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1

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

E-Print Network [OSTI]

1 Pump-probe measurements of the thermal conductivity tensor for materials lacking in conductivity corresponding to the scanning direction. Also, we demonstrate Nb- V as a low thermal conductivity thermal conductivity tensor and the illuminating spots have arbitrary intensity profiles

Cahill, David G.

2

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

SciTech Connect (OSTI)

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.

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)

2014-10-15T23:59:59.000Z

3

Thermal conductivity of thermal-battery insulations  

SciTech Connect (OSTI)

The thermal conductivities of a variety of insulating materials used in thermal batteries were measured in atmospheres of argon and helium using several techniques. (Helium was used to simulate the hydrogen atmosphere that results when a Li(Si)/FeS{sub 2} thermal battery ages.) The guarded-hot-plate method was used with the Min-K insulation because of its extremely low thermal conductivity. For comparison purposes, the thermal conductivity of the Min-K insulating board was also measured using the hot-probe method. The thermal-comparator method was used for the rigid Fiberfrax board and Fiberfrax paper. The thermal conductivity of the paper was measured under several levels of compression to simulate the conditions of the insulating wrap used on the stack in a thermal battery. The results of preliminary thermal-characterization tests with several silica aerogel materials are also presented.

Guidotti, R.A.; Moss, M.

1995-08-01T23:59:59.000Z

4

Time-resolved electron thermal conduction by probing of plasma formation in transparent solids with high power subpicosecond laser pulses  

SciTech Connect (OSTI)

This dissertation work includes a series of experimental measurements in a search for better understanding of high temperature (10{sup 4}-10{sup 6}K) and high density plasmas (10{sup 22}-10{sup 24}cm{sup {minus}3}) produced by irradiating a transparent solid target with high intensity (10{sup 13} - 10{sup 15}W/cm{sup 2}) and subpicosecond (10{sup {minus}12}-10{sup {minus}13}s) laser pulses. Experimentally, pump and probe schemes with both frontside (vacuum-plasma side) and backside (plasma-bulk material side) probes are used to excite and interrogate or probe the plasma evolution, thereby providing useful insights into the plasma formation mechanisms. A series of different experiments has been carried out so as to characterize plasma parameters and the importance of various nonlinear processes. Experimental evidence shows that electron thermal conduction is supersonic in a time scale of the first picosecond after laser irradiation, so fast that it was often left unresolved in the past. The experimental results from frontside probing demonstrate that upon irradiation with a strong (pump) laser pulse, a thin high temperature ({approximately}40eV) super-critical density ({approximately}10{sup 23}/cm{sup 3}) plasma layer is quickly formed at the target surface which in turn becomes strongly reflective and prevents further transmission of the remainder of the laser pulse. In the bulk region behind the surface, it is also found that a large sub-critical ({approximately}10{sup 18}/cm{sup 3}) plasma is produced by inverse Bremsstrahlung absorption and collisional ionization. The bulk underdense plasma is evidenced by large absorption of the backside probe light. A simple and analytical model, modified from the avalanche model, for plasma evolution in transparent materials is proposed to explain the experimental results. Elimination of the bulk plasma is then experimentally illustrated by using targets overcoated with highly absorptive films.

Vu, B.T.V.

1994-02-01T23:59:59.000Z

5

Cermet fuel thermal conductivity  

E-Print Network [OSTI]

CERMET FUEL THERMAL CONDUCTIVITY A Thesis by JOHN MARK ALVIS, JR. Submitted to the Graduate College of Texas A&. M University in partial fulfilment of the requirements for the degree of MASTER OF SCIENCE August 1988 Major Subject: Nuclear... particles of low conductivity dispersed in a metal matrix of high conductivity. A computer code was developed in order to compute the conductivity of cermet fuels as predicted by existing models and an additional model derived in this work...

Alvis, John Mark

1988-01-01T23:59:59.000Z

6

Low thermal conductivity skutterudites  

SciTech Connect (OSTI)

Recent experimental results on semiconductors with the skutterudite crystal structure show that these materials possess attractive transport properties and have a good potential for achieving ZT values substantially larger than for state-of-the-art thermoelectric materials. Both n-type and p-type conductivity samples have been obtained, using several preparation techniques. Associated with a low hole effective mass, very high carrier mobilities, low electrical resistivities and moderate Seebeck coefficients are obtained in p-type skutterudites. For a comparable doping level, the carrier mobilities of n-type samples are about an order of magnitude lower than the values achieved on p-type samples. However, the much larger electron effective masses and Seebeck coefficients on p-type samples. However, the much larger electron effective masses and Seebeck coefficients make n-type skutterudite promising candidates as well. Unfortunately, the thermal conductivities of the binary skutterudites compounds are too large, particularly at low temperatures, to be useful for thermoelectric applications. Several approaches to the reduction of the lattice thermal conductivity in skutterudites are being pursued: heavy doping, formation of solid solutions and alloys, study of novel ternary and filled skutterudite compounds. All those approaches have already resulted in skutterudite compositions with substantially lower thermal conductivity values in these materials. Recently, superior thermoelectric properties in the moderate to high temperature range were achieved for compositions combining alloying and filling of the skutterudite structure. Experimental results and mechanisms responsible for low thermal conductivity in skutterudites are discussed.

Fleurial, J.P.; Caillat, T.; Borshchevsky, A.

1997-07-01T23:59:59.000Z

7

Low Conductivity Thermal Barrier Coatings  

E-Print Network [OSTI]

Low Conductivity Thermal Barrier Coatings A Dissertation Presented to The Faculty of the School conductivity of the coatings. The minimum thermal conductivity occurs at a low rotation rate and is 0.8 W intrinsic thermal conductivity, good phase stability and greater resistance to sintering and CMAS attack

Wadley, Haydn

8

Enhanced Thermal Conductivity Oxide Fuels  

SciTech Connect (OSTI)

the purpose of this project was to investigate the feasibility of increasing the thermal conductivity of oxide fuels by adding small fractions of a high conductivity solid phase.

Alvin Solomon; Shripad Revankar; J. Kevin McCoy

2006-01-17T23:59:59.000Z

9

Experimental investigations of solid-solid thermal interface conductance  

E-Print Network [OSTI]

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 ...

Collins, Kimberlee C. (Kimberlee Chiyoko)

2010-01-01T23:59:59.000Z

10

Continuous Processing of High Thermal Conductivity Polyethylene...  

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

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

11

NANO REVIEW Open Access Thermal conductivity and thermal boundary  

E-Print Network [OSTI]

NANO REVIEW Open Access Thermal conductivity and thermal boundary resistance of nanostructures and the thermal transport prop- erties is a key point to design materials with preferred thermal properties with the heat dissipation on them. The influence of the interfacial roughness on the thermal conductivity

Boyer, Edmond

12

Thermal Conductivity of Polycrystalline Semiconductors and Ceramics  

E-Print Network [OSTI]

semiconductors and ceramics with desired thermalthermal conductivity of several polycrystalline semiconductors and ceramics,Thermal Conductivity of Polycrystalline Semiconductors and Ceramics

Wang, Zhaojie

2012-01-01T23:59:59.000Z

13

Reduced Thermal Conductivity of Compacted Silicon Nanowires  

E-Print Network [OSTI]

Thermal-Barrier-Coating Applications,” Journa of American Ceramicthermal conductivity materials are typically found among ceramicsThermal Conductivity of Porous Materials: Application to Thick Barrier Coatings,” Journal of the European Ceramic

Yuen, Taylor S.

14

Experimental thermal conductivity and contact conductance of graphite composites  

E-Print Network [OSTI]

Figure 2. 1 One-Dimensional Heat Transfer by Conduction Across a Plane Wall Figure 2. 2 Fundamental Element for Electrically Based Thermal Model. . . 14 Figure 2. 3 Rectangular Unit Cell Orientation . 14 Figure 2. 4 Model of Parabolic Distribution... a low transverse thermal conductivity, they show better thermal performance than MMC's for some weight-critical applications (Ibrahim, 1992). Graphite/organic compound composites also will be reviewed. Using a high conductivity graphite fiber...

Jackson, Marian Christine

1998-01-01T23:59:59.000Z

15

Thermal Conductivity and Noise Attenuation in  

E-Print Network [OSTI]

.3.4 Corrosion-resistant and high-temperature filters 9 1.3.5 Acoustic Applications 9 2. THERMAL CONDUCTIVITY 2.1 THERMAL RESISTANCE 2.1.1 Thermal Conductors in Series 12 2.1.2 Thermal conductors in parallel 13 2 difference RTH Thermal resistance of conductor sb Stefan's constant T4 Temperature difference K* Total

Cambridge, University of

16

Thermal conductivity and heat transfer in superlattices  

SciTech Connect (OSTI)

Understanding the thermal conductivity and heat transfer processes in superlattice structures is critical for the development of thermoelectric materials and devices based on quantum structures. This work reports progress on the modeling of thermal conductivity of superlattice structures. Results from the models established based on the Boltzmann transport equation could explain existing experimental results on the thermal conductivity of semiconductor superlattices in both in plane and cross-plane directions. These results suggest the possibility of engineering the interfaces to further reduce thermal conductivity of superlattice structures.

