National Library of Energy BETA

Sample records for three-junction concentrator cells

  1. Three-junction solar cell

    DOE Patents [OSTI]

    Ludowise, Michael J. (Cupertino, CA)

    1986-01-01

    A photovoltaic solar cell is formed in a monolithic semiconductor. The cell contains three junctions. In sequence from the light-entering face, the junctions have a high, a medium, and a low energy gap. The lower junctions are connected in series by one or more metallic members connecting the top of the lower junction through apertures to the bottom of the middle junction. The upper junction is connected in voltage opposition to the lower and middle junctions by second metallic electrodes deposited in holes 60 through the upper junction. The second electrodes are connected to an external terminal.

  2. Three-junction solar cells comprised of a thin-film GaInP/GaAs tandem cell mechanically stacked on a Si cell

    SciTech Connect (OSTI)

    Yazawa, Y.; Tamura, K.; Watahiki, S.; Kitatani, T.; Ohtsuka, H.; Warabisako, T.

    1997-12-31

    Three-junction tandem solar cells were fabricated by mechanical stacking of a thin-film GaInP/GaAs monolithic tandem cell and a Si cell. The epitaxial lift-off (ELO) technique was used for the thinning of GaInP/GaAs tandem cells. Both spectral responses of the GaInP top cell and the GaAs middle cell in the thin-film GaInP/GaAs monolithic tandem cell were conserved. The Si cell performance has been improved by reducing the absorption loss in the GaAs substrate.

  3. Light-trapping concentrator cells

    SciTech Connect (OSTI)

    Keavney, C.J.; Geoffroy, L.M.; Sanfacon, M.M.; Tobin, S.P. (Spire Corp., Bedford, MA (USA))

    1989-11-01

    The objective of this project was to develop a thin, light-trapping silicon concentrator solar cell using a new structure, the cross-grooved cell. A process was developed for fabricating V-grooves on both sides of thin silicon wafers, the grooves on one side being perpendicular to those on the other side. A novel way of minimizing flat spots at the tops of the V-grooves was discovered. We experimentally verified the theoretical light-trapping superiority of the cross-grooved structure. We also demonstrated a reduction in grid line obscuration for grid lines running parallel to the V-grooves due to light reflection into the cell. high short-circuit current densities were achieved for p-i-n concentrator cells with the cross-grooved structure, proving the concept. The best efficiencies achieved were 18% at concentration, compared to 20% for a conventional planar low-resistivity cell. Recombination in the full-area emitter was identified as the major intrinsic loss mechanism in these thin, high-resistivity bifacial cells. Recombination on the emitter limits Voc and fill factor, and also leads to a large sublinearity of short-circuit current with light intensity. Reduction of the junction area is a major recommendation for future work. In addition, there were persistent problems with ohmic contacts and maintaining high minority-carrier lifetime during processing. We believe that these problems can be solved, and that the cross-grooved cell is a viable approach to the limit-efficiency silicon solar cell. This report covers research conducted between March 1987 and July 1989. 22 refs., 40 figs., 24 tabs.

  4. Gas concentration cells for utilizing energy

    DOE Patents [OSTI]

    Salomon, Robert E. (Philadelphia, PA)

    1987-01-01

    An apparatus and method for utilizing energy, in which the apparatus may be used for generating electricity or as a heat pump. When used as an electrical generator, two gas concentration cells are connected in a closed gas circuit. The first gas concentration cell is heated and generates electricity. The second gas concentration cell repressurizes the gas which travels between the cells. The electrical energy which is generated by the first cell drives the second cell as well as an electrical load. When used as a heat pump, two gas concentration cells are connected in a closed gas circuit. The first cell is supplied with electrical energy from a direct current source and releases heat. The second cell absorbs heat. The apparatus has no moving parts and thus approximates a heat engine.

  5. Gas concentration cells for utilizing energy

    DOE Patents [OSTI]

    Salomon, R.E.

    1987-06-30

    An apparatus and method are disclosed for utilizing energy, in which the apparatus may be used for generating electricity or as a heat pump. When used as an electrical generator, two gas concentration cells are connected in a closed gas circuit. The first gas concentration cell is heated and generates electricity. The second gas concentration cell repressurizes the gas which travels between the cells. The electrical energy which is generated by the first cell drives the second cell as well as an electrical load. When used as a heat pump, two gas concentration cells are connected in a closed gas circuit. The first cell is supplied with electrical energy from a direct current source and releases heat. The second cell absorbs heat. The apparatus has no moving parts and thus approximates a heat engine. 4 figs.

  6. Thermal regeneration of an electrochemical concentration cell

    DOE Patents [OSTI]

    Krumpelt, M.; Bates, J.K.

    1980-05-09

    A system and method are described for thermally regenerating an electrochemical concentration cell having first and second aluminum electrodes respectively positioned in contact with first and second electrolytes separated by an ion exchange member, the first and second electrolytes being composed of different concentrations of an ionic solvent and a salt, preferably an aluminum halide. The ionic solvent may be either organic or inorganic with a relatively low melting point, the ionic solvent and the salt form a complex wherein the free energy of formation of said complex is less than about -5 kcal/mole. A distillation column using solar heat or low grade industrial waste heat receives the first and second electrolytes and thermally decomposes the salt-solvent complex to provide feed material for the two half cells.

  7. Thermal regeneration of an electrochemical concentration cell

    DOE Patents [OSTI]

    Krumpelt, Michael (Naperville, IL); Bates, John K. (Plainfield, IL)

    1981-01-01

    A system and method for thermally regenerating an electrochemical concentration cell having first and second aluminum electrodes respectively positioned in contact with first and second electrolytes separated by an ion exchange member, the first and second electrolytes being composed of different concentrations of an ionic solvent and a salt, preferably an aluminum halide. The ionic solvent may be either organic or inorganic with a relatively low melting point, the ionic solvent and the salt form a complex wherein the free energy of formation of said complex is less than about -5 Kcal/mole. A distillation column using solar heat or low grade industrial waste heat receives the first and second electrolytes and thermally decomposes the salt-solvent complex to provide feed material for the two half cells.

  8. Procedures at NREL for Evaluating Multijunction Concentrator Cells

    SciTech Connect (OSTI)

    Moriarty, T.; Emery, K.

    2000-01-01

    The procedures for evaluating the performance of multijunctiion-concentrator cells at the National Renewable Energy Laboratory are described. The accurate measurement of the performance of multijunction cells requires accurate relative-quantum-efficiency-measurements, "matched" reference cells, and a spectrally adjustable solar simulator.

  9. New GaInP/GaAs/GaInAs, Triple-Bandgap, Tandem Solar Cell for High-Efficiency Terrestrial Concentrator Systems

    SciTech Connect (OSTI)

    Kurtz, S.; Wanlass, M.; Kramer, C.; Young, M.; Geisz, J.; Ward, S.; Duda, A.; Moriarty, T.; Carapella, J.; Ahrenkiel, P.; Emery. K.; Jones, K.; Romero, M.; Kibbler, A.; Olson, J.; Friedman, D.; McMahon, W.; Ptak, A.

    2005-11-01

    GaInP/GaAs/GaInAs three-junction cells are grown in an inverted configuration on GaAs, allowing high quality growth of the lattice matched GaInP and GaAs layers before a grade is used for the 1-eV GaInAs layer. Using this approach an efficiency of 37.9% was demonstrated.

  10. Point-focus spectral splitting solar concentrator for multiple cells concentrating photovoltaic system

    E-Print Network [OSTI]

    Maragliano, Carlo; Stefancich, Marco

    2015-01-01

    In this paper we present and experimentally validate a low-cost design of a spectral splitting concentrator for the efficient conversion of solar energy. The optical device consists of a dispersive prismatic lens made of polycarbonate designed to simultaneously concentrate the solar light and split it into its spectral components. With respect to our previous implementation, this device concentrates the light along two axes and generates a light pattern compatible with the dimensions of a set of concentrating photovoltaic cells while providing a higher concentration ratio. The mathematical framework and the constructive approach used for the design are presented and the device performance is simulated using ray-tracing software. We obtain spectral separation in the visible range within a 3x1 cm2 area and a maximum concentration of 210x for a single wavelength. The device is fabricated by injection molding and its performance is experimentally investigated. We measure an optical transmissivity above 90% in the...

  11. Intra-Fuel Cell Stack Measurements of Transient Concentration Distributions

    SciTech Connect (OSTI)

    Partridge Jr, William P; Toops, Todd J; Green Jr, Johney Boyd; Armstrong, Timothy R.

    2006-01-01

    Intra-fuel-cell measurements are required to understand detailed fuel-cell chemistry and physics, validate models, optimize system design and control, and realize enhanced efficiency regimes; in comparison, conventional integrated fuel-cell supply and effluent measurements are fundamentally limited in value. Intra-reactor measurements are needed for all fuel cell types. This paper demonstrates the ability of a capillary-inlet mass spectrometer to resolve transient species distributions within operating polymer-electrolyte-membrane (PEM) fuel cells and at temperatures typical of solid-oxide fuel cells (SOFC). This is the first such demonstration of a diagnostic that is sufficiently minimally invasive as to allow measurements throughout an operating fuel cell stack. Measurements of transient water, hydrogen, oxygen and diluent concentration dynamics associated with fuel-cell load switching suggest oxygen-limited chemistry. Intra-PEM fuel cell measurements of oxygen distribution at various fuel-cell loads are used to demonstrate concentration gradients, non-uniformities, and anomalous fuel cell operation.

  12. PV Cell and Module Calibrations at NREL

    SciTech Connect (OSTI)

    Emery, Keith

    2012-10-22

    NREL has equipment to measure any conceivable cell or module technology. The lack of standards for low concentration modules complicates matters. Spectrally adjustable simulators are critical for more than three junctions. NREL's 10-channel fiber optic simulator has shown that the light can be set for each junction within 1% of what it would be under the reference spectrum for up to a five-junction cell. Uncertainty in module simulators dominated by spatial nonuniformity for calibration labs. Manufacturers can mitigate this error by using matched reference modules instead of cells.

  13. Performance modeling and cell design for high concentration methanol fuel cells

    E-Print Network [OSTI]

    Chapter 50 Performance modeling and cell design for high concentration methanol fuel cells C. E The direct methanol fuel cell (DMFC) has become a lead- ing contender to replace the lithium-ion (Li density of liquid methanol (CH3OH) fuel is 4800 Wh l-1 , whereas the theoretical energy density of Li

  14. Continued development of metallization for GaAs concentrator cells

    SciTech Connect (OSTI)

    Tobin, S.P.

    1988-11-01

    The objective of this work was the integration of thermally stable metallizations with a high-efficiency GaAs concentrator cell process. For p-GaAs we used a Pt-TiN-Au metallization developed under a previous Sandia Contract. For n-GaAs the best results were obtained for AuGe-TiN-Au. Baseline p/n cells with a CrAu metallization achieved efficiencies of 25.4% at 200 suns. Efficiencies were about 22% at one sun. At one sun, p/n cells with high-temperature contacts were 22.2% efficient, showing that there is no efficiency penalty with the high-temperature metallization. Development efforts on n/p cells yielded high short-circuit currents and open-circuit voltages, with both conventional and high-temperature metallizations. Thermal annealing tests showed that cells with the Pt-TiN-Au metallization were more stable than those with the baseline metallization, withstanding a 15-minute anneal at 500/degree/C with negligible efficiency degradation. 22 refs., 64 figs., 54 tabs.

  15. Electrorefining cell with parallel electrode/concentric cylinder cathode

    DOE Patents [OSTI]

    Gay, Eddie C. (Park Forest, IL); Miller, William E. (Naperville, IL); Laidler, James J. (Burr Ridge, IL)

    1997-01-01

    A cathode-anode arrangement for use in an electrolytic cell is adapted for electrochemically refining spent nuclear fuel from a nuclear reactor and recovering purified uranium for further treatment and possible recycling as a fresh blanket or core fuel in a nuclear reactor. The arrangement includes a plurality of inner anodic dissolution baskets that are each attached to a respective support rod, are submerged in a molten lithium halide salt, and are rotationally displaced. An inner hollow cylindrical-shaped cathode is concentrically disposed about the inner anodic dissolution baskets. Concentrically disposed about the inner cathode in a spaced manner are a plurality of outer anodic dissolution baskets, while an outer hollow cylindrical-shaped is disposed about the outer anodic dissolution baskets. Uranium is transported from the anode baskets and deposited in a uniform cylindrical shape on the inner and outer cathode cylinders by rotating the anode baskets within the molten lithium halide salt. Scrapers located on each anode basket abrade and remove the spent fuel deposits on the surfaces of the inner and outer cathode cylinders, with the spent fuel falling to the bottom of the cell for removal. Cell resistance is reduced and uranium deposition rate enhanced by increasing the electrode area and reducing the anode-cathode spacing. Collection efficiency is enhanced by trapping and recovery of uranium dendrites scrapped off of the cylindrical cathodes which may be greater in number than two.

  16. Electrorefining cell with parallel electrode/concentric cylinder cathode

    DOE Patents [OSTI]

    Gay, E.C.; Miller, W.E.; Laidler, J.J.

    1997-07-22

    A cathode-anode arrangement for use in an electrolytic cell is adapted for electrochemically refining spent nuclear fuel from a nuclear reactor and recovering purified uranium for further treatment and possible recycling as a fresh blanket or core fuel in a nuclear reactor. The arrangement includes a plurality of inner anodic dissolution baskets that are each attached to a respective support rod, are submerged in a molten lithium halide salt, and are rotationally displaced. An inner hollow cylindrical-shaped cathode is concentrically disposed about the inner anodic dissolution baskets. Concentrically disposed about the inner cathode in a spaced manner are a plurality of outer anodic dissolution baskets, while an outer hollow cylindrical-shaped is disposed about the outer anodic dissolution baskets. Uranium is transported from the anode baskets and deposited in a uniform cylindrical shape on the inner and outer cathode cylinders by rotating the anode baskets within the molten lithium halide salt. Scrapers located on each anode basket abrade and remove the spent fuel deposits on the surfaces of the inner and outer cathode cylinders, with the spent fuel falling to the bottom of the cell for removal. Cell resistance is reduced and uranium deposition rate enhanced by increasing the electrode area and reducing the anode-cathode spacing. Collection efficiency is enhanced by trapping and recovery of uranium dendrites scrapped off of the cylindrical cathodes which may be greater in number than two. 12 figs.

  17. Bandgap Engineering in High-Efficiency Multijunction Concentrator Cells

    SciTech Connect (OSTI)

    King, R. R.; Sherif, R. A.; Kinsey, G. S.; Kurtz, S.; Fetzer, C. M.; Edmondson, K. M.; Law, D. C.; Cotal, H. L.; Krut, D. D.; Ermer, J. H.; Karam, N. H.

    2005-08-01

    This paper discusses semiconductor device research paths under investigation with the aim of reaching the milestone efficiency of 40%. A cost analysis shows that achieving very high cell efficiencies is crucial for the realization of cost-effective photovoltaics, because of the strongly leveraging effect of efficiency on module packaging and balance-of systems costs. Lattice-matched (LM) GaInP/ GaInAs/ Ge 3-junction cells have achieved the highest independently confirmed efficiency at 175 suns, 25?C, of 37.3% under the standard AM1.5D, low-AOD terrestrial spectrum. Lattice-mismatched, or metamorphic (MM), materials offer still higher potential efficiencies, if the crystal quality can be maintained. Theoretical efficiencies well over 50% are possible for a MM GaInP/ 1.17-eV GaInAs/ Ge 3-junction cell limited by radiative recombination at 500 suns. The bandgap - open circuit voltage offset, (Eg/q) - Voc, is used as a valuable theoretical and experimental tool to characterize multijunction cells with subcell bandgaps ranging from 0.7 to 2.1 eV. Experimental results are presented for prototype 6-junction cells employing an active {approx}1.1-eV dilute nitride GaInNAs subcell, with active-area efficiency greater than 23% and over 5.3 V open-circuit voltage under the 1-sun AM0 space spectrum. Such cell designs have theoretical efficiencies under the terrestrial spectrum at 500 suns concentration exceeding 55% efficiency, even for lattice-matched designs.

  18. Relationship between fractional pancreatic beta cell area and fasting plasma glucose concentration in monkeys

    E-Print Network [OSTI]

    2010-01-01

    beta cell area and fasting plasma glucose concentration inrelationship between fasting plasma glucose concentrationsfascicularis). Methods Fasting plasma glucose and pancreatic

  19. A flow field enabling operating direct methanol fuel cells with highly concentrated methanol

    E-Print Network [OSTI]

    Zhao, Tianshou

    the cathode potential, but also leads to a waste of fuel, lowering the overall efficiency of fuel cell [5A flow field enabling operating direct methanol fuel cells with highly concentrated methanol Q. Xu Available online 8 October 2010 Keywords: Fuel cells Direct methanol fuel cells Concentrated methanol Flow

  20. Maintaining molten salt electrolyte concentration in aluminum-producing electrolytic cell

    DOE Patents [OSTI]

    Barnett, Robert J.; Mezner, Michael B.; Bradford, Donald R

    2005-01-04

    A method of maintaining molten salt concentration in a low temperature electrolytic cell used for production of aluminum from alumina dissolved in a molten salt electrolyte contained in a cell free of frozen crust wherein volatile material is vented from the cell and contacted and captured on alumina being added to the cell. The captured volatile material is returned with alumina to cell to maintain the concentration of the molten salt.

  1. Flexible thermal cycle test equipment for concentrator solar cells

    DOE Patents [OSTI]

    Hebert, Peter H. (Glendale, CA); Brandt, Randolph J. (Palmdale, CA)

    2012-06-19

    A system and method for performing thermal stress testing of photovoltaic solar cells is presented. The system and method allows rapid testing of photovoltaic solar cells under controllable thermal conditions. The system and method presents a means of rapidly applying thermal stresses to one or more photovoltaic solar cells in a consistent and repeatable manner.

  2. Evaluation of concentration solar cells for terrestrial applications

    E-Print Network [OSTI]

    An, Tao, M. Eng. Massachusetts Institute of Technology

    2008-01-01

    Solar energy has become a hot prospect for the future replacement of fossil fuels, which have limited reserves and cause environmental problems. Solar cell is such a device to directly generate electricity from this clean ...

  3. Microfluidic concentration-enhanced single cell enzyme activity assay

    E-Print Network [OSTI]

    Sarkar, Aniruddh

    2013-01-01

    Cells sense stimuli, process information and respond using signaling networks regulated by enzymatic activity of various proteins. Aberrations in signaling are associated with diseases such as cancer. Most current methods ...

  4. SIMPLE TRANSIENT CALCULATIONS OF CELL FLAMMABLE GAS CONCENTRATIONS

    SciTech Connect (OSTI)

    , J; David Allison , D; John Mccord, J

    2009-05-06

    The Saltstone Facility at Savannah River Site (SRS) mixes low-level radiological liquid waste with grout for permanent disposal as cement in vault cells. The grout mixture is poured into each cell in approximately 17 batches (8 to 10 hours duration). The grout mixture contains ten flammable gases of concern that are released from the mixture into the cell. Prior to operations, simple parametric transient calculations were performed to develop batch parameters (including schedule of batch pours) to support operational efficiency while ensuring that a flammable gas mixture does not develop in the cell vapor space. The analysis demonstrated that a nonflammable vapor space environment can be achieved, with workable operational constraints, without crediting the ventilation flow as a safety system control. Isopar L was identified as the primary flammable gas of concern. The transient calculations balanced inflows of the flammable gases into the vapor space with credited outflows of diurnal breathing through vent holes and displacement from new grout pours and gases generated. Other important features of the analyses included identifying conditions that inhibited a well-mixed vapor space, the expected frequency and duration of such conditions, and the estimated level of stratification that could develop.

  5. Sensitized energy transfer for organic solar cells, optical solar concentrators, and solar pumped lasers

    E-Print Network [OSTI]

    Reusswig, Philip David

    2014-01-01

    The separation of chromophore absorption and excitonic processes, such as singlet exciton fission and photoluminescence, offers several advantages to the design of organic solar cells and luminescent solar concentrators ...

  6. Highly Efficient 32.3% Monolithic GaInP/GaAs/Ge Triple Junction Concentrator Solar Cells

    SciTech Connect (OSTI)

    Cotal, H. L.; Lillington, D. R.; Ermer, J. H.; King, R. R.; Karam, N. H.; Kurtz, S. R.; Friedman, D. J.; Olson, J. M.; Ward, S.; Duda, A.; Emery, K. A.; Moriarty, T.

    2000-01-01

    Based on recent cell improvements for space applications, multijunction cells apear to be ideal candidates for high efficiency, cost effective, PV concentrator systems.

  7. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

    DOE Patents [OSTI]

    Wanlass, Mark W. (Golden, CO)

    1994-01-01

    A single-junction solar cell having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of "pinning" the optimum band gap for a wide range of operating conditions at a value of 1.14.+-.0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap.

  8. EC PVSEC, Glasgow, May 2000 EFFICIENT 20-50 SUN CONCENTRATOR CELLS

    E-Print Network [OSTI]

    concentration system. It comprises two-axis sun-tracking parabolic glass mirrors and a receiver with solar cells. The inability of concentrators to use direct beam sunlight is compensated for by the sun-tracking of the system System for use in the Australian outback. The system comprises two-axis sun- tracking parabolic glass

  9. Tarn Yates, Senior Thesis, Physics Department UCSC Summer 2003 Solar Cells in Concentrating Systems

    E-Print Network [OSTI]

    Drop in Crystalline Silicon Solar Cells. 20 iii. Temperature Dependence of the Spectral and Efficiency. This is because the cost of solar panels compared to the amount of power they produce makes their purchaseTarn Yates, Senior Thesis, Physics Department UCSC Summer 2003 Solar Cells in Concentrating Systems

  10. Energy Yield Determination of Concentrator Solar Cells using Laboratory Measurements: Preprint

    SciTech Connect (OSTI)

    Geisz, John F.; Garcia, Ivan; McMahon, William E.; Steiner, Myles A.; Ochoa, Mario; France, Ryan M.; Habte, Aron; Friedman, Daniel J.

    2015-09-14

    The annual energy conversion efficiency is calculated for a four junction inverted metamorphic solar cell that has been completely characterized in the laboratory at room temperature using measurements fit to a comprehensive optoelectronic model of the multijunction solar cells. A simple model of the temperature dependence is used to predict the performance of the solar cell under varying temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric concentration, CPV system thermal characteristics, and luminescent coupling are highlighted. temperature and spectra characteristic of Golden, CO for an entire year. The annual energy conversion efficiency is calculated by integrating the predicted cell performance over the entire year. The effects of geometric concentration, CPV system thermal characteristics, and luminescent coupling are highlighted.

  11. Optimized scalable stack of fluorescent solar concentrator systems with bifacial silicon solar cells

    SciTech Connect (OSTI)

    Martínez Díez, Ana Luisa, E-mail: a.martinez@itma.es [Fundación ITMA, Parque Empresarial Principado de Asturias, C/Calafates, Parcela L-3.4, 33417 Avilés (Spain); Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany); Gutmann, Johannes; Posdziech, Janina; Rist, Tim; Goldschmidt, Jan Christoph [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstr. 2, 79110 Freiburg (Germany); Plaza, David Gómez [Fundación ITMA, Parque Empresarial Principado de Asturias, C/Calafates, Parcela L-3.4, 33417 Avilés (Spain)

    2014-10-21

    In this paper, we present a concentrator system based on a stack of fluorescent concentrators (FCs) and a bifacial solar cell. Coupling bifacial solar cells to a stack of FCs increases the performance of the system and preserves its efficiency when scaled. We used an approach to optimize a fluorescent solar concentrator system design based on a stack of multiple fluorescent concentrators (FC). Seven individual fluorescent collectors (20 mm×20 mm×2 mm) were realized by in-situ polymerization and optically characterized in regard to their ability to guide light to the edges. Then, an optimization procedure based on the experimental data of the individual FCs was carried out to determine the stack configuration that maximizes the total number of photons leaving edges. Finally, two fluorescent concentrator systems were realized by attaching bifacial silicon solar cells to the optimized FC stacks: a conventional system, where FC were attached to one side of the solar cell as a reference, and the proposed bifacial configuration. It was found that for the same overall FC area, the bifacial configuration increases the short-circuit current by a factor of 2.2, which is also in agreement with theoretical considerations.

  12. Single-junction solar cells with the optimum band gap for terrestrial concentrator applications

    DOE Patents [OSTI]

    Wanlass, M.W.

    1994-12-27

    A single-junction solar cell is described having the ideal band gap for terrestrial concentrator applications. Computer modeling studies of single-junction solar cells have shown that the presence of absorption bands in the direct spectrum has the effect of ''pinning'' the optimum band gap for a wide range of operating conditions at a value of 1.14[+-]0.02 eV. Efficiencies exceeding 30% may be possible at high concentration ratios for devices with the ideal band gap. 7 figures.

  13. Non Invasive estimation of aluminum concentration in Hall-Heroult reduction cells

    SciTech Connect (OSTI)

    David Bell

    2004-03-01

    The present best practice for the preparation of primary aluminum is by electrolysis of alumina in the traditional Hall-Heroult reduction cell. The process conditions in the electrolyte of this cell required for the reduction to proceed are sufficiently harsh to have precluded the implementation of in situ sensing of the electrolyte composition, specifically the concentration of the ionized alumina. This report reveals the theoretical basis for a non-invasive method for estimation of the ionized alumina concentration which does not require the use of any sensor in direct contact with the cell electrolyte. The proposed method can in principle be applied with equal efficacy to the so-called drained cathode cell designs and to cells having any anode composition, because only knowledge of the electrolyte conduction behavior is required a priori. For an operating cell, the proposed method requires only readily available electrical measurements and the facilities to process the acquired signals. The proposed method rests on the ability to identify certain characteristics of the transients in the reduction cell terminal voltages caused by the quasiperiodic introduction of alumina. It will be shown that these voltage transients manifest measurable properties, in a statistical sense, that should permit estimation of the ionized alumina concentration with a delay of one alumina feed cycle. The next logical step following the present work, consistent with the Aluminum Technology Roadmap [1], is to experimentally verify the predictions made here; no doubt practical refinements to the proposed approach will evolve during the course of experimentation. Successful verification of the proposed estimation method will permit the design of reduction cell control algorithms based directly on the mass balance of alumina in the electrolyte. This report assumes that the reader understands certain basic concepts important to the operation of electrolytic cells, and the Hall-Heroult cell in particular. References [2,3] provide such concepts in a manner accessible to the technically educated reader; reference [6] is a more thorough treatment.

  14. Design, processing, and assembly of large area concentrator cells and subassemblies

    SciTech Connect (OSTI)

    Tobin, S.P.; Landis, G.A.; Nowian, M.J.

    1982-09-01

    This paper describes the development of silicon concentrator cells for use in state-of-the-art linear focus Fresnel lens systems with average sunlight concentration of 30-50 suns. Primary goals were high cell efficiency and a simple, producible, low cost process. In the design phase, a collecting grid pattern optimized for the nonuniform intensity profile of the Fresnel lens was developed. A simple baseline cell process was defined, similar to the ion implanted flat-plate cell process. The most noticeable differences were the silicon resistivity (0.3 ohm-cm), texture etched surfaces to improve current collection, and the grid pattern. Initial cell results measured by Sandia were quite good, with efficiency exceeding 18% at 50 suns. Nine-cell strings interconnected and bonded to glass were delivered to the concentrator system manufacturer and passed all electrical and environmental tests. Also described are several efficiency-enhancing options to the baseline process. These include improved junction anneal schedules, oxide surface passivation, multi-layer antireflection coatings, and a planar process to reduce leakage currents.

  15. Effect of water concentration in the anode catalyst layer on the performance of direct methanol fuel cells operating

    E-Print Network [OSTI]

    Zhao, Tianshou

    Effect of water concentration in the anode catalyst layer on the performance of direct methanol fuel cells operating with neat methanol Q.X. Wu a , S.Y. Shen a , Y.L. He b , T.S. Zhao a cells Direct methanol fuel cells Neat methanol Water concentration a b s t r a c t This paper reports

  16. Electrolyte Concentration Effect of a Photoelectrochemical Cell Consisting of TiO 2 Nanotube Anode

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

    Ren, Kai; Gan, Yong X.; Nikolaidis, Efstratios; Sofyani, Sharaf Al; Zhang, Lihua

    2013-01-01

    The photoelectrochemical responses of a TiO 2 nanotube anode in ethylene glycol (EG), glycerol, ammonia, ethanol, urea, and Na 2 S electrolytes with different concentrations were investigated. The TiO 2 nanotube anode was highly efficient in photoelectrocatalysis in these solutions under UV light illumination. The photocurrent density is obviously affected by the concentration change. Na 2 S generated the highest photocurrent density at 0, 1, and 2?V bias voltages, but its concentration does not significantly affect the photocurrent density. Urea shows high open circuit voltage at proper concentration and low photocurrent at different concentrations. Externally applied bias voltage ismore »also an important factor that changes the photoelectrochemical reaction process. In view of the open circuit voltage, EG, ammonia, and ethanol fuel cells show the trend that the open circuit voltage (OCV) increases with the increase of the concentration of the solutions. Glycerol has the highest OCV compared with others, and it deceases with the increase in the concentration because of the high viscosity. The OCV of the urea and Na 2 S solutions did not show obvious concentration effect. « less

  17. Effects of Spectral Error in Efficiency Measurements of GaInAs-Based Concentrator Solar Cells

    SciTech Connect (OSTI)

    Osterwald, C. R.; Wanlass, M. W.; Moriarty, T.; Steiner, M. A.; Emery, K. A.

    2014-03-01

    This technical report documents a particular error in efficiency measurements of triple-absorber concentrator solar cells caused by incorrect spectral irradiance -- specifically, one that occurs when the irradiance from unfiltered, pulsed xenon solar simulators into the GaInAs bottom subcell is too high. For cells designed so that the light-generated photocurrents in the three subcells are nearly equal, this condition can cause a large increase in the measured fill factor, which, in turn, causes a significant artificial increase in the efficiency. The error is readily apparent when the data under concentration are compared to measurements with correctly balanced photocurrents, and manifests itself as discontinuities in plots of fill factor and efficiency versus concentration ratio. In this work, we simulate the magnitudes and effects of this error with a device-level model of two concentrator cell designs, and demonstrate how a new Spectrolab, Inc., Model 460 Tunable-High Intensity Pulsed Solar Simulator (T-HIPSS) can mitigate the error.

  18. Method of monitoring CO concentrations in hydrogen feed to a PEM fuel cell

    DOE Patents [OSTI]

    Grot, Stephen Andreas (Rochester, NY); Meltser, Mark Alexander (Pittsford, NY); Gutowski, Stanley (Pittsford, NY); Neutzler, Jay Kevin (Rochester, NY); Borup, Rodney Lynn (East Rochester, NY); Weisbrod, Kirk (Los Alamos, NM)

    2000-01-01

    The CO concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H.sub.2 fuel stream. The PEM-probe is intermittently purged of any CO build-up on the anode catalyst (e.g., by (1) flushing the anode with air, (2) short circuiting the PEM-probe, or (3) reverse biasing the PEM-probe) to keep the PEM-probe at peak performance levels.

  19. Concentration-dependent gene expression responses to flusilazole in embryonic stem cell differentiation cultures

    SciTech Connect (OSTI)

    Dartel, Dorien A.M. van; Pennings, Jeroen L.A.; Fonteyne, Liset J.J. de la; Brauers, Karen J.J.; Claessen, Sandra; Delft, Joost H. van; Kleinjans, Jos C.S.; Piersma, Aldert H.

    2011-03-01

    The murine embryonic stem cell test (EST) is designed to evaluate developmental toxicity based on compound-induced inhibition of embryonic stem cell (ESC) differentiation into cardiomyocytes. The addition of transcriptomic evaluation within the EST may result in enhanced predictability and improved characterization of the applicability domain, therefore improving usage of the EST for regulatory testing strategies. Transcriptomic analyses assessing factors critical for risk assessment (i.e. dose) are needed to determine the value of transcriptomic evaluation in the EST. Here, using the developmentally toxic compound, flusilazole, we investigated the effect of compound concentration on gene expression regulation and toxicity prediction in ESC differentiation cultures. Cultures were exposed for 24 h to multiple concentrations of flusilazole (0.54-54 {mu}M) and RNA was isolated. In addition, we sampled control cultures 0, 24, and 48 h to evaluate the transcriptomic status of the cultures across differentiation. Transcriptomic profiling identified a higher sensitivity of development-related processes as compared to cell division-related processes in flusilazole-exposed differentiation cultures. Furthermore, the sterol synthesis-related mode of action of flusilazole toxicity was detected. Principal component analysis using gene sets related to normal ESC differentiation was used to describe the dynamics of ESC differentiation, defined as the 'differentiation track'. The concentration-dependent effects on development were reflected in the significance of deviation of flusilazole-exposed cultures from this transcriptomic-based differentiation track. Thus, the detection of developmental toxicity in EST using transcriptomics was shown to be compound concentration-dependent. This study provides further insight into the possible application of transcriptomics in the EST as an improved alternative model system for developmental toxicity testing.

  20. Development of metallization for GaAs and AlGaAs concentrator solar cells

    SciTech Connect (OSTI)

    Tobin, S.P.

    1987-04-01

    A three-layer metallization system was developed for high temperature stability on GaAs and AlGaAs solar cells. The layers are a Pt ohmic contact metal that forms thermally stable compounds with GaAs, a TiN diffusion barrier, and a gold conductor. The solar cell structure was also designed for contact stability, with the key component being a heavily doped GaAs cap layer. Reactively sputtered TiN was found to act as an excellent barrier when deposited under the proper conditions. The conditions were carefully optimized for low resistivity and low stress in the films. A low but nonzero substrate bias during sputtering was found to be important. Solar cells with sputtered metallizations of Pt/TiN/Ti/Pt/Au were found to be thermally stable up to 500/sup 0/C for 15 minutes in vacuum. At 600/sup 0/C there was catastrophic degradation of the cells due to dissociation of uncapped GaAs surfaces. Below this temperature the metallization performed as designed. The Pt and GaAs layers reacted to form a stable PtGa compound layer that gave low contact resistance. There was no penetration of Au or GaAs through the barrier layer. These results are a very encouraging first step leading to stable, reliable GaAs and AlGaAs concentrator cells.

  1. Cytokine-capture nanoparticles to quantify IL-2 concentrations within the immunological synapse during T cell activation

    E-Print Network [OSTI]

    Hong, Julee Y. (Julee Yang-A.), 1980-

    2003-01-01

    The feasibility of bringing a nascent technology for detection and quantification of local cytokine concentrations on cell surfaces to market is presented in this paper. Quantum dots or fluorochrome-loaded nanoparticles ...

  2. Advances on multijunction solar cell characterization aimed at the optimization of real concentrator performance

    SciTech Connect (OSTI)

    Garcia-Linares, Pablo Dominguez, César Voarino, Philippe Besson, Pierre Baudrit, Mathieu

    2014-09-26

    Multijunction solar cells (MJSC) are usually developed to maximize efficiency under test conditions and not under real operation. This is the case of anti-reflective coatings (ARC), which are meant to minimize Fresnel reflection losses for a family of incident rays at room temperature. In order to understand and quantify the discrepancies between test and operation conditions, we have experimentally analyzed the spectral response of MJSC for a variety of incidence angles that are in practice received by a concentrator cell in high-concentration photovoltaic (HCPV) receiver designs. Moreover, we characterize this angular dependence as a function of temperature in order to reproduce real operation conditions. As the refractive index of the silicone is dependent on temperature, an optical mismatch is expected. Regarding other characterization techniques, a method called Relative EL Homogeneity Analysis (RELHA) is applied to processed wafers prior to dicing, allowing to diagnose the wafer crystalline homogeneity for each junction. Finally, current (I)-voltage (V) characterization under strongly unbalanced light spectra has also been carried out for a number of low-level irradiances, providing insight on each junction shunt resistance and corresponding radiative coupling.

  3. Low-Cost Photovoltaics: Luminescent Solar Concentrators And Colloidal Quantum Dot Solar Cells

    E-Print Network [OSTI]

    Leow, Shin Woei

    2014-01-01

    A. Büchtemann, “A luminescent solar concentrator with 7.1%simulations of luminescent solar concentrators for buildingVanmaekelbergh, “Luminescent Solar Concentrators - A review

  4. Low-Cost Photovoltaics: Luminescent Solar Concentrators And Colloidal Quantum Dot Solar Cells

    E-Print Network [OSTI]

    Leow, Shin Woei

    2014-01-01

    using front-facing photovoltaic cell luminescent solarwith front-facing photovoltaic cells using weighted Montefor tandem photovoltaic cells,” Thin Solid Films, vol. 516,

  5. Low-Cost Photovoltaics: Luminescent Solar Concentrators And Colloidal Quantum Dot Solar Cells

    E-Print Network [OSTI]

    Leow, Shin Woei

    2014-01-01

    Organic Solar Concentrators for Photovoltaics,” Science,Polymer Photovoltaics for Solar Energy Conversion,” Adv.solar concentrators for building integrated photovoltaics,”

  6. InP single-junction concentrator cell. Semi-annual report, October 1, 1980-March 31, 1981

    SciTech Connect (OSTI)

    Gregory, P.E.

    1981-01-01

    The purpose of this work is to develop a glass-sealed back-contacted InP or InGaAsP solar cell for use in concentrator systems. Work to be performed in developing this cell includes growing the InP epitaxial layers needed for cells and test structures, developing a model to be used in optimizing the cell structure, measurement of InP parameters necessary for use in the model, and developing the glass-bonding and back-contacting scheme. Accomplishments in these areas are discussed.

  7. Modulation of ATP/ADP Concentration at the Endothelial Cell Surface by Flow: Effect of Cell Topography

    E-Print Network [OSTI]

    Choi, Hyo Won; Barakat, Abdul I.

    2009-01-01

    of the surface topography of living endothelial cells imagedby Flow: Effect of Cell Topography H YO W ON C HOI and AChannel length, L (lm) Cell topography values are based on

  8. Effect of different amounts and types of calcium on colonic cell proliferation and fecal bile acids concentration 

    E-Print Network [OSTI]

    C?hen Hsiao-Ch?ing

    1991-01-01

    EFFECT OF DIFFERENT AMOUNTS AND TYPES OF CALCIUM ON COLOiVIC CELL PROLIFERATION AND FECAL BILE ACIDS CONCENTRATION A Thesis by XIAO-QING CHEN Submitted to the Office of Graduate Studies of Texas ARM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1991 Major Subject: Nutrition EFFECT OF DIFFERENT AMOUNTS AND TYPES OF CALCIUM ON COLONIC CELL PROLIFERATION AND FECAL BILE ACIDS CONCENTRATION A Thesis by X1AO-QING CHEN Approved as to style...

  9. Periodically multilayered planar optical concentrator for photovoltaic solar cells Manuel E. Solano, Muhammad Faryad, Peter B. Monk, Thomas E. Mallouk, and Akhlesh Lakhtakia

    E-Print Network [OSTI]

    Periodically multilayered planar optical concentrator for photovoltaic solar cells Manuel E. Solano concentrator for photovoltaic solar cells Manuel E. Solano,1 Muhammad Faryad,2 Peter B. Monk,1 Thomas E-Si solar cells due to embedded nanoparticles J. Appl. Phys. 102, 093713 (2007); 10.1063/1.2809368 Surface

  10. Variation of carrier concentration and interface trap density in 8MeV electron irradiated c-Si solar cells

    SciTech Connect (OSTI)

    Bhat, Sathyanarayana, E-mail: asharao76@gmail.com; Rao, Asha, E-mail: asharao76@gmail.com [Department of Physics, Mangalore Institute of Technology and Engineering, Moodabidri, Mangalore-574225 (India); Krishnan, Sheeja [Department of Physics, Sri Devi Institute of Technology, Kenjar, Mangalore-574142 (India); Sanjeev, Ganesh [Microtron Centre, Department of Physics, Mangalore University, Mangalagangothri-574199 (India); Suresh, E. P. [Solar Panel Division, ISRO Satellite Centre, Bangalore-560017 (India)

    2014-04-24

    The capacitance and conductance measurements were carried out for c-Si solar cells, irradiated with 8 MeV electrons with doses ranging from 5kGy – 100kGy in order to investigate the anomalous degradation of the cells in the radiation harsh environments. Capacitance – Voltage measurements indicate that there is a slight reduction in the carrier concentration upon electron irradiation due to the creation of radiation induced defects. The conductance measurement results reveal that the interface state densities and the trap time constant increases with electron dose due to displacement damages in c-Si solar cells.

  11. Concentration of Cryoprotectant in water-in-oil microdroplets for single cell vitrificaton

    E-Print Network [OSTI]

    Bajpayee, Anurag

    2008-01-01

    (cont.) Droplets with an initial concentration of IM were found to be concentrated to about 3-4M in 90s while droplets starting at 2M were concentrated to 6M in about the same time. The entire process takes place over a ...

