National Library of Energy BETA

Sample records for thermal conductivity polyethylene

  1. Continuous Processing of High Thermal Conductivity Polyethylene...

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

    Processing of High Thermal Conductivity Polyethylene Fibers and Sheets Continuous Processing of High Thermal Conductivity Polyethylene Fibers and Sheets Massachusetts Institute of...

  2. Continuous Processing of High Thermal Conductivity Polyethylene...

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

    conductivity polyethylene fibers and sheets will be developed to replace metals and ceramics in heat-transfer devices. Project innovations include using massively parallel...

  3. Methods for increasing the thermal conductivity of ultra-high molecular weight polyethylene (UHMWPE)

    E-Print Network [OSTI]

    Miler, Josef L

    2006-01-01

    A two-part study was conducted to determine methods for producing ultra-high molecular weight polyethylene with high thermal conductivity by way of polymer chain orientation. The first portion of this report surveys current ...

  4. Giant Thermal Rectification from Polyethylene Nanofiber Thermal Diodes

    E-Print Network [OSTI]

    Zhang, Teng

    2015-01-01

    The realization of phononic computing is held hostage by the lack of high performance thermal devices. Here we show through theoretical analysis and molecular dynamics simulations that unprecedented thermal rectification factors (as large as 1.20) can be achieved utilizing the phase dependent thermal conductivity of polyethylene nanofibers. More importantly, such high thermal rectifications only need very small temperature differences (< 20 oC) across the device, which is a significant advantage over other thermal diodes which need temperature biases on the order of the operating temperature. Taking this into consideration, we show that the dimensionless temperature-scaled rectification factors of the polymer nanofiber diodes range from 12 to 25 - much larger than other thermal diodes (< 8). The polymer nanofiber thermal diode consists of a crystalline portion whose thermal conductivity is highly phase-sensitive and a cross-linked portion which has a stable phase. Nanoscale size effect can be utilized t...

  5. Cermet fuel thermal conductivity 

    E-Print Network [OSTI]

    Alvis, John Mark

    1988-01-01

    VITA 36 37 40 40 40 40 44 45 47 48 LIST OF FIGURES Figure Unit cell for derivation of model Page Heat Conduction Solution 22 3 Fission Gas Release Model 26 4A Metal Matrix Thermal Conductivity 4B Ceramic Fuel Thermal Conductivity 5... is based on the simple heat conduction equation. It is assumed that there is a uniform distribution of fuel particles in a regular array. A unit cell consists of a cube of matrix material of side length L, containing a spherical fuel particle of radius, r...

  6. Polymer geometry and Li+ conduction in poly(ethylene oxide)

    E-Print Network [OSTI]

    Averbuch, Amir

    Polymer geometry and Li+ conduction in poly(ethylene oxide) L. Gitelman a , M. Israeli b, , A: Lithium battery Polymer molecule Brownian motion Simulation Conductivity PEO a b s t r a c t We study of the amorphous PE structure is increased by mechanical stretching due to the unraveling of loops in the polymer

  7. Thermal resistance and phonon scattering at the interface between carbon nanotube and amorphous polyethylene

    E-Print Network [OSTI]

    Elliott, James

    dynamics study of heat conduction in carbon nanotube (CNT)/polyethylene (PE) composites. Particular thermal conductivity of a macroscopic CNT/PE composite is quantified based on an effective medium approximation model. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction Polymer composites are employed

  8. Thermal Conductivity of Polycrystalline Semiconductors and Ceramics

    E-Print Network [OSTI]

    Wang, Zhaojie

    2012-01-01

    35, (3-6), Dames, C. ; Chen, G. , Thermal Conductivity ofProperties of Matter: Thermal conductivity: nonmetallicSociety), Dames, C. ; Chen, G. , Thermal Conductivity of

  9. 1D-to-3D transition of photon heat conduction in polyethylene using molecular dynamics simulations

    E-Print Network [OSTI]

    Henry, Asegun Sekou Famake

    2009-01-01

    Experiments have demonstrated that the mechanical stretching of bulk polyethylene can increase its thermal conductivity by more than two orders of magnitude, from 0.35 W/mK to over 40W/mK, which is comparable to steel. ...

  10. Thermal Conduction in Graphene and Graphene Multilayers

    E-Print Network [OSTI]

    Ghosh, Suchismita

    2009-01-01

    1 1.2 Thermal transport atxv Introduction xii 1.1 Thermal conductivity and65 4.13 Thermal conductivity of graphene as a function of

  11. Cylindrical thermal contact conductance 

    E-Print Network [OSTI]

    Ayers, George Harold

    2004-09-30

    calculation term LL interface pressure calculation term m asperity slope; least-squares slope MM interface pressure calculation term n expected number of contact spots xv Nuc joint conductance P pressure Pr Prandtl number Q heat rate q heat rate q? heat flux...

  12. Thermal rectification at silicon-amorphous polyethylene interface Ming Hu,1,a

    E-Print Network [OSTI]

    Li, Baowen

    Thermal rectification at silicon-amorphous polyethylene interface Ming Hu,1,a Pawel Keblinski,1,b heat currents. We estimate that in the limit of large heat currents, the silicon-amorphous polyethylene by amorphous polymer polyethylene PE and silicon crystal. We will also show that the mecha- nism governing

  13. Low Conductivity Thermal Barrier Coatings

    E-Print Network [OSTI]

    Wadley, Haydn

    Low Conductivity Thermal Barrier Coatings A Dissertation Presented to The Faculty of the School ________________________________________________________________________ Abstract The dissertation begins by exploring the growth of 7YSZ coatings on vapor deposited NiCoCrAlY bond coats at different substrate rotation rates. The experiments show that as the rotation rate

  14. Thermal resistance and phonon scattering at the interface between carbon nanotube and amorphous polyethylene

    E-Print Network [OSTI]

    Elliott, James

    polyethylene Sho Hida a , Takuma Hori a , Takuma Shiga a , James Elliott b , Junichiro Shiomi a,c, a Department dynamics study of heat conduction in carbon nanotube (CNT)/polyethylene (PE) composites. Particular across the CNT/polyethylene interfaces ($1 Â 10À7 m2 K WÀ1 ) and a moder- ate but non

  15. Thermal Conductivity Of Rubble Piles

    E-Print Network [OSTI]

    Luan, Jing

    2015-01-01

    Rubble piles are a common feature of solar system bodies. They are composed of monolithic elements of ice or rock bound by gravity. Voids occupy a significant fraction of the volume of a rubble pile. They can exist up to pressure $P\\approx \\epsy\\mu$, where $\\epsy$ is the monolithic material's yield strain and $\\mu$ its rigidity. At low $P$, contacts between neighboring elements are confined to a small fraction of their surface areas. As a result, the effective thermal conductivity of a rubble pile, $\\kcon\\approx k(P/(\\epsy\\mu))^{1/2}$, can be orders of magnitude smaller than, $k$, the thermal conductivity of its monolithic elements. In a fluid-free environment, only radiation can transfer energy across voids. It contributes an additional component, $\\krad=16\\ell\\sigma T^3/3$, to the total effective conductivity, $\\keff=\\kcon +\\krad$. Here $\\ell$, the inverse of the opacity per unit volume, is of order the size of the elements and voids. An important distinction between $\\kcon$ and $\\krad$ is that the former i...

  16. Stochastic model of lithium ion conduction in poly,,ethylene oxide... L. Gitelman,1

    E-Print Network [OSTI]

    Averbuch, Amir

    Stochastic model of lithium ion conduction in poly,,ethylene oxide... L. Gitelman,1 A. Averbuch,2,a. We calculate the energy of configurations of one or two lithium ions in the loop and derive developed a model of lithium ion conduction in dilute and concentrated polymer electrolytes LiI:P EO n 3 n

  17. Thermal Conductivity of Electrons and Muons

    E-Print Network [OSTI]

    Gnedin, Oleg Y.

    Thermal Conductivity of Electrons and Muons in Neutron Star Cores O.Y. Gnedin and D.G. Yakovlev A thermal conductivity of dense matter (ae ? ¸ 10 14 g cm \\Gamma3 ) in neutron star cores with various expressions valid for a wide class of models of dense matter. 1 #12; 1 Introduction Thermal conductivity

  18. Thermal Conductivity of Graphene Laminate H. Malekpour,

    E-Print Network [OSTI]

    Thermal Conductivity of Graphene Laminate H. Malekpour, K.-H. Chang, J.-C. Chen, C.-Y. Lu, D. L, Manchester, United Kingdom *S Supporting Information ABSTRACT: We have investigated thermal conductivity and a set of suspended samples with the graphene laminate thickness from 9 to 44 m. The thermal conductivity

  19. Thermal conductivity of sputtered amorphous Ge films

    SciTech Connect (OSTI)

    Zhan, Tianzhuo; Xu, Yibin; Goto, Masahiro; Tanaka, Yoshihisa; Kato, Ryozo; Sasaki, Michiko; Kagawa, Yutaka [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan)] [National Institute for Materials Science, 1-2-1 Sengen, Tsukuba 305-0047 (Japan)

    2014-02-15

    We measured the thermal conductivity of amorphous Ge films prepared by magnetron sputtering. The thermal conductivity was significantly higher than the value predicted by the minimum thermal conductivity model and increased with deposition temperature. We found that variations in sound velocity and Ge film density were not the main factors in the high thermal conductivity. Fast Fourier transform patterns of transmission electron micrographs revealed that short-range order in the Ge films was responsible for their high thermal conductivity. The results provide experimental evidences to understand the underlying nature of the variation of phonon mean free path in amorphous solids.

  20. Thermal conductivity of bulk nanostructured lead telluride

    E-Print Network [OSTI]

    Hori, Takuma

    Thermal conductivity of lead telluride with embedded nanoinclusions was studied using Monte Carlo simulations with intrinsic phonon transport properties obtained from first-principles-based lattice dynamics. The ...

  1. Thermal Conductivity of Polycrystalline Semiconductors and Ceramics

    E-Print Network [OSTI]

    Wang, Zhaojie

    2012-01-01

    F. , Properties of Advanced Semiconductor Materials GaN,materials In the semiconductor community, thermal conductivity is a very important property

  2. Thermal conductivity measurements of Summit polycrystalline silicon.

    SciTech Connect (OSTI)

    Clemens, Rebecca; Kuppers, Jaron D.; Phinney, Leslie Mary

    2006-11-01

    A capability for measuring the thermal conductivity of microelectromechanical systems (MEMS) materials using a steady state resistance technique was developed and used to measure the thermal conductivities of SUMMiT{trademark} V layers. Thermal conductivities were measured over two temperature ranges: 100K to 350K and 293K to 575K in order to generate two data sets. The steady state resistance technique uses surface micromachined bridge structures fabricated using the standard SUMMiT fabrication process. Electrical resistance and resistivity data are reported for poly1-poly2 laminate, poly2, poly3, and poly4 polysilicon structural layers in the SUMMiT process from 83K to 575K. Thermal conductivity measurements for these polysilicon layers demonstrate for the first time that the thermal conductivity is a function of the particular SUMMiT layer. Also, the poly2 layer has a different variation in thermal conductivity as the temperature is decreased than the poly1-poly2 laminate, poly3, and poly4 layers. As the temperature increases above room temperature, the difference in thermal conductivity between the layers decreases.

  3. Thermal conductivity of bulk nanostructured lead telluride

    SciTech Connect (OSTI)

    Hori, Takuma [Department of Mechanical Engineering, The University of Tokyo, Bunkyo, Tokyo 113-8656 (Japan); Chen, Gang [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Shiomi, Junichiro, E-mail: shiomi@photon.t.u-tokyo.ac.jp [Department of Mechanical Engineering, The University of Tokyo, Bunkyo, Tokyo 113-8656 (Japan); PRESTO, Japan Science and Technology Agency, Kawaguchi, Saitama 332-0012 (Japan)

    2014-01-13

    Thermal conductivity of lead telluride with embedded nanoinclusions was studied using Monte Carlo simulations with intrinsic phonon transport properties obtained from first-principles-based lattice dynamics. The nanoinclusion/matrix interfaces were set to completely reflect phonons to model the maximum interface-phonon-scattering scenario. The simulations with the geometrical cross section and volume fraction of the nanoinclusions matched to those of the experiment show that the experiment has already reached the theoretical limit of thermal conductivity. The frequency-dependent analysis further identifies that the thermal conductivity reduction is dominantly attributed to scattering of low frequency phonons and demonstrates mutual adaptability of nanostructuring and local disordering.

  4. Increased thermal conductivity monolithic zeolite structures

    DOE Patents [OSTI]

    Klett, James (Knoxville, TN); Klett, Lynn (Knoxville, TN); Kaufman, Jonathan (Leonardtown, MD)

    2008-11-25

    A monolith comprises a zeolite, a thermally conductive carbon, and a binder. The zeolite is included in the form of beads, pellets, powders and mixtures thereof. The thermally conductive carbon can be carbon nano-fibers, diamond or graphite which provide thermal conductivities in excess of about 100 W/mK to more than 1,000 W/mK. A method of preparing a zeolite monolith includes the steps of mixing a zeolite dispersion in an aqueous colloidal silica binder with a dispersion of carbon nano-fibers in water followed by dehydration and curing of the binder is given.

  5. Electrical and thermal conductivities in dense plasmas

    SciTech Connect (OSTI)

    Faussurier, G. Blancard, C.; Combis, P.; Videau, L.

    2014-09-15

    Expressions for the electrical and thermal conductivities in dense plasmas are derived combining the Chester-Thellung-Kubo-Greenwood approach and the Kramers approximation. The infrared divergence is removed assuming a Drude-like behaviour. An analytical expression is obtained for the Lorenz number that interpolates between the cold solid-state and the hot plasma phases. An expression for the electrical resistivity is proposed using the Ziman-Evans formula, from which the thermal conductivity can be deduced using the analytical expression for the Lorenz number. The present method can be used to estimate electrical and thermal conductivities of mixtures. Comparisons with experiment and quantum molecular dynamics simulations are done.

  6. Continuous Processing of High Thermal Conductivity Polyethylene Fibers and

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p aDepartmentEnergy comparingDeep Vadose Zone - Professor Gang

  7. Continuous Processing of High Thermal Conductivity Polyethylene Fibers and Sheets

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i n c i p aDepartmentEnergy comparingDeep Vadose Zone - Professor

  8. Gas storage carbon with enhanced thermal conductivity

    DOE Patents [OSTI]

    Burchell, Timothy D. (Oak Ridge, TN); Rogers, Michael Ray (Knoxville, TN); Judkins, Roddie R. (Knoxville, TN)

    2000-01-01

    A carbon fiber carbon matrix hybrid adsorbent monolith with enhanced thermal conductivity for storing and releasing gas through adsorption and desorption is disclosed. The heat of adsorption of the gas species being adsorbed is sufficiently large to cause hybrid monolith heating during adsorption and hybrid monolith cooling during desorption which significantly reduces the storage capacity of the hybrid monolith, or efficiency and economics of a gas separation process. The extent of this phenomenon depends, to a large extent, on the thermal conductivity of the adsorbent hybrid monolith. This invention is a hybrid version of a carbon fiber monolith, which offers significant enhancements to thermal conductivity and potential for improved gas separation and storage systems.

  9. Continuous Processing of High Thermal Conductivity Fibers and...

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

    defects thermal conductivity drops significantly We aim to fabricate a continuous film with high thermal conductivity by disentangling and aligning polymer chains ...

  10. Glass-like thermal conductivity in high efficiency thermoelectric...

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

    Glass-like thermal conductivity in high efficiency thermoelectric materials Glass-like thermal conductivity in high efficiency thermoelectric materials Discusses strategies to...

  11. Anomalous heat conduction in polyethylene chains: Theory and molecular dynamics simulations

    E-Print Network [OSTI]

    Henry, Asegun

    In 1955 Fermi, Pasta, and Ulam showed that a simple model for a nonlinear one-dimensional chain of particles can be nonergodic, which implied infinite thermal conductivity. A more recent investigation of a realistic model ...

  12. Effective Thermal Conductivity of Graded Nanocomposites with Interfacial Thermal

    E-Print Network [OSTI]

    Paulino, Glaucio H.

    .M. Yin", G. H. Paulino", W.G. Buttlar", and L.Z. Sun'' '^Department of Civil and Environmental the effective thermal conductivity distribution in functionally graded materials (FGMs) considering the Kapitza is developed to derive the averaged heat flux field of the particle phase. Then the temperature gradient can

  13. Modeling and simulation of Li-ion conduction in poly(ethylene oxide)

    SciTech Connect (OSTI)

    Gitelman, L. [Faculty of Applied Mathematics, Technion, Haifa 32000 (Israel); Israeli, M. [Faculty of Computer Science, Technion, Haifa 32000 (Israel); Averbuch, A. [School of Computer Science, Tel Aviv University, Tel Aviv 69978 (Israel)], E-mail: amir@math.tau.ac.il; Nathan, M. [School of Electrical Engineering, Tel Aviv University, Tel Aviv 69978 (Israel); Schuss, Z. [School of Mathematical Sciences, Department of Applied Mathematics, Tel Aviv University, Tel Aviv 69978 (Israel); Golodnitsky, D. [School of Chemistry, Tel Aviv University, Tel Aviv 69978 (Israel)

    2007-12-10

    Polyethylene oxide (PEO) containing a lithium salt (e.g., LiI) serves as a solid polymer electrolyte (SPE) in thin-film batteries and its ionic conductivity is a key parameter of their performance. We model and simulate Li{sup +} ion conduction in a single PEO molecule. Our simplified stochastic model of ionic motion is based on an analogy between protein channels of biological membranes that conduct Na{sup +}, K{sup +}, and other ions, and the PEO helical chain that conducts Li{sup +} ions. In contrast with protein channels and salt solutions, the PEO is both the channel and the solvent for the lithium salt (e.g., LiI). The mobile ions are treated as charged spherical Brownian particles. We simulate Smoluchowski dynamics in channels with a radius of ca. 0.1 nm and study the effect of stretching and temperature on ion conductivity. We assume that each helix (molecule) forms a random angle with the axis between these electrodes and the polymeric film is composed of many uniformly distributed oriented boxes that include molecules with the same direction. We further assume that mechanical stretching aligns the molecular structures in each box along the axis of stretching (intra-box alignment). Our model thus predicts the PEO conductivity as a function of the stretching, the salt concentration and the temperature. The computed enhancement of the ionic conductivity in the stretch direction is in good agreement with experimental results. The simulation results are also in qualitative agreement with recent theoretical and experimental results.

  14. 1D-to-3D transition of phonon heat conduction in polyethylene using molecular dynamics simulations

    E-Print Network [OSTI]

    Henry, Asegun

    The thermal conductivity of nanostructures generally decreases with decreasing size because of classical size effects. The axial thermal conductivity of polymer chain lattices, however, can exhibit the opposite trend, ...

  15. Thermal contact conductance of a paper handsheet/metal interface 

    E-Print Network [OSTI]

    Ng, Kin Hung

    1990-01-01

    ) to determine the thermal contact conductance and effective thermal conductivity of anodized coatings. One chemically polished Aluminium 6061-T6 test specimen and seven specimens with anodized coatings varying in thickness from 60. 9 pm to 163. 8 pm were...

  16. Strain-controlled thermal conductivity in ferroic twinned films

    E-Print Network [OSTI]

    Li, Suzhi

    Large reversible changes of thermal conductivity are induced by mechanical stress, and the corresponding device is a key element for phononics applications. We show that the thermal conductivity ? of ferroic twinned thin ...

  17. Spherical Accretion with Anisotropic Thermal Conduction

    E-Print Network [OSTI]

    Prateek Sharma; Eliot Quataert; James M. Stone

    2008-07-05

    We study the effects of anisotropic thermal conduction on magnetized spherical accretion flows using global axisymmetric MHD simulations. In low collisionality plasmas, the Bondi spherical accretion solution is unstable to the magnetothermal instability (MTI). The MTI grows rapidly at large radii where the inflow is subsonic. For a weak initial field, the MTI saturates by creating a primarily radial magnetic field, i.e., by aligning the field lines with the background temperature gradient. The saturation is quasilinear in the sense that the magnetic field is amplified by a factor of $\\sim 10-30$ independent of the initial field strength (for weak fields). In the saturated state, the conductive heat flux is much larger than the convective heat flux, and is comparable to the field-free (Spitzer) value (since the field lines are largely radial). The MTI by itself does not appreciably change the accretion rate $\\dot M$ relative to the Bondi rate $\\dot M_B$. However, the radial field lines created by the MTI are amplified by flux freezing as the plasma flows in to small radii. Oppositely directed field lines are brought together by the converging inflow, leading to significant resistive heating. When the magnetic energy density is comparable to the gravitational potential energy density, the plasma is heated to roughly the virial temperature; the mean inflow is highly subsonic; most of the energy released by accretion is transported to large radii by thermal conduction; and the accretion rate $\\dot M \\ll \\dot M_B$. The predominantly radial magnetic field created by the MTI at large radii in spherical accretion flows may account for the stable Faraday rotation measure towards Sgr A* in the Galactic Center.

  18. Thermal conductivity of nanoparticle suspensions Shawn A. Putnam,a

    E-Print Network [OSTI]

    Braun, Paul

    Thermal conductivity of nanoparticle suspensions Shawn A. Putnam,a David G. Cahill, and Paul V We describe an optical beam deflection technique for measurements of the thermal diffusivity of fluid the thermal conductivity of ethanol-water mixtures; in nearly pure ethanol, the increase in thermal

  19. Experimental thermal conductivity and contact conductance of graphite composites 

    E-Print Network [OSTI]

    Jackson, Marian Christine

    1998-01-01

    Graphite fiber organic matrix composites were reviewed ics. for potential heat sink applications in the electronics packaging determined the effective transverse and longitudinal thermal industry. This experimental ...

  20. THERMAL CONDUCTIVITY OF POWDER INSULATIONS FOR CRYOGENIC STORAGE

    E-Print Network [OSTI]

    Chang, Ho-Myung

    THERMAL CONDUCTIVITY OF POWDER INSULATIONS FOR CRYOGENIC STORAGE VESSELS Y. S. Choi1 '3 , M. N of the present work was to develop a precise instrument for measuring the thermal conductivity of powder cylinder is thermally anchored to the coldhead of a single stage Gifford-McMahon cryocooler, while

  1. Abnormal thermal conductivity in tetragonal tungsten bronze Ba...

    Office of Scientific and Technical Information (OSTI)

    temperature interval. Substitution of Sr for Ba brings about a significant decrease in thermal conductivity at x???3 accompanied by development of a low-temperature...

  2. Development of a Test Technique to Determine the Thermal Conductivity...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Development of a Test Technique to Determine the Thermal Conductivity of Large Refractory Ceramic Test Specimens Citation Details In-Document Search Title:...

  3. Specific heat and thermal conductivity of explosives, mixtures...

    Office of Scientific and Technical Information (OSTI)

    Specific heat and thermal conductivity of explosives, mixtures, and plastic-bonded explosives determined experimentally Baytos, J.F. 45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL...

  4. Heat diode effect and negative differential thermal conductance...

    Office of Scientific and Technical Information (OSTI)

    Heat diode effect and negative differential thermal conductance across nanoscale metal-dielectric interfaces Citation Details In-Document Search Title: Heat diode effect and...

  5. Microscopic mechanism of low thermal conductivity in lead telluride

    SciTech Connect (OSTI)

    Delaire, Olivier A [ORNL; Ma, Jie [ORNL

    2012-01-01

    Themicroscopic physics behind low-lattice thermal conductivity of single-crystal rock salt lead telluride (PbTe) is investigated. Mode-dependent phonon (normal and umklapp) scattering rates and their impact on thermal conductivity were quantified by first-principles-based anharmonic lattice dynamics calculations that accurately reproduce thermal conductivity in a wide temperature range. The low thermal conductivity of PbTe is attributed to the scattering of longitudinal acoustic phonons by transverse optical phonons with large anharmonicity and small group velocity of the soft transverse acoustic phonons. This results in enhancing the relative contribution of optical phonons, which are usually minor heat carriers in bulk materials.

  6. On the thermal expansion of composite materials and cross-property connection between thermal expansion and thermal conductivity

    E-Print Network [OSTI]

    Sevostianov, Igor

    On the thermal expansion of composite materials and cross-property connection between thermal expansion and thermal conductivity Igor Sevostianov Department of Mechanical and Aerospace Engineering, New: Composite material Thermal expansion Cross-property Microstructure Thermal conductivity a b s t r a c

  7. Conductive Thermal Interaction in Evaporative Cooling Process 

    E-Print Network [OSTI]

    Kim, B. S.; Degelman, L. O.

    1990-01-01

    between water and entering air for thermal comfort. This hybrid system outperforms the two-stage evaporative cooler without employing a complicated heat exchanger (indirect system), if the temperature of underground water is lower than the ambient wet...

  8. Morphology and thermal conductivity of yttria-stabilized zirconia coatings

    E-Print Network [OSTI]

    Wadley, Haydn

    Morphology and thermal conductivity of yttria-stabilized zirconia coatings Hengbei Zhao a vapor deposition method was used to grow 7 wt.% Y2O3­ZrO2 (7YSZ) coatings and the effects of substrate rotation upon the coating porosity, morphology, texture, and thermal conductivity were explored

  9. Monte Carlo Simulations of Thermal Conductivity in Nanoporous Si Membranes

    E-Print Network [OSTI]

    1 Monte Carlo Simulations of Thermal Conductivity in Nanoporous Si Membranes Stefanie Wolf1 transport in Si nanomeshes. Phonons are treated semiclassically as particles of specific energy and velocity, ii) the roughness amplitude of the pore surfaces on the thermal conductivity of the nanomeshes. We

  10. 3 omega method for specific heat and thermal conductivity measurements

    E-Print Network [OSTI]

    L. Lu; W. Yi; D. L. Zhang

    2002-02-06

    We present a 3 omega method for simultaneously measuring the specific heat and thermal conductivity of a rod- or filament-like specimen using a way similar to a four-probe resistance measurement. The specimen in this method needs to be electrically conductive and with a temperature-dependent resistance, for acting both as a heater to create a temperature fluctuation and as a sensor to measure its thermal response. With this method we have successfully measured the specific heat and thermal conductivity of platinum wire specimens at cryogenic temperatures, and measured those thermal quantities of tiny carbon nanotube bundles some of which are only 10^-9 g in mass.

  11. THERMAL CONDUCTIVITY AND OTHER PROPERTIES OF CEMENTITIOUS GROUTS

    SciTech Connect (OSTI)

    ALLAN,M.

    1998-05-01

    The thermal conductivity and other properties cementitious grouts have been investigated in order to determine suitability of these materials for grouting vertical boreholes used with geothermal heat pumps. The roles of mix variables such as water/cement ratio, sand/cement ratio and superplasticizer dosage were measured. In addition to thermal conductivity, the cementitious grouts were also tested for bleeding, permeability, bond to HDPE pipe, shrinkage, coefficient of thermal expansion, exotherm, durability and environmental impact. This paper summarizes the results for selected grout mixes. Relatively high thermal conductivities were obtained and this leads to reduction in predicted bore length and installation costs. Improvements in shrinkage resistance and bonding were achieved.

  12. Conductivity and optical band gaps of polyethylene oxide doped with Li{sub 2}SO{sub 4} salt

    SciTech Connect (OSTI)

    Chapi, Sharanappa, E-mail: dehu2010@gmail.com; Raghu, S., E-mail: dehu2010@gmail.com; Subramanya, K., E-mail: dehu2010@gmail.com; Archana, K., E-mail: dehu2010@gmail.com; Mini, V., E-mail: dehu2010@gmail.com; Devendrappa, H., E-mail: dehu2010@gmail.com [Dept. of Physics, Mangalore University, Mangalagangothri-574199 (India)

    2014-04-24

    The conductivity and optical properties of Li{sub 2}SO{sub 4} doped polyethylene oxide (PEO) films were studied. The polymer electrolyte films are prepared using solution casting technique. The material phase change was confirmed by X-ray diffraction (XRD) technique. Optical absorption study was conducted using UV- Vis. Spectroscopy in the wavelength range 190–1100nm on pure and doped PEO films. The direct and indirect optical band gaps were found decreased from 5.81–4.51eV and 4.84–3.43eV respectively with increasing the Li{sub 2}SO{sub 4}. The conductivity found to increases with increasing the dopant concentration due to strong hopping mechanism at room temperature.

  13. Measurement of thermal conductivity in proton irradiated silicon

    SciTech Connect (OSTI)

    Marat Khafizov; Clarissa Yablinsky; Todd Allen; David Hurley

    2014-04-01

    We investigate the influence of proton irradiation on thermal conductivity in single crystal silicon. We apply laser based modulated thermoreflectance technique to extract the change in conductivity of the thin layer damaged by proton irradiation. Unlike time domain thermoreflectance techniques that require application of a metal film, we perform our measurement on uncoated samples. This provides greater sensitivity to the change in conductivity of the thin damaged layer. Using sample temperature as a parameter provides a means to deduce the primary defect structures that limit thermal transport. We find that under high temperature irradiation the degradation of thermal conductivity is caused primarily by extended defects.

  14. Thermal Conductivity from Core and Well log Data

    E-Print Network [OSTI]

    Hartmann, Andreas; Clauser, Christoph

    2008-01-01

    The relationships between thermal conductivity and other petrophysical properties have been analysed for a borehole drilled in a Tertiary Flysch sequence. We establish equations that permit us to predict rock thermal conductivity from logging data. A regression analysis of thermal conductivity, bulk density, and sonic velocity yields thermal conductivity with an average accuracy of better than 0.2 W/(m K). As a second step, logging data is used to compute a lithological depth profile, which in turn is used to calculate a thermal conductivity profile. From a comparison of the conductivity-depth profile and the laboratory data it can be concluded that thermal conductivity can be computed with an accuracy of less than 0.3 W/(m K)from conventional wireline data. The comparison of two different models shows that this approach can be practical even if old and incomplete logging data is used. The results can be used to infer thermal conductivity for boreholes without appropriate core data that are drilled in a simil...

  15. Odne Stokke Burheim Thermal Signature and Thermal Conductivities of PEM Fuel Cells

    E-Print Network [OSTI]

    Kjelstrup, Signe

    Odne Stokke Burheim Thermal Signature and Thermal Conductivities of PEM Fuel Cells Thesis-Holst for believing in me and for giving me the opportunity to join the work on the "Thermal Effects in Fuel cell The work presented here gives estimates on thermal gradients within the PEM fuel cell, an experimental

  16. Cryogenic cold war : closing the thermal conductivity gap 

    E-Print Network [OSTI]

    Kennedy, Julia Susan

    2013-07-01

    A critical analysis of published thermal conductivity data is presented which highlights failures in data extrapolation, unexplained sudden drops in previously observed material data sets and the clarity of equipment design. ...

  17. Investigation on thermal conductivity and AC impedance of graphite suspension

    E-Print Network [OSTI]

    Wang, Jianjian, S.M. Massachusetts Institute of Technology

    2011-01-01

    Over the past decade, some groups have reported that nanofluids, which are liquids containing suspensions of nanoparticles, have substantially higher thermal conductivity than that of the base fluids. However, the reported ...

  18. Experimental investigations of solid-solid thermal interface conductance

    E-Print Network [OSTI]

    Collins, Kimberlee C. (Kimberlee Chiyoko)

    2010-01-01

    Understanding thermal interface conductance is important for nanoscale systems where interfaces can play a critical role in heat transport. In this thesis, pump and probe transient thermoreflectance methods are used to ...

  19. Measurement and modeling thermal conductivity of baked products 

    E-Print Network [OSTI]

    Islas Rubio, Alma Rosa

    1990-01-01

    MEASUREMENT AND MODELING THERMAL CONDUCTIVITY OF BAKED PRODUCTS A Thesis by ALMA ROSA ISLAS RUBIO Submitted to the Office of Graduate Studies ot' Iexas ASM University in partial fulfillment of the requirements for the degree of MASTER... on thermal conductivity. Water content did not appear to be a, significant factor over the limited water content range studied. The models k = 0. 0598 + 0. 1270D and k = 0. 0844 + 0. 0892D were developed for bread and cakes, respectively. The statistical...

  20. Thermal radiation and conduction in microscale structures. Final report

    SciTech Connect (OSTI)

    Tien, C.L.

    1998-09-02

    The general objective of the current research program is to achieve a better understanding of the fundamental mechanisms of thermal radiation and heat conduction in microscale structures commonly encountered in engineering applications. Specifically, the program includes both experimental and analytical investigations of radiative heat transfer in microstructures, conductive heat transfer in micro devices, and short-pulse laser material interactions. Future work is planned to apply the knowledge of microscale heat transfer gained in this project to developing thermal insulating aerogel materials, thermal design schemes for quantum well lasers, and short-pulse laser micro-fabrication techniques. A listing of publications by Chang-Lin Tien is included.

  1. Thermal Conductivity for a Noisy Disordered Harmonic Chain

    E-Print Network [OSTI]

    Cedric Bernardin

    2008-08-05

    We consider a $d$-dimensional disordered harmonic chain (DHC) perturbed by an energy conservative noise. We obtain uniform in the volume upper and lower bounds for the thermal conductivity defined through the Green-Kubo formula. These bounds indicate a positive finite conductivity. We prove also that the infinite volume homogenized Green-Kubo formula converges.

  2. The Thermal Conductivity of Low Density Concretes Containing Perlite 

    E-Print Network [OSTI]

    Yarbrough, D. W.

    1985-01-01

    CONDUCTIVITY OF LOW DENSITY CONCRETES CONTAINING PERLITE David W. Yarbrough Department of Chemical Engineering Tennessee Technological University Cookeville, Tennessee ABSTRACT The thermal conductivity, k, of low density concretes made from Portland... cement and perlite has been measured near room temperature using an unguarded linear heat flow apparatus. Perlite based concretes having densities from 44.3 1b/ft 3 to 66.6 1b/ft 3 were found to have thermal conductivities from 1.55 Btu?in/ft 2 ?h...

  3. Process for fabricating composite material having high thermal conductivity

    DOE Patents [OSTI]

    Colella, Nicholas J. (Livermore, CA); Davidson, Howard L. (San Carlos, CA); Kerns, John A. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA)

    2001-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  4. Thermal conductivity at a disordered quantum critical point

    E-Print Network [OSTI]

    Hartnoll, Sean A; Santos, Jorge E

    2015-01-01

    Strongly disordered and strongly interacting quantum critical points are difficult to access with conventional field theoretic methods. They are, however, both experimentally important and theoretically interesting. In particular, they are expected to realize universal incoherent transport. Such disordered quantum critical theories have recently been constructed holographically by deforming a CFT by marginally relevant disorder. In this paper we find additional disordered fixed points via relevant disordered deformations of a holographic CFT. Using recently developed methods in holographic transport, we characterize the thermal conductivity in both sets of theories in 1+1 dimensions. The thermal conductivity is found to tend to a constant at low temperatures in one class of fixed points, and to scale as $T^{0.3}$ in the other. Furthermore, in all cases the thermal conductivity exhibits discrete scale invariance, with logarithmic in temperature oscillations superimposed on the low temperature scaling behavior....

  5. Thermally conductive cementitious grout for geothermal heat pump systems

    DOE Patents [OSTI]

    Allan, Marita (Old Field, NY)

    2001-01-01

    A thermally conductive cement-sand grout for use with a geothermal heat pump system. The cement sand grout contains cement, silica sand, a superplasticizer, water and optionally bentonite. The present invention also includes a method of filling boreholes used for geothermal heat pump systems with the thermally conductive cement-sand grout. The cement-sand grout has improved thermal conductivity over neat cement and bentonite grouts, which allows shallower bore holes to be used to provide an equivalent heat transfer capacity. In addition, the cement-sand grouts of the present invention also provide improved bond strengths and decreased permeabilities. The cement-sand grouts can also contain blast furnace slag, fly ash, a thermoplastic air entraining agent, latex, a shrinkage reducing admixture, calcium oxide and combinations thereof.

  6. Electron thermal conductivity owing to collisions between degenerate electrons

    E-Print Network [OSTI]

    P. S. Shternin; D. G. Yakovlev

    2006-08-17

    We calculate the thermal conductivity of electrons produced by electron-electron Coulomb scattering in a strongly degenerate electron gas taking into account the Landau damping of transverse plasmons. The Landau damping strongly reduces this conductivity in the domain of ultrarelativistic electrons at temperatures below the electron plasma temperature. In the inner crust of a neutron star at temperatures T electron conductivity due to electron-ion (electron-phonon) scattering and becomes competitive with the the electron conductivity due to scattering of electrons by impurity ions.

  7. High thermal conductivity lossy dielectric using a multi layer configuration

    DOE Patents [OSTI]

    Tiegs, Terry N. (Lenoir City, TN); Kiggans, Jr., James O. (Oak Ridge, TN)

    2003-01-01

    Systems and methods are described for loss dielectrics. A loss dielectric includes at least one high dielectric loss layer and at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer. A method of manufacturing a loss dielectric includes providing at least one high dielectric loss layer and providing at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer. The systems and methods provide advantages because the loss dielectrics are less costly and more environmentally friendly than the available alternatives.

  8. Developing a High Thermal Conductivity Fuel with Silicon Carbide Additives

    SciTech Connect (OSTI)

    baney, Ronald; Tulenko, James

    2012-11-20

    The objective of this research is to increase the thermal conductivity of uranium oxide (UO{sub 2}) without significantly impacting its neutronic properties. The concept is to incorporate another high thermal conductivity material, silicon carbide (SiC), in the form of whiskers or from nanoparticles of SiC and a SiC polymeric precursor into UO{sub 2}. This is expected to form a percolation pathway lattice for conductive heat transfer out of the fuel pellet. The thermal conductivity of SiC would control the overall fuel pellet thermal conductivity. The challenge is to show the effectiveness of a low temperature sintering process, because of a UO{sub 2}-SiC reaction at 1,377°C, a temperature far below the normal sintering temperature. Researchers will study three strategies to overcome the processing difficulties associated with pore clogging and the chemical reaction of SiC and UO{sub 2} at temperatures above 1,300°C:

  9. Thermal Conductivity Enhancement of High Temperature Phase Change Materials for Concentrating Solar Power Plant Applications

    E-Print Network [OSTI]

    Roshandell, Melina

    2013-01-01

    RL.In: Proceedings on thermal energy storage and energypolymer microcomposites for thermal energy storage. SAE Sochigher volumetric energy density and thermal conductivity.

  10. Pretest Caluculations of Temperature Changes for Field Thermal Conductivity Tests

    SciTech Connect (OSTI)

    N.S. Brodsky

    2002-07-17

    A large volume fraction of the potential monitored geologic repository at Yucca Mountain may reside in the Tptpll (Tertiary, Paintbrush Group, Topopah Spring Tuff, crystal poor, lower lithophysal) lithostratigraphic unit. This unit is characterized by voids, or lithophysae, which range in size from centimeters to meters. A series of thermal conductivity field tests are planned in the Enhanced Characterization of the Repository Block (ECRB) Cross Drift. The objective of the pretest calculation described in this document is to predict changes in temperatures in the surrounding rock for these tests for a given heater power and a set of thermal transport properties. The calculation can be extended, as described in this document, to obtain thermal conductivity, thermal capacitance (density x heat capacity, J {center_dot} m{sup -3} {center_dot} K{sup -1}), and thermal diffusivity from the field data. The work has been conducted under the ''Technical Work Plan For: Testing and Monitoring'' (BSC 2001). One of the outcomes of this analysis is to determine the initial output of the heater. This heater output must be sufficiently high that it will provide results in a reasonably short period of time (within several weeks or a month) and be sufficiently high that the heat increase is detectable by the instruments employed in the test. The test will be conducted in stages and heater output will be step increased as the test progresses. If the initial temperature is set too high, the experiment will not have as many steps and thus fewer thermal conductivity data points will result.

  11. The effect of thermal aging on the thermal conductivity of plasma sprayed and EB-PVD thermal barrier coatings

    SciTech Connect (OSTI)

    Dinwiddie, R.B.; Beecher, S.C.; Porter, W.D.; Nagaraj, B.A.