Chen, G.; Neagu, M.; Borca-Tasciuc, T.

1997-07-01T23:59:59.000Z

17

Thermal conductivity measurements of Summit polycrystalline silicon.  

SciTech Connect (OSTI)

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.

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

2006-11-01T23:59:59.000Z

18

An Innovative High Thermal Conductivity Fuel Design  

SciTech Connect (OSTI)

Thermal conductivity of the fuel in today's Light Water Reactors, Uranium dioxide, can be improved by incorporating a uniformly distributed heat conducting network of a higher conductivity material, Silicon Carbide. The higher thermal conductivity of SiC along with its other prominent reactor-grade properties makes it a potential material to address some of the related issues when used in UO2 [97% TD]. This ongoing research, in collaboration with the University of Florida, aims to investigate the feasibility and develop a formal methodology of producing the resultant composite oxide fuel. Calculations of effective thermal conductivity of the new fuel as a function of %SiC for certain percentages and as a function of temperature are presented as a preliminary approach. The effective thermal conductivities are obtained at different temperatures from 600K to 1600K. The corresponding polynomial equations for the temperature-dependent thermal conductivities are given based on the simulation results. Heat transfer mechanism in this fuel is explained using a finite volume approach and validated against existing empirical models. FLUENT 6.1.22 was used for thermal conductivity calculations and to estimate reduction in centerline temperatures achievable within such a fuel rod. Later, computer codes COMBINE-PC and VENTURE-PC were deployed to estimate the fuel enrichment required, to maintain the same burnup levels, corresponding to a volume percent addition of SiC.

Jamil A. Khan

2009-11-21T23:59:59.000Z

19

Electrical and thermal conductivities in dense plasmas  

SciTech Connect (OSTI)

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.

Faussurier, G., E-mail: gerald.faussurier@cea.fr; Blancard, C.; Combis, P.; Videau, L. [CEA, DAM, DIF, F-91297 Arpajon (France)

2014-09-15T23:59:59.000Z

20

Thermal conductivity of bulk nanostructured lead telluride  

SciTech Connect (OSTI)

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.

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)

2014-01-13T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Increased thermal conductivity monolithic zeolite structures  

DOE Patents [OSTI]

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.

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

2008-11-25T23:59:59.000Z

22

Thermal Conductivity in Nanocrystalline Ceria Thin Films  

SciTech Connect (OSTI)

The thermal conductivity of nanocrystalline ceria films grown by unbalanced magnetron sputtering is determined as a function of temperature using laser-based modulated thermoreflectance. The films exhibit significantly reduced conductivity compared with stoichiometric bulk CeO2. A variety of microstructure imaging techniques including X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron analysis, and electron energy loss spectroscopy indicate that the thermal conductivity is influenced by grain boundaries, dislocations, and oxygen vacancies. The temperature dependence of the thermal conductivity is analyzed using an analytical solution of the Boltzmann transport equation. The conclusion of this study is that oxygen vacancies pose a smaller impediment to thermal transport when they segregate along grain boundaries.

Marat Khafizov; In-Wook Park; Aleksandr Chernatynskiy; Lingfeng He; Jianliang Lin; John J. Moore; David Swank; Thomas Lillo; Simon R. Phillpot; Anter El-Azab; David H. Hurley

2014-02-01T23:59:59.000Z

23

Measuring Thermal Transport in Extreme Environments: Thermal Conductivity  

E-Print Network [OSTI]

Chen California Institute of Technology Jackie Li University of Michigan supported by CarnegieMeasuring Thermal Transport in Extreme Environments: Thermal Conductivity of Water Ice VII to 20 GPa David G. Cahill, Wen-Pin Hsieh, Dallas Trinkle, University of Illinois at Urbana-Champaign Bin

Braun, Paul

24

Gas storage carbon with enhanced thermal conductivity  

DOE Patents [OSTI]

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.

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

2000-01-01T23:59:59.000Z

25

Molecular Dynamic Study of Thermal Conductivity of Amorphous Nanoporous Silica  

E-Print Network [OSTI]

as a thermal isolation layer”. Ceramics International, 34(Thermal conductivity of highly porous zirconia”. Journal of the European Ceramic

Coquil, Thomas; Fang, Jin; Pilon, Laurent

2011-01-01T23:59:59.000Z

26

Continuous Processing of High Thermal Conductivity Fibers and...  

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

We are developing a continuous fabrication process for high thermal conductivity polyethylene (PE) films While high thermal conductivity in (PE) has been shown in isolated...

27

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...

28

Measurement of thermal conductivity P t BPart B  

E-Print Network [OSTI]

wave Take the Fourier transform of this frequency domain solution #12;For a low thermal conductivity thin filmFor a low thermal conductivity thin film on a high thermal conductivity substrate (Factor of 2Measurement of thermal conductivity Part A: P t BPart B: · Time domain thermoreflectance #12

Braun, Paul

29

Effective Thermal Conductivity of Graded Nanocomposites with Interfacial Thermal  

E-Print Network [OSTI]

.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

Paulino, Glaucio H.

30

Thermal conductance of solid-liquid interfaces Scott Huxtable, Zhenbin Ge, David G. Cahill  

E-Print Network [OSTI]

thermal conductivity in nanostructured materials ­ improved thermoelectric energy conversion improved/surfactant/water PMMA/Al2O3 nanotube/alkane #12;Modulated pump-probe apparatus f=10 MHz rf lock-in #12;Solid · Cooling rate (RC time constant) gives interface conductance G = 12 MW m-2 K-1G = 12 MW m K #12;Application

Braun, Paul

31

Ultralow thermal conductivity and the thermal d t f i t fconductance of interfaces  

E-Print Network [OSTI]

are critical at the nanoscale · Low thermal conductivity in nanostructured materials ­ improved thermoelectric to the thermal conductivity of materials. · Ultralow thermal conductivity: beating the amorphous limitUltralow thermal conductivity and the thermal d t f i t fconductance of interfaces David G. Cahill

Braun, Paul

32

Ultralow Thermal Conductivity of Isotope-Doped Silicon Nanowires  

E-Print Network [OSTI]

conductivity of SiNWs is about 2 orders of magnitude smaller than that of bulk crystals.18,19 The low thermal conductivity (0.05 W/m K) found in layered materials.22 So it is indispensable to reduce the thermal conUltralow Thermal Conductivity of Isotope-Doped Silicon Nanowires Nuo Yang, Gang Zhang,*, and Baowen

Li, Baowen

33

Monte Carlo Simulations of Thermal Conductivity in Nanoporous Si Membranes  

E-Print Network [OSTI]

candidates for thermoelectric materials as they can provide extremely low thermal conductivity , relatively of boundary scattering on the thermal conductivity. We show that the material porosity strongly affects1 Monte Carlo Simulations of Thermal Conductivity in Nanoporous Si Membranes Stefanie Wolf1

34

Pushing the boundaries of the thermal conductivity of materials  

E-Print Network [OSTI]

Pushing the boundaries of the thermal conductivity of materials David G. Cahill, C. Chiritescu, Y. · Advances in time-domain thermoreflectance. · Amorphous limit to the thermal conductivity of materials. #12;50 nm Interfaces are critical at the nanoscale · Low thermal conductivity in nanostructured

Braun, Paul

35

Thermal Conductivity of High-Modulus Polymer Fibers Xiaojia Wang,*,  

E-Print Network [OSTI]

to be the dominate carriers of heat. 1. INTRODUCTION Polymeric materials typically have a low thermal conductivity transfer is critical are often limited by low thermal conductivity. Here, we leverage the enormous research and low-density PE with varying fiber volume fractions.11 They reported an axial thermal conductivity

Cahill, David G.

36

THERMAL CONDUCTIVITY OF HEMP CONCRETES: VARIATION WITH FORMULATION, DENSITY AND  

E-Print Network [OSTI]

envelope and on the performance of systems. This behaviour is related to hygric and thermal propertiesTHERMAL CONDUCTIVITY OF HEMP CONCRETES: VARIATION WITH FORMULATION, DENSITY AND WATER CONTENT of formulation, density and water content on the thermal conductivity of hemp concretes. The investigations

37

Thermal conductivity of electroless nickel-phosphorus alloy plating  

SciTech Connect (OSTI)

Properties of specific heat, thermal diffusivity, density, and calculated thermal conductivity have been determined for a modified acid bath electroless nickel-12.7 wt% phosphorus alloy between 298 ad 423 K. Thermal conductivity values are about half those of pure nickel.

Smith, D.D.

