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.; 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.

  5. 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.

  6. 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.

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

    E-Print Network [OSTI]

    Alam, Muhammad A.

    MORPHOLOGY DEPENDENT SHORT CIRCUIT CURRENT IN BULK HETEROJUNCTION SOLAR CELL Biswajit Ray, Pradeep, West Lafayette, Indiana, USA ABSTRACT Polymer based bulk heterostructure (BH) solar cell offers a relatively inexpensive option for the future solar cell technology, provided its efficiency increases beyond

  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. Thermal annealing study on P3HT: PCBM based bulk heterojunction organic solar cells using impedance spectroscopy

    SciTech Connect (OSTI)

    Gollu, Sankara Rao, E-mail: sankar.gollu@gmail.com [Plastic Electronics and Energy Lab (PEEL), Department of Metallurgical Engineering and Material Science, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India); Sharma, Ramakant, E-mail: diptig@iitb.ac.in; G, Srinivas, E-mail: diptig@iitb.ac.in; Gupta, Dipti, E-mail: diptig@iitb.ac.in [Plastic Electronics and Energy Lab (PEEL) Department of Metallurgical Engineering and Material Science, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India)

    2014-10-15T23:59:59.000Z

    Recently, Thermal annealing is an important process for bulk heterojunction organic solar cells (BHJ OSCs) to improve the device efficiency and performance of the organic solar cells. Here in, we have examined the changes in the efficiency and morphology of P3HT: PCBM film according to the thermal annealing temperature to find the changes during the annealing process by measuring the optical absorption, atomic force microscope and X-ray diffraction. We also investigated the effect of different annealing process conditions (without, pre- and post-annealing) on the device performance of the inverted bulk heterojunction organic solar cells consist the structure of ITO/ ZnO / P3HT: PCBM / MoO{sub 3}/ Al by measuring AC impedance characteristics. Particularly, the power conversion efficiency (PCE), crystalline nature of the polymer, light absorption and the surface smoothness of P3HT: PCBM films are significantly improved after the annealing process. These results indicated the improvement in terms of PCE, interface smoothness between the P3HT: PCBM and MoO{sub 3} layers of the post annealed device originated from the decrease of series resistance between P3HT: PCBM layer and Al electrodes, which could be due to decrease in the effective life time of charge carriers.

  10. 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.

  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. "Plastic" Solar Cells: Self-Assembly of Bulk HeterojunctionNano...

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

    "Plastic" Solar Cells: Self-Assembly of Bulk Heterojunction Nano-Materials by Spontaneous Phase Separation October 20, 2009 at 3pm36-428 Alan Heeger Department of Chemistry,...

  13. A compact physical model for morphology induced intrinsic degradation of organic bulk heterojunction solar cell

    E-Print Network [OSTI]

    Alam, Muhammad A.

    for an intrinsic degradation concern for bulk heterojunction type organic photovoltaic (BH-OPV) cells that involveA compact physical model for morphology induced intrinsic degradation of organic bulk-induced degradation in Si-based cell (Staebler-Wronski effect), Cu diffusion in thin film (copper indium gallium

  14. Device Characteristics of Bulk-Heterojunction Polymer Solar Cells (DMR-0819860)

    E-Print Network [OSTI]

    Petta, Jason

    Device Characteristics of Bulk-Heterojunction Polymer Solar Cells (DMR-0819860) H. Wang, E. Gomez University Polymer solar cells are important candidates for sustainable, low-cost energy generation of vertical compositional heterogeneities on charge transport in polymer solar cells via modular construction

  15. 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

  16. A C70-carbon nanotube complex for bulk heterojunction photovoltaic cells

    SciTech Connect (OSTI)

    Lau, Xinbo C.; Wang, Zhiqian; Mitra, Somenath, E-mail: Somenath.Mitra@njit.edu [Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States)] [Department of Chemistry and Environmental Science, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States)

    2013-12-09T23:59:59.000Z

    A C70 fullerene-multi-walled carbon nanotube (C70-CNT) complex has been used as a component of the photoactive layer in a bulk heterojunction photovoltaic cell. As compared to a control device with only C70, the addition of CNTs led to improvements in short circuit current density (J{sub sc}), open circuit voltage (V{sub oc}), and power conversion efficiency by 31.8, 17.5, and 69.5%, respectively. This device takes advantage of both the electron accepting feature of C70 and the high electron transport capability of CNTs. These results indicate that C70 decorated CNT is a promising additive for performance enhancement of polymer photovoltaic cells.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  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. 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.

  4. 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.

  5. 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.

  6. Organic bulk heterojunction solar cells using poly,,2,5-bis,,3-tetradecyllthiophen-2-yl...thieno3,2,-bthiophene...

    E-Print Network [OSTI]

    McGehee, Michael

    . While the cost per watt of solar cell technology has steadily decreased in the past decade, an estimated the cost is to make solar cells with low-cost organic materials that can be processed from solutionOrganic bulk heterojunction solar cells using poly,,2,5-bis,,3-tetradecyllthiophen-2-yl...thieno3

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

    E-Print Network [OSTI]

    Rochefort, Alain

    ­5]. However, the power conversion efficiency of organic photovoltaic cells has to reach a minimal 10% target [10­12]. Therefore, before attaining the 10% target with high-efficiency BHJ organic photovoltaic) molecule is more often used in high-efficiency organic photovoltaic cells [4]. Nevertheless, one may assume

  8. 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.

  9. Factors influencing photocurrent generation in organic bulk heterojunc...

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

    Factors influencing photocurrent generation in organic bulk heterojunction solar cells: interfacial energetics and blend microstructure April 29, 2009 at 3pm36-428 Jenny Nelson...

  10. 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.

  11. Heterojunction solar cell

    DOE Patents [OSTI]

    Olson, Jerry M. (Lakewood, CO)

    1994-01-01T23:59:59.000Z

    A high-efficiency single 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. The conversion effiency 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.

  12. 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.

  13. Improving the Performance of P3HT-Fullerene Solar Cells with Side-Chain-Functionalized Poly(thiophene) Additives: A New Paradigm for Polymer Design

    E-Print Network [OSTI]

    Lobez, Jose M.

    The motivation of this study is to determine if small amounts of designer additives placed at the polymer–fullerene interface in bulk heterojunction (BHJ) solar cells can influence their performance. A series of AB-alternating ...

  14. 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. ...

  15. 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

  16. 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

  17. Nano-Confinement Induced Chain Alignment in Ordered P3HT

    E-Print Network [OSTI]

    Hu, Wenchuang "Walter"

    as cost- effective functional materials for organic electronic devices such as solar cells1,2 and field as well. For example, in bulk heterojunction (BHJ) solar cell structures, control of nanomor- phology and favorably. In BHJ solar cells, the hole mobility is just on the order of 10 4 cm2 /V · s, which

  18. 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.

  19. 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.

  20. Center for Quantum Science and Engineering Weekly Seminar

    E-Print Network [OSTI]

    Wu, Yih-Min

    , 14:30 ~ 15:30 TITLE Probe Nanoscale Morphologies of Bulk Heterojunction Polymer Solar Cell from cells are promising renewable energy sources because of their low production cost, high mechanical Sinica PLACE Rm716, CCMS & New Physics Building, NTU Abstract Bulk heterojunction (BHJ) polymer solar

  1. 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

  2. Factors influencing photocurrent generation in organic bulk heterojunction

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC) Environmental Assessments (EA)Budget » FY 2014FacilitiesSheet 300Office of

  3. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del SolStrengthening a solidSynthesis of 2DandEnergy The Year onnanocrystals

  4. 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.

  5. 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"...

  6. Universality of non-Ohmic shunt leakage in thin-film solar cells S. Dongaonkar,1,a

    E-Print Network [OSTI]

    Alam, Muhammad A.

    Universality of non-Ohmic shunt leakage in thin-film solar cells S. Dongaonkar,1,a J. D. Servaites thin-film solar cell types: hydrogenated amorphous silicon a-Si:H p-i-n cells, organic bulk heterojunction BHJ cells, and Cu In,Ga Se2 CIGS cells. All three device types exhibit a significant shunt leakage

  7. 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.

  8. 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.

  9. 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

  10. Nanofluidic Diodes Based on Nanotube Heterojunctions

    E-Print Network [OSTI]

    Yang, Peidong

    Nanofluidic Diodes Based on Nanotube Heterojunctions Ruoxue Yan, Wenjie Liang, Rong Fan devices has recently been implemented into the nanofluidic field for the active control of ion transport, a signature of ionic diode behavior. Such nanofluidic diodes could find applications in ion separation

  11. Supporting Information Nanofluidic Diodes based on Nanotube Heterojunctions

    E-Print Network [OSTI]

    Yang, Peidong

    Supporting Information Nanofluidic Diodes based on Nanotube Heterojunctions Ruoxue Yan, Wenjie loaded with R6G. Nanotube diode device fabrication Nanofluidic diode devices interfaced

  12. Semiconductor heterojunction band offsets and charge neutrality

    E-Print Network [OSTI]

    Lee, Chomsik

    1989-01-01T23:59:59.000Z

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

  13. Indium oxide/n-silicon heterojunction solar cells

    DOE Patents [OSTI]

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

    1982-12-28T23:59:59.000Z

    A high photo-conversion efficiency indium oxide/n-silicon heterojunction solar cell is spray deposited from a solution containing indium trichloride. The solar cell exhibits an Air Mass One solar conversion efficiency in excess of about 10%.

  14. 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.

  15. Scaling of SiGe Heterojunction Bipolar Transistors

    E-Print Network [OSTI]

    Rieh, Jae-Sung

    Scaling of SiGe Heterojunction Bipolar Transistors JAE-SUNG RIEH, SENIOR MEMBER, IEEE, DAVID-century. This paper inves- tigates the impacts of scaling on SiGe heterojunction bipolar tran- sistors (HBTs), which), epitaxial-base Si BJTs (Epi Si BJT), SiGe HBTs (SiGe HBT), and SiGe HBTs with carbon-doped base (SiGeC HBT

  16. Hole-blocking titanium-oxide/silicon heterojunction and its application to photovoltaics

    E-Print Network [OSTI]

    Hole-blocking titanium-oxide/silicon heterojunction and its application to photovoltaics Sushobhan-bandgap semiconducting heterojunctions on silicon. Here, we present a wide-bandgap heterojunction--between titanium oxide and crystalline silicon--where the titanium oxide is deposited via a metal-organic chemical vapor deposition

  17. 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

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

    E-Print Network [OSTI]

    Iza, Diana C; Muñoz-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...

  19. 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...

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. Controlled Assembly of Hybrid Bulk-Heterojunction Solar Cells by Sequential Deposition

    E-Print Network [OSTI]

    Gur, Ilan; Fromer, Neil A.; Alivisatos, A. Paul

    2006-01-01T23:59:59.000Z

    C. ; Whiting, G. L. ; Alivisatos, A. P. Advanced FunctionalU. ; Dittmer, J. J. ; Alivisatos, A. P. Science 2002, 295,Milliron, D. J. ; Gur, I. ; Alivisatos, A. P. Mrs Bulletin

  5. 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

  6. 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.

  7. 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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol HomeFacebookScholarship Fund3Biology| Nationalof big-dataInvestigation

  8. "Plastic" Solar Cells: Self-Assembly of Bulk Heterojunction

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch >Internship ProgramBiomass andTriangleNameANDProfessorDecember

  9. 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.

  10. 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

  11. 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.

  12. Buffer transport mechanisms in intentionally carbon doped GaN heterojunction field effect transistors

    SciTech Connect (OSTI)

    Uren, Michael J.; Cäsar, Markus; Kuball, Martin [Center for Device Thermography and Reliability, H.H. Wills Physics Laboratory, University of Bristol, Bristol BS8 1TL (United Kingdom); Gajda, Mark A. [NXP Semiconductors, Bramhall Moor Lane, Hazel Grove, Stockport SK7 5BJ (United Kingdom)

    2014-06-30T23:59:59.000Z

    Temperature dependent pulsed and ramped substrate bias measurements are used to develop a detailed understanding of the vertical carrier transport in the buffer layers in a carbon doped GaN power heterojunction field effect transistor. Carbon doped GaN and multiple layers of AlGaN alloy are used in these devices to deliver an insulating and strain relieved buffer with high breakdown voltage capability. However, understanding of the detailed physical mechanism for its operation is still lacking. At the lowest electric fields (<10 MV/m), charge redistribution within the C doped layer is shown to occur by hole conduction in the valence band with activation energy 0.86?eV. At higher fields, leakage between the two-dimensional electron gas and the buffer dominates occurring by a Poole-Frenkel mechanism with activation energy ?0.65?eV, presumably along threading dislocations. At higher fields still, the strain relief buffer starts to conduct by a field dependent process. Balancing the onset of these leakage mechanisms is essential to allow the build-up of positive rather than negative space charge, and thus minimize bulk-related current-collapse in these devices.

  13. Evaluation of the Radiation Tolerance of Several Generations of SiGe Heterojunction

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    1 Evaluation of the Radiation Tolerance of Several Generations of SiGe Heterojunction Bipolar. The devices investigated were first, second and third-generation Silicon- Germanium (SiGe) Heterojunction-engineered SiGe technology [1] have potential advantages when compared with Complementary Metal Oxide

  14. Cross-sectional Scanning Tunneling Microscopy and Spectroscopy of InGaP/GaAs Heterojunctions

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Cross-sectional Scanning Tunneling Microscopy and Spectroscopy of InGaP/GaAs Heterojunctions Y Abstract Compositionally abrupt InGaP/GaAs heterojunctions grown by gas-source molecular beam epitaxy have the InGaP layer show non-uniform In and Ga distribution. About 1.5 nm of transition region

  15. 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...

  16. GaN/Cu[subscript 2]O Heterojunctions for Photovoltaic Applications

    E-Print Network [OSTI]

    Hering, K.P.

    Several growth methods were employed to investigate the photovoltaic behavior of GaN/Cu[subscript 2]O heterojunctions by depositing cuprous oxide thin films on top of gallium nitride templates. The templates consist of a ...

  17. 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

    width dependent study of Solar Cell parameters Mott-SchotkyCore/Shell NW based solar cells and NIR photodetectors. Thep-n heterojunction NW solar cells and detailed study of the

  18. 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.

  19. Method for forming indium oxide/n-silicon heterojunction solar cells

    DOE Patents [OSTI]

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

    1984-03-13T23:59:59.000Z

    A high photo-conversion efficiency indium oxide/n-silicon heterojunction solar cell is spray deposited from a solution containing indium trichloride. The solar cell exhibits an Air Mass One solar conversion efficiency in excess of about 10%.

  20. InAs=InGaP=GaAs heterojunction power Schottky rectifiers

    E-Print Network [OSTI]

    Woodall, Jerry M.

    InAs=InGaP=GaAs heterojunction power Schottky rectifiers A. Chen, M. Young and J.M. Woodall A low-matched InGaP on GaAs, to make a high-temperature power rectifier. The LT molecular beam epitaxy technique enables the formation of an abrupt interface between InAs and InGaP. This heterojunction rectifier

  1. GaN/AlGaN heterojunction infrared detector responding in 814 and 2070 m ranges

    E-Print Network [OSTI]

    Perera, A. G. Unil

    GaN/AlGaN heterojunction infrared detector responding in 8­14 and 20­70 m ranges G. Ariyawansa, M October 2006 A GaN/AlGaN heterojunction interfacial work function internal photoemission infrared detector, the work demonstrates 54 m 5.5 THz operation of the detector based on 1s­2p± transition of Si donors in GaN

  2. Influence of Substrate on Crystallization in Polythiophene/fullerene Blends

    SciTech Connect (OSTI)

    C He; D Germack; J Kline; D Delongchamp; D Fischer; C Snyder; M Toney; J Kushmerick; L Richter

    2011-12-31T23:59:59.000Z

    The nanoscale morphology of the active layer in organic, bulk heterojunction (BHJ) solar cells is crucial to device performance. Often a combination of casting conditions and post deposition thermal treatment is used to optimize the morphology. In general, the development of microscopic crystals is deleterious, as the exciton diffusion length is {approx}10 nm. We find that the microscopic crystallization behavior in polythiophene/fullerene blends is strongly influenced by the substrate on which the BHJ is cast. With a silicon oxide substrate, the crystal nucleation density is high and significant crystallization occurs at a temperature of 140 C. On more hydrophobic substrates, significantly higher temperatures are required for observable crystallization. This difference is attributed to the interfacial segregation of the PCBM, controlled by the substrate surface energy. The substrate dependence of crystallization has significant implications on the fullerene crystal growth mechanisms and practical implications for device studies.

  3. Band offsets at heterojunctions and the charge neutrality condition

    E-Print Network [OSTI]

    Taferner, Waltraud Teresa

    1990-01-01T23:59:59.000Z

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

  4. CsBr/GaN Heterojunction Photoelectron Source

    SciTech Connect (OSTI)

    Maldonado, J.R.; /Stanford U., Elect. Eng. Dept.; Liu, Z.; Sun, Y.; /SLAC, SSRL; Schuetter, S.; /Wisconsin U., Madison; Pianetta, P.; /SLAC, SSRL; Pease, R.F.W.; /Stanford U., Elect. Eng. Dept.

    2009-04-30T23:59:59.000Z

    Experimental results on a new CsBr/GaN heterojunction photocathode structure are presented. The results indicate a fourfold improvement in photoyield relative to CsBr/Cr photocathodes. A model is presented based on intraband states in CsBr and electron injection from the GaN (with 1% addition of indium) substrate to explain the observed photoyield enhancement. The photocathode lifetime at high current density (>40 A/cm{sup 2}) is limited by laser heating of the small illuminated area. Calculations are presented for sapphire and diamond substrates, indicating a factor of 20 reduction in temperature for the latter. The results are encouraging for the realization of a high photoyield photocathode operating at high current density with long lifetime.

  5. 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.

  6. Effect of simultaneous electrical and thermal treatment on the performance of bulk heterojunction organic solar cell blended with organic salt

    SciTech Connect (OSTI)

    Sabri, Nasehah Syamin; Yap, Chi Chin; Yahaya, Muhammad [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia); Salleh, Muhamad Mat [Institute of Microengineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor (Malaysia)

    2013-11-27T23:59:59.000Z

    This work presents the influence of simultaneous electrical and thermal treatment on the performance of organic solar cell blended with organic salt. The organic solar cells were composed of indium tin oxide as anode, poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene]: (6,6)-phenyl-C61 butyric acid methyl ester: tetrabutylammonium hexafluorophosphate blend as organic active layer and aluminium as cathode. The devices underwent a simultaneous fixed-voltage electrical and thermal treatment at different temperatures of 25, 50 and 75 °C. It was found that photovoltaic performance improved with the thermal treatment temperature. Accumulation of more organic salt ions in the active layer leads to broadening of p-n doped regions and hence higher built-in electric field across thin intrinsic layer. The simultaneous electrical and thermal treatment has been shown to be able to reduce the electrical treatment voltage.

  7. Annealing effects on the photovoltaic performance of all-conjugated poly(3-alkylthiophene) diblock copolymer-based bulk heterojunction solar

    E-Print Network [OSTI]

    Lin, Zhiqun

    Annealing effects on the photovoltaic performance of all-conjugated poly(3-alkylthiophene) diblock The effects of thermal and solvent vapor annealing on the photovoltaic performance of a new class of all and solvent vapor annealing on the photovoltaic performance of all- conjugated P3BHT21 diblock copolymers

  8. 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.

  9. 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, Xi'an Jiaotong University, Xi'an, 710049 Shaanxi, People's Republic of China Joint Center *S Supporting Information ABSTRACT: We demonstrate an InP heterojunction solar cell employing

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

    E-Print Network [OSTI]

    Feenstra, Randall

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

  11. 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

  12. 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.

  13. Structural and Optical Investigations of GaN-Si Interface for a Heterojunction Solar Cell

    SciTech Connect (OSTI)

    Williams, Joshua J.; Jeffries, April M.; Bertoni, Mariana I.; Williamson, Todd L.; Bowden, Stuart G.; Honsberg, Christiana B.

    2014-06-08T23:59:59.000Z

    In recent years the development of heterojunction silicon based solar cells has gained much attention, lea largely by the efforts of Panasonic’s HIT cell. The success of the HIT cell prompts the scientific exploration of other thin film layers, besides the industrially accepted amorphous silicon. In this paper we report upon the use of gallium nitride, grown by MBE at “low temperatures” (~200°C), on silicon wafers as one possible candidate for making a heterojunction solar cell; the first approximation of band alignments between GaN and Si; and the material quality as determined by X-ray diffraction.

  14. Visualizing the photovoltaic behavior of a type-II p-n heterojunction superstructure

    SciTech Connect (OSTI)

    Xing, Juanjuan, E-mail: xingjuanjuan@mail.sic.ac.cn [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, 1295 Dingxi Road, Shanghai 200050 (China); Electron Microscopy Group, Surface Physics and Structure Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Takeguchi, Masaki [Electron Microscopy Group, Surface Physics and Structure Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Hashimoto, Ayako [Electron Microscopy Group, Surface Physics and Structure Unit, National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Global Research Center for Environment and Energy Based on Nanomaterials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047 (Japan); Cao, Junyu; Ye, Jinhua [International Center for Materials Nanoarchitectonics (WPI-MANA), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2014-04-21T23:59:59.000Z

    Photovoltaic behavior of a CaFe{sub 2}O{sub 4}/ZnFe{sub 2}O{sub 4} p-n multi-junction was investigated with electron holography combined with an in situ light irradiation system. Potential profiles of the samples with and without light irradiation were extracted to measure the open circuit photovoltage generated either by the whole heterojunction superstructure or from each p-n junction. Investigation on the variation in the energy band configuration under light irradiation revealed the mechanism involved in the photoelectric effect, with respect to the properties of the heterojunction and its periodic quantum structure.

  15. 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.

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

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

    Device Developments with Advanced Bulk Thermoelectric Materials at RTI Recent Device Developments with Advanced Bulk Thermoelectric Materials at RTI Reviews work in engineered...

  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. 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

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

    E-Print Network [OSTI]

    Ceder, Gerbrand

    materials for thin film solar cells such as CdTe and CIGS suffer from concerns over resource scarcity (eEARTH ABUNDANT MATERIALS FOR HIGH EFFICIENCY HETEROJUNCTION THIN FILM SOLAR CELLS Yun Seog Lee 1 conversion efficiencies should be increased. In terms of reducing module cost, thin film solar cells

  1. 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 solar cells. We proposed a water-vapor treatment to build up SWNTs to a self-assembled micro- honeycomb network for the application of solar cells [1]. The micro-honeycomb network consists of vertical

  2. 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.

  3. 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

  4. CNT-Si heterojunction solar cell with single-walled carbon nanotubes Shigeo Maruyama

    E-Print Network [OSTI]

    Maruyama, Shigeo

    CNT-Si heterojunction solar cell with single-walled carbon nanotubes Shigeo Maruyama Department solar cells. We proposed a water vapor treatment to build up SWNTs to a self-assembled micro-honeycomb network for the application of solar cells [1]. The micro- honeycomb network consists of vertical

  5. Controlled Growth of Single-Walled Carbon Nanotubes for CNT-Si heterojunction solar cell

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Controlled Growth of Single-Walled Carbon Nanotubes for CNT-Si heterojunction solar cell Shigeo two different SWNT assemblies for SWNT-Si heterojuction solar cells. We proposed a water vapor treatment to build up SWNTs to a self-assembled micro-honeycomb network for the application of solar cells

  6. 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%.

  7. IEEE BCTM1.3 Explorations for High Performance SiGe-HeterojunctionBipolar

    E-Print Network [OSTI]

    Technische Universiteit Delft

    IEEE BCTM1.3 Explorations for High Performance SiGe-HeterojunctionBipolar Transistor Integration P.Deixler@philips.com,Phone: -1 505 858 2960 Abstract We present a SiGe HBT integration-study, introducing a low-complexity integration-scheme. We demonstrate a stepped box-like SiGe base-profile designed to reduce reverse Early

  8. Charm contribution to bulk viscosity

    E-Print Network [OSTI]

    M. Laine; Kiyoumars A. Sohrabi

    2015-02-24T23:59:59.000Z

    In the range of temperatures reached in future heavy ion collision experiments, hadronic pair annihilations and creations of charm quarks may take place within the lifetime of the plasma. As a result, charm quarks may increase the bulk viscosity affecting the early stages of hydrodynamic expansion. Assuming thermalization, we estimate the charm contribution to bulk viscosity within the same effective kinetic theory framework in which the light parton contribution has been computed previously. The time scale at which this physics becomes relevant is related to the width of the transport peak associated with the trace anomaly correlator, and is found to be 600 MeV.

