Sample records for bulk heterojunction bhj

  1. Inorganic Nanocrystal Bulk Heterojunctions - Energy Innovation...

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

    Solar Photovoltaic Solar Photovoltaic Find More Like This Return to Search Inorganic Nanocrystal Bulk Heterojunctions Brookhaven National Laboratory Contact BNL About This...

  2. The influence of molecular orientation on organic bulk heterojunction...

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

    The influence of molecular orientation on organic bulk heterojunction solar cells The influence of molecular orientation on organic bulk heterojunction solar cells Print Monday, 28...

  3. Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical...

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

    Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical Investigation Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical Investigation Print Wednesday,...

  4. Organic hybrid planar-nanocrystalline bulk heterojunctions

    DOE Patents [OSTI]

    Forrest, Stephen R. (Ann Arbor, MI); Yang, Fan (Piscataway, NJ)

    2011-03-01T23:59:59.000Z

    A photosensitive optoelectronic device having an improved hybrid planar bulk heterojunction includes a plurality of photoconductive materials disposed between the anode and the cathode. The photoconductive materials include a first continuous layer of donor material and a second continuous layer of acceptor material. A first network of donor material or materials extends from the first continuous layer toward the second continuous layer, providing continuous pathways for conduction of holes to the first continuous layer. A second network of acceptor material or materials extends from the second continuous layer toward the first continuous layer, providing continuous pathways for conduction of electrons to the second continuous layer. The first network and the second network are interlaced with each other. At least one other photoconductive material is interspersed between the interlaced networks. This other photoconductive material or materials has an absorption spectra different from the donor and acceptor materials.

  5. Organic hybrid planar-nanocrystalline bulk heterojunctions

    DOE Patents [OSTI]

    Forrest, Stephen R.; Yang, Fan

    2013-04-09T23:59:59.000Z

    A photosensitive optoelectronic device having an improved hybrid planar bulk heterojunction includes a plurality of photoconductive materials disposed between the anode and the cathode. The photoconductive materials include a first continuous layer of donor material and a second continuous layer of acceptor material. A first network of donor material or materials extends from the first continuous layer toward the second continuous layer, providing continuous pathways for conduction of holes to the first continuous layer. A second network of acceptor material or materials extends from the second continuous layer toward the first continuous layer, providing continuous pathways for conduction of electrons to the second continuous layer. The first network and the second network are interlaced with each other. At least one other photoconductive material is interspersed between the interlaced networks. This other photoconductive material or materials has an absorption spectra different from the donor and acceptor materials.

  6. Incomplete Exciton Harvesting from Fullerenes in Bulk Heterojunction Solar

    E-Print Network [OSTI]

    McGehee, Michael

    Incomplete Exciton Harvesting from Fullerenes in Bulk Heterojunction Solar Cells George F. Burkhard generation (absorp- tion), exciton harvesting (the process of excitons migrating to the donor materials decay radiatively, so exciton harvesting is usually evaluated by observing photolumines- cence

  7. Material Profile Influences in Bulk-Heterojunctions

    SciTech Connect (OSTI)

    Roehling, John D.; Rochester, Christopher W.; Ro, Hyun W.; Wang, Peng; Majewski, Jaroslaw; Batenburg, Kees J.; Arslan, Ilke; Delongchamp, Dean M.; Moule, Adam J.

    2014-10-01T23:59:59.000Z

    he morphology in mixed bulk-heterojunction films are compared using three different quantitative measurement techniques. We compare the vertical composition changes using high-angle annular dark-field scanning transmission electron microscopy with electron tomography and neutron and x-ray reflectometry. The three measurement techniques yield qualita-tively comparable vertical concentration measurements. The presence of a metal cathode during thermal annealing is observed to alter the fullerene concentration throughout the thickness of the film for all measurements. However, the abso-lute vertical concentration of fullerene is quantitatively different for the three measurements. The origin of the quantitative measurement differences is discussed. The authors thank Luna Innovations, Inc. for donating the endohedral fullerenes used in this study and Plextronics for the P3HT. They are gratefully thank the National Science Foundation Energy for Sustainability Program, Award No. 0933435. This work benefited from the use of the Lujan Neutron Scattering Center at Los Alamos Neutron Science Center funded by the DOE Office of Basic Energy Sciences and Los Alamos National Laboratory under DOE Contract DE-AC52-06NA25396. This research was also supported in part by Laboratory Directed Research & Development program at PNNL. The Pacific Northwest National Laboratory is operated by Battelle for the US Department of Energy under contract DE-AC05-76RL01830.

  8. Selective observation of photo-induced electric fields inside different material components in bulk-heterojunction organic solar cell

    SciTech Connect (OSTI)

    Chen, Xiangyu; Taguchi, Dai; Manaka, Takaaki; Iwamoto, Mitsumasa, E-mail: iwamoto@pe.titech.ac.jp [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1, S3-33 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)] [Department of Physical Electronics, Tokyo Institute of Technology, 2-12-1, S3-33 O-okayama, Meguro-ku, Tokyo 152-8552 (Japan)

    2014-01-06T23:59:59.000Z

    By using electric-field-induced optical second-harmonic generation (EFISHG) measurement at two laser wavelengths of 1000?nm and 860?nm, we investigated carrier behavior inside the pentacene and C{sub 60} component of co-deposited pentacene:C{sub 60} bulk-heterojunctions (BHJs) organic solar cells (OSCs). The EFISHG experiments verified the presence of two carrier paths for electrons and holes in BHJs OSCs. That is, two kinds of electric fields pointing in opposite directions are identified as a result of the selectively probing of SHG activation from C{sub 60} and pentacene. Also, under open-circuit conditions, the transient process of the establishment of open-circuit voltage inside the co-deposited layer has been directly probed, in terms of photovoltaic effect. The EFISHG provides an additional promising method to study carrier path of electrons and holes as well as dissociation of excitons in BHJ OSCs.

  9. Method of fabricating an optoelectronic device having a bulk heterojunction

    DOE Patents [OSTI]

    Shtein, Max (Ann Arbor, MI); Yang, Fan (Princeton, NJ); Forrest, Stephen R. (Princeton, NJ)

    2008-10-14T23:59:59.000Z

    A method of fabricating an optoelectronic device comprises: depositing a first layer having protrusions over a first electrode, in which the first layer comprises a first organic small molecule material; depositing a second layer on the first layer such that the second layer is in physical contact with the first layer; in which the smallest lateral dimension of the protrusions are between 1 to 5 times the exciton diffusion length of the first organic small molecule material; and depositing a second electrode over the second layer to form the optoelectronic device. A method of fabricating an organic optoelectronic device having a bulk heterojunction is also provided and comprises: depositing a first layer with protrusions over an electrode by organic vapor phase deposition; depositing a second layer on the first layer where the interface of the first and second layers forms a bulk heterojunction; and depositing another electrode over the second layer.

  10. Method of fabricating an optoelectronic device having a bulk heterojunction

    DOE Patents [OSTI]

    Shtein, Max (Princeton, NJ); Yang, Fan (Princeton, NJ); Forrest, Stephen R. (Princeton, NJ)

    2008-09-02T23:59:59.000Z

    A method of fabricating an organic optoelectronic device having a bulk heterojunction comprises the steps of: depositing a first layer over a first electrode by organic vapor phase deposition, wherein the first layer comprises a first organic small molecule material; depositing a second layer on the first layer such that the second layer is in physical contact with the first layer, wherein the interface of the second layer on the first layer forms a bulk heterojunction; and depositing a second electrode over the second layer to form the optoelectronic device. In another embodiment, a first layer having protrusions is deposited over the first electrode, wherein the first layer comprises a first organic small molecule material. For example, when the first layer is an electron donor layer, the first electrode is an anode, the second layer is an electron acceptor layer, and the second electrode is a cathode. As a further example, when the first layer is an electron acceptor layer, the first electrode is a cathode, the second layer is an electron donor layer, and the second electrode is an anode.

  11. Sputtered Nickel Oxide Thin Film for Efficient Hole Transport Layer in Polymer-Fullerene Bulk-Heterojunction Organic Solar Cell

    SciTech Connect (OSTI)

    Widjonarko, N. E.; Ratcliff, E. L.; Perkins, C. L.; Sigdel, A. K.; Zakutayev, A.; Ndione, P. F.; Gillaspie, D. T.; Ginley, D. S.; Olson, D. C.; Berry, J. J.

    2012-03-01T23:59:59.000Z

    Bulk-heterojunction (BHJ) organic photovoltaics (OPV) are very promising thin film renewable energy conversion technologies due to low production cost by high-throughput roll-to-roll manufacturing, an expansive list of compatible materials, and flexible device fabrication. An important aspect of OPV device efficiency is good contact engineering. The use of oxide thin films for this application offers increased design flexibility and improved chemical stability. Here we present our investigation of radio frequency magnetron sputtered nickel oxide (NiO{sub x}) deposited from oxide targets as an efficient, easily scalable hole transport layer (HTL) with variable work-function, ranging from 4.8 to 5.8 eV. Differences in HTL work-function were not found to result in statistically significant changes in open circuit voltage (V{sub oc}) for poly(3-hexylthiophene):[6,6]-phenyl-C{sub 61}-butyric acid methyl ester (P3HT:PCBM) BHJ device. Ultraviolet photoemission spectroscopy (UPS) characterization of the NiO{sub x} film and its interface with the polymer shows Fermi level alignment of the polymer with the NiO{sub x} film. UPS of the blend also demonstrates Fermi level alignment of the organic active layer with the HTL, consistent with the lack of correlation between V{sub oc} and HTL work-function. Instead, trends in j{sub sc}, V{sub oc}, and thus overall device performance are related to the surface treatment of the HTL prior to active layer deposition through changes in active layer thickness.

  12. MORPHOLOGY DEPENDENT SHORT CIRCUIT CURRENT IN BULK HETEROJUNCTION SOLAR CELL

    E-Print Network [OSTI]

    Alam, Muhammad A.

    of the coupled exciton/electron/hole flow in the disordered polymer network, but also guarantees to connect kinetics appears complex and final structure is randomly interpenetrating clusters of polymer and fullerene, West Lafayette, Indiana, USA ABSTRACT Polymer based bulk heterostructure (BH) solar cell offers

  13. Characterization of the Polymer Energy Landscape in Polymer:Fullerene Bulk Heterojunctions with Pure and Mixed Phases

    E-Print Network [OSTI]

    McGehee, Michael

    Characterization of the Polymer Energy Landscape in Polymer:Fullerene Bulk Heterojunctions with Pure and Mixed Phases Sean Sweetnam, Kenneth R. Graham,, Guy O. Ngongang Ndjawa, Thomas Heumuller offsets between the charge transport energy levels in different morphological phases of polymer

  14. Solvent polarity and nanoscale morphology in bulk heterojunction organic solar cells: A case study

    SciTech Connect (OSTI)

    Thomas, Ajith [Centre for Nano-Bio-Polymer Science and Technology, Department of Physics, St. Thomas College, Pala, Kerala 686574 (India); Research and Development Centre, Bharathiar University, Coimbatore, Tamilnadu 641046 (India); Elsa Tom, Anju; Ison, V. V., E-mail: isonvv@yahoo.in, E-mail: praveen@materials.iisc.ernet.in [Centre for Nano-Bio-Polymer Science and Technology, Department of Physics, St. Thomas College, Pala, Kerala 686574 (India); Rao, Arun D.; Varman, K. Arul; Ranjith, K.; Ramamurthy, Praveen C., E-mail: isonvv@yahoo.in, E-mail: praveen@materials.iisc.ernet.in [Department of Materials Engineering, Indian Institute of Science Bangalore, Karnataka 560012 (India); Vinayakan, R. [Department of Chemistry, SVR NSS College Vazhoor, Kerala 686505 (India)

    2014-03-14T23:59:59.000Z

    Organic bulk heterojunction solar cells were fabricated under identical experimental conditions, except by varying the solvent polarity used for spin coating the active layer components and their performance was evaluated systematically. Results showed that presence of nitrobenzene-chlorobenzene composition governs the morphology of active layer formed, which is due to the tuning of solvent polarity as well as the resulting solubility of the P3HT:PCBM blend. Trace amount of nitrobenzene favoured the formation of better organised P3HT domains, as evident from conductive AFM, tapping mode AFM and surface, and cross-sectional SEM analysis. The higher interfacial surface area thus generated produced cells with high efficiency. But, an increase in the nitrobenzene composition leads to a decrease in cell performance, which is due to the formation of an active layer with larger size polymer domain networks with poor charge separation possibility.

  15. End-Capping Effect of a Narrow Bandgap Conjugated Polymer on Bulk Heterojunction Solar Cells

    SciTech Connect (OSTI)

    Park, Jin Kuen [Univ. of California, Santa Barbara, CA (United States); Jo, Jang [Univ. of California, Santa Barbara, CA (United States); Seo, Jung Hwa [Univ. of California, Santa Barbara, CA (United States); Moon, Ji Seo [Univ. of California, Santa Barbara, CA (United States); Park, Yeong Don [Univ. of California, Santa Barbara, CA (United States); Lee, Kwanghee [Gwangiu Inst. of Science and Technology (Korea); Heeger, Alan J. [Univ. of California, Santa Barbara, CA (United States); Bazan, Guillermo C. [Univ. of California, Santa Barbara, CA (United States)

    2011-06-03T23:59:59.000Z

    Device performances of BHJ solar cells based on poly[(4,4-didodecyldithieno[3,2-b:2’,3’-d]silole)-2,6-diyl-alt-(2,1,3-benzoxadiazole)-4,7-diyl]and PC??BM improve by capping the chain ends with thiophene fragments. This structural modification yields materials that are more thermally robust and that can be used in devices with thicker films – important considerations for enabling the mass production of plastic solar cells.

  16. Ferroelectric field effect of the bulk heterojunction in polymer solar cells

    SciTech Connect (OSTI)

    Li, Meng; Ma, Heng, E-mail: hengma@henannu.edu.cn; Liu, Hairui; Jiang, Yurong [College of Physics and Electronic Engineering, Henan Normal University, Xinxiang 453007 (China); Henan Key Laboratory of Photovoltaic Materials, Xinxiang 453007 (China); Niu, Heying; Amat, Adil [College of Physics and Electronic Engineering, Henan Normal University, Xinxiang 453007 (China)

    2014-06-23T23:59:59.000Z

    A ferroelectric field effect in the bulk heterojunction was found when an external electric field (EEF) was applied on the active layer of polymer solar cells (PSCs) during the annealing process of the active layer spin-coated with poly(3-hexylthiophene):[6,6]-phenyl-C{sub 61} butyric acid methyl ester. For one direction field, the short circuit current density of PSCs was improved from 7.2 to 8.0?mA/cm{sup 2}, the power conversion efficiency increased from 2.4% to 2.8%, and the incident photon-to-current conversion efficiency increased from 42% to 49% corresponding to the different EEF magnitude. For an opposite direction field, the applied EEF brought a minus effect on the performance mentioned above. EEF treatment can orientate molecular ordering of the polymer, and change the morphology of the active layer. The authors suggest a explanation that the ferroelectric field has been built in the active layer, and therefore it plays a key role in PSCs system. A needle-like surface morphology of the active film was also discussed.

  17. Efficient solution-processed small molecule: Cadmium selenide quantum dot bulk heterojunction solar cells

    SciTech Connect (OSTI)

    Gupta, Vinay, E-mail: drvinaygupta@netscape.net [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India) [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India); Department of Physics, University of California, Santa Barbara, California 93106 (United States); Upreti, Tanvi; Chand, Suresh [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India)] [Physics of Energy Harvesting Division, Organic and Hybrid Solar Cell Group, CSIR-National Physical Laboratory, New Delhi-110012 (India)

    2013-12-16T23:59:59.000Z

    We report bulk heterojunction solar cells based on blends of solution-processed small molecule [7,7?-(4,4-bis(2-ethylhexyl)-4H-silolo[3,2-b:4,5-b?]dithiophene-2,6-diyl) bis(6-fluoro-4-(5?-hexyl-[2,2?-bithiophen]-5yl)benzo[c] [1,2,5] thiadiazole)] p-DTS(FBTTh{sub 2}){sub 2}: Cadmium Selenide (CdSe) (70:30, 60:40, 50:50, and 40:60) in the device configuration: Indium Tin Oxide /poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/p-DTS(FBTTh{sub 2}){sub 2}: CdSe/Ca/Al. The optimized ratio of p-DTS(FBTTh{sub 2}){sub 2}:CdSe::60:40 leads to a short circuit current density (J{sub sc})?=?5.45?mA/cm{sup 2}, open circuit voltage (V{sub oc})?=?0.727?V, and fill factor (FF)?=?51%, and a power conversion efficiency?=?2.02% at 100 mW/cm{sup 2} under AM1.5G illumination. The J{sub sc} and FF are sensitive to the ratio of p-DTS(FBTTh{sub 2}){sub 2}:CdSe, which is a crucial factor for the device performance.

  18. Spin signatures of photogenerated radical anions in polymer-[70]fullerene bulk-heterojunctions : high-frequency pulsed EPR spectroscopy.

    SciTech Connect (OSTI)

    Poluektov, O. G.; Filippone, S.; Martin, N.; Sperlich, A.; Deibel, C.; Dyakonov, V. (Chemical Sciences and Engineering Division); (Univ. Complutense de Madrid); (Univ. of Wurzburg)

    2010-04-14T23:59:59.000Z

    Charged polarons in thin films of polymer-fullerene composites are investigated by light-induced electron paramagnetic resonance (EPR) at 9.5 GHz (X-band) and 130 GHz (D-band). The materials studied were poly(3-hexylthiophene) (PHT), [6,6]-phenyl-C61-butyric acid methyl ester (C{sub 60}-PCBM), and two different soluble C{sub 70}-derivates: C{sub 70}-PCBM and diphenylmethano[70]fullerene oligoether (C{sub 70}-DPM-OE). The first experimental identification of the negative polaron localized on the C{sub 70}-cage in polymer-fullerene bulk heterojunctions has been obtained. When recorded at conventional X-band EPR, this signal is overlapping with the signal of the positive polaron, which does not allow for its direct experimental identification. Owing to the superior spectral resolution of the high frequency D-band EPR, we were able to separate light-induced signals from P{sup +} and P{sup -} in PHT-C{sub 70} bulk heterojunctions. Comparing signals from C{sub 70}-derivatives with different side-chains, we have obtained experimental proof that the polaron is localized on the cage of the C{sub 70} molecule.

  19. Spin Signatures of Photogenerated Radical Anions in Polymer?[70]Fullerene Bulk Heterojunctions: High Frequency Pulsed EPR Spectroscopy

    SciTech Connect (OSTI)

    Poluektov, Oleg G.; Pilippone, Salvatore; Martin, C. R.; Sperlich, Andreas; Deibel, Carsten; Dyakonov, Vladimir

    2010-01-01T23:59:59.000Z

    Charged polarons in thin films of polymer?fullerene composites are investigated by light-induced electron paramagnetic resonance (EPR) at 9.5 GHz (X-band) and 130 GHz (D-band). The materials studied were poly(3-hexylthiophene) (PHT), [6,6]-phenyl-C61-butyric acid methyl ester (C{sub 60}-PCBM), and two different soluble C{sub 70}-derivates: C{sub 70}-PCBM and diphenylmethano[70]fullerene oligoether (C{sub 70}-DPM-OE). The first experimental identification of the negative polaron localized on the C{sub 70}-cage in polymer?fullerene bulk heterojunctions has been obtained. When recorded at conventional X-band EPR, this signal is overlapping with the signal of the positive polaron, which does not allow for its direct experimental identification. Owing to the superior spectral resolution of the high frequency D-band EPR, we were able to separate light-induced signals from P{sup +} and P{sup ?} in PHT?C{sub 70} bulk heterojunctions. Comparing signals from C{sub 70}-derivatives with different side-chains, we have obtained experimental proof that the polaron is localized on the cage of the C{sub 70} molecule.

  20. Spin signatures of photogenerated radical anions in polymer-[70] fullerene bulk-heterojunctions : high-frequency pulsed EPR spectroscopy.

    SciTech Connect (OSTI)

    Poluektov, O. G.; Filippone, S.; Martin, N.; Sperlich, A.; Deibel, C.; Dyakonov, V. (Chemical Sciences and Engineering Division); (Univ. Complutense de Madrid); (Univ. of Wurzburg)

    2010-01-01T23:59:59.000Z

    Charged polarons in thin films of polymer-fullerene composites are investigated by light-induced electron paramagnetic resonance (EPR) at 9.5 GHz (X-band) and 130 GHz (D-band). The materials studied were poly(3-hexylthiophene) (PHT), [6,6]-phenyl-C61-butyric acid methyl ester (C{sub 60}-PCBM), and two different soluble C{sub 70}-derivates: C{sub 70}-PCBM and diphenylmethano[70]fullerene oligoether (C{sub 70}-DPM-OE). The first experimental identification of the negative polaron localized on the C{sub 70}-cage in polymer-fullerene bulk heterojunctions has been obtained. When recorded at conventional X-band EPR, this signal is overlapping with the signal of the positive polaron, which does not allow for its direct experimental identification. Owing to the superior spectral resolution of the high frequency D-band EPR, we were able to separate light-induced signals from P{sup +} and P{sup -} in PHT-C{sub 70} bulk heterojunctions. Comparing signals from C{sub 70}-derivatives with different side-chains, we have obtained experimental proof that the polaron is localized on the cage of the C{sub 70} molecule.

  1. Spin Signatures of Photogenerated Radical Anions in Polymer-[70]Fullerene Bulk Heterojunctions: High Frequency Pulsed EPR Spectroscopy

    E-Print Network [OSTI]

    Oleg G. Poluektov; Salvatore Filippone; Nazario Martin; Andreas Sperlich; Carsten Deibel; Vladimir Dyakonov

    2011-10-07T23:59:59.000Z

    Charged polarons in thin films of polymer-fullerene composites are investigated by light-induced electron paramagnetic resonance (EPR) at 9.5 GHz (X-band) and 130 GHz (D-band). The materials studied were poly(3-hexylthiophene) (PHT), [6,6]-phenyl-C61-butyric acid methyl ester (C60-PCBM), and two different soluble C70-derivates: C70-PCBM and diphenylmethano[70]fullerene oligoether (C70-DPM-OE). The first experimental identification of the negative polaron localized on the C70-cage in polymer-fullerene bulk heterojunctions has been obtained. When recorded at conventional X-band EPR, this signal is overlapping with the signal of the positive polaron, which does not allow for its direct experimental identification. Owing to the superior spectral resolution of the high frequency D-band EPR, we were able to separate light-induced signals from P+ and P- in PHT-C70 bulk heterojunctions. Comparing signals from C70-derivatives with different side-chains, we have obtained experimental proof that the polaron is localized on the cage of the C70 molecule.

  2. Spin Signatures of Photogenerated Radical Anions in Polymer-[70]Fullerene Bulk Heterojunctions: High Frequency Pulsed EPR Spectroscopy

    E-Print Network [OSTI]

    Poluektov, Oleg G; Martin, Nazario; Sperlich, Andreas; Deibel, Carsten; Dyakonov, Vladimir; 10.1021/jp1012347

    2011-01-01T23:59:59.000Z

    Charged polarons in thin films of polymer-fullerene composites are investigated by light-induced electron paramagnetic resonance (EPR) at 9.5 GHz (X-band) and 130 GHz (D-band). The materials studied were poly(3-hexylthiophene) (PHT), [6,6]-phenyl-C61-butyric acid methyl ester (C60-PCBM), and two different soluble C70-derivates: C70-PCBM and diphenylmethano[70]fullerene oligoether (C70-DPM-OE). The first experimental identification of the negative polaron localized on the C70-cage in polymer-fullerene bulk heterojunctions has been obtained. When recorded at conventional X-band EPR, this signal is overlapping with the signal of the positive polaron, which does not allow for its direct experimental identification. Owing to the superior spectral resolution of the high frequency D-band EPR, we were able to separate light-induced signals from P+ and P- in PHT-C70 bulk heterojunctions. Comparing signals from C70-derivatives with different side-chains, we have obtained experimental proof that the polaron is localized...

  3. Method to analyze the ability of bulk heterojunctions of organic and hybrid solar cells to dissociate photogenerated excitons and collect free carriers

    SciTech Connect (OSTI)

    Basta, M.; Dusza, M.; Palewicz, M.; Nawrot, U.; Granek, F., E-mail: filip.granek@eitplus.pl [Wroclaw Research Centre EIT, Stablowicka 147, 54-066 Wroclaw (Poland)

    2014-05-07T23:59:59.000Z

    We have developed a model to predict and analyze the photocurrent generation and resulting charge carrier Dissociation and Collection Efficiency (DCE) through reflectivity and quantum efficiency spectra. The DCE is regarded as a function of the morphology and exciton transport properties of the bulk heterojunction and is therefore a way to investigate the final properties of photoactive layer in a solar cell. Method proposed allows determination of the efficiency at which photogenerated excitons are dissociated in a working device with respect to the position in the cell at which the generation occurs. The method is tested on our results as well as on a number of results already present in the literature.

  4. Absence of Structural Impact of Noble Nanoparticles on P3HT: PCBM Blends for Plasmon Enhanced Bulk-Heterojunction Organic Solar Cells Probed by Synchrotron Grazing Incidence X-Ray Diffraction

    E-Print Network [OSTI]

    Samuele Lilliu; Mejd Alsari; Oier Bikondoa; J. Emyr Macdonald; Marcus S. Dahlem

    2014-10-18T23:59:59.000Z

    The incorporation of noble metal nanoparticles, displaying localized surface plasmon resonance, in the active area of donor-acceptor bulk-heterojunction organic photovoltaic devices is an industrially compatible light trapping strategy, able to guarantee better absorption of the incident photons and give an efficiency improvement between 12% and 38%. In the present work, we investigate the effect of Au and Ag nanoparticles blended with P3HT: PCBM on the P3HT crystallization dynamics by synchrotron grazing incidence X-ray diffraction. We conclude that the presence of (1) 80nm Au, (2) mix of 5nm, 50nm, 80nm Au, (3) 40nm Ag, and (4) 10nm, 40nm, 60nm Ag colloidal nanoparticles, at different concentrations below 0.3 wt% in P3HT: PCBM blends, does not affect the behaviour of the blends themselves.

  5. Center for Quantum Science and Engineering Weekly Seminar

    E-Print Network [OSTI]

    Wu, Yih-Min

    flexibility, and light-weight. The BHJ layer featuring a nanoscale interpenetrating network of electron donor, 14:30 ~ 15:30 TITLE Probe Nanoscale Morphologies of Bulk Heterojunction Polymer Solar Cell from Sinica PLACE Rm716, CCMS & New Physics Building, NTU Abstract Bulk heterojunction (BHJ) polymer solar

  6. Charge-Transfer Induced Magnetic Field Effects of Nano-Carbon Heterojunctions

    E-Print Network [OSTI]

    Qin, Wei; Gong, Maogang; Shastry, Tejas; Hersam, Mark C.; Ren, Shenqiang

    2014-08-22T23:59:59.000Z

    positive and negative polarons. Here, we demonstrate charge-transfer induced magnetic field effects in nano-carbon C60-SWCNT bulk heterojunctions at room temperature, where the mechanism of magnetic field effects is verified using excited state transition...

  7. Supersymmetry Across Nanoscale Heterojunction

    E-Print Network [OSTI]

    B. Bagchi; A. Ganguly; A. Sinha

    2010-02-13T23:59:59.000Z

    We argue that supersymmetric transformation could be applied across the heterojunction formed by joining of two mixed semiconductors. A general framework is described by specifying the structure of ladder operators at the junction for making quantitative estimation of physical quantities. For a particular heterojunction device, we show that an exponential grading inside a nanoscale doped layer is amenable to exact analytical treatment for a class of potentials distorted by the junctions through the solutions of transformed Morse-Type potentials.

  8. Heterojunction solar cell

    DOE Patents [OSTI]

    Olson, J.M.

    1994-08-30T23:59:59.000Z

    A high-efficiency single heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the emitter layer. 1 fig.

  9. Rational design of hybrid organic solar cells

    E-Print Network [OSTI]

    Lentz, Levi (Levi Carl)

    2014-01-01T23:59:59.000Z

    In this thesis, we will present a novel design for a nano-structured organic-inorganic hybrid photovoltaic material that will address current challenges in bulk heterojunction (BHJ) organic-based solar cell materials. ...

  10. www.afm-journal.de 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim 4295

    E-Print Network [OSTI]

    Schreiber, Frank

    bot- tleneck by creating an interpenetrating network of donor and acceptor materials, has proven heterojunctions (BHJ) from solution processed polymer-fullerene mixtures,[3,4] which reduces the exciton diffusion heterojunction cells. Bulk heterojunctions exhibit large-scale phase sepa- ration forming a bicontinuous network

  11. Nanocrystalline heterojunction materials

    DOE Patents [OSTI]

    Elder, Scott H.; Su, Yali; Gao, Yufei; Heald, Steve M.

    2003-07-15T23:59:59.000Z

    Mesoporous nanocrystalline titanium dioxide heterojunction materials are disclosed. In one disclosed embodiment, materials comprising a core of titanium dioxide and a shell of a molybdenum oxide exhibit a decrease in their photoadsorption energy as the size of the titanium dioxide core decreases.

  12. Nanocrystalline Heterojunction Materials

    DOE Patents [OSTI]

    Elder, Scott H. (Portland, OR); Su, Yali (Richland, WA); Gao, Yufei (Blue Bell, PA); Heald, Steve M. (Downers Grove, IL)

    2004-02-03T23:59:59.000Z

    Mesoporous nanocrystalline titanium dioxide heterojunction materials and methods of making the same are disclosed. In one disclosed embodiment, materials comprising a core of titanium dioxide and a shell of a molybdenum oxide exhibit a decrease in their photoadsorption energy as the size of the titanium dioxide core decreases.

  13. 2011 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimAdv. Mater. 2011, XX, 17 1 www.advmat.de

    E-Print Network [OSTI]

    Geohegan, David B.

    and formation of a nanoscale interpenetrating network of P3HT/PCBM via phase separation tuning is one Ridge, TN 37831, USA DOI: 10.1002/adma.201103361 Polymer bulk heterojunction (BHJ) solar cells have of the critical issues to achieve high-efficiency polymer BHJ solar cells with improved stability. In an effort

  14. Metal-Insulator Photocathode Heterojunction for Directed Electron...

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

    Insulator Photocathode Heterojunction for Directed Electron Emission. Metal-Insulator Photocathode Heterojunction for Directed Electron Emission. Abstract: New photocathode...

  15. Controlling Axial p-n Heterojunction Abruptness Through Catalyst...

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

    Axial p-n Heterojunction Abruptness Through Catalyst Alloying in Vapor-Liquid-Solid Grown Semiconductor Nanowires. Controlling Axial p-n Heterojunction Abruptness Through Catalyst...

  16. Small Molecule Solution-Processed Bulk Heterojunction Solar Cells

    E-Print Network [OSTI]

    Candea, George

    , Laboratory of Polymer and Composite Technology, Lausanne A large source of interest in organic photovoltaics to lateral structures with sizes of about 300 nm. The UV-Vis absorbance spectra of a SQ:PCBM blend film:PCBM blends with varying composition and indicate an eutectic system. This might provide a strategy to obtain

  17. The influence of molecular orientation on organic bulk heterojunction solar

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus TomAboutManusScienceThe Life ofSciencetheEnergyThe

  18. Mixed ternary heterojunction solar cell

    DOE Patents [OSTI]

    Chen, Wen S. (Seattle, WA); Stewart, John M. (Seattle, WA)

    1992-08-25T23:59:59.000Z

    A thin film heterojunction solar cell and a method of making it has a p-type layer of mixed ternary I-III-VI.sub.2 semiconductor material in contact with an n-type layer of mixed binary II-VI semiconductor material. The p-type semiconductor material includes a low resistivity copper-rich region adjacent the back metal contact of the cell and a composition gradient providing a minority carrier mirror that improves the photovoltaic performance of the cell. The p-type semiconductor material preferably is CuInGaSe.sub.2 or CuIn(SSe).sub.2.

  19. Sandia National Laboratories: Nanoscale Effects on Heterojunction...

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

    CoreShell Nanowires Nanoscale Effects on Heterojunction Electron Gases in GaNAlGaN CoreShell Nanowires Jeff Tsao participates in "Energy Efficiency and the Rebound Effect"...

  20. Polyaniline on crystalline silicon heterojunction solar cells Weining Wanga

    E-Print Network [OSTI]

    Schiff, Eric A.

    -Si have long been of fundamental interest, and amorphous silicon a-Si:H /c-Si heterojunctions are now is about the current limit achieved with a-Si:H/c-Si heterojunctions. The largest VOC we ob- tained was 0Polyaniline on crystalline silicon heterojunction solar cells Weining Wanga and E. A. Schiff

  1. Heterojunction solar cell with passivated emitter surface

    DOE Patents [OSTI]

    Olson, J.M.; Kurtz, S.R.

    1994-05-31T23:59:59.000Z

    A high-efficiency heterojunction solar cell is described wherein a thin emitter layer (preferably Ga[sub 0.52]In[sub 0.48]P) forms a heterojunction with a GaAs absorber layer. A passivating window layer of defined composition is disposed over the emitter layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the window layer. 1 fig.

  2. Heterojunction solar cell with passivated emitter surface

    DOE Patents [OSTI]

    Olson, Jerry M. (Lakewood, CO); Kurtz, Sarah R. (Golden, CO)

    1994-01-01T23:59:59.000Z

    A high-efficiency heterojunction solar cell wherein a thin emitter layer (preferably Ga.sub.0.52 In.sub.0.48 P) forms a heterojunction with a GaAs absorber layer. A passivating window layer of defined composition is disposed over the emitter layer. The conversion efficiency of the solar cell is at least 25.7%. The solar cell preferably includes a passivating layer between the substrate and the absorber layer. An anti-reflection coating is preferably disposed over the window layer.

  3. Rational Design of Zinc Phosphide Heterojunction Photovoltaics

    E-Print Network [OSTI]

    Winfree, Erik

    Rational Design of Zinc Phosphide Heterojunction Photovoltaics Thesis by Jeffrey Paul Bosco would meet me with the same energy and enthusiasm regarding the topic of zinc phosphide photovoltaics to the field of earth-abundant photovoltaics has been indispensable to my work. Greg also made a great mentor

  4. Scattering in a varying mass PT symmetric double heterojunction

    E-Print Network [OSTI]

    Anjana Sinha; R. Roychoudhury

    2013-06-10T23:59:59.000Z

    We observe that the reflection and transmission coefficients of a particle within a double, PT symmetric heterojunction with spatially varying mass, show interesting features, depending on the degree of non Hermiticity, although there is no spontaneous breakdown of PT symmetry. The potential profile in the intermediate layer is considered such that it has a non vanishing imaginary part near the heterojunctions. Exact analytical solutions for the wave function are obtained, and the reflection and transmission coefficients are plotted as a function of energy, for both left as well as right incidence. As expected, the spatial dependence on mass changes the nature of the scattering solutions within the heterojunctions, and the space-time (PT) symmetry is responsible for the left-right asymmetry in the reflection and transmission coefficients. However, the non vanishing imaginary component of the potential near the heterojunctions gives new and interesting results.

  5. Rotary bulk solids divider

    DOE Patents [OSTI]

    Maronde, Carl P. (McMurray, PA); Killmeyer, Jr., Richard P. (Pittsburgh, PA)

    1992-01-01T23:59:59.000Z

    An apparatus for the disbursement of a bulk solid sample comprising, a gravity hopper having a top open end and a bottom discharge end, a feeder positioned beneath the gravity hopper so as to receive a bulk solid sample flowing from the bottom discharge end, and a conveyor receiving the bulk solid sample from the feeder and rotating on an axis that allows the bulk solid sample to disperse the sample to a collection station.

  6. Amorphous silicon/crystalline silicon heterojunctions: The future of high-efficiency silicon solar cells

    E-Print Network [OSTI]

    Firestone, Jeremy

    ;5 Record efficiencies #12;6 Diffused-junction solar cells Diffused-junction solar cell Chemical passivation to ~650 mV #12;7 Silicon heterojunction solar cells a-Si:H provides excellent passivation of c-Si surface Heterojunction solar cell Chemical passivation Chemical passivation #12;8 Voc and silicon heterojunction solar

  7. Bulk Heterojunction Organic Solar Cells utilizing a Benzothiadiazole-based Oligomer

    E-Print Network [OSTI]

    Collins, Gary S.

    Advantages over silicon solar cells · Roll-to-roll manufacturing lowers costs through a faster rate cells, which have issues of their own, will remain the dominant solar energy provider and the world to find a viable option to alleviate global energy concerns. One proposed solution, the organic solar cell

  8. Annealing dependent performance of organic bulk-heterojunction solar cells: A theoretical perspective

    E-Print Network [OSTI]

    Alam, Muhammad A.

    solar cell Process conditions a b s t r a c t Organic photovoltaic (OPV) technology promises efficiency/reliability, a systematic theoretical approach is required to optimize the underlying device for the optimization of process conditions, which might eventually lead to higher efficiency/reliability of the organic

  9. Electronic structure and transition energies in polymer-fullerene bulk heterojunctions

    E-Print Network [OSTI]

    2014-01-01T23:59:59.000Z

    Electronic Structure and Transition Energies in Polymer?the HOMO and LUMO energy levels and transition energies haveand charge-transfer transition energies. The interface band

  10. Sodium bromide electron-extraction layers for polymer bulk-heterojunction solar cells

    SciTech Connect (OSTI)

    Gao, Zhi; Qu, Bo, E-mail: bqu@pku.edu.cn; Xiao, Lixin; Chen, Zhijian [State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China) [State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); New Display Device and System Integration Collaborative Innovation Center of the West Coast of the Taiwan Strait, Fuzhou 350002 (China); Zhang, Lipei [State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China)] [State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Gong, Qihuang [State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China) [State Key Laboratory for Artificial Microstructures and Mesoscopic Physics, Department of Physics, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing 100871 (China)

    2014-03-10T23:59:59.000Z

    Inexpensive and non-toxic sodium bromide (NaBr) was introduced into polymer solar cells (PSCs) as the cathode buffer layer (CBL) and the electron extraction characteristics of the NaBr CBL were investigated in detail. The PSCs based on NaBr CBL with different thicknesses (i.e., 0?nm, 0.5?nm, 1?nm, and 1.5?nm) were prepared and studied. The optimal thickness of NaBr was 1?nm according to the photovoltaic data of PSCs. The open-circuit voltage (V{sub oc}), short-circuit current density (J{sub sc}), fill factor (FF), and power conversion efficiency (PCE) of the PSC with 1?nm NaBr were evaluated to be 0.58?V, 7.36?mA/cm{sup 2}, 0.63, and 2.70%, respectively, which were comparable to those of the reference device with the commonly used LiF. The optimized photovoltaic performance of PSC with 1?nm NaBr was ascribed to the improved electron transport and extraction capability of 1?nm NaBr in PSCs. In addition, the NaBr CBL could prevent the diffusion of oxygen and water vapor into the active layer and prolong the lifetime of the devices to some extent. Therefore, NaBr layer could be considered as a promising non-toxic CBL for PSCs in future.

  11. Charge density dependent nongeminate recombination in organic bulk heterojunction solar cells

    E-Print Network [OSTI]

    D. Rauh; C. Deibel; V. Dyakonov

    2012-03-27T23:59:59.000Z

    Apparent recombination orders exceeding the value of two expected for bimolecular recombination have been reported for organic solar cells in various publications. Two prominent explanations are bimolecular losses with a carrier concentration dependent prefactor due to a trapping limited mobility, and protection of trapped charge carriers from recombination by a donor--acceptor phase separation until reemission from these deep states. In order to clarify which mechanism is dominant we performed temperature and illumination dependent charge extraction measurements under open circuit as well as short circuit conditions at poly(3-hexylthiophene-2,5-diyl):[6,6]-phenyl-C$_{61}$butyric acid methyl ester (P3HT:PC$_{61}$BM) and PTB7:PC$_{71}$BM (Poly[[4,8-bis[(2-ethylhexyl)oxy]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl

  12. SciTech Connect: Material Profile Influences in Bulk-Heterojunctions

    Office of Scientific and Technical Information (OSTI)

    Sustainability Program, Award No. 0933435. This work benefited from the use of the Lujan Neutron Scattering Center at Los Alamos Neutron Science Center funded by the DOE Office of...

  13. Tuning of defects in ZnO nanorod arrays used in bulk heterojunction solar cells

    E-Print Network [OSTI]

    Iza, Diana C; Muńoz-Rojas, David; Jia, Quanxi; Swartzentruber, Brian; MacManus-Driscoll, Judith L

    2012-11-27T23:59:59.000Z

    by radio frequency magnetron sputtering. J Mater Res 2005, 20:1574–1579. 55. Cui J: Zinc oxide nanowires. Mater Charact 2012, 64:43–52. 56. Fan Z, Wang D, Chang P-C, Tseng W-Y, Lu JG: ZnO nanowire field-effect transistor and oxygen sensing property. Appl... to 130 nm in diameter and ca. 800 nm in length. Figure 1d,e shows cross-sectional images of the solar cell devices produced herein, which will be discussed later. Results and discussion Firstly, we present the PL data on our samples together with IR...

  14. Interfacial Engineering for Highly Efficient-Conjugated Polymer-Based Bulk Heterojunction Photovoltaic Devices

    SciTech Connect (OSTI)

    Alex Jen; David Ginger; Christine Luscombe; Hong Ma

    2012-04-02T23:59:59.000Z

    The aim of our proposal is to apply interface engineering approach to improve charge extraction, guide active layer morphology, improve materials compatibility, and ultimately allow the fabrication of high efficiency tandem cells. Specifically, we aim at developing: i. Interfacial engineering using small molecule self-assembled monolayers ii. Nanostructure engineering in OPVs using polymer brushes iii. Development of efficient light harvesting and high mobility materials for OPVs iv. Physical characterization of the nanostructured systems using electrostatic force microscopy, and conducting atomic force microscopy v. All-solution processed organic-based tandem cells using interfacial engineering to optimize the recombination layer currents vi. Theoretical modeling of charge transport in the active semiconducting layer The material development effort is guided by advanced computer modeling and surface/ interface engineering tools to allow us to obtain better understanding of the effect of electrode modifications on OPV performance for the investigation of more elaborate device structures. The materials and devices developed within this program represent a major conceptual advancement using an integrated approach combining rational molecular design, material, interface, process, and device engineering to achieve solar cells with high efficiency, stability, and the potential to be used for large-area roll-to-roll printing. This may create significant impact in lowering manufacturing cost of polymer solar cells for promoting clean renewable energy use and preventing the side effects from using fossil fuels to impact environment.

  15. Enhanced performance of polymer:fullerene bulk heterojunction solar cells upon graphene addition

    SciTech Connect (OSTI)

    Robaeys, Pieter, E-mail: pieter.robaeys@uhasselt.be; Dierckx, Wouter; Dexters, Wim; Spoltore, Donato; Drijkoningen, Jeroen [Institute for Materials Research (IMO), Hasselt University (Belgium); Bonaccorso, Francesco [Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge (United Kingdom); Istituto Italiano di Tecnologia, Graphene Labs, Via Morego 30, 16163 Genova (Italy); Bourgeois, Emilie; D'Haen, Jan; Haenen, Ken; Manca, Jean V.; Nesladek, Milos [Institute for Materials Research (IMO), Hasselt University (Belgium); IMOMEC, IMEC vzw (Belgium); Liesenborgs, Jori; Van Reeth, Frank [Expertise centre for Digital Media (EDM), Hasselt University (Belgium); Lombardo, Antonio; Ferrari, Andrea C. [Cambridge Graphene Centre, University of Cambridge, 9 JJ Thomson Avenue, Cambridge (United Kingdom)

    2014-08-25T23:59:59.000Z

    Graphene has potential for applications in solar cells. We show that the short circuit current density of P3HT (Poly(3-hexylthiophene-2,5-diyl):PCBM((6,6)-Phenyl C61 butyric acid methyl ester) solar cells is enhanced by 10% upon the addition of graphene, with a 15% increase in the photon to electric conversion efficiency. We discuss the performance enhancement by studying the crystallization of P3HT, as well as the electrical transport properties. We show that graphene improves the balance between electron and hole mobilities with respect to a standard P3HT:PCBM solar cell.

  16. Solar Cells: Spin-Cast Bulk Heterojunction Solar Cells: A Dynamical

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassiveSubmittedStatus Tom Fletcher,Future | Department of

  17. Copper oxide/N-silicon heterojunction photovoltaic device

    DOE Patents [OSTI]

    Feng, Tom (Morris Plains, NJ); Ghosh, Amal K. (New Providence, NJ)

    1982-01-01T23:59:59.000Z

    A photovoltaic device having characteristics of a high efficiency solar cell comprising a Cu.sub.x O/n-Si heterojunction. The Cu.sub.x O layer is formed by heating a deposited copper layer in an oxygen containing ambient.

  18. Large area bulk superconductors

    DOE Patents [OSTI]

    Miller, Dean J. (Darien, IL); Field, Michael B. (Jersey City, NJ)

    2002-01-01T23:59:59.000Z

    A bulk superconductor having a thickness of not less than about 100 microns is carried by a polycrystalline textured substrate having misorientation angles at the surface thereof not greater than about 15.degree.; the bulk superconductor may have a thickness of not less than about 100 microns and a surface area of not less than about 50 cm.sup.2. The textured substrate may have a thickness not less than about 10 microns and misorientation angles at the surface thereof not greater than about 15.degree.. Also disclosed is a process of manufacturing the bulk superconductor and the polycrystalline biaxially textured substrate material.

  19. Core/Shell heterojunction nanowire solar cell fabricated by lithographically patterned nanowire electrodeposition method

    E-Print Network [OSTI]

    Ghosh, Somnath

    2012-01-01T23:59:59.000Z

    Menke. Gold Core–Semiconductor Shell Nanowires Prepared bycarrier concentration in CIS shell at different depositionMerced Dissertation: Core/Shell Heterojunction Nanowires

  20. Junction Transport in Epitaxial Film Silicon Heterojunction Solar Cells: Preprint

    SciTech Connect (OSTI)

    Young, D. L.; Li, J. V.; Teplin, C. W.; Stradins, P.; Branz, H. M.

    2011-07-01T23:59:59.000Z

    We report our progress toward low-temperature HWCVD epitaxial film silicon solar cells on inexpensive seed layers, with a focus on the junction transport physics exhibited by our devices. Heterojunctions of i/p hydrogenated amorphous Si (a-Si) on our n-type epitaxial crystal Si on n++ Si wafers show space-charge-region recombination, tunneling or diffusive transport depending on both epitaxial Si quality and the applied forward voltage.

  1. Highmobility inverted selectively doped heterojunctions Hadas Shtrikman, M. Heiblum, K. Seo, D. E. Galbi, and L. Osterling

    E-Print Network [OSTI]

    Heiblum, Mordehai "Moty"

    Highmobility inverted selectively doped heterojunctions Hadas Shtrikman, M. Heiblum, K. Seo, D. E in inverted GaAsAlGaAs heterojunctions Appl. Phys. Lett. 52, 1268 (1988); 10.1063/1.99176 High mobility: 132.76.50.6 On: Thu, 10 Apr 2014 16:05:40 #12;High-mobility inverted selectively doped heterojunctions

  2. Analysis of a-Si:H/TCO contact resistance for the Si heterojunction back-contact solar cell

    E-Print Network [OSTI]

    Park, Byungwoo

    Analysis of a-Si:H/TCO contact resistance for the Si heterojunction back-contact solar cell Seung- circuit voltage (Voc) and the conversion efficiency of the Si solar cell. Recently, a-Si:H heterojunction (heterojunction with intrinsic thin layer) cell [1] even with practical-sized Czochralski-grown (CZ) wafer. The a-Si:H

  3. Bulk Hydrogen Strategic Directions for

    E-Print Network [OSTI]

    Bulk Hydrogen Storage Strategic Directions for Hydrogen Delivery Workshop May 7-8, 2003 Crystal City, Virginia #12;Breakout Session - Bulk Hydrogen Storage Main Themes/Caveats Bulk Storage = Anything storage is an economic solution to address supply/demand imbalance #12;Breakout Session - Bulk Hydrogen

  4. CNT-SI HETEROJUNCTION SOLAR CELLS WITH STRUCTURE-CONTROLLED SINGLE-WALL CARBON NANOTUBE FILMS

    E-Print Network [OSTI]

    Maruyama, Shigeo

    CNT-SI HETEROJUNCTION SOLAR CELLS WITH STRUCTURE- CONTROLLED SINGLE-WALL CARBON NANOTUBE FILMS. The heterojunction solar cell was fabricated by dry depositing the SWNT film to the 3 mm by 3 mm n-type silicon solar cells. We proposed a water-vapor treatment to build up SWNTs to a self-assembled micro- honeycomb

  5. Bulk Power Transmission Study

    E-Print Network [OSTI]

    John, T.

    BULK POWER TRANSMISSION STUDY TOMMY JOH~ P. E. Manager of Resource Recovery Waste Management of North America, Inc. Houston, Texas Texans now have a choice. We can become more efficient and maintain our standard of living, or we can... continue business as usual and watch our standard of living erode from competition from other regions. In the past, except for improving reliability, there was no need for a strong transmission system. When Texas generation was primarily gas fueled...

  6. Band offsets at heterojunctions and the charge neutrality condition

    E-Print Network [OSTI]

    Taferner, Waltraud Teresa

    1990-01-01T23:59:59.000Z

    . Transitivity test for several (110) heterojunctions assuming that Ek & EB & E+ g g g Heterojunction Sequence A/C Ge/A1As Ge/A1Sb Ge/Gaks Ge/Gap Ge/InP Ge/Si Si/A1As Si/GaAs Si/GaP Si/InAs Si/InSb Gaks/InAs GaSb/InAs InP/InAs InP /Alks A/8 Ge.../GaAs Ge/InP Ge/Si Ge/Si Ge/InP Ge/Si Ge/GaAs Ge/Si Ge/Si Ge/GaSb Si/Gaks Si/InP Si/InP Si/GaAs Si/Ge Si/GaSb Si/Ge GaAs/InP Gaks/Si Gaks/Ge GaSb/Ge InP/Si InP/Ge InP/GaAs B/C GaAs/A1As InP/A1As Si/A1As Si/klSb InP/GaAs Si...

  7. Creating bulk nanocrystalline metal.

    SciTech Connect (OSTI)

    Fredenburg, D. Anthony (Georgia Institute of Technology, Atlanta, GA); Saldana, Christopher J. (Purdue University, West Lafayette, IN); Gill, David D.; Hall, Aaron Christopher; Roemer, Timothy John (Ktech Corporation, Albuquerque, NM); Vogler, Tracy John; Yang, Pin

    2008-10-01T23:59:59.000Z

    Nanocrystalline and nanostructured materials offer unique microstructure-dependent properties that are superior to coarse-grained materials. These materials have been shown to have very high hardness, strength, and wear resistance. However, most current methods of producing nanostructured materials in weapons-relevant materials create powdered metal that must be consolidated into bulk form to be useful. Conventional consolidation methods are not appropriate due to the need to maintain the nanocrystalline structure. This research investigated new ways of creating nanocrystalline material, new methods of consolidating nanocrystalline material, and an analysis of these different methods of creation and consolidation to evaluate their applicability to mesoscale weapons applications where part features are often under 100 {micro}m wide and the material's microstructure must be very small to give homogeneous properties across the feature.

  8. Influence of oriented topological defects on the mechanical properties of carbon nanotube heterojunctions

    SciTech Connect (OSTI)

    Lee, We-Jay [National Center for High-Performance Computing; Chang, Jee-Gong [National Center for High-Performance Computing; Yang, An-Cheng [National Center for High-Performance Computing; Wang, Yeng-Tseng [National Center for High-Performance Computing; Su, Wan-Sheng [National Center for High-Performance Computing; Wang, Cai-Zhuang [Ames Laboratory; Ho, Kai-Ming [Ames Laboratory

    2013-10-10T23:59:59.000Z

    The mechanical properties of finite-length (5,0)/(8,0) single-walled carbon nanotube (SWCNT) heterojunctions with manipulated topological defects are investigated using molecular dynamics simulation calculations. The results show that the mechanical properties and deformation behavior of SWCNT heterojunctions are mainly affected not only by the diameter of the thinner segment of the SWCNT heterojunction but also by the orientation of the heptagon-heptagon (7-7) pair in the junction region. Moreover, the orientation of the 7-7 pair strongly affects those properties in the compression loading than those in tensile loading. Finally, it is found that the location of buckling deformation in the heterojunctions is dependent on the orientation of the 7-7 pair in the compression.

