National Library of Energy BETA

Sample records for thermal conductivity measurements

  1. 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.

  2. 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.

  3. 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.

  4. 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...

  5. 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.

  6. 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 ...

  7. 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...

  8. 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.

  9. 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.

  10. 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.

  11. 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...

  12. 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}.

  13. 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...

  14. 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...

  15. 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...

  16. 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.

  17. 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.

  18. Thermal Transport in Nanoporous Materials for Energy Applications

    E-Print Network [OSTI]

    Fang, Jin

    2012-01-01

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

  19. 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

  20. 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

  1. 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.

  2. 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

  3. 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...

  4. 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

  5. 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

  6. 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...

  7. 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

  8. 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

  9. 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...

  10. 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

  11. 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

  12. 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

  13. 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 ...

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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 ...

  2. 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...

  3. 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...

  4. 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

  5. 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

  6. 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.

  7. 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...

  8. 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 ...

  9. 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 ...

  10. Hydraulic Conductivity Measurements Barrow 2014

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

    Katie McKnight; Tim Kneafsey; Craig Ulrich; Jil Geller

    2015-02-22

    Six individual ice cores were collected from Barrow Environmental Observatory in Barrow, Alaska, in May of 2013 as part of the Next Generation Ecosystem Experiment (NGEE). Each core was drilled from a different location at varying depths. A few days after drilling, the cores were stored in coolers packed with dry ice and flown to Lawrence Berkeley National Laboratory (LBNL) in Berkeley, CA. 3-dimensional images of the cores were constructed using a medical X-ray computed tomography (CT) scanner at 120kV. Hydraulic conductivity samples were extracted from these cores at LBNL Richmond Field Station in Richmond, CA, in February 2014 by cutting 5 to 8 inch segments using a chop saw. Samples were packed individually and stored at freezing temperatures to minimize any changes in structure or loss of ice content prior to analysis. Hydraulic conductivity was determined through falling head tests using a permeameter [ELE International, Model #: K-770B]. After approximately 12 hours of thaw, initial falling head tests were performed. Two to four measurements were collected on each sample and collection stopped when the applied head load exceeded 25% change from the original load. Analyses were performed between 2 to 3 times for each sample. The final hydraulic conductivity calculations were computed using methodology of Das et al., 1985.

  11. Hydraulic Conductivity Measurements Barrow 2014

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

    Katie McKnight; Tim Kneafsey; Craig Ulrich; Jil Geller

    Six individual ice cores were collected from Barrow Environmental Observatory in Barrow, Alaska, in May of 2013 as part of the Next Generation Ecosystem Experiment (NGEE). Each core was drilled from a different location at varying depths. A few days after drilling, the cores were stored in coolers packed with dry ice and flown to Lawrence Berkeley National Laboratory (LBNL) in Berkeley, CA. 3-dimensional images of the cores were constructed using a medical X-ray computed tomography (CT) scanner at 120kV. Hydraulic conductivity samples were extracted from these cores at LBNL Richmond Field Station in Richmond, CA, in February 2014 by cutting 5 to 8 inch segments using a chop saw. Samples were packed individually and stored at freezing temperatures to minimize any changes in structure or loss of ice content prior to analysis. Hydraulic conductivity was determined through falling head tests using a permeameter [ELE International, Model #: K-770B]. After approximately 12 hours of thaw, initial falling head tests were performed. Two to four measurements were collected on each sample and collection stopped when the applied head load exceeded 25% change from the original load. Analyses were performed between 2 to 3 times for each sample. The final hydraulic conductivity calculations were computed using methodology of Das et al., 1985.

  12. 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 ...

  13. 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...

  14. 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:...

  15. 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...

  16. 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...

  17. 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.

  18. 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.

  19. 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

  20. 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...

  1. 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

  2. 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

  3. 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...

  4. 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...

  5. 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.

  6. 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

  7. 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. ...

  8. 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 ...

  9. 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 ...

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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....

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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.

  1. 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:

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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.

  12. 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.

  13. Weak measurement based on thermal noise effect

    E-Print Network [OSTI]

    Gang Li; Tao Wang; Shuang Xu; He-Shan Song

    2015-07-03

    Weak measurement with thermal state pointer can give rise to an amplification effect, and we give the generalization of the mechanism behind the amplification with pure Gaussion state pointer. We find that the maximal value of this effect can reach thermal fluctuations, and propose two schemes to implement room temperature weak measurement with thermal state pointer in optomechanical system.

  14. 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.

  15. 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

  16. 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.

  17. Measurements of the Thermal Neutron Scattering Kernel

    E-Print Network [OSTI]

    Danon, Yaron

    Measurements of the Thermal Neutron Scattering Kernel Li (Emily) Liu, Yaron Danon, Bjorn Becker and discussions Problems and Future study Questions #12;3 M. Mattes and J. Keinert, Thermal Neutron Scattering experimental data used was from 1973-1974! M. Mattes and J. Keinert, Thermal Neutron Scattering Data

  18. 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

  19. 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.

  20. 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

  1. 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.

  2. 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

  3. Thermal emission measurement and calibration

    E-Print Network [OSTI]

    Brown, Susannah (Susannah R.)

    2009-01-01

    This thesis details a measurement setup and experimental procedures for emittance measurements using a Fourier transform infrared spectrometer. We calibrate the FTIR measurement system using measurements of a blackbody ...

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. 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 ...

  12. 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.

  13. 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...

  14. 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.

  15. 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

  16. 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.

  17. 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 ...

  18. 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.

  19. 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...

  20. 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

  1. 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

  2. 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

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. 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...

  8. 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.

  9. 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

  10. Validation of satellite observed thermal emission with in-situ measurements over an urban surface

    E-Print Network [OSTI]

    Wunderle, Stefan

    Validation of satellite observed thermal emission with in-situ measurements over an urban surface: Meteorology applied to urban pollution problems). Besides very detailed field measurements of the structure and validations of thermal satellite imagery are conducted in rural, mostly homogeneous areas (Sobrino et al

  11. 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

  12. 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.

  13. 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.

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. 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 ...

  19. 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

  20. 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, ...

  1. 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 ...

  2. 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.

  3. 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.

  4. 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.

  5. Measurements of prompt radiation induced conductivity of Kapton.

    SciTech Connect (OSTI)

    Preston, Eric F.; Zarick, Thomas Andrew; Sheridan, Timothy J.; Hartman, E. Frederick; Stringer, Thomas Arthur

    2010-10-01

    We performed measurements of the prompt radiation induced conductivity in thin samples of Kapton (polyimide) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil samples were irradiated with a 0.5 {mu}s pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E10 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 6E-17 and 2E-16 mhos/m per rad/s, depending on the dose rate and the pulse width.

  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. 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

  9. 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

  10. 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

  11. 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...

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Measurements of prompt radiation induced conductivity in Teflon (PTFE).

    SciTech Connect (OSTI)

    Hartman, E. Frederick; Zarick, Thomas Andrew; Sheridan, Timothy J.; Preston, E.

    2013-05-01

    We performed measurements of the prompt radiation induced conductivity (RIC) in thin samples of Teflon (PTFE) at the Little Mountain Medusa LINAC facility in Ogden, UT. Three mil (76.2 microns) samples were irradiated with a 0.5 %CE%BCs pulse of 20 MeV electrons, yielding dose rates of 1E9 to 1E11 rad/s. We applied variable potentials up to 2 kV across the samples and measured the prompt conduction current. Details of the experimental apparatus and analysis are reported in this report on prompt RIC in Teflon.

  18. 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

  19. 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.

  20. 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.

  1. Measurements of prompt radiation induced conductivity of alumina and sapphire.

    SciTech Connect (OSTI)

    Hartman, E. Frederick; Zarick, Thomas Andrew; Sheridan, Timothy J.; Preston, Eric F.

    2011-04-01

    We performed measurements of the prompt radiation induced conductivity in thin samples of Alumina and Sapphire at the Little Mountain Medusa LINAC facility in Ogden, UT. Five mil thick samples were irradiated with pulses of 20 MeV electrons, yielding dose rates of 1E7 to 1E9 rad/s. We applied variable potentials up to 1 kV across the samples and measured the prompt conduction current. Analysis rendered prompt conductivity coefficients between 1E10 and 1E9 mho/m/(rad/s), depending on the dose rate and the pulse width for Alumina and 1E7 to 6E7 mho/m/(rad/s) for Sapphire.

  2. A measure of conductivity for lattice fermions at finite density

    E-Print Network [OSTI]

    J. L. Alonso; L. A. Fernandez; V. Martin-Mayor

    2000-03-31

    We study the linear response to an external electric field of a system of fermions in a lattice at zero temperature. This allows to measure numerically the Euclidean conductivity which turns out to be compatible with an analytical calculation for free fermions. The numerical method is generalizable to systems with dynamical interactions where no analytical approach is possible.

  3. 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.

  4. 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.

  5. Assembly for electrical conductivity measurements in the piston cylinder device

    DOE Patents [OSTI]

    Watson, Heather Christine (Dublin, CA); Roberts, Jeffrey James (Livermore, CA)

    2012-06-05

    An assembly apparatus for measurement of electrical conductivity or other properties of a sample in a piston cylinder device wherein pressure and heat are applied to the sample by the piston cylinder device. The assembly apparatus includes a body, a first electrode in the body, the first electrode operatively connected to the sample, a first electrical conductor connected to the first electrode, a washer constructed of a hard conducting material, the washer surrounding the first electrical conductor in the body, a second electrode in the body, the second electrode operatively connected to the sample, and a second electrical conductor connected to the second electrode.

  6. 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.

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. Measurement of thermal conductivity in proton irradiated silicon (Journal

    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(JournalspectroscopyReport) | SciTechelement method in the muon+jets

  12. Measuring Thermal Conductivity with Raman:Capability Uncertainty and Strain

    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(JournalspectroscopyReport) | SciTechelement method in theSciTech ConnectEffects.

  13. Strain Effects in Raman Thermal Conductivity Measurements. (Conference) |

    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 NaturalDukeWakefieldSulfateSciTechtail. (Conference)Feedback System inStatus of the MEIC ionConnectrandom

  14. Thermal Conductivity Measurements of Silicon Thin Films with Periodically

    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 NaturalDukeWakefieldSulfateSciTechtail.Theory of rare Kaon and Pion decays Citation Details In-Document

  15. 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

  16. 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

  17. 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

  18. Sandia Energy - Measurements of Thermal Stratification in a Homogenous...

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

    Measurements of Thermal Stratification in a Homogenous Charge Compression Ignition Engine Home Energy Transportation Energy CRF Facilities Partnership News News & Events Research &...

  19. Thermal Behavior of As-Recovered (Unneutralized) Aspigel (Pressure Measurements)

    SciTech Connect (OSTI)

    Scheele, Randall D.

    2010-07-02

    This brief report provides unreported pressures measured in accelerating rate calorimeter experiments performed to determine the thermal sensitivity of as-recovered and unneutralized Aspigel.

  20. A simplified model for thermal-wave cavity self-consistent measurement of thermal diffusivity

    SciTech Connect (OSTI)

    Shen, Jun, E-mail: jun.shen@nrc-cnrc.gc.ca; Zhou, Jianqin; Gu, Caikang [Energy, Mining and Environment Portfolio, National Research Council Canada, 4250 East Mall, Vancouver, British Columbia V6T 1W5 (Canada)] [Energy, Mining and Environment Portfolio, National Research Council Canada, 4250 East Mall, Vancouver, British Columbia V6T 1W5 (Canada); Neill, Stuart [Energy, Mining and Environment Portfolio, National Research Council Canada, 1200 Montreal Road, Building M-9, Ottawa, Ontario K1A 0R6 (Canada)] [Energy, Mining and Environment Portfolio, National Research Council Canada, 1200 Montreal Road, Building M-9, Ottawa, Ontario K1A 0R6 (Canada); Michaelian, Kirk H.; Fairbridge, Craig [CanmetENERGY, Natural Resources Canada, One Oil Drive Patch, Devon, Alberta T9G 1A8 (Canada)] [CanmetENERGY, Natural Resources Canada, One Oil Drive Patch, Devon, Alberta T9G 1A8 (Canada); Astrath, Nelson G. C.; Baesso, Mauro L. [Departamento de Física, Universidade Estadual de Maringá, Av. Colombo 5790, Maringá, Paraná 87020-900 (Brazil)] [Departamento de Física, Universidade Estadual de Maringá, Av. Colombo 5790, Maringá, Paraná 87020-900 (Brazil)

    2013-12-15

    A simplified theoretical model was developed for the thermal-wave cavity (TWC) technique in this study. This model takes thermal radiation into account and can be employed for absolute measurements of the thermal diffusivity of gas and liquid samples without any knowledge of geometrical and thermal parameters of the components of the TWC. Using this model and cavity-length scans, thermal diffusivities of air and distilled water were accurately and precisely measured as (2.191 ± 0.004) × 10{sup ?5} and (1.427 ± 0.009) × 10{sup ?7} m{sup 2}?s{sup ?1}, respectively, in very good agreement with accepted literature values.

  1. 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...

  2. 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.

  3. 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.

  4. Design and calibration of a test facility for MLI thermal performance measurements below 80K

    SciTech Connect (OSTI)

    Boroski, W.; Kunzelman, R.; Ruschman, M.; Schoo, C.

    1992-04-01

    The design geometry of the SSC dipole cryostat includes active thermal radiation shields operating at 80K and 20K respectively. Extensive measurements conducted in a Heat Leak Test Facility (HLTF) have been used to evaluate the thermal performance of candidate multilayer insulation (MLI) systems for the 80K thermal shield, with the present system design based upon those measurement results. With the 80K MLI geometry established, efforts have focused on measuring the performance of MLI systems near 20K. A redesign of the HLTF has produced a measurement facility capable of conducting measurements with the warm boundary fixed at 80K and the cold boundary variable from 10K to 50K. Removing the 80K shield permits measurements with a warm boundary at 300K. The 80K boundary consists of a copper shield thermally anchored to a liquid nitrogen reservoir. The cold boundary consists of a copper anchor plate whose temperature is varied through boil-off gas from a 500 liter helium supply dewar. A transfer line heat exchanger supplies the boil-off gas to the anchor plate at a constant and controlled rate. The gas, which serves as cooling gas, is routed through a copper cooling tube soldered into the anchor plate. Varying the cooling gas flow rate varies the amount of refrigeration supplied to the anchor plate, thereby determining the plate temperature. A resistance heater installed on the anchor plate is regulated by a cryogenic temperature controller to provide final temperature control. Heat leak values are measured using a heatmeter which senses heat flow as a temperature gradient across a fixed thermal impedance. Since the thermal conductivity of the thermal impedance changes with temperature, the heatmeter is calibrated at key cold boundary temperatures. Thus, the system is capable of obtaining measurement data under a variety of system conditions. 7 refs.

  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. 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.

  10. 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

  11. 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.

  12. 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.

  13. Method for measuring thermal properties using a long-wavelength infrared thermal image

    DOE Patents [OSTI]

    Walker, Charles L. (Albuquerque, NM); Costin, Laurence S. (Albuquerque, NM); Smith, Jody L. (Albuquerque, NM); Moya, Mary M. (Albuquerque, NM); Mercier, Jeffrey A. (Albuquerque, NM)

    2007-01-30

    A method for estimating the thermal properties of surface materials using long-wavelength thermal imagery by exploiting the differential heating histories of ground points in the vicinity of shadows. The use of differential heating histories of different ground points of the same surface material allows the use of a single image acquisition step to provide the necessary variation in measured parameters for calculation of the thermal properties of surface materials.

  14. 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.

  15. 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

  16. Thermal properties measurements on rocksalt samples from the site of the proposed Waste Isolation Pilot Plant

    SciTech Connect (OSTI)

    Sweet, J. N.; McCreight, J. E.

    1980-05-13

    Thermal conductivity, thermal expansion, and specific heat measurements have been made on a number of specimens. The specific heat measurements were made by differential scanning calorimetry and the results showed that the specific heats of both clean rocksalt samples and of dirty samples with less than or equal to 7% insoluble impurities were essentially identical to the published specific heat for pure NaCl. In the thermal expansion measurements, two distinct groups of samples were identified. The first group had average expansion coefficients in the temperature range 300 to 700/sup 0/K close to that reported for pure NaCl. All the samples in this group were composed predominantly of halite, with only small amounts of other minerals or materials present. A second group of samples had expansion coefficients only approx. 0.3 to 0.5 that of NaCl. The samples in this group were composed largely of polyhalite, anhydrite, or siltstone. The measurements first reported by Acton on the thermal conductivity of samples taken from a borehole at the site of the proposed nuclear waste isolation pilot plant (WIPP) near Carlsbad, NM, have been extended to include additional samples and higher temperature measurements. This is not believed to be the result of the onset of radiative thermal transport because the deviations are negative as well as positive. Infrared transmission measurements on rocksalt samples from the proposed WIPP site show no transmission in the 3 to 10 ..mu..m wavelength range for samples > 5 cm thick. Use of the estimated infrared absorption coefficient leads to the conclusion that there is little radiative heat transport for T < 800/sup 0/K. All samples were dense with little or no porosity evident. On the basis of these experiments, it is concluded that the thermal conductivity of materials found at the site can be predicted to an accuracy +- 30% from knowledge of the composition and grain size of these materials.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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 (

  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

    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

  3. 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

  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 arePCMs for thermal energy storage in solar driven residentialfluid and thermal energy storage medium in the solar heat

  5. Ultrahigh-resolution pyroelectric thermal-wave technique for the measurement of thermal diffusivity of low-concentration

    E-Print Network [OSTI]

    Mandelis, Andreas

    Ultrahigh-resolution pyroelectric thermal-wave technique for the measurement of thermal diffusivity Thermal diffusivities of water-methanol and water-ethanol mixtures were measured using a thermal in real-time water pollution monitoring. © 2005 American Institute of Physics. DOI: 10.1063/1.2074627 I

  6. 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.

  7. 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 ...

  8. 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.

  9. 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.

  10. 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

  11. 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...

  12. 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

  13. 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...

  14. Camera-based reflectivity measurement for solar thermal applications

    E-Print Network [OSTI]

    Camera-based reflectivity measurement for solar thermal applications John D. Pye1 , Clifford K. Ho2 2 6125 8778, john.pye@anu.edu.au. 2 Sandia National Laboratories, Albuquerque, New Mexico, USA. ckho of the solar-weighted reflectivity of the receiver component in CSP systems. Such reflectivity measurement

  15. Measurements of thermal photons in heavy ion collisions with PHENIX

    E-Print Network [OSTI]

    Torsten Dahms; for the PHENIX Collaboration

    2008-04-29

    Thermal photons are thought to be the ideal probe to measure the temperature of the quark-gluon plasma created in heavy ion collisions. PHENIX has measured direct photons with p_T < 5 GeV/c via their internal conversions into e+e- pairs in Au+Au collisions at sqrt(s_NN) = 200 GeV and has now provided a baseline measurement from p+p data.