1982-04-01T23:59:59.000Z

38

Morphology and thermal conductivity of yttria-stabilized zirconia coatings  

E-Print Network [OSTI]

yttria-stabilized zir- conia (YSZ) is then applied to provide thermal insulation [1]. This ceramic layer]. The thermal conductivity of the ceramic layer has been found to depend on the pore morphology within a coatingMorphology and thermal conductivity of yttria-stabilized zirconia coatings Hengbei Zhao a

Wadley, Haydn

39

Thermal Conductivity of Polycrystalline Semiconductors and Ceramics  

E-Print Network [OSTI]

Brown, C. M. ; Zhang, Q. ; Tritt, T. M. Nano Letters 2010,Monteiro, O. Microelectronics journal Tritt, T. M. , Thermal

Wang, Zhaojie

2012-01-01T23:59:59.000Z

40

Thermal conductivity of graphene nanoribbons in noble gaseous environments  

SciTech Connect (OSTI)

We investigate the thermal conductivity of suspended graphene nanoribbons in noble gaseous environments using molecular dynamics simulations. It is reported that the thermal conductivity of perfect graphene nanoribbons decreases with the gaseous pressure. The decreasing is more obvious for the noble gas with large atomic number. However, the gaseous pressure cannot change the thermal conductivity of defective graphene nanoribbons apparently. The phonon spectra of graphene nanoribbons are also provided to give corresponding supports.

Zhong, Wei-Rong, E-mail: wrzhong@hotmail.com; Xu, Zhi-Cheng; Zheng, Dong-Qin [Department of Physics and Siyuan Laboratory, College of Science and Engineering, Jinan University, Guangzhou 510632 (China); Ai, Bao-Quan, E-mail: aibq@scnu.edu.cn [Laboratory of Quantum Information Technology, ICMP and SPTE, South China Normal University, Guangzhou 510006 (China)

2014-02-24T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Estimation of composite thermal conductivity of a heterogeneous methane hydrate sample using iTOUGH2  

E-Print Network [OSTI]

15–17, 2006 ESTIMATION OF COMPOSITE THERMAL CONDUCTIVITY OFABSTRACT We determined the composite thermal conductivity (kfrom granular ice. The composite thermal conductivity was

Gupta, Arvind; Kneafsey, Timothy J.; Moridis, George J.; Seol, Yongkoo; Kowalsky, Michael B.; Sloan Jr., E.D.

2006-01-01T23:59:59.000Z

42

Electrical and thermal conductivity of low temperature CVD graphene...  

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

and thermal conductivity of low temperature CVD graphene: the effect of disorder This article has been downloaded from IOPscience. Please scroll down to see the full text article....

43

Duality of the Interfacial Thermal Conductance in Graphene-based Nanocomposites  

SciTech Connect (OSTI)

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.

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

2014-01-01T23:59:59.000Z

44

MOLECULAR DYNAMICS SIMULATION OF THERMAL BOUNDARY CONDUCTANCE BETWEEN SWNT AND  

E-Print Network [OSTI]

MOLECULAR DYNAMICS SIMULATION OF THERMAL BOUNDARY CONDUCTANCE BETWEEN SWNT AND SURROUNDING FLUIDS JinHyeok Cha, Shohei Chiashi, Junichiro Shiomi, and Shigeo Maruyama* Department of Mechanical applications. In particular, the thermal boundary conductance (TBC) K between an SWNT and surrounding fluid

Maruyama, Shigeo

45

THERMAL CONDUCTIVITY AND OTHER PROPERTIES OF CEMENTITIOUS GROUTS  

SciTech Connect (OSTI)

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.

ALLAN,M.

1998-05-01T23:59:59.000Z

46

The thermal conductivity of rock under hydrothermal conditions: measurements and applications  

SciTech Connect (OSTI)

The thermal conductivities of most major rock-forming minerals vary with both temperature and confining pressure, leading to substantial changes in the thermal properties of some rocks at the high temperatures characteristic of geothermal systems. In areas with large geothermal gradients, the successful use of near-surface heat flow measurements to predict temperatures at depth depends upon accurate corrections for varying thermal conductivity. Previous measurements of the thermal conductivity of dry rock samples as a function of temperature were inadequate for porous rocks and susceptible to thermal cracking effects in nonporous rocks. We have developed an instrument for measuring the thermal conductivity of water-saturated rocks at temperatures from 20 to 350 °C and confining pressures up to 100 MPa. A transient line-source of heat is applied through a needle probe centered within the rock sample, which in turn is enclosed within a heated pressure vessel with independent controls on pore and confining pressure. Application of this technique to samples of Franciscan graywacke from The Geysers reveals a significant change in thermal conductivity with temperature. At reservoir-equivalent temperatures of 250 °C, the conductivity of the graywacke decreases by approximately 25% relative to the room temperature value. Where heat flow is constant with depth within the caprock overlying the reservoir, this reduction in conductivity with temperature leads to a corresponding increase in the geothermal gradient. Consequently, reservoir temperature are encountered at depths significantly shallower than those predicted by assuming a constant temperature gradient with depth. We have derived general equations for estimating the thermal conductivity of most metamorphic and igneous rocks and some sedimentary rocks at elevated temperature from knowledge of the room temperature thermal conductivity. Application of these equations to geothermal exploration should improve estimates of subsurface temperatures derived from heat flow measurements.

Williams, Colin F.; Sass, John H.

1996-01-24T23:59:59.000Z

47

Effect of Aggregation on Thermal Conduction in Colloidal Nanofluids  

SciTech Connect (OSTI)

Using effective medium theory we demonstrate that the thermal conductivity of nanofluids can be significantly enhanced by the aggregation of nanoparticles into clusters. The enhancement is based purely on conduction and does not require a novel mechanism. Predictions of the effective medium theory are in excellent agreement with detailed numerical calculations on model nanofluids involving fractal clusters and show the importance of cluster morphology on thermal conductivity enhancements.

R Prasher; W Evans; J Fish; P Meakin; P Phelan; Pawel Keblinski

2006-08-10T23:59:59.000Z

48

Nonlocal probes of thermalization in holographic quenches with spectral methods  

E-Print Network [OSTI]

We describe the application of pseudo-spectral methods to problems of holographic thermal quenches of relevant couplings in strongly coupled gauge theories. We focus on quenches of a fermionic mass term in a strongly coupled N=4 supersymmetric Yang-Mills plasma, and the subsequent equilibration of the system. From the dual gravitational perspective, we study gravitational collapse of a massive scalar field in asymptotically anti-de-Sitter geometry with a prescribed boundary condition for its non-normalizable mode. Access to the full background geometry of the gravitational collapse allows for the study of nonlocal probes of the thermalization process. We discuss the evolution of the apparent and the event horizons, the two-point correlation functions of operators of large conformal dimensions, and the evolution of the entanglement entropy of the system. We compare the thermalization process from the viewpoint of local (the one-point) correlation functions and these nonlocal probes, finding that the thermalization time as measured by the probes is length dependent, and can exceed that of the one-point function. We further discuss how the different energy scales of the problem contribute to its thermalization.

Alex Buchel; Robert C. Myers; Anton van Niekerk

2014-10-22T23:59:59.000Z

49

Thermal conductivity of beryllium-gas packed bed  

SciTech Connect (OSTI)

Unsintered packed bed has been suggested as a material form for solid breeder and multiplier in the ITER and fusion power reactor blankets. Study of the effective bed thermal conductivity can provide tools for analysis of the blanket performance under different operating conditions, and of how to actively control the thermal behavior of the blanket. Issues of particular interest are the ability to predict and to control the thermal conductivity. The 2-D model developed at UCLA is used to study the effect of particle diameter, solid-to-gas conductivity ratio, bed porosity, contact area, and surface roughness characteristics on bed thermal conductivity. The study shows that all parameters except bed porosity play important roles in determining the bed thermal controllability.

Xu, M.; Abdou, M.A.; Raffray, A.R. [Univ. of California, Los Angeles, CA (United States)

1994-12-31T23:59:59.000Z

50

HIGH TEMPERATURE CONDUCTIVITY PROBE FOR MONITORING CONTAMINATION LEVELS IN POWER PLANT BOILER WATER.  

E-Print Network [OSTI]

??A high temperature/high pressure flow through probe was designed to measure high temperature electrical conductivity of aqueous (aq) dilute electrolyte solutions, an application which can… (more)

Hipple, Sarah

2008-01-01T23:59:59.000Z

51

In-Pile Thermal Conductivity Measurement Method for Nuclear Fuels  

SciTech Connect (OSTI)

Thermophysical properties of advanced nuclear fuels and materials during irradiation must be known prior to their use in existing, advanced, or next generation reactors. Thermal conductivity is one of the most important properties for predicting fuel and material performance. A joint Utah State University (USU) / Idaho National Laboratory (INL) project, which is being conducted with assistance from the Institute for Energy Technology at the Norway Halden Reactor Project, is investigating in-pile fuel thermal conductivity measurement methods. This paper focuses on one of these methods – a multiple thermocouple method. This two-thermocouple method uses a surrogate fuel rod with Joule heating to simulate volumetric heat generation to gain insights about in-pile detection of thermal conductivity. Preliminary results indicated that this method can measure thermal conductivity over a specific temperature range. This paper reports the thermal conductivity values obtained by this technique and compares these values with thermal property data obtained from standard thermal property measurement techniques available at INL’s High Test Temperature Laboratory. Experimental results and material properties data are also compared to finite element analysis results.

