Science.gov

Sample records for liquid energy carriers

  1. 46 CFR 111.105-29 - Combustible liquid cargo carriers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Combustible liquid cargo carriers. 111.105-29 Section... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-29 Combustible liquid cargo carriers. (a) Each vessel that carries combustible liquid cargo with a closed-cup flashpoint of 60 degrees...

  2. 46 CFR 111.105-29 - Combustible liquid cargo carriers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Combustible liquid cargo carriers. 111.105-29 Section... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-29 Combustible liquid cargo carriers. (a) Each vessel that carries combustible liquid cargo with a closed-cup flashpoint of 60 degrees...

  3. 46 CFR 111.105-29 - Combustible liquid cargo carriers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Combustible liquid cargo carriers. 111.105-29 Section... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-29 Combustible liquid cargo carriers. (a) Each vessel that carries combustible liquid cargo with a closed-cup flashpoint of 60 degrees...

  4. 46 CFR 111.105-29 - Combustible liquid cargo carriers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Combustible liquid cargo carriers. 111.105-29 Section... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-29 Combustible liquid cargo carriers. (a) Each vessel that carries combustible liquid cargo with a closed-cup flashpoint of 60 degrees...

  5. 46 CFR 111.105-29 - Combustible liquid cargo carriers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Combustible liquid cargo carriers. 111.105-29 Section... ELECTRIC SYSTEMS-GENERAL REQUIREMENTS Hazardous Locations § 111.105-29 Combustible liquid cargo carriers. (a) Each vessel that carries combustible liquid cargo with a closed-cup flashpoint of 60 degrees...

  6. Energy and its carriers

    NASA Astrophysics Data System (ADS)

    Schmid, G. Bruno

    1982-09-01

    Reports on the first course of a new physics curriculum developed at the Karlsruhe Institute for the Didactics of Physics (Falk and Herrmann 1977, 1978, 1979, 1981). The entire curriculum begins at the elementary school level with children aged 10-12 and is intended to extend beyond high school and through university studies (Falk and Ruppel 1975, 1976). Energy is introduced as the primary quantity at the very beginning of the course. It is not 'derived' from other seemingly more fundamental quantities such as mass, displacement, velocity and force. However, the course is not an ad hoc construction simply to explain the concept of energy. The essential features of many natural and technological processes can be understood by considering the flow of energy. This is the basic idea underlying the course, and can be restated more completely in terms of the following rule: 'something is happening whenever energy is flowing and a flow of energy is always accompanied by the flow of at least one other substance-like quantity'. The course strategy is designed to make this simple rule obvious by way of numerous examples taken from everyday life. Selected topics are highlighted and they introduce concepts unique to the authors approach. These concepts are presented in the same chronological order as they appear in the course.

  7. Energy and Its Carriers.

    ERIC Educational Resources Information Center

    Schmid, G. Bruno

    1982-01-01

    Describes the first course of a new physics curriculum developed at the Karlsruke Institute for the Didactics of Physics. The basic idea, energy flow, is introduced at the beginning of the course and illustrated by examples from everyday life. Highlights selected topics which introduce concepts unique to the approach. (Author/JN)

  8. Hydrogen: the future energy carrier.

    PubMed

    Züttel, Andreas; Remhof, Arndt; Borgschulte, Andreas; Friedrichs, Oliver

    2010-07-28

    Since the beginning of the twenty-first century the limitations of the fossil age with regard to the continuing growth of energy demand, the peaking mining rate of oil, the growing impact of CO2 emissions on the environment and the dependency of the economy in the industrialized world on the availability of fossil fuels became very obvious. A major change in the energy economy from fossil energy carriers to renewable energy fluxes is necessary. The main challenge is to efficiently convert renewable energy into electricity and the storage of electricity or the production of a synthetic fuel. Hydrogen is produced from water by electricity through an electrolyser. The storage of hydrogen in its molecular or atomic form is a materials challenge. Some hydrides are known to exhibit a hydrogen density comparable to oil; however, these hydrides require a sophisticated storage system. The system energy density is significantly smaller than the energy density of fossil fuels. An interesting alternative to the direct storage of hydrogen are synthetic hydrocarbons produced from hydrogen and CO2 extracted from the atmosphere. They are CO2 neutral and stored like fossil fuels. Conventional combustion engines and turbines can be used in order to convert the stored energy into work and heat. PMID:20566514

  9. Research on energy efficiency design index for sea-going LNG carriers

    NASA Astrophysics Data System (ADS)

    Lin, Yan; Yu, Yanyun; Guan, Guan

    2014-12-01

    This paper describes the characteristics of liquefied natural gas (LNG) carriers briefly. The LNG carrier includes power plant selection, vapor treatment, liquid cargo tank type, etc. Two parameters—fuel substitution rate and recovery of boil of gas (BOG) volume to energy efficiency design index (EEDI) formula are added, and EEDI formula of LNG carriers is established based on ship EEDI formula. Then, based on steam turbine propulsion device of LNG carriers, mathematical models of LNG carriers' reference line value are established in this paper. By verification, the EEDI formula of LNG carriers described in this paper can provide a reference for LNG carrier EEDI calculation and green shipbuilding.

  10. Carrier density independent scattering rate in SrTiO3-based electron liquids

    NASA Astrophysics Data System (ADS)

    Mikheev, Evgeny; Raghavan, Santosh; Zhang, Jack Y.; Marshall, Patrick B.; Kajdos, Adam P.; Balents, Leon; Stemmer, Susanne

    2016-02-01

    We examine the carrier density dependence of the scattering rate in two- and three-dimensional electron liquids in SrTiO3 in the regime where it scales with Tn (T is the temperature and n ≤ 2) in the cases when it is varied by electrostatic control and chemical doping, respectively. It is shown that the scattering rate is independent of the carrier density. This is contrary to the expectations from Landau Fermi liquid theory, where the scattering rate scales inversely with the Fermi energy (EF). We discuss that the behavior is very similar to systems traditionally identified as non-Fermi liquids (n < 2). This includes the cuprates and other transition metal oxide perovskites, where strikingly similar density-independent scattering rates have been observed. The results indicate that the applicability of Fermi liquid theory should be questioned for a much broader range of correlated materials and point to the need for a unified theory.

  11. Ionic liquids as potential carriers of low viscosity magnetorheological fluids

    NASA Astrophysics Data System (ADS)

    Guerrero-Sanchez, Carlos; Ortiz-Alvarado, Armando; Schubert, Ulrich S.

    2009-03-01

    Based on the latest investigations on the formulation of new magneto-rheological fluids, it is envisioned that the use of ionic liquids as carriers of magneto-rheological fluids will open new possibilities of applications for these smart fluids due to the fact that their physical and chemical properties can be fine-tuned in a broad range. This contribution addresses one potentially important advantage of magneto-rheological fluids which use ionic liquids as novel carriers. In connection with this, magneto-rheological fluids with a low viscosity in the off-state without compromising other properties of the formulations (e. g., sedimentation of the dispersed magnetic particles, liquid state of the carriers in a broad range of temperatures) are often required for specific applications. In this regard, ionic liquids of low viscosity can be very useful in the development of such magneto-rheological fluids. Thus, this contribution reports on the magnetorheological properties of iron(II, III) oxide particles dispersed in the ionic liquid 1-ethyl-3-methylimidazolium thiocyanate (a low viscosity ionic liquid) in the temperature range from 20 °C to 80 °C. The experimental results have revealed that the apparent viscosity of the dispersion slightly changes with the temperature when a constant magnetic field is applied and its value mainly depends on the shear rate and the strength of the magnetic field. The viscosity of the dispersion remains practically unmodified with both the temperature and the magnetic field intensity as the magnetic saturation of the material is reached; in this regime the viscosity will only depend on the applied shear rate. In contrast, the yield stress values of the dispersion as well as the corresponding shear stress vs. shear rate curves have shown an inverse behavior with temperature for a constant magnetic field.

  12. A novel liquid organic hydrogen carrier system based on catalytic peptide formation and hydrogenation

    PubMed Central

    Hu, Peng; Fogler, Eran; Diskin-Posner, Yael; Iron, Mark A.; Milstein, David

    2015-01-01

    Hydrogen is an efficient green fuel, but its low energy density when stored under high pressure or cryogenically, and safety issues, presents significant disadvantages; hence finding efficient and safe hydrogen carriers is a major challenge. Of special interest are liquid organic hydrogen carriers (LOHCs), which can be readily loaded and unloaded with considerable amounts of hydrogen. However, disadvantages include high hydrogen pressure requirements, high reaction temperatures for both hydrogenation and dehydrogenation steps, which require different catalysts, and high LOHC cost. Here we present a readily reversible LOHC system based on catalytic peptide formation and hydrogenation, using an inexpensive, safe and abundant organic compound with high potential capacity to store and release hydrogen, applying the same catalyst for loading and unloading hydrogen under relatively mild conditions. Mechanistic insight of the catalytic reaction is provided. We believe that these findings may lead to the development of an inexpensive, safe and clean liquid hydrogen carrier system. PMID:25882348

  13. Evaluation of industrially applied heat-transfer fluids as liquid organic hydrogen carrier systems.

    PubMed

    Brückner, Nicole; Obesser, Katharina; Bösmann, Andreas; Teichmann, Daniel; Arlt, Wolfgang; Dungs, Jennifer; Wasserscheid, Peter

    2014-01-01

    Liquid organic hydrogen carrier (LOHC) systems offer a very attractive method for the decentralized storage of renewable excess energy. In this contribution, industrially well-established heat-transfer oils (typically sold under trade names, e.g., Marlotherm) are proposed as a new class of LOHC systems. It is demonstrated that the liquid mixture of isomeric dibenzyltoluenes (m.p. -39 to -34 °C, b.p. 390 °C) can be readily hydrogenated to the corresponding mixture of perhydrogenated analogues by binding 6.2 wt% of H2. The liquid H2 -rich form can be stored and transported similarly to diesel fuel. It readily undergoes catalytic dehydrogenation at temperatures above 260 °C, which proves its applicability as a reversible H2 carrier. The presented LOHC systems are further characterized by their excellent technical availability at comparably low prices, full registration of the H2 -lean forms, and excellent thermal stabilities. PMID:23956191

  14. Novel macrocyclic carriers for proton-coupled liquid membrane transport

    SciTech Connect

    Lamb, J.D.

    1991-06-10

    The objective of our research program is to elucidate the chemical principles which are responsible for the cation selectivity and permeability of liquid membranes containing macrocyclic carriers. Several new macrocyclic carriers were synthesized during the last three year period, including selenium-containing macrocycles, new crown-4 structures, and several new crown structures containing nitrogen based heterocycles as substituents in the principal macrocyclic ring. The cation binding properties of these macrocycles were investigated by potentiometric titration, calorimetric titration, solvent extraction, and NMR techniques. In addition, hydrophobic macrocycles were incorporated into dual hollow fiber membrane systems to investigate their membrane performance, especially in the proton-coupled transport mode. It was found that the dual hollow fiber system maintains the cation selectivity and permeability of supported liquid membranes, while enhancing membrane stability. The diffusion limited transport model was expanded to account for membrane solvent effects. Furthermore, Eu{sup 2+} transport was found to be similar to that of strontium and much higher than that of the lanthanides, in supported liquid membrane systems.

  15. Carrier density independent scattering rate in SrTiO3-based electron liquids

    PubMed Central

    Mikheev, Evgeny; Raghavan, Santosh; Zhang, Jack Y.; Marshall, Patrick B.; Kajdos, Adam P.; Balents, Leon; Stemmer, Susanne

    2016-01-01

    We examine the carrier density dependence of the scattering rate in two- and three-dimensional electron liquids in SrTiO3 in the regime where it scales with Tn (T is the temperature and n ≤ 2) in the cases when it is varied by electrostatic control and chemical doping, respectively. It is shown that the scattering rate is independent of the carrier density. This is contrary to the expectations from Landau Fermi liquid theory, where the scattering rate scales inversely with the Fermi energy (EF). We discuss that the behavior is very similar to systems traditionally identified as non-Fermi liquids (n < 2). This includes the cuprates and other transition metal oxide perovskites, where strikingly similar density-independent scattering rates have been observed. The results indicate that the applicability of Fermi liquid theory should be questioned for a much broader range of correlated materials and point to the need for a unified theory. PMID:26861764

  16. Carrier density independent scattering rate in SrTiO₃-based electron liquids

    DOE PAGESBeta

    Mikheev, Evgeny; Raghavan, Santosh; Zhang, Jack Y.; Marshall, Patrick B.; Kajdos, Adam P.; Balents, Leon; Stemmer, Susanne

    2016-02-10

    We examine the carrier density dependence of the scattering rate in two- and three-dimensional electron liquids in SrTiO3 in the regime where it scales with Tn (T is the temperature and n ≤ 2) in the cases when it is varied by electrostatic control and chemical doping, respectively. It is shown that the scattering rate is independent of the carrier density. This is contrary to the expectations from Landau Fermi liquid theory, where the scattering rate scales inversely with the Fermi energy (EF). We discuss that the behavior is very similar to systems traditionally identified as non-Fermi liquids (n liquid theory should be questioned for a much broader range of correlated materials and point to the need for a unified theory.« less

  17. Hydrogen - Energy carrier of the future

    NASA Astrophysics Data System (ADS)

    Nitsch, Joachim; Steeb, Hartmut

    1986-11-01

    The potential of hydrogen as an energy carrier - in conventional burners, in internal-combustion or turbine engines, in fuel cells, in catalytic burners, or in steam generators - is discussed, and the current status of the Hysolar program is reviewed. Hysolar is a cooperative project of the University of Stuttgart, DFVLR, and Saudi Arabia to develop industrial-scale hydrogen-production facilities employing solar-cell arrays and electrolysis. Hysolar calls for basic research in photoelectrochemistry, electrolysis, and fuel-cell technology; studies of hydrogen production systems and application technology; training of personnel; and construction of a 2-kW laboratory installation at Jiddah, a 10-kW experimental installation at Stuttgart, and a 100-kW demonstration installation at Riad (producing about 44,000 N cu m of hydrogen per year). Diagrams, drawings, and tables are provided.

  18. Carrier transport simulation of anomalous temperature dependence in nematic liquid crystals.

    PubMed

    Goto, Masanao; Takezoe, Hideo; Ishikawa, Ken

    2007-10-01

    We investigated the carrier transport phenomena in model liquid crystalline systems, which were constructed on the basis of the Gay-Berne potential and Monte Carlo calculation. The carrier transport was analyzed under the condition that the molecular arrangement in the system was fixed and thermally activated carriers were transported by hopping in the system. The carrier transport simulation was performed by Monte Carlo method using Miller-Abrahams hopping ratio. By these calculations, we reproduced the experimental results of the electronic conduction in nematic liquid crystals. PMID:17994925

  19. Carrier transport simulation of anomalous temperature dependence in nematic liquid crystals

    NASA Astrophysics Data System (ADS)

    Goto, Masanao; Takezoe, Hideo; Ishikawa, Ken

    2007-10-01

    We investigated the carrier transport phenomena in model liquid crystalline systems, which were constructed on the basis of the Gay-Berne potential and Monte Carlo calculation. The carrier transport was analyzed under the condition that the molecular arrangement in the system was fixed and thermally activated carriers were transported by hopping in the system. The carrier transport simulation was performed by Monte Carlo method using Miller-Abrahams hopping ratio. By these calculations, we reproduced the experimental results of the electronic conduction in nematic liquid crystals.

  20. Heat to electricity conversion by cold carrier emissive energy harvesters

    NASA Astrophysics Data System (ADS)

    Strandberg, Rune

    2015-12-01

    This paper suggests a method to convert heat to electricity by the use of devices called cold carrier emissive energy harvesters (cold carrier EEHs). The working principle of such converters is explained and theoretical power densities and efficiencies are calculated for ideal devices. Cold carrier EEHs are based on the same device structure as hot carrier solar cells, but works in an opposite way. Whereas a hot carrier solar cell receives net radiation from the sun and converts some of this radiative heat flow into electricity, a cold carrier EEH sustains a net outflux of radiation to the surroundings while converting some of the energy supplied to it into electricity. It is shown that the most basic type of cold carrier EEHs have the same theoretical efficiency as the ideal emissive energy harvesters described earlier by Byrnes et al. In the present work, it is also shown that if the emission from the cold carrier EEH originates from electron transitions across an energy gap where a difference in the chemical potential of the electrons above and below the energy gap is sustained, power densities slightly higher than those given by Byrnes et al. can be achieved.

  1. Heat to electricity conversion by cold carrier emissive energy harvesters

    SciTech Connect

    Strandberg, Rune

    2015-12-07

    This paper suggests a method to convert heat to electricity by the use of devices called cold carrier emissive energy harvesters (cold carrier EEHs). The working principle of such converters is explained and theoretical power densities and efficiencies are calculated for ideal devices. Cold carrier EEHs are based on the same device structure as hot carrier solar cells, but works in an opposite way. Whereas a hot carrier solar cell receives net radiation from the sun and converts some of this radiative heat flow into electricity, a cold carrier EEH sustains a net outflux of radiation to the surroundings while converting some of the energy supplied to it into electricity. It is shown that the most basic type of cold carrier EEHs have the same theoretical efficiency as the ideal emissive energy harvesters described earlier by Byrnes et al. In the present work, it is also shown that if the emission from the cold carrier EEH originates from electron transitions across an energy gap where a difference in the chemical potential of the electrons above and below the energy gap is sustained, power densities slightly higher than those given by Byrnes et al. can be achieved.

  2. Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers.

    PubMed

    Blumenschein, Nicholas; Han, Daewoo; Steckl, Andrew J

    2015-01-01

    Magnetic beads with ~1.9 µm average diameter were used to transport microliter volumes of liquids between contiguous liquid segments with a tube for the purpose of investigating phase change of those liquid segments. The magnetic beads were externally controlled using a magnet, allowing for the beads to bridge the air valve between the adjacent liquid segments. A hydrophobic coating was applied to the inner surface of the tube to enhance the separation between two liquid segments. The applied magnetic field formed an aggregate cluster of magnetic beads, capturing a certain liquid amount within the cluster that is referred to as carry-over volume. A fluorescent dye was added to one liquid segment, followed by a series of liquid transfers, which then changed the fluorescence intensity in the neighboring liquid segment. Based on the numerical analysis of the measured fluorescence intensity change, the carry-over volume per mass of magnetic beads has been found to be ~2 to 3 µl/mg. This small amount of liquid allowed for the use of comparatively small liquid segments of a couple hundred microliters, enhancing the feasibility of the device for a lab-in-tube approach. This technique of applying small compositional variation in a liquid volume was applied to analyzing the binary phase diagram between water and the surfactant C12E5 (pentaethylene glycol monododecyl ether), leading to quicker analysis with smaller sample volumes than conventional methods. PMID:26381055

  3. Process for hydrocracking carbonaceous material in liquid carrier

    DOEpatents

    Duncan, Dennis A.

    1980-01-01

    Solid carbonaceous material is hydrocracked to provide aliphatic and aromatic hydrocarbons for use as gaseous and liquid fuels or chemical feed stock. Particulate carbonaceous material such as coal in slurry with recycled product oil is preheated in liquid state to a temperature of 600.degree.-1200.degree. F. in the presence of hydrogen gas. The product oil acts as a sorbing agent for the agglomerating bitumins to minimize caking within the process. In the hydrocracking reactor, the slurry of oil and carbonaceous particles is heated within a tubular passageway to vaporize the oil and form a gas-solid mixture which is further heated to a hydropyrolysis temperature in excess of 1200.degree. F. The gas-solid mixture is quenched by contact with additional oil to condense normally liquid hydrocarbons for separation from the gases. A fraction of the hydrocarbon liquid product is recycled for quenching and slurrying with the carbonaceous feed. Hydrogen is recovered from the gas for recycle and additional hydrogen is produced by gasification of residual char.

  4. Carriers

    MedlinePlus

    ... for those known to be at risk for genetic diseases. Reproductive Choices For couples who are carriers, reproductive decisions can be sensitive. A number of options are available, such as adoption, prenatal testing, and pre-implantation genetic diagnosis (PGD). PGD screens ...

  5. Carrier transport simulation in a model liquid crystalline system with the biaxial Gay-Berne potential.

    PubMed

    Goto, Masanao; Takezoe, Hideo; Ishikawa, Ken

    2010-02-01

    In this paper, we performed carrier transport simulation to understand the unusual temperature dependence of the carrier mobility observed in nematic liquid crystals. For this purpose, we made a model liquid crystalline system consisting of biaxial Gay-Berne particles, and then we simulated hopping transport between these particles. The hopping rate was formulated suitably for the biaxial Gay-Berne particles based on the investigation of the electronic overlaps between actual aromatic molecules. The carrier transport simulation was performed by master equation method on the model system prepared by N-P-T ensemble Monte Carlo simulation. We reproduced gradual mobility increase in the nematic phase as a result of the change in the short range molecular order. PMID:20136321

  6. Carrier transport simulation in a model liquid crystalline system with the biaxial Gay-Berne potential

    NASA Astrophysics Data System (ADS)

    Goto, Masanao; Takezoe, Hideo; Ishikawa, Ken

    2010-02-01

    In this paper, we performed carrier transport simulation to understand the unusual temperature dependence of the carrier mobility observed in nematic liquid crystals. For this purpose, we made a model liquid crystalline system consisting of biaxial Gay-Berne particles, and then we simulated hopping transport between these particles. The hopping rate was formulated suitably for the biaxial Gay-Berne particles based on the investigation of the electronic overlaps between actual aromatic molecules. The carrier transport simulation was performed by master equation method on the model system prepared by N-P-T ensemble Monte Carlo simulation. We reproduced gradual mobility increase in the nematic phase as a result of the change in the short range molecular order.

  7. Apparatus and methods of measuring minority carrier lifetime using a liquid probe

    DOEpatents

    Li, Jian

    2016-04-12

    Methods and apparatus for measuring minority carrier lifetimes using liquid probes are provided. In one embodiment, a method of measuring the minority carrier lifetime of a semiconductor material comprises: providing a semiconductor material having a surface; forming a rectifying junction at a first location on the surface by temporarily contacting the surface with a conductive liquid probe; electrically coupling a second junction to the semiconductor material at a second location, wherein the first location and the second location are physically separated; applying a forward bias to the rectifying junction causing minority carrier injection in the semiconductor material; measuring a total capacitance as a function of frequency between the rectifying junction and the second junction; determining an inflection frequency of the total capacitance; and determining a minority lifetime of the semiconductor material from the inflection frequency.

  8. Thermoradiation processes of energy-carrier production

    NASA Astrophysics Data System (ADS)

    Dzantiev, B. G.; Ermakov, A. N.; Zhitomirskii, V. M.; Popov, V. N.

    Thermoradiation processes in the production of hydrogen and carbon monoxide from water vapor and CO2 are discussed. An radiolysis experiment was conducted using a one-pass flow system and an electron accelerator (with energy of 3 Me V), according to parameters of dose rate, regent-radiation contact time, and temperature (700 deg). Steady-state concentrations of H2 and CO were found to correspond to 20 and 40 percent radiation energy-product and energy conversion, respectively. The results of the experiment permit an accurate determination of the optimal parameters of the conversion process and an estimate of the relative efficiencies of chemonuclear and electrochemical methods (plasmolysis and electrolysis) of H2 and CO production using nuclear piles.

  9. Hydrogen: The Ultimate Fuel and Energy Carrier.

    ERIC Educational Resources Information Center

    Dinga, Gustav P.

    1988-01-01

    Lists 24 frequently asked questions concerning hydrogen as a fuel with several responses given to each question. Emphasized are hydrogen production, storage, transmission, and application to various energy-consuming sectors. Summarizes current findings and research on hydrogen. An extensive bibliography is included. (ML)

  10. [Effects of carrier liquid and flow rate on the separation in gravitational field-flow fractionation].

    PubMed

    Guo, Shuang; Zhu, Chenqi; Gao-Yang, Yaya; Qiu, Bailing; Wu, Di; Liang, Qihui; He, Jiayuan; Han, Nanyin

    2016-02-01

    Gravitational field-flow fractionation is the simplest field-flow fractionation technique in terms of principle and operation. The earth' s gravity is its external field. Different sized particles are injected into a thin channel and carried by carrier fluid. The different velocities of the carrier liquid in different places results in a size-based separation. A gravitational field-flow fractionation (GrFFF) instrument was designed and constructed. Two kinds of polystyrene (PS) particles with different sizes (20 µm and 6 µm) were chosen as model particles. In this work, the separation of the sample was achieved by changing the concentration of NaN3, the percentage of mixed surfactant in the carrier liquid and the flow rate of carrier liquid. Six levels were set for each factor. The effects of these three factors on the retention ratio (R) and plate height (H) of the PS particles were investigated. It was found that R increased and H decreased with increasing particle size. On the other hand, the R and H increased with increasing flow rate. The R and H also increased with increasing NaN3 concentration. The reason was that the electrostatic repulsive force between the particles and the glass channel wall increased. The force allowed the samples approach closer to the channel wall. The results showed that the resolution and retention time can be improved by adjusting the experimental conditions. These results can provide important values to the further applications of GrFFF technique. PMID:27382718

  11. Localization of carriers in a one-dimensional electron system over liquid helium

    NASA Astrophysics Data System (ADS)

    Gladchenko, S. P.; Kovdrya, Yu. Z.; Nikolaenko, V. A.

    2000-07-01

    The mobility of carriers in a one-dimensional electron system over liquid helium has been measured at the temperature 0.5-1.7 K and for different values of linear electron density. Profiled nylon substrates with some quantity of charge deposited were used for the realization of a one-dimensional electron system. It is shown that electron mobility is dependent on the quantity of the charge on a substrate. Effects observed are explained by the localization of electrons moving in the random potential created by the substrates charge. It is supposed that at low temperatures the movement of carriers is determined by quantum effects.

  12. Technical Assessment of Organic Liquid Carrier Hydrogen Storage Systems for Automotive Applications

    SciTech Connect

    Ahluwalia, R. K.; Hua, T. Q.; Peng, J. -K; Kromer, M.; Lasher, S.; McKenney, K.; Law, K.; Sinha, J.

    2011-06-21

    In 2007-2009, the DOE Hydrogen Program conducted a technical assessment of organic liquid carrier based hydrogen storage systems for automotive applications, consistent with the Program’s Multiyear Research, Development, and Demonstration Plan. This joint performance (ANL) and cost analysis (TIAX) report summarizes the results of this assessment. These results should be considered only in conjunction with the assumptions used in selecting, evaluating, and costing the systems discussed here and in the Appendices.

  13. Vacuum Surface Science Meets Heterogeneous Catalysis: Dehydrogenation of a Liquid Organic Hydrogen Carrier in the Liquid State.

    PubMed

    Matsuda, Takashi; Taccardi, Nicola; Schwegler, Johannes; Wasserscheid, Peter; Steinrück, Hans-Peter; Maier, Florian

    2015-06-22

    Ultrahigh vacuum (UHV) surface science techniques are used to study the heterogeneous catalytic dehydrogenation of a liquid organic hydrogen carrier in its liquid state close to the conditions of real catalysis. For this purpose, perhydrocarbazole (PH), otherwise volatile under UHV, is covalently linked as functional group to an imidazolium cation, forming a non-volatile ionic liquid (IL). The catalysed dehydrogenation of the PH unit as a function of temperature is investigated for a Pt foil covered by a macroscopically thick PH-IL film and for Pd particles suspended in the PH-IL film, and for PH-IL on Au as inert support. X-ray photoelectron spectroscopy and thermal desorption spectroscopy allows us to follow in situ the catalysed transition of perhydrocarbazole to carbazole at technical reaction temperatures. The data demonstrate the crucial role of the Pt and Pd catalysts in order to shift the dehydrogenation temperature below the critical temperature of thermal decomposition. PMID:25891821

  14. US Department of Energy motor carrier evaluation program

    SciTech Connect

    Savage, T.C.; Lopez, C.A.; Blalock, L.B.

    1996-12-31

    The Department of Energy (DOE) has taken a positive step in ensuring that carriers are highly qualified before they are permitted to transport any DOE material classified as hazardous in Title 49 CFR. The process utilized by the DOE is the Motor Carrier Evaluation Program (MCEP). The MCEP is considered to be a cornerstone for building a partnership with the carriers and ensuring that all DOE materials, particularly hazardous and radioactive, are handled in a safe, compliant manner. Carriers are evaluated and rated based on their performance in those areas that are concerned with safety while in transit. This program is an essential part of the Department`s commitment to safety. Concern for safe disposal and storage of hazardous materials has often overshadowed the fact that, in many cases, these materials must be transported between various locations throughout the United States. The DOE Transportation of Emergency Management and Analytical Services (TEMAS) has made a commitment that, as these materials are transported, they are given the same care and safe handling by the carrier, as they are when moved internally (within DOE site boundaries). The Department continually monitors and analyzes its transportation activities to ensure public safety. As the DOE role shifts from nuclear materials production to environmental restoration, transportation continues to play an important part in the new mission. These widely dispersed hazardous materials (including radioactive materials) must be consolidated for safe storage and disposal, which will increase transportation operations across the DOE complex. For example, chemical wastes generated through years of defense production activities must be transported to commercial treatment, storage, and disposal (TSD) facilities.

  15. Sedimentation upon different carrier liquid in giant electrorheological fluid and its application

    NASA Astrophysics Data System (ADS)

    Hong, Yaying; Wen, Weijia

    2014-10-01

    When giant electrorheological (GER) fluid is settled after some time, particles can precipitate out of the oil in a multistep process that involves the formation of larger particles, the aggregation of colloids, and eventual sedimentation. Colloidal stability in giant electrorheological (GER) fluid can influence the GER performance and the fluid flow steadiness. We investigated the sedimentation effect of the GER particles suspended in various carrier liquid. Different from the existing electrorheological (ER) fluids, GER particles consisting of oxalate core with urea coating are found oil synergistic. The sedimentation effect of the particles suspended in oils from the family of synthetic oil and mineral oil were checked by direct observation. The rheological behavior of the GER fluid upon electric field application was also investigated. These experiments showed that stable colloidal suspension and good GER effect can be achieved coherently by favorable particle-oil interaction. The resultant high yield stress and low sedimentation rate achieved due to the instrumental linking of hydrogen bond is showed in the hydrogenated silicone oil carrier liquid. With the anti-sedimentation characteristic upon the new carrier oil, hydrogenated silicone oil-GER fluid, we investigated their GER effect in a modified mono tube damper and the experimental result showed wide controllability range. Our investigations may broaden engineering applications.

  16. A hydrogen energy carrier. Volume 2: Systems analysis

    NASA Technical Reports Server (NTRS)

    Savage, R. L. (Editor); Blank, L. (Editor); Cady, T. (Editor); Cox, K. (Editor); Murray, R. (Editor); Williams, R. D. (Editor)

    1973-01-01

    A systems analysis of hydrogen as an energy carrier in the United States indicated that it is feasible to use hydrogen in all energy use areas, except some types of transportation. These use areas are industrial, residential and commercial, and electric power generation. Saturation concept and conservation concept forecasts of future total energy demands were made. Projected costs of producing hydrogen from coal or from nuclear heat combined with thermochemical decomposition of water are in the range $1.00 to $1.50 per million Btu of hydrogen produced. Other methods are estimated to be more costly. The use of hydrogen as a fuel will require the development of large-scale transmission and storage systems. A pipeline system similar to the existing natural gas pipeline system appears practical, if design factors are included to avoid hydrogen environment embrittlement of pipeline metals. Conclusions from the examination of the safety, legal, environmental, economic, political and societal aspects of hydrogen fuel are that a hydrogen energy carrier system would be compatible with American values and the existing energy system.

  17. Transport of silver(I) ion through a supported liquid membrane using bathocuproine as a carrier

    SciTech Connect

    Saito, Takashi

    1998-04-01

    The active transport of silver ions through a supported liquid membrane (SLM) containing bathocuproine (4,7-diphenyl-2,9-dimethyl-1,10-phenanthroline) as a carrier was investigated under various experimental conditions. The magnitude of the permeation velocity of metallic ions through the SLM was in the order Ag{sup +} > Cd{sup 2+} {much_gt} Zn{sup 2+} > Cu{sup 2+} when nitrite ion was used as the pairing ion species that is cotransported with metallic ion. The permeation velocity of silver(I) ions through an SLM was dependent on the concentrations of the silver ion, bathocuproine, and nitrite ion. An equation for the transport of silver ions, consisting of three important factors, i.e., the concentrations of metallic ion, carrier, and pairing ion species, was derived.

  18. Carrier transport and localization in a one-dimensional electronic system over liquid helium

    NASA Astrophysics Data System (ADS)

    Gladchenko, S. P.; Nikolaenko, V. A.; Kovdrya, Yu. Z.; Sokolov, S. S.

    2001-01-01

    The carrier mobility in a nearly one-dimensional electronic system over liquid helium is measured. One-dimensional conducting channels are created by using the curvature of the surface of liquid helium covering a profiled dielectric substrate and applying a clamping electric field, which holds the electrons on the bottom of the liquid troughs. Measurements are made in a temperature interval of 0.5-1.6 K at linear densities in the range (0.5-2.5)×104 cm-1 at a generator voltage of 2-200 mV. It is shown that for a clean substrate the mobility of the electrons is governed by their interaction with helium atoms in the vapor and with ripplons; the results of the measurements are in satisfactory agreement with a theoretical calculation that assumes no localization. It is found that for substrates carrying a charge or having defects on the surface, the electron mobility decreases in comparison with the value for a clean substrate, and at temperatures T<1 K is either practically independent of temperature or decreases slightly as the temperature is lowered. It is observed that the frequency of the plasma waves propagating in the system of conducting channels decreases as the electron mobility decreases. The observed effects can be explained by localization in the one-dimensional electronic system in a random potential and the diffusive motion of the carriers in hops from one localized state to another.

  19. Multifunctional Catalysts to Synthesize and Utilize Energy Carriers

    SciTech Connect

    Lercher, Johannes A.; Appel, Aaron M.; Autrey, Thomas; Bullock, R. Morris; Camaioni, Donald M.; Cho, Herman M.; Dixon, David A.; Dohnalek, Zdenek; Gao, Feng; Glezakou, Vassiliki Alexandra; Henderson, Michael A.; Hu, Jian Z.; Iglesia, Enrique; Karkamkar, Abhijeet J.; Kay, Bruce D.; Kimmel, Gregory A.; Linehan, John C.; Liu, Jun; Lyubinetsky, Igor; Mei, Donghai; Peden, Charles HF; Rousseau, Roger J.; Schenter, Gregory K.; Shaw, Wendy J.; Szanyi, Janos; Wang, Huamin; Wang, Yong; Weber, Robert S.

    2014-06-23

    The central role and critical importance of catalysis in a future based on sustainability, together with the insight that developments have to be knowledge-based have motivated significant efforts to better understand catalyzed processes and to develop new catalytic routes from this knowledge. Overall, three main energy carriers are used worldwide, carbon (and hydrocarbons), hydrogen, and electrons. Conventionally, the stored energy is accessed by oxidizing carbon and hydrogen, forming O-H and C-O bonds and performing work with the produced heat or electricity. Conversely, to synthesize energy carriers sustainably, it is consequently required to reverse the direction, i.e., to break C-O and O-H bonds and form C-C, C-H and H-H bonds. To address these challenges, PNNL’s BES-sponsored program comprises three thrust areas with subtasks, focusing on the fundamentals of biomass conversion processes, direct and indirect CO2 reduction, and on elementary studies aimed at generating and using H2. Multi-functionality, i.e., the simultaneous interaction of more than one catalytically active site with the substrate is the key to achieving the atom and energy efficiency in individual steps. The combination of several types of these sites with carefully selected energetics and rate constants is used to generate complex catalysts able to enhance the rates of multistep processes. This short report summarizes recent results obtained in this BES-funded program.

  20. Transmitting Electromagnetic Energy into Liquids

    NASA Technical Reports Server (NTRS)

    Johnston, E. J.

    1984-01-01

    Rough liquid surface enhances coupling. Agitating surface of liquid nitrogen bath with periodic or aperiodic excitation enhances electromagnetic coupling between microwave horn and blackbody temperature standard immersed in liquid. Useful in interfaces between electromagnetic radiation and liquids. Biomedical, radar, and meteorological applications.

  1. Photo-generated carriers lose energy during extraction from polymer-fullerene solar cells

    PubMed Central

    Melianas, Armantas; Etzold, Fabian; Savenije, Tom J.; Laquai, Frédéric; Inganäs, Olle; Kemerink, Martijn

    2015-01-01

    In photovoltaic devices, the photo-generated charge carriers are typically assumed to be in thermal equilibrium with the lattice. In conventional materials, this assumption is experimentally justified as carrier thermalization completes before any significant carrier transport has occurred. Here, we demonstrate by unifying time-resolved optical and electrical experiments and Monte Carlo simulations over an exceptionally wide dynamic range that in the case of organic photovoltaic devices, this assumption is invalid. As the photo-generated carriers are transported to the electrodes, a substantial amount of their energy is lost by continuous thermalization in the disorder broadened density of states. Since thermalization occurs downward in energy, carrier motion is boosted by this process, leading to a time-dependent carrier mobility as confirmed by direct experiments. We identify the time and distance scales relevant for carrier extraction and show that the photo-generated carriers are extracted from the operating device before reaching thermal equilibrium. PMID:26537357

  2. Photo-generated carriers lose energy during extraction from polymer-fullerene solar cells.

    PubMed

    Melianas, Armantas; Etzold, Fabian; Savenije, Tom J; Laquai, Frédéric; Inganäs, Olle; Kemerink, Martijn

    2015-01-01

    In photovoltaic devices, the photo-generated charge carriers are typically assumed to be in thermal equilibrium with the lattice. In conventional materials, this assumption is experimentally justified as carrier thermalization completes before any significant carrier transport has occurred. Here, we demonstrate by unifying time-resolved optical and electrical experiments and Monte Carlo simulations over an exceptionally wide dynamic range that in the case of organic photovoltaic devices, this assumption is invalid. As the photo-generated carriers are transported to the electrodes, a substantial amount of their energy is lost by continuous thermalization in the disorder broadened density of states. Since thermalization occurs downward in energy, carrier motion is boosted by this process, leading to a time-dependent carrier mobility as confirmed by direct experiments. We identify the time and distance scales relevant for carrier extraction and show that the photo-generated carriers are extracted from the operating device before reaching thermal equilibrium. PMID:26537357

  3. Carrier-mediated extraction of bipyridilium herbicides across the hydrophobic liquid membrane.

    PubMed

    Mulugeta, Mesay; Megersa, Negussie

    2004-09-01

    Supported liquid membrane (SLM) method for preconcentration and enrichment of the two bipyridilium herbicides, namely diquat and paraquat, from environmental water samples has been developed. The permanently charged cationic herbicides were extracted from a flowing aqueous solution to a stagnant acidic acceptor solution across a liquid membrane containing 40% (v/v) di-(2-ethylhexyl) phosphoric acid dissolved in di-n-hexyl ether. The mass transfer of analytes is driven by the counter-coupled transport of hydrogen ions from the acceptor to the donor phase. The efficiency of the extraction process depends on the donor solution pH, the amount of the mobile carrier added to the liquid membrane and the concentration of the counter ion in the acceptor solution. The applicability of the method for extraction of these quaternary ammonium herbicides from environmental waters was also investigated by spiking analyte sample solutions in river water. With 24h sample enrichment concentrations of diquat and paraquat down to ca. 10ng/L could be detected in environmental waters. PMID:18969573

  4. Oil-in-water microemulsion globules as carriers of lipophilic substances across liquid membranes

    SciTech Connect

    Xenakis, A.; Tondre, C.

    1983-11-10

    The carrier properties of microemulsion droplets were investigated by using biphasic systems of the Winsor I type (constituted of an oil-phase floating on the top of an oil-in-water microemulsion phase). The systems investigated were constituted of sodium dodecyl sulfate/1-pentanol/n-dodecane/ (or brine). The microemulsion was used as a liquid membrane between 2 oil phases (a source phase and a receiving phase) and the rate of transfer of neutral arenes (pyrene, perylene, and anthracene), practically insoluble in the water continuous phase of the microemulsion, was determined from ultraviolet spectrophotometric measurements. The influence of different parameters on the transported solutes was studied: initial concentration of solute in the source phase, composition of the microemulsion, salt concentration. The results are shown to be consistent with a model in which the diffusion of droplets is coupled with a fast solubilization-desolubilization process and other possible mechanisms are critically examined. 32 references.

  5. Kinetics of Chromium(III) Transport Through a Liquid Membrane Containing DNNSA as a Carrier

    PubMed Central

    Religa, Paweł; Gawroński, Roman; Gierycz, Paweł

    2009-01-01

    Kinetics of Cr(III) ions transport through a bulk liquid membrane containing dinonylnaphthalenesulfonic acid (DNNSA) as a carrier, flowing over aqueous phases, has been examined. Special attention has been paid to the effect of the membrane’s velocity flow on the chromium concentration decrease in a feed phase. For the description of relationships of chromium(III) concentration in particular phases with the time, a model based on the assumption of consecutive first-order reactions was proposed. Satisfactory compatibility of experiments and model results have been obtained both for the membrane flow velocities below 0.0034 m·s−1 when the interfaces begin to fluctuate slightly and for low initial Cr(III) concentration in the feed phase. PMID:19399232

  6. Novel macrocyclic carriers for proton-coupled liquid membrane transport. Final report

    SciTech Connect

    Lamb, J.D.; Izatt, R.M.; Bradshaw, J.S.; Shirts, R.B.

    1996-08-24

    The objective of this research program is to elucidate the chemical principles which are responsible for the cation selectivity and permeability of liquid membranes containing macrocyclic carriers. Several new macrocyclic carriers were synthesized during the last three year period. In addition, new, more convenient synthetic routes were achieved for several nitrogen-containing bicyclic and tricyclic macrocycles. The cation binding properties of these macrocycles were investigated by potentiometric titration, calorimetric titration, solvent extraction and NMR techniques. In addition, hydrophobic macrocycles were incorporated into dual hollow fiber and other membrane systems to investigate their membrane performance, especially in the proton-coupled transport mode. A study of the effect of methoxyalkyl macrocycle substituents on metal ion transport was completed. A new calorimeter was constructed which made it possible to study the thermodynamics of macrocycle-cation binding to very high temperatures. Measurements of thermodynamic data for the interaction of crown ethers with alkali and alkaline earth cations were achieved to 473 K. Molecular modeling work was begun for the first time on this project and fundamental principles were identified and developed for the establishment of working models in the future.

  7. In-situ strain monitoring in liquid containers of LNG transporting carriers

    NASA Astrophysics Data System (ADS)

    Oh, Min-Cheol; Seo, Jun-Kyu; Kim, Kyung-Jo; Lee, Sang-Min; Kim, Myung-Hyun

    2008-08-01

    Liquefied natural gas (LNG) transport carriers are exposed to a risk by the repeated bump in the LNG container during the vessel traveling over the wave in ocean. The liquid inside the container, especially when it was not fully contained, make a strong bump onto the insulation panel of the tank wall. The insulation panel consists of several layers of thick polyurethane foam (PUF) to maintain the LNG below the cryogenic temperature, -162°C. Due to the repeated shock on the PUF, a crack could be developed on the tank wall causing a tremendous disaster for LNG carriers. To prevent the accidental crack on the tank, a continuous monitoring of the strain imposed on the PUF is recommended. In this work, a fiber-optic Bragg grating was imbedded inside the PUF for monitoring the strain parallel to the impact direction. The optical fiber sensor with a small diameter of 125 μm was suitable to be inserted in the PUF through a small hole drilled after the PUF was cured. In-situ monitoring of the strain producing the change of Bragg reflection wavelength, a high speed wavelength interrogation method was employed by using an arrayed waveguide grating. By dropping a heavy mass on the PUF, we measured the strain imposed on the insulation panel.

  8. Energy Models for One-Carrier Transport in Semiconductor Devices

    NASA Technical Reports Server (NTRS)

    Jerome, Joseph W.; Shu, Chi-Wang

    1991-01-01

    Moment models of carrier transport, derived from the Boltzmann equation, made possible the simulation of certain key effects through such realistic assumptions as energy dependent mobility functions. This type of global dependence permits the observation of velocity overshoot in the vicinity of device junctions, not discerned via classical drift-diffusion models, which are primarily local in nature. It was found that a critical role is played in the hydrodynamic model by the heat conduction term. When ignored, the overshoot is inappropriately damped. When the standard choice of the Wiedemann-Franz law is made for the conductivity, spurious overshoot is observed. Agreement with Monte-Carlo simulation in this regime required empirical modification of this law, or nonstandard choices. Simulations of the hydrodynamic model in one and two dimensions, as well as simulations of a newly developed energy model, the RT model, are presented. The RT model, intermediate between the hydrodynamic and drift-diffusion model, was developed to eliminate the parabolic energy band and Maxwellian distribution assumptions, and to reduce the spurious overshoot with physically consistent assumptions. The algorithms employed for both models are the essentially non-oscillatory shock capturing algorithms. Some mathematical results are presented and contrasted with the highly developed state of the drift-diffusion model.

  9. Effect of Column Disorder on Carrier Transport in Columnar Discotic Liquid Crystal Evaluated by Applying Precisely Controlled Shear Stress

    NASA Astrophysics Data System (ADS)

    Kim, Jaeki; Yamasaki, Naoyuki; Hayashi, Takeshi; Katayama, Mitsuyoshi; Yoshida, Hiroyuki; Moritake, Hiroshi; Fujii, Akihiko; Ozaki, Masanori

    2013-10-01

    The effect of column disorder on carrier drift mobility in columnar discotic liquid crystals has been investigated by applying a precisely controlled oscillating shear stress. Drift mobilities on the order of 10-1 cm2.V-1.s-1 were confirmed for positive and negative carriers in the columnar phase of 1,4,8,11,15,18,22,25-octahexylphthalocyanine in a well-aligned homeotropic geometry, in which the columnar axis was perfectly perpendicular to substrates with an electrode. A slight tilt of the columnar axis upon applying shear stress led to a marked decrease in electronic carrier mobility from 10-1 to less than 10-6 cm2.V-1.s-1, and transport was only confirmed for positive ion carriers. This result indicates that a uniform shear stress blocks the carrier transport path in the entire area of the electrode, and one-dimensional carrier transport path along the columns is easily hindered in columnar discotic liquid crystals.

  10. Model Catalytic Studies of Liquid Organic Hydrogen Carriers: Dehydrogenation and Decomposition Mechanisms of Dodecahydro-N-ethylcarbazole on Pt(111)

    PubMed Central

    2014-01-01

    Liquid organic hydrogen carriers (LOHC) are compounds that enable chemical energy storage through reversible hydrogenation. They are considered a promising technology to decouple energy production and consumption by combining high-energy densities with easy handling. A prominent LOHC is N-ethylcarbazole (NEC), which is reversibly hydrogenated to dodecahydro-N-ethylcarbazole (H12-NEC). We studied the reaction of H12-NEC on Pt(111) under ultrahigh vacuum (UHV) conditions by applying infrared reflection–absorption spectroscopy, synchrotron radiation-based high resolution X-ray photoelectron spectroscopy, and temperature-programmed molecular beam methods. We show that molecular adsorption of H12-NEC on Pt(111) occurs at temperatures between 173 and 223 K, followed by initial C–H bond activation in direct proximity to the N atom. As the first stable dehydrogenation product, we identify octahydro-N-ethylcarbazole (H8-NEC). Dehydrogenation to H8-NEC occurs slowly between 223 and 273 K and much faster above 273 K. Stepwise dehydrogenation to NEC proceeds while heating to 380 K. An undesired side reaction, C–N bond scission, was observed above 390 K. H8-NEC and H8-carbazole are the dominant products desorbing from the surface. Desorption occurs at higher temperatures than H8-NEC formation. We show that desorption and dehydrogenation activity are directly linked to the number of adsorption sites being blocked by reaction intermediates. PMID:24527267

  11. Energy loss behavior of photo-generated multi-component carriers in GaN

    NASA Astrophysics Data System (ADS)

    Yi, Kyung-Soo; Kim, Hye Jung; Kim, Do-Kyun

    2014-03-01

    Temporal behavior and many-body effect on the energy losses of photo-generated electron-hole plasma in GaN are examined in terms of various carrier-phonon couplings. We report a comprehensive cooling behavior as a function of effective carrier temperature over the temperature range of 10 -1500 K for carrier-phonon couplings via polar and nonpolar optical phonons and piezoelectric and acoustic deformation-potentials. The many-body effect on the multi-component carrier polarizations and phonon spectral function and effect of energy reabsorption via hot phonons are included by employing temperature-dependent dynamic responses in the rpa. We show that, as the carrier temperature decreases, the energy losses via carrier-optical phonon couplings diminish rapidly and the carrier energy relaxation is dominated through the acoustic phonon scattering at low carrier energy. From the energy loss rates, energy cooling curves are obtained as a function of time, and our result shows an initial gentle energy relaxation followed by fast relaxation. Spectral analysis of the dielectric response functions and energy loss rates are also performed and their dynamic and nonlocal behavior will be discussed. This research was supported in part by Basic Science Research Program through the NRF funded by the Ministry of Education (grant number 201306330001).

  12. Graphene, a material for high temperature devices – intrinsic carrier density, carrier drift velocity, and lattice energy

    PubMed Central

    Yin, Yan; Cheng, Zengguang; Wang, Li; Jin, Kuijuan; Wang, Wenzhong

    2014-01-01

    Heat has always been a killing matter for traditional semiconductor machines. The underlining physical reason is that the intrinsic carrier density of a device made from a traditional semiconductor material increases very fast with a rising temperature. Once reaching a temperature, the density surpasses the chemical doping or gating effect, any p-n junction or transistor made from the semiconductor will fail to function. Here, we measure the intrinsic Fermi level (|EF| = 2.93 kBT) or intrinsic carrier density (nin = 3.87 × 106 cm−2K−2·T2), carrier drift velocity, and G mode phonon energy of graphene devices and their temperature dependencies up to 2400 K. Our results show intrinsic carrier density of graphene is an order of magnitude less sensitive to temperature than those of Si or Ge, and reveal the great potentials of graphene as a material for high temperature devices. We also observe a linear decline of saturation drift velocity with increasing temperature, and identify the temperature coefficients of the intrinsic G mode phonon energy. Above knowledge is vital in understanding the physical phenomena of graphene under high power or high temperature. PMID:25044003

  13. Importance of liquid fragility for energy applications of ionic liquids.

    PubMed

    Sippel, P; Lunkenheimer, P; Krohns, S; Thoms, E; Loidl, A

    2015-01-01

    Ionic liquids (ILs) are salts that are liquid close to room temperature. Their possible applications are numerous, e.g., as solvents for green chemistry, in various electrochemical devices, and even for such "exotic" purposes as spinning-liquid mirrors for lunar telescopes. Here we concentrate on their use for new advancements in energy-storage and -conversion devices: Batteries, supercapacitors or fuel cells using ILs as electrolytes could be important building blocks for the sustainable energy supply of tomorrow. Interestingly, ILs show glassy freezing and the universal, but until now only poorly understood dynamic properties of glassy matter, dominate many of their physical properties. We show that the conductivity of ILs, an essential figure of merit for any electrochemical application, depends in a systematic way not only on their glass temperature but also on the so-called fragility, characterizing the non-canonical super-Arrhenius temperature dependence of their ionic mobility. PMID:26355037

  14. Importance of liquid fragility for energy applications of ionic liquids

    PubMed Central

    Sippel, P.; Lunkenheimer, P.; Krohns, S.; Thoms, E.; Loidl, A.

    2015-01-01

    Ionic liquids (ILs) are salts that are liquid close to room temperature. Their possible applications are numerous, e.g., as solvents for green chemistry, in various electrochemical devices, and even for such “exotic” purposes as spinning-liquid mirrors for lunar telescopes. Here we concentrate on their use for new advancements in energy-storage and -conversion devices: Batteries, supercapacitors or fuel cells using ILs as electrolytes could be important building blocks for the sustainable energy supply of tomorrow. Interestingly, ILs show glassy freezing and the universal, but until now only poorly understood dynamic properties of glassy matter, dominate many of their physical properties. We show that the conductivity of ILs, an essential figure of merit for any electrochemical application, depends in a systematic way not only on their glass temperature but also on the so-called fragility, characterizing the non-canonical super-Arrhenius temperature dependence of their ionic mobility. PMID:26355037

  15. Importance of liquid fragility for energy applications of ionic liquids

    NASA Astrophysics Data System (ADS)

    Sippel, P.; Lunkenheimer, P.; Krohns, S.; Thoms, E.; Loidl, A.

    2015-09-01

    Ionic liquids (ILs) are salts that are liquid close to room temperature. Their possible applications are numerous, e.g., as solvents for green chemistry, in various electrochemical devices, and even for such “exotic” purposes as spinning-liquid mirrors for lunar telescopes. Here we concentrate on their use for new advancements in energy-storage and -conversion devices: Batteries, supercapacitors or fuel cells using ILs as electrolytes could be important building blocks for the sustainable energy supply of tomorrow. Interestingly, ILs show glassy freezing and the universal, but until now only poorly understood dynamic properties of glassy matter, dominate many of their physical properties. We show that the conductivity of ILs, an essential figure of merit for any electrochemical application, depends in a systematic way not only on their glass temperature but also on the so-called fragility, characterizing the non-canonical super-Arrhenius temperature dependence of their ionic mobility.

  16. Liquid-phase microextraction of organophosphorus pesticides using supramolecular solvent as a carrier for ferrofluid.

    PubMed

    Zohrabi, Parvin; Shamsipur, Mojtaba; Hashemi, Mahdi; Hashemi, Beshare

    2016-11-01

    A liquid-phase microextraction based on application of supramolecular solvent as a carrier for ferrofluid has been developed for the extraction and determination of three organophosphorus pesticides (OPPs). The ferrofluid was produced from combination of oleic acid coated magnetic particles and supramolecular solvent as the extractant solvent. Ferrofluid can be attracted by a magnet, and no centrifugation step was needed for phase separation. A response surface methodology (RSM) based on central composite design (CCD) was used for efficient optimization of the main variables in the extraction procedure. Under the optimum experimental conditions, the calibration curves found to be linear in the range of 0.5-400µgL(-1) with correlation coefficients ranging from 0.9967 to 0.9984. The intra-day and inter-day precision (RSD %) for 100 and 200µgL(-1) of each pesticides were in the range of 2.0-5.3% and 2.6-5.7%, respectively. The limit of detection (S/N=3), ranged from 0.1 to 0.35μgL(-1). The proposed method was successfully applied to the extraction and determination of organophosphorus pesticide residues in water and fruit juice samples. PMID:27591622

  17. Thermal energy storage with liquid-liquid systems

    SciTech Connect

    Santana, E.A.; Stiel, L.I.

    1989-03-01

    The use of liquid-liquid mixtures for heat and cool storage applications has been investigated. Suitable mixtures exhibit large changes in the heat of mixing above and below the critical solution temperature of the system. Analytical procedures have been utilized to determine potential energy storage capabilities of systems with upper or lower critical solution temperatures. It has been found that aqueous systems with lower critical solution temperatures in a suitable range can result in large increases in the effective heat capacity in the critical region. For cool storage with a system of this type, the cooling process results in a transformation from two liquid phases to a single phase. Heats of mixing have been measured with a flow calorimeter system for a number of potential mixtures, and the results are summarized.

  18. Density Functional Theory Calculations of Activation Energies for Carrier Capture by Defects in Semiconductors

    NASA Astrophysics Data System (ADS)

    Modine, N. A.; Wright, A. F.; Lee, S. R.

    The rate of defect-induced carrier recombination is determined by both defect levels and carrier capture cross-sections. Density functional theory (DFT) has been widely and successfully used to predict defect levels, but only recently has work begun to focus on using DFT to determine carrier capture cross-sections. Lang and Henry developed the theory of carrier-capture by multiphonon emission in the 1970s and showed that carrier-capture cross-sections differ between defects primarily due to differences in their carrier capture activation energies. We present an approach to using DFT to calculate carrier capture activation energies that does not depend on an assumed configuration coordinate and that fully accounts for anharmonic effects, which can substantially modify carrier activation energies. We demonstrate our approach for intrinisic defects in GaAs and GaN and discuss how our results depend on the choice of exchange-correlation functional and the treatment of spin polarization. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under Contract DE-AC04-94AL85000.

  19. Extraction and carrier-facilitated transport of amino acids using synthetic non-cyclic receptors through bulk liquid membrane.

    PubMed

    Joshi, Pratibha; Joshi, Nidhi; Sharma, Uma

    2006-10-01

    The extraction and carrier-facilitated transport of amino acids (leucine, valine and glycine) was studied through chloroform bulk liquid membrane system using a series of non-cyclic receptors such as diethylene glycol (1), diethylene glycol dimethyl ether (2), diethylene glycol dibutyl ether (3), diethylene glycol dibenzoate (4), triethylene glycol (5) and tetraethylene glycol (6). The amount of amino acid extracted and transported depends mainly upon the structure and the concentration of the receptors and also on the concentration of amino acid. The receptors 1 to 4, having small chain length and flexible end groups, formed stable complexes with amino acids, and the flexibility of receptors in different conformational forms was responsible for their carrier ability, while the receptors 5 and 6, having larger chain length showed poor carrier ability. Hydrophobicity of amino acids also play an important role in the extraction as well as transport process. PMID:17133741

  20. Ionic liquids, electrolyte solutions including the ionic liquids, and energy storage devices including the ionic liquids

    SciTech Connect

    Gering, Kevin L.; Harrup, Mason K.; Rollins, Harry W.

    2015-12-08

    An ionic liquid including a phosphazene compound that has a plurality of phosphorus-nitrogen units and at least one pendant group bonded to each phosphorus atom of the plurality of phosphorus-nitrogen units. One pendant group of the at least one pendant group comprises a positively charged pendant group. Additional embodiments of ionic liquids are disclosed, as are electrolyte solutions and energy storage devices including the embodiments of the ionic liquid.

  1. Permeation rate of metal species through supported liquid membranes: diffusional and chemical resistances with cationic and anionic carriers

    SciTech Connect

    Danesi, P.R.; Horwitz, E.P.; Rickert, P.G.

    1983-01-01

    Facilitated transport by means of a mobile carrier in an organic diluent and adsorbed on a polymeric film, through supported liquid membranes (SLM), is a new method for the separation and recovery of metal ions. A permeability coefficient equation for this transport was tested. The facilitated transport of Cu/sup 2 +/ and Fe/sup 3 +/ ions through a SLM was characterized with respect to the membrane resistance. Transport of Am/sup 3 +/ through a SLM was also characterized. (DLC)

  2. Self-assembled multicompartment liquid crystalline lipid carriers for protein, peptide, and nucleic acid drug delivery.

    PubMed

    Angelova, Angelina; Angelov, Borislav; Mutafchieva, Rada; Lesieur, Sylviane; Couvreur, Patrick

    2011-02-15

    Lipids and lipopolymers self-assembled into biocompatible nano- and mesostructured functional materials offer many potential applications in medicine and diagnostics. In this Account, we demonstrate how high-resolution structural investigations of bicontinuous cubic templates made from lyotropic thermosensitive liquid-crystalline (LC) materials have initiated the development of innovative lipidopolymeric self-assembled nanocarriers. Such structures have tunable nanochannel sizes, morphologies, and hierarchical inner organizations and provide potential vehicles for the predictable loading and release of therapeutic proteins, peptides, or nucleic acids. This Account shows that structural studies of swelling of bicontinuous cubic lipid/water phases are essential for overcoming the nanoscale constraints for encapsulation of large therapeutic molecules in multicompartment lipid carriers. For the systems described here, we have employed time-resolved small-angle X-ray scattering (SAXS) and high-resolution freeze-fracture electronic microscopy (FF-EM) to study the morphology and the dynamic topological transitions of these nanostructured multicomponent amphiphilic assemblies. Quasi-elastic light scattering and circular dichroism spectroscopy can provide additional information at the nanoscale about the behavior of lipid/protein self-assemblies under conditions that approximate physiological hydration. We wanted to generalize these findings to control the stability and the hydration of the water nanochannels in liquid-crystalline lipid nanovehicles and confine therapeutic biomolecules within these structures. Therefore we analyzed the influence of amphiphilic and soluble additives (e.g. poly(ethylene glycol)monooleate (MO-PEG), octyl glucoside (OG), proteins) on the nanochannels' size in a diamond (D)-type bicontinuous cubic phase of the lipid glycerol monooleate (MO). At body temperature, we can stabilize long-living swollen states, corresponding to a diamond cubic phase

  3. Dependence of charge transfer reorganization energy on carrier localisation in organic molecular crystals.

    PubMed

    Bromley, Stefan T; Illas, Francesc; Mas-Torrent, Marta

    2008-01-01

    Taking the organic molecular material dithiophene-tetrathiafulvalene (DT-TTF) as an example of a high mobility organic molecular material, we use density functional calculations to calculate the dependency of the reorganization energy associated with charge carrier transport on: (i) the geometric and electronic responsiveness of the local molecular crystal environment, and, (ii) the local spatial extent of the charge carrier. We find that in our most realistic extended models the charge transfer reorganization energy is strongly dependent on carrier localization. In particular, whereas highly localized carriers are found to be highly susceptible to their charge transfer efficiency being affected by changes in the local crystal environment, more delocalized carriers are better able to maintain their low reorganization energies. Considering that maintaining a relatively small charge transfer reorganization energy magnitude is an important factor in achieving high carrier mobilities, we suggest that those materials better able to sustain carriers with short-range thermally resistant intermolecular delocalisation should be sought for device applications. PMID:18075690

  4. Importance of liquid fragility for energy applications of ionic liquids

    NASA Astrophysics Data System (ADS)

    Sippel, Pit; Lunkenheimer, Peter; Krohns, Stephan; Thoms, Erik; Loidl, Alois

    Ionic liquids (ILs) are salts that are liquid at ambient temperatures. The strong electrostatic forces between their molecular ions result, e.g., in low volatility and high stability for many members of this huge material class. For this reason they bear a high potential for new advancements in applications, e.g., as electrolytes in energy-storage devices such as supercapacitors or batteries, where the ionic conductivity is an essential figure of merit. Most ILs show dynamic properties typical for glassy matter, which dominate many of their physical properties. An important method to study these dynamical glass-properties is dielectric spectroscopy that can access relaxation times of dynamic processes and the conductivity in a broad frequency and temperature range. In the present contribution, we present results on a large variety of ionic liquids showing that the conductivity of ILs depends in a systematic way not only on their glass temperature but also on the so-called fragility, characterizing the non-canonical super-Arrhenius temperature dependence of their ionic mobility. This work was supported by the Deutsche Forschungsgemeinschaft via Research Unit FOR1394 and by the BMBF via ENREKON 03EK3015.

  5. Local energy landscape in a simple liquid

    SciTech Connect

    Iwashita, T.; Egami, Takeshi

    2014-11-26

    It is difficult to relate the properties of liquids and glasses directly to their structure because of complexity in the structure that defies precise definition. The potential energy landscape (PEL) approach is a very insightful way to conceptualize the structure-property relationship in liquids and glasses, particularly the effect of temperature and history. However, because of the highly multidimensional nature of the PEL it is hard to determine, or even visualize, the actual details of the energy landscape. In this article we introduce a modified concept of the local energy landscape (LEL), which is limited in phase space, and demonstrate its usefulness using molecular dynamics simulation on a simple liquid at high temperatures. The local energy landscape is given as a function of the local coordination number, the number of the nearest-neighbor atoms. The excitation in the LEL corresponds to the so-called β-relaxation process. The LEL offers a simple but useful starting point to discuss complex phenomena in liquids and glasses.

  6. Local energy landscape in a simple liquid

    DOE PAGESBeta

    Iwashita, T.; Egami, Takeshi

    2014-11-26

    It is difficult to relate the properties of liquids and glasses directly to their structure because of complexity in the structure that defies precise definition. The potential energy landscape (PEL) approach is a very insightful way to conceptualize the structure-property relationship in liquids and glasses, particularly the effect of temperature and history. However, because of the highly multidimensional nature of the PEL it is hard to determine, or even visualize, the actual details of the energy landscape. In this article we introduce a modified concept of the local energy landscape (LEL), which is limited in phase space, and demonstrate itsmore » usefulness using molecular dynamics simulation on a simple liquid at high temperatures. The local energy landscape is given as a function of the local coordination number, the number of the nearest-neighbor atoms. The excitation in the LEL corresponds to the so-called β-relaxation process. The LEL offers a simple but useful starting point to discuss complex phenomena in liquids and glasses.« less

  7. Plasmonic hot carrier dynamics in solid-state and chemical systems for energy conversion

    NASA Astrophysics Data System (ADS)

    Narang, Prineha; Sundararaman, Ravishankar; Atwater, Harry A.

    2016-06-01

    Surface plasmons provide a pathway to efficiently absorb and confine light in metallic nanostructures, thereby bridging photonics to the nano scale. The decay of surface plasmons generates energetic `hot' carriers, which can drive chemical reactions or be injected into semiconductors for nano-scale photochemical or photovoltaic energy conversion. Novel plasmonic hot carrier devices and architectures continue to be demonstrated, but the complexity of the underlying processes make a complete microscopic understanding of all the mechanisms and design considerations for such devices extremely challenging.Here,we review the theoretical and computational efforts to understand and model plasmonic hot carrier devices.We split the problem into three steps: hot carrier generation, transport and collection, and review theoretical approaches with the appropriate level of detail for each step along with their predictions.We identify the key advances necessary to complete the microscopic mechanistic picture and facilitate the design of the next generation of devices and materials for plasmonic energy conversion.

  8. Novel macrocyclic carriers for proton-coupled liquid membrane transport. Progress report, 1 December 1988--31 May 1991

    SciTech Connect

    Lamb, J.D.

    1991-06-10

    The objective of our research program is to elucidate the chemical principles which are responsible for the cation selectivity and permeability of liquid membranes containing macrocyclic carriers. Several new macrocyclic carriers were synthesized during the last three year period, including selenium-containing macrocycles, new crown-4 structures, and several new crown structures containing nitrogen based heterocycles as substituents in the principal macrocyclic ring. The cation binding properties of these macrocycles were investigated by potentiometric titration, calorimetric titration, solvent extraction, and NMR techniques. In addition, hydrophobic macrocycles were incorporated into dual hollow fiber membrane systems to investigate their membrane performance, especially in the proton-coupled transport mode. It was found that the dual hollow fiber system maintains the cation selectivity and permeability of supported liquid membranes, while enhancing membrane stability. The diffusion limited transport model was expanded to account for membrane solvent effects. Furthermore, Eu{sup 2+} transport was found to be similar to that of strontium and much higher than that of the lanthanides, in supported liquid membrane systems.

  9. Thermal and structural stability of medium energy target carrier assembly for NOvA at Fermilab

    SciTech Connect

    McGee, M.W.; Ader, C.; Anderson, K.; Hylen, J.; Martens, M.; /Fermilab

    2010-05-01

    The NOvA project will upgrade the existing Neutrino at Main Injector (NuMI) project beamline at Fermilab to accommodate beam power of 700 kW. The Medium Energy (ME) graphite target assembly is provided through an accord with the State Research Center of Russia Institute for High Energy Physics (IHEP) at Protvino, Russia. The effects of proton beam energy deposition within beamline components are considered as thermal stability of the target carrier assembly and alignment budget are critical operational issues. Results of finite element thermal and structural analysis involving the target carrier assembly is provided with detail regarding the target's beryllium windows.

  10. Semiconductor-free hot carrier devices for energy harvesting and photodetection

    NASA Astrophysics Data System (ADS)

    Gong, Tao; Munday, Jeremy

    The maximum efficiency for a single-junction solar cell is around 30% by the Shockley-Queisser (SQ) limit. The energy loss is typically through a thermalization process between the excited high-energy carriers, e.g. hot carriers, and the lattice. Therefore, the collection of the hot carriers before thermalization would allow for reduced power loss. Recently, photodetectors based on metal-semiconductor Schottky junctions have been exploiting hot electron effects to allow sub-bandgap absorption and hence show promise as near IR wavelength detectors. Here we present a simple, semiconductor-free hot carrier device based on transparent conducting oxides (TCO) electrodes. We experimentally demonstrate the hot carrier generation and extraction under monochromatic and broadband light illumination of normal and oblique incidence. Under optimized conditions, a power conversion efficiency >10% is predicted for high-energy photon excitation. The performance of the device shows further improvement by employing nanostructures, which couple the incident light into surface plasmons, leading to absorption enhancement. This semiconductor-free device provides an alternative way of energy harvesting and photodetection.