  9. Bulk Viscosity of Interacting Hadrons

    E-Print Network [OSTI]

    A. Wiranata; M. Prakash

    2009-09-16T23:59:59.000Z

    We show that first approximations to the bulk viscosity $\\eta_v$ are expressible in terms of factors that depend on the sound speed $v_s$, the enthalpy, and the interaction (elastic and inelastic) cross section. The explicit dependence of $\\eta_v$ on the factor $(\\frac 13 - v_s^2)$ is demonstrated in the Chapman-Enskog approximation as well as the variational and relaxation time approaches. The interesting feature of bulk viscosity is that the dominant contributions at a given temperature arise from particles which are neither extremely nonrelativistic nor extremely relativistic. Numerical results for a model binary mixture are reported.

  10. 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.

  11. 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 Hadas Shtrikman,a) M. Heiblum, K. Seo, D. E. Galbi, and L. Osterling IBM, ThomasJ. Watson Research

  12. 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.

  13. Bulk viscosity and deflationary universes

    E-Print Network [OSTI]

    J. A. S. Lima; R. Portugal; I. Waga

    2007-08-24T23:59:59.000Z

    We analyze the conditions that make possible the description of entropy generation in the new inflationary model by means of a nearequilibrium process. We show that there are situations in which the bulk viscosity cannot describe particle production during the coherent field oscillations phase.

  14. Bulk Hydrogen Strategic Directions for

    E-Print Network [OSTI]

    Economics Storage Performance Issues Market and Institutional Issues Storage Devices and Technologies-board) Develop new materials to address unique H2 leakage and Embrittlement Considerations Develop Smart Sensors Formations. #12;Breakout Session - Bulk Hydrogen Storage "Take home" messages Economics Cost of Storage vis

  15. Hanford Bulk Vitrification Technology Status

    SciTech Connect (OSTI)

    Witwer, Keith S.; Dysland, Eric J.; Bagaasen, Larry M.; Schlahta, Stephan N.; Kim, Dong-Sang; Schweiger, Michael J.; Hrma, Pavel R.

    2007-01-25T23:59:59.000Z

    Research and testing was initiated in 2003 to support the selection of a supplemental treatment technology for Hanford low-activity wastes (LAWs). AMEC’s bulk vitrification process was chosen for full-scale demonstration, and the Demonstration Bulk Vitrification System (DBVS) project was started in 2004. Also known as in-container vitrification™ (ICV™), the bulk vitrification process combines soil, liquid LAW, and additives (B2O3 and ZrO2); dries the mixture; and then vitrifies the material in a batch feed-while-melt process in a refractory lined steel container. The DBVS project was initiated with the intent to engineer, construct, and operate a full-scale bulk vitrification pilot-plant to treat LAW from Tank 241-S-109 at the U.S. Department of Energy (DOE) Hanford Site. AMEC is adapting its ICV™ technology for this application with technical and analytical support from Pacific Northwest National Laboratory (PNNL). The DBVS project is funded by the DOE Office of River Protection and administered by CH2M HILL Hanford Group, Inc. Since the beginning of the selection process in 2003, testing has utilized crucible-scale, engineering-scale, and full-scale bulk vitrification equipment. Crucible-scale testing, coupled with engineering-scale testing, helps establish process limitations of selected glass formulations. Full-scale testing provides critical design verification of the ICV™ process both before and during operation of the demonstration facility. Initial testing focused on development and validation of the baseline equipment configuration and glass formulation. Subsequent testing was focused on improvements to the baseline configuration. Many improvements have been made to the bulk vitrification system equipment configuration and operating methodology since its original inception. Challenges have been identified and met as part of the parallel testing and design process. A 100% design package for the pilot plant is complete and has been submitted to DOE for review. Additional testing will be performed to support both the DBVS project and LAW treatment for the full Hanford mission. In the near term, this includes testing some key equipment components such as the waste feed dryer and other integrated subsystems, as well as waste form process improvements. Additional testing will be conducted to verify that the system is adaptive to changing feed streams. This paper discusses the progress of the bulk vitrification system from its inception to its current state-of-the-art. Specific attention will be given to the testing and process design improvements that have been completed over the last year. These include the completion of full-scale ICV™ Test FS38C as well as process improvements to the feeding method, temperature control, and molten ionic salt separation control.

  16. Modelling of bulk superconductor magnetization

    E-Print Network [OSTI]

    Ainslie, M. D.; Fujishiro, H.

    2015-03-30T23:59:59.000Z

    synchronous motor. It may also be possible to use superconducting materials of different Tcs and a dual cooling system to develop an in-situ FC magnetization process for YBCO bulk plates using the superconducting stator coils of an electric machine... . Furthermore, the relative ease of fabrication of MgB2 materials, as well as their long coherence length [10], lower anisotropy and strongly linked supercurrent flow in untextured polycrystalline samples [11,12], has enabled a number of different processing...

  17. 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.

  18. High-performance InGaP/GaAs pnp {delta}-doped heterojunction bipolar transistor

    SciTech Connect (OSTI)

    Tsai, J.-H. [National Kaohsiung Normal University, Department of Electronic Engineering (China)], E-mail: jhtsai@nknucc.nknu.edu.tw; Chiu, S.-Y.; Lour, W.-S. [National Taiwan Ocean University, Department of Electrical Engineering (China); Guo, D.-F. [Air Force Academy, Department of Electronic Engineering (China)

    2009-07-15T23:59:59.000Z

    In this article, a novel InGaP/GaAs pnp {delta}-doped heterojunction bipolar transistor is first demonstrated. Though the valence band discontinuity at InGaP/GaAs heterojunction is relatively large, the addition of a {delta}-doped sheet between two spacer layers at the emitter-base (E-B) junction effectively eliminates the potential spike and increases the confined barrier for electrons, simultaneously. Experimentally, a high current gain of 25 and a relatively low E-B offset voltage of 60 mV are achieved. The offset voltage is much smaller than the conventional InGaP/GaAs pnp HBT. The proposed device could be used for linear amplifiers and low-power complementary integrated circuit applications.

  19. 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.

  20. 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.

  1. Free carrier accumulation at cubic AlGaN/GaN heterojunctions Q. Y. Wei,1

    E-Print Network [OSTI]

    As, Donat Josef

    ) substrate,7 with GaN and AlGaN layer thickness of 600 nm and 30 nm, respectively. The layer thicknessFree carrier accumulation at cubic AlGaN/GaN heterojunctions Q. Y. Wei,1 T. Li,1 J. Y. Huang,1 F. A (Received 24 February 2012; accepted 19 March 2012; published online 3 April 2012) Cubic Al0.3Ga0.7N/GaN

  2. Hanford bulk vitrification technology status

    SciTech Connect (OSTI)

    Witwer, K.S.; Dysland, E.J. [AMEC Nuclear Holdings Ltd., GeoMelt Division, Richland, Washington (United States); Bagaasen, L.M.; Schlahta, S.; Kim, D.S.; Schweiger, M.J.; Hrma, P. [Pacific Northwest National Laboratory, Richland, Washington (United States)

    2007-07-01T23:59:59.000Z

    Research and testing was initiated in 2003 to support the selection of a supplemental treatment technology for Hanford low-activity wastes (LAWs). AMEC's bulk vitrification process was chosen for full-scale demonstration, and the Demonstration Bulk Vitrification System (DBVS) project was started in 2004. Also known as In-Container Vitrification{sup TM} (ICV{sup TM}), the bulk vitrification process combines soil, liquid LAW, and additives (B{sub 2}O{sub 3} and ZrO{sub 2}); dries the mixture; and then vitrifies the material in a batch feed-while-melt process within a disposable, refractory-lined steel container. The DBVS project was initiated with the intent to engineer, construct, and operate a full-scale bulk vitrification pilot-plant to treat LAW from Tank 241-S-109 at the U.S. Department of Energy (DOE) Hanford Site. Since the beginning of the selection process in 2003, testing has utilized crucible-scale, engineering-scale, and full-scale bulk vitrification equipment. Crucible-scale testing, coupled with engineering-scale testing, helps establish process limitations of selected glass formulations. Full-scale testing provides critical design verification of the ICV{sup TM} process both before and during operation of the demonstration facility. Initial testing focused on development and validation of the melt container and the glass formulation. Subsequent testing was focused on improvements to the baseline configuration. Challenges have been identified and met as part of the parallel testing and design process. A 100% design package for the pilot plant is complete and has been submitted to DOE for review. Additional testing will be performed to support both the DBVS project and LAW treatment for the full Hanford mission. In the near term, this includes testing some key equipment components such as the waste feed mixer-dryer and other integrated subsystems, as well as waste form process improvements. Additional testing will be conducted to verify that the system is adaptive to changing feed streams. This paper discusses the progress of the bulk vitrification system from its inception to its current state-of- the-art. Specific attention will be given to the testing and process design improvements that have been completed over the last year. These include the completion of full-scale ICV{sup TM} Test FS38C as well as process improvements to the feeding method, temperature control, and molten ionic salt separation control. AMEC is adapting its ICV{sup TM} technology for this application with technical and analytical support from Pacific Northwest National Laboratory (PNNL) and design support from DMJN H and N. CH2M HILL Hanford Group, Inc. is the Prime Contractor for the DOE Office of River Protection for the DBVS contract. (authors)

  3. 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.

  4. Comparison of majority carrier charge transfer velocities at Si/polymer and Si/metal photovoltaic heterojunctions

    SciTech Connect (OSTI)

    Price, Michelle J.; Foley, Justin M. [Applied Physics Program, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040 (United States); May, Robert A. [Department of Chemistry and Biochemistry, University of Texas at Austin, 1 University Station A5300, Austin, Texas 78712-0165 (United States); Maldonado, Stephen [Applied Physics Program, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040 (United States); Department of Chemistry, University of Michigan, 930 N University, Ann Arbor, Michigan 48109-1055 (United States)

    2010-08-23T23:59:59.000Z

    Two sets of silicon (Si) heterojunctions with either Au or PEDOT:PSS contacts have been prepared to compare interfacial majority carrier charge transfer processes at Si/metal and Si/polymer heterojunctions. Current-voltage (J-V) responses at a range of temperatures, wavelength-dependent internal quantum yields, and steady-state J-V responses under illumination for these devices are reported. The cumulative data suggest that the velocity of majority carrier charge transfer, v{sub n}, is several orders of magnitude smaller at n-Si/PEDOT:PSS contacts than at n-Si/Au junctions, resulting in superior photoresponse characteristics for these inorganic/organic heterojunctions.

  5. High-performance zero-bias ultraviolet photodetector based on p-GaN/n-ZnO heterojunction

    SciTech Connect (OSTI)

    Su, Longxing; Zhang, Quanlin; Chen, Mingming; Su, Yuquan; Zhu, Yuan; Xiang, Rong; Gui, Xuchun [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Wu, Tianzhun, E-mail: tz.wu@siat.ac.cn [Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055 (China); Tang, Zikang, E-mail: phzktang@ust.hk [State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Department of Physics, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

    2014-08-18T23:59:59.000Z

    Lattice-match p-GaN and n-ZnO bilayers were heteroepitaxially grown on the c-sapphire substrate by metal organic chemical vapor deposition and molecular beam epitaxy technique, respectively. X-ray diffraction and photoluminescence investigations revealed the high crystal quality of the bilayer films. Subsequently, a p-GaN/n-ZnO heterojunction photodetector was fabricated. The p-n junction exhibited a clear rectifying I-V characteristic with a turn-on voltage of 3.7?V. At zero-bias voltage, the peak responsivity was 0.68?mA/W at 358?nm, which is one of the best performances reported for p-GaN/n-ZnO heterojunction detectors due to the excellent crystal quality of the bilayer films. These show that the high-performance p-GaN/n-ZnO heterojunction diode is potential for applications of portable UV detectors without driving power.

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. Bulk viscosity in kaon condensed matter

    E-Print Network [OSTI]

    Debarati Chatterjee; Debades Bandyopadhyay

    2007-05-30T23:59:59.000Z

    We investigate the effect of $K^-$ condensed matter on bulk viscosity and r-mode instability in neutron stars. The bulk viscosity coefficient due to the non-leptonic process $n \\rightleftharpoons p + K^-$ is studied here. In this connection, equations of state are constructed within the framework of relativistic field theoretical models where nucleon-nucleon and kaon-nucleon interactions are mediated by the exchange of scalar and vector mesons. We find that the bulk viscosity coefficient due to the non-leptonic weak process in the condensate is suppressed by several orders of magnitude. Consequently, kaon bulk viscosity may not damp the r-mode instability in neutron stars.

  11. 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.

  12. Bulk Storage Program Compliance Written Program

    E-Print Network [OSTI]

    Pawlowski, Wojtek

    Bulk Storage Program Compliance Written Program Cornell University 5/8/2013 #12;Bulk Storage.......................................................... 5 4.2.2 Aboveground Petroleum Storage Tanks­ University activities/operations designed to prevent releases of oil from Aboveground Petroleum Storage Tanks (ASTs) required to comply with following

  13. 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

  14. Molecular beam epitaxy of n-type ZnS: A wide band gap emitter for heterojunction PV devices

    E-Print Network [OSTI]

    Atwater, Harry

    Molecular beam epitaxy of n-type ZnS: A wide band gap emitter for heterojunction PV devices Jeffrey and AZO transparent conductive oxides did not. Applications to novel PV devices incorporating low electron-ray diffraction, zinc compounds. I. INTRODUCTION The growing interest in scalable, thin-film photovoltaics (PV

  15. 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

  16. Negative capacitance in GaN/AlGaN heterojunction dual-band detectors L. E. Byrum,1

    E-Print Network [OSTI]

    Dietz, Nikolaus

    Negative capacitance in GaN/AlGaN heterojunction dual-band detectors L. E. Byrum,1 G. Ariyawansa,1 online 2 September 2009 A study of trap states in n+ -GaN/AlGaN heterostructures using electrical related absorption centers attributed to shallow Si-donor pinned to the AlGaN barrier , N-vacancy/ C

  17. 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

  18. 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.

  19. 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.

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

    E-Print Network [OSTI]

    Sites, James R.

    80523 ABSTRACT Copper indium gallium sulfide, CuIn1-xGaxS2 (CIGS2) solar cells prepared with chemicalCuIn1-xGaxS2 thin film solar cells with ZnxCd1-xS as heterojunction partner Bhaskar Kumar 1 , Parag/heterojunction partner/ ZnO/Cr/Ag contact fingers solar cells of area ~0.44 cm 2 were fabricated at FSEC

  1. INVESTIGATION OF BULK POWER MIDWEST REGION

    E-Print Network [OSTI]

    Laughlin, Robert B.

    INVESTIGATION OF BULK POWER MARKETS MIDWEST REGION November 1, 2000 The analyses and conclusions Energy Regulatory Commission, any individual Commissioner, or the Commission itself #12;3-i Contents Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-3 A. Description of the Midwest

  2. Decision Models for Bulk Energy Transportation Networks

    E-Print Network [OSTI]

    Tesfatsion, Leigh

    emissions prices? How would CO2 regulations impact coal, gas, electricity, & SO2 markets? 3. Disruptions1 Decision Models for Bulk Energy Transportation Networks Electrical Engineering Professor Jim Mc: · integrated fuel, electricity networks · environmental impacts · electricity commodity markets · behavior

  3. Atomic-Layer-Deposited Transparent Electrodes for Silicon Heterojunction Solar Cells

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

    Demaurex, Benedicte; Seif, Johannes P.; Smit, Sjoerd; Macco, Bart; Kessels, W. M.; Geissbuhler, Jonas; De Wolf, Stefaan; Ballif, Christophe

    2014-11-01T23:59:59.000Z

    We examine damage-free transparent-electrode deposition to fabricate high-efficiency amorphous silicon/crystalline silicon heterojunction solar cells. Such solar cells usually feature sputtered transparent electrodes, the deposition of which may damage the layers underneath. Using atomic layer deposition, we insert thin protective films between the amorphous silicon layers and sputtered contacts and investigate their effect on device operation. We find that a 20-nm-thick protective layer suffices to preserve, unchanged, the amorphous silicon layers beneath. Insertion of such protective atomic-layer-deposited layers yields slightly higher internal voltages at low carrier injection levels. However, we identify the presence of a silicon oxide layer, formed during processing,more »between the amorphous silicon and the atomic-layer-deposited transparent electrode that acts as a barrier, impeding hole and electron collection.« less

  4. Bifacial Si Heterojunction-Perovskite Organic-Inorganic Tandem to Produce Highly Efficient Solar Cell

    E-Print Network [OSTI]

    Asadpour, Reza; Khan, M Ryyan; Alam, Muhammad A

    2015-01-01T23:59:59.000Z

    As single junction thin-film technologies, both Si heterojunction (HIT) and Perovskite based solar cells promise high efficiencies at low cost. One expects that a tandem cell design with these cells connected in series will improve the efficiency further. Using a self-consistent numerical modeling of optical and transport characteristics, however, we find that a traditional series connected tandem design suffers from low Jsc due to band-gap mismatch and current matching constraints. It requires careful thickness optimization of Perovskite to achieve any noticeable efficiency gain. Specifically, a traditional tandem cell with state-of-the-art HIT (24%) and Perovskite (20%) sub-cells provides only a modest tandem efficiency of ~25%. Instead, we demonstrate that a bifacial HIT/Perovskite tandem design decouples the optoelectronic constraints and provides an innovative path for extraordinary efficiencies. In the bifacial configuration, the same state-of the-art sub-cells achieve a normalized output of 33%, exceed...

  5. Quantum dot Ge/TiO{sub 2} heterojunction photoconductor fabrication and performance

    SciTech Connect (OSTI)

    Church, Carena P.; Carter, Sue A., E-mail: sacarter@ucsc.edu [Department of Physics, University of California Santa Cruz, Santa Cruz, California 95064 (United States); Muthuswamy, Elayaraja; Kauzlarich, Susan M. [Department of Chemistry, University of California Davis, Davis, California 95616 (United States)] [Department of Chemistry, University of California Davis, Davis, California 95616 (United States); Zhai, Guangmei [Key Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education, Taiyuan University of Science and Technology, Taiyuan, Shanxi 030024 (China)] [Key Laboratory of Interface Science and Engineering in Advanced Materials of Ministry of Education, Taiyuan University of Science and Technology, Taiyuan, Shanxi 030024 (China)

    2013-11-25T23:59:59.000Z

    Spun cast TiO{sub 2}-Ge quantum dot (QD) heterojunction type photodetectors have been fabricated and characterized, with interest paid to photocurrent enhancements related to device design. Performance as a function of absorber layer thickness, QD size, and back contact is investigated. We have achieved ultra-thin (?200?nm) devices with photocurrents at 0.5?V of 10{sup ?4} A cm{sup ?2} while the thickest devices have photocurrents at 0.5?V of 10{sup ?2} A cm{sup ?2} with on-off ratios >100, which represents 5 orders of magnitude increase in photocurrents over previously fabricated Ge QD devices. At 0.5?V bias, the currents in our devices are competitive with thin-film Ge photovoltaics.

  6. Atomic-Layer-Deposited Transparent Electrodes for Silicon Heterojunction Solar Cells

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

    Demaurex, Benedicte; Seif, Johannes P.; Smit, Sjoerd; Macco, Bart; Kessels, W. M.; Geissbuhler, Jonas; De Wolf, Stefaan; Ballif, Christophe

    2014-11-01T23:59:59.000Z

    We examine damage-free transparent-electrode deposition to fabricate high-efficiency amorphous silicon/crystalline silicon heterojunction solar cells. Such solar cells usually feature sputtered transparent electrodes, the deposition of which may damage the layers underneath. Using atomic layer deposition, we insert thin protective films between the amorphous silicon layers and sputtered contacts and investigate their effect on device operation. We find that a 20-nm-thick protective layer suffices to preserve, unchanged, the amorphous silicon layers beneath. Insertion of such protective atomic-layer-deposited layers yields slightly higher internal voltages at low carrier injection levels. However, we identify the presence of a silicon oxide layer, formed during processing, between the amorphous silicon and the atomic-layer-deposited transparent electrode that acts as a barrier, impeding hole and electron collection.

  7. 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.

  8. CdS/PbSe heterojunction for high temperature mid-infrared photovoltaic detector applications

    SciTech Connect (OSTI)

    Weng, Binbin, E-mail: binbinweng@ou.edu, E-mail: shi@ou.edu; Qiu, Jijun; Zhao, Lihua; Chang, Caleb [The School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Shi, Zhisheng, E-mail: binbinweng@ou.edu, E-mail: shi@ou.edu [The School of Electrical and Computer Engineering, University of Oklahoma, Norman, Oklahoma 73019 (United States); Nanolight, Inc., Norman, Oklahoma 73069 (United States)

    2014-03-24T23:59:59.000Z

    n-CdS/p-PbSe heterojunction is investigated. A thin CdS film is deposited by chemical bath deposition on top of epitaxial PbSe film by molecular beam epitaxy on Silicon. Current-voltage measurements demonstrate very good junction characteristics with rectifying ratio of ?178 and ideality factor of 1.79 at 300?K. Detectors made with such structure exhibit mid-infrared spectral photoresponse at room temperature. The peak responsivity R{sub ?} and specific detectivity D{sup *} are 0.055?A/W and 5.482?×?10{sup 8}?cm·Hz{sup 1/2}/W at ??=?4.7??m under zero-bias photovoltaic mode. Temperature-dependent photoresponse measurements show abnormal intensity variation below ?200?K. Possible reasons for this phenomenon are also discussed.

  9. FABRICATION OF A TITANIUM MICROELECTRODE CHIP TO INVESTIGATE BULK TITANIUM

    E-Print Network [OSTI]

    MacDonald, Noel C.

    FABRICATION OF A TITANIUM MICROELECTRODE CHIP TO INVESTIGATE BULK TITANIUM MICROMACHININING, USA Abstract Bulk titanium has a number of attractive characteristics that are favorable of a microelectrode chip for particle trapping and fundamental microfluidic studies. Keywords: bulk titanium

  10. 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...

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

    Open Energy Info (EERE)

    for bulk transmission. Date: Tuesday, 29 July, 2014 - 09:30 - 15:30 Location: NREL Education Center Auditorium Golden, Colorado Groups: Federal Bulk Transmission Regulatory...

  12. 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...

  13. 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...

  14. Vertical integration of an InGaAsP/InP heterojunction bipolar transistor and a double heterostructure laser

    SciTech Connect (OSTI)

    Chen, T.R.; Utaka, K.; Zhuang, Y.H.; Liu, Y.Y.; Yariv, A.

    1987-04-06T23:59:59.000Z

    A double heterostructure InGaAsP/InP mesa laser and a mass transport laser were integrated vertically with an InGaAsP/InP double heterojunction bipolar transistor, resulting in the first realization of laser operation in a vertical integration. Laser thresholds as low as 17 mA and an output laser power of over 30 mW were observed. A new type of bistable laser and electro-optical switching were demonstrated.

  15. A vertical monolithic combination of an InGaAsP/InP laser and a heterojunction bipolar transistor

    SciTech Connect (OSTI)

    Chen, T.R.; Utaka, K.; Zhuang, Y.; Liu, Y.Y.; Yariv, A.

    1987-06-01T23:59:59.000Z

    A DH InGaAsP/InP mesa laser and a DH InGaAsP/InP mass-transport laser were successfully put together with an InGaAsP/InP heterojunction bipolar transistor in a vertical configuration. A laser threshold current as low as 17 mA and an output laser power of over 30 mW were achieved. Base injection current-controlled optical bistability and optical switching were demonstrated.