Joy L. Rempe; Brandon Fox; Heng Ban; Joshua E. Daw; Darrell L. Knudson; Keith G. Condie

2009-08-01T23:59:59.000Z

52

Fabrication and Characterization of a Conduction Cooled Thermal Neutron Filter  

SciTech Connect (OSTI)

Installation of a conduction cooled thermal (low-energy) neutron filter in an existing domestic test reactor would provide the U.S. the capability to test new reactor fuels and materials for advanced fast (high-energy) reactor concepts. A composite consisting of Al3Hf-Al has been proposed for the neutron filter due to both the neutron filtering properties of hafnium and the conducting capabilities of aluminum. Knowledge of the thermal conductivity of the Al3Hf-Al composite is essential for the design of the filtering system. The present objectives are to identify a suitable fabrication technique and to measure the thermophysical properties of the Al3Hf intermetallic, which has not been done previous to this study. A centrifugal casting method was used to prepare samples of Al3Hf. X-ray diffraction and Rietveld analysis were conducted to determine the structural make-up of each of the samples. Thermophysical properties were measured as follows: specific heat by a differential scanning calorimeter (DSC), thermal diffusivity by a laser flash thermal diffusivity measuring system, thermal expansion by a dilatometer, and thermal conductivity was calculated based on the previous measurements. All measurements were acquired over a temperature range of 90°C - 375°C with some measurements outside these bounds. The average thermal conductivity of the intermetallic Al3Hf (~7 at.% Hf) was found to be ~ 41 W/m-K for the given temperature range. This information fills a knowledge gap in the thermophysical properties of the intermetallic Al3Hf with the specified percentage of hafnium. A model designed to predict composite properties was used to calculate a thermal conductivity of ~177 W/m-K for an Al3Hf-Al composite with 23 vol% Al3Hf. This calculation was based upon the average thermal conductivity of Al3Hf over the specified temperature range.

Heather Wampler; Adam Gerth; Heng Ban; Donna Post Guillen; Douglas Porter; Cynthia Papesch

2010-06-01T23:59:59.000Z

53

Fiber/Matrix Interfacial Thermal Conductance Effect on the Thermal Conductivity of SiC/SiC Composites  

SciTech Connect (OSTI)

SiC/SiC composites used in fusion reactor applications are subjected to high heat fluxes and require knowledge and tailoring of their in-service thermal conductivity. Accurately predicting the thermal conductivity of SiC/SiC composites as a function of temperature will guide the design of these materials for their intended use, which will eventually include the effects of 14-MeV neutron irradiations. This paper applies an Eshelby-Mori-Tanaka approach (EMTA) to compute the thermal conductivity of unirradiated SiC/SiC composites. The homogenization procedure includes three steps. In the first step EMTA computes the homogenized thermal conductivity of the unidirectional (UD) SiC fiber embraced by its coating layer. The second step computes the thermal conductivity of the UD composite formed by the equivalent SiC fibers embedded in a SiC matrix, and finally the thermal conductivity of the as-formed SiC/SiC composite is obtained by averaging the solution for the UD composite over all possible fiber orientations using the second-order fiber orientation tensor. The EMTA predictions for the transverse thermal conductivity of several types of SiC/SiC composites with different fiber types and interfaces are compared to the predicted and experimental results by Youngblood et al.

Nguyen, Ba Nghiep; Henager, Charles H.

2013-04-20T23:59:59.000Z

54

Nanoscale thermal transport and the thermal conductance of interfaces  

E-Print Network [OSTI]

-8 2008 #12;Er-fiber laser system, UIUC Nov. 2007 #12;Solid-liquid interfaces: Two approaches · Transient-wide: ­ thermal interface materials ­ so-called "nanofluids" (suspensions in liquids) ­ polymer composites absorption depends on temperature of the nanotube · Assume heat capacity is comparable to graphite · Cooling

Braun, Paul

55

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

E-Print Network [OSTI]

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

Kjelstrup, Signe

56

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

Open Energy Info (EERE)

Study Of A 2-Layer Transient Thermal Conduction Problem As Applied To Soil-Temperature Surveys Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

57

A benchmark study on the thermal conductivity of nanofluids  

E-Print Network [OSTI]

This article reports on the International Nanofluid Property Benchmark Exercise, or INPBE, in which the thermal conductivity of identical samples of colloidally stable dispersions of nanoparticles or “nanofluids,” was ...

Buongiorno, Jacopo

58

Investigation on thermal conductivity and AC impedance of graphite suspension  

E-Print Network [OSTI]

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 ...

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

2011-01-01T23:59:59.000Z

59

Resonant bonding leads to low lattice thermal conductivity  

E-Print Network [OSTI]

Understanding the lattice dynamics and low thermal conductivities of IV–VI, V[subscript 2]–VI[subscript 3] and V materials is critical to the development of better thermoelectric and phase-change materials. Here we provide ...

Lee, Sangyeop

60

The thermal conductivity of sediments as a function of porosity  

E-Print Network [OSTI]

1979 Major Subject: Civil Engineering THE THERMAL CONDUCTIVITY OF SEDIMENTS AS A FUNCTION OF POROSITY A Thesis by JAMES WARREN MILLER Approved as to style and content by: Louis J. hompson CE)(Chairman of Committee) Harry M. Coyle (CE)( ember...THE THERMAL CONDUCTIVITY OF SEDIMENTS AS A FUNCTION OF POROSITY A Thesis by JAMES WARREN MILLER Submitted to the Graduate College of Texas AAM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August...

Miller, James W

1979-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Modeling the thermal conductivity of fiber-reinforced ceramic composites  

SciTech Connect (OSTI)

A review of models for the prediction of the thermal conductivity of uni-directional fiber-reinforced composites will be presented. The ability of these models to give an accurate prediction of the composite thermal conductivity depends on the amount of information known about the constituent phase properties under the assumption that these properties do not change as a result of processing. Also presented are models that take into account the effects of fiber coatings.

Beecher, S.C.; Dinwiddie, R.B.

1993-06-01T23:59:59.000Z

62

Metallic coatings for enhancement of thermal contact conductance  

SciTech Connect (OSTI)

The reliability of standard electronic modules may be improved by decreasing overall module temperature. This may be accomplished by enhancing the thermal contact conductance at the interface between the module frame guide rib and the card rail to which the module is clamped. Some metallic coatings, when applied to the card rail, would deform under load, increasing the contact area and associated conductance. This investigation evaluates the enhancements in thermal conductance afforded by vapor deposited silver and gold coatings. Experimental thermal conductance measurements were made for anodized aluminum 6101-T6 and electroless nickel-plated copper C11000-H03 card materials to the aluminum A356-T61 rail material. Conductance values for the electroless nickel-plated copper junction ranged from 600 to 2800 W/m(exp 2)K and those for the anodized aluminum junction ranged from 25 to 91 W/m(exp 2)K for contact pressures of 0.172-0.862 MPa and mean junction temperatures of 20-100 C. Experimental thermal conductance values of vapor deposited silver- and gold-coated aluminum A356-T61 rail surfaces indicate thermal enhancements of 1.25-2.19 for the electroless nickel-plated copper junctions and 1.79-3.41 for the anodized aluminum junctions. The silver and gold coatings provide significant thermal enhancement; however, these coating-substrate combinations are susceptible to galvanic corrosion under some conditions. 25 refs.

