WorldWideScience

Sample records for fabricating high density

  1. Method of high-density foil fabrication

    Energy Technology Data Exchange (ETDEWEB)

    Blue, Craig A.; Sikka, Vinod K.; Ohriner, Evan K.

    2003-12-16

    A method for preparing flat foils having a high density includes the steps of mixing a powdered material with a binder to form a green sheet. The green sheet is exposed to a high intensity radiative source adapted to emit radiation of wavelengths corresponding to an absorption spectrum of the powdered material. The surface of the green sheet is heated while a lower sub-surface temperature is maintained. An apparatus for preparing a foil from a green sheet using a radiation source is also disclosed.

  2. High density semiconductor nanodots by direct laser fabrication

    Science.gov (United States)

    Haghizadeh, Anahita; Yang, Haeyeon

    2016-03-01

    We report a direct method of fabricating high density nanodots on the GaAs(001) surfaces using laser irradiations on the surface. Surface images indicate that the large clumps are not accompanied with the formation of nanodots even though its density is higher than the critical density above which detrimental large clumps begin to show up in the conventional Stranski-Krastanov growth technique. Atomic force microscopy is used to image the GaAs(001) surfaces that are irradiated by high power laser pulses interferentially. The analysis suggests that high density quantum dots be fabricated directly on semiconductor surfaces.

  3. Fabrication of very high density fuel pellets of thorium dioxide

    Science.gov (United States)

    Shiratori, Tetsuo; Fukuda, Kosaku

    1993-06-01

    Very high density ThO 2 pellets were prepared without binders and lubricants from the ThO 2 powder originated by the thorium oxalate, which was aimed to simplify the fabrication process by skipping a preheat treatment. The as-received ThO 2 powder with a surface area of 4.56 m 2/g was ball-milled up to about 9 m 2/g in order to increase the green pellet density as high as possible. Both of the single-sided and the double-sided pressing were tested in the range from 2 to 5 t/cm 2 in the green pellet formation. Sintering temperature was such low as 1550°C. The pellet prepared in this experiment had a very high density in the range from about 96 to 98% TD without any cracks, in which a difference of the pellet density was not recognized in the single-sided pressing methods.

  4. High-energy-density Targets Fabricated by The University of Michigan

    Science.gov (United States)

    Klein, Sallee; Davis, J. S.; Gao, L.; Gillespie, R. S.; MacDonald, M. J.; Malamud, G.; Manuel, M. J.-E.; Wan, W. C.; Young, R. P.; Kuranz, C. C.; Keiter, P. A.; Drake, R. P.

    2016-10-01

    The University of Michigan has been fabricating their own targets for high-energy-density physics experiments for well over the past decade. We utilize the process of machined acrylic bodies and tightly toleranced mating components that serve as constraints, enabling our group to build repeatable targets. We favor traditional machining, utilizing 3D printing when it suits, taking advantage of the very best part of both of these methods of creating precision parts for our targets. Here we present several campaigns shot at the OMEGA, Titan and Trident facilities and methods used to those fabricate targets. This work is funded by the U.S. Department of Energy, through the NNSA-DS and SC-OFES Joint Program in High-Energy-Density Laboratory Plasmas, Grant Number DE-NA0002956, and the National Laser User Facility Program, Grant Number DE-NA0002719.

  5. The reasons for the high power density of fuel cells fabricated with directly deposited membranes

    Science.gov (United States)

    Vierrath, Severin; Breitwieser, Matthias; Klingele, Matthias; Britton, Benjamin; Holdcroft, Steven; Zengerle, Roland; Thiele, Simon

    2016-09-01

    In a previous study, we reported that polymer electrolyte fuel cells prepared by direct membrane deposition (DMD) produced power densities in excess of 4 W/cm2. In this study, the underlying origins that give rise to these high power densities are investigated and reported. The membranes of high power, DMD-fabricated fuel cells are relatively thin (12 μm) compared to typical benchmark, commercially available membranes. Electrochemical impedance spectroscopy, at high current densities (2.2 A/cm2) reveals that mass transport resistance was half that of reference, catalyst-coated-membranes (CCM). This is attributed to an improved oxygen supply in the cathode catalyst layer by way of a reduced propensity of flooding, and which is facilitated by an enhancement in the back diffusion of water from cathode to anode through the thin directly deposited membrane. DMD-fabricated membrane-electrode-assemblies possess 50% reduction in ionic resistance (15 mΩcm2) compared to conventional CCMs, with contributions of 9 mΩcm2 for the membrane resistance and 6 mΩcm2 for the contact resistance of the membrane and catalyst layer ionomer. The improved mass transport is responsible for 90% of the increase in power density of the DMD fuel cell, while the reduced ionic resistance accounts for a 10% of the improvement.

  6. Ultra-High Density Single Nanometer-Scale Anodic Alumina Nanofibers Fabricated by Pyrophosphoric Acid Anodizing

    Science.gov (United States)

    Kikuchi, Tatsuya; Nishinaga, Osamu; Nakajima, Daiki; Kawashima, Jun; Natsui, Shungo; Sakaguchi, Norihito; Suzuki, Ryosuke O.

    2014-12-01

    Anodic oxide fabricated by anodizing has been widely used for nanostructural engineering, but the nanomorphology is limited to only two oxides: anodic barrier and porous oxides. Therefore, the discovery of an additional anodic oxide with a unique nanofeature would expand the applicability of anodizing. Here we demonstrate the fabrication of a third-generation anodic oxide, specifically, anodic alumina nanofibers, by anodizing in a new electrolyte, pyrophosphoric acid. Ultra-high density single nanometer-scale anodic alumina nanofibers (1010 nanofibers/cm2) consisting of an amorphous, pure aluminum oxide were successfully fabricated via pyrophosphoric acid anodizing. The nanomorphologies of the anodic nanofibers can be controlled by the electrochemical conditions. Anodic tungsten oxide nanofibers can also be fabricated by pyrophosphoric acid anodizing. The aluminum surface covered by the anodic alumina nanofibers exhibited ultra-fast superhydrophilic behavior, with a contact angle of less than 1°, within 1 second. Such ultra-narrow nanofibers can be used for various nanoapplications including catalysts, wettability control, and electronic devices.

  7. Fabrication of very-low-density, high-stiffness carbon fiber/aluminum hybridized composite with ultra-low density and high stiffness (M-11)

    Science.gov (United States)

    Suzuki, Tomoo

    1993-01-01

    Fabrication of a composite material with ultra-low density and high stiffness in microgravity is the objective of the investigation. The composite structure to be obtained is a random three-dimensional array of high modulus, short carbon fibers bonded at contact points by an aluminum alloy coated on the fibers. The material is highly porous and thus has a very low density. The motivation toward the investigation, simulation experiments, choice of the component materials, and on-flight experiment during ballistic trajectory of a NASDA rocket, are described.

  8. High critical current density YBCO films and fabrication of dc-SQUIDs

    CERN Document Server

    Kuriki, S; Kawaguchi, Y; Matsuda, M; Otowa, T

    2002-01-01

    In order to improve the sensitivity of SQUID magnetometers made of high-T sub c films, we have studied the conditions of pulsed-laser deposition of YBCO films. Among the different deposition parameters examined, extensive degassing of the vacuum chamber before and precise control of the substrate temperature during the film deposition were found effective for obtaining high critical temperature T sub c and high critical current density J sub c. It was also found that the residual-resistance ratio has a clear correlation with J sub c , indicating that it can be a good, and easy to measure, index of the film quality. Films having T sub c approx 89-90 K and J sub c >= 5x10 sup 6 A cm sup - sup 2 at 77 K were used to fabricate SQUIDs without a pickup loop. Grain-boundary junctions formed on bicrystal substrates with a 30 deg. misorientation angle exhibited I sub c R sub n values of more than 100 mu V at 77 K. The well-known scaling behaviour of the relation I sub c R sub n propor to (J sup G sup B sub c) sup 1 su...

  9. High density array fabrication and readout method for a fiber optic biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Pinkel, Daniel (Walnut Creek, CA); Gray, Joe (San Francisco, CA)

    1997-01-01

    The invention relates to the fabrication and use of biosensors comprising a plurality of optical fibers each fiber having attached to its "sensor end" biological "binding partners" (molecules that specifically bind other molecules to form a binding complex such as antibody-antigen, lectin-carbohydrate, nucleic acid-nucleic acid, biotin-avidin, etc.). The biosensor preferably bears two or more different species of biological binding partner. The sensor is fabricated by providing a plurality of groups of optical fibers. Each group is treated as a batch to attach a different species of biological binding partner to the sensor ends of the fibers comprising that bundle. Each fiber, or group of fibers within a bundle, may be uniquely identified so that the fibers, or group of fibers, when later combined in an array of different fibers, can be discretely addressed. Fibers or groups of fibers are then selected and discretely separated from different bundles. The discretely separated fibers are then combined at their sensor ends to produce a high density sensor array of fibers capable of assaying simultaneously the binding of components of a test sample to the various binding partners on the different fibers of the sensor array. The transmission ends of the optical fibers are then discretely addressed to detectors--such as a multiplicity of optical sensors. An optical signal, produced by binding of the binding partner to its substrate to form a binding complex, is conducted through the optical fiber or group of fibers to a detector for each discrete test. By examining the addressed transmission ends of fibers, or groups of fibers, the addressed transmission ends can transmit unique patterns assisting in rapid sample identification by the sensor.

  10. High density array fabrication and readout method for a fiber optic biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Pinkel, D.; Gray, J.

    1997-11-25

    The invention relates to the fabrication and use of biosensors comprising a plurality of optical fibers each fiber having attached to its ``sensor end`` biological ``binding partners`` (molecules that specifically bind other molecules to form a binding complex such as antibody-antigen, lectin-carbohydrate, nucleic acid-nucleic acid, biotin-avidin, etc.). The biosensor preferably bears two or more different species of biological binding partner. The sensor is fabricated by providing a plurality of groups of optical fibers. Each group is treated as a batch to attach a different species of biological binding partner to the sensor ends of the fibers comprising that bundle. Each fiber, or group of fibers within a bundle, may be uniquely identified so that the fibers, or group of fibers, when later combined in an array of different fibers, can be discretely addressed. Fibers or groups of fibers are then selected and discretely separated from different bundles. The discretely separated fibers are then combined at their sensor ends to produce a high density sensor array of fibers capable of assaying simultaneously the binding of components of a test sample to the various binding partners on the different fibers of the sensor array. The transmission ends of the optical fibers are then discretely addressed to detectors--such as a multiplicity of optical sensors. An optical signal, produced by binding of the binding partner to its substrate to form a binding complex, is conducted through the optical fiber or group of fibers to a detector for each discrete test. By examining the addressed transmission ends of fibers, or groups of fibers, the addressed transmission ends can transmit unique patterns assisting in rapid sample identification by the sensor. 9 figs.

  11. High density array fabrication and readout method for a fiber optic biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Pinkel, Daniel (Walnut Creek, CA); Gray, Joe (San Francisco, CA); Albertson, Donna G. (Lafayette, CA)

    2002-01-01

    The invention relates to the fabrication and use of biosensors comprising a plurality of optical fibers each fiber having attached to its "sensor end" biological "binding partners" (molecules that specifically bind other molecules to form a binding complex such as antibody-antigen, lectin-carbohydrate, nucleic acid-nucleic acid, biotin-avidin, etc.). The biosensor preferably bears two or more different species of biological binding partner. The sensor is fabricated by providing a plurality of groups of optical fibers. Each group is treated as a batch to attach a different species of biological binding partner to the sensor ends of the fibers comprising that bundle. Each fiber, or group of fibers within a bundle, may be uniquely identified so that the fibers, or group of fibers, when later combined in an array of different fibers, can be discretely addressed. Fibers or groups of fibers are then selected and discretely separated from different bundles. The discretely separated fibers are then combined at their sensor ends to produce a high density sensor array of fibers capable of assaying simultaneously the binding of components of a test sample to the various binding partners on the different fibers of the sensor array. The transmission ends of the optical fibers are then discretely addressed to detectors--such as a multiplicity of optical sensors. An optical signal, produced by binding of the binding partner to its substrate to form a binding complex, is conducted through the optical fiber or group of fibers to a detector for each discrete test. By examining the addressed transmission ends of fibers, or groups of fibers, the addressed transmission ends can transmit unique patterns assisting in rapid sample identification by the sensor.

  12. High density array fabrication and readout method for a fiber optic biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Pinkel, Daniel (Walnut Creek, CA); Gray, Joe (San Francisco, CA); Albertson, Donna G. (Lafayette, CA)

    2000-01-01

    The invention relates to the fabrication and use of biosensors comprising a plurality of optical fibers each fiber having attached to its "sensor end" biological "binding partners" (molecules that specifically bind other molecules to form a binding complex such as antibody-antigen, lectin-carbohydrate, nucleic acid-nucleic acid, biotin-avidin, etc.). The biosensor preferably bears two or more different species of biological binding partner. The sensor is fabricated by providing a plurality of groups of optical fibers. Each group is treated as a batch to attach a different species of biological binding partner to the sensor ends of the fibers comprising that bundle. Each fiber, or group of fibers within a bundle, may be uniquely identified so that the fibers, or group of fibers, when later combined in an array of different fibers, can be discretely addressed. Fibers or groups of fibers are then selected and discretely separated from different bundles. The discretely separated fibers are then combined at their sensor ends to produce a high density sensor array of fibers capable of assaying simultaneously the binding of components of a test sample to the various binding partners on the different fibers of the sensor array. The transmission ends of the optical fibers are then discretely addressed to detectors--such as a multiplicity of optical sensors. An optical signal, produced by binding of the binding partner to its substrate to form a binding complex, is conducted through the optical fiber or group of fibers to a detector for each discrete test. By examining the addressed transmission ends of fibers, or groups of fibers, the addressed transmission ends can transmit unique patterns assisting in rapid sample identification by the sensor.

  13. Fabrication of bulk nanostructured permanent magnets with high energy density: challenges and approaches.

    Science.gov (United States)

    Yue, Ming; Zhang, Xiangyi; Liu, J Ping

    2017-03-06

    Nanostructured permanent magnetic materials, including exchange-coupled nanocomposite permanent magnets, are considered as the next generation of high-strength magnets for future applications in energy-saving and renewable energy technologies. However, fabrication of bulk nanostructured magnets remains very challenging because conventional compaction and sintering techniques cannot be used for nanostructured bulk material processing. In this paper we review recent efforts at producing bulk nanostructured single-phase and composite magnetic materials with emphasis on grain size control, anisotropy generation and interface modification.

  14. Fabrication of high-density collagen fibril matrix gels by renaturation of triple-helix collagen from gelatin.

    Science.gov (United States)

    Ohyabu, Yoshimi; Yunoki, Shunji; Hatayama, Hirosuke; Teranishi, Yoshikazu

    2013-11-01

    Collagen-based 3-D hydrogels often lack sufficient mechanical strength for tissue engineering. We developed a method for fabrication of high-density collagen fibril matrix (CFM) gels from concentrated solutions of uncleaved gelatin (UCG). Denatured random-coil UCG exhibited more rapid and efficient renaturation into collagen triple-helix than cleaved gelatin (CG) over a broad range of setting temperatures. The UCG solution formed opaque gels with high-density reconstituted collagen fibrils at 28-32 °C and transparent gels similar to CG at 5%) and elasticity (1.28 ± 0.15 kPa at 5% and 4.82 ± 0.38 kPa at 8%) with minimal cell loss. The elastic modulus of these gels was higher than that of conventional CFM containing 0.5% collagen. High-strength CFM may provide more durable hydrogels for tissue engineering and regenerative medicine.

  15. Method for fabricating ceramic filaments and high density tape casting method

    Science.gov (United States)

    Collins, Jr., Earl R. (Inventor)

    1990-01-01

    An apparatus and method is disclosed for fabricating mats of ceramic material comprising preparing a slurry of ceramic particles in a binder/solvent, charging the slurry into a vessel, forcing the slurry from the vessel into spinneret nozzles, discharging the slurry from the nozzles into the path of airjets to enhance the sinuous character of the slurry exudate and to dry it, collecting the filaments on a moving belt so that the filaments overlap each other thereby forming a mat, curing the binder therein, compressing and sintering the mat to form a sintered mat, and crushing the sintered mat to produce filament shaped fragments. A process is also disclosed for producing a tape of densely packed, bonded ceramic particles comprising forming a slurry of ceramic particles and a binder/solvent, applying the slurry to a rotating internal molding surface, applying a large centrifugal force to the slurry to compress it and force excess binder/solvent from the particles, evaporating solvent and curing the binder thereby forming layers of bonded ceramic particles and cured binder, and separating the binder layer from the layer of particles. Multilayers of ceramic particles are cast in an analogous manner on top of previously formed layers. When all of the desired layers have been cast the tape is fired to produce a sintered tape. For example, a three-layer tape is produced having outer layers of highly compressed filament shaped fragments of strontium doped lanthanum (LSM) particles and a center layer of yttria stabilized zicronia (YSZ) particles.

  16. Fabrication and characterization of high current-density, submicron, NbN/MgO/NbN tunnel junctions

    Science.gov (United States)

    Stern, J. A.; Leduc, Henry G.; Judas, A. J.

    1992-01-01

    At near-millimeter wavelengths, heterodyne receivers based on SIS tunnel junctions are the most sensitive available. However, in order to scale these results to submillimeter wavelengths, certain device properties should be scaled. The tunnel-junction's current density should be increased to reduce the RC product. The device's area should be reduced to efficiently couple power from the antenna to the mixer. Finally, the superconductor used should have a large energy gap to minimize RF losses. Most SIS mixers use Nb or Pb-alloy tunnel junctions; the gap frequency for these materials is approximately 725 GHz. Above the gap frequency, these materials exhibit losses similar to those in a normal metal. The gap frequency in NbN films is as-large-as 1440 GHz. Therefore, we have developed a process to fabricate small area (down to 0.13 sq microns), high current density, NbN/MgO/NbN tunnel junctions.

  17. Nano-structure multilayer technology fabrication of high energy density capacitors for the power electronic building book

    Energy Technology Data Exchange (ETDEWEB)

    Barbee, T.W.; Johnson, G.W.; Wagner, A.V.

    1997-10-21

    Commercially available capacitors do not meet the specifications of the Power Electronic Building Block (PEBB) concept. We have applied our propriety nanostructure multilayer materials technology to the fabrication of high density capacitors designed to remove this impediment to PEBB progress. Our nanostructure multilayer capacitors will also be enabling technology in many industrial and military applications. Examples include transient suppression (snubber capacitors), resonant circuits, and DC filtering in PEBB modules. Additionally, weapon applications require compact energy storage for detonators and pulsed-power systems. Commercial applications run the gamut from computers to lighting to communications. Steady progress over the last five years has brought us to the threshold of commercial manufacturability. We have demonstrated a working dielectric energy density of > 11 J/cm3 in 20 nF devices designed for 1 kV operation.

  18. High critical current densities in bulk MgB{sub 2} fabricated using amorphous boron

    Energy Technology Data Exchange (ETDEWEB)

    Muralidhar, Miryala; Kenta, Nozaki; Murakami, Masato [Superconducting Materials Laboratory, Department of Materials Science and Engineering, Shibaura Institute of Technology, Tokyo 135-8548 (Japan); Koblischka, Michael R. [Institute of Experimental Physics, Saarland University, P.O. Box 151150, 66041 Saarbruecken (Germany)

    2015-10-15

    We prepared bulk MgB{sub 2} from high-purity commercial powders of Mg metal (99.9% purity) and amorphous B (99% purity) powders using a single-step solid state reaction at 775 C for varying sintering duration from 1 to 10 h in pure argon atmosphere. X-ray diffraction analysis showed that all the samples were single phase MgB{sub 2}. The magnetization measurements confirmed a sharp superconducting transition with T{sub c,onset} at around 38.2-38.8 K. The critical current density (J{sub c}) values for the MgB{sub 2} samples produced at 1 h sintering time is the highest one in all processed materials here. Scanning electron microscopy analyses indicated that the sintering time has a crucial influence on the grain size. As a result, the highest J{sub c} value of 270 kA cm{sup -2} at 20 K and self-field was achieved in the sample produced at 775 C for 1 h. Our results clearly demonstrate that the optimization of the sintering conditions is essential to improve the bulk MgB{sub 2} performance. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. High energy density asymmetric pseudocapacitors fabricated by graphene/carbon nanotube/MnO2 plus carbon nanotubes nanocomposites electrode

    Science.gov (United States)

    Hung, Chung Jung; Lin, Pang; Tseng, Tseung Yuen

    2014-08-01

    Novel graphene/carbon nanotubes (CNTs)/manganese oxide (MnO2) nanocomposites plus CNTs (GMC + C) and graphene/CNTs hybrid (GC) thin-film electrodes are prepared by electrophoretic deposition (EPD). These nanocomposite electrodes exhibit high surface area and interconnected pore networks. The GMC + C nanocomposite electrode shows excellent specific capacitance of 964 F g-1 at 1 A g-1, rate capability with the residual capacitance of 529 F g-1 at 500 mV s-1, and fast Na+ diffusion with intercalation value of 6.34 × 10-7 cm2 s-1, and deintercalation value of 8.86 × 10-7 cm2 s-1. Such excellent pseudocapacitive performances are attributed to low ion/electron transport resistances and short ion/electron diffusion lengths. Furthermore, novel aqueous electrolyte-based asymmetric pseudocapacitor having 1.8 V cell voltage is successfully fabricated using GMC + C nanocomposite as a cathode and GC nanocomposite as an anode. The optimized asymmetric pseudocapacitor possesses superior performance with a maximum energy density of record high 304 Wh kg-1 and retaining 56.2% of its initial specific energy density at the power density up to 242 kW kg-1. In addition, the asymmetric cell configuration also shows excellent cycling stability with 89% specific capacitance maintained after 10,000 cycles. These results suggest that our designed asymmetric pseudocapacitors have a high potential for practical applications.

  20. Fabrication of a high-density MCM-D for a pixel detector system using a BCB/Cu technology

    CERN Document Server

    Topper, M; Engelmann, G; Fehlberg, S; Gerlach, P; Wolf, J; Ehrmann, O; Becks, K H; Reichl, H

    1999-01-01

    The MCM-D which is described here is a prototype for a pixel detector system for the planned Large Hadron Collider (LHC) at CERN, Geneva. The project is within the ATLAS experiment. The module consists of a sensor tile with an active area of 16.4 mm*60.4 mm, 16 readout chips, each serving 24*160 pixel unit cells, a module controller chip, an optical transceiver and the local signal interconnection and power distribution buses. The extremely high wiring density which is necessary to interconnect the readout chips was achieved using a thin film copper/photo-BCB process above the pixel array. The bumping of the readout chips was done by PbSn electroplating. All dice are then attached by flip-chip assembly to the sensor diodes and the local buses. The focus of this paper is a detailed description of the technologies for the fabrication of this advanced MCM-D. (10 refs).

  1. Using tobacco mosaic virus template for the fabrication of three-dimensional hierarchical microbattery electrodes with high energy and high power density

    Science.gov (United States)

    Pomerantseva, Ekaterina; Gerasopoulos, Konstantinos; Gnerlich, Markus; Odenwald, Philipp; Culver, James; Ghodssi, Reza

    2013-09-01

    We present a novel approach for the fabrication of lithium-ion microbattery electrodes which deliver high energy and high power density. The key enabling technology is the use of self-assembled Tobacco mosaic virus (TMV) nanoforests as a template for active battery materials. The self-assembling TMV is a genetically modified biological nanorod with increased metal binding properties for enhanced manufacturability. High energy density is achieved due to the active surface area increase within a given footprint by combining TMV with three-dimensional (3D) microfabricated structures. The TMV nanostructure enables high power density through larger electrode/electrolyte contact area and faster charge transport. The electrodes consist of an array of electroplated gold micropillars. The pillars are coated with the self-assembled nanoscale TMV template and subsequently metalized in-place. Active battery material (V2O5) is conformally deposited using atomic layer deposition (ALD) on the hierarchical micro/nano network. Electrochemical testing of these electrodes indicates a 3-5 fold increase in energy density, compared to the TMV-templated electrodes without micropillars, without increasing footprint area or reducing rate performance. Further increase in energy density can be achieved by increasing surface area of 3D microelements as demonstrated by fabrication and electrochemical testing of the electrodes with hollow gold micropillars. Scaling up energy density by increasing active material thickness beyond 100 nm revealed some loss in surface area which highlighted the importance of nanoscale engineering for achieving maximum energy and power density in energy storage systems.

  2. Fabrication of High T

    Science.gov (United States)

    Apperley, Miles Hyam

    1992-01-01

    Metal-clad high-T_{rm c} superconductor wires have been fabricated by conventional hot extrusion and wire drawing techniques. The fabrication processes which were used influenced the microstructure which, in turn, governed the superconducting properties of metal-clad Y-Ba-Cu-O (YBCO) and Bi-Pb-Sr-Ca-Cu-O (BPSCCO) superconductors. The ability to form these materials into long thin wires and the electrical properties of the wires were assessed. Extruded metal-clad wire was fabricated by coextruding a Cu billet containing a Ag-clad superconductor core at 920^circC and 800 ^circC for YBCO and BPSCCO materials, respectively. The deformation behaviour of the composite billets was investigated by extruding through dies with semicone angle alpha = 30 ^circ and using a range of core diameters and reduction ratios. For combinations of initial core diameter and reduction ratio, domains of deformation behaviour were established including sound flow, nonuniform flow, core fracture and sleeve fracture. Hot extruded YBCO and BPSCCO superconductor had densities estimated to be between 95% and 98% of the theoretical values. The material contained transverse cracks except for a sample of YBCO which had an addition of 10 wt% Ag. The microstructure of the YBCO material consisted of YBa _2Cu_3O{_{7-x}}, while the BPSCCO material contained an intimate mixture of the high-T _{rm c} (Bi,Pb)_2 Sr_2Ca_2Cu _3O{_ {10-x}} (110 K) and low-T _{rm c} (Bi,Pb)_2 Sr_2Ca_1Cu _2O{_ {8-x}} (80 K) phases with Ca _2CuO_3 and Sr-Ca -Cu-O impurity particles. X-ray polefigure goniometry of extruded BPSCCO superconductor revealed that the material was relatively untextured. As-extruded YBCO and BPSCCO were semiconducting. Oxygen treated YBCO had a lower normal-state resistivity than the as-extruded material, and a superconducting transition above 77 K was not achieved. Heat treatment of extruded BPSCCO regenerated superconductivity above 77 K, with the transition behaviour dependent on the proportion of high

  3. Fabrication and characterization of free-standing, high-line-density transmission gratings for the vacuum UV to soft X-ray range

    NARCIS (Netherlands)

    Goh, S.J.; Bastiaens, H.J.M.; Vratzov, B.; Huang, Q.; Bijkerk, F.; Boller, K-J.

    2015-01-01

    We present state-of-the-art high resolution transmission gratings, applicable for spectroscopy in the vacuum ultraviolet (VUV) and the soft X-ray (SRX) wavelength range, fabricated with a novel process using ultraviolet based nano imprint lithography (UV-NIL). Free-standing, high-line-density gratin

  4. Development of High Count and High Density Fabric for Home Textiles%新型高支高密家纺面料的开发实践

    Institute of Scientific and Technical Information of China (English)

    张慧霞; 郭杰; 李华辉

    2013-01-01

    There are some technical difficulties in producing high count and high density home-textile fabric with some new ifbers such as Lyocell and Modal, and these problems can be solved by technique optimization in spinning, sizing and weaving processes. This article put forward some countermeasures based on practice.%用新型纤维进行高支高密家纺面料的开发在实际生产中具有较高的难度,需要从原料选取、设备改进、工艺优化等方面来解决纱线生产、浆纱及织造过程中很多难以控制的质量问题。本文从生产实际出发,探讨了如何通过这些手段实现新型高支高密家纺面料产品的顺利生产。

  5. Development of Tencel Cotton Blended Fine High Density Small Jacquard Hometextile Fabric%Tencel棉混纺细号高密小提花家纺织物的开发

    Institute of Scientific and Technical Information of China (English)

    郭凯军; 谭徽; 刘渊民; 邓红卫

    2013-01-01

    探讨Tencel棉混纺细号高密家纺织物的生产要点.针对该产品经纱为特细号纱,织物经纬密大,生产难度比常规品种大的特点,整浆工序控制好纱线张力,使经纱增强减伸,保证浆轴质量;织造工序采用“中张力,中后梁,小开口”的工艺路线,合理配置经位置线与引纬气压,最终使得该产品的织机效率达87%左右,入库一等品率在99.8%以上.%Key points of producing Tencel cotton blended fine high density hometextile fabric were discussed. According to the fabric characteristics, such as superfine warp, larger warp density and weft density, larger difficulty in production, yarn tension should be controlled well in warping process to ensure warp strength & elongation and sizing beam quality. In weaving process, processing of middle tension and back beam, smaller shed was adopted. Warp shed line and weft inserting air pressure should be selected rationally. Finally the loom efficiency can be reached about 87%, the first grade percentage put in storage can be reached above 99. 8%.

  6. Fabrication and materials properties of high-density polyethylene (HDPE)/biphasic calcium phosphate (BCP) hybrid bone plates

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Sun Young; Youn, Min Ho; Lim, Youn Mook; Gwon, Hui Jeong; Park, Jong Seok; Nho, Young Chang [Korea Atomic Energy Research Institute, Jeongeup (Korea, Republic of)

    2010-06-15

    Biphasic calcium phosphate-reinforced high-density polyethylene (BCP/HDPE) hybrid composite is a new orthopedic biomaterial, which was made to simulate a natural bone composition. Calcium phosphate systems and HDPE hybrid composites have been used in biomedical applications without any inflammatory response. Differences in natural bone of both materials have motivated the use of coupling agents to improve their interfacial interfacial interactions. The composites were prepared using medical grade BCP powder and granular polyethylene. This material was produced by replacing the mineral component and collagen soft tissue of the bone with BCP and HDPE, respectively. As expected, increased volume fraction of either reinforcement type over 0 {approx} 50 vol.% resulted in a increased Vickers hardness and Young's modulus. Thus, BCP particle-reinforced HDPE composites possessed improved material and mechanical properties. BCP particles-reinforced composites were anisotropic due to an alignment of the particles in the matrix during a processing. On the other hand, bending and tensile strength was dramatically changed in the matrix. To change the material and mechanical properties of HDPE/BCP composites, the process of a blending was used, and its effect on the microstructure and mechanical proprieties of HDPE/BCP composites were investigated by means of FT-IR/ATR spectroscopy, XRD, FE-SEM, Vickers Hardness Testing Machine, Universal Testing Machine, Mercury Porosimeter and Ultrasonic Flaw Detector at room temperature. For the evaluation of the cell viability and proliferation onto the external surface of HDPE/BCP hybrid plates with a HaCaT cell line, which is a multipotent cell line able to differentiate towards different phenotypes under the action of biological factors, has been evaluated with in vitro studies and quantified by colormetric assays. These findings indicate that the HDPE/BCP hybrid plates are biocompatible and non-toxic.

  7. Fabrication of Multilevel Switching High Density Phase Change Data Recording Using Stacked GeTe/GeSbTe Structure

    Science.gov (United States)

    Hong, Sung-Hoon; Lee, Heon; Kim, Kang-In; Choi, Yunjung; Lee, Young-Kook

    2011-08-01

    The multilevel switching characteristics of stacked phase change materials with the structures of Ge2Sb2Te5, AgInSbTe/Ge2Sb2Te5, and GeTe/Ge2Sb2Te5 were investigated at the nano scale using nanoimprint lithography and conductive atomic force microscopy. Stacked phase change materials devices consisting of nano pillars 200 nm in diameter were fabricated using nanoimprint lithography, and their electrical characteristics were evaluated using conductive atomic force microscopy, with a pulse generator and a voltage source. The stacked GeTe/Ge2Sb2Te5 phase change materials exhibited three levels of resistance with a difference of 2 orders in magnitude between them, while the single-layer and stacked phase change materials with similar electrical resistances, such as Ge2Sb2Te5/AgInSbTe exhibited only bi level switching characteristics.

  8. High-density multicore fibers

    DEFF Research Database (Denmark)

    Takenaga, K.; Matsuo, S.; Saitoh, K.;

    2016-01-01

    High-density single-mode multicore fibers were designed and fabricated. A heterogeneous 30-core fiber realized a low crosstalk of −55 dB. A quasi-single-mode homogeneous 31-core fiber attained the highest core count as a single-mode multicore fiber....

  9. Experience of Control Superfine High Density Fabric Sizing Tension%特细号高密织物浆纱张力控制体会

    Institute of Scientific and Technical Information of China (English)

    郭圈勇; 苏晓霓

    2012-01-01

    To improve sizing beam quality of superfine high density fabric, key points of setting sizing tension in each section were analyzed. Equipment and processing of effecting sizing tension evenness were summarized as well as operation and management factors. Loom beam quality can be improved obviously through implement the related measures. Broken ends per loom per hour can be reduced to 0. 41,sizing efficiency can reach above 85% ,loom efficiency can reach about 84% , production of superfine density series product can be ensured successfully.%为提高特细号高密织物的浆轴质量,举例分析了浆纱各部张力的设置要点,对影响浆纱张力均匀性的设备、工艺等和操作管理因素进行了总结和归纳,并通过实施相应措施,使织轴质量有了明显的提高,织机台时断经仅为0.41根,浆纱好轴率达83%以上,织机效率在84%左右,保证了特细号高密系列品种顺利生产.

  10. Processing Adjustment Keypoints of Producing High Density Satin Stripped Fabric%生产高密缎条织物的工艺调试要点

    Institute of Scientific and Technical Information of China (English)

    董喜平

    2009-01-01

    探讨在omniplus-190型喷气织机上生产特细号高密缎条织物的工艺调整方法.针对该品种总经根数多、织机效率低、布面质量差的问题,经过试验摸索,认为在穿筘工序采用每筘4入,在穿综工序地组织采用飞穿法、边组织采用纬重平穿法,在织造工序合理设定开口角、综框高度、开口时间、后梁、停经架、上机张力、引纬工艺等参数,可使织机效率由60%左右上升到85%左右,下机一等品率达98%.%Processing adjustment method of producing super fine high density satin stripped fabric in Omniplus-190 air-jet loom was discussed. According to the problems such as total warp number is larger,loom efficiency is lower and fabric surface is worse, through test and experiences, it is considered that 4 warp per reed was adopted in reed-in process, intermittent draw was adopted to ground weave and weft rib weave draw was adopted to edge weave in draft lifting plan process. In weaving process opening angle,heald frame height, shed time,back beam, stop frame,loom tension,weft insertion processing et al should be set properly,loom efficiency could be improve from 60% to 85% ,first grade percent-age before cloth repairing could reach 98%.

  11. Fabrication and evaluation of uniform and gradient density epoxies

    Energy Technology Data Exchange (ETDEWEB)

    Domeier, L.A.; Skala, D.M.; Goods, S.H. [and others

    1997-11-01

    Filled epoxy materials which vary in density in a designed manner have been fabricated and their mechanical properties evaluated. Density variations were produced by incorporating different volume fractions of either glass microballoons (GMB) or alumina. Several different sample types were evaluated including uniform density (0.8 g/cm{sup 3} < {rho} < 2.0 g/cm{sup 3}) samples and gradient density samples (GMB only, 0.8 g/cm{sup 3} < {rho} < 1.2 g/cm{sup 3}). The uniform density specimens were evaluated for the effects of filler type and concentration on modulus and toughness. Results indicated that addition of alumina filler significantly increased the resulting modulus while addition of GMB had little measurable effect. These differences could be understood in terms of the differing moduli of the additives relative to that of the epoxy matrix. In the former case the alumina particulates had a modulus much greater than that of the epoxy while in the latter case, the modulus of the GMB additive was only slightly greater than that of the matrix. Addition of either filler significantly degraded the toughness of the composite specimens and precluded the use of gradients to enhance toughness performance. Discontinuous {open_quotes}block{close_quotes} gradients used for testing were fabricated by simple sequential pours of formulations with different GMB loadings and were evaluated for modulus, strength and ductility. Continuous gradients were fabricated in process studies by programmed shifts in the peristaltic pumping/mixing ratio of epoxies filled with either alumina or GMB. None of the continuous gradient materials were mechanically tested. These results suggest that applications utilizing gradient materials containing alumina and similar high modulus fillers to provide designed stiffness rather than improved toughness are the most appropriate targets for future investigation.

  12. Effective Ex-situ Fabrication of F-Doped SmFeAsO Wire for High Transport Critical Current Density

    Science.gov (United States)

    Fujioka, Masaya; Kota, Tomohiro; Matoba, Masanori; Ozaki, Toshinori; Takano, Yoshihiko; Kumakura, Hiroaki; Kamihara, Yoichi

    2011-06-01

    We demonstrate the fabrication of superconducting SmFeAsO1-xFx (Sm-1111) wires by using the ex-situ powder-in-tube technique. Sm-1111 powder and a binder composed of SmF3, samarium arsenide, and iron arsenide were used to synthesize the superconducting core. Although the F content of Sm-1111 is reduced in the process of ex-situ fabrication, the binder compensates by sufficiently supplementing the F content, thereby preventing a decrease in the superconducting transition temperature and a shrinkage of the superconducting volume fraction. Thus, in the superconducting Sm-1111 wire with the binder, the transport critical current density reaches the highest value of ˜4 kA/cm2 at 4.2 K.

  13. Fabrication and characterization of aluminum heavy liners for the pulse power systems of the high energy density physics program at Los Alamos

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, W.E.; Day, R.D.; Bartos, J.J.; Garcia, F.P.; Hatch, D.J.; Hannah, P.R.

    1996-09-01

    Aluminum heavy liners of three basic types have been fabricated for Los Alamos pulse power experiments. The first fabrications used a conventional hand operated lathe with high speed steel cutting tools. More recent fabrications have used numerically controlled lathes with carbide insert cutting tools. A numerically controlled Pneumo lathe with an air bearing spindle and with air bearing cross slides has been used to fabricate the most recent examples of the 3.2 gm Pegasus Precision Liner that is normally accelerated to 3 mm/{micro}s for experiments at the Pegasus II pulse power facility. The basic dimensions, including wall thickness, of fourteen of these parts have been characterized by an automated inspection machine. Liner surface finishes are measured directly by stylus profilometer and by optical interferometric analysis of cast polymeric replicas. Statistics of these measurements will be presented. Plans for future fabrication of similar and larger liners with increasingly stringent specification of wall thickness and of surface finish are described along with corresponding plans for liner characterization improvements.

  14. High-Density Diffraction Imaging and Non-Imaging Grating Elements for EUV and X-ray Spectroscopy Fabricated by DUV Reduction Photolithography Project

    Data.gov (United States)

    National Aeronautics and Space Administration — There is a need for lightweight high-density (4000+ lines/mm) novel diffraction grating elements in modern telescopes to advance EUV and X-ray astrophysics. Current...

  15. High Density Matter

    Directory of Open Access Journals (Sweden)

    Stone J.R.

    2013-12-01

    Full Text Available The microscopic composition and properties of matter at super-saturation densities have been the subject of intense investigation for decades. The scarcity of experimental and observational data has led to the necessary reliance on theoretical models. There remains great uncertainty in these models which, of necessity, have to go beyond the over-simple assumption that high density matter consists only of nucleons and leptons. Heavy strange baryons, mesons and quark matter in different forms and phases have to be included to fulfil basic requirements of fundamental laws of physics. In this contribution latest developments in construction of the Equation of State (EoS of high-density matter at zero and finite temperature assuming different composition of matter will be discussed. Critical comparison of model EoS with available experimental data from heavy ion collisions and observations on neutron stars, including gravitational mass, radii and cooling patterns and data on X-ray burst sources and low mass X-ray binaries are made. Fundamental differences between the EoS of low-density, high temperature matter, such as is created in heavy ion collisions and of high-density, low temperature compact objects is discussed.

  16. Discuss on Sizing and Weaving Process of Fine Tex and High Density Fabric%细号高密织物浆纱及生产工艺研讨

    Institute of Scientific and Technical Information of China (English)

    盛爱军

    2011-01-01

    The yarn and weaving machine of producing fine tex and high density fabric were introduced, as well as the optimization of sizing instruction and process parameters. The weaving effect was elaborated.%文章介绍了细号高密织物原料及织造设备的选择,生产过程中浆料配方及浆纱工艺参数的优选设置和织造效果。

  17. A robotics platform for automated batch fabrication of high density, microfluidics-based DNA microarrays, with applications to single cell, multiplex assays of secreted proteins.

    Science.gov (United States)

    Ahmad, Habib; Sutherland, Alex; Shin, Young Shik; Hwang, Kiwook; Qin, Lidong; Krom, Russell-John; Heath, James R

    2011-09-01

    Microfluidics flow-patterning has been utilized for the construction of chip-scale miniaturized DNA and protein barcode arrays. Such arrays have been used for specific clinical and fundamental investigations in which many proteins are assayed from single cells or other small sample sizes. However, flow-patterned arrays are hand-prepared, and so are impractical for broad applications. We describe an integrated robotics/microfluidics platform for the automated preparation of such arrays, and we apply it to the batch fabrication of up to eighteen chips of flow-patterned DNA barcodes. The resulting substrates are comparable in quality with hand-made arrays and exhibit excellent substrate-to-substrate consistency. We demonstrate the utility and reproducibility of robotics-patterned barcodes by utilizing two flow-patterned chips for highly parallel assays of a panel of secreted proteins from single macrophage cells.

  18. High-Density Diffraction Imaging and Non-Imaging Grating Elements for EUV and X-ray Spectroscopy Fabricated by DUV Reduction Photolithography Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Diffraction gratings are powerful tools for the spectral analysis of electromagnetic radiation. Properties of gratings are determined by available fabrication means...

  19. High-Thermal-Conductivity Fabrics

    Science.gov (United States)

    Chibante, L. P. Felipe

    2012-01-01

    Heat management with common textiles such as nylon and spandex is hindered by the poor thermal conductivity from the skin surface to cooling surfaces. This innovation showed marked improvement in thermal conductivity of the individual fibers and tubing, as well as components assembled from them. The problem is centered on improving the heat removal of the liquid-cooled ventilation garments (LCVGs) used by astronauts. The current design uses an extensive network of water-cooling tubes that introduces bulkiness and discomfort, and increases fatigue. Range of motion and ease of movement are affected as well. The current technology is the same as developed during the Apollo program of the 1960s. Tubing material is hand-threaded through a spandex/nylon mesh layer, in a series of loops throughout the torso and limbs such that there is close, form-fitting contact with the user. Usually, there is a nylon liner layer to improve comfort. Circulating water is chilled by an external heat exchanger (sublimator). The purpose of this innovation is to produce new LCVG components with improved thermal conductivity. This was addressed using nanocomposite engineering incorporating high-thermalconductivity nanoscale fillers in the fabric and tubing components. Specifically, carbon nanotubes were added using normal processing methods such as thermoplastic melt mixing (compounding twin screw extruder) and downstream processing (fiber spinning, tubing extrusion). Fibers were produced as yarns and woven into fabric cloths. The application of isotropic nanofillers can be modeled using a modified Nielsen Model for conductive fillers in a matrix based on Einstein s viscosity model. This is a drop-in technology with no additional equipment needed. The loading is limited by the ability to maintain adequate dispersion. Undispersed materials will plug filtering screens in processing equipment. Generally, the viscosity increases were acceptable, and allowed the filled polymers to still be

  20. Low-cost flexible supercapacitors with high-energy density based on nanostructured MnO2 and Fe2O3 thin films directly fabricated onto stainless steel

    Science.gov (United States)

    Gund, Girish S.; Dubal, Deepak P.; Chodankar, Nilesh R.; Cho, Jun Y.; Gomez-Romero, Pedro; Park, Chan; Lokhande, Chandrakant D.

    2015-07-01

    The facile and economical electrochemical and successive ionic layer adsorption and reaction (SILAR) methods have been employed in order to prepare manganese oxide (MnO2) and iron oxide (Fe2O3) thin films, respectively with the fine optimized nanostructures on highly flexible stainless steel sheet. The symmetric and asymmetric flexible-solid-state supercapacitors (FSS-SCs) of nanostructured (nanosheets for MnO2 and nanoparticles for Fe2O3) electrodes with Na2SO4/Carboxymethyl cellulose (CMC) gel as a separator and electrolyte were assembled. MnO2 as positive and negative electrodes were used to fabricate symmetric SC, while the asymmetric SC was assembled by employing MnO2 as positive and Fe2O3 as negative electrode. Furthermore, the electrochemical features of symmetric and asymmetric SCs are systematically investigated. The results verify that the fabricated symmetric and asymmetric FSS-SCs present excellent reversibility (within the voltage window of 0-1 V and 0-2 V, respectively) and good cycling stability (83 and 91%, respectively for 3000 of CV cycles). Additionally, the asymmetric SC shows maximum specific capacitance of 92 Fg-1, about 2-fold of higher energy density (41.8 Wh kg-1) than symmetric SC and excellent mechanical flexibility. Furthermore, the “real-life” demonstration of fabricated SCs to the panel of SUK confirms that asymmetric SC has 2-fold higher energy density compare to symmetric SC.

  1. 3D printing in X-ray and gamma-ray imaging: A novel method for fabricating high-density imaging apertures

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Brian W., E-mail: molinero@email.arizona.edu [Center for Gamma-Ray Imaging, University of Arizona, Tucson, Arizona 85719 (United States); Moore, Jared W.; Barrett, Harrison H. [Center for Gamma-Ray Imaging, University of Arizona, Tucson, Arizona 85719 (United States); Frye, Teresa [TechForm Advanced Casting Technology, LLC, Portland, Oregon 97222 (United States); Adler, Steven [A3DM, Portland, Oregon 97222 (United States); Sery, Joe [Tungsten Heavy Powder, San Diego, California 92121 (United States); Furenlid, Lars R. [Center for Gamma-Ray Imaging, University of Arizona, Tucson, Arizona 85719 (United States)

    2011-12-11

    Advances in 3D rapid-prototyping printers, 3D modeling software, and casting techniques allow for cost-effective fabrication of custom components in gamma-ray and X-ray imaging systems. Applications extend to new fabrication methods for custom collimators, pinholes, calibration and resolution phantoms, mounting and shielding components, and imaging apertures. Details of the fabrication process for these components, specifically the 3D printing process, cold casting with a tungsten epoxy, and lost-wax casting in platinum are presented.

  2. 3D printing in X-ray and Gamma-Ray Imaging: A novel method for fabricating high-density imaging apertures☆

    Science.gov (United States)

    Miller, Brian W.; Moore, Jared W.; Barrett, Harrison H.; Fryé, Teresa; Adler, Steven; Sery, Joe; Furenlid, Lars R.

    2011-01-01

    Advances in 3D rapid-prototyping printers, 3D modeling software, and casting techniques allow for cost-effective fabrication of custom components in gamma-ray and X-ray imaging systems. Applications extend to new fabrication methods for custom collimators, pinholes, calibration and resolution phantoms, mounting and shielding components, and imaging apertures. Details of the fabrication process for these components, specifically the 3D printing process, cold casting with a tungsten epoxy, and lost-wax casting in platinum are presented. PMID:22199414

  3. Fabrication of Stretchable Nanocomposites with High Energy Density and Low Loss from Cross-Linked PVDF Filled with Poly(dopamine) Encapsulated BaTiO3.

    Science.gov (United States)

    Xie, Yunchuan; Yu, Yangyang; Feng, Yefeng; Jiang, Wanrong; Zhang, Zhicheng

    2017-01-25

    In this report, a simple solution-cast method was employed to prepare poly(dopamine) (PDA) encapsulated BaTiO3 (BT) nanoparticle (PDA@BT) filled composites using PVDF matrix cross-linked by the free radical initiator. The effects of both the particle encapsulation and matrix cross-linking on the mechanical and dielectric properties of the composites were carefully investigated. The results suggested that the introduction of BT particles improved permittivity of the composites to ∼30 at 100 Hz when particle contents of only 7 wt % were utilized. This was attributed to the enhanced polarization, which was induced by high permittivity ceramic particles. Compared to bare BT, PDA@BT particles could be dispersed more homogeneously in the matrix, and the catechol groups of PDA layer might form chelation with free ions present in the matrix. The latter might depress the ion conduction loss in the composites. Other results revealed that the formation of hydrogen-bonding between the PDA layer and the polymer, especially the chemical cross-linking across the matrix, resulted in increased Young' modulus by ∼25%, improved breakdown strength by ∼40%, and declined conductivity by nearly 1 order of magnitude when compared to BT filled composites. The composite films filled with PDA@BTs indicated greater energy storage capacities by nearly 190% when compared to the pristine matrix. More importantly, the excellent mechanical performance allowed the composite films to adopt uni- or biaxially stretching, a crucial feature required for the realization of high breakdown strength. This work provided a facile strategy for fabrication of flexible and stretchable dielectric composites with depressed dielectric loss and enhanced energy storage capacity at low filler loadings (<10 wt %).

  4. High Density QCD

    CERN Document Server

    Ducati, M B G

    2001-01-01

    The dynamics of high partonic density QCD is presented considering, in the double logarithm approximation, the parton recombination mechanism built in the AGL formalism, developed including unitarity corrections for the nucleon as well for nucleus. It is shown that these corrections are under theoretical control. The resulting non linear evolution equation is solved in the asymptotic regime, and a comprehensive phenomenology concerning Deep Inelastic Scattering like $F_2$, $F_L$, $F_2^c$. $\\partial F_2/ \\partial \\ln Q^2$, $\\partial F^A_2/ \\partial \\ln Q^2$, etc, is presented. The connection of our formalism with the DGLAP and BFKL dynamics, and with other perturbative (K) and non-perturbative (MV-JKLW) approaches is analised in detail. The phenomena of saturation due to shadowing corrections and the relevance of this effect in ion physics and heavy quark production is emphasized. The implications to e-RHIC, HERA-A, and LHC physics and some open questions are mentioned.

  5. 纯棉细号高密紧密纱织物无PVA上浆体会%Experience of Sizing Pure Cotton Fine Count High Density Compact Yarn Fabric without PVA

    Institute of Scientific and Technical Information of China (English)

    周祥

    2012-01-01

    Sizing processing of pure cotton fine count high density compact yarn fabric without PVA was discussed. Compact yarn sizing key points were analyzed. Sizing and size film properties were contrasted in condition of adopting PVA and no PVA. Sizing test was done on compact yarn. Test test shows that sizing of pure cotton fine count high density compact yarn fabric without PVA can be realized through setting sizing processing rationally, ensuring sizing hairiness, strength and elongation in better state.%探讨纯棉细号高密紧密纱织物无PVA上浆工艺.分析了紧密纱上浆的要点,对比了含PVA浆料配方与无PVA浆料配方的浆液与浆膜性能,对紧密纱进行了上浆试验.试验证明,通过合理设置上浆工艺,保证浆纱毛羽、强力及伸长处于较佳状态,可以实现纯棉细号高密紧密纱织物的无PVA上浆.

  6. Sizing Practice of Using DH-PVA on Pure Cotton Superfine High Density Fabric%DH-PVA用于纯棉特细号高密织物的上浆实践

    Institute of Scientific and Technical Information of China (English)

    张平; 余爱琴; 杨建强

    2009-01-01

    Feasibility of using DH-PVA to size pure cotton superfine high density fabric was discussed. Three pure cotton superfine high density fabrics were sized by DH-PVA. The sizing effects and weaving effects of applying DH-PVA new formula and PVA-1799,PVA-0588 raw formulas were contrasted. The result shows when DH-PVA was used loom ef-ficiency could be improved while PVA-1799 could be used less or be avoided. Sizing cost could be reduced by reducing acrylic size mixture and oil smoothing agent properly.%探讨DH-PVA用于纯棉特细号高密织物上浆的可行性.应用DH-PVA对三种纯棉特细号高密织物进行了浆纱实践,对应用DH-PVA的新配方与应用PVA-1799、PVA-0588的原配方的浆纱效果及织造效果进行了对比,结果表明:应用DH-PVA可以在保证织机效率有所提高的前提下少用或不用PVA-1799,适当降低丙烯酸类浆料、油脂类平滑剂用量,从而降低浆纱成本.

  7. Fabrication Flaw Density and Distribution In Repairs to Reactor Pressure Vessel and Piping Welds

    Energy Technology Data Exchange (ETDEWEB)

    GJ Schuster, FA Simonen, SR Doctor

    2008-04-01

    The Pacific Northwest National Laboratory is developing a generalized fabrication flaw distribution for the population of nuclear reactor pressure vessels and for piping welds in U.S. operating reactors. The purpose of the generalized flaw distribution is to predict component-specific flaw densities. The estimates of fabrication flaws are intended for use in fracture mechanics structural integrity assessments. Structural integrity assessments, such as estimating the frequency of loss-of-coolant accidents, are performed by computer codes that require, as input, accurate estimates of flaw densities. Welds from four different reactor pressure vessels and a collection of archived pipes have been studied to develop empirical estimates of fabrication flaw densities. This report describes the fabrication flaw distribution and characterization in the repair weld metal of vessels and piping. This work indicates that large flaws occur in these repairs. These results show that repair flaws are complex in composition and sometimes include cracks on the ends of the repair cavities. Parametric analysis using an exponential fit is performed on the data. The relevance of construction records is established for describing fabrication processes and product forms. An analysis of these records shows there was a significant change in repair frequency over the years when these components were fabricated. A description of repair flaw morphology is provided with a discussion of fracture mechanics significance. Fabrication flaws in repairs are characterized using optimized-access, high-sensitivity nondestructive ultrasonic testing. Flaw characterizations are then validated by other nondestructive evaluation techniques and complemented by destructive testing.

  8. 高支高密多纤交织双层织物的生产%Production Practice of High-count-density Multi-ifber Interwoven Double-layer Fabric

    Institute of Scientific and Technical Information of China (English)

    李英

    2014-01-01

    介绍了高支高密多纤交织双层织物的工艺及生产流程。优选的浆料配方和整经、浆纱设备及合理的工艺配置是双层织物的关键。生产中,一次开口改为小双层开口,不断经的情况下张力偏大掌握,调整棕框高度,开口清晰,保证产品的外观风格和内在质量。%The introduced the production process of high-count-density multi-fiber interwoven double-layer fabric. The optimal selection of size formula as well as warping and sizing machines and the rational configuration of process are important to producing the fabric. During the production, by dividing one shedding motion into two small sheds, using higher tension but without the risk of end breakage, adjusting the height of harness and ensuring clear opening, fabric with both good outer appearance and internal quality can be obtained.

  9. Modelling the Effect of Weave Structure and Fabric Thread Density on Mechanical and Comfort Properties of Woven Fabrics

    Directory of Open Access Journals (Sweden)

    Maqsood Muhammad

    2016-09-01

    Full Text Available The paper investigates the effects of weave structure and fabric thread density on the comfort and mechanical properties of various test fabrics woven from polyester/cotton yarns. Three different weave structures, that is, 1/1 plain, 2/1 twill and 3/1 twill, and three different fabric densities were taken as input variables whereas air permeability, overall moisture management capacity, tensile strength and tear strength of fabrics were taken as response variables and a comparison is made of the effect of weave structure and fabric density on the response variables. The results of fabric samples were analysed in Minitab statistical software. The coefficients of determinations (R-sq values of the regression equations show a good predictive ability of the developed statistical models. The findings of the study may be helpful in deciding appropriate manufacturing specifications of woven fabrics to attain specific comfort and mechanical properties.

  10. MIXING METHOD AND SIZING PROCESS IN THE PRODUCTION OF FINE COUNT HIGH DENSITY FABRIC%细号高密织物生产过程中的调浆方法及浆纱工艺

    Institute of Scientific and Technical Information of China (English)

    单可奇

    2014-01-01

    This paper introduces split slurry method, mixing slurry method and sizing technique during the weaving process of fine count high density fabric. According to the ASG343 double slurry tank sizing machine that our company is using now, comparing two kinds of slurry mixing methods, the results show that, using mixed paste method is much better.%介绍了细号高密织物织造过程中的分体调浆方法和混合调浆方法及浆纱工艺。针对我司目前使用的ASG343型双浆槽浆纱机,比较了两种调浆方法的效果,结果表明,在ASG343型双浆槽浆纱机上,采用混合调浆方法,效果更佳。

  11. Reduction in the interface-states density of metal-oxide-semiconductor field-effect transistors fabricated on high-index Si (114) surfaces by using an external magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Molina, J., E-mail: jmolina@inaoep.mx; De La Hidalga, J.; Gutierrez, E. [Electronics Department, National Institute of Astrophysics, Optics and Electronics, Tonantzintla, 72840 (Mexico)

    2014-08-14

    After fabrication of Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) devices on high-index silicon (114) surfaces, their threshold voltage (Vth) and interface-states density (Dit) characteristics were measured under the influence of an externally applied magnetic field of B = 6 μT at room temperature. The electron flow of the MOSFET's channel presents high anisotropy on Si (114), and this effect is enhanced by using an external magnetic field B, applied parallel to the Si (114) surface but perpendicular to the electron flow direction. This special configuration results in the channel electrons experiencing a Lorentzian force which pushes the electrons closer to the Si (114)-SiO{sub 2} interface and therefore to the special morphology of the Si (114) surface. Interestingly, Dit evaluation of n-type MOSFETs fabricated on Si (114) surfaces shows that the Si (114)-SiO{sub 2} interface is of high quality so that Dit as low as ∼10{sup 10 }cm{sup −2}·eV{sup −1} are obtained for MOSFETs with channels aligned at specific orientations. Additionally, using both a small positive Vds ≤ 100 mV and B = 6 μT, the former Dit is reduced by 35% in MOSFETs whose channels are aligned parallel to row-like nanostructures formed atop Si (114) surfaces (channels having a 90° rotation), whereas Dit is increased by 25% in MOSFETs whose channels are aligned perpendicular to these nanostructures (channels having a 0° rotation). From these results, the special morphology of a high-index Si (114) plane having nanochannels on its surface opens the possibility to reduce the electron-trapping characteristics of MOSFET devices having deep-submicron features and operating at very high frequencies.

  12. High density photovoltaic

    Energy Technology Data Exchange (ETDEWEB)

    Haigh, R.E.; Jacobson, G.F.; Wojtczuk, S. [Spire Corp., Bedford, MA (United States)

    1997-10-14

    Photovoltaic technology can directly generate high voltages in a solid state material through the series interconnect of many photovoltaic diodes. We are investigating the feasibility of developing an electrically isolated, high-voltage power supply using miniature photovoltaic devices that convert optical energy to electrical energy.

  13. Development of fabrication technique of bulk high superconductor

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Gye Won; Kim, Chang Joong; Kim, Ki Baik; Lee, Ho Jin; Lee, Hee Gyoun; Kwon, Sun Chil

    1997-05-01

    In order to realize the commercial application of HTSC materials, it is necessary to develop the fabrication process of high Tc oxide superconductor materials with desired shape and for practical application and high critical current density as well as good mechanical strength which critical current density as well as good mechanical strength which can withstand high lorenz force generated at high magnetic field. Much studies have been concentrated to develop the fabrication technique for high critical current density but still there are a lot of gap which should be overcome for large scale application of HTSC materials at liquid nitrogen temperature. Recently some new fabrication techniques have been developed for YBCO bulk superconductor with high mechanical strength and critical current density. In this project, plastic extrusion and melt process techniques were studied. The components materials for the current lead and the flywheel application were fabricated and their characteristics were investigated from the view point of microstructure and phase formation during heat treatment process. (author). 64 refs., 59 figs.

  14. High Energy Density Capacitors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA?s future space science missions cannot be realized without the state of the art energy storage devices which require high energy density, high reliability, and...

  15. High sensitivity knitted fabric strain sensors

    Science.gov (United States)

    Xie, Juan; Long, Hairu; Miao, Menghe

    2016-10-01

    Wearable sensors are increasingly used in smart garments for detecting and transferring vital signals and body posture, movement and respiration. Existing fabric strain sensors made from metallized yarns have low sensitivity, poor comfort and low durability to washing. Here we report a knitted fabric strain sensor made from a cotton/stainless steel (SS) fibre blended yarn which shows much higher sensitivity than sensors knitted from metallized yarns. The fabric feels softer than pure cotton textiles owing to the ultrafine stainless steel fibres and does not lose its electrical property after washing. The reason for the high sensitivity of the cotton/SS knitted fabric sensor was explored by comparing its sensing mechanism with the knitted fabric sensor made from metallized yarns. The results show that the cotton/SS yarn-to-yarn contact resistance is highly sensitive to strain applied to hooked yarn loops.

  16. High performance carbon nanotube - polymer nanofiber hybrid fabrics

    Science.gov (United States)

    Yildiz, Ozkan; Stano, Kelly; Faraji, Shaghayegh; Stone, Corinne; Willis, Colin; Zhang, Xiangwu; Jur, Jesse S.; Bradford, Philip D.

    2015-10-01

    Stable nanoscale hybrid fabrics containing both polymer nanofibers and separate and distinct carbon nanotubes (CNTs) are highly desirable but very challenging to produce. Here, we report the first instance of such a hybrid fabric, which can be easily tailored to contain 0-100% millimeter long CNTs. The novel CNT - polymer hybrid nonwoven fabrics were created by simultaneously electrospinning nanofibers onto aligned CNT sheets which were drawn and collected on a grounded, rotating mandrel. Due to the unique properties of the CNTs, the hybrids show very high tensile strength, very small pore size, high specific surface area and electrical conductivity. In order to further examine the hybrid fabric properties, they were consolidated under pressure, and also calendered at 70 °C. After calendering, the fabric's strength increased by an order of magnitude due to increased interactions and intermingling with the CNTs. The hybrids are highly efficient as aerosol filters; consolidated hybrid fabrics with a thickness of 20 microns and areal density of only 8 g m-2 exhibited ultra low particulate (ULPA) filter performance. The flexibility of this nanofabrication method allows for the use of many different polymer systems which provides the opportunity for engineering a wide range of nanoscale hybrid materials with desired functionalities.Stable nanoscale hybrid fabrics containing both polymer nanofibers and separate and distinct carbon nanotubes (CNTs) are highly desirable but very challenging to produce. Here, we report the first instance of such a hybrid fabric, which can be easily tailored to contain 0-100% millimeter long CNTs. The novel CNT - polymer hybrid nonwoven fabrics were created by simultaneously electrospinning nanofibers onto aligned CNT sheets which were drawn and collected on a grounded, rotating mandrel. Due to the unique properties of the CNTs, the hybrids show very high tensile strength, very small pore size, high specific surface area and electrical

  17. Fabrication of ultrahigh-density nanowires by electrochemical nanolithography

    Directory of Open Access Journals (Sweden)

    Jiang Hongquan

    2011-01-01

    Full Text Available Abstract An approach has been developed to produce silver nanoparticles (AgNPs rapidly on semiconductor wafers using electrochemical deposition. The closely packed AgNPs have a density of up to 1.4 × 1011 cm-2 with good size uniformity. AgNPs retain their shape and position on the substrate when used as nanomasks for producing ultrahigh-density vertical nanowire arrays with controllable size, making it a one-step nanolithography technique. We demonstrate this method on Si/SiGe multilayer superlattices using electrochemical nanopatterning and plasma etching to obtain high-density Si/SiGe multilayer superlattice nanowires.

  18. Development of high temperature superconductors having high critical current density

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Gye Wong; Kim, C. J.; Lee, H.G.; Kwon, S. C.; Lee, H. J.; Kim, K. B.; Park, J. Y.; Jung, C. H

    2000-08-01

    Fabrication of high T{sub c} superconductors and its applications for electric power device were carried out for developing superconductor application technologies. High quality YBCO superconductors was fabricated by melt texture growth, top-seeded melt growth process and multi-seeded melt growth process and the properties was compared. The critical current density of the melt processed YBCO superconductors was about few 10,000 A/cm{sup 2} and the levitation force was 50 N. The processing time needed for the growth of the 123 single grain was greatly reduced by applying multi-seeding without no significant degradation of the levitation force. The multi-seeded melt growth process was confirmed as a time-saving and cost-effective method for the fabrication of bulk superconductors with controlled crystallographic orientation.

  19. High performance carbon nanotube--polymer nanofiber hybrid fabrics.

    Science.gov (United States)

    Yildiz, Ozkan; Stano, Kelly; Faraji, Shaghayegh; Stone, Corinne; Willis, Colin; Zhang, Xiangwu; Jur, Jesse S; Bradford, Philip D

    2015-10-28

    Stable nanoscale hybrid fabrics containing both polymer nanofibers and separate and distinct carbon nanotubes (CNTs) are highly desirable but very challenging to produce. Here, we report the first instance of such a hybrid fabric, which can be easily tailored to contain 0-100% millimeter long CNTs. The novel CNT - polymer hybrid nonwoven fabrics were created by simultaneously electrospinning nanofibers onto aligned CNT sheets which were drawn and collected on a grounded, rotating mandrel. Due to the unique properties of the CNTs, the hybrids show very high tensile strength, very small pore size, high specific surface area and electrical conductivity. In order to further examine the hybrid fabric properties, they were consolidated under pressure, and also calendered at 70 °C. After calendering, the fabric's strength increased by an order of magnitude due to increased interactions and intermingling with the CNTs. The hybrids are highly efficient as aerosol filters; consolidated hybrid fabrics with a thickness of 20 microns and areal density of only 8 g m(-2) exhibited ultra low particulate (ULPA) filter performance. The flexibility of this nanofabrication method allows for the use of many different polymer systems which provides the opportunity for engineering a wide range of nanoscale hybrid materials with desired functionalities.