  16. Fabrication technology of heterojunctions in the lattice of a 2D photonic crystal based on macroporous silicon

    SciTech Connect (OSTI)

    Zharova, Yu. A., E-mail: piliouguina@mail.ioffe.ru; Fedulova, G. V.; Astrova, E. V. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Baldycheva, A. V. [University of Dublin, Trinity College, Department of Electronic and Electrical Engineering (Ireland); Tolmachev, V. A. [Russian Academy of Sciences, Ioffe Physical Technical Institute (Russian Federation); Perova, T. S. [University of Dublin, Trinity College, Department of Electronic and Electrical Engineering (Ireland)

    2011-08-15T23:59:59.000Z

    Design and fabrication technology of a microcavity structure based on a double heterojunction in macroporous silicon is suggested. The fabrication process of a strip of a 2D photonic crystal constituted by a finite number of lattice periods and the technique for defect formation by local opening of macropores on the substrate side, followed by filling of these macropores with a nematic liquid crystal, are considered.

  17. 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}.

  18. 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.

  19. 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.

  20. Thermal relics in cosmology with bulk viscosity

    E-Print Network [OSTI]

    A. Iorio; G. Lambiase

    2014-11-28T23:59:59.000Z

    In this paper we discuss some consequences of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. The latter takes into account the dissipative effects (bulk viscosity) arising from different cooling rates of the fluid components in the expanding Universe. We discuss, in particular, the effects of the bulk viscosity on Big Bang Nucleosynthesis and on the thermal relic abundance of particles, looking at recent results of PAMELA experiment. The latter has determined an anomalous excess of positron events, that cannot be explained by the conventional cosmology and particle physics.

  1. New Approachesfor Bulk Power System Restoration

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    New Approachesfor Bulk Power System Restoration by AbbasKETABI M.Sc in Electrical EngineeringUniversity of Technology Department of Electrical Engineering, Teheran, Iran Supervisors: SHARIF Professor: Ali M. RANJBAR and complexity. Both factors increase the risk of major power outages. After a blackout, power needs

  2. Bulk viscosity in a cold CFL superfluid

    E-Print Network [OSTI]

    Cristina Manuel; Felipe Llanes-Estrada

    2007-07-18T23:59:59.000Z

    We compute one of the bulk viscosity coefficients of cold CFL quark matter in the temperature regime where the contribution of mesons, quarks and gluons to transport phenomena is Boltzmann suppressed. In that regime dissipation occurs due to collisions of superfluid phonons, the Goldstone modes associated to the spontaneous breaking of baryon symmetry. We first review the hydrodynamics of relativistic superfluids, and remind that there are at least three bulk viscosity coefficients in these systems. We then compute the bulk viscosity coefficient associated to the normal fluid component of the superfluid. In our analysis we use Son's effective field theory for the superfluid phonon, amended to include scale breaking effects proportional to the square of the strange quark mass m_s. We compute the bulk viscosity at leading order in the scale breaking parameter, and find that it is dominated by collinear splitting and joining processes. The resulting transport coefficient is zeta=0.011 m_s^4/T, growing at low temperature T until the phonon fluid description stops making sense. Our results are relevant to study the rotational properties of a compact star formed by CFL quark matter.

  3. 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.

  4. 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.

  5. 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.

  6. Bifacial Si Heterojunction-Perovskite Organic-Inorganic Tandem to Produce Highly Efficient Solar Cell

    E-Print Network [OSTI]

    Reza Asadpour; Raghu V. K. Chavali; M. Ryyan Khan; Muhammad A. Alam

    2015-05-15T23:59:59.000Z

    As single junction thin-film technologies, both Si heterojunction (HIT) and Perovskite based solar cells promise high efficiencies at low cost. One expects that a tandem cell design with these cells connected in series will improve the efficiency further. Using a self-consistent numerical modeling of optical and transport characteristics, however, we find that a traditional series connected tandem design suffers from low Jsc due to band-gap mismatch and current matching constraints. It requires careful thickness optimization of Perovskite to achieve any noticeable efficiency gain. Specifically, a traditional tandem cell with state-of-the-art HIT (24%) and Perovskite (20%) sub-cells provides only a modest tandem efficiency of ~25%. Instead, we demonstrate that a bifacial HIT/Perovskite tandem design decouples the optoelectronic constraints and provides an innovative path for extraordinary efficiencies. In the bifacial configuration, the same state-of the-art sub-cells achieve a normalized output of 33%, exceeding the bifacial HIT performance at practical albedo reflections. Unlike the traditional design, this bifacial design is relatively insensitive to Perovskite thickness variations, which may translate to simpler manufacture and higher yield.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

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

    DOE Patents [OSTI]

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

    1982-06-15T23:59:59.000Z

    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: (1) 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 (2), 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, is allowed.

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

    DOE Patents [OSTI]

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

    1982-01-01T23:59:59.000Z

    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 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 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.

  13. Self-aligned InGaP/GaAs heterojunction bipolar transistors for microwave power application

    SciTech Connect (OSTI)

    Ren, F.; Abernathy, C.R.; Pearton, S.J.; Lothian, J.R.; Wisk, P.W.; Fullowan, T.R.; Youngkai Chen (AT and T Bell Labs., Murray Hill, NJ (United States)); Yang, L.W.; Fu, S.T.; Brozovich, R.S. (General Electric Co., Syracuse, NY (USSR))

    1993-07-01T23:59:59.000Z

    As an alternative to AlGaAs/GaAs heterojunction bipolar transistors (HBT's) for microwave applications, InGaP/ GaAs HBT's with carbon-doped base layers grown by metal organic molecular beam epitaxy (MOMBE) are demonstrated with excellent dc, RF, and microwave performance. As previously reported, with a 700-[angstrom]-thick base layer (135-[Omega]/[open square] sheet resistance), a dc current gain of 25, and cutoff frequency and maximum frequency of oscillation above 70 GHz were measured for a 2 [times] 5-[mu]m[sup 2] emitter area device. A device with 12 cells, each consisting of a 2 [times] 15-[mu] m[sup 2] emitter area device for a total emitter area of 360 [mu] m[sup 2], was power tested at 4 GHz under continuous-wave (CW) bias condition. The device delivered 0.6-W output power with 13-dB linear gain and a power-added efficiency of 50%.

  14. 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.

  15. 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.

  16. Modeling direct interband tunneling. I. Bulk semiconductors

    SciTech Connect (OSTI)

    Pan, Andrew, E-mail: pandrew@ucla.edu [Department of Electrical Engineering, University of California, Los Angeles, Los Angeles, California 90095 (United States); Chui, Chi On [Department of Electrical Engineering, University of California, Los Angeles, Los Angeles, California 90095 (United States); California NanoSystems Institute, University of California, Los Angeles, Los Angeles, California 90095 (United States)

    2014-08-07T23:59:59.000Z

    Interband tunneling is frequently studied using the semiclassical Kane model, despite uncertainty about its validity. Revisiting the physical basis of this formula, we find that it neglects coupling to other bands and underestimates transverse tunneling. As a result, significant errors can arise at low and high fields for small and large gap materials, respectively. We derive a simple multiband tunneling model to correct these defects analytically without arbitrary parameters. Through extensive comparison with band structure and quantum transport calculations for bulk InGaAs, InAs, and InSb, we probe the accuracy of the Kane and multiband formulas and establish the superiority of the latter. We also show that the nonlocal average electric field should be used when applying either of these models to nonuniform potentials. Our findings are important for efficient analysis and simulation of bulk semiconductor devices involving tunneling.

  17. 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).

  18. 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).

  19. Bulk viscosity in heavy ion collision

    E-Print Network [OSTI]

    Victor Roy; A. K. Chaudhuri

    2012-01-20T23:59:59.000Z

    The effect of a temperature dependent bulk viscosity to entropy density ratio~($\\zeta/s$) along with a constant shear viscosity to entropy density ratio~($\\eta/s$) on the space time evolution of the fluid produced in high energy heavy ion collisions have been studied in a relativistic viscous hydrodynamics model. The boost invariant Israel-Stewart theory of causal relativistic viscous hydrodynamics is used to simulate the evolution of the fluid in 2 spatial and 1 temporal dimension. The dissipative correction to the freezeout distribution for bulk viscosity is calculated using Grad's fourteen moment method. From our simulation we show that the method is applicable only for $\\zeta/s<0.004$.

  20. 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.

  1. 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.

  2. Accelerating universes driven by bulk particles

    SciTech Connect (OSTI)

    Brito, F.A. [Departamento de Fisica, Universidade Federal de Campina Grande, 58109-970 Campina Grande, Paraiba (Brazil); Cruz, F.F.; Oliveira, J.F.N. [Departamento de Matematica, Universidade Regional do Cariri, 63040-000 Juazeiro do Norte, Ceara (Brazil)

    2005-04-15T23:59:59.000Z

    We consider our universe as a 3d domain wall embedded in a 5d dimensional Minkowski space-time. We address the problem of inflation and late time acceleration driven by bulk particles colliding with the 3d domain wall. The expansion of our universe is mainly related to these bulk particles. Since our universe tends to be permeated by a large number of isolated structures, as temperature diminishes with the expansion, we model our universe with a 3d domain wall with increasing internal structures. These structures could be unstable 2d domain walls evolving to fermi-balls which are candidates to cold dark matter. The momentum transfer of bulk particles colliding with the 3d domain wall is related to the reflection coefficient. We show a nontrivial dependence of the reflection coefficient with the number of internal dark matter structures inside the 3d domain wall. As the population of such structures increases the velocity of the domain wall expansion also increases. The expansion is exponential at early times and polynomial at late times. We connect this picture with string/M-theory by considering BPS 3d domain walls with structures which can appear through the bosonic sector of a five-dimensional supergravity theory.

  3. 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.

  4. 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.

  5. Characteristics of Novel InGaAsN Double Heterojunction Bipolar Transistors

    SciTech Connect (OSTI)

    LI,N.Y.; CHANG,PING-CHIH; BACA,ALBERT G.; LAROCHE,J.R.; REN,F.; ARMOUR,E.; SHARPS,P.R.; HOU,H.Q.

    2000-08-01T23:59:59.000Z

    The authors demonstrate, for the first time, both functional Pnp AlGaAs/InGaAsN/GaAs (Pnp InGaAsN) and Npn InGaP/InGaAsN/GaAs (Npn InGaAsN) double heterojunction bipolar transistors (DHBTs) using a 1.2 eV In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} as the base layer for low-power electronic applications. The Pnp InGaAsN DHBT has a peak current gain ({beta}) of 25 and a low turn-on voltage (V{sub ON}) of 0.79 V. This low V{sub ON} is {approximately} 0.25 V lower than in a comparable Pnp AlGAAs/GaAs HBT. For the Npn InGaAsN DHBT, it has a low V{sub ON} of 0.81 V, which is 0.13 V lower than in an InGaP/GaAs HBT. A peak {beta} of 7 with nearly ideal I-V characteristics has been demonstrated. Since GaAs is used as the collector of both Npn and Pnp InGaAsN DHBTs, the emitter-collector breakdown voltage (BV{sub CEO}) are 10 and 12 V, respectively, consistent with the BV{sub CEO} of Npn InGaP/GaAs and Pnp AlGaAs/GaAs HBTs of comparable collector thickness and doping level. All these results demonstrate the potential of InGaAsN DHBTs as an alternative for application in low-power electronics.

  6. 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

  7. Bulk viscosity of gauge theory plasma at strong coupling

    E-Print Network [OSTI]

    Alex Buchel

    2007-09-01T23:59:59.000Z

    We propose a lower bound on bulk viscosity of strongly coupled gauge theory plasmas. Using explicit example of the N=2^* gauge theory plasma we show that the bulk viscosity remains finite at a critical point with a divergent specific heat. We present an estimate for the bulk viscosity of QGP plasma at RHIC.

  8. Bulk viscosity and r-modes of neutron stars

    E-Print Network [OSTI]

    Debarati Chatterjee; Debades Bandyopadhyay

    2008-08-08T23:59:59.000Z

    The bulk viscosity due to the non-leptonic process involving hyperons in $K^-$ condensed matter is discussed here. We find that the bulk viscosity is modified in a superconducting phase. Further, we demonstrate how the exotic bulk viscosity coefficient influences $r$-modes of neutron stars which might be sources of detectable gravitational waves.

  9. 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.

  10. Bulk viscosity effects on elliptic flow

    E-Print Network [OSTI]

    G. S. Denicol; T. Kodama; T. Koide; Ph. Mota

    2009-09-30T23:59:59.000Z

    The effects of bulk viscosity on the elliptic flow $v_{2}$ are studied using realistic equation of state and realistic transport coefficients. We find that thebulk viscosity acts in a non trivial manner on $v_{2}$. At low $p_{T}$, the reduction of $v_{2}$ is even more effective compared to the case of shear viscosity, whereas at high $p_{T}$, an enhancement of $v_{2}$ compared to the ideal case is observed. We argue that this is caused by the competition of the critical behavior of the equation of state and the transport coefficients.

  11. 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.

  12. RAPID/Bulk Transmission | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I GeothermalPotentialBiopowerSolidGenerationMethod JumpGeorgia: EnergyOnline Permitting SystemsBulk

  13. 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; Li, Zhongrui; Bourdo, Shawn; Kunets, Vasyl P.; Trigwell, Steven; Couraud, Arthur; Rioux, Julien; Boyer, Cyril; Nteziyaremye, Valens; Dervishi, Enkeleda; et al

    2011-01-01T23:59:59.000Z

    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, whilemore »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.« less

  14. Band offsets of TiZnSnO/Si heterojunction determined by x-ray photoelectron spectroscopy

    SciTech Connect (OSTI)

    Sun, R. J.; Jiang, Q. J.; Yan, W. C.; Feng, L. S.; Lu, B.; Ye, Z. Z. [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Li, X. F. [Key Laboratory of Advanced Display and System Application, Ministry of Education, Shanghai University, Shanghai 200072 (China); Li, X. D. [Xinyi PV Products (Anhui) Holdings LTD, Xinyi PV Glass Industrial Zone, No. 2 Xinyi Road, ETDZ, Wuhu 241009 (China); Lu, J. G., E-mail: lujianguo@zju.edu.cn [State Key Laboratory of Silicon Materials, Department of Materials Science and Engineering, Zhejiang University, Hangzhou 310027 (China); Key Laboratory of Advanced Display and System Application, Ministry of Education, Shanghai University, Shanghai 200072 (China)

    2014-09-28T23:59:59.000Z

    X-ray photoelectron spectroscopy (XPS) was utilized to measure the valence band offset (?E{sub V}) of the TiZnSnO (TZTO)/Si heterojunction. TZTO films were deposited on Si (100) substrates using magnetron sputtering at room temperature. By using the Zn 2p{sub 3/2} and Sn 3d{sub 5/2} energy levels as references, the value of ?E{sub V} was calculated to be 2.69 ± 0.1 eV. Combining with the experimental optical energy band gap of 3.98 eV for TZTO extracted from the UV-vis transmittance spectrum, the conduction band offset (?E{sub C}) was deduced to be 0.17 ± 0.1 eV at the interface. Hence, the energy band alignment of the heterojunction was determined accurately, showing a type-I form. This will be beneficial for the design and application of TZTO/Si hybrid devices.

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

    SciTech Connect (OSTI)

    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.

  16. InGaP/InGaAsN/GaAs NpN double-heterojunction bipolar transistor

    SciTech Connect (OSTI)

    Chang, P. C. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Baca, A. G. [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States)] [Sandia National Laboratories, Albuquerque, New Mexico 87123 (United States); Li, N. Y. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States)] [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Xie, X. M. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States)] [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Hou, H. Q. [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States)] [Emcore Photovoltaics, Emcore Corporation, Albuquerque, New Mexico 87123 (United States); Armour, E. [Emcore Corporation, Somerset, New Jersey 08873 (United States)] [Emcore Corporation, Somerset, New Jersey 08873 (United States)

    2000-04-17T23:59:59.000Z

    We have demonstrated a functional NpN double-heterojunction bipolar transistor (DHBT) using InGaAsN for the base layer. The InGaP/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01}/GaAs DHBT has a low V{sub ON} of 0.81 V, which is 0.13 V lower than in a InGaP/GaAs heterojunction bipolar transistor (HBT). The lower turn-on voltage is attributed to the smaller band gap (1.20 eV) of metalorganic chemical vapor deposition-grown In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} base layer. GaAs is used for the collector; thus the breakdown voltage (BV{sub CEO}) is 10 V, consistent with the BV{sub CEO} of InGaP/GaAs HBTs of comparable collector thickness and doping level. To alleviate the current blocking phenomenon caused by the larger conduction band discontinuity between InGaAsN and GaAs, a graded InGaAs layer with {delta} doping is inserted at the base-collector junction. The improved device has a peak current gain of seven with ideal current-voltage characteristics. (c) 2000 American Institute of Physics.

  17. Effect of High-Voltage Heterojunction Bipolar Transistor Collector Design on f(T) and f(MAX)

    SciTech Connect (OSTI)

    Ashby, C.I.H.; Baca, A.G.; Chang, P.C.; Hietala, V.M.

    1999-03-02T23:59:59.000Z

    High-speed InGaP/GaAs heterojunction bipolar transistors (HBTs) for high-voltage circuit applications have been investigated. In order to obtain ideal IV characteristics, a lightly doped (N{sub DC} = 7.5 x 10{sup 15} cm{sup {minus}3}) thick (W{sub C} = 3.5 {micro}m) layer of GaAs was used as the collector layer. The devices fabricated have shown breakdown voltage exceeding 65 V. Device operated at up to a 60V bias, which is the highest operating voltage reported up to date for single heterojunction HBTs. Peak {line_integral}{sub T} and {line_integral}{sub MAX} values of 18 GHz and 29 GHz, respectively, have been achieved on a device with emitter area of 4x 12.5 {micro}m{sup 2}. Both {line_integral}{sub T} and {line_integral}{sub Max} degrades with higher bias, which is related to the elongation of the collector depletion width.

  18. 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.

  19. IEEE MICROWAVE AND WIRELESS COMPONENTS LETTERS, VOL. 11, NO. 10, OCTOBER 2001 401 Reliability of Microwave SiGe/Si Heterojunction

    E-Print Network [OSTI]

    Rieh, Jae-Sung

    of Microwave SiGe/Si Heterojunction Bipolar Transistors Zhenqiang Ma, Student Member, IEEE, Pallab Bhattacharya, Member, IEEE, and Edward T. Croke Abstract--The degradation behavior of NPN Si/SiGe/Si het- erojunction, REID, SiGe HBT. I. INTRODUCTION THE FAVORABLE high-frequency characteristics exhib- ited by Si/SiGe

  20. The Bulk Channel in Thermal Gauge Theories

    E-Print Network [OSTI]

    Harvey B. Meyer

    2010-02-17T23:59:59.000Z

    We investigate the thermal correlator of the trace of the energy-momentum tensor in the SU(3) Yang-Mills theory. Our goal is to constrain the spectral function in that channel, whose low-frequency part determines the bulk viscosity. We focus on the thermal modification of the spectral function, $\\rho(\\omega,T)-\\rho(\\omega,0)$. Using the operator-product expansion we give the high-frequency behavior of this difference in terms of thermodynamic potentials. We take into account the presence of an exact delta function located at the origin, which had been missed in previous analyses. We then combine the bulk sum rule and a Monte-Carlo evaluation of the Euclidean correlator to determine the intervals of frequency where the spectral density is enhanced or depleted by thermal effects. We find evidence that the thermal spectral density is non-zero for frequencies below the scalar glueball mass $m$ and is significantly depleted for $m\\lesssim\\omega\\lesssim 3m$.

  1. 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.

  2. 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.

  3. On bulk viscosity and moduli decay

    E-Print Network [OSTI]

    M. Laine

    2010-11-21T23:59:59.000Z

    This pedagogically intended lecture, one of four under the header "Basics of thermal QCD", reviews an interesting relationship, originally pointed out by Bodeker, that exists between the bulk viscosity of Yang-Mills theory (of possible relevance to the hydrodynamics of heavy ion collision experiments) and the decay rate of scalar fields coupled very weakly to a heat bath (appearing in some particle physics inspired cosmological scenarios). This topic serves, furthermore, as a platform on which a number of generic thermal field theory concepts are illustrated. The other three lectures (on the QCD equation of state and the rates of elastic as well as inelastic processes experienced by heavy quarks) are recapitulated in brief encyclopedic form.

  4. 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.

  5. 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.

  6. Macroscopic and direct light propulsion of bulk graphene material

    E-Print Network [OSTI]

    Zhang, Tengfei; Wu, Yingpeng; Xiao, Peishuang; Yi, Ningbo; Lu, Yanhong; Ma, Yanfeng; Huang, Yi; Zhao, Kai; Yan, Xiao-Qing; Liu, Zhi-Bo; Tian, Jian-Guo; Chen, Yongsheng

    2015-01-01T23:59:59.000Z

    It has been a great challenge to achieve the direct light manipulation of matter on a bulk scale. In this work, the direct light propulsion of matter was observed on a macroscopic scale for the first time using a bulk graphene based material. The unique structure and properties of graphene and the morphology of the bulk graphene material make it capable of not only absorbing light at various wavelengths but also emitting energetic electrons efficiently enough to drive the bulk material following Newtonian mechanics. Thus, the unique photonic and electronic properties of individual graphene sheets are manifested in the response of the bulk state. These results offer an exciting opportunity to bring about bulk scale light manipulation with the potential to realize long-sought proposals in areas such as the solar sail and space transportation driven directly by sunlight.

  7. ENVIRONMENTAL BIOTECHNOLOGY Effect of bulk liquid BOD concentration on activity

    E-Print Network [OSTI]

    Nerenberg, Robert

    BOD. FISH results indicated increasing abundance of heterotrophs with increasing bulk liquid BOD); however, competition of heterotrophs and nitrifiers in biofilm systems limits nitrification rates

  8. 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)

  9. Economic manufacturing of bulk metallic glass compositions by microalloying

    DOE Patents [OSTI]

    Liu, Chain T.

    2003-05-13T23:59:59.000Z

    A method of making a bulk metallic glass composition includes the steps of:a. providing a starting material suitable for making a bulk metallic glass composition, for example, BAM-11; b. adding at least one impurity-mitigating dopant, for example, Pb, Si, B, Sn, P, to the starting material to form a doped starting material; and c. converting the doped starting material to a bulk metallic glass composition so that the impurity-mitigating dopant reacts with impurities in the starting material to neutralize deleterious effects of the impurities on the formation of the bulk metallic glass composition.

  10. 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,

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

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

    Nanostructured High-Temperature Bulk Thermoelectric Energy Conversion for Efficient Automotive Waste Heat Recovery Vehicle Technologies Office Merit Review 2014: Nanostructured...

  12. Bulk viscosity of QCD matter near the critical temperature

    E-Print Network [OSTI]

    D. Kharzeev; K. Tuchin

    2007-05-29T23:59:59.000Z

    Kubo's formula relates bulk viscosity to the retarded Green's function of the trace of the energy-momentum tensor. Using low energy theorems of QCD for the latter we derive the formula which relates the bulk viscosity to the energy density and pressure of hot matter. We then employ the available lattice QCD data to extract the bulk viscosity as a function of temperature. We find that close to the deconfinement temperature bulk viscosity becomes large, with viscosity-to-entropy ratio zeta/s about 1.

  13. On Eling-Oz formula for the holographic bulk viscosity

    E-Print Network [OSTI]

    Alex Buchel

    2011-05-09T23:59:59.000Z

    Recently Eling and Oz [1] proposed a simple formula for the bulk viscosity of holographic plasma. They argued that the formula is valid in the high temperature (near-conformal) regime, but is expected to break down at low temperatures. We point out that the formula is in perfect agreement with the previous computations of the bulk viscosity of the cascading plasma [2,3], as well as with the previous computations of the bulk viscosity of N=2^* plasma [4,5]. In the latter case it correctly reproduces the critical behaviour of the bulk viscosity in the vicinity of the critical point with the vanishing speed of sound.