  12. Intracellular L-arginine concentration does not determine NO production in endothelial cells: Implications on the 'L-arginine paradox'

    SciTech Connect (OSTI)

    Shin, Soyoung; Mohan, Srinidi; Fung, Ho-Leung

    2011-11-04

    Highlights: Black-Right-Pointing-Pointer Our findings provide a possible solution to the 'L-arginine paradox'. Black-Right-Pointing-Pointer Extracellular L-arginine concentration is the major determinant of NO production. Black-Right-Pointing-Pointer Cellular L-arginine action is limited by cellular ARG transport, not the K{sub m} of NOS. Black-Right-Pointing-Pointer We explain how L-arginine supplementation can work to increase endothelial function. -- Abstract: We examined the relative contributory roles of extracellular vs. intracellular L-arginine (ARG) toward cellular activation of endothelial nitric oxide synthase (eNOS) in human endothelial cells. EA.hy926 human endothelial cells were incubated with different concentrations of {sup 15}N{sub 4}-ARG, ARG, or L-arginine ethyl ester (ARG-EE) for 2 h. To modulate ARG transport, siRNA for ARG transporter (CAT-1) vs. sham siRNA were transfected into cells. ARG transport activity was assessed by cellular fluxes of ARG, {sup 15}N{sub 4}-ARG, dimethylarginines, and L-citrulline by an LC-MS/MS assay. eNOS activity was determined by nitrite/nitrate accumulation, either via a fluorometric assay or by{sup 15}N-nitrite or estimated {sup 15}N{sub 3}-citrulline concentrations when {sup 15}N{sub 4}-ARG was used to challenge the cells. We found that ARG-EE incubation increased cellular ARG concentration but no increase in nitrite/nitrate was observed, while ARG incubation increased both cellular ARG concentration and nitrite accumulation. Cellular nitrite/nitrate production did not correlate with cellular total ARG concentration. Reduced {sup 15}N{sub 4}-ARG cellular uptake in CAT-1 siRNA transfected cells vs. control was accompanied by reduced eNOS activity, as determined by {sup 15}N-nitrite, total nitrite and {sup 15}N{sub 3}-citrulline formation. Our data suggest that extracellular ARG, not intracellular ARG, is the major determinant of NO production in endothelial cells. It is likely that once transported inside the cell, ARG can no longer gain access to the membrane-bound eNOS. These observations indicate that the 'L-arginine paradox' should not consider intracellular ARG concentration as a reference point.

  13. Estrogen induced concentration dependent differential gene expression in human breast cancer (MCF7) cells: Role of transcription factors

    SciTech Connect (OSTI)

    Chandrasekharan, Sabarinath; Kandasamy, Krishna Kumar; Dayalan, Pavithra; Ramamurthy, Viraragavan

    2013-08-02

    Highlights: •Estradiol (E2) at low dose induced cell proliferation in breast cancer cells. •E2 at high concentration induced cell stress in breast cancer cells. •Estrogen receptor physically interacts only with a few transcription factors. •Differential expression of genes with Oct-1 binding sites increased under stress. •Transcription factor binding sites showed distinct spatial distribution on genes. -- Abstract: Background: Breast cancer cells respond to estrogen in a concentration dependent fashion, resulting in proliferation or apoptosis. The mechanism of this concentration dependent differential outcome is not well understood yet. Methodology: Meta-analysis of the expression data of MCF7 cells treated with low (1 nM) or high (100 nM) dose of estradiol (E2) was performed. We identified genes differentially expressed at the low or the high dose, and examined the nature of regulatory elements in the vicinity of these genes. Specifically, we looked for the difference in the presence, abundance and spatial distribution of binding sites for estrogen receptor (ER) and selected transcription factors (TFs) in the genomic region up to 25 kb upstream and downstream from the transcription start site (TSS) of these genes. Results: It was observed that at high dose E2 induced the expression of stress responsive genes, while at low dose, genes involved in cell cycle were induced. We found that the occurrence of transcription factor binding regions (TFBRs) for certain factors such as Sp1 and SREBP1 were higher on regulatory regions of genes expressed at low dose. At high concentration of E2, genes with a higher frequency of Oct-1 binding regions were predominantly involved. In addition, there were differences in the spatial distribution pattern of the TFBRs in the genomic regions among the two sets of genes. Discussion: E2 induced predominantly proliferative/metabolic response at low concentrations; but at high concentration, stress–rescue responses were induced. At high E2 concentration, classical genomic pathway involving ER binding to the regulatory regions was reduced, and alternate or indirect activation of genes through Oct-1 became more prominent.

  14. Optimized III-V Multijunction Concentrator Solar Cells on Patterned Si and Ge Substrates: Final Technical Report, 15 September 2004--30 September 2006

    SciTech Connect (OSTI)

    Ringel, S. A.

    2008-11-01

    Goal is to demo realistic path to III-V multijunction concentrator efficiencies > 40% by substrate-engineering combining compositional grading with patterned epitaxy for small-area cells for high concentration.

  15. Sonic hedgehog stimulates the proliferation of rat gastric mucosal cells through ERK activation by elevating intracellular calcium concentration

    SciTech Connect (OSTI)

    Osawa, Hiroyuki [Department of Gastroenterology, Jichi Medical School, Tochigi 329-0498 (Japan); Ohnishi, Hirohide [Department of Gastroenterology, Jichi Medical School, Tochigi 329-0498 (Japan)]. E-mail: hohnishi@jichi.ac.jp; Takano, Koji [Department of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo 113-8655 (Japan); Noguti, Takasi [Department of Nephrology and Endocrinology, University of Tokyo School of Medicine, Tokyo 113-8655 (Japan); Mashima, Hirosato [Department of Gastroenterology, University of Tokyo School of Medicine, Tokyo 113-8655 (Japan); Hoshino, Hiroko [Department of Gastroenterology, Jichi Medical School, Tochigi 329-0498 (Japan); Kita, Hiroto [Department of Gastroenterology, Jichi Medical School, Tochigi 329-0498 (Japan); Sato, Kiichi [Department of Gastroenterology, Jichi Medical School, Tochigi 329-0498 (Japan); Matsui, Hirofumi [Division of Gastroenterology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki 305-8576 (Japan); Sugano, Kentaro [Department of Gastroenterology, Jichi Medical School, Tochigi 329-0498 (Japan)

    2006-06-02

    Sonic Hedgehog (Shh), a member of hedgehog peptides family, is expressed in gastric gland epithelium. To elucidate Shh function to gastric mucosal cells, we examined the effect of Shh on the proliferation of a rat normal gastric mucosal cell line, RGM-1. RGM-1 cells express essential components of Shh receptor system, patched-1, and smoothened. Shh enhanced DNA synthesis in RGM-1 cells and elevated intracellular calcium concentration ([Ca{sup 2+}]{sub i}). In addition, Shh as well as calcium ionophore A32187 rapidly activated ERK. However, Shh failed to activate ERK under calcium-free culture condition. Pretreatment of cells with PD98059 attenuated the DNA synthesis promoted by Shh. Moreover, when cells were pretreated with cyclopamine, Shh could not elevate [Ca{sup 2+}]{sub i}, activate ERK or promote DNA synthesis. On the other hand, although Shh induced Gli-1 nuclear accumulation in RGM-1 cells, Shh activated ERK even in cells pretreated with actinomycin D. These results indicate that Shh promotes the proliferation of RGM-1 cells through an intracellular calcium- and ERK-dependent but transcription-independent pathway via Patched/Smoothened receptor system.

  16. A Microfluidic Cell Concentrator Jay Warrick, Ben Casavant, Megan Frisk, and David Beebe*

    E-Print Network [OSTI]

    Beebe, David J.

    parameter and is typically controlled using the process of centrifugation and resuspension. However, if the number of cells is small enough, the resuspension volume needed to achieve a desired density can become to work with such small volumes: bubbles can interfere with cell handling and resuspension, cells may

  17. Low-Cost Photovoltaics: Luminescent Solar Concentrators And Colloidal Quantum Dot Solar Cells

    E-Print Network [OSTI]

    Leow, Shin Woei

    2014-01-01

    concentrators for building integrated photovoltaics,” 2013,the performance of building integrated photovoltaics,” Sol.evaluation of building-integrated photovoltaics,” Energy,

  18. Effects of drugs in subtoxic concentrations on the metabolic fluxes in human hepatoma cell line Hep G2

    SciTech Connect (OSTI)

    Niklas, Jens [Biochemical Engineering Institute, Saarland University, Campus A1.5, D-66123 Saarbruecken (Germany); Noor, Fozia, E-mail: fozia.noor@mx.uni-saarland.d [Biochemical Engineering Institute, Saarland University, Campus A1.5, D-66123 Saarbruecken (Germany); Heinzle, Elmar [Biochemical Engineering Institute, Saarland University, Campus A1.5, D-66123 Saarbruecken (Germany)

    2009-11-01

    Commonly used cytotoxicity assays assess the toxicity of a compound by measuring certain parameters which directly or indirectly correlate to the viability of the cells. However, the effects of a given compound at concentrations considerably below EC{sub 50} values are usually not evaluated. These subtoxic effects are difficult to identify but may eventually cause severe and costly long term problems such as idiosyncratic hepatotoxicity. We determined the toxicity of three hepatotoxic compounds, namely amiodarone, diclofenac and tacrine on the human hepatoma cell line Hep G2 using an online kinetic respiration assay and analysed the effects of subtoxic concentrations of these drugs on the cellular metabolism by using metabolic flux analysis. Several changes in the metabolism could be detected upon exposure to subtoxic concentrations of the test compounds. Upon exposure to diclofenac and tacrine an increase in the TCA-cycle activity was observed which could be a signature of an uncoupling of the oxidative phosphorylation. The results indicate that metabolic flux analysis could serve as an invaluable novel tool for the investigation of the effects of drugs. The described methodology enables tracking the toxicity of compounds dynamically using the respiration assay in a range of concentrations and the metabolic flux analysis permits interesting insights into the changes in the central metabolism of the cell upon exposure to drugs.

  19. GaInP/GaAs/GaInAs Monolithic Tandem Cells for High-Performance Solar Concentrators

    SciTech Connect (OSTI)

    Wanlass, M. W.; Ahrenkiel, S. P.; Albin, D. S.; Carapella, J. J.; Duda, A.; Emery, K.; Geisz, J. F.; Jones, K.; Kurtz, S.; Moriarty, T.; Romero, M. J.

    2005-08-01

    We present a new approach for ultra-high-performance tandem solar cells that involves inverted epitaxial growth and ultra-thin device processing. The additional degree of freedom afforded by the inverted design allows the monolithic integration of high-, and medium-bandgap, lattice-matched (LM) subcell materials with lower-bandgap, lattice-mismatched (LMM) materials in a tandem structure through the use of transparent compositionally graded layers. The current work concerns an inverted, series-connected, triple-bandgap, GaInP (LM, 1.87 eV)/GaAs (LM, 1.42 eV)/GaInAs (LMM, {approx}1 eV) device structure grown on a GaAs substrate. Ultra-thin tandem devices are fabricated by mounting the epiwafers to pre-metallized Si wafer handles and selectively removing the parent GaAs substrate. The resulting handle-mounted, ultra-thin tandem cells have a number of important advantages, including improved performance and potential reclamation/reuse of the parent substrate for epitaxial growth. Additionally, realistic performance modeling calculations suggest that terrestrial concentrator efficiencies in the range of 40-45% are possible with this new tandem cell approach. A laboratory-scale (0.24 cm2), prototype GaInP/GaAs/GaInAs tandem cell with a terrestrial concentrator efficiency of 37.9% at a low concentration ratio (10.1 suns) is described, which surpasses the previous world efficiency record of 37.3%.

  20. 0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1eV)/GaInAs(0.7eV) Four-Junction Solar Cell

    SciTech Connect (OSTI)

    Friedman, D. J.; Geisz, J. F.; Norman, A. G.; Wanlass, M. W.; Kurtz, S. R.

    2006-01-01

    We discuss recent developments in III-V multijunction solar cells, focusing on adding a fourth junction to the Ga{sub 0.5}In{sub 0.5} P/GaAs/Ga{sub 0.75}In{sub 0.25}As inverted three-junction cell. This cell, grown inverted on GaAs so that the lattice-mismatched Ga{sub 0.75}In{sub 0.25}As third junction is the last one grown, has demonstrated 38% efficiency, and 40% is likely in the near future. To achieve still further gains, a lower-bandgap Ga{sub x}In{sub 1-x}As fourth junction could be added to the three-junction structure for a four-junction cell whose efficiency could exceed 45% under concentration. Here, we present the initial development of the Ga{sub x}In{sub 1-x}As fourth junction. Junctions of various bandgaps ranging from 0.88 to 0.73 eV were grown, in order to study the effect of the different amounts of lattice mismatch. At a bandgap of 0.88 eV, junctions were obtained with very encouraging {approx}80% quantum efficiency, 57% fill factor, and 0.36 eV open-circuit voltage. The device performance degrades with decreasing bandgap (i.e., increasing lattice mismatch). We model the four-junction device efficiency vs. fourth junction bandgap to show that an 0.7-eV fourth-junction bandgap, while optimal if it could be achieved in practice, is not necessary; an 0.9-eV bandgap would still permit significant gains in multijunction cell efficiency while being easier to achieve than the lower-bandgap junction.

  1. Modulation of ATP/ADP Concentration at the Endothelial Cell Surface by Flow: Effect of Cell Topography

    E-Print Network [OSTI]

    Choi, Hyo Won; Barakat, Abdul I.

    2009-01-01

    is the maximum enzyme reaction velocity for ATP hydrolysis,et al. 10 Maximum reaction velocity per area assumes a cell

  2. Terrestrial Concentrator PV Modules Based on GaInP/GaAs/Ge TJ Cells and Minilens Panels

    SciTech Connect (OSTI)

    Rumyantsev, V. D.; Sadchikov, N. A.; Chalov, A. E.; Ionova, E. A.; Friedman, D. J.; Glenn, G.

    2006-01-01

    This paper is a description of research activity in the field of cost-effective modules realizing the concept of very high solar concentration with small-aperture area Fresnel lenses and multijunction III-V cells. Structural simplicity and 'all-glass' design are the guiding principles of the corresponding development. The advanced concentrator modules are made with silicone Fresnel lens panels (from 8 up to 144 lenses, each lens is 4 times 4 cm{sup 2} in aperture area) with composite structure. GaInP/GaAs/Ge triple-junction cells with average efficiencies of 31.1 and 34.7% at 1000 suns were used for the modules. Conversion efficiency as high as 26.3% has been measured indoors in a test module using a newly developed large-area solar simulator.

  3. Performance of a Polymer Electrolyte Membrane Fuel Cell Exposed to Transient CO Concentrations

    E-Print Network [OSTI]

    Van Zee, John W.

    fuel cell PEMFC . The data include relatively high 500 and 3000 ppm CO levels at 70°C cell temperature PEMFC applications. Poisoning and recovery rates are reported for saturated conditions and these rates are suitable for verifying numerical models of a PEMFC and establishing a baseline for new recovery schemes

  4. Current flow and efficiencies of concentrator InGaP/GaAs/Ge solar cells at temperatures below 300K

    SciTech Connect (OSTI)

    Kalinovsky, Vitaly S. Kontrosh, Evgeny V. Dmitriev, Pavel A. Pokrovsky, Pavel V. Chekalin, Alexander V. Andreev, Viacheslav M.

    2014-09-26

    The forward dark current density – voltage (J-V) characteristic is one of the most important characteristics of multi-junction solar cells. It indicates that the mechanisms of current flow in the space charge region of photoactive p-n junctions. If one is to idealize the optical and electrical (coupling) elements of the solar cells, it is the J-V characteristic that determines the theoretically possible efficiency of the solar cell. In this paper, using the connection between the dark J-V and photovoltaic (?-J{sub g}) efficiency – generated current density characteristics, the effect of current transport mechanisms in the space charge on the efficiency of multi-junction solar cells was investigated in the temperature range of 300 – 80 K. In the experimental J-V and ?-J{sub g} curves of the multi-junction solar cells, segments corresponding to the dominant current transport mechanisms were identified. The developed method, based on the analysis of forward dark J-V characteristics, makes it possible to identify the parameters affecting the efficiency of the multi-junction solar cells in a wide range of temperatures and solar radiation concentration.

  5. Manufacturing of High-Efficiency Bi-Facial Tandem Concentrator Solar Cells: February 20, 2009--August 20, 2010

    SciTech Connect (OSTI)

    Wojtczuk , S.

    2011-06-01

    Spire Semiconductor made concentrator photovoltaic (CPV) cells using a new bi-facial growth process and met both main program goals: a) 42.5% efficiency 500X (AM1.5D, 25C, 100mW/cm2); and b) Ready to supply at least 3MW/year of such cells at end of program. We explored a unique simple fabrication process to make a N/P 3-junction InGaP/GaAs/InGaAs tandem cells . First, the InGaAs bottom cell is grown on the back of a GaAs wafer. The wafers are then loaded into a cassette, spin-rinsed to remove particles, dipped in dilute NH4OH and spin-dried. The wafers are then removed from the cassette loaded the reactor for GaAs middle and InGaP top cell growth on the opposite wafer face (bi-facial growth). By making the epitaxial growth process a bit more complex, we are able to avoid more complex processing (such as large area wafer bonding or epitaxial liftoff) used in the inverted metamorphic (IMM) approach to make similar tandem stacks. We believe the yield is improved compared to an IMM process. After bi-facial epigrowth, standard III-V cell steps (back metal, photolithography for front grid, cap etch, AR coat, dice) are used in the remainder of the process.

  6. Low-Cost Photovoltaics: Luminescent Solar Concentrators And Colloidal Quantum Dot Solar Cells

    E-Print Network [OSTI]

    Leow, Shin Woei

    2014-01-01

    S. Lewis, “Toward Cost-Effective Solar Energy Use,” Science,D. S. Ginley, “Low-Cost Inorganic Solar Cells: From Ink Toto lowering the cost of solar electricity production with

  7. Relationship between beta-cell mass and fasting blood glucose concentration in humans

    E-Print Network [OSTI]

    Ritzel, Robert A; Butler, Alexandra E; Rizza, Robert A; Veldhuis, Johannes D; Butler, Peter C

    2006-01-01

    Between ?-Cell Mass and Fasting Blood Glucose Concentrationnondiabetic, had impaired fasting glu- cose, or had type 26.9 kg/m 2 ), had impaired fasting glucose (?110 mg/dl [6.1

  8. 0.7-eV GaInAs Junction for a GaInP/GaAs/GaInAs(1-eV)/GaInAs(0.7-eV) Four-Junction Solar Cell: Preprint

    SciTech Connect (OSTI)

    Friedman, D. J.; Geisz, J. F.; Norman, A. G.; Wanlass, M. W.; Kurtz, S. R.

    2006-05-01

    We discuss recent developments in III-V multijunction solar cells, focusing on adding a fourth junction to the Ga0.5In0.5P/GaAs/Ga0.75In0.25As inverted three-junction cell. This cell, grown inverted on GaAs so that the lattice-mismatched Ga0.75In0.25As third junction is the last one grown, has demonstrated 38% efficiency, and 40% is likely in the near future. To achieve still further gains, a lower-bandgap GaxIn1-xAs fourth junction could be added to the three-junction structure for a four-junction cell whose efficiency could exceed 45% under concentration. Here, we present the initial development of the GaxIn1-xAs fourth junction. Junctions of various bandgaps ranging from 0.88 to 0.73 eV were grown, in order to study the effect of the different amounts of lattice mismatch. At a bandgap of 0.88 eV, junctions were obtained with very encouraging {approx}80% quantum efficiency, 57% fill factor, and 0.36 eV open-circuit voltage. The device performance degrades with decreasing bandgap (i.e., increasing lattice mismatch). We model the four-junction device efficiency vs. fourth junction bandgap to show that an 0.7-eV fourth-junction bandgap, while optimal if it could be achieved in practice, is not necessary; an 0.9-eV bandgap would still permit significant gains in multijunction cell efficiency while being easier to achieve than the lower-bandgap junction.

  9. Concentrating Photovoltaics (Presentation)

    SciTech Connect (OSTI)

    Kurtz, S.

    2009-01-20

    Solar is growing rapidly, and the concentrating photovoltaics industry-both high- and low-concentration cell approaches-may be ready to ramp production in 2009.

  10. Microscale solar cells for high concentration on polycrystalline Cu(In,Ga)Se2 Myriam Paire,1,2,3,4,a)

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    thin film solar cell material,7 and efficiencies over 20% were achieved recently. We study CIGS to decrease with illumination. The device described in this letter is a glass/Mo/CIGS/ CdS/ZnO solar cellMicroscale solar cells for high concentration on polycrystalline Cu(In,Ga)Se2 thin films Myriam

  11. Device characterization for design optimization of 4 junction inverted metamorphic concentrator solar cells

    SciTech Connect (OSTI)

    Geisz, John F.; France, Ryan M.; Steiner, Myles A.; Friedman, Daniel J.; García, Iván

    2014-09-26

    Quantitative electroluminescence (EL) and luminescent coupling (LC) analysis, along with more conventional characterization techniques, are combined to completely characterize the subcell JV curves within a fourjunction (4J) inverted metamorphic solar cell (IMM). The 4J performance under arbitrary spectral conditions can be predicted from these subcell JV curves. The internal radiative efficiency (IRE) of each junction has been determined as a function of current density from the external radiative efficiency using optical modeling, but this required the accurate determination of the individual junction current densities during the EL measurement as affected by LC. These measurement and analysis techniques can be applied to any multijunction solar cell. The 4J IMM solar cell used to illustrate these techniques showed excellent junction quality as exhibited by high IRE and a one-sun AM1.5D efficiency of 36.3%. This device operates up to 1000 suns without limitations due to any of the three tunnel junctions.

  12. Aalborg Universitet Estimation of CO concentration in high temperature PEM fuel cells using

    E-Print Network [OSTI]

    Berning, Torsten

    Aalborg University, Department of Energy Technology, Pontoppidanstræde 101, DK-9220, Aalborg, Denmark Abstract increasing amounts of renewable energy from wind, solar and wave sources. Although batteries are excellent of Fuel Cells: FDFC 2013. European Institute for Energy Research (EIFER). General rights Copyright

  13. Organic Solar Cells with Graded Exciton-dissociation Interfaces.................................................................................................................EN.1 Luminescent Solar Concentrators for Energy-harvesting in Displays ........

    E-Print Network [OSTI]

    Reif, Rafael

    Energy Organic Solar Cells with Graded Exciton-dissociation Interfaces.................................................................................................................EN.1 Luminescent Solar Concentrators for Energy-harvesting in Displays ...................................................................................EN.3 Nano-engineered Organic Solar-energy-harvesting System

  14. Micropower chemical fuel-to-electric conversion : a "regenerative flip" hydrogen concentration cell promising near carnot efficiency.

    SciTech Connect (OSTI)

    Wally, Karl

    2006-05-01

    Although battery technology is relatively mature, power sources continue to impose serious limitations for small, portable, mobile, or remote applications. A potentially attractive alternative to batteries is chemical fuel-to-electric conversion. Chemical fuels have volumetric energy densities 4 to 10 times those of batteries. However, realizing this advantage requires efficient chemical fuel-to-electric conversion. Direct electrochemical conversion would be the ideal, but, for most fuels, is generally not within the state-of-the-science. Next best, chemical-to-thermal-to-electric conversion can be attractive if efficiencies can be kept high. This small investigative project was an exploration into the feasibility of a novel hybrid (i.e., thermal-electrochemical) micropower converter of high theoretical performance whose demonstration was thought to be within near-term reach. The system is comprised of a hydrogen concentration electrochemical cell with physically identical hydrogen electrodes as anode and cathode, with each electrode connected to physically identical hydride beds each containing the same low-enthalpy-of-formation metal hydride. In operation, electrical power is generated by a hydrogen concentration differential across the electrochemical cell. This differential is established via coordinated heating and passive cooling of the corresponding hydride source and sink. Heating is provided by the exothermic combustion (i.e., either flame combustion or catalytic combustion) of a chemical fuel. Upon hydride source depletion, the role of source and sink are reversed, heating and cooling reversed, electrodes commutatively reversed, cell operation reversed, while power delivery continues unchanged. This 'regenerative flip' of source and sink hydride beds can be cycled continuously until all available heating fuel is consumed. Electricity is efficiently generated electrochemically, but hydrogen is not consumed, rather the hydrogen is regeneratively cycled as an electrochemical 'working fluid'.

  15. Plasmatic concentration of organochlorine lindane acts as metabolic disruptors in HepG2 liver cell line by inducing mitochondrial disorder

    SciTech Connect (OSTI)

    Benarbia, Mohammed el Amine; Macherel, David; Faure, Sébastien; Jacques, Caroline; Andriantsitohaina, Ramaroson; Malthièry, Yves

    2013-10-15

    Lindane (LD) is a persistent environmental pollutant that has been the subject of several toxicological studies. However, concentrations used in most of the reported studies were relatively higher than those found in the blood of the contaminated area residents and effects of low concentrations remain poorly investigated. Moreover, effects on cell metabolism and mitochondrial function of exposure to LD have received little attention. This study was designed to explore the effects of low concentrations of LD on cellular metabolism and mitochondrial function, using the hepatocarcinoma cell line HepG2. Cells were exposed to LD for 24, 48 and 72 h and different parameters linked with mitochondrial regulation and energy metabolism were analyzed. Despite having any impact on cellular viability, exposure to LD at plasmatic concentrations led to an increase of maximal respiratory capacity, complex I activity, intracellular ATP and NO release but decreased uncoupled respiration to ATP synthesis and medium lactate levels. In addition, LD exposure resulted in the upregulation of mitochondrial biogenesis genes. We suggest that, at plasmatic concentrations, LD acts as a metabolic disruptor through impaired mitochondrial function and regulation with an impact on cellular energetic metabolism. In addition, we propose that a cellular assay based on the analysis of mitochondria function, such as described here for LD, may be applicable for larger studies on the effects of low concentrations of xenobiotics, because of the exquisite sensitivity of this organelle. - Highlights: Our data clearly demonstrated in HepG2 cells that exposure at plasmatic low concentrations of LD were able to: • Impair mitochondrial function • Caused alteration on nucleo-mitochondrial cross-talk • Increase nitric oxide release and protein nitration • Impair cellular energetic metabolism and lipid accumulation.

  16. GaAs, AlGaAs and InGaP Tunnel Junctions for Multi-Junction Solar Cells Under Concentration: Resistance Study

    SciTech Connect (OSTI)

    Wheeldon, Jeffrey F.; Valdivia, Christopher E.; Walker, Alex; Kolhatkar, Gitanja; Hall, Trevor J.; Hinzer, Karin; Masson, Denis; Riel, Bruno; Fafard, Simon; Jaouad, Abdelatif; Turala, Artur; Ares, Richard; Aimez, Vincent

    2010-10-14

    The following four TJ designs, AlGaAs/AlGaAs, GaAs/GaAs, AlGaAs/InGaP and AlGaAs/GaAs are studied to determine minimum doping concentration to achieve a resistance of <10{sup -4} {omega}{center_dot}cm{sup 2} and a peak tunneling current suitable for MJ solar cells up to 1500-suns concentration (operating current of 21 A/cm{sup 2}). Experimentally calibrated numerical models are used to determine how the resistance changes as a function of doping concentration. The AlGaAs/GaAs TJ design is determined to require the least doping concentration to achieve the specified resistance and peak tunneling current, followed by the GaAs/GaAs, and AlGaAs/AlGaAs TJ designs. The AlGaAs/InGaP TJ design can only achieve resistances >5x10{sup -4} {omega}cm{sup 2}.

  17. Bisphenol A at a low concentration boosts mouse spermatogonial cell proliferation by inducing the G protein-coupled receptor 30 expression

    SciTech Connect (OSTI)

    Sheng, Zhi-Guo; Huang, Wei; Liu, Yu-Xiang; Zhu, Ben-Zhan

    2013-02-15

    Bisphenol A (BPA) is one of the most prevalent chemicals in daily-use materials, therefore, human exposure to BPA is ubiquitous. We found that low concentrations of BPA stimulate the spermatogonial GC-1 cells proliferation by G protein-coupled receptor 30 (GPR30)-mediated epidermal growth factor receptor (EGFR)-extracellular regulated kinase (ERK)-c-Fos pathway. However, through the same pathway GPR30 expression has been shown to be induced by EGF, an EGFR ligand. Thus, we want to know if low concentrations of BPA are able to induce the GPR30 expression and the possible mechanism(s) in GC-1 cells. By transient transfection with expression plasmids, 10{sup ?9} M BPA significantly transactivates the Gpr30-5?-flanking region through activating the GPR30, cGMP-dependent protein kinase (PKG), estrogen receptor-? (ER-?), and EFGR-ERK pathways. Furthermore, an activator protein-1 (AP-1) site located within this region is found to be responsible for the transactivation of BPA. Expectedly, through the same pathways, BPA significantly induces the gene and protein expression of GPR30. c-Fos is further observed to be strongly recruited to the AP-1 site in a chromatin immunoprecipitation assay and its dysfunction on the AP-1 site markedly suppresses the expression of GPR30, p-ERK1/2, p-Ser118-ER-? and cell proliferation by BPA. Our results demonstrate that a low-concentration BPA induces GPR30 expression through the GPR30-EFGR-ERK-c-Fos, ER-?, and PKG pathways, presumably boosting the cells proliferation via a regulatory loop. The present study provides a novel insight into the potential role of GPR30 in the initiation and progression of male germ cell cancer induced by environmentally relevant BPA. - Highlights: ? Low concentrations of BPA activate the PKG and GPR30-EFGR-ERK-ER-? pathways. ? Low concentrations of BPA activate the AP-1 site of Gpr30-5?-flanking region. ? Low concentrations of BPA induce the expression of GPR30 gene and protein. ? Low concentrations of BPA boost GC-1 cells proliferation via a regulatory loop.

  18. Enhancement of current collection in epitaxial lift-off InAs/GaAs quantum dot thin film solar cell and concentrated photovoltaic study

    SciTech Connect (OSTI)

    Sogabe, Tomah Shoji, Yasushi; Tamayo, Efrain; Okada, Yoshitaka; Mulder, Peter; Schermer, John

    2014-09-15

    We report the fabrication of a thin film InAs/GaAs quantum dot solar cell (QD cell) by applying epitaxial lift-off (ELO) approach to the GaAs substrate. We confirmed significant current collection enhancement (?0.91?mA/cm{sup 2}) in the ELO-InAs QD cell within the wavelength range of 700?nm–900?nm when compared to the ELO-GaAs control cell. This is almost six times of the sub-GaAs bandgap current collection (?0.16?mA/cm{sup 2}) from the wavelength range of 900?nm and beyond, we also confirmed the ELO induced resonance cavity effect was able to increase the solar cell efficiency by increasing both the short circuit current and open voltage. The electric field intensity of the resonance cavity formed in the ELO film between the Au back reflector and the GaAs front contact layer was analyzed in detail by finite-differential time-domain (FDTD) simulation. We found that the calculated current collection enhancement within the wavelength range of 700?nm–900?nm was strongly influenced by the size and shape of InAs QD. In addition, we performed concentrated light photovoltaic study and analyzed the effect of intermediate states on the open voltage under varied concentrated light intensity for the ELO-InAs QD cell.

  19. Germanium subcells for multijunction GaInP/GaInAs/Ge solar cells

    SciTech Connect (OSTI)

    Kalyuzhnyy, N. A.; Gudovskikh, A. S.; Evstropov, V. V.; Lantratov, V. M.; Mintairov, S. A.; Timoshina, N. Kh.; Shvarts, M. Z.; Andreev, V. M.

    2010-11-15

    Photovoltaic converters based on n-GaInP/n-p-Ge heterostructures grown by the OMVPE under different conditions of formation of the p-n junction are studied. The heterostructures are intended for use as narrow-gap subcells of the GaInP/GaInAs/Ge three-junction solar cells. It is shown that, in Ge p-tn junctions, along with the diffusion mechanism, the tunneling mechanism of the current flow exists; therefore, the two-diode electrical equivalent circuit of the Ge p-n junction is used. The diode parameters are determined for both mechanisms from the analysis of both dark and 'light' current-voltage dependences. It is shown that the elimination of the component of the tunneling current allows one to increase the efficiency of the Ge subcell by {approx}1% with conversion of nonconcentrated solar radiation. The influence of the tunneling current on the efficiency of the Ge-based devices can be in practice reduced to zero at photogenerated current density of {approx}1.5 A/cm{sup 2} due to the use of the concentrated solar radiation.

  20. Proton Transfer and Proton Concentrations in Protonated Nafion Fuel Cell Membranes D. B. Spry and M. D. Fayer*

    E-Print Network [OSTI]

    Fayer, Michael D.

    electrolyte fuel cells (PEFCs).1 In a PEFC, hydrogen is oxidized at the anode to generate a supply to the cathode, while preventing the passage of the reactant gases, is essential for the PEFC's operation. Nafion

  1. Reducing pumping energy by using different flow rates of high and low concentration solutions in reverse electrodialysis cells

    E-Print Network [OSTI]

    Reducing pumping energy by using different flow rates of high and low concentration solutions Keywords: Salinity gradient energy RED Renewable energy production a b s t r a c t Energy use for pumping to reduce the energy needed for pumping, electrical performance and hydrodynamic power losses in a RED stack

  2. Photovoltaic solar concentrator

    DOE Patents [OSTI]

    Nielson, Gregory N.; Okandan, Murat; Resnick, Paul J.; Cruz-Campa, Jose Luis

    2012-12-11

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  3. An inverted AlGaAs/GaAs patterned-Ge tunnel junction cascade concentrator solar cell

    SciTech Connect (OSTI)

    Venkatasubramanian, R. )

    1993-01-01

    This report describes work to develop inverted-grown Al[sub 0.34]Ga[sub 0.66]As/GaAs cascades. Several significant developments are reported on as follows: (1) The AM1.5 1-sun total-area efficiency of the top Al[sub 0.34]Ga[sub 0.66]As cell for the cascade was improved from 11.3% to 13.2% (NREL measurement [total-area]). (2) The cycled'' organometallic vapor phase epitaxy growth (OMVPE) was studied in detail utilizing a combination of characterization techniques including Hall-data, photoluminescence, and secondary ion mass spectroscopy. (3) A technique called eutectic-metal-bonding (EMB) was developed by strain-free mounting of thin GaAs-AlGaAs films (based on lattice-matched growth on Ge substrates and selective plasma etching of Ge substrates) onto Si carrier substrates. Minority-carrier lifetime in an EMB GaAs double-heterostructure was measured as high as 103 nsec, the highest lifetime report for a freestanding GaAs thin film. (4) A thin-film, inverted-grown GaAs cell with a 1-sun AM1.5 active-area efficiency of 20.3% was obtained. This cell was eutectic-metal-bonded onto Si. (5) A thin-film inverted-grown, Al[sub 0.34]Ga[sub 0.66]As/GaAs cascade with AM1.5 efficiency of 19.9% and 21% at 1-sun and 7-suns, respectively, was obtained. This represents an important milestone in the development of an AlGaAs/GaAs cascade by OMVPE utilizing a tunnel interconnect and demonstrates a proof-of-concept for the inverted-growth approach.

  4. Concentrator Photovoltaic System Basics | Department of Energy

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

    cells. However, challenges exist for concentrators. First, the required concentrating optics are significantly more expensive than the simple covers needed for flat-plate solar...

  5. Soret Effect Study on High-Pressure CO2-Water Solutions Using UV-Raman Spectroscopy and a Concentric-Tube Optical Cell

    SciTech Connect (OSTI)

    Windisch, Charles F.; McGrail, B. Peter; Maupin, Gary D.

    2012-01-01

    Spatially resolved deep-UV Raman spectroscopy was applied to solutions of CO2 and H2O (or D2O), which were subject to a temperature gradient in a thermally regulated high-pressure concentric-tube Raman cell in an attempt to measure a Soret effect in the vicinity of the critical point of CO2. Although Raman spectra of solutions of CO2 dissolved in D2O at 10 MPa and temperatures near the critical point of CO2 had adequate signal-to-noise and spatial resolution to observe a Soret effect with a Soret coefficient with magnitude of |ST| > 0.03, no evidence for an effect of this size was obtained for applied temperature gradients up to 19oC. The presence of 1 M NaCl did not make a difference. In contrast, the concentration of CO2 dissolved in H2O was shown to vary significantly across the temperature gradient when excess CO2 was present, but the results could be explained simply by the variation in CO2 solubility over the temperature range and not to kinetic factors. For mixtures of D2O dissolved in scCO2 at 10 MPa and temperatures close to the critical point of CO2, the Raman peaks for H2O were too weak to measure with confidence even at the limit of D2O solubility.

  6. Solar Junction Develops World Record Setting Concentrated Photovoltaic...

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

    Solar Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell Solar Junction Develops World Record Setting Concentrated Photovoltaic Solar Cell April 18, 2013 -...

  7. Planar micro-optic solar concentration

    E-Print Network [OSTI]

    Karp, Jason Harris

    2010-01-01

    1 Introduction 1.1. Solar Photovoltaics Semiconductingmulti-junction photovoltaics, solar beamsplitting 1.Concentrator Photovoltaics Multijunction solar cells were

  8. Entrepreneurship Concentration

    E-Print Network [OSTI]

    Massachusetts at Lowell, University of

    The Entrepreneurship Concentration The Manning School of Business www.uml.edu/management Who We Are, management, management information systems, marketing and supply chain and operations management we provide business. The experience I had in the classroom was wonderful and the professors teach with real life

  9. Heat Pipe Performance Enhancement with Binary Mixture Fluids that Exhibit Strong Concentration Marangoni Effects

    E-Print Network [OSTI]

    Armijo, Kenneth Miguel

    2011-01-01

    2004, “Cooling of photovoltaic cells under concentratedSolar cells and optics for photovoltaic concentration”, Adamelectric performance of a photovoltaic cells by cooling and

  10. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    glass-?lms. Solar Energy Materials and Solar Cells, 33(4):concentrator. Solar Energy Materials and Solar Cells, 93(8):concentrator. Solar Energy Materials and Solar Cells, 91(1):

  11. National solar technology roadmap: Concentrator PV

    SciTech Connect (OSTI)

    Friedman, Dan

    2007-06-01

    This roadmap addresses high-concentration (>10x) photovoltaic (PV) systems, incorporating high-efficiency III-V or silicon cells, trackers, and reflective or refractive optics.

  12. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    for generating low-cost solar power, LSC development facesand lowering the cost, luminescent solar concentrations (cells. Using solar concentrators, the cost of solar energy

  13. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    1.1 Solar Energy . . . . . . . . .glass-?lms. Solar Energy Materials and Solar Cells, 33(4):concentrator. Solar Energy Materials and Solar Cells, 93(8):

  14. Tissue transglutaminase treatment leads to concentration-dependent changes in dendritic cell phenotype - implications for the role of transglutaminase in coeliac disease

    E-Print Network [OSTI]

    Dalleywater, William J.; Chau, David Y. S.; Ghaemmaghami, Amir M.

    2012-04-16

    Leukoc Biol 2009, 86:567-572. 28. Zemskov EA, Janiak A, Hang J, Waghray A, Belkin AM: The role of tissue transglutaminase in cell-matrix interactions. Front Biosci 2006, 11:1057-1076. 29. Brown KA, Bedford P, Macey M, McCarthy DA, Leroy F, Vora AJ, Stagg...

  15. BORON CONCENTRATION MEASUREMENTS AT THE I/P INTERFACE IN NIP A-SI SOLAR CELLS B.B. Van Aken1

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    , bulk plasmon energy using EELS 1 INTRODUCTION Roll-to-roll production of thin film Si solar cells has Solar Energy, P.O. Box 1, NL-1755 ZG Petten, the Netherlands 2 Center for Electron Nanoscopy, Technical, Forschungszentrum Jülich, D-52425 Jülich, Germany 4 CEA-Leti, MINATEC Campus, 17 rue des Martyrs, FR-38054 Grenoble

  16. Planar photovoltaic solar concentrator module

    DOE Patents [OSTI]

    Chiang, C.J.

    1992-12-01

    A planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor. 5 figs.

  17. Planar photovoltaic solar concentrator module

    DOE Patents [OSTI]

    Chiang, Clement J. (New Brunswick, NJ)

    1992-01-01

    A planar photovoltaic concentrator module for producing an electrical signal from incident solar radiation includes an electrically insulating housing having a front wall, an opposing back wall and a hollow interior. A solar cell having electrical terminals is positioned within the interior of the housing. A planar conductor is connected with a terminal of the solar cell of the same polarity. A lens forming the front wall of the housing is operable to direct solar radiation incident to the lens into the interior of the housing. A refractive optical element in contact with the solar cell and facing the lens receives the solar radiation directed into the interior of the housing by the lens and directs the solar radiation to the solar cell to cause the solar cell to generate an electrical signal. An electrically conductive planar member is positioned in the housing to rest on the housing back wall in supporting relation with the solar cell terminal of opposite polarity. The planar member is operable to dissipate heat radiated by the solar cell as the solar cell generates an electrical signal and further forms a solar cell conductor connected with the solar cell terminal to permit the electrical signal generated by the solar cell to be measured between the planar member and the conductor.

  18. High efficiency and high concentration in photovoltaics

    SciTech Connect (OSTI)

    Yamaguchi, Masafumi; Luque, A.