  20. High Energy Density Laboratory Astrophysics

    CERN Document Server

    Lebedev, Sergey V

    2007-01-01

    During the past decade, research teams around the world have developed astrophysics-relevant research utilizing high energy-density facilities such as intense lasers and z-pinches. Every two years, at the International conference on High Energy Density Laboratory Astrophysics, scientists interested in this emerging field discuss the progress in topics covering: - Stellar evolution, stellar envelopes, opacities, radiation transport - Planetary Interiors, high-pressure EOS, dense plasma atomic physics - Supernovae, gamma-ray bursts, exploding systems, strong shocks, turbulent mixing - Supernova remnants, shock processing, radiative shocks - Astrophysical jets, high-Mach-number flows, magnetized radiative jets, magnetic reconnection - Compact object accretion disks, x-ray photoionized plasmas - Ultrastrong fields, particle acceleration, collisionless shocks. These proceedings cover many of the invited and contributed papers presented at the 6th International Conference on High Energy Density Laboratory Astrophys...

  1. Saturation and High Density QCD

    OpenAIRE

    Mueller, A. H.

    2005-01-01

    Recent progress in understanding general properties of high energy scattering near the unitarity limit, where high density gluon components of the wavefunction are dominant, is reviewed. The similarity of the QCD problem and that of reaction-diffusion processes in statistical physics is emphasized. The energy dependence of the saturation momentum and the status of geometric scaling are discussed.

  2. Fabrication of Ultralow Density Interconnected Pure Metal Foams

    Science.gov (United States)

    Burks, Edward C.; Gilbert, Dustin A.; Liu, Kai; Kucheyev, Sergei O.; Colvin, Jeffrey D.; Felter, Thomas E.

    Ultra-low density metallic nanostructures have been shown to possess interesting thermal, electrical, magnetic, chemical and mechanical properties due to their extremely high surface areas, nanoscale geometries and high porosities. Here we report the synthesis of pure metal foams using interconnected metallic nanowires with densities as low as 0.1% of their bulk density that are still mechanically stable. The highly porous monoliths are macroscopic in size (several mm) and can be created in a wide variety of shapes for application-specific needs. Preliminary studies of such metal foams have already revealed fascinating mechanical and magnetic properties, since the physical dimensions of the foams are below some of the basic length scales that govern the material properties. These foams have been used as targets for ultrabright x-ray sources. They also have a wide variety of other potential applications such as photovoltaic devices, supercapacitors, catalysts, coatings, fuel cells, etc. This work has been supported by DTRA #BRCALL08-Per3-C-2-0006, and in part by NSF DMR-1008791 and DMR-1543582. Work at LLNL was performed under the auspices of the U.S. DOE by LLNL under Contract DE-AC52-07NA27344.

  3. High density matter at RHIC

    Indian Academy of Sciences (India)

    Thomas S Ullrich

    2004-02-01

    QCD predicts a phase transition between hadronic matter and a quark-gluon plasma at high energy density. The relativistic heavy ion collider (RHIC) at Brookhaven National Laboratory is a new facility dedicated to the experimental study of matter under extreme conditions. Already the first round of experimental results at RHIC indicated that the conditions to create a new state of matter are indeed reached in the collisions of heavy nuclei. Studies of particle spectra and their correlations at low transverse momenta provide evidence of strong pressure gradients in the highly interacting dense medium and hint that we observe a system in thermal equilibrium. Recent runs with high statistics allow us to explore the regime of hard-scattering processes where the suppression of hadrons at large transverse momentum, and quenching of di-jets are observed thus providing further evidence for extreme high density matter created in collisions at RHIC.

  4. Fabrication of high efficacy selective solar absorbers

    CSIR Research Space (South Africa)

    Tile, N

    2012-03-01

    Full Text Available High efficiency tandem selective solar absorber materials of carbon in nickel oxide (C-NiO) composite were fabricated on an aluminium substrate using a simple and cost effective sol-gel process. The process involved preparation of carbon and nickel...

  5. High density fluoride glass calorimeter

    Science.gov (United States)

    Xie, Q.; Scheltzbaum, J.; Akgun, U.

    2014-04-01

    The unprecedented radiation levels in current Large Hadron Collider runs, and plans to even increase the luminosity creates a need for new detector technologies to be investigated. Quartz plates to replace the plastic scintillators in current LHC calorimeters have been proposed in recent reports. Quartz based Cherenkov calorimeters can solve the radiation damage problem, however light production and transfer have proven to be challenging. This report summarizes the results from a computational study on the performance of a high-density glass calorimeter. High-density, scintillating, fluoride glass, CHG3, was used as the active material. This glass has been developed specifically for hadron collider experiments, and is known for fast response time, in addition to high light yield. Here, the details of a Geant4 model for a sampling calorimeter prototype with 20 layers, and its hadronic as well as electromagnetic performances are reported.

  6. Effects of Fiber Denier, Fiber Cross-Sectional Shape and Fabric Density on Acoustical Behavior of Vertically Lapped Nonwoven Fabrics

    Directory of Open Access Journals (Sweden)

    Mevlut Tascan, Ph.D.

    2008-06-01

    Full Text Available Acoustical insulation and absorption properties of nonwoven fabrics depend on fiber geometry and fiber arrangement within the fabric structure. The different structures of the fibers result in different total surface areas of nonwoven fabrics. Nonwoven fabrics such as vertically lapped fabrics are ideal materials for use as acoustical insulation products, because they have high total surface. Vertically lapped nonwoven technology consists of carding, perpendicular layering of the carded webs, and through-air bonding using synthetic binder fibers. The surface area of the fabric is directly related to the denier and cross-sectional shape of the fibers in the fabric. Smaller deniers yield more fibers per unit weight of the material, higher total fiber surface area, and greater possibilities for a sound wave to interact with the fibers in the fabric structure.The research in the literature uses two methods for measuring acoustical properties of fabric materials: the impedance tube and reverberation room method. Small test samples are in the impedance tube method and sound absorption coefficient is determined at each frequency. Large reverberation rooms and large test samples are used for the reverberation room method. A direct comparative acoustical properties measurement device that was designed and fabricated at Clemson University School of Materials Science & Engineering was used to measure acoustical insulation in this research. This paper provides a description of the measurement devices and acoustical measurement data for vertically lapped nonwoven fabrics made from three different polyester fiber shape and two denier levels.

  7. High energy density aluminum battery

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Gilbert M.; Paranthaman, Mariappan Parans; Dai, Sheng; Dudney, Nancy J.; Manthiram, Arumugan; McIntyre, Timothy J.; Sun, Xiao-Guang; Liu, Hansan

    2016-10-11

    Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.

  8. High energy density aluminum battery

    Science.gov (United States)

    Brown, Gilbert M.; Paranthaman, Mariappan Parans; Dai, Sheng; Dudney, Nancy J.; Manthiram, Arumugan; McIntyre, Timothy J.; Sun, Xiao-Guang; Liu, Hansan

    2016-10-11

    Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.

  9. Ultra high energy density and fast discharge nanocomposite capacitors

    Science.gov (United States)

    Tang, Haixiong; Sodano, Henry A.

    2013-04-01

    Nanocomposites containing high dielectric permittivity ceramics embedded in high breakdown strength polymers are currently of considerable interest as a solution for the development of high energy density capacitors. However, the improvement of dielectric permittivity comes at expense of the breakdown strength leading to limit the final energy density. Here, an ultra-high energy density nanocomposite was fabricated based on high aspect ratio barium strontium titanate nanowires. The pyroelectric phase Ba0.2Sr0.8TiO3 was chosen for the nanowires combined with quenched PVDF to fabricate high energy density nanocomposite. The energy density with 7.5% Ba0.2Sr0.8TiO3 nanowires reached 14.86 J/cc at 450 MV/m, which represented a 42.9% increase in comparison to the PVDF with an energy density of 10.4 J/cc at the same electric field. The capacitors have 1138% greater than higher energy density than commercial biaxial oriented polypropylene capacitors (1.2 J/cc at 640). These results demonstrate that the high aspect ratio nanowires can be used to produce nanocomposite capacitors with greater performance than the neat polymers thus providing a novel process for the development of future pulsed-power capacitors.

  10. Fabrication of high quality ferromagnetic Josephson junctions

    Energy Technology Data Exchange (ETDEWEB)

    Weides, M. [Institute for Solid State Research, Research Centre Juelich, D-52425 Juelich (Germany) and CNI-Center of Nanoelectronic Systems for Information Technology, Research Centre Juelich, D-52425 Juelich (Germany)]. E-mail: m.weides@fz-juelich.de; Tillmann, K. [Institute for Solid State Research, Research Centre Juelich, D-52425 Juelich (Germany); Ernst Ruska-Centre for Microscopy and Spectroscopy with Electrons, Research Centre Juelich, D-52425 Juelich (Germany); Kohlstedt, H. [Institute for Solid State Research, Research Centre Juelich, D-52425 Juelich (Germany); CNI-Center of Nanoelectronic Systems for Information Technology, Research Centre Juelich, D-52425 Juelich (Germany); Department of Material Science and Engineering and Department of Physics, University of Berkeley, CA 94720 (United States)

    2006-05-15

    We present ferromagnetic Nb/Al{sub 2}O{sub 3}/Ni{sub 60}Cu{sub 40}/Nb Josephson junctions (SIFS) with an ultrathin Al{sub 2}O{sub 3} tunnel barrier. The junction fabrication was optimized regarding junction insulation and homogeneity of current transport. Using ion-beam-etching and anodic oxidation we defined and insulated the junction mesas. The additional 2 nm thin Cu-layer below the ferromagnetic NiCu (SINFS) lowered interface roughness and ensured very homogeneous current transport. A high yield of junctional devices with j {sub c} spreads less than 2% was obtained.

  11. High density arrays of micromirrors

    Energy Technology Data Exchange (ETDEWEB)

    Folta, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Decker, J. Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Kolman, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Lee, C. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Brase, J. M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    1999-02-01

    We established and achieved our goal to (1) fabricate and evaluate test structures based on the micromirror design optimized for maskless lithography applications, (2) perform system analysis and code development for the maskless lithography concept, and (3) identify specifications for micromirror arrays (MMAs) for LLNL's adaptive optics (AO) applications and conceptualize new devices.

  12. Density limits investigation and high density operation in EAST tokamak

    Science.gov (United States)

    Zheng, Xingwei; Li, Jiangang; Hu, Jiansheng; Liu, Haiqing; Jie, Yinxian; Wang, Shouxin; Li, Jiahong; Duan, Yanming; Li, Miaohui; Li, Yongchun; Zhang, Ling; Ye, Yang; Yang, Qingquan; Zhang, Tao; Cheng, Yingjie; Xu, Jichan; Wang, Liang; Xu, Liqing; Zhao, Hailin; Wang, Fudi; Lin, Shiyao; Wu, Bin; Lyu, Bo; Xu, Guosheng; Gao, Xiang; Shi, Tonghui; He, Kaiyang; Lan, Heng; Chu, Nan; Cao, Bin; Sun, Zhen; Zuo, Guizhong; Ren, Jun; Zhuang, Huidong; Li, Changzheng; Yuan, Xiaolin; Yu, Yaowei; Wang, Houyin; Chen, Yue; Wu, Jinhua; EAST Team

    2016-05-01

    Increasing the density in a tokamak is limited by the so-called density limit, which is generally performed as an appearance of disruption causing loss of plasma confinement, or a degradation of high confinement mode which could further lead to a H  →  L transition. The L-mode and H-mode density limit has been investigated in EAST tokamak. Experimental results suggest that density limits could be triggered by either edge cooling or excessive central radiation. The L-mode density limit disruption is generally triggered by edge cooling, which leads to the current profile shrinkage and then destabilizes a 2/1 tearing mode, ultimately resulting in a disruption. The L-mode density limit scaling agrees well with the Greenwald limit in EAST. The observed H-mode density limit in EAST is an operational-space limit with a value of 0.8∼ 0.9{{n}\\text{GW}} . High density H-mode heated by neutral beam injection (NBI) and lower hybrid current drive (LHCD) are analyzed, respectively. The constancy of the edge density gradients in H-mode indicates a critical limit caused perhaps by e.g. ballooning induced transport. The maximum density is accessed at the H  →  L transition which is generally caused by the excessive core radiation due to high Z impurities (Fe, Cu). Operating at a high density (>2.8× {{10}19} {{\\text{m}}-3} ) is favorable for suppressing the beam shine through NBI. High density H-mode up to 5.3× {{10}19}{{\\text{m}}-3}~≤ft(∼ 0.8{{n}\\text{GW}}\\right) could be sustained by 2 MW 4.6 GHz LHCD alone, and its current drive efficiency is studied. Statistics show that good control of impurities and recycling facilitate high density operation. With careful control of these factors, high density up to 0.93{{n}\\text{GW}} stable H-mode operation was carried out heated by 1.7 MW LHCD and 1.9 MW ion cyclotron resonance heating with supersonic molecular beam injection fueling.

  13. High rate fabrication of compression molded components

    Energy Technology Data Exchange (ETDEWEB)

    Matsen, Marc R.; Negley, Mark A.; Dykstra, William C.; Smith, Glen L.; Miller, Robert J.

    2016-04-19

    A method for fabricating a thermoplastic composite component comprises inductively heating a thermoplastic pre-form with a first induction coil by inducing current to flow in susceptor wires disposed throughout the pre-form, inductively heating smart susceptors in a molding tool to a leveling temperature with a second induction coil by applying a high-strength magnetic field having a magnetic flux that passes through surfaces of the smart susceptors, shaping the magnetic flux that passes through surfaces of the smart susceptors to flow substantially parallel to a molding surface of the smart susceptors, placing the heated pre-form between the heated smart susceptors; and applying molding pressure to the pre-form to form the composite component.

  14. A biomimic thermal fabric with high moisture permeability

    Directory of Open Access Journals (Sweden)

    Fan Jie

    2013-01-01

    Full Text Available Moisture comfort is an essential factor for functional property of thermal cloth, especially for thick thermal cloth, since thick cloth may hinder effective moisture permeation, and high moisture concentration in the micro-climate between skin and fabric would cause cold feeling. Here, we report a biomimic thermal fabric with excellent warm retention and moisture management properties. In this fabric, the warp yarn system constructs many tree-shaped channel nets in the thickness direction of the fabric. Experimental result indicates that the special hierarchic configuration of warp yarns endows the biomimic thermal fabric with a better warm retention and water vapor management properties compared with the traditional fabrics.

  15. Fabrication of internal diffraction gratings in planar fluoride glass using low-density plasma formation induced by a femtosecond laser

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Sung-Hak [Nano Machining Laboratory, KIMM (Korea Institute of Machinery and Material), 171 Jang-dong, Yuseong-Gu, Daejeon 305-343 (Korea, Republic of); Materials Research and Education Center, Department of Mechanical Engineering, Auburn University, 275 Wilmore Laboratories, Auburn, AL 36849 (United States)], E-mail: shcho@kimm.re.kr; Chang, Won-Seok; Kim, Jae-Goo [Nano Machining Laboratory, KIMM (Korea Institute of Machinery and Material), 171 Jang-dong, Yuseong-Gu, Daejeon 305-343 (Korea, Republic of); Kim, Kwang-Ryul [Department of Electronics and Computer Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Hong, Jong Wook [Materials Research and Education Center, Department of Mechanical Engineering, Auburn University, 275 Wilmore Laboratories, Auburn, AL 36849 (United States)

    2008-12-30

    The fabrication of internal diffraction gratings with photo-induced refractive index modification in planar fluoride plates was demonstrated using low-density plasma formation excited by a high-intensity femtosecond (130 fs) Ti:sapphire laser ({lambda}{sub p} = 790 nm). The refractive index modifications with diameters ranging from 350 nm to 5 {mu}m were photoinduced after plasma formation occurred upon irradiation with peak intensities of more than 1 x 10{sup 12} W/cm{sup 2}. The graded refractive index profile was fabricated to be a symmetric around from the center of the point at which low-density plasma occurred. The maximum refractive index change ({delta}n) was estimated to be 1.3 x 10{sup -2}. The low-density plasma formation (n{sub c} < 1.79 x 10{sup 27} m{sup -3}]) causes the increase of the refractive index modification with fluoride glass.

  16. High energy density nanocomposite capacitors using non-ferroelectric nanowires

    Science.gov (United States)

    Tang, Haixiong; Sodano, Henry A.

    2013-02-01

    A high energy density nanocomposite capacitor is fabricated by incorporating high aspect ratio functionalized TiO2 nanowires (NWs) into a polyvinylidene-fluoride matrix. These nanocomposites exhibited energy density as high as 12.4 J/cc at 450 MV/m, which is nine times larger than commercial biaxially oriented polypropylene polypropylene capacitors (1.2 J/cc at 640 MV/m). Also, the power density can reach 1.77 MW/cc with a discharge speed of 2.89 μs. The results presented here demonstrate that nanowires can be used to develop nanocomposite capacitors with high energy density and fast discharge speed for future pulsed-power applications.

  17. Vacuum MOCVD fabrication of high efficience cells

    Science.gov (United States)

    Partain, L. D.; Fraas, L. M.; Mcleod, P. S.; Cape, J. A.

    1985-01-01

    Vacuum metal-organic-chemical-vapor-deposition (MOCVD) is a new fabrication process with improved safety and easier scalability due to its metal rather than glass construction and its uniform multiport gas injection system. It uses source materials more efficiently than other methods because the vacuum molecular flow conditions allow the high sticking coefficient reactants to reach the substrates as undeflected molecular beams and the hot chamber walls cause the low sticking coefficient reactants to bounce off the walls and interact with the substrates many times. This high source utilization reduces the materials costs power device and substantially decreases the amounts of toxic materials that must be handled as process effluents. The molecular beams allow precise growth control. With improved source purifications, vacuum MOCVD has provided p GaAs layers with 10-micron minority carrier diffusion lengths and GaAs and GaAsSb solar cells with 20% AMO efficiencies at 59X and 99X sunlight concentration ratios. Mechanical stacking has been identified as the quickest, most direct and logical path to stacked multiple-junction solar cells that perform better than the best single-junction devices. The mechanical stack is configured for immediate use in solar arrays and allows interconnections that improve the system end-of-life performance in space.

  18. High-density lipoprotein cholesterol: How High

    Directory of Open Access Journals (Sweden)

    G Rajagopal

    2012-01-01

    Full Text Available The high-density lipoprotein cholesterol (HDL-C is considered anti-atherogenic good cholesterol. It is involved in reverse transport of lipids. Epidemiological studies have found inverse relationship of HDL-C and coronary heart disease (CHD risk. When grouped according to HDL-C, subjects having HDL-C more than 60 mg/dL had lesser risk of CHD than those having HDL-C of 40-60 mg/dL, who in turn had lesser risk than those who had HDL-C less than 40 mg/dL. No upper limit for beneficial effect of HDL-C on CHD risk has been identified. The goals of treating patients with low HDL-C have not been firmly established. Though many drugs are known to improve HDL-C concentration, statins are proven to improve CHD risk and mortality. Cholesteryl ester transfer protein (CETP is involved in metabolism of HDL-C and its inhibitors are actively being screened for clinical utility. However, final answer is still awaited on CETP-inhibitors.

  19. Characterizing 3D printing in the fabrication of variable density phantoms for quality assurance of radiotherapy.

    Science.gov (United States)

    Madamesila, Joseph; McGeachy, Philip; Villarreal Barajas, J Eduardo; Khan, Rao

    2016-01-01

    To present characterization, process flow, and applications of 3D fabricated low density phantoms for radiotherapy quality assurance (QA). A Rostock 3D printer using polystyrene was employed to print slabs of varying relative electron densities (0.18-0.75). A CT scan was used to calibrate infill-to-density and characterize uniformity of the print. Two printed low relative density rods (0.18, 0.52) were benchmarked against a commercial CT-electron-density phantom. Density scaling of Anisotropic Analytical Algorithm (AAA) was tested with EBT3 film for a 0.57 slab. Gamma criterion of 3% and 3 mm was used for analysis. 3D printed slabs demonstrated uniformity for densities 0.4-0.75. The printed 0.52 rod had close agreement with the commercial phantom. Dosimetric comparison for 0.57 density slab showed >95% agreement between calculation and measurements. 3D printing allows fabrication of variable density phantoms for QA needs of a small clinic. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  20. Importing low-density ideas to high-density revitalisation

    DEFF Research Database (Denmark)

    Anrholtz, Jens; Ibsen, Christian Lyhne; Ibsen, Flemming

    2016-01-01

    Why did union officials from a high-union-density country like Denmark choose to import an organising strategy from low-density countries such as the US and the UK? Drawing on in-depth interviews with key union officials and internal documents, the authors of this article argue two key points. Fi...... cherry-pick some elements while leaving fundamental aspects out. The study nevertheless indicates that a lack of coherency and model-fit to Danish industrial relations might hamper the positive effects of the organising strategy....

  1. High Energy Density Capacitors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Capacitor size and reliability are often limiting factors in pulse power, high speed switching, and power management and distribution (PMAD) systems. T/J...

  2. Electronic DC transformer with high power density

    NARCIS (Netherlands)

    Pavlovský, M.

    2006-01-01

    This thesis is concerned with the possibilities of increasing the power density of high-power dc-dc converters with galvanic isolation. Three cornerstones for reaching high power densities are identified as: size reduction of passive components, reduction of losses particularly in active components

  3. High density data storage principle, technology, and materials

    CERN Document Server

    Zhu, Daoben

    2009-01-01

    The explosive increase in information and the miniaturization of electronic devices demand new recording technologies and materials that combine high density, fast response, long retention time and rewriting capability. As predicted, the current silicon-based computer circuits are reaching their physical limits. Further miniaturization of the electronic components and increase in data storage density are vital for the next generation of IT equipment such as ultra high-speed mobile computing, communication devices and sophisticated sensors. This original book presents a comprehensive introduction to the significant research achievements on high-density data storage from the aspects of recording mechanisms, materials and fabrication technologies, which are promising for overcoming the physical limits of current data storage systems. The book serves as an useful guide for the development of optimized materials, technologies and device structures for future information storage, and will lead readers to the fascin...

  4. Influences of urban fabric on pyroclastic density currents at Pompeii (Italy): 1. Flow direction and deposition

    Science.gov (United States)

    Gurioli, L.; Zanella, E.; Pareschi, M. T.; Lanza, R.

    2007-05-01

    To assess ways in which the products of explosive eruptions interact with human settlements, we performed volcanological and rock magnetic analyses on the deposits of the A.D. 79 eruption at the Pompeii excavations (Italy). During this eruption the Roman town of Pompeii was covered by 2.5 m of fallout pumice and then partially destroyed by pyroclastic density currents (PDCs). Anisotropy of magnetic susceptibility measurements performed on the fine matrix of the deposits allowed the quantification of the variations in flow direction and emplacement mechanisms of the parental PDCs that entered the town. These results, integrated with volcanological field investigations, revealed that the presence of buildings, still protruding through the fallout deposits, strongly affected the distribution and accumulation of the erupted products. All of the PDCs that entered the town, even the most dilute ones, were density stratified currents in which interaction with the urban fabric occurred in the lower part of the current. The degree of interaction varied mainly as a function of obstacle height and density stratification within the current. For examples, the lower part of the EU4pf current left deposits up to 3 m thick and was able to interact with 2- to 4-m-high obstacles. However, a decrease in thickness and grain size of the deposits across the town indicates that even though the upper portion of the current was able to decouple from the lower portion, enabling it to flow over the town, it was not able to fully restore the sediment supply to the lower portion in order to maintain the deposition observed upon entry into the town.

  5. Flexible asymmetric supercapacitors with high energy and high power density in aqueous electrolytes.

    Science.gov (United States)

    Cheng, Yingwen; Zhang, Hongbo; Lu, Songtao; Varanasi, Chakrapani V; Liu, Jie

    2013-02-07

    Supercapacitors with both high energy and high power densities are critical for many practical applications. In this paper, we discuss the design and demonstrate the fabrication of flexible asymmetric supercapacitors based on nanocomposite electrodes of MnO(2), activated carbon, carbon nanotubes and graphene. The combined unique properties of each of these components enable highly flexible and mechanically strong films that can serve as electrodes directly without using any current collectors or binders. Using these flexible electrodes and a roll-up approach, asymmetric supercapacitors with 2 V working voltage were successfully fabricated. The fabricated device showed excellent rate capability, with 78% of the original capacitance retained when the scan rate was increased from 2 mV s(-1) to 500 mV s(-1). Owing to the unique composite structure, these supercapacitors were able to deliver high energy density (24 W h kg(-1)) under high power density (7.8 kW kg(-1)) conditions. These features could enable supercapacitor based energy storage systems to be very attractive for a variety of critical applications, such as the power sources in hybrid electric vehicles and the back-up powers for wind and solar energy, where both high energy density and high power density are required.

  6. High regression rate, high density hybrid fuels Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR program will investigate high energy density novel nanofuels combined with high density binders for use with an N2O oxidizer. Terves has developed...

  7. High energy density lithium batteries

    CERN Document Server

    Aifantis, Katerina E; Kumar, R Vasant

    2010-01-01

    Cell phones, portable computers and other electronic devices crucially depend on reliable, compact yet powerful batteries. Therefore, intensive research is devoted to improving performance and reducing failure rates. Rechargeable lithium-ion batteries promise significant advancement and high application potential for hybrid vehicles, biomedical devices, and everyday appliances. This monograph provides special focus on the methods and approaches for enhancing the performance of next-generation batteries through the use of nanotechnology. Deeper understanding of the mechanisms and strategies is

  8. High Volumetric Energy Density Hybrid Supercapacitors Based on Reduced Graphene Oxide Scrolls.

    Science.gov (United States)

    Rani, Janardhanan R; Thangavel, Ranjith; Oh, Se-I; Woo, Jeong Min; Chandra Das, Nayan; Kim, So-Yeon; Lee, Yun-Sung; Jang, Jae-Hyung

    2017-07-12

    The low volumetric energy density of reduced graphene oxide (rGO)-based electrodes limits its application in commercial electrochemical energy storage devices that require high-performance energy storage capacities in small volumes. The volumetric energy density of rGO-based electrode materials is very low due to their low packing density. A supercapacitor with enhanced packing density and high volumetric energy density is fabricated using doped rGO scrolls (GFNSs) as the electrode material. The restacking of rGO sheets is successfully controlled through synthesizing the doped scroll structures while increasing the packing density. The fabricated cell exhibits an ultrahigh volumetric energy density of 49.66 Wh/L with excellent cycling stability (>10 000 cycles). This unique design strategy for the electrode material has significant potential for the future supercapacitors with high volumetric energy densities.

  9. Density Estimation Trees in High Energy Physics

    CERN Document Server

    Anderlini, Lucio

    2015-01-01

    Density Estimation Trees can play an important role in exploratory data analysis for multidimensional, multi-modal data models of large samples. I briefly discuss the algorithm, a self-optimization technique based on kernel density estimation, and some applications in High Energy Physics.

  10. ANALYSIS OF WARP TENSION DURING WEAVING FABRIC WITH VARIABLE WEFT DENSITY

    Directory of Open Access Journals (Sweden)

    Yıldıray TURHAN

    2004-03-01

    Full Text Available In this study, warp tension change has been studied by changing weft density from a lower to a higher value in a weaving machine with electronic take up and electronic let off motions. For this purpose firstly, warp tension and cloth fell distance were measured at certain intervals from the beginning of weaving with a new weft density. Secondly, the length of fabric woven until the cloth fell reached its steady state value was determined. Finally, the warp tension measured until the steady state cloth fell values was analysed.

  11. Institute for High Energy Density Science

    Energy Technology Data Exchange (ETDEWEB)

    Wootton, Alan [Univ. of Texas, Austin, TX (United States)

    2017-01-13

    The project objective was for the Institute of High Energy Density Science (IHEDS) at the University of Texas at Austin to help grow the High Energy Density (HED) science community, by connecting academia with the Z Facility (Z) and associated staff at Sandia National Laboratories (SNL). IHEDS was originally motivated by common interests and complementary capabilities at SNL and the University of Texas System (UTX), in 2008.

  12. 纯棉特细号高密防羽绒布的织前生产工艺%Production Processing of Pure Cotton Super Fine High Density Down-proof Fabric

    Institute of Scientific and Technical Information of China (English)

    张国辉

    2011-01-01

    介绍CJ 7.3/7.3 681/614防羽绒布织前生产工艺要点.织前各工序要注意保持纱线的弹性、均匀纱线的张力;浆纱工序要合理选择浆料,使浆膜与纱线良好地结合;正确制定各项工艺参数,显著提高纱线的耐磨性和强力,降低毛羽,才能使织造顺利进行.%Fore-weaving processing of CJ 7. 3/7. 3 681/614 down-proof fabric were introduced. Yarn elasticity should be kept well and yarn tension should be uniform. Size mixture was selected rationally in sizing process to ensure combination of size film and yarn. Processing in each process was adjusted correctly, yarn wear-resistance and strength should be improved obviously, hairiness should be reduced, finally the fabric can be woven successfully.

  13. High energy density capacitors for low cost applications

    Science.gov (United States)

    Iyore, Omokhodion David

    Polyvinylidene fluoride (PVDF) and its copolymers with trifluoroethylene, hexafluoropropylene and chlorotrifluoroethylene are the most widely investigated ferroelectric polymers, due to their relatively high electromechanical properties and potential to achieve high energy density. [Bauer, 2010; Zhou et al., 2009] The research community has focused primarily on melt pressed or extruded films of PVDF-based polymers to obtain the highest performance with energy density up to 25 Jcm-3. [Zhou et al., 2009] Solution processing offers an inexpensive, low temperature alternative, which is also easily integrated with flexible electronics. This dissertation focuses on the fabrication of solution-based polyvinylidene fluoride-hexafluoropropylene metal-insulator-metal capacitors on flexible substrates using a photolithographic process. Capacitors were optimized for maximum energy density, high dielectric strength and low leakage current density. It is demonstrated that with the right choice of solvent, electrodes, spin-casting and annealing conditions, high energy density thin film capacitors can be fabricated repeatably and reproducibly. The high electric field dielectric constants were measured and the reliabilities of the polymer capacitors were also evaluated via time-zero breakdown and time-dependent breakdown techniques. Chapter 1 develops the motivation for this work and provides a theoretical overview of dielectric materials, polarization, leakage current and dielectric breakdown. Chapter 2 is a literature review of polymer-based high energy density dielectrics and covers ferroelectric polymers, highlighting PVDF and some of its derivatives. Chapter 3 summarizes some preliminary experimental work and presents materials and electrical characterization that support the rationale for materials selection and process development. Chapter 4 discusses the fabrication of solution-processed PVDF-HFP and modification of its properties by photo-crosslinking. It is followed by a

  14. Automated Fabrication Technologies for High Performance Polymer Composites

    Science.gov (United States)

    Shuart , M. J.; Johnston, N. J.; Dexter, H. B.; Marchello, J. M.; Grenoble, R. W.

    1998-01-01

    New fabrication technologies are being exploited for building high graphite-fiber-reinforced composite structure. Stitched fiber preforms and resin film infusion have been successfully demonstrated for large, composite wing structures. Other automatic processes being developed include automated placement of tacky, drapable epoxy towpreg, automated heated head placement of consolidated ribbon/tape, and vacuum-assisted resin transfer molding. These methods have the potential to yield low cost high performance structures by fabricating composite structures to net shape out-of-autoclave.

  15. Strongly Interacting Matter at High Energy Density

    Energy Technology Data Exchange (ETDEWEB)

    McLerran,L.

    2008-09-07

    This lecture concerns the properties of strongly interacting matter (which is described by Quantum Chromodynamics) at very high energy density. I review the properties of matter at high temperature, discussing the deconfinement phase transition. At high baryon density and low temperature, large N{sub c} arguments are developed which suggest that high baryonic density matter is a third form of matter, Quarkyonic Matter, that is distinct from confined hadronic matter and deconfined matter. I finally discuss the Color Glass Condensate which controls the high energy limit of QCD, and forms the low x part of a hadron wavefunction. The Glasma is introduced as matter formed by the Color Glass Condensate which eventually thermalizes into a Quark Gluon Plasma.

  16. Methods and systems for rapid prototyping of high density circuits

    Science.gov (United States)

    Palmer, Jeremy A.; Davis, Donald W.; Chavez, Bart D.; Gallegos, Phillip L.; Wicker, Ryan B.; Medina, Francisco R.

    2008-09-02

    A preferred embodiment provides, for example, a system and method of integrating fluid media dispensing technology such as direct-write (DW) technologies with rapid prototyping (RP) technologies such as stereolithography (SL) to provide increased micro-fabrication and micro-stereolithography. A preferred embodiment of the present invention also provides, for example, a system and method for Rapid Prototyping High Density Circuit (RPHDC) manufacturing of solderless connectors and pilot devices with terminal geometries that are compatible with DW mechanisms and reduce contact resistance where the electrical system is encapsulated within structural members and manual electrical connections are eliminated in favor of automated DW traces. A preferred embodiment further provides, for example, a method of rapid prototyping comprising: fabricating a part layer using stereolithography and depositing thermally curable media onto the part layer using a fluid dispensing apparatus.

  17. Effects of Preform Density on Structure and Property of C/C-SiC Composites Fabricated by Gaseous Silicon Infiltration

    Directory of Open Access Journals (Sweden)

    CAO Yu

    2016-07-01

    Full Text Available The 3-D needled C/C preforms with different densities deposited by chemical vapor infiltration (CVI method were used to fabricate C/C-SiC composites by gaseous silicon infiltration (GSI. The porosity and CVI C thickness of the preforms were studied, and the effects of preform density on the mechanical and thermal properties of C/C-SiC composites were analyzed. The results show that with the increase of preform density, the preform porosity decreases and the CVI C thickness increases from several hundred nanometers to several microns. For the C/C-SiC composites, as the preform density increases, the residual C content increases while the density and residual Si content decreases. The SiC content first keeps at a high level of about 40% (volume fraction, which then quickly reduces. Meanwhile, the mechanical properties increase to the highest values when the preform density is 1.085g/cm3, with the flexure strength up to 308.31MP and fracture toughness up to 11.36MPa·m1/2, which then decrease as the preform density further increases. The thermal conductivity and CTE of the composites, however, decrease with the increase of preform density. It is found that when the preform porosity is too high, sufficient infiltration channels lead to more residual Si, and thinner CVI C thickness results in the severe corrosion of the reinforcing fibers by Si and lower mechanical properties. When the preform porosity is relatively low, the contents of Si and SiC quickly reduce since the infiltration channels are rapidly blocked, resulting in the formation of large closed pores and not high mechanical properties.

  18. A gyroscope fabrication method for high sensitivity and robustness to fabrication tolerances

    Science.gov (United States)

    Sung, Jungwoo; Kim, Jin Young; Seok, Seyeong; Kwon, Hyuckjin J.; Kim, Minseo; Kim, Geonhwee; Lim, Geunbae

    2014-07-01

    MEMS gyroscopes have favorable characteristics, including small size, high throughput, and low cost. The performance of MEMS gyroscopes depends on the displacement sensitivity of the capacitors. In this paper, we describe the fabrication of 300-µm-thick gyroscopes that can provide high displacement sensitivity and are robust to fabrication tolerances, i.e. deep reactive ion etch (DRIE) rate uniformity. When thick structures are perforated using DRIE to achieve high-aspect-ratio features, footing is commonly observed. However, we describe a fabrication method that circumvents problems associated with footing and side-wall etching, so that the gyroscopes can have uniform dimensions and small variations across the wafer. Using a post-fabrication translation approach, the position of capacitors is modified following DRIE, and the gap in the gyroscopes can be reduced to 3 μm, which leads to an aspect ratio of 100. Using this method, we fabricated MEMS gyroscopes that can overcome the DRIE aspect ratio limit and have capacitors with higher sensitivities than those of other gyroscopes, which typically employ substrates that are less than 100 µm thick. The gyroscope had a resonant frequency of 9.91 kHz, a quality factor of 2500 and a sensitivity of 23 mV/[deg/s].

  19. Spin polarization in high density quark matter

    DEFF Research Database (Denmark)

    Bohr, Henrik; Panda, Prafulla K.; Providênci, Constanca

    2013-01-01

    We investigate the occurrence of a ferromagnetic phase transition in high density hadronic matter (e.g., in the interior of a neutron star). This could be induced by a four-fermion interaction analogous to the one which is responsible for chiral symmetry breaking in the Nambu-Jona-Lasinio model......, to which it is related through a Fierz transformation. Flavor SU(2) and flavor SU(3) quark matter are considered. A second-order phase transition is predicted at densities about 5 times the normal nuclear matter density. It is also found that in flavor SU(3) quark matter, a first-order transition from...

  20. The high density Z-pinch

    Energy Technology Data Exchange (ETDEWEB)

    McCall, G.H.

    1988-01-01

    During the past few years techniques have been developed for producing pinches in solid deuterium. The conditions which exist in these plasmas are quiet different from those produced earlier. The pinch is formed from a fiber of solid deuterium rather than from a low density gas, and the current is driven by a low impedance, high voltage pulse generator. Because of the high initial density, it is not necessary to compress the pinch to reach thermonuclear conditions, and the confinement time required for energy production is much shorter than for a gas. The experimental results, which have been verified by experiments performed at higher current were quite surprising and encouraging. The pinch appeared to be stable for a time much longer than the Alfven radial transit time. In this paper, however, I argue that the pinch is not strictly stable, but it does not appear to disassemble in a catastrophic fashion. It appears that there may be a distinction between stability and confinement in the high density pinch. In the discussion below I will present the status of the high density Z-pinch experiments at laboratories around the world, and I will describe some of the calculational and experimental results. I will confine my remarks to recent work on the high density pinch. 17 refs. 10 figs.

  1. High Density Metamaterials for Visible Light

    Science.gov (United States)

    2016-11-28

    Split Ring Resonator Metamaterials with Fundamental Magnetic Resonance in the Middle Visible Spectrum,” Adv. Opt. Mater., vol. 2, no. 3, pp. 280–285...AFRL-AFOSR-JP-TR-2016-0097 High density metamaterials for visible light Dao Hua Zhang NANYANG TECHNOLOGICAL UNIVERSITY Final Report 11/28/2016...COVERED (From - To)  16 Jul 2014 to 15 Jul 2016 4. TITLE AND SUBTITLE High density metamaterials for visible light 5a.  CONTRACT NUMBER 5b.  GRANT

  2. A quarksonic matter at high isospin density

    CERN Document Server

    Cao, Gaoqing; Huang, Xu-Guang

    2016-01-01

    Analogous to the quarkyonic matter at high baryon density in which the quark Fermi seas and the baryonic excitations coexist, it is argued that a "quarksonic matter" phase appears at high isospin density where the quark (antiquark) Fermi seas and the mesonic excitations coexist. We explore this phase in detail in both large $N_c$ and asymptotically free limits: In large $N_c$ limit, we sketch a phase diagram for the quarksonic matter. In the asymptotically free limit, we study the pion superfluidity and thermodynamics of the quarksonic matter by using both perturbative calculations and effective model.

  3. Fabrication of ultrahigh density metal-cell-metal crossbar memory devices with only two cycles of lithography and dry-etch procedures

    KAUST Repository

    Zong, Baoyu

    2013-05-20

    A novel approach to the fabrication of metal-cell-metal trilayer memory devices was demonstrated by using only two cycles of lithography and dry-etch procedures. The fabricated ultrahigh density crossbar devices can be scaled down to ≤70 nm in half-pitch without alignment issues. Depending on the different dry-etch mechanisms in transferring high and low density nanopatterns, suitable dry-etch angles and methods are studied for the transfer of high density nanopatterns. Some novel process methods have also been developed to eliminate the sidewall and other conversion obstacles for obtaining high density of uniform metallic nanopatterns. With these methods, ultrahigh density trilayer crossbar devices (∼2 × 1010 bit cm-2-kilobit electronic memory), which are composed of built-in practical magnetoresistive nanocells, have been achieved. This scalable process that we have developed provides the relevant industries with a cheap means to commercially fabricate three-dimensional high density metal-cell-metal nanodevices. © 2013 IOP Publishing Ltd.

  4. Aromatic Polyurea Possessing High Electrical Energy Density and Low Loss

    Science.gov (United States)

    Thakur, Yash; Lin, Minren; Wu, Shan; Zhang, Q. M.

    2016-10-01

    We report the development of a dielectric polymer, poly (ether methyl ether urea) (PEMEU), which possesses a dielectric constant of 4 and is thermally stable up to 150°C. The experimental results show that the ether units are effective in softening the rigid polymer and making it thermally processable, while the high dipole moment of urea units and glass structure of the polymer leads to a low dielectric loss and low conduction loss. As a result, PEMEU high quality thin films can be fabricated which exhibit exceptionally high breakdown field of >1.5 GV/m, and a low conduction loss at fields up to the breakdown. Consequently, the PEMEU films exhibit a high charge-discharge efficiency of 90% and a high discharged energy density of 36 J/cm3.

  5. High Tc superconducting fabrication of loop antenna

    Directory of Open Access Journals (Sweden)

    Widad Mahmood Faisal

    2012-09-01

    Full Text Available Using a solid state reaction to prepared many samples of YBa2Cu3O7−δ And (YBa2Cu3O7−δ1−x(Ag2Ox by mixing the appropriate ratios of constituent oxides; BaO, CuO, and Y2O3 the mixture were ground to fine power and then calcined at 900 °C without Ag2O and 930 °C for using Ag2O as impurities. The calcined black power were grounded again and molded into pellets by applying a hydrostatic pressure from (0.3–0.6 Gpa. These pellets were sintered at 950 °C. Silver was added as impurities with the calcined powder with ratios of 0.3, 0.35 and 0.45 to increase its ductility. The transition temperature for the superconductor samples were done using non-contact technique. It is an easy and sensitive technique compared with four – point probe method. The maximum Tc was 110 K for YBa2Cu3O6.989. Evaporation deposition technique to deposited a thin film, of 2200 A° thickness on the surface of the samples and then annealed to room temperature. This technical reduces the resistance to 0.2 Ω and makes a good ohmic contact at liquid nitrogen boiling point (77 K metals of various conductivity such as copper, brass aluminum and iron were used to study the effect of eddy-current loss on them and then compared with the superconducting samples, with Ag2O or without Ag2O. The maximum power loss were obtained for the superconducting samples when they cooling at liquid nitrogen temperature. The sintered pellets were drilled manually by 6 mm drill and a slot was done along its radius, to fabricate a superconducting loop antenna for receiving magnetic field signal. The best received signal was obtained when the antenna cooled to liquid nitrogen temperature.

  6. In vitro studies of PBT Nonwoven Fabrics adsorbent for the removal of low density lipoprotein from hyperlipemia plasma

    Energy Technology Data Exchange (ETDEWEB)

    Cao Ye; Wang Hong [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610052 (China); Yang Chao [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhong Rui [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610052 (China); Lei Yu [Chengdu Blood Center, Chengdu 610041 (China); Sun Kang [State Key Lab of Metal Matrix Composites, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu Jiaxin, E-mail: jxliu8122@vip.sina.com [Institute of Blood Transfusion, Chinese Academy of Medical Sciences and Peking Union Medical College, Chengdu 610052 (China)

    2011-06-15

    Polyanion ligands such as acrylic acid (AA) and heparin were grafted on PBT Nonwoven Fabrics (PBTNF) to study their effect on the adsorption of low density lipoprotein (LDL). These modified PBTNFs were characterized by Horizontal Attenuated Total Reflectance Fourier Transform Infrared spectroscopy and X-ray Photoelectron spectroscopy. The blood compatibilities of the modified PBTNFs were examined using in vitro hemolysis rate (HR), platelet adhesion, total protein (TP) and activated partial thromboplastin time. The results showed that direct immobilized heparin could improve PBTNF-PAA's blood compatibility and decrease the adsorption capability of useful high density lipoprotein, but would possess so low bioactivity that could not further improve the absorption of LDL and TC. Since the PBTNF-PAA55-Heparin adsorbent had quite good adsorption selectivity for these proteins, it can be an excellent candidate for depletion of LDL with good blood compatibility.

  7. High energy density in multisoliton collisions

    Science.gov (United States)

    Saadatmand, Danial; Dmitriev, Sergey V.; Kevrekidis, Panayotis G.

    2015-09-01

    Solitons are very effective in transporting energy over great distances and collisions between them can produce high energy density spots of relevance to phase transformations, energy localization and defect formation among others. It is then important to study how energy density accumulation scales in multisoliton collisions. In this study, we demonstrate that the maximal energy density that can be achieved in collision of N slowly moving kinks and antikinks in the integrable sine-Gordon field, remarkably, is proportional to N2, while the total energy of the system is proportional to N . This maximal energy density can be achieved only if the difference between the number of colliding kinks and antikinks is minimal, i.e., is equal to 0 for even N and 1 for odd N and if the pattern involves an alternating array of kinks and antikinks. Interestingly, for odd (even) N the maximal energy density appears in the form of potential (kinetic) energy, while kinetic (potential) energy is equal to zero. The results of the present study rely on the analysis of the exact multisoliton solutions for N =1 ,2 , and 3 and on the numerical simulation results for N =4 ,5 ,6 , and 7. The effect of weak Hamiltonian and non-Hamiltonian perturbations on the maximal energy density in multikink collisions is also discussed as well as that of the collision relative phase. Based on these results one can speculate that the soliton collisions in the sine-Gordon field can, in principle, controllably produce very high energy density. This can have important consequences for many physical phenomena described by the Klein-Gordon equations.

  8. Supernovae and high density nuclear matter

    Energy Technology Data Exchange (ETDEWEB)

    Kahana, S.

    1986-01-01

    The role of the nuclear equation of state (EOS) in producing prompt supernova explosions is examined. Results of calculations of Baron, Cooperstein, and Kahana incorporating general relativity and a new high density EOS are presented, and the relevance of these calculations to laboratory experiments with heavy ions considered. 31 refs., 6 figs., 2 tabs.

  9. High Gluon Densities in Heavy Ions Collisions

    CERN Document Server

    Blaizot, Jean-Paul

    2016-01-01

    The early stages of heavy ion collisions are dominated by high density systems of gluons that carry each a small fraction $x$ of the momenta of the colliding nucleons. A distinguishing feature of such systems is the phenomenon of "saturation" which tames the expected growth of the gluon density as the energy of the collision increases. The onset of saturation occurs at a particular transverse momentum scale, the "saturation momentum", that emerges dynamically and that marks the onset of non-linear gluon interactions. At high energy, and for large nuclei, the saturation momentum is large compared to the typical hadronic scale, making high density gluons amenable to a description with weak coupling techniques. This paper reviews some of the challenges faced in the study of such dense systems of small $x$ gluons, and of the progress made in addressing them. The focus is on conceptual issues, and the presentation is both pedagogical, and critical. Examples where high gluon density could play a visible role in hea...

  10. High Density GEOSAT/GM Altimeter Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The high density Geosat/GM altimeter data south of 30 S have finally arrived. In addition, ERS-1 has completed more than 6 cycles of its 35-day repeat track. These...

  11. Low-cost flexible supercapacitors with high-energy density based on nanostructured MnO2 and Fe2O3 thin films directly fabricated onto stainless steel

    National Research Council Canada - National Science Library

    Gund, Girish S; Dubal, Deepak P; Chodankar, Nilesh R; Cho, Jun Y; Gomez-Romero, Pedro; Park, Chan; Lokhande, Chandrakant D

    2015-01-01

    ...) methods have been employed in order to prepare manganese oxide (MnO2) and iron oxide (Fe2O3) thin films, respectively with the fine optimized nanostructures on highly flexible stainless steel sheet...

  12. Microelectromechanical high-density energy storage/rapid release system

    Science.gov (United States)

    Rodgers, M. Steven; Allen, James J.; Meeks, Kent D.; Jensen, Brian D.; Miller, Samuel L.

    1999-08-01

    One highly desirable characteristic of electrostatically driven microelectromechanical systems (MEMS) is that they consume very little power. The corresponding drawback is that the force they produce may be inadequate for many applications. It has previously been demonstrated that gear reduction units or microtransmissions can substantially increase the torque generated by microengines. Operating speed, however, is also reduced by the transmission gear ratio. Some applications require both high speed and high force. If this output is only required for a limited period of time, then energy could be stored in a mechanical system and rapidly released upon demand. We have designed, fabricated, and demonstrated a high-density energy storage/rapid release system that accomplishes this task. Built using a 5-level surface micromachining technology, the assembly closely resembles a medieval crossbow. Energy releases on the order of tens of nanojoules have already been demonstrated, and significantly higher energy systems are under development.

  13. Laser-assisted fabrication of highly viscous alginate microsphere

    Science.gov (United States)

    Lin, Yafu; Huang, Yong

    2011-04-01

    Encapsulated microspheres have been widely used in various biomedical applications. However, fabrication of encapsulated microspheres from highly viscous materials has always been a manufacturing challenge. The objective of this study is to explore a novel metallic foil-assisted laser-induced forward transfer (LIFT), a laser-assisted fabrication technique, to make encapsulated microspheres using high sodium alginate concentration solutions. The proposed four-layer approach includes a quartz disk, a sacrificial and adhesive layer, a metallic foil, and a transferred suspension layer. It is found that the proposed four-layer modified LIFT approach provides a promising fabrication technology for making of bead-encapsulated microspheres from highly viscous solutions. During the process, the microsphere only can be formed if the direct-writing height is larger than the critical direct-writing height; otherwise, tail structured droplets are formed; and the encapsulated microsphere diameter linearly increases with the laser fluence and decreases with the sodium alginate concentration.

  14. Modeling, fabrication and high power optical characterization of plasmonic waveguides

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Lysenko, Oleg

    2015-01-01

    This paper describes modeling, fabrication and high power optical characterization of thin gold films embedded in silicon dioxide. The propagation vector of surface plasmon polaritons has been calculated by the effective index method for the wavelength range of 750-1700 nm and film thickness of 15......, 30 and 45 nm. The fabrication process of such plasmonic waveguides with width in the range of 1-100 μm and their quality inspection are described. The results of optical characterization of plasmonic waveguides using a high power laser with the peak power wavelength 1064 nm show significant deviation...

  15. A general strategy for the fabrication of high performance microsupercapacitors

    KAUST Repository

    Kurra, Narendra

    2015-06-04

    We propose a generic strategy for microsupercapacitor fabrication that integrates layers of reduced graphene oxide (rGO) and pseudocapacitive materials to create electrode heterostructures with significantly improved cycling stability and performance. Our approach involves a combination of photolithography and a simple transfer method of free-standing reduced graphene oxide film onto an Au/patterned photoresist bilayer. The resulting stack (rGO/Au/patterned resist/substrate) is then used for the electrochemical deposition of various pseudocapacitive materials before the final step of lift-off. To prove the viability of this method, we have successfully fabricated microsupercapacitors (MSCs) with the following interdigitated electrode heterostructures: MnO2/rGO, Co(OH)2/rGO and PANI/rGO. These MSCs show better performance and cycling stability compared to the single layer, (i.e., rGO-free) counterparts. The interdigitated electrode heterostructures result in MSCs with energy densities in the range of 3–12 mW h/cm3 and power densities in the range of 400–1200 mW/cm3, which is superior to the Li thin film batteries (E=10 mW h/cm3), carbon, and metal oxide based MSCs (E=1–6 mW h/cm3) while device energy densities are in the range of 1.3–5.3 mW h/cm3, corresponding power densities are in the range of 178–533 mW/cm3. These results can be explained by a facilitated nucleation model, where surface topology of the rGO film creates a favorable environment for the nucleation and growth of pseudocapacitive materials with strong interfacial contacts and enhanced surface area. This approach opens up a new avenue in fabricating MSCs involving a variety of heterostructures combining electrical double layer carbon type with Faradaic pseudocapacitive materials for enhanced electrochemical performance.

  16. Two-color QCD at high density

    Energy Technology Data Exchange (ETDEWEB)

    Boz, Tamer; Skullerud, Jon-Ivar [Department of Mathematical Physics, Maynooth University, Maynooth, Co. Kildare (Ireland); Centre for the Subatomic Structure of Matter, Adelaide University, Adelaide, SA 5005 (Australia); Giudice, Pietro [Universität Münster, Institut für Theoretische Physik, Münster (Germany); Hands, Simon [Department of Physics, College of Science, Swansea University, Swansea (United Kingdom); Williams, Anthony G. [Centre for the Subatomic Structure of Matter, Adelaide University, Adelaide, SA 5005 (Australia)

    2016-01-22

    QCD at high chemical potential has interesting properties such as deconfinement of quarks. Two-color QCD, which enables numerical simulations on the lattice, constitutes a laboratory to study QCD at high chemical potential. Among the interesting properties of two-color QCD at high density is the diquark condensation, for which we present recent results obtained on a finer lattice compared to previous studies. The quark propagator in two-color QCD at non-zero chemical potential is referred to as the Gor’kov propagator. We express the Gor’kov propagator in terms of form factors and present recent lattice simulation results.

  17. Silicon Needles Fabricated by Highly Selective Anisotropic Dry Etching and Their Field Emission Current Characteristics

    Science.gov (United States)

    Kanechika, Masakazu; Mitsushima, Yasuichi

    2000-12-01

    A new process to fabricate a silicon needle, whose tip radius is about 5 nm and aspect ratio is about 7, was developed. The silicon needles were fabricated by highly selective anisotropic dry etching. The etching mask was oxygen precipitation, which was formed by nitrogen ion implantation and the subsequent oxidation. The process is simple enough to be integrated with complementary metal-oxide-semiconductor (CMOS) circuits. The density of the silicon needle can be controlled by adjusting the dose for nitrogen ion implantation. The position of the silicon needle can be controlled by adjusting the position for nitrogen ion implantation, because silicon needles are formed only in the nitrogen ion implantation area. Furthermore, using these silicon needles as micro emitters, a field emission diode was fabricated. The Fowler-Nordheim plot shows that the field around the tip of the silicon needles was highly enhanced.

  18. Modeling, fabrication and high power optical characterization of plasmonic waveguides

    DEFF Research Database (Denmark)

    Lavrinenko, Andrei; Lysenko, Oleg

    2015-01-01

    This paper describes modeling, fabrication and high power optical characterization of thin gold films embedded in silicon dioxide. The propagation vector of surface plasmon polaritons has been calculated by the effective index method for the wavelength range of 750-1700 nm and film thickness of 1...

  19. Fabrication of high-aspect ratio SU-8 micropillar arrays

    DEFF Research Database (Denmark)

    Amato, Letizia; Keller, Stephan S.; Heiskanen, Arto

    2012-01-01

    SU-8 is the preferred photoresist for development and fabrication of high aspect ratio (HAR) three dimensional patterns. However, processing of SU-8 is a challenging task, especially when the film thickness as well as the aspect ratio is increasing and the size of the features is close to the res...

  20. Design and Fabrication of High Sensitive Piezoresistive MEMS Accelerometer

    Directory of Open Access Journals (Sweden)

    JOSHI A.B

    2008-04-01

    Full Text Available This paper addresses the design and fabrication of high sensitive single axis piezoresistive micro-accelerometer for 50 g application. MEMS based accelerometer structure comprise of flexure fixed at one end and having attached proof mass at other end. This structure is designed and simulated using Coventorware. The simulation results show the sensitivity of 4mV/g. The structure is fabricated in N type silicon (100 substrate using Silicon bulk micromachining. This paper also discuses the use of PECVD Si3N4 layer as a masking material for silicon micromachining and process flow for accelerometer.

  1. Fabrication of High Quality Three-Dimensional Photonic Crystals

    Institute of Scientific and Technical Information of China (English)

    HU Xiao-Yong; LIU Yuan-Hao; CHENG Bing-Ying; ZHANG Dao-Zhong; MENG Qing-Bo

    2004-01-01

    High quality colloidal photonic crystals made from polystyrene spheres with diameter 240nm are fabricated by the vertical deposition method. The scanning electron microscopy (SEM) and the transmittance spectrum are used to characterize the properties of the photonic crystal. The SEM images show that there are few lattice defects. The transmittance of the photonic crystal is above 75% in the pass band at 700nm and is lower than 5% at the centre of the band gap, respectively. It is found that proper concentration is a very important factor to fabricate the photonic crystal when the diameter of the spheres is lower than 300nm.

  2. Deep anisotropic dry etching of silicon microstructures by high-density plasmas

    NARCIS (Netherlands)

    Blauw, M.A.

    2004-01-01

    This thesis deals with the dry etching of deep anisotropic microstructures in monocrystalline silicon by high-density plasmas. High aspect ratio trenches are necessary in the fabrication of sensitive inertial devices such as accellerometers and gyroscopes. The etching of silicon in fluorine-based

  3. Fabrication of control rods for the High Flux Isotope Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Sease, J.D.

    1998-03-01

    The High Flux Isotope Reactor (HFIR) is a research-type nuclear reactor that was designed and built in the early 1960s and has been in continuous operation since its initial criticality in 1965. Under current plans, the HFIR is expected to continue in operation until 2035. This report updates ORNL/TM-9365, Fabrication Procedure for HFIR Control Plates, which was mainly prepared in the early 1970's but was not issued until 1984, and reflects process changes, lessons learned in the latest control rod fabrication campaign, and suggested process improvements to be considered in future campaigns. Most of the personnel involved with the initial development of the processes and in part campaigns have retired or will retire soon. Because their unlikely availability in future campaigns, emphasis has been placed on providing some explanation of why the processes were selected and some discussions about the importance of controlling critical process parameters. Contained in this report is a description of the function of control rods in the reactor, the brief history of the development of control rod fabrication processes, and a description of procedures used in the fabrication of control rods. A listing of the controlled documents and procedures used in the last fabrication campaigns is referenced in Appendix A.

  4. HIGH DENSITY QCD WITH HEAVY-IONS

    CERN Multimedia

    The Addendum 1 to Volume 2 of the CMS Physics TDR has been published The Heavy-Ion analysis group completed the writing of a TDR summarizing the CMS plans in using heavy ion collisions to study high density QCD. The document was submitted to the LHCC in March and presented in the Open Session of the LHCC on May 9th. The study of heavy-ion physics at the LHC is promising to be very exciting. LHC will open a new energy frontier in ultra-relativistic heavy-ion physics. The collision energy of heavy nuclei at sNN = 5.5 TeV will be thirty times larger than what is presently available at RHIC. We will certainly probe quark and gluon matter at unprecedented values of energy density. The prime goal of this research programme is to study the fundamental theory of the strong interaction - Quantum Chromodynamics (QCD) - in extreme conditions of temperature, density and parton momentum fraction (low-x). Such studies, with impressive experimental and theoretical advances in recent years thanks to the wealth of high-qua...

  5. High-density polymer microarrays: identifying synthetic polymers that control human embryonic stem cell growth.

    Science.gov (United States)

    Hansen, Anne; Mjoseng, Heidi K; Zhang, Rong; Kalloudis, Michail; Koutsos, Vasileios; de Sousa, Paul A; Bradley, Mark

    2014-06-01

    The fabrication of high-density polymer microarray is described, allowing the simultaneous and efficient evaluation of more than 7000 different polymers in a single-cellular-based screen. These high-density polymer arrays are applied in the search for synthetic substrates for hESCs culture. Up-scaling of the identified hit polymers enables long-term cellular cultivation and promoted successful stem-cell maintenance. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Fabrication of cermet bearings for the control system of a high temperature lithium cooled nuclear reactor

    Science.gov (United States)

    Yacobucci, H. G.; Heestand, R. L.; Kizer, D. E.

    1973-01-01

    The techniques used to fabricate cermet bearings for the fueled control drums of a liquid metal cooled reference-design reactor concept are presented. The bearings were designed for operation in lithium for as long as 5 years at temperatures to 1205 C. Two sets of bearings were fabricated from a hafnium carbide - 8-wt. % molybdenum - 2-wt. % niobium carbide cermet, and two sets were fabricated from a hafnium nitride - 10-wt. % tungsten cermet. Procedures were developed for synthesizing the material in high purity inert-atmosphere glove boxes to minimize oxygen content in order to enhance corrosion resistance. Techniques were developed for pressing cylindrical billets to conserve materials and to reduce machining requirements. Finishing was accomplished by a combination of diamond grinding, electrodischarge machining, and diamond lapping. Samples were characterized in respect to composition, impurity level, lattice parameter, microstructure and density.

  7. Fabrication of High Aspect Ratio Micro-Penning-Malmberg Gold Plated Silicon Trap Arrays

    CERN Document Server

    Narimannezhad, Alireza; Weber, Marc H; Lynn, Kelvin G

    2013-01-01

    Acquiring a portable high density charged particles trap might consist of an array of micro-Penning-Malmberg traps (microtraps) with substantially lower end barriers potential than conventional Penning-Malmberg traps [1]. We report on the progress of the fabrication of these microtraps designed for antimatter storage such as positrons. The fabrication of large length to radius aspect ratio (1000:1) microtrap arrays involved advanced techniques including photolithography, deep reactive ion etching (DRIE) of silicon wafers to achieve through-vias, gold sputtering of the wafers on the surfaces and inside the vias, and thermal compression bonding of the wafers. This paper describes the encountered issues during fabrication and addresses geometry errors and asymmetries. In order to minimize the patch effects on the lifetime of the trapped positrons, the bonded stacks were gold electroplated to achieve a uniform gold surface. We show by simulation and analytical calculation that how positrons confinement time depen...

  8. A carbon nanotube field emission cathode with high current density and long-term stability

    Science.gov (United States)

    Calderón-Colón, Xiomara; Geng, Huaizhi; Gao, Bo; An, Lei; Cao, Guohua; Zhou, Otto

    2009-08-01

    Carbon nanotube (CNT) field emitters are now being evaluated for a wide range of vacuum electronic applications. However, problems including short lifetime at high current density, instability under high voltage, poor emission uniformity, and pixel-to-pixel inconsistency are still major obstacles for device applications. We developed an electrophoretic process to fabricate composite CNT films with controlled nanotube orientation and surface density, and enhanced adhesion. The cathodes have significantly enhanced macroscopic field emission current density and long-term stability under high operating voltages. The application of this CNT electron source for high-resolution x-ray imaging is demonstrated.

  9. Fabrication and applications of highly nonlinear silica holey fibres

    OpenAIRE

    Belardi, W.; Monro, T.M.; Price, J.H.V.; Lee, J.H.; Petropoulos, P.; Richardson, D J

    2001-01-01

    Holey fibre (HF) technology provides a new way to fabricate novel highly nonlinear silica based fibres. The cladding of a HF is defined by an arrangement of air holes that run along the fibre length surrounding a central silica core. The reduction in core size and increase in refractive index contrast that is possible in a HF allows the production of fibres with extremely high effective nonlinearity. HFs can also exhibit, by design of the hole configuration [2], dispersion properties not poss...

  10. High Spectral Density Optical Communication Technologies

    CERN Document Server

    Nakazawa, Masataka; Miyazaki, Tetsuya

    2010-01-01

    The latest hot topics of high-spectral density optical communication systems using digital coherent optical fibre communication technologies are covered by this book. History and meaning of a "renaissance" of the technology, requirements to the Peta-bit/s class "new generation network" are also covered in the first part of this book. The main topics treated are electronic and optical devices, digital signal processing including forward error correction, modulation formats as well as transmission and application systems. The book serves as a reference to researchers and engineers.

  11. Controlled-surface-wettability-based fabrication of hydrogel substrates with matrix tethering density variations

    Science.gov (United States)

    Rahman, Md. Mahmudur; Lee, Donghee; Bhagirath, Divya; Zhao, Xiangshan; Band, Vimla; Ryu, Sangjin

    2014-03-01

    It is widely accepted that cells behave differently responding to the stiffness of extracellular matrix (ECM). Such observations were made by culturing cells on hydrogel substrates of tunable stiffness. However, it was recently proposed that cells actually sense how strongly they are tethered to ECM, not the local stiffness of ECM. To investigate the hypothesis, we develop constant-stiffness hydrogel substrates with varying matrix tethering density (the number of anchoring sites between the gel and the ECM protein molecules). We fabricate polyacrylamide gel of static stiffness and conjugate ECM proteins to the gel using a cross-linker. When treating the gel with the cross-linker, we control positioning of cross-linker solutions with different concentrations using superhydrophobic barriers on glass, functionalize the gel by pressing it to the aligned cross-linker solutions, and conjugate an ECM protein of constant concentration to the gel. We expect that the gel will be functionalized to different degrees depending on the concentration distribution of the cross-linker and thus the gel will have variations of matrix tethering density even with constant ECM protein concentration. We acknowledge support from Bioengineering for Human Health grant of UNL-UNMC.

  12. Beyond the local density approximation : improving density functional theory for high energy density physics applications.

    Energy Technology Data Exchange (ETDEWEB)

    Mattsson, Ann Elisabet; Modine, Normand Arthur; Desjarlais, Michael Paul; Muller, Richard Partain; Sears, Mark P.; Wright, Alan Francis

    2006-11-01

    A finite temperature version of 'exact-exchange' density functional theory (EXX) has been implemented in Sandia's Socorro code. The method uses the optimized effective potential (OEP) formalism and an efficient gradient-based iterative minimization of the energy. The derivation of the gradient is based on the density matrix, simplifying the extension to finite temperatures. A stand-alone all-electron exact-exchange capability has been developed for testing exact exchange and compatible correlation functionals on small systems. Calculations of eigenvalues for the helium atom, beryllium atom, and the hydrogen molecule are reported, showing excellent agreement with highly converged quantumMonte Carlo calculations. Several approaches to the generation of pseudopotentials for use in EXX calculations have been examined and are discussed. The difficult problem of finding a correlation functional compatible with EXX has been studied and some initial findings are reported.