    1996-05-01

    Thermal barrier coatings (TBCs) applied to the hot gas components of turbine engines lead to enhanced fuel efficiency and component reliability. Understanding the mechanisms which control the thermal transport behavior of the TBCs is of primary importance. Electron beam-physical vapor deposition (EV-PVD) and air plasma spraying (APS) are the two most commonly used coating techniques. These techniques produce coatings with unique microstructures which control their performance and stability. The density of the APS coatings was controlled by varying the spray parameters. The low density APS yttria-partially stabilized zirconia (yttria-PSZ) coatings yielded a thermal conductivity that is lower than both the high density APS coatings and the EB-PVD coatings. The thermal aging of both fully and partially stabilized zirconia are compared. The thermal conductivity of the coatings permanently increases upon exposure to high temperatures. These increases are attributed to microstructural changes within the coatings. This increase in thermal conductivity can be modeled using a relationship which depends on both the temperature and time of exposure. Although the EB-PVD coatings are less susceptible to thermal aging effects, results suggest that they typically have a higher thermal conductivity than APS coatings before thermal aging. The increases in thermal conductivity due to thermal aging for plasma sprayed partially stabilized zirconia have been found to be less than for plasma sprayed fully stabilized zirconia coatings.

  12. Mode dependent lattice thermal conductivity of single layer graphene

    SciTech Connect (OSTI)

    Wei, Zhiyong; Yang, Juekuan; Bi, Kedong; Chen, Yunfei, E-mail: yunfeichen@seu.edu.cn [Jiangsu Key Laboratory for Design and Manufacture of Micro/Nano Biomedical Instruments and School of Mechanical Engineering, Southeast University, Nanjing 210096 (China)

    2014-10-21

    Molecular dynamics simulation is performed to extract the phonon dispersion and phonon lifetime of single layer graphene. The mode dependent thermal conductivity is calculated from the phonon kinetic theory. The predicted thermal conductivity at room temperature exhibits important quantum effects due to the high Debye temperature of graphene. But the quantum effects are reduced significantly when the simulated temperature is as high as 1000 K. Our calculations show that out-of-plane modes contribute about 41.1% to the total thermal conductivity at room temperature. The relative contribution of out-of-plane modes has a little decrease with the increase of temperature. Contact with substrate can reduce both the total thermal conductivity of graphene and the relative contribution of out-of-plane modes, in agreement with previous experiments and theories. Increasing the coupling strength between graphene and substrate can further reduce the relative contribution of out-of-plane modes. The present investigations also show that the relative contribution of different mode phonons is not sensitive to the grain size of graphene. The obtained phonon relaxation time provides useful insight for understanding the phonon mean free path and the size effects in graphene.

  13. Thermal conductivity of silicene from first-principles

    SciTech Connect (OSTI)

    Xie, Han; Bao, Hua, E-mail: hum@ghi.rwth-aachen.de, E-mail: hua.bao@sjtu.edu.cn [University of Michigan–Shanghai Jiao Tong University Joint Institute, Shanghai Jiao Tong University, Shanghai 200240 (China); Hu, Ming, E-mail: hum@ghi.rwth-aachen.de, E-mail: hua.bao@sjtu.edu.cn [Institute of Mineral Engineering, Division of Materials Science and Engineering, Faculty of Georesources and Materials Engineering, RWTH Aachen University, Aachen 52064 (Germany); Aachen Institute for Advanced Study in Computational Engineering Science (AICES), RWTH Aachen University, Aachen 52062 (Germany)

    2014-03-31

    Silicene, as a graphene-like two-dimensional material, now receives exceptional attention of a wide community of scientists and engineers beyond graphene. Despite extensive study on its electric property, little research has been done to accurately calculate the phonon transport of silicene so far. In this paper, thermal conductivity of monolayer silicene is predicted from first-principles method. At 300?K, the thermal conductivity of monolayer silicene is found to be 9.4?W/mK and much smaller than bulk silicon. The contributions from in-plane and out-of-plane vibrations to thermal conductivity are quantified, and the out-of-plane vibration contributes less than 10% of the overall thermal conductivity, which is different from the results of the similar studies on graphene. The difference is explained by the presence of small buckling, which breaks the reflectional symmetry of the structure. The flexural modes are thus not purely out-of-plane vibration and have strong scattering with other modes.

  14. Low Thermal Conductance Transition Edge Sensor (TES) for SPICA

    SciTech Connect (OSTI)

    Khosropanah, P.; Dirks, B.; Kuur, J. van der; Ridder, M.; Bruijn, M.; Popescu, M.; Hoevers, H. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrech (Netherlands); Gao, J. R. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrech (Netherlands); Kavil Institute of NanoScience, Faculty of Applied Sciences, Delft University of Technology, Delft (Netherlands); Morozov, D.; Mauskopf, P. [School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff, CF24 3AA (United Kingdom)

    2009-12-16

    We fabricated and characterized low thermal conductance transition edge sensors (TES) for SAFARI instrument on SPICA. The device is based on a superconducting Ti/Au bilayer deposited on suspended SiN membrane. The critical temperature of the device is 113 mK. The low thermal conductance is realized by using long and narrow SiN supporting legs. All measurements were performed having the device in a light-tight box, which to a great extent eliminates the loading of the background radiation. We measured the current-voltage (IV) characteristics of the device in different bath temperatures and determine the thermal conductance (G) to be equal to 320 fW/K. This value corresponds to a noise equivalent power (NEP) of 3x10{sup -19} W/{radical}(Hz). The current noise and complex impedance is also measured at different bias points at 55 mK bath temperature. The measured electrical (dark) NEP is 1x10{sup -18} W/{radical}(Hz), which is about a factor of 3 higher than what we expect from the thermal conductance that comes out of the IV curves. Despite using a light-tight box, the photon noise might still be the source of this excess noise. We also measured the complex impedance of the same device at several bias points. Fitting a simple first order thermal-electrical model to the measured data, we find an effective time constant of about 2.7 ms and a thermal capacity of 13 fJ/K in the middle of the transition.

  15. Effect of interfacial interactions on the thermal conductivity and interfacial thermal conductance in tungsten–graphene layered structure

    SciTech Connect (OSTI)

    Jagannadham, K., E-mail: jag-kasichainula@ncsu.edu [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2014-09-01

    Graphene film was deposited by microwave plasma assisted deposition on polished oxygen free high conductivity copper foils. Tungsten–graphene layered film was formed by deposition of tungsten film by magnetron sputtering on the graphene covered copper foils. Tungsten film was also deposited directly on copper foil without graphene as the intermediate film. The tungsten–graphene–copper samples were heated at different temperatures up to 900?°C in argon atmosphere to form an interfacial tungsten carbide film. Tungsten film deposited on thicker graphene platelets dispersed on silicon wafer was also heated at 900?°C to identify the formation of tungsten carbide film by reaction of tungsten with graphene platelets. The films were characterized by scanning electron microscopy, Raman spectroscopy, and x-ray diffraction. It was found that tungsten carbide film formed at the interface upon heating only above 650?°C. Transient thermoreflectance signal from the tungsten film surface on the samples was collected and modeled using one-dimensional heat equation. The experimental and modeled results showed that the presence of graphene at the interface reduced the cross-plane effective thermal conductivity and the interfacial thermal conductance of the layer structure. Heating at 650 and 900?°C in argon further reduced the cross-plane thermal conductivity and interface thermal conductance as a result of formation nanocrystalline tungsten carbide at the interface leading to separation and formation of voids. The present results emphasize that interfacial interactions between graphene and carbide forming bcc and hcp elements will reduce the cross-plane effective thermal conductivity in composites.

  16. Interfacial thermal conductance in spun-cast polymer films and polymer brushes

    E-Print Network [OSTI]

    Braun, Paul

    Interfacial thermal conductance in spun-cast polymer films and polymer brushes Mark D. Losego inorganic materials and anharmonic polymers have potentially intriguing thermal transport behavior. The low thermal conductivity of amorphous polymers limits significant interfacial effects to polymer film

  17. Lattice thermal conductivity of filled skutterudites: An anharmonicity perspective

    SciTech Connect (OSTI)

    Geng, Huiyuan, E-mail: genghuiyuan@hit.edu.cn; Meng, Xianfu; Zhang, Hao; Zhang, Jian [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

    2014-10-28

    We report a phenomenological model to calculate the high-temperature lattice thermal conductivity of filled skutterudite antimonides. The model needs no phonon resonant scattering terms. Instead, we assume that umklapp processes dominate the high-temperature phonon scattering. In order to represent the anharmonicity introduced by the filling atom, we introduce a Gaussian term into the relaxation time of the umklapp process. The developed model agrees remarkably well with the experimental results of RE{sub f}Co{sub 4}Sb{sub 12} and RE{sub f}Fe{sub 4}Sb{sub 12} (RE?=?Yb, Ba, and Ca) alloys. To further test the validity of our model, we calculate the lattice thermal conductivity of nanostructured or multi-filled skutterudites. The calculation results are also in good agreement with experiment, increasing our confidence in the developed anharmonicity model.

  18. Thermal Conductivity of the Potential Repository Horizon Model Report

    SciTech Connect (OSTI)

    J. Ramsey

    2002-08-29

    The purpose of this report is to assess the spatial variability and uncertainty of thermal conductivity in the host horizon for the proposed repository at Yucca Mountain. More specifically, the lithostratigraphic units studied are located within the Topopah Spring Tuff (Tpt) and consist of the upper lithophysal zone (Tptpul), the middle nonlithophysal zone (Tptpmn), the lower lithophysal zone (Tptpll), and the lower nonlithophysal zone (Tptpln). The Tptpul is the layer directly above the repository host layers, which consist of the Tptpmn, Tptpll, and the Tptpln. Current design plans indicate that the largest portion of the repository will be excavated in the Tptpll (Board et al. 2002 [157756]). The main distinguishing characteristic among the lithophysal and nonlithophysal units is the percentage of large scale (cm-m) voids within the rock. The Tptpul and Tptpll, as their names suggest, have a higher percentage of lithophysae than the Tptpmn and the Tptpln. Understanding the influence of the lithophysae is of great importance to understanding bulk thermal conductivity and perhaps repository system performance as well. To assess the spatial variability and uncertainty of thermal conductivity, a model is proposed that is functionally dependent on the volume fraction of lithophysae and the thermal conductivity of the matrix portion of the rock. In this model, void space characterized as lithophysae is assumed to be air-saturated under all conditions, while void space characterized as matrix may be either water- or air-saturated. Lithophysae are assumed to be air-saturated under all conditions since the units being studied are all located above the water table in the region of interest, and the relatively strong capillary forces of the matrix will, under most conditions, preferentially retain any moisture present in the rock.

  19. Hot wire needle probe for thermal conductivity detection

    SciTech Connect (OSTI)

    Condie, Keith Glenn; Rempe, Joy Lynn; Knudson, Darrell lee; Daw, Joshua Earl; Wilkins, Steven Curtis; Fox, Brandon S.; Heng, Ban

    2015-11-10

    An apparatus comprising a needle probe comprising a sheath, a heating element, a temperature sensor, and electrical insulation that allows thermal conductivity to be measured in extreme environments, such as in high-temperature irradiation testing. The heating element is contained within the sheath and is electrically conductive. In an embodiment, the heating element is a wire capable of being joule heated when an electrical current is applied. The temperature sensor is contained within the sheath, electrically insulated from the heating element and the sheath. The electrical insulation electrically insulates the sheath, heating element and temperature sensor. The electrical insulation fills the sheath having electrical resistance capable of preventing electrical conduction between the sheath, heating element, and temperature sensor. The control system is connected to the heating element and the temperature sensor.

  20. Electrical conductivity and thermal dilepton rate from quenched lattice QCD

    E-Print Network [OSTI]

    Olaf Kaczmarek; Anthony Francis

    2011-09-19

    We report on a continuum extrapolation of the vector current correlation function for light valence quarks in the deconfined phase of quenched QCD. This is achieved by performing a systematic analysis of the influence of cut-off effects on light quark meson correlators at $T\\simeq 1.45 T_c$ using clover improved Wilson fermions. We discuss resulting constraints on the electrical conductivity and the thermal dilepton rate in a quark gluon plasma. In addition new results at 1.2 and 3.0 $T_c$ will be presented.

  1. Synthesis and Thermal Behavior of New Poly(ethylene terephthalate-imide)s

    E-Print Network [OSTI]

    Wan, Xin-hua

    INTRODUCTION Polyimides are important, commercially avail- able, high-performance polymers. They have found;polyimides have been discussed in the literature, the thermal and mechanical properties and the rheological

  2. Thermal Conductivity Enhancement of High Temperature Phase Change Materials for Concentrating Solar Power Plant Applications

    E-Print Network [OSTI]

    Roshandell, Melina

    2013-01-01

    demand for improving the thermal conductivity of PCM has led us to study effect of aluminum and copper

  3. On the eective thermal conductivity of a three-dimensionally structured uid-saturated metal foam

    E-Print Network [OSTI]

    Daraio, Chiara

    thermal conductivity to a large extent, a fact that must be dealt with in the foam manufacturing process thermal conductivity in the volume averaged homogeneous energy equation. Antohe et al. [11] also requiredOn the eective thermal conductivity of a three- dimensionally structured ¯uid-saturated metal foam

  4. Method for determining thermal conductivity and thermal capacity per unit volume of earth in situ

    DOE Patents [OSTI]

    Poppendiek, Heinz F. (LaJolla, CA)

    1982-01-01

    A method for determining the thermal conductivity of the earth in situ is based upon a cylindrical probe (10) having a thermopile (16) for measuring the temperature gradient between sets of thermocouple junctions (18 and 20) of the probe after it has been positioned in a borehole and has reached thermal equilibrium with its surroundings, and having means (14) for heating one set of thermocouple junctions (20) of the probe at a constant rate while the temperature gradient of the probe is recorded as a rise in temperature over several hours (more than about 3 hours). A fluid annulus thermally couples the probe to the surrounding earth. The recorded temperature curves are related to the earth's thermal conductivity, k.sub..infin., and to the thermal capacity per unit volume, (.gamma.c.sub.p).sub..infin., by comparison with calculated curves using estimates of k.sub..infin. and (.gamma.c.sub.p).sub..infin. in an equation which relates these parameters to a rise in the earth's temperature for a known and constant heating rate.

  5. Low Thermal Conductivity, High Durability Thermal Barrier Coatings for IGCC Environments

    SciTech Connect (OSTI)

    Jordan, Eric; Gell, Maurice

    2015-01-15

    Advanced thermal barrier coatings (TBC) are crucial to improved energy efficiency in next generation gas turbine engines. The use of traditional topcoat materials, e.g. yttria-stabilized zirconia (YSZ), is limited at elevated temperatures due to (1) the accelerated undesirable phase transformations and (2) corrosive attacks by calcium-magnesium-aluminum-silicate (CMAS) deposits and moisture. The first goal of this project is to use the Solution Precursor Plasma Spray (SPPS) process to further reduce the thermal conductivity of YSZ TBCs by introducing a unique microstructural feature of layered porosity, called inter-pass boundaries (IPBs). Extensive process optimization accompanied with hundreds of spray trials as well as associated SEM cross-section and laser-flash measurements, yielded a thermal conductivity as low as 0.62 Wm?¹K?¹ in SPPS YSZ TBCs, approximately 50% reduction of APS TBCs; while other engine critical properties, such as cyclic durability, erosion resistance and sintering resistance, were characterized to be equivalent or better than APS baselines. In addition, modifications were introduced to SPPS TBCs so as to enhance their resistance to CMAS under harsh IGCC environments. Several mitigation approaches were explored, including doping the coatings with Al?O? and TiO?, applying a CMAS infiltration-inhibiting surface layer, and filling topcoat cracks with blocking substances. The efficacy of all these modifications was assessed with a set of novel CMAS-TBC interaction tests, and the moisture resistance was tested in a custom-built high-temperature moisture rig. In the end, the optimal low thermal conductivity TBC system was selected based on all evaluation tests and its processing conditions were documented. The optimal coating consisted on a thick inner layer of YSZ coating made by the SPPS process having a thermal conductivity 50% lower than standard YSZ coatings topped with a high temperature tolerant CMAS resistant gadolinium zirconate Coating made by the SPPS process. Noteworthy was the fact that the YSZ to GZO interface made by the SPPS process was not the failure location as had been observed in APS coatings.

  6. Reexamination of Basal Plane Thermal Conductivity of Suspended Graphene Samples Measured by Electro-Thermal Micro-Bridge Methods

    SciTech Connect (OSTI)

    Jo, Insun; Pettes, Michael; Lindsay, Lucas R; Ou, Eric; Weathers, Annie; Moore, Arden; Yao, Zhen; Shi, Li

    2015-01-01

    Thermal transport in suspended graphene samples has been measured in prior works and this work with the use of a suspended electro-thermal micro-bridge method. These measurement results are analyzed here to evaluate and eliminate the errors caused by the extrinsic thermal contact resistance. It is noted that the thermal resistance measured in a recent work increases linearly with the suspended length of the single-layer graphene samples synthesized by chemical vapor deposition (CVD), and that such a feature does not reveal the failure of Fourier s law despite the increase in the apparent thermal conductivity with length. The re-analyzed thermal conductivity of a single-layer CVD graphene sample reaches about ( 1680 180 )Wm-1K-1 at room temperature, which is close to the highest value reported for highly oriented pyrolytic graphite. In comparison, the thermal conductivity values measured for two suspended exfoliated bi-layer graphene samples are about ( 880 60 ) and ( 730 60 ) Wm-1K-1 at room temperature, and approach that of the natural graphite source above room temperature. However, the low-temperature thermal conductivities of these suspended graphene samples are still considerably lower than the graphite values, with the peak thermal conductivities shifted to much higher temperatures. Analysis of the thermal conductivity data reveals that the low temperature behavior is dominated by phonon scattering by polymer residue instead of by the lateral boundary.

  7. Thermal Transport in Nanoporous Materials for Energy Applications

    E-Print Network [OSTI]

    Fang, Jin

    2012-01-01

    Thermal Conductivity Measurement . . . . . . . . . . . . .Thermal ConductivityThermal Conductivity . . . . . . . . . . . . . . . .Thermal

  8. Ceramic materials with low thermal conductivity and low coefficients of thermal expansion

    DOE Patents [OSTI]

    Brown, Jesse (Christiansburg, VA); Hirschfeld, Deidre (Elliston, VA); Liu, Dean-Mo (Blacksburg, VA); Yang, Yaping (Blacksburg, VA); Li, Tingkai (Blacksburg, VA); Swanson, Robert E. (Blacksburg, VA); Van Aken, Steven (Blacksburg, VA); Kim, Jin-Min (Seoul, KR)

    1992-01-01

    Compositions having the general formula (Ca.sub.x Mg.sub.1-x)Zr.sub.4 (PO.sub.4).sub.6 where x is between 0.5 and 0.99 are produced by solid state and sol-gel processes. In a preferred embodiment, when x is between 0.5 and 0.8, the MgCZP materials have near-zero coefficients of thermal expansion. The MgCZPs of the present invention also show unusually low thermal conductivities, and are stable at high temperatures. Macrostructures formed from MgCZP are useful in a wide variety of high-temperature applications. In a preferred process, calcium, magnesium, and zirconium nitrate solutions have their pH adjusted to between 7 and 9 either before or after the addition of ammonium dihydrogen phosphate. After dehydration to a gel, and calcination at temperatures in excess of 850.degree. C. for approximately 16 hours, single phase crystalline MgCZP powders with particle sizes ranging from approximately 20 nm to 50 nm result. The MgCZP powders are then sintered at temperatures ranging from 1200.degree. C. to 1350.degree. C. to form solid macrostructures with near-zero bulk coefficients of thermal expansion and low thermal conductivities. Porous macrostructures of the MgCZP powders of the present invention are also formed by combination with a polymeric powder and a binding agent, and sintering at high temperatures. The porosity of the resulting macrostructures can be adjusted by varying the particle size of the polymeric powder used.

  9. Ceramic materials with low thermal conductivity and low coefficients of thermal expansion

    DOE Patents [OSTI]

    Brown, J.; Hirschfeld, D.; Liu, D.M.; Yang, Y.; Li, T.; Swanson, R.E.; Van Aken, S.; Kim, J.M.

    1992-04-07

    Compositions, having the general formula (Ca[sub x]Mg[sub 1[minus]x])Zr[sub 4](PO[sub 4])[sub 6] where x is between 0.5 and 0.99, are produced by solid state and sol-gel processes. In a preferred embodiment, when x is between 0.5 and 0.8, the MgCZP materials have near-zero coefficients of thermal expansion. The MgCZPs of the present invention also show unusually low thermal conductivities, and are stable at high temperatures. Macrostructures formed from MgCZP are useful in a wide variety of high-temperature applications. In a preferred process, calcium, magnesium, and zirconium nitrate solutions have their pH adjusted to between 7 and 9 either before or after the addition of ammonium dihydrogen phosphate. After dehydration to a gel, and calcination at temperatures in excess of 850 C for approximately 16 hours, single phase crystalline MgCZP powders with particle sizes ranging from approximately 20 nm to 50 nm result. The MgCZP powders are then sintered at temperatures ranging from 1200 C to 1350 C to form solid macrostructures with near-zero bulk coefficients of thermal expansion and low thermal conductivities. Porous macrostructures of the MgCZP powders of the present invention are also formed by combination with a polymeric powder and a binding agent, and sintering at high temperatures. The porosity of the resulting macrostructures can be adjusted by varying the particle size of the polymeric powder used. 7 figs.

  10. Computational modeling of thermal conductivity of single walled carbon nanotube polymer composites

    E-Print Network [OSTI]

    Maruyama, Shigeo

    was developed to study the thermal conductivity of single walled carbon nanotube (SWNT)-polymer composites1 Computational modeling of thermal conductivity of single walled carbon nanotube polymer resistance on effective conductivity of composites were quantified. The present model is a useful tool

  11. Ultralow Thermal Conductivity in Organoclay Nanolaminates Synthesized via Simple Self-Assembly

    E-Print Network [OSTI]

    Braun, Paul

    Information ABSTRACT: Because interfaces impede phonon transport of thermal energy, nanostructuring canUltralow Thermal Conductivity in Organoclay Nanolaminates Synthesized via Simple Self-Assembly Mark of Chemistry, University of Illinois, Urbana Illinois 61801, United States § Materials and Manufacturing

  12. Reconstructing phonon mean-free-path contributions to thermal conductivity using nanoscale membranes

    E-Print Network [OSTI]

    Cuffe, John

    Knowledge of the mean-free-path distribution of heat-carrying phonons is key to understanding phonon-mediated thermal transport. We demonstrate that thermal conductivity measurements of thin membranes spanning a wide ...

  13. Reversible temperature regulation of electrical and thermal conductivity using liquid–solid phase transitions

    E-Print Network [OSTI]

    Zheng, Ruiting

    Reversible temperature tuning of electrical and thermal conductivities of materials is of interest for many applications, including seasonal regulation of building temperature, thermal storage and sensors. Here we introduce ...

  14. Thermal conductivity of configurable two-dimensional carbon nanotube architecture and strain modulation

    SciTech Connect (OSTI)

    Zhan, H. F.; Bell, J. M.; Gu, Y. T., E-mail: yuantong.gu@qut.edu.au [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, 2 George St., Brisbane, Queensland 4000 (Australia); Zhang, G. [Institute of High Performance Computing, Agency for Science, Technology and Research, 1 Fusionopolis Way, Singapore 138632 (Singapore)

    2014-10-13

    We reported the thermal conductivity of the two-dimensional carbon nanotube (CNT)-based architecture, which can be constructed through welding of single-wall CNTs by electron beam. Using large-scale nonequilibrium molecular dynamics simulations, the thermal conductivity is found to vary with different junction types due to their different phonon scatterings at the junction. The strong length and strain dependence of the thermal conductivity suggests an effective avenue to tune the thermal transport properties of the CNT-based architecture, benefiting the design of nanoscale thermal rectifiers or phonon engineering.

  15. An Analytical Study Of A 2-Layer Transient Thermal Conduction...

    Open Energy Info (EERE)

    The most demanding mathematical requirement is the ability to manipulate a 4 x 4 matrix. Testing the solution over a range of thermal diffusivity values expected in common...

  16. Materials for thermal conduction D.D.L. Chung *

    E-Print Network [OSTI]

    Chung, Deborah D.L.

    - ductivity (such as metals, carbons, ceramics and composites), and thermal interface materials (such thermal conductors such as diamond, metal-matrix composites and carbon-matrix composites are being used but its CTE is high. Therefore, copper-matrix composites containing low CTE ®llers such as carbon ®bers

  17. Tuning Interfacial Thermal Conductance of Graphene Embedded in Soft Materials by Vacancy Defects

    SciTech Connect (OSTI)

    Liu, Ying [Clemson University; Hu, Chongze [Clemson University; Huang, Jingsong [ORNL; Sumpter, Bobby G [ORNL; Qiao, Rui [Engineering Science and Mechanics Department, Virginia Tech, Blacksburg, VA, USA

    2015-01-01

    Nanocomposites based on graphene dispersed in matrices of soft materials are promising thermal management materials. Their effective thermal conductivity depends on both the thermal conductivity of graphene and the conductance of the thermal transport across graphene-matrix interfaces. Here we report on molecular dynamics simulations of the thermal transport across the interfaces between defected graphene and soft materials in two different modes: in the across mode, heat enters graphene from one side of its basal plane and leaves through the other side; in the non-across mode, heat enters or leaves a graphene simultaneously from both sides of its basal plane. We show that, as the density of vacancy defects in graphene increases from 0 to 8%, the conductance of the interfacial thermal transport in the across mode increases from 160.4 16 to 207.8 11 MW/m2K, while that in the non-across mode increases from 7.2 0.1 to 17.8 0.6 MW/m2K. The molecular mechanisms for these variations of thermal conductance are clarified by using the phonon density of states and structural characteristics of defected graphenes. On the basis of these results and effective medium theory, we show that it is possible to enhance the effective thermal conductivity of thermal nanocomposites by tuning the density of vacancy defects in graphene despite the fact that graphene s thermal conductivity always decreases as vacancy defects are introduced.

  18. Investigation of the thermal conductivity of unconsolidated sand packs containing oil, water, and gas 

    E-Print Network [OSTI]

    Gore, David Eugene

    1958-01-01

    INVESTIGATION OF THE THERNAL CONDUCTIVITY OF UNCONSOLIDATED SAND PACKS CONTAINING OIL, WATER, AND GAS A Thesis David E. Gore Submitted to the Graduate School of the Agricultural and Nechanical College oi' Texas in Partial fulfillment... and thxee-phase fluid saturation on the thermal conductivity of sand packs. The current research was conducted using a sand and lubricating oil on which related studies had been pexfoxmed. The thermal conductivity measuxements were made undex condi...

  19. Study of thermal conductivity in organic solid wastes before composting J. HUET, C. Druilhe, G. Debenest

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Study of thermal conductivity in organic solid wastes before composting J. HUET, C. Druilhe, G. Debenest ORBIT2012 1 STUDY OF THERMAL CONDUCTIVITY IN ORGANIC SOLID WASTES BEFORE COMPOSTING J. Huet and disposal. Composting can be defined as the process whereby aerobic micro-organisms convert organic

  20. Numerical and experimental investigations of the effective thermal conductivity of snow

    E-Print Network [OSTI]

    Numerical and experimental investigations of the effective thermal conductivity of snow N. Calonne numerical simulations of the conductiv- ity of snow using microtomographic images. The full tensor of the effective thermal conductivity (keff) was computed from 30 threedimensional images of the snow microstruc

  1. Origin of Low Thermal Conductivity in Nuclear Fuels Quan Yin and Sergey Y. Savrasov

    E-Print Network [OSTI]

    Savrasov, Sergej Y.

    Origin of Low Thermal Conductivity in Nuclear Fuels Quan Yin and Sergey Y. Savrasov Department.41.Bm Today's nuclear fuels are based on 235 U and 239 Pu ele- ments where in a typical setup, a nuclear, the thermal conductivity of UO2 is very low, and the search for alternative materials continues

  2. Analysis of Thermal Conductivity in Composite H.T. Banks and Kathleen L. Bihari

    E-Print Network [OSTI]

    are desirable in many industrial ap- plications, including computers, microelectronics, machinery and appliances a composite adhesive would aid in the design of an eÆcient thermally conductive composite adhesive. In this work, we provide theoretical foundations for use in design of thermally conductive composite adhesives

  3. Experimental investigation of the thermal conductivity of porous adsorbents. Master's thesis

    SciTech Connect (OSTI)

    Secary, J.J.

    1989-01-01

    The thermal conductivities of Praseodymium-Cerium-Oxide (PCO) and Saran Carbon have been experimentally investigated using a steady-state heat transfer technique. The investigated substances are used as adsorbents in adsorption compressors being developed for spaceborne refrigeration applications. The objectives of the investigation were to determine the thermal conductivities and establish their temperature dependency. Data were collected for the PCO over a temperature range of 300 C to 600 C, and O (zero) C to 200 C for the Saran Carbon. The thermal conductivities were found to have a strong temperature dependency. In particular, the results for the PCO showed a temperature dependency indicative of some thermal radiation effects.

  4. Communication: Minimum in the thermal conductivity of supercooled water: A computer simulation study

    SciTech Connect (OSTI)

    Bresme, F., E-mail: f.bresme@imperial.ac.uk [Chemical Physics Section, Department of Chemistry, Imperial College, London SW7 2AZ, United Kingdom and Department of Chemistry, Norwegian University of Science and Technology, Trondheim 7491 (Norway); Biddle, J. W.; Sengers, J. V.; Anisimov, M. A. [Institute for Physical Science and Technology, and Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742 (United States)] [Institute for Physical Science and Technology, and Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, Maryland 20742 (United States)

    2014-04-28

    We report the results of a computer simulation study of the thermodynamic properties and the thermal conductivity of supercooled water as a function of pressure and temperature using the TIP4P-2005 water model. The thermodynamic properties can be represented by a two-structure equation of state consistent with the presence of a liquid-liquid critical point in the supercooled region. Our simulations confirm the presence of a minimum in the thermal conductivity, not only at atmospheric pressure, as previously found for the TIP5P water model, but also at elevated pressures. This anomalous behavior of the thermal conductivity of supercooled water appears to be related to the maximum of the isothermal compressibility or the minimum of the speed of sound. However, the magnitudes of the simulated thermal conductivities are sensitive to the water model adopted and appear to be significantly larger than the experimental thermal conductivities of real water at low temperatures.

  5. The thermal conductivity of sediments as a function of porosity 

    E-Print Network [OSTI]

    Miller, James W

    1979-01-01

    as thermal barriers to heat and tend to insulate the surrounding material. Fig, 1 shows how the temperature gradient changes when a high pressured zone is encountered. Assuming the flow of heat through any zone obeys Fourier's law, the following equation... = thermal con- aT ductivity of the material, and z is the depth below the mudline. It can be seen from Equation 1 that if the heat flux, q, is constant and the temperature gradient, ~, is increased as is the case for a high z pressured zone...

  6. Thermal conductivity changes upon neutron transmutation of {sup 10}B doped diamond

    SciTech Connect (OSTI)

    Jagannadham, K., E-mail: jag-kasichainula@ncsu.edu [Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Verghese, K. [Nuclear Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States); Butler, J. E. [Code 6174, Naval research Laboratory, Washington, District of Columbia 20375 (United States)

    2014-08-28

    {sup 10}B doped p-type diamond samples were subjected to neutron transmutation reaction using thermal neutron flux of 0.9 × 10{sup 13} cm{sup ?2} s{sup ?1} and fast neutron flux of 0.09 × 10{sup 13} cm{sup ?2} s{sup ?1}. Another sample of epilayer grown on type IIa (110) single crystal diamond substrate was subjected to equal thermal and fast neutron flux of 10{sup 14}?cm{sup ?2} s{sup ?1}. The defects in the diamond samples were previously characterized by different methods. In the present work, thermal conductivity of these diamond samples was determined at room temperature by transient thermoreflectance method. The thermal conductivity change in the samples as a function of neutron fluence is explained by the phonon scattering from the point defects and disordered regions. The thermal conductivity of the diamond samples decreased more rapidly initially and less rapidly for larger neutron fluence. In addition, the thermal conductivity in type IIb diamond decreased less rapidly with thermal neutron fluence compared to the decrease in type IIa diamond subjected to fast neutron fluence. It is concluded that the rate of production of defects during transmutation reaction is slower when thermal neutrons are used. The thermal conductivity of epilayer of diamond subjected to high thermal and fast neutron fluence is associated with the covalent carbon network in the composite structure consisting of disordered carbon and sp{sup 2} bonded nanocrystalline regions.

  7. 1-Dimensional Numerical Model of Thermal Conduction and Vapor Diffusion

    E-Print Network [OSTI]

    Schörghofer, Norbert

    developed by Samar Khatiwala, 2001 extended to variable thermal properties and irregular grid by Norbert Sch for c. Upper boundary condition: a) Radiation Q + k T z z=0 = T4 z=0 Q is the incoming solar flux of Water Vapor with Phase Transitions developed by Norbert Sch¨orghofer, 2003­2004 3 phases: vapor, free

  8. Mechanical and transparent conductive properties of ZnO and Ga-doped ZnO films sputtered using electron-cyclotron-resonance plasma on polyethylene naphtalate substrates

    SciTech Connect (OSTI)

    Akazawa, Housei, E-mail: akazawa.housei@lab.ntt.co.jp [NTT Microsystem Integration Laboratories 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198 (Japan)

    2014-03-15

    Transparent conductive ZnO and Ga-doped ZnO (GZO) films were deposited on polyethylene naphtalate (PEN) sheet substrates using electron cyclotron resonance plasma sputtering. Both ZnO and GZO films were highly adhesive to the PEN substrates without inserting an intermediate layer in the interface. When compared at the same thickness, the transparent conductive properties of GZO films on PEN substrates were only slightly inferior to those on glass substrates. However, the carrier concentration of ZnO films on PEN substrates was 1.5?times that of those on glass substrates, whereas their Hall mobility was only 60% at a thickness of 300?nm. The depth profile of elements measured by secondary ion mass spectroscopy revealed the diffusion of hydrocarbons out of the PEN substrate into the ZnO film. Hence, doped carbons may act as donors to enhance carrier concentration, and the intermixing of elements at the interface may deteriorate the crystallinity, resulting in the lower Hall mobility. When the ZnO films were thicker than 400?nm, cracks became prevalent because of the lattice mismatch strain between the film and the substrate, whereas GZO films were free of cracks. The authors investigated how rolling the films around a cylindrical pipe surface affected their conductive properties. Degraded conductivity occurred at a threshold pipe radius of 10?mm when tensile stress was applied to the film, but it occurred at a pipe radius of 5?mm when compressive stress was applied. These values are guidelines for bending actual devices fabricated on PEN substrates.

  9. Effect of Polytetrafluoroethylene (PTFE) and micro porous layer (MPL) on thermal conductivity of fuel cell gas diffusion layers: Modeling and

    E-Print Network [OSTI]

    Bahrami, Majid

    Effect of Polytetrafluoroethylene (PTFE) and micro porous layer (MPL) on thermal conductivity robust model is devel- oped for estimating GDL thermal conductivity. The model considers PTFE addition of thermal conductivity on PTFE, MPL, and compression is considered. Thermal contact resistances between GDL

  10. Proximity nanovalve with large phase-tunable thermal conductance

    SciTech Connect (OSTI)

    Strambini, E., E-mail: e.strambini@sns.it; Giazotto, F., E-mail: f.giazotto@sns.it [NEST Istituto Nanoscienze-CNR and Scuola Normale Superiore, I-56127 Pisa (Italy); Bergeret, F. S., E-mail: sebastian-bergeret@ehu.es [Centro de Física de Materiales (CFM-MPC), Centro Mixto CSIC-UPV/EHU, Manuel de Lardizabal 4, E-20018 San Sebastián (Spain); Donostia International Physics Center (DIPC), Manuel de Lardizabal 5, E-20018 San Sebastián (Spain); Institut für Physik, Carl von Ossietzky Universität, D-26111 Oldenburg (Germany)

    2014-08-25

    We propose a phase-controlled heat-flux quantum valve based on the proximity effect driven by a superconducting quantum interference proximity transistor (SQUIPT). Its operation relies on the phase-dependent quasiparticle density of states in the Josephson weak-link of the SQUIPT which controls thermal transport across the device. In a realistic Al/Cu-based setup the structure can provide efficient control of thermal current inducing temperature swings exceeding ?100?mK, and flux-to-temperature transfer coefficients up to ?500?mK/?{sub 0} below 100?mK. The nanovalve performances improve by lowering the bath temperature, making the proposed structure a promising building-block for the implementation of coherent caloritronic devices operating below 1?K.

  11. Duality of the Interfacial Thermal Conductance in Graphene-based Nanocomposites

    SciTech Connect (OSTI)

    Liu, Ying [Clemson University] [Clemson University; Huang, Jingsong [ORNL] [ORNL; Yang, Bao [University of Maryland] [University of Maryland; Sumpter, Bobby G [ORNL] [ORNL; Qiao, Rui [Clemson University] [Clemson University

    2014-01-01

    The thermal conductance of graphene-matrix interfaces plays a key role in controlling the thermal transport properties of graphene-based nanocomposites. Using classical molecular dynamics simulations, we found that the interfacial thermal conductance depends strongly on the mode of heat transfer at the graphene-matrix interfaces: if heat enters graphene from one side of its basal plane and immediately leaves the graphene through the other side, the corresponding interfacial thermal conductance, G(across), is large; if heat enters graphene from both sides of its basal plane and leaves the graphene at a position far away on its basal plane, the corresponding interfacial thermal conductance, G(non-across), is small. For a single-layer graphene immersed in liquid octane, G(across) is ~150 MW/m2K while Gnon-across is ~5 MW/m2K. G(across) decreases with increasing multi-layer graphene thickness (i.e., number of layers in graphene) and approaches an asymptotic value of 100 MW/m2K for 7-layer graphenes. G(non-across) increases only marginally as the graphene sheet thickness increases. Such a duality of the interface thermal conductance for different probing methods and its dependence on graphene sheet thickness can be traced ultimately to the unique physical and chemical structure of graphene materials. The ramifications of these results in areas such as experimental measurement of thermal conductivity of graphene and the design of graphene-based thermal nanocomposites are discussed.

  12. Computational Efficient Upscaling Methodology for Predicting Thermal Conductivity of Nuclear Waste forms

    SciTech Connect (OSTI)

    Li, Dongsheng; Sun, Xin; Khaleel, Mohammad A.

    2011-09-28

    This study evaluated different upscaling methods to predict thermal conductivity in loaded nuclear waste form, a heterogeneous material system. The efficiency and accuracy of these methods were compared. Thermal conductivity in loaded nuclear waste form is an important property specific to scientific researchers, in waste form Integrated performance and safety code (IPSC). The effective thermal conductivity obtained from microstructure information and local thermal conductivity of different components is critical in predicting the life and performance of waste form during storage. How the heat generated during storage is directly related to thermal conductivity, which in turn determining the mechanical deformation behavior, corrosion resistance and aging performance. Several methods, including the Taylor model, Sachs model, self-consistent model, and statistical upscaling models were developed and implemented. Due to the absence of experimental data, prediction results from finite element method (FEM) were used as reference to determine the accuracy of different upscaling models. Micrographs from different loading of nuclear waste were used in the prediction of thermal conductivity. Prediction results demonstrated that in term of efficiency, boundary models (Taylor and Sachs model) are better than self consistent model, statistical upscaling method and FEM. Balancing the computation resource and accuracy, statistical upscaling is a computational efficient method in predicting effective thermal conductivity for nuclear waste form.

  13. eXtremes of heat conduction: Pushing the boundaries of the thermal

    E-Print Network [OSTI]

    Braun, Paul

    -called "nanofluids" (suspensions in liquids) ­ polymer composites and coatings Fischer (2007) Lehman (2005) #12;Critical aspect ratio for a fiber composite · Isotropic fiber composite with high conductivity fibers (andeXtremes of heat conduction: Pushing the boundaries of the thermal conductivity of materials David

  14. Effect of ligand on thermal dissipation from gold nanorods

    E-Print Network [OSTI]

    Alper, Joshua

    Thermal interface conductance was measured for soluble gold nanorods (NRs) coated with mercaptocarboxylic acids (HS-(CH[subscript 2])[subscript n]COOH, n = 5, 10, 15), thiolated polyethylene glycols (MW = 356, 1000, 5000), ...

  15. Theoretical investigation of the impact of grain boundaries and fission gases on UO2 thermal conductivity

    SciTech Connect (OSTI)

    Du, Shiyu; Andersson, Anders D.; Germann, Timothy C.; Stanek, Christopher R.

