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Sample records for frv si transport

  1. FRV SI Transport Solar LP | Open Energy Information

    Open Energy Info (EERE)

    SI Transport Solar LP Jump to: navigation, search Name: FRV SI Transport Solar LP Place: Arizona References: EIA Form EIA-861 Final Data File for 2010 - File220101 EIA Form 861...

  2. FRV USA formerly Fotowatio Renewable Ventures LLC | Open Energy...

    Open Energy Info (EERE)

    USA formerly Fotowatio Renewable Ventures LLC Jump to: navigation, search Name: FRV USA (formerly Fotowatio Renewable Ventures LLC) Place: San Francisco, California Zip: 94104...

  3. FRV formerly Fotowatio Energia Solar SL | Open Energy Information

    Open Energy Info (EERE)

    formerly Fotowatio Energia Solar SL Jump to: navigation, search Name: FRV (formerly Fotowatio Energia Solar SL) Place: Madrid, Spain Zip: 28010 Sector: Renewable Energy Product:...

  4. Temperature dependent transport characteristics of graphene/n-Si diodes

    SciTech Connect (OSTI)

    Parui, S.; Ruiter, R.; Zomer, P. J.; Wojtaszek, M.; Wees, B. J. van; Banerjee, T.

    2014-12-28

    Realizing an optimal Schottky interface of graphene on Si is challenging, as the electrical transport strongly depends on the graphene quality and the fabrication processes. Such interfaces are of increasing research interest for integration in diverse electronic devices as they are thermally and chemically stable in all environments, unlike standard metal/semiconductor interfaces. We fabricate such interfaces with n-type Si at ambient conditions and find their electrical characteristics to be highly rectifying, with minimal reverse leakage current (<10{sup ?10}?A) and rectification of more than 10{sup 6}. We extract Schottky barrier height of 0.69?eV for the exfoliated graphene and 0.83?eV for the CVD graphene devices at room temperature. The temperature dependent electrical characteristics suggest the influence of inhomogeneities at the graphene/n-Si interface. A quantitative analysis of the inhomogeneity in Schottky barrier heights is presented using the potential fluctuation model proposed by Werner and Gttler.

  5. Light absorption and electrical transport in Si:O alloys for photovoltaics

    SciTech Connect (OSTI)

    Mirabella, S.; Crupi, I.; Miritello, M.; Simone, F.; Di Martino, G.; Di Stefano, M. A.; Di Marco, S.; Priolo, F.

    2010-11-15

    Thin films (100-500 nm) of the Si:O alloy have been systematically characterized in the optical absorption and electrical transport behavior, by varying the Si content from 43 up to 100 at. %. Magnetron sputtering or plasma enhanced chemical vapor deposition have been used for the Si:O alloy deposition, followed by annealing up to 1250 deg. C. Boron implantation (30 keV, 3-30x10{sup 14} B/cm{sup 2}) on selected samples was performed to vary the electrical sheet resistance measured by the four-point collinear probe method. Transmittance and reflectance spectra have been extracted and combined to estimate the absorption spectra and the optical band gap, by means of the Tauc analysis. Raman spectroscopy was also employed to follow the amorphous-crystalline (a-c) transition of the Si domains contained in the Si:O films. The optical absorption and the electrical transport of Si:O films can be continuously and independently modulated by acting on different parameters. The light absorption increases (by one decade) with the Si content in the 43-100 at. % range, determining an optical band gap which can be continuously modulated into the 2.6-1.6 eV range, respectively. The a-c phase transition in Si:O films, causing a significant reduction in the absorption coefficient, occurs at increasing temperatures (from 600 to 1100 deg. C) as the Si content decreases. The electrical resistivity of Si:O films can be varied among five decades, being essentially dominated by the number of Si grains and by the doping. Si:O alloys with Si content in the 60-90 at. % range (named oxygen rich silicon films), are proved to join an appealing optical gap with a viable conductivity, being a good candidate for increasing the conversion efficiency of thin-film photovoltaic cell.

  6. Elastic tunneling charge transport mechanisms in silicon quantum dots /SiO{sub 2} thin films and superlattices

    SciTech Connect (OSTI)

    Illera, S. Prades, J. D.; Cirera, A.

    2015-05-07

    The role of different charge transport mechanisms in Si/SiO{sub 2} structures has been studied. A theoretical model based on the Transfer Hamiltonian Formalism has been developed to explain experimental current trends in terms of three different elastic tunneling processes: (1) trap assisted tunneling; (2) transport through an intermediate quantum dot; and (3) direct tunneling between leads. In general, at low fields carrier transport is dominated by the quantum dots whereas, for moderate and high fields, transport through deep traps inherent to the SiO{sub 2} is the most relevant process. Besides, current trends in Si/SiO{sub 2} superlattice structure have been properly reproduced.

  7. Monte Carlo Simulation of Electron Transport in 4H- and 6H-SiC

    SciTech Connect (OSTI)

    Sun, C. C.; You, A. H.; Wong, E. K.

    2010-07-07

    The Monte Carlo (MC) simulation of electron transport properties at high electric field region in 4H- and 6H-SiC are presented. This MC model includes two non-parabolic conduction bands. Based on the material parameters, the electron scattering rates included polar optical phonon scattering, optical phonon scattering and acoustic phonon scattering are evaluated. The electron drift velocity, energy and free flight time are simulated as a function of applied electric field at an impurity concentration of 1x10{sup 18} cm{sup 3} in room temperature. The simulated drift velocity with electric field dependencies is in a good agreement with experimental results found in literature. The saturation velocities for both polytypes are close, but the scattering rates are much more pronounced for 6H-SiC. Our simulation model clearly shows complete electron transport properties in 4H- and 6H-SiC.

  8. Effect of growth temperature on ballistic electron transport through the Au/Si(001) interface

    SciTech Connect (OSTI)

    Eckes, M. W.; Friend, B. E.; Stollenwerk, A. J.

    2014-04-28

    Ballistic electron emission spectroscopy was used to investigate electron transport through Au/Si(001) Schottky diodes grown at 35?C and 22?C. Aside from a decreased Schottky height, this small increase in temperature introduced an energy dependent scattering component, which was absent in the samples grown at 22?C. These differences may be attributed to the increased amount of Au-Si intermixing at the interface. Despite the non-epitaxial nature of the growth technique, strong evidence was found in both sets of samples that indicated the presence of a forward-focused current subject to some degree of parallel momentum conservation at the interface. This evidence was present in all samples grown at 35?C, but was only observed in those samples grown at 22?C when the Au films were 10?nm or thicker. This sensitivity to growth temperature could account for discrepancies in previous studies on Au/Si(001)

  9. Magneto-transport of an electron bilayer system in an undoped Si/SiGe double-quantum-well heterostructure

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

    Laroche, Dominique; Huang, ShiHsien; Nielsen, Erik; Liu, Chee Wee; Li, Jiun -Yun; Lu, Tzu -Ming

    2015-04-08

    We report the design, the fabrication, and the magneto-transport study of an electron bilayer system embedded in an undoped Si/SiGe double-quantum-well heterostructure. Additionally, the combined Hall densities (n Hall ) ranging from 2.6 × 1010 cm-2 to 2.7 × 1011 cm-2 were achieved, yielding a maximal combined Hall mobility (μHall ) of 7.7 × 105 cm2/(V • s) at the highest density. Simultaneous electron population of both quantum wells is clearly observed through a Hall mobility drop as the Hall density is increased to nHall > 3.3 × 1010 cm-2, consistent with Schrödinger-Poisson simulations. Furthermore, the integer and fractional quantummore » Hall effects are observed in the device, and single-layer behavior is observed when both layers have comparable densities, either due to spontaneous interlayer coherence or to the symmetric-antisymmetric gap.« less

  10. The spin-dependent transport of Co-encapsulated Si nanotubes contacted with Cu electrodes

    SciTech Connect (OSTI)

    Guo, Yan-Dong; Yan, Xiao-Hong; Xiao, Yang

    2014-02-10

    Unlike carbon nanotubes, silicon ones are hard to form. However, they could be stabilized by metal-encapsulation. Using first-principles calculations, we investigate the spin-dependent electronic transport of Co-encapsulated Si nanotubes, which are contacted with Cu electrodes. For the finite tubes, as the tube-length increases, the transmission changes from spin-unpolarized to spin-polarized. Further analysis shows that, not only the screening of electrodes on Co's magnetism but also the spin-asymmetric Co-Co interactions are the physical mechanisms. As Cu and Si are the fundamental elements in semiconductor industry, our results may throw light on the development of silicon-based spintronic devices.

  11. Characterization of carrier transport properties in strained crystalline Si wall-like structures in the quasi-quantum regime

    SciTech Connect (OSTI)

    Mayberry, C. S.; Huang, Danhong Kouhestani, C.; Balakrishnan, G.; Islam, N.; Brueck, S. R. J.; Sharma, A. K.

    2015-10-07

    We report the transport characteristics of both electrons and holes through narrow constricted crystalline Si “wall-like” long-channels that were surrounded by a thermally grown SiO{sub 2} layer. The strained buffering depth inside the Si region (due to Si/SiO{sub 2} interfacial lattice mismatch) is where scattering is seen to enhance some modes of the carrier-lattice interaction, while suppressing others, thereby changing the relative value of the effective masses of both electrons and holes, as compared to bulk Si. In the narrowest wall devices, a considerable increase in conductivity was observed as a result of higher carrier mobilities due to lateral constriction and strain. The strain effects, which include the reversal splitting of light- and heavy-hole bands as well as the decrease of conduction-band effective mass by reduced Si bandgap energy, are formulated in our microscopic model for explaining the experimentally observed enhancements in both conduction- and valence-band mobilities with reduced Si wall thickness. Also, the enhancements of the valence-band and conduction-band mobilities are found to be associated with different aspects of theoretical model.

  12. Formation of BaSi{sub 2} heterojunction solar cells using transparent MoO{sub x} hole transport layers

    SciTech Connect (OSTI)

    Du, W.; Takabe, R.; Baba, M.; Takeuchi, H.; Toko, K.; Hara, K. O.; Usami, N.; Suemasu, T.

    2015-03-23

    Heterojunction solar cells that consist of 15?nm thick molybdenum trioxide (MoO{sub x}, x?transport layer and 600?nm thick unpassivated or passivated n-BaSi{sub 2} layers were demonstrated. Rectifying current-voltage characteristics were observed when the surface of BaSi{sub 2} was exposed to air. When the exposure time was decreased to 1?min, an open circuit voltage of 200?mV and a short circuit current density of 0.5?mA/cm{sup 2} were obtained under AM1.5 illumination. The photocurrent density under a reverse bias voltage of ?1 V reached 25?mA/cm{sup 2}, which demonstrates the significant potential of BaSi{sub 2} for solar cell applications.

  13. Optical and carrier transport properties of graphene oxide based crystalline-Si/organic Schottky junction solar cells

    SciTech Connect (OSTI)

    Khatri, I.; Tang, Z.; Hiate, T.; Liu, Q.; Ishikawa, R.; Ueno, K.; Shirai, H.

    2013-12-21

    We investigated the graphene oxide (GO) based n-type crystalline silicon (c-Si)/conductive poly(ethylene dioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) Schottky junction devices with optical characterization and carrier transport measurement techniques. The optical transmittance in the UV region decreased markedly for the films with increasing the concentration of GO whereas it increased markedly in the visible-infrared regions. Spectroscopic ellipsometry revealed that the ordinary and extraordinary index of refraction increased with increasing the concentration of GO. The hole mobility also increased from 1.14 for pristine film to 1.85 cm{sup 2}/V s for the 1215?wt. % GO modified film with no significant increases of carrier concentration. The highest conductivity was found for a 15?wt. % GO modified PEDOT:PSS film: the c-Si/PEDOT:PSS:GO device using this sample exhibited a relatively high power conversion efficiency of 11.04%. In addition, the insertion of a 23?nm-thick GO thin layer at the c-Si/PEDOT:PSS interface suppressed the carrier recombination efficiency of dark electron and photo-generated hole at the anode, resulting in the increased photovoltaic performance. This study indicates that the GO can be good candidates for hole transporting layer of c-Si/PEDOT:PSS Schottky junction solar cell.

  14. Preparation and electrical transport properties of quasi free standing bilayer graphene on SiC (0001) substrate by H intercalation

    SciTech Connect (OSTI)

    Yu, Cui; Liu, Qingbin; Li, Jia; Lu, Weili; He, Zezhao; Cai, Shujun; Feng, Zhihong

    2014-11-03

    We investigate the temperature dependent electrical transport properties of quasi-free standing bilayer graphene on 4H-SiC (0001) substrate. Three groups of monolayer epitaxial graphene and corresponding quasi-free standing bilayer graphene with different crystal quality and layer number homogeneity are prepared. Raman spectroscopy and atomic-force microscopy are used to obtain their morphologies and layer number, and verify the complete translation of buffer layer into graphene. The highest room temperature mobility reaches 3700 cm{sup 2}/V·s for the quasi-free standing graphene. The scattering mechanism analysis shows that poor crystal quality and layer number inhomogeneity introduce stronger interacting of SiC substrate to the graphene layer and more impurities, which limit the carrier mobility of the quasi-free standing bilayer graphene samples.

  15. Low-Cost Growth of III-V Layers on Si Using Close-Spaced Vapor Transport

    SciTech Connect (OSTI)

    Boucher, Jason W.; Greenaway, Ann L.; Ritenour, Andrew J.; Davis, Allison L.; Bachman, Benjamin F.; Aloni, Shaul; Boettcher, Shannon W.

    2015-06-14

    Close-spaced vapor transport (CSVT) uses solid precursors to deposit material at high rates and with high precursor utilization. The use of solid precursors could significantly reduce the costs associated with III-V photovoltaics, particularly if growth on Si substrates can be demonstrated. We present preliminary results of the growth of GaAs1-xPx with x ≈ 0.3 and 0.6, showing that CSVT can be used to produce III-V-V’ alloys with band gaps suitable for tandem devices. Additionally, we have grown GaAs on Si by first thermally depositing films of Ge and subsequently depositing GaAs by CSVT. Patterning the Ge into islands prevents cracking due to thermal mismatch and is useful for potential tandem structures.

  16. 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. Wu, G. H.; Zhang, H. G.

    2014-06-16

    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.

  17. Electronic transport of titanate heterostructures and their potential as channels on (001) Si

    SciTech Connect (OSTI)

    Kornblum, Lior Jin, Eric N.; Walker, Fred J.; Shoron, Omor; Boucherit, Mohamed; Rajan, Siddharth; Ahn, Charles H.

    2015-09-14

    Perovskite oxides and their heterostructures have demonstrated considerable potential for devices that require high carrier densities. These oxides are typically grown on ceramic substrates that suffer from low thermal conductivity, which limits performance under high currents, and from the limited size of substrates, which precludes large scale integration and processing. We address both of these hurdles by integrating oxide heterostructures with high carrier density 2D electron gases (2DEGs) directly on (001) Si. 2DEGs grown on Si show significant improvement of the high current performance over those grown on oxide substrates, a consequence of the higher thermal conductivity of the substrate. Hall analysis, transmission line measurements, and the conductance technique are employed for a detailed analysis of the carrier density, contact resistance, mobility, and electron drift velocities. Current densities of 10 A/cm are observed at room temperature with 2.9 × 10{sup 14} electrons/cm{sup 2} at a drift velocity exceeding 3.5 × 10{sup 5 }cm/s. These results highlight the promise of oxide 2DEGs integration on Si as channels for high electron density devices.

  18. Imaging carrier and phonon transport in Si using ultrashort optical pulses

    SciTech Connect (OSTI)

    David H. Hurley; O. B. Wright; O. Matsuda; B. E. McCandless; S. Shinde

    2009-01-01

    A series of experiments have been conducted that microscopically image thermal diffusion and surface acoustic phonon propagation within a single crystallite of a polycrystalline Si sample. The experimental approach employs ultrashort optical pulses to generate an electron-hole plasma and a second probe pulse is used to image the evolution of the plasma. By decomposing the signal into a component that varies with delay time and a steady state component that varies with pump modulation frequency, the respective influence of carrier recombination and thermal diffusion are identified. Additionally, the coherent surface acoustic phonon component to the signal is imaged using a Sagnac interferometer to monitor optical phase.

  19. Transport and noise properties of Si nanowire channels with different lengths before and after gamma radiation treatment

    SciTech Connect (OSTI)

    Li, Jing; Vitusevich, Svetlana; Pud, Sergii; Sydoruk, Viktor; Offenhusser, Andreas; Petrychuk, Mykhailo; Danilchenko, Boris

    2013-12-04

    The transport properties of Si nanowire (NW) structures fabricated on the basis of silicon on insulator (SOI) wafers were studied using noise spectroscopy before and after treatment with small doses of gamma radiation. The total resistance obtained from the I-V characteristics of Si NW structures scaled perfectly with length. Normalized flicker noise demonstrated 1/L{sup 2} dependence, which is a characteristic of dominant noise contribution from near-contact regions. The behavior changed to 1/L dependence after a small dose (110{sup 4} Gy) of gamma radiation treatment. Comparison of the random telegraph signal (RTS) noise parameters in the samples with small lengths before and after the treatment revealed a decrease in RTS amplitude and a shift to a lower frequency range after gamma irradiation. These results confirmed that the main changes in the samples were related to strain relaxation near-contact regions. In addition, such treatment resulted in a considerable decrease in the scattering data of device parameters.

  20. 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.; Suslov, A. V.; Mironov, O. A.; Kummer, M.; Känel, H. von

    2014-08-20

    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.

  1. Comparison of carrier transport mechanism under UV/Vis illumination in an AZO photodetector and an AZO/p-Si heterojunction photodiode produced by spray pyrolysis

    SciTech Connect (OSTI)

    Shasti, M.; Mortezaali, A. Dariani, R. S.

    2015-01-14

    In this study, Aluminum doped Zinc Oxide (AZO) layer is deposited on p-type silicon (p-Si) by spray pyrolysis method to fabricate ultraviolet-visible (UV/Vis) photodetector as Al doping process can have positive effect on the photodetector performance. Morphology, crystalline structure, and Al concentration of AZO layer are investigated by SEM, XRD, and EDX. The goal of this study is to analyze the mechanism of carrier transport by means of current-voltage characteristics under UV/Vis illumination in two cases: (a) electrodes connected to the surface of AZO layer and (b) electrodes connected to cross section of heterojunction (AZO/p-Si). Measurements indicate that the AZO/p-Si photodiode exhibits a higher photocurrent and lower photoresponse time under visible illumination with respect to AZO photodetector; while under UV illumination, the above result is inversed. Besides, the internal junction field of AZO/p-Si heterojunction plays an important role on this mechanism.

  2. Intrinsic SiO{sub x}-based unipolar resistive switching memory. II. Thermal effects on charge transport and characterization of multilevel programing

    SciTech Connect (OSTI)

    Chang, Yao-Feng Chen, Ying-Chen; Chen, Yen-Ting; Wang, Yanzhen; Xue, Fei; Zhou, Fei; Lee, Jack C.; Fowler, Burt

    2014-07-28

    Multilevel programing and charge transport characteristics of intrinsic SiO{sub x}-based resistive switching memory are investigated using TaN/SiO{sub x}/n{sup ++}Si (MIS) and TiW/SiO{sub x}/TiW (MIM) device structures. Current transport characteristics of high- and low-resistance states (HRS and LRS) are studied in both device structures during multilevel operation. Analysis of device thermal response demonstrates that the effective electron energy barrier is strongly dependent on the resistance of the programed state, with estimates of 0.1?eV in the LRS and 0.6?eV in the HRS. Linear data fitting and conductance analyses indicate Poole-Frenkel emission or hopping conductance in the low-voltage region, whereas Fowler-Nordheim (F-N) or trap-assisted tunneling (TAT) is indicated at moderate voltage. Characterizations using hopping transport lead to hopping distance estimates of ?1?nm in the LRS for both device structures. Relative permittivity values (?{sub r}) were extracted using the Poole-Frenkel formulism and estimates of local filament temperature, where ?{sub r} values were ?80 in the LRS and ?4 in the HRS, suggesting a strongly polarized medium in the LRS. The onset of F-N tunneling or TAT corresponds to an observed overshoot in the I-V response with an estimated threshold of 1.6??0.2?V, in good agreement with reported electro-luminescence results for LRS devices. Resistive switching is discussed in terms of electrochemical reactions between common SiO{sub 2} defects, and specific defect energy levels are assigned to the dominant transitions in the I-V response. The overshoot response in the LRS is consistent with TAT through either the E?' oxygen vacancy or the hydrogen bridge defect, both of which are reported to have an effective bandgap of 1.7?eV. The SET threshold at ?2.5?V is modeled as hydrogen release from the (Si-H){sub 2} defect to generate the hydrogen bridge, and the RESET transition is modeled as an electrochemical reaction that re-forms (Si

  3. Effect of Mn substitution on the transport properties of co-sputtered Fe{sub 3−x}Mn{sub x}Si epilayers

    SciTech Connect (OSTI)

    Tang, M.; Jin, C.; Bai, H. L.

    2014-11-07

    Motivated by the theoretical calculations that Fe{sub 3−x}Mn{sub x}Si can simultaneously exhibit a high spin polarization with a high Curie temperature to be applied in spintronic devices, and in order to further study the effect of Mn contents on the physical properties of Fe{sub 3−x}Mn{sub x}Si, we have investigated the effect of Mn substitution on the transport properties of epitaxial Fe{sub 3−x}Mn{sub x}Si (0≤x≤1) films systematically. The Fe{sub 3−x}Mn{sub x}Si films were epitaxially grown on MgO(001) plane with 45° rotation. The magnetization for various x shows enhanced irreversibility, implying the antiferromagnetic ordering induced by the substitution of Mn. A metal-semiconductor crossover was observed due to the enhanced disorders of interactions and the local lowering of symmetry induced by the substitution of Mn. The single-domain state in the Fe{sub 3−x}Mn{sub x}Si films leads to twofold symmetric curves of the anisotropic magnetoresistance and planar Hall resistivity.

  4. 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.; Zhong, Xiaoxi

    2014-09-15

    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.

  5. Magneto-transport analysis of an ultra-low-density two-dimensional hole gas in an undoped strained Ge/SiGe heterostructure

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

    Laroche, D.; Huang, S. -H.; Chuang, Y.; Li, J. -Y.; Liu, C. W.; Lu, T. M.

    2016-06-06

    We report the magneto-transport, scattering mechanisms, and e ective mass analysis of an ultralow density two-dimensional hole gas capacitively induced in an undoped strained Ge/Si0:2Ge0:8 heterostructure. This fabrication technique allows hole densities as low as p 1:1 1010 cm² to be achieved, more than one order of magnitude lower than previously reported in doped Ge/SiGe heterostructures. The power-law exponent of the electron mobility versus density curve, / n , is found to be 0:29 over most of the density range, implying that background impurity scattering is the dominant scattering mechanism at intermediate densities in such devices. A charge migration modelmore » is used to explain the mobility decrease at the highest achievable densities. The hole e ective mass is deduced from the temperature dependence of Shubnikov-de Haas oscillations. At p 1:0 1011cm², the e ective mass m is 0:105 m0, which is signi cantly larger than masses obtained from modulation-doped Ge/SiGe two-dimensional hole gases.« less

  6. transportation

    National Nuclear Security Administration (NNSA)

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    Pantex Plant's Calvin Nelson honored as Analyst of the Year for Transportation Security http:nnsa.energy.gov...

  7. Ferromagnetism and Nonmetallic Transport of Thin-Film α - 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; et al

    2015-04-07

    A metastable phase α-FeSi₂ was epitaxially stabilized on a silicon substrate using pulsed laser deposition. Nonmetallic and ferromagnetic behaviors are tailored on α-FeSi₂ (111) thin films, while the bulk material of α-FeSi₂ 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 α-FeSi₂ obtained within density functional calculations and Boltzmann transport calculations with and without strain. Our finding shedsmore » 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.« less

  8. WIPP Documents - Transportation

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  9. Charge transport properties of p-CdTe/n-CdTe/n{sup +}-Si diode-type nuclear radiation detectors based on metalorganic vapor-phase epitaxy-grown epilayers

    SciTech Connect (OSTI)

    Niraula, M.; Yasuda, K.; Wajima, Y.; Yamashita, H.; Tsukamoto, Y.; Suzuki, Y.; Matsumoto, M.; Takai, N.; Tsukamoto, Y.; Agata, Y.

    2013-10-28

    Charge transport properties of p-CdTe/n-CdTe/n{sup +}-Si diode-type nuclear radiation detectors, fabricated by growing p-and n-type CdTe epilayers on (211) n{sup +}-Si substrates using metalorganic vapor-phase epitaxy (MOVPE), were studied by analyzing current-voltage characteristics measured at various temperatures. The diode fabricated shows good rectification properties, however, both forward and reverse biased currents deviate from their ideal behavior. The forward current exhibits typical feature of multi-step tunneling at lower biases; however, becomes space charge limited type when the bias is increased. On the other hand, the reverse current exhibits thermally activated tunneling-type current. It was found that trapping centers at the p-CdTe/n-CdTe junction, which were formed due to the growth induced defects, determine the currents of this diode, and hence limit the performance of the nuclear radiation detectors developed.

  10. Effect of Cr substitution on the magnetic and magnetic-transport properties of Fe{sub 2}Mn{sub 1-x}Cr{sub x}Si alloys

    SciTech Connect (OSTI)

    Pal, Lakhan; Gupta, Sachin; Suresh, K. G.; Nigam, A. K.

    2014-05-07

    Fe{sub 2}Mn{sub 1-x}Cr{sub x}Si (x?=?0, 0.1, and 0.2) alloys were investigated for their magnetic and transport properties in view of the expected half metallicity. It is found that Cr substitution suppresses the antiferromagnetic phase present in parent Fe{sub 2}MnSi, which completely disappears for x?=?0.2. Curie temperature of the alloys increases from 230?K to 299?K as x is increased from 0 to 0.2. The value of the Rhodes-Wohlfarth ratio indicates that the system shows iterant magnetism. Resistivity measurements also show absence of antiferromagnetic phase for x?=?0.2. Resistivity data have been fitted by considering the electron-phonon and electron-magnon scattering contributions, which indicates the presence of half metallicity in these compounds. Temperature dependence of resistivity data shows magnetoresistance of ?3% and ?2.5% at Curie temperature with applied field of 50 kOe for x?=?0.1 and 0.2, respectively.

  11. Junction Transport in Epitaxial Film Silicon Heterojunction Solar Cells

    SciTech Connect (OSTI)

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

    2011-01-01

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

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

    SciTech Connect (OSTI)

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

    2011-07-01

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

  13. 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.; Sun, Y.; He, Y. J.; Xu, L.; Xu, J.

    2014-01-28

    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.

  14. 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.

  15. Transportation Research

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

    transportation-research TRACC RESEARCH Computational Fluid Dynamics Computational Structural Mechanics Transportation Systems Modeling Transportation Research Current Research Overview The U.S. Department of Transportation (USDOT) has established its only high-performance computing and engineering analysis research facility at Argonne National Laboratory to provide applications support in key areas of applied research and development for the USDOT community. The Transportation Research and

  16. Lattice, Ce-L{sub 3}valence, transport, and magnetic results on mixed-valent/Kondo system Ce{sub 1{minus}x}La{sub x}Mn{sub 2}Si{sub 2}

    SciTech Connect (OSTI)

    Liang, G.; Xi, H.; Roberts, E.; Binford, T.; Mochizuki, K.; Markert, J.T.; Croft, M.

    1997-04-01

    Lattice, Ce-L{sub 3} edge, resistivity, and magnetic susceptibility measurements have been carried out on the polycrystalline Ce{sub 1{minus}x}La{sub x}Mn{sub 2}Si{sub 2} system (0{le}x{le}1) to study the interplay between Mn 3d-host magnetism and Kondo-type Ce-spin fluctuations. As x increases, the system varies gradually from a Ce mixed-valent system with 3d-host antiferromagnetism (at x=0) to a nearly trivalent system with strong 3d-host ferromagnetism (near x=1). In the antiferromagnetic (AF) phase region (0{le}x{le}0.5), the Neel temperature T{sub N} decreases with the increase of x, manifesting the weakening of the host AF field. Impurity Kondo behavior is observed at x=0.05, indicating that the low-temperature coherence state in CeMn{sub 2}Si{sub 2} can be destroyed by {open_quotes}Kondo holes{close_quotes} which are created by very small substitution of La for Ce. The susceptibility and resistivity results suggest that the impurity Kondo effect in the 0.1{le}x{le}0.5 samples is partially suppressed by a nonvanishing ferromagnetic (FM) field component; whereas the phononlike behavior of the resistivity curves in the Mn-host FM-phase region (0.5{lt}x{le}1.0) supports our previous proposal that the Kondo-type Ce-spin fluctuations can be effectively quenched by a strong 3d-host FM field. {copyright} {ital 1997 American Institute of Physics.}

  17. FRV Deleware II cruise, 30 June to 7 July 1978. Data report

    SciTech Connect (OSTI)

    Behrens, W.; von Bock, K.

    1982-05-01

    This was the last of three companion cruises designed to provide broad-scale coverage of seasonal shelf conditions occurring between the April and October investigations undertaken aboard ATLANTIS II cruises 99 and 104.

  18. Radiation Transport

    SciTech Connect (OSTI)

    Urbatsch, Todd James

    2015-06-15

    We present an overview of radiation transport, covering terminology, blackbody raditation, opacities, Boltzmann transport theory, approximations to the transport equation. Next we introduce several transport methods. We present a section on Caseology, observing transport boundary layers. We briefly broach topics of software development, including verification and validation, and we close with a section on high energy-density experiments that highlight and support radiation transport.

  19. Chamber transport

    SciTech Connect (OSTI)

    OLSON,CRAIG L.

    2000-05-17

    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.

  20. Plastic relaxation in GeSi layers on Si (001) and Si (115) substrates

    SciTech Connect (OSTI)

    Drozdov, Yu. N. Drozdov, M. N.; Yunin, P. A.; Yurasov, D. V.; Shaleev, M. A.; Novikov, A. V.

    2015-01-15

    It is demonstrated using X-ray diffraction and atomic force microscopy that elastic stresses in GeSi layers on Si (115) substrates relax more effectively than in the same layers on Si (001) substrates. This fact is attributed to the predominant contribution of one of the (111) slip planes on the (115) cut. The atomicforce-microscopy image of the GeSi/Si(115) surface reveals unidirectional slip planes, while the GeSi/Si(001) image contains a grid of orthogonal lines and defects at the points of their intersection. As a result, thick GeSi layers on Si (115) have a reduced surface roughness. A technique for calculating the parameters of relaxation of the layer on the Si (115) substrate using X-ray diffraction data is discussed.

  1. Potential variation around grain boundaries in BaSi{sub 2} films grown on multicrystalline silicon evaluated using Kelvin probe force microscopy

    SciTech Connect (OSTI)

    Baba, Masakazu; Tsukahara, Daichi; Toko, Kaoru; Hara, Kosuke O.; Usami, Noritaka; Sekiguchi, Takashi; Suemasu, Takashi

    2014-12-21

    Potential variations across the grain boundaries (GBs) in a 100?nm thick undoped n-BaSi{sub 2} film on a cast-grown multicrystalline Si (mc-Si) substrate are evaluated using Kelvin probe force microscopy (KFM). The ?-2? X-ray diffraction pattern reveals diffraction peaks, such as (201), (301), (410), and (411) of BaSi{sub 2}. Local-area electron backscatter diffraction reveals that the a-axis of BaSi{sub 2} is tilted slightly from the surface normal, depending on the local crystal plane of the mc-Si. KFM measurements show that the potentials are not significantly disordered in the grown BaSi{sub 2}, even around the GBs of mc-Si. The potentials are higher at GBs of BaSi{sub 2} around Si GBs that are formed by grains with a Si(111) face and those with faces that deviate slightly from Si(111). Thus, downward band bending occurs at these BaSi{sub 2} GBs. Minority carriers (holes) undergo a repelling force near the GBs, which may suppress recombination as in the case of undoped n-BaSi{sub 2} epitaxial films on a single crystal Si(111) substrate. The barrier height for hole transport across the GBs varies in the range from 10 to 55?meV. The potentials are also higher at the BaSi{sub 2} GBs grown around Si GBs composed of grains with Si(001) and Si(111) faces. The barrier height for hole transport ranges from 5 to 55?meV. These results indicate that BaSi{sub 2} GBs formed on (111)-dominant Si surfaces do not have a negative influence on the minority-carrier properties, and thus BaSi{sub 2} formed on underlayers, such as (111)-oriented Si or Ge and on (111)-oriented mc-Si, can be utilized as a solar cell active layer.

  2. Nanocrystalline SiC and Ti3SiC2 Alloys for Reactor Materials: Annual Report

    SciTech Connect (OSTI)

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

    2015-01-15

    A new dual-phase nanocomposite of Ti₃SiC₂/SiC is being synthesized using preceramic polymers, ceramic powders, and carbon nanotubes (CNTs) designed to be suitable for advanced nuclear reactors and perhaps as fuel cladding. The material is being designed to have superior fracture toughness compared to SiC, adequate thermal conductivity, and higher density than SiC/SiC composites. This annual report summarizes the progress towards this goal and reports progress in understanding certain aspects of the material behavior but some shortcomings in achieving full density or in achieving adequate incorporation of CNTs. The measured thermal conductivity is adequate and falls into an expected range based on SiC and Ti₃SiC₂. Part of this study makes an initial assessment for Ti₃SiC₂ as a barrier to fission product transport. Ion implantation was used to introduce fission product surrogates (Ag and Cs) and a noble metal (Au) in Ti₃SiC₂, SiC, and a synthesized at PNNL. 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. Progress is reported in thermal conductivity modeling of SiC-based materials that is relevant to this research, as is progress in modeling the effects of CNTs on fracture strength of SiC-based materials.

  3. Optimizing the transverse thermal conductivity of 2D-SiCf/SiC composites, II. Experimental

    SciTech Connect (OSTI)

    Youngblood, Gerald E; Senor, David J; Jones, Russell H; Kowbel, W

    2002-12-31

    Model predictions of the transverse thermal conductivity (Keff) are compared to experimentally determined values as a function of temperature for a commercial 2D-SiCf/SiC made by DuPont from plain weave Hi-Nicalon fabric and with an ICVI-SiC matrix. Two versions of the DuPont composite were examined: one with a “thin” and one with a “thick” pyrolytic carbon coating of thickness 0.110 m and 1.044 m, respectively. Generally good agreement of the model predictions with measured values of Keff suggest that these models can be used to predict Keff for composites with various “non-ideal” fiber, interphase and matrix structures. Importantly, the models make it possible to separate the relative component contributions to Keff so that individual component degradation mechanisms can be examined in detail. Then, based on specific knowledge of the component degradation, the models can used to predict Keff-values for composites subjected to irradiation, oxidation, thermal cycling, or other thermal or mechanical stress treatments. Finally, model predictions were examined to suggest specific design and/or development efforts directed to optimize the overall thermal transport performance of 2D-SiCf/SiC.

  4. Beam Transport

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

    Beam Transport A simplified drawing of the beam transport system from the linac to Target-1 (Lujan Center), Target-2 (Blue Room) and Target-4 is shown below. In usual operation ...

  5. WIPP Transportation

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

    Transuranic Waste Transportation Container Documents Documents related to transuranic waste containers and packages. CBFO Tribal Program Information about WIPP shipments across tribal lands. Transportation Centralized Procurement Program - The Centralized Procurement Program provides a common method to procure standard items used in the packaging and handling of transuranic wasted destined for WIPP. Transuranic Waste Transportation Routes - A map showing transuranic waste generator sites and

  6. Effect of Mn substitution on the transport properties of co-sputtered...

    Office of Scientific and Technical Information (OSTI)

    on the transport properties of co-sputtered Fesub 3-xMnsub xSi epilayers Citation Details In-Document Search Title: Effect of Mn substitution on the transport properties of ...

  7. Native defects in Tl6SI4: Density functional calculations

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

    Shi, Hongliang; Du, Mao -Hua

    2015-05-05

    In this study, Tl6SI4 is a promising room-temperature semiconductor radiation detection material. Here, we report density functional calculations of native defects and dielectric properties of Tl6SI4. Formation energies and defect levels of native point defects and defect complexes are calculated. Donor-acceptor defect complexes are shown to be abundant in Tl6SI4. High resistivity can be obtained by Fermi level pinning by native donor and acceptor defects. Deep donors that are detrimental to electron transport are identified and methods to mitigate such problem are discussed. Furthermore, we show that mixed ionic-covalent character of Tl6SI4 gives rise to enhanced Born effective charges andmore » large static dielectric constant, which provides effective screening of charged defects and impurities.« less

  8. 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 schedule options. Our goal is to reduce emissions related to employee travel and commuting to and from work by 13 percent. Energy Conservation» Efficient Water Use & Management» High Performance Sustainable Buildings» Greening Transportation» Green Purchasing & Green Technology» Pollution Prevention» Science

  9. Sustainable Transportation

    SciTech Connect (OSTI)

    2012-09-01

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

  10. Optimizing the transverse thermal conductivity of 2D-SiCf/SiC composites, I. Modeling

    SciTech Connect (OSTI)

    Youngblood, Gerald E.; Senor, David J.; Jones, Russell H.