Lambert, M.A.; Fletcher, L.S. (Texas A M Univ., College Station, TX (United States))

1994-04-01T23:59:59.000Z

63

THERMAL CONDUCTIVITY OF NON-REPOSITORY LITHOSTRATIGRAPHIC LAYERS  

SciTech Connect (OSTI)

This model report addresses activities described in ''Technical Work Plan for: Near-Field Environment and Transport Thermal Properties and Analysis Reports Integration'' (BSC 2004 [DIRS 171708]). The model develops values for thermal conductivity, and its uncertainty, for the nonrepository layers of Yucca Mountain; in addition, the model provides estimates for matrix porosity and dry bulk density for the nonrepository layers. The studied lithostratigraphic units, as identified in the ''Geologic Framework Model'' (GFM 2000) (BSC 2004 [DIRS 170029]), are the Timber Mountain Group, the Tiva Canyon Tuff, the Yucca Mountain Tuff, the Pah Canyon Tuff, the Topopah Spring Tuff (excluding the repository layers), the Calico Hills Formation, the Prow Pass Tuff, the Bullfrog Tuff, and the Tram Tuff. The deepest model units of the GFM (Tund and Paleozoic) are excluded from this study because no data suitable for model input are available. The parameter estimates developed in this report are used as input to various models and calculations that simulate heat transport through the rock mass. Specifically, analysis model reports that use product output from this report are: (1) Drift-scale coupled processes (DST and TH seepage) models; (2) Drift degradation analysis; (3) Multiscale thermohydrologic model; and (4) Ventilation model and analysis report. In keeping with the methodology of the thermal conductivity model for the repository layers in ''Thermal Conductivity of the Potential Repository Horizon'' (BSC 2004 [DIRS 169854]), the Hsu et al. (1995 [DIRS 158073]) three-dimensional (3-D) cubic model (referred to herein as ''the Hsu model'') was used to represent the matrix thermal conductivity as a function of the four parameters (matrix porosity, thermal conductivity of the saturating fluid, thermal conductivity of the solid, and geometric connectivity of the solid). The Hsu model requires input data from each test specimen to meet three specific conditions: (1) Known value for matrix porosity; (2) Known values for wet and dry thermal conductivity; and (3) The location of the measured specimen in relation to the model stratigraphic unit. The only matrix thermal conductivity values developed are limited to fully saturated and dry conditions. The model does not include the effects of convection and thermal radiation in voids. The model does not include temperature dependence of thermal conductivity, porosity, or bulk density.

R. JONES

2004-10-22T23:59:59.000Z

64

An International Round-Robin Study, Part II: Thermal Diffusivity, Specific Heat and Thermal Conductivity  

SciTech Connect (OSTI)

For bulk thermoelectrics, figure-of-merit, ZT, still needs to improve from the current value of 1.0 - 1.5 to above 2 to be competitive to other alternative technologies. In recent years, the most significant improvements in ZT were mainly due to successful reduction of thermal conductivity. However, thermal conductivity cannot be measured directly at high temperatures. The combined measurements of thermal diffusivity and specific heat and density are required. It has been shown that thermal conductivity is the property with the greatest uncertainty and has a direct influence on the accuracy of the figure of merit. The International Energy Agency (IEA) group under the implementing agreement for Advanced Materials for Transportation (AMT) has conducted two international round-robins since 2009. This paper is Part II of the international round-robin testing of transport properties of bulk bismuth telluride. The main focuses in Part II are on thermal diffusivity, specific heat and thermal conductivity.

Wang, Hsin [ORNL; Porter, Wallace D [ORNL; Bottner, Harold [Fraunhofer-Institute, Freiburg, Germany; Konig, Jan [Fraunhofer-Institute, Freiburg, Germany; Chen, Lidong [Chinese Academy of Sciences; Bai, Shengqiang [Chinese Academy of Sciences; Tritt, Terry M. [Clemson University; Mayolett, Alex [Corning, Inc; Senawiratne, Jayantha [Corning, Inc; Smith, Charlene [Corning, Inc; Harris, Fred [ZT-Plus; Gilbert, Partricia [Marlow Industries, Inc; Sharp, J [Marlow Industries, Inc; Lo, Jason [CANMET - Materials Technology Laboratory, Natural Resources of Canada; Keinke, Holger [University of Waterloo, Canada; Kiss, Laszlo I. [University of Quebec at Chicoutimi

2013-01-01T23:59:59.000Z

65

Process for fabricating composite material having high thermal conductivity  

DOE Patents [OSTI]

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.

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

2001-01-01T23:59:59.000Z

66

Lattice thermal conductivity of nanograined half-Heusler solid solutions  

SciTech Connect (OSTI)

We report a phenomenological model of atomic weight, lattice constant, temperature, and grain size to calculate the high-temperature lattice thermal conductivity of nanograined solid solutions. The theoretical treatment developed here is reasonably consistent with the experimental results of n-type MNiSn and p-type MCoSb alloys, where M is the combination of Hf, Zr, and Ti. For disordered half-Heusler alloys with moderated grain sizes, we predict that the reduction in lattice thermal conductivity due to grain boundary scattering is independent of the scattering parameter, which characterizes the phonon scattering cross section of point defects. In addition, the lattice thermal conductivity falls off with temperature as T{sup –1?2} around the Debye temperature.

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)

2014-05-19T23:59:59.000Z

67

Thermally conductive cementitious grout for geothermal heat pump systems  

DOE Patents [OSTI]

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.

Allan, Marita (Old Field, NY)

2001-01-01T23:59:59.000Z

68

Thermal conductivity of highly-ordered mesoporous titania thin films from 30 to 320 K  

E-Print Network [OSTI]

Thermal resistance of grain boundaries in alumina ceramicsThermal conductivity of highly porous zirconia”. Journal of the European Ceramic

2011-01-01T23:59:59.000Z

69

High thermal conductivity lossy dielectric using a multi layer configuration  

DOE Patents [OSTI]

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.

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

2003-01-01T23:59:59.000Z

70

Thermal conduction of SSC (Superconducting Super Collider) wire  

SciTech Connect (OSTI)

A method suitable for measuring the thermal conductivity of good thermal conductors at low temperatures was implemented. It successfully served its purpose: to detect the effect of doping with manganese the interfilament part of the copper matrix of the superconducting wire used in the magnets of the Superconducting Super Collider. It uses two heaters and one thermometer per sample reducing the accuracy requirement on the thermometers, automatically compensating for zero offsets and reducing the number of critical thermal contacts. Commercially available strain gauges are used as heaters. 3 refs., 2 figs.

Kuchnir, M.; Tague, J.L.

1989-08-01T23:59:59.000Z

71

Developing a High Thermal Conductivity Fuel with Silicon Carbide Additives  

SciTech Connect (OSTI)

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:

Ronald baney; James Tulenko

2012-11-20T23:59:59.000Z

72

Remarkable Reduction of Thermal Conductivity in Silicon Nanotubes  

E-Print Network [OSTI]

localization, thermoelectric material T hermoelectric (TE) materials can provide electricity when subjected materials can be characterized by the dimen- sionless thermoelectric figure of merit ZT ) S2 T/, where S to be responsible for the reduction of thermal conductivity. Our study suggests SiNT is a promising thermoelectric

Li, Baowen

73

Thermal Conductivity of Composites Under Di erent Heating Scenarios  

E-Print Network [OSTI]

Thermal Conductivity of Composites Under Di#11;erent Heating Scenarios H.T. Banks #3; , J.H. Hogan of composites under three di#11;erent heating scenarios: (i) a laser pulse heat source, (ii) a preheated composite sample, and (iii) a continuous heat source. 1 Introduction Adhesives such as epoxies, gels

74

Mode dependent lattice thermal conductivity of single layer graphene  

SciTech Connect (OSTI)

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.

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)

2014-10-21T23:59:59.000Z

75

Heat conduction through a trapped solid: effect of structural changes on thermal conductance  

E-Print Network [OSTI]

We study the conduction of heat across a narrow solid strip trapped by an external potential and in contact with its own liquid. Structural changes, consisting of addition and deletion of crystal layers in the trapped solid, are produced by altering the depth of the confining potential. Nonequilibrium molecular dynamics simulations and, wherever possible, simple analytical calculations are used to obtain the thermal resistance in the liquid, solid and interfacial regions (Kapitza or contact resistance). We show that these layering transitions are accompanied by sharp jumps in the contact thermal resistance. Dislocations, if present, are shown to increase the thermal resistance of the strip drastically.

Debasish Chaudhuri; Abhishek Chaudhuri; Surajit Sengupta

2007-03-20T23:59:59.000Z

76

Thermal Crosslinking of Organic Semiconducting Polythiophene Improves Transverse Hole Conductivity  

SciTech Connect (OSTI)

Thermal crosslinking using a suitable radical initiator simultaneously improves electrical conductivity in the semiconducting polymer poly(3-hexylthiophene) and makes the material insoluble. Crosslinked polythiophene shows as much as a fivefold increase in hole conductivity across the film thickness without any shift in spectral light absorption. Grazing incidence x-ray diffraction reveals more in-plane polymer lamellae stacking with only a small decrease in film crystallinity. Improved transverse conductivity increases the performance of model planar solar cells by threefold, from 0.07% to 0.2%. The ability to render polythiophene insoluble without disrupting film structural order enables fabrication pathways to more complex device architectures.

Gearba, I.R.; Nam, C.-Y.; Pindak, R.; Black, C.T.

2009-10-26T23:59:59.000Z

77

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recovery challenge fund Las Conchas recoveryNuclearPhysicist honored

78

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

SciTech Connect (OSTI)

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.