  14. Light-Emitting Diodes on Semipolar Bulk Gallium Nitride Substrate...

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

    semipolar light-emitting diodes (LEDs) on low-defect bulk gallium nitride (GaN) substrates. Peak internal quantum efficiency (IQE) values of greater than 80% are...

  15. 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.

  16. Thermodynamic properties of bulk and confined water

    SciTech Connect (OSTI)

    Mallamace, Francesco, E-mail: francesco.mallamace@unime.it [Dipartimento di Fisica e Scienza della Terra Università di Messina and CNISM, I-98168 Messina (Italy); Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States); Corsaro, Carmelo [Dipartimento di Fisica e Scienza della Terra Università di Messina and CNISM, I-98168 Messina (Italy); Mallamace, Domenico [Dipartimento di Scienze dell'Ambiente, della Sicurezza, del Territorio, degli Alimenti e della Salute, Università di Messina, I-98166 Messina (Italy); Vasi, Sebastiano; Vasi, Cirino [IPCF-CNR, I-98166 Messina (Italy); Stanley, H. Eugene [Center for Polymer Studies and Department of Physics, Boston University, Boston, Massachusetts 02215 (United States)

    2014-11-14T23:59:59.000Z

    The thermodynamic response functions of water display anomalous behaviors. We study these anomalous behaviors in bulk and confined water. We use nuclear magnetic resonance (NMR) to examine the configurational specific heat and the transport parameters in both the thermal stable and the metastable supercooled phases. The data we obtain suggest that there is a behavior common to both phases: that the dynamics of water exhibit two singular temperatures belonging to the supercooled and the stable phase, respectively. One is the dynamic fragile-to-strong crossover temperature (T{sub L} ? 225 K). The second, T{sup *} ? 315 ± 5 K, is a special locus of the isothermal compressibility K{sub T}(T, P) and the thermal expansion coefficient ?{sub P}(T, P) in the P–T plane. In the case of water confined inside a protein, we observe that these two temperatures mark, respectively, the onset of protein flexibility from its low temperature glass state (T{sub L}) and the onset of the unfolding process (T{sup *})

  17. Bulk viscous cosmology: statefinder and entropy

    E-Print Network [OSTI]

    M. Hu; Xin He Meng

    2005-11-23T23:59:59.000Z

    The statefinder diagnostic pair is adopted to differentiate viscous cosmology models and it is found that the trajectories of these viscous cosmology models on the statefinder pair $s-r$ plane are quite different from those of the corresponding non-viscous cases. Particularly for the quiessence model, the singular properties of state parameter $w=-1$ are obviously demonstrated on the statefinder diagnostic pair planes. We then discuss the entropy of the viscous / dissipative cosmology system which may be more practical to describe the present cosmic observations as the perfect fluid is just a global approximation to the complicated cosmic media in current universe evolution. When the bulk viscosity takes the form of $\\zeta=\\zeta_{1}\\dot{a}/a$($\\zeta_{1}$ is constant), the relationship between the entropy $S$ and the redshift $z$ is explicitly given out. We find that the entropy of the viscous cosmology is always increasing and consistent with the thermodynamics arrow of time for the universe evolution. With the parameter constraints from fitting to the 157 gold data of supernova observations, it is demonstrated that this viscous cosmology model is rather well consistent to the observational data at the lower redshifts, and together with the diagnostic statefinder pair analysis it is concluded that the viscous cosmic models tend to the favored $\\Lambda$CDM model in the later cosmic evolution, agreeable to lots of cosmological simulation results, especially to the fact of confidently observed current accelerating cosmic expansion.

  18. 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.

  19. 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.

  20. BULK MICROMACHINED TITANIUM MICROMIRROR DEVICE WITH SLOPING ELECTRODE GEOMETRY

    E-Print Network [OSTI]

    MacDonald, Noel C.

    BULK MICROMACHINED TITANIUM MICROMIRROR DEVICE WITH SLOPING ELECTRODE GEOMETRY Masa P. Rao1 , Marco micromachined hybrid torsional micromirror device composed of titanium mirror structures bonded to an underlying time, high aspect ratio micromachining capability in bulk titanium; and 2) the High Aspect Ratio

  1. 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

  2. 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.

  3. 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.

  4. Comparison of sub-micron Si:SiGe heterojunction nFETs to Si nMOSFET in present-day technologies

    E-Print Network [OSTI]

    Papavassiliou, Christos

    Comparison of sub-micron Si:SiGe heterojunction nFETs to Si nMOSFET in present-day technologies K.K. Maiti Abstract The measured performance of sub-micron Si:SiGe Schottky gated HFETs is compared to Si n frequency is given as a function of input power. The evaluation highlights the current immaturity of the Si:SiGe

  5. InGaP/GaAs/InGaP double-heterojunction bipolar transistors grown by solid-source molecular-beam epitaxy with a valved phosphorus cracker

    E-Print Network [OSTI]

    Woodall, Jerry M.

    InGaP/GaAs/InGaP double-heterojunction bipolar transistors grown by solid-source molecular; accepted 17 November 1995 The growth and device characterization of an InGaP/GaAs double-quality phosphorus-containing compounds.1­4 The growth of high-performance InGaP/ GaAs and InGaAs/InP single

  6. Graded-base InGaN/GaN heterojunction bipolar light-emitting transistors B. F. Chu-Kung,a

    E-Print Network [OSTI]

    Asbeck, Peter M.

    Graded-base InGaN/GaN heterojunction bipolar light-emitting transistors B. F. Chu-Kung,a M. Feng, G; published online 25 August 2006 The authors report radiative recombination from a graded-base InGaN/GaN microwave power has been obtained from GaN field-effect transistors, very few operational GaN-based HBTs

  7. Cubic AlGaN/GaN Hetero-Junction Field-Effect Transistors with Normally-on and Normally-off

    E-Print Network [OSTI]

    As, Donat Josef

    Cubic AlGaN/GaN Hetero-Junction Field-Effect Transistors with Normally-on and Normally-effect transistors (HFETs) in GaN technology. HFET structures were fabricated of non-polar cubic AlGaN/GaN hetero insulation of 3C-SiC was realized by Ar+ implantation before c-AlGaN/GaN growth. HFETs with normally

  8. Substrate nitridation induced modulations in transport properties of wurtzite GaN/p-Si (100) heterojunctions grown by molecular beam epitaxy

    SciTech Connect (OSTI)

    Bhat, Thirumaleshwara N.; Rajpalke, Mohana K.; Krupanidhi, S. B. [Materials Research Centre, Indian Institute of Science, Bangalore- 560012 (India); Roul, Basanta; Kumar, Mahesh [Materials Research Centre, Indian Institute of Science, Bangalore- 560012 (India); Central Research Laboratory, Bharat Electronics, Bangalore-560013 (India)

    2011-11-01T23:59:59.000Z

    Phase pure wurtzite GaN films were grown on Si (100) substrates by introducing a silicon nitride layer followed by low temperature GaN growth as buffer layers. GaN films grown directly on Si (100) were found to be phase mixtured, containing both cubic ({beta}) and hexagonal ({alpha}) modifications. The x-ray diffraction (XRD), scanning electron microscopy (SEM), photoluminescence (PL) spectroscopy studies reveal that the significant enhancement in the structural as well as in the optical properties of GaN films grown with silicon nitride buffer layer grown at 800 deg. C when compared to the samples grown in the absence of silicon nitride buffer layer and with silicon nitride buffer layer grown at 600 deg. C. Core-level photoelectron spectroscopy of Si{sub x}N{sub y} layers reveals the sources for superior qualities of GaN epilayers grown with the high temperature substrate nitridation process. The discussion has been carried out on the typical inverted rectification behavior exhibited by n-GaN/p-Si heterojunctions. Considerable modulation in the transport mechanism was observed with the nitridation conditions. The heterojunction fabricated with the sample of substrate nitridation at high temperature exhibited superior rectifying nature with reduced trap concentrations. Lowest ideality factors ({approx}1.5) were observed in the heterojunctions grown with high temperature substrate nitridation which is attributed to the recombination tunneling at the space charge region transport mechanism at lower voltages and at higher voltages space charge limited current conduction is the dominating transport mechanism. Whereas, thermally generated carrier tunneling and recombination tunneling are the dominating transport mechanisms in the heterojunctions grown without substrate nitridation and low temperature substrate nitridation, respectively.

  9. Nonpolar cubic AlGaN/GaN heterojunction field-effect transistor on Ar+ implanted 3CSiC ,,001...

    E-Print Network [OSTI]

    As, Donat Josef

    through the substrate. Cubic AlGaN/GaN heterostructures were grown in a RibeNonpolar cubic AlGaN/GaN heterojunction field-effect transistor on Ar+ implanted 3C­SiC ,,001... E HFET was fabricated of nonpolar cubic AlGaN/GaN grown on Ar+ implanted 3C­SiC 001 by molecular beam

  10. 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.

  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. 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 $w^{\\mathrm{eff}}_D\\geq-1$.

  13. 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.

  14. Bulk viscosity, chemical equilibration and flow at RHIC

    E-Print Network [OSTI]

    Thomas Schaefer; Kevin Dusling

    2012-10-15T23:59:59.000Z

    We study the effects of bulk viscosity on p_T spectra and elliptic flow in heavy ion collisions at RHIC. We argue that direct effect of the bulk viscosity on the evolution of the velocity field is small, but corrections to the freezeout distributions can be significant. These effects are dominated by chemical non-equilibration in the hadronic phase. We show that a non-zero bulk viscosity in the range $\\zeta/s \\lsim 0.05$ improves the description of spectra and flow at RHIC.

  15. Resonant circular photogalvanic effect in GaN/AlGaN heterojunctions B. Wittmann,1 L. E. Golub,2 S. N. Danilov,1 J. Karch,1 C. Reitmaier,1 Z. D. Kvon,3 N. Q. Vinh,4 A. F. G. van der Meer,4

    E-Print Network [OSTI]

    Ganichev, Sergey

    Resonant circular photogalvanic effect in GaN/AlGaN heterojunctions B. Wittmann,1 L. E. Golub,2 S circular photogalvanic effect is observed in wurtzite 0001 -oriented GaN low-dimensional structures excited electrons at resonant intersubband optical transitions in a GaN/AlGaN heterojunction. The signal reverses

  16. 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 ...

  17. High-power-density spot cooling using bulk thermoelectrics

    E-Print Network [OSTI]

    Zhang, Y; Shakouri, A; Zeng, G H

    2004-01-01T23:59:59.000Z

    model, the cooling power densities of the devices can alsothe cooling power densities 2–24 times. Experimentally, the14 4 OCTOBER 2004 High-power-density spot cooling using bulk

  18. Photonic integration in a commercial scaled bulk-CMOS process

    E-Print Network [OSTI]

    Kaertner, Franz X.

    We demonstrate the first photonic chip designed for a commercial bulk CMOS process (65 nm-node) using standard process layers combined with post-processing, enabling dense photonic integration with high-performance ...

  19. 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 ...

  20. New nano structure approaches for bulk thermoelectric materials

    E-Print Network [OSTI]

    Kim, Jeonghoon

    2010-01-01T23:59:59.000Z

    developments in bulk thermoelectric materials", M. Mater.and M. D. Drsselhaus, "Thermoelectric figure of merit of aO'Quinn, " Thin-film thermoelectric devices with high room-

  1. Bulk Viscosity Effects in Event-by-Event Relativistic Hydrodynamics

    E-Print Network [OSTI]

    Jacquelyn Noronha-Hostler; Gabriel S. Denicol; Jorge Noronha; Rone P. G. Andrade; Frederique Grassi

    2013-05-10T23:59:59.000Z

    Bulk viscosity effects on the collective flow harmonics in heavy ion collisions are investigated, on an event by event basis, using a newly developed 2+1 Lagrangian hydrodynamic code named v-USPhydro which implements the Smoothed Particle Hydrodynamics (SPH) algorithm for viscous hydrodynamics. A new formula for the bulk viscous corrections present in the distribution function at freeze-out is derived starting from the Boltzmann equation for multi-hadron species. Bulk viscosity is shown to enhance the collective flow Fourier coefficients from $v_2(p_T)$ to $v_5(p_T)$ when $% p_{T}\\sim 1-3$ GeV even when the bulk viscosity to entropy density ratio, $% \\zeta/s$, is significantly smaller than $1/(4\\pi)$.

  2. Bulk viscosity in nuclear and quark matter: A short review

    E-Print Network [OSTI]

    Hui Dong; Nan Su; Qun Wang

    2007-03-05T23:59:59.000Z

    The history and recent progresses in the study of bulk viscosity in nuclear and quark matter are reviewed. The constraints from baryon number conservation and electric neutrality in quark matter on particle densities and fluid velocity divergences are discussed.

  3. Efficient Bulk Data Replication for the Earth System Grid

    E-Print Network [OSTI]

    Sim, Alex

    2010-01-01T23:59:59.000Z

    Bulk Data Replication for the Earth System Grid Alex Sim 1 ,CA 94720, USA Abstract The Earth System Grid (ESG) communityNetLogger 1. Introduction The Earth System Grid (ESG) [1

  4. abdominal bulking mass: Topics by E-print Network

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

    Y. Burnier; M. Laine 2013-11-13 4 Neutrino mass, bulk majoron and neutrinoless double beta decay HEP - Phenomenology (arXiv) Summary: A new economical model for neutrino...

  5. Supply chain management in the dry bulk shipping industry

    E-Print Network [OSTI]

    Nicholson, Bryan E. (Bryan Edward)

    2006-01-01T23:59:59.000Z

    This paper is intended to show the importance of supply chain management in the dry-bulk shipping industry. A hypothetical company, the Texas Grain and Bakery Corporation, was created. The values and calculations used are ...

  6. Bulk viscosity and the conformal anomaly in the pion gas

    E-Print Network [OSTI]

    D. Fernandez-Fraile; A. Gomez Nicola

    2009-02-27T23:59:59.000Z

    We calculate the bulk viscosity of the massive pion gas within Unitarized Chiral Perturbation Theory. We obtain a low temperature peak arising from explicit conformal breaking due to the pion mass and another peak near the critical temperature, dominated by the conformal anomaly through gluon condensate terms. The correlation between bulk viscosity and conformal breaking supports a recent QCD proposal. We discuss the role of resonances, heavier states and large-$N_c$ counting.

  7. 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...

  8. 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.

  9. InGaP/InGaAsN/GaAs NpN double heterojunction bipolar transistor

    SciTech Connect (OSTI)

    Chang, P.C.; Baca, A.G.; Li, N.Y.; Xie, X.M.; Sharps, P.R.; Hou, H.Q.

    2000-01-10T23:59:59.000Z

    The authors have demonstrated a functional NpN double heterojunction bipolar transistor (DHBT) using InGaAsN for base layer. The InGaP/In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01}/GaAs DHBT has a low V{sub ON} of 0.81 V, which is 0.13 V lower than in a InGaP/GaAs HBT. The lower V{sub ON} is attributed to the smaller bandgap (E{sub g}=1.20eV) of MOCVD grown In{sub 0.03}Ga{sub 0.97}As{sub 0.99}N{sub 0.01} base layer. GaAs is used for the collector; thus the BV{sub CEO} is 10 V, consistent with the BV{sub CEO} of InGaP/GaAs Hbts of comparable collector thickness and doping level. To alleviate the current blocking phenomenon caused by the larger {triangle}E{sub C} between InGaAsN and GaAs, a graded InGaAs layer with {delta}-doping is inserted at the base-collector junction. The improved device has a peak current gain of 7 with ideal IV characteristics.

  10. Macromolecular Reaction Engineering Control of Bulk Propylene Polymerizations Operated with Multiple Catalysts through

    E-Print Network [OSTI]

    Skogestad, Sigurd

    Macromolecular Reaction Engineering Control of Bulk Propylene Polymerizations Operated: Control of Bulk Propylene Polymerizations Operated with Multiple Catalysts through Controller: Abstract: This article presents a model to describe the dynamic behavior of bulk propylene polymerizations

  11. Dark goo: Bulk viscosity as an alternative to dark energy

    E-Print Network [OSTI]

    Jean-Sebastien Gagnon; Julien Lesgourgues

    2011-09-16T23:59:59.000Z

    We present a simple (microscopic) model in which bulk viscosity plays a role in explaining the present acceleration of the universe. The effect of bulk viscosity on the Friedmann equations is to turn the pressure into an "effective" pressure containing the bulk viscosity. For a sufficiently large bulk viscosity, the effective pressure becomes negative and could mimic a dark energy equation of state. Our microscopic model includes self-interacting spin-zero particles (for which the bulk viscosity is known) that are added to the usual energy content of the universe. We study both background equations and linear perturbations in this model. We show that a dark energy behavior is obtained for reasonable values of the two parameters of the model (i.e. the mass and coupling of the spin-zero particles) and that linear perturbations are well-behaved. There is no apparent fine tuning involved. We also discuss the conditions under which hydrodynamics holds, in particular that the spin-zero particles must be in local equilibrium today for viscous effects to be important.

  12. Dark goo: Bulk viscosity as an alternative to dark energy

    E-Print Network [OSTI]

    Gagnon, Jean-Sebastien

    2011-01-01T23:59:59.000Z

    We present a simple (microscopic) model in which bulk viscosity plays a role in explaining the present acceleration of the universe. The effect of bulk viscosity on the Friedmann equations is to turn the pressure into an "effective" pressure containing the bulk viscosity. For a sufficiently large bulk viscosity, the effective pressure becomes negative and could mimic a dark energy equation of state. Our microscopic model includes self-interacting spin-zero particles (for which the bulk viscosity is known) that are added to the usual energy content of the universe. We study both background equations and linear perturbations in this model. We show that a dark energy behavior is obtained for reasonable values of the two parameters of the model (i.e. the mass and coupling of the spin-zero particles) and that linear perturbations are well-behaved. There is no apparent fine tuning involved. We also discuss the conditions under which hydrodynamics holds, in particular that the spin-zero particles must be in local eq...

  13. 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.

  14. 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.

  15. 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.

  16. Preparation of bulk superhard B-C-N nanocomposite compact

    DOE Patents [OSTI]

    Zhao, Yusheng (Los Alamos, NM); He, Duanwei (Sichuan, CN)

    2011-05-10T23:59:59.000Z

    Bulk, superhard, B--C--N nanocomposite compacts were prepared by ball milling a mixture of graphite and hexagonal boron nitride, encapsulating the ball-milled mixture at a pressure in a range of from about 15 GPa to about 25 GPa, and sintering the pressurized encapsulated ball-milled mixture at a temperature in a range of from about 1800-2500 K. The product bulk, superhard, nanocomposite compacts were well sintered compacts with nanocrystalline grains of at least one high-pressure phase of B--C--N surrounded by amorphous diamond-like carbon grain boundaries. The bulk compacts had a measured Vicker's hardness in a range of from about 41 GPa to about 68 GPa.

  17. Bulk Viscosity and Particle Creation in the Inflationary Cosmology

    E-Print Network [OSTI]

    Mehdi Eshaghi; Nematollah Riazi; Ahmad Kiasatpour

    2015-04-29T23:59:59.000Z

    We study particle creation in the presence of bulk viscosity of cosmic fluid in the early universe within the framework of open thermodynamical systems. Since the first-order theory of non-equilibrium thermodynamics is non-causal and unstable, we try to solve the bulk viscosity equation of the cosmic fluid with particle creation through the full causal theory. By adopting an appropriate function for particle creation rate of "Creation of Cold Dark Matter" model, we obtain analytical solutions which do not suffer from the initial singularity and are in agreement with equivalent solutions of Lambda-CDM model. We constrain the free parameter of particle creation in our model based on recent Planck data. It is also found that the inflationary solution is driven by bulk viscosity with or without particle creation.

  18. Bulk Viscosity, Decaying Dark Matter, and the Cosmic Acceleration

    E-Print Network [OSTI]

    James R. Wilson; Grant J. Mathews; George M. Fuller

    2006-09-25T23:59:59.000Z

    We discuss a cosmology in which cold dark-matter particles decay into relativistic particles. We argue that such decays could lead naturally to a bulk viscosity in the cosmic fluid. For decay lifetimes comparable to the present hubble age, this bulk viscosity enters the cosmic energy equation as an effective negative pressure. We investigate whether this negative pressure is of sufficient magnitude to account fo the observed cosmic acceleration. We show that a single decaying species in a flat, dark-matter dominated cosmology without a cosmological constant cannot reproduce the observed magnitude-redshift relation from Type Ia supernovae. However, a delayed bulk viscosity, possibly due to a cascade of decaying particles may be able to account for a significant fraction of the apparent cosmic acceleration. Possible candidate nonrelativistic particles for this scenario include sterile neutrinos or gauge-mediated decaying supersymmetric particles.

  19. Bulk Viscosity and Particle Creation in the Inflationary Cosmology

    E-Print Network [OSTI]

    Eshaghi, Mehdi; Kiasatpour, Ahmad

    2015-01-01T23:59:59.000Z

    We study particle creation in the presence of bulk viscosity of cosmic fluid in the early universe within the framework of open thermodynamical systems. Since the first-order theory of non-equilibrium thermodynamics is non-causal and unstable, we try to solve the bulk viscosity equation of the cosmic fluid with particle creation through the full causal theory. By adopting an appropriate function for particle creation rate of "Creation of Cold Dark Matter" model, we obtain analytical solutions which do not suffer from the initial singularity and are in agreement with equivalent solutions of Lambda-CDM model. We constrain the free parameter of particle creation in our model based on recent Planck data. It is also found that the inflationary solution is driven by bulk viscosity with or without particle creation.

  20. 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.

  1. 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.

  2. Bulk torsion fields in theories with large extra dimensions

    E-Print Network [OSTI]

    Biswarup Mukhopadhyaya; Somasri Sen; Soumitra SenGupta

    2002-04-25T23:59:59.000Z

    We study the consequences of spacetime torsion coexisting with gravity in the bulk in scenarios with large extra dimensions. Having linked torsion with the Kalb-Ramond antisymmetric tensor field arising in string theories, we examine its artifacts on the visible 3-brane when the extra dimensions are compactified. It is found that while torsion would have led to parity violation in a 4-dimensional framework, all parity violating effects disappear on the visible brane when the torsion originates in the bulk. However, such a scenario is found to have characteristics of its own, some of which can be phenomenologically significant.

  3. 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.

  4. Bulk viscosity of strongly coupled plasmas with holographic duals

    E-Print Network [OSTI]

    Steven S. Gubser; Silviu S. Pufu; Fabio D. Rocha

    2008-06-02T23:59:59.000Z

    We explain a method for computing the bulk viscosity of strongly coupled thermal plasmas dual to supergravity backgrounds supported by one scalar field. Whereas earlier investigations required the computation of the leading dissipative term in the dispersion relation for sound waves, our method requires only the leading frequency dependence of an appropriate Green's function in the low-frequency limit. With a scalar potential chosen to mimic the equation of state of QCD, we observe a slight violation of the lower bound on the ratio of the bulk and shear viscosities conjectured in arXiv:0708.3459.

  5. 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. Stefopoulos, Student Member, IEEE Abstract -- A framework of security-constrained adequacy evaluation (SCAE electric load while satisfying security constraints. It encompasses three main steps: (a) critical

  6. A phase space analysis for nonlinear bulk viscous cosmology

    E-Print Network [OSTI]

    Acquaviva, Giovanni

    2015-01-01T23:59:59.000Z

    We consider a Friedmann-Robertson-Walker spacetime filled with both viscous radiation and nonviscous dust. The former has a bulk viscosity which is proportional to an arbitrary power of the energy density, i.e. $\\zeta \\propto \\rho_v^{\

  7. A phase space analysis for nonlinear bulk viscous cosmology

    E-Print Network [OSTI]

    Giovanni Acquaviva; Aroonkumar Beesham

    2015-05-08T23:59:59.000Z

    We consider a Friedmann-Robertson-Walker spacetime filled with both viscous radiation and nonviscous dust. The former has a bulk viscosity which is proportional to an arbitrary power of the energy density, i.e. $\\zeta \\propto \\rho_v^{\

  8. 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.