    2012-05-02

    Thermal conductivity is one of the most important metrics of nuclear fuel performance. Therefore, it is crucial to understand the impact of microstructure features on thermal conductivity, especially since the microstructure evolves with burn-up or time in the reactor. For example, UO{sub 2} fuels are polycrystalline and for high-burnup fuels the outer parts of the pellet experience grain sub-division leading to a very fine grain structure. This is known to impact important physical properties such as thermal conductivity as fission gas release. In a previous study, we calculated the effect of different types of {Sigma}5 grain boundaries on UO{sub 2} thermal conductivity and predicted the corresponding Kapitza resistances, i.e. the resistance of the grain boundary in relation to the bulk thermal resistance. There have been reports of pseudoanisotropic effects for the thermal conductivity in cubic polycrystalline materials, as obtained from molecular dynamics simulations, which means that the conductivity appears to be a function of the crystallographic direction of the temperature gradient. However, materials with cubic symmetry should have isotropic thermal conductivity. For this reason it is necessary to determine the cause of this apparent anisotropy and in this report we investigate this effect in context of our earlier simulations of UO{sub 2} Kapitza resistances. Another source of thermal resistance comes from fission products and fission gases. Xe is the main fission gas and when generated in sufficient quantity it dissolves from the lattice and forms gas bubbles inside the crystalline structure. We have performed studies of how Xe atoms dissolved in the UO{sub 2} matrix or precipitated as bubbles impact thermal conductivity, both in bulk UO{sub 2} and in the presence of grain boundaries.

  16. Serpentine Thermal Coupling Between a Stream and a Conducting Body

    SciTech Connect (OSTI)

    Kobayashi, H.; Lorente, S.; Anderson, R.; Bejan, A.

    2012-02-15

    Here we document the effect of flow configuration on the heat transfer performance of a serpentine shaped stream embedded in a conducting solid. Several configurations with fixed volume of fluid are considered: U-shaped with varying spacing between the parallel portions of the U, serpentine shapes with three elbows, and conducting soil with several parallelepipedal shapes. We show that the spacing must be greater than a critical value in order for the heat transfer density of the stream-solid configuration to be the highest that it can be. Spacings larger than this critical value do not yield improvements in heat transfer density. We also show that even though the heat transfer is time dependent, the stream-solid configuration has an effective number of heat transfer units Ntu that is nearly constant in time. The larger Ntu values correspond to the configurations with greater heat transfer density.

  17. Thermal Conduction in Aligned Carbon Nanotube–Polymer Nanocomposites with High Packing Density

    E-Print Network [OSTI]

    Marconnet, Amy M.

    Nanostructured composites containing aligned carbon nanotubes (CNTs) are very promising as interface materials for electronic systems and thermoelectric power generators. We report the first data for the thermal conductivity ...

  18. LARGE SCALE PERMEABILITY TEST OF THE GRANITE IN THE STRIPA MINE AND THERMAL CONDUCTIVITY TEST

    E-Print Network [OSTI]

    Lundstrom, L.

    2011-01-01

    No.2 LARGE SCALE PERMEABILITY TEST OF THE GRANITE' IN THEMINE AND, THERMAL CONDUCTIVITY TEST Lars Lundstrom and HakanSUMMARY REPORT Background TEST SITE Layout of test places

  19. Experimental study of thermal conductivity reduction of silicon-germanium nanocomposite for thermoelastic application

    E-Print Network [OSTI]

    Lee, Hohyun, 1978-

    2005-01-01

    To improve the thermoelectric energy conversion efficiency of silicon germanium (SiGe), two methods were used to decrease the thermal conductivity by increasing phonon boundary scattering at interfaces. In the first method, ...

  20. Thermal conductivity of fluids containing suspension of nanometer-sized particles

    E-Print Network [OSTI]

    Ma, Jack Jeinhao

    2006-01-01

    Nanofluids, which are fluids containing suspension of nanometer-sized particles, have been reported to possess substantially higher thermal conductivity than their respective base fluids. This thesis reports on an experimental ...

  1. Effective thermal conductivity method for predicting spent nuclear fuel cladding temperatures in a dry fill gas

    SciTech Connect (OSTI)

    Bahney, Robert

    1997-12-19

    This paper summarizes the development of a reliable methodology for the prediction of peak spent nuclear fuel cladding temperature within the waste disposal package. The effective thermal conductivity method replaces other older methodologies.

  2. Enhancing the thermoelectric figure of merit through the reduction of bipolar thermal conductivity with heterostructure barriers

    SciTech Connect (OSTI)

    Bahk, Je-Hyeong, E-mail: jbahk@purdue.edu; Shakouri, Ali [Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)

    2014-08-04

    In this paper, we present theoretically that the thermoelectric figure of merit for a semiconductor material with a small band gap can be significantly enhanced near the intrinsic doping regime at high temperatures via the suppression of bipolar thermal conductivity when the minority carriers are selectively blocked by heterostructure barriers. This scheme is particularly effective in nanostructured materials where the lattice thermal conductivity is lowered by increased phonon scatterings at the boundaries, so that the electronic thermal conductivity including the bipolar term is limiting the figure of merit zT. We show that zT can be enhanced to above 3 for p-type PbTe, and above 2 for n-type PbTe at 900?K with minority carrier blocking, when the lattice thermal conductivity is as low as 0.3?W/m K.

  3. Enhancing thermal conductivity of fluids with graphite nanoparticles and carbon nanotube

    DOE Patents [OSTI]

    Zhang, Zhiqiang (Lexington, KY); Lockwood, Frances E. (Georgetown, KY)

    2008-03-25

    A fluid media such as oil or water, and a selected effective amount of carbon nanomaterials necessary to enhance the thermal conductivity of the fluid. One of the preferred carbon nanomaterials is a high thermal conductivity graphite, exceeding that of the neat fluid to be dispersed therein in thermal conductivity, and ground, milled, or naturally prepared with mean particle size less than 500 nm, and preferably less than 200 nm, and most preferably less than 100 nm. The graphite is dispersed in the fluid by one or more of various methods, including ultrasonication, milling, and chemical dispersion. Carbon nanotubes with graphitic structure is another preferred source of carbon nanomaterial, although other carbon nanomaterials are acceptable. To confer long term stability, the use of one or more chemical dispersants is preferred. The thermal conductivity enhancement, compared to the fluid without carbon nanomaterial, is proportional to the amount of carbon nanomaterials (carbon nanotubes and/or graphite) added.

  4. Effective thermal conductivity measurements relevant to deep borehole nuclear waste disposal

    E-Print Network [OSTI]

    Shaikh, Samina

    2007-01-01

    The objective of this work was to measure the effective thermal conductivity of a number of materials (particle beds, and fluids) proposed for use in and around canisters for disposal of high level nuclear waste in deep ...

  5. Basal-plane thermal conductivity of few-layer molybdenum disulfide

    SciTech Connect (OSTI)

    Jo, Insun; Ou, Eric; Shi, Li; Pettes, Michael Thompson; Wu, Wei

    2014-05-19

    We report the in-plane thermal conductivity of suspended exfoliated few-layer molybdenum disulfide (MoS{sub 2}) samples that were measured by suspended micro-devices with integrated resistance thermometers. The obtained room-temperature thermal conductivity values are (44–50) and (48–52) W m{sup ?1} K{sup ?1} for two samples that are 4 and 7 layers thick, respectively. For both samples, the peak thermal conductivity occurs at a temperature close to 120?K, above which the thermal conductivity is dominated by intrinsic phonon-phonon scattering although phonon scattering by surface disorders can still play an important role in these samples especially at low temperatures.

  6. Thermal contact conductance of metallic coated superconductor/copper interfaces at cryogenic temperatures 

    E-Print Network [OSTI]

    Ochterbeck, Jay Matthew

    1990-01-01

    THERMAL CONTACT CONDUCTANCE OF METALLIC COATED SUPERCONDUCTOR/COPPER INTERFACES AT CRYOGENIC TEMPERATURES A Thesis by JAY MATTHEW OCHTERBECK Submitted to the 0%ce of Graduate Studies of Texas AJrM IJniversity in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1990 Major Subject: Mechanical Engineering THERMAL CONTACT CONDUCTANCE OF METALLIC COATED SUPERCONDUCTOR/COPPER INTERFACES AT CRYOGENIC TEMPERATURES A Thesis JA'r '(IATTHEW OCHTERBECK Approved...

  7. Thermal Conductivity in Nanoporous Gold Films during Electron-Phonon Nonequilibrium

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

    Hopkins, Patrick E.; Norris, Pamela M.; Phinney, Leslie M.; Policastro, Steven A.; Kelly, Robert G.

    2008-01-01

    The reduction of nanodevices has given recent attention to nanoporous materials due to their structure and geometry. However, the thermophysical properties of these materials are relatively unknown. In this article, an expression for thermal conductivity of nanoporous structures is derived based on the assumption that the finite size of the ligaments leads to electron-ligament wall scattering. This expression is then used to analyze the thermal conductivity of nanoporous structures in the event of electron-phonon nonequilibrium.

  8. Influence of Chemisorption on the Thermal Conductivity of Single-Wall

    E-Print Network [OSTI]

    Brenner, Donald W.

    composites. However, direct ex- perimental measurements of the thermal properties of CNT- polymer composites to a polymer matrix greatly improves the system's thermal conductivity,8,9 while others report that the effect transfer in CNT-polymer composites without significantly sacrificing the high axial Young's modulus of CNTs

  9. EFFECT OF PTFE ON THERMAL CONDUCTIVITY OF GAS DIFFUSION LAYERS OF PEM FUEL CELLS

    E-Print Network [OSTI]

    Bahrami, Majid

    The efficiency and performance of proton exchange membrane fuel cells (PEMFCs) depends heavily on the heat, the added PTFE can change the thermal resistance of GDLs and, hence, affects the fuel cell heat managementEFFECT OF PTFE ON THERMAL CONDUCTIVITY OF GAS DIFFUSION LAYERS OF PEM FUEL CELLS Hamidreza

  10. Thermal conductivities of individual tin dioxide nanobelts Qing Hao, and Choongho Yu

    E-Print Network [OSTI]

    Wang, Zhong L.

    transport in low- dimension materials. Recently, superhigh and significantly suppressed thermal.12,13 Compared to the knowledge ob- tained for nanotubes and nanowires, little has been known that the thermal conductivities of the nano- belts were strongly suppressed compared to the bulk values. According

  11. Propagation of three--dimensional Alfv'en waves in a stratified, thermally conducting solar wind

    E-Print Network [OSTI]

    Propagation of three--dimensional Alfv'en waves in a stratified, thermally conducting solar wind S to the well--known thermal expansion of the solar corona [Parker, 1958, 1963, 1991]. In particular Alfv'en waves in the solar atmosphere and wind, taking into account relevant physical effects

  12. Analysis of the Temporal Evolution of Thermal Conductivity in Alumina-Water Nanofluid 

    E-Print Network [OSTI]

    Fortenberry, Stephen

    2009-09-30

    of several months. This corresponded to a change in the thermal conductivity enhancement realized due to the suspension of nanoparticles in fluid from an initial value of 11.2% to a final value of 7.2%. Temporal evolution of the nanofluid’s thermal...

  13. Thermal desorption treatability test conducted with VAC*TRAX Unit

    SciTech Connect (OSTI)

    1996-01-01

    In 1992, Congress passed the Federal Facilities Compliance Act, requiring the U.S. Department of Energy (DOE) to treat and dispose of its mixed waste in accordance with Resource Conservation and Recovery Act (RCRA) treatment standards. In response to the need for mixed-waste treatment capacity, where off-site commercial treatment facilities do not exist or cannot be used, the DOE Albuquerque Operations Office (DOE-AL) organized a Treatment Selection Team to match mixed waste with treatment options and develop a strategy for treatment of mixed waste. DOE-AL manages nine sites with mixed-waste inventories. The Treatment Selection Team determined a need to develop mobile treatment units (MTUs) to treat waste at the sites where the wastes are generated. Treatment processes used for mixed wastes must remove the hazardous component (i.e., meet RCRA treatment standards) and contain the radioactive component in a form that will protect the worker, public, and environment. On the basis of the recommendations of the Treatment Selection Team, DOE-AL assigned projects to the sites to bring mixed-waste treatment capacity on-line. The three technologies assigned to the DOE Grand Junction Projects Office (DOE-GJPO) include thermal desorption (TD), evaporative oxidation, and waste water evaporation.

  14. Gallium ion implantation greatly reduces thermal conductivity and enhances electronic one of ZnO nanowires

    SciTech Connect (OSTI)

    Xia, Minggang, E-mail: xiamg@mail.xjtu.edu.cn [Laboratory of Nanostructure and its Physics Properties, Department of Optical Information Science and Technology, Department of Applied Physics, and MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi'an Jiaotong University, 710049 China (China); Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Cheng, Zhaofang; Han, Jinyun; Zhang, Shengli [Laboratory of Nanostructure and its Physics Properties, Department of Optical Information Science and Technology, Department of Applied Physics, and MOE Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter, School of Science, Xi'an Jiaotong University, 710049 China (China); Zheng, Minrui [Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); Sow, Chorng-Haur [Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); National University of Singapore Nanoscience and Nanotechnology Initiative, National University of Singapore, Singapore 117542 (Singapore); Thong, John T. L. [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Li, Baowen [Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542 (Singapore); National University of Singapore Nanoscience and Nanotechnology Initiative, National University of Singapore, Singapore 117542 (Singapore); Center for Phononics and Thermal Energy Science, School of Physics Science and Engineering, Tongji University, Shanghai 200092 (China)

    2014-05-15

    The electrical and thermal conductivities are measured for individual zinc oxide (ZnO) nanowires with and without gallium ion (Ga{sup +}) implantation at room temperature. Our results show that Ga{sup +} implantation enhances electrical conductivity by one order of magnitude from 1.01 × 10{sup 3} ?{sup ?1}m{sup ?1} to 1.46 × 10{sup 4} ?{sup ?1}m{sup ?1} and reduces its thermal conductivity by one order of magnitude from 12.7 Wm{sup ?1}K{sup ?1} to 1.22 Wm{sup ?1}K{sup ?1} for ZnO nanowires of 100 nm in diameter. The measured thermal conductivities are in good agreement with those in theoretical simulation. The increase of electrical conductivity origins in electron donor doping by Ga{sup +} implantation and the decrease of thermal conductivity is due to the longitudinal and transverse acoustic phonons scattering by Ga{sup +} point scattering. For pristine ZnO nanowires, the thermal conductivity decreases only two times when its diameter reduces from 100 nm to 46 nm. Therefore, Ga{sup +}-implantation may be a more effective method than diameter reduction in improving thermoelectric performance.

  15. Regulation of thermal conductivity in hot galaxy clusters by MHD turbulence

    E-Print Network [OSTI]

    Steven A. Balbus; Christopher S. Reynolds

    2008-06-05

    The role of thermal conduction in regulating the thermal behavior of cooling flows in galaxy clusters is reexamined. Recent investigations have shown that the anisotropic Coulomb heat flux caused by a magnetic field in a dilute plasma drives a dynamical instability. A long standing problem of cooling flow theory has been to understand how thermal conduction can offset radiative core losses without completely preventing them. In this Letter we propose that magnetohydrodynamic turbulence driven by the heat flux instability regulates field-line insulation and drives a reverse convective thermal flux, both of which may mediate the stabilization of the cooling cores of hot clusters. This model suggests that turbulent mixing should accompany strong thermal gradients in cooling flows. This prediction seems to be supported by the spatial distribution of metals in the central galaxies of clusters, which shows a much stronger correlation with the ambient hot gas temperature gradient than with the parent stellar population.

  16. Differential heating: A versatile method for thermal conductivity measurements in high-energy-density matter

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

    Ping, Y.; Fernandez-Panella, A.; Sio, H.; Correa, A.; Shepherd, R.; Landen, O.; London, R. A.; Sterne, P. A.; Whitley, H. D.; Fratanduono, D.; et al

    2015-09-04

    We propose a method for thermal conductivity measurements of high energy density matter based on differential heating. A temperature gradient is created either by surface heating of one material or at an interface between two materials by different energy deposition. The subsequent heat conduction across the temperature gradient is observed by various time-resolved probing techniques. Conceptual designs of such measurements using laser heating, proton heating, and x-ray heating are presented. As a result, the sensitivity of the measurements to thermal conductivity is confirmed by simulations.

  17. The measurement of thermal conductivity of jelly from 25 to 95 C 

    E-Print Network [OSTI]

    Chen, Yih-Rong

    1985-01-01

    of LMP jelly samples in the temperature range from 25 to 95 'C 53 16 Effect of pectin content on the thermal conductivity of HMP jelly samples in the temperature range from 25 to 95 'C . . . . . . . . . . 54 17 Jelly formation dependent upon pectin... conductivity of LMP jelly versus temperature at the moisture content between 60. 5 and 77. 1 percent, depicting how the regression lines fit to the experimental data 59 22 Comparison of linear r thermal conductivities and sugar solutions as content at 25...

  18. Nanoscale size dependence parameters on lattice thermal conductivity of Wurtzite GaN nanowires

    SciTech Connect (OSTI)

    Mamand, S.M., E-mail: soran.mamand@univsul.net [Department of Physics, College of Science, University of Sulaimani, Sulaimanyah, Iraqi Kurdistan (Iraq); Omar, M.S. [Department of Physics, College of Science, University of Salahaddin, Arbil, Iraqi Kurdistan (Iraq)] [Department of Physics, College of Science, University of Salahaddin, Arbil, Iraqi Kurdistan (Iraq); Muhammad, A.J. [Department of Physics, College of Science, University of Kirkuk, Kirkuk (Iraq)] [Department of Physics, College of Science, University of Kirkuk, Kirkuk (Iraq)

    2012-05-15

    Graphical abstract: Temperature dependence of calculated lattice thermal conductivity of Wurtzite GaN nanowires. Highlights: Black-Right-Pointing-Pointer A modified Callaway model is used to calculate lattice thermal conductivity of Wurtzite GaN nanowires. Black-Right-Pointing-Pointer A direct method is used to calculate phonon group velocity for these nanowires. Black-Right-Pointing-Pointer 3-Gruneisen parameter, surface roughness, and dislocations are successfully investigated. Black-Right-Pointing-Pointer Dislocation densities are decreases with the decrease of wires diameter. -- Abstract: A detailed calculation of lattice thermal conductivity of freestanding Wurtzite GaN nanowires with diameter ranging from 97 to 160 nm in the temperature range 2-300 K, was performed using a modified Callaway model. Both longitudinal and transverse modes are taken into account explicitly in the model. A method is used to calculate the Debye and phonon group velocities for different nanowire diameters from their related melting points. Effect of Gruneisen parameter, surface roughness, and dislocations as structure dependent parameters are successfully used to correlate the calculated values of lattice thermal conductivity to that of the experimentally measured curves. It was observed that Gruneisen parameter will decrease with decreasing nanowire diameters. Scattering of phonons is assumed to be by nanowire boundaries, imperfections, dislocations, electrons, and other phonons via both normal and Umklapp processes. Phonon confinement and size effects as well as the role of dislocation in limiting thermal conductivity are investigated. At high temperatures and for dislocation densities greater than 10{sup 14} m{sup -2} the lattice thermal conductivity would be limited by dislocation density, but for dislocation densities less than 10{sup 14} m{sup -2}, lattice thermal conductivity would be independent of that.

  19. Composite material having high thermal conductivity and process for fabricating same

    DOE Patents [OSTI]

    Colella, N.J.; Davidson, H.L.; Kerns, J.A.; Makowiecki, D.M.

    1998-07-21

    A process is disclosed for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost. 7 figs.

  20. Composite material having high thermal conductivity and process for fabricating same

    DOE Patents [OSTI]

    Colella, Nicholas J. (Livermore, CA); Davidson, Howard L. (San Carlos, CA); Kerns, John A. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA)

    1998-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  1. FAST STATIC AND DYNAMIC GRID LEVEL THERMAL SIMULATION CONSIDERING TEMPERATURE DEPENDENT THERMAL CONDUCTIVITY OF SILICON

    E-Print Network [OSTI]

    Ziabari, Amirkoushyar

    2012-01-01

    Power Blurring: Fast Chip-Level Static and Transient ThermalOF CALIFORNIA SANTA CRUZ FAST STATIC AND DYNAMIC GRID LEVEL3.3.3 A Static Case Study………………………………………………. 3.3.4 Transient

  2. Modeling the Influence of Interaction Layer Formation on Thermal Conductivity of U–Mo Dispersion Fuel

    SciTech Connect (OSTI)

    Burkes, Douglas; Casella, Andrew M.; Huber, Tanja K.

    2015-01-01

    The Global Threat Reduction Initiative Program continues to develop existing and new plate- and rod-type research and test reactor fuels with maximum attainable uranium loadings capable of potentially converting a number of the world’s remaining high-enriched uranium fueled reactors to low-enriched uranium fuel. Currently, the program is focused on assisting with the development and qualification of an even higher density fuel type consisting of a uranium-molybdenum (U-Mo) alloy dispersed in an aluminum matrix. Thermal conductivity is an important consideration in determining the operational temperature of the fuel plate and can be influenced by interaction layer formation between the fuel and matrix, porosity that forms during fabrication of the fuel plates, and upon the concentration of the dispersed phase within the matrix. This paper develops and validates a simple model to study the influence of interaction layer formation and conductivity, fuel particle size, and volume fraction of fuel dispersed in the matrix on the effective conductivity of the composite. The model shows excellent agreement with results previously presented in the literature. In particular, the thermal conductivity of the interaction layer does not appear to be important in determining the overall conductivity of the composite, while formation of the interaction layer and subsequent consumption of the matrix reveals a rather significant effect. The effective thermal conductivity of the composite can be influenced by the fuel particle distribution by minimizing interaction layer formation and preserving the higher thermal conductivity matrix.

  3. Thermal, tensile and rheological properties of high density polyethylene (HDPE) processed and irradiated by gamma-ray in different atmospheres

    SciTech Connect (OSTI)

    Ferreto, H. F. R. E-mail: ana-feitoza@yahoo.com.br; Oliveira, A. C. F. E-mail: ana-feitoza@yahoo.com.br; Parra, D. F. E-mail: ablugao@ipen.br; Lugão, A. B. E-mail: ablugao@ipen.br; Gaia, R.

    2014-05-15

    The aim of this paper is to investigate structural changes of high density polyethylene (HDPE) modified by ionizing radiation (gamma rays) in different atmospheres. The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical-chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. This polymer was irradiated with gamma source of {sup 60}Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h. The changes in molecular structure of HDPE, after gamma irradiations were evaluated using thermogravimetric analysis (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere.

  4. Approaching the Minimum Thermal Conductivity in Rhenium-Substituted Higher Manganese Silicides

    SciTech Connect (OSTI)

    Chen, Xi [University of Texas at Austin] [University of Texas at Austin; Girard, S. N. [University of Wisconsin, Madison] [University of Wisconsin, Madison; Meng, F. [University of Wisconsin, Madison] [University of Wisconsin, Madison; Lara-Curzio, Edgar [ORNL] [ORNL; Jin, S [University of Wisconsin, Madison] [University of Wisconsin, Madison; Goodenough, J. B. [University of Texas at Austin] [University of Texas at Austin; Zhou, J. S. [University of Texas at Austin] [University of Texas at Austin; Shi, L [University of Texas at Austin] [University of Texas at Austin

    2014-01-01

    Higher manganese silicides (HMS) made of earth-abundant and non-toxic elements are regarded as promising p-type thermoelectric materials because their complex crystal structure results in low lattice thermal conductivity. It is shown here that the already low thermal conductivity of HMS can be reduced further to approach the minimum thermal conductivity via partial substitu- tion of Mn with heavier rhenium (Re) to increase point defect scattering. The solubility limit of Re in the obtained RexMn1 xSi1.8 is determined to be about x = 0.18. Elemental inhomogeneity and the formation of ReSi1.75 inclusions with 50 200 nm size are found within the HMS matrix. It is found that the power factor does not change markedly at low Re content of x 0.04 before it drops considerably at higher Re contents. Compared to pure HMS, the reduced lattice thermal conductivity in RexMn1 xSi1.8 results in a 25% increase of the peak figure of merit ZT to reach 0.57 0.08 at 800 K for x = 0.04. The suppressed thermal conductivity in the pure RexMn1 xSi1.8 can enable further investigations of the ZT limit of this system by exploring different impurity doping strategies to optimize the carrier concentration and power factor.

  5. Temperature dependence of thermal conductivities of coupled rotator lattice and the momentum diffusion in standard map

    E-Print Network [OSTI]

    Yunyun Li; Nianbei Li; Baowen Li

    2015-01-29

    In contrary to other 1D momentum-conserving lattices such as the Fermi-Pasta-Ulam $\\beta$ (FPU-$\\beta$) lattice, the 1D coupled rotator lattice is a notable exception which conserves total momentum while exhibits normal heat conduction behavior. The temperature behavior of the thermal conductivities of 1D coupled rotator lattice had been studied in previous works trying to reveal the underlying physical mechanism for normal heat conduction. However, two different temperature behaviors of thermal conductivities have been claimed for the same coupled rotator lattice. These different temperature behaviors also intrigue the debate whether there is a phase transition of thermal conductivities as the function of temperature. In this work, we will revisit the temperature dependent thermal conductivities for the 1D coupled rotator lattice. We find that the temperature dependence follows a power law behavior which is different with the previously found temperature behaviors. Our results also support the claim that there is no phase transition for 1D coupled rotator lattice. We also give some discussion about the similarity of diffusion behaviors between the 1D coupled rotator lattice and the single kicked rotator also called the Chirikov standard map.

  6. Calculated transport properties of CdO: thermal conductivity and thermoelectric power factor

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

    Lindsay, Lucas R.; Parker, David S.

    2015-10-01

    We present first principles calculations of the thermal and electronic transport properties of the oxide semiconductor CdO. In particular, we find from theory that the accepted thermal conductivity ? value of 0.7 Wm-1K-1 is approximately one order of magnitude too small; our calculations of ? of CdO are in good agreement with recent measurements. We also find that alloying of MgO with CdO is an effective means to reduce the lattice contribution to ?, despite MgO having a much larger thermal conductivity. We further consider the electronic structure of CdO in relation to thermoelectric performance, finding that large thermoelectric powermore »factors may occur if the material can be heavily doped p-type. This work develops insight into the nature of thermal and electronic transport in an important oxide semiconductor.« less

  7. Pump-probe measurements of the thermal conductivity tensor for materials lacking in-plane symmetry

    SciTech Connect (OSTI)

    Feser, Joseph P. [Department of Mechanical Engineering, University of Delaware, Newark, Delaware 19716 (United States); Liu, Jun; Cahill, David G. [Department of Materials Science and Engineering, and Frederick-Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States)

    2014-10-15

    We previously demonstrated an extension of time-domain thermoreflectance (TDTR) which utilizes offset pump and probe laser locations to measure in-plane thermal transport properties of multilayers. However, the technique was limited to systems of transversely isotropic materials studied using axisymmetric laser intensities. Here, we extend the mathematics so that data reduction can be performed on non-transversely isotropic systems. An analytic solution of the diffusion equation for an N-layer system is given, where each layer has a homogenous but otherwise arbitrary thermal conductivity tensor and the illuminating spots have arbitrary intensity profiles. As a demonstration, we use both TDTR and time-resolved magneto-optic Kerr effect measurements to obtain thermal conductivity tensor elements of <110> ?-SiO{sub 2}. We show that the out-of-phase beam offset sweep has full-width half-maxima that contains nearly independent sensitivity to the in-plane thermal conductivity corresponding to the scanning direction. Also, we demonstrate a Nb-V alloy as a low thermal conductivity TDTR transducer layer that helps improve the accuracy of in-plane measurements.

  8. High Thermal Conductivity Cryogenic RF Feedthroughs for Higher Order Mode Couplers

    SciTech Connect (OSTI)

    Charles Reece; Edward Daly; Thomas Elliott; H. Phillips; Joseph Ozelis; Timothy Rothgeb; Katherine Wilson; Genfa Wu

    2005-05-01

    The use of higher-order-mode (HOM) pickup probes in the presence of significant fundamental RF fields can present a thermal challenge for CW or high average power SRF cavity applications. The electric field probes on the HOM-damping couplers on the JLab ''High Gradient'' (HG) and ''Low Loss'' (LL) seven-cell cavities for the CEBAF upgrade are exposed to approximately 10% of the peak magnetic field in the cavity. To avoid significant dissipative losses, these probes must remain superconducting during operation. Typical cryogenic rf feedthroughs provide a poor thermal conduction path for the probes and provide inadequate stabilization. We have developed solutions that meet the requirements, providing a direct thermal path from the niobium probe, thorough single-crystal sapphire, to bulk copper which can be thermally anchored. Designs, electromagnetic and thermal analyses, and performance data will be presented.

  9. An experimental measurement of the thermal conductivity and diffusivity of a porous solid-liquid system 

    E-Print Network [OSTI]

    Dunn, James Elliott

    1959-01-01

    . 6. The Relation of to SE for Values of K Calculated by the Heat Neter K SE Nethod 10 13 15 17 22 7. The Relation of the Thermal Conductivity of Fluid Saturated Sandstone to the Thermal Conductivity of the Saturating Fluid 8. The Variation... of pressures and temperatures and at flow and non-flow states (3)~(6), (7), The advent of widespread interest in increasing petroleum recovery from subterranean reservoirs by applying heat to an oil-bearing for- mation (8), (9), (10) has created a need...

  10. Predicting Thermal Conductivity Evolution of Polycrystalline Materials Under Irradiation Using Multiscale Approach

    SciTech Connect (OSTI)

    Li, Dongsheng; Li, Yulan; Hu, Shenyang Y.; Sun, Xin; Khaleel, Mohammad A.

    2012-03-01

    A multiscale methodology was developed to predict the evolution of thermal conductivity of polycrystalline fuel under irradiation. In the mesoscale level, phase field model was used to predict the evolution of gas bubble microstructure. Generation of gas atoms and vacancies were taken into consideration. In the macroscopic scale, a statistical continuum mechanics model was applied to predict the anisotropic thermal conductivity evolution during irradiation. Microstructure predicted by phase field model was fed into statistical continuum mechanics model to predict properties and behavior. Influence of irradiation intensity, exposition time and morphology were investigated. This approach provides a deep understanding on microstructure evolution and property prediction from a basic scientific viewpoint.

  11. A robust and well shielded thermal conductivity device for low temperature measurements

    SciTech Connect (OSTI)

    Toews, W. H.; Hill, R. W.

    2014-04-15

    We present a compact mechanically robust thermal conductivity measurement apparatus for measurements at low temperatures (<1 K) and high magnetic fields on small high-purity single crystal samples. A high-conductivity copper box is used to enclose the sample and all the components. The box provides protection for the thermometers, heater, and most importantly the sample increasing the portability of the mount. In addition to physical protection, the copper box is also effective at shielding radio frequency electromagnetic interference and thermal radiation, which is essential for low temperature measurements. A printed circuit board in conjunction with a braided ribbon cable is used to organize the delicate wiring and provide mechanical robustness.

  12. MESO-SCALE MODELING OF THE INFLUENCE OF INTERGRANULAR GAS BUBBLES ON EFFECTIVE THERMAL CONDUCTIVITY

    SciTech Connect (OSTI)

    Paul C. Millett; Michael Tonks

    2011-06-01

    Using a mesoscale modeling approach, we have investigated how intergranular fission gas bubbles, as observed in high-burnup nuclear fuel, modify the effective thermal conductivity in a polycrystalline material. The calculations reveal that intergranular porosity has a significantly higher resistance to heat transfer compared to randomly-distributed porosity. A model is developed to describe this conductivity reduction that considers an effective grain boundary Kapitza resistance as a function of the fractional coverage of grain boundaries by bubbles.

  13. Electron thermal conductivity owing to collisions between degenerate electrons P. S. Shternin and D. G. Yakovlev

    E-Print Network [OSTI]

    Electron thermal conductivity owing to collisions between degenerate electrons P. S. Shternin and D of electrons produced by electron-electron Coulomb scattering in a strongly degenerate electron gas taking in the domain of ultrarelativistic electrons at temperatures below the electron plasma temperature. In the inner

  14. Models of stationary siphon flows in stratified, thermally conducting coronal loops: II Shocked Solutions

    E-Print Network [OSTI]

    Models of stationary siphon flows in stratified, thermally conducting coronal loops: II ­ Shocked to explore the conditions for the presence of stationary shocks in critical and supersonic siphon flows of stationary siphon flows in a semicircular solar coronal loop of constant cross section. The model was based

  15. EFFECTIVE THERMAL CONDUCTIVITY OF LITHIUM CERAMIC PEBBLE BEDS FOR FUSION BLANKETS: A REVIEW

    E-Print Network [OSTI]

    Abdou, Mohamed

    EFFECTIVE THERMAL CONDUCTIVITY OF LITHIUM CERAMIC PEBBLE BEDS FOR FUSION BLANKETS: A REVIEW A. ABOU-1597, ali@fusion.ucla.edu The use of lithium ceramic pebble beds has been considered in many blanket designs for the fusion reactors. Lithium ceramics have received a significant interest as tritium breeders for the fusion

  16. Measurement of the anisotropic thermal conductivity of molybdenum disulfide by the time-resolved magneto-optic Kerr effect

    SciTech Connect (OSTI)

    Liu, Jun Choi, Gyung-Min; Cahill, David G.

    2014-12-21

    We use pump-probe metrology based on the magneto-optic Kerr effect to measure the anisotropic thermal conductivity of (001)-oriented MoS{sub 2} crystals. A ?20?nm thick CoPt multilayer with perpendicular magnetization serves as the heater and thermometer in the experiment. The low thermal conductivity and small thickness of the CoPt transducer improve the sensitivity of the measurement to lateral heat flow in the MoS{sub 2} crystal. The thermal conductivity of MoS{sub 2} is highly anisotropic with basal-plane thermal conductivity varying between 85–110 W?m{sup -1}?K{sup -1} as a function of laser spot size. The basal-plane thermal conductivity is a factor of ?50 larger than the c-axis thermal conductivity, 2.0±0.3?W?m{sup -1}?K{sup -1}.

  17. Thermal conductivity of the one-dimensional Fermi-Hubbard model

    E-Print Network [OSTI]

    C. Karrasch; D. M. Kennes; F. Heidrich-Meisner

    2015-06-18

    We study the thermal conductivity of the one-dimensional Fermi-Hubbard model at finite temperature using a density matrix renormalization group approach. The integrability of this model gives rise to ballistic thermal transport. We calculate the temperature dependence of the thermal Drude weight at half filling for various interactions and moreover, we compute its filling dependence at infinite temperature. The finite-frequency contributions originating from the fact that the energy current is not a conserved quantity are investigated as well. We report evidence that breaking the integrability through a nearest-neighbor interaction leads to vanishing Drude weights and diffusive energy transport. Moreover, we demonstrate that energy spreads ballistically in local quenches with initially inhomogeneous energy density profiles in the integrable case. We discuss the relevance of our results for thermalization in ultra-cold quantum gas experiments and for transport measurements with quasi-one dimensional materials.

  18. Experimental investigation of size effect on thermal conductivity for ultra-thin amorphous poly(methyl methacrylate) (PMMA) films 

    E-Print Network [OSTI]

    Kim, Ick Chan

    2009-05-15

    An investigation was conducted to determine whether a “size effect” phenomenon for one particular thermophysical property, thermal conductivity, actually exists for amorphous poly(methyl methacrylate) (PMMA) films with thicknesses ranging from 40 nm...

  19. Analytical evaluation of thermal conductance and heat capacities of one-dimensional material systems

    SciTech Connect (OSTI)

    Saygi, Salih

    2014-02-15

    We theoretically predict some thermal properties versus temperature dependence of one dimensional (1D) material nanowire systems. A known method is used to provide an efficient and reliable analytical procedure for wide temperature range. Predicted formulas are expressed in terms of Bloch-Grüneisen functions and Debye functions. Computing results has proved that the expressions are in excellent agreement with the results reported in the literature even if it is in very low dimension limits of nanowire systems. Therefore the calculation method is a fully predictive approach to calculate thermal conductivity and heat capacities of nanowire material systems.

  20. Thermal and Electric Conductivities of Coulomb Crystals in the Inner Crust of a Neutron Star

    E-Print Network [OSTI]

    D. A. Baiko; D. G. Yakovlev

    1996-04-28

    Thermal and electric conductivities of relativistic degenerate electrons are calculated for the case when electrons scatter by phonons in Coulomb crystals made of spherical finite--size nuclei at densities $10^{11}$~g/cm$^3 neutron star. In combination with the results of the previous article (for lower $\\rho$), simple unified fits are obtained which describe the kinetic coefficients in the range $10^3$~g/cm$^3 neutron stars and evolution of their magnetic fields. The difference between the kinetic coefficients in the neutron star crust composed of ground state and accreted matters is analyzed. Thermal drift of the magnetic field in the neutron star crust is discussed.

  1. Anomalous pressure dependence of thermal conductivities of large mass ratio compounds

    SciTech Connect (OSTI)

    Lindsay, Lucas R; Broido, David; Carrete, Jesus; Mingo, Natalio; Reinecke, Tom

    2015-01-01

    The lattice thermal conductivities ( ) of binary compound materials are examined as a function of hydrostatic pressure, P, using a first-principles approach. Compound materials with relatively small mass ratios, such as MgO, show an increase in with P, consistent with measurements. Conversely, compounds with large mass ratios (e.g., BSb, BAs, BeTe, BeSe) exhibit decreasing with increasing P, a behavior that cannot be understood using simple theories of . This anomalous P dependence of arises from the fundamentally different nature of the intrinsic scattering processes for heat-carrying acoustic phonons in large mass ratio compounds compared to those with small mass ratios. This work demonstrates the power of first principles methods for thermal properties and advances the understanding of thermal transport in non-metals.

  2. An apparatus for the measurement of thermal conductivity of liquid neon 

    E-Print Network [OSTI]

    Jensen, Jerald Norman

    1967-01-01

    AN APPARATUS FOR THE MEASUREMENT OF THERMAL CONDUCTIVITY OF LIQUID NEON A Thesis By JERALD NORMAN JENSEN Submitted. to the Graduate College of the Texas A & M University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE May 1967 Ma)or Su'bisect: Physics AN APPAHATUS FOH THE J'lEASURENENT OF THEHiiLM CONDUCTIVITY OF LIQUID NEOiV A Thesis JEHALD NOLAN JENSEN Approved as to style and content by: tH *i *f D p tm~t (I"ember) , i~ember Nay 1967 !$ ~c g tg...

  3. Effect of alkali addition on DC conductivity and thermal properties of vanadium-bismo-borate glasses

    SciTech Connect (OSTI)

    Khasa, S., E-mail: skhasa@rediff.com; Dahiya, M. S., E-mail: skhasa@rediff.com [Physics Department, Deenbandhu Chhotu Ram University of Science and Technology, Murthal-131039 (India); Agarwal, A. [Physics Department, Guru Jambheshwara University of Science and Technology, Hisar-125001 (India)

    2014-04-24

    The DC Conductivity and Differential Thermal Analysis of glasses with composition (30?x)Li{sub 2}O?xV{sub 2}O{sub 5}?20Bi{sub 2}O{sub 3}?50B{sub 2}O{sub 3}(x=15, 10, 5) has been carried out in order to study the effect of replacing the Transition Metal Oxide (TMO) with alkali oxide. A significant increase in the DC conductivity has been observed with increase in alkali content. Again the thermal measurements have shown the decrease in both glass transition temperature (T{sub g}) and crystallization temperature (T{sub x}). The Glass Stability (GS) and Glass Forming Ability (GFA) have also been calculated and these also were found to decrease with increase in alkali oxide content at the cost of TMO.

  4. Thermal conductivity studies of novel nanofluids based on metallic silver decorated mesoporous silica nanoparticles

    SciTech Connect (OSTI)

    Tadjarodi, Azadeh; Zabihi, Fatemeh

    2013-10-15

    Graphical abstract: - Highlights: • Metallic silver was decorated in mSiO{sub 2} with grafted hemiaminal functional groups. • Synthesized nanoparticles were used for preparation of glycerol based nanofluids. • The effect of temperature, weight fraction of mSiO{sub 2} and concentration of silver nanoparticles on thermal conductivity of nanofluids was investigated. - Abstract: In the present study, the mesoporous structure of silica (mSiO{sub 2}) nanoparticles as well as hemiaminal grafted mSiO{sub 2} decorated by metallic silver (Ag/mSiO{sub 2}) has been used for the preparation of glycerol based nanofluids. Structural and morphological characterization of the synthesized products have been carried out using Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), UV–vis spectroscopy, inductively coupled plasma (ICP) and N{sub 2} adsorption–desorption isotherms. The thermal conductivity and viscosity of the nanofluids have been measured as a function of temperature for various weight fractions and silver concentrations of mSiO{sub 2} and Ag/mSiO{sub 2} nanoparticles, respectively. The results show that the thermal conductivity of the nanofluids increase up to 9.24% as the weight fraction of mSiO{sub 2} increases up to 4 wt%. Also, increasing the percent of the silver decorated mSiO{sub 2} (Ag/mSiO{sub 2}) up to 2.98% caused an enhancement in the thermal conductivity of the base fluid up to 10.95%. Furthermore, the results show that the nanofluids have Newtonian behavior in the tested temperature range for various concentrations of nanoparticles.