  11. Nuclear Energy and Synthetic Liquid Transportation Fuels

    NASA Astrophysics Data System (ADS)

    McDonald, Richard

    2012-10-01

    This talk will propose a plan to combine nuclear reactors with the Fischer-Tropsch (F-T) process to produce synthetic carbon-neutral liquid transportation fuels from sea water. These fuels can be formed from the hydrogen and carbon dioxide in sea water and will burn to water and carbon dioxide in a cycle powered by nuclear reactors. The F-T process was developed nearly 100 years ago as a method of synthesizing liquid fuels from coal. This process presently provides commercial liquid fuels in South Africa, Malaysia, and Qatar, mainly using natural gas as a feedstock. Nuclear energy can be used to separate water into hydrogen and oxygen as well as to extract carbon dioxide from sea water using ion exchange technology. The carbon dioxide and hydrogen react to form synthesis gas, the mixture needed at the beginning of the F-T process. Following further refining, the products, typically diesel and Jet-A, can use existing infrastructure and can power conventional engines with little or no modification. We can then use these carbon-neutral liquid fuels conveniently long into the future with few adverse environmental impacts.

  12. Liquid Scintillation Detectors for High Energy Neutrinos

    SciTech Connect

    Smith, Stefanie N.; Learned, John G.

    2010-03-30

    Large open volume (not segmented) liquid scintillation detectors have been generally dedicated to low energy neutrino measurements, in the MeV energy region. We describe the potential employment of large detectors (>1 kiloton) for studies of higher energy neutrino interactions, such as cosmic rays and long-baseline experiments. When considering the physics potential of new large instruments the possibility of doing useful measurements with higher energy neutrino interactions has been overlooked. Here we take into account Fermat's principle, which states that the first light to reach each PMT will follow the shortest path between that PMT and the point of origin. We describe the geometry of this process, and the resulting wavefront, which we are calling the 'Fermat surface', and discuss methods of using this surface to extract directional track information and particle identification. This capability may be demonstrated in the new long-baseline neutrino beam from Jaeri accelerator to the KamLAND detector in Japan. Other exciting applications include the use of Hanohano as a movable long-baseline detector in this same beam, and LENA in Europe for future long-baseline neutrino beams from CERN. Also, this methodology opens up the question as to whether a large liquid scintillator detector should be given consideration for use in a future long-baseline experiment from Fermilab to the DUSEL underground laboratory at Homestake.

  13. Methodology for the assessment of oxygen as an energy carrier

    NASA Astrophysics Data System (ADS)

    Yang, Ming Wei

    Due to the energy intensity of the oxygen generating process, the electric power grid would benefit if the oxygen generating process was consumed electric power only during low demand periods. Thus, the question to be addressed in this study is whether oxygen production and/or usage can be modified to achieve energy storage and/or transmission objectives at lower cost. The specific benefit to grid would be a leveling, over time, of the demand profile and thus would require less installation capacity. In order to track the availability of electricity, a compressed air storage unit is installed between the cryogenic distillation section and the main air compressor of air separation unit. A profit maximizing scheme for sizing storage inventory and related equipments is developed. The optimum scheme is capable of market responsiveness. Profits of steel maker, oxy-combustion, and IGCC plants with storage facilities can be higher than those plants without storage facilities, especially, at high-price market. Price tracking feature of air storage integration will certainly increase profit margins of the plants. The integration may push oxy-combustion and integrated gasification combined cycle process into economic viability. Since oxygen is used in consumer sites, it may generate at remote locations and transport to the place needed. Energy losses and costs analysis of oxygen transportation is conducted for various applications. Energy consumptions of large capacity and long distance GOX and LOX pipelines are lower than small capacity pipelines. However, transportation losses and costs of GOX and LOX pipelines are still higher than electricity transmission.

  14. Ionic liquid based lithium battery electrolytes: charge carriers and interactions derived by density functional theory calculations.

    PubMed

    Angenendt, Knut; Johansson, Patrik

    2011-06-23

    The solvation of lithium salts in ionic liquids (ILs) leads to the creation of a lithium ion carrying species quite different from those found in traditional nonaqueous lithium battery electrolytes. The most striking differences are that these species are composed only of ions and in general negatively charged. In many IL-based electrolytes, the dominant species are triplets, and the charge, stability, and size of the triplets have a large impact on the total ion conductivity, the lithium ion mobility, and also the lithium ion delivery at the electrode. As an inherent advantage, the triplets can be altered by selecting lithium salts and ionic liquids with different anions. Thus, within certain limits, the lithium ion carrying species can even be tailored toward distinct important properties for battery application. Here, we show by DFT calculations that the resulting charge carrying species from combinations of ionic liquids and lithium salts and also some resulting electrolyte properties can be predicted. PMID:21591707

  15. Determination of carrier yields for neutron activation analysis using energy dispersive X-ray spectrometry

    USGS Publications Warehouse

    Johnson, R.G.; Wandless, G.A.

    1984-01-01

    A new method is described for determining carrier yield in the radiochemical neutron activation analysis of rare-earth elements in silicate rocks by group separation. The method involves the determination of the rare-earth elements present in the carrier by means of energy-dispersive X-ray fluorescence analysis, eliminating the need to re-irradiate samples in a nuclear reactor after the gamma ray analysis is complete. Results from the analysis of USGS standards AGV-1 and BCR-1 compare favorably with those obtained using the conventional method. ?? 1984 Akade??miai Kiado??.

  16. Direct energy conversion using liquid metals

    NASA Astrophysics Data System (ADS)

    Onea, Alexandru; Diez de los Rios Ramos, Nerea; Hering, Wolfgang; Stieglitz, Robert; Moster, Peter

    2014-12-01

    Liquid metals have excellent properties to be used as heat transport fluids due to their high thermal conductivity and their wide applicable temperature range. The latter issue can be used to go beyond limitations of existing thermal solar energy systems. Furthermore, the direct energy converter Alkali Metal Thermo Electric Converter (AMTEC) can be used to make intangible areas of energy conversion suitable for a wide range of applications. One objective is to investigate AMTEC as a complementary cycle for the next generation of concentrating solar power (CSP) systems. The experimental research taking place in the Karlsruhe Institute of Technology (KIT) is focused on the construction of a flexible AMTEC test facility, development, test and improvement of liquid-anode and vapor-anode AMTEC devices as well as the coupling of the AMTEC cold side to the heat storage tank proposed for the CSP system. Within this project, the investigations foreseen will focus on the analyses of BASE-metal interface, electrode materials and deposition techniques, corrosion and erosion of materials brought in contact with high temperature sodium. This prototype demonstrator is planned to be integrated in the KArlsruhe SOdium LAboratory (KASOLA), a flexible closed mid-size sodium loop, completely in-house designed, presently under construction at the Institute for Neutron Physics and Reactor Technology (INR) within KIT.

  17. Order induced charge carrier mobility enhancement in columnar liquid crystal diodes.

    PubMed

    Eccher, Juliana; Faria, Gregório C; Bock, Harald; von Seggern, Heinz; Bechtold, Ivan H

    2013-11-27

    Discotic molecules comprising a rigid aromatic core and flexible side chains have been promisingly applied in OLEDs as self-organizing organic semiconductors. Due to their potentially high charge carrier mobility along the columns, device performance can be readily improved by proper alignment of columns throughout the bulk. In the present work, the charge mobility was increased by 5 orders of magnitude due to homeotropic columnar ordering induced by the boundary interfaces during thermal annealing in the mesophase. State-of-the-art diodes were fabricated using spin-coated films whose homeotropic alignment with formation of hexagonal germs was observed by polarizing optical microscopy. The photophysical properties showed drastic changes at the mesophase-isotropic transition, which is supported by the gain of order observed by X-ray diffraction. The electrical properties were investigated by modeling the current-voltage characteristics by a space-charge-limited current transport with a field dependent mobility. PMID:24191748

  18. Plasmonic hot carrier dynamics in solid-state and chemical systems for energy conversion

    DOE PAGESBeta

    Narang, Prineha; Sundararaman, Ravishankar; Atwater, Harry A.

    2016-06-11

    Surface plasmons provide a pathway to efficiently absorb and confine light in metallic nanostructures, thereby bridging photonics to the nano scale. The decay of surface plasmons generates energetic ‘hot’ carriers, which can drive chemical reactions or be injected into semiconductors for nano-scale photochemical or photovoltaic energy conversion. Novel plasmonic hot carrier devices and architectures continue to be demonstrated, but the complexity of the underlying processes make a complete microscopic understanding of all the mechanisms and design considerations for such devices extremely challenging.Here,we review the theoretical and computational efforts to understand and model plasmonic hot carrier devices.We split the problem intomore » three steps: hot carrier generation, transport and collection, and review theoretical approaches with the appropriate level of detail for each step along with their predictions. As a result, we identify the key advances necessary to complete the microscopic mechanistic picture and facilitate the design of the next generation of devices and materials for plasmonic energy conversion.« less

  19. Energy conversion at liquid/liquid interfaces: artificial photosynthetic systems

    NASA Technical Reports Server (NTRS)

    Volkov, A. G.; Gugeshashvili, M. I.; Deamer, D. W.

    1995-01-01

    This chapter focuses on multielectron reactions in organized assemblies of molecules at the liquid/liquid interface. We describe the thermodynamic and kinetic parameters of such reactions, including the structure of the reaction centers, charge movement along the electron transfer pathways, and the role of electric double layers in artificial photosynthesis. Some examples of artificial photosynthesis at the oil/water interface are considered, including water photooxidation to the molecular oxygen, oxygen photoreduction, photosynthesis of amphiphilic compounds and proton evolution by photochemical processes.

  20. Analysis of liquid metal embrittlement from a bond energy viewpoint

    NASA Technical Reports Server (NTRS)

    Kelley, M. J.; Stoloff, N. S.

    1975-01-01

    Absorption induced embrittlement of solid metals by certain liquid metals is analyzed through an Engel-Brewer calculation of the solid-liquid interaction energy, and of the effect of the latter in reducing fracture surface energy. The reduction in fracture surface energy is estimated by comparison of the electronic contribution to the solid-liquid interaction energy with solid-solid bond energy for some 40 liquid-solid couples. Regular solution theory is used to estimate mutual solubility as the relative difference in parameter values. Embrittlement can be predicted by using reduction in fracture surface energy and solubility parameter difference as critical variables. The effect of solute additions to the liquid on the degree of embrittlement is interpreted via the same two variables; the principal effect of solutes is to modify solubility relationships at the solid-liquid interface.

  1. Continuous flow hydroformylation using supported ionic liquid phase catalysts with carbon dioxide as a carrier.

    PubMed

    Hintermair, Ulrich; Gong, Zenxing; Serbanovic, Ana; Muldoon, Mark J; Santini, Catherine C; Cole-Hamilton, David J

    2010-09-28

    A supported ionic liquid phase (SILP) catalyst prepared from [PrMIM][Ph(2)P(3-C(6)H(4)SO(3))] (PrMIM = 1-propyl-3-methylimidazolium), [Rh(CO)(2)(acac)] (acacH = 2,4-pentanedione) [OctMIM]NTf(2) (OctMIM = 1-n-octyl-3-methylimidazolium, Tf = CF(3)SO(2)) and microporous silica has been used for the continuous flow hydroformylation of 1-octene in the presence of compressed CO(2). Statistical experimental design was used to show that the reaction rate is neither much affected by the film thickness (IL loading) nor by the syngas:substrate ratio. However, a factor-dependent interaction between the syngas:substrate ratio and film thickness on the reaction rate was revealed. Increasing the substrate flow led to increased reaction rates but lower overall yields. One of the most important parameters proved to be the phase behaviour of the mobile phase, which was studied by varying the reaction pressure. At low CO(2) pressures or when N(2) was used instead of CO(2) rates were low because of poor gas diffusion to the catalytic sites in the SILP. Furthermore, leaching of IL and Rh was high because the substrate is liquid and the IL had been designed to dissolve in it. As the CO(2) pressure was increased, the reaction rate increased and the IL and Rh leaching were reduced, because an expanded liquid phase developed. Due to its lower viscosity the expanded liquid allows better transport of gases to the catalyst and is a poorer solvent for the IL and the catalyst because of its reduced polarity. Above 100 bar (close to the transition to a single phase at 106 bar), the rate of reaction dropped again with increasing pressure because the flowing phase becomes a better and better solvent for the alkene, reducing its partitioning into the IL film. Under optimised conditions, the catalyst was shown to be stable over at least 40 h of continuous catalysis with a steady state turnover frequency (TOF, mol product (mol Rh)(-1)) of 500 h(-1) at low Rh leaching (0.2 ppm). The selectivity of the

  2. Modulation of phase behaviors and charge carrier mobilities by linkage length in discotic liquid crystal dimers.

    PubMed

    Wang, Yi-Fei; Zhang, Chun-Xiu; Wu, Hao; Zhang, Ao; Wang, Jian-Chuang; Zhang, Shuai-Feng; Pu, Jia-Ling

    2015-01-28

    A clear structure-property relationship was revealed in a series of triphenylene-based dimers, which contained two triphenylene nuclei each bearing five β-OC4H9 substituents and are linked through a flexible O(CH2)nO polymethylene chain (n=6-12). Dimers with the linkage close to twice the length of the free side chains (n=8, 9) exhibited a single Colhp phase, while others with the linkage shorter (n=6, 7) or longer (n=10, 11, 12) showed multiphase behaviors with a transition from the Colhp phase to Colh phase; hole mobilities of Colhp phases reached 1.4×10(-2) cm2 V(-1) s(-1) in the dimer for which the linkage is exactly twice the length of the free side chains (n=8), and decreased regularly both with linkage length becoming shorter or longer. This modulation of phase behaviors and charge carrier mobilities was demonstrated to be generated by various steric perturbations introduced by linkages with different lengths, which result in different degrees of lateral fluctuations of discotic moieties in the columns. PMID:25467212

  3. Carrier transport property of truxene discotic liquid crystals with three different ring substituents

    NASA Astrophysics Data System (ADS)

    Monobe, Hirosato; Ni, Hai-Liang; Hu, Ping; Wang, Bi-Qin; Zhao, Ke-Qing; Shimizu, Yo

    2016-03-01

    In this study, the charge carrier transport property of 3,8,13-trioctyloxytruxene [Trx(OC8)3] and its analogues, to which two different ring substituents of hydroxyl [Trx(OH)3(OC8)3] and methoxy [Trx(OMe)3(OC8)3] groups are introduced, has been studied relative to mesomorphism. Three analogues exhibit a hexagonal columnar (Colh) mesophase and their thermal stability increases with the introduction of hydroxyl and methoxy groups. The drift mobility measurements of Trx(OC8)3 and Trx(OH)3(OC8)3 reveal that the drift mobility is on the order of 5 × 10-2 cm2 V-1 s-1 in the Colh phase and it increases to 10-1 cm2 V-1 s-1 at the Colh-metastable phase transition, although Trx(OMe)3(OC8)3 shows a drift mobility of 1 × 10-2 cm2 V-1 s-1 in the Colh phase with temperature dependence. These results indicate that truxene with three alkoxy chains is an interesting molecular core for mesophase semiconductors.

  4. Complex and liquid hydrides for energy storage

    NASA Astrophysics Data System (ADS)

    Callini, Elsa; Atakli, Zuleyha Özlem Kocabas; Hauback, Bjørn C.; Orimo, Shin-ichi; Jensen, Craig; Dornheim, Martin; Grant, David; Cho, Young Whan; Chen, Ping; Hjörvarsson, Bjørgvin; de Jongh, Petra; Weidenthaler, Claudia; Baricco, Marcello; Paskevicius, Mark; Jensen, Torben R.; Bowden, Mark E.; Autrey, Thomas S.; Züttel, Andreas

    2016-04-01

    The research on complex hydrides for hydrogen storage was initiated by the discovery of Ti as a hydrogen sorption catalyst in NaAlH4 by Boris Bogdanovic in 1996. A large number of new complex hydride materials in various forms and combinations have been synthesized and characterized, and the knowledge regarding the properties of complex hydrides and the synthesis methods has grown enormously since then. A significant portion of the research groups active in the field of complex hydrides is collaborators in the International Energy Agreement Task 32. This paper reports about the important issues in the field of complex hydride research, i.e. the synthesis of borohydrides, the thermodynamics of complex hydrides, the effects of size and confinement, the hydrogen sorption mechanism and the complex hydride composites as well as the properties of liquid complex hydrides. This paper is the result of the collaboration of several groups and is an excellent summary of the recent achievements.

  5. Separation study of cadmium through an emulsion liquid membrane using triisooctylamine as mobile carrier.

    PubMed

    Li, Q M; Liu, Q; Zhang, Q F; Wei, X J; Guo, J Z

    1998-08-01

    A study of the transport of Cd(2+) ions through a triisooctylamine (TIOA)-sorbitan monooleate (Span 80)-dimethylbenzene liquid membrane has been performed with varying concentrations of HCl, KI, TIOA, Span 80 and NaOH in the feed, membrane and stripping solutions. Maximum transport was observed with 0.025 M HCl, 0.01 M KI, 0.02 M TIOA, 3% (w/v) Span 80 and 0.05 M NaOH. With this system cadmium could be completely separated with Cu(2+), Zn(2+), Fe(2+), Co(2+), Ni(2+), Mn(2+), Cr(3+) and Al(3+). The transport mechanism of this metal ions through the membrane has been discussed. PMID:18967215

  6. Altered Energy Metabolism Pathways in the Posterior Cingulate in Young Adult Apolipoprotein E ɛ4 Carriers.

    PubMed

    Perkins, Michelle; Wolf, Andrew B; Chavira, Bernardo; Shonebarger, Daniel; Meckel, J P; Leung, Lana; Ballina, Lauren; Ly, Sarah; Saini, Aman; Jones, T Bucky; Vallejo, Johana; Jentarra, Garilyn; Valla, Jon

    2016-04-23

    The APOE gene, encoding apolipoprotein E, is the primary genetic risk factor for late-onset Alzheimer's disease (AD). Apolipoprotein E ɛ4 allele (APOE4) carriers have alterations in brain structure and function (as measured by brain imaging) even as young adults. Examination of this population is valuable in further identifying details of these functional changes and their association with vulnerability to AD decades later. Previous work demonstrates functional declines in mitochondrial activity in the posterior cingulate cortex, a key region in the default mode network, which appears to be strongly associated with functional changes relevant to AD risk. Here, we demonstrate alterations in the pathways underlying glucose, ketone, and mitochondrial energy metabolism. Young adult APOE4 carriers displayed upregulation of specific glucose (GLUT1 & GLUT3) and monocarboxylate (MCT2) transporters, the glucose metabolism enzyme hexokinase, the SCOT & AACS enzymes involved in ketone metabolism, and complexes I, II, and IV of the mitochondrial electron transport chain. The monocarboxylate transporter (MCT4) was found to be downregulated in APOE4 carriers. These data suggest that widespread dysregulation of energy metabolism in this at-risk population, even decades before possible disease onset. Therefore, these findings support the idea that alterations in brain energy metabolism may contribute significantly to the risk that APOE4 confers for AD. PMID:27128370

  7. Altered Energy Metabolism Pathways in the Posterior Cingulate in Young Adult Apolipoprotein E ɛ4 Carriers

    PubMed Central

    Perkins, Michelle; Wolf, Andrew B.; Chavira, Bernardo; Shonebarger, Daniel; Meckel, J.P.; Leung, Lana; Ballina, Lauren; Ly, Sarah; Saini, Aman; Jones, T. Bucky; Vallejo, Johana; Jentarra, Garilyn; Valla, Jon

    2016-01-01

    The APOE gene, encoding apolipoprotein E, is the primary genetic risk factor for late-onset Alzheimer’s disease (AD). Apolipoprotein E ɛ4 allele (APOE4) carriers have alterations in brain structure and function (as measured by brain imaging) even as young adults. Examination of this population is valuable in further identifying details of these functional changes and their association with vulnerability to AD decades later. Previous work demonstrates functional declines in mitochondrial activity in the posterior cingulate cortex, a key region in the default mode network, which appears to be strongly associated with functional changes relevant to AD risk. Here, we demonstrate alterations in the pathways underlying glucose, ketone, and mitochondrial energy metabolism. Young adult APOE4 carriers displayed upregulation of specific glucose (GLUT1 & GLUT3) and monocarboxylate (MCT2) transporters, the glucose metabolism enzyme hexokinase, the SCOT & AACS enzymes involved in ketone metabolism, and complexes I, II, and IV of the mitochondrial electron transport chain. The monocarboxylate transporter (MCT4) was found to be downregulated in APOE4 carriers. These data suggest that widespread dysregulation of energy metabolism in this at-risk population, even decades before possible disease onset. Therefore, these findings support the idea that alterations in brain energy metabolism may contribute significantly to the risk that APOE4 confers for AD. PMID:27128370

  8. Ionic liquid-in-oil microemulsion as a potential carrier of sparingly soluble drug: characterization and cytotoxicity evaluation.

    PubMed

    Moniruzzaman, Muhammad; Tamura, Miki; Tahara, Yoshiro; Kamiya, Noriho; Goto, Masahiro

    2010-11-15

    Pharmaceutical industries have posed challenges in the topical and transdermal administration of drugs which are poorly soluble or insoluble in water and most of organic solvents. In an approach to overcome this limitation, ionic liquid-in-oil (IL/o) microemulsions (MEs) were employed to increase the solubility of a sparingly soluble drug to enhance its topical and transdermal delivery. The formulation of MEs was composed of a blend of nonionic surfactants, polyoxyethylene sorbitan monooleate (Tween-80) and sorbitan laurate (Span-20), isopropyl myristate (IPM) as an oil phase, and IL [C(1)mim] [(CH(3)O)(2)PO(2)] (dimethylimidazolium dimethylphosphate) as a pseudophase. Among various weight ratios of Tween-80 to Span-20 investigated in the ME systems, the ratio 3:2 showed excellent solubility and skin permeation enhancing effect for acyclovir (ACV) used as a model sparingly soluble drug. The size and size distribution of the ME droplets with and without drug were determined by dynamic light scattering. The permeability study of ACV incorporated in IL droplets as well as other formulations was performed into and across the Yucatan micropig (YMP) porcine skin, and the use of IL/o MEs has been shown to dramatically increase ACV administration. Finally, the cytotoxicity of the new carrier was evaluated in vitro using the reconstructed human epidermal model LabCyte™ EPI-MODEL12. It was found that the cell viability of IL/o MEs containing 4wt% IL was over 80% compared to Dulbecco's Phosphate-Buffered Salines, indicating low cytotoxicity of the carrier. Taken together these results, it can be assumed that IL-assisted nonaqueous ME could serve as a versatile and efficient nanodelivery system for insoluble or sparingly soluble drug molecules that require solubilizing agents for delivery. PMID:20813174

  9. A potential carrier based on liquid crystal nanoparticles for ophthalmic delivery of pilocarpine nitrate.

    PubMed

    Li, Jing; Wu, Lin; Wu, Weijun; Wang, Baoyan; Wang, Zhongyuan; Xin, Hongliang; Xu, Qunwei

    2013-10-15

    Poor corneal penetration and short preocular retention of a clinical hydrophilic drug, pilocarpine nitrate (PN), for the treatment of open-angle glaucoma and acute angle-closure glaucoma, limit its ocular application. The purpose of this study was to investigate the potential of liquid crystal nanoparticles (LCNPs) for ocular delivery of PN. LCNPs were developed by a top-down method using glyceryl monoolein (GMO) and water in the presence of stabilizer Poloxamer 407. They were characterized by transmission electron microscopy (TEM) and small angle X-ray diffraction (SAXS). The size of LCNP is 202.28±19.32 nm and the encapsulation efficiency reached 61.03%. The in vitro release profiles indicated that PN could keep sustained release from PN-loaded LCNPs for 8h. An ex vivo corneal permeation study revealed that the apparent permeability coefficient of PN-loaded LCNPs was 2.05-fold higher than that of commercial eye drops. In addition, the topical administration test showed that PN-loaded LCNPs had a prolonged effect on decreasing intraocular pressure (IOP) of rabbits compared with commercial drug and physiological saline. In conclusion, LCNPs had been demonstrated to be potential for controlled-release ocular drug delivery. PMID:23916822

  10. Assessment of the potential future market in Sweden for hydrogen as an energy carrier

    NASA Astrophysics Data System (ADS)

    Carleson, G.

    Future hydrogen markets for the period 1980-2025 are projected, the probable range of hydrogen production costs for various manufacturing methods is estimated, and expected market shares in competition with alternative energy carriers are evaluated. A general scenario for economic and industrial development in Sweden for the given period was evaluated, showing the average increase in gross national product to become 1.6% per year. Three different energy scenarios were then developed: alternatives were based on nuclear energy, renewable indigenous energy sources, and the present energy situation with free access to imported natural or synthetic fuels. An analysis was made within each scenario of the competitiveness of hydrogen on both the demand and the supply of the following sectors: chemical industry, steel industry, peak power production, residential and commercial heating, and transportation. Costs were calculated for the production, storage and transmission of hydrogen according to technically feasible methods and were compared to those of alternative energy carriers. Health, environmental and societal implications were also considered. The market penetration of hydrogen in each sector was estimated, and the required investment capital was shown to be less than 4% of the national gross investment sum.

  11. Carrier-mediated electrodialysis.

    PubMed

    Hansen, Steven P; Fyles, Thomas M

    2011-06-14

    Supported liquid membranes containing valinomycin or a calix[4]arene carrier can support electrodialysis under an imposed transmembrane potential. Under optimal conditions both transmembrane flux and carrier-based cation selectivity are enhanced relative to simple dialysis mediated by the same carriers. PMID:21308126

  12. Resonant tunneling diodes as energy-selective contacts used in hot-carrier solar cells

    NASA Astrophysics Data System (ADS)

    Takeda, Yasuhiko; Ichiki, Akihisa; Kusano, Yuya; Sugimoto, Noriaki; Motohiro, Tomoyoshi

    2015-09-01

    Among the four features unique to hot-carrier solar cells (HC-SCs): (i) carrier thermalization time and (ii) carrier equilibration time in the absorber, (iii) energy-selection width and (iv) conductance of the energy-selective contacts (ESCs), requisites of (i)-(iii) for high conversion efficiency have been clarified. We have tackled the remaining issues related to (iv) in the present study. The detailed balance model of HC-SC operation has been improved to involve a finite value of the ESC conductance to find the required values, which in turn has been revealed to be feasible using resonant tunneling diodes (RTDs) consisting of semiconductor quantum dots (QDs) and quantum wells (QWs) by means of a formulation to calculate the conductance of the QD- and QW-RTDs derived using the rigorous solutions of the effective-mass Hamiltonians. Thus, all of the four requisites unique to HC-SCs to achieve high conversion efficiency have been elucidated, and the two requisites related to the ESCs can be fulfilled using the QD- and QW-RTDs.

  13. Resonant tunneling diodes as energy-selective contacts used in hot-carrier solar cells

    SciTech Connect

    Takeda, Yasuhiko Sugimoto, Noriaki; Ichiki, Akihisa; Kusano, Yuya; Motohiro, Tomoyoshi

    2015-09-28

    Among the four features unique to hot-carrier solar cells (HC-SCs): (i) carrier thermalization time and (ii) carrier equilibration time in the absorber, (iii) energy-selection width and (iv) conductance of the energy-selective contacts (ESCs), requisites of (i)-(iii) for high conversion efficiency have been clarified. We have tackled the remaining issues related to (iv) in the present study. The detailed balance model of HC-SC operation has been improved to involve a finite value of the ESC conductance to find the required values, which in turn has been revealed to be feasible using resonant tunneling diodes (RTDs) consisting of semiconductor quantum dots (QDs) and quantum wells (QWs) by means of a formulation to calculate the conductance of the QD- and QW-RTDs derived using the rigorous solutions of the effective-mass Hamiltonians. Thus, all of the four requisites unique to HC-SCs to achieve high conversion efficiency have been elucidated, and the two requisites related to the ESCs can be fulfilled using the QD- and QW-RTDs.

  14. Anaerobic conversion of microalgal biomass to sustainable energy carriers--a review.

    PubMed

    Lakaniemi, Aino-Maija; Tuovinen, Olli H; Puhakka, Jaakko A

    2013-05-01

    This review discusses anaerobic production of methane, hydrogen, ethanol, butanol and electricity from microalgal biomass. The amenability of microalgal biomass to these bioenergy conversion processes is compared with other aquatic and terrestrial biomass sources. The highest energy yields (kJ g(-1) dry wt. microalgal biomass) reported in the literature have been 14.8 as ethanol, 14.4 as methane, 6.6 as butanol and 1.2 as hydrogen. The highest power density reported from microalgal biomass in microbial fuel cells has been 980 mW m(-2). Sequential production of different energy carriers increases attainable energy yields, but also increases investment and maintenance costs. Microalgal biomass is a promising feedstock for anaerobic energy conversion processes, especially for methanogenic digestion and ethanol fermentation. The reviewed studies have mainly been based on laboratory scale experiments and thus scale-up of anaerobic utilization of microalgal biomass for production of energy carriers is now timely and required for cost-effectiveness comparisons. PMID:23021960

  15. Powerful inner/outer controlled multi-target magnetic nanoparticle drug carrier prepared by liquid photo-immobilization

    PubMed Central

    Guan, Yan-Qing; Zheng, Zhe; Huang, Zheng; Li, Zhibin; Niu, Shuiqin; Liu, Jun-Ming

    2014-01-01

    Nanomagnetic materials offer exciting avenues for advancing cancer therapies. Most researches have focused on efficient delivery of drugs in the body by incorporating various drug molecules onto the surface of nanomagnetic particles. The challenge is how to synthesize low toxic nanocarriers with multi-target drug loading. The cancer cell death mechanisms associated with those nanocarriers remain unclear either. Following the cell biology mechanisms, we develop a liquid photo-immobilization approach to attach doxorubicin, folic acid, tumor necrosis factor-α, and interferon-γ onto the oleic acid molecules coated Fe3O4 magnetic nanoparticles to prepare a kind of novel inner/outer controlled multi-target magnetic nanoparticle drug carrier. In this work, this approach is demonstrated by a variety of structural and biomedical characterizations, addressing the anti-cancer effects in vivo and in vitro on the HeLa, and it is highly efficient and powerful in treating cancer cells in a valuable programmed cell death mechanism for overcoming drug resistance. PMID:24845203

  16. Powerful inner/outer controlled multi-target magnetic nanoparticle drug carrier prepared by liquid photo-immobilization

    NASA Astrophysics Data System (ADS)

    Guan, Yan-Qing; Zheng, Zhe; Huang, Zheng; Li, Zhibin; Niu, Shuiqin; Liu, Jun-Ming

    2014-05-01

    Nanomagnetic materials offer exciting avenues for advancing cancer therapies. Most researches have focused on efficient delivery of drugs in the body by incorporating various drug molecules onto the surface of nanomagnetic particles. The challenge is how to synthesize low toxic nanocarriers with multi-target drug loading. The cancer cell death mechanisms associated with those nanocarriers remain unclear either. Following the cell biology mechanisms, we develop a liquid photo-immobilization approach to attach doxorubicin, folic acid, tumor necrosis factor-α, and interferon-γ onto the oleic acid molecules coated Fe3O4 magnetic nanoparticles to prepare a kind of novel inner/outer controlled multi-target magnetic nanoparticle drug carrier. In this work, this approach is demonstrated by a variety of structural and biomedical characterizations, addressing the anti-cancer effects in vivo and in vitro on the HeLa, and it is highly efficient and powerful in treating cancer cells in a valuable programmed cell death mechanism for overcoming drug resistance.

  17. Energy Gap Tuning and Carrier Dynamics in Colloidal Ge1-xSnx Quantum Dots.

    PubMed

    Hafiz, Shopan A; Esteves, Richard J Alan; Demchenko, Denis O; Arachchige, Indika U; Özgür, Ümit

    2016-09-01

    Optical transition energies and carrier dynamics in colloidally synthesized 2.0 ± 0.8 nm Ge1-xSnx quantum dots (x = 0.055-0.236) having visible luminescence were investigated using steady-state and time-resolved photoluminescence (PL) spectroscopy supported by first-principles calculations. By changing Sn content from x = 0.055 to 0.236, experimentally determined HOMO-LUMO gap at 15 K was tuned from 1.88 to 1.61 eV. Considering the size and compositional variations, these values were consistent with theoretically calculated ones. At 15 K, time-resolved PL revealed slow decay of luminescence (3-27 μs), likely due to the recombination of spin-forbidden dark excitons and recombination of carriers trapped at surface states. Increasing Sn concentration to 23.6% led to 1 order of magnitude faster recombination. At 295 K, PL decays were 3 orders of magnitude faster (9-28 ns) owing to the thermal activation of bright excitons and carrier detrapping from surface states. PMID:27513723

  18. Thermodynamic Analysis of a Novel Liquid Air Energy Storage System

    NASA Astrophysics Data System (ADS)

    Xue, X. D.; Wang, S. X.; Zhang, X. L.; Cui, C.; Chen, L. B.; Zhou, Y.; Wang, J. J.

    In this study, a novel liquid air energy storage system for electrical power load shifting application is introduced. It is a combination of an air liquefaction cycle and a gas turbine power generation cycle without fuel combustion. Thermodynamic analysis is conducted to investigate the performance of this system. The results show that liquid air energy storage systems could be very effective systems for electrical power storage with high efficiency, high energy density and extensive application prospects.

  19. A liquid drop model for embedded atom method cluster energies

    NASA Technical Reports Server (NTRS)

    Finley, C. W.; Abel, P. B.; Ferrante, J.

    1996-01-01

    Minimum energy configurations for homonuclear clusters containing from two to twenty-two atoms of six metals, Ag, Au, Cu, Ni, Pd, and Pt have been calculated using the Embedded Atom Method (EAM). The average energy per atom as a function of cluster size has been fit to a liquid drop model, giving estimates of the surface and curvature energies. The liquid drop model gives a good representation of the relationship between average energy and cluster size. As a test the resulting surface energies are compared to EAM surface energy calculations for various low-index crystal faces with reasonable agreement.

  20. The effect of CdSe/ZnS quantum dots on the rotational viscosity and charge carrier concentration of a nematic liquid crystal

    NASA Astrophysics Data System (ADS)

    Shcherbinin, D. P.; Konshina, E. A.; Solodkov, D. E.

    2015-08-01

    The addition of CdSe/ZnS quantum dots (QDs) with a core diameter of 3.5 nm at a concentration of 10 wt % leads to a 2.5-fold increase in the dynamic rotational viscosity of a 5CB nematic liquid crystal (NLC). A comparison of the diffusion currents in NLC cells filled with pure 5CB and a suspension with QDs shows evidence of an increase in the concentration of charge carriers in the latter case.

  1. A perspective on liquid salts for energy and materials.

    PubMed

    Irvine, J T S

    2016-08-15

    Liquid salts comprising molten salts and ionic liquids offer important media to address both energy and materials challenges. Here we review topics presented in this Faraday Discussion volume related to improved electrowinning of metals, optimisation of processes, new electrochemical device concepts, chemistry in ionic liquids, conversion of biomass, carbon chemistry and nuclear applications. The underlying phenomenology is then reviewed and commentary given. Some future applications are then discussed, further exemplifying the high potential rewards achievable from these chemistries. PMID:27483385

  2. Separation of silver nanoparticles by hollow fiber flow field-flow fractionation: Addition of tannic acid into carrier liquid as a modifier.

    PubMed

    Saenmuangchin, Rattaporn; Mettakoonpitak, Jaruwan; Shiowatana, Juwadee; Siripinyanond, Atitaya

    2015-10-01

    A homemade hollow fiber flow-field fractionation (Hf-FlFFF) coupled with inductively coupled plasma mass spectrometry (ICP-MS) was set-up for silver nanoparticles (AgNPs) separation by using polysulfone hollow fiber membrane (30,000 MW cutoff) as a separation channel. Tannic acid and citrate stabilized AgNPs were synthesized and introduced into Hf-FlFFF. The effects of carrier liquid and stabilizing agent on retention behavior of AgNPs were investigated. Different elution behaviors were observed as follows: with 0.02% (w/v) FL-70, all of AgNPs were eluted from Hf-FlFFF but differences in retention behaviors were observed for AgNPs with tannic acid and citrate stabilizing agents; and with 30mM TRIS buffer, only tannic acid stabilized AgNPs were eluted from Hf-FlFFF, whereas citrate stabilized AgNPs were not eluted. In this work, tannic acid addition into carrier liquid was proposed to modify the surface of AgNPs and the surface of the membrane, and thereby adjusting the retention behaviors of AgNPs. Various concentrations of tannic acid were added into FL-70 and TRIS buffer. With the use of 0.1mM tannic acid in 30mM TRIS buffer as the carrier liquid, retention behaviors of both tannic acid stabilized- and citrate stabilized-AgNPs were similar and with similar fractionation recovery. PMID:26341593

  3. Energy Efficient Electrochromic Windows Incorporating Ionic Liquids

    SciTech Connect

    Cheri Boykin; James Finley; Donald Anthony; Julianna Knowles; Richard Markovic; Michael Buchanan; Mary Ann Fuhry; Lisa Perrine

    2008-11-30

    One approach to increasing the energy efficiency of windows is to control the amount of solar radiation transmitted through a window by using electrochromic technology. What is unique about this project is that the electrochromic is based on the reduction/oxidation reactions of cathodic and anodic organic semi-conducting polymers using room temperature ionic liquids as ion transport electrolytes. It is believed that these types of coatings would be a lower cost alternative to traditional all inorganic thin film based electrochromic technologies. Although there are patents1 based on the proposed technology, it has never been reduced to practice and thoroughly evaluated (i.e. durability and performance) in a window application. We demonstrate that by using organic semi-conductive polymers, specific bands of the solar spectrum (specifically visible and near infrared) can be targeted for electrochemical variable transmittance responsiveness. In addition, when the technology is incorporated into an insulating glass unit, the energy parameters such as the solar heat gain coefficient and the light to solar gain ratio are improved over that of a typical insulating glass unit comprised of glass with a low emissivity coating. A minimum of {approx}0.02 quads of energy savings per year with a reduction of carbon emissions for electricity of {approx}320 MKg/yr benefit is achieved over that of a typical insulating glass unit including a double silver low-E coating. Note that these values include a penalty in the heating season. If this penalty is removed (i.e. in southern climates or commercial structures where cooling is predominate year-round) a maximum energy savings of {approx}0.05 quad per year and {approx}801 MKg/yr can be achieved over that of a typical insulating glass unit including a double silver low-E coating. In its current state, the technology is not durable enough for an exterior window application. The primary downfall is that the redox chemistry fails to

  4. Energy dispersive-EXAFS of Pd nucleation at a liquid/liquid interface

    NASA Astrophysics Data System (ADS)

    Chang, S.-Y.; Booth, S. G.; Uehara, A.; Mosselmans, J. F. W.; Cibin, G.; Pham, V.-T.; Nataf, L.; Dryfe, R. A. W.; Schroeder, S. L. M.

    2016-05-01

    Energy dispersive extended X-ray absorption fine structure (EDE) has been applied to Pd nanoparticle nucleation at a liquid/liquid interface under control over the interfacial potential and thereby the driving force for nucleation. Preliminary analysis focusing on Pd K edge-step height determination shows that under supersaturated conditions the concentration of Pd near the interface fluctuate over a period of several hours, likely due to the continuous formation and dissolution of sub-critical nuclei. Open circuit potential measurements conducted ex-situ in a liquid/liquid electrochemical cell support this view, showing that the fluctuations in Pd concentration are also visible as variations in potential across the liquid/liquid interface. By decreasing the interfacial potential through inclusion of a common ion (tetraethylammonium, TEA+) the Pd nanoparticle growth rate could be slowed down, resulting in a smooth nucleation process. Eventually, when the TEA+ ions reached an equilibrium potential, Pd nucleation and particle growth were inhibited.

  5. Carrier scattering processes and low energy phonon spectroscopy in hybrid perovskites crystals

    NASA Astrophysics Data System (ADS)

    Even, Jacky; Paofai, Serge; Bourges, Philippe; Letoublon, Antoine; Cordier, Stéphane; Durand, Olivier; Katan, Claudine

    2016-03-01

    Despite the wealth of research conducted the last three years on hybrid organic perovskites (HOP), several questions remain open including: to what extend the organic moiety changes the properties of the material as compared to allinorganic (AIP) related perovskite structures. To ultimately reach an answer to this question, we have recently introduced two approaches that were designed to take the stochastic molecular degrees of freedom into account, and suggested that the high temperature cubic phase of HOP and AIP is an appropriate reference phase to rationalize HOP's properties. In this paper, we recall the main concepts and discuss more specifically the various possible couplings between charge carriers and low energy excitations such as acoustic and optical phonons. As available experimental or simulated data on low energy excitations are limited, we also present preliminary neutron scattering and ultrasonic measurements obtained and freshly prepared single crystals of CH3NH3PbBr3.

  6. Dependence of solid-liquid interface free energy on liquid structure

    SciTech Connect

    Wilson, S R; Mendelev, M I

    2014-09-01

    The Turnbull relation is widely believed to enable prediction of solid–liquid interface (SLI) free energies from measurements of the latent heat and the solid density. Ewing proposed an additional contribution to the SLI free energy to account for variations in liquid structure near the interface. In the present study, molecular dynamics (MD) simulations were performed to investigate whether SLI free energy depends on liquid structure. Analysis of the MD simulation data for 11 fcc metals demonstrated that the Turnbull relation is only a rough approximation for highly ordered liquids, whereas much better agreement is observed with Ewing’s theory. A modification to Ewing’s relation is proposed in this study that was found to provide excellent agreement with MD simulation data.

  7. A volatile fluid assisted thermo-pneumatic liquid metal energy harvester

    NASA Astrophysics Data System (ADS)

    Tang, Jianbo; Wang, Junjie; Liu, Jing; Zhou, Yuan

    2016-01-01

    A close-cycle self-driving thermal energy harvester using liquid metal as energy carrier fluid has been proposed. The driving force that pushes the liquid metal against flow resistance and gravity is provided by a resistively heated volatile fluid based on thermo-pneumatic principle. The tested harvester prototype demonstrated its capability to extract thermal energy between small temperature gradient, at a scale of 10 °C. During a 5-h operation, it further demonstrated robust liquid metal recirculating performance at a time-average volume flow rate of 14 ml/min with a 12.25 W heating load. The prototype also managed to self-adjust to variable working conditions which indicated the reliability of this method. Advantages of this method include simple-structural design, rigid-motion free operation, and low-temperature actuation. These advantages make it uniquely suited for solar energy and low-grade heat harvesting, high heat flux electronics cooling, as well as autonomous machines actuating.

  8. Measurement of the liquid scintillator nonlinear energy response to electron

    NASA Astrophysics Data System (ADS)

    Zhang, Fei-Hong; Yu, Bo-Xiang; Hu, Wei; Yang, Ma-Sheng; Cao, Guo-Fu; Cao, Jun; Zhou, Li

    2015-01-01

    Nonlinearity of the liquid scintillator energy response is a key to measuring the neutrino energy spectrum in reactor neutrino experiments such as Daya Bay and JUNO. We measured the nonlinearity of the linear alkyl benzene based liquid scintillator in the laboratory, which is used in Daya Bay and will be used in JUNO, via the Compton scattering process. By tagging the scattered gamma from the liquid scintillator sample simultaneously at seven angles, the instability of the system was largely cancelled. The accurately measured nonlinearity will improve the precision of the θ13, Δm2, and reactor neutrino spectrum measurements at Daya Bay.

  9. A hydrogen energy carrier. Volume 1: Summary. [for meeting energy requirements

    NASA Technical Reports Server (NTRS)

    Savage, R. L. (Editor); Blank, L. (Editor); Cady, T. (Editor); Cox, K. E. (Editor); Murray, R. (Editor); Williams, R. D. (Editor)

    1973-01-01

    The production, technology, transportation, and implementation of hydrogen into the energy system are discussed along with the fossil fuel cycle, hydrogen fuel cycle, and the demands for energy. The cost of hydrogen production by coal gasification; electrolysis by nuclear energy, and solar energy are presented. The legal aspects of a hydrogen economy are also discussed.

  10. Characterization of gelation process and drug release profile of thermosensitive liquid lecithin/poloxamer 407 based gels as carriers for percutaneous delivery of ibuprofen.

    PubMed

    Djekic, Ljiljana; Krajisnik, Danina; Martinovic, Martina; Djordjevic, Dragana; Primorac, Marija

    2015-07-25

    Suitability of liquid lecithin (i.e., solution of lecithin in soy bean oil with ∼ 60% w/w of phospholipids) for formation of gels, upon addition of water solution of poloxamer 407, was investigated, and formulated systems were evaluated as carriers for percutaneous delivery of ibuprofen. Formulation study of pseudo-ternary system liquid lecithin/poloxamer 407/water at constant liquid lecithin/poloxamer 407 mass ratio (2.0) revealed that minimum concentrations of liquid lecithin and poloxamer 407 required for formation of gel like systems were 15.75% w/w and 13.13% w/w, respectively, while the maximum content of water was 60.62% w/w. The systems comprising water concentrations in a range from 55 to 60.62% w/w were soft semisolids suitable for topical application, and they were selected for physicochemical and biopharmaceutical evaluation. Analysis of conductivity results and light microscopy examination revealed that investigated systems were water dilutable dispersions of spherical oligolamellar associates of phospholipids and triglyceride molecules in the copolymer water solution. Rheological behavior evaluation results indicated that the investigated gels were thermosensitive shear thinning systems. Ibuprofen (5% w/w) was incorporated by dispersing into the previously prepared carriers. Drug-loaded systems were physically stable at storage temperature from 5 ± 3°C to 40 ± 2°C, for 30 days. In vitro ibuprofen release was in accordance with the Higuchi model (rH>0.95) and sustained for 12h. The obtained results implicated that formulated LLPBGs, optimized regarding drug release and organoleptic properties, represent promising carriers for sustained percutaneous drug delivery of poorly soluble drugs. PMID:26002567

  11. Thermodynamic analysis of alternate energy carriers, hydrogen and chemical heat pipes

    NASA Technical Reports Server (NTRS)

    Cox, K. E.; Carty, R. H.; Conger, W. L.; Soliman, M. A.; Funk, J. E.

    1976-01-01

    The paper discusses the production concept and efficiency of two new energy transmission and storage media intended to overcome the disadvantages of electricity as an overall energy carrier. These media are hydrogen produced by water-splitting and the chemical heat pipe. Hydrogen can be transported or stored, and burned as energy is needed, forming only water and thus obviating pollution problems. The chemical heat pipe envisions a system in which heat is stored as the heat of reaction in chemical species. The thermodynamic analysis of these two methods is discussed in terms of first-law and second-law efficiency. It is concluded that chemical heat pipes offer large advantages over thermochemical hydrogen generation schemes on a first-law efficiency basis except for the degradation of thermal energy in temperature thus providing a source of low-temperature (800 K) heat for process heat applications. On a second-law efficiency basis, hydrogen schemes are superior in that the amount of available work is greater as compared to chemical heat pipes.

  12. Study of energy eigenvalues and density of states of carriers in a triangular quantum wire

    NASA Astrophysics Data System (ADS)

    Deyasi, Arpan; Bhattacharyya, S.; Das, N. R.

    2012-10-01

    Energy eigenvalues and density of states of carriers in a finite barrier triangular quantum wire embedded inside a rectangular quantum wire are numerically investigated using finite difference technique (FD-Q). Time-independent Schrödinger's equation is solved with appropriate boundary conditions for computation of lowest three eigenstates. The wire is made of lower bandgap GaAs material surrounded by wider bandgap AlxGa1-xAs, and the analysis is carried out by taking into consideration of the conduction band discontinuity and effective mass mismatch at the boundaries. The eigenvalues and the density of states are plotted as function of wire dimension and mole fraction (x). The results are also compared with those obtained using rectangular quantum wire.

  13. Characterization of hydrophobic nanoporous particle liquids for energy absorption

    NASA Astrophysics Data System (ADS)

    Hsu, Yi; Liu, Yingtao

    2016-04-01

    Recently, the development of hydrophobic nanoporous technologies has drawn increased attention, especially for the applications of energy absorption and impact protection. Although significant amount of research has been conducted to synthesis and characterize materials to protect structures from impact damage, the tradition methods focused on converting kinetic energy to other forms, such as heat and cell buckling. Due to their high energy absorption efficiency, hydrophobic nanoporous particle liquids (NPLs) are one of the most attractive impact mitigation materials. During impact, such particles directly trap liquid molecules inside the non-wetting surface of nanopores in the particles. The captured impact energy is simply stored temporarily and isolated from the original energy transmission path. In this paper we will investigate the energy absorption efficiency of combinations of silica nanoporous particles and with multiple liquids. Inorganic particles, such as nanoporous silica, are characterized using scanning electron microscopy. Small molecule promoters, such as methanol and ethanol, are introduced to the prepared NPLs. Their effects on the energy absorption efficiency are studied in this paper. NPLs are prepared by dispersing the studied materials in deionized water. Energy absorption efficiency of these liquids are experimentally characterized using an Instron mechanical testing frame and in-house develop stainless steel hydraulic cylinder system.

  14. Solid/liquid interfacial free energies in binary systems

    NASA Technical Reports Server (NTRS)

    Nason, D.; Tiller, W. A.

    1973-01-01

    Description of a semiquantitative technique for predicting the segregation characteristics of smooth interfaces between binary solid and liquid solutions in terms of readily available thermodynamic parameters of the bulk solutions. A lattice-liquid interfacial model and a pair-bonded regular solution model are employed in the treatment with an accommodation for liquid interfacial entropy. The method is used to calculate the interfacial segregation and the free energy of segregation for solid-liquid interfaces between binary solutions for the (111) boundary of fcc crystals. The zone of compositional transition across the interface is shown to be on the order of a few atomic layers in width, being moderately narrower for ideal solutions. The free energy of the segregated interface depends primarily upon the solid composition and the heats of fusion of the component atoms, the composition difference of the solutions, and the difference of the heats of mixing of the solutions.

  15. Probing battery chemistry with liquid cell electron energy loss spectroscopy

    DOE PAGESBeta

    Unocic, Raymond R.; Baggetto, Loic; Veith, Gabriel M.; Unocic, Kinga A.; Sacci, Robert L.; Dudney, Nancy J.; More, Karren Leslie; Aguiar, Jeffery A.

    2015-09-15

    Electron energy loss spectroscopy (EELS) was used to determine the chemistry and oxidation state of LiMn2O4 and Li4Ti5O12 thin film battery electrodes in liquid cells for in situ scanning/transmission electron microscopy (S/TEM). Using the L2,3 white line intensity ratio method we determine the oxidation state of Mn and Ti in a liquid electrolyte solvent and discuss experimental parameters that influence measurement sensitivity.

  16. Orientational energy of anisometric particles in liquid-crystalline suspensions

    NASA Astrophysics Data System (ADS)

    Burylov, S. V.; Zakhlevnykh, A. N.

    2013-07-01

    We obtain a general expression for the orientational energy of an individual anisometric particle suspended in uniform nematic liquid crystals when the main axis of the particle rotates with respect to the nematic director. We show that there is a qualitative and quantitative analogy between the internal and external problems for cylindrical volumes of nematic liquid crystals, and on this basis we obtain an estimate of the orientational energy of a particle of cylindrical (rodlike, needlelike, or ellipsoidal) shape. For an ensemble of such particles we propose a modified form of their orientational energy in the nematic matrix. This orientational energy has the usual second-order term, and additional fourth-order term in the scalar product of the nematic director and the vector which characterizes an average direction of the main axes of the particles. As an example we obtain the expression for the free energy density of ferronematics, i.e., colloidal suspensions of needlelike magnetic particles in nematic liquid crystals. Unlike previous models, the free energy density includes the proposed modified form of the particle orientational energy, and also a contribution describing the surface saddle-splay deformations of the liquid crystal matrix.

  17. The switching mechanism of the mitochondrial ADP/ATP carrier explored by free-energy landscapes.

    PubMed

    Pietropaolo, Adriana; Pierri, Ciro Leonardo; Palmieri, Ferdinando; Klingenberg, Martin

    2016-06-01

    The ADP/ATP carrier (AAC) of mitochondria has been an early example for elucidating the transport mechanism alternating between the external (c-) and internal (m-) states (M. Klingenberg, Biochim. Biophys. Acta 1778 (2008) 1978-2021). An atomic resolution crystal structure of AAC is available only for the c-state featuring a three repeat transmembrane domain structure. Modeling of transport mechanism remained hypothetical for want of an atomic structure of the m-state. Previous molecular dynamics studies simulated the binding of ADP or ATP to the AAC remaining in the c-state. Here, a full description of the AAC switching from the c- to the m-state is reported using well-tempered metadynamics simulations. Free-energy landscapes of the entire translocation from the c- to the m-state, based on the gyration radii of the c- and m-gates and of the center of mass, were generated. The simulations revealed three free-energy basins attributed to the c-, intermediate- and m-states separated by activation barriers. These simulations were performed with the empty and with the ADP- and ATP-loaded AAC as well as with the poorly transported AMP and guanine nucleotides, showing in the free energy landscapes that ADP and ATP lowered the activation free-energy barriers more than the other substrates. Upon binding AMP and guanine nucleotides a deeper free-energy level stabilized the intermediate-state of the AAC2 hampering the transition to the m-state. The structures of the substrate binding sites in the different states are described producing a full picture of the translocation events in the AAC. PMID:26874054

  18. Identification of deep trap energies and influences of oxygen plasma ashing on semiconductor carrier lifetime

    NASA Astrophysics Data System (ADS)

    Koprowski, A.; Humbel, O.; Plappert, M.; Krenn, H.

    2015-03-01

    We have performed an analytical study of the effects of oxygen plasma ashing processes in semiconductor device fabrication and its impact on minority carrier lifetime in high voltage semiconductor devices. Our work includes a critical background study of life time killing mechanisms by deep traps imparted into the semiconductor by barrel plasma ashing. The Elymat technique provides the opportunity to measure lifetime and diffusion length of minority carriers and surface photo voltage (SPV) measurement was used to analyse influences of process parameters such as photoresist, time budget and positioning in the process chamber. It was shown that in microwave plasma processes the diffusion length changes severely with tempering at 200 °C, whereas RF-plasma processes show a significant process time-dependence. Batch tools in general suffer from a strong first wafer effect which could be correlated with the static electrical parameters of the semiconductor devices. The trap identities were detected by using deep level transient spectroscopy and the chemical species of the traps has been proven by inductive coupled plasma mass spectrometry. The deep-bandgap trap energies are reliable fingerprints of the chosen process parameters such as process time and of resist-influences. By microwave plasma processes intrinsic Fe and FeB-complex levels were identified and a good agreement with the SPV-measurement and electrical device characteristic was shown. RF-plasma processes impart levels attributed to Pt levels and an additional level, which could be identified as a trap level probably forming a complex of Pt and H.

  19. Electric field dependence of charge carrier hopping transport within the random energy landscape in an organic field effect transistor

    NASA Astrophysics Data System (ADS)

    Fishchuk, I. I.; Kadashchuk, A.; Ullah, Mujeeb; Sitter, H.; Pivrikas, A.; Genoe, J.; Bässler, H.

    2012-07-01

    We extended our analytical effective medium theory [Phys. Rev. BPRBMDO0163-182910.1103/PhysRevB.81.045202 81, 045202 (2010)] to describe the temperature-dependent hopping charge carrier mobility at arbitrary electric fields in the large carrier density regime. Special emphasis was made to analyze the influence of the lateral electric field on the Meyer-Neldel (MN) phenomenon observed when studying the charge mobilities in thin-film organic field-effect transistors (OFET). Our calculations are based on the average hopping transition time approach, generalized for large carrier concentration limit finite fields, and taking into account also spatial energy correlations. The calculated electric field dependences of the hopping mobility at large carrier concentrations are in good agreement with previous computer simulations data. The shift of the MN temperature in an OFET upon applied electric field is shown to be a consequence of the spatial energy correlation in the organic semiconductor film. Our calculations show that the phenomenological Gill equation is clearly inappropriate for describing conventional charge carrier transport at low carrier concentrations. On the other hand a Gill-type behavior has been observed in a temperature range relevant for measurements of the charge carrier mobility in OFET structures. Since the present model is not limited to zero-field mobility, it allows a more accurate evaluation of important material parameters from experimental data measured at a given electric field. In particular, we showed that both the MN and Gill temperature can be used for estimating the width of the density of states distribution.

  20. Energy transfer at gas-liquid interface: Towards energetic materials

    NASA Astrophysics Data System (ADS)

    Szabo, Tamas

    Physicochemical surface processes have great importance in the different fields of everyday life and science. Computational characterization of collisional energy transfer at a gas-liquid interface is a helpful tool to interpret recent experimental studies and to yield insight into the energy feedback mechanism of multiphase combustion problems. As a first step, a simple Lennard-Jones system was used to investigate the dependence of the collisional energy transfer and the gas atom trapping probabilities on the temperature of the bulk liquid, on the gas/liquid particle mass ratios, on the incident angle of the impinging projectile, and on the gas-liquid interaction strength. We find in accord with the experimental results that the kinematic effects dominate the energy transfer dynamics, but the importance of the role of surface roughening as the temperature of the liquid increases is also seen. The second system, nitromethane was chosen to extend the range of simulations. It is a molecular model system, representing nitramine-type energetic materials. Having had a good potential description for the nitromethane molecule including all internal degrees of freedom, we generated simplified molecular systems based on the original nitromethane model to isolate particular features of the dynamics. We have investigated the effect of the initial incident energy, of the inclusion of the internal degrees of freedom, of the initial incident kinetic energy and of the gas-surface interaction strength. The incorporation of internal degrees of freedom enhanced the collisional energy transfer. These calculations also point to the importance of simple kinematics as it predicts the increase of the ratio of energy transferred with increased initial incident energy of the gas particle.

  1. Scintillation Efficiency of Liquid Xenon for Low Energy Nuclear Recoils

    NASA Astrophysics Data System (ADS)

    Wongjirad, Taritree; Ni, Kaixuan; Manzur, Angel; Kastens, Louis; McKinsey, Daniel

    2008-04-01

    In early 2006, the XENON and ZEPLIN collaborations announced highly stringent upper limits on the WIMP-nucleon cross-section. However, the dominant systematic uncertainty in these limits is due to the uncertainty in the nuclear recoil scintillation efficiency (NRSE) for liquid xenon. The NRSE is defined as the amount of scintillation produced by nuclear recoils, divided by the amount of scintillation produced by electron recoils, per unit energy. Though the NRSE has been measured by several groups, its value at the low energies most important for the liquid xenon WIMP searches has a large uncertainty. Furthermore, the NRSE may vary with the strength of the electric field in the liquid xenon. In an attempt to reduce these uncertainties, we have measured the NRSE down to 5 keV nuclear recoil energy for various electric fields.

  2. In situ electron energy-loss spectroscopy in liquids.

    PubMed

    Holtz, Megan E; Yu, Yingchao; Gao, Jie; Abruña, Héctor D; Muller, David A

    2013-08-01

    In situ scanning transmission electron microscopy (STEM) through liquids is a promising approach for exploring biological and materials processes. However, options for in situ chemical identification are limited: X-ray analysis is precluded because the liquid cell holder shadows the detector and electron energy-loss spectroscopy (EELS) is degraded by multiple scattering events in thick layers. Here, we explore the limits of EELS in the study of chemical reactions in their native environments in real time and on the nanometer scale. The determination of the local electron density, optical gap, and thickness of the liquid layer by valence EELS is demonstrated. By comparing theoretical and experimental plasmon energies, we find that liquids appear to follow the free-electron model that has been previously established for solids. Signals at energies below the optical gap and plasmon energy of the liquid provide a high signal-to-background ratio regime as demonstrated for LiFePO4 in an aqueous solution. The potential for the use of valence EELS to understand in situ STEM reactions is demonstrated for beam-induced deposition of metallic copper: as copper clusters grow, EELS develops low-loss peaks corresponding to metallic copper. From these techniques, in situ imaging and valence EELS offer insights into the local electronic structure of nanoparticles and chemical reactions. PMID:23721691

  3. Modelling temperature and concentration dependent solid/liquid interfacial energies

    NASA Astrophysics Data System (ADS)

    Lippmann, Stephanie; Jung, In-Ho; Paliwal, Manas; Rettenmayr, Markus

    2016-01-01

    Models for the prediction of the solid/liquid interfacial energy in pure substances and binary alloys, respectively, are reviewed and extended regarding the temperature and concentration dependence of the required thermodynamic entities. A CALPHAD-type thermodynamic database is used to introduce temperature and concentration dependent melting enthalpies and entropies for multicomponent alloys in the temperature range between liquidus and solidus. Several suitable models are extended and employed to calculate the temperature and concentration dependent interfacial energy for Al-FCC with their respective liquids and compared with experimental data.

  4. Low-energy scattering of electrons and positrons in liquids

    NASA Technical Reports Server (NTRS)

    Schrader, D. M.

    1990-01-01

    The scattering of low energy electrons and positrons is described for the liquid phase and compared and contrasted with that for the gas phase. Similarities as well as differences are noted. The loci of scattering sites, called spurs in the liquid phase, are considered in detail. In particular, their temporal and spatial evolution is considered from the point of view of scattering. Two emphases are made: one upon the stochastic calculation of the distribution of distances required for slowing down to thermal velocities, and the other upon the calculation of cross sections for energy loss by means of quantum mechanics.

  5. Mesoporous silica nanoparticles synthesized from liquid crystal display manufacturing extracts as a potential candidate for a drug delivery carrier: evaluation of their safety and biocompatibility

    PubMed Central

    Lin, Yu-chih; Lin, Liang-Yi; Gao, Ming-Yi; Fang, Yi-Ping

    2013-01-01

    Mesoporous silica nanoparticles (MSNs) were synthesized as a promising drug delivery carrier due to the large surface area and porous characteristics. Our previous study successfully recycled wastes from the liquid crystal display (LCD) industry as the silica precursor. In this study, we substantiated the possibility of applying this material as a drug carrier. MSNs synthesized from the extraction of wastes from the manufacture of LCD panels were characterized as having an average diameter of 100 nm, a surface area of 788 m2/g, a uniform pore size distribution of 3.8 nm, and a pore volume of up to 1.04 cm3/g. Methotrexate and camptothecin were entrapped in MSNs at about 33.88% and 75.12%, respectively. The cell viability assay demonstrated that MSNs at 1 μg/mL had no significant influence on human lung fibroblast (WI-38) cells or ovarian cancer (ES-2) cells. A lactate dehydrogenase assay also indicated no inflammation occurred. Moreover, a hemolytic erythrocyte test indicated that the dose range of <100 μg/mL showed that 5% of erythrocytes were affected. After exposure to biofluids, the ordered structure was slightly degraded. The results revealed that MSNs synthesized from extraction of wastes from the manufacture of LCD panels had a good entrapment capacity for hydrophobic drugs and controllable safety conditions; they may be applied as a drug delivery carrier. PMID:24143088

  6. Use of alternative carrier materials in AOAC Official Method 2008.05, efficacy of liquid sporicides against spores of Bacillus subtilis on a hard, nonporous surface, quantitative three-step method.

    PubMed

    Tomasino, Stephen F; Rastogi, Vipin K; Wallace, Lalena; Smith, Lisa S; Hamilton, Martin A; Pines, Rebecca M

    2010-01-01

    The quantitative Three-Step Method (TSM) for testing the efficacy of liquid sporicides against spores of Bacillus subtilis on a hard, nonporous surface (glass) was adopted as AOAC Official Method 2008.05 in May 2008. The TSM uses 5 x 5 x 1 mm coupons (carriers) upon which spores have been inoculated and which are introduced into liquid sporicidal agent contained in a microcentrifuge tube. Following exposure of inoculated carriers and neutralization, spores are removed from carriers in three fractions (gentle washing, fraction A; sonication, fraction B; and gentle agitation, fraction C). Liquid from each fraction is serially diluted and plated on a recovery medium for spore enumeration. The counts are summed over the three fractions to provide the density (viable spores per carrier), which is log10-transformed to arrive at the log density. The log reduction is calculated by subtracting the mean log density for treated carriers from the mean log density for control carriers. This paper presents a single-laboratory investigation conducted to evaluate the applicability of using two porous carrier materials (ceramic tile and untreated pine wood) and one alternative nonporous material (stainless steel). Glass carriers were included in the study as the reference material. Inoculated carriers were evaluated against three commercially available liquid sporicides (sodium hypochlorite, a combination of peracetic acid and hydrogen peroxide, and glutaraldehyde), each at two levels of presumed efficacy (medium and high) to provide data for assessing the responsiveness of the TSM. Three coupons of each material were evaluated across three replications at each level; three replications of a control were required. Even though all carriers were inoculated with approximately the same number of spores, the observed counts of recovered spores were consistently higher for the nonporous carriers. For control carriers, the mean log densities for the four materials ranged from 6.63 for

  7. Binding energies and spatial structures of small carrier complexes in monolayer transition-metal dichalcogenides via diffusion Monte Carlo

    DOE PAGESBeta

    Mayers, Matthew Z.; Berkelbach, Timothy C.; Hybertsen, Mark S.; Reichman, David R.

    2015-10-09

    Ground-state diffusion Monte Carlo is used to investigate the binding energies and intercarrier radial probability distributions of excitons, trions, and biexcitons in a variety of two-dimensional transition-metal dichalcogenide materials. We compare these results to approximate variational calculations, as well as to analogous Monte Carlo calculations performed with simplified carrier interaction potentials. Our results highlight the successes and failures of approximate approaches as well as the physical features that determine the stability of small carrier complexes in monolayer transition-metal dichalcogenide materials. In conclusion, we discuss points of agreement and disagreement with recent experiments.

  8. Determination of monoamine neurotransmitters in human urine by carrier-mediated liquid-phase microextraction based on solidification of stripping phase.

    PubMed

    Jiang, Liwei; Chen, Yibang; Chen, Yejun; Ma, Ming; Tan, Yueming; Tang, Hao; Chen, Bo

    2015-11-01

    A novel method was developed for the analysis of monoamine neurotransmitters (MNTs) in human urine by carrier-mediated liquid-phase microextraction based on solidification of stripping phase method (CM-LPME-SSP) coupled with high performance liquid chromatography-electrochemical detector (HPLC-ECD). By adding an appropriate carrier in organic phase, simultaneous extraction of hydrophilic analytes, MNTs, with high enrichment factors (22.6-36.1 folds) and excellent sample cleanup was achieved. A new strategy, solidifying the aqueous stripping phase in the back-extraction process, was developed to facilitate the collection of the stripping phase as small as a few microliters. Combined with HPLC-ECD analysis, the linear ranges of the established method were 0.015-2.0 μg/mL for NE, E, DA, and 0.020-2.0 μg/mL for 5-HT. The limits of detection and quantification were in the range of 5.5-10.8 ng/mL and 15-20 ng/mL, respectively. The relative recoveries were in the range of 87-108%, with intraday and interday relative standard deviations lower than 13%. This method was successfully applied to analysis of MNTs in real urine. PMID:26452833

  9. Pressure-energy correlations in liquids. IV. ``Isomorphs'' in liquid phase diagrams

    NASA Astrophysics Data System (ADS)

    Gnan, Nicoletta; Schrøder, Thomas B.; Pedersen, Ulf R.; Bailey, Nicholas P.; Dyre, Jeppe C.

    2009-12-01

    This paper is the fourth in a series devoted to identifying and explaining the properties of strongly correlating liquids, i.e., liquids where virial and potential energy correlate better than 90% in their thermal equilibrium fluctuations in the N V T ensemble. For such liquids we here introduce the concept of "isomorphic" curves in the phase diagram. A number of thermodynamic, static, and dynamic isomorph invariants are identified. These include the excess entropy, the isochoric specific heat, reduced-unit static and dynamic correlation functions, as well as reduced-unit transport coefficients. The dynamic invariants apply for both Newtonian and Brownian dynamics. It is shown that after a jump between isomorphic state points the system is instantaneously in thermal equilibrium; consequences of this for generic aging experiments are discussed. Selected isomorph predictions are validated by computer simulations of the Kob-Andersen binary Lennard-Jones mixture, which is a strongly correlating liquid. The final section of the paper relates the isomorph concept to phenomenological melting rules, Rosenfeld's excess entropy scaling, Young and Andersen's approximate scaling principle, and the two-order parameter maps of Debenedetti and co-workers. This section also shows how the existence of isomorphs implies an "isomorph filter" for theories for the non-Arrhenius temperature dependence of viscous liquids' relaxation time, and it explains isochronal superposition for strongly correlating viscous liquids.

  10. Separation of alkali, alkaline earth and rare earth cations by liquid membranes containing macrocyclic carriers. Third progress report, September 1, 1980-April 1, 1981

    SciTech Connect

    Christensen, J.J.

    1981-04-15

    The overall objective of this project is to study the use of liquid membrane systems employing macrocyclic ligand carriers in making separations among metal cations. During the third year of the project, work continued in the development of a mathematical model to describe cation transport. The model was originally developed to describe the relationship between cation transport rate (J/sub M/) and the cation-macrocycle stability constant (K). The model was tested by determining the rates of transport of alkali and alkaline earth cations through chloroform membranes containing carrier ligands where the stability constants for their reaction with cations in methanol were known. From the results, it is clear that the model correctly describes the dependence of J/sub M/ on log K. The model also correctly describes the effect of cation concentration and carrier concentration on cation transport rates, as detailed in the previous progress report. During the third year of the project, the transport model was expanded so as to apply to competitive transport of cations from mixtures of two cations in the source aqueous phase. Data were collected under these conditions and the ability of the model to predict the flux of each cation was tested. Representative data of this type are presented along with corresponding data which were obtained when each cation was transported by the same carrier from a source phase containing only that cation. Comparison of transport rates determined under the two experimental conditions indicates that the relationship between the two sets of data is complex. To date, a few of these data involving transport from binary cation mixtures have been tested against the transport model. It was found that the model correctly predicts the cation fluxes from cation mixtures. These preliminary results indicate that the transport model can successfully predict separation factors when cation mixtures are used.