  16. SSC 50 mm dipole magnet cryostat thermal measurement results

    SciTech Connect (OSTI)

    Boroski, W.N.; Nicol, T.H.; Ruschman, M.K.; Schoo, C.J.

    1993-05-01

    A prototype Superconducting Super Collider (SSC) 50 mm dipole magnet cryostat, DCA323, was instrumented at Fermilab and delivered to the SSC Laboratory for installation into the accelerator systems string test facility. In series with other magnets, the instrumented cryostat will be used to quantify and verify cryostat thermal performance with respect to design requirements. Prior to leaving Fermilab, DCA323 was subjected to magnetic testing at the Magnet Test Facility (MTF). This presented an opportunity to obtain preliminary thermal performance data under simulated operating conditions. It should be noted that measurements of overall cryostat thermal performance were not possible during the MTF measurements as the magnet test stands are designed for magnetic rather than thermal testing. They are not designed to limit heat inleak to the ends of the cryostat, which has been shown to have a significant effect on overall measured thermal performance. Nonetheless, these measurements do offer insight into the performance of several of the cryostat components and sub-systems.

  17. 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.

  18. 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.

  19. 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

  20. 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).

  1. 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.

  2. 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.

  3. 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.

  4. Measurement and quantification of aggregate thermal coefficient of expansion 

    E-Print Network [OSTI]

    Chande, Gautam U

    1997-01-01

    method of cells 18 Summary. CHAPTER III DESCRIPTION OF TEST METHOD 20 Introduction 20 Test method 20 Apparatus . Calibration. 20 . 22 Procedure 24 Sample preparation 25 Measurement 26 Results of dilatometer method. 27 Scanning electron... 46 64 . . . 71 LIST OF FIGURES Page Figure I Aggregate mortar matrix . 8 Figure 2 Models for concrete 17 Figure 3. Glass flask dilatometer Figure 4 Equipment components . Figure 5 Aggregate samples for measurement of thermal expansion 21 22...

  5. 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.

  6. Design and calibration of a test facility for MLI thermal performance measurements below 80K. [Multilayer insulation (MLI)

    SciTech Connect (OSTI)

    Boroski, W.; Kunzelman, R.; Ruschman, M.; Schoo, C.

    1992-04-01

    The design geometry of the SSC dipole cryostat includes active thermal radiation shields operating at 80K and 20K respectively. Extensive measurements conducted in a Heat Leak Test Facility (HLTF) have been used to evaluate the thermal performance of candidate multilayer insulation (MLI) systems for the 80K thermal shield, with the present system design based upon those measurement results. With the 80K MLI geometry established, efforts have focused on measuring the performance of MLI systems near 20K. A redesign of the HLTF has produced a measurement facility capable of conducting measurements with the warm boundary fixed at 80K and the cold boundary variable from 10K to 50K. Removing the 80K shield permits measurements with a warm boundary at 300K. The 80K boundary consists of a copper shield thermally anchored to a liquid nitrogen reservoir. The cold boundary consists of a copper anchor plate whose temperature is varied through boil-off gas from a 500 liter helium supply dewar. A transfer line heat exchanger supplies the boil-off gas to the anchor plate at a constant and controlled rate. The gas, which serves as cooling gas, is routed through a copper cooling tube soldered into the anchor plate. Varying the cooling gas flow rate varies the amount of refrigeration supplied to the anchor plate, thereby determining the plate temperature. A resistance heater installed on the anchor plate is regulated by a cryogenic temperature controller to provide final temperature control. Heat leak values are measured using a heatmeter which senses heat flow as a temperature gradient across a fixed thermal impedance. Since the thermal conductivity of the thermal impedance changes with temperature, the heatmeter is calibrated at key cold boundary temperatures. Thus, the system is capable of obtaining measurement data under a variety of system conditions. 7 refs.

  7. 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.

  8. High Resolution Viscosity Measurement by Thermal Noise Detection

    E-Print Network [OSTI]

    Sandoval, Felipe Aguilar; Bellon, Ludovic; Melo, Francisco

    2015-01-01

    An interferometric method is implemented in order to accurately assess the thermal fluctuations of a micro-cantilever sensor in liquid environments. The power spectrum density (PSD) of thermal fluctuations together with Sader's model of the cantilever allow for the indirect measurement of the liquid viscosity with good accuracy. The good quality of the deflection signal and the characteristic low noise of the instrument allow for the detection and corrections of drawbacks due to both the cantilever shape irregularities and the uncertainties on the position of the laser spot at the fluctuating end of the cantilever. Variation of viscosity below 0.03 mPa$\\cdot$s was detected with the alternative to achieve measurements with a volume as low as 50 $\\mu$L.

  9. 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

  10. 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

  11. 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

  12. 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...

  13. 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

  14. 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 $\\mu=0$.

  15. 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.

  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 water 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

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

  18. 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

  19. Simultaneous temperature and velocity Lagrangian measurements in turbulent thermal convection

    E-Print Network [OSTI]

    Liot, O; Zonta, F; Chibbaro, S; Coudarchet, T; Gasteuil, Y; Pinton, J -F; Salort, J; Chillà, F

    2015-01-01

    We report joint Lagrangian velocity and temperature measurements in turbulent thermal convection. Measurements are performed using an improved version (extended autonomy) of the neutrally-buoyant instrumented particle that was used by to performed experiments in a parallelepipedic Rayleigh-Benard cell. The temperature signal is obtained from a RFtransmitter. Simultaneously, we determine particle's position and velocity with one camera, which grants access to the Lagrangian heat flux. Due to the extended autonomy of the present particle, we obtain well converged temperature and velocity statistics, as well as pseudo-eulerian maps of velocity and heat flux. Present experimental results have also been compared with the results obtained by a corresponding campaign of Direct Numerical Simulations and Lagrangian Tracking of massless tracers. The comparison between experimental and numerical results show the accuracy and reliability of our experimental measurements. Finally, the analysis of lagrangian velocity and t...

  20. 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 ...

  1. Measurement of directional thermal infrared emissivity of vegetation and soils

    SciTech Connect (OSTI)

    Norman, J.M. [Wisconsin Univ., Madison, WI (United States). Dept. of Soil Science; Balick, L.K. [EG and G Energy Measurements, Inc., Las Vegas, NV (United States)

    1995-10-01

    A new method has been developed for measuring directional thermal emissivity as a function of view angle for plant canopies and soils using two infrared thermometers each sensitive to a different wavelength band. By calibrating the two infrared thermometers to 0.1C consistency, canopy directional emissivity can be estimated with typical errors less than 0.005 in the 8--14 um wavelength band, depending on clarity of the sky and corrections for CO{sub 2} absorption by the atmosphere. A theoretical justification for the method is developed along with an error analysis. Laboratory measurements were used to develop corrections for CO{sub 2}, absorption and a field calibration method is used to obtain the necessary 0.1C consistency for relatively low cost infrared thermometers. The emissivity of alfalfa (LAI=2.5) and corn (LAI=3.2) was near 0.995 and independent of view angle. Individual corn leaves had an emissivity of 0.97. A wheat (LAI=3.0) canopy had an emissivity of 0.985 at nadir and 0.975 at 75 degree view angle. The canopy emissivity values tend to be higher than values in the literature, and are useful for converting infrared thermometer measurements to kinetic temperature and interpreting satellite thermal observations.

  2. In situ changes in the moisture content of heated, welded tuff based on thermal neutron measurements

    SciTech Connect (OSTI)

    Ramirez, A.L.; Carlson, R.C.; Buscheck, T.A.

    1991-07-01

    Thermal neutron logs were collected to monitor changes in moisture content within a welded tuff rock mass heated from a borehole containing an electrical heater which remained energized for 195 days. Thermal neutron measurements were made in sampling boreholes before, during and after heating. The results generally corroborated our conceptual understanding of hydrothermal flow as well as most of the numerical modeling conducting for this study. Conceptual models have been developed in conjunction with the numerical model calculations to explain differences in the drying and re-wetting behavior above and below the heater. Numerical modeling indicated that the re-wetting of the dried-out zone was dominated by the binary diffusion of water vapor through fractures. Saturation gradients in the rock matrix resulted in relative humidity gradients which drove water vapor (primarily along fractures) back to the dried-out zone where it condensed along the fracture walls and was imbibed by the matrix. 4 refs., 28 figs.

  3. 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

  4. Measuring Frac-pack Conductivity at Reservoir Temperature and High Closure Stress 

    E-Print Network [OSTI]

    Fernandes, Preston X.

    2010-10-12

    through it and then measured conductivity by pumping oil to represent true reservoir conditions. Proppant performance and fracture fluids clean-up during production were examined. High strength proppant is ideal for deep fracture stimulations...

  5. 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

  6. Automated Rain Sampler for Real time pH and Conductivity Measurements

    E-Print Network [OSTI]

    Weerasinghe, R; Jayananda, M K; Sonnadara, D U J

    2015-01-01

    To monitor the acidity of rain water in real time, a rain water sampling system was developed. The rain sampler detects the initial rain after a dry spell and collects a water sample. Before performing the measurements, the pH probe is calibrated using a standard buffer solution whereas the conductivity probe is calibrated using deionized water. After calibrating the probes the pH and the conductivity of the collected rain water sample are measured using the pH and the conductivity probe. Weather parameters such as air temperature, humidity and pressure are also recorded simultaneously. The pH and conductivity measurement data including weather parameters are transmitted to central station using a GSM modem for further analysis. The collected rain water sample is preserved at the remote monitoring station for post chemical analysis. A programmable logic controller controls the entire process.

  7. 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

  8. 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

  9. 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

  10. 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

  11. 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...

  12. 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.

  13. 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

  14. 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.

  15. 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.

  16. In-Situ Thermal Conductivity Testing Using a Portable Heat Flow Meter 

    E-Print Network [OSTI]

    Harr, K. S.; Hutto, F. B., Jr.

    1979-01-01

    A method has been developed for measuring heat losses from insulated systems in the field. While the measurements are not as precise as those made under laboratory conditions, they are more indicative of actual in service conditions. Extensive field...

  17. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 52, NO. 3, JUNE 2003 839 Comparison of IC Conducted Emission

    E-Print Network [OSTI]

    of IC Conducted Emission Measurement Methods Franco Fiori, Member, IEEE, and Francesco Musolino, Member, IEEE Abstract--This paper deals with the electromagnetic emissions of integrated circuits. In particular, four measurement techniques to evaluate integrated circuit conducted emissions are described

  18. 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

  19. 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...

  20. Thermal performance measurements of a 100 percent polyester MLI (multilayer insulation) system for the Superconducting Super Collider

    SciTech Connect (OSTI)

    Gonczy, J.D.; Boroski, W.N.; Niemann, R.C.

    1989-09-01

    The plastic materials used in the multilayer insulation (MLI) blankets of the superconducting magnets of the Superconducting Super Collider (SSC) are comprised entirely of polyesters. This paper reports on tests conducted in three separate experimental blanket arrangements. The tests explore the thermal performance of two candidate blanket joint configurations each employing a variation of a stepped-butted joint nested between sewn blanket seams. The results from the joint configurations are compared to measurements made describing the thermal performance of the basic blanket materials as tested in an ideal joint configuration. Twenty foil sensors were incorporated within each test blanket to measure interstitial layer and joint layer temperatures. Heat flux and thermal gradients are reported for high and degraded insulating vacuums, and during transient and steady state conditions. In complement with this paper is an associate paper bearing the same title head but with the title extension Part 1: Instrumentation and experimental preparation (300K-80K)'. 5 refs., 8 figs., 2 tabs.

  1. Advancing Reactive Tracer Methods for Measuring Thermal Evolution...

    Open Energy Info (EERE)

    and Tracer Interpretation Project Description The concepts and theory behind the use of heat-sensitive tracers to study the thermal evolution of geothermal reservoirs was...

  2. 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

  3. 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.

  4. 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.

  5. 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...

  6. 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.

  7. Vibration-Induced Conductivity Fluctuation Measurement for Soil Bulk Density Analysis

    E-Print Network [OSTI]

    Andrea Sz. Kishne; Cristine L. S. Morgan; Hung-Chih Chang; Laszlo B. Kish

    2007-05-03

    Soil bulk density affects water storage, water and nutrient movement, and plant root activity in the soil profile. Its measurement is difficult in field conditions. Vibration-induced conductivity fluctuation was investigated to quantify soil bulk density with possible field applications in the future. The AC electrical conductivity of soil was measured using a pair of blade-like electrodes while exposing the soil to periodic vibration. The blades were positioned longitudinally and transversally to the direction of the induced vibration to enable the calculation of a normalized index. The normalized index was expected to provide data independent from the vibration strength and to reduce the effect of soil salinity and water content. The experiment was conducted on natural and salinized fine sand at two moisture conditions and four bulk densities. The blade-shaped electrodes improved electrode-soil contact compared to cylindrical electrodes, and thereby, reduced measurement noise. Simulations on a simplified resistor lattice indicate that the transversal effect increases as soil bulk density decreases. Measurement of dry sand showed a negative correlation between the normalized conductivity fluctuation and soil bulk density for both longitudinal and transversal settings. The decrease in the transversal signal was smaller than expected. The wet natural and salinized soils performed very similarly as hypothesized, but their normalized VICOF response was not significant to bulk density changes.

  8. 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

  9. Thermal diffusivity measurements in organic liquids using transient thermal lens calorimetry

    E-Print Network [OSTI]

    Harilal, S. S.

    renewed interest in the develop- ment of new methods of determining the thermal properties of materials in the context of the rapid advances in materials technology and the many new applications of materials under very severe environ- mental conditions. Thermal diffusivity of a material is a very important parameter

  10. Radiometric comparison of Mars Climate Sounder and Thermal Emission spectrometer measurements

    E-Print Network [OSTI]

    Bandfield, Joshua L.

    accounting for the local time differences. Any potential interannual variations in global average temperature Sounder (MCS) nadir oriented thermal infrared and solar channel measurements are com- pared with Thermal compared by convolving the TES data using the MCS spectral band passes. The MCS solar channel measurements

  11. Thermal Mediation in a Natural Littoral Wetland: Measurements and Modeling

    E-Print Network [OSTI]

    Andradottir, Hrund O.

    As a river flows through shallow littoral regions such as wetlands, forebays, and side arms, the temperature of the water is modified through atmospheric heat exchange. This process, which we call thermal mediation, can ...

  12. Thermal Transport Measurement of Silicon-Germanium Nanowires 

    E-Print Network [OSTI]

    Gwak, Yunki

    2010-10-12

    Thermal properties of one dimensional nanostructures are of interest for thermoelectric energy conversion. Thermoelectric efficiency is related to non dimensional thermoelectric figure of merit, ZT=S^2 o T/k, where S ,o , k and T are Seebeck...

  13. 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

  14. 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}.

  15. Measurement of K/sup +/ conductance in gastric vesicles from secreting stomach

    SciTech Connect (OSTI)

    Rabon, E.; Gunther, R.D.

    1986-05-01

    Specific inhibitors were used to identify two components of /sup 86/Rb/sup +/ uptake in vesicles obtained from secreting rabbit stomachs. Rb/sup +/ transport was measured in vesicles as trace /sup 86/Rb/sup +/ uptake following removal of external K/sup +/ from vesicles equilibrated in potassium gluconate. /sup 86/Rb)2= uptake mediated by the gastric H/sup +/K/sup +/-ATPase was identified by sensitivity to vanadate, ATP and pyridyl (1,2a) imidazole (SCH28080). In contrast, /sup 86/Rb/sup +/ influx through a K/sup +/ conductance mechanism was inhibited by the protonophore (TCS) induced collapse of the K/sup +/ diffusion potential. K/sup +/ conductance sensitivity to quinine and the K/sup +/ channel blocker bis-Guanidinium (bis G-8) were demonstrated by inhibition of a K/sup +/ induced chase of intravesicular /sup 86/Rb/sup +/ previously loaded by /sup 86/Rb/sup +//K/sup +/ exchange in the presence of 2 ..mu..M SCH28080. The K/sup +/ conductance is Ba/sup 2 +/ and apamine insensitive and exhibits a monovalent cation specificity of Rb > Kapprox. = Cs >> Na, Li. KCl dependent H/sup +/ transport exhibited complete sensitivity to the H/sup +/, K/sup +/-ATPase inhibitors SCH28080 and vanadate. The measurements of Rb/sup +/ pathways distinctive for the H/sup +/, K/sup +/-ATPase and a K/sup +/ conductance support previous suggestions of a functional linkage between the H/sup +/, K/sup +/-ATPase and a K/sup +/ conductance in vesicles, obtained from stimulated stomach. The experimental discrimination between the two Rb/sup +/ pathways suggests that a separate mechanism is utilized for each transport pathway.

  16. Experimental Development and Demonstration of Ultrasonic Measurement Diagnostics for Sodium Fast Reactor Thermal-hydraulics

    SciTech Connect (OSTI)

    Tokuhiro, Akira; Jones, Byron

    2013-09-13

    This research project will address some of the principal technology issues related to sodium-cooled fast reactors (SFR), primarily the development and demonstration of ultrasonic measurement diagnostics linked to effective thermal convective sensing under normatl and off-normal conditions. Sodium is well-suited as a heat transfer medium for the SFR. However, because it is chemically reactive and optically opaque, it presents engineering accessibility constraints relative to operations and maintenance (O&M) and in-service inspection (ISI) technologies that are currently used for light water reactors. Thus, there are limited sensing options for conducting thermohydraulic measurements under normal conditions and off-normal events (maintenance, unanticipated events). Acoustic methods, primarily ultrasonics, are a key measurement technology with applications in non-destructive testing, component imaging, thermometry, and velocimetry. THis project would have yielded a better quantitative and qualitative understanding of the thermohydraulic condition of solium under varied flow conditions. THe scope of work will evaluate and demonstrate ultrasonic technologies and define instrumentation options for the SFR.