  5. Unglazed transpired solar collector having a low thermal-conductance absorber

    DOE Patents [OSTI]

    Christensen, C.B.; Kutscher, C.F.; Gawlik, K.M.

    1997-12-02

    An unglazed transpired solar collector using solar radiation to heat incoming air for distribution, comprises an unglazed absorber formed of low thermal-conductance material having a front surface for receiving the solar radiation and openings in the unglazed absorber for passage of the incoming air such that the incoming air is heated as it passes towards the front surface of the absorber and the heated air passes through the openings in the absorber for distribution. 3 figs.

  6. High thermal conductivity lossy dielectric using co-densified multilayer configuration

    DOE Patents [OSTI]

    Tiegs, Terry N.; Kiggans, Jr., James O.

    2003-06-17

    Systems and methods are described for loss dielectrics. A method of manufacturing a lossy dielectric includes providing at least one high dielectric loss layer and providing at least one high thermal conductivity-electrically insulating layer adjacent the at least one high dielectric loss layer and then densifying together. The systems and methods provide advantages because the lossy dielectrics are less costly and more environmentally friendly than the available alternatives.

  7. Unglazed transpired solar collector having a low thermal-conductance absorber

    DOE Patents [OSTI]

    Christensen, Craig B. (Boulder, CO); Kutscher, Charles F. (Golden, CO); Gawlik, Keith M. (Boulder, CO)

    1997-01-01

    An unglazed transpired solar collector using solar radiation to heat incoming air for distribution, comprising an unglazed absorber formed of low thermal-conductance material having a front surface for receiving the solar radiation and openings in the unglazed absorber for passage of the incoming air such that the incoming air is heated as it passes towards the front surface of the absorber and the heated air passes through the openings in the absorber for distribution.

  8. PHYSICAL REVIEW B 84, 054203 (2011) Electrical and thermal conductivity of liquid sodium from first-principles calculations

    E-Print Network [OSTI]

    Alfè, Dario

    2011-01-01

    and technological point of view. For example, it is used as coolant in fast-breeding nuclear reactors, and in heatPHYSICAL REVIEW B 84, 054203 (2011) Electrical and thermal conductivity of liquid sodium from first on the electrical and thermal conductivity of liquid sodium at 400 K, calculated using density functional theory

  9. E. In Situ Polymerization of Cyclic Butylene Terephthalate(CBT) Oligomers with Conductive fillers for Thermal Management

    E-Print Network [OSTI]

    Harmon, Julie P.

    copolymers with Thermal conductivity Composites This research is funded by Honeywell Corporation. For the generous assistance in measuring thermal conductivities of our composites. The original purpose% diamond composites, tested by Cool Polymer, Inc. in #12;Warwick. Cool Polymers measured a value of 4.21 W

  10. ELECTRON THERMAL CONDUCTION AS A POSSIBLE PHYSICAL MECHANISM TO MAKE THE INNER HELIOSHEATH THINNER

    SciTech Connect (OSTI)

    Izmodenov, V. V. [Department of Mechanics and Mathematics, Lomonosov Moscow State University, 1 Leninskie gory, Moscow, 119991 (Russian Federation); Alexashov, D. B.; Ruderman, M. S., E-mail: izmod@ipmnet.ru [Space Research Institute (IKI) of Russian Academy of Sciences, 84/32 Profsoyuznaya Street, Moscow, 117997 (Russian Federation)

    2014-11-01

    We show that electron thermal conductivity may strongly affect the heliosheath plasma flow and the global pattern of the solar wind's interaction with the local interstellar medium. In particular, it leads to strong reduction of the inner heliosheath thickness, which makes it possible to explain (qualitatively) why Voyager 1 (V1) has crossed the heliopause at an unexpectedly small heliocentric distance of 122 AU. To estimate the effect of thermal conductivity, we consider a limiting case when thermal conduction is very effective. To do that, we assume the plasma flow in the entire heliosphere is nearly isothermal. Due to this effect, the heliospheric distance of the termination shock has increased by about 15 AU in the V1 direction compared with the adiabatic case with ? = 5/3. The heliospheric distance of the heliopause has decreased by about 27 AU. As a result, the thickness of the inner heliosheath in the model has decreased by about 42 AU and has become equal to 32 AU.

  11. Unusual Enhancement in Intrinsic Thermal Conductivity of Multilayer Graphene by Tensile Strains

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

    Kuang, Youdi; Lindsay, Lucas R.; Huang, Baoling

    2015-01-01

    High basal plane thermal conductivity k of multi-layer graphene makes it promising for thermal management applications. Here we examine the effects of tensile strain on thermal transport in this system. Using a first principles Boltzmann-Peierls equation for phonon transport approach, we calculate the room-temperature in-plane lattice k of multi-layer graphene (up to four layers) and graphite under different isotropic tensile strains. The calculated in-plane k of graphite, finite mono-layer graphene and 3-layer graphene agree well with previous experiments. The dimensional transitions of the intrinsic k and the extent of the diffusive transport regime from mono-layer graphene to graphite are presented.more »We find a peak enhancement of intrinsic k for multi-layer graphene and graphite with increasing strain and the largest enhancement amplitude is about 40%. In contrast the calculated intrinsic k with tensile strain decreases for diamond and diverges for graphene, we show that the competition between the decreased mode heat capacities and the increased lifetimes of flexural phonons with increasing strain contribute to this k behavior. Similar k behavior is observed for 2-layer hexagonal boron nitride systems, suggesting that it is an inherent thermal transport property in multi-layer systems assembled of purely two dimensional atomic layers. This study provides insights into engineering k of multi-layer graphene and boron nitride by strain and into the nature of thermal transport in quasi-two-dimensional and highly anisotropic systems.« less

  12. Unusual Enhancement in Intrinsic Thermal Conductivity of Multilayer Graphene by Tensile Strains

    SciTech Connect (OSTI)

    Kuang, Youdi [Hong Kong Univ. of Science and Technology (Hong Kong); Lindsay, Lucas R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Huang, Baoling [Hong Kong Univ. of Science and Technology (Hong Kong)

    2015-01-01

    High basal plane thermal conductivity k of multi-layer graphene makes it promising for thermal management applications. Here we examine the effects of tensile strain on thermal transport in this system. Using a first principles Boltzmann-Peierls equation for phonon transport approach, we calculate the room-temperature in-plane lattice k of multi-layer graphene (up to four layers) and graphite under different isotropic tensile strains. The calculated in-plane k of graphite, finite mono-layer graphene and 3-layer graphene agree well with previous experiments. The dimensional transitions of the intrinsic k and the extent of the diffusive transport regime from mono-layer graphene to graphite are presented. We find a peak enhancement of intrinsic k for multi-layer graphene and graphite with increasing strain and the largest enhancement amplitude is about 40%. In contrast the calculated intrinsic k with tensile strain decreases for diamond and diverges for graphene, we show that the competition between the decreased mode heat capacities and the increased lifetimes of flexural phonons with increasing strain contribute to this k behavior. Similar k behavior is observed for 2-layer hexagonal boron nitride systems, suggesting that it is an inherent thermal transport property in multi-layer systems assembled of purely two dimensional atomic layers. This study provides insights into engineering k of multi-layer graphene and boron nitride by strain and into the nature of thermal transport in quasi-two-dimensional and highly anisotropic systems.

  13. Magneto thermal conductivity of superconducting Nb with intermediate level of impurity

    SciTech Connect (OSTI)

    L.S. Sharath Chandra, M.K. Chattopadhyay, S.B. Roy, V.C. Sahni, G.R. Myneni

    2012-03-01

    Niobium materials with intermediate purity level are used for fabrication of superconducting radio frequency cavities (SCRF), and thermal conductivity is an important parameter influencing the performance of such SCRF cavities. We report here the temperature and magnetic field dependence of thermal conductivity {kappa} for superconducting niobium (Nb) samples, for which the electron mean free path I{sub e}, the phonon mean free path I{sub g}, and the vortex core diameter 2r{sub C} are of the same order of magnitude. The measured thermal conductivity is analyzed using the effective gap model (developed for I{sub e} >> 2r{sub C} (Dubeck et al 1963 Phys. Rev. Lett. 10 98)) and the normal core model (developed for I{sub e} << 2r{sub C} (Ward and Dew-Hughes 1970 J. Phys. C: Solid St. Phys. 3 2245)). However, it is found that the effective gap model is not suitable for low temperatures when I{sub e} {approx} 2r{sub C}. The normal core model, on the other hand, is able to describe {kappa}(T,H) over the entire temperature range except in the field regime between H{sub C1} and H{sub C2} i.e. in the mixed state. It is shown that to understand the complete behavior of {kappa} in the mixed state, the scattering of quasi-particles from the vortex cores and the intervortex quasi-particle tunneling are to be invoked. The quasi-particle scattering from vortices for the present system is understood in terms of the framework of Sergeenkov and Ausloos (1995 Phys. Rev. B 52 3614) extending their approach to the case of Nb. The intervortex tunneling is understood within the framework of Schmidbauer et al (1970 Z. Phys. 240 30). Analysis of the field dependence of thermal conductivity shows that while the quasi-particle scattering from vortices dominates in the low fields, the intervortex quasi-particle tunneling dominates in high fields. Analysis of the temperature dependence of thermal conductivity shows that while the quasi-particle scattering is dominant at low temperatures, the intervortex quasi-particle tunneling is dominant at high temperatures.

  14. Determination of temperature-dependent heat conductivity and thermal diffusivity of waste glass melter feed

    SciTech Connect (OSTI)

    Pokorny, Richard; Rice, Jarrett A.; Schweiger, Michael J.; Hrma, Pavel R.

    2013-06-01

    The cold cap is a layer of reacting glass batch floating on the surface of melt in an all-electric continuous glass melter. The heat needed for the conversion of the melter feed to molten glass must be transferred to and through the cold cap. Since the heat flux into the cold cap determines the rate of melting, the heat conductivity is a key property of the reacting feed. We designed an experimental setup consisting of a large cylindrical crucible with an assembly of thermocouples that monitors the evolution of the temperature field while the crucible is heated at a constant rate. Then we used two methods to calculate the heat conductivity and thermal diffusivity of the reacting feed: the approximation of the temperature field by polynomial functions and the finite-volume method coupled with least-squares analysis. Up to 680°C, the heat conductivity of the reacting melter feed was represented by a linear function of temperature.

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

    SciTech Connect (OSTI)

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

    2014-05-01

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

  16. Silica Supported Single-Walled Carbon Nanotubes as a Modifier in Polyethylene Composites

    E-Print Network [OSTI]

    Resasco, Daniel

    Silica Supported Single-Walled Carbon Nanotubes as a Modifier in Polyethylene Composites Neal D. Mc.interscience.wiley.com). ABSTRACT: Composites have been made from single- wall carbon nanotubes in a polyethylene (PE) matrix: additives; composites; conducting polymers; nanocomposites; polyethylene INTRODUCTION Polyethylene (PE

  17. R. SCHUMANNand K. ELK:Thermal Conductivity of the Periodic Anderson Model 221 phys. stat. sol. (b)119, 221 (1983)

    E-Print Network [OSTI]

    Schumann, Rolf

    1983-01-01

    using the alloy-analogy approximation. Then the energy-dependent conductivity u(o)is obtained from the thermopower S and the thermal conductivity ~tis calculated starting with the energy-dependent conductivity a, of this distribution can be evaluated [l],according to +co -co l) PSI? 103, DDR-8072 Dresden, GDR. #12;222 R

  18. Thermal interface conductance across a graphene/hexagonal boron nitride heterojunction

    SciTech Connect (OSTI)

    Chen, Chun-Chung; Li, Zhen; Cronin, Stephen B. [Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089 (United States); Shi, Li [Department of Mechanical Engineering and Texas Materials Institute, University of Texas at Austin, Austin, Texas 78712 (United States)

    2014-02-24

    We measure thermal transport across a graphene/hexagonal boron nitride (h-BN) interface by electrically heating the graphene and measuring the temperature difference between the graphene and BN using Raman spectroscopy. Because the temperature of the graphene and BN are measured optically, this approach enables nanometer resolution in the cross-plane direction. A temperature drop of 60?K can be achieved across this junction at high electrical powers (14 mW). Based on the temperature difference and the applied power data, we determine the thermal interface conductance of this junction to be 7.4?×?10{sup 6}?Wm{sup ?2}K{sup ?1}, which is below the 10{sup 7}–10{sup 8}?Wm{sup ?2}K{sup ?1} values previously reported for graphene/SiO{sub 2} interface.

  19. Polyethylene fiber drawing optimization

    E-Print Network [OSTI]

    Chiloyan, Vazrik

    2011-01-01

    Polymer fiber drawing creates fibers with enhanced thermal conductivity and strength compared to bulk polymer because drawing aligns the molecular chains. I optimize the polymer fiber drawing method in order to achieve ...

  20. Subsurface Temperature, Moisture, Thermal Conductivity and Heat Flux, Barrow, Area A, B, C, D

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Cable, William; Romanovsky, Vladimir

    Subsurface temperature data are being collected along a transect from the center of the polygon through the trough (and to the center of the adjacent polygon for Area D). Each transect has five 1.5m vertical array thermistor probes with 16 thermistors each. This dataset also includes soil pits that have been instrumented for temperature, water content, thermal conductivity, and heat flux at the permafrost table. Area C has a shallow borehole of 2.5 meters depth is instrumented in the center of the polygon.

  1. Subsurface Temperature, Moisture, Thermal Conductivity and Heat Flux, Barrow, Area A, B, C, D

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Cable, William; Romanovsky, Vladimir

    2014-03-31

    Subsurface temperature data are being collected along a transect from the center of the polygon through the trough (and to the center of the adjacent polygon for Area D). Each transect has five 1.5m vertical array thermistor probes with 16 thermistors each. This dataset also includes soil pits that have been instrumented for temperature, water content, thermal conductivity, and heat flux at the permafrost table. Area C has a shallow borehole of 2.5 meters depth is instrumented in the center of the polygon.

  2. Thermal conductivity in large-J two-dimensional antiferromagnets: Role of phonon scattering

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

    Chernyshev, A. L.; Brenig, Wolfram

    2015-08-05

    Different types of relaxation processes for magnon heat current are discussed, with a particular focus on coupling to three-dimensional phonons. There is thermal conductivity by these in-plane magnetic excitations using two distinct techniques: Boltzmann formalism within the relaxation-time approximation and memory-function approach. Also considered are the scattering of magnons by both acoustic and optical branches of phonons. We demonstrate an accord between the two methods, regarding the asymptotic behavior of the effective relaxation rates. It is strongly suggested that scattering from optical or zone-boundary phonons is important for magnon heat current relaxation in a high-temperature window of ?D?Tmore »« less

  3. Gold-titania interface toughening and thermal conductance enhancement using an organophosphonate nanolayer

    SciTech Connect (OSTI)

    Chow, Philippe K.; O'Brien, Peter; Ramanath, Ganpati; Cardona Quintero, Y.; Ramprasad, R.; Hubert Mutin, P.; Lane, Michael

    2013-05-20

    We demonstrate that a mercaptan-terminated organophosphonate nanolayer at gold-titania interfaces can give rise to two- to three-fold enhancement in the interfacial fracture toughness and thermal conductance. Electron spectroscopy reveals that interfacial delamination occurs at the metal-molecule interface near the gold-sulfur bonds, consistent with density functional theory calculations of bond energies. Qualitative correlation between interfacial fracture toughness and bond energies suggest that organophosphonate nanolayers are resilient to humidity-induced degradation. These results, and the versatility of organophosphonates as surface functionalization agents for technologically relevant materials, unlock uncharted avenues for molecular engineering of interfaces in materials and devices for a variety of applications.

  4. Thermal Conductivity Enhancement of High Temperature Phase Change Materials for Concentrating Solar Power Plant Applications

    E-Print Network [OSTI]

    Roshandell, Melina

    2013-01-01

    been considered for solar thermal energy storages. These areTNO Symposium on Thermal Storage of Solar Energy, Amsterdam,Symposium on Thermal Application of Solar Energy, Hakone (

  5. Thermal Conductivity Enhancement of High Temperature Phase Change Materials for Concentrating Solar Power Plant Applications

    E-Print Network [OSTI]

    Roshandell, Melina

    2013-01-01

    energy storage system; thermal storage and heat transfer in1308. 32- Telkes, M. Thermal storage for solar heating andeditor. Phase change thermal storage materials. McGraw Hill

  6. Thermal Conductivity Enhancement of High Temperature Phase Change Materials for Concentrating Solar Power Plant Applications

    E-Print Network [OSTI]

    Roshandell, Melina

    2013-01-01

    materials (PCM) in solar thermal concentrating technologyeffective and efficient solar thermal electricity generatorbeen considered for solar thermal energy storages. These are

  7. Thermal Conductivity Enhancement of High Temperature Phase Change Materials for Concentrating Solar Power Plant Applications

    E-Print Network [OSTI]

    Roshandell, Melina

    2013-01-01

    been considered for solar thermal energy storages. These arePCMs for thermal energy storage in solar driven residentialfluid and thermal energy storage medium in the solar heat

  8. Preparation of silica aerogels with improved mechanical properties and extremely low thermal conductivities through modified sol-gel process

    E-Print Network [OSTI]

    Zuo, Yanjia

    2010-01-01

    Reported silica aerogels have a thermal conductivity as low as 15 mW/mK. The fragility of silica aerogels, however, makes them impractical for structural applications. The purpose of the study is to improve the ductility ...

  9. Nonlinear vs. bolometric radiation response and phonon thermal conductance in graphene-superconductor junctions

    SciTech Connect (OSTI)

    Vora, Heli; Nielsen, Bent; Du, Xu [Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York (United States)

    2014-02-21

    Graphene is a promising candidate for building fast and ultra-sensitive bolometric detectors due to its weak electron-phonon coupling and low heat capacity. In order to realize a practical graphene-based bolometer, several important issues, including the nature of radiation response, coupling efficiency to the radiation and the thermal conductance need to be carefully studied. Addressing these issues, we present graphene-superconductor junctions as a viable option to achieve efficient and sensitive bolometers, with the superconductor contacts serving as hot electron barriers. For a graphene-superconductor device with highly transparent interfaces, the resistance readout in the presence of radio frequency radiation is dominated by non-linear response. On the other hand, a graphene-superconductor tunnel device shows dominantly bolometric response to radiation. For graphene devices fabricated on SiO{sub 2} substrates, we confirm recent theoretical predictions of T{sup 2} temperature dependence of phonon thermal conductance in the presence of disorder in the graphene channel at low temperatures.

  10. Colloidal graphite/graphene nanostructures using collagen showing enhanced thermal conductivity

    E-Print Network [OSTI]

    Soumya Bhattacharya; Purbarun Dhar; Sarit K Das; Ranjan Ganguly; Thomas Webster; Suprabha Nayar

    2015-11-27

    Time kinetics of interaction of natural graphite (GR) to colloidal graphene (G) collagen (C) nanocomposites was studied at ambient conditions, and observed that just one day at ambient conditions is enough to form colloidal graphene directly from graphite using the protein collagen. Neither controlled temperature and pressure ambiance nor sonication was needed for the same; thereby rendering the process biomimetic. Detailed spectroscopy, X ray diffraction, electron microscopy as well as fluorescence and luminescence assisted characterization of the colloidal dispersions on day one and day seven reveals graphene and collagen interaction and subsequent rearrangement to form an open structure. Detailed confocal microscopy, in the liquid state, reveals the initial attack at the zigzag edges of GR, the enhancement of auto fluorescence and finally the opening up of graphitic stacks of GR to form near transparent G. Atomic Force Microscopy studies prove the existence of both collagen and graphene and the disruption of periodicity at the atomic level. Thermal conductivity of the colloid shows a 17% enhancement for a volume fraction of less than 0.00005 of G. Time variant increase in thermal conductivity provides qualitative evidence for the transient exfoliation of GR to G. The composite reveals interesting properties that could propel it as a future material for advanced bio applications including therapeutics.

  11. Polyethylene composites containing a phase change material having a C14 straight chain hydrocarbon

    DOE Patents [OSTI]

    Salyer, Ival O. (Dayton, OH)

    1987-01-01

    A composite useful in thermal energy storage, said composite being formed of a polyethylene matrix having a straight chain alkyl hydrocarbon incorporated therein, said polyethylene being crosslinked to such a degree that said polyethylene matrix is form stable and said polyethylene matrix is capable of absorbing at least 10% by weight of said straight chain alkyl hydrocarbon; the composite is useful in forming pellets or sheets having thermal energy storage characteristics.

  12. Oxidation of Metals, Vol. 61, Nos. 3/4, April 2004 ( 2004) Thermal Conductivity, Phase Stability, and Oxidation

    E-Print Network [OSTI]

    Trice, Rodney W.

    . INTRODUCTION Thermal-barrier coatings (TBCs) have been used to protect gas-turbine- engine components since, and Oxidation Resistance of Y3Al5O12 (YAG)/Y2O3­ZrO2 (YSZ) Thermal-Barrier Coatings Y. J. Su, R. W. Trice,# K­aluminum garnet (YAG) into a typical YSZ TBC system. The thermal conductivity of as-sprayed YAG/YSZ coatings

  13. An experimental investigation of thermal contact conductance across carbon fiber/epoxy resin composites as a function of interface pressure 

    E-Print Network [OSTI]

    Rhoades, Michael Everett

    1989-01-01

    &M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1989 Major Subject: Mechanical Engineering AN EXPERIMENTAL INVESTIGATION OF THERMAL CONTACT CONDUCTANCE ACROSS CARBON FIBER/EPOXY RESIN COMPOSITES AS A... This work investigates thermal contact conductance across carbon fiber/epoxy resin composites at discrete contact pressures. Samples with unidirectional, continuous fibers oriented at zero and ninety degrees to the contact interface are analyzed in 90...

  14. Accepted by the Journal of Building Physics (2007) Microstructure and Thermal Conductivity of Hydrated Calcium Silicate Board Materials

    E-Print Network [OSTI]

    Bentz, Dale P.

    2007-01-01

    and an assessment of pore size based on scanning electron microscopy. The experimentally measured thermal components and their spatial arrangement within the composite structure, e.g., the material's microstructure and pore size are examined for two calcium silicate boards of different densities. Thermal conductivities

  15. PHYSICAL REVIEW B 85, 184201 (2012) Electrical and thermal conductivity of Al liquid at high pressures and temperatures

    E-Print Network [OSTI]

    Steinle-Neumann, Gerd

    2012-01-01

    perturbation theory to phase trajectories generated using first-principles molecular dynamics. Our results time-invariant electrical field and thermal gradient. First-principles calculations provide a directPHYSICAL REVIEW B 85, 184201 (2012) Electrical and thermal conductivity of Al liquid at high

  16. Impacts of Soil and Pipe Thermal Conductivity on Performance of Horizontal Pipe in a Ground-source Heat Pump 

    E-Print Network [OSTI]

    Song, Y.; Yao, Y.; Na, W.

    2006-01-01

    In this paper the composition and thermal property of soil are discussed. The main factors that impact the soil thermal conductivity and several commonly-used pipe materials are studied. A model of heat exchanger with horizontal pipes of ground-source...

  17. Ground surface temperature reconstructions: Using in situ estimates for thermal conductivity acquired with a fiber-optic distributed thermal perturbation sensor

    SciTech Connect (OSTI)

    Freifeld, B.M.; Finsterle, S.; Onstott, T.C.; Toole, P.; Pratt, L.M.

    2008-10-10

    We have developed a borehole methodology to estimate formation thermal conductivity in situ with a spatial resolution of one meter. In parallel with a fiber-optic distributed temperature sensor (DTS), a resistance heater is deployed to create a controlled thermal perturbation. The transient thermal data is inverted to estimate the formation's thermal conductivity. We refer to this instrumentation as a Distributed Thermal Perturbation Sensor (DTPS), given the distributed nature of the DTS measurement technology. The DTPS was deployed in permafrost at the High Lake Project Site (67 degrees 22 minutes N, 110 degrees 50 minutes W), Nunavut, Canada. Based on DTPS data, a thermal conductivity profile was estimated along the length of a wellbore. Using the thermal conductivity profile, the baseline geothermal profile was then inverted to estimate a ground surface temperature history (GSTH) for the High Lake region. The GSTH exhibits a 100-year long warming trend, with a present-day ground surface temperature increase of 3.0 {+-} 0.8 C over the long-term average.

  18. Determination of heat conductivity and thermal diffusivity of waste glass melter feed: Extension to high temperatures

    SciTech Connect (OSTI)

    Rice, Jarrett A. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Pokorny, Richard [Inst. of Chemical Technology, Prague (Czech Republic); Schweiger, Michael J. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Hrma, Pavel R. [Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Pohang Univ. of Science and Technology (Korea, Republic of)

    2014-06-01

    The heat conductivity ({lambda}) and the thermal diffusivity (a) of reacting glass batch, or melter feed, control the heat flux into and within the cold cap, a layer of reacting material floating on the pool of molten glass in an all-electric continuous waste glass melter. After previously estimating {lambda} of melter feed at temperatures up to 680 deg C, we focus in this work on the {lambda}(T) function at T > 680 deg C, at which the feed material becomes foamy. We used a customized experimental setup consisting of a large cylindrical crucible with an assembly of thermocouples, which monitored the evolution of the temperature field while the crucible with feed was heated at a constant rate from room temperature up to 1100°C. Approximating measured temperature profiles by polynomial functions, we used the heat transfer equation to estimate the {lambda}(T) approximation function, which we subsequently optimized using the finite-volume method combined with least-squares analysis. The heat conductivity increased as the temperature increased until the feed began to expand into foam, at which point the conductivity dropped. It began to increase again as the foam turned into a bubble-free glass melt. We discuss the implications of this behavior for the mathematical modeling of the cold cap.

  19. On linearization and preconditioning for radiation diffusion coupled to material thermal conduction equations

    SciTech Connect (OSTI)

    Feng, Tao, E-mail: fengtao2@mail.ustc.edu.cn [School of Mathematical Sciences, University of Science and Technology of China, Hefei 230052 (China) [School of Mathematical Sciences, University of Science and Technology of China, Hefei 230052 (China); Graduate School of China Academy Engineering Physics, Beijing 100083 (China); An, Hengbin, E-mail: an_hengbin@iapcm.ac.cn [National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)] [National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Yu, Xijun, E-mail: yuxj@iapcm.ac.cn [National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China)] [National Key Laboratory of Computational Physics, Institute of Applied Physics and Computational Mathematics, Beijing 100094 (China); Li, Qin, E-mail: liqin@lsec.cc.ac.cn [Chinese Academy of Mathematics and Systems Science, Beijing 100190 (China)] [Chinese Academy of Mathematics and Systems Science, Beijing 100190 (China); Zhang, Rongpei, E-mail: zhangrongpei@163.com [Graduate School of China Academy Engineering Physics, Beijing 100083 (China)] [Graduate School of China Academy Engineering Physics, Beijing 100083 (China)

    2013-03-01

    Jacobian-free Newton–Krylov (JFNK) method is an effective algorithm for solving large scale nonlinear equations. One of the most important advantages of JFNK method is that there is no necessity to form and store the Jacobian matrix of the nonlinear system when JFNK method is employed. However, an approximation of the Jacobian is needed for the purpose of preconditioning. In this paper, JFNK method is employed to solve a class of non-equilibrium radiation diffusion coupled to material thermal conduction equations, and two preconditioners are designed by linearizing the equations in two methods. Numerical results show that the two preconditioning methods can improve the convergence behavior and efficiency of JFNK method.

  20. Lattice Anharmonicity and Thermal Conductivity from Compressive Sensing of First-Principles Calculations

    SciTech Connect (OSTI)

    Zhou, Fei; Nielson, Weston; Xia, Yi; Ozoli?š, Vidvuds

    2014-10-01

    First-principles prediction of lattice thermal conductivity ?L of strongly anharmonic crystals is a long-standing challenge in solid-state physics. Making use of recent advances in information science, we propose a systematic and rigorous approach to this problem, compressive sensing lattice dynamics. Compressive sensing is used to select the physically important terms in the lattice dynamics model and determine their values in one shot. Nonintuitively, high accuracy is achieved when the model is trained on first-principles forces in quasirandom atomic configurations. The method is demonstrated for Si, NaCl, and Cu12Sb4S13, an earth-abundant thermoelectric with strong phonon-phonon interactions that limit the room-temperature ?L to values near the amorphous limit.

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

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

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

    2012-11-29

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

  2. Method of making improved gas storage carbon with enhanced thermal conductivity

    DOE Patents [OSTI]

    Burchell, Timothy D. (Oak Ridge, TN); Rogers, Michael R. (Knoxville, TN)

    2002-11-05

    A method of making an adsorbent carbon fiber based monolith having improved methane gas storage capabilities is disclosed. Additionally, the monolithic nature of the storage carbon allows it to exhibit greater thermal conductivity than conventional granular activated carbon or powdered activated carbon storage beds. The storage of methane gas is achieved through the process of physical adsorption in the micropores that are developed in the structure of the adsorbent monolith. The disclosed monolith is capable of storing greater than 150 V/V of methane [i.e., >150 STP (101.325 KPa, 298K) volumes of methane per unit volume of storage vessel internal volume] at a pressure of 3.5 MPa (500 psi).

  3. Thermal and Electric Conductivities of Coulomb Crystals in Neutron Stars and White Dwarfs

    E-Print Network [OSTI]

    D. A. Baiko; D. G. Yakovlev

    1996-04-28

    Thermal and electric conductivities are calculated for degenerate electrons scattered by phonons in a crystal made of atomic nuclei. The exact phonon spectrum and the Debye--Waller factor are taken into account. Monte Carlo calculations are performed for body-centered cubic (bcc) crystals made of C, O, Ne, Mg, Si, S, Ca, and Fe nuclei in the density range from $10^3$ to $10^{11}$ g cm$^{-3}$ at temperatures lower than the melting temperature but higher than the temperature at which the Umklapp processes begin to be "frozen out". A simplified method of calculation is proposed, which makes it possible to describe the results in terms of simple analytic expressions, to extend these expressions to any species of nucleus, and to consider face-centered cubic (fcc) crystals. The kinetic coefficients are shown to depend tangibly on the lattice type. The results are applicable to studies of heat transfer and evolution of the magnetic field in the cores of white dwarfs and in the crusts of neutron stars. The thermal drift of the magnetic field in the crust of a neutron star is discussed.

  4. Density dependence of the room temperature thermal conductivity of atomic layer deposition-grown amorphous alumina (Al{sub 2}O{sub 3})

    SciTech Connect (OSTI)

    Gorham, Caroline S.; Gaskins, John T.; Hopkins, Patrick E.; Parsons, Gregory N.; Losego, Mark D.

    2014-06-23

    We report on the thermal conductivity of atomic layer deposition-grown amorphous alumina thin films as a function of atomic density. Using time domain thermoreflectance, we measure the thermal conductivity of the thin alumina films at room temperature. The thermal conductivities vary ?35% for a nearly 15% change in atomic density and are substrate independent. No density dependence of the longitudinal sound speeds is observed with picosecond acoustics. The density dependence of the thermal conductivity agrees well with a minimum limit to thermal conductivity model that is modified with a differential effective-medium approximation.

  5. Design of a steady state thermal conductivity measurement device for CNT RET polymer composites

    E-Print Network [OSTI]

    Louie, Brian Ming

    2011-01-01

    conductive particles along with CNTs in polymer composites.polymer composites. 2,12 The combination of highly conductive

  6. ROTATING SOLAR JETS IN SIMULATIONS OF FLUX EMERGENCE WITH THERMAL CONDUCTION

    SciTech Connect (OSTI)

    Fang, Fang; Fan, Yuhong; McIntosh, Scott W.

    2014-07-01

    We study the formation of coronal jets through numerical simulation of the emergence of a twisted magnetic flux rope into a pre-existing open magnetic field. Reconnection inside the emerging flux rope in addition to that between the emerging and pre-existing fields give rise to the violent eruption studied. The simulated event closely resembles the coronal jets ubiquitously observed by the X-Ray Telescope on board Hinode and demonstrates that heated plasma is driven into the extended atmosphere above. Thermal conduction implemented in the model allows us to qualitatively compare simulated and observed emission from such events. We find that untwisting field lines after the reconnection drive spinning outflows of plasma in the jet column. The Poynting flux in the simulated jet is dominated by the untwisting motions of the magnetic fields loaded with high-density plasma. The simulated jet is comprised of ''spires'' of untwisting field that are loaded with a mixture of cold and hot plasma and exhibit rotational motion of order 20 km s{sup –1} and match contemporary observations.

  7. Electrical and thermal conductivities of reduced graphene oxide/polystyrene Wonjun Park, Jiuning Hu, Luis A. Jauregui, Xiulin Ruan, and Yong P. Chen

    E-Print Network [OSTI]

    Chen, Yong P.

    conductive polymer composites are used as heat sinks for device packaging requiring a high thermalElectrical and thermal conductivities of reduced graphene oxide/polystyrene composites Wonjun Park. The electrical conductivity (r) of RGO/PS composites with different RGO concentrations at room temperature shows

  8. Measurements of the apparent thermal conductivity of multi-layer insulation between 20 K and 90 K

    SciTech Connect (OSTI)

    Hurd, Joseph A.; Van Sciver, Steven W.

    2014-01-29

    NASA has the need to efficiently store cryogenic propellants in space for long periods of time. One method to improve storage efficiency is to use multi-layer insulation (MLI), a technique that minimizes the boiling rate due to radiation heat transfer. Typically, the thermal performance of MLI is determined by measuring the rate of evaporation of liquid nitrogen from a calibrated cryostat. The main limitation with this method is that testing conditions are restricted by the boiling temperature of the LN{sub 2}, which may not match the requirements of the application. The Multi-Layer Insulation Thermal Conductivity Experiment (MIKE) at the National High Magnetic Field Laboratory is capable of measuring the effective thermal conductivity of MLI at variable boundary temperatures. MIKE uses cryo-refrigerators to control boundary temperatures in the calorimeter and a calibrated thermal link to measure the heat load. To make the measurements requested by NASA, MIKE needed to be recalibrated for the 20 K to 90 K range. Also, due to the expectation of a lower heat transfer rate, the heat load support rod material was changed to one with a lower thermal conductivity to ensure the temperature difference seen on the cold rod could be measurable at the estimated heat load. Presented are the alterations to MIKE including calibration data and heat load measurements on new load-bearing MLI supplied by NASA.

  9. Polymer Composites with Enhanced Thermal Conductivity: This research is funded by Honeywell Corporation and the Florida High Tech Corridor.

    E-Print Network [OSTI]

    Harmon, Julie P.

    Corporation and the Florida High Tech Corridor. The purpose is to develop polymeric composites used as underfills in fiber optic gyros. The composites must exhibit high thermal conductivity (TC), cure. This eliminates a significant problem encountered with epoxy systems, since, high polymerization exotherms destroy

  10. Superior thermoelectric performance in PbTe-PbS pseudo-binary. Extremely low thermal conductivity and modulated carrier concentration

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

    Wu, D.; Zhao, L. -D.; Tong, X.; Li, W.; Wu, L.; Tan, Q.; Pei, Y.; Huang, L.; Li, J. -F.; Zhu, Y.; et al

    2015-05-19

    Lead chalcogenides have exhibited their irreplaceable role as thermoelectric materials at the medium temperature range, owing to highly degenerate electronic bands and intrinsically low thermal conductivities. PbTe-PbS pseudo-binary has been paid extensive attentions due to the even lower thermal conductivity which originates largely from the coexistence of both alloying and phase-separated precipitations. To investigate the competition between alloying and phase separation and its pronounced effect on the thermoelectric performance in PbTe-PbS, we systematically studied Spark Plasma Sintered (SPSed), 3 at% Na- doped (PbTe)1-x(PbS)x samples with x=10%, 15%, 20%, 25%, 30% and 35% by means of transmission electron microscopy (TEM) observationsmore »and theoretical calculations. Corresponding to the lowest lattice thermal conductivity as a result of the balance between point defect- and precipitates- scattering, the highest figure of merit ZT~2.3 was obtained at 923 K when PbS phase fraction x is at 20%. The consistently lower lattice thermal conductivities in SPSed samples compared with corresponding ingots, resulting from the powdering and follow-up consolidation processes, also contribute to the observed superior ZT. Notably, the onset of carrier concentration modulation ~600 K due to excessive Na’s diffusion and re-dissolution leads to the observed saturations of electrical transport properties, which is believed equally crucial to the outstanding thermoelectric performance of SPSed PbTe-PbS samples.« less

  11. High Thermal Conductivity UO2-BeO Nulcear Fuel: Neutronic Performance Assessments and Overview of Fabrication 

    E-Print Network [OSTI]

    Naramore, Michael J

    2010-08-03

    is very prominent and porosity helps alleviate internal pressures to reduce fuel deformation. Therefore, a balance between thermal conductivity and fission gas accommodation is necessary to achieve a long lasting fuel [4]. 4> F c.> ::>oz 00 c.> 3 -l F...................................................................................................................78 APPENDIX G ..................................................................................................................82...

  12. Thermal conductivity of single-walled carbon nanotubes J. Hone, M. Whitney, C. Piskoti, and A. Zettl

    E-Print Network [OSTI]

    Zettl, Alex

    with a combination of nickel and yttrium. This method yields high-purity ``mats'' of tangled nanotube bundlesThermal conductivity of single-walled carbon nanotubes J. Hone, M. Whitney, C. Piskoti, and A of single- walled carbon nanotubes from 350 K to 8 K. (T) decreases smoothly with decreasing temperature

  13. Thermal conductivity of the quark matter for the SU(2) light-flavor sector

    E-Print Network [OSTI]

    Seung-il Nam

    2015-03-04

    We investigate the thermal conductivity ($\\kappa$) of the quark matter at finite quark chemical potential $(\\mu)$ and temperature $(T)$, employing the Green-Kubo formula, for the SU(2) light-flavor sector with the finite current-quark mass $m=5$ MeV. As a theoretical framework, we construct an effective thermodynamic potential from the $(\\mu,T)$-modified liquid-instanton model (mLIM). Note that all the relevant model parameters are designated as functions of $T$, using the trivial-holonomy caloron solution. By solving the self-consistent equation of mLIM, we acquire the constituent-quark mass $M_0$ as a function of $T$ and $\\mu$, satisfying the universal-class patterns of the chiral phase transition. From the numerical results for $\\kappa$, we observe that there emerges a peak at $\\mu\\approx200$ MeV for the low-$T$ region, i.e. $T\\lesssim100$ MeV. As $T$ increase over $T\\approx100$ MeV, the curve for $\\kappa$ is almost saturated as a function of $T$ in the order of $\\sim10^{-1}\\,\\mathrm{GeV}^2$, and grows with respect to $\\mu$ smoothly. At the normal nuclear-matter density $\\rho_0=0.17\\,\\mathrm{fm}^{-3}$, $\\kappa$ shows its maximum $6.22\\,\\mathrm{GeV}^2$ at $T\\approx10$ MeV, then decreases exponentially down to $\\kappa\\approx0.2\\,\\mathrm{GeV}^2$. We also compute the ratio of $\\kappa$ and the entropy density, i.e. $\\kappa/s$ as a function of $(\\mu,T)$ which is a monotonically decreasing function for a wide range of $T$, then approaches a lower bound at very high $T$: $\\kappa/s_\\mathrm{min}\\gtrsim0.3\\,\\mathrm{GeV}^{-1}$ in the vicinity of $\\mu=0$.

  14. Method and apparatus for producing a carbon based foam article having a desired thermal-conductivity gradient

    DOE Patents [OSTI]

    Klett, James W. (Knoxville, TN) [Knoxville, TN; Cameron, Christopher Stan (Sanford, NC) [Sanford, NC

    2010-03-02

    A carbon based foam article is made by heating the surface of a carbon foam block to a temperature above its graphitizing temperature, which is the temperature sufficient to graphitize the carbon foam. In one embodiment, the surface is heated with infrared pulses until heat is transferred from the surface into the core of the foam article such that the graphitizing temperature penetrates into the core to a desired depth below the surface. The graphitizing temperature is maintained for a time sufficient to substantially entirely graphitize the portion of the foam article from the surface to the desired depth below the surface. Thus, the foam article is an integral monolithic material that has a desired conductivity gradient with a relatively high thermal conductivity in the portion of the core that was graphitized and a relatively low thermal conductivity in the remaining portion of the foam article.

