Sample records for frv si transport

  1. FRV SI Transport Solar LP | Open Energy Information

    Open Energy Info (EERE)

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  2. ccsd-00097094,version1-21Sep2006 Electron transport through antidot superlattices in Si/SiGe heterostructures: new

    E-Print Network [OSTI]

    Boyer, Edmond

    ccsd-00097094,version1-21Sep2006 Electron transport through antidot superlattices in Si/SiGe investigated the transport properties in a number of Si/SiGe sam- ples with square antidot latticesAs/AlGaAs and Si/SiGe samples with antidot lattices. In samples with a 600 nm lattice period a new series of well

  3. Single charge sensing and transport in double quantum dots fabricated from commercially grown Si/SiGe heterostructures

    E-Print Network [OSTI]

    Payette, C; Koppinen, P J; Dovzhenko, Y; Sturm, J C; Petta, J R

    2011-01-01T23:59:59.000Z

    We perform quantum Hall measurements on three types of commercially available modulation doped Si/SiGe heterostructures to determine their suitability for depletion gate defined quantum dot devices. By adjusting the growth parameters, we are able to achieve electron gases with charge densities 1-3 X 10^{11}/cm^2 and mobilities in excess of 100,000 cm^2/Vs. Double quantum dot devices fabricated on these heterostructures show clear evidence of single charge transitions as measured in dc transport and charge sensing and exhibit electron temperatures of 100 mK in the single quantum dot regime.

  4. Single charge sensing and transport in double quantum dots fabricated from commercially grown Si/SiGe heterostructures

    E-Print Network [OSTI]

    C. Payette; K. Wang; P. J. Koppinen; Y. Dovzhenko; J. C. Sturm; J. R. Petta

    2012-03-21T23:59:59.000Z

    We perform quantum Hall measurements on three types of commercially available modulation doped Si/SiGe heterostructures to determine their suitability for depletion gate defined quantum dot devices. By adjusting the growth parameters, we are able to achieve electron gases with charge densities 1-3 X 10^{11}/cm^2 and mobilities in excess of 100,000 cm^2/Vs. Double quantum dot devices fabricated on these heterostructures show clear evidence of single charge transitions as measured in dc transport and charge sensing and exhibit electron temperatures of 100 mK in the single quantum dot regime.

  5. Ferromagnetism and Nonmetallic Transport of Thin-Film ? - FeSi 2 : A Stabilized Metastable Material

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

    Cao, Guixin; Singh, D.?J.; Zhang, X.-G.; Samolyuk, German; Qiao, Liang; Parish, Chad; Jin, Ke; Zhang, Yanwen; Guo, Hangwen; Tang, Siwei; Wang, Wenbin; Yi, Jieyu; Cantoni, Claudia; Siemons, Wolter; Payzant, E. Andrew; Biegalski, Michael; Ward, T.?Z.; Mandrus, David; Stocks, G.?M.; Gai, Zheng

    2015-04-01T23:59:59.000Z

    A metastable phase ?-FeSi? was epitaxially stabilized on a silicon substrate using pulsed laser deposition. Nonmetallic and ferromagnetic behaviors are tailored on ?-FeSi? (111) thin films, while the bulk material of ?-FeSi? is metallic and nonmagnetic. The transport property of the films renders two different conducting states with a strong crossover at 50 K, which is accompanied by the onset of a ferromagnetic transition as well as a substantial magnetoresistance. These experimental results are discussed in terms of the unusual electronic structure of ?-FeSi? obtained within density functional calculations and Boltzmann transport calculations with and without strain. Our finding sheds light on achieving ferromagnetic semiconductors through both their structure and doping tailoring, and provides an example of a tailored material with rich functionalities for both basic research and practical applications.

  6. Si Nanopores Development for External Control of Transport of Biomolecules

    SciTech Connect (OSTI)

    Ileri, N; Tringe, J; Letant, S; Palozoglu, A; Stroeve, P; Faller, R

    2008-06-13T23:59:59.000Z

    Nazar Ileri has been involved in an independent, multidisciplinary effort to create a new class of molecular sieves for proteins and viruses. Her experimental work has been performed concurrently at two campuses, LLNL and UC Davis, while theoretical components have been largely accomplished at UC Davis. As will be described, the devices she is creating have great potential to improve very significantly the efficiency and selectivity of molecular transport over what is presently available from state-of-the-art membranes. Our biotechnology training program is based on an integrated study of the transport of biomolecules through conically-shaped, nanoporous silicon membranes. The overall objective of this effort is to demonstrate an efficient, highly selective membrane technology that is manufacturable for macroscopic areas and can be employed in sensing, diagnostic and biomedical applications. Our specific aims are to (1) fabricate and characterize the physical characteristics of the membranes, (2) to demonstrate their utility for molecular transport and separation, and (3) to develop models that will facilitate understanding of these devices as well as improved performance of the next generation of devices. We have proposed that the conical pores have superior performance characteristics compared to other porous filters. To study this hypothesis, complementary approaches from different disciplines, such as membrane synthesis, experiment, and molecular simulation need to be combined. This provides an ideal training environment for a future leader in biotechnology. Hence, for this study, Nazar Ileri has started to carry out a full range of experimental and theoretical investigations under our guidance. First, she has begun fabrication of filters with conical/pyramidal pores. She characterized the pores by AFM and SEM, and analyzed the images using wavelets and other mathematical tools. She has also started to conduct biomolecule transport experiments to compare the efficiency of fabricated filters vs. state-of-the-art commercial polycarbonate track-etched (PCTE) membranes. Finally, she has performed preliminary molecular calculations to investigate the operating principles of such systems and she has obtained results which she will present at the international 'Nanostructured materials, membrane modeling and simulation' workshop in Greece.

  7. Anomalous diameter dependence of thermal transport in ultra-narrow Si nanowires

    SciTech Connect (OSTI)

    Karamitaheri, Hossein, E-mail: karami@iue.tuwien.ac.at [Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, A-1040 Wien (Austria); Department of Electrical Engineering, University of Kashan, Kashan, 87317-51167 (Iran, Islamic Republic of); Neophytou, Neophytos, E-mail: neophytou@iue.tuwien.ac.at [Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, A-1040 Wien (Austria); School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom); Kosina, Hans, E-mail: kosina@iue.tuwien.ac.at [Institute for Microelectronics, TU Wien, Gußhausstraße 27-29/E360, A-1040 Wien (Austria)

    2014-01-14T23:59:59.000Z

    We present atomistic valence force field calculations of thermal transport in Si nanowires of diameters from 12?nm down to 1?nm. We show that as the diameter is reduced, the phonon density-of-states and transmission function acquire a finite value at low frequency, in contrast to approaching zero as in the bulk material. It turns out that this effect results in what Ziman described as the “problem of long longitudinal waves” [J. M. Ziman, Electrons and Phonons: The Theory of Transport Phenomena in Solids (Clarendon, Oxford, 1962)], which states that the thermal conductivity of a material increases as its length is increased due to the vanishing scattering for long-wavelength phonons. We show that this thermal transport improvement also appears in nanowires as their diameter is decreased below D?=?5?nm (not only as the length increases), originating from the increase in the density of the long wavevector modes. The observation is present under ballistic transport conditions, and further enhanced with the introduction of phonon-phonon scattering. Because of this, in such ultra-narrow nanowires, as the diameter is reduced, phonon transport is dominated more and more by lower energy phonons with longer mean-free paths. We show that ?80% of the heat is carried by phonons with energies less than 5?meV, most with mean-free paths of several hundreds of nanometers.

  8. si

    Office of Legacy Management (LM)

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  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. Magnetic and transport properties of amorphous Tb-Si alloys near the metal-insulator transition M. Liu and F. Hellman

    E-Print Network [OSTI]

    Hellman, Frances

    Magnetic and transport properties of amorphous Tb-Si alloys near the metal-insulator transition M; revised manuscript received 18 November 2002; published 4 February 2003 The magnetic and transport as a function of temperature. The spin-glass freezing seen in amorphous Gd-Si alloys is drastically affected

  11. Static and high-frequency hole transport in p-Si/SiGe heterostructures in the ultra-quantum limit.

    SciTech Connect (OSTI)

    Drichko, I. L.; Smirnov, I. Yu.; Suslov, A. V.; Galperin, Y. M.; Vinokur, V.; Myronov, M.; Mironov, O. A.; Materials Science Division; A.F. Ioffe Physico-Technical Inst. of Russian Academy of Sciences; National High Magnetic Field Lab.; Univ. Oslo; Musashi Inst. of Tech.; Univ. Warwick; International Lab. of High Magnetic Fields and Low Temperature

    2007-10-01T23:59:59.000Z

    Complex high-frequency (HF), {sigma}{sup AC} = {sigma}{sub 1} - i{sigma}{sub 2}, and static, {sigma}{sup DC}, conductivities, as well as current-voltage characteristics, have been measured in p-Si/SiGe heterostructures with a low hole density (p = 8.2 x 10{sup 10} cm{sup -2}) at temperatures T = 0.3-4.2 K in the ultraquantum limit, when the filling factor is v < 1. In order to determine the components of the HF conductivity, the acoustic contactless method in the 'hybrid configuration' is used, when the surface acoustic wave propagates on the surface of the LiNbO{sub 3} piezoelectric and the heterostructure is pressed to the surface by a spring. The conductivities {sigma}{sub 1} and {sigma}{sub 2} are determined from the damping and velocity of the surface acoustic waves that are measured simultaneously with varying the magnetic field. The revealed HF conductivity features - {sigma}{sub 1} >> |{sigma}{sub 2}|, the negative sign of {sigma}{sub 2}, the threshold behavior of the current-voltage characteristic, and the dependence I {proportional_to} exp(-A/V{sup 0.3}) in the subthreshold region - indicate the formation of a pinned Wigner crystal (glass) in the ultraquantum limit (T = 0.3-0.8 K, B > 14 T).

  12. Two-color optical technique for characterization of x-ray radiation-enhanced electron transport in SiO2

    E-Print Network [OSTI]

    Pantelides, Sokrates T.

    Two-color optical technique for characterization of x-ray radiation-enhanced electron transport the oxide.2 Presently, characterization of radiation damage in Si/SiO2 systems is usually accomplished used to provide additional insight into radiation damage in ultrathin oxides.3 These measure- ments

  13. Magneto-transport properties of oriented Mn{sub 2}CoAl films sputtered on thermally oxidized Si substrates

    SciTech Connect (OSTI)

    Xu, G. Z.; Du, Y.; Zhang, X. M.; Liu, E. K.; Wang, W. H., E-mail: wenhong.wang@iphy.ac.cn; Wu, G. H. [State Key Laboratory for Magnetism, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Zhang, H. G. [College of Materials Science and Engineering, Beijing University of Technology, Beijing 100124 (China)

    2014-06-16T23:59:59.000Z

    Spin gapless semiconductors are interesting family of materials by embracing both magnetism and semiconducting due to their unique band structure. Its potential application in future spintronics requires realization in thin film form. In this Letter, we report fabrication and transport properties of spin gapless Mn{sub 2}CoAl films prepared on thermally oxidized Si substrates by magnetron sputtering deposition. The films deposited at 673?K are well oriented to (001) direction and display a uniform-crystalline surface. Magnetotransport measurements on the oriented films reveal a semiconducting-like resistivity, small anomalous Hall conductivity, and linear magnetoresistance representative of the transport signatures of spin gapless semiconductors. The magnetic properties of the films have also been investigated and compared to that of bulk Mn{sub 2}CoAl, showing small discrepancy induced by the composition deviation.

  14. Enhanced Hole Transport in Short-Channel Strained-SiGe p-MOSFETs

    E-Print Network [OSTI]

    Gomez, Leonardo

    Hole mobility and velocity are extracted from scaled strained-Si[subscript 0.4]5Ge[subscript 0.55]channel p-MOSFETs on insulator. Devices have been fabricated with sub-100-nm gate lengths, demonstrating hole mobility and ...

  15. AC transport in p-Ge/GeSi quantum well in high magnetic fields

    SciTech Connect (OSTI)

    Drichko, I. L.; Malysh, V. A.; Smirnov, I. Yu.; Golub, L. E.; Tarasenko, S. A. [A.F. Ioffe Physical Technical Institute of Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation); Suslov, A. V. [National High Magnetic Field Laboratory, Tallahassee, FL 32310 (United States); Mironov, O. A. [Warwick SEMINANO R and D Center, University of Warwick Science Park, Coventry CV4 7EZ (United Kingdom); Kummer, M.; Känel, H. von [Laboratorium für Festkörperphysik ETH Zürich, CH-8093 Zürich (Switzerland)

    2014-08-20T23:59:59.000Z

    The contactless surface acoustic wave technique is implemented to probe the high-frequency conductivity of a high-mobility p-Ge/GeSi quantum well structure in the regime of integer quantum Hall effect (IQHE) at temperatures 0.3–5.8 K and magnetic fields up to 18 T. It is shown that, in the IQHE regime at the minima of conductivity, holes are localized and ac conductivity is of hopping nature and can be described within the “two-site” model. The analysis of the temperature and magnetic-field-orientation dependence of the ac conductivity at odd filing factors enables us to determine the effective hole g-factor, |g{sub zz}|?4.5. It is shown that the in-plane component of the magnetic field leads to a decrease in the g-factor as well as increase in the cyclotron mass, which is explained by orbital effects in the complex valence band of germanium.

  16. 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.

  17. Transportation

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    Transportation Home Agenda Awards Exhibitors Lodging Posters Registration Transportation Workshops Contact Us User Meeting Archives Users' Executive Committee Getting to Berkeley...

  18. Transportation

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

    Transportation Print Home Agenda Awards Exhibitors Lodging Posters Registration Transportation Workshops Contact Us User Meeting Archives Users' Executive Committee Getting to...

  19. Dependence of dynamic magnetization and magneto-transport properties of FeAlSi films with oblique sputtering studied via spin rectification effect

    SciTech Connect (OSTI)

    Soh, Wee Tee; Ong, C. K. [Department of Physics, Center for Superconducting and Magnetic Materials, National University of Singapore, 2 Science Drive 3, Singapore 117551 (Singapore); Zhong, Xiaoxi, E-mail: xiaoxi.zhong@gmail.com [Department of Physics, Center for Superconducting and Magnetic Materials, National University of Singapore, 2 Science Drive 3, Singapore 117551 (Singapore); School of Materials Science and Engineering, Sichuan University, Chengdu 610065 (China)

    2014-09-15T23:59:59.000Z

    FeAlSi (Sendust) is known to possess excellent soft magnetic properties comparable to traditional soft magnetic alloys such as NiFe (Permalloy), while having a relatively higher resistance for lower eddy current losses. However, their dynamic magnetic and magneto-transport properties are not well-studied. Via the spin rectification effect, we electrically characterize a series of obliquely sputtered FeAlSi films at ferromagnetic resonance. The variations of the anisotropy fields and damping with oblique angle are extracted and discussed. In particular, two-magnon scattering is found to dominate the damping behavior at high oblique angles. An analysis of the results shows large anomalous Hall effect and anisotropic magneto-resistance across all samples, which decreases sharply with increasing oblique incidence.

  20. Control of morphology for enhanced electronic transport in PECVD-grown a-Si : H Thin Films

    E-Print Network [OSTI]

    Castro Galnares, Sebastián

    2010-01-01T23:59:59.000Z

    Solar cells have become an increasingly viable alternative to traditional, pollution causing power generation methods. Although crystalline silicon (c-Si) modules make up most of the market, thin films such as hydrogenated ...

  1. Transportation

    E-Print Network [OSTI]

    Vinson, Steve

    2013-01-01T23:59:59.000Z

    Transportation in ancient Egypt entailed the use of boats2007 Land transport in Roman Egypt: A study of economics andDieter 1991 Building in Egypt: Pharaonic stone masonry. New

  2. Heteroepitaxial growth of GaN/Si (111) junctions in ammonia-free atmosphere: Charge transport, optoelectronic, and photovoltaic properties

    SciTech Connect (OSTI)

    Saron, K. M. A.; Hashim, M. R. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, Penang 11800 (Malaysia); Allam, Nageh K. [Energy Materials Laboratory (EML), Department of Physics, School of Sciences and Engineering, The American University in Cairo, New Cairo 11835 (Egypt)

    2013-03-28T23:59:59.000Z

    We report the catalyst-free growth of gallium nitride (GaN) nanostructures on n-Si (111) substrates using physical vapor deposition via thermal evaporation of GaN powder at 1150 Degree-Sign C in the absence of NH{sub 3} gas. Scanning electron microscopy and energy dispersive x-ray analysis indicate that the growth rate of GaN nanostructures varies with deposition time. Photoluminescence spectra showed the suppression of the UV emission and the enhancement of the visible band emission with increasing the deposition time. The fabricated GaN nanostructures exhibited p-type behavior at the GaN/Si interface, which can be related to the diffusion of Ga into the Si substrate. The obtained lowest reflection and highest transmittance over a wide wavelength range (450-750 nm) indicate the high quality of the fabricated GaN films. Hall-effect measurements showed that all fabricated films have p-type behavior with decreasing electron concentration from 10{sup 21} to 10{sup 12} cm{sup -3} and increasing the electron mobility from 50 to 225 cm{sup 2}/V s with increasing the growth time. The fabricated solar cell based on the 1 h-deposited GaN nanostructures on n-Si (111) substrate showed a well-defined rectifying behavior with a rectification ratio larger than 8.32 Multiplication-Sign 10{sup 3} in dark. Upon illumination (30 mW/cm{sup 2}), the 1 h-deposited heterojunction solar cell device showed a conversion efficiency of 5.78%. The growth of GaN in the absence of NH{sub 3} gas has strong effect on the morphological, optical, and electrical properties and consequently on the efficiency of the solar cell devices made of such layers.

  3. Single-electron quantum dot in Si/SiGe with integrated charge sensing C. B. Simmons,a

    E-Print Network [OSTI]

    Coppersmith, Susan N.

    Single-electron quantum dot in Si/SiGe with integrated charge sensing C. B. Simmons,a Madhu that are important for quantum information processing. Si/SiGe is of interest for semiconductor spin qubits and measurement of a top-gated quantum dot occupied by a single electron in a Si/SiGe heterostructure. Transport

  4. FRV USA formerly Fotowatio Renewable Ventures LLC | Open Energy Information

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  5. FRV formerly Fotowatio Energia Solar SL | 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 being directedAnnualPropertyd8c-a9ae-f8521cbb8489 NoEurope BV Jump to:FASFMI-HDFRED Type Term Title Author

  6. Modeling analysis of core-shell Si/SiGe nanowires

    E-Print Network [OSTI]

    Tang, Ming Y., 1979-

    2004-01-01T23:59:59.000Z

    (cont.) a composition that results in a high mobility has a very promising thermoelectric performance. Lastly, the thermoelectric-related transport properties for a Si/SiGe core-shell nanowire are compared with the related ...

  7. Behavior of Si and C atoms in ion amorphized SiC. | EMSL

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

    analysis. Neither Si nor C in the amorphized SiC exhibits a significant mass transport by diffusion during the irradiation and subsequent storage at room temperature. There is no...

  8. A low cost network of spectrometer radiation detectors based on the ArduSiPM a compact transportable Software/Hardware Data Acquisition system with Arduino DUE

    E-Print Network [OSTI]

    Bocci, Valerio; Iacoangeli, Francesco; Nuccetelli, Massimo; Recchia, Luigi

    2015-01-01T23:59:59.000Z

    The necessity to use Photo Multipliers (PM) as light detector limited in the past the use of crystals in radiation handled device preferring the Geiger approach. The Silicon Photomultipliers (SiPMs) are very small and cheap, solid photon detectors with good dynamic range and single photon detection capability, they are usable to supersede in some application cumbersome and difficult to use Photo Multipliers (PM). A SiPM can be coupled with a scintillator crystal to build efficient, small and solid radiation detector. A cost effective and easily replicable Hardware software module for SiPM detector readout is made using the ArduSiPM solution [1]. The ArduSiPM is an easily battery operable handled device using an Arduino DUE (an open Software/Hardware board) as processor board and a piggy-back custom designed board (ArduSiPM Shield), the Shield contains all the blocks features to monitor, set and acquire the SiPM using internet network.

  9. Electrostatically defined quantum dots in a Si/SiGe heterostructure This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Ludwig-Maximilians-Universität, München

    Electrostatically defined quantum dots in a Si/SiGe heterostructure This article has been of Physics Electrostatically defined quantum dots in a Si/SiGe heterostructure A Wild1 , J Sailer1 , J Nützel epitaxially grown Si/SiGe heterostructure. Transport and charge spectroscopy with an additional QD as well

  10. arXiv:1007.2404v1[cond-mat.mes-hall]14Jul2010 Electrostatically defined Quantum Dots in a Si/SiGe

    E-Print Network [OSTI]

    Ludwig-Maximilians-Universität, München

    arXiv:1007.2404v1[cond-mat.mes-hall]14Jul2010 Electrostatically defined Quantum Dots in a Si/SiGe (QD) realized in a molecular beam epitaxy grown Si/SiGe heterostructure. Transport and charge as a spin qubit. Our results promise the suitability of electrostatically defined QDs in Si/SiGe

  11. Magnetic Properties of Single-Crystalline CoSi Nanowires

    E-Print Network [OSTI]

    Kim, Bongsoo

    Si nanowires with B20 crystal structure are synthesized by a vapor-transport-based method. The reaction-cooled (ZFC-FC) measurements from the nanowire ensemble show freezing of the disordered surface spins at low and electrical transport properties.1 While MnSi shows low- temperature helimagnetic order,2 FeSi is a small

  12. Depth profile reconstructions of electronic transport properties in H{sup +} MeV-energy ion-implanted n-Si wafers using photocarrier radiometry

    SciTech Connect (OSTI)

    Tai, Rui; Wang, Chinhua, E-mail: chinhua.wang@suda.edu.cn; Hu, Jingpei [Institute of Modern Optical Technologies and Collaborative Innovation Center of Suzhou Nano Science and Technology, Jiangsu Key Lab of Advanced Optical Manufacturing Technologies and MOE Key Lab of Modern Optical Technologies, Soochow University, Suzhou 215006 (China); Mandelis, Andreas [Center for Advanced Diffusion-Wave Technologies, Department of Mechanical and Industrial Engineering, University of Toronto, Ontario M5S 3G8 (Canada)

    2014-07-21T23:59:59.000Z

    A depth profiling technique using photocarrier radiometry (PCR) is demonstrated and used for the reconstruction of continuously varying electronic transport properties (carrier lifetime and electronic diffusivity) in the interim region between the ion residence layer and the bulk crystalline layer in H{sup +} implanted semiconductor wafers with high implantation energies (?MeV). This defect-rich region, which is normally assumed to be part of the homogeneous “substrate” in all existing two- and three-layer models, was sliced into many virtual thin layers along the depth direction so that the continuously and monotonically variable electronic properties across its thickness can be considered uniform within each virtual layer. The depth profile reconstruction of both carrier life time and diffusivity in H{sup +} implanted wafers with several implantation doses (3?×?10{sup 14}, 3?×?10{sup 15}, and 3?×?10{sup 16}?cm{sup ?2}) and different implantation energies (from 0.75 to 2.0?MeV) is presented. This all-optical PCR method provides a fast non-destructive way of characterizing sub-surface process-induced electronic defect profiles in devices under fabrication at any intermediate stage before final metallization and possibly lead to process correction and optimization well before electrical testing and defect diagnosis becomes possible.

  13. Electrostatically defined Quantum Dots in a Si/SiGe Heterostructure

    E-Print Network [OSTI]

    A. Wild; J. Sailer; J. Nützel; G. Abstreiter; S. Ludwig; D. Bougeard

    2010-07-14T23:59:59.000Z

    We present an electrostatically defined few-electron double quantum dot (QD) realized in a molecular beam epitaxy grown Si/SiGe heterostructure. Transport and charge spectroscopy with an additional QD as well as pulsed-gate measurements are demonstrated. We discuss technological challenges specific for silicon-based heterostructures and the effect of a comparably large effective electron mass on transport properties and tunability of the double QD. Charge noise, which might be intrinsically induced due to strain-engineering is proven not to affect the stable operation of our device as a spin qubit. Our results promise the suitability of electrostatically defined QDs in Si/SiGe heterostructures for quantum information processing.

  14. Electrostatically defined Quantum Dots in a Si/SiGe Heterostructure

    E-Print Network [OSTI]

    Wild, A; Nützel, J; Abstreiter, G; Ludwig, S; Bougeard, D

    2010-01-01T23:59:59.000Z

    We present an electrostatically defined few-electron double quantum dot (QD) realized in a molecular beam epitaxy grown Si/SiGe heterostructure. Transport and charge spectroscopy with an additional QD as well as pulsed-gate measurements are demonstrated. We discuss technological challenges specific for silicon-based heterostructures and the effect of a comparably large effective electron mass on transport properties and tunability of the double QD. Charge noise, which might be intrinsically induced due to strain-engineering is proven not to affect the stable operation of our device as a spin qubit. Our results promise the suitability of electrostatically defined QDs in Si/SiGe heterostructures for quantum information processing.

  15. Valley splitting theory of SiGe/Si/SiGe quantum wells Mark Friesen,1,

    E-Print Network [OSTI]

    Coppersmith, Susan N.

    Valley splitting theory of SiGe/Si/SiGe quantum wells Mark Friesen,1, * Sucismita Chutia,1 Charles an effective mass theory for SiGe/Si/SiGe quantum wells, with an emphasis on calculating the valley splitting interface, with characteristic energy splittings of order 0.1­1 meV for the case of SiGe/Si/SiGe quantum

  16. Resonant tunneling with high peak to valley current ratio in SiO{sub 2}/nc-Si/SiO{sub 2} multi-layers at room temperature

    SciTech Connect (OSTI)

    Chen, D. Y., E-mail: cdy7659@126.com [Department of Physics, Nanjing National Laboratory of Microstructures and Key Laboratory of Advanced Photonic and Electronic, materials, Nanjing University, Nanjing 210093 (China); Nanjing University of posts and Telecommunications, Nanjing 210046 (China); Sun, Y.; He, Y. J. [Nanjing University of posts and Telecommunications, Nanjing 210046 (China); Xu, L.; Xu, J. [Department of Physics, Nanjing National Laboratory of Microstructures and Key Laboratory of Advanced Photonic and Electronic, materials, Nanjing University, Nanjing 210093 (China)

    2014-01-28T23:59:59.000Z

    We have investigated carrier transport in SiO{sub 2}/nc-Si/SiO{sub 2} multi-layers by room temperature current-voltage measurements. Resonant tunneling signatures accompanied by current peaks are observed. Carrier transport in the multi-layers were analyzed by plots of ln(I/V{sup 2}) as a function of 1/V and ln(I) as a function of V{sup 1/2}. Results suggest that besides films quality, nc-Si and barrier sub-layer thicknesses are important parameters that restrict carrier transport. When thicknesses are both small, direct tunneling dominates carrier transport, resonant tunneling occurs only at certain voltages and multi-resonant tunneling related current peaks can be observed but with peak to valley current ratio (PVCR) values smaller than 1.5. When barrier thickness is increased, trap-related and even high field related tunneling is excited, causing that multi-current peaks cannot be observed clearly, only one current peak with higher PVCR value of 7.7 can be observed. While if the thickness of nc-Si is large enough, quantum confinement is not so strong, a broad current peak with PVCR value as high as 60 can be measured, which may be due to small energy difference between the splitting energy levels in the quantum dots of nc-Si. Size distribution in a wide range may cause un-controllability of the peak voltages.

  17. SiNode Systems

    Broader source: Energy.gov [DOE]

    SiNode Systems is a battery materials venture developing silicon-graphene anodes for the next generation of lithium-ion batteries. SiNode anodes offer higher battery capacity and faster charging rates, all while being produced via a low cost solution chemistry-based manufacturing process.

  18. Si Wu | EMSL

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

    Si Wu d3p754 Primary tabs View(active tab) Track Si Wu Staff Member Title: Scientist Address: P.O. Box 999 K8-98 City: Richland State: WA Zip Code: 99352 Phone: (509) 371-6325...

  19. GeSi intermixing in Ge quantum dots on Si,,001... and Si,,111... F. Boscherinia)

    E-Print Network [OSTI]

    Ge­Si intermixing in Ge quantum dots on Si,,001... and Si,,111... F. Boscherinia) Laboratori December 1999 Exploiting Ge K-edge x-ray absorption spectroscopy we provide direct evidence of Si­Ge intermixing in self-organized strained and unstrained Ge quantum dots on Si, and provide a quantitative

  20. Gas-phase transport of WF6 through annular nanopipes in TiN during chemical vapor deposition of W on TiN/Ti/SiO2 structures for integrated

    E-Print Network [OSTI]

    Allen, Leslie H.

    Gas-phase transport of WF6 through annular nanopipes in TiN during chemical vapor deposition of W through the 106-nm-thick TiN film. W piles up at the TiN/Ti interface, while F rapidly saturates the TiN-sectional and scanning transmission electron microscopy analyses demonstrate that WF6 penetrates into the TiN layer

  1. Local Transportation

    E-Print Network [OSTI]

    Local Transportation. Transportation from the Airport to Hotel. There are two types of taxi companies that operate at the airport: special and regular taxis (

  2. Greening Transportation

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

    Transportation Goal 2: Greening Transportation LANL supports and encourages employees to reduce their personal greenhouse gas emissions by offering various commuting and work...

  3. Chamber transport

    SciTech Connect (OSTI)

    OLSON,CRAIG L.

    2000-05-17T23:59:59.000Z

    Heavy ion beam transport through the containment chamber plays a crucial role in all heavy ion fusion (HIF) scenarios. Here, several parameters are used to characterize the operating space for HIF beams; transport modes are assessed in relation to evolving target/accelerator requirements; results of recent relevant experiments and simulations of HIF transport are summarized; and relevant instabilities are reviewed. All transport options still exist, including (1) vacuum ballistic transport, (2) neutralized ballistic transport, and (3) channel-like transport. Presently, the European HIF program favors vacuum ballistic transport, while the US HIF program favors neutralized ballistic transport with channel-like transport as an alternate approach. Further transport research is needed to clearly guide selection of the most attractive, integrated HIF system.

  4. Effects of Interface Disorder on Valley Splitting in SiGe/Si/SiGe Quantum Wells

    E-Print Network [OSTI]

    Zhengping Jiang; Neerav Kharche; Timothy Boykin; Gerhard Klimeck

    2012-03-06T23:59:59.000Z

    A sharp potential barrier at the Si/SiGe interface introduces valley splitting (VS), which lifts the 2-fold valley degeneracy in strained SiGe/Si/SiGe quantum wells (QWs). This work examines in detail the effects of Si/SiGe interface disorder on the VS in an atomistic tight binding approach based on statistical sampling. VS is analyzed as a function of electric field, QW thickness, and simulation domain size. Strong electric fields push the electron wavefunctions into the SiGe buffer and introduce significant VS fluctuations from device to device. A Gedankenexperiment with ordered alloys sheds light on the importance of different bonding configurations on VS. We conclude that a single SiGe band offset and effective mass cannot comprehend the complex Si/SiGe interface interactions that dominate VS.

  5. Effects of Interface Disorder on Valley Splitting in SiGe/Si/SiGe Quantum Wells

    E-Print Network [OSTI]

    Jiang, Zhengping; Boykin, Timothy; Klimeck, Gerhard

    2011-01-01T23:59:59.000Z

    A sharp potential barrier at the Si/SiGe interface introduces valley splitting (VS), which lifts the 2-fold valley degeneracy in strained SiGe/Si/SiGe quantum wells (QWs). This work examines in detail the effects of Si/SiGe interface disorder on the VS in an atomistic tight binding approach based on statistical sampling. VS is analyzed as a function of electric field, QW thickness, and simulation domain size. Strong electric fields push the electron wavefunctions into the SiGe buffer and introduce significant VS fluctuations from device to device. A Gedankenexperiment with ordered alloys sheds light on the importance of different bonding configurations on VS. We conclude that a single SiGe band offset and effective mass cannot comprehend the complex Si/SiGe interface interactions that dominate VS.

  6. X-Ray And Polarized Neutron Reflectometry: Characterization Of Si/Co/Si And Si/Ni/Si Systems

    SciTech Connect (OSTI)

    Bhattacharya, Debarati; Basu, Saibal [Solid State Physics Division, Bhabha Atomic Research Center, Mumbai, Maharastra 400085 (India); Poswal, A. K. [Applied Spectroscopy Division, Bhabha Atomic Research Center, Mumbai, Maharastra 400085 (India); Roy, S.; Dev, B. N. [Department of Materials Science, Indian Association for the Cultivation of Science, 2A and 2B Raja S. C. Mullick Road, Jadavpur, Kolkata 700032 (India)

    2010-12-01T23:59:59.000Z

    Technologically important metal silicides formed through interdiffusion in metal/Si systems has been probed using two complementary techniques viz. x-ray reflectivity (XRR) and polarized neutron reflectivity (PNR). Both structural and magnetic characterization with good depth resolution has been achieved in these systems. We have studied two systems Si/Co/Si and Si/Ni/Si which relate to important applications in ferromagnetic/ non-magnetic semiconductor layered structures for memory devices.

  7. Gated Si nanowires for large thermoelectric power factors Neophytos Neophytou1

    E-Print Network [OSTI]

    1 Gated Si nanowires for large thermoelectric power factors Neophytos Neophytou1 and Hans Kosina2 1.Neophytou@warwick.ac.uk Abstract We investigate the effect of electrostatic gating on the thermoelectric power factor of p-type Si, coupled to linearized Boltzmann transport equation for the calculation of the thermoelectric coefficients

  8. A Transport Synthetic Acceleration method for transport iterations

    E-Print Network [OSTI]

    Ramone, Gilles Lionel

    1996-01-01T23:59:59.000Z

    - symmetric high quadrature set, c=0. 99, P = 0. 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 Maximum scatering ratio for stability of the Larsen & Miller method. S? IS? level-symmetric quadrature sets. Spectral radius vs. mesh size.... . . . . . . . . TSA computational gain over SI for an heterogeneous medium. Ss/S, quadrature sets. c=0. 99, P = 0. 2, N. ?. ? 7, . . . . , . . . . . . . . . , . . . . 58 59 60 61 62 64 CHAPTER I INTRODUCTION Transport theory covers a wide range of physical...

  9. Reliability implications of defects in high temperature annealed Si/SiO{sub 2}/Si structures

    SciTech Connect (OSTI)

    Warren, W.L.; Fleetwood, D.M.; Shaneyfelt, M.R.; Winokur, P.S. [Sandia National Labs., Albuquerque, NM (United States); Devine, R.A.B.; Mathiot, D. [France Telecom/CNET, Meylan (France); Wilson, I.H.; Xu, J.B. [Chinese Univ. of Hong Kong (Hong Kong)

    1994-08-01T23:59:59.000Z

    High-temperature post-oxidation annealing of poly-Si/SiO{sub 2}/Si structures such as metal-oxide-semiconductor capacitors and metal-oxide-semiconductor field effect transistors is known to result in enhanced radiation sensitivity, increased 1/f noise, and low field breakdown. The authors have studied the origins of these effects from a spectroscopic standpoint using electron paramagnetic resonance (EPR) and atomic force microscopy. One result of high temperature annealing is the generation of three types of paramagnetic defect centers, two of which are associated with the oxide close to the Si/SiO{sub 2} interface (oxygen-vacancy centers) and the third with the bulk Si substrate (oxygen-related donors). In all three cases, the origin of the defects may be attributed to out-diffusion of O from the SiO{sub 2} network into the Si substrate with associated reduction of the oxide. The authors present a straightforward model for the interfacial region which assumes the driving force for O out-diffusion is the chemical potential difference of the O in the two phases (SiO{sub 2} and the Si substrate). Experimental evidence is provided to show that enhanced hole trapping and interface-trap and border-trap generation in irradiated high-temperature annealed Si/SiO{sub 2}/Si systems are all related either directly, or indirectly, to the presence of oxygen vacancies.

  10. Strain-induced self-assembly of Ge nanodashes, nanodumbbells, and dot chains on Si(001)

    SciTech Connect (OSTI)

    Zhang, J. J. [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany) [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany); Centre for Quantum Computation and Communication Technology, School of Physics, University of New South Wales, Sydney, New South Wales 2052 (Australia); Schmidt, O. G. [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany) [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, 01069 Dresden (Germany); Center for Advancing Electronics Dresden, TU Dresden (Germany)

    2013-09-30T23:59:59.000Z

    We investigate the growth of self-assembled Ge nanostructures on top of embedded Ge nanowires on Si(001) substrates. Ge nanostructures, such as nanodashes, nanodumbbells, and dot chains are observed simply by tuning the growth temperature and thickness of the Si spacer between the Ge layers. The self-assembly process is governed by the surface strain fields generated by the embedded Ge nanowires and is well-described by our theoretical calculations. The catalyst-free and horizontal growth of such Ge nanostructures directly on Si(001) is attractive for investigating exotic transport properties through Si/Ge-based quantum devices.

  11. Near interface oxide degradation in high temperature annealed Si/SiO{sub 2}/Si structures

    SciTech Connect (OSTI)

    Devine, R.A.B.; Mathiot, D. [Centre National d`Etudes des Telecommunications (CNET), 38 - Meylan (France); Warren, W.L.; Fleetwood, D.M. [Sandia National Labs., Albuquerque, NM (United States)

    1993-12-31T23:59:59.000Z

    Degradation of 430 nm thick SiO{sub 2} layers in Si/SiO{sub 2}/Si structures which results from high temperature annealing (1320 C) has been studied using electron spin resonance, infra-red and refractive index measurements. Large numbers of oxygen vacancies are found in a region {le}100 nm from each Si/SiO{sub 2} interface. Two types of paramagnetic defects are observed following {gamma} or x-irradiation or hole injection. The 1106 cm{sup {minus}1} infra-red absorption associated with O interstitials in the Si substrate is found to increase with annealing time. The infra-red and spin resonance observations can be explained qualitatively and quantitatively in terms of a model in which oxygen atoms are gettered from the oxide into the under or overlying Si, the driving force being the increased O solubility limit associated with the anneal temperature.

  12. Tailoring of a metastable material: alfa-FeSi2 thin film

    SciTech Connect (OSTI)

    Cao, Guixin [ORNL; Singh, David J [ORNL; Zhang, Xiaoguang [ORNL; Samolyuk, German D [ORNL; Qiao, Liang [ORNL; Parish, Chad M [ORNL; Ke, Jin [The University of Tennessee; Zhang, Yanwen [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Guo, Hangwen [ORNL; Tang, Siwei [ORNL; Wang, Wenbin [ORNL; Yi, Jieyu [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Cantoni, Claudia [ORNL; Siemons, Wolter [ORNL; Payzant, E Andrew [ORNL; Biegalski, Michael D [ORNL; Ward, Thomas Zac [ORNL; Sales, Brian C [ORNL; Mandrus, D. [University of Tennessee (UTK) and Oak Ridge National Laboratory (ORNL); Stocks, George Malcolm [ORNL; Gai, Zheng [ORNL

    2015-01-01T23:59:59.000Z

    The epitaxially stabilized metallic -FeSi2 thin films on Si(001) were grown using pulsed laser deposition. While the bulk material of -FeSi2 is a high temperature metastable phase and nonmagnetic, the thin film is stabilized at room temperature and shows unusual electronic transport and magnetic properties due to strain modification. The transport renders two different conducting states with a strong crossover at 50 K accompanied by an onset of ferromagnetism as well as a substantial magnetocaloric effect and magnetoresistance. These experimental results are discussed in terms of the unusual electronic structure of -FeSi2 obtained within density functional calculations and Boltzmann transport calculations with and without strain. Our findings provide an example of a tailored material with interesting physics properties for practical applications.

  13. Diffusion in SiGe and Ge

    E-Print Network [OSTI]

    Liao, Christopher Yuan Ting

    2010-01-01T23:59:59.000Z

    Claeys, et al. , "Si versus Ge for future microelectronics,"in Selectively Doped Si/Si x Ge 1-x Superlattices," PhysicalA. Fitzgerald, et al. , "Relaxed Ge x Si 1-x structures for

  14. Diffusion in SiGe and Ge

    E-Print Network [OSTI]

    Liao, Christopher Yuan Ting

    2010-01-01T23:59:59.000Z

    High-electron-mobility Si/SiGe heterostructures: influenceof the relaxed SiGe buffer layer," Semiconductor Science andFrom its discovery to SiGe devices," Materials Science in

  15. Tunable, long-wavelength PtSi/SiGe/Si Schottky diode infrared detectors J. R. Jimeneza)

    E-Print Network [OSTI]

    Tunable, long-wavelength PtSi/SiGe/Si Schottky diode infrared detectors J. R. Jimeneza) Faura, Massachusetts 01731 Received 9 March 1995; accepted for publication 31 May 1995 We have fabricated p-type PtSi/SiGe dependent on the applied bias. The variability in the barrier height is obtained by using the SiGe

  16. Computational Transportation

    E-Print Network [OSTI]

    Illinois at Chicago, University of

    ), in-vehicle computers, and computers in the transportation infrastructure are integrated ride- sharing, real-time multi-modal routing and navigation, to autonomous/assisted driving

  17. Evidence of impurity assisted tunneling in SiGe/Si heterostructures

    SciTech Connect (OSTI)

    Zhukavin, R. Kh.; Bekin, N. A.; Lobanov, D. N.; Drozdov, M. N.; Drozdov, Yu. N.; Kozlov, D. V.; Pryakhin, D. A.; Shastin, V. N. [Institute for Physics of Microstructures RAS, 603950, Nizhny Novgorod, GSP-105 (Russian Federation); Shengurov, V. G. [Nizhny Novgorod State University, 603950, Nizhny Novgorod, Gagarina avenue, 23 (Russian Federation)

    2013-12-04T23:59:59.000Z

    The investigation of vertical transport in delta-doped SiGe/Si heterostructures has been presented. The asymmetrical triple barrier structure was grown by MBE technique. The delta layer of boron impurity was placed into the center of narrower quantum well. The growth procedure was followed by conventional processing including photolithography and plasma etching and magnetron sputtering. SIMS and X-rays diagnostics have been used to control the desired structure. The conductance of the structure has been measured at liquid helium temperature and analyzed. All pronounced resonances have been identified. The resonant feature near 60 mV has to be attributed to impurity-assisted tunneling that is supported by calculation of binding energy of the acceptor in the narrower quantum well.

  18. Progress in blanket designs using SiCf/SiC composites L. Giancarli a,

    E-Print Network [OSTI]

    Raffray, A. René

    Progress in blanket designs using SiCf/SiC composites L. Giancarli a, 1, H. Golfier b , S. Nishio c the use of SiCf/SiC composite as structural material for fusion power reactor breeding blanket. SeveralCf/SiC. # 2002 Published by Elsevier Science B.V. Keywords: Blanket designs; SiCf/SiC composites; Self

  19. Crack formation in GaAs heteroepitaxial films on Si and SiGe virtual substrates

    E-Print Network [OSTI]

    Crack formation in GaAs heteroepitaxial films on Si and SiGe virtual substrates V. K. Yang, MAs films grown on Si and SiGe virtual substrates analytically and experimentally. The analytical model­10 Relaxed SiGe graded layers on Si have produced the highest quality GaAs on Si to date for the integration

  20. University of California and HRL Laboratories, LLC. All rights reserved. SiGe/Si SUPERLATTICE COOLERS

    E-Print Network [OSTI]

    © University of California and HRL Laboratories, LLC. All rights reserved. SiGe/Si SUPERLATTICE and characterization of SiGe/Si superlattice coolers are described. Superlattice structures were used to enhance for SiGe/Si superlattice coolers. SiGe is a good thermoelectric material for high temperature

  1. Si/SiGe modulation-doped structures with thin buffer layers: Effect of substrate orientation

    E-Print Network [OSTI]

    Allen, Leslie H.

    Si/SiGe modulation-doped structures with thin buffer layers: Effect of substrate orientation G. L and Nomarski microscopy. In n-type modulation-doped Si-SiGe structures, the band structure is type II where SiGe layer, generally on top of the strained Si, is intentionally doped leaving the adjacent Si layer

  2. Transportation Market Distortions

    E-Print Network [OSTI]

    Litman, Todd

    2006-01-01T23:59:59.000Z

    of Highways, Volpe National Transportation Systems Center (Evaluating Criticism of Transportation Costing, VictoriaFrom Here: Evaluating Transportation Diversity, Victoria

  3. Axial SiGe Heteronanowire Tunneling Field-Effect Transistors

    SciTech Connect (OSTI)

    Le, Son T.; Jannaty, P.; Luo, Xu; Zaslavsky, A.; Perea, Daniel E.; Dayeh, Shadi A.; Picraux, Samuel T.