  9. Computing hypersurfaces which minimize surface energy plus bulk energy

    E-Print Network [OSTI]

    Sullivan, John M.

    such energies is an important step in the definition of flat curvature flows [ATW]. By modifying the bulk energy this precise by working in the context of currents, as in [ATW] or [S].) Here, if S and S0 are contained

  10. BULK TITANIUM MICROFLUIDIC NETWORKS FOR PROTEIN SELF-ASSEMBLY STUDIES

    E-Print Network [OSTI]

    MacDonald, Noel C.

    BULK TITANIUM MICROFLUIDIC NETWORKS FOR PROTEIN SELF-ASSEMBLY STUDIES E.R. Parker1 , L.S. Hirst2 developed micromachining technique to fabricate microfluidic networks in thin titanium foils. These devices been integrated into the fabrication process in order to minimize protein adsorption to the titanium

  11. TECHNICAL POLLUTION PREVENTION GUIDE FOR DRY BULK TERMINALS

    E-Print Network [OSTI]

    Practices 24 4.4 4.5 Pollutants 26 4.4.1 Fugitive Dust 26 4.4.2 Commodity Spillage 27 4.4.3 Oil, lubricant#12;TECHNICAL POLLUTION PREVENTION GUIDE FOR DRY BULK TERMINALS IN THE LOWER FRASER BASIN DOE FRAP 1996-19 Prepared for: Enviromnent Canada Environmental Protection Fraser Pollution Abatement North

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Bulk from Bi-locals in Thermo Field CFT

    E-Print Network [OSTI]

    Jevicki, Antal

    2015-01-01T23:59:59.000Z

    We study the Large $N$ dynamics of the $O(N)$ field theory in the Thermo field approach. Concentrating on the singlet bi-local space within the systematic $1/N$ framework of collective field theory we discuss the emergent bulk space-time and construct the associated (Higher spin) fields. We note the presence of `evanescent' modes in this construction and also the mixing of spins at finite temperature.

  17. Bulk from Bi-locals in Thermo Field CFT

    E-Print Network [OSTI]

    Antal Jevicki; Junggi Yoon

    2015-03-29T23:59:59.000Z

    We study the Large $N$ dynamics of the $O(N)$ field theory in the Thermo field approach. Concentrating on the singlet bi-local space within the systematic $1/N$ framework of collective field theory we discuss the emergent bulk space-time and construct the associated (Higher spin) fields. We note the presence of `evanescent' modes in this construction and also the mixing of spins at finite temperature.

  18. Magnetization of 2-G Coils and Artificial Bulks

    E-Print Network [OSTI]

    Coombs, T. A.; Fagnard, J. F.; Matsuda, K.

    2014-06-27T23:59:59.000Z

    or bulks. ? Index Terms—HTS, racetrack, YBCO, magnetisation I. INTRODUCTION BCO has been available, in various forms, since shortly after the initial discovery of high temperature superconductors by Bednorz and Mueller. All forms of YBCO have... those available from conventional materials such as copper (wires) or NdFeB (magnetic field) there remain relatively few industrial applications and the barriers to widespread adoption remain high. Devices such as Fault Current Limiters, cables...

  19. Comment on "Accelerating cosmological expansion from shear and bulk viscosity"

    E-Print Network [OSTI]

    Giovannini, Massimo

    2015-01-01T23:59:59.000Z

    In a recent Letter [Phys. Rev. Lett. 114 091301 (2105)] the cause of the acceleration of the present Universe has been identified with the shear viscosity of an imperfect relativistic fluid even in the absence of any bulk viscous contribution. The gist of this comment is that the shear viscosity, if anything, can only lead to an accelerated expansion over sufficiently small scales well inside the Hubble radius.

  20. 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.

  1. EFFECTIVE POROSITY IMPLIES EFFECTIVE BULK DENSITY IN SORBING SOLUTE TRANSPORT

    SciTech Connect (OSTI)

    Flach, G.

    2012-02-27T23:59:59.000Z

    The concept of an effective porosity is widely used in solute transport modeling to account for the presence of a fraction of the medium that effectively does not influence solute migration, apart from taking up space. This non-participating volume or ineffective porosity plays the same role as the gas phase in single-phase liquid unsaturated transport: it increases pore velocity, which is useful towards reproducing observed solute travel times. The prevalent use of the effective porosity concept is reflected by its prominent inclusion in popular texts, e.g., de Marsily (1986), Fetter (1988, 1993) and Zheng and Bennett (2002). The purpose of this commentary is to point out that proper application of the concept for sorbing solutes requires more than simply reducing porosity while leaving other material properties unchanged. More specifically, effective porosity implies the corresponding need for an effective bulk density in a conventional single-porosity model. The reason is that the designated non-participating volume is composed of both solid and fluid phases, both of which must be neglected for consistency. Said another way, if solute does not enter the ineffective porosity then it also cannot contact the adjoining solid. Conceptually neglecting the fluid portion of the non-participating volume leads to a lower (effective) porosity. Likewise, discarding the solid portion of the non-participating volume inherently leads to a lower or effective bulk density. In the author's experience, practitioners virtually never adjust bulk density when adopting the effective porosity approach.

  2. 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...

  3. Dynamics of dendritic polymers in the bulk and under confinement

    SciTech Connect (OSTI)

    Chrissopoulou, K. [Foundation for Research and Technology-Hellas, Institute of Electronic Structure and Laser, P.O. Box 1527, 711 10, Heraklion Crete (Greece); Fotiadou, S. [Foundation for Research and Technology-Hellas, Institute of Electronic Structure and Laser, P.O. Box 1527, 711 10, Heraklion Crete, Greece and Aristotle University of Thessaloniki, Department of Chemical Engineering, Thessaloniki (Greece); Androulaki, K.; Anastasiadis, S. H. [Foundation for Research and Technology-Hellas, Institute of Electronic Structure and Laser, P.O. Box 1527, 711 10, Heraklion Crete, Greece and University of Crete, Department of Chemistry, Heraklion Crete (Greece); Tanis, I.; Karatasos, K. [Aristotle University of Thessaloniki, Department of Chemical Engineering, Thessaloniki (Greece); Prevosto, D.; Labardi, M. [CNR-IPCF, Department of Physics, University of Pisa, Pisa (Italy); Frick, B. [ILL-Institut Laue-Langevin, Grenoble (France)

    2014-05-15T23:59:59.000Z

    The structure and dynamics of a hyperbranched polyesteramide (Hybrane® S 1200) polymer and its nanocomposites with natural montmorillonite (Na{sup +}-MMT) are investigated by XRD, DSC, QENS, DS and Molecular Dynamics (MD) simulation. In bulk, the energy-resolved elastically scattered intensity from the polymer exhibits two relaxation steps, one attributed to sub-T{sub g} motions and one observed at temperatures above the glass transition, T{sub g}. The QENS spectra measured over the complete temperature range are consistent with the elastic measurements and can be correlated to the results emerging from the detailed description afforded by the atomistic simulations, which predict the existence of three relaxation processes. Moreover, dielectric spectroscopy shows the sub- T{sub g} beta process as well as the segmental relaxation. For the nanocomposites, XRD reveals an intercalated structure for all hybrids with distinct interlayer distances due to polymer chains residing within the galleries of the Na{sup +}-MMT. The polymer chains confined within the galleries show similarities in the behavior with that of the polymer in the bulk for temperatures below the bulk polymer T{sub g}, whereas they exhibit frozen dynamics under confinement at temperatures higher than that.

  4. 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.

  5. 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.

  6. 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.

  7. Improvement of electroluminescence performance by integration of ZnO nanowires and single-crystalline films on ZnO/GaN heterojunction

    SciTech Connect (OSTI)

    Shi, Zhifeng; Zhang, Yuantao, E-mail: zhangyt@jlu.edu.cn; Cui, Xijun; Wu, Bin; Zhuang, Shiwei; Yang, Fan; Zhang, Baolin; Du, Guotong [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, Qianjin Street 2699, Changchun 130012 (China); Yang, Xiaotian [School of Electrical and Electronic Information, Jilin Institute of Architecture and Civil Engineering, Changchun 130118 (China)

    2014-03-31T23:59:59.000Z

    Heterojunction light-emitting diodes based on n-ZnO nanowires/ZnO single-crystalline films/p-GaN structure have been demonstrated for an improved electroluminescence performance. A highly efficient ultraviolet emission was observed under forward bias. Compared with conventional n-ZnO/p-GaN structure, high internal quantum efficiency and light extraction efficiency were simultaneously considered in the proposed diode. In addition, the diode can work continuously for ?10?h with only a slight degradation in harsh environments, indicating its good reliability and application prospect in the future. This route opens possibilities for the development of advanced nanoscale devices in which the advantages of ZnO single-crystalline films and nanostructures can be integrated together.

  8. High external quantum efficiency and fill-factor InGaN/GaN heterojunction solar cells grown by NH{sub 3}-based molecular beam epitaxy

    SciTech Connect (OSTI)

    Lang, J. R.; Hurni, C. A.; Cruz, S. C.; Matioli, E.; Speck, J. S. [Department of Materials, University of California, Santa Barbara, California 93106 (United States); Neufeld, C. J.; Mishra, U. K. [Department of Electrical and Computer Engineering, University of California, Santa Barbara, California 93106 (United States)

    2011-03-28T23:59:59.000Z

    High external quantum efficiency (EQE) p-i-n heterojunction solar cells grown by NH{sub 3}-based molecular beam epitaxy are presented. EQE values including optical losses are greater than 50% with fill-factors over 72% when illuminated with a 1 sun AM0 spectrum. Optical absorption measurements in conjunction with EQE measurements indicate an internal quantum efficiency greater than 90% for the InGaN absorbing layer. By adjusting the thickness of the top p-type GaN window contact layer, it is shown that the short-wavelength (<365 nm) quantum efficiency is limited by the minority carrier diffusion length in highly Mg-doped p-GaN.

  9. Growth of GaN on Si(111): Surfaces and crystallinity of the epifilms and the transport behavior of GaN/Si heterojunctions

    SciTech Connect (OSTI)

    Xu Zhongjie; Xie Maohai [Physics Department, University of Hong Kong, Pokfulam Road (Hong Kong); Zhang Lixia; He Hongtao; Wang Jiannong [Physics Department, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2011-11-01T23:59:59.000Z

    Growths of GaN on Si(111) - (7 x 7) substrates by plasma-assisted molecular-beam epitaxy (PA-MBE) have been studied. Optimal conditions of MBE and the effect of a low-temperature (LT) buffer are followed. It is found that irrespective of the growth conditions and the growth strategies (direct versus two-step growth), a thin amorphous-like interface layer always forms. For smooth surfaces and better crystallinity of the epifilms, a LT-buffer preceding the high-temperature deposition is helpful, and the grown GaN films are of nitrogen-polar. Transport measurements of the heterojunctions of GaN on heavily p- and n-doped Si reveal ohmic behavior, whereas that of n-GaN on lightly doped n{sup -}-Si substrate shows rectifying characteristics.

  10. 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....

  11. 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...

  12. 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 ...

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

    E-Print Network [OSTI]

    San Andres, Luis

    2009-01-01T23:59:59.000Z

    Notes 10. THERMOHYDRODYNAMIC BULK-FLOW MODEL IN THIN FILM LUBRICATION ? Dr. Luis San Andr?s (2009) 1 Notes 10. Thermohydrodynamic Bulk-Flow Model in Thin Film Lubrication General flow characteristics in oil lubricated fluid film... regimes Notes 10. THERMOHYDRODYNAMIC BULK-FLOW MODEL IN THIN FILM LUBRICATION ? Dr. Luis San Andr?s (2009) 2 Bulk-Flow Equations for Thin Fluid Films The fluid flow within a thin film region, see Fig.1, is governed by the continuity...

  14. High temperature magnetic properties of SmCo5/-Fe(Co) bulk nanocomposite magnets

    E-Print Network [OSTI]

    Liu, J. Ping

    High temperature magnetic properties of SmCo5/-Fe(Co) bulk nanocomposite magnets Chuanbing Rong://apl.aip.org/about/rights_and_permissions #12;High temperature magnetic properties of SmCo5/a-Fe(Co) bulk nanocomposite magnets Chuanbing Rong,1 containing no heavy rare earths for power applications, SmCo5/Fe bulk nanocomposite magnets with enhanced

  15. 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

  16. Bulk viscosity of superfluid hyperon stars Mikhail E. Gusakov and Elena M. Kantor

    E-Print Network [OSTI]

    Bulk viscosity of superfluid hyperon stars Mikhail E. Gusakov and Elena M. Kantor Ioffe Physical; published 14 October 2008) We calculate the bulk viscosity due to nonequilibrium weak processes bulk viscosity coefficients, with only three of them being independent. In addition, we correct

  17. SINGLE-MASK, HIGH ASPECT RATIO, 3-D MICROMACHINING OF BULK TITANIUM , M. F. Aimi2

    E-Print Network [OSTI]

    MacDonald, Noel C.

    SINGLE-MASK, HIGH ASPECT RATIO, 3-D MICROMACHINING OF BULK TITANIUM M. P. Rao1 , M. F. Aimi2 , E. R profiles in bulk titanium. The method relies on the exploitation of Reactive Ion Etching Lag (RIE Lag for application in bulk micromachined titanium micromirror devices. 1. INTRODUCTION The recent development

  18. 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.

  19. Bulk effects in the coherent inelastic scattering of ultracold neutrons

    E-Print Network [OSTI]

    A. L. Barabanov; S. T. Belyaev

    2005-09-20T23:59:59.000Z

    With the use of theory developed earlier, bulk effects in ultracold neutron coherent inelastic scattering are considered both for solid and liquid target samples related to energy and momentum exchange with phonon and diffusion-like modes. For the neutron in a material trap, differential and integral probabilities for the energy transfer per bounce are presented in a simple analytic form which exhibits the parameter dependence. As an example, the theoretical values for the ultracold neutron loss rate from a storage bottle with Fomblin coated walls and stainless steel walls are evaluated. Possible contribution from incoherent inelastic scattering on hydrogen contamination is discussed.

  20. Elastic Moduli Inheritance and Weakest Link in Bulk Metallic Glasses

    SciTech Connect (OSTI)

    Stoica, Alexandru Dan [ORNL; Wang, Xun-Li [ORNL; Lu, Z.P. [University of Science and Technology, Beijing; Clausen, Bjorn [Los Alamos National Laboratory (LANL); Brown, Donald [Los Alamos National Laboratory (LANL)

    2012-01-01T23:59:59.000Z

    We show that a variety of bulk metallic glasses (BMGs) inherit their Young s modulus and shear modulus from the solvent components. This is attributed to preferential straining of locally solvent-rich configurations among tightly bonded atomic clusters, which constitute the weakest link in an amorphous structure. This aspect of inhomogeneous deformation, also revealed by our in-situ neutron diffraction studies of an elastically deformed BMG, suggests a scenario of rubber-like viscoelasticity owing to a hierarchy of atomic bonds in BMGs.

  1. Bulk viscosity in a plasma of confining gluons

    E-Print Network [OSTI]

    Wojciech Florkowski; Radoslaw Ryblewski; Nan Su; Konrad Tywoniuk

    2015-04-13T23:59:59.000Z

    We investigate dynamic properties of a plasma whose constituents are confining gluons resulting from the Gribov quantization. In a static formulation, this system reproduces qualitatively the pure-glue equation of state and thereby encodes crucial features of the phase transition. The dynamic description proposed in this work allows us to study non-equilibrium transport phenomena with the inclusion of confinement effects. In particular, we determine the non-equilibrium behaviour of the interaction measure (trace anomaly) and find the form of the bulk viscosity coefficient. The latter may be used in phenomenological applications to heavy-ion collisions.

  2. Bulk Viscosity of a Gas of Massless Pions

    E-Print Network [OSTI]

    Jiunn-Wei Chen; Juven Wang

    2009-03-31T23:59:59.000Z

    In the hadronic phase, the dominant configuration of QCD with two flavors of massless quarks is a gas of massless pions. We calculate the bulk viscosity (zeta) using the Boltzmann equation with the kinetic theory generalized to incorporate the trace anomaly. We find that the dimensionless ratio zeta/s, s being the entropy density, is monotonic increasing below T=120 MeV, where chiral perturbation theory is applicable. This, combined with previous results, shows that zeta/s reaches its maximum near the phase transition temperature Tc, while eta/s, eta being the shear viscosity, reaches its minimum near Tc in QCD with massless quarks.

  3. Bulk viscosity in a plasma of confining gluons

    E-Print Network [OSTI]

    Florkowski, Wojciech; Su, Nan; Tywoniuk, Konrad

    2015-01-01T23:59:59.000Z

    We investigate dynamic properties of a plasma whose constituents are confining gluons resulting from the Gribov quantization. In a static formulation, this system reproduces qualitatively the pure-glue equation of state and thereby encodes crucial features of the phase transition. The dynamic description proposed in this work allows us to study non-equilibrium transport phenomena with the inclusion of confinement effects. In particular, we determine the non-equilibrium behaviour of the interaction measure (trace anomaly) and find the form of the bulk viscosity coefficient. The latter may be used in phenomenological applications to heavy-ion collisions.

  4. Non-Brownian molecular self-diffusion in bulk water

    E-Print Network [OSTI]

    Janez Stepišnik; Aleš Mohori?; Igor Serša

    2010-10-06T23:59:59.000Z

    The paper presents the velocity autocorrelation spectrum of bulk water measured by a new technique of NMR modulated gradient spin echo method. This technique is unprecedented for the spectrum measurement in the frequency interval between a few Hz to about 100 kHz with respect to directness and clarity of results and shows that a simple model of Brownian self-diffusion is not applicable to describe the diffusion dynamics of water molecules. The observed temperature dependant spectra of water show the existence of a slow chain-like dynamics in water, which we explain by coupling of diffusing molecule to broken bonds in the hydrogen bond network.

  5. 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.

  6. Federal Bulk Transmission Regulatory Roadmapping | OpenEI Community

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model,DOEHazelPennsylvania:57427°, -89.4742177° Show Map LoadingFayston,Federal Bulk

  7. Robbins Corn & Bulk Services | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-f < RAPID‎ |Rippey Jump to: navigation, searchRobbins Corn & Bulk

  8. The detection of bulk explosives using nuclear-based techniques

    SciTech Connect (OSTI)

    Morgado, R.E.; Gozani, T.; Seher, C.C.

    1988-01-01T23:59:59.000Z

    In 1986 we presented a rationale for the detection of bulk explosives based on nuclear techniques that addressed the requirements of civil aviation security in the airport environment. Since then, efforts have intensified to implement a system based on thermal neutron activation (TNA), with new work developing in fast neutron and energetic photon reactions. In this paper we will describe these techniques and present new results from laboratory and airport testing. Based on preliminary results, we contended in our earlier paper that nuclear-based techniques did provide sufficiently penetrating probes and distinguishable detectable reaction products to achieve the FAA operational goals; new data have supported this contention. The status of nuclear-based techniques for the detection of bulk explosives presently under investigation by the US Federal Aviation Administration (FAA) is reviewed. These include thermal neutron activation (TNA), fast neutron activation (FNA), the associated particle technique, nuclear resonance absorption, and photoneutron activation. The results of comprehensive airport testing of the TNA system performed during 1987-88 are summarized. From a technical point of view, nuclear-based techniques now represent the most comprehensive and feasible approach for meeting the operational criteria of detection, false alarms, and throughput. 9 refs., 5 figs., 2 tabs.

  9. Corrosion of Metal Inclusions In Bulk Vitrification Waste Packages

    SciTech Connect (OSTI)

    Bacon, Diana H.; Pierce, Eric M.; Wellman, Dawn M.; Strachan, Denis M.; Josephson, Gary B.

    2006-07-31T23:59:59.000Z

    The primary purpose of the work reported here is to analyze the potential effect of the release of technetium (Tc) from metal inclusions in bulk vitrification waste packages once they are placed in the Integrated Disposal Facility (IDF). As part of the strategy for immobilizing waste from the underground tanks at Hanford, selected wastes will be immobilized using bulk vitrification. During analyses of the glass produced in engineering-scale tests, metal inclusions were found in the glass product. This report contains the results from experiments designed to quantify the corrosion rates of metal inclusions found in the glass product from AMEC Test ES-32B and simulations designed to compare the rate of Tc release from the metal inclusions to the release of Tc from glass produced with the bulk vitrification process. In the simulations, the Tc in the metal inclusions was assumed to be released congruently during metal corrosion as soluble TcO4-. The experimental results and modeling calculations show that the metal corrosion rate will, under all conceivable conditions at the IDF, be dominated by the presence of the passivating layer and corrosion products on the metal particles. As a result, the release of Tc from the metal particles at the surfaces of fractures in the glass releases at a rate similar to the Tc present as a soluble salt. The release of the remaining Tc in the metal is controlled by the dissolution of the glass matrix. To summarize, the release of 99Tc from the BV glass within precipitated Fe is directly proportional to the diameter of the Fe particles and to the amount of precipitated Fe. However, the main contribution to the Tc release from the iron particles is over the same time period as the release of the soluble Tc salt. For the base case used in this study (0.48 mass% of 0.5 mm diameter metal particles homogeneously distributed in the BV glass), the release of 99Tc from the metal is approximately the same as the release from 0.3 mass% soluble Tc salt in the castable refractory block and it is released over the same time period as the salt. Therefore, to limit the impact of precipitated Fe on the release of 99Tc, both the amount of precipitated Fe in the BV glass and the diameter of these particles should be minimized.

  10. 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.

  11. 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.

  12. Randall-Sundrum scenario with bulk dilaton and torsion

    SciTech Connect (OSTI)

    Mukhopadhyaya, Biswarup; Sen, Somasri; SenGupta, Soumitra [Regional Centre for Accelerator-based Particle Physics, Harish-Chandra Research Institute, Chhatnag Road, Jhusi, Allahabad - 211 019 (India); Centre for Theoretical Physics, Jamia Millia Islamia, New Delhi 110 025 (India); Department of Theoretical Physics, Indian Association for the Cultivation of Science, Kolkata - 700 032 (India)

    2009-06-15T23:59:59.000Z

    We consider a string-inspired torsion-dilaton-gravity action in a Randall-Sundrum braneworld scenario and show that, in an effective four-dimensional theory on the visible brane, the rank-2 antisymmetric Kalb-Ramond field (source of torsion) is exponentially suppressed. The result is similar to our earlier result in [B. Mukhopadhyaya, S. Sen, and S. SenGupta, Phys. Rev. Lett. 89, 121101 (2002); Phys. Rev. Lett. 89, 259902(E) (2002)], where no dilaton was present in the bulk. This offers an explanation of the apparent invisibility of torsion in our space-time. However, in this case the trilinear couplings {approx}TeV{sup -1} between the dilaton and torsion may lead to new signals in TeV-scale experiments, bearing the stamp of extra warped dimensions.

  13. Methods of synthesizing hydroxyapatite powders and bulk materials

    DOE Patents [OSTI]

    Luo, P.

    1999-01-12T23:59:59.000Z

    Methods are provided for producing non-porous controlled morphology hydroxyapatite granules of less than 8 {micro}m by a spray-drying process. Solid or hollow spheres or doughnuts can be formed by controlling the volume fraction and viscosity of the slurry as well as the spray-drying conditions. Methods of providing for homogeneous cellular structure hydroxyapatite granules are also provided. Pores or channels or varying size and number can be formed by varying the temperature at which a hydroxyapatite slurry formed in basic, saturated ammonium hydroxide is spray-dried. Methods of providing non-porous controlled morphology hydroxyapatite granules in ammonium hydroxide are also provided. The hydroxyapatite granules and bulk materials formed by these methods are also provided. 26 figs.

  14. Methods of synthesizing hydroxyapatite powders and bulk materials

    DOE Patents [OSTI]

    Luo, Ping (2843A Forest Ave., Berkeley, CA 94705)

    1999-01-12T23:59:59.000Z

    Methods are provided for producing non-porous controlled morphology hydroxyapatite granules of less than 8 .mu.m by a spray-drying process. Solid or hollow spheres or doughnuts can be formed by controlling the volume fraction and viscosity of the slurry as well as the spray-drying conditions. Methods of providing for homogenous cellular structure hydroxyapatite granules are also provided. Pores or channels or varying size and number can be formed by varying the temperature at which a hydroxyapatite slurry formed in basic, saturated ammonium hydroxide is spray-dried. Methods of providing non-porous controlled morphology hydroxyapatite granules in ammonium hydroxide are also provided. The hydroxyapatite granules and bulk materials formed by these methods are also provided.