  15. Thermal Conductivity Enhancement of High Temperature Phase Change Materials for Concentrating Solar Power Plant Applications

    E-Print Network [OSTI]

    Roshandell, Melina

    2013-01-01

    batteries. Solar Water Heater Solar water heater is becomingSolar Water Heater water heaters, thermal protection for electronics, spacecrafts, and solar

  16. Thermal Conductivity Enhancement of High Temperature Phase Change Materials for Concentrating Solar Power Plant Applications

    E-Print Network [OSTI]

    Roshandell, Melina

    2013-01-01

    batteries. Solar Water Heater Solar water heater is becomingSolar Water Heater heaters, thermal protection for electronics, spacecrafts, and solar

  17. Thermal Conductivity Enhancement of High Temperature Phase Change Materials for Concentrating Solar Power Plant Applications

    E-Print Network [OSTI]

    Roshandell, Melina

    2013-01-01

    for evening cooking in a solar cooker. Energy Convers ManageThermal performance of a solar cooker based on an evacuated

  18. Studies of non-diffusive heat conduction through spatially periodic and time-harmonic thermal excitations

    E-Print Network [OSTI]

    Collins, Kimberlee C. (Kimberlee Chiyoko)

    2015-01-01

    Studies of non-diffusive heat conduction provide insight into the fundamentals of heat transport in condensed matter. The mean free paths (MFPs) of phonons that are most important for conducting heat are well represented ...

  19. Microstructure changes and thermal conductivity reduction in UO2 following 3.9 MeV He2+ ion irradiation

    SciTech Connect (OSTI)

    Janne Pakrinen; Marat Khafizov; Lingfeng He; Chris Wetland; Jian Gan; Andrew T. Nelson; David H Hurley; Anter El-Azab; Todd R Allen

    2014-11-01

    The microstructural changes and associated effects on thermal conductivity were examined in UO2 after irradiation using 3.9 MeV He2+ ions. Lattice expansion of UO2 was observed in x-ray diffraction after ion irradiation up to 5×1016 He2+/cm2 at low-temperature (< 200 °C). Transmission electron microscopy (TEM) showed homogenous irradiation damage across an 8 µm thick plateau region, which consisted of small dislocation loops accompanied by dislocation segments. Dome-shaped blisters were observed at the peak damage region (depth around 8.5 µm) in the sample subjected to 5×1016 He2+/cm2, the highest fluence reached, while similar features were not detected at 9×1015 He2+/cm2. Laser-based thermo-reflectance measurements showed that the thermal conductivity for the irradiated layer decreased about 55 % for the high fluence sample and 35% for the low fluence sample as compared to an un-irradiated reference sample. Detailed analysis for the thermal conductivity indicated that the conductivity reduction was caused by the irradiation induced point defects.

  20. An exposure assessment survey of the Mont Belvieu polyethylene plant 

    E-Print Network [OSTI]

    Tucker, Thomas Franklin

    1997-01-01

    Evaluation of ever changing, complex workplaces can be accomplished with a sound, logical exposure assessment survey (EAS). An EAS was conducted at a polyethylene plant located in southeast Texas to determine the risk of adverse health effects...

  1. Effect of substrate on thermal conductivity of single-walled carbon nanotubes This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    methods confirmed that CNTs demonstrate anomalously high thermal conduc- tivity. However, recent of thermal energy along an isolated single-walled CNT and analyze the effect of a rigid substrateEffect of substrate on thermal conductivity of single-walled carbon nanotubes This article has been

  2. JOM, February 2013, Volume 65, Issue 2, pp 234-245 234 A Review of Thermal Conductivity of Polymer Matrix Syntactic Foams Effect of Hollow Particle Wall

    E-Print Network [OSTI]

    Gupta, Nikhil

    JOM, February 2013, Volume 65, Issue 2, pp 234-245 234 A Review of Thermal Conductivity of Polymer compositions of syntactic foams. Basic understating of the relationship between thermal conductivity Introduction Hollow particle filled polymer matrix composites, called syntactic foams, are used in weight

  3. Journal of Power Sources 161 (2006) 11061115 Direct measurement of through-plane thermal conductivity and

    E-Print Network [OSTI]

    Mench, Matthew M.

    2006-01-01

    and Diagnostics Laboratory, Department of Mechanical and Nuclear Engineering, The Pennsylvania State University® membrane; Diffusion media; Thermal contact resistance 1. Introduction Detailed knowledge of the internal management. In a fuel cell, local variation in temperature can be attributed to the waste heat generation

  4. ANALYTIC CRITERIA FOR THE MECHANICAL AND THERMAL STABILITY OF MAGNETIC STARS WITH FINITE ELECTRICAL CONDUCTIVITY

    E-Print Network [OSTI]

    pressure changes with the mass density as roughly 4/3 , and the Joule heating rate goes as roughly for dynamical, secular, and pulsational stability, but the Joule heating rate directly affects the secularANALYTIC CRITERIA FOR THE MECHANICAL AND THERMAL STABILITY OF MAGNETIC STARS WITH FINITE ELECTRICAL

  5. ASHRAE Transactions: Research 263 Determination of the ground's thermal conductivity is a

    E-Print Network [OSTI]

    is a significant challenge facing designers of ground-source heat pump (GSHP) systems applied in commercial buildings. The ground heat exchanger size and cost are highly dependent on the ground thermal properties parameters in ground heat exchanger design, and they are among the most difficult to quantify with sufficient

  6. Critical dynamics of thermal conductivity at the normal-superconducting transition Smitha Vishveshwara1

    E-Print Network [OSTI]

    Vishveshwara1 and Matthew P. A. Fisher2 1 Department of Physics, University of California, Santa Barbara, California 93106 2 Institute for Theoretical Physics, University of California, Santa Barbara, California expecta- tions. Recent attention has focused on thermal transport experiments,2 which have shed light

  7. CMDF Workshop, Caltech, 05.08.23 Applied Cluster Computing Technologies Group Modeling thermal conductivity

    E-Print Network [OSTI]

    Goddard III, William A.

    conductivity: a Green-Kubo approach Fabiano Oyafuso, Paul von Allmen, Markus Bühler Jet Propulsion Laboratory: Optimize ZT (efficiency) · engineering of phonon & electronic energy dispersions Focus of this work fitting (Genetic Algorithm) Boltzmann Transport Equation Green Kubo formalism Lattice contribution

  8. Temperature, thermal-conductivity, and heat-flux data,Raft River...

    Open Energy Info (EERE)

    conductivity; United States; USGS Authors Urban, T.C.; Diment, W.H.; Nathenson, M.; Smith, E.P.; Ziagos, J.P.; Shaeffer and M.H. Published Open-File Report - U. S. Geological...

  9. A new approach to low-conductivity, environmentally acceptable thermal insulation. Final report

    SciTech Connect (OSTI)

    Buckley, B.; Day, J.; Ferrero-Heredia, M.; Shanklin, E.; Varadarajan, G.; Woodruff, L.

    1996-02-01

    The object of this work was to develop a low-conductivity, economical, environmentally benign insulation. Specific objectives were to develop the following: (1) a very low conductivity use as ``super insulation`` in refrigerators, and (2) a general-purpose insulation for buildings and other applications. The technical goals of this work were to minimize gas phase, solid phase, and radiative conductivity. The novel approach pursued to achieve low gas phase conductivity was to blow foam with a removable gas or vapor, encapsulate the foam panel in a pouch made with a barrier film, and introduce a very low conductivity gas as the insulating gas phase. For super insulation and general-purpose insulation, the gases of choice were xenon and krypton, respectively. To control cost, the gases were present at low pressure, and the insulating panel was encapsulated with an impermeable polymeric film. Solid-phase conductivity was minimized by using low-density, open-cell, polyurethane foam. For super insulation, radiative heat transfer was impeded by placing aluminized Mylar films between relatively transparent 70-mil foam slabs. For general-purpose insulation, it was projected to impede radiative heat transfer by achieving the same very small cell size with open-cell CO{sub 2}-blown foam as is now achieved with closed-cell CO{sub 2}-blown foam.

  10. Reduction of thermal conductivity of anharmonic lattices Lei Wang1 and Baowen Li1,2,3,

    E-Print Network [OSTI]

    Li, Baowen

    /or heat "modulator." The physical mechanism for thermal diode and thermal transistor may be extended

  11. A high thermal conductivity waveguide window for use in a free electron laser

    SciTech Connect (OSTI)

    T. Elliott; V. Nguyen; L. Phillips; J. Preble (Jefferson Lab); T. Schultheiss; V. Christina; M. Cole; J. Rathke (Northrop Grumman Corp.)

    1999-04-01

    Design, analysis, and testing of a waveguide window with a goal of propagating greater than 100 kW average power operating at 1500 Mhz has been performed. This is made possible by the favorable material properties of beryllia (BeO). Brazing the window to a soft copper frame and then brazing the frame to a KOVAR flange provides the vacuum seal. RF analysis combined with thermal/structural analysis shows the benefits of the material. The KOVAR flange with a CTE, coefficient of thermal expansion, that matches that of BeO enables a strong braze joint. RF testing to 35 kW has been successful. The basics of this design can be expanded to applications with lower frequencies and higher average power. A paper similar to this was presented at LINAC 98.

  12. Measuring the thermal boundary conductance between graphite and thin film by time-domain thermoreflectance

    E-Print Network [OSTI]

    Maruyama, Shigeo

    Variable Delay CCD Detector Aperture /2 plate Optical Isolator Electro-Optic Modulator Pump Beam Probe Beam in this study: (a) sectional view; and (b) TBC model. Probe HOPG Al thin film Pump z dHOPG dAlkAl kHOPG DAl()sinh( )sinh( 1 )cosh( f M f qdqdkq qd kq qd f (2) Volumetric heat capacity [106 Jm-3 K-1 ] Thermal

  13. Simulated evolution of fractures and fracture networks subject to thermal cooling: A coupled discrete element and heat conduction model

    SciTech Connect (OSTI)

    Huang, Hai; Plummer, Mitchell; Podgorney, Robert

    2013-02-01

    Advancement of EGS requires improved prediction of fracture development and growth during reservoir stimulation and long-term operation. This, in turn, requires better understanding of the dynamics of the strongly coupled thermo-hydro-mechanical (THM) processes within fractured rocks. We have developed a physically based rock deformation and fracture propagation simulator by using a quasi-static discrete element model (DEM) to model mechanical rock deformation and fracture propagation induced by thermal stress and fluid pressure changes. We also developed a network model to simulate fluid flow and heat transport in both fractures and porous rock. In this paper, we describe results of simulations in which the DEM model and network flow & heat transport model are coupled together to provide realistic simulation of the changes of apertures and permeability of fractures and fracture networks induced by thermal cooling and fluid pressure changes within fractures. Various processes, such as Stokes flow in low velocity pores, convection-dominated heat transport in fractures, heat exchange between fluid-filled fractures and solid rock, heat conduction through low-permeability matrices and associated mechanical deformations are all incorporated into the coupled model. The effects of confining stresses, developing thermal stress and injection pressure on the permeability evolution of fracture and fracture networks are systematically investigated. Results are summarized in terms of implications for the development and evolution of fracture distribution during hydrofracturing and thermal stimulation for EGS.

  14. Thermal conductance of the junction between single-walled carbon nanotubes

    E-Print Network [OSTI]

    McGaughey, Alan

    conductances of the carbon nanotube (CNT) junctions that would be found in a CNT aerogel are predicted using of carbon nanotubes (CNTs) (e.g., aligned films, mats, and aerogels) are candidates for use in electronic issue in all of these applications. Our focus here is related to single-walled CNT aerogels, which

  15. The thermally stimulated conductivity in amorphous thin film As?Se? 

    E-Print Network [OSTI]

    Bryant, John Duffie

    1972-01-01

    V with a 14 -3 density of 9. 73 x 10 cm . The thermal velocity of the carriers 6 -18 was 6. 34 x 10 cm/sec, and the capture cross section was 2. 7 x 10 2 cm . These results indicate that the Nett-Davis model is more ap- plicable to amorphous As Se... II-3 Sample Holder Design (not to scale) 15 16 17 11-4 Output Curve for Chromel-Constantan Thermo- couple (Voltage vs. Temperature) (ref. 29) 19 II-5 System Cooling Curve (Temperature vs. Time) 20 II-6 System Heating Curve for a Constant Heater...

  16. Morphology of PolyethyleneCarbon Black Composites G. BEAUCAGE,1

    E-Print Network [OSTI]

    Beaucage, Gregory

    -ray scattering (SAXS) study of a conductive grade of carbon black and carbon black­polymer composites and a power-law scaling of polydispersity. One use of conductive black­polyethylene composites is in circuit(methyl methacrylate); carbon black; filler; composite; conductivity; percolation INTRODUCTION The morphology

  17. Method for the thermal characterization, visualization, and integrity evaluation of conducting material samples or complex structures

    DOE Patents [OSTI]

    Ortiz, Marcos G. (Idaho Falls, ID)

    1992-01-01

    A method for modeling a conducting material sample or structure (herein called a system) as at least two regions which comprise an electrical network of resistances, for measuring electric resistance between at least two selected pairs of external leads attached to the surface of the system, wherein at least one external lead is attached to the surface of each of the regions, and, using basic circuit theory, for translating measured resistances into temperatures or thermophysical properties in corresponding regions of the system.

  18. Thermal conductivity and contact resistance of metal foams This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Bahrami, Majid

    distribution in metal foams is necessary for design and modelling of thermal-hydraulic systems incorporating conductivity and TCR in metal foams is described. Measurements are performed in a vacuum under varying

  19. 332 Journal of The Anterican Ceranaic Society -Aksay et al. Vol. 62, NO.7-8 "H.Marchandise. "Thermal Conductivity of Uranium Dioxide." Commission of

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    . E. Youngblwd. "Thermal DiffusivityiConductivity of Alumina with a Zirconia Dispersed Phase." Am, Lawrence Berkeley Laboratory and Department of Materials Science and Mineral Engineering, College of Engineering, University of California, Berkeley, California 94720 ROBERT F. DAVIS*$' Department of Materials

  20. Thermal dilepton rate and electrical conductivity: An analysis of vector current correlation functions in quenched lattice QCD

    E-Print Network [OSTI]

    H. -T. Ding; A. Francis; O. Kaczmarek; F. Karsch; E. Laermann; W. Soeldner

    2011-02-04

    We calculate the vector current correlation function for light valence quarks in the deconfined phase of QCD. The calculations have been performed in quenched lattice QCD at T=1.45 Tc for four values of the lattice cut-off on lattices up to size 128^3x48. This allows to perform a continuum extrapolation of the correlation function in the Euclidean time interval tau*T -in [0.2, 0.5], which extends to the largest temporal separations possible at finite temperature, to better than 1% accuracy. In this interval, at the value of the temperature investigated, we find that the vector correlation function never deviates from the free correlator for massless quarks by more than 9%. We also determine the first two non-vanishing thermal moments of the vector meson spectral function. The second thermal moment deviates by less than 7% from the free value. With these constraints, we then proceed to extract information on the spectral representation of the vector correlator and discuss resulting consequences for the electrical conductivity and the thermal dilepton rate in the plasma phase.

  1. Fully-coupled engineering and mesoscale simulations of thermal conductivity in UO2 fuel using an implicit multiscale approach

    SciTech Connect (OSTI)

    Michael Tonks; Derek Gaston; Cody Permann; Paul Millett; Glen Hansen; Chris Newman

    2009-08-01

    Reactor fuel performance is sensitive to microstructure changes during irradiation (such as fission gas and pore formation). This study proposes an approach to capture microstructural changes in the fuel by a two-way coupling of a mesoscale phase field irradiation model to an engineering scale, finite element calculation. This work solves the multiphysics equation system at the engineering-scale in a parallel, fully-coupled, fully-implicit manner using a preconditioned Jacobian-free Newton Krylov method (JFNK). A sampling of the temperature at the Gauss points of the coarse scale is passed to a parallel sequence of mesoscale calculations within the JFNK function evaluation phase of the calculation. The mesoscale thermal conductivity is calculated in parallel, and the result is passed back to the engineering-scale calculation. As this algorithm is fully contained within the JFNK function evaluation, the mesoscale calculation is nonlinearly consistent with the engineering-scale calculation. Further, the action of the Jacobian is also consistent, so the composite algorithm provides the strong nonlinear convergence properties of Newton's method. The coupled model using INL's \\bison\\ code demonstrates quadratic nonlinear convergence and good parallel scalability. Initial results predict the formation of large pores in the hotter center of the pellet, but few pores on the outer circumference. Thus, the thermal conductivity is is reduced in the center of the pellet, leading to a higher internal temperature than that in an unirradiated pellet.

  2. Impact of Temperature-dependent resistivity and thermal conduction on plasmoid Instabilities in current sheets in the solar corona

    E-Print Network [OSTI]

    Ni, Lei; Lin, Jun; Ziegler, Udo

    2013-01-01

    In this paper we investigate, by means of two-dimensional magnetohydrodynamic simulations, the impact of temperature-dependent resistivity and thermal conduction on the development of plasmoid instabilities in reconnecting current sheets in the solar corona. We find that the plasma temperature in the current sheet region increases with time and it becomes greater than that in the inflow region. As secondary magnetic islands appear, the highest temperature is not always found at the reconnection $X$-points, but also inside the secondary islands. One of the effects of anisotropic thermal conduction is to decrease the temperature of the reconnecting $X-$points and transfer the heat into the $O-$points, the plasmoids, where it gets trapped. In the cases with temperature-dependent magnetic diffusivity, $\\eta \\sim T^{-3/2}$, the decrease in plasma temperature at the $X-$points leads to: (i) increase in the magnetic diffusivity until the characteristic time for magnetic diffusion becomes comparable to that of therma...

  3. Method for the thermal characterization, visualization, and integrity evaluation of conducting material samples or complex structures

    DOE Patents [OSTI]

    Ortiz, M.G.

    1992-11-24

    Disclosed is a method for modeling a conducting material sample or structure (herein called a system) as at least two regions which comprise an electrical network of resistances, for measuring electric resistance between at least two selected pairs of external leads attached to the surface of the system, wherein at least one external lead is attached to the surface of each of the regions, and, using basic circuit theory, for translating measured resistances into temperatures or thermophysical properties in corresponding regions of the system. 16 figs.

  4. Thermal interaction between free convection and forced convection along a vertical conducting wall

    E-Print Network [OSTI]

    Shu, Jian-Jun

    2015-01-01

    A theoretical study is presented in this paper to investigate the conjugate heat transfer across a vertical finite wall separating two forced and free convection flows at different temperatures. The heat conduction in the wall is in the transversal direction and countercurrent boundary layers are formed on the both sides of the wall. The governing equations of this problem and their corresponding boundary conditions are all cast into a dimensionless form by using a non-similarity transformation. These resultant equations with multiple singular points are solved numerically using a very efficient singular perturbation method. The effects of the resistance parameters and Prandtl numbers on heat transfer characteristics are investigated.

  5. Suppression of thermal conductivity in graphene nanoribbons with rough edges Alexander V. Savin,1,2 Yuri S. Kivshar,2 and Bambi Hu3,4

    E-Print Network [OSTI]

    , Moscow 119991, Russia 2Nonlinear Physics Center, Research School of Physics and Engineering, Australian, the thermal properties of graphene are also of both fundamental and practical im- portance. SeveralSuppression of thermal conductivity in graphene nanoribbons with rough edges Alexander V. Savin,1

  6. Thermal Conductivity Measurement of Xe-Implanted Uranium Dioxide Thick Films using Multilayer Laser Flash Analysis

    SciTech Connect (OSTI)

    Nelson, Andrew T. [Los Alamos National Laboratory

    2012-08-30

    The Fuel Cycle Research and Development program's Advanced Fuels campaign is currently pursuing use of ion beam assisted deposition to produce uranium dioxide thick films containing xenon in various morphologies. To date, this technique has provided materials of interest for validation of predictive fuel performance codes and to provide insight into the behavior of xenon and other fission gasses under extreme conditions. In addition to the structural data provided by such thick films, it may be possible to couple these materials with multilayer laser flash analysis in order to measure the impact of xenon on thermal transport in uranium dioxide. A number of substrate materials (single crystal silicon carbide, molybdenum, and quartz) containing uranium dioxide films ranging from one to eight microns in thickness were evaluated using multilayer laser flash analysis in order to provide recommendations on the most promising substrates and geometries for further investigation. In general, the uranium dioxide films grown to date using ion beam assisted deposition were all found too thin for accurate measurement. Of the substrates tested, molybdenum performed the best and looks to be the best candidate for further development. Results obtained within this study suggest that the technique does possess the necessary resolution for measurement of uranium dioxide thick films, provided the films are grown in excess of fifty microns. This requirement is congruent with the material needs when viewed from a fundamental standpoint, as this length scale of material is required to adequately sample grain boundaries and possible second phases present in ceramic nuclear fuel.

  7. ANISOTROPIC THERMAL CONDUCTIVITY IN A DIRTY TYPE II SUPERCONDUCTOR J.P.M. Van der Veeken, P.H. Kes and D. de Klerk

    E-Print Network [OSTI]

    Boyer, Edmond

    ANISOTROPIC THERMAL CONDUCTIVITY IN A DIRTY TYPE II SUPERCONDUCTOR J.P.M. Van der Veeken, P.H. Kes, The results are compared with calculations by Watts - Tobin and Imai. For dirty type II superconductors) of the total conductivities. ii) The theoretical calculations are valid only for BCS - superconductors

  8. Photoelectrochemical investigation of a poly(ethylene oxide) cell

    SciTech Connect (OSTI)

    Sammells, A.F.; Ang, G.P.

    1984-03-01

    The photoelectrochemical properties of cells based on the solid polymer electrolyte (SPE) poly(ethylene oxide)/NaSCN with Na2S/S as a redox species are investigated experimentally. The preparation of the SPE is described in detail. Current/voltage curves or voltage/time are shown for cells using p-InP/SPE/conducting-glass, n-GaAs/SPE/conducting-glass, and p-InP/SPE/n-CdS structures. It is concluded that practical cells based on SPE of this type will require increases in the ionic conductivity of poly(ethylene oxide). 13 references.

  9. Topological Twistons in Crystalline Polyethylene

    E-Print Network [OSTI]

    D. Bazeia; E. Ventura

    1999-02-09

    We introduce an alternate model to describe twistons in crystalline polyethylene. The model couples torsional and longitudinal degrees of freedom and appears as an extension of a model that describes only the torsional motion. We find exact solutions that describe stable topological twistons, in good agreement with the torsional and longitudinal interactions in polyethylene.

  10. Nonlinear Electron Heat Conduction Equation and Self similar method for 1-D Thermal Waves in Laser Heating of Solid Density DT Fuel

    E-Print Network [OSTI]

    A. Mohammadian Pourtalari; M. A. Jafarizadeh; M. Ghoranneviss

    2011-11-23

    Electron heat conduction is one of the ways that energy transports in laser heating of fusible target material. The aim of Inertial Confinement Fusion (ICF) is to show that the thermal conductivity is strongly dependent on temperature and the equation of electron heat conduction is a nonlinear equation. In this article, we solve the one-dimensional (1-D) nonlinear electron heat conduction equation with a self-similar method (SSM). This solution has been used to investigate the propagation of 1-D thermal wave from a deuterium-tritium (DT) plane source which occurs when a giant laser pulse impinges onto a DT solid target. It corresponds to the physical problem of rapid heating of a boundary layer of material in which the energy of laser pulse is released in a finite initial thickness.

  11. Thermal and Electrical Transport in Oxide Heterostructures

    E-Print Network [OSTI]

    Ravichandran, Jayakanth

    2011-01-01

    of thermal conductivity . . . . . . . . . . . . . . . .4.4 Thermal transport in2.3.2 Thermal transport . . . . . . . . . . . . . . . .

  12. Temperature dependence of thermal conductivity of AlxGa1-xN thin films measured by the differential 3 technique

    E-Print Network [OSTI]

    Engineering, University of California­Riverside, Riverside, California 92521 (Received 2 July 2004; accepted conductivity of AlxGa1-xN thin films (x=0 and 0.4) grown by the hydride vapor phase epitaxy. ThermalN thin films (x=0 and 0.4) grown by the hydride vapor phase epitaxy (HVPE). The accurate values

  13. Heat Transfer -1 You are given the following information for a fluid with thermal conductivity of k = 0.0284 W/m-K that

    E-Print Network [OSTI]

    Virginia Tech

    Heat Transfer - 1 You are given the following information for a fluid with thermal conductivity the flow is laminar near the wall. a) (30 points) Determine the corresponding heat transfer coefficient the heat transfer coefficient as a function of x. c) (25 points) Determine the average heat transfer

  14. Thermal conductivity of MgO, MgSiO3 perovskite and post-perovskite in the Earth's deep mantle

    E-Print Network [OSTI]

    Haigis, Volker; Jahn, Sandro; 10.1016/j.epsl.2012.09.002

    2012-01-01

    We report lattice thermal conductivities of MgO and MgSiO3 in the perovskite and post-perovskite structures at conditions of the Earth's lower mantle, obtained from equilibrium molecular dynamics simulations. Using an advanced ionic interaction potential, the full conductivity tensor was calculated by means of the Green-Kubo method, and the conductivity of MgSiO3 post-perovskite was found to be significantly anisotropic. The thermal conductivities of all three phases were parameterized as a function of density and temperature. Assuming a Fe-free lower-mantle composition with mole fractions xMgSiO3 = 0.66 and xMgO = 0.34, the conductivity of the two-phase aggregate was calculated along a model geotherm. It was found to vary considerably with depth, rising from 9.5 W/(mK) at the top of the lower mantle to 20.5 W/(mK) at the top of the thermal boundary layer above the core-mantle boundary. Extrapolation of experimental data suggests that at deep-mantle conditions, the presence of a realistic amount of iron impur...

  15. Development of an Innovative High-Thermal Conductivity UO2 Ceramic Composites Fuel Pellets with Carbon Nano-Tubes Using Spark Plasma Sintering

    SciTech Connect (OSTI)

    Subhash, Ghatu; Wu, Kuang-Hsi; Tulenko, James

    2014-03-10

    Uranium dioxide (UO2) is the most common fuel material in commercial nuclear power reactors. Despite its numerous advantages such as high melting point, good high-temperature stability, good chemical compatibility with cladding and coolant, and resistance to radiation, it suffers from low thermal conductivity that can result in large temperature gradients within the UO2 fuel pellet, causing it to crack and release fission gases. Thermal swelling of the pellets also limits the lifetime of UO2 fuel in the reactor. To mitigate these problems, we propose to develop novel UO2 fuel with uniformly distributed carbon nanotubes (CNTs) that can provide high-conductivity thermal pathways and can eliminate fuel cracking and fission gas release due to high temperatures. CNTs have been investigated extensively for the past decade to explore their unique physical properties and many potential applications. CNTs have high thermal conductivity (6600 W/mK for an individual single- walled CNT and >3000 W/mK for an individual multi-walled CNT) and high temperature stability up to 2800°C in vacuum and about 750°C in air. These properties make them attractive candidates in preparing nano-composites with new functional properties. The objective of the proposed research is to develop high thermal conductivity of UO2–CNT composites without affecting the neutronic property of UO2 significantly. The concept of this goal is to utilize a rapid sintering method (5–15 min) called spark plasma sintering (SPS) in which a mixture of CNTs and UO2 powder are used to make composites with different volume fractions of CNTs. Incorporation of these nanoscale materials plays a fundamentally critical role in controlling the performance and stability of UO2 fuel. We will use a novel in situ growth process to grow CNTs on UO2 particles for rapid sintering and develop UO2-CNT composites. This method is expected to provide a uniform distribution of CNTs at various volume fractions so that a high thermally conductive UO2-CNT composite is obtained with a minimal volume fraction of CNTs. The mixtures are sintered in the SPS facility at a range of temperatures, pressures, and time durations so as to identify the optimal processing conditions to obtain the desired microstructure of sintered UO2-CNT pellets. The second objective of the proposed work is to identify the optimal volume fraction of CNTs in the microstructure of the composites that provides the desired high thermal conductivity yet retaining the mechanical strength required for efficient function as a reactor fuel. We will systematically study the resulting microstructure (grain size, porosity, distribution of CNTs, etc.) obtained at various SPS processing conditions using optical microscopy, scanning electron microscopy (SEM), and transmission electron microscope (TEM). We will conduct indentation hardness measurements and uniaxial strength measurements as a function of volume fraction of CNTs to determine the mechanical strength and compare them to the properties of UO2. The fracture surfaces will be studied to determine the fracture characteristics that may relate to the observed cracking during service. Finally, we will perform thermal conductivity measurements on all the composites up to 1000° C. This study will relate the microstructure, mechanical properties, and thermal properties at various volume fractions of CNTs. The overall intent is to identify optimal processing conditions that will provide a well-consolidated compact with optimal microstructure and thermo-mechanical properties. The deliverables include: (1) fully characterized UO2-CNT composite with optimal CNT volume fraction and high thermal conductivity and (2) processing conditions for production of UO2-CNT composite pellets using SPS method.

  16. Phase Structure and Properties of Poly(ethylene terephthalate)/High-Density Polyethylene Based on

    E-Print Network [OSTI]

    University of Science and Technology, Shanghai 200237, People's Republic of China Received 12 June 2008 words: polyethylene; recycling; blends; poly(ethylene terephthalate) INTRODUCTION Plastics account-density polyethylene (LDPE), polypropylene (PP), Poly (ethylene terephthalate) (PET), etc. The plastic waste

  17. Evaluation of the Thermal Performance for a Wire Mesh/Hollow Glass Microsphere Composite Structure as a Conduction Barrier 

    E-Print Network [OSTI]

    Mckenna, Sean

    2010-01-15

    ]. For instance, application of microsphere insulated pressure vessels for hydrogen storage on vehicles showed good thermal performance [15]. In addition, Mueller [16] in examining cryogenic liquefaction and storage, considered critical in a potential human...

  18. Abnormal thermal conductivity in tetragonal tungsten bronze Ba{sub 6?x}Sr{sub x}Nb{sub 10}O{sub 30}

    SciTech Connect (OSTI)

    Kolodiazhnyi, T. Sakurai, H.; Vasylkiv, O.; Borodianska, H.; Mozharivskyj, Y.

    2014-03-17

    Ba{sub 6?x}Sr{sub x}Nb{sub 10}O{sub 30} solid solution with 0???x???6 crystallizes in centrosymmetric tetragonal “tungsten bronze” structure (space group P4/mbm). We report on the x dependence of thermal conductivity of polycrystalline samples measured in the 2–400?K temperature interval. Substitution of Sr for Ba brings about a significant decrease in thermal conductivity at x???3 accompanied by development of a low-temperature (T???10–30?K) “plateau” region reminiscent of a glass-like compounds. We explain this behaviour based on a size-driven site occupancy and atomic displacement parameters associated with an alkaline earth atomic positions in the title compounds.

  19. Microwavable thermal energy storage material

    DOE Patents [OSTI]

    Salyer, I.O.

    1998-09-08

    A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments. 3 figs.

  20. Microwavable thermal energy storage material

    DOE Patents [OSTI]

    Salyer, Ival O. (Dayton, OH)

    1998-09-08

    A microwavable thermal energy storage material is provided which includes a mixture of a phase change material and silica, and a carbon black additive in the form of a conformable dry powder of phase change material/silica/carbon black, or solid pellets, films, fibers, moldings or strands of phase change material/high density polyethylene/ethylene-vinyl acetate/silica/carbon black which allows the phase change material to be rapidly heated in a microwave oven. The carbon black additive, which is preferably an electrically conductive carbon black, may be added in low concentrations of from 0.5 to 15% by weight, and may be used to tailor the heating times of the phase change material as desired. The microwavable thermal energy storage material can be used in food serving applications such as tableware items or pizza warmers, and in medical wraps and garments.

  1. Photon tunnelling microscopy of polyethylene single crystals

    E-Print Network [OSTI]

    Srinivasarao, Mohan

    Photon tunnelling microscopy of polyethylene single crystals Mohan Srinivasarao* and Richard S:photon tunnellingmicroscopy;single crystals; polyethylene) INTRODUCTION The study of morphology of polymers is an area

  2. Annealing of single lamella nanoparticles of polyethylene

    E-Print Network [OSTI]

    Christophe N. Rochette; Sabine Rosenfeldt; Katja Henzler; Frank Polzer; Matthias Ballauff; Qiong Tong; Stefan Mecking; Markus Drechsler; Theyencheri Narayanan; Ludger Harnau

    2011-07-05

    We study the change of the size and structure of freely suspended single lamella nanoparticles of polyethylene during thermal annealing in aqueous solutions. Using small-angle x-ray scattering and cryogenic transmission electron microscopy, it is shown that a doubling of the crystalline lamella sandwiched between two amorphous polymer layers is obtained by annealing the nanoparticles at 125 C. This thickening of the crystalline lamella can be understood in terms of an unlooping of polymer chains within a single nanoparticle. In addition a variation of the annealing temperature from 90 C to 115 C demonstrates that the inverse of the crystalline lamellar thickness increases linearly with the annealing temperatures leading to a recrystallization line in a Gibbs-Thomson graph. Since the nanoparticles consist of about only eight polymer chains, they can be considered as a ideal candidates for the experimental realization of equilibrium polymer crystals.

  3. Profiles in garbage: Polyethylene terephthalate

    SciTech Connect (OSTI)

    Miller, C. [Environmental Industry Associations, Washington, DC (United States)

    1997-11-01

    Polyethylene terephthalate (PET) is a plastic resin used primarily to make bottles. Soft drinks -- along with salad dressing, fruit juices, peanut butter, and other household and consumer products -- use PET bottles. PET also is used for film, sheeting for cups and food trays, oven-safe trays, and other uses. PET is a relatively new packaging resin, first commercialized in the early 1970s. Because it is an ``engineered`` resin, PET is more expensive than commodity resins such as high-density polyethylene (HDPE) and, for the same reason, it is usually the highest valued plastic recyclable.

  4. Nanoscale Calorimetry of Isolated Polyethylene Single Crystals

    E-Print Network [OSTI]

    Allen, Leslie H.

    Nanoscale Calorimetry of Isolated Polyethylene Single Crystals A. T. KWAN, M. YU. EFREMOV, E. A-film differential scanning calorimetry to investigate the melt- ing of isolated polyethylene single crystals of lamellar single crystals of polyethylene (PE). We obtain thickness, diffraction, and calorimetry data

  5. Phonon-hopping thermal conduction in quantum dot superlattices Manu Shamsa, Weili Liu, and Alexander A. Balandina

    E-Print Network [OSTI]

    of California--Riverside, Riverside, California 92521 Jianlin Liu Quantum Structures Laboratory, Department of Electrical Engineering, University of California--Riverside, Riverside, California 92521 Received 18 April or polycrystalline materials in terms of thermal transport. © 2005 American Institute of Physics. DOI: 10

  6. Thermal Management of Solar Cells

    E-Print Network [OSTI]

    Saadah, Mohammed Ahmed

    2013-01-01

    phonon transmission and interface thermal conductance acrossF. Miao, et al. , "Superior Thermal Conductivity of Single-Advanced Materials for Thermal Management of Electronic

  7. Design, analysis, and testing of a high thermal conductivity waveguide window for use in a free-electron laser

    SciTech Connect (OSTI)

    T. Schultheiss; V. Christina; M. Cole; J. Rathke; T. Elliott; V. Nguyen; L. Phillips; J. Preble

    1998-08-01

    Design, analysis and testing of a waveguide window with a goal of propagating greater than 100 kW average power operating at 1500 Mhz has been performed. This is made possible by the favorable material properties of Beryllia (BeO). Brazing the window to a soft copper frame and then brazing the frame to a KOVAR flange provides the vacuum seal. RF analysis combined with thermal/structural analysis shows the benefits of the material. The KOVAR flange with a CTE,coefficient of thermal expansion, that matches that of BeO enables a strong braze joint. RF testing to 35 kW has been successful, and higher powers will be tested in the near future. The basics of this design can be expanded to applications with lower frequencies and higher average power.

  8. Pressure dependence of harmonic and an harmonic lattice dynamics in MgO: A ?rst-principles calculation and implications for lattice thermal conductivity

    SciTech Connect (OSTI)

    Tang, Xiaoli [Physics Department, Auburn University, Auburn, Alabama (United States); Dong, Jianjun [Physics Department, Auburn University, Auburn, Alabama (United States)

    2009-05-01

    We report a recent first-principles calculation of harmonic and anharmonic lattice dynamics of MgO. The 2nd order harmonic and 3rd order anharmonic interatomic interaction terms are computed explicitly, and their pressure dependences are discussed. The phonon mode Grueneisen parameters derived based on our calculated 3rd order lattice anharmonicity are in good agreement with those estimated using the finite difference method. The implications for lattice thermal conductivity at high pressure are discussed based on a simple kinetic transport theory.

  9. Waste product profile: Polyethylene terephthalate

    SciTech Connect (OSTI)

    Miller, C. [Environmental Industry Associations, Washington, DC (United States)

    1996-02-01

    Polyethylene terephthalate (PET) is a plastic resin used primarily to make bottles. Soft drinks are the primary product packaged in PET. Salad dressing, peanut butter, and other household and consumer products also use PET bottles. PET is also used for film, sheeting for cups and food trays, ovenable trays, and other uses. PET is a relatively new packaging resin, first commercialized in the early `70s. Because it is an ``engineered`` resin, it is more expensive than commodity resins such as high-density polyethylene (HDPE). The primary market for recycled PET is the fiber industry, which uses PET for carpet fiber, sweaters and other clothing, and for other uses. Recycled PET can also be used for food and beverage containers. Export markets, particularly Asian countries, are becoming increasingly important.

  10. Transient current generation during wear of high-density polyethylene by a stainless-steel stylus

    E-Print Network [OSTI]

    Dickinson, J. Thomas

    by conducting styli of single-crystal inorganics including MgO and NaCl ,9 polymers including poly methylmethacrylate , polycarbonate, polystyrene, and polyethylene ,7 and metal surfaces in the presence when contact with other insulating or conducting surfaces is broken. This work describes the use

  11. Microstructural Evolution of 7 wt.% Y2O3 ZrO2 Thermal Barrier Coatings due to Stress Relaxation at Elevated Temperatures and the Concomitant changes in Thermal Conductivity

    SciTech Connect (OSTI)

    Petorak, Christopher [Purdue University; Ilavsky, Dr. Jan [Argonne National Laboratory (ANL); Wang, Hsin [ORNL; Porter, Wallace D [ORNL; Trice, Rodney [Purdue University

    2010-01-01

    The purpose of this study was to evaluate the combined effect of stress and temperature on the microstructure of air plasma-sprayed 7 wt.% Y{sub 2}O{sub 3}-ZrO{sub 2} thermal barrier coatings, and relate microstructural changes to the thermal conductivity, k{sub th}. To simulate TBC service conditions, stand-alone tubes of YSZ were stress relaxed, starting from a compressive stress of 60 MPa, at temperatures of 1000 C or 1200 C. The duration of the stress relaxation test was either 5 min or 3 h. Detailed scanning electron microscopy (SEM) and Porod's specific surface area (SSA) analysis of small angle neutron scattering (SANS) results were used to determine which void systems, either interlamellar pores or intralamellar cracks, contributed to the observed relaxation of stress in the coatings. SEM investigations revealed closure of intralamellar cracks located perpendicular to the stress direction. For thinner YSZ coatings, SANS measurements indicated a statistically significant reduction in the total SSA and SSA associated with intralamellar cracks after stress relaxation at the times, temperatures, and stress investigated compared to those samples that were exposed to identical times and temperatures, but no stress. The SSA associated with the interlamellar pores was not significantly smaller in YSZ coatings stress relaxed from 60 MPa at 1200 C for 3 h compared to as-sprayed coatings. The thermal conductivity of the coatings was strongly influenced by stress, with increases in kth observed after only 5 min at 60 MPa and 1200 C. Reductions in the total SSA were directly linked to increases in k{sub th}.