    2012-10-31T23:59:59.000Z

    We present silicon-compatible tri-gated p-Ge/i-Si/n-Si axial heteronanowire tunneling field-effect transistors (TFETs), where on-state tunneling occurs in the Ge drain section, while off-state leakage is dominated by the Si junction in the source. Our TFETs have high ION ~ 2 µA/µm, fully suppressed ambipolarity, and a sub-threshold slope SS ~ 140 mV/decade over 4 decades of current with lowest SS ~ 50 mV/decade. Device operation in the tunneling mode is confirmed by three-dimensional TCAD simulation. Interestingly, in addition to the TFET mode, our devices work as standard nanowire FETs with good ION/IOFF ratio when the source-drain junction is forward-biased. The improved transport in both biasing modes confirms the benefits of utilizing bandgap engineered axial nanowires for enhancing device performance.

  4. Photoluminescence from electron-hole plasmas confined in Si/Si 1-,Ge,/Si quantum wells

    E-Print Network [OSTI]

    Photoluminescence from electron-hole plasmas confined in Si/Si 1-,Ge,/Si quantum wells X. Xiao, C 1992) We report the first observation of photoluminescence from electron-hole plasmas in Si/S&,sGe of the physical processes un- derlying luminescence in Si, -,GeX alloys, especially at high carrier densities

  5. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect (OSTI)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2003-01-01T23:59:59.000Z

    In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Processing of perovskites of LSC, LSF and LSCF composition for evaluation of mechanical properties as a function of environment are begun. The studies are to be in parallel with LSFCO composition to characterize the segregation of cations and slow crack growth in environmental conditions. La{sub 1-x}Sr{sub x}FeO{sub 3-d} has also been characterized for paramagnetic ordering at room temperature and the evolution of magnetic moments as a function of temperature are investigated. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport.

  6. electrifyingthefuture transportation

    E-Print Network [OSTI]

    Birmingham, University of

    electrifyingthefuture transportation The UK Government's carbon reduction strategy vehicles and the new Birmingham Science City Energy Systems Integration Laboratory (ESIL) will further enhance this work. The laboratory - unique within the UK and world leading - brings together cutting edge

  7. Electrical passivation of Si/SiGe/Si structures by 1-octadecene monolayers

    SciTech Connect (OSTI)

    Antonova, Irina V.; Soots, Regina A.; Guliaev, Mitrofan B.; Prinz, Victor Ya.; Kagan, Miron S.; Kolodzey, James [Institute of Semiconductor Physics, RAS, 13 Lavrentieva, Novosibirsk 630090 (Russian Federation); Institute of Radio Engineering and Electronics, RAS, 11 Mokhovaya, 125009 Moscow (Russian Federation); University of Delaware, Newark, Delaware 19716 (United States)

    2007-09-03T23:59:59.000Z

    The passivating effects of organic monolayers of 1-octadecene deposited onto the silicon surfaces of both n and p conductivities were studied for Si/SiGe/Si structures grown by molecular beam epitaxy and chemical vapor deposition. Measurements of the capacitance versus voltage and current versus voltage were made on structures covered with the organic monolayer and compared with unpassivated structures covered with native silicon dioxide. The results demonstrate that the organic passivation provides a decrease of surface charge and an increase of carrier concentration in the near-surface layers and/or the SiGe quantum wells.

  8. Serial and parallel Si, Ge, and SiGe direct-write with scanning...

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

    Serial and parallel Si, Ge, and SiGe direct-write with scanning probes and conducting stamps. Serial and parallel Si, Ge, and SiGe direct-write with scanning probes and conducting...

  9. Magnesium Silicate Dissolution Investigated by 29Si MAS, 1H-29Si...

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

    Silicate Dissolution Investigated by 29Si MAS, 1H-29Si CP MAS, 25Mg QCPMG, and 1H-25Mg CP QCPMG NMR. Magnesium Silicate Dissolution Investigated by 29Si MAS, 1H-29Si CP MAS, 25Mg...

  10. Postdoctoral Positions: Si/SiGe Quantum Dots and Quantum Computing Eriksson Group

    E-Print Network [OSTI]

    Saffman, Mark

    Postdoctoral Positions: Si/SiGe Quantum Dots and Quantum Computing Eriksson Group Department in the area of Si/SiGe quantum dots and quantum computing. Recent advances in our group include single

  11. Transport in thin-body MOSFETs fabricated in strained Si and strained Si/SiGe heterostructures on insulator

    E-Print Network [OSTI]

    Åberg, Ingvar

    2006-01-01T23:59:59.000Z

    The combination of channel mobility enhancement techniques such as strain engineering, with non-classical MOS device architectures, such as ultra-thin body or multiple-gate structures, offers the promise of maximizing ...

  12. Valley splitting in Si quantum dots embedded in SiGe S. Srinivasan,1,2

    E-Print Network [OSTI]

    Rokhinson, Leonid

    Valley splitting in Si quantum dots embedded in SiGe S. Srinivasan,1,2 G. Klimeck,1,2 and L. P subband.4 Recently, calculations predicted that valley splitting in nar- row few nanometers SiGe/Si/SiGe that prediction, which has been explained12 by the disorders of the Si/SiGe interface and in the SiGe buffer

  13. Synthesis and Characterization of Structured Si-Carbon Nanocomposite...

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

    nanoparticles with controlled size and synthesized Si-carbon composites, including Si-graphene and Si@hollow carbon. * Synthesized new polymer binders for Si-based anodes. *...

  14. Defects in Ge and Si caused by 1 MeV Si+ implantation*

    E-Print Network [OSTI]

    Florida, University of

    Defects in Ge and Si caused by 1 MeV Si+ implantation* D. P. Hickeya Department of Materials defect formation and evolution in the 001 Ge and Si wafers implanted with 1 MeV Si+ and 40 keV Si dissolve at the projected range for nonamorphizing implants into Si. However, in Ge, no 311 defect

  15. \\Development, implementation and veri cation of a physics-based Si/SiGe

    E-Print Network [OSTI]

    Paper I \\Development, implementation and veri#12;cation of a physics-based Si/SiGe HBT model and verification of a physics­based Si/SiGe HBT model for millimeter­wave non­ linear circuit simulations. S. Bruce thermal dependence has been developed for Si/SiGe HBTs. The model takes into account several effects

  16. Simulation of Si/SiGe Micro-Cooler by Thermal Quadrupoles Method Y. Ezzahri *(a)

    E-Print Network [OSTI]

    Simulation of Si/SiGe Micro-Cooler by Thermal Quadrupoles Method Y. Ezzahri *(a) , S. Dilhaire (a on thermal quadrupoles is presented to model the behavior of a single stage Si/SiGe micro-cooler in AC of the model with experimental reflectometry techniques is also presented. Performance of Si/SiGe micro

  17. Strained Si, SiGe, and Ge on-insulator: review of wafer bonding fabrication techniques

    E-Print Network [OSTI]

    Strained Si, SiGe, and Ge on-insulator: review of wafer bonding fabrication techniques Gianni was arranged by Prof. C.K. Maiti Abstract Techniques for fabricating strained Si, SiGe, and Ge on is presented, with a detailed discussion of wafer bonding approaches for strained Si, SiGe, and Ge on

  18. Development, implementation and verification of a physicsbased Si/SiGe

    E-Print Network [OSTI]

    Development, implementation and verification of a physics­based Si/SiGe HBT model for millimeter Abstract A physics­based large­signal model including thermal dependence has been developed for Si/SiGe HBTs. The model takes into account several effects that are important for the operation of Si/SiGe HBTs

  19. Block-by-Block Growth of Single-Crystalline Si/SiGe Superlattice

    E-Print Network [OSTI]

    Yang, Peidong

    Letters Block-by-Block Growth of Single-Crystalline Si/SiGe Superlattice Nanowires Yiying Wu, Rong-defined compositional profile along the wire axis. Single-crystalline nanowires with longitudinal Si/SiGe superlattice-crystalline nano- wires with Si/SiGe superlattice structure are obtained and thoroughly characterized using

  20. Development, implementation and verification of a physics-based Si/SiGe

    E-Print Network [OSTI]

    Development, implementation and verification of a physics-based Si/SiGe HBT model for millimeter Abstract A physics-based large-signal model including thermal dependence has been developed for Si/SiGe HBTs. The model takes into account several effects that are important for the operation of Si/SiGe HBTs

  1. Study of thermomechanical properties of Si/SiGe superlattices using femtosecond transient thermoreflectance technique

    E-Print Network [OSTI]

    Study of thermomechanical properties of Si/SiGe superlattices using femtosecond transient the thermomechanical properties of two Si/SiGe superlattices. A theoretical model is presented which agrees well-lattice vectors is smaller.8 In the experiments reported here we have applied a FTT technique to study two Si/SiGe

  2. EBIC characterization of strained Si/SiGe heterostructures

    SciTech Connect (OSTI)

    Yakimov, E. B. [Russian Academy of Sciences, Institute of Microelectronics Technology and High-Purity Materials (Russian Federation)], E-mail: yakimov@ipmt-hpm.ac.ru; Zhang, R. H.; Rozgonyi, G. A. [North Carolina State University, Department of Materials Science and Engineering (United States); Seacrist, M. [MEMC Electronic Materials (United States)

    2007-04-15T23:59:59.000Z

    Strained-Si/SiGe heterostructure is studied by EBIC. The effect of annealing at 800 deg. C is investigated. The EBIC images obtained at different beam energies are analyzed. The analysis of images obtained shows that misfit dislocation bunches in the graded SiGe layer could not explain the cross-hatch contrast dependence on E{sub b}. Therefore, at least a part of this contrast should be associated with other defects located closer to the depletion region. It is assumed that dislocation trails could play the role of such defects.

  3. Plasma hydrogenation of strained Si/SiGe/Si heterostructure for layer transfer without ion implantation

    SciTech Connect (OSTI)

    Shao Lin; Lin Yuan; Lee, J.K.; Jia, Q.X.; Wang Yongqiang; Nastasi, M.; Thompson, Phillip E.; Theodore, N. David; Chu, Paul K.; Alford, T.L.; Mayer, J.W.; Chen Peng; Lau, S.S. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Code 6812, Naval Research Laboratory, Washington, DC 20375-5347 (United States); Advanced Products Research and Development Laboratory, Freescale Semiconductor Inc., Tempe, Arizona 85284 (United States); Department of Physics and Materials Science, City University of Hong Kong, Hong Kong (China); Department of Chemical and Materials Engineering, Arizona State University, Tempe, Arizona 85287 (United States); University of California at San Diego, San Diego, California 92093 (United States)

    2005-08-29T23:59:59.000Z

    We have developed an innovative approach without the use of ion implantation to transfer a high-quality thin Si layer for the fabrication of silicon-on-insulator wafers. The technique uses a buried strained SiGe layer, a few nanometers in thickness, to provide H trapping centers. In conjunction with H plasma hydrogenation, lift-off of the top Si layer can be realized with cleavage occurring at the depth of the strained SiGe layer. This technique avoids irradiation damage within the top Si layer that typically results from ion implantation used to create H trapping regions in the conventional ion-cut method. We explain the strain-facilitated layer transfer as being due to preferential vacancy aggregation within the strained layer and subsequent trapping of hydrogen, which lead to cracking in a well controlled manner.

  4. XAFS study of local disorder in the a-GdxSi1x amorphous magnetic semiconductor D. Haskel,1

    E-Print Network [OSTI]

    Haskel, Daniel

    transport properties in the presence of disorder. It has been shown recently1 that a-GdxSi1 x exhibits Gd moments lead to a spin glass freezing at low temperatures ( 10 K) and suppression, as Gd clustering would strongly in- fluence our understanding of both transport and magnetization

  5. Composite oxygen ion transport element

    DOE Patents [OSTI]

    Chen, Jack C. (Getzville, NY); Besecker, Charles J. (Batavia, IL); Chen, Hancun (Williamsville, NY); Robinson, Earil T. (Mentor, OH)

    2007-06-12T23:59:59.000Z

    A composite oxygen ion transport element that has a layered structure formed by a dense layer to transport oxygen ions and electrons and a porous support layer to provide mechanical support. The dense layer can be formed of a mixture of a mixed conductor, an ionic conductor, and a metal. The porous support layer can be fabricated from an oxide dispersion strengthened metal, a metal-reinforced intermetallic alloy, a boron-doped Mo.sub.5Si.sub.3-based intermetallic alloy or combinations thereof. The support layer can be provided with a network of non-interconnected pores and each of said pores communicates between opposite surfaces of said support layer. Such a support layer can be advantageously employed to reduce diffusion resistance in any type of element, including those using a different material makeup than that outlined above.

  6. Transportation and its Infrastructure

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    40 pp. IEA, 2004c: Biofuels for Transport: An Internationalthe ACT Map scenario, transport biofuels production reachesestimates that biofuels’ share of transport fuel could

  7. Group velocities in coplanar strip transmission lines on Si and Si/SiO2 /Si substrates measured using differential electro-optic sampling

    E-Print Network [OSTI]

    Group velocities in coplanar strip transmission lines on Si and Si/SiO2 /Si substrates measured 1996; accepted for publication 26 August 1996 The group velocities in coplanar strip transmission lines-9 Velocity measurements have been previously carried out for coplanar transmission lines on a variety

  8. Hot-Wire Deposition of Hydrogenated Nanocrystalline SiGe Films for Thin-Film Si Based Solar Cells

    E-Print Network [OSTI]

    Deng, Xunming

    Hot-Wire Deposition of Hydrogenated Nanocrystalline SiGe Films for Thin-Film Si Based Solar Cells bandgap absorber in an a-Si/a-SiGe/nc-SiGe(nc- Si) triple-junction solar cell due to its higher optical in an a-Si based multiple- junction solar cell. 1. INTRODUCTION Narrow bandgap amorphous SiGe (a

  9. NREL: Transportation Research - Transportation and Hydrogen Newsletter...

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

    The Future of Sustainable Transportation This is the January 2015 issue of the Transportation and Hydrogen Newsletter. Illustration of an electric vehicle Illustration of an...

  10. Characteristics of phase nucleation and growth during oriented crystallization of alloys of the Si-TaSi/sub 2/ and Si-NbSi/sub 2/ eutectic systems

    SciTech Connect (OSTI)

    Grabovetskaya, G.P.; Butkevich, L.M.

    1987-07-01T23:59:59.000Z

    The authors investigate the effect of the nucleation conditions and the initial concentration of the components on the nature of the change in the phase composition and structure along the length of the directionally crystallized bars of alloys in the Si-TaSi/sub 2/ and Si-NbSi/sub 2/ eutectic systems. The compositions of the investigated alloys are given. The starting materials were silicon of semiconductor purity, tantalum, and niobium produced by electron beam melting. The alloys were crystallized directionally by the Czochralski method. The nature of the structure and the volume ratio of the phases in the investigated alloys depend significantly on the type of seed, i.e., on the nucleation conditions of the eutectic grain. The basic phases in the eutectic alloys of the Si-TaSi/sub 2/ and Si-NbSi/sub 2/ systems are the disilicides TaSi/sub 2/ and NbSi/sub 2/ respectively.

  11. 3C-SiC Films on Si for MEMS Applications: Mechanical Properties , G. Kravchenko2

    E-Print Network [OSTI]

    Volinsky, Alex A.

    diamond tip. These results indicate that polycrystalline SiC thin films are attractive for MEMS. In addition, poly-crystalline 3C- SiC was also grown on (100)Si so that a comparison with monocrystaline 3C-SiC, also grown on (100)Si, could be made. The mechanical properties of single crystal and polycrystalline 3

  12. SiGe/Si superlattice power generators Gehong Zeng, John E. Bowers

    E-Print Network [OSTI]

    Bowers, John

    SiGe/Si superlattice power generators Gehong Zeng, John E. Bowers Department of Electrical 95064 *Corresponding Email: ali@soe.ucsc.edu, phone: (831) 459-3821 Abstract SiGe is one of the best selective emission of hot electrons through thermionic emission. SiGe/Si superlattice structures were grown

  13. Dynamics of uniform Si/SiGe uniaxial strain generation on compliant insulating substrates

    E-Print Network [OSTI]

    Dynamics of uniform Si/SiGe uniaxial strain generation on compliant insulating substrates R. L on the relaxation of Si/SiGe bilayers of different geometries to obtain up to 1.0% uniaxial tensile strain in silicon and 1.5 GPa uniaxial compressive stress in SiGe [1,2]. The process generates uniform uniaxially

  14. Thermionic power generation at high temperatures using SiGe/Si superlattices

    E-Print Network [OSTI]

    Thermionic power generation at high temperatures using SiGe/Si superlattices Daryoosh Vashaeea of SiGe/Si superlattices for power generation at high temperatures. A detailed theory based on Boltzmann provides only a modest improvement in the power factor. This is due to the fact that SiGe is a multivalley

  15. P-type SiGe/Si Superlattice Cooler Xiaofeng Fan, Gehong Zeng, Edward Croke1

    E-Print Network [OSTI]

    P-type SiGe/Si Superlattice Cooler Xiaofeng Fan, Gehong Zeng, Edward Croke1 , Gerry Robinson, Chris and characterization of single element p-type SiGe/Si superlattice coolers are described. Superlattice structures were]. SiGe is a good thermoelectric material especially for high temperature applications [11

  16. NREL: Transportation Research - Transportation News

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy: Grid IntegrationReportTransmissionResearchNewsTransportation News

  17. Large thermoelectric figure of merit in Si1-xGex nanowires Lihong Shi,1

    E-Print Network [OSTI]

    Li, Baowen

    Large thermoelectric figure of merit in Si1-xGex nanowires Lihong Shi,1 Donglai Yao,1 Gang Zhang,2 transport equation, we investigate composition effects on the thermoelectric properties of silicon thermoelectric figure of merit ZT Refs. 1­4 due to both enhancement in the power factor through increasing

  18. Commercialization potential of compositionally graded Ge - Si??x?Gex? - Si substrates for solar applications

    E-Print Network [OSTI]

    Goh, Johnathan Jian Ming

    2006-01-01T23:59:59.000Z

    This project considers the potential of Ge - Si??x?Gex? - Si substrates for solar applications. The use of compositionally graded substrates to achieve heterointegration across different materials platforms such as Si, Ge ...

  19. Acoustoelectric effects in very high-mobility p-SiGe/Ge/SiGe heterostructure

    SciTech Connect (OSTI)

    Drichko, I. L.; Diakonov, A. M.; Lebedeva, E. V.; Smirnov, I. Yu. [A. F. Ioffe Physico-Technical Institute of Russian Academy of Sciences, 194021 St. Petersburg (Russian Federation); Mironov, O. A. [Warwick SEMINANO R and D Centre, University of Warwick Science Park, Coventry CV4 7EZ (United Kingdom); Kummer, M.; Kaenel, H. von [Laboratorium fuer Festkoerperphysik ETH Zuerich, CH-8093 Zuerich (Switzerland); EpiSpeed SA, Technoparkstrasse 1, CH-8005 Zuerich (Switzerland)

    2009-11-01T23:59:59.000Z

    Measurement results of the acoustoelectric effects [surface acoustic waves (SAW) attenuation and velocity] in a high-mobility p-SiGe/Ge/SiGe structure are presented. The structure was low-energy plasma-enhanced chemical vapor deposition grown with a two-dimensional (2D) channel buried in the strained Ge layer. The measurements were performed as a function of temperature (1.5-4.2 K) and magnetic field (up to 8.4 T) at different SAW intensities at frequencies 28 and 87 MHz. Shubnikov-de Haas-like oscillations of both SAW attenuation and the velocity change have been observed. Hole density and mobility, effective mass, quantum and transport relaxation times, as well as the Dingle temperature were measured with a method free of electric contacts. The effect of heating of the 2D hole gas by the electric field of the SAW was investigated. Energy relaxation time tau{sub e}psilon and the deformation potential constant determined.

  20. Magnetotransport in low-density p-Si/SiGe heterostructures : from metal through hopping insulator to Wigner glass.

    SciTech Connect (OSTI)

    Drichko, I. L.; Dyakonov, A. M.; Smirnov, I. Yu.; Suslov, A. V.; Galperin, Y. M.; Vinokur , V.; Myronov, M.; Mironov, O. A.; Leadley, D. R.; Materials Science Division; Russian Acadademy of Science; National High Magnetic Field Lab.; Univ. of Oslo; Musashi Inst. of Tech.; Univ.of Warwick

    2008-02-01T23:59:59.000Z

    We study dc and ac transport in low-density p-Si/SiGe heterostructures at low temperatures and in a broad domain of magnetic fields up to 18 T. Complex ac conductance is determined from simultaneous measurement of velocity and attenuation of a surface acoustic wave propagating in close vicinity of the two-dimensional hole layer. The observed behavior of dc and ac conductances is interpreted as an evolution from metallic conductance at B=0 through hopping between localized states in intermediate magnetic fields (close to the plateau of the integer quantum Hall effect corresponding to the Landau-level filling factor {nu}=1) to formation of the Wigner glass in the extreme quantum limit (B {ge} 14, T {le} 0.8 K).

  1. Strain partition of SiSiGe and SiO2 SiGe on compliant substrates Center for Photonics and Optoelectronic Materials and Department of Electrical Engineering,

    E-Print Network [OSTI]

    Duffy, Thomas S.

    of crystalline Si and amorphous SiO2 deposited on crystalline SiGe on a compliant viscous borophosphorosilicate BPSG glass has been observed. Pseudomorphic epitaxial Si was deposited on SiGe films, which were fabricated on BPSG by wafer bonding and the Smart-cut® process. The strains in SiGe and Si films were found

  2. Microwave joining of SiC

    SciTech Connect (OSTI)

    Silberglitt, R.; Ahmad, I.; Tian, Y.L. [FM Technologies, Inc., Fairfax, VA (United States)] [and others

    1997-04-01T23:59:59.000Z

    The purpose of this work is to optimize the properties of SiC-SiC joints made using microwave energy. The current focus is on identification of the most effective joining methods for scale-up to large tube assemblies, including joining using SiC produced in situ from chemical precursors. During FY 1996, a new microwave applicator was designed, fabricated and tested that provides the capability for vacuum baking of the specimens and insulation and for processing under inert environment. This applicator was used to join continuous fiber-reinforced (CFCC) SiC/SiC composites using a polymer precursor to form a SiC interlayer in situ.

  3. 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

  4. 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.

  5. Low Reactivity SI Engine Lubricant Program | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment ofLetterEconomy andTerms LoanLos AngelesGuillermo10Reactivity SI

  6. ECS Transactions 3, (7), 1211-1222 (2006) Characterization of Strained Si/SiGe with Raman, Pulsed MOS Capacitor

    E-Print Network [OSTI]

    Schroder, Dieter K.

    2006-01-01T23:59:59.000Z

    ECS Transactions 3, (7), 1211-1222 (2006) 1211 Characterization of Strained Si/SiGe with Raman silicon/relaxed SiGe/graded SiGe/Si samples. The effective generation lifetime depends on the defect defective SiGe. GOI statistical analysis shows worsening oxide breakdown as the Ge concentration in the SiGe

  7. Axial Ge/Si nanowire heterostructure tunnel FETs.

    SciTech Connect (OSTI)

    Dayeh, Shadi A. (Los Alamos National Laboratory); Gin, Aaron V.; Huang, Jian Yu; Picraux, Samuel Thomas (Los Alamos National Laboratory)

    2010-03-01T23:59:59.000Z

    Axial Ge/Si heterostructure nanowires (NWs) allow energy band-edge engineering along the axis of the NW, which is the charge transport direction, and the realization of asymmetric devices for novel device architectures. This work reports on two significant advances in the area of heterostructure NWs and tunnel FETs: (i) the realization of 100% compositionally modulated Si/Ge axial heterostructure NWs with lengths suitable for device fabrication and (ii) the design and implementation of Schottky barrier tunnel FETs on these NWs for high-on currents and suppressed ambipolar behavior. Initial prototype devices with 10 nm PECVD SiN{sub x} gate dielectric resulted in a very high current drive in excess of 100 {micro}A/{micro}m (I/{pi}D) and 10{sup 5} I{sub on}/I{sub off} ratios. Prior work on the synthesis of Ge/Si axial NW heterostructures through the VLS mechanism have resulted in axial Si/Si{sub 1-x}Ge{sub x} NW heterostructures with x{sub max} {approx} 0.3, and more recently 100% composition modulation was achieved with a solid growth catalyst. In this latter case, the thickness of the heterostructure cannot exceed few atomic layers due to the slow axial growth rate and concurrent radial deposition on the NW sidewalls leading to a mixture of axial and radial deposition, which imposes a big challenge for fabricating useful devices form these NWs in the near future. Here, we report the VLS growth of 100% doping and composition modulated axial Ge/Si heterostructure NWs with lengths appropriate for device fabrication by devising a growth procedure that eliminates Au diffusion on the NW sidewalls and minimizes random kinking in the heterostructure NWs as deduced from detailed microscopy analysis. Fig. 1 a shows a cross-sectional SEM image of epitaxial Ge/Si axial NW heterostructures grown on a Ge(111) surface. The interface abruptness in these Ge/Si heterostructure NWs is of the order of the NW diameter. Some of these NWs develop a crystallographic kink that is {approx}20{sup o} off the <111> axis at about 300 nm away from the Ge/Si interface. This provides a natural marker for placing the gate contact electrodes and gate metal at appropriate location for desired high-on current and reduced ambipolarity as shown in Fig. 2. The 1D heterostructures allow band-edge engineering in the transport direction, not easily accessible in planar devices, providing an additional degree of freedom for designing tunnel FETs (TFETs). For instance, a Ge tunnel source can be used for efficient electron/hole tunneling and a Si drain can be used for reduced back-tunneling and ambipolar behavior. Interface abruptness on the other hand (particularly for doping) imposes challenges in these structures and others for realizing high performance TFETs in p-i-n junctions. Since the metal-semiconductor contacts provide a sharp interface with band-edge control, we use properly designed Schottky contacts (aided by 3D Silvaco simulations) as the tunnel barriers both at the source and drain and utilize the asymmetry in the Ge/Si channel bandgap to reduce ambipolar transport behavior generally observed in TFETs. Fig. 3 shows the room-temperature transfer curves of a Ge/Si heterostructure TFET (H-TFET) for different V{sub DS} values showing a maximum on-current of {approx}7 {micro}A, {approx}170 mV/decade inverse subthreshold slope and 5 orders of magnitude I{sub on}/I{sub off} ratios for all V{sub DS} biases considered here. This high on-current value is {approx}1750 X higher than that obtained with Si p-i-n{sup +} NW TFETs and {approx}35 X higher than that obtained with CNT TFET. The I{sub on}/I{sub off} ratio and inverse subthreshold slope compare favorably to that of Si {approx} 10{sup 3} I{sub on}/I{sub off} and {approx} 800 mV/decade SS{sup -1} but lags behind those of CNT TFET due to poor PECVD nitride gate oxide quality ({var_epsilon}{sub r} {approx} 3-4). The asymmetry in the Schottky barrier heights used here eliminates the stringent requirements of abrupt doped interfaces used in p-i-n based TFETs, which is hard to achieve both in thin-film and

  8. Transporting particulate material

    DOE Patents [OSTI]

    Aldred, Derek Leslie (North Hollywood, CA); Rader, Jeffrey A. (North Hollywood, CA); Saunders, Timothy W. (North Hollywood, CA)

    2011-08-30T23:59:59.000Z

    A material transporting system comprises a material transporting apparatus (100) including a material transporting apparatus hopper structure (200, 202), which comprises at least one rotary transporting apparatus; a stationary hub structure (900) constraining and assisting the at least one rotary transporting apparatus; an outlet duct configuration (700) configured to permit material to exit therefrom and comprising at least one diverging portion (702, 702'); an outlet abutment configuration (800) configured to direct material to the outlet duct configuration; an outlet valve assembly from the material transporting system venting the material transporting system; and a moving wall configuration in the material transporting apparatus capable of assisting the material transporting apparatus in transporting material in the material transporting system. Material can be moved from the material transporting apparatus hopper structure to the outlet duct configuration through the at least one rotary transporting apparatus, the outlet abutment configuration, and the outlet valve assembly.

  9. SiNode Systems | Department of Energy

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

    University SiNode Systems is a battery materials venture developing silicon-graphene anodes for the next generation of lithium-ion batteries. SiNode anodes offer higher...

  10. Transportation Security | ornl.gov

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

    Transportation Security SHARE Global Threat Reduction Initiative Transportation Security Cooperation Secure Transport Operations (STOP) Box Security of radioactive material while...

  11. Effect of Si substrate on interfacial SiO{sub 2} scavenging in HfO{sub 2}/SiO{sub 2}/Si stacks

    SciTech Connect (OSTI)

    Li, Xiuyan, E-mail: xiuyan@adam.t.u-tokyo.ac.jp; Yajima, Takeaki; Nishimura, Tomonori; Nagashio, Kosuke; Toriumi, Akira [Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Tokyo 113-8656 (Japan)

    2014-11-03T23:59:59.000Z

    The scavenging kinetics of an ultra-thin SiO{sub 2} interface layer (SiO{sub 2}-IL) in an HfO{sub 2}/SiO{sub 2}/Si stack is discussed by focusing on the substrate effect in addition to oxygen diffusion. {sup 18}O tracing experiments demonstrate that the O-atom moves from the SiO{sub 2}-IL to the HfO{sub 2} layer during scavenging. SiO{sub 2}-IL scavenging with various substrates (Si, SiC, and sapphire) has been found to be significantly different, which suggests that the Si in the substrate is also necessary to continuously cause the scavenging. Based on these findings and thermodynamic considerations, a kinetic model where oxygen vacancy (V{sub O}) transferred from the HfO{sub 2} reacts with the SiO{sub 2}, which is in contact with the Si-substrate, is proposed for the SiO{sub 2}-IL scavenging.

  12. Si, Yo Puedo Controlar Mi Diabetes!

    E-Print Network [OSTI]

    ¡Si, Yo Puedo Controlar Mi Diabetes! ¡Si, Yo Puedo Controlar Mí Diabetes! (Si, Yo Puedo/Latinos with diabetes. The curriculum is predicated on the American Diabetes Association's national standards of care and lifestyle skills to better control their diabetes. Relevance · Diabetes costs Texas more than 12 billion

  13. Coaxial Si/anodic titanium oxide/Si nanotube arrays for lithium-ion battery anode

    E-Print Network [OSTI]

    Zhou, Chongwu

    Nano Res 1 Coaxial Si/anodic titanium oxide/Si nanotube arrays for lithium-ion battery anode Titanium Oxide / Si Nanotube Arrays for Lithium-ion Battery Anode JiepengRong,,§Xin Fang Oxide / Si Nanotube Arrays for Lithium-ion Battery Anode Jiepeng Rong,1,§ Xin Fang,1,§ Mingyuan Ge,1

  14. MAGNETOHYDRODYNAMIC AND THERMAL ISSUES OF THE SiCf0SiC FLOW CHANNEL INSERT

    E-Print Network [OSTI]

    Abdou, Mohamed

    ) made of a silicon carbide composite (SiCf /SiC), which serves as electric and thermal insulator considered. The computa- tions were performed in a parametric form, using the electric and thermal. INTRODUCTION Flow channel inserts ~FCIs! made of a silicon car- bide composite ~SiCf 0SiC! were first proposed

  15. Fully-depleted Strained-Si on Insulator NMOSFETs without Relaxed SiGe Buffers

    E-Print Network [OSTI]

    by wafer bonding and Smart-cut processes, is utilized for the first time to make strained-Si on insulator germanium diffusion into the strained Si, formation of low-resistance silicide and altered dopant diffusion SiGe is transferred by wafer bonding and Smart- cut to a BPSG layer, and during annealing the Si

  16. "Educating transportation professionals."

    E-Print Network [OSTI]

    Acton, Scott

    "Educating transportation professionals." Michael Demetsky Henry L. Kinnier Professor mjd of Virginia Charlottesville, VA 434.924.7464 Transportation Engineering & Management Research Our group works closely with the Virginia Center for Transportation Innovation and Research (VCTIR), located

  17. Single trap dynamics in electrolyte-gated Si-nanowire field effect transistors

    SciTech Connect (OSTI)

    Pud, S.; Li, J.; Offenhäusser, A.; Vitusevich, S. A., E-mail: s.vitusevich@fz-juelich.de [Peter Grünberg Institute (PGI-8), Forschungszentrum Jülich, 52425 Jülich (Germany); Gasparyan, F. [Peter Grünberg Institute (PGI-8), Forschungszentrum Jülich, 52425 Jülich (Germany); Department of Semiconductor Physics and Microelectronics, Yerevan State University, 1 Alex Manoogian St., 0025 Yerevan (Armenia); Petrychuk, M. [Radiophysics Faculty, T. Shevchenko National University of Kyiv, 60 Volodymyrska St., 01601 Kyiv (Ukraine)

    2014-06-21T23:59:59.000Z

    Liquid-gated silicon nanowire (NW) field effect transistors (FETs) are fabricated and their transport and dynamic properties are investigated experimentally and theoretically. Random telegraph signal (RTS) fluctuations were registered in the nanolength channel FETs and used for the experimental and theoretical analysis of transport properties. The drain current and the carrier interaction processes with a single trap are analyzed using a quantum-mechanical evaluation of carrier distribution in the channel and also a classical evaluation. Both approaches are applied to treat the experimental data and to define an appropriate solution for describing the drain current behavior influenced by single trap resulting in RTS fluctuations in the Si NW FETs. It is shown that quantization and tunneling effects explain the behavior of the electron capture time on the single trap. Based on the experimental data, parameters of the single trap were determined. The trap is located at a distance of about 2?nm from the interface Si/SiO{sub 2} and has a repulsive character. The theory of dynamic processes in liquid-gated Si NW FET put forward here is in good agreement with experimental observations of transport in the structures and highlights the importance of quantization in carrier distribution for analyzing dynamic processes in the nanostructures.

  18. Sustainability and Transport

    E-Print Network [OSTI]

    Gilbert, Richard

    2006-01-01T23:59:59.000Z

    2005. Integrating Sustainability into the Trans- portationTHOUGHT PIECE Sustainability and Transport by Richardof the concept of sustainability to transport planning. In

  19. Chapter 12 Transportation

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

    2-1 November 2012 Words in bold and acronyms are defined in Chapter 32, Glossary and Acronyms. Chapter 12 Transportation This chapter describes existing transportation resources in...

  20. Transportation | Argonne National Laboratory

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

    Transportation From modeling and simulation programs to advanced electric powertrains, engines, biofuels, lubricants, and batteries, Argonne's transportation research is vital to...

  1. Transporting Hazardous Materials

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

    Transporting Hazardous Materials The procedures given below apply to all materials that are considered to be hazardous by the U.S. Department of Transportation (DOT). Consult your...

  2. Formation of nickel silicide and germanosilicide layers on Si(001), relaxed SiGe/Si(001), and strained Si/relaxed SiGe/Si(001) and effect of postthermal annealing

    SciTech Connect (OSTI)

    Ko, J.H.; Jang, C.H.; Kim, S.H.; Song, Y.-J.; Lee, N.E. [School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Kyunggi-do 440-746, Korea and Center for Advanced Plasma Surface Technology, Sungkyunkwan University, Suwon, Kyunggi-do 440-746 (Korea, Republic of); Semiconductor Division, Electronics and Telecommunications Research Institute, Taejeon 305-700 (Korea, Republic of); School of Advanced Materials Science and Engineering, Sungkyunkwan University, Suwon, Kyunggi-do 440-746, Korea and Center for Advanced Plasma Surface Technology, Sungkyunkwan University, Suwon, Kyunggi-do 440-746 (Korea, Republic of)

    2006-07-15T23:59:59.000Z

    This study compared the formation of nickel silicide or germanosilicide layers on various SiGe based heterostructures as well as the effects of the different annealing schemes (one-step versus two-step annealing) on the morphological, structural, and electrical properties. Uniform nickel silicide or germanosilicide layers were first formed by rapid thermal annealing of various heterostructures. The two-step annealing process of the samples first at 400 deg. C (T{sub A1}) and subsequently at between 600 and 800 deg. C (T{sub A2}) led to an increase in the sheet resistance, which was attributed to the formation of a high-resistivity NiSi{sub 2} phase, the agglomeration of the silicide or germanosilicide layers, and the formation of an amorphous interlayer between the silicide or germanosilicide layers. The lower sheet resistance of the silicide or germanosilicide layers formed on the relaxed-Si{sub 1-x}Ge{sub x} (x=0.15)/Si(001) substrates by two-step annealing compared with that of the samples formed on the strained Si/relaxed SiGe/Si(001) and Si(001) was attributed to the suppression of the high-resistivity NiSi{sub 2} phase as well as the superior thermal stability of the germanosilicide layer formed on the relaxed Si{sub 1-x}Ge{sub x} (x=0.15)/Si(001). The amorphous interlayers formed in the samples annealed using two-step procedure appeared to suppress interface roughening between the silicide or germanosilicide and the SiGe layer presumably due to the reduced Ni and Ge diffusion rate. Here, an amorphous interlayer was formed, which was attributed to the large negative heat of mixing in Ni-Si-Ge systems during the phase transformation and grain growth.

  3. Crystallographically tilted and partially strain relaxed GaN grown on inclined (111) facets etched on Si(100) substrate

    SciTech Connect (OSTI)

    Ansah Antwi, K. K. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Institute of Materials Research and Engineering, 3 Research Link, 117602 Singapore (Singapore); Soh, C. B. [Singapore Institute of Technology, 10 Dover Drive, Singapore 138683 (Singapore); Wee, Q. [Singapore-MIT Alliance, National University of Singapore, Singapore 117576 (Singapore); Tan, Rayson J. N.; Tan, H. R. [Institute of Materials Research and Engineering, 3 Research Link, 117602 Singapore (Singapore); Yang, P. [Singapore Synchrotron Light Source, National University of Singapore, 5 Research Link, 117603 Singapore (Singapore); Sun, L. F.; Shen, Z. X. [School of Physical and Mathematical Sciences, Nanyang Technological University, SPMS-03-01, 21 Nanyang Link (Singapore); Chua, S. J., E-mail: elecsj@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Institute of Materials Research and Engineering, 3 Research Link, 117602 Singapore (Singapore); Singapore-MIT Alliance, National University of Singapore, Singapore 117576 (Singapore)

    2013-12-28T23:59:59.000Z

    High resolution X-ray diffractometry (HR-XRD), Photoluminescence, Raman spectroscopy, and Transmission electron microscope measurements are reported for GaN deposited on a conventional Si(111) substrate and on the (111) facets etched on a Si(100) substrate. HR-XRD reciprocal space mappings showed that the GaN(0002) plane is tilted by about 0.63°?±?0.02° away from the exposed Si(111) growth surface for GaN deposited on the patterned Si(100) substrate, while no observable tilt existed between the GaN(0002) and Si(111) planes for GaN deposited on the conventional Si(111) substrate. The ratio of integrated intensities of the yellow to near band edge (NBE) luminescence (I{sub YL}/I{sub NBE}) was determined to be about one order of magnitude lower in the case of GaN deposited on the patterned Si(100) substrate compared with GaN deposited on the conventional Si(111) substrate. The Raman E{sub 2}(high) optical phonon mode at 565.224?±?0.001?cm{sup ?1} with a narrow full width at half maximum of 1.526?±?0.002?cm{sup ?1} was measured, for GaN deposited on the patterned Si(100) indicating high material quality. GaN deposition within the trench etched on the Si(100) substrate occurred via diffusion and mass-transport limited mechanism. This resulted in a differential GaN layer thickness from the top (i.e., 1.8??m) of the trench to the bottom (i.e., 0.3??m) of the trench. Mixed-type dislocation constituted about 80% of the total dislocations in the GaN grown on the inclined Si(111) surface etched on Si(100)

  4. 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

  5. Stability of SiC-Matrix Microencapsulated Fuel Constituents at Relevant LWR Conditions

    SciTech Connect (OSTI)

    Terrani, Kurt A [ORNL] [ORNL; Katoh, Yutai [ORNL] [ORNL; Leonard, Keith J [ORNL] [ORNL; Perez-Bergquist, Alex G [ORNL] [ORNL; Silva, Chinthaka M [ORNL] [ORNL; Snead, Lance Lewis [ORNL] [ORNL

    2014-01-01T23:59:59.000Z

    This paper addresses certain key feasibility issues facing the application of SiC-matrix microencapsulated fuels for light water reactor application. Issues addressed are the irradiation stability of the SiC-based nano-powder ceramic matrix under LWR-relevant irradiation conditions, the presence or extent of reaction of the SiC matrix with zirconium-based cladding, the stability of the inner and outer pyrolytic graphite layers of the microencapsulated (TRISO) particle at this uncharacteristically low irradiation temperature, and the state of the particle-matrix interface following irradiation which could possibly effect thermal transport. In the process of determining these feasibility issues microstructural evolution and change in dimension and thermal conductivity was studied. As a general finding the SiC matrix was found to be quite stable with behavior similar to that of CVD SiC. In magnitude the irradiation-induced swelling of the matrix material was slightly higher and irradiation-degraded thermal conductivity was slightly lower as compared to CVD SiC. No significant reaction of this SiC-based nano-powder ceramic matrix material with Zircaloy was observed. Irradiation of the TRISO in the 320-360 C range to a maximum dose of 7.7 1025 n/m2 (E > 0.1 MeV) did not have significant negative impact on the constituent layers of the TRISO fuel. At the highest dose studied layer structure and interface integrity remained essentially unchanged with good apparent thermal transport through the microsphere to the surrounding matrix.

  6. Oxygen Transport Ceramic Membranes

    SciTech Connect (OSTI)

    S. Bandopadhyay; N. Nagabhushana

    2003-08-07T23:59:59.000Z

    In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/ Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Existing facilities were modified for evaluation of environmental assisted slow crack growth and creep in flexural mode. Processing of perovskites of LSC, LSF and LSCF composition were continued for evaluation of mechanical properties as a function of environment. These studies in parallel to those on the LSFCO composition is expect to yield important information on questions such as the role of cation segregation and the stability of the perovskite structure on crack initiation vs. crack growth. Studies have been continued on the La{sub 1-x}Sr{sub x}FeO{sub 3-d} composition using neutron diffraction and TGA studies. A transition from p-type to n-type of conductor was observed at relative low pO{sub 2}, at which the majority carriers changed from the holes to electrons because of the valence state decreases in Fe due to the further loss of oxygen. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport. Data obtained at 850 C show that the stoichiometry in La{sub 0.2}Sr{sub 0.8}Fe{sub 0.8}Cr{sub 0.2}O{sub 3-x} vary from {approx}2.85 to 2.6 over the pressure range studied. From the stoichiometry a lower limit of 2.6 corresponding to the reduction of all Fe{sup 4+} to Fe{sup 3+} and no reduction of Cr{sup 3+} is expected.

  7. Similarity of Stranski-Krastanow growth of Ge/Si and SiGe/Si (001)

    SciTech Connect (OSTI)

    Norris, D. J.; Qiu, Y.; Walther, T. [Department of Electronic and Electrical Engineering, University of Sheffield, Mappin Building, Mappin Street, Sheffield S1 3JD (United Kingdom); Dobbie, A.; Myronov, M. [Department of Physics, University of Warwick, Coventry CV4 7A (United Kingdom)

    2014-01-07T23:59:59.000Z

    This study investigates the onset of islanding (Stranski-Krastanow transition) in strained pure germanium (Ge) and dilute silicon-germanium (SiGe) alloy layers grown by chemical vapour deposition on Si(001) substrates. Integration of compositional profiles is compared to a novel method for quantification of X-ray maps acquired in cross-sectional scanning transmission electron microscopy, together with simulations of surface segregation of Ge. We show that Si{sub 1?x}Ge{sub x} alloys for germanium concentrations x???0.27 grow two-dimensionally and stay flat up to considerable layer thicknesses, while layers with concentrations in the range 0.28?

  8. Effect of nanodot areal density and period on thermal conductivity in SiGe/Si nanodot superlattices

    E-Print Network [OSTI]

    Haller, Gary L.