    2002-12-31

    For potential fusion applications, considerable fabrication efforts have been directed to obtaining transverse thermal conductivity (Keff) values in excess of 30 W/mK (unirradiated) in the 800-1000°C temperature range for 2D-SiCf/SiC composites. To gain insight into the factors affecting Keff, at PNNL we have tested three different analytic models for predicting Keff in terms of constituent (fiber, matrix and interphase) properties. The tested models were: the Hasselman-Johnson (H-J) “2-Cylinder” model, which examines the effects of fiber-matrix (f/m) thermal barriers; the Markworth “3-Cylinder” model, which specifically examines the effects of interphase thickness and thermal conductivity; and a newly-developed Anisotropic “3-Square” model, which examines the potential effect of introducing a fiber coating with anisotropic properties to enhance (or diminish) f/m thermal coupling. The first two models are effective medium models, while the third model is a simple combination of parallel and series conductances. Model predictions suggest specific designs and/or development efforts directed to optimize the overall thermal transport performance of 2D-SiCf/SiC.

  11. Transportation Energy

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

    Energy Home/Transportation Energy CRF_climatechange Permalink Gallery Understanding Hazardous Combustion Byproducts Reduces Factors Impacting Climate Change CRF, Global Climate & Energy, News, News & Events, Transportation Energy Understanding Hazardous Combustion Byproducts Reduces Factors Impacting Climate Change By Micheal Padilla Researchers at Sandia's Combustion Research Facility are developing the understanding necessary to build cleaner combustion technologies that will in turn

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

    SciTech Connect (OSTI)

    Cao, Guixin; Singh, David J; Zhang, Xiaoguang; Samolyuk, German D; Qiao, Liang; Parish, Chad M; Ke, Jin; Zhang, Yanwen; Guo, Hangwen; Tang, Siwei; Wang, Wenbin; Yi, Jieyu; Cantoni, Claudia; Siemons, Wolter; Payzant, E Andrew; Biegalski, Michael D; Ward, Thomas Zac; Sales, Brian C; Mandrus, D.; Stocks, George Malcolm; Gai, Zheng

    2015-01-01

    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. Tunneling magnetoresistance in Fe{sub 3}Si/MgO/Fe{sub 3}Si(001) magnetic tunnel junctions

    SciTech Connect (OSTI)

    Tao, L. L.; Liang, S. H.; Liu, D. P.; Wei, H. X.; Han, X. F.; Wang, Jian

    2014-04-28

    We present a theoretical study of the tunneling magnetoresistance (TMR) and spin-polarized transport in Fe{sub 3}Si/MgO/Fe{sub 3}Si(001) magnetic tunnel junction (MTJ). It is found that the spin-polarized conductance and bias-dependent TMR ratios are rather sensitive to the structure of Fe{sub 3}Si electrode. From the symmetry analysis of the band structures, we found that there is no spin-polarized Δ{sub 1} symmetry bands crossing the Fermi level for the cubic Fe{sub 3}Si. In contrast, the tetragonal Fe{sub 3}Si driven by in-plane strain reveals half-metal nature in terms of Δ{sub 1} state. The giant TMR ratios are predicted for both MTJs with cubic and tetragonal Fe{sub 3}Si electrodes under zero bias. However, the giant TMR ratio resulting from interface resonant transmission for the former decreases rapidly with the bias. For the latter, the giant TMR ratio can maintain up to larger bias due to coherent transmission through the majority-spin Δ{sub 1} channel.

  14. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect (OSTI)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2003-01-01

    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.

  15. Transportation | NREL

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

    Transportation NREL's transportation infrastructure and programs are designed to significantly reduce petroleum use campus-wide. This infographic shows NREL's FY2015 fleet performance and fleet vehicle history compared to baseline FY 2005 and FY 2014. Petroleum fuel use decreased 28% from 2014 and increased 17% from baseline 2005. Alternative fuel use increased 53% from 2014 and increased 127% from baseline 2005. In baseline 2005, the fleet used 6,521 gasoline gallon equivalent (GGE) of E-85, in

  16. TRANSPORTATION OPTIONS

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

    TRANSPORTATION OPTIONS The Pittsburgh Airport Marriott provides complimentary shuttle service. The hotel asks all guests arriving at the Pittsburgh International Airport to collect luggage in the baggage claim area of the airport and then call for the shuttle at 412-788- 8800. Let the Hotel Operator know that you have collected your luggage and have a reservation at the Marriott and need transportation from the airport. The Hotel Operator will instruct the guest which door to exit, which curb to

  17. NREL: Transportation Research - Transportation News

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

    Transportation News The following news stories highlight transportation research at NREL. August 25, 2016 NREL and NASA Receive Regional FLC Award for Notable Technology NASA Johnson Space Center (JSC) and the National Renewable Energy Laboratory (NREL) were selected as 2016 recipients of a Federal Laboratory Consortium (FLC) Mid-Continent Regional Award, for their notable technology development of the patented Battery Internal Short-Circuit (ISC) Device. August 25, 2016 NREL Helps the National

  18. Transportation Energy

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

    Energy admin 2015-05-14T22:34:50+00:00 Transportation Energy The national-level objective for the future is to create a carbon-neutral fleet that is powered by low-carbon US sources. Sandia delivers advanced technologies and design tools to the broad transportation sector in the following areas: Predictive Simulation of Engines Fuel sprays and their transition from the liquid to gas phase and computationally tractable models that capture the physics of combustion. Convergence of Biofuels and

  19. Scattering mechanisms in shallow undoped Si/SiGe quantum wells

    SciTech Connect (OSTI)

    Laroche, D.; Nielsen, E.; Lu, T. M.; Huang, S.-H.; Chuang, Y.; Li, J.-Y. Liu, C. W.

    2015-10-15

    We report the magneto-transport study and scattering mechanism analysis of a series of increasingly shallow Si/SiGe quantum wells with depth ranging from ∼ 100 nm to ∼ 10 nm away from the heterostructure surface. The peak mobility increases with depth, suggesting that charge centers near the oxide/semiconductor interface are the dominant scattering source. The power-law exponent of the electron mobility versus density curve, μ ∝ n{sup α}, is extracted as a function of the depth of the Si quantum well. At intermediate densities, the power-law dependence is characterized by α ∼ 2.3. At the highest achievable densities in the quantum wells buried at intermediate depth, an exponent α ∼ 5 is observed. We propose and show by simulations that this increase in the mobility dependence on the density can be explained by a non-equilibrium model where trapped electrons smooth out the potential landscape seen by the two-dimensional electron gas.

  20. Scattering mechanisms in shallow undoped Si/SiGe quantum wells

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

    Laroche, Dominique; Huang, S. -H.; Nielsen, Erik; Chuang, Y.; Li, J. -Y.; Liu, C. W.; Lu, Tzu -Ming

    2015-10-07

    We report the magneto-transport study and scattering mechanism analysis of a series of increasingly shallow Si/SiGe quantum wells with depth ranging from ~ 100 nm to ~ 10 nm away from the heterostructure surface. The peak mobility increases with depth, suggesting that charge centers near the oxide/semiconductor interface are the dominant scattering source. The power-law exponent of the electron mobility versus density curve, μ ∝ nα, is extracted as a function of the depth of the Si quantum well. At intermediate densities, the power-law dependence is characterized by α ~ 2.3. At the highest achievable densities in the quantum wellsmore » buried at intermediate depth, an exponent α ~ 5 is observed. Lastly, we propose and show by simulations that this increase in the mobility dependence on the density can be explained by a non-equilibrium model where trapped electrons smooth out the potential landscape seen by the two-dimensional electron gas.« less

  1. Scattering mechanisms in shallow undoped Si/SiGe quantum wells

    SciTech Connect (OSTI)

    Laroche, Dominique; Huang, S. -H.; Nielsen, Erik; Chuang, Y.; Li, J. -Y.; Liu, C. W.; Lu, Tzu -Ming

    2015-10-07

    We report the magneto-transport study and scattering mechanism analysis of a series of increasingly shallow Si/SiGe quantum wells with depth ranging from ~ 100 nm to ~ 10 nm away from the heterostructure surface. The peak mobility increases with depth, suggesting that charge centers near the oxide/semiconductor interface are the dominant scattering source. The power-law exponent of the electron mobility versus density curve, μ ∝ nα, is extracted as a function of the depth of the Si quantum well. At intermediate densities, the power-law dependence is characterized by α ~ 2.3. At the highest achievable densities in the quantum wells buried at intermediate depth, an exponent α ~ 5 is observed. Lastly, we propose and show by simulations that this increase in the mobility dependence on the density can be explained by a non-equilibrium model where trapped electrons smooth out the potential landscape seen by the two-dimensional electron gas.

  2. Si Brilliant Technology Ltd | Open Energy Information

    Open Energy Info (EERE)

    Si Brilliant Technology Ltd Jump to: navigation, search Name: Si-Brilliant Technology Ltd Place: Zhejiang Province, China Sector: Solar Product: Chinese solar-grade polysilicon...

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

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

    Cao, Guixin; Singh, David J; Zhang, Xiaoguang; Samolyuk, German D; Qiao, Liang; Parish, Chad M; Ke, Jin; Zhang, Yanwen; Guo, Hangwen; Wang, Wenbin; et al

    2015-01-01

    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 transportmore » calculations with and without strain. Our findings provide an example of a tailored material with interesting physics properties for practical applications.« less

  4. Transportation Fuels

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

    Fuels DOE would invest $52 million to fund a major fleet transformation at Idaho National Laboratory, along with the installation of nine fuel management systems, purchase of additional flex fuel cars and one E85 ethanol fueling station. Transportation projects, such as the acquisition of highly efficient and alternative-fuel vehicles, are not authorized by ESPC legislation. DOE has twice proportion of medium vehicles and three times as many heavy vehicles as compared to the Federal agency

  5. Composite oxygen ion transport element

    DOE Patents [OSTI]

    Chen, Jack C.; Besecker, Charles J.; Chen, Hancun; Robinson, Earil T.

    2007-06-12

    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. A=17Si (1993TI07)

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

    Si (1993TI07) (Not observed) See (1983ANZQ, 1988WA18, 1992AV03).

  7. Transportation Infrastructure

    Office of Environmental Management (EM)

    09 Archive Transportation Fact of the Week - 2009 Archive #603 Where Does Lithium Come From? December 28, 2009 #602 Freight Statistics by Mode, 2007 Commodity Flow Survey December 21, 2009 #601 World Motor Vehicle Production December 14, 2009 #600 China Produced More Vehicles than the U.S. in 2008 December 7, 2009 #599 Historical Trend for Light Vehicle Sales November 30, 2009 #598 Hybrid Vehicle Sales by Model November 23, 2009 #597 Median Age of Cars and Trucks Rising in 2008 November 16, 2009

  8. Mo-Si alloy development

    SciTech Connect (OSTI)

    Liu, C.T.; Heatherly, L.; Wright, J.L.

    1996-06-01

    The objective of this task is to develop new-generation corrosion-resistant Mo-Si intermetallic alloys as hot components in advanced fossil energy conversion and combustion systems. The initial effort is devoted to Mo{sub 5}-Si{sub 3}-base (MSB) alloys containing boron additions. Three MSB alloys based on Mo-10.5Si-1.1B (wt %), weighing 1500 g were prepared by hot pressing of elemental and alloy powders at temperatures to 1600{degrees}C in vacuum. Microporosities and glassy-phase (probably silicate phases) formations are identified as the major concerns for preparation of MSB alloys by powder metallurgy. Suggestions are made to alleviate the problems of material processing.

  9. Anisotropy of heat conduction in Mo/Si multilayers

    SciTech Connect (OSTI)

    Medvedev, V. V.; Yakshin, A. E.; Kruijs, R. W. E. van de; Bijkerk, F.; Yang, J.; Schmidt, A. J.; Zoethout, E.

    2015-08-28

    This paper reports on the studies of anisotropic heat conduction phenomena in Mo/Si multilayers with individual layer thicknesses selected to be smaller than the mean free path of heat carriers. We applied the frequency-domain thermoreflectance technique to characterize the thermal conductivity tensor. While the mechanisms of the cross-plane heat conduction were studied in detail previously, here we focus on the in-plane heat conduction. To analyze the relative contribution of electron transport to the in-plane heat conduction, we applied sheet-resistance measurements. Results of Mo/Si multilayers with variable thickness of the Mo layers indicate that the net in-plane thermal conductivity depends on the microstructure of the Mo layers.

  10. Low Activation Joining of SiC/SiC Composites for Fusion Applications: Tape Casting TiC+Si Powders

    SciTech Connect (OSTI)

    Henager, Charles H.; Kurtz, Richard J.; Canfield, Nathan L.; Shin, Yongsoon; Luscher, Walter G.; Mansurov, Jirgal; Roosendaal, Timothy J.; Borlaug, Brennan A.

    2014-03-03

    This work discusses the latest developments in TiC + Si displacement reaction joining at PNNL based on new work to produce tape-cast powders for improved SiC-joints.

  11. The HFIR 14J irradiation SiC/SiC composite and SiC fiber collaboration

    SciTech Connect (OSTI)

    Youngblood, G.E.; Jones, R.H.; Kohyama, Akira; Katoh, Yutai; Hasegawa, Akira; Snead, L.; Scholz, R.

    1998-09-01

    A short introduction with references establishes the current status of research and development of SiC{sub f}/SiC composites for fusion energy systems with respect to several key issues. The SiC fiber and composite specimen types selected for the JUPITER 14J irradiation experiment are presented together with the rationale for their selection.

  12. Centrotherm SiQ | Open Energy Information

    Open Energy Info (EERE)

    SiQ Jump to: navigation, search Name: Centrotherm SiQ Place: Germany Product: JV company by SolMic and Centrotherm to design and manufacture 'Siemens type' CVD reactors and STC-TCS...

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

    SciTech Connect (OSTI)

    Wejrzanowski, T.; Grybczuk, M.; Kurzydlowski, K. J.; Tymicki, E.

    2014-10-06

    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.

  14. 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)

    2014-11-03

    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.

  15. Transporting particulate material

    DOE Patents [OSTI]

    Aldred, Derek Leslie; Rader, Jeffrey A.; Saunders, Timothy W.

    2011-08-30

    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.

  16. Transportation Systems Modeling

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

    TRACC RESEARCH Computational Fluid Dynamics Computational Structural Mechanics Transportation Systems Modeling TRANSPORTATION SYSTEMS MODELING Overview of TSM Transportation systems modeling research at TRACC uses the TRANSIMS (Transportation Analysis SIMulation System) traffic micro simulation code developed by the U.S. Department of Transportation (USDOT). The TRANSIMS code represents the latest generation of traffic simulation codes developed jointly under multiyear programs by USDOT, the

  17. Oxygen Transport Ceramic Membranes

    SciTech Connect (OSTI)

    S. Bandopadhyay; N. Nagabhushana

    2003-08-07

    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.

  18. Transportation Data Programs:Transportation Energy Data Book...

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

    Transportation Data Programs:Transportation Energy Data Book,Vehicle Technologies Market Report, and VT Fact of the Week Transportation Data Programs:Transportation Energy Data ...

  19. Transportation Fuel Supply | NISAC

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

    Transportation Equipment (2010 MECS) Transportation Equipment (2010 MECS) Manufacturing Energy and Carbon Footprint for Transportation Equipment Sector (NAICS 336) Energy use data source: 2010 EIA MECS (with adjustments) Footprint Last Revised: February 2014 View footprints for other sectors here. Manufacturing Energy and Carbon Footprint Transportation Equipment (125.57 KB) More Documents & Publications MECS 2006 - Transportation Equipment

    SheetsTransportation Fuel Supply content top

  20. Water Transport Exploratory Studies

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

    Develop understanding of water transport in PEM Fuel Cells (non-design-specific) * Evaluate structural and surface properties of materials affecting water transport and performance ...

  1. National Transportation Stakeholders Forum

    Office of Environmental Management (EM)

    National Transportation Stakeholders Forum OSRP * NNSA Contractors transporting in commerce, are required law to comply with applicable regulations required law to comply with ...

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

    SciTech Connect (OSTI)

    Norris, D. J.; Qiu, Y.; Walther, T.; Dobbie, A.; Myronov, M.

    2014-01-07

    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 < x ≤ 1 form islands after deposition of ∼3.0/x monolayers (=quarter unit cells in the diamond lattice, ML). The uncertainty in the amount of deposited material for pure Ge is ±(0.2–0.3) ML. Modelling shows that of the amount of germanium deposited, 0.7 ML segregate towards the free surface so that only ∼2.3/x ML are directly incorporated in the layer within a few nanometres, in good agreement with our measurements. For pure Ge (x = 1), this thickness is smaller than most values quoted in the literature, which we attribute to the high sensitivity of our method to fractional monolayer changes in the effective chemical width of such thin layers.

  3. si

    Office of Legacy Management (LM)

    ... per minute per 100 square centimeters EML EPA ESSAP ft3 FUSRAP GM ha kg km MeV ZI NBL NIST ORISE PMC ZnS Environmental Measurement Laboratories Environmental Protection ...

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

    DOE Patents [OSTI]

    Liliental-Weber, Zuzanna; Maltez, Rogerio Luis; Morkoc, Hadis; Xie, Jinqiao

    2011-08-30

    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.

  5. Nanocrystalline Si pathway induced unipolar resistive switching behavior from annealed Si-rich SiN{sub x}/SiN{sub y} multilayers

    SciTech Connect (OSTI)

    Jiang, Xiaofan; Ma, Zhongyuan Yang, Huafeng; Yu, Jie; Wang, Wen; Zhang, Wenping; Li, Wei; Xu, Jun; Xu, Ling; Chen, Kunji; Huang, Xinfan; Feng, Duan

    2014-09-28

    Adding a resistive switching functionality to a silicon microelectronic chip is a new challenge in materials research. Here, we demonstrate that unipolar and electrode-independent resistive switching effects can be realized in the annealed Si-rich SiN{sub x}/SiN{sub y} multilayers with high on/off ratio of 10{sup 9}. High resolution transmission electron microscopy reveals that for the high resistance state broken pathways composed of discrete nanocrystalline silicon (nc-Si) exist in the Si nitride multilayers. While for the low resistance state the discrete nc-Si regions is connected, forming continuous nc-Si pathways. Based on the analysis of the temperature dependent I-V characteristics and HRTEM photos, we found that the break-and-bridge evolution of nc-Si pathway is the origin of resistive switching memory behavior. Our findings provide insights into the mechanism of the resistive switching behavior in nc-Si films, opening a way for it to be utilized as a material in Si-based memories.

  6. Low Activation Joining of SiC/SiC Composites for Fusion Applications: Tape Casting TiC+Si Powders

    SciTech Connect (OSTI)

    Henager, Charles H.; Kurtz, Richard J.; Canfield, Nathan L.; Shin, Yongsoon; Luscher, Walter G.; Mansurov, Jirgal; Roosendaal, Timothy J.; Borlaug, Brennan A.

    2013-08-06

    The use of SiC composites in fusion environments likely requires joining of plates using reactive joining or brazing. One promising reactive joining method uses solid-state displacement reactions between Si and TiC to produce Ti3SiC2 + SiC. We continue to explore the processing envelope for this joint for the TITAN collaboration in order to produce optimal joints to undergo irradiation studies in HFIR. One noted feature of the joints produced using tape-calendared powders of TiC+Si has been the large void regions that have been apparently unavoidable. Although the produced joints are very strong, these voids are undesirable. In addition, the tapes that were made for this joining were produced about 20 years ago and were aging. Therefore, we embarked on an effort to produce some new tape cast powders of TiC and Si that could replace our aging tape calendared materials.

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

    SciTech Connect (OSTI)

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

    2014-01-01

    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.

  8. Transportation Organization and Functions

    Broader source: Energy.gov [DOE]

    Office of Packaging and Transportation list of organizations and functions, with a list of acronyms.

  9. Electronic properties of phosphorus doped silicon nanocrystals embedded in SiO{sub 2}

    SciTech Connect (OSTI)

    Gutsch, Sebastian; Laube, Jan; Hiller, Daniel; Zacharias, Margit; Bock, Wolfgang; Wahl, Michael; Kopnarski, Michael; Gnaser, Hubert; Puthen-Veettil, Binesh

    2015-03-16

    We study the electronic properties of phosphorus doped Si nanocrystal/SiO2 superlattices and determine the carrier concentration by transient current analysis. This is achieved by encapsulating the multilayers between two electrical insulation layers and controlling the carrier mobility by a defined layer to layer separation. A saturation of the voltage dependent ionized carrier density is observed which indicates complete substitutional dopant ionization and allows to calculate the dopant induced charge carrier density. It is found that the doping efficiency of the superlattice is only 0.12% considering the full ionization regime which explains the unusual small dopant effect on transport characteristics.

  10. Chemical compatibility issues associated with use of SiC/SiC in advanced reactor concepts

    SciTech Connect (OSTI)

    Wilson, Dane F.

    2015-09-01

    Silicon carbide/silicon carbide (SiC/SiC) composites are of interest for components that will experience high radiation fields in the High Temperature Gas Cooled Reactor (HTGR), the Very High Temperature Reactor (VHTR), the Sodium Fast Reactor (SFR), or the Fluoride-cooled High-temperature Reactor (FHR). In all of the reactor systems considered, reactions of SiC/SiC composites with the constituents of the coolant determine suitability of materials of construction. The material of interest is nuclear grade SiC/SiC composites, which consist of a SiC matrix [high-purity, chemical vapor deposition (CVD) SiC or liquid phase-sintered SiC that is crystalline beta-phase SiC containing small amounts of alumina-yttria impurity], a pyrolytic carbon interphase, and somewhat impure yet crystalline beta-phase SiC fibers. The interphase and fiber components may or may not be exposed, at least initially, to the reactor coolant. The chemical compatibility of SiC/SiC composites in the three reactor environments is highly dependent on thermodynamic stability with the pure coolant, and on reactions with impurities present in the environment including any ingress of oxygen and moisture. In general, there is a dearth of information on the performance of SiC in these environments. While there is little to no excess Si present in the new SiC/SiC composites, the reaction of Si with O2 cannot be ignored, especially for the FHR, in which environment the product, SiO2, can be readily removed by the fluoride salt. In all systems, reaction of the carbon interphase layer with oxygen is possible especially under abnormal conditions such as loss of coolant (resulting in increased temperature), and air and/ or steam ingress. A global outline of an approach to resolving SiC/SiC chemical compatibility concerns with the environments of the three reactors is presented along with ideas to quickly determine the baseline compatibility performance of SiC/SiC.

  11. NREL: Transportation Research - Sustainable Transportation Basics

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

    Transportation Basics Compare Vehicle Technologies 3-D illustration of electric car diagramming energy storage, power electronics, and climate control components. The following links to the U.S. Department of Energy's Alternative Fuels Data Center (AFDC) provide an introduction to sustainable transportation. NREL research supports development of electric, hybrid, hydrogen fuel cell, biofuel, natural gas, and propane vehicle technologies. Learn more about vehicles, fuels, and transportation

  12. NREL: Transportation Research - Transportation Deployment Support

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

    Transportation Deployment Support Photo of a car parked in front of a monument. A plug-in electric vehicle charges near the Thomas Jefferson Memorial in Washington, D.C. Photo from Julie Sutor, NREL NREL's transportation deployment team works with vehicle fleets, fuel providers, and other transportation stakeholders to help deploy alternative and renewable fuels, advanced vehicles, fuel economy improvements, and fleet-level efficiencies that reduce emissions and petroleum dependence. In

  13. NREL: Transportation Research - Transportation and Hydrogen Newsletter

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

    Transportation and Hydrogen Newsletter The Transportation and Hydrogen Newsletter is a monthly electronic newsletter that provides information on NREL's research, development, and deployment of transportation and hydrogen technologies. Photo of a stack of newspapers July 2016 Issue Hydrogen Fuel Cells Read the latest issue of the newsletter. Subscribe: To receive new issues by email, subscribe to the newsletter. Archives: For past issues, read the newsletter archives. Printable Version

  14. NREL: Transportation Research - News

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

    News NREL provides a number of transportation and hydrogen news sources. Transportation News Find news stories that highlight NREL's transportation research, development, and deployment (RD&D) activities, including work on vehicles and fuels. Hydrogen and Fuel Cells News Find news stories that highlight NREL's hydrogen RD&D activities, including work on fuel cell electric vehicle technologies. Transportation and Hydrogen Newsletter Stay up to date on NREL's RD&D of transportation and

  15. Ambipolar charge transport in microcrystalline silicon thin-film transistors

    SciTech Connect (OSTI)

    Knipp, Dietmar; Marinkovic, M.; Chan, Kah-Yoong; Gordijn, Aad; Stiebig, Helmut

    2011-01-15

    Hydrogenated microcrystalline silicon ({mu}c-Si:H) is a promising candidate for thin-film transistors (TFTs) in large-area electronics due to high electron and hole charge carrier mobilities. We report on ambipolar TFTs based on {mu}c-Si:H prepared by plasma-enhanced chemical vapor deposition at temperatures compatible with flexible substrates. Electrons and holes are directly injected into the {mu}c-Si:H channel via chromium drain and source contacts. The TFTs exhibit electron and hole charge carrier mobilities of 30-50 cm{sup 2}/V s and 10-15 cm{sup 2}/V s, respectively. In this work, the electrical characteristics of the ambipolar {mu}c-Si:H TFTs are described by a simple analytical model that takes the ambipolar charge transport into account. The analytical expressions are used to model the transfer curves, the potential and the net surface charge along the channel of the TFTs. The electrical model provides insights into the electronic transport of ambipolar {mu}c-Si:H TFTs.

  16. SiD Letter of Intent

    SciTech Connect (OSTI)

    Aihara, H.,; Burrows, P.,; Oreglia, M.,; Berger, E.L.; Guarino, V.; Repond, J.; Weerts, H.; Xia, L.; Zhang, J.; Zhang, Q.; Srivastava, A.; Butler, J.M.; Goldstein, Joel; Velthuis, J.; Radeka, V.; Zhu, R.-Y.; Lutz, P.; 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.

    2012-04-11

    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.

  17. Experimental estimation of oxidation-induced Si atoms emission on Si(001) surfaces

    SciTech Connect (OSTI)

    Ogawa, Shuichi Tang, Jiayi; Takakuwa, Yuji

    2015-08-15

    Kinetics of Si atoms emission during the oxidation of Si(001) surfaces have been investigated using reflection high energy electron diffraction combined with Auger electron spectroscopy. The area ratio of the 1 × 2 and the 2 × 1 domains on a clean Si(001) surface changed with the oxidation of the surface by Langmuir-type adsorption. This change in the domain ratio is attributed to the emission of Si atoms. We can describe the changes in the domain ratio using the Si emission kinetics model, which states that (1) the emission rate is proportional to the oxide coverage, and (2) the emitted Si atoms migrate on the surface and are trapped at S{sub B} steps. Based on our model, we find experimentally that up to 0.4 ML of Si atoms are emitted during the oxidation of a Si(001) surface at 576 °C.

  18. Structure of Si-capped Ge/SiC/Si (001) epitaxial nanodots: Implications for quantum dot patterning

    SciTech Connect (OSTI)

    Petz, C. W.; Floro, J. A.; Yang, D.; Levy, J.

    2012-04-02

    Artificially ordered quantum dot (QD) arrays, where confined carriers can interact via direct exchange coupling, may create unique functionalities such as cluster qubits and spintronic bandgap systems. Development of such arrays for quantum computing requires fine control over QD size and spatial arrangement on the sub-35 nm length scale. We employ electron-beam irradiation to locally decompose ambient hydrocarbons onto a bare Si (001) surface. These carbonaceous patterns are annealed in ultra-high vacuum (UHV), forming ordered arrays of nanoscale SiC precipitates that have been suggested to template subsequent epitaxial Ge growth to form ordered QD arrays. We show that 3C-SiC nanodots form, in cube-on-cube epitaxial registry with the Si substrate. The SiC nanodots are fully relaxed by misfit dislocations and exhibit small lattice rotations with respect to the substrate. Ge overgrowth at elevated deposition temperatures, followed by Si capping, results in expulsion of the Ge from SiC template sites due to the large chemical and lattice mismatch between Ge and C. Maintaining an epitaxial, low-defectivity Si matrix around the quantum dots is important for creating reproducible electronic and spintronic coupling of states localized at the QDs.

  19. Secure Transportation Management

    SciTech Connect (OSTI)

    Gibbs, P. W.

    2014-10-15

    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.

  20. Modification of Mg{sub 2}Si in Mg–Si alloys with gadolinium

    SciTech Connect (OSTI)

    Ye, Lingying; Hu, Jilong Tang, Changping; Zhang, Xinming; Deng, Yunlai; Liu, Zhaoyang; Zhou, Zhile

    2013-05-15

    The modification effect of gadolinium (Gd) on Mg{sub 2}Si in the hypereutectic Mg–3 wt.% Si alloy has been investigated using optical microscope, scanning electron microscope, X-ray diffraction and hardness measurements. The results indicate that the morphology of the primary Mg{sub 2}Si is changed from coarse dendrite into fine polygon with the increasing Gd content. The average size of the primary Mg{sub 2}Si significantly decreases with increasing Gd content up to 1.0 wt.%, and then slowly increases. Interestingly, when the Gd content is increased to 4.0 and 8.0 wt.%, the primary and eutectic Mg{sub 2}Si evidently decrease and even disappear. The modification and refinement of the primary Mg{sub 2}Si is mainly attributed to the poisoning effect. The GdMg{sub 2} phase in the primary Mg{sub 2}Si is obviously coarsened as the Gd content exceeds 2.0 wt.%. While the decrease and disappearance of the primary and eutectic Mg{sub 2}Si are ascribed to the formation of vast GdSi compound. Therefore, it is reasonable to conclude that proper Gd (1.0 wt.%) addition can effectively modify and refine the primary Mg{sub 2}Si. - Highlights: ► Proper Gd (1.0 wt.%) addition can effectively modify and refine the primary Mg{sub 2}Si. ► We studied the reaction feasibility between Mg and Si, Gd and Si in Mg–Gd–Si system. ► We explored the modification mechanism of Gd modifier on Mg{sub 2}Si.

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

    SciTech Connect (OSTI)

    Mkinen, A. J. Kim, Chul-Soo; Kushto, G. P.

    2014-01-27

    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.

  2. Isotropic plasma etching of Ge Si and SiNx films

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

    Henry, Michael David; Douglas, Erica Ann

    2016-05-01

    This study reports on selective isotropic dry etching of chemically vapor deposited (CVD) Ge thin film, release layers using a Shibaura chemical downstream etcher (CDE) with NF3 and Ar based plasma chemistry. Relative etch rates between Ge, Si and SiNx are described with etch rate reductions achieved by adjusting plasma chemistry with O2. Formation of oxides reducing etch rates were measured for both Ge and Si, but nitrides or oxy-nitrides created using direct injection of NO into the process chamber were measured to increase Si and SiNx etch rates while retarding Ge etching.

  3. The Role of Electron Transport and Trapping in MOS Total-Dose Modeling

    SciTech Connect (OSTI)

    Fleetwood, D.M.; Winokur, P.S.; Riewe, L.C.; Flament, O.; Paillet, P.; Leray, J.L.

    1999-07-19

    Radiation-induced hole and electron transport and trapping are fundamental to MOS total-dose models. Here we separate the effects of electron-hole annihilation and electron trapping on the neutralization of radiation-induced charge during switched-bias irradiation for hard and soft oxides, via combined thermally stimulated current (TSC) and capacitance-voltage measurements. We also show that present total-dose models cannot account for the thermal stability of deeply trapped electrons near the Si/SiO{sub 2} interface, or the inability of electrons in deep or shallow traps to contribute to TSC at positive bias following (1) room-temperature, (2) high-temperature, or (3) switched-bias irradiation. These results require revisions of modeling parameters and boundary conditions for hole and electron transport in SiO{sub 2}. The nature of deep and shallow electron traps in the near-interfacial SiO{sub 2} is discussed.

  4. Packaging and Transportation Safety

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

    2010-05-14

    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. Supersedes DOE O 460.1B.

  5. Transportation Management Workshop: Proceedings

    SciTech Connect (OSTI)

    Not Available

    1993-10-01

    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.

  6. Transportation Energy Futures Study

    Broader source: Energy.gov [DOE]

    Transportation accounts for 71% of total U.S. petroleum consumption and 33% of total greenhouse gas emissions. The Transportation Energy Futures (TEF) study examines underexplored oil-savings and...

  7. Packaging and Transportation Safety

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

    1995-09-27

    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

  8. Packaging and Transportation Safety

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

    1995-09-27

    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

  9. Packaging and Transportation Safety

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

    1996-10-02

    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.

  10. 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 ...

  11. NREL: Innovation Impact - Transportation

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

    Transportation Menu Home Home Solar Solar Wind Wind Analysis Analysis Bioenergy Bioenergy Buildings Buildings Transportation Transportation Manufacturing Manufacturing Energy Systems Integration Energy Systems Integration Improved transportation technologies are essential for reducing U.S. petroleum dependence. Close The United States consumes roughly 19 million barrels of petroleum per day, but replacing petroleum-based liquid fuels is difficult because of their high energy density, which helps

  12. MECS 2006- Transportation Equipment

    Office of Energy Efficiency and Renewable Energy (EERE)

    Manufacturing Energy and Carbon Footprint for Transportation Equipment (NAICS 336) Sector with Total Energy Input, October 2012 (MECS 2006)

  13. Transportation Storage Interface

    Office of Environmental Management (EM)

    of Future Extended Storage and Transportation Transportation-Storage Interface James Rubenstone Office of Nuclear Material Safety and Safeguards U.S. Nuclear Regulatory Commission National Transportation Stakeholders Forum May 2012 ♦ Knoxville, Tennessee Overview * Changing policy environment * Regulatory framework-current and future * Extended storage and transportation-technical information needs * Next Steps 2 Current Policy Environment * U.S. national policy for disposition of spent

  14. Inherent interface defects in thermal (211)Si/SiO{sub 2}:{sup 29}Si hyperfine interaction

    SciTech Connect (OSTI)

    Iacovo, Serena E-mail: andre.stesmans@fys.kuleuven.be; Stesmans, Andre E-mail: andre.stesmans@fys.kuleuven.be

    2014-10-21

    Low temperature electron spin resonance (ESR) studies were carried out on ‘higher index’ (211)Si/SiO{sub 2} interfaces thermally grown in the temperature range T{sub ox} = 400–1066°C. The data reveal the presence of two species of a P{sub b}-type interface defect, exhibiting a significant difference in defect density. On the basis of the pertinent ESR parameters and interface symmetry, the basic defect is typified as P{sub b0}{sup (211)}, close to the Pb0 center observed in standard (100)Si/SiO{sub 2}. The dominant type is found to pertain to defected Si atoms at (111)Si-face terraces with the dangling bond along the [111] direction at ∼19.5°C with the interface normal, these sites thus apparently predominantly accounting for interface mismatch adaptation. The total of the P{sub b}-type defect appearance clearly reflects the higher-index nature of the interface. It is found that T{sub ox} = 750°C is required to minimize the P{sub b0}{sup (211)} defect density through relaxation of the oxide (interface). Q-band ESR saturation spectroscopy reveals an anisotropic {sup 29}Si (nuclear spin I=1/2) hyperfine (hf) doublet associated with the central P{sub b0}{sup (211)} Zeeman signal, with hf parameters closest to those of the similar hf structure of the P{sub b0}{sup (110)} defect in thermal (110)Si/SiO{sub 2}, adducing independent support to the P{sub b0}{sup (211)} typification.

  15. Theoretical investigations of two Si-based spintronic materials...

    Office of Scientific and Technical Information (OSTI)

    Two Si-based spintronic materials, a Mn-Si digital ferromagnetic heterostructure (delta-layer of Mn doped in Si) with defects and dilutely doped Mnsub xSisub 1-x alloy are ...

  16. Theoretical investigations of two Si-based spintronic materials...

    Office of Scientific and Technical Information (OSTI)

    Title: Theoretical investigations of two Si-based spintronic materials Two Si-based spintronic materials, a Mn-Si digital ferromagnetic heterostructure (delta-layer of Mn doped ...

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

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

    This is the May 2015 issue of the Transportation and Hydrogen Newsletter. May 28, 2015 Photo of a car refueling at a hydrogen dispensing station. DOE's H2FIRST project focuses on ...

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

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

    Energy Storage This is the November 2015 issue of the Transportation and Hydrogen ... kind in the national lab system, and one of just a few to be found in the entire country. ...

  19. Si(hhm) surfaces: Templates for developing nanostructures

    SciTech Connect (OSTI)

    Bozhko, S. I. Ionov, A. M.; Chaika, A. N.

    2015-06-15

    The fabrication of ordered low-dimensional structures on clean and metal-atom-decorated stepped Si(557) and Si(556) surfaces is discussed. The formation conditions and atomic structure of regular step systems on clean Si(557) 7 × 7 and Si(556) 7 × 7 surfaces are studied. The atomic structure of stepped Si(hhm), Ag/Si(557), and Gd/Si(557) surfaces is studied using high-resolution scanning tunneling microscopy and low-energy electron diffraction. The possibility of fabricating 1D and 2D structures of gadolinium and silver atoms on the Si(557) surface is demonstrated.

