps Erik Sintorn
Assarsson, Ulf
approximate visibility function for high frequency semi- transparent geometry such as hair. We can then reconstruct the vis- ibility for any fragment without the expensive compression needed by Deep Shadow Maps cylinders or as line primitives, the two main challenges are the self-shadowing effects within the volume
On-cue detachment of hydrogels and cells from optically transparent electrodesw
Revzin, Alexander
of composition or conformation of self-assembled molecules is to remove these molecules altogether) is optically transparent yet conductive material that is well-suited for cell cultivation and observation was highly significant because it permitted both spatial and temporal control over the release of polymer
Impact of degenerate n-doping on the optical absorption edge in transparent conducting cadmium oxide
Schleife, AndrÕ
n-type or can be heavily doped. Transparent conductive cadmium oxide (CdO) thin films, for instance devices or modern solar cells, material performance is critically important. A combination of high in the conduction bands of CdO can increase the conductivity up to values desired for technological applications
RemusDB: Transparent High Availability for Database Umar Farooq Minhas
Aboulnaga, Ashraf
system (DBMS). The proposed tech- nique can be applied to any DBMS with little or no customization transparent HA and failover capabilities. We show that while Remus and similar systems can protect a DBMS, database workloads incur a performance overhead of up to 32% as compared to an unprotected DBMS. We
Highly transparent Nb-doped indium oxide electrodes for organic solar cells
Kim, Jun Ho; Seong, Tae-Yeon [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Na, Seok-In [Professional Graduate School of Flexible and Printable Electronics, Chonbuk National University, 664-14, Deokjin-dong, Jeongju-si, Jellabuk-do 561-756 (Korea, Republic of); Chung, Kwun-Bum [Department of Physics, Dankook University, Mt. 29, Anseo-Dong, Chenan 330-714 (Korea, Republic of); Lee, Hye-Min; Kim, Han-Ki, E-mail: firstname.lastname@example.com [Department of Advanced Materials Engineering for Information and Electronics, Kyung Hee University, 1 Seocheon-dong, Yongin, Gyeonggi-do 446-701 (Korea, Republic of)
The authors investigated the characteristics of Nb-doped In{sub 2}O{sub 3} (INbO) films prepared by co-sputtering of Nb{sub 2}O{sub 5} and In{sub 2}O{sub 3} for use in transparent anodes for organic solar cells (OSCs). To optimize the Nb dopant composition in the In{sub 2}O{sub 3} matrix, the effect of the Nb doping power on the resistivity and transparency of the INbO films were examined. The electronic structure and microstructure of the INbO films were also investigated using synchrotron x-ray absorption spectroscopy and x-ray diffraction examinations in detail. At the optimized Nb co-sputtering power of 30?W, the INbO film exhibited a sheet resistance of 15??/sq, and an optical transmittance of 86.04% at 550?nm, which are highly acceptable for the use as transparent electrodes in the fabrication of OSCs. More importantly, the comparable power conversion efficiency (3.34%) of the OSC with an INbO anode with that (3.31%) of an OSC with a commercial ITO anode indicates that INbO films are promising as a transparent electrode for high performance OSCs.
Integration of Laser-Welded Ag Nanowire Transparent Conducting Layers on Photovoltaic Devices (DMR-0819860)
Petta, Jason
Integration of Laser-Welded Ag Nanowire Transparent Conducting Layers on Photovoltaic Devices (DMR conducting layers in applications ranging from organic flexible electronics to rigid photovoltaics. However of a hybrid organic photovoltaic device [1]. The NWs are dispersed on the device and the network is welded
Hematite-based Photo-oxidation of Water Using Transparent Distributed Current Collectors
Hematite-based Photo-oxidation of Water Using Transparent Distributed Current Collectors Shannon C. Martinson*,, Argonne-Northwestern Solar Energy Research (ANSER) Center and Ï Department of Chemistry collection of photocurrent from ultrathin coatings of hematite layers, enabling the formation of photoanodes
aerogels isolants transparent-super: Topics by E-print Network
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aerogels isolants transparent-super 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 Recent progress in...
Transparent Triboelectric Nanogenerators and Self-Powered Pressure Sensors Based on Micropatterned Plastic Films
Wang, Zhong L.
sensors, and artificial skins.9-12 Indeed, building flexible transparent energy con- version and storage process for energy conversion has three important steps: charge generation, charge separation, and charge States State Key Laboratory of Physical Chemistry of Solid Surfaces, Department of Chemistry, College
Reconstructing the Surface of Inhomogeneous Transparent Scenes by Scatter-Trace Photography
Toronto, University of
. W. Morris Kiriakos N. Kutulakos University of Toronto Abstract We present a new method one or more viewpoints while moving a proxi- mal light source to a 2D or 3D set of positions is that even though light trans- port within a transparent scene's interior can be exceed- ingly complex
Shock-wave generation in transparent media from ultra-fast lasers R. Bernath*a
Van Stryland, Eric
Shock-wave generation in transparent media from ultra-fast lasers R. Bernath*a , C. G. Browna , J a harmonic of the pump laser frequency. Experiments also include burst-mode operation, where a train of ultra. Aspiotisa , M. Fishera , & M. Richardsona a Laser Plasma Laboratory, College of Optics & Photonics: CREOL
NREL scientists develop robust, high-performance IZO transparent contact for CIGS solar cells.
NREL scientists develop robust, high-performance IZO transparent contact for CIGS solar cells indium gallium diselenide (CIGS) solar cell is zinc oxide (ZnO). The problem is that unprotected Zn is a lifetime-limiting problem that is currently addressed solely through encapsulation. Fundamentally improving
Flexible and transparent supercapacitor based on In2O3 nanowire/carbon nanotube heterogeneous films
Zhou, Chongwu
; accepted 17 December 2008; published online 28 January 2009 In this paper, a supercapacitor which may find applications in heads-up display, automobile wind-shield display, and conformable transparent and/or flexible energy conversion and storage units with high energy storage and power density
Development of transparent silica aerogel over a wide range of densities
Makoto Tabata; Ichiro Adachi; Yoshikazu Ishii; Hideyuki Kawai; Takayuki Sumiyoshi; Hiroshi Yokogawa
We have succeeded in developing hydrophobic silica aerogels over a wide range of densities (i.e. refractive indices). A pinhole drying method was invented to make possible producing highly transparent aerogels with entirely new region of refractive indices of 1.06-1.26. Obtained aerogels are more transparent than conventional ones, and the refractive index is well controlled in the pinhole drying process. A test beam experiment was carried out in order to evaluate the performance of the pinhole-dried aerogels as a Cherenkov radiator. A clear Cherenkov ring was successfully observed by a ring imaging Cherenkov counter. We also developed monolithic and hydrophobic aerogels with a density of 0.01 g/cm^3 (a low refractive index of 1.0026) as a cosmic dust capturer for the first time. Consequently, aerogels with any refractive indices between 1.0026 and 1.26 can be produced freely.
Development of transparent silica aerogel over a wide range of densities
Tabata, Makoto; Ishii, Yoshikazu; Kawai, Hideyuki; Sumiyoshi, Takayuki; Yokogawa, Hiroshi; 10.1016/j.nima.2010.02.241
We have succeeded in developing hydrophobic silica aerogels over a wide range of densities (i.e. refractive indices). A pinhole drying method was invented to make possible producing highly transparent aerogels with entirely new region of refractive indices of 1.06-1.26. Obtained aerogels are more transparent than conventional ones, and the refractive index is well controlled in the pinhole drying process. A test beam experiment was carried out in order to evaluate the performance of the pinhole-dried aerogels as a Cherenkov radiator. A clear Cherenkov ring was successfully observed by a ring imaging Cherenkov counter. We also developed monolithic and hydrophobic aerogels with a density of 0.01 g/cm^3 (a low refractive index of 1.0026) as a cosmic dust capturer for the first time. Consequently, aerogels with any refractive indices between 1.0026 and 1.26 can be produced freely.
Growth and optical properties of partially transparent Eu doped CaF{sub 2} ceramic
Ghosh, Manoranjan, E-mail: email@example.com; Sen, Shashwati, E-mail: email@example.com; Pitale, S. S., E-mail: email@example.com; Goutam, U. K., E-mail: email@example.com; Shinde, Seema, E-mail: email@example.com; Patra, G. D., E-mail: firstname.lastname@example.com; Gadkari, S. C., E-mail: firstname.lastname@example.com [Technical Physics Division, Bhabha Atomic Research Centre, Mumbai - 400085 (India)
Partially transparent ceramic of 2 at.% Eu doped CaF{sub 2} have been grown preferentially towards [111] direction. For this purpose, Eu doped CaF{sub 2} nanoparticles (size?12 nm) obtained by a low temperature solution growth method has been pressed at 1000¯C under vacuum. The preferentially grown ceramic shows 15% transparency within the visible range of spectrum. As confirmed by the X-ray diffraction result, the hot pressed ceramic exhibits reduced lattice volume than the nanopowder. It indicates Eu{sup 3+} as the dominant substituting ions at the Ca{sup 2+} sites of CaF{sub 2} lattice in the hot pressed ceramic material. It is corroborated by the photoluminescence results of hot pressed ceramic which shows strong red emission corresponding to Eu{sup 3+} sites. However, photoluminescence of nanopowder exhibits intense peak in the blue region of the spectrum which is characteristics of Eu2+ sites.