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

2014-09-01T23:59:59.000Z

79

Determination of Thermal Diffusivities, Thermal Conductivities, and Sound Speeds of Room-Temperature Ionic Liquids by the Transient Grating Technique  

E-Print Network [OSTI]

Determination of Thermal Diffusivities, Thermal Conductivities, and Sound Speeds of Room. The experiments give thermal diffusivities from which thermal conductivities can be determined, sound speeds not only on the sound speed but also on the thermal diffusivity and acoustic damping of the RTILs

Reid, Scott A.

80

VALIDATION OF A THERMAL CONDUCTIVITY MEASUREMENT SYSTEM FOR FUEL COMPACTS  

SciTech Connect (OSTI)

A high temperature guarded-comparative-longitudinal heat flow measurement system has been built to measure the thermal conductivity of a composite nuclear fuel compact. It is a steady-state measurement device designed to operate over a temperature range of 300 K to 1200 K. No existing apparatus is currently available for obtaining the thermal conductivity of the composite fuel in a non-destructive manner due to the compact’s unique geometry and composite nature. The current system design has been adapted from ASTM E 1225. As a way to simplify the design and operation of the system, it uses a unique radiative heat sink to conduct heat away from the sample column. A finite element analysis was performed on the measurement system to analyze the associated error for various operating conditions. Optimal operational conditions have been discovered through this analysis and results are presented. Several materials have been measured by the system and results are presented for stainless steel 304, inconel 625, and 99.95% pure iron covering a range of thermal conductivities of 10 W/m*K to 70 W/m*K. A comparison of the results has been made to data from existing literature.

Jeff Phillips; Colby Jensen; Changhu Xing; Heng Ban

2011-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

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

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

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.

Cable, William; Romanovsky, Vladimir

82

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

SciTech Connect (OSTI)

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.

Cable, William; Romanovsky, Vladimir

2014-03-31T23:59:59.000Z

83

Lattice thermal conductivity of filled skutterudites: An anharmonicity perspective  

SciTech Connect (OSTI)

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.

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)

2014-10-28T23:59:59.000Z

84

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

E-Print Network [OSTI]

both the United States Department of Energy and Texas Advanced Research Program. vi NOMENCLATURE D Thermal diffusivity Ei Exponential integral k Thermal conductivity k n Nanofluid thermal conductivity k b Base fluid thermal...?s thermal conductivity (k) and thermal diffusivity (D), are related to the temperature difference null?nullnull between the heat source and surrounding medium at a distance (r) from the source of a quantity of heat (Q) a certain time (t) after the heat...

Fortenberry, Stephen

2009-09-30T23:59:59.000Z

85

eXtremes of heat conduction: Pushing the boundaries of the thermal  

E-Print Network [OSTI]

eXtremes of heat conduction: Pushing the boundaries of the thermal conductivity of materials David. · For example, simplest case of thermal conductivity where resistive scattering dominates C() v() l() d C for the highest thermal conductivity any material (higher conductivity than diamond) Yu et al. (2005) Maruyama

Braun, Paul

86

High-Throughput Computational Screening of thermal conductivity, Debye temperature and Gruneisen parameter  

E-Print Network [OSTI]

thermal properties such as the Debye temperature and the thermal conductivity of materials. We demonstrate studied for the past few decades6 . Low thermal conductivity mate- rials constitute the basis of a new and predict the thermal conductivity of differ- ent materials8,9,11­16 . Such evaluation of the higher

Curtarolo, Stefano

87

Enhanced thermal conductivity and viscosity of copper nanoparticles in ethylene glycol nanofluid  

E-Print Network [OSTI]

by their very low thermal conductivity. These fluids have almost two orders of magnitude lower thermal, a significant amount of data has been gathered on the thermal conductivity of nanofluids. Typical materials usedEnhanced thermal conductivity and viscosity of copper nanoparticles in ethylene glycol nanofluid J

88

E-Print Network 3.0 - apparent thermal conductivity Sample Search...  

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

293 K. To obtain data... results 4,5. Comparing to the apparent thermal conductivity of aerogel when the boundary temperatures... THERMAL ... Source: Chang, Ho-Myung - Department...

89

E-Print Network 3.0 - angle-resolved thermal conductivity Sample...  

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

single-walled carbon nanotube films Kei... , the expectation on single-walled carbon nanotubes (SWNTs) to possess high thermal conductivity has attracted... of the thermal...

90

Submitted to Phys. Rev. B, June 2013 Ultralow thermal conductivity of fullerene derivatives  

E-Print Network [OSTI]

conductivity in WSe2. The objective our study is to verify the exceptionally low thermal conductivities of these materials might affect their thermal conductivities. In addition to PCBM, we also investigate [6,6]-phenyl on the appearance of ultralow thermal conductivity in this class of materials. We use time-domain thermoreflectance

Cahill, David G.

91

The Thermal Conductivity of Low Density Concretes Containing Perlite  

E-Print Network [OSTI]

-Tov, "HEATING5 - An IBM 360 Heat Conduction Program," ORNL/CSD/tm-15(1977). Oak Ridge National Laboratory, Oak Ridge, TN 37831. [5J Expanded Shale Clay and Slate Institute, "Lightweight Concrete Information Sheet," No.4, Washington, D.C., 1958. [6J Moore..., J. P., R. S. Graves, J. G. Stradley, J. H. Hannah, and D. L. McElroy, "Some Thermal Transport Properties of a Limestone Concrete," ORNL/TM-2644 (August 1969), Oak Ridge National Laboratory, Oak Ridge, TN 37831. [7J Valore, R. C., Jr., "Cellular...

Yarbrough, D. W.

92

Effective thermal conductivity of packed beds of spheres  

E-Print Network [OSTI]

of N are known only for certain types of regular packing, however, an empirical relation for m ) 0. 3 is given as N = 11. 6(l ? m) (22) When a load is applied to a bed of spheres, the contact area between spheres is determined using the Hertz... the authors compared their analytical solutions to has consistently dealt with beds of materials which have a very low thermal conductivity compared to that of the brass and aluminum spheres. These materials have been solid and hollow glass spheres, ceramic...

Duncan, Allen Buchanan

1987-01-01T23:59:59.000Z

93

Experimental Investigation of Size Effects on the Thermal Conductivity of Silicon-Germanium Alloy Thin Films  

E-Print Network [OSTI]

We experimentally investigate the role of size effects and boundary scattering on the thermal conductivity of silicon-germanium alloys. The thermal conductivities of a series of epitaxially grown Si[subscript 1-x] Ge[subscript ...

Cheaito, Ramez

94

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

E-Print Network [OSTI]

NY: Taylor & Francis. [10] Tritt, T. M. (2004). MeasurementBulk Materials. In T. M. Tritt, Thermal Conductivity Theory,

Louie, Brian Ming

2011-01-01T23:59:59.000Z

95

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

E-Print Network [OSTI]

transform fully dense solids into ultralow thermal conductivity materials. Here we report a simple self of nanolaminate spacing. A simple series resistance model describes the behavior and gives an interfacial thermal thermal conductance For phonon-mediated heat conduction, a material is generally thought to reach its

Braun, Paul

96

Anomalous thermal conduction characteristics of phase change composites with single walled carbon nanotube inclusions  

E-Print Network [OSTI]

of the phase change materials, because low thermal conductivity hinders the rate of energy storage and release of the new way of improving the thermal conductivity of phase change materials by seeding nano materials way to manipulate the thermal conductivity of nano composites using one dimensional nano material

Maruyama, Shigeo

97

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

E-Print Network [OSTI]

, the thermal conductivity of UO2 is very low, and the search for alternative materials continuesOrigin of Low Thermal Conductivity in Nuclear Fuels Quan Yin and Sergey Y. Savrasov Department in a very low thermal conductivity of modern nuclear fuels. Consider semiconducting UO2 which is a main

Savrasov, Sergej Y.

98

Calibration of magnetic probes in the vicinity of a conducting well  

SciTech Connect (OSTI)

Measuring magnetic fields near the edge of a plasma device can be complicated by the geometric effects of the ports through which such measurements are made. The primary effect is an attenuation of the magnetic field at the probe coil due to the field expanding into the finite sized conducting well of the port. In addition, it is possible to determine the correspondence between the location of a field line as it intersects the probe coil inside the well, with its location far from the perturbation of the well. Here we explore several methods of experimentally characterizing the magnetic fields in the vicinity of the magnetic probe ports of a vacuum vessel, with the aim of improving the interpretation of magnetic measurements needed for experiments in plasma physics.

Howard, S. J.; Horton, R. D.; Hwang, D. Q.; Evans, R. W.; Brockington, S. J. [Department of Applied Science, UC Davis, Livermore, California 94550 (United States)

2008-02-15T23:59:59.000Z

99

Spatially localized measurement of thermal conductivity using a hybrid photothermal technique  

SciTech Connect (OSTI)

A photothermal technique capable of measuring thermal conductivity with micrometer lateral resolution is presented. This technique involves measuring separately the thermal diffusivity, D, and thermal effusivity, e, to extract the thermal conductivity, k=(e2/D)1/2. To generalize this approach, sensitivity analysis was conducted for materials having a range of thermal conductivities. Experimental validation was sought using two substrate materials, SiO2 and CaF2, both coated with thin titanium films. The measured conductivities compare favorably with literature values.