  20. Enhancement and Suppression of Photocurrent in Si Photodiodes...

    Office of Scientific and Technical Information (OSTI)

    Enhancement and Suppression of Photocurrent in Si Photodiodes by Nanoparticles and ... Title: Enhancement and Suppression of Photocurrent in Si Photodiodes by Nanoparticles and ...

  1. Sustainable Investments Capital SI Capital | Open Energy Information

    Open Energy Info (EERE)

    Investments Capital SI Capital Jump to: navigation, search Name: Sustainable Investments Capital (SI Capital) Place: Barcelona, Spain Zip: 8021 Sector: Renewable Energy, Services...

  2. SiXtron Advanced Materials | Open Energy Information

    Open Energy Info (EERE)

    Materials Jump to: navigation, search Name: SiXtron Advanced Materials Place: Quebec, Canada Website: www.sixtronadvancedmaterials.c References: SiXtron Advanced Materials1...

  3. Transportation safety training

    SciTech Connect (OSTI)

    Jones, E.

    1990-01-01

    Over the past 25 years extensive federal legislation involving the handling and transport of hazardous materials/waste has been passed that has resulted in numerous overlapping regulations administered and enforced by different federal agencies. The handling and transport of hazardous materials/waste involves a significant number of workers who are subject to a varying degree of risk should an accident occur during handling or transport. Effective transportation training can help workers address these risks and mitigate them, and at the same time enable ORNL to comply with the federal regulations concerning the transport of hazardous materials/waste. This presentation will outline how the Environmental and Health Protection Division's Technical Resources and Training Section at the Oak Ridge National Laboratory, working with transportation and waste disposal personnel, have developed and implemented a comprehensive transportation safety training program to meet the needs of our workers while satisfying appropriate federal regulations. 8 refs., 3 tabs.

  4. A commentary on the 1995 DOT/NRC amendments to the U.S. nuclear transportation regulations

    SciTech Connect (OSTI)

    Grella, A.

    1996-07-01

    This article discusses the major revisions (1995 DOT/NRC ammendments) to the US Nuclear Transportation regulations and their probable impacts on transportation. Areas covered include the following: the LSA and SCO definitions and packaging; radiation protection programs; mandatory use of SI units; changes an additions to the table of A1/A2 radionuclide values; and additional type B package hypothetical accident parameters.

  5. Solute embrittlement of SiC

    SciTech Connect (OSTI)

    Enrique, Ral A., E-mail: enriquer@umich.edu [Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48103 (United States); Van der Ven, Anton, E-mail: avdv@engineering.ucsb.edu [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)

    2014-09-21

    The energies and stresses associated with the decohesion of ?-SiC in the presence of mobile Pd and Ag impurities are studied from first principles. Density functional theory calculations are parameterized with a generalized cohesive zone model and are analyzed within a thermodynamic framework that accounts for realistic boundary conditions in the presence of mobile impurities. We find that Pd impurities will embrittle SiC when Pd is in equilibrium with metallic Pd precipitates. Our thermodynamic analysis predicts that Pd embrittles SiC by substantially reducing the maximum stress of decohesion as a result of a phase transition between decohering planes involving an influx of Pd atoms. The methods presented in this work can be applied to study the thermodynamics of decohesion of SiC in other aggressive environments containing oxygen and water, for example, and yield environment dependent cohesive zone models for use in continuum approaches to study crack propagation and fracture.

  6. High-performance Si microwire photovoltaics

    SciTech Connect (OSTI)

    Kelzenberg, Michael D.; Turner-Evans, Daniel B.; Putnam, Morgan C.; Boettcher, Shannon W.; Briggs, Ryan M.; Baek, Jae Y.; Lewis, Nathan S.; Atwater, Harry A.

    2011-01-07

    Crystalline Si wires, grown by the vaporliquidsolid (VLS) process, have emerged as promising candidate materials for low-cost, thin-film photovoltaics. Here, we demonstrate VLS-grown Si microwires that have suitable electrical properties for high-performance photovoltaic applications, including long minority-carrier diffusion lengths (Ln>> 30 m) and low surface recombination velocities (S << 70 cms-1). Single-wire radial pn junction solar cells were fabricated with amorphous silicon and silicon nitride surface coatings, achieving up to 9.0% apparent photovoltaic efficiency, and exhibiting up to ~600 mV open-circuit voltage with over 80% fill factor. Projective single-wire measurements and optoelectronic simulations suggest that large-area Si wire-array solar cells have the potential to exceed 17% energy-conversion efficiency, offering a promising route toward cost-effective crystalline Si photovoltaics.

  7. Si Pro AS | Open Energy Information

    Open Energy Info (EERE)

    Pro AS Jump to: navigation, search Name: Si Pro AS Place: Glomfjord, Norway Zip: 8161 Product: Silicon recycler with facility in Singapore. Coordinates: 66.807991, 13.97315...

  8. EBS Radionuclide Transport Abstraction

    SciTech Connect (OSTI)

    J. Prouty

    2006-07-14

    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

  9. Roll Casting of Al-25%Si

    SciTech Connect (OSTI)

    Haga, Toshio [Osaka Institute of Technology, Omiya Asahiku Osaka city 535-8585 (Japan); Harada, Hideto [Graduate School of Osaka Institute of Technology, Omiya Asahiku Osaka city 535-8585 (Japan); Watari, Hisaki [Gunma University, Kiryu city, 376-8515 (Japan)

    2011-05-04

    Strip casting of Al-25%Si strip was tried using an unequal diameter twin roll caster. The diameter of the lower roll (large roll) was 1000 mm and the diameter of the upper roll (small roll) was 250 mm. Roll material was mild steel. The sound strip could be cast at the speeds ranging from 8 m/min to 12 m/min. The strip did not stick to the roll without the parting material. The primary Si, which existed at centre area of the thickness direction, was larger than that which existed at other area. The size of the primary Si was smaller than 0.2 mm. Eutectic Si was smaller 5 {mu}m. The as-cast strip was ranging from 2 mm to 3 mm thick and its width was 100 mm. The as-cast strip could be hot rolled down to 1 mm. The hot rolled strip was cold rolled. The primary Si became smaller and the pore occurred around the primary Si after the rolling.

  10. Transparent conductor-Si pillars heterojunction photodetector

    SciTech Connect (OSTI)

    Yun, Ju-Hyung; Kim, Joondong; Park, Yun Chang

    2014-08-14

    We report a high-performing heterojunction photodetector by enhanced surface effects. Periodically, patterned Si substrates were used to enlarge the photo-reactive regions and yield proportionally improved photo-responses. An optically transparent indium-tin-oxide (ITO) was deposited on a Si substrate and spontaneously formed an ITO/Si heterojunction. Due to an electrical conductive ITO film, ITO/Si heterojunction device can be operated at zero-bias, which effectively suppresses the dark current, resulting in better performances than those by a positive or a negative bias operation. This zero-bias operating heterojunction device exhibits a short response time (? 22.5?ms) due to the physical reaction to the incident light. We revealed that the location of the space charge region (SCR) is crucial for a specific photon-wavelength response. The SCR space has the highest collection efficiency of the photo-generated carriers. The photo-response can be maximized when we design the photodetector by superposing the SCR space over a corresponding photon-absorption length. The surface enhanced Si pillar devices significantly improved the photo-responses ratios from that of a planar Si device. According to this design scheme, a high photo-response ratio of 5560% was achieved at a wavelength of 600?nm. This surfaced-enhanced heterojunction design scheme would be a promising approach for various photoelectric applications.

  11. Performance Comparison Study of SiC and Si Technology for an IPM Drive System

    SciTech Connect (OSTI)

    Chinthavali, Madhu Sudhan; Otaduy, Pedro J; Ozpineci, Burak

    2010-01-01

    The impact of the new SiC material based devices on a full system needs to be evaluated in order to assess the benefits of replacing Silicon (Si) devices with WBG devices. In this paper the results obtained with a full-system model simulated for an aggressive US06 drive cycle are presented. The system model includes a motor/generator model and inverter loss model developed using actual measured data. The results provide an insight to the difference in performance of a permanent magnet traction drive system using SiC versus Si devices.

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

    SciTech Connect (OSTI)

    Moeen, M.; Salemi, A.; stling, 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)

    2013-12-16

    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 (22500??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.

  13. 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); Schnherr, 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)

    2015-01-01

    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.

  14. Spectroscopic ellipsometry on Si/SiO{sub 2}/graphene tri-layer system exposed to downstream hydrogen plasma: Effects of hydrogenation and chemical sputtering

    SciTech Connect (OSTI)

    Eren, Baran; Fu, Wangyang; Marot, Laurent Calame, Michel; Steiner, Roland; Meyer, Ernst

    2015-01-05

    In this work, the optical response of graphene to hydrogen plasma treatment is investigated with spectroscopic ellipsometry measurements. Although the electronic transport properties and Raman spectrum of graphene change after plasma hydrogenation, ellipsometric parameters of the Si/SiO2/graphene tri-layer system do not change. This is attributed to plasma hydrogenated graphene still being electrically conductive, since the light absorption of conducting 2D materials does not depend on the electronic band structure. A change in the light transmission can only be observed when higher energy hydrogen ions (30?eV) are employed, which chemically sputter the graphene layer. An optical contrast is still apparent after sputtering due to the remaining traces of graphene and hydrocarbons on the surface. In brief, plasma treatment does not change the light transmission of graphene; and when it does, this is actually due to plasma damage rather than plasma hydrogenation.

  15. Future of Transportation

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

    of Transportation In the coming decades, transportation in the U.S. is expected to change radically in response to environmental constraints, fluctuating oil availability and economic factors. Future Decision-Makers The transportation systems that emerge in the 21 st century will be defined largely by the choices, skills and imaginations of today's youth. Future Workforce As scientists and engineers, they will develop new vehicle and fuel technologies. As citizens, they will make decisions

  16. Intelligent Transportation Systems

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

    Intelligent Transportation Systems This email address is being protected from spambots. You need JavaScript enabled to view it. - TRACC Director Background The development and deployment of Intelligent Transportation Systems (ITS) in the United States is an effort of national importance. Through the use of advanced computing, control, and communication technologies, ITS promises to greatly improve the efficiency and safety of the existing surface transportation system and reduce the

  17. Fermilab | Visit Fermilab | Transportation

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

    Transportation Transportation to and from Chicago O'Hare Airport or Midway Airport is available by limousine, taxi or car rental. Transportation to and from the Geneva local commuter Metra train station on the Union Pacific West line is available by taxi or Pace Call-n-Ride. Car rental All of the usual rental companies (such as Hertz, Avis, Budget and National) are located at the airports. Limousine service Reservations for limousine service should be made in advance when possible. West Suburban

  18. Transportation | Argonne National Laboratory

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

    is vital to the development of next-generation vehicles. ... Our Transportation Technology R&D Center (TTRDC) brings ... which automatically calibrates itself to any mix of fuels. ...

  19. Transportation Energy Futures Snapshot

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

    modes, manage the demand for transportation, and shift the fuel mix to more sustainable sources necessary to reach these significant outcomes. Coordinating a...

  20. integrated-transportation-models

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

    support a wider application of integrated transportation models, especially focusing on travel demand and network ... irrevocable worldwide license in said article to ...

  1. Radioactive Material Transportation Practices

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

    2002-09-23

    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.

  2. Sustainable Transportation (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-09-01

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

  3. WASTE PACKAGE TRANSPORTER DESIGN

    SciTech Connect (OSTI)

    D.C. Weddle; R. Novotny; J. Cron

    1998-09-23

    The purpose of this Design Analysis is to develop preliminary design of the waste package transporter used for waste package (WP) transport and related functions in the subsurface repository. This analysis refines the conceptual design that was started in Phase I of the Viability Assessment. This analysis supports the development of a reliable emplacement concept and a retrieval concept for license application design. The scope of this analysis includes the following activities: (1) Assess features of the transporter design and evaluate alternative design solutions for mechanical components. (2) Develop mechanical equipment details for the transporter. (3) Prepare a preliminary structural evaluation for the transporter. (4) Identify and recommend the equipment design for waste package transport and related functions. (5) Investigate transport equipment interface tolerances. This analysis supports the development of the waste package transporter for the transport, emplacement, and retrieval of packaged radioactive waste forms in the subsurface repository. Once the waste containers are closed and accepted, the packaged radioactive waste forms are termed waste packages (WP). This terminology was finalized as this analysis neared completion; therefore, the term disposal container is used in several references (i.e., the System Description Document (SDD)) (Ref. 5.6). In this analysis and the applicable reference documents, the term ''disposal container'' is synonymous with ''waste package''.

  4. Transportation Energy Futures Snapshot

    Broader source: Energy.gov [DOE]

    This snapshot is a summary of the EERE reports that provide a detailed analysis of opportunities and challenges along the path to a more sustainable transportation energy future.

  5. UZ Colloid Transport Model

    SciTech Connect (OSTI)

    M. McGraw

    2000-04-13

    The UZ Colloid Transport model development plan states that the objective of this Analysis/Model Report (AMR) is to document the development of a model for simulating unsaturated colloid transport. This objective includes the following: (1) use of a process level model to evaluate the potential mechanisms for colloid transport at Yucca Mountain; (2) Provide ranges of parameters for significant colloid transport processes to Performance Assessment (PA) for the unsaturated zone (UZ); (3) Provide a basis for development of an abstracted model for use in PA calculations.

  6. Selective deposition of a crystalline Si film by a chemical sputtering...

    Office of Scientific and Technical Information (OSTI)

    Raman spectrum also suggested that Si relatedmore radicals (SiHsub 2, SiH, Si) with high reactivity contribute to the Si film formation. Simple model was derived as the ...

  7. 07%20SEATTLE%20Best%20Practices%20in%20Transportation%20Demand%20Management.pdf

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

    | Department of Energy 07%20SEATTLE%20Best%20Practices%20in%20Transportation%20Demand%20Management.pdf 07%20SEATTLE%20Best%20Practices%20in%20Transportation%20Demand%20Management.pdf 07%20SEATTLE%20Best%20Practices%20in%20Transportation%20Demand%20Management.pdf 07%20SEATTLE%20Best%20Practices%20in%20Transportation%20Demand%20Management.pdf (1003.86 KB) More Documents & Publications EA-1440-S-I: Mitigation Action Plan Completion Report U.S. Virgin Islands Transportation Petroleum

  8. Synthesis of micro-sized interconnected Si-C composites

    DOE Patents [OSTI]

    Wang, Donghai; Yi, Ran; Dai, Fang

    2016-02-23

    Embodiments provide a method of producing micro-sized Si--C composites or doped Si--C and Si alloy-C with interconnected nanoscle Si and C building blocks through converting commercially available SiO.sub.x (0

  9. Transport Version 3

    Energy Science and Technology Software Center (OSTI)

    2008-05-16

    The Transport version 3 (T3) system uses the Network News Transfer Protocol (NNTP) to move data from sources to a Data Reporisoty (DR). Interested recipients subscribe to newsgroups to retrieve data. Data in transport is protected by AES-256 and RSA cryptographic services provided by the external OpenSSL cryptographic libraries.

  10. Packaging and Transportation Safety

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

    2003-04-04

    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.

  11. Small-Angle Neutron Scattering Studies of a-Si:H and a-Si:D

    SciTech Connect (OSTI)

    Williamson, D. L.; Marr, D. W. M.; Nelson, B. P.; Iwaniczko, E.; Yang, J.; Yan, B.; Guha, S.

    2000-01-01

    The heterogeneity of hydrogen and deuterium on the nanometer scale has been probed by samll-angle neutron scattering (SANS) from a-Si:H and a-Si:D films. Films were depsoited by two techniques, plasma-enhanced chemical vapor deposition (PECVD) and hot-wire chemical vapor deposition (HWCVD) using conditions that yield high quality films and devices.

  12. Investigation of structural and electrical properties of flat a-Si/c-Si heterostructure fabricated by EBPVD technique

    SciTech Connect (OSTI)

    Demiro?lu, D.; Tatar, B.; Kazmanli, K.; Urgen, M.

    2013-12-16

    Flat amorphous silicon - crystal silicon (a-Si/c-Si) heterostructure were prepared by ultra-high vacuum electron beam evaporation technique on p-Si (111) and n-Si (100) single crystal substrates. Structural analyses were investigated by XRD, Raman and FEG-SEM analysis. With these analyses we determined that at the least amorphous structure shows modification but amorphous structure just protected. The electrical and photovoltaic properties of flat a-Si/c-Si heterojunction devices were investigated with current-voltage characteristics under dark and illumination conditions. Electrical properties of flat a-Si/c-Si heterorojunction; such as barrier height ?{sub B}, diode ideality factor ? were determined from current-voltage characteristics in dark conditions. These a-Si/c-Si heterostructure have good rectification behavior as a diode and exhibit high photovoltaic sensitivity.

  13. Texture of CoSi2 Films on Si(111) (110) and (001) Substrates

    SciTech Connect (OSTI)

    K De Keyser; C Detavernier; J Jordan-Sweet; C Lavoie

    2011-12-31

    Synchrotron radiation was used to study the texture of polycrystalline CoSi{sub 2} films that were formed by a solid-state reaction between a 30 nm Co film and Si(111), (110) and (001) substrates. All films were strongly textured, and several texture components were identified. We discuss the simultaneous occurrence of axiotaxy (i.e. alignment of lattice planes across the interface) and several different types of epitaxy in each of the films. Comparison of the different texture components observed on the three substrate orientations suggests a strong preference for the alignment of CoSi{sub 2}{l_brace}110{r_brace} planes in the film with Si{l_brace}110{r_brace} planes in the substrate, and twinning around Si[111] directions.

  14. Determination of active doping in highly resistive boron doped silicon nanocrystals embedded in SiO{sub 2} by capacitance voltage measurement on inverted metal oxide semiconductor structure

    SciTech Connect (OSTI)

    Zhang, Tian Puthen-Veettil, Binesh; Wu, Lingfeng; Jia, Xuguang; Lin, Ziyun; Yang, Terry Chien-Jen; Conibeer, Gavin; Perez-Wurfl, Ivan

    2015-10-21

    We investigate the Capacitance-Voltage (CV) measurement to study the electrically active boron doping in Si nanocrystals (ncSi) embedded in SiO{sub 2}. The ncSi thin films with high resistivity (200–400 Ω cm) can be measured by using an inverted metal oxide semiconductor (MOS) structure (Al/ncSi (B)/SiO{sub 2}/Si). This device structure eliminates the complications from the effects of lateral current flow and the high sheet resistance in standard lateral MOS structures. The characteristic MOS CV curves observed are consistent with the effective p-type doping. The CV modeling method is presented and used to evaluate the electrically active doping concentration. We find that the highly boron doped ncSi films have electrically active doping of 10{sup 18}–10{sup 19 }cm{sup −3} despite their high resistivity. The saturation of doping at about 1.4 × 10{sup 19 }cm{sup −3} and the low doping efficiency less than 5% are observed and discussed. The calculated effective mobility is in the order of 10{sup −3} cm{sup 2}/V s, indicating strong impurity/defect scattering effect that hinders carriers transport.

  15. Effect of carbon ion irradiation on Ag diffusion in SiC

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

    Leng, Bin; Ko, Hyunseok; Gerczak, Tyler J.; Deng, Jie; Giordani, Andrew J.; Hunter, Jerry L.; Morgan, Dane; Szlufarska, Izabela; Sridharan, Kumar

    2015-11-14

    Transport of Ag fission product through the silicon-carbide (SiC) diffusion barrier layer in TRISO fuel particles is of considerable interest given the application of this fuel type in high temperature gas-cooled reactor (HTGR) and other future reactor concepts. The reactor experiments indicate that radiation may play an important role in release of Ag; however so far the isolated effect of radiation on Ag diffusion has not been investigated in controlled laboratory experiments. In this study, we investigate the diffusion couples of Ag and polycrystalline 3C–SiC, as well as Ag and single crystalline 4H–SiC samples before and after irradiation with C2+more » ions. The diffusion couple samples were exposed to temperatures of 1500 °C, 1535 °C, and 1569 °C, and the ensuing diffusion profiles were analyzed by secondary ion mass spectrometry (SIMS). We found that diffusion coefficients calculated from these measurements indicate that Ag diffusion was greatly enhanced by carbon irradiation due to a combined effect of radiation damage on diffusion and the presence of grain boundaries in polycrystalline SiC samples.« less

  16. GaP/Si heterojunction Solar Cells

    SciTech Connect (OSTI)

    Saive, R.; Chen, C.; Emmer, H.; Atwater, H.

    2015-05-11

    Improving the efficiency of solar cells requires the introduction of novel device concepts. Recent developments have shown that in Si solar cell technology there is still room for tremendous improvement. Using the heterojunction with intrinsic thin layer (HIT) approach 25.6 % power conversion efficiency was achieved. However, a-Si as a window and passivation layer comes with disadvantages as a-Si shows low conductivity and high parasitic absorption. Therefore, it is likely that using a crystalline material as window layer with high band gab and high mobility can further improve efficiency. We have studied GaP grown by MOCVD on Si with (001) and (112) orientation. We obtained crystalline layers with carrier mobility around 100 cm2/Vs and which passivate Si as confirmed by carrier lifetime measurements. We performed band alignment studies by X-ray photoelectron spectroscopy yielding a valence band offset of 0.3 eV. Comparing this value with the Schottky-model leads to an interface dipole of 0.59 eV. The open circuit voltage increases with increasing doping and is consistent with the theoretical open circuit voltage deduced from work function difference and interface dipole. We obtain an open circuit voltage of 0.38 V for n-doped GaP with doping levels in the order of 10^17 1/cm^3. In our next steps we will increase the doping level further in order to gain higher open circuit voltage. We will discuss the implications of these findings for GaP/Si heterojunction solar cells.

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

    SciTech Connect (OSTI)

    Belianinov, Aleksey

    2012-04-04

    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.

  18. Comparison of the vacuum-ultraviolet radiation response of HfO{sub 2}/SiO{sub 2}/Si dielectric stacks with SiO{sub 2}/Si

    SciTech Connect (OSTI)

    Upadhyaya, G. S.; Shohet, J. L.

    2007-02-12

    Vacuum ultraviolet (vuv) emitted during plasma processing degrades dielectrics by generating electron-hole pairs. VUV-induced charging of SiO{sub 2}/p-Si and HfO{sub 2}/SiO{sub 2}/p-Si dielectric stacks are compared. For SiO{sub 2}/p-Si, charging is observed for photon energies >15 eV by ionization of dielectric atoms from photoinjected electrons. In HfO{sub 2}/SiO{sub 2}/p-Si, charging is observed for photon >10 eV and is due to ionization by photoinjected electrons and by H{sup +} trapping in the HfO{sub 2}/SiO{sub 2} bulk. Hydrogen appears during annealing at the Si-SiO{sub 2} interface forming Si-H, which, during irradiation, is depassivated by photoinjected electrons. The authors conclude that dielectric charging in thin oxides (<10 nm) occurs more easily in HfO{sub 2}/SiO{sub 2} than in SiO{sub 2}.

  19. Direct growth of graphene on Si(111)

    SciTech Connect (OSTI)

    Thanh Trung, Pham Joucken, Frdric; Colomer, Jean-Franois; Robert, Sporken; Campos-Delgado, Jessica; Raskin, Jean-Pierre; Hackens, Benot; Santos, Cristiane N.

    2014-06-14

    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.

  20. Unit cell of strained GeSi

    SciTech Connect (OSTI)

    Woicik, J.C.; Bouldin, C.E.; Miyano, K.E.; King, C.A.

    1997-06-01

    The local structure within the unit cell of strained-GeSi layers grown on Si(001) has been examined by polarization-dependent extended x-ray-absorption fine structure. First-neighbor bond lengths are found to deviate only slightly from their unstrained values; however, the distortion of the cubic-unit cell by strain leads to measurable polarization-dependent changes in first-shell coordination and second-shell distances. A unifying picture of bond lengths and elasticity in strained-layer semiconductors is presented. {copyright} {ital 1997} {ital The American Physical Society}

  1. Transportation for Lab Employees

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

    Transportation Transportation for Lab Employees Choose the transportation option that works best for you: car, rail, taxi or public transit Contact Us Email Getting to the Lab Whether it be for an interview or a day on the job, using the right map and directions will make your travel to the Lab much easier. Visit our Maps webpage for maps and directions on how to get to Los Alamos from various communities in Northern New Mexico. Commuting options Sixty-six percent of the Los Alamos workforce

  2. EBS Radionuclide Transport Abstraction

    SciTech Connect (OSTI)

    J.D. Schreiber

    2005-08-25

    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

  3. The Geography of Transport Systems-Maritime Transportation |...

    Open Energy Info (EERE)

    report Website: people.hofstra.edugeotransengch3enconc3ench3c4en.html Cost: Free Language: English References: Maritime Transportation1 "Maritime transportation, similar to...

  4. Accident resistant transport container

    DOE Patents [OSTI]

    Anderson, J.A.; Cole, K.K.

    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. Transportation Baseline Report

    SciTech Connect (OSTI)

    Fawcett, Ricky Lee; Kramer, George Leroy Jr.

    1999-12-01

    The National Transportation Program 1999 Transportation Baseline Report presents data that form a baseline to enable analysis and planning for future Department of Energy (DOE) Environmental Management (EM) waste and materials transportation. In addition, this Report provides a summary overview of DOEs projected quantities of waste and materials for transportation. Data presented in this report were gathered as a part of the IPABS Spring 1999 update of the EM Corporate Database and are current as of July 30, 1999. These data were input and compiled using the Analysis and Visualization System (AVS) which is used to update all stream-level components of the EM Corporate Database, as well as TSD System and programmatic risk (disposition barrier) information. Project (PBS) and site-level IPABS data are being collected through the Interim Data Management System (IDMS). The data are presented in appendices to this report.

  6. Accident resistant transport container

    DOE Patents [OSTI]

    Andersen, John A.; Cole, James K.

    1980-01-01

    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.

  7. Electron Heat Transport Measured

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

    Heat Transport Measured in a Stochastic Magnetic Field T. M. Biewer, * C. B. Forest, ... limit of s &29; 1, RR assumed the electron heat flux to be diffusive, obeying Fourier's ...

  8. Program Analyst (Transportation Safety)

    Broader source: Energy.gov [DOE]

    A successful candidate in this position will serve as a Program Analyst(Transportation Safety) supporting and advising management on safety and health matters for nuclear and non-nuclear activities.

  9. Transportation | Open Energy Information

    Open Energy Info (EERE)

    Data From AEO2011 report . Market Trends From 2009 to 2035, transportation sector energy consumption grows at an average annual rate of 0.6 percent (from 27.2 quadrillion Btu...

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

    SciTech Connect (OSTI)

    Azmy, Yousry

    2014-06-10

    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.

  11. 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.; Brau, J.E.; Frey, R.E.; Strom, D.; Breidenbach, M.; Freytag, D.; Haller, G.; Herbst, R.; Nelson, T.; Schier, S.; Schumm, B.; /UC, Santa Cruz

    2012-09-14

    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.

  12. Thermophysical and mechanical properties of SiC/SiC composites

    SciTech Connect (OSTI)

    Zinkle, S.J.; Snead, L.L.

    1998-09-01

    The key thermophysical and mechanical properties for SiC/SiC composites are summarized, including temperature-dependent tensile properties, elastic constants, thermal conductivity, thermal expansion, and specific heat. The effects of neutron irradiation on the thermal conductivity and dimensional stability (volumetric swelling, creep) of SiC is discussed. The estimated lower and upper temperatures limits for structural applications in high power density fusion applications are 400 and 1000 C due to thermal conductivity degradation and void swelling considerations, respectively. Further data are needed to more accurately determine these estimated temperature limits.

  13. NREL: Transportation Research - Capabilities

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

    Capabilities A Vision for Sustainable Transportation Line graph illustrating three pathways (biofuel, hydrogen, and electric vehicle) to reduce energy use and greenhouse gas emissions. Electric Vehicle Technologies & Targets 3-D illustration of electric car diagramming energy storage, power electronics, and climate control components. NREL uses 100% of its considerable transportation research, development, and deployment (RD&D) capabilities to pursue sustainable solutions that deliver

  14. NREL: Transportation Research - Projects

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

    Projects Illustration of aerodynamic light-, medium, and heavy-duty vehicles. NREL research helps optimize the energy efficiency of a wide range of vehicle technologies and applications. NREL's innovative transportation research, development, and deployment projects accelerate widespread adoption of high-performance, low-emission, energy-efficient passenger and freight vehicles, as well as alternative fuels and related infrastructure. The following NREL transportation projects are propelling

  15. Transportation fuels from wood

    SciTech Connect (OSTI)

    Baker, E.G.; Elliott, D.C.; Stevens, D.J.

    1980-01-01

    The various methods of producing transportation fuels from wood are evaluated in this paper. These methods include direct liquefaction schemes such as hydrolysis/fermentation, pyrolysis, and thermochemical liquefaction. Indirect liquefaction techniques involve gasification followed by liquid fuels synthesis such as methanol synthesis or the Fischer-Tropsch synthesis. The cost of transportation fuels produced by the various methods are compared. In addition, three ongoing programs at Pacific Northwest Laboratory dealing with liquid fuels from wood are described.

  16. Transportation Politics and Policy

    U.S. Energy Information Administration (EIA) Indexed Site

    Reducing Greenhouse Gas Emissions from U.S. Transportation Steven Plotkin, Argonne National Laboratory (co-author is David Greene of Oak Ridge) 2011 EIA Energy Conference May 26-27, 2011 Washington, DC Overview  Presentation based on recent report from the Pew Center on Global Climate Change  Task: Assess the potential to substantially reduce transportation's GHG emissions by 2035 & 2050.  Base Case: Annual Energy Outlook 2010 Reference Case, extended to 2050  Three scenarios

  17. Fluid transport container

    DOE Patents [OSTI]

    DeRoos, Bradley G.; Downing, Jr., John P.; Neal, Michael P.

    1995-01-01

    An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitment for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container.

  18. Tape transport mechanism

    DOE Patents [OSTI]

    Groh, Edward F.; McDowell, William; Modjeski, Norbert S.; Keefe, Donald J.; Groer, Peter

    1979-01-01

    A device is provided for transporting, in a stepwise manner, tape between a feed reel and takeup reel. An indexer moves across the normal path of the tape displacing it while the tape on the takeup reel side of the indexer is braked. After displacement, the takeup reel takes up the displaced tape while the tape on the feed reel side of the indexer is braked, providing stepwise tape transport in precise intervals determined by the amount of displacement caused by the indexer.

  19. Fluid transport container

    DOE Patents [OSTI]

    DeRoos, B.G.; Downing, J.P. Jr.; Neal, M.P.

    1995-11-14

    An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitting for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container. 13 figs.

  20. Transportation Data Archiving

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

    Transportation Data Archiving This email address is being protected from spambots. You need JavaScript enabled to view it. - TRACC Director Background Urban and regional transportation planning and operations applications, (e.g. traffic modeling) require a large volume of accurate traffic-related data for a wide range of conditions. Significant real-time data on traffic volumes, highway construction, accidents, weather, airline flights, commuter and rail schedules, etc., are recorded each day by

  1. Effect of exposure environment on surface decomposition of SiC-silver ion implantation diffusion couples

    SciTech Connect (OSTI)

    Gerczak, Tyler J.; Zheng, Guiqui; Field, Kevin G.; Allen, Todd R.

    2014-10-05

    SiC is a promising material for nuclear applications and is a critical component in the construction of tristructural isotropic (TRISO) fuel. A primary issue with TRISO fuel operation is the observed release of 110m Ag from intact fuel particles. The release of Ag has prompted research efforts to directly measure the transport mechanism of Ag in bulk SiC. Recent research efforts have focused primarily on Ag ion implantation designs. The effect of the thermal exposure system on the ion implantation surface has been investigated. Results indicate the utilization of a mated sample geometry and the establishment of a static thermal exposure environment is critical to maintaining an intact surface for diffusion analysis. In conclusion, the nature of the implantation surface and its potential role in Ag diffusion analysis are discussed.

  2. Effect of exposure environment on surface decomposition of SiC-silver ion implantation diffusion couples

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

    Gerczak, Tyler J.; Zheng, Guiqui; Field, Kevin G.; Allen, Todd R.

    2014-10-05

    SiC is a promising material for nuclear applications and is a critical component in the construction of tristructural isotropic (TRISO) fuel. A primary issue with TRISO fuel operation is the observed release of 110m Ag from intact fuel particles. The release of Ag has prompted research efforts to directly measure the transport mechanism of Ag in bulk SiC. Recent research efforts have focused primarily on Ag ion implantation designs. The effect of the thermal exposure system on the ion implantation surface has been investigated. Results indicate the utilization of a mated sample geometry and the establishment of a static thermalmore » exposure environment is critical to maintaining an intact surface for diffusion analysis. In conclusion, the nature of the implantation surface and its potential role in Ag diffusion analysis are discussed.« less

  3. Transportation and Program Management Services

    Office of Environmental Management (EM)

    Atlanta, Georgia Transportation and Program Management Services Secured Transportation Services, LLC Founded: December, 2003 ff Staff: 7 Experience: Over 145 years combined experience in Nuclear Transportation, Security, HP & Operations Services Transportation The largest Transportation Coordinators of Spent Nuclear Fuel in North America On-Site, Hands-On Assistance (Before & During both Loading & Transport) P d A i t (W iti d/ R i ) Procedure Assistance (Writing and/or Review)

  4. Porous Si structure as moisture sensor

    SciTech Connect (OSTI)

    Peterson, D.W.; Nguyen, L.T.

    1996-12-31

    Development and characterization of a capacitive moisture sensor made from porous Si is presented. The sensor development was in support of the DoD funded Plastic Package Availability program and was intended for the detection of pinholes and defects in moisture barrier coatings applied to ICs during fabrication or during the plastic encapsulation assembly process.

  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. Washington: Integrated Transportation Programs & Coordinated...

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

    Integrated Transportation Programs & Coordinated Regional Planning Washington: Integrated Transportation Programs & Coordinated Regional Planning November 6, 2013 - 5:42pm Addthis ...

  7. Sustainable Transportation - Continuum Magazine | NREL

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

    A Closer Look Slideshow: Sustainable Transportation NREL research, development, and ... Continuum Sustainable Transportation Fall 2013 Issue 5 Download the print version. RSS ...

  8. Badger Transport | Open Energy Information

    Open Energy Info (EERE)

    Transport Jump to: navigation, search Name: Badger Transport Place: Clintonville, Wisconsin Zip: 54929 Product: Heavy haul and specialty trucking company active in the US Midwest....

  9. Implementing Advances in Transport Security Technologies | Department...

    Office of Environmental Management (EM)

    Implementing Advances in Transport Security Technologies Implementing Advances in Transport Security Technologies Implementing Advances in Transport Security Technologies More...

  10. California Department of Transportation | Open Energy Information

    Open Energy Info (EERE)

    Transportation Jump to: navigation, search Name: California Department of Transportation Place: Sacramento, California References: California Department of Transportation1 This...

  11. Spring 2016 National Transportation Stakeholders Forum Meeting...

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

    6 National Transportation Stakeholders Forum Meeting, Florida Spring 2016 National Transportation Stakeholders Forum Meeting, Florida Spring 2016 National Transportation ...

  12. National Transportation Stakeholders Forum (NTSF) Charter | Department...

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

    Services Waste Management Packaging and Transportation National Transportation Stakeholders Forum National Transportation Stakeholders Forum (NTSF) Charter National ...

  13. Spring 2015 National Transportation Stakeholders Forum Meeting...

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

    Transportation Stakeholders Forum Meeting, New Mexico Spring 2015 National Transportation Stakeholders Forum Meeting, New Mexico Spring 2015 National Transportation Stakeholders ...

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

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

    Market Impact Hydrogen Fuel Cells This is the July 2016 issue of the Transportation and Hydrogen Newsletter. July 28, 2016 A photo of a public hydrogen fuel cell bus parked in a parking lot. Fuel cell electric buses (FCEBs), such as this one operating in Oakland, California, are providing data to compare FCEB performance with that of buses using conventional technology. Photo by Leslie Eudy, NREL NREL Helps Pave Way for H2 Technologies As deployment of hydrogen fueling stations increases to

  15. Current Status and Recent Research Achievements in SiC/SiC Composites

    SciTech Connect (OSTI)

    Katoh, Yutai; Snead, Lance L.; Henager, Charles H.; Nozawa, T.; Hinoki, Tetsuya; Ivekovic, Aljaz; Novak, Sasa; Gonzalez de Vicente, Sehila M.

    2014-12-01

    The development and maturation of the silicon carbide fiber-reinforced silicon carbide matrix (SiC/SiC) composite system for fusion applications has seen the evolution from fundamental development and understanding of the material system and its behavior in a hostile irradiation environment to the current effort which essentially is a broad-based program of technology, directed at moving this material class from a laboratory curiosity to an engineering material. This paper lays out the recent international scientific and technological achievements in the development of SiC/SiC composite material technologies for fusion application and will discuss future research directions. It also reviews the materials system in the larger context of progress to maturity as an engineering material for both the larger nuclear community and for general engineering applications.