  13. Fabrication

    Directory of Open Access Journals (Sweden)

    E.M.S. Azzam

    2013-12-01

    Full Text Available In the present work, the nanoclay composites were fabricated using the synthesized poly 6-(3-aminophenoxy hexane-1-thiol, poly 8-(3-aminophenoxy octane-1-thiol and poly 10-(3-aminophenoxy decane-1-thiol surfactants with gold nanoparticles. The polymeric thiol surfactants were first assembled on gold nanoparticles and then impregnated into the clay matrix. Different spectroscopic and microscopic techniques such as X-ray diffraction (XRD, Scanning electron microscope (SEM and Transmission microscope (TEM were used to characterize the fabricated nanoclay composites. The results showed that the polymeric thiol surfactants assembled on gold nanoparticles are located in the interlayer space of the clay mineral and affected the clay structure.

  14. Influence of oxygen pressure on critical current density and magnetic flux pinning structures in YBa2Cu3O7-x fabricated by chemical solution deposition

    Institute of Scientific and Technical Information of China (English)

    Ding Fa-Zhu; Gu Hong-Wei; Zhang Teng; Dai Shao-Tao; Xiao Li-Ye

    2011-01-01

    This paper studies the effect of oxygen partial pressure on the fabrication of YBa2Cu3O7-x films on (00/) LaAlO3 substrates by metalorganic deposition using trifluoroacetates (TFA-MOD). As the oxygen partial pressure increases to 1500 Pa, a great increase in the superconducting properties is observed at high magnetic fields parallel to the YBCO c axis. The cross-sectional transmission electron microscope images show that a high density of stacking faults in the size range of 10-15 nm may act as flux pinning centres to enhance the critical current density of the YBCO films

  15. Recycling of irradiated high-density polyethylene

    Science.gov (United States)

    Navratil, J.; Manas, M.; Mizera, A.; Bednarik, M.; Stanek, M.; Danek, M.

    2015-01-01

    Radiation crosslinking of high-density polyethylene (HDPE) is a well-recognized modification of improving basic material characteristics. This research paper deals with the utilization of electron beam irradiated HDPE (HDPEx) after the end of its lifetime. Powder of recycled HDPEx (irradiation dose 165 kGy) was used as a filler into powder of virgin low-density polyethylene (LDPE) in concentrations ranging from 10% to 60%. The effect of the filler on processability and mechanical behavior of the resulting mixtures was investigated. The results indicate that the processability, as well as mechanical behavior, highly depends on the amount of the filler. Melt flow index dropped from 13.7 to 0.8 g/10 min comparing the lowest and the highest concentration; however, the higher shear rate the lower difference between each concentration. Toughness and hardness, on the other hand, grew with increasing addition of the recycled HDPEx. Elastic modulus increased from 254 to 450 MPa and material hardness increased from 53 to 59 ShD. These results indicate resolving the problem of further recycling of irradiated polymer materials while taking advantage of the improved mechanical properties.

  16. High Energy Density aluminum/oxygen cell

    Science.gov (United States)

    Rudd, E. J.; Gibbons, D. W.

    An alternative to a secondary battery as the power source for vehicle propulsion is a fuel cell, an example of which is the metal/air cell using metals such as aluminum, zinc, or iron. Aluminum is a particularly attractive candidate, with high energy and power densities, environmentally acceptable and having a large, established industrial base for production and distribution. An aluminum/oxygen system is currently under development for a prototype unmanned, undersea vehicle (UUV) for the US navy and recent work has focussed upon low corrosion aluminum alloys, and an electrolyte management system for processing the by-products of the energy-producing reactions. This paper summarizes the progress made in both areas. Anode materials capable of providing high utilization factors over current densities ranging from 5 to 150 mA/cm 2 have been identified, such materials being essential to realize mission life for the UUV. With respect to the electrolyte management system, a filter/precipitator unit has been successfully operated for over 250 h in a large scale, half-cell system.

  17. 3D High Density Wave Interconnects Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Nuvotronics has developed and optimized the PolyStrataTM process for the fabrication of intricate microwave and millimeter-wave devices. These devices have primarily...

  18. Fabrication of High-Quality Niobium Superconducting Tunnel Junctions

    Institute of Scientific and Technical Information of China (English)

    XU Qin-Yin; CAO Chun-Hai; LI Meng-Yue; JIANG Yi; ZHA Shi-Tong; KANG Lin; XU Wei-Wei; CHEN Jian; WU Pei-Heng

    2011-01-01

    @@ For high-quality superconducting tunnel junctions(STJS), it is necessary to reduce leakage current as much as possible.We describe the fabrication of niobium STJs using the selective niobium(Nb) etching process and various ways to minimize the leakage current.The experiment shows that the leakage current mainly comes from shorts in the tunnel barrier layer rather than those around the junction edges.Through systematic analysis of the thin film stress, surface morphology and modified junction structures, we fabricate high-quality Nb STJs with a gap voltage of 2.8 mV and a leakage current at 1 m V as low as 8.1 % and 0.023% at 4.2K and 0.3 K, respectively.

  19. Fabricating High-Resolution X-Ray Collimators

    Science.gov (United States)

    Appleby, Michael; Atkinson, James E.; Fraser, Iain; Klinger, Jill

    2008-01-01

    A process and method for fabricating multi-grid, high-resolution rotating modulation collimators for arcsecond and sub-arcsecond x-ray and gamma-ray imaging involves photochemical machining and precision stack lamination. The special fixturing and etching techniques that have been developed are used for the fabrication of multiple high-resolution grids on a single array substrate. This technology has application in solar and astrophysics and in a number of medical imaging applications including mammography, computed tomography (CT), single photon emission computed tomography (SPECT), and gamma cameras used in nuclear medicine. This collimator improvement can also be used in non-destructive testing, hydrodynamic weapons testing, and microbeam radiation therapy.

  20. Reflecting and Polarizing Properties of Conductive Fabrics in Ultra-High Frequency Range

    Directory of Open Access Journals (Sweden)

    Oleg Kiprijanovič

    2015-09-01

    Full Text Available The system based on ultra-wide band (UWB signals was employed for qualitative estimation of attenuating, reflecting and polarizing properties of conductive fabrics, capable to prevent local static charge accumulation. Pulsed excitation of triangle monopole antenna of 6.5 cm height by rectangular electric pulses induced radiation of UWB signals with spectral density of power having maximum in ultra-high frequency (UHF range. The same antenna was used for the radiated signal receiving. Filters and amplifiers of different passband were employed to divide UHF range into subranges of 0.3-0.55 GHz, 0.55-1 GHz, 1-2 GHz and 2-4 GHz bands. The free space method, when conductive fabric samples of 50x50 cm2 were placed between transmitting and receiving antennas, was used to imitate a practical application. Received wideband signals corresponding to the defined range were detected by unbiased detectors. The fabrics made of two types of warps, containing different threads with conductive yarns, were investigated. It was estimated attenuation and reflective properties of the fabrics when electric field is collinear or perpendicular to thread direction. In the UHF range it was revealed good reflecting properties of the fabrics containing metallic component in the threads. The system has advantages but not without a certain shortcoming. Adapting it for specific tasks should lead to more effective usage, including yet unused properties of the UWB signals.

  1. Effect of resin variables on the creep behavior of high density hardwood composite panels

    Science.gov (United States)

    R.C. Tang; Jianhua Pu; C.Y Hse

    1993-01-01

    The flexural creep behavior of oriented strandboards (OSB) fabricated with mixed high, density hardwood flakes was investigated. Three types of adhesives, liquid phenolic-formaldehyde (LPF), melamine modified urea-formaldehyde (MUF), and LPF (face)/MUF (core) were chosen in this investigation. The resin contents (RC) used were 3.5 percent and 5.0 percent. The flakes...

  2. High volume fabrication of laser targets using MEMS techniques

    Science.gov (United States)

    Spindloe, C.; Arthur, G.; Hall, F.; Tomlinson, S.; Potter, R.; Kar, S.; Green, J.; Higginbotham, A.; Booth, N.; Tolley, M. K.

    2016-04-01

    The latest techniques for the fabrication of high power laser targets, using processes developed for the manufacture of Micro-Electro-Mechanical System (MEMS) devices are discussed. These laser targets are designed to meet the needs of the increased shot numbers that are available in the latest design of laser facilities. Traditionally laser targets have been fabricated using conventional machining or coarse etching processes and have been produced in quantities of 10s to low 100s. Such targets can be used for high complexity experiments such as Inertial Fusion Energy (IFE) studies and can have many complex components that need assembling and characterisation with high precision. Using the techniques that are common to MEMS devices and integrating these with an existing target fabrication capability we are able to manufacture and deliver targets to these systems. It also enables us to manufacture novel targets that have not been possible using other techniques. In addition, developments in the positioning systems that are required to deliver these targets to the laser focus are also required and a system to deliver the target to a focus of an F2 beam at 0.1Hz is discussed.

  3. Performance and microstructure of 90W­Ni­Fe high­density tungsten alloy fabricated by vacuum sintering%真空烧结制备90W­Ni­Fe高密度钨合金的性能与显微结构

    Institute of Scientific and Technical Information of China (English)

    邹俭鹏; 张兆森

    2013-01-01

      采用真空烧结法制备90W­7Ni­3Fe 高密度钨合金,通过材料试验机、SEM、XRD 等表征了材料的性能与显微结构。结果表明:钨合金的相对密度、强度、塑性均随烧结温度升高先上升后下降,1440℃烧结试样的性能最佳,其相对密度、抗弯强度、抗拉强度、伸长率和断面收缩率分别为99.2%、1920.5 MPa、1086.7 MPa、22.8%和24.4%。钨合金单纯由体心立方的钨相和面心立方的Fe3Ni2固溶体相组成,未出现其他杂质相。在1360~1460℃的烧结温度范围内,随温度的升高,钨合金断裂形态依次发生以下转变:沿晶脆性断裂、穿晶脆性断裂、韧窝韧性断裂、粘接相撕裂韧性断裂和穿晶脆性断裂。%90W­7Ni­3Fe high­density tungsten alloys were fabricated by vacuum sintering method. Material testing machine, SEM and XRD were adopted to characterize the performance and microstructure of the alloys. The results show that the relative density, strength and plasticity of tungsten alloys increase at first and decrease afterwards with the increase of the sintering temperature. The sample sintered at 1 440℃demonstrates the optimal performance. Its relative density, bending strength, tensile strength, elongation and cross section shrinkage ratio are 99.2%, 1 920 MPa, 886 MPa, 22.83%and 24.37%, respectively. The tungsten alloy is simply made up of body centered cubic tungsten phase and face centered cubic Fe3Ni2 solid solution phase. With the increase of sintering temperature, the fracture morphology of tungsten alloy is transformed from intergranular brittle fracture to transgranular brittle fracture, dimple ductile fracture, bonding phase tearing ductile fracture and transgranular brittle fracture subsequently during the sintering temperature range from 1 360 to 1 460℃.

  4. Ground state of high-density matter

    Science.gov (United States)

    Copeland, ED; Kolb, Edward W.; Lee, Kimyeong

    1988-01-01

    It is shown that if an upper bound to the false vacuum energy of the electroweak Higgs potential is satisfied, the true ground state of high-density matter is not nuclear matter, or even strange-quark matter, but rather a non-topological soliton where the electroweak symmetry is exact and the fermions are massless. This possibility is examined in the standard SU(3) sub C tensor product SU(2) sub L tensor product U(1) sub Y model. The bound to the false vacuum energy is satisfied only for a narrow range of the Higgs boson masses in the minimal electroweak model (within about 10 eV of its minimum allowed value of 6.6 GeV) and a somewhat wider range for electroweak models with a non-minimal Higgs sector.

  5. Nanotechnology for Synthetic High Density Lipoproteins

    Science.gov (United States)

    Luthi, Andrea J.; Patel, Pinal C.; Ko, Caroline H.; Mutharasan, R. Kannan; Mirkin, Chad A.; Thaxton, C. Shad

    2014-01-01

    Atherosclerosis is the disease mechanism responsible for coronary heart disease (CHD), the leading cause of death worldwide. One strategy to combat atherosclerosis is to increase the amount of circulating high density lipoproteins (HDL), which transport cholesterol from peripheral tissues to the liver for excretion. The process, known as reverse cholesterol transport, is thought to be one of the main reasons for the significant inverse correlation observed between HDL blood levels and the development of CHD. This article highlights the most common strategies for treating atherosclerosis using HDL. We further detail potential treatment opportunities that utilize nanotechnology to increase the amount of HDL in circulation. The synthesis of biomimetic HDL nanostructures that replicate the chemical and physical properties of natural HDL provides novel materials for investigating the structure-function relationships of HDL and for potential new therapeutics to combat CHD. PMID:21087901

  6. High power density carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Doyon, J.; Allen, J. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Carbonate fuel cell is a highly efficient and environmentally clean source of power generation. Many organizations worldwide are actively pursuing the development of the technology. Field demonstration of multi-MW size power plant has been initiated in 1996, a step toward commercialization before the turn of the century, Energy Research Corporation (ERC) is planning to introduce a 2.85MW commercial fuel cell power plant with an efficiency of 58%, which is quite attractive for distributed power generation. However, to further expand competitive edge over alternative systems and to achieve wider market penetration, ERC is exploring advanced carbonate fuel cells having significantly higher power densities. A more compact power plant would also stimulate interest in new markets such as ships and submarines where space limitations exist. The activities focused on reducing cell polarization and internal resistance as well as on advanced thin cell components.

  7. Growth of high-density horizontally aligned SWNT arrays using Trojan catalysts.

    Science.gov (United States)

    Hu, Yue; Kang, Lixing; Zhao, Qiuchen; Zhong, Hua; Zhang, Shuchen; Yang, Liangwei; Wang, Zequn; Lin, Jingjing; Li, Qingwen; Zhang, Zhiyong; Peng, Lianmao; Liu, Zhongfan; Zhang, Jin

    2015-01-20

    Single-walled carbon nanotube (SWNT)-based electronics have been regarded as one of the most promising candidate technologies to replace or supplement silicon-based electronics in the future. These applications require high-density horizontally aligned SWNT arrays. During the past decade, significant efforts have been directed towards growth of high-density SWNT arrays. However, obtaining SWNT arrays with suitable density and quality still remains a big challenge. Herein, we develop a rational approach to grow SWNT arrays with ultra-high density using Trojan catalysts. The density can be as high as 130 SWNTs μm(-1). Field-effect transistors fabricated with our SWNT arrays exhibit a record drive current density of -467.09 μA μm(-1) and an on-conductance of 233.55 μS μm(-1). Radio frequency transistors fabricated on these samples exhibit high intrinsic fT and fMAX of 6.94 and 14.01 GHz, respectively. These results confirm our high-density SWNT arrays are strong candidates for applications in electronics.

  8. Perpendicular patterned media for high density magnetic storage

    Science.gov (United States)

    Wong, Joyce Y.

    2000-11-01

    Current longitudinal thin-film media in magnetic hard- disk drives are facing an oncoming limit caused by the superparamagnetic effect, in which the individual grains in the medium become so small that they are no longer stable against thermal fluctuation. This situation is undesirable as the stored information may be lost within an unexpectedly short time frame. There have been several proposed solutions in addressing the superparamagnetic limit, and one of them is perpendicular patterned media. In this approach, a periodic array of magnetic pillars is defined lithographically on a non-magnetic substrate. Binary data of ``1'' or ``0'' can be stored in each of these elements, which have two possible magnetization directions perpendicular to the plane of the medium. In our perpendicular patterned media design, Ni columns of 150-230nm diameter with a 6:1 aspect ratio are embedded in an (AlGa)2O 3/GaAs substrate. The fabrication procedure uses a combination of high resolution electron beam lithography, dry etching, and electroplating. The high aspect ratio in the column is achieved by taking advantage of the high etching rate and selectivity of AlGaAs/GaAs over (AlGa)2O 3 in the Cl2 chemically assisted ion beam etching process. In addition to being a robust etching mask, the (AlGa)2O3 layer also plays an important role in the chemical mechanical polishing procedure to remove the overplated Ni mushrooms. Once the Ni columns are fabricated, magnetic characterization is performed using magnetic force microscopy and scanning magnetoresistance microscopy. The former measurement confirms that the electroplated Ni columns are magnetic while the latter determines whether the individual columns are stable enough to retain the recorded information. We have successfully demonstrated recording in our 170nm diameter Ni column array arranged in a square format using a commercial read/write head. This is the first demonstration of single magnetic column per bit data storage in a

  9. High temperature SU-8 pyrolysis for fabrication of carbon electrodes

    DEFF Research Database (Denmark)

    Hassan, Yasmin Mohamed; Caviglia, Claudia; Hemanth, Suhith

    2017-01-01

    In this work, we present the investigation of the pyrolysis parameters at high temperature (1100 °C) for the fabrication of two-dimensional pyrolytic carbon electrodes. The electrodes were fabricated by pyrolysis of lithographically patterned negative epoxy based photoresist SU-8. A central...... composite experimental design was used to identify the influence of dwell time at the highest pyrolysis temperature and heating rate on electrical, electrochemical and structural properties of the pyrolytic carbon: Van der Pauw sheet resistance measurements, cyclic voltammetry, electrochemical impedance...... spectroscopy and Raman spectroscopy were used to characterize the pyrolytic carbon. The results show that the temperature increase from 900 °C to 1100 °C improves the electrical and electrochemical properties. At 1100 °C, longer dwell time leads to lower resistivity, while the variation of the pyrolysis...

  10. Phase development and critical current density of Bi-2223 tapes fabricated by groove rolling

    Science.gov (United States)

    Iyer, A. N.; Salib, S.; Vipulanandan, C.; Salama, K.; Balachandran, U.

    1999-07-01

    The powder-in-tube technique is the most widely used method for fabricating silver-clad Bi-2223 wires and tapes. In this method the silver billet containing the precursor material is transformed to the final shape using metallurgical deformation techniques such as wire drawing and flat rolling. In the present study, a modified version of the powder-in-tube technique was adopted where the silver billet was reduced in size by groove rolling instead of wire drawing. Microstructural analysis during the initial deformation stage revealed crack formation in the superconductor core. Stress conditions during groove rolling were analysed and appropriate changes were incorporated in the deformation process. After groove rolling the wires were flat rolled to a final thickness of 250 icons/Journals/Common/mu" ALT="mu" ALIGN="TOP"/>m. Subsequent thermomechanical treatment resulted in tapes with critical current density of icons/Journals/Common/approx" ALT="approx" ALIGN="TOP"/>19700 A cm-2 (critical current of icons/Journals/Common/approx" ALT="approx" ALIGN="TOP"/>40 A).

  11. Fabrication of polystyrene hollow microspheres as laser fusion targets by optimized density-matched emulsion technique and characterization

    Indian Academy of Sciences (India)

    K K Mishra; R K Khardekar; Rashmi Singh; H C Pant

    2002-07-01

    Inertial confinement fusion, frequently referred to as ICF, inertial fusion, or laser fusion, is a means of producing energy by imploding small hollow microspheres containing thermonuclear fusion fuel. Polymer microspheres, which are used as fuel containers, can be produced by solution-based micro-encapsulation technique better known as density-matched emulsion technique. The specifications of these microspheres are very rigorous, and various aspects of the emulsion hydrodynamics associated with their production are important in controlling the final product. This paper describes about the optimization of various parameters associated with density-matched emulsion method in order to improve the surface smoothness, wall thickness uniformity and sphericity of hollow polymer microspheres. These polymer microshells have been successfully fabricated in our lab, with 3–30 m wall thickness and 50–1600 m diameters. The sphericity and wall thickness uniformity are better than 99%. Elimination of vacuoles and high yield rate has been achieved by adopting the step-wise heating of W1/O/W2 emulsion for solvent removal.

  12. High Performance Ultraviolet Photodetector Fabricated with ZnO Nanoparticles-graphene Hybrid Structures

    Institute of Scientific and Technical Information of China (English)

    Jin-yang Liu; Xin-xin Yu; Guang-hui Zhang; Yu-kun Wu; Kun Zhang; Nan Pan; Xiao-ping Wang

    2013-01-01

    Ultraviolet (UV) photodetector constructed by ZnO material has attracted intense research and commercial interest.However,its photoresistivity and photoresonse are still unsatisfied.Herein,we report a novel method to assemble ZnO nanoparticles (NPs) onto the reduced graphite oxide (RGO) sheet by simple hydrothermal process without any surfactant.It is found that the high-quality crystallized ZnO NPs with the average diameter of 5 nm are well dispersed on the RGO surface,and the density of ZnO NPs can be readily controlled by the concentration of the precursor.The photodetector fabricated with this ZnO NPs-RGO hybrid structure demonstrates an excellent photoresponse for the UV irradiation.The results make this hybrid especially suitable as a novel material for the design and fabrication of high performance UV photodector.

  13. Fabrication and characterization of high performance AIGaN/GaN HEMTs on sapphire with silicon nitride passivation

    Institute of Scientific and Technical Information of China (English)

    Zhang Renping; Yan Wei; Wang Xiaoliang; Yang Fuhua

    2011-01-01

    AIGaN/GaN high electron mobility transistors (HEMTs) with high performance were fabricated and characterized. A variety of techniques were used to improve device performance, such as AIN interlayer, silicon nitride passivation, high aspect ratio T-shaped gate, Iow resistance ohmic contact and short drain-source distance.DC and RF performances of as-fabricated HEMTs were characterized by utilizing a semiconductor characterization system and a vector network analyzer, respectively. As-fabricated devices exhibited a maximum drain current density of 1.41 A/mm and a maximum peak extrinsic transconductance of 317 mS/mm. The obtained current density is larger than those reported in the literature to date, implemented with a domestic wafer and processes. Furthermore, a unity current gain cut-off frequency of 74.3 GHz and a maximum oscillation frequency of 112.4 GHz were obtained on a device with an 80 nm gate length.

  14. An investigation of density measurement method for yarn-dyed woven fabrics based on dual-side fusion technique

    Science.gov (United States)

    Zhang, Rui; Xin, Binjie

    2016-08-01

    Yarn density is always considered as the fundamental structural parameter used for the quality evaluation of woven fabrics. The conventional yarn density measurement method is based on one-side analysis. In this paper, a novel density measurement method is developed for yarn-dyed woven fabrics based on a dual-side fusion technique. Firstly, a lab-used dual-side imaging system is established to acquire both face-side and back-side images of woven fabric and the affine transform is used for the alignment and fusion of the dual-side images. Then, the color images of the woven fabrics are transferred from the RGB to the CIE-Lab color space, and the intensity information of the image extracted from the L component is used for texture fusion and analysis. Subsequently, three image fusion methods are developed and utilized to merge the dual-side images: the weighted average method, wavelet transform method and Laplacian pyramid blending method. The fusion efficacy of each method is evaluated by three evaluation indicators and the best of them is selected to do the reconstruction of the complete fabric texture. Finally, the yarn density of the fused image is measured based on the fast Fourier transform, and the yarn alignment image could be reconstructed using the inverse fast Fourier transform. Our experimental results show that the accuracy of density measurement by using the proposed method is close to 99.44% compared with the traditional method and the robustness of this new proposed method is better than that of conventional analysis methods.

  15. Unconventional High Density Vertically Aligned Conducting Polymer

    Science.gov (United States)

    2014-08-21

    CNTs also provide a porous scaffold to deposit PEDOT via CVD. To fabricate PEDOT/ A-CNT electrodes, the conducting polymer was conformally deposited on...250μm long A-CNTs using oCVD, varying thickness from few to ten nm by controlling deoposition and polymerization times. Electron microscopy

  16. Abnormal high density lipoproteins in cerebrotendinous xanthomatosis

    Energy Technology Data Exchange (ETDEWEB)

    Shore, V. (Lawrence Livermore Lab., CA); Salen, G.; Cheng, F.W.; Forte, T.; Shefer, S.; Tint, G.S.

    1981-11-01

    The plasma lipoprotein profiles and high density lipoproteins (HDL) were characterized in patients with the genetic disease cerebrotendinous xanthomatosis (CTX). The mean HDL-cholesterol concentration in the CTX plasmas was 14.5 +/- 3.2 mg/dl, about one-third the normal value. The low HDL-cholesterol reflects a low concentration and an abnormal lipid composition of the plasma HDL. Relative to normal HDL, the cholesteryl esters are low, free cholesterol and phospholipids essentially normal, and triglycerides increased. The ratio of apoprotein (apo) to total cholesterol in the HDL of CTX was two to three times greater than normal. In the CTX HDL, the ratio of apoAI to apoAII was high, the proportion of apoC low, and a normally minor form of apoAI increased relative to other forms. The HDL in electron micrographs appeared normal morphologically and in particle size. The adnormalities in lipoprotein distribution profiles and composition of the plasma HDL result from metabolic defects that are not understood but may be linked to the genetic defect in bile acid synthesis in CTX. As a consequence, it is probable that the normal functions of the HDL, possibly including modulation of LDL-cholesterol uptake and the removal of excess cholesterol from peripheral tissues, are perturbed significantly in this disease.

  17. Fabrication of highly efficient flexible dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Chang, H., E-mail: f10381@ntut.edu.t [Department of Mechanical Engineering, National Taipei University of Technology, No.1 Sec.3, Chung Hsiao E. Rd., Taipei 10608, Taiwan (China); Chen, T.L. [Department of Industrial Design, National Taipei University of Technology, No.1 Sec.3, Chung Hsiao E. Rd., Taipei 10608, Taiwan (China); Huang, K.D. [Department of Vehicle Engineering, National Taipei University of Technology, No.1 Sec.3, Chung Hsiao E. Rd., Taipei 10608, Taiwan (China); Chien, S.H. [Institute of Chemistry, Academia Sinica, No. 128 Sec.2, Academia Rd., Nankang, Taipei 11529, Taiwan (China); Hung, K.C. [Department of Mechanical Engineering, National Taipei University of Technology, No.1 Sec.3, Chung Hsiao E. Rd., Taipei 10608, Taiwan (China)

    2010-08-15

    The paper studies the fabrication of a flexible dye-sensitized solar cell (DSSC). The photoelectrode substrates are flexible stainless steel sheet with thickness 0.07 mm and titanium (Ti) sheet with thickness 0.25 mm. For the photoelectrode fabrication process, eletrophoresis deposition (EPD) was employed for its merits of low-cost and fast fabrication. With an electric field of 40 V/cm, after undergoing EPD process twice, the TiO{sub 2} nanofilm thickness could be controlled to around 13 {mu}m thick. In addition, to achieve counter electrode, sputtering method was applied to deposit Pt on ITO-PET, resulting in thin films with four different thicknesses of 5, 8, 11 and 14 nm. The experimental results showed that the best colloid solution used in EPD process was a mixture of 100 ml isopropyl alcohol (IPA) and 0.4 g commercial TiO{sub 2} nanoparticles, Degussa P25. The best flatness for a 13 {mu}m thick film could be acquired under an electric field of 40 V/cm. Comparing the photoelectric conversion efficiency values of DSSC assembled by counter electrodes with different Pt thicknesses, the experimental results showed that the best Pt thickness was 11 nm, and the conversion efficiency could reach as high as 2.91%.

  18. High Energy Density Capacitors for Pulsed Power Applications

    Science.gov (United States)

    2009-07-01

    high energy density energy storage capacitors. High efficency capacitors are available with energy densities as high as 3 J/cc for 1000 shots or...GENERAL ATOMICS ENERGY PRODUCTS Engineering Bulletin HIGH ENERGY DENSITY CAPACITORS FOR PULSED POWER APPLICATIONS Fred MacDougall, Joel...00-2009 4. TITLE AND SUBTITLE High Energy Density Capacitors for Pulsed Power Applications 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM

  19. Expancel Foams: Fabrication and Characterization of a New Reduced Density Cellular Material for Structural Applications

    Energy Technology Data Exchange (ETDEWEB)

    L. Whinnery; S. Goods; B. Even

    2000-08-01

    higher density unexpanded powder (approximately 0.5 g/cm{sup 3}) can be produced using this technique. The extremely wide range of accessible densities, ease of processing, relatively inexpensive materials, uniformity of the density, scaleable nature of the process should make this technology highly competitive for a variety of Defense Programs and commercial applications.

  20. Sub-micrometer-thick all-solid-state supercapacitors with high power and energy densities

    Energy Technology Data Exchange (ETDEWEB)

    Meng, Fanhui [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, and School of Chemistry and Chemical Engineering, Shandong University, Jinan 250061 (China); Ding, Yi [Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials, Ministry of Education, and School of Chemistry and Chemical Engineering, Shandong University, Jinan 250061 (China); Shandong Applied Research Center for Gold Technology (Au-SDARC), Yantai 264005 (China)

    2011-09-15

    A sub-micrometer-thick, flexible, all-solid-state supercapacitor is fabricated. Through simultaneous realization of high dispersity of pseudocapacitance materials and quick electrode response, the hybrid nanostructures show enhanced volumetric capacitance and excellent stability, as well as very high power and energy densities. This suggests their potential as next-generation, high-performance energy conversion and storage devices for wearable electronics. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Magnetic fabric and welding processes in high-grade tuffs

    Science.gov (United States)

    Pioli, L.; Ort, M.; Lanza, R.; Rosi, M.

    2003-04-01

    The welding fabric of tuffs is generally quantified through two main parameters: porosity and fiamme aspect ratio. However, these parameters are not useful for high-grade ignimbrites that display features indicating extensive rheomorphic flow, partial to complete obliteration of primary vitroclastic textures, and syn-depositional welding rather than load-related compaction. In this case, a 3D-microstructural characterization of the rock fabric is a fundamental proxy for the assessment of the dynamics and duration of welding processes. We have investigated the relations between magnetic fabric and welding textures in a rhyolitic, high-grade ignimbrite from the Sulcis volcanic District (SW Sardinia, Italy). The ignimbrite is characterized by dense welding throughout its preserved thickness and by regular lateral and vertical variations of welding, devitrification and vesiculation facies. Field and structural data indicate that syn-depositional welding and non-particulate (NP) flow were extensive and continuous during the emplacement of the ignimbrite. Paleomagnetic measurements of AMS, NRM, and AIRM of samples from the tuff indicate that the magnetic fabric is strain-sensitive and it is not significantly affected by post-depositional, static processes such as devitrification and vapor-phase alteration; in particular, magnetic susceptibility of the rock and the welding texture correlate well in terms of shape and orientation of the anisotropy ellipsoid. The direction of the K1 axis is indicative of the flow direction in the site of measurement. The anisotropy degree (P) increases with increasing welding and foliation (F) and lineation (L) are directly related to the strain facies. Onset of welding increased the degree of anisotropy and foliation; a non particulate, laminar flow stage further deformed the fabric stretching it along the flow direction and thus increasing L. The intensity of L is strictly related to the duration and the effect of simple shear (laminar

  2. High density 3D printed microfluidic valves, pumps, and multiplexers.

    Science.gov (United States)

    Gong, Hua; Woolley, Adam T; Nordin, Gregory P

    2016-07-07

    In this paper we demonstrate that 3D printing with a digital light processor stereolithographic (DLP-SLA) 3D printer can be used to create high density microfluidic devices with active components such as valves and pumps. Leveraging our previous work on optical formulation of inexpensive resins (RSC Adv., 2015, 5, 106621), we demonstrate valves with only 10% of the volume of our original 3D printed valves (Biomicrofluidics, 2015, 9, 016501), which were already the smallest that have been reported. Moreover, we show that incorporation of a thermal initiator in the resin formulation along with a post-print bake can dramatically improve the durability of 3D printed valves up to 1 million actuations. Using two valves and a valve-like displacement chamber (DC), we also create compact 3D printed pumps. With 5-phase actuation and a 15 ms phase interval, we obtain pump flow rates as high as 40 μL min(-1). We also characterize maximum pump back pressure (i.e., maximum pressure the pump can work against), maximum flow rate (flow rate when there is zero back pressure), and flow rate as a function of the height of the pump outlet. We further demonstrate combining 5 valves and one DC to create a 3-to-2 multiplexer with integrated pump. In addition to serial multiplexing, we also show that the device can operate as a mixer. Importantly, we illustrate the rapid fabrication and test cycles that 3D printing makes possible by implementing a new multiplexer design to improve mixing, and fabricate and test it within one day.

  3. Nanobiotechnology applications of reconstituted high density lipoprotein.

    Science.gov (United States)

    Ryan, Robert O

    2010-12-01

    High-density lipoprotein (HDL) plays a fundamental role in the Reverse Cholesterol Transport pathway. Prior to maturation, nascent HDL exist as disk-shaped phospholipid bilayers whose perimeter is stabilized by amphipathic apolipoproteins. Methods have been developed to generate reconstituted (rHDL) in vitro and these particles have been used in a variety of novel ways. To differentiate between physiological HDL particles and non-natural rHDL that have been engineered to possess additional components/functions, the term nanodisk (ND) is used. In this review, various applications of ND technology are described, such as their use as miniature membranes for solubilization and characterization of integral membrane proteins in a native like conformation. In other work, ND harboring hydrophobic biomolecules/drugs have been generated and used as transport/delivery vehicles. In vitro and in vivo studies show that drug loaded ND are stable and possess potent biological activity. A third application of ND is their use as a platform for incorporation of amphiphilic chelators of contrast agents, such as gadolinium, used in magnetic resonance imaging. Thus, it is demonstrated that the basic building block of plasma HDL can be repurposed for alternate functions.

  4. Photovoltaic retinal prosthesis with high pixel density

    Science.gov (United States)

    Mathieson, Keith; Loudin, James; Goetz, Georges; Huie, Philip; Wang, Lele; Kamins, Theodore I.; Galambos, Ludwig; Smith, Richard; Harris, James S.; Sher, Alexander; Palanker, Daniel

    2012-06-01

    Retinal degenerative diseases lead to blindness due to loss of the `image capturing' photoreceptors, while neurons in the `image-processing' inner retinal layers are relatively well preserved. Electronic retinal prostheses seek to restore sight by electrically stimulating the surviving neurons. Most implants are powered through inductive coils, requiring complex surgical methods to implant the coil-decoder-cable-array systems that deliver energy to stimulating electrodes via intraocular cables. We present a photovoltaic subretinal prosthesis, in which silicon photodiodes in each pixel receive power and data directly through pulsed near-infrared illumination and electrically stimulate neurons. Stimulation is produced in normal and degenerate rat retinas, with pulse durations of 0.5-4 ms, and threshold peak irradiances of 0.2-10 mW mm-2, two orders of magnitude below the ocular safety limit. Neural responses were elicited by illuminating a single 70 µm bipolar pixel, demonstrating the possibility of a fully integrated photovoltaic retinal prosthesis with high pixel density.

  5. Galaxy interactions II: High density environments

    CERN Document Server

    Alonso, Sol; Padilla, Nelson; Lambas, Diego G

    2011-01-01

    With the aim to assess the role of dense environments in galaxy interactions, properties we present an analysis of close galaxy pairs in groups and clusters, obtained from the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7). We identified pairs that reside in groups by cross-correlating the total galaxy pair catalogue with the SDSS-DR7 group catalogue from Zapata et al. (2009). We classify pair galaxies according to the intensity of interaction. We analysed the effect of high density environments on different classes of galaxy-galaxy interactions and we have also studied the impact of the group global environment on pair galaxies. We find that galaxy pairs are more concentrated towards the group centres with respect to the other group galaxy members, and disturbed pairs show a preference to contain the brightest galaxy in the groups. The color-magnitude relation exhibits significant differences between pair galaxies and the control sample, consisting in color tails with a clear excess of extremely blue and...

  6. Strangeness production in high density baryon matter

    CERN Document Server

    Ganz, R E

    1999-01-01

    Strangeness production in heavy-ion collisions, when compared to proton proton collisions, is potentially a sensitive probe for collective energy deposition and therefore for reaction mechanisms in general. It may therefore provide insight into possible QGP formation in dense nuclear matter. To establish an understanding of the observed yields, a systematic study of high density baryon matter at different beam energies is essential. This might also reveal possible discontinuities in the energy dependence of the reaction mechanism. We present preliminary results for kaon production in Au+Au collisions at beam kinetic energies of 6, 8, and 10.7 GeV/u obtained by the E917 experiment at the AGS (BNL). These measurements complement those carried out by the E866 collaboration at 2, 4, and 10.7 GeV/u with a significantly enlarged data sample. In both experiments a large range of rapidities was covered by taking data at different angular settings of the magnetic spectrometer.

  7. High-density electroencephalography developmental neurophysiological trajectories.

    Science.gov (United States)

    Dan, Bernard; Pelc, Karine; Cebolla, Ana M; Cheron, Guy

    2015-04-01

    Efforts to document early changes in the developing brain have resulted in the construction of increasingly accurate structural images based on magnetic resonance imaging (MRI) in newborn infants. Tractography diagrams obtained through diffusion tensor imaging have focused on white matter microstructure, with particular emphasis on neuronal connectivity at the level of fibre tract systems. Electroencephalography (EEG) provides a complementary approach with more direct access to brain electrical activity. Its temporal resolution is excellent, and its spatial resolution can be enhanced to physiologically relevant levels, through the combination of high-density recordings (e.g. by using 64 channels in newborn infants) and mathematical models (e.g. inverse modelling computation), to identify generators of different oscillation bands and synchrony patterns. The integration of functional and structural topography of the neonatal brain provides insights into typical brain organization, and the deviations seen in particular contexts, for example the effect of hypoxic-ischaemic insult in terms of damage, eventual reorganization, and functional changes. Endophenotypes can then be used for pathophysiological reasoning, management planning, and outcome measurements, and allow a longitudinal approach to individual developmental trajectories. © The Authors. Journal compilation © 2015 Mac Keith Press.

  8. Fabricating high performance lithium-ion batteries using bionanotechnology

    Science.gov (United States)

    Zhang, Xudong; Hou, Yukun; He, Wen; Yang, Guihua; Cui, Jingjie; Liu, Shikun; Song, Xin; Huang, Zhen

    2015-02-01

    Designing, fabricating, and integrating nanomaterials are key to transferring nanoscale science into applicable nanotechnology. Many nanomaterials including amorphous and crystal structures are synthesized via biomineralization in biological systems. Amongst various techniques, bionanotechnology is an effective strategy to manufacture a variety of sophisticated inorganic nanomaterials with precise control over their chemical composition, crystal structure, and shape by means of genetic engineering and natural bioassemblies. This provides opportunities to use renewable natural resources to develop high performance lithium-ion batteries (LIBs). For LIBs, reducing the sizes and dimensions of electrode materials can boost Li+ ion and electron transfer in nanostructured electrodes. Recently, bionanotechnology has attracted great interest as a novel tool and approach, and a number of renewable biotemplate-based nanomaterials have been fabricated and used in LIBs. In this article, recent advances and mechanism studies in using bionanotechnology for high performance LIBs studies are thoroughly reviewed, covering two technical routes: (1) Designing and synthesizing composite cathodes, e.g. LiFePO4/C, Li3V2(PO4)3/C and LiMn2O4/C; and (2) designing and synthesizing composite anodes, e.g. NiO/C, Co3O4/C, MnO/C, α-Fe2O3 and nano-Si. This review will hopefully stimulate more extensive and insightful studies on using bionanotechnology for developing high-performance LIBs.

  9. 14 CFR 93.123 - High density traffic airports.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false High density traffic airports. 93.123... (CONTINUED) AIR TRAFFIC AND GENERAL OPERATING RULES SPECIAL AIR TRAFFIC RULES High Density Traffic Airports § 93.123 High density traffic airports. (a) Each of the following airports is designated as a...

  10. High-altitude atomic nitrogen densities

    Science.gov (United States)

    Oran, E. S.; Strobel, D. F.; Mauersberger, K.

    1978-01-01

    Theoretical calculations of the seasonal and diurnal variations of atomic nitrogen are compared with measurements made by the open source neutral mass spectrometer on the AE-C satellite. With the simultaneous measurements of molecular nitrogen and atomic oxygen densities as input, model calculations of odd nitrogen densities predict the same trends in atomic nitrogen as those observed. From these comparisons it is inferred that horizontal transport significantly reduces the diurnal variation of atomic nitrogen. Estimates are given of the sensitivity of atomic nitrogen densities to variations in the photoelectron flux, the neutral temperatures, and the neutral winds.

  11. Fabrication of 4H-SiC Schottky barrier diodes with high breakdown voltages

    CERN Document Server

    Kum, B H; Shin, M W; Park, J D

    1999-01-01

    This paper discusses the fabrication and the breakdown characteristics of 4H-SiC Schottky barrier diodes (SBDs). Optimal processing conditions for the ohmic contacts were extracted using the transmission-line method (TLM) and were applied to the device fabrication. The Ti/4H-SiC SBDs with Si sub x B sub y passivation showed a maximum reverse breakdown voltage of 268 V with a forward current density as high as 70 mA/cm sup 2 at a forward voltage of 2 V. The breakdown of the Pt. 4H-SiC SBDs without any passivation occurred at near 110 V. It is concluded that the breakdown enhancement in the Ti/4H-SiC SBDs can be attributed to the passivation; otherwise, excess surface charge near the edge of the Schottky contact would lead to electric fields of sufficient magnitude to cause field emission.

  12. Growth and characterization of high current density, high-speed InAs/AlSb resonant tunneling diodes

    Science.gov (United States)

    Soderstrom, J. R.; Brown, E. R.; Parker, C. D.; Mahoney, L. J.; Yao, J. Y.

    1991-01-01

    InAs/AlSb double-barrier resonant tunneling diodes with peak current densities up to 370,000 A/sq cm and high peak-to-valley current ratios of 3.2 at room temperature have been fabricated. The peak current density is well-explained by a stationary-state transport model with the two-band envelope function approximation. The valley current density predicted by this model is less than the experimental value by a factor that is typical of the discrepancy found in other double-barrier structures. It is concluded that threading dislocations are largely inactive in the resonant tunneling process.

  13. An easily fabricated high performance ionic polymer based sensor network

    Science.gov (United States)

    Zhu, Zicai; Wang, Yanjie; Hu, Xiaopin; Sun, Xiaofei; Chang, Longfei; Lu, Pin

    2016-08-01

    Ionic polymer materials can generate an electrical potential from ion migration under an external force. For traditional ionic polymer metal composite sensors, the output voltage is very small (a few millivolts), and the fabrication process is complex and time-consuming. This letter presents an ionic polymer based network of pressure sensors which is easily and quickly constructed, and which can generate high voltage. A 3 × 3 sensor array was prepared by casting Nafion solution directly over copper wires. Under applied pressure, two different levels of voltage response were observed among the nine nodes in the array. For the group producing the higher level, peak voltages reached as high as 25 mV. Computational stress analysis revealed the physical origin of the different responses. High voltages resulting from the stress concentration and asymmetric structure can be further utilized to modify subsequent designs to improve the performance of similar sensors.

  14. Alternative Approaches to High Energy Density Fusion

    Science.gov (United States)

    Hammer, J.

    2016-10-01

    This paper explores selected approaches to High Energy Density (HED) fusion, beginning with discussion of ignition requirements at the National Ignition Facility (NIF). The needed improvements to achieve ignition are closely tied to the ability to concentrate energy in the implosion, manifested in the stagnation pressure, Pstag. The energy that must be assembled in the imploded state to ignite varies roughly as Pstag-2, so among other requirements, there is a premium on reaching higher Pstag to achieve ignition with the available laser energy. The U.S. inertial confinement fusion program (ICF) is pursuing higher Pstag on NIF through improvements to capsule stability and symmetry. One can argue that recent experiments place an approximate upper bound on the ultimate ignition energy requirement. Scaling the implosions consistently in spatial, temporal and energy scales shows that implosions of the demonstrated quality ignite robustly at 9-15 times the current energy of NIF. While lasers are unlikely to reach that bounding energy, it appears that pulsed-power sources could plausibly do so, giving a range of paths forward for ICF depending on success in improving energy concentration. In this paper, I show the scaling arguments then discuss topics from my own involvement in HED fusion. The recent Viewfactor experiments at NIF have shed light on both the observed capsule drive deficit and errors in the detailed modelling of hohlraums. The latter could be important factors in the inability to achieve the needed symmetry and energy concentration. The paper then recounts earlier work in Fast Ignition and the uses of pulsed-power for HED and fusion applications. It concludes with a description of a method for improving pulsed-power driven hohlraums that could potentially provide a factor of 10 in energy at NTF-like drive conditions and reach the energy bound for indirect drive ICF.

  15. Crystalline, highly oriented MOF thin film: the fabrication and application.

    Science.gov (United States)

    Fu, Zhihua; Xu, Gang

    2016-10-24

    The thin film of metal-organic frameworks (MOFs) is a rapidly developing research area which has tremendous potential applications in many fields. One of the major challenges in this area is to fabricate MOF thin film with good crystallinity, high orientation and well-controlled thickness. In order to address this challenge, different appealing approaches have been studied intensively. Among various oriented MOF films, many efforts have also been devoted to developing novel properties and broad applications, such as in gas separator, thermoelectric, storage medium and photovoltaics. As a result, there has been a large demand for fundamental studies that can provide guidance and experimental data for further applications. In this account, we intend to present an overview of current synthetic methods for fabricating oriented crystalline MOF thin film and bring some updated applications. We give our perspective on the background, preparation and applications that led to the developments in this area and discuss the opportunities and challenges of using crystalline, highly oriented MOF thin film.

  16. High current density cathode for electrorefining in molten electrolyte

    Science.gov (United States)

    Li, Shelly X.

    2010-06-29

    A high current density cathode for electrorefining in a molten electrolyte for the continuous production and collection of loose dendritic or powdery deposits. The high current density cathode eliminates the requirement for mechanical scraping and electrochemical stripping of the deposits from the cathode in an anode/cathode module. The high current density cathode comprises a perforated electrical insulated material coating such that the current density is up to 3 A/cm.sup.2.

  17. High-aspect-ratio photoresist processing for fabrication of high resolution and thick micro-windings

    Science.gov (United States)

    Anthony, Ricky; Laforge, Elias; Casey, Declan P.; Rohan, James F.; O'Mathuna, Cian

    2016-10-01

    DC winding losses remain a major roadblock in realizing high efficiency micro-magnetic components (inductors/transformers). This paper reports an optimized photoresist process using negative tone and acrylic based THB-151N (from JSR Micro), to achieve one of the highest aspect ratio (17:1) and resolution (~5 µm) resist patterns for fabrication of thick (~80 µm) micro-winding using UV lithography. The process was optimized to achieve photoresist widths from 5 µm to 20 µm with resist thickness of ~85 µm in a single spin step. Unlike SU-8, this resist can be readily removed and shows a near-vertical (~91°) electroplated Cu side-wall profile. Moreover, the high resolution compared to available resist processes enables a further reduction in the footprint area and can potentially increase the number of winding thereby increasing the inductance density for micro-magnetic components. Resistance measurements of electroplated copper winding of air-core micro-inductors within the standard 0402 size (0.45 mm2 footprint area) suggested a 42% decrease in resistance (273 mΩ-159 mΩ) with the increase in electroplated Cu thickness (from 50 µm to 80 µm). Reduction of the spacings (from 10 µm to 5 µm) enabled further miniaturisation of the device footprint area (from 0.60 mm2 to 0.45 mm2) without significant increase in resistance.

  18. High Density Lipoprotein Metabolism in Man

    Science.gov (United States)

    Blum, Conrad B.; Levy, Robert I.; Eisenberg, Shlomo; Hall, Marshall; Goebel, Robert H.; Berman, Mones

    1977-01-01

    The turnover of 125I-high density lipoprotein (HDL) was examined in a total of 14 studies in eight normal volunteers in an attempt to determine the metabolic relationship between apolipoproteins A-I (apoA-I) and A-II (apoA-II) of HDL and to define further some of the determinants of HDL metabolism. All subjects were first studied under conditions of an isocaloric balanced diet (40% fat, 40% carbohydrate). Four were then studied with an 80% carbohydrate diet, and two were studied while receiving nicotinic acid (1 g three times daily) and ingesting the same isocaloric balanced diet. The decay of autologous 125I-HDL and the appearance of urinary radioactivity were followed for at least 2 wk in each study. ApoA-I and apoA-II were isolated by Sephadex G-200 chromatography from serial plasma samples in each study. The specific activities of these peptides were then measured directly. It was found that the decay of specific activity of apoA-I and apoA-II were parallel to one another in all studies. The mean half-life of the terminal portion of decay was 5.8 days during the studies with a balanced diet. Mathematical modeling of the decay of plasma radioactivity and appearance of urinary radioactivity was most consistent with a two-compartment model. One compartment is within the plasma and exchanges with a nonplasma component. Catabolism occurs from both of these compartments. With a balanced isocaloric diet, the mean synthetic rate for HDL protein was 8.51 mg/kg per day. HDL synthesis was not altered by the high carbohydrate diet and was only slightly decreased by nicotinic acid treatment. These perturbations had effects on HDL catabolic pathways that were reciprocal in many respects. With an 80% carbohydrate diet, the rate of catabolism from the plasma compartment rose by a mean of 39.1%; with nicotinic acid treatment, it fell by 42.2%. Changes in the rate of catabolism from the second compartment were generally opposite those in the rate of catabolism from the plasma

  19. Fabrication of highly conductive carbon nanotube fibers for electrical application

    Science.gov (United States)

    Guo, Fengmei; Li, Can; Wei, Jinquan; Xu, Ruiqiao; Zhang, Zelin; Cui, Xian; Wang, Kunlin; Wu, Dehai

    2015-09-01

    Carbon nanotubes (CNTs) have great potential for use as electrical wires because of their outstanding electrical and mechanical properties. Here, we fabricate lightweight CNT fibers with electrical conductivity as high as that of stainless steel from macroscopic CNT films by drawing them through diamond wire-drawing dies. The entangled CNT bundles are straightened by suffering tension, which improves the alignment of the fibers. The loose fibers are squeezed by the diamond wire-drawing dies, which reduces the intertube space and contact resistance. The CNT fibers prepared by drawing have an electrical conductivity as high as 1.6 × 106 s m-1. The fibers are very stable when kept in the air and under cyclic tensile test. A prototype of CNT motor is demonstrated by replacing the copper wires with the CNT fibers.

  20. High excitation power photoluminescence studies of ultra-low density GaAs quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Sonnenberg, D.; Graf, A.; Paulava, V.; Heyn, Ch.; Hansen, W. [Institut für Angewandte Physik und Zentrum für Mikrostrukturforschung, Universität Hamburg, Jungiusstr. 11, 20355 Hamburg (Germany)

    2013-12-04

    We fabricate GaAs epitaxial quantum dots (QDs) by filling of self-organized nanoholes in AlGaAs. The QDs are fabricated under optimized process conditions and have ultra-low density in the 10{sup 6} cm{sup −2} regime. At low excitation power the optical emission of single QDs exhibit sharp excitonic lines, which are attributed to the recombination of excitonic and biexcitonic states. High excitation power measurements reveal surprisingly broad emission lines from at least six QD shell states.

  1. Highly flexible method for the fabrication of photonic crystal slabs based on the selective formation of porous silicon.

    Science.gov (United States)

    Recio-Sánchez, Gonzalo; Dang, Zhiya; Torres-Costa, Vicente; Breese, Mark Bh; Martín-Palma, Raul-Jose

    2012-08-09

    A novel fabrication method of Si photonic slabs based on the selective formation of porous silicon is reported. Free-standing square lattices of cylindrical air holes embedded in a Si matrix can be achieved by proton beam irradiation followed by electrochemical etching of Si wafers. The photonic band structures of these slabs show several gaps for the two symmetry directions for reflection through the z-plane. The flexibility of the fabrication method for tuning the frequency range of the gaps over the near- and mid-infrared ranges is demonstrated. This tunability can be achieved by simply adjusting the main parameters in the fabrication process such as the proton beam line spacing, proton fluence, or anodization current density. Thus, the reported method opens a promising route towards the fabrication of Si-based photonic slabs, with high flexibility and compatible with the current microelectronics industry.

  2. Research on Properties of Woven Fabrics Treated by High Pressure Water Jet

    Institute of Scientific and Technical Information of China (English)

    黄故

    2001-01-01

    The paper introduces a new technique for the treatment of the woven fabrics. Sprayed by high pressure water jet, the appearance, handle and stiffness of the fabric are improved. Other properties of the high pressure water treated fabrics like drape coefficient, air permeability, tenacity are also presented.

  3. High performance broadband photodetector using fabricated nanowires of bismuth selenide.

    Science.gov (United States)

    Sharma, Alka; Bhattacharyya, Biplab; Srivastava, A K; Senguttuvan, T D; Husale, Sudhir

    2016-01-11

    Recently, very exciting optoelectronic properties of Topological insulators (TIs) such as strong light absorption, photocurrent sensitivity to the polarization of light, layer thickness and size dependent band gap tuning have been demonstrated experimentally. Strong interaction of light with TIs has been shown theoretically along with a proposal for a TIs based broad spectral photodetector having potential to perform at the same level as that of a graphene based photodetector. Here we demonstrate that focused ion beam (FIB) fabricated nanowires of TIs could be used as ultrasensitive visible-NIR nanowire photodetector based on TIs. We have observed efficient electron hole pair generation in the studied Bi2Se3 nanowire under the illumination of visible (532 nm) and IR light (1064 nm). The observed photo-responsivity of ~300 A/W is four orders of magnitude larger than the earlier reported results on this material. Even though the role of 2D surface states responsible for high reponsivity is unclear, the novel and simple micromechanical cleavage (exfoliation) technique for the deposition of Bi2Se3 flakes followed by nanowire fabrication using FIB milling enables the construction and designing of ultrasensitive broad spectral TIs based nanowire photodetector which can be exploited further as a promising material for optoelectronic devices.

  4. High performance broadband photodetector using fabricated nanowires of bismuth selenide

    Science.gov (United States)

    Sharma, Alka; Bhattacharyya, Biplab; Srivastava, A. K.; Senguttuvan, T. D.; Husale, Sudhir

    2016-01-01

    Recently, very exciting optoelectronic properties of Topological insulators (TIs) such as strong light absorption, photocurrent sensitivity to the polarization of light, layer thickness and size dependent band gap tuning have been demonstrated experimentally. Strong interaction of light with TIs has been shown theoretically along with a proposal for a TIs based broad spectral photodetector having potential to perform at the same level as that of a graphene based photodetector. Here we demonstrate that focused ion beam (FIB) fabricated nanowires of TIs could be used as ultrasensitive visible-NIR nanowire photodetector based on TIs. We have observed efficient electron hole pair generation in the studied Bi2Se3 nanowire under the illumination of visible (532 nm) and IR light (1064 nm). The observed photo-responsivity of ~300 A/W is four orders of magnitude larger than the earlier reported results on this material. Even though the role of 2D surface states responsible for high reponsivity is unclear, the novel and simple micromechanical cleavage (exfoliation) technique for the deposition of Bi2Se3 flakes followed by nanowire fabrication using FIB milling enables the construction and designing of ultrasensitive broad spectral TIs based nanowire photodetector which can be exploited further as a promising material for optoelectronic devices.

  5. Variable kernel density estimation in high-dimensional feature spaces

    CSIR Research Space (South Africa)

    Van der Walt, Christiaan M

    2017-02-01

    Full Text Available Estimating the joint probability density function of a dataset is a central task in many machine learning applications. In this work we address the fundamental problem of kernel bandwidth estimation for variable kernel density estimation in high...

  6. Observable to explore high density behaviour of symmetry energy

    CERN Document Server

    Sood, Aman D

    2011-01-01

    We aim to see the sensitivity of collective transverse in-plane flow to symmetry energy at low as well as high densities and also to see the effect of different density dependencies of symmetry energy on the same.

  7. Synchrotron radiation absorber for high density loads

    Science.gov (United States)

    Anashin, V. V.; Kuzminych, V. S.; Trakhtenberg, E. M.; Zholents, A. A.

    1991-10-01

    A design of a special synchrotron radiation absorber for the storage ring VEPP-4M is presented. The density of the synchrotron radiation power on the absorber surface is up to 500 W/mm 2. The absorber is made from a beryllium plate, brazed inside to the copper vacuum chamber, which is intensively water-cooled from outside.

  8. Processing and fabrication of high temperature oxide superconductors

    Science.gov (United States)

    Johnson, Sylvia M.

    1989-07-01

    During the past year, a process for synthesizing superconductor powders by freeze drying was optimized. The objectives were to develop an understanding of the processing of these powders and to fabricate simple shapes from freeze dried powders. A series of powders were synthesized from solutions of barium acetate, copper nitrate, and yttrium nitrate, with pH values of 2.8 to 9.8 and calcined at temperatures from 510 to 908 C. The surface area of these powders were determined by BET AND XRD. Selected powders are being characterized by SEM, DTA, ICP analysis (performed at Stanford University), carbon analysis, and tap density. The highest surface area (in lightly milled powders) of 4.4 sq m/g was achieved with a pH of 4 in a series of experiments in which the Ba and Y solutions were mixed together before the Cu nitrate solution was added, then calcined at 825 C. Surface areas decrease with increasing calcining temperature, however. It appears that calcining at 750 or 850 C gives the best critical temperature, with complete transitions at greater than 90 K. Critical temperature measurements performed at Standford show that the goal of a critical temperature of Tc greater than 90 K and a temperature difference, W, between 10 and 90 percent of transition of less than 2 K, were achieved.

  9. Fabrication of high-transmission microporous membranes by proton beam writing-based molding technique

    Science.gov (United States)

    Wang, Liping; Meyer, Clemens; Guibert, Edouard; Homsy, Alexandra; Whitlow, Harry J.

    2017-08-01

    Porous membranes are widely used as filters in a broad range of micro and nanofluidic applications, e.g. organelle sorters, permeable cell growth substrates, and plasma filtration. Conventional silicon fabrication approaches are not suitable for microporous membranes due to the low mechanical stability of thin film substrates. Other techniques like ion track etching are limited to the production of randomly distributed and randomly orientated pores with non-uniform pore sizes. In this project, we developed a procedure for fabricating high-transmission microporous membranes by proton beam writing (PBW) with a combination of spin-casting and soft lithography. In this approach, focused 2 MeV protons were used to lithographically write patterns consisting of hexagonal arrays of high-density pillars of few μm size in a SU-8 layer coated on a silicon wafer. After development, the pillars were conformably coated with a thin film of poly-para-xylylene (Parylene)-C release agent and spin-coated with polydimethylsiloxane (PDMS). To facilitate demolding, a special technique based on the use of a laser-cut sealing tape ring was developed. This method facilitated the successful delamination of 20-μm thick PDMS membrane with high-density micropores from the mold without rupture or damage.

  10. High-performance field emission of carbon nanotube paste emitters fabricated using graphite nanopowder filler

    Science.gov (United States)

    Sun, Yuning; Yun, Ki Nam; Leti, Guillaume; Lee, Sang Heon; Song, Yoon-Ho; Lee, Cheol Jin

    2017-02-01

    Carbon nanotube (CNT) paste emitters were fabricated using graphite nanopowder filler. The CNT paste emitters consist of CNTs as the emitting material, graphite nanopowder as the filler and a graphite rod as the cathode. Rather than metal or inorganic materials, graphite nanopowder was adapted as a filler material to make the CNT paste emitters. After fabricating the emitters, sandpaper treatment was applied to increase the density of emission sites. The CNT paste emitters showed a high field emission performance, for example a high emission current of 8.5 mA from a cylindrical emitter with a diameter of 0.7 mm (corresponding to a current density of 2.2 A cm-2) and an extremely stable emission current at 1 mA (260 mA cm-2 for 20 h). Interestingly, after a number of electrical arcing events, the emitters still showed a high emission current of 5-8 mA (higher than 1 A cm-2). In addition to the sound electrical and thermal properties of the graphite filler, effective mechanical adhesion of the CNTs onto the graphite cathode induced by the use of the graphite nanopowder filler contributed the excellent field emission properties of the CNT paste emitters.

  11. High-Power-Density Organic Radical Batteries.

    Science.gov (United States)

    Friebe, Christian; Schubert, Ulrich S

    2017-02-01

    Batteries that are based on organic radical compounds possess superior charging times and discharging power capability in comparison to established electrochemical energy-storage technologies. They do not rely on metals and, hence, feature a favorable environmental impact. They furthermore offer the possibility of roll-to-roll processing through the use of different printing techniques, which enables the cost-efficient fabrication of mechanically flexible devices. In this review, organic radical batteries are presented with the focus on the hitherto developed materials and the key properties thereof, e.g., voltage, capacity, and cycle life. Furthermore, basic information, such as significant characteristics, housing approaches, and applied additives, are presented and discussed in the context of organic radical batteries.

  12. High density and high temperature plasmas in Large Helical Device

    Science.gov (United States)

    Komori, Akio

    2010-11-01

    Recently a new confinement regime called Super Dense Core (SDC) mode was discovered in Large Helical Device (LHD). An extremely high density core region with more than ~ 1 × 1021 m-3 is obtained with the formation of an Internal Diffusion Barrier (IDB). The density gradient at the IDB is very high and the particle confinement in the core region is ~ 0.2 s. It is expected, for the future reactor, that the IDB-SDC mode has a possibility to achieve the self-ignition condition with lower temperature than expected before. Conventional approaches to increase the temperature have also been tried in LHD. For the ion heating, the perpendicular neutral beam injection effectively increased the ion temperature up to 5.6 keV with the formation of the internal transport barrier (ITB). In the electron heating experiments with 77 GHz gyrotrons, the highest electron temperature more than 15 keV was achieved, where plasmas are in the neoclassical regime.

  13. High density and high temperature plasmas in Large Helical Device

    Energy Technology Data Exchange (ETDEWEB)

    Komori, Akio, E-mail: komori@LHD.nifs.ac.jp [National Institute for Fusion Science, 322-6 Oroshi, Toki, Gifu 509-5292 (Japan)

    2010-11-01

    Recently a new confinement regime called Super Dense Core (SDC) mode was discovered in Large Helical Device (LHD). An extremely high density core region with more than {approx} 1 x 10{sup 21} m{sup -3} is obtained with the formation of an Internal Diffusion Barrier (IDB). The density gradient at the IDB is very high and the particle confinement in the core region is {approx} 0.2 s. It is expected, for the future reactor, that the IDB-SDC mode has a possibility to achieve the self-ignition condition with lower temperature than expected before. Conventional approaches to increase the temperature have also been tried in LHD. For the ion heating, the perpendicular neutral beam injection effectively increased the ion temperature up to 5.6 keV with the formation of the internal transport barrier (ITB). In the electron heating experiments with 77 GHz gyrotrons, the highest electron temperature more than 15 keV was achieved, where plasmas are in the neoclassical regime.

  14. Highly Compressed Ion Beams for High Energy Density Science

    CERN Document Server

    Friedman, Alex; Briggs, Richard J; Callahan, Debra; Caporaso, George; Celata, C M; Davidson, Ronald C; Faltens, Andy; Grant-Logan, B; Grisham, Larry; Grote, D P; Henestroza, Enrique; Kaganovich, Igor D; Lee, Edward; Lee, Richard; Leitner, Matthaeus; Nelson, Scott D; Olson, Craig; Penn, Gregory; Reginato, Lou; Renk, Tim; Rose, David; Sessler, Andrew M; Staples, John W; Tabak, Max; Thoma, Carsten H; Waldron, William; Welch, Dale; Wurtele, Jonathan; Yu, Simon

    2005-01-01

    The Heavy Ion Fusion Virtual National Laboratory (HIF-VNL) is developing the intense ion beams needed to drive matter to the High Energy Density (HED) regimes required for Inertial Fusion Energy (IFE) and other applications. An interim goal is a facility for Warm Dense Matter (WDM) studies, wherein a target is heated volumetrically without being shocked, so that well-defined states of matter at 1 to 10 eV are generated within a diagnosable region. In the approach we are pursuing, low to medium mass ions with energies just above the Bragg peak are directed onto thin target "foils," which may in fact be foams or "steel wool" with mean densities 1% to 100% of solid. This approach complements that being pursued at GSI, wherein high-energy ion beams deposit a small fraction of their energy in a cylindrical target. We present the requirements for warm dense matter experiments, and describe suitable accelerator concepts, including novel broadband traveling wave pulse-line, drift-tube linac, RF, and single-gap approa...

  15. Improving Robotic Assembly of Planar High Energy Density Targets

    Science.gov (United States)

    Dudt, D.; Carlson, L.; Alexander, N.; Boehm, K.

    2016-10-01

    Increased quantities of planar assemblies for high energy density targets are needed with higher shot rates being implemented at facilities such as the National Ignition Facility and the Matter in Extreme Conditions station of the Linac Coherent Light Source. To meet this growing demand, robotics are used to reduce assembly time. This project studies how machine vision and force feedback systems can be used to improve the quantity and quality of planar target assemblies. Vision-guided robotics can identify and locate parts, reducing laborious manual loading of parts into precision pallets and associated teaching of locations. On-board automated inspection can measure part pickup offsets to correct part drop-off placement into target assemblies. Force feedback systems can detect pickup locations and apply consistent force to produce more uniform glue bond thickness, thus improving the performance of the targets. System designs and performance evaluations will be presented. Work supported in part by the US DOE under the Science Undergraduate Laboratory Internships Program (SULI) and ICF Target Fabrication DE-NA0001808.