  12. Branch content of metallocene polyethylene Ramnath Ramachandran, Gregory Beaucage*

    E-Print Network [OSTI]

    Beaucage, Gregory

    Branch content of metallocene polyethylene Ramnath Ramachandran, Gregory Beaucage* and Amit catalyzed polyethylene (PE). A novel scaling approach is applied to determine the mole fraction branch solutions of metallocene polyethylene samples, to quantify the LCB content in polymers previously studied

  13. Poly(ethylene oxide) functionalization

    DOE Patents [OSTI]

    Pratt, Russell Clayton

    2014-04-08

    A simple procedure is provided by which the hydroxyl termini of poly(ethylene oxide) can be appended with functional groups to a useful extent by reaction and precipitation. The polymer is dissolved in warmed toluene, treated with an excess of organic base and somewhat less of an excess of a reactive acylating reagent, reacted for several hours, then precipitated in isopropanol so that the product can be isolated as a solid, and salt byproducts are washed away. This procedure enables functionalization of the polymer while not requiring laborious purification steps such as solvent-solvent extraction or dialysis to remove undesirable side products.

  14. Effect of optically modified polyethylene terephthalate fiber socks on chronic foot pain

    E-Print Network [OSTI]

    York, Robyn MB; Gordon, Ian L

    2009-01-01

    of optically modified polyethylene terephthalate fiber sockswhether socks made from polyethylene terephthalate (PET)

  15. Thermal Transport in Graphene Multilayers and Nanoribbons

    E-Print Network [OSTI]

    Subrina, Samia

    2011-01-01

    1 CHAPTER 2 Thermal transport atvalues of graphene’s thermal conductivity and different1 Thermal conductivity : metals and non - metallic

  16. Branch length distribution in TREF fractionated polyethylene Ramnath Ramachandran a

    E-Print Network [OSTI]

    Beaucage, Gregory

    Branch length distribution in TREF fractionated polyethylene Ramnath Ramachandran a , Gregory Keywords: Polyethylene Branching Neutron scattering a b s t r a c t Commercial polyethylene is typically and catalyst activity. Further, processing of polyethylene after polymerization may also result in changes

  17. An atomistic description of the high-field degradation of dielectric polyethylene

    SciTech Connect (OSTI)

    Bealing, Clive R.; Ramprasad, R.

    2013-11-07

    A microscopic mechanism governing the initiating step in the high-field aging of crystalline polyethylene is proposed, based on density functional calculations and ab initio molecular dynamics simulations. It is assumed that electrons, holes, and excitons are present in the system. While the additional individual electrons or holes are not expected to lead to significant degradation, the presence of triplet excitons are concluded to be rather damaging. The electron and hole states of the exciton localize on a distorted region of polyethylene, significantly weakening nearby C–H bonds and facilitating C–H bond scission. The barrier to cleavage of the weakened C–H bonds is estimated and is comparable to the thermal energy, suggesting that this mechanism may be responsible for the degradation of polyethylene when placed under electrical stress, e.g., in high-voltage cables.

  18. Accelerated screening methods for determining chemical and thermal stability of refrigerant-lubricant mixtures, Part II: Experimental comparison and verification of methods. Volume 2, In situ conductivity data

    SciTech Connect (OSTI)

    Kauffman, R.

    1995-09-01

    Data are presented for the accelerated screening methods for determining chemical and thermal stability of refrigerant-lubricant mixtures.

  19. Polyethylene as a Radiation Shielding Standard in Simulated Cosmic-Ray Environments

    E-Print Network [OSTI]

    2006-01-01

    on the ISS through polyethylene shielding augmentation ofnucleon Iron-56 in Polyethylene. II. , Comparisons betweenPolyethylene as a Radiation Shielding Standard in Simulated

  20. A strategy for the quantification of protein polyethylene glycol (PEG) derivatized sites using iTRAQ

    E-Print Network [OSTI]

    Monk, Rebecca Helen

    2011-01-01

    for characterization of polyethylene glycol-derivatizedof the attachment sites in polyethylene glycol-derivatizedfor the Quantification of Protein Polyethylene Glycol (PEG)

  1. Polyethylene as a Radiation Shielding Standard in Simulated Cosmic-Ray Environments

    E-Print Network [OSTI]

    2006-01-01

    on the ISS through polyethylene shielding augmentation offrom traversal of polyethylene shielding. We define theof the shielding properties of polyethylene and other

  2. Besides these questions regarding the efficiency of condensation or thermal conduction in the inner flow, we note that there are other important questions regarding EC theory and implementation, including

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Besides these questions regarding the efficiency of condensation or thermal conduction in the inner with jumps in the power-law component, yet the recovery phase and recurrence of such disk- rate drops occur,10] is bounded, but set manually in code CHW Compton-heated winds based on reliable prescription [11

  3. Polymeric compositions incorporating polyethylene glycol as a phase change material

    DOE Patents [OSTI]

    Salyer, Ival O. (Dayton, OH); Griffen, Charles W. (Mason, OH)

    1989-01-01

    A polymeric composition comprising a polymeric material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the composition is useful in making molded and/or coated materials such as flooring, tiles, wall panels and the like; paints containing polyethylene glycols or end-capped polyethylene glycols are also disclosed.

  4. Wood-Fiber/High-Density-Polyethylene Composites: Compounding Process

    E-Print Network [OSTI]

    Wood-Fiber/High-Density-Polyethylene Composites: Compounding Process J. Z. Lu,1 Q. Wu,1 I. I parameters for the wood-fiber/high-density-polyethylene blends at 60 rpm were a temperature of 180°C

  5. Exact Topological Twistons in Crystalline Polyethylene

    E-Print Network [OSTI]

    E. Ventura; A. M. Simas; D. Bazeia

    2000-04-04

    We investigate the presence of topological twistons in crystalline polyethylene. We describe crystalline polyethylene with a model that couples the torsional and longitudinal degrees of freedom of the polymeric chain by means of a system of two real scalar fields. This model supports topological twistons, which are described by exact and stable topological solutions that appear when the interaction between torsional and longitudinal fields is polynomial, containing up to the sixth power in the fields. We calculate the energy of the topological twiston, and the result is in very good agreement with the value obtained via molecular simulation.

  6. Thermal Expansion and Diffusion Coefficients of Carbon

    E-Print Network [OSTI]

    Wei, Chenyu

    Thermal Expansion and Diffusion Coefficients of Carbon Nanotube-Polymer Composites Chenyu Wei* NASA of carbon nanotube-polyethylene composites. Additions of carbon nanotubes to a polymer matrix are found for polymer-nanotube interface are used to investigate the thermal expansion and diffusion characteristics

  7. Design of a novel conduction heating based stress-thermal cycling apparatus for composite materials and its utilization to characterize composite microcrack damage thresholds 

    E-Print Network [OSTI]

    Ju, Jaehyung

    2006-10-30

    load causes fiber/matrix interface failure. Subsequent exposure to higher stresses in the cryogenic temperature region results in composite matrix microcracking due to the additional stresses associated with the fiber-matrix thermal expansion mismatch....

  8. Diamond Lattice Model of Semicrystalline Polyethylene in the Amorphous Region

    E-Print Network [OSTI]

    Diamond Lattice Model of Semicrystalline Polyethylene in the Amorphous Region Zhong­Hui Duan Abstract The statistics of polyethylene chains in the amorphous region between two crystallites have been as models of the chain molecules in the amorphous region of semicrystalline polyethylene, both

  9. Optical Properties and Orientation in Polyethylene Blown Films

    E-Print Network [OSTI]

    Beaucage, Gregory

    Optical Properties and Orientation in Polyethylene Blown Films AYUSH BAFNA,1 GREGORY BEAUCAGE,1 properties of blown poly- ethylene films. Two types of blown polyethylene films of similar degrees of crystallinity were made from (1) single-site-catalyst high-density polyethylene (HDPE; STAR ) and (2) Ziegler

  10. An Instability Leading to Failure of Polyethylene in Uniaxial Creep

    E-Print Network [OSTI]

    An Instability Leading to Failure of Polyethylene in Uniaxial Creep L. J. ZAPAS and J. M. CRISSMAN model, a point of instability is pre- dicted for the uniaxial creep of high density polyethylene. From dead load experiments it has been found that the instabil- ity occurs for linear -polyethylene

  11. Adsorption of Polypropylene and Polyethylene on Liquid Chromatographic

    E-Print Network [OSTI]

    Li, Jing

    Adsorption of Polypropylene and Polyethylene on Liquid Chromatographic Column Packings T. Macko1 tested as column packings for adsorption of isotactic polypropylene and linear polyethylene from dilute solutions. It was found that polyethylene is fully or partially retained from thermodynamically good sol

  12. NANO-SCALE CALORIMETRY OF ISOLATED POLYETHYLENE SINGLE CRYSTALS

    E-Print Network [OSTI]

    Allen, Leslie H.

    #12;NANO-SCALE CALORIMETRY OF ISOLATED POLYETHYLENE SINGLE CRYSTALS BY ALEX TAN KWAN B.S., Stanford) device, the nanocalorimeter, it was possible to investigate the melting of isolated polyethylene (PE, a simple Ni-foil calorimeter, to measure the heat capacity of a thin polyethylene film to verify

  13. Automated Assessment of Polyethylene Wear in Cemented Acetabular Components using

    E-Print Network [OSTI]

    Ulidowski, Irek

    Automated Assessment of Polyethylene Wear in Cemented Acetabular Components using Anteroposterior, Ninewells Hospital, Dundee, DD1 9SY, UK Abstract Polyethylene wear in the acetabular components of hip to the polyethylene acetabular component of a prosthesis so that both it and the metal femoral head component can

  14. Test method Evaluating the influence of contacting fluids on polyethylene

    E-Print Network [OSTI]

    Thompson, Michael

    Test method Evaluating the influence of contacting fluids on polyethylene using acoustic emissions emissions Polyethylene Penetrant Toluene Aqueous detergent a b s t r a c t Identifying microstructural) on the structure of a semi-crystalline polymer (high density polyethylene, HDPE) over different periods of exposure

  15. Irradiation effects in high-density polyethylene Jussi Polvia

    E-Print Network [OSTI]

    Nordlund, Kai

    Irradiation effects in high-density polyethylene Jussi Polvia , Kai Nordlunda a simulations, we have studied the irradiation effects in high density polyethylene. We determined the threshold for the hydrogen atoms in the polyethylene chain. Keywords: molecular dynamics, irradiation, damage threshold

  16. Solidification of commercial and defense low-level radioactive waste in polyethylene

    SciTech Connect (OSTI)

    Franz, E.M.; Heiser, L.H.; Colombo, P.

    1987-08-01

    A process was developed for the solidification of salt wastes, incinerator ash and ion-exchange resins in polyethylene. Of the salt wastes, sodium sulfate and boric acid are representative of the wastes produced at commercial nuclear facilities while sodium nitrate in a typical high-volume waste generated at defense-related facilities. Ease of processibility and high loading efficiencies were obtained through the use of low-density polyethylene with melt indices ranging from 2.0 to 55.0 g/minute. The process utilized a commercially available single-screw extruder to incorporate the wastes into the polyethylene at about 120/sup 0/C to produce a homogeneous mixture. Although present studies utilize dry wastes, wet wastes can also be processed using vented extruders of the type used commercially for the bitumen solidification process. Tests were performed on the waste forms to determine leachability and mechanical properties. To confirm the compatibility of polyethylene and nitrate salt waste at elevated temperatures, the self-ignition temperatures were measured and a differential scanning calorimeter was used to characterize the thermal behavior of oxidizing compounds contained in the simulated waste, as well as the real Savannah River Plant waste. No exothermic reactions were observed over the temperature range studied from 50/sup 0/C to 400/sup 0/C. 18 refs., 7 figs., 8 tabs.

  17. Polyethylene encapsulatin of nitrate salt wastes: Waste form stability, process scale-up, and economics

    SciTech Connect (OSTI)

    Kalb, P.D.; Heiser, J.H. III; Colombo, P.

    1991-07-01

    A polyethylene encapsulation system for treatment of low-level radioactive, hazardous, and mixed wastes has been developed at Brookhaven National Laboratory. Polyethylene has several advantages compared with conventional solidification/stabilization materials such as hydraulic cements. Waste can be encapsulated with greater efficiency and with better waste form performance than is possible with hydraulic cement. The properties of polyethylene relevant to its long-term durability in storage and disposal environments are reviewed. Response to specific potential failure mechanisms including biodegradation, radiation, chemical attack, flammability, environmental stress cracking, and photodegradation are examined. These data are supported by results from extensive waste form performance testing including compressive yield strength, water immersion, thermal cycling, leachability of radioactive and hazardous species, irradiation, biodegradation, and flammability. The bench-scale process has been successfully tested for application with a number of specific problem'' waste streams. Quality assurance and performance testing of the resulting waste form confirmed scale-up feasibility. Use of this system at Rocky Flats Plant can result in over 70% fewer drums processed and shipped for disposal, compared with optimal cement formulations. Based on the current Rocky Flats production of nitrate salt per year, polyethylene encapsulation can yield an estimated annual savings between $1.5 million and $2.7 million, compared with conventional hydraulic cement systems. 72 refs., 23 figs., 16 tabs.

  18. Surface modification of polyethylene by functionalized plasma

    SciTech Connect (OSTI)

    Yuan, S.; Marchant, R.E.

    1993-12-31

    The surface of low density polyethylene(PE) has been modified by functionalized plasma-polymerized N-vinyl-2-pyrrolidone (PPNVP) and allyl alcohol(PPAA) thin films, PPNVP and PPAA(approx. 100 nm). The surface structure and functional groups of modified surfaces were characterized by water contact angle, ATR/FTIR and ESCA techniques. Plasma polymer modified PE surfaces exhibited significant water contact angle hysteresis and a much lower value of advancing water contact angle than that of unmodified polyethylene. Reduction of PPNVP and PPAA modified surfaces by sodium borohydride coverted into hydroxyl groups. The determined concentrations of hydroxyl groups on the reduced PPNVP and PPAA modified surfaces by ESCA after gas-phase derivatization with trifluoroacetic anhydride (TFAA) were about 25% and 30% of total oxygen content, respectively. Finally, the amine containing molecules such as amine-terminated polyethylene oxide (PEO) and 3-aminopropyltriethoxysilane (APTS) were coupled to the hydroxylated surfaces. These novel modified PE surfaces are suitable for immobilization of biomolecules.

  19. Microstructure, Mechanical Behavior, and Clinical Trade-offs in Ultra-High Molecular Weight Polyethylene for Total Joint Replacement

    E-Print Network [OSTI]

    Atwood, Sara Anne

    2010-01-01

    analysis of hylamer and polyethylene bearings from retrieved1995). Stresses in polyethylene components of contemporaryof cross-linked polyethylene materials for orthopaedic

  20. Crystallization of polyethylene by modified weighted density approximation(MWDA)

    E-Print Network [OSTI]

    Razeghizadeh, Alireza; Lavafpour, Farhad

    2015-01-01

    In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.

  1. Crystallization of polyethylene by modified weighted density approximation(MWDA)

    E-Print Network [OSTI]

    Alireza Razeghizadeh; Vahdat Rafee; Farhad Lavafpour

    2015-02-07

    In this article, we use the modified weighted density approximation to study the crystallization of polyethylene. We also use a direct correlation function of polyethylene based on RISM theory. The free energy of a polyethylene is calculated using density functional theory. The crystallization and solid and liquid density are calculated and finally compared with the prism simulation and experimental results. That shown the result obtained by MWDA is in better agreement, compared with the experimental result than the prism.

  2. Metalized Polyethylene Mulch to Reduce Incidence of Huanglongbing and Improve Growth of New Citrus Plantings

    E-Print Network [OSTI]

    Croxton, S.; Stansly, P.

    2014-01-01

    7.14 P Metalized Polyethylene Mulch to Reduce Incidence ofNorth, Immokalee, FL, USA Polyethylene mulch was evaluatedUV reflective low density polyethylene mulch metalized with

  3. Leaching of antimony from polyethylene terephthalate (PET) bottles into mineral water

    E-Print Network [OSTI]

    Short, Daniel

    Leaching of antimony from polyethylene terephthalate (PET) bottles into mineral water Szilvia April 2009 Available online 21 May 2009 Keywords: Antimony Water Leaching Polyethylene terephthalate SODIS The Sb leaching from polyethylene terephthalate (PET) package material into 10 different brands

  4. Chemical compounds and toxicological assessments of drinking water stored in polyethylene terephthalate (PET)

    E-Print Network [OSTI]

    Short, Daniel

    Chemical compounds and toxicological assessments of drinking water stored in polyethyleneMS, gas chromatographyemass spectrometry; HDPE, high density polyethylene; HULYs, human blood lymphocytes

  5. Microrheology of polyethylene oxide using diffusing wave spectroscopy and single scattering Bivash R. Dasgupta,1

    E-Print Network [OSTI]

    Microrheology of polyethylene oxide using diffusing wave spectroscopy and single scattering Bivash on polyethylene oxide solutions in the semidilute regime using polystyrene beads of varying sizes and surface

  6. Extensional rheology of shear-thickening fumed silica nanoparticles dispersed in an aqueous polyethylene

    E-Print Network [OSTI]

    Rothstein, Jonathan

    polyethylene oxide solution Sunilkumar Khandavalli and Jonathan P. Rothsteina) Mechanical and Industrial rheology of fumed silica nanoparticles dispersed in an aqueous polyethylene oxide (PEO) solution

  7. Eccentricity Error Correction for Automated Estimation of Polyethylene Wear after Total Hip Arthroplasty

    E-Print Network [OSTI]

    Ulidowski, Irek

    Eccentricity Error Correction for Automated Estimation of Polyethylene Wear after Total Hip. Wire markers are typically attached to the polyethylene acetabular component of the prosthesis so

  8. Fracture mechanics analysis of slow crack growth in polyethylene 

    E-Print Network [OSTI]

    Self, Robert Alan

    1997-01-01

    Slow crack growth in polyethylene is often the limiting factor in long-term service of plastic pipe or other structural applications. A new test method and analysis method was developed to study slow crack growth in polyethylene. Two high density...

  9. Mesophases in polyethylene, polypropylene, and poly(1-butene)

    SciTech Connect (OSTI)

    Androsch, Rene J; Di Lorenzo, Maria; Schick, Christoph; Wunderlich, Bernhard {nmn}

    2010-01-01

    This paper contains new views about the amorphous and partially ordered phases of the three polymers listed in the title. The discussion is based on information on structure, thermodynamic stability, and large-amplitude molecular motion. Polyethylene is the basic backbone of all alkene polymers, and the other two are the first members of the vinyl polymers which have stereospecifically placed alkyl side chains. Their multiphase structures consist of metastable crystals, mesophases, and surrounding rigid and mobile amorphous fractions. All these phases have sizes ranging from micrometer dimensions down to nanometers. Besides the phase structures, information about the molecular coupling between the phases must be considered. Depending on temperature, the polymer phases can vary from solid (rigid) to liquid (mobile). New knowledge is also gained by cross-comparison of the title polymers. The experimental information was gained from (a) various forms of slow, fast, and temperature-modulated thermal analysis to identify equilibrium and non-equilibrium states, (b) measurement of structure and morphology at various length scales, and (c) tracing of the large-amplitude molecular motion, the kinetics of order/disorder changes, and the liquid/solid transitions (glass transitions). It is shown that much more needs to be known about the various phases and their coupling to characterize a given polymer and to fine-tune its properties for a given application.

  10. Single chain elasticity and thermoelasticity of polyethylene

    E-Print Network [OSTI]

    John T. Titantah; Carlo Pierleoni; Jean-Paul Ryckaert

    2002-09-05

    Single-chain elasticity of polyethylene at $\\theta$ point up to 90% of stretching with respect to its contour length is computed by Monte-Carlo simulation of an atomistic model in continuous space. The elasticity law together with the free-energy and the internal energy variations with stretching are found to be very well represented by the wormlike chain model up to 65% of the chain elongation, provided the persistence length is treated as a temperature dependent parameter. Beyond this value of elongation simple ideal chain models are not able to describe the Monte Carlo data in a thermodynamic consistent way. This study reinforces the use of the wormlike chain model to interpret experimental data on the elasticity of synthetic polymers in the finite extensibility regime, provided the chain is not yet in its fully stretched regime. Specific solvent effects on the elasticity law and the partition between energetic and entropic contributions to single chain elasticity are investigated.

  11. Recycling of wasted energy : thermal to electrical energy conversion

    E-Print Network [OSTI]

    Lim, Hyuck

    2011-01-01

    Recycling of Wasted Energy : Thermal to Electrical EnergyRecycling of Wasted Energy : Thermal to Electrical Energyelectric energy generation and thermal energy conduction

  12. Conduction cooled tube supports

    DOE Patents [OSTI]

    Worley, Arthur C. (Mt. Tabor, NJ); Becht, IV, Charles (Morristown, NJ)

    1984-01-01

    In boilers, process tubes are suspended by means of support studs that are in thermal contact with and attached to the metal roof casing of the boiler and the upper bend portions of the process tubes. The support studs are sufficiently short that when the boiler is in use, the support studs are cooled by conduction of heat to the process tubes and the roof casing thereby maintaining the temperature of the stud so that it does not exceed 1400.degree. F.

  13. High-Molecular-Weight Polyethylene Glycol Prevents Lethal Sepsis Due to Intestinal Pseudomonas aeruginosa

    E-Print Network [OSTI]

    Lee, Ka Yee C.

    High-Molecular-Weight Polyethylene Glycol Prevents Lethal Sepsis Due to Intestinal Pseudomonas of this study were to test the ability of a high-molecular- weight polyethylene glycol compound, polyethylene: The ability of polyethylene glycol 15­20 to protect the intestinal epi- thelium against the opportunistic

  14. Quantification of branching in model 3-arm star polyethylene Ramnath Ramachandran, Gregory Beaucage*

    E-Print Network [OSTI]

    Beaucage, Gregory

    1 Quantification of branching in model 3-arm star polyethylene Ramnath Ramachandran, Gregory-arm star polyethylene molecules is presented. Many commercial polyethylenes have long side branches-density polyethylene (LDPE) is typically a highly branched structure with broad distributions in branch content, branch

  15. Device for thermal transfer and power generation

    DOE Patents [OSTI]

    Weaver, Stanton Earl (Northville, NY); Arik, Mehmet (Niskayuna, NY)

    2011-04-19

    A system is provided. The system includes a device that includes top and bottom thermally conductive substrates positioned opposite to one another, wherein a top surface of the bottom thermally conductive substrate is substantially atomically flat and a thermal blocking layer disposed between the top and bottom thermally conductive substrates. The device also includes top and bottom electrodes separated from one another between the top and bottom thermally conductive substrates to define a tunneling path, wherein the top electrode is disposed on the thermal blocking layer and the bottom electrode is disposed on the bottom thermally conductive substrate.

  16. Thermal control structure and garment

    DOE Patents [OSTI]

    Klett, James W. (Knoxville, TN); Cameron, Christopher Stan (Sanford, NC)

    2012-03-13

    A flexible thermally conductive structure. The structure generally includes a plurality of thermally conductive yarns, at least some of which are at least partially disposed adjacent to an elastomeric material. Typically, at least a portion of the plurality of thermally conductive yarns is configured as a sheet. The yarns may be constructed from graphite, metal, or similar materials. The elastomeric material may be formed from urethane or silicone foam that is at least partially collapsed, or from a similar material. A thermal management garment is provided, the garment incorporating a flexible thermally conductive structure.

  17. High density polyethylene (HDPE) containers as an alternative to polyethylene terephthalate (PET) bottles for solar disinfection of drinking water in northern region, Ghana

    E-Print Network [OSTI]

    Yazdani, Iman

    2007-01-01

    The purpose of this study is to investigate the technical feasibility of high density polyethylene (HDPE) containers as an alternative to polyethylene terephthalate (PET) bottles for the solar disinfection of drinking water ...

  18. Microstructure changes and thermal conductivity reduction in...

    Office of Scientific and Technical Information (OSTI)

    after ion irradiation up to 51016 He2+cm2 at low-temperature (< 200 C). Transmission electron microscopy (TEM) showed homogenous irradiation damage across an 8 m...

  19. Thermal Conduction in Graphene and Graphene Multilayers

    E-Print Network [OSTI]

    Ghosh, Suchismita

    2009-01-01

    graphene . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .graphene . . . . . . . . . . . . . . . . . . . . . . . . .image of a typical single-layer graphene (SLG) on Si/SiO 2

  20. A Robust Approach to Lattice Thermal Conductivity

    E-Print Network [OSTI]

    Nielson, Weston Graham

    2015-01-01

    28 ensembles, 35 steps, 29 Peltier effect, 3 potentialseffect, called the Peltier effect, was discovered a fewyears later by a Charles Peltier. Instead of applying heat

  1. Thermal Conductivity of Polycrystalline Semiconductors and Ceramics

    E-Print Network [OSTI]

    Wang, Zhaojie

    2012-01-01

    Z. F. ; Chen, G. Energy & Environmental Science Chen, G. ;Z. F. ; Chen, G. Energy & Environmental Science Lan, Y. ;Z. F. ; Chen, G. Energy & Environmental Science Cronin, V. ,

  2. Thermal Conductivity of Polycrystalline Semiconductors and Ceramics

    E-Print Network [OSTI]

    Wang, Zhaojie

    2012-01-01

    Johnson, D. Advances in Ceramics 1987, 21, 3. Reed, J. S.Ganguli, D. ; Chatterjee, M. , Ceramic powder preparation: aRing, T. A. , Fundamentals of ceramic powder processing and

  3. Tunable thermal link

    DOE Patents [OSTI]

    Chang, Chih-Wei; Majumdar, Arunava; Zettl, Alexander K.

    2014-07-15

    Disclosed is a device whereby the thermal conductance of a multiwalled nanostructure such as a multiwalled carbon nanotube (MWCNT) can be controllably and reversibly tuned by sliding one or more outer shells with respect to the inner core. As one example, the thermal conductance of an MWCNT dropped to 15% of the original value after extending the length of the MWCNT by 190 nm. The thermal conductivity returned when the tube was contracted. The device may comprise numbers of multiwalled nanotubes or other graphitic layers connected to a heat source and a heat drain and various means for tuning the overall thermal conductance for applications in structure heat management, heat flow in nanoscale or microscale devices and thermal logic devices.

  4. Exciton self-trapping in bulk polyethylene

    E-Print Network [OSTI]

    D. Ceresoli; M. C. Righi; E. Tosatti; S. Scandolo; G. Santoro; S. Serra

    2005-07-13

    We studied theoretically the behavior of an injected electron-hole pair in crystalline polyethylene. Time-dependent adiabatic evolution by ab-initio molecular dynamics simulations show that the pair will become self-trapped in the perfect crystal, with a trapping energy of about 0.38 eV, with formation of a pair of trans-gauche conformational defects, three C$_2$H$_4$ units apart on the same chain. The electron is confined in the inter-chain pocket created by a local, 120$^\\circ$ rotation of the chain between the two defects, while the hole resides on the chain and is much less bound. Despite the large energy stored in the trapped excitation, there does not appear to be a direct non-radiative channel for electron-hole recombination. This suggests that intrinsic self-trapping of electron-hole pairs inside the ideal quasi-crystalline fraction of PE might not be directly relevant for electrical damage in high-voltage cables.

  5. Thermal Conductivity and Thermal Rectification in Graphene Nanoribbons

    E-Print Network [OSTI]

    Ruan, Xiulin

    flow in graphene nanostructures can be important for the development of energy-efficient nanoelec is the building block of most carbon-based nanomaterial, such as carbon nanotubes (CNTs) and buckyballs. Much

  6. A course-grained model for polyethylene glycol polymer

    SciTech Connect (OSTI)

    Nicholson, Don M [ORNL; Wang, Qifei [ORNL; Keffer, David J [ORNL

    2011-01-01

    A coarse-grained (CG) model of polyethylene glycol (PEG) was developed and implemented in CG molecular dynamics (MD) simulations of PEG chains with degree of polymerization (DP) 20 and 40. In the model, two repeat units of PEG are grouped as one CG bead. Atomistic MD simulation of PEG chains with DP = 20 was first conducted to obtain the bonded structural probability distribution functions (PDFs) and nonbonded pair correlation function (PCF) of the CG beads. The bonded CG potentials are obtained by simple inversion of the corresponding PDFs. The CG nonbonded potential is parameterized to the PCF using both an inversion procedure based on the Ornstein-Zernike equation with the Percus-Yevick approximation (OZPY{sup -1}) and a combination of OZPY{sup -1} with the iterative Boltzmann inversion (IBI) method (OZPY{sup -1}+IBI). As a simple one step method, the OZPY{sup -1} method possesses an advantage in computational efficiency. Using the potential from OZPY{sup -1} as an initial guess, the IBI method shows fast convergence. The coarse-grained molecular dynamics (CGMD) simulations of PEG chains with DP = 20 using potentials from both methods satisfactorily reproduce the structural properties from atomistic MD simulation of the same systems. The OZPY{sup -1}+IBI method yields better agreement than the OZPY{sup -1} method alone. The new CG model and CG potentials from OZPY{sup -1}+IBI method was further tested through CGMD simulation of PEG with DP = 40 system. No significant changes are observed in the comparison of PCFs from CGMD simulations of PEG with DP = 20 and 40 systems indicating that the potential is independent of chain length.

  7. Thermal properties of soils and soils testing

    SciTech Connect (OSTI)

    Not Available

    1981-02-17

    The thermal properties of soils are reviewed with reference to the use of soils as heat sources, heat sinks, or thermal storage. Specific heat and thermal conductivity are discussed. (ACR)

  8. Friction and Wear Behavior of Ultrahigh Molecular Weight Polyethylene as a Function of Crystallinity in the Presence of the

    E-Print Network [OSTI]

    Lin, Zhiqun

    Friction and Wear Behavior of Ultrahigh Molecular Weight Polyethylene as a Function: In this study, the friction and wear behavior of ultrahigh molecular weight polyethylene (UHMWPE) were evaluated Words: ultrahigh molecular weight polyethylene (UHMWPE), crystallinity, friction, wear, phospholipid

  9. Article for thermal energy storage

    DOE Patents [OSTI]

    Salyer, Ival O. (Dayton, OH)

    2000-06-27

    A thermal energy storage composition is provided which is in the form of a gel. The composition includes a phase change material and silica particles, where the phase change material may comprise a linear alkyl hydrocarbon, water/urea, or water. The thermal energy storage composition has a high thermal conductivity, high thermal energy storage, and may be used in a variety of applications such as in thermal shipping containers and gel packs.

  10. A high-pressure route to thermoelectrics with low thermal conductivity: The solid solution series AgIn{sub x}Sb{sub 1?x}Te{sub 2} (x=0.1–0.6)

    SciTech Connect (OSTI)

    Schröder, Thorsten; Rosenthal, Tobias; Souchay, Daniel; Petermayer, Christian; Grott, Sebastian; Scheidt, Ernst-Wilhelm; Gold, Christian; Scherer, Wolfgang; Oeckler, Oliver

    2013-10-15

    Metastable rocksalt-type phases of the solid solution series AgIn{sub x}Sb{sub 1?x}Te{sub 2} (x=0.1, 0.2, 0.4, 0.5 and 0.6) were prepared by high-pressure synthesis at 2.5 GPa and 400 °C. In these structures, the coordination number of In{sup 3+} is six, in contrast to chalcopyrite ambient-pressure AgInTe{sub 2} with fourfold In{sup 3+} coordination. Transmission electron microscopy shows that real-structure phenomena and a certain degree of short-range order are present, yet not very pronounced. All three cations are statistically disordered. The high degree of disorder is probably the reason why AgIn{sub x}Sb{sub 1?x}Te{sub 2} samples with 0.4thermal conductivities with a total ?<0.5 W/K m and a lattice contribution of ?{sub ph} ?0.3 W/K m at room temperature. These are lower than those of other rocksalt-type tellurides at room temperature; e.g. the well-known thermoelectric AgSbTe{sub 2} (? ?0.6 W/K m). The highest ZT value (0.15 at 300 K) is observed for AgIn{sub 0.5}Sb{sub 0.5}Te{sub 2}, mainly due to its high Seebeck coefficient of 160 µV/K. Temperature-dependent X-ray powder patterns indicate that the solid solutions are metastable at ambient pressure. At 150 °C, the quaternary compounds decompose into chalcopyrite-type AgInTe{sub 2} and rocksalt-type AgSbTe{sub 2}. - Graphical abstract: Reaction scheme, temperature characteristics of the ZT value and a selected-area electron diffraction pattern (background) of AgIn{sub 0.5}Sb{sub 0.5}Te{sub 2}, which crystallizes in a rocksalt-type structure with statistical cation disorder. Display Omitted - Highlights: • High-pressure synthesis yields the novel solid solution series AgIn{sub x}Sb{sub 1?x}Te{sub 2}. • In contrast to AgInTe{sub 2}, the compounds are inert at ambient pressure. • HRTEM shows no pronounced short-range order in the disordered NaCl-type structure. • The metastable phases exhibit very low total thermal conductivities <0.5 W/K m. • ZT values of 0.15 at room temperature were measured for AgIn{sub 0.5}Sb{sub 0.5}Te{sub 2}.

  11. Towards a detailed understanding of the NEXAFS spectra of bulk polyethylene copolymers and related alkanes

    E-Print Network [OSTI]

    Towards a detailed understanding of the NEXAFS spectra of bulk polyethylene copolymers and related interpretation has not yet emerged. Initially, the low energy peak of polyethylene (PE) and long- chain alkanes

  12. Synthesis and elaboration of polyethylene surfaces modified via anionic grafting chemistry 

    E-Print Network [OSTI]

    Bandella, Ashok Krishangopal

    1996-01-01

    such as contact angle goniometry, X-ray photoelectron spectroscopy, and ATR-IR spectroscopy showed that grafting took place mainly on the surface of polyethylene film. Detailed spectroscopic studies of the ungrafted and grafted polyethylene surfaces containing...

  13. Modeling and simulation of Li-ion conduction in poly(ethylene oxide)

    E-Print Network [OSTI]

    Averbuch, Amir

    rechargeable batteries for consumer portable applications. A lithium-ion battery employs a metal oxide/discharge voltage depends on the current and resistance of all battery components. In most solid-state lithium-ion of Computational Physics 227 (2007) 1162­1175 www.elsevier.com/locate/jcp #12;1. Introduction Lithium and lithium-ion

  14. Thermal protection apparatus

    DOE Patents [OSTI]

    Bennett, G.A.; Elder, M.G.; Kemme, J.E.

    1984-03-20

    The disclosure is directed to an apparatus for thermally protecting sensitive components in tools used in a geothermal borehole. The apparatus comprises a Dewar within a housing. The Dewar contains heat pipes such as brass heat pipes for thermally conducting heat from heat sensitive components such as electronics to a heat sink such as ice.

  15. Thermal protection apparatus

    DOE Patents [OSTI]

    Bennett, Gloria A. (Los Alamos, NM); Elder, Michael G. (Los Alamos, NM); Kemme, Joseph E. (Albuquerque, NM)

    1985-01-01

    An apparatus which thermally protects sensitive components in tools used in a geothermal borehole. The apparatus comprises a Dewar within a housing. The Dewar contains heat pipes such as brass heat pipes for thermally conducting heat from heat sensitive components to a heat sink such as ice.

  16. Rice Straw Fiber Reinforced High Density Polyethylene Composite: Effect of Coupled Compatibilizating and

    E-Print Network [OSTI]

    Rice Straw Fiber Reinforced High Density Polyethylene Composite: Effect of Coupled polyethylene (HDPE) composites were manufactured by extrusion and injection molding. Three compatibilizers compatibilizers, ma- leic anhydride grafted polyethylene and polypropylene (PE-g-MA and PP-g-MA) are considered

  17. PHYSICAL REVIEW B 85, 094109 (2012) Electron dynamics of shocked polyethylene crystal

    E-Print Network [OSTI]

    Goddard III, William A.

    2012-01-01

    PHYSICAL REVIEW B 85, 094109 (2012) Electron dynamics of shocked polyethylene crystal Patrick L-dynamics simulations of the single shock Hugoniot are reported for a crystalline polyethylene (PE) model. The e. INTRODUCTION The material response of polyethylene (PE) to shock and its behavior in the warm dense matter (WDM

  18. Rheology of Low-Density Polyethylene Boehmite Piotr Blaszczak,1,2

    E-Print Network [OSTI]

    North Texas, University of

    Rheology of Low-Density Polyethylene þ Boehmite Composites Piotr Blaszczak,1,2 Witold Brostow,1), University of North Texas, Denton 76203-5017, Texas Polyethylene is already one of the most commonly used polymers due to its solvent resistance and easy processing. Low-density polyethylene (LDPE) also has

  19. Metalized Polyethylene Mulch to Reduce Incidence of Huanglongbing and Improve Growth of New Citrus Plantings

    E-Print Network [OSTI]

    Ma, Lena

    7.14 P Metalized Polyethylene Mulch to Reduce Incidence of Huanglongbing and Improve Growth of New and Education Center Polyethylene mulch was evaluated for deterring colonization by Asian citrus psyllid (ACP growth of young citrus. UV reflective low density polyethylene mulch metalized with aluminum, low density

  20. Creep Failure and Fracture of Polyethylene in Uniaxial J. M. CRISSMAN and L. J. ZAPAS

    E-Print Network [OSTI]

    Creep Failure and Fracture of Polyethylene in Uniaxial Extension J. M. CRISSMAN and L. J. ZAPAS conditions of uniaxial creep the frac- ture of high density polyethylene can be categorized as one of three, this phenomenon is known as dead load fatigue. In the case of polyethylene the ultimate fracture can

  1. Crystallographic texture evolution in high-density polyethylene during uniaxial tension

    E-Print Network [OSTI]

    Garmestani, Hamid

    Crystallographic texture evolution in high-density polyethylene during uniaxial tension D. Lia , H experimental measurements of crystallographic texture evolution in high-density polyethylene subjected to very straining of high-density polyethylene to large strains. There are at least three distinct preferred

  2. Reduced adhesion of human blood platelets to polyethylene tubing by microplasma surface modification

    E-Print Network [OSTI]

    von Andrian, Ulrich H.

    Reduced adhesion of human blood platelets to polyethylene tubing by microplasma surface of small-diameter polyethylene (PE) tubing. A microwave cavity diagnostic was used to measure the density tubing and the emitted light intensity was found. A poly(ethylene oxide) surfactant was immobilized

  3. Effect of polyethylene glycol on the liquidliquid phase transition in aqueous protein solutions

    E-Print Network [OSTI]

    Benedek, George B.

    Effect of polyethylene glycol on the liquid­liquid phase transition in aqueous protein solutions, 2002 We have studied the effect of polyethylene glycol (PEG) on the liquid­liquid phase separation. PEG ternary mixtures solubility partitioning Polyethylene glycol (PEG) is a hydrophilic nonionic

  4. Substrate Effect on the Melting Temperature of Thin Polyethylene Films M. Rafailovich,1,* J. Sokolov,1

    E-Print Network [OSTI]

    Substrate Effect on the Melting Temperature of Thin Polyethylene Films Y. Wang,1 M. Rafailovich,1 polyethylene thin films. The Tm decreases with the film thickness decrease when the film is thinner than that the degree of crystal- linity of polyethylene (PE) remained high even in films as thin as 15 nm [5]. A novel

  5. Comparison of low-energy radiation effects in polyethylene and cellulose Jussi Polvi, Kai Nordlund

    E-Print Network [OSTI]

    Nordlund, Kai

    Comparison of low-energy radiation effects in polyethylene and cellulose Jussi Polvi, Kai Nordlund, for a carbon atom in polyethylene chain, and for one of the carbon atoms in cellulose chain. Our analysis shows and on average slightly higher for the carbon atoms in the polyethylene chain than for the target carbon atom

  6. Leaf Area Distribution of Tomato Plants as Influenced by Polyethylene Mulch

    E-Print Network [OSTI]

    Decoteau, Dennis R.

    Leaf Area Distribution of Tomato Plants as Influenced by Polyethylene Mulch Surface Color Dennis R of polyethylene (plastic) mulch surface color (white versus black) on leaf area distribution of tomato and soil temperatures. These results suggest that the polyethylene mulch surface color can induce changes

  7. Defect controlled transverse compressive strength of polyethylene fiber M.R. O'Masta a,

    E-Print Network [OSTI]

    Wadley, Haydn

    Defect controlled transverse compressive strength of polyethylene fiber laminates M.R. O'Masta a: Laminate defects Voids Compressive strength Polyethylene composites a b s t r a c t Using a combination weight polyethylene (UHMWPE) fibers and thermoplastic resins, and investi- gated their effects upon

  8. Primary Radiation Defect Production in Polyethylene and Cellulose Jussi Polvi,* Petri Luukkonen, and Kai Nordlund

    E-Print Network [OSTI]

    Nordlund, Kai

    Primary Radiation Defect Production in Polyethylene and Cellulose Jussi Polvi,* Petri Luukkonen in polyethylene and cellulose were examined using molecular dynamics simulations. The governing reactions in both. Crystalline cellulose was found to be more resistant to radiation damage than crystalline polyethylene

  9. A study of the polyethylene membrane used in diffusion chambers for radon gas concentration measurements

    E-Print Network [OSTI]

    Yu, Peter K.N.