  16. Ni-Si Alloys for the S-I Reactor-Hydrogen Production Process Interface

    SciTech Connect (OSTI)

    Joseph W. Newkirk; Richard K. Brow

    2010-01-21

    The overall goal of this project was to develop Ni-Si alloys for use in vessels to contain hot, pressurized sulfuric acid. The application was to be in the decomposition loop of the thermochemical cycle for production of hydrogen.

  17. Transportation Anslysis Simulation System

    Energy Science and Technology Software Center (OSTI)

    2004-08-23

    TRANSIMS version 3.1 is an integrated set of analytical and simulation models and supporting databases. The system is designed to create a virtual metropolitan region with representation of each of the region’s individuals, their activities and the transportation infrastructure they use. TRANSIMS puts into practice a new, disaggregate approach to travel demand modeling using agent-based micro-simulation technology. TRANSIMS methodology creates a virtual metropolitan region with representation of the transportation infrastructure and the population, at themore » level of households and individual travelers. Trips a planned to satisfy the population’s activity pattems at the individual traveler level. TRANSIMS then simulates the movement of travelers and vehicles across the transportation network using multiple modes, including car, transit, bike and walk, on a second-by-second basis. Metropolitan planners must plan growth of their cities according to the stringent transportation system planning requirements of the Interniodal Surface Transportation Efficiency Act of 1991, the Clean Air Act Amendments of 1990 and other similar laws and regulations. These require each state and its metropotitan regions to work together to develop short and long term transportation improvement plans. The plans must (1) estimate the future transportation needs for travelers and goods movements, (2) evaluate ways to manage and reduce congestion, (3) examine the effectiveness of building new roads and transit systems, and (4) limit the environmental impact of the various strategies. The needed consistent and accurate transportation improvement plans require an analytical capability that properly accounts for travel demand, human behavior, traffic and transit operations, major investments, and environmental effects. Other existing planning tools use aggregated information and representative behavior to predict average response and average use of transportation facilities. They do not

  18. Silicon Genesis Corp SiGen | Open Energy Information

    Open Energy Info (EERE)

    Corp SiGen Jump to: navigation, search Name: Silicon Genesis Corp (SiGen) Place: San Jose, California Zip: 95134 Product: US-based manufacturer of proton-shooting wafer slicing...

  19. SiC Processing AG | Open Energy Information

    Open Energy Info (EERE)

    SiC Processing AG Jump to: navigation, search Name: SiC Processing AG Place: Hirschau, Germany Zip: 92242 Sector: Solar Product: Offers management and recycling of slurry for solar...

  20. SiG Solar GmbH | Open Energy Information

    Open Energy Info (EERE)

    SiG Solar GmbH Jump to: navigation, search Name: SiG Solar GmbH Place: Stuhr-Brinkum, Germany Zip: 28816 Sector: Solar Product: Supplier of mounting systems, and trade name in...

  1. SEGR in SiO$${}_2$$ –Si$_3$ N$_4$ Stacks

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

    Javanainen, Arto; Ferlet-Cavrois, Veronique; Bosser, Alexandre; Jaatinen, Jukka; Kettunen, Heikki; Muschitiello, Michele; Pintacuda, Francesco; Rossi, Mikko; Schwank, James R.; Shaneyfelt, Marty R.; et al

    2014-04-17

    This work presents experimental SEGR data for MOS-devices, where the gate dielectrics are are made of stacked SiO2–Si3N4 structures. Also a semi-empirical model for predicting the critical gate voltage in these structures under heavy-ion exposure is proposed. Then statistical interrelationship between SEGR cross-section data and simulated energy deposition probabilities in thin dielectric layers is discussed.

  2. Water Transport Within the STack: Water Transport Exploratory Studies |

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

    Department of Energy 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 Secretary Bodman on Oct. 25, 2006. 2_lanl.pdf (22.05 KB) More Documents & Publications Water Transport Exploratory Studies Fuel Cell Kickoff Meeting Agenda

  3. SiN-SiC nanofilm: A nano-functional ceramic with bipolar magnetic semiconducting character

    SciTech Connect (OSTI)

    Zhang, Jiahui; Li, Xingxing; Yang, Jinlong

    2014-04-28

    Nowadays, functional ceramics have been largely explored for application in various fields. However, magnetic functional ceramics for spintronics remain little studied. Here, we propose a nano-functional ceramic of sphalerite SiN-SiC nanofilm with intrinsic ferromagnetic order. Based on first principles calculations, the SiN-SiC nanofilm is found to be a ferromagnetic semiconductor with an indirect band gap of 1.71 eV. By mean field theory, the Curie temperature is estimated to be 304 K, close to room temperature. Furthermore, the valence band and conduction band states of the nanofilm exhibit inverse spin-polarization around the Fermi level. Thus, the SiN-SiC nanofilm is a typical bipolar magnetic semiconductor in which completely spin-polarized currents with reversible spin polarization can be created and controlled by applying a gate voltage. Such a nano-functional ceramic provides a possible route for electrical manipulation of carrier's spin orientation.

  4. Nanocrystalline SiC formed by annealing of a-SiC:H on Si substrates: A study of dopant interdiffusion

    SciTech Connect (OSTI)

    Schnabel, Manuel; Weiss, Charlotte; Löper, Philipp; Janz, Stefan; Canino, Mariaconcetta; Summonte, Caterina; Wilshaw, Peter R.

    2014-07-14

    Nanocrystalline silicon carbide (nc-SiC) is an interesting material for electronics applications, both in its own right and as a host matrix for silicon quantum dots. When synthesized by annealing of a-SiC:H on Si substrates, interdiffusion of dopants occurs if either the a-SiC:H or the Si substrate is doped. Annealing a-SiC:H on highly boron-doped substrates at 1100 °C leads to a fairly homogeneous doping level of ≥4 × 10{sup 19} cm{sup −3} throughout the nc-SiC film. An unexpected anomaly in secondary ion mass spectroscopy quantification is observed and a method to circumvent it is shown. The nanostructure of the nc-SiC is only weakly affected as most of the diffusion occurs after the onset of crystallization. Annealing of doped a-SiC:H on Si substrates at 1100 °C leads to strong free carrier absorption at infrared wavelengths. This is demonstrated to originate from dopants that have diffused from the a-SiC:H to the Si substrate, and a method is developed to extract from it the doping profile in the Si substrate. The detection limit of this method is estimated to be ≤6 × 10{sup 13} cm{sup −2}. Doping levels of (0.5–3.5) × 10{sup 19} cm{sup −3} are induced at the Si substrate surface by both boron and phosphorus-doped a–SiC:H. When the Si substrate is doped opposite to the a-SiC:H p–n junctions are induced at a depth of 0.9–1.4 μm within the Si substrate for substrate resistivities of 1–10 Ω cm. Implications for different solar cell architectures are discussed. Dopant diffusion can be strongly reduced by lowering the annealing temperature to 1000 °C, albeit at the expense of reduced crystallinity.

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

    SciTech Connect (OSTI)

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

    2014-09-22

    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.

  6. Investigation of the physical properties of the tetragonal CeMAl4Si2 (M = Rh, Ir, Pt) compounds

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

    Ghimire, N. J.; Ronning, F.; Williams, D. J.; Scott, B. L.; Luo, Yongkang; Thompson, J. D.; Bauer, E. D.

    2014-12-15

    The synthesis, crystal structure and physical properties studied by means of x-ray diffraction, magnetic, thermal and transport measurements of CeMAl4Si2 (M = Rh, Ir, Pt) are reported, along with the electronic structure calculations for LaMAl4Si2 (M = Rh, Ir, Pt). These materials adopt a tetragonal crystal structure (space group P4/mmm) comprised of BaAl4 blocks, separated by MAl2 units, stacked along the c-axis. Both CeRhAl4Si2 and CeIrAl4Si2 order antiferromagnetically below TN1 = 14 and 16 K, respectively, and undergo a second antiferromagnetic transitition at lower temperature (TN2 = 9 and 14 K, respectively). CePtAl4Si2 orders ferromagnetically below TC = 3 Kmore » with an ordered moment of μsat = 0.8 μB for a magnetic field applied perpendicular to the c-axis. Electronic structure calculations reveal quasi-2D character of the Fermi surface.« less

  7. Real time nanoscale structural evaluation of gold structures on Si (100) surface using in-situ transmission electron microscopy

    SciTech Connect (OSTI)

    Rath, A. E-mail: ashutosh.phy@gmail.com E-mail: pvsatyam22@gmail.com; Juluri, R. R.; Satyam, P. V. E-mail: ashutosh.phy@gmail.com E-mail: pvsatyam22@gmail.com

    2014-05-14

    Transport behavior of gold nanostructures on Si(100) substrate during annealing under high vacuum has been investigated using in-situ real time transmission electron microscopy (TEM). A comparative study has been done on the morphological changes due to annealing under different vacuum environments. Au thin films of thickness ∼2.0 nm were deposited on native oxide covered silicon substrate by using thermal evaporation system. In-situ real time TEM measurements at 850 °C showed the isotropic growth of rectangular/square shaped gold-silicon alloy structures. During the growth, it is observed that the alloying occurs in liquid phase followed by transformation into the rectangular shapes. For similar system, ex-situ annealing in low vacuum (10{sup −2} millibars) at 850 °C showed the spherical gold nanostructures with no Au-Si alloy formation. Under low vacuum annealing conditions, the rate of formation of the oxide layer dominates the oxide desorption rate, resulting in the creation of a barrier layer between Au and Si, which restricts the inter diffusion of Au in to Si. This work demonstrates the important role of interfacial oxide layer on the growth of nanoscale Au-Si alloy structures during the initial growth. The time dependent TEM images are presented to offer a direct insight into the fundamental dynamics of the sintering process at the nanoscale.

  8. Thermal stability of Ni/Ti/Al ohmic contacts to p-type 4H-SiC

    SciTech Connect (OSTI)

    Yu, Hailong; Shen, Huajun Tang, Yidan; Bai, Yun; Liu, Xinyu; Zhang, Xufang; Wu, Yudong; Liu, Kean

    2015-01-14

    Low resistivity Ni/Ti/Al ohmic contacts on p-type 4H-SiC epilayer were developed, and their thermal stabilities were also experimentally investigated through high temperature storage at 600 °C for 100 h. The contact resistance of the Al/Ti/Ni/SiC contacts degraded in different degrees, and the contact morphology deteriorated with the increases of the average surface roughness and interface voids. X-ray spectra showed that Ni{sub 2}Si and Ti{sub 3}SiC{sub 2}, which were formed during ohmic contact annealing and contributed to low contact resistivity, were stable under high temperature storage. The existence of the TiAl{sub 3} and NiAl{sub 3} intermetallic phases was helpful to prevent Al agglomeration on the interface and make the contacts thermally stable. Auger electron spectroscopy indicated that the incorporation of oxygen at the surface and interface led to the oxidation of Al or Ti resulting in increased contact resistance. Also, the formation of these oxides roughened the surface and interface. The temperature-dependence of the specific contact resistance indicated that a thermionic field emission mechanism dominates the current transport for contacts before and after the thermal treatment. It suggests that the Ni/Ti/Al composite ohmic contacts are promising for SiC devices to be used in high temperature applications.

  9. 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)

    2014-09-28

    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.

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

    DOE Patents [OSTI]

    Holland, Orin W.; Fathy, Dariush; White, Clark W.

    1990-04-24

    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.

  11. Chapter 17 - Transportation

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

    8,2005 MEMORANDUM FOR FROM: SUBJECT: Accounting Handbook - Chapter 1 7, Transportation Attached is the final version of Chapter 17, "Transportation," of the Department's Accounting Handbook. A draft version of this chapter was circulated for review and comment in a November 1,2004, memorandum "Request for Review of D r a f t DOE Accounting Handbook Chapter 17." There were no comments on this chapter. We appreciate your assistance in the update of the Accounting Handbook. When

  12. CASL - Radiation Transport Methods Update

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

    Radiation Transport Methods Update The Radiation Transport Methods (RTM) focus area is responsible for the development of methods, algorithms, and implementations of radiation transport methods as they apply to the design and analysis of light water nuclear reactors. the fundamental areas of investigation in RTM include high-order deterministic transport low-order transport approximations multigroup cross section generation depletion as it applies to in-core neutronics and material coupling

  13. 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

    2005-01-01

    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.

  14. Magnetoelasticity of Fe-Si single crystals

    SciTech Connect (OSTI)

    Xing, Q; Wu, D.; Lograsso, T. A.

    2010-04-20

    The tetragonal magnetostriction constant, (3/2){lambda}{sub 100}, of Fe-Si single crystals was measured and was found to be structure dependent. Similar to that of Fe-Ge single crystals, (3/2){lambda}{sub 100} is positive in the single phase A2 regime, becomes negative in the single phase D0{sub 3} regime, and changes from positive to negative between the two regimes. Short-range order in the A2 regime decreases the magnetostriction prior to the onset of long range order. In the single phase regions of both A2 and D0{sub 3}, thermal history does not show any obvious effect on the magnetostriction, contrary to that found for Fe-Ga alloys. However, in the regions of phase mixture involving A2, B2, and D0{sub 3} phases, quenching pushes the change in magnetostriction from positive to negative to higher Si contents.

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

    SciTech Connect (OSTI)

    Dedyulin, Sergey N. Goncharova, Lyudmila V.

    2014-03-24

    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?=?450650?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.

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

    SciTech Connect (OSTI)

    Teplin, C.

    2013-04-01

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

  17. NREL: Transportation Research - Webmaster

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

    Webmaster Please enter your name and email address in the boxes provided, then type your message below. When you are finished, click "Send Message." NOTE: If you enter your e-mail address incorrectly, we will be unable to reply. Your name: Your email address: Your message: Send Message Printable Version Transportation Research Home Capabilities Projects

  18. EPAct Transportation Regulatory Activities

    SciTech Connect (OSTI)

    2011-11-21

    The U.S. Department of Energy's (DOE) Vehicle Technologies Program manages several transportation regulatory activities established by the Energy Policy Act of 1992 (EPAct), as amended by the Energy Conservation Reauthorization Act of 1998, EPAct 2005, and the Energy Independence and Security Act of 2007 (EISA).

  19. Artificial oxygen transport protein

    DOE Patents [OSTI]

    Dutton, P. Leslie

    2014-09-30

    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.

  20. Storing and transporting energy

    DOE Patents [OSTI]

    McClaine, Andrew W.; Brown, Kenneth

    2010-09-07

    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.

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

    SciTech Connect (OSTI)

    Isabella Van Rooyen

    2014-10-01

    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.

  2. Saturated Zone Colloid Transport

    SciTech Connect (OSTI)

    H. S. Viswanathan

    2004-10-07

    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

  3. Initial assessment of environmental effects on SiC/SiC composites in helium-cooled nuclear systems

    SciTech Connect (OSTI)

    Contescu, Cristian I

    2013-09-01

    This report summarized the information available in the literature on the chemical reactivity of SiC/SiC composites and of their components in contact with the helium coolant used in HTGR, VHTR and GFR designs. In normal operation conditions, ultra-high purity helium will have chemically controlled impurities (water, oxygen, carbon dioxide, carbon monoxide, methane, hydrogen) that will create a slightly oxidizing gas environment. Little is known from direct experiments on the reactivity of third generation (nuclear grade) SiC/SiC composites in contact with low concentrations of water or oxygen in inert gas, at high temperature. However, there is ample information about the oxidation in dry and moist air of SiC/SiC composites at high temperatures. This information is reviewed first in the next chapters. The emphasis is places on the improvement in material oxidation, thermal, and mechanical properties during three stages of development of SiC fibers and at least two stages of development of the fiber/matrix interphase. The chemical stability of SiC/SiC composites in contact with oxygen or steam at temperatures that may develop in off-normal reactor conditions supports the conclusion that most advanced composites (also known as nuclear grade SiC/SiC composites) have the chemical resistance that would allow them maintain mechanical properties at temperatures up to 1200 1300 oC in the extreme conditions of an air or water ingress accident scenario. Further research is needed to assess the long-term stability of advanced SiC/SiC composites in inert gas (helium) in presence of very low concentrations (traces) of water and oxygen at the temperatures of normal operation of helium-cooled reactors. Another aspect that needs to be investigated is the effect of fast neutron irradiation on the oxidation stability of advanced SiC/SiC composites in normal operation conditions.

  4. 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.

    2014-05-01

    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.

  5. Si etching with reactive neutral beams of very low energy

    SciTech Connect (OSTI)

    Hara, Yasuhiro; Hamagaki, Manabu; Mise, Takaya; Iwata, Naotaka; Hara, Tamio

    2014-12-14

    A Si etching process has been investigated with reactive neutral beams (NBs) extracted using a low acceleration voltage of less than 100 V from CF{sub 4} and Ar mixed plasmas. The etched Si profile shows that the etching process is predominantly anisotropic. The reactive NB has a constant Si etching rate in the acceleration voltage range from 20 V to 80 V. It is considered that low-energy NBs can trigger Si etching because F radicals adsorb onto the Si surface and weaken Si–Si bonds. The etching rate per unit beam flux is 33 times higher than that with Ar NB. These results show that the low-energy reactive NB is useful for damage-free high speed Si etching.

  6. Light emission from Si nanoclusters formed at low temperatures

    SciTech Connect (OSTI)

    Pi, X.D.; Zalloum, O.H.Y.; Roschuk, T.; Wojcik, J.; Knights, A.P.; Mascher, P.; Simpson, P.J.

    2006-03-06

    Photoluminescence (PL) from amorphous Si nanoclusters (Si-ncls) formed by thin-film deposition via electron-cyclotron resonance plasma-enhanced chemical vapor deposition followed by annealing at temperatures {<=}875 deg. C has been investigated. We find that Si-ncls grow very slowly after their initial nucleation at low temperatures. An increase in the size of Si-ncls, which can be controlled by the annealing temperature, induces a redshift in the Si-ncl PL peak. While the emitted optical power is more than 100 times smaller than that of Si nanocrystals formed in an identically deposited film, it is increased by a factor of up to approximately four times following hydrogen passivation. The incorporation of hydrogen causes a redshift in the PL peak position, suggesting a partial hydrogenation induced bond distortion of the Si-ncls. This redshift decreases with increasing hydrogen ambient annealing temperature.

  7. 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

    2015-02-05

    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

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

    SciTech Connect (OSTI)

    Tsui, Daniel

    2014-03-24

    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.

  9. Effects of inter-nanocrystal distance on luminescence quantum yield in ensembles of Si nanocrystals

    SciTech Connect (OSTI)

    Valenta, J. Greben, M.; Gutsch, S.; Hiller, D.; Zacharias, M.

    2014-12-15

    The absolute photoluminescence (PL) quantum yield (QY) of multilayers of Silicon nanocrystals (SiNCs) separated by SiO{sub 2} barriers were thoroughly studied as function of the barrier thickness, excitation wavelength, and temperature. By mastering the plasma-enhanced chemical vapor deposition growth, we produce a series of samples with the same size-distribution of SiNCs but variable interlayer barrier distance. These samples enable us to clearly demonstrate that the increase of barrier thickness from ∼1 to larger than 2 nm induces doubling of the PL QY value, which corresponds to the change of number of close neighbors in the hcp structure. The temperature dependence of PL QY suggests that the PL QY changes are due to a thermally activated transport of excitation into non-radiative centers in dark NCs or in the matrix. We estimate that dark NCs represent about 68% of the ensemble of NCs. The PL QY excitation spectra show no significant changes upon changing the barrier thickness and no clear carrier multiplication effects. The dominant effect is the gradual decrease of the PL QY with increasing excitation photon energy.

  10. Oxidation-resistant interface coatings for SiC/SiC composites

    SciTech Connect (OSTI)

    Stinton, D.P.; Kupp, E.R.; Hurley, J.W.

    1996-06-01

    The characteristics of the fiber-matrix interfaces in ceramic matrix composites control the mechanical behavior of these composites. Finite element modeling (FEM) was performed to examine the effect of interface coating modulus and coefficient of thermal expansion on composite behavior. Oxide interface coatings (mullite and alumina-titania) produced by a sol-gel method were chosen for study as a result of the FEM results. Amorphous silicon carbide deposited by chemical vapor deposition (CVD) is also being investigated for interface coatings in SiC-matrix composites. Processing routes for depositing coatings of these materials were developed. Composites with these interfaces were produced and tested in flexure both as-processed and after oxidation to examine the suitability of these materials as interface coatings for SiC/SiC composites in fossil energy applications.

  11. Si/SiGe electron resonant tunneling diodes with graded spacer wells

    SciTech Connect (OSTI)

    Paul, D. J.; See, P.; Bates, R.; Griffin, N.; Coonan, B. P.; Redmond, G.; Crean, G. M.; Zozoulenko, I. V.; Berggren, K.-F.; Hollander, B.

    2001-06-25

    Resonant tunneling diodes have been fabricated using graded Si{sub 1{minus}x}Ge{sub x} (x=0.3{r_arrow}0.0) spacer wells and strained Si{sub 0.4}Ge{sub 0.6} barriers on a relaxed Si{sub 0.7}Ge{sub 0.3} n-type substrate which demonstrates negative differential resistance at up to 100 K. This design is aimed at reducing the voltage at which the peak current density is achieved. Peak current densities of 0.08A/cm{sup 2} with peak-to-valley current ratios of 1.67 have been achieved for a low peak voltage of 40 mV at 77 K. This represents an improvement of over an order of magnitude compared to previous work. {copyright} 2001 American Institute of Physics.

  12. Tin induced a-Si crystallization in thin films of Si-Sn alloys

    SciTech Connect (OSTI)

    Neimash, V. E-mail: oleks.goushcha@nuportsoft.com; Poroshin, V.; Goushcha, A. O. E-mail: oleks.goushcha@nuportsoft.com; Shepeliavyi, P.; Yukhymchuk, V.; Melnyk, V.; Kuzmich, A.; Makara, V.

    2013-12-07

    Effects of tin doping on crystallization of amorphous silicon were studied using Raman scattering, Auger spectroscopy, scanning electron microscopy, and X-ray fluorescence techniques. Formation of silicon nanocrystals (24?nm in size) in the amorphous matrix of Si{sub 1?x}Sn{sub x}, obtained by physical vapor deposition of the components in vacuum, was observed at temperatures around 300?C. The aggregate volume of nanocrystals in the deposited film of Si{sub 1?x}Sn{sub x} exceeded 60% of the total film volume and correlated well with the tin content. Formation of structures with ?80% partial volume of the nanocrystalline phase was also demonstrated. Tin-induced crystallization of amorphous silicon occurred only around the clusters of metallic tin, which suggested the crystallization mechanism involving an interfacial molten Si:Sn layer.

  13. Mass Transport within Soils

    SciTech Connect (OSTI)

    McKone, Thomas E.

    2009-03-01

    Contaminants in soil can impact human health and the environment through a complex web of interactions. Soils exist where the atmosphere, hydrosphere, geosphere, and biosphere converge. Soil is the thin outer zone of the earth's crust that supports rooted plants and is the product of climate and living organisms acting on rock. A true soil is a mixture of air, water, mineral, and organic components. The relative proportions of these components determine the value of the soil for agricultural and for other human uses. These proportions also determine, to a large extent, how a substance added to soil is transported and/or transformed within the soil (Spositio, 2004). In mass-balance models, soil compartments play a major role, functioning both as reservoirs and as the principal media for transport among air, vegetation, surface water, deeper soil, and ground water (Mackay, 2001). Quantifying the mass transport of chemicals within soil and between soil and atmosphere is important for understanding the role soil plays in controlling fate, transport, and exposure to multimedia pollutants. Soils are characteristically heterogeneous. A trench dug into soil typically reveals several horizontal layers having different colors and textures. As illustrated in Figure 1, these multiple layers are often divided into three major horizons: (1) the A horizon, which encompasses the root zone and contains a high concentration of organic matter; (2) the B horizon, which is unsaturated, lies below the roots of most plants, and contains a much lower organic carbon content; and (3) the C horizon, which is the unsaturated zone of weathered parent rock consisting of bedrock, alluvial material, glacial material, and/or soil of an earlier geological period. Below these three horizons lies the saturated zone - a zone that encompasses the area below ground surface in which all interconnected openings within the geologic media are completely filled with water. Similarly to the unsaturated zone

  14. Thermal conductivity in nanocrystalline-SiC/C superlattices

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

    Habermehl, S.; Serrano, J. R.

    2015-11-17

    We reported the formation of thin film superlattices consisting of alternating layers of nitrogen-doped SiC (SiC:N) and C. Periodically terminating the SiC:N surface with a graphitic C boundary layer and controlling the SiC:N/C thickness ratio yield nanocrystalline SiC grains ranging in size from 365 to 23 nm. Frequency domain thermo-reflectance is employed to determine the thermal conductivity, which is found to vary from 35.5 W m-1 K-1 for monolithic undoped α-SiC films to 1.6 W m-1 K-1 for a SiC:N/C superlattice with a 47 nm period and a SiC:N/C thickness ratio of 11. A series conductance model is employed tomore » explain the dependence of the thermal conductivity on the superlatticestructure. Our results indicate that the thermal conductivity is more dependent on the SiC:N/C thickness ratio than the SiC:N grain size, indicative of strong boundary layerphonon scattering.« less

  15. Thermal conductivity in nanocrystalline-SiC/C superlattices

    SciTech Connect (OSTI)

    Habermehl, S.; Serrano, J. R.

    2015-11-17

    We reported the formation of thin film superlattices consisting of alternating layers of nitrogen-doped SiC (SiC:N) and C. Periodically terminating the SiC:N surface with a graphitic C boundary layer and controlling the SiC:N/C thickness ratio yield nanocrystalline SiC grains ranging in size from 365 to 23 nm. Frequency domain thermo-reflectance is employed to determine the thermal conductivity, which is found to vary from 35.5 W m-1 K-1 for monolithic undoped α-SiC films to 1.6 W m-1 K-1 for a SiC:N/C superlattice with a 47 nm period and a SiC:N/C thickness ratio of 11. A series conductance model is employed to explain the dependence of the thermal conductivity on the superlatticestructure. Our results indicate that the thermal conductivity is more dependent on the SiC:N/C thickness ratio than the SiC:N grain size, indicative of strong boundary layerphonon scattering.

  16. The cost of transportation`s oil dependence

    SciTech Connect (OSTI)

    Greene, D.L.

    1995-05-01

    Transportation is critical to the world`s oil dependence problem because of the large share of world oil it consumes and because of its intense dependence on oil. This paper will focus on the economic costs of transportation`s oil dependence.

  17. FAA Smoke Transport Code

    Energy Science and Technology Software Center (OSTI)

    2006-10-27

    FAA Smoke Transport Code, a physics-based Computational Fluid Dynamics tool, which couples heat, mass, and momentum transfer, has been developed to provide information on smoke transport in cargo compartments with various geometries and flight conditions. The software package contains a graphical user interface for specification of geometry and boundary conditions, analysis module for solving the governing equations, and a post-processing tool. The current code was produced by making substantial improvements and additions to a codemore » obtained from a university. The original code was able to compute steady, uniform, isothermal turbulent pressurization. In addition, a preprocessor and postprocessor were added to arrive at the current software package.« less

  18. Fuel cell water transport

    DOE Patents [OSTI]

    Vanderborgh, Nicholas E.; Hedstrom, James C.

    1990-01-01

    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.

  19. Saturated Zone Colloid Transport

    SciTech Connect (OSTI)

    H. Viswanathan; P. Reimus

    2003-09-05

    Colloid retardation is influenced by the attachment and detachment of colloids from immobile surfaces. This analysis demonstrates the development of parameters necessary to estimate attachment and detachment of colloids and, hence, retardation in both fractured tuff and porous alluvium. Field and experimental data specific to fractured tuff are used for the analysis of colloid retardation in fractured tuff. Experimental data specific to colloid transport in alluvial material from Yucca Mountain as well as bacteriophage field studies in alluvial material, which are thought to be good analogs for colloid transport, are used to estimate attachment and detachment of colloids in the alluvial material. There are no alternative scientific approaches or technical methods for calculating these retardation factors.

  20. Transportation and the marketplace

    SciTech Connect (OSTI)

    Soeoet, S.

    1996-12-31

    In the Chicago six-county metropolitan area, the number of registered vehicles grew by over 800,000 vehicles in the 1980s; by contrast the population increased by just over 150,000 during the same time. This ratio of growth in automobiles versus population (five to one) has contributed to overall increases in travel, congestion and energy use. The objective of this report is to examine how and why this has occurred and what we might expect in the near future to address the growing traffic problems and energy use. Specifically, the focus is on energy use by household vehicles and other forms of passenger travel. Data on population trends, gasoline prices, commuting and transit use, and transportation energy use are presented and interpreted. Intelligent transportation systems and decreased single vehicle emissions are briefly described as methods to decrease congestion and pollution. 9 figs., 2 tabs.

  1. Synthesis, electronic and optical properties of Si nanostructures

    SciTech Connect (OSTI)

    Dinh, L.N.

    1996-09-01

    Silicon and silicon oxide nanostructures have been deposited on solid substrates, in an ultra high vacuum (UHV) chamber, by laser ablation or thermal vaporization. Laser ablation followed by substrate post annealing produced Si clusters with average size of a few nanometers, on highly oriented pyrolytic graphite (HOPG) surfaces. This technique, which is based on surface diffusion, is limited to the production of less than one layer of clusters on a given surface. The low coverage of Si clusters and the possibility of nonradiative decay of excitation in the Si cores to the HOPG substrates in these samples rendered them unsuitable for many optical measurements. Thermal vaporization of Si in an Ar buffer gas, on the contrary, yielded multilayer coverage of Si nanoclusters with a fairly narrow size distribution of about 2 nm, full width at half maximum (FWHM). As a result, further study was performed only on Si nanoclusters synthesized by thermal vaporization in a buffer gas. High resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) revealed that these nanoclusters were crystalline. However, during synthesis, if oxygen was the buffer gas, a network of amorphous Si oxide nanostructures (an-SiO{sub x}) with occasional embedded Si dots was formed. All samples showed strong infrared and/or visible photoluminescence (PL) with varying decay times from nanoseconds to microseconds depending on synthesis conditions. There were differences in PL spectra for hydrogen and oxygen passivated nc-Si, while many common PL properties between oxygen passivated nc-Si and an SiO{sub x} were observed. The observed experimental results can be best explained by a model involving absorption between quantum confined states in the Si cores and emission for which the decay times are very sensitive to surface and/or interface states.

  2. Heat transport system

    DOE Patents [OSTI]

    Pierce, Bill L.

    1978-01-01

    A heat transport system of small size which can be operated in any orientation consists of a coolant loop containing a vaporizable liquid as working fluid and includes in series a vaporizer, a condenser and two one-way valves and a pressurizer connected to the loop between the two valves. The pressurizer may be divided into two chambers by a flexible diaphragm, an inert gas in one chamber acting as a pneumatic spring for the system.

  3. Transportation of medical isotopes

    SciTech Connect (OSTI)

    Nielsen, D.L.

    1997-11-19

    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.

  4. Ozone transport commission developments

    SciTech Connect (OSTI)

    Joyce, K.M.

    1995-08-01

    On September 27, 1994, the states of the Ozone Transport Commission (OTC) signed an important memorandum of understanding (MOU) agreeing to develop a regional strategy for controlling stationary sources of nitrogen oxide emissions. Specifically, the states of the Ozone Transport Region, OTR, agreed to propose regulations for the control of NOx emissions from boilers and other indirect heat exchangers with a maximum gross heat input rate of at least 250 million BTU per hour. The Ozone Transport Region was divided into Inner, Outer and Northern Zones. States in the Outer Zone agreed to reduce NOx emissions by 55%. States in the Inner Zone agreed to reduce NOx emissions 65%. Facilities in both zones have the option to emit NOx at a rate no greater than 0.2 pounds per million Btu by May 1, 1999. This option provides fairness for the gas-fired plants which already have relatively low NOx emissions. Additionally, States in the Inner and Outer Zones agreed to reduce their NOx emissions by 75% or to emit NOx at a rate no greater than 0.15 pounds per million BTU by May 1, 2003. The Northern Zone States agree to reduce their rate of NOx emissions by 55% from base year levels by May 1, 2003, or to emit NOx at a rate no greater than 0.2 pounds per million BTU. As part of this MOU, States also agreed to develop a regionwide trading mechanism to provide a cost-effective mechanism for implementing the reductions.

  5. Engineering Heteromaterials to Control Lithium Ion Transport Pathways

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

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; Dayeh, Shadi A.

    2015-12-21

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. Here, we utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through themore » systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Lastly, our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries.« less

  6. Engineering Heteromaterials to Control Lithium Ion Transport Pathways

    SciTech Connect (OSTI)

    Liu, Yang; Vishniakou, Siarhei; Yoo, Jinkyoung; Dayeh, Shadi A.

    2015-12-21

    Safe and efficient operation of lithium ion batteries requires precisely directed flow of lithium ions and electrons to control the first directional volume changes in anode and cathode materials. Understanding and controlling the lithium ion transport in battery electrodes becomes crucial to the design of high performance and durable batteries. Recent work revealed that the chemical potential barriers encountered at the surfaces of heteromaterials play an important role in directing lithium ion transport at nanoscale. Here, we utilize in situ transmission electron microscopy to demonstrate that we can switch lithiation pathways from radial to axial to grain-by-grain lithiation through the systematic creation of heteromaterial combinations in the Si-Ge nanowire system. Lastly, our systematic studies show that engineered materials at nanoscale can overcome the intrinsic orientation-dependent lithiation, and open new pathways to aid in the development of compact, safe, and efficient batteries.

  7. 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.; Ouerghi, A.; Zielinski, M.; Chassagne, T.

    2010-10-25

    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.

  8. 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)

    2014-06-30

    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.

  9. transportation | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    transportation | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear...

  10. the-transportation-research-board

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

    January 22-26, 2012 The Transportation Research Board (TRB) 91st Annual Meeting will be held in Washington, D.C. at the Washington Marriott Wardman Park, Omni Shoreham, and Washington Hilton hotels. The information-packed program will attract more than 11,000 transportation professionals from around the world to Washington, D.C., January 22-26, 2012. The Transportation Research and Analysis Computing Center (TRACC) team will showcase current projects at the upcoming Transportation Research Board

  11. Electrical and photovoltaic characteristics of MoS{sub 2}/Si p-n junctions

    SciTech Connect (OSTI)

    Hao, Lanzhong Liu, Yunjie Gao, Wei; Han, Zhide; Xue, Qingzhong; Zeng, Huizhong; Wu, Zhipeng; Zhu, Jun; Zhang, Wanli

    2015-03-21

    Bulk-like molybdenum disulfide (MoS{sub 2}) thin films were deposited on the surface of p-type Si substrates using dc magnetron sputtering technique and MoS{sub 2}/Si p-n junctions were formed. The vibrating modes of E{sup 1}{sub 2g} and A{sub 1g} were observed from the Raman spectrum of the MoS{sub 2} films. The current density versus voltage (J-V) characteristics of the junction were investigated. A typical J-V rectifying effect with a turn-on voltage of 0.2 V was shown. In different voltage range, the electrical transporting of the junction was dominated by diffusion current and recombination current, respectively. Under the light illumination of 15 mW cm{sup −2}, the p-n junction exhibited obvious photovoltaic characteristics with a short-circuit current density of 3.2 mA cm{sup −2} and open-circuit voltage of 0.14 V. The fill factor and energy conversion efficiency were 42.4% and 1.3%, respectively. According to the determination of the Fermi-energy level (∼4.65 eV) and energy-band gap (∼1.45 eV) of the MoS{sub 2} films by capacitance-voltage curve and ultraviolet-visible transmission spectra, the mechanisms of the electrical and photovoltaic characteristics were discussed in terms of the energy-band structure of the MoS{sub 2}/Si p-n junctions. The results hold the promise for the integration of MoS{sub 2} thin films with commercially available Si-based electronics in high-efficient photovoltaic devices.

  12. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect (OSTI)

    Stefan Miska; Troy Reed; Ergun Kuru

    2004-09-30

    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

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

    SciTech Connect (OSTI)

    Turchi, P.E.A.; Ivashchenko, V.I.

    2014-11-01

    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.

  14. 2016 Sustainable Transportation Summit Agenda

    Broader source: Energy.gov [DOE]

    Hosted by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE), this is the agenda for the first ever Sustainable Transportation Summit which brings together transportation and mobility leaders to discuss the technology, policy, and market innovations that hold the potential to shape the transportation system of the future.

  15. Ultra-high current density thin-film Si diode

    DOE Patents [OSTI]

    Wang; Qi

    2008-04-22

    A combination of a thin-film .mu.c-Si and a-Si:H containing diode structure characterized by an ultra-high current density that exceeds 1000 A/cm.sup.2, comprising: a substrate; a bottom metal layer disposed on the substrate; an n-layer of .mu.c-Si deposited the bottom metal layer; an i-layer of .mu.c-Si deposited on the n-layer; a buffer layer of a-Si:H deposited on the i-layer, a p-layer of .mu.c-Si deposited on the buffer layer; and a top metal layer deposited on the p-layer.

  16. Epitaxial CoSi2 on MOS devices

    DOE Patents [OSTI]

    Lim, Chong Wee; Shin, Chan Soo; Petrov, Ivan Georgiev; Greene, Joseph E.