  15. Derivations and Observations of Prominence Bulk Motions and Mass

    E-Print Network [OSTI]

    Kucera, T A

    2015-01-01T23:59:59.000Z

    In this chapter we review observations and techniques for measuring both bulk flows in prominences and prominence mass. Measuring these quantities is essential to development and testing of models discussed throughout this book. Prominence flows are complex and various, ranging from the relatively linear flows along prominence spines to the complex, turbulent patterns exhibited by hedgerow prominences. Techniques for measuring flows include time slice and optical flow techniques used for motions in the plane of the sky and the use of spectral line profiles to determine Doppler velocities along the line of sight. Prominence mass measurement is chiefly done via continuum absorption measurements, but mass has also been estimated using cloud modeling and white light measurements.

  16. 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.

  17. Feed Variability and Bulk Vitrification Glass Performance Assessment

    SciTech Connect (OSTI)

    Mahoney, Lenna A.; Vienna, John D.

    2005-01-10T23:59:59.000Z

    The supplemental treatment (ST) bulk vitrification process will obtain its feed, consisting of low-activity waste (LAW), from more than one source. One purpose of this letter report is to describe the compositional variability of the feed to ST. The other is to support the M-62-08 decision by providing a preliminary assessment of the effectiveness of bulk vitrification (BV), the process that has been selected to perform supplemental treatment, in handling the ST feed envelope. Roughly nine-tenths of the ST LAW feed will come from the Waste Treatment Plant (WTP) pretreatment. This processed waste is expected to combine (1) a portion of the same LAW feed sent to the WTP melters and (2) a dilute stream that is the product of the condensate from the submerged-bed scrubber (SBS) and the drainage from the electrostatic precipitator (WESP), both of which are part of the LAW off-gas system. The manner in which the off-gas-product stream is concentrated to reduce its volume, and the way in which the excess LAW and off-gas product streams are combined, are part of the interface between WTP and ST and have not been determined. This letter report considers only one possible arrangement, in which half of the total LAW is added to the off-gas product stream, giving an estimated ST feed stream from WTP. (Total LAW equals that portion of LAW sent to the WTP LAW vitrification plant (WTP LAW) plus the LAW not currently treatable in the LAW vitrification plant due to capacity limitations (excess)).

  18. 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.

  19. Bulk viscosity of strange matter and r-modes in neutron stars

    E-Print Network [OSTI]

    Debarati Chatterjee; Debades Bandyopadhyay

    2008-12-30T23:59:59.000Z

    We discuss bulk viscosity due to non-leptonic processes involving hyperons and Bose-Einstein condensate of negatively charged kaons in neutron stars. It is noted that the hyperon bulk viscosity coefficient is a few order of magnitude larger than that of the case with the condensate. Further it is found that the hyperon bulk viscosity is suppressed in a superconducting phase. The hyperon bulk viscosity efficiently damps the r-mode instability in neutron stars irrespective of whether a superconducting phase is present or not in neutron star interior.

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

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

    before and after cycling using synchrotron X-ray diffraction and transmission X-ray absorption spectroscopy. Correlating surface chemistry and bulk structure information with...

  1. 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.

  2. 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.

  3. Gas bulk motion in the Perseus cluster measured with SUZAKU

    E-Print Network [OSTI]

    Tamura, Takayuki; Iizuka, R; Fukazawa, Y; Hayashida, K; Ueda, S; Matsushita, K; Sato, K; Nakazawa, K; Ota, N; Takizawa, M

    2013-01-01T23:59:59.000Z

    We present the results from Suzaku observations of the Perseus galaxy cluster, which is relatively close, the brightest in the X-ray sky and a relaxed object with a cool core. A number of exposures of central regions and offset pointing with the X-ray Imaging Spectrometer cover a region within radii of 20'-30'. The central data are used to evaluate the instrumental energy-scale calibration with accuracy confirmed to within around 300 km/s, by the spatial and temporal variation of the instruments. These deep and well-calibrated data are used to measure X-ray redshifts of the intracluster medium. A hint of gas bulk motion, with radial velocity of about -(150-300) km/s, relative to the main system was found at 2-4 arcmin (45-90kpc) west of the cluster center, where an X-ray excess and a cold front were found previously. No other velocity structure was discovered. Over spatial scales of 50-100kpc and within 200kpc radii of the center, the gas-radial-velocity variation is below 300 km/s, while over scales of 400 k...

  4. Magnetic and magnetocaloric properties of bulk dysprosium chromite

    SciTech Connect (OSTI)

    McDannald, A. [Material Science and Engineering, University of Connecticut, Storrs, Connecticut 06269 (United States) [Material Science and Engineering, University of Connecticut, Storrs, Connecticut 06269 (United States); Institute of Material Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Kuna, L. [Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)] [Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States); Jain, M. [Institute of Material Science, University of Connecticut, Storrs, Connecticut 06269 (United States) [Institute of Material Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Department of Physics, University of Connecticut, Storrs, Connecticut 06269 (United States)

    2013-09-21T23:59:59.000Z

    In this work, a polycrystalline bulk DyCrO{sub 3} sample was prepared by a solution route and the structural and magnetic properties were investigated. The phase purity and ionic valence state of the DyCrO{sub 3} sample were determined by x-ray diffraction/Raman spectroscopy and x-ray photoelectron spectroscopy, respectively. The AC and DC magnetization measurements revealed the onset of antiferromagnetic order at 146 K with an effective moment of 8.88 ?{sub B}. Isothermal magnetization measurements of this material are presented for the first time, showing a peak in the coercive field at 80 K that is explained by the competition between the paramagnetic Dy{sup 3+} and Cr{sup 3+} sublattices. DyCrO{sub 3} was found to display a large magnetocaloric effect (8.4 J/kg K) and relative cooling power (217 J/kg) at 4 T applied field, which renders DyCrO{sub 3} useful for magnetic refrigeration between 5 K and 30 K.

  5. 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.

  6. 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

  7. 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

  8. UNCORRECTED 2 Spall strength of a zirconium-based bulk metallic glass under

    E-Print Network [OSTI]

    Rollins, Andrew M.

    of Mechanical and Aerospace Engineering, Case Western Reserve University, 10900 Euclid Avenue, Glennan 616 B. Introduction 40 Bulk amorphous metals, also referred to as bulk metallic 41 glasses (BMG), are alloys in which super-cooling of a liquid 42 alloy produces a metastable phase, thus preventing forma- 43 tion

  9. Applications of Irreversible Thermodynamics: Bulk and Interfacial Electronic, Ionic, Magnetic, and Thermal Transport

    E-Print Network [OSTI]

    Sears, Matthew

    2012-10-19T23:59:59.000Z

    : : : : : : : : : 7 A. Single Carrier Systems . . . . . . . . . . . . . . . . . . . . 9 1. Rate of Entropy Production . . . . . . . . . . . . . . . 9 2. Bulk Fluxes and Rate of Entropy Production . . . . . 11 3. Distinguishing Heating from Entropy Production... . . . . . . . . . . . . . . . . . 16 1. Rate of Entropy Production . . . . . . . . . . . . . . . 18 2. Bulk Fluxes and Rate of Entropy Production . . . . . 19 3. Surface Rate of Entropy Production . . . . . . . . . . 21 4. Surface Fluxes and Rate of Entropy Production . . . . 23...

  10. Bulk, surface and corner free energy series for the chromatic polynomial on the square and triangular

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Bulk, surface and corner free energy series for the chromatic polynomial on the square, surface and corner free energies of the chromatic polynomial. This extends the existing series expression for the bulk free energy (to order q-40 ), and we are able to conjecture exact product formulae

  11. 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

  12. Proton transfer from the bulk to the bound ubiquinone QB of the reaction center in

    E-Print Network [OSTI]

    Steinhoff, Heinz-Jürgen

    Proton transfer from the bulk to the bound ubiquinone QB of the reaction center in chromatophores, 1999) The mechanism of proton transfer from the bulk into the mem- brane protein interior was studied is accompanied by proton trapping. We used kinetic spec- troscopy to measure (i) the electron transfer to QB (at

  13. Sub-100 ps bulk-recombination-limited InP:Fe photoconductive detector

    SciTech Connect (OSTI)

    Hammond, R.B.; Paulter, N.G.; Iverson, A.E.; Smith, R.C.

    1981-01-01T23:59:59.000Z

    Both surface and bulk excited semi-insulating InP optoelectronic switches were studied. It was found that transient recombination in these devices is the same for both types of excitation. It is concluded that the recombination is a bulk controlled process.

  14. POLYMER PROGRAM SEMINAR "Structure at the surface and in the bulk in biomaterials

    E-Print Network [OSTI]

    Alpay, S. Pamir

    POLYMER PROGRAM SEMINAR "Structure at the surface and in the bulk in biomaterials: Studies for investigating the surface and the bulk structure in biomaterials will be presented. Formation of thin polymer films on aqueous surfaces, and the adsorption of proteins onto polymer surfaces in the aqueous media

  15. 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...

  16. Bulk ion acceleration and particle heating during magnetic reconnection in a laboratory plasmaa)

    E-Print Network [OSTI]

    Ji, Hantao

    Bulk ion acceleration and particle heating during magnetic reconnection in a laboratory plasmaa January 2014; accepted 20 February 2014; published online 7 May 2014) Bulk ion acceleration and particle-plane (Hall) electric field plays a key role in ion heating and acceleration. The electrostatic potential

  17. 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

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

    E-Print Network [OSTI]

    equipment, maintenance, reliability, risk, security, optimization 1.Introduction Maintenance of bulk Equipment Yong Jiang, Ming Ni, James D. McCalley, Tim Van Voorhis {jiangy for bulk transmission equipment that is based on the cumulative long-term risk caused by each piece

  19. 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.

  20. 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

  1. 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.

  2. Bulk viscosity-driven suppression of shear viscosity effects on the flow harmonics at RHIC

    E-Print Network [OSTI]

    J. Noronha-Hostler; J. Noronha; F. Grassi

    2014-06-19T23:59:59.000Z

    The interplay between shear and bulk viscosities on the flow harmonics, $v_n$'s, at RHIC is investigated using the newly developed relativistic 2+1 hydrodynamical code v-USPhydro that includes bulk and shear viscosity effects both in the hydrodynamic evolution and also at freeze-out. While shear viscosity is known to attenuate the flow harmonics, we find that the inclusion of bulk viscosity decreases the shear viscosity-induced suppression of the flow harmonics bringing them closer to their values in ideal hydrodynamical calculations. Depending on the value of the bulk viscosity to entropy density ratio, $\\zeta/s$, in the quark-gluon plasma, the bulk viscosity-driven suppression of shear viscosity effects on the flow harmonics may require a re-evaluation of the previous estimates of the shear viscosity to entropy density ratio, $\\eta/s$, of the quark-gluon plasma previously extracted by comparing hydrodynamic calculations to heavy ion data.

  3. 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.

  4. Bulk superhard B-C-N nanocomposite compact and method for preparing thereof

    DOE Patents [OSTI]

    Zhao, Yusheng; He, Duanwei

    2004-07-06T23:59:59.000Z

    Bulk, superhard, B-C-N nanocomposite compact and method for preparing thereof. The bulk, superhard, nanocomposite compact is a well-sintered compact and includes nanocrystalline grains of at least one high-pressure phase of B-C-N surrounded by amorphous diamond-like carbon grain boundaries. The bulk compact has a Vicker's hardness of about 41-68 GPa. It is prepared by ball milling a mixture of graphite and hexagonal boron nitride, encapsulating the ball-milled mixture, and sintering the encapsulated ball-milled mixture at a pressure of about 5-25 GPa and at a temperature of about 1000-2500 K.

  5. Chemical, electronic, and magnetic structure of LaFeCoSi alloy: Surface and bulk properties

    SciTech Connect (OSTI)

    Lollobrigida, V. [Dipartimento di Scienze, Università Roma Tre, I-00146 Rome (Italy); Dipartimento di Matematica e Fisica, Università Roma Tre, I-00146 Rome (Italy); Basso, V.; Kuepferling, M.; Coïsson, M.; Olivetti, E. S.; Celegato, F. [Istituto Nazionale di Ricerca Metrologica (INRIM), I-10135 Torino (Italy); Borgatti, F. [CNR, Istituto per lo Studio dei Materiali Nanostrutturati (ISMN), I-40129 Bologna (Italy); Torelli, P.; Panaccione, G. [CNR, Istituto Officina dei Materiali (IOM), Lab. TASC, I-34149 Trieste (Italy); Tortora, L. [Laboratorio di Analisi di Superficie, Dipartimento di Matematica e Fisica, Università Roma Tre, I-00146 Rome (Italy); Dipartimento di Ingegneria Meccanica, Università Tor Vergata, I-00133 Rome (Italy); Stefani, G.; Offi, F. [Dipartimento di Scienze, Università Roma Tre, I-00146 Rome (Italy)

    2014-05-28T23:59:59.000Z

    We investigate the chemical, electronic, and magnetic structure of the magnetocaloric LaFeCoSi compound with bulk and surface sensitive techniques. We put in evidence that the surface retains a soft ferromagnetic behavior at temperatures higher than the Curie temperature of the bulk due to the presence of Fe clusters at the surface only. This peculiar magnetic surface effect is attributed to the exchange interaction between the ferromagnetic Fe clusters located at the surface and the bulk magnetocaloric alloy, and it is used here to monitor the magnetic properties of the alloy itself.

  6. 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.

  7. Anisotropic elastic scattering of stripe/line-shaped scatters to two-dimensional electron gas: Model and illustrations in a nonpolar AlGaN/GaN hetero-junction

    SciTech Connect (OSTI)

    Zhang, Jinfeng, E-mail: jfzhang@xidian.edu.cn; Li, Yao; Yan, Ran; Nie, Yuhu; Zhang, Jincheng; Hao, Yue, E-mail: yhao@xidian.edu.cn [State Key Discipline Laboratory of Wide Bandgap Semiconductor Technologies, School of Microelectronics, Xidian University, Xi'an 710071 (China); Liu, Guipeng [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, P.O. Box 912, Beijing 100083 (China)

    2014-09-07T23:59:59.000Z

    In a semiconductor hetero-junction, the stripe/line-shaped scatters located at the hetero-interface lead to the anisotropic transport of two-dimensional electron gas (2DEG). The elastic scattering of infinitely long and uniform stripe/line-shaped scatters to 2DEG is theoretically investigated based on a general theory of anisotropic 2DEG transport [J. Schliemann and D. Loss, Phys. Rev. B 68(16), 165311 (2003)], and the resulting 2DEG mobility along the applied electrical field is modeled to be a function of the angle between the field and the scatters. The anisotropy of the scattering and the mobility originate in essence from that the stripe/line-shaped scatters act upon the injecting two-dimensional wave vector by changing only its component perpendicular to the scatters. Three related scattering mechanisms in a nonpolar AlGaN/GaN hetero-junction are discussed as illustrations, including the striated morphology caused interface roughness scattering, and the polarization induced line charge dipole scattering and the misfit dislocation scattering at the AlGaN/GaN interface. Different anisotropic behaviors of the mobility limited by these scattering mechanisms are demonstrated, but analysis shows that all of them are determined by the combined effects of the anisotropic bare scattering potential and the anisotropic dielectric response of the 2DEG.

  8. Low-threshold pulsed and cw InGaAsP/InGaP/GaAs double-heterojunction lasers emitting visible radiation in the 0. 73--0. 79. mu. range (T = 300 K, I/sub th/ = 3. 5--1. 3 kA/cm/sup 2/)

    SciTech Connect (OSTI)

    Alferov, Z.I.; Arsent'ev, I.N.; Vavilova, L.S.; Garbuzov, D.Z.; Tulashvili, V.

    1984-01-01T23:59:59.000Z

    The results of further investigations intended to construct InGaAsP/GaAs double-heterojunction structures with a much lower threshold current density and to achieve cw lasing at 300 K in stripe InGaAsP/GaAs lasers at 0.73--0.79 ..mu.. are reported. (AIP)

  9. 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

  10. 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

  11. 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

  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. 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 ...

  14. 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 ...

  15. Calibration of DEM models for granular materials using bulk physical tests 

    E-Print Network [OSTI]

    Johnstone, Mical William

    2010-01-01T23:59:59.000Z

    , when validation studies are conducted, discrepancies between bulk responses in physical tests and numerical predictions using measured particles properties may arise. The aire of this research is to develop a methodology to calibrate DEM models...

  16. 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...

  17. 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 ...

  18. Effect of Annealing on Hardness and the Modulus of Elasticity in Bulk Nanocrystalline Nickel

    E-Print Network [OSTI]

    Torrents, Anna; Yang, Heather; Mohamed, Farghalli A.

    2010-01-01T23:59:59.000Z

    in Bulk Nanocrystalline Nickel ANNA TORRENTS, HEATHER YANG,Composition of (ED) nc-Nickel P S Cu Co B Ni balance 622—for monocrys- talline nickel at ambient temperature (S 11 =

  19. Microyielding of Core-Shell Crystal Dendrites in a Bulk-metallic-glass Matrix Composite

    E-Print Network [OSTI]

    Huang, E-Wen

    In-situ synchrotron x-ray experiments have been used to follow the evolution of the diffraction peaks for crystalline dendrites embedded in a bulk metallic glass matrix subjected to a compressive loading-unloading cycle. ...

  20. 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.

  1. 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

  2. Petrology and bulk chemistry of Yamato-82094, a new type of carbonaceous chondrite

    E-Print Network [OSTI]

    Brest, Université de

    Petrology and bulk chemistry of Yamato-82094, a new type of carbonaceous chondrite M. KIMURA1-rich metal in the chondrules indicate that Y-82094 is petrologic type 3.2. The extremely low abundance

  3. Suppression of structural imperfection in strained Si by utilizing SiGe bulk substrate

    SciTech Connect (OSTI)

    Usami, N.; Nose, Y.; Fujiwara, K.; Nakajima, K. [Institute for Materials Research (IMR), Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan)

    2006-05-29T23:59:59.000Z

    We attempted to utilize homemade SiGe bulk crystal as a substrate for epitaxy of strain-controlled heterostructures. X-ray reciprocal space mapping clarified that the growth of a Si thin film on a SiGe bulk substrate leads to reduction in the orientation fluctuation compared with that on a SiGe virtual substrate. Furthermore, analysis of Raman spectra revealed a dramatic decrease of the strain fluctuation in the strained Si film on the SiGe bulk substrate. These results suggest that the SiGe bulk crystal can be utilized as a substrate for various strain-controlled heterostructures for fundamental studies as well as improvement of device performance.

  4. 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

    into a conceptual model is needed to analyze and describe bulk buying behavior. Literature from the third group was used to: 1) help identify, guide, and evaluate the need for mar- ket information on factors most likely to affect bulk buyers' re... be described by three characteristics: 1) the newness of the buying problem; 2) information requirements of the buy- ing decision makers; and 3) new alternatives given serious considera- tion by decision makers. These factors determine buyer's needs from...

  5. 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.

  6. 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

  7. Comparing matched polymer:Fullerene solar cells made by solution-sequential processing and traditional blend casting: Nanoscale structure and device performance

    E-Print Network [OSTI]

    2014-01-01T23:59:59.000Z

    Bulk Heterojunction Solar Cells. J. Phys. Chem. C 2014, 118,Polythiophene:Fullerene Solar Cells. Phys. Rev. B 2008, 78,Polymer: Fullerene Solar Cells Using the External Quantum

  8. 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

  9. The terminal bulk Lorentz factor of relativistic electron-positron jets

    E-Print Network [OSTI]

    N. Renaud; G. Henri

    1998-04-17T23:59:59.000Z

    We present numerical simulation of bulk Lorentz factor of relativistic electron-positron jet driven by Compton rocket effect from accretion disc radiation. The plasma is assumed to have a power-law distribution $n_{e}(\\gamma) \\propto \\gamma^{-s}$ whith $1 terminal bulk Lorentz factor in the case of supermassive black holes relevant to AGN and stellar black holes relevant to galactic microquasars. In the latter case, Klein-Nishina cross section effect are more important, and induce terminal bulk Lorentz factor smaller than in the former case. Our result are in good agreement with bulk Lorentz factors observed in galactic sources (GRS1915+105, GROJ1655-40) and extragalactic ones. Differences in scattered radiation and acceleration mechanism efficiency in AGN environment can be responsible for the variety of relativistic motion in those objects. We also take into account the influence of the size of the accretion disc; if the external radius is small enough, the bulk Lorentz factor can be as high as 60.

  10. The terminal bulk Lorentz factor of relativistic electron-positron jet

    E-Print Network [OSTI]

    N. Renaud; G. Henri

    1997-06-16T23:59:59.000Z

    We present numerical simulation of bulk Lorentz factor of relativistic electron positron jet driven by Compton rocket effect from accretion disk radiation. The plasma is assumed to have a power-law energy distribution and is continuously reheated to compensate for radiation losses. We include Klein-Nishina (hereafter KN) corrections, and study the role of energy upper cut-off, spectral index, and source compactness. We determine terminal bulk Lorentz factor in the case of supermassive black holes relevant to AGN and stellar black holes relevant to galactic microquasars. In the latter case, effects of KN corrections are more important and induce terminal bulk Lorentz factor smaller than in the former case. The result can explain the low bulk Lorentz factors for galactic sources (GRS1915+105, GROJ1655-40) compared to extragalactic ones. We also take into account the influence of the size of the accretion disk; if the external radius is small enough, the bulk Lorentz factor can be as high as 60, which is comparable to the values needed to explain extragalactic gamma-ray bursts.

  11. Thermal conductivity of bulk and nanowire Mg?SixSn1–x alloys from first principles

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

    Li, Wu; Lindsay, L.; Broido, D. A.; Stewart, Derek A.; Mingo, Natalio

    2012-11-01T23:59:59.000Z

    The lattice thermal conductivity (?) of the thermoelectric materials, Mg?Si, Mg?Sn, and their alloys, are calculated for bulk and nanowires, without adjustable parameters. We find good agreement with bulk experimental results. For large nanowire diameters, size effects are stronger for the alloy than for the pure compounds. For example, in 200 nm diameter nanowires ? is lower than its bulk value by 30%, 20%, and 20% for Mg?Si?.?Sn?.?, Mg?Si, and Mg?Sn, respectively. For nanowires less than 20 nm thick, the relative decrease surpasses 50%, and it becomes larger in the pure compounds than in the alloy. At room temperature, ? of Mg?SixSn1–x is less sensitive to nanostructuring size effects than SixGe1–x, but more sensitive than PbTexSe1–x. This suggests that further improvement of Mg?SixSn1–x as a nontoxic thermoelectric may be possible.

  12. Thermal conductivity of bulk and nanowire Mg?SixSn1–x alloys from first principles

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

    Li, Wu; Lindsay, L.; Broido, D. A.; Stewart, Derek A.; Mingo, Natalio

    2012-11-01T23:59:59.000Z

    The lattice thermal conductivity (?) of the thermoelectric materials, Mg?Si, Mg?Sn, and their alloys, are calculated for bulk and nanowires, without adjustable parameters. We find good agreement with bulk experimental results. For large nanowire diameters, size effects are stronger for the alloy than for the pure compounds. For example, in 200 nm diameter nanowires ? is lower than its bulk value by 30%, 20%, and 20% for Mg?Si?.?Sn?.?, Mg?Si, and Mg?Sn, respectively. For nanowires less than 20 nm thick, the relative decrease surpasses 50%, and it becomes larger in the pure compounds than in the alloy. At room temperature, ?more »of Mg?SixSn1–x is less sensitive to nanostructuring size effects than SixGe1–x, but more sensitive than PbTexSe1–x. This suggests that further improvement of Mg?SixSn1–x as a nontoxic thermoelectric may be possible.« less

  13. Boiling of the Interface between Two Immiscible Liquids below the Bulk Boiling Temperatures of Both Components

    E-Print Network [OSTI]

    Anastasiya V. Pimenova; Denis S. Goldobin

    2014-10-20T23:59:59.000Z

    We consider the problem of boiling of the direct contact of two immiscible liquids. An intense vapour formation at such a direct contact is possible below the bulk boiling points of both components, meaning an effective decrease of the boiling temperature of the system. Although the phenomenon is known in science and widely employed in technology, the direct contact boiling process was thoroughly studied (both experimentally and theoretically) only for the case where one of liquids is becoming heated above its bulk boiling point. On the contrary, we address the case where both liquids remain below their bulk boiling points. In this paper we construct the theoretical description of the boiling process and discuss the actualisation of the case we consider for real systems.