  17. Measurement of thermal diffusivity of air using photopyroelectric interferometry

    E-Print Network [OSTI]

    Mandelis, Andreas

    of Mechanical and Industrial Engineering, University of Toronto, Toronto, Ontario M5S 3G8, Canada Received 9 is periodically heated using either a laser beam or direct ac electrical resistive heating; the other wall consists of the PVDF transducer itself at a distance L from the thermal-wave source wall. By scan- ning

  18. Design of A Conduction-cooled 4T Superconducting Racetrack for Multi-field Coupling Measurement System

    E-Print Network [OSTI]

    Chen, Yuquan; Wu, Wei; Guan, Mingzhi; Wu, Beimin; Mei, Enming; Xin, Canjie

    2015-01-01

    A conduction-cooled superconducting magnet producing a transverse field of 4 Tesla has been designed for the new generation multi-field coupling measurement system, which was used to study the mechanical behavior of superconducting samples at cryogenic temperature and intense magnetic fields. Considering experimental costs and coordinating with system of strain measurements by contactless signals (nonlinear CCD optics system), the racetrack type for the coil winding was chosen in our design, and a compact cryostat with a two-stage GM cryocooler was designed and manufactured for the superconducting magnet. The magnet was composed of a pair of flat racetrack coils wound by NbTi/Cu superconducting composite wires, a copper and stainless steel combinational form and two Bi2Sr2CaCu2Oy superconducting current leads. All the coils were connected in series and can be powered with a single power supply. The maximum central magnetic field is 4 T. In order to support the high stress and uniform thermal distribution in t...

  19. Development and validation of capabilities to measure thermal properties of layered monolithic U-Mo alloy plate-type fuel

    SciTech Connect (OSTI)

    Burkes, Douglas; Casella, Andrew M.; Buck, Edgar C.; Casella, Amanda J.; Edwards, Matthew K.; MacFarlan, Paul J.; Pool, Karl N.; Smith, Frances N.; Steen, Franciska H.

    2014-07-19

    The uranium-molybdenum (U-Mo) alloy in a monolithic form has been proposed as one fuel design capable of converting some of the world’s highest power research reactors from the use of high enriched uranium (HEU) to low enriched uranium (LEU). One aspect of the fuel development and qualification process is to demonstrate appropriate understanding of thermal conductivity behavior of the fuel system as a function of temperature and expected irradiation conditions. The purpose of this paper is to verify and validate the functionality of equipment methods installed in hot cells for eventual measurements on irradiated uranium-molybdenum (U-Mo) monolithic fuel specimens, procedures to operate the equipment, and models to extract the desired thermal properties. The results presented here demonstrate the adequacy of the equipment, procedures and models that have been developed for this purpose based on measurements conducted on surrogate depleted uranium-molybdenum (DU-Mo) alloy samples containing a zirconium diffusion barrier and clad in aluminum alloy 6061 (AA6061). The results are in excellent agreement with thermal property data reported in the literature for similar U-Mo alloys as a function of temperature.

  20. Lifetime Assessment for Thermal Barrier Coatings: Tests for Measuring Mixed Mode Delamination Toughness

    E-Print Network [OSTI]

    Hutchinson, John W.

    Lifetime Assessment for Thermal Barrier Coatings: Tests for Measuring Mixed Mode Delamination Mechanisms leading to degradation of the adherence of thermal barrier coatings (TBC) used in aircraft of coatings have not emerged based on predictions of the degradation processes due to their complexity

  1. StressCam: Non-contact Measurement of Users' Emotional States through Thermal Imaging

    E-Print Network [OSTI]

    states of computer users. The method is based on thermal imaging of the face. To the user, the imaging of Energy Expenditure (EE). The new method is highly correlated with the established, but awkward EEStressCam: Non-contact Measurement of Users' Emotional States through Thermal Imaging Colin Puri1

  2. Power Handling of the Bulk Tungsten Divertor Row at JET: First Measurements and Comparison to the GTM Thermal Model

    E-Print Network [OSTI]

    Power Handling of the Bulk Tungsten Divertor Row at JET: First Measurements and Comparison to the GTM Thermal Model

  3. Pararell Electron temperature and Density Gradients measured in the JET Mk I Divertor using Thermal Helium Beams

    E-Print Network [OSTI]

    Pararell Electron temperature and Density Gradients measured in the JET Mk I Divertor using Thermal Helium Beams

  4. Thermal performance measurements of a 100 percent polyester MLI (multilayer insulation) system for the Superconducting Super Collider

    SciTech Connect (OSTI)

    Boroski, W.N.; Gonczy, J.D.; Niemann, R.C.

    1989-09-01

    Thermal performance measurements of a 100 percent polyester multilayer insulation (MLI) system for the Superconducting Super Collider (SSC) were conducted in a Heat Leak Test Facility (HLTF) under three experimental test arrangements. Each experiment measured the thermal performance of a 32-layer MLI blanket instrumented with twenty foil sensors to measure interstitial layer temperatures. Heat leak values and sensor temperatures were monitored during transient and steady state conditions under both design and degraded insulating vacuums. Heat leak values were measured using a heatmeter. MLI interstitial layer temperatures were measured using Cryogenic Linear Temperature Sensors (CLTS). Platinum resistors monitored system temperatures. High vacuum was measured using ion gauges; degraded vacuum employed thermocouple gauges. A four-wire system monitored instrumentation sensors and calibration heaters. An on-line computerized data acquisition system recorded and processes data. This paper reports on the instrumentation and experimental preparation used in carrying out these measurements. In complement with this paper is an associate paper bearing the same title head, but with the title extension Part 2: Laboratory results (300K--80K). 13 refs., 7 figs.

  5. Comparison of Dynamic Data Analysis Methods for Thermal Property Measurement of a Building Wall 

    E-Print Network [OSTI]

    Huang, K.; Gong, Y.

    2006-01-01

    results more accurate. In this paper, two methods for analyzing the building wall's thermal transmittance, where data is measured on site, are presented. They are respectively called the dynamic analysis method and the system identification method. The two...

  6. Development of a nanostructure thermal property measurement platform compatible with a transmission electron microscope

    E-Print Network [OSTI]

    Harris, C. Thomas (Charles Thomas)

    2010-01-01

    Measurements of the electrical and thermal transport properties of one-dimensional nanostructures (e.g., nanotubes and nanowires) typically are obtained without detailed knowledge of the specimen's atomicscale structure ...

  7. 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.

  8. ESTIMATION OF IN-SITU THERMAL CONDUCTIVITIES FROM TEMPERATURE GRADIENT MEASUREMENTS

    E-Print Network [OSTI]

    Hoang, V.T.

    2010-01-01

    to Evaluate Regional Geothermal Gradients t " Journal ofin wells, a linear geothermal gradient profile has beenfluid saturations. The geothermal gradient is caused by the

  9. Measurement of Thermal Conductivity of PbTe Nanocrystal Coated Glass Fibers by the 3 Method

    E-Print Network [OSTI]

    Ruan, Xiulin

    to curved surfaces to form energy harvesting devices for waste heat recovery. Here we investigate materials such as nanocomposites1 and fibers2 can significantly impact waste heat recovery and solid

  10. 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 . . . . . . . . . . . . . . . .

  11. Transient Non-linear Thermal FEM Simulation of Smart Power Switches and Verification by Measurements

    E-Print Network [OSTI]

    V. Kosel; R. Sleik; M. Glavanovics

    2008-01-07

    Thermal FEM (Finite Element Method) simulations can be used to predict the thermal behavior of power semiconductors in application. Most power semiconductors are made of silicon. Silicon thermal material properties are significantly temperature dependent. In this paper, validity of a common non-linear silicon material model is verified by transient non-linear thermal FEM simulations of Smart Power Switches and measurements. For verification, over-temperature protection behavior of Smart Power Switches is employed. This protection turns off the switch at a pre-defined temperature which is used as a temperature reference in the investigation. Power dissipation generated during a thermal overload event of two Smart Power devices is measured and used as an input stimulus to transient thermal FEM simulations. The duration time of the event together with the temperature reference is confronted with simulation results and thus the validity of the silicon model is proved. In addition, the impact of non-linear thermal properties of silicon on the thermal impedance of power semiconductors is shown.

  12. 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

  13. Detailed thermal performance measurements and cost effectiveness of earth-sheltered construction: a case study

    SciTech Connect (OSTI)

    Christian, J.E.

    1985-09-01

    Earth-covering, solar gain, and massive construction are the design concepts successfully blended to produce an energy-efficient, durable, and comfortable building. Twenty-four-hour-quiet sleeping quarters and quality office space were the first design objectives of this building, these were successfully accomplished. The data acquisition system and a unique energy-balance analysis documents the thermal performance of each envelope component. Since the building's typical number of occupants, size, and internal electric loads are similar to those of a large residential building, the energy-performance data are extended to the residential marketplace. First-cost estimates for the whole building, earth-covered roof, and bermed wall are used with the detailed measured energy-use data to estimate cost effectiveness using residential economics criteria, such as 3% discount rate and 30-year life. The results from this analysis confirm the fact that earth, sun, and mass can save substantial amounts of annual and peak energy demand. However, further construction cost reductions are needed to produce more favorable cost effectiveness in the residential market arena. The overall thermal conductance value of this building is lower than the average values from the 300 low-energy residences as reported in the Building Energy-Use Compilation and Analysis, Part A (BECA-A), data base. However, the balance point of this building, with mechanical ventilation to ensure about 0.5 air change per hour, is substantially higher than those reported for low-energy residential buildings. This suggests that most of the energy-efficient homes either have an air-to-air heat exchanger or infiltration levels far below the generally accepted 0.5 air change per hour to ensure healthy indoor air quality. Reflective insulating blinds were installed in this building and have enhanced the daylighting and usability of the building. 9 refs., 23 figs., 4 tabs.

  14. A Measurement Method of Actual Thermal Performance of Detached Houses 

    E-Print Network [OSTI]

    Iwamae, A.; Nagai, H.; Miura, H.

    2004-01-01

    method in Japan if people don?t have time of more than 3 days for the measurement and have many measurement tools. The other hand, SP (Swedish National Testing and Resear itute) have developed the testing method for prefabricated house which is based... OF DETACHED HOUSES Atsushi IWAMAE Associate Professor, Department of Architecture, Sc l of Science and Engineering, Kinki University 3-4-1 Kowakae, Higashi-Osaka, Japan 577-8502 Hisaya NAGAI Associate Professor, Department of Architecture, Faculty...

  15. 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...

  16. Solar wind electron temperature and density measurements on the Solar Orbiter with thermal noise spectroscopy

    E-Print Network [OSTI]

    California at Berkeley, University of

    for the Solar Orbiter mission. One can already figure out what could be the Te gra- dients in this radial rangeSolar wind electron temperature and density measurements on the Solar Orbiter with thermal noise Abstract The measurement of the solar wind electron temperature in the unexplored region between 1 and 45

  17. Title: StressCam: Non-contact Measurement of Users' Emotional States through Thermal Imaging

    E-Print Network [OSTI]

    , and compared against real-time measurements of Energy Expenditure (EE). The new method is highly correlatedTitle: StressCam: Non-contact Measurement of Users' Emotional States through Thermal Imaging: We present a novel methodology for monitoring the affective state of computer users. The method

  18. Calibration-free measurement of liquid permittivity and conductivity using electrochemical impedance test cell with servomechanically adjustable cell constant

    E-Print Network [OSTI]

    Slocum, Alexander H.

    This paper presents a technique and a device for measuring the permittivity and conductivity of liquids and gases that does not require prior calibration by a reference sample. The technique involves precisely controlling ...

  19. A method for measuring non-linear elastic properties of thermal barrier coatings

    SciTech Connect (OSTI)

    Johnson, C.A.; Ruud, J.A.; Kaya, A.C.; deLorenzi, H.G.

    1995-06-01

    Accurate characterization of the elastic properties of thermal barrier coatings (TBC`s) is important for failure prediction. Thermally sprayed coatings often exhibit anisotropic and nonlinear elastic properties due to the coating microstructure that results from the thermal spray process. A method was developed for determining the elastic behavior of TBC`s on substrates by measuring the in-plane modulus as a function of residual coating stress. The in-plane modulus was determined by resonant frequency measurement, and the residual stress was measured from the substrate curvature. The residual stress was varied both by increasing the temperature of the TBC and substrate and by applying compressive plastic strain to the metal substrate. The stress-strain behavior of the TBC was derived from the data for modulus versus residual stress, and significant nonlinear elastic behavior was observed.

  20. 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...

  1. Summary In July 1993, we measured leaf conductance, carbon dioxide (CO2) assimilation, and transpiration in a Larix

    E-Print Network [OSTI]

    Summary In July 1993, we measured leaf conductance, carbon dioxide (CO2) assimilation to the value of 1.45 mm day-1 calculated from the energy balance and soil evaporation, and less than the value of 2.1mmday-1 measured by xylem flux. Daytime canopy carbon assimilation, expressed on a ground area

  2. Electrical conductivity measurements of aqueous boric acid at 25--350{degree}C at saturation vapor pressure. Final report

    SciTech Connect (OSTI)

    Ho, P.C.; Palmer, D.A.

    1995-09-01

    Electrical conductance measurements of aqueous boric acid solutions (15-110 g/kg-H{sub 2}O {equivalent_to} 0.251--1.815 mol/kg-H{sub 2}O) were measured over the temperature range 25 to 75 C at saturation vapor pressures in glass cells with parallel platinum electrodes. Sixteen series of measurements were made involving three samples of boric acid from different sources. Conductance measurements were also made at 15.5 and 30.5 g/kg-H{sub 2}O over the temperature range 100 to 350 C at 50 C intervals with a metallic cell fitted with concentric platinum electrodes. The specific conductances of H{sub 3}BO{sub 3} (aq)were calculated after correction for the conductance of the solvent (water) and are tabulated in this report. At the specific conditions requested in the project description, namely a concentration of 110 g/kg-H{sub 2}O and 65 C, the specific conductance of boric acid is 293.2 {+-} 1.8 microSiemens/cm based on duplicate measurements of four independent solutions. The results from these tests will be utilized by the Tokamak Physics Experimental Project (TPX).

  3. Quantum optimality of photon counting for temperature measurement of thermal astronomical sources

    E-Print Network [OSTI]

    Ranjith Nair; Mankei Tsang

    2015-07-28

    Using the quantum Cram\\'{e}r-Rao bound from quantum estimation theory, we derive a fundamental quantum limit on the sensitivity of a temperature measurement of a thermal astronomical source. This limit is expressed in terms of the source temperature $T_s$, input spectral bandwidth $\\Delta \

  4. Signal generation mechanisms, intracavity-gas thermal-diffusivity temperature dependence, and absolute infrared emissivity measurements

    E-Print Network [OSTI]

    Mandelis, Andreas

    Diagnostics Laboratories (PODL), University of Toronto, 5 King's College Road, Toronto, Ontario M5S 3G8 boundary layer adjacent to the cavity thermal source a metallic Cr­Ni alloy strip . This resulted cavity lengths allowed the measurement of the absolute infrared emissivity of the thin Cr­Ni strip source

  5. Measurements of thermal transport in low stress silicon nitride films W. Holmes,a)

    E-Print Network [OSTI]

    Richards, Paul L.

    Measurements of thermal transport in low stress silicon nitride films W. Holmes,a) J. M. Gildemeister, and P. L. Richardsb) Physics Department, University of California, Berkeley, California 94720 and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 V. Kotsuboc

  6. Solar wind electron density and temperature over solar cycle 23: Thermal noise measurements on Wind

    E-Print Network [OSTI]

    California at Berkeley, University of

    Solar wind electron density and temperature over solar cycle 23: Thermal noise measurements on Wind; received in revised form 6 April 2005; accepted 25 April 2005 Abstract We present the solar wind plasma parameters obtained from the Wind spacecraft during more than nine years, encompassing almost the whole solar

  7. Laboratory evaluation of the constant rate of strain and constant head techniques for measurement of the hydraulic conductivity of fine grained soils

    E-Print Network [OSTI]

    Adams, Amy Lynn

    2011-01-01

    This thesis evaluates the constant rate of strain and constant head techniques for measurement of the hydraulic conductivity of fine grained soils. A laboratory program compares hydraulic conductivity measurements made ...

  8. 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

  9. Measurements of Non-Thermal Line Widths in Solar Active Regions

    E-Print Network [OSTI]

    Brooks, David H

    2015-01-01

    Spectral line widths are often observed to be larger than can be accounted for by thermal and instrumental broadening alone. This excess broadening is a key observational constraint for both nanoflare and wave dissipation models of coronal heating. Here we present a survey of non-thermal velocities measured in the high temperature loops (1--5MK) often found in the cores of solar active regions. This survey of $\\textit{Hinode}$ Extreme Ultraviolet Imaging Spectrometer (EIS) observations covers 15 non-flaring active regions that span a wide range of solar conditions. We find relatively small non-thermal velocities, with a mean value of 17km s$^{-1}$, and no significant trend with temperature or active region magnetic flux. These measurements appear to be inconsistent with those expected from reconnection jets in the corona, chromospheric evaporation induced by coronal nanoflares, and Alfv\\'en wave turbulence models. Furthermore, because the observed non-thermal widths are generally small their measurements are ...

  10. Pointer-based simultaneous measurements of conjugate observables in a thermal environment

    E-Print Network [OSTI]

    Raoul Heese; Matthias Freyberger

    2014-05-06

    We combine traditional pointer-based simultaneous measurements of conjugate observables with the concept of quantum Brownian motion of multipartite systems to phenomenologically model simultaneous measurements of conjugate observables in a thermal environment. This approach provides us with a formal solution of the complete measurement dynamics for quadratic Hamiltonians and we can therefore discuss the measurement uncertainty and optimal measurement times. As a main result, we obtain a lower bound for the uncertainty of a noisy measurement, which is an extension of a previously known uncertainty relation and in which the squeezing of the system state to be measured plays an important role. This also allows us to classify minimal uncertainty states in more detail.

  11. 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

  12. The measurement of eddy current conductivity, in view of its frequen-cy dependent penetration depth, has been suggested as a possible means to

    E-Print Network [OSTI]

    Nagy, Peter B.

    ABSTRACT The measurement of eddy current conductivity, in view of its frequen- cy dependent of the near surface electrical conductivity measured by the eddy current method in the presence of surface dissipated, leaving only the surface roughness. Eddy current electri- cal conductivity measurements were

  13. 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.

  14. 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.