    Effect of nanodot areal density and period on thermal conductivity in SiGe/Si nanodot superlattices-plane thermal conductivity in SiGe/Si nanodot superlattices NDSLs . For all ND areal densities considered, we found that in SiGe/Si NDSLs decreased monotonically with decreasing period and reached values lower than

  9. On the design of a 55 GHz Si/SiGe HBT frequency doubler operating close to f max

    E-Print Network [OSTI]

    On the design of a 55 GHz Si/SiGe HBT frequency doubler operating close to f max S. Bruce, M. Kim. Abstract In this paper we present for the first time experimental results on a frequency doubler using a Si/SiGe GHz, for the Si/SiGe HBT, the conversion efficiency in a not completely optimised circuit was found

  10. Ultrathin Strained Si-on-Insulator and SiGe-on-Insulator Created using Low Temperature Wafer Bonding

    E-Print Network [OSTI]

    Ultrathin Strained Si-on-Insulator and SiGe-on-Insulator Created using Low Temperature Wafer, uniform thickness, low defect density, monocrystalline SiGe alloys and strained Si on any desired substrate was developed, allowing for the creation of SiGe-on-insulator and strained Si-on-insulator. After

  11. Propagation of misfit dislocations from buffer/Si interface into Si

    DOE Patents [OSTI]

    Liliental-Weber, Zuzanna (El Sobrante, CA); Maltez, Rogerio Luis (Porto Alegre, BR); Morkoc, Hadis (Richmond, VA); Xie, Jinqiao (Raleigh, VA)

    2011-08-30T23:59:59.000Z

    Misfit dislocations are redirected from the buffer/Si interface and propagated to the Si substrate due to the formation of bubbles in the substrate. The buffer layer growth process is generally a thermal process that also accomplishes annealing of the Si substrate so that bubbles of the implanted ion species are formed in the Si at an appropriate distance from the buffer/Si interface so that the bubbles will not migrate to the Si surface during annealing, but are close enough to the interface so that a strain field around the bubbles will be sensed by dislocations at the buffer/Si interface and dislocations are attracted by the strain field caused by the bubbles and move into the Si substrate instead of into the buffer epi-layer. Fabrication of improved integrated devices based on GaN and Si, such as continuous wave (CW) lasers and light emitting diodes, at reduced cost is thereby enabled.

  12. Photoluminescence line width of self-assembled Ge(Si) islands arranged between strained Si layers

    SciTech Connect (OSTI)

    Shaleev, M. V., E-mail: shaleev@ipm.sci-nnov.ru; Novikov, A. V.; Baydakova, N. A.; Yablonskiy, A. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Kuznetsov, O. A. [Nizhny Novgorod State University, Physico-Technical Research Institute (Russian Federation); Lobanov, D. N.; Krasilnik, Z. F. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2011-02-15T23:59:59.000Z

    The effect of variations in the strained Si layer thicknesses, measurement temperature, and optical excitation power on the width of the photoluminescence line produced by self-assembled Ge(Si) nanoislands, which are grown on relaxed SiGe/Si(001) buffer layers and arranged between strained Si layers, is studied. It is shown that the width of the photoluminescence line related to the Ge(Si) islands can be decreased or increased by varying the thickness of strained Si layers lying above and under the islands. A decrease in the width of the photoluminescence line of the Ge(Si) islands to widths comparable with the width of the photoluminescence line of quantum dot (QD) structures based on direct-gap InAs/GaAs semiconductors is attained with consideration of diffusive smearing of the strained Si layer lying above the islands.

  13. High-quality strain-relaxed SiGe films grown with low temperature Si buffer

    SciTech Connect (OSTI)

    Luo, Y. H.; Wan, J.; Forrest, R. L.; Liu, J. L.; Goorsky, M. S.; Wang, K. L.

    2001-06-15T23:59:59.000Z

    High-quality strain-relaxed SiGe templates with a low threading dislocation density and smooth surface are critical for device performance. In this work, SiGe films on low temperature Si buffer layers were grown by solid-source molecular beam epitaxy and characterized by atomic force microscope, double-axis x-ray diffraction, photoluminescence spectroscopy, and Raman spectroscopy. Effects of the growth temperature and the thickness of the low temperature Si buffer were studied. It was demonstrated that when using proper growth conditions for the low temperature Si buffer the Si buffer became tensily strained and gave rise to the compliant effect. The lattice mismatch between the SiGe and the Si buffer layer was reduced. A 500 nm Si{sub 0.7}Ge{sub 0.3} film with a low threading dislocation density as well as smooth surface was obtained by this method. {copyright} 2001 American Institute of Physics.

  14. Multi-modal Transportation > Highway Transportation > Trucking > Railroad transportation > Public transit > Rural transportation > Rural transit > Freight pipeline transportation > Airport planning and development > Airport maintenance > Bicycle and pedes

    E-Print Network [OSTI]

    Multi-modal Transportation > Highway Transportation > Trucking > Railroad transportation > Public transit > Rural transportation > Rural transit > Freight pipeline transportation > Airport planning and development > Airport maintenance > Bicycle and pedestrian > Ports and waterways >>> Transportation operat

  15. Multi-modal Transportation > Highway Transportation > Trucking > Railroad transportation > Public transit > Rural transportation > Rural transit > Freig pipeline transportation > Airport planning and development > Airport maintenance > Bicycle and pedestr

    E-Print Network [OSTI]

    Multi-modal Transportation > Highway Transportation > Trucking > Railroad transportation > Public transit > Rural transportation > Rural transit > Freig pipeline transportation > Airport planning and development > Airport maintenance > Bicycle and pedestrian > Ports and waterways >>> Transportation ope

  16. Graduate Certificate in Transportation

    E-Print Network [OSTI]

    Bertini, Robert L.

    Graduate Certificate in Transportation Nohad A. Toulan School of Urban Studies and Planning of Engineering and Computer Science integrated transportation systems. The Graduate Certificate in Transportation their capabilities. Students in the program can choose among a wide range of relevant courses in transportation

  17. TRANSPORTATION Annual Report

    E-Print Network [OSTI]

    Minnesota, University of

    2003 CENTER FOR TRANSPORTATION STUDIES Annual Report #12;Center for Transportation Studies University of Minnesota 200 Transportation and Safety Building 511 Washington Avenue S.E. Minneapolis, MN publication is a report of transportation research, education, and outreach activities for the period July

  18. Minnesota's Transportation Economic Development (TED)

    E-Print Network [OSTI]

    Minnesota, University of

    Minnesota's Transportation Economic Development (TED) Pilot Program Center for Transportation Studies Transportation Research Conference May 24-25, 2011 #12;Transportation Role in Economic Development · Carefully targeted transportation infrastructure improvements will: ­ Stimulate new economic development

  19. Introduction Transport in disordered graphene

    E-Print Network [OSTI]

    Fominov, Yakov

    Introduction Transport in disordered graphene Summary Ballistic transport in disordered graphene P, Gornyi, Mirlin Ballistic transport in disordered graphene #12;Introduction Transport in disordered graphene Summary Outline 1 Introduction Model Experimental motivation Transport in clean graphene 2

  20. Excitation wavelength dependent photoluminescence in structurally non-uniform Si/SiGe-island heteroepitxial multilayers

    SciTech Connect (OSTI)

    Modi, N.; Tsybeskov, L. [Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States); Lockwood, D. J.; Wu, X.; Baribeau, J.-M. [Institute for Microstructural Sciences, National Research Council, Ottawa, Ontario K1A 0R6 (Canada)

    2012-06-01T23:59:59.000Z

    In nanometer-size Si/SiGe-island heteroepitxial multilayers grown on Si(001), low temperature photoluminescence spectra are observed that strongly depend on the excitation wavelength and show a strong correlation with structural properties revealed by transmission electron microscopy. These experimental results can be explained by assuming that the optically created carriers are strongly localized at Si/SiGe island heterointerfaces. We show that electron-hole pairs are generated and recombine within spatial regions mainly defined by the photoexcitation penetration depth, and that the estimated exciton diffusion length is notably short and comparable with the SiGe-island average size.

  1. Magnetron-sputter epitaxy of {beta}-FeSi{sub 2}(220)/Si(111) and {beta}-FeSi{sub 2}(431)/Si(001) thin films at elevated temperatures

    SciTech Connect (OSTI)

    Liu Hongfei; Tan Chengcheh; Chi Dongzhi [Institute of Materials Research and Engineering (IMRE), A-STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602 (Singapore)

    2012-07-15T23:59:59.000Z

    {beta}-FeSi{sub 2} thin films have been grown on Si(111) and Si(001) substrates by magnetron-sputter epitaxy at 700 Degree-Sign C. On Si(111), the growth is consistent with the commonly observed orientation of [001]{beta}-FeSi{sub 2}(220)//[1-10]Si(111) having three variants, in-plane rotated 120 Degree-Sign with respect to one another. However, on Si(001), under the same growth conditions, the growth is dominated by [-111]{beta}-FeSi{sub 2}(431)//[110]Si(001) with four variants, which is hitherto unknown for growing {beta}-FeSi{sub 2}. Photoelectron spectra reveal negligible differences in the valance-band and Fe2p core-level between {beta}-FeSi{sub 2} grown on Si(111) and Si(001) but an apparent increased Si-oxidization on the surface of {beta}-FeSi{sub 2}/Si(001). This phenomenon is discussed and attributed to the Si-surface termination effect, which also suggests that the Si/Fe ratio on the surface of {beta}-FeSi{sub 2}(431)/Si(001) is larger than that on the surface of {beta}-FeSi{sub 2}(220)/Si(111).

  2. SiD Letter of Intent

    SciTech Connect (OSTI)

    Aihara, H., (Ed.); Burrows, P., (Ed.); Oreglia, M., (Ed.); Berger, E.L.; Guarino, V.; Repond, J.; Weerts, H.; Xia, L.; Zhang, J.; /Argonne, HEP; Zhang, Q.; /Argonne, HEP /Beijing, Inst. High Energy Phys.; Srivastava, A.; /Birla Inst. Tech. Sci.; Butler, J.M.; /Boston U.; Goldstein, Joel; Velthuis, J.; /Bristol U.; Radeka, V.; /Brookhaven; Zhu, R.-Y.; /Caltech.; Lutz, P.; /DAPNIA, Saclay; de Roeck, A.; Elsener, K.; Gaddi, A.; Gerwig, H.; /CERN /Cornell U., LNS /Ewha Women's U., Seoul /Fermilab /Gent U. /Darmstadt, GSI /Imperial Coll., London /Barcelona, Inst. Microelectron. /KLTE-ATOMKI /Valencia U., IFIC /Cantabria Inst. of Phys. /Louis Pasteur U., Strasbourg I /Durham U., IPPP /Kansas State U. /Kyungpook Natl. U. /Annecy, LAPP /LLNL, Livermore /Louisiana Tech. U. /Paris U., VI-VII /Paris U., VI-VII /Munich, Max Planck Inst. /MIT, LNS /Chicago, CBC /Moscow State U. /Nanjing U. /Northern Illinois U. /Obninsk State Nucl. Eng. U. /Paris U., VI-VII /Strasbourg, IPHC /Prague, Inst. Phys. /Princeton U. /Purdue U. /Rutherford /SLAC /SUNY, Stony Brook /Barcelona U. /Bonn U. /UC, Davis /UC, Santa Cruz /Chicago U. /Colorado U. /Delhi U. /Hawaii U. /Helsinki U. /Indiana U. /Iowa U. /Massachusetts U., Amherst /Melbourne U. /Michigan U. /Minnesota U. /Mississippi U. /Montenegro U. /New Mexico U. /Notre Dame U. /Oregon U. /Oxford U. /Ramon Llull U., Barcelona /Rochester U. /Santiago de Compostela U., IGFAE /Hefei, CUST /Texas U., Arlington /Texas U., Dallas /Tokyo U. /Washington U., Seattle /Wisconsin U., Madison /Wayne State U. /Yale U. /Yonsei U.

    2012-04-11T23:59:59.000Z

    This document presents the current status of the Silicon Detector (SiD) effort to develop an optimized design for an experiment at the International Linear Collider. It presents detailed discussions of each of SiD's various subsystems, an overview of the full GEANT4 description of SiD, the status of newly developed tracking and calorimeter reconstruction algorithms, studies of subsystem performance based on these tools, results of physics benchmarking analyses, an estimate of the cost of the detector, and an assessment of the detector R and D needed to provide the technical basis for an optimised SiD.

  3. Identification of dominant scattering mechanism in epitaxial graphene on SiC

    SciTech Connect (OSTI)

    Lin, Jingjing; Guo, Liwei, E-mail: lwguo@iphy.ac.cn, E-mail: chenx29@aphy.iphy.ac.cn; Jia, Yuping; Huang, Jiao; Guo, Yu; Li, Zhilin; Chen, Xiaolong, E-mail: lwguo@iphy.ac.cn, E-mail: chenx29@aphy.iphy.ac.cn [Research and Development Center for Functional Crystals, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China); Yang, Rong; Wu, Shuang; Zhang, Guangyu [Nanoscale Physics and Devices Laboratory, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, P.O. Box 603, Beijing 100190 (China)

    2014-05-05T23:59:59.000Z

    A scheme of identification of scattering mechanisms in epitaxial graphene (EG) on SiC substrate is developed and applied to three EG samples grown on SiC (0001), (112{sup ¯}0), and (101{sup ¯}0) substrates. Hall measurements combined with defect detection technique enable us to evaluate the individual contributions to the carrier scatterings by defects and by substrates. It is found that the dominant scatterings can be due to either substrate or defects, dependent on the substrate orientations. The EG on SiC (112{sup ¯}0) exhibits a better control over the two major scattering mechanisms and achieves the highest mobility even with a high carrier concentration, promising for high performance graphene-based electronic devices. The method developed here will shed light on major aspects in governing carrier transport in EG to harness it effectively.

  4. Amorphization of nanocrystalline 3C-SiC irradiated with Si+ ions...

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

    interface and interior amorphization. Citation: Jiang W, H Wang, I Kim, Y Zhang, and WJ Weber.2010."Amorphization of nanocrystalline 3C-SiC irradiated with Si+ ions."Journal of...

  5. Stopping power measurements of He ions in Si and SiC by time...

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

    power measurements of He ions in Si and SiC by time-of-flight spectrometry. Abstract: Electronic energy loss is the fundamental mechanism accountable for the response of...

  6. Strained-Si/SiGe enhancement mode structures for quantum computing.

    SciTech Connect (OSTI)

    Savage, Donald (University of Wisconsin-Madison); Bishop, Nathaniel; Lilly, Michael Patrick; Carroll, Malcolm S.; Ten Eyck, Gregory A.

    2010-03-01T23:59:59.000Z

    Silicon is an ideal system for investigating single electron or isolated donor spins for quantum computation, due to long spin coherence times. Enhancement mode strained-silicon/silicon germanium (sSi/SiGe) devices would offer an as-yet untried path toward electron or electron/donor quantum dot systems. Thin, undoped SiGe dielectrics allow tight electrostatic confinement, as well as potential Lande g-factor engineered spin manipulation. In this talk we summarize recent progress toward sSi/SiGe enhancement mode devices on sSi on insulator, including characterization with X-ray diffraction and atomic force microscopy, as well as challenges faced and progress on integration of either top-down and bottom-up donor placement approaches in a sSi/SiGe enhancement mode structure.

  7. Limited-area growth of Ge and SiGe on Si

    E-Print Network [OSTI]

    Kim, Meekyung, Ph. D. Massachusetts Institute of Technology

    2011-01-01T23:59:59.000Z

    The goal of this thesis is to develop and understand processing conditions that improve the surface morphology and reduce the dislocation density in limited-area heteroepitaxy of Ge and SiGe on Si (100) substrates. Low ...

  8. Investigation of lateral gated quantum devices in Si/SiGe heterostructures

    E-Print Network [OSTI]

    Lai, Andrew P. (Andrew Pan)

    2013-01-01T23:59:59.000Z

    Quantum dots in Si/SiGe have long spin decoherence times, due to the low density of nuclear spins and weak coupling between nuclear and electronic spins. Because of this, they are excellent candidates for use as solid state ...

  9. MOSFET Channel Engineering using Strained Si, SiGe, and Ge Channels

    E-Print Network [OSTI]

    Fitzgerald, Eugene A.

    Biaxial tensile strained Si grown on SiGe virtual substrates will be incorporated into future generations of CMOS technology due to the lack of performance increase with scaling. Compressively strained Ge-rich alloys with ...

  10. The effect of surface conductance on lateral gated quantum devices in Si/SiGe heterostructures

    E-Print Network [OSTI]

    Lin, Xi

    Quantum dots in Si/SiGe heterostructures are expected to have relatively long electron spin decoherence times, because of the low density of nuclear spins and the weak coupling between nuclear and electron spins. We provide ...

  11. Point contact Andreev spectroscopy of epitaxial Co{sub 2}FeSi Heusler alloys on GaAs (001)

    SciTech Connect (OSTI)

    Lehmann, Hauke; Merkt, Ulrich; Meier, Guido [Institut fuer Angewandte Physik und Zentrum fuer Mikrostrukturforschung, Universitaet Hamburg, Jungiusstrasse 11, 20355 Hamburg (Germany); Scholtyssek, Jan M. [Institut fuer Angewandte Physik und Zentrum fuer Mikrostrukturforschung, Universitaet Hamburg, Jungiusstrasse 11, 20355 Hamburg (Germany); Institut fuer Elektrische Messtechnik und Grundlagen der Elektrotechnik, Technische Universitaet Braunschweig, Hans-Sommer-Strasse 66, 38106 Braunschweig (Germany); Herrmann, Claudia; Herfort, Jens [Paul-Drude-Institut fuer Festkoerperelektronik, Hausvogteiplatz 5-7, 10117 Berlin (Germany)

    2011-09-15T23:59:59.000Z

    The predicted half-metallicity of Co{sub 2}FeSi in combination with its high Curie temperature of above 980 K makes this Heusler alloy interesting for spinelectronics. Thin Co{sub 2}FeSi films are grown by molecular-beam epitaxy on GaAs (001) with a close lattice match. We present a study of point-contact measurements on different films, varying in thickness between 18 nm and 48 nm and in substrate temperature during deposition between 100 deg. C and 300 deg. C. Transport spin polarizations at the Fermi level are determined from differential conductance curves obtained by point-contact Andreev-reflection spectroscopy. A maximum transport spin polarization of about 60% is measured for a 18 nm thin Co{sub 2}FeSi film grown at 200 deg. C.

  12. Effect of irradiation on thermal expansion of SiC{sub f}/SiC composites

    SciTech Connect (OSTI)

    Senor, D.J. [Pacific Northwest Lab., Richland, WA (United States); Trimble, D.J. [Westinghouse Hanford Co., Richland, WA (United States); Woods, J.J. [Lockheed Martin, Schenectady, NY (United States)

    1996-06-01T23:59:59.000Z

    Linear thermal expansion was measured on five different SiC-fiber-reinforced/SiC-matrix (SiC{sub f}/SiC) composite types in the unirradiated and irradiated conditions. Two matrices were studied in combination with Nicalon CG reinforcement and a 150 nm PyC fiber/matrix interface: chemical vapor infiltrated (CVI) SiC and liquid-phase polymer impregnated precursor (PIP) SiC. Composites of PIP SiC with Tyranno and HPZ fiber reinforcement and a 150 nm PyC interface were also tested, as were PIP SiC composites with Nicalon CG reinforcement and a 150 nm BN fiber/matrix interface. The irradiation was conducted in the Experimental Breeder Reactor-II at a nominal temperature of 1,000 C to doses of either 33 or 43 dpa-SiC. Irradiation caused complete fiber/matrix debonding in the CVI SiC composites due to a dimensional stability mismatch between fiber and matrix, while the PIP SiC composites partially retained their fiber/matrix interface after irradiation. However, the thermal expansion of all the materials tested was found to be primarily dependent on the matrix and independent of either the fiber or the fiber/matrix interface. Further, irradiation had no significant effect on thermal expansion for either the CVI SiC or PIP SiC composites. In general, the thermal expansion of the CVI SiC composites exceeded that of the PIP SiC composites, particularly at elevated temperatures, but the expansion of both matrix types was less than chemical vapor deposited (CVD) {beta}-SiC at all temperatures.

  13. Cubic GaN on Nanopatterned 3C-SiC/Si (001) Substrates

    E-Print Network [OSTI]

    As, Donat Josef

    Chapter 15 Cubic GaN on Nanopatterned 3C-SiC/Si (001) Substrates Ricarda Maria Kemper, Donat Josef relaxed cubic GaN by plasma-assisted molecular beam epitaxy on prepat- terned 3C-SiC/Si (001) substrates) process. We analyze the influence of the substrate on the GaN growth and show that it is possible to grow

  14. Raman scattering in Si/SiGe nanostructures: Revealing chemical composition, strain, intermixing, and heat dissipation

    SciTech Connect (OSTI)

    Mala, S. A.; Tsybeskov, L., E-mail: tsybesko@njit.edu [Department of Electrical and Computer Engineering, New Jersey Institute of Technology, Newark, New Jersey 07102 (United States); Lockwood, D. J.; Wu, X.; Baribeau, J.-M. [National Research Council, Ottawa, Ontario K1A 0R6 (Canada)

    2014-07-07T23:59:59.000Z

    We present a quantitative analysis of Raman scattering in various Si/Si{sub 1-x}Ge{sub x} multilayered nanostructures with well-defined Ge composition (x) and layer thicknesses. Using Raman and transmission electron microscopy data, we discuss and model Si/SiGe intermixing and strain. By analyzing Stokes and anti-Stokes Raman signals, we calculate temperature and discuss heat dissipation in the samples under intense laser illumination.

  15. Secure Transportation Management

    SciTech Connect (OSTI)

    Gibbs, P. W. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2014-10-15T23:59:59.000Z

    Secure Transport Management Course (STMC) course provides managers with information related to procedures and equipment used to successfully transport special nuclear material. This workshop outlines these procedures and reinforces the information presented with the aid of numerous practical examples. The course focuses on understanding the regulatory framework for secure transportation of special nuclear materials, identifying the insider and outsider threat(s) to secure transportation, organization of a secure transportation unit, management and supervision of secure transportation units, equipment and facilities required, training and qualification needed.

  16. Water Transport Within the STack: Water Transport Exploratory...

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

    Within the STack: Water Transport Exploratory Studies Water Transport Within the STack: Water Transport Exploratory Studies Part of a 100 million fuel cell award announced by DOE...

  17. Room-temperature 1.3 pm electroluminescence from strained Si, -,Ge,/Si quantum wells

    E-Print Network [OSTI]

    Room-temperature 1.3 pm electroluminescence from strained Si, -,Ge,/Si quantum wells Q. Mi, X. Xiao report the first room-temperature 1.3 ,um electroluminescence from strained Sir-,Ge,/Si quantum wells to that from the Sit-,GeX wells. A minimum band offset is required to have effective room

  18. Selective-area room temperature visible photoluminescence from SiC/Si heterostructures

    E-Print Network [OSTI]

    Steckl, Andrew J.

    shown8 to produce monocrystalline thin films, while minimizing the high temperature exposure. The Sic mismatch, heteroepitaxial growth of Sic films on Si has been achieved by several groups?-' In addition, SicSi. For example, polycrystalline Sic deposited on Si after it is rendered porous has been utilized9

  19. SUPPORTING INFORMATION Si Microwire Solar Cells: Improved Efficiency with a

    E-Print Network [OSTI]

    S1 SUPPORTING INFORMATION Si Microwire Solar Cells: Improved Efficiency with a Conformal SiO2 Layer Technologies, 174 Haverhill Road, Topsfield, MA 01983 School of Engineering and Applied Sciences, Harvard improvements (%) of Si microwire solar cells (6 µµµµm height) after conformal SiO2 coating SiO2 thickness Jsc

  20. SiGe-On-Insulator (SGOI) Technology and MOSFET Fabrication

    E-Print Network [OSTI]

    SiGe-On-Insulator (SGOI) Technology and MOSFET Fabrication Zhiyuan Cheng, E. A. Fitzgerald, and D with less defects in SiGe film, but the SiGe film uniformity is inferior. "Smart-cut" approach has better control on the SiGe film thickness and uniformity, and is applicable to wider Ge content range of the SiGe

  1. Transportation Infrastructure and Sustainable Development

    E-Print Network [OSTI]

    Boarnet, Marlon G.

    2008-01-01T23:59:59.000Z

    A Better Forecasting Tool for Transportation Decision-making,” Mineta Transportation Institute, San Jose Stateat the 2008 meeting of the Transportation Research Board and

  2. Transportation Analysis | Clean Energy | ORNL

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

    Transportation Analysis SHARE Transportation Analysis Transportation Analysis efforts at Oak Ridge National Laboratory contribute to the efficient, safe, and free movement of...

  3. Transportation Investment and

    E-Print Network [OSTI]

    Levinson, David M.

    Transportation Investment and Economic Development: Has the TIED turned? David Levinson University Transportation Investments was Historically Concomitant with Land and Economic Development #12;Canals Railways Surfaced Roads Crude Oil Pipelines Gas Pipelines Telegraph 1825 1985 Proportion of Maximum Extent Growth

  4. Transportation Management Research Collection /

    E-Print Network [OSTI]

    Handy, Todd C.

    , Peterbilt Motors, and General Electric. He was a national panel member of the American Arbitration, Noise and Environmental Pollution, Transportation Co-ordination and Consolidation, Transportation -- Docket 8613 1957 Civil Aeronautics Board ­ General passenger fare investigation -- Docket 8008 et al

  5. Packaging and Transportation Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1995-09-27T23:59:59.000Z

    Establishes safety requirements for the proper packaging and transportation of offsite shipments and onsite transfers of hazardous materials andor modal transport. Cancels DOE 1540.2 and DOE 5480.3

  6. Packaging and Transportation Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1995-09-27T23:59:59.000Z

    Establishes safety requirements for the proper packaging and transportation of Department of Energy (DOE) offsite shipments and onsite transfers of hazardous materials and for modal transport. Canceled by DOE 460.1A

  7. Packaging and Transportation Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    1996-10-02T23:59:59.000Z

    Establishes safety requirements for the proper packaging and transportation of Department of Energy (DOE) offsite shipments and onsite transfers of hazardous materials and for modal transport. Cancels DOE O 460.1.

  8. Biofuels and Transportation

    E-Print Network [OSTI]

    Minnesota, University of

    Biofuels and Transportation Impacts and Uncertainties Some Observations of a Reformed Ethanol and Logistics Symposium 3 Topics · Why Biofuels · Ethanol Economics · Ethanol Transportation Equipment Biofuels? · National Security · Reduce Imports of oil · Peak Oil · Replace Fossil Resources

  9. Linear Motor Powered Transportation

    E-Print Network [OSTI]

    Thornton, Richard D.

    This special issue on linear-motor powered transportation covers both supporting technologies and innovative transport systems in various parts of the World, as this technology moves from the lab to commercial operations. ...

  10. Transportation Management Workshop: Proceedings

    SciTech Connect (OSTI)

    Not Available

    1993-10-01T23:59:59.000Z

    This report is a compilation of discussions presented at the Transportation Management Workshop held in Gaithersburg, Maryland. Topics include waste packaging, personnel training, robotics, transportation routing, certification, containers, and waste classification.

  11. 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

  12. Indianapolis Public Transportation Corporation

    SciTech Connect (OSTI)

    Not Available

    2004-12-01T23:59:59.000Z

    Fact sheet describes the National Renewable Energy Laboratory's evaluation of Indianapolis Public Transportation Corporation's (IndyGo's) hybrid electric buses.

  13. Lubbock Metropolitan Transportation Plan

    E-Print Network [OSTI]

    Lubbock Metropolitan Planning Organization

    2007-09-18T23:59:59.000Z

    for Users (SAFETEA-LU) and its predecessors, the Transportation Equity Act for the 21st Century (TEA-21) and the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991, specified the transportation systems on which certain federal funds can... in Chapter 5 ? Streets and Highways; Chapter 6 ? Public Transportation; Chapter 7 ? Bicycle and Pedestrian Plan; Chapter 8 ? Lubbock International Airport and Chapter 9 ? Railroads and Trucking. Federally funded transit projects were developed...

  14. Transportation and its Infrastructure

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    subsidies on fossil transport fuels, subsidies on commutingC. , 2003: Subsidies that encourage fossil fuel use in

  15. Monolayer-induced band shifts at Si(100) and Si(111) surfaces

    SciTech Connect (OSTI)

    Mäkinen, A. J., E-mail: Antti.Makinen@nrl.navy.mil; Kim, Chul-Soo; Kushto, G. P. [Naval Research Laboratory, 4555 Overlook Avenue, Washington, DC 20375 (United States)

    2014-01-27T23:59:59.000Z

    We report our study of the interfacial electronic structure of Si(100) and Si(111) surfaces that have been chemically modified with various organic monolayers, including octadecene and two para-substituted benzene derivatives. X-ray photoelectron spectroscopy reveals an upward band shift, associated with the assembly of these organic monolayers on the Si substrates, that does not correlate with either the dipole moment or the electron withdrawing/donating character of the molecular moieties. This suggests that the nature and quality of the self-assembled monolayer and the intrinsic electronic structure of the semiconductor material define the interfacial electronic structure of the functionalized Si(100) and Si(111) surfaces.

  16. Si and SiGe based double top gated accumulation mode single electron transistors for quantum bits.

    SciTech Connect (OSTI)

    Wendt, Joel Robert; Ten Eyck, Gregory A.; Childs, Kenton David; Celler, G. (SOITEC); Eng, Kevin; Eriksson, Mark A. (University of Wisconsin); Kluskiewicz, Dan (University of New Mexico); Stevens, Jeffrey; Carroll, Malcolm S.; Nordberg, Eric; Lilly, Michael Patrick; Lemp, Thomas; Sheng, Josephine Juin-Jye

    2008-10-01T23:59:59.000Z

    There is significant interest in forming quantum bits (qubits) out of single electron devices for quantum information processing (QIP). Information can be encoded using properties like charge or spin. Spin is appealing because it is less strongly coupled to the solid-state environment so it is believed that the quantum state can better be preserved over longer times (i.e., that is longer decoherence times may be achieved). Long spin decoherence times would allow more complex qubit operations to be completed with higher accuracy. Recently spin qubits were demonstrated by several groups using electrostatically gated modulation doped GaAs double quantum dots (DQD) [1], which represented a significant breakthrough in the solid-state field. Although no Si spin qubit has been demonstrated to date, work on Si and SiGe based spin qubits is motivated by the observation that spin decoherence times can be significantly longer than in GaAs. Spin decoherence times in GaAs are in part limited by the random spectral diffusion of the non-zero nuclear spins of the Ga and As that couple to the electron spin through the hyperfine interaction. This effect can be greatly suppressed by using a semiconductor matrix with a near zero nuclear spin background. Near zero nuclear spin backgrounds can be engineered using Si by growing {sup 28}Si enriched epitaxy. In this talk, we will present fabrication details and electrical transport results of an accumulation mode double top gated Si metal insulator semiconductor (MIS) nanostructure, Fig 1 (a) & (b). We will describe how this single electron device structure represent a path towards forming a Si based spin qubit similar in design as that demonstrated in GaAs. Potential advantages of this novel qubit structure relative to previous approaches include the combination of: no doping (i.e., not modulation doped); variable two-dimensional electron gas (2DEG) density; CMOS compatible processes; and relatively small vertical length scales to achieve smaller dots. A primary concern in this structure is defects at the insulator-silicon interface. The Sandia National Laboratories 0.35 {micro}m fab line was used for critical processing steps including formation of the gate oxide to examine the utility of a standard CMOS quality oxide silicon interface for the purpose of fabricating Si qubits. Large area metal oxide silicon (MOS) structures showed a peak mobility of 15,000 cm{sup 2}/V-s at electron densities of {approx}1 x 10{sup 12} cm{sup -2} for an oxide thickness of 10 nm. Defect density measured using standard C-V techniques was found to be greater with decreasing oxide thickness suggesting a device design trade-off between oxide thickness and quantum dot size. The quantum dot structure is completed using electron beam lithography and poly-silicon etch to form the depletion gates, Fig 1 (a). The accumulation gate is added by introducing a second insulating Al{sub 2}O{sub 3} layer, deposited by atomic layer deposition, followed by an Al top gate deposition, Fig. 1 (b). Initial single electron transistor devices using SiO{sub 2} show significant disorder in structures with relatively large critical dimensions of the order of 200-300 nm, Fig 2. This is not uncommon for large silicon structures and has been cited in the literature [2]. Although smaller structures will likely minimize the effect of disorder and well controlled small Si SETs have been demonstrated [3], the design constraints presented by disorder combined with long term concerns about effects of defects on spin decoherence time (e.g., paramagnetic centers) motivates pursuit of a 2nd generation structure that uses a compound semiconductor approach, an epitaxial SiGe barrier as shown in Fig. 2 (c). SiGe may be used as an electron barrier when combined with tensilely strained Si. The introduction of strained-Si into the double top gated device structure, however, represents additional fabrication challenges. Thermal budget is potentially constrained due to concerns related to strain relaxation. Fabrication details related to the introduction of st

  17. Strained-Si-on-Insulator (SSOI) and SiGe-on-Insulator (SGOI): Fabrication Obstacles and Solutions

    E-Print Network [OSTI]

    Strained-Si-on-Insulator (SSOI) and SiGe-on-Insulator (SGOI): Fabrication Obstacles and Solutions-Si and SiGe-on-insulator were fabricated, combining both the benefits of high-mobility strained-Si and SOI) to oxidized handle wafers. Layer transfer onto insulating handle wafers can be accomplished using grind

  18. INFLUENCE OF SUBSTRATE OFF-CUT ON THE DEFECT STRUCTURE IN RELAXED GRADED Si-Ge/Si LAYERS

    E-Print Network [OSTI]

    INFLUENCE OF SUBSTRATE OFF-CUT ON THE DEFECT STRUCTURE IN RELAXED GRADED Si-Ge/Si LAYERS SRIKANTH B and Engineering, University of California, Los Angeles, CA 90095. ABSTRACT Relaxed graded Si-Ge/Si layers can of these applications requires a different final Ge concentration in the graded Si-Ge layer. With increasing Ge content

  19. SiGe-free strained Si on insulator by wafer bonding and layer transfer T. A. Langdo,a)

    E-Print Network [OSTI]

    SiGe-free strained Si on insulator by wafer bonding and layer transfer T. A. Langdo,a) M. T. Currie; accepted 4 April 2003 SiGe-free strained Si on insulator substrates were fabricated by wafer bonding even after SiGe layer removal. The strain in the structure is thermally stable during 1000 °C anneals

  20. Northwestern University Transportation Center

    E-Print Network [OSTI]

    Bustamante, Fabián E.

    Northwestern University Transportation Center 2011 Business Advisory Committee NUTC #12;#12;I have the pleasure of presenting our Business Advisory Committee members--a distinguished group of transportation industry lead- ers who have partnered with the Transportation Center in advancing the state of knowledge

  1. PalladianDigest Transportation

    E-Print Network [OSTI]

    Farritor, Shane

    PalladianDigest CONNECT. EMPOWER. GROW. Tackling Transportation Challenges Nebraska has been a vital link in the nation's transportation system since the days when carts, wagons to University of Nebraska­Lincoln research. That's fine with UNL transportation researchers, said Larry Rilett

  2. TRANSPORTATION: THE POTENTIAL

    E-Print Network [OSTI]

    Minnesota, University of

    INTERMODAL TRANSPORTATION: THE POTENTIAL AND THE CHALLENGE A Summary Report 2003 #12;June 2003 To the Reader This report summarizes the second James L. Oberstar Forum on Transportation Policy and Technology. Over two days, we explored the chal- lenges and opportunities in intermodal transportation, addressing

  3. Louisiana Transportation Research Center

    E-Print Network [OSTI]

    Harms, Kyle E.

    Louisiana Transportation Research Center LTRC www.ltrc.lsu.edu 2012-13 ANNUALREPORT #12;The Louisiana Transportation Research Center (LTRC) is a research, technology transfer, and training center administered jointly by the Louisiana Department of Transportation and Development (DOTD) and Louisiana State

  4. Introduction to Transportation Planning

    E-Print Network [OSTI]

    Tipple, Brett

    Introduction to Transportation Planning CMP 4710/6710 Fall 2012 3 Credit Hours Room: ARCH 229 on a Saturday night, transportation is not an objective in and of itself, but a means to carry out the functions of daily living (i.e., it's a "derived good"). As a consequence, the transportation systems we build

  5. Rural Intelligent Transportation Systems

    E-Print Network [OSTI]

    Minnesota, University of

    Rural Intelligent Transportation Systems In a technical session at the 2011 NACE conference, Dennis Foderberg of SEH Inc. discussed intelligent transportation systems (ITS) developed by SEH in collaboration with Network Transportation Technologies, Inc. These systems address the problem of crashes on low-volume roads

  6. 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.

  7. SiGe/sSi quantum dot electron spin decoherence dependence on $^{73}$Ge

    E-Print Network [OSTI]

    Witzel, Wayne M; Carroll, Malcolm S

    2011-01-01T23:59:59.000Z

    We theoretically study the nuclear spin induced decoherence of a quantum dot in Si that is confined at a SiGe interface. We calculate decoherence time dependence on $^{73}$Ge in the barrier layer to evaluate the importance of Ge as well as Si enrichment for long decoherence times. We use atomistic tight-binding modeling for an accurate account of the electron wavefunction which is particularly important for determining the contact hyperfine interactions with the Ge nuclear spins. We find decoherence times due to Ge spins at natural concentrations to be milliseconds. This suggests SiGe/sSi quantum dot devices employing enriched Si will require enriched Ge as well in order to benefit from long coherence times. We provide a comparison of $T_2$ times for various fractions of nonzero spin isotopes of Si and Ge.

  8. SiGe/Si quantum dot electron spin decoherence dependence on $^{73}$Ge

    E-Print Network [OSTI]

    Wayne M. Witzel; Rajib Rahman; Malcolm S. Carroll

    2012-05-14T23:59:59.000Z

    We theoretically study the nuclear spin induced decoherence of a quantum dot in Si that is confined at a SiGe interface. We calculate decoherence time dependence on $^{73}$Ge in the barrier layer to evaluate the importance of Ge as well as Si enrichment for long decoherence times. We use atomistic tight-binding modeling for an accurate account of the electron wavefunction which is particularly important for determining the contact hyperfine interactions with the Ge nuclear spins. We find decoherence times due to Ge spins at natural concentrations to be milliseconds. This suggests SiGe/Si quantum dot devices employing enriched Si will require enriched Ge as well in order to benefit from long coherence times. We provide a comparison of $T_2$ times for various fractions of nonzero spin isotopes of Si and Ge.

  9. Monolithic Ge-on-Si lasers for integrated photonics

    E-Print Network [OSTI]

    Liu, Jifeng

    We report room temperature Ge-on-Si lasers with direct gap emission at 1590-1610 nm. Modeling of Ge/Si double heterojunction structures, which is supported by experimental results of Ge/Si LEDs, indicates the feasibility ...

  10. Atomic and electronic structures of rubidium adsorption on Si...

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

    electronic structures of rubidium adsorption on Si(001)(2 x 1) surface: Comparison with CsSi(001) surface. Atomic and electronic structures of rubidium adsorption on Si(001)(2 x...

  11. Germanium: From Its Discovery to SiGe Devices

    E-Print Network [OSTI]

    Haller, E.E.

    2006-01-01T23:59:59.000Z

    From Its Discovery to SiGe Devices E.E. Haller Department ofrapidly rising interest in SiGe alloys, we are just startingstrained and unstrained SiGe multilayer structures [58]. 9.

  12. Transportation YOU 2013 DC Youth Summit WTS Transportation YOU

    E-Print Network [OSTI]

    Minnesota, University of

    Transportation YOU 2013 DC Youth Summit WTS Transportation YOU CTS Research Conference May 21, 2014 Lisa Rasmussen, WTS / Kimley-Horn and Associates, Inc #12;Transportation YOU 2013 DC Youth SummitTransportation YOU 2013 DC Youth Summit Agenda What is Transportation YOU? Transportation YOU ­ WTS Local Chapter

  13. Center for Intermodal Transportation Safety

    E-Print Network [OSTI]

    Fernandez, Eduardo

    Center for Intermodal Transportation Safety and Security Panagiotis Scarlatos, Ph.D., Director Transportation Safety and Security #12;Center for Intermodal Transportation Safety and Security Partners #12 evacuations · Tracking systems for hazardous materials Center for Intermodal Transportation Safety

  14. Public Works Transportation Infrastructure Study

    E-Print Network [OSTI]

    Minnesota, University of

    Public Works Transportation Infrastructure Study Minneapolis City of Lakes Minneapolis Public Works Transportation Infrastructure Study #12;Public Works Transportation Infrastructure Study Minneapolis City Works Transportation Infrastructure Study Minneapolis City of Lakes Background: · Currently, funding

  15. On the origin of strain fluctuation in strained-Si grown on SiGe-on-insulator and SiGe virtual substrates

    SciTech Connect (OSTI)

    Kutsukake, Kentaro; Usami, Noritaka; Ujihara, Toru; Fujiwara, Kozo; Sazaki, Gen; Nakajima, Kazuo [Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577 (Japan)

    2004-08-23T23:59:59.000Z

    We investigated the microscopic strain fluctuation in strained-Si grown on SiGe-on-insulator (SGOI) and SiGe virtual substrates, and clarified the origins of the strain fluctuation in the strained-Si film. A periodic strain fluctuation, which reflects a cross-hatch pattern of the substrate, was observed in the sample on the virtual substrate. On the other hand, a featureless strain fluctuation with suppressed amplitude was observed in the sample on SGOI substrate. By analyzing the correlation of the Raman peak positions of the Si-Si modes in strained-Si and SiGe, the dominant mechanism of the strain fluctuation in the strained Si film was found to be the compositional fluctuation in underlying SiGe for the sample on SGOI, and the strain fluctuation reflecting the cross-hatch pattern for the sample on the virtual substrate, respectively.

  16. Synthesis and Characterization of Structured Si-Carbon Nanocomposite...

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

    Structured Si-Carbon Nanocomposite Anodes and Functional Polymer Binders Synthesis and Characterization of Structured Si-Carbon Nanocomposite Anodes and Functional Polymer Binders...

  17. Rolling up SiGe on insulator

    SciTech Connect (OSTI)

    Cavallo, F.; Songmuang, R.; Ulrich, C.; Schmidt, O. G. [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, D-70569 Stuttgart (Germany)

    2007-05-07T23:59:59.000Z

    SiGe on insulator films of 10-50 nm thickness are fabricated by Ge condensation applying different oxidation times. The layers are released from the substrate by selectively etching the insulator film. Due to the varying Ge composition, the layers bend downward toward the substrate surface and roll up into microtubes. Depending on the Ge condensation, the strain distribution in the SiGe layers varies and allows a scaling of the tube diameters between 1 and 4 {mu}m. Assuming pseudomorphic SiGe layers, the tube diameters are smaller than expected from continuum mechanical theory. This suggests the occurrence of additional strain in the oxidized films.

  18. Deviations from ideal nucleation-limited relaxation in high-Ge content compositionally graded SiGe/Si*

    E-Print Network [OSTI]

    Deviations from ideal nucleation-limited relaxation in high-Ge content compositionally graded SiGe the sudden rise in threading dislocation density in Ge-rich relaxed graded SiGe layers grown at higher growth systems, including relaxed graded SiGe on Si substrates i.e., x Si1-xGex /Si ,1,2 InGaP on GaP substrates

  19. Thermally Processed High-Mobility MOS Thin-Film Transistors on Transferable Single-Crystal Elastically Strain-Sharing Si/SiGe/Si Nanomembranes

    SciTech Connect (OSTI)

    Yuan, H.-C.; Kelly, M. M.; Savage, D. E.; Lagally, M. G.; Celler, G. K.; Zhenqiang, M.