  9. High efficiency silicon nanohole/organic heterojunction hybrid solar cell

    SciTech Connect (OSTI)

    Hong, Lei [Novitas, Nanoelectronics Centre of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Singapore Institute of Manufacturing Technology, A-STAR (Agency for Science, Technology and Research), 71 Nanyang Drive, Singapore 638075 (Singapore); Wang, Xincai; Zheng, Hongyu [Singapore Institute of Manufacturing Technology, A-STAR (Agency for Science, Technology and Research), 71 Nanyang Drive, Singapore 638075 (Singapore); He, Lining; Wang, Hao; Rusli, E-mail: yu.hy@sustc.edu.cn, E-mail: erusli@ntu.edu.sg [Novitas, Nanoelectronics Centre of Excellence, School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798 (Singapore); Yu, Hongyu, E-mail: yu.hy@sustc.edu.cn, E-mail: erusli@ntu.edu.sg [South University of Science and Technology of China, Shenzhen (China)

    2014-02-03T23:59:59.000Z

    High efficiency hybrid solar cells are fabricated based on silicon with a nanohole (SiNH) structure and poly (3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS). The SiNH structure is fabricated using electroless chemical etching with silver catalyst, and the heterojunction is formed by spin coating of PEDOT on the SiNH. The hybrid cells are optimized by varying the hole depth, and a maximum power conversion efficiency of 8.3% is achieved with a hole depth of 1??m. The SiNH hybrid solar cell exhibits a strong antireflection and light trapping property attributed to the sub-wavelength dimension of the SiNH structure.

  10. p-Type semiconducting nickel oxide as an efficiency-enhancing anodal interfacial layer in bulk heterojunction solar cells

    DOE Patents [OSTI]

    Irwin, Michael D; Buchholz, Donald B; Marks, Tobin J; Chang, Robert P. H.

    2014-11-25T23:59:59.000Z

    The present invention, in one aspect, relates to a solar cell. In one embodiment, the solar cell includes an anode, a p-type semiconductor layer formed on the anode, and an active organic layer formed on the p-type semiconductor layer, where the active organic layer has an electron-donating organic material and an electron-accepting organic material.

  11. Enhancement of short-circuit current density in polymer bulk heterojunction solar cells comprising plasmonic silver nanowires

    SciTech Connect (OSTI)

    Yang, Yuzhao; Lin, Xiaofeng; Ou, Jiemei; Chen, Xudong, E-mail: cescxd@mail.sysu.edu.cn, E-mail: stszx@mail.sysu.edu.cn, E-mail: chenyj69@mail.sysu.edu.cn [Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education of China, Sun Yat-sen University, Guangzhou 510275 (China); Qing, Jian; Zhong, Zhenfeng; Zhou, Xiang, E-mail: cescxd@mail.sysu.edu.cn, E-mail: stszx@mail.sysu.edu.cn, E-mail: chenyj69@mail.sysu.edu.cn; Chen, Yujie, E-mail: cescxd@mail.sysu.edu.cn, E-mail: stszx@mail.sysu.edu.cn, E-mail: chenyj69@mail.sysu.edu.cn [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Hu, Chenglong [Key Laboratory of Optoelectronic Chemical Materials and Devices of Ministry of Education, Jianghan University, Wuhan 430056 (China)

    2014-03-24T23:59:59.000Z

    We demonstrate that the influence of plasmonic effects based on silver nanowires (Ag NWs) on the characteristics of polymer solar cells (PSCs). The solution-processed Ag NWs are situated at the interface of anode buffer layer and active layer, which could enhance the performance especially the photocurrent of PSCs by scattering, localized surface plasmon resonance, and surface plasmon polaritons. Plasmonic effects are confirmed by the enhancement of extinction spectra, external quantum efficiency, and steady state photoluminescence. Consequently, the short-circuit current density (J{sub sc}) and power conversion efficiency enhance about 24% and 18%, respectively, under AM1.5 illumination when Ag NWs plasmonic nanostructure incorporated into PSCs.

  12. Band alignment engineering in organized rrP3HT/C60 bulk heterojunction Arnaud Maillard

    E-Print Network [OSTI]

    Rochefort, Alain

    photovoltaic devices with large-scale and low-cost print- ing techniques associated with the facility to process poly- mer could overcome the cost limitation of traditional inorganic photovoltaic cells [2 multiple technologies, including photovoltaic cells, with the aim of replacing more tradi- tional energy

  13. Controlled Growth of Single-Walled Carbon Nanotubes and Application to CNT-Si Heterojunction Solar Cells

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Controlled Growth of Single-Walled Carbon Nanotubes and Application to CNT-Si Heterojunction Solar assembly of SWNTs for SWNT-Si heterojunction solar cells will be discussed. We found the reversible to be encapsulated diatomic N2 molecules interior of SWNTs with the content of 1 at %. We address that the nitrogen

  14. Self-Assembled Micro-Honeycomb Network of Single-Walled Carbon Nanotubes for Heterojunction Solar Cells

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Self-Assembled Micro-Honeycomb Network of Single-Walled Carbon Nanotubes for Heterojunction Solar@photon.t.u-tokyo.ac.jp Keywords: Self-assembly, micro-honeycomb network, single-walled carbon nanotubes, heterojunction solar cell-assembled micro-honeycomb network (-HN) of SWNTs obtained by water or ethanol vapor treatment of as

  15. Light Trapping for High Efficiency Heterojunction Crystalline Si Solar Cells: Preprint

    SciTech Connect (OSTI)

    Wang, Q.; Xu, Y.; Iwaniczko, E.; Page, M.

    2011-04-01T23:59:59.000Z

    Light trapping plays an important role to achieve high short circuit current density (Jsc) and high efficiency for amorphous/crystalline Si heterojunction solar cells. Si heterojunction uses hydrogenated amorphous Si for emitter and back contact. This structure of solar cell posses highest open circuit voltage of 0.747 V at one sun for c-Si based solar cells. It also suggests that over 25% record-high efficiency is possible with further improvement of Jsc. Light trapping has two important tasks. The first one is to reduce the surface reflectance of light to zero for the solar spectrum that Si has a response. The second one is to increase the effective absorption length to capture all the photon. For Si heterojunction solar cell, surface texturing, anti-reflectance indium tin oxides (ITO) layer at the front and back are the key area to improve the light trapping.

  16. Efficient Crystalline Si Solar Cell with Amorphous/Crystalline Silicon Heterojunction as Back Contact: Preprint

    SciTech Connect (OSTI)

    Nemeth, B.; Wang, Q.; Shan, W.

    2012-06-01T23:59:59.000Z

    We study an amorphous/crystalline silicon heterojunction (Si HJ) as a back contact in industrial standard p-type five-inch pseudo-square wafer to replace Al back surface field (BSF) contact. The best efficiency in this study is over 17% with open-circuit (Voc) of 0.623 V, which is very similar to the control cell with Al BSF. We found that Voc has not been improved with the heterojunction structure in the back. The typical minority carrier lifetime of these wafers is on the order of 10 us. We also found that the doping levels of p-layer affect the FF due to conductivity and band gap shifting, and an optimized layer is identified. We conclude that an amorphous/crystalline silicon heterojunction can be a very promising structure to replace Al BSF back contact.

  17. Thermoelectric Bulk Materials from the Explosive Consolidation...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Bulk Materials from the Explosive Consolidation of Nanopowders Thermoelectric Bulk Materials from the Explosive Consolidation of Nanopowders Describes technique of explosively...

  18. Nanostructured High Temperature Bulk Thermoelectric Energy Conversion...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High Temperature Bulk Thermoelectric Energy Conversion for Efficient Waste Heat Recovery Nanostructured High Temperature Bulk Thermoelectric Energy Conversion for Efficient Waste...

  19. Scattering states of a particle, with position-dependent mass, in a double heterojunction

    E-Print Network [OSTI]

    Anjana Sinha

    2011-11-17T23:59:59.000Z

    In this work we obtain the exact analytical scattering solutions of a particle (electron or hole) in a semiconductor double heterojunction - potential well / barrier - where the effective mass of the particle varies with position inside the heterojunctions. It is observed that the spatial dependence of mass within the well / barrier introduces a nonlinear component in the plane wave solutions of the continuum states. Additionally, the transmission coefficient is found to increase with increasing energy, finally approaching unity, whereas the reflection coefficient follows the reverse trend and goes to zero.

  20. Depleted-heterojunction colloidal quantum dot photovoltaics employing low-cost electrical contacts

    E-Print Network [OSTI]

    Department of Materials Science and Engineering, 184 College Street, Toronto, Ontario M5S 3E4, Canada 3 of depleted-heterojunction colloidal quantum dot solar cells, we describe herein a strategy that replaces. © 2010 American Institute of Physics. doi:10.1063/1.3463037 Solar energy harvesting requires

  1. EARTH ABUNDANT MATERIALS FOR HIGH EFFICIENCY HETEROJUNCTION THIN FILM SOLAR CELLS

    E-Print Network [OSTI]

    Ceder, Gerbrand

    EARTH ABUNDANT MATERIALS FOR HIGH EFFICIENCY HETEROJUNCTION THIN FILM SOLAR CELLS Yun Seog Lee 1; * Corresponding author: buonassisi@mit.edu; ABSTRACT We investigate earth abundant materials for thin- film solar cuprous oxide (Cu2O) as a prototype candidate for investigation as an absorber layer in thin film solar

  2. Atomic Structure of Interface States in Silicon Heterojunction Solar Cells B. M. George,1

    E-Print Network [OSTI]

    Schmidt, Wolf Gero

    silicon (a-Si:H=c-Si) heterojunction solar cells. We find that (i) the interface exhibits microscopic identify the microscopic origin of the conduction band tail state in the a-Si:H layer, and (iv) present-efficiency solar cells, is formed at the a-Si: H=c-Si interface [8]. Here, similar to other crystalline- amorphous

  3. Photoconductive Decay Lifetime and Suns-Voc Diagnostics of Efficient Heterojunction Solar Cells: Preprint

    SciTech Connect (OSTI)

    Page, M. R.; Iwaniczko, E.; Xu, Y.; Roybal L.; Bauer, R.; Yan, H.-C.; Wang, Q.; Meier, D. L.

    2008-05-01T23:59:59.000Z

    We report results of minority carrier lifetime measurements for double-sided p-type Si heterojunction devices and compare Suns-Voc results to Light I-V measurements on 1 cm2 solar cell devices measured on an AM1.5 calibrated XT-10 solar simulator.

  4. InGaAsN/GaAs heterojunction for multi-junction solar cells

    DOE Patents [OSTI]

    Kurtz, Steven R. (Albuquerque, NM); Allerman, Andrew A. (Albuquerque, NM); Klem, John F. (Albuquerque, NM); Jones, Eric D. (Edgewood, NM)

    2001-01-01T23:59:59.000Z

    An InGaAsN/GaAs semiconductor p-n heterojunction is disclosed for use in forming a 0.95-1.2 eV bandgap photodetector with application for use in high-efficiency multi-junction solar cells. The InGaAsN/GaAs p-n heterojunction is formed by epitaxially growing on a gallium arsenide (GaAs) or germanium (Ge) substrate an n-type indium gallium arsenide nitride (InGaAsN) layer having a semiconductor alloy composition In.sub.x Ga.sub.1-x As.sub.1-y N.sub.y with 0heterojunction can be epitaxially grown by either molecular beam epitaxy (MBE) or metalorganic chemical vapor deposition (MOCVD). The InGaAsN/GaAs p-n heterojunction provides a high open-circuit voltage of up to 0.62 volts and an internal quantum efficiency of >70%.

  5. PUBLISHED ONLINE: 15 MAY 2011 | DOI: 10.1038/NMAT3026 Tailoring organic heterojunction interfaces in

    E-Print Network [OSTI]

    Weeks, Eric R.

    . However, in most cases, heat and pressure are applied to transfer the films, which can also induce be connected by a simple film-transfer method without disturbing their flat surfaces. Each film can further moments that were selected to align the energy levels at the heterojunction. The open-circuit voltages

  6. CBC Reduction in InP Heterojunction Bipolar Transistor with Selectively Implanted Collector Pedestal

    E-Print Network [OSTI]

    Rodwell, Mark J. W.

    CBC Reduction in InP Heterojunction Bipolar Transistor with Selectively Implanted Collector-3812 Fax: (805) 893-8714 Email: yingda@ece.ucsb.edu The base-collector junction capacitance (Cbc) is a key with a collector pedestal under the HBT's intrinsic region by using selective ion implantation and MBE regrowth

  7. Micro-Honeycomb Network Structure of Single-Walled Carbon Nanotubes for Heterojunction Solar Cell

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Micro-Honeycomb Network Structure of Single-Walled Carbon Nanotubes for Heterojunction Solar Cell, The University of Tokyo, Tokyo 113-8656, Japan We propose a self-organized micro-honeycomb network structure in Fig. 2. The micro-honeycomb SWNTs network film was placed on top of the substrate which has a 3 mm Ă? 3

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

    SciTech Connect (OSTI)

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

    2013-11-14T23:59:59.000Z

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

  9. Integrated optical and electrical modeling of plasmon-enhanced thin film photovoltaics: A case-study on organic devices

    SciTech Connect (OSTI)

    Rourke, Devin [Department of Physics, University of Colorado, Boulder, Colorado 80309-0390 (United States); Ahn, Sungmo [Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado 80309-0425 (United States); Nardes, Alexandre M.; Lagemaat, Jao van de; Kopidakis, Nikos [National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, Colorado 80401 (United States); Park, Wounjhang, E-mail: won.park@colorado.edu [Department of Electrical, Computer, and Energy Engineering, University of Colorado, Boulder, Colorado 80309-0425 (United States); Materials Science and Engineering Program, University of Colorado, Boulder, Colorado 80303 (United States)

    2014-09-21T23:59:59.000Z

    The nanoscale light control for absorption enhancement of organic photovoltaic (OPV) devices inevitably produces strongly non-uniform optical fields. These non-uniformities due to the localized optical modes are a primary route toward absorption enhancement in OPV devices. Therefore, a rigorous modeling tool taking into account the spatial distribution of optical field and carrier generation is necessary. Presented here is a comprehensive numerical model to describe the coupled optical and electrical behavior of plasmon-enhanced polymer:fullerene bulk heterojunction (BHJ) solar cells. In this model, a position-dependent electron-hole pair generation rate that could become highly non-uniform due to photonic nanostructures is directly calculated from the optical simulations. By considering the absorption and plasmonic properties of nanophotonic gratings included in two different popular device architectures, and applying the Poisson, current continuity, and drift/diffusion equations, the model predicts quantum efficiency, short-circuit current density, and desired carrier mobility ratios for bulk heterojunction devices incorporating nanostructures for light management. In particular, the model predicts a significant degradation of device performance when the carrier species with lower mobility are generated far from the collecting electrode. Consequently, an inverted device architecture is preferred for materials with low hole mobility. This is especially true for devices that include plasmonic nanostructures. Additionally, due to the incorporation of a plasmonic nanostructure, we use simulations to theoretically predict absorption band broadening of a BHJ into energies below the band gap, resulting in a 4.8% increase in generated photocurrent.

  10. Silicon heterojunction solar cell with passivated hole selective MoO{sub x} contact

    SciTech Connect (OSTI)

    Battaglia, Corsin; Yin, Xingtian; Zheng, Maxwell; Javey, Ali, E-mail: ajavey@eecs.berkeley.edu [Electrical Engineering and Computer Sciences Department, University of California, Berkeley, California 94720 (United States); Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States); Martín de Nicolás, Silvia; De Wolf, Stefaan; Ballif, Christophe [Photovoltaics and Thin Film Electronics Laboratory, Ecole Polytechnique Fédérale de Lausanne, 2000 Neuchâtel (Switzerland)

    2014-03-17T23:59:59.000Z

    We explore substoichiometric molybdenum trioxide (MoO{sub x}, x?heterojunction cell. Our results emphasize the strong potential for oxides as carrier selective heterojunction partners to inorganic semiconductors.

  11. Heterojunction thin films based on multifunctional metal oxides for photovoltaic application

    SciTech Connect (OSTI)

    Prabhu, M.; Soundararajan, N.; Ramachandran, K. [School of Physics, Madurai Kamaraj University, Madurai - 625021 (India); Marikkannan, M.; Mayandi, J. [School of Chemistry, Madurai Kamaraj University, Madurai - 625021 (India)

    2014-04-24T23:59:59.000Z

    Metal oxides based multifunctional heterojunction thin films of ZnO/SnO{sub 2} and ZnO/SnO{sub 2}/CuO QDs were prepared by spin-coating technique. The crystallographic properties and the surface morphologies of the films were studied by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The optical absorption studies revealed that the film thickness has considerable effect on the band gap values and is found to be in the range of 3.73–3.48 eV. The photoluminescence spectra showed several weak visible emission peaks related to the deep level defects (450-575 nm). Finally, the current density-voltage (J-V) characteristic of ZnO/SnO{sub 2}/CuO QDs (ZSCI) based heterojunction thin film coated on ITO is also reported.

  12. Design and realization of a GaAs FET integrated with a heterojunction photodiode

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    1595 Design and realization of a GaAs FET integrated with a heterojunction photodiode F. Therez, M, accepté le 6 juillet 1987) Résumé. 2014 L'association d'une photodiode à hétérojonction et d'un circuit circuits intégrant l'amplificateur et la photodiode. Les divers dispositifs sont caractérisés et analysés

  13. Fabrication of heterojunction solar cells by improved tin oxide deposition on insulating layer

    DOE Patents [OSTI]

    Feng, Tom (Morris Plains, NJ); Ghosh, Amal K. (New Providence, NJ)

    1980-01-01T23:59:59.000Z

    Highly efficient tin oxide-silicon heterojunction solar cells are prepared by heating a silicon substrate, having an insulating layer thereon, to provide a substrate temperature in the range of about 300.degree. C. to about 400.degree. C. and thereafter spraying the so-heated substrate with a solution of tin tetrachloride in a organic ester boiling below about 250.degree. C. Preferably the insulating layer is naturally grown silicon oxide layer.

  14. Thin-film polycrystalline n-ZnO/p-CuO heterojunction

    SciTech Connect (OSTI)

    Lisitski, O. L.; Kumekov, M. E.; Kumekov, S. E. [Satpaev Kazakh National Technical University (Kazakhstan)], E-mail: skumekov@mail.ru; Terukov, E. I. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation)

    2009-06-15T23:59:59.000Z

    Results of X-ray diffraction and spectral-optical studies of n-ZnO and p-CuO films deposited by gas-discharge sputtering with subsequent annealing are presented. It is shown that, despite the difference in the crystal systems, the polycrystallinity of n-ZnO and p-CuO films enables fabrication of a heterojunction from this pair of materials.

  15. Nanofluidics, from bulk to interfaces

    E-Print Network [OSTI]

    Lyderic Bocquet; Elisabeth Charlaix

    2009-09-03T23:59:59.000Z

    Nanofluidics has emerged recently in the footsteps of microfluidics, following the quest of scale reduction inherent to nanotechnologies. By definition, nanofluidics explores transport phenomena of fluids at the nanometer scales. Why is the nanometer scale specific ? What fluid properties are probed at nanometric scales ? In other words, why 'nanofluidics' deserves its own brand name ? In this critical review, we will explore the vast manifold of length scales emerging for the fluid behavior at the nanoscales, as well as the associated mechanisms and corresponding applications. We will in particular explore the interplay between bulk and interface phenomena. The limit of validity of the continuum approaches will be discussed, as well as the numerous surface induced effects occuring at these scales, from hydrodynamic slippage to the various electro-kinetic phenomena originating from the couplings between hydrodynamics and electrostatics. An enlightening analogy between ion transport in nanochannels and transport in doped semi-conductors will be discussed.

  16. Impact of surface morphology of Si substrate on performance of Si/ZnO heterojunction devices grown by atomic layer deposition technique

    SciTech Connect (OSTI)

    Hazra, Purnima; Singh, Satyendra Kumar [Department of Electronics and Communication Engineering, Motilal Neheru National Institute of Technology, Allahabad 211004 (India); Jit, Satyabrata, E-mail: sjit.ece@itbhu.ac.in [Department of Electronics Engineering, Indian Institute of Technology (BHU), Varanasi 221005 (India)

    2015-01-01T23:59:59.000Z

    In this paper, the authors have investigated the structural, optical, and electrical characteristics of silicon nanowire (SiNW)/zinc oxide (ZnO) core–shell nanostructure heterojunctions and compared their characteristics with Si/ZnO planar heterojunctions to investigate the effect of surface morphology of Si substrate in the characteristics of Si/ZnO heterojunction devices. In this work, ZnO thin film was conformally deposited on both p-type ?100? planar Si substrate and substrate with vertically aligned SiNW arrays by atomic layer deposition (ALD) method. The x-ray diffraction spectra show that the crystalline structures of Si/ZnO heterojunctions are having (101) preferred orientation, whereas vertically oriented SiNW/ZnO core–shell heterojunctions are having (002)-oriented wurtzite crystalline structures. The photoluminescence (PL) spectra of Si/ZnO heterojunctions show a very sharp single peak at 377?nm, corresponding to the bandgap of ZnO material with no other defect peaks in visible region; hence, these devices can have applications only in UV region. On the other hand, SiNW/ZnO heterojunctions are having band-edge peak at 378?nm along with a broad emission band, spreading almost throughout the entire visible region with a peak around 550?nm. Therefore, ALD-grown SiNW/ZnO heterojunctions can emit green and red light simultaneously. Reflectivity measurement of the heterojunctions further confirms the enhancement of visible region peak in the PL spectra of SiNW/ZnO heterojunctions, as the surface of the SiNW/ZnO heterojunctions exhibits extremely low reflectance (<3%) in the visible wavelength region compared to Si/ZnO heterojunctions (>20%). The current–voltage characteristics of both Si/ZnO and SiNW/ZnO heterojunctions are measured with large area ohmic contacts on top and bottom of the structure to compare the electrical characteristics of the devices. Due to large surface to-volume ratio of SiNW/ZnO core–shell heterojunction devices, the output current rating is about 130 times larger compared to their planar version at 2 V forward bias voltage. This higher output current rating can be exploited for fabricating high-performance nanoelectronic and optoelectronic devices in near future.

  17. Commercialization of Bulk Thermoelectric Materials for Power...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    & Publications Commercialization of Bulk Thermoelectric Materials for Power Generation Hydrogen Embrittlement of Pipeline Steels: Causes and Remediation Distributed Bio-Oil...

  18. Hyperon bulk viscosity in strong magnetic fields

    E-Print Network [OSTI]

    Monika Sinha; Debades Bandyopadhyay

    2009-06-06T23:59:59.000Z

    We study the bulk viscosity of neutron star matter including $\\Lambda$ hyperons in the presence of quantizing magnetic fields. Relaxation time and bulk viscosity due to both the non-leptonic weak process involving $\\Lambda$ hyperons and direct Urca processes are calculated here. In the presence of a strong magnetic field of $10^{17}$ G, the hyperon bulk viscosity coefficient is reduced whereas bulk viscosity coefficients due to direct Urca processes are enhanced compared with their field free cases when many Landau levels are populated by protons, electrons and muons.

  19. Recent Device Developments with Advanced Bulk Thermoelectric...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    at RTI Reviews work in engineered thin-film nanoscale thermoelectric materials and nano-bulk materials with high ZT undertaken by RTI in collaboration with its research...

  20. Scattering states of a particle, with position-dependent mass, in a ${\\cal{PT}}$ symmetric heterojunction

    E-Print Network [OSTI]

    Anjana Sinha

    2012-04-11T23:59:59.000Z

    The study of a particle with position-dependent effective mass (pdem), within a double heterojunction is extended into the complex domain --- when the region within the heterojunctions is described by a non Hermitian ${\\cal{PT}}$ symmetric potential. After obtaining the exact analytical solutions, the reflection and transmission coefficients are calculated, and plotted as a function of the energy. It is observed that at least two of the characteristic features of non Hermitian ${\\cal{PT}}$ symmetric systems --- viz., left / right asymmetry and anomalous behaviour at spectral singularity, are preserved even in the presence of pdem. The possibility of charge conservation is also discussed.

  1. Energy Level Alignment in PCDTBT:PC70BM Solar Cells: Solution Processed NiOx for Improved Hole Collection and Efficiency

    SciTech Connect (OSTI)

    Ratcliff, E. L.; Meyer, J.; Steirer, K. X.; Armstrong, N. R.; Olson, D.; Kahn, A.

    2012-05-01T23:59:59.000Z

    Solution-based NiO{sub x} outperforms PEDOT:PSS in device performance and stability when used as a hole-collection layer in bulk-heterojunction (BHJ) solar cells formed with poly[N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) and PC70BM. The origin of the enhancement is clarified by studying the interfacial energy level alignment between PCDTBT or the 1:4 blended heterojunctions and PEDOT:PSS or NiO{sub x} using ultraviolet and inverse photoemission spectroscopies. The 1.6 eV electronic gap of PEDOT:PSS and energy level alignment with the BHJ result in poor hole selectivity of PEDOT:PSS and allows electron recombination at the PEDOT:PSS/BHJ interface. Conversely, the large band gap (3.7 eV) of NiO{sub x} and interfacial dipole (0.6 eV) with the organic active layer leads to a hole-selective interface. This interfacial dipole yields enhanced electron blocking properties by increasing the barrier to electron injection. The presence of such a strong dipole is predicted to further promote hole collection from the organic layer into the oxide, resulting in increased fill factor and short circuit current. An overall decrease in recombination is manifested in an increase in open circuit voltage and power conversion efficiency of the device on NiO{sub x} versus PEDOT:PSS interlayers.

  2. Phonon blocking by two dimensional electron gas in polar CdTe/PbTe heterojunctions

    SciTech Connect (OSTI)

    Zhang, Bingpo; Cai, Chunfeng; Zhu, He; Wu, Feifei; Ye, Zhenyu; Chen, Yongyue; Li, Ruifeng; Kong, Weiguang; Wu, Huizhen, E-mail: hzwu@zju.edu.cn [Department of Physics and State Key Laboratory of Silicon Materials, Zhejiang University, Hangzhou, Zhejiang 310027 (China)

    2014-04-21T23:59:59.000Z

    Narrow-gap lead telluride crystal is an important thermoelectric and mid-infrared material in which phonon functionality is a critical issue to be explored. In this Letter, efficient phonon blockage by forming a polar CdTe/PbTe heterojunction is explicitly observed by Raman scattering. The unique phonon screening effect can be interpreted by recent discovery of high-density two dimensional electrons at the polar CdTe/PbTe(111) interface which paves a way for design and fabrication of thermoelectric devices.

  3. Indium tin oxide and indium phosphide heterojunction nanowire array solar cells

    SciTech Connect (OSTI)

    Yoshimura, Masatoshi, E-mail: yoshimura@rciqe.hokudai.ac.jp; Nakai, Eiji; Fukui, Takashi [Graduate School of Information Science and Technology, and Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, Kita 13 Nishi 8, Sapporo 060–8628 (Japan)] [Graduate School of Information Science and Technology, and Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, Kita 13 Nishi 8, Sapporo 060–8628 (Japan); Tomioka, Katsuhiro [Graduate School of Information Science and Technology, and Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, Kita 13 Nishi 8, Sapporo 060–8628 (Japan) [Graduate School of Information Science and Technology, and Research Center for Integrated Quantum Electronics (RCIQE), Hokkaido University, Kita 13 Nishi 8, Sapporo 060–8628 (Japan); PRESTO, Japan Science and Technology Agency (JST), Honcho Kawaguchi, 332–0012 Saitama (Japan)

    2013-12-09T23:59:59.000Z

    Heterojunction solar cells were formed with a position-controlled InP nanowire array sputtered with indium tin oxide (ITO). The ITO not only acted as a transparent electrode but also as forming a photovoltaic junction. The devices exhibited an open-circuit voltage of 0.436?V, short-circuit current of 24.8?mA/cm{sup 2}, and fill factor of 0.682, giving a power conversion efficiency of 7.37% under AM1.5?G illumination. The internal quantum efficiency of the device was higher than that of the world-record InP cell in the short wavelength range.

  4. Built-in voltage of organic bulk heterojuction p-i-n solar cells measured by electroabsorption spectroscopy

    SciTech Connect (OSTI)

    Siebert-Henze, E., E-mail: ellen.siebert@iapp.de; Lyssenko, V. G.; Fischer, J.; Tietze, M.; Brueckner, R.; Schwarze, M.; Vandewal, K.; Ray, D.; Riede, M.; Leo, K. [Institut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden (Germany)] [Institut für Angewandte Photophysik, Technische Universität Dresden, D-01062 Dresden (Germany)

    2014-04-15T23:59:59.000Z

    We investigate the influence of the built-in voltage on the performance of organic bulk heterojuction solar cells that are based on a p-i-n structure. Electrical doping in the hole and the electron transport layer allows to tune their work function and hence to adjust the built-in voltage: Changing the doping concentration from 0.5 to 32 wt% induces a shift of the work function towards the transport levels and increases the built-in voltage. To determine the built-in voltage, we use electroabsorption spectroscopy which is based on an evaluation of the spectra caused by a change in absorption due to an electric field (Stark effect). For a model system with a bulk heterojunction of BF-DPB and C{sub 60}, we show that higher doping concentrations in both the electron and the hole transport layer increase the built-in voltage, leading to an enhanced short circuit current and solar cell performance.

  5. The Bulk Viscosity of a Pion Gas

    E-Print Network [OSTI]

    Egang Lu; Guy D. Moore

    2011-01-31T23:59:59.000Z

    We compute the bulk viscosity of a gas of pions at temperatures below the QCD crossover temperature, for the physical value of pion mass, to lowest order in chiral perturbation theory. Bulk viscosity is controlled by number-changing processes which become exponentially slow at low temperatures when the pions become exponentially dilute, leading to an exponentially large bulk viscosity zeta ~ (F_0^8/m_\\pi^5) exp(2m_\\pi/T), where F_0 = 93 MeV is the pion decay constant.

  6. Bulk viscosity of N=2* plasma

    E-Print Network [OSTI]

    Alex Buchel; Chris Pagnutti

    2009-03-02T23:59:59.000Z

    We use gauge theory/string theory correspondence to study the bulk viscosity of strongly coupled, mass deformed SU(N_c) N=4 supersymmetric Yang-Mills plasma, also known as N=2^* gauge theory. For a wide range of masses we confirm the bulk viscosity bound proposed in arXiv:0708.3459. For a certain choice of masses, the theory undergoes a phase transition with divergent specific heat c_V ~ |1-T_c/T|^(-1/2). We show that, although bulk viscosity rapidly grows as T -> T_c, it remains finite in the vicinity of the critical point.

  7. Improved CNT-Si heterojunction solar cell with structured single-walled carbon nanotubes Shigeo Maruyama1

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Improved CNT-Si heterojunction solar cell with structured single-walled carbon nanotubes Shigeo of Tokyo, Japan 113-8656 2 Department of Applied Physics, Aalto University School of Science, Finland 3, mechanical, and thermal properties are expected to be the most promising materials for next-generation energy

  8. Hole-conductor-free perovskite organic lead iodide heterojunction thin-film solar cells: High efficiency and junction property

    E-Print Network [OSTI]

    Wang, Wei Hua

    Hole-conductor-free perovskite organic lead iodide heterojunction thin-film solar cells: High-conductor-free organic lead iodide thin film solar cells have been fabricated with a sequential deposition method are comparable to that of the high-efficiency thin-film solar cells. VC 2014 AIP Publishing LLC. [http

  9. 3D branched nanowire heterojunction photoelectrodes for high-efficiency solar water splitting and H2 generation

    E-Print Network [OSTI]

    Wang, Deli

    , it is essential to find a cost-effective and clean method for mass production of hydrogen.6 Techniques for directly con- verting water to hydrogen using solar energy, known as photo- electrolysis, are receiving dimensional branched ZnO/Si heterojunction nanowire array by a two-step, wafer-scale, low-cost, solution

  10. Robust Superlubricity in Graphene/hBN Heterojunctions Itai Leven, Dana Krepel, Ortal Shemesh, and Oded Hod*

    E-Print Network [OSTI]

    Hod, Oded

    Robust Superlubricity in Graphene/hBN Heterojunctions Itai Leven, Dana Krepel, Ortal Shemesh: The sliding energy landscape of the heterogeneous graphene/h- BN interface is studied by means of the registry index. For a graphene flake sliding on top of h-BN, the anisotropy of the sliding energy corrugation

  11. Controlled CVD Growth of Single-Walled Carbon Nanotubes and Application to CNT-Si Heterojunction Solar Cells

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Solar Cells Shigeo Maruyama Department of Mechanical Engineering, The University of Tokyo 113 controlled assembly of SWNTs for SWNT-Si heterojunction solar cells will be discussed. We found was found to be encapsulated diatomic N2 molecules interior of SWNTs with the content of 1 at %. We address

  12. Self-Assembled Micro-Honeycomb Network of Single-Walled Carbon Nanotubes for Heterojunction Solar Cell

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Self-Assembled Micro-Honeycomb Network of Single-Walled Carbon Nanotubes for Heterojunction Solar. Here, we propose a self-organized micro- honeycomb network structure of SWNTs obtained by water@photon.t.u-tokyo.ac.jp) Various forms of nano-carbon films such as random network of single-walled carbon nanotubes (SWNTs

  13. 19.2% Efficient InP Heterojunction Solar Cell with Electron-Selective TiO2 Contact

    E-Print Network [OSTI]

    Javey, Ali

    19.2% Efficient InP Heterojunction Solar Cell with Electron-Selective TiO2 Contact Xingtian Yin of California, Berkeley, California 94720, United States Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States § Electronic Materials Research Laboratory

  14. Crystal Silicon Heterojunction Solar Cells by Hot-Wire CVD: Preprint

    SciTech Connect (OSTI)

    Wang, Q.; Page, M. R.; Iwaniczko, E.; Xu, Y. Q.; Roybal, L.; Bauer, R.; To, B.; Yuan, H. C.; Duda, A.; Yan, Y. F.

    2008-05-01T23:59:59.000Z

    Hot-wire chemical vapor deposition (HWCVD) is a promising technique for fabricating Silicon heterojunction (SHJ) solar cells. In this paper we describe our efforts to increase the open circuit voltage (Voc) while improving the efficiency of these devices. On p-type c-Si float-zone wafers, we used a double heterojunction structure with an amorphous n/i contact to the top surface and an i/p contact to the back surface to obtain an open circuit voltage (Voc) of 679 mV in a 0.9 cm2 cell with an independently confirmed efficiency of 19.1%. This is the best reported performance for a cell of this configuration. We also made progress on p-type CZ wafers and achieved 18.7% independently confirmed efficiency with little degradation under prolong illumination. Our best Voc for a p-type SHJ cell is 0.688 V, which is close to the 691 mV we achieved for SHJ cells on n type c-Si wafers.

  15. Band alignment and interfacial structure of ZnO/Si heterojunction with Al{sub 2}O{sub 3} and HfO{sub 2} as interlayers

    SciTech Connect (OSTI)

    Lu, Hong-Liang, E-mail: honglianglu@fudan.edu.cn; Yang, Ming; Xie, Zhang-Yi; Geng, Yang; Zhang, Yuan; Wang, Peng-Fei; Sun, Qing-Qing; Ding, Shi-Jin; Wei Zhang, David [State Key Laboratory of ASIC and System, Institute of Advanced Nanodevices, School of Microelectronics, Fudan University, Shanghai 200433 (China)

    2014-04-21T23:59:59.000Z

    Energy band alignment of ZnO/Si heterojunction with thin interlayers Al{sub 2}O{sub 3} and HfO{sub 2} grown by atomic layer deposition has been studied using x-ray photoelectron spectroscopy. The valence band offsets of ZnO/Al{sub 2}O{sub 3} and ZnO/HfO{sub 2} heterojunctions have been determined to be 0.43 and 0.22?eV, respectively. Accordingly, the band alignment ZnO/Si heterojunction is then modified to be 0.34 and 0.50?eV through inserting a thin Al{sub 2}O{sub 3} and HfO{sub 2} layer, respectively. The feasibility to tune the band structure of ZnO/Si heterojunction by selecting a proper interlayer shows great advantage in improving the performance of the ZnO-based optoelectronic devices.

  16. High Heat Flux Thermoelectric Module Using Standard Bulk Material...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Heat Flux Thermoelectric Module Using Standard Bulk Material High Heat Flux Thermoelectric Module Using Standard Bulk Material Presents high heat flux thermoelectric module design...

  17. Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    High-Temperature Bulk Thermoelectric Energy Conversion for Efficient Automotive Waste Heat Recovery Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion for...

  18. Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery...

    Broader source: Energy.gov (indexed) [DOE]

    Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery Workshop Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery Workshop Targets, barriers and...

  19. Photocurrent enhancement of perovskite heterojunction by plasmonic nanoparticles and ferroelectric polarization

    SciTech Connect (OSTI)

    Shieh, J., E-mail: jayshieh@ntu.edu.tw; Chen, S. W.; Fang, C. Y.; Chen, C. H. [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan (China)

    2014-02-17T23:59:59.000Z

    Perovskite oxides—Pb{sub 0.86}La{sub 0.14}TiO{sub 3} (PLT), AgNbO{sub 3} (ANO), and SrTiO{sub 3} (STO)—were deposited consecutively on ITO/glass substrates to form layered composite photoelectrodes. These materials were chosen for their specific electronic band structures to form efficient photocatalytic heterojunctions and similar crystalline structures to minimize interface defects. Two additional methods were adopted to increase the photocurrent density of the composites: (1) plasmonic gold nanoparticles were introduced at the PLT/ITO interface to enhance light scattering and absorption while not becoming electron trapping centers and (2) the ferroelectric PLT layer was electrically poled toward the ANO layer to create a favorable band bending for electron transfer.

  20. Thin film heterojunction photovoltaic cells and methods of making the same

    DOE Patents [OSTI]

    Basol, Bulent M. (Los Angeles, CA); Tseng, Eric S. (Los Angeles, CA); Rod, Robert L. (Los Angeles, CA)

    1983-06-14T23:59:59.000Z

    A method of fabricating a thin film heterojunction photovoltaic cell which comprises depositing a film of a near intrinsic or n-type semiconductor compound formed of at least one of the metal elements of Class II B of the Periodic Table of Elements and at least tellurium and then heating said film at a temperature between about 250.degree. C. and 500.degree. C. for a time sufficient to convert said film to a suitably low resistivity p-type semiconductor compound. Such film may be deposited initially on the surface of an n-type semiconductor substrate. Alternatively, there may be deposited on the converted film a layer of n-type semiconductor compound different from the film semiconductor compound. The resulting photovoltaic cell exhibits a substantially increased power output over similar cells not subjected to the method of the present invention.

  1. Infrared electroluminescence from GeSn heterojunction diodes grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Gupta, Jay Prakash; Bhargava, Nupur; Kim, Sangcheol; Kolodzey, James [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States)] [Department of Electrical and Computer Engineering, University of Delaware, Newark, Delaware 19716 (United States); Adam, Thomas [Nanofab, University of Albany, SUNY, Albany, New York 12203 (United States)] [Nanofab, University of Albany, SUNY, Albany, New York 12203 (United States)

    2013-06-24T23:59:59.000Z

    Infrared electroluminescence was observed from GeSn/Ge p-n heterojunction diodes with 8% Sn, grown by molecular beam epitaxy. The GeSn layers were boron doped, compressively strained, and pseudomorphic on Ge substrates. Spectral measurements indicated an emission peak at 0.57 eV, about 50 meV wide, increasing in intensity with applied pulsed current, and with reducing device temperatures. The total integrated emitted power from a single edge facet was 54 {mu}W at an applied peak current of 100 mA at 100 K. These results suggest that GeSn-based materials maybe useful for practical light emitting diodes operating in the infrared wavelength range near 2 {mu}m.

  2. Micro benchtop optics by bulk silicon micromachining

    DOE Patents [OSTI]

    Lee, Abraham P. (Walnut Creek, CA); Pocha, Michael D. (Livermore, CA); McConaghy, Charles F. (Livermore, CA); Deri, Robert J. (Pleasanton, CA)

    2000-01-01T23:59:59.000Z

    Micromachining of bulk silicon utilizing the parallel etching characteristics of bulk silicon and integrating the parallel etch planes of silicon with silicon wafer bonding and impurity doping, enables the fabrication of on-chip optics with in situ aligned etched grooves for optical fibers, micro-lenses, photodiodes, and laser diodes. Other optical components that can be microfabricated and integrated include semi-transparent beam splitters, micro-optical scanners, pinholes, optical gratings, micro-optical filters, etc. Micromachining of bulk silicon utilizing the parallel etching characteristics thereof can be utilized to develop miniaturization of bio-instrumentation such as wavelength monitoring by fluorescence spectrometers, and other miniaturized optical systems such as Fabry-Perot interferometry for filtering of wavelengths, tunable cavity lasers, micro-holography modules, and wavelength splitters for optical communication systems.

  3. Decision Models for Bulk Energy Transportation Networks

    E-Print Network [OSTI]

    Tesfatsion, Leigh

    -mouth generation at Powder River Basin · How much impact would 25% wind penetration have on price ? 2 What is modeled · spatial & temporal · energy flows · nodal prices (fuel & elec) · SO2, allowance price1 Decision Models for Bulk Energy Transportation Networks Electrical Engineering Professor Jim Mc

  4. INVESTIGATION OF BULK POWER ERCOT (Texas)

    E-Print Network [OSTI]

    Laughlin, Robert B.

    . . . . . . . . . . . . . . . . . . . . . . . . 4-4 D. The New Wholesale Market and the Move Toward Retail Choice . . . . . . . . . . 4-6 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-13 1. The Short-Term Energy Market . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4INVESTIGATION OF BULK POWER MARKETS ERCOT (Texas) November 1, 2000 The analyses and conclusions

  5. Features of the electroluminescence spectra of quantum-confined silicon p{sup +}-n heterojunctions in the infrared spectral region

    SciTech Connect (OSTI)

    Bagraev, N. T.; Klyachkin, L. E.; Kuzmin, R. V., E-mail: roman.kuzmin@mail.ioffe.ru; Malyarenko, A. M. [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation)] [Russian Academy of Sciences, Ioffe Physical-Technical Institute (Russian Federation); Mashkov, V. A. [Saint Petersburg State Polytechnical University (Russian Federation)] [Saint Petersburg State Polytechnical University (Russian Federation)

    2013-11-15T23:59:59.000Z

    The results of studying the characteristics of optical emission in various regions of quantum-confined silicon p{sup +}-n heterojunctions heavily doped with boron are analyzed. The results obtained allow one to conclude that near-infrared electroluminescence arises near the heterointerface between the nanostructured wide-gap silicon p{sup +}-barrier heavily doped with boron and n-type silicon (100), the formation of which included the active involvement of boron dipole centers.

  6. Well-Passivated a-Si:H Back Contacts for Double-Heterojunction Silicon Solar Cells: Preprint

    SciTech Connect (OSTI)

    Page, M. R.; Iwaniczko, E.; Xu, Y.; Wang, Q.; Yan, Y.; Roybal, L.; Branz, H. M.; Wang, T. H.

    2006-05-01T23:59:59.000Z

    We have developed hydrogenated amorphous silicon (a Si:H) back contacts to both p- and n-type silicon wafers, and employed them in double-heterojunction solar cells. These contacts are deposited entirely at low temperature (<250 C) and replace the standard diffused or alloyed back-surface-field contacts used in single-heterojunction (front-emitter only) cells. High-quality back contacts require excellent surface passivation, indicated by a low surface recombination velocity of minority-carriers (S) or a high open-circuit voltage (Voc). The back contact must also provide good conduction for majority carriers to the external circuit, as indicated by a high light I-V fill factor. We use hot-wire chemical vapor deposition (HWCVD) to grow a-Si:H layers for both the front emitters and back contacts. Our improved a-Si:H back contacts contribute to our recent achievement of a confirmed 18.2% efficiency in double-heterojunction silicon solar cells on p type textured silicon wafers.

  7. MoS{sub 2}@ZnO nano-heterojunctions with enhanced photocatalysis and field emission properties

    SciTech Connect (OSTI)

    Tan, Ying-Hua; Yu, Ke, E-mail: yk5188@263.net; Li, Jin-Zhu; Fu, Hao; Zhu, Zi-Qiang [Key Laboratory of Polar Materials and Devices (Ministry of Education of China), Department of Electronic Engineering, East China Normal University, Shanghai 200241 (China)

    2014-08-14T23:59:59.000Z

    The molybdenum disulfide (MoS{sub 2})@ZnO nano-heterojunctions were successfully fabricated through a facile three-step synthetic process: prefabrication of the ZnO nanoparticles, the synthesis of MoS{sub 2} nanoflowers, and the fabrication of MoS{sub 2}@ZnO heterojunctions, in which ZnO nanoparticles were uniformly self-assembled on the MoS{sub 2} nanoflowers by utilizing polyethyleneimine as a binding agent. The photocatalytic activities of the composite samples were evaluated by monitoring the photodegradation of methylene blue (MB). Compared with pure MoS{sub 2} nanoflowers, the composites show higher adsorption capability in dark and better photocatalytic efficiency due to the increased specific surface area and improved electron-hole pair separation. After irradiation for 100?min, the remaining MB in solution is about 7.3%. Moreover, the MoS{sub 2}@ZnO heterojunctions possess enhanced field emission properties with lower turn-on field of 3.08?V ?m{sup ?1}and lower threshold field of 6.9?V ?m{sup ?1} relative to pure MoS{sub 2} with turn-on field of 3.65?V ?m{sup ?1} and threshold field of 9.03?V ?m{sup ?1}.

  8. Development and characterization of PCDTBT:CdSe QDs hybrid solar cell

    SciTech Connect (OSTI)

    Dixit, Shiv Kumar, E-mail: shivkumardixit.7@gmail.com; Bhatnagar, Chhavi, E-mail: shivkumardixit.7@gmail.com; Kumari, Anita, E-mail: shivkumardixit.7@gmail.com; Madhwal, Devinder, E-mail: shivkumardixit.7@gmail.com; Bhatnagar, P. K., E-mail: shivkumardixit.7@gmail.com; Mathur, P. C., E-mail: shivkumardixit.7@gmail.com [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, New Delhi, 110021 (India)

    2014-10-15T23:59:59.000Z

    Solar cell consisting of low band gap polymer poly[N-900-hepta-decanyl-2,7-carbazole-alt-5,5-(40,70-di-2-thienyl-20,10, 30-benzothiadiazole)] (PCDTBT) as donor and cadmium selenide/zinc sulphide (CdSe/ZnS) core shell quantum dots (QDs) as an acceptor has been developed. The absorption measurements show that the absorption coefficient increases in bulk heterojunction (BHJ) structure covering broad absorption spectrum (200nm–700nm). Also, the photoluminescence (PL) of the PCDTBT:QDs film is found to decrease by an order of magnitude showing a significant transfer of electrons to the QDs. With this approach and under broadband white light with an irradiance of 8.19 mW/cm{sup 2}, we have been able to achieve a power conversion efficiency (PCE) of 3.1 % with fill factor 0.42 for our typical solar cell.

  9. Microfabricated bulk wave acoustic bandgap device

    DOE Patents [OSTI]

    Olsson, Roy H.; El-Kady, Ihab F.; McCormick, Frederick; Fleming, James G.; Fleming leg, Carol

    2010-06-08T23:59:59.000Z

    A microfabricated bulk wave acoustic bandgap device comprises a periodic two-dimensional array of scatterers embedded within the matrix material membrane, wherein the scatterer material has a density and/or elastic constant that is different than the matrix material and wherein the periodicity of the array causes destructive interference of the acoustic wave within an acoustic bandgap. The membrane can be suspended above a substrate by an air or vacuum gap to provide acoustic isolation from the substrate. The device can be fabricated using microelectromechanical systems (MEMS) technologies. Such microfabricated bulk wave phononic bandgap devices are useful for acoustic isolation in the ultrasonic, VHF, or UHF regime (i.e., frequencies of order 1 MHz to 10 GHz and higher, and lattice constants of order 100 .mu.m or less).

  10. Microfabricated bulk wave acoustic bandgap device

    DOE Patents [OSTI]

    Olsson, Roy H. (Albuquerque, NM); El-Kady, Ihab F. (Albuquerque, NM); McCormick, Frederick (Albuquerque, NM); Fleming, James G. (Albuquerque, NM); Fleming, legal representative, Carol (Albuquerque, NM)

    2010-11-23T23:59:59.000Z

    A microfabricated bulk wave acoustic bandgap device comprises a periodic two-dimensional array of scatterers embedded within the matrix material membrane, wherein the scatterer material has a density and/or elastic constant that is different than the matrix material and wherein the periodicity of the array causes destructive interference of the acoustic wave within an acoustic bandgap. The membrane can be suspended above a substrate by an air or vacuum gap to provide acoustic isolation from the substrate. The device can be fabricated using microelectromechanical systems (MEMS) technologies. Such microfabricated bulk wave phononic bandgap devices are useful for acoustic isolation in the ultrasonic, VHF, or UHF regime (i.e., frequencies of order 1 MHz to 10 GHz and higher, and lattice constants of order 100 .mu.m or less).

  11. A Bulk Parameterization of Giant CCN

    E-Print Network [OSTI]

    Mechem, David B.; Kogan, Yefim L.

    2008-07-01T23:59:59.000Z

    ), growth by condensation, and growth by coalescence (Beard and Ochs 1993). The long time scale required for conden- sational growth of droplets large enough for collection efficiencies to become significant has been a subject of ongoing investigation.... Bulk microphysical parameterizations traditionally partition the total liquid water into two categories, cloud and rainwater, based on a threshold radius of 20–25 #2;m. The most important effect of GCCN is through their impact on precipitation...

  12. Hydrogen isotope separation utilizing bulk getters

    DOE Patents [OSTI]

    Knize, Randall J. (Los Angeles, CA); Cecchi, Joseph L. (Lawrenceville, NJ)

    1991-01-01T23:59:59.000Z

    Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen.

  13. Hydrogen isotope separation utilizing bulk getters

    DOE Patents [OSTI]

    Knize, Randall J. (Los Angeles, CA); Cecchi, Joseph L. (Lawrenceville, NJ)

    1990-01-01T23:59:59.000Z

    Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen.

  14. Hydrogen isotope separation utilizing bulk getters

    DOE Patents [OSTI]

    Knize, R.J.; Cecchi, J.L.

    1991-08-20T23:59:59.000Z

    Tritium and deuterium are separated from a gaseous mixture thereof, derived from a nuclear fusion reactor or some other source, by providing a casing with a bulk getter therein for absorbing the gaseous mixture to produce an initial loading of the getter, partially desorbing the getter to produce a desorbed mixture which is tritium-enriched, pumping the desorbed mixture into a separate container, the remaining gaseous loading in the getter being deuterium-enriched, desorbing the getter to a substantially greater extent to produce a deuterium-enriched gaseous mixture, and removing the deuterium-enriched mixture into another container. The bulk getter may comprise a zirconium-aluminum alloy, or a zirconium-vanadium-iron alloy. The partial desorption may reduce the loading by approximately fifty percent. The basic procedure may be extended to produce a multistage isotope separator, including at least one additional bulk getter into which the tritium-enriched mixture is absorbed. The second getter is then partially desorbed to produce a desorbed mixture which is further tritium-enriched. The last-mentioned mixture is then removed from the container for the second getter, which is then desorbed to a substantially greater extent to produce a desorbed mixture which is deuterium-enriched. The last-mentioned mixture is then removed so that the cycle can be continued and repeated. The method of isotope separation is also applicable to other hydrogen isotopes, in that the method can be employed for separating either deuterium or tritium from normal hydrogen. 4 figures.

  15. Methods for forming thin-film heterojunction solar cells from I-III-VI{sub 2}

    DOE Patents [OSTI]

    Mickelsen, R.A.; Chen, W.S.

    1985-08-13T23:59:59.000Z

    An improved thin-film, large area solar cell, and methods for forming the same are disclosed, having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n type heterojunction formed of: (i) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI{sub 2} chalcopyrite ternary materials which is vacuum deposited in a thin ``composition-graded`` layer ranging from on the order of about 2.5 microns to about 5.0 microns ({approx_equal}2.5 {mu}m to {approx_equal}5.0 {mu}m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (ii) a second semiconductor layer comprising a low resistivity n-type semiconductor material; wherein interdiffusion occurs (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer. 16 figs.

  16. Low temperature front surface passivation of interdigitated back contact silicon heterojunction solar cell

    SciTech Connect (OSTI)

    Shu, Brent; Das, Ujjwal; Jani, Omkar; Hegedus, Steve; Birkmire, Robert

    2009-06-08T23:59:59.000Z

    The interdigitated back contact silicon heterojunction (IBC-SHJ) solar cell requires a low temperature front surface passivation/anti-reflection structure. Conventional silicon surface passivation using SiO2 or a-SiNx is performed at temperature higher than 400°C, which is not suitable for the IBC-SHJ cell. In this paper, we propose a PECVD a-Si:H/a-SiNx:H/a-SiC:H stack structure to passivate the front surface of crystalline silicon at low temperature. The optical properties and passivation quality of this structure are characterized and solar cells using this structure are fabricated. With 2 nm a-Si:H layer, the stack structure exhibits stable passivation with effective minority carrier lifetime higher than 2 ms, and compatible with IBC-SHJ solar cell processing. A critical advantage of this structure is that the SiC allows it to be HF resistant, thus it can be deposited as the first step in the process. This protects the a-Si/c-Si interface and maintains a low surface recombination velocity.