  16. Development of Advanced High Uranium Density Fuels for Light Water Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Blanchard, James [Univ. of Wisconsin, Madison, WI (United States); Butt, Darryl [Boise State Univ., ID (United States); Meyer, Mitchell [Idaho National Lab. (INL), Idaho Falls, ID (United States); Xu, Peng [Westinghouse Electric Corporation, Pittsburgh, PA (United States)

    2016-02-15

    This work conducts basic materials research (fabrication, radiation resistance, thermal conductivity, and corrosion response) on U3Si2 and UN, two high uranium density fuel forms that have a high potential for success as advanced light water reactor (LWR) fuels. The outcome of this proposed work will serve as the basis for the development of advance LWR fuels, and utilization of such fuel forms can lead to the optimization of the fuel performance related plant operating limits such as power density, power ramp rate and cycle length.

  17. Sputtered thin films for high density tape recording

    NARCIS (Netherlands)

    Nguyen, L.T.

    This thesis describes the investigation of sputtered thin film media for high density tape recording. As discussed in Chapter 1, to meet the tremendous demand of data storage, the density of recording tape has to be increased continuously. For further increasing the bit density the key factors are:

  18. Sputtered thin films for high density tape recording

    NARCIS (Netherlands)

    Nguyen, L.T.

    2004-01-01

    This thesis describes the investigation of sputtered thin film media for high density tape recording. As discussed in Chapter 1, to meet the tremendous demand of data storage, the density of recording tape has to be increased continuously. For further increasing the bit density the key factors are:

  19. Fabrication of high fidelity, high index three-dimensional photonic crystals using a templating approach

    Science.gov (United States)

    Xu, Yongan

    In this dissertation, we demonstrate the fabrication of high fidelity 3D photonic crystal through polymer template fabrication, backfilling and template removal to obtain high index inversed inorganic photonic crystals (PCs). Along the line, we study the photoresist chemistry to minimize the shrinkage, backfilling strategies for complete infiltration, and template removal at high and low temperatures to minimize crack-formation. Using multibeam interference lithography (MBIL), we fabricate diamond-like photonic structures from commercially available photoresist, SU-8, epoxy functionalized polyhedral oligomeric silsesquioxane (POSS), and narrowly distributed poly(glycidyl methacrylate)s (PGMA). The 3D structure from PGMA shows the lowest shrinkage in the [111] direction, 18%, compared to those fabricated from the SU-8 (41%) and POSS (48%) materials under the same conditions. To fabricate a photonic crystal with large and complete photonic bandgap, it often requires backfilling of high index inorganic materials into a 3D polymer template. We have studied different backfilling methods to create three different types of high index, inorganic 3D photonic crystals. Using SU-8 structures as templates, we systematically study the electrodeposition technique to create inversed 3D titania crystals. We find that 3D SU-8 template is completely infiltrated with titania sol-gel through a two-stage process: a conformal coating of a thin layer of films occurs at the early electrodeposition stage (simulated photonic bandgaps (PBGs) and the SEM observation, further supporting the complete filling by the wet chemistry. Since both PGMA and SU-8 decompose at a temperature above 400°C, leading to the formation of defects and cracks, a highly thermal and mechanical stable template is desired for PC fabrication. We fabricate the 3D POSS structures by MBIL, which can be converted to crack-free silica-like templates over the entire sample area (˜5 mm in diameter) by either thermal

  20. High-density polyethylene-based composites with pressure-treated wood fibers

    OpenAIRE

    Lu Shang; Guangping Han,; Fangzheng Zhu; Jiansheng Ding; Todd Shupe; Qingwen Wang; Qinglin Wu

    2012-01-01

    High-Density Polyethylene (HDPE)-based composites with alkaline copper quaternary (ACQ)- and micronized copper quaternary (MCQ)-treated wood fibers were manufactured through injection molding. The mechanical properties, water absorption, and biological resistance properties of the fabricated composites with different coupling treatments were investigated. Composites with ACQ- and MCQ-treated wood had mechanical properties comparable with those made of untreated wood. The different coupling ag...

  1. Density improvement of Li{sub 2}TiO{sub 3} pebbles fabricated by wet process

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, K.; Kawamura, H. [Japan Atomic Energy Research Inst., Oarai, Ibaraki (Japan). Oarai Research Establishment; Fuchinoue, K.; Sawada, H.; Watarumi, K.

    1998-03-01

    Lithium titanate (Li{sub 2}TiO{sub 3}) has attracted the attention of many researchers from a point of tritium recovery at low temperature, chemical stability, etc.. The application of small Li{sub 2}TiO{sub 3} sphere has been proposed in some designs of fusion blanket. On the other hand, the wet process is most advantageous as the fabrication method of Li{sub 2}TiO{sub 3} pebbles from a point of mass production, and of reprocessing necessary for effective use of resources and reduction of radioactive wastes. In the preliminary fabrication test, density of Li{sub 2}TiO{sub 3} pebbles was about 40%T.D.. Therefore, in this study, density improvement tests and preliminary characterization of Li{sub 2}TiO{sub 3} pebbles by wet process were performed, noting the aging condition and sintering condition in the fabrication process of the gel-spheres. This study yielded Li{sub 2}TiO{sub 3} pebbles in target range of 80-85%T.D.. (author)

  2. High capacity and high density functional conductive polymer and SiO anode for high-energy lithium-ion batteries.

    Science.gov (United States)

    Zhao, Hui; Yuca, Neslihan; Zheng, Ziyan; Fu, Yanbao; Battaglia, Vincent S; Abdelbast, Guerfi; Zaghib, Karim; Liu, Gao

    2015-01-14

    High capacity and high density functional conductive polymer binder/SiO electrodes are fabricated and calendered to various porosities. The effect of calendering is investigated in the reduction of thickness and porosity, as well as the increase of density. SiO particle size remains unchanged after calendering. When compressed to an appropriate density, an improved cycling performance and increased energy density are shown compared to the uncalendered electrode and overcalendered electrode. The calendered electrode has a high-density of ∼1.2 g/cm(3). A high loading electrode with an areal capacity of ∼3.5 mAh/cm(2) at a C/10 rate is achieved using functional conductive polymer binder and simple and effective calendering method.

  3. Fabrication of high thermal conductive Al-cBN ceramic sinters by high temperature high pressure method

    Science.gov (United States)

    Wang, P. F.; Li, Zh. H.; Zhu, Y. M.

    2011-05-01

    Al-cBN ceramic sinters were fabricated by sintering micro-powder mixture of Al and cBN under high temperature and high pressure condition. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), scanning electronic microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) elemental mapping analyses and laser flashing thermal conductivity measurements were performed to investigate the sintering properties and thermal conductivity of the Al-cBN ceramic sinters. XRD analysis revealed these Al-cBN ceramic sinters were composed of a large portion of cBN and of a small portion of AlN, and very little amount of AlB 12 and hBN. Formation of boundary phase resulted in the rapid densification of the sinters, as well as the increase of their relative density with increasing Al additions. The Al-cBN ceramic sinters have a maximum thermal conductivity of about 1.94 W/cm K at room temperature and a much higher value of about 2.04 W/cm K at 200 °C. Their high thermal conductivity over that of AlN-hBN composites promise Al-cBN ceramic sinters favorite candidates as high efficiency heat sink materials for wide band gap semiconductors.

  4. High power densities from high-temperature material interactions

    Energy Technology Data Exchange (ETDEWEB)

    Morris, J.F.

    1981-01-01

    Thermionic energy conversion (TEC) and metallic-fluid heat pipes (MFHPs) offer important and unique advantages in terrestrial and space energy processing. And they are well suited to serve together synergistically. TEC and MFHPs operate through working-fluid vaporization, condensation cycles that accept great thermal power densities at high temperatures. TEC and MFHPs have apparently simple, isolated performance mechanisms that are somewhat similar. And they also have obviously difficult, complected material problems that again are somewhat similar. Intensive investigation reveals that aspects of their operating cycles and material problems tend to merge: high-temperature material effects determine the level and lifetime of performance. Simplified equations verify the preceding statement for TEC and MFHPs. Material properties and interactions exert primary influences on operational effectiveness. And thermophysicochemical stabilities dictate operating temperatures which regulate the thermoemissive currents of TEC and the vaporization flow rates of MFHPs. Major high-temperature material problems of TEC and MFHPs have been solved. These solutions lead to productive, cost-effective applications of current TEC and MFHPs - and point to significant improvements with anticipated technological gains.

  5. SU-C-213-02: Characterizing 3D Printing in the Fabrication of Variable Density Phantoms

    Energy Technology Data Exchange (ETDEWEB)

    Madamesila, J; McGeachy, P; Villarreal-Barajas, J; Khan, R [The University of Calgary, Calgary, AB (Canada)

    2015-06-15

    Purpose: In this work, we present characterization, process flow, quality control and application of 3D fabricated low density phantoms for radiotherapy quality assurance. Methods: A Rostock delta 3D printer using polystyrene filament of diameter 1.75 mm was used to print geometric volumes of 2×2×1 cm{sup 3} of varying densities. The variable densities of 0.1 to 0.75 g/cm {sup 3} were created by modulating the infill. A computed tomography (CT) scan was performed to establish an infill-density calibration curve as well as characterize the quality of the print such as uniformity and the infill pattern. The time required to print these volumes was also recorded. Using the calibration, two low density cones (0.19, 0.52 g/cm{sup 3}) were printed and benchmarked against commercially available phantoms. The dosimetric validation of the low density scaling of Anisotropic Analytical Algorithm (AAA) was performed by using a 0.5 g/cm{sup 3} slab of 10×10×2.4 cm{sup 3} with EBT3 GafChromic film. The gamma analysis at 3%/3mm criteria were compared for the measured and computed dose planes. Results: Analysis of the volume of air pockets in the infill resulted in a reasonable uniformity for densities 0.4 to 0.75 g/cm{sup 3}. Printed phantoms with densities below 0.4 g/cm{sup 3} exhibited a higher ratio of air to polystyrene resulting in large non-uniformity. Compared to the commercial inserts, good agreement was observed only for the printed 0.52 g/cm{sup 3} cone. Dosimetric comparison for a printed low density volume placed in-between layers of solid water resulted in >95% gamma agreement between AAA calculated dose planes and measured EBT3 films for a 6MV 5×5 cm{sup 2} clinical beam. The comparison showed disagreement in the penumbra region. Conclusion: In conclusion, 3D printing technology opens the door to desktop fabrication of variable density phantoms at economical prices in an efficient manner for the quality assurance needs of a small clinic.

  6. High Current Density, Long Life Cathodes for High Power RF Sources

    Energy Technology Data Exchange (ETDEWEB)

    Ives, Robert Lawrence [Calabazas Creek Research,, Inc.; Collins, George [Calabazas Creek Research, Inc.; Falce, Lou [Consultant; Schwartzkopf, Steve [Ron Witherspoon, Inc.; Busbaher, Daniel [Semicon Associates

    2014-01-22

    This program was tasked with improving the quality and expanding applications for Controlled Porosity Reservoir (CPR) cathodes. Calabazas Creek Research, Inc. (CCR) initially developed CPR cathodes on a DOE-funded SBIR program to improve cathodes for magnetron injection guns. Subsequent funding was received from the Defense Advanced Research Projects Agency. The program developed design requirements for implementation of the technology into high current density cathodes for high frequency applications. During Phase I of this program, CCR was awarded the prestigious 2011 R&D100 award for this technology. Subsequently, the technology was presented at numerous technical conferences. A patent was issued for the technology in 2009. These cathodes are now marketed by Semicon Associates, Inc. in Lexington, KY. They are the world’s largest producer of cathodes for vacuum electron devices. During this program, CCR teamed with Semicon Associates, Inc. and Ron Witherspoon, Inc. to improve the fabrication processes and expand applications for the cathodes. Specific fabrications issues included the quality of the wire winding that provides the basic structure and the sintering to bond the wires into a robust, cohesive structure. The program also developed improved techniques for integrating the resulting material into cathodes for electron guns.

  7. Synthesis and characterization of highly-ordered barium-strontium titanate nanotube arrays fabricated by sol-gel method

    Institute of Scientific and Technical Information of China (English)

    Chen Yu; Chen Wei; Guo Feng; Li Mei-Ya; Liu Wei; Zhao Xing-Zhong

    2009-01-01

    Highly uniformed barium-strontium titanate nanotube arrays were fabricated using a porous anodic aluminum oxide template from a barium-strontium titanate sol-gel solution. Electron microscope results showed that nanotubes with uniform length and diameter were obtained. The diameters and lengths of these nanotubes were dependent on the pore diameter and the thickness of the applied anodic aluminum oxide template. High resolution transmission electron microscopy and the selected-area electron diffraction pattern investigations demonstrated the perovskite structure and the polycrystaltine of the fabricated barium-strontium titanate nanotubes. The characterization of the electrical and dielectric properties had also been made. Compared to thin film material,the intrinsic leakage current density is almost the same. Besides,at 30 ℃,the dielectric constant and dielectric loss of the fabricated nanotube is 80 and 0.027 at 1 MHz respectively.

  8. Fabrication of high sensitivity 3D nanoSQUIDs based on a focused ion beam sculpting technique

    Science.gov (United States)

    De Leo, Natascia; Fretto, Matteo; Lacquaniti, Vincenzo; Granata, Carmine; Vettoliere, Antonio

    2016-09-01

    In this paper a nanofabrication process, based on a focused ion beam (FIB) nanosculpting technique, for high sensitivity three-dimensional nanoscale superconducting quantum interference devices (nanoSQUIDs) is reported. The crucial steps of the fabrication process are described, as are some peculiar features of the superconductor-normal metal-insulator-superconductor (SNIS) Josephson junctions, which may useful for applications in cryocooler systems. This fabrication procedure is employed to fabricate sandwich nanojunctions and high sensitivity nanoSQUIDs. Specifically, the superconductive nanosensors have a rectangular loop of 1 × 0.2-0.4 μm2 interrupted by two square Nb/Al-AlO x /Nb SNIS Josephson junctions with side lengths of 0.3 μm. The characterization of a typical nanoSQUID has been carried out and a spectral density of magnetic flux noise as low as 0.8 μΦ0 Hz-1/2 has been measured.

  9. Template fabrication of highly ordered arrays of organic semiconductor nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Heckel, Christian; Ostendorp, Stefan; Lei, Yong; Wilde, Gerhard [Institut fuer Materialphysik, Muenster (Germany)

    2011-07-01

    Porous alumina membrane (PAM) is a widely used template for the fabrication of highly ordered arrays of one-dimensional (1D) nanostructures. The structural parameters of the PAMs are adjustable, including the pore diameter and spacing, and the thickness of the membranes. And thus the structures of the 1D nanomaterials prepared using PAMs can be controlled. On the other hand, the investigation of organic semiconductors opens a new field of applications in computer technology like twistable displays or printing integrated circuits. In the current work, these two technologies are combined by depositing organic n-type semiconductors into the pores of PAMs using different synthesizing processes such as molecular evaporation and solution-phase self-assembly. As a result, highly ordered arrays of organic semiconducting wires are obtained within the pores with a diameter of about 50 nm, which indicates that it is possible to fill the pores with organic materials.The properties of these ''filled'' membranes are characterized by measuring the electrical properties of several nanowires pooled together and also of single nanowires by AFM-based methods.

  10. Heat transfer in high density electronics packaging

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In order to get an insight into the thermal characteristic and to evaluate the thermal reliability of the "System in Packaging"(SIP), a new solution of electronics packaging, a heat transfer model of SIP was developed to predict the heat dissipation capacity and to investigate the effect of different factors on the temperature distribution in the electronics. The affecting parameters under consideration include the thermophysical properties of the substrates, the coefficient of convection heat transfer, the thickness of the chip, and the density of power dissipation. ALGOR, a kind of finite element analysis software,was used to do the model simulation. Based on the sinulation and analysis of the heat conduction and convection resistance, criteria for the thermal design were established and possible measurement for enhancing power dissipation was provided, The results show that the heat transfer model provides a new and effective way to the thermal design and thermal analysis of SIP and to the mechanical analysis for the further investigation of SIP.

  11. High-performance wearable supercapacitors fabricated with surface activated continuous filament graphite fibers

    Science.gov (United States)

    Jia, Dedong; Yu, Xin; Chen, Tinghan; Wang, Shu; Tan, Hua; Liu, Hong; Wang, Zhong Lin; Li, Linlin

    2017-08-01

    Generally, carbon or graphite fibers (GFs) are used as the supporting materials for the preparation of flexible supercapacitors (SCs) by assembling various electrochemically active nanomaterials on them. A facile and rapid electrochemical oxidation method with a voltage of 3 V in a mixed H2SO4-HNO3 solution for 2-15 min is proposed to active continuous filament GFs. Detailed structural characterization, SEM, TEM, XRD, Raman and XPS demonstrate that the GFs-8 (oxidized for 8 min) possessing high specific surface area which provided numerous electrochemical sites and a large number of oxygen-containing functional groups producing pseudocapacitance. Cyclic voltammetric (CV), galvanostatic charge-discharge measurements and electrochemical impedance spectroscopy (EIS) are conducted to test the capacitive of GFs and activated GFs. The capacitance of GFs-8 reaches as high as 570 mF cm-1 at the current density of 1 mA cm-1 in LiCl electrolyte, a 1965-fold enhancement with respect to the pristine GFs (0.29 mF cm-1). The fabricated fiber solid-state supercapacitors (SSCs) provide high energy density of 0.68 mWh cm-3 at the power density 3.3 W cm-3 and have excellent durability with 90% capacitance retention after 10000 cycles. In addition, such fiber SSCs features flexibility and mechanical stability, which may have wide applications in wearable electronic devices.

  12. Influences of urban fabric on pyroclastic density currents at Pompeii (Italy): 2. Temperature of the deposits and hazard implications

    Science.gov (United States)

    Zanella, E.; Gurioli, L.; Pareschi, M. T.; Lanza, R.

    2007-05-01

    During the A.D. 79 eruption of Vesuvius, Italy, the Roman town of Pompeii was covered by 2.5 m of pyroclastic fall pumice and then partially destroyed by pyroclastic density currents (PDCs). Thermal remanent magnetization measurements performed on the lithic and roof tile fragments embedded in the PDC deposits allow us to quantify the variations in the temperature (Tdep) of the deposits within and around Pompeii. These results reveal that the presence of buildings strongly influenced the deposition temperature of the erupted products. The first two currents, which entered Pompeii at a temperature around 300-360°C, show drastic decreases in the Tdep, with minima of 100-140°C, found in the deposits within the town. We interpret these decreases in temperature as being the result of localized interactions between the PDCs and the city structures, which were only able to affect the lower part of the currents. Down flow of Pompeii, the lowermost portion of the PDCs regained its original physical characteristics, emplacing hot deposits once more. The final, dilute PDCs entered a town that was already partially destroyed by the previous currents. These PDCs left thin ash deposits, which mantled the previous ones. The lack of interaction with the urban fabric is indicated by their uniform temperature everywhere. However, the relatively high temperature of the deposits, between 140 and 300°C, indicates that even these distal, thin ash layers, capped by their accretionary lapilli bed, were associated with PDCs that were still hot enough to cause problems for unsheltered people.

  13. MAC Support for High Density Wireless Sensor Networks

    NARCIS (Netherlands)

    Taddia, C.; Meratnia, Nirvana; van Hoesel, L.F.W.; Mazzini, G.; Havinga, Paul J.M.

    Large scale and high density networks of tiny sensor nodes offer promising solutions for event detection and actuating applications. In this paper we address the effect of high density of wireless sensor network performance with a specific MAC protocol, the Lightweight Medium Access Control (LMAC).

  14. High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

    Science.gov (United States)

    Amendt, Peter; Ho, Darwin D.; Jones, Ogden S.

    2015-04-01

    A recent low gas-fill density (0.6 mg/cc 4He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc 4He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth.

  15. High-density carbon ablator ignition path with low-density gas-filled rugby hohlraum

    Energy Technology Data Exchange (ETDEWEB)

    Amendt, Peter; Ho, Darwin D.; Jones, Ogden S. [Lawrence Livermore National Laboratory, Livermore, California 94551 (United States)

    2015-04-15

    A recent low gas-fill density (0.6 mg/cc {sup 4}He) cylindrical hohlraum experiment on the National Ignition Facility has shown high laser-coupling efficiency (>96%), reduced phenomenological laser drive corrections, and improved high-density carbon capsule implosion symmetry [Jones et al., Bull. Am. Phys. Soc. 59(15), 66 (2014)]. In this Letter, an ignition design using a large rugby-shaped hohlraum [Amendt et al., Phys. Plasmas 21, 112703 (2014)] for high energetics efficiency and symmetry control with the same low gas-fill density (0.6 mg/cc {sup 4}He) is developed as a potentially robust platform for demonstrating thermonuclear burn. The companion high-density carbon capsule for this hohlraum design is driven by an adiabat-shaped [Betti et al., Phys. Plasmas 9, 2277 (2002)] 4-shock drive profile for robust high gain (>10) 1-D ignition performance and large margin to 2-D perturbation growth.

  16. Quantum Phenomena in High Energy Density Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Murnane, Margaret [Univ. of Colorado, Boulder, CO (United States); Kapteyn, Henry [Univ. of Colorado, Boulder, CO (United States)

    2017-05-10

    The possibility of implementing efficient (phase matched) HHG upconversion of deep- UV lasers in multiply-ionized plasmas, with potentially unprecedented conversion efficiency is a fascinating prospect. HHG results from the extreme nonlinear response of matter to intense laser light:high harmonics are radiated as a result of a quantum coherent electron recollision process that occurs during laser field ionization of an atom. Under current support from this grant in work published in Science in 2015, we discovered a new regime of bright HHG in highly-ionized plasmas driven by intense UV lasers, that generates bright harmonics to photon energies >280eV

  17. Fabrication of setup for high temperature thermal conductivity measurement

    Science.gov (United States)

    Patel, Ashutosh; Pandey, Sudhir K.

    2017-01-01

    In this work, we report the fabrication of an experimental setup for high temperature thermal conductivity (κ) measurement. It can characterize samples with various dimensions and shapes. Steady state based axial heat flow technique is used for κ measurement. Heat loss is measured using parallel thermal conductance technique. Simple design, lightweight, and small size sample holder is developed by using a thin heater and limited components. Low heat loss value is achieved by using very low thermal conductive insulator block with small cross-sectional area. Power delivered to the heater is measured accurately by using 4-wire technique and for this, the heater is developed with 4 wires. This setup is validated by using Bi0.36Sb1.45Te3, polycrystalline bismuth, gadolinium, and alumina samples. The data obtained for these samples are found to be in good agreement with the reported data. The maximum deviation of 6% in the value κ is observed. This maximum deviation is observed with the gadolinium sample. We also report the thermal conductivity of polycrystalline tellurium from 320 K to 550 K and the nonmonotonous behavior of κ with temperature is observed.

  18. High sensitivity measurements of thermal properties of textile fabrics

    CERN Document Server

    Romeli, D; Esposito, S; Rosace, G; Salesi, G

    2013-01-01

    A new testing apparatus is proposed to measure the thermal properties of fabrics made from polymeric materials. The calibration of the apparatus and the data acquisition procedure are considered in detail in order to measure thermal conductivity, resistance, absorption and diffusivity constants of the tested fabric samples. Differences between dry and wet fabrics have been carefully detected and analyzed. We have developed a new measurement protocol, the "ThermoTex" protocol, which agrees with the UNI EN 31092 standard and entails an accurate quantification of the experimental errors according to a standard statistical analysis, thus allowing a rigorous investigation of the physical behavior of the phenomena involved. As a consequence, our machinery exhibits great potentialities for optimizing the thermal comfort of fabrics, according to the market demand, thanks to the possible development of a predictive phenomenological theory of the effects involved.

  19. The fabrication of high sensitivity gold nanorod H2S gas sensors utilizing the highly uniform anodic aluminum oxide template

    Directory of Open Access Journals (Sweden)

    Chien-Yu Li

    2016-12-01

    Full Text Available Gold nanorod were fabricated using anodic alumina oxide template for H2S gas detection. The nanorod gas sensor exhibits high surface density and contact area, which can increase detection sensitivity. The anodic alumina oxide template contains an array of pores, with a width of 70 nm and a length of 27μm. Au nanorod were obtained through electro-deposition under a pulse bias of −1 V. The resistance of the Au nanorod was recorded upon exposure to various concentrations of H2S. The resistance could be attributed to the high electron affinity between sulfide and Au nanorod. Au–sulfide bonds provide strong bonding, which could alter the conductivity of the sensor. The gas sensor exhibits high sensitivity and short response time for H2S detection at room temperature.

  20. The fabrication of high sensitivity gold nanorod H2S gas sensors utilizing the highly uniform anodic aluminum oxide template

    Science.gov (United States)

    Li, Chien-Yu; Li, Ciao-Yu; Wu, You-Lin; Hsu, Chung-Ping; Lee, Ming-Ching; Houng, Mau-Phon

    2016-12-01

    Gold nanorod were fabricated using anodic alumina oxide template for H2S gas detection. The nanorod gas sensor exhibits high surface density and contact area, which can increase detection sensitivity. The anodic alumina oxide template contains an array of pores, with a width of 70 nm and a length of 27 μ m . Au nanorod were obtained through electro-deposition under a pulse bias of -1 V. The resistance of the Au nanorod was recorded upon exposure to various concentrations of H2S. The resistance could be attributed to the high electron affinity between sulfide and Au nanorod. Au-sulfide bonds provide strong bonding, which could alter the conductivity of the sensor. The gas sensor exhibits high sensitivity and short response time for H2S detection at room temperature.

  1. Application of a high density adsorbent in expanded bed adsorption ...

    African Journals Online (AJOL)

    PRECIOUS

    2010-01-11

    Jan 11, 2010 ... The high density of the adsorbent allowed the EBA to be operated at linear velocity as high as 657 cm/h ... through precipitation and even dialyzed before sample ... In EBA process, upward fluidized stationary phase with.

  2. Fabrication of high-quality submicron Nb/Al-AlOx/Nb tunnel junctions

    Institute of Scientific and Technical Information of China (English)

    Yu Hai-Feng; Cao Wen-Hui; Zhu Xiao-Bo; Yang Hai-Fang; Yu Hong-Wei; Ren Yu-Feng; Gu Chang-Zhi; Chen Geng-Hua; Zhao Shi-Ping

    2008-01-01

    Nb/Al-AlOx/Nb tunnel junctions are often used in the studies of macroscopic quantum phenomena and supercon-ducting qubit applications of the Josepheon devices. In this work, we describe a convenient and reliable process using electron beam lithography for the fabrication of high-quality, submicron-sized Nb/Al-AlOx/Nb Josephson junctions.The technique follows the well-known selective Nb etching process and produces high-quality junctions with Vm=100 mV at 2.3 K for the typical critical current density of 2.2 kA/cm2, which can be adjusted by controlling the oxygen pressure and oxidation time during the formation of the tunnelling barrier. We present the results of the temperature depen-dence of the sub-gap current and in-plane magnetic-field dependence of the critical current, and compare them with the theoretical predictions.

  3. Fabrication of metal/metal functionally graded materials with a high melting point difference

    Institute of Scientific and Technical Information of China (English)

    Zhangjian Zhou; Changchun Ge

    2005-01-01

    Three kinds of full compositional distribution (from 0 to 100wt%W) W/Cu FGMs (functionally graded materials) with high density is fabricated by resistance sintering under ultra-high pressure. Microstructure analysis showed that the good grading composition of all FGMs has been obtained. The sintering mechanism of W is mainly solid state sintering. Thermal shock test in air demonstrated that the grading at the interface between W and Cu is effective for the reduction of thermal stress, but obvious transverse and vertical cracks occur in the pure W layer. The oxidation of the W60Cu40 layer and the W40Cu60 layer is heavier than that of the other layers.

  4. Response of thermosphere density to high-latitude forcing

    Science.gov (United States)

    Yamazaki, Y.; Kosch, M. J.; Vickers, H.; Sutton, E. K.; Ogawa, Y.

    2014-12-01

    Solar wind-magnetospheric disturbances cause enhancements in the energy input to the high-latitude upper atmosphere through particle precipitation and Joule heating. As the upper atmosphere is heated and expanded during geomagnetically disturbed periods, the neutral density in the thermosphere increases at a fixed altitude. Conversely, the thermosphere contracts during the recovery phase of the disturbance, resulting in a decrease of the density. The main objectives of this study are (1) to determine the morphology of the global thermospheric density response to high-latitude forcing, and (2) to determine the recovery speed of the thermosphere density after geomagnetic disturbances. For (1), we use thermospheric density data measured by the Challenging Minisatellite Payload (CHAMP) satellite during 2000-2010. It is demonstrated that the density enhancement during disturbed periods occurs first in the dayside cusp region, and the density at other regions slowly follows it. The reverse process is observed when geomagnetic activity ceases; the density enhancement in the cusp region fades away first, then the global density slowly goes back to the quiet level. For (2), we analyze EISCAT Svalbard radar and Tromso UHF radar data to estimate thermospheric densities during the recovery phase of geomagnetic disturbances. We attempt to determine the time constant for the density recovery both inside and outside the cusp region.

  5. Characterization of high-purity niobium structures fabricated using the electron beam melting process

    Science.gov (United States)

    Terrazas Najera, Cesar Adrian

    Additive Manufacturing (AM) refers to the varied set of technologies utilized for the fabrication of complex 3D components from digital data in a layer-by-layer fashion. The use of these technologies promises to revolutionize the manufacturing industry. The electron beam melting (EBM) process has been utilized for the fabrication of fully dense near-net-shape components from various metallic materials. This process, catalogued as a powder bed fusion technology, consists of the deposition of thin layers (50 - 120microm) of metallic powder particles which are fused by the use of a high energy electron beam and has been commercialized by Swedish company Arcam AB. Superconducting radio frequency (SRF) cavities are key components that are used in linear accelerators and other light sources for studies of elemental physics. Currently, cavity fabrication is done by employing different forming processes including deep-drawing and spinning. In both of the latter techniques, a feedstock high-purity niobium sheet with a thickness ranging from 3-4 mm is mechanically deformed and shaped into the desired geometry. In this manner, half cavities are formed that are later joined by electron beam welding (EBW). The welding step causes variability in the shape of the cavity and can also introduce impurities at the surface of the weld interface. The processing route and the purity of niobium are also of utmost importance since the presence of impurities such as inclusions or defects can be detrimental for the SRF properties of cavities. The focus of this research was the use of the EBM process in the manufacture of high purity niobium parts with potential SRF applications. Reactor grade niobium was plasma atomized and used as the precursor material for fabrication using EBM. An Arcam A2 system was utilized for the fabrication. The system had all internal components of the fabrication chamber replaced and was cleaned to prevent contamination of niobium powder. A mini-vat, developed at

  6. High-Density Three-Dimension Graphene Macroscopic Objects for High-Capacity Removal of Heavy Metal Ions

    Science.gov (United States)

    Li, Weiwei; Gao, Song; Wu, Liqiong; Qiu, Shengqiang; Guo, Yufen; Geng, Xiumei; Chen, Mingliang; Liao, Shutian; Zhu, Chao; Gong, Youpin; Long, Mingsheng; Xu, Jianbao; Wei, Xiangfei; Sun, Mengtao; Liu, Liwei

    2013-01-01

    The chemical vapor deposition (CVD) fabrication of high-density three-dimension graphene macroscopic objects (3D-GMOs) with a relatively low porosity has not yet been realized, although they are desirable for applications in which high mechanical and electrical properties are required. Here, we explore a method to rapidly prepare the high-density 3D-GMOs using nickel chloride hexahydrate (NiCl2·6H2O) as a catalyst precursor by CVD process at atmospheric pressure. Further, the free-standing 3D-GMOs are employed as electrolytic electrodes to remove various heavy metal ions. The robust 3D structure, high conductivity (~12 S/cm) and large specific surface area (~560 m2/g) enable ultra-high electrical adsorption capacities (Cd2+ ~ 434 mg/g, Pb2+ ~ 882 mg/g, Ni2+ ~ 1,683 mg/g, Cu2+ ~ 3,820 mg/g) from aqueous solutions and fast desorption. The current work has significance in the studies of both the fabrication of high-density 3D-GMOs and the removal of heavy metal ions. PMID:23821107

  7. Nuclear Level Density at High Spin and Excitation Energy

    Institute of Scientific and Technical Information of China (English)

    A.N. Behkami; Z. Kargar

    2001-01-01

    The intensive studies of equilibrium processes in heavy-ion reaction have produced a need for information on nuclear level densities at high energies and spins. The Fermi gas level density is often used in investigation of heavy-ion reaction studies. Some papers have claimed that nuclear level densities might deviate substantially from the Fermi gas predications at excitations related to heavy-ion reactions. The formulae of calculation of the nuclear level density based on the theory of superconductivity are presented, special attention is paid to the dependence of the level density on the angular momentum. The spin-dependent nuclear level density is evaluated using the pairing interaction. The resulting level density for an average spin of 52h is evaluated for 155Er and compared with experimental data. Excellent agreement between experiment and theory is obtained.``

  8. Mask-free, vacuum-free fabrication of high-conductivity metallic nanowire by spatially shaped ultrafast laser (Conference Presentation)

    Science.gov (United States)

    Wang, Andong; Li, Xiaowei; Qu, Lianti; Lu, Yongfeng; Jiang, Lan

    2017-03-01

    Metal nanowire fabrication has drawn tremendous attention in recent years due to its wide application in electronics, optoelectronics, and plasmonics. However, conventional laser fabrication technologies are limited by diffraction limit thus the fabrication resolution cannot meet the increasingly high demand of modern devices. Herein we report on a novel method for high-resolution high-quality metal nanowire fabrication by using Hermite-Gaussian beam to ablate metal thin film. The nanowire is formed due to the intensity valley in the center of the laser beam while the surrounding film is ablated. Arbitrary nanowire can be generated on the substrate by dynamically adjusting the orientation of the intensity valley. This method shows obvious advantages compared to conventional methods. First, the minimum nanowire has a width of 60 nm (≍1/13 of the laser wavelength), which is much smaller than the diffraction limit. The high resolution is achieved by combining the ultrashort nature of the femtosecond laser and the low thermal conductivity of the thin film. In addition, the fabricated nanowires have good inside qualities. No inner nanopores and particle intervals are generated inside the nanowire, thus endowing the nanowire with good electronic characteristics: the conductivity of the nanowires is as high as 1.2×107 S/m (≍1/4 of buck material), and the maximum current density is up to 1.66×108 A/m2. Last, the nanowire has a good adhesion to the substrates, which can withstand ultrasonic bath for a long time. These advantages make our method a good approach for high-resolution high-quality nanowire fabrication as a complementary method to conventional lithography methods.

  9. High performance power-configurable preamplifier in a high-density paralleloptical receiver

    Institute of Scientific and Technical Information of China (English)

    Wang Xiaoxia; Wang Zhigong

    2012-01-01

    A power-configurable high performance preamplifier was implemented in standard 180-nm CMOS technology for 12 × 10 Gb/s high-density ultra-high speed parallel optical communication system.With critical limitations on power consumption,area and fabrication cost,the preamplifier achieves high performance,e.g.high bandwidth,high trans-impedance gain,low noise and high stability.A novel feed-forward common gate (FCG)stage is adopted to alleviate contradictions on trans-impedance gain and bandwidth by using a low headroom consuming approach to isolate a large input capacitance and using complex pole peaking techniques to substitute inductors to achieve bandwidth extension.A multi-supply power-configurable scheme was employed to avoid wasteful power caused by a pessimistic estimation of process-voltage-temperature (PVT) variation.Two representative samples provide a trans-impedance gain of 53.9 dBΩ,a 3-dB bandwidth of 6.8 GHz,a power dissipation of 6.26 mW without power-configuration and a trans-impedance gain of 52.1 dBΩ,a 3-dB bandwidth of 8.1 GHz,a power dissipation of 6.35 mW with power-configuration,respectively.The measured average input-referred noise-current spectral density is no more than 28 pA/√Hz.The chip area is only 0.08 × 0.08 mm2.

  10. Breast density estimation from high spectral and spatial resolution MRI.

    Science.gov (United States)

    Li, Hui; Weiss, William A; Medved, Milica; Abe, Hiroyuki; Newstead, Gillian M; Karczmar, Gregory S; Giger, Maryellen L

    2016-10-01

    A three-dimensional breast density estimation method is presented for high spectral and spatial resolution (HiSS) MR imaging. Twenty-two patients were recruited (under an Institutional Review Board--approved Health Insurance Portability and Accountability Act-compliant protocol) for high-risk breast cancer screening. Each patient received standard-of-care clinical digital x-ray mammograms and MR scans, as well as HiSS scans. The algorithm for breast density estimation includes breast mask generating, breast skin removal, and breast percentage density calculation. The inter- and intra-user variabilities of the HiSS-based density estimation were determined using correlation analysis and limits of agreement. Correlation analysis was also performed between the HiSS-based density estimation and radiologists' breast imaging-reporting and data system (BI-RADS) density ratings. A correlation coefficient of 0.91 ([Formula: see text]) was obtained between left and right breast density estimations. An interclass correlation coefficient of 0.99 ([Formula: see text]) indicated high reliability for the inter-user variability of the HiSS-based breast density estimations. A moderate correlation coefficient of 0.55 ([Formula: see text]) was observed between HiSS-based breast density estimations and radiologists' BI-RADS. In summary, an objective density estimation method using HiSS spectral data from breast MRI was developed. The high reproducibility with low inter- and low intra-user variabilities shown in this preliminary study suggest that such a HiSS-based density metric may be potentially beneficial in programs requiring breast density such as in breast cancer risk assessment and monitoring effects of therapy.

  11. Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System.

    Science.gov (United States)

    Yao, Yuhan; Liu, He; Wu, Wei

    2015-07-18

    High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve the solar conversion efficiency of a concentrated photovoltaic system. The proposed system will also lower the solar cell cost in the concentrated photovoltaic system by replacing the expensive tandem solar cells with the cost-effective single junction solar cells. The structures and the parameters of high contrast gratings for the dispersive elements were numerically optimized. The large-area fabrication of high contrast gratings was experimentally demonstrated using nanoimprint lithography and dry etching. The quality of grating material and the performance of the fabricated device were both experimentally characterized. By analyzing the measurement results, the possible side effects from the fabrication processes are discussed and several methods that have the potential to improve the fabrication processes are proposed, which can help to increase the optical efficiency of the fabricated devices.

  12. Research on High Layer Thickness Fabricated of 316L by Selective Laser Melting

    Directory of Open Access Journals (Sweden)

    Shuo Wang

    2017-09-01

    Full Text Available Selective laser melting (SLM is a potential additive manufacturing (AM technology. However, the application of SLM was confined due to low efficiency. To improve efficiency, SLM fabrication with a high layer thickness and fine powder was systematically researched, and the void areas and hollow powders can be reduced by using fine powder. Single-track experiments were used to narrow down process parameter windows. Multi-layer fabrication relative density can be reached 99.99% at the exposure time-point distance-hatch space of 120 μs-40 μm-240 μm. Also, the building rate can be up to 12 mm3/s, which is about 3–10 times higher than the previous studies. Three typical defects were found by studying deeply, including the un-melted defect between the molten pools, the micro-pore defect within the molten pool, and the irregular distribution of the splashing phenomenon. Moreover, the microstructure is mostly equiaxed crystals and a small amount of columnar crystals. The averages of ultimate tensile strength, yield strength, and elongation are 625 MPa, 525 MPa, and 39.9%, respectively. As exposure time increased from 80 μs to 200 μs, the grain size is gradually grown up from 0.98 μm to 2.23 μm, the grain aspect ratio is close to 1, and the tensile properties are shown as a downward trend. The tensile properties of high layer thickness fabricated are not significantly different than those with a coarse-powder layer thickness of low in previous research.

  13. Ultralow-density double-layer silica aerogel fabrication for the intact capture of cosmic dust in low-Earth orbits

    CERN Document Server

    Tabata, Makoto; Yano, Hajime; Imai, Eiichi; Hashimoto, Hirofumi; Yokobori, Shin-ichi; Yamagishi, Akihiko

    2015-01-01

    The fabrication of an ultralow-density hydrophobic silica aerogel for the intact capture cosmic dust during the Tanpopo mission is described. The Tanpopo experiment performed on the International Space Station orbiting the Earth includes the collection of terrestrial and interplanetary dust samples on a silica aerogel capture medium exposed to space for later ground-based biological and chemical analyses. The key to the mission's success is the development of high-performance capture media, and the major challenge is to satisfy the mechanical requirements as a spacecraft payload while maximizing the performance for intact capture. To this end, an ultralow-density (0.01 g cm$^{-3}$) soft aerogel was employed in combination with a relatively robust 0.03 g cm$^{-3}$ aerogel. A procedure was also established for the mass production of double-layer aerogel tiles formed with a 0.01 g cm$^{-3}$ surface layer and a 0.03 g cm$^{-3}$ open-topped, box-shaped base layer, and 60 aerogel tiles were manufactured. The fabric...

  14. 128x128 Ultra-High Density Optical Interconnect Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future NASA programs like Tertiary Planet Finder (TPF) require high-density deformable mirrors with up to 16,000 actuators to enable direct imaging of planets around...

  15. 128x128 Ultra-High Density Optical Interconnect Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Future NASA programs like Tertiary Planet Finder (TPF) require high density deformable mirrors with upto 16,000 actuators to enable direct imaging of planets around...

  16. High current density nanofilament cathodes for microwave amplifiers

    NARCIS (Netherlands)

    Schnell, J-P.; Minoux, E.; Gangloff, L.; Vincent, P.; Legagneux, P.; Dieumegard, D.; David, J.-F.; Peauger, F.; Hudanski, L.; Teo, K.B.K.; Lacerda, R.; Chhowalla, M.; Hasko, D.G.; Ahmed, H.; Amaratunga, G.A.J.; Milne, W.I.; Vila, L.; Dauginet-De Pra, L.; Demoustier-Champagne, S.; Ferain, E.; Legras, R.; Piraux, L.; Gröening, O.; Raedt, H. De; Michielsen, K.

    2004-01-01

    We study high current density nanofilament cathodes for microwave amplifiers. Two different types of aligned nanofilament array have been studied: first, metallic nanowires grown by electrodeposition into nanoporous templates at very low temperature (T

  17. The usefulness of total cholesterol and high density lipoprotein ...

    African Journals Online (AJOL)

    The usefulness of total cholesterol and high density lipoprotein - cholesterol ratio in ... cholesterol and/or highdensity lipoprotein cholesterol/total cholesterol ratios in the interpretation of lipid profile result in clinical practice. ... Article Metrics.

  18. High-Performance Flexible Transparent Electrode with an Embedded Metal Mesh Fabricated by Cost-Effective Solution Process.

    Science.gov (United States)

    Khan, Arshad; Lee, Sangeon; Jang, Taehee; Xiong, Ze; Zhang, Cuiping; Tang, Jinyao; Guo, L Jay; Li, Wen-Di

    2016-06-01

    A new structure of flexible transparent electrodes is reported, featuring a metal mesh fully embedded and mechanically anchored in a flexible substrate, and a cost-effective solution-based fabrication strategy for this new transparent electrode. The embedded nature of the metal-mesh electrodes provides a series of advantages, including surface smoothness that is crucial for device fabrication, mechanical stability under high bending stress, strong adhesion to the substrate with excellent flexibility, and favorable resistance against moisture, oxygen, and chemicals. The novel fabrication process replaces vacuum-based metal deposition with an electrodeposition process and is potentially suitable for high-throughput, large-volume, and low-cost production. In particular, this strategy enables fabrication of a high-aspect-ratio (thickness to linewidth) metal mesh, substantially improving conductivity without considerably sacrificing transparency. Various prototype flexible transparent electrodes are demonstrated with transmittance higher than 90% and sheet resistance below 1 ohm sq(-1) , as well as extremely high figures of merit up to 1.5 × 10(4) , which are among the highest reported values in recent studies. Finally using our embedded metal-mesh electrode, a flexible transparent thin-film heater is demonstrated with a low power density requirement, rapid response time, and a low operating voltage.

  19. Spontaneous magnetization in high-density quark matter

    DEFF Research Database (Denmark)

    Tsue, Yasuhiko; da Providência, João; Providência, Constanca;

    2015-01-01

    It is shown that spontaneous magnetization occurs due to the anomalous magnetic moments of quarks in high-density quark matter under the tensor-type four-point interaction. The spin polarized condensate for each flavor of quark appears at high baryon density, which leads to the spontaneous...... magnetization due to the anomalous magnetic moments of quarks. The implications for the strong magnetic field in compact stars is discussed....

  20. Workshop on extremely high energy density plasmas and their diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Ishii, Shozo (ed.)

    2001-09-01

    Compiled are the papers presented at the workshop on 'Extremely High Energy Density Plasmas and Their Diagnostics' held at National Institute for Fusion Science. The papers cover physics and applications of extremely high-energy density plasmas such as dense z-pinch, plasma focus, and intense pulsed charged beams. Separate abstracts were presented for 7 of the papers in this report. The remaining 25 were considered outside the subject scope of INIS. (author)

  1. Fifth International Conference on High Energy Density Physics

    Energy Technology Data Exchange (ETDEWEB)

    Beg, Farhat

    2017-07-05

    The Fifth International Conference on High Energy Density Physics (ICHED 2015) was held in the Catamaran Hotel in San Diego from August 23-27, 2015. This meeting was the fifth in a series which began in 2008 in conjunction with the April meeting of the American Physical Society (APS). The main goal of this conference has been to bring together researchers from all fields of High Energy Density Science (HEDS) into one, unified meeting.

  2. High-Throughput Fabrication of Resonant Metamaterials with Ultrasmall Coaxial Apertures via Atomic Layer Lithography.

    Science.gov (United States)

    Yoo, Daehan; Nguyen, Ngoc-Cuong; Martin-Moreno, Luis; Mohr, Daniel A; Carretero-Palacios, Sol; Shaver, Jonah; Peraire, Jaime; Ebbesen, Thomas W; Oh, Sang-Hyun

    2016-03-09

    We combine atomic layer lithography and glancing-angle ion polishing to create wafer-scale metamaterials composed of dense arrays of ultrasmall coaxial nanocavities in gold films. This new fabrication scheme makes it possible to shrink the diameter and increase the packing density of 2 nm-gap coaxial resonators, an extreme subwavelength structure first manufactured via atomic layer lithography, both by a factor of 100 with respect to previous studies. We demonstrate that the nonpropagating zeroth-order Fabry-Pérot mode, which possesses slow light-like properties at the cutoff resonance, traps infrared light inside 2 nm gaps (gap volume ∼ λ(3)/10(6)). Notably, the annular gaps cover only 3% or less of the metal surface, while open-area normalized transmission is as high as 1700% at the epsilon-near-zero (ENZ) condition. The resulting energy accumulation alongside extraordinary optical transmission can benefit applications in nonlinear optics, optical trapping, and surface-enhanced spectroscopies. Furthermore, because the resonance wavelength is independent of the cavity length and dramatically red shifts as the gap size is reduced, large-area arrays can be constructed with λresonance ≫ period, making this fabrication method ideal for manufacturing resonant metamaterials.

  3. High-performance energy harvester fabricated with aerosol deposited PMN-PT material

    Science.gov (United States)

    Chen, C. T.; Lin, S. C.; Lin, T. K.; Wu, W. J.

    2016-11-01

    This paper reports a high-performance piezoelectric energy harvester (EH) fabricated with xPb(Mg1/3Nb2/3)-(l-x)PbTiO3 (PMN-PT) by aerosol deposition method. The result indicates that PMN-PT based EH owns 1.8 times output power which is higher than traditional PbZrxTi1- xO3 (PZT) based EH. In order to compare the output performance of EH fabricated with PMN- PT compared with PZT, the similar thickness of PMN-PT and PZT thin film is deposited on stainless steel subtracted. The experimental results show that PZT-based EH had a maximum output power of 4.65 μW with 1.11 Vp-p output voltage excited at 94.4 Hz under 0.5g base excitation, while the PMN-PT based device has a maximum output power of 8.42 μW with 1.49 Vp-p output voltage at a vibration frequency of 94.8 Hz and the same base excitation level. The volumetric power density was 82.95 μW/mm3 and 48.05 μW/mm3 for the device based on PMN- PT and PZT materials, respectively. All the results demonstrate that PMN-PT has better output performance than PZT.

  4. Delta-Doping at Wafer Level for High Throughput, High Yield Fabrication of Silicon Imaging Arrays

    Science.gov (United States)

    Hoenk, Michael E. (Inventor); Nikzad, Shoulch (Inventor); Jones, Todd J. (Inventor); Greer, Frank (Inventor); Carver, Alexander G. (Inventor)

    2014-01-01

    Systems and methods for producing high quantum efficiency silicon devices. A silicon MBE has a preparation chamber that provides for cleaning silicon surfaces using an oxygen plasma to remove impurities and a gaseous (dry) NH3 + NF3 room temperature oxide removal process that leaves the silicon surface hydrogen terminated. Silicon wafers up to 8 inches in diameter have devices that can be fabricated using the cleaning procedures and MBE processing, including delta doping.

  5. High-quality epitaxial graphene devices with low carrier density for resistance metrology

    Science.gov (United States)

    Yang, Yanfei; Huang, Lung-I.; Newell, David; Real, Mariano; Elmquist, Randolph

    2014-03-01

    Epitaxially grown graphene on silicon carbide (SiC) is a promising material for both quantum resistance metrology and wafer-scale electronics. However, monolayers are typically found to be heavily n-doped due to the charge exchange between the graphene and the non-conducting buffer layer beneath that is covalently bonded to the SiC substrate. Carrier densities are usually in the range of 1012 ~ 1013 cm-2, where heavy doping shifts the quantized Hall resistance plateau to high magnetic field values. Various gating methods have been developed to reduce the carrier density, but require lithography processes that increase the probability of contamination that degrades the performance of the devices. Recently, we fabricated high-quality Hall devices on diced semi-insulating SiC wafers, obtaining carrier densities in the range of 1010 ~ 1011 cm-2 and mobility above 104 cm2V-1s-1 without gating. Graphene is grown on the Si face of SiC(0001) substrates and devices are fabricated using a metal layer subtractive process without organic chemical contamination of the graphene. We measure well-developed quantum Hall plateaus with filling factor ν = 2, the fingerprint for monolayer graphene, at magnetic fields below 2 T at liquid helium temperature. A variety of quantum phenomena are observed in these clean, high quality graphene devices. NIST and Georgetown University.

  6. Highly Stretchable 2D Fabrics for Wearable Triboelectric Nanogenerator under Harsh Environments.

    Science.gov (United States)

    Kim, Kyeong Nam; Chun, Jinsung; Kim, Jin Woong; Lee, Keun Young; Park, Jang-Ung; Kim, Sang-Woo; Wang, Zhong Lin; Baik, Jeong Min

    2015-06-23

    Highly stretchable 2D fabrics are prepared by weaving fibers for a fabric-structured triboelectric nanogenerator (FTENG). The fibers mainly consist of Al wires and polydimethylsiloxane (PDMS) tubes with a high-aspect-ratio nanotextured surface with vertically aligned nanowires. The fabrics were produced by interlacing the fibers, which was bonded to a waterproof fabric for all-weather use for fabric-structured triboelectric nanogenerator (FTENG). It showed a stable high-output voltage and current of 40 V and 210 μA, corresponding to an instantaneous power output of 4 mW. The FTENG also exhibits high robustness behavior even after 25% stretching, enough for use in smart clothing applications and other wearable electronics. For wearable applications, the nanogenerator was successfully demonstrated in applications of footstep-driven large-scale power mats during walking and power clothing attached to the elbow.

  7. High-density scintillating glasses for a proton imaging detector

    Science.gov (United States)

    Tillman, I. J.; Dettmann, M. A.; Herrig, V.; Thune, Z. L.; Zieser, A. J.; Michalek, S. F.; Been, M. O.; Martinez-Szewczyk, M. M.; Koster, H. J.; Wilkinson, C. J.; Kielty, M. W.; Jacobsohn, L. G.; Akgun, U.

    2017-06-01

    High-density scintillating glasses are proposed for a novel proton-imaging device that can improve the accuracy of the hadron therapy. High-density scintillating glasses are needed to build a cost effective, compact calorimeter that can be attached to a gantry. This report summarizes the study on Europium, Terbium, and Cerium-doped scintillating glasses that were developed containing heavy elements such as Lanthanum, Gadolinium, and Tungsten. The density of the samples reach up to 5.9 g/cm3, and their 300-600 nm emission overlaps perfectly with the peak cathode sensitivity of the commercial photo detectors. The developed glasses do not require any special quenching and can be poured easily, which makes them a good candidate for production in various geometries. Here, the glass making conditions, preliminary tests on optical and physical properties of these scintillating, high-density, oxide glasses developed for a novel medical imaging application are reported.

  8. High-Density Physical Random Number Generator Using Spin Signals in Multidomain Ferromagnetic Layer

    Directory of Open Access Journals (Sweden)

    Sungwoo Chun

    2015-01-01

    Full Text Available A high-density random number generator (RNG based on spin signals in a multidomain ferromagnetic layer in a magnetic tunnel junction (MTJ is proposed and fabricated. Unlike conventional spin-based RNGs, the proposed method does not require one to control an applied current, leading to a time delay in the system. RNG demonstrations are performed at room temperature. The randomness of the bit sequences generated by the proposed RNG is verified using the FIPS 140-2 statistical test suite provided by the NIST. The test results validate the effectiveness of the proposed RNGs. Our results suggest that we can obtain high-density, ultrafast RNGs if we can achieve high integration on the chip.

  9. Stability of high cell density brewery fermentations during serial repitching.

    Science.gov (United States)

    Verbelen, Pieter J; Dekoninck, Tinne M L; Van Mulders, Sebastiaan E; Saerens, Sofie M G; Delvaux, Filip; Delvaux, Freddy R

    2009-11-01

    The volumetric productivity of the beer fermentation process can be increased by using a higher pitching rate (i.e. higher inoculum size). However, the decreased yeast net growth observed in these high cell density brewery fermentations can adversely affect the physiological stability throughout subsequent yeast generations. Therefore, different O(2) conditions (wort aeration and yeast preoxygenation) were applied to high cell density fermentation and eight generations of fermentations were evaluated together with conventional fermentations. Freshly propagated high cell density populations adapted faster to the fermentative conditions than normal cell density populations. Preoxygenating the yeast was essential for the yeast physiological and beer flavor compound stability of high cell density fermentations during serial repitching. In contrast, the use of non-preoxygenated yeast resulted in inadequate growth which caused (1) insufficient yield of biomass to repitch all eight generations, (2) a 10% decrease in viability, (3) a moderate increase of yeast age, (4) and a dramatic increase of the unwanted flavor compounds acetaldehyde and total diacetyl during the sequence of fermentations. Therefore, to achieve sustainable high cell density fermentations throughout the economical valuable process of serial repitching, adequate yeast growth is essential.

  10. Silicone Adhesives for High Temperature Inflatable Fabrics and Polymer Films Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thin films, elastomeric materials, high temperature fabrics and adhesives that are capable of withstanding thermal extremes (-130oC to 500oC) are highly desirable...

  11. OXIDATION OF DRY HYDROCARBONS AT HIGH-POWER DENSITY ANODES

    Energy Technology Data Exchange (ETDEWEB)

    K.Krist; O. Spaldon-Stewart; R. Remick

    2004-03-01

    This work builds upon discoveries by the University of Pennsylvania and others pertaining to the oxidation of dry hydrocarbon fuels in high temperature solid oxide fuel cells. The work reported here was restricted primarily to dry methane and confirms that YSZ-based cells, having ceria in the anode as a catalyst and copper in the anode as a current collector, can operate on dry methane for extended periods. Thirty-three lab-scale cells of various designs were fabricated and operated under a variety of conditions. The longest-lived cell gave stable performance on dry methane at 800 C for over 305 hours. Only slight carbon deposition was noted at the completion of the test. A corresponding nickel/YSZ-based anode would have lasted for less than an hour under these test conditions (which included open circuit potential measurements) before carbon fouling essentially destroyed the cell. The best performing cell achieved 112 mW/cm{sub 2} on dry methane at 800 C. Several problems were encountered with carbon fouling and declining open circuit voltages in many of the test cells after switching from operation on hydrogen to dry methane. Although not rigorously confirmed by experimentation, the results suggested that air infiltration through less than perfect perimeter seals or pinholes in the electrolytes, or both gave rise to conditions that caused the carbon fouling and OCV decline. Small amounts of air reacting with methane in a partial oxidation reaction could produce carbon monoxide that, in turn, would deposit the carbon. If this mechanism is confirmed, it implies that near perfect hardware is required for extended operation. Some evidence was also found for the formation of electrical shorts, probably from carbon deposits bridging the electrolyte. Work with odorized methane and with methane containing 100-ppm hydrogen sulfide confirmed that copper is stable at 800 C in dry hydrocarbon fuels in the presence of sulfur. In a number of cases, but not exclusively, the

  12. Calibrating apodizer fabrication techniques for high-contrast coronagraphs on segmented and monolithic space telescopes

    Science.gov (United States)

    Sivaramakrishnan, Anand; Greenbaum, Alexandra Z.; Carr, G. Lawrence; Smith, Randy J.; Xi, Xiaoxiang; Zimmerman, Neil T.

    2013-09-01

    High contrast imaging can use pupil apodizers to suppress diffracted starlight from a bright source in order to observe its environs. Metallic half-tone dot transmissive apodizers were developed for the Gemini Planet Imager (GPI) and ESO SPHERE coronagraphs for use in the near-IR. Dot sizes on the scale of the wavelength of the light often result in unexpected variations in the optical transmission vs. superficial dot density relation. We measured 5 and 10 micron half-tone microdot screens' transmissions between 550 -1050 nm to prepare to fabricate apodizations that mitigate diffraction by segments gaps and spiders on future large space telescopes. We utilized slow test beams (f/40, f/80) to estimate the on-axis (far-field, or zero-order) transmission of test patches using a Fourier Transform Spectrograph on Beamline U10B at Brookhaven National Laboratory's National Synchrotron Light Source (BNL NSLS). We also modified our previous GPI IR characterization hardware and methods for this experiment. Our measurements show an internal consistency of 0.1% in transmission, a factor of 5 better than our near-IR GPI work on the NSLS U4IR beamline. The systematics of the set-up appeared to limit the absolute calibration for our f/40 data on the 50-patch, maximum Optical Density 3 (OD3), sample. Credible measurements of transmissions down to about 3% transmission were achieved for this sample. Future work on apodizers for obstructed and segmented primary mirror coronagraphs will require configurations that mimic the intended diffractive configurations closely in order to tune apodizer fabrication to any particular application, and measure chromatic effects in representative diffractive regimes. Further experimental refinements are needed to measure the densest test patches which possess transmissions less than a few percent. The new NSLS-II should provide much greater spectral stability of its synchrotron beam, which will improve measurement accuracy and reduce systematics.

  13. High-irradiance effects in femosecond laser fabrication

    Directory of Open Access Journals (Sweden)

    Buividas Ričardas

    2013-11-01

    Full Text Available Laser micro-fabrication and micro-structuring of materials is usually carried out at the conditions close to the dielectric breakdown. Interplay between multi-photon and avalanche generation of electrons and thermal relaxation become critically important at those conditions in photo-polymerization, waveguide writing in glasses and for creation of new materials at the focal region. Relevant mechanisms of structuring are reviewed and discussed.

  14. Fabrication and characterization of high power dual chamber E. coli microbial fuel cell

    Science.gov (United States)

    Lalitha Priya, R.; Ramachandran, T.; Suneesh, P. V.

    2016-09-01

    This work reports the fabrication of a dual chamber microbial fuel cell with E. coli modified graphite as the anode and lead dioxide cathode. At the optimized operating conditions, the cell provided 778 mV open circuit potential, 3.47 mA m-2 of current density and 1660 mW m-2 power density. Morphology of the of E. coli biofilm on the electrode was analysed using AFM and the electrochemical characterization of the fuel cell was carried out using electrochemical impedance spectroscopy (EIS) and polarization curves. The composition of the anode and the time duration for E. coli biofilm formation were varied to obtain maximum power density. The MFC fabricated in this study was found to have improved power density in comparison with other reported fuel cells.

  15. Beyond high-density lipoprotein cholesterol levels evaluating high-density lipoprotein function as influenced by novel therapeutic approaches

    National Research Council Canada - National Science Library

    deGoma, Emil M; deGoma, Rolando L; Rader, Daniel J

    2008-01-01

    A number of therapeutic strategies targeting high-density lipoprotein (HDL) cholesterol and reverse cholesterol transport are being developed to halt the progression of atherosclerosis or even induce regression...

  16. Comparison of low density and high density pedicle screw instrumentation in Lenke 1 adolescent idiopathic scoliosis.

    Science.gov (United States)

    Shen, Mingkui; Jiang, Honghui; Luo, Ming; Wang, Wengang; Li, Ning; Wang, Lulu; Xia, Lei

    2017-08-02

    The correlation between implant density and deformity correction has not yet led to a precise conclusion in adolescent idiopathic scoliosis (AIS). The aim of this study was to evaluate the effects of low density (LD) and high density (HD) pedicle screw instrumentation in terms of the clinical, radiological and Scoliosis Research Society (SRS)-22 outcomes in Lenke 1 AIS. We retrospectively reviewed 62 consecutive Lenke 1 AIS patients who underwent posterior spinal arthrodesis using all-pedicle screw instrumentation with a minimum follow-up of 24 months. The implant density was defined as the number of screws per spinal level fused. Patients were then divided into two groups according to the average implant density for the entire study. The LD group (n = 28) had fewer than 1.61 screws per level, while the HD group (n = 34) had more than 1.61 screws per level. The radiographs were analysed preoperatively, postoperatively and at final follow-up. The perioperative and SRS-22 outcomes were also assessed. Independent sample t tests were used between the two groups. Comparisons between the two groups showed no significant differences in the correction of the main thoracic curve and thoracic kyphosis, blood transfusion, hospital stay, and SRS-22 scores. Compared with the HD group, there was a decreased operating time (278.4 vs. 331.0 min, p = 0.004) and decreased blood loss (823.6 vs. 1010.9 ml, p = 0.048), pedicle screws needed (15.1 vs. 19.6, p density and high density pedicle screw instrumentation achieved satisfactory deformity correction in Lenke 1 AIS patients. However, the operating time and blood loss were reduced, and the implant costs were decreased with the use of low screw density constructs.

  17. High-performance rectifiers fabricated on a flexible substrate

    Science.gov (United States)

    Etor, David; Dodd, Linzi E.; Wood, David; Balocco, Claudio

    2016-11-01

    We report on the fabrication and testing of metal-insulator-metal (MIM) diodes on a flexible substrate where the thin insulating layer self-assembles as a monolayer sandwiched between the two metal electrodes. The current-voltage characteristic has a strong asymmetry and non-linearity at zero-bias. The diodes have a typical zero-bias resistance of 80 kΩ, a zero-bias curvature coefficient of 5.5 V-1, and a voltage responsivity of 3.1 kV/W at a frequency of 1 GHz. The fabrication yield was over 90%, and an encapsulation method to prevent MIM junction degradation has also been developed. The diodes show no significant degradation in performance when the substrate is stressed in a one-off bending experiment, although extensive testing does produce some loss in quality. The fabrication process is simple, cost effective, and carried out at low temperature, opening up the possibility of roll-to-roll volume manufacturing of fast MIM diodes.

  18. High dislocation density of tin induced by electric current

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Yi-Han; Liang, Chien-Lung; Lin, Kwang-Lung, E-mail: matkllin@mail.ncku.edu.tw [Department of Material Science and Engineering, National Cheng Kung University, Tainan 70101, Taiwan, R. O. C (China); Wu, Albert T. [Department of Chemical and Material Engineering, National Central University, Jhongli 32001, Taiwan, R. O. C (China)

    2015-12-15

    A dislocation density of as high as 10{sup 17} /m{sup 2} in a tin strip, as revealed by high resolution transmission electron microscope, was induced by current stressing at 6.5 x 10{sup 3} A/ cm{sup 2}. The dislocations exist in terms of dislocation line, dislocation loop, and dislocation aggregates. Electron Backscattered Diffraction images reflect that the high dislocation density induced the formation of low deflection angle subgrains, high deflection angle Widmanstätten grains, and recrystallization. The recrystallization gave rise to grain refining.

  19. Design and Fabrication of Nanoscale IDTs Using Electron Beam Technology for High-Frequency SAW Devices

    Directory of Open Access Journals (Sweden)

    Wei-Che Shih

    2014-01-01

    Full Text Available High-frequency Rayleigh-mode surface acoustic wave (SAW devices were fabricated for 4G mobile telecommunications. The RF magnetron sputtering method was adopted to grow piezoelectric aluminum nitride (AlN thin films on the Si3N4/Si substrates. The influence of sputtering parameters on the crystalline characteristics of AlN thin films was investigated. The interdigital transducer electrodes (IDTs of aluminum (Al were then fabricated onto the AlN surfaces by using the electron beam (e-beam direct write lithography method to form the Al/AlN/Si3N4/Si structured SAW devices. The Al electrodes were adopted owing to its low resistivity, low cost, and low density of the material. For 4G applications in mobile telecommunications, the line widths of 937 nm, 750 nm, 562 nm, and 375 nm of IDTs were designed. Preferred orientation and crystalline properties of AlN thin films were determined by X-ray diffraction using a Siemens XRD-8 with CuKα radiation. Additionally, the cross-sectional images of AlN thin films were obtained by scanning electron microscope. Finally, the frequency responses of high-frequency SAW devices were measured using the E5071C network analyzer. The center frequencies of the high-frequency Rayleigh-mode SAW devices of 1.36 GHz, 1.81 GHz, 2.37 GHz, and 3.74 GHz are obtained. This study demonstrates that the proposed processing method significantly contributes to high-frequency SAW devices for wireless communications.