  15. Measurement of total ultrasonic power using thermal expansion and change in buoyancy of an absorbing target

    SciTech Connect (OSTI)

    Dubey, P. K. Kumar, Yudhisther; Gupta, Reeta; Jain, Anshul; Gohiya, Chandrashekhar

    2014-05-15

    The Radiation Force Balance (RFB) technique is well established and most widely used for the measurement of total ultrasonic power radiated by ultrasonic transducer. The technique is used as a primary standard for calibration of ultrasonic transducers with relatively fair uncertainty in the low power (below 1 W) regime. In this technique, uncertainty comparatively increases in the range of few watts wherein the effects such as thermal heating of the target, cavitations, and acoustic streaming dominate. In addition, error in the measurement of ultrasonic power is also caused due to movement of absorber at relatively high radiated force which occurs at high power level. In this article a new technique is proposed which does not measure the balance output during transducer energized state as done in RFB. It utilizes the change in buoyancy of the absorbing target due to local thermal heating. The linear thermal expansion of the target changes the apparent mass in water due to buoyancy change. This forms the basis for the measurement of ultrasonic power particularly in watts range. The proposed method comparatively reduces uncertainty caused by various ultrasonic effects that occur at high power such as overshoot due to momentum of target at higher radiated force. The functionality of the technique has been tested and compared with the existing internationally recommended RFB technique.

  16. Report on Thermal Neutron Diffusion Length Measurement in Reactor Grade Graphite Using MCNP and COMSOL Multiphysics

    E-Print Network [OSTI]

    S. R. Mirfayzi

    2013-01-08

    Neutron diffusion length in reactor grade graphite is measured both experimentally and theoretically. The experimental work includes Monte Carlo (MC) coding using 'MCNP' and Finite Element Analysis (FEA) coding suing 'COMSOL Multiphysics' and Matlab. The MCNP code is adopted to simulate the thermal neutron diffusion length in a reactor moderator of 2m x 2m with slightly enriched uranium ($^{235}U$), accompanied with a model designed for thermal hydraulic analysis using point kinetic equations, based on partial and ordinary differential equation. The theoretical work includes numerical approximation methods including transcendental technique to illustrate the iteration process with the FEA method. Finally collision density of thermal neutron in graphite is measured, also specific heat relation dependability of collision density is also calculated theoretically, the thermal neutron diffusion length in graphite is evaluated at $50.85 \\pm 0.3cm$ using COMSOL Multiphysics and $50.95 \\pm 0.5cm$ using MCNP. Finally the total neutron cross-section is derived using FEA in an inverse iteration form.

  17. Conductivity measurements on H2O-bearing CO2-rich fluids

    SciTech Connect (OSTI)

    Capobianco, Ryan [Virginia Polytechnic Institute and State University; Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Bodnar, Robert [Virginia Polytechnic Institute and State University; Rimstidt, J. Donald [Virginia Polytechnic Institute and State University

    2015-01-01

    Recent studies report rapid corrosion of metals and carbonation of minerals in contact with carbon dioxide containing trace amounts of dissolved water. One explanation for this behavior is that addition of small amounts of H2O to CO2 leads to significant ionization within the fluid, thus promoting reactions at the fluid-solid interface analogous to corrosion associated with aqueous fluids. The extent of ionization in the bulk CO2 fluid was determined using a flow-through conductivity cell capable of detecting very low conductivities. Experiments were conducted from 298 to 473 K and 7.39 to 20 MPa with H2O concentrations up to ~1600 ppmw (xH2O 3.9 10-3), corresponding to the H2O solubility limit in liquid CO2 at ambient temperature. All solutions showed conductivities <10 nS/cm, indicating that the solutions were essentially ion-free. This observation suggests that the observed corrosion and carbonation reactions are not the result of ionization in CO2-rich bulk phase, but does not preclude ionization in the fluid at the fluid-solid interface.

  18. Absolute measurement of thermal noise in a resonant short-range force experiment

    E-Print Network [OSTI]

    H. Yan; E. A. Housworth; H. O. Meyer; G. Visser; E. Weisman; J. C. Long

    2014-10-23

    Planar, double-torsional oscillators are especially suitable for short-range macroscopic force search experiments, since they can be operated at the limit of instrumental thermal noise. As a study of this limit, we report a measurement of the noise kinetic energy of a polycrystalline tungsten oscillator in thermal equilibrium at room temperature. The fluctuations of the oscillator in a high-Q torsional mode with a resonance frequency near 1 kHz are detected with capacitive transducers coupled to a sensitive differential amplifier. The electronic processing is calibrated by means of a known electrostatic force and input from a finite element model. The measured average kinetic energy is in agreement with the expected value of 1/2 kT.

  19. 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.

  20. Thermal history sensors for non-destructive temperature measurements in harsh environments

    SciTech Connect (OSTI)

    Pilgrim, C. C.; Heyes, A. L.; Feist, J. P.

    2014-02-18

    The operating temperature is a critical physical parameter in many engineering applications, however, can be very challenging to measure in certain environments, particularly when access is limited or on rotating components. A new quantitative non-destructive temperature measurement technique has been proposed which relies on thermally induced permanent changes in ceramic phosphors. This technique has several distinct advantages over current methods for many different applications. The robust ceramic material stores the temperature information allowing long term thermal exposures in harsh environment to be measured at a convenient time. Additionally, rare earth dopants make the ceramic phosphorescent so that the temperature information can be interpreted by automated interrogation of the phosphorescent light. This technique has been demonstrated by application of YAG doped with dysprosium and europium as coatings through the air-plasma spray process. Either material can be used to measure temperature over a wide range, namely between 300°C and 900°C. Furthermore, results show that the material records the peak exposure temperature and prolonged exposure at lower temperatures would have no effect on the temperature measurement. This indicates that these materials could be used to measure peak operating temperatures in long-term testing.

  1. Measurement of neutron capture on $^{48}$Ca at thermal and thermonuclear energies

    E-Print Network [OSTI]

    H. Beer; C. Coceva; P. V. Sedyshev; Yu. P. Popov; H. Herndl; R. Hofinger; P. Mohr; H. Oberhummer

    1996-08-07

    At the Karlsruhe pulsed 3.75\\,MV Van de Graaff accelerator the thermonuclear $^{48}$Ca(n,$\\gamma$)$^{49}$Ca(8.72\\,min) cross section was measured by the fast cyclic activation technique via the 3084.5\\,keV $\\gamma$-ray line of the $^{49}$Ca-decay. Samples of CaCO$_3$ enriched in $^{48}$Ca by 77.87\\,\\% were irradiated between two gold foils which served as capture standards. The capture cross-section was measured at the neutron energies 25, 151, 176, and 218\\,keV, respectively. Additionally, the thermal capture cross-section was measured at the reactor BR1 in Mol, Belgium, via the prompt and decay $\\gamma$-ray lines using the same target material. The $^{48}$Ca(n,$\\gamma$)$^{49}$Ca cross-section in the thermonuclear and thermal energy range has been calculated using the direct-capture model combined with folding potentials. The potential strengths are adjusted to the scattering length and the binding energies of the final states in $^{49}$Ca. The small coherent elastic cross section of $^{48}$Ca+n is explained through the nuclear Ramsauer effect. Spectroscopic factors of $^{49}$Ca have been extracted from the thermal capture cross-section with better accuracy than from a recent (d,p) experiment. Within the uncertainties both results are in agreement. The non-resonant thermal and thermonuclear experimental data for this reaction can be reproduced using the direct-capture model. A possible interference with a resonant contribution is discussed. The neutron spectroscopic factors of $^{49}$Ca determined from shell-model calculations are compared with the values extracted from the experimental cross sections for $^{48}$Ca(d,p)$^{49}$Ca and $^{48}$Ca(n,$\\gamma$)$^{49}$Ca.

  2. Effect of electrode configuration and electronic conductivity on current density distribution measurements in PEM fuel cells

    E-Print Network [OSTI]

    Natarajan, Dilip; Van Nguyen, Trung

    2004-09-03

    and pollution free characteristics make them an attractive option for terrestrial applications. Of the various types of fuel cells available, Proton Exchange Membrane (PEMFC) fuel cells are considered to be most suitable for transportation and portable... to the catalyst layer and electrode width along the channel, 2) The ratio of in-plane and through-plane area, 3) The ratio of in-plane and through-plane conductivities of the GDL material and finally, 4) The relative contact resistances between the GDL...

  3. New contactless method for thermal diffusivity measurements using modulated photothermal radiometry

    SciTech Connect (OSTI)

    Pham Tu Quoc, S. Cheymol, G.; Semerok, A.

    2014-05-15

    Modulated photothermal radiometry is a non-destructive and contactless technique for the characterization of materials. It has two major advantages: a good signal-to-noise ratio through a synchronous detection and a low dependence on the heating power and the optical properties of the sample surface. This paper presents a new method for characterizing the thermal diffusivity of a material when the phase shift between a modulated laser power signal and the thermal signal of a plate sample is known at different frequencies. The method is based on a three-dimensional analytical model which is used to determine the temperature amplitude and the phase in the laser heating of the plate. A new simple formula was developed through multi-parametric analysis to determine the thermal diffusivity of the plate with knowledge of the frequency at the minimum phase shift, the laser beam radius r{sub 0} and the sample thickness L. This method was developed to control the variation of the thermal diffusivity of nuclear components and it was first applied to determine the thermal diffusivity of different metals: 304 L stainless steel, nickel, titanium, tungsten, molybdenum, zinc, and iron. The experimental results were obtained with 5%–10% accuracy and corresponded well with the reference values. The present paper also demonstrates the limit of application of this method for plate with thickness r{sub 0}/100 ? L ? r{sub 0}/2. The technique is deemed interesting for the characterization of barely accessible components that require a contactless measurement.

  4. Measurement of cryogenic moderator temperature effects in a small heterogeneous thermal reactor

    SciTech Connect (OSTI)

    Hoovler, G.S.; Ball, R.M.; Lewis, R.H.

    1994-12-31

    Past papers have described a critical experiment (CX) built at Sandia National Laboratories to investigate the neutronic behavior of the particle-bed reactor (PBK). Among the experiments previously reported were tests to measure the reactivity effect of uniform temperature variations between 20 and 80{degree}C. This paper describes additional experiments designed to examine the effects of cryogenic moderator temperatures on core reactivity and neutron spectrum. The general importance of temperature effects to the design of the PBR have been previously discussed. A unique feature of the PBR is that the moderator may be at cryogenic temperatures during reactor startup. Because temperature effects in small, heterogeneous thermal reactors can be significant and because we found no integral measurements with cryogenic moderators in such systems, an experiment with a cryogenic moderator was designed and performed in the CX as an extension to the isothermal measurements previously reported.

  5. An Information-Theoretic Measure of Uncertainty due to Quantum and Thermal Fluctuations

    E-Print Network [OSTI]

    Arlen Anderson; Jonathan J. Halliwell

    1993-04-28

    We study an information-theoretic measure of uncertainty for quantum systems. It is the Shannon information $I$ of the phase space probability distribution $\\la z | \\rho | z \\ra $, where $|z \\ra $ are coherent states, and $\\rho$ is the density matrix. The uncertainty principle is expressed in this measure as $I \\ge 1$. For a harmonic oscillator in a thermal state, $I$ coincides with von Neumann entropy, $- \\Tr(\\rho \\ln \\rho)$, in the high-temperature regime, but unlike entropy, it is non-zero at zero temperature. It therefore supplies a non-trivial measure of uncertainty due to both quantum and thermal fluctuations. We study $I$ as a function of time for a class of non-equilibrium quantum systems consisting of a distinguished system coupled to a heat bath. We derive an evolution equation for $I$. For the harmonic oscillator, in the Fokker-Planck regime, we show that $I$ increases monotonically. For more general Hamiltonians, $I$ settles down to monotonic increase in the long run, but may suffer an initial decrease for certain initial states that undergo ``reassembly'' (the opposite of quantum spreading). Our main result is to prove, for linear systems, that $I$ at each moment of time has a lower bound $I_t^{min}$, over all possible initial states. This bound is a generalization of the uncertainty principle to include thermal fluctuations in non-equilibrium systems, and represents the least amount of uncertainty the system must suffer after evolution in the presence of an environment for time $t$.

  6. A thermal method for measuring the rate of water movement in plants 

    E-Print Network [OSTI]

    Bloodworth, Morris Elkins

    1958-01-01

    L?BP A 8 V a L ?BPA8B8 op A THERMAL METHOD FOR MEASURING THE RATE OF WATER MOVEMENT IN PLANTS A Dissertation By Morris Elkins Bloodworth Vao Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in Partial... ??BLA? ? ? ? ? ? ?? ?B?8?8?A B? ??A8? o? ????A???????????? ?? ??? ?????????^pP ??^i?? ?????????????????????????? ?? p? ??B?8???8? ??? ???A???8?A?AoB? ? ? ? ? ?? ?? ^8?A ???o?oAo8? ? ????A ???o?B??8?A?? ?B?A?B? ? ? o A...

  7. Apparatus for characterizing conductivity of materials by measuring the effect of induced shielding currents therein

    DOE Patents [OSTI]

    Doss, James D. (Los Alamos, NM)

    1991-01-01

    Apparatus and method for noncontact, radio-frequency shielding current characterization of materials. Self- or mutual inductance changes in one or more inductive elements, respectively, occur when materials capable of supporting shielding currents are placed in proximity thereto, or undergo change in resistivity while in place. Such changes can be observed by incorporating the inductor(s) in a resonant circuit and determining the frequency of oscillation or by measuring the voltage induced on a coupled inductive element. The present invention is useful for determining the critical temperature and superconducting transition width for superconducting samples.

  8. Apparatus for characterizing conductivity of materials by measuring the effect of induced shielding currents therein

    DOE Patents [OSTI]

    Doss, J.D.

    1991-05-14

    Apparatus and method for noncontact, radio-frequency shielding current characterization of materials is disclosed. Self- or mutual inductance changes in one or more inductive elements, respectively, occur when materials capable of supporting shielding currents are placed in proximity thereto, or undergo change in resistivity while in place. Such changes can be observed by incorporating the inductor(s) in a resonant circuit and determining the frequency of oscillation or by measuring the voltage induced on a coupled inductive element. The present invention is useful for determining the critical temperature and superconducting transition width for superconducting samples. 10 figures.

  9. Evidence of thermal conduction suppression in a solar flaring loop by coronal seismology of slow-mode waves

    E-Print Network [OSTI]

    Wang, Tongjiang; Sun, Xudong; Provornikova, Elena; Davila, Joseph M

    2015-01-01

    Analysis of a longitudinal wave event observed by the Atmospheric Imaging Assembly (AIA) onboard the Solar Dynamics Observatory (SDO) is presented. A time sequence of 131 A images reveals that a C-class flare occurred at one footpoint of a large loop and triggered an intensity disturbance (enhancement) propagating along it. The spatial features and temporal evolution suggest that a fundamental standing slow-mode wave could be set up quickly after meeting of two initial disturbances from the opposite footpoints. The oscillations have a period of ~12 min and a decay time of ~9 min. The measured phase speed of 500$\\pm$50 km/s matches the sound speed in the heated loop of ~10 MK, confirming that the observed waves are of slow mode. We derive the time-dependent temperature and electron density wave signals from six AIA extreme-ultraviolet (EUV) channels, and find that they are nearly in phase.The measured polytropic index from the temperature and density perturbations is 1.64$\\pm$0.08 close to the adiabatic index ...

  10. Kinetic Monte Carlo Simulations and Molecular Conductance Measurements of the Bacterial Decaheme Cytochrome MtrF

    SciTech Connect (OSTI)

    Byun, H. S.; Pirbadian, S.; Nakano, Aiichiro; Shi, Liang; El-Naggar, Mohamed Y.

    2014-09-05

    Microorganisms overcome the considerable hurdle of respiring extracellular solid substrates by deploying large multiheme cytochrome complexes that form 20 nanometer conduits to traffic electrons through the periplasm and across the cellular outer membrane. Here we report the first kinetic Monte Carlo simulations and single-molecule scanning tunneling microscopy (STM) measurements of the Shewanella oneidensis MR-1 outer membrane decaheme cytochrome MtrF, which can perform the final electron transfer step from cells to minerals and microbial fuel cell anodes. We find that the calculated electron transport rate through MtrF is consistent with previously reported in vitro measurements of the Shewanella Mtr complex, as well as in vivo respiration rates on electrode surfaces assuming a reasonable (experimentally verified) coverage of cytochromes on the cell surface. The simulations also reveal a rich phase diagram in the overall electron occupation density of the hemes as a function of electron injection and ejection rates. Single molecule tunneling spectroscopy confirms MtrF's ability to mediate electron transport between an STM tip and an underlying Au(111) surface, but at rates higher than expected from previously calculated heme-heme electron transfer rates for solvated molecules.

  11. SEMI-THERM 21, SEMICONDUCTOR THERMAL MEASUREMENT AND MANAGMENT SYMPOSIUM, SAN JOSE. MAR 15-17, 2005. 1 Thermal Contact Resistance: Effect of Elastic

    E-Print Network [OSTI]

    Bahrami, Majid

    in the microelectronics industry is low due to load constraints. In this paper a new model is presented which is moreSEMI-THERM 21, SEMICONDUCTOR THERMAL MEASUREMENT AND MANAGMENT SYMPOSIUM, SAN JOSE. MAR 15-17, 2005 elastic modulus, Pa F = applied load, N Hmic = microhardness, Pa H = non-dimensional microhardness Hmic

  12. 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

  13. A compact and miniaturized high resolution capacitance dilatometer for measuring thermal expansion and magnetostriction

    SciTech Connect (OSTI)

    Kuechler, R.; Bauer, T.; Brando, M.; Steglich, F.

    2012-09-15

    We describe the design, construction, calibration, and two different applications of a miniature capacitance dilatometer. The device is suitable for thermal expansion and magnetostriction measurements from 300 K down to about 25 mK, with a resolution of 0.02 A at low temperatures. The main body of the dilatometer is fabricated from a single block of a Be-Cu alloy by electrical discharge milling. This creates an extremely compact high-resolution measuring cell. We have successfully tested and operated dilatometers of this new type with the commonly used physical property measurement system by quantum design, as well as with several other cryogenic refrigeration systems down to 25 mK and in magnetic fields up to 20 T. Here, the capacitance is measured with a commercially available capacitance bridge. Using a piezoelectric rotator from Attocube Systems, the cell can be rotated at T= 25 mK inside of an inner vacuum chamber of 40 mm diameter. The miniaturized design for the one-axis rotation setup allows a rotation of 360 Degree-Sign .

  14. Strains in Thermally Growing Alumina Films Measured in-situ usingSynchrotron X-rays

    SciTech Connect (OSTI)

    Hou, P.Y.; Paulikas, A.P.; Veal, B.W.