  17. Hetero-junction photovoltaic device and method of fabricating the device

    DOE Patents [OSTI]

    Aytug, Tolga; Christen, David K; Paranthaman, Mariappan Parans; Polat, Ozgur

    2014-02-10T23:59:59.000Z

    A hetero-junction device and fabrication method in which phase-separated n-type and p-type semiconductor pillars define vertically-oriented p-n junctions extending above a substrate. Semiconductor materials are selected for the p-type and n-type pillars that are thermodynamically stable and substantially insoluble in one another. An epitaxial deposition process is employed to form the pillars on a nucleation layer and the mutual insolubility drives phase separation of the materials. During the epitaxial deposition process, the orientation is such that the nucleation layer initiates propagation of vertical columns resulting in a substantially ordered, three-dimensional structure throughout the deposited material. An oxidation state of at least a portion of one of the p-type or the n-type semiconductor materials is altered relative to the other, such that the band-gap energy of the semiconductor materials differ with respect to stoichiometric compositions and the device preferentially absorbs particular selected bands of radiation.

  18. GaAsSb-based heterojunction tunnel diodes for tandem solar cell interconnects

    SciTech Connect (OSTI)

    Zolper, J.C.; Klem, J.F.; Plut, T.A.; Tigges, C.P.

    1995-01-01T23:59:59.000Z

    We report a new approach to tunnel junctions that employs a pseudomorphic GaAsSb layer to obtain a band alignment at a InGaAs or InAlAs p-n junction favorable for forward bias tunneling. Since the majority of the band offset between GaAsSb and InGaAs or InAlAs is in the valence band, when an GaAsSb layer is placed at an InGaAs or InAlAs p-n junction the tunneling distance is reduced and the tunneling current is increased. For all doping levels studied, the presence of the GaAsSb-layer enhanced the forward tunneling characteristics. In fact, in a InGaAs/GaAsSb tunnel diode a peak tunneling current sufficient for a 1000 sun intercell interconnect was achieved with p = 1.5{times}l0{sup 18} cm{sup -3} while a similarly doped all-InGaAs diode was rectifying. This approach affords a new degree of freedom in designing tunnel junctions for tandem solar cell interconnects. Previously only doping levels could be varied to control the tunneling properties. Our approach relaxes the doping requirements by employing a GaAsSb-based heterojunction.

  19. Electroluminescence from ZnO/Si heterojunctions fabricated by PLD with bias voltage application

    SciTech Connect (OSTI)

    Seno, Yuuki; Konno, Daisuke; Komiyama, Takao; Chonan, Yasunori; Yamaguchi, Hiroyuki; Aoyama, Takashi [Electronics and Information Systems, Akita Prefectural Univ. Yuri-honjo, Akita 015-0055 (Japan)

    2014-02-21T23:59:59.000Z

    Electroluminescence (EL) for ZnO films has been investigated by fabricating n-ZnO/p-Si heterojunctions and changing the VI/II (O/Zn) ratio of the films. In the photoluminescence (PL) spectra, both the near band edge (NBE) emission and the defect-related emission were observed, while in the EL spectra only defect-related emission was observed. The EL spectra were divided into three components: green (550 nm), yellow (618 nm) and red (700 nm) bands; and their intensities were compared. As the VI/II (O/Zn) ratio was increased, the red band emission intensity decreased and the green band emission intensity increased. This implies that the oxygen and the zinc vacancies are related to the red and the green band emissions, respectively. Electron transitions from the conduction band minimum (Ec) to the deep energy levels of these vacancies are suggested to cause the red and the green luminescences while the energy levels of the Zn interstitials are close to the Ec in the band gap and no NBE emission is observed.

  20. Methods for forming thin-film heterojunction solar cells from I-III-VI.sub. 2

    DOE Patents [OSTI]

    Mickelsen, Reid A. (Bellevue, WA) [Bellevue, WA; Chen, Wen S. (Seattle, WA) [Seattle, WA

    1985-08-13T23:59:59.000Z

    An improved thin-film, large area solar cell, and methods for forming the same, having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n type heterojunction formed of: (i) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI.sub.2 chalcopyrite ternary materials which is vacuum deposited in a thin "composition-graded" layer ranging from on the order ot about 2.5 microns to about 5.0 microns (.congruent.2.5 .mu.m to .congruent.5.0 .mu.m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (ii), a second semiconductor layer comprising a low resistivity n-type semiconductor material; wherein interdiffusion (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer, causes the The Government has rights in this invention pursuant to Contract No. EG-77-C-01-4042, Subcontract No. XJ-9-8021-1 awarded by the U.S. Department of Energy.

  1. Design, fabrication, and analysis of p-channel arsenide/antimonide hetero-junction tunnel transistors

    SciTech Connect (OSTI)

    Rajamohanan, Bijesh, E-mail: bor5067@psu.edu; Mohata, Dheeraj; Hollander, Matthew; Datta, Suman [Department of Electrical Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Zhu, Yan; Hudait, Mantu [Bradley Department of Electrical and Computer Engineering, Virginia Tech, Blacksburg, Virginia 24061 (United States); Jiang, Zhengping; Klimeck, Gerhard [Department of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47906 (United States)

    2014-01-28T23:59:59.000Z

    In this paper, we demonstrate InAs/GaSb hetero-junction (hetJ) and GaSb homo-junction (homJ) p-channel tunneling field effect transistors (pTFET) employing a low temperature atomic layer deposited high-? gate dielectric. HetJ pTFET exhibited drive current of 35 ?A/?m in comparison to homJ pTFET, which exhibited drive current of 0.3 ?A/?m at V{sub DS}?=??0.5?V under DC biasing conditions. Additionally, with pulsing of 1 ?s gate voltage, hetJ pTFET exhibited enhanced drive current of 85 ?A/?m at V{sub DS}?=??0.5?V, which is the highest reported in the category of III-V pTFET. Detailed device characterization was performed through analysis of the capacitance-voltage characteristics, pulsed current-voltage characteristics, and x-ray diffraction studies.

  2. Asymmetric Electron Transport at Monolayer-Bilayer Heterojunctions of Epitaxial Graphene

    SciTech Connect (OSTI)

    Li, An-Ping [ORNL] [ORNL; Clark, Kendal W [ORNL] [ORNL; Zhang, Xiaoguang [ORNL] [ORNL; Gu, Gong [University of Tennessee, Knoxville (UTK)] [University of Tennessee, Knoxville (UTK); He, Guowei [Carnegie Mellon University (CMU)] [Carnegie Mellon University (CMU); Feenstra, Randall [Carnegie Mellon University (CMU)] [Carnegie Mellon University (CMU)

    2014-01-01T23:59:59.000Z

    The symmetry of the graphene honeycomb lattice is a key element determining many of graphene s unique electronic properties, such as the linear energy-momentum dispersion and the suppressed backscattering 1,2. However, line defects in large-scale epitaxial graphene films, such as grain boundaries, edges, surface steps, and changes in layer thickness, often break the sublatttice symmetry and can impact transport properties of graphene profoundly 3-6. Here we report asymmetric electron transport upon polarity reversal at individual monolayer-bilayer (ML-BL) boundaries in epitaxial graphene on SiC (0001), revealed by scanning tunneling potentiometry. A greater voltage drop is observed when the current flows from BL to ML graphene than in the reverse direction, and the difference remains nearly unchanged with increasing current. This is not a typical nonlinear conductance due to electron transmission through an asymmetric potential. Rather, it indicates the opening of a dynamic energy gap at the Fermi energy due to the Coulomb interaction between the injected nonequilibrium electron density and the pseudospin polarized Friedel oscillation charge density at the boundary. This intriguing heterojunction transport behavior opens a new avenue towards novel quantum functions such as quantum switching.

  3. Determination of subband energies and 2DEG characteristics of Al{sub x}Ga{sub 1?x}N/GaN heterojunctions using variational method

    SciTech Connect (OSTI)

    Manouchehri, Farzin; Valizadeh, Pouya; Kabir, M. Z., E-mail: kabir@encs.concordia.ca [Department of Electrical and Computer Engineering, Concordia University, Montreal, H3G 1M8 (Canada)

    2014-03-15T23:59:59.000Z

    A physics-based model based on the variational method for analyzing the two dimensional electron gas (2DEG) characteristics of polar AlGaN/GaN heterojunctions is developed. The 2DEG carrier concentration, the first and second energy subbands, and the position of the Fermi energy level are calculated for various barrier thicknesses, Al mole fractions, background dopant concentrations, and gate voltages for gated AlGaN/GaN heterojunctions. The results are in good agreement with the data reported based on self-consistent method. Whereas the aforementioned report has dealt with specific values of Al mole fraction, barrier thickness, and unintentional doping level, the present work provides a basis for calculating the 2DEG characteristics for the full range of these parameters. Furthermore, according to the proposed model, the applicability of the triangular approximation of the quantum well in AlGaN/GaN heterojunctions is evaluated.

  4. Measurement of the valence band-offset in a PbSe/ZnO heterojunction by x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Li Lin; Qiu Jijun; Weng Binbin; Yuan Zijian; Shi Zhisheng [School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Li Xiaomin; Gan Xiaoyan [State Key Laboratory of High Performance Ceramics and Superfine Microstructures, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Sellers, Ian R. [Deparment of Physics, University of Oklahoma, Norman, Oklahoma 73019 (United States)

    2012-12-24T23:59:59.000Z

    A heterojunction of PbSe/ZnO has been grown by molecular beam epitaxy. X-ray photoelectron spectroscopy was used to directly measure the valence-band offset (VBO) of the heterojunction. The VBO, {Delta}E{sub V}, was determined as 2.51 {+-} 0.05 eV using the Pb 4p{sup 3/2} and Zn 2p{sup 3/2} core levels as a reference. The conduction-band offset, {Delta}E{sub C}, was, therefore, determined to be 0.59 {+-} 0.05 eV based on the above {Delta}E{sub V} value. This analysis indicates that the PbSe/ZnO heterojunction forms a type I (Straddling Gap) heterostructure.

  5. Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion...

    Broader source: Energy.gov (indexed) [DOE]

    More Documents & Publications Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion for Efficient Automotive Waste Heat Recovery Vehicle Technologies Office...

  6. Layered insulator hexagonal boron nitride for surface passivation in quantum dot solar cell

    SciTech Connect (OSTI)

    Shanmugam, Mariyappan; Jain, Nikhil; Jacobs-Gedrim, Robin; Yu, Bin, E-mail: byu@albany.edu [College of Nanoscale Science and Engineering, State University of New York, Albany, New York 12203 (United States)] [College of Nanoscale Science and Engineering, State University of New York, Albany, New York 12203 (United States); Xu, Yang [Institute of Microelectronics and Optoelectronics, Zhejiang University, Hangzhou 310027 (China)] [Institute of Microelectronics and Optoelectronics, Zhejiang University, Hangzhou 310027 (China)

    2013-12-09T23:59:59.000Z

    Single crystalline, two dimensional (2D) layered insulator hexagonal boron nitride (h-BN), is demonstrated as an emerging material candidate for surface passivation on mesoporous TiO{sub 2}. Cadmium selenide (CdSe) quantum dot based bulk heterojunction (BHJ) solar cell employed h-BN passivated TiO{sub 2} as an electron acceptor exhibits photoconversion efficiency ?46% more than BHJ employed unpassivated TiO{sub 2}. Dominant interfacial recombination pathways such as electron capture by TiO{sub 2} surface states and recombination with hole at valence band of CdSe are efficiently controlled by h-BN enabled surface passivation, leading to improved photovoltaic performance. Highly crystalline, confirmed by transmission electron microscopy, dangling bond-free 2D layered h-BN with self-terminated atomic planes, achieved by chemical exfoliation, enables efficient passivation on TiO{sub 2}, allowing electronic transport at TiO{sub 2}/h-BN/CdSe interface with much lower recombination rate compared to an unpassivated TiO{sub 2}/CdSe interface.

  7. The Economic Case for Bulk Energy Storage in Transmission Systems

    E-Print Network [OSTI]

    The Economic Case for Bulk Energy Storage in Transmission Systems with High Percentages to Engineer the Future Electric Energy System #12;#12;The Economic Case for Bulk Energy Storage Economic Case for Bulk Energy Storage in Transmission Sys- tems with High Percentages of Renewable

  8. Towards bulk based preconditioning for quantum dotcomputations

    SciTech Connect (OSTI)

    Dongarra, Jack; Langou, Julien; Tomov, Stanimire; Channing,Andrew; Marques, Osni; Vomel, Christof; Wang, Lin-Wang

    2006-05-25T23:59:59.000Z

    This article describes how to accelerate the convergence of Preconditioned Conjugate Gradient (PCG) type eigensolvers for the computation of several states around the band gap of colloidal quantum dots. Our new approach uses the Hamiltonian from the bulk materials constituent for the quantum dot to design an efficient preconditioner for the folded spectrum PCG method. The technique described shows promising results when applied to CdSe quantum dot model problems. We show a decrease in the number of iteration steps by at least a factor of 4 compared to the previously used diagonal preconditioner.

  9. Role of bulk energy in nuclear multifragmentation

    SciTech Connect (OSTI)

    Buyukcizmeci, N.; Ogul, R. [Department of Physics, University of Selcuk, 42079 Konya (Turkey); Botvina, A. S. [Institute for Nuclear Research, Russian Academy of Sciences, RU-117312 Moscow (Russian Federation); Frankfurt Institute for Advanced Studies, J. W. Goethe University, D-60438 Frankfurt am Main (Germany); Mishustin, I. N. [Frankfurt Institute for Advanced Studies, J. W. Goethe University, D-60438 Frankfurt am Main (Germany); Kurchatov Institute, Russian Research Center, RU-123182 Moscow (Russian Federation)

    2008-03-15T23:59:59.000Z

    Because of thermal expansion and residual interactions, hot nuclear fragments produced in multifragmentation reactions may have nucleon density lower than the equilibrium density of cold nuclei. In terms of a liquid-drop model this effect can be taken into account by reducing the bulk energy of fragments. We study the influence of this change on fragment yields and isotope distributions within the framework of the statistical multifragmentation model. Similarities and differences with previously discussed modifications of symmetry and surface energies of nuclei are analyzed.

  10. Active neutron multiplicity counting of bulk uranium

    SciTech Connect (OSTI)

    Ensslin, N.; Krick, M.S.; Langner, D.G.; Miller, M.C.

    1991-01-01T23:59:59.000Z

    This paper describes a new nondestructive assay technique being developed to assay bulk uranium containing kilogram quantities of {sup 235}U. The new technique uses neutron multiplicity analysis of data collected with a coincidence counter outfitted with AmLi neutron sources. We have calculated the expected neutron multiplicity count rate and assay precision for this technique and will report on its expected performance as a function of detector design characteristics, {sup 235 }U sample mass, AmLi source strength, and source-to-sample coupling. 11 refs., 2 figs., 2 tabs.

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

    SciTech Connect (OSTI)

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

    2014-10-28T23:59:59.000Z

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

  12. Hybrid Solar Cells with Prescribed Nanoscale Morphologies Based on Hyperbranched Semiconductor Nanocrystals

    E-Print Network [OSTI]

    Gur, Ilan; Fromer, Neil A.; Chen, Chih-Ping; Kanaras, Antonios G.; Alivisatos, A. Paul

    2006-01-01T23:59:59.000Z

    bulk heterojunction photovoltaic cells. Mrs Bulletin 30, 37-A. J. Polymer Photovoltaic Cells - Enhanced Efficiencies ViaC[sub 60] heterojunction photovoltaic cell. Applied Physics

  13. DEVELOPMENT OF THE BULK TRITIUM SHIPPING PACKAGING

    SciTech Connect (OSTI)

    Blanton, P.; Eberl, K.

    2008-09-14T23:59:59.000Z

    A new radioactive shipping packaging for transporting bulk quantities of tritium, the Bulk Tritium Shipping Package (BTSP), has been designed for the Department of Energy (DOE) as a replacement for a package designed in the early 1970s. This paper summarizes significant design features and describes how the design satisfies the regulatory safety requirements of the Code of Federal Regulations and the International Atomic Energy Agency. The BTSP design incorporates many improvements over its predecessor by implementing improved testing, handling, and maintenance capabilities, while improving manufacturability and incorporating new engineered materials. This paper also discusses the results from testing of the BTSP to 10 CFR 71 Normal Conditions of Transport and Hypothetical Accident Condition events. The programmatic need of the Department of Energy (DOE) to ship bulk quantities of tritium has been satisfied since the late 1970s by the UC-609 shipping package. The current Certificate of Conformance for the UC-609, USA/9932/B(U) (DOE), will expire in late 2011. Since the UC-609 was not designed to meet current regulatory requirements, it will not be recertified and thereby necessitates a replacement Type B shipping package for continued DOE tritium shipments in the future. A replacement tritium packaging called the Bulk Tritium Shipping Package (BTSP) is currently being designed and tested by Savannah River National Laboratory (SRNL). The BTSP consists of two primary assemblies, an outer Drum Assembly and an inner Containment Vessel Assembly (CV), both designed to mitigate damage and to protect the tritium contents from leaking during the regulatory Hypothetical Accident Condition (HAC) events and during Normal Conditions of Transport (NCT). During transport, the CV rests on a silicone pad within the Drum Liner and is covered with a thermal insulating disk within the insulated Drum Assembly. The BTSP packaging weighs approximately 500 lbs without contents and is 50-1/2 inches high by 24-1/2 inches in outside diameter. With contents the gross weight of the BTSP is 650 lbs. The BTSP is designed for the safe shipment of 150 grams of tritium in a solid or gaseous state. To comply with the federal regulations that govern Type B shipping packages, the BTSP is designed so that it will not lose tritium at a rate greater than the limits stated in 10CFR 71.51 of 10{sup -6} A2 per hour for the 'Normal Conditions of Transport' (NCT) and an A2 in 1 week under 'Hypothetical Accident Conditions' (HAC). Additionally, since the BTSP design incorporates a valve as part of the tritium containment boundary, secondary containment features are incorporated in the CV Lid to protect against gas leakage past the valve as required by 10CFR71.43(e). This secondary containment boundary is designed to provide the same level of containment as the primary containment boundary when subjected to the HAC and NCT criteria.

  14. DEPLOYMENT OF THE BULK TRITIUM SHIPPING PACKAGE

    SciTech Connect (OSTI)

    Blanton, P.

    2013-10-10T23:59:59.000Z

    A new Bulk Tritium Shipping Package (BTSP) was designed by the Savannah River National Laboratory to be a replacement for a package that has been used to ship tritium in a variety of content configurations and forms since the early 1970s. The BTSP was certified by the National Nuclear Safety Administration in 2011 for shipments of up to 150 grams of Tritium. Thirty packages were procured and are being delivered to various DOE sites for operational use. This paper summarizes the design features of the BTSP, as well as associated engineered material improvements. Fabrication challenges encountered during production are discussed as well as fielding requirements. Current approved tritium content forms (gas and tritium hydrides), are reviewed, as well as, a new content, tritium contaminated water on molecular sieves. Issues associated with gas generation will also be discussed.

  15. Rotary adsorbers for continuous bulk separations

    DOE Patents [OSTI]

    Baker, Frederick S. (Oak Ridge, TN)

    2011-11-08T23:59:59.000Z

    A rotary adsorber for continuous bulk separations is disclosed. The rotary adsorber includes an adsorption zone in fluid communication with an influent adsorption fluid stream, and a desorption zone in fluid communication with a desorption fluid stream. The fluid streams may be gas streams or liquid streams. The rotary adsorber includes one or more adsorption blocks including adsorbent structure(s). The adsorbent structure adsorbs the target species that is to be separated from the influent fluid stream. The apparatus includes a rotary wheel for moving each adsorption block through the adsorption zone and the desorption zone. A desorption circuit passes an electrical current through the adsorbent structure in the desorption zone to desorb the species from the adsorbent structure. The adsorbent structure may include porous activated carbon fibers aligned with their longitudinal axis essentially parallel to the flow direction of the desorption fluid stream. The adsorbent structure may be an inherently electrically-conductive honeycomb structure.

  16. CuIn1-xGaxS2 thin film solar cells with ZnxCd1-xS as heterojunction partner Bhaskar Kumar

    E-Print Network [OSTI]

    Sites, James R.

    CuIn1-xGaxS2 thin film solar cells with ZnxCd1-xS as heterojunction partner Bhaskar Kumar 1 , Parag). i:ZnO/Al:ZnO transparent and conducting window bilayer was deposited by RF magnetron sputtering

  17. Photovoltaic devices based on high density boron-doped single-walled carbon nanotube/n-Si heterojunctions

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

    Saini, Viney [Univ. of Arkansas, Little Rock, AR (United States); Li, Zhongrui [Univ. of Arkansas, Little Rock, AR (United States); Bourdo, Shawn [Univ. of Arkansas, Little Rock, AR (United States); Kunets, Vasyl P. [Univ. of Arkansas, Fayetteville, AR (United States); Trigwell, Steven [ASRC Aerospace Corp., Kennedy Space Center, FL (United States); Couraud, Arthur [Univ. of Arkansas, Little Rock, AR (United States) and Ecole d'Ingenieurs de CESI-EIA, La Couronne (France); Rioux, Julien [Univ. of Arkansas, Little Rock, AR (United States) and Ecole d'Ingenieurs du CESI-EIA, La Couronne (France); Boyer, Cyril [Univ. of Arkansas, Little Rock, AR (United States) and Ecole d'Ingenieurs du CESI-EIA, La Couronne (France); Nteziyaremye, Valens [Univ. of Arkansas, Little Rock, AR (United States); Dervishi, Enkeleda [Univ. of Arkansas, Little Rock, AR (United States); Biris, Alexandru R. [National Institute for Research and Development of Isotopic and Molecular Technologies, Cluj-Napoca (Romania); Salamo, Gregory J. [Univ. of Arkansas, Fayetteville, AR (United States); Viswanathan, Tito [Univ. of Arkansas, Little Rock, AR (United States); Biris, Alexandru S. [Univ. of Arkansas, Little Rock, AR (United States)

    2011-01-13T23:59:59.000Z

    A simple and easily processible photovoltaic device has been developed based on borondoped single-walled carbon nanotubes (B-SWNTs) and n-type silicon (n-Si) heterojunctions. The single-walled carbon nanotubes (SWNTs) were substitutionally doped with boron atoms by thermal annealing, in the presence of B2O3. The samples used for these studies were characterized by Raman spectroscopy, thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and x-ray photoelectron spectroscopy (XPS). The fully functional solar cell devices were fabricated by airbrush deposition that generated uniform B-SWNT films on top of the n-Si substrates. The carbon nanotube films acted as exciton-generation sites, charge collection and transportation, while the heterojunctions formed between B-SWNTs and n-Si acted as charge dissociation centers. The current-voltage characteristics in the absence of light and under illumination, as well as optical transmittance spectrum are reported here. It should be noted that the device fabrication process can be made amenable to scalability by depositing direct and uniform films using airbrushing, inkjet printing, or spin-coating techniques.

  18. Strategies for High Thermoelectric zT in Bulk Materials

    Broader source: Energy.gov [DOE]

    Zintl principle in chemistry, complex electronic band structures, and incorporation of nanometer sized particles were used to explore, optimize and improve bulk thermoelectric materials

  19. New nano structure approaches for bulk thermoelectric materials

    E-Print Network [OSTI]

    Kim, Jeonghoon

    2010-01-01T23:59:59.000Z

    in bulk thermoelectric materials", M. Mater. Res. Soc.Thermoelectricity", Materials Reserach Society Symposium,Johnson, D. C. , Eds. Materials Research Society: Boston,

  20. Regulatory Roadmap Workshop for Federal Bulk Transmission Regulations...

    Open Energy Info (EERE)

    Regulatory Roadmapping Pgower's picture Submitted by Pgower(45) Member 7 August, 2014 - 13:19 One-day workshop to review regulatory roadmaps for bulk transmission. Date:...

  1. Bulk Hydrogen Storage - Strategic Directions for Hydrogen Delivery...

    Broader source: Energy.gov (indexed) [DOE]

    Breakout Session - Bulk Hydrogen Storage RD&D Needs Top 6 Categories: Advanced Concepts Advanced Materials Codes & Standards Studies & Analyses Tools & Techniques Demonstration &...

  2. Optimization Online - Real-Time Dispatchability of Bulk Power ...

    E-Print Network [OSTI]

    Wei Wei

    2015-03-16T23:59:59.000Z

    Mar 16, 2015 ... Real-Time Dispatchability of Bulk Power Systems with Volatile Renewable Generations. Wei Wei (wei-wei04 ***at*** mails.tsinghua.edu.cn)

  3. Hetero-junctions of Boron Nitride and Carbon Nanotubes: Synthesis and Characterization

    SciTech Connect (OSTI)

    Yap, Yoke Khin

    2013-03-14T23:59:59.000Z

    Hetero-junctions of boron nitride nanotubes (BNNTs) and carbon nanotubes (CNTs) are expected to have appealing new properties that are not available from pure BNNTs and CNTs. Theoretical studies indicate that BNNT/CNT junctions could be multifunctional and applicable as memory, spintronic, electronic, and photonics devices with tunable band structures. This will lead to energy and material efficient multifunctional devices that will be beneficial to the society. However, experimental realization of BNNT/CNT junctions was hindered by the absent of a common growth technique for BNNTs and CNTs. In fact, the synthesis of BNNTs was very challenging and may involve high temperatures (up to 3000 degree Celsius by laser ablation) and explosive chemicals. During the award period, we have successfully developed a simple chemical vapor deposition (CVD) technique to grow BNNTs at 1100-1200 degree Celsius without using dangerous chemicals. A series of common catalyst have then been identified for the synthesis of BNNTs and CNTs. Both of these breakthroughs have led to our preliminary success in growing two types of BNNT/CNT junctions and two additional new nanostructures: 1) branching BNNT/CNT junctions and 2) co-axial BNNT/CNT junctions, 3) quantum dots functionalized BNNTs (QDs-BNNTs), 4) BNNT/graphene junctions. We have started to understand their structural, compositional, and electronic properties. Latest results indicate that the branching BNNT/CNT junctions and QDs-BNNTs are functional as room-temperature tunneling devices. We have submitted the application of a renewal grant to continue the study of these new energy efficient materials. Finally, this project has also strengthened our collaborations with multiple Department of Energy�s Nanoscale Science Research Centers (NSRCs), including the Center for Nanophase Materials Sciences (CNMS) at Oak Ridge National Laboratory, and the Center for Integrated Nanotechnologies (CINTs) at Sandia National Laboratories and Los Alamos National Laboratory. Results obtained during the current funding period have led to the publication of twelve peer reviewed articles, three review papers, two book and one encyclopedia chapters, and thirty eight conference/seminar presentation. One US provisional patent and one international patent have also been filed.

  4. Improving Bulk Microphysics Parameterizations in Simulations of Aerosol Effects

    SciTech Connect (OSTI)

    Wang, Yuan; Fan, Jiwen; Zhang, Renyi; Leung, Lai-Yung R.; Franklin, Charmaine N.

    2013-06-05T23:59:59.000Z

    To improve the microphysical parameterizations for simulations of the aerosol indirect effect (AIE) in regional and global climate models, a double-moment bulk microphysical scheme presently implemented in the Weather Research and Forecasting (WRF) model is modified and the results are compared against atmospheric observations and simulations produced by a spectral bin microphysical scheme (SBM). Rather than using prescribed aerosols as in the original bulk scheme (Bulk-OR), a prognostic doublemoment aerosol representation is introduced to predict both the aerosol number concentration and mass mixing ratio (Bulk-2M). The impacts of the parameterizations of diffusional growth and autoconversion and the selection of the embryonic raindrop radius on the performance of the bulk microphysical scheme are also evaluated. Sensitivity modeling experiments are performed for two distinct cloud regimes, maritime warm stratocumulus clouds (SC) over southeast Pacific Ocean from the VOCALS project and continental deep convective clouds (DCC) in the southeast of China from the Department of Energy/ARM Mobile Facility (DOE/AMF) - China field campaign. The results from Bulk-2M exhibit a much better agreement in the cloud number concentration and effective droplet radius in both the SC and DCC cases with those from SBM and field measurements than those from Bulk-OR. In the SC case particularly, Bulk-2M reproduces the observed drizzle precipitation, which is largely inhibited in Bulk-OR. Bulk-2M predicts enhanced precipitation and invigorated convection with increased aerosol loading in the DCC case, consistent with the SBM simulation, while Bulk-OR predicts the opposite behaviors. Sensitivity experiments using four different types of autoconversion schemes reveal that the autoconversion parameterization is crucial in determining the raindrop number, mass concentration, and drizzle formation for warm 2 stratocumulus clouds. An embryonic raindrop size of 40 ?m is determined as a more realistic setting in the autoconversion parameterization. The saturation adjustment employed in calculating condensation/evaporation in the bulk scheme is identified as the main factor responsible for the large discrepancies in predicting cloud water in the SC case, suggesting that an explicit calculation of diffusion growth with predicted supersaturation is necessary for further improvements of the bulk microphysics scheme. Lastly, a larger rain evaporation rate below cloud is found in the bulk scheme in comparison to the SBM simulation, which could contribute to a lower surface precipitation in the bulk scheme.

  5. Role of Cavitation in Bulk Ultrasound Ablation: A Histologic Study

    E-Print Network [OSTI]

    Mast, T. Douglas

    Role of Cavitation in Bulk Ultrasound Ablation: A Histologic Study Chandra Priya Karunakaran, Mark of Cincinnati, Cincinnati, Ohio Abstract. The role of cavitation in bulk ultrasound ablation has been evaluated-ablate probe at 31 W/cm2 for 20 minutes under normal and elevated ambient pressures. A 1 MHz passive cavitation

  6. Carbon nanotubes grown on bulk materials and methods for fabrication

    DOE Patents [OSTI]

    Menchhofer, Paul A. (Clinton, TN); Montgomery, Frederick C. (Oak Ridge, TN); Baker, Frederick S. (Oak Ridge, TN)

    2011-11-08T23:59:59.000Z

    Disclosed are structures formed as bulk support media having carbon nanotubes formed therewith. The bulk support media may comprise fibers or particles and the fibers or particles may be formed from such materials as quartz, carbon, or activated carbon. Metal catalyst species are formed adjacent the surfaces of the bulk support material, and carbon nanotubes are grown adjacent the surfaces of the metal catalyst species. Methods employ metal salt solutions that may comprise iron salts such as iron chloride, aluminum salts such as aluminum chloride, or nickel salts such as nickel chloride. Carbon nanotubes may be separated from the carbon-based bulk support media and the metal catalyst species by using concentrated acids to oxidize the carbon-based bulk support media and the metal catalyst species.

  7. Bulk Vitrification Castable Refractory Block Protection Study

    SciTech Connect (OSTI)

    Hrma, Pavel R.; Bagaasen, Larry M.; Beck, Andrew E.; Brouns, Thomas M.; Caldwell, Dustin D.; Elliott, Michael L.; Matyas, Josef; Minister, Kevin BC; Schweiger, Michael J.; Strachan, Denis M.; Tinsley, Bronnie P.; Hollenberg, Glenn W.

    2005-05-01T23:59:59.000Z

    Bulk vitrification (BV) was selected for a pilot-scale test and demonstration facility for supplemental treatment to accelerate the cleanup of low-activity waste (LAW) at the Hanford U.S. DOE Site. During engineering-scale (ES) tests, a small fraction of radioactive Tc (and Re, its nonradioactive surrogate) were transferred out of the LAW glass feed and molten LAW glass, and deposited on the surface and within the pores of the castable refractory block (CRB). Laboratory experiments were undertaken to understand the mechanisms of the transport Tc/Re into the CRB during vitrification and to evaluate various means of CRB protection against the deposition of leachable Tc/Re. The tests used Re as a chemical surrogate for Tc. The tests with the baseline CRB showed that the molten LAW penetrates into CRB pores before it converts to glass, leaving deposits of sulfates and chlorides when the nitrate components decompose. Na2O from the LAW reacts with the CRB to create a durable glass phase that may contain Tc/Re. Limited data from a single CRB sample taken from an ES experiment indicate that, while a fraction of Tc/Re is present in the CRB in a readily leachable form, most of the Tc/Re deposited in the refractory is retained in the form of a durable glass phase. In addition, the molten salts from the LAW, mainly sulfates, chlorides, and nitrates, begin to evaporate from BV feeds at temperatures below 800 C and condense on solid surfaces at temperatures below 530 C. Three approaches aimed at reducing or preventing the deposition of soluble Tc/Re within the CRB were proposed: metal lining, sealing the CRB surface with a glaze, and lining the CRB with ceramic tiles. Metal liners were deemed unsuitable because evaluations showed that they can cause unacceptable distortions of the electric field in the BV system. Sodium silicate and a low-alkali borosilicate glaze were selected for testing. The glazes slowed down molten salt condensate penetration, but did little to reduce the penetration of molten salt. Out of several refractory tile candidates, only greystone and fused-cast alumina-zirconia-silica (AZS) refractory remained intact and well bonded to the CRB after firing to 1000 C. The deformation of the refractory-tile composite was avoided by prefiring the greystone tile to 800 C. Condensed vapors did not penetrate the tiles, but Re salts condensed on their surface. Refractory corrosion tests indicated that a 0.25-inch-thick greystone tile would not corrode during a BV melt. Tiles can reduce both vapor penetration and molten salt penetration, but vapor deposition above the melt line will occur even on tiles. The Tc/Re transport scenario was outlined as follows. At temperatures below 700 C, molten ionic salt (MIS) that includes all the Tc/Re penetrates, by capillarity, from the feed into the CRB open porosity. At approximately 750 C, the MIS decomposes through the loss of NOx, leaving mainly sulfate and chloride salts. The Na2O formed in the decomposition of the nitrates reacts with insoluble grains in the feed and with the aluminosilicates in the CRB to form more viscous liquids that reduce further liquid penetration into the CRB. At 800 to 1000 C, a continuous glass phase traps the remains of the MIS in the form of inclusions in the bulk glass melt. At 1000 to 1200 C, the salt inclusions in the glass slowly dissolve but also rise to the surface. The Tc/Re salts also evaporate from the free surface of the glass melt that is rapidly renewed by convective currents. The vapors condense on cooler surfaces in the upper portion of the CRB, the box lid, and the off-gas system.

  8. Silicon bulk micromachined hybrid dimensional artifact.

    SciTech Connect (OSTI)

    Claudet, Andre A.; Tran, Hy D.; Bauer, Todd Marks; Shilling, Katherine Meghan; Oliver, Andrew David

    2010-03-01T23:59:59.000Z

    A mesoscale dimensional artifact based on silicon bulk micromachining fabrication has been developed and manufactured with the intention of evaluating the artifact both on a high precision coordinate measuring machine (CMM) and video-probe based measuring systems. This hybrid artifact has features that can be located by both a touch probe and a video probe system with a k=2 uncertainty of 0.4 {micro}m, more than twice as good as a glass reference artifact. We also present evidence that this uncertainty could be lowered to as little as 50 nm (k=2). While video-probe based systems are commonly used to inspect mesoscale mechanical components, a video-probe system's certified accuracy is generally much worse than its repeatability. To solve this problem, an artifact has been developed which can be calibrated using a commercially available high-accuracy tactile system and then be used to calibrate typical production vision-based measurement systems. This allows for error mapping to a higher degree of accuracy than is possible with a glass reference artifact. Details of the designed features and manufacturing process of the hybrid dimensional artifact are given and a comparison of the designed features to the measured features of the manufactured artifact is presented and discussed. Measurement results from vision and touch probe systems are compared and evaluated to determine the capability of the manufactured artifact to serve as a calibration tool for video-probe systems. An uncertainty analysis for calibration of the artifact using a CMM is presented.

  9. Rectification properties of n-type nanocrystalline diamond heterojunctions to p-type silicon carbide at high temperatures

    SciTech Connect (OSTI)

    Goto, Masaki; Amano, Ryo; Shimoda, Naotaka [Graduate School of Automotive Science, Kyushu University, Nishiku, Fukuoka 819-0395 (Japan); Kato, Yoshimine, E-mail: yoshimine.kato@zaiko.kyushu-u.ac.jp [Department of Materials Science and Engineering, Kyushu University, Nishiku, Fukuoka 819-0395 (Japan); Teii, Kungen [Department of Applied Science for Electronics and Materials, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

    2014-04-14T23:59:59.000Z

    Highly rectifying heterojunctions of n-type nanocrystalline diamond (NCD) films to p-type 4H-SiC substrates are fabricated to develop p-n junction diodes operable at high temperatures. In reverse bias condition, a potential barrier for holes at the interface prevents the injection of reverse leakage current from the NCD into the SiC and achieves the high rectification ratios of the order of 10{sup 7} at room temperature and 10{sup 4} even at 570?K. The mechanism of the forward current injection is described with the upward shift of the defect energy levels in the NCD to the conduction band of the SiC by forward biasing. The forward current shows different behavior from typical SiC Schottky diodes at high temperatures.

  10. Physics of gate leakage current in N-polar InAlN/GaN heterojunction field effect transistors

    SciTech Connect (OSTI)

    Goswami, Arunesh; Trew, Robert J.; Bilbro, Griff L. [ECE Department, Box 7911, North Carolina State University, Raleigh, North Carolina 27695-7911 (United States)

    2014-10-28T23:59:59.000Z

    A physics based model of the gate leakage current in N-polar InAlN/GaN heterojunction field effect transistors is demonstrated. The model is based on the space charge limited current flow dominated by the effects of deep traps in the InAlN surface layer. The model predicts accurately the gate-leakage measurement data of the N-polar InAlN/GaN device with InAlN cap layer. In the pinch-off state, the gate leakage current conduction through the surface of the device in the drain access region dominates the current flow through the two dimensional electron gas channel. One deep trap level and two levels of shallow traps are extracted by fitting the model results with measurement data.

  11. Running heading: Bulk density of a clayey subsoil Increase in the bulk density of a Grey Clay subsoil by

    E-Print Network [OSTI]

    Boyer, Edmond

    1 Running heading: Bulk density of a clayey subsoil Increase in the bulk density of a Grey Clay of the prisms were coated by material similar in composition to the topsoil and separated from as the profile dries over summer leading to widening of cracks between prismatic peds, (2) infilling of cracks

  12. Neutrino mass, bulk majoron and neutrinoless double beta decay

    E-Print Network [OSTI]

    R. N. Mohapatra; A. Perez-Lorenzana; C. A. de S. Pires

    2000-08-15T23:59:59.000Z

    A new economical model for neutrino masses is proposed in the context of brane bulk scenarios for particle physics, where global B-L symmetry of the standard model is broken spontaneously by a gauge singlet Higgs field in the bulk. This leads to a bulk majoron whose KK excitations may make it visible if neutrinoless double beta decay if the string scale is close to a TeV. It also leads to neutron-anti-neutron oscillation process with transition times which can be in the range accessible to proposed experiments.

  13. Brane-Bulk energy exchange and agegraphic dark energy

    E-Print Network [OSTI]

    Ahmad Sheykhi

    2010-02-06T23:59:59.000Z

    We consider the agegraphic models of dark energy in a braneworld scenario with brane-bulk energy exchange. We assume that the adiabatic equation for the dark matter is satisfied while it is violated for the agegraphic dark energy due to the energy exchange between the brane and the bulk. Our study shows that with the brane-bulk interaction, the equation of state parameter of agegraphic dark energy on the brane, $w_D$, can have a transition from normal state where $w_D >-1 $ to the phantom regime where $w_D energy always satisfies $w^{\\mathrm{eff}}_D\\geq-1$.

  14. Fabrication and characterization of n-type aluminum-boron co-doped ZnO on p-type silicon (n-AZB/p-Si) heterojunction diodes

    SciTech Connect (OSTI)

    Kumar, Vinod, E-mail: vinod.phy@gmail.com [Department of Physics, University of the Free State, Bloemfontein ZA-9300 (South Africa); Singh, Neetu [Department of Electronic Science, University of Delhi South Campus, New Delhi 110 021 (India); Department of Electronics, Keshav Mahavidyalaya, University of Delhi 110 034 (India); Kapoor, Avinashi [Department of Electronic Science, University of Delhi South Campus, New Delhi 110 021 (India); Ntwaeaborwa, Odireleng M.; Swart, Hendrik C. [Department of Physics, University of the Free State, Bloemfontein ZA-9300 (South Africa)

    2013-11-15T23:59:59.000Z

    Graphical abstract: - Highlights: • n-AZB/p-Si heterojunction diodes were formed. • n-AZB/p-Si diode annealed at 700 °C showed best rectifying behavior. • Zn{sub 2}SiO{sub 4} was formed at 800 °C. • n and ?{sub b} were estimated to be 1.63 and 0.4 eV, respectively, at 700 °C. • Tailoring of BG was attributed to annealing induced stresses in the films. - Abstract: In this paper, the growth of n-type aluminum boron co-doped ZnO (n-AZB) on a p-type silicon (p-Si) substrate by sol–gel method using spin coating technique is reported. The n-AZB/p-Si heterojunctions were annealed at different temperatures ranging from 400 to 800 °C. The crystallite size of the AZB nanostructures was found to vary from 28 to 38 nm with the variation in annealing temperature. The band gap of the AZB decreased from 3.29 to 3.27 eV, with increasing annealing temperature from 400 to 700 °C and increased to 3.30 eV at 800 °C probably due to the formation of Zn{sub 2}SiO{sub 4} at the interface. The band gap variation is explained in terms of annealing induced stress in the AZB. The n-AZB/p-Si heterojunction exhibited diode behavior. The best rectifying behavior was exhibited at 700 °C.

  15. Structural and economic analysis of capesize bulk carriers

    E-Print Network [OSTI]

    Hadjiyiannis, Nicholas

    2010-01-01T23:59:59.000Z

    Structural failures of bulk carriers continue to account for the loss of many lives every year. Capes are particularly vulnerable to cracking because of their large length, their trade in high density cargos, and the high ...

  16. Stresses resulting from compression of bulk cotton lint fibers

    E-Print Network [OSTI]

    Chimbombi, Ezekiel Maswe

    1998-01-01T23:59:59.000Z

    The modulus of elasticity, Poisson's ratio and shear modulus of bulk cotton lint fibers were determined. The cotton lint was compressed in an MTS machine to a predetermined density, and the resilient forces induced by the cotton lint after being...

  17. A bulk-flow model of angled injection Lomakin bearings

    E-Print Network [OSTI]

    Soulas, Thomas Antoine Theo

    2001-01-01T23:59:59.000Z

    A bulk-flow model for determination of the leakage and dynamic force characteristics of angled injection Lomakin bearings is presented. Zeroth- and first-order equations describe the equilibrium flow for a centered bearing and the perturbed flow...

  18. Mechanical Properties of Bulk Metallic Glasses and Composites

    E-Print Network [OSTI]

    Lee, M.L.

    We have studied the mechanical properties of monolithic bulk metallic glasses and composite in the La based alloys. La???yAl??(Cu, Ni)y (y=24 to 32) alloy systems was used to cast the ...

  19. Compositional ordering and stability in nanostructured, bulk thermoelectric alloys.

    SciTech Connect (OSTI)

    Hekmaty, Michelle A.; Faleev, S.; Medlin, Douglas L.; Leonard, F.; Lensch-Falk, J.; Sharma, Peter Anand; Sugar, J. D.

    2009-09-01T23:59:59.000Z

    Thermoelectric materials have many applications in the conversion of thermal energy to electrical power and in solid-state cooling. One route to improving thermoelectric energy conversion efficiency in bulk material is to embed nanoscale inclusions. This report summarize key results from a recently completed LDRD project exploring the science underpinning the formation and stability of nanostructures in bulk thermoelectric and the quantitative relationships between such structures and thermoelectric properties.

  20. Costs, Savings and Financing Bulk Tanks on Texas Dairy Farms.

    E-Print Network [OSTI]

    Moore, Donald S.; Stelly, Randall; Parker, Cecil A.

    1958-01-01T23:59:59.000Z

    \\ BULLETIN 904 MAY 1958 .t(. :a ,s - / cwdh\\@ Costs, Savi~gs;.itd Financing Bulk Tanks on Texas Dairy Farms . ?. I I 1 i I I ! ,:ravings in hauling - 10 cents I \\ \\ 1 \\ savings in hauling - 15 cents -----------____--- 'savings... in hauling - 20 cents Annual production, 1,000 pounds Estimated number of years required for savings from a bulk tank to equal additional costs at different levels of production and savings in hauling costs. TEXAS AGRICULTURAL EXPERIMEN'T STATION R. D...

  1. RAPID/BulkTransmission/Texas | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaskiRAPID/BulkTransmission/Texas < RAPID‎ | BulkTransmission

  2. RAPID/BulkTransmission/Water Quality | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaskiRAPID/BulkTransmission/Texas <RAPID/BulkTransmission/Water

  3. RAPID/BulkTransmission/Wyoming | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaskiRAPID/BulkTransmission/TexasRAPID/BulkTransmission/Wyoming <

  4. Finsler geometric perspective on the bulk flow in the universe

    E-Print Network [OSTI]

    Zhe Chang; Ming-Hua Li; Sai Wang

    2013-03-07T23:59:59.000Z

    Astronomical observations showed that there may exist a bulk flow with peculiar velocities in the universe, which contradicts with the (\\Lambda)CDM model. The bulk flow reveals that the observational universe is anisotropic at large scales. In fact, a more reliable observation on the anisotropy of spacetime comes from the CMB power spectra. The WMAP and Planck satellites both show that there is a hemispherical power asymmetry at large-angular scales. In this paper, we propose a "wind" scenario to the bulk flow (or the anisotropy of spacetime). Under the influence of the "wind", the spacetime metric could become a Finsler structure. By resolving the null geodesic equation, we obtain the modified luminosity distance, which has a dipolar form at the leading order. Thus, the "wind" describes well the bulk flow. In addition, we perform a least-(\\chi^2) fit to the data of type Ia supernovae (SNe Ia) in the Union2.1 compilation. The peculiar velocity of the bulk flow has an upper limit (v_{bulk}\\lesssim 4000 \\rm{km/s}), which is compatible with all the existing observational values.

  5. Cosmic No Hair for Braneworlds with a Bulk Dilaton Field

    E-Print Network [OSTI]

    James E. Lidsey; David Seery

    2005-09-22T23:59:59.000Z

    Braneworld cosmology supported by a bulk scalar field with an exponential potential is developed. A general class of separable backgrounds for both single and two-brane systems is derived, where the bulk metric components are given by products of world-volume and bulk coordinates and the world-volumes represent any anisotropic and inhomogeneous solution to an effective four-dimensional Brans-Dicke theory of gravity. We deduce a cosmic no hair theorem for all ever expanding, spatially homogeneous Bianchi world-volumes and find that the spatially flat and isotropic inflationary scaling solution represents a late-time attractor when the bulk potential is sufficiently flat. The dependence of this result on the separable nature of the bulk metric is investigated by applying the techniques of Hamilton-Jacobi theory to five-dimensional Einstein gravity. We employ the spatial gradient expansion method to determine the asymptotic form of the bulk metric up to third-order in spatial gradients. It is found that the condition for the separable form of the metric to represent the attractor of the system is precisely the same as that for the four-dimensional world-volume to isotropize. We also derive the fourth-order contribution to the Hamilton-Jacobi generating functional. Finally, we conclude by placing our results within the context of the holographic approach to braneworld cosmology.

  6. The Role of Surface Chemistry and Bulk Properties on the Cycling...

    Broader source: Energy.gov (indexed) [DOE]

    The Role of Surface Chemistry and Bulk Properties on the Cycling and Rate Capability of Lithium Positive Electrode Materials The Role of Surface Chemistry and Bulk Properties on...

  7. Bulk emission of scalars by a rotating black hole

    E-Print Network [OSTI]

    M. Casals; S. R. Dolan; P. Kanti; E. Winstanley

    2008-07-17T23:59:59.000Z

    We study in detail the scalar-field Hawking radiation emitted into the bulk by a higher-dimensional, rotating black hole. We numerically compute the angular eigenvalues, and solve the radial equation of motion in order to find transmission factors. The latter are found to be enhanced by the angular momentum of the black hole, and to exhibit the well-known effect of superradiance. The corresponding power spectra for scalar fields show an enhancement with the number of dimensions, as in the non-rotating case. We compute the total mass loss rate of the black hole for a variety of black-hole angular momenta and bulk dimensions, and find that, in all cases, the bulk emission remains significantly smaller than the brane emission. The angular-momentum loss rate is also computed and found to have a smaller value in the bulk than on the brane. We present accurate bulk-to-brane emission ratios for a range of scenarios.

  8. Effect of Mg ionization efficiency on performance of Npn AlGaN/GaN heterojunction bipolar transistors

    SciTech Connect (OSTI)

    MONIER,C.; PEARTON,S.J.; CHANG,PING-CHIH; BACA,ALBERT G.

    2000-03-10T23:59:59.000Z

    A drift-diffusion transport model has been used to examine the performance capabilities of AlGaN/GaN Npn heterojunction bipolar transistors (HBTs). The Gummel plot from the first GaN-based HBT structure recently demonstrated is adjusted with simulation by using experimental mobility and lifetime reported in the literature. Numerical results have been explored to study the effect of the p-type Mg doping and its incomplete ionization in the base. The high base resistance induced by the deep acceptor level is found to be the cause of limiting current gain values. Increasing the operating temperature of the device activates more carriers in the base. An improvement of the simulated current gain by a factor of 2 to 4 between 25 and 300 C agrees well with the reported experimental results. A preliminary analysis of high frequency characteristics indicates substantial progress of predicted rf performances by operating the device at higher temperature due to a reduced extrinsic base resistivity.

  9. Simulation of Npn and Pnp AlGaN/GaN heterojunction bipolar transistors performances: Limiting factors and optimum design

    SciTech Connect (OSTI)

    MONIER,C.; REN,F.; HAN,JUNG; CHANG,PING-CHIH; SHUL,RANDY J.; LEE,K.P.; ZHANG,A.P.; BACA,ALBERT G.; PEARTON,S.J.

    2000-04-25T23:59:59.000Z

    The performance capabilities of Npn and Pnp AlGaN/GaN heterojunction bipolar transistors have been investigated by using a drift-diffusion transport model. Numerical results have been employed to study the effect of the p-type Mg doping and its incomplete ionization on device performance. The high base resistance induced by the deep acceptor level is found to be the cause of limited current gain values for Npn devices. Several computation approaches have been considered to improve their performance. Reasonable improvement of the DC current gain {beta} is observed by realistically reducing the base thickness in accordance with processing limitations. Base transport enhancement is also predicted by the introduction of a quasi-electric field in the base. The impact of the base resistivity on high-frequency characteristics is investigated for Npn AlGaN/GaN devices. Optimized predictions with maximum oscillation frequency value as high as f{sub MAX} = 20 GHz and a unilateral power gain--U = 25 dB make this bipolar GaN-based technology compatible with communication applications. Simulation results reveal that the restricted amount of free carriers from the p-doped emitter limits Pnp's DC performances operating in common emitter configuration. A preliminary analysis of r.f. characteristics for the Pnp counterpart indicates limited performance mainly caused by the degraded hole mobility.

  10. Quasiparticle theory of shear and bulk viscosities of hadronic matter

    SciTech Connect (OSTI)

    Chakraborty, P.; Kapusta, J. I. [School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

    2011-01-15T23:59:59.000Z

    A theoretical framework for the calculation of shear and bulk viscosities of hadronic matter at finite temperature is presented. The framework is based on the quasiparticle picture. It allows for an arbitrary number of hadron species with pointlike interactions, and allows for both elastic and inelastic collisions. Detailed balance is ensured. The particles have temperature-dependent masses arising from mean-field or potential effects, which maintains self-consistency between the equation of state and the transport coefficients. As an example, we calculate the shear and bulk viscosity in the linear {sigma} model. The ratio of shear viscosity to entropy density shows a minimum in the vicinity of a rapid crossover transition, whereas the ratio of bulk viscosity to entropy density shows a maximum.

  11. Properties of Bulk Sintered Silver As a Function of Porosity

    SciTech Connect (OSTI)

    Wereszczak, Andrew A [ORNL; Vuono, Daniel J [ORNL; Wang, Hsin [ORNL; Ferber, Mattison K [ORNL; Liang, Zhenxian [ORNL

    2012-06-01T23:59:59.000Z

    This report summarizes a study where various properties of bulk-sintered silver were investigated over a range of porosity. This work was conducted within the National Transportation Research Center's Power Device Packaging project that is part of the DOE Vehicle Technologies Advanced Power Electronics and Electric Motors Program. Sintered silver, as an interconnect material in power electronics, inherently has porosity in its produced structure because of the way it is made. Therefore, interest existed in this study to examine if that porosity affected electrical properties, thermal properties, and mechanical properties because any dependencies could affect the intended function (e.g., thermal transfer, mechanical stress relief, etc.) or reliability of that interconnect layer and alter how its performance is modeled. Disks of bulk-sintered silver were fabricated using different starting silver pastes and different sintering conditions to promote different amounts of porosity. Test coupons were harvested out of the disks to measure electrical resistivity and electrical conductivity, thermal conductivity, coefficient of thermal expansion, elastic modulus, Poisson's ratio, and yield stress. The authors fully recognize that the microstructure of processed bulk silver coupons may indeed not be identical to the microstructure produced in thin (20-50 microns) layers of sintered silver. However, measuring these same properties with such a thin actual structure is very difficult, requires very specialized specimen preparation and unique testing instrumentation, is expensive, and has experimental shortfalls of its own, so the authors concluded that the herein measured responses using processed bulk sintered silver coupons would be sufficient to determine acceptable values of those properties. Almost all the investigated properties of bulk sintered silver changed with porosity content within a range of 3-38% porosity. Electrical resistivity, electrical conductivity, thermal conductivity, elastic modulus, Poisson's ratio, and yield stress all depended on the porosity content in bulk-sintered silver. The only investigated property that was independent of porosity in that range was coefficient of thermal expansion.