  20. Tuning Phase Composition of Polymer Nanocomposites toward High Energy Density and High Discharge Efficiency by Nonequilibrium Processing.

    Science.gov (United States)

    Jiang, Jianyong; Zhang, Xin; Dan, Zhenkang; Ma, Jing; Lin, Yuanhua; Li, Ming; Nan, Ce-Wen; Shen, Yang

    2017-09-06

    Polymer nanocomposite dielectrics with high energy density and low loss are major enablers for a number of applications in modern electronic and electrical industry. Conventional fabrication of nanocomposites by solution routes involves equilibrium process, which is slow and results in structural imperfections, hence high leakage current and compromised reliability of the nanocomposites. We propose and demonstrate that a nonequilibrium process, which synergistically integrates electrospinning, hot-pressing and thermal quenching, is capable of yielding nanocomposites of very high quality. In the nonequilibrium nanocomposites of poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) and BaTiO3 nanoparticles (BTO_nps), an ultrahigh Weibull modulus β of ∼30 is achieved, which is comparable to the quality of the bench-mark biaxially oriented polypropylene (BOPP) fabricated with melt-extrusion process by much more sophisticated and expensive industrial apparatus. Favorable phase composition and small crystalline size are also induced by the nonequilibrium process, which leads to concomitant enhancement of electric displacement and breakdown strength of the nanocomposite hence a high energy density of ∼21 J/cm(3). Study on the polarization behavior and phase transformation at high electric field indicates that BTO_nps could facilitate the phase transformation from α- to β-polymorph at low electric field.

  1. Electrochemically fabricated polypyrrole-cobalt-oxygen coordination complex as high-performance lithium-storage materials.

    Science.gov (United States)

    Guo, Bingkun; Kong, Qingyu; Zhu, Ying; Mao, Ya; Wang, Zhaoxiang; Wan, Meixiang; Chen, Liquan

    2011-12-23

    Current lithium-ion battery (LIB) technologies are all based on inorganic electrode materials, though organic materials have been used as electrodes for years. Disadvantages such as limited thermal stability and low specific capacity hinder their applications. On the other hand, the transition metal oxides that provide high lithium-storage capacity by way of electrochemical conversion reaction suffer from poor cycling stability. Here we report a novel high-performance, organic, lithium-storage material, a polypyrrole-cobalt-oxygen (PPy-Co-O) coordination complex, with high lithium-storage capacity and excellent cycling stability. Extended X-ray absorption fine structure and Raman spectroscopy and other physical and electrochemical characterizations demonstrate that this coordination complex can be electrochemically fabricated by cycling PPy-coated Co(3)O(4) between 0.0 V and 3.0 V versus Li(+)/Li. Density functional theory (DFT) calculations indicate that each cobalt atom coordinates with two nitrogen atoms within the PPy-Co coordination layer and the layers are connected with oxygen atoms between them. Coordination weakens the C-H bonds on PPy and makes the complex a novel lithium-storage material with high capacity and high cycling stability.

  2. Noise reduction in muon tomography for detecting high density objects

    CERN Document Server

    Benettoni, M; Bonomi, G; Calvagno, G; Calvini, P; Checchia, P; Cortelazzo, G; Cossutta, L; Donzella, A; Furlan, M; Gonella, F; Pegoraro, M; Garola, A Rigoni; Ronchese, P; Squarcia, S; Subieta, M; Vanini, S; Viesti, G; Zanuttigh, P; Zenoni, A; Zumerle, G

    2013-01-01

    The muon tomography technique, based on multiple Coulomb scattering of cosmic ray muons, has been proposed as a tool to detect the presence of high density objects inside closed volumes. A new and innovative method is presented in this paper to handle the density fluctuations (noise) of reconstructed images, that are a known problem of this technique. The effectiveness of our method is evaluated using experimental data obtained with a muon tomography prototype located at Legnaro National Laboratories (LNL) of the Istituto Nazionale di Fisica Nucleare (INFN). The results reported in this paper, obtained with real cosmic ray data, show that with appropriate image filtering and muon momentum classification, the muon tomography technique can detect in short times high density materials, such as lead, when surrounded by light or medium density material. A comparison with algorithms published in literature is also presented.

  3. Noise reduction in muon tomography for detecting high density objects

    Science.gov (United States)

    Benettoni, M.; Bettella, G.; Bonomi, G.; Calvagno, G.; Calvini, P.; Checchia, P.; Cortelazzo, G.; Cossutta, L.; Donzella, A.; Furlan, M.; Gonella, F.; Pegoraro, M.; Rigoni Garola, A.; Ronchese, P.; Squarcia, S.; Subieta, M.; Vanini, S.; Viesti, G.; Zanuttigh, P.; Zenoni, A.; Zumerle, G.

    2013-12-01

    The muon tomography technique, based on multiple Coulomb scattering of cosmic ray muons, has been proposed as a tool to detect the presence of high density objects inside closed volumes. In this paper a new and innovative method is presented to handle the density fluctuations (noise) of reconstructed images, a well known problem of this technique. The effectiveness of our method is evaluated using experimental data obtained with a muon tomography prototype located at the Legnaro National Laboratories (LNL) of the Istituto Nazionale di Fisica Nucleare (INFN). The results reported in this paper, obtained with real cosmic ray data, show that with appropriate image filtering and muon momentum classification, the muon tomography technique can detect high density materials, such as lead, albeit surrounded by light or medium density material, in short times. A comparison with algorithms published in literature is also presented.

  4. Thickness dependence of critical current density in MgB{sub 2} films fabricated by ex situ annealing of CVD-grown B films in Mg vapor

    Energy Technology Data Exchange (ETDEWEB)

    Hanna, Mina; Salama, Kamel [Department of Mechanical Engineering and Texas Center for Superconductivity, University of Houston, Houston, TX 77204 (United States); Wang, Shufang; Xi, X X [Department of Physics, Pennsylvania State University, University Park, PA 16801 (United States); Redwing, Joan M [Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16801 (United States)], E-mail: ksalama@uh.edu

    2009-01-15

    A study was performed to examine the J{sub c} behavior as a function of thickness in MgB{sub 2} films fabricated by ex situ annealing at 840 deg. C of boron films, grown by chemical vapor deposition, in Mg vapor. The film thicknesses range between 300 nm and 10 {mu}m. The values of J{sub c} range from 1.2 x 10{sup 7} A cm{sup -2} for 300 nm to 1.9 x 10{sup 5} A cm{sup -2} for 10 {mu}m film thicknesses at 20 K and self-field. The study shows that the critical current density (J{sub c}) in MgB{sub 2} films decreases with increasing film thickness, similar to that observed in YBCO-coated conductors. Moreover, our study shows that critical current (I{sub c}) reaches its maximum value of 728 A cm{sup -1} width at {approx}1 {mu}m thick MgB{sub 2} films at 20 K and self-field, which is, interestingly, the same thickness of pulsed-laser-deposited YBCO-coated conductors at which I{sub c} reaches its maximum value. The high J{sub c} values carried by our films show that the ex situ fabrication method can produce high quality MgB{sub 2} films at low processing temperatures, which is promising for RF cavity applications and coated-conductor wires and tapes.

  5. High energy density interpenetrating networks from ionic networks and silicone

    DEFF Research Database (Denmark)

    Yu, Liyun; Madsen, Frederikke Bahrt; Hvilsted, Søren

    2015-01-01

    The energy density of dielectric elastomers (DEs) is sought increased for better exploitation of the DE technology since an increased energy density means that the driving voltage for a certain strain can be lowered in actuation mode or alternatively that more energy can be harvested in generator...... mode. One way to increase the energy density is to increase dielectric permittivity of the elastomer. A novel silicone elastomer system with high dielectric permittivity was prepared through the development of interpenetrating networks from ionically assembled silicone polymers and covalently...

  6. Solid Oxide Electrolysis Cells: Degradation at High Current Densities

    DEFF Research Database (Denmark)

    Knibbe, Ruth; Traulsen, Marie Lund; Hauch, Anne;

    2010-01-01

    The degradation of Ni/yttria-stabilized zirconia (YSZ)-based solid oxide electrolysis cells operated at high current densities was studied. The degradation was examined at 850°C, at current densities of −1.0, −1.5, and −2.0 A/cm2, with a 50:50 (H2O:H2) gas supplied to the Ni/YSZ hydrogen electrode...

  7. BCS Theory of Hadronic Matter at High Densities

    DEFF Research Database (Denmark)

    Bohr, Henrik; Panda, Prafulla K.; Providencia, Constanca

    2012-01-01

    The equilibrium between the so-called 2SC and CFL phases of strange quark matter at high densities is investigated in the framework of a simple schematic model of the NJL type. Equal densities are assumed for quarks u, d and s. The 2SC phase is here described by a color-flavor symmetric state...... than is usual in NJL type models. This should be adequate if the relevant chemical potential does not exceed 0.6 GeV....

  8. Batch-processed GdBCO-Ag bulk superconductors fabricated using generic seeds with high trapped fields

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Y., E-mail: ys206@cam.ac.u [Superconductivity Group, Engineering Department, University of Cambridge, CB2 1PZ (United Kingdom); Hari Babu, N. [Brunel Centre for Advanced Solidification Technology (BCAST), Brunel University, West London UB8 3PH (United Kingdom); Iida, K. [Superconducting Group, IFW-Dresden Helmoholtz Str. 20, D-01069 Dresden (Germany); Yeoh, W.K. [Australian Key Centre for Microscopy and Microanalysis, University of Sydney, NSW 2006 (Australia); Dennis, A.R.; Pathak, S.K.; Cardwell, D.A. [Superconductivity Group, Engineering Department, University of Cambridge, CB2 1PZ (United Kingdom)

    2010-09-01

    Large, single grains of Y-Ba-Cu-O (YBCO) have been batch-processed to date by the top seeded melt growth (TSMG) process using NdBCO or SmBCO seed crystals. It has proved difficult, however, to economically batch-process light rare earth (LRE) LRE-Ba-Cu-O bulk high temperature superconductors, which have higher critical current densities and irreversibility fields than YBCO, and therefore greater potential for high field engineering applications. In this paper, we report a novel batch-process based on a cheap, readily available generic seed crystal, developed recently at Cambridge, and a TSMG melt processing technique based on cold seeding in air for the batch fabrication of Gd-Ba-Cu-O-Ag single grains. The superconducting properties of the (LRE)BCO single grains fabricated by this process are, in all respects, equivalent to those processed more conventionally in a reduced oxygen atmosphere.

  9. High-density EMG e-textile systems for the control of active prostheses

    DEFF Research Database (Denmark)

    Farina, Dario; Lorrain, Thomas; Negro, Francesco

    2010-01-01

    Myoelectric control of active prostheses requires electrode systems that are easy to apply for daily repositioning of the electrodes by the user. In this study we propose the use of Smart Fabric and Interactive Textile (SFIT) systems as an alternative solution for recording high-density EMG signals...... classified with linear discriminant analysis. The average classification accuracy for the nine tasks was 89.1 1.9 %. These results show that SFIT systems can be used as an effective way for muscle-machine interfacing....

  10. Laser drilling of vias in dielectric for high density multilayer LSHI thick film circuits

    Science.gov (United States)

    Cocca, T.; Dakesian, S.

    1977-01-01

    A design analysis of a high density multilevel thick film digital microcircuit used for large scale integration is presented. The circuit employs 4 mil lines, 4 mil spaces and requires 4 mil diameter vias. Present screened and fired thick film technology is limited on a production basis to 16 mil square vias. A process whereby 4 mil diameter vias can be fabricated in production using laser technology was described along with a process to produce 4 mil diameter vias for conductor patterns which have 4 mil lines and 4 mil spacings.

  11. Transition metal sulfides grown on graphene fibers for wearable asymmetric supercapacitors with high volumetric capacitance and high energy density

    Science.gov (United States)

    Cai, Weihua; Lai, Ting; Lai, Jianwei; Xie, Haoting; Ouyang, Liuzhang; Ye, Jianshan; Yu, Chengzhong

    2016-06-01

    Fiber shaped supercapacitors are promising candidates for wearable electronics because they are flexible and light-weight. However, a critical challenge of the widespread application of these energy storage devices is their low cell voltages and low energy densities, resulting in limited run-time of the electronics. Here, we demonstrate a 1.5 V high cell voltage and high volumetric energy density asymmetric fiber supercapacitor in aqueous electrolyte. The lightweight (0.24 g cm‑3), highly conductive (39 S cm‑1), and mechanically robust (221 MPa) graphene fibers were firstly fabricated and then coated by NiCo2S4 nanoparticles (GF/NiCo2S4) via the solvothermal deposition method. The GF/NiCo2S4 display high volumetric capacitance up to 388 F cm‑3 at 2 mV s‑1 in a three-electrode cell and 300 F cm‑3 at 175.7 mA cm‑3 (568 mF cm‑2 at 0.5 mA cm‑2) in a two-electrode cell. The electrochemical characterizations show 1000% higher capacitance of the GF/NiCo2S4 as compared to that of neat graphene fibers. The fabricated device achieves high energy density up to 12.3 mWh cm‑3 with a maximum power density of 1600 mW cm‑3, outperforming the thin-film lithium battery. Therefore, these supercapacitors are promising for the next generation flexible and wearable electronic devices.

  12. Transition metal sulfides grown on graphene fibers for wearable asymmetric supercapacitors with high volumetric capacitance and high energy density.

    Science.gov (United States)

    Cai, Weihua; Lai, Ting; Lai, Jianwei; Xie, Haoting; Ouyang, Liuzhang; Ye, Jianshan; Yu, Chengzhong

    2016-06-01

    Fiber shaped supercapacitors are promising candidates for wearable electronics because they are flexible and light-weight. However, a critical challenge of the widespread application of these energy storage devices is their low cell voltages and low energy densities, resulting in limited run-time of the electronics. Here, we demonstrate a 1.5 V high cell voltage and high volumetric energy density asymmetric fiber supercapacitor in aqueous electrolyte. The lightweight (0.24 g cm(-3)), highly conductive (39 S cm(-1)), and mechanically robust (221 MPa) graphene fibers were firstly fabricated and then coated by NiCo2S4 nanoparticles (GF/NiCo2S4) via the solvothermal deposition method. The GF/NiCo2S4 display high volumetric capacitance up to 388 F cm(-3) at 2 mV s(-1) in a three-electrode cell and 300 F cm(-3) at 175.7 mA cm(-3) (568 mF cm(-2) at 0.5 mA cm(-2)) in a two-electrode cell. The electrochemical characterizations show 1000% higher capacitance of the GF/NiCo2S4 as compared to that of neat graphene fibers. The fabricated device achieves high energy density up to 12.3 mWh cm(-3) with a maximum power density of 1600 mW cm(-3), outperforming the thin-film lithium battery. Therefore, these supercapacitors are promising for the next generation flexible and wearable electronic devices.

  13. Fabrication and Application of High Quality Diamond-coated Tools

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Diamond-coated tools were fabricated using Co-cemented carbide inserts as substrates by the electronically aided hot filament chemical vapor deposition (EACVD). An amount of additive in an acid solution was used to promote the Co etching of the substrate surface. The surface of the WC-Co substrate was decarburized by microwave plasma with Ar-H 2 gas. Effect of the new substrate pretreatment on the adhesion of diamond films was investigated. A boron-doped solution was brushed on the tool surface to diffuse ...

  14. Mendelian Disorders of High-Density Lipoprotein Metabolism

    NARCIS (Netherlands)

    Oldoni, Federico; Sinke, Richard J.; Kuivenhoven, Jan Albert

    2014-01-01

    High-density lipoproteins (HDLs) are a highly heterogeneous and dynamic group of the smallest and densest lipoproteins present in the circulation. This review provides the current molecular insight into HDL metabolism led by articles describing mutations in genes that have a large affect on HDL chol

  15. Fabrication of hemispherical nano structure on a curved Al surface using low-temperature and high-voltage anodizing method.

    Science.gov (United States)

    Shin, H G; Park, Y M; Kim, B H; Seo, Y H

    2011-01-01

    A simple method of fabricating hemispherical nanostructures on a curved aluminum rod surface was presented. In conventional methods of fabricating nanopatterns on a curved aluminum surface, mechanical or chemical processes have been widely used for the lens technologies. Such processes are not only expensive with long processing times, however, but they also involve local fabrication and are limited in the dimension size. In this paper, a method of fabricating hemispherical nanostructures on a curved aluminum surface is suggested for a functional three-dimensional (3D) master using a low-temperature and high-voltage (LTHV) anodizing method. By reducing the aluminum reaction rate under a low-temperature environment, the reaction current density can be remarkably reduced even though a high voltage was induced. Using the LTHV anodizing method, the hemispherical pattern size can be easily controlled with respect to voltage variations. The sizes of the hemispherical nanopatterns were about 150-300 nm. Using the LTHV anodizing process, hemispherical nanostructures can be obtained on a curved aluminum surface with controllable pattern sizes of 150-300 nm without defects such as burring from Joule's heat, micro-scratches, and cracks. A curved 3D hemispherical nanostructure may be used as a master in the roll-to-roll process.

  16. Cellulose/inorganic-composite fibers for producing textile fabrics of high X-ray absorption properties

    Energy Technology Data Exchange (ETDEWEB)

    Günther, Karoline; Giebing, Christina; Askani, Antonia [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany); Leisegang, Tilmann [Saxray GmbH, Maria-Reiche-Str. 1, 01109 Dresden (Germany); Krieg, Marcus [TITK, Thüringisches Institut für Textil- und Kunststoff-Forschung e.V., Breitscheidstraße 97, 07407 Rudolstadt (Germany); Kyosev, Yordan; Weide, Thomas [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany); Mahltig, Boris, E-mail: Boris.Mahltig@hs-niederrhein.de [FTB, Hochschule Niederrhein – University of Applied Science, Faculty of Textile and Clothing Technology, Webschulstr. 31, 41065 Mönchengladbach (Germany)

    2015-11-01

    Common textile materials as cotton or polyester do not possess reliable X-ray absorption properties. This is due to their morphology and chemical composition in particular. Common fibers are built up from organic polymers containing mainly the elements carbon, hydrogen, oxygen and nitrogen. These “light” elements only have low X-ray absorption coefficients. In contrast, inorganic materials composed of “heavy” elements with high atomic numbers, e.g. barium or bismuth, exhibit X-ray absorption coefficients higher by up to two orders of magnitude. To obtain a flexible yarn with high X-ray absorption properties both these materials, the organic polymer and the inorganic X-ray absorber, are combined to an inorganic/organic composite fiber material. Hence, as the organic component cellulose from modified Lyocell-process is used as carrier fiber and blended with inorganic absorber particles of low toxicity and high absorption coefficients, as bariumsulphate, bariumtitanate or bismuthoxide. A content of inorganic absorber particles equally distributed in the whole fiber of up to 20% is achieved. The composite fibers are produced as staple or filament fibers and processed to multifilament or staple fiber yarns. The staple fiber yarns are rotor-spinned to increase the comfort of the subsequent textile material. Several woven fabrics, considering multilayer structure and different warp/weft density, are developed. The energy dependent X-ray shielding properties are determined in dependence on the different yarn compositions, yarn types and structural parameters of the woven fabrics. As a result, a production process of textile materials with comfortable and dedicated X-ray absorption properties is established. It offers a promising opportunity for manufacturing of specialized textiles, working clothes or uniforms applicable for medicine, air craft and security personal, mining as well as for innovative composite materials. - Highlights: • Preparation of cellulosic

  17. Quark matter at high density based on an extended confined isospin-density-dependent mass model

    Science.gov (United States)

    Qauli, A. I.; Sulaksono, A.

    2016-01-01

    We investigate the effect of the inclusion of relativistic Coulomb terms in a confined-isospin-density-dependent-mass (CIDDM) model of strange quark matter (SQM). We found that if we include the Coulomb term in scalar density form, the SQM equation of state (EOS) at high densities is stiffer but if we include the Coulomb term in vector density form it is softer than that of the standard CIDDM model. We also investigate systematically the role of each term of the extended CIDDM model. Compared with what was reported by Chu and Chen [Astrophys. J. 780, 135 (2014)], we found the stiffness of SQM EOS is controlled by the interplay among the oscillator harmonic, isospin asymmetry and Coulomb contributions depending on the parameter's range of these terms. We have found that the absolute stable condition of SQM and the mass of 2 M⊙ pulsars can constrain the parameter of oscillator harmonic κ1≈0.53 in the case the Coulomb term is excluded. If the Coulomb term is included, for the models with their parameters are consistent with SQM absolute stability condition, the 2.0 M⊙ constraint more prefers the maximum mass prediction of the model with the scalar Coulomb term than that of the model with the vector Coulomb term. On the contrary, the high densities EOS predicted by the model with the vector Coulomb is more compatible with the recent perturbative quantum chromodynamics result [1] than that predicted by the model with the scalar Coulomb. Furthermore, we also observed the quark composition in a very high density region depends quite sensitively on the kind of Coulomb term used.

  18. High-density turbidity currents: Are they sandy debris flows?

    Energy Technology Data Exchange (ETDEWEB)

    Shanmugam, G. [Mobil Exploration and Producing Technical Center, Dallas, TX (United States)

    1996-01-01

    Conventionally, turbidity currents are considered as fluidal flows in which sediment is supported by fluid turbulence, whereas debris flows are plastic flows in which sediment is supported by matrix strength, dispersive pressure, and buoyant lift. The concept of high-density turbidity current refers to high-concentration, commonly non-turbulent, flows of fluids in which sediment is supported mainly by matrix strength, dispersive pressure, and buoyant lift. The conventional wisdom that traction carpets with entrained turbulent clouds on top represent high-density turbidity currents is a misnomer because traction carpets are neither fluidal nor turbulent. Debris flows may also have entrained turbulent clouds on top. The traction carpet/debris flow and the overriding turbulent clouds are two separate entities in terms of flow rheology and sediment-support mechanism. In experimental and theoretical studies, which has linked massive sands and floating clasts to high-density turbidity currents, the term high-density turbidity current has actually been used for laminar flows. In alleviating this conceptual problem, sandy debris flow is suggested as a substitute for high-density turbidity current. Sandy debris flows represent a continuous spectrum of processes between cohesive and cohesionless debris flows. Commonly they are rheologically plastic. They may occur with or without entrained turbulent clouds on top. Their sediment-support mechanisms include matrix strength, dispersive pressure, and buoyant lift. They are characterized by laminar flow conditions, a moderate to high grain concentration, and a low to moderate mud content. Although flows evolve and transform during the course of transport in density-stratified flows, the preserved features in a deposit are useful to decipher only the final stages of deposition. At present, there are no established criteria to decipher transport mechanism from the depositional record.

  19. Combined AFM nano-machining and reactive ion etching to fabricate high aspect ratio structures.

    Science.gov (United States)

    Peng, Ping; Shi, Tielin; Liao, Guanglan; Tang, Zirong

    2010-11-01

    In this paper, a new combined method of sub-micron high aspect ratio structure fabrication is developed which can be used for production of nano imprint template. The process includes atomic force microscope (AFM) scratch nano-machining and reactive ion etching (RIE) fabrication. First, 40 nm aluminum film was deposited on the silicon substrate by magnetron sputtering, and then sub-micron grooves were fabricated on the aluminum film by nano scratch using AFM diamond tip. As aluminum film is a good mask for etching silicon, high aspect ratio structures were finally fabricated by RIE process. The fabricated structures were studied by SEM, which shows that the grooves are about 400 nm in width and 5 microm in depth. To obtain sub-micron scale groove structures on the aluminum film, experiments of nanomachining on aluminum films under various machining conditions were conducted. The depths of the grooves fabricated using different scratch loads were also studied by the AFM. The result shows that the material properties of the film/substrate are elastic-plastic following nearly a bilinear law with isotropic strain hardening. Combined AFM nanomachining and RIE process provides a relative lower cost nano fabrication technique than traditional e-beam lithography, and it has a good prospect in nano imprint template fabrication.

  20. Design of robust hollow fiber membranes with high power density for osmotic energy production

    KAUST Repository

    Zhang, Sui

    2014-04-01

    This study highlights the design strategy of highly asymmetric hollow fiber membranes that possess both characteristics of high flux and high mechanical strength to effectively reap the osmotic energy from seawater brine with an ultrahigh power density. An advanced co-extrusion technology was employed to fabricate the polyethersulfone (PES) hollow fiber supports with diversified structures from macrovoid to sponge-like. The microstructure of the supports is found critical for the stability and water permeability of the thin film composite (TFC) membranes. A high porosity in the porous layer is needed to reduce internal concentration polarization, while a thick and relatively dense skin layer underneath the TFC layer is required to maintain good mechanical stability and stress dissipation. The pore size of the supporting layer underneath the TFC layer must be small with a narrow pore size distribution to ensure the formation of a less-defective, highly permeable and mechanically stable TFC layer. The newly developed hollow fiber comprising high asymmetry, high porosity, and a thick skin layer with a small and narrow pore size distribution underneath the TFC layer produces a maximum power density of 24.3W/m2 at 20.0bar by using 1M NaCl as the concentrated brine and deionized (DI) water as the feed. The proposed design strategy for ultrahigh power density membranes clearly advances the osmotic energy production close to commercialization with a quite cost-effective and practicable approach. © 2013 Elsevier B.V.

  1. High energy density supercapacitors using macroporous kitchen sponges

    KAUST Repository

    Chen, Wei

    2012-01-01

    Macroporous, low-cost and recyclable kitchen sponges are explored as effective electrode platforms for supercapacitor devices. A simple and scalable process has been developed to fabricate MnO 2-carbon nanotube (CNT)-sponge supercapacitor electrodes using ordinary kitchen sponges. Two organic electrolytes (1 M of tetraethylammonium tetrafluoroborate (Et 4NBF 4) in propylene carbonate (PC), 1 M of LiClO 4 in PC) are utilized with the sponge-based electrodes to improve the energy density of the symmetrical supercapacitors. Compared to aqueous electrolyte (1 M of Na 2SO 4 in H 2O), the energy density of supercapacitors tripled in Et 4NBF 4 electrolyte, and further increased by six times in LiClO 4 electrolyte. The long-term cycling performance in different electrolytes was examined and the morphology changes of the electrode materials were also studied. The good electrochemical performance in both aqueous and organic electrolytes indicates that the MnO 2-CNT-sponge is a promising low-cost electrode for energy storage systems. © 2012 The Royal Society of Chemistry.

  2. High performance mask fabrication process for the next-generation mask production

    Science.gov (United States)

    Yagawa, Keisuke; Ugajin, Kunihiro; Suenaga, Machiko; Kobayashi, Yoshihito; Motokawa, Takeharu; Hagihara, Kazuki; Saito, Masato; Itoh, Masamitsu

    2014-07-01

    ArF immersion lithography combined with double patterning has been used for fabricating below half pitch 40nm devices. However, when pattern size shrinks below 20nm, we must use new technology like quadruple patterning process or next generation lithography (NGL) solutions. Moreover, with change in lithography tool, next generation mask production will be needed. According to ITRS 2013, fabrication of finer patterns less than 15nm will be required on mask plate in NGL mask production 5 years later [1]. In order to fabricate finer patterns on mask, higher resolution EB mask writer and high performance fabrication process will be required. In a previous study, we investigated a potential of mask fabrication process for finer patterning and achieved 17nm dense line pattern on mask plate by using VSB (Variable Shaped Beam) type EB mask writer and chemically amplified resist [2][3]. After a further investigation, we constructed higher performance mask process by using new EB mask writer EBM9000. EBM9000 is the equipment supporting hp16nm generation's photomask production and has high accuracy and high throughput. As a result, we achieved 15.5nm pattern on mask with high productivity. Moreover, from evaluation of isolated pattern, we proved that current mask process has the capability for sub-10nm pattern. These results show that the performance of current mask fabrication process have the potential to fabricate the next-generation mask.

  3. High density near amorphous InSb nanowire arrays and its photo-electric performance

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Ming, E-mail: mfang@issp.ac.cn [Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Tan, Xiaoli [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Liu, Mao, E-mail: mliu@issp.ac.cn [Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Gong, Xinxin; Zhang, Lide; Fei, Guangtao [Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanostructure, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China)

    2015-03-25

    Highlights: • InSb near amorphous nanowire arrays are successfully fabricated. • The 30 nm diameter nanowire array shows a well infrared photo-electric response, and the reasons are discussed. • The reason for the black color of the InSb semiconductor is discussed. - Abstract: In this paper, we report the fabrication of high density near amorphous InSb nanowire arrays with using 30, 55 and 70 nm diameter anodic alumina oxide (AAO) template by electrodeposition method. The near amorphous structure was proved by combining the results of X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM). Different from the bulk material, these nanowires are black and could not be analyzed by the traditional method, and the reason was discussed. By testing of the photo-electric performance, the 30 nm diameter InSb nanowire showed the best performance, which could be used at about 260 K. The formation of the near amorphous structure was also discussed. Such high density nanoarrays may found potential application in the infrared detection field.

  4. Frontiers for Discovery in High Energy Density Physics

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, R. C.; Katsouleas, T.; Arons, J.; Baring, M.; Deeney, C.; Di Mauro, L.; Ditmire, T.; Falcone, R.; Hammer, D.; Hill, W.; Jacak, B.; Joshi, C.; Lamb, F.; Lee, R.; Logan, B. G.; Melissinos, A.; Meyerhofer, D.; Mori, W.; Murnane, M.; Remington, B.; Rosner, R.; Schneider, D.; Silvera, I.; Stone, J.; Wilde, B.; Zajc. W.

    2004-07-20

    The report is intended to identify the compelling research opportunities of high intellectual value in high energy density physics. The opportunities for discovery include the broad scope of this highly interdisciplinary field that spans a wide range of physics areas including plasma physics, laser and particle beam physics, nuclear physics, astrophysics, atomic and molecular physics, materials science and condensed matter physics, intense radiation-matter interaction physics, fluid dynamics, and magnetohydrodynamics

  5. Surface nanoscale axial photonics: Robust fabrication of high quality factor microresonators

    CERN Document Server

    Sumetsky, M; Dulashko, Y; Fini, J M; Liu, X; Monberg, E M; Taunay, T F

    2011-01-01

    Recently introduced Surface Nanoscale Axial Photonics (SNAP) makes it possible to fabricate high Q-factor microresonators and other photonic microdevices by dramatically small deformation of the optical fiber surface. To become a practical and robust technology, the SNAP platform requires methods enabling reproducible modification of the optical fiber radius at nanoscale. In this Letter, we demonstrate super-accurate fabrication of high Q-factor microresonators by nanoscale modification of the optical fiber radius and refractive index using the CO2 laser and the UV excimer laser beam exposures. The achieved fabrication accuracy is better than 2 angstroms in variation of the effective fiber radius.

  6. Fabrication of High Aspect Ratio SU-8 Structures for Integrated Spectrometers

    DEFF Research Database (Denmark)

    Anhøj, Thomas Aarøe

    2007-01-01

    of photolithography. Successful fabrication of re ection gratings requires a high degree of precision in the photolithographic process. The fabrication process has thus been optimized by optimizing the photolithographic process for fabrication of high aspect ratio structures, i.e. structures with details...... that are small compared to the height of the structure. A decisive factor is the ability of the process to separate closely- spaced structures. The primary measure of quality is thus the aspect ratio of the narrowest trench which it is possible to resolve in the lithographic process. The optimization...

  7. High numerical aperture imaging by using multimode fibers with micro-fabricated optics

    KAUST Repository

    Bianchi, Silvio

    2014-01-01

    Controlling light propagation into multimode optical fibers through spatial light modulators provides highly miniaturized endoscopes and optical micromanipulation probes. We increase the numerical aperture up to nearly 1 by micro-optics fabricated on the fiber-end.

  8. TRUSSELATOR - On-Orbit Fabrication of High Performance Support Structures for Solar Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Trusselator technology will enable on-orbit fabrication of support structures for high-power solar arrays and large antennas, achieving order-of-magnitude...

  9. TRUSSELATOR - On-Orbit Fabrication of High Performance Support Structures for Solar Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — TUI proposes to develop and demonstrate a process for fabricating high-performance composite truss structures on-orbit and integrating them with thin film solar cell...

  10. Ultrathin, Lightweight, and Wearable Li-O2 Battery with High Robustness and Gravimetric/Volumetric Energy Density.

    Science.gov (United States)

    Liu, Tong; Xu, Ji-Jing; Liu, Qing-Chao; Chang, Zhi-Wen; Yin, Yan-Bin; Yang, Xiao-Yang; Zhang, Xin-Bo

    2017-02-01

    An ultrathin, lightweight, and wearable Li-O2 battery with a novel segmented structure is first fabricated by employing a "break up the whole into parts" strategy. Superior battery performance including low overpotential, high specific capacity, good rate capability, excellent cycle stability, and high gravimetric/volumetric energy density (294.68 Wh kg(-1) /274.06 Wh L(-1) ) is successfully achieved even under repeatedly various deformation.

  11. High-resolution and high-conductive electrode fabrication on a low thermal resistance flexible substrate

    Science.gov (United States)

    Kang, Bongchul; Kno, Jinsung; Yang, Minyang

    2011-07-01

    Processes based on the liquid-state pattern transfer, like inkjet printing, have critical limitations including low resolution and low electrical conductivity when fabricating electrodes on low thermal resistance flexible substrates such as polyethylene terephthalate (PET). Those are due to the nonlinear transfer mechanism and the limit of the sintering temperature. Although the laser direct curing (LDC) of metallic inks is an alternative process to improve the resolution, it is also associated with the disadvantages of causing thermal damage to the polymer substrate. This paper suggests the laser induced pattern adhesion transfer method to fabricate electrodes of both high electrical conductivity and high resolution on a PET substrate. First, solid patterns are cost-effectively created by the LDC of the organometallic silver ink on a glass that is optically and thermally stable. The solid patterns sintered on the glass are transferred to the PET substrate by the photo-thermally generated adhesion force of the substrate. Therefore, we achieved electrodes with a minimum line width of 10 µm and a specific resistance of 3.6 μΩcm on the PET substrate. The patterns also showed high mechanical reliability.

  12. Study of Volumetrically Heated Ultra-High Energy Density Plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Rocca, Jorge J. [Colorado State Univ., Fort Collins, CO (United States)

    2016-10-27

    Heating dense matter to millions of degrees is important for applications, but requires complex and expensive methods. The major goal of the project was to demonstrate using a compact laser the creation of a new ultra-high energy density plasma regime characterized by simultaneous extremely high temperature and high density, and to study it combining experimental measurements and advanced simulations. We have demonstrated that trapping of intense femtosecond laser pulses deep within ordered nanowire arrays can heat near solid density matter into a new ultra hot plasma regime. Extreme electron densities, and temperatures of several tens of million degrees were achieved using laser pulses of only 0.5 J energy from a compact laser. Our x-ray spectra and simulations showed that extremely highly ionized plasma volumes several micrometers in depth are generated by irradiation of gold and Nickel nanowire arrays with femtosecond laser pulses of relativistic intensities. We obtained extraordinarily high degrees of ionization (e.g. we peeled 52 electrons from gold atoms, and up to 26 electrons from nickel atoms). In the process we generated Gigabar pressures only exceeded in the central hot spot of highly compressed thermonuclear fusion plasmas.. The plasma created after the dissolved wires expand, collide, and thermalize, is computed to have a thermal energy density of 0.3 GJ cm-3 and a pressure of 1-2 Gigabar. These are pressures only exceeded in highly compressed thermonuclear fusion plasmas. Scaling these results to higher laser intensities promises to create plasmas with temperatures and pressures exceeding those in the center of the sun.

  13. Achieving high performance polymer optoelectronic devices for high efficiency, long lifetime and low fabrication cost

    Science.gov (United States)

    Huang, Jinsong

    This thesis described three types of organic optoelectronic devices: polymer light emitting diodes (PLED), polymer photovoltaic solar cell, and organic photo detector. The research in this work focuses improving their performance including device efficiency, operation lifetime simplifying fabrication process. With further understanding in PLED device physics, we come up new device operation model and improved device architecture design. This new method is closely related to understanding of the science and physics at organic/metal oxide and metal oxide/metal interface. In our new device design, both material and interface are considered in order to confine and balance all injected carriers, which has been demonstrated very be successful in increasing device efficiency. We created two world records in device efficiency: 18 lm/W for white emission fluorescence PLED, 22 lm/W for red emission phosphorescence PLED. Slow solvent drying process has been demonstrated to significantly increase device efficiency in poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl C 61-butyric acid methyl ester (PCBM) mixture polymer solar cell. From the mobility study by time of flight, the increase of efficiency can be well correlated to the improved carrier transport property due to P3HT crystallization during slow solvent drying. And it is found that, similar to PLED, balanced carrier mobility is essential in high efficient polymer solar cell. There is also a revolution in our device fabrication method. A unique device fabrication method is presented by an electronic glue based lamination process combined with interface modification as a one-step polymer solar cell fabrication process. It can completely skip the thermal evaporation process, and benefit device lifetime by several merits: no air reactive. The device obtained is metal free, semi-transparent, flexible, self-encapsulated, and comparable efficiency with that by regular method. We found the photomultiplication (PM) phenomenon in C

  14. High density operation for reactor-relevant power exhaust

    Science.gov (United States)

    Wischmeier, M.

    2015-08-01

    With increasing size of a tokamak device and associated fusion power gain an increasing power flux density towards the divertor needs to be handled. A solution for handling this power flux is crucial for a safe and economic operation. Using purely geometric arguments in an ITER-like divertor this power flux can be reduced by approximately a factor 100. Based on a conservative extrapolation of current technology for an integrated engineering approach to remove power deposited on plasma facing components a further reduction of the power flux density via volumetric processes in the plasma by up to a factor of 50 is required. Our current ability to interpret existing power exhaust scenarios using numerical transport codes is analyzed and an operational scenario as a potential solution for ITER like divertors under high density and highly radiating reactor-relevant conditions is presented. Alternative concepts for risk mitigation as well as strategies for moving forward are outlined.

  15. Origins and Impacts of High-Density Symmetry Energy

    CERN Document Server

    Li, Bao-An

    2016-01-01

    What is nuclear symmetry energy? Why is it important? What do we know about it? Why is it so uncertain especially at high densities? Can the total symmetry energy or its kinetic part be negative? What are the effects of three-body and/or tensor force on symmetry energy? How can we probe the density dependence of nuclear symmetry energy with terrestrial nuclear experiments? What observables of heavy-ion reactions are sensitive to the high-density behavior of nuclear symmetry energy? How does the symmetry energy affect properties of neutron stars, gravitational waves and our understanding about the nature of strong-field gravity? In this lecture, we try to answer these questions as best as we can based on some of our recent work and/or understanding of research done by others. This note summarizes the main points of the lecture.

  16. Preparation of spherical cobalt carbonate powder with high tap density

    Institute of Scientific and Technical Information of China (English)

    XIAO Jin; WANG Jian-feng; LIU Yong-dong; LI Jie; LIU Ye-xiang

    2006-01-01

    Spherical cobalt carbonate with high tap density, good crystallization and uniform particle size was prepared by controlled chemical crystal method using cobalt chloride and ammonium bicarbonate as cobalt source and precipitator. The effects of pH value and reaction time on crystallization and physical properties of cobalt carbonate were studied. The results show that the key factors influencing the preparation process of spherical cobalt carbonate with high tap density and good crystallization are how to control pH value (7.25 ± 0.05) and keep some reaction time (about 10 h). Co4O3 was prepared by sintering spherical morphology CoCO3 samples at varied temperatures. The results show that as the decomposition temperature increases, the as-obtained Co4O3 products with porous structure transform into polyhedral structure with glazed surface, and simultaneously the cobalt content and tap density increase. However, the specific surface area shows a trend of decrease.

  17. Development of high-density single-mode polymer waveguides with low crosstalk for chip-to-chip optical interconnection.

    Science.gov (United States)

    Sugama, Akio; Kawaguchi, Kenichi; Nishizawa, Motoyuki; Muranaka, Hidenobu; Arakawa, Yasuhiko

    2013-10-01

    High-density single-mode polymer waveguides were fabricated for chip-to-chip optical interconnection. The waveguides were designed as minimized mode field diameters for the lowest inter-channel crosstalk caused by mode coupling. The optimum relative index difference chosen was 1.2% to ensure compatibility with low crosstalk and wide fabrication tolerances. The 60-mm-length linear waveguides demonstrated a low propagation loss of 0.6 dB/cm and -45 dB crosstalk at 1310 nm. Also, a new crosstalk mechanism for a curved waveguide was revealed.

  18. Facile fabrication of ultrathin hybrid membrane for highly flexible supercapacitors via in-situ phase separation of polyethersulfone

    Science.gov (United States)

    Zhao, Xiaoning; Ran, Fen; Shen, Kuiwen; Yang, Yunlong; Wu, Jiayu; Niu, Xiaoqin; Kong, Lingbin; Kang, Long; Chen, Shaowei

    2016-10-01

    In this article, a facile method based on in-situ phase-separation was developed for the fabrication of ultrathin hybrid membranes for highly flexible supercapacitors. The structures and morphologies of the prepared electrodes were characterized by scanning electron microscopy (SEM), Fourier-transformed infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA) measurements; and the electrochemical behaviors were examined in 2 M KOH solution. SEM and FTIR characterizations reveal that activated carbon was imbedded into the polymer membrane of polyethersulfone to form a uniform and flexible hybrid membrane. When the thin polymer-carbon membrane (PCM) was used as an electrode material for supercapacitor, a high specific capacitance of 169.4 Fg-1 was obtained at a current density of 0.5 Ag-1 along with good long-term cycle life of 94.6% capacity retention after 2000 charging-discharging cycles. Benefiting from these merits, the as-fabricated PCM//PCM cell shows an excellent electrochemical property. These results suggest a promising route towards the fabrication of highly flexible electrodes for high-performance supercapacitors.

  19. Preparation of ceria with large particle size and high appearance density

    Institute of Scientific and Technical Information of China (English)

    WANG Songling; LIU Junyun; JIA Jiangtao; LIAO Chunsheng; YAN Chunhua

    2008-01-01

    Cerium is one of the most abundant rare earth dements in both bastnasite and monazite. Ceria has been widely used in optical catalytic, electrolyte, and sensor materials, with unique performances. With the development of functional materials, great interest has been focused on the synthesis and characterization of specific fine/mesoporous ceria powder. In this study, the modified precipitation and recrystallization processes combined with a controlled calcination process for fabricating the ceria with large particle size and high appearance density was reported. During precipitation, a certain amount of mineral acid such as nitric acid served as an additive, to adjust the precipitation and crystallization processes of cerium oxalates. An appropriate acidic condition could lead the process into the Oswald ripening stage and made the particles become bigger. Thus, the appearance density of powder was increased. The optimized conditions, such as the temperature, feeding speed, type and concentration of mineral acids, and the concentration of cerium-contained stock solution, were investigated and evaluated.

  20. Liquid-crystalline polymer holograms for high-density optical storage and photomechanical analysis

    Science.gov (United States)

    Shishido, A.; Akamatsu, N.

    2012-10-01

    We report linear and crosslinked azobenzene containing liquid-crystalline polymers which can be applied to high-density optical storage and photomechanical analysis. We introduced a molecular design concept of multicomponent systems composed of photoresponse, refactive-index change amplification, and transparency units. Taking advantage of characteristics of liquid crystals (optical anisotropy and cooperative motion), polarization holograms were recorded, which enabled us higher-density holographic storage. On the other hand, crosslinked liquid-crystalline azobenzene polymer films were fabricated to investigate the photomechanical behavior. We have found that a large change in Young's modulus is induced by several mol%-cis form production. Furthermore, a unique bending behavior, which cannot be explained by the conventional bending mechanism, was observed in the crosslinked liquid-crystalline polymer films with azobenzene in the side chain.

  1. A High Power-Density Mediator-Free Microfluidic Biophotovoltaic Device for Cyanobacterial Cells

    CERN Document Server

    Bombelli, Paolo; Herling, Therese W; Howe, Christopher J; Knowles, Tuomas P J

    2014-01-01

    Biophotovoltaics has emerged as a promising technology for generating renewable energy since it relies on living organisms as inexpensive, self-repairing and readily available catalysts to produce electricity from an abundant resource - sunlight. The efficiency of biophotovoltaic cells, however, has remained significantly lower than that achievable through synthetic materials. Here, we devise a platform to harness the large power densities afforded by miniaturised geometries. To this effect, we have developed a soft-lithography approach for the fabrication of microfluidic biophotovoltaic devices that do not require membranes or mediators. Synechocystis sp. PCC 6803 cells were injected and allowed to settle on the anode, permitting the physical proximity between cells and electrode required for mediator-free operation. We demonstrate power densities of above 100 mW/m2 for a chlorophyll concentration of 100 {\\mu}M under white light, a high value for biophotovoltaic devices without extrinsic supply of additional...

  2. High energy density capacitor using coal tar pitch derived nanoporous carbon/MnO{sub 2} electrodes in aqueous electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Tomko, Timothy [Energy and Mineral Engineering, University Park, PA 16802 (United States); Rajagopalan, Ramakrishnan; Lanagan, Michael [Materials Research Institute, University Park, PA 16802 (United States); Foley, Henry C. [Department of Chemical Engineering, University Park, PA 16802 (United States)

    2011-02-15

    Asymmetric aqueous electrochemical capacitors with energy densities as high as 22 Wh kg{sup -1}, power densities of 11 kW kg{sup -1} and a cell voltage of 2 V were fabricated using cost effective, high surface carbon derived from coal tar pitch and manganese dioxide. The narrow pore size distribution of the activated carbon (mean pore size {proportional_to}0.8 nm) resulted in strong electroadsorption of protons making them suitable for use as negative electrodes. Amorphous manganese dioxide anodes were synthesized by chemical precipitation method with high specific capacitance (300 F g{sup -1}) in aqueous electrolytes containing bivalent cations. The fabricated capacitors demonstrated excellent cyclability with no signs of capacitance fading even after 1000 cycles. (author)

  3. Theoretical Study on the High Energy Density Compound Hexanitrohexaazatricyclotetradecanedifuroxan

    Institute of Scientific and Technical Information of China (English)

    QIU Ling; XIAO He-Ming; ZHU Wei-Hua; JU Xue-Hai; GONG Xue-Dong

    2006-01-01

    Density functional theory (DFT) has been employed to study the molecular geometries, electronic structures,infrared (IR) spectra, and thermodynamic properties of the high energy density compound hexanitrohexaazatricyclotetradecanedifuroxan (HHTTD) at the B3LYP/6-31G** level of theory. The calculated results showthattherearefourconformationalisomers (a, β, γ and δ) for HHTTD, and the relative stabilities of four conformers were assessed based on the calculated total energies and the energy-gaps between the frontier molecular orbitals. The computed harmonic vibrational frequencies are in reasonable agreement with the available experimental data. Thermodynamic properties derived from the IR spectra on the basis of statistical thermodynamic principles are linearly correlated with the temperature. Detonation performances were evaluated by using the Kamlet-Jacobsequationsbasedonthecalculated densities and heats of formation. It was found that four HHTTD isomers with the predicted densities of ca. 2 g·cm-3, detonation velocities near 10 km·s-1, and detonation pressures over 45 Gpa, may be novel potential candidates of high energy density materials (HEDM). These results may provide basic information for the molecular designof HEDM.

  4. A high energy density relaxor antiferroelectric pulsed capacitor dielectric

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Hwan Ryul; Lynch, Christopher S. [Department of Mechanical and Aerospace Engineering, University of California, Los Angeles (UCLA), Los Angeles, California 90095 (United States)

    2016-01-14

    Pulsed capacitors require high energy density and low loss, properties that can be realized through selection of composition. Ceramic (Pb{sub 0.88}La{sub 0.08})(Zr{sub 0.91}Ti{sub 0.09})O{sub 3} was found to be an ideal candidate. La{sup 3+} doping and excess PbO were used to produce relaxor antiferroelectric behavior with slim and slanted hysteresis loops to reduce the dielectric hysteresis loss, to increase the dielectric strength, and to increase the discharge energy density. The discharge energy density of this composition was found to be 3.04 J/cm{sup 3} with applied electric field of 170 kV/cm, and the energy efficiency, defined as the ratio of the discharge energy density to the charging energy density, was 0.920. This high efficiency reduces the heat generated under cyclic loading and improves the reliability. The properties were observed to degrade some with temperature increase above 80 °C. Repeated electric field cycles up to 10 000 cycles were applied to the specimen with no observed performance degradation.

  5. A high current density DC magnetohydrodynamic (MHD) micropump

    NARCIS (Netherlands)

    Homsy, Alexandra; Koster, Sander; Eijkel, Jan C.T.; Berg, van den Albert; Lucklum, F.; Verpoorte, E.; Rooij, de Nico F.

    2005-01-01

    This paper describes the working principle of a DC magnetohydrodynamic (MHD) micropump that can be operated at high DC current densities (J) in 75-µm-deep microfluidic channels without introducing gas bubbles into the pumping channel. The main design feature for current generation is a micromachined

  6. A high current density DC magnetohydrodynamic (MHD) micropump

    NARCIS (Netherlands)

    Homsy, A; Koster, Sander; Eijkel, JCT; van den Berg, A; Lucklum, F; Verpoorte, E; de Rooij, NF

    2005-01-01

    This paper describes the working principle of a DC magnetohydrodynamic (MHD) micropump that can be operated at high DC current densities (J) in 75-mu m-deep microfluidic channels without introducing gas bubbles into the pumping channel. The main design feature for current generation is a micromachin

  7. Intraocular inflammation following endotamponade with high-density silicone oil.

    NARCIS (Netherlands)

    Theelen, T.; Tilanus, M.A.D.; Klevering, B.J.

    2004-01-01

    BACKGROUND: The use of a mixture of silicone oil and partially fluorinated alkanes (high-density silicone oil) has recently been suggested as intraocular tamponade in complicated retinal detachment of the inferior quadrants. We describe a series of patients who developed a clinical picture resemblin

  8. Two-Dimensional Super High Density Multi-Fiber Connector

    Institute of Scientific and Technical Information of China (English)

    Takashi Shigenaga; Katsuki Suematsu; Masao Shinoda; Takayuki Ando

    2003-01-01

    We have developed 32-fiber and 60-fiber super high density multi fiber connector. This 32-fiber connector can be applicable for single-mode fiber and 60-fiber connector for multi-mode fiber. We have also established PC (physical contact) connection technology by optimizing polishing condition and clamping force.

  9. Interaction effects in high density magnetic particulate media

    Energy Technology Data Exchange (ETDEWEB)

    Cerchez, Mihai; Stoleriu, Laurentiu; Stancu, Alexandru

    2004-01-01

    The paper presents a micromagnetic study of the particulate high density recording media. The main difference in the behavior of such a system is the appearance of magnetic clusters which lead to a different behavior of the system. New hypotheses for interpreting such systems are presented.

  10. Metabolism of high density lipoproteins in liver cancer

    Institute of Scientific and Technical Information of China (English)

    Jing-Ting Jiang; Ning Xu; Chang-Ping Wu

    2007-01-01

    Liver plays a vital role in the production and catabolism of plasma lipoproteins. It depends on the integrity of cellular function of liver, which ensures homeostasis of lipid and lipoprotein metabolism. When liver cancer occurs these processes are impaired and high-density lipoproteins are changed.

  11. High Energy Density Physics and Exotic Acceleration Schemes

    Science.gov (United States)

    Cowan, Thomas; Colby, Eric

    2002-12-01

    We summarize the reported results and the principal technical discussions that occurred in our Working Group on High Energy Density Physics and Exotic Acceleration Schemes at the 2002 workshop on Advanced Accelerator Concepts at the Mandalay Beach resort, June 22-28, 2002.

  12. Intraocular inflammation following endotamponade with high-density silicone oil.

    NARCIS (Netherlands)

    Theelen, T.; Tilanus, M.A.D.; Klevering, B.J.

    2004-01-01

    BACKGROUND: The use of a mixture of silicone oil and partially fluorinated alkanes (high-density silicone oil) has recently been suggested as intraocular tamponade in complicated retinal detachment of the inferior quadrants. We describe a series of patients who developed a clinical picture

  13. A Novel Anti-Inflammatory Effect for High Density Lipoprotein.

    Directory of Open Access Journals (Sweden)

    Scott J Cameron

    Full Text Available High density lipoprotein has anti-inflammatory effects in addition to mediating reverse cholesterol transport. While many of the chronic anti-inflammatory effects of high density lipoprotein (HDL are attributed to changes in cell adhesion molecules, little is known about acute signal transduction events elicited by HDL in endothelial cells. We now show that high density lipoprotein decreases endothelial cell exocytosis, the first step in leukocyte trafficking. ApoA-I, a major apolipoprotein of HDL, mediates inhibition of endothelial cell exocytosis by interacting with endothelial scavenger receptor-BI which triggers an intracellular protective signaling cascade involving protein kinase C (PKC. Other apolipoproteins within the HDL particle have only modest effects upon endothelial exocytosis. Using a human primary culture of endothelial cells and murine apo-AI knockout mice, we show that apo-AI prevents endothelial cell exocytosis which limits leukocyte recruitment. These data suggest that high density lipoprotein may inhibit diseases associated with vascular inflammation in part by blocking endothelial exocytosis.

  14. High follicle density does not decrease sweat gland density in Huacaya alpacas.

    Science.gov (United States)

    Moore, K E; Maloney, S K; Blache, D

    2015-01-01

    When exposed to high ambient temperatures, mammals lose heat evaporatively by either sweating from glands in the skin or by respiratory panting. Like other camelids, alpacas are thought to evaporate more water by sweating than panting, despite a thick fleece, unlike sheep which mostly pant in response to heat stress. Alpacas were brought to Australia to develop an alternative fibre industry to sheep wool. In Australia, alpacas can be exposed to ambient temperatures higher than in their native South America. As a young industry there is a great deal of variation in the quality and quantity of the fleece produced in the national flock. There is selection pressure towards animals with finer and denser fleeces. Because the fibre from secondary follicles is finer than that from primary follicles, selecting for finer fibres might alter the ratio of primary and secondary follicles. In turn the selection might alter sweat gland density because the sweat glands are associated with the primary follicle. Skin biopsy and fibre samples were obtained from the mid-section of 33 Huacaya alpacas and the skin sections were processed into horizontal sections at the sebaceous gland level. Total, primary, and secondary follicles and the number of sweat gland ducts were quantified. Fibre samples from each alpaca were further analysed for mean fibre diameter. The finer-fibred animals had a higher total follicle density (P<0.001) and more sweat glands (P<0.001) than the thicker-fibred animals. The fibre diameter and total follicle density were negatively correlated (R(2)=0.56, P<0.001). Given that the finer-fibred animals had higher follicle density and more sweat glands than animals with thicker fibres, we conclude that alpacas with high follicle density should not be limited for potential sweating ability. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Interfacial Tension and Surface Pressure of High Density Lipoprotein, Low Density Lipoprotein, and Related Lipid Droplets

    DEFF Research Database (Denmark)

    Ollila, O. H. S.; Lamberg, A.; Lehtivaara, M.

    2012-01-01

    Lipid droplets play a central role in energy storage and metabolism on a cellular scale. Their core is comprised of hydrophobic lipids covered by a surface region consisting of amphiphilic lipids and proteins. For example, high and low density lipoproteins (HDL and LDL, respectively) are essentia...... of interfacial tension becomes significant for particles with a radius of similar to 5 nm, when the area per molecule in the surface region is...

  16. Ag incorporated Mn3O4/AC nanocomposite based supercapacitor devices with high energy density and power density.

    Science.gov (United States)

    Nagamuthu, S; Vijayakumar, S; Muralidharan, G

    2014-12-14

    Silver incorporated Mn3O4/amorphous carbon (AC) nanocomposites are synthesized by a green chemistry method. X-ray diffraction studies revealed the structural changes in Mn3O4/AC nanocomposites attributable to the addition of silver. Cyclic voltammetry, charge-discharge and ac-impedance studies indicated that the Ag-Mn3O4/AC-5 electrode was the most suitable candidate for supercapacitor applications. From the galvanostatic charge-discharge studies, a higher specific capacitance of 981 F g(-1) at a specific current of 1 A g(-1) was obtained. An Ag-Mn3O4/AC-symmetric supercapacitor consisting of an Ag-incorporated Mn3O4/AC composite as an anode as well as a cathode, and an asymmetric supercapacitor consisting of an Ag-incorporated Mn3O4/AC composite as a cathode and an activated carbon as an anode have been fabricated. The symmetric device exhibits a specific cell capacitance of 72 F g(-1) at a specific current of 1 A g(-1) whereas the asymmetric device delivers a specific cell capacitance of 180 F g(-1) at a high current rate of 10 A g(-1). The asymmetric supercapacitor device yields a high energy density of 81 W h kg(-1). This is higher than that of lead acid batteries and comparable with that of nickel hydride batteries.

  17. Extreme states of matter high energy density physics

    CERN Document Server

    Fortov, Vladimir E

    2016-01-01

    With its many beautiful colour pictures, this book gives fascinating insights into the unusual forms and behaviour of matter under extremely high pressures and temperatures. These extreme states are generated, among other things, by strong shock, detonation and electric explosion waves, dense laser beams,electron and ion beams, hypersonic entry of spacecraft into dense atmospheres of planets, and in many other situations characterized by extremely high pressures and temperatures.Written by one of the world's foremost experts on the topic, this book will inform and fascinate all scientists dealing with materials properties and physics, and also serve as an excellent introduction to plasma-, shock-wave and high-energy-density physics for students and newcomers seeking an overview. This second edition is thoroughly revised and expanded, in particular with new material on high energy-density physics, nuclear explosions and other nuclear transformation processes.

  18. Fabrication of high aspect ratio nanocell lattices by ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, Osamu [School of Environmental Science and Technology, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502 (Japan); Nitta, Noriko, E-mail: nitta.noriko@kochi-tech.ac.jp [School of Environmental Science and Technology, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502 (Japan); Center for Nanotechnology, Research Institute, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502 (Japan); Taniwaki, Masafumi [School of Environmental Science and Technology, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502 (Japan)

    2016-11-01

    Highlights: • Nanocell lattice with a high aspect ratio on InSb semiconductor surface was fabricated by ion beam irradiation. • The fabrication technique consisting of top-down and bottom-up processes was performed in FIB. • High aspect ratio of 2 was achieved in nanocell lattice with a 100 nm interval. • The intermediate-flux irradiation is favorable for fabrication of nanocell with a high aspect ratio. - Abstract: A high aspect ratio nanocell lattice was fabricated on the InSb semiconductor surface using the migration of point defects induced by ion beam irradiation. The fabrication technique consisting of the top-down (formation of voids and holes) and bottom-up (growth of voids and holes into nanocells) processes was performed using a focused ion beam (FIB) system. A cell aspect ratio of 2 (cell height/cell diameter) was achieved for the nanocell lattice with a 100 nm dot interval The intermediate-flux ion irradiation during the bottom-up process was found to be optimal for the fabrication of a high aspect ratio nanocell.

  19. Quark Matter at High Density based on Extended Confined-isospin-density-dependent-mass Model

    CERN Document Server

    Qauli, A I

    2016-01-01

    We investigate the effect of the inclusion of relativistic Coulomb terms in a confined-isospin-density-dependent-mass (CIDDM) model of strange quark matter (SQM). We found that if we include Coulomb term in scalar density form, SQM equation of state (EOS) at high densities is stiffer but if we include Coulomb term in vector density form is softer than that of standard CIDDM model. We also investigate systematically the role of each term of the extended CIDDM model. Compared with what was reported in Ref.~\\cite {ref:isospin}, we found the stiffness of SQM EOS is controlled by the interplay among the the oscillator harmonic, isospin asymmetry and Coulomb contributions depending on the parameter's range of these terms. We have found that the absolute stable condition of SQM and the mass of 2 $M_\\odot$ pulsars can constrain the parameter of oscillator harmonic $\\kappa_1$ $\\approx 0.53$ in the case Coulomb term excluded. If the Coulomb term is included, for the models with their parameters are consistent with SQM ...

  20. Fabrication of vertically aligned diamond whiskers from highly boron-doped diamond by oxygen plasma etching.

    Science.gov (United States)

    Terashima, Chiaki; Arihara, Kazuki; Okazaki, Sohei; Shichi, Tetsuya; Tryk, Donald A; Shirafuji, Tatsuru; Saito, Nagahiro; Takai, Osamu; Fujishima, Akira

    2011-02-01

    Conductive diamond whiskers were fabricated by maskless oxygen plasma etching on highly boron-doped diamond substrates. The effects of the etching conditions and the boron concentration in diamond on the whisker morphology and overall substrate coverage were investigated. High boron-doping levels (greater than 8.4 × 10(20) cm(-3)) are crucial for the formation of the nanosized, densely packed whiskers with diameter of ca. 20 nm, length of ca. 200 nm, and density of ca. 3.8 × 10(10) cm(-2) under optimal oxygen plasma etching conditions (10 min at a chamber pressure of 20 Pa). Confocal Raman mapping and scanning electron microscopy illustrate that the boron distribution in the diamond surface region is consistent with the distribution of whisker sites. The boron dopant atoms in the diamond appear to lead to the initial fine column formation. This simple method could provide a facile, cost-effective means for the preparation of conductive nanostructured diamond materials for electrochemical applications as well as electron emission devices.

  1. High-Density Stacked Ru Nanocrystals for Nonvolatile Memory Application

    Institute of Scientific and Technical Information of China (English)

    MAO Ping; ZHANG Zhi-Gang; PAN Li-Yang; XU Jun; CHEN Pei-Yi

    2009-01-01

    @@ Stacked ruthenium (Ru) nanocrystals (NCs) are formed by rapid thermal annealing for the whole gate stacks and embedded in memory structure, which is compatible with conventional CMOS technology. Ru NCs with high density (3×1012 cm-2 ), small size (2-4 nm) and good uniformity both in aerial distribution and morphology are formed. Attributed to the higher surface trap density, a memory window of 5.2 V is obtained with stacked Ru NCs in comparison to that of 3.5 V with single-layer samples. The stacked Ru NCs device also exhibits much better retention performance because of Coulomb blockade and vertical uniformity between stacked Ru NCs.

  2. λ/26 silver nanodots fabricated by direct laser writing through highly sensitive two-photon photoreduction

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Yaoyu; Gu, Min, E-mail: mgu@swin.edu.au [Centre for Micro-Photonics and CUDOS, Faculty of Engineering and Industrial Sciences, Swinburne University of Technology, P.O. Box 218, Hawthorn, Victoria 3122 (Australia)

    2013-11-18

    We demonstrated an approach to break the diffraction limit and realise deep-subwavelength two-photon direct laser writing by employing a highly sensitive photoreduction process. The photoreduction photosensitivity increased by at least 4 times while the wavelength of the fabrication laser beam was tuned from 800 nm to 580 nm. The increase of the photosensitivity resulted in improved resolution for the silver dot fabrication. By developing the photoreduction material with adding electron donors, the photosensitivity further increased and enabled the realisation of a single silver dot at 22 nm which is λ/26 for the wavelength of the fabrication laser beam.

  3. Polarization-independent high-index contrast grating and its fabrication tolerances

    DEFF Research Database (Denmark)

    Ikeda, Kazuhiro; Takeuchi, Kazuma; Takayose, Kentaro

    2013-01-01

    A polarization-independent, high-index contrast grating (HCG) with a single layer of cross stripes allowing simple fabrication is proposed. Since the cross stripes structure can be suspended in air by selectively wet-etching the layer below, all the layers can be grown at once when implemented...... also investigated the fabrication tolerances of the structure and found that, assuming careful optimizations of electron beam lithography for the precise grating width and dry-etching for the vertical sidewall, the suggested polarization-independent HCG can be fabricated using standard technologies....

  4. Wafer-scale fabrication of high-aspect ratio nanochannels based on edge-lithography technique.

    Science.gov (United States)

    Xie, Quan; Zhou, Qing; Xie, Fei; Sang, Jianming; Wang, Wei; Zhang, Haixia Alice; Wu, Wengang; Li, Zhihong

    2012-03-01

    This paper introduced a wafer-scale fabrication approach for the preparation of nanochannels with high-aspect ratio (the ratio of the channel depth to its width). Edge lithography was used to pattern nanogaps in an aluminum film, which was functioned as deep reactive ion etching mask thereafter to form the nanochannel. Nanochannels with aspect ratio up to 172 and width down to 44 nm were successfully fabricated on a 4-inch Si wafer with width nonuniformity less than 13.6%. A microfluidic chip integrated with nanometer-sized filters was successfully fabricated by utilizing the present method for geometric-controllable nanoparticle packing.