    2008-03-01T23:59:59.000Z

    Demonstration of high-performance MOS thin-film transistors (TFTs) on elastically strain-sharing single-crystal Si/SiGe/Si nanomembranes (SiNMs) that are transferred to foreign substrates is reported. The transferable SiNMs are realized by first growing pseudomorphic SiGe and Si layers on silicon-on-insulator (SOI) substrates, and then, selectively removing the buried oxide (BOX) layer from the SOI. Before the release, only the SiGe layer is compressively strained. Upon release, part of the compressive strain in the SiGe layer is transferred to the thin Si layers, and the Si layers, thus, become tensile strained. Both the initial compressive strain state in the SiGe layer and the final strain sharing state between the SiGe and the Si layers are verified with X-ray diffraction measurements. The TFTs are fabricated employing the conventional high-temperature MOS process on the strain-shared SiNMs that are transferred to an oxidized Si substrate. The transferred strained-sharing SiNMs show outstanding thermal stability and can withstand the high-temperature TFT process on the new host substrate. The strained-channel TFTs fabricated on the new host substrate show high current drive capability and an average electron effective mobility of 270 cm{sup 2}/V ldr s. The results suggest that transferable and thermally stable single-crystal elastically strain- sharing SiNMs can serve as excellent active material for high-speed device application with a simple and scalable transfer method. The demonstration of MOS TFTs on the transferable nanomembranes may create the opportunity for future high-speed Si CMOS heterogeneous integration on any substrate.

  20. Flex Fuel Optimized SI and HCCI Engine

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

    12 439,489 Barriers - Target: Demonstrate a SI and HCCI dual combustion mode engine for a blend of gasoline and E85 for the best fuel economy - Development of a cost...

  1. Si Einstein m'tait cont

    E-Print Network [OSTI]

    Damour, Thibault

    Si Einstein m'était conté Regard sur la rela5vité et le temps Thibault Damour (IHÉS) #12;· EINSTEIN scien5fique, mari, père, ami, amant, musicien, juif, sioniste, homme engagé, navigateur, ... · EINSTEIN et la joie de

  2. EBS Radionuclide Transport Abstraction

    SciTech Connect (OSTI)

    J. Prouty

    2006-07-14T23:59:59.000Z

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment (TSPA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport from a breached waste package. Advective transport occurs when radionuclides that are dissolved or sorbed onto colloids (or both) are carried from the waste package by the portion of the seepage flux that passes through waste package breaches. Diffusive transport occurs as a result of a gradient in radionuclide concentration and may take place while advective transport is also occurring, as well as when no advective transport is occurring. Diffusive transport is addressed in detail because it is the sole means of transport when there is no flow through a waste package, which may dominate during the regulatory compliance period in the nominal and seismic scenarios. The advective transport rate, when it occurs, is generally greater than the diffusive transport rate. Colloid-facilitated advective and diffusive transport is also modeled and is presented in detail in Appendix B of this report.

  3. Size dependent optical properties of Si quantum dots in Si-rich nitride/Si{sub 3}N{sub 4} superlattice synthesized by magnetron sputtering

    SciTech Connect (OSTI)

    So, Yong-Heng; Huang, Shujuan; Conibeer, Gavin; Green, Martin A. [ARC Photovoltaics Centre of Excellence, University of New South Wales, Sydney, New South Wales 2052 (Australia); Gentle, Angus [Physics and Advanced Materials, University of Technology Sydney, P. O. Box 123, Broadway, New South Wales 2007 (Australia)

    2011-03-15T23:59:59.000Z

    A spectroscopic ellipsometry compatible approach is reported for the optical study of Si quantum dots (QDs) in Si-rich nitride/silicon nitride (SRN/Si{sub 3}N{sub 4}) superlattice, which based on Tauc-Lorentz model and Bruggeman effective medium approximation. It is shown that the optical constants and dielectric functions of Si QDs are strongly size dependent. The suppressed imaginary dielectric function of Si QDs exhibits a single broad peak analogous to amorphous Si, which centered between the transition energies E{sub 1} and E{sub 2} of bulk crystalline Si and blue shifted toward E{sub 2} as the QD size reduced. A bandgap expansion observed by the TL model when the size of Si QD reduced is in good agreement with the PL measurement. The bandgap expansion with the reduction of Si QD size is well supported by the first-principles calculations based on quantum confinement.

  4. ZnO/porous-Si and TiO{sub 2}/porous-Si nanocomposite nanopillars

    SciTech Connect (OSTI)

    Wang, Dong, E-mail: dong.wang@tu-ilmenau.de; Yan, Yong; Schaaf, Peter [Chair Materials for Electronics, Institute of Materials Engineering and Institute of Micro- and Nanotechnologies MacroNano, TU Ilmenau, Gustav-Kirchhoff-Str. 5, 98693 Ilmenau (Germany); Sharp, Thomas [Oxford Instruments Plasma Technology Ltd., Yatton, Bristol BS49 4AP (United Kingdom); Schönherr, Sven; Ronning, Carsten [Institute for Solid State Physics, Friedrich Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Ji, Ran [SUSS MicroTec Lithography GmbH, Schleissheimer Str. 90, 85748 Garching (Germany)

    2015-01-01T23:59:59.000Z

    Porous Si nanopillar arrays are used as templates for atomic layer deposition of ZnO and TiO{sub 2}, and thus, ZnO/porous-Si and TiO{sub 2}/porous-Si nanocomposite nanopillars are fabricated. The diffusion of the precursor molecules into the inside of the porous structure occurs via Knudsen diffusion and is strongly limited by the small pore size. The luminescence of the ZnO/porous-Si nanocomposite nanopillars is also investigated, and the optical emission can be changed and even quenched after a strong plasma treatment. Such nanocomposite nanopillars are interesting for photocatalysis and sensors.

  5. Photoconductivity of Si/Ge multilayer structures with Ge quantum dots pseudomorphic to the Si matrix

    SciTech Connect (OSTI)

    Talochkin, A. B., E-mail: tal@thermo.isp.nsc.ru; Chistokhin, I. B. [Russian Academy of Sciences, Rzhanov Institute of Semiconductor Physics, Siberian Branch (Russian Federation)

    2011-07-15T23:59:59.000Z

    Longitudinal photoconductivity spectra of Si/Ge multilayer structures with Ge quantum dots grown pseudomorphically to the Si matrix are studied. Lines of optical transitions between hole levels of quantum dots and Si electronic states are observed. This allowed us to construct a detailed energy-level diagram of electron-hole levels of the structure. It is shown that hole levels of pseudomorphic Ge quantum dots are well described by the simplest 'quantum box' model using actual sizes of Ge islands. The possibility of controlling the position of the long-wavelength photosensitivity edge by varying the growth parameters of Si/Ge structures with Ge quantum dots is determined.

  6. Response of SiC/SiC to Transient Thermal Conditions: A Review

    SciTech Connect (OSTI)

    Jones, Russell H.

    2001-06-30T23:59:59.000Z

    The database on thermal shock behavior of SiC/SiC composites is very limited. The existing data suggests continuous fiber ceramic matrix composites, such as SiC/SiC, exhibit very good thermal shock characteristics but most data was obtained for -Delta T conditions as a result of quenching from an elevated temperature. Thermal shock in a fusion energy system will result from plasma discharge and will result in a +Delta T. One study was reported for SiC/SiC composites given a +Delta T with no loss in strength following 25 cycles at a heating rate of 1700 degrees C/s. Monolithic SiC failed in 1.5 cycles at a heating rate of 1400 degrees C/s. Thermal fatigue test results also suggest that SiC/SiC composites will exhibit little or no degradation for 100's of cycles. It was estimated that radiation could, in an extreme case, cause a reduction in the thermal shock performance from a calculated Delta Tc of 957K to about 300K if the fiber strength is reduced by 50%. Newer composites with greater radiation resistance should have a much smaller change in the Delta Tc.

  7. Straining of SiGe ultrathin films with mesoporous Si substrates

    SciTech Connect (OSTI)

    Boucherif, A.; Guillot, G.; Lysenko, V. [Institut des Nanotechnologies de Lyon INL-UMR5270, CNRS, INSA de Lyon, Universite de Lyon, Villeurbanne F-69621 (France); Blanchard, N. P.; Regreny, P.; Grenet, G. [Institut des Nanotechnologies de Lyon INL-UMR5270, CNRS, Ecole Centrale de Lyon, Universite de Lyon, Ecully F-69134 (France); Marty, O. [Institut des Nanotechnologies de Lyon INL-UMR5270, CNRS, Universite Lyon 1, Universite de Lyon, Villeurbanne F-69622 (France)

    2010-09-27T23:59:59.000Z

    We report on the fabrication and characterization of ultrathin (down to 50 nm) tensile strained SiGe films on mesoporous Si substrates. Low temperature oxidation of the porous substrate relaxes the compressive strain in the as grown monocrystalline (mc) SiGe. Applying this method to a 50 nm thick mc-Si{sub 0.72}Ge{sub 0.28} film, a tensile strain >0.78% can be achieved without compromising crystalline quality and up to 1.45 % without the appearance of cracks.

  8. Dislocation engineering in SiGe heteroepitaxial films on patterned Si (001) substrates

    SciTech Connect (OSTI)

    Gatti, R.; Boioli, F.; Montalenti, F.; Miglio, Leo [L-NESS and Dipartimento di Scienza dei Materiali, Universita degli Studi di Milano-Bicocca, via R. Cozzi 53, I-20125 Milano (Italy); Grydlik, M.; Brehm, M.; Groiss, H.; Glaser, M.; Fromherz, T.; Schaeffler, F. [Institut fuer Halbleiter- und Festkoerperphysik, Johannes Kepler Universitaet, Altenberger Str. 69, A-4040 Linz (Austria)

    2011-03-21T23:59:59.000Z

    We demonstrate dislocation engineering without oxide masks. By using finite element simulations we show how nanopatterning of Si substrates with (111) trenches provides anisotropic elastic relaxation in a SiGe film, generates preferential nucleation sites for dislocation loops, and allows for dislocation trapping, leaving wide areas free of threading dislocations. These predictions are confirmed by atomic force and transmission electron microscopy performed on overcritical Si{sub 0.7}Ge{sub 0.3} films. These were grown by molecular beam epitaxy on a Si(001) substrate patterned with periodic arrays of selectively etched (111)-terminated trenches.

  9. Characterization of SiGe/Si multi-quantum wells for infrared sensing

    SciTech Connect (OSTI)

    Moeen, M.; Salemi, A.; Östling, M.; Radamson, H. H., E-mail: rad@kth.se [School of Information and Communication Technology, KTH Royal Institute of Technology, Stockholm, 16640 Kista (Sweden); Kolahdouz, M. [School of Electrical and Computer Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)] [School of Electrical and Computer Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)

    2013-12-16T23:59:59.000Z

    SiGe epitaxial layers are integrated as an active part in thermal detectors. To improve their performance, deeper understanding of design parameters, such as thickness, well periodicity, quality, and strain amount, of the layers/interfaces is required. Oxygen (2–2500?×?10{sup ?9}?Torr) was exposed prior or during epitaxy of SiGe/Si multilayers. In this range, samples with 10?nTorr oxygen were processed to investigate layer quality and noise measurements. Temperature coefficient of resistance was also measured to evaluate the thermal response. These results demonstrate sensitivity of SiGe-based devices to size and location of defects in the structure.

  10. Radioactive Material Transportation Practices

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2002-09-23T23:59:59.000Z

    Establishes standard transportation practices for Departmental programs to use in planning and executing offsite shipments of radioactive materials including radioactive waste. Does not cancel other directives.

  11. Alternative Fuel Transportation Program

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

    Merit Review: EPAct State and Alternative Fuel Provider Fleets "Alternative Fuel Transportation Program" Dana O'Hara, DOE Ted Sears, NREL Vehicle Technologies Program June 20,...

  12. Transportation and its Infrastructure

    E-Print Network [OSTI]

    2007-01-01T23:59:59.000Z

    Options for Liquid Biofuels Development in Ireland. SEI, 562006: Outlook for advanced biofuels. Energy Policy, 34(17),40 pp. IEA, 2004c: Biofuels for Transport: An International

  13. Transportation Energy Futures

    E-Print Network [OSTI]

    DeLuchi, Mark A.

    1989-01-01T23:59:59.000Z

    TRANSPORTATION ment of Oil Shale Technology. Washing- ton,interest and investments in oil shale, ethanol, coal liquidsbiomass materials, coal, oil shale, tar sands, natural gas,

  14. Sustainable Transportation (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-09-01T23:59:59.000Z

    This document highlights DOE's Office of Energy Efficiency and Renewable Energy's advancements in transportation technologies, alternative fuels, and fuel cell technologies.

  15. 2006 TRANSPORTATION TOMORROW SURVEY JOINT PROGRAM IN TRANSPORTATION

    E-Print Network [OSTI]

    Toronto, University of

    2006 TRANSPORTATION TOMORROW SURVEY JOINT PROGRAM IN TRANSPORTATION UNIVERSITY OF TORONTO 2006 Transportation Tomorrow Survey Data Presentation #12;2006 TRANSPORTATION TOMORROW SURVEY JOINT PROGRAM IN TRANSPORTATION UNIVERSITY OF TORONTO City of Hamilton City of Kawartha Lakes City of Guelph City of Brantford

  16. Comparative analysis of radiation effects on the electroluminescence of Si and SiGe/Si(001) heterostructures with self-assembled Islands

    SciTech Connect (OSTI)

    Krasilnik, Z. F.; Kudryavtsev, K. E. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Kachemtsev, A. N. [Sedakov Scientific-Research Institute (Russian Federation); Lobanov, D. N., E-mail: dima@ipm.sci-nnov.ru; Novikov, A. V. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Obolenskiy, S. V. [Nizhni Novgorod State University (Russian Federation); Shengurov, D. V. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2011-02-15T23:59:59.000Z

    The effect of neutron radiation on the electroluminescence of the Si p-i-n diode containing a multilayered Ge/Si heterostructure with self-assembled nanoislands is studied. In comparison with bulk Si, the diodes containing Ge(Si) nanoislands exhibit a higher radiation hardness of the electroluminescence signal, which is attributed to spatial localization of charge carriers in the Ge/Si nanostructures. The spatial localization of charge carriers impedes their diffusion to radiation defects followed by nonradiative recombination at the defects. The results show the possibilities of using Ge/Si heterostructures with self-assembled nanoislands for the development of optoelectronic devices resistant to radiation.

  17. http://tti.tamu.edu Multi-modal Transportation > Highway Transportation > Trucking > Railroad transportation > Public transit > Rural transportation > Rural transit > Freight

    E-Print Network [OSTI]

    http://tti.tamu.edu Multi-modal Transportation > Highway Transportation > Trucking > Railroad transportation > Public transit > Rural transportation > Rural transit > Freight pipeline transportation >>> Transportation operat > Freight traffic > Commodities > Travel time > Travel demand > http

  18. Graphene formed on SiC under various environments: Comparison of Si-face and C-face

    E-Print Network [OSTI]

    Feenstra, Randall

    of the Si atoms thereby leaving behind excess C atoms which self- assemble into the graphene. Preparation1 Graphene formed on SiC under various environments: Comparison of Si-face and C-face N. Srivastava Abstract The morphology of graphene on SiC {0001} surfaces formed in various environments including ultra

  19. Modeling of implantation and mixing damage during etching of SiO2 over Si in fluorocarbon plasmas

    E-Print Network [OSTI]

    Kushner, Mark

    Modeling of implantation and mixing damage during etching of SiO2 over Si in fluorocarbon plasmas- sions (CD).3 An example of this process is fluorocarbon plasma etching of trenches and vias in SiO2 and stopping on a crystalline Si layer. The fluorocarbon radicals produced in the plasma deposit a polymer

  20. Quantum modeling of thermoelectric performance of strained Si/Ge/Si superlattices using the nonequilibrium Green's function method

    E-Print Network [OSTI]

    Walker, D. Greg

    Quantum modeling of thermoelectric performance of strained Si/Ge/Si superlattices using 2007 The cross-plane thermoelectric performance of strained Si/Ge/Si superlattices is studied from such that thermoelectric performance is independent of layer thickness between 2 and 4 nm germanium barrier layers

  1. Carrier mobilities and process stability of strained Si n-and p-MOSFETs on SiGe virtual substrates

    E-Print Network [OSTI]

    Carrier mobilities and process stability of strained Si n- and p-MOSFETs on SiGe virtual substrates. INTRODUCTION Since the advent of the relaxed graded buffer technique in 1991,1 SiGe alloys have been a proven path to increasing the functionality of the silicon microelectronics platform. SiGe virtual substrates

  2. High-germanium-content SiGe islands formed on compliant oxide by SiGe Haizhou Yina)

    E-Print Network [OSTI]

    High-germanium-content SiGe islands formed on compliant oxide by SiGe oxidation Haizhou Yina and the nonuniformity of the enhanced germanium content during the SiGe oxidation were improved by depositing a silicon was relaxed by lateral expansion of the SiGe islands, showing that dislocations were not required

  3. University of Massachusetts Lowell| iSiS Student Self Service My Advising Center iSiSMyAdvisingCenter

    E-Print Network [OSTI]

    Massachusetts at Lowell, University of

    University of Massachusetts Lowell| iSiS Student Self Service ­My Advising Center iSiSMyAdvisingCenter Student Self Service *New* iSiS My Advising Center The University of Massachusetts Lowell has made enhancements to iSiS Student Self Service. You will notice a new `My Advising

  4. INLAND PORT TRANSPORTATION EVALUATION GUIDE

    E-Print Network [OSTI]

    Texas at Austin, University of

    INLAND PORT TRANSPORTATION EVALUATION GUIDE by Robert Harrison, Center for Transportation Research Transportation Institute, The Texas A&M University System; and Jolanda Prozzi, Center for Transportation Research, The University of Texas at Austin CENTER FOR TRANSPORTATION RESEARCH Bureau of Engineering Research

  5. MAESTRAEN TRANSPORTE ESPECIALIZACINEN

    E-Print Network [OSTI]

    Vásquez, Carlos

    investigaciones que permitan la comprensión de distintos componentes delsistema del transporte así como para Investigación de Operaciones y Redes de transporte Medidas y Administración del Tránsito Tecnologías de

  6. Packaging and Transportation Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2003-04-04T23:59:59.000Z

    To establish safety requirements for the proper packaging and transportation of Department of Energy (DOE)/National Nuclear Security Administration (NNSA) offsite shipments and onsite transfers of hazardous materials and for modal transport. Cancels DOE O 460.1A. Canceled by DOE O 460.1C.

  7. Packaging and Transportation Safety

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2010-05-14T23:59:59.000Z

    The order establishes safety requirements for the proper packaging and transportation of DOE, including NNSA, offsite shipments and onsite transfers of radioactive and other hazardous materials and for modal transportation. Cancels DOE O 460.1B, 5-14-10

  8. Expert systems in transportation

    SciTech Connect (OSTI)

    O'Leary, K.P.

    1988-01-01T23:59:59.000Z

    The 5 papers in the report deal with the following areas: Knowledge representation and software selection for expert-systems design; Expert-system architecture for retaining-wall design; Development of expert-systems technology in the California Department of Transportation; Development of an expert system to assist in the interactive graphic transit system design process; Expert systems development for contingency transportation planing.

  9. Film Si Solar Cells with Nano Si: Cooperative Research and Development Final Report, CRADA Number CRD-09-00356

    SciTech Connect (OSTI)

    Wang, Q.

    2011-05-01T23:59:59.000Z

    Nevada Nanotechnology Center and Si group at NREL will work together to develop a-Si based solar cells with nano-Si technique. We will explore the existing a-Si based film solar cell technology at NREL and nano scale Si technology at Nevada Nanotechnology Center. By exchanging information, we will come; up with some new cell structures using nano-Si. We expect the new a-Si based cells will have optical enhancement or better electronic or optical properties of absorber layer to improve solar cell performance.

  10. Tailored Macroporous SiCN and SiC Structures for High-Temperature Fuel Reforming**

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Tailored Macroporous SiCN and SiC Structures for High-Temperature Fuel Reforming** By In-Kyung Sung such as the reforming of hydrocarbon fuels (e.g., die- sel or JP-8) into hydrogen for use in portable power sources the reaction rate of endothermic reactions (such as the steam reforming of hydrocarbons), at the macroscale

  11. Design, fabrication, and analysis of crystalline Si-SiGe heterostructure thin-film solar cells

    SciTech Connect (OSTI)

    Said, K.; Poortmans, J.; Caymax, M.; Nijs, J.; Debarge, L.; Christoffel, E.; Slaoui, A.

    1999-10-01T23:59:59.000Z

    One possible method to improve the efficiency of crystalline silicon (Ci) solar cells is by alloying with germanium (Ge). Although the improved absorption of the alloy leads to a gain in the current, the reduction of the alloy bandgap causes a loss in voltage, which overrides the increased current of the SiGe alloy solar cell. There has been a number of theoretical studies to circumvent this behavior. However, to date there has been no detailed study, which discusses the technological implementation of these concepts in solar cells. In this paper, the design issues of crystalline Si-SiGe heterostructure will be dealt with in an attempt to reduce the effect of the increased dark current of the alloyed cells, while at the same time sustaining the enhancement in the current. The enhanced back surface field at the back p{sup +}-Si/p-SiGe interface reduces the base component of the recombination current of the heterostructure cell if recombination caused by dislocations is neglected. A higher infrared (IR) response which results in a higher short-circuit current (2 mA/cm{sup 2} higher than a reference Si cell) has been recorded for the Si-Si{sub .9}Ge{sub .1}-thin-film structure of 15 {micro}m thickness. The reduction in dark saturation current, which has been predicted based on the theoretical calculations could not be realized in the heterostructure SiGe/Si cell due to the degradation effect of the misfit dislocations that decreases the bulk lifetime, and increases the interface recombination velocity. In a structure which contains a p{sup +}-SiGe buffer layer, and efficiency of 12.5% is achieved for a SiGe cell with 15 {micro}m thickness without texturing or optical confinement, which is about the same as the Si reference cell with equal active thickness, but with a higher short-circuit current. These results, for the first time, experimentally prove that alloying with Ge offers a higher current and might have a room for improving the efficiency of the multijunction solar cells or dual bandgap cells when SiGe is used to convert the IR-part of the spectrum.

  12. Carbon Clusters as Possible Defects in the SiC-SiO2 Interface

    SciTech Connect (OSTI)

    Dang, Hongli [ORNL; Ramkumar, Gudipati [unknown; Yang, Liu [unknown; Li, Ying [ORNL; Peterson, Heather [unknown; Chisholm, Matthew F [ORNL; Biggerstaff, Trinity Leigh [ORNL; Duscher, Gerd [University of Tennessee, Knoxville (UTK); Wang, Sanwu [ORNL

    2009-01-01T23:59:59.000Z

    High state densities in the band gap of the SiC-SiO2 interface significantly reduce the channel mobilities in SiC-based high-temperature/high-power microelectronics. Investigations of the nature of the interface defects are thus of great importance. While several possible defects including very small carbon clusters with up to four carbon atoms have been identified by first-principles theory, larger carbon clusters as possible defects have attracted less attention. Here, we report first-principles quantum-mechanical calculations for two larger carbon clusters, the C10 ring and the C20 fullerence, in the SiC-SiO2 interface. We find that both carbon clusters introduce significant states in the band gap. The states extend over the entire band gap with higher densities in the upper half of the gap, thus accounting for some of the interface trap densities observed experimentally

  13. Potential variations around grain boundaries in impurity-doped BaSi? epitaxial films evaluated by Kelvin probe force microscopy

    SciTech Connect (OSTI)

    Tsukahara, D.; Baba, M.; Honda, S.; Toko, K. [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Imai, Y. [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); AIST, Tsukuba, Ibaraki 305-8565 (Japan); Hara, K. O.; Usami, N. [Graduate School of Engineering, Nagoya University, Nagoya 464-8603 (Japan); Japan Science and Technology Agency, CREST, Chiyoda, Tokyo 102-0075 (Japan); Werner, J. H. [Institute for Photovoltaics, University of Stuttgart, Stuttgart 70569 (Germany); Suemasu, T. [Institute of Applied Physics, University of Tsukuba, Tsukuba, Ibaraki 305-8573 (Japan); Japan Science and Technology Agency, CREST, Chiyoda, Tokyo 102-0075 (Japan); Institute for Photovoltaics, University of Stuttgart, Stuttgart 70569 (Germany)

    2014-09-28T23:59:59.000Z

    Potential variations around the grain boundaries (GBs) in antimony (Sb)-doped n-type and boron (B)-doped p-type BaSi? epitaxial films on Si(111) were evaluated by Kelvin probe force microscopy. Sb-doped n-BaSi? films exhibited positively charged GBs with a downward band bending at the GBs. The average barrier height for holes was approximately 10 meV for an electron concentration n ? 10¹? cm?³. This downward band bending changed to upward band bending when n was increased to n = 1.8 × 10¹?cm?³. In the B-doped p-BaSi? films, the upward band bending was observed for a hole concentration p ? 10¹?cm?³. The average barrier height for electrons decreased from approximately 25 to 15 meV when p was increased from p = 2.7 × 10¹? to p = 4.0 × 10¹? cm?³. These results are explained under the assumption that the position of the Fermi level E{sub f} at GBs depends on the degree of occupancy of defect states at the GBs, while E{sub f} approached the bottom of the conduction band or the top of the valence band in the BaSi? grain interiors with increasing impurity concentrations. In both cases, such small barrier heights may not deteriorate the carrier transport properties. The electronic structures of impurity-doped BaSi? are also discussed using first-principles pseudopotential method to discuss the insertion sites of impurity atoms and clarify the reason for the observed n-type conduction in the Sb-doped BaSi? and p-type conduction in the B-doped BaSi?.

  14. Stepwise redefinition of the SI base units

    E-Print Network [OSTI]

    Issaev, L K; Khruschov, V V

    2012-01-01T23:59:59.000Z

    The four SI base units are proposed to be redefined in two stages: first, the kilogram, mole and ampere should be defined, and then the kelvin. To realize the redefinition of a base unit of the SI in terms of fundamental physical constant (FPC), a principle of coincidence of their physical dimensions is put forward. Direct applying this principle will lead to the changing of the sets of base and derived units in the new SI. If we want to preserve the continuity of the division between base and derived units in the new and the current SI, the principle is to be generalized with the time dimension factor be included. The status of the mole as the base unit of measurement is considered in the current and new SI. It is proposed to redefine the kilogram using a fixed value of the Avogadro constant and then to redefine the kelvin, after the measurement accuracy of the Boltzmann constant has been increased and agreed with the values of other constants of molecular physics.

  15. N-AND P-TYPE SiGe/Si SUPERLATTICE COOLERS Xiaofeng Fan, Gehong Zeng, Edward Croke

    E-Print Network [OSTI]

    N- AND P-TYPE SiGe/Si SUPERLATTICE COOLERS Xiaofeng Fan, Gehong Zeng, Edward Croke a) , Gerry, 95064 Phone: (805) 893-4235 Fax: (805) 893-7990 Email: fan@opto.ece.ucsb.edu ABSTRACT SiGe is a good of single-element SiGe/Si superlattice coolers of both n- and p-type devices are described for room

  16. Finite element simulation for ultraviolet excimer laser processing of patterned Si/SiGe/Si(100) heterostructures

    SciTech Connect (OSTI)

    Conde, J. C.; Chiussi, S.; Gontad, F.; Gonzalez, P. [Dpto. Fisica Aplicada, University of Vigo, E-36310 Vigo (Spain); Martin, E. [Dpto. Mecanica, Maquinas, Motores Termicos y Fluidos, University of Vigo, E-36310 Vigo (Spain); Serra, C. [CACTI, University of Vigo, E-36310 Vigo (Spain)

    2010-07-05T23:59:59.000Z

    Ultraviolet (UV) Excimer laser assisted processing is an alternative strategy for producing patterned silicon germanium heterostructures. We numerically analyzed the effects caused by pulsed 193 Excimer laser radiation impinging on patterned amorphous hydrogenated silicon (a-Si:H) and germanium (a-Ge:H) bilayers deposited on a crystalline silicon substrate [Si(100)]. The proposed two dimensional axisymmetric numerical model allowed us to estimate the temperature and concentration gradients caused by the laser induced rapid melting and solidification processes. Energy density dependence of maximum melting depth and melting time evolution as well as three dimensional temperature and element distribution have been simulated and compared with experimentally obtained results.

  17. Improving Efficiency and Equity in Transportation Finance

    E-Print Network [OSTI]

    Watts, Michael

    2006-01-01T23:59:59.000Z

    Fueling Transportation Finance. ” Ian W. H. Parry andFueling Transportation Finance. ” Transportation ResearchFueling Transportation Finance: A Primer on the Gas Tax •

  18. Sandia Energy - Transportation Energy Systems Analysis

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

    Transportation Energy Systems Analysis Home Transportation Energy Predictive Simulation of Engines Transportation Energy Systems Analysis Transportation Energy Systems AnalysisTara...

  19. Transportation activity analysis using smartphones

    E-Print Network [OSTI]

    Xiao, Yu

    Transportation activity surveys investigate when, where and how people travel in urban areas to provide information necessary for urban transportation planning. In Singapore, the Land Transport Authority (LTA) carries out ...

  20. Structure and electrical properties of polycrystalline SiGe films grown by molecular beam deposition

    SciTech Connect (OSTI)

    Chistokhin, I. B., E-mail: igor@thermo.isp.nsc.ru; Gutakovskii, A. K.; Deryabin, A. S. [Russian Academy of Sciences, Institute of Semiconductor Physics, Siberian Division (Russian Federation)

    2007-03-15T23:59:59.000Z

    The structural and electrical properties of polycrystalline Si{sub 0.5}Ge{sub 0.5} films 150 nm thick grown by molecular beam deposition at temperatures of 200-550 deg. C on silicon substrates coated with amorphous layers of silicon oxynitride were studied. It is shown that the films consist of a mixture of amorphous and polycrystalline phases. The amorphous phase fraction decreases from {approx}50% in films deposited at 200 deg. C to zero in films grown at 550 deg. C. Subsequent 1-h annealing at a temperature of 550 deg. C results in complete solid-phase crystallization of all films. The electron transport of charge carriers in polycrystalline films occurs by the thermally activated mechanism associated with the energy barrier of {approx}0.2 eV at grain boundaries. Barrier lowering upon additional annealing of SiGe films correlates with an increase in the average grain size.

  1. Coherent phonons in Si/SiGe superlattices Y. Ezzahri,* S. Grauby, J. M. Rampnoux, H. Michel, G. Pernot, W. Claeys, and S. Dilhaire

    E-Print Network [OSTI]

    Coherent phonons in Si/SiGe superlattices Y. Ezzahri,* S. Grauby, J. M. Rampnoux, H. Michel, G longitudinal-acoustic-phonon Bragg reflection. All of these are investigated in Si/SiGe superlattices using

  2. A Novel Algorithm for Solving the Multidimensional Neutron Transport Equation on Massively Parallel Architectures

    SciTech Connect (OSTI)

    Azmy, Yousry

    2014-06-10T23:59:59.000Z

    We employ the Integral Transport Matrix Method (ITMM) as the kernel of new parallel solution methods for the discrete ordinates approximation of the within-group neutron transport equation. The ITMM abandons the repetitive mesh sweeps of the traditional source iterations (SI) scheme in favor of constructing stored operators that account for the direct coupling factors among all the cells' fluxes and between the cells' and boundary surfaces' fluxes. The main goals of this work are to develop the algorithms that construct these operators and employ them in the solution process, determine the most suitable way to parallelize the entire procedure, and evaluate the behavior and parallel performance of the developed methods with increasing number of processes, P. The fastest observed parallel solution method, Parallel Gauss-Seidel (PGS), was used in a weak scaling comparison with the PARTISN transport code, which uses the source iteration (SI) scheme parallelized with the Koch-baker-Alcouffe (KBA) method. Compared to the state-of-the-art SI-KBA with diffusion synthetic acceleration (DSA), this new method- even without acceleration/preconditioning-is completitive for optically thick problems as P is increased to the tens of thousands range. For the most optically thick cells tested, PGS reduced execution time by an approximate factor of three for problems with more than 130 million computational cells on P = 32,768. Moreover, the SI-DSA execution times's trend rises generally more steeply with increasing P than the PGS trend. Furthermore, the PGS method outperforms SI for the periodic heterogeneous layers (PHL) configuration problems. The PGS method outperforms SI and SI-DSA on as few as P = 16 for PHL problems and reduces execution time by a factor of ten or more for all problems considered with more than 2 million computational cells on P = 4.096.

  3. Ag on Si(111) from basic science to application

    SciTech Connect (OSTI)

    Belianinov, Aleksey

    2012-04-04T23:59:59.000Z

    In our work we revisit Ag and Au adsorbates on Si(111)-7x7, as well as experiment with a ternary system of Pentacene, Ag and Si(111). Of particular interest to us is the Si(111)-({radical}3x{radical}3)R30{degree}–Ag (Ag-Si-{radical}3 hereafter). In this thesis I systematically e plore effects of Ag deposition on the Ag-Si-{radical}3 at different temperatures, film thicknesses and deposition fluxes. The generated insight of the Ag system on the Si(111) is then applied to generate novel methods of nanostructuring and nanowire growth. I then extend our expertise to the Au system on the Ag-Si(111) to gain insight into Au-Si eutectic silicide formation. Finally we explore behavior and growth modes of an organic molecule on the Ag-Si interface.

  4. Transportation Economic Assistance Program (Wisconsin)

    Broader source: Energy.gov [DOE]

    The Transportation Economic Assistance Program provides state grants to private business and local governments to improve transportation to projects improving economic conditions and creating or...

  5. Transportation Resources | Advanced Photon Source

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

    Transportation Resources The following means of transportation are available for getting to Argonne. Airports Argonne is located within 25 miles of two major Chicago airports:...

  6. Sandia National Laboratories: Transportation Energy

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

    E. Coli Bacteria Engineered to Eat Switchgrass and Make Transportation Fuels On December 7, 2011, in Energy, JBEI, News, Renewable Energy, Transportation Energy A milestone has...

  7. Sandia National Laboratories: Transportation Energy

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

    JBEI, News, News & Events, Partnership, Renewable Energy, Systems Analysis, Transportation Energy Biofuels hold great promise for the future of transportation energy, but...

  8. Subsurface Flow and Transport | EMSL

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

    subsurface related to contaminant transport, carbon cycling, enhanced oil recovery and carbon dioxide sequestration. See a complete list of Subsurface Flow and Transport...

  9. Transportation and Greenhouse Gas Mitigation

    E-Print Network [OSTI]

    Lutsey, Nicholas P.; Sperling, Dan

    2008-01-01T23:59:59.000Z

    natural gas and liquefied petroleum gas have continued to make small contributions to transportation,transportation actions include electric power sector actions, eg coal to natural gas

  10. Superconnections and Parallel Transport

    E-Print Network [OSTI]

    Dumitrescu, Florin

    2007-01-01T23:59:59.000Z

    This note addresses the construction of a notion of parallel transport along superpaths arising from the concept of a superconnection on a vector bundle over a manifold $M$. A superpath in $M$ is, loosely speaking, a path in $M$ together with an odd vector field in $M$ along the path. We also develop a notion of parallel transport associated with a connection (a.k.a. covariant derivative) on a vector bundle over a \\emph{supermanifold} which is a direct generalization of the classical notion of parallel transport for connections over manifolds.

  11. Direct growth of graphene on Si(111)

    SciTech Connect (OSTI)

    Thanh Trung, Pham, E-mail: phamtha@fundp.ac.be; Joucken, Frédéric; Colomer, Jean-François; Robert, Sporken [Research Center in Physics of Matter and Radiation (PMR), University of Namur (FUNDP), 61 Rue de Bruxelles, 5000 Namur (Belgium); Campos-Delgado, Jessica; Raskin, Jean-Pierre [Electrical Engineering (ELEN), Institute of Information and Communication Technologies, Electronics and Applied Mathematics (ICTEAM), Université catholique de Louvain UCL, 3 place du Levant, Louvain-la-Neuve (Belgium); Hackens, Benoît; Santos, Cristiane N. [Nanoscopic physics (NAPS), Institute of Condensed Matter and Nanosciences (IMCN), Université catholique de Louvain UCL, 2 chemin du Cyclotron, Louvain-la-Neuve (Belgium)

    2014-06-14T23:59:59.000Z

    Due to the need of integrated circuit in the current silicon technology, the formation of graphene on Si wafer is highly desirable, but is still a challenge for the scientific community. In this context, we report the direct growth of graphene on Si(111) wafer under appropriate conditions using an electron beam evaporator. The structural quality of the material is investigated in detail by reflection high energy electron diffraction, Auger electron spectroscopy, X-ray photoemission spectroscopy, Raman spectroscopy, high resolution scanning electron microscopy, atomic force microscopy, and scanning tunneling microscopy. Our experimental results confirm that the quality of graphene is strongly dependent on the growth time during carbon atoms deposition.

  12. EBS Radionuclide Transport Abstraction

    SciTech Connect (OSTI)

    J.D. Schreiber

    2005-08-25T23:59:59.000Z

    The purpose of this report is to develop and analyze the engineered barrier system (EBS) radionuclide transport abstraction model, consistent with Level I and Level II model validation, as identified in ''Technical Work Plan for: Near-Field Environment and Transport: Engineered Barrier System: Radionuclide Transport Abstraction Model Report Integration'' (BSC 2005 [DIRS 173617]). The EBS radionuclide transport abstraction (or EBS RT Abstraction) is the conceptual model used in the total system performance assessment for the license application (TSPA-LA) to determine the rate of radionuclide releases from the EBS to the unsaturated zone (UZ). The EBS RT Abstraction conceptual model consists of two main components: a flow model and a transport model. Both models are developed mathematically from first principles in order to show explicitly what assumptions, simplifications, and approximations are incorporated into the models used in the TSPA-LA. The flow model defines the pathways for water flow in the EBS and specifies how the flow rate is computed in each pathway. Input to this model includes the seepage flux into a drift. The seepage flux is potentially split by the drip shield, with some (or all) of the flux being diverted by the drip shield and some passing through breaches in the drip shield that might result from corrosion or seismic damage. The flux through drip shield breaches is potentially split by the waste package, with some (or all) of the flux being diverted by the waste package and some passing through waste package breaches that might result from corrosion or seismic damage. Neither the drip shield nor the waste package survives an igneous intrusion, so the flux splitting submodel is not used in the igneous scenario class. The flow model is validated in an independent model validation technical review. The drip shield and waste package flux splitting algorithms are developed and validated using experimental data. The transport model considers advective transport and diffusive transport from a breached waste package. Advective transport occurs when radionuclides that are dissolved or sorbed onto colloids (or both) are carried from the waste package by the portion of the seepage flux that passes through waste package breaches. Diffusive transport occurs as a result of a gradient in radionuclide concentration and may take place while advective transport is also occurring, as well as when no advective transport is occurring. Diffusive transport is addressed in detail because it is the sole means of transport when there is no flow through a waste package, which may dominate during the regulatory compliance period in the nominal and seismic scenarios. The advective transport rate, when it occurs, is generally greater than the diffusive transport rate. Colloid-facilitated advective and diffusive transport is also modeled and is presented in detail in Appendix B of this report.

  13. Planetary and meteoritic Mg/Si and d30Si variations inherited from solar nebula chemistry

    E-Print Network [OSTI]

    Dauphas, Nicolas; Burkhardt, Christoph; Kobayashi, Hiroshi; Kurosawa, Kosuke

    2015-01-01T23:59:59.000Z

    The bulk chemical compositions of planets are uncertain, even for major elements such as Mg and Si. This is due to the fact that the samples available for study all originate from relatively shallow depths. Comparison of the stable isotope compositions of planets and meteorites can help overcome this limitation. Specifically, the non-chondritic Si isotope composition of the Earth's mantle was interpreted to reflect the presence of Si in the core, which can also explain its low density relative to pure Fe-Ni alloy. However, we have found that angrite meteorites display a heavy Si isotope composition similar to the lunar and terrestrial mantles. Because core formation in the angrite parent-body (APB) occurred under oxidizing conditions at relatively low pressure and temperature, significant incorporation of Si in the core is ruled out as an explanation for this heavy Si isotope signature. Instead, we show that equilibrium isotopic fractionation between gaseous SiO and solid forsterite at 1370 K in the solar neb...

  14. Transportation 2035 Longview Metropolitan Transportation Plan

    E-Print Network [OSTI]

    Longview Metropolitan Planning Organization

    2009-11-12T23:59:59.000Z

    Owen, MPO Director Melissa Bechtold, Transportation Planner Nalora Moser, Planning Technician MPO TECHNICAL COMMITTEE Karen Owen, City of Longview Fred Marquez, TXDOT-Austin Dale Spitz, TXDOT-Tyler District Debbie Sadler, City of White... Oak Will Buskell, TXDOT-Longview Area Rea Donna Jones, TXDOT-Atlanta District Margie McAllister, TCEQ-Austin Randy Redmond, TXDOT-Tyler District John Paul Jones, Harrison County Keith Bonds, City of Longview Steve Juneau, TXDOT-Marshall...

  15. NREL: Transportation Research - Transportation Secure Data Center

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy: Grid IntegrationReportTransmissionResearchNewsTransportation

  16. Si/SiGe Nanostructures Fabricated by Atomic Force Microscopy Oxidation Xiang-Zheng Bo, Leonid P. Rokhinson, Haizhou Yin, D. C. Tsui, and J. C. Sturm

    E-Print Network [OSTI]

    Rokhinson, Leonid

    Si/SiGe Nanostructures Fabricated by Atomic Force Microscopy Oxidation Xiang-Zheng Bo, Leonid P features in strained SiGe alloys. When directly oxidizing SiGe alloys, minimum line widths of 20nm were on SiGe alloys is slightly less than that on Si. Finally, this method was used to successfully cut

  17. Challenges in epitaxial growth of SiGe buffers on Si (111), (110), and (112) Minjoo L. Lee a,b,*, Dimitri A. Antoniadis a

    E-Print Network [OSTI]

    Haller, Gary L.

    Challenges in epitaxial growth of SiGe buffers on Si (111), (110), and (112) Minjoo L. Lee a The growth of SiGe on surfaces other than Si(001) is of interest in VLSI technology both for realizing novel-mismatch SiGe films grown on Si(111), (110), and (112) possess threading dislocation densities (TDD) >10Â

  18. PBA Transportation Websites

    Broader source: Energy.gov [DOE]

    PBA Transportation Websites presented to the DOE Systems Analysis Workshop held in Washington, D.C. July 28-29, 2004 to discuss and define role of systems analysis in DOE Hydrogen Program.

  19. Transportation and Stationary Power

    E-Print Network [OSTI]

    ) is small. Previous feedback from industry has indicated that existing transportation fuel providers (oil for multiple fuel cell applications, including material handling equipment, backup power, and light- or heavy

  20. ELECTROCHEMICAL POWER FOR TRANSPORTATION

    E-Print Network [OSTI]

    Cairns, Elton J.

    2012-01-01T23:59:59.000Z

    be generated from coal and nuclear energy in contrast to 7%in the use of coal and nuclear energy for transportation andparticularly for coal and nuclear energy utilization, would

  1. Atmospheric Transport of Radionuclides

    SciTech Connect (OSTI)

    Crawford, T.V.

    2003-03-03T23:59:59.000Z

    The purpose of atmospheric transport and diffusion calculations is to provide estimates of concentration and surface deposition from routine and accidental releases of pollutants to the atmosphere. This paper discusses this topic.

  2. Clean Transportation Internship Description

    E-Print Network [OSTI]

    Clean Transportation Internship Description The NC Solar Center at North Carolina State University to other ongoing projects by focusing on time-sensitive tasks. While the main thrust of this internship

  3. Alternative Fuel Transportation Program

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    federal register Monday May 17, 1999 Part II Department of Energy Office of Energy Efficiency and Renewable Energy 10 CFR Part 490 Alternative Fuel Transportation Program; P-series...

  4. Accident resistant transport container

    DOE Patents [OSTI]

    Andersen, John A. (Albuquerque, NM); Cole, James K. (Albuquerque, NM)

    1980-01-01T23:59:59.000Z

    The invention relates to a container for the safe air transport of plutonium having several intermediate wood layers and a load spreader intermediate an inner container and an outer shell for mitigation of shock during a hypothetical accident.