Cavity cooling of a trapped atom using Electromagnetically-Induced Transparency
Marc Bienert; Giovanna Morigi
A cooling scheme for trapped atoms is proposed, which combines cavity-enhanced scattering and electromagnetically induced transparency. The cooling dynamics exploits a three-photon resonance, which combines laser and cavity excitations. It is shown that relatively fast ground-state cooling can be achieved in the Lamb-Dicke regime and for large cooperativity. Efficient ground-state cooling is found for parameters of ongoing experiments.
buffer Layer Growth, the Thickness Dependence of Jc in Coated Conductors, Local Identification of Current Limiting Mechanisms and Participation in the Wire Development Group
Larbalestier, David; Hellstron, Eric; Abraimov, Dmytro
The primary thrusts of our work were to provide critical understanding of how best to enhance the current-carrying capacity of coated conductors. These include the deconstruction of Jc as a function of fim thickness, the growth of in situ films incorporating strong pinning centers and the use of a suite of position-sensitive tools that enable location and analysis of key areas where current-limiting occurs.
Color transparency after the NE18 and E665 experiments: Outllok and perspectives at CEBAF
J. Nemchik; N. N. Nikolaev; B. G. Zakharov
CEBAF is a high-luminocity factory of virtual photons with variable virtuality $Q^{2}$ and transverse size. This makes CEBAF, in particular after the energy upgrade to (8-12)GeV, an ideal facility for uncovering new phenomena, and opening new windows, at the interface of the perturbative and nonperturbative QCD. We discuss color transparency as the case for a broad program on electroproduction of vector mesons $\\rho^{0},\\,\\omega^{0},\\,\\phi^{0}$ and their radial excitations $\\rho',\\,\\omega',\\,\\phi'$ at CEBAF. We also comment on the second generation of experiments on color transparency in $^{4}He(e,e'p)$ scattering, which are also feasible at CEBAF. In 1994, we can make more reliable projections into future because our understanding of the onset of color transparency has greatly been augmented by two experiments completed in 1993:\\\\ i) no effect of CT was seen in the SLAC NE18 experiment on $A(e,e'p)$ scattering at virtualities of the exchanged photon $Q^{2} \\lsim 7$ GeV$^{2}$, \\\\ ii) strong signal of CT was observed in the FNAL E665 experiment on exclusive $\\rho^{0}$- meson production in deep inelastic scattering in the same range of $Q^{2}$. \\\\ We discuss the impact of these observations on the CEBAF experimental program. We argue they both are good news, both were anticipated theoretically, and both rule in the correct QCD mechanism of the onset of CT.
Nuclear transparency and effective kaon-nucleon cross section from the A(e,e?K+) reaction
Clasie, Benjamin Michael Patrick
We have determined the transparency of the nuclear medium to kaons from A(e,e[superscript ?]K+) measurements on [superscript 12]C, [superscript 63]Cu, and [superscript 197]Au targets. The measurements were performed at the ...
Development of epitaxial AlxSc1-xN for artificially structured metal/semiconductor superlattice metamaterials
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Sands, Timothy D.; Stach, Eric A.; Saha, Bivas; Saber, Sammy; Naik, Gururaj V.; Boltasseva, Alexandra; Kvam, Eric P.
Epitaxial nitride rocksalt metal/semiconductor superlattices are emerging as a novel class of artificially structured materials that have generated significant interest in recent years for their potential application in plasmonic and thermoelectric devices. Though most nitride metals are rocksalt, nitride semiconductors in general have hexagonal crystal structure. We report rocksalt aluminum scandium nitride (Al,Sc)N alloys as the semiconducting component in epitaxial rocksalt metal/semiconductor superlattices. The AlxSc1?xN alloys when deposited directly on MgO substrates are stabilized in a homogeneous rocksalt (single) phase when x?more £has been extended to x?xSc1?xN alloys show moderate direct bandgap bowing with a bowing parameter, B?=?1.41?Ý?0.19?eV. The direct bandgap of metastable rocksalt AlN is extrapolated to be 4.70?Ý?0.20?eV. The tunable lattice parameter, bandgap, dielectric permittivity, and electronic properties of rocksalt AlxSc1?xN alloys enable high quality epitaxial rocksalt metal/AlxSc1?xN superlattices with a wide range of accessible metamaterials properties.¨ less
Analysis of the empirical relations between visible solar radiation, the solar altitude and the transparency of the atmosphere
Garcia Occhipinti, Antonio
ANALYSIS OF THE EMPIRICAL RELATIONS BETWEEN VISUAL SOLAR RADIATION, THE SOLAR ALTITUDE AND THE TRANSPARENCY OF THE ATMOSPHERE A Thesis A. Garcia Occhipinti Submitted to the Graduate College of the Texas ARM Untverstty in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE January 1965 Major Subject: Oceanography ANALYSIS OF THE EMPIRICAL RELATIONS BETWEEN VISIBLE SOLAR RADIATION, THE SOLAR ALTITUDE AND THE TRANSPARENCY OF THE ATMOSPHERE A Thesis A. Garcia Occhipinti...
Performance Evaluation of K-DEMO Cable-in-conduit Conductors Using the Florida Electro-Mechanical Cable Model
Zhai, Yuhu
The United States ITER Project Office (USIPO) is responsible for design of the Toroidal Field (TF) insert coil, which will allow validation of the performance of significant lengths of the conductors to be used in the full scale TF coils in relevant conditions of field, current density and mechanical strain. The Japan Atomic Energy Agency (JAEA) will build the TF insert which will be tested at the Central Solenoid Model Coil (CSMC) Test facility at JAEA, Naka, Japan. Three dimensional mathematical model of TF Insert was created based on the initial design geometry data, and included the following features: orthotropic material properties of superconductor material and insulation; external magnetic field from CSMC, temperature dependent properties of the materials; pre-compression and plastic deformation in lap joint. Major geometrical characteristics of the design were preserved including cable jacket and insulation shape, mandrel outline, and support clamps and spacers. The model is capable of performing coupled structural, thermal, and electromagnetic analysis using ANSYS. Numerical simulations were performed for room temperature conditions; cool down to 4K, and the operating regime with 68kA current at 11.8 Tesla background field. Numerical simulations led to the final design of the coil producing the required strain levels on the cable, while simultaneously satisfying the ITER magnet structural design criteria.
Parameters influencing the deposition of methylammonium lead halide iodide in hole conductor free perovskite-based solar cells
Cohen, Bat-El; Gamliel, Shany; Etgar, Lioz, E-mail: firstname.lastname@example.com [Institute of Chemistry, Casali Center for Applied Chemistry, The Hebrew University of Jerusalem, Jerusalem 90400 (Israel)
Perovskite is a promising light harvester for use in photovoltaic solar cells. In recent years, the power conversion efficiency of perovskite solar cells has been dramatically increased, making them a competitive source of renewable energy. An important parameter when designing high efficiency perovskite-based solar cells is the perovskite deposition, which must be performed to create complete coverage and optimal film thickness. This paper describes an in-depth study on two-step deposition, separating the perovskite deposition into two precursors. The effects of spin velocity, annealing temperature, dipping time, and methylammonium iodide concentration on the photovoltaic performance are studied. Observations include that current density is affected by changing the spin velocity, while the fill factor changes mainly due to the dipping time and methylammonium iodide concentration. Interestingly, the open circuit voltage is almost unaffected by these parameters. Hole conductor free perovskite solar cells are used in this work, in order to minimize other possible effects. This study provides better understanding and control over the perovskite deposition through highly efficient, low-cost perovskite-based solar cells.
A Job Pause Service under LAM/MPI+BLCR for Transparent Fault Tolerance
Wang, Chao [North Carolina State University; Mueller, Frank [North Carolina State University; Engelmann, Christian [ORNL; Scott, Steven L [ORNL
Checkpoint/restart (C/R) has become a requirement for long-running jobs in large-scale clusters due to a meantime- to-failure (MTTF) in the order of hours. After a failure, C/R mechanisms generally require a complete restart of an MPI job from the last checkpoint. A complete restart, however, is unnecessary since all but one node are typically still alive. Furthermore, a restart may result in lengthy job requeuing even though the original job had not exceeded its time quantum. In this paper, we overcome these shortcomings. Instead of job restart, we have developed a transparent mechanism for job pause within LAM/MPI+BLCR. This mechanism allows live nodes to remain active and roll back to the last checkpoint while failed nodes are dynamically replaced by spares before resuming from the last checkpoint. Our methodology includes LAM/MPI enhancements in support of scalable group communicationwith fluctuating number of nodes, reuse of network connections, transparent coordinated checkpoint scheduling and a BLCR enhancement for job pause. Experiments in a cluster with the NAS Parallel Benchmark suite show that our overhead for job pause is comparable to that of a complete job restart. A minimal overhead of 5.6% is only incurred in case migration takes place while the regular checkpoint overhead remains unchanged. Yet, our approach alleviates the need to reboot the LAM run-time environment, which accounts for considerable overhead resulting in net savings of our scheme in the experiments. Our solution further provides full transparency and automation with the additional benefit of reusing existing resources. Executing continues after failures within the scheduled job, i.e., the application staging overhead is not incurred again in contrast to a restart. Our scheme offers additional potential for savings through incremental checkpointing and proactive diskless live migration, which we are currently working on.