    1999-10-01

    In this paper, the authors present the state-of-the-art of multijunction solar cells and the future prospects of this technology. Their use in terrestrial applications will likely be for concentrators operating at very high concentrations. Some trends are also discussed and the authors present a cost calculation showing that highly efficient cells under very high concentration would be able to produce electricity at costs competitive with electricity generation costs for some utilities.

  19. Determination of the electrical conductivity and the elctroosmotic transfer in the concentrated dispersions on the basis of the cell theory of the electroosmosis

    E-Print Network [OSTI]

    D. Gulo; O. Alexejev

    1999-03-12

    Theoretical calculations of the electrical conductivity and electroosmotic transfer as functions of the disperse phase volume fraction and non-dissolving boundary layer thickness were provided on the basis of the cell theory of electroosmosis for the limiting case of large degree of electric double layers overlapping in interparticle space. The obtained results are in qualitative agreement with the experimental data and describe the main features of the latter

  20. An inverted AlGaAs/GaAs patterned-Ge tunnel junction cascade concentrator solar cell. Final subcontract report, 1 January 1991--31 August 1992

    SciTech Connect (OSTI)

    Venkatasubramanian, R.

    1993-01-01

    This report describes work to develop inverted-grown Al{sub 0.34}Ga{sub 0.66}As/GaAs cascades. Several significant developments are reported on as follows: (1) The AM1.5 1-sun total-area efficiency of the top Al{sub 0.34}Ga{sub 0.66}As cell for the cascade was improved from 11.3% to 13.2% (NREL measurement [total-area]). (2) The ``cycled`` organometallic vapor phase epitaxy growth (OMVPE) was studied in detail utilizing a combination of characterization techniques including Hall-data, photoluminescence, and secondary ion mass spectroscopy. (3) A technique called eutectic-metal-bonding (EMB) was developed by strain-free mounting of thin GaAs-AlGaAs films (based on lattice-matched growth on Ge substrates and selective plasma etching of Ge substrates) onto Si carrier substrates. Minority-carrier lifetime in an EMB GaAs double-heterostructure was measured as high as 103 nsec, the highest lifetime report for a freestanding GaAs thin film. (4) A thin-film, inverted-grown GaAs cell with a 1-sun AM1.5 active-area efficiency of 20.3% was obtained. This cell was eutectic-metal-bonded onto Si. (5) A thin-film inverted-grown, Al{sub 0.34}Ga{sub 0.66}As/GaAs cascade with AM1.5 efficiency of 19.9% and 21% at 1-sun and 7-suns, respectively, was obtained. This represents an important milestone in the development of an AlGaAs/GaAs cascade by OMVPE utilizing a tunnel interconnect and demonstrates a proof-of-concept for the inverted-growth approach.

  1. Concentrating Solar Power Forum Concentrating Photovoltaics (Presentation)

    SciTech Connect (OSTI)

    Kurtz, S.

    2008-05-06

    This presentation's summaries: a convenient truth, comparison of three concentrator technologies, value of high efficiency, and status of industry.

  2. Planar micro-optic solar concentration

    E-Print Network [OSTI]

    Karp, Jason Harris

    2010-01-01

    improvements over first- Figure 3.14 Second-generation concentrator under test (a). A multijunction solar cellimprovements through material science and novel cell architectures [7][8][9]. Figure 1.1 Multijunction solar

  3. Linear Concentrator System Basics for Concentrating Solar Power...

    Office of Environmental Management (EM)

    Linear Concentrator System Basics for Concentrating Solar Power Linear Concentrator System Basics for Concentrating Solar Power August 20, 2013 - 4:45pm Addthis Photo of numerous...

  4. Concentrating Solar Power

    SciTech Connect (OSTI)

    Not Available

    2008-09-01

    Summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts within its concentrating solar power subprogram.

  5. TOPCAT Solar Cell Alignment & Energy Concentration Technology

    Energy Innovation Portal (Marketing Summaries) [EERE]

    2013-03-12

    This technology is a new technique for parabolic trough mirror alignment based on the use of an innovative Theoretical Overlay Photographic (TOP) approach. It is a variation of current methods used on parabolic dish systems and involves overlay of theoretical images of the Heat Collection Element (HCE) in the mirrors onto carefully surveyed photographic images and adjustment of mirror alignment until they match....

  6. Photovoltaic solar concentrator

    DOE Patents [OSTI]

    Nielson, Gregory N.; Cruz-Campa, Jose Luis; Okandan, Murat; Resnick, Paul J.; Sanchez, Carlos Anthony; Clews, Peggy J.; Gupta, Vipin P.

    2015-09-08

    A process including forming a photovoltaic solar cell on a substrate, the photovoltaic solar cell comprising an anchor positioned between the photovoltaic solar cell and the substrate to suspend the photovoltaic solar cell from the substrate. A surface of the photovoltaic solar cell opposite the substrate is attached to a receiving substrate. The receiving substrate may be bonded to the photovoltaic solar cell using an adhesive force or a metal connecting member. The photovoltaic solar cell is then detached from the substrate by lifting the receiving substrate having the photovoltaic solar cell attached thereto and severing the anchor connecting the photovoltaic solar cell to the substrate. Depending upon the type of receiving substrate used, the photovoltaic solar cell may be removed from the receiving substrate or remain on the receiving substrate for use in the final product.

  7. Solar Junction Develops World Record Setting Concentrated Photovoltaic...

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

    the company's concentrated photovoltaic technology that also set a world record for conversion efficiency. The company's cell technology relies on inexpensive lenses to magnify...

  8. Scattering Solar Thermal Concentrators

    Office of Environmental Management (EM)

    sunshot DOEGO-102012-3669 * September 2012 MOTIVATION All thermal concentrating solar power (CSP) systems use solar tracking, which involves moving large mirror surfaces...

  9. Concentrated Solar Thermoelectric Power

    Broader source: Energy.gov [DOE]

    This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23–25, 2013 near Phoenix, Arizona.

  10. Concentrating Solar Power

    SciTech Connect (OSTI)

    Solar Energy Technologies Program

    2010-09-28

    The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts within its concentrating solar power subprogram.

  11. Concentrated Thermoelectric Power

    Broader source: Energy.gov [DOE]

    This fact sheet describes a concentrated solar hydroelectric power project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by MIT, is working to demonstrate concentrating solar thermoelectric generators with >10% solar-to-electrical energy conversion efficiency while limiting optical concentration to less than a factor of 10 and potentially less than 4. When combined with thermal storage, CSTEGs have the potential to provide electricity day and night using no moving parts at both the utility and distributed scale.

  12. Concentrating Solar Power Basics

    Office of Energy Efficiency and Renewable Energy (EERE)

    Concentrating solar power (CSP) technologies use mirrors to reflect and concentrate sunlight onto receivers that collect solar energy and convert it to heat. This thermal energy can then be used to produce electricity via a steam turbine or heat engine that drives a generator.

  13. Concentration in Green Design

    E-Print Network [OSTI]

    Shewchuk, Jonathan

    , energy, infrastructure or transport. Participants in this specialization area work closely with the GreenConcentration in Green Design Research and Education Opportunities Carnegie Mellon University Civil and Environmental Engineering www.ce.cmu.edu M.S. Concentration Green Design - Course Only Track As an extension

  14. Concentrating photovoltaic solar panel

    DOE Patents [OSTI]

    Cashion, Steven A; Bowser, Michael R; Farrelly, Mark B; Hines, Braden E; Holmes, Howard C; Johnson, Jr., Richard L; Russell, Richard J; Turk, Michael F

    2014-04-15

    The present invention relates to photovoltaic power systems, photovoltaic concentrator modules, and related methods. In particular, the present invention features concentrator modules having interior points of attachment for an articulating mechanism and/or an articulating mechanism that has a unique arrangement of chassis members so as to isolate bending, etc. from being transferred among the chassis members. The present invention also features adjustable solar panel mounting features and/or mounting features with two or more degrees of freedom. The present invention also features a mechanical fastener for secondary optics in a concentrator module.

  15. Scattering Solar Thermal Concentrators

    Broader source: Energy.gov [DOE]

    "This fact sheet describes a scattering solar thermal concentrators project awarded under the DOE's 2012 SunShot Concentrating Solar Power R&D award program. The team, led by the Pennsylvania State University, is working to demonstrate a new, scattering-based approach to concentrating sunlight that aims to improve the overall performance and reliability of the collector field. The research team aims to show that scattering solar thermal collectors are capable of achieving optical performance equal to state-of-the-art parabolic trough systems, but with the added benefits of immunity to wind-load tracking error, more efficient land use, and utilization of stationary receivers."

  16. Health, Medicine and Aging Concentration Concentrations in Sociology

    E-Print Network [OSTI]

    Turc, Catalin

    Sociology Health, Medicine and Aging Concentration Concentrations in Sociology Students majoring. The 4 concentrations are: · Crime, Law and Justice · Health, Medicine and Aging · Gender, Work and Family · Social Inequality Health, Medicine and Aging Concentration Undergraduate students majoring

  17. Water Sample Concentrator

    ScienceCinema (OSTI)

    Idaho National Laboratory

    2010-01-08

    Automated portable device that concentrates and packages a sample of suspected contaminated water for safe, efficient transport to a qualified analytical laboratory. This technology will help safeguard against pathogen contamination or chemical and biolog

  18. Organic photovoltaics and concentrators

    E-Print Network [OSTI]

    Mapel, Jonathan King

    2008-01-01

    The separation of light harvesting and charge generation offers several advantages in the design of organic photovoltaics and organic solar concentrators for the ultimate end goal of achieving a lower cost solar electric ...

  19. Joined concentric tubes

    DOE Patents [OSTI]

    DeJonghe, Lutgard; Jacobson, Craig; Tucker, Michael; Visco, Steven

    2013-01-01

    Tubular objects having two or more concentric layers that have different properties are joined to one another during their manufacture primarily by compressive and friction forces generated by shrinkage during sintering and possibly mechanical interlocking. It is not necessary for the concentric tubes to display adhesive-, chemical- or sinter-bonding to each other in order to achieve a strong bond. This facilitates joining of dissimilar materials, such as ceramics and metals.

  20. Nonimaging light concentrator with uniform irradiance

    DOE Patents [OSTI]

    Winston, Roland (Chicago, IL); Gee, Randy C. (Arvada, CO)

    2003-04-01

    A nonimaging light concentrator system including a primary collector of light, an optical mixer disposed near the focal zone for collecting light from the primary collector, the optical mixer having a transparent entrance aperture, an internally reflective housing for substantially total internal reflection of light, a transparent exit aperture and an array of photovoltaic cells disposed near the transparent exit aperture.

  1. Biomedical Engineering Graduate Concentration Fall 2014 Biotechnology

    E-Print Network [OSTI]

    Eustice, Ryan

    Biomedical Engineering Graduate Concentration ­ Fall 2014 Biotechnology Advisor: Michael Mayer, Ph.D. BIOTECHNOLOGY (select one course): BIOMEDE 410 Design and Applications of Biomaterials (3) (I) BIOMEDE 556 Cellular and Molecular Biomechanics (3) (I) BIOMEDE 574 Cells in Their Environment (3) (II) BIOMEDE 616

  2. Airborne agent concentration analysis

    DOE Patents [OSTI]

    Gelbard, Fred

    2004-02-03

    A method and system for inferring airborne contaminant concentrations in rooms without contaminant sensors, based on data collected by contaminant sensors in other rooms of a building, using known airflow interconnectivity data. The method solves a least squares problem that minimizes the difference between measured and predicted contaminant sensor concentrations with respect to an unknown contaminant release time. Solutions are constrained to providing non-negative initial contaminant concentrations in all rooms. The method can be used to identify a near-optimal distribution of sensors within the building, when then number of available sensors is less than the total number of rooms. This is achieved by having a system-sensor matrix that is non-singular, and by selecting that distribution which yields the lowest condition number of all the distributions considered. The method can predict one or more contaminant initial release points from the collected data.

  3. The Marketing Concentration

    E-Print Network [OSTI]

    Massachusetts at Lowell, University of

    The Marketing Concentration The Manning School of Business www.uml.edu/management Who We Are, management, management information systems, marketing and supply chain and operations management we provide education possible." -- Andy Hwang Marketing Major "I chose UMass Lowell because of its high level

  4. environmental health Understanding Concentrated

    E-Print Network [OSTI]

    environmental health Understanding Concentrated Animal Feeding Operations and Their Impact of Health Editor Mark Schultz, MEd Grants Administrator/Technical Writer National Association of Local Boards of Health ©2010 National Association of Local Boards of Health 1840 East Gypsy Lane Road Bowling

  5. Catalysts get concentrated attention

    SciTech Connect (OSTI)

    Bruch, H.W.

    1989-02-27

    At the most recent National Petroleum Refiners Association annual question and answer session on refining and petrochemical technology, refiners concentrated heavily on questions pertaining to modern catalyst technology and its applications and operating experiences, including: fluid catalytic cracking, hydrocracking, hydrotreating, and catalytic reforming.

  6. Scattering Solar Thermal Concentrators

    SciTech Connect (OSTI)

    Giebink, Noel C.

    2015-01-31

    This program set out to explore a scattering-based approach to concentrate sunlight with the aim of improving collector field reliability and of eliminating wind loading and gross mechanical movement through the use of a stationary collection optic. The approach is based on scattering sunlight from the focal point of a fixed collection optic into the confined modes of a sliding planar waveguide, where it is transported to stationary tubular heat transfer elements located at the edges. Optical design for the first stage of solar concentration, which entails focusing sunlight within a plane over a wide range of incidence angles (>120 degree full field of view) at fixed tilt, led to the development of a new, folded-path collection optic that dramatically out-performs the current state-of-the-art in scattering concentration. Rigorous optical simulation and experimental testing of this collection optic have validated its performance. In the course of this work, we also identified an opportunity for concentrating photovoltaics involving the use of high efficiency microcells made in collaboration with partners at the University of Illinois. This opportunity exploited the same collection optic design as used for the scattering solar thermal concentrator and was therefore pursued in parallel. This system was experimentally demonstrated to achieve >200x optical concentration with >70% optical efficiency over a full day by tracking with <1 cm of lateral movement at fixed latitude tilt. The entire scattering concentrator waveguide optical system has been simulated, tested, and assembled at small scale to verify ray tracing models. These models were subsequently used to predict the full system optical performance at larger, deployment scale ranging up to >1 meter aperture width. Simulations at an aperture widths less than approximately 0.5 m with geometric gains ~100x predict an overall optical efficiency in the range 60-70% for angles up to 50 degrees from normal. However, the concentrator optical efficiency was found to decrease significantly with increasing aperture width beyond 0.5 m due to parasitic waveguide out-coupling loss and low-level absorption that become dominant at larger scale. A heat transfer model was subsequently implemented to predict collector fluid heat gain and outlet temperature as a function of flow rate using the optical model as a flux input. It was found that the aperture width size limitation imposed by the optical efficiency characteristics of the waveguide limits the absolute optical power delivered to the heat transfer element per unit length. As compared to state-of-the-art parabolic trough CPV system aperture widths approaching 5 m, this limitation leads to an approximate factor of order of magnitude increase in heat transfer tube length to achieve the same heat transfer fluid outlet temperature. The conclusion of this work is that scattering solar thermal concentration cannot be implemented at the scale and efficiency required to compete with the performance of current parabolic trough CSP systems. Applied within the alternate context of CPV, however, the results of this work have likely opened up a transformative new path that enables quasi-static, high efficiency CPV to be implemented on rooftops in the form factor of traditional fixed-panel photovoltaics.

  7. Concentrating Solar Power (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-10-01

    Concentrating Solar Power (CSP) offers a utility-scale, firm, dispatchable renewable energy option that can help meet the nation's goal of making solar energy cost competitive with other energy sources by the end of the decade. The DOE SunShot Initiative is a collaborative national initiative to make solar energy technologies cost-competitive with other forms of energy by reducing the cost of solar energy systems by about 75% by the end of the decade. Reducing the total installed cost for utility-scale solar electricity to roughly 6 cents per kilowatt hour without subsidies will result in rapid, large-scale adoption of solar electricity across the United States. Reaching this goal will re-establish American technological leadership, improve the nation's energy security, and strengthen U.S. economic competitiveness in the global clean energy race. SunShot will work to bring down the full cost of solar - including the costs of solar cells and installation by focusing on four main pillars: (1) Technologies for solar cells and arrays that convert sunlight to energy; (2) Electronics that optimize the performance of the installation; (3) Improvements in the efficiency of solar manufacturing processes; and (4) Installation, design, and permitting for solar energy systems.

  8. Multijunction Photovoltaic Technologies for High-Performance Concentrators: Preprint

    SciTech Connect (OSTI)

    McConnell, R.; Symko-Davies, M.

    2006-05-01

    Multijunction solar cells provide high-performance technology pathways leading to potentially low-cost electricity generated from concentrated sunlight. The National Center for Photovoltaics at the National Renewable Energy Laboratory has funded different III-V multijunction solar cell technologies and various solar concentration approaches. Within this group of projects, III-V solar cell efficiencies of 41% are close at hand and will likely be reported in these conference proceedings. Companies with well-developed solar concentrator structures foresee installed system costs of $3/watt--half of today's costs--within the next 2 to 5 years as these high-efficiency photovoltaic technologies are incorporated into their concentrator photovoltaic systems. These technology improvements are timely as new large-scale multi-megawatt markets, appropriate for high performance PV concentrators, open around the world.

  9. Multijunction Photovoltaic Technologies for High-Performance Concentrators

    SciTech Connect (OSTI)

    McConnell, R.; Symko-Davies, M.

    2006-01-01

    Multijunction solar cells provide high-performance technology pathways leading to potentially low-cost electricity generated from concentrated sunlight. The National Center for Photovoltaics at the National Renewable Energy Laboratory has funded different III-V multijunction solar cell technologies and various solar concentration approaches. Within this group of projects, III-V solar cell efficiencies of 41% are close at hand and will likely be reported in these conference proceedings. Companies with well-developed solar concentrator structures foresee installed system costs of $3/watt--half of today's costs--within the next 2 to 5 years as these high-efficiency photovoltaic technologies are incorporated into their concentrator photovoltaic systems. These technology improvements are timely as new large-scale multi-megawatt markets, appropriate for high performance PV concentrators, open around the world.

  10. Concentrated Solar Thermoelectric Power

    SciTech Connect (OSTI)

    Chen, Gang; Ren, Zhifeng

    2015-07-09

    The goal of this project is to demonstrate in the lab that solar thermoelectric generators (STEGs) can exceed 10% solar-to-electricity efficiency, and STEGs can be integrated with phase-change materials (PCM) for thermal storage, providing operation beyond daylight hours. This project achieved significant progress in many tasks necessary to achieving the overall project goals. An accurate Themoelectric Generator (TEG) model was developed, which included realistic treatment of contact materials, contact resistances and radiative losses. In terms of fabricating physical TEGs, high performance contact materials for skutterudite TE segments were developed, along with brazing and soldering methods to assemble segmented TEGs. Accurate measurement systems for determining device performance (in addition to just TE material performance) were built for this project and used to characterize our TEGs. From the optical components’ side, a spectrally selective cermet surface was developed with high solar absorptance and low thermal emittance, with thermal stability at high temperature. A measurement technique was also developed to determine absorptance and total hemispherical emittance at high temperature, and was used to characterize the fabricated spectrally selective surfaces. In addition, a novel reflective cavity was designed to reduce radiative absorber losses and achieve high receiver efficiency at low concentration ratios. A prototype cavity demonstrated that large reductions in radiative losses were possible through this technique. For the overall concentrating STEG system, a number of devices were fabricated and tested in a custom built test platform to characterize their efficiency performance. Additionally, testing was performed with integration of PCM thermal storage, and the storage time of the lab scale system was evaluated. Our latest testing results showed a STEG efficiency of 9.6%, indicating promising potential for high performance concentrated STEGs.

  11. Current Status of Concentrator Photovoltaic (CPV) Technology

    SciTech Connect (OSTI)

    Philipps, S. P.; Bett, A. W.; Horowitz, K.; Kurtz, S.

    2015-01-01

    This report describes the current status of the market and technology for concentrator photovoltaic (CPV) cells and modules. Significant progress in CPV has been achieved, including record efficiencies for modules (36.7%) and cells (46%), as well as growth of large field installations in recent years. CPV technology may also have the potential to be cost-competitive on a levelized cost of energy (LCOE) basis in regions of high direct normal irradiance (DNI). The study includes an overview of all installations larger than 1 MW, information on companies currently active in the CPV field, efficiency data, and estimates of the LCOE in different scenarios.

  12. Optimized Designs and Materials for Nanostructure Based Solar Cells

    E-Print Network [OSTI]

    Shao, Qinghui

    2009-01-01

    for concentrator photovoltaic cells (CPV) is 100 K – 200 KConcentrated Photovoltaic (CPV) cells have been demonstratedimplementing photovoltaic and photochemical cells on large

  13. Optical oxygen concentration monitor

    DOE Patents [OSTI]

    Kebabian, P.

    1997-07-22

    A system for measuring and monitoring the concentration of oxygen uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to one of oxygen`s A-band absorption lines. In a preferred embodiment, the argon line is split into sets of components of shorter and longer wavelengths by a magnetic field of approximately 2,000 Gauss that is parallel to the light propagation from the lamp. The longer wavelength components are centered on an absorption line of oxygen and thus readily absorbed, and the shorter wavelength components are moved away from that line and minimally absorbed. A polarization modulator alternately selects the set of the longer wavelength, or upshifted, components or the set of the shorter wavelength, or downshifted, components and passes the selected set to an environment of interest. After transmission over a path through that environment, the transmitted optical flux of the argon line varies as a result of the differential absorption. The system then determines the concentration of oxygen in the environment based on the changes in the transmitted optical flux between the two sets of components. In alternative embodiments modulation is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to either the emitting plasma of the lamp or the environment of interest. 4 figs.

  14. Optical oxygen concentration monitor

    DOE Patents [OSTI]

    Kebabian, Paul (Acton, MA)

    1997-01-01

    A system for measuring and monitoring the concentration of oxygen uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to one of oxygen's A-band absorption lines. In a preferred embodiment, the argon line is split into sets of components of shorter and longer wavelengths by a magnetic field of approximately 2000 Gauss that is parallel to the light propagation from the lamp. The longer wavelength components are centered on an absorption line of oxygen and thus readily absorbed, and the shorter wavelength components are moved away from that line and minimally absorbed. A polarization modulator alternately selects the set of the longer wavelength, or upshifted, components or the set of the shorter wavelength, or downshifted, components and passes the selected set to an environment of interest. After transmission over a path through that environment, the transmitted optical flux of the argon line varies as a result of the differential absorption. The system then determines the concentration of oxygen in the environment based on the changes in the transmitted optical flux between the two sets of components. In alternative embodiments modulation is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to either the emitting plasma of the lamp or the environment of interest.

  15. Photovoltaic concentrator assembly with optically active cover

    DOE Patents [OSTI]

    Plesniak, Adam P

    2014-01-21

    A photovoltaic concentrator assembly that includes a housing that defines an internal volume and includes a rim, wherein the rim defines an opening into the internal volume, a photovoltaic cell positioned in the internal volume, and an optical element that includes an optically active body and a flange extending outward from the body, wherein the flange is sealingly engaged with the rim of the housing to enclose the internal volume.

  16. AIP ADVANCES 5, 097150 (2015) Buffer layer between a planar optical concentrator

    E-Print Network [OSTI]

    2015-01-01

    the fabrica- tion costs without significantly reducing the efficiency of the solar cell. Both crystallineAIP ADVANCES 5, 097150 (2015) Buffer layer between a planar optical concentrator and a solar cell optical concentrator and a photovoltaic solar cell was theoretically investigated. The substitution

  17. Department of Electrical Engineering A Novel Refracting Concentration

    E-Print Network [OSTI]

    Su, Xiao

    Lili He Department of Electrical Engineering A Novel Refracting Concentration Solar System #12 #12;1. Project Description A. Introduction · Si crystalline solar cell was initially discovered five decades. · Applications of solar cells are now an important part of our daily lives, ranging from

  18. Detecting concentration changes with cooperative receptors

    E-Print Network [OSTI]

    Bo, Stefano

    2015-01-01

    Cells constantly need to monitor the state of the environment to detect changes and timely respond. The detection of concentration changes of a ligand by a set of receptors can be cast as a problem of hypothesis testing, and the cell viewed as a Neyman-Pearson detector. Within this framework, we investigate the role of receptor cooperativity in improving the cell's ability to detect changes. We find that cooperativity decreases the probability of missing an occurred change. This becomes especially beneficial when difficult detections have to be made. Concerning the influence of cooperativity on how fast a desired detection power is achieved, we find in general that there is an optimal value at finite levels of cooperation, even though easy discrimination tasks can be performed more rapidly by noncooperative receptors.

  19. Concentric tube support assembly

    DOE Patents [OSTI]

    Rubio, Mark F.; Glessner, John C.

    2012-09-04

    An assembly (45) includes a plurality of separate pie-shaped segments (72) forming a disk (70) around a central region (48) for retaining a plurality of tubes (46) in a concentrically spaced apart configuration. Each segment includes a support member (94) radially extending along an upstream face (96) of the segment and a plurality of annularly curved support arms (98) transversely attached to the support member and radially spaced apart from one another away from the central region for receiving respective upstream end portions of the tubes in arc-shaped spaces (100) between the arms. Each segment also includes a radial passageway (102) formed in the support member for receiving a fluid segment portion (106) and a plurality of annular passageways (104) formed in the support arms for receiving respective arm portions (108) of the fluid segment portion from the radial passageway and for conducting the respective arm portions into corresponding annular spaces (47) formed between the tubes retained by the disk.

  20. Engineering the optical properties of luminescent solar concentrators at the molecular scale

    E-Print Network [OSTI]

    Mulder, Carlijn Lucinde

    2012-01-01

    Luminescent Solar Concentrators (LSCs) concentrate solar radiation onto photovoltaic (PV) cells using an inexpensive collector plate to absorb incoming photons and waveguide fluorescently re-emitted photons to PVs at the ...

  1. Markets for concentrating solar power

    SciTech Connect (OSTI)

    Not Available

    1998-04-01

    The report describes the markets for concentrating solar power. As concentrating solar power technologies advance into the early stages of commercialization, their economic potential becomes more sharply defined and increasingly tangible.

  2. SEDIMENT CONCENTRATION BELOW FREE OVERFALL

    E-Print Network [OSTI]

    Julien, Pierre Y.

    SEDIMENT CONCENTRATION BELOW FREE OVERFALL By O. R. Stein,~Associate Member, ASCE, and P. Y. Julien and sediment concentration, which may affect downstream morphology and water quality as well as the structure is to determine relationships between time, scour depth, scour-hole volume, and sediment concentration generated

  3. DOE High Performance Concentrator PV Project

    SciTech Connect (OSTI)

    McConnell, R.; Symko-Davies, M.

    2005-08-01

    Much in demand are next-generation photovoltaic (PV) technologies that can be used economically to make a large-scale impact on world electricity production. The U.S. Department of Energy (DOE) initiated the High-Performance Photovoltaic (HiPerf PV) Project to substantially increase the viability of PV for cost-competitive applications so that PV can contribute significantly to both our energy supply and environment. To accomplish such results, the National Center for Photovoltaics (NCPV) directs in-house and subcontracted research in high-performance polycrystalline thin-film and multijunction concentrator devices with the goal of enabling progress of high-efficiency technologies toward commercial-prototype products. We will describe the details of the subcontractor and in-house progress in exploring and accelerating pathways of III-V multijunction concentrator solar cells and systems toward their long-term goals. By 2020, we anticipate that this project will have demonstrated 33% system efficiency and a system price of $1.00/Wp for concentrator PV systems using III-V multijunction solar cells with efficiencies over 41%.

  4. Alpha Solarco`s Photovoltaic Concentrator Development program

    SciTech Connect (OSTI)

    Anderson, A.; Bailor, B.; Carroll, D.

    1995-10-01

    This report details the work done under Sandia`s Photovoltaic Concentrator Development contract, funded jointly by Alpha Solarco and the US Department of Energy. It discusses improvements made to the cell assembly and module design of Alpha Solarco`s point-focus, high-concentration photovoltaic module. The goals of this effort were to increase the module efficiency, reduce the manufacturing cost of the cell assembly, and increase product reliability. Redesign of the secondary optical element achieved a 4 percent increase in efficiency due to better cell fill factors and offtrack performance. New, lower cost materials were identified for the secondary optical element, the optical couple between the secondary optical element and the cell, and the cell assembly electrical insulator. Manufacturing process improvements and test equipment are also discussed.

  5. Light shield for solar concentrators

    DOE Patents [OSTI]

    Plesniak, Adam P.; Martins, Guy L.

    2014-08-26

    A solar receiver unit including a housing defining a recess, a cell assembly received in the recess, the cell assembly including a solar cell, and a light shield received in the recess and including a body and at least two tabs, the body defining a window therein, the tabs extending outward from the body and being engaged with the recess, wherein the window is aligned with the solar cell.

  6. Energy 101: Concentrating Solar Power

    K-12 Energy Lesson Plans and Activities Web site (EERE)

    From towers to dishes to linear mirrors to troughs, concentrating solar power (CSP) technologies reflect and collect solar heat to generate electricity.

  7. Utility-scale photovoltaic concentrators

    SciTech Connect (OSTI)

    None, None

    2009-01-18

    The photovoltaics concentrators section of the Renewable Energy Technology Characterizations describes the technical and economic status of this emerging renewable energy option for electricity supply.

  8. Matrix Factorization and Matrix Concentration

    E-Print Network [OSTI]

    Mackey, Lester

    2012-01-01

    PCA 3 Mixed Membership Matrix Factorization 3.15.2 Matrix concentration3.3 Mixed Membership Matrix Factorization . . . 3.4

  9. Continuous flow dielectrophoretic particle concentrator

    DOE Patents [OSTI]

    Cummings, Eric B. (Livermore, CA)

    2007-04-17

    A continuous-flow filter/concentrator for separating and/or concentrating particles in a fluid is disclosed. The filter is a three-port device an inlet port, an filter port and a concentrate port. The filter separates particles into two streams by the ratio of their dielectrophoretic mobility to their electrokinetic, advective, or diffusive mobility if the dominant transport mechanism is electrokinesis, advection, or diffusion, respectively.Also disclosed is a device for separating and/or concentrating particles by dielectrophoretic trapping of the particles.

  10. Energy 101: Concentrating Solar Power

    Broader source: Energy.gov [DOE]

    Concentrating solar power technologies use mirrors to reflect sunshine, turning it into an intense beam that’s collected as heat.

  11. Electrochemical cell

    DOE Patents [OSTI]

    Redey, L.I.; Vissers, D.R.; Prakash, J.

    1994-08-23

    An electrochemical cell is described having an alkali metal negative electrode such as sodium and a positive electrode including Ni or transition metals, separated by a [beta] alumina electrolyte and NaAlCl[sub 4] or other compatible material. Various concentrations of a bromine, iodine and/or sulfur containing additive and pore formers are disclosed, which enhance cell capacity and power. The pore formers may be the ammonium salts of carbonic acid or a weak organic acid or oxamide or methylcellulose. 6 figs.

  12. Declaration of Concentration in Nanotechnology

    E-Print Network [OSTI]

    Lin, Xi

    Declaration of Concentration in Nanotechnology Return completed form to ENG Undergraduate Records:____________________________ Instructions: ENG students declaring a Concentration in Nanotechnology should complete this form, obtain REQUIRED COURSES (Choose 1) 1. ENG EK 481­ Fundamentals of Nanomaterials and Nanotechnology 4.0 ELECTIVES

  13. Declaration of Concentration in Nanotechnology

    E-Print Network [OSTI]

    Goldberg, Bennett

    Declaration of Concentration in Nanotechnology Return completed form to ENG Undergraduate Records:____________________________ Instructions: ENG students declaring a Concentration in Nanotechnology should complete this form, obtain REQUIRED COURSES (Choose 1) 1. ENG EC 481­ Fundamentals of Nanomaterials and Nanotechnology 4.0 ELECTIVES

  14. Process for concentrated biomass saccharification

    DOE Patents [OSTI]

    Hennessey, Susan M. (Avondale, PA); Seapan, Mayis (Landenberg, PA); Elander, Richard T. (Evergreen, CO); Tucker, Melvin P. (Lakewood, CO)

    2010-10-05

    Processes for saccharification of pretreated biomass to obtain high concentrations of fermentable sugars are provided. Specifically, a process was developed that uses a fed batch approach with particle size reduction to provide a high dry weight of biomass content enzymatic saccharification reaction, which produces a high sugars concentration hydrolysate, using a low cost reactor system.

  15. The effect of methanol concentration on the performance of a passive DMFC

    E-Print Network [OSTI]

    Zhao, Tianshou

    The effect of methanol concentration on the performance of a passive DMFC J.G. Liu, T.S. Zhao *, R-breathing liquid feed direct methanol fuel cell (DMFC), with no external pumps or other auxiliary devices, was designed, fabricated and tested with different methanol concentrations. It was found that the cell

  16. Correlations in Characteristic Data of Concentrator Photovoltaics (Poster)

    SciTech Connect (OSTI)

    Sweet, C.; Bosco, N.; Kurtz, S.

    2011-02-01

    This study is motivated by a reported 1-2% infant mortality rate in concentrator photovoltaic cell assemblies. Approximately 650 bare III-V multi-junction PV cells were initially characterized via electroluminescence imaging and both light and dark current-voltage responses were recorded. The cells were then packaged into receivers and their IV response again evaluated both before and after an outdoor high concentration exposure of at least four hours above 750 DNI. Correlations exist between the initial dark IV characteristic and artifacts found in the EL image. Initial results also suggest that artifacts observed in the bare cell may serve as an indicator for early on-sun degradation, though may not be able to predict the infant mortality population.

  17. Planar micro-optic solar concentration

    E-Print Network [OSTI]

    Karp, Jason Harris

    2010-01-01

    silicon cells 2 . Multi-junction solar cells hope becomethe motivation for multi- junction solar cells which layerassociated with multi-junction solar cells. The superior

  18. Planar micro-optic solar concentration

    E-Print Network [OSTI]

    Karp, Jason Harris

    2010-01-01

    of performance ratio for multijunction cells," in 2009 34th292 [2] King, R.R. “Multijunction Cells: Record Breakers,”other cell technologies, multijunction cell performance has

  19. Automated micro-tracking planar solar concentrators

    E-Print Network [OSTI]

    Hallas, Justin Matthew

    2011-01-01

    from Concentrix Solar," in Concentrator Photovoltaics, A.L.Solar Concentrators: Using optics to boost photovoltaics,”Solar Concentrators: Using optics to boost photovoltaics,”

  20. Automated micro-tracking planar solar concentrators

    E-Print Network [OSTI]

    Hallas, Justin Matthew

    2011-01-01

    self-tracking solar concentration: design and materialsself- tracking solar concentration: design and materialsSolar Concentrators," in International Optical Design

  1. Fluorescence Correlation Spectroscopy at Micromolar Concentrations without Optical Nanoconfinement

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

    Laurence, Ted A.; Ly, Sonny; Bourguet, Feliza; Fischer, Nicholas O.; Coleman, Matthew A.

    2014-08-14

    Fluorescence correlation spectroscopy (FCS) is an important technique for studying biochemical interactions dynamically that may be used in vitro and in cell-based studies. It is generally claimed that FCS may only be used at nM concentrations. We show that this general consensus is incorrect and that the limitation to nM concentrations is not fundamental but due to detector limits as well as laser fluctuations. With a high count rate detector system and applying laser fluctuation corrections, we demonstrate FCS measurements up to 38 ?M with the same signal-to-noise as at lower concentrations. Optical nanoconfinement approaches previously used to increase themore »concentration range of FCS are not necessary, and further increases above 38 ?M may be expected using detectors and detector arrays with higher saturation rates and better laser fluctuation corrections. This approach greatly widens the possibilities of dynamic measurements of biochemical interactions using FCS at physiological concentrations.« less

  2. Fluorescence Correlation Spectroscopy at Micromolar Concentrations without Optical Nanoconfinement

    SciTech Connect (OSTI)

    Laurence, Ted A.; Ly, Sonny; Bourguet, Feliza; Fischer, Nicholas O.; Coleman, Matthew A.

    2014-08-14

    Fluorescence correlation spectroscopy (FCS) is an important technique for studying biochemical interactions dynamically that may be used in vitro and in cell-based studies. It is generally claimed that FCS may only be used at nM concentrations. We show that this general consensus is incorrect and that the limitation to nM concentrations is not fundamental but due to detector limits as well as laser fluctuations. With a high count rate detector system and applying laser fluctuation corrections, we demonstrate FCS measurements up to 38 ?M with the same signal-to-noise as at lower concentrations. Optical nanoconfinement approaches previously used to increase the concentration range of FCS are not necessary, and further increases above 38 ?M may be expected using detectors and detector arrays with higher saturation rates and better laser fluctuation corrections. This approach greatly widens the possibilities of dynamic measurements of biochemical interactions using FCS at physiological concentrations.

  3. Photovoltaic solar cell

    DOE Patents [OSTI]

    Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.

    2015-09-08

    A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.

  4. Physics and Astronomy Geophysics Concentration

    E-Print Network [OSTI]

    Thaxton, Christopher S.

    Physics and Astronomy Geophysics Concentration Strongly recommended courses Credits Term Dept. to Geophysics 3 PHY 3230 Thermal Physics 3 CHE 1101 Introductory Chemistry - I 3 CHE 1110 Introductory Chemistry

  5. 500-watt commercialized concentrator system

    SciTech Connect (OSTI)

    Ronney, K.; Aerni, E.

    1983-02-01

    A passively cooled, single-axis tracking, polar-axis mounted photovoltaic concentrator system has been designed, fabricated, installed, and tested. System description, design considerations, system performance and a production cost estimate are detailed.

  6. Design of inflatable solar concentrator

    E-Print Network [OSTI]

    Carrasquillo, Omar (Omar Y. Carrasquillo De Armas)

    2013-01-01

    Solar concentrators improve the performance of solar collection systems by increasing the amount of usable energy available for a given collector size. Unfortunately, they are not known for their light weight and portability, ...

  7. Reversible concentric ring microfluidic interconnects

    E-Print Network [OSTI]

    Thompson, Mary Kathryn, 1980-

    2004-01-01

    A reversible, Chip-to-Chip microfluidic interconnect was designed for use in high temperature, high pressure applications such as chemical microreactor systems. The interconnect uses two sets of concentric, interlocking ...

  8. Concentrating Solar Power (Fact Sheet)

    SciTech Connect (OSTI)

    DOE Solar Energy Technologies Program

    2011-10-13

    Concentrating Solar Power (CSP) offers a utility-scale, firm, dispatchable renewable energy option that can help meet the nation's goal of making solar energy cost competitive with other energy sources by the end of the decade.

  9. Concentrating Solar Power Competitive Awards

    Broader source: Energy.gov [DOE]

    DOE funds concentrating solar power (CSP) research and development (R&D) projects through competitive solicitations, which are released for public response as financial opportunity announcements. The following projects represent recent and ongoing research efforts.

  10. Energy 101: Concentrating Solar Power

    Broader source: Energy.gov [DOE]

    From towers to dishes to linear mirrors to troughs, concentrating solar power (CSP) technologies reflect and collect solar heat to generate electricity. A single CSP plant can generate enough power...

  11. Concentrated solar power on demand

    E-Print Network [OSTI]

    Codd, Daniel Shawn

    2011-01-01

    This thesis describes a new concentrating solar power central receiver system with integral thermal storage. Hillside mounted heliostats direct sunlight into a volumetric absorption molten salt pool, which also functions ...

  12. MATHEMATICS MAJOR CONCENTRATION/SPECIALIZATION APPLICATION FORM

    E-Print Network [OSTI]

    Loudon, Catherine

    MATHEMATICS MAJOR CONCENTRATION/SPECIALIZATION APPLICATION FORM Date _______________ Last Name/Year) __________ Check One Concentration/Specialization: Concentration in Mathematical Finance. Advisor: Professor Matthew Foreman (RH 440A, mforeman@math.uci.edu) Concentration in Mathematics for Education

  13. Concentrating Solar Power Commercial Application Study

    E-Print Network [OSTI]

    Laughlin, Robert B.

    Concentrating Solar Power Commercial Application Study: Reducing Water Consumption of Concentrating Concentrating Solar Power Technologies............................................... 7 Parabolic Troughs of water consumed by concentrating solar power systems." Because of the huge solar resource available

  14. Concentrating Solar Power: Efficiently Leveraging Equilibrium...

    Energy Savers [EERE]

    Concentrating Solar Power: Efficiently Leveraging Equilibrium Mechanisms for Engineering New Thermochemical Storage Concentrating Solar Power: Efficiently Leveraging Equilibrium...