  5. Fabrication of Hierarchical Porous Carbon Nanoflakes for High-Performance Supercapacitors.

    Science.gov (United States)

    Yao, Yamin; Zhang, Yunqiang; Li, Li; Wang, Shulan; Dou, Shi Xue; Liu, Xuan

    2017-09-18

    In the current work, the carbon nanoflakes (CNs-Fe/KOH) and porous carbon (PC-Ni/KOH) have been produced by using Fe(NO3)3/KOH and Ni(NO3)2/KOH as the co-graphitization/activation catalysts to treat the natural plane tree fluff, respectively. The as-prepared carbon materials show different morphologies when treated with different metal ions. Compared with PC-Ni/KOH, the CNs-Fe/KOH have both high graphitization degree (IG/ID = 1.53) and large SBET (1416 m2/g). In a three-electrode setup, the CNs-Fe/KOH electrode shows a high specific capacitance of 253 F/g at 10 A/g, with a capacitance retention of 92.64% after 10000 cycles in 2 M H2SO4 aqueous solution, which is far better than the sample without Fe3+ addition. In 1 M LiPF6 in ethylene carbonate/diethyl carbonate organic solution, CNs-Fe/KOH based symmetric supercapacitor also presents an excellent specific capacitance of 32.2 F/g at 1 A/g. In addition, an energy density of 39.98 W h/kg can be achieved at the power density of 1.49 kW/kg. Influence of metal ions on the morphology, structure as well as electrochemical performance of the carbon materials are further analyzed in detail. The current work provides a novel path for design and fabrication of supercapacitor electrode materials with promising electrochemical performances.

  6. Temperature dependence of the optical properties of high-density GaAs quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Ryan P.; Kim, Jongsu [Yeungnam University, Gyeongsan (Korea, Republic of); Lee, Sangjun; Noh, Samkyu [Korea Research Institute of Standards and Science, Daejeon (Korea, Republic of); Kim, Jinsoo [Chonbuk National University, Jeonju (Korea, Republic of); Leem, Jaeyoung [Inje University, Gimhae (Korea, Republic of); Song, Jindong [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

    2012-05-15

    We investigate the effect of the quantum dot (QD) density on the thermal escape and the retrapping processes of carriers for unstrained GaAs/AlGaAs QDs through temperature-dependent photoluminescence measurements. We fabricated high-density GaAs QDs (8.4 x 10{sup 10}/cm{sup 2}, dot-dot distance ∼34 nm) on an Al{sub 0.3}Ga{sub 0.7}As/GaAs (111)A surface by using droplet epitaxy. The average lateral size and height of the GaAs QDs are 24 and 6 nm, respectively. Temperature-dependent photoluminescence (PL) studies show that high-density GaAs QDs undergo a sigmoidal-shape energy shift. The sigmoidal dependence of the PL peak energy can be explained by thermal escaping of carriers followed by re-trapping by QDs. Our analysis indicates that the re-trapping probability of thermally-escaped carriers increases with decreasing dot-to-dot distance (corresponding to an increase in the QD density).

  7. High-Sensitivity Measurement of Density by Magnetic Levitation.

    Science.gov (United States)

    Nemiroski, Alex; Kumar, A A; Soh, Siowling; Harburg, Daniel V; Yu, Hai-Dong; Whitesides, George M

    2016-03-01

    This paper presents methods that use Magnetic Levitation (MagLev) to measure very small differences in density of solid diamagnetic objects suspended in a paramagnetic medium. Previous work in this field has shown that, while it is a convenient method, standard MagLev (i.e., where the direction of magnetization and gravitational force are parallel) cannot resolve differences in density mm) because (i) objects close in density prevent each other from reaching an equilibrium height due to hard contact and excluded volume, and (ii) using weaker magnets or reducing the magnetic susceptibility of the medium destabilizes the magnetic trap. The present work investigates the use of weak magnetic gradients parallel to the faces of the magnets as a means of increasing the sensitivity of MagLev without destabilization. Configuring the MagLev device in a rotated state (i.e., where the direction of magnetization and gravitational force are perpendicular) relative to the standard configuration enables simple measurements along the axes with the highest sensitivity to changes in density. Manipulating the distance of separation between the magnets or the lengths of the magnets (along the axis of measurement) enables the sensitivity to be tuned. These modifications enable an improvement in the resolution up to 100-fold over the standard configuration, and measurements with resolution down to 10(-6) g/cm(3). Three examples of characterizing the small differences in density among samples of materials having ostensibly indistinguishable densities-Nylon spheres, PMMA spheres, and drug spheres-demonstrate the applicability of rotated Maglev to measuring the density of small (0.1-1 mm) objects with high sensitivity. This capability will be useful in materials science, separations, and quality control of manufactured objects.

  8. Rf Gun with High-Current Density Field Emission Cathode

    Energy Technology Data Exchange (ETDEWEB)

    Jay L. Hirshfield

    2005-12-19

    High current-density field emission from an array of carbon nanotubes, with field-emission-transistor control, and with secondary electron channel multiplication in a ceramic facing structure, have been combined in a cold cathode for rf guns and diode guns. Electrodynamic and space-charge flow simulations were conducted to specify the cathode configuration and range of emission current density from the field emission cold cathode. Design of this cathode has been made for installation and testing in an existing S-band 2-1/2 cell rf gun. With emission control and modulation, and with current density in the range of 0.1-1 kA/cm2, this cathode could provide performance and long-life not enjoyed by other currently-available cathodes

  9. Collapsing Bubble in Metal for High Energy Density Physics Study

    Energy Technology Data Exchange (ETDEWEB)

    Ng, S F; Barnard, J J; Leung, P T; Yu, S S

    2011-04-13

    This paper presents a new idea to produce matter in the high energy density physics (HEDP) regime in the laboratory using an intense ion beam. A gas bubble created inside a solid metal may collapse by driving it with an intense ion beam. The melted metal will compress the gas bubble and supply extra energy to it. Simulations show that the spherical implosion ratio can be about 5 and at the stagnation point, the maximum density, temperature and pressure inside the gas bubble can go up to nearly 2 times solid density, 10 eV and a few megabar (Mbar) respectively. The proposed experiment is the first to permit access into the Mbar regime with existing or near-term ion facilities, and opens up possibilities for new physics gained through careful comparisons of simulations with measurements of quantities like stagnation radius, peak temperature and peak pressure at the metal wall.

  10. High resolution nanoimprint templates for dual damascene: fabrication and imprint results

    Science.gov (United States)

    Irmscher, Mathias; Butschke, Joerg; Carpio, Ron; Chao, Brook; Jen, Wei-Lun; Koepernik, Corinna; Nedelmann, Lorenz; Owens, Jordan; Palmieri, Frank; Pritschow, Marcus; Reuter, Christian; Sailer, Holger; Satoodeh, Ken; Wetzel, Jeff; Wilks, Bruce; Willson, Grant

    2008-03-01

    A dual damascene template fabrication process has been developed, which enables the structuring of high-resolution, high-aspect pillars on top of lines. Based on this technology templates with three different designs have been fabricated and characterized. Two templates are dedicated for an assessment of the fabrication process using a regular test design on one hand and an arbitrary CMOS design on the other hand. With the third template via chains shall be later realized as demonstrator for electrical tests. The templates have been imprinted in resist and sacrificial material on an Imprio 55 and an Imprio 100 tool. The usability of each fabricated template could be confirmed for the specific application. For the template manufacturing a Vistec variable shape e-beam (VSB) writer SB352HR and appropriate positive-tone and negative-tone chemically amplified resists (CAR) have been used.

  11. Fabrication and tolerances of optics for high concentration photovoltaics

    OpenAIRE

    Benitez Gimenez, Pablo; Miñano Dominguez, Juan Carlos; Ahmadpanaih, Hamed; Mendes Lopes, Joao; Zamora Herranz, Pablo

    2014-01-01

    High Concentration Photovoltaics (HCPV) require an optical system with high efficiency, low cost and large tolerance. We describe the particularities of the HCPV applications, which constrain the optics design and the manufacturing techonologies.

  12. Fabrication and characterisation of low density polyethylene (LDPE/multi walled carbon nanotubes (MWCNTs nano-composites

    Directory of Open Access Journals (Sweden)

    Meenakshi Goyal

    2016-09-01

    Full Text Available Carbon nanotubes (CNT have shown extraordinary electrical, mechanical properties as well as many other physical properties. The aim of this study is to explore the scope of CNT/LDPE nano-composites for engineering applications. Nano-composites of LDPE and MWCNT are generally prepared by using the melt blending method but in the present investigation these have been prepared by using solvent mixing method. Xylene has been used as a solvent which can dissolve low density polyethylene (LDPE at about 125 °C. The solution of LDPE in xylene has been ultrasonicated with various percentages of MWCNT (0, 1, 2, 5, 10 wt% of MWCNT composite to form thin film after drying. MWCNT used in this study have been synthesised by electric arc discharge method. Characteristics of these composites have been determined by Raman spectroscopy and scanning electron microscopy (SEM. Raman spectroscopy revealed variation in intensity of CNT's peak with variation in concentration of CNT. The results indicated that intensity of CNT's peak was found to increase with the increase in concentration of CNT which indicated the type of interaction between polymer and CNT. SEM analysis reveals CNT-polymer interfacial adhesion and shows agglomeration of CNT's at some locations and presence of individual tubes at other locations. These investigations show that LDPE/MWCNT composites can be fabricated using simple solvent mixing method. Further investigation on the effect of MWCNT on mechanical, electrical and thermal properties of LDPE based composites are in progress.

  13. High energy-density science on the National Ignition Facility

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, E.M.; Cauble, R.; Remington, B.A.

    1997-08-01

    The National Ignition Facility, as well as its French counterpart Le Laser Megajoule, have been designed to confront one of the most difficult and compelling problem in shock physics - the creation of a hot, compassed DT plasma surrounded and confined by cold, nearly degenerate DT fuel. At the same time, these laser facilities will present the shock physics community with unique tools for the study of high energy density matter at states unreachable by any other laboratory technique. Here we describe how these lasers can contribute to investigations of high energy density in the area of material properties and equations of state, extend present laboratory shock techniques such as high-speed jets to new regimes, and allow study of extreme conditions found in astrophysical phenomena.

  14. Rationally designed polyimides for high-energy density capacitor applications.

    Science.gov (United States)

    Ma, Rui; Baldwin, Aaron F; Wang, Chenchen; Offenbach, Ido; Cakmak, Mukerrem; Ramprasad, Rampi; Sotzing, Gregory A

    2014-07-01

    Development of new dielectric materials is of great importance for a wide range of applications for modern electronics and electrical power systems. The state-of-the-art polymer dielectric is a biaxially oriented polypropylene (BOPP) film having a maximal energy density of 5 J/cm(3) and a high breakdown field of 700 MV/m, but with a limited dielectric constant (∼2.2) and a reduced breakdown strength above 85 °C. Great effort has been put into exploring other materials to fulfill the demand of continuous miniaturization and improved functionality. In this work, a series of polyimides were investigated as potential polymer materials for this application. Polyimide with high dielectric constants of up to 7.8 that exhibits low dissipation factors (<1%) and high energy density around 15 J/cm(3), which is 3 times that of BOPP, was prepared. Our syntheses were guided by high-throughput density functional theory calculations for rational design in terms of a high dielectric constant and band gap. Correlations of experimental and theoretical results through judicious variations of polyimide structures allowed for a clear demonstration of the relationship between chemical functionalities and dielectric properties.

  15. Average density and porosity of high-strength lightweight concrete

    Directory of Open Access Journals (Sweden)

    A.S. Inozemtcev

    2014-11-01

    Full Text Available The analysis results of high-strength lightweight concrete (HSLWC structure are presented in this paper. The X-ray tomography, optical microscopy and other methods are used for researching of average density and porosity. It has been revealed that mixtures of HSLWC with density 1300…1500 kg/m3 have a homogeneous structure. The developed concrete has a uniform distribution of the hollow filler and a uniform layer of cement-mineral matrix. The highly saturated gas phase which is divided by denser large particles of quartz sand and products of cement hydration in the contact area allow forming a composite material with low average density, big porosity (up to 40% and high strength (compressive strength is more than 40 MPa. Special modifiers increase adhesion, compacts structure in the contact area, decrease water absorption of high-strength lightweight concrete (up to 1 % and ensure its high water resistance (water resistance coefficient is more than 0.95.

  16. Experimental Research on Permeability of Airbag Fabrics at High Pressure Differential

    Institute of Scientific and Technical Information of China (English)

    WANG Xin-hou

    2004-01-01

    The air permeability of airbag fabrics was measured at high pressure differential up to 200kPa. It was found that permeability varied with pressure differential nonlinearly. The relationship between air permeability and the pressure differential was fitted well with power law curve. The study revealed that the coefficient c and exponent b in the power law equation had a strong correlation with porosity, which was chosen to characterize the airbag fabrics.

  17. High Resolution Magic Angle Spinning Nuclear Magnetic Resonance (HRMAS NMR) for Studies of Reactive Fabrics

    Science.gov (United States)

    2015-11-01

    Magnetic Resonance (HRMAS NMR) for Studies of Reactive Fabrics 5a. CONTRACT NUMBER W911SR-11-C-0047 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER...ECBC-TR-1326 HIGH RESOLUTION MAGIC ANGLE SPINNING NUCLEAR MAGNETIC RESONANCE (HRMAS NMR) FOR STUDIES OF REACTIVE FABRICS David J. McGarvey...unlimited. 13. SUPPLEMENTARY NOTES 14. ABSTRACT An analytical chemistry method is described for measuring the reactivity and permeation of

  18. High power density yeast catalyzed microbial fuel cells

    Science.gov (United States)

    Ganguli, Rahul

    Microbial fuel cells leverage whole cell biocatalysis to convert the energy stored in energy-rich renewable biomolecules such as sugar, directly to electrical energy at high efficiencies. Advantages of the process include ambient temperature operation, operation in natural streams such as wastewater without the need to clean electrodes, minimal balance-of-plant requirements compared to conventional fuel cells, and environmentally friendly operation. These make the technology very attractive as portable power sources and waste-to-energy converters. The principal problem facing the technology is the low power densities compared to other conventional portable power sources such as batteries and traditional fuel cells. In this work we examined the yeast catalyzed microbial fuel cell and developed methods to increase the power density from such fuel cells. A combination of cyclic voltammetry and optical absorption measurements were used to establish significant adsorption of electron mediators by the microbes. Mediator adsorption was demonstrated to be an important limitation in achieving high power densities in yeast-catalyzed microbial fuel cells. Specifically, the power densities are low for the length of time mediator adsorption continues to occur. Once the mediator adsorption stops, the power densities increase. Rotating disk chronoamperometry was used to extract reaction rate information, and a simple kinetic expression was developed for the current observed in the anodic half-cell. Since the rate expression showed that the current was directly related to microbe concentration close to the electrode, methods to increase cell mass attached to the anode was investigated. Electrically biased electrodes were demonstrated to develop biofilm-like layers of the Baker's yeast with a high concentration of cells directly connected to the electrode. The increased cell mass did increase the power density 2 times compared to a non biofilm fuel cell, but the power density

  19. The High Density Region of QCD from an Effective Model

    CERN Document Server

    De Pietri, R; Seiler, E; Stamatescu, I O

    2007-01-01

    We study the high density region of QCD within an effective model obtained in the frame of the hopping parameter expansion and choosing Polyakov-type loops as the main dynamical variables representing the fermionic matter. This model still shows the so-called sign problem, a difficulty peculiar to non-zero chemical potential, but it permits the development of algorithms which ensure a good overlap of the simulated Monte Carlo ensemble with the true one. We review the main features of the model and present results concerning the dependence of various observables on the chemical potential and on the temperature, in particular of the charge density and the Polykov loop susceptibility, which may be used to characterize the various phases expected at high baryonic density. In this way, we obtain information about the phase structure of the model and the corresponding phase transitions and cross over regions, which can be considered as hints about the behaviour of non-zero density QCD.

  20. High Energy Density Regenerative Fuel Cell Systems for Terrestrial Applications

    Science.gov (United States)

    Burke, Kenneth A.

    1999-01-01

    Regenerative Fuel Cell System (RFCS) technology for energy storage has been a NASA power system concept for many years. Compared to battery-based energy storage systems, RFCS has received relatively little attention or resources for development because the energy density and electrical efficiency were not sufficiently attractive relative to advanced battery systems. Even today, RFCS remains at a very low technology readiness level (TRL of about 2 indicating feasibility has been demonstrated). Commercial development of the Proton Exchange Membrane (PEM) fuel cells for automobiles and other terrestrial applications and improvements in lightweight pressure vessel design to reduce weight and improve performance make possible a high energy density RFCS energy storage system. The results from this study of a lightweight RFCS energy storage system for a remotely piloted, solar-powered, high altitude aircraft indicate an energy density up to 790 w-h/kg with electrical efficiency of 53.4% is attainable. Such an energy storage system would allow a solar-powered aircraft to carry hundreds of kilograms of payload and remain in flight indefinitely for use in atmospheric research, earth observation, resource mapping. and telecommunications. Future developments in the areas of hydrogen and oxygen storage, pressure vessel design, higher temperature and higher- pressure fuel cell operation, unitized regenerative fuel cells, and commercial development of fuel cell technology will improve both the energy density and electrical efficiency of the RFCS.

  1. High-density housing that works for all

    Energy Technology Data Exchange (ETDEWEB)

    Hasan, Arif

    2010-03-15

    In an urbanising world, the way people fit into cities is vastly important - socially, economically, environmentally, even psychologically. So density, or the number of people living in a given area, is central to urban design and planning. Both governments and markets tend to get density wrong, leading to overcrowding, urban sprawl or often both. A case in point are the high-rise buildings springing up throughtout urban Asia - perceived as key features of that widely touted concept, the 'world-class city'. While some may offer a viable solution to land pressures and density requirements, many built to house evicted or resettled 'slum' dwellers are a social and economic nightmare - inconveniently sited, overcrowded and costly. New evidence from Karachi, Pakistan, reveals a real alternative. Poor people can create liveable high-density settlements as long as community control, the right technical assistance and flexible designs are in place. A city is surely 'world-class' only when it is cosmopolitan – built to serve all, including the poorest.

  2. Design of High Power Density Amplifiers: Application to Ka Band

    Science.gov (United States)

    Passi, Davide; Leggieri, Alberto; Di Paolo, Franco; Bartocci, Marco; Tafuto, Antonio

    2017-06-01

    Recent developments in the design of high-power-high-frequency amplifiers are assessed in this paper by the analysis and measurements of a high power density amplifier operating in the Ka Band. Design procedure is presented and a technical investigation is reported. The proposed device has shown over 23% of useful frequency bandwidth. It is an ensemble of 16 monolithic solid state power amplifiers that employees mixed technologies as spatial and planar combiners. Test performed have given maximum delivered power of 47.2 dBm.

  3. High energy-density 0.72Pb(Zr0.47Ti0.53)O3-0.28Pb[(Zn0.45Ni0.55)1/3Nb2/3]O3 thick films fabricated by tape casting for energy-harvesting-device applications

    Science.gov (United States)

    Jeon, Chang Jun; Hwang, Ha Na; Jeong, Young Hun; Yun, Ji Sun; Nam, Joong Hee; Cho, Jeong Ho; Paik, Jong Hoo; Lim, Jong Bong; Nahm, Sahn; Kim, Eung Soo

    2013-11-01

    0.72Pb(Zr0.47Ti0.53)O3-0.28Pb[(Zn0.45Ni0.55)1/3Nb2/3]O3 (0.72PZT-0.28PZNN) thick films were prepared by using a tape casting method to develop new materials with high energy-density applicable to energy-harvesting devices. The piezoelectric strain constant ( d 33), dielectric constant ( ɛ {33/ T }/ ɛ 0), piezoelectric voltage constant ( g 33) and transduction coefficient ( d 33· g 33) of the films were affected by the sintering temperature. These results could be attributed to the crystal structure, microstructures and secondary phases. However, the dielectric loss (tan δ) of the films was not changed remarkably with increasing sintering temperature. Typically, a d 33 of 452 pC/N, ɛ {33/ T }/ ɛ 0 of 1444, d 33· g 33 of 20,340 × 10-15 m2/N and tan δ of 0.15% were obtained for the films sintered at 1050 °C for 1 h. The power generation performance of the piezoelectric unimorph cantilever was assessed to demonstrate the feasibility of the 0.72PZT-0.28PZNN piezoelectric thick film. Also, theoretical models were employed to predict the resonance frequency of the unimorph cantilever generator, and the predicted values were compared with experimental data.

  4. Design, Simulation and Fabrication of Triaxial MEMS High Shock Accelerometer.

    Science.gov (United States)

    Zhang, Zhenhai; Shi, Zhiguo; Yang, Zhan; Xie, Zhihong; Zhang, Donghong; Cai, De; Li, Kejie; Shen, Yajing

    2015-04-01

    On the basis of analyzing the disadvantage of other structural accelerometer, three-axis high g MEMS piezoresistive accelerometer was put forward in order to apply to the high-shock test field. The accelerometer's structure and working principle were discussed in details. The simulation results show that three-axis high shock MEMS accelerometer can bear high shock. After bearing high shock impact in high-shock shooting test, three-axis high shock MEMS accelerometer can obtain the intact metrical information of the penetration process and still guarantee the accurate precision of measurement in high shock load range, so we can not only analyze the law of stress wave spreading and the penetration rule of the penetration process of the body of the missile, but also furnish the testing technology of the burst point controlling. The accelerometer has far-ranging application in recording the typical data that projectile penetrating hard target and furnish both technology guarantees for penetration rule and defend engineering.

  5. Progress in High Power Density SOFC Material Development for Aerospace Applications

    Science.gov (United States)

    Cable, Thomas L.; Sofie, Stephen W.; Setlock, John A.; Misra, Ajay K.

    2004-01-01

    Solid oxide fuel cell (SOFC) systems for aircraft applications require order of magnitude increase in specific power density and long life under aircraft operating conditions. Advanced SOFC materials and fabrication processes are being developed at NASA GRC to increase specific power density and durability of SOFC cell and stack. Initial research efforts for increasing specific power density are directed toward increasing the operating temperature for the SOFC system and reducing the weight of the stack. While significant research is underway to develop anode supported SOFC system operating at temperatures in the range of 650 - 850 C for ground power generation applications, such temperatures may not yield the power densities required for aircraft applications. For electrode-supported cells, SOFC stacks with power densities greater than 1.0 W/sq cm are favorable at temperatures in excess of 900 C. The performance of various commercial and developmental anode supported cells is currently being evaluated in the temperature range of 900 to 1000 C to assess the performance gains and materials reliability. The results from these studies will be presented. Since metal interconnects developed for lower temperature operation are not practical at these high temperatures, advanced perovskite based ceramic interconnects with high electronic conductivity and lower sintering temperatures are being developed. Another option for increasing specific power density of SOFC stacks is to decrease the stack weight. Since the interconnect contributes to a significant portion of the stack weight, considerable weight benefits can be derived by decreasing its thickness. Eliminating the gas channels in the interconnect by engineering the pore structure in both anode and cathode can offer significant reduction in thickness of the ceramic interconnect material. New solid oxide fuel cells are being developed with porous engineered electrode supported structures with a 10 - 20 micron thin

  6. Fabrication of High Strength and Ductile Stainless Steel Fiber Felts by Sintering

    Science.gov (United States)

    Wang, J. Z.; Tang, H. P.; Qian, M.; Li, A. J.; Ma, J.; Xu, Z. G.; Li, C. L.; Liu, Y.; Wang, Y.

    2016-03-01

    Stainless steel fiber felts are important porous stainless steel products for a variety of industry applications. A systematic study of the sintering of 28- µm stainless steel fibers has been conducted for the first time, assisted with synchrotron radiation experiments to understand the evolution of the sintered joints. The critical sintering conditions for the formation of bamboo-like grain structures in the fiber ligaments were identified. The evolution of the number density of the sintered joints and the average sintered neck radius during sintering was assessed based on synchrotron radiation experiments. The optimum sintering condition for the fabrication of high strength and ductile 28- µm-diameter stainless steel fiber felts was determined to be sintering at 1000°C for 900 s. Sintering under this optimum condition increased the tensile strength of the as-sintered stainless steel fiber felts by 50% compared to conventional sintering (1200°C for 7200 s), in addition to much reduced sintering cycle and energy consumption.

  7. The use of low density high accuracy (LDHA) data for correction of high density low accuracy (HDLA) point cloud

    Science.gov (United States)

    Rak, Michal Bartosz; Wozniak, Adam; Mayer, J. R. R.

    2016-06-01

    Coordinate measuring techniques rely on computer processing of coordinate values of points gathered from physical surfaces using contact or non-contact methods. Contact measurements are characterized by low density and high accuracy. On the other hand optical methods gather high density data of the whole object in a short time but with accuracy at least one order of magnitude lower than for contact measurements. Thus the drawback of contact methods is low density of data, while for non-contact methods it is low accuracy. In this paper a method for fusion of data from two measurements of fundamentally different nature: high density low accuracy (HDLA) and low density high accuracy (LDHA) is presented to overcome the limitations of both measuring methods. In the proposed method the concept of virtual markers is used to find a representation of pairs of corresponding characteristic points in both sets of data. In each pair the coordinates of the point from contact measurements is treated as a reference for the corresponding point from non-contact measurement. Transformation enabling displacement of characteristic points from optical measurement to their match from contact measurements is determined and applied to the whole point cloud. The efficiency of the proposed algorithm was evaluated by comparison with data from a coordinate measuring machine (CMM). Three surfaces were used for this evaluation: plane, turbine blade and engine cover. For the planar surface the achieved improvement was of around 200 μm. Similar results were obtained for the turbine blade but for the engine cover the improvement was smaller. For both freeform surfaces the improvement was higher for raw data than for data after creation of mesh of triangles.

  8. A Tale of Two Electrons: Correlation at High Density

    CERN Document Server

    Loos, Pierre-François

    2010-01-01

    We review our recent progress in the determination of the high-density correlation energy $\\Ec$ in two-electron systems. Several two-electron systems are considered, such as the well known helium-like ions (helium), and the Hooke's law atom (hookium). We also present results regarding two electrons on the surface of a sphere (spherium), and two electrons trapped in a spherical box (ballium). We also show that, in the large-dimension limit, the high-density correlation energy of two opposite-spin electrons interacting {\\em via} a Coulomb potential is given by $\\Ec \\sim -1/(8D^2)$ for any radial external potential $V(r)$, where $D$ is the dimensionality of the space. This result explains the similarity of $\\Ec$ in the previous two-electron systems for $D=3$.

  9. Lithium-Based High Energy Density Flow Batteries

    Science.gov (United States)

    Bugga, Ratnakumar V. (Inventor); West, William C. (Inventor); Kindler, Andrew (Inventor); Smart, Marshall C. (Inventor)

    2014-01-01

    Systems and methods in accordance with embodiments of the invention implement a lithium-based high energy density flow battery. In one embodiment, a lithium-based high energy density flow battery includes a first anodic conductive solution that includes a lithium polyaromatic hydrocarbon complex dissolved in a solvent, a second cathodic conductive solution that includes a cathodic complex dissolved in a solvent, a solid lithium ion conductor disposed so as to separate the first solution from the second solution, such that the first conductive solution, the second conductive solution, and the solid lithium ionic conductor define a circuit, where when the circuit is closed, lithium from the lithium polyaromatic hydrocarbon complex in the first conductive solution dissociates from the lithium polyaromatic hydrocarbon complex, migrates through the solid lithium ionic conductor, and associates with the cathodic complex of the second conductive solution, and a current is generated.

  10. High energy density capacitor testing for the AFWL SHIVA

    Science.gov (United States)

    Smith, D. L.; Reinovsky, R. E.

    Lifetime testing and analysis of small samples of high energy density (HED) discharge capacitors at the AFWL were conducted to find a component suitable for upgrading the SHIVA capacitor bank to a 6 MJ facility. Evaluation was performed with discharge conditions of approximately 250 kA per capacitor at 60 to 70% reversal and 2 microsec quarter period. Dielectric systems including Kraft paper with caster oil impregnant and Kraft paper, polypropylene with DiOctyl Phthalate (DOP) impregnant were tested.

  11. Polypropylene-(high density polyethylene) precipitation from stirred solutions

    OpenAIRE

    Esperidião,Maria Cecília Azevedo; Galembeck,Fernando

    1993-01-01

    Texto completo: acesso restrito. p.993–997 The fast precipitation of mixtures of polypropylene (PP) with high density polyethylene (HDPE) from decalin solutions is affected by the stirring rate of the solutions. With fast stirring, two types of precipitates were obtained viz. globules dispersed in the liquid phase and fibres adhering to the stirrer. Studies by i.r., WAXD, DSC and optical microscopy indicated that the fibrous precipitate is more birefringent, richer in HDPE and richer in th...

  12. Flexible and Lightweight Fuel Cell with High Specific Power Density.

    Science.gov (United States)

    Ning, Fandi; He, Xudong; Shen, Yangbin; Jin, Hehua; Li, Qingwen; Li, Da; Li, Shuping; Zhan, Yulu; Du, Ying; Jiang, Jingjing; Yang, Hui; Zhou, Xiaochun

    2017-06-27

    Flexible devices have been attracting great attention recently due to their numerous advantages. But the energy densities of current energy sources are still not high enough to support flexible devices for a satisfactory length of time. Although proton exchange membrane fuel cells (PEMFCs) do have a high-energy density, traditional PEMFCs are usually too heavy, rigid, and bulky to be used in flexible devices. In this research, we successfully invented a light and flexible air-breathing PEMFC by using a new design of PEMFC and a flexible composite electrode. The flexible air-breathing PEMFC with 1 × 1 cm(2) working area can be as light as 0.065 g and as thin as 0.22 mm. This new PEMFC exhibits an amazing specific volume power density as high as 5190 W L(-1), which is much higher than traditional (air-breathing) PEMFCs. Also outstanding is that the flexible PEMFC retains 89.1% of its original performance after being bent 600 times, and it retains its original performance after being dropped five times from a height of 30 m. Moreover, the research has demonstrated that when stacked, the flexible PEMFCs are also useful in mobile applications such as mobile phones. Therefore, our research shows that PEMFCs can be made light, flexible, and suitable for applications in flexible devices. These innovative flexible PEMFCs may also notably advance the progress in the PEMFC field, because flexible PEMFCs can achieve high specific power density with small size, small volume, low weight, and much lower cost; they are also much easier to mass produce.

  13. Anti-Ferroelectric Ceramics for High Energy Density Capacitors

    Directory of Open Access Journals (Sweden)

    Aditya Chauhan

    2015-11-01

    Full Text Available With an ever increasing dependence on electrical energy for powering modern equipment and electronics, research is focused on the development of efficient methods for the generation, storage and distribution of electrical power. In this regard, the development of suitable dielectric based solid-state capacitors will play a key role in revolutionizing modern day electronic and electrical devices. Among the popular dielectric materials, anti-ferroelectrics (AFE display evidence of being a strong contender for future ceramic capacitors. AFE materials possess low dielectric loss, low coercive field, low remnant polarization, high energy density, high material efficiency, and fast discharge rates; all of these characteristics makes AFE materials a lucrative research direction. However, despite the evident advantages, there have only been limited attempts to develop this area. This article attempts to provide a focus to this area by presenting a timely review on the topic, on the relevant scientific advancements that have been made with respect to utilization and development of anti-ferroelectric materials for electric energy storage applications. The article begins with a general introduction discussing the need for high energy density capacitors, the present solutions being used to address this problem, and a brief discussion of various advantages of anti-ferroelectric materials for high energy storage applications. This is followed by a general description of anti-ferroelectricity and important anti-ferroelectric materials. The remainder of the paper is divided into two subsections, the first of which presents various physical routes for enhancing the energy storage density while the latter section describes chemical routes for enhanced storage density. This is followed by conclusions and future prospects and challenges which need to be addressed in this particular field.

  14. High power density self-cooled lithium-vanadium blanket.

    Energy Technology Data Exchange (ETDEWEB)

    Gohar, Y.; Majumdar, S.; Smith, D.

    1999-07-01

    A self-cooled lithium-vanadium blanket concept capable of operating with 2 MW/m{sup 2} surface heat flux and 10 MW/m{sup 2} neutron wall loading has been developed. The blanket has liquid lithium as the tritium breeder and the coolant to alleviate issues of coolant breeder compatibility and reactivity. Vanadium alloy (V-4Cr-4Ti) is used as the structural material because it can accommodate high heat loads. Also, it has good mechanical properties at high temperatures, high neutron fluence capability, low degradation under neutron irradiation, good compatibility with the blanket materials, low decay heat, low waste disposal rating, and adequate strength to accommodate the electromagnetic loads during plasma disruption events. Self-healing electrical insulator (CaO) is utilized to reduce the MHD pressure drop. A poloidal coolant flow with high velocity at the first wall is used to reduce the peak temperature of the vanadium structure and to accommodate high surface heat flux. The blanket has a simple blanket configuration and low coolant pressure to reduce the fabrication cost, to improve the blanket reliability, and to increase confidence in the blanket performance. Spectral shifter, moderator, and reflector are utilized to improve the blanket shielding capability and energy multiplication, and to reduce the radial blanket thickness. Natural lithium is used to avoid extra cost related to the lithium enrichment process.

  15. High power density self-cooled lithium-vanadium blanket.

    Energy Technology Data Exchange (ETDEWEB)

    Gohar, Y.; Majumdar, S.; Smith, D.

    1999-07-01

    A self-cooled lithium-vanadium blanket concept capable of operating with 2 MW/m{sup 2} surface heat flux and 10 MW/m{sup 2} neutron wall loading has been developed. The blanket has liquid lithium as the tritium breeder and the coolant to alleviate issues of coolant breeder compatibility and reactivity. Vanadium alloy (V-4Cr-4Ti) is used as the structural material because it can accommodate high heat loads. Also, it has good mechanical properties at high temperatures, high neutron fluence capability, low degradation under neutron irradiation, good compatibility with the blanket materials, low decay heat, low waste disposal rating, and adequate strength to accommodate the electromagnetic loads during plasma disruption events. Self-healing electrical insulator (CaO) is utilized to reduce the MHD pressure drop. A poloidal coolant flow with high velocity at the first wall is used to reduce the peak temperature of the vanadium structure and to accommodate high surface heat flux. The blanket has a simple blanket configuration and low coolant pressure to reduce the fabrication cost, to improve the blanket reliability, and to increase confidence in the blanket performance. Spectral shifter, moderator, and reflector are utilized to improve the blanket shielding capability and energy multiplication, and to reduce the radial blanket thickness. Natural lithium is used to avoid extra cost related to the lithium enrichment process.

  16. Nanostructured thin solid oxide fuel cells with high power density.

    Science.gov (United States)

    Ignatiev, Alex; Chen, Xin; Wu, Naijuan; Lu, Zigui; Smith, Laverne

    2008-10-28

    Nanostructured thin film solid oxide fuel cells (SOFC) have been developed for reduced temperature operation, with high power density, and to be self reforming. A thin film electrolyte (1-2 microm thickness), e.g., yttria-stabilized zirconia (YSZ), is deposited on a nickel foil substrate. The electrolyte thin film is polycrystalline when deposited on a polycrystalline nickel foil substrate, and is (100) textured when deposited on an atomically textured nickel foil substrate. The Ni foil substrate is then converted into a porous SOFC anode by photolithographic patterning and etching to develop porosity. A composite La(0.5)Sr(0.5)CoO(3) cathode is then deposited on the thin film electrolyte. The resultant thin film hetero structure fuel cells have operated at a significantly reduced temperature: as low as 470 degrees C, with a maximum power density of 140 mW cm(-2) at 575 degrees C, and an efficiency of >50%. This drastic reduction in operating temperature for an SOFC now also allows for the use of hydrocarbon fuels without the need for a separate reformer as the nickel anode effectively dissociates hydrocarbons within this temperature range. These nanostructured fuel cells show excellent potential for high power density, small volume, high efficiency fuel cells for power generation applications.

  17. High Energy Density Physics and Exotic Acceleration Schemes

    Energy Technology Data Exchange (ETDEWEB)

    Cowan, T.; /General Atomics, San Diego; Colby, E.; /SLAC

    2005-09-27

    The High Energy Density and Exotic Acceleration working group took as our goal to reach beyond the community of plasma accelerator research with its applications to high energy physics, to promote exchange with other disciplines which are challenged by related and demanding beam physics issues. The scope of the group was to cover particle acceleration and beam transport that, unlike other groups at AAC, are not mediated by plasmas or by electromagnetic structures. At this Workshop, we saw an impressive advancement from years past in the area of Vacuum Acceleration, for example with the LEAP experiment at Stanford. And we saw an influx of exciting new beam physics topics involving particle propagation inside of solid-density plasmas or at extremely high charge density, particularly in the areas of laser acceleration of ions, and extreme beams for fusion energy research, including Heavy-ion Inertial Fusion beam physics. One example of the importance and extreme nature of beam physics in HED research is the requirement in the Fast Ignitor scheme of inertial fusion to heat a compressed DT fusion pellet to keV temperatures by injection of laser-driven electron or ion beams of giga-Amp current. Even in modest experiments presently being performed on the laser-acceleration of ions from solids, mega-amp currents of MeV electrons must be transported through solid foils, requiring almost complete return current neutralization, and giving rise to a wide variety of beam-plasma instabilities. As keynote talks our group promoted Ion Acceleration (plenary talk by A. MacKinnon), which historically has grown out of inertial fusion research, and HIF Accelerator Research (invited talk by A. Friedman), which will require impressive advancements in space-charge-limited ion beam physics and in understanding the generation and transport of neutralized ion beams. A unifying aspect of High Energy Density applications was the physics of particle beams inside of solids, which is proving to

  18. Fabrication of high performance 3D SiO2/Si3N4 composite via perhydropolysilazane infiltration and pyrolysis

    Institute of Scientific and Technical Information of China (English)

    QI; Gongjin; ZHANG; Changrui; HU; Haifeng; CAO; Feng; WANG

    2005-01-01

    Perhydropolysilazane, a low viscosity preceramic polymer with good wettability and high char yield, was used to fabricate three-dimensional silica fiber reinforced silicon nitride matrix composites through the repeated infiltration-curing- pyrolysis cycles. With the increase of the pyrolysis temperature from T1, T2 to T3, the density of the composites increased all through, but the flexural strength showed a maximum value at T2 followed by a sharp decrease. The composite prepared at T2 exhibited a good ceramization of the preceramic polymer, a high flexural strength of 144.9 MPa and excellent dielectric property. The high performance of the composite resulted from the good state of the silica fibers, controlled fiber/matrix interfacial microstructures and high-purity dense silicon nitride matrix.

  19. Preclinical Study for Application of Fabricated High Activity Ir-192

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Mi Son; Kang, Seung Hee; Oh, Young Taek; Jeong, Chul; Kim, Mi Hwa; Hwang, Jeong Hye; Kim, Hee Seong; Im, Eun Jeong [Ajou University, Suwon (Korea, Republic of)

    2005-10-15

    This study was performed to evaluate the feasibility and safety of high activity Ir-192 sources manufactured by KAERI(Korea Atomic Energy Research Institute) for application to present equipment such as various applicators inserted to patients and PLATO(Nucletron, Netherland) of treatment planning system and to evaluate safety and accuracy of Ir-192 as practical clinic use through in vitro dosimetry of Ir-192. We confirmed the physical and radiobiological safety of KAERI sources to use practical. KAERI sources are applicable to commercial high dose rate brachytherapy machine safely. Then those can be substituted for the imported sources such as sources made by Nucletron, Gammamed and exported to the foreign country

  20. Fabrication of high gradient insulators by stack compression

    Energy Technology Data Exchange (ETDEWEB)

    Harris, John Richardson; Sanders, Dave; Hawkins, Steven Anthony; Norona, Marcelo

    2014-04-29

    Individual layers of a high gradient insulator (HGI) are first pre-cut to their final dimensions. The pre-cut layers are then stacked to form an assembly that is subsequently pressed into an HGI unit with the desired dimension. The individual layers are stacked, and alignment is maintained, using a sacrificial alignment tube that is removed after the stack is hot pressed. The HGI's are used as high voltage vacuum insulators in energy storage and transmission structures or devices, e.g. in particle accelerators and pulsed power systems.

  1. High energy density Z-pinch plasmas using flow stabilization

    Energy Technology Data Exchange (ETDEWEB)

    Shumlak, U., E-mail: shumlak@uw.edu; Golingo, R. P., E-mail: shumlak@uw.edu; Nelson, B. A., E-mail: shumlak@uw.edu; Bowers, C. A., E-mail: shumlak@uw.edu; Doty, S. A., E-mail: shumlak@uw.edu; Forbes, E. G., E-mail: shumlak@uw.edu; Hughes, M. C., E-mail: shumlak@uw.edu; Kim, B., E-mail: shumlak@uw.edu; Knecht, S. D., E-mail: shumlak@uw.edu; Lambert, K. K., E-mail: shumlak@uw.edu; Lowrie, W., E-mail: shumlak@uw.edu; Ross, M. P., E-mail: shumlak@uw.edu; Weed, J. R., E-mail: shumlak@uw.edu [Aerospace and Energetics Research Program, University of Washington, Seattle, Washington, 98195-2250 (United States)

    2014-12-15

    The ZaP Flow Z-Pinch research project[1] at the University of Washington investigates the effect of sheared flows on MHD instabilities. Axially flowing Z-pinch plasmas are produced that are 100 cm long with a 1 cm radius. The plasma remains quiescent for many radial Alfvén times and axial flow times. The quiescent periods are characterized by low magnetic mode activity measured at several locations along the plasma column and by stationary visible plasma emission. Plasma evolution is modeled with high-resolution simulation codes – Mach2, WARPX, NIMROD, and HiFi. Plasma flow profiles are experimentally measured with a multi-chord ion Doppler spectrometer. A sheared flow profile is observed to be coincident with the quiescent period, and is consistent with classical plasma viscosity. Equilibrium is determined by diagnostic measurements: interferometry for density; spectroscopy for ion temperature, plasma flow, and density[2]; Thomson scattering for electron temperature; Zeeman splitting for internal magnetic field measurements[3]; and fast framing photography for global structure. Wall stabilization has been investigated computationally and experimentally by removing 70% of the surrounding conducting wall to demonstrate no change in stability behavior.[4] Experimental evidence suggests that the plasma lifetime is only limited by plasma supply and current waveform. The flow Z-pinch concept provides an approach to achieve high energy density plasmas,[5] which are large, easy to diagnose, and persist for extended durations. A new experiment, ZaP-HD, has been built to investigate this approach by separating the flow Z-pinch formation from the radial compression using a triaxial-electrode configuration. This innovation allows more detailed investigations of the sheared flow stabilizing effect, and it allows compression to much higher densities than previously achieved on ZaP by reducing the linear density and increasing the pinch current. Experimental results and

  2. Hydrodynamic Instabilities in High-Energy-Density Settings

    Science.gov (United States)

    Smalyuk, Vladimir

    2016-10-01

    Our understanding of hydrodynamic instabilities, such as the Rayleigh-Taylor (RT), Richtmyer-Meshkov (RM), and Kelvin-Helmholtz (KH) instabilities, in high-energy-density (HED) settings over past two decades has progressed enormously. The range of conditions where hydrodynamic instabilities are experimentally observed now includes direct and indirect drive inertial confinement fusion (ICF) where surprises continue to emerge, linear and nonlinear regimes, classical interfaces vs. stabilized ablation fronts, tenuous ideal plasmas vs. high density Fermi degenerate plasmas, bulk fluid interpenetration vs. mixing down to the atomic level, in the presence of magnetic fields and/or intense radiation, and in solid state plastic flow at high pressures and strain rates. Regimes in ICF can involve extreme conditions of matter with temperatures up to kilovolts, densities of a thousand times solid densities, and time scales of nanoseconds. On the other hand, scaled conditions can be generated that map to exploding stars (supernovae) with length and time scales of millions of kilometers and hours to days or even years of instability evolution, planetary formation dynamics involving solid-state plastic flow which severely modifies the RT growth and continues to challenge reliable theoretical descriptions. This review will look broadly at progress in probing and understanding hydrodynamic instabilities in these very diverse HED settings, and then will examine a few cases in more depth to illustrate the detailed science involved. Experimental results on large-scale HED facilities such as the Omega, Nike, Gekko, and Shenguang lasers will be reviewed and the latest developments at the National Ignition Facility (NIF) and Z machine will be covered. Finally, current overarching questions and challenges will be summarized to motivate research directions for future. This work was performed under the auspices of the U.S. Department of Energy by LLNL under Contract DE-AC52-07NA27344.

  3. High power density reactors based on direct cooled particle beds

    Science.gov (United States)

    Powell, J. R.; Horn, F. L.

    Reactors based on direct cooled High Temperature Gas Cooled Reactor (HTGR) type particle fuel are described. The small diameter particle fuel is packed between concentric porous cylinders to make annular fuel elements, with the inlet coolant gas flowing inwards. Hot exit gas flows out along the central channel of each element. Because of the very large heat transfer area in the packed beds, power densities in particle bed reactors (PBRs) are extremely high resulting in compact, lightweight systems. Coolant exit temperatures are high, because of the ceramic fuel temperature capabilities, and the reactors can be ramped to full power and temperature very rapidly. PBR systems can generate very high burst power levels using open cycle hydrogen coolant, or high continuous powers using closed cycle helium coolant. PBR technology is described and development requirements assessed.

  4. High Efficiency UV Photodiodes fabricated on p-type Substrate

    NARCIS (Netherlands)

    Ramachandra Rao, P.; Milosavljevic, S.; Kroth, U.; Laubis, C.; Nihtianov, S.

    2014-01-01

    Newly developed “pure-boron” photodiodes, with high sensitivity and stability in the whole ultraviolet range (UV), are described. The main purpose of this work is to create and characterize a large-area UV photodiode, representing a structure of a pixel in a backside illuminated CMOS image sensor, f

  5. High-density cervical ureaplasma urealyticum colonization in pregnant women

    Directory of Open Access Journals (Sweden)

    Ranđelović Gordana

    2006-01-01

    Full Text Available Background/aim: Ureaplasma urealyticum, a common commensal of the female lower genital tract, has been observed as an important opportunistic pathogen during pregnancy. The aims of this study were to determine the degree of cervical colonization with U. urealyticum in pregnant women with risk pregnancy and in pregnant women with normal term delivery and to evaluate the correlation between high-density cervical U. urealyticum colonization and premature rupture of membranes (PROM as well. Methods. This research was conducted on the samples comprising 130 hospitalized pregnant women with threatening preterm delivery and premature rupture of membranes. The control group consisted of 39 pregnant women with term delivery without PROM. In addition to standard bacteriological examination and performing direct immunofluorescence test to detect Chlamydia trachomatis, cervical swabs were also examined for the presence of U. urealyticum and Mycoplasma hominis by commercially available Mycofast Evolution 2 test (International Microbio, France. Results. The number of findings with isolated high-density U. urealyticum in the target group was 69 (53.08%, while in the control group was 14 (35.90%. Premature rupture of membranes (PROM occurred in 43 (33.08% examinees: 29 were pPROM, and 14 were PROM. The finding of U.urealyticum ≥104 was determined in 25 (58.14% pregnant women with rupture, 17 were pPROM, and 8 were PROM. There was statistically significant difference in the finding of high-density U. urealyticum between the pregnant women with PROM and the control group (χ² = 4.06, p < 0.05. U. urealyticum was predominant bacterial species found in 62.79% of isolates in the PROM cases, while in 32.56% it was isolated alone. Among the 49 pregnant women with preterm delivery, pPROM occurred in 29 (59.18% examinees, and in 70.83% of pregnant women with findings of high-density U. urealyticum pPROM was observed. Conclusion. Cervical colonization with U

  6. High Density Thermal Energy Storage with Supercritical Fluids

    Science.gov (United States)

    Ganapathi, Gani B.; Wirz, Richard

    2012-01-01

    A novel approach to storing thermal energy with supercritical fluids is being investigated, which if successful, promises to transform the way thermal energy is captured and utilized. The use of supercritical fluids allows cost-affordable high-density storage with a combination of latent heat and sensible heat in the two-phase as well as the supercritical state. This technology will enhance penetration of several thermal power generation applications and high temperature water for commercial use if the overall cost of the technology can be demonstrated to be lower than the current state-of-the-art molten salt using sodium nitrate and potassium nitrate eutectic mixtures.

  7. High Current Density and Low Thermal Conductivity of Atomically Thin Semimetallic WTe2.

    Science.gov (United States)

    Mleczko, Michal J; Xu, Runjie Lily; Okabe, Kye; Kuo, Hsueh-Hui; Fisher, Ian R; Wong, H-S Philip; Nishi, Yoshio; Pop, Eric

    2016-08-23

    Two-dimensional (2D) semimetals beyond graphene have been relatively unexplored in the atomically thin limit. Here, we introduce a facile growth mechanism for semimetallic WTe2 crystals and then fabricate few-layer test structures while carefully avoiding degradation from exposure to air. Low-field electrical measurements of 80 nm to 2 μm long devices allow us to separate intrinsic and contact resistance, revealing metallic response in the thinnest encapsulated and stable WTe2 devices studied to date (3-20 layers thick). High-field electrical measurements and electrothermal modeling demonstrate that ultrathin WTe2 can carry remarkably high current density (approaching 50 MA/cm(2), higher than most common interconnect metals) despite a very low thermal conductivity (of the order ∼3 Wm(-1) K(-1)). These results suggest several pathways for air-stable technological viability of this layered semimetal.

  8. Note: Experimental platform for magnetized high-energy-density plasma studies at the omega laser facility.

    Science.gov (United States)

    Fiksel, G; Agliata, A; Barnak, D; Brent, G; Chang, P-Y; Folnsbee, L; Gates, G; Hasset, D; Lonobile, D; Magoon, J; Mastrosimone, D; Shoup, M J; Betti, R

    2015-01-01

    An upgrade of the pulsed magnetic field generator magneto-inertial fusion electrical discharge system [O. Gotchev et al., Rev. Sci. Instrum. 80, 043504 (2009)] is described. The device is used to study magnetized high-energy-density plasma and is capable of producing a pulsed magnetic field of tens of tesla in a volume of a few cubic centimeters. The magnetic field is created by discharging a high-voltage capacitor through a small wire-wound coil. The coil current pulse has a duration of about 1 μs and a peak value of 40 kA. Compared to the original, the updated version has a larger energy storage and improved switching system. In addition, magnetic coils are fabricated using 3-D printing technology which allows for a greater variety of the magnetic field topology.

  9. Note: Experimental platform for magnetized high-energy-density plasma studies at the omega laser facility

    Science.gov (United States)

    Fiksel, G.; Agliata, A.; Barnak, D.; Brent, G.; Chang, P.-Y.; Folnsbee, L.; Gates, G.; Hasset, D.; Lonobile, D.; Magoon, J.; Mastrosimone, D.; Shoup, M. J.; Betti, R.

    2015-01-01

    An upgrade of the pulsed magnetic field generator magneto-inertial fusion electrical discharge system [O. Gotchev et al., Rev. Sci. Instrum. 80, 043504 (2009)] is described. The device is used to study magnetized high-energy-density plasma and is capable of producing a pulsed magnetic field of tens of tesla in a volume of a few cubic centimeters. The magnetic field is created by discharging a high-voltage capacitor through a small wire-wound coil. The coil current pulse has a duration of about 1 μs and a peak value of 40 kA. Compared to the original, the updated version has a larger energy storage and improved switching system. In addition, magnetic coils are fabricated using 3-D printing technology which allows for a greater variety of the magnetic field topology.

  10. High-transparency, self-standable gel-SLIPS fabricated by a facile nanoscale phase separation.

    Science.gov (United States)

    Okada, Issei; Shiratori, Seimei

    2014-02-12

    Slippery liquid-infused porous surfaces (SLIPSs) that were both highly transparent and free-standing (self-standability) were fabricated by an extremely simple process using non-solvent-induced phase separation (NIPS) of a poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP)/di-n-butyl phthalate solution. We call these "Gel-SLIPS" because the porous PVDF-HFP film fabricated using the NIPS process has been used as a gel electrolyte in a lithium-ion battery. In previous reports, SLIPS fabrication required complex processes, high annealing temperatures, and drying. Gel-SLIPS can be fabricated from the adjusted solution and the lubricant at room temperature and pressure in 5 min by squeegee, cast, or dip methods. NIPS is based on a quick phase separation process in situ, and reduction of the surface energy is not required because of the considerable fluorine in PVDF-HFP. Moreover, because of the flexible nanonetwork structure of PVDF-HFP, Gel-SLIPS exhibited self-standability and high transmittance (>87% at 600 nm). Gel-SLIPS is thus highly versatile in terms of the fabrication process and film characteristics.

  11. Areal density optimizations for heat-assisted magnetic recording of high-density media

    Science.gov (United States)

    Vogler, Christoph; Abert, Claas; Bruckner, Florian; Suess, Dieter; Praetorius, Dirk

    2016-06-01

    Heat-assisted magnetic recording (HAMR) is hoped to be the future recording technique for high-density storage devices. Nevertheless, there exist several realization strategies. With a coarse-grained Landau-Lifshitz-Bloch model, we investigate in detail the benefits and disadvantages of a continuous and pulsed laser spot recording of shingled and conventional bit-patterned media. Additionally, we compare single-phase grains and bits having a bilayer structure with graded Curie temperature, consisting of a hard magnetic layer with high TC and a soft magnetic one with low TC, respectively. To describe the whole write process as realistically as possible, a distribution of the grain sizes and Curie temperatures, a displacement jitter of the head, and the bit positions are considered. For all these cases, we calculate bit error rates of various grain patterns, temperatures, and write head positions to optimize the achievable areal storage density. Within our analysis, shingled HAMR with a continuous laser pulse moving over the medium reaches the best results and thus has the highest potential to become the next-generation storage device.

  12. Fabrication of highly modulable fibrous 3D extracellular microenvironments

    KAUST Repository

    Zhang, Xixiang

    2017-06-13

    Three-dimensional (3D) in vitro scaffolds that mimic the irregular fibrous structures of in vivo extracellular matrix (ECM) are critical for many important biological applications. However, structural properties modulation of fibrous 3D scaffolds remains a challenge. Here, we report the first highly modulable 3D fibrous scaffolds self-assembled by high-aspect-ratio (HAR) microfibers. The scaffolds structural properties can be easily tailored to incorporate various physical cues, including geometry, stiffness, heterogeneity and nanotopography. Moreover, the fibrous scaffolds are readily and accurately patterned on desired locations of the substrate. Cell culture exhibits that our scaffolds can elicit strong bidirectional cell-material interactions. Furthermore, a functional disparity between the two-dimensional substrate and our 3D scaffolds is identified by cell spreading and proliferation data. These results prove the potential of the proposed scaffold as a biomimetic extracellular microenvironment for cell study.

  13. Photolithographic Approaches for Fabricating Highly Ordered Nanopatterned Arrays

    Directory of Open Access Journals (Sweden)

    Li Xiaoru

    2008-01-01

    Full Text Available Abstract In this work, we report that large area metal nanowire and polymer nanotube arrays were successfully patterned by photolithographic approach using anodic aluminum oxide (AAO templates. Nanowires were produced by electrochemical deposition, and nanotubes by solution-wetting. The highly ordered patterns of nanowire and nanotube arrays were observed using scanning electron microscopy (SEM and found to stand free on the substrate. The method is expected to play an important role in the application of microdevices in the future.

  14. Path to Efficient Lower Hybrid Current Drive at High Density

    Science.gov (United States)

    Baek, S. G.; Bonoli, P. T.; Brunner, D.; Faust, I.; Labombard, B. L.; Parker, R. R.; Shiraiwa, S.; Wallace, G. M.; Wukitch, S.

    2015-11-01

    Recovery of lower hybrid current drive (LHCD) efficiency at high density was demonstrated on Alcator C-Mod by modifying the scrape-off layer (SOL) plasma. RF probe measurements around the C-Mod tokamak indicate that the LH wave amplitude at the high field side wall significantly attenuates with plasma density. This is interpreted as enhanced collisional loss due to the increase in the SOL density and width. By taking advantage of the narrower SOL width by doubling plasma current to 1.1 MA, it is found that the LH wave amplitude maintains its strength, and an effective current drive is extended to above 1x10e20 m-3. An order of magnitude increase in non-thermal Bremsstrahlung emission is consistent with ray-tracing results which take into account the change of SOL profiles with current. In the coming campaign, a further investigation on the role of the SOL plasma is planned by raising plasma current above 1.1 MA. This will be aided with newly developed RF magnetic loop antennas mounted on a radially movable probe head. This system is expected to intercept the LH resonance cone on the first pass, allowing us to measure radial profiles of both the wave amplitude and dominant parallel wavenumber in the SOL for the first time. These data will be compared with the GENRAY ray-tracing code. Work supported by USDoE awards DE-FC02-99ER54512.

  15. Patterned Platinum Etching Studies in an Argon High Density Plasma

    Science.gov (United States)

    Delprat, Sébastien; Chaker, Mohamed; Margot, Joëlle; Pépin, Henri; Tan, Liang; Smy, Tom

    1998-10-01

    A high-density surface-wave Ar plasma operated in the low pressure regime is used to study pure physical etching characteristics of platinum thin films. The platinum samples are RF biased so as to obtain a maximum DC self-bias voltage of 150 V. The sputter-etching characteristics are investigated as a function of the magnetic field intensity, the self-bias voltage and the gas pressure. At 1 mtorr, the etch rate is found to be a unique linear function of both the self-bias voltage and the ion density, independently of the magnetic field intensity value. However, even though the ion density increases, the etch rate is found to decrease with increasing pressure. In the low pressure regime, etch rates as high as 2000 A/min are obtained with a good selectivity over resist. Without any optimization of the etching process, we were able to etch 0.5 micron Pt trenches, 0.6 micron thick yielding fence-free profiles and sidewall angles (75º) that already meets the present industrial requirements of NVRAM technology.

  16. New fabrication techniques for high dynamic range tunneling sensors

    Science.gov (United States)

    Chang, David T.; Stratton, Fred P.; Kubena, Randall L.; Vickers-Kirby, Deborah J.; Joyce, Richard J.; Schimert, Thomas R.; Gooch, Roland W.

    2000-08-01

    We have developed high dynamic range (105-106 g's) tunneling accelerometers1,2 that may be ideal for smart munitions applications by employing both surface and bulk micromachining processing techniques. The highly miniaturized surface-micromachined devices can be manufactured at very low cost and integrated on chip with the control electronics. Bulk-micromachined devices with Si as the cantilever material should have reduced long-term bias drift as well as better stability at higher temperatures. Fully integrated sensors may provide advantages in minimizing microphonics for high-g applications. Previously, we described initial test results using electrostatic forces generated by a self-test electrode located under a Au cantilever3. In this paper, we describe more recent testing of Ni and Au cantilever devices on a shaker table using a novel, low input voltage (5 V) servo controller on both printed wiring board and surface-mount control circuitry. In addition, we report our initial test results for devices packaged using a low-temperature wafer-level vacuum packaging technique for low-cost manufacturing.

  17. Fabrication of interconnected microporous biomaterials with high hydroxyapatite nanoparticle loading

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Wei; Yao Donggang [School of Polymer Textile and Fiber Engineering, Georgia Institute of Technology, Atlanta, GA (United States); Zhang Qingwei; Lelkes, Peter I [School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA 19104 (United States); Zhou, Jack G, E-mail: yao@gatech.ed [Department of Mechanical Engineering and Mechanics, Drexel University, Philadelphia, PA 19104 (United States)

    2010-09-15

    Hydroxyapatite (HA) is known to promote osteogenicity and enhance the mechanical properties of biopolymers. However, incorporating a large amount of HA into a porous biopolymer still remains a challenge. In the present work, a new method was developed to produce interconnected microporous poly(glycolic-co-lactic acid) (PLGA) with high HA nanoparticle loading. First, a ternary blend comprising PLGA/PS (polystyrene)/HA (40/40/20 wt%) was prepared by melt blending under conditions for formation of a co-continuous phase structure. Next, a dynamic annealing stage under small-strain oscillation was applied to the blend to facilitate nanoparticle redistribution. Finally, the PS phase was sacrificially extracted, leaving a porous matrix. The results from different characterizations suggested that the applied small-strain oscillation substantially accelerated the migration of HA nanoparticles during annealing from the PS phase to the PLGA phase; nearly all HA particles were uniformly presented in the PLGA phase after a short period of annealing. After dissolution of the PS phase, a PLGA material with interconnected microporous structure was successfully produced, with a high HA loading above 30 wt%. The mechanisms beneath the experimental observations, particularly on the enhanced particle migration process, were discussed, and strategies for producing highly particle loaded biopolymers with interconnected microporous structures were proposed.

  18. Fabrication of the high power input coupler for BEPCⅡ superconducting cavities

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The BEPCII storage ring adopts two 500 MHz superconducting cavities (SCC). Each one is equipped with a 500 MHz input power coupler. The coupler is to feed 150 kW power in continuous wave (CW) mode with both standing and traveling wave modes. Due to high power feeding and high frequency of the coupler, its fabrication is a big challenge. The fabrication started with two key components, the window and the antenna. Up to now, two sets including windows and antennas have beam made by IHEP. And a 270 kW RF power in CW has passed through the coupler during the high power test. The fabrication details are presented in this paper.

  19. High frequency PMN-PT single crystal focusing transducer fabricated by a mechanical dimpling technique.

    Science.gov (United States)

    Chen, Y; Lam, K H; Zhou, D; Cheng, W F; Dai, J Y; Luo, H S; Chan, H L W

    2013-02-01

    High frequency (∼30MHz and ∼80MHz) focusing ultrasound transducers were fabricated using a PMN-0.28PT single crystal by a mechanical dimpling technique. The dimpled single crystal was used as an active element for the focusing transducer. Compared with a plane transducer, the focusing transducer fabricated with a dimpled active element exhibits much broader bandwidth and higher sensitivity. Besides, a high quality image can be obtained by the 30MHz focusing transducer, in which the -6dB axial and lateral resolution is 27μm and 139μm, respectively. These results prove that the dimpling technique is capable to fabricate the high frequency focusing transducers with excellent performance for imaging applications.

  20. High short-circuit current density CdTe solar cells using all-electrodeposited semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Echendu, O.K., E-mail: oechendu@yahoo.com; Fauzi, F.; Weerasinghe, A.R.; Dharmadasa, I.M.

    2014-04-01

    CdS/CdTe and ZnS/CdTe n–n heterojunction solar cells have been fabricated using all-electrodeposited semiconductors. The best devices show remarkable high short-circuit current densities of 38.5 mAcm{sup −2} and 47.8 mAcm{sup −2}, open-circuit voltages of 630 mV and 646 mV and conversion efficiencies of 8.0% and 12.0% respectively. The major strength of these device structures lies in the combination of n–n heterojunction with a large Schottky barrier at the n-CdTe/metal back contact which provides the required band bending for the separation of photo-generated charge carriers. This is in addition to the use of a high quality n-type CdTe absorber layer with high electron mobility. The potential barrier heights estimated for these devices from the current–voltage characteristics exceed 1.09 eV and 1.13 eV for CdS/CdTe and ZnS/CdTe cells respectively. The diode rectification factors of both devices are in excess of four orders of magnitude with reverse saturation current densities of 1.0 × 10{sup −7} Acm{sup −2} and 4.0 × 10{sup −7} Acm{sup −2} respectively. These all-electrodeposited solar cell device structures are currently being studied and developed as an alternative to the well-known p–n junction structures which utilise chemical bath-deposited CdS. The preliminary material growth, device fabrication and assessment results are presented in this paper. - Highlights: • Two-electrode deposition. • High J{sub sc} Schottky barrier solar cells. • CdCl{sub 2} + CdF{sub 2} treatment.

  1. Femtosecond laser fabrication of highly hydrophobic stainless steel surface with hierarchical structures fabricated by combining ordered microstructures and LIPSS

    Science.gov (United States)

    Martínez-Calderon, M.; Rodríguez, A.; Dias-Ponte, A.; Morant-Miñana, M. C.; Gómez-Aranzadi, M.; Olaizola, S. M.

    2016-06-01

    In this work we have developed hierarchical structures that consist of micro-patterned surfaces covered by nanostructures with a femtosecond laser. The first part of this work is a study to determine the microscale modifications produced on a stainless steel alloy (AISI304) surface at high pulse energy, different velocities, and number of overscans in order to obtain microstructures with a selected depth of around 10 μm and line widths of 20 μm. The second part of the work is focused on finding the optimal irradiation parameters to obtain the nanostructure pattern. Nanostructures have been defined by means of Laser Induced Periodical Surface Structures (LIPSS) around 250 nm high and a period of 580 nm, which constitute the nanostructure pattern. Finally, dual scale gratings of 50 mm2 were fabricated with different geometries and their effect on the measured contact angle. Combining the micro-pattern with the LIPSS nano-pattern, highly hydrophobic surfaces have been developed with measured static contact angles higher than 150° on a stainless steel alloy.

  2. High-Energy-Density Poly(styrene-co-acrylonitrile) Thin Films

    Science.gov (United States)

    Wen, Fei; Xu, Zhuo; Xia, Weimin; Ye, Hongjun; Wei, Xiaoyong; Zhang, Zhicheng

    2013-12-01

    The dielectric response of poly(styrene-co-acrylonitrile) (PSAN) thin films fabricated by a solution casting process was investigated in this work. Linear dielectric behavior was obtained in PSAN films under an electric field at frequencies from 100 Hz to 1 MHz and temperature of -50°C to 100°C. The polymer films exhibited an intermediate dielectric permittivity of 4 and low dielectric loss (tan δ) of 0.027. Under 400 MV/m, the energy density of the PSAN films was 6.8 J/cm3, which is three times higher than that of biaxially oriented polypropylene (BOPP) (about 1.6 J/cm3). However, their charge-discharge efficiency (about 90%) was rather close to that of BOPP. The calculated effective dielectric permittivity of the PSAN films under high electric field was as high as 9, which may be attributed to the improved displacement of the cyanide groups (-CN) polarized at high electric fields. These high-performance features make PSAN attractive for high-energy-density capacitor applications.