    2006-01-02

    Strains in thermally grown oxides have been measured in-situ, as the oxides develop and evolve. Extensive data have been acquired from oxides grown in air at elevated temperatures on different model alloys that form Al{sub 2}O{sub 3}. Using synchrotron x-rays at the Advanced Photon Source (Beamline 12BM, Argonne National Laboratory), Debye-Scherrer diffraction patterns from the oxidizing specimen were recorded every 5 minutes during oxidation and subsequent cooling. The diffraction patterns were analyzed to determine strains in the oxides, as well as phase changes and the degree of texture. To study a specimen's response to stress perturbation, the oxidizing temperature was quickly cooled from 1100 to 950 C to impose a compressive thermal stress in the scale. This paper describes this new experimental approach and gives examples from oxidized {beta}-NiAl, Fe-20Cr-10Al, Fe-28Al-5Cr and H{sub 2}-annealed Fe-28Al-5Cr (all at. %) alloys to illustrate some current understanding of the development and relaxation of growth stresses in Al{sub 2}O{sub 3}.

  15. Benchmark Test of Differential Emission Measure Codes and Multi-Thermal Energies in Solar Active Regions

    E-Print Network [OSTI]

    Aschwanden, M J; Caspi, A; McTiernan, J M; Ryan, D; Warren, H P

    2015-01-01

    We compare the ability of 11 Differential Emission Measure (DEM) forward-fitting and inversion methods to constrain the properties of active regions and solar flares by simulating synthetic data using the instrumental response functions of SDO/AIA, SDO/EVE, RHESSI, and GOES/XRS. The codes include the single-Gaussian DEM, a bi-Gaussian DEM, a fixed-Gaussian DEM, a linear spline DEM, the spatial synthesis DEM, the Monte-Carlo Markov chain DEM, the regularized DEM inversion, the Hinode/XRT method, a polynomial spline DEM, an EVE+GOES, and an EVE+RHESSI method. Averaging the results from all 11 DEM methods, we find the following accuracies in the inversion of physical parameters: the EM-weighted temperature $T_w^{fit}/T_w^{sim}=0.9\\pm0.1$, the peak emission measure $EM_p^{fit}/EM_p^{sim}=0.6\\pm0.2$, the total emission measure $EM_t^{fit}/EM_t^{sim}=0.8\\pm0.3$, and the multi-thermal energies $E_{th}^{fit}/EM_{th}^{sim}=1.2\\pm0.4$. We find that the AIA spatial synthesis, the EVE+GOES, and the EVE+RHESSI method yiel...

  16. Intermttional Jourmtl ~/" Thermophysics. I,'ol. 18. No. I. 1997 Measurements of the Thermal Diffusivity of

    E-Print Network [OSTI]

    Mandelis, Andreas

    , transient, and novel hybrid heat-flow methods. In the periodic thermal-wave method, a sample of known

  17. COMBINED THERMAL MEASUREMENT AND SIMULATION FOR THE DETAILED ANALYSIS OF FOUR OCCUPIED LOW-ENERGY BUILDINGS

    E-Print Network [OSTI]

    Gieseler, Udo D. J.

    are equipped with a ventilation system. Ob- jects 3 and 4 are supported by flat-plate thermal solar collectors

  18. Quantitative one-dimensional thermal-wave cavity measurements of fluid thermophysical properties through equivalence studies

    E-Print Network [OSTI]

    Mandelis, Andreas

    of Toronto, Toronto, Ontario M5S3G8, Canada Received 11 April 2006; accepted 13 May 2006; published online 22 due to an intensity modulated pump laser source. The thermal wave inside a sample diffuses over as a thermal-wave generator, and a pyroelectric film placed parallel to the thermal-source surface at a fixed

  19. 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.

  20. High-resolution thermal expansion measurements under helium-gas pressure

    SciTech Connect (OSTI)

    Manna, Rudra Sekhar; Wolf, Bernd; Souza, Mariano de; Lang, Michael

    2012-08-15

    We report on the realization of a capacitive dilatometer, designed for high-resolution measurements of length changes of a material for temperatures 1.4 K Less-Than-Or-Slanted-Equal-To T Less-Than-Or-Slanted-Equal-To 300 K and hydrostatic pressure P Less-Than-Or-Slanted-Equal-To 250 MPa. Helium ({sup 4}He) is used as a pressure-transmitting medium, ensuring hydrostatic-pressure conditions. Special emphasis has been given to guarantee, to a good approximation, constant-pressure conditions during temperature sweeps. The performance of the dilatometer is demonstrated by measurements of the coefficient of thermal expansion at pressures P Asymptotically-Equal-To 0.1 MPa (ambient pressure) and 104 MPa on a single crystal of azurite, Cu{sub 3}(CO{sub 3}){sub 2}(OH){sub 2}, a quasi-one-dimensional spin S = 1/2 Heisenberg antiferromagnet. The results indicate a strong effect of pressure on the magnetic interactions in this system.

  1. Frequency-Dependent Photothermal Measurement of Transverse Thermal Diffusivity of Organic Semiconductors

    E-Print Network [OSTI]

    J. W. Brill; Maryam Shahi; Marcia M. Payne; Jesper Edberg; Y. Yao; Xavier Crispin; J. E. Anthony

    2015-09-08

    We have used a photothermal technique, in which chopped light heats the front surface of a small ( ~ 1 mm2) sample and the chopping frequency dependence of thermal radiation from the back surface is measured with a liquid nitrogen cooled infrared detector. In our system, the sample is placed directly in front of the detector within its dewar. Because the detector is also sensitive to some of the incident light which leaks around or through the sample, measurements are made for the detector signal that is in quadrature with the chopped light. Results are presented for layered crystals of semiconducting 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pn) and for papers of cellulose nanofibrils coated with semiconducting poly(3,4-ethylene-dioxythiophene):poly(styrene-sulfonate) (NFC-PEDOT). For NFC-PEDOT, we have found that the transverse diffusivity, smaller than the in-plane value, varies inversely with thickness, suggesting that texturing of the papers varies with thickness. For TIPS-pn, we have found that the interlayer diffusivity is an order of magnitude larger than the in-plane value, consistent with previous estimates, suggesting that low-frequency optical phonons, presumably associated with librations in the TIPS side-groups, carry most of the heat.

  2. Frequency-Dependent Photothermal Measurement of Transverse Thermal Diffusivity of Organic Semiconductors

    E-Print Network [OSTI]

    J. W. Brill; Maryam Shahi; Marcia M. Payne; Jesper Edberg; Y. Yao; Xavier Crispin; J. E. Anthony

    2015-08-13

    We have used a photothermal technique, in which chopped light heats the front surface of a small ( ~ 1 mm2) sample and the chopping frequency dependence of thermal radiation from the back surface is measured with a liquid nitrogen cooled infrared detector. In our system, the sample is placed directly in front of the detector within its dewar. Because the detector is also sensitive to some of the incident light which leaks around or through the sample, measurements are made for the detector signal that is in quadrature with the chopped light. Results are presented for layered crystals of semiconducting 6,13-bis(triisopropylsilylethynyl) pentacene (TIPS-pn) and for papers of cellulose nanofibrils coated with semiconducting poly(3,4-ethylene-dioxythiophene):poly(styrene-sulfonate) (NFC-PEDOT). For NFC-PEDOT, we have found that the transverse diffusivity, smaller than the in-plane value, varies inversely with thickness, suggesting that texturing of the papers varies with thickness. For TIPS-pn, we have found that the interlayer diffusivity is an order of magnitude larger than the in-plane value, consistent with previous estimates, suggesting that low-frequency optical phonons, presumably associated with librations in the TIPS side-groups, carry most of the heat.

  3. Characterizing eigenstate thermalization via measures in the Fock space of operators

    E-Print Network [OSTI]

    Pavan Hosur; Xiao-Liang Qi

    2015-07-25

    The eigenstate thermalization hypothesis (ETH) attempts to bridge the gap between quantum mechanical and statistical mechanical descriptions of isolated quantum systems. Here, we define unbiased measures for how well the ETH works in various regimes, by mapping general interacting quantum systems on regular lattices onto a single particle living on a high-dimensional graph. By numerically analyzing deviations from ETH behavior in the non-integrable Ising model, we propose a quantity that we call the $n$-$weight$ to democratically characterize the average deviations for all operators residing on a given number of sites, irrespective of their spatial structure. It appears to have a simple scaling form, that we conjecture to hold true for all non-integrable systems. A closely related quantity, that we term the $n$-$distinguishability$, tells us how well two states can be distinguished if only $n$-site operators are measured. Along the way, we discover that complicated operators on average are worse than simple ones at distinguishing between neighboring eigenstates, contrary to the naive intuition created by the usual statements of the ETH that few-body (many-body) operators acquire the same (different) expectation values in nearby eigenstates at finite energy density. Finally, we sketch heuristic arguments that the ETH originates from the limited ability of simple operators to distinguish between quantum states of a system, especially when the states are subject to constraints such as roughly fixed energy with respect to a local Hamiltonian.

  4. Measurements and Standards for Thermoelectric Materials

    E-Print Network [OSTI]

    Measurements and Standards for Thermoelectric Materials CERAMICS Our goal is to develop standard, electrical conductivity, thermal conductivity) for thin film and bulk thermoelectric materials to enable approach will facilitate comparison of thermoelectric data between leading laboratories, and accelerate

  5. MONITORING POWER PLANT EFFICIENCY USING THE MICROWAVE-EXCITED THERMAL-ACOUSTIC EFFECT TO MEASURE UNBURNED CARBON

    SciTech Connect (OSTI)

    Robert C. Brown; Robert J. Weber; Jeffrey J. Swetelitsch

    2005-01-01

    The objective of this project is to explore microwave-excited thermal-acoustic (META) phenomena for quantitative analysis of granular and powdered materials, with the culmination of the research to be an on-line carbon-in-ash monitor for coal-fired power plants. This technique of analyzing unburned carbon in fly ash could be a less tedious and time consuming method as compared to the traditional LOI manual procedure. Phase 1 of the research focused on off-line single-frequency thermal-acoustic measurements where an off-line fly ash monitor was constructed that could operate as analytical tool to explore instrument and methodology parameters for quantifying the microwave-excited thermal-acoustic effect of carbon in fly ash, and it was determined that the off-line thermal-acoustic technique could predict the carbon content of a random collection of fly ashes with a linear correlation constant of R{sup 2} = 0.778. Much higher correlations are expected for fly ashes generated from a single boiler. Phase 2 of the research developing a methodology to generate microwave spectra of various powders, including fly ash, coal, and inorganic minerals, and to determine if these microwave spectra could be used for chemical analyses. Although different minerals produced different responses, higher resolution microwave spectra would be required to be able to distinguish among minerals. Phase 3 of the research focused on the development of an on-line fly ash monitor that could be adapted to measure either a thermal-acoustic or thermal-elastic response to due microwave excitation of fly ash. The thermal-acoustic response was successfully employed for this purpose but the thermal-elastic response was too weak to yield a useful on-line device.

  6. 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

  7. Measuring the Optical Performance of Evacuated Receivers via an Outdoor Thermal Transient Test: Preprint

    SciTech Connect (OSTI)

    Kutscher, C.; Burkholder, F.; Netter, J.

    2011-08-01

    Modern parabolic trough solar collectors operated at high temperatures to provide the heat input to Rankine steam power cycles employ evacuated receiver tubes along the collector focal line. High performance is achieved via the use of a selective surface with a high absorptance for incoming short-wave solar radiation and a low emittance for outgoing long-wave infrared radiation, as well as the use of a hard vacuum to essentially eliminate convective and conductive heat losses. This paper describes a new method that determines receiver overall optical efficiency by exposing a fluid-filled, pre-cooled receiver to one sun outdoors and measuring the slope of the temperature curve at the point where the receiver temperature passes the glass envelope temperature (that is, the point at which there is no heat gain or loss from the absorber). This transient test method offers the potential advantages of simplicity, high accuracy, and the use of the actual solar spectrum.

  8. Carrier dynamics in bulk ZnO. I. Intrinsic conductivity measured by terahertz time-domain spectroscopy

    E-Print Network [OSTI]

    at room temperature.3 Thin films of ZnO are useful in transparent transistors and transparent conducting coatings because of their combination of wide band gap, high conductivity, and processability.4

  9. Ground truth measurements plan for the Multispectral Thermal Imager (MTI) satellite

    SciTech Connect (OSTI)

    Garrett, A.J.

    2000-01-03

    Sandia National Laboratories (SNL), Los Alamos National Laboratory (LANL), and the Savannah River Technology Center (SRTC) have developed a diverse group of algorithms for processing and analyzing the data that will be collected by the Multispectral Thermal Imager (MTI) after launch late in 1999. Each of these algorithms must be verified by comparison to independent surface and atmospheric measurements. SRTC has selected 13 sites in the continental U.S. for ground truth data collections. These sites include a high altitude cold water target (Crater Lake), cooling lakes and towers in the warm, humid southeastern US, Department of Energy (DOE) climate research sites, the NASA Stennis satellite Validation and Verification (V and V) target array, waste sites at the Savannah River Site, mining sites in the Four Corners area and dry lake beds in the southwestern US. SRTC has established mutually beneficial relationships with the organizations that manage these sites to make use of their operating and research data and to install additional instrumentation needed for MTI algorithm V and V.

  10. Measurements of the thermodynamic equation of state via the pressure dependence of thermophysical properties of air by a thermal-wave

    E-Print Network [OSTI]

    Mandelis, Andreas

    of Toronto, 5 King's College Road, Toronto, Ontario M5S 3G8, Canada Received 17 April 1998; accepted, and thermal-wave-source infrared emissivity were measured. The experimental results were found of the resistively heated Cr­Ni thermal-wave thin-film strip source cavity wall was measured as a function

  11. Optical transient grating measurements of micro/nanoscale thermal transport and mechanical properties

    E-Print Network [OSTI]

    Eliason, Jeffrey Kristian

    2015-01-01

    The laser-based transient grating technique was used to study phonon mediated thermal transport in bulk and nanostructured semiconductors and surface wave propagation in a monolayer of micron sized spheres. In the transient ...

  12. Compact and high-particle-flux thermal-lithium-beam probe system for measurement of two-dimensional electron density profile

    SciTech Connect (OSTI)

    Shibata, Y. Manabe, T.; Ohno, N.; Takagi, M.; Kajita, S.; Tsuchiya, H.; Morisaki, T.

    2014-09-15

    A compact and high-particle-flux thermal-lithium-beam source for two-dimensional measurement of electron density profiles has been developed. The thermal-lithium-beam oven is heated by a carbon heater. In this system, the maximum particle flux of the thermal lithium beam was ?4 × 10{sup 19} m{sup ?2} s{sup ?1} when the temperature of the thermal-lithium-beam oven was 900 K. The electron density profile was evaluated in the small tokamak device HYBTOK-II. The electron density profile was reconstructed using the thermal-lithium-beam probe data and this profile was consistent with the electron density profile measured with a Langmuir electrostatic probe. We confirm that the developed thermal-lithium-beam probe can be used to measure the two-dimensional electron density profile with high time and spatial resolutions.

  13. 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....

  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. Thermal imaging measurement of lateral diffusivity and non-invasive material defect detection

    DOE Patents [OSTI]

    Sun, Jiangang (Westmont, IL); Deemer, Chris (Downers Grove, IL)

    2003-01-01

    A system and method for determining lateral thermal diffusivity of a material sample using a heat pulse; a sample oriented within an orthogonal coordinate system; an infrared camera; and a computer that has a digital frame grabber, and data acquisition and processing software. The mathematical model used within the data processing software is capable of determining the lateral thermal diffusivity of a sample of finite boundaries. The system and method may also be used as a nondestructive method for detecting and locating cracks within the material sample.

  16. The material dependence of temperature measurement resolution in thermal scanning electron microscopy

    SciTech Connect (OSTI)

    Wu, Xiaowei; Hull, Robert [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180 (United States)] [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, 110 8th Street, Troy, New York 12180 (United States)

    2013-03-18

    Thermal scanning electron microscopy is a recently developed temperature mapping technique based on thermal diffuse scattering in electron backscatter diffraction in a scanning electron microscope. It provides nano-scale and non-contact temperature mapping capabilities. Due to the specific temperature sensitive mechanism inherent to this technique, the temperature resolution is highly material dependent. A thorough investigation of what material properties affect the temperature resolution is important for realizing the inherent temperature resolution limit for each material. In this paper, three material dependent parameters-the Debye-Waller B-factor temperature sensitivity, backscatter yield, and lattice constant-are shown to control the temperature resolution.

  17. Numerical method for calculating the apparent eddy current conductivity loss on randomly rough surfaces

    E-Print Network [OSTI]

    Nagy, Peter B.

    Numerical method for calculating the apparent eddy current conductivity loss on randomly rough Because of their frequency-dependent penetration depth, eddy current measurements are capable of mapping of eddy current conductivity, thereby decreasing the accuracy of the measurements, especially in thermally

  18. 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.

  19. ELSEVIER Journal of Nuclear Materials 239 (1996) 245-252 In situ measurement of electrical conductivity of alumina under

    E-Print Network [OSTI]

    Howlader, Matiar R

    1996-01-01

    the effects of flux, electric field and temperature and may lessen their performance in fusion reactors affect the performance of ct-A1203 in fusion reactors. A significant surface conductivity is confirmed, it is emphasized that RIC and RIED of et-A1203 are not severe for insulators in the International Thermonuclear

  20. Measurement of thermal noise in multilayer coatings with optimized layer thickness Akira E. Villar, Eric D. Black, Riccardo DeSalvo, and Kenneth G. Libbrecht

    E-Print Network [OSTI]

    Libbrecht, Kenneth G.

    Measurement of thermal noise in multilayer coatings with optimized layer thickness Akira E. Villar; published 3 June 2010) A standard quarter-wavelength multilayer optical coating will produce the highest reflectivity for a given number of coating layers, but in general it will not yield the lowest thermal noise

  1. 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}.

  2. Nuclear Instruments and Methods in Physics Research A 432 (1999) 403}409 Measurement of the thermal and fast neutron #ux in a research

    E-Print Network [OSTI]

    Pázsit, Imre

    1999-01-01

    the neutron converter material to measure neu- trons of various energies, such as fast, thermal and epithermal positions, such as between the fuel plates of an MTR-type reactor. At the same time, its sensitive volume

  3. Measured thermal and fast neutron fluence rates, ATR Cycle 100-BC, April 23, 1993--May 13, 1993

    SciTech Connect (OSTI)

    Smith, L.D.; Murray, R.K.; Rogers, J.W.