  11. Hydrogen Peroxide as a Sustainable Energy Carrier: Electrocatalytic Production of Hydrogen Peroxide and the Fuel Cell

    PubMed Central

    Fukuzumi, Shunichi; Yamada, Yusuke; Karlin, Kenneth D.

    2012-01-01

    This review describes homogeneous and heterogeneous catalytic reduction of dioxygen with metal complexes focusing on the catalytic two-electron reduction of dioxygen to produce hydrogen peroxide. Whether two-electron reduction of dioxygen to produce hydrogen peroxide or four-electron O2-reduction to produce water occurs depends on the types of metals and ligands that are utilized. Those factors controlling the two processes are discussed in terms of metal-oxygen intermediates involved in the catalysis. Metal complexes acting as catalysts for selective two-electron reduction of oxygen can be utilized as metal complex-modified electrodes in the electrocatalytic reduction to produce hydrogen peroxide. Hydrogen peroxide thus produced can be used as a fuel in a hydrogen peroxide fuel cell. A hydrogen peroxide fuel cell can be operated with a one-compartment structure without a membrane, which is certainly more promising for the development of low-cost fuel cells as compared with two compartment hydrogen fuel cells that require membranes. Hydrogen peroxide is regarded as an environmentally benign energy carrier because it can be produced by the electrocatalytic two-electron reduction of O2, which is abundant in air, using solar cells; the hydrogen peroxide thus produced could then be readily stored and then used as needed to generate electricity through the use of hydrogen peroxide fuel cells. PMID:23457415

  12. Thermally driven electrokinetic energy conversion with liquid water microjets

    NASA Astrophysics Data System (ADS)

    Lam, Royce K.; Gamlieli, Zach; Harris, Stephen J.; Saykally, Richard J.

    2015-11-01

    A goal of current energy research is to design systems and devices that can efficiently exploit waste heat and utilize solar or geothermal heat energy for electrical power generation. We demonstrate a novel technique exploiting water's large coefficient of thermal expansion, wherein modest thermal gradients produce the requisite high pressure for driving fast-flowing liquid water microjets, which can effect the direct conversion of the kinetic energy into electricity and gaseous hydrogen. Waste heat in thermoelectric generating plants and combustion engines, as well as solar and geothermal energy could be used to drive these systems.

  13. Agro-industry sugarcane residues disposal: the trends of their conversion into energy carriers in Cuba.

    PubMed

    Alonso Pippo, W; Garzone, P; Cornacchia, G

    2007-01-01

    The goal of the present work was to carry out a review of the disposal practices for the agro-industry's sugarcane residue and the trends of energy use in Cuba. The lack of an alternative energy carrier to electricity with storage capability for use in off-season has to date been an unsolvable question. The improvement of cogeneration capacity via implementation of CEST or BIG/GTCC and the barriers for their implementation, the introduction of a medium size (3 ton/h) fast pyrolysis module (FPM3) as a solution for off-season energy demand in the agro-industry, and an assessment of the energy required to do so, were also analyzed. Bio-oil production from bagasse and sugarcane agriculture residues (SCAR) and their particularities at the sugar mill are treated. The influence of sugar facility production process configuration is analyzed. The fast pyrolysis products and the trends of their end uses in Cuba are presented. The production cost of a ton of Bio-oil for FPM3 conditions was calculated at 155 USD/ton and the payback time as a function of selling price between 160 and 110 USD/ton was estimated to be from 1.5 to 4 years. The economic feasibility of the FPM3 was estimated, comparing the added values for three scenarios: 1st case, currently-used sugar production, 16.5 USD/ton of cane; 2nd case, factoring in the cogeneration improvement, 27 USD/ton of cane; and 3rd case, with cogeneration improvement and Bio-oil production, 40 USD/ton of cane. The energy use of SCAR and the introduction of FPM3 in the sugar mill are promising improvements that could result in a potential surplus of 80 kWh(e)/ton of cane in-season, or 6 x 10(6)ton of Bio-oil (LHV=15 MJ/kg) for use off-season in a milling season of 4 million tons of raw sugar. PMID:16797957

  14. Magnetic particles as liquid carriers in the microfluidic lab-in-tube approach to detect phase change.

    PubMed

    Blumenschein, Nicholas A; Han, Daewoo; Caggioni, Marco; Steckl, Andrew J

    2014-06-11

    Magnetic beads (MBs) with ∼1.9 μm average diameter were used to transport specific microliter-scale volumes of liquids between adjacent reservoirs within a closed tube under the influence of a magnetic field. The tube's inner surface is coated with a hydrophobic layer, enabling the formation of a surface tension valve by inserting an air gap between reservoirs. This transfer process was implemented by keeping the MBs stationary with a fixed external magnet while the liquid reservoirs were translated by a computer-controlled syringe pump system. The magnet induces the aggregation of MBs in a loosely packed cluster (void volume ∼90-95%) against the tube's inner wall. The liquid trapped in the MB cluster is transported across the air gap between reservoirs. Fluorescence intensity from a dye placed in one reservoir is used to measure the volume of liquid transferred between reservoirs. The carry-over liquid volume is controlled by the mass of the MBs within the device. The typical volume of liquid carried by the MB cluster is ∼2 to 3 μL/mg of beads, allowing the use of small samples. This technique can be used to study the effect of small compositional variation on the properties of fluid mixtures. The feasibility of this "lab-in-tube" approach for binary phase diagram determination in a water-surfactant (C12E5) system was demonstrated. PMID:24827028

  15. Regulating energy transfer of excited carriers and the case for excitation-induced hydrogen dissociation on hydrogenated graphene

    PubMed Central

    Bang, Junhyeok; Meng, Sheng; Sun, Yi-Yang; West, Damien; Wang, Zhiguo; Gao, Fei; Zhang, S. B.

    2013-01-01

    Understanding and controlling of excited carrier dynamics is of fundamental and practical importance, particularly in photochemistry and solar energy applications. However, theory of energy relaxation of excited carriers is still in its early stage. Here, using ab initio molecular dynamics (MD) coupled with time-dependent density functional theory, we show a coverage-dependent energy transfer of photoexcited carriers in hydrogenated graphene, giving rise to distinctively different ion dynamics. Graphene with sparsely populated H is difficult to dissociate due to inefficient transfer of the excitation energy into kinetic energy of the H. In contrast, H can easily desorb from fully hydrogenated graphane. The key is to bring down the H antibonding state to the conduction band minimum as the band gap increases. These results can be contrasted to those of standard ground-state MD that predict H in the sparse case should be much less stable than that in fully hydrogenated graphane. Our findings thus signify the importance of carrying out explicit electronic dynamics in excited-state simulations. PMID:23277576

  16. Regulating energy transfer of excited carriers and the case for excitation-induced hydrogen dissociation on hydrogenated graphene

    SciTech Connect

    Bang, Junhyeok; Meng, Sheng; Sun, Yi-Yang; West, Damien; Wang, Zhiguo; Gao, Fei; Zhang, Shengbai

    2013-01-15

    Understanding and controlling of excited carrier dynamics is of fundamental and practical importance, particularly in photochemistry and solar energy applications. However, theory of energy relaxation of excited carriers is still in its early stage. Here, using ab-initio molecular dynamics (MD) coupled with time-dependent density functional theory, we show a coverage-dependent energy transfer of photoexcited carriers in hydrogenated graphene, giving rise to distinctively different ion dynamics. Graphene with sparsely populated H is difficult to dissociate due to inefficient transfer of the excitation energy into kinetic energy of the H. In contrast, H can easily desorb from fully hydrogenated graphane. The key is to bring down the H antibonding state to the conduction band minimum as the band gap increases. These results can be contrasted to those of standard ground-state MD which predicts H in the sparse case should be much less stable than that in fully hydrogenated graphane. Our findings thus signify the importance of carrying out explicit electronic dynamics in excited-state simulations.

  17. Ionic liquid-based green processes for energy production.

    PubMed

    Zhang, Suojiang; Sun, Jian; Zhang, Xiaochun; Xin, Jiayu; Miao, Qingqing; Wang, Jianji

    2014-11-21

    To mitigate the growing pressure on resource depletion and environment degradation, the development of green processes for the production of renewable energy is highly required. As a class of novel and promising media, ionic liquids (ILs) have shown infusive potential applications in energy production. Aiming to offer a critical overview regarding the new challenges and opportunities of ILs for developing green processes of renewable energy, this article emphasises the role of ILs as catalysts, solvents, or electrolytes in three broadly interesting energy production processes from renewable resources, such as CO2 conversion to fuels and fuel additives, biomass pretreatment and conversion to biofuels, as well as solar energy and energy storage. It is expected that this article will stimulate a generation of new ideas and new technologies in IL-based renewable energy production. PMID:24553494

  18. Terahertz absorption spectra and potential energy distribution of liquid crystals.

    PubMed

    Chen, Zezhang; Jiang, Yurong; Jiang, Lulu; Ma, Heng

    2016-01-15

    In this work, the terahertz (THz) absorption spectra of a set of nematic liquid crystals were studied using the density functional theories (DFT). An accurate assignment of the vibrational modes corresponding to absorption frequencies were performed using potential energy distribution (PED) in a frequency range of 0-3 THz. The impacts of different core structures on THz absorption spectra were discussed. The results indicate that scope of application must be considered in the LC-based THz device designing. This proposed work may give a useful suggestion on the design of novel liquid crystal material in THz wave. PMID:26476072

  19. Probing battery chemistry with liquid cell electron energy loss spectroscopy

    SciTech Connect

    Unocic, Raymond R.; Baggetto, Loic; Veith, Gabriel M.; Unocic, Kinga A.; Sacci, Robert L.; Dudney, Nancy J.; More, Karren Leslie; Aguiar, Jeffery A.

    2015-09-15

    Electron energy loss spectroscopy (EELS) was used to determine the chemistry and oxidation state of LiMn2O4 and Li4Ti5O12 thin film battery electrodes in liquid cells for in situ scanning/transmission electron microscopy (S/TEM). Using the L2,3 white line intensity ratio method we determine the oxidation state of Mn and Ti in a liquid electrolyte solvent and discuss experimental parameters that influence measurement sensitivity.

  20. Bosonization of the low energy excitations of Fermi liquids

    SciTech Connect

    Castro Neto, A.H.; Fradkin, E. )

    1994-03-07

    We bosonize the low energy excitations of Fermi liquids in any number of dimensions in the limit of long wavelengths. The bosons are a coherent superposition of electron-hole pairs and are related with the displacements of the Fermi surface in some arbitrary direction. A coherent-state path integral for the bosonized theory is derived and it is shown to represent histories of the shape of the Fermi surface. The Landau theory of Fermi liquids can be obtained from the formalism in the absence of nesting of the Fermi surface and singular interactions. We show that the Landau equation for sound waves is exact in the semiclassical approximation for the bosons.

  1. Why are ionic liquids liquid? A simple explanation based on lattice and solvation energies.

    PubMed

    Krossing, Ingo; Slattery, John M; Daguenet, Corinne; Dyson, Paul J; Oleinikova, Alla; Weingärtner, Hermann

    2006-10-18

    We have developed a simple and quantitative explanation for the relatively low melting temperatures of ionic liquids (ILs). The basic concept was to assess the Gibbs free energy of fusion (Delta(fus)G) for the process IL(s) --> IL(l), which relates to the melting point of the IL. This was done using a suitable Born-Fajans-Haber cycle that was closed by the lattice (i.e., IL(s) --> IL(g)) Gibbs energy and the solvation (i.e., IL(g) --> IL(l)) Gibbs energies of the constituent ions in the molten salt. As part of this project we synthesized and determined accurate melting points (by DSC) and dielectric constants (by dielectric spectroscopy) for 14 ionic liquids based on four common anions and nine common cations. Lattice free energies (Delta(latt)G) were estimated using a combination of Volume Based Thermodynamics (VBT) and quantum chemical calculations. Free energies of solvation (Delta(solv)G) of each ion in the bulk molten salt were calculated using the COSMO solvation model and the experimental dielectric constants. Under standard ambient conditions (298.15 K and 10(5) Pa) Delta(fus)G degrees was found to be negative for all the ILs studied, as expected for liquid samples. Thus, these ILs are liquid under standard ambient conditions because the liquid state is thermodynamically favorable, due to the large size and conformational flexibility of the ions involved, which leads to small lattice enthalpies and large entropy changes that favor melting. This model can be used to predict the melting temperatures and dielectric constants of ILs with good accuracy. A comparison of the predicted vs experimental melting points for nine of the ILs (excluding those where no melting transition was observed and two outliers that were not well described by the model) gave a standard error of the estimate (s(est)) of 8 degrees C. A similar comparison for dielectric constant predictions gave s(est) as 2.5 units. Thus, from very little experimental and computational data it is

  2. Crystal-liquid interfacial free energy via thermodynamic integration

    SciTech Connect

    Benjamin, Ronald; Horbach, Jürgen

    2014-07-28

    A novel thermodynamic integration (TI) scheme is presented to compute the crystal-liquid interfacial free energy (γ{sub cl}) from molecular dynamics simulation. The scheme is applied to a Lennard-Jones system. By using extremely short-ranged and impenetrable Gaussian flat walls to confine the liquid and crystal phases, we overcome hysteresis problems of previous TI schemes that stem from the translational movement of the crystal-liquid interface. Our technique is applied to compute γ{sub cl} for the (100), (110), and (111) orientation of the crystalline phase at three temperatures under coexistence conditions. For one case, namely, the (100) interface at the temperature T = 1.0 (in reduced units), we demonstrate that finite-size scaling in the framework of capillary wave theory can be used to estimate γ{sub cl} in the thermodynamic limit. Thereby, we show that our TI scheme is not associated with the suppression of capillary wave fluctuations.

  3. Asymmetric energy flow in liquid alkylbenzenes: A computational study

    SciTech Connect

    Leitner, David M.; Pandey, Hari Datt

    2015-10-14

    Ultrafast IR-Raman experiments on substituted benzenes [B. C. Pein et al., J. Phys. Chem. B 117, 10898–10904 (2013)] reveal that energy can flow more efficiently in one direction along a molecule than in others. We carry out a computational study of energy flow in the three alkyl benzenes, toluene, isopropylbenzene, and t-butylbenzene, studied in these experiments, and find an asymmetry in the flow of vibrational energy between the two chemical groups of the molecule due to quantum mechanical vibrational relaxation bottlenecks, which give rise to a preferred direction of energy flow. We compare energy flow computed for all modes of the three alkylbenzenes over the relaxation time into the liquid with energy flow through the subset of modes monitored in the time-resolved Raman experiments and find qualitatively similar results when using the subset compared to all the modes.

  4. Real-Space Visualization of Energy Loss and Carrier Diffusion in a Semiconductor Nanowire Array Using 4D Electron Microscopy.

    PubMed

    Bose, Riya; Sun, Jingya; Khan, Jafar I; Shaheen, Basamat S; Adhikari, Aniruddha; Ng, Tien Khee; Burlakov, Victor M; Parida, Manas R; Priante, Davide; Goriely, Alain; Ooi, Boon S; Bakr, Osman M; Mohammed, Omar F

    2016-07-01

    A breakthrough in the development of 4D scanning ultrafast electron microscopy is described for real-time and space imaging of secondary electron energy loss and carrier diffusion on the surface of an array of nanowires as a model system, providing access to a territory that is beyond the reach of either static electron imaging or any time-resolved laser spectroscopy. PMID:27111855

  5. Grism compressor for carrier-envelope phase-stable millijoule-energy chirped pulse amplifier lasers featuring bulk material stretcher.

    PubMed

    Ricci, A; Jullien, A; Forget, N; Crozatier, V; Tournois, P; Lopez-Martens, R

    2012-04-01

    We demonstrate compression of amplified carrier-envelope phase (CEP)-stable laser pulses using paired transmission gratings and high-index prisms, or grisms, with chromatic dispersion matching that of a bulk material pulse stretcher. Grisms enable the use of larger bulk stretching factors and thereby higher energy pulses with lower B-integral in a compact amplifier design suitable for long-term CEP control. PMID:22466193

  6. Recovery of synthetic dye from simulated wastewater using emulsion liquid membrane process containing tri-dodecyl amine as a mobile carrier.

    PubMed

    Othman, N; Zailani, S N; Mili, N

    2011-12-30

    The extraction of Red 3BS reactive dye from aqueous solution was studied using emulsion liquid membrane (ELM). ELM is one of the processes that have very high potential in treating industrial wastewater consisting of dyes. In this research, Red 3BS reactive dye was extracted from simulated wastewater using tridodecylamine (TDA) as the carrier agent, salicyclic acid (SA) to protonate TDA, sodium chloride as the stripping agent, kerosene as the diluent and SPAN 80 as emulsifier. Experimental parameters investigated were salicyclic acid concentration, extraction time, SPAN 80 concentration, sodium chloride concentration, TDA concentration, agitation speed, homogenizer speed, emulsifying time and treat ratio. The results show almost 100% of Red 3BS was removed and stripped in the receiving phase at the optimum condition in this ELM system. High voltage coalesce was applied to break the emulsion hence, enables recovery of Red 3BS in the receiving phase. PMID:22023906

  7. The mechanism of proline/glutamate antiport in rat kidney mitochondria. Energy dependence and glutamate-carrier involvement.

    PubMed

    Atlante, A; Passarella, S; Pierro, P; Di Martino, C; Quagliariello, E

    1996-10-01

    Proline/glutamate antiport in rat kidney mitochondria has been studied in terms of two different features: energy dependence and glutamate-carrier contribution to accomplish proline movement across the mitochondrial membrane. Energy dependence of the proline/glutamate antiporter in rat kidney mitochondria has been investigated by means of both spectroscopic measurements and isotopic techniques, using either normal or [14C]glutamate-loaded mitochondria. The sensitivity of the proline/glutamate antiport to the ionophores valinomycin and nigericin, under conditions in which delta psi and delta pH are selectively affected, shows that the exchange is energy dependent. Measurements of both membrane potential and proton movement across the mitochondrial membrane suggest that proline/glutamate antiport is driven by the electrochemical proton gradient via the delta psi dependent proline/glutamate translocator and delta pH-dependent glutamate/OH- carrier. Such a carrier provides for re-uptake of glutamate that has already passed out of the mitochondria in exchange with incoming proline, made possible by the existence of a separate pool of glutamate in the intermembrane space, directly shown by means of HPLC measurements. PMID:8898903

  8. Harvesting human kinematical energy based on liquid metal magnetohydrodynamics

    NASA Astrophysics Data System (ADS)

    Jia, Dewei; Liu, Jing; Zhou, Yixin

    2009-03-01

    A flexible human energy harvesting generator - Liquid Metal Magnetohydrodynamics Generator (LMMG) is proposed and fabricated. Conceptual experiments were performed to investigate this electricity harvesting principle. Theoretical analysis predicts that the present method is promising at converting otherwise wasted human kinematical energy via a directional selective generation paradigm. In vitro experiment demonstrates output of 1.4 V/3.61 μW by 5.68 g Ga 62In 25Sn 13 liquid metal with a rather high efficiency of more than 45%. The in vivo experiment actuated by a wrist swing during brisk walking with the plastic valve to rectify the flow, verified the potentiality of unidirectional actuation. This concept based on the flexible movement of LMMG is robust to supply electricity which would be important for future wearable micro/nano devices as a voltage constrained charge provider.

  9. Determination of charge carrier concentration in doped nonpolar liquids by impedance spectroscopy in the presence of charge adsorption.

    PubMed

    Yezer, Benjamin A; Khair, Aditya S; Sides, Paul J; Prieve, Dennis C

    2016-05-01

    The impedance of dodecane doped with sorbitan trioleate (Span 85), sorbitan monooleate (Span 80) and sorbitan monolaurate (Span 20) was measured as a function of frequency using a 10mV amplitude sinusoidal voltage applied across a parallel plate cell with a 10μm spacing. The tested solutions varied in concentration from 1mM to 100mM and the frequency range was 10(-2)-10(4)Hz. Nyquist plots of all three surfactants showed the high frequency semicircle characteristic of parallel resistance and capacitance but often exhibited a second semicircle at low frequencies which was attributed to charge adsorption and desorption. The electrical conductivity of each surfactant was proportional to surfactant concentration for concentrations above 10mM. Fitting the data to models for charge migration, differential capacitance, and adsorption allowed extraction of both charge concentration and two kinetic parameters that characterize the rate of adsorption and desorption. Above 10mM the ratio of charge carriers per surfactant molecule was 22ppm for Span 20, 3ppm for Span 80, and 0.2ppm for Span 85. A higher number of charge carriers per molecule of surfactant was associated with larger micelles. The adsorption rate constants were independent of surfactant concentration while the desorption rate constants were proportional to the surfactant concentration. This dependence indicated that uncharged surfactant, whether in micelles or not, participated in the desorption of charge. Predictions of the adsorption/desorption model for large constant electric fields agreed qualitatively with data from the literature (Karvar et al., 2014). PMID:26905337

  10. Silicon quantum dots in SiOx dielectrics as energy selective contacts in hot carrier solar cells

    NASA Astrophysics Data System (ADS)

    Kar, Debjit; Das, Debajyoti

    2015-06-01

    Thin films of c-Si QDs embedded in a-SiOx dielectric matrix was achieved at a low temperature ˜400°C, from one step process by reactive rf magnetron co-sputtering of c-Si wafer and pure SiO2 targets, in the (H2+Ar)- plasma. Formation of a double-barrier structure has been primarily identified from the SAX data and exclusively confirmed from the resonant tunneling current appearing in the J-E characteristic curve peaks, determined by the discrete energy levels of c-Si QDs, at which it could be used as energy selective contacts in hot carrier solar cells.

  11. Cr(VI) transport via a supported ionic liquid membrane containing CYPHOS IL101 as carrier: system analysis and optimization through experimental design strategies.

    PubMed

    Rodríguez de San Miguel, Eduardo; Vital, Xóchitl; de Gyves, Josefina

    2014-05-30

    Chromium(VI) transport through a supported liquid membrane (SLM) system containing the commercial ionic liquid CYPHOS IL101 as carrier was studied. A reducing stripping phase was used as a mean to increase recovery and to simultaneously transform Cr(VI) into a less toxic residue for disposal or reuse. General functions which describe the time-depending evolution of the metal fractions in the cell compartments were defined and used in data evaluation. An experimental design strategy, using factorial and central-composite design matrices, was applied to assess the influence of the extractant, NaOH and citrate concentrations in the different phases, while a desirability function scheme allowed the synchronized optimization of depletion and recovery of the analyte. The mechanism for chromium permeation was analyzed and discussed to contribute to the understanding of the transfer process. The influence of metal concentration was evaluated as well. The presence of different interfering ions (Ca(2+), Al(3+), NO3(-), SO4(2-), and Cl(-)) at several Cr(VI): interfering ion ratios was studied through the use of a Plackett and Burman experimental design matrix. Under optimized conditions 90% of recovery was obtained from a feed solution containing 7mgL(-1) of Cr(VI) in 0.01moldm(-3) HCl medium after 5h of pertraction. PMID:24751491

  12. Low-energy recoils and energy scale in liquid xenon detector for direct dark matter searches

    NASA Astrophysics Data System (ADS)

    Wang, Lu; Mei, Dongming; Cubed Collaboration

    2015-04-01

    Liquid xenon has been proven to be a great detector medium for the direct search of dark matter. However, in the energy region of below 10 keV, the light yield and charge production are not fully understood due to the convolution of excitation, recombination and quenching. We have already studied a recombination model to explain the physics processes involved in liquid xenon. Work is continued on the average energy expended per electron-ion pair as a function of energy based on the cross sections for different type of scattering processes. In this paper, the results will be discussed in comparison with available experimental data using Birk's Law to understand how scintillation quenching contributes to the non-linear light yield for electron recoils with energy below 10 keV in liquid xenon. This work is supported by DOE Grant DE-FG02-10ER46709 and the state of South Dakota.

  13. Liquid madelung energy and schottky defect energy related to liquid structure and melting temperature for alkali halides

    SciTech Connect

    March, N.H.; Tosi, M.P.

    1985-01-01

    Motivated by the work of Reiss et al. in which the melting temperature T /SUB m/ of alkali halides is correlated with Coulomb energy, we consider the cohesive energy W of ionic melts and Schottky defect energy E /SUB s/ in the hot crystal, relative to the thermal energy k /SUB B/ T /SUB m/ . It is shown here that is accurately approximated by the liquid Madelung energy and hence that W/k /SUB B/ T /SUB m/ relates to the charge-charg direct correlation function c /SUB QQ/ (r) at r = 0. The existence of a ''Madelung constant'' for the liquid at T /SUB m/ is thereby demonstrated through the alkali halide series. An estimate of the ratio E /SUB s/ /k /SUB B/ T /SUB m/ i then considered; the basic additional ingredient being argued to be the static dielectric constant of the solid. Th BarrDawson-Lidiard empirical correlation between E /SUB s/ and k /SUB B/ T /SUB m/ can be understood in this way.

  14. Evaluation of Two Ionic Liquid-Based Epoxies from the MISSE-8 (Materials International Space Station Experiment-8) Sample Carrier

    NASA Technical Reports Server (NTRS)

    Rabenberg, Ellen; Kaukler, William; Grugel, Richard

    2015-01-01

    Two sets of epoxy mixtures, both containing the same ionic liquid (IL) based resin but utilizing two different curing agents, were evaluated after spending more than two years of continual space exposure outside of the International Space Station on the MISSE-8 sample rack. During this period the samples, positioned on nadir side, also experienced some 12,500 thermal cycles between approximately -40?C and +40 C. Initial examination showed some color change, a miniscule weight variance, and no cracks or de-bonding from the sample substrate. Microscopic examination of the surface reveled some slight deformities and pitting. These observations, and others, are discussed in view of the ground-based control samples. Finally, the impetus of this study in terms of space applications is presented.

  15. Magnesium-Antimony Liquid Metal Battery for Stationary Energy Storage

    SciTech Connect

    Bradwell, DJ; Kim, H; Sirk, AHC; Sadoway, DR

    2012-02-01

    Batteries are an attractive option for grid: scale energy storage applications because of their small footprint and flexible siting. A high-temperature (700 degrees C) magnesium antimony (MgllSb) liquid metal battery comprising a negative electrode of Mg, a molten salt electrolyte (MgCL2-KCl-NaCl), and a positive electrode of Sb is proposed and characterized. Because of the immiscibility of the contiguous salt and metal phases, they stratify by density into three distinct layers. Cells were cycled at rates ranging from 50 to 200 mA/cm(2) and demonstrated up to 69% DC-DC energy efficiency. The self-segregating nature of the battery components and the use Of low-cost materials results in a promising technology for stationary energy storage applications.

  16. Anomalous vacuum energy and stability of a quantum liquid.

    PubMed

    Trachenko, K; Brazhkin, V V

    2016-03-31

    We show that the vacuum (zero-point) energy of a low-temperature quantum liquid is a variable property which changes with the state of the system, in notable contrast to the static vacuum energy in solids commonly considered. We further show that this energy is inherently anomalous: it decreases with temperature and gives a negative contribution to a system's heat capacity. This effect operates in an equilibrium and macroscopic system, in marked contrast to small or out-of-equilibrium configurations discussed previously. We find that the negative contribution is over-compensated by the positive term from the excitation of longitudinal fluctuations and demonstrate how the overall positive heat capacity is related to the stability of a condensed phase at the microscopic level. PMID:26909505

  17. Excitation energy after a smooth quench in a Luttinger liquid

    SciTech Connect

    Dziarmaga, Jacek; Tylutki, Marek

    2011-12-01

    Low-energy physics of quasi-one-dimensional ultracold atomic gases is often described by a gapless Luttinger liquid (LL). It is nowadays routine to manipulate these systems by changing their parameters in time but, no matter how slow the manipulation is, it must excite a gapless system. We study a smooth change of parameters of the LL (a smooth ''quench'') with a variable quench time and find that the excitation energy decays with an inverse power of the quench time. This universal exponent is -2 at zero temperature and -1 for slow enough quenches at finite temperature. The smooth quench does not excite beyond the range of validity of the low-energy LL description.

  18. Charge carrier dynamics and relaxation in (polyethylene oxide-lithium-salt)-based polymer electrolyte containing 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide as ionic liquid.

    PubMed

    Karmakar, A; Ghosh, A

    2011-11-01

    In this paper we report the dynamics of charge carriers and relaxation in polymer electrolytes based on polyethylene oxide (PEO), lithium bis(trifluoromethylsulfonyl)imide (LiTFSI) and 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMPTFSI) ionic liquid prepared by solution cast technique. It has been observed that the incorporation of BMPTFSI into PEO-LiTFSI electrolyte is an effective way for increasing the amorphous phase to a large extent. It has also been observed that both the glass transition and melting temperatures decrease with the increase of BMPTFSI concentration. The ionic conductivity of these polymer electrolytes increases with the increase of BMPTFSI concentration. The highest ionic conductivity obtained at 25 °C is ~3×10(-4) S cm(-1) for the electrolyte containing 60 wt % BMPTFSI and ethylene oxide (EO)/Li ratio of 20. The temperature dependence of the dc conductivity and the hopping frequency show Vogel-Tamman-Fulcher type behavior indicating a strong coupling between the ionic and the polymer chain segmental motions. The frequency dependence of the ac conductivity exhibits a power law with an exponent n which decreases with the increase of temperature. The scaling of the ac conductivity indicates that relaxation dynamics of charge carriers follows a common mechanism for all temperatures and BMPTFSI concentrations. We have also presented the electric modulus data which have been analyzed in the framework of a Havriliak-Negami equation and the shape parameters obtained by the analysis show slight temperature dependence, but change sharply with BMPTFSI concentration. The stretched exponent β obtained from Kohlrausch-Williams-Watts fit to the modulus data is much lower than unity signifying that the relaxation is highly nonexponential. The decay function obtained from analysis of experimental modulus data is highly asymmetric with time. PMID:22181434

  19. Performance, Defect Behavior and Carrier Enhancement in Low Energy, Proton Irradiated p(+)nn(+) InP Solar Cells

    NASA Technical Reports Server (NTRS)

    Weinberg, I.; Rybicki, G. C.; Vargas-Aburto, C.; Jain, R. K.; Scheiman, D.

    1994-01-01

    InP p(+)nn(+) cells, processed by MOCVD, were irradiated by 0.2 MeV protons and their performance and defect behavior observed to a maximum fluence of 10(exp 13)/sq cm. Their radiation induced degradation, over this fluence range, was considerably+less than observed for similarly irradiated, diffused junction n p InP cells. Significant degradation occurred in both the cell's emitter and base regions the least degradation occurring in the depletion region. A significant increase in series resistance occurs at the highest fluenc.e. Two majority carrier defect levels, E7 and E10, are observed by DLTS with activation energies at (E(sub C) - 0.39)eV and (E(sub C) - 0.74)eV respectively. The relative concentration of these defects differs considerably from that observed after 1 MeV electron irradiation. An increased carrier concentration in the cell's n-region was observed at the highest proton fluence, the change in carrier concentration being insignificant at the lower fluences. In agreement with previous results, for 1 and 1.5 MeV electron irradiated InP p(+)n junctions, the defect level E10 is attributed to a complex between zinc, diffused into the n-region from the zinc doped emitter, and a radiation induced defect. The latter is assumed to be either a phosphorus vacancy or interstitial. The increased, or enhanced carrier concentration is attributed to this complex acting as a donor.

  20. Two-dimensional semimetal in wide HgTe quantum wells: Charge-carrier energy spectrum and magnetotransport

    SciTech Connect

    Germanenko, A. V.; Minkov, G. M.; Rut, O. E.; Sherstobitov, A. A.; Dvoretsky, S. A.; Mikhailov, N. N.

    2013-12-15

    The magnetoresistivity and the Hall and Shubnikov-de Haas effects in heterostructures with a single 20.2-nm-wide quantum well made from the gapless semiconductor HgTe are studied experimentally. The measurements are performed on gated samples over a wide range of electron and hole densities. The data obtained are used to reconstruct the energy spectrum of electrons and holes in the vicinity of the extrema of the quantum-confinement subbands. It is shown that the charge-carrier dispersion relation in the investigated systems differs from that calculated within the framework of the conventional kp model.

  1. The Liquid Fluoride Thorium Reactor: Energy Cheaper Than Coal

    NASA Astrophysics Data System (ADS)

    Stone, Cavan

    2011-11-01

    This century, we face significant environmental challenges. Our demand for limited natural resources is rapidly increasing and much of humanity is concerned about the consequences. Our unsustainably growing population drives these challenges, and humanely stabilizing it would alleviate these pressures. Demographic data clearly shows that prosperity stabilizes population and it also shows that prosperity critically requires energy. In spite of the pressing and demonstrable nature of these challenges however, politically there is no international consensus on global energy policy. Developing nations simply will not accept a policy that will hamper their economic growth. Yet, we do have a solution to these challenges, an idea conceived and experimentally tested by Alvin Weinberg at Oak Ridge National Laboratory, the Liquid Fluoride Thorium Reactor. Presently, various laboratories and start-up companies, including the Chinese Academy of Sciences have begun efforts to commercialize the technology. By delivering the promise of inexpensive energy it will be in the economic interest of the developing nations to use this carbon-free energy source. By delivering superior performance on longstanding public concerns about nuclear energy, it will be technologically and politically feasible for developing nations to stabilize their population with the bounty of energy cheaper than coal.

  2. Self-assembled nano-architecture liquid crystalline particles as a promising carrier for progesterone transdermal delivery.

    PubMed

    Elgindy, Nazik A; Mehanna, Mohammed M; Mohyeldin, Salma M

    2016-03-30

    The study aims to elaborate novel self-assembled liquid crystalline nanoparticles (LCNPs) for management of hormonal disturbances following non-invasive progesterone transdermal delivery. Fabrication and optimization of progesteroneloaded LCNPs for transdermal delivery were assessed via a quality by design approach based on 2(3) full factorial design. The design includes the functional relationships between independent processing variables and dependent responses of particle size, polydispersity index, zeta potential, cumulative drug released after 24h and ex-vivo transdermal steady flux. The developed nanocarrier was subjected to TEM (transmission electron microscope) for morphological elucidation and stability study within a period of three months at different storage temperatures. The cubic phase of LCNPs was successfully prepared using glyceryl monooleate (GMO) via the emulsification technique. Based on the factorial design, the independent operating variables significantly affected the five dependent responses. The cubosomes hydrodynamic diameters were in the nanometric range (101-386 nm) with narrow particle size distribution, high negative zeta potential ≥-30 mV and entrapment efficiency ≥94%. The LCNPs succeeded in sustaining progesterone release for almost 24h, following a non-fickian transport of drug diffusion mechanism. Ex-vivo study revealed a significant enhancement up to 6 folds in the transdermal permeation of progesterone-loaded LCNPs compared to its aqueous suspension. The optimized LCNPs exhibited a high physical stability while retaining the cubic structure for at least three months. Quality by design approach successfully accomplished a predictable mathematical model permitting the development of novel LCNPs for transdermal delivery of progesterone with the benefit of reducing its oral route side effects. PMID:26828671

  3. Characterization of Escherichia coli lactose carrier mutants that transport protons without a cosubstrate. Probes for the energy barrier to uncoupled transport.

    PubMed

    King, S C; Wilson, T H

    1990-06-15

    The Escherichia coli lactose carrier is an energy-transducing H+/galactoside cotransport protein which strictly couples sugar and proton transport in 1:1 stoichiometry. Here we describe five lactose carrier mutants which catalyze "uncoupled" sugar-independent H+ transport. Symptoms similar to uncoupling by a proton ionophore have been observed in cells expressing these mutant carriers. The mutations occur at two separate loci, encoding substitutions either for alanine 177 (valine) or tyrosine 236 (histidine, asparagine, phenylalanine, or serine). Compared to the parent, cells expressing the valine 177 carrier grew slowly on minimal media with glucose as carbon source. When washed cells were incubated in the absence of added sugars the mutant showed a reduced protonmotive force compared with the parent. Addition of either thiodigalactoside or alpha-p-nitrophenylgalactoside reduced the defect in protonmotive force. Sugar-independent H+ entry rate into cells expressing either the normal carrier or the Val-177 mutant were measured directly using the pH electrode. Following sudden acidification of the external medium (by either oxygen-pulse or acid-pulse) protons entered more rapidly into cells expressing the Val-177 carrier. This novel sugar-independent mode of H+ transport probably depends on an acquired capacity of the Val-177 carrier to bind the transported proton with higher than normal affinity in a transition state involving the binary carrier/H+ complex. PMID:2161839

  4. Effect of Energy Polydispersity on the Nature of Lennard-Jones Liquids.

    PubMed

    Ingebrigtsen, Trond S; Tanaka, Hajime

    2016-08-11

    In the companion paper [ Ingebrigtsen , T. S. ; Tanaka , H. J. Phys. Chem. B 2015 , 119 , 11052 ] the effect of size polydispersity on the nature of Lennard-Jones (LJ) liquids, which represent most molecular liquids without hydrogen bonds, was studied. More specifically, it was shown that even highly size polydisperse LJ liquids are Roskilde-simple (RS) liquids. RS liquids are liquids with strong correlation between constant volume equilibrium fluctuations of virial and potential energy and are simpler than other types of liquids. Moreover, it was shown that size polydisperse LJ liquids have isomorphs to a good approximation. Isomorphs are curves in the phase diagram of RS liquids along which structure, dynamics, and some thermodynamic quantities are invariant in dimensionless (reduced) units. In this paper, we study the effect of energy polydispersity on the nature of LJ liquids. We show that energy polydisperse LJ liquids are RS liquids. However, a tendency of particle segregation, which increases with the degree of polydispersity, leads to a loss of strong virial-potential energy correlation but is mitigated by increasing temperature and/or density. Isomorphs are a good approximation also for energy polydisperse LJ liquids, although particle-resolved quantities display a somewhat poorer scaling compared to the mean quantities along the isomorph. PMID:27434103

  5. Minimum energy, liquid hydrogen supersonic cruise vehicle study

    NASA Technical Reports Server (NTRS)

    Brewer, G. D.; Morris, R. E.

    1975-01-01

    The potential was examined of hydrogen-fueled supersonic vehicles designed for cruise at Mach 2.7 and at Mach 2.2. The aerodynamic, weight, and propulsion characteristics of a previously established design of a LH2 fueled, Mach 2.7 supersonic cruise vehicle (SCV) were critically reviewed and updated. The design of a Mach 2.2 SCV was established on a corresponding basis. These baseline designs were then studied to determine the potential of minimizing energy expenditure in performing their design mission, and to explore the effect of fuel price and noise restriction on their design and operating performance. The baseline designs of LH2 fueled aircraft were than compared with equivalent designs of jet A (conventional hydrocarbon) fueled SCV's. Use of liquid hydrogen for fuel for the subject aircraft provides significant advantages in performance, cost, noise, pollution, sonic boom, and energy utilization.

  6. Detecting energy dependent neutron capture distributions in a liquid scintillator

    NASA Astrophysics Data System (ADS)

    Balmer, Matthew J. I.; Gamage, Kelum A. A.; Taylor, Graeme C.

    2015-03-01

    A novel technique is being developed to estimate the effective dose of a neutron field based on the distribution of neutron captures in a scintillator. Using Monte Carlo techniques, a number of monoenergetic neutron source energies and locations were modelled and their neutron capture response was recorded. Using back propagation Artificial Neural Networks (ANN) the energy and incident direction of the neutron field was predicted from the distribution of neutron captures within a 6Li-loaded liquid scintillator. Using this proposed technique, the effective dose of 252Cf, 241AmBe and 241AmLi neutron fields was estimated to within 30% for four perpendicular angles in the horizontal plane. Initial theoretical investigations show that this technique holds some promise for real-time estimation of the effective dose of a neutron field.

  7. Thermoelectric energy recovery at ionic-liquid/electrode interface

    SciTech Connect

    Bonetti, Marco; Nakamae, Sawako; Huang, Bo Tao; Wiertel-Gasquet, Cécile; Roger, Michel; Salez, Thomas J.

    2015-06-28

    A thermally chargeable capacitor containing a binary solution of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide in acetonitrile is electrically charged by applying a temperature gradient to two ideally polarisable electrodes. The corresponding thermoelectric coefficient is −1.7 mV/K for platinum foil electrodes and −0.3 mV/K for nanoporous carbon electrodes. Stored electrical energy is extracted by discharging the capacitor through a resistor. The measured capacitance of the electrode/ionic-liquid interface is 5 μF for each platinum electrode while it becomes four orders of magnitude larger, ≈36 mF, for a single nanoporous carbon electrode. Reproducibility of the effect through repeated charging-discharging cycles under a steady-state temperature gradient demonstrates the robustness of the electrical charging process at the liquid/electrode interface. The acceleration of the charging by convective flows is also observed. This offers the possibility to convert waste-heat into electric energy without exchanging electrons between ions and electrodes, in contrast to what occurs in most thermogalvanic cells.

  8. Thermoelectric energy recovery at ionic-liquid/electrode interface.

    PubMed

    Bonetti, Marco; Nakamae, Sawako; Huang, Bo Tao; Salez, Thomas J; Wiertel-Gasquet, Cécile; Roger, Michel

    2015-06-28

    A thermally chargeable capacitor containing a binary solution of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide in acetonitrile is electrically charged by applying a temperature gradient to two ideally polarisable electrodes. The corresponding thermoelectric coefficient is -1.7 mV/K for platinum foil electrodes and -0.3 mV/K for nanoporous carbon electrodes. Stored electrical energy is extracted by discharging the capacitor through a resistor. The measured capacitance of the electrode/ionic-liquid interface is 5 μF for each platinum electrode while it becomes four orders of magnitude larger, ≈36 mF, for a single nanoporous carbon electrode. Reproducibility of the effect through repeated charging-discharging cycles under a steady-state temperature gradient demonstrates the robustness of the electrical charging process at the liquid/electrode interface. The acceleration of the charging by convective flows is also observed. This offers the possibility to convert waste-heat into electric energy without exchanging electrons between ions and electrodes, in contrast to what occurs in most thermogalvanic cells. PMID:26133450

  9. Thermoelectric energy recovery at ionic-liquid/electrode interface

    NASA Astrophysics Data System (ADS)

    Bonetti, Marco; Nakamae, Sawako; Huang, Bo Tao; Salez, Thomas J.; Wiertel-Gasquet, Cécile; Roger, Michel

    2015-06-01

    A thermally chargeable capacitor containing a binary solution of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide in acetonitrile is electrically charged by applying a temperature gradient to two ideally polarisable electrodes. The corresponding thermoelectric coefficient is -1.7 mV/K for platinum foil electrodes and -0.3 mV/K for nanoporous carbon electrodes. Stored electrical energy is extracted by discharging the capacitor through a resistor. The measured capacitance of the electrode/ionic-liquid interface is 5 μF for each platinum electrode while it becomes four orders of magnitude larger, ≈36 mF, for a single nanoporous carbon electrode. Reproducibility of the effect through repeated charging-discharging cycles under a steady-state temperature gradient demonstrates the robustness of the electrical charging process at the liquid/electrode interface. The acceleration of the charging by convective flows is also observed. This offers the possibility to convert waste-heat into electric energy without exchanging electrons between ions and electrodes, in contrast to what occurs in most thermogalvanic cells.

  10. Stopping power of liquid water for low-energy electrons

    SciTech Connect

    Ashley, J.C.

    1982-01-01

    The dielectric function epsilon(q,..omega..) for liquid water is determined from an insulator model with parameters fixed by available optical data. Ionization of the oxygen K shell is described by generalized oscillator strengths. This model dielectric function is used to calculate the stopping power of liquid water for electrons with energies from 10 eV to 10 keV. The results agree well in the common energy range with an existing tabulation for 256 eV less than or equal to E less than or equal to 10.2 MeV and with Bethe-theory predictions down to 200 eV. The peak in stopping power at approx.25% lower than the predictions of R. H. Ritchie, R. N. Hamm, J.E. Turner, and H. A. Wright (in Proceedings, Sixth Symposium on Microdosimetry, Brussels, Belgium (J. Booz and H. G. Ebert, Eds.), pp. 345-354, Commission of the European Communities, Harwood, London, 1978 (EUR 6064 d-e-f)).

  11. Separation of gallium and arsenic in wafer grinding extraction solution using a supported liquid membrane that contains PC88A as a carrier.

    PubMed

    Tsai, Chin-Ying; Chen, Yi-Fu; Chen, Wen-Ching; Yang, Fong-Ru; Chen, Jyh-Herng; Lin, Jing-Chie

    2005-01-01

    Wafer grinding extraction solution was passed through a supported liquid membrane (SLM) that contained PC88A (2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester) as a carrier, to separate gallium from arsenic by selective permeation. The SLM separation process was conducted under various conditions. The kind of membrane supporter, the pH of the feed, the feed concentration, and the HCl content in the strip governed the concentration of gallium and arsenic in the strip phase. The conditions determined as optimal in the laboratory test were used to perform the pilot test. Well separation between gallium and arsenic was performed in both laboratory and pilot tests. Hydrophobic membrane polytetrafluoroethylene (PTFE) with 0.2 microm pores was the best of three membrane supporters. The most efficient separation was obtained using an acidic feed (pH at 1.8) with 1000 ppm gallium. Over a 12-h period of stripping, the striped Ga concentration increased with the HCl concentration from 0.5 to 2.0 M and then leveled off. The recovery rate in the pilot test exceeded that on the laboratory scale because the membrane area was greater. The pilot test yielded a high recovery percentage of gallium (at 91%) and a low recovery of arsenic (merely 1.3 ppm) in the strip over 72 h. PMID:15717789

  12. Silicon quantum dots in SiO{sub x} dielectrics as energy selective contacts in hot carrier solar cells

    SciTech Connect

    Kar, Debjit; Das, Debajyoti

    2015-06-24

    Thin films of c-Si QDs embedded in a-SiO{sub x} dielectric matrix was achieved at a low temperature ∼400°C, from one step process by reactive rf magnetron co-sputtering of c-Si wafer and pure SiO{sub 2} targets, in the (H{sub 2}+Ar)- plasma. Formation of a double-barrier structure has been primarily identified from the SAX data and exclusively confirmed from the resonant tunneling current appearing in the J-E characteristic curve peaks, determined by the discrete energy levels of c-Si QDs, at which it could be used as energy selective contacts in hot carrier solar cells.

  13. Pyroelectric energy harvesting using liquid-based switchable thermal interfaces

    SciTech Connect

    Cha, G; Ju, YS

    2013-01-15

    The pyroelectric effect offers an intriguing solid-state approach for harvesting ambient thermal energy to power distributed networks of sensors and actuators that are remotely located or otherwise difficult to access. There have been, however, few device-level demonstrations due to challenges in converting spatial temperature gradients into temporal temperature oscillations necessary for pyroelectric energy harvesting. We demonstrate the feasibility of a device concept that uses liquid-based thermal interfaces for rapid switching of the thermal conductance between a pyroelectric material and a heat source/sink and can thereby deliver high output power density. Using a thin film of a pyroelectric co-polymer together with a macroscale mechanical actuator, we operate pyroelectric thermal energy harvesting cycles at frequencies close to 1 Hz. Film-level power densities as high as 110 mW/cm(3) were achieved, limited by slow heat diffusion across a glass substrate. When combined with a laterally interdigitated electrode array and a MEMS actuator, the present design offers an attractive option for compact high-power density thermal energy harvesters. (C) 2012 Elsevier B.V. All rights reserved.

  14. Recombination in liquid xenon for low-energy recoils

    NASA Astrophysics Data System (ADS)

    Wang, Lu; Mei, Dongming; Cubed Collaboration

    2014-09-01

    Detector response to low-energy recoils in sub-keV region is critical to detection of low-mass dark matter particles-WIMPS (Weakly interacting massive particles). The role of electron-ion recombination is important to the interpretation of the relation between ionization yield and scintillation yield, which are in general anti-correlated. Recent experimental results show that ionization yield increases down to keV range. This phenomenon contradicts general understanding for low energy recoils in the keV range in which direct excitation dominates. The explanation is that recombination becomes much less efficient when the track length is smaller than the thermalization distance of electrons. However, recombination rate is also proportional to ionization density, which is very high for keV recoils. To understand how recombination rate behaves for keV recoils, we calculated both initial recombination rate and volume recombination rate for keV recoils in liquid xenon. In this paper, we show the results of the calculated recombination rate as a function of recoil energy for both electronic recoils and nuclear recoils. Detector response to low-energy recoils in sub-keV region is critical to detection of low-mass dark matter particles-WIMPS (Weakly interacting massive particles). The role of electron-ion recombination is important to the interpretation of the relation between ionization yield and scintillation yield, which are in general anti-correlated. Recent experimental results show that ionization yield increases down to keV range. This phenomenon contradicts general understanding for low energy recoils in the keV range in which direct excitation dominates. The explanation is that recombination becomes much less efficient when the track length is smaller than the thermalization distance of electrons. However, recombination rate is also proportional to ionization density, which is very high for keV recoils. To understand how recombination rate behaves for keV recoils

  15. Does carrier size matter? A fundamental study of drug aerosolisation from carrier based dry powder inhalation systems.

    PubMed

    Ooi, Jesslynn; Traini, Daniela; Hoe, Susan; Wong, William; Young, Paul M

    2011-07-15

    There is plenty of evidence supporting the notion that the size of the carrier influences the aerosolisation performance of drug from a drug-carrier blend. Interestingly, that evidence is contradictory in places and the study of such mechanisms is fraught by the compounding variables associated with comparing crystalline powders (e.g. as size is varied so may the shape, surface chemistry, roughness and the amount of fine excipients). To overcome these limitations, a series of model polystyrene spheres were used to study the influence of size on aerosol performance. Three polystyrene sphere carriers (TS-80, TS-250 and TS-500, describing their approximate diameters) were characterised using laser diffraction, atomic force microscopy, colloid probe microscopy, electron microscopy, true density and dynamic vapour sorption. The model carriers were blended with micronized salbutamol sulphate (67.5:1 ratios) and the aerosolisation performance was tested using a multistage liquid impinger at a range of flow rates (40-100 lmin(-1)). Physico-chemical analysis of the carriers indicated that all carriers were spherical with similar roughness and densities. Furthermore, the adhesion force of drug to the carrier surfaces was independent of carrier size. Significant differences in drug aerosolisation were observed with both flow rate and carrier size. In general, as carrier size was increased, aerosol performance decreased. Furthermore, as flow rate was increased so did performance. Such observations suggest that higher energy processes drive aerosolisation, however this is likely to be due to the number of impaction events (and associated frictional and rotational forces) rather than the actual collision velocity (since the larger carriers had increased momentum and drag forces). This study shows that, in isolation of other variables, as carrier size increases, a concurrent decrease in drug aerosolisation performance is observed. PMID:21501674

  16. Thermodynamic analysis of alternate energy carriers, hydrogen and chemical heat pipes

    NASA Technical Reports Server (NTRS)

    Cox, K. E.; Carty, R. H.; Conger, W. L.; Soliman, M. A.; Funk, J. E.

    1976-01-01

    Hydrogen and chemical heat pipes were proposed as methods of transporting energy from a primary energy source (nuclear, solar) to the user. In the chemical heat pipe system, primary energy is transformed into the energy of a reversible chemical reaction; the chemical species are then transmitted or stored until the energy is required. Analysis of thermochemical hydrogen schemes and chemical heat pipe systems on a second law efficiency or available work basis show that hydrogen is superior especially if the end use of the chemical heat pipe is electrical power.

  17. Measuring liquid crystal elastic constants with free energy perturbations.

    PubMed

    Joshi, Abhijeet A; Whitmer, Jonathan K; Guzmán, Orlando; Abbott, Nicholas L; de Pablo, Juan J

    2014-02-14

    A first principles method is proposed to calculate the Frank elastic constants of nematic liquid crystals. These include the constants corresponding to standard splay, twist and bend deformations, and an often-ignored surface-like contribution known as saddle-splay. The proposed approach is implemented on the widely studied Gay-Berne (3, 5, 2, 1) model [J. G. Gay and B. J. Berne, J. Chem. Phys., 1981, 74, 3316], and the effects of temperature and system size on the elastic constants are examined in the nematic phase. The results of simulations for splay, twist, and bend elastic constants are consistent with those from previous literature reports. The method is subsequently applied to the saddle-splay elastic constant k24 which is found to exist at the limits of the Ericksen inequalities governing positive definite free energy. Finally, extensions of the method are discussed that present a new paradigm for in silico measurements of elastic constants. PMID:24837037

  18. Effect of liquid-to-solid lipid ratio on characterizations of flurbiprofen-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs) for transdermal administration.

    PubMed

    Song, Aihua; Zhang, Xiaoshu; Li, Yanting; Mao, Xinjuan; Han, Fei

    2016-08-01

    The aim of this study is to evaluate the effect of liquid-to-solid lipid ratio on properties of flurbiprofen-loaded solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs), and to clarify the superiority of NLCs over SLNs for transdermal administration. Particle size, zeta potential, drug encapsulation efficiency, in vitro occlusion factor, differential scanning calorimetry, X-ray diffractometry, in vitro percutaneous permeation profile, and stability of SLNs and NLCs were compared. Particle size, zeta potential, drug encapsulation efficiency, in vitro occlusion factor, and in vitro percutaneous permeation amount of the developed NLCs were all <200 nm, < -20 mV, >78%, >35, and >240 μg/cm(2), respectively, however, for SLNs were 280 nm, -29.11 mV, 63.2%, 32.54, and 225.9 μg/cm(2), respectively. After 3 months storage at 4 °C and 25 °C, almost no significant differences between the evaluated parameters of NLCs were observed. However, for SLNs, particle size was increased to higher than 300 nm (4 °C and 25 °C), drug encapsulation efficiency was decreased to 51.2 (25 °C), in vitro occlusion factor was also decreased to lower than 25 (4 °C and 25 °C), and the cumulative amount was decreased to 148.9 μg/cm(2) (25 °C) and 184.4 μg/cm(2) (4 °C), respectively. And DSC and XRD studies indicated that not only the crystalline peaks of the encapsulated flurbiprofen disappeared but also obvious difference between samples and bulk Compritol® ATO 888 was seen. It could be concluded that liquid-to-solid lipid ratio has significant impact on the properties of SLNs and NLCs, and NLCs showed better stability than SLNs. Therefore, NLCs might be a better option than SLNs for transdermal administration. PMID:26707734

  19. Activation energy and capture cross section of majority carrier traps in Zn doped InP

    NASA Technical Reports Server (NTRS)

    Rybicki, George; Williams, Wendell

    1993-01-01

    Schottky barrier diodes were fabricated on Zn doped InP Wafers. The diodes were radiation damaged with 2 MeV protons to a dose of 2 x 10(exp 12)cm(sup -2). The damage was analyzed by DLTS (deep level transient spectroscopy) using the double correlation technique. Capture cross sections were measured directly. Two major defects were observed in the DLTS spectra. The first defect, was H4 at Ev + 0.29 eV, with capture cross section 1.1 x 10(exp -17)cm(sup 2). The second defect, was H5 at Ev + 0.53 eV. Its capture cross section varied with temperature as described by the relationship sigma = sigma(sub 0) exp(delta(E)/kT) where sigma(sub 0) = 1.3 x 10(exp -19)cm(sup 2) and delta(E) = .08 eV. This relationship yields a sigma of 5.9 x 10(exp -21)cm(sup 2) at room temperature. The surprisingly small capture cross section of H5 and its temperature dependence are discussed in terms of the multiphonon emission process for carrier capture at the defect. The advantages of the improved experimental techniques used are also discussed.

  20. Crystallization of glass-forming liquids: Specific surface energy

    NASA Astrophysics Data System (ADS)

    Schmelzer, Jürn W. P.; Abyzov, Alexander S.

    2016-08-01

    A generalization of the Stefan-Skapski-Turnbull relation for the melt-crystal specific interfacial energy is developed in terms of the generalized Gibbs approach extending its standard formulation to thermodynamic non-equilibrium states. With respect to crystal nucleation, this relation is required in order to determine the parameters of the critical crystal clusters being a prerequisite for the computation of the work of critical cluster formation. As one of its consequences, a relation for the dependence of the specific surface energy of critical clusters on temperature and pressure is derived applicable for small and moderate deviations from liquid-crystal macroscopic equilibrium states. Employing the Stefan-Skapski-Turnbull relation, general expressions for the size and the work of formation of critical crystal clusters are formulated. The resulting expressions are much more complex as compared to the respective relations obtained via the classical Gibbs theory. Latter relations are retained as limiting cases of these more general expressions for moderate undercoolings. By this reason, the formulated, here, general relations for the specification of the critical cluster size and the work of critical cluster formation give a key for an appropriate interpretation of a variety of crystallization phenomena occurring at large undercoolings which cannot be understood in terms of the Gibbs' classical treatment.

  1. Measuring the internal energy content of molecules transported across the liquid-gas interface

    NASA Astrophysics Data System (ADS)

    Maselli, Olivia J.; Gascooke, Jason R.; Lawrance, Warren D.; Buntine, Mark A.

    2009-09-01

    Many details concerning the mechanism associated with the liberation of molecules from a liquid surface remain to be elucidated. We use the liquid microjet technique coupled with laser spectroscopy to measure the rotational and vibrational energy content of benzene spontaneously evaporating from a water-ethanol solution. These measurements provide molecular level insight into the mass and energy transfer processes associated with evaporation.

  2. Microscopic origins of the terahertz carrier relaxation and cooling dynamics in graphene.

    PubMed

    Mihnev, Momchil T; Kadi, Faris; Divin, Charles J; Winzer, Torben; Lee, Seunghyun; Liu, Che-Hung; Zhong, Zhaohui; Berger, Claire; de Heer, Walt A; Malic, Ermin; Knorr, Andreas; Norris, Theodore B

    2016-01-01

    The ultrafast dynamics of hot carriers in graphene are key to both understanding of fundamental carrier-carrier interactions and carrier-phonon relaxation processes in two-dimensional materials, and understanding of the physics underlying novel high-speed electronic and optoelectronic devices. Many recent experiments on hot carriers using terahertz spectroscopy and related techniques have interpreted the variety of observed signals within phenomenological frameworks, and sometimes invoke extrinsic effects such as disorder. Here, we present an integrated experimental and theoretical programme, using ultrafast time-resolved terahertz spectroscopy combined with microscopic modelling, to systematically investigate the hot-carrier dynamics in a wide array of graphene samples having varying amounts of disorder and with either high or low doping levels. The theory reproduces the observed dynamics quantitatively without the need to invoke any fitting parameters, phenomenological models or extrinsic effects such as disorder. We demonstrate that the dynamics are dominated by the combined effect of efficient carrier-carrier scattering, which maintains a thermalized carrier distribution, and carrier-optical-phonon scattering, which removes energy from the carrier liquid. PMID:27221060

  3. A fermi liquid electric structure and the nature of the carriers in high-T/sub c/ cuprates: A photoemission study

    SciTech Connect

    Arko, A.J.; List, R.S.; Bartlett, R.J.; Cheong, S.W.; Fisk, Z.; Thompson, J.D.; Olson, C.G.; Yang, A.B.; Liu, R.; Gu, C.; Veal, B.W.; Liu, J.Z.; Paulikas, A.P.; Vandervoort, K.; Claus, H.; Campuzano, J.C.; Schirber, J.E.; Shinn, N.D.

    1989-01-01

    We have performed angle-integrated and angle-resolved photoemission measurements at 20 K on well-characterized single crystals of high-T/sub c/ cuprates (both 1:2:3-type and 2:2:1:2-type) cleaved in situ, and find a relatively large, resolution limited Fermi edge which shows large amplitude variations with photon energy, indicative of band structure final state effects. The lineshapes of the spectra of the 1:2:3 materials as a function of photon energy are well reproduced by band structure predictions, indicating a correct mix of 2p and 3d orbitals on the calculations, while the energy positions of the peaks agree with calculated bands only to within /approx/0.5 eV. This may yet prove to reflect the effects of Coulomb correlation. We nevertheless conclude that a Fermi liquid approach to conductivity is appropriate. Angle-resolved data, while still incomplete, suggest agreement with the Fermi surface predicted by the LDA calculations. A BCS-like energy gap is observed in the 2:2:1:2 materials, whose magnitude is twice the weak coupling BCS value (i.e., 2/Delta/ = 7 KT/sub c/). 49 refs., 11 figs.

  4. Random walk numerical simulation for hopping transport at finite carrier concentrations: diffusion coefficient and transport energy concept.

    PubMed

    Gonzalez-Vazquez, J P; Anta, Juan A; Bisquert, Juan

    2009-11-28

    The random walk numerical simulation (RWNS) method is used to compute diffusion coefficients for hopping transport in a fully disordered medium at finite carrier concentrations. We use Miller-Abrahams jumping rates and an exponential distribution of energies to compute the hopping times in the random walk simulation. The computed diffusion coefficient shows an exponential dependence with respect to Fermi-level and Arrhenius behavior with respect to temperature. This result indicates that there is a well-defined transport level implicit to the system dynamics. To establish the origin of this transport level we construct histograms to monitor the energies of the most visited sites. In addition, we construct "corrected" histograms where backward moves are removed. Since these moves do not contribute to transport, these histograms provide a better estimation of the effective transport level energy. The analysis of this concept in connection with the Fermi-level dependence of the diffusion coefficient and the regime of interest for the functioning of dye-sensitised solar cells is thoroughly discussed. PMID:19890520

  5. Production of H2 from combined endothermic and exothermic hydrogen carriers.

    PubMed

    Wechsler, Dominik; Cui, Yi; Dean, Darrell; Davis, Boyd; Jessop, Philip G

    2008-12-17

    One of the major limitations to the use of fuel cell systems in vehicular transportation is the lack of hydrogen storage systems that have the required hydrogen storage density and moderate enthalpy of dehydrogenation. Organic liquid H(2) carriers that release H(2) endothermically are easier to handle with existing infrastructure because they are liquids, but they have low storage densities and their endothermicity consumes energy in the vehicle. On the other hand, inorganic solid H(2) carriers that release H(2) exothermically have greater storage densities but are unpumpable solids. This paper explores combinations of an endothermic carrier and an exothermic carrier, where the exothermic carrier provides some or all of the necessary heat required for dehydrogenation to the endothermic system, and the endothermic carrier serves as a solvent for the exothermic carrier. The two carriers can be either physically mixed or actually bonded to each other. To test the latter strategy, a number of chemically bound N-heterocycle:BH(3) adducts were synthesized and in turn tested for their ability to release H(2) by tandem hydrolysis of the BH(3) moiety and dehydrogenation of the heterocycle. To test the strategy of physically mixing two carriers, the hydrolysis of a variety of amine-boranes (H(3)N:BH(3), Me(2)HN:BH(3), Et(3)N:BH(3)) and the catalytic dehydrogenation of indoline were carried out together. PMID:19053482

  6. A Method for Calculating Fermi Energy and Carrier Concentrations in Semiconducts

    ERIC Educational Resources Information Center

    Gaylord, T. K.; Linxwiler, J. N., Jr.

    1976-01-01

    An efficient numerical method for calculating the Fermi energy, the free electron and free hole concentrations, and the ionized impurity conductors in a semiconductor material is described. The method allows freedom with respect to type of material, temperature, and amount and type of donor and acceptor impurities. (Author/CP)

  7. Nonresonant energy transfers independent on the phonon densities in polyatomic liquids.

    PubMed

    Chen, Hailong; Zhang, Qiang; Guo, Xunmin; Wen, Xiewen; Li, Jiebo; Zhuang, Wei; Zheng, Junrong

    2015-01-29

    Energy-gap-dependent vibrational-energy transfers among the nitrile stretches of KSCN/KS(13)CN/KS(13)C(15)N in D2O, DMF, and formamide liquid solutions at room temperature were measured by the vibrational-energy-exchange method. The energy transfers are slower with a larger energy donor/acceptor gap, independent of the calculated instantaneous normal mode ("phonons" in liquids) densities or the terahertz absorption spectra. The energy-gap dependences of the nonresonant energy transfers cannot be described by phonon compensation mechanisms with the assumption that phonons are the instantaneous normal modes of the liquids. Instead, the experimental energy-gap dependences can be quantitatively reproduced by the dephasing mechanism. A simple theoretical derivation shows that the fast molecular motions in liquids randomize the modulations on the energy donor and acceptor by phonons and diminish the phonon compensation efficiency on energy transfer. Estimations based on the theoretical derivations suggest that, for most nonresonant intermolecular vibrational-energy transfers in liquids with energy gaps smaller than the thermal energy, the dephasing mechanism dominates the energy-transfer process. PMID:25549247

  8. The inherent dynamics of a molecular liquid: Geodesic pathways through the potential energy landscape of a liquid of linear molecules

    NASA Astrophysics Data System (ADS)

    Jacobson, Daniel; Stratt, Richard M.

    2014-05-01

    Because the geodesic pathways that a liquid follows through its potential energy landscape govern its slow, diffusive motion, we suggest that these pathways are logical candidates for the title of a liquid's "inherent dynamics." Like their namesake "inherent structures," these objects are simply features of the system's potential energy surface and thus provide views of the system's structural evolution unobstructed by thermal kinetic energy. This paper shows how these geodesic pathways can be computed for a liquid of linear molecules, allowing us to see precisely how such molecular liquids mix rotational and translational degrees of freedom into their dynamics. The ratio of translational to rotational components of the geodesic path lengths, for example, is significantly larger than would be expected on equipartition grounds, with a value that scales with the molecular aspect ratio. These and other features of the geodesics are consistent with a picture in which molecular reorientation adiabatically follows translation—molecules largely thread their way through narrow channels available in the potential energy landscape.

  9. by ligand exchange: utilizing energy level alignment for efficiently reducing carrier rec ombination

    NASA Astrophysics Data System (ADS)

    Wang, Xia; Kou, Dong-Xing; Zhou, Wen-Hui; Zhou, Zheng-Ji; Wu, Si-Xin; Cao, Xuan

    2014-05-01

    In this work, we employed a convenient one-step synthesis method for synthesizing Cu2ZnSnSe4 (CZTSe) nanocrystals (NCs) in an excess selenium environment. This excess selenium situation enhanced the reaction of metal acetylacetonates with selenium, resulting in the burst nucleation of NCs at relatively low temperatures. The phase morphology and surface and optoelectronic properties of NCs before and after ligand exchange were discussed in depth. It was found that pure tetragonal-phase structure CZTSe NCs with approximately 1.7-eV bandgap could be synthesized. The removal of large organic molecules on CZTSe NCs after ligand exchange by S2- decreased the resistivity. The bandgap of the films after ligand exchange by 550°C selenization was also decreased due to better crystallinity. For potential application in CZTSe solar cells, we constructed an energy level diagram to explain the mutual effect between the absorption layer and CdS layer. Using cyclic voltammetry (CV) measurement, we found that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of CZTSe films shifted down after ligand exchange. After energy level alignment at the CdS/CZTSe interface, a type I band alignment structure was more conveniently formed after ligand exchange. This structure acted as the barrier against injection electrons from ZnO to the CZTSe layer, and recombination would subsequently be depressed.