  15. Planar micro-optic solar concentration

    E-Print Network [OSTI]

    Karp, Jason Harris

    2010-01-01

    for multijunction cells," in 2009 34th IEEE Photovoltaicmultijunction solar cell (Cyrium Technologies). The photovoltaic

  16. Optofluidic solar concentrators using electrowetting tracking: Concept, design, and characterization

    SciTech Connect (OSTI)

    Cheng, JT; Park, S; Chen, CL

    2013-03-01

    We introduce a novel optofluidic solar concentration system based on electrowetting tracking. With two immiscible fluids in a transparent cell, we can actively control the orientation of fluid fluid interface via electrowetting. The naturally-formed meniscus between the two liquids can function as a dynamic optical prism for solar tracking and sunlight steering. An integrated optofluidic solar concentrator can be constructed from the liquid prism tracker in combination with a fixed and static optical condenser (Fresnel lens). Therefore, the liquid prisms can adaptively focus sunlight on a concentrating photovoltaic (CPV) cell sitting on the focus of the Fresnel lens as the sun moves. Because of the unique design, electrowetting tracking allows the concentrator to adaptively track both the daily and seasonal changes of the sun's orbit (dual-axis tracking) without bulky, expensive and inefficient mechanical moving parts. This approach can potentially reduce capital costs for CPV and increases operational efficiency by eliminating the power consumption of mechanical tracking. Importantly, the elimination of bulky tracking hardware and quiet operation will allow extensive residential deployment of concentrated solar power. In comparison with traditional silicon-based photovoltaic (PV) solar cells, the electrowetting-based self-tracking technology will generate,similar to 70% more green energy with a 50% cost reduction. (C) 2013 Elsevier Ltd. All rights reserved.

  17. Effect of Transient Ammonia Concentrations on PEMFC Performance

    E-Print Network [OSTI]

    Van Zee, John W.

    Effect of Transient Ammonia Concentrations on PEMFC Performance Herie J. Soto,a, * Woo-kum Lee electrode assembly MEA performance in proton exchange membrane fuel cells PEMFCs . Steady-state tests were that maintain PEMFC performance should the anode stream be exposed to high transient levels of NH3

  18. Daily Fill Factor Variation as a Diagnostic Probe of Multijunction Concentrator Systems During Outdoor Operation

    SciTech Connect (OSTI)

    McMahon, W. E.; Emery, K. E.; Friedman, D. J.; Ottoson, L.; Young, M. S.; Ward, J. S.; Kramer, C. M.; Duda, A.; Kurtz, S.

    2007-01-01

    The work presented here is for GaInP2/GaAs tandem cells, but the conclusions are equally valid for GaInP2/GaAs/Ge triple-junction cells. Optimizing a concentrator system which uses multijunction solar cells is challenging because: (a) the conditions are variable, so the solar cells rarely operate under optimal conditions and (b) the conditions are not controlled, so any design problems are difficult to characterize. Any change in the spectral content of direct-beam sunlight as it passes through the concentrator optics is of particular interest, as it can reduce the performance of multijunction cells and is difficult to characterize.

  19. Cost effective manufacturing of the SEA 10X concentrator array

    SciTech Connect (OSTI)

    Kaminar, N.; McEntee, J.; Curchod, D. (Solar Engineering Applications Corp., San Jose, CA (United States))

    1991-11-01

    This report describes a low-cost, mass-producible 10X concentrator system that has been claimed to produce electricity at $0.04/kWh. It details changes in manufacturing techniques that could produce a concentrator system at a selling price of $0.71/W. (A simple design and a minimum number of parts and manufacturing steps reduced production costs.) Present production techniques, changes to improve these techniques, impediments to changes, and solutions to the impediments are described. This 10X concentrator system uses available components and manufacturing processes and one-sun solar cells in conjunction with inexpensive plastic lenses to generate about eight times the amount of electricity normally produced by these cells.

  20. Energy 101: Concentrating Solar Power

    ScienceCinema (OSTI)

    None

    2013-05-29

    From towers to dishes to linear mirrors to troughs, concentrating solar power (CSP) technologies reflect and collect solar heat to generate electricity. A single CSP plant can generate enough power for about 90,000 homes. This video explains what CSP is, how it works, and how systems like parabolic troughs produce renewable power. For more information on the Office of Energy Efficiency and Renewable Energy's CSP research, see the Solar Energy Technology Program's Concentrating Solar Power Web page at http://www1.eere.energy.gov/solar/csp_program.html.

  1. Energy 101: Concentrating Solar Power

    SciTech Connect (OSTI)

    None

    2010-01-01

    From towers to dishes to linear mirrors to troughs, concentrating solar power (CSP) technologies reflect and collect solar heat to generate electricity. A single CSP plant can generate enough power for about 90,000 homes. This video explains what CSP is, how it works, and how systems like parabolic troughs produce renewable power. For more information on the Office of Energy Efficiency and Renewable Energy's CSP research, see the Solar Energy Technology Program's Concentrating Solar Power Web page at http://www1.eere.energy.gov/solar/csp_program.html.

  2. Concentration Averaging | Department of Energy

    Office of Environmental Management (EM)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (BillionProvedTravel TravelChallenges |1-01Concentrating Solar Power Concentrating Solar

  3. High concentration low wattage solar arrays and their applications

    SciTech Connect (OSTI)

    Hoffmann, R.; OGallagher, J.; Winston, R.

    1997-02-01

    Midway Labs currently produces a 335x concentrator module that has reached as high as 19{percent} active area efficiency in production. The current production module uses the single crystal silicon back contact SunPower cell. The National Renewable Energy Lab has developed a multi junction cell using GalnP/GaAs technologies. The high efficiency ({gt}30{percent}) and high cell voltage offer an opportunity for Midway Labs to develop a tracking concentrator module that will provide 24 volts in the 140 to 160 watt range. This voltage and wattage range is applicable to a range of small scale water pumping applications that make up the bulk of water pumping solar panel sales. {copyright} {ital 1997 American Institute of Physics.}

  4. Modular off-axis solar concentrator

    DOE Patents [OSTI]

    Plesniak, Adam P; Hall, John C

    2015-01-27

    A solar concentrator including a housing defining a vertical axis and including a receiving wall connected to a reflecting wall to define an internal volume and an opening into the internal volume, wherein the reflecting wall defines at least one primary optical element, and wherein at least a portion of the reflecting wall includes a layer of reflective material, the housing further including a cover connected to the receiving wall and the reflecting wall to seal the opening, and at least one receiver mounted on the receiving wall such that a vertical axis of the receiver is disposed at a non-zero angle relative to the vertical axis of the housing, the receiver including at least one photovoltaic cell.

  5. Enclosed, off-axis solar concentrator

    DOE Patents [OSTI]

    Benitez, Pablo; Grip, Robert E; Minano, Juan C; Narayanan, Authi A; Plesniak, Adam; Schwartz, Joel A

    2013-11-26

    A solar concentrator including a housing having receiving wall, a reflecting wall and at least two end walls, the receiving, reflecting and end walls defining a three-dimensional volume having an inlet, wherein a vertical axis of the housing is generally perpendicular to the inlet, a receiver mounted on the receiving wall of the housing, the receiver including at least one photovoltaic cell, wherein a vertical axis of the receiver is disposed at a non-zero angle relative to the vertical axis of the housing, at least one clip disposed on the reflecting wall an optical element received within the three-dimensional volume, the optical element including at least one tab, the tab being engaged by the clip to align the optical element with the receiver, and a window received over the inlet to enclose the housing.

  6. TOPCAT Solar Cell Alignment & Energy Concentration Technology - Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With LivermoreSustainableDEPARTMENT OF ENERGYFAQS08RV14800Innovation

  7. Planar micro-optic solar concentration

    E-Print Network [OSTI]

    Karp, Jason Harris

    2010-01-01

    connects to a single photovoltaic cell. We refer to thisplane. Optimized photovoltaic cells can be interleaved on aand expenses. Photovoltaic cells are commonly connected into

  8. Automated micro-tracking planar solar concentrators

    E-Print Network [OSTI]

    Hallas, Justin Matthew

    2011-01-01

    c) Cyrium multi-junction solar cell. (d) Faulhaber miniaturecan leverage expensive multi-junction solar cells to achievec) Cyrium multi-junction solar cell. ( d) Faulhaber

  9. Electrokinetic concentration of charged molecules

    DOE Patents [OSTI]

    Singh, Anup K. (Berkeley, CA); Neyer, David W. (Castro Valley, CA); Schoeniger, Joseph S. (Oakland, CA); Garguilo, Michael G. (Livermore, CA)

    2002-01-01

    A method for separating and concentrating charged species from uncharged or neutral species regardless of size differential. The method uses reversible electric field induced retention of charged species, that can include molecules and molecular aggregates such as dimers, polymers, multimers, colloids, micelles, and liposomes, in volumes and on surfaces of porous materials. The retained charged species are subsequently quantitatively removed from the porous material by a pressure driven flow that passes through the retention volume and is independent of direction thus, a multi-directional flow field is not required. Uncharged species pass through the system unimpeded thus effecting a complete separation of charged and uncharged species and making possible concentration factors greater than 1000-fold.

  10. Cylindrical acoustic levitator/concentrator

    DOE Patents [OSTI]

    Kaduchak, Gregory (Los Alamos, NM); Sinha, Dipen N. (Los Alamos, NM)

    2002-01-01

    A low-power, inexpensive acoustic apparatus for levitation and/or concentration of aerosols and small liquid/solid samples having particulates up to several millimeters in diameter in air or other fluids is described. It is constructed from a commercially available, hollow cylindrical piezoelectric crystal which has been modified to tune the resonance frequency of the breathing mode resonance of the crystal to that of the interior cavity of the cylinder. When the resonance frequency of the interior cylindrical cavity is matched to the breathing mode resonance of the cylindrical piezoelectric transducer, the acoustic efficiency for establishing a standing wave pattern in the cavity is high. The cylinder does not require accurate alignment of a resonant cavity. Water droplets having diameters greater than 1 mm have been levitated against the force of gravity using; less than 1 W of input electrical power. Concentration of aerosol particles in air is also demonstrated.

  11. MATHEMATICS MAJOR CONCENTRATION/SPECIALIZATION APPLICATION FORM

    E-Print Network [OSTI]

    Loudon, Catherine

    MATHEMATICS MAJOR CONCENTRATION/SPECIALIZATION APPLICATION FORM Date _______________ Last Name/Year) __________ Check One Concentration/Specialization: Concentration in Mathematics for Education/Secondary Teaching, apantano@uci.edu) Specialization in Applied Computational Mathematics. Advisor: Professor Hongkai Zhao (RH

  12. Experiential Component Approval Form Concentration in Nanotechnology

    E-Print Network [OSTI]

    Experiential Component Approval Form Concentration in Nanotechnology Return completed form to ENG Plan to complete the experiential component as a requirement for the concentration in Nanotechnology to complete the experiential component for the Nanotechnology Concentration by: Research Experience in Lab

  13. Funding Opportunity Announcement: CSP: Concentrating Optics for...

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

    CSP: Concentrating Optics for Lower Levelized Energy Costs (COLLECTS) Funding Opportunity Announcement: CSP: Concentrating Optics for Lower Levelized Energy Costs (COLLECTS)...

  14. Sandia Energy - Concentrating Solar Power Technical Management...

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

    Concentrating Solar Power Technical Management Position Home Renewable Energy Energy Facilities News Concentrating Solar Power Solar Job Listing National Solar Thermal Test...

  15. Automated micro-tracking planar solar concentrators

    E-Print Network [OSTI]

    Hallas, Justin Matthew

    2011-01-01

    I : Introduction I.A Concentrated Photovoltaic Systemsconcentrated photovoltaic (CPV) systems and their trackingConcentrated photovoltaic (CPV) systems use optical

  16. Energy Secretary Moniz Dedicates World's Largest Concentrating...

    Energy Savers [EERE]

    Dedicates World's Largest Concentrating Solar Power Project Energy Secretary Moniz Dedicates World's Largest Concentrating Solar Power Project February 13, 2014 - 5:00am Addthis...

  17. The role of Förster Resonance Energy Transfer in luminescent solar concentrator efficiency and color tunability

    E-Print Network [OSTI]

    Balaban, Benjamin

    2013-01-01

    design," Solar Energy Materials and Solar Cells Vol. 111,Solar Energy for the Built Environment," Advanced Energy Materials,energy transfer (FRET) is demonstrated in a luminescent solar concentrator (LSC) material

  18. A NEW ANALYTICAL MODEL FOR STRESS CONCENTRATION AROUND HARD SPHERICAL PARTICLES IN METAL MATRIX COMPOSITES 

    E-Print Network [OSTI]

    Harris, Matthew Wade

    2007-09-17

    This analytical model predicts the stress concentration around an elastic, spherical particle in an elastic-plastic metal matrix using strain gradient plasticity theory and a finite unit cell. The model reduces to the special case with a spherical...

  19. ARM - Measurement - Particle number concentration

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska Outreach Home Roomparticlecontentnumber concentration ARM Data

  20. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Poster)

    SciTech Connect (OSTI)

    Miller, D. C.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2011-02-01

    Polymeric encapsulation materials are typically used in concentrating photovoltaic (CPV) modules to protect the cell from the field environment. Because it is physically located adjacent to the cell, the encapsulation is exposed to a high optical flux, often including light in the ultraviolet (UV) and infrared (IR) wavelengths. The durability of encapsulants used in CPV modules is critical to the technology, but is presently not well understood. This work seeks to identify the appropriate material types, field-induced failure mechanisms, and factors of influence (if possible) of polymeric encapsulation. These results will ultimately be weighed against those of future qualification and accelerated life test procedures.

  1. Concentration-Dependent Diffusion Instability in Reactive Miscible Fluids

    E-Print Network [OSTI]

    Bratsun, Dmitry; Mizev, Alexey; Mosheva, Elena

    2015-01-01

    We report new chemoconvective pattern formation phenomena observed in a two-layer system of miscible fluids filling a vertical Hele-Shaw cell. We show both experimentally and theoretically that the concentration-dependent diffusion coupled with the frontal acid-base neutralization can give rise to formation of the local unstable zone low in density resulting in a perfectly regular cell-type convective pattern. The described effect gives an example of yet another powerful mechanism which allows the reaction-diffusion processes to govern the flow of reacting fluids under gravity condition.

  2. Nonimaging Optical Gain in Luminescent Concentration through Photonic Control of Emission Etendue

    E-Print Network [OSTI]

    Rogers, John A.

    and show that it delivers three times more luminescent power to an opposing GaAs photovoltaic cell when their concentration ratio because their emission is angularly isotropic. Here, we use a luminescent thin film bilayer: luminescence, solar concentration, nonimaging optics, microcavity, spontaneous emission, photovoltaics

  3. Biosensor Arrays for Estimating Molecular Concentration in Fluid Flows

    E-Print Network [OSTI]

    Abolfath-Beygi, Maryam

    2011-01-01

    This paper constructs dynamical models and estimation algorithms for the concentration of target molecules in a fluid flow using an array of novel biosensors. Each biosensor is constructed out of protein molecules embedded in a synthetic cell membrane. The concentration evolves according to an advection-diffusion partial differential equation which is coupled with chemical reaction equations on the biosensor surface. By using averaging theory methods and the divergence theorem, an approximate model is constructed that describes the asymptotic behaviour of the concentration as a system of ordinary differential equations. The estimate of target molecules is then obtained by solving a nonlinear least squares problem. It is shown that the estimator is strongly consistent and asymptotically normal. An explicit expression is obtained for the asymptotic variance of the estimation error. As an example, the results are illustrated for a novel biosensor built out of protein molecules.

  4. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Presentation)

    SciTech Connect (OSTI)

    Miller, D. C.; Muller, M.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2012-03-01

    Many concentrating photovoltaic (CPV) systems use a polymeric encapsulant to couple and optical component and/or coverglass to the cell. In that location, the encapsulation improves the transmission of concentrated optical flux through interface(s), while protecting the cell from the environment. The durability of encapsulation materials, however, is not well established relative to the desired service life of 30 years. Therefore, we have initiated a screen test to identify the field-induced failure modes for a variety of popular PV encapsulation materials. An existing CPV module (with no PV cells present) was modified to accommodate encapsulation specimens. The module (where nominal concentration of solar flux is 500x for the domed-Fresnel design) has been mounted on a tracker in Golden, CO (elevation 1.79 km). Initial results are reported here for 18 months cumulative exposure, including the hottest and coldest months of the past year. Characteristics observed at intervals during that time include: visual appearance, direct and hemispherical transmittance, and mass. Degradation may be assessed from subsequent analysis (including yellowness index and cut-on frequency) relative to the ambient conditions present during field exposure. The fluorescence signature observed of all the silicone specimens is examined here, including possible factors of causation -- the platinum catalyst used in the addition cured materials as well as the primer used to promote adhesion to the quartz substrate and superstrate.

  5. The Rheology of Concentrated Suspensions

    SciTech Connect (OSTI)

    Andreas Acrivos

    2004-09-07

    Research program on the rheological properties of flowing suspensions. The primary purpose of the research supported by this grant was to study the flow characteristics of concentrated suspensions of non-colloidal solid particles and thereby construct a comprehensive and robust theoretical framework for modeling such systems quantitatively. At first glance, this seemed like a modest goal, not difficult to achieve, given that such suspensions were viewed simply as Newtonian fluids with an effective viscosity equal to the product of the viscosity of the suspending fluid times a function of the particle volume fraction. But thanks to the research findings of the Principal Investigator and of his Associates, made possible by the steady and continuous support which the PI received from the DOE Office of Basic Energy Sciences, the subject is now seen to be more complicated and therefore much more interesting in that concentrated suspensions have been shown to exhibit fascinating and unique rheological properties of their own that have no counterpart in flowing Newtonian or even non-Newtonian (polymeric) fluids. In fact, it is generally acknowledged that, as the result of these investigations for which the PI received the 2001 National Medal of Science, our understanding of how suspensions behave under flow is far more detailed and comprehensive than was the case even as recently as a decade ago. Thus, given that the flow of suspensions plays a crucial role in many diverse physical processes, our work has had a major and lasting impact in a subject having both fundamental as well as practical importance.

  6. Ultra-High-Efficiency Multijunction Cell and Receiver Module, Phase 1B: High Performance PV Exploring and Accelerating Ultimate Pathways; Final Subcontract Report, 13 May 2005 - 10 December 2008

    SciTech Connect (OSTI)

    King, R. R.

    2010-03-01

    Spectrolab's two High Performance Photovoltaics primary objectives: (1) develop ultra-high-efficiency concentrator multijunction cells and (2) develop a robust concentrator cell receiver package.

  7. Planar micro-optic solar concentration

    E-Print Network [OSTI]

    Karp, Jason Harris

    2010-01-01

    and W. Warta, "Solar cell efficiency tables (version 35), "1.1 Multijunction solar cell efficiency (purple) has rapidly1.1 Multijunction solar cell efficiency (purple) has rapidly

  8. Production of fullerenes using concentrated solar flux

    DOE Patents [OSTI]

    Fields, Clark L. (Greeley, CO); Pitts, John Roland (Lakewood, CO); King, David E. (Lakewood, CO); Hale, Mary Jane (Golden, CO); Bingham, Carl E. (Denver, CO); Lewandowski, Allan A. (Evergreen, CO)

    2000-01-01

    A method of producing soot containing high amounts of fullerenes comprising: providing a primary concentrator capable of impingement of a concentrated beam of sunlight onto a carbon source to cause vaporization of carbon and subsequent formation of fullerenes, or providing a solar furnace having a primary concentrator with a focal point that concentrates a solar beam of sunlight; providing a reflective secondary concentrator having an entrance aperture and an exit aperture at the focal point of the solar furnace; providing a carbon source at the exit aperture of the secondary concentrator; supplying an inert gas over the carbon source to keep the secondary concentrator free from vaporized carbon; and impinging a concentrated beam of sunlight from the secondary concentrator on the carbon source to vaporize the carbon source into a soot containing high amounts of fullerenes.

  9. A 40KW ROOF MOUNTED PV THERMAL CONCENTRATOR SYSTEM J.F.H. Smeltink1

    E-Print Network [OSTI]

    thermal (PV-T) concentrator system. This system is based on its Combined Heat and Power Solar (CHAPS called Combined Heat and Power Solar (CHAPS) Systems. During 2002 the Australian Greenhouse Office made of 37x. Heat is removed from the solar cells using a fluid, which flows through a passage in the cell

  10. Pattern recognition monitoring of PEM fuel cell

    DOE Patents [OSTI]

    Meltser, Mark Alexander (Pittsford, NY)

    1999-01-01

    The CO-concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and voltage behavior patterns from an auxiliary cell attached to the end of the stack. The auxiliary cell is connected to the same oxygen and hydrogen feed manifolds that supply the stack, and discharges through a constant load. Pattern recognition software compares the current and voltage patterns from the auxiliary cell to current and voltage signature determined from a reference cell similar to the auxiliary cell and operated under controlled conditions over a wide range of CO-concentrations in the H.sub.2 fuel stream.

  11. Pattern recognition monitoring of PEM fuel cell

    DOE Patents [OSTI]

    Meltser, M.A.

    1999-08-31

    The CO-concentration in the H{sub 2} feed stream to a PEM fuel cell stack is monitored by measuring current and voltage behavior patterns from an auxiliary cell attached to the end of the stack. The auxiliary cell is connected to the same oxygen and hydrogen feed manifolds that supply the stack, and discharges through a constant load. Pattern recognition software compares the current and voltage patterns from the auxiliary cell to current and voltage signature determined from a reference cell similar to the auxiliary cell and operated under controlled conditions over a wide range of CO-concentrations in the H{sub 2} fuel stream. 4 figs.

  12. Series cell light extinction monitor

    DOE Patents [OSTI]

    Novick, Vincent J. (Downers Grove, IL)

    1990-01-01

    A method and apparatus for using the light extinction measurements from two or more light cells positioned along a gasflow chamber in which the gas volumetric rate is known to determine particle number concentration and mass concentration of an aerosol independent of extinction coefficient and to determine estimates for particle size and mass concentrations. The invention is independent of particle size. This invention has application to measurements made during a severe nuclear reactor fuel damage test.

  13. Ultrahigh Efficiency Multiband Solar Cells Final Report for Director's Innovation Initiative Project DII-2005-1221

    E-Print Network [OSTI]

    Ager III, Joel W.; Walukiewicz, W.; Yu, Kin Man

    2006-01-01

    triple junction (3J) cells under maximum concentration [2,3] and cells of this design are used in high-efficiency solar

  14. ORIGINAL PAPER Controls of Suspended Sediment Concentration,

    E-Print Network [OSTI]

    ORIGINAL PAPER Controls of Suspended Sediment Concentration, Nutrient Content, and Transport 2009 Abstract Redistribution of largely organic sediment from low elevation sloughs to higher elevation by measuring the concentration and character- istics of suspended sediment and its associated nutrients

  15. Modeling of concentrating solar thermoelectric generators

    E-Print Network [OSTI]

    Ren, Zhifeng

    The conversion of solar power into electricity is dominated by non-concentrating photovoltaics and concentrating solar thermal systems. Recently, it has been shown that solar thermoelectric generators (STEGs) are a viable ...

  16. Planar micro-optic solar concentration

    E-Print Network [OSTI]

    Karp, Jason Harris

    2010-01-01

    version 35), "Progress in Photovoltaics: Research andsolar cell modules," Progress in Photovoltaics: Research and

  17. Concentration in Mathematics (2015-2016)

    E-Print Network [OSTI]

    Concentration in Mathematics (2015-2016) What Can You Do With Math? Concentration in mathematics is an excellent preparation for a career in either pure or applied mathematics, in academia or in industry on mathematical methods, a math concentration can provide an invaluable background for many different careers

  18. Fuel cell CO sensor

    DOE Patents [OSTI]

    Grot, Stephen Andreas (Rochester, NY); Meltser, Mark Alexander (Pittsford, NY); Gutowski, Stanley (Pittsford, NY); Neutzler, Jay Kevin (Rochester, NY); Borup, Rodney Lynn (East Rochester, NY); Weisbrod, Kirk (Los Alamos, NM)

    1999-12-14

    The CO concentration in the H.sub.2 feed stream to a PEM fuel cell stack is monitored by measuring current and/or voltage behavior patterns from a PEM-probe communicating with the reformate feed stream. Pattern recognition software may be used to compare the current and voltage patterns from the PEM-probe to current and voltage telltale outputs determined from a reference cell similar to the PEM-probe and operated under controlled conditions over a wide range of CO concentrations in the H.sub.2 fuel stream. A CO sensor includes the PEM-probe, an electrical discharge circuit for discharging the PEM-probe to monitor the CO concentration, and an electrical purging circuit to intermittently raise the anode potential of the PEM-probe's anode to at least about 0.8 V (RHE) to electrochemically oxidize any CO adsorbed on the probe's anode catalyst.

  19. Optical loss due to diffraction by concentrator Fresnel lenses

    SciTech Connect (OSTI)

    Hornung, Thorsten Nitz, Peter

    2014-09-26

    Fresnel lenses are widely used in concentrating photovoltaic (CPV) systems as a primary optical element. They focus sunlight on small solar cells or on the entrance apertures of secondary optical elements. A Fresnel lens consists of several prism rings and diffraction by these prism rings is unavoidable. Some of the light that would reach a designated target area according to geometric optics will miss it due to diffraction. This diffraction loss may be of relevant magnitude for CPV applications. The results of published analytical calculations are evaluated, discussed, and compared to computer simulations and measurements.

  20. Alignment method for parabolic trough solar concentrators

    DOE Patents [OSTI]

    Diver, Richard B. (Albuquerque, NM)

    2010-02-23

    A Theoretical Overlay Photographic (TOP) alignment method uses the overlay of a theoretical projected image of a perfectly aligned concentrator on a photographic image of the concentrator to align the mirror facets of a parabolic trough solar concentrator. The alignment method is practical and straightforward, and inherently aligns the mirror facets to the receiver. When integrated with clinometer measurements for which gravity and mechanical drag effects have been accounted for and which are made in a manner and location consistent with the alignment method, all of the mirrors on a common drive can be aligned and optimized for any concentrator orientation.

  1. Cyclic Concentration Measurements for Characterizing Pulsating Flow

    SciTech Connect (OSTI)

    Bamberger, Judith A.

    2013-07-07

    Slurry mixed in vessels via pulse jet mixers has a periodic, rather than steady, concentration profile. Measurements of local concentration taken at the center of the tank at a range of elevations within the mixed region were analyzed to obtain a greater understanding of how the periodic pulse jet mixing cycle affects the local concentration. Data were obtained at the critical suspension velocity, when all solids are suspended at the end of the pulse. The data at a range of solids loadings are analyzed to observe the effect of solids concentration during the suspension and settling portions of the mixing cycle.

  2. Concentrating Solar Power (Revised) (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2010-11-01

    The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts within its concentrating solar power subprogram.

  3. Solar Energy Technologies Program: Concentrating Solar Power

    SciTech Connect (OSTI)

    2009-10-26

    Fact sheet summarizing the goals and activities of the DOE Solar Energy Technologies Program efforts within its concentrating solar power subprogram.

  4. Planar micro-optic solar concentration

    E-Print Network [OSTI]

    Karp, Jason Harris

    2010-01-01

    Analysis and design of holographic solar concentrators,”reflection design may enable multiband solar power usingoptical geometry and design of a two band, solar splitting

  5. Funding Opportunity Announcement: Concentrating Solar Power:...

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

    transformative projects targeting all components of a concentrating solar power (CSP) plant. Projects should seek to meet the targets set out in the SunShot Vision Study,...

  6. Planar micro-optic solar concentration

    E-Print Network [OSTI]

    Karp, Jason Harris

    2010-01-01

    mechanical tracking to maintain alignment to the sun.understand tracking needs, we first investigated the sun?stracking because it enables the concentrator to follow the sun?

  7. Microtracking and Self-Adaptive Solar Concentration

    Broader source: Energy.gov [DOE]

    This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23–25, 2013 near Phoenix, Arizona.

  8. Electrochemical separation and concentration of hydrogen sulfide from gas mixtures

    DOE Patents [OSTI]

    Winnick, Jack (Atlanta, GA); Sather, Norman F. (Naperville, IL); Huang, Hann S. (Darian, IL)

    1984-10-30

    A method of removing sulfur oxides of H.sub.2 S from high temperature gas mixtures (150.degree.-1000.degree. C.) is the subject of the present invention. An electrochemical cell is employed. The cell is provided with inert electrodes and an electrolyte which will provide anions compatible with the sulfur containing anions formed at the anode. The electrolyte is also selected to provide inert stable cations at the temperatures encountered. The gas mixture is passed by the cathode where the sulfur gases are converted to SO.sub.4 -- or, in the case of H.sub.2 S, to S--. The anions migrate to the anode where they are converted to a stable gaseous form at much greater concentration levels (>10X). Current flow may be effected by utilizing an external source of electrical energy or by passing a reducing gas such as hydrogen past the anode.

  9. MEASURE CONCENTRATION FOR COMPOUND POISSON DISTRIBUTIONS

    E-Print Network [OSTI]

    Kontoyiannis, Ioannis

    Mathematics, Brown University, 182 George Street, Providence, RI 02912, USA Email: yiannis@dam.brown.edu M. Email: mokshay@dam.brown.edu Abstract: We give a simple development of the concentration properties Poisson measure, measure concentration, entropy method, logarithmic­ Sobolev inequality, polynomial tails

  10. MEASURE CONCENTRATION FOR COMPOUND POISSON DISTRIBUTIONS

    E-Print Network [OSTI]

    Kontoyiannis, Ioannis

    Mathematics, Brown University, 182 George Street, Providence, RI 02912, USA Email: yiannis@dam.brown.edu M. Email: mokshay@dam.brown.edu Abstract: We give a simple development of the concentration properties Poisson measure, measure concentration, entropy method, logarithmic- Sobolev inequality, polynomial tails

  11. High Concentrated Photovoltaic (CPV) Masafumi Yamaguchi

    E-Print Network [OSTI]

    Canet, Léonie

    High Concentrated Photovoltaic (CPV) Masafumi Yamaguchi Toyota Technological Institute, Nagoya, 468,, other partners #12;Outline 1. Importance of High Performance, Low Cost and Highly Reliable Photovoltaics on Concentrator Photovoltaics (CPV) ; NG-CPV 4. Future Prospects of PV and Summary #12;1. Importance of High

  12. Requirements for a Concentration in Energy Technologies

    E-Print Network [OSTI]

    Technologies ­ 4 cr ENG EC 417 ­ Electric Energy Systems: Adapting to Renewable Resources ­ 4 cr Additional* - Methods of Environmental Policy ­ 4 cr ENG ME 533 ­ Energy Conversion ­ 4 cr ENG EC/ME/SE 543Requirements for a Concentration in Energy Technologies The concentration in Energy Technologies

  13. Declaration of Concentration in Manufacturing Engineering

    E-Print Network [OSTI]

    Lin, Xi

    .0 * In addition to the courses listed above, the Manufacturing Engineering Concentration requires a ManufacturingDeclaration of Concentration in Manufacturing Engineering Return completed form to ENG in Manufacturing Engineering should complete this form, obtain the signature of their Faculty Advisor below

  14. Measuring surfactant concentration in plating solutions

    DOE Patents [OSTI]

    Bonivert, William D. (Livermore, CA); Farmer, Joseph C. (Livermore, CA); Hachman, John T. (Stockton, CA)

    1989-01-01

    An arrangement for measuring the concentration of surfactants in a electrolyte containing metal ions includes applying a DC bias voltage and a modulated voltage to a counter electrode. The phase angle between the modulated voltage and the current response to the modulated voltage at a working electrode is correlated to the surfactant concentration.

  15. Spatial Inference of Nitrate Concentrations in Groundwater

    E-Print Network [OSTI]

    Woodard, Dawn B.

    Spatial Inference of Nitrate Concentrations in Groundwater DAWN B. WOODARD, ROBERT L. WOLPERT in groundwater over the mid-Atlantic states, using measurements gathered during a pe- riod of ten years. A map- trations in air, pesticide concentrations in groundwater, or any other quantity that varies over

  16. Highly concentrated foam formulation for blast mitigation

    DOE Patents [OSTI]

    Tucker, Mark D. (Albuquerque, NM); Gao, Huizhen (Albuquerque, NM)

    2010-12-14

    A highly concentrated foam formulation for blast suppression and dispersion mitigation for use in responding to a terrorism incident involving a radiological dispersion device. The foam formulation is more concentrated and more stable than the current blast suppression foam (AFC-380), which reduces the logistics burden on the user.

  17. High-Intensity Silicon Vertical Multi-Junction Solar Cells |...

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

    operation for optimum compatibility with most power processing loads. An active cooling system in the StarGen solar concentrator removes heat from the PhotoVolt cells,...

  18. CRADA Final Report: Process development for hybrid solar cells

    E-Print Network [OSTI]

    Ager, Joel W

    2011-01-01

    solar cells have the potential to reduce the cost of concentrator photovoltaic power generation (CPV) by 10-15%--an improvement

  19. Boosting Accuracy of Testing Multijunction Solar Cells (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2015-01-01

    This NREL Highlight describes research into a more precise technology for measuring efficiency of concentrating solar cells, which will enable the industry to advance.

  20. New World Record Achieved in Solar Cell Technology | Department...

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

    a concentrator solar cell produced by Boeing-Spectrolab has recently achieved a world-record conversion efficiency of 40.7 percent, establishing a new milestone in...

  1. Performance and Reliability of Multijunction III-V Modules for Concentrator Dish and Central Receiver Applications

    SciTech Connect (OSTI)

    Verlinden, P. J.; Lewandowski, A.; Bingham, C.; Kinsey, G. S.; Sherif, R. A.; Laisch, J. B.

    2006-01-01

    Over the last 15 years, Solar Systems have developed a dense array receiver PV technology for 500X concentrator reflective dish applications. This concentrator PV technology has been successfully deployed at six different locations in Australia, counting for more than 1 MWp of installed peak power. A new Multijunction III-V receiver to replace the current silicon Point-Contact solar cells has recently been developed. The new receiver technology is based on high-efficiency (>32%) Concentrator Ultra Triple Junction (CUTJ) solar cells from Spectrolab, resulting in system power and energy performance improvement of more than 50% compared to the silicon cells. The 0.235 m{sup 2} concentrator PV receiver, designed for continuous 500X operation, is composed of 64 dense array modules, and made of series and parallel-connected solar cells, totaling approximately 1,500 cells. The individual dense array modules have been tested under high intensity pulsed light, as well as with concentrated sunlight at the Solar Systems research facility and at the National Renewable Energy Laboratory's High Flux Solar Furnace. The efficiency of the dense array modules ranges from 30% to 36% at 500X (50 W/cm{sup 2}, AM1.5D low AOD, 21C). The temperature coefficients for power, voltage and current, as well as the influence of Air Mass on the cell responsivity, were measured. The reliability of the dense array multijunction III-V modules has been studied with accelerated aging tests, such as thermal cycling, damp heat and high-temperature soak, and with real-life high-intensity exposure. The first 33 kWp multijunction III-V receiver was recently installed in a Solar Systems dish and tested in real-life 500X concentrated sunlight conditions. Receiver efficiencies of 30.3% and 29.0% were measured at Standard Operating Conditions and Normal Operating Conditions respectively.

  2. GaInNAs Junctions for Next-Generation Concentrators: Progress and Prospects

    SciTech Connect (OSTI)

    Friedman, D. J.; Ptak, A. J.; Kurtz, S. R.; Geisz, J. F.; Kiehl, J.

    2005-08-01

    We discuss progress in the development of GaInNAs junctions for application in next-generation multijunction concentrator cells. A significant development is the demonstration of near-100% internal quantum efficiencies in junctions grown by molecular-beam epitaxy. Testing at high currents validates the compatibility of these devices with concentrator operation. The efficiencies of several next-generation multijunction structures incorporating these state-of-the-art GaInNAs junctions are projected.

  3. Thermodynamics, Entropy, Information and the Efficiency of Solar Cells

    E-Print Network [OSTI]

    Abrams, Zeev R.

    2012-01-01

    11 th E. C. Photovoltaic Solar Energy Conference, Montreal,of analytical expressions for solar cell fill factors.Solar Cells 7, 31. A. Luque and V. Andreev, Concentrator

  4. Photonic Design: From Fundamental Solar Cell Physics to Computational Inverse Design

    E-Print Network [OSTI]

    Miller, Owen Dennis

    2012-01-01

    4.9 Multi-junction solar cells more efficiently convertas concentrator or multi-junction solar cells, a similarFigure 4.9: Multi-junction solar cells more efficiently

  5. Efficient Solar Concentrators: Affordable Energy from Water and Sunlight

    SciTech Connect (OSTI)

    2010-01-01

    Broad Funding Opportunity Announcement Project: Teledyne is developing a liquid prism panel that tracks the position of the sun to help efficiently concentrate its light onto a solar cell to produce power. Typically, solar tracking devices have bulky and expensive mechanical moving parts that require a lot of power and are often unreliable. Teledyne’s liquid prism panel has no bulky and heavy supporting parts—instead it relies on electrowetting. Electrowetting is a process where an electric field is applied to the liquid to control the angle at which it meets the sunlight above and to control the angle of the sunlight to the focusing lensthe more direct the angle to the focusing lens, the more efficiently the light can be concentrated to solar panels and converted into electricity. This allows the prism to be tuned like a radio to track the sun across the sky and steer sunlight into the solar cell without any moving mechanical parts. This process uses very little power and requires no expensive supporting hardware or moving parts, enabling efficient and quiet rooftop operation for integration into buildings.

  6. NREL: News - NREL Research Earns Two Prestigious R&D 100 Awards

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

    approach to air conditioning, and a three-junction solar cell that holds the world efficiency record - both developed at the U.S. Department of Energy's (DOE) National Renewable...

  7. Key Physical Mechanisms in Nanostructured Solar Cells

    SciTech Connect (OSTI)

    Dr Stephan Bremner

    2010-07-21

    The objective of the project was to study both theoretically and experimentally the excitation, recombination and transport properties required for nanostructured solar cells to deliver energy conversion efficiencies well in excess of conventional limits. These objectives were met by concentrating on three key areas, namely, investigation of physical mechanisms present in nanostructured solar cells, characterization of loss mechanisms in nanostructured solar cells and determining the properties required of nanostructured solar cells in order to achieve high efficiency and the design implications.

  8. Master of Science in Engineering and Technology Management Engineering Management Concentration Management of Technology Concentration

    E-Print Network [OSTI]

    Selmic, Sandra

    Master of Science in Engineering and Technology Management Engineering Management Concentration Management of Technology Concentration Core Courses 21 Core Courses 6 FINC 577 Finance and Accounting for Non Management INEN 505 Manufacturing and Operations Analysis INEN 507 Engineering Administration Quantitative

  9. Gas diffusion electrode setup for catalyst testing in concentrated phosphoric acid at elevated temperatures

    SciTech Connect (OSTI)

    Wiberg, Gustav K. H. E-mail: m.arenz@chem.ku.dk; Fleige, Michael; Arenz, Matthias E-mail: m.arenz@chem.ku.dk

    2015-02-15

    We present a detailed description of the construction and testing of an electrochemical cell setup allowing the investigation of a gas diffusion electrode containing carbon supported high surface area catalysts. The setup is designed for measurements in concentrated phosphoric acid at elevated temperature, i.e., very close to the actual conditions in high temperature proton exchange membrane fuel cells (HT-PEMFCs). The cell consists of a stainless steel flow field and a PEEK plastic cell body comprising the electrochemical cell, which exhibits a three electrode configuration. The cell body and flow field are braced using a KF-25 vacuum flange clamp, which allows an easy assembly of the setup. As demonstrated, the setup can be used to investigate temperature dependent electrochemical processes on high surface area type electrocatalysts, but it also enables quick screening tests of HT-PEMFC catalysts under realistic conditions.

  10. Concentric ring flywheel without expansion separators

    DOE Patents [OSTI]

    Kuklo, T.C.

    1999-08-24

    A concentric ring flywheel wherein the adjacent rings are configured to eliminate the need for differential expansion separators between the adjacent rings. This is accomplished by forming a circumferential step on an outer surface of an inner concentric ring and forming a matching circumferential step on the inner surface of an adjacent outer concentric ring. During operation the circumferential steps allow the rings to differentially expand due to the difference in the radius of the rings without the formation of gaps therebetween, thereby eliminating the need for expansion separators to take up the gaps formed by differential expansion. 3 figs.

  11. NEW CONCEPTS FOR STATIC CONCENTRATION OF DIRECT AND DIFFUSE RADIATION A. Luque, J. Eguren, J.M. Ruiz, A. Cuevas, J. del Alamo, J.M. Gomez, M.

    E-Print Network [OSTI]

    del Alamo, Jesús A.

    NEW CONCEPTS FOR STATIC CONCENTRATION OF DIRECT AND DIFFUSE RADIATION A. Luque, J. Eguren, J en,ergy on a cell placed in a static concentrator of minimum entry aperture are derived at a cost estimat~ of $3.19 W/peak. 1. INTRODUCTION Conventional concentrating photovoltai~ devices require

  12. Shock initiation studies on high concentration hydrogen peroxide

    SciTech Connect (OSTI)

    Sheffield, Stephen A; Dattelbaum, Dana M; Stahl, David B; Gibson, L. Lee; Bartram, Brian D.