  5. Development of Readout Interconnections for the Si-W Calorimeter of SiD

    SciTech Connect (OSTI)

    Woods, M.; Fields, R.G.; Holbrook, B.; Lander, R.L.; Moskaleva, A.; Neher, C.; Pasner, J.; Tripathi, M.; /UC, Davis; Brau, J.E.; Frey, R.E.; Strom, D.; /Oregon U.; Breidenbach, M.; Freytag, D.; Haller, G.; Herbst, R.; Nelson, T.; /SLAC; Schier, S.; Schumm, B.; /UC, Santa Cruz

    2012-09-14T23:59:59.000Z

    The SiD collaboration is developing a Si-W sampling electromagnetic calorimeter, with anticipated application for the International Linear Collider. Assembling the modules for such a detector will involve special bonding technologies for the interconnections, especially for attaching a silicon detector wafer to a flex cable readout bus. We review the interconnect technologies involved, including oxidation removal processes, pad surface preparation, solder ball selection and placement, and bond quality assurance. Our results show that solder ball bonding is a promising technique for the Si-W ECAL, and unresolved issues are being addressed.

  6. Misfit dislocation gettering by substrate pit-patterning in SiGe films on Si(001)

    SciTech Connect (OSTI)

    Grydlik, Martyna; Groiss, Heiko; Brehm, Moritz; Schaeffler, Friedrich [Institute of Semiconductor and Solid State Physics, Johannes Kepler University Linz, Altenbergerstrasse 69, A-4040 Linz (Austria); Boioli, Francesca; Montalenti, Francesco; Miglio, Leo [L-NESS and Department of Material Science, University of Milano-Bicocca (Italy); Gatti, Riccardo; Devincre, Benoit [LEM, CNRS/ONERA, Chatillon Cedex (France)

    2012-07-02T23:59:59.000Z

    We show that suitable pit-patterning of a Si(001) substrate can strongly influence the nucleation and the propagation of dislocations during epitaxial deposition of Si-rich Si{sub 1-x}Ge{sub x} alloys, preferentially gettering misfit segments along pit rows. In particular, for a 250 nm layer deposited by molecular beam epitaxy at x{sub Ge} = 15%, extended film regions appear free of dislocations, by atomic force microscopy, as confirmed by transmission electron microscopy sampling. This result is quite general, as explained by dislocation dynamics simulations, which reveal the key role of the inhomogeneous distribution in stress produced by the pit-patterning.

  7. B. TRANSPORTATION, CIRCULATION AND PARKING B. TRANSPORTATION, CIRCULATION AND

    E-Print Network [OSTI]

    Mullins, Dyche

    B. TRANSPORTATION, CIRCULATION AND PARKING 231 B. TRANSPORTATION, CIRCULATION AND PARKING on transportation and connectivity issues common to UCSF as a whole. Please refer to Chapter 5, Plans for Existing characteristics specific to each individual UCSF site. DETERMINANTS OF THE 1996 LRDP The transportation

  8. Metropolitan Transportation Plan 2035

    E-Print Network [OSTI]

    Tyler Area Metropolitan Planning Organization

    2009-12-04T23:59:59.000Z

    Adopted by the Tyler Area MPO Policy Committee December 4, 2009 METROPOLITAN TRANSPORTATION PLAN 2035 Revised April 22, 2010 Adopted by the Tyler Area MPO Policy Committee December 4, 2009 Amended/Revised April 22, 2010 Prepared by: Bucher..., Willis, and Ratliff Corporation 1828 East Southeast Loop 323, Suite 202 Tyler, Texas 75701 903.581.7844 This Document Serves as an Update to the Tyler Area Metropolitan Transportation Plan 2030. Portions of that Document were Unchanged and Appear...

  9. Thermoelectric transport in superlattices

    SciTech Connect (OSTI)

    Reinecke, T.L.; Broido, D.A.

    1997-07-01T23:59:59.000Z

    The thermoelectric transport properties of superlattices have been studied using an exact solution of the Boltzmann equation. The role of heat transport along the barrier layers, of carrier tunneling through the barriers, of valley degeneracy and of the well width and energy dependences of the carrier-phonon scattering rates on the thermoelectric figure of merit are given. Calculations are given for Bi{sub 2}Te{sub 3} and for PbTe, and the results of recent experiments are discussed.

  10. Interactive Transportable Architecture

    E-Print Network [OSTI]

    Oliver Irschitz; Priam Givord; Newyork Exit Newyork; Flavia Sparacino

    Transportable architecture which embeds the means to communicate with real or imaginary digital information spaces in a natural fashion offers unprecedented opportunities to make multimedia experiences available to the public almost everywhere. This installation demonstrates an example of interactive transportable architecture which incorporates unencumebered real-time body tracking and gesture recognition to explore a 3-D cityscape and a brain-like web-based information space.

  11. Campus Village Transportation

    E-Print Network [OSTI]

    Hernandez, Emmanuel

    2014-11-19T23:59:59.000Z

    Emmanuel Hernandez THE CAMPUS V ILLAGE : TRANSPORTATION Objective The Campus Village is a new community being constructed in northwest Lawrence with a intergenerational focus in mind. The site will be equipped with housing for students, athletes..., retirement community members, and families. The overall objective of this study was to evaluate the city’s current transportation network and make recommendations on that network to better accommodate the needs of the new property. Specifically, the goal...

  12. Regional Transportation Coordination Study

    E-Print Network [OSTI]

    Golden Crescent Regional Planning Commission

    Committee for this study. ? Develop a coordination public transportation plan ? Identify resources required to develop the plan ? Provide policy guidance to lead the planning and coordination effort Golden Crescent Regional Transit 1... of Texas. This resource will be relied upon for further development of the Intermodal Transportation Terminal. ? FTA Section 5309 (Bus) Discretionary Support ? To assist in meeting the GCRPC?s capital replacement needs. This resource...

  13. Influence of composition and substrate miscut on the evolution of (105)-terminated in-plane Si{sub 1?x}Ge{sub x} quantum wires on Si(001)

    SciTech Connect (OSTI)

    Watzinger, H.; Glaser, M.; Zhang, J. J.; Daruka, I.; Schäffler, F., E-mail: friedrich.schaffler@jku.at [Semiconductor Physics Division, Johannes Kepler University Linz, Altenberger Str. 69, 4040 Linz (Austria)

    2014-07-01T23:59:59.000Z

    Isolated in-plane wires on Si(001) are promising nanostructures for quantum transport applications. They can be fabricated in a catalyst-free process by thermal annealing of self-organized Si{sub 1?x}Ge{sub x} hut clusters. Here, we report on the influence of composition and small substrate miscuts on the unilateral wire growth during annealing at 570?°C. The addition of up to 20% of Si mainly affects the growth kinetics in the presence of energetically favorable sinks for diffusing Ge atoms, but does not significantly change the wire base width. For the investigated substrate miscuts of <0.12°, we find geometry-induced wire tapering, but no strong influence on the wire lengths. Miscuts <0.02° lead to almost perfect quantum wires terminated by virtually step-free (105) and (001) facets over lengths of several 100 nm. Generally, the investigated Si{sub 1?x}Ge{sub x} wires are metastable: Annealing at ?600?°C under otherwise identical conditions leads to the well-known coexistence of Si{sub 1?x}Ge{sub x} pyramids and domes.

  14. Giant monopole resonance strength in Si-28

    E-Print Network [OSTI]

    Youngblood, David H.; Clark, HL; Lui, YW.

    1998-01-01T23:59:59.000Z

    The giant resonance region in Si-28 was studied with inelastic scattering of 240 MeV alpha particles at small angles including 0 degrees. The giant resonance peak extended from E-x=12 MeV to 35 MeV and E0 strength corresponding to 54 +/- 6...

  15. Si Einstein m'tait cont

    E-Print Network [OSTI]

    Damour, Thibault

    Si Einstein m'était conté Regard sur la rela5vité et le temps Jeudi 31 janvier 2013 Gif-sur-YveBe Thibault Damour (IHÉS) #12;· EINSTEIN, navigateur, ... · EINSTEIN et la joie de la pensée « ce qui est essen0el

  16. Globalization and Human Cooperation Supporting Information (SI)

    E-Print Network [OSTI]

    Globalization and Human Cooperation Supporting Information (SI) Nancy R. Buchana Gianluca Grimaldab University, Houston, TX 77005, USA d Department of Psychology, Ohio State University, Columbus, OH 43210, USA e Laboratory for Research in Experimental Economics, University of Valencia, Valencia, Spain 46020 f

  17. Texas Transportation Poll Final report

    E-Print Network [OSTI]

    Texas Transportation Poll Final report PRC 14-16-F #12;2 Texas Transportation Poll Texas A&M Transportation Institute PRC 14-16-F September 2014 Authors Chris Simek Tina Geiselbrecht #12;3 Table of Contents .......................................................................................................................... 8 Transportation Funding

  18. Transportation Systems Engineering GRADUATE STUDIES

    E-Print Network [OSTI]

    Wang, Yuhang

    Transportation Systems Engineering GRADUATE STUDIES TRANSPORTATION SYSTEMS are the building blocks and provides for an improved quality of life. However, transportation systems by their very nature also affect the environment through physical construction and operation of transportation facilities, and through the travel

  19. On-Wafer Integration of Nitrides and Si Devices: Bringing the Power of Polarization to Si

    E-Print Network [OSTI]

    Chung, Jinwook

    The seamless integration of AlGaN/GaN transistors and Si CMOS electronics on the same chip will revolutionize digital and mixed signal electronics. In this talk we describe our group's effort on demonstrating this integration. ...

  20. Step-edge-induced resistance anisotropy in quasi-free-standing bilayer chemical vapor deposition graphene on SiC

    SciTech Connect (OSTI)

    Ciuk, Tymoteusz [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland); Cakmakyapan, Semih; Ozbay, Ekmel [Department of Electrical and Electronics Engineering, Department of Physics, Nanotechnology Research Center, Bilkent University, 06800 Bilkent, Ankara (Turkey); Caban, Piotr; Grodecki, Kacper; Pasternak, Iwona; Strupinski, Wlodek, E-mail: wlodek.strupinski@itme.edu.pl [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Krajewska, Aleksandra [Institute of Electronic Materials Technology, Wolczynska 133, 01-919 Warsaw (Poland); Institute of Optoelectronics, Military University of Technology, Gen. S. Kaliskiego 2, 00-908 Warsaw (Poland); Szmidt, Jan [Institute of Microelectronics and Optoelectronics, Warsaw University of Technology, Koszykowa 75, 00-662 Warsaw (Poland)

    2014-09-28T23:59:59.000Z

    The transport properties of quasi-free-standing (QFS) bilayer graphene on SiC depend on a range of scattering mechanisms. Most of them are isotropic in nature. However, the SiC substrate morphology marked by a distinctive pattern of the terraces gives rise to an anisotropy in graphene's sheet resistance, which may be considered an additional scattering mechanism. At a technological level, the growth-preceding in situ etching of the SiC surface promotes step bunching which results in macro steps ~10 nm in height. In this report, we study the qualitative and quantitative effects of SiC steps edges on the resistance of epitaxial graphene grown by chemical vapor deposition. We experimentally determine the value of step edge resistivity in hydrogen-intercalated QFS-bilayer graphene to be ~190 ??m for step height hS = 10 nm and provide proof that it cannot originate from mechanical deformation of graphene but is likely to arise from lowered carrier concentration in the step area. Our results are confronted with the previously reported values of the step edge resistivity in monolayer graphene over SiC atomic steps. In our analysis, we focus on large-scale, statistical properties to foster the scalable technology of industrial graphene for electronics and sensor applications.

  1. Ge-on-Si laser operating at room temperature

    E-Print Network [OSTI]

    Liu, Jifeng

    Monolithic lasers on Si are ideal for high-volume and large-scale electronic–photonic integration. Ge is an interesting candidate owing to its pseudodirect gap properties and compatibility with Si complementary metal oxide ...

  2. acopladas entre si: Topics by E-print Network

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

    and analysis of lateral SiC N-emitter SiGe P-base Schottky metal-collector (NPM) HBT on SOI Engineering Websites Summary: on SOI M. Jagadesh Kumar *, C. Linga Reddy...

  3. asociat si rezultatele: Topics by E-print Network

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

    and analysis of lateral SiC N-emitter SiGe P-base Schottky metal-collector (NPM) HBT on SOI Engineering Websites Summary: on SOI M. Jagadesh Kumar *, C. Linga Reddy...

  4. ambiant si impactul: Topics by E-print Network

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

    and analysis of lateral SiC N-emitter SiGe P-base Schottky metal-collector (NPM) HBT on SOI Engineering Websites Summary: on SOI M. Jagadesh Kumar *, C. Linga Reddy...

  5. al si application: Topics by E-print Network

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

    that could boost Si-based wireless technology 99 High Performance Polycrystalline SiGe Thin Film Transistors Using Al2O3 Gate Insulator Materials Science Websites Summary:...

  6. Electronic structure of Fe{sub 3}Si on Si(100) substrates

    SciTech Connect (OSTI)

    Lal, Chhagan, E-mail: clsaini52@gmail.com [Centre for Non-Conventional Energy Resources, 14-Vigyan Bhavan, University of Rajasthan, Jaipur-302004 (India); Synchrotron S.C.p.A., SS-14 km, 163.5, in Area Science Park, 34149, Basovizza, Trieste (Italy); International Centre for Theoretical Physics (Italy); Di Santo, G.; Caputo, M.; Panighel, M.; Goldoni, A. [Synchrotron S.C.p.A., SS-14 km, 163.5, in Area Science Park, 34149, Basovizza, Trieste (Italy); Taleatu, B. A. [Department of Physics, Obafemi Awolowo University Ile-Ife (Nigeria); Jain, I. P. [Centre for Non-Conventional Energy Resources, 14-Vigyan Bhavan, University of Rajasthan, Jaipur-302004 (India)

    2014-04-24T23:59:59.000Z

    The improved performance of large-scale integrated circuits (LSIs) by the shrinking of devices is becoming difficult due to physical limitations. Here we report, the growth and formation of Fe{sub 3}Si on Si(100) and characterized by x-ray photoemission, UV photoemission and low energy electron diffraction to study the electronic structure. The results revealed that the DO{sub 3} phase formation is exist and photoemission results also support the electron diffraction outcome.

  7. SiGe quantum dot molecules grown on patterned Si (001) substrates

    SciTech Connect (OSTI)

    Yang Hongbin; Zhang Xiangjiu; Jiang Zuiming; Yang Xinju; Fan Yongliang [Surface Physics Laboratory (National Key Laboratory), Fudan University, Shanghai 200433 (China)

    2008-08-15T23:59:59.000Z

    SiGe quantum dot molecules (QDMs) grown on patterned Si (001) substrates by molecular beam epitaxy were studied. Experimental results showed that the density, the dimension, and the dimension distribution of the SiGe QDMs grown in the windows were dependent on the window size. When the thickness of the Si{sub 0.8}Ge{sub 0.2} film was 40 nm, QDMs only appeared in the unpatterned areas of the Si substrate and none could be found inside the windows of 6x6 {mu}m{sup 2} on the same substrate. However, when the thickness of Si{sub 0.8}Ge{sub 0.2} film was increased to 80 nm, QDMs appeared both inside the windows and in the unpatterned areas, and the density of QDMs was reduced with the decrease in the window size. We attribute these results to the different strain relaxations in different size windows, which are caused by the edge effect of the epitaxial film in the window. Based on these experimental results we discuss the formation and the size stability of the QDMs and conclude that the formation of the SiGe QDM originates from an intrinsic cause of the strain relief mechanism. This work also shows that by means of the edge induced strain relaxation of the epitaxial film in the window, it is possible to reveal the influence of the strain on some physical properties of the SiGe film without changing its Ge atomic fraction.

  8. Fiber/Matrix Interfacial Thermal Conductance Effect on the Thermal Conductivity of SiC/SiC Composites

    SciTech Connect (OSTI)

    Nguyen, Ba Nghiep; Henager, Charles H.

    2013-04-20T23:59:59.000Z

    SiC/SiC composites used in fusion reactor applications are subjected to high heat fluxes and require knowledge and tailoring of their in-service thermal conductivity. Accurately predicting the thermal conductivity of SiC/SiC composites as a function of temperature will guide the design of these materials for their intended use, which will eventually include the effects of 14-MeV neutron irradiations. This paper applies an Eshelby-Mori-Tanaka approach (EMTA) to compute the thermal conductivity of unirradiated SiC/SiC composites. The homogenization procedure includes three steps. In the first step EMTA computes the homogenized thermal conductivity of the unidirectional (UD) SiC fiber embraced by its coating layer. The second step computes the thermal conductivity of the UD composite formed by the equivalent SiC fibers embedded in a SiC matrix, and finally the thermal conductivity of the as-formed SiC/SiC composite is obtained by averaging the solution for the UD composite over all possible fiber orientations using the second-order fiber orientation tensor. The EMTA predictions for the transverse thermal conductivity of several types of SiC/SiC composites with different fiber types and interfaces are compared to the predicted and experimental results by Youngblood et al.

  9. JOINT PROGRAM IN TRANSPORTATION UNIVERSITY OF TORONTO

    E-Print Network [OSTI]

    Toronto, University of

    JOINT PROGRAM IN TRANSPORTATION UNIVERSITY OF TORONTO 2001 TRANSPORTATION TOMORROW SURVEY of Transportation, Ontario Additions in 1996 Regional Municipalities of Niagara, Waterloo Counties of Peterborough not to participate) #12;JOINT PROGRAM IN TRANSPORTATION UNIVERSITY OF TORONTO 2001 TRANSPORTATION TOMORROW SURVEY

  10. Director Position Center for Urban Transportation

    E-Print Network [OSTI]

    Arslan, Hüseyin

    Director Position Center for Urban Transportation The Center for Urban Transportation Research for state policymakers, transportation agencies, transportation professionals and the public. CUTR conducts of Transportation's Federal Transit Administration and Federal Highway Administration, the Florida Department

  11. Delaware Transportation Infrastructure Forum Problem Identification Statements

    E-Print Network [OSTI]

    Firestone, Jeremy

    2013 Delaware Transportation Infrastructure Forum Problem Identification Statements Sponsored by The Delaware Center for Transportation and the Delaware Department of Transportation Delaware Center for Transportation Your main resource for transportation education and research Identifying Important Issues Related

  12. Ge/SiGe quantum wells on Si(111): Growth, structural, and optical properties

    SciTech Connect (OSTI)

    Gatti, E., E-mail: eleonora.gatti@mater.unimib.it; Pezzoli, F.; Grilli, E. [L-NESS and Dipartimento di Scienza dei Materiali, Università di Milano Bicocca, via Cozzi 55, I-20125 Milano (Italy); Isa, F.; Chrastina, D.; Isella, G. [L-NESS and Dipartimento di Fisica, Politecnico di Milano, Polo di Como, via Anzani 42, I - 22100 Como (Italy); Müller Gubler, E. [Electron Microscopy Center of ETH Zürich (EMEZ), August-Piccard-Hof 1, CH-8093 Zürich (Switzerland)

    2014-07-28T23:59:59.000Z

    The epitaxial growth of Ge/Si{sub 0.15}Ge{sub 0.85} multiple quantum wells (MQWs) on Si(111) substrates is demonstrated. A 3??m thick reverse, double-step virtual substrate with a final composition of Si{sub 0.10}Ge{sub 0.90} has been employed. High resolution XRD, TEM, AFM and defect etching analysis has been used for the study of the structural properties of the buffer and of the QWs. The QW stack is characterized by a threading dislocation density of about 3?×?10{sup 7?}cm{sup ?2} and an interdiffusion layer at the well/barrier interface of 2.1?nm. The quantum confined energy levels of this system have been calculated using the k·p and effective mass approximation methods. The Ge/Si{sub 0.15}Ge{sub 0.85} MQWs have been characterized through absorption and photoluminescence measurements. The optical spectra have been compared with those of Ge/Si{sub 0.15}Ge{sub 0.85} QWs grown on Si(001) through a thick graded virtual substrate.

  13. Plasma hydrogenation of strain-relaxed SiGe/Si heterostructure for layer transfer

    SciTech Connect (OSTI)

    Chen Peng; Chu, Paul K.; Hoechbauer, T.; Nastasi, M.; Buca, D.; Mantl, S.; Theodore, N. David; Alford, T.L.; Mayer, J.W.; Loo, R.; Caymax, M.; Cai, M.; Lau, S.S. [Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon, Hong Kong (China); Los Alamos National Laboratory, Los Alamos, New Mexico, 87545 (United States); Institut fuer Schichten und Grenzflaechen and cni-Center of Nanoelectronic Systems for Information Technology, Forschungszentrum Juelich, D-52425 Juelich (Germany); Advanced Products Research and Development Laboratory, Freescale Semiconductor Incorporated, 2100 East Elliot Road, Tempe, Arizona 85284 (United States); Department of Chemical and Materials Engineering, Arizona State University, Tempe, Arizona 85287 (United States); IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); University of California at San Diego, San Diego, California 92093 (United States)

    2004-11-22T23:59:59.000Z

    The use of plasma hydrogenation for relaxed SiGe layer transfer is demonstrated. It is found that the interface of a strain-relaxed SiGe/Si heterostructure is effective in trapping H during plasma hydrogenation. Long microcracks observed at the interface due to the trapping of indiffused H indicate the distinct possibility of transferring the overlayer using the ion-cutting technique. Our results suggest that interfacial defects induced by the He implantation relaxation process trap the indiffusing H atoms and lead to interfacial cracks during hydrogenation or upon postannealing at higher temperatures. It is further noted that trapping of H at the interface is possible only in strain-relaxed structures. Without strain relaxation, H atoms introduced by plasma hydrogenation get trapped just below the sample surface and form a band of shallow platelets. Without the need for high-dose high-energy ion implantation, our results suggest an effective way for high-quality strain-relaxed SiGe layer transfer. The technique has potential for application in the fabrication of SiGe-on-insulator strained Si epitaxial layer and related structures.

  14. Monolithic Ge/Si Avalanche Photodiodes Yimin Kanga*

    E-Print Network [OSTI]

    Bowers, John

    Monolithic Ge/Si Avalanche Photodiodes Yimin Kanga* , Mike Morsea , Mario J. Panicciaa , Moshe, Charlottesville, VA 22904, USA Abstract: We demonstrate mesa-type and waveguide-type Ge/Si avalanche photodiodes. Research on the Ge/Si photodiodes, one of the fundamental components needed for building integrated silicon

  15. SiGe thin-film structures for solar cells

    SciTech Connect (OSTI)

    Bremond, G.; Daami, A.; Laugier, A. [Inst. National des Sciences Appliquees de Lyon, Villeurbanne (France). Lab. de Physique de la Matiere] [and others

    1998-12-31T23:59:59.000Z

    In order to study their applicability as the active base material in Si thin crystalline film solar cell technology, SiGe relaxed layers grown by Liquid Phase Epitaxy (LPE) and Chemical Vapor Deposition (CVD) on Si substrates are investigated by optical and electrical measurements (TEM, EXD, PL, EBIC). The main results of this work is to point out the improvement of the SiGe active base layer by using smooth Ge graded SiGe buffer layer and remote plasma hydrogenation. TEM, EXD, PL experiments show the effect of the Ge graded buffer layer grown using LPE, by confining the threading dislocations in the SiGe buffer layer close to the Si/SiGe interface. EBIC measurements reveal low recombination activity of dislocations at 300 K providing the diffusion length exceeds the 15 {micro}m layer thickness. The enhanced luminescence of SiGe near bandgap indicates that remote plasma hydrogenation induces a decrease of the non-radiative recombination pathways due to dislocations on CVD layers where defect recombinations dominate as indicated by EBIC measurements. This study points out the importance of controlling relaxed SiGe layers with good minority carrier recombination quality as a key issue for the optimization of new SiGe/Si based solar cells.

  16. Characterization of SiO{sub 2}/SiN{sub x} gate insulators for graphene based nanoelectromechanical systems

    SciTech Connect (OSTI)

    Tóvári, E.; Csontos, M., E-mail: csontos@dept.phy.bme.hu; Kriváchy, T.; Csonka, S. [Department of Physics, Budapest University of Technology and Economics and Condensed Matter Research Group of the Hungarian Academy of Sciences, Budafoki út 8, H-1111 Budapest (Hungary); Fürjes, P. [MEMS Lab, Institute for Technical Physics and Materials Science, RCNS, HAS, Konkoly-Thege út 29-33, H-1121 Budapest (Hungary)

    2014-09-22T23:59:59.000Z

    The structural and magnetotransport characterization of graphene nanodevices exfoliated onto Si/SiO{sub 2}/SiN{sub x} heterostructures are presented. Improved visibility of the deposited flakes is achieved by optimal tuning of the dielectric film thicknesses. The conductance of single layer graphene Hall-bar nanostructures utilizing SiO{sub 2}/SiN{sub x} gate dielectrics were characterized in the quantum Hall regime. Our results highlight that, while exhibiting better mechanical and chemical stability, the effect of non-stoichiometric SiN{sub x} on the charge carrier mobility of graphene is comparable to that of SiO{sub 2}, demonstrating the merits of SiN{sub x} as an ideal material platform for graphene based nanoelectromechanical applications.

  17. FRET-Labeled siRNA Probes for Tracking Assembly and Disassembly of siRNA-Nanocomplexes

    E-Print Network [OSTI]

    Alabi, Christopher Akinleye

    The assembly, stability, and timely disassembly of short interfering RNA (siRNA) nanocomplexes have the potential to affect the efficiency of siRNA delivery and gene silencing. As such, the design of new probes that can ...

  18. Efficient Transportation Decision Public Web Site: Bridging the Gap Between Transportation Planning and the Public

    E-Print Network [OSTI]

    Roaza, Ruth

    2007-01-01T23:59:59.000Z

    for accomplishing transportation planning and projectprocess – the Efficient Transportation Decision Making (Process - is to make transportation decisions more quickly

  19. Electronic transport in graphene-based heterostructures

    SciTech Connect (OSTI)

    Tan, J. Y.; Avsar, A.; Balakrishnan, J.; Taychatanapat, T.; O'Farrell, E. C. T.; Eda, G.; Castro Neto, A. H. [Graphene Research Center, National University of Singapore, Singapore 117542 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); Koon, G. K. W.; Özyilmaz, B., E-mail: barbaros@nus.edu.sg [Graphene Research Center, National University of Singapore, Singapore 117542 (Singapore); Department of Physics, National University of Singapore, Singapore 117542 (Singapore); NanoCore, National University of Singapore, Singapore 117576 (Singapore); Watanabe, K.; Taniguchi, T. [National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044 (Japan)

    2014-05-05T23:59:59.000Z

    While boron nitride (BN) substrates have been utilized to achieve high electronic mobilities in graphene field effect transistors, it is unclear how other layered two dimensional (2D) crystals influence the electronic performance of graphene. In this Letter, we study the surface morphology of 2D BN, gallium selenide (GaSe), and transition metal dichalcogenides (tungsten disulfide (WS{sub 2}) and molybdenum disulfide (MoS{sub 2})) crystals and their influence on graphene's electronic quality. Atomic force microscopy analysis shows that these crystals have improved surface roughness (root mean square value of only ?0.1?nm) compared to conventional SiO{sub 2} substrate. While our results confirm that graphene devices exhibit very high electronic mobility (?) on BN substrates, graphene devices on WS{sub 2} substrates (G/WS{sub 2}) are equally promising for high quality electronic transport (????38?000 cm{sup 2}/V s at room temperature), followed by G/MoS{sub 2} (????10?000 cm{sup 2}/V s) and G/GaSe (????2200 cm{sup 2}/V s). However, we observe a significant asymmetry in electron and hole conduction in G/WS{sub 2} and G/MoS{sub 2} heterostructures, most likely due to the presence of sulphur vacancies in the substrate crystals. GaSe crystals are observed to degrade over time even under ambient conditions, leading to a large hysteresis in graphene transport making it a less suitable substrate.

  20. Progress in Solving the Elusive Ag Transport Mechanism in TRISO Coated Particles: What is new?

    SciTech Connect (OSTI)

    Isabella Van Rooyen

    2014-10-01T23:59:59.000Z

    The TRISO particle for HTRs has been developed to an advanced state where the coating withstands internal gas pressures and retains fission products during irradiation and under postulated accidents. However, one exception is Ag that has been found to be released from high quality TRISO coated particles when irradiated and can also during high temperature accident heating tests. Although out- of- pile laboratory tests have never hither to been able to demonstrate a diffusion process of Ag in SiC, effective diffusion coefficients have been derived to successfully reproduce measured Ag-110m releases from irradiated HTR fuel elements, compacts and TRISO particles It was found that silver transport through SiC does not proceed via bulk volume diffusion. Presently grain boundary diffusion that may be irradiation enhanced either by neutron bombardment or by the presence of fission products such as Pd, are being investigated. Recent studies of irradiated AGR-1 TRISO fuel using scanning transmission electron microscopy (STEM), transmission kukuchi diffraction (TKD) patterns and high resolution transmission electron microscopy (HRTEM) have been used to further the understanding of Ag transport through TRISO particles. No silver was observed in SiC grains, but Ag was identified at triple-points and grain boundaries of the SiC layer in the TRISO particle. Cadmium was also found in some of the very same triple junctions, but this could be related to silver behavior as Ag-110m decays to Cd-110. Palladium was identified as the main constituent of micron-sized precipitates present at the SiC grain boundaries and in most SiC grain boundaries and the potential role of Pd in the transport of Ag will be discussed.

  1. Method for enhancing growth of SiO.sub.2 in Si by the implantation of germanium

    DOE Patents [OSTI]

    Holland, Orin W. (Oak Ridge, TN); Fathy, Dariush (Knoxville, TN); White, Clark W. (Oak Ridge, TN)

    1990-04-24T23:59:59.000Z

    A method for enhancing the conversion of Si to SiO.sub.2 in a directional fashion wherein steam or wet oxidation of Si is enhanced by the prior implantation of Ge into the Si. The unique advantages of the Ge impurity include the directional enhancement of oxidation and the reduction in thermal budget, while at the same time, Ge is an electrically inactive impurity.

  2. Absence of quantum confinement effects in the photoluminescence of Si{sub 3}N{sub 4}–embedded Si nanocrystals

    SciTech Connect (OSTI)

    Hiller, D., E-mail: daniel.hiller@imtek.uni-freiburg.de; Zelenina, A.; Gutsch, S.; Zacharias, M. [Faculty of Engineering, IMTEK, Albert-Ludwigs-University Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg (Germany); Dyakov, S. A. [Department of Electronic and Electrical Engineering, Trinity College Dublin, Dublin 2 (Ireland); Optics and Photonics, School of Information and Communication Technology, Royal Institute of Technology (KTH), Electrum 229, Kista SE-16440 (Sweden); López-Conesa, L.; López-Vidrier, J.; Peiró, F.; Garrido, B. [MIND-IN2UB, Departament d'Electrònica, Universitat de Barcelona, C. Martí i Franquès, 1, 08028 Barcelona (Spain); Estradé, S. [MIND-IN2UB, Departament d'Electrònica, Universitat de Barcelona, C. Martí i Franquès, 1, 08028 Barcelona (Spain); CCiT, Scientific and Technical Centers, Universitat de Barcelona, C/Lluís Solé i Sabaris 1, 08028 Barcelona (Spain); Valenta, J.; Ko?ínek, M.; Trojánek, F.; Malý, P. [Faculty of Mathematics and Physics, Department of Chemical Physics and Optics, Charles University in Prague, Ke Karlovu 3, CZ-12116 Prague 2 (Czech Republic); Schnabel, M.; Weiss, C.; Janz, S. [Fraunhofer-Institut für Solare Energiesysteme ISE, Heidenhofstr. 2, 79110 Freiburg (Germany)

    2014-05-28T23:59:59.000Z

    Superlattices of Si-rich silicon nitride and Si{sub 3}N{sub 4} are prepared by plasma-enhanced chemical vapor deposition and, subsequently, annealed at 1150?°C to form size-controlled Si nanocrystals (Si NCs) embedded in amorphous Si{sub 3}N{sub 4}. Despite well defined structural properties, photoluminescence spectroscopy (PL) reveals inconsistencies with the typically applied model of quantum confined excitons in nitride-embedded Si NCs. Time-resolved PL measurements demonstrate 10{sup 5} times faster time-constants than typical for the indirect band structure of Si NCs. Furthermore, a pure Si{sub 3}N{sub 4} reference sample exhibits a similar PL peak as the Si NC samples. The origin of this luminescence is discussed in detail on the basis of radiative defects and Si{sub 3}N{sub 4} band tail states in combination with optical absorption measurements. The apparent absence of PL from the Si NCs is explained conclusively using electron spin resonance data from the Si/Si{sub 3}N{sub 4} interface defect literature. In addition, the role of Si{sub 3}N{sub 4} valence band tail states as potential hole traps is discussed. Most strikingly, the PL peak blueshift with decreasing NC size, which is often observed in literature and typically attributed to quantum confinement (QC), is identified as optical artifact by transfer matrix method simulations of the PL spectra. Finally, criteria for a critical examination of a potential QC-related origin of the PL from Si{sub 3}N{sub 4}-embedded Si NCs are suggested.

  3. Transportation Institutional Plan

    SciTech Connect (OSTI)

    Not Available

    1986-08-01T23:59:59.000Z

    This Institutional Plan is divided into three chapters. Chapter 1 provides background information, discusses the purposes of the Plan and the policy guidance for establishing the transportation system, and describes the projected system and the plans for its integrated development. Chapter 2 discusses the major participants who must interact to build the system. Chapter 3 suggests mechanisms for interaction that will foster wide participation in program planning and implementation and provides a framework for managing and resolving the issues related to development and operation of the transportation system. A list of acronyms and a glossary are included for the reader's convenience. Also included in this Plan are four appendices. Of particular importance is Appendix A, which includes detailed discussion of specific transportation issues. Appendices B, C, and D provide supporting material to assist the reader in understanding the roles of the involved institutions.

  4. Intermodal Transportation, USACE Style

    SciTech Connect (OSTI)

    Grumski, K. M.; Coutts, P. W.

    2002-02-27T23:59:59.000Z

    The US Army Corps of Engineers (USACE) has developed project management techniques with a proven track record for safe and successful results for constructing large scale and massive projects such as improving our nations water transportation systems, flood control, bridges and dams. Applying many of these techniques to the Formerly Utilized Sites Remedial Action Program (FUSRAP) managed by USACE to remediate the environment is achieving the same safe and successful results as their construction projects. This paper examines the additional economics and improved safety results of using intermodal containers and a combination of rail and truck transportation conveyances to transport the contaminated soil and debris from the Linde FUSRAP site, located in Tonawanda, New York.

  5. Experimental constraints on transport

    SciTech Connect (OSTI)

    Luce, T.C.; Petty, K.H.; Burrell, K.H.; Forest, C.B.; Gohil, P.; Groebner, R.J.; De Haas, J.C.M.; James, R.A.; Makowski, M.A.

    1994-12-01T23:59:59.000Z

    Characterization of the cross-field energy transport in magnetic confinement experiments in a manner applicable to the accurate assessment of future machine performance continues to be a challenging goal. Experimental results from the DIII-D tokamak in the areas of dimensionless scaling and non-diffusive transport represent progress toward this goal. Dimensionless scaling shows how beneficial the increase in machine size and magnetic field is for future devices. The experiments on DIII-D are the first to determine separately the electron and ion scaling with normalized gyroradius {rho}{sub *}; the electrons scale as expected from gyro-Bohm class theories, while the ions scale consistent with the Goldston empirical scaling. This result predicts an increase in transport relative to Bohm diffusion as {rho}{sub *} decreases in future devices. The existence of distinct {rho}{sub *} scalings for ions and electrons cautions against a physical interpretation of one-fluid or global analysis. The second class of experiments reported here are the first to demonstrate the existence of non-diffusive energy transport. Electron cyclotron heating was applied at the half radius; the electron temperature profile remains substantially peaked. Power balance analysis indicates that heat must flow in the direction of increasing temperature, which is inconsistent with purely diffusive transport. The dynamics of electron temperature perturbations indicate the presence in the heat flux of a term dependent on temperature rather than its gradient. These two observations strongly constrain the types of models which can be applied to cross-field heat transport.

  6. Carbon incorporation for strain compensation during solid phase epitaxial recrystallization of SiGe on Si at 500600 C

    E-Print Network [OSTI]

    Florida, University of

    Carbon incorporation for strain compensation during solid phase epitaxial recrystallization of SiGe in the MBE grown SiGe layers prior to regrowth at moderate temperatures 500­700 °C has three main effects­10 and photodetectors.11,12 The addition of germa- nium to silicon allows the resulting SiGe layer to have a reduced

  7. Smart vehicular transportation systems

    SciTech Connect (OSTI)

    Little, C.Q.; Wilson, C.W.

    1997-05-01T23:59:59.000Z

    This work builds upon established Sandia intelligent systems technology to develop a unique approach for the integration of intelligent system control into the US Highway and urban transportation systems. The Sandia developed concept of the COPILOT controller integrates a human driver with computer control to increase human performance while reducing reliance on detailed driver attention. This research extends Sandia expertise in sensor based, real-time control of robotics systems to high speed transportation systems. Knowledge in the form of maps and performance characteristics of vehicles provides the automatic decision making intelligence needed to plan optimum routes, maintain safe driving speeds and distances, avoid collisions, and conserve fuel.

  8. Si{sup +} ion implantation for strain relaxation of pseudomorphic Si{sub 1-x}Ge{sub x}/Si(100) heterostructures

    SciTech Connect (OSTI)

    Buca, D.; Minamisawa, R. A.; Trinkaus, H.; Hollaender, B.; Mantl, S. [Institute of Bio- and Nanosystems (IBN1-IT), Forschungszentrum Juelich, D-52425 Juelich, Germany and JARA-Fundamentals of Future Information Technology (Germany); Loo, R.; Caymax, M. [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium)

    2009-06-01T23:59:59.000Z

    A mechanism of strain relief of pseudomorphic Si{sub 1-x}Ge{sub x}/Si(100) heterostructures by Si{sup +} ion implantation and annealing is proposed and analytically modeled. The degree of strain relaxation is presented as a function of Ge content and implantation and annealing parameters. Rutherford backscattering spectrometry/channeling, Raman spectroscopy, and transmission electron microscopy are employed to quantify the efficiency of the relaxation process and to examine the quality of the samples, respectively. The mechanism and the conditions for strain relaxation are discussed in terms of dislocation loop formation in the implanted range with emphasis on loop formation in the compressively strained SiGe layer. The detrimental effect of local amorphization of the SiGe layer on its relaxation and on strain transfer to the Si-cap layer is also addressed.

  9. Magnetoresistivity and acoustoelectronic effects in a tilted magnetic field in p-Si/SiGe/Si structures with an anisotropic g factor

    SciTech Connect (OSTI)

    Drichko, I. L., E-mail: Irina.L.Drichko@mail.ioffe.ru; Smirnov, I. Yu. [Russian Academy of Sciences, Ioffe Physicotechnical Institute (Russian Federation); Suslov, A. V. [National High Magnetic Field Laboratory (United States); Mironov, O. A. [University of Warwick Science Park, Warwick SEMINANO R and D Centre (United Kingdom); Leadley, D. R. [University of Warwick Science Park, Department of Physics (United Kingdom)

    2010-09-15T23:59:59.000Z

    Magnetoresistivity {rho}{sub xx} and {rho}{sub xy} and the acoustoelectronic effects are measured in p-Si/SiGe/Si with an impurity concentration p = 1.99 x 10{sup 11} cm{sup -2} in the temperature range 0.3-2.0 K and an tilted magnetic field up to 18 T. The dependence of the effective g factor on the angle of magnetic field tilt {theta} to the normal to the plane of a two-dimensional p-Si/SiGe/Si channel is determined. A first-order ferromagnet-paramagnet phase transition is observed in the magnetic fields corresponding to a filling factor {nu} = 2 at {theta} {approx} 59{sup o}-60{sup o}.

  10. Si-based RF MEMS components.

    SciTech Connect (OSTI)

    Stevens, James E.; Nordquist, Christopher Daniel; Baker, Michael Sean; Fleming, James Grant; Stewart, Harold D.; Dyck, Christopher William

    2005-01-01T23:59:59.000Z

    Radio frequency microelectromechanical systems (RF MEMS) are an enabling technology for next-generation communications and radar systems in both military and commercial sectors. RF MEMS-based reconfigurable circuits outperform solid-state circuits in terms of insertion loss, linearity, and static power consumption and are advantageous in applications where high signal power and nanosecond switching speeds are not required. We have demonstrated a number of RF MEMS switches on high-resistivity silicon (high-R Si) that were fabricated by leveraging the volume manufacturing processes available in the Microelectronics Development Laboratory (MDL), a Class-1, radiation-hardened CMOS manufacturing facility. We describe novel tungsten and aluminum-based processes, and present results of switches developed in each of these processes. Series and shunt ohmic switches and shunt capacitive switches were successfully demonstrated. The implications of fabricating on high-R Si and suggested future directions for developing low-loss RF MEMS-based circuits are also discussed.

  11. Positron annihilation studies of fluorine-vacancy complexes in Si and SiGe

    SciTech Connect (OSTI)

    Edwardson, C. J.; Coleman, P. G. [Department of Physics, University of Bath, Bath BA2 7AY (United Kingdom); El Mubarek, H. A. W.; Gandy, A. S. [School of Electrical and Electronic Engineering, University of Manchester, Manchester, M13 9PL (United Kingdom)

    2012-04-01T23:59:59.000Z

    The formation of fluorine-vacancy (FV) complexes in strained Si-SiGe-Si multilayer structures and relaxed SiGe layers of varying Ge content has been investigated using variable-energy positron annihilation spectroscopy, including Doppler-broadened spectra ratio curves. It has been found that in all sample types there are two distinct regions defined only by the damage created by the implanted F ions. The first, shallower region (from the surface to a depth of {approx}200 nm) was found to contain a mixture of undecorated vacancies and FV complexes; there is no correlation between the vacancy or F concentration in this region and the Ge content. The multi-layer samples may also have O contamination that is not present in the relaxed samples. The second region (at depths {approx}200-440 nm) contains primarily FV complexes in all samples. In the multi-layer samples secondary ion mass spectrometry (SIMS) results show peaks of F accumulating in, or at the interfaces of, each SiGe multi-layer; the FV complexes, however, are distributed over depths similar to those in the relaxed samples, with some localization at the SiGe layer located within the second region. The positron response is primarily to FV complexes formed by the F implant in all samples. The F: FV ratios are approximately 3-7: 1 in the relaxed samples. Positrons appear to be relatively insensitive to the largest of the F SIMS peaks which lies beyond the second region. This is probably because the F has filled all the open volume at the SiGe layer, leaving no positron trapping sites.

  12. Thermodynamic and kinetic control of the lateral Si wire growth

    SciTech Connect (OSTI)

    Dedyulin, Sergey N., E-mail: sdedyuli@uwo.ca; Goncharova, Lyudmila V. [Department of Physics and Astronomy, The University of Western Ontario, 1151 Richmond St., London, Ontario N6A 3K7 (Canada)

    2014-03-24T23:59:59.000Z

    Reproducible lateral Si wire growth has been realized on the Si (100) surface. In this paper, we present experimental evidence showing the unique role that carbon plays in initiating lateral growth of Si wires on a Si (100) substrate. Once initiated in the presence of ?5 ML of C, lateral growth can be achieved in the range of temperatures, T?=?450–650?°C, and further controlled by the interplay of the flux of incoming Si atoms with the size and areal density of Au droplets. Critical thermodynamic and kinetic aspects of the growth are discussed in detail.

  13. Transport Experiments on 2D Correlated Electron Physics in Semiconductors

    SciTech Connect (OSTI)

    Tsui, Daniel

    2014-03-24T23:59:59.000Z

    This research project was designed to investigate experimentally the transport properties of the 2D electrons in Si and GaAs, two prototype semiconductors, in several new physical regimes that were previously inaccessible to experiments. The research focused on the strongly correlated electron physics in the dilute density limit, where the electron potential energy to kinetic energy ratio rs>>1, and on the fractional quantum Hall effect related physics in nuclear demagnetization refrigerator temperature range on samples with new levels of purity and controlled random disorder.