  12. Bulk-edge correspondence for two-dimensional topological insulators

    E-Print Network [OSTI]

    G. M. Graf; M. Porta

    2013-03-19T23:59:59.000Z

    Topological insulators can be characterized alternatively in terms of bulk or edge properties. We prove the equivalence between the two descriptions for two-dimensional solids in the single-particle picture. We give a new formulation of the $\\mathbb{Z}_{2}$-invariant, which allows for a bulk index not relying on a (two-dimensional) Brillouin zone. When available though, that index is shown to agree with known formulations. The method also applies to integer quantum Hall systems. We discuss a further variant of the correspondence, based on scattering theory.

  13. Nano-crystalline p-ZnGa{sub 2}Te{sub 4}/n-Si as a new heterojunction diode

    SciTech Connect (OSTI)

    Sakr, G.B. [Nano-Science Lab., Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt)] [Nano-Science Lab., Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt); Fouad, S.S. [Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt)] [Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt); Yahia, I.S., E-mail: dr_isyahia@yahoo.com [Nano-Science Lab., Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt); Semicondcutor Lab., Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt); Department of Physics, Faculty of Science, King Khalid University, P.O. Box 9004, Abha (Saudi Arabia); Abdel Basset, D.M. [Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt)] [Department of Physics, Faculty of Education, Ain Shams University, Roxy, Cairo (Egypt); Yakuphanoglu, F. [Physics Department, Faculty of Science and Arts, Firat University, Elazig (Turkey)] [Physics Department, Faculty of Science and Arts, Firat University, Elazig (Turkey)

    2013-02-15T23:59:59.000Z

    Graphical abstract: Display Omitted Highlights: ? ZnGa{sub 2}Te{sub 4}/Si thin film was prepared by thermal evaporation technique. ? XRD and AFM graphs support the nano-crystalline of the studied device. ? Dark current–voltage characteristics of the heterojunction diode were investigated. ? Electrical parameters and conduction mechanism were determined. ? Conduction mechanisms were controlled by TE, SCLC and TCLC. -- Abstract: In this communication, ZnGa{sub 2}Te{sub 4} thin film was prepared by thermal evaporation technique on n-Si substrate. P-ZnGa{sub 2}Te{sub 4}/n-Si heterojunction diode was fabricated. The structure of ZnGa{sub 2}Te{sub 4} thin film was checked by XRD pattern and confirmed by AFM micrographs. The dark current–voltage characteristics of the heterojunction diode were investigated to determine the electrical parameters and conduction mechanism as a function of forward and reverse biasing conditions in the range (?10 V to 10 V) at temperature interval (303–423 K). The conduction mechanism was controlled by thermionic emission, space charge limited (SCLC) and trap-charge limited current (TCLC) mechanisms. The basic parameters such as the series resistance R{sub s}, the shunt resistance R{sub sh}, the ideality factor n and the barrier height ?{sub b} of the diode, the total density of trap states N{sub 0} and the exponential trapping distribution P{sub o} were determined. The obtained results showed that ZnGa{sub 2}Te{sub 4} is a good candidate for the applications of electronic devices.

  14. Permanent magnet with MgB{sub 2} bulk superconductor

    SciTech Connect (OSTI)

    Yamamoto, Akiyasu, E-mail: yamamoto@appchem.t.u-tokyo.ac.jp [The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan); JST-PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Ishihara, Atsushi; Tomita, Masaru [Railway Technical Research Institute, 2-8-38 Hikari, Kokubunji, Tokyo 185-8540 (Japan); Kishio, Kohji [The University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-8656 (Japan)

    2014-07-21T23:59:59.000Z

    Superconductors with persistent zero-resistance currents serve as permanent magnets for high-field applications requiring a strong and stable magnetic field, such as magnetic resonance imaging. The recent global helium shortage has quickened research into high-temperature superconductors (HTSs)—materials that can be used without conventional liquid-helium cooling to 4.2?K. Herein, we demonstrate that 40-K-class metallic HTS magnesium diboride (MgB{sub 2}) makes an excellent permanent bulk magnet, maintaining 3?T at 20?K for 1 week with an extremely high stability (<0.1 ppm/h). The magnetic field trapped in this magnet is uniformly distributed, as for single-crystalline neodymium-iron-boron. Magnetic hysteresis loop of the MgB{sub 2} permanent bulk magnet was determined. Because MgB{sub 2} is a simple-binary-line compound that does not contain rare-earth metals, polycrystalline bulk material can be industrially fabricated at low cost and with high yield to serve as strong magnets that are compatible with conventional compact cryocoolers, making MgB{sub 2} bulks promising for the next generation of Tesla-class permanent-magnet applications.

  15. Security-Constrained Adequacy Evaluation of Bulk Power System Reliability

    E-Print Network [OSTI]

    Security-Constrained Adequacy Evaluation of Bulk Power System Reliability Fang Yang, Student Member contingency selection, (b) effects analysis, and (c) reliability index computation. Effects analysis and reliability index computations. The methodology is demonstrated with the IEEE reliability test system. Index

  16. Stress tensor and bulk viscosity in relativistic nuclear collisions

    E-Print Network [OSTI]

    Fries, Rainer J.; Mueller, Berndt; Schaefer, Andreas.

    2008-01-01T23:59:59.000Z

    We discuss the influence of different initial conditions for the stress tensor and the effect of bulk viscosity on the expansion and cooling of the fireball created in relativistic heavy ion collisions. In particular, we explore the evolution...however, it does not significantly increase the entropy produced....

  17. Development of Bulk Nanocrystalline Cemented Tungsten Carbide for Industrial Applicaitons

    SciTech Connect (OSTI)

    Z. Zak Fang, H. Y. Sohn

    2009-03-10T23:59:59.000Z

    This report contains detailed information of the research program entitled "Development of Bulk Nanocrystalline Cemented Tungsten Carbide Materials for Industrial Applications". The report include the processes that were developed for producing nanosized WC/Co composite powders, and an ultrahigh pressure rapid hot consolidation process for sintering of nanosized powders. The mechanical properties of consolidated materials using the nanosized powders are also reported.

  18. Computing hypersurfaces which minimize surface energy plus bulk energy

    E-Print Network [OSTI]

    Sullivan, John M.

    the energy of an interface surface, where the energy might be just area, or could have a density dependent curvature associated to the energy density ; if 1 so that the surface energy is just area[Page 17] Computing hypersurfaces which minimize surface energy plus bulk energy John M. Sullivan

  19. Heavy-ion broad-beam and microprobe studies of single-event upsets in 0.20 um SiGe heterojunction bipolar transistors and circuits.

    SciTech Connect (OSTI)

    Fritz, Karl (Mayo Foundation, Rochester, MN); Irwin, Timothy J. (Jackson & Tull Chartered Engineers, Washington, DC); Niu, Guofu (Auburn University, Auburn, AL); Fodness, Bryan (SGT, Inc., Greenbelt, MD); Carts, Martin A. (Raytheon ITSS, Greenbelt, MD); Marshall, Paul W. (Brookneal, VA); Reed, Robert A. (NASA/GSFC, Greenbelt, MD); Gilbert, Barry (Mayo Foundation, Rochester, MN); Randall, Barbara (Mayo Foundation, Rochester, MN); Prairie, Jason (Mayo Foundation, Rochester, MN); Riggs, Pam (Mayo Foundation, Rochester, MN); Pickel, James C. (PR& T, Inc., Fallbrook, CA); LaBel, Kenneth (NASA/GSFC, Greenbelt, MD); Cressler, John D. (Georgia Institute of Technology, Atlanta, GA); Krithivasan, Ramkumar (Georgia Institute of Technology, Atlanta, GA); Dodd, Paul Emerson; Vizkelethy, Gyorgy

    2003-09-01T23:59:59.000Z

    Combining broad-beam circuit level single-event upset (SEU) response with heavy ion microprobe charge collection measurements on single silicon-germanium heterojunction bipolar transistors improves understanding of the charge collection mechanisms responsible for SEU response of digital SiGe HBT technology. This new understanding of the SEU mechanisms shows that the right rectangular parallele-piped model for the sensitive volume is not applicable to this technology. A new first-order physical model is proposed and calibrated with moderate success.

  20. A COMPREHENSIVE TECHNICAL REVIEW OF THE DEMONSTRATION BULK VITRIFICATION SYSTEM

    SciTech Connect (OSTI)

    SCHAUS, P.S.

    2006-09-29T23:59:59.000Z

    In May 2006, CH2M Hill Hanford Group, Inc. chartered an Expert Review Panel (ERP) to review the current status of the Demonstration Bulk Vitrification System (DBVS). It is the consensus of the ERP that bulk vitrification is a technology that requires further development and evaluation to determine its potential for meeting the Hanford waste stabilization mission. No fatal flaws (issues that would jeopardize the overall DBVS mission that cannot be mitigated) were found, given the current state of the project. However, a number of technical issues were found that could significantly affect the project's ability to meet its overall mission as stated in the project ''Justification of Mission Need'' document, if not satisfactorily resolved. The ERP recognizes that the project has changed from an accelerated schedule demonstration project to a formally chartered project that must be in full compliance with DOE 413.3 requirements. The perspective of the ERP presented herein, is measured against the formally chartered project as stated in the approved Justification of Mission Need document. A justification of Mission Need document was approved in July 2006 which defined the objectives for the DBVS Project. In this document, DOE concluded that bulk vitrification is a viable technology that requires additional development to determine its potential applicability to treatment of a portion of the Hanford low activity waste. The DBVS mission need statement now includes the following primary objectives: (1) process approximately 190,000 gallons of Tank S-109 waste into fifty 100 metric ton boxes of vitrified product; (2) store and dispose of these boxes at Hanford's Integrated Disposal Facility (IDF); (3) evaluate the waste form characteristics; (4) gather pilot plant operability data, and (5) develop the overall life cycle system performance of bulk vitrification and produce a comparison of the bulk vitrification process to building a second LAW Immobilization facility or other supplemental treatment alternatives as provided in M-62-08.

  1. Apparatus for forming thin-film heterojunction solar cells employing materials selected from the class of I-III-VI.sub.2 chalcopyrite compounds

    DOE Patents [OSTI]

    Mickelsen, Reid A. (Bellevue, WA); Chen, Wen S. (Seattle, WA)

    1983-01-01T23:59:59.000Z

    Apparatus for forming thin-film, large area solar cells having a relatively high light-to-electrical energy conversion efficiency and characterized in that the cell comprises a p-n-type heterojunction formed of: (i) a first semiconductor layer comprising a photovoltaic active material selected from the class of I-III-VI.sub.2 chalcopyrite ternary materials which is vacuum deposited in a thin "composition-graded" layer ranging from on the order of about 2.5 microns to about 5.0 microns (.congruent.2.5 .mu.m to .congruent.5.0 .mu.m) and wherein the lower region of the photovoltaic active material preferably comprises a low resistivity region of p-type semiconductor material having a superimposed region of relatively high resistivity, transient n-type semiconductor material defining a transient p-n homojunction; and (ii), a second semiconductor layer comprising a low resistivity n-type semiconductor material wherein interdiffusion (a) between the elemental constituents of the two discrete juxtaposed regions of the first semiconductor layer defining a transient p-n homojunction layer, and (b) between the transient n-type material in the first semiconductor layer and the second n-type semiconductor layer, causes the transient n-type material in the first semiconductor layer to evolve into p-type material, thereby defining a thin layer heterojunction device characterized by the absence of voids, vacancies and nodules which tend to reduce the energy conversion efficiency of the system.

  2. Bulk-Brane Interaction and Holographic Dark Energy

    E-Print Network [OSTI]

    M R Setare

    2006-12-14T23:59:59.000Z

    In this paper we consider the bulk-brane interaction to obtain the equation of state for the holographic energy density in non-flat universe enclosed by the event horizon measured from the sphere of horizon named $L$. We assumes that the cold dark matter energy density on the brane is conserved, but the holographic dark energy density on the brane is not conserved due to brane-bulk energy exchange. Our calculation show, taking $\\Omega_{\\Lambda}=0.73$ for the present time, the lower bound of $w_{\\rm \\Lambda}^{eff}$ is -0.9. This implies that one can not generate phantom-like equation of state from an interacting holographic dark energy model in non-flat universe.

  3. Gravity-related spontaneous collapse in bulk matter

    E-Print Network [OSTI]

    Lajos Diósi

    2014-04-26T23:59:59.000Z

    In the DP-model, gravity-related spontaneous wave function collapses suppress undesirable Schr\\"odinger Cat states. We derive the equations of the model for the hydrodynamic-elastic (acoustic) modes in a bulk. Two particular features are discussed: the universal dominance of spontaneous collapses at large wavelengths, and the reduction of spontaneous heating by a slight refinement of the DP-model.

  4. Comparison of bulk- and surface-micromachined pressure sensors

    SciTech Connect (OSTI)

    Eaton, W.P.; Smith, J.H. [Sandia National Labs., Albuquerque, NM (United States); Monk, D.J.; O`Brien, G.; Miller, T.F. [Motorola, Phoenix, AZ (United States)

    1998-08-01T23:59:59.000Z

    Two piezoresistive micromachined pressure sensors were compared: a commercially available bulk-micromachined (BM) pressure sensor and an experimental surface-micromachined (SM) pressure sensor. While the SM parts had significantly smaller die sizes, they were outperformed in most areas by the BM parts. This was due primarily to the smaller piezoresistive gauge factor in the polysilicon piezoresistors in the SM parts compared to the single crystal strain gauge used in the BM parts.

  5. RAPID/BulkTransmission/Alaska | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaski County, Kentucky:County,Quogue isRAPID/BulkTransmission/Alaska

  6. RAPID/BulkTransmission/Hawaii | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaski County,RAPID/BulkTransmission/Hawaii < RAPID‎ |

  7. RAPID/BulkTransmission/Idaho | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaski County,RAPID/BulkTransmission/Hawaii < RAPID‎

  8. RAPID/BulkTransmission/Land Access | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaski County,RAPID/BulkTransmission/Hawaii < RAPID‎Land Access

  9. RAPID/BulkTransmission/Land Use | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaski County,RAPID/BulkTransmission/Hawaii < RAPID‎Land

  10. RAPID/BulkTransmission/Montana | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaski County,RAPID/BulkTransmission/Hawaii <

  11. RAPID/BulkTransmission/Nevada | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaski County,RAPID/BulkTransmission/Hawaii <Nevada < RAPID‎

  12. RAPID/BulkTransmission/New Mexico | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaski County,RAPID/BulkTransmission/Hawaii <Nevada <

  13. RAPID/BulkTransmission/Oregon | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaski County,RAPID/BulkTransmission/Hawaii <Nevada

  14. RAPID/BulkTransmission/Power Plant | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaski County,RAPID/BulkTransmission/Hawaii

  15. RAPID/BulkTransmission/Transmission Siting & Interconnection | Open Energy

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaskiRAPID/BulkTransmission/Texas < RAPID‎ |

  16. RAPID/BulkTransmission/Utah | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaskiRAPID/BulkTransmission/Texas < RAPID‎

  17. RAPID/BulkTransmission/Washington | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaskiRAPID/BulkTransmission/Texas <

  18. RAPID/BulkTransmission/Water Use | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data CenterFranconia, Virginia: EnergyPotentialUrbanUtilityScalePVCapacityPulaskiRAPID/BulkTransmission/Texas

  19. Bulk viscous matter-dominated Universes: asymptotic properties

    SciTech Connect (OSTI)

    Avelino, Arturo [Departamento de Física, Campus León, Universidad de Guanajuato, León, Guanajuato (Mexico); García-Salcedo, Ricardo [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada - Legaria del IPN, México D.F. (Mexico); Gonzalez, Tame [Departamento de Ingeniería Civil, División de Ingeniería, Universidad de Guanajuato, Guanajuato (Mexico); Nucamendi, Ulises [Instituto de Física y Matemáticas, Universidad Michoacana de San Nicolás de Hidalgo, Edificio C-3, Ciudad Universitaria, CP. 58040 Morelia, Michoacán (Mexico); Quiros, Israel, E-mail: avelino@fisica.ugto.mx, E-mail: rigarcias@ipn.mx, E-mail: tamegc72@gmail.com, E-mail: ulises@ifm.umich.mx, E-mail: iquiros6403@gmail.com [Departamento de Matemáticas, Centro Universitario de Ciencias Exactas e Ingenierías (CUCEI), Corregidora 500 S.R., Universidad de Guadalajara, 44420 Guadalajara, Jalisco (Mexico)

    2013-08-01T23:59:59.000Z

    By means of a combined use of the type Ia supernovae and H(z) data tests, together with the study of the asymptotic properties in the equivalent phase space — through the use of the dynamical systems tools — we demonstrate that the bulk viscous matter-dominated scenario is not a good model to explain the accepted cosmological paradigm, at least, under the parametrization of bulk viscosity considered in this paper. The main objection against such scenarios is the absence of conventional radiation and matter-dominated critical points in the phase space of the model. This entails that radiation and matter dominance are not generic solutions of the cosmological equations, so that these stages can be implemented only by means of unique and very specific initial conditions, i. e., of very unstable particular solutions. Such a behavior is in marked contradiction with the accepted cosmological paradigm which requires of an earlier stage dominated by relativistic species, followed by a period of conventional non-relativistic matter domination, during which the cosmic structure we see was formed. Also, we found that the bulk viscosity is positive just until very late times in the cosmic evolution, around z < 1. For earlier epochs it is negative, been in tension with the local second law of thermodynamics.

  20. Standard practice for bulk sampling of liquid uranium hexafluoride

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2001-01-01T23:59:59.000Z

    1.1 This practice covers methods for withdrawing representative samples of liquid uranium hexafluoride (UF6) from bulk quantities of the material. Such samples are used for determining compliance with the applicable commercial specification, for example Specification C787 and Specification C996. 1.2 It is assumed that the bulk liquid UF6 being sampled comprises a single quality and quantity of material. This practice does not address any special additional arrangements that might be required for taking proportional or composite samples, or when the sampled bulk material is being added to UF6 residues already in a container (“heels recycle”). 1.3 The number of samples to be taken, their nominal sample weight, and their disposition shall be agreed upon between the parties. 1.4 The scope of this practice does not include provisions for preventing criticality incidents. 1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of th...

  1. Bulk Viscosity and Cavitation in Boost-Invariant Hydrodynamic Expansion

    E-Print Network [OSTI]

    Krishna Rajagopal; Nilesh Tripuraneni

    2010-02-16T23:59:59.000Z

    We solve second order relativistic hydrodynamics equations for a boost-invariant 1+1-dimensional expanding fluid with an equation of state taken from lattice calculations of the thermodynamics of strongly coupled quark-gluon plasma. We investigate the dependence of the energy density as a function of proper time on the values of the shear viscosity, the bulk viscosity, and second order coefficients, confirming that large changes in the values of the latter have negligible effects. Varying the shear viscosity between zero and a few times s/(4 pi), with s the entropy density, has significant effects, as expected based on other studies. Introducing a nonzero bulk viscosity also has significant effects. In fact, if the bulk viscosity peaks near the crossover temperature Tc to the degree indicated by recent lattice calculations in QCD without quarks, it can make the fluid cavitate -- falling apart into droplets. It is interesting to see a hydrodynamic calculation predicting its own breakdown, via cavitation, at the temperatures where hadronization is thought to occur in ultrarelativistic heavy ion collisions.

  2. Effects of bulk charged impurities on the bulk and surface transport in three-dimensional topological insulators

    SciTech Connect (OSTI)

    Skinner, B.; Chen, T.; Shklovskii, B. I., E-mail: shklovsk@physics.spa.umn.edu [University of Minnesota, Fine Theoretical Physics Institute (United States)

    2013-09-15T23:59:59.000Z

    In the three-dimensional topological insulator (TI), the physics of doped semiconductors exists literally side-by-side with the physics of ultrarelativistic Dirac fermions. This unusual pairing creates a novel playground for studying the interplay between disorder and electronic transport. In this mini-review, we focus on the disorder caused by the three-dimensionally distributed charged impurities that are ubiquitous in TIs, and we outline the effects it has on both the bulk and surface transport in TIs. We present self-consistent theories for Coulomb screening both in the bulk and at the surface, discuss the magnitude of the disorder potential in each case, and present results for the conductivity. In the bulk, where the band gap leads to thermally activated transport, we show how disorder leads to a smaller-than-expected activation energy that gives way to variable-range hopping at low temperatures. We confirm this enhanced conductivity with numerical simulations that also allow us to explore different degrees of impurity compensation. For the surface, where the TI has gapless Dirac modes, we present a theory of disorder and screening of deep impurities, and we calculate the corresponding zero-temperature conductivity. We also comment on the growth of the disorder potential in passing from the surface of the TI into the bulk. Finally, we discuss how the presence of a gap at the Dirac point, introduced by some source of time-reversal symmetry breaking, affects the disorder potential at the surface and the mid-gap density of states.

  3. Risk-based Maintenance Allocation and Scheduling for Bulk Electric Power Transmission System Equipment

    E-Print Network [OSTI]

    most state of the art reliability centered maintenance (RCM) approaches, but it also accounts equipment, maintenance, reliability, risk, security, optimization 1.Introduction Maintenance of bulk1 Risk-based Maintenance Allocation and Scheduling for Bulk Electric Power Transmission System

  4. Notes 10. A thermohydrodynamic bulk-flow model for fluid film bearings

    E-Print Network [OSTI]

    San Andres, Luis

    2009-01-01T23:59:59.000Z

    The complete set of bulk-flow equations for the analysis of turbulent flow fluid film bearings. Importance of thermal effects in process fluid applications. A CFD method for solution of the bulk-flow equations....

  5. Characterization of Surface and Bulk Nitrates of ?-Al2O3...

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

    Surface and Bulk Nitrates of ?-Al2O3-Supported Alkaline Earth Oxides using Density Functional Theory. Characterization of Surface and Bulk Nitrates of ?-Al2O3-Supported...

  6. Analysis and forecast of the capesize bulk carriers shipping market using Artificial Neural Networks

    E-Print Network [OSTI]

    Voudris, Athanasios V

    2006-01-01T23:59:59.000Z

    Investing in the bulk carrier market constitutes a rather risky investment due to the volatility of the bulk carrier freight rates. In this study it is attempted to uncover the benefits of using Artificial Neural Networks ...

  7. Corrosion of, and cellular responses to MgZnCa bulk metallic glasses Xuenan Gu a

    E-Print Network [OSTI]

    Zheng, Yufeng

    Corrosion of, and cellular responses to Mg­Zn­Ca bulk metallic glasses Xuenan Gu a , Yufeng Zheng a: Magnesium alloy Bulk metallic glass Mechanical property Corrosion Cytotoxicity a b s t r a c t Mg­Zn­Ca bulk, mechanical testing, corrosion and cytotoxicity tests. It was found that the Mg66Zn30Ca4 sample presents

  8. Identification of Avalanche Precursors by Acoustic Probing in the Bulk of Tilted Granular Layers

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Identification of Avalanche Precursors by Acoustic Probing in the Bulk of Tilted Granular Layers M simultaneously caracterize precursors on the free surface with an optical method and in the bulk with acoustic to probe rearrangements in the bulk of the granular material. A linear method can also be used provided

  9. Efficient Bulk Data Replication for the Earth System Grid

    SciTech Connect (OSTI)

    Sim, Alex; Gunter, Dan; Natarajan, Vijaya; Shoshani, Arie; Williams, Dean; Long, Jeff; Hick, Jason; Lee, Jason; Dart, Eli

    2010-03-10T23:59:59.000Z

    The Earth System Grid (ESG) community faces the difficult challenge of managing the distribution of massive data sets to thousands of scientists around the world. To move data replicas efficiently, the ESG has developed a data transfer management tool called the Bulk Data Mover (BDM). We describe the performance results of the current system and plans towards extending the techniques developed so far for the up- coming project, in which the ESG will employ advanced networks to move multi-TB datasets with the ulti- mate goal of helping researchers understand climate change and its potential impacts on world ecology and society.

  10. Radiative cooling of bulk silicon by incoherent light pump

    SciTech Connect (OSTI)

    Malyutenko, V. K., E-mail: malyut@isp.kiev.ua; Bogatyrenko, V. V.; Malyutenko, O. Yu. [V. E. Lashkaryov Institute of Semiconductor Physics, 03028 Kiev (Ukraine)] [V. E. Lashkaryov Institute of Semiconductor Physics, 03028 Kiev (Ukraine)

    2013-12-23T23:59:59.000Z

    In contrast to radiative cooling by light up conversion caused exclusively by a low-entropy laser pump and employing thermally assisted fluorescence/luminescence as a power out, we demonstrate light down conversion cooling by incoherent pumps, 0.47–0.94??m light emitting diodes, and employing thermal emission (TE) as a power out. We demonstrate ?3.5?K bulk cooling of Si at 450?K because overall energy of multiple below bandgap TE photons exceeds the energy of a single above bandgap pump photon. We show that using large entropy TE as power out helps avoid careful tuning of an incoherent pump wavelength and cool indirect-bandgap semiconductors.

  11. Bulk Handling of Milk on Texas Dairy Farms.

    E-Print Network [OSTI]

    Parker, Cecil A.; Stelly, Randall, Moore, Donald S.

    1958-01-01T23:59:59.000Z

    areas dur- tem of handling milk. ing the spring and summer of 1957 on dairy - farms which have converted their operations to Dairymen interviewed in North Texas had tanks ranging from 150 gallons to 1,000 gallons, , the bulk system of producing... and handling milk. while tanks in the Corous Christi area raneDd Texas dairy farmers are operating larger from 200 gallons to 1,000 gallons. The average units, milking more cows, selling more milk and tank in North Texas had a capacity of 400 gal. generally...

  12. Bulk Energy Storage Webinar Rescheduled for February 9, 2012 | Department

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of Energy Power Systems EngineeringDepartment of4 Federal6Clean Energyof Energy Bulk Energy Storage

  13. Bulk Hauling Equipment for CHG | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTie Ltd:June 2015 < prevBuilding theINNOVATION &Bulk Hauling

  14. Tilting the Primordial Power Spectrum with Bulk Viscosity

    E-Print Network [OSTI]

    James E. Lidsey

    1993-12-16T23:59:59.000Z

    Within the context of the cold dark matter model, current observations suggest that inflationary models which generate a tilted primordial power spectrum with negligible gravitational waves provide the most promising mechanism for explaining large scale clustering. The general form of the inflationary potential which produces such a spectrum is a hyperbolic function and is interpreted physically as a bulk viscous stress contribution to the energy-momentum of a perfect baryotropic fluid. This is equivalent to expanding the equation of state as a truncated Taylor series. Particle physics models which lead to such a potential are discussed.

  15. Scanning Tunneling Macroscopy, Black Holes, and AdS/CFT Bulk Locality

    E-Print Network [OSTI]

    Soo-Jong Rey; Vladimir Rosenhaus

    2014-06-02T23:59:59.000Z

    We establish resolution bounds on reconstructing a bulk field from boundary data on a timelike hypersurface. If the bulk only supports propagating modes, reconstruction is complete. If the bulk also supports evanescent modes, local reconstruction is not achievable unless one has exponential precision in knowledge of the boundary data. Without exponential precision, for a Minkowski bulk, one can reconstruct a spatially coarse-grained bulk field, but only out to a depth set by the coarse-graining scale. For an asymptotically AdS bulk, reconstruction is limited to a spatial coarse-graining proper distance set by the AdS scale. AdS black holes admit evanescent modes. We study the resolution bound in the large AdS black hole background and provide a dual CFT interpretation. Our results demonstrate that, if there is a black hole of any size in the bulk, then sub-AdS bulk locality is no longer well-encoded in boundary data in terms of local CFT operators. Specifically, in order to probe the bulk on sub-AdS scales using only boundary data in terms of local operators, one must either have such data to exponential precision or make further assumptions about the bulk state.

  16. GALAXY CLUSTER BULK FLOWS AND COLLISION VELOCITIES IN QUMOND

    SciTech Connect (OSTI)

    Katz, Harley; McGaugh, Stacy; Teuben, Peter [Department of Astronomy, University of Maryland, College Park, MD 20742 (United States); Angus, G. W., E-mail: hkatz@astro.umd.edu, E-mail: stacy.mcgaugh@case.edu, E-mail: teuben@astro.umd.edu, E-mail: angus.gz@gmail.com [Astrophysics, Cosmology and Gravity Centre, University of Cape Town, Private Bag X3, Rondebosch 7700 (South Africa)

    2013-07-20T23:59:59.000Z

    We examine the formation of clusters of galaxies in numerical simulations of a QUMOND cosmogony with massive sterile neutrinos. Clusters formed in these exploratory simulations develop higher velocities than those found in {Lambda}CDM simulations. The bulk motions of clusters attain {approx}1000 km s{sup -1} by low redshift, comparable to observations whereas {Lambda}CDM simulated clusters tend to fall short. Similarly, high pairwise velocities are common in cluster-cluster collisions like the Bullet Cluster. There is also a propensity for the most massive clusters to be larger in QUMOND and to appear earlier than in {Lambda}CDM, potentially providing an explanation for ''pink elephants'' like El Gordo. However, it is not obvious that the cluster mass function can be recovered.

  17. FINITE ELEMENT ANALYSIS OF BULK TRITIUM SHIPPING PACKAGE

    SciTech Connect (OSTI)

    Jordan, J.

    2010-06-02T23:59:59.000Z

    The Bulk Tritium Shipping Package was designed by Savannah River National Laboratory. This package will be used to transport tritium. As part of the requirements for certification, the package must be shown to meet the scenarios of the Hypothetical Accident Conditions (HAC) defined in Code of Federal Regulations Title 10 Part 71 (10CFR71). The conditions include a sequential 30-foot drop event, 30-foot dynamic crush event, and a 40-inch puncture event. Finite Element analyses were performed to support and expand upon prototype testing. Cases similar to the tests were evaluated. Additional temperatures and orientations were also examined to determine their impact on the results. The peak stress on the package was shown to be acceptable. In addition, the strain on the outer drum as well as the inner containment boundary was shown to be acceptable. In conjunction with the prototype tests, the package was shown to meet its confinement requirements.

  18. Freeze-out by bulk viscosity driven instabilities

    E-Print Network [OSTI]

    Torrieri, Giorgio; Mishustin, Igor

    2008-01-01T23:59:59.000Z

    We describe a new scenario (first introduced in [G. Torrieri, B. Tom\\'a\\v{s}ik and I. Mishustin, Phys. Rev. C \\textbf{77}, 034903 (2008)]) for freezeout in heavy ion collisions that could solve the lingering problems associated with the so-called HBT puzzle. We argue that bulk viscosity increases as $T$ approaches $T_c$. The fluid {then} becomes unstable against small perturbations, and fragments into clusters of a size much smaller than the total size of the system. These clusters maintain the pre-existing outward-going flow, as a spray of droplets, but develop no flow of their own, and hadronize by evaporation. We show that this scenario can explain HBT data and suggest how it can be experimentally tested.

  19. Cavitation from bulk viscosity in neutron stars and quark stars

    E-Print Network [OSTI]

    Jes Madsen

    2009-09-30T23:59:59.000Z

    The bulk viscosity in quark matter is sufficiently high to reduce the effective pressure below the corresponding vapor pressure during density perturbations in neutron stars and strange stars. This leads to mechanical instability where the quark matter breaks apart into fragments comparable to cavitation scenarios discussed for ultra-relativistic heavy-ion collisions. Similar phenomena may take place in kaon-condensed stellar cores. Possible applications to compact star phenomenology include a new mechanism for damping oscillations and instabilities, triggering of phase transitions, changes in gravitational wave signatures of binary star inspiral, and astrophysical formation of strangelets. At a more fundamental level it points to the possible inadequacy of a hydrodynamical treatment of these processes in compact stars.

  20. Evaluation of ANSI compression in a bulk data file transfer system.

    E-Print Network [OSTI]

    Chaulklin, Douglas Gary

    2010-01-01T23:59:59.000Z

    ??This report evaluates the use of a newly proposed American National Standard Institute (ANSI) standard for data compression in a bulk data transmission system. An… (more)

  1. E-Print Network 3.0 - aqueous bulk sample Sample Search Results

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

    that aqueous processing has shifted some samples to heavier compositions. A lower bulk solar... processes involving aqueous fluids, given the potential solubility of lithium...

  2. E-Print Network 3.0 - air-processed polymer-fullerene bulk Sample...

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

    are currently seen as attractive materials for optoelectronic applications such as light-emitting diodes and solar cells. Excitonic processes play Summary: phase of bulk...

  3. The Role of Surface Chemistry and Bulk Properties on the Cycling...

    Broader source: Energy.gov (indexed) [DOE]

    (ANL) Research Objectives: To develop fundamental understanding of surface chemistry and bulk cation distributions on cycling performance and rate capability To...

  4. The Role of Surface Chemistry and Bulk Properties on the Cycling...

    Broader source: Energy.gov (indexed) [DOE]

    and Rate Capability of Lithium Positive Electrode Materials The Role of Surface Chemistry and Bulk Properties on the Cycling and Rate Capability of Lithium Positive Electrode...

  5. Bulk matter fields on a GRS-inspired braneworld

    SciTech Connect (OSTI)

    Liu, Yu-Xiao; Fu, Chun-E; Guo, Heng; Wei, Shao-Wen; Zhao, Zhen-Hua, E-mail: liuyx@lzu.edu.cn, E-mail: fuche08@lzu.cn, E-mail: guoh06@lzu.cn, E-mail: weishaow06@lzu.cn, E-mail: zhaozhh09@lzu.cn [Institute of Theoretical Physics, Lanzhou University, Lanzhou 730000 (China)

    2010-12-01T23:59:59.000Z

    In this paper we investigate the localization and mass spectra of bulk matter fields on a Gergory-Rubakov-Sibiryakov-inspired braneworld. In this braneworld model, there are one thick brane located at the origin of the extra dimension and two thin branes at two sides. For spin 1/2 fermions coupled with the background scalar ? via ? ?-bar ?{sup p}? with p a positive odd integer, the zero mode of left-hand fermions can be localized on the thick brane for finite distance of the two thin branes, and there exist some massive bound modes and resonance modes. The resonances correspond to the quasi-localized massive fermions. For free massless spin 0 scalars, the zero mode can not be localized on the thick brane when the two thin branes are located finitely. While for a massive scalar ? coupled with itself and the background scalar field ?, in order to get a localized zero mode on the thick brane, a fine-tuning relation should be introduced. Some massive bound modes and resonances also will appear. For spin 1 vectors, there is no bound KK mode because the effective potential felt by vectors vanishes outside the two thin branes. We also investigate the physics when the distance of the two thin branes tends to infinity.

  6. International Round-Robin Testing of Bulk Thermoelectrics

    SciTech Connect (OSTI)

    Wang, Hsin [ORNL; Porter, Wallace D [ORNL; Bottner, Harold [Fraunhofer-Institute, Freiburg, Germany; Konig, Jan [Fraunhofer-Institute, Freiburg, Germany; Chen, Lidong [Chinese Academy of Sciences; Bai, Shengqiang [Chinese Academy of Sciences; Tritt, Terry M. [Clemson University; Mayolett, Alex [Corning, Inc; Smith, Charlene [Corning, Inc; Harris, Fred [ZT-Plus; Sharp, Jeff [Marlow Industries, Inc; Lo, Jason [CANMET - Materials Technology Laboratory, Natural Resources of Canada; Keinke, Holger [University of Waterloo, Canada; Kiss, Laszlo I. [University of Quebec at Chicoutimi

    2011-11-01T23:59:59.000Z

    Two international round-robin studies were conducted on transport properties measurements of bulk thermoelectric materials. The study discovered current measurement problems. In order to get ZT of a material four separate transport measurements must be taken. The round-robin study showed that among the four properties Seebeck coefficient is the one can be measured consistently. Electrical resistivity has +4-9% scatter. Thermal diffusivity has similar +5-10% scatter. The reliability of the above three properties can be improved by standardizing test procedures and enforcing system calibrations. The worst problem was found in specific heat measurements using DSC. The probability of making measurement error is great due to the fact three separate runs must be taken to determine Cp and the baseline shift is always an issue for commercial DSC. It is suggest the Dulong Petit limit be always used as a guide line for Cp. Procedures have been developed to eliminate operator and system errors. The IEA-AMT annex is developing standard procedures for transport properties testing.

  7. Corrosion performances in simulated body fluids and cytotoxicity evaluation of Fe-based bulk metallic glasses

    E-Print Network [OSTI]

    Zheng, Yufeng

    Corrosion performances in simulated body fluids and cytotoxicity evaluation of Fe-based bulk December 2011 Available online 27 December 2011 Keywords: Bulk metallic glass Corrosion Biocompatibility Electrochemical characterization Biomedical applications The aim of this work is to investigate the corrosion

  8. Spectroscopic Imaging of Single AtomsWithin a Bulk Solid S. D. Findlay,2

    E-Print Network [OSTI]

    Pennycook, Steve

    identification of single atoms on surfaces, but they cannot probe individual atoms within the bulk environmentSpectroscopic Imaging of Single AtomsWithin a Bulk Solid M.Varela,1 S. D. Findlay,2 A. R. Lupini,1, but their spectroscopic identification, with spatial resolution at the atomic scale. This substan- tial improvement

  9. Equality of bulk and edge Hall conductances for continuous magnetic random Schrödinger operators

    E-Print Network [OSTI]

    Amal Taarabt

    2014-03-30T23:59:59.000Z

    In this note, we prove the equality of the quantum bulk and the edge Hall conductances in mobility edges and in presence of disorder. The bulk and edge perturbations can be either of electric or magnetic nature. The edge conductance is regularized in a suitable way to enable the Fermi level to lie in a region of localized states.

  10. RowClone: Fast and Energy-Efficient In-DRAM Bulk Data Copy and Initialization

    E-Print Network [OSTI]

    RowClone: Fast and Energy-Efficient In-DRAM Bulk Data Copy and Initialization Processor MemoryChannel Limited bandwidth High energy Carnegie Mellon University Intel Pittsburgh #12;RowClone: Fast and Energy-Efficient University Intel Pittsburgh #12;RowClone: Fast and Energy-Efficient In-DRAM Bulk Data Copy and Initialization

  11. Bulk superconductivity in Type II superconductors near the second critical field

    E-Print Network [OSTI]

    S. Fournais; B. Helffer

    2008-02-14T23:59:59.000Z

    We consider superconductors of Type II near the transition from the 'bulk superconducting' to the 'surface superconducting' state. We prove a new $L^{\\infty}$ estimate on the order parameter in the bulk, i.e. away from the boundary. This solves an open problem posed by Aftalion and Serfaty.

  12. Single pulse ultrafast laser imprinting of axial dot arrays in bulk glasses C. Mauclair,1,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Single pulse ultrafast laser imprinting of axial dot arrays in bulk glasses C. Mauclair,1, A sam- ples were irradiated with 160 fs pulses from an 800 nm Ti:Sapphire amplified ultrafast laser.mauclair@univ-st-etienne.fr Compiled December 20, 2010 Ultrafast laser processing of bulk transparent materials can significantly gain

  13. Water-induced Bulk Ba(NO3)2 Formation From NO2 Exposed Thermally...

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

    Bulk Ba(NO3)2 Formation From NO2 Exposed Thermally Aged BaOAl2O3. Water-induced Bulk Ba(NO3)2 Formation From NO2 Exposed Thermally Aged BaOAl2O3. Abstract: Phase changes in high...

  14. Integrating Bulk-Data Transfer into the Aurora Distributed Shared Data System

    E-Print Network [OSTI]

    Lu, Paul

    Integrating Bulk-Data Transfer into the Aurora Distributed Shared Data System Paul Lu Dept version, with corrections to JPDC proofs 1 #12;Running Head: Integrating Bulk-Data Transfer into Aurora-1071 Web: http://www.cs.ualberta.ca/~paullu/ Abstract The Aurora distributed shared data system implements

  15. Explosive shock processing of Pr2Fe14B/ Fe exchange-coupled nanocomposite bulk magnets

    E-Print Network [OSTI]

    Liu, J. Ping

    Explosive shock processing of Pr2Fe14B/ ­Fe exchange-coupled nanocomposite bulk magnets Z.Q. Jin between neigh- boring magnetic phases.1,2 The prerequisite for effective exchange coupling is a small are usually used to produce single-phase microcrystalline permanent magnets, are not favored in making bulk

  16. 1Cellular Polymers, Vol. 26, No. 1, 2007 On the Bulk Modulus of Open Cell Foams

    E-Print Network [OSTI]

    Lakes, Roderic

    Hydrostaticcompressionoffoamisofinterestinavarietyofcontextsincluding under-sea applications. Syntactic foam, for instance, consists of hollow glass1Cellular Polymers, Vol. 26, No. 1, 2007 On the Bulk Modulus of Open Cell Foams © Rapra Technology, 2007 On the Bulk Modulus of Open Cell Foams B. Moore, T. Jaglinski, D.S. Stone§ and R.S. Lakes

  17. Matter in the Bulk and its Consequences on the Brane: A Possible Source of Dark Energy

    E-Print Network [OSTI]

    Subenoy Chakraborty; Asit Banerjee; Tanwi Bandyopadhyay

    2007-07-02T23:59:59.000Z

    The usual brane world scenario with anti de Sitter bulk has been generalized by considering a general form of energy momentum tensor in the bulk. The modified Einstein equation on the brane has been constructed. Two examples have been cited of which, the first one shows the usual brane equations when matter in the bulk is a negative cosmological constant. In the second example, the bulk matter is in the form of perfect fluid and as a result, an effective perfect fluid is obtained in the brane. Also it is noted that the effect of the dust bulk on the brane shows a dark energy behaviour and may be a possible explanation of the dark energy from the present day observational point of view.

  18. An easy-to-fabricate low-temperature TiO{sub 2} electron collection layer for high efficiency planar heterojunction perovskite solar cells

    SciTech Connect (OSTI)

    Conings, B.; Baeten, L.; Jacobs, T.; Dera, R.; D’Haen, J.; Manca, J.; Boyen, H.-G. [Instituut voor Materiaalonderzoek, Universiteit Hasselt, Wetenschapspark 1, 3590 Diepenbeek (Belgium)

    2014-08-01T23:59:59.000Z

    Organometal trihalide perovskite solar cells arguably represent the most auspicious new photovoltaic technology so far, as they possess an astonishing combination of properties. The impressive and brisk advances achieved so far bring forth highly efficient and solution processable solar cells, holding great promise to grow into a mature technology that is ready to be embedded on a large scale. However, the vast majority of state-of-the-art perovskite solar cells contains a dense TiO{sub 2} electron collection layer that requires a high temperature treatment (>450?°C), which obstructs the road towards roll-to-roll processing on flexible foils that can withstand no more than ?150?°C. Furthermore, this high temperature treatment leads to an overall increased energy payback time and cumulative energy demand for this emerging photovoltaic technology. Here we present the implementation of an alternative TiO{sub 2} layer formed from an easily prepared nanoparticle dispersion, with annealing needs well within reach of roll-to-roll processing, making this technology also appealing from the energy payback aspect. Chemical and morphological analysis allows to understand and optimize the processing conditions of the TiO{sub 2} layer, finally resulting in a maximum obtained efficiency of 13.6% for a planar heterojunction solar cell within an ITO/TiO{sub 2}/CH{sub 3}NH{sub 3}PbI{sub 3-x}Cl{sub x}poly(3-hexylthiophene)/Ag architecture.

  19. Stability of Bulk Metallic Glass Structure. Final Report

    SciTech Connect (OSTI)

    Jain, H.; Williams, D. B.

    2003-06-01T23:59:59.000Z

    The fundamental origins of the stability of the (Pd-Ni){sub 80}P{sub 20} bulk metallic glasses (BMGs), a prototype for a whole class of BMG formers, were explored. While much of the properties of their BMGs have been characterized, their glass-stability have not been explained in terms of the atomic and electronic structure. The local structure around all three constituent atoms was obtained, in a complementary way, using extended X-ray absorption fine structure (EXAFS), to probe the nearest neighbor environment of the metals, and extended energy loss fine structure (EXELFS), to investigate the environment around P. The occupied electronic structure was investigated using X-ray photoelectron spectroscopy (XPS). The (Pd-Ni){sub 80}P{sub 20} BMGs receive their stability from cumulative, and interrelated, effects of both atomic and electronic origin. The stability of the (Pd-Ni){sub 80}P{sub 20} BMGs can be explained in terms of the stability of Pd{sub 60}Ni{sub 20}P{sub 20} and Pd{sub 30}Ni{sub 50}P{sub 20}, glasses at the end of BMG formation. The atomic structure in these alloys is very similar to those of the binary phosphide crystals near x=0 and x=80, which are trigonal prisms of Pd or Ni atoms surrounding P atoms. Such structures are known to exist in dense, randomly-packed systems. The structure of the best glass former in this series, Pd{sub 40}Ni{sub 40}P{sub 20} is further described by a weighted average of those of Pd{sub 30}Ni{sub 50}P{sub 20} and Pd{sub 60}Ni{sub 20}P{sub 20}. Bonding states present only in the ternary alloys were found and point to a further stabilization of the system through a negative heat of mixing between Pd and Ni atoms. The Nagel and Tauc criterion, correlating a decrease in the density of states at the Fermi level with an increase in the glass stability, was consistent with greater stability of the Pd{sub x}Ni{sub 80-x}P{sub 20} glasses with respect to the binary alloys of P. A valence electron concentration of 1.8 e/a, which ensures the superpositioning of the first peak in the structure factor with twice the Fermi momentum, was used to calculate the interatomic potential of these alloys. The importance of Pd to the stability of the alloys is evidenced by the fact that replacing Ni and Pd places the nearest neighbor distances at more attractive positions in this potential.

  20. Bulk Nanostructured FCC Steels With Enhanced Radiation Tolerance

    SciTech Connect (OSTI)

    Zhang, Xinghang; Hartwig, K. Ted; Allen, Todd; Yang, Yong

    2012-10-27T23:59:59.000Z

    The objective of this project is to increase radiation tolerance in austenitic steels through optimization of grain size and grain boundary (GB) characteristics. The focus will be on nanocrystalline austenitic Fe-Cr-Ni alloys with an fcc crystal structure. The long-term goal is to design and develop bulk nanostructured austenitic steels with enhanced void swelling resistance and substantial ductility, and to enhance their creep resistance at elevated temperatures via GB engineering. The combination of grain refinement and grain boundary engineering approaches allows us to tailor the material strength, ductility, and resistance to swelling by 1) changing the sink strength for point defects, 2) by increasing the nucleation barriers for bubble formation at GBs, and 3) by changing the precipitate distributions at boundaries. Compared to ferritic/martensitic steels, austenitic stainless steels (SS) possess good creep and fatigue resistance at elevated temperatures, and better toughness at low temperature. However, a major disadvantage of austenitic SS is that they are vulnerable to significant void swelling in nuclear reactors, especially at the temperatures and doses anticipated in the Advanced Burner Reactor. The lack of resistance to void swelling in austenitic alloys led to the switch to ferritic/martensitic steels as the preferred material for the fast reactor cladding application. Recently a type of austenitic stainless steel, HT-UPS, was developed at ORNL, and is expected to show enhanced void swelling resistance through the trapping of point defects at nanometersized carbides. Reducing the grain size and increasing the fraction of low energy grain boundaries should reduce the available radiation-produced point defects (due to the increased sink area of the grain boundaries), should make bubble nucleation at the boundaries less likely (by reducing the fraction of high-energy boundaries), and improve the strength and ductility under radiation by producing a higher density of nanometer sized carbides on the boundaries. This project will focus on void swelling but advances in processing of austenitic steels are likely to also improve the radiation response of the mechanical properties.

  1. Bulk and surface laser damage of silica by picosecond and nanosecond pulses at 1064 nm

    SciTech Connect (OSTI)

    Smith, Arlee V.; Do, Binh T

    2008-09-10T23:59:59.000Z

    We measured bulk and surface dielectric breakdown thresholds of pure silica for 14 ps and 8 ns pulses of 1064 nm light. The thresholds are sharp and reproducible. For the 8 ns pulses the bulk threshold irradiance is 4.75 {+-} 0.25 kW/{mu}m{sup 2}. The threshold is approximately three times higher for 14 ps pulses. For 8 ns pulses the input surface damage threshold can be made equal to the bulk threshold by applying an alumina or silica surface polish.

  2. Bulk Tungsten in the JET Divertor: Potential Influence of the Exhaustion of Ductility and Grain Growth on the Lifetime

    E-Print Network [OSTI]

    Bulk Tungsten in the JET Divertor: Potential Influence of the Exhaustion of Ductility and Grain Growth on the Lifetime

  3. Clamping of Solid Tungsten Components for the Bulk W Divertor Row in JET – Precautionary Design for a Brittle Material

    E-Print Network [OSTI]

    Clamping of Solid Tungsten Components for the Bulk W Divertor Row in JET – Precautionary Design for a Brittle Material

  4. Power Handling of the Bulk Tungsten Divertor Row at JET: First Measurements and Comparison to the GTM Thermal Model

    E-Print Network [OSTI]

    Power Handling of the Bulk Tungsten Divertor Row at JET: First Measurements and Comparison to the GTM Thermal Model

  5. Strontium Titanate DC Electric Field Switchable and Tunable Bulk Acoustic Wave Solidly Mounted Resonator

    E-Print Network [OSTI]

    York, Robert A.

    Strontium Titanate DC Electric Field Switchable and Tunable Bulk Acoustic Wave Solidly Mounted Abstract - A voltage switchable/tunable strontium titanate solidly mounted BAW resonator was implemented films, piezoelectric resonators. I. INTRODUCTION Strontium titanate (STO) and barium strontium titanate

  6. Residential Bulk-Fed Wood-Pellet Central Boilers and Furnace Rebate Program

    Broader source: Energy.gov [DOE]

    The New Hampshire Public Utilities Commission (PUC) is offering rebates of 30% of the installed cost of qualifying new residential bulk-fed, wood-pellet central heating boilers or furnaces. The...

  7. Dye-doped polymer nanoparticles for flexible, bulk luminescent solar concentrators

    E-Print Network [OSTI]

    Rosenberg, Ron, S.B. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    Bulk luminescent solar concentrators (LSC) cannot make use of Forster resonance energy transfer (FRET) due to necessarily low dye concentrations. In this thesis, we attempt to present a poly-vinylalcohol (PVA) waveguide ...

  8. Development of a Bulk GaN Growth Technique for Low Defect Density...

    Broader source: Energy.gov (indexed) [DOE]

    current due to bulk defects GaN is Grown Heteroepitaxially on Sapphire (and Silicon Carbide) Substrates * As grown GaN nucleation layers contain disordered GaN with many...

  9. Bulk power risk analysis : ranking infrastructure elements according to their risk significance

    E-Print Network [OSTI]

    Koonce, Anthony M

    2006-01-01T23:59:59.000Z

    Disruptions in the bulk power grid can result in very diverse consequences that include economic, social, physical, and psychological impacts. In addition, power outages do not affect all end-users of the system in the ...

  10. All bulk and boundary unitary cubic curvature theories in three dimensions

    SciTech Connect (OSTI)

    Guellue, Ibrahim; Sisman, Tahsin Cagri; Tekin, Bayram [Department of Physics, Middle East Technical University, 06531, Ankara (Turkey)

    2011-01-15T23:59:59.000Z

    We construct all the bulk and boundary unitary cubic curvature parity invariant gravity theories in three dimensions in (anti)-de Sitter spaces. For bulk unitarity, our construction is based on the principle that the free theory of the cubic curvature theory reduces to one of the three known unitary theories which are the cosmological Einstein-Hilbert theory, the quadratic theory of the scalar curvature, or the new massive gravity (NMG). Bulk and boundary unitarity in NMG is in conflict; therefore, cubic theories that are unitary both in the bulk and on the boundary have free theories that reduce to the other two alternatives. We also study the unitarity of the Born-Infeld extensions of NMG to all orders in curvature.

  11. Correlation Between Structure and Thermoelectric Properties of Bulk High Performance Materials for Energy Conversion

    Broader source: Energy.gov [DOE]

    Rapid solidified precursor converted into crystalline bulks under pressure produced thermoelectric materials of nano-sized grains with strongly coupled grain boundaries, achieving reduced lattice thermal conductivity and increased power factor

  12. High Temperature Deformation Behavior of in-situ Bulk Metallic Glass Matrix Composites

    E-Print Network [OSTI]

    Fu, X.L.

    Macroscopic ductility is promoted in bulk metallic glasses by both composite reinforcements (at low temperatures) and by the activation of viscous flow mechanisms (at high temperatures). It is of fundamental interest to ...