David H Hurley; Marat Khafizov; Zilong Hua; Rory Kennedy; Heng Ban

2012-05-01T23:59:59.000Z

100

Universal conductance fluctuations as a direct probe to valley coherence and universality class of disordered graphene  

SciTech Connect (OSTI)

We demonstrate that the universal conductance fluctuations (UCF) can be used as a direct probe to study the valley quantum states in disordered graphene. The UCF magnitude in graphene is suppressed by a factor of four at high carrier densities where the short-range disorder essentially breaks the valley degeneracy of the K and K' valleys, leading to a density dependent crossover of symmetry class from symplectic near the Dirac point to orthogonal at high densities.

Kochat, Vidya; Pal, Atindra Nath; Ghosh, Arindam [Department of Physics, Indian Institute of Science, Bangalore 560 012 (India)

2013-12-04T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Ballistic phonon thermal conductance in graphene nano-ribbon: First-principles calculations  

SciTech Connect (OSTI)

Ballistic phonon thermal conductances for graphene nanoribbons are investigated using first-principles calculations with the density functional perturbation theory and the Landauer theory. The phonon thermal conductance per unit width for GNR is larger than that for graphene and increases with decreasing ribbon width. The normalized thermal conductances with regard to a thermal quantum for GNRs are higher than those for the single-walled carbon nanotube that have circumferential lengths corresponding to the width of GNR.

Nakamura, Jun; Tomita, Hiroki [Department of Engineering Sciences, The University of Electro-Communications (UEC-Tokyo), 1-5-1 Chofugaoka, Chofu, Tokyo 182-8585 (Japan)

2013-12-04T23:59:59.000Z

102

MODEL FOR DETERMINING THE EFFECTIVE THERMAL CONDUCTIVITY OF PARTICLE BEDS WITH HIGH SOLID-TO-GAS THERMAL  

E-Print Network [OSTI]

-TO-GAS THERMAL CONDUCTIVITY RATIO A.R. Raffray, Z. Gorbis, A. Badawi, M.S. Tillack, A.Y. Ying, and M. A. Abdou

Abdou, Mohamed

103

Real-time crystallization in fluorinated parylene probed by conductivity spectra  

SciTech Connect (OSTI)

Dielectric relaxation spectroscopy experiments were performed at high temperature on fluorinated parylene films during the occurrence of the isothermal crystalline phase transition. For this polymer, since the difference between the glass transition temperature (T{sub g}) and the phase transition temperature (T{sub c}) is very strong (T{sub c}???4T{sub g}), segmental and dipolar relaxation usually used to probe the crystallization are not shown in the experiment frequency window (10{sup ?1} to 10{sup 6}?Hz) during the crystallization. The charge diffusion becomes the only electrical marker that allows probing the phase transition. During the transition phase, a continuous decrease of about two orders of magnitude is observed in the conductivity values below an offset frequency (f{sub c}) with a tendency to stabilization after 600?min. Below the offset frequency, the decrease of the normalized conductivity to the initial value as function of time is frequency independent. The same behavior is also observed for the f{sub c} values that decrease from 160?Hz to about 20?Hz. Above the offset frequency, the electronic hopping mechanism is also affected by the phase transition and the power law exponent (n) of the AC conductivity shows a variation from 0.7 to 0.95 during the first 600?min that tend to stabilize thereafter. Accordingly, three parameters (n, f{sub c}, and AC conductivity values for frequencies below f{sub c}) extracted from the AC conductivity spectra in different frequency windows seem suitable to probe the crystalline phase transition.

Khazaka, R., E-mail: rabih.khazaka@laplace.univ-tlse.fr; Diaham, S. [Université de Toulouse, UPS, INPT, Laboratoire LAPLACE, 118 route de Narbonne, F-31062 Toulouse (France); Locatelli, M. L. [Université de Toulouse, UPS, INPT, Laboratoire LAPLACE, 118 route de Narbonne, F-31062 Toulouse (France); CNRS, LAPLACE, F-31062 Toulouse (France); Tenailleau, C. [Université de Toulouse, UPS, Laboratoire CIRIMAT/LCMIE, 118 route de Narbonne - Bât. 2R1, F-31062 Toulouse cedex 9 (France); Kumar, R. [Speciality Coating Systems, Inc. (SCS), Cookson Electronics, 7645 Woodland Drive, Indianapolis, Indiana 46278 (United States)

2014-03-17T23:59:59.000Z

104

ENS'07 Paris, France, 3-4 December 2007 MEASUREMENTS OF THERMAL CONDUCTIVITY OF ALUMINUM NANOPOWDERS  

E-Print Network [OSTI]

ENS'07 Paris, France, 3-4 December 2007 MEASUREMENTS OF THERMAL CONDUCTIVITY OF ALUMINUM spectroscopy (PAS) as a powerful technique to estimate thermal properties of aluminum nanosized powders. Aluminum nanopowders are considered as effective constituents of energetic materials. Thermal conductivity

Paris-Sud XI, Université de

105

INFLUENCE OF ANISOTROPIC THERMAL CONDUCTIVITY IN THE APPARATUS INSULATION FOR SUBLIMATION GROWTH OF SIC  

E-Print Network [OSTI]

INFLUENCE OF ANISOTROPIC THERMAL CONDUCTIVITY IN THE APPARATUS INSULATION FOR SUBLIMATION GROWTH insulation for sublimation growth of SiC: Numerical investigation of heat transfer J¨urgen Geiser, Olaf Klein). As it is not unusual for the thermal insulation of PVT growth apparatus to possess an anisotropic thermal conductivity

106

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

E-Print Network [OSTI]

to solid materials like metals. Keywords: SWNT, Random Walk, Thermal Conductivity, Composites 1 at the interface between the matrix material and the SWNT plays a very important role on the effective thermal conductivity. This thermal resistance is known as the Kapitza resistance [8]. According to the acoustic theory

Maruyama, Shigeo

107

Thermal conductivity measurements of insulators for fusion blankets  

SciTech Connect (OSTI)

Alumina-silica mat (8 lb/ft/sup 3/) varied in thermal conductivity in air and Ar from 0.06 W/m- K at 300/sup 0/C to 0.22 W/m- K at 1000/sup 0/C, but in He it increased to 0.24 W/m- K at 300/sup 0/C and 0.54 W/m- K at 1000/sup 0/C, while in steam it was about midway between these values. The carbon and graphite felts behaved similarly, but the rigid and denser (24 lb/ft/sup 3/) zirconia fiberboard exhibited superior insulating properties: 0.07 W/m- K at 300/sup 0/C and 0.14 W/m- K at 1000/sup 0/C in air and Ar, and 0.13 W/m- K at 300/sup 0/C and 0.17 W/m- K at 1000/sup 0/C in steam, but rising to 0.15 W/m- K at 300/sup 0/C and 0.49 W/m- K at 1000/sup 0/C in He. The lighter zirconia felt (14 lb/ft/sup 3/) in steam at 1000/sup 0/C was thought to be best at 0.23 W/m- K and only 0.40 W/m- K in He at 1000/sup 0/C.

Horn, F.L.; Fillo, J.A.; Powell, J.R.

1981-01-01T23:59:59.000Z

108

Thermal conductance of buckled carbon nanotubes Fumio Nishimura1  

E-Print Network [OSTI]

with the strain energy generated in the buckle. Despite the highly stained deformation, the thermal resistance have motivated applications of carbon nanotubes as thermal interface materials [4-8] and additives in nanocomposites [9-12], in practice, one needs to consider various thermal resistances that manifest in the actual

Maruyama, Shigeo

109

Thermal Conduction Path Analysis in 3-D ICs Boris Vaisband1  

E-Print Network [OSTI]

in the temperature and thermal resistance of up to, respectively, 20% and 28%. As confirmed by simulation, those [9], [10]. Thermal flow in materials is described by the Fourier Law, q = -k · T . (1) Thermal-D stack. through a unit of area) q [ W m2 ], the thermal conductivity, a property of the material k

Friedman, Eby G.

110

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

E-Print Network [OSTI]

represents the length of a material of thermal conduc- tivity providing an equivalent thermal resistance inorganic materials and anharmonic polymers have potentially intriguing thermal transport behavior. The low. This requirement proves challenging for low thermal conductivity materials like amorphous polymers. The effective

Braun, Paul

111

Fractal-like tree networks reducing the thermal conductivity Boming Yu1,  

E-Print Network [OSTI]

Fractal-like tree networks reducing the thermal conductivity Boming Yu1, * and Baowen Li1,2 1 conductivity of composites with embedded self-similar H-shaped fractal-like tree networks is studied that the thermal conductivity of the H-shaped fractal-like tree networks does not obey Murray's law. The present

Li, Baowen

112

How Does Folding Modulate Thermal Conductivity of Graphene? Nuo Yang1,2  

E-Print Network [OSTI]

of thermal conductivity is due to scattering of low frequency phonons by the folds. Our results suggest dimensional materials. Keywords Folded graphene ribbon, thermal conductivity, phonon transport, scattering #12 conductivity of low-dimensional silicon and carbon materials11 and graphene ribbons12 were studied by EMD

Li, Baowen

113

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

DOE Patents [OSTI]

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.