  10. Long-Lived Hot Carriers in III-V Nanowires.

    PubMed

    Tedeschi, D; De Luca, M; Fonseka, H A; Gao, Q; Mura, F; Tan, H H; Rubini, S; Martelli, F; Jagadish, C; Capizzi, M; Polimeni, A

    2016-05-11

    Heat management mechanisms play a pivotal role in driving the design of nanowire (NW)-based devices. In particular, the rate at which charge carriers cool down after an external excitation is crucial for the efficiency of solar cells, lasers, and high-speed transistors. Here, we investigate the thermalization properties of photogenerated carriers by continuous-wave (cw) photoluminescence (PL) in InP and GaAs NWs. A quantitative analysis of the PL spectra recorded up to 310 K shows that carriers can thermalize at a temperature much higher than that of the lattice. We find that the mismatch between carrier and lattice temperature, ΔT, increases exponentially with lattice temperature and depends inversely on the NW diameter. ΔT is instead independent of other NW characteristics, such as crystal structure (wurtzite vs zincblende), chemical composition (InP vs GaAs), shape (tapered vs columnar NWs), and growth method (vapor-liquid-solid vs selective-area growth). Remarkably, carrier temperatures as high as 500 K are reached at the lattice temperature of 310 K in NWs with ∼70 nm diameter. While a population of nonequilibrium carriers, usually referred to as "hot carriers", is routinely generated by high-power laser pulses and detected by ultrafast spectroscopy, it is quite remarkable that it can be observed in cw PL measurements, when a steady-state population of carriers is established. Time-resolved PL measurements show that even in the thinnest NWs carriers have enough time (∼1 ns) after photoexcitation to interact with phonons and thus to release their excess energy. Nevertheless, the inability of carriers to reach a full thermal equilibrium with the lattice points to inhibited phonon emission primarily caused by the large surface-to-volume ratio of small diameter NWs. PMID:27104870

  11. Photoelectric energy conversion of plasmon-generated hot carriers in metal-insulator-semiconductor structures.

    PubMed

    García de Arquer, F Pelayo; Mihi, Agustín; Kufer, Dominik; Konstantatos, Gerasimos

    2013-04-23

    Plasmonic excitation in metals has received great attention for light localization and control of light-matter interactions at the nanoscale with a plethora of applications in absorption enhancement, surface-enhanced Raman scattering, or biosensing. Electrically active plasmonic devices, which had remained underexplored, have recently become a growing field of interest. In this report we introduce a metal-insulator-semiconductor heterostructure for plasmo-electric energy conversion, a novel architecture to harvest hot-electrons derived from plasmonic excitations. We demonstrate external quantum efficiency (EQE) of 4% at 460 nm using a Ag nanostructured electrode and EQE of 1.3% at 550 nm employing a Au nanostructured electrode. The insulator interfacial layer has been found to play a crucial role in interface passivation, a requisite in photovoltaic applications to achieving both high open-circuit voltages (0.5 V) and fill-factors (0.5), but its introduction simultaneously modifies hot-electron injection and transport. We investigate the influence passivation has on these processes for different material configurations, and characterize different types of transport depending on the initial plasmon energy band, reporting power conversion efficiencies of 0.03% for nanopatterned silver electrodes. PMID:23495769

  12. A strategy to minimize the energy offset in carrier injection from excited dyes to inorganic semiconductors for efficient dye-sensitized solar energy conversion.

    PubMed

    Fujisawa, Jun-Ichi; Osawa, Ayumi; Hanaya, Minoru

    2016-08-10

    Photoinduced carrier injection from dyes to inorganic semiconductors is a crucial process in various dye-sensitized solar energy conversions such as photovoltaics and photocatalysis. It has been reported that an energy offset larger than 0.2-0.3 eV (threshold value) is required for efficient electron injection from excited dyes to metal-oxide semiconductors such as titanium dioxide (TiO2). Because the energy offset directly causes loss in the potential of injected electrons, it is a crucial issue to minimize the energy offset for efficient solar energy conversions. However, a fundamental understanding of the energy offset, especially the threshold value, has not been obtained yet. In this paper, we report the origin of the threshold value of the energy offset, solving the long-standing questions of why such a large energy offset is necessary for the electron injection and which factors govern the threshold value, and suggest a strategy to minimize the threshold value. The threshold value is determined by the sum of two reorganization energies in one-electron reduction of semiconductors and typically-used donor-acceptor (D-A) dyes. In fact, the estimated values (0.21-0.31 eV) for several D-A dyes are in good agreement with the threshold value, supporting our conclusion. In addition, our results reveal that the threshold value is possible to be reduced by enlarging the π-conjugated system of the acceptor moiety in dyes and enhancing its structural rigidity. Furthermore, we extend the analysis to hole injection from excited dyes to semiconductors. In this case, the threshold value is given by the sum of two reorganization energies in one-electron oxidation of semiconductors and D-A dyes. PMID:27452717

  13. Comparison of carrier multiplication yields in PbS and PbSe nanocrystals: The role of competing energy-loss processes

    SciTech Connect

    Stewart, John T.; Padilha, Lazaro A.; Qazilbash, M. M.; Pietryga, Jeffrey M.; Midgett, Aaron G.; Luther, Joseph M.; Beard, Matthew C.; Nozik, Arthur J.; Klimov, Victor I.

    2012-02-08

    Infrared band gap semiconductor nanocrystals are promising materials for exploring generation III photovoltaic concepts that rely on carrier multiplication or multiple exciton generation, the process in which a single high-energy photon generates more than one electron–hole pair. In this work, we present measurements of carrier multiplication yields and biexciton lifetimes for a large selection of PbS nanocrystals and compare these results to the well-studied PbSe nanocrystals. The similar bulk properties of PbS and PbSe make this an important comparison for discerning the pertinent properties that determine efficient carrier multiplication. We observe that PbS and PbSe have very similar biexciton lifetimes as a function of confinement energy. Together with the similar bulk properties, this suggests that the rates of multiexciton generation, which is the inverse of Auger recombination, are also similar. The carrier multiplication yields in PbS nanocrystals, however, are strikingly lower than those observed for PbSe nanocrystals. We suggest that this implies the rate of competing processes, such as phonon emission, is higher in PbS nanocrystals than in PbSe nanocrystals. Indeed, our estimations for phonon emission mediated by the polar Fröhlich-type interaction indicate that the corresponding energy-loss rate is approximately twice as large in PbS than in PbSe.

  14. Comparison of carrier multiplication yields in PbS and PbSe nanocrystals: the role of competing energy-loss processes.

    PubMed

    Stewart, John T; Padilha, Lazaro A; Qazilbash, M Mumtaz; Pietryga, Jeffrey M; Midgett, Aaron G; Luther, Joseph M; Beard, Matthew C; Nozik, Arthur J; Klimov, Victor I

    2012-02-01

    Infrared band gap semiconductor nanocrystals are promising materials for exploring generation III photovoltaic concepts that rely on carrier multiplication or multiple exciton generation, the process in which a single high-energy photon generates more than one electron-hole pair. In this work, we present measurements of carrier multiplication yields and biexciton lifetimes for a large selection of PbS nanocrystals and compare these results to the well-studied PbSe nanocrystals. The similar bulk properties of PbS and PbSe make this an important comparison for discerning the pertinent properties that determine efficient carrier multiplication. We observe that PbS and PbSe have very similar biexciton lifetimes as a function of confinement energy. Together with the similar bulk properties, this suggests that the rates of multiexciton generation, which is the inverse of Auger recombination, are also similar. The carrier multiplication yields in PbS nanocrystals, however, are strikingly lower than those observed for PbSe nanocrystals. We suggest that this implies the rate of competing processes, such as phonon emission, is higher in PbS nanocrystals than in PbSe nanocrystals. Indeed, our estimations for phonon emission mediated by the polar Fröhlich-type interaction indicate that the corresponding energy-loss rate is approximately twice as large in PbS than in PbSe. PMID:22148950

  15. High Voltage in Noble Liquids for High Energy Physics

    SciTech Connect

    Rebel, B.; Bernard, E.; Faham, C. H.; Ito, T. M.; Lundberg, B.; Messina, M.; Monrabal, F.; Pereverzev, S. P.; Resnati, F.; Rowson, P. C.; Soderberg, M.; Strauss, T.; Tomas, A.; Va'vra, J.; Wang, H.

    2014-08-22

    A workshop was held at Fermilab November 8-9, 2013 to discuss the challenges of using high voltage in noble liquids. The participants spanned the fields of neutrino, dark matter, and electric dipole moment physics. All presentations at the workshop were made in plenary sessions. This document summarizes the experiences and lessons learned from experiments in these fields at developing high voltage systems in noble liquids.

  16. Solid-Liquid Interfacial Energy of Solid Succinonitrile in Equilibrium with Succinonitrile-(D)Camphor-Aminomethylpropanediol Eutectic Liquid

    NASA Astrophysics Data System (ADS)

    Ata, Pınar; Karamazı, Yasin; Bayram, Ümit; Aksöz, Sezen; Keşlioğlu, Kazım; Maraşlı, Necmettin

    2016-01-01

    The grain boundary groove shapes for equilibrated solid SCN in equilibrium with the eutectic liquid SCN-15.6 mol% DC-2.1 mol% AMPD have been directly observed by using a horizontal linear temperature gradient apparatus. The ratio of the thermal conductivity of the equilibrated liquid to the thermal conductivity of solid SCN has also been determined to be 0.89. From the observed grain boundary groove shapes and measured thermal conductivity ratio, the Gibbs-Thomson coefficient ({{\\varGamma }}), solid-liquid interfacial energy (σ _{SL}), and the grain boundary energy (σ _{gb}) have been determined to be (5.43 ± 0.54)× 10^{-8} K{\\cdot } m, (8.53 ± 1.28) × 10^{-3} J {\\cdot } m^{-2}, and (13.36 ± 2.14) × 10^{-3} J{\\cdot } m^{-2}, respectively, for equilibrated solid SCN in equilibrium with the eutectic liquid (SCN-15.6 mol% DC-2.1 mol% AMPD).

  17. A coherent understanding of low-energy nuclear recoils in liquid xenon

    SciTech Connect

    Sorensen, Peter

    2010-09-01

    Liquid xenon detectors such as XENON10 and XENON100 obtain a significant fraction of their sensitivity to light (∼<10 GeV) particle dark matter by looking for nuclear recoils of only a few keV, just above the detector threshold. Yet in this energy regime a correct treatment of the detector threshold and resolution remains unclear. The energy dependence of the scintillation yield of liquid xenon for nuclear recoils also bears heavily on detector sensitivity, yet numerous measurements have not succeeded in obtaining concordant results. In this article we show that the ratio of detected ionization to scintillation can be leveraged to constrain the scintillation yield. We also present a rigorous treatment of liquid xenon detector threshold and energy resolution. Notably, the effective energy resolution differs significantly from a simple Poisson distribution. We conclude with a calculation of dark matter exclusion limits, and show that existing data from liquid xenon detectors strongly constrain recent interpretations of light dark matter.

  18. Short-Term Energy Outlook Model Documentation: Hydrocarbon Gas Liquids Supply and Demand

    EIA Publications

    2015-01-01

    The hydrocarbon gas liquids (ethane, propane, butanes, and natural gasoline) module of the Short-Term Energy Outlook (STEO) model is designed to provide forecasts of U.S. production, consumption, refinery inputs, net imports, and inventories.

  19. Numerical and experimental studies of liquid storage tank thermal stratification for a solar energy system

    SciTech Connect

    Wu, S T; Han, S M

    1980-11-01

    The results of theoretical and experimental studies of thermal stratification in liquid energy storage tanks for the performance of solar energy systems are presented. The investigation was divided into three areas: (1) Justification of the Importance of Thermal Stratification Inside the Energy Storage Tanks, (II) Development of a Simple Mathematical Model which is Compatible with Existing Solar Energy System Simulation Code, and (III) Validation of Mathematical Models by Experimental Data Obtained from Realistic Solar Energy System Operations.

  20. Ionic liquids and their solid-state analogues as materials for energy generation and storage

    NASA Astrophysics Data System (ADS)

    Macfarlane, Douglas R.; Forsyth, Maria; Howlett, Patrick C.; Kar, Mega; Passerini, Stefano; Pringle, Jennifer M.; Ohno, Hiroyuki; Watanabe, Masayoshi; Yan, Feng; Zheng, Wenjun; Zhang, Shiguo; Zhang, Jie

    2016-02-01

    Salts that are liquid at room temperature, now commonly called ionic liquids, have been known for more than 100 years; however, their unique properties have only come to light in the past two decades. In this Review, we examine recent work in which the properties of ionic liquids have enabled important advances to be made in sustainable energy generation and storage. We discuss the use of ionic liquids as media for synthesis of electromaterials, for example, in the preparation of doped carbons, conducting polymers and intercalation electrode materials. Focusing on their intrinsic ionic conductivity, we examine recent reports of ionic liquids used as electrolytes in emerging high-energy-density and low-cost batteries, including Li-ion, Li-O2, Li-S, Na-ion and Al-ion batteries. Similar developments in electrolyte applications in dye-sensitized solar cells, thermo-electrochemical cells, double-layer capacitors and CO2 reduction are also discussed.

  1. Energy loss and small angle scattering of swift protons passing through liquid ethanol target

    NASA Astrophysics Data System (ADS)

    Kaneda, M.; Sato, S.; Shimizu, M.; He, Z.; Ishii, K.; Tsuchida, H.; Itoh, A.

    2007-03-01

    We have measured energy and angular distributions of fast protons passing through an ethanol liquid jet target. By applying the Moliére's theory of multiple scattering, we reproduced successfully our experimental results of energy and angular distributions and found that the Moliére's theory is useful for the prediction of energetic proton and heavy ion deflection in liquid materials. Moreover, we compared stopping powers obtained from our experiment with SRIM2003 and found an about 10% discrepancy between them. The present method can become a powerful tool for the measurement of particle stopping in liquids and the other collision interactions.

  2. Ionic Liquids as Electrolytes for Electrochemical Double-Layer Capacitors: Structures that Optimize Specific Energy.

    PubMed

    Mousavi, Maral P S; Wilson, Benjamin E; Kashefolgheta, Sadra; Anderson, Evan L; He, Siyao; Bühlmann, Philippe; Stein, Andreas

    2016-02-10

    Key parameters that influence the specific energy of electrochemical double-layer capacitors (EDLCs) are the double-layer capacitance and the operating potential of the cell. The operating potential of the cell is generally limited by the electrochemical window of the electrolyte solution, that is, the range of applied voltages within which the electrolyte or solvent is not reduced or oxidized. Ionic liquids are of interest as electrolytes for EDLCs because they offer relatively wide potential windows. Here, we provide a systematic study of the influence of the physical properties of ionic liquid electrolytes on the electrochemical stability and electrochemical performance (double-layer capacitance, specific energy) of EDLCs that employ a mesoporous carbon model electrode with uniform, highly interconnected mesopores (3DOm carbon). Several ionic liquids with structurally diverse anions (tetrafluoroborate, trifluoromethanesulfonate, trifluoromethanesulfonimide) and cations (imidazolium, ammonium, pyridinium, piperidinium, and pyrrolidinium) were investigated. We show that the cation size has a significant effect on the electrolyte viscosity and conductivity, as well as the capacitance of EDLCs. Imidazolium- and pyridinium-based ionic liquids provide the highest cell capacitance, and ammonium-based ionic liquids offer potential windows much larger than imidazolium and pyridinium ionic liquids. Increasing the chain length of the alkyl substituents in 1-alkyl-3-methylimidazolium trifluoromethanesulfonimide does not widen the potential window of the ionic liquid. We identified the ionic liquids that maximize the specific energies of EDLCs through the combined effects of their potential windows and the double-layer capacitance. The highest specific energies are obtained with ionic liquid electrolytes that possess moderate electrochemical stability, small ionic volumes, low viscosity, and hence high conductivity, the best performing ionic liquid tested being 1-ethyl-3

  3. Thermochemical Energy Storage through De/Hydrogenation of Organic Liquids: Reactions of Organic Liquids on Metal Hydrides.

    PubMed

    Ulmer, Ulrich; Cholewa, Martin; Diemant, Thomas; Bonatto Minella, Christian; Dittmeyer, Roland; Behm, R Jürgen; Fichtner, Maximilian

    2016-06-01

    A study of the reactions of liquid acetone and toluene on transition metal hydrides, which can be used in thermal energy or hydrogen storage applications, is presented. Hydrogen is confined in TiFe, Ti0.95Zr0.05Mn1.49V0.45Fe0.06 ("Hydralloy C5"), and V40Fe8Ti26Cr26 after contact with acetone. Toluene passivates V40Fe8Ti26Cr26 completely for hydrogen desorption while TiFe is only mildly deactivated and desorption is not blocked at all in the case of Hydralloy C5. LaNi5 is inert toward both organic liquids. Gas chromatography (GC) investigations reveal that CO, propane, and propene are formed during hydrogen desorption from V40Fe8Ti26Cr26 in liquid acetone, and methylcyclohexane is formed in the case of liquid toluene. These reactions do not occur if dehydrogenated samples are used, which indicates an enhanced surface reactivity during hydrogen desorption. Significant amounts of carbon-containing species are detected at the surface and subsurface of acetone- and toluene-treated V40Fe8Ti26Cr26 by X-ray photoelectron spectroscopy (XPS). The modification of the surface and subsurface chemistry and the resulting blocking of catalytic sites is believed to be responsible for the containment of hydrogen in the bulk. The surface passivation reactions occur only during hydrogen desorption of the samples. PMID:27183004

  4. Solid-liquid interfacial energy of neopentylglycol solid solution in equilibrium with neopentylglycol-(D) camphor eutectic liquid

    NASA Astrophysics Data System (ADS)

    Bayram, Ü.; Aksöz, S.; Maraşlı, N.

    2012-01-01

    The grain boundary groove shapes for equilibrated solid neopentylglycol (NPG) solution (NPG-3 mol% D-camphor) in equilibrium with the NPG-DC eutectic liquid (NPG-36.1 mol% D-camphor) have been directly observed using a horizontal linear temperature gradient apparatus. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficient ( Г), solid-liquid interfacial energy ( σSL) of NPG solid solution have been determined to be (7.5±0.7)×10 -8 K m and (8.1±1.2)×10 -3 J m -2, respectively. The Gibbs-Thomson coefficient versus TmΩ1/3, where Ω is the volume per atom was also plotted by linear regression for some organic transparent materials and the average value of coefficient ( τ) for nonmetallic materials was obtained to be 0.32 from graph of the Gibbs-Thomson coefficient versus TmΩ1/3. The grain boundary energy of solid NPG solution phase has been determined to be (14.6±2.3)×10 -3 J m -2 from the observed grain boundary groove shapes. The ratio of thermal conductivity of equilibrated eutectic liquid to thermal conductivity of solid NPG solution was also measured to be 0.80.

  5. Photon upconversion with hot carriers in plasmonic systems

    SciTech Connect

    Naik, Gururaj V.; Dionne, Jennifer A.

    2015-09-28

    We propose a scheme of photon upconversion based on harnessing the energy of plasmonic hot carriers. Low-energy photons excite hot electrons and hot holes in a plasmonic nanoparticle, which are then injected into an adjacent semiconductor quantum well where they radiatively recombine to emit a photon of higher energy. We theoretically study the proposed upconversion scheme using Fermi-liquid theory and determine the internal quantum efficiency of upconversion to be as high as 25% in 5 nm silver nanocubes. This upconversion scheme is linear in its operation, does not require coherent illumination, offers spectral tunability, and is more efficient than conventional upconverters.

  6. Nuclear recoil energy scale in liquid xenon with application to the direct detection of dark matter

    SciTech Connect

    Sorensen, P; Dahl, C E

    2011-02-14

    We show for the first time that the quenching of electronic excitation from nuclear recoils in liquid xenon is well-described by Lindhard theory, if the nuclear recoil energy is reconstructed using the combined (scintillation and ionization) energy scale proposed by Shutt et al.. We argue for the adoption of this perspective in favor of the existing preference for reconstructing nuclear recoil energy solely from primary scintillation. We show that signal partitioning into scintillation and ionization is well-described by the Thomas-Imel box model. We discuss the implications for liquid xenon detectors aimed at the direct detection of dark matter.

  7. Measurement of solid liquid interfacial energy in the pyrene succinonitrile monotectic system

    NASA Astrophysics Data System (ADS)

    Akbulut, S.; Ocak, Y.; Böyük, U.; Erol, M.; Keslioglu, K.; Marasli, N.

    2006-09-01

    The equilibrated grain boundary groove shapes for solid pyrene (PY) in equilibrium with the PY succinonitrile (SCN) monotectic liquid were directly observed. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficient and solid-liquid interfacial energy for solid PY in equilibrium with the PY SCN monotectic liquid have been determined to be (8.72 ± 0.87) × 10-8 K m and (21.9 ± 3.28) × 10-3 J m-2 with the present numerical method and Gibbs-Thomson equation, respectively. The grain boundary energy of the solid PY phase has been determined to be (42.84 ± 7.28) × 10-3 J m-2 from the observed grain boundary groove shapes. Thermal conductivities of solid and liquid phases for PY-2.5 mol% SCN alloy and pure PY have also been measured.

  8. Process for utilizing energy produced by the phase change of liquid

    SciTech Connect

    Tanaka, S.

    1980-03-11

    The present invention relates to a process for utilizing energy produced by the phase change of liquid, such as fluoronated hydrocarbon, light fraction hydrocarbon, lower alcohol and ethers using the heat coming from unused heat sources for example, the heat of the earth, the heat of hot springs, the heat of the warm waste water of factory and power plant. The present invention is applicable to transfer the heat of the unused heat source from the low place to the high place in order to use said heat for farming and cultivation at the high and cold places. The present invention is also applicable to transfer of the mass energy of the liquid from the low place to the high place by uniformly mixing the said liquid with the ascending saturated or supersaturated vapor of the said liquid.

  9. Rockets using Liquid Oxygen

    NASA Technical Reports Server (NTRS)

    Busemann, Adolf

    1947-01-01

    It is my task to discuss rocket propulsion using liquid oxygen and my treatment must be highly condensed for the ideas and experiments pertaining to this classic type of rocket are so numerous that one could occupy a whole morning with a detailed presentation. First, with regard to oxygen itself as compared with competing oxygen carriers, it is known that the liquid state of oxygen, in spite of the low boiling point, is more advantageous than the gaseous form of oxygen in pressure tanks, therefore only liquid oxygen need be compared with the oxygen carriers. The advantages of liquid oxygen are absolute purity and unlimited availability at relatively small cost in energy. The disadvantages are those arising from the impossibility of absolute isolation from heat; consequently, allowance must always be made for a certain degree of vaporization and only vented vessels can be used for storage and transportation. This necessity alone eliminates many fields of application, for example, at the front lines. In addition, liquid oxygen has a lower specific weight than other oxygen carriers, therefore many accessories become relatively larger and heavier in the case of an oxygen rocket, for example, the supply tanks and the pumps. The advantages thus become effective only in those cases where definitely scheduled operation and a large ground organization are possible and when the flight requires a great concentration of energy relative to weight. With the aim of brevity, a diagram of an oxygen rocket will be presented and the problem of various component parts that receive particularly thorough investigation in this classic case but which are also often applicable to other rocket types will be referred to.

  10. Transport and capture properties of Auger-generated high-energy carriers in (AlInGa)N quantum well structures

    SciTech Connect

    Nirschl, A.; Binder, M.; Schmid, M.; Karow, M. M.; Pietzonka, I.; Lugauer, H.-J.; Zeisel, R.; Sabathil, M.; Galler, B.; Bougeard, D.

    2015-07-21

    Recent photoluminescence experiments presented by M. Binder et al. [Appl. Phys. Lett. 103, 071108 (2013)] demonstrated the visualization of high-energy carriers generated by Auger recombination in (AlInGa)N multi quantum wells. Two fundamental limitations were deduced which reduce the detection efficiency of Auger processes contributing to the reduction in internal quantum efficiency: the transfer probability of these hot electrons and holes in a detection well and the asymmetry in type of Auger recombination. We investigate the transport and capture properties of these high-energy carriers regarding polarization fields, the transfer distance to the generating well, and the number of detection wells. All three factors are shown to have a noticeable impact on the detection of these hot particles. Furthermore, the investigations support the finding that electron-electron-hole exceeds electron-hole-hole Auger recombination if the densities of both carrier types are similar. Overall, the results add to the evidence that Auger processes play an important role in the reduction of efficiency in (AlInGa)N based LEDs.

  11. Enhanced coupling of optical energy during liquid-confined metal ablation

    SciTech Connect

    Kang, Hyun Wook; Welch, Ashley J.

    2015-10-21

    Liquid-confined laser ablation was investigated with various metals of indium, aluminum, and nickel. Ablation threshold and rate were characterized in terms of surface deformation, transient acoustic responses, and plasma emissions. The surface condition affected the degree of ablation dynamics due to variations in reflectance. The liquid confinement yielded up to an order of larger ablation crater along with stronger acoustic transients than dry ablation. Enhanced ablation performance resulted possibly from effective coupling of optical energy at the interface during explosive vaporization, plasma confinement, and cavitation. The deposition of a liquid layer can induce more efficient ablation for laser metal processing.

  12. Solidification Processing of Immiscible Liquids in the Presence of Applied Ultrasonic Energy

    NASA Technical Reports Server (NTRS)

    Kim, Shinwood; Grugel, R. N.

    2000-01-01

    Uniform microstructural development during solidification of immiscible liquids on Earth is hampered by inherent density differences between the phases. Microgravity processing minimizes settling but segregation still occurs due to gravity independent wetting and coalescence phenomena. Experiments with the transparent organic, metal analogue, succinonitrile-glycerol system were conducted in conjunction with applied ultrasonic energy. The processing parameters associated with this technique have been evaluated in view of optimizing dispersion uniformity. Experimental results to evaluate microstructural phase distributions, based on other liquid-liquid immiscibility systems, will also be presented.

  13. Novel 2-alkyl-1-ethylpyridinium ionic liquids: synthesis, dissociation energies and volatility.

    PubMed

    Vilas, Miguel; Rocha, Marisa A A; Fernandes, Ana M; Tojo, Emilia; Santos, Luís M N B F

    2015-01-28

    This work presents the synthesis, volatility study and electrospray ionization mass spectrometry with energy-variable collision induced dissociation of the isolated [(cation)2(anion)](+) of a novel series of 2-alkyl-1-ethyl pyridinium based ionic liquids, [(2)CN-2(1)C2Py][NTf2]. Compared to the imidazolium based ionic liquids, the new ionic liquid series presents a higher thermal stability and lower volatility. The [(cation)2(anion)](+) collision induced dissociation energies of both [(2)CN-2(1)C2Py][NTf2] and [CNPy][NTf2] pyridinium series show an identical trend with a pronounced decrease of the relative cation-anion interaction energy towards an almost constant value for N = 6. It was found that the lower volatility of [(2)CN-2(1)C2Py][NTf2] with a shorter alkyl chain length is due to its higher enthalpy of vaporization. Starting from [(2)C3(1)C2Py][NTf2], the lower volatility is governed by the combination of slightly lower entropies and higher enthalpies of vaporization, an indication of a higher structural disorder of the pyridinium based ionic liquids than the imidazolium based ionic liquids. Dissociation energies and volatility trends support the cohesive energy interpretation model based on the overlapping of the electrostatic and van der Waals functional interaction potentials. PMID:25493639

  14. X-ray ionization yields and energy spectra in liquid argon

    NASA Astrophysics Data System (ADS)

    Bondar, A.; Buzulutskov, A.; Dolgov, A.; Shekhtman, L.; Sokolov, A.

    2016-04-01

    The main purpose of this work is to provide reference data on X-ray ionization yields and energy spectra in liquid Ar to the studies in the field of Cryogenic Avalanche Detectors (CRADs) for rare-event and other experiments, based on liquid Ar detectors. We present the results of two related researches. First, the X-ray recombination coefficients in the energy range of 10-1000 keV and ionization yields at different electric fields, between 0.6 and 2.3 kV/cm, are determined in liquid Ar based on the results of a dedicated experiment. Second, the energy spectra of pulsed X-rays in liquid Ar in the energy range of 15-40 keV, obtained in given experiments including that with the two-phase CRAD, are interpreted and compared to those calculated using a computer program, to correctly determine the absorbed X-ray energy. The X-ray recombination coefficients and ionization yields have for the first time been presented for liquid Ar in systematic way.

  15. POWER DENSITY, FIELD INTENSITY, AND CARRIER FREQUENCY DETERMINANTS OF RF-ENERGY-INDUCED CALCIUM-ION EFFLUX FROM BRAIN TISSUE

    EPA Science Inventory

    To explain a carrier frequency dependence reported for radiofrequency (RF)-induced calcium-ion efflux from brain tissue, a chick-brain hemisphere bathed in buffer solution is modeled as a sphere within the uniform field of the incident electromagnetic wave. Calculations on a sphe...

  16. High energy-density liquid rocket fuel performance

    NASA Technical Reports Server (NTRS)

    Rapp, Douglas C.

    1990-01-01

    A fuel performance database of liquid hydrocarbons and aluminum-hydrocarbon fuels was compiled using engine parametrics from the Space Transportation Engine Program as a baseline. Propellant performance parameters are introduced. General hydrocarbon fuel performance trends are discussed with respect to hydrogen-to-carbon ratio and heat of formation. Aluminum-hydrocarbon fuel performance is discussed with respect to aluminum metal loading. Hydrocarbon and aluminum-hydrocarbon fuel performance is presented with respect to fuel density, specific impulse and propellant density specific impulse.

  17. High energy-density liquid rocket fuel performance

    NASA Technical Reports Server (NTRS)

    Rapp, Douglas C.

    1990-01-01

    A fuel performance database of liquid hydrocarbons and aluminum-hydrocarbon fuels was compiled using engine parametrics from the Space Transportation Engine Program as a baseline. Propellant performance parameters are introduced. General hydrocarbon fuel performance trends are discussed with respect to hydrogen-to-carbon ratio and heat of formation. Aluminum-hydrocarbon fuel performance is discussed with respect to aluminum metal loading. Hydrocarbon and aluminum-hydrocarbon fuel performance is presented with respect to fuel density, specific impulse, and propellant density specific impulse.

  18. Carrier dynamics and activation energy of CdTe quantum dots in a Cd{sub x}Zn{sub 1-x}Te quantum well

    SciTech Connect

    Han, W. I.; Lee, J. H.; Yu, J. S.; Choi, J. C.; Lee, H. S.

    2011-12-05

    We investigate the optical properties of CdTe quantum dots (QDs) in a Cd{sub 0.3}Zn{sub 0.7}Te quantum well (QW) grown on GaAs (100) substrates. Carrier dynamics of CdTe/ZnTe QDs and quantum dots-in-a-well (DWELL) structure is studied using time-resolved photoluminescence (PL) measurements, which show the longer exciton lifetime of the DWELL structure. The activation energy of the electrons confined in the DWELL structure, as obtained from the temperature-dependent PL spectra, was also higher than that of electrons confined in the CdTe/ZnTe QDs. This behavior is attributed to the better capture of carriers into QDs within the surrounding QW.

  19. Separation of alkali, alkaline earth and rare earth cations by liquid membranes containing macrocyclic carriers. Fourth progress report, 1 November 1981-31 July 1982

    SciTech Connect

    Christensen, J J; Izatt, R M

    1982-07-31

    The H/sub 2/O-CHCl/sub 3/-H/sub 2/O liquid membrane system was characterized with respect to the effect on cation (K/sup +/) transport rate of salt concentration and anion type. A bulk liquid membrane cell was used. A mathematical model for cation flux is being developed for several cations, several macrocycles, and mixtures of two or three cations. Eu/sup 3 +/ was not transported by 18-crown-6, but its reduced from Eu/sup 2 +/ was. Cation transport properties of calixarenes are also being investigated. Emulsion membrane systems were studied as a way of increasing the cation transport. Pb/sup 2 +/ was found to be transported by dicyclohexano-18-crown-6 through the liquid membrane. Transport rates of metal cation nitrates were measured in a water-toluene-water emulsion membrane system. 14 figures, 7 tables. (DLC)

  20. Bulk liquid membrane for the recovery of chromium(VI) from a hydrochloric acid medium using dicyclohexano-18-crown-6 as extractant-carrier

    SciTech Connect

    Zouhri, A.; Ernst, B.; Burgard, M.

    1999-06-01

    The solvent extraction and transfer of chromic acid from hydrochloric acid medium through a bulk liquid membrane containing dicyclohexano-18-crown-6 (L) were studied. Extraction experiments pointed out that chromium(VI) was coextracted with the chloride ion which formed the complex ion pair L(H{sub 3}O{sup +})CrO{sub 3}Cl{sup {minus}} in the organic phase. The Donnan equilibrium isotherm based on the extraction, stripping, and CrO{sub 3}Cl{sup {minus}} hydrolysis equilibria allowed prediction of the performance of the semipermeable membrane to concentrate chlorochromic acid in the receiving phase. Transport experiments confirmed the ability of the liquid membrane to recover chlorochromic acid in pure water. The transport kinetics was modeled by using the two-film theory applied to the liquid membrane.

  1. Energy and materials flows in the production of liquid and gaseous oxygen

    SciTech Connect

    Shen, S.; Wolsky, A.M.

    1980-08-01

    Liquid and gaseous oxygen is produced in an energy-intensive air separation processo that also generates nitrogen. More than 65% of the cost of oxygen is attributable to energy costs. Energy use and materials flows are analyzed for various air separation methods. Effective approaches to energy and material conservation in air separation plants include efficient removal of contaminants (carbon dioxide and water), centralization of air products user-industries so that large air separation plants are cost-effective and the energy use in transportation is minimized, and increased production of nitrogen. Air separation plants can produce more than three times more nitrogen than oxygen, but present markets demand, at most, only 1.5 times more. Full utlization of liquid and gaseous nitrogen should be encouraged, so that the wasted separation energy is minimized. There are potential markets for nitrogen in, for example, cryogenic separation of metallic and plastic wastes, cryogenic particle size reduction, and production of ammonia for fertilizer.

  2. Liquid-metal MHD-generator system with an inductive energy storage unit

    NASA Astrophysics Data System (ADS)

    Baranov, G. A.; Breev, V. V.; Dmitriev, K. I.; Karasev, B. G.; Lavrentev, I. V.

    1982-06-01

    The paper examines a liquid-metal MHD generator system intended as an electrical energy source for a thermonuclear reactor. The optimal characteristics of the system are examined, and it is shown, by feeding the inductive energy storage unit from the MHD generator, it is possible to achieve a total efficiency of 40% for a stored energy of 10-1000 MJ in the inductive unit.

  3. Quantification of breast density using dual-energy mammography with liquid phantom calibration

    NASA Astrophysics Data System (ADS)

    Lam, Alfonso R.; Ding, Huanjun; Molloi, Sabee

    2014-07-01

    Breast density is a widely recognized potential risk factor for breast cancer. However, accurate quantification of breast density is a challenging task in mammography. The current use of plastic breast-equivalent phantoms for calibration provides limited accuracy in dual-energy mammography due to the chemical composition of the phantom. We implemented a breast-equivalent liquid phantom for dual-energy calibration in order to improve the accuracy of breast density measurement. To design these phantoms, three liquid compounds were chosen: water, isopropyl alcohol, and glycerol. Chemical compositions of glandular and adipose tissues, obtained from NIST database, were used as reference materials. Dual-energy signal of the liquid phantom at different breast densities (0% to 100%) and thicknesses (1 to 8 cm) were simulated. Glandular and adipose tissue thicknesses were estimated from a higher order polynomial of the signals. Our results indicated that the linear attenuation coefficients of the breast-equivalent liquid phantoms match those of the target material. Comparison between measured and known breast density data shows a linear correlation with a slope close to 1 and a non-zero intercept of 7%, while plastic phantoms showed a slope of 0.6 and a non-zero intercept of 8%. Breast density results derived from the liquid calibration phantoms showed higher accuracy than those derived from the plastic phantoms for different breast thicknesses and various tube voltages. We performed experimental phantom studies using liquid phantoms and then compared the computed breast density with those obtained using a bovine tissue model. The experimental data and the known values were in good correlation with a slope close to 1 (˜1.1). In conclusion, our results indicate that liquid phantoms are a reliable alternative for calibration in dual-energy mammography and better reproduce the chemical properties of the target material.

  4. Carrier concentration dependence of donor activation energy in n-type GaN epilayers grown on Si (1 1 1) by plasma-assisted MBE

    SciTech Connect

    Kumar, Mahesh; Bhat, Thirumaleshwara N.; Roul, Basanta; Rajpalke, Mohana K.; Kalghatgi, A.T.; Krupanidhi, S.B.

    2012-06-15

    Highlights: ► The n-type GaN layers were grown by plasma-assisted molecular beam epitaxy. ► The optical characteristics of a donor level in Si-doped GaN were studied. ► Activation energy of a Si-related donor was estimated from temperature dependent PL measurements. ► PL peak positions, FWHM of PL and activation energies are found to be proportional to the cube root of carrier density. ► The involvement of donor levels is supported by the temperature-dependent electron concentration measurements. -- Abstract: The n-type GaN layers were grown by plasma-assisted MBE and either intentionally doped with Si or unintentionally doped. The optical characteristics of a donor level in Si-doped, GaN were studied in terms of photoluminescence (PL) spectroscopy as a function of electron concentration. Temperature dependent PL measurements allowed us to estimate the activation energy of a Si-related donor from temperature-induced decay of PL intensity. PL peak positions, full width at half maximum of PL and activation energies are found to be proportional to the cube root of carrier density. The involvement of donor levels is supported by the temperature-dependent electron concentration measurements.

  5. Light yield and energy transfer in a new Gd-loaded liquid scintillator

    NASA Astrophysics Data System (ADS)

    Aberle, C.; Buck, C.; Hartmann, F. X.; Schönert, S.

    2011-11-01

    We investigate a new gadolinium-loaded organic liquid scintillator which is designed to detect electron antineutrinos. A model has been developed to account for the various energy transfer paths possible in a liquid scintillator with multiple solvents, one fluor and a quenching component. Experimental light yield measurements were carried out to determine the relative rates for the energy transfers included in the model. Model predictions were used to tune the luminescent properties of the Gd-loaded target scintillator and the unloaded Gamma Catcher scintillator for the reactor neutrino experiment Double Chooz.

  6. Ionic liquid enabled FeS2 for high-energy-density lithium-ion batteries.

    PubMed

    Evans, Tyler; Piper, Daniela Molina; Kim, Seul Cham; Han, Sang Sub; Bhat, Vinay; Oh, Kyu Hwan; Lee, Se-Hee

    2014-11-19

    High-energy-density FeS2 cathodes en-abled by a bis(trifluoromethanesulfonyl)imide (TFSI-) anion-based room temperature ionic liquid (RTIL) electrolyte are demonstrated. A TFSI-based ionic liquid (IL) significantly mitigates polysulfide dissolution, and therefore the parasitic redox shuttle mechanism, that plagues sulfur-based electrode chemistries. FeS2 stabilization with a TFSI(-) -based IL results in one of the highest energy density cathodes, 542 W h kg(-1) (normalized to cathode composite mass), reported to date. PMID:25236752

  7. Energy surface and minimum energy paths for Fréedericksz transitions in bistable cholesteric liquid crystals

    NASA Astrophysics Data System (ADS)

    Ivanov, A. V.; Bessarab, P. F.; Aksenova, E. V.; Romanov, V. P.; Uzdin, V. M.

    2016-04-01

    The multidimensional energy surface of a cholesteric liquid crystal in a planar cell is investigated as a function of spherical coordinates determining the director orientation. Minima on the energy surface correspond to the stable states with particular director distribution. External electric and magnetic fields deform the energy surface and positions of minima. It can lead to the transitions between states, known as the Fréedericksz effect. Transitions can be continuous or discontinuous depending on parameters of the liquid crystal which determine an energy surface. In a case of discontinuous transition when a barrier between stable states is comparable with the thermal energy, the activation transitions may occur, and it leads to the modification of characteristics of the Fréedericksz effect with temperature without explicit temperature dependencies of liquid crystal parameters. A minimum energy path between stable states on the energy surface for the Fréedericksz transition is found using the geodesic nudged elastic band method. Knowledge of this path, which has maximal statistical weight among all other paths, gives the information about a barrier between stable states and configuration of director orientation during the transition. It also allows one to estimate the stability of states with respect to the thermal fluctuations and their lifetime when the system is close to the Fréedericksz transition.

  8. Hydrophilic interaction liquid chromatography-tandem mass spectrometry quantitative method for the cellular analysis of varying structures of gemini surfactants designed as nanomaterial drug carriers.

    PubMed

    Donkuru, McDonald; Michel, Deborah; Awad, Hanan; Katselis, George; El-Aneed, Anas

    2016-05-13

    Diquaternary gemini surfactants have successfully been used to form lipid-based nanoparticles that are able to compact, protect, and deliver genetic materials into cells. However, what happens to the gemini surfactants after they have released their therapeutic cargo is unknown. Such knowledge is critical to assess the quality, safety, and efficacy of gemini surfactant nanoparticles. We have developed a simple and rapid liquid chromatography electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) method for the quantitative determination of various structures of gemini surfactants in cells. Hydrophilic interaction liquid chromatography (HILIC) was employed allowing for a short simple isocratic run of only 4min. The lower limit of detection (LLOD) was 3ng/mL. The method was valid to 18 structures of gemini surfactants belonging to two different structural families. A full method validation was performed for two lead compounds according to USFDA guidelines. The HILIC-MS/MS method was compatible with the physicochemical properties of gemini surfactants that bear a permanent positive charge with both hydrophilic and hydrophobic elements within their molecular structure. In addition, an effective liquid-liquid extraction method (98% recovery) was employed surpassing previously used extraction methods. The analysis of nanoparticle-treated cells showed an initial rise in the analyte intracellular concentration followed by a maximum and a somewhat more gradual decrease of the intracellular concentration. The observed intracellular depletion of the gemini surfactants may be attributable to their bio-transformation into metabolites and exocytosis from the host cells. Obtained cellular data showed a pattern that grants additional investigations, evaluating metabolite formation and assessing the subcellular distribution of tested compounds. PMID:27086283

  9. Temperature effects on the energy bandgap and conductivity effective masses of charge carriers in lead telluride from first-principles calculations

    NASA Astrophysics Data System (ADS)

    Venkatapathi, S.; Dong, B.; Hin, C.

    2014-07-01

    We determined the temperature effects on the electronic properties of lead telluride (PbTe) such as the energy bandgap and the effective masses of charge carriers by incorporating the structural changes of the material with temperature using ab-initio density functional theory (DFT) calculations. Though the first-principles DFT calculations are done at absolute zero temperatures, by incorporating the lattice thermal expansion and the distortion of Pb2+ ions from the equilibrium positions, we could determine the stable structural configuration of the PbTe system at different temperatures.

  10. Temperature effects on the energy bandgap and conductivity effective masses of charge carriers in lead telluride from first-principles calculations

    SciTech Connect

    Venkatapathi, S. Dong, B.; Hin, C.

    2014-07-07

    We determined the temperature effects on the electronic properties of lead telluride (PbTe) such as the energy bandgap and the effective masses of charge carriers by incorporating the structural changes of the material with temperature using ab-initio density functional theory (DFT) calculations. Though the first-principles DFT calculations are done at absolute zero temperatures, by incorporating the lattice thermal expansion and the distortion of Pb{sup 2+} ions from the equilibrium positions, we could determine the stable structural configuration of the PbTe system at different temperatures.

  11. High Energy Cutting and Stripping Utilizing Liquid Nitrogen

    NASA Technical Reports Server (NTRS)

    Hume, Howard; Noah, Donald E.; Hayes, Paul W.

    2005-01-01

    The Aerospace Industry has endeavored for decades to develop hybrid materials that withstand the rigors of mechanized flight both within our atmosphere and beyond. The development of these high performance materials has led to the need for environmentally friendly technologies for material re-work and removal. The NitroJet(TM) is a fluid jet technology that represents an evolution of the widely used, large-scale water jet fluid jet technology. It involves the amalgamation of fluid jet technology and cryogenics technology to create a new capability that is applicable where water jet or abrasive jet (water jet plus entrained abrasive) are not suitable or acceptable because of technical constraints such as process or materials compatibility, environmental concerns and aesthetic or legal requirements. The NitroJet(TM) uses ultra high-pressure nitrogen to cut materials, strip numerous types of coatings such as paint or powder coating, clean surfaces and profile metals. Liquid nitrogen (LN2) is used as the feed stream and is pressurized in two stages. The first stage pressurizes sub cooled LN2 to an intermediate pressure of between 15,000 and 20,000 psi at which point the temperature of the LN2 is about -250 F. The discharge from this stage is then introduced as feed to a dual intensifier system, which boosts the pressure from 15,000 - 20,000 psi up to the maximum operating pressure of 55,000 psi. A temperature of about -220 F is achieved at which point the nitrogen is supercritical. In this condition the nitrogen cuts, strips and abrades much like ultra high-pressure water would but without any residual liquid to collect, remove or be contaminated. Once the nitrogen has performed its function it harmlessly flashes back into the atmosphere as pure nitrogen gas. The system uses heat exchangers to control and modify the temperature of the various intake and discharge nitrogen streams. Since the system is hydraulically operated, discharge pressures can be easily varied over

  12. Exotic low-energy separation in 1D quantum liquids

    SciTech Connect

    Carmelo, J.M.P.; Neto, A.H.C.; Campbell, D.K.

    1995-05-01

    We define the low-energy separation of the Hubbard chain in a magnetic field and chemical potential in terms of two {open_quotes}c{close_quotes} and {open_quotes}s{close_quotes} bosonic algebras. This generalizes the usual charge-spin separation, which is recovered in the limit of zero magnetization only. The corresponding pseudoparticle bosonization follows directly from the perturbative character of the pseudoparticle operator basis.

  13. Eco-friendly Energy Storage System: Seawater and Ionic Liquid Electrolyte.

    PubMed

    Kim, Jae-Kwang; Mueller, Franziska; Kim, Hyojin; Jeong, Sangsik; Park, Jeong-Sun; Passerini, Stefano; Kim, Youngsik

    2016-01-01

    As existing battery technologies struggle to meet the requirements for widespread use in the field of large-scale energy storage, novel concepts are urgently needed concerning batteries that have high energy densities, low costs, and high levels of safety. Here, a novel eco-friendly energy storage system (ESS) using seawater and an ionic liquid is proposed for the first time; this represents an intermediate system between a battery and a fuel cell, and is accordingly referred to as a hybrid rechargeable cell. Compared to conventional organic electrolytes, the ionic liquid electrolyte significantly enhances the cycle performance of the seawater hybrid rechargeable system, acting as a very stable interface layer between the Sn-C (Na storage) anode and the NASICON (Na3 Zr2 Si2 PO12) ceramic solid electrolyte, making this system extremely promising for cost-efficient and environmentally friendly large-scale energy storage. PMID:26611916

  14. Energy-efficient regenerative liquid desiccant drying process

    DOEpatents

    Ko, Suk M.; Grodzka, Philomena G.; McCormick, Paul O.

    1980-01-01

    This invention relates to the use of desiccants in conjunction with an open oop drying cycle and a closed loop drying cycle to reclaim the energy expended in vaporizing moisture in harvested crops. In the closed loop cycle, the drying air is brought into contact with a desiccant after it exits the crop drying bin. Water vapor in the moist air is absorbed by the desiccant, thus reducing the relative humidity of the air. The air is then heated by the used desiccant and returned to the crop bin. During the open loop drying cycle the used desiccant is heated (either fossil or solar energy heat sources may be used) and regenerated at high temperature, driving water vapor from the desiccant. This water vapor is condensed and used to preheat the dilute (wet) desiccant before heat is added from the external source (fossil or solar). The latent heat of vaporization of the moisture removed from the desiccant is reclaimed in this manner. The sensible heat of the regenerated desiccant is utilized in the open loop drying cycle. Also, closed cycle operation implies that no net energy is expended in heating drying air.

  15. On the transfer of energy to an unstable liquid jet in a coflowing compressible airstream

    NASA Technical Reports Server (NTRS)

    Li, Hsi-Shang; Kelly, Robert E.

    1993-01-01

    The transfer of energy from a compressible airstream to a coflowing unstable liquid jet via the pressure perturbation at the interface is studied as the Mach number varies continuously from subsonic to supersonic values. The 'lift' component of the pressure perturbation has been demonstrated to predominate up to slightly supersonic free-stream Mach numbers, after which the 'drag' component predominates.

  16. Step free energies at faceted solid-liquid interfaces from equilibrium molecular dynamics simulations.

    PubMed

    Frolov, T; Asta, M

    2012-12-01

    In this work a method is proposed for computing step free energies for faceted solid-liquid interfaces based on atomistic simulations. The method is demonstrated in an application to (111) interfaces in elemental Si, modeled with the classical Stillinger-Weber potential. The approach makes use of an adiabatic trapping procedure, and involves simulations of systems with coexisting solid and liquid phases separated by faceted interfaces containing islands with different sizes, for which the corresponding equilibrium temperatures are computed. We demonstrate that the calculated coexistence temperature is strongly affected by the geometry of the interface. We find that island radius is inversely proportional to superheating, allowing us to compute the step free energy by fitting simulation data within the formalism of classical nucleation theory. The step free energy value is computed to be γ(st) = 0.103 ± 0.005 × 10(-10) J/m. The approach outlined in this work paves the way to the calculation of step free energies relevant to the solidification of faceted crystals from liquid mixtures, as encountered in nanowire growth by the vapor-liquid-solid mechanism and in alloy casting. The present work also shows that at low undercoolings the Stillinger-Weber interatomic potential for Si tends to crystallize in the wurtzite, rather than the diamond-cubic structure. PMID:23231218

  17. Enhanced energy transfer efficiency and stability of europium β-diketonate complex in ionic liquid-based lyotropic liquid crystals.

    PubMed

    Yi, Sijing; Wang, Jiao; Chen, Xiao

    2015-08-21

    Luminescent materials from europium β-diketonate complex in ionic liquids (ILs) could achieve enhanced luminescence efficiencies and photostabilities. However, the question of how to provide a feasible and environmentally-friendly way to distribute these lanthanide complexes uniformly and stably within IL-based matrix remains a significant challenge. Here, a soft luminescent material from IL-mediated lyotropic liquid crystals (LLCs) doped with [Bmim][Eu(TTA)4] (Bmim = 1-butyl-3-methyl imidazolium, TTA = 2-thenoyltrifluoroacetone) has been constructed by a convenient self-assembling method. The hexagonal or lamellar LLC phases could be identified by small-angle X-ray scattering (SAXS) measurements. All LLC samples exhibited intense red luminescence upon exposure to ultraviolet radiation. The good dispersibility of the complexes in LLC matrices and their good photostability (as in ILs) was verified by steady-state luminescence spectroscopy. The isolated and unique characteristics of the microenvironment within the LLCs were noteworthy to decrease the nonradiative deactivation of the excited states, thereby allowing more efficient energy transfer and longer lifetimes than those in pure complex or IL solutions. Both the luminescent property and the stability of the LLC materials were different in different phase structures, the complexes behaving better in the lamellar phase than in the hexagonal one. The findings reported herein will not only present an easy way to design novel luminescent lanthanide β-diketonate soft materials, but also provide a useful reference to better understand the LLC phase structure effects on the luminescence properties. PMID:26190789

  18. What Is Carrier Screening?

    MedlinePlus

    ... you want to learn. Search form Search Carrier screening You are here Home Testing & Services Testing for ... help you make the decision. What Is Carrier Screening? Carrier screening checks if a person is a " ...

  19. Determination of the mean solid-liquid interface energy of pivalic acid

    NASA Technical Reports Server (NTRS)

    Singh, N. B.; Gliksman, M. E.

    1989-01-01

    A high-confidence solid-liquid interfacial energy is determined for an anisotropic material. A coaxial composite having a cylindrical specimen chamber geometry provides a thermal gradient with an axial heating wire. The surface energy is derived from measurements of grain boundary groove shapes. Applying this method to pivalic acid, a surface energy of 2.84 erg/sq cm was determined with a total systematic and random error less than 10 percent. The value of interfacial energy corresponds to 24 percent of the latent heat of fusion per molecule.

  20. Solid state cloaking for electrical charge carrier mobility control

    DOEpatents

    Zebarjadi, Mona; Liao, Bolin; Esfarjani, Keivan; Chen, Gang

    2015-07-07

    An electrical mobility-controlled material includes a solid state host material having a controllable Fermi energy level and electrical charge carriers with a charge carrier mobility. At least one Fermi level energy at which a peak in charge carrier mobility is to occur is prespecified for the host material. A plurality of particles are distributed in the host material, with at least one particle disposed with an effective mass and a radius that minimize scattering of the electrical charge carriers for the at least one prespecified Fermi level energy of peak charge carrier mobility. The minimized scattering of electrical charge carriers produces the peak charge carrier mobility only at the at least one prespecified Fermi level energy, set by the particle effective mass and radius, the charge carrier mobility being less than the peak charge carrier mobility at Fermi level energies other than the at least one prespecified Fermi level energy.

  1. High energy supercapattery with an ionic liquid solution of LiClO4.

    PubMed

    Yu, Linpo; Chen, George Z

    2016-08-15

    A supercapattery combining an ideally polarized capacitor-like electrode and a battery-like electrode is demonstrated theoretically and practically using an ionic liquid electrolyte containing 1-butyl-1-methylpyrrolidinium tri(pentafluoroethyl)trifluorophosphate (BMPyrrFAP), gamma-butyrolactone (γ-GBL) and LiClO4. The electrochemical deposition and dissolution of lithium metal on a platinum and glass carbon electrode were investigated in this ionic liquid solution. The CVs showed that the fresh electrochemically deposited lithium metal was stable in the electrolyte, which encouraged the investigation of this ionic liquid solution in a supercapattery with a lithium battery negative electrode. The active material counted specific energy of the supercapattery based on a lithium negative electrode and an activated carbon (Act-C) positive electrode could reach 230 W h kg(-1) under a galvanostatic charge-discharge current density of 1 mA cm(-2). The positive electrode material (Act-C) was also investigated by CV, AC impedance, SEM and BET. The non-uniform particle size and micropores dominated porous structure of the Act-C enabled its electric double layer capacitor (EDLC) behavior in the ionic liquid solution. The measured specific capacitance of the Act-C in this ionic liquid solution is higher than the same Act-C in aqueous solution, which indicates the Act-C can also perform well in the ionic liquid electrolyte. PMID:27228429

  2. Probing battery chemistry with liquid cell electron energy loss spectroscopy.

    PubMed

    Unocic, Raymond R; Baggetto, Loïc; Veith, Gabriel M; Aguiar, Jeffery A; Unocic, Kinga A; Sacci, Robert L; Dudney, Nancy J; More, Karren L

    2015-11-25

    We demonstrate the ability to apply electron energy loss spectroscopy (EELS) to follow the chemistry and oxidation states of LiMn2O4 and Li4Ti5O12 battery electrodes within a battery solvent. This is significant as the use and importance of in situ electrochemical cells coupled with a scanning/transmission electron microscope (S/TEM) has expanded and been applied to follow changes in battery chemistry during electrochemical cycling. We discuss experimental parameters that influence measurement sensitivity and provide a framework to apply this important analytical method to future in situ electrochemical studies. PMID:26404766

  3. Probing Battery Chemistry with Liquid Cell Electron Energy Loss Spectroscopy

    SciTech Connect

    Unocic, Raymond R.; Baggetto, Loic; Veith, Gabriel M.; Aguiar, Jeffery A.; Unocic, Kinga A.; Sacci, Robert L.; Dudney, Nancy J.; More, Karren L.

    2015-11-25

    We demonstrate the ability to apply electron energy loss spectroscopy (EELS) to follow the chemistry and oxidation states of LiMn2O4 and Li4Ti5O12 battery electrodes within a battery solvent. The use and importance of in situ electrochemical cells coupled with a scanning/transmission electron microscope (S/TEM) has expanded and been applied to follow changes in battery chemistry during electrochemical cycling. Furthermore, we discuss experimental parameters that influence measurement sensitivity and provide a framework to apply this important analytical method to future in situ electrochemical studies.

  4. Distribution of binding energies of a water molecule in the water liquid-vapor interface

    SciTech Connect

    Chempath, Shaji; Pratt, Lawrence R

    2008-01-01

    Distributions of binding energies of a water molecule in the water liquid-vapor interface are obtained on the basis of molecular simulation with the SPC/E model of water. These binding energies together with the observed interfacial density profile are used to test a minimally conditioned Gaussian quasi-chemical statistical thermodynamic theory. Binding energy distributions for water molecules in that interfacial region clearly exhibit a composite structure. A minimally conditioned Gaussian quasi-chemical model that is accurate for the free energy of bulk liquid water breaks down for water molecules in the liquid-vapor interfacial region. This breakdown is associated with the fact that this minimally conditioned Gaussian model would be inaccurate for the statistical thermodynamics of a dilute gas. Aggressive conditioning greatly improves the performance of that Gaussian quasi-chemical model. The analogy between the Gaussian quasi-chemical model and dielectric models of hydration free energies suggests that naive dielectric models without the conditioning features of quasi-chemical theory will be unreliable for these interfacial problems. Multi-Gaussian models that address the composite nature of the binding energy distributions observed in the interfacial region might provide a mechanism for correcting dielectric models for practical applications.

  5. Statistical mechanics model for the transit free energy of monatomic liquids

    NASA Astrophysics Data System (ADS)

    Wallace, Duane C.; Chisolm, Eric D.; Bock, N.; de Lorenzi-Venneri, G.

    2010-04-01

    In applying vibration-transit (V-T) theory of liquid dynamics to the thermodynamic properties of monatomic liquids, the point has been reached where an improved model is needed for the small (˜10%) transit contribution. Toward this goal, an analysis of the available high-temperature experimental entropy data for elemental liquids was recently completed [D. C. Wallace, E. D. Chisolm, and N. Bock, Phys. Rev. E 79, 051201 (2009)]. This analysis yields a common curve of transit entropy vs T/θtr , where T is temperature and θtr is a scaling temperature for each element. In the present paper, a statistical mechanics model is constructed for the transit partition function, and is calibrated to the experimental transit entropy curve. The model has two scalar parameters, and captures the temperature scaling of experiment. The calibrated model fits the experimental liquid entropy to high accuracy at all temperatures. With no additional parameters, the model also agrees with both experiment and molecular dynamics for the internal energy vs. T for Na. With the calibrated transit model, V-T theory provides equations subject to ab initio evaluation for thermodynamic properties of monatomic liquids. This will allow the range of applicability of the theory, and its overall accuracy, to be determined. More generally, the hypothesis of V-T theory, which divides the many-atom potential energy valleys into random and symmetric classes, can also be tested for its application beyond monatomic systems.

  6. EMCASS: Expert Motor Carrier Selection System

    SciTech Connect

    Teeters, S.W.

    1991-03-13

    The Expert Motor Carrier Selection System (EMCASS) was designed as a Knowledge-Based System to help in traffic management at Martin Marietta Energy Systems, Inc. (Energy Systems). The primary function of the system is to suggest the optimal motor carrier(s) for a given freight shipment to or from Energy Systems. The system accepts a zip code (destination or origin) from the user, a shipment weight, and other related information in some cases. EMCASS then suggests the best carrier for that shipment, and journals the results. The objective of this project is to distribute the knowledge of the company's traffic managers, and to emulate their decision processes as closely as possible.

  7. Local Orientational Order in Liquids Revealed by Resonant Vibrational Energy Transfer

    NASA Astrophysics Data System (ADS)

    Panman, M. R.; Shaw, D. J.; Ensing, B.; Woutersen, S.

    2014-11-01

    We demonstrate that local orientational ordering in a liquid can be observed in the decay of the vibrational anisotropy caused by resonant transfer of vibrational excitations between its constituent molecules. We show that the functional form of this decay is determined by the (distribution of) angles between the vibrating bonds of the molecules between which energy transfer occurs, and that the initial drop in the decay reflects the average angle between nearest neighbors. We use this effect to observe the difference in local orientational ordering in the two hydrogen-bonded liquids ethanol and N -methylacetamide.

  8. Nonequilibrium study of the intrinsic free-energy profile across a liquid-vapour interface.

    PubMed

    Braga, Carlos; Muscatello, Jordan; Lau, Gabriel; Müller, Erich A; Jackson, George

    2016-01-28

    We calculate an atomistically detailed free-energy profile across a heterogeneous system using a nonequilibrium approach. The path-integral formulation of Crooks fluctuation theorem is used in conjunction with the intrinsic sampling method to calculate the free-energy profile for the liquid-vapour interface of the Lennard-Jones fluid. Free-energy barriers are found corresponding to the atomic layering in the liquid phase as well as a barrier associated with the presence of an adsorbed layer as revealed by the intrinsic density profile. Our findings are in agreement with profiles calculated using Widom's potential distribution theorem applied to both the average and the intrinsic profiles as well as the literature values for the excess chemical potential. PMID:26827224

  9. An electrically switchable surface free energy on a liquid crystal and polymer composite film

    NASA Astrophysics Data System (ADS)

    Lin, Yi-Hsin; Chu, Ting-Yu; Tsou, Yu-Shih; Chang, Kai-Han; Chiu, Ya-Ping

    2012-12-01

    An electrically switchable surface free energy on a liquid crystal and polymer composite film (LCPCF) resulting from the orientations of liquid crystal molecules is investigated. By modification of Cassie's model and the measurement based on the Chibowski's film pressure model (E. Chibowski, Adv. Colloid Interface Sci. 103, 149 (2003)), the surface free energy of LCPCF is electrically switchable from 36×10-3J/ m2 to 51×10-3J/ m2 while the average tilt angle of LC molecules changes from 0° to 32° with the applied pulsed voltage. The switchable surface free energy of LCPCF can help us to design biosensors and photonics devices, such as electro-optical switches, blood sensors, and sperm testers.

  10. Energy Budget of Liquid Drop Impact at Maximum Spreading: Numerical Simulations and Experiments.

    PubMed

    Lee, Jae Bong; Derome, Dominique; Dolatabadi, Ali; Carmeliet, Jan

    2016-02-01

    The maximum spreading of an impinging droplet on a rigid surface is studied for low to high impact velocity, until the droplet starts splashing. We investigate experimentally and numerically the role of liquid properties, such as surface tension and viscosity, on drop impact using three liquids. It is found that the use of the experimental dynamic contact angle at maximum spreading in the Kistler model, which is used as a boundary condition for the CFD-VOF calculation, gives good agreement between experimental and numerical results. Analytical models commonly used to predict the boundary layer thickness and time at maximum spreading are found to be less correct, meaning that energy balance models relying on these relations have to be considered with care. The time of maximum spreading is found to depend on both the impact velocity and surface tension, and neither dependency is predicted correctly in common analytical models. The relative proportion of the viscous dissipation in the total energy budget increases with impact velocity with respect to surface energy. At high impact velocity, the contribution of surface energy, even before splashing, is still substantial, meaning that both surface energy and viscous dissipation have to be taken into account, and scaling laws depending only on viscous dissipation do not apply. At low impact velocity, viscous dissipation seems to play an important role in low-surface-tension liquids such as ethanol. PMID:26745364

  11. Bimodal behaviour of charge carriers in graphene induced by electric double layer

    NASA Astrophysics Data System (ADS)

    Tsai, Sing-Jyun; Yang, Ruey-Jen

    2016-07-01

    A theoretical investigation is performed into the electronic properties of graphene in the presence of liquid as a function of the contact area ratio. It is shown that the electric double layer (EDL) formed at the interface of the graphene and the liquid causes an overlap of the conduction bands and valance bands and increases the density of state (DOS) at the Fermi energy (EF). In other words, a greater number of charge carriers are induced for transport and the graphene changes from a semiconductor to a semimetal. In addition, it is shown that the dependence of the DOS at EF on the contact area ratio has a bimodal distribution which responses to the experimental observation, a pinnacle curve. The maximum number of induced carriers is expected to occur at contact area ratios of 40% and 60%. In general, the present results indicate that modulating the EDL provides an effective means of tuning the electronic properties of graphene in the presence of liquid.

  12. Equation of state for compressed liquids and their mixtures from the cohesive energy density

    NASA Astrophysics Data System (ADS)

    Boushehri, A.; Mason, E. A.

    1993-07-01

    A procedure is presented, based on statistical-mechanical theory, for predicting the equation of state of compressed normal liquids and their mixtures from two scaling constants that are available from measurements at ordinary pressures and temperatures. The theoretical equation of state is that of Ihm, Song, and Mason, and the two constants are the enthalpy of vaporization and the liquid density at the triple point, which are related to the cohesive energy density of regular solution theory. The procedure is tested on a number of substances ranging in complexity from Ar and CO2 to n-heptane and toluene. The results indicate that the liquid density at any pressure and temperature can be predicted within about 5%, over the range from T tp to T c and up to the freezing line. Possible methods of determining the scaling constants are discussed, as well as other possible choices for scaling constants.

  13. Optoelectronic characterization of carrier extraction in a hot carrier photovoltaic cell structure

    NASA Astrophysics Data System (ADS)

    Dimmock, James A. R.; Kauer, Matthias; Smith, Katherine; Liu, Huiyun; Stavrinou, Paul N.; Ekins-Daukes, Nicholas J.

    2016-07-01

    A hot carrier photovoltaic cell requires extraction of electrons on a timescale faster than they can lose energy to the lattice. We optically and optoelectronically characterize two resonant tunneling structures, showing their compatability with hot carrier photovoltaic operation, demonstrating structural and carrier extraction properties necessary for such a device. In particular we use time resolved and temperature dependent photoluminescence to determine extraction timescales and energy levels in the structures and demonstrate fast carrier extraction by tunneling. We also show that such devices are capable of extracting photo-generated electrons at high carrier densities, with an open circuit voltage in excess of 1 V.

  14. Status and future opportunities for conversion of synthesis gas to liquid energy fuels: Final report

    SciTech Connect

    Mills, G

    1993-05-01

    The manufacture of liquid energy fuels from syngas (a mixture of H{sub 2} and CO, usually containing CO{sub 2}) is of growing importance and enormous potential because: (1) Abundant US supplies of coal, gas, and biomass can be used to provide the needed syngas. (2) The liquid fuels produced, oxygenates or hydrocarbons, can help lessen environmental pollution. Indeed, oxygenates are required to a significant extent by the Clean Air Act Amendments (CAAA) of 1990. (3) Such liquid synfuels make possible high engine efficiencies because they have high octane or cetane ratings. (4) There is new, significantly improved technology for converting syngas to liquid fuels and promising opportunities for further improvements. This is the subject of this report. The purpose of this report is to provide an account and evaluative assessment of advances in the technology for producing liquid energy fuels from syngas and to suggest opportunities for future research deemed promising for practical processes. Much of the improved technology for selective synthesis of desired fuels from syngas has resulted from advances in catalytic chemistry. However, novel process engineering has been particularly important recently, utilizing known catalysts in new configurations to create new catalytic processes. This report is an update of the 1988 study Catalysts for Fuels from Syngas: New Directions for Research (Mills 1988), which is included as Appendix A. Technology for manufacture of syngas is not part of this study. The manufacture of liquid synfuels is capital intensive. Thus, in evaluating advances in fuels technology, focus is on the potential for improved economics, particularly on lowering plant investment costs. A second important criteria is the potential for environmental benefits. The discussion is concerned with two types of hydrocarbon fuels and three types of oxygenate fuels that can be synthesized from syngas. Seven alternative reaction pathways are involved.

  15. Status and future opportunities for conversion of synthesis gas to liquid energy fuels: Final report

    SciTech Connect

    Mills, G. . Center for Catalytic Science and Technology)

    1993-05-01

    The manufacture of liquid energy fuels from syngas (a mixture of H[sub 2] and CO, usually containing CO[sub 2]) is of growing importance and enormous potential because: (1) Abundant US supplies of coal, gas, and biomass can be used to provide the needed syngas. (2) The liquid fuels produced, oxygenates or hydrocarbons, can help lessen environmental pollution. Indeed, oxygenates are required to a significant extent by the Clean Air Act Amendments (CAAA) of 1990. (3) Such liquid synfuels make possible high engine efficiencies because they have high octane or cetane ratings. (4) There is new, significantly improved technology for converting syngas to liquid fuels and promising opportunities for further improvements. This is the subject of this report. The purpose of this report is to provide an account and evaluative assessment of advances in the technology for producing liquid energy fuels from syngas and to suggest opportunities for future research deemed promising for practical processes. Much of the improved technology for selective synthesis of desired fuels from syngas has resulted from advances in catalytic chemistry. However, novel process engineering has been particularly important recently, utilizing known catalysts in new configurations to create new catalytic processes. This report is an update of the 1988 study Catalysts for Fuels from Syngas: New Directions for Research (Mills 1988), which is included as Appendix A. Technology for manufacture of syngas is not part of this study. The manufacture of liquid synfuels is capital intensive. Thus, in evaluating advances in fuels technology, focus is on the potential for improved economics, particularly on lowering plant investment costs. A second important criteria is the potential for environmental benefits. The discussion is concerned with two types of hydrocarbon fuels and three types of oxygenate fuels that can be synthesized from syngas. Seven alternative reaction pathways are involved.

  16. Microscopic origins of the terahertz carrier relaxation and cooling dynamics in graphene

    PubMed Central

    Mihnev, Momchil T.; Kadi, Faris; Divin, Charles J.; Winzer, Torben; Lee, Seunghyun; Liu, Che-Hung; Zhong, Zhaohui; Berger, Claire; de Heer, Walt A.; Malic, Ermin; Knorr, Andreas; Norris, Theodore B.