    2009-01-01

    Concentrated hydrogen peroxide (H{sub 2}O{sub 2}) has been known to detonate for many years. However, because of its reactivity and the difficulty in handling and confining it, along with the large critical diameter, few studies providing basic information about the initiation and detonation properties have been published. We are conducting a study to understand and quantify the initiation and detonation properties of highly concentrated H{sub 2}O{sub 2} using a gas-driven two-stage gun to produce well defined shock inputs. Multiple magnetic gauges are used to make in-situ measurements of the growth of reaction and subsequent detonation in the liquid. These experiments are designed to be one-dimensional to eliminate any difficulties that might be encountered with large critical diameters. Because of the concern of the reactivity of the H{sub 2}O{sub 2} with the confining materials, a remote loading system has been developed. The gun is pressurized, then the cell is filled and the experiment shot within less than three minutes. TV cameras are attached to the target so the cell filling can be monitored. Several experiments have been completed on {approx}98 wt % H{sub 2}O{sub 2}/H{sub 2}O mixtures; initiation has been observed in some experiments that shows homogeneous shock initiation behavior. The initial shock pressurizes and heats the mixture. After an induction time, a thermal explosion type reaction produces an evolving reactive wave that strengthens and eventually overdrives the first wave producing a detonation. From these measurements, we have determined unreacted Hugoniot information, times (distances) to detonation (Pop-plot points) that indicate low sensitivity, and detonation velocities of high concentration H{sub 2}O{sub 2}/H{sub 2}O solutions that agree with earlier estimates.

  13. Raising the Efficiency Ceiling with Multijunction III-V Concentrator Photovoltaics

    SciTech Connect (OSTI)

    King, R. R.; Boca, A.; Edmondson, K. M.; Romero, M. J.; Yoon, H.; Law, D. C.; Fetzer, C. M.; Haddad, M.; Zakaria, A.; Hong, W.; Mesropian, S.; Krut, D. D.; Kinsey, G. S.; Pien, R.; Sherif, R. A.; Karam, N. H.

    2008-01-01

    In this paper, we look at the question 'how high can solar cell efficiency go?' from both theoretical and experimental perspectives. First-principle efficiency limits are analyzed for some of the main candidates for high-efficiency multijunction terrestrial concentrator cells. Many of these cell designs use lattice-mismatched, or metamorphic semiconductor materials in order to tune subcell band gaps to the solar spectrum. Minority-carrier recombination at dislocations is characterized in GaInAs inverted metamorphic solar cells, with band gap ranging from 1.4 to 0.84 eV, by light I-V, electron-beam-induced current (EBIC), and cathodoluminescence (CL). Metamorphic solar cells with a 3-junction GaInP/ GaInAs/ Ge structure were the first cells to reach over 40% efficiency, with an independently confirmed efficiency of 40.7% (AM1.5D, low-AOD, 240 suns, 25 C). The high efficiency of present III-V multijunction cells now in high-volume production, and still higher efficiencies of next-generation cells, is strongly leveraging for low-cost terrestrial concentrator PV systems.

  14. Solar Energy Materials & Solar Cells 91 (2007) 15991610 Improving solar cell efficiency using photonic band-gap materials

    E-Print Network [OSTI]

    Dowling, Jonathan P.

    2007-01-01

    efficiency of solar cell devices without using concentrators. r 2007 Elsevier B.V. All rights reserved) solar energy conversion systems (or solar cells) are the most widely used power systems. HoweverSolar Energy Materials & Solar Cells 91 (2007) 1599­1610 Improving solar cell efficiency using

  15. What does stabilizing greenhouse gas concentrations mean?

    E-Print Network [OSTI]

    Jacoby, Henry D.; Schmalensee, Richard.; Reiner, David M.

    The MIT Emissions Prediction and Policy Analysis (EPPA) model is applied to an exploration of the national emissions obligations that would be required to stabilize atmospheric CO2 concentrations at levels now under active ...

  16. Advancing Concentrating Solar Power Research (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-02-01

    Researchers at the National Renewable Energy Laboratory (NREL) provide scientific, engineering, and analytical expertise to help advance innovation in concentrating solar power (CSP). This fact sheet summarizes how NREL is advancing CSP research.

  17. Concentrating Solar Power Research and Development

    Broader source: Energy.gov [DOE]

    In 2007, DOE issued the Concentrating Solar Power (CSP) Research and Development Funding Opportunity Announcement (FOA) managed by the SunShot Initiative. The following projects were selected under this competitive solicitation.

  18. Low-Cost Installation of Concentrating Photovoltaic

    E-Print Network [OSTI]

    allow for minimal disturbance of soil and ecosystem, and comprehensive full system delivery: April 2009 to March 2012 For more information, please contact: · Placing concentrating photovoltaic for this information or the researc

  19. Horticultural Science Concentration Program of Study

    E-Print Network [OSTI]

    Isaacs, Rufus

    Science Courses: 9 credits HRT 401(3) Advanced Horticultural Crop Physiology HRT 403 (3) Handling Horticultural Science Concentration Program of Study The Horticultural Science in biotechnology, plant breeding and genetics and graduate studies in plant sciences. University Requirements

  20. Project Profile: Concentrated Solar Thermoelectric Power

    Broader source: Energy.gov [DOE]

    The Rohsenow-Kendall Heat Transfer Lab at Massachusetts Institute of Technology(MIT), under the 2012 SunShot Concentrating Solar Power (CSP) R&D FOA, is developing concentrated solar thermoelectric generators (CSTEGs) for CSP systems. This innovative distributed solution contains no moving parts and converts heat directly into electricity. Thermal storage can be integrated into the system, creating a reliable and flexible source of electricity.

  1. Cell Stem Cell Stem Cell States, Fates,

    E-Print Network [OSTI]

    Peterson, Carsten

    Cell Stem Cell Review Stem Cell States, Fates, and the Rules of Attraction Tariq Enver,1 Martin Pera,2 Carsten Peterson,3,4 and Peter W. Andrews5,* 1The Molecular Haematology Unit, The Weatherall and their relationship to commitment to differ- entiate and lineage selection can be elucidated in terms of a landscape

  2. Joint measurement of current-phase relations and transport properties of hybrid junctions using a three junctions superconducting quantum interference device

    SciTech Connect (OSTI)

    Basset, J.; Delagrange, R.; Weil, R.; Kasumov, A.; Bouchiat, H.; Deblock, R.

    2014-07-14

    We propose a scheme to measure both the current-phase relation and differential conductance dI/dV of a superconducting junction, in the normal and the superconducting states. This is done using a dc Superconducting Quantum Interference Device with two Josephson junctions in parallel with the device under investigation and three contacts. As a demonstration, we measure the current-phase relation and dI/dV of a small Josephson junction and a carbon nanotube junction. In this latter case, in a regime where the nanotube is well conducting, we show that the non-sinusoidal current phase relation we find is consistent with the theory for a weak link, using the transmission extracted from the differential conductance in the normal state. This method holds great promise for future investigations of the current-phase relation of more exotic junctions.

  3. Cascade luminescent solar concentrators Sthy Flores Daorta, Antonio Proto, Roberto Fusco, Lucio Claudio Andreani, and Marco Liscidini

    E-Print Network [OSTI]

    a bourgeoning inter- est in photovoltaic (PV) research with the goal of reducing the cost of solar energy. To this end, most of the efforts have been focused on decreasing the cost of PV cells while main- taining the impact of PV cells on the total cost of energy production. The most common and utilized concentrators

  4. Thermal and electrical performance of a concentrating PV/Thermal collector: results from the ANU CHAPS collector

    E-Print Network [OSTI]

    , is a concentrating parabolic trough system that combines photovoltaic (PV) cells to produce electricity with thermal system, suitable for hot water and electricity generation for a home. Recently a second CHAPS system by an aluminium channel bonded to the cell tray rather than a copper pipe. The second and third CHAPS prototypes

  5. Toward microscale Cu,,In,Ga...Se2 solar cells for efficient conversion and optimized material usage: Theoretical evaluation

    E-Print Network [OSTI]

    Boyer, Edmond

    develop a model to predict the performances of microscale Cu In,Ga Se2 CIGS solar cells under concentrated limiting factor for concentration on CIGS solar cells. This model can be used to extract the value associated with the operation of microscale CIGS solar cells are studied. The optimum concentration ratio

  6. Energy Department Announces New Concentrating Solar Power Technology...

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

    Energy Department Announces New Concentrating Solar Power Technology Investments to American Industry, Universities Energy Department Announces New Concentrating Solar Power...

  7. High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application

    SciTech Connect (OSTI)

    Hubbard, Seth

    2012-09-12

    The High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrators project seeks to provide new photovoltaic cells for Concentrator Photovoltaics (CPV) Systems with higher cell efficiency, more favorable temperature coefficients and less sensitivity to changes in spectral distribution. The main objective of this project is to provide high efficiency III-V solar cells that will reduce the overall cost per Watt for power generation using CPV systems.This work is focused both on a potential near term application, namely the use of indium arsenide (InAs) QDs to spectrally "tune" the middle (GaAs) cell of a SOA triple junction device to a more favorable effective bandgap, as well as the long term goal of demonstrating intermediate band solar cell effects. The QDs are confined within a high electric field i-region of a standard GaAs solar cell. The extended absorption spectrum (and thus enhanced short circuit current) of the QD solar cell results from the increase in the sub GaAs bandgap spectral response that is achievable as quantum dot layers are introduced into the i-region. We have grown InAs quantum dots by OMVPE technique and optimized the QD growth conditions. Arrays of up to 40 layers of strain balanced quantum dots have been experimentally demonstrated with good material quality, low residual stain and high PL intensity. Quantum dot enhanced solar cells were grown and tested under simulated one sun AM1.5 conditions. Concentrator solar cells have been grown and fabricated with 5-40 layers of QDs. Testing of these devices show the QD cells have improved efficiency compared to baseline devices without QDs. Device modeling and measurement of thermal properties were performed using Crosslight APSYS. Improvements in a triple junction solar cell with the insertion of QDs into the middle current limiting junction was shown to be as high as 29% under one sun illumination for a 10 layer stack QD enhanced triple junction solar cell. QD devices have strong potential for net gains in efficiency at high concentration.

  8. Plasma polychlorinated biphenyl concentrations and immune function in postmenopausal women

    SciTech Connect (OSTI)

    Spector, June T.; De Roos, Anneclaire J.; Ulrich, Cornelia M.; Sheppard, Lianne; Sjoedin, Andreas; Wener, Mark H.; Wood, Brent; and others

    2014-05-01

    Background: Polychlorinated biphenyl (PCB) exposure has been associated with non-Hodgkin lymphoma in several studies, and the immune system is a potential mediator. Objectives: We analyzed associations of plasma PCBs with immune function measures. We hypothesized that higher plasma PCB concentrations are associated with lower immune function cross-sectionally, and that increases in PCB concentrations over a one year period are associated with decreases in immune function. Methods: Plasma PCB concentrations and immune function [natural killer (NK) cell cytotoxicity and PHA-induced T-lymphocyte proliferation (PHA-TLP)] were measured at baseline and one year in 109 postmenopausal overweight women participating in an exercise intervention study in the Seattle, Washington (USA) area. Mixed models, with adjustment for body mass index and other potential confounders, were used to estimate associations of PCBs with immune function cross-sectionally and longitudinally. Results: Associations of PCBs with immune function measures differed across groups of PCBs (e.g., medium- and high-chlorinated and dioxin-like [mono-ortho-substituted]) and by the time frame for the comparison (cross-sectional vs. longitudinal). Higher concentrations of medium- and high-chlorinated PCBs were associated with higher PHA-TLP cross-sectionally but not longitudinally. The mean decrease in 0.5 µg/mL PHA-TLP/50.0 pmol/g-lipid increase in dioxin-like PCBs over one year was 51.6 (95% confidence interval 2.7, 100.5; P=0.039). There was no association between plasma PCBs and NK cytotoxicity. Conclusions: These results do not provide strong evidence of impaired cellular immunity from PCB exposure. Larger longitudinal studies with greater variability in PCB exposures are needed to further examine temporal associations of PCBs with immune function. - Highlights: • Plasma PCBs and immune function were measured in 109 women at baseline and one year. • Immune measures included T lymphocyte proliferation (TLP) and NK cell cytotoxicity. • Higher-chlorinated PCBs were positively associated with TLP in cross-section. • An increase in dioxin-like PCBs was associated with a decrease in TLP over one year. • We did not find strong evidence of impaired cellular immunity from PCB exposure.

  9. Denaturation of DNA at high salt concentrations

    E-Print Network [OSTI]

    Arghya Maity; Amar Singh; Navin Singh

    2015-08-19

    Cations present in the solution are important for the stability of two negative strands of DNA molecules. Experimental as well as theoretical results show that the DNA molecule is more stable as the concentration of salt (or cations) increases. It is known that the two strands of DNA molecule carry negative charge due to phosphate group along the strands. These cations act as a shielding particles to the two like charge strands. Recently, in an experiment it is shown that there is a critical value in the concentration of salts (or cations) that can stabilize the helical structure of DNA. If one add more salt in the solution beyond this critical value, the stability of the DNA molecule will disrupt. In this work we study the stability of DNA molecules at higher concentrations. How the stability at higher concentration can be explained through some theoretical calculations is the aim of this manuscript. We consider the PBD model with proper modifications that can explain the negative stability of the molecule at higher concentration. Our findings are in close match with the experimental results.

  10. Automated micro-tracking planar solar concentrators

    E-Print Network [OSTI]

    Hallas, Justin Matthew

    2011-01-01

    PV cell behind each lens tracking the sun with only lateralclimbing required for tracking the sun, and experimentalin a fixed frame tracking the sun with only micro-tracking.

  11. Spectroscopic detection of nitrogen concentrations in sagebrush

    SciTech Connect (OSTI)

    J. J. MITCHELL; N. F. GLENN; T.T. SANKEY; D. R. DERRYBERRY; R. C. HRUSKA; M. O. Anderson

    2012-07-01

    The ability to estimate foliar nitrogen (N) in semi-arid landscapes can yield information on nutritional status and improve our limited understanding of controls on canopy photosynthesis. We examined two spectroscopic methods for estimating sagebrush dried leaf and live shrub N content: first derivative reflectance (FDR) and continuum removal. Both methods used partial least squares (PLS) regression to select wavebands most significantly correlated with N concentrations in the samples. Sagebrush dried leaf spectra produced PLS models (R2 = 0.76–0.86) that could predict N concentrations within the dataset more accurately than PLS models generated from live shrub spectra (R2 = 0.41–0.63). Inclusion of wavelengths associated with leaf water in the FDR transformations appeared to improve regression results. Findings are encouraging and warrant further exploration into sagebrush reflectance spectra to characterize N concentrations.

  12. Concentration of perrhenate and pertechnetate solutions

    DOE Patents [OSTI]

    Knapp, Furn F. (Oak Ridge, TN); Beets, Arnold L. (Clinton, TN); Mirzadeh, Saed (Knoxville, TN); Guhlke, Stefan (Bonn, DE)

    1998-01-01

    A method of preparing a concentrated solution of a carrier-free radioisotope which includes the steps of: a. providing a generator column loaded with a composition containing a parent radioisotope; b. eluting the generator column with an eluent solution which includes a salt of a weak acid to elute a target daughter radioisotope from the generator column in a first eluate. c. eluting a cation-exchange column with the first eluate to exchange cations of the salt for hydrogen ions and to elute the target daughter radioisotope and a weak acid in a second eluate; d. eluting an anion-exchange column with the second eluate to trap and concentrate the target daughter radioisotope and to elute the weak acid solution therefrom; and e. eluting the concentrated target daughter radioisotope from the anion-exchange column with a saline solution.

  13. Concentration of perrhenate and pertechnetate solutions

    DOE Patents [OSTI]

    Knapp, F.F.; Beets, A.L.; Mirzadeh, S.; Guhlke, S.

    1998-03-17

    A method is described for preparing a concentrated solution of a carrier-free radioisotope which includes the steps of: (a) providing a generator column loaded with a composition containing a parent radioisotope; (b) eluting the generator column with an eluent solution which includes a salt of a weak acid to elute a target daughter radioisotope from the generator column in a first eluate; (c) eluting a cation-exchange column with the first eluate to exchange cations of the salt for hydrogen ions and to elute the target daughter radioisotope and a weak acid in a second eluate; (d) eluting an anion-exchange column with the second eluate to trap and concentrate the target daughter radioisotope and to elute the weak acid solution therefrom; and (e) eluting the concentrated target daughter radioisotope from the anion-exchange column with a saline solution. 1 fig.

  14. Wide range radioactive gas concentration detector

    DOE Patents [OSTI]

    Anderson, David F. (Los Alamos, NM)

    1984-01-01

    A wide range radioactive gas concentration detector and monitor which is capable of measuring radioactive gas concentrations over a range of eight orders of magnitude. The device of the present invention is designed to have an ionization chamber which is sufficiently small to give a fast response time for measuring radioactive gases but sufficiently large to provide accurate readings at low concentration levels. Closely spaced parallel plate grids provide a uniform electric field in the active region to improve the accuracy of measurements and reduce ion migration time so as to virtually eliminate errors due to ion recombination. The parallel plate grids are fabricated with a minimal surface area to reduce the effects of contamination resulting from absorption of contaminating materials on the surface of the grids. Additionally, the ionization chamber wall is spaced a sufficient distance from the active region of the ionization chamber to minimize contamination effects.

  15. Resonance-shifting luminescent solar concentrators

    DOE Patents [OSTI]

    Giebink, Noel Christopher; Wiederrecht, Gary P; Wasielewski, Michael R

    2014-09-23

    An optical system and method to overcome luminescent solar concentrator inefficiencies by resonance-shifting, in which sharply directed emission from a bi-layer cavity into a glass substrate returns to interact with the cavity off-resonance at each subsequent reflection, significantly reducing reabsorption loss en route to the edges. In one embodiment, the system comprises a luminescent solar concentrator comprising a transparent substrate, a luminescent film having a variable thickness; and a low refractive index layer disposed between the transparent substrate and the luminescent film.

  16. Development of the SEA Corporation Powergrid{trademark} photovoltaic concentrator

    SciTech Connect (OSTI)

    Kaminar, N.; Curchod, D.; Daroczi, S.; Walpert, M.; Sahagian, J.; Pepper, J. [Photovoltaics International, LLC, Sunnyvale, CA (United States)

    1998-03-01

    This report covers the three phase effort to bring the SEA Corporation`s Powergrid{trademark} from the concept stage to pilot production. The three phases of this contract covered component development, prototype module development, and pilot line production. The Powergrid is a photovoltaic concentrator that generates direct current electricity directly from sunlight using a linear Fresnel lens. Analysis has shown that the Powergrid has the potential to be very low cost in volume production. Before the start of the project, only proof of concept demonstrations of the components had been completed. During the project, SEA Corporation developed a low cost extruded Fresnel lens, a low cost receiver assembly using one sun type cells, a low cost plastic module housing, a single axis tracking system and frame structure, and pilot production equipment and techniques. In addition, an 800 kW/yr pilot production rate was demonstrated and two 40 kW systems were manufactured and installed.

  17. History Concentration Planning Worksheet (Updated Spring 2015)

    E-Print Network [OSTI]

    Cantlon, Jessica F.

    History Concentration Planning Worksheet (Updated Spring 2015) Name: Phone: Class: ______ Student) Gateway to History (HIS 100) 1. Pre-1800 Post-1800 1. 1. 2. 2. Geographic Distribution 1. 2. 3. Focus: _______________________ REQUIREMENTS #12;History Major Requirements (in addition to the courses on the front, history

  18. Denaturation of DNA at high salt concentrations

    E-Print Network [OSTI]

    Maity, Arghya; Singh, Navin

    2015-01-01

    Cations present in the solution are important for the stability of two negative strands of DNA molecules. Experimental as well as theoretical results show that the DNA molecule is more stable as the concentration of salt (or cations) increases. It is known that the two strands of DNA molecule carry negative charge due to phosphate group along the strands. These cations act as a shielding particles to the two like charge strands. Recently, in an experiment it is shown that there is a critical value in the concentration of salts (or cations) that can stabilize the helical structure of DNA. If one add more salt in the solution beyond this critical value, the stability of the DNA molecule will disrupt. In this work we study the stability of DNA molecules at higher concentrations. How the stability at higher concentration can be explained through some theoretical calculations is the aim of this manuscript. We consider the PBD model with proper modifications that can explain the negative stability of the molecule a...

  19. Mixing liquid holding tanks for uniform concentration

    SciTech Connect (OSTI)

    Sprouse, K.M.

    1988-01-01

    Achieving uniform concentration within liquid holding tanks can often times be a difficult task for the nuclear chemical process industry. This is due to the fact that nuclear criticality concerns require these tanks to be designed with high internal aspect ratios such that the free movement of fluid is greatly inhibited. To determine the mixing times required to achieve uniform concentrations within these tanks, an experimental program was conducted utilizing pencil tanks, double-pencil tanks, and annular tanks of varying geometries filled with salt-water solutions (simulant for nitric acid actinide solutions). Mixing was accomplished by air sparging and/or pump recirculation. Detailed fluid mechanic mixing models were developed --from first principles--to analyze and interpret the test results. These nondimensional models show the functionality of the concentration inhomogeneity (defined as the relative standard deviation of the true concentration within the tank) in relationship to the characteristic mixing time--among other variables. The results can be readily used to scale tank geometries to sizes other than those studied here.

  20. High concentrations of phosphate and nitrate in

    E-Print Network [OSTI]

    Langendoen, Koen

    the concentration of phosphate in the feedwater ­ the water that has to be purified ­ as well as the total nitrite content in the filtered water ­ the water that is already purified ­ is also measured, in order to ensure for waste water treatment plants. Moreover, it also means better purification results and a decreased risk

  1. Concentration of Eigenfunctions in Rough Media

    E-Print Network [OSTI]

    Smith, Hart F.

    Concentration of Eigenfunctions in Rough Media Hart F. Smith Department of Mathematics University of Washington, Seattle UC Irvine - June 18, 2012 Hart F. Smith Eigenfunctions in Rough Media #12;M = compact L2(M) (p) ( p 2 ) Hart F. Smith Eigenfunctions in Rough Media #12;M = compact manifold with volume

  2. Project Profile: Scattering Solar Thermal Concentrators

    Broader source: Energy.gov [DOE]

    Pennsylvania State University, under the 2012 SunShot Concentrating Solar Power (CSP) R&D FOA, is designing and testing a novel solar collector system that relies on stationary optics, avoiding the need for mirror movement. The system is capable of achieving optical performance equal to state-of-the-art parabolic trough systems, but at a lower cost.

  3. Concentrating Solar Power Commercial Application Study

    SciTech Connect (OSTI)

    none,

    2009-10-01

    This report has been prepared in response to section 603(b) of the Energy Independence and Security Act of 2007, (Pub. L. No. 110-140), which states that “…the Secretary of Energy shall transmit to Congress a report on the results of a study on methods to reduce the amount of water consumed by concentrating solar power systems.”

  4. Low chemical concentrating steam generating cycle

    DOE Patents [OSTI]

    Mangus, James D. (Greensburg, PA)

    1983-01-01

    A steam cycle for a nuclear power plant having two optional modes of operation. A once-through mode of operation uses direct feed of coolant water to an evaporator avoiding excessive chemical concentration buildup. A recirculation mode of operation uses a recirculation loop to direct a portion of flow from the evaporator back through the evaporator to effectively increase evaporator flow.

  5. Magnetic flux concentrations from turbulent stratified convection

    E-Print Network [OSTI]

    Käpylä, P J; Kleeorin, N; Käpylä, M J; Rogachevskii, I

    2015-01-01

    (abridged) Context: The mechanisms that cause the formation of sunspots are still unclear. Aims: We study the self-organisation of initially uniform sub-equipartition magnetic fields by highly stratified turbulent convection. Methods: We perform simulations of magnetoconvection in Cartesian domains that are $8.5$-$24$ Mm deep and $34$-$96$ Mm wide. We impose either a vertical or a horizontal uniform magnetic field in a convection-driven turbulent flow. Results: We find that super-equipartition magnetic flux concentrations are formed near the surface with domain depths of $12.5$ and $24$ Mm. The size of the concentrations increases as the box size increases and the largest structures ($20$ Mm horizontally) are obtained in the 24 Mm deep models. The field strength in the concentrations is in the range of $3$-$5$ kG. The concentrations grow approximately linearly in time. The effective magnetic pressure measured in the simulations is positive near the surface and negative in the bulk of the convection zone. Its ...

  6. Biomedical Engineering Graduate Concentration Fall 2014 Biomechanics

    E-Print Network [OSTI]

    Eustice, Ryan

    Biomedical Engineering Graduate Concentration ­ Fall 2014 Biomechanics Advisor: Scott Hollister, Ph.D. BIOMECHANICS (select one course): BIOMEDE 456 Tissue Mechanics (3) (I) BIOMEDE 476 Biofluid Mechanics (4) (II) GENERAL (both courses are required): BIOMEDE 500 Biomedical Engineering Seminar (1) (I,II) BIOMEDE 550

  7. Biomedical Engineering Graduate Concentration Fall 2014 Biomaterials

    E-Print Network [OSTI]

    Eustice, Ryan

    Biomedical Engineering Graduate Concentration ­ Fall 2014 Biomaterials Advisor: David Kohn, Ph.D. BIOMATERIALS: BIOMEDE 410 Design and Applications of Biomaterials (3) (I) GENERAL (both courses are required): BIOMEDE 500 Biomedical Engineering Seminar (1) (I,II) BIOMEDE 550 Ethics and Enterprise (1) (I) BIOMEDICAL

  8. Biomedical Engineering Graduate Concentration Fall 2014 Bioelectrical

    E-Print Network [OSTI]

    Eustice, Ryan

    Biomedical Engineering Graduate Concentration ­ Fall 2014 Bioelectrical Advisor: Cynthia Chestek, Ph.D. BIOELECTRICAL: BIOMEDE 417 Electrical Biophysics (4) (II) GENERAL (both courses are required): BIOMEDE 500 Biomedical Engineering Seminar (1) (I,II) BIOMEDE 550 Ethics and Enterprise (1) (I) BIOMEDICAL

  9. Centrifugal Filter Devices FOR CONCENTRATION AND PURIFICATION

    E-Print Network [OSTI]

    Kirschner, Marc W.

    Centricon® Plus-70 Centrifugal Filter Devices FOR CONCENTRATION AND PURIFICATION OF BIOLOGICAL-70 centrifugal filter is a disposable, single-use device designed for rapid processing of aqueous biological solu- tions in volumes ranging from 15 to 70 mL. It is compatible with swinging-bucket centrifuges

  10. Molecular Cell, Volume 50 Supplemental Information

    E-Print Network [OSTI]

    Komander, David

    point mutants on NF-B activity at different concentration. (B) HA-IP and inputs on U2OS/NOD2 cells to show the low levels of NOD2 expressed under non-induced conditions. (C) Immunofluorescence analysis of U2OS/NOD2 cells with and without transfected vector expressing the HA-tag shows that the level

  11. The Dependence of Electrical Properties on Miscut Orientation in Direct Bonded III-V Solar Cell Layers

    E-Print Network [OSTI]

    Seal, Mark K.

    2015-01-01

    GaInAs concentrator solar cells with 44.7% efficiency",wafer-bonded tandem solar cells”, 38 th IEEE Photovoltaicfor Wafer-Bonded Tandem Solar Cells”, ECS Trans. 50 99 (

  12. Modeled atmospheric radon concentrations from uranium mines

    SciTech Connect (OSTI)

    Droppo, J.G.

    1985-04-01

    Uranium mining and milling operations result in the release of radon from numerous sources of various types and strengths. The US Environmental Protection Agency (EPA) under the Clean Air Act, is assessing the health impact of air emissions of radon from underground uranium mines. In this case, the radon emissions may impact workers and residents in the mine vicinity. To aid in this assessment, the EPA needs to know how mine releases can affect the radon concentrations at populated locations. To obtain this type of information, Pacific Northwest Laboratory used the radon emissions, release characteristics and local meterological conditions for a number of mines to model incremental radon concentrations. Long-term, average, incremental radon concentrations were computed based on the best available information on release rates, plume rise parameters, number and locations of vents, and local dispersion climatology. Calculations are made for a model mine, individual mines, and multiple mines. Our approach was to start with a general case and then consider specific cases for comparison. A model underground uranium mine was used to provide definition of the order of magnitude of typical impacts. Then computations were made for specific mines using the best mine-specific information available for each mine. These case study results are expressed as predicted incremental radon concentration contours plotted on maps with local population data from a previous study. Finally, the effect of possible overlap of radon releases from nearby mines was studied by calculating cumulative radon concentrations for multiple mines in a region with many mines. The dispersion model, modeling assumptions, data sources, computational procedures, and results are documented in this report. 7 refs., 27 figs., 18 tabs.

  13. Dynamic control of catalysis within biological cells

    E-Print Network [OSTI]

    Biman Jana; Biman Bagchi

    2011-05-26

    We develop a theory of enzyme catalysis within biological cells where the substrate concentration [S](t) is time dependent, in contrast to the Michaelis-Menten theory that assumes a steady state. We find that the time varying concentration can combine, in a non-linear way, with the ruggedness of the free energy landscape of enzymes (discovered both in single molecule studies and in simulations) to provide a highly efficient switch (or, bifurcation) between two catalytically active states, at a critical substrate concentration. This allows a dynamic control of product synthesis in cell.

  14. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    the manufacturing of solar cells and photovoltaic arrays hasfor providing us Photovoltaic cells, lumines- cent materialsthe currently available photovoltaic cells. The property of

  15. Solar kinetics` photovoltaic concentrator module and tracker development

    SciTech Connect (OSTI)

    White, D.L.; Howell, B. [Solar Kinetics, Inc., Dallas, TX (United States)

    1995-11-01

    Solar Kinetics, Inc., has been developing a point-focus concentrating photovoltaic module and tracker system under contract to Sandia National Laboratories. The primary focus of the contract was to achieve a module design that was manufacturable and passed Sandia`s environmental testing. Nine modules of two variations were assembled, tested, and characterized in Phase 1, and results of these tests were promising, with module efficiency approaching the theoretical limit achievable with the components used. The module efficiency was 11.9% at a solar irradiance of 850 W/m{sup 2} and an extrapolated cell temperature of 25{degrees}C. Improvements in module performance are anticipated as cell efficiencies meet their expectations. A 2-kW tracker and controller accommodating 20 modules was designed, built, installed, and operated at Solar Kinetics` test site. The drive used many commercially available components in an innovative arrangement to reduce cost and increase reliability. Backlash and bearing play were controlled by use of preloaded, low slip-stick, synthetic slide bearings. The controller design used a standard industrial programmable logic controller to perform ephemeris calculations, operate the actuators, and monitor encoders.

  16. High-Efficiency Solar Cells for Large-Scale Electricity Generation

    SciTech Connect (OSTI)

    Kurtz, S.; Olson, J.; Geisz, J.; Friedman, D.; McMahon, W.; Ptak, A.; Wanlass, M.; Kibbler, A.; Kramer, C.; Bertness, K.; Ward, S.; Duda, A.; Young, M.; Carapella, J.; Steiner, M.

    2008-09-26

    One strategy for helping the solar industry to grow faster is to use very high efficiency cells under concentrating optics. By using lenses or mirrors to concentrate the light, very small solar cells can be used, reducing the amount of semiconductor material and allowing use of higher efficiency cells, which are now >40% efficient.

  17. Platinum-ruthenium-palladium fuel cell electrocatalyst

    DOE Patents [OSTI]

    Gorer, Alexander

    2006-02-07

    A catalyst suitable for use in a fuel cell, especially as an anode catalyst, that contains platinum at a concentration that is between about 20 and about 60 atomic percent, ruthenium at a concentration that is between about 20 and about 60 atomic percent, palladium at a concentration that is between about 5 and about 45 atomic percent, and having an atomic ratio of platinum to ruthenium that is between about 0.7 and about 1.2. Alternatively, the catalyst may contain platinum at a concentration that is between about 25 and about 50 atomic percent, ruthenium at a concentration that is between about 25 and about 55 atomic percent, palladium at a concentration that is between about 5 and about 45 atomic percent, and having a difference between the concentrations of ruthenium and platinum that is no greater than about 20 atomic percent.

  18. Trace element concentrations in melanotic swine

    SciTech Connect (OSTI)

    Sherman, R.M.; Parkinson, T.F.; Veit, H.P.

    1983-10-01

    A number of investigations have been made on the role of certain trace elements in oncogenesis. In prior work, it was found that manganese and zinc concentrations in human skin cancers differed markedly from the values in normal tissue./sub 1/ The purpose of the present research was to determine trace element concentrations in skin and other tissues of normal and melanotic miniature swine. In-vivo determinations of skin tissue were carried out using x-ray fluorescence analysis (XRFA) while tissue biopsies were measured using instrumental neutron activation analysis (INAA). If significant differences between normal and cancerous skin tissues can be established, the former method should prove valuable as a rapid noninvasive diagnostic method.

  19. Cast Stone Formulation At Higher Sodium Concentrations

    SciTech Connect (OSTI)

    Fox, K. M.; Roberts, K. A.; Edwards, T. B.

    2014-02-28

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leachability indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The thermal analyses completed in this study provide some preliminary insight, although the l

  20. Cast Stone Formulation At Higher Sodium Concentrations

    SciTech Connect (OSTI)

    Fox, K. M.; Edwards, T. A.; Roberts, K. B.

    2013-10-02

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leach indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The thermal analyses completed in this study provide some preliminary insight, although the limited

  1. Cast Stone Formulation At Higher Sodium Concentrations

    SciTech Connect (OSTI)

    Fox, K. M.; Roberts, K. A.; Edwards, T. B.

    2013-09-17

    A low temperature waste form known as Cast Stone is being considered to provide supplemental Low Activity Waste (LAW) immobilization capacity for the Hanford site. Formulation of Cast Stone at high sodium concentrations is of interest since a significant reduction in the necessary volume of Cast Stone and subsequent disposal costs could be achieved if an acceptable waste form can be produced with a high sodium molarity salt solution combined with a high water to premix (or dry blend) ratio. The objectives of this study were to evaluate the factors involved with increasing the sodium concentration in Cast Stone, including production and performance properties and the retention and release of specific components of interest. Three factors were identified for the experimental matrix: the concentration of sodium in the simulated salt solution, the water to premix ratio, and the blast furnace slag portion of the premix. The salt solution simulants used in this study were formulated to represent the overall average waste composition. The cement, blast furnace slag, and fly ash were sourced from a supplier in the Hanford area in order to be representative. The test mixes were prepared in the laboratory and fresh properties were measured. Fresh density increased with increasing sodium molarity and with decreasing water to premix ratio, as expected given the individual densities of these components. Rheology measurements showed that all of the test mixes produced very fluid slurries. The fresh density and rheology data are of potential value in designing a future Cast Stone production facility. Standing water and density gradient testing showed that settling is not of particular concern for the high sodium compositions studied. Heat of hydration measurements may provide some insight into the reactions that occur within the test mixes, which may in turn be related to the properties and performance of the waste form. These measurements showed that increased sodium concentration in the salt solution reduced the time to peak heat flow, and reducing the amount of slag in the premix increased the time to peak heat flow. These observations may help to describe some of the cured properties of the samples, in particular the differences in compressive strength observed after 28 and 90 days of curing. Samples were cured for at least 28 days at ambient temperature in the laboratory prior to cured properties analyses. The low activity waste form for disposal at the Hanford Site is required to have a compressive strength of at least 500 psi. After 28 days of curing, several of the test mixes had mean compressive strengths that were below the 500 psi requirement. Higher sodium concentrations and higher water to premix ratios led to reduced compressive strength. Higher fly ash concentrations decreased the compressive strength after 28 days of curing. This may be explained in that the cementitious phases matured more quickly in the mixes with higher concentrations of slag, as evidenced by the data for the time to peak heat generation. All of the test mixes exhibited higher mean compressive strengths after 90 days of curing, with only one composition having a mean compressive strength of less than 500 psi. Leach indices were determined for the test mixes for contaminants of interest. The leaching performance of the mixes evaluated in this study was not particularly sensitive to the factors used in the experimental design. This may be beneficial in demonstrating that the performance of the waste form is robust with respect to changes in the mix composition. The results of this study demonstrate the potential to achieve significantly higher waste loadings in Cast Stone and other low temperature, cementitious waste forms. Additional work is needed to elucidate the hydration mechanisms occurring in Cast Stone formulated with highly concentrated salt solutions since these reactions are responsible for determining the performance of the cured waste form. The thermal analyses completed in this study provide some preliminary insight, although the limited

  2. Material for a luminescent solar concentrator

    DOE Patents [OSTI]

    Andrews, L.J.

    1984-01-01

    A material for use in a luminescent solar concentrator, formed by ceramitizing the luminescent ion Cr/sup 3 +/ with a transparent ceramic glass containing mullite. The resultant material has tiny Cr/sup 3 +/-bearing crystallites dispersed uniformly through an amorphous glass. The invention combines the high luminescent efficiency of Cr/sup 3 +/ in the crystalline phase with the practical and economical advantages of glass technology.

  3. DNA Concentration By UV Spectrophotometry Measure Absorption

    E-Print Network [OSTI]

    Aris, John P.

    DNA Concentration By UV Spectrophotometry Measure Absorption: 1. Dilute DNA to 0.5 to 50 µg/ml in TE buffer or dH2O. Plan to use a quartz cuvette or a UV-transparent plastic (disposable) cuvette (1 2. Measure absorption at 260 nm (A260). Start by zeroing instrument with TE buffer or dH2O alone

  4. Concentrating Solar Power Projects | Department of Energy

    Energy Savers [EERE]

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on DeliciousMathematics And StatisticsProgram ManagerCorridor6YellowstonePermittingComputer System RetirementConcentrating

  5. Concentrating Solar Power Newsletter | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative Fuels DataEnergy Webinar:I DueBETOofforCompany TemplateCompletedConcentrating

  6. Differences in response of Zymomonas mobilis and Saccharomyces cerevisiae to change in extracellular ethanol concentration

    SciTech Connect (OSTI)

    Hobley, T.J.; Pamment, N.B. . Dept. of Chemical Engineering)

    1994-01-20

    In high cell density batch fermentations, Zymomonas mobilis produced 91 g L[sup [minus]1] ethanol in 90 minutes but culture viability fell significantly. Similar viability losses in rapid fermentations by yeast have recently been shown to be attributable in part to the high rate of change of the extracellular ethanol concentration. However, in simulated rapid fermentations in which ethanol was pumped continuously to low cell density Z. mobilis suspensions, increases in the rate of change of ethanol concentration in the range 21--83 L[sup [minus]1]h[sup [minus]1] did not lead to accelerated viability losses. The lag phase of Zymomonas cultures exposed to a 30-g L[sup [minus]1] step change in ethanol concentration was much shorter than that of Saccharomyces cerevisiae, providing evidence that the comparative insensitivity of Zymomonas to high rates of change of ethanol concentration is due to its ability to adapt to changes in ethanol concentration more rapidly than yeast.

  7. EE Times: Semi News Groups claim breakthroughs in solar cells

    E-Print Network [OSTI]

    Rogers, John A.

    -based, multi-junction solar cells. Module cost is minimized by using high concentration ratio. XEE Times: Semi News Groups claim breakthroughs in solar cells Mark LaPedus Page 1 of 2 EE Times (05 separately claimed breakthroughs in solar cell production. Gallium arsenide (GaAs) and related compounds

  8. National Laboratory Concentrating Solar Power Research and Development...

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

    National Laboratory Concentrating Solar Power Research and Development National Laboratory Concentrating Solar Power Research and Development This fact sheet describes the current...

  9. 2014 SunShot Initiative Portfolio Book: Concentrating Solar Power...

    Energy Savers [EERE]

    Concentrating Solar Power 2014 SunShot Initiative Portfolio Book: Concentrating Solar Power The 2014 SunShot Initiative Portfolio Book outlines the progress towards the goals...

  10. 2014 SunShot Initiative Concentrating Solar Power Subprogram...

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

    Concentrating Solar Power Subprogram Overview 2014 SunShot Initiative Concentrating Solar Power Subprogram Overview These slides correspond to a presentation given by SunShot...

  11. World's Largest Concentrating Solar Power Plant Opens in California...

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

    World's Largest Concentrating Solar Power Plant Opens in California World's Largest Concentrating Solar Power Plant Opens in California February 19, 2014 - 12:00am Addthis Ivanpah,...

  12. Concentrating Solar Power: Best Practices Handbook for the Collection...

    Open Energy Info (EERE)

    Concentrating Solar Power: Best Practices Handbook for the Collection and Use of Solar Resource Data Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Concentrating Solar...

  13. Project Profile: Novel Thermal Storage Technologies for Concentrating...

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

    Storage Technologies for Concentrating Solar Power Generation Project Profile: Novel Thermal Storage Technologies for Concentrating Solar Power Generation Lehigh logo Lehigh...