  13. Near-Bulk Conductivity of Gold Nanowires as Nanoscale Interconnects and the Role of Atomically

    E-Print Network [OSTI]

    Zubarev, Eugene

    Near-Bulk Conductivity of Gold Nanowires as Nanoscale Interconnects and the Role of Atomically, a significant portion of the chip is composed of interconnects. Besides, the engineering problems associated loss, signal degradation, interconnection delays, and other performance limitations related

  14. E-Print Network 3.0 - anoxic bulk soil Sample Search Results

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

    Redox potentiala (mV) n120 Soil water contentb (% wet weight) n4 Bulk densityb (g cm... ECOSYSTEM ECOLOGY Gordon W. Holtgrieve Peter K. Jewett Pamela A. ... Source:...

  15. Nonequilibrium molecular dynamics simulations of confined fluids in contact with the bulk

    E-Print Network [OSTI]

    Zhang, Luzheng

    Nonequilibrium molecular dynamics simulations of confined fluids in contact with the bulk Luzheng Zhang, Ramkumar Balasundaram,a) and Stevin H. Gehrke Department of Chemical Engineering, Kansas State University, Manhattan, Kansas 66506 Shaoyi Jiangb) Department of Chemical Engineering, University

  16. Using a surface-sensitive chemical probe and a bulk structure...

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

    probe and a bulk structure technique to monitor the ?- to ?-Al2O3 phase Abstract: In this work, we investigated the phase transformation of ? Al2O3 to...

  17. Using first principles Destiny Functional Theory methods to model the Seebeck coefficient of bulk silicon

    E-Print Network [OSTI]

    Mehra, Saahil

    2008-01-01T23:59:59.000Z

    Thermoelectrics are gaining significant amounts of attention considering their relevance today in the areas of sustainable energy generation and energy efficiency. In this thesis, the thermoelectric properties of bulk ...

  18. In vitro Corrosion and Haemocompatibility of Bulk Nanocrystalline 304 Stainless Steel by Severe Rolling

    E-Print Network [OSTI]

    Zheng, Yufeng

    In vitro Corrosion and Haemocompatibility of Bulk Nanocrystalline 304 Stainless Steel by Severe@imr.ac.cn Keywords: nanocrystalline 304ss; electrochemical corrosion; ion release; cellular morphology after the severe plastic deformation. The electrochemical corrosion resistance and ion release behavior

  19. E-Print Network 3.0 - activity-dependent bulk endocytosis Sample...

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

    results for: activity-dependent bulk endocytosis Page: << < 1 2 3 4 5 > >> 1 VESICLE RECYCLING AT RIBBON SYNAPSES IN THE FINELY BRANCHED AXON TERMINALS OF MOUSE RETINAL BIPOLAR...

  20. E-Print Network 3.0 - al bulk crystals Sample Search Results

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

    are homogeneously dispersed in the residual glass of the bulk for Tc... consists of titanite (CaTiSiO5) and anorthite (CaAl2Si2O8) crystals that have nucleated heterogeneously......

  1. An analysis of bulk agricultural commodity buying behavior in selected developing economies

    E-Print Network [OSTI]

    Moore, Kimberly Renee

    1982-01-01T23:59:59.000Z

    AN ANALYSIS OF BULK AGRICULTURAL COMMODITY BUYING BEHAVIOR IN SELECTED DEVELOPING ECONOMIES A Thesis by Kimberly Renee Moore Submitted to the Graduate College of Texas AAM University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE May 1982 Major Subject: Agricultural Economics AN ANALYSIS OF BULK AGRICULTURAL COMMODITY BUYING BEHAVIOR IN SELECTED DEVELOPING ECONOMIES A Thesis by Kimberly Renee Moore Approved as to style and content by: ( i n o Committee...

  2. Emergent Universe in Brane World Scenario with Schwarzschild-de Sitter Bulk

    E-Print Network [OSTI]

    Asit Banerjee; Tanwi Bandyopadhyay; Subenoy Chakraborty

    2007-11-27T23:59:59.000Z

    A model of an emergent universe is obtained in brane world. Here the bulk energy is in the form of cosmological constant, while the brane consists of a fluid satisfying an equation of state of the form $p_{b}={1/3} \\rho_{b}$, which is effectively a radiation equation of state at high energies. It is shown that with the positive bulk cosmological constant, one of our models represents an emergent universe.

  3. Bulk and track etch properties of CR-39 SSNTD etched in NaOH/ethanol

    E-Print Network [OSTI]

    Yu, K.N.

    Bulk and track etch properties of CR-39 SSNTD etched in NaOH/ethanol K.F. Chan, F.M.F. Ng, D. described the use of NaOH/ethanol as an etchant for the CR-39 detector, and have determined the corre and track etch properties of CR- 39 in NaOH/ethanol were derived from direct measurements. The bulk etch

  4. Chemical reactions at Cu/ZnS(001) and In/ZnS(001) heterojunctions: A comparison of photoelectron and S L{sub 2,3} x-ray emission spectroscopy

    SciTech Connect (OSTI)

    Zhang, L.; Wett, D.; Schulze, D.; Szargan, R.; Nagel, M.; Peisert, H.; Chasse, T. [Institut fuer Physikalische und Theoretische Chemie, Universitaet Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen (Germany); Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Universitaet Leipzig, Linnestrasse 2, 04103 Leipzig (Germany); Wilhelm-Ostwald-Institut fuer Physikalische und Theoretische Chemie, Universitaet Leipzig, Linnestrasse 2, 04103 Leipzig (Germany); Institut fuer Physikalische und Theoretische Chemie, Universitaet Tuebingen, Auf der Morgenstelle 8, 72076 Tuebingen (Germany)

    2005-01-03T23:59:59.000Z

    Occurrence and extent of chemical reactions at Cu/ZnS(001) and In/ZnS(001) heterojunctions have been investigated by S L{sub 2,3} x-ray emission spectroscopy as well as photoelectron spectroscopy. With the formation of metal-sulfur bonds, spectral features originating from shallow metal d core levels (Zn 3d, In 4d) or valence states (Cu 3d)) may appear in the S L{sub 2,3} emission spectra. Thus the x-ray emission spectroscopy was employed to detect chemical reactions at the heterojunctions, together with conventional photoelectron spectroscopy. Considerable reactions at the Cu/ZnS(001) interface are more clearly indicated in the S L emission spectrum than in the Cu 2p{sub 3sol2} or S 2p core level spectra, whereas relatively confined reactions at the In/ZnS(001) interface can only be probed in the In 3d{sub 5sol2} core level spectra. The partial densities of states calculated for a reference CuInS{sub 2} on the basis of density functional theory agree well with features occurring in its S L{sub 2,3} emission spectrum.

  5. E-Print Network 3.0 - accurate band gaps Sample Search Results

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

    Technological University Collection: Physics 7 Improving the efficiency of bulk heterojunction solar cells Summary: the amount of photons absorbed by the film by decreasing the...

  6. Hybrid Solar Cells with Prescribed Nanoscale Morphologies Based on Hyperbranched Semiconductor Nanocrystals

    E-Print Network [OSTI]

    Gur, Ilan; Fromer, Neil A.; Chen, Chih-Ping; Kanaras, Antonios G.; Alivisatos, A. Paul

    2006-01-01T23:59:59.000Z

    polymer bulk heterojunction solar cells. Journal of PhysicalS. & Meissner, D. Hybrid solar cells based on nanoparticlesmodelling of organic solar cells: The dependence of internal

  7. Sedimentation stacking diagram of binary colloidal mixtures and bulk phases in the plane of chemical potentials

    E-Print Network [OSTI]

    Daniel de las Heras; Matthias Schmidt

    2014-11-19T23:59:59.000Z

    We give a full account of a recently proposed theory that explicitly relates the bulk phase diagram of a binary colloidal mixture to its phase stacking phenomenology under gravity [Soft Matter 9, 8636 (2013)]. As we demonstrate, the full set of possible phase stacking sequences in sedimentation-diffusion equilibrium originates from straight lines (sedimentation paths) in the chemical potential representation of the bulk phase diagram. From the analysis of various standard topologies of bulk phase diagrams, we conclude that the corresponding sedimentation stacking diagrams can be very rich, even more so when finite sample height is taken into account. We apply the theory to obtain the stacking diagram of a mixture of nonadsorbing polymers and colloids. We also present a catalog of generic phase diagrams in the plane of chemical potentials in order to facilitate the practical application of our concept, which also generalizes to multi component mixtures.

  8. Towards a Unified Picture of Spin Dependent Transport in and Perpendicular Giant Magnetoresistance and Bulk Alloys

    SciTech Connect (OSTI)

    Hsu, S.; Holody, P.; Loloee, R.; Schroeder, P. [Department of Physics, Michigan State University, East Lasing, Michigan 48824 (United States)] [Department of Physics, Michigan State University, East Lasing, Michigan 48824 (United States); Barthelemy, A.; Fert, A. [UMR CNRS-Thomson CSF, LCR, 91404 Orsay (France)] [UMR CNRS-Thomson CSF, LCR, 91404 Orsay (France)

    1997-03-01T23:59:59.000Z

    From data on (Fe{sub 1-x}V{sub x}/Cu/Co/Cu){sub N} multilayers, we show that Fe doped with V gains a negative spin asymmetry for bulk scattering ({beta}{lt}0), which, combined with the positive asymmetry of Co, accounts for the inverse current perpendicular to the plane (CPP) giant magnetoresistance (GMR) we observe. More precisely, the competition between positive and negative asymmetries for interface and bulk scatterings in FeV leads to inverse (normal) GMR for layers thicker (thinner) than a compensation thickness. The negative {beta} of FeV is consistent with theoretical predictions and bulk alloy data. The current in the plane (CIP) GMR is not reversed, which illustrates the role of channeling in CIP. {copyright} {ital 1997} {ital The American Physical Society}

  9. Bulk Flows and End of the Dark Ages with the SKA

    E-Print Network [OSTI]

    Maio, Umberto; Koopmans, Leon V E

    2015-01-01T23:59:59.000Z

    The early Universe is a precious probe of the birth of primordial objects, first star formation events and consequent production of photons and heavy elements. Higher-order corrections to the cosmological linear perturbation theory predicts the formation of coherent supersonic gaseous streaming motions at decoupling time. These bulk flows impact the gas cooling process and determine a cascade effect on the whole baryon evolution. By analytical estimates and N-body hydrodynamical chemistry numerical simulations including atomic and molecular evolution, gas cooling, star formation, feedback effects and metal spreading for individual species from different stellar populations according to the proper yields and lifetimes, we discuss the role of these primordial bulk flows at the end of the dark ages and their detectable impacts during the first Gyr in view of the upcoming SKA mission. Early bulk flows can inhibit molecular gas cooling capabilities, suppressing star formation, metal spreading and the abundance of ...

  10. Spherically symmetric brane spacetime with bulk $f(\\mathcal{R})$ gravity

    E-Print Network [OSTI]

    Sumanta Chakraborty; Soumitra SenGupta

    2015-01-15T23:59:59.000Z

    Introducing $f(\\mathcal{R})$ term in the five-dimensional bulk action we derive effective Einstein's equation on the brane using Gauss-Codazzi equation. This effective equation is then solved for different conditions on dark radiation and dark pressure to obtain various spherically symmetric solutions. Some of these static spherically symmetric solutions correspond to black hole solutions, with parameters induced from the bulk. Specially, the dark pressure and dark radiation terms (electric part of Weyl curvature) affect the brane spherically symmetric solutions significantly. We have solved for one parameter group of conformal motions where the dark radiation and dark pressure terms are exactly obtained exploiting the corresponding Lie symmetry. Various thermodynamic features of these spherically symmetric space-times are studied, showing existence of second order phase transition. This phenomenon has its origin in the higher curvature term with $f(\\mathcal{R})$ gravity in the bulk.

  11. Diffusion of Small He Clusters in Bulk and Grain Boundaries in ?-Fe

    SciTech Connect (OSTI)

    Deng, Huiqiu; Hu, W. Y.; Gao, Fei; Heinisch, Howard L.; Hu, Shenyang Y.; Li, Yulan; Kurtz, Richard J.

    2013-11-02T23:59:59.000Z

    The diffusion properties of He interstitials and He clusters in the bulk and grain boundaries (GBs) of ?-Fe have been studied using molecular dynamics with a newly developed Fe?He potential. The low migration energy barrier for a single He interstitial in the bulk is consistent with that obtained using ab initio methods. Small He clusters can migrate at low temperatures, but at higher temperatures they will kick out a self-interstitial atom (SIA) and become trapped by the vacancy, forming an He-vacancy complex. It is of great interest to note that small Henvacancy clusters (n<5) in the bulk are able to absorb an SIA, and the clusters become mobile again. Trapping and de-trapping of He clusters by emitting and absorbing an SIA represent an important dynamic process that provides a mechanism for the diffusion of He clusters and the nucleation of He bubbles in bulk Fe, particularly under irradiation in which numerous SIAs and vacancies are constantly being produced. A single He interstitial can migrate one-dimensionally or two-dimensionally within GBs, depending on the GB structure. Small interstitial Hen clusters 2 (n ~ 1 - 10) can easily kick out an SIA, and become trapped by the vacancy, while the SIA quickly diffuses away from the clusters, disappearing into the GB, such that de-trapping of the He clusters by absorbing an SIA is less likely to occur. This suggests that small He clusters may be treated as relatively immobile defects in GBs. The different behavior of He clusters in the bulk compared to their behavior in GBs may explain the different He bubble sizes experimentally observed in the bulk and in GBs in reduced activation ferritic/martensitic steels that have been simultaneously neutron irradiated and He implanted.

  12. Evaluation of a probabilistic model for bulk-power system security

    E-Print Network [OSTI]

    Schmidt, William Aloys

    1970-01-01T23:59:59.000Z

    -gower system. By use of this program with appropriate modifications the probabilistic model for any bulk-power system may be evaluated. Management and operator criteria may be derived so that the costs associated with the risk are now deterministic. 32..."UCE Nay 'f970 Major Subjeot: Statistics EVALUATION OF A PROBABILISZIC NGDEL FOR BULK-POWER SYSTEM'4 SE"URITY A Thesis by WILLIAM ALOYS SCMIDT Approved as to style and content by: Chairma of teej 7Head of Department) 7 Lember) Nay tc70 ABSTRACT...

  13. Understanding Bulk Power Reliability: The Importance of Good Data and A Critical Review of Existing Sources

    SciTech Connect (OSTI)

    Fisher, Emily; Eto, Joseph H.; LaCommare, Kristina Hamachi

    2011-10-19T23:59:59.000Z

    Bulk power system reliability is of critical importance to the electricity sector. Complete and accurate information on events affecting the bulk power system is essential for assessing trends and efforts to maintain or improve reliability. Yet, current sources of this information were not designed with these uses in mind. They were designed, instead, to support real-time emergency notification to industry and government first-responders. This paper reviews information currently collected by both industry and government sources for this purpose and assesses factors that might affect their usefulness in supporting the academic literature that has relied upon them to draw conclusions about the reliability of the US electric power system.

  14. Bulk single crystal ternary substrates for a thermophotovoltaic energy conversion system

    DOE Patents [OSTI]

    Charache, G.W.; Baldasaro, P.F.; Nichols, G.J.

    1998-06-23T23:59:59.000Z

    A thermophotovoltaic energy conversion device and a method for making the device are disclosed. The device includes a substrate formed from a bulk single crystal material having a bandgap (E{sub g}) of 0.4 eV < E{sub g} < 0.7 eV and an emitter fabricated on the substrate formed from one of a p-type or an n-type material. Another thermophotovoltaic energy conversion device includes a host substrate formed from a bulk single crystal material and lattice-matched ternary or quaternary III-V semiconductor active layers. 12 figs.

  15. Shubnikov-de Haas Oscillations in the Bulk Rashba Semiconductor BiTeI

    SciTech Connect (OSTI)

    Bell, C.; Bahramy, M.S.; Murakawa, H.; Checkelsky, J.G.; Arita, R.; Kaneko, Y.; Onose, Y.; Nagaosa, N.; Tokura, Y.; Hwang, H.Y.

    2012-07-11T23:59:59.000Z

    Bulk magnetoresistance quantum oscillations are observed in high quality single crystal samples of BiTeI. This compound shows an extremely large internal spin-orbit coupling, associated with the polarity of the alternating Bi, Te, and I layers perpendicular to the c-axis. The corresponding areas of the inner and outer Fermi surfaces around the A-point show good agreement with theoretical calculations, demonstrating that the intrinsic bulk Rashba-type splitting is nearly 360 meV, comparable to the largest spin-orbit coupling generated in heterostructures and at surfaces.

  16. THE EFFECT OF SUBBANDGAP ILLUMINATION ON THE BULK RESISTIVITY OF CDZNTE

    SciTech Connect (OSTI)

    Wright, J.; Washington, A.; Duff, M.; Burger, A.; Groza, M.; Buliga, V.

    2013-08-13T23:59:59.000Z

    The variation in bulk resistivity during infrared (IR) illumination above 950 nm of state-of-the-art CdZnTe (CZT) crystals grown using the traveling heating method or the modified Bridgman method is documented. The change in steady-state current with and without illumination is also evaluated. The influence of secondary phases (SP) on current?voltage (I?V) characteristics is discussed using IR transmission microscopy to determine the defect concentration within the crystal bulk. SP present within the CZT are connected to the existence of deep, IR-excitable traps within the bandgap.

  17. Identification of Bacteria in Biofilm and Bulk Water Samples from a Nonchlorinated Model Drinking Water Distribution System: Detection of a Large Nitrite-Oxidizing Population Associated with Nitrospira spp.

    E-Print Network [OSTI]

    Martiny, A. C; Albrechtsen, H.-J.; Arvin, E.; Molin, S.

    2005-01-01T23:59:59.000Z

    Identification of Bacteria in Biofilm and Bulk Water SamplesNo. 12 Identification of Bacteria in Biofilm and Bulk Water

  18. A General Theorem Relating the Bulk Topological Number to Edge States in Two-dimensional Insulators

    SciTech Connect (OSTI)

    Qi, Xiao-Liang; /Tsinghua U., Beijing /Stanford U., Phys. Dept.; Wu, Yong-Shi; /Utah U.; Zhang, Shou-Cheng; /Stanford U., Phys. Dept. /Tsinghua U., Beijing

    2010-01-15T23:59:59.000Z

    We prove a general theorem on the relation between the bulk topological quantum number and the edge states in two dimensional insulators. It is shown that whenever there is a topological order in bulk, characterized by a non-vanishing Chern number, even if it is defined for a non-conserved quantity such as spin in the case of the spin Hall effect, one can always infer the existence of gapless edge states under certain twisted boundary conditions that allow tunneling between edges. This relation is robust against disorder and interactions, and it provides a unified topological classification of both the quantum (charge) Hall effect and the quantum spin Hall effect. In addition, it reconciles the apparent conflict between the stability of bulk topological order and the instability of gapless edge states in systems with open boundaries (as known happening in the spin Hall case). The consequences of time reversal invariance for bulk topological order and edge state dynamics are further studied in the present framework.

  19. Surface chemistry of bulk nanocrystalline pure iron and electrochemistry study in gas-flow physiological saline

    E-Print Network [OSTI]

    Zheng, Yufeng

    ,9 was about an early failure owing to insufficient strength caused by hydrogen embrittlement or agingSurface chemistry of bulk nanocrystalline pure iron and electrochemistry study in gas. The contact angle test with water and glycerol droplets shows a smaller angle (though >90 ) of NC-Fe than

  20. Complexity of shear localization in a Zr-based bulk metallic glass

    E-Print Network [OSTI]

    University of Aeronautics and Astronautics, Beijing 100191, China The compressive behaviour of a Zr. A significant advance occurred when compositions and copper mold casting method allowing for bulk material the consequence of) macroscopic shear banding remains unclear. It is therefore important to carry out in situ

  1. Complexity of shear localization in a Zr-based bulk metallic glass

    E-Print Network [OSTI]

    University of Aeronautics and Astronautics, Beijing 100191, China The compressive behaviour of a Zr. A significant advance occurred when compositions and copper mold casting method allowing for bulk material unclear. It is therefore important to carry out in situ observations of plastic deformation processes

  2. Stress-corrosion fatiguecrack growth in a Zr-based bulk amorphous metal

    E-Print Network [OSTI]

    Ritchie, Robert

    Stress-corrosion fatigue­crack growth in a Zr-based bulk amorphous metal V. Schroeder 1 , R metallic glass; Amorphous metal; Fatigue; Stress corrosion; Crack growth 1. Introduction In recent years­crack growth resistance [1­5], its corresponding properties in the presence of a corrosive environment have

  3. CORD: Energy-efficient Reliable Bulk Data Dissemination in Sensor Networks

    E-Print Network [OSTI]

    Setia, Sanjeev

    and outdoor sensor network testbed and via extensive simulations. Our results show that in comparisonCORD: Energy-efficient Reliable Bulk Data Dissemination in Sensor Networks Leijun Huang Sanjeev is to minimize energy consumption. To achieve its goals CORD employs a two phase approach in which the object

  4. The efficiency of bulk and fine/flavor cocoa markets: the case of Trinidad and Tobago

    E-Print Network [OSTI]

    Kalloo, Margaret Surujdai

    2002-01-01T23:59:59.000Z

    Time-series methods are used to study the dynamics of bulk and fine/flavor (FF) cocoa bean prices among the markets. The study focuses on establishing where cocoa bean prices are discovered and whether FF cocoa price for Trinidad and Tobago (T...

  5. Bulk-Flow analysis for force and moment coefficients of a shrouded centrifugal compressor impeller

    E-Print Network [OSTI]

    Gupta, Manoj Kumar

    2005-08-29T23:59:59.000Z

    An analysis is developed for a compressible bulk-flow model of the leakage path between a centrifugal compressor's impeller shroud and housing along the front and back side of the impeller. This is an extension of analysis performed first by Childs...

  6. TiN surface dynamics: role of surface and bulk mass transport processes

    E-Print Network [OSTI]

    Khare, Sanjay V.

    TiN surface dynamics: role of surface and bulk mass transport processes J. Bareńoa , S. Kodambakab, USA Abstract. Transition-metal nitrides, such as TiN, have a wide variety of applications as hard/decay kinetics of two- and three-dimensional TiN(111) islands and the effect of surface-terminated dislocations

  7. Mechanical Properties of Bulk Nanocrystalline Austenitic Stainless Steels Produced by Equal Channel Angular Pressing

    E-Print Network [OSTI]

    Gonzalez, Jeremy

    2012-10-19T23:59:59.000Z

    Bulk nanocrystalline 304L and 316L austenitic stainless steels (SS) were produced by equal channel angular pressing(ECAP) at elevated temperature. The average grain size achieved in 316L and 304 L SS is ~ 100 nm, and grain refinement occurs more...

  8. BULK VITRIFICATION TECHNOLOGY FOR THE TREATMENT AND IMMOBILIZATION OF LOW-ACTIVITY WASTE

    SciTech Connect (OSTI)

    ARD KE

    2011-04-11T23:59:59.000Z

    This report is one of four reports written to provide background information regarding immobilization technologies under consideration for supplemental immobilization of Hanford's low-activity waste. This paper is intended to provide the reader with general understanding of Bulk Vitrification and how it might be applied to immobilization of Hanford's low-activity waste.

  9. Climatic features of the Mediterranean Sea detected by the analysis of the longwave radiative bulk formulae

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    an open ocean with the same amount of net longwave radiation. Furthermore, the twofold climatic regime's climate system is the net radiation budget at the ocean surface. Due to the scarcity of direct radiationClimatic features of the Mediterranean Sea detected by the analysis of the longwave radiative bulk

  10. Attrition resistant bulk iron catalysts and processes for preparing and using same

    DOE Patents [OSTI]

    Jothimurugesan, Kandaswamy (Ponca City, OK); Goodwin, Jr., James G. (Clemson, SC); Gangwal, Santosh K. (Cary, NC)

    2007-08-21T23:59:59.000Z

    An attrition resistant precipitated bulk iron catalyst is prepared from iron oxide precursor and a binder by spray drying. The catalysts are preferably used in carbon monoxide hydrogenation processes such as Fischer-Tropsch synthesis. These catalysts are suitable for use in fluidized-bed reactors, transport reactors and, especially, slurry bubble column reactors.

  11. Matrix penetration in the bulk:In uence of humidity: Morphological analysis of wood welding

    E-Print Network [OSTI]

    Dalang, Robert C.

    Matrix penetration in the bulk:In uence of humidity: Morphological analysis of wood welding.pichelin@b .ch Context: Wood can be welded using linear vibration welding tech- niques similar to the ones in plastic and metal industry[1] . Wood welding allows bonding strength similar to glued joints. However, due

  12. On the Conversion of Bulk Polycrystalline Y2O3 into the Nanocrystalline State

    E-Print Network [OSTI]

    Tse, Stephen D.

    On the Conversion of Bulk Polycrystalline Y2O3 into the Nanocrystalline State Bernard H. Kear. Voronov Diamond Materials Inc., Piscataway, New Jersey 08854 Christopher S. Nordahl Raytheon IDS, Andover polycrystalline Y2O3 directly into the nanocrystalline state. The process involves a forward transfor- mation from

  13. Excitonic recombinations in hBN: from bulk to exfoliated layers A. Pierret,1, 2

    E-Print Network [OSTI]

    Excitonic recombinations in hBN: from bulk to exfoliated layers A. Pierret,1, 2 J. Loayza,1, 3 B mechanically exfoliated from them. First the link between the presence of structural defects-BN thickness was reduced down to six atomic layers, using mechanical exfoliation, as evidenced by atomic force

  14. Spatio-Temporal Ultrafast Laser Tailoring for Bulk Functionalization of Transparent Materials

    E-Print Network [OSTI]

    of bulk photowriting of light guides, the con- trol of the irradiation outcome and the machining of more that the domain of photowriting can be extended to deep focusing despite of the associated optical distortions optimization loop based on the evaluation of the irradiation outcome in fused silica and borosilicate Crown

  15. Observation of second-phase particles in bulk zirconium alloys using synchrotron radiation q

    E-Print Network [OSTI]

    Motta, Arthur T.

    of second-phase precipitates present in the bulk alloys as a function of the heat treatment and irradiation composition, thermo- mechanical treatment, and irradiation dose. For exam- ple, a beta-quench heat treatment depending on the beam optics) and energy- tunable capability. The increased ÂŻux density allows www

  16. metry and conventional radiocarbon dating of bulk peat samples from the lowest visually apparent peat

    E-Print Network [OSTI]

    Gillespie, Rosemary

    #12;metry and conventional radiocarbon dating of bulk peat samples from the lowest visually apparent peat horizon in each core. Substantially older radiocarbon ages from organic-rich gytjja (mineral peat- lands throughout the WSL, for a total of 29,350 measurements digitized. (ii) Our own field data

  17. The Economic Implications of Adding Wind Capacity to a Bulk Power Transmission Network

    E-Print Network [OSTI]

    The Economic Implications of Adding Wind Capacity to a Bulk Power Transmission Network by Tim Mount, these are precisely the prices that must be determined correctly to measure the economic value of equipment the economic value of improved reliability. The objective of this paper is to extend the co

  18. The Economic Value of Improving the Reliability of Supply on a Bulk Power Transmission Network

    E-Print Network [OSTI]

    The Economic Value of Improving the Reliability of Supply on a Bulk Power Transmission Network Economics and Management and School of Electrical and Computer Engineering Cornell University Abstract, there is no established way of measuring the economic value of reliability, and as a result, regulators have adopted

  19. Neutrino emissivity and bulk viscosity of iso-CSL quark matter in neutron stars

    E-Print Network [OSTI]

    David B. Blaschke; Jens Berdermann

    2007-10-27T23:59:59.000Z

    We present results for neutrino emissivities and bulk viscosities of a two-flavor color superconducting quark matter phase with isotropic color-spin-locked (iso-CSL) single-flavor pairing which fulfill the constraints on quark matter derived from cooling and rotational evolution of compact stars. We compare with results for the phenomenologically successful, but yet heuristic 2SC+X phase.

  20. Influence of Time-Varying External Magnetic Fields on Trapped Fields in Bulk Superconductors

    E-Print Network [OSTI]

    Zou, Jin; Ainslie, Mark D.; Hu, Di; Cardwell, David A.

    2014-12-12T23:59:59.000Z

    Large, single-grain bulk high-temperature superconductors (HTS) can trap magnetic fields over 17 T below 30 K and up to 3 T at 77 K, and have significant potential to replace permanent magnets, the fields from which are limited to significantly less...

  1. Mechanically flexible thin-film transistors that use ultrathin ribbons of silicon derived from bulk wafers

    E-Print Network [OSTI]

    Rogers, John A.

    , and on/off ratios were 103 . These results may represent important steps toward a low-cost approach thicknesses derived from low-cost bulk Si 111 wafers. We begin with a description of the procedures for fabricating these structures and transfer printing them onto plastic sub- strates via elastomeric stamps. We

  2. Bulk nanocomposite magnets produced by dynamic shock compaction K. H. Chen and Z. Q. Jin

    E-Print Network [OSTI]

    Wang, Zhong L.

    single-phaselike behavior, indicating effective exchange coupling between hard and soft magnetic phases. © 2004 American Institute of Physics. DOI: 10.1063/1.1760834 The figure of merit for a permanent magnet of bulk exchange-coupled nanocomposite magnets still remains a great challenge. Shock compaction employs

  3. Design of Bulk Railway Terminals for the Shale Oil and Gas Industry C. Tyler Dick1

    E-Print Network [OSTI]

    Barkan, Christopher P.L.

    Page 1 Design of Bulk Railway Terminals for the Shale Oil and Gas Industry C. Tyler Dick1 , P.E., M: Railway transportation is playing a key role in the development of many new shale oil and gas reserves in North America. In the rush to develop new shale oil and gas plays, sites for railway transload terminals

  4. A GIS-based Hydraulic Bulking Factor Map for New Mexico Gallegos, J.B.1

    E-Print Network [OSTI]

    Cal, Mark P.

    1 A GIS-based Hydraulic Bulking Factor Map for New Mexico Gallegos, J.B.1 ; Richardson, C and Environmental Engineering, New Mexico Tech, 801 Leroy Place Socorro, NM, 87801, joeyg@nmt.edu 2 Clinton P. Richardson, P.E., BCEE, Professor, Dept. of Civil and Environmental Engineering, New Mexico Tech 801 Leroy

  5. Correlation between corrosion performance and surface wettability in ZrTiCuNiBe bulk metallic glasses

    E-Print Network [OSTI]

    Zheng, Yufeng

    Correlation between corrosion performance and surface wettability in ZrTiCuNiBe bulk metallic June 2010 The corrosion properties of two Zr-based bulk metallic glass, Zr41Ti14Cu12Ni10Be23 LM1 and Zr potential, LM1b showed superior corrosion resistance to LM1. Under identical sample preparation and testing

  6. Water in a Crowd In many situations, form biology to geology, water occurs not as the pure bulk

    E-Print Network [OSTI]

    Fayer, Michael D.

    Water in a Crowd In many situations, form biology to geology, water occurs not as the pure bulk species, and interacting with large organic molecules. In such situations, water does not behave in the same manner as it does in the pure bulk liquid. Water dynamics are fundamental to many processes

  7. Abstract--Temperature, current density and magnetic field distributions in YBCO bulk superconductor during a pulsed-field

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    -- bulk YBaCuO, stored magnetic energy, thermal coupling, magnetization, modelling. I. INTRODUCTION HE as cryo-permanent magnets [1], [2]. To magnetize the HTS, pulsed field magnetization (PFM) process1 Abstract-- Temperature, current density and magnetic field distributions in YBCO bulk

  8. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 13, NO. 6, DECEMBER 2004 1043 VHF Single-Crystal Silicon Elliptic Bulk-Mode

    E-Print Network [OSTI]

    Ayazi, Farrokh

    - mechanical coupling, elliptic bulk-mode, equivalent electrical circuit, temperature coefficient of frequency-plane vibrations of the disk struc- tures is described using the two-dimensional (2-D) elastic theory. An equivalent mechanical model is extracted from the elliptic bulk-mode shape to predict the dynamic behavior

  9. Photocatalytic Activity of Bulk TiO{sub 2} Anatase and Rutile Single Crystals Using Infrared Absorption Spectroscopy

    SciTech Connect (OSTI)

    Xu Mingchun; Gao Youkun [Department of Physical Chemistry I, Ruhr-Universitaet Bochum, 44780 (Germany); Moreno, Elias Martinez; Kunst, Marinus [Hahn-Meitner-Institut, Glienicker Strasse 100, D-1000 Berlin 39 (Germany); Muhler, Martin [Laboratory of Industrial Chemistry, Ruhr-Universitaet Bochum, 44780 (Germany); Wang Yuemin [Department of Physical Chemistry I, Ruhr-Universitaet Bochum, 44780 (Germany); Laboratory of Industrial Chemistry, Ruhr-Universitaet Bochum, 44780 (Germany); Idriss, Hicham [Department of Chemistry, University of Aberdeen and School of Engineering, Robert Gordon University, AB24 3EU Aberdeen, Scotland (United Kingdom); Woell, Christof [Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), 76021 Karlsruhe (Germany)

    2011-04-01T23:59:59.000Z

    A systematic study on the photocatalytic activity of well-defined, macroscopic bulk single-crystal TiO{sub 2} anatase and rutile samples has been carried out, which allows us to link photoreactions at surfaces of well-defined oxide semiconductors to an important bulk property with regard to photochemistry, the life time of e-h pairs generated in the bulk of the oxides by photon absorption. The anatase (101) surface shows a substantially higher activity, by an order of magnitude, for CO photo-oxidation to CO{sub 2} than the rutile (110) surface. This surprisingly large difference in activity tracks the bulk e-h pair lifetime difference for the two TiO{sub 2} modifications as determined by contactless transient photoconductance measurements on the corresponding bulk materials.

  10. A quantum dot heterojunction photodetector

    E-Print Network [OSTI]

    Arango, Alexi Cosmos, 1975-

    2005-01-01T23:59:59.000Z

    This thesis presents a new device architecture for photodetectors utilizing colloidally grown quantum dots as the principle photo-active component. We implement a thin film of cadmium selenide (CdSe) quantum dot sensitizers, ...

  11. Surface and bulk modified high capacity layered oxide cathodes with low irreversible capacity loss

    DOE Patents [OSTI]

    Manthiram, Arumugam (Austin, TX); Wu, Yan (Austin, TX)

    2010-03-16T23:59:59.000Z

    The present invention includes compositions, surface and bulk modifications, and methods of making of (1-x)Li[Li.sub.1/3Mn.sub.2/3]O.sub.2.xLi[Mn.sub.0.5-yNi.sub.0.5-yCo.sub.2- y]O.sub.2 cathode materials having an O3 crystal structure with a x value between 0 and 1 and y value between 0 and 0.5, reducing the irreversible capacity loss in the first cycle by surface modification with oxides and bulk modification with cationic and anionic substitutions, and increasing the reversible capacity to close to the theoretical value of insertion/extraction of one lithium per transition metal ion (250-300 mAh/g).

  12. Synthesis and characterization of bulk and coatings of hydroxyapatite using methanol precursor

    SciTech Connect (OSTI)

    Khongwar, Jasper K. [Chemistry Division, School of Science and Humanities, Vellore Institute of Technology University, Vellore 632014, Tamil Nadu (India); Kannan, K.R. [SSCU, Indian Institute of Science, Bangalore 560012 (India); Buvaneswari, G. [Chemistry Division, School of Science and Humanities, Vellore Institute of Technology University, Vellore 632014, Tamil Nadu (India)], E-mail: gopalbhu@yahoo.com

    2008-02-05T23:59:59.000Z

    Hydroxyapatite, an important bioceramic was synthesized in the bulk form and developed as a coating by a sol-gel route using alcoholic precursor. The bioactive coating was developed on bio-inert {alpha}-alumina and yttria stabilized zirconia substrates. The apatite phase began to form after the heat treatment of the precursor at 500 deg. C for 10 min. The complete crystallization of the apatite was obtained at 800 deg. C heat treatment for 10 min. The phase composition of the bulk and the coatings was identified by FT-IR spectroscopic and powder X-ray diffraction (XRD) techniques. Surface morphology was determined by scanning electron microscopy. The study indicates different surface textures for the powder and for the coatings on {alpha}-alumina and yttria stabilized zirconia substrates.

  13. Intense femtosecond photoexcitation of bulk and monolayer MoS2

    E-Print Network [OSTI]

    Paradisanos, I; Fotakis, C; Kioseoglou, G; Stratakis, E

    2015-01-01T23:59:59.000Z

    The effect of femtosecond laser irradiation on bulk and single-layer MoS2 on silicon oxide is studied. Optical, Field Emission Scanning Electron Microscopy (FESEM) and Raman microscopies were used to quantify the damage. The intensity of A1g and E2g1 vibrational modes was recorded as a function of the number of irradiation pulses. The observed behavior was attributed to laser-induced bond breaking and subsequent atoms removal due to electronic excitations. The single-pulse optical damage threshold was determined for the monolayer and bulk under 800nm and 1030nm pulsed laser irradiation and the role of two-photon versus one photon absorption effects is discussed.

  14. CALCULATION OF DEMONSTRATION BULK VITRIFICATION SYSTEM MELTER INLEAKAGE AND OFF-GAS GENERATION RATE

    SciTech Connect (OSTI)

    MAY TH

    2008-04-16T23:59:59.000Z

    The River Protection Project (RPP) mission is to safely store, retrieve, treat, immobilize, and dispose of the Hanford Site tank waste. The Demonstration Bulk Vitrification System (DBVS) is a research and development project whose objective is to demonstrate the suitability of Bulk Vitrification treatment technology waste form for disposing of low-activity waste from the Tank Farms. The objective of this calculation is to determine the DBVS melter inleakage and off-gas generation rate based on full scale testing data from 38D. This calculation estimates the DBVS melter in leakage and gas generation rate based on test data. Inleakage is estimated before the melt was initiated, at one point during the melt, and at the end of the melt. Maximum gas generation rate is also estimated.

  15. Report on Analysis of Forest Floor Bulk Density and Depth at the Savannah River Site.

    SciTech Connect (OSTI)

    Bernard R. Parresol

    2005-10-01T23:59:59.000Z

    The forest floor data from the Savannah River Site consists of two layers, the litter layer and the duff layer. The purpose for the study was to determine bulk density conversion factors to convert litter and duff depth values in inches to forest floor fuel values in tons per acre. The primary objective was to collect litter and duff samples to adequately characterize forest floor depth and bulk density for combinations of 4 common forest types (loblolly/slash pine, longleaf pine, pine and hardwood mix, upland hardwood), 3 age classes (5-20, 20-40, 40+ years old) and 3 categories of burning history (0-3, 3-10, 10+ years since last burn).

  16. Atomistic calculation of the thermal conductance of large scale bulk-nanowire junctions

    SciTech Connect (OSTI)

    Duchemin, Ivan; Donadio, Davide [Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz (Germany)

    2011-09-15T23:59:59.000Z

    We have developed a stable and efficient kernel method to compute thermal transport in open systems, based on the scattering-matrix approach. This method is applied to compute the thermal conductance of a junction between bulk silicon and silicon nanowires with diameter up to 10 nm. We have found that beyond a threshold diameter of 7 nm, transmission spectra and contact conductances scale with the cross section of the contact surface, whereas deviations from this general trend are observed in thinner wires. This result allows us to predict the thermal resistance of bulk-nanowire interfaces with larger cross sections than those tractable with atomistic simulations, and indicate the characteristic size beyond which atomistic systems can in principle be treated accurately by mean-field theories. Our calculations also elucidate how dimensionality reduction and shape affect interfacial heat transport.

  17. Bulk Gold-Catalyzed Reactions of Isocyanides, Amines, and Amine N-Oxides

    SciTech Connect (OSTI)

    Klobukowski, Erik; Angelici, Robert; Woo, Keith L.

    2012-01-26T23:59:59.000Z

    Bulk gold powder (5–50 ?m particles) catalyzes the reactions of isocyanides with amines and amine N-oxides to produce ureas. The reaction of n-butyl isocyanide (nBu–N?C) with di-n-propylamine and N-methylmorpholine N-oxide in acetonitrile, which was studied in the greatest detail, produced 3-butyl-1,1-dipropylurea (O?C(NHnBu)(NnPr2)) in 99% yield at 60 °C within 2 h. Sterically and electronically different isocyanides, amines, and amine N-oxides react successfully under these conditions. Detailed studies support a two-step mechanism that involves a gold-catalyzed reaction of adsorbed isocyanide with the amine N-oxide to form an isocyanate (RN?C?O), which rapidly reacts with the amine to give the urea product. These investigations show that bulk gold, despite its reputation for poor catalytic activity, is capable of catalyzing these reactions.

  18. Nanostructured materials for lithium-ion batteries: Surface conductivity vs. bulk

    E-Print Network [OSTI]

    Ryan, Dominic

    Nanostructured materials for lithium-ion batteries: Surface conductivity vs. bulk ion cathode materials for high capacity lithium-ion batteries. Owing to their inherently low electronic-ion batteries. Lithium transition metal phosphates such as LiFePO4,1 LiMnPO4,2 Li3V2(PO4)3 3 and LiVPO4F4 have

  19. Surface Science Letters Bulk-defect dependent adsorption on a metal oxide surface

    E-Print Network [OSTI]

    Diebold, Ulrike

    -6028(01)01067-6 #12;Titanium dioxide is a wide-band gap semicon- ductor (Egap 3 eV) that can easily be reducedSurface Science Letters Bulk-defect dependent adsorption on a metal oxide surface: S/TiO2(1 1 0) E Abstract The adsorption of molecular sulfur on TiO2(1 1 0)(1 Ă? 1) has been studied with scanning tunneling

  20. Oxygen impurity and microalloying effect in a Zr-based bulk metallic glass alloy

    E-Print Network [OSTI]

    Pennycook, Steve

    Oxygen impurity and microalloying effect in a Zr-based bulk metallic glass alloy C.T. Liu*, M composition Zr­10 at.%Al­5% Ti­17.9% Cu­14.6% Ni (BAM-11) was used to study the effects of oxygen impurities and microalloying on the microstructure and mechanical properties. Oxygen impurity at a level of 3000 appm

  1. Impact of Improved Solar Forecasts on Bulk Power System Operations in ISO-NE (Presentation)

    SciTech Connect (OSTI)

    Brancucci Martinez-Anido, C.; Florita, A.; Hodge, B.M.

    2014-11-01T23:59:59.000Z

    The diurnal nature of solar power is made uncertain by variable cloud cover and the influence of atmospheric conditions on irradiance scattering processes. Its forecasting has become increasingly important to the unit commitment and dispatch process for efficient scheduling of generators in power system operations. This presentation is an overview of a study that examines the value of improved solar forecasts on Bulk Power System Operations.

  2. Bulk optical damage thresholds for doped and undoped, crystalline and ceramic yttrium aluminum garnet

    SciTech Connect (OSTI)

    Do, Binh T.; Smith, Arlee V.

    2009-06-20T23:59:59.000Z

    We measured the bulk optical damage thresholds of pure and Nd-doped ceramic yttrium aluminum garnet (YAG), and of pure, Nd-doped, Cr-doped, and Yb-doped crystalline YAG. We used 9.9 ns, 1064 nm, single-longitudinal mode, TEM00 pulses, to determine that the breakdown thresholds are deterministic, with multiple-pulse thresholds ranging from 1.1 to 2.2 kJ/cm{sup 2}.

  3. Remarks Concerning the Public Utility Commission of Texas Study on Bulk Power Transmission

    E-Print Network [OSTI]

    Sweatman, R. T.

    REMARKS CONCERNING THE PUBLIC UTILITY COMMISSION OF TEXAS STUDY ON BULK POWER TRANSMISSION R. T. SWEATMAN Executive Director Electric Reliability Council of Texas The citizens of Texas need reliable electric service. Our economy, our way... amounts of transmission capacity must alwavs be available in the event generation is lost in one area, so that the other utility's power can be transmitted to the utility in need. A pipeline system can suffer equipment outages easily, without loss...

  4. Bulk Migration of Ni/NiO in Ni-YSZ during Reducing Conditions

    SciTech Connect (OSTI)

    Saraf, Laxmikant V.; Baer, Donald R.; Lea, Alan S.; Zhu, Zihua; Strohm, James J.; Sitzman, S. D.; King, David L.

    2010-02-09T23:59:59.000Z

    Understanding the migration of Ni/NiO in Ni-YSZ can potentially help to design a better solid oxide fuel cell (SOFC) anode. We have observed that extensive hydrogen reduction and methane steam reforming of Ni-YSZ caused bulk migration of Ni/NiO to at least ~ 5 µm deeper from the Ni-YSZ surface. No significant bulk migration effects were detected after simple thermal treatments in non-reducing/non-reforming environment. Surface analysis of a single zirconia grain in the first 10-20 nm region from annealed, hydrogen reduced and methane steam reformed Ni-YSZ shows Ni-enriched surface supporting earlier claims of Ni exsolution. 3D-EBSD analysis of thermally treated sample before exposing it to reducing and reforming environment indicated mixed NiO/YSZ phase with some porosity and random grain orientation. The surface analysis and mapping were carried out using ToF-SIMS and AES whereas EDS maps on FIB sliced areas on Ni-YSZ were utilized for the bulk analysis. The results provide additional information related to complex reactions occurring in SOFC during internal reforming conditions.

  5. Laser Measurement of SAM Bulk and Surface Wave Amplitudes for Material Microstructure Analysis

    SciTech Connect (OSTI)

    Ken L. Telschow; Chiaki Miyasaka; David L. Cottle

    2005-07-01T23:59:59.000Z

    Scanning Acoustic Microscopy (SAM) at ultra high frequencies has proven to be a useful tool for investigating materials on the scale of individual grains. This technique is normally performed in a reflection mode from one side of a sample surface. Information about the generation and transmission of bulk acoustic waves into the material is inferred from the reflection signal amplitude. We present an adaptation to the SAM method whereby the acoustic bulk waves are directly visualized through laser acoustic detection. Ultrasonic waves were emitted from a nominal 200 MHz point focus acoustic lens into a thin silicon plate (thickness 75ěm) coupled with distilled water. A scanned laser beam detected the bulk and surface acoustic waves at the opposite surface of the thin silicon plate. Distinct amplitude patterns exhibiting the expected symmetry for Silicon were observed that alter in predictable ways as the acoustic focal point was moved throughout the plate. Predictions of the acoustic wave fields generated by the acoustic lens within and at the surface of the Silicon are being investigated through the angular spectrum of plane waves approach. Results shall be presented for plates with (100) and (111) orientations followed by discussion of applications of the technique for material microstructure analysis.

  6. Effect of bulk viscosity in low density, hypersonic blunt body flows

    SciTech Connect (OSTI)

    Rutledge, W.H. (Sandia National Labs., Albuquerque, NM (USA)); Hoffmann, K.A. (Texas Univ., Austin, TX (USA))

    1991-01-01T23:59:59.000Z

    A computational fluids dynamics scheme is presented to solve the unsteady Thin-Layer Navier-Stokes (TLNS) equations over a blunt body at high altitude, high Mach number atmospheric reentry flow conditions. This continuum approach is directed to low density hypersonic flows by accounting for non-zero bulk viscosity effects in near frozen flow conditions. The TLNS equations are solved over an axisymmetric body at zero incidence relative to the free stream. The time dependent axisymmetric governing equations are transformed into a computational plane, then cast into weak conservative form and solved using a first-order fully implicit scheme in time with second-order flux vector splitting for spatial derivatives. The physical domain is defined over representative sphere and sphere/cone geometries using a body-fitted clustered algebraic grid within a fixed domain (i.e., shock capturing). At the present time, nonequilibrium thermo-chemistry effects are not modeled. Catalytic wall, ionization and radiation effects are also excluded from the current analysis. However, the significant difference from previous studies is the inclusion of the capability to model non-zero bulk viscosity effects. The importance of bulk viscosity is reviewed and blunt body flow field solutions are presented to illustrate the potential contribution of this phenomena at high altitude hypersonic conditions. The current technique is compared with experimental data and other approximate continuum solutions. A variety of test cases are also presented for a wide range of free stream Mach conditions. 18 refs., 42 figs.

  7. Low-energy effective theory for a Randall-Sundrum scenario with a moving bulk brane

    SciTech Connect (OSTI)

    Cotta-Ramusino, Ludovica [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, P01 2EG (United Kingdom); Laboratory for Computation and Visualization in Mathematics and Mechanics, EPFL FSB IMB, Ecole Polytechnique Federale de Lausanne, CH-1015 (Switzerland); Wands, David [Institute of Cosmology and Gravitation, University of Portsmouth, Portsmouth, P01 2EG (United Kingdom)

    2007-05-15T23:59:59.000Z

    We derive the low-energy effective theory of gravity for a generalized Randall-Sundrum scenario, allowing for a third self-gravitating brane to live in the 5D bulk spacetime. At zero order the 5D spacetime is composed of two slices of anti-de Sitter spacetime, each with a different curvature scale, and the 5D Weyl tensor vanishes. Two boundary branes are at the fixed points of the orbifold whereas the third brane is free to move in the bulk. At first order, the third brane breaks the otherwise continuous evolution of the projection of the Weyl tensor normal to the branes. We derive a junction condition for the projected Weyl tensor across the bulk brane, and combining this constraint with the junction condition for the extrinsic curvature tensor, allows us to derive the first-order field equations on the middle brane. The effective theory is a generalized Brans-Dicke theory with two scalar fields. This is conformally equivalent to Einstein gravity and two scalar fields, minimally coupled to the geometry, but nonminimally coupled to matter on the three branes.

  8. Macroscopic Properties of Restacked, Redox-Liquid Exfoliated Graphite and Graphite Mimics Produced in Bulk Quantities

    SciTech Connect (OSTI)

    Srivastava, Vikram K [ORNL; Quinlan, Ronald [ORNL; Agapov, Alexander L [ORNL; Dunlap, John R [ORNL; Nelson, Kimberly M [ORNL; Duranty, Edward R [ORNL; Sokolov, Alexei P [ORNL; Bhat, Gajanan [ORNL; Mays, Jimmy [ORNL

    2014-01-01T23:59:59.000Z

    The excellent properties exhibited by monolayer graphene have spurred the development of exfoliation techniques using bulk graphite to produce large quantities of pristine monolayer sheets. Development of simple chemistry to exfoliate and intercalate graphite and graphite mimics in large quantities is required for numerous applications. To determine the macroscopic behavior of restacked, exfoliated bulk materials, a systematic approach is presented using a simple, redox-liquid sonication process along to obtain large quantities of 2D and 3D hexagonally layered graphite, molybdenum disulfi de, and boron nitride, which are subsequently characterized to observe chemical and structural changes. For MoS 2 sonicated with the antioxidant sodium bisulfi te, results from Raman spectroscopy, X-ray diffraction, and electron microscopy indicate the presence of distorted phases from different polymorphs, and apparent nanotube structures in the bulk, restacked powder. Furthermore, using thermograviemtric analysis, the antioxidant enhances the resistance to oxidative degradation of MoS 2 , upon thermal treatment up to 900 C. The addition of the ionic antioxidant decreased dispersion stability in non-polar solvent, suggesting decreased compatibility with non-polar systems. Using simple chemical methods, the ability to generate tailored multidimensional layered materials with unique macroscopic properties is critical for numerous applications, including electrical devices, reinforced polymer composites, lithium ion capacitors, and chemical sensing.

  9. Probing bulk viscous matter-dominated models with Gamma-ray bursts

    E-Print Network [OSTI]

    A. Montiel; N. Bretón

    2011-07-01T23:59:59.000Z

    In this paper we extend the range of consistency of a constant bulk viscosity model to redshifts up to $z\\sim 8.1$. In this model the dark sector of the cosmic substratum is a viscous fluid with pressure $p= -\\zeta \\theta$, where $\\theta$ is the fluid-expansion scalar and $\\zeta$ is the coefficient of bulk viscosity. Using the sample of 59 high-redshift GRBs reported by Wei (2010), we calibrate GRBs at low redshifts with the Union 2 sample of SNe Ia, avoiding then the circularity problem. Testing the constant bulk viscosity model with GRBs we found the best fit for the viscosity parameter $\\tilde{\\zeta}$ in the range $0<\\tilde{\\zeta}<3$, being so consistent with previous probes; we also determined the deceleration parameter $q_0$ and the redshift of transition to accelerated expansion. Besides we present an updated analysis of the model with CMB5-year data and CMB7-year data, as well as with the baryon acoustic peak BAO. From the statistics with CMB it turns out that the model does not describe in a feasible way the far far epoch of recombination of the universe, but is in very good concordance for epochs as far as $z\\sim 8.1$ till present.

  10. ENVIRONMENTAL SAMPLING USING LOCATION SPECIFIC AIR MONITORING IN BULK HANDLING FACILITIES

    SciTech Connect (OSTI)

    Sexton, L.; Hanks, D.; Degange, J.; Brant, H.; Hall, G.; Cable-Dunlap, P.; Anderson, B.