    2016-01-01

    The ultrafast dynamics of hot carriers in graphene are key to both understanding of fundamental carrier–carrier interactions and carrier–phonon relaxation processes in two-dimensional materials, and understanding of the physics underlying novel high-speed electronic and optoelectronic devices. Many recent experiments on hot carriers using terahertz spectroscopy and related techniques have interpreted the variety of observed signals within phenomenological frameworks, and sometimes invoke extrinsic effects such as disorder. Here, we present an integrated experimental and theoretical programme, using ultrafast time-resolved terahertz spectroscopy combined with microscopic modelling, to systematically investigate the hot-carrier dynamics in a wide array of graphene samples having varying amounts of disorder and with either high or low doping levels. The theory reproduces the observed dynamics quantitatively without the need to invoke any fitting parameters, phenomenological models or extrinsic effects such as disorder. We demonstrate that the dynamics are dominated by the combined effect of efficient carrier–carrier scattering, which maintains a thermalized carrier distribution, and carrier–optical–phonon scattering, which removes energy from the carrier liquid. PMID:27221060

  17. Roles of Energy Dissipation in a Liquid-Solid Transition of Out-of-Equilibrium Systems

    NASA Astrophysics Data System (ADS)

    Komatsu, Yuta; Tanaka, Hajime

    2015-07-01

    Self-organization of active matter as well as driven granular matter in nonequilibrium dynamical states has attracted considerable attention not only from the fundamental and application viewpoints but also as a model to understand the occurrence of such phenomena in nature. These systems share common features originating from their intrinsically out-of-equilibrium nature, and how energy dissipation affects the state selection in such nonequilibrium states remains elusive. As a simple model system, we consider a nonequilibrium stationary state maintained by continuous energy input, relevant to industrial processing of granular materials by vibration and/or flow. More specifically, we experimentally study roles of dissipation in self-organization of a driven granular particle monolayer. We find that the introduction of strong inelasticity entirely changes the nature of the liquid-solid transition from two-step (nearly) continuous transitions (liquid-hexatic-solid) to a strongly discontinuous first-order-like one (liquid-solid), where the two phases with different effective temperatures can coexist, unlike thermal systems, under a balance between energy input and dissipation. Our finding indicates a pivotal role of energy dissipation and suggests a novel principle in the self-organization of systems far from equilibrium. A similar principle may apply to active matter, which is another important class of out-of-equilibrium systems. On noting that interaction forces in active matter, and particularly in living systems, are often nonconservative and dissipative, our finding may also shed new light on the state selection in these systems.

  18. Ab Initio Investigation of Cation Proton Affinity and Proton Transfer Energy for Energetic Ionic Liquids.

    PubMed

    Carlin, Caleb M; Gordon, Mark S

    2016-08-01

    Protonation of the anion in an ionic liquid plays a key role in the hypergolic reaction between ionic liquids and oxidizers such as white fuming nitric acid. To investigate the influence of the cation on the protonation reaction, the deprotonation energy of a set of cations has been calculated at the MP2 level of theory. Specifically, guanidinium, dimethyltriazanium, triethylamine, N-ethyl-N-methyl-pyrrolidinium, N-ethyl-pyridinium, 1,4-dimethyl-1,2,4-triazolium, 1-ethyl-4-methyl-1,2,4-triazolium, and 1-butyl-4-methyl-1,2,4-triazolium were studied. In addition, the net proton transfer energies from the cations to a set of previously studied anions was calculated, demonstrating an inverse correlation between the net proton transfer energy and the likelihood that the cation/anion combination will react hypergolically with white fuming nitric acid. It is suggested that this correlation occurs due to a balance between the energy released by the proton transfer and the rate of proton transfer as determined by the ionicity of the ionic liquid. PMID:27397644

  19. Energy landscape view of phase transitions and slow dynamics in thermotropic liquid crystals

    PubMed Central

    Chakrabarti, Dwaipayan; Bagchi, Biman

    2006-01-01

    Thermotropic liquid crystals are known to display rich phase behavior on temperature variation. Although the nematic phase is orientationally ordered but translationally disordered, a smectic phase is characterized by the appearance of a partial translational order in addition to a further increase in orientational order. In an attempt to understand the interplay between orientational and translational order in the mesophases that thermotropic liquid crystals typically exhibit upon cooling from the high-temperature isotropic phase, we investigate the potential energy landscapes of a family of model liquid crystalline systems. The configurations of the system corresponding to the local potential energy minima, known as the inherent structures, are determined from computer simulations across the mesophases. We find that the depth of the potential energy minima explored by the system along an isochor grows through the nematic phase as temperature drops in contrast to its insensitivity to temperature in the isotropic and smectic phases. The onset of the growth of the orientational order in the parent phase is found to induce a translational order, resulting in a smectic-like layer in the underlying inherent structures; the inherent structures, surprisingly, never seem to sustain orientational order alone if the parent nematic phase is sandwiched between the high-temperature isotropic phase and the low-temperature smectic phase. The Arrhenius temperature dependence of the orientational relaxation time breaks down near the isotropic–nematic transition. We find that this breakdown occurs at a temperature below which the system explores increasingly deeper potential energy minima. PMID:16648269

  20. Liquid-based electrostatic energy harvester with high sensitivity to human physical motion

    NASA Astrophysics Data System (ADS)

    Choi, Dong-Hoon; Han, Chang-Hoon; Kim, Hyun-Don; Yoon, Jun-Bo

    2011-12-01

    This paper presents a new liquid-based electrostatic energy harvester that converts the mechanical energy of human-motion-induced vibrations to electrical energy. The basic design uses a conducting liquid to enhance sensitivity to human motion, the frequency of which is typically as low as several hertz; it also uses a hydrophobic coating to provide a broad frequency bandwidth. As liquid slops in accordance with external motions, proposed energy harvester shows large capacitance variations. The device was tested under various conditions with periodic and nonperiodic movements. The maximum capacitance obtained from the fabricated device was about 10 nF, whereas the minimum capacitance was 5 pF, resulting in an extremely high capacitance ratio of 2000. The hydrophobic treatment enables the fabricated device to work well for periodic motions with a frequency range of 2-5 Hz. The power generated from a human running motion at a speed of 8 km h-1 is theoretically estimated to be 35.3 µW with charge-constrained conversion and an auxiliary voltage of 1 V.

  1. An ionic liquid-in-water microemulsion as a potential carrier for topical delivery of poorly water soluble drug: Development, ex-vivo and in-vivo evaluation.

    PubMed

    Goindi, Shishu; Kaur, Ramanpreet; Kaur, Randeep

    2015-11-30

    In this paper, we report an ionic liquid-in-water (IL/w) microemulsion (ME) formulation which is able to solubilize etodolac (ETO), a poorly water soluble drug for topical delivery using BMIMPF6 (1-butyl-3-methylimidazolium hexafluorophosphate) as IL, Tween 80 as surfactant and ethanol as co-surfactant. The prepared ME was characterized for physicochemical parameters, subjected to ex-vivo permeation studies as well as in-vivo pharmacodynamic evaluation. The ex-vivo drug permeation studies through rat skin was performed using Franz-diffusion cell and the IL/w based ME showed maximum mean cumulative percent permeation of 99.030±0.921% in comparison to oil-in-water (o/w) ME (61.548±1.875%) and oily solution (48.830±2.488%) of ETO. In-vivo anti-arthritic and anti-inflammatory activities of the prepared formulations were evaluated using different rodent models and the results revealed that ETO loaded IL/w based ME was found to be more effective in controlling inflammation than oily solution, o/w ME and marketed formulation of ETO. Histopathological studies also demonstrated that IL/w based ME caused no anatomical and pathological changes in the skin. PMID:26456294

  2. Measurements of Solid-Liquid Interfacial Energies in the Organic Monotectic Alloys

    NASA Astrophysics Data System (ADS)

    Böyük, U.; Yüceer, K.; Keşlioğlu, K.; Ulgen, A.; Maraşli, N.

    The commercial purity dibromobenzene (DBB) and succinonitrile (SCN) were purified using a columnar distillation system. Thin walled rectangular specimen cells (60-80 μm thick) were fabricated and filled with the purified materials under the vacuum. The specimen cell was placed in a horizontal temperature gradient stage. A thin liquid layer was melted and the specimen was annealed in a constant temperature gradient for an enough time to observe the equilibrated grain boundary groove shapes. The thermal conductivities of solid and liquid phases for the purified DBB and DBB-5.7 mol% SCN alloy were determined with the radial heat flow and the Bridgman-type growth apparatuses. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficients, solid-liquid interfacial energies, and the grain boundary energies for solid DBB in equilibrium with its melts and solid DBB in equilibrium with DBB-SCN monotectic liquid have been determined. The temperature coefficients of the purified DBB and DBB-5.7 mol% SCN alloy were also determined from thermal conductivity curve vs temperature.

  3. Measurement of solid-liquid interfacial energy in the pyrene succinonitrile monotectic system.

    PubMed

    Akbulut, S; Ocak, Y; Böyük, U; Erol, M; Keşlioğlu, K; Maraşli, N

    2006-09-20

    The equilibrated grain boundary groove shapes for solid pyrene (PY) in equilibrium with the PY succinonitrile (SCN) monotectic liquid were directly observed. From the observed grain boundary groove shapes, the Gibbs-Thomson coefficient and solid-liquid interfacial energy for solid PY in equilibrium with the PY SCN monotectic liquid have been determined to be (8.72 ± 0.87) × 10(-8) K m and (21.9 ± 3.28) × 10(-3) J m(-2) with the present numerical method and Gibbs-Thomson equation, respectively. The grain boundary energy of the solid PY phase has been determined to be (42.84 ± 7.28) × 10(-3) J m(-2) from the observed grain boundary groove shapes. Thermal conductivities of solid and liquid phases for PY-2.5 mol% SCN alloy and pure PY have also been measured. PMID:21690896

  4. Investigating the influence of production conditions on the energy distribution between the solid, liquid and gaseous products of slow pyrolysis

    NASA Astrophysics Data System (ADS)

    Crombie, Kyle; Masek, Ondrej

    2013-04-01

    Slow pyrolysis is a well established technology for converting biomass into a more stable form of carbon (biochar) while also producing energy rich by-products of bio-oil and syngas. Biochar is the porous, carbonaceous material produced by thermo-chemical treatment of organic materials in an oxygen-limited environment. Biochar can be incorporated into soils to improve soil fertility, reduce greenhouse gas emissions as well as provide long term storage of carbon or alternatively it can also provide additional energy to a pyrolysis system through combustion. Biochar production conditions have a significant influence on the yield as well as physiochemical and functional properties of the final pyrolysis products, resulting in a selection process aimed towards either agricultural benefits and carbon mitigation or heat/energy generation. This work aimed to investigate the effect of temperature, residence time and gas flow rate on the product energy distribution as well as the physical, chemical and soil functional properties of biochar, in order to optimise conditions best suited to maximise both energy value and agronomic benefit. Biochar samples were produced from wood pellets (WP) and straw pellets (SP) at two temperatures (350 and 650oC), with three residence times (10, 20 and 40 minutes) and three carrier gas flow rates (0, 0.3 and 0.6 L min-1). The energy balance of the system was determined through the calorimetric analysis of biochar and bio-oil, while the higher heating value for the syngas was calculated from the gas composition measured via mass spectroscopy. Biochar was also analysed for the physiochemical properties of proximate analysis and ultimate analysis as well as the functional property of environmentally stable carbon (C) content. As expected the yield of biochar decreased with increasing temperature resulting in elevated yields of liquid and gas fractions. Increased temperature also resulted in higher values of fixed C, total C, stable C and

  5. Attosecond pulse carrier-envelope phase effects on ionized electron momentum and energy distributions: roles of frequency, intensity and an additional IR pulse

    NASA Astrophysics Data System (ADS)

    Peng, Liang-You; Pronin, Evgeny A.; Starace, Anthony F.

    2008-02-01

    The effects of the carrier-envelope phase (CEP) of a few-cycle attosecond pulse on ionized electron momentum and energy spectra are analyzed, both with and without an additional few-cycle IR pulse. In the absence of an IR pulse, the CEP-induced asymmetries in the ionized electron momentum distributions are shown to vary as the 3/2 power of the attosecond pulse intensity. These asymmetries are also found to satisfy an approximate scaling law involving the frequency and intensity of the attosecond pulse. In the presence of even a very weak IR pulse (having an intensity of the order of 1011 1012 W cm-2), the attosecond pulse CEP-induced asymmetries in the ionized electron momentum distributions are found to be significantly augmented. In addition, for higher IR laser intensities, we observe for low electron energies peaks separated by the IR photon energy in one electron momentum direction along the laser polarization axis; in the opposite direction, we find structured peaks that are spaced by twice the IR photon energy. Possible physical mechanisms for such asymmetric, low-energy structures in the ionized electron momentum distribution are proposed. Our results are based on single-active-electron solutions of the three-dimensional, time-dependent Schrödinger equation including atomic potentials appropriate for the H and He atoms.

  6. Experimental and numerical investigations of the impingement of an oblique liquid jet onto a superhydrophobic surface: energy transformation

    NASA Astrophysics Data System (ADS)

    Kibar, Ali

    2016-02-01

    This study presents the theory of impinging an oblique liquid jet onto a vertical superhydrophobic surface based on both experimental and numerical results. A Brassica oleracea leaf with a 160° apparent contact angle was used for the superhydrophobic surface. Distilled water was sent onto the vertical superhydrophobic surface in the range of 1750-3050 Reynolds number, with an inclination angle of 20°-40°, using a circular glass tube with a 1.75 mm inner diameter. The impinging liquid jet spread onto the surface governed by the inertia of the liquid and then reflected off the superhydrophobic surface due to the surface energy of the spreading liquid. Two different energy approaches, which have time-scale and per-unit length, were performed to determine transformation of the energy. The kinetic energy of the impinging liquid jet was transformed into the surface energy with an increasing interfacial surface area between the liquid and air during spreading. Afterwards, this surface energy of the spreading liquid was transformed into the reflection kinetic energy.

  7. 15 K liquid hydrogen thermal Energy Storage Unit for future ESA science missions

    NASA Astrophysics Data System (ADS)

    Borges de Sousa, P.; Martins, D.; Tomás, G.; Barreto, J.; Noite, J.; Linder, M.; Fruchart, D.; de Rango, P.; Haettel, R.; Catarino, I.; Bonfait, G.

    2015-12-01

    A thermal Energy Storage Unit (ESU) using liquid hydrogen has been developed as a solution for absorbing the heat peaks released by the recycling phase of a 300 mK cooler that is a part of the cryogenic chain of one of ESA's new satellites for science missions. This device is capable of storing 400 J of thermal energy between 15 and 16 K by taking advantage of the liquid-to-vapor latent heat of hydrogen in a closed system. This paper describes some results obtained with the development model of the ESU under different configurations and using two types of hydrogen storage: a large expansion volume for ground testing and a much more compact unit, suitable for space applications and that can comply with ESA's mass budget.

  8. Pressure-energy correlations and thermodynamic scaling in viscous Lennard-Jones liquids

    NASA Astrophysics Data System (ADS)

    Coslovich, D.; Roland, C. M.

    2009-01-01

    We use molecular dynamics simulation results on viscous binary Lennard-Jones mixtures to examine the correlation between the potential energy and the virial. In accord with a recent proposal [U. R. Pedersen et al., Phys. Rev. Lett. 100, 015701 (2008)], the fluctuations in the two quantities are found to be strongly correlated, exhibiting a proportionality constant, Γ, numerically equal to one-third the slope of an inverse power law approximation to the intermolecular potential function. The correlation is stronger at higher densities, where interatomic separations are in the range where the inverse power law approximation is more accurate. These same liquids conform to thermodynamic scaling of their dynamics, with the scaling exponent equal to Γ. Thus, the properties of strong correlation between energy and pressure and thermodynamic scaling both reflect the ability of an inverse power law representation of the potential to capture interesting features of the dynamics of dense, highly viscous liquids.

  9. Generation of Equal-Energy Orbital Angular Momentum Beams via Photopatterned Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Chen, Peng; Ge, Shi-Jun; Ma, Ling-Ling; Hu, Wei; Chigrinov, Vladimir; Lu, Yan-Qing

    2016-04-01

    Orbital angular momentum (OAM) has been extensively studied to date and has become topical in the last few years due to its potential for increasing bandwidth in optical communications. The so-called Dammann vortex grating (DVG) can generate a series of equal-energy OAM beams and satisfactorily realize OAM parallel detection, an important challenge in this field. However, previously reported DVGs suffer from polarization sensitivity, low efficiency, or the lack of tunability and mode variety. Here, a design of liquid-crystal DVGs is proposed and demonstrated for the generation of various equal-energy OAM beams. The DVGs, featured by alternative orthogonally planar-aligned regions, are carried out via photopatterning technology. Beam arrays composed of arbitrary OAM modes, as well as two-dimensional ones, are generated in good quality and high efficiency. The liquid-crystal DVGs exhibit merits of excellent polarization independency, electrical switchability, and tunability. This supplies a promising approach towards OAM generation, manipulation, and detection.

  10. Assessment of energy balance against the nutritional status of women carriers in the brickfields of West Bengal.

    PubMed

    Bandyopadhyay, Bijetri; Sen, Devashish

    2016-09-01

    The Indian brick industry is an unorganized sector in which large numbers of migrant women workers are employed. A survey was conducted on 62 women workers working in different brickfields of West Bengal to assess their physiological workload, nutritional profile, total energy expenditure and energy balance. Energy intake was calculated using physiological fuel values of carbohydrate, fat and protein. From the results it is seen that 13% of the sample population falls under severe (grade III) chronic energy deficiency. The average daily consumption of the workers was comparatively lower than their daily energy expenditure, considering the nature of the job which falls under heavy to extremely heavy categories. This negative energy balance is effectively observed in the nutritional anthropometry data. Thus, an immediate ergonomics intervention with better nutrition should be implemented to improve the health status of the workers so they can safely continue to work for a longer period. PMID:27092582

  11. Effect of the energy density of a solid-liquid meal on gastric emptying and satiety.

    PubMed

    Carbonnel, F; Lémann, M; Rambaud, J C; Mundler, O; Jian, R

    1994-09-01

    The effect of the energy density of a meal on gastric emptying and satiety was assessed in nine volunteers. They ingested, in randomized order, a diluted (2671 kJ/L, 950 mL) and a concentrated (7452 kJ/L, 350 mL) test meal of 2500 kJ each (80% as solids). Half-emptying times of solids and liquids were not significantly different for the diluted and concentrated meal (solids: 145 +/- 18 and 156 +/- 16 min, respectively; liquids: 76 +/- 10 and 84 +/- 10 min, respectively), and consequently, pyloric outputs of energy were identical. Neither the intensity and duration of satiety, nor the amount of energy ingested, ad libitum, 6 h after the test meal, were significantly affected by energy density of the food ingested. Both the intensity and duration of satiety correlated significantly with the gastric emptying time for solids (r = 0.60 and 0.67, respectively, P < 0.01). These results show that satiety depends on gastric emptying of energy and is not affected by the energy density of food intake. PMID:8074058

  12. Lithium-antimony-lead liquid metal battery for grid-level energy storage

    NASA Astrophysics Data System (ADS)

    Wang, Kangli; Jiang, Kai; Chung, Brice; Ouchi, Takanari; Burke, Paul J.; Boysen, Dane A.; Bradwell, David J.; Kim, Hojong; Muecke, Ulrich; Sadoway, Donald R.

    2014-10-01

    The ability to store energy on the electric grid would greatly improve its efficiency and reliability while enabling the integration of intermittent renewable energy technologies (such as wind and solar) into baseload supply. Batteries have long been considered strong candidate solutions owing to their small spatial footprint, mechanical simplicity and flexibility in siting. However, the barrier to widespread adoption of batteries is their high cost. Here we describe a lithium-antimony-lead liquid metal battery that potentially meets the performance specifications for stationary energy storage applications. This Li||Sb-Pb battery comprises a liquid lithium negative electrode, a molten salt electrolyte, and a liquid antimony-lead alloy positive electrode, which self-segregate by density into three distinct layers owing to the immiscibility of the contiguous salt and metal phases. The all-liquid construction confers the advantages of higher current density, longer cycle life and simpler manufacturing of large-scale storage systems (because no membranes or separators are involved) relative to those of conventional batteries. At charge-discharge current densities of 275 milliamperes per square centimetre, the cells cycled at 450 degrees Celsius with 98 per cent Coulombic efficiency and 73 per cent round-trip energy efficiency. To provide evidence of their high power capability, the cells were discharged and charged at current densities as high as 1,000 milliamperes per square centimetre. Measured capacity loss after operation for 1,800 hours (more than 450 charge-discharge cycles at 100 per cent depth of discharge) projects retention of over 85 per cent of initial capacity after ten years of daily cycling. Our results demonstrate that alloying a high-melting-point, high-voltage metal (antimony) with a low-melting-point, low-cost metal (lead) advantageously decreases the operating temperature while maintaining a high cell voltage. Apart from the fact that this finding

  13. Ultrafast carriers dynamics in filled-skutterudites

    SciTech Connect

    Guo, Liang; Xu, Xianfan; Salvador, James R.

    2015-06-08

    Carrier dynamics of filled-skutterudites, an important class of thermoelectric materials, is investigated using ultrafast optical spectroscopy. By tuning the wavelength of the probe laser, charge transfers at different electronic energy levels are interrogated. Analysis based on the Kramers-Kronig relation explains the complex spectroscopy data, which is mainly due to band filling caused by photo-excited carriers and free carrier absorption. The relaxation time of hot carriers is found to be about 0.4–0.6 ps, depending on the electronic energy level, and the characteristic time for carrier-phonon equilibrium is about 0.95 ps. These studies of carrier dynamics, which fundamentally determines the transport properties of thermoelectric material, can provide guidance for the design of materials.

  14. Effect of static pressure on acoustic energy radiated by cavitation bubbles in viscous liquids under ultrasound.

    PubMed

    Yasui, Kyuichi; Towata, Atsuya; Tuziuti, Toru; Kozuka, Teruyuki; Kato, Kazumi

    2011-11-01

    The effect of static pressure on acoustic emissions including shock-wave emissions from cavitation bubbles in viscous liquids under ultrasound has been studied by numerical simulations in order to investigate the effect of static pressure on dispersion of nano-particles in liquids by ultrasound. The results of the numerical simulations for bubbles of 5 μm in equilibrium radius at 20 kHz have indicated that the optimal static pressure which maximizes the energy of acoustic waves radiated by a bubble per acoustic cycle increases as the acoustic pressure amplitude increases or the viscosity of the solution decreases. It qualitatively agrees with the experimental results by Sauter et al. [Ultrason. Sonochem. 15, 517 (2008)]. In liquids with relatively high viscosity (∼200 mPa s), a bubble collapses more violently than in pure water when the acoustic pressure amplitude is relatively large (∼20 bar). In a mixture of bubbles of different equilibrium radius (3 and 5 μm), the acoustic energy radiated by a 5 μm bubble is much larger than that by a 3 μm bubble due to the interaction with bubbles of different equilibrium radius. The acoustic energy radiated by a 5 μm bubble is substantially increased by the interaction with 3 μm bubbles. PMID:22087995

  15. Direct measurement of the exciton binding energy and effective masses for charge carriers in organic-inorganic tri-halide perovskites

    NASA Astrophysics Data System (ADS)

    Miyata, Atsuhiko; Mitioglu, Anatolie; Plochocka, Paulina; Portugall, Oliver; Wang, Jacob Tse-Wei; Stranks, Samuel D.; Snaith, Henry J.; Nicholas, Robin J.

    2015-07-01

    Solar cells based on the organic-inorganic tri-halide perovskite family of materials have shown significant progress recently, offering the prospect of low-cost solar energy from devices that are very simple to process. Fundamental to understanding the operation of these devices is the exciton binding energy, which has proved both difficult to measure directly and controversial. We demonstrate that by using very high magnetic fields it is possible to make an accurate and direct spectroscopic measurement of the exciton binding energy, which we find to be only 16 meV at low temperatures, over three times smaller than has been previously assumed. In the room-temperature phase we show that the binding energy falls to even smaller values of only a few millielectronvolts, which explains their excellent device performance as being due to spontaneous free-carrier generation following light absorption. Additionally, we determine the excitonic reduced effective mass to be 0.104me (where me is the electron mass), significantly smaller than previously estimated experimentally but in good agreement with recent calculations. Our work provides crucial information about the photophysics of these materials, which will in turn allow improved optoelectronic device operation and better understanding of their electronic properties.

  16. High energy gas fracture experiments in liquid-filled boreholes: potential geothermal application

    SciTech Connect

    Cuderman, J.F.; Chu, T.Y.; Jung, J.; Jacobson, R.D.

    1986-07-01

    High Energy Gas Fracturing is a tailored pulse fracturing technique which uses propellants to obtain controlled fracture initiation and extension. Borehole pressurization rates can be tailored, by suitable choice of propellants, to produce four or eight fractures radiating from the wellbore. High Energy Gas Fracture (HEGF) research is conducted at DOE's Nevada Test Site (NTS) in a tunnel complex where experiments can be done under realistic in situ stress conditions (1400 psi (9.7 MPa) overburden stress). Pressure measurements are made in the test borehole during all fracturing experiments. Experiments are mined back to provide direct observation of fracturing obtained. The initial objective of HEGF research was to develop multiple fracturing technology for application in gas well stimulation. HEGF research at NTS and in Devonian shale demonstration tests has resulted in a completed technology for multiple fracturing in uncased, liquid-free wellbores. Current resarch is directed toward extending the technique to liquid-filled boreholes for application in geothermal in addition to gas and oil wells. For liquid-free boreholes, multiple fracturing is specified in terms of pressure risetime required for a given borehole diameter. Propellants are mixed to achieve the desired risetime using a semiempirical mixing equation. The same techniques were successfully applied to fracturing in liquid-filled wellbores. However, the addition of liquid in the borehole results in a significantly more complicated fracturing behavior. Hydrodynamic effects are significant. Multiple fractures are initiated but only some propagated. Multiple- and hydraulic-type fracturing and wellbore crushing have been observed in the same experiment. The potential of using HEGB for geothermal well stimulation has been demonstrated through the present experiments. 18 refs., 40 figs., 4 tabs.

  17. Fluorescence energy transfer efficiency in labeled yeast cytochrome c: a rapid screen for ion biocompatibility in aqueous ionic liquids

    SciTech Connect

    Baker, Sheila N; Zhao, Hua; Pandey, Siddharth; Heller, William T; Bright, Frank; Baker, Gary A

    2011-01-01

    A fluorescence energy transfer de-quenching assay was implemented to follow the equilibrium unfolding behaviour of site-specific tetramethylrhodamine-labelled yeast cytochrome c in aqueous ionic liquid solutions; additionally, this approach offers the prospect of naked eye screening for biocompatible ion combinations in hydrated ionic liquids.

  18. Role of the low-energy excited states in the radiolysis of aromatic liquids.

    PubMed

    Baidak, Aliaksandr; Badali, Matthew; LaVerne, Jay A

    2011-07-01

    The contribution of the low-energy excited states to the overall product formation in the radiolysis of simple aromatic liquids--benzene, pyridine, toluene, and aniline--has been examined by comparison of product yields obtained in UV-photolysis and in γ-radiolysis. In photolysis, these electronic excited states were selectively populated using UV-light excitation sources with various energies. Yields of molecular hydrogen and of "dimers" (biphenyl, bibenzyl, dipyridyl for benzene, toluene, pyridine, respectively, and of ammonia and diphenylamine for aniline) have been determined, since they are the most abundant radiolytic products. Negligibly small production of molecular hydrogen in the UV-photolysis of aromatic liquids with excitation to energies of 4.88, 5.41, 5.79, and 6.70 eV and the lack of a scavenger effect suggest that this product originates from short-lived high-energy singlet states. A significant reduction in "dimer" radiation-chemical yields in the presence of scavengers such as anthracene or naphthalene indicates that the triplet excited states are important precursors to these products. The results for toluene and aniline suggest that efficient dissociation from the lowest-energy excited triplet state leads to noticeable "dimer" production. For benzene and pyridine, the lowest-energy triplet excited states are not likely to fragment into radicals because of the relatively large energy gap between the excited state level and corresponding bond dissociation energy. The "dimer" formation in the radiolysis of benzene and pyridine is likely to involve short-lived high-energy triplet states. PMID:21634362

  19. A comparative analysis of well-to-wheel primary energy demand and greenhouse gas emissions for the operation of alternative and conventional vehicles in Switzerland, considering various energy carrier production pathways

    NASA Astrophysics Data System (ADS)

    Yazdanie, Mashael; Noembrini, Fabrizio; Dossetto, Lionel; Boulouchos, Konstantinos

    2014-03-01

    This study provides a comprehensive analysis of well-to-wheel (WTW) primary energy demand and greenhouse gas (GHG) emissions for the operation of conventional and alternative passenger vehicle drivetrains. Results are determined based on a reference vehicle, drivetrain/production process efficiencies, and lifecycle inventory data specific to Switzerland. WTW performance is compared to a gasoline internal combustion engine vehicle (ICEV). Both industrialized and novel hydrogen and electricity production pathways are evaluated. A strong case is presented for pluggable electric vehicles (PEVs) due to their high drivetrain efficiency. However, WTW performance strongly depends on the electricity source. A critical electricity mix can be identified which divides optimal drivetrain performance between the EV, ICEV, and plug-in hybrid vehicle. Alternative drivetrain and energy carrier production pathways are also compared by natural resource. Fuel cell vehicle (FCV) performance proves to be on par with PEVs for energy carrier (EC) production via biomass and natural gas resources. However, PEVs outperform FCVs via solar energy EC production pathways. ICE drivetrains using alternative fuels, particularly biogas and CNG, yield remarkable WTW energy and emission reductions as well, indicating that alternative fuels, and not only alternative drivetrains, play an important role in the transition towards low-emission vehicles in Switzerland.

  20. Charge and energy transferred from a plasma jet to liquid and dielectric surfaces

    NASA Astrophysics Data System (ADS)

    Mussard, M. Dang Van Sung; Foucher, E.; Rousseau, A.

    2015-10-01

    A key parameter in using plasma jets for biomedical applications is the transferred energy to the living tissues. The objective of this paper is to understand which parameters control the energy transfer from the plasma jet to a liquid or a dielectric surface. The plasma jet is flown with helium and ignited by a 600 Hz ac high voltage (up to 15 kV). Capacitors are connected to two measurement electrodes placed in the plasma source region, and under the sample. Charge and energy transferred are estimated by plotting Lissajous cycles; the number of bullets and the charge probability density function are also calculated. It is shown that the applied voltage and the gap (distance between the end of the tube and the sample) have a dramatic influence on the energy deposition on the sample as well as on the charge probability density function. Surprisingly, both gap distance and voltage have very little influence on the number of bullets reaching the sample per cycle. It is also shown that the conductivity of the liquid sample has almost no influence on the energy deposition and charge probability density function.

  1. Part-load performance characterization and energy savings potential of the RTU challenge unit: Carrier weather expert

    SciTech Connect

    Wang, Weimin; Katipamula, Srinivas; Taasevigen, Danny J.

    2015-09-29

    This report documents the development of part-load performance curves and there use with the EnergyPlus simulation tool to estimate the potential savings from the use of WeatherExpert units compared to other standard options.

  2. Liquid scintillator for 2D dosimetry for high-energy photon beams

    SciTech Connect

    Poenisch, Falk; Archambault, Louis; Briere, Tina Marie; Sahoo, Narayan; Mohan, Radhe; Beddar, Sam; Gillin, Michael T.

    2009-05-15

    Complex radiation therapy techniques require dosimetric verification of treatment planning and delivery. The authors investigated a liquid scintillator (LS) system for application for real-time high-energy photon beam dosimetry. The system was comprised of a transparent acrylic tank filled with liquid scintillating material, an opaque outer tank, and a CCD camera. A series of images was acquired when the tank with liquid scintillator was irradiated with a 6 MV photon beam, and the light data measured with the CCD camera were filtered to correct for scattering of the optical light inside the liquid scintillator. Depth-dose and lateral profiles as well as two-dimensional (2D) dose distributions were found to agree with results from the treatment planning system. Further, the corrected light output was found to be linear with dose, dose rate independent, and is robust for single or multiple acquisitions. The short time needed for image acquisition and processing could make this system ideal for fast verification of the beam characteristics of the treatment machine. This new detector system shows a potential usefulness of the LS for 2D QA.

  3. Calcium-bismuth electrodes for large-scale energy storage (liquid metal batteries)

    SciTech Connect

    Kim, H; Boysen, DA; Ouchi, T; Sadoway, DR

    2013-11-01

    Calcium is an attractive electrode material for use in grid-scale electrochemical energy storage due to its low electronegativity, earth abundance, and low cost. The feasibility of combining a liquid Ca-Bi positive electrode with a molten salt electrolyte for use in liquid metal batteries at 500-700 degrees C was investigated. Exhibiting excellent reversibility up to current densities of 200 mA cm(-2), the calcium bismuth liquid alloy system is a promising positive electrode candidate for liquid metal batteries. The measurement of low self-discharge current suggests that the solubility of calcium metal in molten salt electrolytes can be sufficiently suppressed to yield high coulombic efficiencies >98%. The mechanisms giving rise to Ca-Bi electrode overpotentials were investigated in terms of associated charge transfer and mass transport resistances. The formation of low density Ca11Bi10 intermetallics at the electrode electrolyte interface limited the calcium deposition rate capability of the electrodes; however, the co-deposition of barium into bismuth from barium-containing molten salts suppressed Ca-Bi intermetallic formation thereby improving the discharge capacity. (C) 2013 Elsevier B.V. All rights reserved.

  4. Measurement of the Field-Dependent Response of Liquid Xenon to Low-Energy Electronic Recoils

    NASA Astrophysics Data System (ADS)

    Goetzke, Luke; Anthony, Matthew; Aprile, Elena; de Perio, Patrick; Greene, Zach; Lin, Qing; Messina, Marcello; Plante, Guillaume; Rizzo, Alfio; Zhang, Yun

    2016-03-01

    The search for the direct detection of dark matter continues to be led by experiments employing liquid xenon (LXe) as the detection medium. Still, few measurements have been made of the response of LXe to low-energy interactions as a function of energy and electric field. The neriX detector at Columbia University is a dual-phase time projection chamber optimized for simultaneous measurements of light and charge from low-energy interactions in LXe. In this talk, we will present the results of measurements of the light and charge yield of electronic recoils in LXe using neriX. The Compton coincidence technique is employed to extract the yields as a function of energy deposited at different electric fields. We gratefully acknowledge the continued support of the XENON Dark Matter program at Columbia University by the National Science Foundation.

  5. Cross-section scaling for track structure simulations of low-energy ions in liquid water.

    PubMed

    Schmitt, E; Friedland, W; Kundrát, P; Dingfelder, M; Ottolenghi, A

    2015-09-01

    Radiation damage by low-energy ions significantly contributes to the high biological efficiency of ion beams in distal Bragg peak regions as well as to the energy-dependent efficiency of neutron irradiation. To enable assessing biological effects of ions at energies <1 MeV u(-1) with track-structure based models, a Barkas-like scaling procedure is developed that provides ion cross sections in liquid water based on those for hydrogen ions. The resulting stopping power and range for carbon ions agree with the ICRU 73 database and other low-energy stopping power data. The method represents the basis for extending PARTRAC simulations of light ion track structures and biological effects down to the keV u(-1) range. PMID:25969528

  6. Quantification of ordering at a solid-liquid interface using plasmon electron energy loss spectroscopy

    SciTech Connect

    Gandman, Maria; Kauffmann, Yaron; Kaplan, Wayne D.

    2015-02-02

    We present an in situ electron energy loss spectroscopy (EELS) study of ordering of liquid Al at various Al-Al{sub 2}O{sub 3} interfaces. This technique utilizes precise measurements of the shifts in bulk plasmon resonance and their sensitivity to the valence electron density. Plasmon EELS combined with high resolution transmission electron microscopy provides information regarding the chemical composition in liquid Al at Al-Al{sub 2}O{sub 3} interfaces. Preferential oxygen segregation to the (0006) Al{sub 2}O{sub 3} plane was verified, and the (101{sup ¯}2) Al{sub 2}O{sub 3} plane was found to contain the lowest amount of segregated species.

  7. Study of Coherent Raman Energy Transfer in Molecular Liquids with Strong Field Laser Excitation

    NASA Astrophysics Data System (ADS)

    Pearson, B. J.; Morris, D. S.; Bucksbaum, P. H.; Weinacht, T. C.

    2001-05-01

    We investigate coherent population transfer among vibrational states in molecular liquids via stimulated Raman scattering. A learning algorithm and ultrafast optical pulse shaper are able to selectively excite or suppress excitation in adjacent vibrational modes. In particular, results with deuterated methanol (CD3OD) are compared to previous results in methanol (CH3OH) in order to test possible control mechanisms for the observed energy transfer. Analysis includes examination of both the optimal pulse shapes as well as the spectrum of the pulse intensity envelope. Although the interaction is non-impulsive, control is still achieved. Further investigations with other molecular liquids including ethanol should provide additional information. This work is supported by the National Science Foundation, grant 9987916.

  8. Anchoring energy enhancement and pretilt angle control of liquid crystal alignment on polymerized surfaces

    NASA Astrophysics Data System (ADS)

    Weng, Libo; Liao, Pei-Chun; Lin, Chen-Chun; Ting, Tien-Lun; Hsu, Wen-Hao; Su, Jenn-Jia; Chien, Liang-Chy

    2015-09-01

    We demonstrate enhanced surface anchoring energy and control of pretilt angle in a nematic liquid crystal cell with vertical alignment and polymerized surfaces (PS-VA). The polymerized surfaces are formed by ultraviolet (UV) irradiation-induced phase separation of a minute amount of a reactive monomer in the vertical-aligned nematic liquid crystal. By introducing a bias voltage during UV curing, surface-localized polymer protrusions with a dimension of 100nm and a field-induced pretilt angle are observed. Experimental evidences and theoretical analyses validate that PS-VA has increased surface anchoring strength by two folds and pretilt angle has been changed from 89° to 86° compared to those of a VA cell. The enabling PS-VA cell technique with excel electro-optical properties such as very good dark state, high optical contrast, and fast rise and decay times may lead to development of a wide range of applications.

  9. Intermediate pyrolysis of biomass energy pellets for producing sustainable liquid, gaseous and solid fuels.

    PubMed

    Yang, Y; Brammer, J G; Mahmood, A S N; Hornung, A

    2014-10-01

    This work describes the use of intermediate pyrolysis system to produce liquid, gaseous and solid fuels from pelletised wood and barley straw feedstock. Experiments were conducted in a pilot-scale system and all products were collected and analysed. The liquid products were separated into an aqueous phase and an organic phase (pyrolysis oil) under gravity. The oil yields were 34.1 wt.% and 12.0 wt.% for wood and barley straw, respectively. Analysis found that both oils were rich in heterocyclic and phenolic compounds and have heating values over 24 MJ/kg. The yields of char for both feedstocks were found to be about 30 wt.%, with heating values similar to that of typical sub-bituminous class coal. Gas yields were calculated to be approximately 20 wt.%. Studies showed that both gases had heating values similar to that of downdraft gasification producer gas. Analysis on product energy yields indicated the process efficiency was about 75%. PMID:25088312

  10. Low-Energy Spin Dynamics of the Honeycomb Spin Liquid Beyond the Kitaev Limit

    NASA Astrophysics Data System (ADS)

    Song, Xue-Yang; You, Yi-Zhuang; Balents, Leon

    2016-07-01

    We investigate the generic features of the low energy dynamical spin structure factor of the Kitaev honeycomb quantum spin liquid perturbed away from its exact soluble limit by generic symmetry-allowed exchange couplings. We find that the spin gap persists in the Kitaev-Heisenberg model, but generally vanishes provided more generic symmetry-allowed interactions exist. We formulate the generic expansion of the spin operator in terms of fractionalized Majorana fermion operators according to the symmetry enriched topological order of the Kitaev spin liquid, described by its projective symmetry group. The dynamical spin structure factor displays power-law scaling bounded by Dirac cones in the vicinity of the Γ , K , and K' points of the Brillouin zone, rather than the spin gap found for the exactly soluble point.

  11. Anchoring energy enhancement and pretilt angle control of liquid crystal alignment on polymerized surfaces

    SciTech Connect

    Weng, Libo; Chien, Liang-Chy; Liao, Pei-Chun; Lin, Chen-Chun; Ting, Tien-Lun; Hsu, Wen-Hao; Su, Jenn-Jia

    2015-09-15

    We demonstrate enhanced surface anchoring energy and control of pretilt angle in a nematic liquid crystal cell with vertical alignment and polymerized surfaces (PS-VA). The polymerized surfaces are formed by ultraviolet (UV) irradiation-induced phase separation of a minute amount of a reactive monomer in the vertical-aligned nematic liquid crystal. By introducing a bias voltage during UV curing, surface-localized polymer protrusions with a dimension of 100nm and a field-induced pretilt angle are observed. Experimental evidences and theoretical analyses validate that PS-VA has increased surface anchoring strength by two folds and pretilt angle has been changed from 89° to 86° compared to those of a VA cell. The enabling PS-VA cell technique with excel electro-optical properties such as very good dark state, high optical contrast, and fast rise and decay times may lead to development of a wide range of applications.

  12. Compressed Liquid Densities and Helmholtz Energy Equation of State for Fluoroethane (R161)

    NASA Astrophysics Data System (ADS)

    Qi, Haiyan; Fang, Dan; Gao, Kehui; Meng, Xianyang; Wu, Jiangtao

    2016-06-01

    In this study, compressed liquid densities of Fluoroethane (R161, CAS No. 353-36-6) were measured using a high-pressure vibrating-tube densimeter over the temperature range from (283 to 363) K with pressures up to 100 MPa. A Helmholtz energy equation of state for R161 was developed from these density measurements and other experimental thermodynamic property data from the literature. The formulation is valid for temperatures from the triple point temperature of 130 K to 420 K with pressures up to 100 MPa. The approximate uncertainties of properties calculated with the new equation of state are estimated to be 0.25 % in density, 0.2 % in saturated liquid density between 230 K and 320 K, and 0.2 % in vapor pressure below 350 K. Deviations in the critical region are higher for all properties. The extrapolation behavior of the new formulation at high temperatures and high pressures is reasonable.

  13. Capacitive Energy Storage from - 50o to 100o Using an Ionic Liquid Electrolyte

    SciTech Connect

    Lin, Rongying; Taberna, Pierre-Louis; Santini, Sebastien; Presser, Volker; Perez, Carlos R.; Malbosc, Francois; Rupesinghe, Nalin L.; Teo, Kenneth B. K.; Gogotsi, Yury G.; Simon, Patrice

    2011-01-01

    Relying on redox reactions, most batteries are limited in their ability to operate at very low or very high temperatures. While performance of electrochemical capacitors is less dependent on the temperature, present-day devices still cannot cover the entire range needed for automotive and electronics applications under a variety of environmental conditions. We show that the right combination of the exohedral nanostructured carbon (nanotubes and onions) electrode and a eutectic mixture of ionic liquids can dramatically extend the temperature range of electrical energy storage, thus defying the conventional wisdom that ionic liquids can only be used as electrolytes above room temperature. We demonstrate electrical double layer capacitors able to operate from 50 to 100 C over a wide voltage window (up to 3.7 V) and at very high charge/discharge rates of up to 20 V/s.

  14. A "First Principles" Potential Energy Surface for Liquid Water from VRT Spectroscopy of Water Clusters

    SciTech Connect

    Goldman, N; Leforestier, C; Saykally, R J

    2004-05-25

    We present results of gas phase cluster and liquid water simulations from the recently determined VRT(ASP-W)III water dimer potential energy surface. VRT(ASP-W)III is shown to not only be a model of high ''spectroscopic'' accuracy for the water dimer, but also makes accurate predictions of vibrational ground-state properties for clusters up through the hexamer. Results of ambient liquid water simulations from VRT(ASP-W)III are compared to those from ab initio Molecular Dynamics, other potentials of ''spectroscopic'' accuracy, and to experiment. The results herein represent the first time that a ''spectroscopic'' potential surface is able to correctly model condensed phase properties of water.

  15. Wetting transition in liquid Ga Bi alloys: light scattering study of surface energy and entropy

    NASA Astrophysics Data System (ADS)

    Ayyad, A. H.; Freyland, W.

    2002-05-01

    We have studied the surface energy, surface entropy and, partly, have received an estimate of the viscosity of liquid Ga-Bi alloys at compositions mainly in the Ga-rich phase region and at temperatures up to 620 K. Measurements have been performed by the noninvasive method of capillary wave spectroscopy which has been applied for the first time to investigate the surface properties of a liquid alloy at high temperatures. Analysis of the concentration dependence of the surface energy according to the Gibbs adsorption equation yields that in the composition range of 10 -2≲ xBi≲10 -1 and at temperatures of 450 K≲ T≲500 K a surface excess of ΓBi˜1.36×10 -5 mol m -2 resides at the liquid-vapour interface corresponding to pure Bi. At lower xBi a reduction of ΓBi occurs which is indicative of a prewetting transition. The variations of surface energy and entropy with composition are not consistent with a description by a simple monolayer model as was deduced from X-ray reflectivity results. Instead it is found that a multilayer model qualitatively accounts for the characteristic change of the surface quantities. The thickness of the multilayer interfacial region is estimated from the change of the relative surface entropy. This yields values between 10 and 20 Å with a trend for an increasing number of surface layers towards the complete wetting transition at the monotectic point. All isopleths of the surface energy exhibit clear kinks at temperatures 10-20 K above the liquidus curve for compositions below the monotectic point. The corresponding discontinuity of the surface entropy is consistent with a first order transition of surface freezing reported recently for the Ga-Bi system.

  16. Mathematical methods for restricted domain ternary liquid mixture free energy determination using light scattering

    NASA Astrophysics Data System (ADS)

    Wahle, Chris W.; Ross, David S.; Thurston, George M.

    2013-09-01

    We extend methods of solution of a light scattering partial differential equation for the free energy of mixing to apply to connected, isotropic ternary liquid composition domains that do not touch all three binary axes. To do so we mathematically analyze the problem of inferring needed Dirichlet boundary data, and solving for the free energy, with use of hypothetical static light scattering measurements that correspond to dielectric composition gradient vectors that have distinct directions. The physical idea behind the technique is that contrasting absorption properties of mixture components can result in such distinctly directed dielectric composition gradient vectors, due to their differing wavelength dependences of dielectric response. At suitably chosen wavelengths, contrasting light scattering efficiency patterns in the ternary composition triangle can then correspond to the same underlying free energy, and enlarge the scope of available information about the free energy, as shown here. We show how to use distinctly directed dielectric gradients to measure the free energy on both straight lines and curves within the ternary composition triangle, so as to provide needed Dirichlet conditions for light scattering partial differential equation solution. With use of Monte Carlo simulations of noisy light scattering data, we provide estimates of the overall system measurement time and sample spacing needed to determine the free energy to a desired degree of accuracy, for various angles between the assumed dielectric gradient vectors, and indicate how the measurement time depends on instrumental throughput parameters. The present analysis methods provide a way to use static light scattering to measure, directly, mixing free energies of many systems that contain such restricted liquid domains, including aqueous solutions of biological macromolecules, micellar mixtures and microemulsions, and many small molecule systems that are important in separation technology.

  17. Electron ionization cross-section calculations for liquid water at high impact energies

    NASA Astrophysics Data System (ADS)

    Bousis, C.; Emfietzoglou, D.; Hadjidoukas, P.; Nikjoo, H.; Pathak, A.

    2008-04-01

    Cross-sections for the ionization of liquid water is perhaps the most essential set of data needed for modeling electron transport in biological matter. The complexity of ab initio calculations for any multi-electron target has led to largely heuristic semi-empirical models which take advantage elements of the Bethe, dielectric and binary collision theories. In this work we present various theoretical models for calculating total ionization cross-sections (TICSs) for liquid water over the 10 keV-1 MeV electron energy range. In particular, we extend our recent dielectric model calculations for liquid water to relativistic energies using both the appropriate kinematic corrections and the transverse part. Comparisons are made with widely used atomic and molecular TICS models such as those of Khare and co-workers, Kim-Rudd, Deutsch-Märk, Vriens and Gryzinski. The required dipole oscillator strength was provided by our recent optical-data model which is based on the latest experimental data for liquid water. The TICSs computed by the above models differ by up to 40% from the dielectric results. The best agreement (to within ∼10%) was obtained by Khare's original model and an approximate form of Gryzinski's model. In contrast, the binary-encounter-dipole (BED) models of both Kim-Rudd and Khare and co-workers resulted in ∼10-20% higher TICS values, while discrepancies increased to ∼30-40% when their simpler binary-encounter-Bethe (BEB) versions were used. Finally, we discuss to what extent the accuracy of the TICS is indicative of the reliability of the underlying differential cross-sections.

  18. Carriers of the astronomical 2175 ? extinction feature

    SciTech Connect

    Bradley, J; Dai, Z; Ernie, R; Browning, N; Graham, G; Weber, P; Smith, J; Hutcheon, I; Ishii, H; Bajt, S; Floss, C; Stadermann, F

    2004-07-20

    The 2175 {angstrom} extinction feature is by far the strongest spectral signature of interstellar dust observed by astronomers. Forty years after its discovery the origin of the feature and the nature of the carrier remain controversial. The feature is enigmatic because although its central wavelength is almost invariant its bandwidth varies strongly from one sightline to another, suggesting multiple carriers or a single carrier with variable properties. Using a monochromated transmission electron microscope and valence electron energy-loss spectroscopy we have detected a 5.7 eV (2175 {angstrom}) feature in submicrometer-sized interstellar grains within interplanetary dust particles (IDPs) collected in the stratosphere. The carriers are organic carbon and amorphous silicates that are abundant and closely associated with one another both in IDPs and in the interstellar medium. Multiple carriers rather than a single carrier may explain the invariant central wavelength and variable bandwidth of the astronomical 2175 {angstrom} feature.

  19. Study on Introduction of CO2 Free Energy to Japan with Liquid Hydrogen

    NASA Astrophysics Data System (ADS)

    Kamiya, Shoji; Nishimura, Motohiko; Harada, Eichi

    In Japan, both CO2(Carbon dioxide) emission reduction and energy security are the very important social issues after Fukushima Daiichi accident. On the other hand, FCV (Fuel Cell Vehicle)using hydrogen will be on the market in 2015. Introducing large mass hydrogen energy is being expected as expanding hydrogen applications, or solution to energy issues of Japan.And then,the Japanese government announced the road map for introducing hydrogen energy supply chain in this June,2014. Under these circumstances, imported CO2 free hydrogen will be one of the solutions for energy security and CO2 reduction, if the hydrogen price is affordable. To achieve this, Kawasaki Heavy Industries, Ltd. (KHI) performed a feasibility studyon CO2-free hydrogen energy supply chainfrom Australian brown coal linked with CCS (Carbon dioxide Capture and Storage) to Japan. In the study, hydrogen production systems utilizing brown coal gasificationandLH2 (liquid hydrogen)systems as storing and transporting hydrogen are examined.This paper shows the possibilityof realizingthe CO2 free hydrogen supply chain, the cost breakdown of imported hydrogen cost, its cost competitiveness with conventionalfossil, andLH2systems as key technologies of the hydrogen energy chain.

  20. Estimation of energy density of Li-S batteries with liquid and solid electrolytes

    NASA Astrophysics Data System (ADS)

    Li, Chunmei; Zhang, Heng; Otaegui, Laida; Singh, Gurpreet; Armand, Michel; Rodriguez-Martinez, Lide M.

    2016-09-01

    With the exponential growth of technology in mobile devices and the rapid expansion of electric vehicles into the market, it appears that the energy density of the state-of-the-art Li-ion batteries (LIBs) cannot satisfy the practical requirements. Sulfur has been one of the best cathode material choices due to its high charge storage (1675 mAh g-1), natural abundance and easy accessibility. In this paper, calculations are performed for different cell design parameters such as the active material loading, the amount/thickness of electrolyte, the sulfur utilization, etc. to predict the energy density of Li-S cells based on liquid, polymeric and ceramic electrolytes. It demonstrates that Li-S battery is most likely to be competitive in gravimetric energy density, but not volumetric energy density, with current technology, when comparing with LIBs. Furthermore, the cells with polymer and thin ceramic electrolytes show promising potential in terms of high gravimetric energy density, especially the cells with the polymer electrolyte. This estimation study of Li-S energy density can be used as a good guidance for controlling the key design parameters in order to get desirable energy density at cell-level.

  1. Testing Dark Energy with the Advanced Liquid-Mirror Probe of Asteroids, Cosmology and Astrophysics

    NASA Astrophysics Data System (ADS)

    LoVerde, M.; Corasaniti, P. S.; Crotts, A.; Blake, C.

    2006-06-01

    The Advanced Liquid-Mirror Probe of Asteroids, Cosmology and Astrophysics (ALPACA) is a proposed 8-meter liquid mirror telescope surveying ˜ 1000 deg2 of the southern-hemisphere sky. It will be a remarkably simple and inexpensive telescope that will nonetheless deliver a powerful sample of optical data for studying dark energy. The bulk of the cosmological data consists of nightly, high signal-to-noise, multiband light curves of SN Ia. At the end of the three-year run ALPACA is expected to collect ˜ 100,000 SN Ia up to z ˜ 1. This will allow accurate calibration of the standard-candle relation and reduce the systematic uncertainties. The survey will also provide several other datasets such as the detection of baryon acoustic oscillations in the matter power spectrum and shear weak lensing measurements. In this preliminary analysis we forecast constraints on dark energy parameters from SN Ia and baryon acoustic oscillations. The combination of these two datasets will provide competitive constraints on the dark energy parameters with minimal prior assumptions. Further studies are needed to address the accuracy of weak lensing measurements.

  2. Testing dark energy with the Advanced Liquid-mirror Probe of Asteroids, Cosmology and Astrophysics

    NASA Astrophysics Data System (ADS)

    Corasaniti, Pier Stefano; LoVerde, Marilena; Crotts, Arlin; Blake, Chris

    2006-06-01

    The Advanced Liquid-mirror Probe of Asteroids, Cosmology and Astrophysics (ALPACA) is a proposed 8-m liquid-mirror telescope surveying ~1000deg2 of the Southern hemisphere sky. It will be a remarkably simple and inexpensive telescope that none the less will deliver a powerful sample of optical data for studying dark energy. The bulk of the cosmological data consist of nightly, high signal-to-noise ratio, multiband light curves of Type Ia supernovae (SNe Ia). At the end of the 3-yr run, ALPACA is expected to collect >~100000 SNe Ia up to z ~ 1. This will allow us to reduce present systematic uncertainties affecting the standard-candle relation. The survey will also provide several other data sets such as the detection of baryon acoustic oscillations in the matter power spectrum and shear weak-lensing measurements. In this preliminary analysis, we forecast constraints on dark energy parameters from SNe Ia and baryon acoustic oscillations. The combination of these two data sets will provide competitive constraints on the dark energy parameters under minimal prior assumptions. Further studies are needed to address the accuracy of weak-lensing measurements.

  3. Solid-liquid interface free energies of pure bcc metals and B2 phases

    DOE PAGESBeta

    Wilson, S. R.; Gunawardana, K. G. S. H.; Mendelev, M. I.

    2015-04-07

    The solid-liquid interface (SLI) free energy was determined from molecular dynamics (MD) simulation for several body centered cubic (bcc) metals and B2 metallic compounds (space group: Pm3¯m ; prototype: CsCl). In order to include a bcc metal with a low melting temperature in our study, a semi-empirical potential was developed for Na. Two additional synthetic “Na” potentials were also developed to explore the effect of liquid structure and latent heat on the SLI free energy. The obtained MD data were compared with the empirical Turnbull, Laird, and Ewing relations. All three relations are found to predict the general trend observedmore » in the MD data for bcc metals obtained within the present study. However, only the Laird and Ewing relations are able to predict the trend obtained within the sequence of “Na” potentials. The Laird relation provides the best prediction for our MD data and other MD data for bcc metals taken from the literature. Overall, the Laird relation also agrees well with our B2 data but requires a proportionality constant that is substantially different from the bcc case. It also fails to explain a considerable difference between the SLI free energies of some B2 phases which have nearly the same melting temperature. In contrast, this difference is satisfactorily described by the Ewing relation. Thus, the Ewing relation obtained from the bcc dataset also provides a reasonable description of the B2 data.« less

  4. Solid-liquid interface free energies of pure bcc metals and B2 phases

    SciTech Connect

    Wilson, S. R.; Gunawardana, K. G. S. H.; Mendelev, M. I.

    2015-04-07

    The solid-liquid interface (SLI) free energy was determined from molecular dynamics (MD) simulation for several body centered cubic (bcc) metals and B2 metallic compounds (space group: Pm3¯m ; prototype: CsCl). In order to include a bcc metal with a low melting temperature in our study, a semi-empirical potential was developed for Na. Two additional synthetic “Na” potentials were also developed to explore the effect of liquid structure and latent heat on the SLI free energy. The obtained MD data were compared with the empirical Turnbull, Laird, and Ewing relations. All three relations are found to predict the general trend observed in the MD data for bcc metals obtained within the present study. However, only the Laird and Ewing relations are able to predict the trend obtained within the sequence of “Na” potentials. The Laird relation provides the best prediction for our MD data and other MD data for bcc metals taken from the literature. Overall, the Laird relation also agrees well with our B2 data but requires a proportionality constant that is substantially different from the bcc case. It also fails to explain a considerable difference between the SLI free energies of some B2 phases which have nearly the same melting temperature. In contrast, this difference is satisfactorily described by the Ewing relation. Thus, the Ewing relation obtained from the bcc dataset also provides a reasonable description of the B2 data.

  5. Synthesis and crystal structure of a new N-(2,6-dichlorobenzoyl)- N', N″-bis(pyrrolidinyl)-phosphoric triamide as a carrier and competitive bulk liquid membrane transport of six metal cations

    NASA Astrophysics Data System (ADS)

    Khoshnood, Razieh Sanavi; Pourayoubi, Mehrdad; Kasraee, Farideh; Toghraee, Maryam; Dušek, M.; Bereciartua, P. J.

    2014-12-01

    The competitive metal ion transport experiments of Co+2, Cd+2, Ag+, Pb+2, Ni+2, and Cu+2 were carried out by N-(2,6-dichlorobenzoyl)- N', N″-bis(pyrrolidinyl)-phosphoric triamide as a carrier in organic membrane phase. 2,6-Cl2C6H3C(O)NHP(O)[NC4H8]2 has been synthesized and characterized by mass spectrometry IR spectroscopy and single crystal X-ray diffraction. The asymmetric unit of title phosphoric triamide contains one symmetrically independent molecule. The source phase contained equimolar concentrations of metal ions at pH 5 and the receiving phase being buffered at pH 3. The following solvents were examined as membrane: chloroform (CHCl3), nitrobenzene (NB), 1,2-dichloroethane (1,2-DCE), dichloromethane (DCM), dichloromethane/1,2-dichloroethane (DCM/1,2-DCE). The obtained results show that the selectivity and efficiency of transport for these heavy metal cations change with the nature of the ligand and also the organic solvents, which were used as liquid membrane in these experiments. A good selectivity was observed for Pb+2 cation by this ligand in all membrane systems. Moreover, the selectivity of metal cations in DCM is higher than other solvents. A non-linear relationship was found between the percent of transport of Pb+2 cation by this ligand and the compositions of DCM/1,2-DCE and binary solution by this ligand. The effect of several factors such as the nature of carboxylic acids (stearic, fumaric and maleic acid) as surfactant in the membrane phase and the time of transport on transport efficiency of Pb+2 cation were investigated.

  6. Liquid xenon gamma-ray imaging telescope (LXeGRIT) for medium energy astrophysics

    NASA Astrophysics Data System (ADS)

    Aprile, Elena; Egorov, Valeri; Xu, Fang; Chupp, Edward L.; Dunphy, Philip; Doke, Tadayoshi; Kikuchi, Jun; Fishman, Gerald J.; Pendleton, Geoffrey N.; Masuda, Kimiaki; Kashiwagi, Toshisuke

    1996-10-01

    As part of our ongoing research program to develop a liquid xenon gamma-ray imaging telescope (LXe-GRIT) for medium energy astrophysics, we have built a liquid xenon time projection chamber (LXeTPC) with a total volume of 10 liters and a sensitive are of 20 cm by 20 cm. The detector has been successfully tested with gamma-ray sources in the laboratory and is currently being prepared as balloon-borne payload for imaging MeV gamma-ray emission from the Crab Nebula, Cygnus X-1 and the Orion molecular cloud region. The LXe-TPC, sensitive to gamma-rays from 300 keV to 30 MeV, measures the energy and the 3-D location of each gamma-ray interaction with a resolution of 6% FWHM and 1 mm RMS at 1 MeV, within a 1 sr FOV. Its detection efficiency for Compton events is about 4% in the 1 - 3 MeV, an energy band of great astrophysical interest for both continuum and line emission. Its 3 sigma continuum sensitivity of 1.8 multiplied by 10(superscript -7) ph cm(superscript -2)s(superscript -1)keV(superscript -1) for a nominal 10 hr observation time, will allow us to study a variety of sources with an imaging accuracy as good as 1 degree. We plan to pursue a vigorous program of balloon flights with this telescope to achieve the maximum science return while continuing a strong R&D laboratory program on LXe technology. The ultimate goal is an optimized design of a satellite implementation of a liquid xenon gamma-ray imaging instrument that will lead to drastic improvements in sensitivity and angular resolution in the 0.3 - 30 MeV band and beyond.

  7. Highly polarized emission of the liquid crystalline conjugated polymer by controlling the surface anchoring energy

    NASA Astrophysics Data System (ADS)

    In Jo, Soo; Kim, Youngsik; Baek, Ji-Ho; Yu, Chang-Jae; Kim, Jae-Hoon

    2014-01-01

    We demonstrated a highly polarized organic light-emitting diode (OLED) through the enhancement of the orientational ordering of the emitting polymer with a nematic liquid crystalline (LC) phase. The highly ordered state of the conjugate polymer was obtained by thermal annealing at the nematic temperature and strong azimuthal anchoring energy of the underlying polyimide. The order parameter of the conjugate polymer was analyzed using a second-harmonic generation model and the dichroic ratio was measured to be 22 : 1. Also, we applied our optimized OLED with high optical polarizability to an effective light source for a twisted nematic LC display.

  8. Lithium-antimony-lead liquid metal battery for grid-level energy storage.

    PubMed

    Wang, Kangli; Jiang, Kai; Chung, Brice; Ouchi, Takanari; Burke, Paul J; Boysen, Dane A; Bradwell, David J; Kim, Hojong; Muecke, Ulrich; Sadoway, Donald R

    2014-10-16

    The ability to store energy on the electric grid would greatly improve its efficiency and reliability while enabling the integration of intermittent renewable energy technologies (such as wind and solar) into baseload supply. Batteries have long been considered strong candidate solutions owing to their small spatial footprint, mechanical simplicity and flexibility in siting. However, the barrier to widespread adoption of batteries is their high cost. Here we describe a lithium-antimony-lead liquid metal battery that potentially meets the performance specifications for stationary energy storage applications. This Li||Sb-Pb battery comprises a liquid lithium negative electrode, a molten salt electrolyte, and a liquid antimony-lead alloy positive electrode, which self-segregate by density into three distinct layers owing to the immiscibility of the contiguous salt and metal phases. The all-liquid construction confers the advantages of higher current density, longer cycle life and simpler manufacturing of large-scale storage systems (because no membranes or separators are involved) relative to those of conventional batteries. At charge-discharge current densities of 275 milliamperes per square centimetre, the cells cycled at 450 degrees Celsius with 98 per cent Coulombic efficiency and 73 per cent round-trip energy efficiency. To provide evidence of their high power capability, the cells were discharged and charged at current densities as high as 1,000 milliamperes per square centimetre. Measured capacity loss after operation for 1,800 hours (more than 450 charge-discharge cycles at 100 per cent depth of discharge) projects retention of over 85 per cent of initial capacity after ten years of daily cycling. Our results demonstrate that alloying a high-melting-point, high-voltage metal (antimony) with a low-melting-point, low-cost metal (lead) advantageously decreases the operating temperature while maintaining a high cell voltage. Apart from the fact that this

  9. Network Analysis of Free Energy Landscape of Metastable States of Hexatic Smectic B Liquid Crystal

    NASA Astrophysics Data System (ADS)

    Aoki, Keiko M.

    2014-10-01

    The topology of the free-energy landscape of a model system, which gives rise to multiple metastable states of hexatic smectic B (HexB) liquid crystals, is investigated using network theory. Directed and weighted networks of HexB states are constructed from a series of dynamical data calculated by constant-pressure and constant-temperature molecular dynamics simulations. The k-shell decomposition is extended to directed networks, and the networks of HexB metastable states are analyzed. Singular values of the weighted adjacency matrix, with elements consisting of the weight of the directed edge, are used to distinguish important vertices for evolution.

  10. Solidification Processing of Immiscible Liquids in the Presence of Applied Ultrasonic Energy

    NASA Technical Reports Server (NTRS)

    Grugel, R. N.; Fedoseyev, A. I.; Kim, S.

    2001-01-01

    Uniform microstructural distribution during solidification of immiscible liquids (e.g., oil and water; aluminum and lead) on Earth is hampered by inherent density differences between the phases. Microgravity processing minimizes settling but segregation still occurs due to gravity independent wetting and coalescence phenomena. Experiments with the transparent organic, metal analogue, succinonitrile-glycerol system were conducted in conjunction with applied ultrasonic energy. The processing parameters associated with this technique have been evaluated in view of optimizing dispersion uniformity. Characterization of the experimental results in terms of a modeling effort will also be presented,

  11. An energy dispersive x-ray scattering and molecular dynamics study of liquid dimethyl carbonate

    NASA Astrophysics Data System (ADS)

    Gontrani, Lorenzo; Russina, Olga; Marincola, Flaminia Cesare; Caminiti, Ruggero

    2009-12-01

    In this work, we report on the first x-ray diffraction study on liquid dimethyl carbonate. Diffraction spectra were collected with an energy-dispersive instrument, whose wide Q-range allows the structure determination of weakly ordered systems (such as liquids). The structural correlation in this liquid ranges up to about 20 Å. The observed patterns are interpreted with a structural model derived from classical molecular dynamics simulations. The simulations were run using OPLS force field, only slightly modified to restrain bond distances to the experimental values. The model structure function and radial distribution functions, averaged among the productive trajectory frames, are in very good agreement with the corresponding experimental ones. Molecular dynamics results show that the deviations from C2v cis-cis structure, predicted by ab initio calculations and observed by electron diffraction in the gas phase, are small. By analyzing the intra- and intermolecular pair distribution functions, it was possible to assign the peaks of the experimental radial distribution function to specific structural correlations, and to compute the different average intermolecular coordination numbers. The intermolecular methyl-carbonyl oxygen distance is thoroughly discussed to assess the presence of weak C-H⋯ṡO hydrogen bonds.

  12. Self-healing Li-Bi liquid metal battery for grid-scale energy storage

    SciTech Connect

    Ning, XH; Phadke, S; Chung, B; Yin, HY; Burke, P; Sadoway, DR

    2015-02-01

    In an assessment of the performance of a Li vertical bar LiCl-LiF vertical bar Bi liquid metal battery, increasing the current density from 200 to 1250 mA cm(-2) results in a less than 30% loss in specific discharge capacity at 550 degrees C. The charge and discharge voltage profiles exhibit two distinct regions: one corresponding to a Li-Bi liquid alloy and one corresponding to the two-phase mixture of Li-Bi liquid alloy and the intermetallic solid compound, Li3Bi. Full cell prototypes of 0.1 Ah nameplate capacity have been assembled and cycled at 3 C rate for over a 1000 cycles with only 0.004% capacity fade per cycle. This is tantamount to retention of over 85% of original capacity after 10 years of daily cycling. With minimal changes in design, cells of 44.8 Ah and 134 Ah capacity have been fabricated and cycled at C/3 rate. After a hundred cycles and over a month of testing, no capacity fade is observed. The coulombic efficiency of 99% and energy efficiency of 70% validate the ease of scalability of this battery chemistry. Post mortem cross sections of the cells in various states of charge demonstrate the total reversibility of the Li3Bi solid phase formed at high degrees of lithiation. (C) 2014 Elsevier B.V. All rights reserved.

  13. Ultrafast memory loss and energy redistribution in the hydrogen bond network of liquid H2O

    NASA Astrophysics Data System (ADS)

    Cowan, M. L.; Bruner, B. D.; Huse, N.; Dwyer, J. R.; Chugh, B.; Nibbering, E. T. J.; Elsaesser, T.; Miller, R. J. D.

    2005-03-01

    Many of the unusual properties of liquid water are attributed to its unique structure, comprised of a random and fluctuating three-dimensional network of hydrogen bonds that link the highly polar water molecules. One of the most direct probes of the dynamics of this network is the infrared spectrum of the OH stretching vibration, which reflects the distribution of hydrogen-bonded structures and the intermolecular forces controlling the structural dynamics of the liquid. Indeed, water dynamics has been studied in detail, most recently using multi-dimensional nonlinear infrared spectroscopy for acquiring structural and dynamical information on femtosecond timescales. But owing to technical difficulties, only OH stretching vibrations in D2O or OD vibrations in H2O could be monitored. Here we show that using a specially designed, ultrathin sample cell allows us to observe OH stretching vibrations in H2O. Under these fully resonant conditions, we observe hydrogen bond network dynamics more than one order of magnitude faster than seen in earlier studies that include an extremely fast sweep in the OH frequencies on a 50-fs timescale and an equally fast disappearance of the initial inhomogeneous distribution of sites. Our results highlight the efficiency of energy redistribution within the hydrogen-bonded network, and that liquid water essentially loses the memory of persistent correlations in its structure within 50fs.

  14. The Liquid Droplet Radiator - an Ultralightweight Heat Rejection System for Efficient Energy Conversion in Space

    NASA Technical Reports Server (NTRS)

    Mattick, A. T.; Hertzberg, A.