Perspectives of Use of Diagnostic Mirrors with Transparent Protection Layer in Burning Plasma Experiments
Mukhin, Eugene E.; Razdobarin, Gennadiy T.; Semenov, Vladimir V.; Tolstyakov, Sergey Yu.; Kochergin, Mikhail M.; Kurskiev, Gleb S.; Podushnikova, Klara A. [Department of Plasma Physics, Nuclear Physics and Astrophysics, A.F. Ioffe Physico-Technical lnstitute, SPb, 194021 (Russian Federation); Andreev, Alexandr N.; Davydov, Denis V.; Rastegaeva, Marina G. [Division of Solid State Physics, A.F. Ioffe Physico-Technical Institute, SPb, 194021 (Russian Federation); Khimich, Yuriy P.; Gorshkov, Vladimir N.; Nikitin, Dmitriy B. [Research Institute of Optical Design, Federal Research Center Vavilov State Optical Institute, SPb, 199034 (Russian Federation); Litnovsky, Andrej M. [Institute fur Plasmaphysik, Forschungszentrum Julich, Partner in the Trilateral Euregio Cluster, Ass EURATOM-FZ Julich, D-52425 Julich (Germany)
We evaluate using of metal mirrors over-coated with transparent protection layer for the in-vessel diagnostic systems in reactor-grade fusion devices. Ideally, these should satisfy the contradictory demands of high reflectivity and small rate degradation when being bombarded by CX atoms. The serious threat to the performance of diagnostic mirrors is surface contamination with carbon-based material eroded from carbon tiles. Via coupling the protective layer to a bulk mirror we can mitigate the deposit infiuence on the reflectance spectra. The regards are given to survivability in plasma environment of protected coated metallic mirrors.
Laser frequency stabilization to highly excited state transitions using electromagnetically induced transparency in a cascade system
R. P. Abel; A. K. Mohapatra; M. G. Bason; J. D. Pritchard; K. J. Weatherill; U. Raitzsch; C. S. Adams
We demonstrate laser frequency stabilization to excited state transitions using cascade electromagnetically induced transparency (EIT). Using a room temperature Rb vapor cell as a reference, we stabilize a first diode laser to the D2 transition and a second laser to a transition from the intermediate state to a Rydberg state with principal quantum number n=19 - 70. A combined laser linewidth of 280 kHz over a 0.1 ms time period is achieved. This method may be applied generally to any cascade system and allows laser stabilization to an atomic reference in the absence of strong optical transitions.
Coherent optical detection of highly excited Rydberg states using electromagnetically induced transparency
A. K. Mohapatra; T. R. Jackson; C. S. Adams
We observe electromagnetically induced transparency (EIT) on the 5s to 5p transition in a room temperature rubidium vapour cell by coupling the 5p state to a Rydberg state (ns or nd with n=26 to 124). We demonstrate that the narrow line-width of the EIT resonance (2 MHz) allows precise measurement of the d state fine structure splitting, and together with the sensitivity of the Rydberg state to electric fields, we are able to detect transient electric fields produced by the dynamics of charges within the cell. Coherent coupling of Rydberg states via EIT could also be used for cross-phase modulation and photon entanglement.
Doping stability and opto-electronic performance of CVD graphene on transparent flexible substrates
Kang, Moon Hyo; Milne, William I.; Cole, Matthew T.
with modified graphene anode', Nature photonics, 2012, (6), 2, pp. 105-110 [7] Lee, J., Cole, M. T., Lai, J. C. S., et al.:'An Analysis of Electrode Patterns in Capacitive Touch Screen Panels', Display Technology, Journal of, 2014, (10), 5, pp. 362-366 [8... . C. H., Zhang, D., et al.:'Semitransparent organic solar cells with hybrid monolayer graphene/metal grid as top electrodes', Appl. Phys. Lett., 2013, (102), 11, p. 113303 [10] Park, H., Brown, P. R., Bulovic, V., et al.:'Graphene as transparent...
Amorphous semiconducting and conducting transparent metal oxide thin films and production thereof
Perkins, John (Boulder, CO); Van Hest, Marinus Franciscus Antonius Maria (Lakewood, CO); Ginley, David (Evergreen, CO); Taylor, Matthew (Golden, CO); Neuman, George A. (Holland, MI); Luten, Henry A. (Holland, MI); Forgette, Jeffrey A. (Hudsonville, MI); Anderson, John S. (Holland, MI)
Metal oxide thin films and production thereof are disclosed. An exemplary method of producing a metal oxide thin film may comprise introducing at least two metallic elements and oxygen into a process chamber to form a metal oxide. The method may also comprise depositing the metal oxide on a substrate in the process chamber. The method may also comprise simultaneously controlling a ratio of the at least two metallic elements and a stoichiometry of the oxygen during deposition. Exemplary amorphous metal oxide thin films produced according to the methods herein may exhibit highly transparent properties, highly conductive properties, and/or other opto-electronic properties.
Damp-Heat Induced Degradation of Transparent Conducting Oxides for Thin Film Solar Cells (Presentation)
Pern, J.; Noufi, R.; Li, X.; DeHart, C.; To, B.
The objectives are: (1) To achieve a high long-term performance reliability for the thin-film CIGS PV modules with more stable materials, device structure designs, and moisture-resistant encapsulation materials and schemes; (2) to evaluate the DH stability of various transparent conducting oxides (TCOs); (3) to identify the degradation mechanisms and quantify degradation rates; (4) to seek chemical and/or physical mitigation methods, and explore new materials. It's important to note that direct exposure to DH represents an extreme condition that a well-encapsulated thin film PV module may never experience.
Optomechanically-induced-transparency cooling of massive mechanical resonators to the quantum ground state
Liu, Yong-Chun; Luan, Xingsheng; Wong, Chee Wei
Ground state cooling of massive mechanical objects remains a difficult task restricted by the unresolved mechanical sidebands. We propose an optomechanically-induced-transparency cooling scheme to achieve ground state cooling of mechanical motion without the resolved sideband condition in a pure optomechanical system with two mechanical modes coupled to the same optical cavity mode. We show that ground state cooling is achievable for sideband resolution $\\omega_{m}/\\kappa$ as low as 0.003. This provides a new route for quantum manipulation of massive macroscopic devices and high-precision measurements.
A running coupling explanation of the surprising transparency of the QGP at LHC
Alessandro Buzzatti; Miklos Gyulassy
The CUJET Monte Carlo Jet Energy loss model is applied to predict the jet flavor, centrality and density dependence of the nuclear modification factor $R_{AA}$ at RHIC and LHC. Running coupling effects due to combined $x$, $k_\\perp$ and $q_\\perp$ evolution are included for the first time in the dynamical DGLV opacity expansion framework and are shown to provide a natural dynamical QCD tomographic solution to the surprising transparency of the quark gluon plasma produced at LHC as suggested by $p_\\perp>10$ GeV $R_{AA}$ data from ALICE, ATLAS, and CMS.
Pulse retrieval and soliton formation in a non-standard scheme for dynamic electromagnetically induced transparency
Amy Peng; Mattias Johnsson; Joseph J. Hope
We examine in detail an alternative method of retrieving the information written into an atomic ensemble of three-level atoms using electromagnetically induced transparency. We find that the behavior of the retrieved pulse is strongly influenced by the relative collective atom-light coupling strengths of the two relevant transitions. When the collective atom-light coupling strength for the retrieval beam is the stronger of the two transitions, regeneration of the stored pulse is possible. Otherwise, we show the retrieval process can lead to creation of soliton-like pulses.
Slow light of an amplitude modulated Gaussian pulse in electromagnetically induced transparency medium
Wenzhuo Tang; Bin Luo; Yu Liu; Hong Guo
The slow light effects of an amplitude modulated Gaussian (AMG) pulse in a cesium atomic vapor are presented. In a single-$\\Lambda$ type electromagnetically induced transparency (EIT) medium, more severe distortion is observed for an AMG pulse than a Gaussian one. Using Fourier spectrum analysis, we find that the distortion, as well as the loss, is dominantly caused by linear absorption than dispersion. Accordingly, a compensation method is proposed to reshape the slow light pulse based on the transmission spectrum. In addition, we find a novel way to obtain simultaneous slow and fast light.