  14. 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.

  15. 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.

  16. Thermodynamic States and Phase Diagrams for Bulk-Incoherent, Bulk-Coherent, and Epitaxially-Coherent Semiconductor Alloys: Application to Cubic (Ga,In)N

    SciTech Connect (OSTI)

    Liu, J. Z.; Zunger, A.

    2008-01-01T23:59:59.000Z

    The morphology and microstructure of A{sub 1-x}B{sub x}C semiconductor alloys depend on the type of thermodynamic states established during growth. We distinguish three main cases: (i) bulk-incoherent structures occur when the alloy grows without being coherent with an underlying substrate and when each of the possible alloy species-phase separated AC and BC constituents, random A{sub 1-x}B{sub x}C alloy, or ordered (AC){sub n}/(BC){sub m} structures-maintain their own lattice structures and lattice constants, giving up mutual coherence. Bulk incoherence is common in thick films with sufficient dislocations. For cubic (Ga,In)N, bulk-incoherent structures are found to have a positive excess enthalpy {Delta}H{sub bulk}{sup incoh} > 0 and, thus, to phase separate. (ii) Bulk-coherent structures occur when the alloy grows without being coherent with a substrate, but each of the possible species internal to the alloy film is forced to be coherent with the film matrix. Thus, the constituents AC-rich and BC-rich solid solution phases share the same lattice structure at their interface, leading to internal strain that destabilizes the AC+BC separated constituents. This can expose the intermediate (AC){sub n}/(BC){sub m} ordered phases as stable structures with respect to the strained constituents, i.e., {Delta}H{sub bulk}{sup coh} < 0. Bulk coherence is applicable to growth when the development of dislocations is inhibited, e.g., small size precipitates in the alloy matrix. For cubic (Ga,In)N alloy, we find that the coherent ground state phases are three ordered superlattice structures: (InN){sub 2}/(GaN){sub 2} (=chacolpyrite), (InN){sub 3}/(GaN){sub 1}, and (InN){sub 4}/(GaN){sub 1}, along (201) [and its cubic symmetry equivalent, i.e., (102), (210), etc.] crystal direction. (iii) Epitaxially coherent structures occur when the alloy is made coherent with an underlying substrate, e.g., in thin film pseudomorphic growth. Depending on the substrate, the formation enthalpy {Delta}H{sup epi} < 0. For cubic (Ga,In)N grown on GaN (001) substrate, we find that the stablest epitaxial phases are chalcopyrite and the (InN){sub 4}/(GaN){sub 1} superlattice along the (210) crystal direction. Here, we calculate, from first principles, the formation enthalpies of cubic zinc blende (Ga,In)N alloy under the three forms of thermodynamic states indicated above to establish a cluster expansion, from which we calculate the finite-temperature phase diagrams. This illustrates how the thermodynamic constraints during growth can radically alter the alloy phase behavior and its microstructures.

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

    SciTech Connect (OSTI)

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

    2012-10-23T23:59:59.000Z

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

  18. 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.

  19. 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.

  20. 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.

  1. Bulk viscosity : a study from Polyakov-Nambu-Jona-Lasinio model

    E-Print Network [OSTI]

    Saha, Kinkar

    2015-01-01T23:59:59.000Z

    We present an extensive study of the bulk viscosity, $\\zeta$ using the framework of Kubo formalism within 2+1 flavored Polyakov-Nambu-Jona-Lasinio model. Alongwith, we have discussed the kinetic approaches in order to estimate the bulk viscous effects in the strongly interacting systems analogous to the situation in various high energy heavy-ion collisions. Our work strengthens the motivation for the proper incorporation of $\\zeta$ into the analysis of such systems. We also provide justification for such incorporation becoming more significant when density is substantially high.

  2. 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.

  3. Bulk viscosity : a study from Polyakov-Nambu-Jona-Lasinio model

    E-Print Network [OSTI]

    Kinkar Saha; Sudipa Upadhaya

    2015-05-01T23:59:59.000Z

    We present an extensive study of the bulk viscosity, $\\zeta$ using the framework of Kubo formalism within 2+1 flavored Polyakov-Nambu-Jona-Lasinio model. Alongwith, we have discussed the kinetic approaches in order to estimate the bulk viscous effects in the strongly interacting systems analogous to the situation in various high energy heavy-ion collisions. Our work strengthens the motivation for the proper incorporation of $\\zeta$ into the analysis of such systems. We also provide justification for such incorporation becoming more significant when density is substantially high.

  4. Method of aeration disinfecting and drying grain in bulk and pretreating seeds and a transverse blow silo grain dryer therefor

    DOE Patents [OSTI]

    Danchenko, Vitaliy G. (Dnipropetrovsk, UA); Noyes, Ronald T. (Stillwater, OK); Potapovych, Larysa P. (Dnipropetrovsk, UA)

    2012-02-28T23:59:59.000Z

    Aeration drying and disinfecting grain crops in bulk and pretreating seeds includes passing through a bulk of grain crops and seeds disinfecting and drying agents including an ozone and air mixture and surrounding air, subdividing the disinfecting and drying agents into a plurality of streams spaced from one another in a vertical direction, and passing the streams at different heights through levels located at corresponding heights of the bulk of grain crops and seeds transversely in a substantially horizontal direction.

  5. 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

  6. Oxide-Dependent Adsorption of a Model Membrane Phospholipid, Dipalmitoylphosphatidylcholine: Bulk Adsorption Isotherms

    E-Print Network [OSTI]

    Sahai, Nita

    Oxide-Dependent Adsorption of a Model Membrane Phospholipid, Dipalmitoylphosphatidylcholine: Bulk Adsorption Isotherms Timothy A. Oleson*, and Nita Sahai,,§ Department of Geology & Geophysics, 1215 West the substrate-dependence of phospholipid adsorption with an emphasis on oxide surface chemistry and to determine

  7. Cell multipole method for molecular simulations in bulk and confined systems

    E-Print Network [OSTI]

    Barr, Al

    Cell multipole method for molecular simulations in bulk and confined systems Jie Zheng Department. With the emergence of new simulations methodologies, such as the cell multipole method CMM , and massively parallel­particle and particle­mesh method PPPM 4,5 and the cell multipole method CMM .1­3 Both PPPM and CMM are more efficient

  8. Molecular dynamics simulations of gold-catalyzed growth of silicon bulk crystals and nanowires

    E-Print Network [OSTI]

    Cai, Wei

    ARTICLES Molecular dynamics simulations of gold-catalyzed growth of silicon bulk crystals of the orientation, yield, and quality of the NWs. Much of the studies on the VLS growth mechanism have been focused. In this article, we present the first set of MD simu- lations of NW growth using this Au­Si potential model

  9. 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

  10. Bulk and particle strain analysis in high-temperature deformation experiments

    E-Print Network [OSTI]

    Russell, Kelly

    and Russell [Quane, S.L., Russell, J.K., 2005a. Welding: insights from high-temperature analogue experimentsBulk and particle strain analysis in high-temperature deformation experiments Steven L. Quane a,, J. Keywords: image analysis; strain; welding; experimental; rheology 1. Introduction Rock deformation presses

  11. 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

  12. 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

  13. Modelling Bulk Density According to Structure Development: Toward an Indicator of Microstructure Development in Ferralsols.

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Modelling Bulk Density According to Structure Development: Toward an Indicator of Microstructure the microaggregates with a small contribution of large pores resulting from root development and macrofaunal activity.25 g cm-3 among the 108 samples studied. Visual assessment of BESI showed that soil material

  14. Bulk CMOS Device Optimization for High-Speed and Ultra-Low Power Operations

    E-Print Network [OSTI]

    Nyathi, Jabulani

    Bulk CMOS Device Optimization for High-Speed and Ultra-Low Power Operations Brent Bero and Jabulani- Interest in subthreshold design has increased due to the emergence of systems that require ultra-low power creating a clear divide between designing for high speed and ultra-low power. It might be beneficial

  15. 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.

  16. 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.

  17. FIELD MEASUREMENT OF HIGH TEMPERATURE BULK REACTION RATES I: THEORY AND TECHNIQUE

    E-Print Network [OSTI]

    Baxter, Ethan F.

    and mineral chemistry. The local equilibrium assumption, used in geochronology, geothermobarometry describe in detail the theory and methodology of a technique for extracting bulk reaction rates directly for the exchange process. Forward modeling of the reactive transport process using numerical methods

  18. 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...

  19. 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

  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 unclear. It is therefore important to carry out in situ observations of plastic deformation processes

  1. 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

  2. Measurement of Electron Beam Polarization from Unstrained Bulk GaAs via Two Photon Photoemission

    E-Print Network [OSTI]

    Gay, Timothy J.

    the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab, where the polarized electron beamMeasurement of Electron Beam Polarization from Unstrained Bulk GaAs via Two Photon Photoemission Collections Journals About Contact us My IOPscience #12;Measurement of Electron Beam Polarization from

  3. RF and Surface Properties of Bulk Niobium and Niobium Film Samples

    E-Print Network [OSTI]

    Junginger, Tobias; Weingarten, Wolfgang

    2012-01-01T23:59:59.000Z

    At CERN a compact Quadrupole Resonator has been developed for the RF characterization of superconducting samples at different frequencies. In this contribution measurements on bulk niobium and niobium ?lm on copper samples are presented. Surface resistance results are being correlated to surface analyses measurements carried out on the same samples.

  4. High sensitivity bulk electro-optic modulator field sensor for high voltage environments

    E-Print Network [OSTI]

    Shy,Jow-Tsong

    High sensitivity bulk electro-optic modulator field sensor for high voltage environments Mao December 2004) An optical electric field sensor is an effective instrument for surveying the electric attacked by unexpected electrical shocks through the metal cable of the sensor. Sensing by optical sensors

  5. Bulk viscosity and the phase transition of the linear sigma model

    E-Print Network [OSTI]

    Antonio Dobado; Juan M. Torres-Rincon

    2012-10-04T23:59:59.000Z

    In this work we deal with the critical behavior of the bulk viscosity in the linear sigma model (LSM) as an example of a system which can be treated by using different techniques. Starting from the Boltzmann-Uehling-Uhlenbeck equation we compute the bulk viscosity over entropy density of the LSM in the large-N limit. We search for a possible maximum of the bulk viscosity over entropy density at the critical temperature of the chiral phase transition. The information about this critical temperature, as well as the effective masses, is obtained from the effective potential. We find that the expected maximum (as a measure of the conformality loss) is absent in the large N in agreement with other models in the same limit. However, this maximum appears when, instead of the large-N limit, the Hartree approximation within the Cornwall-Jackiw-Tomboulis (CJT) formalism is used. Nevertheless, this last approach to the LSM does not give rise to the Goldstone theorem and also predicts a first order phase transition instead of the expected second order one. Therefore both, the large-N limit and the CJT-Hartree approximations, should be considered as complementary for the study of the critical behavior of the bulk viscosity in the LSM.

  6. Bulk viscosity, particle spectra and flow in heavy-ion collisions

    E-Print Network [OSTI]

    Kevin Dusling; Thomas Schaefer

    2012-01-11T23:59:59.000Z

    We study the effects of bulk viscosity on pT spectra and elliptic flow in heavy ion collisions. For this purpose we compute the dissipative correction df to the single particle distribution functions in leading-log QCD, and in several simplified models. We consider, in particular, the relaxation time approximation and a kinetic model for the hadron resonance gas. We implement these distribution functions in a hydrodynamic simulation of Au + Au collisions at RHIC. We find significant corrections due to bulk viscosity in hadron pT spectra and the differential elliptic flow parameter v2(pT). These corrections are dominated by viscous corrections to the distribution function. We find that the relation between df and the bulk viscosity is different in the quark gluon plasma and hadronic phases. Reliable bounds on the bulk viscosity require accurate calculations of df in a hadronic resonance gas. Based on v2 spectra at RHIC we conservatively estimate zeta/s viscosity on the pT integrated v2 are small.

  7. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 16, NO. 2, APRIL 2007 289 Bulk Micromachined Titanium Microneedles

    E-Print Network [OSTI]

    Titanium Microneedles E. R. Parker, M. P. Rao, K. L. Turner, C. D. Meinhart, and N. C. MacDonald Abstract used. In this paper, we demonstrate titanium-based microneedle devices developed to address-aspect-ratio titanium bulk microma- chining and multilayer lamination techniques. These devices include embedded

  8. BULK TITANIUM MICRONEEDLES WITH EMBEDDED MICROFLUIDIC NETWORKS FOR TRANSDERMAL DRUG DELIVERY

    E-Print Network [OSTI]

    MacDonald, Noel C.

    BULK TITANIUM MICRONEEDLES WITH EMBEDDED MICROFLUIDIC NETWORKS FOR TRANSDERMAL DRUG DELIVERY E. R micromachining of titanium for MEMS applications. Biomedical microsystems in particular can benefit from the high fracture toughness and biocompatibility associated with titanium. This paper reports on the design

  9. Bulk Stabilization, the Extra-Dimensional Higgs Portal and Missing Energy in Higgs Events

    E-Print Network [OSTI]

    Ross Diener; C. P. Burgess

    2013-02-26T23:59:59.000Z

    To solve the hierarchy problem, extra-dimensional models must explain why the new dimensions stabilize to the right size, and the known mechanisms for doing so require bulk scalars that couple to the branes. Because of these couplings the energetics of dimensional stabilization competes with the energetics of the Higgs vacuum, with potentially observable effects. These effects are particularly strong for one or two extra dimensions because the bulk-Higgs couplings can then be super-renormalizable or dimensionless. Experimental reach for such extra-dimensional Higgs `portals' are stronger than for gravitational couplings because they are less suppressed at low-energies. We compute how Higgs-bulk coupling through such a portal with two extra dimensions back-reacts onto properties of the Higgs boson. When the KK mass is smaller than the Higgs mass, mixing with KK modes results in an invisible Higgs decay width, missing-energy signals at high-energy colliders, and new mechanisms of energy loss in stars and supernovae. Astrophysical bounds turn out to be complementary to collider measurements, with observable LHC signals allowed by existing constraints. We comment on the changes to the Higgs mass-coupling relationship caused by Higgs-bulk mixing, and how the resulting modifications to the running of Higgs couplings alter vacuum-stability and triviality bounds.

  10. 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

  11. 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. Bareñoa , 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

  12. Elastic and Viscoelastic Properties of Non-bulk Polymer Interphases in Nanotube-reinforced Polymers

    E-Print Network [OSTI]

    Fisher, Frank

    Elastic and Viscoelastic Properties of Non-bulk Polymer Interphases in Nanotube-reinforced Polymers polymer composite materials with outstanding mechanical, electrical, and thermal properties. A hurdle to nanoscale interactions between the embedded NTs and adjacent polymer chains. This interphase region

  13. 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.

  14. Graphitic Phase of NaCl. Bulk Properties and Nanoscale Stability Alexander G. Kvashnin,,,

    E-Print Network [OSTI]

    Tománek, David

    Graphitic Phase of NaCl. Bulk Properties and Nanoscale Stability Alexander G. Kvashnin,,,§ Pavel B approach to evaluate the stability and physical properties of the nanometer-thickness NaCl layered films and found that the rock salt films with a (111) surface become unstable with thickness below 1 nm

  15. BulkSMT: Designing SMT Processors for Atomic-Block Execution

    E-Print Network [OSTI]

    Zaragoza, Universidad de

    BulkSMT: Designing SMT Processors for Atomic-Block Execution Xuehai Qian, Benjamin Sahelices single-context cores as building blocks -- rather than the widely-used Simultaneous Multithreading (SMT) cores. As a result, they are underutilizing hardware resources. This paper presents the first SMT design

  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. 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...

  18. GaN nanowires show more 3D piezoelectricity than bulk GaN

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Logo GaN nanowires show more 3D piezoelectricity than bulk GaN admin / January 11, 2012 individual gallium nitride (GaN) nanowires showing strong piezoelectric effect in 3D. This is in spite of the fact that each nanowire only measures 100nm in diameter. While GaN is ubiquitous in optoelectronic

  19. 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

  20. lehigh-logo Models and Simulation for Bulk Gas Production and

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    lehigh-logo Models and Simulation for Bulk Gas Production and Distribution Wasu Glankwamdee Jeff/Distribution ()Lehigh/Air Products Pittsburgh, PA 1 / 1 lehigh-logo In Our Last Episode(s)... Our project is studying;lehigh-logo Entities in the Production/Distribution Simulation Sites Location, Production Capacity

  1. 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.

  2. 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

  3. 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

  4. 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

    et al. (1996). The comparison shows that the shroud casing clearance flow and the fluid force moment can be simulated by the bulk flow model fairly well. An Iwatsubo-based labyrinth seal code developed by Childs and Scharrer (1986) is used...

  5. 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, ...

  6. 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 2011) Bulk SmCo5/a-Fe nanocomposite magnets have been prepared using a Joule-heating compaction of 2 GPa at temperatures above 400 C. Structural analysis shows that the grain size of both the SmCo5

  7. Evaluation of pneumatic nebulization and ns-laser ablation ICP-MS for bulk elemental analysis and 2-dimensional

    E-Print Network [OSTI]

    Claeys, Philippe

    Evaluation of pneumatic nebulization and ns-laser ablation ICP-MS for bulk elemental analysis and 2 nebulization and ns-laser ablation ICP-MS for bulk elemental analysis and 2-dimensional element mapping of iron 20XX DOI: 10.1039/b000000x The capabilities and limitations of nanosecond laser ablation ICP ­ mass

  8. Size-Induced Reduction of Transition Pressure and Enhancement of Bulk Modulus of AlN Nanocrystals

    E-Print Network [OSTI]

    Downs, Robert T.

    the bulk AlN by using the same technique. The nanosized wurtzite phase has a bulk modulus (B0) of 321 ( 19 decrease of 20.5% upon the wurtzite-to-rocksalt phase transformation. Combination of the size a significant reduction of transition pressure for the wurtzite-to-rocksalt phase transformation, and still

  9. 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

  10. 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

  11. 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

  12. The influence of crenulation cleavage development on the bulk elastic and seismic properties of phyllosilicate-rich rocks

    E-Print Network [OSTI]

    Vel, Senthil

    -rich, crustal rocks. We calculated the bulk elastic properties and resulting wave velocities for rock samplesThe influence of crenulation cleavage development on the bulk elastic and seismic properties of phyllosilicate-rich rocks Félice M.J. Naus-Thijssen a, , Andrew J. Goupee b , Scott E. Johnson a , Senthil S. Vel

  13. Intense femtosecond photoexcitation of bulk and monolayer MoS{sub 2}

    SciTech Connect (OSTI)

    Paradisanos, I.; Fotakis, C. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), Heraklion 71003 (Greece); Physics Department, University of Crete, Heraklion 71003 (Greece); Kymakis, E. [Center of Materials Technology and Photonics and Electrical Engineering Department, Technological Educational Institute (TEI) of Crete, Heraklion 71003 (Greece); Kioseoglou, G. [Materials Science and Technology Department, University of Crete, Heraklion 71003 (Greece); Stratakis, E., E-mail: stratak@iesl.forth.gr [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology-Hellas (FORTH), Heraklion 71003 (Greece); Materials Science and Technology Department, University of Crete, Heraklion 71003 (Greece)

    2014-07-28T23:59:59.000Z

    The effect of femtosecond laser irradiation on bulk and single-layer MoS{sub 2} on silicon oxide is studied. Optical, field emission scanning electron microscopy and Raman microscopy were used to quantify the damage. The intensity of A{sub 1g} and E{sub 2g}{sup 1} 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 800?nm and 1030?nm pulsed laser irradiation, and the role of two-photon versus one photon absorption effects is discussed.

  14. 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).

  15. Noncentrosymmetric salt inclusion oxides: Role of salt lattices and counter ions in bulk polarity

    SciTech Connect (OSTI)

    West, J. Palmer [Department of Chemistry, Clemson University, Clemson, SC 29634-0973 (United States)] [Department of Chemistry, Clemson University, Clemson, SC 29634-0973 (United States); Hwu, Shiou-Jyh, E-mail: shwu@clemson.edu [Department of Chemistry, Clemson University, Clemson, SC 29634-0973 (United States)] [Department of Chemistry, Clemson University, Clemson, SC 29634-0973 (United States)

    2012-11-15T23:59:59.000Z

    The synthesis and structural features of a newly emerged class of salt-inclusion solids (SISs) are reviewed. The descriptive chemistry with respect to the role of ionic salt and its correlation with bulk noncentrosymmetricity and polarity of the covalent oxide lattice in question is discussed by means of structure analysis. These unprecedented discoveries have opened doors to novel materials synthesis via the utilities of salt-inclusion chemistry (SIC) that are otherwise known as the molten-salt approach. The result of these investigations prove that the bulk acentricity, or cancellation of which, can be accounted for from the perspective of ionic and/or salt lattices. Highlights: Black-Right-Pointing-Pointer Synthesis and structure of newly emerged salt-inclusion solids are reviewed. Black-Right-Pointing-Pointer Salt lattice and its symmetry correlation with polar framework are discussed. Black-Right-Pointing-Pointer Preservation of acentricity is accounted for from the perspective of ionic and salt lattices.

  16. 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.

  17. Systematic optimization of quantum junction colloidal quantum dot solar Huan Liu, David Zhitomirsky, Sjoerd Hoogland, Jiang Tang, Illan J. Kramer et al.

    E-Print Network [OSTI]

    centers and photovoltaic degradation in polythiophene-fullerene bulk heterojunction solar cells APL: Org. Electron. Photonics 5, 204 (2012) Correlation between density of paramagnetic centers and photovoltaic degradation in polythiophene-fullerene bulk heterojunction solar cells Appl. Phys. Lett. 101, 103306 (2012

  18. 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...

  19. 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.

  20. A calcium oxide sorbent process for bulk separation of carbon dioxide

    SciTech Connect (OSTI)

    Harrison, D.P.

    1992-10-01T23:59:59.000Z

    Objective is to investigate the feasibility of a high-temperature, high-pressure process for bulk separation of CO[sub 2] from coal- derived gas. An electrobalance reactor was used in Phase I; in Phase II, the switch was made to a fixed-bed reactor with capability for feed and product gas analysis. A gas chromatograph was delivered, installed, and operator training carried out. The sampling valve sequence is discussed.

  1. Comparing ultrafast surface and bulk heating using time-resolved electron diffraction

    SciTech Connect (OSTI)

    Streubühr, C.; Kalus, A.; Zhou, P., E-mail: ping.zhou@uni-due.de; Kammler, M.; Linde, D. von der [Faculty of Physics, University of Duisburg-Essen, Duisburg 47057 (Germany); Ligges, M.; Hanisch-Blicharski, A.; Bovensiepen, U.; Horn-von Hoegen, M. [Faculty of Physics, University of Duisburg-Essen, Duisburg 47057 (Germany); CENIDE, Centre for Nano Integration Duisburg Essen, Duisburg 47057 (Germany)

    2014-04-21T23:59:59.000Z

    From measurements of the transient Debye-Waller effect in Bismuth, we determine the buildup time of the random atomic motion resulting from the electronic relaxation after short pulse laser excitation. The surface sensitive reflection high energy electron diffraction and transmission electron diffraction yield a time constant of about 12 ps and 3 ps, respectively. The different energy transfer rates indicate relatively weak coupling between bulk and surface vibrational modes.