    2005-01-25

    An Si.sub.x N.sub.y or SiO.sub.x N.sub.y liner is formed on a MOS device. Cobalt is then deposited and reacts to form an epitaxial CoSi.sub.2 layer underneath the liner. The CoSi.sub.2 layer may be formed through a solid phase epitaxy or reactive deposition epitaxy salicide process. In addition to high quality epitaxial CoSi.sub.2 layers, the liner formed during the invention can protect device portions during etching processes used to form device contacts. The liner can act as an etch stop layer to prevent excessive removal of the shallow trench isolation, and protect against excessive loss of the CoSi.sub.2 layer.

  17. Analysis and recommendations for DPA calculations in SiC

    SciTech Connect (OSTI)

    Heinisch, H.L.

    1998-09-01

    Recent modeling results, coupled with the implications of available experimental results, provide sufficient information to achieve consensus on the values of threshold displacement energies to use in displacements per atom (DPA) calculations. The values recommended here, 20 eV for C and 35 eV for Si, will be presented for adoption by the international fusion materials community at the next IEA SiC/SiC workshop.

  18. Steel-SiC Metal Matrix Composite Development

    SciTech Connect (OSTI)

    Smith, Don D.

    2005-07-17

    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.

  19. Electronics for the Si detectors in APEX

    SciTech Connect (OSTI)

    Wilt, P.R. |; Betts, R.R.; Freer, M.

    1994-07-01

    APEX (ATLAS Positron EXperiment), a collaborative effort of ANL, FSU, MSU/NSCL, Princeton, Queen`s, Rochester, Washington and Yale, is an experiment to study positron and electron production in very heavy ion collisions. The electrons and positrons are detected with two detector arrays, each consisting of 216 1 mm thick Si PIN diodes, and their energy and time-of-flight are measured. The number of detectors and limited space made it necessary to develop a system that could efficiently process and transfer signals from the detectors to the charge sensing ADC`s and data readout electronics as well as monitor the condition of the detectors. The discussion will cover the electronics designed for the Si detectors, including the charge amplifier, ``Mother board`` for the charge amplifiers, 8 channel Shaper, 16 channel Constant Fraction Discriminator (CFD), 16 channel Peak-to-FERA (PTF) and the integration of the CFD and PTF with Charge sensing ADC`s. Function and performance of the individual modules as well as the system as a whole will be discussed.

  20. 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

    2013-09-30

    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

  1. Financing Sustainable Urban Transport | Open Energy Information

    Open Energy Info (EERE)

    Transport Toolkit Region(s): Global Related Tools Production Costs of Alternative Transportation Fuels Transport Regulation from Theory to Practice: General...

  2. National Transportation Stakeholders Forum (NTSF) | Department...

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

    National Transportation Stakeholders Forum (NTSF) National Transportation Stakeholders Forum (NTSF) National Transportation Stakeholders Forum (NTSF) The U.S. Department of Energy ...

  3. Texas Department of Transportation | Open Energy Information

    Open Energy Info (EERE)

    Texas Department of Transportation Jump to: navigation, search Logo: Texas Department of Transportation Name: Texas Department of Transportation Abbreviation: TxDOT Place: Austin,...

  4. The World Bank - Transport | Open Energy Information

    Open Energy Info (EERE)

    provides relevant information about transport, focusing on The World Bank Transport Strategy - Safe, Clean and Affordable - Transport for Development. The website includes...

  5. VTPI-Transportation Statistics | Open Energy Information

    Open Energy Info (EERE)

    Area: Transportation Resource Type: Dataset Website: www.vtpi.orgtdmtdm80.htm Cost: Free VTPI-Transportation Statistics Screenshot References: VTPI-Transportation Statistics1...

  6. Ecolane Transport Conultancy | Open Energy Information

    Open Energy Info (EERE)

    Ecolane Transport Conultancy Jump to: navigation, search Name: Ecolane Transport Conultancy Place: Bristol, United Kingdom Zip: BS3 4UB Product: UK-based sustainable transport...

  7. Waste Isolation Pilot Plant Transportation Security | Department...

    Office of Environmental Management (EM)

    Transportation Security Waste Isolation Pilot Plant Transportation Security Waste Isolation Pilot Plant Transportation Security (2.41 MB) More Documents & Publications Enterprise ...

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

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

    More Documents & Publications Novel Lithium Ion Anode Structures: Overview of New DOE BATT Anode Projects Synthesis and Characterization of Structured Si-Carbon Nanocomposite ...

  9. Electrostatic Transfor of Patterned Epitaxial Graphene from SiC...

    Office of Scientific and Technical Information (OSTI)

    Electrostatic Transfor of Patterned Epitaxial Graphene from SiC (001) to Glass. Citation Details In-Document Search Title: Electrostatic Transfor of Patterned Epitaxial Graphene ...

  10. Centrotherm SiTec GmbH | Open Energy Information

    Open Energy Info (EERE)

    Germany Product: Germany-based subsidiary of Centrotherm. The unit provides turnkey manufacturing equipment for polysilicon factory. References: Centrotherm SiTec GmbH1 This...

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

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

    Anodes and Functional Polymer Binders Synthesis and Characterization of Structured Si-Carbon Nanocomposite Anodes and Functional Polymer Binders 2013 DOE Hydrogen and ...

  12. Method for the hydrogenation of poly-si

    DOE Patents [OSTI]

    Wang, Qi

    2013-11-12

    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.

  13. Buckeye Silicon BeSi | Open Energy Information

    Open Energy Info (EERE)

    Name: Buckeye Silicon (BeSi) Place: Toledo, Ohio Product: Ohio-based polysilicon startup focusing on modular production. Coordinates: 46.440613, -122.847838 Show Map...

  14. Boron doped Si rich oxide/SiO{sub 2} and silicon rich nitride/SiN{sub x} bilayers on molybdenum-fused silica substrates for vertically structured Si quantum dot solar cells

    SciTech Connect (OSTI)

    Lin, Ziyun Wu, Lingfeng; Jia, Xuguang; Zhang, Tian; Puthen-Veettil, Binesh; Yang, Terry Chien-Jen; Conibeer, Gavin; Perez-Wurfl, Ivan

    2015-07-28

    Vertically structured Si quantum dots (QDs) solar cells with molybdenum (Mo) interlayer on quartz substrates would overcome current crowding effects found in mesa-structured cells. This study investigates the compatibility between boron (B) doped Si QDs bilayers and Mo-fused silica substrate. Both Si/SiO{sub 2} and Si/SiN{sub x} based QDs bilayers were studied. The material compatibility under high temperature treatment was assessed by examining Si crystallinity, microstress, thin film adhesion, and Mo oxidation. It was observed that the presence of Mo interlayer enhanced the Si QDs size confinement, crystalline fraction, and QDs size uniformity. The use of B doping was preferred compared to phosphine (PH{sub 3}) doping studied previously in terms of better surface and interface properties by reducing oxidized spots on the film. Though crack formation due to thermal mismatch after annealing remained, methods to overcome this problem were proposed in this paper. Schematic diagram to fabricate full vertical structured Si QDs solar cells was also suggested.

  15. Hydrogen Evolution at Si-based Metal-Insulator-Semiconductor...

    Office of Scientific and Technical Information (OSTI)

    Hydrogen Evolution at Si-based Metal-Insulator-Semiconductor Photoelectrodes Enhanced by Inversion Channel Charge Collection and Hydrogen Spillover Citation Details In-Document...

  16. Special Inquiry: SI-11-27 | Department of Energy

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

    November 27, 2006 Selected Controls over Classified Information at the Los Alamos National Laboratory Special Inquiry: SI-11-27 (1.96 MB) More Documents & Publications Special ...

  17. ADVANCED CUTTINGS TRANSPORT STUDY

    SciTech Connect (OSTI)

    Stefan Miska; Nicholas Takach; Kaveh Ashenayi; Mengjiao Yu; Ramadan Ahmed; Mark Pickell; Len Volk; Lei Zhou; Zhu Chen; Aimee Washington; Crystal Redden

    2003-09-30

    The Quarter began with installing the new drill pipe, hooking up the new hydraulic power unit, completing the pipe rotation system (Task 4 has been completed), and making the SWACO choke operational. Detailed design and procurement work is proceeding on a system to elevate the drill-string section. The prototype Foam Generator Cell has been completed by Temco and delivered. Work is currently underway to calibrate the system. Literature review and preliminary model development for cuttings transportation with polymer foam under EPET conditions are in progress. Preparations for preliminary cuttings transport experiments with polymer foam have been completed. Two nuclear densitometers were re-calibrated. Drill pipe rotation system was tested up to 250 RPM. Water flow tests were conducted while rotating the drill pipe up to 100 RPM. The accuracy of weight measurements for cuttings in the annulus was evaluated. Additional modifications of the cuttings collection system are being considered in order to obtain the desired accurate measurement of cuttings weight in the annular test section. Cutting transport experiments with aerated fluids are being conducted at EPET, and analyses of the collected data are in progress. The printed circuit board is functioning with acceptable noise level to measure cuttings concentration at static condition using ultrasonic method. We were able to conduct several tests using a standard low pass filter to eliminate high frequency noise. We tested to verify that we can distinguish between different depths of sand in a static bed of sand. We tested with water, air and a mix of the two mediums. Major modifications to the DTF have almost been completed. A stop-flow cell is being designed for the DTF, the ACTF and Foam Generator/Viscometer which will allow us to capture bubble images without the need for ultra fast shutter speeds or microsecond flash system.

  18. Transport properties of ultrathin black phosphorus on hexagonal boron nitride

    SciTech Connect (OSTI)

    Doganov, Rostislav A.; zyilmaz, Barbaros; Koenig, Steven P.; Yeo, Yuting; Watanabe, Kenji; Taniguchi, Takashi

    2015-02-23

    Ultrathin black phosphorus, or phosphorene, is a two-dimensional material that allows both high carrier mobility and large on/off ratios. Similar to other atomic crystals, like graphene or layered transition metal dichalcogenides, the transport behavior of few-layer black phosphorus is expected to be affected by the underlying substrate. The properties of black phosphorus have so far been studied on the widely utilized SiO{sub 2} substrate. Here, we characterize few-layer black phosphorus field effect transistors on hexagonal boron nitridean atomically smooth and charge trap-free substrate. We measure the temperature dependence of the field effect mobility for both holes and electrons and explain the observed behavior in terms of charged impurity limited transport. We find that in-situ vacuum annealing at 400?K removes the p-doping of few-layer black phosphorus on both boron nitride and SiO{sub 2} substrates and reduces the hysteresis at room temperature.

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

    SciTech Connect (OSTI)

    Henager, Charles H.; Jiang, Weilin

    2014-11-01

    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.

  20. Photoluminescence of as-grown and thermal annealed SiO{sub x}/Si-nanocrystals heterolayers grown by reactive rf sputtering

    SciTech Connect (OSTI)

    Mota-Pineda, E.; Melendez-Lira, M.; Zapata-Torres, M.; Angel, P. del; Perez-Centeno, A.; Santana-Aranda, M. A.; Jimenez-Sandoval, S.

    2010-11-15

    SiO{sub x}/Si-nanocrystals (Si NCs) heterolayers were fabricated employing a rf magnetron sputtering system. The synthesis process, through modification of the oxygen partial pressure of the plasma, promotes the synthesis of stoichiometric SiO{sub 2} layers and affect the Si NCs layer giving place to SiO{sub x}/Si NCs (1.64Si NCs. Thermal annealing at 1100 deg. C promoted the SiO{sub 2} stoichiometry in the interface and the crystallization of more Si NCs. The results allow us to clearly identify the origin of the PL bands; indicating that the near-infrared emission is related to the nonstoichiometric oxide while the red and green bands are originated in Si NCs.

  1. 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.; Tanikawa, K.; Oki, S.; Kawano, M.; Miyao, M.; Hamaya, K.

    2014-08-18

    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.

  2. 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

    2014-04-01

    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.

  3. OXYGEN TRANSPORT CERAMIC MEMBRANES

    SciTech Connect (OSTI)

    Dr. Sukumar Bandopadhyay; Dr. Nagendra Nagabhushana

    2000-10-01

    This is the third quarterly report on oxygen Transport Ceramic Membranes. In the following, the report describes the progress made by our university partners in Tasks 1 through 6, experimental apparatus that was designed and built for various tasks of this project, thermodynamic calculations, where applicable and work planned for the future. (Task 1) Design, fabricate and evaluate ceramic to metal seals based on graded ceramic powder/metal braze joints. (Task 2) Evaluate the effect of defect configuration on ceramic membrane conductivity and long term chemical and structural stability. (Task 3) Determine materials mechanical properties under conditions of high temperatures and reactive atmospheres. (Task 4) Evaluate phase stability and thermal expansion of candidate perovskite membranes and develop techniques to support these materials on porous metal structures. (Task 5) Assess the microstructure of membrane materials to evaluate the effects of vacancy-impurity association, defect clusters, and vacancy-dopant association on the membrane performance and stability. (Task 6) Measure kinetics of oxygen uptake and transport in ceramic membrane materials under commercially relevant conditions using isotope labeling techniques.

  4. 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

    2003-07-30

    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.

  5. 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.

    1992-06-01

    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.

  6. Resolving the mystery of transport within internal transport barriers

    SciTech Connect (OSTI)

    Staebler, G. M.; Belli, E. A.; Candy, J.; Waltz, R. E.; Greenfield, C. M.; Lao, L. L.; Smith, S. P.; Kinsey, J. E.; Grierson, B. A.; Chrystal, C.

    2014-05-15

    The Trapped Gyro-Landau Fluid (TGLF) quasi-linear model [G. M. Staebler, et al., Phys. Plasmas 12, 102508 (2005)], which is calibrated to nonlinear gyrokinetic turbulence simulations, is now able to predict the electron density, electron and ion temperatures, and ion toroidal rotation simultaneously for internal transport barrier (ITB) discharges. This is a strong validation of gyrokinetic theory of ITBs, requiring multiple instabilities responsible for transport in different channels at different scales. The mystery of transport inside the ITB is that momentum and particle transport is far above the predicted neoclassical levels in apparent contradiction with the expectation from the theory of suppression of turbulence by EB velocity shear. The success of TGLF in predicting ITB transport is due to the inclusion of ion gyro-radius scale modes that become dominant at high EB velocity shear and to improvements to TGLF that allow momentum transport from gyrokinetic turbulence to be faithfully modeled.

  7. Quality Assurance Plan for Transportation Management Division Transportation Training Programs

    SciTech Connect (OSTI)

    Not Available

    1994-10-01

    The U.S. Department of Transportation (DOT) implemented new rules requiring minimum levels of training for certain key individuals who handle, package, transport, or otherwise prepare hazardous materials for transportation. In response to these rules, the U.S. Department of Energy (DOE), Transportation Management Division (TMD), has developed a transportation safety training program. This program supplies designed instructional methodology and course materials to provide basic levels of DOT training to personnel for whom training has become mandatory. In addition, this program provides advanced hazardous waste and radioactive material packaging and transportation training to help personnel achieve proficiency and/or certification as hazardous waste and radioactive material shippers. This training program does not include site-specific or task-specific training beyond DOT requirements.

  8. Isotope Program Transportation | Department of Energy

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

    Isotope Program Transportation Isotope Program Transportation Isotope Program Transportation (894.11 KB) More Documents & Publications Nuclear Fuel Storage and Transportation Planning Project Overview Section 180(c) Ad Hoc Working Group DOE Office of Nuclear Energy

  9. NREL: Transportation Research - Subscribe to the Transportation and

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

    Hydrogen Newsletter Subscribe to the Transportation and Hydrogen Newsletter To subscribe to or unsubscribe from the Transportation and Hydrogen Newsletter, complete one of the forms below. Subscribe To subscribe to the newsletter, submit your email address. Email: Submit Unsubscribe To unsubscribe from the newsletter, submit your email address. Email: Submit Printable Version Transportation Research Home Capabilities Projects Success Stories Facilities Working with Us Publications Data &

  10. Transportation Data Programs:Transportation Energy Data Book,Vehicle

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

    Technologies Market Report, and VT Fact of the Week | Department of Energy Transportation Data Programs:Transportation Energy Data Book,Vehicle Technologies Market Report, and VT Fact of the Week Transportation Data Programs:Transportation Energy Data Book,Vehicle Technologies Market Report, and VT Fact of the Week 2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting van009_davis_2013_p.pdf (3.39 MB) More Documents &

  11. DOE TMD transportation training module 14 transportation of explosives

    SciTech Connect (OSTI)

    Griffith, R.L. Jr.

    1994-07-01

    The Department of Energy Transportation Management Division has developed training module 14, entitled {open_quotes}Transportation of Explosives{close_quotes} to compliment the basic {open_quotes}core ten{close_quotes} training modules of the Hazardous Materials Modular Training Program. The purpose of this training module is to increase awareness of the Department of Transportation (DOT) requirements concerning the packaging and transportation of explosives. Topics covered in module 14 include the classification of explosives, approval and registration of explosives, packaging requirements, hazard communication requirements, separation and segregation compatibility requirements, loading and unloading operations, as well as safety measures required in the event of a vehicle accident involving explosives.

  12. Intelligent Transportation Systems Deployment Analysis System...

    Open Energy Info (EERE)

    Transportation Systems Deployment Analysis System AgencyCompany Organization: Cambridge Systematics Sector: Energy Focus Area: Transportation Resource Type: Software...

  13. Westminster Energy Environment Transport Forum | Open Energy...

    Open Energy Info (EERE)

    Westminster Energy Environment Transport Forum Jump to: navigation, search Name: Westminster Energy, Environment & Transport Forum Place: United Kingdom Product: String...

  14. Africa's Transport Infrastructure Mainstreaming Maintenance and...

    Open Energy Info (EERE)

    Transport Infrastructure Mainstreaming Maintenance and Management Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Africa's Transport Infrastructure Mainstreaming...

  15. Advancing Transportation Through Vehicle Electrification - PHEV...

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

    More Documents & Publications Advancing Transportation Through Vehicle Electrification - ... Office Merit Review 2014: Advancing Transportation through Vehicle Electrification - Ram ...

  16. Transportation, Aging and Disposal Canister System Performance...

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

    Transportation, Aging and Disposal Canister System Performance Specification: Revision 1 Transportation, Aging and Disposal Canister System Performance Specification: Revision 1 ...

  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. Testimonials - Partnerships in Sustainable Transportation - The...

    Office of Environmental Management (EM)

    Testimonials - Partnerships in Sustainable Transportation - The Ohio State University Testimonials - Partnerships in Sustainable Transportation - The Ohio State University Addthis ...

  19. Department of Transportation Pipeline and Hazardous Materials...

    Office of Environmental Management (EM)

    Transportation Pipeline and Hazardous Materials Safety Administration Activities Department of Transportation Pipeline and Hazardous Materials Safety Administration Activities...

  20. EM Waste and Materials Disposition & Transportation | Department...

    Office of Environmental Management (EM)

    Waste and Materials Disposition & Transportation EM Waste and Materials Disposition & Transportation DOE's Radioactive Waste Management Priorities: Continue to manage waste ...

  1. 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

    2014-10-28

    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 m 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 350C. The measured photocurrent dependence on input power shows a linear correspondence over more than three decades, and the frequency response of a 250 m-length p-i-n device is measured to be ~1.7 GHz formorea wavelength of ? = 2.2 m, thus potentially opening up new communication bands for photonic integrated circuits.less

  2. Electronic structures of GeSi nanoislands grown on pit-patterned Si(001) substrate

    SciTech Connect (OSTI)

    Ye, Han Yu, Zhongyuan

    2014-11-15

    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 Schrdinger 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.

  3. Formation and incorporation of SiF{sub 4} molecules in F-implanted preamorphized Si

    SciTech Connect (OSTI)

    De Salvador, D.; Bisognin, G.; Napolitani, E.; Mastromatteo, M.; Baggio, N.; Carnera, A.; Boscherini, F.; Cristiano, F.

    2009-09-07

    The local structure of fluorine incorporated in crystalline silicon following solid phase epitaxial regrowth was investigated by means of x-ray absorption spectroscopy at the F K-edge. We clearly demonstrate that most F is found in SiF{sub 4} molecules in the crystalline matrix. A kinetic pathway, which explains our observation and which is also able to rationalize previous results in a common and coherent framework, is proposed.

  4. Transportation (technology 86)

    SciTech Connect (OSTI)

    Caplan, G.

    1986-01-01

    As railroads strive to cut operating and maintenance costs in an increasingly competitive transportation industry, AC propulsion and microprocessors figure prominently in their plans. New generations of locomotives and cars incorporating AC propulsion and microprocessors entered service last year, and the trend is destined to continue. Electronics is also making possible freight trains that rely on a telemetry unit at the rear to monitor airbrake pressure, instead of a manned caboose. AC is gaining acceptance because it permits simpler motors with fewer parts to wear and replace, and it saves energy by allowing the traction motors to work as generators during braking. Microprocessors are being used in locomotives not only to reduce energy waste through better regulation of traction motor currents and auxiliary devices such as cooling fans, but also to control engine speed, braking, and other functions.

  5. Hydrogen transport membranes

    DOE Patents [OSTI]

    Mundschau, Michael V.

    2005-05-31

    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.

  6. Heat transport system

    DOE Patents [OSTI]

    Harkness, Samuel D.

    1982-01-01

    A falling bed of ceramic particles receives neutron irradiation from a neutron-producing plasma and thereby transports energy as heat from the plasma to a heat exchange location where the ceramic particles are cooled by a gas flow. The cooled ceramic particles are elevated to a location from which they may again pass by gravity through the region where they are exposed to neutron radiation. Ceramic particles of alumina, magnesia, silica and combinations of these materials are contemplated as high-temperature materials that will accept energy from neutron irradiation. Separate containers of material incorporating lithium are exposed to the neutron flux for the breeding of tritium that may subsequently be used in neutron-producing reactions. The falling bed of ceramic particles includes velocity partitioning between compartments near to the neutron-producing plasma and compartments away from the plasma to moderate the maximum temperature in the bed.

  7. Nanoengineered membranes for controlled transport

    DOE Patents [OSTI]

    Doktycz, Mitchel J. [Oak Ridge, TN; Simpson, Michael L. [Knoxville, TN; McKnight, Timothy E. [Greenback, TN; Melechko, Anatoli V. [Oak Ridge, TN; Lowndes, Douglas H. [Knoxville, TN; Guillorn, Michael A. [Knoxville, TN; Merkulov, Vladimir I. [Oak Ridge, TN

    2010-01-05

    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.

  8. Carrier mediated reduction of stiffness in nanoindented crystalline Si(100)

    SciTech Connect (OSTI)

    Kataria, S. Dhara, Sandip Dash, S.; Tyagi, A. K.

    2015-07-21

    We report the observation of carrier mediated decrease in the stiffness of crystalline (c)-Si(100) under nanoindentation. The apparent elastic moduli of heavily doped (∼1 × 10{sup 21} cm{sup −3}) p- and n-type c-Si are observed to be lower by 5.3%–7.5% than the estimated value for intrinsic (∼1 × 10{sup 14} cm{sup −3}) c-Si. The deviation observed with respect to elastic modulus remarkably matches with the estimated value while considering the electronic elastic strain effect on carrier concentration as an influence of negative pressure coefficient of band gap for Si (Γ-X). The value is predominantly higher than the reported value of a decrease of 1%–3% in stiffness as an effect of impurity in c-Si.

  9. 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.

    1995-12-01

    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.

  10. Mechanistic Selection and Growth of Twinned Bicrystalline Primary Si in Near Eutectic Al-Si Alloys

    SciTech Connect (OSTI)

    Choonho Jung

    2006-12-12

    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.

  11. computational-hydraulics-for-transportation

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

    Transportation Workshop Sept. 23-24, 2009 Argonne TRACC Dr. Steven Lottes This email address is being protected from spambots. You need JavaScript enabled to view it. Announcement pdficon small The Transportation Research and Analysis Computing Center at Argonne National Laboratory will hold a workshop on the use of computational hydraulics for transportation applications. The goals of the workshop are: Bring together people who are using or would benefit from the use of high performance cluster

  12. transportation-system-modeling-webinar

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

    Webinar Announcement Webinar for the Intelligent Transportation Society of the Midwest (ITS Midwest) May 16, 2011 1:00 PM(CST) Hubert Ley Director, TRACC Argonne National Laboratory Argonne, Illinois High Performance Computing in Transportation Research - High Fidelity Transportation Models and More The Role of High-Performance Computing Because ITS relies on a very diverse collection of technologies, including communication and control technologies, advanced computing, information management

  13. Minority Transportation Expenditure Allocation Model

    Energy Science and Technology Software Center (OSTI)

    1993-04-12

    MITRAM (Minority TRansportation expenditure Allocation Model) can project various transportation related attributes of minority (Black and Hispanic) and majority (white) populations. The model projects vehicle ownership, vehicle miles of travel, workers, new car and on-road fleet fuel economy, amount and share of household income spent on gasoline, and household expenditures on public transportation and taxis. MITRAM predicts reactions to sustained fuel price changes for up to 10 years after the change.

  14. Sustainable Transportation | Department of Energy

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

    Sustainable Transportation Sustainable Transportation Bioenergy Bioenergy Read more Hydrogen and Fuel Cells Hydrogen and Fuel Cells Read more Vehicles Vehicles Read more The Office of Energy Efficiency and Renewable Energy (EERE) leads U.S. researchers and other partners in making transportation cleaner and more efficient through solutions that put electric drive vehicles on the road and replace oil with clean domestic fuels. Through our Vehicle, Bioenergy, and Fuel Cell Technologies Offices,

  15. Transportation energy use in Mexico

    SciTech Connect (OSTI)

    Sheinbaum, C.; Meyers, S.; Sathaye, J.

    1994-07-01

    This report presents data on passenger travel and freight transport and analysis of the consequent energy use in Mexico during the 1970--1971 period. We describe changes in modal shares for passenger travel and freight transport, and analyze trends in the energy intensity of different modes. We look in more detail at transportation patterns, energy use, and the related environmental problems in the Mexico City Metropolitan Area, and also discuss policies that have been implemented there to reduce emissions from vehicles.

  16. hydrogen-fueled transportation systems

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

    ... materials to store hydrogen onboard vehicles, leading to more reliable, economic hydrogen-fuel-cell vehicles. "Hydrogen, as a transportation fuel, has great potential to ...

  17. Transportation Security | Department of Energy

    Office of Environmental Management (EM)

    Transportation Security More Documents & Publications Overview for Newcomers West Valley Demonstration Project Low-Level Waste Shipment Indiana Department of Homeland...

  18. Office of Secure Transportation Activities

    Office of Environmental Management (EM)

    Briefing Our Mission To provide safe and secure ground and air transportation of nuclear weapons, nuclear weapons components, and special nuclear materials and conduct other ...

  19. Natural gas marketing and transportation

    SciTech Connect (OSTI)

    Not Available

    1991-01-01

    This book covers: Overview of the natural gas industry; Federal regulation of marketing and transportation; State regulation of transportation; Fundamentals of gas marketing contracts; Gas marketing options and strategies; End user agreements; Transportation on interstate pipelines; Administration of natural gas contracts; Structuring transactions with the nonconventional source fuels credit; Take-or-pay wars- a cautionary analysis for the future; Antitrust pitfalls in the natural gas industry; Producer imbalances; Natural gas futures for the complete novice; State non-utility regulation of production, transportation and marketing; Natural gas processing agreements and Disproportionate sales, gas balancing, and accounting to royalty owners.

  20. Transportation Emergency Preparedness Program (TEPP)

    Broader source: Energy.gov [DOE]

    In an effort to address responder concerns, the Department retooled its approach to emergency responder preparedness and implemented the more simplified and responder-friendly Transportation...

  1. Sustainable Transportation: Accelerating Widespread Adoption...

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

    and reduce GHG emissions, a truly sustainable solution will require more than just ... NREL's sustainable transportation research, development, and deployment (RD&D) efforts are ...

  2. Transportation Statistics Annual Report 1997

    SciTech Connect (OSTI)

    Fenn, M.

    1997-01-01

    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

  3. Streamlining Transportation Corridor Planning Processess: Freight and Traffic Information

    SciTech Connect (OSTI)

    Franzese, Oscar

    2010-08-01

    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

  4. In situ study of the endotaxial growth of hexagonal CoSi{sub 2} nanoplatelets in Si(001)

    SciTech Connect (OSTI)

    Silva Costa, Daniel da; Kellermann, Guinther; Huck-Iriart, Cristián; Giovanetti, Lisandro J.; Requejo, Félix G.

    2015-11-30

    This investigation aims at studying–by in situ grazing-incidence small-angle x-ray scattering–the process of growth of hexagonal CoSi{sub 2} nanoplatelets endotaxially buried in a Si(001) wafer. The early formation of spherical Co nanoparticles with bimodal size distribution in the deposited silica thin film during a pretreatment at 500 °C and their subsequent growth at 700 °C were also characterized. Isothermal annealing at 700 °C promotes a drastic reduction in the number of the smallest Co nanoparticles and a continuous decrease in their volume fraction in the silica thin film. At the same time, Co atoms diffuse across the SiO{sub 2}/Si(001) interface into the silicon wafer, react with Si, and build up thin hexagonal CoSi{sub 2} nanoplatelets, all of them with their main surfaces parallel to Si(111) crystallographic planes. The observed progressive growths in thickness and lateral size of the hexagonal CoSi{sub 2} nanoplatelets occur at the expense of the dissolution of the small Co nanoparticles that are formed during the pretreatment at 500 °C and become unstable at the annealing temperature (700 °C). The kinetics of growth of the volume fraction of hexagonal platelets is well described by the classical Avrami equation.

  5. Water absorption in thermally grown oxides on SiC and Si: Bulk oxide and interface properties

    SciTech Connect (OSTI)

    Liu, Gang; Xu, Can; Feldman, Leonard C.; Yakshinskiy, Boris; Wielunski, Leszek; Gustafsson, Torgny; Bloch, Joseph; Dhar, Sarit

    2014-11-10

    We combine nuclear reaction analysis and electrical measurements to study the effect of water exposure (D{sub 2}O) on the n-type 4H-SiC carbon face (0001{sup }) MOS system and to compare to standard silicon based structures. We find that: (1) The bulk of the oxides on Si and SiC behave essentially the same with respect to deuterium accumulation; (2) there is a significant difference in accumulation of deuterium at the semiconductor/dielectric interface, the SiC C-face structure absorbs an order of magnitude more D than pure Si; (3) standard interface passivation schemes such as NO annealing greatly reduce the interfacial D accumulation; and (4) the effective interfacial charge after D{sub 2}O exposure is proportional to the total D amount at the interface.

  6. Transportation System Concept of Operations

    SciTech Connect (OSTI)

    N. Slater-Thompson

    2006-08-16

    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

  7. Reaction-bonding preparation of Si{sub 3}N{sub 4}/MoSi{sub 2} and Si{sub 3}N{sub 4}/WSi{sub 2} composites from elemental powders

    SciTech Connect (OSTI)

    Zhang, B.R.; Marino, F.

    1997-01-01

    Si{sub 3}N{sub 4}/MoSi{sub 2} and Si{sub 3}N{sub 4}/WSi{sub 2} composites were prepared by reaction-bonding processes using as starting materials powder mixtures of Si-Mo and Si-W, respectively. A presintering step in an Ar-base atmosphere was used before nitriding for the formation of MoSi{sub 2} and WSi{sub 2}; the nitridation in a N{sub 2}-base atmosphere was followed after presintering with the total stepwise cycle of 1,350 C {times} 20 h + 1,400 C {times} 20 h + 1,450 C {times} 2 h. The final phases obtained in the two different composites were Si{sub 3}N{sub 4} and MoSi{sub 2} or WSi{sub 2}; no free elemental Si and Mo or W were detected by X-ray diffraction.

  8. Reaction of Si(111) Surface with Saturated Hydrocarbon

    SciTech Connect (OSTI)

    Suryana, Risa; Nakahara, Hitoshi; Saito, Yahachi; Ichimiya, Ayahiko

    2011-12-10

    Reaction of Si(111) surface with saturated hydrocarbon such as methane (CH{sub 4}) and ethane (C{sub 2}H{sub 6}) was carried out in a gas source molecular beam epitaxy (GSMBE). After carbonization, structures formed on the surface were observed by in situ reflection high-energy electron diffraction (RHEED). Structures transition formed on the surface were 7x7, {delta}-7x7, 1x1, and SiC structures. In the case of CH{sub 4}, the Si surfaces were carbonized at 800 deg. C for 120 min (7.2x10{sup 4} L) with a W-filament of 2800 deg. C, and SiC layers were obtained. In the case of C{sub 2}H{sub 6}, the mixture of 7x7 and SiC structure was observed. Decomposition of hydrocarbon was characterized in quadrupole mass spectroscopy (QMS) measurements. An atomic force microscopy (AFM) image of the mixture of 7x7 and SiC shows a wandering shape. Whereas, the SiC layer shows a regular step. This result seems to be related to the different in the amount of CH{sub 3} molecules on the surface.

  9. Magnetic order and crystal structure study of YNi{sub 4}Si-type NdNi{sub 4}Si

    SciTech Connect (OSTI)

    Yao, Jinlei; Isnard, O.; Morozkin, A.V.; Ivanova, T.I.; Koshkid'ko, Yu.S.; Bogdanov, A.E.; Nikitin, S.A.; Suski, W.

    2015-02-15

    Magnetic measurements and neutron powder diffraction investigation of the magnetic structure of the orthorhombic YNi{sub 4}Si-type (space group Cmmm) NdNi{sub 4}Si compound are presented. The magnetocaloric effect of NdNi{sub 4}Si is calculated in terms of the isothermal magnetic entropy change and it reaches the maximum value of –3.3 J/kg K for a field change of 50 kOe near T{sub C}=12 K. Below ∼12 K, NdNi{sub 4}Si exhibits a commensurate b-axis collinear ferromagnetic ordering with the Cmm′m magnetic space group in a zero magnetic field. At 1.5 K, the neodymium atoms have the magnetic moment of 2.37(5) μ{sub B}. The orthorhombic crystal structure and its thermal evolution are discussed in comparison with the CaCu{sub 5}-type compound. - Graphical abstract: The NdNi{sub 4}Si supplement the series of the orthorhombic derivative of the CaCu{sub 5}-type, namely the YNi{sub 4}Si-type, RNi{sub 4}Si compounds (R=Y, La, Ce, Sm, Gd–Ho). Below ∼12 K in a zero applied magnetic field, NdNi{sub 4}Si exhibits a commensurate b-axis collinear ferromagnetic ordering with the Cmm′m magnetic space group. Compared to the CaCu{sub 5}-type NdNi{sub 4}Si compound, the YNi{sub 4}Si-type counterpart has the relatively high ferromagnetic ordering temperature (9.2 K vs. 12 K), the small magnetocaloric effect (–7.3 J/kg K vs. –3.3 J/kg K for ∆H=50 kOe), and the large magnetic anisotropy at low temperatures. In contrast with CaCu{sub 5}-type NdNi{sub 4}Si, YNi{sub 4}Si-type NdNi{sub 4}Si shows distinct hysteresis loop at 2 K.We suggest that orthorhombic distortion may be used as a prospective route for optimization of permanent magnetic properties in the family of CaCu{sub 5}-type rare earth materials. - Highlights: • Below ∼12 K the YNi{sub 4}Si-type NdNi{sub 4}Si shows a ferromagnetic ordering. • MCE of NdNi{sub 4}Si reaches value of –3.3 J/kg K in 0–50 kOe near Curie point. • NdNi{sub 4}Si exhibits b-axis ferromagnetic order with the Cmm′m magnetic space

  10. Santa Clara Valley Transportation Authority

    Broader source: Energy.gov [DOE]

    Santa Clara Valley Transportation Authority (VTA) is based in San Jose, California, and provides service in and around Santa Clara county. VTA provides bus and light rail service in Santa Clara County, as well as congestion mitigation, highway improvement projects, and countywide transportation planning. VTA's 423 buses serve an annual ridership of more than 39 million and cover approximately 326 square miles.

  11. Radioactive Material Transportation Practices Manual

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

    2008-06-04

    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. Supersedes DOE M 460.2-1.

  12. State & Local Sustainable Transportation Resources

    Office of Energy Efficiency and Renewable Energy (EERE)

    The DOE Office of Energy Efficiency and Renewable Energy provides tools, resources, and more on vehicles, bioenergy, and fuel cells to help state and local governments reduce transportation agency expenses, improve infrastructure, and decrease the impacts of transportation-associated activities on the environment by using advanced vehicles and alternative fuels.

  13. Development of an SI DI Ethanol Optimized Flex Fuel Engine Using...

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

    an SI DI Ethanol Optimized Flex Fuel Engine Using Advanced Valvetrain Development of an SI DI Ethanol Optimized Flex Fuel Engine Using Advanced Valvetrain Presentation given at the ...

  14. Asia Silicon Qinghai Co Ltd aka Asia Si Material | Open Energy...

    Open Energy Info (EERE)

    Silicon Qinghai Co Ltd aka Asia Si Material Jump to: navigation, search Name: Asia Silicon (Qinghai) Co Ltd (aka Asia Si Material) Place: Xining, Qinghai Province, China Zip:...