    1993-07-01

    This report contains the thermal (2200 m/s) and fast (E>1MeV) neutron fluence rate data for ATR Cycle 100-BC which were measured by the Radiation Measurements Laboratory (RML) as requested by the Power Reactor Programs (ATR Experiments) Radiation Measurements Work Order. This report contains fluence rate values corresponding to the particular elevations (relative to the 80 ft. core elevation) where the measurements were taken. The data in this report consists of (1) a table of the ATR power history and distribution, (2) a hard copy listing of all thermal and fast neutron fluence rates, (3) plots of both the thermal and fast neutron fluence rates, and (4) a magnetic record (3.5 inch diskette) containing a listing of only the fast neutron fluence rates, their assigned elevations and proper header identification of all monitor positions contained herein. The fluence rates reported are for the average power levels given in the table of power history and distribution. All {open_quotes}H{close_quotes} holder monitor wires for this cycle are 54 inches long. All {open_quotes}SR{close_quotes} holder monitor wires for this cycle are 55 inches long. This length allows measurement of the full core region and makes the first count elevation 24.73 inches above core midplane. Due to the safety rod problems in the west lobe, {open_quotes}BR{close_quotes} holders were used in the W-1, 2, 3, and 4 positions. All {open_quotes}BR{close_quotes} holder monitor wires for this cycle are 56.25 inches long. The distance from the end of the wires to the first count position was 4.25 inches for all wires counted from this cycle. The results from the measurements in the W-1, 2, 3, 4 monitor positions indicate that the safety rod followers were rotated to a different azimuthal orientation relative to the normal orientation. The results indicate that the rotation was counterclockwise from their normal orientation. This is the same condition observed starting with Cycle 99-B.

  4. Photo-Thermal Transfer Function of Dielectric Mirrors for Precision Measurements

    E-Print Network [OSTI]

    Stefan W. Ballmer

    2015-01-07

    The photo-thermal transfer function from absorbed power incident on a dielectric mirror to the effective mirror position is calculated using the coating design as input. The effect is found to change in amplitude and sign for frequencies corresponding to diffusion length comparable to the coating thickness. Transfer functions are calculated for the $Ti$-doped ${\\rm Ta_2O_5:SiO_2}$ coating used in Advanced LIGO and for a crystalline ${\\rm Al_xGa_{1-x}As}$ coating. The shape of the transfer function at high frequencies is shown to be a sensitive indicator of the effective absorption depth, providing a potentially powerful tool to distinguish coating-internal absorption from surface contamination related absorption. The sign change of the photo-thermal effect could also be useful to stabilize radiation pressure-based opto-mechanical systems. High frequency corrections to the previously published thermo-optic noise estimates are also provided. Finally, estimating the quality of the thermo-optic noise cancellation occurring in fine-tuned ${\\rm Al_xGa_{1-x}As}$ coatings requires the detailed heat flow analysis done in this paper.

  5. Measurements of the spatial and energy distribution of thermal neutrons in uranium, heavy water lattices

    E-Print Network [OSTI]

    Brown, Paul S. (Paul Sherman)

    1962-01-01

    Intracell activity distributions were measured in three natural uranium, heavy water lattices of 1. 010 inch diameter, aluminum clad rods on triangular spacings of 4. 5 inches, 5. 0 inches, and 5. 75 inches, respectively, ...

  6. Building design and thermal renovation measures proposal by means of regression models issued from dynamic simulations

    E-Print Network [OSTI]

    Boyer, Edmond

    using their positions to exert political pressure" , "inadequate energy efficiency measures in Europe and China (and about 30­40% world-wide) [2]. Most of this energy is for supplying the energy for lighting comparison between different energy reduction strategies, like improving the insulation levels or increasing

  7. American Institute of Aeronautics and Astronautics Measurements for fuel reforming for scramjet thermal management and

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    American Institute of Aeronautics and Astronautics 1 Measurements for fuel reforming for scramjet. Different cooling strategies have been evaluated by MBDA-France (calculations, material tests). Metallic. The time allocated to mix the injected fuel with inlet air, to ignite the combustion and to complete

  8. LDRD final report on polyphosphaacetylenes, new hybrid conducting organic-inorganic materials

    SciTech Connect (OSTI)

    Jamison, G.M.; Loy, D.A.; Saunders, R.S.; Alam, T.M.

    1996-06-01

    Thermal, electrochemical and transition metal mediated reactions of phosphaacetylene monomers were conducted in attempts to form novel polyphosphaacetylenes as a new class of potentially electrically conducting polymers. Molecular modeling was used to simulate the molecular conformations of optimized, isolated oligomers to identify the proper monomeric repeat units for highly conjugated molecules. Electrodeposition of suitable monomers led to low molecular weight oligomers. Thermal polymerization of phosphaacetylene monomers bearing aromatic substituents ed to the formation of polyhedral cage oligomers. Under metathesis polymerization conditions the phosphaacetylene monomers form unique complexes via an unprecedented sequence of intermediates which suggest that metathesis to linear oligomers is achievable. Conductivity measurements on electrodeposited oligomers indicate modest electrical conductivity.

  9. Field-measured performance of four full-scale cylindrical stratified chilled-water thermal storage tanks

    SciTech Connect (OSTI)

    Musser, A.; Bahnfleth, W.P.

    1999-07-01

    Results are presented for controlled flow rate tests in four full-scale cylindrical chilled-water storage tanks. The tanks range in volume from 1.15 to 5.18 million gallons (4.35 to 19.61 million liters) and have water depths of 40 to 65 ft (12.2 to 19.8 m). Water is introduced into and withdrawn from two of these tanks using radial parallel plate diffusers, while the remaining two tanks utilize octagonal slotted pipe diffuser designs. Thermal performance is quantified for full cycles in terms of Figure of Merit, for single charge and discharge processes as half-cycle Figure of Merit, and for incomplete charge and discharge processes as Lost Capacity. Results show that the thermal performance of all four tanks is excellent, with less than 4% of theoretical cooling capacity lost to inlet mixing and other degradation mechanisms for flow rates less than or equal to design. Based on these results, the appropriateness of current design guidance is discussed. Operational issues that affect implementation of controlled flow rate full-scale tests are also identified, and measurement issues are addressed.

  10. Measurement of molecular motion in organic semiconductors by thermal diffuse electron scattering

    E-Print Network [OSTI]

    Eggeman, Alexander S.; Illig, Steffen; Troisi, Alessandro; Sirringhaus, Henning; Midgley, Paul A.

    2013-07-28

    be accessed at: Nature Materials 12, 1045-1049 (2013) http://www.nature.com/doifinder/10.1038/nmat3710 1 Title: Direct Measurement of Molecular Motion in Organic Semiconductors Authors: Alexander S. Eggeman,1? Steffen Illig,2? Alessandro Troisi,3 Henning... . 220, 1027 (2005). 11. D. C. M. Jihua Chen, J. E. Anthony, Journal of Materials Research pp. 1701 – 1709 (2007). 12. F. Banhart, Reports on Progress in Physics 62, 1181 (1999). 13. R. F. Loane, P. Xu, J. Silcox, Acta Crystallographica Section A 47, 267...

  11. Thermal input control and enhancement for laser based residual stress measurements using liquid temperature indicating coatings

    DOE Patents [OSTI]

    Pechersky, M.J.

    1999-07-06

    An improved method for measuring residual stress in a material is disclosed comprising the steps of applying a spot of temperature indicating coating to the surface to be studied, establishing a speckle pattern surrounds the spot of coating with a first laser then heating the spot of coating with a far infrared laser until the surface plastically deforms. Comparing the speckle patterns before and after deformation by subtracting one pattern from the other will produce a fringe pattern that serves as a visual and quantitative indication of the degree to which the plasticized surface responded to the stress during heating and enables calculation of the stress. 3 figs.

  12. Measurement and modeling of thermal properties of sorghum and soy flours 

    E-Print Network [OSTI]

    Gonzalez Palacios, Lazaro

    1981-01-01

    transfer to or from the sample. Figure 2 (which will be explained in detail later) shows some typical Fusion trask HEAT slOW l RATE col/ sec 0 starling Transient lsotherma Grass Transition Crystal li sation Prrak Eras ne Transient Isothermal...H) required for this transition was measured by integrating the area under the peak with a planimeter and comparing it to the area obtained from a known transit1on of a standard. The standard used was indium which has a melting transition (see fusion peak...

  13. Thermal input control and enhancement for laser based residual stress measurements using liquid temperature indicating coatings

    DOE Patents [OSTI]

    Pechersky, Martin J. (Aiken, SC)

    1999-01-01

    An improved method for measuring residual stress in a material comprising the steps of applying a spot of temperature indicating coating to the surface to be studied, establishing a speckle pattern surrounds the spot of coating with a first laser then heating the spot of coating with a far infrared laser until the surface plastically deforms. Comparing the speckle patterns before and after deformation by subtracting one pattern from the other will produce a fringe pattern that serves as a visual and quantitative indication of the degree to which the plasticized surface responded to the stress during heating and enables calculation of the stress.

  14. Measurements of the Radiated Fields and Conducted Current Leakage from the Pulsed Power Systems in the National Ignition Facility at LLNL

    SciTech Connect (OSTI)

    Anderson, R A; Clancy, T J; Fulkerson, S; Petersen, D; Pendelton, D; Hulsey, S; Ullery, G; Tuck, J; Polk, M; Kamm, R; Newton, M; Moore, W B; Arnold, P; Ollis, C; Hinz, A; Robb, C; Fornes, J; Watson, J

    2003-07-31

    An important pulsed power system consideration is that they inherently generate fields and currents that can cause interference in other subsystems and diagnostics. Good pulsed power design, grounding and isolation practices can help mitigate these unwanted signals. During the laser commissioning shots for the NIF Early Light milestone at LLNL, measurements were made of the radiated field and conducted currents caused by the Power Conditioning System (PCS) modules with flash lamp load and the Plasma Electrode Pockels Cell (PEPC) driver. The measurements were made in the capacitor bay, laser bay, control room and target bay. The field measurements were made with B-dot and E-dot probes with bandwidth of about 100MHz. The current measurements were made with a clamp on probe with a bandwidth of about 20 MHz. The results of these measurements show fields and currents in the NIF Facility well below that required for interference with other subsystems. Currents on the target chamber from the pulsed power systems are well below the background noise currents.

  15. Measurement of plutonium and americium volatilities under thermal process conditions. Final report

    SciTech Connect (OSTI)

    Krikorian, O.H.; Condit, R.H.; Fontes, A.S. Jr.; Fleming, D.L.; Magana, J.W.; Morris, W.F.; Adamson, M.G.

    1993-04-28

    We have used the transpiration method to measure volatilities of Pu and Am from PuO{sub 2}(s) and PuO{sub 2}/2% AmO{sub 2}(s) in the presence of steam and oxygen at temperatures of 1230--1430 K. We find the volatile species to be PuO{sub 2}(OH){sub 2}(g) and AmO{sub 2}(OH){sub 2}(g) at vapor pressures on the order of 10{sup {minus}10} atm and 10 {sup {minus}12} atm respectively under measurement conditions. For the Pu volatilization reaction, PuO{sub 2}(s) + 1/2 0{sub 2}(9) + H{sub 2}0(g) = PuO{sub 2}(OH){sub 2}(g), we obtain a free energy of reaction of {Delta}G{sup O}{sub T} = 231.3--0.0109 T in kj/mol, and for the Am volatilization reaction, AmO{sub 2}(s.s. in PuO{sub 2}) + 1/2 0{sub 2}(9) + H{sub 2}0(g) = AmO{sub 2}(OH){sub 2}(g), we obtain AG{sup O}{sub T} = 223.9--0.0109 T in kj/mol. We apply these results to the Rocky Flats Plant Fluidized Bed Incinerator to assess the amount of volatile Pu and Am produced in the secondary combustor chamber. Taking operating conditions of 550C combustor temperature, 40 kmols/h of total gas flow at 1 atm pressure, 0.1 atm 0{sub 2}(9), 0.05 atm H{sub 2}0(g), PuO{sub 2} (s) containing 200 ppm AmO{sub 2} in the bed, and 6000 h of operating time per year, gives volatilization rates of 7 {times} 10 {sup {minus}6}g Pu and 4 {times} 10 {sup {minus}9}g Am/y.

  16. Evaluation of the thermal resistance of a roof-mounted multi-reflective radiant barrier for tropical and humid conditions: Experimental study from field measurements

    E-Print Network [OSTI]

    Miranville, Frédéric; Guichard, Stéphane; Boyer, Harry; Praene, Jean Philippe; Bigot, Dimitri

    2012-01-01

    This paper deals with the experimental evaluation of a roof-mounted multi-reflective radiant barrier (MRRB), installed according to the state of the art, on a dedicated test cell. An existing experimental device was completed with a specific system for the regulation of the airflow rate in the upper air layer included in a typical roof from Reunion Island. Several experimental sequences were conducted to determine the thermal resistance of the roof according to several parameters and following a specific method. The mean method, well known in international standards (ISO 9869 - 1994) for the determination of the thermal resistance using dynamic data, was used. The method was implemented in a building simulation code in order to allow the determination of the thermal indicator automatically. Experimental results are proposed according to different seasonal periods and for different values of the airflow rate in the upper air layer

  17. Evaluation of the thermal resistance of a roof-mounted multi-reflective radiant barrier for tropical and humid conditions: Experimental study from field measurements

    E-Print Network [OSTI]

    Frédéric Miranville; Ali Hamada Fakra; Stéphane Guichard; Harry Boyer; Jean Philippe Praene; Dimitri Bigot

    2012-12-19

    This paper deals with the experimental evaluation of a roof-mounted multi-reflective radiant barrier (MRRB), installed according to the state of the art, on a dedicated test cell. An existing experimental device was completed with a specific system for the regulation of the airflow rate in the upper air layer included in a typical roof from Reunion Island. Several experimental sequences were conducted to determine the thermal resistance of the roof according to several parameters and following a specific method. The mean method, well known in international standards (ISO 9869 - 1994) for the determination of the thermal resistance using dynamic data, was used. The method was implemented in a building simulation code in order to allow the determination of the thermal indicator automatically. Experimental results are proposed according to different seasonal periods and for different values of the airflow rate in the upper air layer.

  18. 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

  19. Investigation of Thermal Interface Materials Using Phase-Sensitive Transient Thermoreflectance Technique: Preprint

    SciTech Connect (OSTI)

    Feng, X.; King, C.; DeVoto, D.; Mihalic, M.; Narumanchi, S.

    2014-08-01

    With increasing power density in electronics packages/modules, thermal resistances at multiple interfaces are a bottleneck to efficient heat removal from the package. In this work, the performance of thermal interface materials such as grease, thermoplastic adhesives and diffusion-bonded interfaces are characterized using the phase-sensitive transient thermoreflectance technique. A multi-layer heat conduction model was constructed and theoretical solutions were derived to obtain the relation between phase lag and the thermal/physical properties. This technique enables simultaneous extraction of the contact resistance and bulk thermal conductivity of the TIMs. With the measurements, the bulk thermal conductivity of Dow TC-5022 thermal grease (70 to 75 um bondline thickness) was 3 to 5 W/(m-K) and the contact resistance was 5 to 10 mm2-K/W. For the Btech thermoplastic material (45 to 80 ?m bondline thickness), the bulk thermal conductivity was 20 to 50 W/(m-K) and the contact resistance was 2 to 5 mm2-K/W. Measurements were also conducted to quantify the thermal performance of diffusion-bonded interface for power electronics applications. Results with the diffusion-bonded sample showed that the interfacial thermal resistance is more than one order of magnitude lower than those of traditional TIMs, suggesting potential pathways to efficient thermal management.

  20. Evolving opportunities for providing thermal comfort

    E-Print Network [OSTI]

    Brager, Gail; Zhang, Hui; Arens, Edward

    2015-01-01

    field measurement of thermal environment and questionnaireand non-uniform thermal environments, PhD Thesis, Center forPerception of transient thermal environments: Pleasure and

  1. 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.

  2. Measurements of thermal transport in low stress silicon nitride films W. Holmes, a) J. M. Gildemeister, and P. L. Richards b)

    E-Print Network [OSTI]

    Richards, Paul L.

    Measurements of thermal transport in low stress silicon nitride films W. Holmes, a) J. M. Gildemeister, and P. L. Richards b) Physics Department, University of California, Berkeley, California 94720 and Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720 V. Kotsubo c

  3. Non-contact, Wavelet-based Measurement of Vital Signs using Thermal Imaging S. Yu. Chekmenev, H. Rara, and Aly A. Farag

    E-Print Network [OSTI]

    Louisville, University of

    Non-contact, Wavelet-based Measurement of Vital Signs using Thermal Imaging S. Yu. Chekmenev, H of human vital signs. Breathing causes noticeable changes in temperature at the nasal area, which appear-contact vital signs monitoring and intent identification at a distance. Keywords: Wavelets, Thermogram images

  4. 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.

  5. Advancing reactive tracer methods for measuring thermal evolution in CO2-and water-based geothermal reservoirs

    Broader source: Energy.gov [DOE]

    DOE Geothermal Peer Review 2010 - Presentation. This project aims to develop reactive tracer method for monitoring thermal drawdown in enhanced geothermal systems.

  6. 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.

  7. Electrical and thermal properties of graphite/polyaniline composites

    SciTech Connect (OSTI)

    Bourdo, Shawn E., E-mail: sxbourdo@ualr.edu [Center for Integrative Nanotechnology Sciences, University of Arkansas at Little Rock, 2801 South University Avenue, Little Rock, AR 72204 (United States); Warford, Brock A.; Viswanathan, Tito [Department of Chemistry, University of Arkansas at Little Rock, 2801 South University Avenue, Little Rock, AR 72204 (United States)] [Department of Chemistry, University of Arkansas at Little Rock, 2801 South University Avenue, Little Rock, AR 72204 (United States)

    2012-12-15

    A composite of a carbon allotrope (graphite) and an inherently conducting polymer, polyaniline (PANI), has been prepared that exhibits an electrical conductivity greater than either of the two components. An almost 2-fold increase in the bulk conductivity occurs when only a small mass fraction of polyaniline exists in the composite (91% graphite/ 9% polyaniline, by mass). This increase in dc electrical conductivity is curious since in most cases a composite material will exhibit a conductivity somewhere between the two individual components, unless a modification to the electronic nature of the material occurs. In order to elucidate the fundamental electrical properties of the composite we have performed variable temperature conductivity measurements to better understand the nature of conduction in these materials. The results from these studies suggest a change in the mechanism of conduction as the amount of polyaniline is increased in the composite. Along with superior electrical properties, the composites exhibit an increase in thermal stability as compared to the graphite. - Graphical abstract: (Left) Room temperature electrical conductivity of G-PANI composites at different mass ratios. (Right) Electrical conductivity of G-PANI composites at temperatures from 5 K to 300 K. Highlights: Black-Right-Pointing-Pointer Composites of graphite and polyaniline have been synthesized with unique electrical and thermal properties. Black-Right-Pointing-Pointer Certain G-PANI composites are more conductive and more thermally stable than graphite alone. Black-Right-Pointing-Pointer G-PANI composites exhibit a larger conductivity ratio with respect to temperature than graphite alone.