    1984-01-01

    A heat rejection system for space is described which uses a recirculating free stream of liquid droplets in place of a solid surface to radiate waste heat. By using sufficiently small droplets ( 100 micron diameter) of low vapor pressure liquids the radiating droplet sheet can be made many times lighter than the lightest solid surface radiators (heat pipes). The liquid droplet radiator (LDR) is less vulnerable to damage by micrometeoroids than solid surface radiators, and may be transported into space far more efficiently. Analyses are presented of LDR applications in thermal and photovoltaic energy conversion which indicate that fluid handling components (droplet generator, droplet collector, heat exchanger, and pump) may comprise most of the radiator system mass. Even the unoptimized models employed yield LDR system masses less than heat pipe radiator system masses, and significant improvement is expected using design approaches that incorporate fluid handling components more efficiently. Technical problems (e.g., spacecraft contamination and electrostatic deflection of droplets) unique to this method of heat rejectioon are discussed and solutions are suggested.

  15. The liquid droplet radiator - An ultralightweight heat rejection system for efficient energy conversion in space

    NASA Technical Reports Server (NTRS)

    Mattick, A. T.; Hertzberg, A.

    1981-01-01

    A heat rejection system for space is described which uses a recirculating free stream of liquid droplets in place of a solid surface to radiate waste heat. By using sufficiently small droplets (less than about 100 micron diameter) of low vapor pressure liquids (tin, tin-lead-bismuth eutectics, vacuum oils) the radiating droplet sheet can be made many times lighter than the lightest solid surface radiators (heat pipes). The liquid droplet radiator (LDR) is less vulnerable to damage by micrometeoroids than solid surface radiators, and may be transported into space far more efficiently. Analyses are presented of LDR applications in thermal and photovoltaic energy conversion which indicate that fluid handling components (droplet generator, droplet collector, heat exchanger, and pump) may comprise most of the radiator system mass. Even the unoptimized models employed yield LDR system masses less than heat pipe radiator system masses, and significant improvement is expected using design approaches that incorporate fluid handling components more efficiently. Technical problems (e.g., spacecraft contamination and electrostatic deflection of droplets) unique to this method of heat rejection are discussed and solutions are suggested.

  16. DEVELOPMENT OF ATOM-ECONOMICAL CATALYTIC PATHWAYS FOR CONVERSIONS OF SYNGAS TO ENERGY LIQUIDS

    SciTech Connect

    MAHAJAN,D.; WEGRZYN,J.E.; LEE,T.; GUREVICH,M.

    1999-03-01

    The subject of catalytic syngas conversions to fuels and chemicals is well studied (1--3). But globally, the recent focus is on development of technologies that offer an economical route to desired products (4). Economical transport of natural gas from remote locations and within clathrate hydrates is of continuing interest at Brookhaven National Laboratory (BNL). Under this project, a Liquid Phase Low Temperature (LPLT) concept is being applied to attain highly efficient transformations of natural-gas derived syngas to specific products. Furthermore, a more precise term ``Atom Economy'' has been recently introduced by Trost to describe development of highly efficient homogeneously catalyzed synthesis of organic molecules (5). Taken from reference 5, the term ``Atom Economy'' is defined as maximizing the number of atoms of all raw materials that end up in the product with any other reactant required on in catalytic amount. For application to methane transformations that may involve one or more steps, atom economy of each of these steps is critical. The authors, therefore, consider atom-economy synonymous with overall energy efficiency of a process. This paper describes potential liquid products from catalytic syngas conversions, i.e. gas to liquids (GTL) technologies and process considerations that are necessary for economical transport of natural gas. As such, the present study defines an atom-economical standard to directly compare competing GTL technologies.

  17. Evaluation of the mean energy deposit during the impact of charged particles on liquid water

    NASA Astrophysics Data System (ADS)

    Bernal, M. A.

    2012-04-01

    The DNA strand break yield due to the impact of ionizing particles on living beings is closely related to the number of inelastic events per unit absorbed dose produced by these particles. The higher this number, the higher the probability of causing DNA strand breaks per unit absorbed dose. In a previous work, it was found that the total number of events produced by primary particles and the secondary electrons is almost independent of the type and energy of the incident particle (or LET). This finding could be supported by a quasi-constant mean energy deposit by inelastic event (\\bar{\\varepsilon }). In this work, \\bar{\\varepsilon } was defined and determined for electrons and the non-negative charge states of hydrogen (H0, +) and helium (He0, +, 2 +) species impacting on liquid water. Ionization, excitation and charge transfer (up to two-electron transfers) processes have been included in present calculations. We found that, for liquid water, \\bar{\\varepsilon } is within 13.7 ± 4.1 eV, 14.2 ± 1.7 eV and 13.8 ± 1.4 eV for electrons, hydrogen and helium species, respectively, with impact energies changing over three orders of magnitude. Unlike the mean excitation energy, the mean energy deposit per inelastic event depends not only on the target molecule but also on the projectile features. However, this dependence is relatively weak. This fact supports the quasi-independent number of inelastic events per unit absorbed dose found previously when charged particles impact on matter.

  18. Designing molecular complexes using free-energy derivatives from liquid-state integral equation theory.

    PubMed

    Mrugalla, Florian; Kast, Stefan M

    2016-09-01

    Complex formation between molecules in solution is the key process by which molecular interactions are translated into functional systems. These processes are governed by the binding or free energy of association which depends on both direct molecular interactions and the solvation contribution. A design goal frequently addressed in pharmaceutical sciences is the optimization of chemical properties of the complex partners in the sense of minimizing their binding free energy with respect to a change in chemical structure. Here, we demonstrate that liquid-state theory in the form of the solute-solute equation of the reference interaction site model provides all necessary information for such a task with high efficiency. In particular, computing derivatives of the potential of mean force (PMF), which defines the free-energy surface of complex formation, with respect to potential parameters can be viewed as a means to define a direction in chemical space toward better binders. We illustrate the methodology in the benchmark case of alkali ion binding to the crown ether 18-crown-6 in aqueous solution. In order to examine the validity of the underlying solute-solute theory, we first compare PMFs computed by different approaches, including explicit free-energy molecular dynamics simulations as a reference. Predictions of an optimally binding ion radius based on free-energy derivatives are then shown to yield consistent results for different ion parameter sets and to compare well with earlier, orders-of-magnitude more costly explicit simulation results. This proof-of-principle study, therefore, demonstrates the potential of liquid-state theory for molecular design problems. PMID:27366935

  19. Designing molecular complexes using free-energy derivatives from liquid-state integral equation theory

    NASA Astrophysics Data System (ADS)

    Mrugalla, Florian; Kast, Stefan M.

    2016-09-01

    Complex formation between molecules in solution is the key process by which molecular interactions are translated into functional systems. These processes are governed by the binding or free energy of association which depends on both direct molecular interactions and the solvation contribution. A design goal frequently addressed in pharmaceutical sciences is the optimization of chemical properties of the complex partners in the sense of minimizing their binding free energy with respect to a change in chemical structure. Here, we demonstrate that liquid-state theory in the form of the solute–solute equation of the reference interaction site model provides all necessary information for such a task with high efficiency. In particular, computing derivatives of the potential of mean force (PMF), which defines the free-energy surface of complex formation, with respect to potential parameters can be viewed as a means to define a direction in chemical space toward better binders. We illustrate the methodology in the benchmark case of alkali ion binding to the crown ether 18-crown-6 in aqueous solution. In order to examine the validity of the underlying solute–solute theory, we first compare PMFs computed by different approaches, including explicit free-energy molecular dynamics simulations as a reference. Predictions of an optimally binding ion radius based on free-energy derivatives are then shown to yield consistent results for different ion parameter sets and to compare well with earlier, orders-of-magnitude more costly explicit simulation results. This proof-of-principle study, therefore, demonstrates the potential of liquid-state theory for molecular design problems.

  20. Hot carrier solar cell absorbers: investigation of carrier cooling properties of candidate materials

    NASA Astrophysics Data System (ADS)

    Conibeer, G.; Shrestha, Santosh; Huang, Shujuan; Patterson, Robert; Xia, Hongze; Feng, Yu; Zhang, Pengfei; Gupta, Neeti; Smyth, Suntrana; Liao, Yuanxun; Lin, Shu; Wang, Pei; Dai, Xi; Chung, Simon; Yang, Jianfeng; Zhang, Yi

    2015-09-01

    The hot carrier cell aims to extract the electrical energy from photo-generated carriers before they thermalize to the band edges. Hence it can potentially achieve a high current and a high voltage and hence very high efficiencies up to 65% under 1 sun and 86% under maximum concentration. To slow the rate of carrier thermalisation is very challenging, but modification of the phonon energies and the use of nanostructures are both promising ways to achieve some of the required slowing of carrier cooling. A number of materials and structures are being investigated with these properties and test structures are being fabricated. Initial measurements indicate slowed carrier cooling in III-Vs with large phonon band gaps and in multiple quantum wells. It is expected that soon proof of concept of hot carrier devices will pave the way for their development to fully functioning high efficiency solar cells.

  1. 9. VIEW OF CLOSED CARRIER LINES FOR MOVING CONTAMINATED PROCESS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. VIEW OF CLOSED CARRIER LINES FOR MOVING CONTAMINATED PROCESS FILTERS AND TRANSPORTING SOLID AND LIQUID MATERIAL SAMPLES. (9/10/96) - Rocky Flats Plant, Plutonium Recovery Facility, Northwest portion of Rocky Flats Plant, Golden, Jefferson County, CO

  2. A G/NARRLI Effort. Measuring the Ionization Yield of Low-Energy Nuclear Recoils in Liquid Argon

    SciTech Connect

    Joshi, Tenzing Henry Yatish

    2014-01-01

    Liquid argon has long been used for particle detection due to its attractive drift properties, ample abundance, and reasonable density. The response of liquid argon to lowenergy O(102 -1044 eV) interactions is, however, largely unexplored. Weakly interacting massive particles such as neutrinos and hypothetical dark-matter particles (WIMPs) are predicted to coherently scatter on atomic nuclei, leaving only an isolated low-energy nuclear recoil as evidence. The response of liquid argon to low-energy nuclear recoils must be studied to determine the sensitivity of liquid argon based detectors to these unobserved interactions. Detectors sensitive to coherent neutrino-nucleus scattering may be used to monitor nuclear reactors from a distance, to detect neutrinos from supernova, and to test the predicted behavior of neutrinos. Additionally, direct detection of hypothetical weakly interacting dark matter would be a large step toward understanding the substance that accounts for nearly 27% of the universe. In this dissertation I discuss a small dual-phase (liquid-gas) argon proportional scintillation counter built to study the low-energy regime and several novel calibration and characterization techniques developed to study the response of liquid argon to low-energy O(102 -104 eV) interactions.

  3. Functions and potential applications of glycolipid biosurfactants--from energy-saving materials to gene delivery carriers.

    PubMed

    Kitamoto, Dai; Isoda, Hiroko; Nakahara, Tadaatsu

    2002-01-01

    Biosurfactants (BS) produced by various microorganisms show unique properties (e.g., mild production conditions, lower toxicity, higher biodegradability and environmental compatibility) compared to their chemical counterparts. The numerous advantages of BS have prompted applications not only in the food, cosmetic, and pharmaceutical industries but in environmental protection and energy-saving technology as well. Glycolipid BS are the most promising, due to high productivity from renewable resources and versatile biochemical properties. Mannosylerythritol lipids (MEL), which are glycolipid BS produced by a yeast Candida antarctrica, exhibit not only excellent interfacial properties but also remarkable differentiation-inducing activities against human leukemia cells. MEL also show a potential anti-agglomeration effect on ice particles in ice slurry used for cold thermal storage. Recently, the cationic liposome bearing MEL has been demonstrated to increase dramatically the efficiency of gene transfection into mammalian cells. These features of BS should broaden its applications in new advanced technologies. The current status of research and development on glycolipid BS, especially their function and potential applications, is discussed. PMID:16233292

  4. An investigation into membrane bound redox carriers involved in energy transduction mechanism in Brevibacterium linens DSM 20158 with unsequenced genome.

    PubMed

    Shabbiri, Khadija; Botting, Catherine H; Adnan, Ahmad; Fuszard, Matthew; Naseem, Shahid; Ahmed, Safeer; Shujaat, Shahida; Syed, Quratulain; Ahmad, Waqar

    2014-04-01

    Brevibacterium linens (B. linens) DSM 20158 with an unsequenced genome can be used as a non-pathogenic model to study features it has in common with other unsequenced pathogens of the same genus on the basis of comparative proteome analysis. The most efficient way to kill a pathogen is to target its energy transduction mechanism. In the present study, we have identified the redox protein complexes involved in the electron transport chain of B. linens DSM 20158 from their clear homology with the shot-gun genome sequenced strain BL2 of B. linens by using the SDS-Polyacrylamide gel electrophoresis coupled with nano LC-MS/MS mass spectrometry. B. linens is found to have a branched electron transport chain (Respiratory chain), in which electrons can enter the respiratory chain either at NADH (Complex I) or at Complex II level or at the cytochrome level. Moreover, we are able to isolate, purify, and characterize the membrane bound Complex II (succinate dehydrogenase), Complex III (menaquinone cytochrome c reductase cytochrome c subunit, Complex IV (cytochrome c oxidase), and Complex V (ATP synthase) of B. linens strain DSM 20158. PMID:24573306

  5. In-situ High-energy X-ray Diffraction Study of the Local Structure of Supercooled Liquid Si

    NASA Technical Reports Server (NTRS)

    Lee, G. W.; Kim, T. H.; Sieve, B.; Gangopadhyay, A. K.; Hyers, R. W.; Rathz, T. J.; Rogers, J. R.; Robinson, D. S.; Kelton, K. F.; Goldman, A. I.

    2005-01-01

    While changes in the coordination number for liquid silicon upon supercooling, signaling an underlying liquid-liquid phase transition, have been predicted, x-ray and neutron measurements have produced conflicting reports. In particular some studies have found an increase in the first shell coordination as temperature decreases in the supercooled regime, while others have reported increases in the coordination number with decreasing temperature. Employing the technique of electrostatic levitation coupled with high energy x-ray diffraction (125 keV), and rapid data acquisition (100ms collection times) using an area detector, we have obtained high quality structural data more deeply into the supercooled regime than has been possible before. No change in coordination number is observed in this temperature region, calling into question previous experimental claims of structural evidence for the existence of a liquid-liquid phase transition.

  6. Development of a High Resolution Liquid Xenon Imaging Telescope for Medium Energy Gamma Ray Astrophysics

    NASA Technical Reports Server (NTRS)

    Aprile, Elena

    1992-01-01

    In the third year of the research project, we have (1) tested a 3.5 liter prototype of the Liquid Xenon Time Projection Chamber, (2) used a prototype having a 4.4 cm drift gap to study the charge and energy resolution response of the 3.5 liter chamber, (3) obtained an energy resolution as good as that previously measured by us using chambers with drift gaps of the order of millimeters, (4) observed the induction signals produced by MeV gamma rays, (4) used the 20 hybrid charge sensitive preamplifiers for a nondestructive readout of the electron image on the induction wires, (5) performed extensive Monte Carlo simulations to obtain results on efficiency, background rejection capability, and source flux sensitivity, and (6) developed a reconstruction algorithm for events with multiple interaction points.

  7. Liquid lithium target as a high intensity, high energy neutron source

    DOEpatents

    Parkin, Don M.; Dudey, Norman D.

    1976-01-01

    This invention provides a target jet for charged particles. In one embodiment the charged particles are high energy deuterons that bombard the target jet to produce high intensity, high energy neutrons. To this end, deuterons in a vacuum container bombard an endlessly circulating, free-falling, sheet-shaped, copiously flowing, liquid lithium jet that gushes by gravity from a rectangular cross-section vent on the inside of the container means to form a moving web in contact with the inside wall of the vacuum container. The neutrons are produced via break-up of the beam in the target by stripping, spallation and compound nuclear reactions in which the projectiles (deuterons) interact with the target (Li) to produce excited nuclei, which then "boil off" or evaporate a neutron.

  8. Perturbation theory of liquid-metal surfaces: The importance of the self-energy

    NASA Astrophysics Data System (ADS)

    Foiles, S. M.; Ashcroft, N. W.

    1984-12-01

    A model for the surface tension and density profile of simple liquid metals is presented. It is based on second-order perturbation theory in the electron-ion pseudopotential about the inhomogeneous electron gas at a jellium surface. The pair correlations in the ion fluid are computed using hard-sphere perturbation theory. The model yields good agreement with the experimental surface tensions of the alkali metals. For the polyvalent metals it is shown that it is essential to include the position-dependent self-energy of the ions, a quantity that is fortuitously small in the monovalent systems. To obtain such self-energies, very accurate values of the response function of the inhomogeneous electron gas are required.

  9. Liquid-Desiccant Vapor Separation Reduces the Energy Requirements of Atmospheric Moisture Harvesting.

    PubMed

    Gido, Ben; Friedler, Eran; Broday, David M

    2016-08-01

    An innovative atmospheric moisture harvesting system is proposed, where water vapor is separated from the air prior to cooling and condensation. The system was studied using a model that simulates its three interconnected cycles (air, desiccant, and water) over a range of ambient conditions, and optimal configurations are reported for different operation conditions. Model results were compared to specifications of commercial atmospheric moisture harvesting systems and found to represent saving of 5-65% of the electrical energy requirements due to the vapor separation process. We show that the liquid desiccant separation stage that is integrated into atmospheric moisture harvesting systems can work under a wide range of environmental conditions using low grade or solar heating as a supplementary energy source, and that the performance of the combined system is superior. PMID:27435379

  10. Glasses and Liquids Low on the Energy Landscape Prepared by Physical Vapor Deposition

    NASA Astrophysics Data System (ADS)

    Dalal, Shakeel; Fakhraai, Zahra; Ediger, Mark

    2014-03-01

    The lower portions of the potential energy landscape for glass-forming materials such as polymers and small molecules were historically inaccessible by experiments. Physical vapor deposition is uniquely able to prepare materials in this portion of the energy landscape, with the properties of the deposited material primarily modulated by the substrate temperature. Here we report on high-throughput experiments which utilize a temperature gradient stage to enable rapid screening of vapor-deposited organic glasses. Using ellipsometry, we characterize a 100 K range of substrate temperatures in a single experiment, allowing us to rapidly determine the density, kinetic stability, fictive temperature and molecular orientation of these glasses. Their properties fall into three temperature regimes. At substrate temperatures as low as 0.97Tg, we prepare materials which are equivalent to the supercooled liquid produced by cooling the melt. Below 0.9Tg (1.16TK) the properties of materials are kinetically controlled and highly tunable. At intermediate substrate temperatures we are able to produce materials whose bulk properties match those expected for the equilibrium supercooled liquid, down to 1.16TK, but are structurally anisotropic.

  11. Low energy nuclear recoils study in noble liquids for low-mass WIMPs

    NASA Astrophysics Data System (ADS)

    Wang, Lu; Mei, Dongming

    2014-03-01

    Detector response to low-energy nuclear recoils is critical to the detection of low-mass dark matter particles-WIMPs (Weakly interacting massive particles). Although the detector response to the processes of low-energy nuclear recoils is subtle and direct experimental calibration is rather difficult, many studies have been performed for noble liquids, NEST is a good example. However, the response of low-energy nuclear recoils, as a critical issue, needs more experimental data, in particular, with presence of electric field. We present a new design using time of flight to calibrate the large-volume xenon detector, such as LUX-Zeplin (LZ) and Xenon1T, energy scale for low-energy nuclear recoils. The calculation and physics models will be discussed based on the available data to predict the performance of the calibration device and set up criteria for the design of the device. A small test bench is built to verify the concepts at The University of South Dakota. This work is supported by DOE grant DE-FG02-10ER46709 and the state of South Dakota.

  12. Electrochemical energy storage in montmorillonite K10 clay based composite as supercapacitor using ionic liquid electrolyte.

    PubMed

    Maiti, Sandipan; Pramanik, Atin; Chattopadhyay, Shreyasi; De, Goutam; Mahanty, Sourindra

    2016-02-15

    Exploring new electrode materials is the key to realize high performance energy storage devices for effective utilization of renewable energy. Natural clays with layered structure and high surface area are prospective materials for electrical double layer capacitors (EDLC). In this work, a novel hybrid composite based on acid-leached montmorillonite (K10), multi-walled carbon nanotube (MWCNT) and manganese dioxide (MnO2) was prepared and its electrochemical properties were investigated by fabricating two-electrode asymmetric supercapacitor cells against activated carbon (AC) using 1.0M tetraethylammonium tetrafluroborate (Et4NBF4) in acetonitrile (AN) as electrolyte. The asymmetric supercapacitors, capable of operating in a wide potential window of 0.0-2.7V, showed a high energy density of 171Whkg(-1) at a power density of ∼1.98kWkg(-1). Such high EDLC performance could possibly be linked to the acid-base interaction of K10 through its surface hydroxyl groups with the tetraethylammonium cation [(C2H5)4N(+) or TEA(+)] of the ionic liquid electrolyte. Even at a very high power density of 96.4kWkg(-1), the cells could still deliver an energy density of 91.1Whkg(-1) exhibiting an outstanding rate capability. The present study demonstrates for the first time, the excellent potential of clay-based composites for high power energy storage device applications. PMID:26609925

  13. Storing solar energy with liquid phase Diels-Alder reactions. Final report

    SciTech Connect

    Poling, B.E.

    1983-07-28

    At the beginning of this project, a preliminary study was completed that indicated the Diels-Alder reaction between maleic anhydride and 2 methyl furan had an energy storage capacity greater than water. During the last two years when this grant was in effect, three additional projects have been completed. First, an improved calorimetric techniques was developed for determination of the energy storage capacity of a reversible liquid phase chemical reaction. This technique confirmed the validity of the earlier results for the maleic anhydride-methyl furan reaction. Second, a technique was developed for characterizing solution nonidealities for mixtures in which reversible chemical reactions occur. It was found that for the maleic anhydride-2 methyl furan reaction, these non idealities could affect equilibrium compositions by nearly 40%. Third, drop calorimetry was used as a screening method to examine sixteen reactions for their potential as energy storage candidates. Of the sixteen examined, three (all involving maleic anhydride and substituted furan) showed an increased energy storage capacity due to reaction while the remaining thirteen showed no increase. In the following report, results of these three studies are summarized. Finally, a general summary of the status of energy storage by chemical reactions is presented.

  14. Modeling ionization and recombination from low energy nuclear recoils in liquid argon

    SciTech Connect

    Foxe, Michael P.; Hagmann, Chris; Jovanovic, Igor; Bernstein, A.; Joshi, T.; Kazkaz, K.; Mozin, Vladimir V.; Pereverzev, S. V.; Sangiorgio, Samuele; Sorensen, Peter F.

    2015-09-01

    Coherent neutrino-nucleus scattering (CNNS) is an as-yet undetected, flavor-independent neutrino interaction predicted by the Standard Model. CNNS is a flavor-blind interaction, which offers potential benefits for its use in nonproliferation (nuclear reactor monitoring) and astrophysics (supernova and solar neutrinos) applications. One challenge with detecting CNNS is the low energy deposition associated with a typical CNNS nuclear recoil. In addition, nuclear recoils are predicted to result in lower ionization yields than those produced by electron recoils of the same energy. This ratio of nuclear- and electron-induced ionization, known as the nuclear quenching factor, is unknown at energies typical for CNNS interactions in liquid xenon (LXe) and liquid argon (LAr), detector media being considered for CNNS detection. While there have been recent measurements [1] of the ionization yield from nuclear recoils in LAr, there is no universal model for nuclear quenching and ionization yield. For this reason, a Monte Carlo simulation has been developed to predict the ionization yield at sub-10 keV energies. The local ionization yield of a recoiling atom in the medium is calculated first. The ejected electrons are subsequently tracked in the electric field resulting from both the local electric charges and the externally applied drift field. The dependence of the ionization yield on the drift electric field is obtained by combining the calculated ionization yield for the initial collision cascade with the electron escape probability. An updated estimate of the CNNS signal expected in a LAr detector operated near a nuclear power reactor is presented.

  15. Gas-liquid separator and method of operation

    DOEpatents

    Soloveichik, Grigorii Lev; Whitt, David Brandon

    2009-07-14

    A system for gas-liquid separation in electrolysis processes is provided. The system includes a first compartment having a liquid carrier including a first gas therein and a second compartment having the liquid carrier including a second gas therein. The system also includes a gas-liquid separator fluidically coupled to the first and second compartments for separating the liquid carrier from the first and second gases.

  16. Energy Band Gap, Intrinsic Carrier Concentration and Fermi Level of CdTe Bulk Crystal between 304 K and 1067 K

    NASA Technical Reports Server (NTRS)

    Su, Ching-Hua

    2007-01-01

    Optical transmission measurements were performed on CdTe bulk single crystal. It was found that when a sliced and polished CdTe wafer was used, a white film started to develop when the sample was heated above 530 K and the sample became opaque. Therefore, a bulk crystal of CdTe was first grown in the window area by physical vapor transport; the optical transmission was then measured and from which the energy band gap was derived between 304 and 1067 K. The band gaps of CdTe can be fit well as a function of temperature using the Varshini expression: Eg (e V) = 1.5860 - 5.9117xl0(exp -4) T(sup 2)/(T + 160). Using the band gap data, the high temperature electron-hole equilibrium was calculated numerically by assuming the Kane's conduction band structure and a heavy-hole parabolic valance band. The calculated intrinsic carrier concentrations agree well with the experimental data reported previously. The calculated intrinsic Fermi levels between 270 and 1200 K were also presented.

  17. 18 CFR 351.1 - Financial statements released by carriers.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Financial statements... REGULATORY COMMISSION, DEPARTMENT OF ENERGY ACCOUNTS UNDER THE INTERSTATE COMMERCE ACT FINANCIAL STATEMENTS RELEASED BY CARRIERS § 351.1 Financial statements released by carriers. Carriers desiring to do so...

  18. Molecular origin of high free energy barriers for alkali metal ion transfer through ionic liquid-graphene electrode interfaces.

    PubMed

    Ivaništšev, Vladislav; Méndez-Morales, Trinidad; Lynden-Bell, Ruth M; Cabeza, Oscar; Gallego, Luis J; Varela, Luis M; Fedorov, Maxim V

    2016-01-14

    In this work we study mechanisms of solvent-mediated ion interactions with charged surfaces in ionic liquids by molecular dynamics simulations, in an attempt to reveal the main trends that determine ion-electrode interactions in ionic liquids. We compare the interfacial behaviour of Li(+) and K(+) at a charged graphene sheet in a room temperature ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate, and its mixtures with lithium and potassium tetrafluoroborate salts. Our results show that there are dense interfacial solvation structures in these electrolytes that lead to the formation of high free energy barriers for these alkali metal cations between the bulk and direct contact with the negatively charged surface. We show that the stronger solvation of Li(+) in the ionic liquid leads to the formation of significantly higher interfacial free energy barriers for Li(+) than for K(+). The high free energy barriers observed in our simulations can explain the generally high interfacial resistance in electrochemical storage devices that use ionic liquid-based electrolytes. Overcoming these barriers is the rate-limiting step in the interfacial transport of alkali metal ions and, hence, appears to be a major drawback for a generalised application of ionic liquids in electrochemistry. Some plausible strategies for future theoretical and experimental work for tuning them are suggested. PMID:26661060

  19. EMCASS: Expert Motor Carrier Selection System

    SciTech Connect

    Teeters, S.W.

    1991-03-13

    The Expert Motor Carrier Selection System (EMCASS) was designed as a Knowledge-Based System to help in traffic management at Martin Marietta Energy Systems, Inc. (Energy Systems). The primary function of the system is to suggest the optimal motor carrier(s) for a given freight shipment to or from Energy Systems. The system accepts a zip code (destination or origin) from the user, a shipment weight, and other related information in some cases. EMCASS then suggests the best carrier for that shipment, and journals the results. The objective of this project is to distribute the knowledge of the company`s traffic managers, and to emulate their decision processes as closely as possible.

  20. A Compact Liquid Xenon Compton Telescope with High Energy Resolution and Time-of-Flight

    NASA Astrophysics Data System (ADS)

    Oberlack, Uwe; Gomez, R.; Olsen, C.; Shagin, P.; Aprile, E.; Giboni, K.; Plante, G.; Santorelli, R.

    2006-09-01

    Two recent developments have led us to propose a new type of Compton telescope in compact geometry with time-of-flight, for gamma-ray astronomy in the energy regime of 0.2 - 10 MeV. First, the technology of vacuum ultraviolet photosensors for efficient and fast readout of liquid xenon (LXe) scintillation light has improved dramatically over the last few years, and new developments are underway. A LXe Advanced Compton Telescope would consist of two detector arrays of LXe time projection chambers in compact geometry, with time-of-flight (ToF) between detector modules at a resolution of order 100 ps. Second, the previously achieved moderate energy resolution in LXe, a significant draw-back for gamma-ray line spectroscopy, has been found to be largely due to a strong anti-correlation of ionization and scintillation in LXe. Efficient measurement of both charge and light enables us to improve energy resolution greatly. A factor of three improvement over a previous prototype, LXeGRIT, has already been achieved, and the measured underlying physics indicate the possibility of achievng energy resolution below 1% FWHM at 1 MeV. We are vigorously working on improving light and charge readout to realize this potential in a practical detector. We report on the status and prospects of our current research and development program. This work is supported by NASA grant NNG05WC24G.

  1. Zero Energy Communities with Central Solar Plants using Liquid Desiccants and Local Storage: Preprint

    SciTech Connect

    Burch, J.; Woods, J.; Kozubal, E.; Boranian, A.

    2012-08-01

    The zero energy community considered here consists of tens to tens-of-thousands of residences coupled to a central solar plant that produces all the community's electrical and thermal needs. A distribution network carries fluids to meet the heating and cooling loads. Large central solar systems can significantly reduce cost of energy vs. single family systems, and they enable economical seasonal heat storage. However, the thermal distribution system is costly. Conventional district heating/cooling systems use a water/glycol solution to deliver sensible energy. Piping is sized to meet the peak instantaneous load. A new district system introduced here differs in two key ways: (i) it continuously distributes a hot liquid desiccant (LD) solution to LD-based heating and cooling equipment in each home; and (ii) it uses central and local storage of both LD and heat to reduce flow rates to meet average loads. Results for piping sizes in conventional and LD thermal communities show that the LD zero energy community reduces distribution piping diameters meeting heating loads by {approx}5X and meeting cooling loads by {approx}8X for cooling, depending on climate.

  2. The application of liquid air energy storage for large scale long duration solutions to grid balancing

    NASA Astrophysics Data System (ADS)

    Brett, Gareth; Barnett, Matthew

    2014-12-01

    Liquid Air Energy Storage (LAES) provides large scale, long duration energy storage at the point of demand in the 5 MW/20 MWh to 100 MW/1,000 MWh range. LAES combines mature components from the industrial gas and electricity industries assembled in a novel process and is one of the few storage technologies that can be delivered at large scale, with no geographical constraints. The system uses no exotic materials or scarce resources and all major components have a proven lifetime of 25+ years. The system can also integrate low grade waste heat to increase power output. Founded in 2005, Highview Power Storage, is a UK based developer of LAES. The company has taken the concept from academic analysis, through laboratory testing, and in 2011 commissioned the world's first fully integrated system at pilot plant scale (300 kW/2.5 MWh) hosted at SSE's (Scottish & Southern Energy) 80 MW Biomass Plant in Greater London which was partly funded by a Department of Energy and Climate Change (DECC) grant. Highview is now working with commercial customers to deploy multi MW commercial reference plants in the UK and abroad.

  3. Measurement of the Charge and Light Yield of Low Energy Nuclear Recoils in Liquid Xenon at Different Electric Fields

    NASA Astrophysics Data System (ADS)

    Anthony, Matthew; Aprile, Elena; de Perio, Patrick; Goetzke, Luke; Greene, Zach; Lin, Qing; Messina, Marcello; Plante, Guillaume; Rizzo, Alfio; Zhang, Yun

    2016-03-01

    Dual-phase liquid xenon detectors continue to lead in the search for the direct detection of dark matter. Characterization of the response of liquid xenon to low energy (<= 20 keV) nuclear recoils is essential to establish the sensitivity of these detectors to dark matter. The neriX detector at Columbia University is a dual-phase time projection chamber that is optimized for simultaneous measurements of light and charge from these low-energy interactions. A coincidence technique is employed to extract the light and charge yield from nuclear recoils in liquid xenon as a function of energy deposited and applied electric field. In this talk, we will present preliminary results from the light and charge yield measurements. We acknowledge continued support of the XENON Dark Matter program at Columbia University by the National Science Foundation.

  4. Liquid water on Mars - An energy balance climate model for CO2/H2O atmospheres

    NASA Technical Reports Server (NTRS)

    Hoffert, M. I.; Callegari, A. J.; Hsieh, C. T.; Ziegler, W.

    1981-01-01

    A simple climatic model is developed for a Mars atmosphere containing CO2 and sufficient liquid water to account for the observed hydrologic surface features by the existence of a CO2/H2O greenhouse effect. A latitude-resolved climate model originally devised for terrestrial climate studies is applied to Martian conditions, with the difference between absorbed solar flux and emitted long-wave flux to space per unit area attributed to the divergence of the meridional heat flux and the poleward heat flux assumed to equal the atmospheric eddy heat flux. The global mean energy balance is calculated as a function of atmospheric pressure to assess the CO2/H2O greenhouse liquid water hypothesis, and some latitude-resolved cases are examined in detail in order to clarify the role of atmospheric transport and temperature-albedo feedback. It is shown that the combined CO2/H2O greenhouse at plausible early surface pressures may account for climates hot enough to support a hydrological cycle and running water at present-day insolation and visible albedo levels.

  5. Best Available Technology (BAT) guidance for radiological liquid effluents at US Department of Energy Facilities

    SciTech Connect

    Wallo, A. III; Peterson, H.T. Jr. ); Ikenberry, T.A. ); Baker, R.E. )

    1993-01-01

    The US Department of Energy (DOE), in DOE Order 5400.5 (1990), directs operators of DOE facilities to apply the Best Available Technology (BAT) to control radiological liquid effluents from these facilities when specific conditions are present. DOE has published interim guidance to assist facility operators in knowing when a BAT analysis is needed and how such an analysis should be performed and documented. The purpose of the guidance is to provide a uniform basis in determining BAT throughout DOE and to assist in evaluating BAT determinations during programmatic audits. The BAT analysis process involves characterizing the effluent source; identifying and selecting candidate control technologies; evaluating the potential environmental, operational, resource, and economic impacts of the control technologies; developing an evaluation matrix for comparing the technologies; selecting the BAT; and documenting the evaluation process. The BAT analysis process provides a basis for consistent evaluation of liquid effluent releases, yet allows an individual site or facility the flexibility to address site-specific issues or concerns in the most appropriate manner.

  6. Common Carrier Services.

    ERIC Educational Resources Information Center

    Federal Communications Commission, Washington, DC.

    After outlining the Federal Communications Commission's (FCC) responsibility for regulating interstate common carrier communication (non-broadcast communication whose carriers are required by law to furnish service at reasonable charges upon request), this information bulletin reviews the history, technological development, and current…

  7. Two-phase flow bubbly mixing for liquid metal magnetohydrodynamic energy conversion

    NASA Astrophysics Data System (ADS)

    Fabris, G.; Kwack, E.; Harstad, K.; Back, L. H.

    Experiments aimed at improving mixer design and investigating the effects of surfactants on the two-phase mixture in two-phase liquid metal MHD (LMMHD) energy conversion systems are described. In addition to conventional photography, flash X-ray imaging was used as a diagnostic tool. It was demonstrated that a high void fraction (0.8) and low velocity slip ratio (1.2) two-phase homogeneous bubbly mixture can be created. It is expected that such a two-phase mixture can be further expanded in a LMMHD generator while maintaining low velocity slip. In such a way, high generator and overall system efficiency would be achieved, making LMMHD systems competitive for a number of commercial applications.

  8. Two-phase flow bubbly mixing for liquid metal magnetohydrodynamic energy conversion

    NASA Technical Reports Server (NTRS)

    Fabris, G.; Kwack, E.; Harstad, K.; Back, L. H.

    1990-01-01

    Experiments aimed at improving mixer design and investigating the effects of surfactants on the two-phase mixture in two-phase liquid metal MHD (LMMHD) energy conversion systems are described. In addition to conventional photography, flash X-ray imaging was used as a diagnostic tool. It was demonstrated that a high void fraction (0.8) and low velocity slip ratio (1.2) two-phase homogeneous bubbly mixture can be created. It is expected that such a two-phase mixture can be further expanded in a LMMHD generator while maintaining low velocity slip. In such a way, high generator and overall system efficiency would be achieved, making LMMHD systems competitive for a number of commercial applications.

  9. Liquid crystal free energy relaxation by a theoretically informed Monte Carlo method using a finite element quadrature approach.

    PubMed

    Armas-Pérez, Julio C; Hernández-Ortiz, Juan P; de Pablo, Juan J

    2015-12-28

    A theoretically informed Monte Carlo method is proposed for Monte Carlo simulation of liquid crystals on the basis of theoretical representations in terms of coarse-grained free energy functionals. The free energy functional is described in the framework of the Landau-de Gennes formalism. A piecewise finite element discretization is used to approximate the alignment field, thereby providing an excellent geometrical representation of curved interfaces and accurate integration of the free energy. The method is suitable for situations where the free energy functional includes highly non-linear terms, including chirality or high-order deformation modes. The validity of the method is established by comparing the results of Monte Carlo simulations to traditional Ginzburg-Landau minimizations of the free energy using a finite difference scheme, and its usefulness is demonstrated in the context of simulations of chiral liquid crystal droplets with and without nanoparticle inclusions. PMID:26723642

  10. Liquid crystal free energy relaxation by a theoretically informed Monte Carlo method using a finite element quadrature approach

    NASA Astrophysics Data System (ADS)

    Armas-Pérez, Julio C.; Hernández-Ortiz, Juan P.; de Pablo, Juan J.

    2015-12-01

    A theoretically informed Monte Carlo method is proposed for Monte Carlo simulation of liquid crystals on the basis of theoretical representations in terms of coarse-grained free energy functionals. The free energy functional is described in the framework of the Landau-de Gennes formalism. A piecewise finite element discretization is used to approximate the alignment field, thereby providing an excellent geometrical representation of curved interfaces and accurate integration of the free energy. The method is suitable for situations where the free energy functional includes highly non-linear terms, including chirality or high-order deformation modes. The validity of the method is established by comparing the results of Monte Carlo simulations to traditional Ginzburg-Landau minimizations of the free energy using a finite difference scheme, and its usefulness is demonstrated in the context of simulations of chiral liquid crystal droplets with and without nanoparticle inclusions.

  11. A Method for Microscale Combustion of Near Stoichiometric Energy Dense Liquid Fuel Mixtures

    NASA Astrophysics Data System (ADS)

    Tolmachoff, E. D.; Allmon, W. R.; Waits, C. M.

    2013-12-01

    This paper reports on the potential of a heterogeneous/homogeneous (HH) reactor for use as a fuel-flexible heat source, meeting the needs of the next generation of high temperature thermal-to-electric (TEC) portable power converters. In this class of reactor, low activation energy catalytic reactions provide a means to stabilize high activation energy homogeneous reactions. Diffusion limited surface reactions play a critical role in HH reactor operation. Surface conversion must be sufficiently fast to generate the high temperatures (~1000 K) necessary to initiate gas phase reactions. Therefore, fuel diffusivity and the reactor dimension are important parameters in governing HH reactor operation. We examine the performance of an HH reactor fuelled by propane and n-dodecane, representing two extremes of liquid hydrocarbon diffusivity, as a function of confining reactor dimension. Unburned fuel/air mixtures are close to stoichiometric, which is an important factor in minimizing the amount of excess air and, therefore, balance of plant energy costs. At moderate levels of confinement, the reactor is capable producing high, uniform temperatures for both fuels.

  12. Development of a model for baffle energy dissipation in liquid fueled rocket engines

    NASA Astrophysics Data System (ADS)

    Miller, Nathan A.

    In this thesis the energy dissipation from a combined hub and blade baffle structure in a combustion chamber of a liquid-fueled rocket engine is modeled and computed. An analytical model of the flow stabilization due to the effect of combined radial and hub blades was developed. The rate of energy dissipation of the baffle blades was computed using a corner-flow model that included unsteady flow separation and turbulence effects. For the inviscid portion of the flow field, a solution methodology was formulated using an eigenfunction expansion and a velocity potential matching technique. Parameters such as local velocity, elemental path length, effective viscosity, and local energy dissipation rate were computed as a function of the local angle alpha for a representative baffle blade, and compared to results predicted by the Baer-Mitchell blade dissipation model. The sensitivity of the model to the overall engine acoustic oscillation mode, blade length, and thickness was also computed and compared to previous results. Additional studies were performed to determine the sensitivity to input parameters such as the dimensionless turbulence coefficient, the location of the potential difference in the generation of the dividing streamline, the number of baffle blades and the size of the central hub. Stability computations of a test engine indicated that when the baffle length is increased, the baffles provide increased stabilization effects. The model predicts greatest dissipation for radial modes with a hub radius at approximately half the chamber's radius.

  13. Dispersion of submicron Ni particles into liquid gallium

    NASA Astrophysics Data System (ADS)

    Cao, L. F.; Park, H. S.; Dodbiba, G.; Fujita, T.

    2008-06-01

    In this paper a liquid gallium with a low melting temperature and good thermal conductivity was used as a carrier to develop a new magnetorheological (MR) fluid that can be employed in energy convection devices. Submicron nickel particles, coated with silica, were chosen to be dispersed in the liquid gallium. The silica coating was used to improve the dispersion and prepare the composite particles with a density similar to that of the carrier liquid, i.e., liquid gallium. The supercooling phenomenon of liquid gallium was analyzed to better understand the dispersion of particles. The magnetization behaviours of both the silica-coated nickel particles and the synthesized MR fluids were measured. The results showed that the silica-coated nickel particles exhibited a shell-type structure, and the composite particle with a density same as the one of liquid gallium can be obtained by controlling the thickness of the coating layer to approximately 22 nm. The submicron nickel particles with the help of silica coating can be easily dispersed into liquid gallium. It was found that the supercooling of liquid gallium varied from 13.5 K to 19.3 K depending on the thickness of the coating layer of the dispersed particles. The saturation magnetization of the composite particles was reduced due to the occurrence of a non-magnetic silica layer. Figs 5, Refs 14.

  14. Plasmon-induced hot carriers in metallic nanoparticles.

    PubMed

    Manjavacas, Alejandro; Liu, Jun G; Kulkarni, Vikram; Nordlander, Peter

    2014-08-26

    Plasmon-induced hot carrier formation is attracting an increasing research interest due to its potential for applications in photocatalysis, photodetection and solar energy harvesting. However, despite very significant experimental effort, a comprehensive theoretical description of the hot carrier generation process is still missing. In this work we develop a theoretical model for the plasmon-induced hot carrier process and apply it to spherical silver nanoparticles and nanoshells. In this model, the conduction electrons of the metal are described as free particles in a finite spherical potential well, and the plasmon-induced hot carrier production is calculated using Fermi’s golden rule. We show that the inclusion of many-body interactions has only a minor influence on the results. Using the model we calculate the rate of hot carrier generation, finding that it closely follows the spectral profile of the plasmon. Our analysis reveals that particle size and hot carrier lifetime play a central role in determining both the production rate and the energy distribution of the hot carriers. Specifically, larger nanoparticle sizes and shorter lifetimes result in higher carrier production rates but smaller energies, and vice versa. We characterize the efficiency of the hot carrier generation process by introducing a figure of merit that measures the number of high energy carriers generated per plasmon. Furthermore, we analyze the spatial distribution and directionality of these excitations. The results presented here contribute to the basic understanding of plasmon-induced hot carrier generation and provide insight for optimization of the process. PMID:24960573

  15. Effective Charge Carrier Utilization in Photocatalytic Conversions.

    PubMed

    Zhang, Peng; Wang, Tuo; Chang, Xiaoxia; Gong, Jinlong

    2016-05-17

    Continuous efforts have been devoted to searching for sustainable energy resources to alleviate the upcoming energy crises. Among various types of new energy resources, solar energy has been considered as one of the most promising choices, since it is clean, sustainable, and safe. Moreover, solar energy is the most abundant renewable energy, with a total power of 173 000 terawatts striking Earth continuously. Conversion of solar energy into chemical energy, which could potentially provide continuous and flexible energy supplies, has been investigated extensively. However, the conversion efficiency is still relatively low since complicated physical, electrical, and chemical processes are involved. Therefore, carefully designed photocatalysts with a wide absorption range of solar illumination, a high conductivity for charge carriers, a small number of recombination centers, and fast surface reaction kinetics are required to achieve a high activity. This Account describes our recent efforts to enhance the utilization of charge carriers for semiconductor photocatalysts toward efficient solar-to-chemical energy conversion. During photocatalytic reactions, photogenerated electrons and holes are involved in complex processes to convert solar energy into chemical energy. The initial step is the generation of charge carriers in semiconductor photocatalysts, which could be enhanced by extending the light absorption range. Integration of plasmonic materials and introduction of self-dopants have been proved to be effective methods to improve the light absorption ability of photocatalysts to produce larger amounts of photogenerated charge carriers. Subsequently, the photogenerated electrons and holes migrate to the surface. Therefore, acceleration of the transport process can result in enhanced solar energy conversion efficiency. Different strategies such as morphology control and conductivity improvement have been demonstrated to achieve this goal. Fine-tuning of the

  16. Nanotube liquid crystal elastomers: photomechanical response and flexible energy conversion of layered polymer composites

    NASA Astrophysics Data System (ADS)

    Fan, Xiaoming; King, Benjamin C.; Loomis, James; Campo, Eva M.; Hegseth, John; Cohn, Robert W.; Terentjev, Eugene; Panchapakesan, Balaji

    2014-09-01

    Elastomeric composites based on nanotube liquid crystals (LCs) that preserve the internal orientation of nanotubes could lead to anisotropic physical properties and flexible energy conversion. Using a simple vacuum filtration technique of fabricating nanotube LC films and utilizing a transfer process to poly (dimethyl) siloxane wherein the LC arrangement is preserved, here we demonstrate unique and reversible photomechanical response of this layered composite to excitation by near infra-red (NIR) light at ultra-low nanotube mass fractions. On excitation by NIR photons, with application of small or large pre-strains, significant expansion or contraction of the sample occurs, respectively, that is continuously reversible and three orders of magnitude larger than in pristine polymer. Schlieren textures were noted in these LC composites confirming long range macroscopic nematic order of nanotubes within the composites. Order parameters of LC films ranged from Soptical = 0.51-0.58 from dichroic measurements. Film concentrations, elastic modulus and photomechanical stress were all seen to be related to the nematic order parameter. For the same nanotube concentration, the photomechanical stress was almost three times larger for the self-assembled LC nanotube actuator compared to actuator based on randomly oriented carbon nanotubes. Investigation into the kinetics of photomechanical actuation showed variation in stretching exponent β with pre-strains, concentration and orientation of nanotubes. Maximum photomechanical stress of ˜0.5 MPa W-1 and energy conversion of ˜0.0045% was achieved for these layered composites. The combination of properties, namely, optical anisotropy, reversible mechanical response to NIR excitation and flexible energy conversion all in one system accompanied with low cost makes nanotube LC elastomers important for soft photochromic actuation, energy conversion and photo-origami applications.

  17. Simultaneous Determination of Caffeine and Vitamin B6 in Energy Drinks by High-Performance Liquid Chromatography (HPLC)

    ERIC Educational Resources Information Center

    Leacock, Rachel E.; Stankus, John J.; Davis, Julian M.

    2011-01-01

    A high-performance liquid chromatography experiment to determine the concentration of caffeine and vitamin B6 in sports energy drinks has been developed. This laboratory activity, which is appropriate for an upper-level instrumental analysis course, illustrates the standard addition method and simultaneous determination of two species. (Contains 1…

  18. Pulse-shape discrimination and energy resolution of a liquid-argon scintillator with xenon doping

    NASA Astrophysics Data System (ADS)

    Wahl, C. G.; Bernard, E. P.; Lippincott, W. H.; Nikkel, J. A.; Shin, Y.; McKinsey, D. N.

    2014-06-01

    Liquid-argon scintillation detectors are used in fundamental physics experiments and are being considered for security applications. Previous studies have suggested that the addition of small amounts of xenon dopant improves performance in light or signal yield, energy resolution, and particle discrimination. In this study, we investigate the detector response for xenon dopant concentrations from 9 ± 5 ppm to 1100 ± 500 ppm xenon (by weight) in 6 steps. The 3.14-liter detector uses tetraphenyl butadiene (TPB) wavelength shifter with dual photomultiplier tubes and is operated in single-phase mode. Gamma-ray-interaction signal yield of 4.0 ± 0.1 photoelectrons/keV improved to 5.0 ± 0.1 photoelectrons/keV with dopant. Energy resolution at 662 keV improved from (4.4 ± 0.2)% (σ) to (3.5 ± 0.2)% (σ) with dopant. Pulse-shape discrimination performance degraded greatly at the first addition of dopant, slightly improved with additional additions, then rapidly improved near the end of our dopant range, with performance becoming slightly better than pure argon at the highest tested dopant concentration. Some evidence of reduced neutron scintillation efficiency with increasing dopant concentration was observed. Finally, the waveform shape outside the TPB region is discussed, suggesting that the contribution to the waveform from xenon-produced light is primarily in the last portion of the slow component.

  19. Non-Faradaic Energy Storage by Room Temperature Ionic Liquids in Nanoporous Electrodes.

    PubMed

    Vatamanu, Jenel; Vatamanu, Mihaela; Bedrov, Dmitry

    2015-06-23

    The enhancement of non-Faradaic charge and energy density stored by ionic electrolytes in nanostructured electrodes is an intriguing issue of great practical importance for energy storage in electric double layer capacitors. On the basis of extensive molecular dynamics simulations of various carbon-based nanoporous electrodes and room temperature ionic liquid (RTIL) electrolytes, we identify atomistic mechanisms and correlations between electrode/electrolyte structures that lead to capacitance enhancement. In the symmetric electrode setup with nanopores having atomically smooth walls, most RTILs showed up to 50% capacitance increase compared to infinitely wide pore. Extensive simulations using asymmetric electrodes and pores with atomically rough surfaces demonstrated that tuning of electrode nanostructure could lead to further substantial capacitance enhancement. Therefore, the capacitance in nanoporous electrodes can be increased due to a combination of two effects: (i) the screening of ionic interactions by nanopore walls upon electrolyte nanoconfinement, and (ii) the optimization of nanopore structure (volume, surface roughness) to take into account the asymmetry between cation and anion chemical structures. PMID:26038979

  20. Molecular Dynamics Study of Freezing Point and Solid-Liquid Interfacial Free Energy of Stockmayer Fluids

    SciTech Connect

    Wang, J.; Apte, Pankaj; Morris, James R; Zeng, X.C.

    2013-01-01

    Freezing temperatures of Stockmayer fluids with different dipolar strength at zero pressure are estimated and computed using three independent molecular-dynamics (MD) simulation methods, namely, the superheating-undercooling method, the constant-pressure and constant-temperature (NPT) two phase coexistence method, and the constant-pressure and constant-enthalpy (NPH) coexistence method. The best estimate of the freezing temperature (in reduced unit) for the Stockmayer (SM) fluid with a reduced dipole moment is 0.656 0.001, 0.726 0.002 and 0.835 0.005, respectively. The freezing temperature increases with the dipolar strength. The solid-liquid interfacial free energies of the (111), (110) and (100) interface are calculated for the first time using two independent methods, namely, the cleaving-wall method and the interfacial fluctuation method. Both methods predict that the interfacial free energy increases with the dipole moment. Although the interfacial fluctuation method suggests a weaker interfacial anisotropy, particularly for strongly dipolar SM fluids, both methods predicted the same trend of interfacial anisotropy, that is, .

  1. The reflection of low energy phonons at the free surface of liquid4He. II. Experiment

    NASA Astrophysics Data System (ADS)

    Baddar, H.; Edwards, D. O.

    1996-09-01

    Using a heater and bolometer as source and detector, the reflection of a pulsed beam of phonons at the free surface of liquid4He at ˜ 0.05 K has been measured for angles of incidence between 30 ° and 80 °. The energy distribution of the incident beam was obtained from the theory of phonon decay in the accompanying paper (I). The average incident phonon energy was ˜ 0.3 K, corresponding to an effective beam temperature of about 0.1 K. Both heater and bolometer were made from graphite resistor board with a layer of poly aniline fibers to increase the absorptivity for rotons. The angular distribution of the phonons from the heater is quite broad, approximately (cosn π+cosm θ)/2 with n ≈ 0.65 and m ≈ 3.4. However, the receiver response has a broad component with n ≈ 2.2 and an extraordinarily narrow one with m ≈ 106. In agreement with the theory in I, the reflection appears to be specular within the accuracy of the experiment. The reflection coefficient is unity within the experimental error; the weighted mean value is 1.001±0.025. During the experiment, the free surface became contaminated with ˜ 0.034 of a monolayer of3He, but no effect from the3He impurity was observed.

  2. Ultrafast energy transfer to liquid water by sub-picosecond high-intensity terahertz pulses: an ab initio molecular dynamics study.

    PubMed

    Mishra, Pankaj Kr; Vendrell, Oriol; Santra, Robin

    2013-12-16

    Sub-picosecond heating of bulk water is accomplished by ultrashort and intense THz pulses which are able to transfer a large amount of energy to the liquid. The energy transferred corresponds to a temperature jump of about 600 K. Liquid water becomes a structureless and hot gas-like system still at the density of the liquid, in which the hydrogen-bonding structure has been washed out. PMID:24155137

  3. Liquid Scoping Study for Tritium-Lean, Fast Ignition Inertial Fusion Energy Power Plants

    SciTech Connect

    Schmitt, R C; Latkowski, J F; Durbin, S G; Meier, W R; Reyes, S

    2001-08-14

    In a thick-liquid protected chamber design, such as HYLIFE-II, a molten-salt is used to attenuate neutrons and protect the chamber structures from radiation damage. The molten-salt absorbs some of the material and energy given off by the target explosion. In the case of a fast ignition inertial fusion system, advanced targets have been proposed that may be Self-sufficient in the tritium breeding (i.e., the amount of tritium bred in target exceeds the amount burned). These ''tritium-lean'' targets contain approximately 0.5% tritium and 99.5% deuterium, but require a large pr of 10-20 g/cm{sup 2}. Although most of the yield is provided by D-T reactions, the majority of fusion reactions are D-D, which produces a net surplus of tritium. This aspect allows for greater freedom when selecting a liquid for the protective blanket (lithium-bearing compounds are not required). This study assesses characteristics of many single, binary, and ternary molten-salts. Using the NIST Properties of Molten Salts Database, approximately 4300 molten-salts were included in the study [1]. As an initial screening, salts were evaluated for their safety and environmental (S&E) characteristics, which included an assessment of waste disposal rating, contact dose, and radioactive afterheat. Salts that passed the S&E criteria were then evaluated for neutron shielding ability and pumping power. The pumping power was calculated using three components: velocity head losses, frictional losses, and lift. This assessment left us with 57 molten-salts to recommend for further analysis. Many of these molten-salts contain elements such as sodium, lithium, beryllium, boron, fluorine, and oxygen. Recommendations for further analysis are also made.

  4. Where are ionic liquid strategies most suited in the pursuit of chemicals and energy from lignocellulosic biomass?

    PubMed

    Sun, Ning; Rodríguez, Héctor; Rahman, Mustafizur; Rogers, Robin D

    2011-02-01

    Certain ionic liquids have been shown to dissolve cellulose, other biopolymers, and even raw biomass under relatively mild conditions. This particular ability of some ionic liquids, accompanied by a series of concurrent advantages, enables the development of improved processing strategies for the manufacturing of a plethora of biopolymer-based advanced materials. The more recent discoveries of dissolution of lignocellulosic materials (e.g., wood) in ionic liquids, with at least partial separation of the major constituent biopolymers, suggest further paths towards the achievement of a truly sustainable chemical and energy economy based on the concept of a biorefinery which provides chemicals, materials, and energy. Nonetheless, questions remain about the use of ionic liquids and the advisability of introducing any new process which utilizes bulk synthetic chemicals which have to be made, disposed of, and prevented from entering the environment. In this article, we discuss our own journey from the discovery of the dissolution of cellulose in ionic liquids to the cusp of an enabling technology for a true biorefinery and consider some of the key questions which remain. PMID:21170465

  5. Hydrodynamics and energy consumption studies in a three-phase liquid circulating three-phase fluid bed contactor

    SciTech Connect

    Rusumdar, Ahmad J; Abuthalib, A.; Mohan, Vaka Murali; Srinivasa Kumar, C.; Sujatha, V.; Rajendra Prasad, P.

    2009-07-15

    The hydrodynamics and energy consumption have been studied in a cold flow, bubbling and turbulent, pressurized gas-liquid-solid three-phase fluidized bed (0.15 m ID x 1 m height) with concurrent gas-liquid up flow is proposed with the intention of increasing the gas hold up. The hydrodynamic behaviour is described and characterised by some specific gas and liquid velocities. Particles are easily fluidized and can be uniformly distributed over the whole height of the column. The effect of parameters like liquid flow rate, gas flow rate, particle loading, particle size, and solid density on gas hold up and effect of gas flow rate, solid density and particle size on solid hold up, energy consumption and minimum fluidization velocity has been studied. At the elevated pressures a superior method for better prediction of minimum fluidization velocity and terminal settling velocities has been adopted. The results have been interpreted with Bernoulli's theorem and Richardson-Zaki equation. Based on the assumption of the gas and liquid as a pretend fluid, a simplification has been made to predict the particle terminal settling velocities. The Richardson-Zaki parameter n' was compared with Renzo's results. A correlation has been proposed with the experimental results for the three-phase fluidization. (author)

  6. Extracting hot carriers from photoexcited semiconductor nanocrystals

    SciTech Connect

    Zhu, Xiaoyang

    2014-12-10

    This research program addresses a fundamental question related to the use of nanomaterials in solar energy -- namely, whether semiconductor nanocrystals (NCs) can help surpass the efficiency limits, the so-called “Shockley-Queisser” limit, in conventional solar cells. In these cells, absorption of photons with energies above the semiconductor bandgap generates “hot” charge carriers that quickly “cool” to the band edges before they can be utilized to do work; this sets the solar cell efficiency at a limit of ~31%. If instead, all of the energy of the hot carriers could be captured, solar-to-electric power conversion efficiencies could be increased, theoretically, to as high as 66%. A potential route to capture this energy is to utilize semiconductor nanocrystals. In these materials, the quasi-continuous conduction and valence bands of the bulk semiconductor become discretized due to confinement of the charge carriers. Consequently, the energy spacing between the electronic levels can be much larger than the highest phonon frequency of the lattice, creating a “phonon bottleneck” wherein hot-carrier relaxation is possible via slower multiphonon emission. For example, hot-electron lifetimes as long as ~1 ns have been observed in NCs grown by molecular beam epitaxy. In colloidal NCs, long lifetimes have been demonstrated through careful design of the nanocrystal interfaces. Due to their ability to slow electronic relaxation, semiconductor NCs can in principle enable extraction of hot carriers before they cool to the band edges, leading to more efficient solar cells.

  7. The mobility of negative charges in liquid hydrogen

    NASA Astrophysics Data System (ADS)

    Lerner, P. B.; Sokolov, I. M.

    1994-06-01

    There is a great difference in behavior of e- in liquid hydrogen and helium despite the fact that the adopted theories of the mobility are quite similar. Recently, Levchenko and Mezhov-Deglin (Journal of Low Temperature Physics, 89, 457 (1992)) reported large discrepancies of the mobility of the electrons in liquid hydrogen from estimates based on the theory that the electrons are trapped in bubbles forming atomlike structures (“bubblonium”). They properly suggested that these deviations are related to the existence in liquid hydrogen of another, metastable type of negative charge carrier. The subject of the current paper is the physical explanation of the existence of two types of carriers in liquid hydrogen. We attribute the second type of carriers to the cluster ion H - ( H 2 ) x , which is created by the formation of solid hydrogen around a bound state of a hydride ion. We provide estimates for the radius and the kinetics of degradation of the “snowball” formed around the H - ion on the basis of energy diagrams for a hydride ion submerged in liquid hydrogen.

  8. Photoinduced hydrogen evolution using bipyridinium salts as electron carrier

    SciTech Connect

    Okura, I.; Kaji, N.; Aono, S.; Kita, T.; Yamada, A.

    1985-02-13

    Photochemical redox systems have been proposed for solar energy utilization. The systems including a photosensitizer, an electron donor, and an electron carrier, have been able to evolve hydrogen from water when a suitable catalyst can be applied. The electron carrier employed almost exclusively in these studies is methylviologen except for a few cases. It is desirable to explore other suitable electron carriers. In this paper some bipyridinium salts are described which are more suitable electron carriers than methylviologen. To clarify why hydrogen evolution rates are so high when some bipyridinium salts are used as electron carriers, kinetic studies were carried out by laser flash photolysis. 13 references, 4 figures, 1 table.

  9. Role of energy exchange in vibrational dephasing processes in liquids and solids

    SciTech Connect

    Marks, S.

    1981-08-01

    Three theories which claim relevance to the dephasing of molecular vibrations in condensed phase matter are presented. All of these theories predict (in certain limiting cases) that the widths and shifts of molecular vibrations will obey an Arrhenius temperature dependence. The basic tenets of the theories are detailed so that the differences between them may be used in an experiment to distinguish between them. One model, based on intermolecular energy exchange of low-frequency modes, results in dephasing the high-frequency modes when anharmonic coupling is present. A computer analysis of temperature dependent experimental lineshapes can result in the extraction of various parameters such as the anharmonic shifts and the exchange rates. It is shown that, in order to properly assess the relative validity of the three models, other evidence must be obtained such as the spectral parameters of the low-frequency modes, the combination bands, and the isotopic dilution behavior. This evidence is presented for d/sub 14/-durene (perdeutero-1,2,4,5-tetramethylbenzene) and compared to previous data obtained on pure h/sub 14/-durene. An extension of the (HSC) intermolecular energy exchange model which allows for the possibility of partial delocalization of the low-frequency modes gives an adequate description of the experimental evidence. Isotopic dilution experiments, in particular, have resulted in a detailed picture of the energy transfer dynamics of the low-frequency modes. A section in which some spontaneous Raman spectra support a model of inhomogeneous broadening in liquids based on results of picosecond stimulated Raman spectroscopy is presented. The model is that a distribution of environmental sites is created by a distribution in the local density and thus creates inhomogeneous broadening.

  10. The uncertainty analysis on energy scale due to the variation of W value for liquid xenon dark matter detector

    NASA Astrophysics Data System (ADS)

    Wang, Lu; Mei, Dongming; Cubed Collaboration

    2016-03-01

    The average energy expended per electron-ion pair, W value, is critical in understanding a liquid xenon detector energy response to low energy recoils. The reduction of scintillation and ionization yield for electronic recoils and nuclear recoils are explained using the scintillation quenching mechanism due to the variation of the average energy expended per electron hole pair, W value, which includes the energy lost to scintillation and phonon generation. We show the theoretical calculation of scintillation efficiency with W value in comparison with experimental data. The impact of variation of W value on the analysis of energy scale is discussed in detail. We conclude that the W value determined with experimental data depends on recoil energy and particle type. This work is supported by NSF in part by the NSF OIA 1434142, DOE Grant DE-FG02-10ER46709, and the State of South Dakota.

  11. Determination of liquid's molecular interference function based on X-ray diffraction and dual-energy CT in security screening.

    PubMed

    Zhang, Li; YangDai, Tianyi

    2016-08-01

    A method for deriving the molecular interference function (MIF) of an unknown liquid for security screening is presented. Based on the effective atomic number reconstructed from dual-energy computed tomography (CT), equivalent molecular formula of the liquid is estimated. After a series of optimizations, the MIF and a new effective atomic number are finally obtained from the X-ray diffraction (XRD) profile. The proposed method generates more accurate results with less sensitivity to the noise and data deficiency of the XRD profile. PMID:27239986

  12. Determining charge carrier mobility in Schottky contacted single-carrier organic devices by impedance spectroscopy

    NASA Astrophysics Data System (ADS)

    Tang, Ying; Peng, Yingquan; Sun, Lei; Wei, Yi; Xu, Sunan

    2015-10-01

    Impedance spectroscopy (IS) is one of the most important methods for analyzing transport properties of semiconducting thin films. At present carrier mobility can be determined by IS methods only for Ohmic contacted single-carrier devices, which hinders the use of the IS method for determining the carrier mobility of thin films with high-lying lowest unoccupied molecular orbits or low-lying highest occupied molecular orbits. Based on the theory of space charge limited current conduction and thermionic emission at metal-organic interface, we developed a numerical IS model for single-carrier organic devices with Schottky injection contact. With the help of this model, a concise empirical formula is obtained from which the carrier mobility can be determined from the characteristic frequency of the negative differential susceptance and the Schottky energy barrier height at the injection contact.

  13. Energy Conversion Alternatives Study (ECAS), Westinghouse phase 1. Volume 10: Liquid-metal MHD systems. [energy conversion efficiency of electric power plants using liquid metal magnetohydrodynamics

    NASA Technical Reports Server (NTRS)

    Holman, R. R.; Lippert, T. E.

    1976-01-01

    Electric Power Plant costs and efficiencies are presented for two basic liquid-metal cycles corresponding to 922 and 1089 K (1200 and 1500 F) for a commercial applications using direct coal firing. Sixteen plant designs are considered for which major component equipment were sized and costed. The design basis for each major component is discussed. Also described is the overall systems computer model that was developed to analyze the thermodynamics of the various cycle configurations that were considered.

  14. An assessment of energy and environmental issues related to the use of gas-to-liquid fuels in transportation

    SciTech Connect

    Greene, D.L.

    1999-11-01

    Recent technological advances in processes for converting natural gas into liquid fuels, combined with a growing need for cleaner, low-sulfur distillate fuel to mitigate the environmental impacts of diesel engines have raised the possibility of a substantial global gas-to-liquids (G-T-L) industry. This report examines the implications of G-T-L supply for U.S. energy security and the environment. It appears that a G-T-L industry would increase competitiveness in world liquid fuels markets, even if OPEC states are major producers of G-T-L's. Cleaner G-T-L distillates would help reduce air pollution from diesel engines. Implications for greenhouse gas (GHG) emissions could be positive or negative, depending on the sources of natural gas, their alternative uses, and the degree of sequestration that can be achieved for CO{sub 2} emissions produced during the conversion process.

  15. An Assessment of Energy and Environmental Issues Related to the Use of Gas-to-Liquid Fuels in Transportation

    SciTech Connect

    Greene, D.L.

    1999-11-01

    Recent technological advances in processes for converting natural gas into liquid fuels, combined with a growing need for cleaner, low-sulfur distillate fuel to mitigate the environmental impacts of diesel engines have raised the possibility of a substantial global gas-to-liquids (G-T-L) industry. This report examines the implications of G-T-L supply for U.S. energy security and the environment. It appears that a G-T-L industry would increase competitiveness in world liquid fuels markets, even if OPEC states are major producers of G-T-L's. Cleaner G-T-L distillates would help reduce air pollution from diesel engines. Implications for greenhouse gas (GHG) emissions could be positive or negative, depending on the sources of natural gas, their alternative uses, and the degree of sequestration that can be achieved for CO2 emissions produced during the conversion process.

  16. Free energy of solvation of carbon nanotubes in pyridinium-based ionic liquids.

    PubMed

    Chaban, Vitaly V; Fileti, Eudes Eterno

    2016-07-27

    Numerous prospective applications require the availability of individual carbon nanotubes (CNTs). Pristine CNTs, strongly hydrophobic in nature, are known to be either totally insoluble or poorly dispersible. While it is unlikely to be possible to prepare a real solution of CNTs in any solvent, the ability of certain solvents to maintain dispersions of CNTs for macroscopic times constitutes great research interest. In the present work, we characterize two pyridinium-based ionic liquids (ILs), N-butylpyridinium chloride [BPY][Cl] and N-butylpyridinium bis(trifluoromethanesulfonyl)imide [BPY][TFSI], with respect to their potential to solvate CNTs of different diameters, from the CNT (10,10) to the CNT (25,25). Using a universal methodology, we found that both ILs exhibit essentially the same solvation performance. Solvation of CNTs is strongly prohibited entropically, whereas the energy penalty increases monotonically with the CNT diameter. Weak van der Waals interactions, which guide enthalpy alteration upon the CNT solvation, are unable to compensate for the large entropic penalty from the destruction of the IL-IL electrostatic interactions. The structure of ILs inside and outside CNTs is also discussed. The reported results are necessary for gaining a fundamental understanding of the CNT solvation problems, thereby inspiring the search for more suitable solvents. PMID:27400869

  17. Influences of surface and flexoelectric polarization on the effective anchoring energy in nematic liquid crystal

    NASA Astrophysics Data System (ADS)

    Guan, Rong-Hua; Ye, Wen-Jiang; Xing, Hong-Yu

    2015-10-01

    The physical effects on surface and flexoelectric polarization in a weak anchoring nematic liquid crystal cell are investigated systematically. We derive the analytic expressions of two effective anchoring energies for lower and upper substrates respectively as well as their effective anchoring strengths and corresponding tilt angles of effective easy direction. All of these quantities are relevant to the magnitudes of both two polarizations and the applied voltage U. Based on these expressions, the variations of effective anchoring strength and the tilt angle with the applied voltage are calculated for the fixed values of two polarizations. For an original weak anchoring hybrid aligned nematic cell, it may be equivalent to a planar cell for a small value of U and has a threshold voltage. The variation of reduced threshold voltage with reduced surface polarization strength is also calculated. The role of surface polarization is important without the adsorptive ions considered. Project supported by the National Natural Science Foundation of China (Grant Nos. 11274088, 11374087, and11304074), the Natural Science Foundation of Hebei Province, China (Grant No. A2014202123), the Research Project of Hebei Provincial Education Department, China (Grant No. QN2014130), and the Key Subject Construction Project of Hebei Provincial University, China.