  3. High Power Density Power Electronic Converters for Large Wind Turbines

    DEFF Research Database (Denmark)

    Senturk, Osman Selcuk

    In large wind turbines (in MW and multi-MW ranges), which are extensively utilized in wind power plants, full-scale medium voltage (MV) multi-level (ML) voltage source converters (VSCs) are being more preferably employed nowadays for interfacing these wind turbines with electricity grids...... assessments of these specific VSCs so that their power densities and reliabilities are quantitatively determined, which requires extensive utilization of the electro-thermal models of the VSCs under investigation. In this thesis, the three-level neutral-point-clamped VSCs (3L-NPC-VSCs), which are classified......-HB-VSCs). As the switch technology for realizing these 3L-VSCs, press-pack IGBTs are chosen to ensure high power density and reliability. Based on the selected 3L-VSCs and switch technology, the converter electro-thermal models are developed comprehensively, implemented practically, and validated via a full-scale 3L...

  4. Highly smooth Nb surfaces fabricated by buffered electropolishing

    Energy Technology Data Exchange (ETDEWEB)

    Andy T. Wu; John Mammossor; H. Phillips; Jean Delayen; Charles Reece; Amy Wilkerson; David Smith; Robert Ike

    2005-05-01

    It is demonstrated that highly smooth Nb surfaces can be obtained through Buffered ElectroPolishing (BEP) employing an electrolyte consisting of lactic, sulfuric, and hydrofluoric acids. Parameters that control the polishing process are optimized to achieve the smoothest surface finish with the help of surface observations using a scanning electron microscope and a Metallographic Optical Microscope (MOM). The polishing rate of BEP is determined to be 0.646 {micro}m/min that is much higher than 0.381 {micro}m/min achieved by the conventional ElectroPolishing (EP) process widely used in the Superconducting Radio Frequency (SRF) community. A high precision and large scan area 3-D profilometer is used to view morphology of the treated Nb surfaces. Statistical data, such as, rms, total indicator runout, and arithmetic mean deviation of the Nb surfaces are extracted from the profilometer images. It is found that Nb surfaces treated by BEP are an order of magnitude smoother than those treated by the optimized EP process. The chemical composition of the Nb surfaces after BEP is analyzed by static and dynamic Secondary Ion Mass Spectrometer (SIMS) systems. Cracking patterns of the Nb surfaces under different primary ion sources of Ga{sup +}, Au{sup +}, and Ar{sup +} are reported. The depth profile of the surface niobium oxides is studied through continuously monitoring niobium and its relevant oxides' peaks as a function of time. Dynamic SIMS results imply that the surface oxide structure of Nb may be more complicated than what usually believed and can be inhomogeneous. Preliminary results of BEP on Nb SRF single cell cavities and half-cells are reported. It is shown that smooth and bright surfaces can be obtained in 30 minutes when the electric field inside a SRF cavity is uniform during a BEP process. This study reveals that BEP is a highly promising technique for surface treatment on Nb SRF cavities to be used in particle accelerators.

  5. High torque DC motor fabrication and test program

    Science.gov (United States)

    Makus, P.

    1976-01-01

    The testing of a standard iron and standard alnico permanent magnet two-phase, brushless dc spin motor for potential application to the space telescope has been concluded. The purpose of this study was to determine spin motor power losses, magnetic drag, efficiency and torque speed characteristics of a high torque dc motor. The motor was designed and built to fit an existing reaction wheel as a test vehicle and to use existing brass-board commutation and torque command electronics. The results of the tests are included in this report.

  6. Toward Low-Cost, High-Energy Density, and High-Power Density Lithium-Ion Batteries

    Science.gov (United States)

    Li, Jianlin; Du, Zhijia; Ruther, Rose E.; AN, Seong Jin; David, Lamuel Abraham; Hays, Kevin; Wood, Marissa; Phillip, Nathan D.; Sheng, Yangping; Mao, Chengyu; Kalnaus, Sergiy; Daniel, Claus; Wood, David L.

    2017-06-01

    Reducing cost and increasing energy density are two barriers for widespread application of lithium-ion batteries in electric vehicles. Although the cost of electric vehicle batteries has been reduced by 70% from 2008 to 2015, the current battery pack cost (268/kWh in 2015) is still >2 times what the USABC targets (125/kWh). Even though many advancements in cell chemistry have been realized since the lithium-ion battery was first commercialized in 1991, few major breakthroughs have occurred in the past decade. Therefore, future cost reduction will rely on cell manufacturing and broader market acceptance. This article discusses three major aspects for cost reduction: (1) quality control to minimize scrap rate in cell manufacturing; (2) novel electrode processing and engineering to reduce processing cost and increase energy density and throughputs; and (3) material development and optimization for lithium-ion batteries with high-energy density. Insights on increasing energy and power densities of lithium-ion batteries are also addressed.

  7. Toward Low-Cost, High-Energy Density, and High-Power Density Lithium-Ion Batteries

    Science.gov (United States)

    Li, Jianlin; Du, Zhijia; Ruther, Rose E.; AN, Seong Jin; David, Lamuel Abraham; Hays, Kevin; Wood, Marissa; Phillip, Nathan D.; Sheng, Yangping; Mao, Chengyu; Kalnaus, Sergiy; Daniel, Claus; Wood, David L.

    2017-09-01

    Reducing cost and increasing energy density are two barriers for widespread application of lithium-ion batteries in electric vehicles. Although the cost of electric vehicle batteries has been reduced by 70% from 2008 to 2015, the current battery pack cost (268/kWh in 2015) is still >2 times what the USABC targets (125/kWh). Even though many advancements in cell chemistry have been realized since the lithium-ion battery was first commercialized in 1991, few major breakthroughs have occurred in the past decade. Therefore, future cost reduction will rely on cell manufacturing and broader market acceptance. This article discusses three major aspects for cost reduction: (1) quality control to minimize scrap rate in cell manufacturing; (2) novel electrode processing and engineering to reduce processing cost and increase energy density and throughputs; and (3) material development and optimization for lithium-ion batteries with high-energy density. Insights on increasing energy and power densities of lithium-ion batteries are also addressed.

  8. High-strength high-conductivity Cu-Nb microcomposite sheet fabricated via multiple roll bonding

    Science.gov (United States)

    Jha, S. C.; Delagi, R. G.; Forster, J. A.; Krotz, P. D.

    1993-01-01

    Copper-niobium microcomposites are a new class of high-strength high-conductivity materials that have attractive properties for room- and elevated-temperature applications. Since Nb has little solid solubility in Cu, addition of Nb to Cu does not affect its conductivity. Copper-niobium microcomposites are melted and cast so that the microstructure of cast Cu-Nb ingots consists of 1-to 10 μm Nb dendrites uniformly distributed within the copper matrix. Extensive wire drawing with a true processing strain ( η > 12) of Cu-Nb alloy leads to refinement and elongation of Nb dendrites into 1-to 10 nm-thick filaments. The presence of such fine Nb filaments causes a significant increase in the strength of Cu-Nb wires. The tensile strength of heavily drawn Cu-Nb wires was determined to be significantly higher than the values predicted by the rule of mixtures. This article reports the fabrication of high-strength Cu-Nb micro-composite sheet by multiple roll bonding. It is difficult and impractical to attain high processing strains ( η > 3) by simple cold rolling. In most practical cold-rolling operation, the thickness reduction does not exceed 90 pct ( η ≅ 2). Therefore, innovative processing is required to generate high strength in Cu-Nb microcomposite sheet. Multiple roll bonding of Cu-Nb has been utilized to store high processing strain ( η > 10) in the material and refine the Nb particle size within the copper matrix. This article describes the microstructure, mechanical properties, and thermal stability of roll-bonded Cu-Nb microcomposite sheet.

  9. Multifractal analysis of high resolution solar wind proton density measurements

    Science.gov (United States)

    Sorriso-Valvo, Luca; Carbone, Francesco; Leonardis, Ersilia; Chen, Christopher H. K.; Šafránková, Jana; Němeček, Zdenek

    2017-03-01

    The solar wind is a highly turbulent medium, with a high level of field fluctuations throughout a broad range of scales. These include an inertial range where a turbulent cascade is assumed to be active. The solar wind cascade shows intermittency, which however may depend on the wind conditions. Recent observations have shown that ion-scale magnetic turbulence is almost self-similar, rather than intermittent. A similar result was observed for the high resolution measurements of proton density provided by the spacecraft Spektr-R. Intermittency may be interpreted as the result of the multifractal properties of the turbulent cascade. In this perspective, this paper is devoted to the description of the multifractal properties of the high resolution density measurements. In particular, we have used the standard coarse-graining technique to evaluate the generalized dimensions Dq , and from these the multifractal spectrum f (α) , in two ranges of scale. A fit with the p-model for intermittency provided a quantitative measure of multifractality. Such indicator was then compared with alternative measures: the width of the multifractal spectrum, the peak of the kurtosis, and its scaling exponent. The results indicate that the small-scale fluctuations are multifractal, and suggest that different measures of intermittency are required to fully understand the small scale cascade.

  10. Ultra-Stretchable Interconnects for High-Density Stretchable Electronics

    Directory of Open Access Journals (Sweden)

    Salman Shafqat

    2017-09-01

    Full Text Available The exciting field of stretchable electronics (SE promises numerous novel applications, particularly in-body and medical diagnostics devices. However, future advanced SE miniature devices will require high-density, extremely stretchable interconnects with micron-scale footprints, which calls for proven standardized (complementary metal-oxide semiconductor (CMOS-type process recipes using bulk integrated circuit (IC microfabrication tools and fine-pitch photolithography patterning. Here, we address this combined challenge of microfabrication with extreme stretchability for high-density SE devices by introducing CMOS-enabled, free-standing, miniaturized interconnect structures that fully exploit their 3D kinematic freedom through an interplay of buckling, torsion, and bending to maximize stretchability. Integration with standard CMOS-type batch processing is assured by utilizing the Flex-to-Rigid (F2R post-processing technology to make the back-end-of-line interconnect structures free-standing, thus enabling the routine microfabrication of highly-stretchable interconnects. The performance and reproducibility of these free-standing structures is promising: an elastic stretch beyond 2000% and ultimate (plastic stretch beyond 3000%, with <0.3% resistance change, and >10 million cycles at 1000% stretch with <1% resistance change. This generic technology provides a new route to exciting highly-stretchable miniature devices.

  11. Pistachio intake increases high density lipoprotein levels and inhibits low-density lipoprotein oxidation in rats.

    Science.gov (United States)

    Aksoy, Nur; Aksoy, Mehmet; Bagci, Cahit; Gergerlioglu, H Serdar; Celik, Hakim; Herken, Emine; Yaman, Abdullah; Tarakcioglu, Mehmet; Soydinc, Serdar; Sari, Ibrahim; Davutoglu, Vedat

    2007-05-01

    There is increasing evidence that nuts have protective effects against coronary artery disease by improving lipid profile and inhibiting lipid oxidation. However, data about pistachio nuts are limited, and to our knowledge, there is no study investigating the effects of pistachio intake on lipid oxidation and serum antioxidant levels. This study, therefore, sought to determine the effects of pistachio intake on serum lipids and determine whether consumption of pistachio would alter serum antioxidant levels. Rats were randomly divided into three groups (n=12 for each): control group fed basic diet for 10 weeks and treated groups fed basic diet plus pistachio which constituted 20% and 40% of daily caloric intake, respectively. Consumption of pistachio as 20% of daily caloric intake increased high-density lipoprotein (HDL) levels and decreased total cholesterol (TC)/HDL ratio, compared with those not taking pistachio. However, TC, low-density lipoprotein (LDL) cholesterol and triglyceride levels were unaffected by pistachio consumption. Consumption of pistachio as 20% of daily caloric intake increased serum paraoxonase activity by 35% and arylesterase activity by 60%, which are known to inhibit LDL cholesterol oxidation, compared with the control group. However, increased antioxidant activity was blunted when pistachio intake was increased to 40% of daily caloric intake. In conclusion, the present results show that consumption of pistachio as 20% of daily caloric intake leads to significant improvement in HDL and TC/HDL ratio and inhibits LDL cholesterol oxidation. These results suggest that pistachio may be beneficial for both prevention and treatment of coronary artery disease.

  12. Fabrication of highly uniform conductive polypyrrole nanowires with DNA template.

    Science.gov (United States)

    Moon, Hock Key; Kim, Hyung Jin; Kim, Nam-Hoon; Roh, Yonghan

    2010-05-01

    Deoxyribonucleic acid (DNA) is considered as one of the alternative materials for electronic device applications; however, DNA has critical limitation to electronic device applications due to its low electrical conductivity and unreliability. Therefore, it is required for electronic devices to prepare the well defined conductive polymer nanowires with DNA as a template. Polypyrrole (PPy) is an attractive polymer due to its high conductivity and environmental stability in bulk; although it is well known that ammonium persulfate (APS) used for the polymerization of pyrrole causes the deformation of DNA molecules. We minimized the damage of immobilized DNA strands on (3-aminopropyl) triethoxysilane (APTES) modified silicon wafer during APS polymerization. Atomic force microscopy (AFM) images from different APS treatment times and from using the vortex process obviously showed the effect on the synthesis of individual and continuous polypyrrole nanowires (PPy NWs). The PPy NWs at various pyrrole concentrations had similar height; however, the higher concentration gave more residues. Fourier transform-infrared spectroscopy (FT-IR) spectroscopy provided the strong evidence that PPy NWs were successfully synthesized on the DNA strands.

  13. Functionalization of Polypyrrole Nanopipes with Redox-Active Polyoxometalates for High Energy Density Supercapacitors.

    Science.gov (United States)

    Dubal, Deepak P; Ballesteros, Belén; Mohite, Ashwini A; Gómez-Romero, Pedro

    2017-02-22

    Hybrid materials are very attractive for the fabrication of high-performance supercapacitors. Here, we have explored organic-inorganic hybrid materials based on open-end porous 1 D polypyrrole nanopipes (PPy-NPipes) and heteropolyoxometalates (phosphotungstate ([PW12 O40 ](3-) , PW12 ) or phosphomolybdate ([PMo12 O40 ](3-) , PMo12 )) that display excellent areal capacitances. Two different hybrid materials (PMo12 @PPy and PW12 @PPy) were effectively synthesized and used for symmetric supercapacitors. The anchoring of the inorganic nanoclusters onto the conducting polymer nanopipes led to electrodes that stood up to our best expectations exhibiting outstanding areal capacitances that are almost 1.5 to 2 fold higher than that of pristine PPy-NPipes. In addition, symmetric cells based on PMo12 @PPy and PW12 @PPy hybrid electrodes were fabricated and showed significant improvement in cell performance with very high volumetric capacitances in the range of 6.3-6.8 F cm(-3) (considering the volume of whole device). Indeed, they provide extended potential windows in acidic electrolytes (up to 1.5 V) which led to ultrahigh energy densities of 1.5 and 2.2 mWh cm(-3) for PMo12 @PPy and PW12 @PPy cells, respectively. Thus, these unique organic-inorganic hybrid symmetric cells displayed extraordinary electrochemical performances far exceeding those of more complex asymmetric systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Photolithographic Synthesis of High-Density DNA and RNA Arrays on Flexible, Transparent, and Easily Subdivided Plastic Substrates.

    Science.gov (United States)

    Holden, Matthew T; Carter, Matthew C D; Wu, Cheng-Hsien; Wolfer, Jamison; Codner, Eric; Sussman, Michael R; Lynn, David M; Smith, Lloyd M

    2015-11-17

    The photolithographic fabrication of high-density DNA and RNA arrays on flexible and transparent plastic substrates is reported. The substrates are thin sheets of poly(ethylene terephthalate) (PET) coated with cross-linked polymer multilayers that present hydroxyl groups suitable for conventional phosphoramidite-based nucleic acid synthesis. We demonstrate that by modifying array synthesis procedures to accommodate the physical and chemical properties of these materials, it is possible to synthesize plastic-backed oligonucleotide arrays with feature sizes as small as 14 μm × 14 μm and feature densities in excess of 125 000/cm(2), similar to specifications attainable using rigid substrates such as glass or glassy carbon. These plastic-backed arrays are tolerant to a wide range of hybridization temperatures, and improved synthetic procedures are described that enable the fabrication of arrays with sequences up to 50 nucleotides in length. These arrays hybridize with S/N ratios comparable to those fabricated on otherwise identical arrays prepared on glass or glassy carbon. This platform supports the enzymatic synthesis of RNA arrays and proof-of-concept experiments are presented showing that the arrays can be readily subdivided into smaller arrays (or "millichips") using common laboratory-scale laser cutting tools. These results expand the utility of oligonucleotide arrays fabricated on plastic substrates and open the door to new applications for these important bioanalytical tools.

  15. Fabrication of Ni-Mn Microprobe Structure with Low Internal Stress and High Hardness by Employing DC Electrodeposition

    Directory of Open Access Journals (Sweden)

    Kuan-Hui Cheng

    2014-01-01

    Full Text Available Due to its widely tunable mechanical property and incompatibility with most solders, Ni-Mn alloy can become a viable candidate in the fabrication of testing probe for microelectronic devices. In this study, the electrodeposition of Ni-Mn alloy in nickel sulphamate electrolyte with the addition of manganese sulphate was investigated under direct current (DC power source. The effects of current density and Mn2+ concentration in the electrolyte on the coating composition, cathodic efficiency, microstructure and mechanical properties were explored. The results showed that the raise of the Mn2+ concentration in the electrolyte alone did not effectively increase the Mn content in the coating but reduce the cathodic efficiency. On the other hand, increasing the current density facilitated the codeposition of the Mn and rendered the crystallite from coarse columnar grain to the refined one. Thus, both hardness and internal stress of the coating increased. The fabrication of testing probes at 1 A/dm2 was shown to satisfy the high hardness, low internal stress, reasonable fatigue life, and nonsticking requirements for this microelectronic application.

  16. High energy density capacitors using nano-structure multilayer technology

    Energy Technology Data Exchange (ETDEWEB)

    Barbee, T.W. Jr.; Johnson, G.W.; O`Brien, D.W.

    1992-08-01

    Today, many pulse power and industrial applications are limited by capacitor performance. While incremental improvements are anticipated from existing capacitor technologies, significant advances are needed in energy density to enable these applications for both the military and for American economic competitiveness. We propose a program to research and develop a novel technology for making high voltage, high energy density capacitors. Nano-structure multilayer technologies developed at LLNL may well provide a breakthrough in capacitor performance. Our controlled sputtering techniques are capable of laying down extraordinarily smooth sub-micron layers of dielectric and conductor materials. With this technology, high voltage capacitors with an order of magnitude improvement in energy density may be achievable. Well-understood dielectrics and new materials will be investigated for use with this technology. Capacitors developed by nano-structure multilayer technology are inherently solid state, exhibiting extraordinary mechanical and thermal properties. The conceptual design of a Notepad capacitor is discussed to illustrate capacitor and capacitor bank design and performance with this technology. We propose a two phase R&D program to address DNA`s capacitor needs for electro-thermal propulsion and similar pulse power programs. Phase 1 will prove the concept and further our understanding of dielectric materials and design tradeoffs with multilayers. Nano-structure multilayer capacitors will be developed and characterized. As our materials research and modeling prove successful, technology insertion in our capacitor designs will improve the possibility for dramatic performance improvements. In Phase 2, we will make Notepad capacitors, construct a capacitor bank and demonstrate its performance in a meaningful pulse power application. We will work with industrial partners to design full scale manufacturing and move this technology to industry for volume production.

  17. Structural and electrical characteristics of high-k/metal gate metal oxide semiconductor capacitors fabricated on flexible, semi-transparent silicon (100) fabric

    KAUST Repository

    Rojas, Jhonathan Prieto

    2013-02-12

    In pursuit of flexible computers with high performance devices, we demonstrate a generic process to fabricate 10 000 metal-oxide-semiconductor capacitors (MOSCAPs) with semiconductor industry\\'s most advanced high-k/metal gate stacks on widely used, inexpensive bulk silicon (100) wafers and then using a combination of iso-/anisotropic etching to release the top portion of the silicon with the already fabricated devices as a mechanically flexible (bending curvature of 133 m−1), optically semi-transparent silicon fabric (1.5 cm × 3 cm × 25 μm). The electrical characteristics show 3.7 nm effective oxide thickness, −0.2 V flat band voltage, and no hysteresis from the fabricated MOSCAPs.

  18. The Pulsed High Density Experiment (PHDX) Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Slough, John P. [Univ. of Washington, Seattle, WA (United States); Andreason, Samuel [Univ. of Washington, Seattle, WA (United States)

    2017-04-27

    The purpose of this paper is to present the conclusions that can be drawn from the Field Reversed Configuration (FRC) formation experiments conducted on the Pulsed High Density experiment (PHD) at the University of Washington. The experiment is ongoing. The experimental goal for this first stage of PHD was to generate a stable, high flux (>10 mWb), high energy (>10 KJ) target FRC. Such results would be adequate as a starting point for several later experiments. This work focuses on experimental implementation and the results of the first four month run. Difficulties were encountered due to the initial on-axis plasma ionization source. Flux trapping with this ionization source acting alone was insufficient to accomplish experimental objectives. Additional ionization methods were utilized to overcome this difficulty. A more ideal plasma source layout is suggested and will be explored during a forthcoming work.

  19. [Residual risk: The roles of triglycerides and high density lipoproteins].

    Science.gov (United States)

    Grammer, Tanja; Kleber, Marcus; Silbernagel, Günther; Scharnagl, Hubert; März, Winfried

    2016-06-01

    In clinical trials, the reduction of LDL-cholesterol (LDL-C) with statins reduces the incidence rate of cardiovascular events by approximately one third. This means, that a sizeable "residual risk" remains. Besides high lipoprotein (a), disorders in the metabolism of triglyceride-rich lipoproteins and high density liproteins have been implicated as effectors of the residual risk. Both lipoprotein parameters correlate inversely with each other. Therefore, the etiological contributions of triglycerides and / or of HDL for developing cardiovascular disease can hardly be estimated from either observational studies or from intervention studies. The largely disappointing results of intervention studies with inhibitors of the cholesteryl ester transfer protein and in particular the available set of genetically-epidemiological studies suggest that in the last decade, the importance of HDL cholesterol has been overvalued, while the importance of triglycerides has been underestimated. High triglycerides not always atherogenic, but only if they are associated with the accumulation relatively cholesterol-enriched, incompletely catabolized remnants of chylomicrons and very low density lipoproteins (familial type III hyperlipidemia, metabolic syndrome, diabetes mellitus). The normalization of the concentration of triglycerides and remnants by inhibiting the expression of apolipoprotein C3 is hence a new, promising therapeutic target.

  20. Metal hydrides based high energy density thermal battery

    Energy Technology Data Exchange (ETDEWEB)

    Fang, Zhigang Zak, E-mail: zak.fang@utah.edu [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Zhou, Chengshang; Fan, Peng [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Udell, Kent S. [Department of Metallurgical Engineering, The University of Utah, 50 S. Central Campus Dr., Room 2110, Salt Lake City, UT 84112-0114 (United States); Bowman, Robert C. [Department of Metallurgical Engineering, The University of Utah, 135 South 1460 East, Room 412, Salt Lake City, UT 84112-0114 (United States); Vajo, John J.; Purewal, Justin J. [HRL Laboratories, LLC, 3011 Malibu Canyon Road, Malibu, CA 90265 (United States); Kekelia, Bidzina [Department of Metallurgical Engineering, The University of Utah, 50 S. Central Campus Dr., Room 2110, Salt Lake City, UT 84112-0114 (United States)

    2015-10-05

    Highlights: • The principle of the thermal battery using advanced metal hydrides was demonstrated. • The thermal battery used MgH{sub 2} and TiMnV as a working pair. • High energy density can be achieved by the use of MgH{sub 2} to store thermal energy. - Abstract: A concept of thermal battery based on advanced metal hydrides was studied for heating and cooling of cabins in electric vehicles. The system utilized a pair of thermodynamically matched metal hydrides as energy storage media. The pair of hydrides that was identified and developed was: (1) catalyzed MgH{sub 2} as the high temperature hydride material, due to its high energy density and enhanced kinetics; and (2) TiV{sub 0.62}Mn{sub 1.5} alloy as the matching low temperature hydride. Further, a proof-of-concept prototype was built and tested, demonstrating the potential of the system as HVAC for transportation vehicles.

  1. A New Hard Switching Bidirectional Converter With High Power Density

    Directory of Open Access Journals (Sweden)

    Bahador Fani

    2010-01-01

    Full Text Available In this paper, a new isolated dc-dc bidirectional converter is proposed. This converter consists of two transformers (flyback and forward and only one switch in primary side and one switch in secondary side of transformers. In this converter energy transfers to the output in both on and off switch states so power density of this converter is high This converter controlled by PWM signal. Also this converter operates over a wide input voltage range. Theoretical analysis is presented and computer simulation and experimental results verify the converter analysis.

  2. On high-order perturbative calculations at finite density

    CERN Document Server

    Ghisoiu, Ioan

    2017-01-01

    We discuss the prospects of performing high-order perturbative calculations in systems characterized by a vanishing temperature but finite density. In particular, we show that the determination of generic Feynman integrals containing fermionic chemical potentials can be reduced to the evaluation of three-dimensional phase space integrals over vacuum on-shell amplitudes. Applications of these rules will be discussed in the context of the thermodynamics of cold and dense QCD, where it is argued that they facilitate an extension of the Equation of State of cold quark matter to higher perturbative orders.

  3. On high-order perturbative calculations at finite density

    Science.gov (United States)

    Ghişoiu, Ioan; Gorda, Tyler; Kurkela, Aleksi; Romatschke, Paul; Säppi, Matias; Vuorinen, Aleksi

    2017-02-01

    We discuss the prospects of performing high-order perturbative calculations in systems characterized by a vanishing temperature but finite density. In particular, we show that the determination of generic Feynman integrals containing fermionic chemical potentials can be reduced to the evaluation of three-dimensional phase space integrals over vacuum on-shell amplitudes - a result reminiscent of a previously proposed "naive real-time formalism" for vacuum diagrams. Applications of these rules are discussed in the context of the thermodynamics of cold and dense QCD, where it is argued that they facilitate an extension of the Equation of State of cold quark matter to higher perturbative orders.

  4. Ultra High Energy Density Cathodes with Carbon Nanotubes

    Science.gov (United States)

    2013-12-10

    34Enhanced Capacity and Rate Capability of Carbon Nanotube Based Anodes with Titanium Contacts for Lithium Ion Batteries," ACS Nano, vol. 4, pp. 6121- 6131...2010/10/26 2010. [2] S. L. Chou, et al., "Silicon/Single-Walled Carbon Nanotube Composite Paper as a Flexible Anode Material for Lithium Ion...AFRL-RV-PS- AFRL-RV-PS- TR-2013-0170 TR-2013-0170 ULTRA HIGH ENERGY DENSITY CATHODES WITH CARBON NANOTUBES Brian J. Landi, et al. Rochester

  5. High density QCD and entropy production at heavy ion colliders

    CERN Document Server

    Kinder-Geiger, Klaus

    1994-01-01

    The role of entropy production in the context of probing QCD properties at high densities and finite temperatures in ultra-relativistic collisions of heavy nuclei is inspected. It is argued that the entropy generated in these reactions provides a powerful tool to investigate the space-time evolution and the question whether and how a deconfined plasma of quarks and gluons is formed. I will address the questions how entropy is produced, and how it is measurable. The uncertainties in predicting the different contributions to the total entropy and particle multiplicities during the course of heavy ion collisions are also discussed.

  6. Method for providing a low density high strength polyurethane foam

    Science.gov (United States)

    Whinnery, Jr., Leroy L.; Goods, Steven H.; Skala, Dawn M.; Henderson, Craig C.; Keifer, Patrick N.

    2013-06-18

    Disclosed is a method for making a polyurethane closed-cell foam material exhibiting a bulk density below 4 lbs/ft.sup.3 and high strength. The present embodiment uses the reaction product of a modified MDI and a sucrose/glycerine based polyether polyol resin wherein a small measured quantity of the polyol resin is "pre-reacted" with a larger quantity of the isocyanate in a defined ratio such that when the necessary remaining quantity of the polyol resin is added to the "pre-reacted" resin together with a tertiary amine catalyst and water as a blowing agent, the polymerization proceeds slowly enough to provide a stable foam body.

  7. The physics of ultra-high-density magnetic recording

    CERN Document Server

    Ek, Johannes; Weller, Dieter

    2001-01-01

    In this book, 17 experts in magnetic recording focus on the underlying physical mechanisms that play crucial roles in medium and transducer development for high areal density disk drives. In 11 chapters, an examination is made of the fundamental physical concepts and their impact on recording mechanisms, with special emphasis on thin-film longitudinal, perpendicular, patterned and nanoparticle media. Theoretical and experimental investigations are presented which serve to enhance our basic understanding of thin-film dynamics, medium dynamics and thermal effects. Fundamental aspects of magnetotransport are discussed and an overview is given of recording head designs.

  8. Antarctic marine gravity field from high-density satellite altimetry

    Science.gov (United States)

    Sandwell, David T.

    1992-01-01

    High-density (about 2-km profile spacing) Geosat/GM altimetry profiles were obtained for Antarctic waters (6-deg S to 72 deg S) and converted to vertical gravity gradient, using Laplace's equation to directly calculate gravity gradient from vertical deflection grids and Fourier analysis to construct gravity anomalies from two vertical deflection grids. The resultant gravity grids have resolution and accuracy comparable to shipboard gravity profiles. The obtained gravity maps display many interesting and previously uncharted features, such as a propagating rift wake and a large 'leaky transform' along the Pacific-Antarctic Rise.

  9. A Cherenkov Radiation Detector with High Density Aerogels

    CERN Document Server

    Cremaldi, Lucien; Sonnek, Peter; Summers, Donald J; Reidy, Jim

    2009-01-01

    We have designed a threshold Cherenkov detector at the Rutherford-Appleton Laboratory to identify muons with momenta between 230 and 350 MeV/c. We investigated the properties of three aerogels for the design. The nominal indexes of refraction were n = 1.03, 1.07, 1.12, respectively. Two of the samples are of high density aerogel not commonly used for Cherenkov light detection. We present results of an examination of some optical properties of the aerogel samples and present basic test beam results.

  10. Biomimetic High Density Lipoprotein Nanoparticles For Nucleic Acid Delivery

    Science.gov (United States)

    McMahon, Kaylin M.; Mutharasan, R. Kannan; Tripathy, Sushant; Veliceasa, Dorina; Bobeica, Mariana; Shumaker, Dale K.; Luthi, Andrea J.; Helfand, Brian T.; Ardehali, Hossein; Mirkin, Chad A.; Volpert, Olga; Thaxton, C. Shad

    2014-01-01

    We report a gold nanoparticle-templated high density lipoprotein (HDL AuNP) platform for gene therapy which combines lipid-based nucleic acid transfection strategies with HDL biomimicry. For proof-of-concept, HDL AuNPs are shown to adsorb antisense cholesterylated DNA. The conjugates are internalized by human cells, can be tracked within cells using transmission electron microscopy (TEM), and regulate target gene expression. Overall, the ability to directly image the AuNP core within cells, the chemical tailorability of the HDL AuNP platform, and the potential for cell-specific targeting afforded by HDL biomimicry make this platform appealing for nucleic acid delivery. PMID:21319839

  11. High-density EMG E-textile systems for the control of active prostheses.

    Science.gov (United States)

    Farina, Dario; Lorrain, Thomas; Negro, Francesco; Jiang, Ning

    2010-01-01

    Myoelectric control of active prostheses requires electrode systems that are easy to apply for daily repositioning of the electrodes by the user. In this study we propose the use of Smart Fabric and Interactive Textile (SFIT) systems as an alternative solution for recording high-density EMG signals for myoelectric control. A sleeve covering the upper and lower arm, which contains 100 electrodes arranged in four grids of 5 × 5 electrodes, was used to record EMG signals in 3 subjects during the execution of 9 tasks of the wrist and hand. The signals were analyzed by extracting wavelet coefficients which were classified with linear discriminant analysis. The average classification accuracy for the nine tasks was 89.1 ± 1.9 %. These results show that SFIT systems can be used as an effective way for muscle-machine interfacing.

  12. High Density Hydrogen Storage System Demonstration Using NaAlH4 Based Complex Compound Hydrides

    Energy Technology Data Exchange (ETDEWEB)

    Daniel A. Mosher; Xia Tang; Ronald J. Brown; Sarah Arsenault; Salvatore Saitta; Bruce L. Laube; Robert H. Dold; Donald L. Anton

    2007-07-27

    This final report describes the motivations, activities and results of the hydrogen storage independent project "High Density Hydrogen Storage System Demonstration Using NaAlH4 Based Complex Compound Hydrides" performed by the United Technologies Research Center under the Department of Energy Hydrogen Program, contract # DE-FC36-02AL67610. The objectives of the project were to identify and address the key systems technologies associated with applying complex hydride materials, particularly ones which differ from those for conventional metal hydride based storage. This involved the design, fabrication and testing of two prototype systems based on the hydrogen storage material NaAlH4. Safety testing, catalysis studies, heat exchanger optimization, reaction kinetics modeling, thermochemical finite element analysis, powder densification development and material neutralization were elements included in the effort.

  13. Development of high power density cathode materials for Li-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Ketterer, B.; Vasilchina, H.; Seemann, K.; Ulrich, S.; Besser, H.; Pfleging, W.; Kaiser, T.; Adelhelm, C. [Forschungszentrum Karlsruhe (Germany). IMF I

    2008-10-15

    Cathode material for Li-ion batteries can be synthesised by r.f. magnetron sputtering of LiCoO{sub 2} targets in a pure Ar plasma. This technique is suitable for large-scale implementation in foil coating set-ups. By choosing the process parameters and by employing post heat treatment nanocrystalline, stoichiometrical LiCoO{sub 2} films can be fabricated which exhibit the desired high temperature phase. The determination of the elementary composition is possible by optical emission spectroscopy including plasma stimulation and carrier gas temperature extraction. The proof of crystal structure is carried out by X-ray diffraction and Raman spectroscopy. Heat treatment can be conventionally realised in a furnace or by laser impact. With regard to increasing the power density, the surface of the cathode material can be enhanced six-fold by laser-assisted surface patterning. (orig.)

  14. Bearing Capacity of High Density Polyethylene (HDPE Reinforced Sand Using Plate Load Test

    Directory of Open Access Journals (Sweden)

    Er. Aly K

    2015-06-01

    Full Text Available The work presented here is a study to examine the improvement in bearing capacity of coastal sand of Trivandrum, Kerala, India using high density polyethylene (HDPE /woven fabric as reinforcement in discrete layers. The bearing capacity was evaluated using plate load test. The effect of reinforcement configurations like sheet reinforcement (sanded with adhesive, with adhesive and sheet alone and strip reinforcement (single and grid pattern are investigated. The test parameters chosen for the present study are, depth of topmost layer of reinforcement layer below footing, compacted density and number of layers of reinforcement etc. From the tests, it has been observed that sheet reinforcement is more effective than sheet sanded with adhesive and strip reinforcements. It is found that the synthetic adhesive gives no binding action at the interface of the reinforcement and soil. But it is to be noted that the sheet with adhesive dried has a marked influence on the bearing capacity especially at lower densities. The strip reinforcements in single pattern is considered to be a favorable choice for minimum reinforcement. The strip reinforcement in single or grid pattern gives sufficient improvement in strength.

  15. Biominetic High Density Lipoproteins for the Delivery of Therapeutic Oligonucleotides

    Science.gov (United States)

    Tripathy, Sushant

    Advances in nanotechnology have brought about novel inorganic and hybrid nanoparticles with unique physico-chemical properties that make them suitable for a broad range of applications---from nano-circuitry to drug delivery. A significant part of those advancements have led to ground-breaking discoveries that have changed the approaches to formulation of therapeutics against diseases, such as cancer. Now-a-days the focus does not lie solely on finding a candidate small-molecule therapeutic with minimal adverse effects, but researchers are looking up to nanoparticles to improve biodistribution and biocompatibility profile of clinically proven therapeutics. The plethora of conjugation chemistries offered by currently extant inorganic nanoparticles have, in recent years, led to great leaps in the field of biomimicry---a modality that promises high biocompatibility. Further, in the pursuit of highly specific therapeutic molecules, researchers have turned to silencing oligonucleotides and some have already brought together the strengths of nanoparticles and silencing oligonucleotides in search of an efficacious therapy for cancer with minimal adverse effects. This dissertation work focuses on such a biomimetic platform---a gold nanoparticle based high density lipoprotein biomimetic (HDL NP), for the delivery of therapeutic oligonucleotides. The first chapter of this body of work introduces the molecular target of the silencing oligonucleotides---VEGFR2, and its role in the progression of solid tumor cancers. The background information also covers important aspects of natural high density lipoproteins (HDL), especially their innate capacity to bind and deliver exogenous and endogenous silencing oligonucleotides to tissues that express their high affinity receptor SRB1. We subsequently describe the synthesis of the biomimetic HDL NP and its oligonucleotide conjugates, and establish their biocompatibility. Further on, experimental data demonstrate the efficacy of silencing

  16. Large-scale fabrication of linear low density polyethylene/layered double hydroxides composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties

    Science.gov (United States)

    Xie, Jiazhuo; Zhang, Kun; Zhao, Qinghua; Wang, Qingguo; Xu, Jing

    2016-11-01

    Novel LDH intercalated with organic aliphatic long-chain anion was large-scale synthesized innovatively by high-energy ball milling in one pot. The linear low density polyethylene (LLDPE)/layered double hydroxides (LDH) composite films with enhanced heat retention, thermal, mechanical, optical and water vapor barrier properties were fabricated by melt blending and blowing process. FT IR, XRD, SEM results show that LDH particles were dispersed uniformly in the LLDPE composite films. Particularly, LLDPE composite film with 1% LDH exhibited the optimal performance among all the composite films with a 60.36% enhancement in the water vapor barrier property and a 45.73 °C increase in the temperature of maximum mass loss rate compared with pure LLDPE film. Furthermore, the improved infrared absorbance (1180-914 cm-1) of LLDPE/LDH films revealed the significant enhancement of heat retention. Therefore, this study prompts the application of LLDPE/LDH films as agricultural films with superior heat retention.

  17. Simulating deposition of high density tailings using smoothed particle hydrodynamics

    Science.gov (United States)

    Babaoglu, Yagmur; Simms, Paul H.

    2017-08-01

    Tailings are a slurry of silt-sized residual material derived from the milling of rock. High density (HD) tailings are tailings that have been sufficiently dewatered to a point where they exhibit a yield stress upon deposition. They form gently sloped stacks on the surface when deposited; this eliminates or minimizes the need for dams or embankments for containment. Understanding the flow behaviour of high density tailings is essential for estimating the final stack geometry and overall slope angle. This paper focuses on modelling the flow behaviour of HD tailings using smoothed particle hydrodynamics (SPH) method incorporating a `bi-viscosity' model to simulate the non-Newtonian behaviour. The model is validated by comparing the numerical results with bench scale experiments simulating single or multi-layer deposits in two-dimensions. The results indicate that the model agreed fairly well with the experimental work, excepting some repulsion of particles away from the bottom boundary closer to the toe of the deposits. Novel aspects of the work, compared to other simulation of Bingham fluids by SPH, are the simulation of multilayer deposits and the use of a stopping criteria to characterize the rest state.

  18. Multiple parton interactions in high-density QCD matter

    CERN Document Server

    Srivastava, D K; Srivastava, Dinesh K.; Geiger, Klaus

    1999-01-01

    Multiple interactions of quarks and gluons in high-energy heavy-ion collisions may give rise to interesting phemomena of color charges propagating in high-density QCD matter. We study the dynamics of multi-parton systems produced in nucleus-nucleus collisions at energies corresponding the the CERN SPS and the future BNL RHIC experiments. Due to the complexity of the multi-particle dynamics we choose to employ the parton cascade model in order to simulate the development of multiple parton scatterings and associated stimulated emision processes. Our results indicate a non-linear increase with nuclear mass A of, e.g., parton multiplicity, energy density, strangeness, and contrast a linear A-scaling as in Glauber-type approaches. If multiple interactions are suppressed and only single parton scatterings (no re-interactions) are considered, we recover such a linear behavior. It remains to be studied whether these results on the parton level can be experimentally seen in final-state observables, such as the charge...

  19. Development Status of High-Thrust Density Electrostatic Engines

    Science.gov (United States)

    Patterson, Michael J.; Haag, Thomas W.; Foster, John E.; Young, Jason A.; Crofton, Mark W.

    2017-01-01

    Ion thruster technology offers the highest performance and efficiency of any mature electric propulsion thruster. It has by far the highest demonstrated total impulse of any technology option, demonstrated at input power levels appropriate for primary propulsion. It has also been successfully implemented for primary propulsion in both geocentric and heliocentric environments, with excellent ground/in-space correlation of both its performance and life. Based on these attributes there is compelling reasoning to continue the development of this technology: it is a leading candidate for high power applications; and it provides risk reduction for as-yet unproven alternatives. As such it is important that the operational limitations of ion thruster technology be critically examined and in particular for its application to primary propulsion its capabilities relative to thrust the density and thrust-to-power ratio be understood. This publication briefly addresses some of the considerations relative to achieving high thrust density and maximizing thrust-to-power ratio with ion thruster technology, and discusses the status of development work in this area being executed under a collaborative effort among NASA Glenn Research Center, the Aerospace Corporation, and the University of Michigan.

  20. Strongly Interacting Matter at Very High Energy Density

    Energy Technology Data Exchange (ETDEWEB)

    McLerran, L.

    2011-06-05

    The authors discuss the study of matter at very high energy density. In particular: what are the scientific questions; what are the opportunities to makes significant progress in the study of such matter and what facilities are now or might be available in the future to answer the scientific questions? The theoretical and experimental study of new forms of high energy density matter is still very much a 'wild west' field. There is much freedom for developing new concepts which can have order one effects on the way we think about such matter. It is also a largely 'lawless' field, in that concepts and methods are being developed as new information is generated. There is also great possibility for new experimental discovery. Most of the exciting results from RHIC experiments were unanticipated. The methods used for studying various effects like flow, jet quenching, the ridge, two particle correlations etc. were developed as experiments evolved. I believe this will continue to be the case at LHC and as we use existing and proposed accelerators to turn theoretical conjecture into tangible reality. At some point this will no doubt evolve into a precision science, and that will make the field more respectable, but for my taste, the 'wild west' times are the most fun.

  1. 3D High Density mmWave Interconnects Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Nuvotronics has developed and optimized the PolyStrataTM process for the fabrication of intricate microwave and millimeter-wave devices. These devices have primarily...

  2. Fabrication of High-Frequency pMUT Arrays on Silicon Substrates

    DEFF Research Database (Denmark)

    Pedersen, Thomas; Zawada, Tomasz; Hansen, Karsten

    2010-01-01

    A novel technique based on silicon micromachining for fabrication of linear arrays of high-frequency piezoelectric micromachined ultrasound transducers (pMUT) is presented. Piezoelectric elements are formed by deposition of lead zirconia titanate into etched features of a silicon substrate...

  3. Design, fabrication and characterization of a highly symmetrical capacitive triaxial accelerometer

    NARCIS (Netherlands)

    Lotters, Joost Conrad; Bomer, Johan G.; Verloop, A.J.; Droog, Adriaan; Olthuis, Wouter; Veltink, Petrus H.; Bergveld, Piet

    1998-01-01

    A highly symmetrical cubic capacitive triaxial accelerometer for biomedical applications has been designed, fabricated and characterized. The outer dimensions of the sensors are 5 mm × 5 mm × 5 mm. The devices are mounted on a standard IC package for easy testing. Features of the triaxial

  4. Investigation of non-halogenated solvent mixtures for high throughput fabrication of polymerfullerene solar cells

    NARCIS (Netherlands)

    Schmidt-Hansberg, B.; Sanyal, M.; Grossiord, N.; Galagan, Y.O.; Baunach, M.; Klein, M.F.G.; Colsmann, A.; Scharfer, P.; Lemmer, U.; Dosch, H.; Michels, J.J; Barrena, E.; Schabel, W.

    2012-01-01

    The rapidly increasing power conversion efficiencies of organic solar cells are an important prerequisite towards low cost photovoltaic fabricated in high throughput. In this work we suggest indane as a non-halogenated replacement for the commonly used halogenated solvent o-dichlorobenzene. Indane w

  5. Materials aspects of integrated high-Tc dc-SQUID magnetometer fabrication

    NARCIS (Netherlands)

    Hilgenkamp, J.W.M.; IJsselsteijn, R.P.J.; Rijnders, A.J.H.M.; Tavares, P.A.C.; Flokstra, J.; Rogalla, H.

    1993-01-01

    An integrated high Tc dc-SQUID magnetometer is being developed. It has in total 10 layers of five different materials. Various materials aspects of the fabrication process will be discussed, especially the smoothness of the films and the techniques to obtain smooth edges. Cross-overs and superconduc

  6. Investigation of non-halogenated solvent mixtures for high throughput fabrication of polymerfullerene solar cells

    NARCIS (Netherlands)

    Schmidt-Hansberg, B.; Sanyal, M.; Grossiord, N.; Galagan, Y.O.; Baunach, M.; Klein, M.F.G.; Colsmann, A.; Scharfer, P.; Lemmer, U.; Dosch, H.; Michels, J.J; Barrena, E.; Schabel, W.

    2012-01-01

    The rapidly increasing power conversion efficiencies of organic solar cells are an important prerequisite towards low cost photovoltaic fabricated in high throughput. In this work we suggest indane as a non-halogenated replacement for the commonly used halogenated solvent o-dichlorobenzene. Indane w

  7. High Energy Density Science at the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Lee, R W

    2007-10-19

    High energy density science (HEDS), as a discipline that has developed in the United States from National Nuclear Security Agency (NNSA)-sponsored laboratory research programs, is, and will remain, a major component of the NNSA science and technology strategy. Its scientific borders are not restricted to NNSA. 'Frontiers in High Energy Density Physics: The X-Games of Contemporary Science' identified numerous exciting scientific opportunities in this field, while pointing to the need for a overarching interagency plan for its evolution. Meanwhile, construction of the first x-ray free-electron laser, the Office-of-Science-funded Linear Coherent Light Source-LCLS: the world's first free electron x-ray laser, with 100-fsec time resolution, tunable x-ray energies, a high rep rate, and a 10 order-of-magnitude increase in brightness over any other x-ray source--led to the realization that the scientific needs of NNSA and the broader scientific community could be well served by an LCLS HEDS endstation employing both short-pulse and high-energy optical lasers. Development of this concept has been well received in the community. NNSA requested a workshop on the applicability of LCLS to its needs. 'High Energy Density Science at the LCLS: NNSA Defense Programs Mission Need' was held in December 2006. The workshop provided strong support for the relevance of the endstation to NNSA strategic requirements. The range of science that was addressed covered a wide swath of the vast HEDS phase space. The unique possibilities provided by the LCLS in areas of intense interest to NNSA Defense Programs were discussed. The areas of focus included warm dense matter and equations of state, hot dense matter, and behavior of high-pressure materials under conditions of high strain-rate and extreme dynamic loading. Development of new and advanced diagnostic techniques was also addressed. This report lays out the relevant science, as brief summaries (Ch. II), expanded

  8. Diagnostics for ion beam driven high energy density physics experiments.

    Science.gov (United States)

    Bieniosek, F M; Henestroza, E; Lidia, S; Ni, P A

    2010-10-01

    Intense beams of heavy ions are capable of heating volumetric samples of matter to high energy density. Experiments are performed on the resulting warm dense matter (WDM) at the NDCX-I ion beam accelerator. The 0.3 MeV, 30 mA K(+) beam from NDCX-I heats foil targets by combined longitudinal and transverse neutralized drift compression of the ion beam. Both the compressed and uncompressed parts of the NDCX-I beam heat targets. The exotic state of matter (WDM) in these experiments requires specialized diagnostic techniques. We have developed a target chamber and fielded target diagnostics including a fast multichannel optical pyrometer, optical streak camera, laser Doppler-shift interferometer (Velocity Interferometer System for Any Reflector), beam transmission diagnostics, and high-speed gated cameras. We also present plans and opportunities for diagnostic development and a new target chamber for NDCX-II.

  9. Diagnostics for ion beam driven high energy density physics experimentsa)

    Science.gov (United States)

    Bieniosek, F. M.; Henestroza, E.; Lidia, S.; Ni, P. A.

    2010-10-01

    Intense beams of heavy ions are capable of heating volumetric samples of matter to high energy density. Experiments are performed on the resulting warm dense matter (WDM) at the NDCX-I ion beam accelerator. The 0.3 MeV, 30 mA K+ beam from NDCX-I heats foil targets by combined longitudinal and transverse neutralized drift compression of the ion beam. Both the compressed and uncompressed parts of the NDCX-I beam heat targets. The exotic state of matter (WDM) in these experiments requires specialized diagnostic techniques. We have developed a target chamber and fielded target diagnostics including a fast multichannel optical pyrometer, optical streak camera, laser Doppler-shift interferometer (Velocity Interferometer System for Any Reflector), beam transmission diagnostics, and high-speed gated cameras. We also present plans and opportunities for diagnostic development and a new target chamber for NDCX-II.

  10. The Chandra High Energy Transmission Grating: Design, Fabrication, Ground Calibration and Five Years in Flight

    CERN Document Server

    Canizares, C R; Dewey, D; Flanagan, K A; Galton, E B; Huenemoerder, D P; Ishibashi, K; Markert, T H; Marshall, H L; McGuirk, M; Schattenburg, M L; Schulz, N S; Smith, H I; Wise, M; Canizares, Claude R.; Davis, John E.; Dewey, Daniel; Flanagan, Kathryn A.; Galton, Eugene B.; Huenemoerder, David P.; Ishibashi, Kazunori; Markert, Thomas H.; Marshall, Herman L.; Guirk, Michael Mc; Schattenburg, Mark L.; Schulz, Norbert S.; Smith, Henry I.; Wise, Michael

    2005-01-01

    Details of the design, fabrication, ground and flight calibration of the High Energy Transmission Grating, HETG, on the Chandra X-ray Observatory are presented after five years of flight experience. Specifics include the theory of phased transmission gratings as applied to the HETG, the Rowland design of the spectrometer, details of the grating fabrication techniques, and the results of ground testing and calibration of the HETG. For nearly six years the HETG has operated essentially as designed, although it has presented some subtle flight calibration effects.

  11. New technique for fabrication of high frequency piezoelectric Micromachined Ultrasound Transducers

    DEFF Research Database (Denmark)

    Pedersen, T; Thomsen, Erik Vilain; Zawada, T

    2008-01-01

    A novel technique for fabrication of linear arrays of high frequency piezoelectric Micromachined Ultrasound Transducers (pMUT) on silicon substrates is presented. Piezoelectric elements are formed by deposition of PZT ((PbZrxTi1-x)O3) into etched features of the silicon substrate...... such that the depth of these features determine the element thickness and hence the resonance frequency. The process leaves a near planar surface which is ideal for further wafer level processing such as top electrode and interconnect formation. A fabricated single element is characterized by pulse echo response....

  12. High T(sub c) superconductors fabricated by plasma aerosol mist deposition technique

    Science.gov (United States)

    Wang, X. W.; Vuong, K. D.; Leone, A.; Shen, C. Q.; Williams, J.; Coy, M.

    1995-01-01

    We report new results on high T(sub c) superconductors fabricated by a plasma aerosol mist deposition technique, in atmospheric environment. Materials fabricated are YBaCuO, BiPbSrCaCuO, BaCaCuO precursor films for TlBaCaCuO, and other buffers such as YSZ. Depending on processing conditions, sizes of crystallites and/or particles are between dozens of nano-meters and several micrometers. Superconductive properties and other material characteristics can also be tailored.

  13. Improved Structure and Fabrication of Large, High-Power KHPS Rotors - Final Scientific/Technical Report

    Energy Technology Data Exchange (ETDEWEB)

    Corren, Dean [Verdant Power, Inc.; Colby, Jonathan [Verdant Power, Inc.; Adonizio, Mary Ann [Verdant Power, Inc.

    2013-01-29

    Verdant Power, Inc, working in partnership with the National Renewable Energy Laboratory (NREL), Sandia National Laboratories (SNL), and the University of Minnesota St. Anthony Falls Laboratory (SAFL), among other partners, used evolving Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEA) models and techniques to improve the structure and fabrication of large, high-power composite Kinetic Hydropower System (KHPS) rotor blades. The objectives of the project were to: design; analyze; develop for manufacture and fabricate; and thoroughly test, in the lab and at full scale in the water, the improved KHPS rotor blade.

  14. High-efficiency fabrication of aspheric microlens arrays by holographic femtosecond laser-induced photopolymerization

    Science.gov (United States)

    Hu, Yanlei; Chen, Yuhang; Ma, Jianqiang; Li, Jiawen; Huang, Wenhao; Chu, Jiaru

    2013-09-01

    Manufacture of aspheric microlens has always been technically challenging for conventional approaches due to their complex curved profile and tiny sizes. Two-photon polymerization is capable of producing arbitrary shape with high spatial resolution, apart from the disadvantage of ultra-low rate of yield resulting from point-by-point writing strategy. Here, we report parallel fabrication of aspheric microlens arrays (AMLAs) by taking advantage of holographic femtosecond laser direct-writing. The inherent constraints of the spatial light modulator are taken into consideration for achieving improved intensity uniformity and enhanced diffraction efficiency. Closely-packed AMLAs with designable optical parameters are readily fabricated with excellent optical performance.

  15. Fabrication of thin yttria-stabilized-zirconia dense electrolyte layers by inkjet printing for high performing solid oxide fuel cells

    DEFF Research Database (Denmark)

    Esposito, Vincenzo; Gadea, Christophe; Hjelm, Johan

    2015-01-01

    In this work, we present how a low-cost HP Deskjet 1000 inkjet printer was used to fabricate a 1.2 mm thin, dense and gas tight 16 cm2 solid oxide fuel cells (SOFC) electrolyte. The electrolyte was printed using an ink made of highly diluted (...) powders (50 nm in size) in an aqueous medium. The ink was designed to be a highly dispersed, long term stable colloidal suspension, with optimal printability characteristics. The electrolyte was made by a multiple printing procedure, which ensures coverage of the several flaws occurring in a single...... printing pass. Together with an optimized sintering procedure this resulted in good adhesion and densification of the electrolyte. The SOFC exhibited a close-to-theoretical open circuit voltage and a remarkable peak power density above 1.5 W cm-2 at 800 °C....

  16. Processing and Characterization of Peti Composites Fabricated by High Temperature Vartm (Section)

    Science.gov (United States)

    Ghose, Sayata; Cano, Roberto J.; Watson, Kent A.; Britton, Sean M.; Jensen, Brian J.; Connell, John W.; Smith, Joseph G., Jr.; Loos, Alfred C.; Heider, Dirk

    2011-01-01

    The use of composites as primary structures on aerospace vehicles has increased dramatically over the past decade, but so have the production costs associated with their fabrication. For certain composites, high temperature vacuum assisted resin transfer molding (HT-VARTM) can offer reduced fabrication costs compared to conventional autoclave techniques. The process has been successfully used with phenylethynyl terminated imide (PETI) resins developed by NASA Langley Research Center (LaRC). In the current study, three PETI resins have been used to make test specimens using HT-VARTM. Based on previous work at NASA LaRC, larger panels with a quasi-isotropic lay-up were fabricated. The resultant composite specimens exhibited void contents of 3% by volume depending on the type of carbon fabric preform used. Mechanical properties of the panels were determined at both room and elevated temperatures. Fabric permeability characterizations and limited process modeling efforts were carried out to determine infusion times and composite panel size limitations. In addition, new PETI based resins were synthesized specifically for HT-VARTM.

  17. Novel highly sensitive and wearable pressure sensors from conductive three-dimensional fabric structures

    Science.gov (United States)

    Li, Jianfeng; Xu, Bingang

    2015-12-01

    Pressure sensors based on three-dimensional fabrics have all the excellent properties of the textile substrate: excellent compressibility, good air permeability and moisture transmission ability, which will find applications ranging from the healthcare industry to daily usage. In this paper, novel pressure sensors based on 3D spacer fabrics have been developed by a proposed multi-coating method. By this coating method, carbon black can be coated uniformly on the silicon elastomer which is attached and slightly cured on the 3D fabric surface beforehand. The as-made pressure sensors have good conductivity and can measure external pressure up to 283 kPa with an electrical conductivity range of 9.8 kΩ. The sensitivity of 3D fabric pressure sensors can be as high as 50.31×10-3 kPa-1, which is better than other textile based pressure sensors. When the as-made sensors are pressed, their electrical resistance will decrease because of more conductive connections and bending of fibers in the spacer layer. The sensing mechanism related to fiber bending has been explored by using an equivalent resistance model. The newly developed 3D sensor devices can be designed to exhibit different sensing performances by simply changing the structures of fabric substrate, which endows this kind of device more flexibility in related applications.

  18. A novel approach for fabricating highly tunable and fluffy bioinspired 3D poly(vinyl alcohol) (PVA) fiber scaffolds.

    Science.gov (United States)

    Roy, Sunanda; Kuddannaya, Shreyas; Das, Tanya; Lee, Heng Yeong; Lim, Jacob; Hu, Xiao 'Matthew'; Chee Yoon, Yue; Kim, Jaehwan

    2017-06-01

    The excellent biocompatibility, biodegradability and chemo-thermal stability of poly(vinyl alcohol) (PVA) have been harnessed in diverse practical applications. These properties have motivated the fabrication of high performance PVA based nanofibers with adequate control over the micro and nano-architectures and surface chemical interactions. However, the high water solubility and hydrophilicity of the PVA polymer limits the application of the electrospun PVA nanofibers in aqueous environments owing to instantaneous dissolution. In this work, we report a novel yet facile concept for fabricating extremely light, fluffy, insoluble and stable three dimensional (3D) PVA fibrous scaffolds with/without coating for multifunctional purposes. While the solubility, morphology, fiber density and mechanical properties of nanofibers could be tuned by optimizing the cross-linking conditions, the surface chemical reactivity could be readily enhanced by coating with a polydopamine (pDA) bioinspired polymer without compromising the stability and innate properties of the native PVA fiber. The 3D pDA-PVA scaffolds exhibited super dye adsorption and constructive synergistic cell-material interactions by promoting healthy adhesion and viability of the human mesenchymal stem cells (hMSCs) within 3D micro-niches. We foresee the application of tunable PVA 3D as a highly adsorbent material and a scaffold material for tissue regeneration and drug delivery with close consideration of realistic in vivo parameters.

  19. Application of Inkjet Printing in High-Density Pixelated RGB Quantum Dot-Hybrid LEDs

    KAUST Repository

    Haverinen, Hanna

    2012-05-23

    Recently, an intriguing solution to obtain better color purity has been to introduce inorganic emissive quantum dots (QDs) into an otherwise OLED structure. The emphasis of this chapter is to present a simple discussion of the first attempts to fabricate high-density, pixelated (quarter video graphics array (QVGA) format), monochromatic and RGB quantum dots light-emitting diodes (QDLEDs), where inkjet printing is used to deposit the light-emitting layer of QDs. It shows some of the factors that have to be considered in order to achieve the desired accuracy and printing quality. The successful operation of the RGB printed devices indicates the potential of the inkjet printing approach in the fabrication of full-color QDLEDs for display application. However, further optimization of print quality is still needed in order to eliminate the formation of pinholes, thus maximizing energy transfer from organic layers to the QDs and in turn increasing the performance of the devices. Controlled Vocabulary Terms: ink jet printing; LED displays; LED lamps; organic light emitting diodes; quantum dots

  20. Nanoscale design of multifunctional organic layers for low-power high-density memory devices.

    Science.gov (United States)

    Nougaret, Laurianne; Kassa, Hailu G; Cai, Ronggang; Patois, Tilia; Nysten, Bernard; van Breemen, Albert J J M; Gelinck, Gerwin H; de Leeuw, Dago M; Marrani, Alessio; Hu, Zhijun; Jonas, Alain M

    2014-04-22

    We demonstrate the design of a multifunctional organic layer by the rational combination of nanosized regions of two functional polymers. Instead of relying on a spontaneous and random phase separation process or on the tedious synthesis of block copolymers, the method involves the nanomolding of a first component, followed by the filling of the resulting open spaces by a second component. We apply this methodology to fabricate organic nonvolatile memory diodes of high density. These are built by first creating a regular array of ferroelectric nanodots by nanoimprint lithography, followed by the filling of the trenches separating the ferroelectric nanodots with a semiconducting polymer. The modulation of the current in the semiconductor by the polarization state of the ferroelectric material is demonstrated both at the scale of a single semiconductor channel and in a microscopic device measuring about 80,000 channels in parallel, for voltages below ca. 2 V. The fabrication process, which combines synergetically orthogonal functional properties with a fine control over their spatial distribution, is thus demonstrated to be efficient over large areas.

  1. Design and fabrication of a passive droplet dispenser for portable high resolution imaging system

    Science.gov (United States)

    Kamal, Tahseen; Watkins, Rachel; Cen, Zijian; Rubinstein, Jaden; Kong, Gary; Lee, Woei Ming

    2017-01-01

    Moldless lens manufacturing techniques using standard droplet dispensing technology often require precise control over pressure to initiate fluid flow and control droplet formation. We have determined a series of interfacial fluid parameters optimised using standard 3D printed tools to extract, dispense and capture a single silicone droplet that is then cured to obtain high quality lenses. The dispensing process relies on the recapitulation of liquid dripping action (Rayleigh-Plateau instability) and the capturing method uses the interplay of gravitational force, capillary forces and liquid pinning to control the droplet shape. The key advantage of the passive lens fabrication approach is rapid scale-up using 3D printing by avoiding complex dispensing tools. We characterise the quality of the lenses fabricated using the passive approach by measuring wavefront aberration and high resolution imaging. The fabricated lenses are then integrated into a portable imaging system; a wearable thimble imaging device with a detachable camera housing, that is constructed for field imaging. This paper provides the full exposition of steps, from lens fabrication to imaging platform, necessary to construct a standalone high resolution imaging system. The simplicity of our methodology can be implemented using a regular desktop 3D printer and commercially available digital imaging systems.

  2. Fabrication of Aspheric Micro-Lens Mold with High Aspect Ratio

    Science.gov (United States)

    Naniwa, Irizo; Kanamaru, Masatoshi; Nakamura, Shigeo; Shimano, Takeshi; Horino, Masaya

    The optical pickup of our Small-Form-Factor Optical Disc Drives (SFFODDs) requires a micro-objective whose profile is composed of two aspheric surfaces. However, it is difficult to fabricate a micro-objective with an arbitrary aspheric surface and high aspect ratio using conventional techniques. We propose here a new method to fabricate an aspheric micro-lens mold with high aspect ratio. This method uses the micro-loading effect in Deep Reactive Ion Etching (DRIE) and isotropic Reactive Ion Etching (RIE). The micro-loading effect is a phenomenon that leads to different etching depths depending on the aperture size of the mask layer used in etching. We fabricated an aspheric micro-lens mold for the prototype by using the proposed method after experimental evaluations of the micro-loading effect for a feasibility study. The profile of the first prototype was slightly different from the designed one according as the distance from the lens center increase. The profile error of the second prototype was reduced by using a mask that had multiple apertures with the smallest aperture located outside the area where the crater was formed. Our proposed method was found to be effective for fabricating a micro-lens mold with an arbitrary aspheric surface and high aspect ratio.

  3. Design and fabrication of a passive droplet dispenser for portable high resolution imaging system

    Science.gov (United States)

    Kamal, Tahseen; Watkins, Rachel; Cen, Zijian; Rubinstein, Jaden; Kong, Gary; Lee, Woei Ming

    2017-01-01

    Moldless lens manufacturing techniques using standard droplet dispensing technology often require precise control over pressure to initiate fluid flow and control droplet formation. We have determined a series of interfacial fluid parameters optimised using standard 3D printed tools to extract, dispense and capture a single silicone droplet that is then cured to obtain high quality lenses. The dispensing process relies on the recapitulation of liquid dripping action (Rayleigh-Plateau instability) and the capturing method uses the interplay of gravitational force, capillary forces and liquid pinning to control the droplet shape. The key advantage of the passive lens fabrication approach is rapid scale-up using 3D printing by avoiding complex dispensing tools. We characterise the quality of the lenses fabricated using the passive approach by measuring wavefront aberration and high resolution imaging. The fabricated lenses are then integrated into a portable imaging system; a wearable thimble imaging device with a detachable camera housing, that is constructed for field imaging. This paper provides the full exposition of steps, from lens fabrication to imaging platform, necessary to construct a standalone high resolution imaging system. The simplicity of our methodology can be implemented using a regular desktop 3D printer and commercially available digital imaging systems. PMID:28128365

  4. On-chip Fabrication of High Performance Nanostructured ZnO UV Detectors

    Science.gov (United States)

    Alenezi, Mohammad R.; Henley, Simon J.; Silva, S. R. P.