A stable frequency comb directly referenced to rubidium electromagnetically induced transparency and two-photon transitions
Hou, Dong; Wu, Jiutao; Zhang, Shuangyou; Ren, Quansheng; Zhang, Zhigang; Zhao, Jianye, E-mail: email@example.com [Department of Electronics, Peking University, Beijing, 100871 (China)
We demonstrate an approach to create a stable erbium-fiber-based frequency comb at communication band by directly locking the combs to two rubidium atomic transitions resonances (electromagnetically induced transparency absorption and two-photon absorption), respectively. This approach directly transfers the precision and stability of the atomic transitions to the comb. With its distinguishing feature of compactness by removing the conventional octave-spanning spectrum and f-to-2f beating facilities and the ability to directly control the comb's frequency at the atomic transition frequency, this stable optical comb can be widely used in optical communication, frequency standard, and optical spectroscopy and microscopy.
331ZnO nanostructured transparent thin films by PLD Corresponding author: M. Suchea, e-mail: firstname.lastname@example.com
-to-band transitions [1], while it can be used as transparent electrode in solar cells and flat panel displays, grating
Short-pulse cross-phase modulation in an electromagnetically-induced-transparency medium
Feizpour, Amir; Steinberg, Aephraim M
Electromagnetically-induced transparency (EIT) has been proposed as a way to greatly enhance cross-phase modulation, with the possibility of leading to few-photon-level optical nonlinearities. This enhancement grows as the transparency window width, \\Delta_EIT, is narrowed. Decreasing \\Delta_EIT, however, increases the response time of the effect, suggesting that for pulses of a given duration, there could be a fundamental limit to the strength of the nonlinearity. We show that in the regimes of most practical interest - narrow EIT windows perturbed by short signal pulses- the enhancement offered by EIT is not only in the magnitude of the nonlinear phase shift but in fact also in its increased duration. That is, for the case of signal pulses much shorter (temporally) than the inverse EIT bandwidth, the narrow window serves to prolong the effect of the passing signal pulse, leading to an integrated phase shift that grows linearly with \\Delta_EIT even though the peak phase shift may saturate; the continued grow...
Participatory approach, acceptability and transparency of waste management LCAs: Case studies of Torino and Cuneo
Blengini, Gian Andrea, E-mail: email@example.com [DIATI - Department of Environment, Land and Infrastructures Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin (Italy); CNR-IGAG - Institute of Environmental Geology and Geo-Engineering, Corso Duca degli Abruzzi 24, 10129 Turin (Italy); Fantoni, Moris, E-mail: firstname.lastname@example.com [DIATI - Department of Environment, Land and Infrastructures Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin (Italy); Busto, Mirko, E-mail: firstname.lastname@example.com [European Commission - Joint Research Centre, Via Enrico Fermi 2749, I-21027 Ispra (Italy); Genon, Giuseppe, E-mail: firstname.lastname@example.com [DIATI - Department of Environment, Land and Infrastructures Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin (Italy); Zanetti, Maria Chiara, E-mail: email@example.com [DIATI - Department of Environment, Land and Infrastructures Engineering, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin (Italy)
Highlights: Black-Right-Pointing-Pointer Life Cycle Assessment is still not fully operational in waste management at local scale. Black-Right-Pointing-Pointer Credibility of WM LCAs is negatively affected by assumptions and lack of transparency. Black-Right-Pointing-Pointer Local technical-social-economic constraints are often not reflected by WM LCAs. Black-Right-Pointing-Pointer A participatory approach can increase acceptability and credibility of WM LCAs. Black-Right-Pointing-Pointer Results of a WM LCA can hardly ever be generalised, thus transparency is essential. - Abstract: The paper summarises the main results obtained from two extensive applications of Life Cycle Assessment (LCA) to the integrated municipal solid waste management systems of Torino and Cuneo Districts in northern Italy. Scenarios with substantial differences in terms of amount of waste, percentage of separate collection and options for the disposal of residual waste are used to discuss the credibility and acceptability of the LCA results, which are adversely affected by the large influence of methodological assumptions and the local socio-economic constraints. The use of site-specific data on full scale waste treatment facilities and the adoption of a participatory approach for the definition of the most sensible LCA assumptions are used to assist local public administrators and stakeholders showing them that LCA can be operational to waste management at local scale.
Apparatus and procedure to characterize the surface quality of conductors by measuring the rate of cathode emission as a function of surface electric field strength
Mestayer, Mac; Christo, Steve; Taylor, Mark
A device and method for characterizing quality of a conducting surface. The device including a gaseous ionizing chamber having centrally located inside the chamber a conducting sample to be tested to which a negative potential is applied, a plurality of anode or "sense" wires spaced regularly about the central test wire, a plurality of "field wires" at a negative potential are spaced regularly around the sense, and a plurality of "guard wires" at a positive potential are spaced regularly around the field wires in the chamber. The method utilizing the device to measure emission currents from the conductor.
Narrow energy band gap gallium arsenide nitride semi-conductors and an ion-cut-synthesis method for producing the same
Weng, Xiaojun; Goldman, Rachel S.
A method for forming a semi-conductor material is provided that comprises forming a donor substrate constructed of GaAs, providing a receiver substrate, implanting nitrogen into the donor substrate to form an implanted layer comprising GaAs and nitrogen. The implanted layer is bonded to the receiver substrate and annealed to form GaAsN and nitrogen micro-blisters in the implanted layer. The micro-blisters allow the implanted layer to be cleaved from the donor substrate.
Transparency of 0.2% GdCl3 Doped Water in a Stainless Steel Test Environment
W. Coleman; A. Bernstein; S. Dazeley; R. Svoboda
The possibility of neutron and neutrino detection using water Cerenkov detectors doped with gadolinium holds the promise of constructing very large high-efficiency detectors with wide-ranging application in basic science and national security. This study addressed a major concern regarding the feasibility of such detectors: the transparency of the doped water to the ultraviolet Cerenkov light. We report on experiments conducted using a 19-meter water transparency measuring instrument and associated materials test tank. Sensitive measurements of the transparency of water doped with 0.2% GdCl3 at 337nm, 400nm and 420nm were made using this instrument. These measurements indicate that GdCl3 is not an appropriate dopant in stainless steel constructed water Cerenkov detectors.
Architecture for coated conductors
Foltyn, Stephen R.; Arendt, Paul N.; Wang, Haiyan; Stan, Liliana
Articles are provided including a base substrate having a layer of an oriented cubic oxide material with a rock-salt-like structure layer thereon, and, a layer of epitaxial titanium nitride upon the layer of an oriented cubic oxide material having a rock-salt-like structure. Such articles can further include thin films of high temperature superconductive oxides such as YBCO upon the layer of epitaxial titanium nitride or upon a intermediate buffer layer upon the layer of epitaxial titanium nitride.
335Nanostructured ZnO and ZAO transparent thin films by sputteringsurface characterization Corresponding author: M. Suchea, e-mail: email@example.com
as transparent electrode in solar cells and flat panel displays as well as for the fabrication of gratings Abstract. Zinc oxide (ZnO) and aluminum zinc oxide (ZAO) transparent thin films with different thickness Zinc oxide is one of the earliest discovered metal oxide gas sensing materials. It is an n-type semi
Transparent Conducting Electrodes based on 1D and 2D Ag Nanogratings for Organic Photovoltaics
Zeng, Beibei; Bartoli, Filbert J
The optical and electrical properties of optically-thin one-dimensional (1D) Ag nanogratings and two-dimensional (2D) Ag nanogrids are studied, and their use as transparent electrodes in organic photovoltaics are explored. A large broadband and polarization-insensitive optical absorption enhancement in the organic light-harvesting layers is theoretically and numerically demonstrated using either single-layer 2D Ag nanogrids or two perpendicular 1D Ag nanogratings, and is attributed to the excitation of surface plasmon resonances and plasmonic cavity modes. Total photon absorption enhancements of 150% and 200% are achieved for the optimized single-layer 2D Ag nanogrids and double (top and bottom) perpendicular 1D Ag nanogratings, respectively.
Damage mechanisms in thin film solar cells during sputtering deposition of transparent conductive coatings
Fan Qihua; Liao Xianbo [Department of Physics and Astronomy, University of Toledo, 2801 West Bancroft Street, Toledo, Ohio 43606 (United States); Deng, Michael [Xunlight Corporation, 3145 Nebraska Avenue, Toledo, Ohio 43607 (United States); Deng Xunming [Department of Physics and Astronomy, University of Toledo, 2801 West Bancroft Street, Toledo, Ohio 43606 (United States); Xunlight Corporation, 3145 Nebraska Avenue, Toledo, Ohio 43607 (United States)
Amorphous silicon (a-Si) based thin film solar cell grown on flexible stainless steel substrate is one of the most promising energy conversion devices in the future. This type of solar cell uses a transparent conductive oxide (TCO) film as top electrode. It has been a widely accepted opinion that the radio frequency sputtering deposition of the TCO film produces a higher yield than direct current sputtering, and the reason is not clear. Here we show that the damage to the solar cell during the sputtering process is caused by a reverse bias applied to the n-i-p junction. This reverse bias is related to the characteristics of plasma discharge. The mechanism we reveal may significantly affect the solar cell process.