  8. 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...

  9. 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

  10. 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

  11. 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. ,

  12. 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

  13. 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.

  14. Thermal imaging diagnostics of high-current electron beams

    SciTech Connect (OSTI)

    Pushkarev, A.; Kholodnaya, G.; Sazonov, R.; Ponomarev, D. [Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation)

    2012-10-15

    The thermal imaging diagnostics of measuring pulsed electron beam energy density is presented. It provides control of the electron energy spectrum and a measure of the density distribution of the electron beam cross section, the spatial distribution of electrons with energies in the selected range, and the total energy of the electron beam. The diagnostics is based on the thermal imager registration of the imaging electron beam thermal print in a material with low bulk density and low thermal conductivity. Testing of the thermal imaging diagnostics has been conducted on a pulsed electron accelerator TEU-500. The energy of the electrons was 300-500 keV, the density of the electron current was 0.1-0.4 kA/cm{sup 2}, the duration of the pulse (at half-height) was 60 ns, and the energy in the pulse was up to 100 J. To register the thermal print, a thermal imager Fluke-Ti10 was used. Testing showed that the sensitivity of a typical thermal imager provides the registration of a pulsed electron beam heat pattern within one pulse with energy density over 0.1 J/cm{sup 2} (or with current density over 10 A/cm{sup 2}, pulse duration of 60 ns and electron energy of 400 keV) with the spatial resolution of 0.9-1 mm. In contrast to the method of using radiosensitive (dosimetric) materials, thermal imaging diagnostics does not require either expensive consumables, or plenty of processing time.

  15. Note: A simple model for thermal management in solenoids

    SciTech Connect (OSTI)

    McIntosh, E. M. Ellis, J.

    2013-11-15

    We describe a model of the dynamical temperature evolution in a solenoid winding. A simple finite element analysis is calibrated by accurately measuring the thermally induced resistance change of the solenoid, thus obviating the need for accurate knowledge of the mean thermal conductivity of the windings. The model predicts quasi thermal runaway for relatively modest current increases from the normal operating conditions. We demonstrate the application of this model to determine the maximum current that can be safely applied to solenoids used for helium spin-echo measurements.

  16. 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.

  17. 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

  18. 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)

  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 neutron detection system

    DOE Patents [OSTI]

    Peurrung, Anthony J. (Richland, WA); Stromswold, David C. (West Richland, WA)

    2000-01-01

    According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

  1. 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.

  2. 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.

  3. 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.

  4. An in-line thermal-neutron coincidence counter for WIPP (Waste Isolation Pilot Plant) certification measurements

    SciTech Connect (OSTI)

    Krick, M.S.; Osborne, L.; Polk, P.J.; Atencio, J.D.; Bjork, C.

    1989-10-01

    A custom-designed, in-line, thermal-neutron coincidence counter has been constructed for the certification of plutonium waste intended for storage at the Waste Isolation Pilot Plant. The mechanical and electrical components of the system and its performance characteristics are described. 6 refs., 16 figs.

  5. Fission Product Data Measured at Los Alamos for Fission Spectrum and Thermal Neutrons on {sup 239}Pu, {sup 235}U, {sup 238}U

    SciTech Connect (OSTI)

    Selby, H.D.; Mac Innes, M.R.; Barr, D.W.; Keksis, A.L.; Meade, R.A.; Burns, C.J.; Chadwick, M.B.; Wallstrom, T.C.

    2010-12-15

    We describe measurements of fission product data at Los Alamos that are important for determining the number of fissions that have occurred when neutrons are incident on plutonium and uranium isotopes. The fission-spectrum measurements were made using a fission chamber designed by the National Institute for Standards and Technology (NIST) in the BIG TEN critical assembly, as part of the Inter-laboratory Liquid Metal Fast Breeder Reactor (LMFBR) Reaction Rate (ILRR) collaboration. The thermal measurements were made at Los Alamos' Omega West Reactor. A related set of measurements were made of fission-product ratios (so-called R-values) in neutron environments provided by a number of Los Alamos critical assemblies that range from having average energies causing fission of 400-600 keV (BIG TEN and the outer regions of the Flattop-25 assembly) to higher energies (1.4-1.9 MeV) in the Jezebel, and in the central regions of the Flattop-25 and Flattop-Pu, critical assemblies. From these data we determine ratios of fission product yields in different fuel and neutron environments (Q-values) and fission product yields in fission spectrum neutron environments for {sup 99}Mo, {sup 95}Zr, {sup 137}Cs, {sup 140}Ba, {sup 141,143}Ce, and {sup 147}Nd. Modest incident-energy dependence exists for the {sup 147}Nd fission product yield; this is discussed in the context of models for fission that include thermal and dynamical effects. The fission product data agree with measurements by Maeck and other authors using mass-spectrometry methods, and with the ILRR collaboration results that used gamma spectroscopy for quantifying fission products. We note that the measurements also contradict earlier 1950s historical Los Alamos estimates by {approx}5-7%, most likely owing to self-shielding corrections not made in the early thermal measurements. Our experimental results provide a confirmation of the England-Rider ENDF/B-VI evaluated fission-spectrum fission product yields that were carried over to the ENDF/B-VII.0 library, except for {sup 99}Mo where the present results are about 4%-relative higher for neutrons incident on {sup 239}Pu and {sup 235}U. Additionally, our results illustrate the importance of representing the incident energy dependence of fission product yields over the fast neutron energy range for high-accuracy work, for example the {sup 147}Nd from neutron reactions on plutonium. An upgrade to the ENDF library, for ENDF/B-VII.1, based on these and other data, is described in a companion paper to this work.

  6. The thermal performance of steel-framed walls

    SciTech Connect (OSTI)

    Barbour, C.E. [NAHB Research Center, Upper Marlboro, MD (United States). Building Systems Div.; Goodrow, J. [Holometrix, Bedford, MA (United States)

    1995-12-31

    Thermal bridges are areas in constructions that have highly conductive materials, allowing higher heat transfer through less conductive areas. In a wall, thermal bridges can increase heat loss, cause dust to accumulate on the studs (ghosting) due to temperature distribution, and cause condensation to form in and on the walls. The effects of thermal bridges are often misunderstood by engineers, buildings, and manufacturers of construction products. This study attempts to provide a better understanding of the effects of thermal bridges in steel-framed walls, as well as information leading to improved methods of predicting R-value of walls containing thermal bridges. An improved method for estimating R-value would allow an equitable comparison of thermal performance with other construction types and materials. This would increase the number of alternative materials for walls available to designers, thus allowing them the freedom to correctly choose the optimum choice for construction. In order to arrive at an improved method, experimental data on the heat transfer characteristics of steel-framed walls were collected. Twenty-three wall samples were tested in a calibrated hot box (ASTM C976) to measure the thermal performance of steel-framed wall systems. The tests included an array of stud frame configurations, exterior sheathing, and fiberglass batt insulations. Other studies of thermal bridging in steel-framed walls have not included the use of insulating sheathing, which reduces the extent of the thermal bridges and improves total thermal performance. The purpose of the project was to provide measured R-values for commonly used steel-framed wall configurations and to improve R-value estimating methods. Also, detailed monitoring of temperature gradients in the test walls combined with numerical analysis provided new insights into heat transfer phenomena concerning thermal bridges.

  7. 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...

  8. 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

  9. 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...

  10. Development of a compact thermal lithium atom beam source for measurements of electron velocity distribution function anisotropy in electron cyclotron resonance plasmas

    SciTech Connect (OSTI)

    Nishioka, T.; Shikama, T.; Nagamizo, S.; Fujii, K.; Hasuo, M. [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 615-8540 (Japan)] [Department of Mechanical Engineering and Science, Graduate School of Engineering, Kyoto University, Kyoto 615-8540 (Japan); Zushi, H. [Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580 (Japan)] [Research Institute for Applied Mechanics, Kyushu University, Fukuoka 816-8580 (Japan); Uchida, M.; Tanaka, H.; Maekawa, T. [Department of Fundamental Energy Science, Graduate School of Energy Science, Kyoto University, Kyoto 606-8502 (Japan)] [Department of Fundamental Energy Science, Graduate School of Energy Science, Kyoto University, Kyoto 606-8502 (Japan); Iwamae, A. [Research Center for Development of Far-Infrared Region, Fukui University, Fukui 910-8507 (Japan)] [Research Center for Development of Far-Infrared Region, Fukui University, Fukui 910-8507 (Japan)

    2013-07-15

    The anisotropy of the electron velocity distribution function (EVDF) in plasmas can be deduced from the polarization of emissions induced by anisotropic electron-impact excitation. In this paper, we develop a compact thermal lithium atom beam source for spatially resolved measurements of the EVDF anisotropy in electron cyclotron resonance (ECR) plasmas. The beam system is designed such that the ejected beam has a slab shape, and the beam direction is variable. The divergence and flux of the beam are evaluated by experiments and calculations. The developed beam system is installed in an ECR plasma device with a cusp magnetic field, and the LiI 2s–2p emission (670.8 nm) is observed in low-pressure helium plasma. The two-dimensional distributions of the degree and direction of the polarization in the LiI emission are measured by a polarization imaging system. The evaluated polarization distribution suggests the spatial variation of the EVDF anisotropy.

  11. Thermoelectric measurement equipments This instrument is designed for simultaneous measurement of Seebeck coefficient and

    E-Print Network [OSTI]

    Taya, Minoru

    measurement of Seebeck coefficient and electric conductivity for the evaluation of thermoelectric electromotive force. · Employment of an infrared gold image heating furnace that excels in temperature.1 msec/0.3 msec or less Sensor Thermocouple Thermocouple, IR detector Measurement Thermal diffusivity

  12. Transition Region Emission and Energy Input to Thermal Plasma During the Impulsive Phase of Solar Flares

    E-Print Network [OSTI]

    J. C. Raymond; G. Holman; A. Ciaravella; A. Panasyuk; Y. -K. Ko; J. Kohl

    2007-01-12

    The energy released in a solar flare is partitioned between thermal and non-thermal particle energy and lost to thermal conduction and radiation over a broad range of wavelengths. It is difficult to determine the conductive losses and the energy radiated at transition region temperatures during the impulsive phases of flares. We use UVCS measurements of O VI photons produced by 5 flares and subsequently scattered by O VI ions in the corona to determine the 5.0 thermal energy and the conductive losses deduced from RHESSI and GOES X-ray data using areas from RHESSI images to estimate the loop volumes, cross-sectional areas and scale lengths. The transition region luminosities during the impulsive phase exceed the X-ray luminosities for the first few minutes, but they are smaller than the rates of increase of thermal energy unless the filling factor of the X-ray emitting gas is ~ 0.01. The estimated conductive losses from the hot gas are too large to be balanced by radiative losses or heating of evaporated plasma, and we conclude that the area of the flare magnetic flux tubes is much smaller than the effective area measured by RHESSI during this phase of the flares. For the 2002 July 23 flare, the energy deposited by non-thermal particles exceeds the X-ray and UV energy losses and the rate of increase of the thermal energy.

  13. A Combined Near-field Scanning Microwave Microscope and Transport Measurement System for Characterizing Dissipation in Conducting and High-Tc Superconducting Films at Variable Temperature

    E-Print Network [OSTI]

    Dizon, Jonathan Reyes

    2009-04-28

    , on the other hand, focused early efforts on using their coaxial resonator-type probe to image a sample?s ferroelectric domains by measuring the variations in the dielectric constant [Gao 1998]. Periodic ferroelectric domain structures in crystals have found..., on the other hand, focused early efforts on using their coaxial resonator-type probe to image a sample?s ferroelectric domains by measuring the variations in the dielectric constant [Gao 1998]. Periodic ferroelectric domain structures in crystals have found...

  14. Method for ultra-trace cesium isotope ratio measurements from environmental samples using thermal ionization mass spectrometry

    SciTech Connect (OSTI)

    Snow, Mathew S.; Snyder, Darin C.; Mann, Nick R.; White, Byron M.

    2015-05-01

    135Cs/137Cs isotope ratios can provide the age, origin and history of environmental Cs contamination. Relatively high precision 135Cs/137Cs isotope ratio measurements from samples containing femtogram quantities of 137Cs are needed to accurately track contamination resuspension and redistribution following environmental 137Cs releases; however, mass spectrometric analyses of environmental samples are limited by the large quantities of ionization inhibitors and isobaric interferences which are present at relatively high concentrations in the environment. We report a new approach for Cs purification from environmental samples. An initial ammonium molybdophosphate-polyacrylonitrile (AMP-PAN) column provides a robust method for extracting Cs under a wide variety of sample matrices and mass loads. Cation exchange separations using a second AMP-PAN column result in more than two orders of magnitude greater Cs/Rb separation factors than commercially available strong cation exchangers. Coupling an AMP-PAN cation exchanging step to a microcation column (AG50W resin) enables consistent 2-4% (2?) measurement errors for samples containing 3-6,000 fg 137Cs, representing the highest precision 135Cs/137Cs ratio measurements currently reported for soil samples at the femtogram level.

  15. 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.

  16. 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.

  17. Improvement in Thermal-Ionization Mass Spectrometry (TIMS) using Total Flash Evaporation (TFE) method for lanthanides isotope ratio measurements in transmutation targets

    SciTech Connect (OSTI)

    Mialle, S.; Gourgiotis, A.; Aubert, M.; Stadelmann, G.; Gautier, C.; Isnard, H.

    2011-07-01

    The experiments involved in the PHENIX french nuclear reactor to obtain precise and accurate data on the total capture cross sections of the heavy isotopes and fission products require isotopic ratios measurements with uncertainty of a few per mil. These accurate isotopic ratio measurements are performed with mass spectrometer equipped with multi-collector system. The major difficulty for the analyses of these actinides and fission products is the low quantity of the initial powder enclosed in steel container (3 to 5 mg) and the very low quantities of products formed (several {mu}g) after irradiation. Specific analytical developments are performed by Thermal Ionization Mass Spectrometry (TIMS) to be able to analyse several nanograms of elements with this technique. A specific method of acquisition named Total Flash Evaporation was adapted in this study in the case of lanthanide measurements for quantity deposited on the filament in the order of 2 ng and applied on irradiated fuel. To validate the analytical approach and discuss about the accuracy of the data, the isotopic ratios obtained by TIMS are compared with other mass spectrometric techniques such as Multiple-Collector Inductively Coupled Plasma Mass Spectrometer (MC-ICPMS). (authors)

  18. Thermal performance of steel-framed walls. Final report

    SciTech Connect (OSTI)

    Barbour, E. [NAHB Research Center, Inc., Upper Marlboro, MD (United States); Goodrow, J. [Holometrix, Inc., Bedford, MA (United States); Kosny, J.; Christian, J.E. [Oak Ridge National Lab., TN (United States)

    1994-11-21

    In wall construction, highly conductive members spaced along the wall, which allow higher heat transfer than that through less conductive areas, are referred to as thermal bridges. Thermal bridges in walls tend to increase heat loss and, under certain adverse conditions, can cause dust streaking (``ghosting``) on interior walls over studs due to temperature differentials, as well as condensation in and on walls. Although such adverse conditions can be easily avoided by proper thermal design of wall systems, these effects have not been well understood and thermal data has been lacking. Therefore, the present study was initiated to provide (1) a better understanding of the thermal behavior of steel-framed walls, (2) a set of R-values for typical wall constructions, and (3) information that could be used to develop improved methods of predicting R-values. An improved method for estimating R-value would allow an equitable comparison of thermal performance with other construction types and materials. This would increase the number of alternative materials for walls available to designers, thus allowing them to choose the optimum choice for construction. Twenty-three wall samples were tested in a calibrated hot box (ASTM C9761) to measure the thermal performance of steel-framed wall systems. The tests included an array of stud frame configurations, exterior sheathing and fiberglass batt insulations. Other studies have not included the use of insulating sheathing, which reduces the extent of the thermal bridges and improves total thermal performance. The purpose of the project was to provide measured R-values for commonly used steel-framed wall configurations and to improve R-value estimating methods. Test results were compared to R-value estimates using the parallel path method, the isothermal planes method and the ASHRAE Zone method. The comparison showed that the known procedures do not fully account for the three-dimensional effects created by steel framing in a wall.

  19. Towards flavour diffusion coefficient and electrical conductivity without ultraviolet contamination

    E-Print Network [OSTI]

    Y. Burnier; M. Laine

    2012-02-29

    By subtracting from a recent lattice measurement of the thermal vector-current correlator the known 5-loop vacuum contribution, we demonstrate that the remainder is small and shows no visible short-distance divergence. It can therefore in principle be subjected to model-independent analytic continuation. Testing a particular implementation, we obtain estimates for the flavour-diffusion coefficient (2 pi T D \\gsim 0.8) and electrical conductivity which are significantly smaller than previous results. Although systematic errors remain beyond control at present, some aspects of our approach could be of a wider applicability.

  20. Thermal Damage Characterization of Energetic Materials

    SciTech Connect (OSTI)

    Hsu, P C; DeHaven, M R; Springer, H K; Maienschein, J L

    2009-08-14

    We conducted thermal damage experiments at 180?C on PBXN-9 and characterized its material properties. Volume expansion at high temperatures was very significant which led to a reduction in material density. 2.6% of weight loss was observed, which was higher than other HMX-based formulations. Porosity of PBXN-9 increased to 16% after thermal exposure. Small-scale safety tests (impact, friction, and spark) showed no significant sensitization when the damaged samples were tested at room temperature. Gas permeation measurements showed that gas permeability in damaged materials was several orders of magnitude higher than that in pristine materials. In-situ measurements of gas permeability and density were proved to be possible at higher temperatures.

  1. 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.

  2. 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.

  3. 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

  4. Majorana Demonstrator Bolted Joint Mechanical and Thermal Analysis

    SciTech Connect (OSTI)

    Aguayo Navarrete, Estanislao; Reid, Douglas J.; Fast, James E.