    A study of the polyethylene membrane used in diffusion chambers for radon gas concentration. Thoron can also be deterred from entering the diffusion chamber by using a polyethylene (PE) membrane rights reserved. PACS: 29.40; 23.60 Keywords: Diffusion chamber; Polyethylene membrane; Radon and thoron

  10. Hypothetical Thermodynamic Properties: The Boiling and Critical Temperatures of Polyethylene and Polytetrafluoroethylene

    E-Print Network [OSTI]

    Chickos, James S.

    Hypothetical Thermodynamic Properties: The Boiling and Critical Temperatures of Polyethylene value asymptotically approaches TB() ) (1217 ( 246) K for series related to polyethylene by the melting temperature of polyethylene.4,5 In this article, the question of whether the normal boiling tem

  11. MEASUREMENT OF HEAT TRANSFER DURING DROP-WISE CONDENSATION OF WATER ON POLYETHYLENE

    E-Print Network [OSTI]

    Khandekar, Sameer

    MEASUREMENT OF HEAT TRANSFER DURING DROP-WISE CONDENSATION OF WATER ON POLYETHYLENE Gagan Deep distribution of temperature during drop-wise condensation over a polyethylene substrate was measured using on the substrate was simultaneously visualized. Static contact angles of water on polyethylene are measured

  12. Density functional study of molecular crystals: Polyethylene and a crystalline analog of bisphenol-A polycarbonate

    E-Print Network [OSTI]

    Density functional study of molecular crystals: Polyethylene and a crystalline analog of bisphenol polyethylene comprising covalently bonded parallel chains with weak interchain interactions, and b reaction barriers.8 In a recent study of the interchain interactions in crystalline polyethylene PE ,9 we

  13. A MODIFIED GAMBLER'S RUIN MODEL POLYETHYLENE CHAINS IN THE AMORPHOUS REGION

    E-Print Network [OSTI]

    A MODIFIED GAMBLER'S RUIN MODEL OF POLYETHYLENE CHAINS IN THE AMORPHOUS REGION Zhong­Hui Duan and Louis N. Howard Department of Mathematics The Florida State University ABSTRACT. Polyethylene chainsM 3 +O(M 2 ). INTRODUCTION Semicrystalline polyethylene formed from melt generally consists

  14. Macromolecules 1991,24, 5687-5694 5687 Characterization of Molecular Orientation in Polyethylene by

    E-Print Network [OSTI]

    Pezolet, Michel

    Macromolecules 1991,24, 5687-5694 5687 Characterization of Molecular Orientation in Polyethylene bonds in thick processed samples of polyethylene. Introduction In order to take full advantage to the production of high-modulusfibersandfilms. High-density polyethylene isoneof the polymers that has been used

  15. P-7 / D. R. Cairns P-7: Wear Resistance of Indium Tin Oxide Coatings on Polyethylene

    E-Print Network [OSTI]

    Cairns, Darran

    P-7 / D. R. Cairns P-7: Wear Resistance of Indium Tin Oxide Coatings on Polyethylene Terephthalate The wear mechanisms of the Indium Tin Oxide (ITO) coated Polyethylene Terephthalate (PET) topsheet). The bottom substrate is typically glass and the top sheet a polyester such as Polyethylene Terephthalate (PET

  16. DSC Evidence for Microstructure and Phase Transitions in Polyethylene Melts at High Temperatures

    E-Print Network [OSTI]

    Hussein, Ibnelwaleed A.

    DSC Evidence for Microstructure and Phase Transitions in Polyethylene Melts at High Temperatures polyethylenes of types HDPE, LDPE, and LLDPE. DSC data were obtained for a range of heating and cooling rates previous rheology findings of order and high-temperature transitions in polyethylene melts. Introduction

  17. Association of hydrophobically-modified poly(ethylene glycol) with fusogenic liposomes

    E-Print Network [OSTI]

    Auguste, Debra T.

    interactions to shield liposomes by incorporating multiple hydrophobic anchoring sites on polyethylene glycolAssociation of hydrophobically-modified poly(ethylene glycol) with fusogenic liposomes Debra T, the equilibrium constant for distearoylphosphatidylethanolamine- poly(ethylene glycol) (DSPE-PEG5k) was 0.4F0

  18. Optimization For Grade Transitions In Polyethylene Solution Polymerization

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    , Comonomer, Catalyst, Solvent, Hydrogen 2 1. Che I Kao et al. Non-adiabatic olefin solution polymerizationOptimization For Grade Transitions In Polyethylene Solution Polymerization Jun Shi1, Lorenz T of Advanced Process Decision-making Department of Chemical Engineering Carnegie Mellon University 2The Dow

  19. Optimization For Grade Transitions In Polyethylene Solution Polymerization

    E-Print Network [OSTI]

    Grossmann, Ignacio E.

    Optimization For Grade Transitions In Polyethylene Solution Polymerization Jun Shi1, Intan Hamdan2, Sarat Munjal2, Lorenz T. Biegler1 1Center of Advanced Process Decision-making Department of Chemical perfect mixing · Three types of variables · Manipulated variables · Ethylene, comonomer, hydrogen

  20. Hybrid Polyethylene Glycol Hydrogels for Tissue Engineering Applications 

    E-Print Network [OSTI]

    Munoz Pinto, Dany 1981-

    2012-07-11

    modification of poly(ethylene glycol) hydrogels for tissue engineering? by Junmin Zhu, 2010, Biomaterials 31(17):4639-4656, Copyright 2010, Elsevier Limited. 4 Poly (ethylene glycol) (PEG) hydrogels can be used as a platform in 3D environments in order...

  1. Poly(ethylene glycol)-Modified Ligninase Enhances Pentachlorophenol

    E-Print Network [OSTI]

    Wang, Ping

    Poly(ethylene glycol)-Modified Ligninase Enhances Pentachlorophenol Biodegradation in Water-mail: ekn@ornl.gov Received 7 May 1998; accepted 5 December 1998 Abstract: Polychlorinated hydrocarbons are prevalent environmental contaminants whose rates of biodegrada- tion are limited by their minimal

  2. ORIGINAL PAPER BambooFiber Filled High Density Polyethylene Composites

    E-Print Network [OSTI]

    strength, bending modulus and strength were improved with the use of MAPE. The use of the clayORIGINAL PAPER Bamboo­Fiber Filled High Density Polyethylene Composites: Effect of Coupling to achieve clay exfoliation. For pure HDPE system, both dynamic and static bending moduli increased, while

  3. RESEARCH ARTICLE Biodegradable mulch instead of polyethylene for weed

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of biodegradable plastic mulch, black, 15 m, (6) oxo-degradable plastic mulch, black, 15 m, (7) paper mulch, black mulches and PE ranging between 80% and 100% for all of them; also, yield was similar for all plasticRESEARCH ARTICLE Biodegradable mulch instead of polyethylene for weed control of processing tomato

  4. Thermal properties of the hybrid graphene-metal nano-micro-composites: Applications in thermal interface materials

    E-Print Network [OSTI]

    Thermal properties of the hybrid graphene-metal nano-micro-composites: Applications in thermal) The authors report on synthesis and thermal properties of the electrically conductive thermal interface materials with the hybrid graphene-metal particle fillers. The thermal conductivity of resulting composites

  5. Production and characterization of a composite insulation material from waste polyethylene teraphtalates

    SciTech Connect (OSTI)

    Kurtulmus, Erhan; Karaboyac?, Mustafa; Yigitarslan, Sibel

    2013-12-16

    The pollution of polyethylene teraphtalate (PET) is in huge amounts due to the most widely usage as a packaging material in several industries. Regional pumice has several desirable characteristics such as porous structure, low-cost and light-weight. Considering the requirements approved by the Ministry of Public Works on isolation, composite insulation material consisting of PET and pumice was studied. Sheets of composites differing both in particle size of pumice and composition of polymer were produced by hot-molding technique. Characterization of new composite material was achieved by measuring its weight, density, flammability, endurance against both to common acids and bases, and to a force applied, heat insulation and water adsorption capacity. The results of the study showed that produced composite material is an alternative building material due to its desirable characteristics; low weight, capability of low heat conduction.

  6. Sensitivity of the interpretation of the experimental ion thermal...

    Office of Scientific and Technical Information (OSTI)

    thermal diffusivity to the determination of the ion conductive heat flux A moments equation formalism for the interpretation of the experimental ion thermal diffusivity from...

  7. Molecular dynamics simulation of chains mobility in polyethylene crystal

    E-Print Network [OSTI]

    V. I. Sultanov; V. V. Atrazhev; D. V. Dmitriev; S. F. Burlatsky

    2014-01-17

    The mobility of polymer chains in perfect polyethylene (PE) crystal was calculated as a function of temperature and chain length through Molecular dynamics (MD) in united atom approximation. The results demonstrate that the chain mobility drastically increases in the vicinity of the phase transition from the orthorhombic to quasi-hexagonal phase. In the quasi-hexagonal phase, the chain mobility is almost independent on temperature and inversely proportional to the chain length.

  8. Void morphology in polyethylene/carbon black composites

    SciTech Connect (OSTI)

    Marr, D.W.M.; Wartenberg, M.; Schwartz, K.B.

    1996-12-31

    A combination of small angle neutron scattering (SANS) and contrast matching techniques is used to determine the size and quantity of voids incorporated during fabrication of polyethylene/carbon black composites. The analysis used to extract void morphology from SANS data is based on the three-phase model of microcrack determination via small angle x-rayscattering (SAXS) developed by W.Wu{sup 12} and applied to particulate reinforced composites.

  9. Thermal ignition combustion system

    DOE Patents [OSTI]

    Kamo, Roy (Columbus, IN); Kakwani, Ramesh M. (Columbus, IN); Valdmanis, Edgars (Columbus, IN); Woods, Melvins E. (Columbus, IN)

    1988-01-01

    The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m.degree. C. and a specific heat greater than 480 J/kg.degree. C. with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber.

  10. Thermal ignition combustion system

    DOE Patents [OSTI]

    Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

    1988-04-19

    The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m C and a specific heat greater than 480 J/kg C with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber. 8 figs.

  11. Cementitious building material incorporating end-capped polyethylene glycol as a phase change material

    DOE Patents [OSTI]

    Salyer, Ival O. (Dayton, OH); Griffen, Charles W. (Mason, OH)

    1986-01-01

    A cementitious composition comprising a cementitious material and polyethylene glycol or end-capped polyethylene glycol as a phase change material, said polyethylene glycol and said end-capped polyethylene glycol having a molecular weight greater than about 400 and a heat of fusion greater than about 30 cal/g; the compositions are useful in making pre-formed building materials such as concrete blocks, brick, dry wall and the like or in making poured structures such as walls or floor pads; the glycols can be encapsulated to reduce their tendency to retard set.

  12. On conduction, cooling flows and galaxy formation

    E-Print Network [OSTI]

    Fabian, A C; Morris, R G

    2002-01-01

    On the basis of the universal gas fraction in clusters of galaxies, we estimate that the effective thermal conductivity required to balance radiative cooling in the cores, where the gas temperature is 3-10keV, is about one tenth of the Spitzer rate. This confirms that thermal conduction can be important for the energy balance provided that it is not highly suppressed by magnetic fields in the gas. We determine the global effective conductivity in a sample of 29 clusters using published X-ray data on the inferred cooling rates and show that most lie between one and one tenth of the Spitzer rate. More work on the profiles in cooling flow clusters is required to test the conduction hypothesis further. We examine the possibility that conduction operates during galaxy formation, and show that it provides a simple explanation for the upper-mass cutoff in galaxy masses.

  13. On conduction, cooling flows and galaxy formation

    E-Print Network [OSTI]

    A. C. Fabian; L. M. Voigt; R. G. Morris

    2002-06-25

    On the basis of the universal gas fraction in clusters of galaxies, we estimate that the effective thermal conductivity required to balance radiative cooling in the cores, where the gas temperature is 3-10keV, is about one tenth of the Spitzer rate. This confirms that thermal conduction can be important for the energy balance provided that it is not highly suppressed by magnetic fields in the gas. We determine the global effective conductivity in a sample of 29 clusters using published X-ray data on the inferred cooling rates and show that most lie between one and one tenth of the Spitzer rate. More work on the profiles in cooling flow clusters is required to test the conduction hypothesis further. We examine the possibility that conduction operates during galaxy formation, and show that it provides a simple explanation for the upper-mass cutoff in galaxy masses.

  14. Thermal and Electrical Transport in Oxide Heterostructures

    E-Print Network [OSTI]

    Ravichandran, Jayakanth

    2011-01-01

    2.3.1 Electrical transport . . . . . . . . . . . . . . . .3.5 Controlling electrical conductivity and opticalthe variation of electrical and thermal con- ductivity and

  15. Schottky and other electrical phenomena in polyethylene crystals 

    E-Print Network [OSTI]

    Stoltz, Richard Joseph

    1970-01-01

    fields to 2&c applie&1 ac ros s the alumi? num-polyethylene-aluminum sandwich (I ig 7). Each step of sample preparation is photographed to allow determination of the area, of the crystal between the electrodes as well as to provide visual evidence... thickness can be calculated. 2 P i y[ if'yLf="I= ? ? --~ GLASS SLI!)i- ll; '/41. '-/~ / L~Z 1, ' / / //y. '. ', , j; / / / IAICA ~ ALIIlIIfIIIlI SUBSTRATF. Technique oi mas1 in' crystals. Top view. ALUfll NUi'i ALUf'l I 'JUIAI z 'J~ GLASS 9'ig. 7...

  16. Deuterated polyethylene coatings for ultra-cold neutron applications

    E-Print Network [OSTI]

    Altarev, I; Fierlinger, P; Geltenbort, P; Gutsmiedl, E; Kuchler, F; Lauer, T; Lins, T; Marino, M G; Niessen, B; Petzoldt, G; Ruhstorfer, D; Seeman, K M; Soltwedel, O; Stuiber, St; Taubenheim, B; Windmayer, D; Zechlau, T

    2015-01-01

    We report on the fabrication and use of deuterated polyethylene (dPE) as a coating material for ultra-cold neutron (UCN) storage and transport. The Fermi potential has been determined to be 214 neV and the wall loss coefficient $\\eta$ is 2$\\cdot$10$^4$ per wall collision. The coating technique allows for a wide range of applications and new possibilities in this field of physics. In particular, flexible and quasi-massless UCN guides with slit-less shutters and slit-less UCN storage volumes become possible. These properties enable the use in next-generation measurements of the electric dipole moment of the neutron.

  17. Highly conductive PEDOT:PSS on flexible substrate as ITO-free anode for polymer solar cells

    SciTech Connect (OSTI)

    Del Mauro, A. De Girolamo; Ricciardi, R.; Montanino, M.; Morvillo, P.; Minarini, C. [Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Portici Research Centre, p.le E. Fermi 1, 80055 Portici (Italy)

    2014-05-15

    In this work, highly conductive anode based on PEDOT:PSS is proposed as substitute of Indio-Tin Oxide (ITO) in flexible solar cells. The anodic conductive polymer was spin coated on a 125 ?m thick polyethylene naphthalate (PEN) substrate. The obtained film was characterized in terms of structure and physical- chemical proprieties. The obtained results are very promising and the conductive film will be investigated in future as electrode in a complete polymeric solar cell.

  18. Dosimetry in Thermal Neutron Irradiation Facility at BMRR

    SciTech Connect (OSTI)

    Hu, J. P.; Holden, N. E.; Reciniello, R. N.

    2014-05-23

    Radiation dosimetry for Neutron Capture Therapy (NCT) has been performed since 1959 at Thermal Neutron Irradiation Facility (TNIF) of the three-megawatt light-water cooled Brookhaven Medical Research Reactor (BMRR). In the early 1990s when more effective drug carriers were developed for NCT, in which the eye melanoma and brain tumors in rats were irradiated in situ, extensive clinical trials of small animals began using a focused thermal neutron beam. To improve the dosimetry at irradiation facility, a series of innovative designs and major modifications made to enhance the beam intensity and to ease the experimental sampling at BMRR were performed; including (1) in-core fuel addition to increase source strength and balance flux of neutrons towards two ports, (2) out of core moderator remodeling, done by replacing thicker D2O tanks at graphite-shutter interfacial areas, to expedite neutron thermalization, (3) beam shutter upgrade to reduce strayed neutrons and gamma dose, (4) beam collimator redesign to optimize the beam flux versus dose for animal treatment, (5) beam port shielding installation around the shutter opening area (lithium-6 enriched polyester-resin in boxes, attached with polyethylene plates) to reduce prompt gamma and fast neutron doses, (6) sample holder repositioning to optimize angle versus distance for a single organ or whole body irradiation, and (7) holder wall buildup with neutron reflector materials to increase dose and dose rate from scattered thermal neutrons. During the facility upgrade, reactor dosimetry was conducted using thermoluminescent dosimeters TLD for gamma dose estimate, using ion chambers to confirm fast neutron and gamma dose rate, and by the activation of gold-foils with and without cadmium-covers, for fast and thermal neutron flux determination. Based on the combined effect from the size and depth of tumor cells and the location and geometry of dosimeters, the measured flux from cadmium-difference method was 4 - 7 % lower than the statistical mean derived from the Monte-Carlo modeling (5% uncertainty). The dose rate measured by ion chambers was 6 - 10 % lower than the output tallies (7% uncertainty). The detailed dosimetry that was performed at the TNIF for the NCT will be described.

  19. Production of Polyethylene Terephthalate using a Nonmetallic Catalyst Dr. Marsha Winston1, Jared Langson2, Angus Ferguson2, Dr. Robert Posey2

    E-Print Network [OSTI]

    Production of Polyethylene Terephthalate using a Nonmetallic Catalyst Dr. Marsha Winston1, Jared Department of Chemistry Polyethylene terephthalate (PET) is a condensation polymer of terephthalic acid (HOOC

  20. Polyethylene glycol (PEG) is a hydrophilic polymer that has been used for many years to fuse the membranes of various

    E-Print Network [OSTI]

    Duerstock, Bradley

    Polyethylene glycol (PEG) is a hydrophilic polymer that has been used for many years to fuse spinal cord injury. This involves a brief application of polyethylene glycol (PEG) to the site of injury

  1. Ion-Induced Nucleation of Dibutyl Phthalate Vapors on Spherical and Nonspherical Singly and Multiply Charged Polyethylene Glycol Ions

    E-Print Network [OSTI]

    and Multiply Charged Polyethylene Glycol Ions Albert G. Nasibulin,*, Juan Fernandez de la Mora, and Esko I by positive polyethylene glycol (PEG) ions with controlled sizes and charges was experimentally studied

  2. This article is protected by copyright. All rights reserved. Metalized Polyethylene Mulch to Repel Asian Citrus Psyllid, Slow Spread of

    E-Print Network [OSTI]

    Ma, Lena

    This article is protected by copyright. All rights reserved. Metalized Polyethylene Mulch to Repel to the disease. We tested the ability of metalized polyethylene mulch to repel adult ACP as well as effects

  3. Adhesion energy in carbon nanotube-polyethylene composite: Effect of chirality

    E-Print Network [OSTI]

    Garmestani, Hamid

    Adhesion energy in carbon nanotube-polyethylene composite: Effect of chirality M. Al-Haik and M. Y 2005 This work presents a study of the adhesion energy between carbon nanotube-polyethylene matrix nanotube chirality on adhesion energy. It is observed that composites that utilize nanotubes with smaller

  4. Composite Polymer Electrolytes Based on Poly(ethylene glycol) and Hydrophobic Fumed Silica: Dynamic

    E-Print Network [OSTI]

    Raghavan, Srinivasa

    Composite Polymer Electrolytes Based on Poly(ethylene glycol) and Hydrophobic Fumed Silica: Dynamic are used to probe the microstructures present in fumed silica-based composite polymer electrolytes electrolytes based on poly(ethylene oxide) (PEO).1 Solid polymer electrolytes can potentially eliminate battery

  5. Shape stabilised phase change materials (SSPCMs): High density polyethylene and hydrocarbon waxes

    SciTech Connect (OSTI)

    Mu, Mulan, E-mail: mmu01@qub.ac.uk, E-mail: m.basheer@qub.ac.uk; Basheer, P. A. M., E-mail: mmu01@qub.ac.uk, E-mail: m.basheer@qub.ac.uk [School of Planning, Architecture and Civil Engineering, Queen's University Belfast, BT9 5AG (United Kingdom); Bai, Yun, E-mail: yun.bai@ucl.ac.uk [Department of Civil, Environmental and Geomatic Engineering, University College London, WC1E 6BT (United Kingdom); McNally, Tony, E-mail: t.mcnally@warwick.ac.uk [WMG, University of Warwick, CV4 7AL (United Kingdom)

    2014-05-15

    Shape stabilised phase change materials (SSPCMs) based on high density polyethylene (HDPE) with high (HPW, T{sub m}=56-58 °C) and low (L-PW, T{sub m}=18-23 °C) melting point waxes were prepared by melt-mixing in a twin-screw extruder and their potential in latent heat thermal energy storage (LHTES) applications for housing assessed. The structure and morphology of these blends were investigated by scanning electron microscopy (SEM). Both H-PW and L-PW were uniformly distributed throughout the HDPE matrix. The melting point and latent heat of the SSPCMs were determined by differential scanning calorimetry (DSC). The results demonstrated that both H-PW and L-PW have a plasticisation effect on the HDPE matrix. The tensile and flexural properties of the samples were measured at room temperature (RT, 20±2 °C) and 70 °C, respectively. All mechanical properties of HDPE/H-PW and HDPE/L-PW blends decreased from RT to 70 °C. In all instances at RT, modulus and stress, irrespective of the mode of deformation was greater for the HDPE/H-PW blends. However, at 70 °C, there was no significant difference in mechanical properties between the HDPE/H-PW and HDPE/L-PW blends.

  6. Microphase separated structures in the solid and molten states of double-crystal graft copolymers of polyethylene and poly(ethylene oxide)

    SciTech Connect (OSTI)

    Mark, P.R.; Murthy, N.S.; Weigand, S.; Breitenkamp, K.; Kade, M.; Emrick, T. (Vermont); (NWU); (UMASS, Amherst)

    2008-08-26

    Transitions from one microphase separated structure in the solid state to a different one in the molten state in polyethylene-graft-poly(ethylene oxide) copolymers, PE-g-PEO, were investigated by variable temperature X-ray scattering measurements and thermal analyses. Small-angle X-ray scattering patterns from polymers with PEO grafts with 25, 50 and 100 ethylene oxide (EO) units show that the polymer passes through three distinct structures at {approx}10 nm length scales with increase in temperature (T): lamellar structures of PE and PEO at T < T{sub m}{sup PEO}, PE lamellae surrounded by molten PEO at T{sub m}{sup PEO} < T < T{sub m}{sup PE}, and microphase separated structures at T > T{sub m}{sup PE} when both PE and PEO are molten (T{sub m} refers to the melting temperature). These phase transformations also occur during cooling but with hysteresis. Crystalline phases of PEO side chains and PE main chains could be identified in the wide-angle X-ray diffraction profiles indicating that the PE backbone and PEO grafts crystallize into separate domains, especially with longer grafted chains (50 and 100 units). At EO segment lengths >50, PEO shows the expected increase in melting and crystallization temperatures with the increase in the grafted chain length. PE does not affect T{sub m}{sup PEO} but does decrease the onset of crystallization upon cooling. PEO grafts result in fractionation of PE, decrease the melting point of PE and increase the undercooling for the onset of crystallization of PE.

  7. MacroCapTM SP is a cation exchanger designed for the purification of large biomolecules such as polyethylene

    E-Print Network [OSTI]

    Lebendiker, Mario

    such as polyethylene glycol (PEG)-modified proteins (i.e., PEGylated proteins) that are intended for use

  8. Effects of storage temperature and duration on release of antimony and bisphenol A from polyethylene terephthalate drinking water

    E-Print Network [OSTI]

    Ma, Lena

    polyethylene terephthalate drinking water bottles of China Ying-Ying Fan a , Jian-Lun Zheng a , Jing-Hua Ren Accepted 9 May 2014 Available online xxx Keywords: Polyethylene terephthalate Antimony Bisphenol A Release of antimony (Sb) and bisphenol A (BPA) from 16 brands of polyethylene terephthalate (PET) drinking water

  9. Deformation-Induced Color Changes in Mechanochromic Polyethylene Brent R. Crenshaw, Mark Burnworth, Devang Khariwala, Anne Hiltner,

    E-Print Network [OSTI]

    Mather, Patrick T.

    Deformation-Induced Color Changes in Mechanochromic Polyethylene Blends Brent R. Crenshaw, Mark and systematic investigation of mechanochromic, melt-processed blends between a series of polyethylenes (PE-density polyethylene (LLDPE) of moderately high density (0.94 g cm-3). In samples that were slowly cooled from the melt

  10. Effects of polyethylene mulch in a short-rotation, poplar plantation vary with weed-control strategies,

    E-Print Network [OSTI]

    Green, Scott

    Effects of polyethylene mulch in a short-rotation, poplar plantation vary with weed polyethylene mulch (poly mulch) across a range of site conditions, weed-control treatments and genotypes rights reserved. Keywords: Polyethylene mulch; Woody crops; Weed control Forest Ecology and Management

  11. Crystallization in the Thin and Ultrathin Films of Poly(ethylene-vinyl acetate) and Linear Low-Density Polyethylene

    E-Print Network [OSTI]

    -Density Polyethylene Y. Wang, S. Ge, M. Rafailovich,*, J. Sokolov, Y. Zou, H. Ade, J. Lu1 ning,§ A. Lustiger, and G(ethylene-vinyl acetate) and linear low-density polyethylene (LLDPE) films spun-cast from the polymer/toluene solutions spherulite to sheaflike ag- gregates in polyethylene thin films at a critical thickness of 400 nm. Scho

  12. Insight into the Molecular Arrangement of High-Density Polyethylene Polymer Chains in Blends of Polystyrene/High-

    E-Print Network [OSTI]

    Insight into the Molecular Arrangement of High-Density Polyethylene Polymer Chains in Blends of Polystyrene/High- Density Polyethylene from Differential Scanning Calorimetry and Raman Techniques JAYANT/high-density polyethylene (PS/HDPE) blends were synthe- sized by melt blending in a single screw extruder. Co

  13. Friction and wear behavior of ultra-high molecular weight polyethylene as a function of polymer crystallinity

    E-Print Network [OSTI]

    Lin, Zhiqun

    Friction and wear behavior of ultra-high molecular weight polyethylene as a function of polymer-grade ultra-high molecular weight polyethylene (UHMWPE) (GUR 1050 resin) were evaluated as a function replacements; Ultra-high molecular weight polyethylene (UHMWPE); Crystallinity; Friction; Wear 1. Introduction

  14. Thermal engine

    SciTech Connect (OSTI)

    Karnes, T.E.; Trupin, R.J.

    1984-01-03

    A thermal engine utilizing a strip of nitinol material or other thermally responsive shape memory effect material to drive a reciprocating output shaft, said strip of material forming a common wall between two different alternating temperature sources which thermally cycle the material.

  15. NO. REV. NO. APOLLO 12 PSE THERMAL

    E-Print Network [OSTI]

    Rathbun, Julie A.

    : . .'.) NO. REV. NO. ATM 887 APOLLO 12 PSE THERMAL ANOMALY FINAL REPORT PAGE I DATE 5 This ATM summarizes the results of the BxA study conducted to investigate the ALSEP Flight I PSE Thermal Anomaly) determine the most probable cause of the temperature related anomalies, (3) recommend possible thermal

  16. Polymer crystal-melt interfaces and nucleation in polyethylene

    E-Print Network [OSTI]

    Scott T. Milner

    2010-09-22

    Kinetic barriers cause polymers to crystallize incompletely, into nanoscale lamellae interleaved with amorphous regions. As a result, crystalline polymers are full of crystal-melt interfaces, which dominate their physical properties. The longstanding theoretical challenge to understand these interfaces has new relevance, because of accumulating evidence that polymer crystals often nucleate via a metastable, partially ordered "rotator" phase. To test this idea requires a theory of the bulk and interfacial free energies of the critical nucleus. We present a new approach to the crystal-melt interface, which represents the amorphous region as a grafted brush of loops in a self-consistent pressure field. We combine this theory with estimates of bulk free energy differences, to calculate nucleation barriers and rates via rotator versus crystal nuclei for polyethylene. We find rotator-phase nucleation is indeed favored throughout the temperature range where nucleation is observed. Our methods can be extended to other polymers.

  17. Measurement and Analysis of Fission Rates in a Spherical Mockup of Uranium and Polyethylene

    E-Print Network [OSTI]

    Tong-Hua, Zhu; Xin-Xin, Lu; Rong, Liu; Zi-Jie, Han; Li, Jiang; Mei, Wang

    2013-01-01

    Measurements of the reaction rate distribution were carried out using two kinds of Plate Micro Fission Chamber(PMFC). The first is a depleted uranium chamber and the second an enriched uranium chamber. The material in the depleted uranium chamber is strictly the same as the material in the uranium assembly. With the equation solution to conduct the isotope contribution correction, the fission rate of 238U and 235U were obtained from the fission rate of depleted uranium and enriched uranium. And then, the fission count of 238U and 235U in an individual uranium shell was obtained. In this work, MCNP5 and continuous energy cross sections ENDF/BV.0 were used for the analysis of fission rate distribution and fission count. The calculated results were compared with the experimental ones. The calculation of fission rate of DU and EU were found to agree with the measured ones within 10% except at the positions in polyethylene region and the two positions near the outer surface. Beacause the fission chamber was not co...

  18. Current Activities Assessing Butt Fusion Joint Integrity in High Density Polyethylene Piping

    SciTech Connect (OSTI)

    Crawford, Susan L.; Cinson, Anthony D.; Doctor, Steven R.; Denslow, Kayte M.

    2012-09-01

    The Pacific Northwest National Laboratory (PNNL) in Richland, Washington, conducted initial studies to evaluate the effectiveness of nondestructive examinations (NDE) coupled with mechanical testing for assessing butt fusion joint integrity in high density polyethylene (HDPE) pipe. The work provided insightful information to the United States Nuclear Regulatory Commission (NRC) on the effectiveness of volumetric inspection techniques for detecting lack of fusion (LOF) conditions in the fusion joints. HDPE has been installed on a limited basis in American Society of Mechanical Engineers (ASME) Class 3, buried piping systems at several operating U.S. nuclear power plants and has been proposed for use in new construction. A comparison was made between the results from ultrasonic and microwave nondestructive examinations and the results from mechanical destructive evaluations, specifically the high-speed tensile test and the side-bend test, for determining joint integrity. The data comparison revealed that none of the NDE techniques detected all of the lack-of-fusion conditions that were revealed by the destructive tests. Follow-on work has recently been initiated at PNNL to accurately characterize the NDE responses from machined flaws of varying size and location in PE 4710 materials as well as the LOF condition. This effort is directed at quantifying the ability of volumetric NDE techniques to detect flaws in relation to the critical flaw size associated with joint integrity. A status of these latest investigations is presented.

  19. Accepted for Publication in J. Rheology (May/June 2005 Issue) March 1, 2005 Measuring the Transient Extensional Rheology of Polyethylene Melts

    E-Print Network [OSTI]

    Extensional Rheology of Polyethylene Melts Using the SER Universal Testing Platform Martin Sentmanat Senkhar stress growth in a number of different molten polyethylene samples including a linear low density polyethylene (Dow Affinity PL 1880), a low density polyethylene (Lupolen 1840H) and an ultrahigh molecular

  20. The Theory of Thermal, Thermoelectric and Electrical Transport Properties of Graphene

    E-Print Network [OSTI]

    Ugarte, Vincent Ike

    2010-01-01

    In Boltzmann theory of transport the electrical conductivityThe Theory of Thermal, Thermoelectric and ElectricalThe Theory of Thermal, Thermoelectric and Electrical

  1. Thermal and non-thermal energies in solar flares

    E-Print Network [OSTI]

    Pascal Saint-Hilaire; Arnold O. Benz

    2005-03-03

    The energy of the thermal flare plasma and the kinetic energy of the non-thermal electrons in 14 hard X-ray peaks from 9 medium-sized solar flares have been determined from RHESSI observations. The emissions have been carefully separated in the spectrum. The turnover or cutoff in the low-energy distribution of electrons has been studied by simulation and fitting, yielding a reliable lower limit to the non-thermal energy. It remains the largest contribution to the error budget. Other effects, such as albedo, non-uniform target ionization, hot target, and cross-sections on the spectrum have been studied. The errors of the thermal energy are about equally as large. They are due to the estimate of the flare volume, the assumption of the filling factor, and energy losses. Within a flare, the non-thermal/thermal ratio increases with accumulation time, as expected from loss of thermal energy due to radiative cooling or heat conduction. Our analysis suggests that the thermal and non-thermal energies are of the same magnitude. This surprising result may be interpreted by an efficient conversion of non-thermal energy to hot flare plasma.

  2. Heat transmission between a profiled nanowire and a thermal bath

    SciTech Connect (OSTI)

    Blanc, Christophe; Heron, Jean-Savin; Fournier, Thierry; Bourgeois, Olivier

    2014-07-28

    Thermal transport through profiled and abrupt contacts between a nanowire and a reservoir has been investigated by thermal conductance measurements. It is demonstrated that above 1?K the transmission coefficients are identical between abrupt and profiled junctions. This shows that the thermal transport is principally governed by the nanowire itself rather than by the resistance of the thermal contact. These results are perfectly compatible with the previous theoretical models. The thermal conductance measured at sub-Kelvin temperatures is discussed in relation to the universal value of the quantum of thermal conductance.

  3. Electrically conductive composite material

    SciTech Connect (OSTI)

    Clough, Roger L. (Albuquerque, NM); Sylwester, Alan P. (Albuquerque, NM)

    1989-01-01

    An electrically conductive composite material is disclosed which comprises a conductive open-celled, low density, microcellular carbon foam filled with a non-conductive polymer or resin. The composite material is prepared in a two-step process consisting of first preparing the microcellular carbon foam from a carbonizable polymer or copolymer using a phase separation process, then filling the carbon foam with the desired non-conductive polymer or resin. The electrically conductive composites of the present invention has a uniform and consistant pattern of filler distribution, and as a result is superior over prior art materials when used in battery components, electrodes, and the like.

  4. Electrically conductive composite material

    DOE Patents [OSTI]

    Clough, R.L.; Sylwester, A.P.

    1988-06-20

    An electrically conductive composite material is disclosed which comprises a conductive open-celled, low density, microcellular carbon foam filled with a non-conductive polymer or resin. The composite material is prepared in a two-step process consisting of first preparing the microcellular carbon foam from a carbonizable polymer or copolymer using a phase separation process, then filling the carbon foam with the desired non-conductive polymer or resin. The electrically conductive composites of the present invention has a uniform and consistent pattern of filler distribution, and as a result is superior over prior art materials when used in battery components, electrodes, and the like. 2 figs.

  5. Electrically conductive composite material

    DOE Patents [OSTI]

    Clough, R.L.; Sylwester, A.P.

    1989-05-23

    An electrically conductive composite material is disclosed which comprises a conductive open-celled, low density, microcellular carbon foam filled with a non-conductive polymer or resin. The composite material is prepared in a two-step process consisting of first preparing the microcellular carbon foam from a carbonizable polymer or copolymer using a phase separation process, then filling the carbon foam with the desired non-conductive polymer or resin. The electrically conductive composites of the present invention has a uniform and consistent pattern of filler distribution, and as a result is superior over prior art materials when used in battery components, electrodes, and the like. 2 figs.

  6. Thermal insulated glazing unit

    DOE Patents [OSTI]

    Selkowitz, S.E.; Arasteh, D.K.; Hartmann, J.L.

    1988-04-05

    An improved insulated glazing unit is provided which can attain about R5 to about R10 thermal performance at the center of the glass while having dimensions about the same as those of a conventional double glazed insulated glazing unit. An outer glazing and inner glazing are sealed to a spacer to form a gas impermeable space. One or more rigid, non-structural glazings are attached to the inside of the spacer to divide the space between the inner and outer glazings to provide insulating gaps between glazings of from about 0.20 inches to about 0.40 inches. One or more glazing surfaces facing each thermal gap are coated with a low emissivity coating. Finally, the thermal gaps are filled with a low conductance gas such as krypton gas. 2 figs.

  7. Thermal insulated glazing unit

    DOE Patents [OSTI]

    Selkowitz, Stephen E. (Piedmont, CA); Arasteh, Dariush K. (Oakland, CA); Hartmann, John L. (Seattle, WA)

    1991-01-01

    An improved insulated glazing unit is provided which can attain about R5 to about R10 thermal performance at the center of the glass while having dimensions about the same as those of a conventional double glazed insulated glazing unit. An outer glazing and inner glazing are sealed to a spacer to form a gas impermeable space. One or more rigid, non-structural glazings are attached to the inside of the spacer to divide the space between the inner and outer glazings to provide insulating gaps between glazings of from about 0.20 inches to about 0.40 inches. One or more glazing surfaces facing each thermal gap are coated with a low emissivity coating. Finally, the thermal gaps are filled with a low conductance gas such as krypton gas.

  8. Selected Physical Characteristics of Polystyrene/High Density Polyethylene Composites Prepared from Virgin

    E-Print Network [OSTI]

    Virgin and Recycled Materials Jayant Joshi, Richard Lehman, Thomas Nosker Rutgers University School: Mixtures of polystyrene and high density polyethylene were injection molded from recycled and virgin polymers to generate cocontinuous structures. The mechanical properties of these blends were evaluated

  9. Plastic Deformation of Semicrystalline Polyethylene under Extension, Compression, and Shear Using Molecular Dynamics Simulation

    E-Print Network [OSTI]

    Kim, Jun Mo

    Plastic deformation of the stack of alternating crystal and amorphous layers typical of semicrystalline polyethylene is studied by molecular dynamics simulation. A previous investigation of the semicrystalline layered stack ...

  10. A method for using polyethylene passive samplers to measure polycyclic aromatic hydrocarbon chemical activity in sediments

    E-Print Network [OSTI]

    Fernandez, Loretta A. (Loretta Ana)

    2005-01-01

    In order to aid in the determination of the hazards posed by hydrophobic organic compounds (HOCs) in sediment beds, a method for the use of polyethylene (PE) sheets as passive sampling devices for measuring chemical ...

  11. Thermal Analysis of Novel Underfill Materials with Optimum Processing Characteristics

    E-Print Network [OSTI]

    Harmon, Julie P.

    - date the morphology of these composites. © 2005 Wiley Peri- odicals, Inc. J Appl Polym Sci 98: 1300 chip. Polymers are thermally insulating mate- rials; the thermal conductivity of a typical polymer the compos- ite thermal conductivity up to 32.5 W/m K at the maximum filler loading of 78 vol %. Polymer

  12. Thermally actuated thermionic switch

    DOE Patents [OSTI]

    Barrus, D.M.; Shires, C.D.

    1982-09-30

    A thermally actuated thermionic switch which responds to an increase of temperature by changing from a high impedance to a low impedance at a predictable temperature set point. The switch has a bistable operation mode switching only on temperature increases. The thermionic material may be a metal which is liquid at the desired operation temperature and held in matrix in a graphite block reservoir, and which changes state (ionizes, for example) so as to be electrically conductive at a desired temperature.

  13. Comparative investigations of surface instabilities ("sharkskin") of a linear and a long-chain branched polyethylene

    E-Print Network [OSTI]

    Teodor I. Burghelea; Hans J. Griess; Helmut Muenstedt

    2010-01-15

    An experimental study of the physical origin and the mechanisms of the sharkskin instability is presented. Extrusion flows through a slit die are studied for two materials: a linear low density polyethylene (LLDPE) and a low density polyethylene (LDPE). By combining laser-Doppler velocimetry (LDV) with rheological measurements in both uniaxial extension and shear, the distributions of tensile and shear stresses in extrusion flows are measured for both materials.

  14. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    Solar Thermal Collectors .is solar energy. Solar thermal collector arrays can be usedon integrating solar thermal collectors with desalination

  15. High conductance surge cable

    DOE Patents [OSTI]

    Murray, M.M.; Wilfong, D.H.; Lomax, R.E.