System of and method for transparent management of data objects in containers across distributed heterogenous resources
Moore, Reagan W. (San Diego, CA); Rajasekar, Arcot (Del Mar, CA); Wan, Michael Y. (San Diego, CA)
A system of and method for maintaining data objects in containers across a network of distributed heterogeneous resources in a manner which is transparent to a client. A client request pertaining to containers is resolved by querying meta data for the container, processing the request through one or more copies of the container maintained on the system, updating the meta data for the container to reflect any changes made to the container as a result processing the request, and, if a copy of the container has changed, changing the status of the copy to indicate dirty status or synchronizing the copy to one or more other copies that may be present on the system.
System of and method for transparent management of data objects in containers across distributed heterogenous resources
Moore, Reagan W.; Rajasekar, Arcot; Wan, Michael Y.
A system of and method for maintaining data objects in containers across a network of distributed heterogeneous resources in a manner which is transparent to a client. A client request pertaining to containers is resolved by querying meta data for the container, processing the request through one or more copies of the container maintained on the system, updating the meta data for the container to reflect any changes made to the container as a result processing the request, and, if a copy of the container has changed, changing the status of the copy to indicate dirty status or synchronizing the copy to one or more other copies that may be present on the system.
System of and method for transparent management of data objects in containers across distributed heterogenous resources
Moore, Reagan W. (San Diego, CA); Rajasekar, Arcot (Del Mar, CA); Wan, Michael Y. (San Diego, CA)
A system of and method for maintaining data objects in containers across a network of distributed heterogeneous resources in a manner which is transparent to a client. A client request pertaining to containers is resolved by querying meta data for the container, processing the request through one or more copies of the container maintained on the system, updating the meta data for the container to reflect any changes made to the container as a result processing the re quest, and, if a copy of the container has changed, changing the status of the copy to indicate dirty status or synchronizing the copy to one or more other copies that may be present on the system.
Femtosecond laser ablation of dielectric materials in the optical breakdown regime: Expansion of a transparent shell
Garcia-Lechuga, M.; Siegel, J., E-mail: firstname.lastname@example.com; Hernandez-Rueda, J.; Solis, J. [Laser Processing Group, Instituto de Optica, Serrano 121, 28006 Madrid (Spain)
Phase transition pathways of matter upon ablation with ultrashort laser pulses have been considered to be understood long-since for metals and semiconductors. We provide evidence that also certain dielectrics follow the same pathway, even at high pulse energies triggering optical breakdown. Employing femtosecond microscopy, we observe a characteristic ring pattern within the ablating region that dynamically changes for increasing time delays between pump and probe pulse. These transient Newton rings are related to optical interference of the probe beam reflected at the front surface of the ablating layer with the reflection at the interface of the non-ablating substrate. Analysis of the ring structure shows that the ablation mechanism is initiated by a rarefaction wave leading within a few tens of picoseconds to the formation of a transparent thin shell of reduced density and refractive index, featuring optically sharp interfaces. The shell expands and eventually detaches from the solid material at delays of the order of 100 ps.
Data Mining-Aided Crystal Engineering for the Design of Transparent Conducting Oxides: Preprint
Suh, C.; Kim, K.; Berry, J. J.; Lee, J.; Jones, W. B.
The purpose of this paper is to accelerate the pace of material discovery processes by systematically visualizing the huge search space that conventionally needs to be explored. To this end, we demonstrate not only the use of empirical- or crystal chemistry-based physical intuition for decision-making, but also to utilize knowledge-based data mining methodologies in the context of finding p-type delafossite transparent conducting oxides (TCOs). We report on examples using high-dimensional visualizations such as radial visualization combined with machine learning algorithms such as k-nearest neighbor algorithm (k-NN) to better define and visualize the search space (i.e. structure maps) of functional materials design. The vital role of search space generated from these approaches is discussed in the context of crystal chemistry of delafossite crystal structure.
Atomic Physics Effects on Convergent, Child-Langmuir Ion Flow between Nearly Transparent Electrodes
Santarius, John F. [University of Wisconsin-Madison] [University of Wisconsin-Madison; Emmert, Gilbert A. [University of Wisconsin-Madison] [University of Wisconsin-Madison
Research during this project at the University of Wisconsin Fusion Technology Institute (UW FTI) on ion and neutral flow through an arbitrary, monotonic potential difference created by nearly transparent electrodes accomplished the following: (1) developed and implemented an integral equation approach for atomic physics effects in helium plasmas; (2) extended the analysis to coupled integral equations that treat atomic and molecular deuterium ions and neutrals; (3) implemented the key deuterium and helium atomic and molecular cross sections; (4) added negative ion production and related cross sections; and (5) benchmarked the code against experimental results. The analysis and codes treat the species D0, D20, D+, D2+, D3+, D and, separately at present, He0 and He+. Extensions enhanced the analysis and related computer codes to include He++ ions plus planar and cylindrical geometries.
Another Look at Confidence Intervals: Proposal for a More Relevant and Transparent Approach
Steven D. Biller; Scott M. Oser
The behaviors of various confidence/credible interval constructions are explored, particularly in the region of low statistics where methods diverge most. We highlight a number of challenges, such as the treatment of nuisance parameters, and common misconceptions associated with such constructions. An informal survey of the literature suggests that confidence intervals are not always defined in relevant ways and are too often misinterpreted and/or misapplied. This can lead to seemingly paradoxical behaviours and flawed comparisons regarding the relevance of experimental results. We therefore conclude that there is a need for a more pragmatic strategy which recognizes that, while it is critical to objectively convey the information content of the data, there is also a strong desire to derive bounds on models and a natural instinct to interpret things this way. Accordingly, we attempt to put aside philosophical biases in favor of a practical view to propose a more transparent and self-consistent approach that better addresses these issues.
Electromagnetially-induced-transparency-like ground-state cooling in a double-cavity optomechanical system
Yujie Guo; Kai Li; Wenjie Nie; Yong Li
We propose to cool a mechanical resonator close to its ground state via an electromagnetically-induced-transparency- (EIT-) like cooling mechanism in a double-cavity optomechanical system, where an additional cavity couples to the original one in the standard optomechanical system. By choosing optimal parameters such that the cooling process of the mechanical resonator corresponds to the maximum value of the optical fluctuation spectrum and the heating process to the minimum one, the mechanical resonator can be cooled with the final mean phonon number less than that at the absence of the additional cavity. And we show the mechanical resonator may be cooled close to its ground state via such an EIT-like cooling mechanism even when the original resolved sideband condition is not fulfilled at the absence of the additional cavity.
Nanosecond-laser plasma-assisted ultradeep microdrilling of optically opaque and transparent solids
Paul, Stanley; Kudryashov, Sergey I.; Lyon, Kevin; Allen, Susan D. [Department of Chemistry and Physics, Arkansas State University, State University, Arkansas 72467-0419 (United States)
A mechanism of ultradeep (up to tens of microns per pulse, submillimeter total hole depths) plasma-assisted ablative drilling of optically opaque and transparent materials by high-power nanosecond lasers has been proposed and verified experimentally using optical transmission and contact photoacoustic techniques to measure average drilling rates per laser shot versus laser intensity at constant focusing conditions. The plots of average drilling rates versus laser intensity exhibit slopes which are in good agreement with those predicted by the proposed model and also with other experimental studies. The proposed ultradeep drilling mechanism consists of a number of stages, including ultradeep 'nonthermal' energy delivery into bulk solids by the short-wavelength radiation of the hot ablative plasma, bulk heating and melting, accompanied by subsurface boiling in the melt pool, and resulting melt expulsion from the target.
Investigation of nanostructured transparent conductive films grown by rotational-sequential-sputtering
Lu, Jong-Hong, E-mail: email@example.com; Chen, Bo-Ying; Wang, Chih-Hsuan [Department of Materials Engineering, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist. New Taipei City 24301, Taiwan and Center for Thin Film Technologies and Applications, Ming Chi University of Technology, 84 Gungjuan Rd., Taishan Dist. New Taipei City 24301, Taiwan (China)
This study fabricates three types of nanostructured conductive transparent films using a rotational-sequential-sputtering method. These films include (1) TiO{sub 2}/indium-tin oxide (ITO) and SiO{sub x}/ITO nanomultilayer films, the optical refractive indices of which can be manipulated in the range of 2.421.63 at a wavelength of 550?nm with a controlled resistivity range of 1?æ?10{sup ?3} to 2?æ?10{sup ?4} ?ñcm. (2) Multilayer ITO films are deposited on polyethylene terephthalate substrates, providing good flexibility and resistivity as low as 5?æ?10{sup ?4} ?ñcm. Finally, (3) ultrathin ITO films ranging from subnanometer to a few nanometers in thickness enable exploration of ITO film growth and thermal stability. X-ray reflection characterization provides a rapid, non-destructive method to measure the single-layer thicknesses of the nanomultilayer films and ultrathin ITO films at subnanoscale resolution.