  15. Career Map: Transportation Worker | Department of Energy

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

    Transportation Worker Career Map: Transportation Worker Transportation workers help to guide a large wind turbine component down a narrow road. Transportation Worker Position Title Transportation Worker Alternate Title(s) Railroad worker, truck driver, driver, long-haul truck driver, water transportation officer or engineer Education & Training Level Bachelor's degree generally not expected Education & Training Level Description Transportation workers' education and training requirements

  16. Transportation Energy Futures Analysis Snapshot

    Broader source: Energy.gov [DOE]

    Transportation currently accounts for 71% of total U.S. petroleum use and 33% of the nation's total carbon emissions. The TEF project explores how combining multiple strategies could reduce GHG emissions and petroleum use by 80%. Researchers examined four key areas – lightduty vehicles, non-light-duty vehicles, fuels, and transportation demand – in the context of the marketplace, consumer behavior, industry capabilities, technology and the energy and transportation infrastructure. The TEF reports support DOE long-term planning. The reports provide analysis to inform decisions about transportation energy research investments, as well as the role of advanced transportation energy technologies and systems in the development of new physical, strategic, and policy alternatives.

  17. Heavy oil transportation by pipeline

    SciTech Connect (OSTI)

    Gerez, J.M.; Pick, A.R.

    1996-12-31

    Worldwide there are a number of pipelines used to transport heavy crude oils. The operations are facilitated in a variety of ways. For example, the Alyeska pipeline is an insulated pipeline transporting warm oil over 800 miles. This 48-inch line experiences limited heat loss due to the insulation, volume of oil contained, and heat gain due to friction and pumping. Some European trunk lines periodically handle heavy and waxy crudes. This is achieved by proper sizing of batches, following waxy crudes with non-waxy crudes, and increased use of scrapers. In a former Soviet republic, the transportation of heavy crude oil by pipeline has been facilitated by blending with a lighter Siberian crude. The paper describes the pipeline transport of heavy crudes by Interprovincial Pipe Line Inc. The paper describes enhancing heavy oil transportation by emulsion formation, droplet suspension, dilution, drag reducing agents, and heating.

  18. Coal Transportation Rate Sensitivity Analysis

    Reports and Publications (EIA)

    2005-01-01

    On December 21, 2004, the Surface Transportation Board (STB) requested that the Energy Information Administration (EIA) analyze the impact of changes in coal transportation rates on projected levels of electric power sector energy use and emissions. Specifically, the STB requested an analysis of changes in national and regional coal consumption and emissions resulting from adjustments in railroad transportation rates for Wyoming's Powder River Basin (PRB) coal using the National Energy Modeling System (NEMS). However, because NEMS operates at a relatively aggregate regional level and does not represent the costs of transporting coal over specific rail lines, this analysis reports on the impacts of interregional changes in transportation rates from those used in the Annual Energy Outlook 2005 (AEO2005) reference case.

  19. More stable hybrid organic solar cells deposited on amorphous Si electron transfer layer

    SciTech Connect (OSTI)

    Samiee, Mehran; Modtland, Brian; Dalal, Vikram L.; Aidarkhanov, Damir

    2014-05-26

    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}.

  20. Oxide 2D electron gases as a route for high carrier densities on (001) Si

    SciTech Connect (OSTI)

    Kornblum, Lior; Jin, Eric N.; Kumah, Divine P.; Walker, Fred J.; Ernst, Alexis T.; Broadbridge, Christine C.; Ahn, Charles H.

    2015-05-18

    Two dimensional electron gases (2DEGs) formed at the interfaces of oxide heterostructures draw considerable interest owing to their unique physics and potential applications. Growing such heterostructures on conventional semiconductors has the potential to integrate their functionality with semiconductor device technology. We demonstrate 2DEGs on a conventional semiconductor by growing GdTiO{sub 3}-SrTiO{sub 3} on silicon. Structural analysis confirms the epitaxial growth of heterostructures with abrupt interfaces and a high degree of crystallinity. Transport measurements show the conduction to be an interface effect, ∼9 × 10{sup 13} cm{sup −2} electrons per interface. Good agreement is demonstrated between the electronic behavior of structures grown on Si and on an oxide substrate, validating the robustness of this approach to bridge between lab-scale samples to a scalable, technologically relevant materials system.

  1. Hail Impact Testing on Crystalline Si Modules with Flexible Packaging |

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

    Department of Energy Hail Impact Testing on Crystalline Si Modules with Flexible Packaging Hail Impact Testing on Crystalline Si Modules with Flexible Packaging Presented at the PV Module Reliability Workshop, February 26 - 27 2013, Golden, Colorado pvmrw13_ps2_westpak_brown.pdf (785.64 KB) More Documents & Publications Test Procedure for UV Weathering Resistance of Backsheet The Acceleration of Degradation by HAST and Air-HAST in c-Si PV Modules Improved Reliability of PV Modules with

  2. 14.11.05 RH Stabilized Si Microwire - JCAP

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

    Stabilized Si Microwire Arrays for Solar-Driven H2O Oxidation Shaner, M. R., Hu, S., Sun, K. & Lewis, N. S. Stabilization of Si microwire arrays for solar-driven H2O oxidation to O2(g) in 1.0 M KOH(aq) using conformal coatings of amorphous TiO2. Energy & Environmental Science 8, 203-207, DOI: 10.1039/c4ee03012e (2015). Scientific Achievement Atomic-layer deposition of TiO2combined with sputtering of NiCrOxoxygen-evolution catalyst on Si microwires yields robust microwire-array

  3. Time-resolved, nonequilibrium carrier dynamics in Si-on-glass thin films for photovoltaic cells

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

    Serafini, John; Akbas, Yunus; Crandall, Lucas; Bellman, Robert; Williams, Carlo Kosik; Sobolewski, Robert

    2016-03-02

    Here, a femtosecond pump–probe spectroscopy method was used to characterize the growth process and transport properties of amorphous silicon-on-glass, thin films, intended as absorbers for photovoltaic cells. We collected normalized transmissivity change (ΔT/T) waveforms and interpreted them using a comprehensive three-rate equation electron trapping and recombination model. Optically excited ~300–500 nm thick Si films exhibited a bi-exponential carrier relaxation with the characteristic times varying from picoseconds to nanoseconds depending on the film growth process. From our comprehensive trapping model, we could determine that for doped and intrinsic films with very low hydrogen dilution the dominant relaxation mode was carrier trapping;more » while for intrinsic films with large hydrogen content and some texture, it was the standard electron–phonon cooling. In both cases, the initial nonequilibrium relaxation was followed by Shockley–Read–Hall recombination. An excellent fit between the model and the ΔT/T experimental transients was obtained and a correlation between the Si film growth process, its hydrogen content, and the associated trap concentration was demonstrated.« less

  4. Endotaxially stabilized B2-FeSi nanodots in Si (100) via ion beam co-sputtering

    SciTech Connect (OSTI)

    Cassidy, Cathal Singh, Vidyadhar; Grammatikopoulos, Panagiotis; Kioseoglou, Joseph; Lal, Chhagan; Sowwan, Mukhles

    2014-04-21

    We report on the formation of embedded B2-FeSi nanodots in [100]-oriented Si substrates, and investigate the crystallographic mechanism underlying the stabilization of this uncommon, bulk-unstable, phase. The nanodots were approximately 10 nm in size, and were formed by iron thin film deposition and subsequent annealing. Cross-sectional transmission electron microscopy, energy loss spectroscopy mapping, and quantitative image simulation and analysis were utilized to identify the phase, strain, and orientational relationship of the nanodots to the host silicon lattice. X-ray photoelectron spectroscopy was utilized to analyze the surface composition and local bonding. Elasticity calculations yielded a nanodot residual strain value of −18%. Geometrical phase analysis graphically pinpointed the positions of misfit dislocations, and clearly showed the presence of pinned (11{sup ¯}1{sup ¯}){sub Si}//(100){sub FeSi}, and unpinned (2{sup ¯}42){sub Si}//(010){sub FeSi}, interfaces. This partial endotaxy in the host silicon lattice was the mechanism that stabilized the B2-FeSi phase.

  5. A low thermal impact annealing process for SiO{sub 2}-embedded Si nanocrystals with optimized interface quality

    SciTech Connect (OSTI)

    Hiller, Daniel Gutsch, Sebastian; Hartel, Andreas M.; Zacharias, Margit; Löper, Philipp; Gebel, Thoralf

    2014-04-07

    Silicon nanocrystals (Si NCs) for 3rd generation photovoltaics or optoelectronic applications can be produced by several industrially compatible physical or chemical vapor deposition technologies. A major obstacle for the integration into a fabrication process is the typical annealing to form and crystallize these Si quantum dots (QDs) which involves temperatures ≥1100  °C for 1 h. This standard annealing procedure allows for interface qualities that correspond to more than 95% dangling bond defect free Si NCs. We study the possibilities to use rapid thermal annealing (RTA) and flash lamp annealing to crystallize the Si QDs within seconds or milliseconds at high temperatures. The Si NC interface of such samples exhibits huge dangling bond defect densities which makes them inapplicable for photovoltaics or optoelectronics. However, if the RTA high temperature annealing is combined with a medium temperature inert gas post-annealing and a H{sub 2} passivation, luminescent Si NC fractions of up to 90% can be achieved with a significantly reduced thermal load. A new figure or merit, the relative dopant diffusion length, is introduced as a measure for the impact of a Si NC annealing procedure on doping profiles of device structures.

  6. Silver (Ag) Transport Mechanisms in TRISO Coated Particles: A Critical Review

    SciTech Connect (OSTI)

    IJ van Rooyen; ML Dunzik-Gougar; PM van Rooyen

    2014-05-01

    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)

    I J van Rooyen; J H Neethling; J A A Engelbrecht; P M van Rooyen; G Strydom

    2012-10-01

    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 DOEs 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. Energy Intensity Indicators: Transportation Energy Consumption

    Broader source: Energy.gov [DOE]

    This section contains an overview of the aggregate transportation sector, combining both passenger and freight segments of this sector. The specific energy intensity indicators for passenger and freight can be obtained from the links, passenger transportation, or freight transportation. For further detail within the transportation sector, download the appropriate Trend Data worksheet containing detailed data and graphics for specific transportation modes.

  9. Safeguards Transporter | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Safeguards Transporter General Davis kicks the tires on a Safeguards Transporter Brigadier General Stephen L. Davis, NNSA's Acting Deputy Administrator for Defense Programs, gets a lesson on how to drive a Safeguards Transporter during a recent visit to the Office of Secure Transportation (OST) headquarters in Albuquerque, New Mexico. OST is responsible for transporting

  10. Moment enhancement in dilute magnetic semiconductors: MnxSi1...

    Office of Scientific and Technical Information (OSTI)

    Moment enhancement in dilute magnetic semiconductors: MnxSi1-x with x 0.1% Citation Details In-Document Search Title: Moment enhancement in dilute magnetic semiconductors: ...

  11. Crystallization from high temperature solutions of Si in copper

    DOE Patents [OSTI]

    Ciszek, Theodore F.

    1994-01-01

    A liquid phase epitaxy method for forming thin crystalline layers of device quality silicon having less than 5X10.sup.16 Cu atoms/cc impurity, comprising: preparing a saturated liquid solution melt of Si in Cu at about 16% to about 90% wt. Si at a temperature range of about 800.degree. C. to about 1400.degree. C. in an inert gas; immersing a substrate in the saturated solution melt; supersaturating the solution by lowering the temperature of the saturated solution melt and holding the substrate immersed in the solution melt for a period of time sufficient to cause growing Si to precipitate out of the solution to form a crystalline layer of Si on the substrate; and withdrawing the substrate from the solution.

  12. 14.11.05 RH Stabilized Si Microwire - JCAP

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

    Stabilized Si Microwire Arrays for Solar-Driven H2O Oxidation Shaner, M. R., Hu, S., Sun, ... O2 for >2200 h with near 100% Faradaic efficiency under simulated 1 Sun illumination. ...

  13. SiXtron Advanced Materials Inc | Open Energy Information

    Open Energy Info (EERE)

    to: navigation, search Name: SiXtron Advanced Materials Inc Place: Dorval, Quebec, Canada Zip: H9P 1J1 Product: Canadian manufacturer of anti-reflective coating capital...

  14. SiLas GmbH | Open Energy Information

    Open Energy Info (EERE)

    Product: Laser technology development enterprise specialising in the processing of thin-film silicon coating. References: SiLas GmbH1 This article is a stub. You can help...

  15. UFD Storage and Transportation - Transportation Working Group Report

    SciTech Connect (OSTI)

    Maheras, Steven J.; Ross, Steven B.

    2011-08-01

    The Used Fuel Disposition (UFD) Transportation Task commenced in October 2010. As its first task, Pacific Northwest National Laboratory (PNNL) compiled a list of structures, systems, and components (SSCs) of transportation systems and their possible degradation mechanisms during extended storage. The list of SSCs and the associated degradation mechanisms [known as features, events, and processes (FEPs)] were based on the list of used nuclear fuel (UNF) storage system SSCs and degradation mechanisms developed by the UFD Storage Task (Hanson et al. 2011). Other sources of information surveyed to develop the list of SSCs and their degradation mechanisms included references such as Evaluation of the Technical Basis for Extended Dry Storage and Transportation of Used Nuclear Fuel (NWTRB 2010), Transportation, Aging and Disposal Canister System Performance Specification, Revision 1 (OCRWM 2008), Data Needs for Long-Term Storage of LWR Fuel (EPRI 1998), Technical Bases for Extended Dry Storage of Spent Nuclear Fuel (EPRI 2002), Used Fuel and High-Level Radioactive Waste Extended Storage Collaboration Program (EPRI 2010a), Industry Spent Fuel Storage Handbook (EPRI 2010b), and Transportation of Commercial Spent Nuclear Fuel, Issues Resolution (EPRI 2010c). SSCs include items such as the fuel, cladding, fuel baskets, neutron poisons, metal canisters, etc. Potential degradation mechanisms (FEPs) included mechanical, thermal, radiation and chemical stressors, such as fuel fragmentation, embrittlement of cladding by hydrogen, oxidation of cladding, metal fatigue, corrosion, etc. These degradation mechanisms are discussed in Section 2 of this report. The degradation mechanisms have been evaluated to determine if they would be influenced by extended storage or high burnup, the need for additional data, and their importance to transportation. These categories were used to identify the most significant transportation degradation mechanisms. As expected, for the most part, the

  16. Interim UFD Storage and Transportation - Transportation Working Group Report

    SciTech Connect (OSTI)

    Maheras, Steven J.; Ross, Steven B.

    2011-03-30

    The Used Fuel Disposition (UFD) Transportation Task commenced in October 2010. As its first task, Pacific Northwest National Laboratory (PNNL) compiled a draft list of structures, systems, and components (SSCs) of transportation systems and their possible degradation mechanisms during very long term storage (VLTS). The list of SSCs and the associated degradation mechanisms [known as features, events, and processes (FEPs)] were based on the list of SSCs and degradation mechanisms developed by the UFD Storage Task (Stockman et al. 2010)

  17. Quantum transport through aromatic molecules

    SciTech Connect (OSTI)

    Ojeda, J. H.; Rey-Gonzlez, R. R.; Laroze, D.

    2013-12-07

    In this paper, we study the electronic transport properties through aromatic molecules connected to two semi-infinite leads. The molecules are in different geometrical configurations including arrays. Using a nearest neighbor tight-binding approach, the transport properties are analyzed into a Green's function technique within a real-space renormalization scheme. We calculate the transmission probability and the Current-Voltage characteristics as a function of a molecule-leads coupling parameter. Our results show different transport regimes for these systems, exhibiting metal-semiconductor-insulator transitions and the possibility to employ them in molecular devices.

  18. Pretreatment of coal during transport

    DOE Patents [OSTI]

    Johnson, Glenn E.; Neilson, Harry B.; Forney, Albert J.; Haynes, William P.

    1977-04-19

    Many available coals are "caking coals" which possess the undesirable characteristic of fusing into a solid mass when heated through their plastic temperature range (about 400.degree. C.) which temperature range is involved in many common treatment processes such as gasification, hydrogenation, carbonization and the like. Unless the caking properties are first destroyed, the coal cannot be satisfactorily used in such processes. A process is disclosed herein for decaking finely divided coal during its transport to the treating zone by propelling the coal entrained in an oyxgen-containing gas through a heated transport pipe whereby the separate transport and decaking steps of the prior art are combined into a single step.

  19. Thermal decomposition of silane to form hydrogenated amorphous Si film

    DOE Patents [OSTI]

    Strongin, Myron; Ghosh, Arup K.; Wiesmann, Harold J.; Rock, Edward B.; Lutz, III, Harry A.

    1980-01-01

    This invention relates to hydrogenated amorphous silicon produced by thermally decomposing silano (SiH.sub.4) or other gases comprising H and Si, at elevated temperatures of about 1700.degree.-2300.degree. C., and preferably in a vacuum of about 10.sup.-8 to 10.sup.-4 torr, to form a gaseous mixture of atomic hydrogen and atomic silicon, and depositing said gaseous mixture onto a substrate outside said source of thermal decomposition to form hydrogenated amorphous silicon.

  20. Thermal decomposition of silane to form hydrogenated amorphous Si

    DOE Patents [OSTI]

    Strongin, M.; Ghosh, A.K.; Wiesmann, H.J.; Rock, E.B.; Lutz, H.A. III

    Hydrogenated amorphous silicon is produced by thermally decomposing silane (SiH/sub 4/) or other gases comprising H and Si, at elevated temperatures of about 1700 to 2300/sup 0/C, in a vacuum of about 10/sup -8/ to 10/sup -4/ torr. A gaseous mixture is formed of atomic hydrogen and atomic silicon. The gaseous mixture is deposited onto a substrate to form hydrogenated amorphous silicon.

  1. Oxygen Transport Ceramic Membranes

    SciTech Connect (OSTI)

    S. Bandopadhyay; N. Nagabhushana; Thomas W. Eagar; Harold R. Larson; Raymundo Arroyave; X.-D Zhou; Y.-W. Shin; H.U. Anderson; Nigel Browning; Alan Jacobson; C.A. Mims

    2003-11-01

    The present quarterly report describes some of the initial studies on newer compositions and also includes newer approaches to address various materials issues such as in metal-ceramic sealing. The current quarter's research has also focused on developing a comprehensive reliability model for predicting the structural behavior of the membranes in realistic conditions. In parallel to industry provided compositions, models membranes have been evaluated in varying environment. Of importance is the behavior of flaws and generation of new flaws aiding in fracture. Fracture mechanics parameters such as crack tip stresses are generated to characterize the influence of environment. Room temperature slow crack growth studies have also been initiated in industry provided compositions. The electrical conductivity and defect chemistry of an A site deficient compound (La{sub 0.55}Sr{sub 0.35}FeO{sub 3}) was studied. A higher conductivity was observed for La{sub 0.55}Sr{sub 0.35}FeO{sub 3} than that of La{sub 0.60}Sr{sub 0.40}FeO{sub 3} and La{sub 0.80}Sr{sub 0.20}FeO{sub 3}. Defect chemistry analysis showed that it was primarily contributed by a higher carrier concentration in La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. Moreover, the ability for oxygen vacancy generation is much higher in La{sub 0.55}Sr{sub 0.35}FeO{sub 3} as well, which indicates a lower bonding strength between Fe-O and a possible higher catalytic activity for La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. The program continued to investigate the thermodynamic properties (stability and phase separation behavior) and total conductivity of prototype membrane materials. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previous report listed initial measurements on a sample of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-x} prepared in-house by Praxair. Subsequently, a second sample of powder from a larger batch of sample were characterized and compared with

  2. Oxygen Transport Ceramic Membranes

    SciTech Connect (OSTI)

    S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

    2004-10-01

    The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, Moessbauer spectroscopy was used to study the local environmentals of LSFT with various level of oxygen deficiency. Ionic valence state, magnetic interaction and influence of Ti on superexchange are discussed Stable crack growth studies on Dense OTM bars provided by Praxair were done at elevated temperature, pressure and elevated conditions. Post-fracture X-ray data of the OTM fractured at 1000 C in environment were refined by FullProf code and results indicate a distortion of the parent cubic perovskite to orthorhombic structure with reduced symmetry. TGA-DTA studies on the post-fracture samples also indicated residual effect arising from the thermal and stress history of the samples. An electrochemical cell has been designed and built for measurements of the Seebeck coefficient as a function of temperature and pressure. The initial measurements on La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} are reported. Neutron diffraction measurements of the same composition are in agreement with both the stoichiometry and the kinetic behavior observed in coulometric titration measurements. A series of isotope transients under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The COCO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

  3. Oxygen Transport Ceramic Membranes

    SciTech Connect (OSTI)

    S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

    2004-05-01

    The present quarterly report describes some of the investigations on the structural properties of dense OTM bars provided by Praxair and studies on newer composition of Ti doped LSF. In this report, in situ neutron diffraction was used to characterize the chemical and structural properties of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} (here after as L2SF55T) specimen, which was subject to measurements of neutron diffraction from room temperature to 900 C. It was found that space group of R3c yielded a better refinement than a cubic structure of Pm3m. Oxygen occupancy was nearly 3 in the region from room temperature to 700 C, above which the occupancy decreased due to oxygen loss. Dense OTM bars provided by Praxair were loaded to fracture at varying stress rates. Studies were done at room temperature in air and at 1000 C in a specified environment to evaluate slow crack growth behavior. The X-Ray data and fracture mechanisms points to non-equilibrium decomposition of the LSFCO OTM membrane. The non-equilibrium conditions could probably be due to the nature of the applied stress field (stressing rates) and leads to transition in crystal structures and increased kinetics of decomposition. The formations of a Brownmillerite or Sr2Fe2O5 type structures, which are orthorhombic are attributed to the ordering of oxygen vacancies. The cubic to orthorhombic transitions leads to 2.6% increase in strains and thus residual stresses generated could influence the fracture behavior of the OTM membrane. Continued investigations on the thermodynamic properties (stability and phase-separation behavior) and total conductivity of prototype membrane materials were carried out. The data are needed together with the kinetic information to develop a complete model for the membrane transport. Previously characterization, stoichiometry and conductivity measurements for samples of La{sub 0.2}Sr{sub 0.8}Fe{sub 0.55}Ti{sub 0.45}O{sub 3-{delta}} were reported. In this report

  4. Uranium Transport Modeling

    SciTech Connect (OSTI)

    Bostick, William D.

    2008-01-15

    mineral phases. Four case studies are presented: Water and Soil Characterization, Subsurface Stabilization of Uranium and other Toxic Metals, Reductive Precipitation (in situ bioremediation) of Uranium, and Physical Transport of Particle-bound Uranium by Erosion.

  5. Quantum confinement in Si and Ge nanostructures: Theory and experiment

    SciTech Connect (OSTI)

    Barbagiovanni, Eric G.; Lockwood, David J.; Simpson, Peter J.; Goncharova, Lyudmila V.

    2014-03-15

    The role of quantum confinement (QC) in Si and Ge nanostructures (NSs) including quantum dots, quantum wires, and quantum wells is assessed under a wide variety of fabrication methods in terms of both their structural and optical properties. Structural properties include interface states, defect states in a matrix material, and stress, all of which alter the electronic states and hence the measured optical properties. We demonstrate how variations in the fabrication method lead to differences in the NS properties, where the most relevant parameters for each type of fabrication method are highlighted. Si embedded in, or layered between, SiO{sub 2}, and the role of the sub-oxide interface states embodies much of the discussion. Other matrix materials include Si{sub 3}N{sub 4} and Al{sub 2}O{sub 3}. Si NSs exhibit a complicated optical spectrum, because the coupling between the interface states and the confined carriers manifests with varying magnitude depending on the dimension of confinement. Ge NSs do not produce well-defined luminescence due to confined carriers, because of the strong influence from oxygen vacancy defect states. Variations in Si and Ge NS properties are considered in terms of different theoretical models of QC (effective mass approximation, tight binding method, and pseudopotential method). For each theoretical model, we discuss the treatment of the relevant experimental parameters.

  6. Boron diffusion in nanocrystalline 3C-SiC

    SciTech Connect (OSTI)

    Schnabel, Manuel; Weiss, Charlotte; Rachow, Thomas; Löper, Philipp; Janz, Stefan; Canino, Mariaconcetta; Summonte, Caterina; Mirabella, Salvo; Wilshaw, Peter R.

    2014-05-26

    The diffusion of boron in nanocrystalline silicon carbide (nc-SiC) films with a grain size of 4–7 nm is studied using a poly-Si boron source. Diffusion is found to be much faster than in monocrystalline SiC as it takes place within the grain boundary (GB) network. Drive-in temperatures of 900–1000°C are suitable for creating shallow boron profiles up to 100 nm deep, while 1100°C is sufficient to flood the 200 nm thick films with boron. From the resulting plateau at 1100 °C a boron segregation coefficient of 28 between nc-SiC and the Si substrate, as well as a GB boron solubility limit of 0.2 nm{sup −2} is determined. GB diffusion in the bulk of the films is Fickian and thermally activated with D{sub GB}(T)=(3.1−5.6)×10{sup 7}exp(−5.03±0.16  eV/k{sub B}T) cm{sup 2}s{sup −1}. The activation energy is interpreted in terms of a trapping mechanism at dangling bonds. Higher boron concentrations are present at the nc-SiC surface and are attributed to immobilized boron.

  7. SiAlON ceramic compositions and methods of fabrication

    DOE Patents [OSTI]

    O'Brien, M.H.; Park, B.H.

    1994-05-31

    A method of fabricating a SiAlON ceramic body includes: (a) combining quantities of Si[sub 3]N[sub 4], Al[sub 2]O[sub 3] and CeO[sub 2] to produce a mixture; (b) forming the mixture into a desired body shape; (c) heating the body to a densification temperature of from about 1,550 C to about 1,850 C; (d) maintaining the body at the densification temperature for a period of time effective to densify the body; (e) cooling the densified body to a devitrification temperature of from about 1,200 C to about 1,400 C; and (f) maintaining the densified body at the devitrification temperature for a period of time effective to produce a [beta][prime]-SiAlON crystalline phase in the body having elemental or compound form Ce incorporated in the [beta][prime]-SiAlON crystalline phase. Further, a SiAlON ceramic body comprises: (a) an amorphous phase; and (b) a crystalline phase, the crystalline phase comprising [beta][prime]-SiAlON having lattice substituted elemental or compound form Ce.

  8. Synthesis and characterization in AuCu–Si nanostructures

    SciTech Connect (OSTI)

    Novelo, T.E.; Amézaga-Madrid, P.; Maldonado, R.D.; Oliva, A.I.; Alonzo-Medina, G.M.

    2015-03-15

    Au/Cu bilayers with different Au:Cu concentrations (25:75, 50:50 and 75:25 at.%) were deposited on Si(100) substrates by thermal evaporation. The thicknesses of all Au/Cu bilayers were 150 nm. The alloys were prepared by thermal diffusion into a vacuum oven with argon atmosphere at 690 K during 1 h. X-ray diffraction analysis revealed different phases of AuCu and CuSi alloys in the samples after annealing process. CuSi alloys were mainly obtained for 25:75 at.% samples, meanwhile the AuCuII phase dominates for samples prepared with 50:50 at.%. Additionally, the Au:Cu alloys with 75:25 at.%, produce Au{sub 2}Cu{sub 3} and Au{sub 3}Cu phases. The formed alloys were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) to study the morphology and the elemental concentration of the formed alloys. - Highlights: • AuCu/Si alloy thin films were prepared by thermal diffusion. • Alloys prepared with 50 at.% of Au produce the AuCuII phase. • Alloys prepared with 75 at.% of Au produce Au{sub 3}Cu and Au{sub 2}Cu{sub 3} phases. • All alloys present diffusion of Si and Cu through the CuSi alloy formation.

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

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

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

    2011-01-13

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

  10. SiN{sub x} layers on nanostructured Si solar cells: Effective for optical absorption and carrier collection

    SciTech Connect (OSTI)

    Cho, Yunae; Kim, Eunah; Gwon, Minji; Kim, Dong-Wook E-mail: dwkim@ewha.ac.kr; Park, Hyeong-Ho; Kim, Joondong E-mail: dwkim@ewha.ac.kr

    2015-10-12

    We compared nanopatterned Si solar cells with and without SiN{sub x} layers. The SiN{sub x} layer coating significantly improved the internal quantum efficiency of the nanopatterned cells at long wavelengths as well as short wavelengths, whereas the surface passivation helped carrier collection of flat cells mainly at short wavelengths. The surface nanostructured array enhanced the optical absorption and also concentrated incoming light near the surface in broad wavelength range. Resulting high density of the photo-excited carriers near the surface could lead to significant recombination loss and the SiN{sub x} layer played a crucial role in the improved carrier collection of the nanostructured solar cells.

  11. All-epitaxial Co{sub 2}FeSi/Ge/Co{sub 2}FeSi trilayers fabricated...

    Office of Scientific and Technical Information (OSTI)

    Ge and Cosub 2FeSi enable to promote the 2D epitaxial growth of Ge up to 5 nm at a ... Country of Publication: United States Language: English Subject: 36 MATERIALS SCIENCE; 71 ...

  12. Radial quasiballistic transport in time-domain thermoreflectance studied using Monte Carlo simulations

    SciTech Connect (OSTI)

    Ding, D.; Chen, X.; Minnich, A. J.

    2014-04-07

    Recently, a pump beam size dependence of thermal conductivity was observed in Si at cryogenic temperatures using time-domain thermal reflectance (TDTR). These observations were attributed to quasiballistic phonon transport, but the interpretation of the measurements has been semi-empirical. Here, we present a numerical study of the heat conduction that occurs in the full 3D geometry of a TDTR experiment, including an interface, using the Boltzmann transport equation. We identify the radial suppression function that describes the suppression in heat flux, compared to Fourier's law, that occurs due to quasiballistic transport and demonstrate good agreement with experimental data. We also discuss unresolved discrepancies that are important topics for future study.

  13. co2-transport | netl.doe.gov

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

    Transport Cost Model FENETL CO2 Transport Cost Model About the model: This model was developed to estimate the cost of transporting a user-specified mass rate of CO2 by pipeline...

  14. DOT Awards University Transportation Centers $63 Million

    Broader source: Energy.gov [DOE]

    The U.S. Department of Transportation's (DOT) announced approximately $63 million in grants to 33 University Transportation Centers to advance research and education programs that address critical transportation challenges.

  15. National Transportation Stakeholders Forum (NTSF)

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy (DOE) National Transportation Stakeholders Forum (NTSF) is the mechanism through which DOE communicates at a national level with states and tribes about the Department...

  16. Transportation Sector Module - NEMS Documentation

    Reports and Publications (EIA)

    2014-01-01

    Documents the objectives, analytical approach and development of the National Energy Modeling System (NEMS) Transportation Model (TRAN). The report catalogues and describes the model assumptions, computational methodology, parameter estimation techniques, model source code, and forecast results generated by the model.

  17. Office of Secure Transportation Activities

    Broader source: Energy.gov [DOE]

    Our MissionTo provide safe and secure ground and air transportation of nuclear weapons, nuclear weapons components, and special nuclear materials and conduct other missions supporting the national...

  18. NREL: Transportation Research - Success Stories

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

    Success Stories NREL understands real-world factors impacting industry and consumer adoption of sustainable transportation solutions, resulting in an impressive record of breaking down barriers to accelerate development and deployment of new transportation technologies. The success stories below provide a snapshot of how NREL research, development, and deployment activities translate into more energy-efficient vehicles and cleaner burning fuels, providing viable options to meet the needs of

  19. NREL: Transportation Research Home Page

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

    Transportation Research Silver Toyota Prius being driven in front of NREL entrance sign. NREL helps industry partners develop the next generation of energy efficient, high performance vehicles and fuels. Thermal image of two men standing in front of tractor trailer cab. NREL conducts research on the full range of vehicle types, from light-duty passenger cars to heavy-duty freight trucks. Female researcher holding coin cell battery. NREL's transportation research spans from the materials to the

  20. Deterministic methods in radiation transport

    SciTech Connect (OSTI)

    Rice, A.F.; Roussin, R.W.

    1992-06-01

    The Seminar on Deterministic Methods in Radiation Transport was held February 4--5, 1992, in Oak Ridge, Tennessee. Eleven presentations were made and the full papers are published in this report, along with three that were submitted but not given orally. These papers represent a good overview of the state of the art in the deterministic solution of radiation transport problems for a variety of applications of current interest to the Radiation Shielding Information Center user community.

  1. How Antidepressants Block Serotonin Transport

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

    How Antidepressants Block Serotonin Transport How Antidepressants Block Serotonin Transport Print Tuesday, 12 July 2016 00:00 Serotonin is a diminutive and deceptively simple-looking neurotransmitter molecule, yet a very complex "machinery" is required for neurotransmitter recognition, transmission, and recycling. The malfunctioning of this protein machinery can cause conditions such as depression, obsessive-compulsive disorder, aggression, anxiety, and Parkinson's disease. In

  2. transportation-systems-modeling-training

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

    Training Table of Contents Date Location Integrated Transportation Models Workshop at ITM 2012 April 29, 2012 Hyatt Regency Tampa, FL TRANSIMS Training Course April 14-15, 2011 James E. Clyburn University Transportation Center Orangeburg, SC TRANSIMS RTSTEP Guest Lecturer March 29, 2011 Argonne TRACC Argonne, IL TRANSIMS Training Course January 19-21 2011 Argonne TRACC Argonne, IL TRANSIMS Training Course September 7-8, 2010 Turner Fairbank Highway Research Center Washington D.C. Network

  3. PADD 5 Transportation Fuels Markets

    U.S. Energy Information Administration (EIA) Indexed Site

    PADD 5 Transportation Fuels Markets September 2015 Independent Statistics & Analysis www.eia.gov U.S. Department of Energy Washington, DC 20585 U.S. Energy Information Administration | PADD 5 Transportation Fuels Markets i This report was prepared by the U.S. Energy Information Administration (EIA), the statistical and analytical agency within the U.S. Department of Energy. By law, EIA's data, analyses, and forecasts are independent of approval by any other officer or employee of the United

  4. Forage Harvest and Transport Costs

    SciTech Connect (OSTI)

    Butler, J.; Downing, M.; Turhollow, A.

    1998-12-01

    An engineering-economic approach is used to calculate harvest, in-field transport, and over-the-road transport costs for hay as bales and modules, silage, and crop residues as bales and modules. Costs included are equipment depreciation interest; fuel, lube, and oil; repairs; insurance, housing, and taxes; and labor. Field preparation, pest control, fertilizer, land, and overhead are excluded from the costs calculated Equipment is constrained by power available, throughput or carrying capacity, and field speed.

  5. Air Transport Optimization Model | NISAC

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

    NISACAir Transport Optimization Model content top Network Optimization Models (RNAS and ATOM) Posted by Admin on Mar 1, 2012 in | Comments 0 comments Many critical infrastructures can be represented by a network of interconnected nodes and links. Mathematically sound nonlinear optimization techniques can then be applied to these networks to understand their behavior under normal and disrupted situations. Network optimization models are particularly useful for evaluating transportation system

  6. Panel 4 - applications to transportation

    SciTech Connect (OSTI)

    Nichols, F.; Au, J.; Bhattacharya, R.; Bhushan, B.; Blunier, D.; Boardman, B.; Brombolich, L.; Davidson, J.; Graham, M.; Hakim, N.; Harris, K.; Hay, R.; Herk, L.; Hojnacki, H.; Rourk, D.; Kamo, R.; Nieman, B.; O`Neill, D.; Peterson, M.B.; Pfaffenberger, G.; Pryor, R.W.; Russell, J.; Syniuta, W.; Tamor, M.; Vojnovich, T.; Yarbrough, W.; Yust, C.S.

    1993-01-01

    The aim of this group was to compile a listing of current and anticipated future problem areas in the transportation industry where the properties of diamond and DLC films make them especially attractive and where the panel could strongly endorse the establishment of DOE/Transportation Industry cooperative research efforts. This section identifies the problem areas for possible applications of diamond/DLC technology and presents indications of current approaches to these problems.

  7. Structural and photovoltaic properties of a-Si (SNc)/c-Si heterojunction fabricated by EBPVD technique

    SciTech Connect (OSTI)

    Demiro?lu, D.; Kazmanli, K.; Urgen, M.; Tatar, B.

    2013-12-16

    In last two decades sculptured thin films are very attractive for researches. Some properties of these thin films, like high porosity correspondingly high large surface area, controlled morphology; bring into prominence on them. Sculptured thin films have wide application areas as electronics, optics, mechanics, magnetic and chemistry. Slanted nano-columnar (SnC) thin films are a type of sculptured thin films. In this investigation SnC thin films were growth on n-type crystalline Si(100) and p-type crystalline Si(111) via ultra-high vacuum electron beam evaporation technique. The structural and morphological properties of the amorphous silicon thin films were investigated by XRD, Raman and FE-SEM analysis. According to the XRD and Raman analysis the structure of thin film was amorphous and FE-SEM analysis indicated slanted nano-columns were formed smoothly. Slanted nano-columns a-Si/c-Si heterojunction were prepared as using a photovoltaic device. In this regard we were researched photovoltaic properties of these heterojunction with current-voltage characterization under dark and illumination conditions. Electrical parameters were determined from the current-voltage characteristic in the dark conditions zero-bias barrier height ?{sub B0}?=?0.83?1.00eV; diode ideality factor ??=?11.71?10.73; series resistance R{sub s}?=?260?31.1 k? and shunt resistance R{sub sh}?=?25.71?63.5 M? SnC a-Si/n-Si and SnC a-Si/p-Si heterojunctions shows a pretty good photovoltaic behavior about 10{sup 3}- 10{sup 4} times. The obtained photovoltaic parameters are such as short circuit current density J{sub sc} 83-40 mA/m{sup 2}, open circuit voltage V{sub oc} 900-831 mV.