    2011-06-07T23:59:59.000Z

    Since the introduction of safeguards strengthening measures approved by the International Atomic Energy Agency (IAEA) Board of Governors (1992-1997), international nuclear safeguards inspectors have been able to utilize environmental sampling (ES) (e.g. deposited particulates, air, water, vegetation, sediments, soil and biota) in their safeguarding approaches at bulk uranium/plutonium handling facilities. Enhancements of environmental sampling techniques used by the IAEA in drawing conclusions concerning the absence of undeclared nuclear materials or activities will soon be able to take advantage of a recent step change improvement in the gathering and analysis of air samples at these facilities. Location specific air monitoring feasibility tests have been performed with excellent results in determining attribute and isotopic composition of chemical elements present in an actual test-bed sample. Isotopic analysis of collected particles from an Aerosol Contaminant Extractor (ACE) collection, was performed with the standard bulk sampling protocol used throughout the IAEA network of analytical laboratories (NWAL). The results yielded bulk isotopic values expected for the operations. Advanced designs of air monitoring instruments such as the ACE may be used in gas centrifuge enrichment plants (GCEP) to detect the production of highly enriched uranium (HEU) or enrichments not declared by a State. Researchers at Savannah River National Laboratory in collaboration with Oak Ridge National Laboratory are developing the next generation of ES equipment for air grab and constant samples that could become an important addition to the international nuclear safeguards inspector's toolkit. Location specific air monitoring to be used to establish a baseline environmental signature of a particular facility employed for comparison of consistencies in declared operations will be described in this paper. Implementation of air monitoring will be contrasted against the use of smear ES when used during unannounced inspections, design information verification, limited frequency unannounced access, and complementary access visits at bulk handling facilities. Analysis of technical features required for tamper indication and resistance will demonstrate the viability of successful application of the system in taking ES within a bulk handling location. Further exploration of putting this technology into practice is planned to include mapping uranium enrichment facilities for the identification of optimal for installation of air monitoring devices.

  11. Ultraviolet laser-induced poling inhibition produces bulk domains in MgO-doped lithium niobate crystals

    SciTech Connect (OSTI)

    Boes, Andreas, E-mail: s3363819@student.rmit.edu.au; Steigerwald, Hendrik; Sivan, Vijay; Mitchell, Arnan [School of Electrical and Computer Engineering, RMIT University, Melbourne, Victoria 3001 (Australia); ARC Center for Ultra-high Bandwidth Devices for Optical Systems (CUDOS), RMIT University, Melbourne, Victoria 3001 (Australia); Yudistira, Didit [School of Electrical and Computer Engineering, RMIT University, Melbourne, Victoria 3001 (Australia); Wade, Scott [Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, Victoria 3122 (Australia); Mailis, Sakellaris [Optoelectronics Research Centre, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Soergel, Elisabeth [Institute of Physics, University of Bonn, Wegelerstr. 8, 53115 Bonn (Germany)

    2014-09-01T23:59:59.000Z

    We report the realization of high-resolution bulk domains achieved using a shallow, structured, domain inverted surface template obtained by UV laser-induced poling inhibition in MgO-doped lithium niobate. The quality of the obtained bulk domains is compared to those of the template and their application for second harmonic generation is demonstrated. The present method enables domain structures with a period length as small as 3??m to be achieved. Furthermore, we propose a potential physical mechanism that leads to the transformation of the surface template into bulk domains.

  12. Brane world solutions of perfect fluid in the background of a bulk containing dust or cosmological constant

    E-Print Network [OSTI]

    Tanwi Bandyopadhyay; Subenoy Chakraborty; Asit Banerjee

    2006-09-18T23:59:59.000Z

    The paper presents some solutions to the five dimensional Einstein equations due to a perfect fluid on the brane with pure dust filling the entire bulk in one case and a cosmological constant (or vacuum) in the bulk for the second case. In the first case, there is a linear relationship between isotropic pressure, energy density and the brane tension, while in the second case, the perfect fluid is assumed to be in the form of chaplygin gas. Cosmological solutions are found both for brane and bulk scenarios and some interesting features are obtained for the chaplygin gas on the brane which are distinctly different from the standard cosmology in four dimensions.

  13. In vitro corrosion, cytotoxicity and hemocompatibility of bulk nanocrystalline pure iron This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Zheng, Yufeng

    In vitro corrosion, cytotoxicity and hemocompatibility of bulk nanocrystalline pure iron:10.1088/1748-6041/5/6/065015 In vitro corrosion, cytotoxicity and hemocompatibility of bulk and electrochemical corrosion in simulated body fluid, cellular responses and hemocompatibility were investigated

  14. Selective Probing of Photoinduced Charge and Spin Dynamics in the Bulk and Surface of a Topological Insulator

    E-Print Network [OSTI]

    Hsieh, David

    Topological insulators possess completely different spin-orbit coupled bulk and surface electronic spectra that are each predicted to exhibit exotic responses to light. Here we report time-resolved fundamental and second ...

  15. Bulk chemicals from biomass Jacco van Haveren, Agrotechnology and Food Innovations B.V., Wageningen, The Netherlands

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    41 Review Bulk chemicals from biomass Jacco van Haveren, Agrotechnology and Food Innovations B production, and available biomass conversion technologies, biomass-based routes are expected to make and -caprolactam. Technologies involving direct isolation of aromatic building blocks from biomass

  16. Electronic States and Optical Transitions in Bulk and Quantum Well Structures of III-V Compound Semiconductors

    E-Print Network [OSTI]

    Cho, Yong Hee 1976-

    2011-05-06T23:59:59.000Z

    In this work we apply the methods of band structure calculation combined with self-consistent treatment of the light-matter interaction to a variety of problems in bulk semiconductors and semiconductor heterostructures as well as in new...

  17. Critical analysis of plume containment modeling in a thin heterogeneous unconfined aquifer: application to a bulk fuel storage terminal

    E-Print Network [OSTI]

    Mejia, Karl Edward

    1997-01-01T23:59:59.000Z

    The reported hydrocarbon contamination and subsequent consultant work at a bulk fuel storage terminal has instigated the need to critically analyze modeling techniques in thin, heterogeneous, unconfined aquifers. This study provides an aquifer...

  18. Prevalence and spatial distribution of antibodies to Salmonella enterica serovar Typhimurium O antigens in bulk milk from Texas dairy herds.

    E-Print Network [OSTI]

    Graham, Sherry Lynn

    2004-09-30T23:59:59.000Z

    The purpose of this study was to describe the herd antibody status to Salmonella Typhimurium as estimated from co-mingled milk samples and to describe the resulting geographical patterns found in Texas dairy herds. Bulk tank milk samples were...

  19. The last GlacialeInterglacial transition in Patagonia, Argentina: the stable isotope record of bulk sedimentary organic matter from Laguna

    E-Print Network [OSTI]

    The last GlacialeInterglacial transition in Patagonia, Argentina: the stable isotope record of bulk cores recovered from the Patagonian lake Laguna Potrok Aike (Argentina) in the framework of the ICDP

  20. Modelling and comparison of trapped fields in (RE)BCO bulk superconductors for activation using pulsed field magnetization

    E-Print Network [OSTI]

    Ainslie, M. D.; Fujishiro, H.; Ujiie, T.; Zou, J.; Dennis, A. R.; Shi, Y.-H.; Cardwell, D. A.

    2014-04-08T23:59:59.000Z

    -1 Cn Heat capacity of liquid nitrogen at 77 K 1040 JK -1kg-1 kab Thermal conductivity of bulk along ab-plane 20 Wm -1K-1 kc Thermal conductivity of bulk along c-axis 4 Wm -1K-1 kn Thermal conductivity of liquid nitrogen 0.026 Wm -1K-1 E0... ) and Jnorm = ?(Jx 2 + Jy 2 + Jz 2). Table 1. Thermal model parameters PARAMETER DESCRIPTION VALUE Tc Transition temperature 92 K 𝜌𝑏 HTS bulk density 5.9 x 10 3 kgm-3 𝜌𝑛 Nitrogen density 808.4 kgm -3 Cb Heat capacity of bulk 1.32 x 10 2 Jkg-1K...

  1. Grain refinement using equal channel angular extrusion in bulk sections of copper 101 and aluminum alloys 3003 and 6061

    E-Print Network [OSTI]

    Ferrasse, Stephane

    1995-01-01T23:59:59.000Z

    GRAIN REFINEMENT USING EQUAL CHANNEL ANGULAR EXTRUSION IN BULK SECTIONS OF COPPER 101 AND ALUMINUM ALLOYS 3003 AND 6061 A Thesis by STEPHANE FERRASSE Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE May 1995 Major Subject: Mechanical Engineering GRAIN REFINEMENT USING EQUAL CHANNEL ANGULAR EXTRUSION IN BULK SECTIONS OF COPPER 101 AND ALUMINUM ALLOYS 3003 AND 6061 A Thesis by STEPHANE FERRASSE...

  2. Novel Mg-rich materials for hydrogen storage: bulk and nanoconfined Mg6Pd1-xTMx

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Novel Mg-rich materials for hydrogen storage: bulk and nanoconfined Mg6Pd1-xTMx (TM = Ni, Ag, Cu for hydrogen storage: bulk and nanoconfined Mg6Pd1-xTMx (TM = Ni, Ag, Cu) compounds and MgH2-TiH2 on Hydrogen Storage) and in Warsaw (E-MRS Fall Meeting). I would like to share this PhD thesis with all

  3. Nickel Alloy Primary Water Bulk Surface and SCC Corrosion Film Analytical Characterization and SCC Mechanistic Implications

    SciTech Connect (OSTI)

    Morton, D.; Lewis, N.; Hanson, M.; Rice, S.; Sanders, P.

    2007-04-18T23:59:59.000Z

    Alloy 600 corrosion coupon tests were performed: (1) to quantify the temperature dependency of general corrosion and (2) to characterize the composition and structure of bulk surface corrosion films for comparison with ongoing primary water SCC (PWSCC) crack tip corrosion film analyses. Results suggest that the thermal activation energy of Alloy 600 corrosion is consistent with the thermal activation energy of nickel alloy PWSCC. Analytical investigations of the structure and composition of Alloy 600 bulk surface corrosion oxides revealed a duplex (inner and outer) oxide layer structure. The outer layer is discontinuous and comprised of relatively large (1 to 3 {micro}m) nickel ferrite crystals and smaller ({approx}0.1 {micro}m) chromium containing nickel ferrite crystals. The inner layer consists of a relatively continuous chromite spinel (major phase) and chromia (Cr{sub 2}O{sub 3} minor phase) which formed through non-selective oxidation. Chromia and dealloyed Alloy 600 (highly Ni enriched metal) were only observed at 337 C (640 F) and only along the boundaries of deformation induced fine grains and subcells. Specimens having deformation free surfaces exhibited continuous uniform inner chromite spinel oxide layers. Specimens with machining induced surface deformation produced non-uniform inner layer oxides (chromite spinel, Cr{sub 2}O{sub 3} and unoxidized material). PWSCC crack tip oxides, in contrast, were fine grain (no duplex structure) and consisted of both chromium rich spinels and ''NiO'' structure oxides. Generally, nickel rich oxides were more abundant under more oxidized conditions (reduced coolant hydrogen) and spinel rich crack tip oxides were favored under more reducing conditions (increased coolant hydrogen). Bulk surface corrosion film thickness did not correlate with observed SCC growth rates. These results suggest that corrosion is not the rate controlling step of PWSCC but rather that PWSCC and corrosion have a common rate controlling sub process (e.g., cation diffusion, oxygen ingress).

  4. Bulk Vitrification Performance Enhancement: Refractory Lining Protection Against Molten Salt Penetration

    SciTech Connect (OSTI)

    Hrma, Pavel R.; Bagaasen, Larry M.; Schweiger, Michael J.; Evans, Michael B.; Smith, Benjamin T.; Arrigoni, Benjamin M.; Kim, Dong-Sang; Rodriguez, Carmen P.; Yokuda, Satoru T.; Matyas, Josef; Buchmiller, William C.; Gallegos, Autumn B.; Fluegel, Alexander

    2007-08-06T23:59:59.000Z

    Bulk vitrification (BV) is a process that heats a feed material that consists of glass-forming solids and dried low-activity waste (LAW) in a disposable refractory-lined metal box using electrical power supplied through carbon electrodes. The feed is heated to the point that the LAW decomposes and combines with the solids to generate a vitreous waste form. This study supports the BV design and operations by exploring various methods aimed at reducing the quantities of soluble Tc in the castable refractory block portion of the refractory lining, which limits the effectiveness of the final waste form.

  5. Radiation detector using a bulk high T[sub c] superconductor

    DOE Patents [OSTI]

    Artuso, J.F.; Franks, L.A.; Hull, K.L.; Symko, O.G.

    1993-12-07T23:59:59.000Z

    A radiation detector is provided, wherein a bulk high T[sub c] superconducting sample is placed in a magnetic field and maintained at a superconducting temperature. Photons of incident radiation will cause localized heating in superconducting loops of the sample destroying trapped flux and redistributing the fluxons, and reducing the critical current of the loops. Subsequent cooling of the sample in the magnetic field will cause trapped flux redistributed Abrikosov fluxons and trapped Josephson fluxons. The destruction and trapping of the fluxons causes changes in the magnetization of the sample inducing currents in opposite directions in a pickup coil which is coupled by an input coil to an rf SQUID. 4 figures.

  6. Bulk Thermodynamics of SU(N) Lattice Gauge Theories at Large-N

    E-Print Network [OSTI]

    Barak Bringoltz

    2005-11-04T23:59:59.000Z

    We present a study of bulk thermodynamical quantities in the deconfined phase of pure lattice SU(N) gauge theories. We find that the deficit in pressure and entropy with respect to their free-gas values, for N=4,8, is remarkably close to that of SU(3). Th is suggests that understanding the strongly interacting nature of the deconfined phase, which is crucial for RHIC physics, can be done at large N. There, different analytical approaches simplify or become soluble, and one can check their predictions and point to their important ingredients.

  7. Forest floor bulk density and depth at Savannah River - Draft Final Report.

    SciTech Connect (OSTI)

    Maier, Brian; Ottmar, Roger; Wright, Clint

    2004-12-28T23:59:59.000Z

    Knowing the amount of biomass across a landscape is becoming increasingly important to fire managers as new fuel and fire management decision support systems come on line. Fire managers rarely have the time or funding available to sample fuels operationally and often depend upon mean values for critical variables whose variation is often associated with simple stand characteristics such as age, forest type, time since last burn, stocking, or site, and other easily measured variables. This report outlines a study to collect and analyze litter and duff bulk density samples for developing a simple predictive tool to estimate forest floor fuel loading based on simple stand characteristics.

  8. Jump chaotic behaviour of ultra low loss bulk acoustic wave cavities

    SciTech Connect (OSTI)

    Goryachev, Maxim, E-mail: maxim.goryachev@uwa.edu.au; Farr, Warrick G.; Tobar, Michael E. [ARC Centre of Excellence for Engineered Quantum Systems, University of Western Australia, 35 Stirling Highway, Crawley WA 6009 (Australia); Galliou, Serge [Department of Time and Frequency, FEMTO-ST Institute, ENSMM, 26 Chemin de l'Épitaphe 25000 Besançon (France)

    2014-08-11T23:59:59.000Z

    We demonstrate a previously unobserved nonlinear phenomenon in an ultra-low loss quartz bulk acoustic wave cavity (Q>3>10{sup 9}), which only occurs below 20 mK in temperature and under relatively weak pumping. The phenomenon reveals the emergence of several stable equilibria (at least two foci and two nodes) and jumps between these quasi states at random times. The degree of this randomness as well as separations between levels can be controlled by the frequency of the incident carrier signal. It is demonstrated that the nature of the effect lies beyond the standard Duffing model.

  9. Ultrafast magneto-photocurrents in GaAs: Separation of surface and bulk contributions

    E-Print Network [OSTI]

    Schmidt, Christian B; Tarasenko, Sergey A; Bieler, Mark

    2015-01-01T23:59:59.000Z

    We induce ultrafast magneto-photocurrents in a GaAs crystal employing interband excitation with femtosecond laser pulses at room temperature and non-invasively separate surface and bulk contributions to the overall current response. The separation between the different symmetry contributions is achieved by measuring the simultaneously emitted terahertz radiation for different sample orientations. Excitation intensity and photon energy dependences of the magneto-photocurrents for linearly and circularly polarized excitations reveal an involvement of different microscopic origins, one of which we believe is the inverse Spin-Hall effect. Our experiments are important for a better understanding of the complex momentum-space carrier dynamics in magnetic fields.

  10. Heat treatment of bulk gallium arsenide using a phosphosilicate glass cap

    SciTech Connect (OSTI)

    Mathur, G.; Wheaton, M.L.; Borrego, J.M.; Ghandhi, S.K.

    1985-05-15T23:59:59.000Z

    n-type bulk GaAs crystals, capped with chemically vapor-deposited phosphosilicate glass, were heat treated at temperatures in the range of 600 to 950 /sup 0/C. Measurements on Schottky diodes and solar cells fabricated on the heat-treated material, after removal of a damaged surface layer, show an increase in free-carrier concentration, in minority-carrier-diffusion length, and in solar-cell short-circuit current. The observed changes are attributed to a removal of lifetime-reducing acceptorlike impurities, defects, or their complexes.

  11. A new damage testing system for detailed evaluation of damage behavior of bulk KDP and DKDP

    SciTech Connect (OSTI)

    DeMange, P; Negres, R A; Carr, C W; Radousky, H B; Demos, S G

    2004-11-17T23:59:59.000Z

    We describe a new damage testing approach and instrumentation that provides quantitative measurements of bulk damage performance versus fluence for several frequencies. A major advantage of this method is that it can simultaneously provide direct information on pinpoint density and size, and beam obscuration. This allows for more accurate evaluation of material performance under operational conditions. Protocols for laser conditioning to improve damage performance can also be easily and rapidly evaluated.This damage testing approach has enabled us to perform complex experiments toward probing the fundamental mechanisms of damage initiation and conditioning.

  12. Preparation of extrusions of bulk mixed oxide compounds with high macroporosity and mechanical strength

    DOE Patents [OSTI]

    Flytzani-Stephanopoulos, Maria (Winchester, MA); Jothimurugesan, Kandaswami (Baton Rouge, LA)

    1990-01-01T23:59:59.000Z

    A simple and effective method for producing bulk single and mixed oxide absorbents and catalysts is disclosed. The method yields bulk single oxide and mixed oxide absorbent and catalyst materials which combine a high macroporosity with relatively high surface area and good mechanical strength. The materials are prepared in a pellet form using as starting compounds, calcined powders of the desired composition and physical properties these powders are crushed to broad particle size distribution, and, optionally may be combined with an inorganic clay binder. The necessary amount of water is added to form a paste which is extruded, dried and heat treated to yield and desired extrudate strength. The physical properties of the extruded materials (density, macroporosity and surface area) are substantially the same as the constituent powder is the temperature of the heat treatment of the extrudates is approximately the same as the calcination temperature of the powder. If the former is substantially higher than the latter, the surface area decreases, but the macroporosity of the extrusions remains essentially constant.

  13. ANALYSES AND COMPARISON OF BULK AND COIL SURFACE SAMPLES FROM THE DWPF SLURRY MIX EVAPORATOR

    SciTech Connect (OSTI)

    Hay, M.; Nash, C.; Stone, M.

    2012-02-17T23:59:59.000Z

    Sludge samples from the DWPF Slurry Mix Evaporator (SME) heating coil frame and coil surface were characterized to identify differences that might help identify heat transfer fouling materials. The SME steam coils have seen increased fouling leading to lower boil-up rates. Samples of the sludge were taken from the coil frame somewhat distant from the coil (bulk tank material) and from the coil surface (coil surface sample). The results of the analysis indicate the composition of the two SME samples are very similar with the exception that the coil surface sample shows {approx}5-10X higher mercury concentration than the bulk tank sample. Elemental analyses and x-ray diffraction results did not indicate notable differences between the two samples. The ICP-MS and Cs-137 data indicate no significant differences in the radionuclide composition of the two SME samples. Semi-volatile organic analysis revealed numerous organic molecules, these likely result from antifoaming additives. The compositions of the two SME samples also match well with the analyzed composition of the SME batch with the exception of significantly higher silicon, lithium, and boron content in the batch sample indicating the coil samples are deficient in frit relative to the SME batch composition.

  14. Measuring the bulk Lorentz factors of gamma-ray bursts with Fermi

    E-Print Network [OSTI]

    Tang, Qing-Wen; Wang, Xiang-Yu; Tam, Pak-Hin Thomas

    2014-01-01T23:59:59.000Z

    Gamma-ray bursts (GRBs) are powered by ultra-relativistic jets. Usually a minimum value of the Lorentz factor of the relativistic bulk motion is obtained based on the argument that the observed high energy photons ($\\gg {\\rm MeV}$) can escape without suffering from absorption due to pair production. The exact value, rather than a lower limit, of the Lorentz factor can be obtained if the spectral cutoff due to such absorption is detected. With the good spectral coverage of the Large Area Telescope (LAT) on {\\em Fermi}, measurements of such cutoff become possible, and two cases (GRB 090926A and GRB 100724B) have been reported to have high-energy cutoffs or breaks. We systematically search for such high energy spectral cutoffs/breaks from LAT and GBM observations of the prompt emission of GRBs detected since August 2011. Seven more GRBs are found to have cutoff-like spectral feature at energies of $\\sim20-300$ MeV. Assuming that these cutoffs are caused by pair-production absorption within the source, the bulk L...

  15. Bulk diffusion induced structural modifications of carbon-transition metal nanocomposite films

    SciTech Connect (OSTI)

    Berndt, M.; Abrasonis, G.; Kovacs, Gy. J.; Krause, M.; Munnik, F.; Heller, R.; Kolitsch, A.; Moeller, W.

    2011-03-15T23:59:59.000Z

    The influence of transition metal (TM = V,Co,Cu) type on the bulk diffusion induced structural changes in carbon:TM nanocomposite films is investigated. The TMs have been incorporated into the carbon matrix via ion beam co-sputtering, and subsequently the films have been vacuum annealed in the temperature range of 300 - 700 deg. C. The structure of both the dispersed metal rich and the carbon matrix phases has been determined by a combination of elastic recoil detection analysis, x-ray diffraction, transmission electron microscopy, and Raman spectroscopy. The as-grown films consist of carbidic (V and Co) and metallic (Cu) nanoparticles dispersed in the carbon matrix. Thermal annealing induces surface segregation of Co and Cu starting at {>=} 500 deg. C, preceded by the carbide-metal transformation of Co-carbide nanoparticles at {approx} 300 deg. C. No considerable morphological changes occur in C:V films. In contrast to the surface diffusion dominated regime where all the metals enhance the six-fold ring clustering of C, in the bulk diffusion controlled regime only Co acts as a catalyst for the carbon graphitization. These results are consistent with the metal-induced crystallization mechanism in the C:Co films. The results are discussed on the basis of the metal-carbide phase stability, carbon solubility in metals or their carbides, and interface species.

  16. Local and bulk 13C hyperpolarization in NV-centered diamonds at variable fields and orientations

    E-Print Network [OSTI]

    Gonzalo A. Alvarez; Christian O. Bretschneider; Ran Fischer; Paz London; Hisao Kanda; Shinobu Onoda; Junichi Isoya; David Gershoni; Lucio Frydman

    2014-12-30T23:59:59.000Z

    Polarizing nuclear spins is of fundamental importance in biology, chemistry and physics. Methods for hyperpolarizing 13C nuclei from free electrons in bulk, usually demand operation at cryogenic temperatures. Room-temperature approaches targeting diamonds with nitrogen-vacancy (NV) centers could alleviate this need, but hitherto proposed strategies lack generality as they demand stringent conditions on the strength and/or alignment of the magnetic field. We report here an approach for achieving efficient electron->13C spin alignment transfers, compatible with a broad range of magnetic field strengths and field orientations with respect to the diamond crystal. This versatility results from combining coherent microwave- and incoherent laser-induced transitions between selected energy states of the coupled electron-nuclear spin manifold. 13C-detected Nuclear Magnetic Resonance (NMR) experiments demonstrate that this hyperpolarization can be transferred via first-shell or via distant 13Cs, throughout the nuclear bulk ensemble. This method opens new perspectives for applications of diamond NV centers in NMR, and in quantum information processing.

  17. Fabrication of ZnO photonic crystals by nanosphere lithography using inductively coupled-plasma reactive ion etching with CH{sub 4}/H{sub 2}/Ar plasma on the ZnO/GaN heterojunction light emitting diodes

    SciTech Connect (OSTI)

    Chen, Shr-Jia; Chang, Chun-Ming; Kao, Jiann-Shiun; Chen, Fu-Rong; Tsai, Chuen-Horng [Engineering and System Science, National Tsing Hua University, Hsinchu, 30013 Taiwan (China); Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu, 300 Taiwan (China); Engineering and System Science, National Tsing Hua University, Hsinchu, 30013 Taiwan (China)

    2010-07-15T23:59:59.000Z

    This article reports fabrication of n-ZnO photonic crystal/p-GaN light emitting diode (LED) by nanosphere lithography to further booster the light efficiency. In this article, the fabrication of ZnO photonic crystals is carried out by nanosphere lithography using inductively coupled plasma reactive ion etching with CH{sub 4}/H{sub 2}/Ar plasma on the n-ZnO/p-GaN heterojunction LEDs. The CH{sub 4}/H{sub 2}/Ar mixed gas gives high etching rate of n-ZnO film, which yields a better surface morphology and results less plasma-induced damages of the n-ZnO film. Optimal ZnO lattice parameters of 200 nm and air fill factor from 0.35 to 0.65 were obtained from fitting the spectrum of n-ZnO/p-GaN LED using a MATLAB code. In this article, we will show our recent result that a ZnO photonic crystal cylinder has been fabricated using polystyrene nanosphere mask with lattice parameter of 200 nm and radius of hole around 70 nm. Surface morphology of ZnO photonic crystal was examined by scanning electron microscope.

  18. High Efficiency m-plane LEDs on Low Defect Density Bulk GaN Substrates

    SciTech Connect (OSTI)

    David, Aurelien

    2012-10-15T23:59:59.000Z

    Solid-state lighting is a key technology for reduction of energy consumption in the US and worldwide. In principle, by replacing standard incandescent bulbs and other light sources with sources based on light-emitting diodes (LEDs), ultimate energy efficiency can be achieved. The efficiency of LEDs has improved tremendously over the past two decades, however further progress is required for solid- state lighting to reach its full potential. The ability of an LED at converting electricity to light is quantified by its internal quantum efficiency (IQE). The material of choice for visible LEDs is Gallium Nitride (GaN), which is at the basis of blue-emitting LEDs. A key factor limiting the performance of GaN LEDs is the so-called efficiency droop, whereby the IQE of the LED decreases significantly at high current density. Despite decades of research, efficiency droop remains a major issue. Since high-current operation is necessary for practical lighting applications, reducing droop is a major challenge for the scientific community and the LED industry. Our approach to solving the droop issue is the use of newly available low-defect-density bulk GaN non-polar substrates. In contrast to the standard foreign substrates (sapphire, silicon carbide, silicon) used in the industry, we have employed native bulk GaN substrates with very low defect density, thus ensuring exquisite material quality and high IQE. Whereas all commercial LEDs are grown along the c-plane crystal direction of GaN, we have used m-plane non-polar substrates; these drastically modify the physical properties of the LED and enable a reduction of droop. With this approach, we have demonstrated very high IQE performance and low droop. Our results focused on violet and blue LEDs. For these, we have demonstrated very high peak IQEs and current droops of 6% and 10% respectively (up to a high current density of 200A.cm-2). All these results were obtained under electrical operation. These high IQE and low droop values are in line with the program’s milestones. They demonstrate that bulk non-polar GaN substrates represent a disruptive technology for LED performance. Application of this technology to real-world products is feasible, provided that the cost of GaN substrates is compatible with the market’s requirement.

  19. Bulk-SQUID effect in a discrete superconductor as a consequence of generation frequency locking in constituent josephson junctions

    SciTech Connect (OSTI)

    Ginzburg, S. L.; Nakin, A. V.; Savitskaya, N. E., E-mail: savitska@inbox.ru [Russian Academy of Sciences, Konstantinov Institute of Nuclear Physics (Russian Federation)

    2012-02-15T23:59:59.000Z

    The theory of the bulk-SQUID effect in discrete superconductors is constructed for the first time. It is shown that the bulk-SQUID effect emerges in the system of 2D intrinsically stochastic multijunction SQUID (i.e., with random values of critical currents of the junctions, injection currents, and the coupling coefficients between the junction) due to generation frequency locking in all junctions. It is demonstrated that the bulk-SQUID effect occurs in a wide range of random parameters of the system. This domain of variation of the system parameters can be divided into three subdomains. The first one is the subdomain of coherent dynamics of phases at the junctions, the second is the subdomain of incoherent dynamics, in which the phases of the junctions are not locked, but the bulk-SQUID effect persists, and the third is the subdomain of transient dynamics, in which coherent dynamics and the bulk-SQUID effect are observed in parts. A simple mathematical model of noninteracting junctions, which correctly describes basic features of the dynamics of the initial system and makes it possible to calculate some of its statistical characteristics, is proposed and analyzed.

  20. Further development and testing of a second-order bulk boundary layer model. Master's thesis

    SciTech Connect (OSTI)

    Krasner, R.D.

    1993-05-03T23:59:59.000Z

    A one-layer bulk boundary layer model is developed. The model predicts the mixed layer values of the potential temperature, mixing ratio, and u- and v-momentum. The model also predicts the depth of the boundary layer and the vertically integrated turbulence kinetic energy (TKE). The TKE is determined using a second-order closure that relates the rate of dissipation to the TKE. The fractional area covered by rising motion sigma and the entrainment rate (E) are diagnostically determined. The model is used to study the clear convective boundary layer (CBL) using data from the Wangara, Australia boundary layer experiment. The Wangara data is also used as an observation base to validate model results. A further study is accomplished by simulating the planetary boundary layer (PBL) over an ocean surface. This study is designed to find the steady-state solutions of the prognostic variable.

  1. Excitonic enhancement of nonradiative energy transfer to bulk silicon with the hybridization of cascaded quantum dots

    SciTech Connect (OSTI)

    Yeltik, Aydan; Guzelturk, Burak; Akhavan, Shahab [Department of Physics and Department of Electrical and Electronics Engineering, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey)] [Department of Physics and Department of Electrical and Electronics Engineering, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey); Ludwig Hernandez-Martinez, Pedro; Volkan Demir, Hilmi, E-mail: volkan@stanfordalumni.org [Department of Physics and Department of Electrical and Electronics Engineering, UNAM—Institute of Materials Science and Nanotechnology, Bilkent University, Ankara 06800 (Turkey); Luminous Center of Excellence for Semiconductor Lighting and Displays, School of Electrical and Electronic Engineering and School of Physical and Mathematical Sciences, Nanyang Technological University, Nanyang Avenue, Singapore 639798 (Singapore)

    2013-12-23T23:59:59.000Z

    We report enhanced sensitization of silicon through nonradiative energy transfer (NRET) of the excitons in an energy-gradient structure composed of a cascaded bilayer of green- and red-emitting CdTe quantum dots (QDs) on bulk silicon. Here NRET dynamics were systematically investigated comparatively for the cascaded energy-gradient and mono-dispersed QD structures at room temperature. We show experimentally that NRET from the QD layer into silicon is enhanced by 40% in the case of an energy-gradient cascaded structure as compared to the mono-dispersed structures, which is in agreement with the theoretical analysis based on the excited state population-depopulation dynamics of the QDs.

  2. Interplay between bulk medium evolution and (D)GLV energy loss

    E-Print Network [OSTI]

    Denes Molnar; Deke Sun

    2014-05-19T23:59:59.000Z

    We study the consistency between high-pT nuclear suppression (R_AA) and elliptic flow (v2) using Gyulassy-Levai-Vitev (GLV) energy loss or a simpler power-law dE/dL formula, for a variety of bulk evolution models. The results generally confirm our earlier work [arXiv:1305.1046] that found suppressed elliptic flow for transversely expanding media. One exception is the set of hydrodynamic solutions used recently [arXiv:1305.6458] by Betz and Gyulassy, which give significantly higher v2 but unfortunately assume unrealistic bag-model equation of state. On the other hand, we show that covariant treatment of energy loss introduces an interplay between jet direction and hydrodynamic flow of the medium, which largely counteracts elliptic flow suppression caused by transverse expansion.

  3. Hydrogen in tin dioxide films and bulk ceramics: An attempt to identify the most hidden impurity

    SciTech Connect (OSTI)

    Watanabe, Ken, E-mail: WATANABE.Ken@nims.go.jp [National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); International Center for Young Scientists (ICYS-MANA), NIMS, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Hashiguchi, Minako; Sakaguchi, Isao; Bryant, Alex, E-mail: awbryant@gatech.edu; Adachi, Yutaka; Zhen, Yuhua, E-mail: zhenyh@upc.edu.cn; Ohgaki, Takeshi; Ohsawa, Takeo; Haneda, Hajime [National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Ohashi, Naoki, E-mail: OHASHI.Naoki@nims.go.jp [National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Materials Research Center for Element Strategy (MCES), Mailbox S2-13, Tokyo Institute of Technology, 13-4259 Nagatsuta, Midori-ku, Yokohama 226-0026 (Japan)

    2014-01-27T23:59:59.000Z

    Hydrogen impurities in SnO{sub 2} films and bulk ceramics were investigated in terms of mass transport and electron transport. The hydrogen concentration (n[H]) in these samples was found to be 10{sup 19}?cm{sup ?3} or higher. Further increase in n[H] could be achieved by annealing the samples in a humid atmosphere. The isotope tracer ({sup 1}H/{sup 2}H exchange) study revealed that a part of the hydrogen in these samples showed rapid migration even at 300?°C. However, electrical measurements revealed that the electron concentration in the samples was much less than n[H]. These results could be explained by assuming the presence of defect-hydrogen complexes.

  4. Combustion of Bulk 84% Fe/16% KCIO{sub 4} heat powder

    SciTech Connect (OSTI)

    Nissen, M.; Guidotti, R.A.; Berry, B.

    1996-05-01T23:59:59.000Z

    Fe/KClO{sub 4} pyrotechnic mixtures are used in thermal batteries to provide the heat necessary to bring the battery stack to operating temperatures of 550 to 600 C. This heat source is normally used as discs pressed from bulk powder. To evaluate the consequences associated with unexpected ignition of large amounts of heat powder, combustion of 84% Fe/16% KClO{sub 4} heat powders was conducted for various scenarios under controlled conditions and the response documented. Increasing amounts of heat powder--up to 8 lbs--were ignited in both unconfined and confined (sealed) containers in a remote area. The containers were thermocoupled and the resulting burning filmed with a standard video camera, high-speed (1,000 frames/s) film and video cameras, and an infrared video camera. A 20- minute video of the burning under the various conditions is presented.

  5. Changing Trends in the Bulk Chemicals and Pulp and Paper Industries (released in AEO2005)

    Reports and Publications (EIA)

    2005-01-01T23:59:59.000Z

    Compared with the experience of the 1990s, rising energy prices in recent years have led to questions about expectations of growth in industrial output, particularly in energy-intensive industries. Given the higher price trends, a review of expected growth trends in selected industries was undertaken as part of the production of Annual Energy Outlook 2005 (AEO). In addition, projections for the industrial value of shipments, which were based on the Standard Industrial Classification (SIC) system in AEO2004, are based on the North American Industry Classification System (NAICS) in AEO2005. The change in industrial classification leads to lower historical growth rates for many industrial sectors. The impacts of these two changes are highlighted in this section for two of the largest energy-consuming industries in the U.S. industrial sector-bulk chemicals and pulp and paper.

  6. High etching rates of bulk Nb in Ar/Cl{sub 2} microwave discharge

    SciTech Connect (OSTI)

    Raskovic, M.; Popovic, S.; Upadhyay, J.; Vuskovic, L.; Phillips, L.; Valente-Feliciano, A.-M. [Department of Physics, Old Dominion University, Norfolk, Virginia 23529 (United States); Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606 (United States)

    2009-03-15T23:59:59.000Z

    Plasma-based Nb surface treatment provides an excellent opportunity to eliminate surface imperfections and increase the cavity quality factor in important applications such as particle accelerators and cavity quantum electrodynamics, as well as Josephson junctions. In this study, plasma etching of bulk Nb is performed on the surface of disk-shaped samples with the goal of eliminating nonsuperconductive pollutants in the penetration depth region and the mechanically damaged surface layer. The authors have demonstrated that in the microwave glow discharge, an etching rate of 1.5 {mu}m/min can be achieved using Cl{sub 2} as a reactive gas. The influence of plasma parameters such as input power, pressure, and concentration of the reactive gas on the etching rate is determined. Simultaneously, plasma emission spectroscopy was used to estimate the densities of Cl, Cl{sup +}, and Cl{sub 2} under various plasma conditions.

  7. Rapid Relaxation and Embrittlement of Zr-based Bulk Metallic Glasses by Electropulsing

    SciTech Connect (OSTI)

    Yiu, P [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan; Chen, Y. C. [National Taiwan University of Science & Technology; Chu, J. P. [National Taiwan Ocean University; Chang, S Y [National Chung Hsing University; Bei, Hongbin [ORNL; Jang, J. S.C. [National Central University, Jhongli 32001, Taiwan; Hsueh, C. H. [Department of Materials Science and Engineering, National Taiwan University, Taipei 106, Taiwan

    2013-01-01T23:59:59.000Z

    Mechanical relaxation and embrittlement of Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glasses were achieved rapidly by the direct current electropulsing treatment. The temperature profile was recorded by an infrared camera and it was found to be non-uniform in the treated specimen. Specifically, temperatures below the glass transition temperature, near and above the crystallization temperature could be ach- ieved, respectively, at different locations in the same treated specimen. Two sets of nanoindentation were conducted. While the first set investigated the mechanical properties of three individually elec- tropulsed specimens with different conditions, the second set indented a single treated specimen along its temperature gradient. Both sets of indentation revealed that by Joule heating to different tempera- tures, relaxation, embrittlement, and crystallization were significantly accelerated by electrical pulses. Results suggest that electropulsing provides an opportunity to simultaneously achieve plastic forming and mechanical property control of metallic glasses.

  8. Method of casting articles of a bulk-solidifying amorphous alloy

    DOE Patents [OSTI]

    Lin, X.; Johnson, W.L.; Peker, A.

    1998-08-25T23:59:59.000Z

    A casting charge of a bulk-solidifying amorphous alloy is cast into a mold from a temperature greater than its crystallized melting temperature, and permitted to solidify to form an article. The oxygen content of the casting charge is limited to an operable level, as excessively high oxygen contents produce premature crystallization during the casting operation. During melting, the casting charge is preferably heated to a temperature above a threshold temperature to eliminate heterogeneous crystallization nucleation sites within the casting charge. The casting charge may be cast from above the threshold temperature, or it may be cooled to the casting temperature of more than the crystallized melting point but not more than the threshold temperature, optionally held at this temperature for a period of time, and thereafter cast. 8 figs.

  9. Method of casting articles of a bulk-solidifying amorphous alloy

    DOE Patents [OSTI]

    Lin, Xianghong (Laguna Niguel, CA); Johnson, William L. (Pasadena, CA); Peker, Atakan (Aliso Viejo, CA)

    1998-01-01T23:59:59.000Z

    A casting charge of a bulk-solidifying amorphous alloy is cast into a mold from a temperature greater than its crystallized melting temperature, and permitted to solidify to form an article. The oxygen content of the casting charge is limited to an operable level, as excessively high oxygen contents produce premature crystallization during the casting operation. During melting, the casting charge is preferably heated to a temperature above a threshold temperature to eliminate heterogeneous crystallization nucleation sites within the casting charge. The casting charge may be cast from above the threshold temperature, or it may be cooled to the casting temperature of more than the crystallized melting point but not more than the threshold temperature, optionally held at this temperature for a period of time, and thereafter cast.

  10. Anomalous absorption of bulk shear sagittal acoustic waves in a layered structure with viscous fluid

    E-Print Network [OSTI]

    Dmitri K. Gramotnev; Melissa L. Mather; Timo A. Nieminen

    2005-09-05T23:59:59.000Z

    It is demonstrated theoretically that the absorptivity of bulk shear sagittal waves by an ultra-thin layer of viscous fluid between two different elastic media has a strong maximum (in some cases as good as 100%) at an optimal layer thickness. This thickness is usually much smaller than the penetration depths and lengths of transverse and longitudinal waves in the fluid. The angular dependencies of the absorptivity are demonstrated to have significant and unusual structure near critical angles of incidence. The effect of non-Newtonian properties and non-uniformities of the fluid layer on the absorptivity is also investigated. In particular, it is shown that the absorption in a thin layer of viscous fluid is much more sensitive to non-zero relaxation time(s) in the fluid layer than the absorption at an isolated solid-fluid interface.

  11. Synthesis of bulk metallic glass foam by powder extrusion with a fugitive second phase

    SciTech Connect (OSTI)

    Lee, Min Ha; Sordelet, Daniel J. [Materials and Engineering Physics Program, Ames Laboratory, Iowa State University, Ames, Iowa 50011 (United States)

    2006-07-10T23:59:59.000Z

    Bulk metallic glass foams with 12 mm in diameter and 30 mm in length having a density of 4.62 g/cm{sup 3} (approximately 58.3% of theoretical) were fabricated by extruding a powder mixture comprised of 60 vol % Ni{sub 59}Zr{sub 20}Ti{sub 16}Si{sub 2}Sn{sub 3} metallic glass blended with 40 vol % brass followed by dissolution of the fugitive brass in an aqueous HNO{sub 3} solution. The final structure consists of continuously connected, high aspect ratio metallic glass struts surrounded by {approx}40 vol % of homogeneously distributed ellipsoid-shaped pores having nominal diameters between 10 and 50 {mu}m.

  12. Thermodynamic Relationships for Bulk Crystalline and Liquid Phases in the Phase-Field Crystal Model

    E-Print Network [OSTI]

    Victor W. L. Chan; Nirand Pisutha-Arnond; Katsuyo Thornton

    2015-02-06T23:59:59.000Z

    We present thermodynamic relationships between the free energy of the phase-field crystal (PFC) model and thermodynamic state variables for bulk phases under hydrostatic pressure. This relationship is derived based on the thermodynamic formalism for crystalline solids of Larch\\'e and Cahn [Larch\\'e and Cahn, Acta Metallurgica, Vol. 21, 1051 (1973)]. We apply the relationship to examine the thermodynamic processes associated with varying the input parameters of the PFC model: temperature, lattice spacing, and the average value of the PFC order parameter, $\\bar{n}$. The equilibrium conditions between bulk crystalline solid and liquid phases are imposed on the thermodynamic relationships for the PFC model to obtain a procedure for determining solid-liquid phase coexistence. The resulting procedure is found to be in agreement with the method commonly used in the PFC community, justifying the use of the common-tangent construction to determine solid-liquid phase coexistence in the PFC model. Finally, we apply the procedure to an eighth-order-fit (EOF) PFC model that has been parameterized to body-centered-cubic ($bcc$) Fe [Jaatinen et al., Physical Review E 80, 031602 (2009)] to demonstrate the procedure as well as to develop physical intuition about the PFC input parameters. We demonstrate that the EOF-PFC model parameterization does not predict stable $bcc$ structures with positive vacancy densities. This result suggests an alternative parameterization of the PFC model, which requires the primary peak position of the two-body direct correlation function to shift as a function of $\\bar{n}$.

  13. Annealing behavior of the hydrogen-vacancy complex in bulk indium phosphide crystals

    SciTech Connect (OSTI)

    Ye, Q.; Wolk, J.A.; Bourret-Courchesne, E.D. [Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.; Bliss, D.F. [Air Force Rome Lab., Hanscom AFB, MA (United States)

    1998-12-31T23:59:59.000Z

    In order to explain the effects of hydrogen on the electrical properties of bulk indium phosphide crystals, they have performed a series of high temperature annealing studies with both undoped and iron-doped indium phosphide crystals. The samples were annealed at 900 C for 6, 36, and 72 hours, respectively, under a phosphorus overpressure of five atmospheres. Samples were characterized at 10 K by Fourier transform infrared absorption spectroscopy which allowed us to measure the concentrations of both the Fe{sup 2+} and V{sub In}-H{sub 4} defects simultaneously. Undoped samples were further characterized by the Hall effect measurements. The authors find in the iron-doped samples that the [Fe{sup 2+}]/[Fe{sup 3+}] ratio decreases gradually with increasing annealing time, indicating a reduction in the number of donors in the samples. In the undoped samples, annealing leads to a reduction of the free electron concentration accompanied by an increase in the 77 K mobility. The increase of the sample`s mobility eliminates the possibility that the reduction of the free electron concentration is due to an increase in the concentration of the compensating acceptors. The explanation for the observed behavior in all samples is that hydrogen acts as a donor and it diffuses out of the crystal during the annealing process. Based on the experimental data, they propose a calibration equation of [V{sub In}-H{sub 4}] = 4.2 {times} 10{sup 16} cm{sup {minus}1} {times} Absorbance (cm{sup {minus}1}) which is used to correlate the hydrogen-vacancy complex concentrations with the changes of the V{sub In}-H{sub 4} absorption peak in both the iron-doped and the undoped samples. Their results confirm the donor nature of the hydrogen-vacancy complex and provide strong evidence regarding the reduction mechanism of free carrier concentrations in bulk indium phosphide crystals during high temperature annealing under a phosphorus atmosphere.

  14. Surface and bulk studies of leached and unleached fly ash using XPS, SEM, EDS and FTIR techniques

    SciTech Connect (OSTI)

    Yousuf, M.; Mollah, A.; Hess, T.R.; Cocke, D.L. [Lamar Univ., Beaumont, TX (United States). Gill Chair of Chemistry

    1994-04-01T23:59:59.000Z

    The effective chemical utilization of fly ash in environmental applications requires a detailed knowledge of the surface and bulk changes induced by leaching in acid solutions. The surface and bulk characteristics of fly ash from the combustion of Texas lignite have been examined by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and Fourier transform infrared spectroscopy (FTIR). The effects of leaching with acid solutions commonly used in environmental studies have been documented using these techniques. The results of these studies reveal that the fly ash particles are relatively resistance to either chemical or physical changes due to attack by acidic leaching solutions.

  15. A Bulk Tungsten Tile for JET: Derivation of Power-Handling Performance and Validation of the Thermal Model, in the MARION Facility

    E-Print Network [OSTI]

    A Bulk Tungsten Tile for JET: Derivation of Power-Handling Performance and Validation of the Thermal Model, in the MARION Facility

  16. Evaluation of X-ray Diffraction of Bit Cuttings as a Proxy for Core Data in Determining Bulk Mineralogy and Clay Species, Bakken Formation, Williston Basin.

    E-Print Network [OSTI]

    Barnes, Stuart Lee

    2011-01-01T23:59:59.000Z

    ??The principal question addressed in this study concerns the applicability of x-ray diffractometry to determine bulk rock mineralogy and clay species in the absence of… (more)

  17. Bulk ion acceleration and particle heating during magnetic reconnection in a laboratory plasma

    SciTech Connect (OSTI)

    Yoo, Jongsoo; Yamada, Masaaki; Ji, Hantao; Jara-Almonte, Jonathan; Myers, Clayton E. [Center for Magnetic Self-Organization, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)] [Center for Magnetic Self-Organization, Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543 (United States)

    2014-05-15T23:59:59.000Z

    Bulk ion acceleration and particle heating during magnetic reconnection are studied in the collisionless plasma of the Magnetic Reconnection Experiment (MRX). The plasma is in the two-fluid regime, where the motion of the ions is decoupled from that of the electrons within the ion diffusion region. The reconnection process studied here is quasi-symmetric since plasma parameters such as the magnitude of the reconnecting magnetic field, the plasma density, and temperature are compatible on each side of the current sheet. Our experimental data show that the in-plane (Hall) electric field plays a key role in ion heating and acceleration. The electrostatic potential that produces the in-plane electric field is established by electrons that are accelerated near the electron diffusion region. The in-plane profile of this electrostatic potential shows a “well” structure along the direction normal to the reconnection current sheet. This well becomes deeper and wider downstream as its boundary expands along the separatrices where the in-plane electric field is strongest. Since the in-plane electric field is 3–4 times larger than the out-of-plane reconnection electric field, it is the primary source of energy for the unmagnetized ions. With regard to ion acceleration, the Hall electric field causes ions near separatrices to be ballistically accelerated toward the outflow direction. Ion heating occurs as the accelerated ions travel into the high pressure downstream region. This downstream ion heating cannot be explained by classical, unmagnetized transport theory; instead, we conclude that ions are heated by re-magnetization of ions in the reconnection exhaust and collisions. Two-dimensional (2-D) simulations with the global geometry similar to MRX demonstrate downstream ion thermalization by the above mechanisms. Electrons are also significantly heated during reconnection. The electron temperature sharply increases across the separatrices and peaks just outside of the electron diffusion region. Unlike ions, electrons acquire energy mostly from the reconnection electric field, and the energy gain is localized near the X-point. However, the increase in the electron bulk flow energy remains negligible. These observations support the assertion that efficient electron heating mechanisms exist around the electron diffusion region and that the heat generated there is quickly transported along the magnetic field due to the high parallel thermal conductivity of electrons. Classical Ohmic dissipation based on the perpendicular Spitzer resistivity is too small to balance the measured heat flux, indicating the presence of anomalous electron heating.

  18. Terahertz radiation and second-harmonic generation from InAs: Bulk versus surface electric-field-induced contributions

    E-Print Network [OSTI]

    Reid, Matthew

    Terahertz radiation and second-harmonic generation from InAs: Bulk versus surface electric-harmonic generation and terahertz radiation emission indicates that the observed dominant surface electric-field-induced contributions Matthew Reid, Igor V. Cravetchi, and Robert Fedosejevs Department of Electrical and Computer

  19. PHYSICAL REVIEW B 89, 035414 (2014) Excitonic recombinations in h-BN: From bulk to exfoliated layers

    E-Print Network [OSTI]

    Plaçais, Bernard

    2014-01-01T23:59:59.000Z

    PHYSICAL REVIEW B 89, 035414 (2014) Excitonic recombinations in h-BN: From bulk to exfoliated of nanosheets mechanically exfoliated from them. First, the link between the presence of structural defects, the h-BN thickness was reduced down to six atomic layers, using mechanical exfoliation, as evidenced

  20. Assessment of peat quality by molecular and bulk geochemical analysis: Application to the Holocene record of the Chautagne

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Assessment of peat quality by molecular and bulk geochemical analysis: Application to the Holocene in general from a limited variety of local plants, peat is however sensitive to physicochemical changes the information on peat quality provided by various families of biochemical components (lipids, lignin, sugars

  1. Modeling clouds observed at SHEBA using a bulk microphysics parameterization implemented into a single-column model

    E-Print Network [OSTI]

    Shupe, Matthew

    cloud fraction, that is, underpredicting the frequency of liquid- or mixed-phase clouds. The mean ice associated with leads, ``clear-sky'' ice crystal precipitation, and persis- tent mixed-phase clouds. BiasesModeling clouds observed at SHEBA using a bulk microphysics parameterization implemented

  2. Bulk Power Systems Dynamics and Control -IV Restructuring, Santorini, Greece, August 1998 IS MODAL RESONANCE A PRECURSOR TO

    E-Print Network [OSTI]

    Bulk Power Systems Dynamics and Control - IV Restructuring, Santorini, Greece, August 1998 IS MODAL RESONANCE A PRECURSOR TO POWER SYSTEM OSCILLATIONS? Ian Dobson Jianfeng Zhang Scott Greene Henrik Engdahl Peter W. Sauer POWER SYSTEMS ENGINEERING RESEARCH CENTER Electrical and Computer Engineering Department

  3. Effect of Y-211 particle size on the growth of single grain Y–Ba–Cu–O bulk superconductors

    E-Print Network [OSTI]

    Thoma, Max; Shi, Yunhua; Dennis, Tony; Durrell, John; Cardwell, David

    2014-12-01T23:59:59.000Z

    The engineering of fine Y2Ba1Cu1O5 (Y-211) inclusions of average particle size 1?2 ?m within the continuous, superconducting YBa2Cu3O7?? (Y-123) phase matrix of single-grain, bulk high temperature Y–Ba–Cu–O (YBCO) superconductors is fundamental...

  4. Bulk SmCo5/a-Fe nanocomposite permanent magnets fabricated by mould-free Joule-heating compaction

    E-Print Network [OSTI]

    Liu, J. Ping

    Bulk SmCo5/a-Fe nanocomposite permanent magnets fabricated by mould-free Joule-heating compaction and soft magnetic phases.1­3 The prerequisite for effective exchange coupling is a small grain size, which are used to produce single-phase microcrystalline permanent magnets, are ineffective in producing

  5. Graviton Emission in the Bulk by a Simply Rotating Black Hole

    E-Print Network [OSTI]

    P. Kanti; Hideo Kodama; R. A. Konoplya; N. Pappas; A. Zhidenko

    2010-06-07T23:59:59.000Z

    In this work, we study the emission of tensor-type gravitational degrees of freedom from a higher-dimensional, simply rotating black hole in the bulk. The decoupled radial part of the corresponding field equation is first solved analytically in the limit of low-energy emitted particles and low-angular momentum of the black hole in order to derive the absorption probability. Both the angular and radial equations are then solved numerically, and the comparison of the analytical and numerical results show a very good agreement in the low and intermediate energy regimes. By using our exact, numerical results we compute the energy and angular momentum emission rates and their dependence on the spacetime parameters such as the number of additional spacelike dimensions and the angular momentum of the black hole. Particular care is given to the convergence of our results in terms of the number of modes taken into account in the calculation, and the multiplicity of graviton tensor modes that correspond to the same angular-momentum numbers.