Dynamic daylight control system implementing thin cast arrays of polydimethylsiloxane-based millimeter-scale transparent louvers
Aizenberg, Joanna
Dynamic daylight control system implementing thin cast arrays of polydimethylsiloxane: Daylight control system Dynamic window system Energy-efficiency Transparent louvers a b s t r a c in standard office buildings. The development of daylight control systems that maximize the penetration
Experimental determination of transparency current density and estimation of the threshold current of semiconductor quantum well lasers
Chen, T.R.; Eng, L.E.; Zhuang, Y.H.; Yariv, A. (California Institute of Technology, Pasadena, California 91125 (US))
An experimental method for determining the transparency current density of semiconductor quantum well lasers is demonstrated in a strained-layer InGaAs/GaAs single quantum well laser system. The experimental results are then used as a practical guide to the study of ultralow threshold lasers. A threshold current as low as 0.75 mA is observed.
Transparent Poly(methyl methacrylate)/Single-Walled Carbon Nanotube (PMMA/SWNT) Composite Films with Increased
Harmon, Julie P.
Transparent Poly(methyl methacrylate)/Single-Walled Carbon Nanotube (PMMA/SWNT) Composite Films to conventional polymer composites due to the stronger interac- tions between polymer and filler phases. Carbon and fast-growing class of materials with nanosized filler domains finely dispersed in a polymer matrix.[1
Tuning the properties of complex transparent conducting oxides: Role of crystal symmetry, chemical composition, and carrier generation
Medvedeva, Julia E.
Tuning the properties of complex transparent conducting oxides: Role of crystal symmetry, chemical; revised manuscript received 24 February 2010; published 17 March 2010 The electronic properties of singleO3, , and -Ga2O3, rock salt and wurtzite ZnO, and layered InGaZnO4 reveals the role of the following
Electrical and Optical Properties of Transparent Conducting Homologous Compounds in the IndiumGalliumZinc Oxide System
Poeppelmeier, Kenneth R.
, smart windows, and solar cells. Tin-doped indium oxide (ITO) is the commercial TCO of choice. ITO thin TRANSPARENT conducting oxides (TCOs) are used in a wide variety of applications, such as flat-panel displays, and lower cost are desired for use in demanding ap- plications such as next-generation flat-panel displays
Yellow-green strained-InGaP quantum-well epitaxial-transparent-substrate light emitting diodes
Yellow-green strained-InGaP quantum-well epitaxial-transparent-substrate light emitting diodes L March 2004 We present a strained-InGaP quantum-well light emitting diode LED operating in the green that InGaP alloys in this composition range are not lattice-matched to any traditional substrate material
Co-sputtered Aluminum Doped Zinc Oxide Thin Film as Transparent Anode for Organic Light-emitting Diodes
Co-sputtered Aluminum Doped Zinc Oxide Thin Film as Transparent Anode for Organic Light and Technology, Clear Water Bay, Kowloon, Hong Kong, China ABSTRACT Aluminum doped zinc oxide (AZO that MTDATA matches better with AZO than CuPc, which served as hole injection layer. Keywords: Aluminum doped
The Superconductors that Magnets Really Want: What Stands in the Way? (Superconductors for Accelerator Use: What Next and How Close is the Ideal Conductor?)
Larbalestier, David (National High Magnetic Field Laboratory and Florida State University) [National High Magnetic Field Laboratory and Florida State University
There are over 5000 superconducting materials but only about 5 have ever been useful for applications in magnets, while HEP, which has been so vital for the development of superconducting magnet technology has made virtually every magnet out of just one, the simple bcc alloy Nb-Ti with Tc of 9 K and upper critical field {approx} 14T (at 2K). Significant demonstrations of the capability of the brittle intermetallic Nb3Sn have shown that fields of more than 15 T can be generated in dipole form. But Nb-Ti and Nb3Sn are staid, conventional superconductors, far from the cutting edge of superconducting science research where cuprates like YBa2Cu3O7-x and Bi2Sr2CaCu2Ox remain at the scientific forefront and in 2008 were joined by the recently discovered Fe-As pnictide superconductors. What could it mean to have materials for magnets with 10 times the Tc of Nb-Ti (90-120 K) and 3 or more times the critical field (100-240 T)? One enormous barrier is that higher Tc so far always means more complexity and a more localized superconducting interaction which is sensitive to local loss of superconductivity. The issue that has made the cuprate high temperature superconductors so hard to apply is that grain boundaries which form a 3D network in any practical wire form, easily acquire degraded superconducting properties. But conductors can now be made with extreme texture so that grain boundaries are minimized. Moreover almost practical conductors of Bi2Sr2CaCu2Ox and YBa2Cu3O7-x are now are in production and in late 2008 we were, at the Magnet Lab, able to make small solenoids operating at high current density in fields of 32 and almost 34 T respectively. Within the HEP community, there is enthusiasm to embrace HTS conductors for new very high field machines that could, like the Muon Collider, use fields of 30-50 T. In my talk I would like to explore the underlying science controlling such potential applications.
Why Lead Methylammonium tri-IODIDE perovskite-based solar cells requires a mesoporous electron transporting scaffold (but not necessarily a hole conductor)
Edri, Eran; Henning, Alex; Mukhopadhyay, Sabyasachi; Gartsman, Konstantin; Rosenwaks, Yossi; Hodes, Gary; Cahen, David
CH3NH3PbI3-based solar cells were characterized with electron beam-induced current (EBIC), and compared to CH3NH3PbI3-xClx ones. A spatial map of charge separation efficiency in working cells shows p-i-n structures for both thin film cells. Effective diffusion lengths, LD, (from EBIC profile) show that holes are extracted significantly more efficiently than electrons in CH3NH3PbI3, explaining why CH3NH3PbI3-based cells require mesoporous electron conductors, while CH3NH3PbI3-xClx ones, where LD values are comparable for both charge types, do not.
Structural stability of transparent conducting films assembled from length purified single-wall carbon nanotubes
J. M. Harris; G. R. S. Iyer; D. O. Simien; J. A. Fagan; J. Y. Huh; J. Y. Chung; S. D. Hudson; J. Obrzut; J. F. Douglas; C. M. Stafford; E. K. Hobbie
Single-wall carbon nanotube (SWCNT) films show significant promise for transparent electronics applications that demand mechanical flexibility, but durability remains an outstanding issue. In this work, thin membranes of length purified single-wall carbon nanotubes (SWCNTs) are uniaxially and isotropically compressed by depositing them on prestrained polymer substrates. Upon release of the strain, the topography, microstructure, and conductivity of the films are characterized using a combination of optical/fluorescence microscopy, light scattering, force microscopy, electron microscopy, and impedance spectroscopy. Above a critical surface mass density, films assembled from nanotubes of well-defined length exhibit a strongly nonlinear mechanical response. The measured strain dependence reveals a dramatic softening that occurs through an alignment of the SWCNTs normal to the direction of prestrain, which at small strains is also apparent as an anisotropic increase in sheet resistance along the same direction. At higher strains, the membrane conductivities increase due to a compression-induced restoration of conductive pathways. Our measurements reveal the fundamental mode of elasto-plastic deformation in these films and suggest how it might be suppressed.
Towards more transparent and reproducible omics studies through a common metadata checklist and data publications
Kolker, Eugene; Ozdemir, Vural; Martens , Lennart; Hancock, William S.; Anderson, Gordon A.; Anderson, Nathaniel; Aynacioglu, Sukru; Baranova, Ancha; Campagna, Shawn R.; Chen, Rui; Choiniere, John; Dearth, Stephen P.; Feng, Wu-Chun; Ferguson, Lynnette; Fox, Geoffrey; Frishman, Dmitrij; Grossman, Robert; Heath, Allison; Higdon, Roger; Hutz, Mara; Janko, Imre; Jiang, Lihua; Joshi, Sanjay; Kel, Alexander; Kemnitz, Joseph W.; Kohane, Isaac; Kolker, Natali; Lancet, Doron; Lee, Elaine; Li, Weizhong; Lisitsa, Andrey; Llerena, Adrian; MacNealy-Koch, Courtney; Marhsall, Jean-Claude; Masuzzo, Paolo; May, Amanda; Mias, George; Monroe, Matthew E.; Montague, Elizabeth; Monney, Sean; Nesvizhskii, Alexey; Noronha, Santosh; Omenn, Gilbert; Rajasimha, Harsha; Ramamoorthy, Preveen; Sheehan, Jerry; Smarr, Larry; Smith, Charles V.; Smith, Todd; Snyder, Michael; Rapole, Srikanth; Srivastava, Sanjeeva; Stanberry, Larissa; Stewart, Elizabeth; Toppo, Stefano; Uetz, Peter; Verheggen, Kenneth; Voy, Brynn H.; Warnich, Louise; Wilhelm, Steven W.; Yandl, Gregory
Biological processes are fundamentally driven by complex interactions between biomolecules. Integrated high-throughput omics studies enable multifaceted views of cells, organisms, or their communities. With the advent of new post-genomics technologies omics studies are becoming increasingly prevalent yet the full impact of these studies can only be realized through data harmonization, sharing, meta-analysis, and integrated research,. These three essential steps require consistent generation, capture, and distribution of the metadata. To ensure transparency, facilitate data harmonization, and maximize reproducibility and usability of life sciences studies, we propose a simple common omics metadata checklist. The proposed checklist is built on the rich ontologies and standards already in use by the life sciences community. The checklist will serve as a common denominator to guide experimental design, capture important parameters, and be used as a standard format for stand-alone data publications. This omics metadata checklist and data publications will create efficient linkages between omics data and knowledge-based life sciences innovation and importantly, allow for appropriate attribution to data generators and infrastructure science builders in the post-genomics era. We ask that the life sciences community test the proposed omics metadata checklist and data publications and provide feedback for their use and improvement.