  8. Properties of Si{sub n}, Ge{sub n}, and Si{sub n}Ge{sub n} clusters

    SciTech Connect (OSTI)

    Dong, Yi; Rehman, Habib ur; Springborg, Michael

    2015-01-22

    The structures of Si{sub n}, Ge{sub n}, and Si{sub n}Ge{sub n} clusters with up to 44 atoms have been determined theoretically using an unbiased structure-optimization method in combination with a parametrized, density-functional description of the total energy for a given structure. By analyzing the total energy in detail, particularly stable clusters are identified. Moreover, general trends in the structures are identified with the help of specifically constructed descriptors.

  9. Alternative Fuels Data Center: Transportation System Efficiency

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

    Transportation System Efficiency to someone by E-mail Share Alternative Fuels Data Center: Transportation System Efficiency on Facebook Tweet about Alternative Fuels Data Center: Transportation System Efficiency on Twitter Bookmark Alternative Fuels Data Center: Transportation System Efficiency on Google Bookmark Alternative Fuels Data Center: Transportation System Efficiency on Delicious Rank Alternative Fuels Data Center: Transportation System Efficiency on Digg Find More places to share

  10. Apparatus for transporting hazardous materials

    DOE Patents [OSTI]

    Osterman, Robert A.; Cox, Robert

    1992-01-01

    An apparatus and method are provided for selectively receiving, transporting, and releasing one or more radioactive or other hazardous samples for analysis on a differential thermal analysis (DTA) apparatus. The apparatus includes a portable sample transporting apparatus for storing and transporting the samples and includes a support assembly for supporting the transporting apparatus when a sample is transferred to the DTA apparatus. The transporting apparatus includes a storage member which includes a plurality of storage chambers arrayed circumferentially with respect to a central axis. An adjustable top door is located on the top side of the storage member, and the top door includes a channel capable of being selectively placed in registration with the respective storage chambers thereby permitting the samples to selectively enter the respective storage chambers. The top door, when closed, isolates the respective samples within the storage chambers. A plurality of spring-biased bottom doors are located on the bottom sides of the respective storage chambers. The bottom doors isolate the samples in the respective storage chambers when the bottom doors are in the closed position. The bottom doors permit the samples to leave the respective storage chambers from the bottom side when the respective bottom doors are in respective open positions. The bottom doors permit the samples to be loaded into the respective storage chambers after the analysis for storage and transport to a permanent storage location.

  11. Transportation scenarios for risk analysis.

    SciTech Connect (OSTI)

    Weiner, Ruth F.

    2010-09-01

    Transportation risk, like any risk, is defined by the risk triplet: what can happen (the scenario), how likely it is (the probability), and the resulting consequences. This paper evaluates the development of transportation scenarios, the associated probabilities, and the consequences. The most likely radioactive materials transportation scenario is routine, incident-free transportation, which has a probability indistinguishable from unity. Accident scenarios in radioactive materials transportation are of three different types: accidents in which there is no impact on the radioactive cargo, accidents in which some gamma shielding may be lost but there is no release of radioactive material, and accident in which radioactive material may potentially be released. Accident frequencies, obtainable from recorded data validated by the U.S. Department of Transportation, are considered equivalent to accident probabilities in this study. Probabilities of different types of accidents are conditional probabilities, conditional on an accident occurring, and are developed from event trees. Development of all of these probabilities and the associated highway and rail accident event trees are discussed in this paper.

  12. Oxygen Transport Ceramic Membranes

    SciTech Connect (OSTI)

    S. Bandopadhyay; N. Nagabhushana; X.-D Zhou; Q. Cai; J. Yang; W.B. Yelon; W.J. James; H.U. Anderson; Alan Jacobson; C.A. Mims

    2004-05-01

    the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

  13. Oxygen Transport Ceramic Membranes

    SciTech Connect (OSTI)

    S. Bandopadhyay; N. Nagabhushana; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2005-02-01

    under air separation mode (small gradient) were completed on the membrane of LSCrF-2828 at 900 C. Low pO{sub 2} atmospheres based on with CO-CO{sub 2} mixtures have also been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

  14. Hydrogen intercalation of single and multiple layer graphene synthesized on Si-terminated SiC(0001) surface

    SciTech Connect (OSTI)

    So?tys, Jakub; Piechota, Jacek; Ptasinska, Maria; Krukowski, Stanis?aw

    2014-08-28

    Ab initio density functional theory simulations were used to investigate the influence of hydrogen intercalation on the electronic properties of single and multiple graphene layers deposited on the SiC(0001) surface (Si-face). It is shown that single carbon layer, known as a buffer layer, covalently bound to the SiC substrate, is liberated after hydrogen intercalation, showing characteristic Dirac cones in the band structure. This is in agreement with the results of angle resolved photoelectron spectroscopy measurements of hydrogen intercalation of SiC-graphene samples. In contrast to that hydrogen intercalation has limited impact on the multiple sheet graphene, deposited on Si-terminated SiC surface. The covalently bound buffer layer is liberated attaining its graphene like structure and dispersion relation typical for multilayer graphene. Nevertheless, before and after intercalation, the four layer graphene preserved the following dispersion relations in the vicinity of K point: linear for (AAAA) stacking, direct parabolic for Bernal (ABAB) stacking and wizard hat parabolic for rhombohedral (ABCA) stacking.

  15. Effect of rapid thermal annealing temperature on the dispersion of Si nanocrystals in SiO{sub 2} matrix

    SciTech Connect (OSTI)

    Saxena, Nupur Kumar, Pragati; Gupta, Vinay

    2015-05-15

    Effect of rapid thermal annealing temperature on the dispersion of silicon nanocrystals (Si-NCs) embedded in SiO{sub 2} matrix grown by atom beam sputtering (ABS) method is reported. The dispersion of Si NCs in SiO{sub 2} is an important issue to fabricate high efficiency devices based on Si-NCs. The transmission electron microscopy studies reveal that the precipitation of excess silicon is almost uniform and the particles grow in almost uniform size upto 850 C. The size distribution of the particles broadens and becomes bimodal as the temperature is increased to 950 C. This suggests that by controlling the annealing temperature, the dispersion of Si-NCs can be controlled. The results are supported by selected area diffraction (SAED) studies and micro photoluminescence (PL) spectroscopy. The discussion of effect of particle size distribution on PL spectrum is presented based on tight binding approximation (TBA) method using Gaussian and log-normal distribution of particles. The study suggests that the dispersion and consequently emission energy varies as a function of particle size distribution and that can be controlled by annealing parameters.

  16. Transport Research Laboratory | Open Energy Information

    Open Energy Info (EERE)

    Research Laboratory Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Transport Research Laboratory AgencyCompany Organization: Transport Research Laboratory Focus Area:...

  17. Anion Exchange Membranes - Transport/Conductivity | Department...

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

    - TransportConductivity Anion Exchange Membranes - TransportConductivity Presentation at the AMFC Workshop, May 8-9, 2011, Arlington, VA PDF icon amfc110811aemstransport.pdf ...

  18. Transport NAMA Database | Open Energy Information

    Open Energy Info (EERE)

    Website: www.transport-namadatabase.orgindex.phpMainPage Transport Toolkit Region(s): Latin America & Caribbean, Africa & Middle East, Europe, Asia Related Tools Climate...

  19. APEC-Alternative Transport Fuels: Implementation Guidelines ...

    Open Energy Info (EERE)

    APEC-Alternative Transport Fuels: Implementation Guidelines Jump to: navigation, search Tool Summary LAUNCH TOOL Name: APEC-Alternative Transport Fuels: Implementation Guidelines...

  20. Asian Development Bank - Transport | Open Energy Information

    Open Energy Info (EERE)

    sectorstransportmain Transport Toolkit Region(s): Asia Related Tools TRANSfer - Towards climate-friendly transport technologies and measures List of Publications from GIZ...

  1. Secure Transportation_final_print-ready

    Office of Environmental Management (EM)

    made by Hittman Transport, a commercial carrier * Hittman Transport is a specialty ... of the requirements of the Department of Energy, Nuclear Regulatory Commission, and ...

  2. Transport Modeling Working Group Meeting Reports | Department...

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

    Modeling Working Group Meeting Reports Transport Modeling Working Group Meeting Reports View reports from meetings of the Transport Modeling Working Group, which meets twice per ...

  3. Renewable Transportation Fuels | Open Energy Information

    Open Energy Info (EERE)

    Transportation Fuels Jump to: navigation, search TODO: Add description List of Renewable Transportation Fuels Incentives Retrieved from "http:en.openei.orgw...

  4. DECONTAMINATION DRESSDOWN AT A TRANSPORTATION ACCIDENT INVOLVING...

    Office of Environmental Management (EM)

    Video User' s Guide DECONTAMINATION DRESSDOWN AT A TRANSPORTATION ACCIDENT INVOLVING ... related to emergency response to a transportation accident involving radioactive material. ...

  5. Electric Drive Transportation Association EDTA | Open Energy...

    Open Energy Info (EERE)

    Transportation Association EDTA Jump to: navigation, search Name: Electric Drive Transportation Association (EDTA) Product: EDTA is the preeminent U.S. industry association...

  6. COMBINED MODELING OF ACCELERATION, TRANSPORT, AND HYDRODYNAMIC...

    Office of Scientific and Technical Information (OSTI)

    Title: COMBINED MODELING OF ACCELERATION, TRANSPORT, AND HYDRODYNAMIC RESPONSE IN SOLAR FLARES. I. THE NUMERICAL MODEL Acceleration and transport of high-energy particles and fluid ...

  7. Analysis of Transportation and Logistics Challenges Affecting...

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

    Analysis of Transportation and Logistics Challenges Affecting the Deployment of Larger Wind Turbines: Summary of Results Analysis of Transportation and Logistics Challenges ...

  8. Los Angeles County Metropolitan Transportation Authority Metro...

    Open Energy Info (EERE)

    County Metropolitan Transportation Authority Metro Jump to: navigation, search Name: Los Angeles County Metropolitan Transportation Authority (Metro) Place: Los Angeles, California...

  9. Nevada Department of Transportation | Open Energy Information

    Open Energy Info (EERE)

    of Transportation Name: Nevada Department of Transportation Address: 1263 S. Stewart St. Place: Carson City, Nevada Zip: 89712 Phone Number: 775-888-7000 Website:...

  10. Transportation and Stationary Power Integration Workshop Attendees...

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

    Transportation and Stationary Power Integration Workshop Attendees List List of attendees for the Transportation and Stationary Power Integration Workshop PDF icon ...

  11. ADMINISTRATIVE RECORDS SCHEDULE 9: TRAVEL AND TRANSPORTATION...

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

    9: TRAVEL AND TRANSPORTATION RECORDS (Revision 2) ADMINISTRATIVE RECORDS SCHEDULE 9: TRAVEL AND TRANSPORTATION RECORDS (Revision 2) This schedule covers records documenting the ...

  12. DOE - NNSA/NFO -- EM Transportation Reports

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

    Transportation Reports NNSANFO Language Options U.S. DOENNSA - Nevada Field Office Click to subscribe to NNSS News Transportation Reports Click the document title to view or ...

  13. Transportation Energy Data Book | Open Energy Information

    Open Energy Info (EERE)

    for use as a desk-top reference, the Transportation Energy Data Book provides statistics and information characterizing transportation activity and energy use. The book...

  14. Sustainable Transportation and National Parks Initiative Featured...

    Energy Savers [EERE]

    Sustainable Transportation and National Parks Initiative Featured in Magazine Sustainable Transportation and National Parks Initiative Featured in Magazine October 18, 2013 - ...

  15. Sustainable Transportation Summit | Department of Energy

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

    This year's summit will highlight progress and achievements in sustainable transportation ... Register and find more information at the Sustainable Transportation Summit website. ...

  16. Hydrogen transport in composite inorganic membranes (Journal...

    Office of Scientific and Technical Information (OSTI)

    Hydrogen transport in composite inorganic membranes Citation Details In-Document Search Title: Hydrogen transport in composite inorganic membranes A theoretical model simulating ...

  17. Water Transport Exploratory Studies | Department of Energy

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

    Exploratory Studies Water Transport Exploratory Studies This presentation, which focuses on water transport exploratory studies, was given by Rod Borup of Los Alamos National ...

  18. Climate Adaptation for Transportation | Open Energy Information

    Open Energy Info (EERE)

    Climate Adaptation for Transportation (Redirected from 03 Climate Adaptation for Transportation) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: 03 Climate Adaptation...

  19. Climate Adaptation for Transportation | Open Energy Information

    Open Energy Info (EERE)

    Climate Adaptation for Transportation Jump to: navigation, search Tool Summary LAUNCH TOOL Name: 03 Climate Adaptation for Transportation AgencyCompany Organization: AASHTO...

  20. Victoria Transport Policy Institute | Open Energy Information

    Open Energy Info (EERE)

    Transport Policy Institute Jump to: navigation, search Name: Victoria Transport Policy Institute Address: 1250 Rudlin Street, Place: Victoria, British Columbia Website:...

  1. EERE FY 2016 Budget Overview -- Sustainable Transportation |...

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

    Sustainable Transportation EERE FY 2016 Budget Overview -- Sustainable Transportation Office of Energy Efficiency and Renewable Energy FY 2016 Budget Overview -- Sustainable...

  2. Standardization of Transport Properties Measurements: Internal...

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

    Standardization of Transport Properties Measurements: Internal Energy Agency (IEA-AMT) Annex on Thermoelectric International Round-Robin on Transport Properties of Bismuth ...

  3. 2016 DOE Project Management Workshop - Transportation | Department...

    Office of Environmental Management (EM)

    Transportation 2016 DOE Project Management Workshop - Transportation Complimentary guest shuttle service provided by Sheraton Pentagon City Hotel. PDF icon Shuttle service Key ...

  4. Hazardous Materials Packaging and Transportation Safety - DOE...

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

    60.1D, Hazardous Materials Packaging and Transportation Safety by Ashok Kapoor Functional areas: Hazardous Materials, Packaging and Transportation, Safety and Security, Work...

  5. Transportation and Stationary Power Integration Workshop Agenda...

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

    Agenda, October 27, 2008, Phoenix, Arizonia Transportation and Stationary Power Integration Workshop Agenda, October 27, 2008, Phoenix, Arizonia Agenda for the Transportation and ...

  6. Coal Gasification and Transportation Fuels Magazine

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

    Coal Gasification and Transportation Fuels Magazine Current Edition: Coal Gasification and Transportation Fuels Quarterly News, Vol. 2, Issue 3 (April 2016) Archived Editions: Coal ...

  7. Technologies for Climate Change Mitigation: Transport Sector...

    Open Energy Info (EERE)

    Technologies for Climate Change Mitigation: Transport Sector Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Technologies for Climate Change Mitigation: Transport Sector...

  8. Caltrans Transportation Permits Manual | Open Energy Information

    Open Energy Info (EERE)

    Transportation Permits Manual Jump to: navigation, search OpenEI Reference LibraryAdd to library Legal Document- OtherOther: Caltrans Transportation Permits ManualLegal Abstract...

  9. Materials and Transportation Services | The Ames Laboratory

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

    Materials and Transportation Services General Information: Materials and Transportation Services provides Ames Laboratory employees with a wide array of services and support...

  10. Montana Department of Transportation | Open Energy Information

    Open Energy Info (EERE)

    Transportation Name: Montana Department of Transportation Address: 2701 Prospect Avenue P.O. Box 201001 Place: Helena, Montana Zip: 59620 Website: www.mdt.mt.gov Coordinates:...

  11. Electric Transportation Applications All Rights Reserved ETA...

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

    Electric Transportation Applications All Rights Reserved TABLE OF CONTENTS 1.0 Objectives ... Electric Transportation Applications All Rights Reserved 1.0 Objective The objective of ...

  12. Current transport mechanisms in plasma-enhanced atomic layer deposited AlN thin films

    SciTech Connect (OSTI)

    Altuntas, Halit E-mail: biyikli@unam.bilkent.edu.tr; Ozgit-Akgun, Cagla; Donmez, Inci; Biyikli, Necmi E-mail: biyikli@unam.bilkent.edu.tr

    2015-04-21

    Here, we report on the current transport mechanisms in AlN thin films deposited at a low temperature (i.e., 200?C) on p-type Si substrates by plasma-enhanced atomic layer deposition. Structural characterization of the deposited AlN was carried out using grazing-incidence X-ray diffraction, revealing polycrystalline films with a wurtzite (hexagonal) structure. Al/AlN/ p-Si metal-insulator-semiconductor (MIS) capacitor structures were fabricated and investigated under negative bias by performing current-voltage measurements. As a function of the applied electric field, different types of current transport mechanisms were observed; i.e., ohmic conduction (15.221.5 MV/m), Schottky emission (23.639.5 MV/m), Frenkel-Poole emission (63.8211.8 MV/m), trap-assisted tunneling (226280 MV/m), and Fowler-Nordheim tunneling (290447 MV/m). Electrical properties of the insulating AlN layer and the fabricated Al/AlN/p-Si MIS capacitor structure such as dielectric constant, flat-band voltage, effective charge density, and threshold voltage were also determined from the capacitance-voltage measurements.

  13. Washington State Department of Transportation | Open Energy Informatio...

    Open Energy Info (EERE)

    Transportation Jump to: navigation, search Logo: Washington State Department of Transportation Name: Washington State Department of Transportation Abbreviation: WDOT Place:...

  14. Model Recovery Procedure for Response to a Radiological Transportation...

    Office of Environmental Management (EM)

    for Response to a Radiological Transportation Incident Model Recovery Procedure for Response to a Radiological Transportation Incident This Transportation Emergency...

  15. Composites of Upgraded Metallurgical Grade (UMG) Si with Photovoltaic (PV) Grade Si

    SciTech Connect (OSTI)

    Hovel, Harold; Prettyman, Kevin; Krause, Rainer; Dipankar, Roy

    2015-03-27

    At the beginning of this project 125 wafers of UMG material blended with non-UMG were obtained in the various blends; 50/50,70/30,80/20. 90/10 and 100% UMG. Solar grade , non-UMG material was used for comparison. Many techniques for starting substrate evaluation were used including lifetime, resitivity, SEM, IPCMS. Some degree of gettering was implemented by lengthening the time of phosphorous diffusion. The UMG/solar blends resulted in 14.5% -15% efficiencies, and even 100% UMG showed 14.5% values, not less than standard cells manufactured at the time and an encouraging result for the prospects of using UMG material due to the lower $/watt. A later decline in the cost of Si and an emphasis on reaching higher efficiencies in general led to a vanishing interest in the use of UMG.

  16. Oxygen Transport Ceramic Membranes

    SciTech Connect (OSTI)

    S. Bandopadhyay; T. Nithyanantham; X.-D Zhou; Y-W. Sin; H.U. Anderson; Alan Jacobson; C.A. Mims

    2005-05-01

    been admitted to the delivery side of the LSCrF-2828 membrane to produce the gradients which exist under syngas generation conditions. The CO-CO{sub 2} mixtures have normal isotopic {sup 18}O abundances. The evolution of {sup 18}O on the delivery side in these experiments after an {sup 18}O pulse on the air side reveals a wealth of information about the oxygen transport processes.

  17. Oxygen Transport Membranes

    SciTech Connect (OSTI)

    S. Bandopadhyay

    2008-08-30

    The focus of this research was to develop new membrane materials by synthesizing different compounds and determining their defect structures, crystallographic structures and electrical properties. In addition to measuring electrical conductivity, oxygen vacancy concentration was also evaluated using thermogravimetry, Neutron diffraction and Moessbauer Spectroscopy. The reducing conditions (CO{sub 2}/CO/H{sub 2} gas mixtures with steam) as encountered in a reactor environment can be expected to have significant influence on the mechanical properties of the oxides membranes. Various La based materials with and without Ti were selected as candidate membrane materials for OTM. The maximum electrical conductivity of LSF in air as a function of temperature was achieved at < 600 C and depends on the concentration of Sr (acceptor dopant). Oxygen occupancy in LSF was estimated using Neutron diffractometry and Moessbauer Spectroscopy by measuring magnetic moment changes depending on the Fe{sup 3+} and Fe{sup 4+} ratio. After extensive studies of candidate materials, lanthanum ferrites (LSF and LSFT) were selected as the favored materials for the oxygen transport membrane (OTM). LSF is a very good material for an OTM because of its high electronic and oxygen ionic conductivity if long term stability and mechanical strength are improved. LSFT not only exhibits p-type behavior in the high oxygen activity regime, but also has n-type conduction in reducing atmospheres. Higher concentrations of oxygen vacancies in the low oxygen activity regime may improve the performance of LSFT as an OTM. The hole concentration is related to the difference in the acceptor and donor concentration by the relation p = [Sr'{sub La}]-[Ti{sm_bullet}{sub Fe}]. The chemical formulation predicts that the hole concentration is, p = 0.8-0.45 or 0.35. Experimental measurements indicated that p is about {approx} 0.35. The activation energy of conduction is 0.2 eV which implies that LSCF conducts via the

  18. Atmospheric Pressure Plasma CVD of Amorphous Hydrogenated Silicon Carbonitride (a-SiCN:H) Films Using Triethylsilane and Nitrogen

    SciTech Connect (OSTI)

    Srinivasan Guruvenket; Steven Andrie; Mark Simon; Kyle W. Johnson; Robert A. Sailer

    2011-10-04

    Amorphous hydrogenated silicon carbonitride (a-SiCN:H) thin films are synthesized by atmospheric pressure plasma enhanced chemical vapor (AP-PECVD) deposition using the Surfx Atomflow{trademark} 250D APPJ source with triethylsilane (HSiEt{sub 3}, TES) and nitrogen as the precursor and the reactive gases, respectively. The effect of the substrate temperature (T{sub s}) on the growth characteristics and the properties of a-SiCN:H films was evaluated. The properties of the films were investigated via scanning electron microscopy (SEM), atomic force microscopy (AFM) for surface morphological analyses, Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS) for chemical and compositional analyses; spectroscopic ellipsometry for optical properties and thickness determination and nanoindentation to determine the mechanical properties of the a-SiCN:H films. Films deposited at low T{sub s} depict organic like features, while the films deposited at high T{sub s} depict ceramic like features. FTIR and XPS studies reveal that an increases in T{sub s} helps in the elimination of organic moieties and incorporation of nitrogen in the film. Films deposited at T{sub s} of 425 C have an index of refraction (n) of 1.84 and hardness (H) of 14.8 GPa. A decrease in the deposition rate between T{sub s} of 25 and 250 C and increase in deposition rate between T{sub s} of 250 and 425 C indicate that the growth of a-SiCN:H films at lower T{sub s} are surface reaction controlled, while at high temperatures film growth is mass-transport controlled. Based on the experimental results, a potential route for film growth is proposed.

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

    SciTech Connect (OSTI)

    Hiller, D. Zelenina, A.; Gutsch, S.; Zacharias, M.; Dyakov, S. A.; López-Conesa, L.; López-Vidrier, J.; Peiró, F.; Garrido, B.; Estradé, S.; Schnabel, M.; Weiss, C.; Janz, S.

    2014-05-28

    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.

  20. Quantum wells on 3C-SiC/NH-SiC heterojunctions. Calculation of spontaneous polarization and electric field strength in experiments

    SciTech Connect (OSTI)

    Sbruev, I. S.; Sbruev, S. B.

    2010-10-15

    The results of experiments with quantum wells on 3C-SiC/4H-SiC and 3C-SiC/6H-SiC heterojunctions obtained by various methods are reconsidered. Spontaneous polarizations, field strengths, and energies of local levels in quantum wells on 3C-SiC/NH-SiC heterojunctions were calculated within a unified model. The values obtained are in agreement with the results of all considered experiments. Heterojunction types are determined. Approximations for valence band offsets on heterojunctions between silicon carbide polytypes and the expression for calculating local levels in quantum wells on the 3C-SiC/NH-SiC heterojunction are presented. The spontaneous polarizations and field strengths induced by spontaneous polarization on 3C-SiC/4H-SiC and 3C-SiC/6H-SiC heterojunctions were calculated as 0.71 and 0.47 C/m{sup 2} and 0.825 and 0.55 MV/cm, respectively.

  1. Anion Exchange Membranes - Transport/Conductivity

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

    transport * Computational Modeling * MORPHOLOGYCHEMISTRY * Vibrational Spectroscopy: FTIR, Raman * Scattering: SANS, SAXS * Crystallinity WAXSXRD * Microscopy * ...

  2. Transportation Emergency Preparedness Program - Making A Difference |

    Office of Environmental Management (EM)

    Department of Energy - Making A Difference Transportation Emergency Preparedness Program - Making A Difference Overview of TEPP presented by Tom Clawson. Transportation Emergency Preparedness Program - Making A Difference (493.76 KB) More Documents & Publications Transportation Emergency Preparedness Program Exercise Overview Transportation Emergency Preparedness Program 2012 TEPP Annual Report

  3. Transportation Emergency Preparedness Program | Department of Energy

    Office of Environmental Management (EM)

    Program Transportation Emergency Preparedness Program Planning for a Shipment Campaign - Identification of Responder Needs Transportation Emergency Preparedness Program (721.32 KB) More Documents & Publications Transportation Emergency Preparedness Program - Making A Difference 2012 TEPP Annual Report Transportation Emergency Preparedness Program Exercise Overview

  4. Transportation Storage Interface | Department of Energy

    Office of Environmental Management (EM)

    Storage Interface Transportation Storage Interface Regulation of Future Extended Storage and Transportation. Transportation Storage Interface (891.2 KB) More Documents & Publications Gap Analysis to Support Extended Storage of Used Nuclear Fuel Status Update: Extended Storage and Transportation Waste Confidence Activities Related to Storage of Spent Nuclear Fuel

  5. BEST (Battery Economics for more Sustainable Transportation)

    Energy Science and Technology Software Center (OSTI)

    2009-12-31

    Computer software for the simulation of battery economics based on various transportation business models.

  6. Transportation Efficiency Resources | Department of Energy

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

    Resources Transportation Efficiency Resources Transportation efficiency reduces travel demand as measured by vehicle miles traveled (VMT). While transportation efficiency policies are often implemented under local governments, national and state programs can play supportive roles in reducing VMT. Find transportation efficiency resources below. Improving Travel Efficiency at the Local Level: An ACEEE Policy Toolkit.

  7. Transportation, Aging and Disposal Canister System Performance

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

    Specification: Revision 1 | Department of Energy Transportation, Aging and Disposal Canister System Performance Specification: Revision 1 Transportation, Aging and Disposal Canister System Performance Specification: Revision 1 This document provides specifications for selected system components of the Transportation, Aging and Disposal (TAD) canister-based system. Transportation, Aging and Disposal Canister System Performance Specification: Revision 1 (6.49 MB) More Documents &

  8. Methods of producing transportation fuel

    DOE Patents [OSTI]

    Nair, Vijay; Roes, Augustinus Wilhelmus Maria; Cherrillo, Ralph Anthony; Bauldreay, Joanna M.

    2011-12-27

    Systems, methods, and heaters for treating a subsurface formation are described herein. At least one method for producing transportation fuel is described herein. The method for producing transportation fuel may include providing formation fluid having a boiling range distribution between -5.degree. C. and 350.degree. C. from a subsurface in situ heat treatment process to a subsurface treatment facility. A liquid stream may be separated from the formation fluid. The separated liquid stream may be hydrotreated and then distilled to produce a distilled stream having a boiling range distribution between 150.degree. C. and 350.degree. C. The distilled liquid stream may be combined with one or more additives to produce transportation fuel.

  9. Subsurface Flow and Contaminant Transport

    Energy Science and Technology Software Center (OSTI)

    2000-09-19

    FACT is a transient three-dimensional, finite element code for simulating isothermal groundwater flow, moisture movement, and solute transport in variably and/or fully saturated subsurface porous media. Both single and dual-domain transport formulations are available. Transport mechanisms considered include advection, hydrodynamic dispersion, linear adsorption, mobile/immobile mass transfer and first-order degradation. A wide range of acquifier conditions and remediation systems commonly encountered in the field can be simulated. Notable boundary condition (BC) options include, a combined rechargemore » and drain BC for simulating recirculation wells, and a head dependent well BC that computes flow based on specified drawdown. The code is designed to handle highly heterogenous, multi-layer, acquifer systems in a numerically efficient manner. Subsurface structure is represented with vertically distorted rectangular brick elements in a Cartesian system. The groundwater flow equation is approximated using the Bubnov-Galerkin finite element method in conjunction with an efficient symmetric Preconditioned Conjugate Gradient (PCG) ICCG matrix solver. The solute transport equation is approximated using an upstream weighted residual finite element method designed to alleviate numerical oscillation. An efficient asymmetric PCG (ORTHOMIN) matrix solver is employed for transport. For both the flow and transport equations, element matrices are computed from either influence coefficient formulas for speed, or two point Gauss-Legendre quadrature for accuracy. Non-linear flow problems can be solved using either Newton-Ralphson linearization or Picard iteration, with under-relaxation formulas to further enhance convergence. Dynamic memory allocation is implemented using Fortran 90 constructs. FACT coding is clean and modular.« less

  10. Transparent conductor-embedding nanolens for Si solar cells

    SciTech Connect (OSTI)

    Kim, Joondong E-mail: junsin@skku.edu Kumar, Melvin David; Yun, Ju-Hyung; Kim, Hongsik; Park, Hyeong-Ho; Lee, Eunsongyi; Kim, Dong-wook; Kim, Hyunyub; Kim, Mingeon; Yi, Junsin E-mail: junsin@skku.edu; Jeong, Chaehwan E-mail: junsin@skku.edu

    2015-04-13

    We present a large-scale applicable nanolens-embedding solar cell. An electrically conductive and optically transparent indium-tin-oxide (ITO) thin film was coated on a Si substrate. After then, periodically patterned ITO nanodome-arrays were formed on the ITO film by using a nano-imprint method. This structure is effective to reduce the incident light reflection for broad wavelengths and also efficient to drive the incident photons into a light-absorbing Si substrate. There exist two electric fields. One is by a p/n junction and the other is by the light absorption into Si. We designed nanolens structures to overlap two electric fields and demonstrate highly improved solar cell performances of current and voltage values from a planar structure.

  11. Thermophysical properties of U3Si2 to 1773K

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

    White, Joshua Taylor; Nelson, Andrew Thomas; Dunwoody, John Tyler; Byler, David Darrin; Safarik, Douglas Joseph; McClellan, Kenneth James

    2015-05-08

    Use of U3Si2 in nuclear reactors requires accurate thermophysical property data to capture heat transfer within the core. Compilation of the limited previous research efforts focused on the most critical property, thermal conductivity, reveals extensive disagreement. Assessment of this data is challenged by the fact that the critical structural and chemical details of the material used to provide historic data is either absent or confirms the presence of significant impurity phases. This study was initiated to fabricate high purity U3Si2 to quantify the coefficient of thermal expansion, heat capacity, thermal diffusivity, and thermal conductivity from room temperature to 1773 K.more » Here, the datasets provided in this manuscript will facilitate more detailed fuel performance modeling to assess both current and proposed reactor designs that incorporate U3Si2.« less

  12. Joining of beta-SiC by spark plasma sintering

    SciTech Connect (OSTI)

    Grasso, Salvatore; Tatarko, Peter; Rizzo, S.; Porwal, Harshit; Hu, Chunfeng; Katoh, Yutai; Salvo, M; Reece, Michael John; Ferraris, Monica

    2014-01-01

    Spark plasma sintering (SPS) was employed to join monolithic -SiC with or without titanium as intermediate joining material. Both the localizedand rapid heating contributed to the inherent energy saving of electric current assisted joining technique. The effects of uniaxial pressure and surfacepreparation were analyzed independently with respect to the flexural strength and the morphology of the joints. In particular samples polisheddown to 1 m and joined at 1900 C for 5 min achieved the strength of the as received material. The failure occurred outside the joining interface,confirming the optimum quality of the joint. Pressure in combination with surface preparation was necessary to achieve perfect adhesion and porefree direct joining of SiC. The use of Ti foil as a joining material and pressure allowed joining of unpolished SiC.

  13. Electronic and magnetic properties of Si substituted Fe3Ge

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

    Shanavas, Kavungal Veedu; McGuire, Michael A.; Parker, David S.

    2015-09-23

    Using first principles calculations we studied the effect of Si substitution in the hexagonal Fe3Ge. We find the low temperature magnetic anisotropy in this system to be planar and originating mostly from the spin-orbit coupling in Fe-d states. Reduction of the unitcell volume reduces the in-plane magnetic anisotropy, eventually turning it positive which reorients the magnetic moments to the axial direction. We find that substituting Ge with the smaller Si ions also reduces the anisotropy, potentially enhancing the region of stability of the axial magnetization, which is beneficial for magnetic applications. Thus our experimental measurements on samples of Fe3Ge1–xSix confirmmore » these predictions and show that substitution of about 6% of the Ge with Si increases by approximately 35 K the temperature range over which anisotropy is uniaxial.« less

  14. Joining SI3N4 for Advanced Turbomachinery Applications

    SciTech Connect (OSTI)

    GLASS, S. JILL; LOEHMAN, RONALD E.; HOSKING, F. MICHAEL; STEPHENS JR., JOHN J.; VIANCO, PAUL T.; NEILSEN, MICHAEL K.; WALKER, CHARLES A.; POLLINGER, J.P.; MAHONEY, F.M.; QUILLEN, B.G.

    2000-07-01

    The main objective of this project was to develop reliable, low-cost techniques for joining silicon nitride (Si{sub 3}N{sub 4}) to itself and to metals. For Si{sub 3}N{sub 4} to be widely used in advanced turbomachinery applications, joining techniques must be developed that are reliable, cost-effective, and manufacturable. This project addressed those needs by developing and testing two Si{sub 3}N{sub 4} joining systems; oxynitride glass joining materials and high temperature braze alloys. Extensive measurements were also made of the mechanical properties and oxidation resistance of the braze materials. Finite element models were used to predict the magnitudes and positions of the stresses in the ceramic regions of ceramic-to-metal joints sleeve and butt joints, similar to the geometries used for stator assemblies.

  15. N-V{sub Si}-related center in non-irradiated 6H SiC nanostructure

    SciTech Connect (OSTI)

    Bagraev, Nikolay; Danilovskii, Eduard; Gets, Dmitrii; Klyachkin, Leonid; Malyarenko, Anna; Kalabukhova, Ekaterina; Shanina, Bella; Savchenko, Dariya

    2014-02-21

    We present the first findings of the vacancy-related centers identified by the electron spin resonance (ESR) and electrically-detected (ED) ESR method in the non-irradiated 6H-SiC nanostructure. This planar 6H-SiC nanostructure represents the ultra-narrow p-type quantum well confined by the ?-barriers heavily doped with boron on the surface of the n-type 6H-SiC (0001) wafer. The EDESR method by measuring the only magnetoresistance of the 6H SiC nanostructure under the high frequency generation from the ?-barriers appears to allow the identification of the silicon vacancy centers as well as the triplet center with spin state S=1. The same triplet center that is characterized by the larger value of the zero-field splitting constant D and anisotropic g-factor is revealed by the ESR (X-band) method. The hyperfine (hf) lines in the ESR and EDESR spectra originating from the hf interaction with the {sup 14}N nucleus allow us to attribute this triplet center to the N-V{sub Si} defect.

  16. Radiation Transport Calculations and Simulations

    SciTech Connect (OSTI)

    Fasso, Alberto; Ferrari, A.; /CERN

    2011-06-30

    This article is an introduction to the Monte Carlo method as used in particle transport. After a description at an elementary level of the mathematical basis of the method, the Boltzmann equation and its physical meaning are presented, followed by Monte Carlo integration and random sampling, and by a general description of the main aspects and components of a typical Monte Carlo particle transport code. In particular, the most common biasing techniques are described, as well as the concepts of estimator and detector. After a discussion of the different types of errors, the issue of Quality Assurance is briefly considered.

  17. The role of a LiF layer on the performance of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/Si organic-inorganic hybrid solar cells

    SciTech Connect (OSTI)

    Zhang, Yunfang; Liu, Ruiyuan; Lee, Shuit-Tong; Sun, Baoquan

    2014-02-24

    We report an ultra-thin layer of lithium fluoride (LiF) between silicon (Si) and aluminum (Al) in a Si/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) hybrid solar cell which resulted in a power conversion efficiency (PCE) of 11.09%. The insertion of a thin layer of LiF improved the contact between Si and Al, which decreased the contact resistance from 5.4 × 10{sup −1} Ω cm{sup 2} to 2.6 × 10{sup −2} Ω cm{sup 2}. Also, the electron transport from Si to Al was improved and charge carrier recombination was suppressed. As a result, the short circuit current density, the open circuit voltage, and the fill factor were all improved with the presence of the LiF layer. The solar cell with the LiF/Al bilayer as a cathode displayed a 14.45% enhancement on PCE when compared with the device using pristine Al as a cathode.