  14. Time-resolved photoluminescence from self-assembled Ge(Si) islands in multilayer SiGe/Si and SiGe/SOI structures

    SciTech Connect (OSTI)

    Yablonskiy, A. N., E-mail: yablonsk@ipm.sci-nnov.ru; Baidakova, N. A. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)] [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Novikov, A. V. [Lobachevskyi University of Nizhni Novgorod, Physical-Technical Research Institute (Russian Federation)] [Lobachevskyi University of Nizhni Novgorod, Physical-Technical Research Institute (Russian Federation); Lobanov, D. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)] [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2013-11-15T23:59:59.000Z

    The results of a study of the spectral and temporal characteristics of the photoluminescence (PL) from multilayer structures with self-assembled Ge(Si) islands grown on silicon and 'silicon-on-insulator' substrates in relation to temperature and the excitation-light wavelength are presented. A substantial increase in island-related PL intensity is observed for structures with Ge(Si) islands grown on silicon substrates upon an increase in temperature from 4 to 70 K. This increase is due to the diffusion of nonequilibrium carriers from the silicon substrate into the active layer with the islands. In this case, a slow component with a characteristic time of {approx}100 ns appears in the PL rise kinetics. At the same time, no slow component in the PL rise kinetics and no rise in the PL intensity with increasing temperature are observed for structures grown on 'silicon-on-insulator' substrates, in which the active layer with the islands is insulated from the silicon substrate. It is found that absorption of the excitation light in the islands and SiGe wetting layers mainly contributes to the excitation of the PL signal from the islands under sub-bandgap optical pump conditions.

  15. Evaluate Si Layers: Cooperative Research and Development Final Report, CRADA Number CRD-07-255

    SciTech Connect (OSTI)

    Teplin, C.

    2013-04-01T23:59:59.000Z

    Evaluate Si layers based on heteroepitaxial Si growth on RABITS textured metal substrates coated with textured buffer layers.

  16. Double-dot charge transport in Si single-electronhole transistors L. P. Rokhinson,a)

    E-Print Network [OSTI]

    Rokhinson, Leonid

    ­oxide­ semiconductor field-effect transistors MOSFETs brought to light several issues related to the electrical beneath the dot transforming it into a free-standing bridge. Subsequently, 40 or 50 nm of oxide are thermally grown which further reduce the size of the dot. Polysilicon gate is deposited over the bridge

  17. Study of transport properties in graphene monolayer flakes on SiO[sub 2] substrates

    E-Print Network [OSTI]

    Tirado, J. M.

    We investigate the carrier mobility in monolayer and bilayer graphene with a top HfO2dielectric, as a function of the HfO2film thickness and temperature. The results show that the carrier mobility decreases during the ...

  18. Prediction of Thermal Conductivity for Irradiated SiC/SiC Composites by Informing Continuum Models with Molecular Dynamics Data

    SciTech Connect (OSTI)

    Nguyen, Ba Nghiep; Gao, Fei; Henager, Charles H.; Kurtz, Richard J.

    2014-05-01T23:59:59.000Z

    This article proposes a new method to estimate the thermal conductivity of SiC/SiC composites subjected to neutron irradiation. The modeling method bridges different scales from the atomic scale to the scale of a 2D SiC/SiC composite. First, it studies the irradiation-induced point defects in perfect crystalline SiC using molecular dynamics (MD) simulations to compute the defect thermal resistance as a function of vacancy concentration and irradiation dose. The concept of defect thermal resistance is explored explicitly in the MD data using vacancy concentrations and thermal conductivity decrements due to phonon scattering. Point defect-induced swelling for chemical vapor deposited (CVD) SiC as a function of irradiation dose is approximated by scaling the corresponding MD results for perfect crystal ?-SiC to experimental data for CVD-SiC at various temperatures. The computed thermal defect resistance, thermal conductivity as a function of grain size, and definition of defect thermal resistance are used to compute the thermal conductivities of CVD-SiC, isothermal chemical vapor infiltrated (ICVI) SiC and nearly-stoichiometric SiC fibers. The computed fiber and ICVI-SiC matrix thermal conductivities are then used as input for an Eshelby-Mori-Tanaka approach to compute the thermal conductivities of 2D SiC/SiC composites subjected to neutron irradiation within the same irradiation doses. Predicted thermal conductivities for an irradiated Tyranno-SA/ICVI-SiC composite are found to be comparable to available experimental data for a similar composite ICVI-processed with these fibers.

  19. Selective, deep Si trench etching with dimensional control

    SciTech Connect (OSTI)

    Shul, R.J.; Willison, C.G.; Zhang, L.

    1998-08-01T23:59:59.000Z

    The recent development of a high-aspect ratio Si etch (HARSE) process has enabled the fabrication of a variety of Si structures where deep trench etching is necessary. The HARSE process relies on the formation of a sidewall etch inhibitor to prevent lateral etching of the Si structures during exposure to an aggressive SF{sub 6}/Ar plasma etch chemistry. The process yields highly anisotropic profiles with excellent dimensional control for high aspect ratio features. In this study, Si etch rates and etch selectivities to photoresist are reported as a function of chamber pressure, cathode rf-power, ICP source power, and gas flow. Si etch rates > 3 {micro}m/min with etch selectivities to resist > 75:1 were obtained. Lateral dimensional control, etch selectivities to SiO{sub 2} and Si{sub 3}N{sub 4}, and aspect ratio dependent etching (ARDE) will also be discussed.

  20. Strain and stability of ultrathin Ge layers in Si/Ge/Si axial heterojunction nanowires

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

    Ross, Frances M.; Stach, Eric A.; Wen, Cheng -Yen; Reuter, Mark C.; Su, Dong

    2015-03-11T23:59:59.000Z

    The abrupt heterointerfaces in the Si/Ge materials system presents useful possibilities for electronic device engineering because the band structure can be affected by strain induced by the lattice mismatch. In planar layers, heterointerfaces with abrupt composition changes are difficult to realize without introducing misfit dislocations. However, in catalytically grown nanowires, abrupt heterointerfaces can be fabricated by appropriate choice of the catalyst. Here we grow nanowires containing Si/Ge and Si/Ge/Si structures respectively with sub-1nm thick Ge "quantum wells" and we measure the interfacial strain fields using geometric phase analysis. Narrow Ge layers show radial strains of several percent, with a correspondingmore »dilation in the axial direction. Si/Ge interfaces show lattice rotation and curvature of the lattice planes. We conclude that high strains can be achieved, compared to what is possible in planar layers. In addition, we study the stability of these heterostructures under heating and electron beam irradiation. The strain and composition gradients are supposed to the cause of the instability for interdiffusion.« less

  1. TRANSPORT...18 SHOPPING...22

    E-Print Network [OSTI]

    Brierley, Andrew

    of renewable energy sources, paying attention to the environmental impact of our activities, and setting, while changes are made here on the ground through campaigns around transport, food and ethical targets for the reduction of energy consumption, and the attainment of carbon neutrality. I am delighted

  2. Storing and transporting energy

    DOE Patents [OSTI]

    McClaine, Andrew W. (Lexington, MA); Brown, Kenneth (Reading, MA)

    2010-09-07T23:59:59.000Z

    Among other things, hydrogen is released from water at a first location using energy from a first energy source; the released hydrogen is stored in a metal hydride slurry; and the metal hydride slurry is transported to a second location remote from the first location.

  3. Policy Research TRANSPORTATION

    E-Print Network [OSTI]

    to attract businesses and jobs to Texas, as the state has become increasingly dependent on the efficient will continue to be an important part of the 21st century transportation model, more efficient use of available and innovation; and · Serve as an independent resource to the Texas Legislature, providing analyses of the state

  4. Artificial oxygen transport protein

    DOE Patents [OSTI]

    Dutton, P. Leslie

    2014-09-30T23:59:59.000Z

    This invention provides heme-containing peptides capable of binding molecular oxygen at room temperature. These compounds may be useful in the absorption of molecular oxygen from molecular oxygen-containing atmospheres. Also included in the invention are methods for treating an oxygen transport deficiency in a mammal.

  5. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect (OSTI)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2003-01-30T23:59:59.000Z

    This is the second quarterly progress report for Year-4 of the ACTS Project. It includes a review of progress made in: (1) Flow Loop construction and development and (2) research tasks during the period of time between October 1, 2002 and December 30, 2002. This report presents a review of progress on the following specific tasks. (a) Design and development of an Advanced Cuttings Transport Facility Task 3: Addition of a Cuttings Injection/Separation System, Task 4: Addition of a Pipe Rotation System. (b) New research project (Task 9b): ''Development of a Foam Generator/Viscometer for Elevated Pressure and Elevated Temperature (EPET) Conditions''. (d) Research project (Task 10): ''Study of Cuttings Transport with Aerated Mud Under Elevated Pressure and Temperature Conditions''. (e) Research on three instrumentation tasks to measure: Cuttings concentration and distribution in a flowing slurry (Task 11), Foam texture while transporting cuttings. (Task 12), and Viscosity of Foam under EPET (Task 9b). (f) New Research project (Task 13): ''Study of Cuttings Transport with Foam under Elevated Pressure and Temperature Conditions''. (g) Development of a Safety program for the ACTS Flow Loop. Progress on a comprehensive safety review of all flow-loop components and operational procedures. (Task 1S). (h) Activities towards technology transfer and developing contacts with Petroleum and service company members, and increasing the number of JIP members.

  6. Parking & Transportation Services Sustainability &

    E-Print Network [OSTI]

    Minnesota, University of

    responsibility. Embracing the policies of the larger university, Parking and Transportation Services has institution, to take a leadership role in encouraging environmental responsibility on a statewide level Development at the U of M ­ for purchasing practices from diverse suppliers · 2010 Transit System of the Year

  7. 21st Annual Transportation

    E-Print Network [OSTI]

    Minnesota, University of

    would cost more than $40 billion over next 20 years ·! If used alone, state gas tax would need more than Investment Plan ·! Mn/DOT Statewide Transportation Plan #12;MHSIS goals ·! Develop a long range vision expansions ·!Fiscally-constrained approach #12;New investment strategy ·! Realistic ·! Innovative ·! Focuses

  8. Saturated Zone Colloid Transport

    SciTech Connect (OSTI)

    H. S. Viswanathan

    2004-10-07T23:59:59.000Z

    This scientific analysis provides retardation factors for colloids transporting in the saturated zone (SZ) and the unsaturated zone (UZ). These retardation factors represent the reversible chemical and physical filtration of colloids in the SZ. The value of the colloid retardation factor, R{sub col} is dependent on several factors, such as colloid size, colloid type, and geochemical conditions (e.g., pH, Eh, and ionic strength). These factors are folded into the distributions of R{sub col} that have been developed from field and experimental data collected under varying geochemical conditions with different colloid types and sizes. Attachment rate constants, k{sub att}, and detachment rate constants, k{sub det}, of colloids to the fracture surface have been measured for the fractured volcanics, and separate R{sub col} uncertainty distributions have been developed for attachment and detachment to clastic material and mineral grains in the alluvium. Radionuclides such as plutonium and americium sorb mostly (90 to 99 percent) irreversibly to colloids (BSC 2004 [DIRS 170025], Section 6.3.3.2). The colloid retardation factors developed in this analysis are needed to simulate the transport of radionuclides that are irreversibly sorbed onto colloids; this transport is discussed in the model report ''Site-Scale Saturated Zone Transport'' (BSC 2004 [DIRS 170036]). Although it is not exclusive to any particular radionuclide release scenario, this scientific analysis especially addresses those scenarios pertaining to evidence from waste-degradation experiments, which indicate that plutonium and americium may be irreversibly attached to colloids for the time scales of interest. A section of this report will also discuss the validity of using microspheres as analogs to colloids in some of the lab and field experiments used to obtain the colloid retardation factors. In addition, a small fraction of colloids travels with the groundwater without any significant retardation. Radionuclides irreversibly sorbed onto this fraction of colloids also transport without retardation. The transport times for these radionuclides will be the same as those for nonsorbing radionuclides. The fraction of nonretarding colloids developed in this analysis report is used in the abstraction of SZ and UZ transport models in support of the total system performance assessment (TSPA) for the license application (LA). This analysis report uses input from two Yucca Mountain Project (YMP) analysis reports. This analysis uses the assumption from ''Waste Form and In-Drift Colloids-Associated Radionuclide Concentrations: Abstraction and Summary'' that plutonium and americium are irreversibly sorbed to colloids generated by the waste degradation processes (BSC 2004 [DIRS 170025]). In addition, interpretations from RELAP analyses from ''Saturated Zone In-Situ Testing'' (BSC 2004 [DIRS 170010]) are used to develop the retardation factor distributions in this analysis.

  9. MODEL-BASED FEEDBACK CONTROL FOR AN AUTOMATED TRANSFER OUT OF SI OPERATION DURING SI TO HCCI TRANSITIONS IN GASOLINE ENGINES

    E-Print Network [OSTI]

    Stefanopoulou, Anna

    MODEL-BASED FEEDBACK CONTROL FOR AN AUTOMATED TRANSFER OUT OF SI OPERATION DURING SI TO HCCI for the transition between spark ignition (SI) and homo- geneous charge compression ignition (HCCI) combustion modes by approaching the transfer out of SI operation during the SI into HCCI transition in a closed-loop control

  10. Comparison of Graphene Formation on C-face and Si-face SiC {0001} Surfaces Luxmi, N. Srivastava, Guowei He, and R. M. Feenstra

    E-Print Network [OSTI]

    Feenstra, Randall

    1 Comparison of Graphene Formation on C-face and Si-face SiC {0001} Surfaces Luxmi, N. Srivastava of graphene formed on the ( 1000 ) surface (the C-face) and the (0001) surface (the Si-face) of Si) and low-energy electron microscopy (LEEM). The graphene forms due to preferential sublimation of Si from

  11. High Cooling Power Density of SiGe/Si Superlattice Microcoolers Gehong Zeng, Xiaofeng Fan, Chris LaBounty, John E. Bowers, Edward Croke1

    E-Print Network [OSTI]

    High Cooling Power Density of SiGe/Si Superlattice Microcoolers Gehong Zeng, Xiaofeng Fan, Chris La, University of California, Santa Cruz, CA 95064 ABSTRACT Fabrication and characterization of SiGe for their potential monolithic integration with Si microelectronics. SiGe is a good thermoelectric material especially

  12. Nanopatterning of Si/SiGe Two-dimensional Hole Gases by PFOTS-aided AFM Lithography of Carrier Supply Layer

    E-Print Network [OSTI]

    Nanopatterning of Si/SiGe Two-dimensional Hole Gases by PFOTS-aided AFM Lithography of Carrier The nanopatterning of Si/SiGe layers by PFOTS (perfluorooctyl trichlorosilane) -aided AFM (atomic force microscopy and then transfer patterns in to underlying SiGe layers by a two-step selective wet etching. Minimum linewidths

  13. III International Conference on SiGe(C) Epitaxy and Heterostructures, NM, Mar. 2003 SiGe Single-Hole Transistor Fabricated by AFM Oxidation and Epitaxial Regrowth

    E-Print Network [OSTI]

    III International Conference on SiGe(C) Epitaxy and Heterostructures, NM, Mar. 2003 110 SiGe Single, West Lafayette, IN 47907, U.S.A. Nanodevices on Si/SiGe heterostructures are of growing interest [1 the performance of the devices. In this paper, we demonstrate a reproducible single-hole transistor SiGe device

  14. Institute of Transport Studies PSU Transportation Seminar, 21 May 2010

    E-Print Network [OSTI]

    Bertini, Robert L.

    comparison · Market size and segments · Emerging issues · Conclusions #12;3 Institute of Transport Studies profession #12;4 Institute of Transport Studies E-Bike Fundamentals · E-bike physics 101 ­ Kinetic energy ­ Power required for movement #12;5 Institute of Transport Studies Kinetic energy · Kinetic energy

  15. 35 Alternative Transportation Fuels in California ALTERNATIVE TRANSPORTATION

    E-Print Network [OSTI]

    35 Alternative Transportation Fuels in California Chapter 4 ALTERNATIVE TRANSPORTATION FUELS IN CALIFORNIA INTRODUCTION The introduction of alternative fuels into California's transportation market has supply at low prices. But, with an uncertain long-term future for oil supplies and prices, alternative

  16. Phase separation in SiGe nanocrystals embedded in SiO{sub 2} matrix during high temperature annealing

    SciTech Connect (OSTI)

    Mogaddam, N. A. P.; Turan, R. [Department of Physics, Middle East Technical University, 06531 Ankara (Turkey); Alagoz, A. S. [Department of Physics, Middle East Technical University, 06531 Ankara (Turkey); Department of Applied Science, University of Arkansas at Little Rock, Little Rock, Arkansas 72204 (United States); Yerci, S. [Department of Physics, Middle East Technical University, 06531 Ankara (Turkey); Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215 (United States); Foss, S.; Finstad, T. G. [Department of Physics, University of Oslo, Oslo 0316 (Norway)

    2008-12-15T23:59:59.000Z

    SiGe nanocrystals have been formed in SiO{sub 2} matrix by cosputtering Si, Ge, and SiO{sub 2} independently on Si substrate. Effects of the annealing time and temperature on structural and compositional properties are studied by transmission electron microscopy, x-ray diffraction (XRD), and Raman spectroscopy measurements. It is observed that Ge-rich Si{sub (1-x)}Ge{sub x} nanocrystals do not hold their compositional uniformity when annealed at high temperatures for enough long time. A segregation process leading to separation of Ge and Si atoms from each other takes place. This process has been evidenced by a double peak formation in the XRD and Raman spectra. We attributed this phase separation to the differences in atomic size, surface energy, and surface diffusion disparity between Si and Ge atoms leading to the formation of nonhomogenous structure consist of a Si-rich SiGe core covered by a Ge-rich SiGe shell. This experimental observation is consistent with the result of reported theoretical and simulation methods.

  17. We're All Transportation Planners

    E-Print Network [OSTI]

    Curry, Melanie

    2006-01-01T23:59:59.000Z

    of facts that global warming is real, that transportationCalifornia Transportation Center, with help is a majorresearch on compelling transportation can both reduce the

  18. Essays on Transportation Safety, Economics, and Policy

    E-Print Network [OSTI]

    Scholl, Patricia Lynn

    2011-01-01T23:59:59.000Z

    2002. TCF, 2000, “Widening the Transportation Divide: HowGovernor Davis’ Transportation Plan Leaves Transit-People Stranded”, Transportation Choices Forum, 2000.

  19. In situ toughened SiC ceramics with Al-B-C additions and oxide-coated SiC platelet/SiC composites

    SciTech Connect (OSTI)

    Cao, J. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering; [Lawrence Berkeley National Lab., CA (United States). Materials Sciences Div.

    1996-12-01T23:59:59.000Z

    This work aimed at fabrication and characterization of high toughness SiC ceramics through the applications of in situ toughening and SiC platelet reinforcement. The processing-microstructure-property relations of hot pressed SiC with Al, B, and C additions (designated as ABC-SiC) were investigated. Through a liquid phase sintering mechanism, dense SiC was obtained by hot pressing at a temperature as low as 1,700 C with 3 wt% Al, 0.6 wt% B, and 2 wt% C additions. These sintering aids also enhanced the {beta}-to-{alpha} (3C-to-4H) phase transformation, which promoted SiC grains to grow into plate-like shapes. Under optimal processing conditions, the microstructure exhibited high-aspect-ratio plate-shaped grains with a thin (< 1 nm) Al-containing amorphous grain boundary film. The mechanical properties of the toughened SiC and the composites were evaluated in comparison with a commercial Hexoloy SiC under identical test conditions. The C-curve behavior was examined using the strength-indentation load relationship and compared with that directly measured using precracked compact tension specimens. The in situ toughened ABC-SiC exhibited much improved flaw tolerance and a significantly rising R-curve behavior. A steady-state toughness in excess of 9 MPam{sup 1/2} was recorded for the ABC-SiC in comparison to a single valued toughness below 3 MPam{sup 1/2} for the Hexoloy. Toughening in the ABC-SiC was mainly attributed to grain bridging and subsequent pullout of the plate-shaped grains. The high toughness ABC-SiC exhibited a bend strength of 650 MPa with a Weibull modulus of 19; in comparison, the commercial SiC showed a bend strength of 400 MPa with a Weibull modulus of 6. Higher fracture toughness was also achieved by the reinforcement of SiC platelets, encapsulated with alumina, yttria, or silica, in a SiC matrix.

  20. Integrated transportation system design optimization

    E-Print Network [OSTI]

    Taylor, Christine P. (Christine Pia), 1979-

    2007-01-01T23:59:59.000Z

    Traditionally, the design of a transportation system has focused on either the vehicle design or the network flow, assuming the other as given. However, to define a system level architecture for a transportation system, ...

  1. Transforming California's Freight Transport System

    E-Print Network [OSTI]

    California at Davis, University of

    Transforming California's Freight Transport System Policy Forum on the Role of Freight Transport Standard #12;2050 Vision- Key Conceptual Outcomes Technology Transformation Early Action Cleaner Combustion Multiple Strategies Federal Action Efficiency Gains Energy Transformation 9 #12;Further reduce localized

  2. Sandia National Laboratories: Transportation Safety

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

    Experimental Testing Phenomenological Modeling Risk and Safety Assessment Cyber-Based Vulnerability Assessments Uncertainty Analysis Transportation Safety Fire Science Human...

  3. Transporting export coal from Appalachia

    SciTech Connect (OSTI)

    Not Available

    1982-11-01T23:59:59.000Z

    This publication is part of a series titled Market Guide for Steam Coal Exports from Appalachia. It focuses on the transportation link in the steam-coal supply chain, enabling producers to further assess their transportation options and their ability to compete in the export-coal marketplace. Transportation alternatives and handling procedures are discussed, and information is provided on the costs associated with each element in the transportation network.

  4. Thermal Conductivity of SiC/Si Composites – Porting PNNL EMTA Code for Fusion Analyses

    SciTech Connect (OSTI)

    Henager, Charles H.; Nguyen, Ba Nghiep

    2013-04-19T23:59:59.000Z

    An existing modeling method, the EMTA (Eshelby-Mori-Tanaka approach) modeling approach [1], is applied to the study of SiC/SiC 2D woven composites for fusion reactor applications for the first time, to the best of our knowledge, with excellent results. We compare EMTA model results to existing thermal conductivity data for these materials and suggest that in the future this approach can be beneficial by providing us with tools to further optimize these composite materials for fusion energy applications since the EMTA method and code can address both thermal and mechanical properties with the same framework.

  5. Compositional evolution of SiGe islands on patterned Si (001) substrates

    SciTech Connect (OSTI)

    Zhang Jianjun [Institute of Semiconductor and Solid State Physics, University Linz, A-4040 Linz (Austria); Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany); Rastelli, Armando; Schmidt, Oliver G. [Institute for Integrative Nanosciences, IFW Dresden, Helmholtzstr. 20, D-01069 Dresden (Germany); Bauer, Guenther [Institute of Semiconductor and Solid State Physics, University Linz, A-4040 Linz (Austria)

    2010-11-15T23:59:59.000Z

    The authors investigate, by atomic-force-microscopy-based nanotomography, the composition evolution of ordered SiGe islands grown on pit-patterned Si (001) substrates as their size and aspect ratio increase with increasing Ge deposition. Compared to islands grown on flat substrates, the ordered island arrays show improved size, shape, and compositional homogeneity. The three-dimensional composition profiles of individual pyramids, domes, and barns reveal that the Ge fraction at the base and in subsurface regions of the islands decreases with increasing amount of deposited Ge.

  6. Integrated Transportation System Design Optimization

    E-Print Network [OSTI]

    Integrated Transportation System Design Optimization by Christine Taylor B.S. Cornell University by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Professor Jaime Peraire Chairman, Department Graduate Committee #12;2 #12;Integrated Transportation System Abstract Traditionally, the design of a transportation system has focused on either the vehicle design

  7. Council of University Transportation Centers

    E-Print Network [OSTI]

    Nagurney, Anna

    Council of University Transportation Centers 13th Anniversary CUTC Awards Banquet January 9, 2010 Omni Shoreham Hotel Washington, D.C. #12;Council of University Transportation Centers 13th Anniversary Awards Banquet Saturday, January 9, 2010 Welcome Stephen Albert, CUTCVice-President WesternTransportation

  8. Transportation Center Seminar........ Patrice Marcotte

    E-Print Network [OSTI]

    Bustamante, Fabián E.

    Transportation Center Seminar........ Patrice Marcotte Professor and Acting Director Computer on a Transportation Network With Rigid Capacities" Abstract: Static network equilibrium is a well transportation network, taking into account that users behave selfishly, i.e., only travel on shortest paths

  9. Fuel cell water transport

    DOE Patents [OSTI]

    Vanderborgh, Nicholas E. (Los Alamos, NM); Hedstrom, James C. (Los Alamos, NM)

    1990-01-01T23:59:59.000Z

    The moisture content and temperature of hydrogen and oxygen gases is regulated throughout traverse of the gases in a fuel cell incorporating a solid polymer membrane. At least one of the gases traverses a first flow field adjacent the solid polymer membrane, where chemical reactions occur to generate an electrical current. A second flow field is located sequential with the first flow field and incorporates a membrane for effective water transport. A control fluid is then circulated adjacent the second membrane on the face opposite the fuel cell gas wherein moisture is either transported from the control fluid to humidify a fuel gas, e.g., hydrogen, or to the control fluid to prevent excess water buildup in the oxidizer gas, e.g., oxygen. Evaporation of water into the control gas and the control gas temperature act to control the fuel cell gas temperatures throughout the traverse of the fuel cell by the gases.

  10. Parallel Transports in Webs

    E-Print Network [OSTI]

    Christian Fleischhack

    2003-07-17T23:59:59.000Z

    For connected reductive linear algebraic structure groups it is proven that every web is holonomically isolated. The possible tuples of parallel transports in a web form a Lie subgroup of the corresponding power of the structure group. This Lie subgroup is explicitly calculated and turns out to be independent of the chosen local trivializations. Moreover, explicit necessary and sufficient criteria for the holonomical independence of webs are derived. The results above can even be sharpened: Given an arbitrary neighbourhood of the base points of a web, then this neighbourhood contains some segments of the web whose parameter intervals coincide, but do not include 0 (that corresponds to the base points of the web), and whose parallel transports already form the same Lie subgroup as those of the full web do.

  11. Direct growth of few-layer graphene on 6H-SiC and 3C-SiC/Si via propane chemical vapor deposition

    SciTech Connect (OSTI)

    Michon, A.; Vezian, S.; Portail, M. [CNRS-CRHEA, Rue Bernard Gregory, 06560 Valbonne (France); Ouerghi, A. [CNRS-LPN, Route de Nozay, 91460 Marcoussis (France); Zielinski, M.; Chassagne, T. [NOVASiC, Savoie Technolac, Arche Bat 4, BP267, 73375 Le Bourget du Lac (France)

    2010-10-25T23:59:59.000Z

    We propose to grow graphene on SiC by a direct carbon feeding through propane flow in a chemical vapor deposition reactor. X-ray photoemission and low energy electron diffraction show that propane allows to grow few-layer graphene (FLG) on 6H-SiC(0001). Surprisingly, FLG grown on (0001) face presents a rotational disorder similar to that observed for FLG obtained by annealing on (000-1) face. Thanks to a reduced growth temperature with respect to the classical SiC annealing method, we have also grown FLG/3C-SiC/Si(111) in a single growth sequence. This opens the way for large-scale production of graphene-based devices on silicon substrate.

  12. Isoscalar giant resonance strength in Si-28

    E-Print Network [OSTI]

    Youngblood, David H.; Lui, Y. -W; Clark, H. L.

    2007-01-01T23:59:59.000Z

    PHYSICAL REVIEW C 76, 027304 (2007) Isoscalar giant resonance strength in 28Si D. H. Youngblood, Y.-W. Lui, and H. L. Clark Cyclotron Institute, Texas A&M University, College Station, Texas 77843, USA (Received 7 May 2007; published 28 August... that somewhat mimic an E1 angular distribution. This work was supported in part by the U.S. Department of Energy under grant No. DE-FG03-93ER40773 and by The Robert A. Welch Foundation under grant No. A-0558. [1] D. H. Youngblood, Y.-W. Lui, and H. L. Clark...

  13. Phonon-assisted transient electroluminescence in Si

    SciTech Connect (OSTI)

    Cheng, Tzu-Huan, E-mail: f94943139@ntu.edu.tw [Graduate Institute of Photonics and Optoelectronics, National Taiwan University, Taipei, Taiwan (China); Chu-Su, Yu [Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan and Department of Laboratory Medicine, National Taiwan University Hospital, Taipei, Taiwan (China); Liu, Chien-Sheng [Institute of Biomedical Engineering, National Taiwan University, Taipei, Taiwan (China); Lin, Chii-Wann [Institute of Biomedical Engineering and Institute of Electrical Engineering, National Taiwan University, Taipei, Taiwan (China)

    2014-06-30T23:59:59.000Z

    The phonon-replica infrared emission is observed at room temperature from indirect band gap Si light-emitting diode under forward bias. With increasing injection current density, the broadened electroluminescence spectrum and band gap reduction are observed due to joule heating. The spectral-resolved temporal response of electroluminescence reveals the competitiveness between single (TO) and dual (TO?+?TA) phonon-assisted indirect band gap transitions. As compared to infrared emission with TO phonon-replica, the retarder of radiative recombination at long wavelength region (?1.2??m) indicates lower transition probability of dual phonon-replica before thermal equivalent.

  14. Do Si stars undergo any magnetic braking?

    E-Print Network [OSTI]

    P. North

    1998-02-23T23:59:59.000Z

    The old question of rotational braking of Ap Si stars is revisited on the empirical side, taking advantage of the recent Hipparcos results. Field stars with various evolutionary states are considered, and it is shown that the loose correlation between their rotational period and their surface gravity is entirely compatible with conservation of angular momentum. No evidence is found for any loss of angular momentum on the Main Sequence, which confirms earlier results based on less reliable estimates of surface gravity. The importance of reliable, fundamental Teff determinations of Bp and Ap stars is emphasized.

  15. Si Brilliant Technology Ltd | 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 IRaghuraji Agro Industries Pvt LtdShawangunk, New York: EnergySumoncleShidaMinnesota:Shreveport,ShrubShyamSi

  16. A=17Si (1993TI07)

    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(ANL-IN-03-032) -Less2012KE01)93TI07) (Not observed) See (1983ANZQ, 1988WA18,Si

  17. Si Pro AS | 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 being directedAnnualProperty Edit with form HistoryRistma AGShandongShirke Biofuels JumpSi Pro AS Jump to:

  18. Rail transportation update

    SciTech Connect (OSTI)

    Buchsbaum, L.

    2009-01-15T23:59:59.000Z

    Record western coal shipments and lucrative export traffic lead America's railroad to their fourth most profitable year in history. But with the coal boom going bust, higher rates, and a new administration and congress, what sort of transportation year can coal mines and shippers expect in 2009? The article gives the opinions of company executives and discusses findings of the recent so-called Christenson Report which investigated growing railroad market power. 1 ref., 1 fig.

  19. Multiscale thermal transport.

    SciTech Connect (OSTI)

    Graham, Samuel Jr. (; .); Wong, C. C.; Piekos, Edward Stanley

    2004-02-01T23:59:59.000Z

    A concurrent computational and experimental investigation of thermal transport is performed with the goal of improving understanding of, and predictive capability for, thermal transport in microdevices. The computational component involves Monte Carlo simulation of phonon transport. In these simulations, all acoustic modes are included and their properties are drawn from a realistic dispersion relation. Phonon-phonon and phonon-boundary scattering events are treated independently. A new set of phonon-phonon scattering coefficients are proposed that reflect the elimination of assumptions present in earlier analytical work from the simulation. The experimental component involves steady-state measurement of thermal conductivity on silicon films as thin as 340nm at a range of temperatures. Agreement between the experiment and simulation on single-crystal silicon thin films is excellent, Agreement for polycrystalline films is promising, but significant work remains to be done before predictions can be made confidently. Knowledge gained from these efforts was used to construct improved semiclassical models with the goal of representing microscale effects in existing macroscale codes in a computationally efficient manner.

  20. Transportation of medical isotopes

    SciTech Connect (OSTI)

    Nielsen, D.L.

    1997-11-19T23:59:59.000Z

    A Draft Technical Information Document (HNF-1855) is being prepared to evaluate proposed interim tritium and medical isotope production at the Fast Flux Test Facility (FFTF). This assessment examines the potential health and safety impacts of transportation operations associated with the production of medical isotopes. Incident-free and accidental impacts are assessed using bounding source terms for the shipment of nonradiological target materials to the Hanford Site, the shipment of irradiated targets from the FFTF to the 325 Building, and the shipment of medical isotope products from the 325 Building to medical distributors. The health and safety consequences to workers and the public from the incident-free transportation of targets and isotope products would be within acceptable levels. For transportation accidents, risks to works and the public also would be within acceptable levels. This assessment is based on best information available at this time. As the medical isotope program matures, this analysis will be revised, if necessary, to support development of a final revision to the Technical Information Document.

  1. Surety applications in transportation

    SciTech Connect (OSTI)

    Matalucci, R.V.; Miyoshi, D.S.

    1998-01-01T23:59:59.000Z

    Infrastructure surety can make a valuable contribution to the transportation engineering industry. The lessons learned at Sandia National Laboratories in developing surety principles and technologies for the nuclear weapons complex and the nuclear power industry hold direct applications to the safety, security, and reliability of the critical infrastructure. This presentation introduces the concepts of infrastructure surety, including identification of the normal, abnormal, and malevolent threats to the transportation infrastructure. National problems are identified and examples of failures and successes in response to environmental loads and other structural and systemic vulnerabilities are presented. The infrastructure surety principles developed at Sandia National Laboratories are described. Currently available technologies including (a) three-dimensional computer-assisted drawing packages interactively combined with virtual reality systems, (b) the complex calculational and computational modeling and code-coupling capabilities associated with the new generation of supercomputers, and (c) risk-management methodologies with application to solving the national problems associated with threats to the critical transportation infrastructure are discussed.

  2. Thermomechanical Performance of Si-Ti-C-O and Sintered SiC Fiber-Bonded Ceramics at High Temperatures

    SciTech Connect (OSTI)

    Matsunaga, Tadashi [ORNL; Lin, Hua-Tay [ORNL; Singh, Mrityunjay [NASA-Glenn Research Center, Cleveland; Kajii, Shinji [Ube Industries, Ltd.; Matsunaga, Kenji [Ube Industries, Ltd.; Ishikawa, Toshihiro [Ube Industries, Ltd.

    2011-01-01T23:59:59.000Z

    The stress-temperature-lifetime response of Si-Ti-C-O fiber-bonded ceramic (Tyrannohex ) and sintered SiC fiber-bonded ceramic (SA-Tyrannohex ) materials were investigated in air from 500 to 1150 C and 500 to 1400 C, respectively. The apparent threshold stress of Si-Ti-C-O fiber-bonded ceramic was about 175 MPa in the 500-1150 C temperature range. When the applied stress of the sintered SiC fiber-bonded ceramic was below an apparent threshold stress (e.g., ~225MPa) for tests conducted 1150 C, no failures were observed for lifetimes up to 1000h. In the case of sintered SiC fiber-bonded ceramic, at the temperature of 1300 C, the apparent threshold stress decreased to 175 MPa. The decrease in strength seemed to be caused by grain growth which was confirmed from the SEM fractography. Both fiber-bonded ceramics exhibited much higher durability than a commercial SiC/SiC composite at temperatures above 500 C. In addition, results suggested that the sintered SiC fiber-bonded ceramic (SA-Tyrannohex) is more stable than a Hi-Nicalon/MI SiC composite with BN/SiC fiber coating at temperatures above 1300 C.

  3. First-principles study of the Pd–Si system and Pd(001)/SiC(001) hetero-structure

    SciTech Connect (OSTI)

    Turchi, P.E.A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Ivashchenko, V.I. [National Academy of Sciences of Ukraine (NASU), Kiev (Ukraine)

    2014-11-01T23:59:59.000Z

    First-principles molecular dynamics simulations of the Pd(001)/3C–SiC(001) nano-layered structure were carried out at different temperatures ranging from 300 to 2100 K. Various PdSi (Pnma, Fm3m, P6m2, Pm3m), Pd2Si (P6?2m, P63/mmc, P3m1, P3?1m) and Pd3Si (Pnma, P6322, Pm3m, I4/mmm) structures under pressure were studied to identify the structure of the Pd/Si and Pd/C interfaces in the Pd/SiC systems at high temperatures. It was found that a large atomic mixing at the Pd/Si interface occurred at 1500–1800 K, whereas the Pd/C interface remained sharp even at the highest temperature of 2100 K. At the Pd/C interface, voids and a graphite-like clustering were detected. Palladium and silicon atoms interact at the Pd/Si interface to mostly form C22-Pd2Si and D011-Pd3Si fragments, in agreement with experiment.

  4. PORTLAND STATE UNIVERSITY CENTER FOR TRANSPORTATION STUDIES

    E-Print Network [OSTI]

    Bertini, Robert L.

    PORTLAND STATE UNIVERSITY CENTER FOR TRANSPORTATION STUDIES DEPARTMENT OF CIVIL & ENVIRONMENTAL Transportation System Performance Report December 27, 2005 #12;2Second Annual Portland Metropolitan Region Transportation System Performance Report Portland State University Center for Transportation Studies 2005

  5. Transportation Analysis, Modeling, and Simulation (TAMS) Application

    E-Print Network [OSTI]

    Transportation Analysis, Modeling, and Simulation (TAMS) Application Center for Transportation Passenger Flows Supply Chain Efficiency Transportation: Energy Environment Safety Security Vehicle Technologies T he Center for Transportation Analysis (CTA) TAMS application is a web-based tool that supports

  6. cond-mat/991022815Oct1999 Coexistence of Weak Localization and a Metallic Phase in Si/SiGe Quantum Wells

    E-Print Network [OSTI]

    Ihn, Thomas

    cond-mat/991022815Oct1999 Coexistence of Weak Localization and a Metallic Phase in Si/SiGe Quantum, Switzerland (October 15, 1999) Magnetoresistivity measurements on p-type Si/SiGe quantum wells reveal in a variety of material systems, such as p-type2­5 and n-type6,7 GaAs heterostructures, Si/SiGe8,9 and AlAs10

  7. Microwave joining of SiC ceramics and composites

    SciTech Connect (OSTI)

    Ahmad, I.; Silberglitt, R.; Tian, Y.L. [FM Technologies, Inc., Fairfax, VA (United States); Katz, J.D. [Los Alamos National Lab., NM (United States)

    1997-04-01T23:59:59.000Z

    Potential applications of SiC include components for advanced turbine engines, tube assemblies for radiant burners and petrochemical processing and heat exchangers for high efficiency electric power generation systems. Reliable methods for joining SiC are required in order to cost-effectively fabricate components for these applications from commercially available shapes and sizes. This manuscript reports the results of microwave joining experiments performed using two different types of SiC materials. The first were on reaction bonded SiC, and produced joints with fracture toughness equal to or greater than that of the base material over an extended range of joining temperatures. The second were on continuous fiber-reinforced SiC/SiC composite materials, which were successfully joined with a commercial active brazing alloy, as well as by using a polymer precursor.

  8. Compatibility of SiC and SiC Composites with Molten Lead

    SciTech Connect (OSTI)

    H Tunison

    2006-03-07T23:59:59.000Z

    The choice of structural material candidates to contain Lead at 1000 C are limited in number. Silicon carbide composites comprise one choice of possible containment materials. Short term screening studies (120 hours) were undertaken to study the behavior of Silicon Carbide, Silicon Nitride, elemental Silicon and various Silicon Carbide fiber composites focusing mainly on melt infiltrated composites. Isothermal experiments at 1000 C utilized graphite fixtures to contain the Lead and material specimens under a low oxygen partial pressure environment. The corrosion weight loss values (grams/cm{sup 2} Hr) obtained for each of the pure materials showed SiC (monolithic CVD or Hexoloy) to have the best materials compatibility with Lead at this temperature. Increased weight loss values were observed for pure Silicon Nitride and elemental Silicon. For the SiC fiber composite samples those prepared using a SiC matrix material performed better than Si{sub 3}N{sub 4} as a matrix material. Composites prepared using a silicon melt infiltration process showed larger corrosion weight loss values due to the solubility of silicon in lead at these temperatures. When excess silicon was removed from these composite samples the corrosion performance for these material improved. These screening studies were used to guide future long term exposure (both isothermal and non-isothermal) experiments and Silicon Carbide composite fabrication work.

  9. Tribological Properties of Self-assembled Monolayers on Au, SiOx and Si Surfaces

    SciTech Connect (OSTI)

    KIM,HYUN I.; BOIADJIEV,V.; HOUSTON,JACK E.; ZHU,X.-Y; KIELY,J.D.

    2000-07-20T23:59:59.000Z

    Using interracial force microscopy (IFM), the tribological properties of self-assembled monolayer (SAM) on Si surfaces produced by a new chemical strategy are investigated and compared to those of classical SAM systems, which include alkanethiols on Au and alkylsilanes on SiO{sub x}. The new SAM films are prepared by depositing n-alkyl chains with OH-terminations onto Cl-terminated Si substrates. The chemical nature of the actual lubricating molecules, n-dodecyl, is kept constant in all three thin film systems for direct comparison and similarities and differences in tribological properties are observed. The adhesion strength is virtually identical for all three systems; however, frictional properties differ due to differences in film packing. Differences in the chemical bonds that attach the lubricant molecules to the substrate are also discussed as they influence variations in film wear and durability. It is demonstrated that the new SAM films are capable of controlling the friction and adhesion of Si surfaces as well as the classical SAMs in addition to providing a greater potential to be more reproducible and more durable.

  10. Asymmetric Relaxation of SiGe in Patterned Si Line Structures

    SciTech Connect (OSTI)

    Wormington, Matthew [Bede Scientific Inc., 14 Inverness Drive East, Suite H-100, Centennial, CO 80112 (United States); Lafford, Tamzin; Godny, Stephane; Ryan, Paul [Bede plc, Belmont Business Park, Durham, DH1 1TW (United Kingdom); Loo, Roger; Hikavyy, Andriy; Caymax, Matty [IMEC Kapeldreef 75, B 3001 Leuven (Belgium); Bhouri, Nada [IMEC Kapeldreef 75, B 3001 Leuven (Belgium); Institut National Polytechnique de Grenoble, 46, avenue Felix Viallet, Grenoble Cedex 1 (France)

    2007-09-26T23:59:59.000Z

    High resolution X-ray diffraction (HRXRD) measurements were performed using a commercially-available X-ray metrology tool, the BedeMetrix-L, on small test pads containing arrays of SiGe line structures selectively deposited in Si recesses with various window dimensions. Reciprocal space maps (RSMs) were performed in two orthogonal <110> directions in order to determine the lattice parameter parallel and perpendicular to the lines. With narrow lines, asymmetric relaxation effects were seen: the SiGe was fully strained along the long dimension of the lines while there was significant relaxation along the short dimension of the lines. The magnitude of the relaxation increased significantly for lines with short dimension below about 1 {mu}m. We show how to determine the lattice parameters, and hence the strain of the SiGe in the [110] and [-110] directions, the Ge composition and the relaxation initially using RSMs, but with an extension to measurements more suitable for in-fab metrology.

  11. Nanoparticle growth and transport mechanisms in capacitively coupled silane discharges: a numerical investigation

    SciTech Connect (OSTI)

    Bleecker, K. de; Bogaerts, A. [PLASMANT, Dept. of Chemistry, University of Antwerp (Ukraine), Universiteitsplein 1, 2610 Wilrijk (Belgium); Goedheer, W.J. [FOM Institute for Plasma Physics 'Rijnhuizen', Association EURATOM-FOM, Trilateral Euregio Cluster, P.O. Box 1207, 3430 BE Nieuwegein (Netherlands)

    2005-10-31T23:59:59.000Z

    A self-consistent 1D fluid model is used to investigate the formation, growth and transport mechanisms of sub-micrometer particles in a low pressure capacitively coupled radio-frequency silane (SiH4) discharge. In this contribution we analyze the competition between the different forces governing the transport of nanometer-sized particles and the specific role of the thermophoretic force arising from a thermal gradient in gas temperature induced by heating or cooling of the electrodes. Further growth of the nanoparticles due to coagulation is also described by coupling the 1D fluid model with an aerosol dynamics model.

  12. Low threshold InGaAsP terrace mass transport laser on semi-insulating substrate

    SciTech Connect (OSTI)

    Chen, T.R.; Chiu, L.C.; Yu, K.L.; Koren, U.; Hasson, A.; Margalit, S.; Yariv, A.