  14. Transient fluctuations of intracellular zinc ions in cell proliferation

    SciTech Connect (OSTI)

    Li, Yuan; Maret, Wolfgang; Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX 77555

    2009-08-15

    Zinc is essential for cell proliferation, differentiation, and viability. When zinc becomes limited for cultured cells, DNA synthesis ceases and the cell cycle is arrested. The molecular mechanisms of actions of zinc are believed to involve changes in the availability of zinc(II) ions (Zn{sup 2+}). By employing a fluorescent Zn{sup 2+} probe, FluoZin-3 acetoxymethyl ester, intracellular Zn{sup 2+} concentrations were measured in undifferentiated and in nerve growth factor (NGF)-differentiated rat pheochromocytoma (PC12) cells. Intracellular Zn{sup 2+} concentrations are pico- to nanomolar in PC12 cells and are higher in the differentiated than in the undifferentiated cells. When following cellular Zn{sup 2+} concentrations for 48 h after the removal of serum, a condition that is known to cause cell cycle arrest, Zn{sup 2+} concentrations decrease after 30 min but, remarkably, increase after 1 h, and then decrease again to about one half of the initial concentration. Cell proliferation, measured by an MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay, decreases after both serum starvation and zinc chelation. Two peaks of Zn{sup 2+} concentrations occur within one cell cycle: one early in the G1 phase and the other in the late G1/S phase. Thus, fluctuations of intracellular Zn{sup 2+} concentrations and established modulation of phosphorylation signaling, via an inhibition of protein tyrosine phosphatases at commensurately low Zn{sup 2+} concentrations, suggest a role for Zn{sup 2+} in the control of the cell cycle. Interventions targeted at these picomolar Zn{sup 2+} fluctuations may be a way of controlling cell growth in hyperplasia, neoplasia, and diseases associated with aberrant differentiation.

  15. Induction of cyclin D1 by submicromolar concentrations of arsenite in human epidermal keratinocytes

    SciTech Connect (OSTI)

    Hwang, B.-J. [Department of Chemistry, City College of the City University of New York, Convent Avenue and 138th Street, New York, NY 10031 (United States); Utti, Charles [Department of Chemistry, City College of the City University of New York, Convent Avenue and 138th Street, New York, NY 10031 (United States); Steinberg, Mark [Department of Chemistry, City College of the City University of New York, Convent Avenue and 138th Street, New York, NY 10031 (United States)]. E-mail: marste@sci.ccny.cuny.edu

    2006-12-01

    Arsenic is a prevalent environmental carcinogen but arsenic is not directly mutagenic and the mechanism by which arsenite brings about oncogenic transformation is poorly understood. To gain insight into the oncogenic properties of arsenic, we studied the expression of cyclin D1 in cultured human epidermal keratinocytes treated with submicromolar concentrations of sodium arsenite. Arsenite at concentrations between 200 and 800 nM over a 3-day period brought about an increase in cell growth rate. Uptake of the vital stain, neutral red, arsenite at 200 and 400 nM concentrations brought about a parallel increase in cell viability over the same treatment period. Analysis of cell cycle parameters by flow cytometry showed that the growth stimulation was accompanied by a concomitant shift from the G1 into the S/G2 cell cycle compartment in the arsenite-treated cells. Real-time PCR analysis of cyclin D1 transcription showed that there was an induction of more than three-fold in cells exposed to 400 nM arsenite for 3 days. Quantitation of cyclin D levels in Western blots showed that arsenite treatment caused a time-dependent induction of cyclin D proteins representing an induction of about 2.0-fold after a 7 day treatment period. Electrophoretic mobility shift assays (EMSA) showed that arsenite also stimulated binding of the transcription factors, AP1 and CREBP to their respective binding motifs within 3 days. This supports a mechanism of oncogenesis based on persistent upregulation of D type cyclins leading to a concomitant loss of G1/S checkpoint control.

  16. Crystal structure of a concentrative nucleoside transporter from Vibrio cholerae at 2.4;#8201;Å

    SciTech Connect (OSTI)

    Johnson, Zachary Lee; Cheong, Cheom-Gil; Lee, Seok-Yong (Duke)

    2012-07-11

    Nucleosides are required for DNA and RNA synthesis, and the nucleoside adenosine has a function in a variety of signalling processes. Transport of nucleosides across cell membranes provides the major source of nucleosides in many cell types and is also responsible for the termination of adenosine signalling. As a result of their hydrophilic nature, nucleosides require a specialized class of integral membrane proteins, known as nucleoside transporters (NTs), for specific transport across cell membranes. In addition to nucleosides, NTs are important determinants for the transport of nucleoside-derived drugs across cell membranes. A wide range of nucleoside-derived drugs, including anticancer drugs (such as Ara-C and gemcitabine) and antiviral drugs (such as zidovudine and ribavirin), have been shown to depend, at least in part, on NTs for transport across cell membranes. Concentrative nucleoside transporters, members of the solute carrier transporter superfamily SLC28, use an ion gradient in the active transport of both nucleosides and nucleoside-derived drugs against their chemical gradients. The structural basis for selective ion-coupled nucleoside transport by concentrative nucleoside transporters is unknown. Here we present the crystal structure of a concentrative nucleoside transporter from Vibrio cholerae in complex with uridine at 2.4 {angstrom}. Our functional data show that, like its human orthologues, the transporter uses a sodium-ion gradient for nucleoside transport. The structure reveals the overall architecture of this class of transporter, unravels the molecular determinants for nucleoside and sodium binding, and provides a framework for understanding the mechanism of nucleoside and nucleoside drug transport across cell membranes.

  17. Estrogen inhibits cell cycle progression and retinoblastoma phosphorylation in rhesus ovarian surface epithelial cell culture

    SciTech Connect (OSTI)

    Wright, Jay W.; Stouffer, Richard L.; Rodland, Karin D.

    2003-10-31

    Estrogen promotes the growth of some ovarian cancer cells at nanomolar concentrations, but has been shown to inhibit growth of normal ovarian surface epithelial (OSE) cells at micromolar concentrations (1?g/ml). OSE cells express the estrogen receptor (ER)-?, and are the source of 90% of various cancers. The potential sensitivity of OSE cells to estrogen stresses the importance of understanding the estrogen-dependent mechanisms at play in OSE proliferation and transformation, as well as in anticancer treatment. We investigated the effects of estradiol on cell proliferation in vitro, and demonstrate an intracellular locus of action of estradiol in cultured rhesus ovarian surface epithelial (RhOSE) cells. We show that ovarian and breast cells are growth-inhibited by micromolar concentration of estradiol and that this inhibition correlates with estrogen receptor expression. We further show that normal rhesus OSE cells do not activate ERK or Akt in response to estradiol nor does estradiol block the ability of serum to stimulate ERK or induce cyclin D expression. Contrarily, estradiol inhibits serum-dependent retinoblastoma protein (Rb) phosphorylation and blocks DNA synthesis. This inhibition does not formally arrest cells and is reversible within hours of estrogen withdrawal. Our data are consistent with growth inhibition by activation of Rb and indicate that sensitivity to hormone therapy in anticancer treatment can be modulated by cell cycle regulators downstream of the estrogen receptor.

  18. CELL TYPES, DIFFERENTIAL CELL COUNTS, AND BLOOD CELL MEASUREMENTS OF

    E-Print Network [OSTI]

    examined under oil immersion at 800 and 1200 power. Cells were measured at 800 power. Cell classificationCELL TYPES, DIFFERENTIAL CELL COUNTS, AND BLOOD CELL MEASUREMENTS OF A PORTUGUESE SHARK describe the cell types, differential cell counts, and measurements of both the erythrocytes and leukocytes

  19. Osmotic Stabilisation of Concentrated Emulsions and Foams

    E-Print Network [OSTI]

    A. J. Webster; M. E. Cates

    2001-01-19

    In the absence of coalescence, coarsening of emulsions (and foams) is controlled by molecular diffusion of dispersed phase between droplets/bubbles. Studies of dilute emulsions have shown how the osmotic pressure of a trapped species within droplets can ``osmotically stabilise'' the emulsion. Webster and Cates (Langmuir, 1998, 14, 2068-2079) gave rigorous criteria for osmotic stabilisation of mono- and polydisperse emulsions, in the dilute regime. We consider here whether analogous criteria exist for the osmotic stabilisation of mono- and polydisperse concentrated emulsions and foams, and suggest that the pressure differences driving coarsening are small compared to the mean Laplace pressure. An exact calculation confirms this for a monodisperse 2D model, finding a bubble's pressure as P_i = P + Pi + P_i^G, with P, Pi the atmospheric and osmotic pressures, and P_i^G a ``geometric pressure'' that reduces to the Laplace pressure only for a spherical bubble. For Princen's 2D emulsion model, P_i^G is only 5% larger in the dry limit than the dilute limit. We conclude that osmotic stabilisation of dense systems typically requires a pressure of trapped molecules in each droplet that is comparable to the Laplace pressures the same droplets would have if spherical, as opposed to the much larger Laplace pressures present in the system. We study coarsening of foams and concentrated emulsions when there is insufficient of the trapped species present. Rate-limiting mechanisms are considered, their applicability and associated droplet growth rates discussed. In a concentrated foam or emulsion, a finite yield threshold for droplet rearrangement may be enough to prevent coarsening of the remainder.

  20. Mapping Suitability Areas for Concentrated Solar Power Plants Using Remote Sensing Data

    SciTech Connect (OSTI)

    Omitaomu, Olufemi A; Singh, Nagendra; Bhaduri, Budhendra L

    2015-01-01

    The political push to increase power generation from renewable sources such as solar energy requires knowing the best places to site new solar power plants with respect to the applicable regulatory, operational, engineering, environmental, and socioeconomic criteria. Therefore, in this paper, we present applications of remote sensing data for mapping suitability areas for concentrated solar power plants. Our approach uses digital elevation model derived from NASA s Shuttle Radar Topographic Mission (SRTM) at a resolution of 3 arc second (approx. 90m resolution) for estimating global solar radiation for the study area. Then, we develop a computational model built on a Geographic Information System (GIS) platform that divides the study area into a grid of cells and estimates site suitability value for each cell by computing a list of metrics based on applicable siting requirements using GIS data. The computed metrics include population density, solar energy potential, federal lands, and hazardous facilities. Overall, some 30 GIS data are used to compute eight metrics. The site suitability value for each cell is computed as an algebraic sum of all metrics for the cell with the assumption that all metrics have equal weight. Finally, we color each cell according to its suitability value. We present results for concentrated solar power that drives a stream turbine and parabolic mirror connected to a Stirling Engine.

  1. Method for measuring lead concentrations in blood

    DOE Patents [OSTI]

    Nogar, Nicholas S. (Los Alamos, NM)

    2001-01-01

    Method for measuring lead concentrations in blood. The present invention includes the use of resonant laser ablation to analyze .ltoreq.1 .mu.L (or equivalent mass) samples of blood for lead content. A typical finger prick, for example, yields about 10 .mu.L. Solid samples may also readily be analyzed by resonant laser ablation. The sample is placed on a lead-free, electrically conducting substrate and irradiated with a single, focused laser beam which simultaneously vaporizes, atomizes, and resonantly ionizes an analyte of interest in a sample. The ions are then sorted, collected and detected using a mass spectrometer.

  2. Suspension Hydrogen Reduction of Iron Oxide Concentrates

    SciTech Connect (OSTI)

    H.Y. Sohn

    2008-03-31

    The objective of the project is to develop a new ironmaking technology based on hydrogen and fine iron oxide concentrates in a suspension reduction process. The ultimate objective of the new technology is to replace the blast furnace and to drastically reduce CO2 emissions in the steel industry. The goals of this phase of development are; the performance of detailed material and energy balances, thermochemical and equilibrium calculations for sulfur and phosphorus impurities, the determination of the complete kinetics of hydrogen reduction and bench-scale testing of the suspension reduction process using a large laboratory flash reactor.

  3. Acoustic concentration of particles in fluid flow

    DOE Patents [OSTI]

    Ward, Michael D. (Los Alamos, NM); Kaduchak, Gregory (Los Alamos, NM)

    2010-11-23

    An apparatus for acoustic concentration of particles in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.

  4. NREL: Learning - Concentrating Solar Power Basics

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration wouldMass map shines lightGeospatial Toolkit The Geospatial Toolkit isPublicationsConcentrating

  5. Sandia Energy - Concentrating Solar Power (CSP)

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II) byMultidayAlumniProjects Caterpillar,Concentrating Solar Power (CSP)

  6. NO concentration imaging in turbulent nonpremixed flames

    SciTech Connect (OSTI)

    Schefer, R.W. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The importance of NO as a pollutant species is well known. An understanding of the formation characteristics of NO in turbulent hydrocarbon flames is important to both the desired reduction of pollutant emissions and the validation of proposed models for turbulent reacting flows. Of particular interest is the relationship between NO formation and the local flame zone, in which the fuel is oxidized and primary heat release occurs. Planar imaging of NO provides the multipoint statistics needed to relate NO formation to the both the flame zone and the local turbulence characteristics. Planar imaging of NO has been demonstrated in turbulent flames where NO was seeded into the flow at high concentrations (2000 ppm) to determine the gas temperature distribution. The NO concentrations in these experiments were significantly higher than those expected in typical hydrocarbon-air flames, which require a much lower detectability limit for NO measurements. An imaging technique based on laser-induced fluorescence with sufficient sensitivity to study the NO formation mechanism in the stabilization region of turbulent lifted-jet methane flames.

  7. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    SciTech Connect (OSTI)

    NA

    2004-11-22

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this modeling activity is to predict dissolved concentrations or solubility limits for 14 elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) important to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are in the form of tabulated functions with pH and log (line integral) CO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. The output data from this report are fundamental inputs for Total System Performance Assessment for the License Application (TSPA-LA) to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for all of the actinides. These models cover broad ranges of environmental conditions so that they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise addressed.

  8. Strain concentrations in pipelines with concrete coating

    SciTech Connect (OSTI)

    Ness, O.B.; Verley, R. [Statoil, Trondheim (Norway)

    1996-08-01

    This paper concerns the strain distribution, and in particular strain concentration in field joints, for concrete-covered pipelines during laying. A semi-analytical model, full-scale tests to verify the model, and results of a parameter study are described. The model is used to establish nonlinear moment-curvature curves at a number of cross sections on the concrete-coated pipe and in the field joint (FJ). These are used to establish a strain concentration factor (SCF) for the FJ, or characteristics for a varying stiffness model of a pipe for direct use in lay analyses. Constant moment, four-point bending tests have been conducted on 16-in and 20-in dia, concrete-coated pipes as well as material tests on the pipe steel, corrosion coating and concrete. The behavior of the pipe, and in particular the SCF at the field joints, is investigated and compared to predictions using the semi-analytical model. The model is found to give a good prediction of the SCF and strain distribution along the pipe joint, for both the steel and the concrete, and is suitable for use in lay analyses for the overbend of S-mode lay vessels.

  9. Optical monitor for water vapor concentration

    DOE Patents [OSTI]

    Kebabian, Paul (Acton, MA)

    1998-01-01

    A system for measuring and monitoring water vapor concentration in a sample uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to a water vapor absorption line. In a preferred embodiment, the argon line is split by a magnetic field parallel to the direction of light propagation from the lamp into sets of components of downshifted and upshifted frequencies of approximately 1575 Gauss. The downshifted components are centered on a water vapor absorption line and are thus readily absorbed by water vapor in the sample; the upshifted components are moved away from that absorption line and are minimally absorbed. A polarization modulator alternately selects the upshifted components or downshifted components and passes the selected components to the sample. After transmission through the sample, the transmitted intensity of a component of the argon line varies as a result of absorption by the water vapor. The system then determines the concentration of water vapor in the sample based on differences in the transmitted intensity between the two sets of components. In alternative embodiments alternate selection of sets of components is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to the emitting plasma.

  10. Optical monitor for water vapor concentration

    DOE Patents [OSTI]

    Kebabian, P.

    1998-06-02

    A system for measuring and monitoring water vapor concentration in a sample uses as a light source an argon discharge lamp, which inherently emits light with a spectral line that is close to a water vapor absorption line. In a preferred embodiment, the argon line is split by a magnetic field parallel to the direction of light propagation from the lamp into sets of components of downshifted and upshifted frequencies of approximately 1575 Gauss. The downshifted components are centered on a water vapor absorption line and are thus readily absorbed by water vapor in the sample; the upshifted components are moved away from that absorption line and are minimally absorbed. A polarization modulator alternately selects the upshifted components or downshifted components and passes the selected components to the sample. After transmission through the sample, the transmitted intensity of a component of the argon line varies as a result of absorption by the water vapor. The system then determines the concentration of water vapor in the sample based on differences in the transmitted intensity between the two sets of components. In alternative embodiments alternate selection of sets of components is achieved by selectively reversing the polarity of the magnetic field or by selectively supplying the magnetic field to the emitting plasma. 5 figs.

  11. Accelerated Stress Testing of Hydrocarbon-Based Encapsulants for Medium-Concentration CPV Applications

    SciTech Connect (OSTI)

    Kempe, M. D.; Moricone, T. J.; Kilkenny, M.; Zhang, J. Z.

    2011-02-01

    Concentrating photovoltaic (CPV) systems have great potential to reduce photovoltaic (PV) electricity costs because of the relatively low cost of optical components as compared to PV cells. A transparent polymeric material is used to optically couple the PV cell to optical components and is thus exposed to the concentrated light source at elevated temperatures. In this work polymeric encapsulant materials are positioned close to a Xenon arc lamp to expose them to ultraviolet radiation (UV) that is about 42 times as intense as sunlight. Furthermore, different glass types are used as filters to modify the spectral distribution of light in the UV range. A strong sensitivity of non-silicone-based encapsulants to light below ~350 nm is demonstrated. Of all the materials examined in this study, the polydimethyl silicone samples performed the best. The next best material was an ionomer which maintained optical transmission but became photo-oxidized where exposed to the atmosphere.

  12. Effective charges and virial pressure of concentrated macroion solutions

    E-Print Network [OSTI]

    Niels Boon; Guillermo Ivan Guerrero-Garcia; Rene van Roij; Monica Olvera de la Cruz

    2015-07-15

    The stability of colloidal suspensions is crucial in a wide variety of processes including the fabrication of photonic materials and scaffolds for biological assemblies. The ionic strength of the electrolyte that suspends charged colloids is widely used to control the physical properties of colloidal suspensions. The extensively used two-body Derjaguin-Landau-Verwey-Overbeek (DLVO) approach allows for a quantitative analysis of the effective electrostatic forces between colloidal particles. DLVO relates the ionic double-layers, which enclose the particles, to their effective electrostatic repulsion. Nevertheless, the double layer is distorted at high macroion volume fractions. Therefore, DLVO cannot describe the many-body effects that arise in concentrated suspensions. We show that this problem can be largely resolved by identifying effective point charges for the macroions using cell theory. This extrapolated point charge (EPC) method assigns effective point charges in a consistent way, taking into account the excluded volume of highly charged macroions at any concentration, and thereby naturally accounting for high volume fractions in both salt-free and added-salt conditions. We provide an analytical expression for the effective pair potential and validate the EPC method by comparing molecular dynamics simulations of macroions and monovalent microions that interact via Coulombic potentials to simulations of macroions interacting via the derived EPC effective potential. The simulations reproduce the macroion-macroion spatial correlation and the virial pressure obtained with the EPC model. Our findings provide a route to relate the physical properties such as pressure in systems of screened-Coulomb particles to experimental measurements.

  13. MAP: Concentrating Solar Power Across the United States

    Broader source: Energy.gov [DOE]

    Explore our latest map, charting the location of concentrating solar power plants across the country.

  14. Durability of Poly(Methyl Methacrylate) Lenses Used in Concentrating Photovoltaic Technology (Revised) (Presentation)

    SciTech Connect (OSTI)

    Miller, D. C.; Carloni, J. D.; Pankow, J. W.; Gjersing, E. L.; To, B.; Packard, C. E.; Kennedy, C. E.; Kurtz, S. R.

    2012-01-01

    Concentrating photovoltaic (CPV) technology recently gained interest based on its expected low levelized cost of electricity, high efficiency, and scalability. Many CPV systems employ Fresnel lenses composed of poly(methyl methacrylate) (PMMA) to obtain a high optical flux density on the cell. The optical and mechanical durability of these lenses, however, is not well established relative to the desired surface life of 30 years. Our research aims to quantify the expected lifetime of PMMA in key market locations (FL, AZ, and CO).

  15. Generator configuration for solid oxide fuel cells

    DOE Patents [OSTI]

    Reichner, Philip (Plum Boro, PA)

    1989-01-01

    Disclosed are improvements in a solid oxide fuel cell generator 1 having a multiplicity of electrically connected solid oxide fuel cells 2, where a fuel gas is passed over one side of said cells and an oxygen-containing gas is passed over the other side of said cells resulting in the generation of heat and electricity. The improvements comprise arranging the cells in the configuration of a circle, a spiral, or folded rows within a cylindrical generator, and modifying the flow rate, oxygen concentration, and/or temperature of the oxygen-containing gases that flow to those cells that are at the periphery of the generator relative to those cells that are at the center of the generator. In these ways, a more uniform temperature is obtained throughout the generator.

  16. Simultaneous and rapid determination of multiple component concentrations in a Kraft liquor process stream

    DOE Patents [OSTI]

    Li, Jian (Marietta, GA); Chai, Xin Sheng (Atlanta, GA); Zhu, Junyoung (Marietta, GA)

    2008-06-24

    The present invention is a rapid method of determining the concentration of the major components in a chemical stream. The present invention is also a simple, low cost, device of determining the in-situ concentration of the major components in a chemical stream. In particular, the present invention provides a useful method for simultaneously determining the concentrations of sodium hydroxide, sodium sulfide and sodium carbonate in aqueous kraft pulping liquors through use of an attenuated total reflectance (ATR) tunnel flow cell or optical probe capable of producing a ultraviolet absorbency spectrum over a wavelength of 190 to 300 nm. In addition, the present invention eliminates the need for manual sampling and dilution previously required to generate analyzable samples. The inventive method can be used in Kraft pulping operations to control white liquor causticizing efficiency, sulfate reduction efficiency in green liquor, oxidation efficiency for oxidized white liquor and the active and effective alkali charge to kraft pulping operations.

  17. Energy concentration in composite quantum systems

    SciTech Connect (OSTI)

    Kurcz, Andreas; Beige, Almut; Capolupo, Antonio; Vitiello, Giuseppe; Del Giudice, Emilio

    2010-06-15

    The spontaneous emission of photons from optical cavities and from trapped atoms has been studied extensively in the framework of quantum optics. Theoretical predictions based on the rotating wave approximation (RWA) are, in general, in very good agreement with experimental findings. However, current experiments aim at combining better and better cavities with large numbers of tightly confined atoms. Here we predict an energy concentrating mechanism in the behavior of such a composite quantum system which cannot be described by the RWA. Its result is the continuous leakage of photons through the cavity mirrors, even in the absence of external driving. We conclude with a discussion of the predicted phenomenon in the context of thermodynamics.

  18. Exploratory study of complexant concentrate waste processing

    SciTech Connect (OSTI)

    Lumetta, G.J.; Bray, L.A.; Kurath, D.E.; Morrey, J.R.; Swanson, J.L.; Wester, D.W.

    1993-02-01

    The purpose of this exploratory study, conducted by Pacific Northwest Laboratory for Westinghouse Hanford Company, was to determine the effect of applying advanced chemical separations technologies to the processing and disposal of high-level wastes (HLW) stored in underground tanks. The major goals of this study were to determine (1) if the wastes can be partitioned into a small volume of HLW plus a large volume of low-level waste (LLW), and (2) if the activity in the LLW can be lowered enough to meet NRC Class LLW criteria. This report presents the results obtained in a brief scouting study of various processes for separating radionuclides from Hanford complexant concentrate (CC) waste.

  19. Toxicity Data to Determine Refrigerant Concentration Limits

    SciTech Connect (OSTI)

    Calm, James M.

    2000-09-30

    This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others in commercial or developmental status. Appendices provide profiles for the cited single-compound refrigerants and for R-500 and R-502 as well as narrative toxicity summaries for common refrigerants. The report includes an extensive set of references.

  20. Broadband enhancement of light harvesting in luminescent solar concentrator

    E-Print Network [OSTI]

    Xiao, Yun-Feng; Xiao, Lixin; Sun, Fang-Wen; Gong, Qihuang

    2010-01-01

    Luminescent solar concentrator (LSC) can absorb large-area incident sunlight, then emit luminescence with high quantum efficiency, which finally be collected by a small photovoltaic (PV) system. The light-harvesting area of the PV system is much smaller than that of the LSC system, potentially improving the efficiency and reducing the cost of solar cells. Here, based on Fermi-golden rule, we present a theoretical description of the luminescent process in nanoscale LSCs where the conventional ray-optics model is no longer applicable. As an example calculated with this new model, we demonstrate that a slot waveguide consisting of a nanometer-sized low-index slot region sandwiched by two high-index regions provides a broadband enhancement of light harvesting by the luminescent centers in the slot region. This is because the slot waveguide can (1) greatly enhance the spontaneous emission due to the Purcell effect, (2) dramatically increase the effective absorption cross-section of luminescent centers, and (3) str...

  1. Inference of Blood Glucose Concentrations from Subcutaneous Glucose Concentrations: Applications to Glucose Biosensors

    E-Print Network [OSTI]

    to Glucose Biosensors ANGELA C. FREELAND and ROGER T. BONNECAZE Department of Chemical Engineering concentrations are successfully applied to experimental measurements using glucose biosensors reported0090-6964 99 01304-1 Keywords--Biosensors, Mathematical model, Algorithms, In- verse problems, Input

  2. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    are like multi-junction solar cells [GH05]. Fourth, dyes canof the solar spectrum like multi-junction cells to improve

  3. Large effect of polydispersity on defect concentrations in colloidal crystals

    E-Print Network [OSTI]

    Sander Pronk; Daan Frenkel

    2004-02-03

    We compute the equilibrium concentration of stacking faults and point defects in polydisperse hard-sphere crystals. We find that, while the concentration of stacking faults remains similar to that of monodisperse hard sphere crystals, the concentration of vacancies decreases by about a factor two. Most strikingly, the concentration of interstitials in the maximally polydisperse crystal may be some six orders of magnitude larger than in a monodisperse crystal. We show that this dramatic increase in interstitial concentration is due to the increased probability of finding small particles and that the small-particle tail of the particle size distribution is crucial for the interstitial concentration in a colloidal crystal.

  4. Electrochemical cell

    DOE Patents [OSTI]

    Redey, L.I.; Vissers, D.R.; Prakash, J.

    1996-07-16

    An electrochemical cell is described having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm{sup 3}; the cell can be 90% recharged in three hours and can operate at temperatures below 160 C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6{times}10{sup 4}cm{sup 2}/g of Ni. 6 figs.

  5. Electrochemical cell

    DOE Patents [OSTI]

    Redey, L.I.; Vissers, D.R.; Prakash, J.

    1994-02-01

    An electrochemical cell is described having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm[sup 3]; the cell can be 90% recharged in three hours and can operate at temperatures below 160 C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6[times]10[sup 4] cm[sup 2]/g of Ni. 8 figures.

  6. Electrochemical cell

    DOE Patents [OSTI]

    Redey, Laszlo I. (Downers Grove, IL); Vissers, Donald R. (Naperville, IL); Prakash, Jai (Downers Grove, IL)

    1994-01-01

    An electrochemical cell having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm.sup.3 ; the cell can be 90% recharged in three hours and can operate at temperatures below 160.degree. C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6.times.10.sup.4 cm.sup.2 /g of Ni.

  7. Electrochemical cell

    DOE Patents [OSTI]

    Redey, Laszlo I. (6851 Carpenter St., Downers Grove, IL 60516); Vissers, Donald R. (611 Clover Ct., Naperville, IL 60540); Prakash, Jai (2205 Arbor Cir. 8, Downers Grove, IL 60515)

    1996-01-01

    An electrochemical cell having a bimodal positive electrode, a negative electrode of an alkali metal, and a compatible electrolyte including an alkali metal salt molten at the cell operating temperature. The positive electrode has an electrochemically active layer of at least one transition metal chloride at least partially present as a charging product, and additives of bromide and/or iodide and sulfur in the positive electrode or the electrolyte. Electrode volumetric capacity is in excess of 400 Ah/cm.sup.3 ; the cell can be 90% recharged in three hours and can operate at temperatures below 160.degree. C. There is also disclosed a method of reducing the operating temperature and improving the overall volumetric capacity of an electrochemical cell and for producing a positive electrode having a BET area greater than 6.times.10.sup.4 cm.sup.2 /g of Ni.

  8. Load cell

    DOE Patents [OSTI]

    Spletzer, B.L.

    1998-12-15

    A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components. 16 figs.

  9. Concentration of measures via size biased couplings

    E-Print Network [OSTI]

    Ghosh, Subhankar

    2009-01-01

    Let $Y$ be a nonnegative random variable with mean $\\mu$ and finite positive variance $\\sigma^2$, and let $Y^s$, defined on the same space as $Y$, have the $Y$ size biased distribution, that is, the distribution characterized by E[Yf(Y)]=\\mu E f(Y^s) for all functions $f$ for which these expectations exist. Under a variety of conditions on the coupling of Y and $Y^s$, including combinations of boundedness and monotonicity, concentration of measure inequalities hold. Examples include the number of relatively ordered subsequences of a random permutation, sliding window statistics including the number of m-runs in a sequence of coin tosses, the number of local maximum of a random function on a lattice, the number of urns containing exactly one ball in an urn allocation model, the volume covered by the union of $n$ balls placed uniformly over a volume n subset of d diml Euclidean space, the number of bulbs switched on at the terminal time in the so called lightbulb process, the number of isolated vertices in the ...

  10. Renormalized energy concentration in random matrices

    E-Print Network [OSTI]

    Alexei Borodin; Sylvia Serfaty

    2012-10-23

    We define a "renormalized energy" as an explicit functional on arbitrary point configurations of constant average density in the plane and on the real line. The definition is inspired by ideas of [SS1,SS3]. Roughly speaking, it is obtained by subtracting two leading terms from the Coulomb potential on a growing number of charges. The functional is expected to be a good measure of disorder of a configuration of points. We give certain formulas for its expectation for general stationary random point processes. For the random matrix $\\beta$-sine processes on the real line (beta=1,2,4), and Ginibre point process and zeros of Gaussian analytic functions process in the plane, we compute the expectation explicitly. Moreover, we prove that for these processes the variance of the renormalized energy vanishes, which shows concentration near the expected value. We also prove that the beta=2 sine process minimizes the renormalized energy in the class of determinantal point processes with translation invariant correlation kernels.

  11. Analytical instrument with apparatus for sample concentrating

    DOE Patents [OSTI]

    Zaromb, Solomon (Hinsdale, IL)

    1989-01-01

    A system for analysis of trace concentrations of contaminants in air includes a portable liquid chromatograph and a preconcentrator for the contaminants to be analyzed. The preconcentrator includes a sample bag having an inlet valve and an outlet valve for collecting an air sample. When the sample is collected the sample bag is connected in series with a sorbing apparatus in a recirculation loop. The sorbing apparatus has an inner gas-permeable container containing a sorbent material and an outer gas-impermeable container. The sample is circulated through the outer container and around the inner container for trapping and preconcentrating the contaminants in the sorbent material. The sorbent material may be a liquid having the same composition as the mobile phase of the chromatograph for direct injection thereinto. Alternatively, the sorbent material may be a porous, solid body, to which mobile phase liquid is added after preconcentration of the contaminants for dissolving the contaminants, the liquid solution then being withdrawn for injection into the chromatograph.

  12. Capacity Value of Concentrating Solar Power Plants

    SciTech Connect (OSTI)

    Madaeni, S. H.; Sioshansi, R.; Denholm, P.

    2011-06-01

    This study estimates the capacity value of a concentrating solar power (CSP) plant at a variety of locations within the western United States. This is done by optimizing the operation of the CSP plant and by using the effective load carrying capability (ELCC) metric, which is a standard reliability-based capacity value estimation technique. Although the ELCC metric is the most accurate estimation technique, we show that a simpler capacity-factor-based approximation method can closely estimate the ELCC value. Without storage, the capacity value of CSP plants varies widely depending on the year and solar multiple. The average capacity value of plants evaluated ranged from 45%?90% with a solar multiple range of 1.0-1.5. When introducing thermal energy storage (TES), the capacity value of the CSP plant is more difficult to estimate since one must account for energy in storage. We apply a capacity-factor-based technique under two different market settings: an energy-only market and an energy and capacity market. Our results show that adding TES to a CSP plant can increase its capacity value significantly at all of the locations. Adding a single hour of TES significantly increases the capacity value above the no-TES case, and with four hours of storage or more, the average capacity value at all locations exceeds 90%.

  13. High concentration of deuterium in palladium

    SciTech Connect (OSTI)

    Uhm, H.S.; Lee, W.M. )

    1992-01-01

    In this paper, based on theoretical calculations, new schemes to increase the deuterium density in palladium over its initial value are presented. A high deuterium concentration in palladium is needed for application to solid-state fusion. The first deuterium enrichment scheme makes use of plasma ion implantation, which consists of a cylindrical palladium rod (target) preloaded with deuterium atoms, coated with diffusion barrier material, and immersed in a deuterium plasma. The palladium rod is connected to a high-power modulator, which provides a series of negative voltage pulses. During these negative pulses, deuterium ions fall on the target, penetrate the diffusion barrier, and are implanted inside the palladium. For reasonable system parameters allowed by current technology, theoretical calculations indicate that the saturation deuterium density after prolonged ion implantation can be several times the palladium atomic number density. The second deuterium enrichment scheme makes use of temperature gradient effects on the deuterium solubility in palladium. A heat source at temperature T{sub 2} and a heat sink at temperature T{sub 1} (where T{sub 2} {gt} T{sub 1}) are in contact with two different parts of a palladium sample, which has been presoaked with deuterium atoms and has been coated with diffusion barrier material or has been securely locked in a metal case. The temperature gradient created in the sample from such an arrangement forces the deuterium atoms in the hot region to migrate into the cold region, resulting in higher deuterium density in the cold region.

  14. Method for processing silicon solar cells

    DOE Patents [OSTI]

    Tsuo, Y. Simon (Golden, CO); Landry, Marc D. (Lafayette, CO); Pitts, John R. (Lakewood, CO)

    1997-01-01

    The instant invention teaches a novel method for fabricating silicon solar cells utilizing concentrated solar radiation. The solar radiation is concentrated by use of a solar furnace which is used to form a front surface junction and back-surface field in one processing step. The present invention also provides a method of making multicrystallline silicon from amorphous silicon. The invention also teaches a method of texturing the surface of a wafer by forming a porous silicon layer on the surface of a silicon substrate and a method of gettering impurities. Also contemplated by the invention are methods of surface passivation, forming novel solar cell structures, and hydrogen passivation.

  15. Method for processing silicon solar cells

    DOE Patents [OSTI]

    Tsuo, Y.S.; Landry, M.D.; Pitts, J.R.

    1997-05-06

    The instant invention teaches a novel method for fabricating silicon solar cells utilizing concentrated solar radiation. The solar radiation is concentrated by use of a solar furnace which is used to form a front surface junction and back-surface field in one processing step. The present invention also provides a method of making multicrystalline silicon from amorphous silicon. The invention also teaches a method of texturing the surface of a wafer by forming a porous silicon layer on the surface of a silicon substrate and a method of gettering impurities. Also contemplated by the invention are methods of surface passivation, forming novel solar cell structures, and hydrogen passivation. 2 figs.

  16. Equipment Loan for Concentrated PV Cavity Converter (PVCC) Research: Cooperative Research and Development Final Report, CRADA Number CRD-08-285

    SciTech Connect (OSTI)

    Netter, Judy

    2015-07-28

    Interest in High Concentration Photovoltaics (HCPV) for terrestrial applications has significantly grown in recent years. A major driver behind this growth trend is the availability of high efficiency multi-junction (MJ) cells that promise reliable operation under high concentrations (500 to 1000 suns). The primary impact of HCPV on the solar electricity cost is the dramatic reduction in cell cost. For terrestrial HCPV systems, operating at concentrations ? 500 suns, the expensive MJ cells are marginally affordable. Most recently, triple-junction test cells have achieved a conversion efficiency of over 40% under concentrated sunlight. Photovoltaic Cavity Converter (PVCC) is a multi-bandgap, high concentration PV device developed by United Innovations, Inc., under subcontract to NREL. The lateral- (2- dimensional) structure of PVCC, as opposed to vertical multi-junction (MJ) structure, helps to circumvent most of the developmental challenges MJ technology has yet to overcome. This CRADA will allow the continued development of this technology by United Innovations. This project was funded by the California Energy Commission and is the second phase of a twopart demonstration program. The key advantage of the design was the use of a PVCC as the receiver. PVCCs efficiently process highly concentrated solar radiation into electricity by recycling photons that are reflected from the surface of the cells. Conventional flat, twodimensional receivers cannot recycle photons and the reflected photons are lost to the conversion process.

  17. Electrical Modulation of Ion Concentration in Dual-Gated Nanochannels Yang Liu, Qiushi Ran, and Robert W. Dutton

    E-Print Network [OSTI]

    Liu, Yang

    Electrical Modulation of Ion Concentration in Dual-Gated Nanochannels Yang Liu, Qiushi Ran simulations demonstrate the operating principles of using electrical biases in dual-gated nano potential applications range from fuel cells [11] to desalination [12]. Nevertheless, in contrast

  18. Near-infrared approaches for cell culture monitoring 

    E-Print Network [OSTI]

    Lee, Seung Joon

    2003-01-01

    Current techniques for monitoring glucose and lactate concentrations in cell culture media require invasive and tedious handling of the sample for sterile media removal and nutrient replacement. Even though in situ or ex situ analyte monitoring...

  19. Micro Fuel Cells Direct Methanol Fuel Cells

    E-Print Network [OSTI]

    Micro Fuel Cells TM Direct Methanol Fuel Cells for Portable Power A Fuel Cell System Developer-17, 2002 Phoenix, Arizona #12;Micro Fuel Cells Direct Methanol Fuel Cells for Portable Power Outline (1 Energy Content (Wh) Volume(cm^3) Li-Ion Battery DMFC #12;Direct Methanol Fuel Cell Technology

  20. Cell Stem Cell The Systematic Production

    E-Print Network [OSTI]

    Zandstra, Peter W.

    Cell Stem Cell Review The Systematic Production of Cells for Cell Therapies Daniel C. Kirouac1 to guide the development of next-generation technologies capable of producing cell-based products in a safe will enhance cell therapy product quality and safety, expediting clinical development. Breakthroughs

  1. Concentrating Solar Power Program Review 2013 (Book) (Revised)

    SciTech Connect (OSTI)

    Not Available

    2013-06-01

    This U.S. Department of Energy (DOE) Concentrating Solar Power Program Review Meeting booklet will be provided to attendees at the Concentrating Solar Power Review Meeting in Phoenix, Arizona on April 23-25, 2013.

  2. RADON AND ALDEHYDE CONCENTRATIONS IN THE INDOOR ENVIRONMENT

    E-Print Network [OSTI]

    Moschandreas, D.J.

    2010-01-01

    ENVIRONMENT DIVISION RADON AND ALDEHYDE CONCENTRATIONS INLBL-12590 EEB-Vent 81-12 RADON AND ALDEHYDE CONCENTRATIONS2.1 Monitoring History of Radon Table 2.1. Integrated (PERM)

  3. evaluation-concentrated-piperazine | netl.doe.gov

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

    Concentrated Piperazine for CO2 Capture from Coal-Fired Flue Gas Project No.: DE-FE0005654 URS Group, Inc. will investigate the use of concentrated piperazine (PZ) as a solvent for...

  4. Lithium Diisopropylamide: Oligomer Structures at Low Ligand Concentrations

    E-Print Network [OSTI]

    Collum, David B.

    Lithium Diisopropylamide: Oligomer Structures at Low Ligand Concentrations Jennifer L. Rutherford-dimensional 6Li and 15N NMR spectroscopic studies of lithium diisopropylamide (LDA) solvated ligand concentrations are discussed. Introduction Spectroscopic studies of lithium amides at low ligand

  5. Modelling acceptance of sunlight in high and low photovoltaic concentration

    SciTech Connect (OSTI)

    Leutz, Ralf

    2014-09-26

    A simple model incorporating linear radiation characteristics, along with the optical trains and geometrical concentration ratios of solar concentrators is presented with performance examples for optical trains of HCPV, LCPV and benchmark flat-plate PV.

  6. Process of concentrating ethanol from dilute aqueous solutions thereof

    DOE Patents [OSTI]

    Oulman, Charles S. [Ames, IA; Chriswell, Colin D. [Slater, IA

    1981-07-07

    Relatively dilute aqueous solutions of ethanol are concentrated by passage through a bed of a crystalline silica polymorph, such as silicalite, to adsorb the ethanol with residual dilute feed in contact with the bed, which is displaced by passing concentrated aqueous ethanol through the bed without displacing the adsorbed ethanol. A product concentrate is then obtained by removing the adsorbed ethanol from the bed together with at least a portion of the concentrated aqueous ethanol used as the displacer liquid. This process permits ethanol to be concentrated from dilute fermentation beers, which may contain from 6 to 10% ethanol, to obtain a concentrate product at very low energy cost having an ethanol concentration in excess of 95%, such as a concentration of from 98 to 99.5%.

  7. Optimizing mixer geometries for dielectrophoretic micro-concentrators

    E-Print Network [OSTI]

    Lee, Hsu-Yi

    2006-01-01

    Dielectrophoretic (DEP) force, generated by interdigitated electrodes (IDEs), has been utilized to capture bio-particles for microfluidic concentration. However, due to the localized DEP force, DEP-based ,/ -concentrators ...