    2015-02-01

    Developing rationally controlled bottom-up device fabrication processes is essential for the achievement of high performance optimal devices. We report a controlled, seedless and site-selective hydrothermal technique to fabricate high-performance nanostructured ZnO UV-detectors directly on-chip. We demonstrate that by controlling the nanowire growth process, via tuning the experimental parameters such as the concentration of reactants and the growth time, and by introducing a refresh of the growth solution, the device structure efficiency can be enhanced to significantly improve its performance. The on-chip fabricated bridging nanosyringe ultraviolet detector demonstrates improved sensitivity (~105), nanowatts detectability, and ultrafast response-time (90 ms) and recovery-time (210 ms). The improvement in response-time and recovery-time is attributed to the unique nanowire-nanowire junction barrier dominated resistance and the direct contact between ZnO and Au electrodes. Furthermore, the enhanced sensitivity and nanowatts detectability of the bridging nanosyringe device are due to the reduction in dimensionality and ultrahigh surface-to-volume ratio. This work paves the way toward low cost, large scale, low temperature, seedless and site-selective fabrication of high performance ZnO nanowire sensors on flexible and transparent substrates.

  5. Exploring high-density baryonic matter: Maximum freeze-out density

    Energy Technology Data Exchange (ETDEWEB)

    Randrup, Joergen [Lawrence Berkeley National Laboratory, Nuclear Science Division, Berkeley, CA (United States); Cleymans, Jean [University of Cape Town, UCT-CERN Research Centre and Department of Physics, Rondebosch (South Africa)

    2016-08-15

    The hadronic freeze-out line is calculated in terms of the net baryon density and the energy density instead of the usual T and μ{sub B}. This analysis makes it apparent that the freeze-out density exhibits a maximum as the collision energy is varied. This maximum freeze-out density has μ{sub B} = 400 - 500 MeV, which is above the critical value, and it is reached for a fixed-target bombarding energy of 20-30 GeV/N well within the parameters of the proposed NICA collider facility. (orig.)

  6. Development of high energy density electrical double layer capacitors

    Science.gov (United States)

    Devarajan, Thamarai selvi

    Electrochemical Double Layer capacitors (EDLCs) have shown themselves as a viable energy storage alternative. EDLCs have high power density, faster charge/discharge, wide operating temperature and long cycle life compared to batteries since it stores charge by physical separation. Despites all their advantages, their low energy density stand as a bottleneck for capacitors. This research aims to increase the energy density of EDLC without compromising the power density. Energy is proportional to the square of cell voltage. Cell voltage is mainly dependent on electrolyte breakdown. Electrolytes also provide ions for charge separation and conduction. Therefore various electrolytes (Solutes and Solvents) which can give high concentration, solubility and decomposition potential were characterized in the first part of the research. In that study, a novel ionic liquid OPBF4 had higher capacitance and comparable voltage window compared to commercial TEABF4 in Acetonitrile. However, the increased polarity of the fixed ring O-atom and the ion-ion interaction in OPBF4 was responsible for lowering its conductivity. Oxygenated ionic compounds with alkyl groups had lower stability due to beta elimination between two electron withdrawing atoms. Volume based thermodynamics and quantum chemical calculations were used to calculate ion size, HOMO/LUMO energies, and free energy changes and establish relationship with capacitance, redox potential and melting points respectively. In addition free energy of fusion was used to predict the melting point. Ion size had correlation with capacitance due to compact double layer formation. Free energy changes did not explain the differences in melting point and predicted dielectric constant was inconsistent with the polarity. This is presumably due to using Van der Waals volume instead of crystal structure volume and insufficient incorporation of polarization term. The HOMO/LUMO energies gave direct relation between oxidation and reduction

  7. High Stocking Density Controls Phillyrea Angustifolia in Mediterranean Grasslands

    Science.gov (United States)

    Mesléard, François; Yavercovski, Nicole; Lefebvre, Gaétan; Willm, Loic; Bonis, Anne

    2017-03-01

    Extensive grazing applied in the form of low instantaneous pressure over a long period is a widespread management practice in protected areas. However this kind of stocking method does not always achieve the expected results, in particular because it fails to limit colonization by woody plants.This is the case in the relict xero-halophytic grasslands of the northern Mediterranean coastal region, subjected to widespread colonization by the shrub Phillyrea angustifolia despite the presence of extensive grazing. In this study, we investigated, for an equal annual stocking rate, the respective impact of high stocking density applied over a short period (mob grazing) and low stocking density applied over a long period on both P. angustifolia and herbaceous cover, using an in situ experimental design run for 7 years. Only mob grazing was effective both in controlling the establishment and increasing the mortality of P. angustifolia individuals. We did not find any difference after the 7 years of experimentation between the two stocking methods with regard to the herbaceous community parameters tested: species richness, diversity, evenness, contribution of annual characteristic species. By contrast, the exclusion of domestic grazing led to a strong reduction of these values.The use of mob grazing may be well suited for meeting conservation goals such as maintaining open habitats in these grasslands.

  8. High density collinear holographic data storage system (Conference Presentation)

    Science.gov (United States)

    Tan, Xiaodi; Horimai, Hideyoshi; Arai, Ryo; Ikeda, Junichi; Inoue, Mitsuteru; Lin, Xiao; Xu, Ke; Liu, Jinpeng; Huang, Yong

    2016-09-01

    Collinear holography has been good candidate for a volumetric recording technology of holographic data storage system (HDSS), because of there are not only large storage capacities, high transfer rates, but also the unique configuration, in which the information and reference beams are modulated co-axially by the same spatial light modulator, as a new read/write method for HDSS are very promising. The optical pickup can be designed as small as DVDs, and can be placed on one side of the recording media (disc). In the disc structure, the preformatted reflective layer is used for the focus/tracking servo and reading address information, and a dichroic mirror layer is used for detecting holographic recording information without interfering with the preformatted information. A 2-dimensional digital page data format is used and the shift-multiplexing method is employed to increase recording density. As servo technologies are being introduced to control the objective lens to be maintained precisely to the disc in the recording and reconstructing process, a vibration isolator is no longer necessary. In this paper, we introduced the principle of the collinear holography and its media structure of disc. Some results of experimental and theoretical studies suggest that it is a very effective method. We also discussed some methods to increase the recording density and data transfer rates of collinear holography using phase modulated page data format.

  9. High Current Density 2D/3D Esaki Tunnel Diodes

    CERN Document Server

    Krishnamoorthy, Sriram; Lee, Choong Hee; Zhang, Yuewei; McCulloch, William D; Johnson, Jared M; Hwang, Jinwoo; Wu, Yiying; Rajan, Siddharth

    2016-01-01

    The integration of two-dimensional materials such as transition metal dichalcogenides with bulk semiconductors offer interesting opportunities for 2D/3D heterojunction-based novel device structures without any constraints of lattice matching. By exploiting the favorable band alignment at the GaN/MoS2 heterojunction, an Esaki interband tunnel diode is demonstrated by transferring large area, Nb-doped, p-type MoS2 onto heavily n-doped GaN. A peak current density of 446 A/cm2 with repeatable room temperature negative differential resistance, peak to valley current ratio of 1.2, and minimal hysteresis was measured in the MoS2/GaN non-epitaxial tunnel diode. A high current density of 1 kA/cm2 was measured in the Zener mode (reverse bias) at -1 V bias. The GaN/MoS2 tunnel junction was also modeled by treating MoS2 as a bulk semiconductor, and the electrostatics at the 2D/3D interface was found to be crucial in explaining the experimentally observed device characteristics.

  10. Formation of FRCs on the Pulsed High Density Experiment

    Science.gov (United States)

    Andreason, Samuel; Slough, John

    2008-11-01

    The Pulsed High Density (PHD) experiment has been reassembled at a new facility with sufficient space to continue through the full acceleration and compression stages to reach breakeven. The intention here is to produce a large FRC, but remain in the kinetic regime where the FRC is stable and the transport sufficiently low that a Q > 1 plasma can be attained at moderate densities ˜ 10^23 m-3. During reassembly a more complete analysis of previous experimental results has been made. One of the issues in the early phase of the experiment was inefficient flux trapping during field reversal due to the large scale of the FRC source (0.4 m radius). The on-axis seed plasma was unable to diffuse out to the walls on a timescale commensurate with the introduction of bias fields. This resulted in more than half of the initial bias flux lost before sheath formation halted flux loss. An annular array of plasma sources has been constructed that solves this problem and greatly enhances the flux retention. Dynamic formation has been employed on PHD and analysis tools capable of interpreting the magnetic loop diagnostic array have been developed. Results with comparison to numerical models will be presented.

  11. OLEOPHOBIC AND HYDROPHOBIC FEATURE EXPERIMENTS OF FLUORINATED HIGH DENSITY POLYETHYLENE

    Institute of Scientific and Technical Information of China (English)

    杨宏伟; 魏贤勇; 费逸伟; 孙世安; 李晓越

    2013-01-01

    The surface performances of directly fluorinated high density polyethylene (HDPE) are studied with Fourier transform infrared (FT-IR) spectra ,scanning electron microscopy (SEM) and contact angle (CA) system . The SEM images show that there is a three-layer structure called the reaction ,virgin and boundary layer structure . The depth of fluorinated layer is 5.75 μm with 1 h fluorination time and 7.86 μm with 2 h . The depths are 5.46 μm and 5.07 μm when fluorine density is 2% and 1% ,respectively .CA indicates that the HDPE surface property becomes more hydrophobic with the increasing water contact angle from 78.5° to 104.5° .Oleophobic and hydrophobic features of HDPE are identified by comparison of mass change experiments .It is shown that the in-crement rate of fluorinated HDPE is much lower than that of un-fluorinated HDPE filled in neither distilled water nor jet fuel .

  12. Realization of a diamond based high density multi electrode array by means of Deep Ion Beam Lithography

    Energy Technology Data Exchange (ETDEWEB)

    Picollo, F. [Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Torino (Italy); Physics Department and “NIS” Inter-departmental Centre, University of Torino, Torino (Italy); Consorzio Nazionale Inter-universitario per le Scienze fisiche della Materia (CNISM), Sezione di Torino, Torino (Italy); Battiato, A.; Bernardi, E. [Physics Department and “NIS” Inter-departmental Centre, University of Torino, Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Torino (Italy); Consorzio Nazionale Inter-universitario per le Scienze fisiche della Materia (CNISM), Sezione di Torino, Torino (Italy); Boarino, L.; Enrico, E. [Nanofacility Piemonte, National Institute of Metrologic Research (INRiM), Torino (Italy); Forneris, J.; Gatto Monticone, D.; Olivero, P. [Physics Department and “NIS” Inter-departmental Centre, University of Torino, Torino (Italy); Istituto Nazionale di Fisica Nucleare (INFN), Sezione di Torino, Torino (Italy); Consorzio Nazionale Inter-universitario per le Scienze fisiche della Materia (CNISM), Sezione di Torino, Torino (Italy)

    2015-04-01

    In the present work we report about a parallel-processing ion beam fabrication technique whereby high-density sub-superficial graphitic microstructures can be created in diamond. Ion beam implantation is an effective tool for the structural modification of diamond: in particular ion-damaged diamond can be converted into graphite, therefore obtaining an electrically conductive phase embedded in an optically transparent and highly insulating matrix. The proposed fabrication process consists in the combination of Deep Ion Beam Lithography (DIBL) and Focused Ion Beam (FIB) milling. FIB micromachining is employed to define micro-apertures in the contact masks consisting of thin (<10 μm) deposited metal layers through which ions are implanted in the sample. A prototypical single-cell biosensor was realized with the above described technique. The biosensor has 16 independent electrodes converging inside a circular area of 20 μm diameter (typical neuroendocrine cells size) for the simultaneous recording of amperometric signals.

  13. Realization of a diamond based high density multi electrode array by means of deep ion beam lithography

    CERN Document Server

    Picollo, Federico; Bernardi, Ettore; Boarino, Luca; Enrico, Emanuele; Forneris, Jacopo; Monticone, Daniele Gatto; Olivero, Paolo

    2014-01-01

    In the present work we report about a parallel-processing ion beam fabrication technique whereby high-density sub-superficial graphitic microstructures can be created in diamond. Ion beam implantation is an effective tool for the structural modification of diamond: in particular ion-damaged diamond can be converted into graphite, therefore obtaining an electrically conductive phase embedded in an optically transparent and highly insulating matrix. The proposed fabrication process consists in the combination of Deep Ion Beam Lithography (DIBL) and Focused Ion Beam (FIB) milling. FIB micromachining is employed to define micro-apertures in the contact masks consisting of thin (<10 um) deposited metal layers through which ions are implanted in the sample. A prototypical single-cell biosensor was realized with the above described technique. The biosensor has 16 independent electrodes converging inside a circular area of 20 um diameter (typical neuroendocrine cells size) for the simultaneous recording of amperom...

  14. High power density dc-to-dc converters for aerospace applications

    Science.gov (United States)

    Divan, Deepakraj M.

    1990-12-01

    Three dc-to-dc converter topologies aimed at high-power high-frequency applications are introduced. Major system parasitics, namely, the leakage inductance of the transformer and the device output capacitance are efficiently utilized. Of the three circuits, the single-phase and three-phase versions of the dual active bridge topology demonstrate minimal stresses, better utilization of the transformer, bidirectional, and buck-boost modes of operation. All circuits operate at a constant switching frequency, thus simplifying design of the reactive elements. The power transfer characteristics and soft-switching regions on the Vout-Iout plane are identified. Two coaxial transformers with different cross-sections were built for a rating of 50 kVA. Based on the single-phase dual active bridge topology, a 50 kW, 50 kHz converter operating at an input voltage of 200 Vdc and an output voltage of 1600 Vdc was fabricated. Characteristics of current-fed output make the dual active bridge topologies amenable to paralleling and hence extension to megawatt power levels. Projections to a 1 MW system operating from a 500 Vdc input, at an output voltage of 10 kVdc and a switching frequency of 50 kHz, using MOS-controlled thyristors, coaxially wound transformers operating at three times the present current density with cooling, and multilayer ceramic capacitors, suggests an overall power density of 0.075 to 0.08 kg/kW and an overall efficiency of 96 percent.

  15. Microsystem for remote sensing of high energy radiation with associated extremely low photon flux densities

    Science.gov (United States)

    Otten, A.; Jain, V. K.

    2015-08-01

    This paper presents a microsystem for remote sensing of high energy radiation in extremely low flux density conditions. With wide deployment in mind, potential applications range from nuclear non-proliferation, to hospital radiation-safety. The daunting challenge is the low level of photon flux densities - emerging from a Scintillation Crystal (SC) on to a ~1 mm-square detector, which are a factor of 10000 or so lower than those acceptable to recently reported photonic chips (including `single-photon detection' chips), due to a combination of low Lux, small detector size, and short duration SC output pulses - on the order of 1 μs. These challenges are attempted to be overcome by the design of an innovative `System on a Chip' type microchip, with high detector sensitivity, and effective coupling from the SC to the photodetector. The microchip houses a tiny n+ diff p-epi photodiode (PD) as well as the associated analog amplification and other related circuitry, all fabricated in 0.5micron, 3-metal 2-poly CMOS technology. The amplification, together with pulse-shaping of the photocurrent-induced voltage signal, is achieved through a tandem of two capacitively coupled, double-cascode amplifiers. Included in the paper are theoretical estimates and experimental results.

  16. High power density dc-to-dc converters for aerospace applications

    Science.gov (United States)

    Divan, Deepakraj M.

    1990-01-01

    Three dc-to-dc converter topologies aimed at high-power high-frequency applications are introduced. Major system parasitics, namely, the leakage inductance of the transformer and the device output capacitance are efficiently utilized. Of the three circuits, the single-phase and three-phase versions of the dual active bridge topology demonstrate minimal stresses, better utilization of the transformer, bidirectional, and buck-boost modes of operation. All circuits operate at a constant switching frequency, thus simplifying design of the reactive elements. The power transfer characteristics and soft-switching regions on the Vout-Iout plane are identified. Two coaxial transformers with different cross-sections were built for a rating of 50 kVA. Based on the single-phase dual active bridge topology, a 50 kW, 50 kHz converter operating at an input voltage of 200 Vdc and an output voltage of 1600 Vdc was fabricated. Characteristics of current-fed output make the dual active bridge topologies amenable to paralleling and hence extension to megawatt power levels. Projections to a 1 MW system operating from a 500 Vdc input, at an output voltage of 10 kVdc and a switching frequency of 50 kHz, using MOS-controlled thyristors, coaxially wound transformers operating at three times the present current density with cooling, and multilayer ceramic capacitors, suggests an overall power density of 0.075 to 0.08 kg/kW and an overall efficiency of 96 percent.

  17. Superhydrophilic-Superhydrophobic Patterned Surfaces as High-Density Cell Microarrays: Optimization of Reverse Transfection.

    Science.gov (United States)

    Ueda, Erica; Feng, Wenqian; Levkin, Pavel A

    2016-10-01

    High-density microarrays can screen thousands of genetic and chemical probes at once in a miniaturized and parallelized manner, and thus are a cost-effective alternative to microwell plates. Here, high-density cell microarrays are fabricated by creating superhydrophilic-superhydrophobic micropatterns in thin, nanoporous polymer substrates such that the superhydrophobic barriers confine both aqueous solutions and adherent cells within each superhydrophilic microspot. The superhydrophobic barriers confine and prevent the mixing of larger droplet volumes, and also control the spreading of droplets independent of the volume, minimizing the variability that arises due to different liquid and surface properties. Using a novel liposomal transfection reagent, ScreenFect A, the method of reverse cell transfection is optimized on the patterned substrates and several factors that affect transfection efficiency and cytotoxicity are identified. Higher levels of transfection are achieved on HOOC- versus NH2 -functionalized superhydrophilic spots, as well as when gelatin and fibronectin are added to the transfection mixture, while minimizing the amount of transfection reagent improves cell viability. Almost no diffusion of the printed transfection mixtures to the neighboring microspots is detected. Thus, superhydrophilic-superhydrophobic patterned surfaces can be used as cell microarrays and for optimizing reverse cell transfection conditions before performing further cell screenings. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. A Symmetrical, Planar SOFC Design for NASA's High Specific Power Density Requirements

    Science.gov (United States)

    Cable, Thomas L.; Sofie, Stephen W.

    2007-01-01

    Solid oxide fuel cell (SOFC) systems for aircraft applications require an order of magnitude increase in specific power density (1.0 kW/kg) and long life. While significant research is underway to develop anode supported cells which operate at temperatures in the range of 650-800 C, concerns about Cr-contamination from the metal interconnect may drive the operating temperature down further, to 750 C and lower. Higher temperatures, 900-1000 C, are more favorable for SOFC stacks to achieve specific power densities of 1.0 kW/kg. Since metal interconnects are not practical at these high temperatures and can account for up to 75% of the weight of the stack, NASA is pursuing a design that uses a thin, LaCrO3-based ceramic interconnect that incorporates gas channels into the electrodes. The bi-electrode supported cell (BSC) uses porous YSZ scaffolds, on either side of a 10-20 microns electrolyte. The porous support regions are fabricated with graded porosity using the freeze-tape casting process which can be tailored for fuel and air flow. Removing gas channels from the interconnect simplifies the stack design and allows the ceramic interconnect to be kept thin, on the order of 50 -100 microns. The YSZ electrode scaffolds are infiltrated with active electrode materials following the high temperature sintering step. The NASA-BSC is symmetrical and CTE matched, providing balanced stresses and favorable mechanical properties for vibration and thermal cycling.

  19. Giant-amplitude, high-work density microactuators with phase transition activated nanolayer bimorphs.

    Science.gov (United States)

    Liu, Kai; Cheng, Chun; Cheng, Zhenting; Wang, Kevin; Ramesh, Ramamoorthy; Wu, Junqiao

    2012-12-12

    Various mechanisms are currently exploited to transduce a wide range of stimulating sources into mechanical motion. At the microscale, simultaneously high amplitude, high work output, and high speed in actuation are hindered by limitations of these actuation mechanisms. Here we demonstrate a set of microactuators fabricated by a simple microfabrication process, showing simultaneously high performance by these metrics, operated on the structural phase transition in vanadium dioxide responding to diverse stimuli of heat, electric current, and light. In both ambient and aqueous conditions, the actuators bend with exceedingly high displacement-to-length ratios up to 1 in the sub-100 μm length scale, work densities over 0.63 J/cm(3), and at frequencies up to 6 kHz. The functionalities of actuation can be further enriched with integrated designs of planar as well as three-dimensional geometries. Combining the superior performance, high durability, diversity in responsive stimuli, versatile working environments, and microscale manufacturability, these actuators offer potential applications in microelectromechanical systems, microfluidics, robotics, drug delivery, and artificial muscles.

  20. Strongly interacting matter at high densities with a soliton model

    Science.gov (United States)

    Johnson, Charles Webster

    1998-12-01

    One of the major goals of modern nuclear physics is to explore the phase diagram of strongly interacting matter. The study of these 'extreme' conditions is the primary motivation for the construction of the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory which will accelerate nuclei to a center of mass (c.m.) energy of about 200 GeV/nucleon. From a theoretical perspective, a test of quantum chromodynamics (QCD) requires the expansion of the conditions examined from one phase point to the entire phase diagram of strongly-interacting matter. In the present work we focus attention on what happens when the density is increased, at low excitation energies. Experimental results from the Brookhaven Alternating Gradient Synchrotron (AGS) indicate that this regime may be tested in the 'full stopping' (maximum energy deposition) scenario achieved at the AGS having a c.m. collision energy of about 2.5 GeV/nucleon for two equal- mass heavy nuclei. Since the solution of QCD on nuclear length-scales is computationally prohibitive even on today's most powerful computers, progress in the theoretical description of high densities has come through the application of models incorporating some of the essential features of the full theory. The simplest such model is the MIT bag model. We use a significantly more sophisticated model, a nonlocal confining soliton model developed in part at Kent. This model has proven its value in the calculation of the properties of individual mesons and nucleons. In the present application, the many-soliton problem is addressed with the same model. We describe nuclear matter as a lattice of solitons and apply the Wigner-Seitz approximation to the lattice. This means that we consider spherical cells with one soliton centered in each, corresponding to the average properties of the lattice. The average density is then varied by changing the size of the Wigner-Seitz cell. To arrive at a solution, we need to solve a coupled set of

  1. A ferroelectric DRAM cell for high-density NVRAM's

    Science.gov (United States)

    Moazzami, Reza; Hu, Chenming; Shepherd, William H.

    1990-10-01

    The operation of a ferroelectric DRAM (dynamic random-access memory) cell for nonvolatile RAM (NVRAM) applications is described. Because polarization reversal only occurs during nonvolatile store/recall operations and not during read/write operations, ferroelectric fatigue is not a serious endurance problem. For a 3-V power supply, the worst-case effective silicon dioxide thickness of the unoptimized lead zirconate titanate film studied is less than 1.7 nm. The resistivity and endurance properties of ferroelectric films can be optimized by modifying the composition of the film. This cell can be the basis of a very-high-density NVRAM with practically no read/write cycle limit and at least 10 to the 10th nonvolatile store/recall cycles.

  2. [Cholesterol in serum high density lipoprotein fraction (author's transl)].

    Science.gov (United States)

    Schatz, C; Jeanblanc, B; Offner, M

    1980-11-22

    The risk of atheroma can be assessed and valid epidemiological surveys can be carried out by measuring cholesterol in serum high density lipoprotein fraction (HDL) and calculating the HDL cholesterol: VLDL + LDL ratio. This was done in 39 patients free from surgically confirmed atheromatous lesions and in 51 patients presenting with such lesions. Of the four different techniques used for separation in these patients (ultracentrifugation, precipitation with heparin-Mn2+, precipitation with phosphotungstate-Mg2+ and electrophoresis), precipitation with phosphotungstate-Mg/2+ seems to be the most suitable, since there is no degradation of the HDL fraction as during electrophoresis on polyacrylamide gel, and less floculation of the supernatant after separation. Contrary to ultracentrifugation, which requires sophisticated equipment and good technical skill, the technique is easily carried out.

  3. High-density polyethylene dosimetry by transvinylene FTIR analysis

    DEFF Research Database (Denmark)

    McLaughlin, W.L.; Silverman, J.; Al-Sheikhly, M.

    1999-01-01

    . The transvinylene response in air to gamma radiation is linear with dose and has relatively low yield compared with the response to electrons, whereas the response in deaerated polyethylene samples is also linear, but is more sensitive, and has negligible dose-rate dependence in its response to gamma rays...... and electrons. The useful dose range of 0.053 cm thick high-density polyethylene film (rho = 0.961 g cm(-3); melt index = 0.8 dg min(-1)), for irradiations by (60)Co gamma radiation and 2.0 and 0.4 MeV electron beams in deaerated atmosphere (Na gas), is about 50-10(3) kGy for FTIR transvinylene...

  4. 5th International conference on High Energy Density Laboratory Astrophysics

    CERN Document Server

    Kyrala, G.A

    2005-01-01

    During the past several years, research teams around the world have developed astrophysics-relevant utilizing high energy-density facilities such as intense lasers and z-pinches. Research is underway in many areas, such as compressible hydrodynamic mixing, strong shock phenomena, radiation flow, radiative shocks and jets, complex opacities, equations o fstat, and relativistic plasmas. Beyond this current research and the papers it is producing, plans are being made for the application, to astrophysics-relevant research, of the 2 MJ National Ignition Facility (NIF) laser at Lawrence Livermore National Laboratory; the 600 kj Ligne d'Intergration Laser (LIL) and the 2 MJ Laser Megajoule (LMJ) in Bordeaux, France; petawatt-range lasers now under construction around the world; and current and future Z pinches. The goal of this conference and these proceedings is to continue focusing and attention on this emerging research area. The conference brought together different scientists interested in this emerging new fi...

  5. Scoping study. High density polyethylene (HDPE) in salstone service

    Energy Technology Data Exchange (ETDEWEB)

    Phifer, Mark A. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2005-02-18

    An evaluation of the use of high density polyethylene (HDPE) geomembranes in Saltstone service has been conducted due to the potential benefits that could be derived from such usage. HDPE is one of the simplest hydrocarbon polymers and one of the most common polymers utilized in the production of geomembranes, which means that its costs are relatively low. Additionally, HDPE geomembranes have an extremely low permeability and an extremely low water vapor diffusional flux, which means that it is a good barrier to contaminant transport. The primary consideration in association with HDPE geomembranes in Saltstone service is the potential impact of Saltstone on the degradation of the HDPE geomembranes. Therefore, the evaluation documented herein has primarily focused upon the potential HDPE degradation in Saltstone service.

  6. The alterations in high density polyethylene properties with gamma irradiation

    Science.gov (United States)

    Zaki, M. F.; Elshaer, Y. H.; Taha, Doaa. H.

    2017-10-01

    In the present investigation, high density polyethylene (HDPE) polymer has been used to study the alterations in its properties under gamma-irradiation. Physico-chemical properties have been investigated with different spectroscopy techniques, Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction (XRD), biocompatibility properties, as well as, mechanical properties change. The FT-IR analysis shows the formation of new band at 1716 cm-1 that is attributed to the oxidation of irradiated polymer chains, which is due to the formation of carbonyl groups (C˭O). XRD patterns show that a decrease in the crystallite size and increase in the Full Width at Half Maximum (FWHM). This means that the crystallinity of irradiated samples is decreased with increase in gamma dose. The contact angle measurements show an increase in the surface free energy as the gamma irradiation increases. The measurements of mechanical properties of irradiated HDPE samples were discussed.

  7. Ultracold molecular Rydberg physics in a high density environment

    CERN Document Server

    Eiles, Matthew T; Robicheaux, F; Greene, Chris H

    2016-01-01

    Sufficiently high densities in Bose-Einstein condensates provide favorable conditions for the production of ultralong-range polyatomic molecules consisting of one Rydberg atom and a number of neutral ground state atoms. The chemical binding properties and electronic wave functions of these exotic molecules are investigated analytically via hybridized diatomic states. The effects of the molecular geometry on the system's properties are studied through comparisons of the adiabatic potential curves and electronic structures for both symmetric and randomly configured molecular geometries. General properties of these molecules with increasing numbers of constituent atoms and in different geometries are presented. These polyatomic states have spectral signatures that lead to non-Lorentzian line-profiles.

  8. Single-Readout High-Density Memristor Crossbar

    KAUST Repository

    Zidan, M. A.

    2016-01-07

    High-density memristor-crossbar architecture is a very promising technology for future computing systems. The simplicity of the gateless-crossbar structure is both its principal advantage and the source of undesired sneak-paths of current. This parasitic current could consume an enormous amount of energy and ruin the readout process. We introduce new adaptive-threshold readout techniques that utilize the locality and hierarchy properties of the computer-memory system to address the sneak-paths problem. The proposed methods require a single memory access per pixel for an array readout. Besides, the memristive crossbar consumes an order of magnitude less power than state-of-the-art readout techniques.

  9. Characterization of high density through silicon vias with spectral reflectometry.

    Science.gov (United States)

    Ku, Yi-Sha; Huang, Kuo Cheng; Hsu, Weite

    2011-03-28

    Measurement and control is an important step for production-worthy through silicon vias etch. We demonstrate the use and enhancement of an existing wafer metrology tool, spectral reflectometer by implementing novel theoretical model and measurement algorithm for high density through-silicon via (HDTSV) inspection. It is capable of measuring depth and depth variations of array vias by Discrete Fourier Transform (DFT) analysis in one shot measurement. Surface roughness of via bottom can also be extracted by scattering model fitting. Our non-destructive solution can measure TSV profile diameters as small as 5 μm and aspect ratios greater than 13:1. The measurement precision is in the range of 0.02 μm. Metrology results from actual 3D interconnect processing wafers are presented.

  10. Ultra-high current density thin-film Si diode

    Science.gov (United States)

    Wang, Qi

    2008-04-22

    A combination of a thin-film .mu.c-Si and a-Si:H containing diode structure characterized by an ultra-high current density that exceeds 1000 A/cm.sup.2, comprising: a substrate; a bottom metal layer disposed on the substrate; an n-layer of .mu.c-Si deposited the bottom metal layer; an i-layer of .mu.c-Si deposited on the n-layer; a buffer layer of a-Si:H deposited on the i-layer, a p-layer of .mu.c-Si deposited on the buffer layer; and a top metal layer deposited on the p-layer.

  11. Sulfurized activated carbon for high energy density supercapacitors

    Science.gov (United States)

    Huang, Yunxia; Candelaria, Stephanie L.; Li, Yanwei; Li, Zhimin; Tian, Jianjun; Zhang, Lili; Cao, Guozhong

    2014-04-01

    Sulfurized activated carbon (SAC), made by coating the pore surface with thiophenic sulfur functional groups from the pyrolysis of sulfur flakes, were characterized and tested for supercapacitor applications. From X-ray photoelectron spectroscopy (XPS), the sulfur content in the SAC was found to be 2.7 at%. Electrochemical properties from potentiostatic and galvanostatic measurements, and electrochemical impedance spectroscopy (EIS) were used to evaluate the effect of sulfur on porous carbon electrodes. The SAC electrode exhibits better conductivity, and an obvious increase in specific capacitance that is almost 40% higher than plain activated carbons (ACs) electrode at a high current density of 1.4 A g-1. The proposed mechanism for improved conductivity and capacitive performance due to the sulfur functional groups on ACs will be discussed.

  12. High-density avalanche chambers for positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Manfrass, P.; Enghardt, W.; Fromm, W.D.; Wohlfarth, D.; Hohmuth, K.

    1988-12-15

    A positron tomograph for radiopharmaceutical and medical research is under construction. In its final stage it will cover six high-density avalanche chambers (HIDAC) in a hexagonal arrangement. Each detector with a sensitive area of 50x28 cm/sup 2/ will consist of a stack of four pairs of multihole photon-to-electron converters with a multiwire proportional counter (MWPC) in between. An experimental investigation of detector properties as time and spatial resolutions as well as detector efficiency in dependence to converter structure, electric field strength and counting gas mixture preceded the final design of these detectors. Results of these studies are outlined. Furthermore, longitudinal tomograms taken with a stationary test camera are presented.

  13. High-density percutaneous chronic connector for neural prosthetics

    Science.gov (United States)

    Shah, Kedar G.; Bennett, William J.; Pannu, Satinderpall S.

    2015-09-22

    A high density percutaneous chronic connector, having first and second connector structures each having an array of magnets surrounding a mounting cavity. A first electrical feedthrough array is seated in the mounting cavity of the first connector structure and a second electrical feedthrough array is seated in the mounting cavity of the second connector structure, with a feedthrough interconnect matrix positioned between a top side of the first electrical feedthrough array and a bottom side of the second electrical feedthrough array to electrically connect the first electrical feedthrough array to the second electrical feedthrough array. The two arrays of magnets are arranged to attract in a first angular position which connects the first and second connector structures together and electrically connects the percutaneously connected device to the external electronics, and to repel in a second angular position to facilitate removal of the second connector structure from the first connector structure.

  14. CENTER FOR PULSED POWER DRIVEN HIGH ENERGY DENSITY PLASMA STUDIES

    Energy Technology Data Exchange (ETDEWEB)

    Professor Bruce R. Kusse; Professor David A. Hammer

    2007-04-18

    This annual report summarizes the activities of the Cornell Center for Pulsed-Power-Driven High-Energy-Density Plasma Studies, for the 12-month period October 1, 2005-September 30, 2006. This period corresponds to the first year of the two-year extension (awarded in October, 2005) to the original 3-year NNSA/DOE Cooperative Agreement with Cornell, DE-FC03-02NA00057. As such, the period covered in this report also corresponds to the fourth year of the (now) 5-year term of the Cooperative Agreement. The participants, in addition to Cornell University, include Imperial College, London (IC), the University of Nevada, Reno (UNR), the University of Rochester (UR), the Weizmann Institute of Science (WSI), and the P.N. Lebedev Physical Institute (LPI), Moscow. A listing of all faculty, technical staff and students, both graduate and undergraduate, who participated in Center research activities during the year in question is given in Appendix A.

  15. Thermolysis of High-Density Polyethylene to Petroleum Products

    Directory of Open Access Journals (Sweden)

    Sachin Kumar

    2013-01-01

    Full Text Available Thermal degradation of plastic polymers is becoming an increasingly important method for the conversion of plastic materials into valuable chemicals and oil products. In this work, virgin high-density polyethylene (HDPE was chosen as a material for pyrolysis. A simple pyrolysis reactor system has been used to pyrolyse virgin HDPE with an objective to optimize the liquid product yield at a temperature range of 400°C to 550°C. The chemical analysis of the HDPE pyrolytic oil showed the presence of functional groups such as alkanes, alkenes, alcohols, ethers, carboxylic acids, esters, and phenyl ring substitution bands. The composition of the pyrolytic oil was analyzed using GC-MS, and it was found that the main constituents were n-Octadecane, n-Heptadecane, 1-Pentadecene, Octadecane, Pentadecane, and 1-Nonadecene. The physical properties of the obtained pyrolytic oil were close to those of mixture of petroleum products.

  16. Personalized implant for high tibial opening wedge: combination of solid freeform fabrication with combustion synthesis process.

    Science.gov (United States)

    Zhim, Fouad; Ayers, Reed A; Moore, John J; Moufarrège, Richard; Yahia, L'Hocine

    2012-09-01

    In this work a new generation of bioceramic personalized implants were developed. This technique combines the processes of solid freeform fabrication (SFF) and combustion synthesis (CS) to create personalized bioceramic implants with tricalcium phosphate (TCP) and hydroxyapatite (HA). These porous bioceramics will be used to fill the tibial bone gap created by the opening wedge high tibial osteotomy (OWHTO). A freeform fabrication with three-dimensional printing (3DP) technique was used to fabricate a metallic mold with the same shape required to fill the gap in the opening wedge osteotomy. The mold was subsequently used in a CS process to fabricate the personalized ceramic implants with TCP and HA compositions. The mold geometry was designed on commercial 3D CAD software. The final personalized bioceramic implant was produced using a CS process. This technique was chosen because it exploits the exothermic reaction between P₂O₅ and CaO. Also, chemical composition and distribution of pores in the implant could be controlled. To determine the chemical composition, the microstructure, and the mechanical properties of the implant, cylindrical shapes were also fabricated using different fabrication parameters. Chemical composition was performed by X-ray diffraction. Pore size and pore interconnectivity was measured and analyzed using an electronic microscope system. Mechanical properties were determined by a mechanical testing system. The porous TCP and HA obtained have an open porous structure with an average 400 µm channel size. The mechanical behavior shows great stiffness and higher load to failure for both ceramics. Finally, this personalized ceramic implant facilitated the regeneration of new bone in the gap created by OWHTO and provides additional strength to allow accelerated rehabilitation.

  17. Fabrication of thermal-resistant gratings for high-temperature measurements using geometric phase analysis

    Science.gov (United States)

    Zhang, Q.; Liu, Z.; Xie, H.; Ma, K.; Wu, L.

    2016-12-01

    Grating fabrication techniques are crucial to the success of grating-based deformation measurement methods because the quality of the grating will directly affect the measurement results. Deformation measurements at high temperatures entail heating and, perhaps, oxidize the grating. The contrast of the grating lines may change during the heating process. Thus, the thermal-resistant capability of the grating becomes a point of great concern before taking measurements. This study proposes a method that combines a laser-engraving technique with the processes of particle spraying and sintering for fabricating thermal-resistant gratings. The grating fabrication technique is introduced and discussed in detail. A numerical simulation with a geometric phase analysis (GPA) is performed for a homogeneous deformation case. Then, the selection scheme of the grating pitch is suggested. The validity of the proposed technique is verified by fabricating a thermal-resistant grating on a ZrO2 specimen and measuring its thermal strain at high temperatures (up to 1300 °C). Images of the grating before and after deformation are used to obtain the thermal-strain field by GPA and to compare the results with well-established reference data. The experimental results indicate that this proposed technique is feasible and will offer good prospects for further applications.

  18. Thermoplastic elastomers for microfluidics: towards a high-throughput fabrication method of multilayered microfluidic devices.

    Science.gov (United States)

    Roy, Emmanuel; Galas, Jean-Christophe; Veres, Teodor

    2011-09-21

    Multilayer soft lithography of polydimethylsiloxane (PDMS) is a well-known method for the fabrication of complex fluidic functions. With advantages and drawbacks, this technique allows fabrication of valves, pumps and micro-mixers. However, the process is inadequate for industrial applications. Here, we report a rapid prototyping technique for the fabrication of multilayer microfluidic devices, using a different and promising class of polymers. Using styrenic thermoplastic elastomers (TPE), we demonstrate a rapid technique for the fabrication and assembly of pneumatically driven valves in a multilayer microfluidic device made completely from thermoplastics. This material solution is transparent, biocompatible and as flexible as PDMS, and has high throughput thermoforming processing characteristics. We established a proof of principle for valving and mixing with three different grades of TPE using an SU-8 master mold. Specific viscoelastic properties of each grade allow us to report enhanced bonding capabilities from room temperature bonding to free pressure thermally assisted bonding. In terms of microfabrication, beyond classically embossing means, we demonstrate a high-throughput thermoforming method, where TPE molding experiments have been carried out without applied pressure and vacuum assistance within an overall cycle time of 180 s. The quality of the obtained thermoplastic systems show robust behavior and an opening/closing frequency of 5 Hz.

  19. Fabrication of thermal-resistant gratings for high-temperature measurements using geometric phase analysis.

    Science.gov (United States)

    Zhang, Q; Liu, Z; Xie, H; Ma, K; Wu, L

    2016-12-01

    Grating fabrication techniques are crucial to the success of grating-based deformation measurement methods because the quality of the grating will directly affect the measurement results. Deformation measurements at high temperatures entail heating and, perhaps, oxidize the grating. The contrast of the grating lines may change during the heating process. Thus, the thermal-resistant capability of the grating becomes a point of great concern before taking measurements. This study proposes a method that combines a laser-engraving technique with the processes of particle spraying and sintering for fabricating thermal-resistant gratings. The grating fabrication technique is introduced and discussed in detail. A numerical simulation with a geometric phase analysis (GPA) is performed for a homogeneous deformation case. Then, the selection scheme of the grating pitch is suggested. The validity of the proposed technique is verified by fabricating a thermal-resistant grating on a ZrO2 specimen and measuring its thermal strain at high temperatures (up to 1300 °C). Images of the grating before and after deformation are used to obtain the thermal-strain field by GPA and to compare the results with well-established reference data. The experimental results indicate that this proposed technique is feasible and will offer good prospects for further applications.

  20. Extended MHD Effects in High Energy Density Experiments

    Science.gov (United States)

    Seyler, Charles

    2016-10-01

    The MHD model is the workhorse for computational modeling of HEDP experiments. Plasma models are inheritably limited in scope, but MHD is expected to be a very good model for studying plasmas at the high densities attained in HEDP experiments. There are, however, important ways in which MHD fails to adequately describe the results, most notably due to the omission of the Hall term in the Ohm's law (a form of extended MHD or XMHD). This talk will discuss these failings by directly comparing simulations of MHD and XMHD for particularly relevant cases. The methodology is to simulate HEDP experiments using a Hall-MHD (HMHD) code based on a highly accurate and robust Discontinuous Galerkin method, and by comparison of HMHD to MHD draw conclusions about the impact of the Hall term. We focus on simulating two experimental pulsed power machines under various scenarios. We examine the MagLIF experiment on the Z-machine at Sandia National Laboratories and liner experiments on the COBRA machine at Cornell. For the MagLIF experiment we find that power flow in the feed leads to low density plasma ablation into the region surrounding the liner. The inflow of this plasma compresses axial magnetic flux onto the liner. In MHD this axial flux tends to resistively decay, whereas in HMHD a force-free current layer sustains the axial flux on the liner leading to a larger ratio of axial to azimuthal flux. During the liner compression the magneto-Rayleigh-Taylor instability leads to helical perturbations due to minimization of field line bending. Simulations of a cylindrical liner using the COBRA machine parameters can under certain conditions exhibit amplification of an axial field due to a force-free low-density current layer separated by some distance from the liner. This results in a configuration in which there is predominately axial field on the liner inside the current layer and azimuthal field outside the layer. We are currently attempting to experimentally verify the simulation

  1. Modulation of low-density lipoprotein-induced inhibition of intercellular communication by antioxidants and high-density lipoproteins

    NARCIS (Netherlands)

    Zwijsen, R M; de Haan, L. H. J.; Kuivenhoven, J A; Nusselder, I C

    1991-01-01

    In order to study the capacity of antioxidants and high-density lipoproteins (HDL) to modulate the effects of low-density lipoprotein (LDL) on intercellular communication, arterial smooth muscle cells and a dye transfer method were used. LDL, in contrast to HDL, inhibited the communication between a

  2. Modulation of low-density lipoprotein-induced inhibition of intercellular communication by antioxidants and high-density lipoproteins

    NARCIS (Netherlands)

    Zwijsen, R M; de Haan, L. H. J.; Kuivenhoven, J A; Nusselder, I C

    In order to study the capacity of antioxidants and high-density lipoproteins (HDL) to modulate the effects of low-density lipoprotein (LDL) on intercellular communication, arterial smooth muscle cells and a dye transfer method were used. LDL, in contrast to HDL, inhibited the communication between

  3. High-temperature compatibility between liquid metal as PWR fuel gap filler and stainless steel and high-density concrete

    Science.gov (United States)

    Wongsawaeng, Doonyapong; Jumpee, Chayanit; Jitpukdee, Manit

    2014-08-01

    In conventional nuclear fuel rods for light-water reactors, a helium-filled as-fabricated gap between the fuel and the cladding inner surface accommodates fuel swelling and cladding creep down. Because helium exhibits a very low thermal conductivity, it results in a large temperature rise in the gap. Liquid metal (LM; 1/3 weight portion each of lead, tin, and bismuth) has been proposed to be a gap filler because of its high thermal conductivity (∼100 times that of He), low melting point (∼100 °C), and lack of chemical reactivity with UO2 and water. With the presence of LM, the temperature drop across the gap is virtually eliminated and the fuel is operated at a lower temperature at the same power output, resulting in safer fuel, delayed fission gas release and prevention of massive secondary hydriding. During normal reactor operation, should an LM-bonded fuel rod failure occurs resulting in a discharge of liquid metal into the bottom of the reactor pressure vessel, it should not corrode stainless steel. An experiment was conducted to confirm that at 315 °C, LM in contact with 304 stainless steel in the PWR water chemistry environment for up to 30 days resulted in no observable corrosion. Moreover, during a hypothetical core-melt accident assuming that the liquid metal with elevated temperature between 1000 and 1600 °C is spread on a high-density concrete basement of the power plant, a small-scale experiment was performed to demonstrate that the LM-concrete interaction at 1000 °C for as long as 12 h resulted in no penetration. At 1200 °C for 5 h, the LM penetrated a distance of ∼1.3 cm, but the penetration appeared to stop. At 1400 °C the penetration rate was ∼0.7 cm/h. At 1600 °C, the penetration rate was ∼17 cm/h. No corrosion based on chemical reactions with high-density concrete occurred, and, hence, the only physical interaction between high-temperature LM and high-density concrete was from tiny cracks generated from thermal stress. Moreover

  4. Flexible semi-transparent silicon (100) fabric with high-k/metal gate devices

    KAUST Repository

    Rojas, Jhonathan Prieto

    2013-01-07

    Can we build a flexible and transparent truly high performance computer? High-k/metal gate stack based metal-oxide-semiconductor capacitor devices are monolithically fabricated on industry\\'s most widely used low-cost bulk single-crystalline silicon (100) wafers and then released as continuous, mechanically flexible, optically semi-transparent and high thermal budget compatible silicon fabric with devices. This is the first ever demonstration with this set of materials which allows full degree of freedom to fabricate nanoelectronics devices using state-of-the-art CMOS compatible processes and then to utilize them in an unprecedented way for wide deployment over nearly any kind of shape and architecture surfaces. Electrical characterization shows uncompromising performance of post release devices. Mechanical characterization shows extra-ordinary flexibility (minimum bending radius of 1 cm) making this generic process attractive to extend the horizon of flexible electronics for truly high performance computers. Schematic and photograph of flexible high-k/metal gate MOSCAPs showing high flexibility and C-V plot showing uncompromised performance. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Numerical methods for high-dimensional probability density function equations

    Science.gov (United States)

    Cho, H.; Venturi, D.; Karniadakis, G. E.

    2016-01-01

    In this paper we address the problem of computing the numerical solution to kinetic partial differential equations involving many phase variables. These types of equations arise naturally in many different areas of mathematical physics, e.g., in particle systems (Liouville and Boltzmann equations), stochastic dynamical systems (Fokker-Planck and Dostupov-Pugachev equations), random wave theory (Malakhov-Saichev equations) and coarse-grained stochastic systems (Mori-Zwanzig equations). We propose three different classes of new algorithms addressing high-dimensionality: The first one is based on separated series expansions resulting in a sequence of low-dimensional problems that can be solved recursively and in parallel by using alternating direction methods. The second class of algorithms relies on truncation of interaction in low-orders that resembles the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) framework of kinetic gas theory and it yields a hierarchy of coupled probability density function equations. The third class of algorithms is based on high-dimensional model representations, e.g., the ANOVA method and probabilistic collocation methods. A common feature of all these approaches is that they are reducible to the problem of computing the solution to high-dimensional equations via a sequence of low-dimensional problems. The effectiveness of the new algorithms is demonstrated in numerical examples involving nonlinear stochastic dynamical systems and partial differential equations, with up to 120 variables.

  6. Numerical methods for high-dimensional probability density function equations

    Energy Technology Data Exchange (ETDEWEB)

    Cho, H. [Department of Mathematics, University of Maryland College Park, College Park, MD 20742 (United States); Venturi, D. [Department of Applied Mathematics and Statistics, University of California Santa Cruz, Santa Cruz, CA 95064 (United States); Karniadakis, G.E., E-mail: gk@dam.brown.edu [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States)

    2016-01-15

    In this paper we address the problem of computing the numerical solution to kinetic partial differential equations involving many phase variables. These types of equations arise naturally in many different areas of mathematical physics, e.g., in particle systems (Liouville and Boltzmann equations), stochastic dynamical systems (Fokker–Planck and Dostupov–Pugachev equations), random wave theory (Malakhov–Saichev equations) and coarse-grained stochastic systems (Mori–Zwanzig equations). We propose three different classes of new algorithms addressing high-dimensionality: The first one is based on separated series expansions resulting in a sequence of low-dimensional problems that can be solved recursively and in parallel by using alternating direction methods. The second class of algorithms relies on truncation of interaction in low-orders that resembles the Bogoliubov–Born–Green–Kirkwood–Yvon (BBGKY) framework of kinetic gas theory and it yields a hierarchy of coupled probability density function equations. The third class of algorithms is based on high-dimensional model representations, e.g., the ANOVA method and probabilistic collocation methods. A common feature of all these approaches is that they are reducible to the problem of computing the solution to high-dimensional equations via a sequence of low-dimensional problems. The effectiveness of the new algorithms is demonstrated in numerical examples involving nonlinear stochastic dynamical systems and partial differential equations, with up to 120 variables.

  7. Probucol alleviates atherosclerosis and improves high density lipoprotein function

    Directory of Open Access Journals (Sweden)

    Zhong Jian-Kai

    2011-11-01

    Full Text Available Abstract Background Probucol is a unique hypolipidemic agent that decreases high density lipoprotein cholesterol (HDL-C. However, it is not definite that whether probucol hinders the progression of atherosclerosis by improving HDL function. Methods Eighteen New Zealand White rabbits were randomly divided into the control, atherosclerosis and probucol groups. Control group were fed a regular diet; the atherosclerosis group received a high fat diet, and the probucol group received the high fat diet plus probucol. Hepatocytes and peritoneal macrophages were isolated for [3H] labeled cholesterol efflux rates and expression of ABCA1 and SR-B1 at gene and protein levels; venous blood was collected for serum paraoxonase 1, myeloperoxidase activity and lipid analysis. Aorta were prepared for morphologic and immunohistochemical analysis after 12 weeks. Results Compared to the atherosclerosis group, the paraoxonase 1 activity, cholesterol efflux rates, expression of ABCA1 and SR-BI in hepatocytes and peritoneal macrophages, and the level of ABCA1 and SR-BI in aortic lesions were remarkably improved in the probucol group, But the serum HDL cholesterol concentration, myeloperoxidase activity, the IMT and the percentage plaque area of aorta were significantly decreased. Conclusion Probucol alleviated atherosclerosis by improving HDL function. The mechanisms include accelerating the process of reverse cholesterol transport, improving the anti-inflammatory and anti-oxidant functions.

  8. Acrolein impairs the cholesterol transport functions of high density lipoproteins.

    Science.gov (United States)

    Chadwick, Alexandra C; Holme, Rebecca L; Chen, Yiliang; Thomas, Michael J; Sorci-Thomas, Mary G; Silverstein, Roy L; Pritchard, Kirkwood A; Sahoo, Daisy

    2015-01-01

    High density lipoproteins (HDL) are considered athero-protective, primarily due to their role in reverse cholesterol transport, where they transport cholesterol from peripheral tissues to the liver for excretion. The current study was designed to determine the impact of HDL modification by acrolein, a highly reactive aldehyde found in high abundance in cigarette smoke, on the cholesterol transport functions of HDL. HDL was chemically-modified with acrolein and immunoblot and mass spectrometry analyses confirmed apolipoprotein crosslinking, as well as acrolein adducts on apolipoproteins A-I and A-II. The ability of acrolein-modified HDL (acro-HDL) to serve as an acceptor of free cholesterol (FC) from COS-7 cells transiently expressing SR-BI was significantly decreased. Further, in contrast to native HDL, acro-HDL promotes higher neutral lipid accumulation in murine macrophages as judged by Oil Red O staining. The ability of acro-HDL to mediate efficient selective uptake of HDL-cholesteryl esters (CE) into SR-BI-expressing cells was reduced compared to native HDL. Together, the findings from our studies suggest that acrolein modification of HDL produces a dysfunctional particle that may ultimately promote atherogenesis by impairing functions that are critical in the reverse cholesterol transport pathway.

  9. SELDI-TOF mass spectrometry of High-Density Lipoprotein

    Directory of Open Access Journals (Sweden)

    Rezaee Farhad

    2007-09-01

    Full Text Available Abstract Background High-Density Lipoprotein (HDL, one of the main plasma lipoproteins, serves as a docking station for proteins involved in inflammation, coagulation, and lipid metabolism. Methods To elucidate the protein composition of HDL, we employed SELDI-TOF mass spectrometry as a potential high-throughput proteomic candidate for protein profiling of HDL. HDL derived from normolipemic individuals was captured on PS20 protein-chips using covalently bound antibodies against apo A-I or A-II. Results After optimisation, on-chip capture of HDL particles directly from plasma or from pre-purified HDL resulted in comparable fingerprints confirming specific capture of HDL. Depending on the capture antibody some differences in the fingerprint were observed. The most detailed fingerprint was observed up to 50 kDa; approximately 95 peaks were detected in the 3–50 kDa molecular mass range. Between 50 and 160 kDa, 27 more peaks were detected. Conclusion Based on these results, SELDI-TOF MS may be a suitable high-throughput candidate for HDL protein profiling and marker search. This approach may be used to i investigate the underlying mechanisms that lead to increased atherothrombotic risk and ii to investigate the atherothrombotic state of an individual.

  10. High-Density Infrared Surface Treatments of Refractories

    Energy Technology Data Exchange (ETDEWEB)

    Tiegs, T.N.

    2005-03-31

    Refractory materials play a crucial role in all energy-intensive industries and are truly a crosscutting technology for the Industries of the Future (IOF). One of the major mechanisms for the degradation of refractories and a general decrease in their performance has been the penetration and corrosion by molten metals or glass. Methods and materials that would reduce the penetration, wetting, and corrosive chemistry would significantly improve refractory performance and also maintain the quality of the processed liquid, be it metal or glass. This report presents the results of an R&D project aimed at investigating the use of high-density infrared (HDI) heating to surface treat refractories to improve their performance. The project was a joint effort between Oak Ridge National Laboratory (ORNL) and the University of Missouri-Rolla (UMR). HDI is capable of heating the near-surface region of materials to very high temperatures where sintering, diffusion, and melting can occur. The intended benefits of HDI processing of refractories were to (1) reduce surface porosity (by essentially sealing the surface to prevent liquid penetration), (2) allow surface chemistry changes to be performed by bonding an adherent coating onto the underlying refractory (in order to inhibit wetting and/or improve corrosion resistance), and (3) produce noncontact refractories with high-emissivity surface coatings.

  11. New high fill-factor triangular micro-lens array fabrication method using UV proximity printing

    CERN Document Server

    Lin, T -H; Chao, C -K

    2008-01-01

    A simple and effective method to fabricate a high fill-factor triangular microlens array using the proximity printing in lithography process is reported. The technology utilizes the UV proximity printing by controlling a printing gap between the mask and substrate. The designed approximate triangle microlens array pattern can be fabricated the high fill-factor triangular microlens array in photoresist. It is due to the UV light diffraction to deflect away from the aperture edges and produce a certain exposure in photoresist material outside the aperture edges. This method can precisely control the geometric profile of high fill factor triangular microlens array. The experimental results showed that the triangular micro-lens array in photoresist could be formed automatically when the printing gap ranged from 240 micrometers to 840 micrometers. The gapless triangular microlens array will be used to increases of luminance for backlight module of liquid crystal displays.

  12. Fabrication of a highly sensitive penicillin sensor based on charge transfer techniques.

    Science.gov (United States)

    Lee, Seung-Ro; Rahman, M M; Sawada, Kazuaki; Ishida, Makoto

    2009-03-15

    A highly sensitive penicillin biosensor based on a charge-transfer technique (CTTPS) has been fabricated and demonstrated in this paper. CTTPS comprised a charge accumulation technique for penicilloic acid and H(+) ions perception system. With the proposed CTTPS, it is possible to amplify the sensing signals without external amplifier by using the charge accumulation cycles. The fabricated CTTPS exhibits excellent performance for penicillin detection and exhibit a high-sensitivity (47.852 mV/mM), high signal-to-noise ratio (SNR), large span (1445 mV), wide linear range (0-25 mM), fast response time (penicillin sensor and exhibited almost eight times greater sensitivity as compared to ISFET (6.56 mV/mM). The sensor system is implemented for the measurement of the penicillin concentration in penicillin fermentation broth.

  13. High Electron Mobility Ge n-Channel Metal-Insulator-Semiconductor Field-Effect Transistors Fabricated by the Gate-Last Process with the Solid Source Diffusion Technique

    Science.gov (United States)

    Maeda, Tatsuro; Morita, Yukinori; Takagi, Shinichi

    2010-06-01

    We fabricate high-k/Ge n-channel metal-insulator-semiconductor field-effect transistors (MISFETs) by the gate-last process with the thermal solid source diffusion to achieve both of high quality source/drain (S/D) and gate stack. The n+/p junction formed by solid source diffusion technique of Sb dopant shows the excellent diode characteristics of ˜1.5×105 on/off ratio between +1 and -1 V and the quite low reverse current density of ˜4.1×10-4 A/cm2 at +1 V after the fabrication of high-k/Ge n-channel MISFETs that enable us to observe well-behaved transistor performances. The extracted electron mobility with the peak of 891 cm2/(V.s) is high enough to be superior to the Si universal electron mobility especially in low Eeff.

  14. Fabrication of high aspect ratio nanogrid transparent electrodes via capillary assembly of Ag nanoparticles

    Science.gov (United States)

    Kang, Juhoon; Park, Chang-Goo; Lee, Su-Han; Cho, Changsoon; Choi, Dae-Geun; Lee, Jung-Yong

    2016-05-01

    In this report, we describe the fabrication of periodic Ag nanogrid electrodes by capillary assembly of silver nanoparticles (AgNPs) along patterned nanogrid templates. By assembling the AgNPs into these high-aspect-ratio nanogrid patterns, we can obtain high-aspect-ratio nanogratings, which can overcome the inherent trade-off between the optical transmittance and the sheet resistance of transparent electrodes. The junction resistance between the AgNPs is effectively reduced by photochemical welding and post-annealing. The fabricated high-aspect-ratio nanogrid structure with a line width of 150 nm and a height of 450 nm has a sheet resistance of 15.2 Ω sq-1 and an optical transmittance of 85.4%.In this report, we describe the fabrication of periodic Ag nanogrid electrodes by capillary assembly of silver nanoparticles (AgNPs) along patterned nanogrid templates. By assembling the AgNPs into these high-aspect-ratio nanogrid patterns, we can obtain high-aspect-ratio nanogratings, which can overcome the inherent trade-off between the optical transmittance and the sheet resistance of transparent electrodes. The junction resistance between the AgNPs is effectively reduced by photochemical welding and post-annealing. The fabricated high-aspect-ratio nanogrid structure with a line width of 150 nm and a height of 450 nm has a sheet resistance of 15.2 Ω sq-1 and an optical transmittance of 85.4%. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01896c

  15. Weavable, Conductive Yarn-Based NiCo//Zn Textile Battery with High Energy Density and Rate Capability.

    Science.gov (United States)

    Huang, Yan; Ip, Wing Shan; Lau, Yuen Ying; Sun, Jinfeng; Zeng, Jie; Yeung, Nga Sze Sea; Ng, Wing Sum; Li, Hongfei; Pei, Zengxia; Xue, Qi; Wang, Yukun; Yu, Jie; Hu, Hong; Zhi, Chunyi

    2017-09-26

    With intrinsic safety and much higher energy densities than supercapacitors, rechargeable nickel/cobalt-zinc-based textile batteries are promising power sources for next generation personalized wearable electronics. However, high-performance wearable nickel/cobalt-zinc-based batteries are rarely reported because there is a lack of industrially weavable and knittable highly conductive yarns. Here, we use scalably produced highly conductive yarns uniformly covered with zinc (as anode) and nickel cobalt hydroxide nanosheets (as cathode) to fabricate rechargeable yarn batteries. They possess a battery level capacity and energy density, as well as a supercapacitor level power density. They deliver high specific capacity of 5 mAh cm(-3) and energy densities of 0.12 mWh cm(-2) and 8 mWh cm(-3) (based on the whole solid battery). They exhibit ultrahigh rate capabilities of 232 C (liquid electrolyte) and 116 C (solid electrolyte), which endows the batteries excellent power densities of 32.8 mW cm(-2) and 2.2 W cm(-3) (based on the whole solid battery). These are among the highest values reported so far. A wrist band battery is further constructed by using a large conductive cloth woven from the conductive yarns by a commercial weaving machine. It powers various electronic devices successfully, enabling dual functions of wearability and energy storage.

  16. High-power and high-energy-density flexible pseudocapacitor electrodes made from porous CuO nanobelts and single-walled carbon nanotubes.

    Science.gov (United States)

    Zhang, Xiaojun; Shi, Wenhui; Zhu, Jixin; Kharistal, Daniel Julian; Zhao, Weiyun; Lalia, Boor Singh; Hng, Huey Hoon; Yan, Qingyu

    2011-03-22

    We report a simple wet-chemical process to prepare porous CuO nanobelts (NBs) with high surface area and small crystal grains. These CuO NBs were mixed with carbon nanotubes in an appropriate ratio to fabricate pseudocapacitor electrodes with stable cycling performances, which showed a series of high energy densities at different power densities, for example, 130.2, 92, 44, 25, and 20.8 W h kg(-1) at power densities of 1.25, 6.25, 25, and 50 k Wh kg(-1), respectively. CuO-on-single-walled carbon nanotube (SWCNT) flexible hybrid electrodes were also fabricated using the SWCNT films as current collectors. These flexible electrodes showed much higher specific capacitance than that of electrodes made of pure SWCNTs and exhibited more stable cycling performance, for example, effective specific capacitances of >62 F g(-1) for the hybrid electrodes after 1000 cycles in 1 M LiPF6/EC:DEC at a current density of 5 A g(-1) and specific capacitance of only 23.6 F g(-1) for pure SWCNT electrodes under the same testing condition.

  17. Cyclic Oxidation of High Mo, Reduced Density Superalloys

    Directory of Open Access Journals (Sweden)

    James L. Smialek

    2015-11-01

    Full Text Available Cyclic oxidation was characterized as part of a statistically designed, 12-alloy compositional study of 2nd generation single crystal superalloys as part of a broader study to co-optimize density, creep strength, and cyclic oxidation. The primary modification was a replacement of 5 wt. % W by 7% or 12% Mo for density reductions of 2%–7%. Compositions at two levels of Mo, Cr, Co, and Re were produced, along with a midpoint composition. Initially, polycrystalline vacuum induction samples were screened in 1100 °C cyclic furnace tests using 1 h cycles for 200 h. The behavior was primarily delimited by Cr content, producing final weight changes of −40 mg/cm2 to −10 mg/cm2 for 0% Cr alloys and −2 mg/cm2 to +1 mg/cm2 for 5% Cr alloys. Accordingly, a multiple linear regression fit yielded an equation showing a strong positive Cr effect and lesser negative effects of Co and Mo. The results for 5% Cr alloys compare well to −1 mg/cm2, and +0.5 mg/cm2 for Rene′ N4 and Rene′ N5 (or Rene′ N6, respectively. Scale phases commonly identified were Al2O3, NiAl2O4, NiTa2O6, and NiO, with (Ni,CoMoO4 found only on the least resistant alloys having 0% Cr and 12% Mo. Scale microstructures were complex and reflected variations in the regional spallation history. Large faceted NiO grains and fine NiTa2O6 particles distributed along NiAl2O4 grain boundaries were typical distinctive features. NiMoO4 formation, decomposition, and volatility occurred for a few high Mo compositions. A creep, density, phase stability, and oxidation balanced 5% Cr, 10% Co, 7% Mo, and 3% Re alloy was selected to be taken forward for more extensive evaluations in single crystal form.

  18. Effects of gamma irradiation on polypropylene, polypropylene + high density polyethylene and polypropylene + high density polyethylene + wood flour

    Energy Technology Data Exchange (ETDEWEB)

    Reyes, J.; Albano, C.; Davidson, E.; Poleo, R. [Universidad Central de Venezuela, Caracas (Venezuela). Escuela de Quimica; Gonzalez, J.; Ichazo, M. [Universidad Simon Bolivar, Dept. de Mecanica, Caracas (Venezuela); Chipara, M. [Research Institute for Electrotechnics, Bucharest (Romania)

    2001-04-01

    The effect of the gamma-irradiation on the mechanical properties of the composites, Polypropylene (PP), PP+high density Polyethylene (HDPE), PP+ HDPE+wood flour, where HDPE is virgin and recycled, was studied. This paper discusses the behavior of the composites after exposure to various doses of gamma irradiation (1-7 MRads) in the presence of oxygen. The dependence of mechanical properties on the integral dose for a constant dose rate of 0.48 MRads/h confirms the influence of the irradiation. Strong effects on the elongation at break and break strength is noticed. The mathematical analysis suggests for the PP+r-HDPE a bimolecular process of the elongation at break. On the order hand, for the PP+HDPE a complex process is represented for a three exponential equation. (orig.)

  19. Individual tree detection based on densities of high points of high resolution airborne lidar

    NARCIS (Netherlands)

    Abd Rahman, M.Z.; Gorte, B.G.H.

    2008-01-01

    The retrieval of individual tree location from Airborne LiDAR has focused largely on utilizing canopy height. However, high resolution Airborne LiDAR offers another source of information for tree detection. This paper presents a new method for tree detection based on high points’ densities from a

  20. Tree crown delineation from high resolution airborne LiDAR based on densities of high points

    NARCIS (Netherlands)

    Rahman, M.Z.A.; Gorte, B.G.H.

    2009-01-01

    Tree detection and tree crown delineation from Airborne LiDAR has been focusing mostly on utilizing the canopy height model (CHM). This paper presents a method for individual tree crown delineation based on densities of high points (DHP) from the high resolution Airborne LiDAR. The DHP method relies