  6. Bulk Data Movement for Climate Dataset: Efficient Data Transfer Management with Dynamic Transfer Adjustment

    SciTech Connect (OSTI)

    Sim, Alexander; Balman, Mehmet; Williams, Dean; Shoshani, Arie; Natarajan, Vijaya

    2010-07-16T23:59:59.000Z

    Many scientific applications and experiments, such as high energy and nuclear physics, astrophysics, climate observation and modeling, combustion, nano-scale material sciences, and computational biology, generate extreme volumes of data with a large number of files. These data sources are distributed among national and international data repositories, and are shared by large numbers of geographically distributed scientists. A large portion of data is frequently accessed, and a large volume of data is moved from one place to another for analysis and storage. One challenging issue in such efforts is the limited network capacity for moving large datasets to explore and manage. The Bulk Data Mover (BDM), a data transfer management tool in the Earth System Grid (ESG) community, has been managing the massive dataset transfers efficiently with the pre-configured transfer properties in the environment where the network bandwidth is limited. Dynamic transfer adjustment was studied to enhance the BDM to handle significant end-to-end performance changes in the dynamic network environment as well as to control the data transfers for the desired transfer performance. We describe the results from the BDM transfer management for the climate datasets. We also describe the transfer estimation model and results from the dynamic transfer adjustment.

  7. DYNAMIC ANALYSIS OF THE BULK TRITIUM SHIPPING PACKAGE SUBJECTED TO CLOSURE TORQUES AND SEQUENTIAL IMPACTS

    SciTech Connect (OSTI)

    Wu, T; Paul Blanton, P; Kurt Eberl, K

    2007-07-09T23:59:59.000Z

    This paper presents a finite-element technique to simulate the structural responses and to evaluate the cumulative damage of a radioactive material packaging requiring bolt closure-tightening torque and subjected to the scenarios of the Hypothetical Accident Conditions (HAC) defined in the Code of Federal Regulations Title 10 part 71 (10CFR71). Existing finite-element methods for modeling closure stresses from bolt pre-load are not readily adaptable to dynamic analyses. The HAC events are required to occur sequentially per 10CFR71 and thus the evaluation of the cumulative damage is desirable. Generally, each HAC event is analyzed separately and the cumulative damage is partially addressed by superposition. This results in relying on additional physical testing to comply with 10CFR71 requirements for assessment of cumulative damage. The proposed technique utilizes the combination of kinematic constraints, rigid-body motions and structural deformations to overcome some of the difficulties encountered in modeling the effect of cumulative damage. This methodology provides improved numerical solutions in compliance with the 10CFR71 requirements for sequential HAC tests. Analyses were performed for the Bulk Tritium Shipping Package (BTSP) designed by Savannah River National Laboratory to demonstrate the applications of the technique. The methodology proposed simulates the closure bolt torque preload followed by the sequential HAC events, the 30-foot drop and the 30-foot dynamic crush. The analytical results will be compared to the package test data.

  8. Metallic magnetism and change of conductivity in the nano to bulk transition of cobalt ferrite

    SciTech Connect (OSTI)

    Arunkumar, A.; Vanidha, D.; Kannan, R., E-mail: kannan@pec.edu [Department of Physics, Pondicherry Engineering College, Puducherry–605 014 (India); Oudayakumar, K. [Department of Physics, Sri Manakula Vinayagar Engineering College, Puducherry–605 107 (India); Rajagopan, S. [Department of Chemistry, Pondicherry Engineering College, Puducherry–605 014 (India)

    2013-11-14T23:59:59.000Z

    Variations in conductivity with particle size have been observed in cobalt ferrite, when synthesized by solgel auto-combustion method. Impedance analysis reveals metallic and semiconducting behavior at room temperature for a particle size of 6?nm and 52?nm, respectively. Upon thermal activation, metallic to semiconducting phase transition has been observed as a function of particle size and vice-versa. Grainboundary Resistance (R{sub gb}), increased drastically with particle size (19?M? for 6?nm and 259?M? for 52?nm) at room temperature. AC conductivity and dielectric constants exhibit similar metallic to semiconducting phase transition at 6?nm and semiconducting behavior at 52?nm with temperature in the selected frequencies. Enhanced magnetic moment with an increase in the grain size along with decreased coercivity (1444?G to 1146?G) reveals transition from single domain to multi-domain. Increased inter-particle interaction is responsible for metallicity at the nano level and on the contrary semiconductivity is attributed to bulk.

  9. Time-resolved x-ray diffraction techniques for bulk polycrystalline materials under dynamic loading

    SciTech Connect (OSTI)

    Lambert, P. K.; Hustedt, C. J.; Zhao, M.; Ananiadis, A. G.; Hufnagel, T. C. [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Vecchio, K. S. [Department of NanoEngineering, University of California San Diego, La Jolla, California 92093 (United States); Huskins, E. L. [Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37830 (United States); US Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, Maryland 21005 (United States); Casem, D. T. [US Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, Maryland 21005 (United States); Gruner, S. M. [Department of Physics, Cornell University, Ithaca, New York 14853 (United States); Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York 14853 (United States); Kavli Institute at Cornell for Nanoscale Science, Cornell University, Ithaca, New York 14853 (United States); Tate, M. W.; Philipp, H. T.; Purohit, P.; Weiss, J. T. [Department of Physics, Cornell University, Ithaca, New York 14853 (United States); Woll, A. R. [Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, New York 14853 (United States); Kannan, V.; Ramesh, K. T. [Department of Mechanical Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Kenesei, P.; Okasinski, J. S.; Almer, J. [X-ray Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

    2014-09-15T23:59:59.000Z

    We have developed two techniques for time-resolved x-ray diffraction from bulk polycrystalline materials during dynamic loading. In the first technique, we synchronize a fast detector with loading of samples at strain rates of ?10{sup 3}–10{sup 4} s{sup ?1} in a compression Kolsky bar (split Hopkinson pressure bar) apparatus to obtain in situ diffraction patterns with exposures as short as 70 ns. This approach employs moderate x-ray energies (10–20 keV) and is well suited to weakly absorbing materials such as magnesium alloys. The second technique is useful for more strongly absorbing materials, and uses high-energy x-rays (86 keV) and a fast shutter synchronized with the Kolsky bar to produce short (?40??s) pulses timed with the arrival of the strain pulse at the specimen, recording the diffraction pattern on a large-format amorphous silicon detector. For both techniques we present sample data demonstrating the ability of these techniques to characterize elastic strains and polycrystalline texture as a function of time during high-rate deformation.

  10. Bulk thermodynamics and charge fluctuations at non-vanishing baryon density

    E-Print Network [OSTI]

    Chuan Miao; Christian Schmidt

    2007-10-23T23:59:59.000Z

    We present results on bulk thermodynamic quantities as well as net baryon number, strangeness and electric charge fluctuations in QCD at non-zero density and temperature obtained from lattice calculations with almost physical quark masses for two values of the lattice cut-off $aT=1/4$ and 1/6 . We show that with our improved p4fa3-action the cut-off effects are under control when using lattices with a temporal extent of 6 or larger and that the contribution to the equation of state, which is due to a finite chemical potential is small for $\\mu_q/T<1$. Moreover, at vanishing chemical potential, i.e. under conditions almost realized at RHIC and the LHC, quartic fluctuations of net baryon number and strangeness are large in a narrow temperature interval characterizing the transition region from the low to high temperature phase. At non-zero baryon number density, strangeness fluctuations are enhanced and correlated to fluctuations of the net baryon number. If strangeness is furthermore forced to vanish, as it may be the case in systems created in heavy ion collisions, strangeness fluctuations are significantly smaller than baryon number fluctuations.

  11. In-situ ductile metal/bulk metallic glass matrix composites formed by chemical partitioning

    DOE Patents [OSTI]

    Kim, Choong Paul (Northridge, CA); Hays, Charles C. (Pasadena, CA); Johnson, William L. (Pasadena, CA)

    2007-07-17T23:59:59.000Z

    A composite metal object comprises ductile crystalline metal particles in an amorphous metal matrix. An alloy is heated above its liquidus temperature. Upon cooling from the high temperature melt, the alloy chemically partitions, forming dendrites in the melt. Upon cooling the remaining liquid below the glass transition temperature it freezes to the amorphous state, producing a two-phase microstructure containing crystalline particles in an amorphous metal matrix. The ductile metal particles have a size in the range of from 0.1 to 15 micrometers and spacing in the range of from 0.1 to 20 micrometers. Preferably, the particle size is in the range of from 0.5 to 8 micrometers and spacing is in the range of from 1 to 10 micrometers. The volume proportion of particles is in the range of from 5 to 50% and preferably 15 to 35%. Differential cooling can produce oriented dendrites of ductile metal phase in an amorphous matrix. Examples are given in the Zr--Ti--Cu--Ni--Be alloy bulk glass forming system with added niobium.

  12. A paucity of bulk entangling surfaces: AdS wormholes with de Sitter interiors

    E-Print Network [OSTI]

    Sebastian Fischetti; Donald Marolf; Aron Wall

    2014-09-23T23:59:59.000Z

    We study and construct spacetimes, dubbed planar AdS-dS-wormholes, satisfying the null energy condition and having two asymptotically AdS boundaries connected through a (non-traversable) inflating wormhole. As for other wormholes, it is natural to expect dual descriptions in terms of two disconnected CFTs in appropriate entangled states. But for our cases certain expected bulk entangling surfaces used by the Hubeny-Rangamani-Takayanagi (HRT) prescription to compute CFT entropy do not exist. In particular, no real codimension-2 extremal surface can run from one end of the wormhole to the other. According to HRT, the mutual information between any two finite-sized subregions (one in each CFT) must then vanish at leading order in large $N$ -- though the leading-order mutual information per unit area between the two CFTs taken as wholes may be nonzero. Some planar AdS-dS-wormholes also fail to have plane-symmetric surfaces that would compute the total entropy of either CFT. We suggest this to remain true of less-symmetric surfaces so that the HRT entropy is ill-defined and some modified prescription is required. It may be possible to simply extend HRT or the closely-related maximin construction by a limiting procedure, though complex extremal surfaces could also play an important role.

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

    SciTech Connect (OSTI)

    Nieh, T.G.

    2012-07-31T23:59:59.000Z

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

  14. Thermal and Bulk Comptonization in Accretion-Powered X-Ray Pulsars

    E-Print Network [OSTI]

    Peter A. Becker; Michael T. Wolff

    2006-09-01T23:59:59.000Z

    We develop a new theoretical model for the spectral formation process in accretion-powered X-ray pulsars based on a detailed treatment of the bulk and thermal Comptonization occurring in the accreting, shocked gas. A rigorous eigenfunction expansion method is employed to obtain the analytical solution for the Green's function describing the scattering of radiation injected into the column from a monochromatic source located at an arbitrary height above the stellar surface. The emergent spectrum is calculated by convolving the Green's function with source terms corresponding to bremsstrahlung, cyclotron, and blackbody emission. The energization of the photons in the shock, combined with cyclotron absorption, naturally produces an X-ray spectrum with a relatively flat continuum shape and a high-energy quasi-exponential cutoff. We demonstrate that the new theory successfully reproduces the phase-averaged spectra of the bright pulsars Her X-1, LMC X-4, and Cen X-3. In these luminous sources, it is shown that the emergent spectra are dominated by Comptonized bremsstrahlung emission.

  15. Investigation on properties of ultrafast switching in a bulk gallium arsenide avalanche semiconductor switch

    SciTech Connect (OSTI)

    Hu, Long, E-mail: hulong-1226@126.com [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi'an Jiaotong University, Xi'an 710049 (China); Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China); Su, Jiancang; Ding, Zhenjie; Hao, Qingsong; Yuan, Xuelin [Science and Technology on High Power Microwave Laboratory, Northwest Institute of Nuclear Technology, Xi'an 710024 (China)

    2014-03-07T23:59:59.000Z

    Properties of ultrafast switching in a bulk gallium arsenide (GaAs) avalanche semiconductor switch based on semi-insulating wafer, triggered by an optical pulse, were analyzed using physics-based numerical simulations. It has been demonstrated that when a voltage with amplitude of 5.2?kV is applied, after an exciting optical pulse with energy of 1??J arrival, the structure with thickness of 650??m reaches a high conductivity state within 110 ps. Carriers are created due to photons absorption, and electrons and holes drift to anode and cathode terminals, respectively. Static ionizing domains appear both at anode and cathode terminals, and create impact-generated carriers which contribute to the formation of electron-hole plasma along entire channel. When the electric field in plasma region increases above the critical value (?4?kV/cm) at which the electrons drift velocity peaks, a domain comes into being. An increase in carrier concentration due to avalanche multiplication in the domains reduces the domain width and results in the formation of an additional domain as soon as the field outside the domains increases above ?4?kV/cm. The formation and evolution of multiple powerfully avalanching domains observed in the simulations are the physical reasons of ultrafast switching. The switch exhibits delayed breakdown with the characteristics affected by biased electric field, current density, and optical pulse energy. The dependence of threshold energy of the exciting optical pulse on the biased electric field is discussed.

  16. CLEARANCE OF BULK MATERIALS FROM D&D - LIFE AFTER THE NAS REPORT

    SciTech Connect (OSTI)

    Devgun, Jas S., Ph.D.

    2003-02-27T23:59:59.000Z

    Lack of consistent free release standards for solid materials has been an issue that has been around for several decades. The Nuclear Regulatory Commission (NRC) has had specific and dose-based standards for the release of liquids and gases for several decades, but no regulatory mechanisms for the release of solid materials from a nuclear power plant. Even though free releases of small quantities of solid materials continue under existing guidelines from operating plants, the regulatory void creates major difficulties for the bulk materials that result from decommissioning projects. For the nation's fleet of nuclear reactors the cost of this regulatory void could be as high as $10 billion. The NRC has recently resumed the enhanced rulemaking process that was originally initiated in 1999 but was deferred pending a study by the National Academy of Sciences (NAS)/National Research Council. The NAS report and recommendations were issued in March 2002 and the NRC decided in October 2002 to resume the rulemaking process. This paper provides an overview of the developments in this area. It specifically discusses the applicability of ANSI N13.12 as a consensus standard that should be seriously considered for adoption as a regulatory standard.

  17. MSSM dark matter and a light slepton sector: The Incredible Bulk

    E-Print Network [OSTI]

    Keita Fukushima; Chris Kelso; Jason Kumar; Pearl Sandick; Takahiro Yamamoto

    2014-12-10T23:59:59.000Z

    Recent experimental results from the LHC have placed strong constraints on the masses of colored superpartners. The MSSM parameter space is also constrained by the measurement of the Higgs boson mass, and the requirement that the relic density of lightest neutralinos be consistent with observations. Although large regions of the MSSM parameter space can be excluded by these combined bounds, leptophilic versions of the MSSM can survive these constraints. In this paper we consider a scenario in which the requirements of minimal flavor violation, vanishing $CP$-violation, and mass universality are relaxed, specifically focusing on scenarios with light sleptons. We find a large region of parameter space, analogous to the original bulk region, for which the lightest neutralino is a thermal relic with an abundance consistent with that of dark matter. We find that these leptophilic models are constrained by measurements of the magnetic and electric dipole moments of the electron and muon, and that these models have interesting signatures at a variety of indirect detection experiments.

  18. Corrosion and ion release behavior of ultra-fine grained bulk pure copper fabricated by ECAP in Hanks solution as potential biomaterial for contraception

    E-Print Network [OSTI]

    Zheng, Yufeng

    Corrosion and ion release behavior of ultra-fine grained bulk pure copper fabricated by ECAP-fine grained copper ECAP Corrosion behavior Ion release Ultra-fine grained (UFG) bulk pure copper has been revealed that the corrosion current of UFG copper ishigherthan that of the coarse grained copper

  19. Imprinted large-scale high density polymer nanopillars for organic solar cells

    E-Print Network [OSTI]

    Gao, Jinming

    Imprinted large-scale high density polymer nanopillars for organic solar cells Mukti Aryal used to make bulk heterojunction solar cells by depositing PCBM on top of the pillars. Imprinting provides a way to precisely control the interdigitized heterojunction morphology, leading to improved solar

  20. ORCED: A model to simulate the operations and costs of bulk-power markets

    SciTech Connect (OSTI)

    Hadley, S.; Hirst, E.

    1998-06-01T23:59:59.000Z

    Dramatic changes in the structure and operation of US bulk-power markets require new analytical tools. The authors developed the Oak Ridge Competitive Electricity Dispatch (ORCED) model to analyze a variety of public-policy issues related to the many changes underway in the US electricity industry. Such issues include: policy and technology options to reduce carbon emissions from electricity production; the effects of electricity trading between high- and low-cost regions on consumers and producers in both regions; the ability of the owners of certain generating units to exercise market power as functions of the transmission link between two regions and the characteristics of the generating units and loads in each region; and the market penetration of new energy-production and energy-use technologies and the effects of their adoption on fuel use, electricity use and costs, and carbon emissions. ORCED treats two electrical systems connected by a single transmission link ORCED uses two load-duration curves to represent the time-varying electricity consumption in each region. The two curves represent peak and offpeak seasons. User specification of demand elasticities permits ORCED to estimate the effects of changes in electricity price, both overall and hour by hour, on overall electricity use and load shapes. ORCED represents the electricity supply in each region with 26 generating units. The two regions are connected by a single transmission link. This link is characterized by its capacity (MW), cost ({cents}/kWh), and losses (%). This report explains the inputs to, outputs from, and operation of ORCED. It also presents four examples showing applications of the model to various public-policy issues related to restructuring of the US electricity industry.

  1. Effect of high strain rates on peak stress in a Zr-based bulk metallic glass

    SciTech Connect (OSTI)

    Sunny, George; Yuan Fuping; Prakash, Vikas [Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, Ohio 44106-7222 (United States); Lewandowski, John [Department of Materials Science and Engineering, Case Western Reserve University, Cleveland, Ohio 44106-7222 (United States)

    2008-11-01T23:59:59.000Z

    The mechanical behavior of Zr{sub 41.25}Ti{sub 13.75}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5} (LM-1) has been extensively characterized under quasistatic loading conditions; however, its mechanical behavior under dynamic loading conditions is currently not well understood. A Split-Hopkinson pressure bar (SHPB) and a single-stage gas gun are employed to characterize the mechanical behavior of LM-1 in the strain-rate regime of 10{sup 2}-10{sup 5}/s. The SHPB experiments are conducted with a tapered insert design to mitigate the effects of stress concentrations and preferential failure at the specimen-insert interface. The higher strain-rate plate-impact compression-and-shear experiments are conducted by impacting a thick tungsten carbide (WC) flyer plate with a sandwich sample comprising a thin bulk metallic glass specimen between two thicker WC target plates. Specimens employed in the SHPB experiments failed in the gage-section at a peak stress of approximately 1.8 GPa. Specimens in the high strain-rate plate-impact experiments exhibited a flow stress in shear of approximately 0.9 GPa, regardless of the shear strain-rate. The flow stress under the plate-impact conditions was converted to an equivalent flow stress under uniaxial compression by assuming a von Mises-like material behavior and accounting for the plane strain conditions. The results of these experiments, when compared to the previous work conducted at quasistatic loading rates, indicate that the peak stress of LM-1 is essentially strain rate independent over the strain-rate range up to 10{sup 5}/s.

  2. Quantum Monte Carlo benchmark of exchange-correlation functionals for bulk water

    SciTech Connect (OSTI)

    Morales, Miguel A [Lawrence Livermore National Laboratory (LLNL); Gergely, John [University of Illinois, Urbana-Champaign; McMinis, Jeremy [Lawrence Livermore National Laboratory (LLNL); McMahon, Jeffrey [University of Illinois, Urbana-Champaign; Kim, Jeongnim [ORNL; Ceperley, David M. [University of Illinois, Urbana-Champaign

    2014-01-01T23:59:59.000Z

    The accurate description of the thermodynamic and dynamical properties of liquid water from first-principles is a very important challenge to the theoretical community. This represents not only a critical test of the predictive capabilities of first-principles methods, but it will also shed light into the microscopic properties of such an important substance. Density Functional Theory, the main workhorse in the field of first-principles methods, has been so far unable to properly describe water and its unusual properties in the liquid state. With the recent introduction of exact exchange and an improved description of dispersion interaction, the possibility of an accurate description of the liquid is finally within reach. Unfortunately, there is still no way to systematically improve exchange-correlation functionals and the number of available functionals is very large. In this article we use highly accurate quantum Monte Carlo calculations to benchmark a selection of exchange-correlation functionals typically used in Density Functional Theory simulations of bulk water. This allows us to test the predictive capabilities of these functionals in water, giving us a way not only to choose optimal functionals for first-principles simulations, but also giving us a route for the optimization of the functionals for the system at hand. We compare and contrast the importance of different features of functionals, including the hybrid component, the vdW component, and their importance within different aspects of the PES. In addition, we test a recently introduce scheme that combines Density Functional Theory with Coupled Cluster Calculations through a Many-Body expansion of the energy, in order to correct the inaccuracies in the description of short range interactions in the liquid.

  3. Classical Tests of General Relativity: Probing Topologically Charged Black Holes on Brane Worlds in f(R) Bulk

    E-Print Network [OSTI]

    Roldao da Rocha; A. M. Kuerten

    2014-07-08T23:59:59.000Z

    The perihelion precession, the deflection of light, and the radar echo delay are classical tests of General Relativity here used to probe brane world topologically charged black holes in a f(R) bulk and to constrain the parameter that arises from the Shiromizu-Maeda-Sasaki procedure applied to a f(R) bulk as well. The existing Solar system observational data constrain the possible values of the tidal charge parameter and the effective cosmological constant including f(R) brane world effects. We show that the observational/experimental data for both perihelion precession and radar echo delay make the black hole space of parameters to be more strict than the ones for the Dadhich, Maartens, Papadopoulos and Rezania (DMPR) black hole geometry. Furthermore, the deflection of light constrains the tidal charge parameter similarly as the DMPR black holes due to a peculiarity in the equation of motion.

  4. Van der Waals density-functional theory study for bulk solids with BCC, FCC, and diamond structures

    E-Print Network [OSTI]

    Park, Jinwoo; Hong, Suklyun

    2015-01-01T23:59:59.000Z

    Proper inclusion of van der Waals (vdW) interactions in theoretical simulations based on standard density functional theory (DFT) is crucial to describe the physics and chemistry of systems such as organic and layered materials. Many encouraging approaches have been proposed to combine vdW interactions with standard approximate DFT calculations. Despite many vdW studies, there is no consensus on the reliability of vdW methods. To help further development of vdW methods, we have assessed various vdW functionals through the calculation of structural prop- erties at equilibrium, such as lattice constants, bulk moduli, and cohesive energies, for bulk solids, including alkali, alkali-earth, and transition metals, with BCC, FCC, and diamond structures as the ground state structure. These results provide important information for the vdW-related materials research, which is essential for designing and optimizing materials systems for desired physical and chemical properties.

  5. hal-00133055,version1-29Mar2007 Nuclear spin interferences in bulk water at room temperature.

    E-Print Network [OSTI]

    Boyer, Edmond

    hal-00133055,version1-29Mar2007 Nuclear spin interferences in bulk water at room temperature. J in NMR pacs 03.67.-a: Quantum information pacs 67.57.Lm: Spin dynamics Abstract Nuclear spin interference in a static mag- netic field B0 4.7 T. For a homogeneity of B0 of the order of B0/B0 = 2 · 10-8 , the nuclear

  6. DEVELOPMENT OF A TAMPER RESISTANT/INDICATING AEROSOL COLLECTION SYSTEM FOR ENVIRONMENTAL SAMPLING AT BULK HANDLING FACILITIES

    SciTech Connect (OSTI)

    Sexton, L.

    2012-06-06T23:59:59.000Z

    Environmental sampling has become a key component of International Atomic Energy Agency (IAEA) safeguards approaches since its approval for use in 1996. Environmental sampling supports the IAEA's mission of drawing conclusions concerning the absence of undeclared nuclear material or nuclear activities in a Nation State. Swipe sampling is the most commonly used method for the collection of environmental samples from bulk handling facilities. However, augmenting swipe samples with an air monitoring system, which could continuously draw samples from the environment of bulk handling facilities, could improve the possibility of the detection of undeclared activities. Continuous sampling offers the opportunity to collect airborne materials before they settle onto surfaces which can be decontaminated, taken into existing duct work, filtered by plant ventilation, or escape via alternate pathways (i.e. drains, doors). Researchers at the Savannah River National Laboratory and Oak Ridge National Laboratory have been working to further develop an aerosol collection technology that could be installed at IAEA safeguarded bulk handling facilities. The addition of this technology may reduce the number of IAEA inspector visits required to effectively collect samples. The principal sample collection device is a patented Aerosol Contaminant Extractor (ACE) which utilizes electrostatic precipitation principles to deposit particulates onto selected substrates. Recent work has focused on comparing traditional swipe sampling to samples collected via an ACE system, and incorporating tamper resistant and tamper indicating (TRI) technologies into the ACE system. Development of a TRI-ACE system would allow collection of samples at uranium/plutonium bulk handling facilities in a manner that ensures sample integrity and could be an important addition to the international nuclear safeguards inspector's toolkit. This work was supported by the Next Generation Safeguards Initiative (NGSI), Office of Nonproliferation and International Security (NIS), National Nuclear Security Administration (NNSA).

  7. Heavy duty insulator assemblies for 500-kV bulk power transmission line with large diameter octagonalbundled conductor

    SciTech Connect (OSTI)

    Tsujimoto, K.; Hayase, I.; Hirai, J.; Inove, M.; Naito, K.; Yukino, T.

    1982-11-01T23:59:59.000Z

    This paper describes the design procedure and the results of field tests on mechanical performances of insulator assemblies newly developed to support octagonal-bundled conductors for 500-kV bulk power transmission. Taking account of conductor-motion-induced peak tensile load, fatigue, torsional torque and others, a successful design has been achieved in two prototype assemblies for such heavy mechanical duties as encountered during conductor galloping or swing. This has been proved throughout three years of the field tests.

  8. Characterization and assessment of novel bulk storage technologies : a study for the DOE Energy Storage Systems program.

    SciTech Connect (OSTI)

    Huff, Georgianne; Tong, Nellie (KEMA Consulting, Fairfax, VA); Fioravanti, Richard (KEMA Consulting, Fairfax, VA); Gordon, Paul (Sentech/SRA International, Bethesda, MD); Markel, Larry (Sentech/SRA International, Bethesda, MD); Agrawal, Poonum (Sentech/SRA International, Bethesda, MD); Nourai, Ali (KEMA Consulting, Fairfax, VA)

    2011-04-01T23:59:59.000Z

    This paper reports the results of a high-level study to assess the technological readiness and technical and economic feasibility of 17 novel bulk energy storage technologies. The novel technologies assessed were variations of either pumped storage hydropower (PSH) or compressed air energy storage (CAES). The report also identifies major technological gaps and barriers to the commercialization of each technology. Recommendations as to where future R&D efforts for the various technologies are also provided based on each technology's technological readiness and the expected time to commercialization (short, medium, or long term). The U.S. Department of Energy (DOE) commissioned this assessment of novel concepts in large-scale energy storage to aid in future program planning of its Energy Storage Program. The intent of the study is to determine if any new but still unproven bulk energy storage concepts merit government support to investigate their technical and economic feasibility or to speed their commercialization. The study focuses on compressed air energy storage (CAES) and pumped storage hydropower (PSH). It identifies relevant applications for bulk storage, defines the associated technical requirements, characterizes and assesses the feasibility of the proposed new concepts to address these requirements, identifies gaps and barriers, and recommends the type of government support and research and development (R&D) needed to accelerate the commercialization of these technologies.

  9. Effect of milling time on magnetic properties and structures of bulk Sm-Co/{alpha}-(Fe, Co) nanocomposite magnets

    SciTech Connect (OSTI)

    Shen, Y. [UDRI, University of Dayton, Dayton, Ohio 45469 (United States); AFRL, Wright-Patterson Air Force Base, Ohio 45433 (United States); Huang, M. Q.; Turgut, Z. [AFRL, Wright-Patterson Air Force Base, Ohio 45433 (United States); UES Inc., Dayton, Ohio 45432 (United States); Lucas, M. S. [AFRL, Wright-Patterson Air Force Base, Ohio 45433 (United States); UTC, Dayton, Ohio 45432 (United States); Michel, E. [AFRL, Wright-Patterson Air Force Base, Ohio 45433 (United States); Wright State University, Dayton, Ohio 45435 (United States); Horwath, J. C. [AFRL, Wright-Patterson Air Force Base, Ohio 45433 (United States)

    2012-04-01T23:59:59.000Z

    Bulk Sm-Co/{alpha}-(Fe,Co) nanocomposite magnets were fabricated by hot pressing composite powders prepared by high-energy ball milling of magnetically hard SmCo{sub 5} powder and magnetically soft Fe powder. The bulk magnets had a nanocomposite structure consisting of Sm-Co matrix (1:5 H and 1:7 H phases) and {alpha}-(Fe,Co) phases. The Fe-Co particles were distributed uniformly in the Sm-Co matrix. The milling time strongly affects the structures and the magnetic properties of the bulk magnets. Increasing milling time led to a decrease of the amount of 1:5 H phase, an increase in the phase fraction of the 1:7 H phase, and a decrease in the amount of soft phase, which resulted in an increase in magnetization and a decrease in coercivity. Scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS) analyses revealed that inter-diffusion took place between the Sm-Co matrix and Fe particles during the processing.

  10. STATUS & DIRECTION OF THE BULK VITRIFICATION PROGRAM FOR THE SUPPLEMENTAL TREATMENT OF LOW ACTIVITY TANK WASTE AT HANFORD

    SciTech Connect (OSTI)

    RAYMOND, R.E.

    2005-01-12T23:59:59.000Z

    The DOE Office of River Protection (ORP) is managing a program at the Hanford site that will retrieve and treat more than 200 million liters (53 million gal.) of radioactive waste stored in underground storage tanks. The waste was generated over the past 50 years as part of the nation's defense programs. The project baseline calls for the waste to be retrieved from the tanks and partitioned to separate the highly radioactive constituents from the large volumes of chemical waste. These highly radioactive components will be vitrified into glass logs in the Waste Treatment Plant (WTP), temporarily stored on the Hanford Site, and ultimately disposed of as high-level waste in the offsite national repository. The less radioactive chemical waste, referred to as low-activity waste (LAW), is also planned to be vitrified by the WTP, and then disposed of in approved onsite trenches. However, additional treatment capacity is required in order to complete the pretreatment and immobilization of the tank waste by 2028, which represents a Tri-Party Agreement milestone. To help ensure that the treatment milestones will be met, the Supplemental Treatment Program was undertaken. The program, managed by CH2M HILL Hanford Group, Inc., involves several sub-projects each intended to supplement part of the treatment of waste being designed into the WTP. This includes the testing, evaluation, design, and deployment of supplemental LAW treatment and immobilization technologies, retrieval and treatment of mixed TRU waste stored in the Hanford Tanks, and supplemental pre-treatment. Applying one or more supplemental treatment technologies to the LAW has several advantages, including providing additional processing capacity, reducing the planned loading on the WTP, and reducing the need for double-shell tank space for interim storage of LAW. In fiscal year 2003, three potential supplemental treatment technologies were evaluated including grout, steam reforming and bulk vitrification using AMEC's In-Container Vitrification{trademark} process. As an outcome of this work, the hulk vitrification process was recommended for further evaluation. In fiscal year 2004, a follow-on bulk vitrification project was initiated to design, procure, assemble and operate a full-scale bulk vitrification pilot-plant to treat low activity tank waste from Hanford tank 241-S-109 under a Research, Development and Demonstration permit. That project is referred to as the Demonstration Bulk Vitrification System (or DBVS). The DBVS project will provide a full-scale bulk vitrification demonstration facility that can be used to assess the effectiveness of the bulk vitrification process under actual operating conditions. The pilot-plant is scheduled to commence operations in late 2005. The Supplemental Treatment Program represents a major element of the ORP's strategy to complete the pretreatment and immobilization of tank wastes by 2028. This paper will provide an overview of the bulk vitrification process and the progress in establishing the pilot-plant.

  11. Progress Report on the Laboratory Testing of the Bulk Vitrification Cast Refractory

    SciTech Connect (OSTI)

    Pierce, Eric M.; McGrail, B PETER.; Bagaasen, Larry M.; Wellman, Dawn M.; Crum, J V.; Geiszler, Keith N.; Baum, Steven R.

    2004-11-15T23:59:59.000Z

    The Hanford Site in southeastern Washington State has been used extensively to produce nuclear materials for the U. S. strategic defense arsenal by the U. S. Department of Energy (DOE). A large inventory of radioactive and mixed waste has accumulated in 177 single- and double-shell tanks. Liquid waste recovered from the tanks will be pre-treated to separate the low-activity fraction from the high-level and transuranic wastes. Currently, the DOE Office of River Protection (ORP) is evaluating several options for immobilization of low-activity tank wastes for eventual disposal in a shallow subsurface facility at the Hanford Site. A significant portion of the waste will be converted into immobilized low-activity waste (ILAW) glass with a conventional Joule-heated ceramic melter. In addition to ILAW glass, supplemental treatment technologies are under consideration by the DOE to treat a portion of the low activity waste. The reason for using this alternative treatment technology is to accelerate the overall cleanup mission at the Hanford site. The ORP selected Bulk Vitrification (BV) for further development and testing. Work in FY03 on engineered and large scale tests of the BV process suggested that approximately 0.3 to as much as 3 wt% of the waste stream 99Tc inventory would end up in a soluble form deposited in a vesicular layer located at the top of the BV melt and in the sand used as an insulator after vitrification. In the FY03 risk assessment (RA) (Mann et al., 2003), the soluble Tc salt in the BV waste packages creates a 99Tc concentration peak at early times in the groundwater extracted from a 100-meter down-gradient well. This peak differs from the presently predicted baseline WTP glass performance, which shows an asymptotic rise to a constant release rate. Because of the desire by regulatory agencies to achieve essentially equivalent performance to WTP glass with supplemental treatment technologies, the BV process was modified in FY04 in an attempt to minimize deposition of soluble 99Tc salts by including a castable refractory block (CRB) in place of a portion of the refractory sand layer and using a bottom-up melting technique to eliminate the vesicular glass layer at the top. However, the refractory block is still porous and there is the potential for leachable 99Tc to deposit in the pores of the CRB. The purpose of this progress report is to document the status of a laboratory testing program being conducted at Pacific Northwest National Laboratory (PNNL) for CH2M Hill Hanford Group in support of the LAW Supplemental Treatment Technologies Demonstration project. The objective of these tests was to provide an initial estimate of the leachable fraction of key contaminants of concern (Cs, Re [chemical analogue for 99Tc], and 99Tc) that could condense within the BV CRB. This information will be used to guide development of additional modifications to the BV process to further reduce the soluble 99Tc levels in the BV waste package.

  12. High performance organic photovoltaic cells with blade-coated active layers Siew-Lay Lim a

    E-Print Network [OSTI]

    Organic bulk heterojunction photovoltaic (PV) cells are pro- mising renewable energy alternatives-weight and versatile products, such as portable battery chargers and window shades in building integrated photovoltaic

  13. Kelvin Probe Force Microscopy for in situ Electrical Characterization of Organic Solar Cells

    E-Print Network [OSTI]

    Fisher, Frank

    Kelvin Probe Force Microscopy for in situ Electrical Characterization of Organic Solar Cells., University of Pittsburgh The most efficient organic solar cell today is made from blending conjugated donors and acceptors in bulk heterojunction organic solar cells. Most microscopic characterization

  14. Nanostructured architectures for colloidal quantum dot solar cells

    E-Print Network [OSTI]

    Jean, Joel, S.M. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    This thesis introduces a novel ordered bulk heterojunction architecture for colloidal quantum dot (QD) solar cells. Quantum dots are solution-processed nanocrystals whose tunable bandgap energies make them a promising ...

  15. COARSE-GRAINED REFRACTORY INCLUSIONS: CONDENSATES, EVAPORATION RESIDUES, OR BOTH? EVIDENCE FROM MAJOR ELEMENT BULK COMPOSITIONS. S. B. Simon, D. S. Ebel, L. Grossman1

    E-Print Network [OSTI]

    Grossman, Lawrence

    COARSE-GRAINED REFRACTORY INCLUSIONS: CONDENSATES, EVAPORATION RESIDUES, OR BOTH? EVIDENCE FROM from bulk equilibrium condensates calculated for a gas of solar composition. Literature data for major expected from equilibrium condensation. We also performed thermodynamic calculations to evaluate the degree

  16. Density scaling of the diffusivity in viscous liquids: Identification of the scaling exponent with the pressure derivative of the isothermal bulk modulus

    E-Print Network [OSTI]

    Anthony N. Papathanassiou; Ilias Sakellis

    2009-09-20T23:59:59.000Z

    A density scaled diffusivity function for viscous liquids derived earlier [Phys. Rev. E 79, 032501 (2009)] is revisited, based on an improved equation of state assuming that the isothermal bulk modulus increases linearly with pressure. Without making any assumption on the interconnection between the scaling exponent and the Gruneisen parameter, we prove that the scaling exponent is identical with the pressure derivative of the isothermal bulk modulus. We further discuss probable interconnection between the scaling exponent and the Gruneisen parameter.meter.

  17. Phase behavior of carbon dioxide confined in silica aerogel in the vicinity of the bulk critical point

    SciTech Connect (OSTI)

    Ciccariello, Salvino [Universita di Padova; Melnichenko, Yuri B [ORNL; He, Lilin [ORNL

    2011-01-01T23:59:59.000Z

    The small angle neutron scattering intensities from silica aerogel filled with carbon dioxide at different loading densities of the bulk fluid (0.3-0.65 g/cm{sup 3}) were measured at fixed volume condition as a function of decreasing temperature, from 35 to 25 C, to characterize the phase behavior of the confined CO2 about the critical point of the bulk CO{sub 2}. The data present no evidence of a bulklike phase transition of the confined CO{sub 2} in the explored parameter region. They show that the confined CO{sub 2} may be approximated as a two phase system. The first phase (liquid film) is formed by CO{sub 2} molecules at the silica surface, and the second phase (confined fluid) fills up the rest of the pore volume. The thickness {delta} of the liquid film as well as the scattering-length densities of the two phases were obtained by analyzing the Porod invariants and the oscillations observed in the Porod plots at each loading density and temperature. The resulting {delta} values vary in the range 25-45 {angstrom} depending on the temperature and loading density. The density of the liquid film is 1.5-2 times larger than that of the confined fluid, which in its turn exceeds the density of bulk CO{sub 2} at similar temperature and pressure. At the lowest temperature (25 C), the densities of the liquid film and confined fluid respectively approach 1.25 g/cm{sup 3} and 0.8 g/cm{sup 3} independently of the loading conditions.

  18. On the Klein-Gordon equation near a De Sitter brane in an Anti-de Sitter bulk

    E-Print Network [OSTI]

    Alain Bachelot

    2014-06-29T23:59:59.000Z

    In this paper we investigate the Klein-Gordon equation in the past causal domain of a De Sitter brane imbedded in a Anti-de Sitter bulk. We solve the global mixed hyperbolic problem. We prove that any finite energy solution can be expressed as a Kaluza-Klein tower that is a superposition of free fields in the Steady State Universe, of which we study the asymptotic behaviours. We show that the leading term of a gravitational fluctuation is a massless graviton, i.e. the De Sitter brane is linearly stable.

  19. Multi-parameter on-line coal bulk analysis. Technical progress report, March 16, 1995--June 15, 1995

    SciTech Connect (OSTI)

    NONE

    1995-10-01T23:59:59.000Z

    Research continued on multi-parameter on-line coal bulk analysis. The thermal neutron flux distribution in coal and free air for two types of neutron sources was performed. The MCNP code was used to calculate the gamma ray response function and to determine the thermal neutron flux in coal when a lead collimator was used and when paraffin blocks were placed in front of the sample. The identification of chlorine in coal is discussed along with the analysis of the gamma spectra.

  20. Differentiation of Bulk and Surface Events in p-type Point-Contact Germanium Detectors for Light WIMP Searches

    E-Print Network [OSTI]

    H. B. Li; the TEXONO Collaboration

    2014-03-13T23:59:59.000Z

    The p-type point-contact germanium detectors are novel techniques offering kg-scale radiation sensors with sub-keV sensitivities. They have been used for light Dark Matter WIMPs searches and may have potential applications in neutrino physics. There are, however, anomalous surface behaviour which needs to be characterized and understood. We describe the methods and results of a research program whose goals are to identify the bulk and surface events via software pulse shape analysis techniques, and to devise calibration schemes to evaluate the selection efficiency factors. Efficiencies-corrected background spectra from the low-background facility at Kuo-Sheng Neutrino Laboratory are derived.

  1. High temperature electron spin dynamics in bulk cubic GaN: Nanosecond spin lifetimes far above room-temperature

    SciTech Connect (OSTI)

    Buß, J. H.; Schaefer, A.; Hägele, D.; Rudolph, J. [Arbeitsgruppe Spektroskopie der kondensierten Materie, Ruhr-Universität Bochum, Universitätsstraße 150, D-44780 Bochum (Germany); Schupp, T.; As, D. J. [Department of Physics, University of Paderborn, Warburger Str. 100, D-33095 Paderborn (Germany)

    2014-11-03T23:59:59.000Z

    The electron spin dynamics in n-doped bulk cubic GaN is investigated for very high temperatures from 293?K up to 500?K by time-resolved Kerr-rotation spectroscopy. We find extraordinarily long spin lifetimes exceeding 1?ns at 500?K. The temperature dependence of the spin relaxation time is in qualitative agreement with predictions of Dyakonov-Perel theory, while the absolute experimental times are an order of magnitude shorter than predicted. Possible reasons for this discrepancy are discussed, including the role of phase mixtures of hexagonal and cubic GaN as well as the impact of localized carriers.

  2. Thermodynamics of fission products in dispersion fuel designs - first principles modeling of defect behavior in bulk and at interfaces

    SciTech Connect (OSTI)

    Liu, Xiang-yand [Los Alamos National Laboratory; Uberuaga, Blas P [Los Alamos National Laboratory; Nerikar, Pankaj [Los Alamos National Laboratory; Sickafus, Kurt E [Los Alamos National Laboratory; Stanek, Chris R [Los Alamos National Laboratory

    2009-01-01T23:59:59.000Z

    Density functional theory (DFT) calculations of fission product (Xe, Sr, and Cs) incorporation and segregation in alkaline earth metal oxides, HfO{sub 2} and UO{sub 2} oxides, and the MgO/(U, Hf, Ce)O{sub 2} interfaces have been carried out. In the case of UO{sub 2}, the calculations were performed using spin polarization and with a Hubbard U term characterizing the on-sit Coulomb repulsion between the localized 5f electrons. The fission product solution energies in bulk UO{sub 2{+-}x} have been calculated as a function of non-stoichiometry x, and were compared to that in MgO. These calculations demonstrate that the fission product incorporation energies in MgO are higher than in HfO{sub 2}. However, this trend is reversed or reduced for alkaline earth oxides with larger cation sizes. The solution energies of fission products in MgO are substantially higher than in UO{sub 2{+-}x}, except for the case of Sr in the hypostoichiometric case. Due to size effects, the thermodynamic driving force of segregation for Xe and Cs from bulk MgO to the MgO/fluorite interface is strong. However, this driving force is relatively weak for Sr.

  3. CONSTRAINING THE BULK LORENTZ FACTOR OF GAMMA-RAY BURST OUTFLOW IN THE MAGNETIC-DOMINATED JET MODEL

    SciTech Connect (OSTI)

    Chang Zhe; Lin Hainan; Jiang Yunguo, E-mail: changz@ihep.ac.cn, E-mail: linhn@ihep.ac.cn, E-mail: jiangyg@ihep.ac.cn [Institute of High Energy Physics, Chinese Academy of Sciences, 100049 Beijing (China)

    2012-11-10T23:59:59.000Z

    Recent observations by the Fermi-LAT showed that there are delayed arrivals of GeV photons relative to the onset of MeV photons in some gamma-ray bursts (GRBs). In order to avoid a large optical depth, the minimal value of the Lorentz factor has been estimated to be higher than 1000 in some of the brightest bursts. In this paper, we present a detailed calculation of the time delay between the MeV and GeV photons in the framework of the magnetic-dominated jet model. We find that the time delay strongly depends on the saturated bulk Lorentz factor of the jet. Inspired by this fact, we use this model to calculate the Lorentz factors of the four brightest Fermi bursts. The results indicate that the Lorentz factors are much smaller than those obtained from the 'single-zone' scenario. The short burst GRB 090510 has a minimal Lorentz factor of 385, while the three long bursts, GRB 080916c, GRB 090902b, and GRB 090926, have almost the same Lorentz factors with an average value near 260. Another interesting result is that, for long bursts, GeV photons are emitted after the bulk Lorentz factor saturates. For the short GRB, however, MeV and GeV photons are emitted at the same phase, i.e., either in the expansion phase or in the coasting phase.

  4. Semiconductor heterojunction band offsets and charge neutrality

    E-Print Network [OSTI]

    Lee, Chomsik

    2012-06-07T23:59:59.000Z

    involving lasers, light emitting diodes, and metal-semiconductor field effect transistors, the models of Schottky and Bardeen correspond only to limiting cases, in which the energy barriers for electrons at the interface respectively vary linearly... of metal-lead sulfide contacts on the polarity of the applied voltage. In the 1930's, Tamm, Mott, Schottky and others developed the basic theory related to surface and interface semiconductor properties. Schottky introduced the first modern model Journal...

  5. Pulsed laser deposition of epitaxial yttrium iron garnet films with low Gilbert damping and bulk-like magnetization

    SciTech Connect (OSTI)

    Onbasli, M. C., E-mail: onbasli@mit.edu; Kim, D. H.; Ross, C. A. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139 (United States); Kehlberger, A. [Institute of Physics, Johannes Gutenberg-University of Mainz, 55099 Mainz (Germany); Graduate School Materials Science in Mainz, Staudinger Weg 9, 55128 Mainz (Germany); Jakob, G.; Kläui, M. [Institute of Physics, Johannes Gutenberg-University of Mainz, 55099 Mainz (Germany); Chumak, A. V.; Hillebrands, B. [Fachbereich Physik and Landesforschungszentrum, OPTIMAS, Technische Universität Kaiserslautern, 67663 Kaiserslautern (Germany)

    2014-10-01T23:59:59.000Z

    Yttrium iron garnet (YIG, Y {sub 3}Fe{sub 5}O{sub 12}) films have been epitaxially grown on Gadolinium Gallium Garnet (GGG, Gd{sub 3}Ga{sub 5}O{sub 12}) substrates with (100) orientation using pulsed laser deposition. The films were single-phase, epitaxial with the GGG substrate, and the root-mean-square surface roughness varied between 0.14 nm and 0.2 nm. Films with thicknesses ranging from 17 to 200 nm exhibited low coercivity (<2 Oe), near-bulk room temperature saturation moments (?135 emu cm{sup ?3}), in-plane easy axis, and damping parameters as low as 2.2 × 10{sup ?4}. These high quality YIG thin films are useful in the investigation of the origins of novel magnetic phenomena and magnetization dynamics.

  6. Development of bulk-type all-solid-state lithium-sulfur battery using LiBH{sub 4} electrolyte

    SciTech Connect (OSTI)

    Unemoto, Atsushi, E-mail: unemoto@imr.tohoku.ac.jp; Ikeshoji, Tamio [WPI-Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Yasaku, Syun; Matsuo, Motoaki [Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Nogami, Genki; Tazawa, Masaru; Taniguchi, Mitsugu [Mitsubishi Gas Chemicals Co., Ltd., 182 Tayuhama Shinwari, Kita-ku, Niigata 950-3112 (Japan); Orimo, Shin-ichi [WPI-Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2014-08-25T23:59:59.000Z

    Stable battery operation of a bulk-type all-solid-state lithium-sulfur battery was demonstrated by using a LiBH{sub 4} electrolyte. The electrochemical activity of insulating elemental sulfur as the positive electrode was enhanced by the mutual dispersion of elemental sulfur and carbon in the composite powders. Subsequently, a tight interface between the sulfur-carbon composite and the LiBH{sub 4} powders was manifested only by cold-pressing owing to the highly deformable nature of the LiBH{sub 4} electrolyte. The high reducing ability of LiBH{sub 4} allows using the use of a Li negative electrode that enhances the energy density. The results demonstrate the interface modification of insulating sulfur and the architecture of an all-solid-state Li-S battery configuration with high energy density.

  7. Process architectures using MeV implanted blanket buried layers for latch-up improvements on bulk silicon

    SciTech Connect (OSTI)

    Rubin, L.M.; Simonton, R.B.; Wilson, S.D. [Eaton Corporation, Beverly, MA (United States); Morris, W. [Silicon Engineering, Austin, TX (United States)

    1996-12-31T23:59:59.000Z

    Doped buried layers formed by MeV ion implantation are attractive alternatives to expensive epitaxial substrates for controlling latch-up in CMOS devices. Two different process architecture approaches for forming effective buried layers are discussed. P+ Around Boundary (PAB), and a more recent derivative, BILLI are compared to a Buried Layer/Connecting Layer (BUCL) architecture, with regards to latch-up resistance, process flexibility, and future scalability. While both architectures have been shown to increase latch-up trigger current on bulk silicon, the BUCL process provides greater latch-up control and process/device flexibility. Process and device simulations as well as experimental data indicate that a properly chosen set of implants for both n-well, p-well, and buried layer structures can yield latch-up isolation superior to 3mm epi.

  8. Bulk Viscosity driven clusterization of quark-gluon plasma and early freeze-out in relativistic heavy-ion collisions

    E-Print Network [OSTI]

    Giorgio Torrieri; Boris Tomasik; Igor Mishustin

    2008-02-26T23:59:59.000Z

    We introduce a new scenario for heavy ion collisions that could solve the lingering problems associated with the so-called HBT puzzle. We postulate that the system starts expansion as the perfect quark-gluon fluid but close to freeze-out it splits into clusters, due to a sharp rise of bulk viscosity in the vicinity of the hadronization transition. We then argue that the characteristic cluster size is determined by the viscosity coefficient and the expansion rate. Typically it is much smaller and independent of the total system volume. These clusters maintain the pre-existing outward-going flow, as a spray of droplets, but develop no flow of their own, and hadronize by evaporation. We provide an ansatz for converting the hydrodynamic output into clusters.

  9. Bulk Viscosity driven clusterization of quark-gluon plasma and early freeze-out in relativistic heavy-ion collisions

    E-Print Network [OSTI]

    Torrieri, G; Mishustin, I

    2007-01-01T23:59:59.000Z

    We introduce a new scenario for heavy ion collisions that could solve the lingering problems associated with the so-called HBT puzzle. We postulate that the system starts expansion as the perfect quark-gluon fluid but close to freeze-out it splits into clusters, due to a sharp rise of bulk viscosity in the vicinity of the hadronization transition. We then argue that the characteristic cluster size is determined by the viscosity coefficient and the expansion rate. Typically it is much smaller and independent of the total system volume. These clusters maintain the pre-existing outward-going flow, as a spray of droplets, but develop no flow of their own, and hadronize by evaporation. We provide an ansatz for converting the hydrodynamic output into clusters.

  10. Charging and de-charging of dust particles in bulk region of a radio frequency discharge plasma

    SciTech Connect (OSTI)

    Mishra, S. K. [Institute for Plasma Research, Gandhinagar 382428 (India); Misra, Shikha; Sodha, M. S. [Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi 110016 (India)

    2013-03-15T23:59:59.000Z

    An analysis to investigate the effect of the dust particle size and density on the floating potential of the dust particles of uniform radius and other plasma parameters in the bulk region plasma of a RF-discharge in collisionless/collisional regime has been presented herein. For this purpose, the average charge theory based on charge balance on dust and number balance of plasma constituents has been utilized; a derivation for the accretion rate of electrons corresponding to a drifting Maxwellian energy distribution in the presence of an oscillatory RF field has been given and the resulting expression has been used to determine the floating potential of the dust grains. Further, the de-charging of the dust grains after switching off the RF field has also been discussed.

  11. TECHNICAL ASSESSMENT OF BULK VITRIFICATION PROCESS & PRODUCT FOR TANK WASTE TREATMENT AT THE DEPARTMENT OF ENERGY HANFORD SITE

    SciTech Connect (OSTI)

    SCHAUS, P.S.