    1982-12-15T23:59:59.000Z

    Very low threshold InGaAsP terrace lasers on semi-insulating (SI) InP substrate have been fabricated using the mass transport technique. The fabrication process involves a single-step liquid phase epitaxial (LPE) growth followed by a mass transport of InP at approx.675 /sup 0/C in the presence of an InP cover wafer. Lasers operating in the fundamental transverse mode with smooth far-field patterns and threshold currents as low as 9.5 mA have been obtained.

  13. Evolution of the Oligopeptide Transporter (OPT) family

    E-Print Network [OSTI]

    Gomolplitinant, Kenny Matee

    2010-01-01T23:59:59.000Z

    Jr. 2007. The bile/arsenite/riboflavin transporter (BART)and 3) the Bile acid/Arsenite/Riboflavin Transporter (BART)

  14. Enhancing Transportation Energy Security through Advanced Combustion...

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

    Transportation Energy Security through Advanced Combustion and Fuels Technologies Enhancing Transportation Energy Security through Advanced Combustion and Fuels Technologies 2005...

  15. Transportation and Stationary Power Integration: Workshop Proceedings...

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

    Integration: Workshop Proceedings Transportation and Stationary Power Integration: Workshop Proceedings Proceedings for the Transportation and Stationary Power Integration Workshop...

  16. Enhancing Railroad Hazardous Materials Transportation Safety...

    Office of Environmental Management (EM)

    Enhancing Railroad Hazardous Materials Transportation Safety Rail Routing Enhancing Railroad Hazardous Materials Transportation Safety Rail Routing Presentation made by Kevin...

  17. Advanced Vehicle Electrification & Transportation Sector Electrificati...

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

    & Transportation Sector Electrification Advanced Vehicle Electrification & Transportation Sector Electrification 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies...

  18. Spring 2014 National Transportation Stakeholder Forum Meeting...

    Office of Environmental Management (EM)

    Spring 2014 National Transportation Stakeholder Forum Meeting, Minnesota Spring 2014 National Transportation Stakeholder Forum Meeting, Minnesota NTSF 2014 Meeting Agenda...

  19. PROCEEDINGS: Conference on Transportation in Developing Countries

    E-Print Network [OSTI]

    Cervero, Robert; Sperling, Daniel; Mason, Jonathan

    1998-01-01T23:59:59.000Z

    Environment, and Ecology Enhancing Mobility: Transportation Technologies, Operations, Design Non-Motorized Transportation: Mobility and Safety Economics, Financing,

  20. Steel-SiC Metal Matrix Composite Development

    SciTech Connect (OSTI)

    Smith, Don D.

    2005-07-17T23:59:59.000Z

    The goal of this project is to develop a method for fabricating SiC-reinforced high-strength steel. We are developing a metal-matrix composite (MMC) in which SiC fibers are be embedded within a metal matrix of steel, with adequate interfacial bonding to deliver the full benefit of the tensile strength of the SiC fibers in the composite.

  1. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect (OSTI)

    Stefan Miska; Troy Reed; Ergun Kuru

    2004-09-30T23:59:59.000Z

    The Advanced Cuttings Transport Study (ACTS) was a 5-year JIP project undertaken at the University of Tulsa (TU). The project was sponsored by the U.S. Department of Energy (DOE) and JIP member companies. The objectives of the project were: (1) to develop and construct a new research facility that would allow three-phase (gas, liquid and cuttings) flow experiments under ambient and EPET (elevated pressure and temperature) conditions, and at different angle of inclinations and drill pipe rotation speeds; (2) to conduct experiments and develop a data base for the industry and academia; and (3) to develop mechanistic models for optimization of drilling hydraulics and cuttings transport. This project consisted of research studies, flow loop construction and instrumentation development. Following a one-year period for basic flow loop construction, a proposal was submitted by TU to the DOE for a five-year project that was organized in such a manner as to provide a logical progression of research experiments as well as additions to the basic flow loop. The flow loop additions and improvements included: (1) elevated temperature capability; (2) two-phase (gas and liquid, foam etc.) capability; (3) cuttings injection and removal system; (4) drill pipe rotation system; and (5) drilling section elevation system. In parallel with the flow loop construction, hydraulics and cuttings transport studies were preformed using drilling foams and aerated muds. In addition, hydraulics and rheology of synthetic drilling fluids were investigated. The studies were performed under ambient and EPET conditions. The effects of temperature and pressure on the hydraulics and cuttings transport were investigated. Mechanistic models were developed to predict frictional pressure loss and cuttings transport in horizontal and near-horizontal configurations. Model predictions were compared with the measured data. Predominantly, model predictions show satisfactory agreements with the measured data. As a part of this project, instrumentation was developed to monitor cuttings beds and characterize foams in the flow loop. An ultrasonic-based monitoring system was developed to measure cuttings bed thickness in the flow loop. Data acquisition software controls the system and processes the data. Two foam generating devices were designed and developed to produce foams with specified quality and texture. The devices are equipped with a bubble recognition system and an in-line viscometer to measure bubble size distribution and foam rheology, respectively. The 5-year project is completed. Future research activities will be under the umbrella of Tulsa University Drilling Research Projects. Currently the flow loop is being used for testing cuttings transport capacity of aqueous and polymer-based foams under elevated pressure and temperature conditions. Subsequently, the effect of viscous sweeps on cuttings transport under elevated pressure and temperature conditions will be investigated using the flow loop. Other projects will follow now that the ''steady state'' phase of the project has been achieved.

  2. Method for the hydrogenation of poly-si

    DOE Patents [OSTI]

    Wang, Qi

    2013-11-12T23:59:59.000Z

    A method for hydrogenating poly-si. Poly-si is placed into the interior of a chamber. A filament is placed into the interior of a chamber. The base pressure of the interior of the chamber is evacuated, preferably to 10.sup.-6 Torr or less. The poly-si is heated for a predetermined poly-si heating time. The filament is heated by providing an electrical power to the filament. Hydrogen is supplied into the pressurized interior of the chamber comprising the heated poly-si and the heated filament. Atomic hydrogen is produced by the filament at a rate whereby the atomic hydrogen surface density at the poly-si is less than the poly-si surface density. Preferably, the poly-si is covered from the atomic hydrogen produced by the heated filament for a first predetermined covering time. Preferably, the poly-si is then uncovered from the atomic hydrogen produced by the heated filament for a first hydrogenation time.

  3. Geothermal: Sponsored by OSTI -- Final Report: 11-SI-006 Creating...

    Office of Scientific and Technical Information (OSTI)

    Final Report: 11-SI-006 Creating Optimal Fracture Networks Geothermal Technologies Legacy Collection HelpFAQ | Site Map | Contact Us HomeBasic Search About Publications Advanced...

  4. Synthesis and Characterization of Structured Si-Carbon Nanocomposite...

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

    Si-Carbon Nanocomposite Anodes and Functional Polymer Binders Vehicle Technologies Office Merit Review 2014: High Energy, Long Cycle Life Lithium-ion Batteries for EV Applications...

  5. al si alloys: Topics by E-print Network

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

    de Extensin Universitaria Red Metropolitana Red Vsquez, Carlos 488 Graeber et al. 2014 1 Supporting Information (SI Appendix) Biology and Medicine Websites...

  6. al sio2 si: Topics by E-print Network

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

    de Extensin Universitaria Red Metropolitana Red Vsquez, Carlos 497 Graeber et al. 2014 1 Supporting Information (SI Appendix) Biology and Medicine Websites...

  7. al si ti: Topics by E-print Network

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

    de Extensin Universitaria Red Metropolitana Red Vsquez, Carlos 385 Graeber et al. 2014 1 Supporting Information (SI Appendix) Biology and Medicine Websites...

  8. al si mg: Topics by E-print Network

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

    de Extensin Universitaria Red Metropolitana Red Vsquez, Carlos 374 Graeber et al. 2014 1 Supporting Information (SI Appendix) Biology and Medicine Websites...

  9. al si fe: Topics by E-print Network

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

    de Extensin Universitaria Red Metropolitana Red Vsquez, Carlos 399 Graeber et al. 2014 1 Supporting Information (SI Appendix) Biology and Medicine Websites...

  10. Sandia National Laboratories: c-Si PV materials

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

    c-Si PV materials Sandians Win 'Best Paper' Award at Photovoltaic Conference in Japan On March 4, 2015, in Computational Modeling & Simulation, Energy, Facilities, News, News &...

  11. Structural, dynamic, and vibrational properties during heat transfer in Si/Ge superlattices: A Car-Parrinello molecular dynamics study

    SciTech Connect (OSTI)

    Ji, Pengfei; Zhang, Yuwen, E-mail: zhangyu@missouri.edu [Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, Missouri 65211 (United States); Yang, Mo [College of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093 (China)

    2013-12-21T23:59:59.000Z

    The structural, dynamic, and vibrational properties during heat transfer process in Si/Ge superlattices are studied by analyzing the trajectories generated by the ab initio Car-Parrinello molecular dynamics simulation. The radial distribution functions and mean square displacements are calculated and further discussions are made to explain and probe the structural changes relating to the heat transfer phenomenon. Furthermore, the vibrational density of states of the two layers (Si/Ge) are computed and plotted to analyze the contributions of phonons with different frequencies to the heat conduction. Coherent heat conduction of the low frequency phonons is found and their contributions to facilitate heat transfer are confirmed. The Car-Parrinello molecular dynamics simulation outputs in the work show reasonable thermophysical results of the thermal energy transport process and shed light on the potential applications of treating the heat transfer in the superlattices of semiconductor materials from a quantum mechanical molecular dynamics simulation perspective.

  12. Sponge-like Si-SiO{sub 2} nanocomposite—Morphology studies of spinodally decomposed silicon-rich oxide

    SciTech Connect (OSTI)

    Friedrich, D.; Schmidt, B.; Heinig, K. H.; Liedke, B.; Mücklich, A.; Hübner, R. [Helmholtz-Zentrum Dresden – Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany)] [Helmholtz-Zentrum Dresden – Rossendorf, Bautzner Landstr. 400, 01328 Dresden (Germany); Wolf, D. [Triebenberg Laboratory, Institute of Structure Physics, Technische Universität Dresden, 01062 Dresden (Germany)] [Triebenberg Laboratory, Institute of Structure Physics, Technische Universität Dresden, 01062 Dresden (Germany); Kölling, S. [Fraunhofer Center Nanoelectronic Technologies, Königsbrücker Str. 180, 01099 Dresden (Germany)] [Fraunhofer Center Nanoelectronic Technologies, Königsbrücker Str. 180, 01099 Dresden (Germany); Mikolajick, T. [NaMLab GmbH, Nöthnitzer Str. 64, 01187 Dresden (Germany) [NaMLab GmbH, Nöthnitzer Str. 64, 01187 Dresden (Germany); Technische Universität Dresden, Nöthnitzer Str. 64, 01187 Dresden (Germany)

    2013-09-23T23:59:59.000Z

    Sponge-like Si nanostructures embedded in SiO{sub 2} were fabricated by spinodal decomposition of sputter-deposited silicon-rich oxide with a stoichiometry close to that of silicon monoxide. After thermal treatment a mean feature size of about 3 nm was found in the phase-separated structure. The structure of the Si-SiO{sub 2} nanocomposite was investigated by energy-filtered transmission electron microscopy (EFTEM), EFTEM tomography, and atom probe tomography, which revealed a percolated Si morphology. It was shown that the percolation of the Si network in 3D can also be proven on the basis of 2D EFTEM images by comparison with 3D kinetic Monte Carlo simulations.

  13. Roughness of the SiC/SiO{sub 2} vicinal interface and atomic structure of the transition layers

    SciTech Connect (OSTI)

    Liu, Peizhi; Li, Guoliang; Duscher, Gerd, E-mail: gduscher@utk.edu [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996 (United States); Sharma, Yogesh K.; Ahyi, Ayayi C.; Isaacs-Smith, Tamara; Williams, John R.; Dhar, Sarit [Department of Physics, Auburn University, Auburn, Alabama 36849 (United States)

    2014-11-01T23:59:59.000Z

    The SiC/SiO{sub 2} interface is generally considered to be the cause for the reduced electron mobility of SiC power devices. Previous studies have shown a correlation between the mobility and the transition layer width at the SiC/SiO{sub 2} interface. The authors investigated this interface with atomic resolution Z-contrast imaging and electron energy-loss spectroscopy, and discovered that this transition region was due to the roughness of the vicinal interface. The roughness of a vicinal interface consisted of atomic steps and facets deviating from the ideal off-axis cut plane. The authors conclude that this roughness is limiting the mobility in the channels of SiC MOSFETs.

  14. Effect of irradiation on the luminescence properties of low-dimensional SiGe/Si(001) heterostructures

    SciTech Connect (OSTI)

    Novikov, A. V., E-mail: anov@ipm.sci-nnov.ru; Yablonskiy, A. N. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation); Platonov, V. V. [Sarov Physicotechnical Institute (Russian Federation); Obolenskiy, S. V. [Nizhni Novgorod State University (Russian Federation); Lobanov, D. N.; Krasilnik, Z. F. [Russian Academy of Sciences, Institute for Physics of Microstructures (Russian Federation)

    2010-03-15T23:59:59.000Z

    This study is concerned with the effect of irradiation on the luminescence properties of low-dimensional Si/Ge heterostructures with different degrees of spatial localization of charge carriers. It is shown that the radiation stability of Si/Ge heterostructures is improved with increasing efficiency of localization of charge carriers in the structures. The spatial localization of charge carriers in the SiGe nanostructures decreases the probability of nonradiative recombination of charge carriers at radiation defects produced in the Si matrix. It is demonstrated that, among the structures explored in the study, the highest radiation stability of luminescence properties is inherent in the multilayered structures containing self-assembled Ge(Si) nanoislands, in which the most efficient spatial localization of charge carriers is attained. In this case, the localization is three- and two-dimensional, correspondingly, for holes in the islands and for electrons in the Si layers that separate neighboring layers containing the islands.

  15. Nanocrystalline SiC and Ti3SiC2 Alloys for Reactor Materials: Diffusion of Fission Product Surrogates

    SciTech Connect (OSTI)

    Henager, Charles H.; Jiang, Weilin

    2014-11-01T23:59:59.000Z

    MAX phases, such as titanium silicon carbide (Ti3SiC2), have a unique combination of both metallic and ceramic properties, which make them attractive for potential nuclear applications. Ti3SiC2 has been suggested in the literature as a possible fuel cladding material. Prior to the application, it is necessary to investigate diffusivities of fission products in the ternary compound at elevated temperatures. This study attempts to obtain relevant data and make an initial assessment for Ti3SiC2. Ion implantation was used to introduce fission product surrogates (Ag and Cs) and a noble metal (Au) in Ti3SiC2, SiC, and a dual-phase nanocomposite of Ti3SiC2/SiC synthesized at PNNL. Thermal annealing and in-situ Rutherford backscattering spectrometry (RBS) were employed to study the diffusivity of the various implanted species in the materials. In-situ RBS study of Ti3SiC2 implanted with Au ions at various temperatures was also performed. The experimental results indicate that the implanted Ag in SiC is immobile up to the highest temperature (1273 K) applied in this study; in contrast, significant out-diffusion of both Ag and Au in MAX phase Ti3SiC2 occurs during ion implantation at 873 K. Cs in Ti3SiC2 is found to diffuse during post-irradiation annealing at 973 K, and noticeable Cs release from the sample is observed. This study may suggest caution in using Ti3SiC2 as a fuel cladding material for advanced nuclear reactors operating at very high temperatures. Further studies of the related materials are recommended.

  16. Improvement of magnetic and structural stabilities in high-quality Co{sub 2}FeSi{sub 1?x}Al{sub x}/Si heterointerfaces

    SciTech Connect (OSTI)

    Yamada, S., E-mail: yamada@ee.es.osaka-u.ac.jp [Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531 (Japan); Tanikawa, K.; Oki, S.; Kawano, M.; Miyao, M. [Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); Hamaya, K. [Graduate School of Engineering Science, Osaka University, Toyonaka 560-8531 (Japan); CREST, Japan Science and Technology Agency, Gobancho, Tokyo 102-0075 (Japan)

    2014-08-18T23:59:59.000Z

    We study high-quality Co{sub 2}FeSi{sub 1?x}Al{sub x} Heusler compound/Si (0 ? x ? 1) heterointerfaces for silicon (Si)-based spintronic applications. In thermal treatment conditions, the magnetic and structural stabilities of the Co{sub 2}FeSi{sub 1?x}Al{sub x}/Si heterointerfaces are improved with increasing x in Co{sub 2}FeSi{sub 1?x}Al{sub x}. Compared with L2{sub 1}-ordered Co{sub 2}FeSi/Si, B2-ordered Co{sub 2}FeAl/Si can suppress the diffusion of Si atoms into the Heusler-compound structure. This experimental study will provide an important knowledge for applications in Si-based spin transistors with metallic source/drain contacts.

  17. Nanocrystalline SiC and Ti3SiC2 Alloys for Reactor Materials: Thermal and Mechanical Properties

    SciTech Connect (OSTI)

    Henager, Charles H.; Alvine, Kyle J.; Roosendaal, Timothy J.; Shin, Yongsoon; Nguyen, Ba Nghiep; Borlaug, Brennan A.; Jiang, Weilin

    2014-04-01T23:59:59.000Z

    SiC-polymers (pure polycarbosilane and polycarbosilane filled with SiC-particles) are being combined with Si and TiC powders to create a new class of polymer-derived ceramics for consideration as advanced nuclear materials in a variety of applications. Compared to pure SiC these materials have increased fracture toughness with only slightly reduced thermal conductivity. Future work with carbon nanotube (CNT) mats will be introduced with the potential to increase the thermal conductivity and the fracture toughness. At present, this report documents the fabrication of a new class of monolithic polymer derived ceramics, SiC + SiC/Ti3SiC2 dual phase materials. The fracture toughness of the dual phase material was measured to be significantly greater than Hexoloy SiC using indentation fracture toughness testing. However, thermal conductivity of the dual phase material was reduced compared to Hexoloy SiC, but was still appreciable, with conductivities in the range of 40 to 60 W/(m K). This report includes synthesis details, optical and scanning electron microscopy images, compositional data, fracture toughness, and thermal conductivity data.

  18. Analysis of X-Ray Diffraction as a Probe of Interdiffusion in Si/SiGe Heterostructures

    SciTech Connect (OSTI)

    Brennan, Sean M

    2003-08-20T23:59:59.000Z

    We investigate numerical simulations that utilize a non-linear interdiffusion solver and dynamical x-ray diffraction calculations to predict the local composition evolution in low Ge concentration Si/SiGe superlattices and their diffraction patterns during annealing. Superlattice satellite peak decay rates are compared with experimentally measured values and simulated diffraction patterns are matched directly to data with good success. The simulations are used to test the sensitivity of x-ray diffraction to various uncertainties commonly encountered when measuring interdiffusion at Si/SiGe interfaces. It is found that the most serious errors result from variations in the Ge content across the surface of the wafer. For example, the resolution limit of most experimental techniques used to measure Ge concentration in a SiGe film is -1 at.%, for a film with 11% mean Ge concentration annealed for 5 hours at 870 C, this level of error will cause the observed interdiffusivity values to deviate by -25% or +50%. The simulations are further used to show that for Si/SiGe interdiffusion, superlattice diffraction produces valid measurements when applied to 004 superlattice satellite peaks and square wave composition modulations even though it is only exactly applicable to satellite peaks about 000 reflection and to sinusoidal composition modulations. Finally, we show that proper interpretation of x-ray scattering data to extract Si/SiGe interdiffusivity values must account for the strong dependence of the interdiffusivity on Ge concentration.

  19. Serial and parallel Si, Ge, and SiGe direct-write with scanning probes and conducting stamps

    SciTech Connect (OSTI)

    Vasko, Stephanie E.; Kapetanovic, Adnan; Talla, Vamsi; Brasino, Michael D.; Zhu, Zihua; Scholl, Andreas; Torrey, Jessica D.; Rolandi, Marco

    2011-05-16T23:59:59.000Z

    Precise materials integration in nanostructures is fundamental for future electronic and photonic devices. We demonstrate Si, Ge, and SiGe nanostructure direct-write with deterministic size, geometry, and placement control. The biased probe of an atomic force microscope (AFM) reacts diphenylsilane or diphenylgermane to direct-write carbon-free Si, Ge, and SiGe nano and heterostructures. Parallel directwrite is available on large areas by substituting the AFM probe with conducting microstructured stamps. This facile strategy can be easily expanded to a broad variety of semiconductor materials through precursor selection.

  20. Monolithic integration of AlGaInP laser diodes on SiGe/Si substrates by molecular beam epitaxy

    SciTech Connect (OSTI)

    Kwon, O.; Boeckl, J. J.; Lee, M. L.; Pitera, A. J.; Fitzgerald, E. A.; Ringel, S. A. [Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States); Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

    2006-07-01T23:59:59.000Z

    Room temperature operation of visible AlGaInP laser diodes epitaxially integrated on Si was demonstrated. Compressively strained laser heterostructures were grown by molecular beam epitaxy (MBE) on low dislocation density SiGe/Si substrates, where the threading dislocation density of the top relaxed Ge layers was measured in the range of 2x10{sup 6} cm{sup -2}. A threshold current density of J{sub th}{approx}1.65 kA/cm{sup 2} for the as-cleaved, gain-guided AlGaInP laser grown on SiGe/Si was obtained at the peak emission wavelength of 680 nm under pulsed mode current injection. These results show that not only can high quality AlGaInP materials grown by MBE be achieved on Si via relaxed SiGe interlayers, but the prototype demonstration of laser diode operation on Si illustrates that very defect sensitive optoelectronics in the III-P system can indeed be integrated with Si substrates by heteroepitaxial methods.

  1. Ceramic Technology Project database: September 1990 summary report. [SiC, SiN, whisker-reinforced SiN, ZrO-toughened aluminas, zirconias, joints

    SciTech Connect (OSTI)

    Keyes, B.L.P.

    1992-06-01T23:59:59.000Z

    Data generated within the Ceramic Technology Project (CTP) represent a valuable resource for both research and industry. The CTP database was created to provide easy access to this information in electronic and hardcopy forms by using a computerized database and by issuing periodic hardcopy reports on the database contents. This report is the sixth in a series of semiannual database summaries and covers recent additions to the database, including joined brazed specimen test data. It covers 1 SiC, 34 SiN, 10 whisker-reinforced SiN, 2 zirconia-toughened aluminas, 8 zirconias, and 34 joints.

  2. Transport Model with Quasipions

    E-Print Network [OSTI]

    Xiong, L.; Ko, Che Ming; Koch, V.

    1993-01-01T23:59:59.000Z

    , the transport model that takes into account both nucleon-nucleon collisions and the nuclear mean-field po- tential (normally called the Ulasov-Uehling-Uhlenbeck or Boltzmann-Uehling-Uhlenbeck model [3]) have been ex- tended to include the pion degree... equation, the pion collision term is obtained from the imaginary part of its self-energy. In nuclear medium, the pion self-energy is modified by the strong p-wave pion- nucleon interaction. This not only afFects the production and absorption of the pion...

  3. Transportation Politics and Policy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What'sis Taking Over OurThe Iron Spin Transition in2, 2003ToolsearchTransportation Equipment

  4. Sandia Energy - Transportation Safety

    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 Home DistributionTransportation Safety Home Stationary Power Nuclear Fuel Cycle

  5. Natural Gas Transportation Resiliency

    Energy Savers [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 being directed offOCHCO2:Introduction toManagement ofConverDyn NOPRNancyNationalNatural GasImports byTransportation

  6. Transportation Storage Interface

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently AskedEnergyIssuesEnergyTransportation Work Package Reports | DepartmentAT THE

  7. National Transportation Stakeholders Forum

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742 33Frequently Asked QuestionsDepartment of EnergyofPROTECTING ENERGYGrid Study U.S.TRANSPORTATION

  8. Transportation Statistics Annual Report 1997

    SciTech Connect (OSTI)

    Fenn, M.

    1997-01-01T23:59:59.000Z

    This document is the fourth Transportation Statistics Annual Report (TSAR) prepared by the Bureau of Transportation Statistics (BTS) for the President and Congress. As in previous years, it reports on the state of U.S. transportation system at two levels. First, in Part I, it provides a statistical and interpretive survey of the system—its physical characteristics, its economic attributes, aspects of its use and performance, and the scale and severity of unintended consequences of transportation, such as fatalities and injuries, oil import dependency, and environment impacts. Part I also explores the state of transportation statistics, and new needs of the rapidly changing world of transportation. Second, Part II of the report, as in prior years, explores in detail the performance of the U.S. transportation system from the perspective of desired social outcomes or strategic goals. This year, the performance aspect of transportation chosen for thematic treatment is “Mobility and Access,” which complements past TSAR theme sections on “The Economic Performance of Transportation” (1995) and “Transportation and the Environment” (1996). Mobility and access are at the heart of the transportation system’s performance from the user’s perspective. In what ways and to what extent does the geographic freedom provided by transportation enhance personal fulfillment of the nation’s residents and contribute to economic advancement of people and businesses? This broad question underlies many of the topics examined in Part II: What is the current level of personal mobility in the United States, and how does it vary by sex, age, income level, urban or rural location, and over time? What factors explain variations? Has transportation helped improve people’s access to work, shopping, recreational facilities, and medical services, and in what ways and in what locations? How have barriers, such as age, disabilities, or lack of an automobile, affected these accessibility patterns? How are commodity flows and transportation services responding to global competition, deregulation, economic restructuring, and new information technologies? How do U.S. patterns of personal mobility and freight movement compare with other advanced industrialized countries, formerly centrally planned economies, and major newly industrializing countries? Finally, how is the rapid adoption of new information technologies influencing the patterns of transportation demand and the supply of new transportation services? Indeed, how are information technologies affecting the nature and organization of transportation services used by individuals and firms?

  9. Western Australian Hub of SiMERR Australia (National Centre of Science, ICT and

    E-Print Network [OSTI]

    SiMERR WA Western Australian Hub of SiMERR Australia (National Centre of Science, ICT and Mathematics Education for Rural and Regional Australia) Background Since 2005 SiMERR WA, the Western Australian Hub of SiMERR Australia, has been led by a team of academics from Curtin University. Si

  10. OPTIMIZATION OF a-SiGe BASED TRIPLE, TANDEM AND SINGLE-JUNCTION SOLAR Xunming Deng

    E-Print Network [OSTI]

    Deng, Xunming

    OPTIMIZATION OF a-SiGe BASED TRIPLE, TANDEM AND SINGLE-JUNCTION SOLAR CELLS Xunming Deng Department cells, all employing high- quality a-SiGe cells, are reviewed in this paper. Incorporating various improvements in device fabrication, the UT group fabricated 1) triple-junction a-Si/a-SiGe/a- SiGe solar cells

  11. SiGe-On-Insulator (SGOI): Two Structures for CMOS Application

    E-Print Network [OSTI]

    SiGe-On-Insulator (SGOI): Two Structures for CMOS Application Zhiyuan Cheng,a) Jongwan Jung, b Massachusetts Avenue, Cambridge, MA 02141 a) E-mail: cheng@alum.MIT.EDU Abstract ­ Two SiGe-on-insulator (SGOI enhancement on both electron and hole mobilities. Keywords ­ strained-Si, SiGe, SiGe-on-Insulator, SGOI

  12. Nanoengineered membranes for controlled transport

    DOE Patents [OSTI]

    Doktycz, Mitchel J. (Oak Ridge, TN) [Oak Ridge, TN; Simpson, Michael L. (Knoxville, TN) [Knoxville, TN; McKnight, Timothy E. (Greenback, TN) [Greenback, TN; Melechko, Anatoli V. (Oak Ridge, TN) [Oak Ridge, TN; Lowndes, Douglas H. (Knoxville, TN) [Knoxville, TN; Guillorn, Michael A. (Knoxville, TN) [Knoxville, TN; Merkulov, Vladimir I. (Oak Ridge, TN) [Oak Ridge, TN

    2010-01-05T23:59:59.000Z

    A nanoengineered membrane for controlling material transport (e.g., molecular transport) is disclosed. The membrane includes a substrate, a cover definining a material transport channel between the substrate and the cover, and a plurality of fibers positioned in the channel and connected to an extending away from a surface of the substrate. The fibers are aligned perpendicular to the surface of the substrate, and have a width of 100 nanometers or less. The diffusion limits for material transport are controlled by the separation of the fibers. In one embodiment, chemical derivitization of carbon fibers may be undertaken to further affect the diffusion limits or affect selective permeability or facilitated transport. For example, a coating can be applied to at least a portion of the fibers. In another embodiment, individually addressable carbon nanofibers can be integrated with the membrane to provide an electrical driving force for material transport.

  13. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect (OSTI)

    Troy Reed; Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mark Pickell; Len Volk; Mike Volk; Lei Zhou; Zhu Chen; Crystal Redden; Aimee Washington

    2003-07-30T23:59:59.000Z

    This Quarter has been divided between running experiments and the installation of the drill-pipe rotation system. In addition, valves and piping were relocated, and three viewports were installed. Detailed design work is proceeding on a system to elevate the drill-string section. Design of the first prototype version of a Foam Generator has been finalized, and fabrication is underway. This will be used to determine the relationship between surface roughness and ''slip'' of foams at solid boundaries. Additional cups and rotors are being machined with different surface roughness. Some experiments on cuttings transport with aerated fluids have been conducted at EPET. Theoretical modeling of cuttings transport with aerated fluids is proceeding. The development of theoretical models to predict frictional pressure losses of flowing foam is in progress. The new board design for instrumentation to measure cuttings concentration is now functioning with an acceptable noise level. The ultrasonic sensors are stable up to 190 F. Static tests with sand in an annulus indicate that the system is able to distinguish between different sand concentrations. Viscometer tests with foam, generated by the Dynamic Test Facility (DTF), are continuing.

  14. ELECTROCHEMICAL POWER FOR TRANSPORTATION

    SciTech Connect (OSTI)

    Cairns, Elton J.; Hietbrink, Earl H.

    1981-01-01T23:59:59.000Z

    This section includes some historical background of the rise and fall and subsequent rebirth of the electric vehicle; and a brief discussion of current transportation needs, and environmental and energy utilization issues that resulted in the renewed interest in applying electrochemical energy conversion technology to electric vehicle applications. Although energy utilization has evolved to be the most significant and important issue, the environmental issue will be discussed first in this section only because of its chronological occurrence. The next part of the chapter is a review of passenger and commercial electric vehicle technology with emphasis on vehicle design and demonstrated performance of vehicles with candidate power sources being developed. This is followed by a discussion of electrochemical power source requirements associated with future electric vehicles that can play a role in meeting modern transportation needs. The last part of the chapter includes first a discussion of how to identify candidate electrochemical systems that might be of interest in meeting electric vehicle power source requirements. This is then followed by a review of the current technological status of these systems and a discussion of the most significant problems that must be resolved before each candidate system can be a viable power source.

  15. Streamlining Transportation Corridor Planning Processess: Freight and Traffic Information

    SciTech Connect (OSTI)

    Franzese, Oscar [ORNL

    2010-08-01T23:59:59.000Z

    The traffic investigation is one of the most important parts of an Environmental Impact Statement of projects involving the construction of new roadway facilities and/or the improvement of existing ones. The focus of the traffic analysis is on the determination of anticipated traffic flow characteristics of the proposed project, by the application of analytical methods that can be grouped under the umbrella of capacity analysis methodologies. In general, the main traffic parameter used in EISs to describe the quality of traffic flow is the Level of Service (LOS). The current state of the practice in terms of the traffic investigations for EISs has two main shortcomings. The first one is related to the information that is necessary to conduct the traffic analysis, and specifically to the lack of integration among the different transportation models and the sources of information that, in general, reside in GIS databases. A discussion of the benefits of integrating CRS&SI technologies and the transportation models used in the EIS traffic investigation is included. The second shortcoming is in the presentation of the results, both in terms of the appearance and formatting, as well as content. The presentation of traffic results (current and proposed) is discussed. This chapter also addresses the need of additional data, in terms of content and coverage. Regarding the former, other traffic parameters (e.g., delays) that are more meaningful to non-transportation experts than LOS, as well as additional information (e.g., freight flows) that can impact traffic conditions and safety are discussed. Spatial information technologies can decrease the negative effects of, and even eliminate, these shortcomings by making the relevant information that is input to the models more complete and readily available, and by providing the means to communicate the results in a more clear and efficient manner. The benefits that the application and use of CRS&SI technologies can provide to improve and expedite the traffic investigation part of the EIS process are presented.

  16. Flex Fuel Optimized SI and HCCI Engine

    SciTech Connect (OSTI)

    Zhu, Guoming; Schock, Harold; Yang, Xiaojian; Huisjen, Andrew; Stuecken, Tom; Moran, Kevin; Zhen, Ron; Zhang, Shupeng

    2013-09-30T23:59:59.000Z

    The central objective of the proposed work is to demonstrate an HCCI (homogeneous charge compression ignition) capable SI (spark ignited) engine that is capable of fast and smooth mode transition between SI and HCCI combustion modes. The model-based control technique was used to develop and validate the proposed control strategy for the fast and smooth combustion mode transition based upon the developed control-oriented engine; and an HCCI capable SI engine was designed and constructed using production ready two-step valve-train with electrical variable valve timing actuating system. Finally, smooth combustion mode transition was demonstrated on a metal engine within eight engine cycles. The Chrysler turbocharged 2.0L I4 direct injection engine was selected as the base engine for the project and the engine was modified to fit the two-step valve with electrical variable valve timing actuating system. To develop the model-based control strategy for stable HCCI combustion and smooth combustion mode transition between SI and HCCI combustion, a control-oriented real-time engine model was developed and implemented into the MSU HIL (hardware-in-the-loop) simulation environment. The developed model was used to study the engine actuating system requirement for the smooth and fast combustion mode transition and to develop the proposed mode transition control strategy. Finally, a single cylinder optical engine was designed and fabricated for studying the HCCI combustion characteristics. Optical engine combustion tests were conducted in both SI and HCCI combustion modes and the test results were used to calibrate the developed control-oriented engine model. Intensive GT-Power simulations were conducted to determine the optimal valve lift (high and low) and the cam phasing range. Delphi was selected to be the supplier for the two-step valve-train and Denso to be the electrical variable valve timing system supplier. A test bench was constructed to develop control strategies for the electrical variable valve timing (VVT) actuating system and satisfactory electrical VVT responses were obtained. Target engine control system was designed and fabricated at MSU for both single-cylinder optical and multi-cylinder metal engines. Finally, the developed control-oriented engine model was successfully implemented into the HIL simulation environment. The Chrysler 2.0L I4 DI engine was modified to fit the two-step vale with electrical variable valve timing actuating system. A used prototype engine was used as the base engine and the cylinder head was modified for the two-step valve with electrical VVT actuating system. Engine validation tests indicated that cylinder #3 has very high blow-by and it cannot be reduced with new pistons and rings. Due to the time constraint, it was decided to convert the four-cylinder engine into a single cylinder engine by blocking both intake and exhaust ports of the unused cylinders. The model-based combustion mode transition control algorithm was developed in the MSU HIL simulation environment and the Simulink based control strategy was implemented into the target engine controller. With both single-cylinder metal engine and control strategy ready, stable HCCI combustion was achived with COV of 2.1% Motoring tests were conducted to validate the actuator transient operations including valve lift, electrical variable valve timing, electronic throttle, multiple spark and injection controls. After the actuator operations were confirmed, 15-cycle smooth combustion mode transition from SI to HCCI combustion was achieved; and fast 8-cycle smooth combustion mode transition followed. With a fast electrical variable valve timing actuator, the number of engine cycles required for mode transition can be reduced down to five. It was also found that the combustion mode transition is sensitive to the charge air and engine coolant temperatures and regulating the corresponding temperatures to the target levels during the combustion mode transition is the key for a smooth combustion mode transition. As a summary, the proposed combust

  17. Spent fuel integrity during transportation

    SciTech Connect (OSTI)

    Funk, C.W.; Jacobson, L.D.

    1980-01-01T23:59:59.000Z

    The conditions of recent shipments of light water reactor spent fuel were surveyed. The radioactivity level of cask coolant was examined in an attempt to find the effects of transportation on LWR fuel assemblies. Discussion included potential cladding integrity loss mechanisms, canning requirements, changes of radioactivity levels, and comparison of transportation in wet or dry media. Although integrity loss or degradation has not been identified, radioactivity levels usually increase during transportation, especially for leaking assemblies.

  18. Microbial Transport in the Subsurface

    SciTech Connect (OSTI)

    Ginn, Timothy R.; Camesano, Terri; Scheibe, Timothy D.; Nelson, Kirk B.; Clement, T. P.; Wood, Brian D.

    2005-12-01T23:59:59.000Z

    In this article we focus on the physical, chemical, and biological processes involved in the transport of bacteria in the saturated subsurface. We will first review conceptual models of bacterial phases in the subsurface, and then the processes controlling fate and transport on short (e.g., bioremediation) time scales. Finally we briefly review field bacterial transport experiments and discuss a number of issues that impact the application of current process descriptions and models at the field scale.

  19. Functional Delivery of siRNA in Mice Using Dendriworms

    E-Print Network [OSTI]

    Bhatia, Sangeeta

    Functional Delivery of siRNA in Mice Using Dendriworms Amit Agrawal, Dal-Hee Min, Neetu Singh, Massachusetts 02115 S mall interfering RNAs (siRNAs) are 21 23 nucleotide double strand nu- cleic acid molecules research groups have used quan- tum dots,16 magnetic17 and gold nanoparticles18,19 as well as carbon nano

  20. The role of lattice excitation in Si etching

    E-Print Network [OSTI]

    Blair, Michael Ryan

    2014-01-01T23:59:59.000Z

    The chemistries of fluorine, F?, and xenon difluoride, XeF?, with clean Si are basically the same, while their chemistries diverge dramatically past I ML F coverage. With a clean Si surface, F? and XeF? react utilizing an ...

  1. Band-engineered Ge-on-Si lasers

    E-Print Network [OSTI]

    Liu, Jifeng

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

  2. Si?-implanted Si-wire waveguide photodetectors for the mid-infrared

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

    Souhan, Brian; Lu, Ming; Grote, Richard R.; Chen, Christine P.; Huang, Hsu-Cheng; Driscoll, Jeffrey B.; Stein, Aaron; Bakhru, Hassaram; Bergman, Keren; Green, William M. J.; et al

    2014-01-01T23:59:59.000Z

    CMOS-compatible Si?-implanted Si-waveguide p-i-n photodetectors operating at room temperature and at mid-infrared wavelengths from 2.2 to 2.3 µm are demonstrated. Responsivities of 9.9 ± 2.0 mA/W are measured at a 5 V reverse bias with an estimated internal quantum efficiency of 2.7 – 4.5%. The dark current is found to vary from a few microamps down to less than a nanoamp after a post-implantation annealing of 350°C. The measured photocurrent dependence on input power shows a linear correspondence over more than three decades, and the frequency response of a 250 µm-length p-i-n device is measured to be ~1.7 GHz formore »a wavelength of ? = 2.2 µm, thus potentially opening up new communication bands for photonic integrated circuits.« less

  3. Si?-implanted Si-wire waveguide photodetectors for the mid-infrared

    SciTech Connect (OSTI)

    Souhan, Brian [Columbia Univ., New York, NY (United States); Lu, Ming [Brookhaven National Lab. (BNL), Upton, NY (United States); Grote, Richard R. [Columbia Univ., New York, NY (United States); Chen, Christine P. [Columbia Univ., New York, NY (United States); Huang, Hsu-Cheng [Columbia Univ., New York, NY (United States); Driscoll, Jeffrey B. [Columbia Univ., New York, NY (United States); Stein, Aaron [Brookhaven National Lab. (BNL), Upton, NY (United States); Bakhru, Hassaram [State Univ. of New York at Albany, Albany, NY (United States); Bergman, Keren [Columbia Univ., New York, NY (United States); Green, William M. J. [IBM, Yorktown Heights, NY (United States). Thomas J. Watson Research Center; Osgood, Jr., Richard M. [Columbia Univ., New York, NY (United States)

    2014-01-01T23:59:59.000Z

    CMOS-compatible Si?-implanted Si-waveguide p-i-n photodetectors operating at room temperature and at mid-infrared wavelengths from 2.2 to 2.3 µm are demonstrated. Responsivities of 9.9 ± 2.0 mA/W are measured at a 5 V reverse bias with an estimated internal quantum efficiency of 2.7 – 4.5%. The dark current is found to vary from a few microamps down to less than a nanoamp after a post-implantation annealing of 350°C. The measured photocurrent dependence on input power shows a linear correspondence over more than three decades, and the frequency response of a 250 µm-length p-i-n device is measured to be ~1.7 GHz for a wavelength of ? = 2.2 µm, thus potentially opening up new communication bands for photonic integrated circuits.

  4. Electronic structures of GeSi nanoislands grown on pit-patterned Si(001) substrate

    SciTech Connect (OSTI)

    Ye, Han, E-mail: Dabombyh@aliyun.com; Yu, Zhongyuan [State Key Laboratory of Information Photonics and Optical Communications, Beijing University of Posts and Telecommunications, Beijing 100876, P.R.China (China)

    2014-11-15T23:59:59.000Z

    Patterning pit on Si(001) substrate prior to Ge deposition is an important approach to achieve GeSi nanoislands with high ordering and size uniformity. In present work, the electronic structures of realistic uncapped pyramid, dome, barn and cupola nanoislands grown in (105) pits are systematically investigated by solving Schrödinger equation for heavy-hole, which resorts to inhomogeneous strain distribution and nonlinear composition-dependent band parameters. Uniform, partitioned and equilibrium composition profile (CP) in nanoisland and inverted pyramid structure are simulated separately. We demonstrate the huge impact of composition profile on localization of heavy-hole: wave function of ground state is confined near pit facets for uniform CP, at bottom of nanoisland for partitioned CP and at top of nanoisland for equilibrium CP. Moreover, such localization is gradually compromised by the size effect as pit filling ratio or pit size decreases. The results pave the fundamental guideline of designing nanoislands on pit-patterned substrates for desired applications.

  5. Modeling the plastic relaxation onset in realistic SiGe islands on Si(001)

    SciTech Connect (OSTI)

    Gatti, R.; Marzegalli, A.; Montalenti, F.; Miglio, Leo [Dipartimento di Scienza dei Materiali and L-NESS, Universita degli Studi di Milano-Bicocca, Via Cozzi 53, I-20125 Milano (Italy); Zinovyev, V. A. [Institute of Semiconductor Physics, Novosibirsk 630090 (Russian Federation)

    2008-11-01T23:59:59.000Z

    A detailed investigation of plastic relaxation onset in heteroepitaxial SiGe islands on Si(001) is presented. The strain field induced by a straight misfit-dislocation segment is modeled by finite-element-method (FEM) calculations in three dimensions, fully taking into account the interaction with the multifaceted free surfaces of realistic islands. The total elastic energies before and after the placement of a 60 deg. dislocation segment in the most favorable position are therefore evaluated by a full FEM approach, for different island sizes and compositions. The critical volumes with composition for inserting the dislocation are finally obtained and successfully compared with the data in a report by Marzegalli et al. [Phys. Rev. Lett. 99, 235505 (2007)], where experimental values are compared to a simpler approach.

  6. Charge Relaxation in a Single Electron Si/SiGe Double Quantum Dot

    E-Print Network [OSTI]

    K. Wang; C. Payette; Y. Dovzhenko; P. W. Deelman; J. R. Petta

    2013-04-15T23:59:59.000Z

    We measure the interdot charge relaxation time T_1 of a single electron trapped in an accumulation mode Si/SiGe double quantum dot. The energy level structure of the charge qubit is determined using photon assisted tunneling, which reveals the presence of a low lying excited state. We systematically measure T_1 as a function of detuning and interdot tunnel coupling and show that it is tunable over four orders of magnitude, with a maximum of 45 microseconds for our device configuration. Measured relaxation times are consistent with a phonon mediated energy relaxation process and indicate that low lying excited states may have important implications in the development of silicon spin qubits.