Transparent Conducting ZnO Thin Films Doped with Al and Mo
Duenow, J.; Gessert, T.; Wood, D.; Young, D.; Coutts, T.
Transparent conducting oxide (TCO) thin films are a vital part of photovoltaic cells, flat-panel displays, and electrochromic windows. ZnO-based TCOs, due to the relative abundance of Zn, may reduce production costs compared to those of the prevalent TCO In2O3:Sn (ITO). Undoped ZnO, ZnO:Al (0.5, 1, and 2 wt.% Al2O3), and ZnO:Mo (2 wt.%) films were deposited by RF magnetron sputtering. Controlled incorporation of H2 in the Ar sputtering ambient increased mobility of undoped ZnO by a factor of ~20 to 48 cm2V-1s-1. H2 also appears to catalyze ionization of dopants. This enabled lightly doped ZnO:Al to provide comparable conductivity to the standard 2 wt.%-doped ZnO:Al while demonstrating reduced infrared absorption. Mo was found to be an n-type dopant of ZnO, though material properties did not match those of ZnO:Al. Scattering mechanisms were investigated using temperature-dependent Hall measurements and the method of four coefficients. This abstract is subject to government rights.
Linear and nonlinear light propagations in a Doppler-broadened medium via electromagnetically induced transparency
Li Liang; Huang Guoxiang [Department of Physics and Institute of Theoretical Physics, East China Normal University, Shanghai 200062 (China); State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China and Institute of Nonlinear Physics, Zhejiang Normal University, Zhejiang 321004 (China)
We present a systematic theoretical study to deal with linear and nonlinear light propagations in a Doppler-broadened three-level {Lambda} system via electromagnetically induced transparency (EIT), with incoherent population exchange between two lower energy levels taken into account. Through a careful analysis of base state and linear excitation, we show that the EIT condition of the system is given by |{Omega}{sub c}|{sup 2{gamma}}{sub 31}>>2{gamma}{sub 21{Delta}{omega}D}{sup 2}, where {Omega}{sub c} is half the Rabi frequency of the control field, {Delta}{omega}{sub D} is the Doppler width, and {gamma}{sub jl} is the decay rate of the coherence between states |j> and |l>. Under this condition, the effect of incoherent population exchange is insignificant, while dephasing dominates the decoherence of the system. This condition also ensures the validity of the weak nonlinear perturbation theory used in this work for solving the Maxwell-Bloch equations with inhomogeneous broadening. We then investigate the nonlinear propagation of the probe field and show that it is possible to form temporal optical solitons in the Doppler-broadened medium. Such solitons have ultraslow propagating velocity and can be generated in very low light power. The possibility of realizing (1+1)-dimensional and (2+1)-dimensional spatial optical solitons in the adiabatic regime of the system is also discussed.
A narrow window of Rabi frequency for competition between electromagnetically induced transparency and Raman absorption
Chang, Ray-Yuan; Fang, Wei-Chia; Lee, Ming-Tsung; He, Zong-Syun; Ke, Bai-Cian [Department of Physics, National Cheng-Kung University, Tainan 70101, Taiwan (China); Lee, Yi-Chi [Institute of Electro-Optical Science and Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China); Tsai, Chin-Chun [Department of Physics, National Cheng-Kung University, Tainan 70101, Taiwan (China); Institute of Electro-Optical Science and Engineering, National Cheng-Kung University, Tainan 70101, Taiwan (China)
This investigation clarifies the transition phenomenon between the electromagnetically induced transparency (EIT) and Raman absorption in a ladder-type system of Doppler-broadened cesium vapor. A competition window of this transition was found to be as narrow as 2 MHz defined by the probe Rabi frequency. For a weak probe, the spectrum of EIT associated with quantum interference suggests that the effect of the Doppler velocity on the spectrum is negligible. When the Rabi frequency of the probe becomes comparable with the effective decay rate, an electromagnetically induced absorption (EIA) dip emerges at the center of the power broadened EIT peak. While the Rabi frequency of the probe exceeds the effective decay rate, decoherence that is generated by the intensified probe field occurs and Raman absorption dominates the interaction process, yielding a pure absorption spectrum; the Doppler velocity plays an important role in the interaction. A theory that is based on density matrix simulation, with or without the Doppler effect, can qualitatively fit the experimental data. In this work, the coherence of atom-photon interactions is created or destroyed using the probe Rabi frequency as a decoherence source.
Ag-Pd-Cu alloy inserted transparent indium tin oxide electrodes for organic solar cells
Kim, Hyo-Joong; Seo, Ki-Won; Kim, Han-Ki, E-mail: email@example.com [Department of Advanced Materials Engineering for Information and Electronics, Kyung-Hee University, 1 Seocheon-dong, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of); Noh, Yong-Jin; Na, Seok-In [Graduate School of Flexible and Printable Electronics, Chonbuk National University, 664-14, Deokjin-dong, Jeonju-si, Jeollabuk-do 561-756 (Korea, Republic of)
The authors report on the characteristics of Ag-Pd-Cu (APC) alloy-inserted indium tin oxide (ITO) films sputtered on a glass substrate at room temperature for application as transparent anodes in organic solar cells (OSCs). The effect of the APC interlayer thickness on the electrical, optical, structural, and morphological properties of the ITO/APC/ITO multilayer were investigated and compared to those of ITO/Ag/ITO multilayer electrodes. At the optimized APC thickness of 8?nm, the ITO/APC/ITO multilayer exhibited a resistivity of 8.55?æ?10{sup ?5} ? cm, an optical transmittance of 82.63%, and a figure-of-merit value of 13.54?æ?10{sup ?3} ?{sup ?1}, comparable to those of the ITO/Ag/ITO multilayer. Unlike the ITO/Ag/ITO multilayer, agglomeration of the metal interlayer was effectively relieved with APC interlayer due to existence of Pd and Cu elements in the thin region of the APC interlayer. The OSCs fabricated on the ITO/APC/ITO multilayer showed higher power conversion efficiency than that of OSCs prepared on the ITO/Ag/ITO multilayer below 10?nm due to the flatness of the APC layer. The improved performance of the OSCs with ITO/APC/ITO multilayer electrodes indicates that the APC alloy interlayer prevents the agglomeration of the Ag-based metal interlayer and can decrease the thickness of the metal interlayer in the oxide-metal-oxide multilayer of high-performance OSCs.
Investigation of Some Transparent Metal Oxides as Damp Heat Protective Coating for CIGS Solar Cells: Preprint
Pern, F. J.; Yan, F.; Zaaunbrecher, B.; To, B.; Perkins, J.; Noufi, R.
We investigated the protective effectiveness of some transparent metal oxides (TMO) on CIGS solar cell coupons against damp heat (DH) exposure at 85oC and 85% relative humidity (RH). Sputter-deposited bilayer ZnO (BZO) with up to 0.5-um Al-doped ZnO (AZO) layer and 0.2-um bilayer InZnO were used as 'inherent' part of device structure on CdS/CIGS/Mo/SLG. Sputter-deposited 0.2-um ZnSnO and atomic layer deposited (ALD) 0.1-um Al2O3 were used as overcoat on typical BZO/CdS/CIGS/Mo/SLG solar cells. The results were all negative -- all TMO-coated CIGS cells exhibited substantial degradation in DH. Combining the optical photographs, PL and EL imaging, SEM surface micro-morphology, coupled with XRD, I-V and QE measurements, the causes of the device degradations are attributed to hydrolytic corrosion, flaking, micro-cracking, and delamination induced by the DH moisture. Mechanical stress and decrease in crystallinity (grain size effect) could be additional degrading factors for thicker AZO grown on CdS/CIGS.