    2012-06-01

    The MAJORANA DEMONSTRATOR is designed to probe for neutrinoless double-beta decay, an extremely rare process with a half-life in the order of 1026 years. The experiment uses an ultra-low background, high-purity germanium detector array. The germanium crystals are both the source and the detector in this experiment. Operating these crystals as ionizing radiation detectors requires having them under cryogenic conditions (below 90 K). A liquid nitrogen thermosyphon is used to extract the heat from the detectors. The detector channels are arranged in strings and thermally coupled to the thermosyphon through a cold plate. The cold plate is joined to the thermosyphon by a bolted joint. This circular plate is housed inside the cryostat can. This document provides a detailed study of the bolted joint that connects the cold plate and the thermosyphon. An analysis of the mechanical and thermal properties of this bolted joint is presented. The force applied to the joint is derived from the torque applied to each one of the six bolts that form the joint. The thermal conductivity of the joint is measured as a function of applied force. The required heat conductivity for a successful experiment is the combination of the thermal conductivity of the detector string and this joint. The thermal behavior of the joint is experimentally implemented and analyzed in this study.

  5. Electrical conductivity of pyrolyzed polyacrylonitrile

    SciTech Connect (OSTI)

    Teoh, H.; Metz, P.D.; Wilhelm, W.G.

    1981-01-01

    Using ultrapure samples of polyacrylonitrile (PAN) of 485,000 or 150,000 average molecular weight solution cast in dimethylformamide, the dc conductivity (sigma) of pyrolyzed PAN (PANP) films has been studied for pyrolysis temperatures (T/ sub p/) of 280 to 435/sup 0/C. Conductivity measurements made during pyrolysis indicate the onset of a dramatic increase in sigma for T/sub p/ of 390 to 435/sup 0/C. Conductivities as high as 5 (ohm-cm)/sup -1/ have been observed for T/sub p/ < 435/sup 0/C.

  6. Effect of current compliance and voltage sweep rate on the resistive switching of HfO{sub 2}/ITO/Invar structure as measured by conductive atomic force microscopy

    SciTech Connect (OSTI)

    Wu, You-Lin Liao, Chun-Wei; Ling, Jing-Jenn

    2014-06-16

    The electrical characterization of HfO{sub 2}/ITO/Invar resistive switching memory structure was studied using conductive atomic force microscopy (AFM) with a semiconductor parameter analyzer, Agilent 4156C. The metal alloy Invar was used as the metal substrate to ensure good ohmic contact with the substrate holder of the AFM. A conductive Pt/Ir AFM tip was placed in direct contact with the HfO{sub 2} surface, such that it acted as the top electrode. Nanoscale current-voltage (I-V) characteristics of the HfO{sub 2}/ITO/Invar structure were measured by applying a ramp voltage through the conductive AFM tip at various current compliances and ramp voltage sweep rates. It was found that the resistance of the low resistance state (RLRS) decreased with increasing current compliance value, but resistance of high resistance state (RHRS) barely changed. However, both the RHRS and RLRS decreased as the voltage sweep rate increased. The reasons for this dependency on current compliance and voltage sweep rate are discussed.

  7. Frequency Dependent Specific Heat from Thermal Effusion in Spherical Geometry

    E-Print Network [OSTI]

    Bo Jakobsen; Niels Boye Olsen; Tage Christensen

    2010-03-11

    We present a novel method of measuring the frequency dependent specific heat at the glass transition applied to 5-polyphenyl-4-ether. The method employs thermal waves effusing radially out from the surface of a spherical thermistor that acts as both a heat generator and thermometer. It is a merit of the method compared to planar effusion methods that the influence of the mechanical boundary conditions are analytically known. This implies that it is the longitudinal rather than the isobaric specific heat that is measured. As another merit the thermal conductivity and specific heat can be found independently. The method has highest sensitivity at a frequency where the thermal diffusion length is comparable to the radius of the heat generator. This limits in practise the frequency range to 2-3 decades. An account of the 3omega-technique used including higher order terms in the temperature dependency of the thermistor and in the power generated is furthermore given.

  8. 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.

  9. Quantifying surface watergroundwater interactions using time series analysis of streambed thermal records

    E-Print Network [OSTI]

    Fisher, Andrew

    of variable streambed hydraulic conductivity. This new approach should facilitate wider use of thermal methods streams in the western United States have declined during the summer and fall in recent years, when in base flow and changes in groundwater recharge [e.g., Bredehoeft et al., 1982], but measuring

  10. Heat flux measurement from thermal infrared imagery in low-flux fumarolic zones: Example of the Ty fault (La Soufrire de Guadeloupe)

    E-Print Network [OSTI]

    Beauducel, François

    the geothermal flux of a dormant volcano is necessary both for hazard assessment and for studying hydrothermal for the thermal infrared method, and 275 ± 50 W/m2 for the vertical temperature gradient method), if surface through connected porosity and fissures of rocks in which the thermal vertical gradient is nil. Near

  11. 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

  12. 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, ...

  13. Comparison of an electro-optical system and photo-conducting antenna employed as detectors of pulsed terahertz radiation by means of a new method for measuring spectral width

    SciTech Connect (OSTI)

    Grachev, Ya V; Osipova, M O; Bespalov, V G

    2014-12-31

    Two detection systems, electro-optical system and photoconducting system, are tested by the method suggested previously for determining the boundaries of broadband terahertz radiation in time-domain spectroscopy. From a series of measurements the error in determining the operation ranges is calculated. The terahertz spectrometer with an electro-optical detector based on a ZnTe (110) crystal of thickness 2 mm has the operation spectral range of 0.059 – 1.092 THz. The detector utilizing an iPCA-21-05-1000-800-h photo-conducting antenna with the same source of signal demonstrates a wider operation band ranging from 0.017 to 1.6 THz. The method developed makes it possible to experimentally compare the parameters of the considered terahertz spectrometers obtained under the same quality of adjustment. (laser applications and other topics in quantum electronics)

  14. 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

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. Heat generation rate measurement in a Li-ion cell at large C-rates through temperature and heat flux measurements

    E-Print Network [OSTI]

    Texas at Arlington, University of

    Heat generation rate measurement in a Li-ion cell at large C-rates through temperature and heat Keywords: Lithium-ion batteries Heat generation rate measurement Heat flux sensor Thermal conduction Battery safety a b s t r a c t Understanding the rate of heat generation in a Li-ion cell is critical

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. Sub-sonic thermal explosions investigated by radiography

    SciTech Connect (OSTI)

    Smilowitz, Laura B; Henson, Bryan F; Romero, Jerry J; Asay, Blaine W

    2010-01-01

    This paper reviews the past 5 years of experiments utilizing radiographic techniques to study defiagration in thermal explosions in HMX based formulations. Details of triggering and timing synchronization are given. Radiographic images collected using both protons and x-rays are presented. Comparisons of experiments with varying size, case confinement, binder, and synchronization are presented. Techniques for quantifying the data in the images are presented and a mechanism for post-ignition burn propagation in a thermal explosion is discussed. From these experiments, we have observed a mechanism for sub-sonic defiagration with both gas phase convective and solid phase conductive burning. The convective front velocity is directly measured from the radiographic images and consumes only a small fraction of the HE. It lights the HE as it passes beginning the slower solid state conductive burn process. This mechanism is used to create a model to simulate the radiographic results and a comparison will be shown.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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...

  10. 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.

  11. Thermal performance of various multilayer insulation systems below 80K

    SciTech Connect (OSTI)

    Boroski, W.N.; Nicol, T.H.; Schoo, C.J.

    1992-04-01

    The SSC collider dipole cryostat consists of a vacuum shell operating at room temperature, two thermal shields operating near 80K and 20K respectively, and the superconducting magnet assembly operating near 4K. The cryostat design incorporates multilayer insulation (MLI) blankets to limit radiant heat transfer into the 80K and 20K thermal shields. Also, an MLI blanket is used to impede heat transfer through residual gas conduction into the 4K superconducting magnet assembly. A measurement facility at Fermilab has been used to experimentally optimize the thermal insulation system for the dipole cryostat. Previous thermal measurements have been used to define the 80K MLI system configuration and verify system performance. With the 80K MLI system defined, the current effort has focused on experimentally defining the optimum insulation scheme for the 20K thermal shield. The SSC design specification requires that radiant heat transfer be limited to 0.093 W/m[sup 2] at an insulating vacuum of 10[sup [minus]6]torr.

  12. Thermal performance of various multilayer insulation systems below 80K

    SciTech Connect (OSTI)

    Boroski, W.N.; Nicol, T.H.; Schoo, C.J.

    1992-04-01

    The SSC collider dipole cryostat consists of a vacuum shell operating at room temperature, two thermal shields operating near 80K and 20K respectively, and the superconducting magnet assembly operating near 4K. The cryostat design incorporates multilayer insulation (MLI) blankets to limit radiant heat transfer into the 80K and 20K thermal shields. Also, an MLI blanket is used to impede heat transfer through residual gas conduction into the 4K superconducting magnet assembly. A measurement facility at Fermilab has been used to experimentally optimize the thermal insulation system for the dipole cryostat. Previous thermal measurements have been used to define the 80K MLI system configuration and verify system performance. With the 80K MLI system defined, the current effort has focused on experimentally defining the optimum insulation scheme for the 20K thermal shield. The SSC design specification requires that radiant heat transfer be limited to 0.093 W/m{sup 2} at an insulating vacuum of 10{sup {minus}6}torr.

  13. 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.

  14. 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.

  15. 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.

  16. Electronically conductive polymer composites and microstructures

    SciTech Connect (OSTI)

    Van Dyke, L.S.

    1993-01-01

    Composites of electronically conductive polymers with insulating host materials are investigated. A template synthesis method was developed for the production of electronically conductive polymer microstructures. In template synthesis the pores of a porous host membrane act as templates for the polymerization of a conductive polymer. The template synthetic method can be used to form either solid microfibrils or hollow microtubules. The electrochemical properties of conductive polymers produced via the template synthesis method are superior to those of conventionally synthesized conductive polymers. Electronically conductive polymers are used to impart conductivity to non-conductive materials. Two different approaches are used. First, thin film composites of conductive polymers with fluoropolymers are made by the polymerization of conductive polymers onto fluoropolymer films. Modification of the fluoropolymer surface prior to conductive polymer polymerization is necessary to obtain good adhesion between the two materials. The difference in adhesion of the conductive polymer to the modified and unmodified fluoropolymer surfaces can be used to pattern the conductive polymer coating. Patterning of the conductive polymer coating can alternatively be done via UV laser ablation of the conductive polymer. The second method by which conductive polymers were used to impart conductivity to an insulating polymer was via the formation of a graft copolymer. In this approach, heterocyclic monomers grafted to an insulating polyphosphazene backbone were polymerized to yield semiconductive materials. Finally the measurement of electrolyte concentration in polypyrrole and the effects of hydroxide anion on the electrochemical and electrical properties of polypyrrole are described. It is shown that treatment of polypyrrole with hydroxide anion increases the potential window over which polypyrrole is a good electronic conductor.

  17. 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...

  18. Plasma momentum meter for momentum flux measurements

    DOE Patents [OSTI]

    Zonca, Fulvio (Rome, IT); Cohen, Samuel A. (Hopewell, NJ); Bennett, Timothy (Princeton, NJ); Timberlake, John R. (Allentown, NJ)

    1993-01-01

    Invention comprises an instrument in which momentum flux onto a biasable target plate is transferred via a suspended quartz tube onto a sensitive force transducer--a capacitance-type pressure gauge. The transducer is protected from thermal damage, arcing and sputtering, and materials used in the target and pendulum are electrically insulating, rigid even at elevated temperatures, and have low thermal conductivity. The instrument enables measurement of small forces (10.sup.-5 to 10.sup.3 N) accompanied by high heat fluxes which are transmitted by energetic particles with 10's of eV of kinetic energy in a intense magnetic field and pulsed plasma environment.

  19. 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

  20. 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...

  1. 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,

  2. 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...

  3. 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

  4. 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...

  5. 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...

  6. 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.

  7. 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...

  8. 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, ...

  9. Next-Generation LED Package Architectures Enabled by Thermally Conductive

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergy Bills and Reduce Carbon PollutionZealand JoinsJuneEmergingTransparent

  10. Novel Transparent Phosphor Conversion Matrix with High Thermal Conductivity

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankADVANCED MANUFACTURINGEnergy Bills and Reduce CarbonEnergyDepartment13Department of EnergyMEAs

  11. 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

  12. Invited Review Article: Error and uncertainty in Raman 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 NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby aLED Street LightingFrom theHighI _ Interview

  13. T I ENHANCING THERMAL CONDUCTIVITY OF FLUIDS WITH NANOPARTICLES*

    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 MunicipalTechnicalInformation FederatedInformation What'sfunction (Journal(TechnicalC A L I F

  14. Continuous Processing of High Thermal Conductivity 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 Gang Chen,

  15. 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

  16. 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

  17. 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)

  18. Evidence of ion mixing increasing the thermal boundary conductance across

    Office of Scientific and Technical Information (OSTI)

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  19. Experimental and numerical study of the effective thermal conductivity of

    Office of Scientific and Technical Information (OSTI)

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  20. Heat diode effect and negative differential thermal conductance across

    Office of Scientific and Technical Information (OSTI)

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  1. Microstructure changes and thermal conductivity reduction in UO2 following

    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(JournalspectroscopyReport) |(Patent)Inter-Nucleon InteractionsElectron Beam2}CuO{sub3.9

  2. Thermal Conductivity in Nanocrystalline Ceria Thin Films (Journal Article)

    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 NaturalDukeWakefieldSulfateSciTechtail.Theory of rare Kaon and Pion decays Citation Details In-Document| SciTech Connect

  3. Glass-like thermal conductivity in high efficiency thermoelectric materials

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum12,Executive CompensationEnergyGet Current: Switch onDepartment2GlassGlass|

  4. Los Alamos probes mysteries of uranium dioxide's thermal conductivity

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home Room NewsInformationJesse BergkampCentermillion to local Unitedto

  5. 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.

  6. Operation Greenhouse. Scientific Director's report of atomic weapon tests at Eniwetok, 1951. Annex 1. 5. Neutron measurements. Part 2. External neutron- and gamma flux measurements by sample activation. Section 1

    SciTech Connect (OSTI)

    Biggers, W.A.; Brown, L.J.

    1985-09-01

    The Greenhouse operation consisted of a series of four shots conducted at Eniwetok during the Srping of 1951. The external neutron threshold measurements consisted of the use of good samples to measure integrated thermal neutron fluxes and sulfur, iodine, and zirconium samples to measure fluxes of higher-energy neutrons. The iodine also measured high-energy gamma-ray intensity. Measurements were also made on slow- and fast-neutron intensities as a function of time.

  7. Fracture Conductivity of the Eagle Ford Shale 

    E-Print Network [OSTI]

    Guzek, James J

    2014-07-25

    Hydraulic fracturing is a well completions technique that induces a network of flow channels in a reservoir. These channels are characterized by fracture conductivity, a measure of how easily a liquid or gas flows through the fracture. Fracture...

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Thermal properties of the optically transparent pore-free nanostructured yttria-stabilized zirconia

    SciTech Connect (OSTI)

    Ghosh, S.; Teweldebrhan, D.; Morales, J. R.; Garay, J. E.; Balandin, A. A.

    2009-12-01

    The authors report results of investigation of thermal conductivity of nanocrystalline yttria-stabilized zirconia. The optically transparent pore-free bulk samples were prepared via the spark plasma sintering process to ensure homogeneity. Thermal conductivity K was measured by two different techniques. It was found that the pore-free nanostructured bulk zirconia is an excellent thermal insulator with the room-temperature Kapprox1.7-2.0 W/m K. It was also shown that the 'phonon-hopping' model can accurately describe specifics of K dependence on temperature and the grain size. The obtained results are important for optimization of zirconia properties for specific applications in advanced electronics and coatings.

  13. 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...

  14. 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

  15. 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.

  16. 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...

  17. 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.

  18. Electron density measurements of atmospheric-pressure non-thermal N{sub 2} plasma jet by Stark broadening and irradiance intensity methods

    SciTech Connect (OSTI)

    Xiao, Dezhi; Shen, Jie; Lan, Yan; Xie, Hongbing; Shu, Xingsheng; Meng, Yuedong; Li, Jiangang; Cheng, Cheng E-mail: paul.chu@cityu.edu.hk; Chu, Paul K. E-mail: paul.chu@cityu.edu.hk

    2014-05-15

    An atmospheric-pressure non-thermal plasma jet excited by high frequency alternating current using nitrogen is developed and the electron density in the active region of this plasma jet is investigated by two different methods using optical emission spectroscopy, Stark broadening, and irradiance intensity method. The irradiance intensity method shows that the average electron density is about 10{sup 20}/m{sup 3} which is slightly smaller than that by the Stark broadening method. However, the trend of the change in the electron density with input power obtained by these two methods is consistent.

  19. Thermal transport in shock wave–compressed solids using pulsed laser heating

    SciTech Connect (OSTI)

    La Lone, B. M., E-mail: lalonebm@nv.doe.gov; Capelle, G.; Stevens, G. D.; Turley, W. D.; Veeser, L. R. [National Security Technologies, LLC, Special Technologies Laboratory, Santa Barbara, California 93111 (United States)

    2014-07-15

    A pulsed laser heating method was developed for determining thermal transport properties of solids under shock-wave compression. While the solid is compressed, a laser deposits a known amount of heat onto the sample surface, which is held in the shocked state by a transparent window. The heat from the laser briefly elevates the surface temperature and then diffuses into the interior via one-dimensional heat conduction. The thermal effusivity is determined from the time history of the resulting surface temperature pulse, which is recorded with optical pyrometry. Thermal effusivity is the square root of the product of thermal conductivity and volumetric heat capacity and is the key thermal transport parameter for relating the surface temperature to the interior temperature of the sample in a dynamic compression experiment. Therefore, this method provides information that is needed to determine the thermodynamic state of the interior of a compressed metal sample from a temperature measurement at the surface. The laser heat method was successfully demonstrated on tin that was shock compressed with explosives to a stress and temperature of ?25 GPa and ?1300 K. In this state, tin was observed to have a thermal effusivity of close to twice its ambient value. The implications on determining the interior shock wave temperature of tin are discussed.

  20. Hybrid tomography for conductivity imaging

    E-Print Network [OSTI]

    T. Widlak; O. Scherzer

    2012-03-20

    Hybrid imaging techniques utilize couplings of physical modalities -- they are called hybrid, because, typically, the excitation and measurement quantities belong to different modalities. Recently there has been an enormous research interest in this area because these methods promise very high resolution. In this paper we give a review on hybrid tomography methods for \\emph{electrical conductivity} imaging. The reviewed imaging methods utilize couplings between electric, magnetic and ultrasound modalities. By this it is possible to perform high-resolution electrical impedance imaging and to overcome the low-resolution problem of electric impedance tomography.