    1998-12-08

    An electrical cable for connecting transient voltage surge suppressors to electrical power panels. A strip of electrically conductive foil defines a longitudinal axis, with a length of an electrical conductor electrically attached to the metallic foil along the longitudinal axis. The strip of electrically conductive foil and the length of an electrical conductor are covered by an insulating material. For impedance matching purposes, triangular sections can be removed from the ends of the electrically conductive foil at the time of installation. 6 figs.

  16. High conductance surge cable

    DOE Patents [OSTI]

    Murray, Matthew M. (Espanola, NM); Wilfong, Dennis H. (Brooksville, FL); Lomax, Ralph E. (Santa Fe, NM)

    1998-01-01

    An electrical cable for connecting transient voltage surge suppressers to ectrical power panels. A strip of electrically conductive foil defines a longitudinal axis, with a length of an electrical conductor electrically attached to the metallic foil along the longitudinal axis. The strip of electrically conductive foil and the length of an electrical conductor are covered by an insulating material. For impedance matching purposes, triangular sections can be removed from the ends of the electrically conductive foil at the time of installation.

  17. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    and thermal energy storage in solar thermal applications,"aided or powered by solar thermal energy. A section is alsoexhaustive review of solar thermal energy systems has been

  18. Advanced Thermal Control

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

    thermal models power density cost lifetime Advanced Thermal Interface Materials Advanced Heat Transfer Technologies Air Cooling Thermal System Performance and Integration Thermal...

  19. Electrically conductive cellulose composite

    DOE Patents [OSTI]

    Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

    2010-05-04

    An electrically conductive cellulose composite includes a cellulose matrix and an electrically conductive carbonaceous material incorporated into the cellulose matrix. The electrical conductivity of the cellulose composite is at least 10 .mu.S/cm at 25.degree. C. The composite can be made by incorporating the electrically conductive carbonaceous material into a culture medium with a cellulose-producing organism, such as Gluconoacetobacter hansenii. The composites can be used to form electrodes, such as for use in membrane electrode assemblies for fuel cells.

  20. Molecular Dynamics Study of Stiffness in Polystyrene and Polyethylene

    E-Print Network [OSTI]

    Hamed Nazarpourfard; Mahdi Ahmadi Borji

    2015-04-26

    In this paper, we have studied polystyrene (PS) and polyethylene (PE) stiffness by 3-dimensional Langevin Molecular Dynamics simulation. Hard polymers have a very small bending, and thus, their end-to-end distance is more than soft polymers. Quantum dot lasers can be established as colloidal particles dipped in a liquid and grafted by polymer brushes to maintain the solution. Here by a study on molecular structures of PS and PE, we show that the principle reason lies on large phenyl groups around the backbone carbons of PS, rather than a PE with Hydrogen atoms. Our results show that the mean radius of PS random coil is more than PE which directly affects the quantum dot maintenance. In addition, effect of temperature increase on the mean radius is investigated. Our results show that by increasing temperature, both polymers tend to lengthen, and at all temperatures a more radius is predicted for PS rather than PE, but interestingly, with a difference in short and long chains. We show that stiffness enhancement is not the same at short and long polymers and the behavior is very different. Our results show a good consonance with both experimental and theoretical studies.

  1. A New Polyethylene Scattering Law Determined Using Inelastic Neutron Scattering

    SciTech Connect (OSTI)

    Lavelle, Christopher M [ORNL; Liu, C [Oak Ridge National Laboratory (ORNL); Stone, Matthew B [ORNL

    2013-01-01

    Monte Carlo neutron transport codes such as MCNP rely on accurate data for nuclear physics cross-sections to produce accurate results. At low energy, this takes the form of scattering laws based on the dynamic structure factor, S (Q, E). High density polyethylene (HDPE) is frequently employed as a neutron moderator at both high and low temperatures, however the only cross-sections available are for T =300 K, and the evaluation has not been updated in quite some time. In this paper we describe inelastic neutron scattering measurements on HDPE at 5 and 300 K which are used to improve the scattering law for HDPE. We describe the experimental methods, review some of the past HDPE scattering laws, and compare computations using these models to the measured S (Q, E). The total cross-section is compared to available data, and the treatment of the carbon secondary scatterer as a free gas is assessed. We also discuss the use of the measurement itself as a scattering law via the 1 phonon approximation. We show that a scattering law computed using a more detailed model for the Generalized Density of States (GDOS) compares more favorably to this experiment, suggesting that inelastic neutron scattering can play an important role in both the development and validation of new scattering laws for Monte Carlo work.

  2. Molecular Dynamics Study of Stiffness in Polystyrene and Polyethylene

    E-Print Network [OSTI]

    Mahdi Ahmadi Borji

    2015-10-10

    In this paper, we have studied polystyrene (PS) and polyethylene (PE) stiffness by 3-dimensional Langevin Molecular Dynamics simulation. Hard polymers have a very small bending, and thus, their end-to-end distance is more than soft polymers. Quantum dot lasers can be established as colloidal particles dipped in a liquid and grafted by polymer brushes to maintain the solution. Here by a study on molecular structures of PS and PE, we show that the principle reason lies on large phenyl groups around the backbone carbons of PS, rather than a PE with Hydrogen atoms. Our results show that the mean radius of PS random coil is more than PE which directly affects the quantum dot maintenance. In addition, effect of temperature increase on the mean radius is investigated. Our results show that by increasing temperature, both polymers tend to lengthen, and at all temperatures a more radius is predicted for PS rather than PE, but interestingly, with a difference in short and long chains. We show that stiffness enhancement is not the same at short and long polymers and the behavior is very different. Our results show a good consonance with both experimental and theoretical studies.

  3. Molecular Dynamics Study of Stiffness in Polystyrene and Polyethylene

    E-Print Network [OSTI]

    Nazarpourfard, Hamed

    2015-01-01

    In this paper, we have studied polystyrene (PS) and polyethylene (PE) stiffness by 3-dimensional Langevin Molecular Dynamics simulation. Hard polymers have a very small bending, and thus, their end-to-end distance is more than soft polymers. Quantum dot lasers can be established as colloidal particles dipped in a liquid and grafted by polymer brushes to maintain the solution. Here by a study on molecular structures of PS and PE, we show that the principle reason lies on large phenyl groups around the backbone carbons of PS, rather than a PE with Hydrogen atoms. Our results show that the mean radius of PS random coil is more than PE which directly affects the quantum dot maintenance. In addition, effect of temperature increase on the mean radius is investigated. Our results show that by increasing temperature, both polymers tend to lengthen, and at all temperatures a more radius is predicted for PS rather than PE, but interestingly, with a difference in short and long chains. We show that stiffness enhancement...

  4. Thermal to electricity conversion using thermal magnetic properties

    DOE Patents [OSTI]

    West, Phillip B [Idaho Falls, ID; Svoboda, John [Idaho Falls, ID

    2010-04-27

    A system for the generation of Electricity from Thermal Energy using the thermal magnetic properties of a Ferromagnetic, Electrically Conductive Material (FECM) in one or more Magnetic Fields. A FECM is exposed to one or more Magnetic Fields. Thermal Energy is applied to a portion of the FECM heating the FECM above its Curie Point. The FECM, now partially paramagnetic, moves under the force of the one or more Magnetic Fields. The movement of the FECM induces an electrical current through the FECM, generating Electricity.

  5. Electrically conductive diamond electrodes

    DOE Patents [OSTI]

    Swain, Greg (East Lansing, MI); Fischer, Anne (Arlington, VA),; Bennett, Jason (Lansing, MI); Lowe, Michael (Holt, MI)

    2009-05-19

    An electrically conductive diamond electrode and process for preparation thereof is described. The electrode comprises diamond particles coated with electrically conductive doped diamond preferably by chemical vapor deposition which are held together with a binder. The electrodes are useful for oxidation reduction in gas, such as hydrogen generation by electrolysis.

  6. Conductive fabric seal

    DOE Patents [OSTI]

    Livesay, Ronald Jason; Mason, Brandon William; Kuhn, Michael Joseph; Rowe, Nathan Carl

    2015-10-13

    Disclosed are several examples of a system and method for detecting if an article is being tampered with. Included is a covering made of a substrate that is coated with a layer of an electrically conductive material that forms an electrically conductive surface having an electrical resistance. The covering is configured to at least partially encapsulate the article such that the article cannot be tampered with, without modifying the electrical resistance of the electrically conductive surface of the covering. A sensing device is affixed to the electrically conductive surface of the covering and the sensing device monitors the condition of the covering by producing a signal that is indicative of the electrical resistance of the electrically conductive surface of the covering. A measured electrical resistance that differs from a nominal electrical resistance is indicative of a covering that is being tampered with and an alert is communicated to an observer.

  7. QUASI-STEADY CONFIGURATIONS OF CONDUCTIVE INTRACLUSTER MEDIA

    SciTech Connect (OSTI)

    Voit, G. M.

    2011-10-10

    The radial distributions of temperature, density, and gas entropy among cool-core clusters tend to be quite similar, suggesting that they have entered a quasi-steady state. If that state is regulated by a combination of thermal conduction and feedback from a central active galactic nucleus (AGN), then the characteristics of those radial profiles ought to contain information about the spatial distribution of AGN heat input and the relative importance of thermal conduction. This paper addresses those topics by deriving steady-state solutions for clusters in which radiative cooling, electron thermal conduction, and thermal feedback fueled by accretion are all present, with the aim of interpreting the configurations of cool-core clusters in terms of steady-state models. It finds that the core configurations of many cool-core clusters have entropy levels just below those of conductively balanced solutions in which magnetic fields have suppressed electron thermal conduction to {approx}1/3 of the full Spitzer value, suggesting that AGN feedback is triggered when conduction can no longer compensate for radiative cooling. And even when feedback is necessary to heat the central {approx}30 kpc, conduction may still be the most important heating mechanism within a cluster's central {approx}100 kpc.

  8. Electrical and Thermal Experimental Characterization and Modeling of Carbon Nanotube/Epoxy Composites 

    E-Print Network [OSTI]

    Gardea, Frank

    2012-10-19

    The present work investigates the effect of carbon nanotube (CNT) inclusions on the electrical and thermal conductivity of a thermoset epoxy resin. The characterization of electrical and thermal conductivity of CNT/epoxy composites is presented...

  9. Validation of thermal models for a prototypical MEMS thermal actuator.

    SciTech Connect (OSTI)

    Gallis, Michail A.; Torczynski, John Robert; Piekos, Edward Stanley; Serrano, Justin Raymond; Gorby, Allen D.; Phinney, Leslie Mary

    2008-09-01

    This report documents technical work performed to complete the ASC Level 2 Milestone 2841: validation of thermal models for a prototypical MEMS thermal actuator. This effort requires completion of the following task: the comparison between calculated and measured temperature profiles of a heated stationary microbeam in air. Such heated microbeams are prototypical structures in virtually all electrically driven microscale thermal actuators. This task is divided into four major subtasks. (1) Perform validation experiments on prototypical heated stationary microbeams in which material properties such as thermal conductivity and electrical resistivity are measured if not known and temperature profiles along the beams are measured as a function of electrical power and gas pressure. (2) Develop a noncontinuum gas-phase heat-transfer model for typical MEMS situations including effects such as temperature discontinuities at gas-solid interfaces across which heat is flowing, and incorporate this model into the ASC FEM heat-conduction code Calore to enable it to simulate these effects with good accuracy. (3) Develop a noncontinuum solid-phase heat transfer model for typical MEMS situations including an effective thermal conductivity that depends on device geometry and grain size, and incorporate this model into the FEM heat-conduction code Calore to enable it to simulate these effects with good accuracy. (4) Perform combined gas-solid heat-transfer simulations using Calore with these models for the experimentally investigated devices, and compare simulation and experimental temperature profiles to assess model accuracy. These subtasks have been completed successfully, thereby completing the milestone task. Model and experimental temperature profiles are found to be in reasonable agreement for all cases examined. Modest systematic differences appear to be related to uncertainties in the geometric dimensions of the test structures and in the thermal conductivity of the polycrystalline silicon test structures, as well as uncontrolled nonuniform changes in this quantity over time and during operation.

  10. Thermally Conductive Organic Dielectrics for Power Electronics and Electric Motors

    Broader source: Energy.gov [DOE]

    2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting

  11. THERMAL CONDUCTIVITY OF AQUEOUS NaCl SOLUTIONS

    Office of Scientific and Technical Information (OSTI)

    and uti1 ization of geothermal energy, petroleum recovery, desalination of sea water, and other energy systems involving water containing dissolved salts. brines contain a...

  12. Measurement of Thermal Diffusivity and Conductivity in Advanced Nanostructured Materials

    E-Print Network [OSTI]

    Teweldebrhan, Desalegne Bekuretsion

    2012-01-01

    magnetic recording and spintronic information processingmagnetic recording and spintronic information processing

  13. Effect of Nanoporosity on the Thermal Conductivity of Amorphous Carbon

    E-Print Network [OSTI]

    Fujii, Amanda

    2014-01-01

    Carbon aerogels . . . . . . . . . . . . . . .carbon thin films [6, 7, 15, 16] and carbon aerogels [10,law relations for carbon aerogels are also included [10,

  14. Evidence of ion mixing increasing the thermal boundary conductance...

    Office of Scientific and Technical Information (OSTI)

    (SNL-NM), Albuquerque, NM (United States) Sponsoring Org: USDOE National Nuclear Security Administration (NNSA) Country of Publication: United States Language: English...

  15. Thermal Conductivity of Cubic and Hexagonal Mesoporous Silica Thin Films

    E-Print Network [OSTI]

    Coquil, Thomas; Richman, Eric K.; Hutchinson, Neal J.; Tolbert, S H; Pilon, Laurent

    2009-01-01

    properties of silica aerogels between 1.4 and 330 k”,mesoporous thin ?lms are (i) aerogel and xerogel processes [processes [21,22]. Both aerogel and xerogel have very low

  16. T I ENHANCING THERMAL CONDUCTIVITY OF FLUIDS WITH NANOPARTICLES...

    Office of Scientific and Technical Information (OSTI)

    involves condensing nanophase powders from the vapor phase directly into a flowing low vapor pressure fluid. This technique was developed in Japan more than 10 years ago by Akoh...

  17. Measurement of thermal conductivity in proton irradiated silicon...

    Office of Scientific and Technical Information (OSTI)

    Unlike time domain thermoreflectance techniques that require application of a metal film, we perform our measurement on uncoated samples. This provides greater sensitivity to...

  18. High Thermal Conductivity Polymer Composites for Low-Cost Heat...

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

    Aerospace Heat recovery at moderate temperatures Benefits Lower cost Lightweight Corrosion resistance Multifunctionality Transition and...

  19. Thermal conductivity in harmonic lattices with random collisions

    E-Print Network [OSTI]

    Giada Basile; Cédric Bernardin; Milton Jara; Tomasz Komorowski; Stefano Olla

    2015-09-08

    We review recent rigorous mathematical results about the macroscopic behaviour of harmonic chains with the dynamics perturbed by a random exchange of velocities between nearest neighbor particles. The random exchange models the effects of nonlinearities of anharmonic chains and the resulting dynamics have similar macroscopic behaviour. In particular there is a superdiffusion of energy for unpinned acoustic chains. The corresponding evolution of the temperature profile is governed by a fractional heat equation. In non-acoustic chains we have normal diffusivity, even if momentum is conserved.

  20. The Thermal Conductivity of Rocks and Its Dependence Upon Temperature...

    Open Energy Info (EERE)

    unavailable. Authors F. Birch and H. Clark Published Journal American Journal of Science, 1940 DOI Not Provided Check for DOI availability: http:crossref.org Online...

  1. Bridging conduction and radiation : investigating thermal transport in nanoscale gaps

    E-Print Network [OSTI]

    Chiloyan, Vazrik

    2015-01-01

    Near field radiation transfer between objects separated by small gaps is a widely studied field in heat transfer and has become more important than ever. Many technologies such as heat assisted magnetic recording, aerogels, ...

  2. Measurement of Thermal Diffusivity and Conductivity in Advanced Nanostructured Materials

    E-Print Network [OSTI]

    Teweldebrhan, Desalegne Bekuretsion

    2012-01-01

    magnetic recording and spintronic information processingmagnetic recording and spintronic information processingparadigms, such as spintronics, call for drastic increase in

  3. Next-Generation LED Package Architectures Enabled by Thermally Conductive

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

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  4. Novel Transparent Phosphor Conversion Matrix with High Thermal Conductivity

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

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  5. THERMAL CONDUCTIVITY OF AQUEOUS NaCl SOLUTIONS

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding access toSmallTechnicalSheldon' THE TONGONAN GEOTHERMAL FIELD LEYTE

  6. Invited Review Article: Error and uncertainty in Raman thermal conductivity

    Office of Scientific and Technical Information (OSTI)

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  7. T I ENHANCING THERMAL CONDUCTIVITY OF FLUIDS WITH NANOPARTICLES*

    Office of Scientific and Technical Information (OSTI)

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  8. Continuous Processing of High Thermal Conductivity Fibers and Sheets

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

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  9. Inherent Errors Associated with Raman Based Thermal Conductivity

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfate Reducing(Journal Article)lasers(JournalatBaBarthe Gold-Ionic LiquidUltrathin(Journal Article)

  10. Measurement of thermal conductivity in proton irradiated silicon (Journal

    Office of Scientific and Technical Information (OSTI)

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  11. Measuring Thermal Conductivity with Raman:Capability Uncertainty and Strain

    Office of Scientific and Technical Information (OSTI)

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  12. Evidence of ion mixing increasing the thermal boundary conductance across

    Office of Scientific and Technical Information (OSTI)

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  13. Experimental and numerical study of the effective thermal conductivity of

    Office of Scientific and Technical Information (OSTI)

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  14. Heat diode effect and negative differential thermal conductance across

    Office of Scientific and Technical Information (OSTI)

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  15. Microstructure changes and thermal conductivity reduction in UO2 following

    Office of Scientific and Technical Information (OSTI)

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  16. Strain Effects in Raman Thermal Conductivity Measurements. (Conference) |

    Office of Scientific and Technical Information (OSTI)

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  17. Thermal Conductivity Measurements of Silicon Thin Films with Periodically

    Office of Scientific and Technical Information (OSTI)

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  18. Thermal Conductivity in Nanocrystalline Ceria Thin Films (Journal Article)

    Office of Scientific and Technical Information (OSTI)

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  19. Glass-like thermal conductivity in high efficiency thermoelectric materials

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

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  20. Los Alamos probes mysteries of uranium dioxide's thermal conductivity

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

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  1. Micro-machined thermo-conductivity detector

    DOE Patents [OSTI]

    Yu, Conrad (Antioch, CA)

    2003-01-01

    A micro-machined thermal conductivity detector for a portable gas chromatograph. The detector is highly sensitive and has fast response time to enable detection of the small size gas samples in a portable gas chromatograph which are in the order of nanoliters. The high sensitivity and fast response time are achieved through micro-machined devices composed of a nickel wire, for example, on a silicon nitride window formed in a silicon member and about a millimeter square in size. In addition to operating as a thermal conductivity detector, the silicon nitride window with a micro-machined wire therein of the device can be utilized for a fast response heater for PCR applications.

  2. Conduct of Operations

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

    2010-06-29

    This Order defines the requirements for establishing and implementing Conduct of Operations Programs at Department of Energy (DOE), including National Nuclear Security Administration (NNSA), facilities and projects. Cancels DOE O 5480.19. Admin Chg 1, 6-25-13

  3. Conduct of Operations

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

    2010-06-29

    This Order defines the requirements for establishing and implementing Conduct of Operations Programs at Department of Energy (DOE), including National Nuclear Security Administration (NNSA), facilities and projects. Admin Chg 2, dated 12-3-14, supersedes Admin Chg 1.

  4. Electrically conductive material

    DOE Patents [OSTI]

    Singh, J.P.; Bosak, A.L.; McPheeters, C.C.; Dees, D.W.

    1993-09-07

    An electrically conductive material is described for use in solid oxide fuel cells, electrochemical sensors for combustion exhaust, and various other applications possesses increased fracture toughness over available materials, while affording the same electrical conductivity. One embodiment of the sintered electrically conductive material consists essentially of cubic ZrO[sub 2] as a matrix and 6-19 wt. % monoclinic ZrO[sub 2] formed from particles having an average size equal to or greater than about 0.23 microns. Another embodiment of the electrically conductive material consists essentially at cubic ZrO[sub 2] as a matrix and 10-30 wt. % partially stabilized zirconia (PSZ) formed from particles having an average size of approximately 3 microns. 8 figures.

  5. Electrically conductive material

    DOE Patents [OSTI]

    Singh, Jitendra P. (Bollingbrook, IL); Bosak, Andrea L. (Burnam, IL); McPheeters, Charles C. (Woodridge, IL); Dees, Dennis W. (Woodridge, IL)

    1993-01-01

    An electrically conductive material for use in solid oxide fuel cells, electrochemical sensors for combustion exhaust, and various other applications possesses increased fracture toughness over available materials, while affording the same electrical conductivity. One embodiment of the sintered electrically conductive material consists essentially of cubic ZrO.sub.2 as a matrix and 6-19 wt. % monoclinic ZrO.sub.2 formed from particles having an average size equal to or greater than about 0.23 microns. Another embodiment of the electrically conductive material consists essentially at cubic ZrO.sub.2 as a matrix and 10-30 wt. % partially stabilized zirconia (PSZ) formed from particles having an average size of approximately 3 microns.

  6. Novel Transparent Phosphor Conversion Matrix with High Thermal...

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

    Transparent Phosphor Conversion Matrix with High Thermal Conductivity for Next-Generation Phosphor-Converted LED-based Solid State Lighting Novel Transparent Phosphor Conversion...

  7. Radiative conductivity in the Earth's lower mantle Alexander F. Goncharov1

    E-Print Network [OSTI]

    Jacobsen, Steven D.

    . The lower mantle extends from the 660-km seismic discontinuity to the core­mantle boundary at 2,900 km depth,10 . Thermal conductivity in metals is dominated by electron transport, whereas heat conduction in insulators

  8. Thermoelectric Conductivities at Finite Magnetic Field and the Nernst Effect

    E-Print Network [OSTI]

    Kim, Keun-Young; Seo, Yunseok; Sin, Sang-Jin

    2015-01-01

    We study electric, thermoelectric, and thermal conductivities of a strongly correlated system in the presence of magnetic field by gauge/gravity duality. We consider a general class of Einstein-Maxwell-Dilaton theory with axion fields imposing momentum relaxation. Analytic general formulas for DC conductivities and the Nernst signal are derived in terms of the black hole horizon data. For an explicit model study we analyse in detail the Dyonic black hole modified by momentum relaxation effect. In this model, the Nernst signal shows a typical vortex-liquid effect when momentum relaxation effect is comparable to chemical potential. We compute all AC electric, thermal, and thermal conductivities by numerical analysis and confirms that their zero frequency limits precisely reproduce our analytic formulas, which is a non-trivial consistency check of our methods. We discuss the momentum relaxation effect on conductivities including cyclotron frequencies.

  9. CX-008993: Categorical Exclusion Determination | Department of...

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

    CX-008993: Categorical Exclusion Determination "Continuous Processing of High Thermal Conductivity Polyethylene Fibers and Sheets CX(s) Applied: A9, B3.6 Date: 0822...

  10. Thermal Effects of Moisture in Rigid Insulation Board 

    E-Print Network [OSTI]

    Crow, G. W.

    1992-01-01

    The impact of moisture in rigid roof insulation upon energy consumption is often assumed to be a simple function of the conductance. This paper will show that there are complex interactions between conductance, thermal mass, and climate. The energy...

  11. Thermal properties of organic and inorganic aerogels

    SciTech Connect (OSTI)

    Hrubesh, L.W.; Pekala, R.W. (Chemistry and Material Science Department, Lawrence Livermore National Laboratory, Livermore, California 94551-9900 (United States))

    1994-03-01

    Aerogels are open-cell foams that have already been shown to be among the best thermal insulating solid materials known. This paper examines the three major contributions to thermal transport through porous materials; solid, gaseous, and radiative, to identify how to reduce the thermal conductivity of air-filled aerogels. We find that significant improvements in the thermal insulation property of aerogels are possible by; (i) employing materials with a low intrinsic solid conductivity, (ii) reducing the average pore size within aerogels, and (iii) affecting an increase of the infrared extinction in aerogels. Theoretically, polystyrene is the best of the organic materials and zirconia is the best inorganic material to use for the lowest achievable conductivity. Significant reduction of the thermal conductivity for all aerogel varieties is predicted with only a modest decrease of the average pore size. This might be achieved by modifying the sol-gel chemistry leading to aerogels. For example, a thermal resistance value of [ital R]=20 per inch would be possible for an air-filled resorcinol-formaldehyde aerogel at a density of 156 kg/m[sup 3], if the average pore size was less than 35 nm. An equation is included which facilitates the calculation of the optimum density for the minimum total thermal conductivity, for all varieties of aerogels.

  12. Effect of nano-fibers on the stress-strain behavior of semi-crystalline poly(ethylene terephthalate) at different strain rates

    E-Print Network [OSTI]

    Cohen, Ellann

    2008-01-01

    Uniaxial compression tests were performed on amorphous poly(ethylene terephthalate) (PET), amorphous poly(ethylene terephthalate)- glycol (PETG), semi-crystalline PET, and semicrystalline PET with various amounts of ...

  13. A Neutron Reflectivity Study of Polymer-Modified Phospholipid Monolayers at the Solid-Solution Interface: Polyethylene Glycol-Lipids on

    E-Print Network [OSTI]

    Wong, Joyce

    -Solution Interface: Polyethylene Glycol-Lipids on Silane-Modified Substrates T. L. Kuhl,# J. Majewski,* J. Y. Wong amounts of DSPE-PEG (DSPE with polyethylene glycol covalently grafted to its headgroup). Mixed lipid

  14. Comparison between Protein-Polyethylene Glycol (PEG) Interactions and the Effect of PEG on Protein-Protein Interactions Using the Liquid-Liquid Phase Transition

    E-Print Network [OSTI]

    Benedek, George B.

    Comparison between Protein-Polyethylene Glycol (PEG) Interactions and the Effect of PEG on Protein transitions is the required presence of additives such as polyethylene glycol (PEG). To investigate

  15. Self-Assembly and Chain-Folding in Hybrid Coil-Coil-Cube Triblock Oligomers of Polyethylene-b-Poly(ethylene

    E-Print Network [OSTI]

    Mather, Patrick T.

    Self-Assembly and Chain-Folding in Hybrid Coil-Coil-Cube Triblock Oligomers of Polyethylene-defined oligomeric polyethylene-block-poly(ethylene oxide)- block-polyhedral oligomeric silsesquioxane (PE

  16. 350 Biophysical Journal Volume 84 January 2003 350355 Osmotic Properties of Poly(Ethylene Glycols): Quantitative Features

    E-Print Network [OSTI]

    Podgornik, Rudolf

    350 Biophysical Journal Volume 84 January 2003 350­355 Osmotic Properties of Poly(Ethylene Glycols the intermembrane distance versus applied osmotic stress data of Kenworthy et al. for poly(ethylene glycol, in a bulk solution of equivalent monomer density, the polymer osmotic pressure is independent of polymer

  17. Rod Lakes, University of Wisconsin, 1 Brandel, B. and Lakes, R. S., "Negative Poisson's ratio polyethylene foams",

    E-Print Network [OSTI]

    Lakes, Roderic

    ] by first saturating the polymer sample with a non-reactive gas, typically CO2 or N2, in a high pressure polyethylene foams", adapted from J. Materials Science, 36, 5885-5893, July (2001). Abstract Various polyethylene foams were subjected to thermo-mechanical processing with the aim of transforming them into re

  18. Capillary Break Beneath a Slab: Polyethylene Sheeting over Aggregate; Southwestern Pennsylvania (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-07-01

    This document provides content for three areas of the Building America Solution Center. First, "Insulating Closed Crawlspace Walls and Band Joist Area" describes how to install rigid foam insulation on the interior perimeter walls and band joist area in closed crawlspace foundations of homes. Second, "Removing Construction Debris from Flexible Ducts" describes how to clean flexible ducts after construction or major renovation of a home to remove debris resulting from building materials, particularly airborne dust and particulates. Third, images, CAD drawings, and a case study illustrate right and wrong ways to apply polyethylene sheeting over aggregate. Similarly, a CAD drawing is included that illustrates the use of a concrete slab over polyethylene.

  19. Lithium ion conducting electrolytes

    DOE Patents [OSTI]

    Angell, C.A.; Liu, C.

    1996-04-09

    A liquid, predominantly lithium-conducting, ionic electrolyte is described having exceptionally high conductivity at temperatures of 100 C or lower, including room temperature, and comprising the lithium salts selected from the group consisting of the thiocyanate, iodide, bromide, chloride, perchlorate, acetate, tetrafluoroborate, perfluoromethane sulfonate, perfluoromethane sulfonamide, tetrahaloaluminate, and heptahaloaluminate salts of lithium, with or without a magnesium-salt selected from the group consisting of the perchlorate and acetate salts of magnesium. Certain of the latter embodiments may also contain molecular additives from the group of acetonitrile (CH{sub 3}CN), succinnonitrile (CH{sub 2}CN){sub 2}, and tetraglyme (CH{sub 3}--O--CH{sub 2}--CH{sub 2}--O--){sub 2} (or like solvents) solvated to a Mg{sup +2} cation to lower the freezing point of the electrolyte below room temperature. Other particularly useful embodiments contain up to about 40, but preferably not more than about 25, mol percent of a long chain polyether polymer dissolved in the lithium salts to provide an elastic or rubbery solid electrolyte of high ambient temperature conductivity and exceptional 100 C conductivity. Another embodiment contains up to about but not more than 10 mol percent of a molecular solvent such as acetone. 2 figs.

  20. Lithium ion conducting electrolytes

    DOE Patents [OSTI]

    Angell, C. Austen (Tempe, AZ); Liu, Changle (Tempe, AZ)

    1996-01-01

    A liquid, predominantly lithium-conducting, ionic electrolyte having exceptionally high conductivity at temperatures of 100.degree. C. or lower, including room temperature, and comprising the lithium salts selected from the group consisting of the thiocyanate, iodide, bromide, chloride, perchlorate, acetate, tetrafluoroborate, perfluoromethane sulfonate, perfluoromethane sulfonamide, tetrahaloaluminate, and heptahaloaluminate salts of lithium, with or without a magnesium-salt selected from the group consisting of the perchlorate and acetate salts of magnesium. Certain of the latter embodiments may also contain molecular additives from the group of acetonitrile (CH.sub.3 CN) succinnonitrile (CH.sub.2 CN).sub.2, and tetraglyme (CH.sub.3 --O--CH.sub.2 --CH.sub.2 --O--).sub.2 (or like solvents) solvated to a Mg.sup.+2 cation to lower the freezing point of the electrolyte below room temperature. Other particularly useful embodiments contain up to about 40, but preferably not more than about 25, mol percent of a long chain polyether polymer dissolved in the lithium salts to provide an elastic or rubbery solid electrolyte of high ambient temperature conductivity and exceptional 100.degree. C. conductivity. Another embodiment contains up to about but not more than 10 mol percent of a molecular solvent such as acetone.

  1. Conduct of Operations

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

    2010-06-29

    This Order defines the requirements for establishing and implementing Conduct of Operations Programs at Department of Energy (DOE), including National Nuclear Security Administration (NNSA), facilities and projects. Cancels DOE O 5480.19. Admin Chg 1, dated 6-25-13, cancels DOE O 422.1. Certified 12-3-14.

  2. Lithium ion conducting electrolytes

    DOE Patents [OSTI]

    Angell, Charles Austen (Mesa, AZ); Liu, Changle (Midland, MI); Xu, Kang (Montgomery Village, MD); Skotheim, Terje A. (Tucson, AZ)

    1999-01-01

    The present invention relates generally to highly conductive alkali-metal ion non-crystalline electrolyte systems, and more particularly to novel and unique molten (liquid), rubbery, and solid electrolyte systems which are especially well suited for use with high current density electrolytic cells such as primary and secondary batteries.

  3. AQUIFER THERMAL ENERGY STORAGE

    E-Print Network [OSTI]

    Tsang, C.-F.

    2011-01-01

    varying solar energy inputs and thermal or power demands. Itusing aquifers for thermal energy storage. Problems outlinedmatical Modeling of Thermal Energy Storage in Aquifers,"

  4. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    of solar collectors and thermal energy storage in solaraided or powered by solar thermal energy. A section is alsobesides MVC require thermal energy as their primary energy

  5. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    15] O. A. Hamed, "THERMAL PERFORMANCE OF MULTISTAGE FLASHdesa4.aspx. [18] Encon, "Thermal Evaporators," June 2013. [http://www.evaporator.com/thermal-evaporator. [19] Y. Tian

  6. AQUIFER THERMAL ENERGY STORAGE

    E-Print Network [OSTI]

    Tsang, C.-F.

    2011-01-01

    of such an aquifer thermal storage system were studied andusing aquifers for thermal energy storage. Problems outlinedmatical Modeling of Thermal Energy Storage in Aquifers,"

  7. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    This requires no thermal storage tanks, but can have athe need for large thermal storage equipment, the evaporatorinclude analysis of thermal storage. A way of keeping the

  8. AQUIFER THERMAL ENERGY STORAGE

    E-Print Network [OSTI]

    Tsang, C.-F.

    2011-01-01

    aquifers for thermal energy storage. Problems outlined aboveModeling of Thermal Energy Storage in Aquifers," Proceed-ings of Aquifer Thermal Energy Storage Workshop, Lawrence

  9. MD Simulation Study of the Influence of Branch Content on Relaxation and Crystallization of Branched Polyethylene Chains with Uniform Branch Distribution

    E-Print Network [OSTI]

    Hussein, Ibnelwaleed A.

    of Branched Polyethylene Chains with Uniform Branch Distribution I. A. HUSSEIN, B. F. ABU-SHARKH* Department-density polyethylene (LLDPE) chains with different levels of branch content (BC), ranging from 10 to 80 branches/1000 C words: MD simulation, Polyethylene, branch content, chain conformation, radius of gyration

  10. Super ionic conductive glass

    DOE Patents [OSTI]

    Susman, Sherman (Park Forest, IL); Volin, Kenneth J. (Fort Collins, CO)

    1984-01-01

    An ionically conducting glass for use as a solid electrolyte in a power or secondary cell containing an alkali metal-containing anode and a cathode separated by an alkali metal ion conducting glass having an ionic transference number of unity and the general formula: A.sub.1+x D.sub.2-x/3 Si.sub.x P.sub.3-x O.sub.12-2x/3, wherein A is a network modifier for the glass and is an alkali metal of the anode, D is an intermediate for the glass and is selected from the class consisting of Zr, Ti, Ge, Al, Sb, Be, and Zn and X is in the range of from 2.25 to 3.0. Of the alkali metals, Na and Li are preferred and of the intermediate, Zr, Ti and Ge are preferred.

  11. Electrically conductive alternating copolymers

    DOE Patents [OSTI]

    Aldissi, M.; Jorgensen, B.S.

    1987-08-31

    Polymers which are soluble in common organic solvents and are electrically conductive, but which also may be synthesized in such a manner that they become nonconductive. Negative ions from the electrolyte used in the electrochemical synthesis of a polymer are incorporated into the polymer during the synthesis and serve as a dopant. A further electrochemical step may be utilized to cause the polymer to be conductive. The monomer repeat unit is comprised of two rings, a pyrrole molecule joined to a thienyl group, or a furyl group, or a phenyl group. The individual groups of the polymers are arranged in an alternating manner. For example, the backbone arrangement of poly(furylpyrrole) is -furan-pyrrole-furan-pyrrole- furan-pyrrole. An alkyl group or phenyl group may be substituted for either or both of the hydrogen atoms of the pyrrole ring.

  12. Oxygen ion conducting materials

    DOE Patents [OSTI]

    Carter, J. David; Wang, Xiaoping; Vaughey, John; Krumpelt, Michael

    2004-11-23

    An oxygen ion conducting ceramic oxide that has applications in industry including fuel cells, oxygen pumps, oxygen sensors, and separation membranes. The material is based on the idea that substituting a dopant into the host perovskite lattice of (La,Sr)MnO.sub.3 that prefers a coordination number lower than 6 will induce oxygen ion vacancies to form in the lattice. Because the oxygen ion conductivity of (La,Sr)MnO.sub.3 is low over a very large temperature range, the material exhibits a high overpotential when used. The inclusion of oxygen vacancies into the lattice by doping the material has been found to maintain the desirable properties of (La,Sr)MnO.sub.3, while significantly decreasing the experimentally observed overpotential.

  13. Oxygen ion conducting materials

    DOE Patents [OSTI]

    Vaughey, John (Elmhurst, IL); Krumpelt, Michael (Naperville, IL); Wang, Xiaoping (Downers Grove, IL); Carter, J. David (Bolingbrook, IL)

    2003-01-01

    An oxygen ion conducting ceramic oxide that has applications in industry including fuel cells, oxygen pumps, oxygen sensors, and separation membranes. The material is based on the idea that substituting a dopant into the host perovskite lattice of (La,Sr)MnO.sub.3 that prefers a coordination number lower than 6 will induce oxygen ion vacancies to form in the lattice. Because the oxygen ion conductivity of (La,Sr)MnO.sub.3 is low over a very large temperature range, the material exhibits a high overpotential when used. The inclusion of oxygen vacancies into the lattice by doping the material has been found to maintain the desirable properties of (La,Sr)MnO.sub.3, while significantly decreasing the experimentally observed overpotential.

  14. Oxygen ion conducting materials

    DOE Patents [OSTI]

    Vaughey, John; Krumpelt, Michael; Wang, Xiaoping; Carter, J. David

    2005-07-12

    An oxygen ion conducting ceramic oxide that has applications in industry including fuel cells, oxygen pumps, oxygen sensors, and separation membranes. The material is based on the idea that substituting a dopant into the host perovskite lattice of (La,Sr)MnO.sub.3 that prefers a coordination number lower than 6 will induce oxygen ion vacancies to form in the lattice. Because the oxygen ion conductivity of (La,Sr)MnO.sub.3 is low over a very large temperature range, the material exhibits a high overpotential when used. The inclusion of oxygen vacancies into the lattice by doping the material has been found to maintain the desirable properties of (La,Sr)MnO.sub.3, while significantly decreasing the experimentally observed overpotential.

  15. High conductivity composite metal

    DOE Patents [OSTI]

    Zhou, R.; Smith, J.L.; Embury, J.D.

    1998-01-06

    Electrical conductors and methods of producing them are disclosed, where the conductors possess both high strength and high conductivity. Conductors are comprised of carbon steel and a material chosen from a group consisting of copper, nickel, silver, and gold. Diffusion barriers are placed between these two materials. The components of a conductor are assembled and then the assembly is subjected to heat treating and mechanical deformation steps. 10 figs.

  16. Coextruded Polyethylene and Wood-Flour Composite: Effect of Shell Thickness, Wood Loading, and Core

    E-Print Network [OSTI]

    Appl Polym Sci 118: 3594­3601, 2010 Key words: coextrusion; mechanical properties; recycling recycled polyethylene and wood-flour composites with core­shell structure were manufactured using a pilot to use recycled, low quality plastic-fiber blends in the core layer. VC 2010 Wiley Periodicals, Inc. J

  17. Semi-Crystalline Polymers Semi-crystalline polymers, such as polyethylene and polypropylene are common

    E-Print Network [OSTI]

    Beaucage, Gregory

    Semi-Crystalline Polymers Semi-crystalline polymers, such as polyethylene and polypropylene of 5 to 50 nm. Such highly asymmetric, plate like structures tend to stack when sufficient crystalline concentration, or degree of crystallinity, exists. Tie chains between crystallites serve to enhance stacking

  18. Single-site polymerization catalysts: branched polyethylene and syndiotactic poly(alpha-olefins) 

    E-Print Network [OSTI]

    Schwerdtfeger, Eric Dean

    2009-05-15

    (Oct-CGC) were found to melt at higher temperatures (55.9 and 43.1 °C, respectively) than any previously reported samples. The MAO-activated Oct-CGC was also used to produce polyethylene samples at a variety of polymerization temperatures and pressures...

  19. Multiscale thermal transport.

    SciTech Connect (OSTI)

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

    2004-02-01

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

  20. Thermal and Kinematic Evolution of the Eastern Cordillera Fold and

    E-Print Network [OSTI]

    Toro, Jaime

    Thermal and Kinematic Evolution of the Eastern Cordillera Fold and Thrust Belt, Colombia Jaime Toro and then calculated the conductive thermal state of key steps of the kinematic history using ThrustpackR 4.0. The models were constrained by well, seismic, apatite fission-track, and thermal-maturity data. The main