  18. Ultrafast carrier dynamics in polycrystalline bismuth telluride nanofilm

    SciTech Connect

    Jia, Lin; Ma, Weigang; Zhang, Xing

    2014-06-16

    In this study, the dynamics of energy carriers in polycrystalline bismuth telluride nanofilm are investigated by the ultrafast pump-probe method. The energy relaxation processes are quantitatively analyzed by using the numerical fitting models. The extracted hot carrier relaxation times of photon excitation, thermalization, and diffusion are around sub-picosecond. The initial reflectivity recovery is found to be dominantly determined by the carrier diffusion, electron-phonon coupling, and photo-generated carriers trapping processes. High-frequency and low-frequency oscillations are both observed and attributed to coherent optical phonons and coherent acoustic phonons, respectively.

  19. Automatic carrier acquisition system

    NASA Technical Reports Server (NTRS)

    Bunce, R. C. (Inventor)

    1973-01-01

    An automatic carrier acquisition system for a phase locked loop (PLL) receiver is disclosed. It includes a local oscillator, which sweeps the receiver to tune across the carrier frequency uncertainty range until the carrier crosses the receiver IF reference. Such crossing is detected by an automatic acquisition detector. It receives the IF signal from the receiver as well as the IF reference. It includes a pair of multipliers which multiply the IF signal with the IF reference in phase and in quadrature. The outputs of the multipliers are filtered through bandpass filters and power detected. The output of the power detector has a signal dc component which is optimized with respect to the noise dc level by the selection of the time constants of the filters as a function of the sweep rate of the local oscillator.

  20. Binding in pair potentials of liquid simple metals from nonlocality in electronic kinetic energy

    NASA Technical Reports Server (NTRS)

    Perrot, F.; March, N. H.

    1990-01-01

    The paper presents an explicit expression for the pair potential in liquid simple metals from low-order density-gradient theory when the superposition of single-center displaced charges is employed. Numerical results are presented for the gradient expansion pair interaction in liquid Na and Be. The low-order density-gradient equation for the pair potential is presented.

  1. The physics of coal liquid slurry atomization. Final report to Department of Energy - PETC

    SciTech Connect

    Chigier, N.; Mansour, A.

    1995-10-01

    The stability of turbulent columns of liquid injected into a quiescent environment was studied. Laser Doppler Anemometry measurements of the flow patterns and turbulence characteristics in free liquid jets were made. Turbulence decay along Newtonian jets was investigated along with the effects of turbulence on the resulting droplet size distributions after breakup. The rate of decay of turbulence properties along the jet were investigated. Disintegration of liquid jets injected into a high-velocity gas stream has also been studied. Newtonian and non-Newtonian liquids were studied with particular emphasis on the non-Newtonian rheological characteristics. Determination was made of the extent that the addition of high molecular weight polymer to liquids change the breakup process. Shear thinning, extension thinning and extension thickening fluids were investigated. Shear viscosities were measured over five decades of shear rates. The contraction flow technique was also used for measurement of the extensional viscosity of non-Newtonian liquids. The die-swell technique was also used to determine the first normal stress difference. The near field produced by a co-axial airblast atomizer was investigated using the phase Doppler particle analyzer. Whether or not the classical wave mechanism and empirical models reported for airblast atomization of low viscosity liquid are applicable to airblast atomization of viscous non-Newtonian liquids was determined. The theoretical basis of several models which give the best fit to the experimental data for airblast atomization of non-Newtonian liquids was also discussed. The accuracy of the wave mechanism-based models in predicting droplets sizes after breakup of viscous non-Newtonian liquids using an airblast atomizer has also been demonstrated.

  2. Triangular tessellation scheme for the adsorption free energy at the liquid-liquid interface: Towards nonconvex patterned colloids.

    PubMed

    de Graaf, Joost; Dijkstra, Marjolein; van Roij, René

    2009-11-01

    We present a numerical technique, namely, triangular tessellation, to calculate the free energy associated with the adsorption of a colloidal particle at a flat interface. The theory and numerical scheme presented here are sufficiently general to handle nonconvex patchy colloids with arbitrary surface patterns characterized by a wetting angle, e.g., amphiphilicity. We ignore interfacial deformation due to capillary, electrostatic, or gravitational forces, but the method can be extended to take such effects into account. It is verified that the numerical method presented is accurate and sufficiently stable to be applied to more general situations than presented in this paper. The merits of the tessellation method prove to outweigh those of traditionally used semianalytic approaches, especially when it comes to generality and applicability. PMID:20364983

  3. Carrier heating and negative photoconductivity in graphene

    SciTech Connect

    Heyman, J. N.; Stein, J. D.; Kaminski, Z. S.; Banman, A. R.; Massari, A. M.; Robinson, J. T.

    2015-01-07

    We investigated negative photoconductivity in graphene using ultrafast terahertz techniques. Infrared transmission was used to determine the Fermi energy, carrier density, and mobility of p-type chemical vapor deposition graphene samples. Time-resolved terahertz photoconductivity measurements using a tunable mid-infrared pump probed these samples at photon energies between 0.35 eV and 1.55 eV, approximately one-half to three times the Fermi energy of the samples. Although interband optical transitions in graphene are blocked for pump photon energies less than twice the Fermi energy, we observe negative photoconductivity at all pump photon energies investigated, indicating that interband excitation is not required to observe this effect. Our results are consistent with a thermalized free-carrier population that cools by electron-phonon scattering, but are inconsistent with models of negative photoconductivity based on population inversion.

  4. Anomalous independence of interface superconductivity from carrier density.

    PubMed

    Wu, J; Pelleg, O; Logvenov, G; Bollinger, A T; Sun, Y-J; Boebinger, G S; Vanević, M; Radović, Z; Božović, I

    2013-10-01

    The recent discovery of superconductivity at the interface of two non-superconducting materials has received much attention. In cuprate bilayers, the critical temperature (Tc) can be significantly enhanced compared with single-phase samples. Several explanations have been proposed, invoking Sr interdiffusion, accumulation and depletion of mobile charge carriers, elongation of the copper-to-apical-oxygen bond length, or a beneficial crosstalk between a material with a high pairing energy and another with a large phase stiffness. From each of these models, one would predict Tc to depend strongly on the carrier density in the constituent materials. Here, we study combinatorial libraries of La(2-x)Sr(x)CuO4-La2CuO4 bilayer samples--an unprecedentedly large set of more than 800 different compositions. The doping level x spans a wide range, 0.15 < x < 0.47, and the measured Hall coefficient varies by one order of magnitude. Nevertheless, across the entire sample set, Tc stays essentially constant at about 40 K. We infer that doping up to the optimum level does not shift the chemical potential, unlike in ordinary Fermi liquids. This result poses a new challenge to theory--cuprate superconductors have not run out of surprises. PMID:23913171

  5. Gibbs free energy difference between the undercooled liquid and the beta phase of a Ti-Cr alloy

    NASA Technical Reports Server (NTRS)

    Ohsaka, K.; Trinh, E. H.; Holzer, J. C.; Johnson, W. L.

    1992-01-01

    The heat of fusion and the specific heats of the solid and liquid have been experimentally determined for a Ti60Cr40 alloy. The data are used to evaluate the Gibbs free energy difference, delta-G, between the liquid and the beta phase as a function of temperature to verify a reported spontaneous vitrification (SV) of the beta phase in Ti-Cr alloys. The results show that SV of an undistorted beta phase in the Ti60Cr40 alloy at 873 K is not feasible because delta-G is positive at the temperature. However, delta-G may become negative with additional excess free energy to the beta phase in the form of defects.

  6. YIELDS OF IONS AND EXCITED STATES IN NONPOLAR LIQUIDS EXPOSED TO X-RAYS OF 1 TO 30 KEV ENERGY

    SciTech Connect

    HOLROYD,R.A.

    1999-08-18

    When x-rays from a synchrotron source are absorbed in a liquid, the x-ray energy (E{sub x}) is converted by the photoelectric effect into the kinetic energy of the electrons released. For hydrocarbons, absorption by the K-electrons of carbon dominates. Thus the energy of the photoelectron (E{sub pe}) is E{sub x}-E{sub b}, where E{sub b} is the K-shell binding energy of carbon. Additional electrons with energy equal to E{sub b} is released in the Auger process that fills the hole in the K-shell. These energetic electrons will produce many ionizations, excitations and products. The consequences of the high density of ionizations and excitations along the track of the photoelectron and special effects near the K-edge are examined here.

  7. Formation of liquid crystal multi-domains with different threshold voltages by varying the surface anchoring energy

    NASA Astrophysics Data System (ADS)

    Lee, Ji-Hoon; Jin, Huillian; Kim, Jung-Wook; Kim, Ki-Han; Park, Byung Wok; Yoon, Tae-Hoon; Kim, Hoon; Shin, Ki-Chul; Kim, Hee Seop

    2012-09-01

    We propose methods to obtain multi-domains with different threshold voltages for vertically aligned liquid crystal displays without additional transistors or capacitors. We exposed an ultraviolet light through a photomask and spatially varied the surface anchoring energy by partially decomposing the polyimide or inducing the adsorption of reactive monomers. The threshold voltage was reduced with smaller surface anchoring, and the reduction of the threshold could be qualitatively interpreted using a model describing a weak anchoring condition.

  8. Low-energy ionization yield in liquid argon for a coherent neutrino-nucleus scatter detector

    NASA Astrophysics Data System (ADS)

    Foxe, Michael P.

    ~ 4 e-- per keVr at 8 keVr. For gaseous Ar, the nuclear ionization quench factor is predicted to be ~ 0.13 at 10 keVr, which is the upper limit on this quantity obtained from the atomic collision model. In order to confidently apply the predictions of the ionization yield model, several experiments have been carried out for its validation. A single-phase Ar detector is used to both understand the processes occurring in the amplification region of a dual-phase Ar detector and to measure the nuclear ionization quench factor (ratio of the ionization signal produced in a nuclear recoil compared to that produced in an electron recoil of equal energy) in gaseous Ar. Using a portable neutron generator based on the 7Li(p,n)7 Be reaction, the nuclear ionization quench factor at 13 keVr was measured in gaseous Ar to be 0:138--0:012, which is in good agreement with the predictions of the ionization yield model. The absolute ionization yield was not measurable in gaseous Ar, because single ionization electron sensitivity has not been achieved in the single-phase Ar detector. The Gamma or Neutron Argon Recoils Resulting in Liquid Ionization (G/NARRLI) detector is a dual-phase Ar detector, which was developed to measure the ionization yield at energies below 10 keVr. While operating the G/NARRLI detector, high purity was achieved, extending the electron lifetime to ≈ 100 -- 200 micros. The ultimate sensitivity was achieved by detecting the single ionization electron peak. Detection of the single electron peak allowed absolutely calibrated spectroscopy to be performed using 55Fe to produce a 6 keV peak and 37Ar to produce a peak at 2.822 keV and a low-energy peak at 270 eV. Spectroscopic detection of the 270 eV peak represents the lowest energy measured to date in a dual-phase Ar detector. The electron yields for the 55Fe and 37Ar sources were used for the validation of the electron transport code, which was in good agreement with the modeling results. An effort was made to

  9. Anharmonic exciton dynamics and energy dissipation in liquid water from two-dimensional infrared spectroscopy.

    PubMed

    De Marco, Luigi; Fournier, Joseph A; Thämer, Martin; Carpenter, William; Tokmakoff, Andrei

    2016-09-01

    Water's extended hydrogen-bond network results in rich and complex dynamics on the sub-picosecond time scale. In this paper, we present a comprehensive analysis of the two-dimensional infrared (2D IR) spectrum of O-H stretching vibrations in liquid H2O and their interactions with bending and intermolecular vibrations. By exploring the dependence of the spectrum on waiting time, temperature, and laser polarization, we refine our molecular picture of water's complex ultrafast dynamics. The spectral evolution following excitation of the O-H stretching resonance reveals vibrational dynamics on the 50-300 fs time scale that are dominated by intermolecular delocalization. These O-H stretch excitons are a result of the anharmonicity of the nuclear potential energy surface that arises from the hydrogen-bonding interaction. The extent of O-H stretching excitons is characterized through 2D depolarization measurements that show spectrally dependent delocalization in agreement with theoretical predictions. Furthermore, we show that these dynamics are insensitive to temperature, indicating that the exciton dynamics alone set the important time scales in the system. Finally, we study the evolution of the O-H stretching mode, which shows highly non-adiabatic dynamics suggestive of vibrational conical intersections. We argue that the so-called heating, commonly observed within ∼1 ps in nonlinear IR spectroscopy of water, is a nonequilibrium state better described by a kinetic temperature rather than a Boltzmann distribution. Our conclusions imply that the collective nature of water vibrations should be considered in describing aqueous solvation. PMID:27608998

  10. Preconception Carrier Screening

    MedlinePlus

    ... What can the results of a carrier screening test tell me? A genetic counselor or your health care provider will use the results to calculate the ... the publisher. Related FAQs Genetic Disorders (FAQ094) Screening Tests for Birth Defects ... Education & Events Annual Meeting CME Overview CREOG ...

  11. Common Carrier Services.

    ERIC Educational Resources Information Center

    Federal Communications Commission, Washington, DC.

    This bulletin outlines the Federal Communications Commission's (FCC) responsibilities in regulating the interstate and foreign common carrier communication via electrical means. Also summarized are the history, technological development, and current capabilities and prospects of telegraph, wire telephone, radiotelephone, satellite communications,…

  12. The Direct Calculation of Solid and Liquid Free Energies of Metals and Alloys Using the Embedded Atom Method

    NASA Astrophysics Data System (ADS)

    Song, Xueyu; Morris, James

    2003-03-01

    We present a method of directly and accurately calculating the free energy of metals and alloys, directly from models such as the Embedded Atom Method (EAM). An effective pair potential is defined, and used in an extended Weeks-Chandler-Andersen (WCA) approach. An effective hard-sphere density is defined, and perturbations from the hard-sphere limit are calculated using the pair correlation functions calculated from density functional theory. Calculations using the Mei and Davenport EAM potential for Al, with the modifications of Sturgeon and Laird, demonstrate the accuracy of the approach for both the liquid and solid phases by comparison with simulations. These results are the first step toward the direct calculation of the solid-liquid interfacial free energy for metallic systems, an important parameter for classical nucleation theory and for solidification dynamics. Our recent simulation results for the interfacial free energy provides an important test of the inhomogeneous theory. We also present preliminary results for binary systems, where the direct calculation of phase diagrams based upon the inter-atomic potentials will be compared with simulations. The approach will also allow for the direct calculation of the properties of under-cooled liquid metals and alloys.

  13. A Low-cost, High-yield Process for the Direct Productin of High Energy Density Liquid Fuel from Biomass

    SciTech Connect

    Agrawal, Rakesh

    2014-02-21

    The primary objective and outcome of this project was the development and validation of a novel, low-cost, high-pressure fast-hydropyrolysis/hydrodeoxygenation (HDO) process (H{sub 2}Bioil) using supplementary hydrogen (H{sub 2}) to produce liquid hydrocarbons from biomass. The research efforts under the various tasks of the project have culminated in the first experimental demonstration of the H2Bioil process, producing 100% deoxygenated >C4+ hydrocarbons containing 36-40% of the carbon in the feed of pyrolysis products from biomass. The demonstrated H{sub 2}Bioil process technology (i.e. reactor, catalyst, and downstream product recovery) is scalable to a commercial level and is estimated to be economically competitive for the cases when supplementary H{sub 2} is sourced from coal, natural gas, or nuclear. Additionally, energy systems modeling has revealed several process integration options based on the H{sub 2}Bioil process for energy and carbon efficient liquid fuel production. All project tasks and milestones were completed or exceeded. Novel, commercially-scalable, high-pressure reactors for both fast-hydropyrolysis and hydrodeoxygenation were constructed, completing Task A. These reactors were capable of operation under a wide-range of conditions; enabling process studies that lead to identification of optimum process conditions. Model compounds representing biomass pyrolysis products were studied, completing Task B. These studies were critical in identifying and developing HDO catalysts to target specific oxygen functional groups. These process and model compound catalyst studies enabled identification of catalysts that achieved 100% deoxygenation of the real biomass feedstock, sorghum, to form hydrocarbons in high yields as part of Task C. The work completed during this grant has identified and validated the novel and commercially scalable H2Bioil process for production of hydrocarbon fuels from biomass. Studies on model compounds as well as real biomass

  14. Results of low energy background measurements with the Liquid Scintillation Detector (LSD) of the Mont Blanc Laboratory

    NASA Technical Reports Server (NTRS)

    Aglietta, M.; Badino, G.; Bologna, G. F.; Castagnoli, C.; Fulgione, W.; Galeotti, P.; Saavedra, O.; Trinchero, G. C.; Vernetto, S.; Dadykin, V. L.

    1985-01-01

    The 90 tons liquid scintillation detector (LSD) is fully running since October 1984, at a depth of 5,200 hg/sq cm of standard rock underground. The main goal is to search for neutrino bursts from collapsing stars. The experiment is very sensitive to detect low energy particles and has a very good signature to gamma-rays from (n,p) reaction which follows the upsilon e + p yields n + e sup + neutrino capture. The analysis of data is presented and the preliminary results on low energy measurements are discussed.

  15. Sealed substrate carrier for electroplating

    DOEpatents

    Ganti, Kalyana Bhargava

    2012-07-17

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The substrate carrier includes a non-conductive carrier body on which the substrates are held, and conductive lines are embedded within the carrier body. A conductive bus bar is embedded into a top side of the carrier body and is conductively coupled to the conductive lines. A thermoplastic overmold covers a portion of the bus bar, and there is a plastic-to-plastic bond between the thermoplastic overmold and the non-conductive carrier body. Other embodiments, aspects and features are also disclosed.

  16. Theoretical and computational studies of renewable energy materials: Room temperature ionic liquids and proton exchange membranes

    NASA Astrophysics Data System (ADS)

    Feng, Shulu

    2011-12-01

    Two kinds of renewable energy materials, room temperature ionic liquids (RTILs) and proton exchange membranes (PEMs), especially Nafion, are studied by computational and theoretical approaches. The ultimate purpose of the present research is to design novel materials to meet the future energy demands. To elucidate the effect of alkyl side chain length and anion on the structure and dynamics of the mixtures, molecular dynamics (MD) simulations of three RTILs/water mixtures at various water mole fractions: 1-butyl-3-methylimidazolium (BMIM+)/BF4-, 1-octyl-3-methylimidazolium (OMIM+)/BF4-, and OMIM +/Cl- are performed. Replacing the BMIM + cation with OMIM+ results in stronger aggregation of the cations as well as a slower diffusion of the anions, and replacing the BF4- anion with Cl- alters the water distribution at low water mole fractions and slows diffusion of the mixtures. Potential experimental manifestations of these behaviors in both cases are provided. Proton solvation properties and transport mechanisms are studied in hydrated Nafion, by using the self-consistent multistate empirical valence bond (SCI-MS-EVB) method. It is found that by stabilizing a more Zundel-like (H5O 2+) structure in the first solvation shells, the solvation of excess protons, as well as the proton hydration structure are both influenced by the sulfonate groups. Hydrate proton-related hydrogen bond networks are observed to be more stable than those with water alone. In order to characterize the nature of the proton transport (PT), diffusive motion, Arrhenius activation energies, and transport pathways are calculated and analyzed. Analysis of diffusive motion suggests that (1) a proton-hopping mechanism dominates the proton transport for the studied water loading levels and (2) there is an obvious degree of anti-correlation between the proton hopping and the vehicular transport. The activation energy drops rapidly with an increasing water content when the water loading level is smaller

  17. Generation of charge carriers in C60 films by 100-fs laser pulses with photon energies above and below the mobility edge

    SciTech Connect

    Chekalin, Sergei V; Yartsev, A P; Sundstroem, V

    2001-05-31

    Primary stages of photoinduced processes are studied in C60 films excited by 100-fs laser pulses at wavelengths of 645 and 367 nm, the fraction of excited molecules being no more than several percent. Probing in the broad spectral range from 400 to 1100 nm showed that both charged (cations and electrons) and neutral (excited molecules) components were produced upon irradiation by the laser pulse. For both excitation wavelengths, charge carriers were produced due to direct optical excitation rather than due to singlet-singlet annihilation. Anions were produced with a delay of 10{sup -13} - 10{sup -11} s through electron trapping by C60 molecules. (femtosecond technologies)

  18. Numerical determination of the interfacial energy and nucleation barrier of curved solid-liquid interfaces in binary systems

    NASA Astrophysics Data System (ADS)

    Kundin, Julia; Choudhary, Muhammad Ajmal

    2016-07-01

    The phase-field crystal (PFC) technique is a widely used approach for modeling crystal growth phenomena with atomistic resolution on mesoscopic time scales. We use a two-dimensional PFC model for a binary system based on the work of Elder et al. [Phys. Rev. B 75, 064107 (2007), 10.1103/PhysRevB.75.064107] to study the effect of the curved, diffuse solid-liquid interface on the interfacial energy as well as the nucleation barrier. The calculation of the interfacial energy and the nucleation barrier certainly depends on the proper definition of the solid-liquid dividing surface and the corresponding nucleus size. We define the position of the sharp interface at which the interfacial energy is to be evaluated by using the concept of equimolar dividing surface (re) and the minimization of the interfacial energy (rs). The comparison of the results based on both radii shows that the difference re-rs is always positive and has a limit for large cluster sizes which is comparable to the Tolman length. Furthermore, we found the real nucleation barrier for small cluster sizes, which is defined as a function of the radius rs, and compared it with the classical nucleation theory. The simulation results also show that the extracted interfacial energy as function of both radii is independent of system size, and this dependence can be reasonably described by the nonclassical Tolman formula with a positive Tolman length.

  19. Beamline electrostatic levitator for in situ high energy x-ray diffraction studies of levitated solids and liquids

    SciTech Connect

    Gangopadhyay, A.K.; Lee, G.W.; Kelto, K.F.; Rogers, J.R.; Goldman, A.I.; Robinson, D.S.; Rathz, T.J.; Hyers, R.W.

    2010-07-19

    Determinations of the phase formation sequence, crystal structures and the thermo-physical properties of materials at high temperatures are hampered by contamination from the sample container and environment. Containerless processing techniques, such as electrostatic (ESL), electromagnetic, aerodynamic, and acoustic levitation, are most suitable for these studies. An adaptation of ESL for in situ structural studies of a wide range of materials using high energy (30-130 keV) x rays at a synchrotron source is described here. This beamline ESL (BESL) allows the in situ determination of the atomic structures of equilibrium solid and liquid phases, undercooled liquids and time-resolved studies of solid-solid and liquid-solid phase transformations. The use of area detectors enables the rapid acquisition of complete diffraction patterns over a wide range (0.5-14 {angstrom}{sup -1}) of reciprocal space. The wide temperature range (300-2500 K), containerless processing environment under high vacuum (10{sup -7}-10{sup -8} Torr), and fast data acquisition capability, make BESL particularly well suited for phase stability studies of high temperature solids and liquids. An additional, but important, feature of BESL is the capability for simultaneous measurements of a host of thermo-physical properties including the specific heat, enthalpy of transformation, solidus and liquidus temperatures, density, viscosity, and surface tension, all on the same sample during the structural measurements.

  20. Template-free preparation of crystalline Ge nanowire film electrodes via an electrochemical liquid-liquid-solid process in water at ambient pressure and temperature for energy storage.

    PubMed

    Gu, Junsi; Collins, Sean M; Carim, Azhar I; Hao, Xiaoguang; Bartlett, Bart M; Maldonado, Stephen

    2012-09-12

    The direct electrodeposition of crystalline germanium (Ge) nanowire film electrodes from an aqueous solution of dissolved GeO(2) using discrete 'flux' nanoparticles capable of dissolving Ge(s) has been demonstrated. Electrodeposition of Ge at inert electrode substrates decorated with small (<100 nm), discrete indium (In) nanoparticles resulted in crystalline Ge nanowire films with definable nanowire diameters and densities without the need for a physical or chemical template. The Ge nanowires exhibited strong polycrystalline character as-deposited, with approximate crystallite dimensions of 20 nm and a mixed orientation of the crystallites along the length of the nanowire. Energy dispersive spectroscopic elemental mapping of individual Ge nanowires showed that the In nanoparticles remained at the base of each nanowire, indicating good electrical communication between the Ge nanowire and the underlying conductive support. As-deposited Ge nanowire films prepared on Cu supports were used without further processing as Li(+) battery anodes. Cycling studies performed at 1 C (1624 mA g(-1)) indicated the native Ge nanowire films supported stable discharge capacities at the level of 973 mA h g(-1), higher than analogous Ge nanowire film electrodes prepared through an energy-intensive vapor-liquid-solid nanowire growth process. The cumulative data show that ec-LLS is a viable method for directly preparing a functional, high-activity nanomaterials-based device component. The work presented here is a step toward the realization of simple processes that make fully functional energy conversion/storage technologies based on crystalline inorganic semiconductors entirely through benchtop, aqueous chemistry and electrochemistry without time- or energy-intensive process steps. PMID:22900746

  1. Bimodal behaviour of charge carriers in graphene induced by electric double layer.

    PubMed

    Tsai, Sing-Jyun; Yang, Ruey-Jen

    2016-01-01

    A theoretical investigation is performed into the electronic properties of graphene in the presence of liquid as a function of the contact area ratio. It is shown that the electric double layer (EDL) formed at the interface of the graphene and the liquid causes an overlap of the conduction bands and valance bands and increases the density of state (DOS) at the Fermi energy (EF). In other words, a greater number of charge carriers are induced for transport and the graphene changes from a semiconductor to a semimetal. In addition, it is shown that the dependence of the DOS at EF on the contact area ratio has a bimodal distribution which responses to the experimental observation, a pinnacle curve. The maximum number of induced carriers is expected to occur at contact area ratios of 40% and 60%. In general, the present results indicate that modulating the EDL provides an effective means of tuning the electronic properties of graphene in the presence of liquid. PMID:27464986

  2. Bimodal behaviour of charge carriers in graphene induced by electric double layer

    PubMed Central

    Tsai, Sing-Jyun; Yang, Ruey-Jen

    2016-01-01

    A theoretical investigation is performed into the electronic properties of graphene in the presence of liquid as a function of the contact area ratio. It is shown that the electric double layer (EDL) formed at the interface of the graphene and the liquid causes an overlap of the conduction bands and valance bands and increases the density of state (DOS) at the Fermi energy (EF). In other words, a greater number of charge carriers are induced for transport and the graphene changes from a semiconductor to a semimetal. In addition, it is shown that the dependence of the DOS at EF on the contact area ratio has a bimodal distribution which responses to the experimental observation, a pinnacle curve. The maximum number of induced carriers is expected to occur at contact area ratios of 40% and 60%. In general, the present results indicate that modulating the EDL provides an effective means of tuning the electronic properties of graphene in the presence of liquid. PMID:27464986

  3. ASSESSING THE ENVIRONMENTAL IMPACT OF FOSSIL-FUEL BASED ENERGY SOURCES: MEASUREMENT OF ORGANOMETAL SPECIES IN BIOLOGICAL AND WATER SAMPLES USING LIQUID CHROMATOGRAPHY WITH ELECTROCHEMICAL DETECTION

    EPA Science Inventory

    A new measurement approach for the determination of trace organometals in energy related environmental samples is described. The method is based on liquid chromatographic separation with electrochemical detection. A detailed description of the development of the electrochemical d...

  4. Synthesis of TiO2 Materials Using Ionic Liquids and Its Applications for Sustainable Energy and Environment.

    PubMed

    Yoo, Kye Sang

    2016-05-01

    Titanium dioxide (TiO2) has received significant attention because of the global climate change and the consumption of fossil fuel resources. Specifically, using TiO2 in photocatalytic applications, such as the removal of organic pollutants and a hydrogen production has become an important issue. Thus, many researchers have attempted to prepare highly active TiO2 materials using various synthetic approaches. Modifications of the conventional sol-gel method, such as the addition of surfactants, have been employed in synthetic procedures. Moreover, hydrothermal, solvothermal, sonochemical and microwave methods have also been used as alternative approaches. Recently, the use of ionic liquids represents a burgeoning direction in inorganic material synthesis. Ionic liquids are exceptional solvents consisting of ions possessing low vapor pressure and tunable solvent properties. This article reviews the preparation of TiO2 materials using ionic liquids with various synthetic approaches. Also, sustainable energy and environmental cleanup applications of TiO2 materials, including the treatment of hazardous organic substances and hydrogen energy derived from electrochemical methods, are discussed. PMID:27483750

  5. Yarn carrier with clutch

    NASA Technical Reports Server (NTRS)

    Doyne, Richard A. (Inventor); Benson, Rio H. (Inventor); El-Shiekh, Aly (Inventor)

    1994-01-01

    A yarn carrier apparatus particularly suited for use in braiding machinery or the like due to its capability of continuous yarn feeding and retraction of long lengths of yarn. The yarn carrier apparatus comprises a yarn supply spool which is rotatably mounted within the housing, a spring motor also mounted within the housing and operatively connected to the yarn supply spool through a mechanical transmission assembly which is adapted to multiply rotational movement between the first element of the gear assembly operatively connected to the spring motor and the final element of the gear assembly operatively connected to the yarn supply spool. The spring motor is adapted to tension the yarn during both feeding and retraction thereof, and it is further adapted to periodically rotatably slip within the housing and partially unwind so as to allow for continuous withdrawal of a long length of yarn without the spring motor becoming fully wound and preventing further yarn retraction.

  6. LNG carrier using membrane tank system delivered

    SciTech Connect

    Not Available

    1993-12-06

    The world's first LNG carrier that incorporates the Technigaz Mark 3 membrane tank system was delivered in October to its owner, Asia LNG Transport Sdn. Bhd., a joint venture between Nippon Yusen K.K. and Perbadanan Nasional Shipping Line Berhad of Malaysia. NKK built the 18,800 cu m, fully double-hull carrier Aman Bintulu at its Tsu works. Construction was completed in September with more than 2 months of sea trials and gas tests using [minus]190 C. Liquid nitrogen and final gas trails with LNG. The orthogonally corrugated stainless membrane primary barrier and the triplex (aluminum foil/fiber glass cloth) composite-material secondary barrier prevent LNG from leaking in the event of an accident.

  7. Charge carrier mobility and concentration as a function of composition in AgPO3-AgI glasses

    NASA Astrophysics Data System (ADS)

    Rodrigues, Ana Candida Martins; Nascimento, Marcio Luis Ferreira; Bragatto, Caio Barca; Souquet, Jean-Louis

    2011-12-01

    Conductivity data of the xAgI(1 - x)AgPO3 system (0 ≤ x ≤ 0.5) were collected in the liquid and glassy states. The difference in the dependence of ionic conductivity on temperature below and above their glass transition temperatures (Tg) is interpreted by a discontinuity in the charge carrier's mobility mechanisms. Charge carrier displacement occurs through an activated mechanism below Tg and through a Vogel-Fulcher-Tammann-Hesse mechanism above this temperature. Fitting conductivity data with the proposed model allows one to determine separately the enthalpies of charge carrier formation and migration. For the five investigated compositions, the enthalpy of charge carrier formation is found to decrease, with x, from 0.86 to 0.2 eV, while the migration enthalpy remains constant at ≈0.14 eV. Based on these values, the charge carrier mobility and concentration in the glassy state can then be calculated. Mobility values at room temperature (≈10-4 cm2 V-1 s-1) do not vary significantly with the AgI content and are in good agreement with those previously measured by the Hall-effect technique. The observed increase in ionic conductivity with x would thus only be due to an increase in the effective charge carrier concentration. Considering AgI as a weak electrolyte, the change in the effective charge carrier concentration is justified and is correlated to the partial free energy of silver iodide forming a regular solution with AgPO3.

  8. Landau Energy Loss in Liquid Scintillator and the Search for Wifs with the LVD Experiment.

    NASA Astrophysics Data System (ADS)

    Tang, Jie

    The LVD experiment at Gran Sasso, Italy, is described, and data since the completion of the first tower (one fifth of the whole LVD) are analyzed. The dE/dx distribution of reconstructed high-energy muons in the scintillator counters is obtained. This distribution is compared with predictions by a GEANT3 Monte Carlo simulation of cosmic muons going through the LVD detector. Its shape is similar to the Landau approximation. In the data from a total running time of 245 days, 159286 clearly separable charged tracks going through the detector were reconstructed. No WIF (Weakly-Interacting Fractionally-charged particle) is observed. Since the early 1930's to the 1980's, theories on the dE/dx distribution of charged particles in matter have evolved from the fundamental work done by Bethe, Bloch, Landau, Symon, Vavilov and others with the inclusion of more precise corrections of the density effect and the shell effect. At the LVD experiment, through a procedure of gain-factor calibration at every period of 20 days, to compensate for instability and nonuniformity of the scintillator counters and their readout, the muon dE/dx distribution is measured; it conforms to the Landau approximation. The precision of the dE/dx measurement is 7.6% (one sigma).. WIF particles are speculated by modern theories. Because dE/dx is proportional to the square of the charge carried by the incident particle, any WIF going through the LVD liquid scintillator will reveal itself by its dE/dx being on the low side of the carefully calibrated muon dE/dx distribution. Calculation has shown that when the charge of a WIF is as low as {2over 3} e, it still generates enough ionization in the LVD limited streamer tubes and thus its track is as visible as a muon track in the detector. Such events are not found. Assuming a uniform flux distribution of WIF particles coming from the atmosphere, the upper limit of their flux at the LVD site is 4.4 times rm 10^{-14} cm^{-2}sterad ^{-1}sec^{-1}. (Copies

  9. Converting oil shale to liquid fuels: energy inputs and greenhouse gas emissions of the Shell in situ conversion process.

    PubMed

    Brandt, Adam R

    2008-10-01

    Oil shale is a sedimentary rock that contains kerogen, a fossil organic material. Kerogen can be heated to produce oil and gas (retorted). This has traditionally been a CO2-intensive process. In this paper, the Shell in situ conversion process (ICP), which is a novel method of retorting oil shale in place, is analyzed. The ICP utilizes electricity to heat the underground shale over a period of 2 years. Hydrocarbons are produced using conventional oil production techniques, leaving shale oil coke within the formation. The energy inputs and outputs from the ICP, as applied to oil shales of the Green River formation, are modeled. Using these energy inputs, the greenhouse gas (GHG) emissions from the ICP are calculated and are compared to emissions from conventional petroleum. Energy outputs (as refined liquid fuel) are 1.2-1.6 times greater than the total primary energy inputs to the process. In the absence of capturing CO2 generated from electricity produced to fuel the process, well-to-pump GHG emissions are in the range of 30.6-37.1 grams of carbon equivalent per megajoule of liquid fuel produced. These full-fuel-cycle emissions are 21%-47% larger than those from conventionally produced petroleum-based fuels. PMID:18939591

  10. Technical Note: Improvements in GEANT4 energy-loss model and the effect on low-energy electron transport in liquid water

    SciTech Connect

    Kyriakou, I.; Incerti, S.

    2015-07-15

    Purpose: The GEANT4-DNA physics models are upgraded by a more accurate set of electron cross sections for ionization and excitation in liquid water. The impact of the new developments on low-energy electron transport simulations by the GEANT4 Monte Carlo toolkit is examined for improving its performance in dosimetry applications at the subcellular and nanometer level. Methods: The authors provide an algorithm for an improved implementation of the Emfietzoglou model dielectric response function of liquid water used in the GEANT4-DNA existing model. The algorithm redistributes the imaginary part of the dielectric function to ensure a physically motivated behavior at the binding energies, while retaining all the advantages of the original formulation, e.g., the analytic properties and the fulfillment of the f-sum-rule. In addition, refinements in the exchange and perturbation corrections to the Born approximation used in the GEANT4-DNA existing model are also made. Results: The new ionization and excitation cross sections are significantly different from those of the GEANT4-DNA existing model. In particular, excitations are strongly enhanced relative to ionizations, resulting in higher W-values and less diffusive dose-point-kernels at sub-keV electron energies. Conclusions: An improved energy-loss model for the excitation and ionization of liquid water by low-energy electrons has been implemented in GEANT4-DNA. The suspiciously low W-values and the unphysical long tail in the dose-point-kernel have been corrected owing to a different partitioning of the dielectric function.

  11. Spectroscopy of carrier multiplication in nanocrystals.

    PubMed

    Bruhn, Benjamin; Limpens, Rens; Chung, Nguyen Xuan; Schall, Peter; Gregorkiewicz, Tom

    2016-01-01

    Carrier multiplication in nanostructures promises great improvements in a number of widely used technologies, among others photodetectors and solar cells. The decade since its discovery was ridden with fierce discussions about its true existence, magnitude, and mechanism. Here, we introduce a novel, purely spectroscopic approach for investigation of carrier multiplication in nanocrystals. Applying this method to silicon nanocrystals in an oxide matrix, we obtain an unambiguous spectral signature of the carrier multiplication process and reveal details of its size-dependent characteristics-energy threshold and efficiency. The proposed method is generally applicable and suitable for both solid state and colloidal samples, as well as for a great variety of different materials. PMID:26852922

  12. Spectroscopy of carrier multiplication in nanocrystals

    PubMed Central

    Bruhn, Benjamin; Limpens, Rens; Chung, Nguyen Xuan; Schall, Peter; Gregorkiewicz, Tom

    2016-01-01

    Carrier multiplication in nanostructures promises great improvements in a number of widely used technologies, among others photodetectors and solar cells. The decade since its discovery was ridden with fierce discussions about its true existence, magnitude, and mechanism. Here, we introduce a novel, purely spectroscopic approach for investigation of carrier multiplication in nanocrystals. Applying this method to silicon nanocrystals in an oxide matrix, we obtain an unambiguous spectral signature of the carrier multiplication process and reveal details of its size-dependent characteristics-energy threshold and efficiency. The proposed method is generally applicable and suitable for both solid state and colloidal samples, as well as for a great variety of different materials. PMID:26852922

  13. Energy Carriers Use in the World: Natural Gas - Conventional and Unconventional Gas Resources / Wykorzystanie Nośników Energii w Świecie: Zasoby Gazu Ziemnego w Złożach Konwencjonalnych i Niekonwencjonalnych

    NASA Astrophysics Data System (ADS)

    Siemek, Jakub; Nagy, Stanisław

    2012-11-01

    This paper discusses forecasts of energy carrier use with particular emphasis on the changing position of natural gas due to global climatic conditions and the increasing role of unconventional natural gas reservoirs. Allocation of natural gas resources in the world are discussed as well as global gas consumption and conditions for development of transport infrastructure and storage. The most important indicators of the energy security of countries are presented. The basic properties of unconventional deposits, and differences in the production/extraction of gas from the conventional and unconventional fields are given. In the paper are also discussed natural gas reserves in Poland, including possible non-conventional resources in the fields and issues of increasing the role of gas as an energy carrier in Poland in the background of the energy changes in Europe and the world. W pracy omówiono prognozy energetyczne wykorzystania energii ze szczególnym uwzględnieniem zmieniającej się pozycji gazu ziemnego z uwagi na uwarunkowania klimatyczne oraz wzrastającą role niekonwencjonalnych złóż gazu ziemnego. Omówiono alokację zasobów gazu ziemnego w świecie, zużycie gazu w regionach oraz warunki rozbudowy infrastruktury transportu i magazynowania. Przedstawiono najważniejsze wskaźniki dotyczące bezpieczeństwa energetycznego krajów. Omówiono podstawowe własności złóż niekonwencjonalnych oraz różnice w charakterze wydobycia gazu ze złóż konwencjonalnych i niekonwencjonalnych. Omówiono zasoby gazu w Polsce, w tym możliwe zasoby w złożach niekonwencjonalnych oraz zagadnienia zwiększenia roli gazu jako nośnika energii w Polsce w tle energetycznych zmian Europy i świata.

  14. Characterization of gas-expanded liquid-deposited gold nanoparticle films on substrates of varying surface energy.

    PubMed

    Hurst, Kendall M; Roberts, Christopher B; Ashurst, W Robert

    2011-01-18

    Dodecanethiol-stabilized gold nanoparticles (AuNPs) were deposited via a gas-expanded liquid (GXL) technique utilizing CO(2)-expanded hexane onto substrates of different surface energy. The different surface energies were achieved by coating silicon (100) substrates with various organic self-assembled monolayers (SAMs). Following the deposition of AuNP films, the films were characterized to determine the effect of substrate surface energy on nanoparticle film deposition and growth. Interestingly, the critical surface tension of a given substrate does not directly describe nanoparticle film morphology. However, the results in this study indicate a shift between layer-by-layer and island film growth based on the critical surface tension of the capping ligand. Additionally, the fraction of surface area covered by the AuNP film decreases as the oleophobic nature of the surfaces increases. On the basis of this information, the potential exists to engineer nanoparticle films with desired morphologies and characteristics. PMID:21174390

  15. Maintainable substrate carrier for electroplating

    SciTech Connect

    Chen, Chen-An; Abas, Emmanuel Chua; Divino, Edmundo Anida; Ermita, Jake Randal G.; Capulong, Jose Francisco S.; Castillo, Arnold Villamor; Ma; Diana Xiaobing

    2012-07-17

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The carrier includes a non-conductive carrier body on which the substrates are placed and conductive lines embedded within the carrier body. A plurality of conductive clip attachment parts are attached in a permanent manner to the conductive lines embedded within the carrier body. A plurality of contact clips are attached in a removable manner to the clip attachment parts. The contact clips hold the substrates in place and conductively connecting the substrates with the conductive lines. Other embodiments, aspects and features are also disclosed.

  16. Maintainable substrate carrier for electroplating

    DOEpatents

    Chen, Chen-An; Abas, Emmanuel Chua; Divino, Edmundo Anida; Ermita, Jake Randal G.; Capulong, Jose Francisco S.; Castillo, Arnold Villamor; Ma, Diana Xiaobing

    2016-08-02

    One embodiment relates to a substrate carrier for use in electroplating a plurality of substrates. The carrier includes a non-conductive carrier body on which the substrates are placed and conductive lines embedded within the carrier body. A plurality of conductive clip attachment parts are attached in a permanent manner to the conductive lines embedded within the carrier body. A plurality of contact clips are attached in a removable manner to the clip attachment parts. The contact clips hold the substrates in place and conductively connecting the substrates with the conductive lines. Other embodiments, aspects and features are also disclosed.

  17. Free energy perturbation method for measuring elastic constants of liquid crystals

    NASA Astrophysics Data System (ADS)

    Joshi, Abhijeet

    There is considerable interest in designing liquid crystals capable of yielding specific morphological responses in confined environments, including capillaries and droplets. The morphology of a liquid crystal is largely dictated by the elastic constants, which are difficult to measure and are only available for a handful of substances. In this work, a first-principles based method is proposed to calculate the Frank elastic constants of nematic liquid crystals directly from atomistic models. These include the standard splay, twist and bend deformations, and the often-ignored but important saddle-splay constant. The proposed method is validated using a well-studied Gay-Berne(3,5,2,1) model; we examine the effects of temperature and system size on the elastic constants in the nematic and smectic phases. We find that our measurements of splay, twist, and bend elastic constants are consistent with previous estimates for the nematic phase. We further outline the implementation of our approach for the saddle-splay elastic constant, and find it to have a value at the limits of the Ericksen inequalities. We then proceed to report results for the elastic constants commonly known liquid crystals namely 4-pentyl-4'-cynobiphenyl (5CB) using atomistic model, and show that the values predicted by our approach are consistent with a subset of the available but limited experimental literature.

  18. Vapor-Liquid Equilibria Using the Gibbs Energy and the Common Tangent Plane Criterion

    ERIC Educational Resources Information Center

    Olaya, Maria del Mar; Reyes-Labarta, Juan A.; Serrano, Maria Dolores; Marcilla, Antonio

    2010-01-01

    Phase thermodynamics is often perceived as a difficult subject with which many students never become fully comfortable. The Gibbsian geometrical framework can help students to gain a better understanding of phase equilibria. An exercise to interpret the vapor-liquid equilibrium of a binary azeotropic mixture, using the equilibrium condition based…

  19. Synthesis of Mesoporous Carbons from Rice Husk for Supercapacitors with High Energy Density in Ionic Liquid Electrolytes.

    PubMed

    He, Xiaojun; Zhang, Hebao; Xie, Kang; Xia, Youyi; Zhao, Zhigang; Wang, Xiaoting

    2016-03-01

    High-performance mesoporous carbons (MCs) for supercapacitors were made from rice husk by one-step microwave-assisted ZnCl2 activation. The microstructures of MCs as-made were characterized by field emission scanning electron microscopy and transmission electron microscopy. The pore structure parameters of MCs were obtained by N2 adsorption technique. The electrochemical properties of MC electrodes were studied by constant current charge-discharge, cyclic voltammetry and electrochemical impedance spectroscopy in different electrolytes. The results showed that the specific surface area of MC4 made at the ZnCl2/rice husk mass of 4:1 reached 1737 m2 g(-1). The specific capacitance and energy density of the electrodes fabricated from the mixture of MC4 and microporous carbon increased with the mass percentage of MC4, reaching 157 F g(-1) and 84 Wh kg(-1) at 0.05 A g(-1), and showed good cycle stability in 1-butyl-3-methylimidazolium hexafluorophosphate electrolyte. Compared to the often-used aqueous and organic electrolytes, MC4 capacitor exhibited extremely high energy density in ionic liquid electrolyte, remaining at 28 Wh kg(-1) at 1684 W kg(-1). This work paves a new way to produce cost-effective MCs from biomass for supercapacitors with extremely high energy density in ionic liquid electrolytes. PMID:27455718

  20. Solvation free energies in [bmim]-based ionic liquids: Anion effect toward solvation of amino acid side chain analogues

    NASA Astrophysics Data System (ADS)

    Latif, Muhammad Alif Mohammad; Micaêlo, Nuno; Abdul Rahman, Mohd Basyaruddin

    2014-11-01

    Stochastic molecular dynamics simulations were performed to investigate the solvation free energy of 15 neutral amino acid side chain analogues in aqueous and five, 1-butyl-3-methylimidazolium ([BMIM])-based ionic liquids. The results in aqueous were found highly correlated with previous experimental and simulation data. Meanwhile, [BMIM]-based RTILs showed better solvation thermodynamics than water to an extent that they were capable of solvating molecules immiscible in water. Non-polar analogues showed stronger solvation in hydrophobic RTIL anions such as [PF6]- and [Tf2N]- while polar analogues showed stronger solvation in the more hydrophilic RTIL anions such as [Cl]-, [TfO]- and [BF4]-.

  1. Instantaneous normal mode theory of diffusion and the potential energy landscape: Application to supercooled liquid CS2

    NASA Astrophysics Data System (ADS)

    Li, Wu-Xiong; Keyes, T.

    1999-09-01

    The pure translation (TR) imaginary-frequency (or unstable) instantaneous normal modes (INM), which we have proposed as representative of barrier crossing and diffusion, are obtained for seven densities and eight temperatures of supercooled and near-melting liquid CS2 via computer simulation. The self-diffusion constant D, with a range of over two decades, has been determined previously for these 56 states [Li and Keyes, J. Chem. Phys. 111, 328 (1999)], allowing a comprehensive test of the relation of INM to diffusion. INM theory is reviewed and extended. At each density Arrhenius T-dependence is found for the fraction fu of unstable modes, for the product <ω>ufu of the fraction times the averaged unstable frequency, and for D. The T-dependence of D is captured very accurately by fu at higher densities and by <ω>ufu at lower densities. Since the T-dependence of <ω>u is weak at high density, the formula D∝<ω>ufu provides a good representation at all densities; it is derived for the case of low-friction barrier crossing. Density-dependent activation energies determined by Arrhenius fits to <ω>ufu are in excellent agreement with those found from D. Thus, activation energies may be obtained with INM, requiring far less computational effort than an accurate simulation of D in supercooled liquids. Im-ω densities of states, <ρuTR(ω,T)>, are fit to the function a(T)ω exp[-(a2(T)ω/√T )a3(T)]. The strong T-dependence of D, absent in Lennard-Jones (LJ) liquids, arises from the multiplicative factor a(T); its activation energy is determined by the inflection-point energy on barriers to diffusion. Values of the exponent a3(T) somewhat greater than 2.0 suggest that liquid CS2 is nonfragile in the extended Angell-Kivelson scheme for the available states. A striking contrast is revealed between CS2 and LJ; a3→2 at low-T in CS2 and at high-T in LJ. The INM interpretation is that barrier height fluctuations in CS2 are negligible at low-T but grow with increasing T

  2. Magnetorheological effect in a suspension with an active carrier fluid

    SciTech Connect

    Kashevskii, B.E.; Kordonskii, V.I.; Prokhorov, I.V.

    1988-07-01

    The main quantitative laws governing the magnetorheological effect in a magnetorheological suspension with an active carrier liquid were established. The family of flow curves obtained for several samples of suspensions of one type of nonmagnetic particle was analyzed. Particles were suspended in a magnetic fluid of the magnetite-kerosite type. The main goal was to establish the law governing rheological similarity by generalizing experimental data with a universal relation while employing a small amount of initial data on the system. The data included the law of magnetization of the magnetic carrier fluid, the law of change in its viscosity in the field, and the law of change in the viscosity of the magnetorheological suspension/active carrier liquid system with an increase in the concentration of nonmagnetic particles in a zero field.

  3. Effect of surface viscosity, anchoring energy, and cell gap on the response time of nematic liquid crystals

    SciTech Connect

    Souza, R.F. de; Yang, D.-Ke; Lenzi, E.K.; Evangelista, L.R.; Zola, R.S.

    2014-07-15

    An analytical expression for the relaxation time of a nematic liquid crystal is obtained for the first time by considering the influence of surface viscosity, anchoring energy strength and cell gap, validated numerically by using the so-called relaxation method. This general equation for the molecular response time (τ{sub 0}) was derived for a vertical aligned cell and by solving an eigenvalue equation coming from the usual balance of torque equation in the Derzhanskii and Petrov formulation, recovering the usual equations in the appropriate limit. The results show that τ∼d{sup b}, where b=2 is observed only for strongly anchored cells, while for moderate to weak anchored cells, the exponent lies between 1 and 2, depending on both, surface viscosity and anchoring strength. We found that the surface viscosity is important when calculating the response time, specially for thin cells, critical for liquid crystal devices. The surface viscosity’s effect on the optical response time with pretilt is also explored. Our results bring new insights about the role of surface viscosity and its effects in applied physics. - Highlights: • The relaxation of nematic liquid crystals is calculated by taking the surface viscosity into account. • An analytical expression for the relaxation time depending on surface viscosity, anchoring strength and cell gap is obtained. • The results are numerically verified. • Surface viscosity is crucial for thin and weak anchored cells. • The effect on optical time and pretilt angle is also studied.

  4. State-of-the-art of liquid waste disposal for geothermal energy systems: 1979. Report PNL-2404

    SciTech Connect

    Defferding, L.J.

    1980-06-01

    The state-of-the-art of geothermal liquid waste disposal is reviewed and surface and subsurface disposal methods are evaluated with respect to technical, economic, legal, and environmental factors. Three disposal techniques are currently in use at numerous geothermal sites around the world: direct discharge into surface waters; deep-well injection; and ponding for evaporation. The review shows that effluents are directly discharged into surface waters at Wairakei, New Zealand; Larderello, Italy; and Ahuachapan, El Salvador. Ponding for evaporation is employed at Cerro Prieto, Mexico. Deep-well injection is being practiced at Larderello; Ahuachapan; Otake and Hatchobaru, Japan; and at The Geysers in California. All sites except Ahuachapan (which is injecting only 30% of total plant flow) have reported difficulties with their systems. Disposal techniques used in related industries are also reviewed. The oil industry's efforts at disposal of large quantities of liquid effluents have been quite successful as long as the effluents have been treated prior to injection. This study has determined that seven liquid disposal methods - four surface and three subsurface - are viable options for use in the geothermal energy industry. However, additional research and development is needed to reduce the uncertainties and to minimize the adverse environmental impacts of disposal. (MHR)

  5. Ultrafast dynamics of liquid water: Energy relaxation and transfer processes of the OH stretch and the HOH bend

    SciTech Connect

    Imoto, Sho; Xantheas, Sotiris S.; Saito, Shinji

    2015-08-27

    The vibrational energy relaxation and transfer processes of the OH stretching and the HOH bending vibrations in liquid water are investigated via the theoretical calculation of the pump-probe spectra obtained from non-equilibrium molecular dynamics simulations with the TTM3-F interaction potential. The excitation of the OH stretch induces an instantaneous response of the high frequency librational motions in the 600-1000 cm-1 range. In addition, the excess energy of the OH stretch of a water molecule quickly transfers to the OH stretches of molecules in its first hydration shell with a time constant of ~50 fs, followed by relaxation to the HOH bends of the surrounding molecules with a time constant of 230 fs. The excitation of the HOH bend also results in the ultrafast excitation of the high frequency librational motions. The energy of the excited HOH bend of a water molecule decays, with a time constant of 200 fs, mainly to the relaxation of the HOH bends of its surrounding molecules. The energies of the HOH bends were found to transfer quickly to the intermolecular motions via the coupling with the high frequency librational motions. The excess energy of the OH stretch or the HOH bend relaxes to the high frequency intermolecular librational motions and eventually to the hot ground state with a time scale of ~1 ps via the coupling with the librational and translational motions. The energy relaxation and transfer processes were found to depend on the local hydrogen bonding network; the relaxations of the excess energy of the OH stretch and the HOH bend of four- and five-coordinated molecules are faster than those of a three-coordinated molecule due to the delocalization of the vibrational motions of the former (four- and five-coordinated molecules) compared to those of the later (three-coordinated molecules). The present results highlight the importance of the high frequency intermolecular librational modes in facilitating the ultrafast energy relaxation process in

  6. Personnel carrier efficiency counts

    SciTech Connect

    Brezovec, D.

    1982-09-01

    Different types of personnel transport for underground mines are considered. In the US the majority are track vehicles powered by batteries or trolley lines. The safety aspects of trolley lines are discussed, together with the problems of track design. Rubber-tyred equipment is increasing in use: it is powered by batteries or diesel. Details of both types of carrier from a number of manufacturers are given in a Table. Bicycles and scooters which run on tracks are briefly mentioned, as well as the chairlift system used in Europe.

  7. Highly improved electroluminescence from a series of novel Eu(III) complexes with functional single-coordinate phosphine oxide ligands: tuning the intramolecular energy transfer, morphology, and carrier injection ability of the complexes.

    PubMed

    Xu, Hui; Yin, Kun; Huang, Wei

    2007-01-01

    The functional single-coordinate phosphine oxide ligands (4-diphenylaminophenyl)diphenylphosphine oxide (TAPO), (4-naphthalen-1-yl-phenylaminophenyl)diphenylphosphine oxide (NaDAPO), and 9-[4-(diphenylphosphinoyl)phenyl]-9H-carbazole (CPPO), as the direct combinations of hole-transporting moieties, and electron-transporting triphenylphosphine oxide (TPPO) were designed and synthesized (amines or carbazole), together with their Eu(III) complexes [Eu(tapo)(2)(tta)(3)] (1), [Eu(nadapo)(2)(tta)(3)] (2), and [Eu(cppo)(2)(tta)(3)] (3; TTA: 2-thenoyltrifluoroacetonate). The investigation indicated that by taking advantage of the modification inertia of the phosphine oxide ligands, the direct introduction of the hole-transport groups as chromophore made TAPO, NaDAPO, and CPPO obtain the most compact structure and mezzo S(1) and T(1) energy levels, which improved the intramolecular energy transfer in their Eu(III) complexes. The amorphous phase of 1-3 proved the weak intermolecular interaction, which resulted in extraordinarily low self-quenching of the complexes. The excellent double-carrier transport ability of the ligands was studied with Gaussian calculations, and the bipolar structure of TAPO and CPPO was proved. The great improvement of the double-carrier transport ability of 1-3 was shown by cyclic voltammetry. Their HOMO and LUMO energy levels of around 5.3 and 3.0 eV, respectively, are the best results for Eu(III) complexes reported so far. A single-layer organic light-emitting diode of 2 had the impressive brightness of 59 cd m(-2) which, to the best of our knowledge, is the highest reported so far. Both of the four-layer devices based on pure 1 and 2 had a maximum brightness of more than 1000 cd m(-2), turn-on voltages lower than 5 V, maximum external quantum yields of more than 3 % and excellent spectral stability. PMID:17918175

  8. Arsenic Removal by Liquid Membranes

    PubMed Central

    Marino, Tiziana; Figoli, Alberto

    2015-01-01

    Water contamination with harmful arsenic compounds represents one of the most serious calamities of the last two centuries. Natural occurrence of the toxic metal has been revealed recently for 21 countries worldwide; the risk of arsenic intoxication is particularly high in Bangladesh and India but recently also Europe is facing similar problem. Liquid membranes (LMs) look like a promising alternative to the existing removal processes, showing numerous advantages in terms of energy consumption, efficiency, selectivity, and operational costs. The development of different LM configurations has been a matter of investigation by several researching groups, especially for the removal of As(III) and As(V) from aqueous solutions. Most of these LM systems are based on the use of phosphine oxides as carriers, when the metal removal is from sulfuric acid media. Particularly promising for water treatment is the hollow fiber supported liquid membrane (HFSLM) configuration, which offers high selectivity, easy transport of the targeted metal ions, large surface area, and non-stop flow process. The choice of organic extractant(s) plays an essential role in the efficiency of the arsenic removal. Emulsion liquid membrane (ELM) systems have not been extensively investigated so far, although encouraging results have started to appear in the literature. For such LM configuration, the most relevant step toward efficiency is the choice of the surfactant type and its concentration. PMID:25826756

  9. Numerical determination of the interfacial energy and nucleation barrier of curved solid-liquid interfaces in binary systems.

    PubMed

    Kundin, Julia; Choudhary, Muhammad Ajmal

    2016-07-01

    The phase-field crystal (PFC) technique is a widely used approach for modeling crystal growth phenomena with atomistic resolution on mesoscopic time scales. We use a two-dimensional PFC model for a binary system based on the work of Elder et al. [Phys. Rev. B 75, 064107 (2007)PRBMDO1098-012110.1103/PhysRevB.75.064107] to study the effect of the curved, diffuse solid-liquid interface on the interfacial energy as well as the nucleation barrier. The calculation of the interfacial energy and the nucleation barrier certainly depends on the proper definition of the solid-liquid dividing surface and the corresponding nucleus size. We define the position of the sharp interface at which the interfacial energy is to be evaluated by using the concept of equimolar dividing surface (r^{e}) and the minimization of the interfacial energy (r^{s}). The comparison of the results based on both radii shows that the difference r^{e}-r^{s} is always positive and has a limit for large cluster sizes which is comparable to the Tolman length. Furthermore, we found the real nucleation barrier for small cluster sizes, which is defined as a function of the radius r^{s}, and compared it with the classical nucleation theory. The simulation results also show that the extracted interfacial energy as function of both radii is independent of system size, and this dependence can be reasonably described by the nonclassical Tolman formula with a positive Tolman length. PMID:27575196

  10. 19 CFR 158.4 - Liability of carrier for lost or missing packages.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... manifest and the quantity “permitted,” liquidated damages or duties shall be assessed under the provisions of the carrier's bond or under the provisions of section 448, Tariff Act of 1930, as amended (19...

  11. Liquid Sunshine to Fuel Your Car (A "Life at the Frontiers of Energy Research" contest entry from the 2011 Energy Frontier Research Centers (EFRCs) Summit and Forum)

    SciTech Connect

    Cosgrove, Daniel; CLSF Staff

    2011-05-01

    'Liquid Sunshine to Fuel Your Car' was submitted by the Center for Lignocellulose Structure and Formation (CLSF) to the 'Life at the Frontiers of Energy Research' video contest at the 2011 Science for Our Nation's Energy Future: Energy Frontier Research Centers (EFRCs) Summit and Forum. Twenty-six EFRCs created short videos to highlight their mission and their work. CLSF is directed by Daniel Cosgrove at Pennsylvania State University and is a partnership of scientists from three institutions: Penn State (lead), North Caroline State University, and Virginia Tech University. The Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science established the 46 Energy Frontier Research Centers (EFRCs) in 2009. These collaboratively-organized centers conduct fundamental research focused on 'grand challenges' and use-inspired 'basic research needs' recently identified in major strategic planning efforts by the scientific community. The overall purpose is to accelerate scientific progress toward meeting the nation's critical energy challenges. The mission of the Center for Lignocellulose Structure and Formation is 'to dramatically increase our fundamental knowledge of the formation and physical interactions of bio-polymer networks in plant cell walls to provide a basis for improved methods for converting biomass into fuels.' Research topics are: biofuels (biomass), membrane, interfacial characterization, matter by design, and self-assembly.

  12. Liquid Sunshine to Fuel Your Car (A "Life at the Frontiers of Energy Research" contest entry from the 2011 Energy Frontier Research Centers (EFRCs) Summit and Forum)

    ScienceCinema

    Cosgrove, Daniel (Director, Center for Lignocellulose Structure and Formation); CLSF Staff

    2011-11-02

    'Liquid Sunshine to Fuel Your Car' was submitted by the Center for Lignocellulose Structure and Formation (CLSF) to the 'Life at the Frontiers of Energy Research' video contest at the 2011 Science for Our Nation's Energy Future: Energy Frontier Research Centers (EFRCs) Summit and Forum. Twenty-six EFRCs created short videos to highlight their mission and their work. CLSF is directed by Daniel Cosgrove at Pennsylvania State University and is a partnership of scientists from three institutions: Penn State (lead), North Caroline State University, and Virginia Tech University. The Office of Basic Energy Sciences in the U.S. Department of Energy's Office of Science established the 46 Energy Frontier Research Centers (EFRCs) in 2009. These collaboratively-organized centers conduct fundamental research focused on 'grand challenges' and use-inspired 'basic research needs' recently identified in major strategic planning efforts by the scientific community. The overall purpose is to accelerate scientific progress toward meeting the nation's critical energy challenges. The mission of the Center for Lignocellulose Structure and Formation is 'to dramatically increase our fundamental knowledge of the formation and physical interactions of bio-polymer networks in plant cell walls to provide a basis for improved methods for converting biomass into fuels.' Research topics are: biofuels (biomass), membrane, interfacial characterization, matter by design, and self-assembly.

  13. Electron recombination in low-energy nuclear recoils tracks in liquid argon

    NASA Astrophysics Data System (ADS)

    Wojcik, M.

    2016-02-01

    This paper presents an analysis of electron-ion recombination processes in ionization tracks of recoiled atoms in liquid argon (LAr) detectors. The analysis is based on the results of computer simulations which use realistic models of electron transport and reactions. The calculations reproduce the recent experimental results of the ionization yield from 6.7 keV nuclear recoils in LAr. The statistical distribution of the number of electrons that escape recombination is found to deviate from the binomial distribution, and estimates of recombination fluctuations for nuclear recoils tracks are obtained. A study of the recombination kinetics shows that a significant part of electrons undergo very fast static recombination, an effect that may be responsible for the weak drift-field dependence of the ionization yield from nuclear recoils in some noble liquids. The obtained results can be useful in the search for hypothetical dark matter particles and in other studies that involve detection of recoiled nuclei.

  14. A discussion of the dispersion curve of energy excitations in liquid 4He

    NASA Astrophysics Data System (ADS)

    Bogoyavlenskii, I. V.; Puchkov, A. V.; Skomorokhov, A. N.; Karnatsevich, L. V.

    2004-10-01

    An investigation of the dispersion of excitations in a quantum liquid, superfluid 4He, is carried out. An attempt is made to systematize the published experimental data that indicate a substantially different nature of excitations with wave vectors corresponding to different parts of the dispersion curve of liquid 4He. Neutron spectroscopy data are analyzed in relation to a certain physical hypothesis concerning the formation of such a spectrum, and it is found that the majority of the known experimental facts can be explained in framework of that hypothesis. Particular attention is paid to a comparison of the experimental data obtained on the DIN-2PI time-of-flight spectrometer (at the IBR-2 Reactor, Dubna) with the results obtained at foreign research centers.

  15. Structural design of a high energy particle detector using liquid scintillator

    SciTech Connect

    Berg, Timothy John; /Minnesota U.

    1997-02-01

    This thesis presents a design for a 10,000 ton liquid scintillator neutrino detector being considered for the MINOS project at Fermilab. Details of designing, manufacturing, and assembling the active detector components are presented. The detector consists of 1080 magnetized steel absorber planes alternating with 1080 active detector planes. Each active plane is made up of plastic extrusions divided into nearly 400 cells for positional resolution. Life tests on the plastic extrusions determine their feasibility for containing the scintillator. The extrusions are sealed at the bottom, filled with liquid scintillator, and have an optical fiber running the entire length of each cell. The fibers terminate at the top of each extrusion in a manifold. An optical-fiber-light-guide connects the fibers in each manifold to a photo-detector. The photo-detector converts the light signals from the scintillator and optical fibers into electrical impulses for computer analysis.

  16. Structure, Energies, and Vibrational Frequencies of Solvated Li(+) in Ionic Liquids: Role of Cation Type.

    PubMed

    Dubnikova, Faina; Zeiri, Yehuda

    2016-05-19

    This study examines the structure of five ionic liquids all of them containing bis[(trifluoromethyl)sulfonyl]imide (TFSI) as the anion with five different cations: Dimethylammonium, N-propylammonium, N-methyl-1-propylpiperidinium, N-methyl-3-methylpyridinium, and N-methylpyrrolidinium. This study is based on quantum chemical calculations of structure, energetics, and vibrational spectroscopy associated with solutions of Li(+) in the five ionic liquids examined. We have shown that the Li-TFSI ion-pair stabilization is 2.5-4 fold larger than those of the ion pairs of five cations with TFSI. A large number of different species containing LikTFSInCtm (Ct represent one of five cations studied, k, n, m = 0-2) were examined in detail. The results suggest that Li-(TFSI)2 is a highly stable species and may be responsible for the transport of Li ions in these ionic liquids. The vibrational analysis suggests that the high stability of the Li-TFSI ion pair is mainly due to Coulomb interaction between the Li ion and two oxygen atoms bound to the two sulfur atoms in the TFSI anion. This O-Li-O bond exhibits stretching and bending modes that may allow monitoring of these ion pairs. PMID:26583198

  17. Temperature dependence of the crystal-liquid interfacial free energy and the endpoint of the melting line

    SciTech Connect

    Baidakov, Vladimir G. Protsenko, Sergey P.; Tipeev, Azat O.

    2013-12-14

    The crystal–liquid interfacial free energy γ has been calculated as a function of the crystal orientation in a molecular dynamics experiment in a system of Lennard-Jones (LJ) particles with a cutoff radius of the potential r{sub c}{sup *}=r{sub c}/σ=6.78 at a triple-point temperature T{sub t}{sup *}=k{sub B}T{sub t}/ε=0.692 and temperatures above (in the region of the stable coexistence of liquid and solid phases) and below (metastable continuation of the coexistence curve of liquid and solid phases) the temperature T{sub t}{sup *}. At T{sup *}=T{sub t}{sup *}, for determining γ use was made of the method of cleaving potential. The temperature dependence of γ on the crystal–liquid coexistence curve has been determined by the Gibbs-Cahn thermodynamic integration method. In the region of stable phase coexistence (T{sup *}>T{sub t}{sup *}) good agreement with the data of Davidchack and Laird [J. Chem. Phys. 118, 7651 (2003)] has been obtained with respect to the character of the temperature dependence of γ and the orientation anisotropy. In the region of metastable phase coexistence (T{sup *}energy decreases, approaching at T{sup *}=T{sub K}{sup *} the orientation-averaged value γ{sub 0K}{sup *}=γ{sub 0K}σ{sup 2}/ε=0.365. The paper discusses the behavior of the excess interfacial energy, excess interfacial entropy and excess interfacial stress on the metastable extension of the melting line and close to T{sup *}=T{sub K}{sup *}.