  7. Local equilibrium and global relaxation of strained SiGe/Si(001) layers

    SciTech Connect (OSTI)

    Stoffel, M.; Rastelli, A.; Merdzhanova, T.; Schmidt, O. G. [Max-Planck-Institut fuer Festkoerperforschung, Heisenbergstrasse 1, 70569 Stuttgart (Germany); Tersoff, J. [IBM Research Division, T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States)

    2006-10-15T23:59:59.000Z

    We investigate the morphological evolution of islands obtained by epitaxial growth of Ge on Si(001) substrates. We are able to obtain highly uniform distributions of SiGe islands, which exhibit a 'barn' shape. In addition to previously observed facets, we identify higher index facets, which are not observed in dome-shaped islands. The evolution of the island-related facet area provides evidence of a transition from domes to steeper barns, which continues the sequence of coherent island types before the onset of plastic relaxation. For higher Ge coverages, when plastically relaxed islands (superdomes) form, the island ensemble loses its homogeneity. This is essentially the result of anomalous coarsening, with material being transferred from coherent islands to larger superdomes.

  8. Localized Si enrichment in coherent self-assembled Ge islands grown by molecular beam epitaxy on (001)Si single crystal

    SciTech Connect (OSTI)

    Valvo, M. [Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95127 Catania (Italy); Bongiorno, C.; Giannazzo, F. [IMM-CNR, VIII strada 5, 95121 Catania (Italy); Terrasi, A. [Dipartimento di Fisica e Astronomia, Universita di Catania, Via S. Sofia 64, I-95127 Catania (Italy); MATIS IMM-CNR UOS Catania (Universita), via S. Sofia 64, 95123 Catania (Italy)

    2013-01-21T23:59:59.000Z

    Transmission electron microscopy (TEM), atomic force microscopy, and Rutherford backscattering spectrometry (RBS) have been used to investigate the morphology, structure, and composition of self-assembled Ge islands grown on Si (001) substrates by molecular beam epitaxy (MBE) at different temperatures. Increasing the temperature from 550 Degree-Sign C to 700 Degree-Sign C causes progressive size and shape uniformity, accompanied by enhanced Si-Ge intermixing within the islands and their wetting layer. Elemental maps obtained by energy filtered-TEM (EF-TEM) clearly show pronounced Si concentration not only in correspondence of island base perimeters, but also along their curved surface boundaries. This phenomenon is strengthened by an increase of the growth temperature, being practically negligible at 550 Degree-Sign C, while very remarkable already at 650 Degree-Sign C. The resulting island shape is affected, since this localized Si enrichment not only provides strain relief near their highly stressed base perimeters but it also influences the cluster surface energy by effective alloying, so as to form Si-enriched SiGe interfaces. Further increase to 700 Degree-Sign C causes a shape transition where more homogenous Si-Ge concentration profiles are observed. The crucial role played by local 'flattened' alloyed clusters, similar to truncated pyramids with larger bases and enhanced Si enrichment at coherently stressed interfaces, has been further clarified by EF-TEM analysis of a multi-layered Ge/Si structure containing stacked Ge islands grown at 650 Degree-Sign C. Sharp accumulation of Si has been here observed not only in proximity of the uncapped island surface in the topmost layer but also at the buried Ge/Si interfaces and even in the core of such capped Ge islands.

  9. Modeling Radionuclide Transport in Clays

    E-Print Network [OSTI]

    Zheng, L.

    2014-01-01T23:59:59.000Z

    Radionuclide Transport in Clays May 2012 Zheng, L. , J.a single sample of Opalinus Clay. Geochimica et Cosmochimicaadsorption onto kaolinite based clay minerals using FITEQL

  10. Transport Properties for Combustion Modeling

    E-Print Network [OSTI]

    Brown, N.J.

    2010-01-01T23:59:59.000Z

    a critical role in combustion processes just as chemicalparameters are essential for combustion modeling; molecularwith Application to Combustion. Transport Theor Stat 2003;

  11. Alternative Transportation Technologies: Hydrogen, Biofuels,...

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

    Alternative Transportation Technologies: Hydrogen, Biofuels, Advanced Efficiency, and Plug-in Hybrid Electric Vehicles Results of two Reports from the National Research Council...

  12. Inverse Problems in Transport Theory

    E-Print Network [OSTI]

    The inverse scattering problem for (2.1) is the following: Does S determine ...... J. Voigt, Spectral properties of the neutron transport equation, J. Math. Anal. Appl.

  13. Transportation and Greenhouse Gas Mitigation

    E-Print Network [OSTI]

    Lutsey, Nicholas P.; Sperling, Dan

    2008-01-01T23:59:59.000Z

    thereby contributing to energy security. Most also reducesuch as improved energy security, many transport GHGincluding energy cost savings, oil security, and pollution

  14. OVERVIEW OF PROPOSED TRANSPORTATION ENERGY

    E-Print Network [OSTI]

    ......................................................................................................................12 California Freight Energy Demand Model..............................................................................................13 California Transit Energy Demand ModelOVERVIEW OF PROPOSED TRANSPORTATION ENERGY ANALYSES FOR THE 2007 INTEGRATED ENERGY POLICY REPORT

  15. Sandia National Laboratories: Transportation Energy

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

    News, News & Events, Research & Capabilities, Sensors & Optical Diagnostics, Transportation Energy Allowing single-shot measurements of all major species in nonsooting flames...

  16. Sandia National Laboratories: Transportation Energy

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

    Facilities, News, News & Events, Research & Capabilities, Systems Analysis, Transportation Energy By combining advanced theory and high-fidelity large eddy simulation,...

  17. Hazardous Waste Transporter Permits (Connecticut)

    Broader source: Energy.gov [DOE]

    Transportation of hazardous wastes into or through the State of Connecticut requires a permit. Some exceptions apply. The regulations provide information about obtaining permits and other permit...

  18. Alternative Transportation Technologies: Hydrogen, Biofuels,...

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

    Transportation Technologies: Hydrogen, Biofuels, Advanced Efficiency, and Plug-in Hybrid Electric Vehicles Presented at the U.S. Department of Energy Light Duty Vehicle...

  19. Sidewall damage in plasma etching of Si/SiGe heterostructures

    SciTech Connect (OSTI)

    Ding, R.; Klein, L. J.; Friesen, Mark G.; Eriksson, M. A.; Wendt, A. E. [Materials Science Program, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); IBM TJ Watson Research Center, Yorktown Heights, New York 10598 (United States); Department of Physics, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States); Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison, Wisconsin 53706 (United States)

    2009-07-15T23:59:59.000Z

    Plasma etching is a critical tool in the fabrication of Si/SiGe heterostructure quantum devices, but it also presents challenges, including damage to etched feature sidewalls that affects device performance. Chemical and structural changes in device feature sidewalls associated with plasma-surface interactions are considered damage, as they affect band structure and electrical conduction in the active region of the device. Here the authors report the results of experiments designed to better understand the mechanisms of plasma-induced sidewall damage in modulation-doped Si/SiGe heterostructures containing a two-dimensional electron gas. Damage to straight wires fabricated in the heterostructure using plasma etching was characterized both by measuring the width of the nonconductive ''sidewall depletion'' region at the device sidewall and by measuring the noise level factor {gamma}{sub H}/N determined from spectra of the low frequency noise. Observed increases in sidewall depletion width with increasing etch depth are tentatively attributed to the increase in total number of sidewall defects with increased plasma exposure time. Excess negative charge trapped on the feature sidewall could be another contributing factor. Defects at the bottom of etched features appear to contribute minimally. The noise level shows a minimum at an ion bombardment energy of {approx}100 eV, while the sidewall depletion width is independent of bias voltage, within experimental uncertainty. A proposed explanation of the noise trend involves two competing effects as ion energy increases: the increase in damage caused by each bombarding ion and the reduction in total number of incident ions due to shorter etch times.

  20. Climate and Transportation Solutions: Findings from the 2009 Asilomar Conference on Transportation and Energy Policy

    E-Print Network [OSTI]

    Sperling, Daniel; Cannon, James S.

    2010-01-01T23:59:59.000Z

    Chapter 2 Climate and Transportation Solutions Chapter 3:Gas Emissions in the Transportation Sector by John Conti,Chase, and John Maples Transportation is the single largest

  1. Hot metal Si control at Kwangyang blast furnaces

    SciTech Connect (OSTI)

    Hur, N.S.; Cho, B.R.; Kim, G.Y.; Choi, J.S.; Kim, B.H. [POSCO, Cheollanamdo (Korea, Republic of). Kwangyang Works

    1995-12-01T23:59:59.000Z

    Studies of Si transfer in blast furnaces have shown that the Si level in pig iron is influenced more by the reaction of silicon oxide gas generation in the raceway than the chemical reaction between hot metal and slag at the drop zone. Specifications require a Si content of pig iron below 0.15% at the Kwangyang Works, but the use of soft coking coal in the blend for coke ovens, high pulverized coal injection rate into the blast furnace, and the application of lower grade iron ore has resulted in the need to develop methods to control Si in hot metal. In this paper, the results of in furnace Si control and the desiliconization skills at the casthouse floor are described.

  2. Mechanistic Selection and Growth of Twinned Bicrystalline Primary Si in Near Eutectic Al-Si Alloys

    SciTech Connect (OSTI)

    Choonho Jung

    2006-12-12T23:59:59.000Z

    Morphological evolution and selection of angular primary silicon is investigated in near-eutectic Al-Si alloys. Angular silicon arrays are grown directionally in a Bridgman furnace at velocities in the regime of 10{sup -3} m/sec and with a temperature gradient of 7.5 x 10{sup 3} K/m. Under these conditions, the primary Si phase grows as an array of twinned bicrystalline dendrites, where the twinning gives rise to a characteristic 8-pointed star-shaped primary morphology. While this primary Si remains largely faceted at the growth front, a complex structure of coherent symmetric twin boundaries enables various adjustment mechanisms which operate to optimize the characteristic spacings within the primary array. In the work presented here, this primary silicon growth morphology is examined in detail. In particular, this thesis describes the investigation of: (1) morphological selection of the twinned bicrystalline primary starshape morphology; (2) primary array behavior, including the lateral propagation of the starshape grains and the associated evolution of a strong <100> texture; (3) the detailed structure of the 8-pointed star-shaped primary morphology, including the twin boundary configuration within the central core; (4) the mechanisms of lateral propagation and spacing adjustment during array evolution; and (5) the thermosolutal conditions (i.e. operating state) at the primary growth front, including composition and phase fraction in the vicinity of the primary tip.

  3. Cooling Power Density of SiGe/Si Superlattice Micro Refrigerators Gehong Zeng, Xiaofeng Fan, Chris LaBounty, Edward Croke2

    E-Print Network [OSTI]

    Bowers, John

    Cooling Power Density of SiGe/Si Superlattice Micro Refrigerators Gehong Zeng, Xiaofeng Fan, Chris Experiments were carried out to determine the cooling power density of SiGe/Si superlattice microcoolers by integrating thin film metal resistor heaters on the cooling surface. By evaluating the maximum cooling

  4. Things to do early in the semester 1. Allow your SI Leader surveys class for the most popular times, schedule SI sessions

    E-Print Network [OSTI]

    Kasman, Alex

    questions on a real exam. This increases student interest in and relevancy of SI rapidly. 17. Attach an SI promotional page (or sticky note) encouraging students to go to SI to student exams1 Things to do early in the semester 1. Allow your SI Leader surveys class for the most popular

  5. Low-Temperature, Strong SiO2-SiO2 Covalent Wafer Bonding for IIIV Compound Semiconductors-to-Silicon Photonic

    E-Print Network [OSTI]

    Bowers, John

    required temperature for strong covalent bond for- mation and greater diffusion efficiency of gasLow-Temperature, Strong SiO2-SiO2 Covalent Wafer Bonding for III­V Compound Semiconductors-temperature process for covalent bonding of thermal SiO2 to plasma-enhanced chemical vapor deposited (PECVD) SiO2

  6. Scale Up of Si/Si0.8GE0.2 and B4C/B9C Superlattices for Harvesting...

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

    Scale Up of SiSi0.8GE0.2 and B4CB9C Superlattices for Harvesting of Waste Heat in Diesel Engines Scale Up of SiSi0.8GE0.2 and B4CB9C Superlattices for Harvesting of Waste Heat...

  7. The role of straining and morphology in thermal conductivity of a set of SiGe superlattices and biomimetic SiGe nanocomposites

    E-Print Network [OSTI]

    Tomar, Vikas

    The role of straining and morphology in thermal conductivity of a set of Si­Ge superlattices and biomimetic Si­Ge nanocomposites This article has been downloaded from IOPscience. Please scroll down to see and morphology in thermal conductivity of a set of Si­Ge superlattices and biomimetic Si­Ge nanocomposites Vikas

  8. Electromagnetic dissociation of relativistic {sup 28}Si by nucleon emission

    SciTech Connect (OSTI)

    Sonnadara, U.J.

    1992-12-01T23:59:59.000Z

    A detailed study of the electromagnetic dissociation of {sup 28}Si by nucleon emission at E{sub lab}/A = 14.6 (GeV/nucleon was carried out with {sup 28}Si beams interacting on {sup 208}Pb). {sup 120}Sn. {sup 64}C targets. The measurements apparatus consists of detectors in the target area which measure the energy and charged multiplicity, and a forward spectrometer which measures the position, momentum and energy of the reaction fragments. The exclusive electromagnetic dissociation cross sections for decay channels having multiple nucleons in the final state have been measured which enables the selection of events produced in pure electromagnetic interactions. The measured cross sections agree well with previous measurements obtained for the removal of a few nucleons as well as with measurements on total charge removal cross sections from other experiments. The dependence of the integrated cross sections on the target charge Z{sub T} and the target mass AT confirms that for higher Z targets the excitation is largely electromagnetic. Direct measurements of the excitation energy for the electromagnetic dissociation of {sup 28}Si {yields} p+{sup 27}Al and {sup 28}Si {yields} n+{sup 27}Si have been obtained through a calculation of the invariant mass in kinematically, reconstructed events. The excitation energy spectrum for all targets peak near the isovector giant dipole resonance in {sup 28}Si. These distributions are well reproduced by combining the photon spectrum calculated using the Weizsaecker-Williams approximation with the experimental data on the photonuclear {sup 28}Si({sub {gamma},p}){sup 27}Al and {sup 28}Si({sub {gamma},n}){sup 27}Si. The possibilities of observing double giant dipole resonance excitations in {sup 28}Si have been investigated with cross section measurements as well as with excitation energy reconstruction.

  9. Electromagnetic dissociation of relativistic [sup 28]Si by nucleon emission

    SciTech Connect (OSTI)

    Sonnadara, U.J.

    1992-12-01T23:59:59.000Z

    A detailed study of the electromagnetic dissociation of [sup 28]Si by nucleon emission at E[sub lab]/A = 14.6 (GeV/nucleon was carried out with [sup 28]Si beams interacting on [sup 208]Pb). [sup 120]Sn. [sup 64]C targets. The measurements apparatus consists of detectors in the target area which measure the energy and charged multiplicity, and a forward spectrometer which measures the position, momentum and energy of the reaction fragments. The exclusive electromagnetic dissociation cross sections for decay channels having multiple nucleons in the final state have been measured which enables the selection of events produced in pure electromagnetic interactions. The measured cross sections agree well with previous measurements obtained for the removal of a few nucleons as well as with measurements on total charge removal cross sections from other experiments. The dependence of the integrated cross sections on the target charge Z[sub T] and the target mass AT confirms that for higher Z targets the excitation is largely electromagnetic. Direct measurements of the excitation energy for the electromagnetic dissociation of [sup 28]Si [yields] p+[sup 27]Al and [sup 28]Si [yields] n+[sup 27]Si have been obtained through a calculation of the invariant mass in kinematically, reconstructed events. The excitation energy spectrum for all targets peak near the isovector giant dipole resonance in [sup 28]Si. These distributions are well reproduced by combining the photon spectrum calculated using the Weizsaecker-Williams approximation with the experimental data on the photonuclear [sup 28]Si([sub [gamma],p])[sup 27]Al and [sup 28]Si([sub [gamma],n])[sup 27]Si. The possibilities of observing double giant dipole resonance excitations in [sup 28]Si have been investigated with cross section measurements as well as with excitation energy reconstruction.

  10. 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...

  11. More stable hybrid organic solar cells deposited on amorphous Si electron transfer layer

    SciTech Connect (OSTI)

    Samiee, Mehran; Modtland, Brian; Dalal, Vikram L., E-mail: vdalal@iastate.edu [Iowa State University, Dept. of Electrical and Computer Engineering, Ames, Iowa 50011 (United States); Aidarkhanov, Damir [Nazarbayev University, Astana (Kazakhstan)

    2014-05-26T23:59:59.000Z

    We report on defect densities, performance, and stability of organic/inorganic hybrid solar cells produced using n-doped inorganic amorphous silicon-carbide layers as the electron transport layer (ETL). The organic material was poly-3-hexyl-thiophene (P3HT) and heterojunction was formed using phenyl-C{sub 71}-Butyric-Acid-Methyl Ester (PCBM). For comparison, inverted solar cells fabricated using Cs{sub 2}CO{sub 3} as ETL were fabricated. Defect densities and subgap quantum efficiency curves were found to be nearly identical for both types of cells. The cells were subjected to 2xsun illumination and it was found that the cells produced using doped a-Si as ETL were much more stable than the cells produced using Cs{sub 2}CO{sub 3}.

  12. Corrosion resistant coatings for SiC and Si{sub 3}N{sub 4} ceramics

    SciTech Connect (OSTI)

    Nguyen Thierry; Shaokai Yang; J.J. Brown

    1998-09-01T23:59:59.000Z

    It is the goal of this program to (1) develop coatings for SiC and Si{sub 3}N{sub 4} that will enhance their performance as heat exchangers under coal combustion conditions and (2) to conduct an in-depth evaluation of the cause and severity of ceramic heat exchanger deterioration and failure under coal combustion conditions.

  13. Size Effect of SiC Particle on Microstructures and Mechanical Properties of SiCp/Al Composites

    E-Print Network [OSTI]

    Qin, Qinghua

    Cp/Al composites were fabricated using aluminum alloy ZL101 as the matrix material, and SiC particles respectively. The results show that the SiC particles can distribute uniformly in the aluminum matrix using matrix or reinforced materials [1-5]. They are promising materials for aerospace, automotive, thermal

  14. Focused ion beam micromilling of GaN and related substrate materials ,,sapphire, SiC, and Si...

    E-Print Network [OSTI]

    Steckl, Andrew J.

    Focused ion beam micromilling of GaN and related substrate materials ,,sapphire, SiC, and Si... A. In addition, we report similar results for materials currently utilized as substrates for GaN growth. II-0030 Received 15 October 1998; accepted 18 December 1998 Micromilling of GaN films has been obtained using a Ga

  15. Transportation System Concept of Operations

    SciTech Connect (OSTI)

    N. Slater-Thompson

    2006-08-16T23:59:59.000Z

    The Nuclear Waste Policy Act of 1982 (NWPA), as amended, authorized the DOE to develop and manage a Federal system for the disposal of SNF and HLW. OCRWM was created to manage acceptance and disposal of SNF and HLW in a manner that protects public health, safety, and the environment; enhances national and energy security; and merits public confidence. This responsibility includes managing the transportation of SNF and HLW from origin sites to the Repository for disposal. The Transportation System Concept of Operations is the core high-level OCRWM document written to describe the Transportation System integrated design and present the vision, mission, and goals for Transportation System operations. By defining the functions, processes, and critical interfaces of this system early in the system development phase, programmatic risks are minimized, system costs are contained, and system operations are better managed, safer, and more secure. This document also facilitates discussions and understanding among parties responsible for the design, development, and operation of the Transportation System. Such understanding is important for the timely development of system requirements and identification of system interfaces. Information provided in the Transportation System Concept of Operations includes: the functions and key components of the Transportation System; system component interactions; flows of information within the system; the general operating sequences; and the internal and external factors affecting transportation operations. The Transportation System Concept of Operations reflects OCRWM's overall waste management system policies and mission objectives, and as such provides a description of the preferred state of system operation. The description of general Transportation System operating functions in the Transportation System Concept of Operations is the first step in the OCRWM systems engineering process, establishing the starting point for the lower level descriptions. of subsystems and components, and the Transportation System Requirements Document. Other program and system documents, plans, instructions, and detailed designs will be consistent with and informed by the Transportation System Concept of Operations. The Transportation System Concept of Operations is a living document, enduring throughout the OCRWM systems engineering lifecycle. It will undergo formal approval and controlled revisions as appropriate while the Transportation System matures. Revisions will take into account new policy decisions, new information available through system modeling, engineering investigations, technical analyses and tests, and the introduction of new technologies that can demonstrably improve system performance.

  16. Hydrogen transport membranes

    DOE Patents [OSTI]

    Mundschau, Michael V.

    2005-05-31T23:59:59.000Z

    Composite hydrogen transport membranes, which are used for extraction of hydrogen from gas mixtures are provided. Methods are described for supporting metals and metal alloys which have high hydrogen permeability, but which are either too thin to be self supporting, too weak to resist differential pressures across the membrane, or which become embrittled by hydrogen. Support materials are chosen to be lattice matched to the metals and metal alloys. Preferred metals with high permeability for hydrogen include vanadium, niobium, tantalum, zirconium, palladium, and alloys thereof. Hydrogen-permeable membranes include those in which the pores of a porous support matrix are blocked by hydrogen-permeable metals and metal alloys, those in which the pores of a porous metal matrix are blocked with materials which make the membrane impervious to gases other than hydrogen, and cermets fabricated by sintering powders of metals with powders of lattice-matched ceramic.

  17. Damage Profiles and Ion Distribution in Pt-irradiated SiC. |...

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

    Damage Profiles and Ion Distribution in Pt-irradiated SiC. Damage Profiles and Ion Distribution in Pt-irradiated SiC. Abstract: Single crystalline 6H-SiC samples were irradiated at...

  18. Electronic Origin For The Phase Transition From Amorphous LixSi...

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

    Li15Si4 . Abstract: Silicon has been widely explored as an anode material for lithium ion battery. Upon lithiation, silicon transforms to amorphous LixSi (a-LixSi) via...

  19. Co-doped Anatase TiO Heteroepitaxy on Si(001). | EMSL

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

    beam epitaxy (OPA-MBE) on Si(001) for evaluation as a potential dilute magnetic semiconductor material suitable for Si-based spintronic devices. Epitaxial growth on Si(001)...

  20. Substrate engineering for monolithic integration of III-V semiconductors with Si CMOS technology

    E-Print Network [OSTI]

    Dohrman, Carl Lawrence

    2008-01-01T23:59:59.000Z

    Ge virtual substrates, fabricated using Si1-xGex-.Ge, compositionally graded buffers, enable the epitaxial growth of device-quality GaAs on Si substrates, but monolithic integration of III-V semiconductors with Si CMOS ...

  1. Strained Silicon on Silicon by Wafer Bonding and Layer Transfer from Relaxed SiGe Buffer

    E-Print Network [OSTI]

    Isaacson, David M.

    We report the creation of strained silicon on silicon (SSOS) substrate technology. The method uses a relaxed SiGe buffer as a template for inducing tensile strain in a Si layer, which is then bonded to another Si handle ...

  2. a-si solar cells: Topics by E-print Network

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

    for the development of amorphous Si solar cells Seung May 2010 Keywords: a-Si:H Thin film Si solar cell Spectroscopic ellipsometry (SE) a b s t r a c t We Park, Byungwoo...

  3. a-si solar cell: Topics by E-print Network

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

    for the development of amorphous Si solar cells Seung May 2010 Keywords: a-Si:H Thin film Si solar cell Spectroscopic ellipsometry (SE) a b s t r a c t We Park, Byungwoo...

  4. The origin of strength limiting defects in a toughened SiC (hexology SX-SiC)

    SciTech Connect (OSTI)

    Srinivasan, G.V.; Gibson, J.; Lau, S.K. [Carborundum Company, Niagara Falls, NY (United States)] [and others

    1996-12-31T23:59:59.000Z

    HEXOLOY{reg_sign} SX-SiC, sintered with yttrium, and aluminum containing compounds has higher toughness and strength than {alpha}-SiC, sintered with boron and carbon (HEXOLOY SA-SiC). The room temperature fracture toughness, and strength in uniaxial tension and flexure were determined. The strength limiting defects were identified. The composition of the strength limiting defects were analyzed by elemental mapping with Scanning Auger Electron Microscopy and Secondary Ion Mass Spectrometry. The origination of such defects are discussed. The fracture mirror parameter was determined from analysis of tensile specimens fracture surfaces. The experimentally determined fracture mirror parameter is compared with the predicted value for SX-SiC and {alpha}-SiC. The local stress state at the vicinity of the defects are discussed.

  5. 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.

  6. Silver (Ag) Transport Mechanisms in TRISO coated particles: A Critical Review

    SciTech Connect (OSTI)

    I J van Rooyen; J H Neethling; J A A Engelbrecht; P M van Rooyen; G Strydom

    2012-10-01T23:59:59.000Z

    Transport of 110mAg in the intact SiC layer of TRISO coated particles has been studied for approximately 30 years without arriving at a satisfactory explanation of the transport mechanism. In this paper the possible mechanisms postulated in previous experimental studies, both in-reactor and out-of reactor research environment studies are critically reviewed and of particular interest are relevance to very high temperature gas reactor operating and accident conditions. Among the factors thought to influence Ag transport are grain boundary stoichiometry, SiC grain size and shape, the presence of free silicon, nano-cracks, thermal decomposition, palladium attack, transmutation products, layer thinning and coated particle shape. Additionally new insight to nature and location of fission products has been gained via recent post irradiation electron microscopy examination of TRISO coated particles from the DOE’s fuel development program. The combined effect of critical review and new analyses indicates a direction for investigating possible the Ag transport mechanism including the confidence level with which these mechanisms may be experimentally verified.

  7. Silver (Ag) Transport Mechanisms in TRISO Coated Particles: A Critical Review

    SciTech Connect (OSTI)

    IJ van Rooyen; ML Dunzik-Gougar; PM van Rooyen

    2014-05-01T23:59:59.000Z

    Transport of 110mAg in the intact SiC layer of TRISO coated particles has been studied for approximately 30 years without arriving at a satisfactory explanation of the transport mechanism. In this paper the possible mechanisms postulated in previous experimental studies, both in-reactor and out-of reactor research environment studies are critically reviewed and of particular interest are relevance to very high temperature gas reactor operating and accident conditions. Among the factors thought to influence Ag transport are grain boundary stoichiometry, SiC grain size and shape, the presence of free silicon, nano-cracks, thermal decomposition, palladium attack, transmutation products, layer thinning and coated particle shape. Additionally new insight to nature and location of fission products has been gained via recent post irradiation electron microscopy examination of TRISO coated particles from the DOE’s fuel development program. The combined effect of critical review and new analyses indicates a direction for investigating possible the Ag transport mechanism including the confidence level with which these mechanisms may be experimentally verified.

  8. Atomic geometry of mixed Ge-Si dimers in the initial-stage growth of Ge on Si,,001...2 1 X. Chen* and D. K. Saldin

    E-Print Network [OSTI]

    Saldin, Dilano

    Atomic geometry of mixed Ge-Si dimers in the initial-stage growth of Ge on Si,,001...2 1 X. Chen quantitatively the geometry of mixed Ge-Si dimers on a single domain Si 001 2 1 surface by azimuthal scanning core-level photoelectron diffraction. By analyzing Ge 3d diffraction patterns from Ge/Si 001 at 0.1 ML

  9. Comparison of luminescent efficiency of InGaAs quantum well structures grown on Si, GaAs, Ge, and SiGe virtual substrate

    E-Print Network [OSTI]

    , and SiGe virtual substrate V. K. Yang, S. M. Ting, M. E. Groenert, M. T. Bulsara, M. T. Currie, C. W efficiency of InGaAs quantum wells on Si via SiGe interlayers, identical In0.2Ga0.8As quantum well structures metalorganic vapor deposition system. The substrates used include GaAs, Si, Ge, and SiGe virtual substrates

  10. 22nd Annual Transportation Research Conference

    E-Print Network [OSTI]

    Minnesota, University of

    22nd Annual Transportation Research Conference May 24-25, 2011 Crowne Plaza St. Paul Riverfront for Transportation Studies 22nd Annual Transportation Research Conference Welcome to the Conference The University of Minnesota's Center for Transportation Studies is pleased to present its 22nd Annual Transportation Research

  11. Information House Committee on Transportation

    E-Print Network [OSTI]

    . The energy efficiency and environmental advantage of rail over trucks are well established in terms Transportation Institute Page 2 MULTIMODAL FREIGHT Texas has a well developed and efficient multimodal, or more than $690 billion. Railroads transport more than a third of the tonmiles for freight valued

  12. Radioactive Material Transportation Practices Manual

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2008-06-04T23:59:59.000Z

    This Manual establishes standard transportation practices for the Department of Energy, including National Nuclear Security Administration to use in planning and executing offsite shipments of radioactive materials and waste. The revision reflects ongoing collaboration of DOE and outside organizations on the transportation of radioactive material and waste. Cancels DOE M 460.2-1.

  13. Road Weather and Transportation Systems

    E-Print Network [OSTI]

    Bertini, Robert L.

    Road Weather and Transportation Systems Rhonda Young, P.E., PhD Associate Professor Dept. of Civil & Arch. Engineering Portland State University April 18, 2014 #12;Engineering Perspective of Road Weather · How does weather impact transportation systems? · As engineers, is there anything we can do

  14. 2030 Transportation and Mobility Plan

    E-Print Network [OSTI]

    Bi-State Metropolitan Planning Organization

    2006-08-11T23:59:59.000Z

    The Bi-State MPO 2030 T RANSPORTATION A N D MOBILITY PLAN Transport t at t i i on Invest t ment t s f f... 2030 Transportation and Mobility Plan Prepared by: The Bi-State MPO Staff In cooperation with: The Cities and Towns of Alma Arkoma Barling Bonanza Fort Smith Greenwood Kibler Lavaca Moffett Muldrow Pocola Roland Rudy Spiro...

  15. San Angelo Metropolitan Transportation Plan

    E-Print Network [OSTI]

    San Angelo Metropolitan Planning Organization

    2009-11-16T23:59:59.000Z

    : City of San Angelo Tom Green County Concho Valley Transit District Texas Department of Transportation U.S. Department of Transportation Federal Highway Administration Federal Transit Administration Approved... Director Concho Valley Council of Governments * Elected Non-Voting Members Drew Darby* State Representative, State of Texas Robert Duncan* State Senator, State of Texas Peggy Thurin Statewide Planning Coordinator...

  16. Contaminant Transport in Hydrogeologic Systems 

    E-Print Network [OSTI]

    Chin, C.; Redden, D. L.

    1981-01-01T23:59:59.000Z

    , the evaluation of dispersivity under field conditions is a costly and time consuming job. The process of transporting a specific conservative ion species in an aquifer is analogous to the transport of heat in the system. Because of this analogy, the original...

  17. CREATING A BALANCED TRANSPORTATION SYSTEM

    E-Print Network [OSTI]

    Bertini, Robert L.

    think we need to make people aware that our traffic concepts of today are not sustainable) Orange .Transport . Architecture .Water management . #12;5 The Netherlands (as it is) Orange .Transport . Architecture .Water management . #12;6 United States Oregon Portland The Netherlands Utrecht Founded 1776 1859

  18. 7, 38373857, 2007 Global transports

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    and 180 are still transporting into soil and water. It is found that lighter PCBs have more long range international concern with identifying and managing environmentally persistent substances that are bothACPD 7, 3837­3857, 2007 Global transports and budgets of PCBs P. Huang et al. Title Page Abstract

  19. Transportation Research Board Conference January 10, 2005 Using Custom Transportation Data

    E-Print Network [OSTI]

    Bertini, Robert L.

    Transportation Research Board Conference January 10, 2005 Using Custom Transportation Data Collection Software with Handheld Computers for Education, Research, and Practice Transportation Research, Andrew Byrd, Michael Rose, Tarek Abou El-Seoud #12;Transportation Research Board Conference January 10

  20. Isothermal nitridation kinetics of TiSi{sub 2} powders

    SciTech Connect (OSTI)

    Roger, J., E-mail: roger@lcts.u-bordeaux1.fr; Maillé, L.; Dourges, M.A.

    2014-04-01T23:59:59.000Z

    The aim of the present work is to determine the kinetics of reaction between TiSi{sub 2} powder and gaseous nitrogen. Isothermal nitridation of TiSi{sub 2} powders with fine (1.4 µm) and medium (4.5 µm) particle size has been studied in pure nitrogen atmosphere from 1000 to 1200 °C for duration up to 50 h. The isothermal nitridation kinetics of TiSi{sub 2} powders were investigated by thermogravimetry. The nitridation rate strongly depends on the particle size and temperature. Smaller size particle exhibits higher nitridation rate due to its larger surface area. The conversion process is complex with nucleation and growth of TiN at the surface of the grain and Si{sub 3}N{sub 4} inside the grain promoted by the Kirkendall effect with an influence of the volume increase. - Graphical abstract: Backscattered electrons image of a transverse TiSi{sub 2} grain nitrurated at 1100 °C for 50 h. - Highlights: • Influence of grain size on TiSi{sub 2} powder nitridation. • Influence of temperature on TiSi{sub 2} powder nitridation. • Experimental measurements of the nitridation kinetics. • An explanation of the nitridation mechanism.

  1. Excess vacancies in high energy ion implanted SiGe

    SciTech Connect (OSTI)

    Koegler, R.; Muecklich, A.; Skorupa, W.; Peeva, A.; Kuznetsov, A. Yu.; Christensen, J. S.; Svensson, B. G. [Forschungszentrum Rossendorf, PF 510119, D-01314 Dresden (Germany); Institute of Solid State Physics BAS, Boulevard Tzarigradsko Chaussee 72, 1784 Sofia (Bulgaria); Deparment of Physics, University of Oslo, P.O. Box 1048 Blindern, NO-0316 Oslo (Norway); Center for Materials Science and Nanotechnology, University of Oslo, P.O. Box 1048 Blindern, NO-0316 Oslo (Norway)

    2007-02-01T23:59:59.000Z

    Excess vacancies generated by high energy implantation with 1.2 MeV Si{sup +} and 2 MeV Ge{sup +} ions in SiGe were investigated after rapid thermal annealing at 900 degree sign C. Excess vacancies were probed by decoration with Cu and measuring the Cu profile by secondary ion mass spectrometry. Cross section transmission electron microscopy of cleaved specimen enabled to visualize nanocavities resulting from agglomeration of excess vacancies. The ion-induced damage in SiGe increases with increasing Ge fraction of the alloy. The amorphization threshold decreases and the extension of a buried amorphous layer increases for given implantation and annealing conditions. In contrast to ballistic simulations of excess defect generation where perfect local self-annihilation is assumed the concentrations of excess vacancies and excess interstitials in SiGe increase with increasing Ge fraction. The main contribution to the high excess vacancy concentration in SiGe results from the inefficient recombination of vacancies and interstitials. The widely used +1 model describing the ion-induced damage in Si is not valid for SiGe.

  2. Atomic-Level Computer Simulation of SiC: Defect Accumulation...

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

    Atomic-Level Computer Simulation of SiC: Defect Accumulation, Mechanical Properties and Defect Recovery. Atomic-Level Computer Simulation of SiC: Defect Accumulation, Mechanical...

  3. Development of an SI DI Ethanol Optimized Flex Fuel Engine Using...

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

    Development of an SI DI Ethanol Optimized Flex Fuel Engine Using Advanced Valvetrain Development of an SI DI Ethanol Optimized Flex Fuel Engine Using Advanced Valvetrain...

  4. Realising wide bandgap P-SiC-emitter lateral heterojunction bipolar transistors with low

    E-Print Network [OSTI]

    Kumar, M. Jagadesh

    semiconductors such as InGaP/GaAs or AlGaAs/GaAs are available, HBTs based on SiC/Si are attractive because

  5. Deep level defects in proton radiated GaAs grown on metamorphic SiGe/Si substrates

    SciTech Connect (OSTI)

    Gonzalez, M.; Andre, C. L.; Walters, R. J.; Messenger, S. R.; Warner, J. H.; Lorentzen, J. R.; Pitera, A. J.; Fitzgerald, E. A.; Ringel, S. A. [Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States); U.S. Naval Research Laboratory, Code 6818, Washington, DC 20375 (United States); Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Department of Electrical and Computer Engineering, Ohio State University, Columbus, Ohio 43210 (United States)

    2006-08-01T23:59:59.000Z

    The effect of 2 MeV proton radiation on the introduction of deep levels in GaAs grown on compositionally graded SiGe/Si substrates was investigated using deep level transient spectroscopy (DLTS). Systematic comparisons were made with identical layers grown on both GaAs and Ge substrates to directly assess the influence of threading dislocations on radiation-related deep levels for both n-type and p-type GaAs. DLTS revealed that for p{sup +}n structures, proton irradiation generates electron traps at E{sub c}-0.14 eV, E{sub c}-0.25 eV, E{sub c}-0.54 eV, and E{sub c}-0.72 eV in the n-GaAs base, and, for n{sup +}p structures, radiation-induced hole traps appear at E{sub v}+0.18 eV, E{sub v}+0.23 eV, E{sub v}+0.27 eV, and E{sub v}+0.77 eV in the p-type GaAs base, irrespective of substrate choice for both polarities. The primary influence of substituting SiGe/Si substrates for conventional GaAs and Ge substrates is on the introduction rates of the individual traps as a function of proton radiation fluence. Substantially reduced concentrations are found for each radiation-induced hole trap observed in p-type GaAs, as well as for the E{sub c}-0.54 eV trap in n-GaAs for samples on SiGe/Si, as a function of proton fluence. Calculated trap introduction rates reveal reductions by as much as {approx}40% for certain hole traps in p-GaAs grown on SiGe/Si. This increased radiation tolerance for GaAs grown on SiGe/Si is attributed to interactions between the low density ({approx}10{sup 6} cm{sup -2}) of residual dislocations within the metamorphic GaAs/SiGe/Si structure and the radiation-induced point defects. Nevertheless, the fact that the impact of dislocations on radiation tolerance is far more dramatic for n{sup +}p GaAs structures compared to p{sup +}n structures, may have implications on future III-V/Si space solar cell design optimization, since end-of-life versus beginning-of-life differences are critical factors for power profiling in high radiation environments.

  6. Antibody binding to p-Si using LANL SAM chemistry

    SciTech Connect (OSTI)

    Anderson, Aaron S [Los Alamos National Laboratory

    2010-12-06T23:59:59.000Z

    This NMSBA-sponsored project involves the attachment of antibodies to polymeric silicon (p-Si) surfaces, with the ultimate goal of attaching antibodies to nanowires for Vista Therapeutics, Inc. (Santa Fe, NM). This presentation describes the functionalization of p-Si surfaces. the activation of terminal carboxylates on these surfaces, the conjugation of antibodies, and the analyses undertaken at each step. The results of this work show that antibody conjugation is possible on p-Si coatings using the well-known EDC/NHS activation chemistry.

  7. Efficient tunable luminescence of SiGe alloy sheet polymers

    SciTech Connect (OSTI)

    Vogg, G.; Meyer, A. J.-P.; Miesner, C.; Brandt, M. S.; Stutzmann, M.

    2001-06-18T23:59:59.000Z

    Crystalline SiGe alloy sheet polymers were topotactically prepared from epitaxially grown calcium germanosilicide Ca(Si{sub 1{minus}x}Ge{sub x}){sub 2} precursor films in the whole composition range. These polygermanosilynes are found to be a well-defined mixture of the known siloxene and polygermyne sheet polymers with the OH groups exclusively bonded to silicon. The optical properties determined by photoluminescence and optical reflection measurements identify the mixed SiGe sheet polymers as direct semiconductors with efficient luminescence tunable in the energy range between 2.4 and 1.3 eV. {copyright} 2001 American Institute of Physics.

  8. Multi-Path Transportation Futures Study - Lessons for the Transportati...

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

    Multi-Path Transportation Futures Study - Lessons for the Transportation Energy Futures Study Multi-Path Transportation Futures Study - Lessons for the Transportation Energy...

  9. SiGe HBT linear-in-dB high dynamic range RF envelope detectors and wideband high linearity amplifiers

    E-Print Network [OSTI]

    Pan, Hsuan-yu

    2010-01-01T23:59:59.000Z

    1.1 SiGe BiCMOS Technology . . . . . . .A Linear-in-dB SiGe HBT Wideband High Dynamic Range RFpower dissapation trade-off between Si BJTs and SiGe HBTs [

  10. Transportation Center Seminar Series presents..... Marshall Lindsey

    E-Print Network [OSTI]

    Bustamante, Fabián E.

    Transportation Center Seminar Series presents..... Marshall Lindsey Transportation Center for reducing automobile use. Bio: Marshall Lindsey has a BS in Chemical Engineering from Case Western emissions associated with transportation in Chicago. In addition to his academic pursuits, Marshall has

  11. Molecular Weight & Energy Transport 7 September 2011

    E-Print Network [OSTI]

    Militzer, Burkhard

    't transport the bulk of the energy in the sun. #12;Molecular Weight & Energy Transport 7 September 2011 Goals · Review mean molecular weight this intuitively before looking back at your quantitative results. #12;molecular weight & energy transport 2 Energy

  12. PORTLAND STATE UNIVERSITY CENTER FOR TRANSPORTATION STUDIES

    E-Print Network [OSTI]

    Bertini, Robert L.

    PORTLAND STATE UNIVERSITY CENTER FOR TRANSPORTATION STUDIES DEPARTMENT OF CIVIL & ENVIRONMENTAL ENGINEERING SCHOOL OF URBAN STUDIES AND PLANNING First Annual Portland Metropolitan Region Transportation System Performance Report September 8, 2004 #12;2First Annual Portland Metropolitan Region Transportation

  13. Report on the 1961 TRANSPORTATION RESEARCH--------.. . -. .

    E-Print Network [OSTI]

    ) ) ) Report on the 1961 TRANSPORTATION RESEARCH--------.. . -. . AND SERVICE ACTIVITIES IC C Negotiations with carriers ..·..... Resea rch activities ·...........·... Transportation Section staff resea rch . Transportation rate indexes .... Fish meal, scrap, and solublf's information

  14. Parking & Transportation Department RESIDENT -PERSONAL INFORMATION

    E-Print Network [OSTI]

    Oliver, Douglas L.

    Parking & Transportation Department RESIDENT - PERSONAL INFORMATION Date know if you are interested in: Public Transportation Car Pool Van Pool _____________________________________________________________________________________ Please be sure to contact the Parking & Transportation Department with any changes to your information, i

  15. It's About Time: Investing in Transportation to

    E-Print Network [OSTI]

    MARCH 2011 It's About Time: Investing in Transportation to Keep Texas Economically Competitive #12 of Contents Preface 1 The Challenge Facing Texans 3 Texas Transportation Action Principles 6 Texas' Deteriorating Transportation System: Background and Measurement 8 Baseline Scenario: Unacceptable Conditions

  16. Public School Transportation National and Regional

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    Public School Transportation National and Regional Perspectives: An Update Presented to Education University #12;Table of Contents I. Current Transportation Funding Policies ..................................................................................................................................1 B. Transportation Funding Options Used by States

  17. Baton Rouge Metropolitan Transportation Plan Update

    E-Print Network [OSTI]

    Capital Region Planning Commission

    (028) SUBMITTED TO: LOUISIANA DEPARTMENT OF TRANSPORTATION AND DEVELOPMENT SUBMITTED BY: IN ASSOCIATION WITH: & FINAL Metropolitan Transportation Plan Update Baton Rouge, LA... ............................189? X. APPENDIX .........................................................................................................................195? ? Metropolitan Transportation Plan Update...

  18. Anomalous transport through porous and fractured media

    E-Print Network [OSTI]

    Kang, Peter Kyungchul

    2014-01-01T23:59:59.000Z

    Anomalous transport, understood as the nonlinear scaling with time of the mean square displacement of transported particles, is observed in many physical processes, including contaminant transport through porous and fractured ...

  19. Biofuel Feedstock Inter-Island Transportation

    E-Print Network [OSTI]

    Biofuel Feedstock Inter-Island Transportation Prepared for the U.S. Department of Energy Office ........................................................................... 11 Options for liquid biofuel feedstock transport ............................................................................. agency thereof. #12;A Comparison of Hawaii's Inter-Island Maritime Transportation of Solid Versus Liquid

  20. Fuel Cells for Transportation | Department of Energy

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

    DOE R&D Activities Fuel Cells for Transportation Fuel Cells for Transportation Photo of Ford Focus fuel cell car in front of windmills The transportation sector is the single...