  8. Heat Pipe Performance Enhancement with Binary Mixture Fluids that Exhibit Strong Concentration Marangoni Effects

    E-Print Network [OSTI]

    Armijo, Kenneth Miguel

    2011-01-01

    materials costs for multijunction cells over monocrystallineapplications of multijunction cells. Tandem cells consistinglimiting subcell. For multijunction cells, Wanlass et al. [

  9. Teroxirone inhibited growth of human non-small cell lung cancer cells by activating p53

    SciTech Connect (OSTI)

    Wang, Jing-Ping; Lin, Kai-Han; Liu, Chun-Yen; Yu, Ya-Chu; Wu, Pei-Tsun [Department of Life Science, National Taiwan Normal University, Taipei, Taiwan (China); Chiu, Chien-Chih [Department of Biotechnology, Kaohsiung Medical University, Kaohsiung, Taiwan (China); Su, Chun-Li [Department of Human Development and Family Studies, National Taiwan Normal University, Taipei, Taiwan (China); Chen, Kwun-Min [Department of Chemistry, National Taiwan Normal University, Taipei, Taiwan (China); Fang, Kang, E-mail: kangfang@ntnu.edu.tw [Department of Life Science, National Taiwan Normal University, Taipei, Taiwan (China)

    2013-11-15

    In this work, we demonstrated that the growth of human non-small-cell-lung-cancer cells H460 and A549 cells can be inhibited by low concentrations of an epoxide derivative, teroxirone, in both in vitro and in vivo models. The cytotoxicity was mediated by apoptotic cell death through DNA damage. The onset of ultimate apoptosis is dependent on the status of p53. Teroxirone caused transient elevation of p53 that activates downstream p21 and procaspase-3 cleavage. The presence of caspase-3 inhibitor reverted apoptotic phenotype. Furthermore, we showed the cytotoxicity of teroxirone in H1299 cells with stable ectopic expression of p53, but not those of mutant p53. A siRNA-mediated knockdown of p53 expression attenuated drug sensitivity. The in vivo experiments demonstrated that teroxirone suppressed growth of xenograft tumors in nude mice. Being a potential therapeutic agent by restraining cell growth through apoptotic death at low concentrations, teroxirone provides a feasible perspective in reversing tumorigenic phenotype of human lung cancer cells. - Highlights: • Teroxirone repressed tumor cell growth in nude mice of human lung cancer cells. • The apoptotic cell death reverted by caspase-3 inhibitor is related to p53 status. • Teroxirone provides a good candidate for lung cancer treatment.

  10. Commercial Application of a Photovoltaic Concentrator system. Phase I. Final report, 1 June 1978-28 February 1979

    SciTech Connect (OSTI)

    Anderson, D.J.; Anderson, E.R.; Bardwell, K.M.

    1980-04-01

    This report documents the design and analysis of the BDM CAPVC (Commercial Application of a Photovoltaic Concentrator) system. The preliminary design, prototype test and evaluation, system analysis, and final design of a large-scale concentrating photovoltaic system are described. The application is on an attractive new office building which represents a large potential market. The photovoltaic concentrating array is a roof-mounted, single-axis linear parabolic trough, using single crystalline silicon photovoltaic cells. A total of 6720 square feet of aperture is focussed on 13,944 PV cells. The photovoltaic system operates in parallel with the local utility in an augmentary loadsharing operating mode. The array is actively cooled and the thermal energy utilized for building heat during winter months. (WHK)

  11. Maternal exposure to metals—Concentrations and predictors of exposure

    SciTech Connect (OSTI)

    Callan, A.C., E-mail: a.callan@ecu.edu.au [Centre for Ecosystem Management, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027 (Australia); Hinwood, A.L.; Ramalingam, M.; Boyce, M. [Centre for Ecosystem Management, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027 (Australia)] [Centre for Ecosystem Management, Edith Cowan University, 270 Joondalup Drive, Joondalup, WA 6027 (Australia); Heyworth, J. [School Population Health, The University of Western Australia, 35 Stirling Highway Crawley, WA 6009 (Australia)] [School Population Health, The University of Western Australia, 35 Stirling Highway Crawley, WA 6009 (Australia); McCafferty, P. [ChemCentre, PO Box 1250, Bentley, WA 6983 (Australia)] [ChemCentre, PO Box 1250, Bentley, WA 6983 (Australia); Odland, J.Ø. [Department of Community Medicine, University of Tromsø, N-9037 Tromsø (Norway)] [Department of Community Medicine, University of Tromsø, N-9037 Tromsø (Norway)

    2013-10-15

    A variety of metals are important for biological function but have also been shown to impact health at elevated concentrations, whereas others have no known biological function. Pregnant women are a vulnerable population and measures to reduce exposure in this group are important. We undertook a study of maternal exposure to the metals, aluminium, arsenic, copper, cobalt, chromium, lithium, manganese, nickel, selenium, tin, uranium and zinc in 173 participants across Western Australia. Each participant provided a whole blood and urine sample, as well as drinking water, residential soil and dust samples and completed a questionnaire. In general the concentrations of metals in all samples were low with the notable exception of uranium (blood U mean 0.07 µg/L, range <0.01–0.25 µg/L; urinary U mean 0.018 µg/g creatinine, range <0.01–0.199 µg/g creatinine). Factors that influenced biological concentrations were consumption of fish which increased urinary arsenic concentrations, hobbies (including mechanics and welding) which increased blood manganese concentrations and iron/folic acid supplement use which was associated with decreased concentrations of aluminium and nickel in urine and manganese in blood. Environmental concentrations of aluminium, copper and lithium were found to influence biological concentrations, but this was not the case for other environmental metals concentrations. Further work is underway to explore the influence of diet on biological metals concentrations in more detail. The high concentrations of uranium require further investigation. -- Highlights: • High concentrations of uranium with respect to international literature. • Environmental concentrations of Al, Cu and Li influenced urinary concentrations. • Exposure to mechanics/welding hobbies increased blood Mn concentrations. • Iron/Folic acid supplements reduced biological concentrations of Al, Ni and Mn.

  12. AMMONIA CONCENTRATION IN SALTSTONE HEADSPACE SUMMARY REPORT

    SciTech Connect (OSTI)

    Zamecnik, J; Alex Cozzi, A

    2008-09-26

    The Saltstone Facility Documented Safety Analysis (DSA) is under revision to accommodate changes in the Composite Lower Flammability Limit (CLFL) from the introduction of Isopar into Tank 50. Saltstone samples were prepared with an 'MCU' type salt solution spiked with ammonia. The ammonia released from the saltstone was captured and analyzed. The ammonia concentration found in the headspace of samples maintained at 95 C and 1 atm was, to 95% confidence, less than or equal to 3.9 mg/L. Tank 50 is fed by several influent streams. The salt solution from Tank 50 is pumped to the salt feed tank (SFT) in the Saltstone Production Facility (SPF). The premix materials cement, slag and fly ash are blended together prior to transfer to the grout mixer. The premix is fed to the grout mixer in the SPF and the salt solution is incorporated into the premix in the grout mixer, yielding saltstone slurry. The saltstone slurry drops into a hopper and then is pumped to the vault. The Saltstone Facility Documented Safety Analysis (DSA) is under revision to accommodate changes in the Composite Lower Flammability Limit (CLFL) from the introduction of Isopar{reg_sign} L into Tank 50. Waste Solidification-Engineering requested that the Savannah River National Laboratory (SRNL) perform testing to characterize the release of ammonia in curing saltstone at 95 C. The test temperature represents the maximum allowable temperature in the Saltstone Disposal Facility (SDF). Ammonia may be present in the salt solution and premix materials, or may be produced by chemical reactions when the premix and salt solution are combined. A final report (SRNS-STI-2008-00120, Rev. 0) will be issued that will cover in more depth the information presented in this report.

  13. Method for detection of extremely low concentration

    DOE Patents [OSTI]

    Andresen, Brian D. (Livermore, CA); Miller, Fred S. (Bethal Island, CA)

    2002-01-01

    An ultratrace detector system for hand-held gas chromatography having high sensitivity, for example, to emissions generated during production of weapons, biological compounds, drugs, etc. The detector system is insensitive to water, air, helium, argon, oxygen, and CO.sub.2. The detector system is basically composed of a hand-held capillary gas chromatography (GC), an insulated heated redox-chamber, a detection chamber, and a vapor trap. For example, the detector system may use gas phase redox reactions and spectral absorption of mercury vapor. The gas chromatograph initially separates compounds that percolate through a bed of heated mercuric oxide (HgO) in a silica--or other metal--aerogel material which acts as an insulator. Compounds easily oxidized by HgO liberate atomic mercury that subsequently pass through a detection chamber which includes a detector cell, such as quartz, that is illuminated with a 254 nm ultra-violet (UV) mercury discharge lamp which generates the exact mercury absorption bands that are used to detect the liberated mercury atoms. Atomic mercury strongly absorbs 254 nm energy is therefore a specific signal for reducing compounds eluting from the capillary GC, whereafter the atomic mercury is trapped for example, in a silicon-aerogel trap.

  14. A new bioreactor system for animal cell culture 

    E-Print Network [OSTI]

    Monahan, Patrick Bernard

    1989-01-01

    constructed and its oxygen transfer properties evaluated. A series of alternately fixed and movable parallel disks, mounted such that the movable disks vibrate in a vertical direction at 30 Hz, serve ss the agitator. Pure oxygen, at pressures up to 5. 08... moderate agitation conditions using pure oxygen pressure of 5. 08 atm absolute. As more tubing is packed into the reactor, a greater cell concentration could be maintained. The predicted cell concentrations compare favorably with values found in previous...

  15. Salt Concentration Differences Alter Membrane Resistance in Reverse Electrodialysis Stacks

    E-Print Network [OSTI]

    Salt Concentration Differences Alter Membrane Resistance in Reverse Electrodialysis Stacks Geoffrey is usually measured by immersing the membrane in a salt solution at a single, fixed concentration. While salt resistance of the membranes separating different salt concentration solutions has implications for modeling

  16. High-Efficiency Solar Cells for Large-Scale Electricity Generation & Design Considerations for the Related Optics (Presentation)

    SciTech Connect (OSTI)

    Kurtz, S.; Olson, J.; Geisz, J.; Friedman, D.; McMahon, W.; Ptak, A.; Wanlass, M.k; Kibbler, A.; Kramer, C.; Ward, S.; Duda, A.; Young, M.; Carapella, J.

    2007-09-17

    The photovoltaic industry has been growing exponentially at an average rate of about 35%/year since 1979. Recently, multijunction concentrator cell efficiencies have surpassed 40%. Combined with concentrating optics, these can be used for electricity generation.

  17. Electrochemical cell

    DOE Patents [OSTI]

    Nagy, Z.; Yonco, R.M.; You, H.; Melendres, C.A.

    1992-08-25

    An electrochemical cell has a layer-type or sandwich configuration with a Teflon center section that houses working, reference and counter electrodes and defines a relatively narrow electrolyte cavity. The center section is surrounded on both sides with thin Teflon membranes. The membranes are pressed in place by a pair of Teflon inner frames which are in turn supported by a pair of outer metal frames. The pair of inner and outer frames are provided with corresponding, appropriately shaped slits that are in plane generally transverse to the plane of the working electrode and permit X-ray beams to enter and exit the cell through the Teflon membranes that cover the slits so that the interface between the working electrode and the electrolyte within the cell may be analyzed by transmission geometry. In one embodiment, the center section consists of two parts, one on top of the other. Alternatively, the center section of the electrochemical cell may consist of two intersliding pieces or may be made of a single piece of Teflon sheet material. The electrolyte cavity is shaped so that the electrochemical cell can be rotated 90[degree] in either direction while maintaining the working and counter electrodes submerged in the electrolyte. 5 figs.

  18. Low Concentration Photovoltaic Systems (LCPV), where solar irradiance is concentrated by a factor of 1-10, present

    E-Print Network [OSTI]

    Rollins, Andrew M.

    1 Abstract-- Low Concentration Photovoltaic Systems (LCPV), where solar irradiance is concentrated--concentrating photovoltaic, solar radiation durability, lifetime and degradation science, reliability. NOMENCLATURE LCPV: low modern society. As a direct method for harnessing the sun's energy, photovoltaic systems have a large

  19. Thermal concentrator homogenized with solar-shaped mantle

    E-Print Network [OSTI]

    Petiteau, David; Bellieud, Michel; Zerrad, Myriam; Amra, Claude

    2015-01-01

    We propose solar-shaped thermal concentrators designed with orthoradial layers and obtained in practice through the homogenization of an ideal thermal concentrator. Considering the spectral regime of the heat equation, we quantitatively evaluate at different pulsations the effectiveness of the homogenized concentrators by comparing the thermal flux existing in an ideal concentrator and the thermal flux in an homogenized concentrator. Dependence on the pulsation is shown to be negligible and plotting the effectiveness of the homogenized concentrators as a function of the number of orthoradial layers $N$, we determine the number of layers needed to achieve a certain effectiveness. Significantly high numbers $N$(ranging from a hundred to tens of thousands layers) are found highlighting the fact that achieving high effectiveness demands a high level of engineering of the homogenized concentrator.

  20. Photoelectrodialytic cell

    DOE Patents [OSTI]

    Murphy, George W. (2328 Ashwood, Norman, OK 73069)

    1983-01-01

    A multicompartment photoelectrodialytic demineralization cell is provided with a buffer compartment interposed between the product compartment and a compartment containing an electrolyte solution. Semipermeable membranes separate the buffer compartment from the product and electrolyte compartments. The buffer compartment is flushed to prevent leakage of the electrolyte compartment from entering the product compartment.

  1. Photoelectrodialytic cell

    DOE Patents [OSTI]

    Murphy, G.W.

    1983-09-13

    A multicompartment photoelectrodialytic demineralization cell is provided with a buffer compartment interposed between the product compartment and a compartment containing an electrolyte solution. Semipermeable membranes separate the buffer compartment from the product and electrolyte compartments. The buffer compartment is flushed to prevent leakage of the electrolyte compartment from entering the product compartment. 3 figs.

  2. Single element spectral splitting solar concentrator for multiple cells CPV system

    E-Print Network [OSTI]

    Stefancich, Marco

    Shockley Read Hall equation poses a limit to the maximum conversion efficiency of broadband solar radiation attainable by means of a single bandgap converter. A possible approach to overcome such a limit is to convert ...

  3. Low-Cost Photovoltaics: Luminescent Solar Concentrators And Colloidal Quantum Dot Solar Cells

    E-Print Network [OSTI]

    Leow, Shin Woei

    2014-01-01

    for building integrated photovoltaics,” 2013, vol. 8821, pp.of building integrated photovoltaics,” Sol. Energy, vol. 85,of building-integrated photovoltaics,” Energy, vol. 26, no.

  4. Influence of Fluid Velocity and Cell Concentration on the Transport of

    E-Print Network [OSTI]

    and Environmental Engineering, The Pennsylvania State University, 212 Sackett Building, University Park fluid velocity in a porous medium increases the number of collisions of passive colloids with particles/day). For passive colloids, the fractional retention (if R is a constant equal to 0.01) would increase by more than

  5. Solar spectral variations and their influence on concentrator solar cell performance

    E-Print Network [OSTI]

    Broderick, Lirong Z.

    A comparative study is performed to quantify the difference in efficiency and spectral sensitivity between a tandem junction and its spectrum splitting parallel junction counterpart. Direct normal solar spectra in a ...

  6. Low-Cost Photovoltaics: Luminescent Solar Concentrators And Colloidal Quantum Dot Solar Cells

    E-Print Network [OSTI]

    Leow, Shin Woei

    2014-01-01

    J. Nozik, “Third Generation Photovoltaics based on Multiple8].Applications in third generation photovoltaics have the

  7. Effects of Spectral Error in Efficiency Measurements of GaInAs-Based Concentrator Solar Cells

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansas Nuclear Profile 2010MesoscopyStaff »VehicleEffectiveEffects of Spectral

  8. Low concentrations of bisphenol a suppress thyroid hormone receptor transcription through a nongenomic mechanism

    SciTech Connect (OSTI)

    Sheng, Zhi-Guo; Tang, Yuan; Liu, Yu-Xiang; Yuan, Ye; Zhao, Bao-Quan; Chao, Xi-Juan; Zhu, Ben-Zhan

    2012-02-15

    Bisphenol (BPA) is one of the highest-volume chemicals produced worldwide, and human exposure to BPA is thought to be ubiquitous. Various rodent and in vitro studies have shown that thyroid hormone (TH) function can be impaired by BPA. However, it is still unknown if low concentrations of BPA can suppress the thyroid hormone receptor (TR) transcription. The present study aims to investigate the possible suppressing effects of low concentrations of BPA on TR transcription and the involved mechanism(s) in CV-1 cells derived from cercopithecus aethiops monkey kidneys. Using gene reporter assays, BPA at concentrations as low as 10{sup ?9} M suppresses TR or steroid receptor coactivator-1(SRC-1)-enhanced TR transcription, but not reducing TR/SRC-1 interaction in mammalian two-hybrid and glutathione S-transferase pull-down studies. It has been further shown that both nuclear receptor co-repressor (N-CoR) and silencing mediator for retinoid and thyroid hormone receptors (SMRT) are recruited to the TR-?1 by BPA in the presence of physiologic concentrations of T3 or T4. However, the overexpression of ?3 integrin or c-Src significantly reduces BPA-induced recruitment of N-CoR/SMRT to TR or suppression of TR transcription. Furthermore, BPA inhibits the T3/T4-mediated interassociation of the ?3 integrin/c-Src/MAPK/TR-?1 pathways by the co-immunoprecipitation. These results indicate that low concentrations of BPA suppress the TR transcription by disrupting physiologic concentrations of T3/T4-mediated ?3 integrin/c-Src/MAPK/TR-?1 pathways, followed by recruiting N-CoR/SMRT to TR-?1, providing a novel insight regarding the TH disruption effects of low concentration BPA. -- Highlights: ? Environmentally relevant concentrations of BPA suppress TR transcription. ? BPA recruits the N-CoR/SMRT to TR under the physiologic concentrations of T3/T4. ? BPA disrupts T3/T4-mediated ?3 integrin/c-Src/MAPK/TR-?1 pathways.

  9. CPV Cell Infant Mortality Study: Preprint

    SciTech Connect (OSTI)

    Bosco, N.; Sweet, C.; Silverman, T.; Kurtz, S.

    2011-05-01

    Six hundred and fifty CPV cells were characterized before packaging and then after a four-hour concentrated on-sun exposure. An observed fielded infant mortality failure rate was reproduced and attributed to epoxy die-attach voiding at the corners of the cells. These voids increase the local thermal resistance allowing thermal runaway to occur under normal operation conditions in otherwise defect-free cells. FEM simulations and experiments support this hypothesis. X-ray transmission imaging of the affected assemblies was not found capable of detecting all suspect voids and therefore cannot be considered a reliable screening technique in the case of epoxy die-attach.

  10. Solid-polymer-electrolyte fuel cells

    SciTech Connect (OSTI)

    Fuller, T.F.

    1992-07-01

    A transport model for polymer electrolytes is presented, based on concentrated solution theory and irreversible thermodynamics. Thermodynamic driving forces are developed, transport properties are identified and experiments devised. Transport number of water in Nafion 117 membrane is determined using a concentration cell. It is 1.4 for a membrane equilibrated with saturated water vapor at 25{degrees}C, decreases slowly as the membrane is dehydrated, and falls sharply toward zero as the water content approaches zero. The relation between transference number, transport number, and electroosmotic drag coefficient is presented, and their relevance to water-management is discussed. A mathematical model of transport in a solid-polymer-electrolyte fuel cell is presented. A two-dimensional membrane-electrode assembly is considered. Water management, thermal management, and utilization of fuel are examined in detail. The membrane separators of these fuel cells require sorbed water to maintain conductivity; therefore it is necessary to manage the water content in membranes to ensure efficient operation. Water and thermal management are interrelated. Rate of heat removal is shown to be a critical parameter in the operation of these fuel cells. Current-voltage curves are presented for operation on air and reformed methanol. Equations for convective diffusion to a rotating disk are solved numerically for a consolute point between the bulk concentration and the surface. A singular-perturbation expansion is presented for the condition where the bulk concentration is nearly equal to the consolute-point composition. Results are compared to Levich's solution and analysis.

  11. Fuel Cells Bulletin February 2005 Effect of methanol

    E-Print Network [OSTI]

    Zhao, Tianshou

    FEATURE Fuel Cells Bulletin February 2005 12 Effect of methanol concentration on passive DMFC performance The direct methanol fuel cell (DMFC) has attracted extensive interest from scientists energy density of methanol (6100 W h/kg at 25°C) is much higher than that of gaseous fuels.[1­6] Recently

  12. THERMOCHEMICAL HEAT STORAGE FOR CONCENTRATED SOLAR POWER

    SciTech Connect (OSTI)

    PROJECT STAFF

    2011-10-31

    Thermal energy storage (TES) is an integral part of a concentrated solar power (CSP) system. It enables plant operators to generate electricity beyond on sun hours and supply power to the grid to meet peak demand. Current CSP sensible heat storage systems employ molten salts as both the heat transfer fluid and the heat storage media. These systems have an upper operating temperature limit of around 400 C. Future TES systems are expected to operate at temperatures between 600 C to 1000 C for higher thermal efficiencies which should result in lower electricity cost. To meet future operating temperature and electricity cost requirements, a TES concept utilizing thermochemical cycles (TCs) based on multivalent solid oxides was proposed. The system employs a pair of reduction and oxidation (REDOX) reactions to store and release heat. In the storage step, hot air from the solar receiver is used to reduce the oxidation state of an oxide cation, e.g. Fe3+ to Fe2+. Heat energy is thus stored as chemical bonds and the oxide is charged. To discharge the stored energy, the reduced oxide is re-oxidized in air and heat is released. Air is used as both the heat transfer fluid and reactant and no storage of fluid is needed. This project investigated the engineering and economic feasibility of this proposed TES concept. The DOE storage cost and LCOE targets are $15/kWh and $0.09/kWh respectively. Sixteen pure oxide cycles were identified through thermodynamic calculations and literature information. Data showed the kinetics of re-oxidation of the various oxides to be a key barrier to implementing the proposed concept. A down selection was carried out based on operating temperature, materials costs and preliminary laboratory measurements. Cobalt oxide, manganese oxide and barium oxide were selected for developmental studies to improve their REDOX reaction kinetics. A novel approach utilizing mixed oxides to improve the REDOX kinetics of the selected oxides was proposed. It partially replaces some of the primary oxide cations with selected secondary cations. This causes a lattice charge imbalance and increases the anion vacancy density. Such vacancies enhance the ionic mass transport and lead to faster re-oxidation. Reoxidation fractions of Mn3O4 to Mn2O3 and CoO to Co3O4 were improved by up to 16 fold through the addition of a secondary oxide. However, no improvement was obtained in barium based mixed oxides. In addition to enhancing the short term re-oxidation kinetics, it was found that the use of mixed oxides also help to stabilize or even improve the TES properties after long term thermal cycling. Part of this improvement could be attributed to a reduced grain size in the mixed oxides. Based on the measurement results, manganese-iron, cobalt-aluminum and cobalt iron mixed oxides have been proposed for future engineering scale demonstration. Using the cobalt and manganese mixed oxides, we were able to demonstrate charge and discharge of the TES media in both a bench top fixed bed and a rotary kiln-moving bed reactor. Operations of the fixed bed configuration are straight forward but require a large mass flow rate and higher fluid temperature for charging. The rotary kiln makes direct solar irradiation possible and provides significantly better heat transfer, but designs to transport the TES oxide in and out of the reactor will need to be defined. The final reactor and system design will have to be based on the economics of the CSP plant. A materials compatibility study was also conducted and it identified Inconel 625 as a suitable high temperature engineering material to construct a reactor holding either cobalt or manganese mixed oxides. To assess the economics of such a CSP plant, a packed bed reactor model was established as a baseline. Measured cobalt-aluminum oxide reaction kinetics were applied to the model and the influences of bed properties and process parameters on the overall system design were investigated. The optimal TES system design was found to be a network of eight fixed bed reactors at 18.75 MWth each with charge and

  13. Status report on a solar photovoltaic concentrating energy system for a hospital in Hawaii

    SciTech Connect (OSTI)

    Seki, A.; Curtis, G.; Yuen, P.

    1983-06-01

    The largest parabolic concentrating photovoltaic/solar thermal system in the U.S. began producing electricity and hot water for a hospital on the island of Kauai, Hawaii in November 1981. Each of the 80 parabolic collectors is 6 feet by 10 feet and concentrates incident sunlight on photovoltaic cells mounted on two faces of the receiver at the focus. Although the 35 kilowatt system has been designed to produce 22,000 net kilowatt-hours per year of electricity and 620,000 gallons of 180 F water, electrical output (12 to 15 kilowatt-hours per day) is only 20 percent of that expected, primarily because insolation at the site has been only 40 percent of predicted values. A second problem with fungal attack on the receivers has been solved by better sealing. The system has also withstood a hurricane with negligible damage.

  14. Separation and concentration of hydrogen isotopes by a palladium alloy membrane

    SciTech Connect (OSTI)

    Suzuki, Yasuo ); Kimura, Shoji )

    1993-07-01

    A continuous membrane column process that uses a palladium alloy membrane for the separation of hydrogen isotopes is studied. Hydrogen, deuterium, and tritium permeation rates obtained in previous studies are used in numerical calculations in which the nature of the membrane column is investigated through variations in the operation variables, such as the pressures and their ratio, the reflux ratio, and the stripping column velocity. Finally, a cascade design in which membrane columns are used as unit cells is developed, following a design study of a nuclear fusion reactor fuel cycle system, and the concentrations and flow rates are calculated. The results show that hydrogen, deuterium, and tritium can be separated and concentrated as well by this method as by the liquid hydrogen distillation process. The inventory of the membrane column process is also calculated, and it is [approximately]2.3 times the fuel processed in a day.

  15. Nanocrystal Solar Cells

    E-Print Network [OSTI]

    Gur, Ilan

    2006-01-01

    research on organic photovoltaic cells since small molecule10 years prior (4). Photovoltaic cells with an active layerof the associated photovoltaic cells. 2.4 Charge transport

  16. Hydrogen Fuel Cell Vehicles

    E-Print Network [OSTI]

    Delucchi, Mark

    1992-01-01

    Reforming for Molten Carbonate Fuel Cells," Berichte derVan Dijkum, "The Molten Carbonate Fuel Cell Programme in thealkaline, molten carbonate, and solid oxide. (Fuel cells

  17. Nanocrystal Solar Cells

    E-Print Network [OSTI]

    Gur, Ilan

    2006-01-01

    Nov, 2005). Chapter 4 Hybrid solar cells with 3-dimensionalinorganic nanocrystal solar cells 5.1 Introduction In recentoperation of organic based solar cells and distinguish them

  18. Nanocrystal Solar Cells

    E-Print Network [OSTI]

    Gur, Ilan

    2006-01-01

    nanocrystal-polymer solar cells The full potential of hybridto reach the full potential of polymer blend solar cells.solar cells described here offer several potential

  19. Diagnostic Studies on Lithium Battery Cells and Cell Components...

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

    Studies on Lithium Battery Cells and Cell Components Diagnostic Studies on Lithium Battery Cells and Cell Components 2012 DOE Hydrogen and Fuel Cells Program and Vehicle...

  20. Hydrogen and Fuel Cell Technologies Program: Fuel Cells Fact...

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

    Hydrogen and Fuel Cell Technologies Program: Fuel Cells Fact Sheet Hydrogen and Fuel Cell Technologies Program: Fuel Cells Fact Sheet Fact sheet produced by the Fuel Cell...

  1. Method and apparatus for concentrating vapors for analysis

    DOE Patents [OSTI]

    Grate, Jay W. (West Richland, WA); Baldwin, David L. (Kennewick, WA); Anheier, Jr., Norman C. (Richland, WA)

    2012-06-05

    A pre-concentration device and a method are disclosed for concentrating gaseous vapors for analysis. Vapors sorbed and concentrated within the bed of the pre-concentration device are thermally desorbed, achieving at least partial separation of the vapor mixtures. The pre-concentration device is suitable, e.g., for pre-concentration and sample injection, and provides greater resolution of peaks for vapors within vapor mixtures, yielding detection levels that are 10-10,000 times better than direct sampling and analysis systems. Features are particularly useful for continuous unattended monitoring applications. The invention finds application in conjunction with, e.g., analytical instruments where low detection limits for gaseous vapors are desirable.

  2. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    ing ?uorescent dye for solar energy conversion based on aimprove the the solar energy conversion e?ciency. Outputcheaper solar energy concentration and conversion methods,

  3. Focusing particle concentrator with application to ultrafine particles

    DOE Patents [OSTI]

    Hering, Susanne; Lewis, Gregory; Spielman, Steven R.

    2013-06-11

    Technology is presented for the high efficiency concentration of fine and ultrafine airborne particles into a small fraction of the sampled airflow by condensational enlargement, aerodynamic focusing and flow separation. A nozzle concentrator structure including an acceleration nozzle with a flow extraction structure may be coupled to a containment vessel. The containment vessel may include a water condensation growth tube to facilitate the concentration of ultrafine particles. The containment vessel may further include a separate carrier flow introduced at the center of the sampled flow, upstream of the acceleration nozzle of the nozzle concentrator to facilitate the separation of particle and vapor constituents.

  4. National Laboratory Concentrating Solar Power Research and Development

    Office of Environmental Management (EM)

    Concentrating Solar Power Research and Development Motivation The U.S. Department of Energy (DOE) launched the SunShot Initiative as a collaborative national endeavor to make...

  5. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    and V.U. Ho?mann. Photovoltaic Solar Energy Gen- eration.Concentrations for Photovoltaic Technologies A dissertationThirteenth IEEE Photovoltaic Specialists Conference- 1978—

  6. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    by one-sun solar simulator. . . . . . . . . . . . . . .two kinds of solar concentrators, one is based on geomet-to utilize the whole solar spectrum, one of the methods is

  7. Transfer Printed Microcells with Micro-Optic Concentrators for...

    Office of Scientific and Technical Information (OSTI)

    Printed Microcells with Micro-Optic Concentrators for Low Cost, High Performance Photovoltaic Modules Citation Details In-Document Search Title: Transfer Printed Microcells with...

  8. Concentrating Solar Power: Solar Energy Technologies Program (SETP) (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2009-10-01

    Fact sheet summarizing the goals and activities of the DOE Solar Energy Technologies Program efforts within its concentrating solar power subprogram.

  9. Two linear slot nozzle virtual impactors for concentration of bioaerosols 

    E-Print Network [OSTI]

    Haglund, John Steven

    2005-02-17

    Two experimental configurations of linear slot nozzle virtual impactors were constructed and experimentally investigated for use as bioaerosol concentrators. In one configuration, the Linear Slot Virtual Impactor (LSVI), ...

  10. Evaluation of alkali concentration in conditions relevant to...

    Office of Scientific and Technical Information (OSTI)

    Evaluation of alkali concentration in conditions relevant to oxygennatural gas glass furnaces by laser-induced breakdown spectroscopy. Citation Details In-Document Search Title:...

  11. Hybrid fs/ps Rotational CARS Temperature and Concentration Measurement...

    Office of Scientific and Technical Information (OSTI)

    Hybrid fsps Rotational CARS Temperature and Concentration Measurements Using Two Different ps-Duration Probe Beams. Citation Details In-Document Search Title: Hybrid fsps...

  12. Domestic Material Content in Molten-Salt Concentrating Solar...

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

    Domestic Material Content in Molten-Salt Concentrating Solar Power Plants Craig Turchi, Parthiv Kurup, Sertac Akar, and Francisco Flores Technical Report NRELTP-5500-64429 August...

  13. HYDROGEN CONCENTRATION AND DISTRIBUTION IN HIGH-PURITY GERMANIUM CRYSTALS

    E-Print Network [OSTI]

    Hansen, W.L.

    2010-01-01

    melting point. By analogy, hydrogen permeation measurementsin silicon suggest that the hydrogen solubility also is notNo. 1, February 1982 HYDROGEN CONCENTRATION AND DISTRIBUTION

  14. World's Largest Concentrating Solar Power Plant Opens in California...

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

    Ivanpah, the world's largest concentrating solar plant, opened in California on February 13.Credit: BrightSource Energy The Ivanpah Solar Electric Generating System, the world's...

  15. Low Cost High Concentration PV Systems for Utility Power Generation...

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

    Residential and Utility Solar Power Generating Systems SunPower,Low Cost Thin Film Building-Integrated PV Systems Low Cost High Concentration PV Systems for Utility Power...

  16. Phenylnaphthalene as a Heat Transfer Fluid for Concentrating...

    Office of Scientific and Technical Information (OSTI)

    Technical Report: Phenylnaphthalene as a Heat Transfer Fluid for Concentrating Solar Power: High-Temperature Static Experiments Citation Details In-Document Search Title:...

  17. Energy Department Announces $25 Million to Lower Cost of Concentrating...

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

    clean and renewable energy, even at night, by storing the heat generated by the sun. "Investments to improve the efficiency and lower the costs of concentrating solar...

  18. Low-Cost Light Weigh Thin Film Solar Concentrators

    Broader source: Energy.gov [DOE]

    This presentation was delivered at the SunShot Concentrating Solar Power (CSP) Program Review 2013, held April 23–25, 2013 near Phoenix, Arizona.

  19. Concentrating Solar Power Facilities and Solar Potential | Department...

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

    Type All Plants In Operation New in 2014 In Progress Tower and Heliostat Trough or Fresnel Parabolic Dish Concentrating Solar Energy Potential (watt hoursmday) 2500 4000...

  20. $60 Million to Fund Projects Advancing Concentrating Solar Power

    Broader source: Energy.gov [DOE]

    The SunShot initiative announces a $60 million funding opportunity (FOA) to advance concentrating solar power in the United States.

  1. Method of trivalent chromium concentration determination by atomic spectrometry

    DOE Patents [OSTI]

    Reheulishvili, Aleksandre N. (Tbilisi, 0183, GE); Tsibakhashvili, Neli Ya. (Tbilisi, 0101, GE)

    2006-12-12

    A method is disclosed for determining the concentration of trivalent chromium Cr(III) in a sample. The addition of perchloric acid has been found to increase the atomic chromium spectrometric signal due to Cr(III), while leaving the signal due to hexavalent chromium Cr(VI) unchanged. This enables determination of the Cr(III) concentration without pre-concentration or pre-separation from chromium of other valences. The Cr(III) concentration may be measured using atomic absorption spectrometry, atomic emission spectrometry or atomic fluorescence spectrometry.

  2. Electrochemical cell

    SciTech Connect (OSTI)

    Walsh, F.M.

    1986-12-23

    This patent describes an electrochemical cell having a metal anode wherein the metal is selected from zinc and cadmium; a bromine cathode; and an aqueous electrolyte containing a metal bromide, the metal bromide having the same metal as the metal of the anode. The improvement described here comprises: a bromine complexing agent in the aqueous metal bromide electrolyte, the complexing agent consisting solely of a quaternary ammonium salt of an N-organo substituted alpha amino acid, ester, or betaine.

  3. Multi-crystalline II-VI based multijunction solar cells and modules

    DOE Patents [OSTI]

    Hardin, Brian E.; Connor, Stephen T.; Groves, James R.; Peters, Craig H.

    2015-06-30

    Multi-crystalline group II-VI solar cells and methods for fabrication of same are disclosed herein. A multi-crystalline group II-VI solar cell includes a first photovoltaic sub-cell comprising silicon, a tunnel junction, and a multi-crystalline second photovoltaic sub-cell. A plurality of the multi-crystalline group II-VI solar cells can be interconnected to form low cost, high throughput flat panel, low light concentration, and/or medium light concentration photovoltaic modules or devices.

  4. SunLab: Concentrating Solar Power Program Overview

    SciTech Connect (OSTI)

    1998-11-24

    DOE's Concentrating Solar Power (CSP) program is collaborating with its partners in the private sector to develop two new solar technologies -- power towers and dish/engines -- to meet the huge commercial potential for solar power. Concentrating solar power plants produce electric power by first converting the sun's energy into heat, and then to electricity in a conventional generator.

  5. Concentrated Photovoltaic Systems Center for Energy Research at

    E-Print Network [OSTI]

    Hemmers, Oliver

    Amonix Concentrated Photovoltaic Systems Center for Energy Research at UNLV #12;A State-of-the-Art Solar Power System Center for Energy Research at UNLV The most common photovoltaic (PV) systems-Concentration Photovoltaic System. Manufactured by AmonixTM, the first MegamoduleTM system ­ Model 5500 ­ was a single

  6. Paleoclimatic warming increased carbon dioxide concentrations D. M. Lemoine1

    E-Print Network [OSTI]

    Kammen, Daniel M.

    Paleoclimatic warming increased carbon dioxide concentrations D. M. Lemoine1 Received 6 July 2010 feedbacks are positive, then warming causes changes in carbon dioxide (CO2) sources and sinks that increase increased carbon dioxide concentrations, J. Geophys. Res., 115, D22122, doi:10.1029/2010JD014725. 1

  7. Master of Arts in Psychology PSYCHOLOGY CONCENTRATION CHOICE & RESEARCH INTERESTS

    E-Print Network [OSTI]

    Olszewski Jr., Edward A.

    Master of Arts in Psychology PSYCHOLOGY CONCENTRATION CHOICE & RESEARCH INTERESTS Directions. Please indicate the concentration to which you are applying: General Psychology (GEN) Applied Behavior Analysis (ABA) Substance Abuse Treatment Psychology (SATP) 2. Using a scale of 1 to 5 (where 1

  8. URBAN OZONE CONCENTRATION FORECASTING WITH ARTIFICIAL NEURAL NETWORK IN CORSICA

    E-Print Network [OSTI]

    Boyer, Edmond

    Perceptron; Ozone concentration. 1. Introduction Tropospheric ozone is a major air pollution problem, both, Ajaccio, France, e-mail: balu@univ-corse.fr Abstract: Atmospheric pollutants concentration forecasting is an important issue in air quality monitoring. Qualitair Corse, the organization responsible for monitoring air

  9. Optical design and efficiency improvement for organic luminescent solar concentrators

    E-Print Network [OSTI]

    Hirst, Linda

    in a standard flat-plate PV panel3 . Nonimaging Optics: Efficient Design for Illumination and SolarOptical design and efficiency improvement for organic luminescent solar concentrators Chunhua Wanga and efficiency improvement method. Keywords: Organic luminescent solar concentrators, Photovoltaic, solar energy

  10. Shape-Adaptive Ultra-Lightweight Solar Concentrators

    E-Print Network [OSTI]

    RESEARCH HIGHLIGHTS Shape-Adaptive Ultra-Lightweight Solar Concentrators From the Resnick-Lightweight Solar Concentrators Global Significance Solar energy offers a number of benefits such as reducing solar power (CSP) uses mirrors to focus the sunlight down to 100-1000x the normal intensity, and uses

  11. Geometries of inhomogeneities with minimum field concentration Liping Liua,1

    E-Print Network [OSTI]

    Liu, Liping

    of these new geometries. Keywords: Stress concentration, E-inclusion, Optimal design This work is dedicated criteria of materials are often formulated in terms of "yield stress" or "ultimate stress", meaning- fore, a precise analysis of field concentration is critical for the safety and reliability

  12. Filtering of Calcium Transients by the Endoplasmic Reticulum in Pancreatic b-Cells

    E-Print Network [OSTI]

    Filtering of Calcium Transients by the Endoplasmic Reticulum in Pancreatic b-Cells Richard Bertram in pancreatic b-cells is important for intracellular signaling, the control of electrical activity, and insulin-dependent data on the free Ca21 concentration in pancreatic islets and b-cell clusters can be explained

  13. An Elasto-visco-plastic Model of Cell Aggregates L. Preziosi

    E-Print Network [OSTI]

    Preziosi, Luigi

    elasto­visco­plastic model which is able to describe the mechanical properties of a concentrated cellAn Elasto-visco-plastic Model of Cell Aggregates L. Preziosi Department of Mathematics]. On the other hand, it is known that the intrinsic properties of the base components - cells and collagen

  14. Transcriptional Regulation of Germinal Center B and Plasma Cell Fates by Dynamical Control of IRF4

    E-Print Network [OSTI]

    Dinner, Aaron

    Immunity Article Transcriptional Regulation of Germinal Center B and Plasma Cell Fates by Dynamical factor IRF4 regulates immuno- globulin class switch recombination and plasma cell differentiation. Its differing concentrations appear to regulate mutually antagonistic programs of B and plasma cell gene

  15. Effects of Highly Non-uniform Illumination Distribution on Electrical Performance of Solar Cells

    E-Print Network [OSTI]

    Effects of Highly Non-uniform Illumination Distribution on Electrical Performance of Solar Cells E and prediction of performance for a cell under concentrated illumination is to assume that the flux distribution of resistance within a conventional front-illuminated solar cell are the metal grid, the finger/emitter contacts

  16. A non-isothermal PEM fuel cell model including two water transport mechanisms in the

    E-Print Network [OSTI]

    Münster, Westfälische Wilhelms-Universität

    A non-isothermal PEM fuel cell model including two water transport mechanisms in the membrane K Freiburg Germany A dynamic two-phase flow model for proton exchange mem- brane (PEM) fuel cells and the species concentrations. In order to describe the charge transport in the fuel cell the Poisson equations

  17. Methanol adsorbates on the DMFC cathode and their effect on the cell performance

    E-Print Network [OSTI]

    Zhao, Tianshou

    Methanol adsorbates on the DMFC cathode and their effect on the cell performance J. Prabhuram, T in the performance of a direct methanol fuel cell (DMFC) occurred after the cell had been operated at a higher temperature with higher methanol concentrations as compared with the polarization data collected under

  18. ORIGINAL ARTICLE Highly efficient GaAs solar cells by limiting light emission

    E-Print Network [OSTI]

    Polman, Albert

    a non-concentrating system with limited emission angle in a thin, light trapping GaAs solar cellORIGINAL ARTICLE Highly efficient GaAs solar cells by limiting light emission angle Emily D Kosten1 of a high-quality GaAs solar cell is a feasible route to achieving power conversion efficiencies above 38

  19. Concentration-Temperature Superposition of Helix Folding Rates in Gelatin

    E-Print Network [OSTI]

    J. L. Gornall; E. M. Terentjev

    2006-03-05

    We study the kinetics of helix-coil transition in water solutions of gelatin (collagen protein) by optical rotation techniques combined with thermal characterization. By examining the rates of secondary helix folding, and covering a very wide range of solution concentrations, we are able to identify a universal exponential dependence of folding rate on concentration and quench temperature. We demonstrate a new concentration-temperature superposition of data at all temperatures and concentrations, and build the corresponding master curve. The results support the concept of a diffuse helix-coil transition. We find no concentration dependance of the normalized rate constant, suggesting first order (single) kinetics of secondary helix folding dominate in the early stages of renaturation.