  18. Isovalent substitutes play in different ways: Effects of isovalent substitution on the thermoelectric properties of CoSi0.98B0.02

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

    Sun, Hui; Lu, Xu; Morelli, Donald T.

    2016-07-21

    Boron-added CoSi, CoSi0.98B0.02, possesses a very high thermoelectric power factor of 60 μW cm-1 K-2 at room temperature, which is among the highest power factors that have ever been reported for near-room-temperature thermoelectric applications. Since the electrical properties of this material have been tuned properly, isovalent substitution for its host atoms are intentionally employed to reduce the lattice thermal conductivity while maintaining the electronic properties unchanged. In our previous work, the effect of Rh substitution for Co atoms on the thermoelectric properties of CoSi0.98B0.02 has been studied. Here we present a study of the substitution of Ge for Si atomsmore » in this compound. Even though Ge and Rh are isovalent with their corresponding host atoms, they play different roles in determining the electrical and thermal transport properties. Through the evaluation of the lattice thermal conductivity by the Debye approximation and the comparison between the high-temperature Seebeck coefficients, we propose that Rh substitution leads to a further overlapping of the conduction and the valence bands while Ge substitution only shifts the Fermi level upward into the conduction band. Lastly, our results show that the influence of isovalent substitution on the electronic structure cannot be ignored when the alloying method is used to improve thermoelectric properties.« less

  19. On Techniques to Characterize and Correlate Grain Size, Grain Boundary Orientation and the Strength of the SiC Layer of TRISO Coated Particles: A Preliminary Study

    SciTech Connect (OSTI)

    I.J.van Rooyen; J.L. Dunzik Gougar; T. Trowbridge; Philip M van Rooyen

    2012-10-01

    The mechanical properties of the silicon carbide (SiC) layer of the TRi-ISOtropic (TRISO) coated particle (CP) for high temperature gas reactors (HTGR) are performance parameters that have not yet been standardized by the international HTR community. Presented in this paper are the results of characterizing coated particles to reveal the effect of annealing temperature (1000 to 2100C) on the strength and grain size of unirradiated coated particles. This work was further expanded to include possible relationships between the grain size and strength values. The comparative results of two strength measurement techniques and grain size measured by the Lineal intercept method are included. Preliminary grain boundary characterization results determined by electron backscatter diffraction (EBSD) are included. These results are also important for future fission product transport studies, as grain boundary diffusion is identified as a possible mechanism by which 110mAg, one of the fission activation products, might be released through intact SiC layers. Temperature is a parameter known to influence the grain size of SiC and therefore it is important to investigate the effect of high temperature annealing on the SiC grain size. Recommendations and future work will also be briefly discussed.

  20. Synthesis of SiO{sub 2}/?-SiC/graphite hybrid composite by low temperature hot filament chemical vapor deposition

    SciTech Connect (OSTI)

    Zhang, Zhikun; Bi, Kaifeng; Liu, Yanhong; Qin, Fuwen; Liu, Hongzhu; Bian, Jiming; Key Laboratory of Inorganic Coating Materials, Chinese Academy of Sciences, Shanghai 200050 ; Zhang, Dong; Miao, Lihua; Department of Computer and Mathematical Basic Teaching, Shenyang Medical College, Shenyan 110034

    2013-11-18

    ?-SiC thin films were synthesized directly on graphite by hot filament chemical vapor deposition at low temperature. SiH{sub 4} diluted in hydrogen was employed as the silicon source, while graphite was functioned as both substrate and carbon source for the as-grown ?-SiC films. X-ray diffraction and Fourier transform infrared analysis indicate that SiO{sub 2}/?-SiC/graphite hybrid composite was formed after post annealing treatment, and its crystalline quality can be remarkably improved under optimized annealing conditions. The possible growth mechanism was proposed based on in situ etching of graphite by reactive hydrogen radicals at the atomic level.

  1. Transportation Equipment (2010 MECS) | Department of Energy

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

    Transportation Equipment (2010 MECS) Transportation Equipment (2010 MECS) Manufacturing Energy and Carbon Footprint for Transportation Equipment Sector (NAICS 336) Energy use data source: 2010 EIA MECS (with adjustments) Footprint Last Revised: February 2014 View footprints for other sectors here. Manufacturing Energy and Carbon Footprint Transportation Equipment (125.57 KB) More Documents & Publications MECS 2006 - Transportation Equipment Cement (2010 MECS) Glass and Glass Products (2010

  2. Transportation System Simulation | Argonne National Laboratory

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

    Transportation System Simulation Transportation System Simulation Today's transportation systems are becoming more and more complex, with integration of communication technologies, vehicle automation and innovative mobility solutions. The advent of connected and autonomous vehicles (CAVs) will see no shortage of new technologies aimed at transforming transportation. While some will likely succeed and others fail, to truly understand their potential and their impacts on the larger transportation

  3. 2016 Sustainable Transportation Summit | Department of Energy

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

    Summit 2016 Sustainable Transportation Summit Hosted by the U.S. Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE), the first ever Sustainable Transportation Summit will bring together transportation and mobility leaders to discuss the technology, policy, and market innovations that hold the potential to shape the transportation system of the future. Sustainable Transportation, Office of Energy Efficiency and Renewable Energy, U.S. Department of Energy. When: July

  4. Recovery of Mo/Si multilayer coated optical substrates

    DOE Patents [OSTI]

    Baker, S.L.; Vernon, S.P.; Stearns, D.G.

    1997-12-16

    Mo/Si multilayers are removed from superpolished ZERODUR and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. The two step dry etching process removes SiO{sub 2} overlayer with a fluroine-containing gas and then moves molybdenum and silicon multilayers with a chlorine-containing gas. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates. 5 figs.

  5. Recovery of Mo/Si multilayer coated optical substrates

    DOE Patents [OSTI]

    Baker, Sherry L.; Vernon, Stephen P.; Stearns, Daniel G.

    1997-12-16

    Mo/Si multilayers are removed from superpolished ZERODUR and fused silica substrates with a dry etching process that, under suitable processing conditions, produces negligible change in either the substrate surface figure or surface roughness. The two step dry etching process removes SiO.sub.2 overlayer with a fluroine-containing gas and then moves molybdenum and silicon multilayers with a chlorine-containing gas. Full recovery of the initial normal incidence extreme ultra-violet (EUV) reflectance response has been demonstrated on reprocessed substrates.

  6. 15.08.07 RH Si Microwire Photoanode - JCAP

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

    A High-Performance Si Microwire Photocathode Coupled with Ni-Mo Catalyst Shaner, M. R., McKone, J. R., Gray, H. B. & Lewis, N. S. Functional integration of Ni-Mo electrocatalysts with i microwire array photocathodes to simultaneously achieve high fill factors and light-limited photocurrent densities for solar-driven hydrogen evolution. Energy & Environmental Science, DOI: 10.1039/C5EE01076D (2015). Scientific Achievement We have designed and demonstrated a H2-evolving Si microwire

  7. Heteroepitaxial Ge-on-Si by DC magnetron sputtering

    SciTech Connect (OSTI)

    Steglich, Martin; Schrempel, Frank; Fchsel, Kevin; Kley, Ernst-Bernhard; Patzig, Christian; Berthold, Lutz; Hche, Thomas; Tnnermann, Andreas; Fraunhofer Institute for Applied Optics and Precision Engineering IOF, Albert-Einstein-Str. 7, 07745 Jena

    2013-07-15

    The growth of Ge on Si(100) by DC Magnetron Sputtering at various temperatures is studied by Spectroscopic Ellipsometry and Transmission Electron Microscopy. Smooth heteroepitaxial Ge films are prepared at relatively low temperatures of 380C. Typical Stransky-Krastanov growth is observed at 410C. At lower temperatures (320C), films are essentially amorphous with isolated nanocrystallites at the Si-Ge interface. A minor oxygen contamination at the interface, developing after ex-situ oxide removal, is not seen to hinder epitaxy. Compensation of dislocation-induced acceptors in Ge by sputtering from n-doped targets is proposed.

  8. Photoluminescence from Si nanocrystals exposed to a hydrogen plasma

    SciTech Connect (OSTI)

    Jung, Yoon-Jin; Yoon, Jong-Hwan; Elliman, R. G.; Wilkinson, A. R.

    2008-10-15

    Si nanocrystals embedded in SiO{sub 2} films were exposed to an atomic H plasma at different temperatures. Photoluminescence intensity from the nanocrystals increases with increasing exposure time, followed by saturation that depends on the exposure temperature. The saturation level depends on the final exposure temperature and shows no dependence on the thermal history of exposure. This behavior is shown to be consistent with a model in which the steady-state passivation level is determined by a balance between defect passivation and depassivation by H, with the activation energy for the passivation reaction being larger than that for the depassivation reaction.

  9. Transportation of Hazardous Evidentiary Material.

    SciTech Connect (OSTI)

    Osborn, Douglas.

    2005-06-01

    This document describes the specimen and transportation containers currently available for use with hazardous and infectious materials. A detailed comparison of advantages, disadvantages, and costs of the different technologies is included. Short- and long-term recommendations are also provided.3 DraftDraftDraftExecutive SummaryThe Federal Bureau of Investigation's Hazardous Materials Response Unit currently has hazardous material transport containers for shipping 1-quart paint cans and small amounts of contaminated forensic evidence, but the containers may not be able to maintain their integrity under accident conditions or for some types of hazardous materials. This report provides guidance and recommendations on the availability of packages for the safe and secure transport of evidence consisting of or contaminated with hazardous chemicals or infectious materials. Only non-bulk containers were considered because these are appropriate for transport on small aircraft. This report will addresses packaging and transportation concerns for Hazardous Classes 3, 4, 5, 6, 8, and 9 materials. If the evidence is known or suspected of belonging to one of these Hazardous Classes, it must be packaged in accordance with the provisions of 49 CFR Part 173. The anthrax scare of several years ago, and less well publicized incidents involving unknown and uncharacterized substances, has required that suspicious substances be sent to appropriate analytical laboratories for analysis and characterization. Transportation of potentially hazardous or infectious material to an appropriate analytical laboratory requires transport containers that maintain both the biological and chemical integrity of the substance in question. As a rule, only relatively small quantities will be available for analysis. Appropriate transportation packaging is needed that will maintain the integrity of the substance, will not allow biological alteration, will not react chemically with the substance being

  10. Robust diamond-like Fe-Si network in the zero-strain NaxFeSiO4 cathode

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

    Ye, Zhuo; Zhao, Xin; Li, Shouding; Wu, Shunqing; Wu, Ping; Nguyen, Manh Cuong; Guo, Jianghuai; Mi, Jinxiao; Gong, Zhengliang; Zhu, Zi -Zhong; et al

    2016-07-14

    Sodium orthosilicates Na2MSiO4 (M denotes transition metals) have attracted much attention due to the possibility of exchanging two electrons per formula unit. In this work, we report a group of sodium iron orthosilicates Na2FeSiO4. Their crystal structures are characterized by a diamond-like Fe-Si network. The Fe-Si network is quite robust against the charge/discharge process, which explains the high structural stability observed in experiment. Furthermore, using the density functional theory within the GGA + U framework and X-ray diffraction studies, the crystal structures and structural stabilities during the sodium extraction/re-insertion process are systematically investigated.

  11. Electrofuels: Versatile Transportation Energy Solutions

    SciTech Connect (OSTI)

    2010-07-01

    Electrofuels Project: ARPA-E’s Electrofuels Project is using microorganisms to create liquid transportation fuels in a new and different way that could be up to 10 times more energy efficient than current biofuel production methods. ARPA-E is the only U.S. government agency currently funding research on Electrofuels.

  12. Lithium diffusion at Si-C interfaces in silicon-graphene composites

    SciTech Connect (OSTI)

    Odbadrakh, Khorgolkhuu [Joint Institute for Computational Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); McNutt, N. W. [Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States); Nicholson, D. M. [Computational Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Department of Physics, University of North Carolina, Asheville, North Carolina 28804 (United States); Rios, O. [Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States); Keffer, D. J. [Department of Materials Science and Engineering, University of Tennessee, Knoxville, Tennessee 37996 (United States)

    2014-08-04

    Models of intercalated Li and its diffusion in Si-Graphene interfaces are investigated using density functional theory. Results suggest that the presence of interfaces alters the energetics of Li binding and diffusion significantly compared to bare Si or Graphene surfaces. Our results show that cavities along reconstructed Si surface provide diffusion paths for Li. Diffusion barriers calculated along these cavities are significantly lower than penetration barriers to bulk Si. Interaction with Si surface results in graphene defects, creating Li diffusion paths that are confined along the cavities but have still lower barrier than in bulk Si.

  13. LDRD final report on Si nanocrystal as device prototype for spintronics applications.

    SciTech Connect (OSTI)

    Carroll, Malcolm S.; Verley, Jason C.; Pan, Wei; Banks, James Clifford; Brewer, Luke N.; Sheng, Josephine Juin-Jye; Barton, Daniel Lee; Dunn, Roberto G.

    2006-11-01

    The silicon microelectronics industry is the technological driver of modern society. The whole industry is built upon one major invention--the solid-state transistor. It has become clear that the conventional transistor technology is approaching its limitations. Recent years have seen the advent of magnetoelectronics and spintronics with combined magnetism and solid state electronics via spin-dependent transport process. In these novel devices, both charge and spin degree freedoms can be manipulated by external means. This leads to novel electronic functionalities that will greatly enhance the speed of information processing and memory storage density. The challenge lying ahead is to understand the new device physics, and control magnetic phenomena at nanometer length scales and in reduced dimensions. To meet this goal, we proposed the silicon nanocrystal system, because: (1) It is compatible with existing silicon fabrication technologies; (2) It has shown strong quantum confinement effects, which can modify the electric and optical properties through directly modifying the band structure; and (3) the spin-orbital coupling in silicon is very small, and for isotopic pure {sup 28}Si, the nuclear spin is zero. These will help to reduce the spin-decoherence channels. In the past fiscal year, we have studied the growth mechanism of silicon-nanocrystals embedded in silicon dioxide, their photoluminescence properties, and the Si-nanocrystal's magnetic properties in the presence of Mn-ion doping. Our results may demonstrate the first evidence of possible ferromagnetic orders in Mn-ion implanted silicon nanocrystals, which can lead to ultra-fast information process and ultra-dense magnetic memory applications.

  14. Light harvesting with Ge quantum dots embedded in SiO{sub 2} or Si{sub 3}N{sub 4}

    SciTech Connect (OSTI)

    Cosentino, Salvatore Raciti, Rosario; Simone, Francesca; Crupi, Isodiana; Terrasi, Antonio; Mirabella, Salvo; Sungur Ozen, Emel; Aydinli, Atilla; Mio, Antonio M.; Nicotra, Giuseppe; Turan, Rasit

    2014-01-28

    Germanium quantum dots (QDs) embedded in SiO{sub 2} or in Si{sub 3}N{sub 4} have been studied for light harvesting purposes. SiGeO or SiGeN thin films, produced by plasma enhanced chemical vapor deposition, have been annealed up to 850?C to induce Ge QD precipitation in Si based matrices. By varying the Ge content, the QD diameter can be tuned in the 39?nm range in the SiO{sub 2} matrix, or in the 12?nm range in the Si{sub 3}N{sub 4} matrix, as measured by transmission electron microscopy. Thus, Si{sub 3}N{sub 4} matrix hosts Ge QDs at higher density and more closely spaced than SiO{sub 2} matrix. Raman spectroscopy revealed a higher threshold for amorphous-to-crystalline transition for Ge QDs embedded in Si{sub 3}N{sub 4} matrix in comparison with those in the SiO{sub 2} host. Light absorption by Ge QDs is shown to be more effective in Si{sub 3}N{sub 4} matrix, due to the optical bandgap (0.91.6?eV) being lower than in SiO{sub 2} matrix (1.22.2?eV). Significant photoresponse with a large measured internal quantum efficiency has been observed for Ge QDs in Si{sub 3}N{sub 4} matrix when they are used as a sensitive layer in a photodetector device. These data will be presented and discussed, opening new routes for application of Ge QDs in light harvesting devices.

  15. Transportation and packaging resource guide

    SciTech Connect (OSTI)

    Arendt, J.W.; Gove, R.M.; Welch, M.J.

    1994-12-01

    The purpose of this resource guide is to provide a convenient reference document of information that may be useful to the U.S. Department of Energy (DOE) and DOE contractor personnel involved in packaging and transportation activities. An attempt has been made to present the terminology of DOE community usage as it currently exists. DOE`s mission is changing with emphasis on environmental cleanup. The terminology or nomenclature that has resulted from this expanded mission is included for the packaging and transportation user for reference purposes. Older terms still in use during the transition have been maintained. The Packaging and Transportation Resource Guide consists of four sections: Sect. 1, Introduction; Sect. 2, Abbreviations and Acronyms; Sect. 3, Definitions; and Sect. 4, References for packaging and transportation of hazardous materials and related activities, and Appendices A and B. Information has been collected from DOE Orders and DOE documents; U.S Department of Transportation (DOT), U.S. Environmental Protection Agency (EPA), and U.S. Nuclear Regulatory Commission (NRC) regulations; and International Atomic Energy Agency (IAEA) standards and other international documents. The definitions included in this guide may not always be a regulatory definition but are the more common DOE usage. In addition, the definitions vary among regulatory agencies. It is, therefore, suggested that if a definition is to be used in a regulatory or a legal compliance issue, the definition should be verified with the appropriate regulation. To assist in locating definitions in the regulations, a listing of all definition sections in the regulations are included in Appendix B. In many instances, the appropriate regulatory reference is indicated in the right-hand margin.

  16. Charge noise analysis of metal oxide semiconductor dual-gate Si/SiGe quantum point contacts

    SciTech Connect (OSTI)

    Kamioka, J.; Oda, S.; Kodera, T.; Takeda, K.; Obata, T.; Tarucha, S.

    2014-05-28

    The frequency dependence of conductance noise through a gate-defined quantum point contact fabricated on a Si/SiGe modulation doped wafer is characterized. The 1/f{sup 2} noise, which is characteristic of random telegraph noise, is reduced by application of a negative bias on the global top gate to reduce the local gate voltage. Direct leakage from the large global gate voltage also causes random telegraph noise, and therefore, there is a suitable point to operate quantum dot measurement.

  17. X-ray nanotomography of SiO{sub 2}-coated Pt{sub 90}Ir{sub 10} tips with sub-micron conducting apex

    SciTech Connect (OSTI)

    Rose, V.; Chien, T. Y.; Hiller, J.; Rosenmann, D.; Winarski, R. P.

    2011-10-24

    Hard x-ray nanotomography provides an important three-dimensional view of insulator-coated ''smart tips'' that can be utilized for modern emerging scanning probe techniques. Tips, entirely coated by an insulating SiO{sub 2} film except at the very tip apex, are fabricated by means of electron beam physical vapor deposition, focused ion beam milling and ion beam-stimulated oxide growth. Although x-ray tomography studies confirm the structural integrity of the oxide film, transport measurements suggest the presence of defect-induced states in the SiO{sub 2} film. The development of insulator-coated tips can facilitate nanoscale analysis with electronic, chemical, and magnetic contrast by synchrotron-based scanning probe microscopy.

  18. Local structure order in Pd??Cu?Si?? liquid

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

    Yue, G. Q.; Iowa State Univ., Ames, IA; Zhang, Y.; Sun, Y.; Shen, B.; Dong, F.; Wang, Z. Y.; Zhang, R. J.; Zheng, Y. X.; Kramer, M. J.; et al

    2015-02-05

    The short-range order (SRO) in Pd??Cu?Si?? liquid was studied by high energy x-ray diffraction and ab initio molecular dynamics (MD) simulations. The calculated pair correlation functions at different temperatures agree well with the experimental results. The partial pair correlation functions from ab intio MD simulations indicate that Si atoms prefer to be uniformly distributed while Cu atoms tend to aggregate. By performing structure analysis using Honeycutt-Andersen index, Voronoi tessellation, and atomic cluster alignment method, we show that the icosahedron and face-centered cubic SRO increase upon cooling. The dominant SRO is the Pd-centered Pd?Si? motif, namely the structure of which motifmoreis similar to the structure of Pd-centered clusters in the Pd?Si? crystal. The study further confirms the existence of trigonal prism capped with three half-octahedra that is reported as a structural unit in Pd-based amorphous alloys. The majority of Cu-centered clusters are icosahedra, suggesting that the presence of Cu is benefit to promote the glass forming ability.less

  19. Electrical properties of ternary Si-C-N ceramics

    SciTech Connect (OSTI)

    Haluschka, C.; Engel, C.; Riedel, R.

    1996-12-31

    Ternary Si-C-N ceramics were derived from silicon containing polymers by thermally induced hybrid processing. These silicon carbonitrides were investigated by impedance spectroscopy depending on the synthesis conditions. The electrical behavior correlates with the solid state reactions and phase transformations, which take place during the processing. It has also been shown that the electrical properties can be controlled in a wide range.

  20. Towards SiC Surface Functionalization: An Ab Initio Study

    SciTech Connect (OSTI)

    Cicero, G; Catellani, A

    2005-01-28

    We present a microscopic model of the interaction and adsorption mechanism of simple organic molecules on SiC surfaces as obtained from ab initio molecular dynamics simulations. Our results open the way to functionalization of silicon carbide, a leading candidate material for bio-compatible devices.

  1. Synthesis and Characterization of Structured Si-Carbon Nanocomposite Anodes

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

    and Functional Polymer Binders | Department of Energy 7_wang_2012_p.pdf (2.21 MB) More Documents & Publications Novel Lithium Ion Anode Structures: Overview of New DOE BATT Anode Projects Synthesis and Characterization of Structured Si-Carbon Nanocomposite Anodes and Functional Polymer Binders Development of High Capacity Anode for Li-ion Batteries

  2. Elastic scattering of /sup 16/O by /sup 28/Si

    SciTech Connect (OSTI)

    Shkolnik, V.; Dehnhard, D.; Franey, M.A.

    1983-08-01

    Differential cross sections were measured in small angular steps at forward angles for the elastic scattering of /sup 16/O from /sup 28/Si, /sup 29/Si, and /sup 30/Si at E/sub lab/ = 60 MeV and from /sup 28/Si at six other incident energies between 45 and 63 MeV. The angular position of a peak in the diffraction pattern at theta/sub c.m./approx. =75/sup 0/ was measured as a function of the incident energy between 55 and 63 MeV in 0.5 MeV steps. Close fits to these angular distributions and those of other authors at energies between 41 and 81 MeV, some spanning the whole angular range up to 180/sup 0/, and the excitation functions at 90/sup 0/ and 180/sup 0/, were obtained in an optical model analysis. A consistent description of the data was found by the use of a surface-transparent and parity-dependent potential with a real part able to generate a pocket in the total potential. The real and imaginary strengths depend quite strongly and smoothly on the incident energy. This potential shows a transition from surface transparency to strong absorption as E/sub lab/ approaches 81 MeV. The ambiguities in the strengths of the potential are discussed. The broad dispersive potential resonances which are present in several partial waves at every energy are also discussed and their relative importance is examined.

  3. Combined wet and dry cleaning of SiGe(001)

    SciTech Connect (OSTI)

    Park, Sang Wook; Kaufman-Osborn, Tobin; Kim, Hyonwoong; Siddiqui, Shariq; Sahu, Bhagawan; Yoshida, Naomi; Brandt, Adam; Kummel, Andrew C.

    2015-07-15

    Combined wet and dry cleaning via hydrofluoric acid (HF) and atomic hydrogen on Si{sub 0.6}Ge{sub 0.4}(001) surface was studied at the atomic level using ultrahigh vacuum scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and x-ray photoelectron spectroscopy to understand the chemical transformations of the surface. Aqueous HF removes native oxide, but residual carbon and oxygen are still observed on Si{sub 0.6}Ge{sub 0.4}(001) due to hydrocarbon contamination from post HF exposure to ambient. The oxygen contamination can be eliminated by shielding the sample from ambient via covering the sample in the HF cleaning solution until the sample is introduced to the vacuum chamber or by transferring the sample in an inert environment; however, both processes still leave carbon contaminant. Dry in-situ atomic hydrogen cleaning above 330 °C removes the carbon contamination on the surface consistent with a thermally activated atomic hydrogen reaction with surface hydrocarbon. A postdeposition anneal at 550 °C induces formation of an atomically flat and ordered SiGe surface observed by STM. STS verifies that the wet and dry cleaned surface has an unpinned Fermi level with no states between the conduction and valence band edge comparable to sputter cleaned SiGe surfaces.

  4. NREL: Transportation Research - Successful Transportation Lab-Industry

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

    Collaborations Spotlighted at Summit Successful Transportation Lab-Industry Collaborations Spotlighted at Summit Five men stand outside in front of passenger car and white modular building. On display at the National Lab Impact Summit, a Toyota Mirai fuel cell electric vehicle from NREL paired with a 3D-printed building from ORNL can work together to produce and store renewable energy. Image Dennis Schroeder, NREL. May 18, 2016 On May 4, NREL hosted leaders from the business, government, and

  5. Long-term stable water vapor permeation barrier properties of SiN/SiCN/SiN nanolaminated multilayers grown by plasma-enhanced chemical vapor deposition at extremely low pressures

    SciTech Connect (OSTI)

    Choi, Bum Ho Lee, Jong Ho

    2014-08-04

    We investigated the water vapor permeation barrier properties of 30-nm-thick SiN/SiCN/SiN nanolaminated multilayer structures grown by plasma enhanced chemical vapor deposition at 7 mTorr. The derived water vapor transmission rate was 1.12 × 10{sup −6} g/(m{sup 2} day) at 85 °C and 85% relative humidity, and this value was maintained up to 15 000 h of aging time. The X-ray diffraction patterns revealed that the nanolaminated film was composed of an amorphous phase. A mixed phase was observed upon performing high resolution transmission electron microscope analysis, which indicated that a thermodynamically stable structure was formed. It was revealed amorphous SiN/SiCN/SiN multilayer structures that are free from intermixed interface defects effectively block water vapor permeation into active layer.

  6. Drift-Scale Radionuclide Transport

    SciTech Connect (OSTI)

    P.R. Dixon

    2004-02-17

    The purpose of this Model Report is to document two models for drift-scale radionuclide transport. This has been developed in accordance with ''Technical Work Plan for: Performance Assessment Unsaturated Zone'' (Bechtel SAIC Company, LLC (BSC) 2002 [160819]), which includes planning documents for the technical work scope, content, and management of this Model Report in Section 1.15, Work Package AUZM11, ''Drift-Scale Radionuclide Transport.'' The technical work scope for this Model Report calls for development of a process-level model and an abstraction model representing diffusive release from the invert to the rocks, partitioned between fracture and matrix, as compared to the fracture-release approach used in the Site Recommendation. The invert is the structure constructed in a drift to provide the floor of that drift. The plan for validation of the models documented in this Model Report is given in Section I-5 of Attachment I in BSC (2002 [160819]). Note that the model validation presented in Section 7 deviates from the technical work plan (BSC 2002 [160819], Section I-5) in that an independent technical review specifically for model validation has not been conducted, nor publication in a peer-reviewed journal. Model validation presented in Section 7 is based on corroboration with alternative mathematical models, which is also called out by the technical work plan (BSC 2002 [160819], Section I-5), and is sufficient based on the requirements of AP-SIII.10Q for model validation. See Section 7 for additional discussion. The phenomenon of flow and transport in the vicinity of the waste emplacement drift are evaluated in this model report under ambient thermal, chemical, and mechanical conditions. This includes the effects of water diversion around an emplacement drift and the flow and transport behavior expected in a fractured rock below the drift. The reason for a separate assessment of drift-scale transport is that the effects of waste emplacement drifts on flow

  7. Resorption Rate Tunable Bioceramic: Si, Zn-Modified Tricalcium Phosphate

    SciTech Connect (OSTI)

    Xiang Wei

    2006-08-09

    This dissertation is organized in an alternate format. Several manuscripts which have already been published or are to be submitted for publication have been included as separate chapters. Chapter 1 is a general introduction which describes the dissertation organization and introduces the human bone and ceramic materials as bone substitute. Chapter 2 is the background and literature review on dissolution behavior of calcium phosphate, and discussion of motivation for this research. Chapter 3 is a manuscript entitled ''Si,Zn-modified tricalcium phosphate: a phase composition and crystal structure study'', which was published in ''Key Engineering Materials'' [1]. Chapter 4 gives more crystal structure details by neutron powder diffraction, which identifies the position for Si and Zn substitution and explains the stabilization mechanism of the structure. A manuscript entitled ''Crystal structure analysis of Si, Zn-modified Tricalcium phosphate by Neutron Powder Diffraction'' will be submitted to Biomaterials [2]. Chapter 5 is a manuscript, entitled ''Dissolution behavior and cytotoxicity test of Si, Zn-modified tricalcium phosphate'', which is to be submitted to Biomaterials [3]. This paper discusses the additives effect on the dissolution behavior of TCP, and cytotoxicity test result is also included. Chapter 6 is the study of hydrolysis process of {alpha}-tricalcium phosphate in the simulated body fluid, and the phase development during drying process is discussed. A manuscript entitled ''Hydrolysis of {alpha}-tricalcium phosphate in simulated body fluid and phase transformation during drying process'' is to be submitted to Biomaterials [4]. Ozan Ugurlu is included as co-authors in these two papers due to his TEM contributions. Appendix A is the general introduction of the materials synthesis, crystal structure and preliminary dissolution result. A manuscript entitled ''Resorption rate tunable bioceramic: Si and Zn-modified tricalcium phosphate'' was published in

  8. Transportation

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

    ... Another off-site shuttle provides express service to and from the Rockridge BART station ... All riders are required to show ID when boarding off-site buses. Acceptable ID's are: LBNL ...

  9. Research on the Hydrogen Passivation of Defects and Impurities in Si Relevant to Crystalline Si Solar Cell Materials: Final Report, 16 February 2000 -- 15 April 2003

    SciTech Connect (OSTI)

    Stavola, M.

    2003-09-01

    The goal of this experimental research program is to increase the understanding, at a microscopic level, of hydrogenation processes and passivation mechanisms for crystalline-Si photovoltaics. In our experiments, vibrational spectroscopy was used to study the properties of the interstitial H2 molecule in Si and the transition-metal-hydrogen complexes in Si. The interstitial H2 molecule is formed readily in Si when hydrogen is introduced. Our studies establish that interstitial H2 in Si behaves as a nearly free rotator, solving puzzles about the behavior of this defect that have persisted since the discovery of its vibrational spectrum. The transition metals are common impurities in Si that decrease the minority-carrier lifetime and degrade the efficiencies of solar cells. Therefore, the possibility that transition-metal impurities in Si might be passivated by hydrogen has long been of interest. Our studies of transition-metal-H complexes in Si help to establish the structural and electrical properties of a family of Pt-H complexes in Si, and have made the Pt-H complexes a model system for understanding the interaction of hydrogen with transition-metal impurities in Si.

  10. Comparative life-cycle energy payback analysis of multi-junction a-SiGe and nanocrystalline/a-Si modules

    SciTech Connect (OSTI)

    Fthenakis, V.; Kim, H.

    2010-07-15

    Despite the publicity of nanotechnologies in high tech industries including the photovoltaic sector, their life-cycle energy use and related environmental impacts are understood only to a limited degree as their production is mostly immature. We investigated the life-cycle energy implications of amorphous silicon (a-Si) PV designs using a nanocrystalline silicon (nc-Si) bottom layer in the context of a comparative, prospective life-cycle analysis framework. Three R and D options using nc-Si bottom layer were evaluated and compared to the current triple-junction a-Si design, i.e., a-Si/a-SiGe/a-SiGe. The life-cycle energy demand to deposit nc-Si was estimated from parametric analyses of film thickness, deposition rate, precursor gas usage, and power for generating gas plasma. We found that extended deposition time and increased gas usages associated to the relatively high thickness of nc-Si lead to a larger primary energy demand for the nc-Si bottom layer designs, than the current triple-junction a-Si. Assuming an 8% conversion efficiency, the energy payback time of those R and D designs will be 0.7-0.9 years, close to that of currently commercial triple-junction a-Si design, 0.8 years. Future scenario analyses show that if nc-Si film is deposited at a higher rate (i.e., 2-3 nm/s), and at the same time the conversion efficiency reaches 10%, the energy-payback time could drop by 30%.

  11. Formation of quantum spin Hall state on Si surface and energy...

    Office of Scientific and Technical Information (OSTI)

    Si surface and energy gap scaling with strength of spin orbit coupling Title: Formation of quantum spin Hall state on Si surface and energy gap scaling with strength of spin orbit ...

  12. Chemical reactivity of CVC and CVD SiC with UO2 at high temperatures

    SciTech Connect (OSTI)

    Silva, Chinthaka M; Katoh, Yutai; Voit, Stewart L; Snead, Lance Lewis

    2015-01-01

    Two types of silicon carbide (SiC) synthesized using two different vapor deposition processes were embedded in UO2 pellets and evaluated for their potential chemical reaction with UO2. While minor reactivity between chemical-vapor-composited (CVC) SiC and UO2 was observed at comparatively low temperatures of 1100 and 1300 C, chemical-vapor-deposited (CVD) SiC did not show any such reactivity, according to microstructural investigations. However, both CVD and CVC SiCs showed some reaction with UO2 at a higher temperature (1500 C). Elemental maps supported by phase maps obtained using electron backscatter diffraction indicated that CVC SiC was more reactive than CVD SiC at 1500 C. Furthermore, this investigation indicated the formation of uranium carbides and uranium silicide chemical phases such as UC, USi2, and U3Si2 as a result of SiC reaction with UO2.

  13. PID Failure of c-Si and Thin-Film Modules and Possible Correlation...

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

    PID Failure of c-Si and Thin-Film Modules and Possible Correlation with Leakage Currents PID Failure of c-Si and Thin-Film Modules and Possible Correlation with Leakage Currents ...

  14. Investigation of the physical properties of the tetragonal CeMAl4Si2...

    Office of Scientific and Technical Information (OSTI)

    the tetragonal CeMAl4Si2 (M Rh, Ir, Pt) compounds Prev Next Title: Investigation of the physical properties of the tetragonal CeMAl4Si2 (M Rh, Ir, Pt) compounds The ...

  15. Valence electronenergy-lossspectroscopystudyofZrSiO4 and ZrO2...

    Office of Scientific and Technical Information (OSTI)

    electronenergy-lossspectroscopystudyofZrSiO4 and ZrO2 ZrSiO4 (zircon) and m-ZrO2 (zirconia) are fundamental and industrially important materials.This work reports the detailed...

  16. Sensitivities of I-V Parameters in C-Si PV Modules of Hygrothermal...

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

    Sensitivities of I-V Parameters in C-Si PV Modules of Hygrothermal Stress Sensitivities of I-V Parameters in C-Si PV Modules of Hygrothermal Stress Presented at the PV Module ...

  17. Fuel Consumption and NOx Trade-offs on a Port-Fuel-Injected SI...

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

    Consumption and NOx Trade-offs on a Port-Fuel-Injected SI Gasoline Engine Equipped with a Lean-NOx Trap Fuel Consumption and NOx Trade-offs on a Port-Fuel-Injected SI Gasoline ...

  18. Single-Step Non-Thermal Plasma Synthesis of 3C-SiC Nanoparticles...

    Office of Scientific and Technical Information (OSTI)

    Single-Step Non-Thermal Plasma Synthesis of 3C-SiC Nanoparticles Citation Details In-Document Search Title: Single-Step Non-Thermal Plasma Synthesis of 3C-SiC Nanoparticles ...

  19. Development of Solar Grade Silicon (SoG-Si) Feedstock by Recycling SoG-Si Wastes

    SciTech Connect (OSTI)

    Lifeng Zhang; Anping Dong; Lucas Nana Wiredu Damoah

    2013-01-24

    Experiment results of EM separation show that the non-metallic inclusions were successfully pushed to the boundary layer of the crucible under EM force. Larger frequency and smaller current generate smaller thickness of accumulated inclusions. More detailed EM separation experiments are undergoing to investigate the factors that affect the removal efficient of inclusions from SoG-Si

  20. Ag Out-surface Diffusion In Crystalline SiC With An Effective SiO2 Diffusion Barrier

    SciTech Connect (OSTI)

    Xue, H.; Xiao, Haiyan Y.; Zhu, Zihua; Shutthanandan, V.; Snead, Lance L.; Boatner, Lynn A.; Weber, William J.; Zhang, Y.

    2015-09-01

    For applications of tristructural isotropic (TRISO) fuel particles in high temperature reactors, release of radioactive Ag isotope (110mAg) through the SiC coating layer is a safety concern. To understand the diffusion mechanism, Ag ion implantations near the surface and in the bulk were performed by utilizing different ion energies and energy-degrader foils. High temperature annealing was carried out on the as-irradiated samples to study the possible out-surface diffusion. Before and after annealing, Rutherford backscattering spectrometry (RBS) and secondary ion mass spectrometry (SIMS) measurements were employed to obtain the elemental profiles of the implanted samples. The results suggest little migration of buried Ag in the bulk, and an out-diffusion of the implanted Ag in the near-surface region of single crystal SiC. It is also found that a SiO2 layer, which was formed during annealing, may serve as an effective barrier to reduce or prevent Ag out diffusion through the SiC coating layer.