    2006-07-21T23:59:59.000Z

    At the U.S. Department of Energy (DOE) Hanford Site, the Waste Treatment Plant (WTP) is being constructed to immobilize both high-level waste (IUW) for disposal in a national repository and low-activity waste (LAW) for onsite, near-surface disposal. The schedule-controlling step for the WTP Project is vitrification of the large volume of LAW, current capacity of the WTP (as planned) would require 50 years to treat the Hanford tank waste, if the entire LAW volume were to be processed through the WTP. To reduce the time and cost for treatment of Hanford Tank Waste, and as required by the Tank Waste Remediation System Environmental Impact Statement Record of Decision and the Hanford Federal Facility Consent Agreement (Tn-Party Agreement), DOE plans to supplement the LAW treatment capacity of the WTP. Since 2002, DOE, in cooperation with the Environmental Protection Agency and State of Washington Department of Ecology has been evaluating technologies that could provide safe and effective supplemental treatment of LAW. Current efforts at Hanford are intended to provide additional information to aid a joint agency decision on which technology will be used to supplement the WTP. A Research, Development and Demonstration permit has been issued by the State of Washington to build and (for a limited time) operate a Demonstration Bulk Vitrification System (DBVS) facility to provide information for the decision on a supplemental treatment technology for up to 50% of the LAW. In the Bulk Vitrification (BV) process, LAW, soil, and glass-forming chemicals are mixed, dried, and placed in a refractory-lined box, Electric current, supplied through two graphite electrodes in the box, melts the waste feed, producing a durable glass waste-form. Although recent modifications to the process have resulted in significant improvements, there are continuing technical concerns.

  12. The bulking effect of dietary fiber in the rat large intestine: an in vivo study of cellulose, guar, pectin, wheat bran and oat bran

    E-Print Network [OSTI]

    Gazzaniga, Jeanne Marie

    1985-01-01T23:59:59.000Z

    THE BULKING EFFECT OF DIETARY FIBER IN THE RAT LARGE INTESTINE: AN IN VIVO STUDY OF CELLULOSE, GUAR, PECTIN, WHEAT BRAN AND OAT BRAN A Thesis by JEANNE MARIE GAZZANIGA Submitted to the Graduate College of Texas A&M University in partial... fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1985 Major Subject: Nutrition THE BULKING EFFECT OF DIETARY FIBER IN THE RAT LARGE INTESTINE: AN IN VIVO STUDY OF CELLULOSE, GUAR, PECTIN, WHEAT BRAN AND OAT BRAN A Thesis...

  13. Uniform-Format Solid Feedstock Supply System: A Commodity-Scale Design to Produce an Infrastructure-Compatible Bulk Solid from Lignocellulosic Biomass -- Executive Summary

    SciTech Connect (OSTI)

    J. Richard Hess; Christopher T. Wright; Kevin L. Kenney; Erin M. Searcy

    2009-04-01T23:59:59.000Z

    This report, Uniform-Format Solid Feedstock Supply System: A Commodity-Scale Design to Produce an Infrastructure-Compatible Bulk Solid from Lignocellulosic Biomass, prepared by Idaho National Laboratory (INL), acknowledges the need and provides supportive designs for an evolutionary progression from present day conventional bale-based supply systems to a uniform-format, bulk solid supply system that transitions incrementally as the industry launches and matures. These designs couple to and build from current state of technology and address science and engineering constraints that have been identified by rigorous sensitivity analyses as having the greatest impact on feedstock supply system efficiencies and costs.

  14. doi:10.1016/j.gca.2004.04.008 A preferred method for the determination of bulk compositions of coarse-grained

    E-Print Network [OSTI]

    Grossman, Lawrence

    -Al spinel. Because these phases are predicted to condense at high tem- peratures from a gas of solar nonrepresentative sampling of them in the laboratory. Many previous studies, especially those done by instrumental restricted portions of inclusions that happened to be exposed on surfaces of bulk meteorite samples. Here, we

  15. European Photovoltaic Solar Energy Conference, Valencia, Spain, 6-10 September 2010, 2DO.1.6 BULK LIFETIME ENHANCEMENT BY FIRING STEPS

    E-Print Network [OSTI]

    25th European Photovoltaic Solar Energy Conference, Valencia, Spain, 6-10 September 2010, 2DO.1.6 1 to getter metallic impurities and firing of silicon nitride (SiN) to induce hydrogen passivation. We analyse impurities and hydrogen bulk passivation, respectively. Additionally, the fired SiN layers have to ensure

  16. 2013 IREP Symposium-Bulk Power System Dynamics and Control -IX (IREP), August 25-30, 2013, Rethymnon, Greece Active network management: planning under

    E-Print Network [OSTI]

    Ernst, Damien

    ]. Such incentives have resulted in the on-going installation of wind and solar power generation resources2013 IREP Symposium-Bulk Power System Dynamics and Control -IX (IREP), August 25-30, 2013 In Europe, concern about the environmental impact of the electricity industry is currently driving

  17. COMPARISON OF THE CORROSION BEHAVIOR OF A BULK AMORPHOUS METAL, Zr41.2Ti13.8Cu12.5Ni10Be22.5,

    E-Print Network [OSTI]

    Ritchie, Robert

    COMPARISON OF THE CORROSION BEHAVIOR OF A BULK AMORPHOUS METAL, Zr41.2Ti13.8Cu12.5Ni10Be22 exhibit excellent corrosion resistance (4­7), which has been explained in terms of their structural researchers attribute "good corrosion resistance" to the entire class of amorphous metals. It is this point

  18. Unified Description of Bulk and Interface-Enhanced Spin Pumping S. M. Watts, J. Grollier,* C. H. van der Wal, and B. J. van Wees

    E-Print Network [OSTI]

    van der Wal, Caspar H.

    Unified Description of Bulk and Interface-Enhanced Spin Pumping S. M. Watts, J. Grollier,* C. H in semiconductors or metals by rf magnetic field pumping. With a semiclassical model we show that a rotating applied dynamics of a ferromagnetic electrode into or out of which the spin currents flow. In spin-pumping devices

  19. Analysis of the AlGaN/GaN vertical bulk current on Si, sapphire, and free-standing GaN substrates

    SciTech Connect (OSTI)

    Perez-Tomas, A.; Fontsere, A.; Llobet, J. [IMB-CNM-CSIC, Campus UAB, 08193 Bellaterra, Barcelona, CAT (Spain); Placidi, M. [IREC, Jardins Dones de Negre 1, 08930 Sant Adria de Besos, Barcelona (Spain); Rennesson, S.; Chenot, S.; Moreno, J. C.; Cordier, Y. [CRHEA-CNRS, Rue Bernard Gregory, Sophia Antipolis, 06560 Valbonne (France); Baron, N. [CRHEA-CNRS, Rue Bernard Gregory, Sophia Antipolis, 06560 Valbonne (France); PICOGIGA International, Pl M. Rebuffat, Courtaboeuf 7, 91140 Villejust (France)

    2013-05-07T23:59:59.000Z

    The vertical bulk (drain-bulk) current (I{sub db}) properties of analogous AlGaN/GaN hetero-structures molecular beam epitaxially grown on silicon, sapphire, and free-standing GaN (FS-GaN) have been evaluated in this paper. The experimental I{sub db} (25-300 Degree-Sign C) have been well reproduced with physical models based on a combination of Poole-Frenkel (trap assisted) and hopping (resistive) conduction mechanisms. The thermal activation energies (E{sub a}), the (soft or destructive) vertical breakdown voltage (V{sub B}), and the effect of inverting the drain-bulk polarity have also been comparatively investigated. GaN-on-FS-GaN appears to adhere to the resistive mechanism (E{sub a} = 0.35 eV at T = 25-300 Degree-Sign C; V{sub B} = 840 V), GaN-on-sapphire follows the trap assisted mechanism (E{sub a} = 2.5 eV at T > 265 Degree-Sign C; V{sub B} > 1100 V), and the GaN-on-Si is well reproduced with a combination of the two mechanisms (E{sub a} = 0.35 eV at T > 150 Degree-Sign C; V{sub B} = 420 V). Finally, the relationship between the vertical bulk current and the lateral AlGaN/GaN transistor leakage current is explored.

  20. Unique nature of the lowest Landau level in finite graphene samples with zigzag edges: Dirac electrons with mixed bulk-edge character

    E-Print Network [OSTI]

    Igor Romanovsky; Constantine Yannouleas; Uzi Landman

    2010-12-27T23:59:59.000Z

    Dirac electrons in finite graphene samples with zigzag edges under high magnetic fields (in the regime of Landau-level formation) are investigated with regard to their bulk-type and edge-type character. We employ tight-binding calculations on finite graphene flakes (with various shapes) to determine the sublattice components of the electron density in conjunction with analytic expressions (via the parabolic cylinder functions) of the relativistic-electron spinors that solve the continuous Dirac-Weyl equation for a semi-infinite graphene plane. Away from the sample edge, the higher Landau levels are found to comprise exclusively electrons of bulk-type character (for both sublattices); near the sample edge, these electrons are described by edge-type states similar to those familiar from the theory of the integer quantum Hall effect for nonrelativistic electrons. In contrast, the lowest (zero) Landau level contains relativistic Dirac electrons of a mixed bulk-edge character without an analog in the nonrelativistic case. It is shown that such mixed bulk-edge states maintain also in the case of a square flake with combined zigzag and armchair edges. Implications for the many-body correlated-electron behavior (relating to the fractional quantum Hall effect) in finite graphene samples are discussed.

  1. Bulk Power System Dynamics and Control -VII, August 19-24, 2007, Charleston, South Carolina, USA Dynamics of a Microgrid Supplied by Solid Oxide Fuel Cells1

    E-Print Network [OSTI]

    Hiskens, Ian A.

    . The results of an example in which two SOFC plants provide power to a microgrid are presented. The simulation1 Bulk Power System Dynamics and Control - VII, August 19-24, 2007, Charleston, South Carolina, USA, but is not concerned with the thermal dynamics. A DC-DC boost converter interfaces the SOFC stack to a DC bus, where

  2. Bulk Power System Dynamics and Control V, August 26-31, 2001, Onomichi, Japan Strong Resonance Effects in Normal Form Analysis

    E-Print Network [OSTI]

    Bulk Power System Dynamics and Control V, August 26-31, 2001, Onomichi, Japan Strong Resonance Engineering Department University of Wisconsin, Madison, WI 53706 USA dobson@engr.wisc.edu Abstract: Power resonance occurring in the power system linearization. Moreover, the changes in the coefficients when

  3. EFFECTS OF ION IRRADIATION ON Zr52.5Cu17.9Ni14.6Al10Ti5 (BAM-11) BULK METALLIC GLASS

    SciTech Connect (OSTI)

    Perez-Bergquist, Alex G [ORNL] [ORNL; Bei, Hongbin [ORNL] [ORNL; Leonard, Keith J [ORNL] [ORNL; Zhang, Yanwen [ORNL] [ORNL; Zinkle, Steven J [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    Bulk metallic glasses are intriguing candidates for nuclear applications due to their inherent amorphous structure, but their radiation response is largely unknown due to the relatively recent nature of innovations in bulk metallic glass fabrication. Here, microstructural and mechanical property evaluations have been performed on a Zr52.5Cu17.9Ni14.6Al10Ti5 bulk metallic glass (BAM-11) irradiated with 3 MeV Ni+ ions to 0.1 and 1.0 dpa at room temperature and 200 C. Nanoindentation hardness and Young s modulus both decreased by 6 to 20% in samples irradiated at room temperature, with the sample irradiated to 1.0 dpa experiencing the greatest change in mechanical properties. However, no significant changes in properties were observed in the samples irradiated at 200 C, and transmission electron microscopy showed no visible evidence of radiation damage or crystallization following ion irradiation at any of the tested conditions. These results suggest that BAM-11 bulk metallic glass may be useful for certain applications in nuclear environments.

  4. A method to predict the soil susceptibility to compaction of surface layers as a function of water content and bulk density

    E-Print Network [OSTI]

    Boyer, Edmond

    of the stress/strain relationship, as well as the mechanical parameters and their variation with different soil between soil mechanical properties and easily measurable soil properties as well as water content and bulk an important role in clayey and loamy soils. In contrast, for sandy soils, the mechanical parameters were less

  5. Lessons Learned from the Application of Bulk Characterization to Individual Containers on the Brookhaven Graphite Research Reactor Decommissioning Project at Brookhaven National Laboratory - 12056

    SciTech Connect (OSTI)

    Kneitel, Terri [US DOE, Brookhaven Site Office (United States); Rocco, Diane [Brookhaven National Laboratory (United States)

    2012-07-01T23:59:59.000Z

    When conducting environmental cleanup or decommissioning projects, characterization of the material to be removed is often performed when the material is in-situ. The actual demolition or excavation and removal of the material can result in individual containers that vary significantly from the original bulk characterization profile. This variance, if not detected, can result in individual containers exceeding Department of Transportation regulations or waste disposal site acceptance criteria. Bulk waste characterization processes were performed to initially characterize the Brookhaven Graphite Research Reactor (BGRR) graphite pile and this information was utilized to characterize all of the containers of graphite. When the last waste container was generated containing graphite dust from the bottom of the pile, but no solid graphite blocks, the material contents were significantly different in composition from the bulk waste characterization. This error resulted in exceedance of the disposal site waste acceptance criteria. Brookhaven Science Associates initiated an in-depth investigation to identify the root causes of this failure and to develop appropriate corrective actions. The lessons learned at BNL have applicability to other cleanup and demolition projects which characterize their wastes in bulk or in-situ and then extend that characterization to individual containers. (authors)

  6. Photopyroelectric deconvolution of bulk and surface optical-absorption and nonradiative energy conversion efficiency spectra in Ti:A1203 crystals

    E-Print Network [OSTI]

    Mandelis, Andreas

    - mental scheme to obtain high-resolution spectra of the optical-to-thermal energy conversion efficiency for quantitatively. When dealing with relatively highly absorbing condensed phases, bulk absorptions usually dominate conversion efficiency spectra in Ti:A1203 crystals J. Vanniasinkam, A. Mandelis, and S. Buddhudu Photothermal

  7. Design of Bulk Railway Terminals for the Shale Oil and Gas Industry C. Tyler Dick, P.E., M.ASCE and Lynn E. Brown2

    E-Print Network [OSTI]

    Barkan, Christopher P.L.

    Page 1 Design of Bulk Railway Terminals for the Shale Oil and Gas Industry C. Tyler Dick, P.E., M: Railway transportation is playing a key role in the development of many new shale oil and gas reserves in North America. In the rush to develop new shale oil and gas plays, sites for railway transload terminals

  8. Hybrid optics for the visible produced by bulk casting of sol-gel glass using diamond-turned molds

    SciTech Connect (OSTI)

    Bernacki, B.E.; Miller, A.C.; Maxey, L.C.; Cunningham, J.P. [Oak Ridge National Lab., TN (United States); Moreshead, W.V.; Nogues, J.L.R. [Geltech Inc., Alachua, FL (United States)

    1995-07-01T23:59:59.000Z

    Recent combinations of diffractive and refractive functions in the same optical component allow designers additional opportunities to make systems more compact and enhance performance. This paper describes a research program for fabricating hybrid refractive/diffractive components from diamond-turned molds using the bulk casting of sol-gel silica glass. The authors use the complementary dispersive nature of refractive and diffractive optics to render two-color correction in a single hybrid optical element. Since diamond turning has matured as a deterministic manufacturing technology, techniques previously suitable only in the infrared are now being applied to components used at visible wavelengths. Thus, the marriage of diamond turning and sol-gel processes offers a cost-effective method for producing highly customized and specialized optical components in high quality silica glass. With the sol-gel casting method of replication, diamond-turned mold costs can be shared over many pieces. Diamond turning takes advantage of all of the available degrees of freedom in a single hybrid optical element: aspheric surface to eliminate spherical aberration, kinoform surface for control of primary chromatic aberration, and the flexibility to place the kinoform on non-planar surfaces for maximum design flexibility. The authors discuss the critical issues involved in designing the hybrid element, single point diamond-turning the mold, and fabrication in glass using the sol-gel process.

  9. Strong light-matter coupling in bulk GaN-microcavities with double dielectric mirrors fabricated by two different methods

    SciTech Connect (OSTI)

    Reveret, F.; Disseix, P.; Vasson, A.; Leymarie, J. [Clermont Universite, Universite Blaise Pascal, LASMEA, BP 10448, F-63000 Clermont-Ferrand (France); CNRS, UMR 6602, LASMEA, F-63177 Aubiere (France); Bejtka, K. [CRHEA-CNRS, Rue Bernard Gregory, Parc Sophia Antipolis, 06560 Valbonne (France); Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Edwards, P. R.; Martin, R. W. [Department of Physics, SUPA, University of Strathclyde, Glasgow G4 0NG (United Kingdom); Chenot, S.; Sellers, I. R.; Duboz, J. Y.; Leroux, M.; Semond, F. [CRHEA-CNRS, Rue Bernard Gregory, Parc Sophia Antipolis, 06560 Valbonne (France)

    2010-08-15T23:59:59.000Z

    Two routes for the fabrication of bulk GaN microcavities embedded between two dielectric mirrors are described, and the optical properties of the microcavities thus obtained are compared. In both cases, the GaN active layer is grown by molecular beam epitaxy on (111) Si, allowing use of selective etching to remove the substrate. In the first case, a three period Al{sub 0.2}Ga{sub 0.8}N/AlN Bragg mirror followed by a {lambda}/2 GaN cavity are grown directly on the Si. In the second case, a crack-free 2 {mu}m thick GaN layer is grown, and progressively thinned to a final thickness of {lambda}. Both devices work in the strong coupling regime at low temperature, as evidenced by angle-dependent reflectivity or transmission experiments. However, strong light-matter coupling in emission at room temperature is observed only for the second one. This is related to the poor optoelectronic quality of the active layer of the first device, due to its growth only 250 nm above the Si substrate and its related high defect density. The reflectivity spectra of the microcavities are well accounted for by using transfer matrix calculations.

  10. Studies of Shear Band Velocity Using Spatially and Temporally Resolved Measurements of Strain During Quasistatic Compression of Bulk Metallic Glass

    SciTech Connect (OSTI)

    Wright, W J; Samale, M; Hufnagel, T; LeBlanc, M; Florando, J

    2009-06-15T23:59:59.000Z

    We have made measurements of the temporal and spatial features of the evolution of strain during the serrated flow of Pd{sub 40}Ni{sub 40}P{sub 20} bulk metallic glass tested under quasistatic, room temperature, uniaxial compression. Strain and load data were acquired at rates of up to 400 kHz using strain gages affixed to all four sides of the specimen and a piezoelectric load cell located near the specimen. Calculation of the displacement rate requires an assumption about the nature of the shear displacement. If one assumes that the entire shear plane displaces simultaneously, the displacement rate is approximately 0.002 m/s. If instead one assumes that the displacement occurs as a localized propagating front, the velocity of the front is approximately 2.8 m/s. In either case, the velocity is orders of magnitude less than the shear wave speed ({approx}2000 m/s). The significance of these measurements for estimates of heating in shear bands is discussed.

  11. Transport Properties of Bulk Thermoelectrics An International Round-Robin Study, Part I: Seebeck Coefficient and Electrical Resistivity

    SciTech Connect (OSTI)

    Wang, Hsin [ORNL; Porter, Wallace D [ORNL; Bottner, Harold [Fraunhofer-Institute, Freiburg, Germany; Konig, Jan [Fraunhofer-Institute, Freiburg, Germany; Chen, Lidong [Chinese Academy of Sciences; Bai, Shengqiang [Chinese Academy of Sciences; Tritt, Terry M. [Clemson University; Mayolett, Alex [Corning, Inc; Senawiratne, Jayantha [Corning, Inc; Smith, Charlene [Corning, Inc; Harris, Fred [ZT-Plus; Gilbert, Partricia [Marlow Industries, Inc; Sharp, Jeff [Marlow Industries, Inc; Lo, Jason [CANMET - Materials Technology Laboratory, Natural Resources of Canada; Keinke, Holger [University of Waterloo, Canada; Kiss, Laszlo I. [University of Quebec at Chicoutimi

    2013-01-01T23:59:59.000Z

    Recent research and development of high temperature thermoelectric materials has demonstrated great potential of converting automobile exhaust heat directly into electricity. Thermoelectrics based on classic bismuth telluride have also started to impact the automotive industry by enhancing air conditioning efficiency and integrated cabin climate control. In addition to engineering challenges of making reliable and efficient devices to withstand thermal and mechanical cycling, the remaining issues in thermoelectric power generation and refrigeration are mostly materials related. The figure-of-merit, ZT, still needs to improve from the current value of 1.0 - 1.5 to above 2 to be competitive to other alternative technologies. In the meantime, the thermoelectric community could greatly benefit from the development of international test standards, improved test methods and better characterization tools. Internationally, thermoelectrics have been recognized by many countries as an important area for improving energy efficiency. The International Energy Agency (IEA) group under the implementing agreement for Advanced Materials for Transportation (AMT) identified thermoelectric materials as an important area in 2009. This paper is Part I of the international round-robin testing of transport properties of bulk thermoelectrics. The main focuses in Part I are on two electronic transport properties: Seebeck coefficient and electrical resistivity.

  12. Markets to Facilitate Wind and Solar Energy Integration in the Bulk Power Supply: An IEA Task 25 Collaboration; Preprint

    SciTech Connect (OSTI)

    Milligan, M.; Holttinen, H.; Soder, L.; Clark, C.; Pineda, I.

    2012-09-01T23:59:59.000Z

    Wind and solar power will give rise to challenges in electricity markets regarding flexibility, capacity adequacy, and the participation of wind and solar generators to markets. Large amounts of wind power will have impacts on bulk power system markets and electricity prices. If the markets respond to increased wind power by increasing investments in low-capital, high-cost or marginal-cost power, the average price may remain in the same range. However, experiences so far from Denmark, Germany, Spain, and Ireland are such that the average market prices have decreased because of wind power. This reduction may result in additional revenue insufficiency, which may be corrected with a capacity market, yet capacity markets are difficult to design. However, the flexibility attributes of the capacity also need to be considered. Markets facilitating wind and solar integration will include possibilities for trading close to delivery (either by shorter gate closure times or intraday markets). Time steps chosen for markets can enable more flexibility to be assessed. Experience from 5- and 10-minute markets has been encouraging.

  13. Thermal Decomposition of Bulk K-CoMoSx Mixed Alcohol Catalyst Precursors and Effects on Catalyst Morphology and Performance

    SciTech Connect (OSTI)

    Menart, M. J.; Hensley, J. E.; Costelow, K. E.

    2012-09-26T23:59:59.000Z

    Cobalt molybdenum sulfide-type mixed alcohol catalysts were synthesized via calcination of precipitated bulk sulfides and studied with temperature programmed decomposition analysis. Precursors containing aqueous potassium were also considered. Precipitates thermally decomposed in unique events which released ammonia, carbon dioxide, and sulfur. Higher temperature treatments led to more crystalline and less active catalysts in general with ethanol productivity falling from 203 to 97 g (kg cat){sup -1} h{sup -1} when the calcination temperature was increased from 375 to 500 C. The addition of potassium to the precursor led to materials with crystalline potassium sulfides and good catalytic performance. In general, less potassium was required to promote alcohol selectivity when added before calcination. At calcination temperatures above 350 C, segregated cobalt sulfides were observed, suggesting that thermally decomposed sulfide precursors may contain a mixture of molybdenum and cobalt sulfides instead of a dispersed CoMoS type of material. When dimethyl disulfide was fed to the precursor during calcination, crystalline cobalt sulfides were not detected, suggesting an important role of free sulfur during decomposition.

  14. Two-moment Bulk Stratiform Cloud Microphysics in the Grid-point Atmospheric Model of IAP LASG (GAMIL)

    SciTech Connect (OSTI)

    Shi, Xiangjun; Wang, Bin; Liu, Xiaohong; Wang, Minghuai

    2013-05-01T23:59:59.000Z

    A two-moment bulk stratiform microphysics scheme, including recently developed physically-based droplet activation/ice nucleation parameterizations has been implemented into the Grid-point Atmospheric Model of IAP LASG (GAMIL) as an effort to enhance the model capability for studying aerosol indirect effects. Unlike the previous one-moment cloud microphysics scheme, the new scheme produces reasonable representation of cloud particle size and number concentration. This scheme captures the observed spatial variations in cloud droplet number concentrations. Simulated ice crystal number concentrations in cirrus clouds qualitatively agree with in-situ observations. The longwave and shortwave cloud forcing are in better agreement with observations. Sensitivity tests show that the column cloud droplet number concentrations calculated from two different droplet activation parameterizations are similar. However, ice crystal number concentration in mixed-phased clouds is sensitive to different heterogeneous freezing formulations. The simulation with high ice crystal number concentration in mixed-phase clouds has less liquid water path and weaker cloud forcing. Furthermore, ice crystal number concentration in cirrus clouds is sensitive to different ice nucleation parameterizations. Sensitivity tests also suggest that impact of pre-existing ice crystals on homogeneous freezing in old clouds should be taken into account.

  15. Study on effect of annealing conditions on structural, magnetic and superconducting properties of MgB{sub 2} bulk samples

    SciTech Connect (OSTI)

    Phaneendra, Konduru, E-mail: phaneendra-50@yahoo.com; Asokan, K., E-mail: phaneendra-50@yahoo.com; Kanjilal, D. [Inter University Accelerator Centre, Aruna Asaf Ali Marg, Vasanth Kung, New Delhi-110067 (India); Awana, V. P. S. [Quantum Phenomena and Applications, National Physical Laboratory, K S Krishnan Marg, New Delhi-110012 (India); Sastry, S. Sreehari [Dept. of Physics, Acharya Nagarjuna University, Guntur-522510 (India)

    2014-04-24T23:59:59.000Z

    Effect of annealing conditions on structural, magnetic and superconducting properties of Magnesium Diboride (MgB{sub 2}) bulk superconductor samples prepared by solid state route method are compared. The samples are made by taking Magnesium and Boron powders in stoichiometric ratio, grounded well and pelletized at pressure of about 10Tonnes. These pellets are annealed in both Argon and vacuum environment separately up to 800°c for two hours. Both the samples show clear superconducting transition at Tc ? 38 k. This is further conformed by AC/DC magnetization (M-T), Resistivity [? (T, H)] measurements under magnetic field up to 14 Tesla as well. Rietveld refinement of X-ray diffraction of both samples conformed the MgB{sub 2} phase formation with P6/mmm space group symmetry. Scanning Electron Microscopy images of the surface revile more agglomeration of grains in case of Argon annealed samples. This result in more critical current density (J{sub c}) of Argon annealed samples than vacuum annealed one calculated from Bean's critical state model. This high Jc is explained in terms of more inter grain connectivity for Argon annealed sample than vacuum annealed sample.

  16. Dynamics of Johari-Goldstein ? relaxation and its universal relation to ? relaxation in bulk metallic glasses by mechanical spectroscopy

    SciTech Connect (OSTI)

    Wu, Xuebang, E-mail: xbwu@issp.ac.cn; Guo, Lijun; Liu, C. S. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei, Anhui (China)

    2014-06-14T23:59:59.000Z

    The dynamics of the Johari–Goldstein (JG) ? relaxation and the ? relaxation in bulk metallic glasses (MGs) has been investigated by using mechanical spectroscopy combined with the Coupling Model. The ? relaxations of MGs exhibit different behaviors such as peaks, humps, and excess wings due to the different fluctuations of the chemical interactions among the constituting atoms. A universal correlation between the ? relaxation and the ? relaxation is generally found by their activation energies and relaxation times as well as the non-exponentiality parameter of the ? relaxation, which can be predicted quantitatively from the Coupling Model. Based on the quasi-point defects theory, a correlation factor ? shows a broad peak along with the ? relaxation, suggesting that the concentration and the correlation degree of the string-like configurations involved in the ? relaxation vary with increasing temperature, which challenges the previous view that the system is in an iso-configuration state below T{sub g} and may shed new light on the nature of the JG ? relaxation in metallic glasses.

  17. Time-resolved imaging of material response during laser-induced bulk damage in SiO2

    SciTech Connect (OSTI)

    Demos, S G; Negres, R A

    2008-10-24T23:59:59.000Z

    We report on time resolved imaging of the dynamic events taking place during laser-induced damage in the bulk of fused silica samples with nanosecond temporal resolution and one micron spatial resolution. These events include: shock/pressure wave formation and propagation, transient absorption, crack propagation and formation of residual stress fields. The work has been performed using a time-resolved microscope system that utilizes a probe pulse to acquire images at delay times covering the entire timeline of a damage event. Image information is enhanced using polarized illumination and simultaneously recording the two orthogonal polarization image components. For the case of fused silica, an electronic excitation is first observed accompanied by the onset of a pressure wave generation and propagation. Cracks are seen to form early in the process and reach their final size at about 25 ns into the damage event. In addition, changes that in part are attributed to transient absorption in the modified material are observed for delays up to about 200 microseconds.

  18. Benchmarking FENDL libraries through analysis of bulk shielding experiments on large SS316 assemblies for verification of ITER shielding characteristics

    SciTech Connect (OSTI)

    Youssef, M.Z.; Kumar, A.; Abdou, M.A. [Univ. of California, Los Angeles, CA (United States); Konno, Chikara; Maekawa, Fujio; Wada, Masayuki; Oyama, Yukio; Maekawa, Hiroshi; Ikeda, Yujiro [Japan Atomic Energy Research Inst., Ibaraki (Japan)

    1996-12-31T23:59:59.000Z

    FENDL-1 data base has been developed recently for use in ITER/EDA phase and other fusion-related design activities. It is now undergoing extensive testing and benchmarking using experimental data of differential and integral measured parameters obtained from fusion-oriented experiments. As part of co-operation between UCLA (U.S.) with JAERI (Japan) on executing the required neutronics R&D tasks for ITER shield design, two bulk shielding experiments on large SS316 assemblies were selected for benchmarking FENDL/MG-1 multigroup data base and FENDL/MC-1 continous energy data base. The analyses with the multigroup data (performed with S8, P5, DORT calculations with shielded and unshielded data) also included library derived from ENDF/B-VI data base for comparison purposes. The MCNP Monte Carlo code was used by JAERI with the FENDL/MC-1 data. The results of this benchmarking is reported in this paper along with the observed deficiencies and discrepancies. 20 refs., 27 figs., 1 tab.

  19. UV-Raman spectroscopy, X-ray photoelectron spectroscopy, and temperature programmed desorption studies of model and bulk heterogeneous catalysts

    SciTech Connect (OSTI)

    Tewell, Craig R.

    2002-08-19T23:59:59.000Z

    X-ray photoelectron spectroscopy (XPS) and Temperature Programmed Desorption (TPD) have been used to investigate the surface structure of model heterogeneous catalysts in ultra-high vacuum (UHV). UV-Raman spectroscopy has been used to probe the structure of bulk model catalysts in ambient and reaction conditions. The structural information obtained through UV-Raman spectroscopy has been correlated with both the UHV surface analysis and reaction results. The present day propylene and ethylene polymerization catalysts (Ziegler-Natta catalysts) are prepared by deposition of TiCl{sub 4} and a Al(Et){sub 3} co-catalyst on a microporous Mg-ethoxide support that is prepared from MgCl{sub 2} and ethanol. A model thin film catalyst is prepared by depositing metallic Mg on a Au foil in a UHV chamber in a background of TiCl{sub 4} in the gas phase. XPS results indicate that the Mg is completely oxidized to MgCl{sub 2} by TiCl{sub 4} resulting in a thin film of MgCl{sub 2}/TiCl{sub x}, where x = 2, 3, and 4. To prepare an active catalyst, the thin film of MgCl{sub 2}/TiCl{sub x} on Au foil is enclosed in a high pressure cell contained within the UHV chamber and exposed to {approx}1 Torr of Al(Et){sub 3}.

  20. Fiber Bulk Gaseous Carriers

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-UpHeat PumpRecordFederal Registry Comments May 4-9, 2007.FedwireAmorphous States

  1. www.MaterialsViews.com www.advenergymat.de

    E-Print Network [OSTI]

    Steckl, Andrew J.

    of the BHJ consists of an interpenetrating network of electron- donating conjugated polymers and elec- tron

  2. Edge and bulk components of lowest-Landau-level orbitals, correlated fractional quantum Hall effect incompressible states, and insulating behavior in finite graphene samples

    E-Print Network [OSTI]

    Constantine Yannouleas; Igor Romanovsky; Uzi Landman

    2010-09-13T23:59:59.000Z

    Many-body calculations of the total energy of interacting Dirac electrons in finite graphene samples exhibit joint occurrence of cusps at angular momenta corresponding to fractional fillings characteristic of formation of incompressible (gapped) correlated states (nu=1/3 in particular) and opening of an insulating energy gap (that increases with the magnetic field) at the Dirac point, in correspondence with experiments. Single-particle basis functions obeying the zigzag boundary condition at the sample edge are employed in exact diagonalization of the interelectron Coulomb interaction, showing, at all sizes, mixed equal-weight bulk and edge components. The consequent depletion of the bulk electron density attenuates the fractional-quantum-Hall-effect excitation energies and the edge charge accumulation results in a gap in the many-body spectrum.

  3. Responsiveness summary for the remedial investigation/feasibility study for management of the bulk wastes at the Weldon Spring quarry, Weldon Spring, Missouri

    SciTech Connect (OSTI)

    Peterson, J.M.; MacDonell, M.M.

    1990-08-01T23:59:59.000Z

    The US Department of Energy (DOE) is responsible for conducting remedial actions at the Weldon Spring site in St. Charles County, Missouri, under its Surplus Facilities Management Program. The site consists of a quarry and a chemical plant area located about 6.4 km (4 mi) northeast of the quarry. The quarry is surrounded by the Weldon Spring Wildfire Area and is near an alluvial well field that constitutes a major source of potable water for St. Charles County; the nearest supply well is located about 0.8 km (0.5 mi) southeast of the quarry. From 1942 to 1969, the quarry was used for the disposal of various radioactively and chemically contaminated materials. Bulk wastes in the quarry consist of contaminated soils and sediments, rubble, metal debris, and equipment. As part of overall site remediation, DOE is proposing to conduct an interim remedial action at the quarry to manage the radioactively and chemically contaminated bulk wastes contained therein. Potential remedial action alternatives for managing the quarry bulk wastes have been evaluated consistent with US Environmental Protection Agency (EPA) guidance for conducting remedial actions under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. The contents of these documents were developed in consultation with EPA Region VII and the state of Missouri and reflect the focused scope defined for this interim remedial action. 9 refs.

  4. CONVENE IGERT ConvEne IGERT Publications (updated March 1, 2013)

    E-Print Network [OSTI]

    Bigelow, Stephen

    ) 480­492 [doi] 43. A. D. Ostrowsk, B. F. Lin, M. V. Tirrell, and P. C. Ford, Liposome Encapsulation a Solution-Processed Small-Molecule Bulk Hetero- junction Solar Cell, Adv. Mater. 24 (2012) 2135­2141. [doi processable small molecule bulk heterojunction solar cells via solvent additives, RSC Adv. 2 (2012) 2232

  5. Simultaneous probing of bulk liquid phase and catalytic gas-liquid-solid interface under working conditions using attenuated total reflection infrared spectroscopy

    SciTech Connect (OSTI)

    Meemken, Fabian; Müller, Philipp; Hungerbühler, Konrad; Baiker, Alfons, E-mail: baiker@chem.ethz.ch [Department of Chemistry and Applied Biosciences, Institute for Chemical and Bioengineering, ETH Zürich, Hönggerberg, HCI, CH-8093 Zürich (Switzerland)

    2014-08-15T23:59:59.000Z

    Design and performance of a reactor set-up for attenuated total reflection infrared (ATR-IR) spectroscopy suitable for simultaneous reaction monitoring of bulk liquid and catalytic solid-liquid-gas interfaces under working conditions are presented. As advancement of in situ spectroscopy an operando methodology for gas-liquid-solid reaction monitoring was developed that simultaneously combines catalytic activity and molecular level detection at the catalytically active site of the same sample. Semi-batch reactor conditions are achieved with the analytical set-up by implementing the ATR-IR flow-through cell in a recycle reactor system and integrating a specifically designed gas feeding system coupled with a bubble trap. By the use of only one spectrometer the design of the new ATR-IR reactor cell allows for simultaneous detection of the bulk liquid and the catalytic interface during the working reaction. Holding two internal reflection elements (IRE) the sample compartments of the horizontally movable cell are consecutively flushed with reaction solution and pneumatically actuated, rapid switching of the cell (<1 s) enables to quasi simultaneously follow the heterogeneously catalysed reaction at the catalytic interface on a catalyst-coated IRE and in the bulk liquid on a blank IRE. For a complex heterogeneous reaction, the asymmetric hydrogenation of 2,2,2-trifluoroacetophenone on chirally modified Pt catalyst the elucidation of catalytic activity/enantioselectivity coupled with simultaneous monitoring of the catalytic solid-liquid-gas interface is shown. Both catalytic activity and enantioselectivity are strongly dependent on the experimental conditions. The opportunity to gain improved understanding by coupling measurements of catalytic performance and spectroscopic detection is presented. In addition, the applicability of modulation excitation spectroscopy and phase-sensitive detection are demonstrated.

  6. STRUCTURAL INTERACTIONS OF HYDROGEN WITH BULK AMORPHOUS MICROSTRUCTURES IN METALLIC SYSTEMS UNDERSTANDING THE ROLE OF PARTIAL CRYSTALLINITY ON PERMEATION AND EMBRITTLEMENT

    SciTech Connect (OSTI)

    Brinkman, Kyle; Fox, Elise; Korinko, Paul; Adams, Thad

    2010-05-10T23:59:59.000Z

    The development of metallic glasses in bulk form has led to a resurgence of interest into the utilization of these materials for a variety of applications. A potentially exciting application for these bulk metallic glass (BMG) materials is their use as composite membranes to replace high cost Pd/Pd-alloy membranes for enhanced gas separation processes. One of the major drawbacks to the industrial use of Pd/Pd-alloy membranes is that during cycling above and below a critical temperature an irreversible change takes place in the palladium lattice structure which can result in significant damage to the membrane. Furthermore, the cost associated with Pd-based membranes is a potential detractor for their continued use and BMG alloys offer a potentially attractive alternative. Several BMG alloys have been shown to possess high permeation rates, comparable to those measured for pure Pd metal. In addition, high strength and toughness when either in-situ or ex-situ second phase dispersoids are present. Both of these properties, high permeation and high strength/toughness, potentially make these materials attractive for gas separation membranes that could resist hydrogen 'embrittlement'. However, a fundamental understanding of the relationship between partially crystalline 'structure'/devitrification and permeation/embrittlement in these BMG materials is required in order to determine the operating window for separation membranes and provide additional input to the material synthesis community for improved alloy design. This project aims to fill the knowledge gap regarding the impact of crystallization on the permeation properties of metallic glass materials. The objectives of this study are to (i) determine the crystallization behavior in different gas environments of Fe and Zr based commercially available bulk metallic glass and (ii) quantify the effects of partial crystallinity on the hydrogen permeation properties of these metallic glass membranes.

  7. Looking for footprint of bulk metallic glass in electronic and phonon heat capacities of Cu{sub 55}Hf{sub 45?x}Ti{sub x} alloys

    SciTech Connect (OSTI)

    Remenyi, G. [Institut Néel, Université Grenoble Alpes, F-38042 Grenoble (France); CNRS, Institut Néel, F-38042 Grenoble (France); Biljakovi?, K. [CNRS, Institut Néel, F-38042 Grenoble (France); Institute of Physics, Bijeni?ka c. 46, P.O. Box 304, HR-10001 Zagreb (Croatia); Starešini?, D.; Dominko, D., E-mail: ddominko@ifs.hr [Institute of Physics, Bijeni?ka c. 46, P.O. Box 304, HR-10001 Zagreb (Croatia); Risti?, R. [Department of Physics, Trg Lj. Gaja 6, HR-31000 Osijek (Croatia); Babi?, E. [Department of Physics, Faculty of Science, Bijeni?ka c. 32, HR-10000 Zagreb (Croatia); Figueroa, I. A. [Institute for Materials Research-UNAM, Ciudad Universitaria Coyoacan, C.P. 04510 Mexico D.F. (Mexico); Davies, H. A. [Department of Engineering Materials, University of Sheffield, Sheffield S1 3JD (United Kingdom)

    2014-04-28T23:59:59.000Z

    We report on the heat capacity investigation of Cu{sub 55}Hf{sub 45?x}Ti{sub x} metallic glasses. The most appropriate procedure to estimate low temperature electronic and phonon contributions has been determined. Both contributions exhibit monotonous Ti concentration dependence, demonstrating that there is no relation of either the electron density of states at the Fermi level or the Debye temperature to the increased glass forming ability in the Ti concentration range x?=?15–30. The thermodynamic parameters (e.g., reduced glass temperature) remain better indicators in assessing the best composition for bulk metallic glass formation.

  8. Reliability of AlGaN/GaN high electron mobility transistors on low dislocation density bulk GaN substrate: Implications of surface step edges

    SciTech Connect (OSTI)

    Killat, N., E-mail: Nicole.Killat@bristol.ac.uk, E-mail: Martin.Kuball@bristol.ac.uk; Montes Bajo, M.; Kuball, M., E-mail: Nicole.Killat@bristol.ac.uk, E-mail: Martin.Kuball@bristol.ac.uk [Center for Device Thermography and Reliability (CDTR), H.H. Wills Physics Laboratory, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Paskova, T. [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States) [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States); Materials Science and Engineering Department, North Carolina State University, Raleigh, North Carolina 27695 (United States); Evans, K. R. [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States)] [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States); Leach, J. [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States) [Kyma Technologies, Inc., Raleigh, North Carolina 27617 (United States); Electrical and Computer Engineering Department, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Li, X.; Özgür, Ü.; Morkoç, H. [Electrical and Computer Engineering Department, Virginia Commonwealth University, Richmond, Virginia 23284 (United States)] [Electrical and Computer Engineering Department, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Chabak, K. D.; Crespo, A.; Gillespie, J. K.; Fitch, R.; Kossler, M.; Walker, D. E.; Trejo, M.; Via, G. D.; Blevins, J. D. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States)] [Air Force Research Laboratory, Wright-Patterson Air Force Base, Dayton, Ohio 45433 (United States)

    2013-11-04T23:59:59.000Z

    To enable gaining insight into degradation mechanisms of AlGaN/GaN high electron mobility transistors, devices grown on a low-dislocation-density bulk-GaN substrate were studied. Gate leakage current and electroluminescence (EL) monitoring revealed a progressive appearance of EL spots during off-state stress which signify the generation of gate current leakage paths. Atomic force microscopy evidenced the formation of semiconductor surface pits at the failure location, which corresponds to the interaction region of the gate contact edge and the edges of surface steps.

  9. Simultaneous assessment of phase chemistry, phase abundance and bulk chemistry with statistical electron probe micro-analyses: Application to cement clinkers

    SciTech Connect (OSTI)

    Wilson, William; Krakowiak, Konrad J.; Ulm, Franz-Josef, E-mail: ulm@mit.edu

    2014-01-15T23:59:59.000Z

    According to recent developments in cement clinker engineering, the optimization of chemical substitutions in the main clinker phases offers a promising approach to improve both reactivity and grindability of clinkers. Thus, monitoring the chemistry of the phases may become part of the quality control at the cement plants, along with the usual measurements of the abundance of the mineralogical phases (quantitative X-ray diffraction) and the bulk chemistry (X-ray fluorescence). This paper presents a new method to assess these three complementary quantities with a single experiment. The method is based on electron microprobe spot analyses, performed over a grid located on a representative surface of the sample and interpreted with advanced statistical tools. This paper describes the method and the experimental program performed on industrial clinkers to establish the accuracy in comparison to conventional methods. -- Highlights: •A new method of clinker characterization •Combination of electron probe technique with cluster analysis •Simultaneous assessment of phase abundance, composition and bulk chemistry •Experimental validation performed on industrial clinkers.

  10. Self-Gravitational Corrections to the Cardy-Verlinde Formula and the FRW Brane Cosmology in SdS_5 Bulk

    E-Print Network [OSTI]

    Mohammad R. Setare; Elias C. Vagenas

    2004-05-30T23:59:59.000Z

    The semiclassical corrections to the Cardy-Verlinde entropy of a five-dimensional Schwarzschild de-Sitter black hole (SdS_5) are explicitly evaluated. These corrections are considered within the context of KKW analysis and arise as a result of the self-gravitation effect. In addition, a four-dimensional spacelike brane is considered as the boundary of the SdS_5 bulk background. It is already known that the induced geometry of the brane is exactly given by that of a radiation-dominated FRW universe. By exploiting the CFT/FRW-cosmology relation, we derive the self-gravitational corrections to the first Friedmann-like equation which is the equation of the brane motion. The additional term that arises due to the semiclassical analysis can be viewed as stiff matter where the self-gravitational corrections act as the source for it. This result is contrary to standard analysis that regards the charge of SdS_5 bulk black hole as the source for stiff matter. Furthermore, we rewrite the Friedmann-like equation in a such way that it represents the conservation equation of energy of a point particle moving in a one-dimensional effective potential. The self-gravitational corrections to the effective potential and, consequently, to the point particle's motion are obtained. A short analysis on the asymptotic behavior of the 4-dimensional brane is presented.

  11. Effective field theory for the bulk-edge correspondence in a two-dimensional Z_2 topological insulator with Rashba interactions

    E-Print Network [OSTI]

    Pedro R. S. Gomes; Po-Hao Huang; Claudio Chamon; Christopher Mudry

    2014-09-29T23:59:59.000Z

    We determine the effective field theory in (2+1)-dimensional space and time that captures the long wave length and low-energy limit of fermions hopping on a honeycomb lattice at half-filling when both a dominant intrinsic and subdominant Rashba spin-orbit couplings are present. This effective field theory for a Z_2 topological insulator (the Kane-Mele model at vanishing uniform and staggered chemical potentials) is a perturbation around a double Chern-Simons theory, with the U(1) gauge invariance associated to spin conservation explicitly broken due to the Rashba spin orbit coupling. Nonetheless, we find that the effective field theory has a BRST symmetry that allows us to construct the bulk-edge correspondence.

  12. Experimental evidence of V{sub O}?Zn{sub i} complex to be intrinsic donor in bulk ZnO

    SciTech Connect (OSTI)

    Asghar, M.; Mahmood, K. [Department of Physics, The Islamia University of Bahawalpur 63100 (Pakistan); Hasan, M.-A; Tsu, R.; Ferguson, I. T. [Department of Electrical and Computer Engineering, University of North Carolina Charlotte, NC 28223 (United States)

    2014-02-21T23:59:59.000Z

    Theoretical evidence of V{sub O}?Zn{sub i} to be a native donor in bulk ZnO has been under debate. To resolve the issue, we annealed several pieces of as grown zinc rich n-type ZnO thin film having N{sub D} ? 3.26 × 10{sup 17} cm{sup ?3} grown by molecular beam epitaxy on Si (001) substrate in oxygen environment at 500°C – 800°C, keeping a step of 100°C for one hour, each. Room temperature Hall measurements demonstrated that free donor concentration decreased exponentially and Arrhenius plot yielded activation energy to be 1.2±0.02 eV. This value is in an agreement with the theoretically reported activation energy of V{sub O}?Zn{sub i} donor complex in ZnO.

  13. Bulk liquid membrane for the recovery of chromium(VI) from a hydrochloric acid medium using dicyclohexano-18-crown-6 as extractant-carrier

    SciTech Connect (OSTI)

    Zouhri, A. [Univ. Ibnou Zohr, Agadir (Morocco). Faulte de Sciences] [Univ. Ibnou Zohr, Agadir (Morocco). Faulte de Sciences; Ernst, B.; Burgard, M. [Ecole Europeenne de Chimie, Polymeres et Materiaux, Strasbourg (France)] [Ecole Europeenne de Chimie, Polymeres et Materiaux, Strasbourg (France)

    1999-06-01T23:59:59.000Z

    The solvent extraction and transfer of chromic acid from hydrochloric acid medium through a bulk liquid membrane containing dicyclohexano-18-crown-6 (L) were studied. Extraction experiments pointed out that chromium(VI) was coextracted with the chloride ion which formed the complex ion pair L(H{sub 3}O{sup +})CrO{sub 3}Cl{sup {minus}} in the organic phase. The Donnan equilibrium isotherm based on the extraction, stripping, and CrO{sub 3}Cl{sup {minus}} hydrolysis equilibria allowed prediction of the performance of the semipermeable membrane to concentrate chlorochromic acid in the receiving phase. Transport experiments confirmed the ability of the liquid membrane to recover chlorochromic acid in pure water. The transport kinetics was modeled by using the two-film theory applied to the liquid membrane.

  14. Spectra of optical parameters in bulk and film amorphous alloys of the Se{sub 95}As{sub 5} system containing samarium (Sm) impurities

    SciTech Connect (OSTI)

    Djalilov, N. Z.; Damirov, G. M., E-mail: gafil@physics.ab.az [National Academy of Sciences of Azerbaijan, Institute of Physics (Azerbaijan)

    2011-09-15T23:59:59.000Z

    Reflectance spectra of bulk and film amorphous alloys of the Se{sub 95}As{sub 5} system containing samarium (Sm) impurities are studied in the energy range of 1-6 eV. Spectral dependences of optical constants and derivatives of optical dielectric functions are calculated by the Kramers-Kronig method. Changes in spectra of optical parameters depending on the content of impurities introduced into Se{sub 95}As{sub 5} and conditions of their preparation are explained based on the cluster model. According to the latter, changes in the electron density of states depends on changes in atomic configurations in clusters, i.e., short-range order changes.

  15. Cascaded second-harmonic generation, summation of the wave vectors of the bulk defect-deformation waves, and generation of multimode micro- and nanostructures by laser irradiation of solids

    SciTech Connect (OSTI)

    Emel'yanov, Vladimir I [Lomonosov Moscow State University, Faculty of Physics, Moscow (Russian Federation)

    2011-02-28T23:59:59.000Z

    We consider for the first time three-wave interactions of bulk quasi-static defect-deformation (DD) waves (generation of the second DD harmonic and summation of the wave vectors), similar to three-wave interactions in nonlinear optics and acoustics, leading to cascaded broadening of the spectrum of spatial DD harmonics. Based on the theory developed, we interpret the recently observed effect of laser-induced generation of the bulk periodic structure of silver nanoparticles with a discrete spatial spectrum, extending from micro- to nanometres. (nonlinear optical phenomena)

  16. Use of Sm-123 + Sm-211 Mixed-powder Buffers to Assist the Growth of SmBCO and ZrO2-doped SmBCO Single Grain, Bulk Superconductors

    E-Print Network [OSTI]

    Zhao, Wen; Shi, Yunhua; Dennis, Anthony R.; Cardwell, David A.

    2014-12-18T23:59:59.000Z

    . Murakami, and I. Hirabayashi, "High critical current density in RE–Ba–Cu–O bulk superconductors with very fine RE2BaCuO5 particles," Physica C: Superconductivity, vol. 412-414, no. 1, pp. 557–565, Oct. 2004. [4] H. S. Chauhan, and M. Murakami, "Hot... )–Ba–Cu–O superconductors," Nature Materials, vol. 4, pp. 476 - 480, Jun. 2005. [7] N. H. Babu, K. Iida, Y. Shi, and D. A. Cardwell, "Processing of high performance (LRE)-Ba–Cu–O large, single-grain bulk superconductors in air," Physica C: Superconductivity, vol. 445...

  17. 2013 IREP Symposium-Bulk Power System Dynamics and Control IX (IREP), August 25-30, 2013, Rethymnon, Greece A Production Simulation Tool for Systems with an Integrated Concentrated Solar

    E-Print Network [OSTI]

    Gross, George

    , Rethymnon, Greece A Production Simulation Tool for Systems with an Integrated Concentrated Solar Plant2013 IREP Symposium-Bulk Power System Dynamics and Control ­IX (IREP), August 25-30, 2013 with Thermal Energy Storage Ti Xu George Gross University of Illinois at Urbana-Champaign University

  18. Radiological consequences of ship collisions that might occur in U.S. Ports during the shipment of foreign research reactor spent nuclear fuel to the United States in break-bulk freighters

    SciTech Connect (OSTI)

    Sprung, J.L.; Bespalko, S.J.; Massey, C.D.; Yoshimura, R. [Sandia National Laboratory, Albuquerque, NM (United States); Johnson, J.D. [GRAM Inc., Albuquerque, NM (United States); Reardon, P.C. [PCRT Technologies, Albuquerque, NM (United States); Ebert, M.W.; Gallagher D.W. [Science Applications International Corp., Reston, VA (United States)

    1996-08-01T23:59:59.000Z

    Accident source terms, source term probabilities, consequences, and risks are developed for ship collisions that might occur in U.S. ports during the shipment of spent fuel from foreign research reactors to the United States in break-bulk freighters.

  19. Bulk Power System Dynamics and Control VIII, August 1-6, 2010, Buzios, Rio de Janeiro, Brazil Impact of Delays on a Consensus-based Primary Frequency Control Scheme

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    by a Multi-Terminal HVDC Grid Jing Dai, Yannick Phulpin Sup´elec, France {jing.dai, yannick systems connected by a multi-terminal HVDC grid. We focus on a control scheme that mod- ifies the power current (HVDC) systems for bulk power transmission over long distances [3] and underground cable cross

  20. Hanford ETR Bulk Vitrification System - Demonstration Bulk Vitrification

    Broader source: Energy.gov (indexed) [DOE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists'Montana.ProgramJulietip sheetK-4In 2013 many autoThis road mapF Reactor