  20. A new trough solar concentrator and its performance analysis

    SciTech Connect (OSTI)

    Tao, Tao; Hongfei, Zheng; Kaiyan, He; Mayere, Abdulkarim

    2011-01-15

    The operation principle and design method of a new trough solar concentrator is presented in this paper. Some important design parameters about the concentrator are analyzed and optimized. Their magnitude ranges are given. Some characteristic parameters about the concentrator are compared with that of the conventional parabolic trough solar concentrator. The factors having influence on the performance of the unit are discussed. It is indicated through the analysis that the new trough solar concentrator can actualize reflection focusing for the sun light using multiple curved surface compound method. It also has the advantages of improving the work performance and environment of high-temperature solar absorber and enhancing the configuration intensity of the reflection surface. (author)

  1. Cell Stem Cell Sic Transit Gloria

    E-Print Network [OSTI]

    Simons, Ben

    Cell Stem Cell Review Sic Transit Gloria: Farewell to the Epidermal Transit Amplifying Cell? Philip H. Jones,1,* Benjamin D. Simons,2 and Fiona M. Watt3,4 1MRC Cancer Cell Unit, Hutchison-MRC Research basement membrane (Figures 1D and 1F). On commitment to terminal differen- tiation, basal keratinocytes

  2. 6/06/09 BS in Biology, Concentration in Microbiology Bachelor of Science in Biology: Concentration in Microbiology

    E-Print Network [OSTI]

    6/06/09 BS in Biology, Concentration in Microbiology Bachelor of Science in Biology: Concentration in Microbiology Department of Biology College of Science and Engineering Undergraduate Programs Microbiology, but also in chemistry, physics, mathematics, and other areas of biology. Within the undergraduate program

  3. System for adding sulfur to a fuel cell stack system for improved fuel cell stability

    DOE Patents [OSTI]

    Mukerjee, Subhasish; Haltiner, Jr., Karl J; Weissman, Jeffrey G

    2013-08-13

    A system for adding sulfur to a reformate stream feeding a fuel cell stack, having a sulfur source for providing sulfur to the reformate stream and a metering device in fluid connection with the sulfur source and the reformate stream. The metering device injects sulfur from the sulfur source to the reformate stream at a predetermined rate, thereby providing a conditioned reformate stream to the fuel cell stack. The system provides a conditioned reformate stream having a predetermined sulfur concentration that gives an acceptable balance of minimal drop in initial power with the desired maximum stability of operation over prolonged periods for the fuel cell stack.

  4. Discharge cell for ozone generator

    DOE Patents [OSTI]

    Nakatsuka, Suguru (Amagasaki, JP)

    2000-01-01

    A discharge cell for use in an ozone generator is provided which can suppress a time-related reduction in ozone concentration without adding a catalytic gas such as nitrogen gas to oxygen gas as a raw material gas. The discharge cell includes a pair of electrodes disposed in an opposed spaced relation with a discharge space therebetween, and a dielectric layer of a three-layer structure consisting of three ceramic dielectric layers successively stacked on at least one of the electrodes, wherein a first dielectric layer of the dielectric layer contacting the one electrode contains no titanium dioxide, wherein a second dielectric layer of the dielectric layer exposed to the discharge space contains titanium dioxide in a metal element ratio of not lower than 10 wt %.

  5. (Fuel Cells)(Fuel Cells) William Grove

    E-Print Network [OSTI]

    Chen, Yang-Yuan

    Fuel Cell #12; H2 O2 Power CH4 H2 Toyota H2 H2 #12; H2 ~253 #12; 2. 3. : 1. #12; #12;Fuel Cell #12; (Fuel Cells)(Fuel Cells) 1839 William Grove A H2O2 H2O2 2H; Fuel Cell #12;!! PEMFC DMFC SOFC (60~200) (60~100) (600~1000) #12; Proton

  6. A mathematical method for extracting cell secretion rate from affinity biosensors continuously monitoring cell activity

    E-Print Network [OSTI]

    Revzin, Alexander

    A mathematical method for extracting cell secretion rate from affinity biosensors continuously-sensing biosensor for detection of biological species at ultralow concentrations J. Appl. Phys. 113, 224905 (2013); 10.1063/1.4807832 Gold coating of micromechanical DNA biosensors by pulsed laser deposition J. Appl

  7. Treatment of concentrated industrial wastewaters originating from oil shale and the like by electrolysis polyurethane foam interaction

    DOE Patents [OSTI]

    Tiernan, Joan E. (38 Clay Ct., Novato, CA 94947)

    1991-01-01

    Highly concentrated and toxic petroleum-based and synthetic fuels wastewaters such as oil shale retort water are treated in a unit treatment process by electrolysis in a reactor containing oleophilic, ionized, open-celled polyurethane foams and subjected to mixing and l BACKGROUND OF THE INVENTION The invention described herein arose in the course of, or under, Contract No. DE-AC03-76SF00098 between the U.S. Department of Energy and the University of California.

  8. Concentration Independent Modulation of Local Micromechanics in a Fibrin Gel

    E-Print Network [OSTI]

    2011-01-01

    Sun SX, Wirtz D (2008) Mapping local matrix remodeling induced by a migrating tumor cell using three-dimensional multiple-particle tracking.

  9. Dust size distribution and concentrations with cottonseed oil mills 

    E-Print Network [OSTI]

    Wiederhold, Lee Roy

    1976-01-01

    -VOLUME SAMPLES FOR P. S. D OF PARTICLES & 100 um DIAMETER (MMD) ANALYSIS OF VARIANCE ON HIGH-VOLUME SAMPLES FOR P. S. D. OF PARTICLES & 100 um DIAMETER (og) MULTIPLE RANGE TEST FOR MEAN VALUES OF MMD BY AREA MULTIPLE RANGE TEST OF MMD BY MILL PARTICLE SIZE... TEST OF AREA DUST CONCENTRATIONS = 15 Pm IN DIAMETER MULTIPLE RANGE TEST OF MILL DUST CONCENTRATIONS & 15 um IN DIAMETER ANALYSIS OF VARIANCE ON PARTICLE SIZING HEAD SAMPLES OF CONCENTRATIONS FOR PARTICLES & 100 IJBI DIAMETER . . . . 47 47 54...

  10. The relation of seismic activity and radon concentration

    SciTech Connect (OSTI)

    Kulali, Feride E-mail: iskender@fef.sdu.edu.tr; Akkurt, ?skender E-mail: iskender@fef.sdu.edu.tr; Vogiannis, Efstratios

    2014-10-06

    Radon, which is the largest source of natural ionizing radiation, reaches to surface as gas or dissolved form in the ground water. Emanation of radon can has a profile is disposed to increasing or decreasing depending on the effects of meteorological events or crust movements. In this work, the radon concentration in soil gas, which is transported from soil to AlphaGUARD, is continuously measured in Mytilene (Greece). A graph of radon concentration is prepared for comparison with simultaneous earthquake data. As a consequence of comparison, we determined that the radon concentration indicates anomalies before the earthquakes.

  11. Ion Concentration Dynamics as a Mechanism for Neuronal Bursting

    E-Print Network [OSTI]

    Ernest Barreto; John R. Cressman

    2011-09-21

    We describe a simple conductance-based model neuron that includes intra- and extra-cellular ion concentration dynamics and show that this model exhibits periodic bursting. The bursting arises as the fast spiking behavior of the neuron is modulated by the slow oscillatory behavior in the ion concentration variables, and vice versa. By separating these time scales and studying the bifurcation structure of the neuron, we catalog several qualitatively different bursting profiles that are strikingly similar to those seen in experimental preparations. Our work suggests that ion concentration dynamics may play an important role in modulating neuronal excitability in real biological systems.

  12. Design of photovoltaic central power station concentrator array

    SciTech Connect (OSTI)

    Not Available

    1984-02-01

    A design for a photovoltaic central power station using tracking concentrators has been developed. The 100 MW plant is assumed to be located adjacent to the Saguaro Power Station of Arizona Public Service. The design assumes an advanced Martin Marietta two-axis tracking fresnel lens concentrator. The concentrators are arrayed in 5 MW subfields, each with its own power conditioning unit. The photovoltaic plant output is connected to the existing 115 kV switchyard. The site specific design allows detailed cost estimates for engineering, site preparation, and installation. Collector and power conditioning costs have been treated parametrically.

  13. The effect of sub-minimum inhibitory concentration of ciprofloxacin concentrations on enteroaggregative Escherichia coli and the role of the surface protein dispersin

    SciTech Connect (OSTI)

    Mortensen, Ninell P [ORNL; Fowlkes, Jason Davidson [ORNL; Trevino-Dopatka, Sonia [ORNL; Maggart, Michael J [ORNL; Boisen, Nadia [University of Virginia School of Medicine; Doktycz, Mitchel John [ORNL; Nataro, James [University of Virginia School of Medicine; Allison, David P [ORNL

    2011-01-01

    Enteroaggregative Escherichia coli (EAEC) are bacterial pathogens that cause watery diarrhea, which is often persistent and can be inflammatory. The antibiotic ciprofloxacin is used to treat EAEC infections, but a full understanding of the antimicrobial effects of ciprofloxacin is needed for more efficient treatment of bacterial infections. In this study, it was found that sub-minimum inhibitory concentrations (sub-MICs) of ciprofloxacin had an inhibitory effect on EAEC adhesion to glass and mammalian HEp-2 cells. It was also observed that bacterial surface properties play an important role in bacterial sensitivity to ciprofloxacin. In an EAEC mutant strain where the hydrophobic positively charged surface protein dispersin was absent, sensitivity to ciprofloxacin was reduced compared with the wild-type strain. Identified here are several antimicrobial effects of ciprofloxacin at sub-MIC concentrations indicating that bacterial surface hydrophobicity affects the response to ciprofloxacin. Investigating the effects of sub-MIC doses of antibiotics on targeted bacteria could help to further our understanding of bacterial pathogenicity and elucidate future antibiotic treatment modalities.

  14. Concentrating Solar Panels: Bringing the Highest Power and Lowest Cost to the Rooftop

    SciTech Connect (OSTI)

    Michael Deck; Rick Russell

    2010-01-05

    Soliant Energy is a venture-capital-backed startup focused on bringing advanced concentrating solar panels to market. Our fundamental innovation is that we are the first company to develop a racking solar concentrator specifically for commercial rooftop applications, resulting in the lowest LCOE for rooftop electricity generation. Today, the commercial rooftop segment is the largest and fastest-growing market in the solar industry. Our concentrating panels can make a major contribution to the SAI's objectives: reducing the cost of solar electricity and rapidly deploying capacity. Our commercialization focus was re-shaped in 2009, shifting from an emphasis solely on panel efficiency to LCOE. Since the inception of the SAI program, LCOE has become the de facto standard for comparing commercial photovoltaic systems. While estimation and prediction models still differ, the emergence of performance-based incentive (PBI) and feed-in tariff (FIT) systems, as well as power purchase agreement (PPA) financing structures make LCOE the natural metric for photovoltaic systems. Soliant Energy has designed and demonstrated lower-cost, higher-power solar panels that consists of 6 (500X) PV module assemblies utilizing multi-junction cells and an integrated two-axis tracker. In addition, we have designed and demonstrated a prototype 1000X panel assembly with 8. Cost reductions relative to conventional flat panel PV systems were realized by (1) reducing the amount of costly semiconductor material and (2) developing strategies and processes to reduce the manufacturing costs of the entire system. Performance gains against conventional benchmarks were realized with (1) two-axis tracking and (2) higher-efficiency multi-junction PV cells capable of operating at a solar concentration ratio of 1000X (1000 kW/m2). The program objectives are: (1) Develop a tracking/concentrating solar module that has the same geometric form factor as a conventional flat, roof mounted photovoltaic (PV) panel - the Soliant module will produce more power and cost less than conventional panels of the same size; (2) Target LCOE: $0.079/kWh in 2010; (3) Target efficiency - 26% in 2010 (22% for 2008 prototype, 24% for 2009 pilot); and (4) Target performance - equivalent to 650Wp in 2010 (490W for 2008 prototype, 540W for 2009 pilot).

  15. Liquid cooled, linear focus solar cell receiver

    DOE Patents [OSTI]

    Kirpich, Aaron S. (Broomall, PA)

    1985-01-01

    Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

  16. Liquid cooled, linear focus solar cell receiver

    DOE Patents [OSTI]

    Kirpich, A.S.

    1983-12-08

    Separate structures for electrical insulation and thermal conduction are established within a liquid cooled, linear focus solar cell receiver for use with parabolic or Fresnel optical concentrators. The receiver includes a V-shaped aluminum extrusion having a pair of outer faces each formed with a channel receiving a string of solar cells in thermal contact with the extrusion. Each cell string is attached to a continuous glass cover secured within the channel with spring clips to isolate the string from the external environment. Repair or replacement of solar cells is effected simply by detaching the spring clips to remove the cover/cell assembly without interrupting circulation of coolant fluid through the receiver. The lower surface of the channel in thermal contact with the cells of the string is anodized to establish a suitable standoff voltage capability between the cells and the extrusion. Primary electrical insulation is provided by a dielectric tape disposed between the coolant tube and extrusion. Adjacent solar cells are soldered to interconnect members designed to accommodate thermal expansion and mismatches. The coolant tube is clamped into the extrusion channel with a releasably attachable clamping strip to facilitate easy removal of the receiver from the coolant circuit.

  17. The role of Förster Resonance Energy Transfer in luminescent solar concentrator efficiency and color tunability

    E-Print Network [OSTI]

    Balaban, Benjamin

    2013-01-01

    IN LUMINESCENT SOLAR CONCENTRATOR EFFICIENCY AND COLORM.A. Baldo, "High-efficiency organic solar concentrators forin luminescent solar concentrator efficiency and color

  18. Phase Change Materials for Thermal Energy Storage in Concentrated Solar Thermal Power Plants

    E-Print Network [OSTI]

    Hardin, Corey Lee

    2011-01-01

    ENERGY STORAGE FOR CONCENTRATING SOLAR POWER PLANTS,”Energy Storage in Concentrated Solar Thermal Power Plants AEnergy Storage in Concentrated Solar Thermal Power Plants by

  19. Phase Change Materials for Thermal Energy Storage in Concentrated Solar Thermal Power Plants

    E-Print Network [OSTI]

    Hardin, Corey Lee

    2011-01-01

    Storage in Concentrated Solar Thermal Power Plants A ThesisStorage in Concentrated Solar Thermal Power Plants by Coreysystems for concentrated solar thermal power (CSP) systems.

  20. Phase Change Materials for Thermal Energy Storage in Concentrated Solar Thermal Power Plants

    E-Print Network [OSTI]

    Hardin, Corey Lee

    2011-01-01

    ENERGY STORAGE FOR CONCENTRATING SOLAR POWER PLANTS,”Thermal Energy Storage in Concentrated Solar Thermal PowerThermal Energy Storage in Concentrated Solar Thermal Power

  1. Final report on LDRD project: A phenomenological model for multicomponent transport with simultaneous electrochemical reactions in concentrated solutions

    SciTech Connect (OSTI)

    CHEN,KEN S.; EVANS,GREGORY H.; LARSON,RICHARD S.; NOBLE,DAVID R.; HOUF,WILLIAM G.

    2000-01-01

    A phenomenological model was developed for multicomponent transport of charged species with simultaneous electrochemical reactions in concentrated solutions, and was applied to model processes in a thermal battery cell. A new general framework was formulated and implemented in GOMA (a multidimensional, multiphysics, finite-element computer code developed and being enhanced at Sandia) for modeling multidimensional, multicomponent transport of neutral and charged species in concentrated solutions. The new framework utilizes the Stefan-Maxwell equations that describe multicomponent diffusion of interacting species using composition-insensitive binary diffusion coefficients. The new GOMA capability for modeling multicomponent transport of neutral species was verified and validated using the model problem of ternary gaseous diffusion in a Stefan tube. The new GOMA-based thermal battery computer model was verified using an idealized battery cell in which concentration gradients are absent; the full model was verified by comparing with that of Bernardi and Newman (1987) and validated using limited thermal battery discharge-performance data from the open literature (Dunning 1981) and from Sandia (Guidotti 1996). Moreover, a new Liquid Chemkin Software Package was developed, which allows the user to handle manly aspects of liquid-phase kinetics, thermodynamics, and transport (particularly in terms of computing properties). Lastly, a Lattice-Boltzmann-based capability was developed for modeling pore- or micro-scale phenomena involving convection, diffusion, and simplified chemistry; this capability was demonstrated by modeling phenomena in the cathode region of a thermal battery cell.

  2. Atmospheric radionuclide concentrations measured by Pacific Northwest Laboratory since 1961

    SciTech Connect (OSTI)

    Young, J.A.; Thomas, C.W.

    1981-03-01

    The atmospheric concentrations of a wide spectrum of radionuclides produced by nuclear weapons, nuclear reactors, cosmic rays, radon and thoron decay and the SNAP-9A burn-up ([sup 238]Pu) have been measured at Richland, Washington, since 1961; at Barrow, Alaska, since 1964; and at other stations for shorter periods of time. There has been considerable concern over the health hazard presented by these radionuclides, but it has also been recognized that atmospheric mixing and deposition rates can be determined from their measurement. Therefore, Pacific Northwest Laboratory began the continuous measurement of the atmospheric concentrations of a wide spectrum of radionuclides produced by nuclear weapons, nuclear reactors, cosmic rays, and radon and thoron decay. This report will discuss the concentrations of the longer-lived radionuclides (T 1/2 > 12 days). The concentrations of shorter-lived radionuclides measured following Chinese nuclear tests since 1972 are discussed in another report.

  3. Atmospheric radionuclide concentrations measured by Pacific Northwest Laboratory since 1961

    SciTech Connect (OSTI)

    Young, J.A.; Thomas, C.W.

    1981-03-01

    The atmospheric concentrations of a wide spectrum of radionuclides produced by nuclear weapons, nuclear reactors, cosmic rays, radon and thoron decay and the SNAP-9A burn-up ({sup 238}Pu) have been measured at Richland, Washington, since 1961; at Barrow, Alaska, since 1964; and at other stations for shorter periods of time. There has been considerable concern over the health hazard presented by these radionuclides, but it has also been recognized that atmospheric mixing and deposition rates can be determined from their measurement. Therefore, Pacific Northwest Laboratory began the continuous measurement of the atmospheric concentrations of a wide spectrum of radionuclides produced by nuclear weapons, nuclear reactors, cosmic rays, and radon and thoron decay. This report will discuss the concentrations of the longer-lived radionuclides (T 1/2 > 12 days). The concentrations of shorter-lived radionuclides measured following Chinese nuclear tests since 1972 are discussed in another report.

  4. SunLab: Advancing Concentrating Solar Power Technology

    SciTech Connect (OSTI)

    1998-11-24

    Concentrating solar power (CSP) technologies, including parabolic troughs, power towers, and dish/engines, have the potential to provide the world with tens of thousands of megawatts of clean, renewable, cost-competitive power.

  5. Matching Interest Points Using Projective Invariant Concentric Circles

    E-Print Network [OSTI]

    Chiu, Han-Pang

    We present a new method to perform reliable matching between different images. This method exploits a projective invariant property between concentric circles and the corresponding projected ellipses to find complete region ...

  6. Secretary Chu Announces up to $62 Million for Concentrating Solar...

    Energy Savers [EERE]

    of low-cost solar technologies we can create new jobs and pave the way towards a clean-energy future." CSP technologies concentrate the sun's energy and capture that energy as...

  7. Journalism Concentration: Grady College MA Thesis Program Planning Form

    E-Print Network [OSTI]

    Arnold, Jonathan

    Journalism Concentration: Grady College MA Thesis Program Planning Form Student and Directed Readings in Mass Communication JRMC 8350 ( ) Special Topics in Journalism JRMC 8025 ( ) Mass Media Law JRMC 8365 ( ) Media Economics JRMC 7355 ( ) Health and Medical Journalism JRMC 7356 ( ) Advanced

  8. Concentration of ozone in surface air over greater Boston

    E-Print Network [OSTI]

    Widen, Donald Allen

    1966-01-01

    Surface ozone concentrations were measured in the Greater Boston area from November, 1964 to December, 1965. Ozone was monitored continuosly using a Mast microcoulombmetric sensor. A chromium trioxide filter was fitted to ...

  9. Thermoelectrics Combined with Solar Concentration for Electrical and Thermal Cogeneration

    E-Print Network [OSTI]

    Jackson, Philip Robert

    2012-01-01

    a heat engine, such as a steam turbine or sterling enginethese concentrations, a steam turbine achieves roughly 25%ratio can run a steam turbine at 35-50% efficiency, with

  10. Nonlinear Pricing Strategies and Market Concentration in the Airline Industry 

    E-Print Network [OSTI]

    Hernandez Garcia, Manuel A.

    2010-10-12

    This dissertation investigates the effect of market concentration on nonlinear pricing strategies in the airline industry. The study develops a theoretical nonlinear pricing model with both discrete product and consumer types to derive testable...

  11. Stabilization of Ion Concentration Polarization Using a Heterogeneous Nanoporous Junction

    E-Print Network [OSTI]

    Kim, Pilnam

    We demonstrate a recycled ion-flux through heterogeneous nanoporous junctions, which induce stable ion concentration polarization with an electric field. The nanoporous junctions are based on integration of ionic hydrogels ...

  12. Material and Chemical Processing (Concentrated Solar) (4 Activities...

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

    information about the student activitylesson plan from your search. Grades 5-8 Subject Solar Summary Concentrated sunlight is a versatile and high-quality form of energy with...

  13. Ultrasonic analyte concentration and application in flow cytometry

    DOE Patents [OSTI]

    Kaduchak, Gregory (Los Alamos, NM); Goddard, Greg (Los Alamos, NM); Salzman, Gary (White Rock, NM); Sinha, Dipen (Los Alamos, NM); Martin, John C. (Los Alamos, NM); Kwiatkowski, Christopher (Los Alamos, NM); Graves, Steven (San Juan Pueblo, NM)

    2008-03-11

    The present invention includes an apparatus and corresponding method for concentrating analytes within a fluid flowing through a tube using acoustic radiation pressure. The apparatus includes a function generator that outputs a radio frequency electrical signal to a transducer that transforms the radio frequency electric signal to an acoustic signal and couples the acoustic signal to the tube. The acoustic signal is converted within the tube to acoustic pressure that concentrates the analytes within the fluid.

  14. Optimal Heat Collection Element Shapes for Parabolic Trough Concentrators

    SciTech Connect (OSTI)

    Bennett, C

    2007-11-15

    For nearly 150 years, the cross section of the heat collection tubes used at the focus of parabolic trough solar concentrators has been circular. This type of tube is obviously simple and easily fabricated, but it is not optimal. It is shown in this article that the optimal shape, assuming a perfect parabolic figure for the concentrating mirror, is instead oblong, and is approximately given by a pair of facing parabolic segments.

  15. Ultrasonic analyte concentration and application in flow cytometry

    DOE Patents [OSTI]

    Kaduchak, Gregory; Goddard, Greg; Salzman, Gary; Sinha, Dipen; Martin, John C.; Kwiatkowski, Christopher; Graves, Steven

    2014-07-22

    The present invention includes an apparatus and corresponding method for concentrating analytes within a fluid flowing through a tube using acoustic radiation pressure. The apparatus includes a function generator that outputs a radio frequency electrical signal to a transducer that transforms the radio frequency electric signal to an acoustic signal and couples the acoustic signal to the tube. The acoustic signal is converted within the tube to acoustic pressure that concentrates the analytes within the fluid.

  16. Ultrasonic analyte concentration and application in flow cytometry

    DOE Patents [OSTI]

    Kaduchak, Gregory; Goddard, Greg; Salzman, Gary; Sinha, Dipen; Martin, John C.; Kwiatkowski, Christopher; Graves, Steven

    2015-07-07

    The present invention includes an apparatus and corresponding method for concentrating analytes within a fluid flowing through a tube using acoustic radiation pressure. The apparatus includes a function generator that outputs a radio frequency electrical signal to a transducer that transforms the radio frequency electric signal to an acoustic signal and couples the acoustic signal to the tube. The acoustic signal is converted within the tube to acoustic pressure that concentrates the analytes within the fluid.

  17. Freeze concentration of dairy products Phase 2. Final report

    SciTech Connect (OSTI)

    Best, D.E.; Vasavada, K.C.

    1993-09-01

    An efficient, electrically driven freeze concentration system offers potential for substantially increasing electricity demand while providing the mature dairy industry with new products for domestic and export markets together with enhanced production efficiencies. Consumer tests indicate that dairy products manufactured from freeze-concentrated ingredients are either preferred or considered equivalent in quality to fresh milk-based products. Economic analyses indicate that this technology should be competitive with thermal evaporation processes on a commercial basis.

  18. Concentrating Solar Power Program Technology Overview (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2001-04-01

    Concentrating solar power systems use the heat from the sun's rays to generate electricity. Reflective surfaces concentrate the sun's rays up to 10,000 times to heat a receiver filled with a heat-exchange fluid, such as oil. The heated fluid is then used to generate electricity in a steam turbine or heat engine. Mechanical drives slowly turn the reflective surfaces during the day to keep the solar radiation focused on the receiver.

  19. Cascade luminescent solar concentrators Sthy Flores Daorta,1

    E-Print Network [OSTI]

    focused on decreasing the cost of PV cells while main- taining or improving their efficiency and redirect it onto small and efficient PV devices, thus reducing the impact of PV cells on the total cost://dx.doi.org/10.1063/1.4871481] In the last few years, we have seen a bourgeoning inter- est in photovoltaic (PV

  20. Efficiency enhancement of luminescent solar concentrations for photovoltaic technologies

    E-Print Network [OSTI]

    Wang, Chunhua

    2011-01-01

    improvement, the device performance is approaching the thermodynamic limit of similar to 28% for single- junction Si solar cells.improvement by PbS near infrared QDs due to the broaden absorption spectrum and near infrared emission properties for PV solar cells.

  1. Threedimensional numerical simulation of the temperature, potential and concentration

    E-Print Network [OSTI]

    Herbin, Raphaèle

    distributions of a unit cell for various geometries of SOFC's Rapha`ele Herbin, Jean­Michel Fiard Universit'e de, SOFC). The physics of fuel cell operation and the simplifying assumptions which are taken into account in the mathematical model are briefly presented in section 2. For a description of the principle of a SOFC, we refer

  2. Adult Stem Cells & Homeostasis

    E-Print Network [OSTI]

    Tian, Weidong

    · Tissue models for studying adult stem cells · Experimental assays · Adult stem cell & Cancer · Adult stem in many organs/tissues · Adult stem cells self-renew and differentiate to maintain tissue homeostasis #12;Stem Cell & Progenitor ·long-term self-renewal ·generate all differentiated cells of an organ

  3. Method for distinguishing normal and transformed cells using G1 kinase inhibitors

    DOE Patents [OSTI]

    Crissman, H.A.; Gadbois, D.M.; Tobey, R.A.; Bradbury, E.M.

    1993-02-09

    A G[sub 1] phase kinase inhibitor is applied in a low concentration to a population of normal and transformed mammalian cells. The concentration of G[sub 1] phase kinase inhibitor is selected to reversibly arrest normal mammalian cells in the G[sub 1] cell cycle without arresting growth of transformed cells. The transformed cells may then be selectively identified and/or cloned for research or diagnostic purposes. The transformed cells may also be selectively killed by therapeutic agents that do not affect normal cells in the G[sub 1] phase, suggesting that such G[sub 1] phase kinase inhibitors may form an effective adjuvant for use with chemotherapeutic agents in cancer therapy for optimizing the killing dose of chemotherapeutic agents while minimizing undesirable side effects on normal cells.

  4. New Multijunction Design Leads to Ultra-Efficient Solar Cell; Highlights in Research & Development, NREL (National Renewable Energy Laboratory)

    SciTech Connect (OSTI)

    2015-09-01

    NREL has demonstrated a 45.7% conversion efficiency for a four-junction solar cell at 234 suns concentration. This achievement represents one of the highest photovoltaic research cell efficiencies ever achieved across all types of solar cells. NREL's new solar cell, which is designed for operation in a concentrator photovoltaic (CPV) system where it can receive more than 1,000 suns of concentrated sunlight, greatly improves earlier designs by adding an additional high quality absorber layer to achieve an ultra-high efficiency.

  5. Atmospheric mercury (Hg) in the Adirondacks: Concentrations and sources

    SciTech Connect (OSTI)

    Hyun-Deok Choi; Thomas M. Holsen; Philip K. Hopke

    2008-08-15

    Hourly averaged gaseous elemental Hg (GEM) concentrations and hourly integrated reactive gaseous Hg (RGM), and particulate Hg (HgP) concentrations in the ambient air were measured at Huntington Forest in the Adirondacks, New York from June 2006 to May 2007. The average concentrations of GEM, RGM, and HgP were 1.4 {+-} 0.4 ng m{sup -3}, 1.8 {+-} 2.2 pg m{sup -3}, and 3.2 {+-} 3.7 pg m{sup -3}, respectively. RGM represents <3.5% of total atmospheric Hg or total gaseous Hg (TGM: GEM + RGM) and HgP represents <3.0% of the total atmospheric Hg. The highest mean concentrations of GEM, RGM, and HgP were measured during winter and summer whereas the lowest mean concentrations were measured during spring and fall. Significant diurnal patterns were apparent in warm seasons for all species whereas diurnal patterns were weak in cold seasons. RGM was better correlated with ozone concentration and temperature in both warm than the other species. Potential source contribution function (PSCF) analysis was applied to identify possible Hg sources. This method identified areas in Pennsylvania, West Virginia, Ohio, Kentucky, Texas, Indiana, and Missouri, which coincided well with sources reported in a 2002 U.S. mercury emissions inventory. 51 refs., 7 figs., 1 tab.

  6. Concentric core optical fiber with multiple-mode signal transmission

    DOE Patents [OSTI]

    Muhs, J.D.

    1997-05-06

    A concentric core optical fiber provides for the simultaneous but independent transmission of signals over a single optical fiber. The concentric optical fiber is constructed of a single-mode or multimode inner optical fiber defined by a core and a cladding of a lower index of refraction than the core and an outer optical fiber defined by additional cladding concentrically disposed around the cladding and of an index of refraction lower than the first mentioned cladding whereby the latter functions as the core of the outer optical fiber. By employing such an optical fiber construction with a single-mode inner core or optical fiber, highly sensitive interferometric and stable less sensitive amplitude based sensors can be placed along the same length of a concentric core optical fiber. Also, by employing the concentric core optical fiber secure telecommunications can be achieved via the inner optical fiber since an intrusion of the concentric optical fiber will first cause a variation in the light being transmitted through the outer optical fiber and this variation of light being used to trigger a suitable alarm indicative of the intrusion. 3 figs.

  7. DOE Fuel Cell Technologies Office: 2013 Fuel Cell Seminar and...

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

    Office: 2013 Fuel Cell Seminar and Energy Exposition DOE Fuel Cell Technologies Office: 2013 Fuel Cell Seminar and Energy Exposition Overview of DOE's Fuel Cell Technologies Office...

  8. Low-Cost High-Concentration Photovoltaic Systems for Utility Power Generation

    SciTech Connect (OSTI)

    McConnell, R.; Garboushian, V.; Gordon, R.; Dutra, D.; Kinsey, G.; Geer, S.; Gomez, H.; Cameron, C.

    2012-03-31

    Under DOE's Technology Pathway Partnership (TPP) program, Amonix, Inc. developed a new generation of high-concentration photovoltaic systems using multijunction technology and established the manufacturing capacity needed to supply multi-megawatt power plants buing using the new Amonix 7700-series solar energy systems. For this effort, Amonix Collaborated with a variety of suppliers and partners to complete project tasks. Subcontractors included: Evonik/Cyro; Hitek; the National Renewable Energy Laboratory (NREL); Raytech; Spectrolab; UL; University of Nevada, Las Vegas; and TUV Rheinland PTL. The Amonix TPP tasks included: Task 1: Multijunction Cell Optimization for Field Operation, Task 2: Fresnel Lens R&D, Task 3: Cell Package Design & Production, Task 4: Standards Compliance and Reliability Testing, Task 5: Receiver Plate Production, Task 6: MegaModule Performance, Task 7: MegaModule Cost Reduction, Task 8: Factory Setup and MegaModule Production, Task 9: Tracker and Tracking Controller, Task 10: Installation and Balance of System (BOS), Task 11: Field Testing, and Task 12: Solar Advisor Modeling and Market Analysis. Amonix's TPP addressed nearly the complete PV value chain from epitaxial layer design and wafer processing through system design, manufacturing, deployment and O&M. Amonix has made progress toward achieving these reduced costs through the development of its 28%+ efficient MegaModule, reduced manufacturing and installation cost through design for manufacturing and assembly, automated manufacturing processes, and reduced O&M costs. Program highlights include: (1) Optimized multijunction cell and cell package design to improve performance by > 10%; (2) Updated lens design provided 7% increased performance and higher concentration; (3) 28.7% DC STC MegaModule efficiency achieved in Phase II exceeded Phase III performance goal; (4) New 16' focal length MegaModule achieved target materials and manufacturing cost reduction; (5) Designed and placed into production 25 MW/yr manufacturing capacity for complete MegaModules, including cell packages, receiver plates, and structures with lenses; (6) Designed and deployed Amonix 7700 series systems rated at 63 kW PTC ac and higher. Based on an LCOE assessment using NREL's Solar Advisor Model, Amonix met DOE's LCOE targets: Amonix 2011 LCOE 12.8 cents/kWh (2010 DOE goal 10-15); 2015 LCOE 6.4 cents/kWh (2015 goal 5-7) Amonix and TPP participants would like to thank the U.S. Department of Energy Solar Energy Technology Program for funding received under this program through Agreement No. DE-FC36-07GO17042.

  9. Micro-optics for high-efficiency optical performance and simplified tracking for concentrated photovoltaics (CPV).

    SciTech Connect (OSTI)

    Sinclair, Michael B.; Filatov, Anton; Lentine, Anthony L.; Sweatt, William C.; Nielson, Gregory N.; Okandan, Murat; Jared, Bradley Howell

    2010-02-01

    Micro-optical 5mm lenses in 50mm sub-arrays illuminate arrays of photovoltaic cells with 49X concentration. Fine tracking over {+-}10{sup o} FOV in sub-array allows coarse tracking by meter-sized solar panels. Plastic prototype demonstrated for 400nm < {lambda} < 1600 nm. We have designed a solar collector that will be composed of 50-mm-diameter sub-arrays, each containing {approx}100 5-mm plastic micro-lenses. Each micro-lens illuminates a stack of about four 0.7mm PV cells that collect sunlight from 400nm to 1600 nm with a theoretical efficiency approaching 50%. Each sub-array has internal solar tracking and alignment over a {+-}10{sup o} field, so a large array of sub-arrays only needs to coarsely track the sun. The refractive lenses in the design are thin so the optical transmission can be >90% and the optics will weigh very little. There are other optical properties incorporated in this design that help the photovoltaic cells to operate very efficiently. We are building a pre-prototype system now, and will describe our progress at the conference.

  10. Fig. S1. Current efficiency of electromethanogenesis. Electron equivalents needed for the2 formation of the measured concentrations of CH4 or H2 (from CO2 or water, respectively) and3

    E-Print Network [OSTI]

    culture and grown at 37C in an shaking water bath. Cells were harvested in early stationary35 phase formation of the measured concentrations of CH4 or H2 (from CO2 or water, respectively) and3 electrons. thermolithotrophicus cells were cultured in a modified DSMZ mineral medium 141, omitting18 Na-acetate, yeast extract

  11. The Strategy & Leadership concentration prepares students to step into strategic management and organizational leadership positions. The concentration offers two

    E-Print Network [OSTI]

    The Strategy & Leadership concentration prepares students to step into strategic management Strategy; Mergers, Acquisitions, and Alliances; Strategic Management of Innovation and Technology and services to cope with technological and market changes, manage mergers, acquisitions and alliances

  12. Tubular solid oxide fuel cell current collector

    DOE Patents [OSTI]

    Bischoff, Brian L. (Knoxville, TN); Sutton, Theodore G. (Kingston, TN); Armstrong, Timothy R. (Clinton, TN)

    2010-07-20

    An internal current collector for use inside a tubular solid oxide fuel cell (TSOFC) electrode comprises a tubular coil spring disposed concentrically within a TSOFC electrode and in firm uniform tangential electrical contact with the electrode inner surface. The current collector maximizes the contact area between the current collector and the electrode. The current collector is made of a metal that is electrically conductive and able to survive under the operational conditions of the fuel cell, i.e., the cathode in air, and the anode in fuel such as hydrogen, CO, CO.sub.2, H.sub.2O or H.sub.2S.

  13. Fuel cell-fuel cell hybrid system

    DOE Patents [OSTI]

    Geisbrecht, Rodney A.; Williams, Mark C.

    2003-09-23

    A device for converting chemical energy to electricity is provided, the device comprising a high temperature fuel cell with the ability for partially oxidizing and completely reforming fuel, and a low temperature fuel cell juxtaposed to said high temperature fuel cell so as to utilize remaining reformed fuel from the high temperature fuel cell. Also provided is a method for producing electricity comprising directing fuel to a first fuel cell, completely oxidizing a first portion of the fuel and partially oxidizing a second portion of the fuel, directing the second fuel portion to a second fuel cell, allowing the first fuel cell to utilize the first portion of the fuel to produce electricity; and allowing the second fuel cell to utilize the second portion of the fuel to produce electricity.

  14. Thermal Management of Solar Cells

    E-Print Network [OSTI]

    Saadah, Mohammed Ahmed

    2013-01-01

    cell. The solar cell’s power conversion efficiency, ? is theEfficiency ..5 Thermal Managements of SolarTemperature on Efficiency Photons incident on a solar cell

  15. Thermal Management of Solar Cells

    E-Print Network [OSTI]

    Saadah, Mohammed Ahmed

    2013-01-01

    D. Mills, "Cooling of photovoltaic cells under concentratedelectric performance of a photovoltaic cells by cooling andof Photovoltaic Solar Cell A photovoltaic cell is a

  16. Nanocrystal Solar Cells

    E-Print Network [OSTI]

    Gur, Ilan

    2006-01-01

    basic bilayer CdTe/CdSe solar cells described above. Figurecomplete CdTe/CdSe nanocrystal solar cell (B). gap variationlength for CdSe-P3HT hybrid solar cells. (b) Current-voltage

  17. Nanocrystal Solar Cells

    E-Print Network [OSTI]

    Gur, Ilan

    2006-01-01

    of organic based solar cells and distinguish them from theirNov, 2005). Chapter 4 Hybrid solar cells with 3-dimensionalinorganic nanocrystal solar cells 5.1 Introduction In recent

  18. Nanocrystal Solar Cells

    E-Print Network [OSTI]

    Gur, Ilan

    2006-01-01

    inorganic nanocrystal solar cells 5.1 Introduction In recentoperation of organic based solar cells and distinguish themThe organic donor-acceptor solar cell relies on a type II

  19. Nanocrystal Solar Cells

    E-Print Network [OSTI]

    Gur, Ilan

    2006-01-01

    of organic based solar cells and distinguish them from theirinorganic nanocrystal solar cells 5.1 Introduction In recentNov, 2005). Chapter 4 Hybrid solar cells with 3-dimensional

  20. Nanocrystal Solar Cells

    E-Print Network [OSTI]

    Gur, Ilan

    2006-01-01

    Nov, 2005). Chapter 4 Hybrid solar cells with 3-dimensional5 All-inorganic nanocrystal solar cells 5.1 Introduction Inoperation of organic based solar cells and distinguish them