  18. Effect of surface anchoring energy on electro-optic characteristics of a fringe-field switching liquid crystal cell

    NASA Astrophysics Data System (ADS)

    Kim, Jin Hyun; Kang, Wan Seok; Sol Choi, Han; Park, Kiwoong; Lee, Joong Hee; Yoon, Sangho; Yoon, Sukin; Lee, Gi-Dong; Lee, Seung Hee

    2015-11-01

    Surface anchoring strength of the alignment layer on liquid crystal (LC) determines electro-optic characteristics in the LC devices. This paper investigates how azimuthal and polar anchoring strength affects the electro-optic performance of a fringe-field switching (FFS) mode associated with electrode structure, cell gap and dielectric anisotropy of the LC by numerical simulation. Our important findings in the FFS mode are that both azimuthal and polar anchoring energy can considerably affect the operating voltage and also maximum transmittance when using a LC with positive dielectric anisotropy; however, when using a LC with negative dielectric anisotropy only azimuthal anchoring energy affects electro-optic characteristics. The study proposes an optimal design of an alignment layer for maximizing transmittance in the FFS mode.

  19. Theoretical model applicable to the experimental determination of surface anchoring energies of nematic liquid crystals. M.S. Thesis

    NASA Technical Reports Server (NTRS)

    Wintucky, E. G.

    1980-01-01

    For a cell configuration consisting of a thin nematic layer bounded by two parallel plane surfaces, with opposing surfaces suitably treated to produce dissimilar molecular orientations, the elastic continuum theory for nematic liquid crystals was applied to derive an expression relating surface anchoring energies to elastic constants, director orientations at the substrate surfaces, and cell thickness. A numerical comparison with the elastically isotropic result over a range K sub 3 = 1.5 K sub 1 to K sub 3 = 10 K sub 1 showed the effect of elastic anisotropy could be quite significant. Surface anchoring energies calculated for anisotropic of K sub 3 = 2 K sub 1 and K sub 3 + 10 K sub 1 were approximately 50% and 500%, respectively, than the isotropic values.

  20. Wall-liquid and wall-crystal interfacial free energies via thermodynamic integration: a molecular dynamics simulation study.

    PubMed

    Benjamin, Ronald; Horbach, Jürgen

    2012-07-28

    A method is proposed to compute the interfacial free energy of a Lennard-Jones system in contact with a structured wall by molecular dynamics simulation. Both the bulk liquid and bulk face-centered-cubic crystal phase along the (111) orientation are considered. Our approach is based on a thermodynamic integration scheme where first the bulk Lennard-Jones system is reversibly transformed to a state where it interacts with a structureless flat wall. In a second step, the flat structureless wall is reversibly transformed into an atomistic wall with crystalline structure. The dependence of the interfacial free energy on various parameters such as the wall potential, the density and orientation of the wall is investigated. The conditions are indicated under which a Lennard-Jones crystal partially wets a flat wall. PMID:22852644

  1. Review of two-phase flow liquid metal MHD and turbine energy conversion concepts for space applications

    NASA Technical Reports Server (NTRS)

    Fabris, Gracio

    1992-01-01

    Two-phase energy conversion systems could be liquid metal magnetohydrodynamic (LMMHD) with no moving parts or two-phase turbines. Both of them are inherently simple and reliable devices which can operate in a wide range of temperatures. Their thermal efficiency is significantly higher than for conventional cycles due to reheat of vapor by liquid phase during the energy converting expansion. Often they can be more easily coupled to heat sources. These features make two-phase systems particularly promising for space application. Insufficient research has been done in the past. So far achieved LMMHD generator and two-phase turbine efficiencies are in the 40 to 45 percent range. However if certain fluid dynamic and design problems are resolved these efficiencies could be brought into the range of 70 percent. This would make two-phase systems extremely competitive as compared to present or other proposed conversion system for space. Accordingly, well directed research effort on potential space applications of two-phase conversion systems would be a wise investment.

  2. Review of two-phase flow liquid metal MHD and turbine energy conversion concepts for space applications

    NASA Astrophysics Data System (ADS)

    Fabris, Gracio

    Two-phase energy conversion systems could be liquid metal magnetohydrodynamic (LMMHD) with no moving parts or two-phase turbines. Both of them are inherently simple and reliable devices which can operate in a wide range of temperatures. Their thermal efficiency is significantly higher than for conventional cycles due to reheat of vapor by liquid phase during the energy converting expansion. Often they can be more easily coupled to heat sources. These features make two-phase systems particularly promising for space application. Insufficient research has been done in the past. So far achieved LMMHD generator and two-phase turbine efficiencies are in the 40 to 45 percent range. However if certain fluid dynamic and design problems are resolved these efficiencies could be brought into the range of 70 percent. This would make two-phase systems extremely competitive as compared to present or other proposed conversion system for space. Accordingly, well directed research effort on potential space applications of two-phase conversion systems would be a wise investment.

  3. A Systems View of the Differences between APOE ε4 Carriers and Non-carriers in Alzheimer's Disease.

    PubMed

    Jiang, Shan; Tang, Ling; Zhao, Na; Yang, Wanling; Qiu, Yu; Chen, Hong-Zhuan

    2016-01-01

    APOE ε4 is the strongest genetic risk factor for late-onset Alzheimer's disease (AD) and accounts for 50-65% of late-onset AD. Late-onset AD patients carrying or not carrying APOE ε4 manifest many clinico-pathological distinctions. Thus, we applied a weighted gene co-expression network analysis to identify specific co-expression modules in AD based on APOE ε4 stratification. Two specific modules were identified in AD APOE ε4 carriers and one module was identified in non-carriers. The hub genes of one module of AD APOE ε4 carriers were ISOC1, ENO3, GDF10, GNB3, XPO4, ACLY and MATN2. The other module of AD APOE ε4 carriers consisted of 10 hub genes including ANO3, ARPP21, HPCA, RASD2, PCP4 and ADORA2A. The module of AD APOE ε4 non-carriers consisted of 16 hub genes including DUSP5, TNFRSF18, ZNF331, DNAJB5 and RIN1. The module of AD APOE ε4 carriers including ISOC1 and ENO3 and the module of non-carriers contained the most highly connected hub gene clusters. mRNA expression of the genes in the cluster of the ISOC1 and ENO3 module of carriers was shown to be correlated in a time-dependent manner under APOE ε4 treatment but not under APOE ε3 treatment. In contrast, mRNA expression of the genes in the cluster of non-carriers' module was correlated under APOE ε3 treatment but not under APOE ε4 treatment. The modules of carriers demonstrated genetic bases and were mainly enriched in hereditary disorders and neurological diseases, energy metabolism-associated signaling and G protein-coupled receptor-associated pathways. The module including ISOC1 and ENO3 harbored two conserved promoter motifs in its hub gene cluster that could be regulated by common transcription factors and miRNAs. The module of non-carriers was mainly enriched in neurological, immunological and cardiovascular diseases and was correlated with Parkinson's disease. These data demonstrate that AD in APOE ε4 carriers involves more genetic factors and particular biological processes, whereas AD

  4. Vibrational energy relaxation of the ND-stretching vibration of NH2D in liquid NH3.

    PubMed

    Schäfer, Tim; Kandratsenka, Alexander; Vöhringer, Peter; Schroeder, Jörg; Schwarzer, Dirk

    2012-09-01

    The vibrational energy relaxation from the first excited ND-stretching mode of NH(2)D dissolved in liquid NH(3) is studied using molecular dynamics simulations. The rate constants for inter- and intramolecular energy transfer are calculated in the framework of the quantum-classical Landau-Teller theory. At 273 K and an ammonia density of 0.642 g cm(-3) the calculated ND-stretch lifetime of τ = 9.1 ps is in good agreement with the experimental value of 8.6 ps. The main relaxation channel accounting for 52% of the energy transfer involves an intramolecular transition to the first excited state of the umbrella mode. The energy difference between both states is taken up by the near-resonant bending vibrations of the solvent. Less important for the ND-stretch lifetime are both the direct transition to the ground state and intramolecular relaxation via the NH(2)D bending modes contributing 23% each. Our calculations imply that the experimentally observed weak density dependence of τ is caused by detuning the resonance between the ND-stretch-umbrella energy gap and the solvent accepting modes which counteracts the expected linear increase of the relaxation rate with density. PMID:22824981

  5. Telemetry carrier ring and support

    NASA Technical Reports Server (NTRS)

    Wakeman, Thomas G. (Inventor)

    1992-01-01

    A telemetry carrier ring for use in a gas turbine engine includes an annular support ring connected to the engine and an annular carrier ring coupled to the support ring, each ring exhibiting different growth characteristics in response to thermal and mechanical loading. The carrier ring is coupled to the support ring by a plurality of circumferentially spaced web members which are relatively thin in an engine radial direction to provide a predetermined degree of radial flexibility. the web members have a circumferential width and straight axial line of action selected to transfer torque and thrust between the support ring and the carrier ring without substantial deflection. The use of the web members with radial flexibility provides compensation between the support ring and the carrier ring since the carrier ring grows at a different rate than the supporting ring.

  6. Low Cost Chemical Feedstocks Using an Improved and Energy Efficient Natural Gas Liquid (NGL) Removal Process, Final Technical Report

    SciTech Connect

    Meyer, Howard, S.; Lu, Yingzhong

    2012-08-10

    The overall objective of this project is to develop a new low-cost and energy efficient Natural Gas Liquid (NGL) recovery process - through a combination of theoretical, bench-scale and pilot-scale testing - so that it could be offered to the natural gas industry for commercialization. The new process, known as the IROA process, is based on U.S. patent No. 6,553,784, which if commercialized, has the potential of achieving substantial energy savings compared to currently used cryogenic technology. When successfully developed, this technology will benefit the petrochemical industry, which uses NGL as feedstocks, and will also benefit other chemical industries that utilize gas-liquid separation and distillation under similar operating conditions. Specific goals and objectives of the overall program include: (i) collecting relevant physical property and Vapor Liquid Equilibrium (VLE) data for the design and evaluation of the new technology, (ii) solving critical R&D issues including the identification of suitable dehydration and NGL absorbing solvents, inhibiting corrosion, and specifying proper packing structure and materials, (iii) designing, construction and operation of bench and pilot-scale units to verify design performance, (iv) computer simulation of the process using commercial software simulation platforms such as Aspen-Plus and HYSYS, and (v) preparation of a commercialization plan and identification of industrial partners that are interested in utilizing the new technology. NGL is a collective term for C2+ hydrocarbons present in the natural gas. Historically, the commercial value of the separated NGL components has been greater than the thermal value of these liquids in the gas. The revenue derived from extracting NGLs is crucial to ensuring the overall profitability of the domestic natural gas production industry and therefore of ensuring a secure and reliable supply in the 48 contiguous states. However, rising natural gas prices have dramatically reduced

  7. A possible critical point for nematic order on the basis of Landau free energy having dual instabilities for nano-segregated smectic liquid crystals.

    PubMed

    Saito, Kazuya; Hishida, Mafumi; Yamamura, Yasuhisa

    2015-11-21

    Landau expansion of free energy assuming dual instabilities for the nano-segregated SmA phase is analyzed. In addition to known phase sequences (on cooling, disordered isotropic liquid → nematic phase → smectic phase, and disordered isotropic liquid → smectic phase), a new sequence (disordered isotropic liquid → density wave with subsidiary nematic order → smectic phase) and the existence of a critical point are demonstrated in the case where the instability for density wave formation occurs at a higher temperature. PMID:26372214

  8. Personnel emergency carrier vehicle

    NASA Technical Reports Server (NTRS)

    Owens, Lester J. (Inventor); Fedor, Otto H. (Inventor)

    1987-01-01

    A personnel emergency carrier vehicle is disclosed which includes a vehicle frame supported on steerable front wheels and driven rear wheels. A supply of breathing air is connected to quick connect face mask coupling and umbilical cord couplings for supplying breathing air to an injured worker or attendant either with or without a self-contained atmospheric protection suit for protection against hazardous gases at an accident site. A non-sparking hydraulic motion is utilized to drive the vehicle and suitable direction and throttling controls are provided for controlling the delivery of a hydraulic driving fluid from a pressurized hydraulic fluid accumulator. A steering axis is steerable through a handle to steer the front wheels through a linkage assembly.

  9. Solar energy storage via liquid filled cans - Test data and analysis

    NASA Technical Reports Server (NTRS)

    Saha, H.

    1978-01-01

    This paper describes the design of a solar thermal storage test facility with water-filled metal cans as heat storage medium and also presents some preliminary tests results and analysis. This combination of solid and liquid mediums shows unique heat transfer and heat contents characteristics and will be well suited for use with solar air systems for space and hot water heating. The trends of the test results acquired thus far are representative of the test bed characteristics while operating in the various modes.

  10. A membrane-free lithium/polysulfide semi-liquid battery for large-scale energy storage

    SciTech Connect

    Yang, Yuan; Zheng, Guangyuan; Cui, Yi

    2013-01-01

    Large-scale energy storage represents a key challenge for renewable energy and new systems with low cost, high energy density and long cycle life are desired. In this article, we develop a new lithium/polysulfide (Li/PS) semi-liquid battery for large-scale energy storage, with lithium polysulfide (Li{sub 2}S{sub 8}) in ether solvent as a catholyte and metallic lithium as an anode. Unlike previous work on Li/S batteries with discharge products such as solid state Li{sub 2}S{sub 2} and Li{sub 2}S, the catholyte is designed to cycle only in the range between sulfur and Li{sub 2}S{sub 4}. Consequently all detrimental effects due to the formation and volume expansion of solid Li{sub 2}S{sub 2}/Li{sub 2}S are avoided. This novel strategy results in excellent cycle life and compatibility with flow battery design. The proof-of-concept Li/PS battery could reach a high energy density of 170 W h kg{sup -1} and 190 W h L{sup -1} for large scale storage at the solubility limit, while keeping the advantages of hybrid flow batteries. We demonstrated that, with a 5 M Li{sub 2}S{sub 8} catholyte, energy densities of 97 W h kg{sup -1} and 108 W h L{sup -1} can be achieved. As the lithium surface is well passivated by LiNO{sub 3} additive in ether solvent, internal shuttle effect is largely eliminated and thus excellent performance over 2000 cycles is achieved with a constant capacity of 200 mA h g{sup -1}. This new system can operate without the expensive ion-selective membrane, and it is attractive for large-scale energy storage.

  11. Comparison of proton and neutron carrier removal rates

    SciTech Connect

    Pease, R.L.; Enlow, E.W.; Dinger, G.L.; Marshall, P.

    1987-12-01

    Displacement damage induced carrier removal rates for proton irradiations in the energy range 10-175 MeV were compared to 1 MeV equivalent neutrons using power MOSFETs as a test vehicle. The results showed that, within experimental error, the degradation mechanisms were qualitatively similar and the ratio of proton to neutron carrier removal rates as a function of proton energy correlate with a calculation based on nonionization energy loss in silicon. For exposures under junction bias, p-type silicon was found to have a smaller carrier removal rate for both proton and neutron irradiations, whereas, for n-type silicon, junction bias had little effect on the carrier removal rate.

  12. Plasmon-induced Hot Carriers in Metallic Nanoparticles

    NASA Astrophysics Data System (ADS)

    Liu, Jun; Manjavacas, Alejandro; Kulkarni, Vikram; Nordlander, Peter; LANP Team

    2015-03-01

    Plasmon-induced hot carrier formation is attracting an increasing research interest due to its potential for applications in photocatalysis, photodetection and solar energy harvesting. Here we develop a theoretical model for the plasmon-induced hot carrier process and apply it to spherical silver nanoparticles and nanoshells. We show that the inclusion of many-body interactions has only a minor influence on the results. Using the model we calculate the rate of hot carrier generation, finding that it closely follows the spectral profile of the plasmon. Our analysis reveals that particle size and hot carrier lifetime play a central role in determining both the production rate and the energy distribution of the hot carriers. We characterize the efficiency of the hot carrier generation process by introducing a figure of merit that measures the number of high energy carriers generated per plasmon. Furthermore, we analyze the spatial distribution and directionality of these excitations. A. M. acknowledges financial support from the Welch foundation through the J. Evans Attwell-Welch Postdoctoral Fellowship Program of the Smalley Institute of Rice University (Grant No. L-C-004).

  13. Role of the Liquids From Coal process in the world energy picture

    SciTech Connect

    Frederick, J.P.; Knottnerus, B.A.

    1997-12-31

    ENCOAL Corporation, a wholly owned indirect subsidiary of Zeigler Coal Holding Company, has essentially completed the demonstration phase of a 1,000 Tons per day (TPD) Liquids From Coal (LFC{trademark}) plant near Gillette, Wyoming. The plant has been in operation for 4{1/2} years and has delivered 15 unit trains of Process Derived Fuel (PDF{trademark}), the low-sulfur, high-Btu solid product to five major utilities. Recent test burns have indicated the PDF{trademark} can offer the following benefits to utility customers: lower sulfur emissions, lower NO{sub x} emissions, lower utilized fuel costs to power plants, and long term stable fuel supply. More than three million gallons of Coal Derived Liquid (CDL{trademark}) have also been delivered to seven industrial fuel users and one steel mill blast furnace. Additionally, laboratory characteristics of CDL{trademark} and process development efforts have indicated that CDL{trademark} can be readily upgraded into higher value chemical feedstocks and transportation fuels. Commercialization of the LFC{trademark} is also progressing. Permit work for a large scale commercial ENCOAL{reg_sign} plant in Wyoming is now underway and domestic and international commercialization activity is in progress by TEK-KOL, a general partnership between SGI International and a Zeigler subsidiary. This paper covers the historical background of the project, describes the LFC{trademark} process and describes the worldwide outlook for commercialization.

  14. Monitoring method and apparatus using high-frequency carrier

    DOEpatents

    Haynes, H.D.

    1996-04-30

    A method and apparatus for monitoring an electrical-motor-driven device by injecting a high frequency carrier signal onto the power line current. The method is accomplished by injecting a high frequency carrier signal onto an AC power line current. The AC power line current supplies the electrical-motor-driven device with electrical energy. As a result, electrical and mechanical characteristics of the electrical-motor-driven device modulate the high frequency carrier signal and the AC power line current. The high frequency carrier signal is then monitored, conditioned and demodulated. Finally, the modulated high frequency carrier signal is analyzed to ascertain the operating condition of the electrical-motor-driven device. 6 figs.

  15. Monitoring method and apparatus using high-frequency carrier

    DOEpatents

    Haynes, Howard D.

    1996-01-01

    A method and apparatus for monitoring an electrical-motor-driven device by injecting a high frequency carrier signal onto the power line current. The method is accomplished by injecting a high frequency carrier signal onto an AC power line current. The AC power line current supplies the electrical-motor-driven device with electrical energy. As a result, electrical and mechanical characteristics of the electrical-motor-driven device modulate the high frequency carrier signal and the AC power line current. The high frequency carrier signal is then monitored, conditioned and demodulated. Finally, the modulated high frequency carrier signal is analyzed to ascertain the operating condition of the electrical-motor-driven device.

  16. Fundamental limitations of hot-carrier solar cells

    NASA Astrophysics Data System (ADS)

    Kirk, A. P.; Fischetti, M. V.

    2012-10-01

    Sunlight-generated hot-carrier transport in strongly absorbing direct band-gap GaAs—among the most optimal of semiconductors for high-efficiency solar cells—is simulated with an accurate full-band structure self-consistent Monte Carlo method, including short- and long-range Coulomb interaction, impact ionization, and optical and acoustic phonon scattering. We consider an ultrapure 100-nm-thick intrinsic GaAs absorber layer designed with quasiballistic carrier transport that achieves complete photon absorption down to the band edge by application of careful light trapping and that has a generous hot-carrier retention time of 10 ps prior to the onset of carrier relaxation. We find that hot-carrier solar cells can be severely limited in performance due to the substantially reduced current density caused by insufficient extraction of the widely distributed hot electrons (holes) through the requisite energy selective contacts.

  17. Carrier dynamics in femtosecond-laser-excited bismuth telluride

    NASA Astrophysics Data System (ADS)

    Wang, J. L.; Guo, L.; Ling, C.; Song, Y. M.; Xu, X. F.; Ni, Z. H.; Chen, Y. F.

    2016-04-01

    The carrier dynamics of B i2T e3 is studied using the femtosecond pump-probe technique. Three distinct processes, including free carrier absorption, band filling, and electron-hole recombination, are found to contribute to the reflectivity changes. The two-temperature model is used to describe the intraband energy relaxation process of carriers, and the Drude contribution well explains the intensity dependence of the peak values of the nonoscillatory component in the reflectivity signal. The combined effects of free carrier absorption and band filling result in a reflection minimum at about 2 ps after laser excitation. The nonzero background signal increases linearly with the pump fluence, which is attributed to the electron-hole recombination. Finally, our results provide an illustration of investigating the carrier dynamics in semiconductors from the ultrafast reflectivity spectra.

  18. Managing photons and carriers for photocatalysis

    NASA Astrophysics Data System (ADS)

    Thomann, Isabell; Robatjazi, Hossein; Bahauddin, Shah; Doiron, Chloe; Liu, Xuejun; Tumkur, Thejaswi; Wang, Wei-Ren; Wray, Parker

    While small plasmonic nanoparticles efficiently generate energetic hot carriers, light absorption in a monolayer of such particles is inefficient, and practical utilization of the hot carriers in addition requires efficient charge-separation. Here we describe our approach to address both challenges. By designing an optical cavity structure for the plasmonic photoelectrode, light absorption in these particles can be significantly enhanced, resulting in efficient hot electron generation. Rather than utilizing a Schottky barrier to preserve the energy of the carriers, our structure allows for their direct injection into the adjacent electrolyte. On the substrate side, the plasmonic particles are in contact with a wide band gap oxide film that serves as an electron blocking layer but accepts holes and transfers them to the counter electrode. The observed photocurrent spectra follow the plasmon spectrum, and demonstrate that the extracted electrons are energetic enough to drive the hydrogen evolution reaction. A similar structure can be designed to achieve broadband absorption enhancement in monolayer MoS2. Time permitting, I will discuss charge carrier dynamics in hybrid nanoparticles composed of plasmonic / two-dimensional materials, and applications of photo-induced force microscopy to study photocatalytic processes.

  19. A highly shape-adaptive, stretchable design based on conductive liquid for energy harvesting and self-powered biomechanical monitoring

    PubMed Central

    Yi, Fang; Wang, Xiaofeng; Niu, Simiao; Li, Shengming; Yin, Yajiang; Dai, Keren; Zhang, Guangjie; Lin, Long; Wen, Zhen; Guo, Hengyu; Wang, Jie; Yeh, Min-Hsin; Zi, Yunlong; Liao, Qingliang; You, Zheng; Zhang, Yue; Wang, Zhong Lin

    2016-01-01

    The rapid growth of deformable and stretchable electronics calls for a deformable and stretchable power source. We report a scalable approach for energy harvesters and self-powered sensors that can be highly deformable and stretchable. With conductive liquid contained in a polymer cover, a shape-adaptive triboelectric nanogenerator (saTENG) unit can effectively harvest energy in various working modes. The saTENG can maintain its performance under a strain of as large as 300%. The saTENG is so flexible that it can be conformed to any three-dimensional and curvilinear surface. We demonstrate applications of the saTENG as a wearable power source and self-powered sensor to monitor biomechanical motion. A bracelet-like saTENG worn on the wrist can light up more than 80 light-emitting diodes. Owing to the highly scalable manufacturing process, the saTENG can be easily applied for large-area energy harvesting. In addition, the saTENG can be extended to extract energy from mechanical motion using flowing water as the electrode. This approach provides a new prospect for deformable and stretchable power sources, as well as self-powered sensors, and has potential applications in various areas such as robotics, biomechanics, physiology, kinesiology, and entertainment. PMID:27386560

  20. A Bio-Inspired, Heavy-Metal-Free, Dual-Electrolyte Liquid Battery towards Sustainable Energy Storage.

    PubMed

    Ding, Yu; Yu, Guihua

    2016-04-01

    Wide-scale exploitation of renewable energy requires low-cost efficient energy storage devices. The use of metal-free, inexpensive redox-active organic materials represents a promising direction for environmental-friendly, cost-effective sustainable energy storage. To this end, a liquid battery is designed using hydroquinone (H2 BQ) aqueous solution as catholyte and graphite in aprotic electrolyte as anode. The working potential can reach 3.4 V, with specific capacity of 395 mA h g(-1) and stable capacity retention about 99.7 % per cycle. Such high potential and capacity is achieved using only C, H and O atoms as building blocks for redox species, and the replacement of Li metal with graphite anode can circumvent potential safety issues. As H2 BQ can be extracted from biomass directly and its redox reaction mimics the bio-electrochemical process of quinones in nature, using such a bio-inspired organic compound in batteries enables access to greener and more sustainable energy-storage technology. PMID:26958787

  1. A highly shape-adaptive, stretchable design based on conductive liquid for energy harvesting and self-powered biomechanical monitoring.

    PubMed

    Yi, Fang; Wang, Xiaofeng; Niu, Simiao; Li, Shengming; Yin, Yajiang; Dai, Keren; Zhang, Guangjie; Lin, Long; Wen, Zhen; Guo, Hengyu; Wang, Jie; Yeh, Min-Hsin; Zi, Yunlong; Liao, Qingliang; You, Zheng; Zhang, Yue; Wang, Zhong Lin

    2016-06-01

    The rapid growth of deformable and stretchable electronics calls for a deformable and stretchable power source. We report a scalable approach for energy harvesters and self-powered sensors that can be highly deformable and stretchable. With conductive liquid contained in a polymer cover, a shape-adaptive triboelectric nanogenerator (saTENG) unit can effectively harvest energy in various working modes. The saTENG can maintain its performance under a strain of as large as 300%. The saTENG is so flexible that it can be conformed to any three-dimensional and curvilinear surface. We demonstrate applications of the saTENG as a wearable power source and self-powered sensor to monitor biomechanical motion. A bracelet-like saTENG worn on the wrist can light up more than 80 light-emitting diodes. Owing to the highly scalable manufacturing process, the saTENG can be easily applied for large-area energy harvesting. In addition, the saTENG can be extended to extract energy from mechanical motion using flowing water as the electrode. This approach provides a new prospect for deformable and stretchable power sources, as well as self-powered sensors, and has potential applications in various areas such as robotics, biomechanics, physiology, kinesiology, and entertainment. PMID:27386560

  2. A Systems View of the Differences between APOE ε4 Carriers and Non-carriers in Alzheimer’s Disease

    PubMed Central

    Jiang, Shan; Tang, Ling; Zhao, Na; Yang, Wanling; Qiu, Yu; Chen, Hong-Zhuan

    2016-01-01

    APOE ε4 is the strongest genetic risk factor for late-onset Alzheimer’s disease (AD) and accounts for 50–65% of late-onset AD. Late-onset AD patients carrying or not carrying APOE ε4 manifest many clinico-pathological distinctions. Thus, we applied a weighted gene co-expression network analysis to identify specific co-expression modules in AD based on APOE ε4 stratification. Two specific modules were identified in AD APOE ε4 carriers and one module was identified in non-carriers. The hub genes of one module of AD APOE ε4 carriers were ISOC1, ENO3, GDF10, GNB3, XPO4, ACLY and MATN2. The other module of AD APOE ε4 carriers consisted of 10 hub genes including ANO3, ARPP21, HPCA, RASD2, PCP4 and ADORA2A. The module of AD APOE ε4 non-carriers consisted of 16 hub genes including DUSP5, TNFRSF18, ZNF331, DNAJB5 and RIN1. The module of AD APOE ε4 carriers including ISOC1 and ENO3 and the module of non-carriers contained the most highly connected hub gene clusters. mRNA expression of the genes in the cluster of the ISOC1 and ENO3 module of carriers was shown to be correlated in a time-dependent manner under APOE ε4 treatment but not under APOE ε3 treatment. In contrast, mRNA expression of the genes in the cluster of non-carriers’ module was correlated under APOE ε3 treatment but not under APOE ε4 treatment. The modules of carriers demonstrated genetic bases and were mainly enriched in hereditary disorders and neurological diseases, energy metabolism-associated signaling and G protein-coupled receptor-associated pathways. The module including ISOC1 and ENO3 harbored two conserved promoter motifs in its hub gene cluster that could be regulated by common transcription factors and miRNAs. The module of non-carriers was mainly enriched in neurological, immunological and cardiovascular diseases and was correlated with Parkinson’s disease. These data demonstrate that AD in APOE ε4 carriers involves more genetic factors and particular biological processes

  3. Non-Fermi liquids in two and three-dimensional doped SrTiO3

    NASA Astrophysics Data System (ADS)

    Mikheev, Evgeny; Raghavan, Santosh; Zhang, Jack; Marshall, Patrick; Kajdos, Adam; Balents, Leon; Stemmer, Susanne

    A remarkable feature of transport in doped SrTiO3 is the temperature dependence of the electrical resistivity that is proportional to Tn with n <= 2. This power law suggests electron-electron scattering is the dominant scattering mechanism. It extends to room temperature and above in both three-dimensional, uniformly doped SrTiO3 and in two-dimensional electron liquids (2DELs) at oxide interfaces. In case of n = 2, the behavior is traditionally identified as that of a Landau Fermi liquid. Here we argue that Landau Fermi liquid theory does not apply to the electron liquid in SrTiO3, even when n = 2. Using electrostatic gating and chemical doping, we demonstrate that this regime is associated with a scattering rate and an energy scale that are independent of carrier density. This is in fundamental conflict with the premise of the Fermi liquid theory, where this energy scale is the Fermi energy. This work raises important questions in terms of microscopic scattering mechanism. It appears to be relevant for understanding of transport in many other strongly correlated systems, which also show very robust Tn regimes with carrier density independent scattering rates.

  4. Method of recovering adsorbed liquid compounds from molecular sieve columns

    DOEpatents

    Burkholder, Harvey R.; Fanslow, Glenn E.

    1983-01-01

    Molecularly adsorbed volatile liquid compounds are recovered from molecular sieve adsorbent columns by directionally applying microwave energy to the bed of the adsorbent to produce a mixed liquid-gas effluent. The gas portion of the effluent generates pressure within the bed to promote the discharge of the effluent from the column bottoms. Preferably the discharged liquid-gas effluent is collected in two to three separate fractions, the second or intermediate fraction having a substantially higher concentration of the desorbed compound than the first or third fractions. The desorption does not need to be assisted by passing a carrier gas through the bed or by applying reduced pressure to the outlet from the bed.

  5. Method of recovering adsorbed liquid compounds from molecular sieve columns

    DOEpatents

    Burkholder, H.R.; Fanslow, G.E.

    1983-12-20

    Molecularly adsorbed volatile liquid compounds are recovered from molecular sieve adsorbent columns by directionally applying microwave energy to the bed of the adsorbent to produce a mixed liquid-gas effluent. The gas portion of the effluent generates pressure within the bed to promote the discharge of the effluent from the column bottoms. Preferably the discharged liquid-gas effluent is collected in two to three separate fractions, the second or intermediate fraction having a substantially higher concentration of the desorbed compound than the first or third fractions. The desorption does not need to be assisted by passing a carrier gas through the bed or by applying reduced pressure to the outlet from the bed. 8 figs.

  6. Experimental analysis of general ion recombination in a liquid-filled ionization chamber in high-energy photon beams

    SciTech Connect

    Chung, Eunah; Seuntjens, Jan; Davis, Stephen

    2013-06-15

    Purpose: To study experimentally the general ion recombination effect in a liquid-filled ionization chamber (LIC) in high-energy photon beams. Methods: The general ion recombination effect on the response of a micro liquid ion chamber (microLion) was investigated with a 6 MV photon beam in normal and SRS modes produced from a Varian{sup Registered-Sign} Novalis Tx{sup TM} linear accelerator. Dose rates of the linear accelerator were set to 100, 400, and 1000 MU/min, which correspond to pulse repetition frequencies of 60, 240, and 600 Hz, respectively. Polarization voltages applied to the microLion were +800 and +400 V. The relative collection efficiency of the microLion response as a function of dose per pulse was experimentally measured with changing polarization voltage and pulse repetition frequencies and was compared with the theoretically calculated value. Results: For the 60 Hz pulse repetition frequency, the experimental relative collection efficiency was not different from the theoretical one for a pulsed beam more than 0.3% for both polarization voltages. For a pulsed radiation beam with a higher pulse repetition frequency, the experimental relative collection efficiency converged to the theoretically calculated efficiency for continuous beams. This result indicates that the response of the microLion tends toward the response to a continuous beam with increasing pulse repetition frequency of a pulsed beam because of low ion mobility in the liquid. Conclusions: This work suggests an empirical method to correct for differences in general ion recombination of a LIC between different radiation fields. More work is needed to quantitatively explain the LIC general ion recombination behavior in pulsed beams generated from linear accelerators.

  7. Measurement of the Charge and Light Yield of Low Energy Electronic and Nuclear Recoils in Liquid Xenon at Different Electric Fields

    NASA Astrophysics Data System (ADS)

    Anthony, Matthew; Aprile, Elena; Contreras, Hugo; Goetzke, Luke; Melgarejo, Antonio; Plante, Guillaume; Weber, Marc

    2015-04-01

    Liquid xenon detectors continue to lead in the search for the direct detection of dark matter. Still, very few measurements have studied the response of liquid xenon to low-energy interactions (<= 10 keV) at different applied electric fields. The neriX detector at Columbia University is a dual-phase time projection chamber that is optimized for simultaneous measurements of light and charge from these low-energy interactions. Coincidence techniques are employed to extract the light and charge yields from electronic and nuclear recoils in liquid xenon as a function of energy deposited and applied electric field. In this talk, we will discuss the results of the charge and light yield measurements. We acknowledge continued support of the XENON Dark Matter program at Columbia University by the National Science Foundation.

  8. A decoupled energy stable scheme for a hydrodynamic phase-field model of mixtures of nematic liquid crystals and viscous fluids

    NASA Astrophysics Data System (ADS)

    Zhao, Jia; Yang, Xiaofeng; Shen, Jie; Wang, Qi

    2016-01-01

    We develop a linear, first-order, decoupled, energy-stable scheme for a binary hydrodynamic phase field model of mixtures of nematic liquid crystals and viscous fluids that satisfies an energy dissipation law. We show that the semi-discrete scheme in time satisfies an analogous, semi-discrete energy-dissipation law for any time-step and is therefore unconditionally stable. We then discretize the spatial operators in the scheme by a finite-difference method and implement the fully discrete scheme in a simplified version using CUDA on GPUs in 3 dimensions in space and time. Two numerical examples for rupture of nematic liquid crystal filaments immersed in a viscous fluid matrix are given, illustrating the effectiveness of this new scheme in resolving complex interfacial phenomena in free surface flows of nematic liquid crystals.

  9. {alpha}-decay energy formula for superheavy nuclei based on the liquid-drop model

    SciTech Connect

    Dong Tiekuang; Ren Zhongzhou

    2010-09-15

    A formula of {alpha}-decay energy for superheavy nuclei based on the method of macroscopic model plus shell corrections is proposed. The macroscopic part of this formula is derived from the Bethe-Weizsaecker binding energy formula, and the shell corrections at N=152 and N=162 are expressed by the Mexican hat wavelet functions. The parameters of this formula are obtained through fitting to 170 {alpha}-decay energies for nuclei ranging from Z=90 to Z=118 with N{>=}140. Numerical results show that 170 existing {alpha}-decay energies can be reproduced very well; the average and standard deviations between theoretical results and experimental data are 0.177 and 0.226 MeV, respectively. The {alpha}-decay energies of newly synthesized nuclei {sup 293,294}117 and their {alpha}-decay products are also reproduced very well. In addition, the {alpha}-decay energies for nuclei with Z=110-120 are predicted and compared with the results calculated by the macroscopic-microscopic model. Great differences are found for nuclei with Z{>=}116 and N{>=}176 due to the shell effects near the hypothetical doubly magic nucleus {sup 298}114{sub 184} in the macroscopic-microscopic model. Therefore, by comparing experimental {alpha}-decay energies measured in the future with the ones predicted by these two methods, one can obtain useful information about the next proton and neutron magic numbers.

  10. Energy storage capacity of reversible liquid phase Diels-Alder reactions as determined by drop calorimetry

    SciTech Connect

    Chung, C.P.

    1983-01-01

    Several Diels-Alder reactions were evaluated as possible candidates for energy storage. The goal was to use simple drop calorimetry to screen reactions and to identify those with high energy storage capacities. The dienes used were furan and substituted furans. The dienophiles used were maleic anhydride and substituted maleic anhydrides. Sixteen reactions have been examined. Three had energy storage capacities that were increased due to reaction (maleic anhydride and 2-methyl furan, maleic anhydride and 2-ethyl furan, maleic anhydride and 2,5-dimethyl furan). The remaining thirteen showed no increase in apparent heat capacity due to reaction.

  11. Concentrated solar energy for thermochemically producing liquid fuels from CO2 and H2O

    NASA Astrophysics Data System (ADS)

    Loutzenhiser, Peter G.; Stamatiou, Anastasia; Villasmil, Willy; Meier, Anton; Steinfeld, Aldo

    2011-01-01

    A two-step solar thermochemical cycle for producing syngas from H2O and CO2 via Zn/ZnO redox reactions is considered. The first, endothermic step is the thermolysis of ZnO to Zn and O2 using concentrated solar radiation as the source of process heat. The second, non-solar, exothermic step is the reaction of Zn with mixtures of H2O and CO2 yielding high-quality syngas (mainly H2 and CO) and ZnO; the latter is recycled to the first solar step, resulting in net reactions CO2 = CO+0.5O2 and H2O= H2 +0.5O2. Syngas is further processed to liquid fuels via Fischer-Tropsch or other catalytic reforming processes. State-of-the-art reactor technologies and experimental results are provided for both steps of the cycle.

  12. Thermodynamics of a Fermi Liquid beyond the Low-Energy Limit

    NASA Astrophysics Data System (ADS)

    Chubukov, Andrey V.; Maslov, Dmitrii L.; Gangadharaiah, Suhas; Glazman, Leonid I.

    2005-07-01

    We consider the nonanalytic temperature dependences of the specific heat coefficient, C(T)/T, and spin susceptibility, χs(T), of 2D interacting fermions beyond the weak-coupling limit. We demonstrate within the Luttinger-Ward formalism that the leading temperature dependences of C(T)/T and χs(T) are linear in T, and are described by the Fermi liquid theory. We show that these temperature dependences are universally determined by the states near the Fermi level and, for a generic interaction, are expressed via the spin and charge components of the exact backscattering amplitude of quasiparticles. We compare our theory to recent experiments on monolayers of He3.

  13. On the interplay of the potential energy and dipole moment surfaces in controlling the infrared activity of liquid water

    NASA Astrophysics Data System (ADS)

    Medders, Gregory R.; Paesani, Francesco

    2015-06-01

    Infrared vibrational spectroscopy is a valuable tool for probing molecular structure and dynamics. However, obtaining an unambiguous molecular-level interpretation of the spectral features is made difficult, in part, due to the complex interplay of the dipole moment with the underlying vibrational structure. Here, we disentangle the contributions of the potential energy surface (PES) and dipole moment surface (DMS) to the infrared spectrum of liquid water by examining three classes of models, ranging in complexity from simple point charge models to accurate representations of the many-body interactions. By decoupling the PES from the DMS in the calculation of the infrared spectra, we demonstrate that the PES, by directly modulating the vibrational structure, primarily controls the width and position of the spectroscopic features. Due to the dependence of the molecular dipole moment on the hydration environment, many-body electrostatic effects result in a ˜100 cm-1 redshift in the peak of the OH stretch band. Interestingly, while an accurate description of many-body collective motion is required to generate the correct (vibrational) structure of the liquid, the infrared intensity in the OH stretching region appears to be a measure of the local structure due to the dominance of the one-body and short-ranged two-body contributions to the total dipole moment.

  14. Impact of crop-manure ratios on energy production and fertilizing characteristics of liquid and solid digestate during codigestion.

    PubMed

    Pabón-Pereira, C P; de Vries, J W; Slingerland, M A; Zeeman, G; van Lier, J B

    2014-01-01

    The influence of maize silage-manure ratios on energy output and digestate characteristics was studied using batch experiments. The methane production, nutrients availability (N and P) and heavy metals' content were followed in multiflask experiments at digestion times 7, 14, 20, 30 and 60 days. In addition, the available nutrient content in the liquid and solid parts of the digestate was evaluated. Aanaerobic digestion favoured the availability of nutrients to plants, after 61 days 20-26% increase in NH4+ and 0-36% increase in PO4(3-) were found in relation to initial concentrations. Digestion time and maize addition increased the availability of PO4(3-). Inorganic nutrients were found to be mainly available in the liquid part of the digestate, i.e. 80-92% NH4+ and 65-74% PO4(3-). Manure had a positive effect on the methane production rate, whereas maize silage increased the total methane production per unit volatile solids in all treatments. PMID:25145197

  15. Liquid-Metal Electrode to Enable Ultra-Low Temperature Sodium-Beta Alumina Batteries for Renewable Energy Storage

    SciTech Connect

    Lu, Xiaochuan; Li, Guosheng; Kim, Jin Yong; Mei, Donghai; Lemmon, John P.; Sprenkle, Vincent L.; Liu, Jun

    2014-08-01

    Metal electrodes have a high capacity for energy storage but have found limited applications in batteries because of dendrite formation and other problems. In this paper, we report a new alloying strategy that can significantly reduce the melting temperature and improve wetting with the electrolyte to allow the use of liquid metal as anode in sodium-beta alumina batteries (NBBs) at much lower temperatures (e.g., 95 to 175°C). Commercial NBBs such as sodium-sulfur (Na-S) battery and sodium-metal halide (ZEBRA) batteries typically operate at relatively high temperatures (e.g., 300-350°C) due to poor wettability of sodium on the surface of β"-Al2O3. Our combined experimental and computational studies suggest that Na-Cs alloy can replace pure sodium as the anode material, which provides a significant improvement in wettability, particularly at lower temperatures (i.e., <200°C). Single cells with the Na-Cs alloy anode exhibit excellent cycling life over those with pure sodium anode at 175 and 150°C. The cells can even operate at 95°C, which is below the melting temperature of pure sodium. These results demonstrate that NBB can be operated at ultra lower temperatures with successfully solving the wetting issue. This work also suggests a new strategy to use liquid metal as the electrode materials for advanced batteries that can avoid the intrinsic safety issues associated with dendrite formation on the anode.

  16. Investigation on the Arc Ignition Characteristics and Energy Absorption of Liquid Metal Current Limiter Based on Self-Pinch Effect

    NASA Astrophysics Data System (ADS)

    Ju, Xingbao; Sun, Haishun; Yang, Zhuo; Zhang, Junmin

    2016-05-01

    The GaInSn liquid metal current limiter based on the fluid pinch effect has broad application prospects due to its particular properties. However, the limited rated current and ability of power dissipation are the critical problems for its wide application. Firstly, the temperature distribution of the liquid metal current limiter (LMCL) was obtained by experiments with a rated current of 1 kA and the arc ignition phenomenon was observed with 1.5 kA, which indicates that the rated current is mainly limited by the arc rather than the high temperature compared to the traditional switchgears. Furthermore, an improved method is proposed by adding the paralleled pure resistance, impedance or another LMCL element to protect the setup from the fault energy concentration in the setup. The problem of a slower arc voltage increasing rate can be solved by adding a paralleled impedance with suitable parameters. Finally, the current limiting properties based on the improved method were investigated and the alternating oscillating current was found between two paralleled LMCL elements owing to their deviation of arc ignition in reality. supported by the Technology Project of State Grid (No. SGSNKYOOKJJS1501564) and the National Key Basic Research Program of China (973 Program) (No. 2015CB251005)

  17. Calculating the role of composition in the anisotropy of solid-liquid interface energy using phase-field-crystal theory

    NASA Astrophysics Data System (ADS)

    Jugdutt, Bernadine A.; Ofori-Opoku, Nana; Provatas, Nikolas

    2015-10-01

    This work uses Ginzburg-Landau theory derived from a recent structural phase-field-crystal model of binary alloys developed by the authors to study the roles of concentration, temperature, and pressure on the interfacial energy anisotropy of a solid-liquid front. It is found that the main contribution to the change in anisotropy with concentration arises from a change in preferred crystallographic orientation controlled by solute-dependent changes in the two-point density correlation function of a binary alloy, a mechanism that leads to such phenomena as solute-induced elastic strain and dislocation-assisted solute clustering. Our results are consistent with experimental observations in recent studies by Rappaz et al. [J. Fife, P. Di Napoli, and M. Rappaz, Metall. Mater. Trans. A 44, 5522 (2013), 10.1007/s11661-013-1912-7]. This is the first PFC work, to our knowledge, to incorporate temperature, pressure, and density into the thermodynamic description of alloys.

  18. Calculating the role of composition in the anisotropy of solid-liquid interface energy using phase-field-crystal theory.

    PubMed

    Jugdutt, Bernadine A; Ofori-Opoku, Nana; Provatas, Nikolas

    2015-10-01

    This work uses Ginzburg-Landau theory derived from a recent structural phase-field-crystal model of binary alloys developed by the authors to study the roles of concentration, temperature, and pressure on the interfacial energy anisotropy of a solid-liquid front. It is found that the main contribution to the change in anisotropy with concentration arises from a change in preferred crystallographic orientation controlled by solute-dependent changes in the two-point density correlation function of a binary alloy, a mechanism that leads to such phenomena as solute-induced elastic strain and dislocation-assisted solute clustering. Our results are consistent with experimental observations in recent studies by Rappaz et al. [J. Fife, P. Di Napoli, and M. Rappaz, Metall. Mater. Trans. A 44, 5522 (2013)]. This is the first PFC work, to our knowledge, to incorporate temperature, pressure, and density into the thermodynamic description of alloys. PMID:26565255

  19. Effects of Dilution, Polarization Ratio, and Energy Transfer on Photoalignment of Liquid Crystals Using Coumarin-Containing Polymer Films

    SciTech Connect

    Kim, C.; Wallace, J.U.; Chen, S.H.; Merkel, P.B.

    2008-05-27

    Orientation of a nematic liquid crystal, E-7, was investigated using coumarin-containing polymethacrylates to elucidate the roles played by the dilution of coumarin and the polarization ratio of irradiation. Dilution of coumarin by inert moieties had adverse effects on a nematic cell’s number density of disclinations and its orientational order parameter in the parallel but not the perpendicular regime. In addition, both dilution of coumarin and a decreasing polarization ratio resulted in a lower extent of coumarin dimerization at crossover, Xc. The significantly reduced Xc in a homopolymer comprising triphenylamine and coumarin was attributed to the dilution of coumarin and the diminished polarization ratio caused by competing absorption with simultaneous triplet energy transfer from triphenylamine to coumarin moieties.

  20. Design considerations to enhance the performances of thin circular piezoelectric energy harvester diaphragms in harsh liquid environments

    NASA Astrophysics Data System (ADS)

    Besse, N.; Pisano, A. P.; de Rooij, N. F.

    2013-12-01

    Thin circular piezoelectric energy harvester diaphragms undergoing large deflection in a harsh liquid environment are investigated in this paper. A material set combining AlN as transducer, SiC as electronics, Mo as wiring and Si as holder is considered. A highly accurate analytical model, which presents less than 5% error compared to FEM simulations in COMSOL, is first developed to study thoroughly flat diaphragms. Consequently, etching the wafer and adding a corrugation are proposed to reduce both the stress concentration at the edge and the influence of residual stress on the device behavior, respectively. Both ideas are predicted to increase the power density compared to the standard flat case by at least a factor of 5 to 10.

  1. Pucksat Payload Carrier

    NASA Technical Reports Server (NTRS)

    Milam, M. Bruce; Young, Joseph P.

    1999-01-01

    There is an ever-expanding need to provide economical space launch opportunities for relatively small science payloads. To address this need, a team at NASA's Goddard Space Flight Center has designed the Pucksat. The Pucksat is a highly versatile payload carrier structure compatible for launching on a Delta II two-stage vehicle as a system co-manifested with a primary payload. It is also compatible for launch on the Air Force Medium Class EELV. Pucksat's basic structural architecture consists of six honeycomb panels attached to six longerons in a hexagonal manner and closed off at the top and bottom with circular rings. Users may configure a co-manifested Pucksat in a number of ways. As examples, co-manifested configurations can be designed to accommodate dedicated missions, multiple experiments, multiple small deployable satellites, or a hybrid of the preceding examples. The Pucksat has fixed lateral dimensions and a downward scaleable height. The dimension across the panel hexagonal flats is 62 in. and the maximum height configuration dimension is 38.5 in. Pucksat has been designed to support a 5000 lbm primary payload, with the center of gravity located no greater than 60 in. from its separation plane, and to accommodate a total co-manifested payload mass of 1275 lbm.

  2. Performance evaluation and comparative analysis of SubCarrier Modulation Wake-up Radio systems for energy-efficient wireless sensor networks.

    PubMed

    Oller, Joaquim; Demirkol, Ilker; Casademont, Jordi; Paradells, Josep; Gamm, Gerd Ulrich; Reindl, Leonhard

    2013-01-01

    Energy-efficient communication is one of the main concerns of wireless sensor networks nowadays. A commonly employed approach for achieving energy efficiency has been the use of duty-cycled operation of the radio, where the node's transceiver is turned off and on regularly, listening to the radio channel for possible incoming communication during its on-state. Nonetheless, such a paradigm performs poorly for scenarios of low or bursty traffic because of unnecessary activations of the radio transceiver. As an alternative technology, Wake-up Radio (WuR) systems present a promising energy-efficient network operation, where target devices are only activated in an on-demand fashion by means of a special radio signal and a WuR receiver. In this paper, we analyze a novel wake-up radio approach that integrates both data communication and wake-up functionalities into one platform, providing a reconfigurable radio operation. Through physical experiments, we characterize the delay, current consumption and overall operational range performance of this approach under different transmit power levels. We also present an actual single-hop WuR application scenario, as well as demonstrate the first true multi-hop capabilities of a WuR platform and simulate its performance in a multi-hop scenario. Finally, by thorough qualitative comparisons to the most relevant WuR proposals in the literature, we state that the proposed WuR system stands out as a strong candidate for any application requiring energy-efficient wireless sensor node communications. PMID:24451452

  3. Performance Evaluation and Comparative Analysis of SubCarrier Modulation Wake-up Radio Systems for Energy-Efficient Wireless Sensor Networks

    PubMed Central

    Oller, Joaquim; Demirkol, Ilker; Casademont, Jordi; Paradells, Josep; Gamm, Gerd Ulrich; Reindl, Leonhard

    2014-01-01

    Energy-efficient communication is one of the main concerns of wireless sensor networks nowadays. A commonly employed approach for achieving energy efficiency has been the use of duty-cycled operation of the radio, where the node's transceiver is turned off and on regularly, listening to the radio channel for possible incoming communication during its on-state. Nonetheless, such a paradigm performs poorly for scenarios of low or bursty traffic because of unnecessary activations of the radio transceiver. As an alternative technology, Wake-up Radio (WuR) systems present a promising energy-efficient network operation, where target devices are only activated in an on-demand fashion by means of a special radio signal and a WuR receiver. In this paper, we analyze a novel wake-up radio approach that integrates both data communication and wake-up functionalities into one platform, providing a reconfigurable radio operation. Through physical experiments, we characterize the delay, current consumption and overall operational range performance of this approach under different transmit power levels. We also present an actual single-hop WuR application scenario, as well as demonstrate the first true multi-hop capabilities of a WuR platform and simulate its performance in a multi-hop scenario. Finally, by thorough qualitative comparisons to the most relevant WuR proposals in the literature, we state that the proposed WuR system stands out as a strong candidate for any application requiring energy-efficient wireless sensor node communications. PMID:24451452

  4. Cu2ZnSnSe4 nanocrystals capped with S(2-) by ligand exchange: utilizing energy level alignment for efficiently reducing carrier rec ombination.

    PubMed

    Wang, Xia; Kou, Dong-Xing; Zhou, Wen-Hui; Zhou, Zheng-Ji; Wu, Si-Xin; Cao, Xuan

    2014-01-01

    In this work, we employed a convenient one-step synthesis method for synthesizing Cu2ZnSnSe4 (CZTSe) nanocrystals (NCs) in an excess selenium environment. This excess selenium situation enhanced the reaction of metal acetylacetonates with selenium, resulting in the burst nucleation of NCs at relatively low temperatures. The phase morphology and surface and optoelectronic properties of NCs before and after ligand exchange were discussed in depth. It was found that pure tetragonal-phase structure CZTSe NCs with approximately 1.7-eV bandgap could be synthesized. The removal of large organic molecules on CZTSe NCs after ligand exchange by S(2-) decreased the resistivity. The bandgap of the films after ligand exchange by 550°C selenization was also decreased due to better crystallinity. For potential application in CZTSe solar cells, we constructed an energy level diagram to explain the mutual effect between the absorption layer and CdS layer. Using cyclic voltammetry (CV) measurement, we found that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of CZTSe films shifted down after ligand exchange. After energy level alignment at the CdS/CZTSe interface, a type I band alignment structure was more conveniently formed after ligand exchange. This structure acted as the barrier against injection electrons from ZnO to the CZTSe layer, and recombination would subsequently be depressed. PMID:24994951

  5. Cu2ZnSnSe4 nanocrystals capped with S2− by ligand exchange: utilizing energy level alignment for efficiently reducing carrier rec ombination

    PubMed Central

    2014-01-01

    In this work, we employed a convenient one-step synthesis method for synthesizing Cu2ZnSnSe4 (CZTSe) nanocrystals (NCs) in an excess selenium environment. This excess selenium situation enhanced the reaction of metal acetylacetonates with selenium, resulting in the burst nucleation of NCs at relatively low temperatures. The phase morphology and surface and optoelectronic properties of NCs before and after ligand exchange were discussed in depth. It was found that pure tetragonal-phase structure CZTSe NCs with approximately 1.7-eV bandgap could be synthesized. The removal of large organic molecules on CZTSe NCs after ligand exchange by S2− decreased the resistivity. The bandgap of the films after ligand exchange by 550°C selenization was also decreased due to better crystallinity. For potential application in CZTSe solar cells, we constructed an energy level diagram to explain the mutual effect between the absorption layer and CdS layer. Using cyclic voltammetry (CV) measurement, we found that the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of CZTSe films shifted down after ligand exchange. After energy level alignment at the CdS/CZTSe interface, a type I band alignment structure was more conveniently formed after ligand exchange. This structure acted as the barrier against injection electrons from ZnO to the CZTSe layer, and recombination would subsequently be depressed. PMID:24994951

  6. Assessment of the energy dissipation parameters inside the draft tube of a liquid spout-fluid bed.

    PubMed

    Erbíl, Ayşe Ceçen; Turan, Mustafa

    2005-04-15

    Spouted beds are fluid-particle contactors in which the fluid is introduced centrally through a nozzle instead of a distributor plate, resulting in a regular particle circulation pattern. To assess the suitability of such sytems to environmental engineering applications such as filter backwashing and biofilm systems, a priori knowledge of the energy dissipation parameters is essential. A new model is developed for evaluating the energy dissipation parameters inside the draft tube of spout-fluid beds. The shear stress, velocity gradient, and turbulence fluctuation parameters in the draft tube of a liquid spout-fluid bed are calculated with the help of an energy equation for flows carrying suspensions and the experimentally determined pressure losses inside the draft tube and compared with results for particulately fluidized beds. A spout-fluid bed with a draft tube provides higher shear stress inside the draft tube than a fluidized bed. The mean velocity gradient in the draft tube is comparable to and higher than in a fluidized bed and increases with solids fraction. The turbulence dissipation coefficient decreases very slightlywith increasing solids fraction for both systems. Consequently, according to the model calculations, a spout-fluid bed with a draft tube can be an alternative to the classical fluidized bed filter backwashing system. PMID:15884391

  7. Comparison of liquid hot water and alkaline pretreatments of giant reed for improved enzymatic digestibility and biogas energy production.

    PubMed

    Jiang, Danping; Ge, Xumeng; Zhang, Quanguo; Li, Yebo

    2016-09-01

    Liquid hot water (LHW) and alkaline pretreatments of giant reed biomass were compared in terms of digestibility, methane production, and cost-benefit efficiency for electricity generation via anaerobic digestion with a combined heat and power system. Compared to LHW pretreatment, alkaline pretreatment retained more of the dry matter in giant reed biomass solids due to less severe conditions. Under their optimal conditions, LHW pretreatment (190°C, 15min) and alkaline pretreatment (20g/L of NaOH, 24h) improved glucose yield from giant reed by more than 2-fold, while only the alkaline pretreatment significantly (p<0.05) increased cumulative methane yield (by 63%) over that of untreated biomass (217L/kgVS). LHW pretreatment obtained negative net electrical energy production due to high energy input. Alkaline pretreatment achieved 27% higher net electrical energy production than that of non-pretreatment (3859kJ/kg initial total solids), but alkaline liquor reuse is needed for improved net benefit. PMID:27233098

  8. Mesophilic and thermophilic anaerobic digestion of the liquid fraction of pressed biowaste for high energy yields recovery.

    PubMed

    Micolucci, Federico; Gottardo, Marco; Cavinato, Cristina; Pavan, Paolo; Bolzonella, David

    2016-02-01

    Deep separate collection of the organic fraction of municipal solid waste generates streams with relatively low content of inert material and high biodegradability. This material can be conveniently treated to recovery both energy and material by means of simplified technologies like screw-press and extruder: in this study, the liquid fraction generated from pressed biowaste from kerbside and door-to-door collection was anaerobically digested in both mesophilic and thermophilic conditions while for the solid fraction composting is suggested. Continuous operation results obtained both in mesophilic and thermophilic conditions indicated that the anaerobic digestion of pressed biowaste was viable at all operating conditions tested, with the greatest specific gas production of 0.92m(3)/kgVSfed at an organic loading rate of 4.7kgVS/m(3)d in thermophilic conditions. Based on calculations the authors found that the expected energy recovery is highly positive. The contents of heavy metals and pathogens of fed substrate and effluent digestates were analyzed, and results showed low levels (below End-of-Waste 2014 criteria limits) for both the parameters thus indicating the good quality of digestate and its possible use for agronomic purposes. Therefore, both energy and material were effectively recovered. PMID:26427935

  9. 14 CFR Section 04 - Air Carrier Groupings

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 4 2014-01-01 2014-01-01 false Air Carrier Groupings Section 04 Section 04... REGULATIONS UNIFORM SYSTEM OF ACCOUNTS AND REPORTS FOR LARGE CERTIFICATED AIR CARRIERS Section 04 Air Carrier Groupings (a) All large certificated air carriers are placed into three basic air carrier groupings...

  10. 14 CFR Section 04 - Air Carrier Groupings

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 4 2013-01-01 2013-01-01 false Air Carrier Groupings Section 04 Section 04... REGULATIONS UNIFORM SYSTEM OF ACCOUNTS AND REPORTS FOR LARGE CERTIFICATED AIR CARRIERS Section 04 Air Carrier Groupings (a) All large certificated air carriers are placed into three basic air carrier groupings...

  11. 14 CFR Section 04 - Air Carrier Groupings

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 4 2011-01-01 2011-01-01 false Air Carrier Groupings Section 04 Section 04... REGULATIONS UNIFORM SYSTEM OF ACCOUNTS AND REPORTS FOR LARGE CERTIFICATED AIR CARRIERS Section 04 Air Carrier Groupings (a) All large certificated air carriers are placed into three basic air carrier groupings...

  12. 14 CFR Section 04 - Air Carrier Groupings

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 4 2010-01-01 2010-01-01 false Air Carrier Groupings Section 04 Section 04... REGULATIONS UNIFORM SYSTEM OF ACCOUNTS AND REPORTS FOR LARGE CERTIFICATED AIR CARRIERS Section 04 Air Carrier Groupings (a) All large certificated air carriers are placed into three basic air carrier groupings...

  13. Final Report: Developing Liquid Protection Schemes for Fusion Energy Reactor First Walls

    SciTech Connect

    Minami Yoda Said I. Abdel-Khalik

    2006-03-29

    Over the last year, the Georgia Tech group has experimentally studied vertical turbulent sheets of water issuing downwards into atmospheric pressure air at Reynolds numbers Re = U{sub 0}{delta}/{nu} = 53,000 and 120,000 and Weber numbers We = {rho}U{sub o} {sup 2}{delta}/{sigma} = 2,900 and 18,000, respectively. Here, U{sub o} is the average jet speed, {delta} is the jet thickness (short dimension) at the nozzle exit ({delta} = 1 cm), and {nu}, {rho} and {sigma} are the kinematic viscosity and density of water and the surface tension at the air-water interface, respectively. These Re and We values are about 50% and 20% of the prototypical values for HYLIFE-II, respectively. In this report, the flow coordinate system is defined so that the origin is at the center of the nozzle exit, with the x-axis along the flow direction, the y-axis along the long dimension of the nozzle, and the z-axis along the short dimension of the nozzle (cf. Fig. 1). During the final year of this project, we have made three contributions in the area of thermal-hydraulics of thick liquid protection, namely: (1) Experimentally demonstrated that removing as little as 1% of the total mass flux using boundary-layer (BL) cutting can reduce the number density of the drops due to turbulent breakup of the liquid sheet below the maximum background density levels recommended for HYLIFE-II of 5 x 10{sup -19} m{sup 3}; (2) Shown that a well-designed flow conditioning section upstream of the nozzle can greatly reduce surface ripple, and that boundary-layer cutting can be used in conjunction with well-designed flow conditioning to further reduce surface ripple below the 0.07{delta} beam-to-jet standoff proposed for HYLIFE-II; and (3) Quantified how different flow conditioner designs affect the rms fluctuations of the streamwise (x) and transverse (z) velocity components in the nozzle itself (i.e., upstream of the nozzle exit) and affect surface ripple in the near-field of the flow, or x {le} 25{delta}. The

  14. Plasmonic Hot Carrier Transport and Collection in Nanostructures

    NASA Astrophysics Data System (ADS)

    Jermyn, Adam; Sundararaman, Ravishankar; Narang, Prineha; Goddard, William; Atwater, Harry; Joint CenterArtificial Photosynthesis Collaboration

    2015-03-01

    Plasmonic resonances provide a promising pathway for efficiently capturing photons from solar radiation and improving photo-catalytic activity via hot carrier generation. Previous calculations have provided the prompt energy-momentum distributions of hot carriers, but have left open the question of their transport to collection surfaces [Accepted in Nature Communications]. As the overall efficiency of plasmonic devices is dependent not just on how many carriers are collected but also on their energy distribution, a transport model which tracks this distribution is of key importance. Here, we provide a first-principles model of this transport based upon at the linearized Boltzmann equation with the diffusive and ballistic regimes handled separately, and investigate the role of geometry on plasmonic hot carrier collection.

  15. Momentum Distribution and Ground-State Energy of Liquid 4He at the Absolute Zero Temperature

    NASA Astrophysics Data System (ADS)

    Nishiyama, T.; Watanabe, Y.

    1980-11-01

    In the scheme of the density and phase operator approach, the momentum distribution nk and the ground-state energy E0 are obtained by employing the structure factor and the radial distribution function calculated by Chang and Campbell for the Morse dipole-dipole potential. The condensate fraction, the ratio of the occupation number of the single-particle zero-momentum state N0/N amounts to 0.096. The momentum distribution diverges as k-1 in the low-wave number limit. The ground-state energy becomes E0=-6.9NK at the mean density ρ0=0.02185Å-3.

  16. Molecular dynamics simulation of vapour-liquid nucleation of water with constant energy

    NASA Astrophysics Data System (ADS)

    Duška, Michal; Němec, Tomáš; Hrubý, Jan; Vinš, Václav; Planková, Barbora

    2015-05-01

    The paper describes molecular dynamics study of nucleation of water in NVE ensemble. The numerical simulation was performed with the DL_POLY. The metastable steam consisting of 10976 water molecules with TIP4P/2005 potential was driven on the desired energy level by a simulation at constant temperature, and then the nucleation at constant energy was studied for several tens of nanoseconds, which was sufficient for clusters to evolve at hundred molecules size. The results were compared with the previously published results and the classical nucleation theory predictions.

  17. Light-induced pitch transitions in photosensitive cholesteric liquid crystals: effects of anchoring energy.

    PubMed

    Orlova, Tetiana N; Iegorov, Roman I; Kiselev, Alexei D

    2014-01-01

    We experimentally study how the cholesteric pitch P depends on the equilibrium pitch P0 in planar liquid crystal (LC) cells with both strong and semistrong anchoring conditions. The cholesteric phase was induced by dissolution in the nematic LC of the right-handed chiral dopant 7-dehydrocholesterol (7-DHC, provitamin D3) which transforms to left-handed tachysterol under the action of uv irradiation at the wavelength of 254 nm. By using the model of photoreaction kinetics we obtain the dependencies of isomer concentrations and, therefore, of the equilibrium pitch on the uv irradiation dose. The cholesteric pitch was measured as a function of irradiation time using the polarimetry method. In this method, the pitch is estimated from the experimental data on the irradiation time dependence of the ellipticity of light transmitted through the LC cells. It is found that the resulting dependence of the twist parameter 2D/P (D is the cell thickness) on the free twisting number parameter 2D/P0 shows jumplike behavior and agrees well with the known theoretical results for the anchoring potential of Rapini-Papoular form. PMID:24580242

  18. A liquid metal ion source in a high energy microprobe setup

    NASA Astrophysics Data System (ADS)

    Adamczewski, J.; Stephan, A.; Meijer, J.; Becker, H. W.; Bukow, H. H.; Rolfs, C.

    1999-10-01

    We describe first experiments with a new arrangement of the Bochum superconducting solenoid microprobe using a single ended electrostatic accelerator and the implementation of a high brightness Ga liquid metal ion source. In this setup the accelerator and the microprobe components are mounted on a common optical bench which is mechanically decoupled from the laboratory building via a separate basement. Care had to be taken of the ion optical adaptation of the source to the accelerator tube in order to preserve the source brightness in the entire experimental setup. The emittance characteristic of the Ga ion beam was determined directly at the location of the microprobe via automatic emittance scanning using the computer controlled slit system of the setup. By this means the parameters of the unfocused beam could be measured for both the accelerated case (315 keV) and the unaccelerated case (30 keV). It could be shown that the observed brightness of the source behind the extraction optics is about three orders of magnitude less than values quoted in the literature (˜10 6 A m -2 rad -2 eV -1) which were deduced from the virtual source size and the angular current density of the ion beam at the source tip. The parameters of the focused beam are presented.

  19. Light-induced pitch transitions in photosensitive cholesteric liquid crystals: Effects of anchoring energy

    NASA Astrophysics Data System (ADS)

    Orlova, Tetiana N.; Iegorov, Roman I.; Kiselev, Alexei D.

    2014-01-01

    We experimentally study how the cholesteric pitch P depends on the equilibrium pitch P0 in planar liquid crystal (LC) cells with both strong and semistrong anchoring conditions. The cholesteric phase was induced by dissolution in the nematic LC of the right-handed chiral dopant 7-dehydrocholesterol (7-DHC, provitamin D3) which transforms to left-handed tachysterol under the action of uv irradiation at the wavelength of 254 nm. By using the model of photoreaction kinetics we obtain the dependencies of isomer concentrations and, therefore, of the equilibrium pitch on the uv irradiation dose. The cholesteric pitch was measured as a function of irradiation time using the polarimetry method. In this method, the pitch is estimated from the experimental data on the irradiation time dependence of the ellipticity of light transmitted through the LC cells. It is found that the resulting dependence of the twist parameter 2D/P (D is the cell thickness) on the free twisting number parameter 2D/P0 shows jumplike behavior and agrees well with the known theoretical results for the anchoring potential of Rapini-Papoular form.

  20. Enhanced thermal energy harvesting performance of a cobalt redox couple in ionic liquid-solvent mixtures.

    PubMed

    Lazar, Manoj A; Al-Masri, Danah; MacFarlane, Douglas R; Pringle, Jennifer M

    2016-01-21

    Thermoelectrochemical cells are increasingly promising devices for harvesting waste heat, offering an alternative to the traditional semiconductor-based design. Advancement of these devices relies on new redox couple/electrolyte systems and an understanding of the interplay between the different factors that dictate device performance. The Seebeck coefficient (Se) of the redox couple in the electrolyte gives the potential difference achievable for a given temperature gradient across the device. Prior work has shown that a cobalt bipyridyl redox couple in ionic liquids (ILs) displays high Seebeck coefficients, but the thermoelectrochemical cell performance was limited by mass transport. Here we present the Se and thermoelectrochemical power generation performance of the cobalt couple in novel mixed IL/molecular solvent electrolyte systems. The highest power density of 880 mW m(-2), at a ΔT of 70 °C, was achieved with a 3 : 1 (v/v) MPN-[C2mim][B(CN)4] electrolyte combination. The significant power enhancement compared to the single solvent or IL systems results from a combination of superior ionic conductivity and higher diffusion coefficients, shown by electrochemical analysis of the different electrolytes. This is the highest power output achieved to-date for a thermoelectrochemical cell utilising a high boiling point redox electrolyte. PMID:26348719