See-through amorphous silicon solar cells with selectively transparent and conducting photonic crystal back reflectors for building integrated photovoltaics
Yang, Yang [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Room GB254B, Toronto, Ontario M5S 3G4 (Canada)] [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Room GB254B, Toronto, Ontario M5S 3G4 (Canada); OBrien, Paul G. [Department of Materials Science and Engineering, University of Toronto, 184 College Street, Room 140, Toronto, Ontario M5S 3E4 (Canada) [Department of Materials Science and Engineering, University of Toronto, 184 College Street, Room 140, Toronto, Ontario M5S 3E4 (Canada); Materials Chemistry Research Group, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 (Canada); Ozin, Geoffrey A., E-mail: email@example.com, E-mail: firstname.lastname@example.com [Materials Chemistry Research Group, Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, Ontario M5S 3H6 (Canada); Kherani, Nazir P., E-mail: email@example.com, E-mail: firstname.lastname@example.com [The Edward S. Rogers Sr. Department of Electrical and Computer Engineering, University of Toronto, 10 King's College Road, Room GB254B, Toronto, Ontario M5S 3G4 (Canada); Department of Materials Science and Engineering, University of Toronto, 184 College Street, Room 140, Toronto, Ontario M5S 3E4 (Canada)
Thin semi-transparent hydrogenated amorphous silicon (a-Si:H) solar cells with selectively transparent and conducting photonic crystal (STCPC) back-reflectors are demonstrated. Short circuit current density of a 135?nm thick a-Si:H cell with a given STCPC back-reflector is enhanced by as much as 23% in comparison to a reference cell with an ITO film functioning as its rear contact. Concurrently, solar irradiance of 295?W/m{sup 2} and illuminance of 3480 lux are transmitted through the cell with a given STCPC back reflector under AM1.5 Global tilt illumination, indicating its utility as a source of space heating and lighting, respectively, in building integrated photovoltaic applications.
Application of Single Wall Carbon Nanotubes as Transparent Electrodes in Cu(In,Ga)Se2-Based Solar Cells: Preprint
Contreras, M.; Barnes, T.; van de Lagemaat, J.; Rumbles, G.; Coutts, T. J.; Weeks, C.; Glatkowski, P.; Levitsky, I.; Peltola, J.
We present a new thin-film solar cell structure in which the traditional transparent conductive oxide electrode (ZnO) is replaced by a transparent conductive coating consisting of a network of bundled single-wall carbon nanotubes. Optical transmission properties of these coatings are presented in relation to their electrical properties (sheet resistance), along with preliminary solar cell results from devices made using CuIn1-xGaxSe2 thin-film absorber materials. Achieving an energy conversion efficiency of >12% and a quantum efficiency of {approx}80% demonstrate the feasibility of the concept. A discussion of the device structures will be presented considering the physical properties of the new electrodes comparing current-voltage results from the new solar cell structure and those from standard ZnO/CdS/Cu(In,Ga)Se2/Mo solar cells.
Infrared-optical spectroscopy of transparent conducting perovskite (La,Ba)SnO{sub 3} thin films
Seo, Dongmin; Yu, Kwangnam; Jun Chang, Young; Choi, E. J., E-mail: email@example.com [Department of Physics, University of Seoul, Seoul 130-743 (Korea, Republic of); Sohn, Egon; Hoon Kim, Kee [Center for Novel States of Complex Materials Research, Department of Physics and Astronomy, Seoul National University, Seoul 151-747 (Korea, Republic of)
We have performed optical transmission, reflection, spectroscopic ellipsometry, and Hall effect measurements on the electron-doped La{sub x}Ba{sub 1x}SnO{sub 3} (x?=?0.04) transparent thin films. From the infrared Drude response and plasma frequency analysis we determine the effective mass of the conducting electron m*?=?0.35m{sub 0}. In the visible-UV region the optical band gap shifts to high energy in (La,Ba)SnO{sub 3} by 0.18?eV compared with undoped BaSnO{sub 3} which, in the context of the Burstein-Moss analysis, is consistent with the infrared-m*. m* of BaSnO{sub 3} is compared with other existing transparent conducting oxides (TCO), and implication on search for high-mobility TCO compounds is discussed.
The longitudinal asymmetry of the (e,e'p) missing momentum distribution as a signal of color transparency
Benhar, O; Nikolaev, N N; Speth, J; Usmani, A A; Zakharov, B G
We use multiple scattering theory to evaluate the Q^{2} dependence of the forward-backward asymmetry, A_{z}, of the missing momentum distribution in quasielstic A(e,e'p) scattering, which is expected to be affected by color transparency. The novel features of our analysis are a consistent treatment of the structure of the ejectile state formed after absorption of the virtual photon by the struck proton and a careful evaluation of the background asymmetry induced by the nonvanishing real part of the proton-nucleon scattering amplitude. We find that the absolute magnitude of A_{z} is dominated by this background at the Q^{2}'s attainable at the Continuous Electron Beam Accelerator Facility. However, the Q^{2} dependence of the asymmetry is sensitive to the onset of color transparency, whose observation in high statistics experiments appears to be feasible, particularly using light targets such as ^{12}C or ^{16}O.
The longitudinal asymmetry of the $(e,e'p)$ missing momentum distribution as a signal of color transparency
O. Benhar; S. Fantoni; N. N. Nikolaev; J. Speth; A. A. Usmani; B. G. Zakharov
We use multiple scattering theory to evaluate the $Q^{2}$ dependence of the forward-backward asymmetry, $A_{z}$, of the missing momentum distribution in quasielstic $A(e,e'p)$ scattering, which is expected to be affected by color transparency. The novel features of our analysis are a consistent treatment of the structure of the ejectile state formed after absorption of the virtual photon by the struck proton and a careful evaluation of the background asymmetry induced by the nonvanishing real part of the proton-nucleon scattering amplitude. We find that the absolute magnitude of $A_{z}$ is dominated by this background at the $Q^{2}$'s attainable at the Continuous Electron Beam Accelerator Facility. However, the $Q^{2}$ dependence of the asymmetry is sensitive to the onset of color transparency, whose observation in high statistics experiments appears to be feasible, particularly using light targets such as $^{12}C$ or $^{16}O$.
Self-Induced Transparency and Electromagnetic Pulse Compression in a Plasma or an Electron Beam under Cyclotron Resonance Conditions
Ginzburg, N. S.; Zotova, I. V.; Sergeev, A. S. [Institute of Applied Physics, RAS, GSP-120 N. Novgorod (Russian Federation)
Based on analogy to the well-known process of the self-induced transparency of an optical pulse propagating through a passive two-level medium we describe similar effects for a microwave pulse interacting with a cold plasma or rectilinear electron beam under cyclotron resonance condition. It is shown that with increasing amplitude and duration of an incident pulse the linear cyclotron absorption is replaced by the self-induced transparency when the pulse propagates without damping. In fact, the initial pulse decomposes to one or several solitons with amplitude and duration defined by its velocity. In a certain parameter range, the single soliton formation is accompanied by significant compression of the initial electromagnetic pulse. We suggest using the effect of self-compression for producing multigigawatt picosecond microwave pulses.
Properties of TiO{sub 2}-based transparent conducting oxide thin films on GaN(0001) surfaces
Kasai, J.; Nakao, S.; Yamada, N. [Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan); Hitosugi, T. [Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan); Advanced Institute for Materials Research (WPI-AIMR), Tohoku University, Sendai 980-8577 (Japan); Moriyama, M.; Goshonoo, K. [Toyoda Gosei Co., Ltd., Nishikasugai, Aichi 452-8564 (Japan); Hoang, N. L. H. [Department of Chemistry, University of Tokyo, Tokyo 113-0033 (Japan); Hasegawa, T. [Kanagawa Academy of Science and Technology (KAST), Kawasaki 213-0012 (Japan); Department of Chemistry, University of Tokyo, Tokyo 113-0033 (Japan)
Anatase Nb-doped TiO{sub 2} transparent conducting oxide has been formed on GaN(0001) surfaces using a sputtering method. Amorphous films deposited at room temperature were annealed at a substrate temperature of 500 deg. C in vacuum to form single-phase anatase films. Films with a thickness of 170 nm exhibited a resistivity of 8x10{sup -4} {Omega} cm with absorptance less than 5% at a wavelength of 460 nm. Furthermore, the refractive index of the Nb-doped TiO{sub 2} was well matched to that of GaN. These findings indicate that Nb-doped TiO{sub 2} is a promising material for use as transparent electrodes in GaN-based light emitting diodes (LEDs), particularly since reflection at the electrode/GaN boundary can be suppressed, enhancing the external quantum efficiency of blue LEDs.
Optimization of transparent and reflecting electrodes for amorphous silicon solar cells. Annual subcontract report, April 1, 1994--March 31, 1995
Gordon, R.G. [Harvard Univ., Cambridge, MA (United States)
Transparent and reflecting electrodes are important parts of the structure of amorphous silicon solar cells. We report improved methods for depositing zinc oxide, deposition of tin nitride as a potential reflection-enhancing diffusion barrier between the a-Si and back metal electrodes. Highly conductive and transparent fluorine-doped zinc oxide was successfully produced on small areas by atmospheric pressure CVD from a less hazardous zinc precursor, zinc acetylacetonate. The optical properties measured for tin nitride showed that the back-reflection would be decreased if tin nitride were used instead of zinc oxide as a barrier layer over silver on aluminum. Niobium-doped titanium dioxide was produced with high enough electrical conductivity so that normal voltages and fill factors were obtained for a-Si cells made on it.