  2. 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

  3. A calcium oxide sorbent process for bulk separation of carbon dioxide

    SciTech Connect (OSTI)

    Harrison, D.P.

    1992-04-01T23:59:59.000Z

    This research project is investigating the technical feasibility of a high-temperature, high-pressure process for the bulk separation of CO[sub 2] from coal-derived gas. Phase I consisted of 6 tasks. Phase II added a seventh task to the project. This report is limited to a description of the final experimental results obtained in Phase I, Task 5 (multicycle tests), and a brief overview of justification and plans for Phase II, Task 7.

  4. 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}.

  5. 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.

  6. 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.

  7. 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 75ìm) 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.

  8. 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.

  9. Microstructure and Magnetic Properties of PrMnO{sub 3} Bulk and Thin Film

    SciTech Connect (OSTI)

    Lim, K. P.; Halim, S. A.; Chen, S. K.; Ng, S. W.; Wong, J. K.; Gan, H. M. Albert [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor (Malaysia); Woon, H. S. [College of Engineering, Universiti Tenaga Nasional, Jalan IKRAM-UNITEN, 43000 Kajang, Selangor (Malaysia)

    2011-03-30T23:59:59.000Z

    Perovskite PrMnO{sub 3}(PMO) had been prepared in bulk by solid state reaction and thin films on corning glass, fused silica and MgO (100) glass substrate by pulsed laser deposition technique. SEM micrographs show that grains with size 2{approx}3 {mu}m is observed in bulk PMO while thin films PMO show strongly connected grain structure with particle size that not larger than 100 nm. X-ray diffraction analysis shows that all samples are in single phase with orthorhombic crystal structure. Bulk PMO sample had lattice strain of 0.134% which is the lowest value among others. However, larger lattice strain was observed in thin film samples due to lattice mismatch between film-substrate and caused the MnO{sub 6} to deform. All samples shown paramagnetic or antiferromagnetic behavior, enhancement in magnetization value occurred for all PMO grew as film. We believe that larger lattice strain favor the grain growth of PMO towards more order phase. In summary, formation of structure and microstructure of thin film PMO depends on type of substrate used and it affect the magnetic property.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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...

  16. 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

  17. 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

  18. 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 ...

  19. A mechanistic model for understanding pH effect on phosphorus availability in rhizosphere and bulk soil

    E-Print Network [OSTI]

    DEVAU, Nicolas; Le Cadre, Edith; Hinsinger, Philippe; Gérard, Frédéric

    2009-01-01T23:59:59.000Z

    soil with low P availability. Biol. Fertil. Soils. , 44:143-to the use of the P availability obtained for bulk soilcan indeed alter P availability in the rhizosphere (e.g.

  20. 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...

  1. 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...

  2. 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

    physical properties. Because the soil compaction depends on its water content, bulk density and texture was obtained between soil precompression stress, compression index, initial water content, initial bulk density, 1994). Thus, knowing the changes in soil compaction with changes in water content and bulk density

  3. Low-energy effective theory in the bulk for transport in a topological phase

    E-Print Network [OSTI]

    Barry Bradlyn; N. Read

    2015-02-15T23:59:59.000Z

    We construct a low-energy effective action for a two-dimensional non-relativistic topological (i.e.\\ gapped) phase of matter in a continuum, which completely describes all of its bulk electrical, thermal, and stress-related properties in the limit of low frequencies, long distances, and zero temperature, without assuming either Lorentz or Galilean invariance. This is done by generalizing Luttinger's approach to thermoelectric phenomena, via the introduction of a background vielbein (i.e.\\ gravitational) field and spin connection a la Cartan, in addition to the electromagnetic vector potential, in the action for the microscopic degrees of freedom (the matter fields). Crucially, the geometry of spacetime is allowed to have timelike and spacelike torsion. These background fields make all natural invariances--- under U(1) gauge transformations, translations in both space and time, and spatial rotations---appear locally, and corresponding conserved currents and the stress tensor can be obtained, which obey natural continuity equations. On integrating out the matter fields, we derive the most general form of a local bulk induced action to first order in derivatives of the background fields, from which thermodynamic and transport properties can be obtained. We show that the gapped bulk cannot contribute to low-temperature thermoelectric transport other than the ordinary Hall conductivity; the other thermoelectric effects (if they occur) are thus purely edge effects. The coupling to "reduced" spacelike torsion is found to be absent in minimally-coupled models, and using a generalized Belinfante stress tensor, the stress response to time-dependent vielbeins (i.e.\\ strains) is the Hall viscosity, which is robust against perturbations and related to the spin current as in earlier work.

  4. 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).

  5. Emission mechanisms of bulk GaN and InGaN quantum wells prepared by lateral epitaxial overgrowth

    E-Print Network [OSTI]

    Bowers, John

    Emission mechanisms of bulk GaN and InGaN quantum wells prepared by lateral epitaxial overgrowth S for publication 5 January 1999 The emission mechanisms of bulk GaN and InGaN quantum wells QWs were studied suggest that TDs simply reduce the net volume of light-emitting area. This effect is less pronounced in InGaN

  6. Comparison of strong coupling regimes in bulk GaAs, GaN and ZnO semiconductor microcavities

    E-Print Network [OSTI]

    Boyer, Edmond

    , transmission and absorption spectra of bulk GaAs, GaN and ZnO microcavities, in order to compareComparison of strong coupling regimes in bulk GaAs, GaN and ZnO semiconductor microcavities SAs and GaN microcavities. PACS numbers: 78.67.-n, 71.36.+c, 78.20.Ci, 78.55.Cr, 78.55.Et Keywords: polariton

  7. 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.

  8. Identification of Bulk coupling constant in Higher Spin/ABJ correspondence

    E-Print Network [OSTI]

    Honda, Masazumi

    2015-01-01T23:59:59.000Z

    We study the conjectured duality between the $\\mathcal{N}=6$ Vasiliev higher spin theory on $AdS_4$ and 3d $\\mathcal{N}=6$ superconformal Chern-Simons matter theory known as the ABJ theory. We discuss how the parameters in the ABJ theory should be related to the bulk coupling constant in the Vasiliev theory. For this purpose, we compute two-point function of stress tensor in the ABJ theory by using supersymmmetry localization. Our result justifies the proposal by arXiv:1504.00365 and determine the unknown coefficient in the previous work.

  9. Identification of Bulk coupling constant in Higher Spin/ABJ correspondence

    E-Print Network [OSTI]

    Masazumi Honda

    2015-06-16T23:59:59.000Z

    We study the conjectured duality between the $\\mathcal{N}=6$ Vasiliev higher spin theory on $AdS_4$ and 3d $\\mathcal{N}=6$ superconformal Chern-Simons matter theory known as the ABJ theory. We discuss how the parameters in the ABJ theory should be related to the bulk coupling constant in the Vasiliev theory. For this purpose, we compute two-point function of stress tensor in the ABJ theory by using supersymmmetry localization. Our result justifies the proposal by arXiv:1504.00365 and determine the unknown coefficient in the previous work.

  10. 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.

  11. Jump Chaotic Behaviour of Ultra Low Loss Bulk Acoustic Wave Cavities

    E-Print Network [OSTI]

    Maxim Goryachev; Warrick G. Farr; Serge Galliou; Michael E. Tobar

    2014-06-16T23:59:59.000Z

    We demonstrate a previously unobserved nonlinear phenomenon in an ultra-low loss quartz Bulk Acoustic Wave cavity ($Q>3\\times10^9$), which only occurs below 20 milli-Kelvin 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 lays beyond the standard Duffing model.

  12. 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.

  13. Nonlinear bulk viscosity and the stability of accelerated expansion in FRW spacetime

    E-Print Network [OSTI]

    G. Acquaviva; A. Beesham

    2014-05-14T23:59:59.000Z

    In the context of dark energy solutions, we consider a Friedmann-Robertson-Walker spacetime filled with a non-interacting mixture of dust and a viscous fluid, whose bulk viscosity is governed by the nonlinear model proposed in [15]. Through a phase space analysis of the equivalent dynamical system, existence and stability of critical solutions are established and the respective scale factors are computed. The results point towards the possibility of describing the current accelerated expansion of the Universe by means of the abovementioned nonlinear model for viscosity.

  14. Bulk viscosity-driven freeze-out in heavy ion collisions

    E-Print Network [OSTI]

    Giorgio Torrieri; Igor Mishustin; Boris Tomášik

    2009-01-02T23:59:59.000Z

    We give an review the HBT puzzle, and argue that its resolution requires the introduction of new physics close to the phase transition scale. We argue that a candidate for this new physics is bulk viscosity, recently postulated to peak, and even diverge, close to the phase transition temperature. We show that such a viscosity peak can force the system created in heavy ion collisions to become unstable, and filament into fragments whose size is weakly dependent on the global size of the system, thereby triggering freeze-out.

  15. 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.

  16. On the origin of elastic strain limit of bulk metallic glasses

    SciTech Connect (OSTI)

    Ding, J., E-mail: ding@jhu.edu; Ma, E., E-mail: ema@jhu.edu [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Cheng, Y. Q. [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Chemical and Engineering Materials Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

    2014-01-06T23:59:59.000Z

    All bulk metallic glasses exhibit a large and almost universal elastic strain limit. Here, we show that the magnitude of the yield strain of the glass state can be quantitatively derived from a characteristic property of the flow state typical in running shear bands (the root cause of yielding). The strain in the shear flow is mostly plastic, but associated with it there is an effective elastic atomic strain. The latter is almost identical for very different model systems in our molecular dynamics simulations, such that the corresponding yield strain is universal at any given homologous temperature.

  17. 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.

  18. File:08COaBulkTransmissionSitingProcess.pdf | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are8COaBulkTransmissionSitingProcess.pdf Jump to: navigation, search File File history File usage Metadata

  19. 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.

  20. 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.

  1. 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.

  2. THE IMPACT OF PARTIAL CRYSTALLIZATION ON THE PERMEATION PROPERTIES BULK AMORPHOUS GLASS HYDROGEN SEPARATION MEMBRANES

    SciTech Connect (OSTI)

    Brinkman, K; Paul Korinko, P; Thad Adams, T; Elise Fox, E; Arthur Jurgensen, A

    2008-11-25T23:59:59.000Z

    It is recognized that hydrogen separation membranes are a key component of the emerging hydrogen economy. A potentially exciting material for membrane separations are bulk metallic glass materials due to their low cost, high elastic toughness and resistance to hydrogen 'embrittlement' as compared to crystalline Pd-based membrane systems. However, at elevated temperatures and extended operation times structural changes including partial crystallinity may appear in these amorphous metallic systems. A systematic evaluation of the impact of partial crystallinity/devitrification on the diffusion and solubility behavior in multi-component Metallic Glass materials would provide great insight into the potential of these materials for hydrogen applications. This study will report on the development of time and temperature crystallization mapping and their use for interpretation of 'in-situ' hydrogen permeation at elevated temperatures.

  3. 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.

  4. Superconductivity in bulk A15 Nb/sub 3/Si under pressure

    SciTech Connect (OSTI)

    Lim, K.C.; Thompson, J.D.; Olinger, B.; Newkirk, L.R.

    1981-12-01T23:59:59.000Z

    We have determined the effect of hydrostatic pressure P on the superconducting transition temperature T/sub c/ of bulk, A15 Nb/sub 3/Si. For 0< or =P< or =20 kbar (2 GPa), T/sub c/ decrease linearly with increasing pressure at the rate partialP/sub c//partialP = -2.67 x 10/sup -5/ K/bar. From an estimate of partialT/sub c//partialP obtained using recent band structure calculations for the density-of-electronic-states change as a function of lattice parameter in Nb/sub 3/Si, we conclude that the pressure dependence of the electron-phonon interaction primarily determines partialT/sub c//partialP.

  5. Short time proton dynamics in bulk ice and in porous anode solid oxide fuel cell materials

    SciTech Connect (OSTI)

    Basoli, Francesco [Università degli Studi di Roma Tor Vergata, Italy] [Università degli Studi di Roma Tor Vergata, Italy; Senesi, Roberto [ORNL] [ORNL; Kolesnikov, Alexander I [ORNL] [ORNL; Licoccia, Silvia [NAST Center, University of Roma "Tor Vergata"] [NAST Center, University of Roma "Tor Vergata"

    2014-01-01T23:59:59.000Z

    Oxygen reduction and incorporation into solid electrolytes and the reverse reaction of oxygen evolution play a cru-cial role in Solid Oxide Fuel Cell (SOFC) applications. However a detailed un derstanding of the kinetics of the cor-responding reactions, i.e. on reaction mechanisms, rate limiting steps, reaction paths, electrocatalytic role of materials, is still missing. These include a thorough characterization of the binding potentials experienced by protons in the lattice. We report results of Inelastic Neutron Scattering (INS) measurements of the vibrational state of the protons in Ni- YSZ highly porous composites (75% to 90% ), a ceramic-metal material showing a high electrical conductivity and ther mal stability, which is known to be most effectively used as anodes for solid ox ide fuel cells. The results are compared with INS and Deep Inelastic Neutron Scattering (DINS) experiments on the proton binding states in bulk ice.

  6. A semiflexible polymer chain under geometrical restrictions: Only bulk behaviour and no surface adsorption

    E-Print Network [OSTI]

    Pramod Kumar Mishra

    2014-07-11T23:59:59.000Z

    We analyse the conformational behaviour of a linear semiflexible homo-polymer chain confined by two geometrical constraints under a good solvent condition in two dimensions. The constraints are stair shaped impenetrable surfaces. The impenetrable surfaces are lines in a two dimensional space. The infinitely long polymer chain is confined in between such two (A and B) surfaces. A lattice model of a fully directed self-avoiding walk is used to calculate the exact expression of the partition function, when the chain has attractive interaction with one or both the constraints. It has been found that under the proposed model, the chain shows only a bulk behaviour. In other words, there is no possibility of adsorption of the chain due to restrictions imposed on the walks of the chain.

  7. Low beryllium content Zr-based bulk metallic glass composite with plasticity and work hardenability

    SciTech Connect (OSTI)

    Zheng, Q., E-mail: qiangzheng616@hotmail.com, E-mail: dujuan@nimte.ac.cn [School of Materials Science and Engineering, Ningbo University of Technology, Ningbo, 315016, China and Ningbo Branch of China Academy of Ordnance Science, Ningbo, 315103 (China); Du, J., E-mail: qiangzheng616@hotmail.com, E-mail: dujuan@nimte.ac.cn [Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering (NIMTE), Chinese Academy of Sciences (CAS), Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, NIMTE, CAS, Ningbo 315201 (China)

    2014-01-28T23:59:59.000Z

    A modified Zr-based bulk metallic glass matrix composite Zr{sub 47.67}Cu{sub 40}Ti{sub 3.66}Ni{sub 2.66}Be{sub 6} has been produced by increasing the contents of elements of Zr and Cu with higher Poisson ratio and reducing the contents of Ti, Ni, and Be elements with lower Poisson ratio based on famous metallic glass former Vitreloy 1. A compressive yielding strength of 1804?MPa, fracture strength of 1938?MPa and 3.5% plastic strain was obtained for obtained metallic glass composite. Also, work-hardening behavior was observed during compressive experiment which was ascribed to the interaction of the in situ precipitated CuZr phase and shear bands.

  8. Numerical design of SiC bulk crystal growth for electronic applications

    SciTech Connect (OSTI)

    Wejrzanowski, T.; Grybczuk, M.; Kurzydlowski, K. J. [Warsaw University of Technology, Faculty of Materials Science and Engineering, Woloska 141, 02507 Warsaw (Poland); Tymicki, E. [Institute of Electronic Materials Technology, Wolczynska 133, 01919 Warsaw (Poland)

    2014-10-06T23:59:59.000Z

    Presented study concerns numerical simulation of Physical Vapor Transport (PVT) growth of bulk Silicon Carbide (SiC) crystals. Silicon Carbide is a wide band gap semiconductor, with numerous applications due to its unique properties. Wider application of SiC is limited by high price and insufficient quality of the product. Those problems can be overcame by optimizing SiC production methods. Experimental optimization of SiC production is expensive because it is time consuming and requires large amounts of energy. Numerical modeling allows to learn more about conditions inside the reactor and helps to optimize the process at much lower cost. In this study several simulations of processes with different reactor geometries were presented along with discussion of reactor geometry influence on obtained monocrystal shape and size.

  9. 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.

  10. 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.

  11. Local and bulk 13C hyperpolarization in NV-centered diamonds at variable fields and orientations

    E-Print Network [OSTI]

    Alvarez, Gonzalo A; Fischer, Ran; London, Paz; Kanda, Hisao; Onoda, Shinobu; Isoya, Junichi; Gershoni, David; Frydman, Lucio

    2014-01-01T23:59:59.000Z

    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 ...

  12. Serrated flow behaviors of a Zr-based bulk metallic glass by nanoindentation

    SciTech Connect (OSTI)

    Cheng, L.; Jiao, Z. M.; Ma, S. G.; Wang, Z. H., E-mail: qiaojunwei@gmail.com, E-mail: wangzhihua@tyut.edu.cn [Institute of Applied Mechanics and Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Qiao, J. W., E-mail: qiaojunwei@gmail.com, E-mail: wangzhihua@tyut.edu.cn [Institute of Applied Mechanics and Biomedical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Laboratory of Applied Physics and Mechanics of Advanced Materials, College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan 030024 (China)

    2014-02-28T23:59:59.000Z

    Instrumented nanoindentation tests were used to investigate the mechanical properties of Zr{sub 52.5}Cu{sub 17.9}Ni{sub 14.6}Al{sub 10}Ti{sub 5} bulk metallic glass. The corresponding loading strain rates were ranged from 0.002?s{sup ?1}, 0.02?s{sup ?1} to 0.2?s{sup ?1}. Plastic flow of this material exhibited remarkable serrations at low strain rates and increasingly became weakening until disappearance with increasing indentation strain rate, implying strong rate sensitivity. A significant pile-up around the indents was observed through atomic force microscopy, which suggested a highly localized plastic deformation. Mechanism governing the deformation was tentatively discussed in terms of the increasing process of free volume with a negligible temperature rise under low strain rate, which well explained the declining trend of elastic modulus and hardness with an increase of indentation depth.

  13. 9 T high magnetic field annealing effects on FeN bulk sample

    SciTech Connect (OSTI)

    Jiang, Yanfeng; Wang, Jian-Ping, E-mail: jpwang@umn.edu [Department of Electrical and Computer Engineering, University of Minnesota, Minneapolis, Minneota 55455 (United States); Dabade, Vivekanand; James, Richard D. [Department of Aerospace Engineering and Mechanics, University of Minnesota, Minneapolis, Minnesota 55455 (United States); Brady, Michael P.; Rios, Orlando [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831–6115 (United States)

    2014-05-07T23:59:59.000Z

    ??-Fe{sub 16}N{sub 2} has been suggested as a promising candidate for future rare-earth-free magnets. In this paper, we report to use high magnetic field (9?T) assisted post-annealing process to enhance the Fe{sub 16}N{sub 2} phase formation in FeN bulk rod samples during the ?? ? ?? phase transformation and thus improve its magnetic properties. It was found by X-ray Diffraction measurement that the volume ratio of Fe{sub 16}N{sub 2} phase was increased up to 22%, which corresponds to an increase in the amount of transformation from ?? ? ?? up to 78%. Also, the saturation magnetization (M{sub s}) of the prepared FeN rod sample was increased to 227?emu/g with its coercivity up to 376?Oe at room temperature. A working mechanism for the high field assisted post-annealing process was presented.

  14. Picosecond Z-scan measurements on bulk GaN crystals

    SciTech Connect (OSTI)

    Pacebutas, V.; Stalnionis, A.; Krotkus, A.; Suski, T.; Perlin, P.; Leszczynski, M.

    2001-06-25T23:59:59.000Z

    Bulk GaN crystals were characterized by using picosecond laser pulses at {lambda}=0.527{mu}m and Z-scan techniques. The role of the free-carrier absorption was evaluated by a dynamical, pump-and-probe-type transmitivity measurement. The values of two-photon absorption coefficient (17{endash}20 cm/GW) and refractive index changes at high optical irradiances due to bound (n{sub 2}={minus}4{times}10{sup {minus}12}esu) and free ({sigma}{sub r}={minus}1.0{times}10{sup {minus}20}cm{sup 3}) electrons in that material were determined. {copyright} 2001 American Institute of Physics.

  15. Radiation detector using a bulk high T.sub.c superconductor

    DOE Patents [OSTI]

    Artuso, Joseph F. (Santa Barbara, CA); Franks, Larry A. (Santa Barbara, CA); Hull, Kenneth L. (Ventura, CA); Symko, Orest G. (Salt Lake City, UT)

    1993-01-01T23:59:59.000Z

    A radiation detector (10) is provided, wherein a bulk high T.sub.c superconducting sample (11) 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 (12) which is coupled by an input coil (15) to an rf SQUID (16).

  16. 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.

  17. 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.

  18. 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 $\\bar{n}$.

  19. A new measurement of the bulk flow of X-ray luminous clusters of galaxies

    E-Print Network [OSTI]

    A. Kashlinsky; F. Atrio-Barandela; H. Ebeling; A. Edge; D. Kocevski

    2010-03-11T23:59:59.000Z

    We present new measurements of the large-scale bulk flows of galaxy clusters based on 5-year WMAP data and a significantly expanded X-ray cluster catalogue. Our method probes the flow via measurements of the kinematic Sunyaev-Zeldovich (SZ) effect produced by the hot gas in moving clusters. It computes the dipole in the cosmic microwave background (CMB) data at cluster pixels, which preserves the SZ component while integrating down other contributions. Our improved catalog of over 1,000 clusters enables us to further investigate possible systematic effects and, thanks to a higher median cluster redshift, allows us to measure the bulk flow to larger scales. We present a corrected error treatment and demonstrate that the more X-ray luminous clusters, while fewer in number, have much larger optical depth, resulting in a higher dipole and thus a more accurate flow measurement. This results in the observed correlation of the dipole derived at the aperture of zero monopole with the monopole measured over the cluster central regions. This correlation is expected if the dipole is produced by the SZ effect and cannot be caused by unidentified systematics (or primary cosmic microwave background anisotropies). We measure that the flow is consistent with approximately constant velocity out to at least 800 Mpc. The significance of the measured signal peaks around 500 Mpc, most likely because the contribution from more distant clusters becomes progressively more diluted by the WMAP beam. We can, however, at present not rule out that these more distant clusters simply contribute less to the overall motion.

  20. Proton irradiation effects on critical current of bulk single-crystal superconducting YBCO wire

    SciTech Connect (OSTI)

    Khanna, S.M. [Defence Research Establishment Ottawa, Ontario (Canada)] [Defence Research Establishment Ottawa, Ontario (Canada); Figueredo, A.M. [National Research Council, Boucherville, Quebec (Canada). Industrial Materials Inst.] [National Research Council, Boucherville, Quebec (Canada). Industrial Materials Inst.

    1997-12-01T23:59:59.000Z

    The authors have investigated the effects of 10 MeV proton irradiation on the magnetization M and critical current density J{sub c} of bulk single-crystal YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} (YBCO) superconducting thick wire filaments produced through laser-heated floating zone (LHFZ) technique. M and J{sub c} were determined both along the length and perpendicular to the length of the wire. Radiation-induced enhancement of J{sub c} along the length of the wire was observed while there was a small decrease in J{sub c} {perpendicular} to its length. J{sub c} values along the length of the wire up to {approximately}1.4 {times} 10{sup 5} A/cm{sup 2} at 77K and {approximately}1.3 {times} 10{sup 6} A/cm{sup 2} at 30K and in applied magnetic field H = 1 T were observed in the irradiated samples. In the unirradiated sample, the difference in magnetization {Delta}M at a given field in the magnetic hysteresis loop for increasing and decreasing field applied {perpendicular} to the sample length was observed to depend on the orientation of the sample about its axis. This indicates anisotropy in J{sub c} along the sample length. This anisotropy increased on irradiation relative to the direction of irradiation. They believe that these J{sub c} values along the length are amongst the highest published J{sub c} values for bulk high temperature superconductor (HTS) thick wire filament.