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)

1992-01-01T23:59:59.000Z

114

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

DOE Patents [OSTI]

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.

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

1992-04-07T23:59:59.000Z

115

Size dependent thermal conductivity of single-walled carbon nanotubes Ajing Cao and Jianmin Qu  

E-Print Network [OSTI]

. Phys. Lett. 100, 261908 (2012) Focus shift photothermal method for thermal diffusivity mapping J. Appl Institute of Physics. Related Articles Enhanced high thermal conductivity and low permittivity of polyimide

Chen, Wei

116

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

E-Print Network [OSTI]

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 ...

Zheng, Ruiting

117

New equation calculates thermal conductivities of C[sub 1]-C[sub 4] gases  

SciTech Connect (OSTI)

In the design of heat exchangers, heat-transfer coefficients are commonly calculated for individual items. These calculations require knowledge of the thermal conductivities of the species involved. The calculation require knowledge of the thermal conductivities of the species involved. The calculation of the overall heat-transfer coefficient for a heat exchanger also requires thermal conductivity data for the individual species. In fact, thermal conductivity is the fundamental property involved in heat transfer. Ordinarily, thermal conductivities are either measured experimentally or estimated using complex correlations and models. Engineers must search existing literature for the values needed. Here, a compilation of thermal conductivity data for gases is presented for a wide temperature range. Using these data with the accompanying equation will enable engineers to quickly determine values at the desired temperatures. The results are provided in an easy-to-use tabular format, which is especially helpful for rapid calculations using a personal computer or hand-held calculator.

Yaws, C.L.; Lin, X.; Bu, L.; Nijhawan, S. (Lamar Univ., Beaumont, TX (United States))

1994-04-18T23:59:59.000Z

118

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

E-Print Network [OSTI]

line heat source method, the thermal con- ductivities of a jelly model (unflavored jelly), sugar solution and some commercial jelly products were measured. The studies were conducted in the temperature range from 25 to 95 'C. Thermal conductivity... were developed from experimental data for unflavored jelly and sugar solutions to predict the thermal conductivity of commercially available fruit jellies at various moisture contents. The predicted values obtained were statistically compared...

Chen, Yih-Rong

1985-01-01T23:59:59.000Z

119

Thermal conductivity, electrical resistivity, and permeability of saturated soils at various porosities  

E-Print Network [OSTI]

of Ottawa Sand . 4. Thermal Conductivity Data Analysis 5. Thermal Conductivity of Reference Materials 6. DC Resistivity Data with Plate Electrode System for Kaolinite at Porosity of 49% PAGE 48 52 54 66 71 AC Resistivity Data for Kaolinite... THERMAL CONDUCTIVITY, ELECTRICAL RESISTIVITY, AND PERMEABILITY OF SATURATED SOILS AT VARIOUS POROSITIES A Thesis by JAMES KEITH ENDERBY Submitted to the Graduate College of Texas ARM University in Partial fulfillment of the requirement...

Enderby, James Keith

2012-06-07T23:59:59.000Z

120

Thermal unfolding dynamics of proteins probed by nonlinear infrared spectroscopy  

E-Print Network [OSTI]

This thesis presents spectroscopic approaches to study the thermal unfolding dynamics of proteins. The spectroscopic tool is nonlinear infrared (IR) spectroscopy of the protein amide I band. Among various nonlinear IR ...

Chung, Hoi Sung

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

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

E-Print Network [OSTI]

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 ...

Miler, Josef L

2006-01-01T23:59:59.000Z

122

Enhanced Thermal Conductivity of Water with Surfactant Encapsulated and Individualized Single-Walled Carbon Nanotube Dispersions  

E-Print Network [OSTI]

.L, Review of heat conduction in nanofluids, Journal of Heat transfer, 2011, 133, pp 040801-1-040801-14. #12; layering were considered to be responsible for the thermal conductivity enhancement in the open literature

Maruyama, Shigeo

123

DDbar Correlations probing Thermalization in High-Energy Nuclear Collisions  

E-Print Network [OSTI]

We propose to measure azimuthal correlations of heavy-flavor hadrons to address the status of thermalization at the partonic stage of light quarks and gluons in high-energy nuclear collisions. In particular, we show that hadronic interactions at the late stage cannot significantly disturb the initial back-to-back azimuthal correlations of DDbar pairs. Thus, a decrease or the complete absence of these initial correlations does indicate frequent interactions of heavy-flavor quarks and also light partons in the partonic stage, which are essential for the early thermalization of light partons.

K. Schweda; X. Zhu; M. Bleicher; S. L. Huang; H. Stoecker; N. Xu; P. Zhuang

2006-10-30T23:59:59.000Z

124

Computational analysis of the thermal conductivity of the carboncarbon composite materials  

E-Print Network [OSTI]

Computational analysis of the thermal conductivity of the carbon­carbon composite materials M Abstract Experimental data for carbon­carbon con- stituent materials are combined with a three and longitudinal thermal conductivities in carbon­carbon composites. Particular attention is given in elucidating

Grujicic, Mica

125

Thermal conductivity of nitrogenated ultrananocrystalline diamond films M. Shamsa,1,a  

E-Print Network [OSTI]

, polycrystalline diamond PCD , diamondlike carbon DLC , carbon nanotubes, and single-layer graphene, have recentlyThermal conductivity of nitrogenated ultrananocrystalline diamond films on silicon M. Shamsa,1,a S of nitrogenated ultrananocrystalline diamond UNCD films on silicon. For better accuracy, the thermal conductivity

126

ENHANCED THERMAL CONDUCTIVITY IN NANOFLUIDS UNDER THE ACTION OF OSCILLATING FORCE FIELDS  

E-Print Network [OSTI]

. Active control of transport coefficients. Nanocolloïds. Cooling system Introduction Nanofluids (EastmanENHANCED THERMAL CONDUCTIVITY IN NANOFLUIDS UNDER THE ACTION OF OSCILLATING FORCE FIELDS Clément Le forces in the radio frequency and microwave ranges, we show that the thermal conductivity of nanofluids

Paris-Sud XI, Université de

127

Sound Waves, Thermal Conduction, and the Continuity Equation Carl Sovinec, T-15 LANL  

E-Print Network [OSTI]

Sound Waves, Thermal Conduction, and the Continuity Equation Carl Sovinec, T-15 LANL 8 to sound waves when we use thermal conduction in our system of equations without continuity. The fluid definitions 0 02 p c , defining c as the adiabatic sound speed, kc 1 , the time for the adiabatic wave

Sovinec, Carl

128

Electrical Conductivity, Near-Infrared Absorption, and Thermal Lens Spectroscopic Studies of Percolation of Microemulsions  

E-Print Network [OSTI]

Electrical Conductivity, Near-Infrared Absorption, and Thermal Lens Spectroscopic Studies studied below and above the percolation thresholds by electrical conductivity, near-infrared absorption. In this work the structure of microemulsions was investigated by using the near-IR absorption and thermal lens

Reid, Scott A.

129

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

E-Print Network [OSTI]

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, as illustrated by current EU waste policy and its five main priorities: prevention, reuse, recycling, recovery

Paris-Sud XI, Université de

130

Thermal conductance of metal-diamond interfaces at high pressure Gregory T. Hohensee  

E-Print Network [OSTI]

are concerned with the exchange of thermal energy across an interface between two materials. This topic-nonmetal interface, a two-temperature model predicts a thermal resistance of Rep = 1/ gL in series with the phononThermal conductance of metal-diamond interfaces at high pressure Gregory T. Hohensee Department

Cahill, David G.

131

Generalized model of thermal boundary conductance between SWNT and surrounding supercritical Lennard-Jones fluid  

E-Print Network [OSTI]

of the promising applications is to use SWNTs as additives to enhance thermal conductivity of composite materials of the composite can be strongly influenced by thermal boundary resistance (TBR) between carbon nanotubes, it is essential to understand TBR. Thermal boundary resistance, with its importance in small scale, has been

Maruyama, Shigeo

132

Discrete thermal element modelling of heat conduction in particle systems: Basic formulations  

E-Print Network [OSTI]

methodology, termed the discrete thermal element method (DTEM), for the effec- tive modelling of heat rights reserved. Keywords: Discrete thermal element method; Circular particle; Thermal contact; Heat conduction; Boundary (integral) equation/element 1. Introduction Heat transfer in particle systems can

Martin, Ralph R.

133

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

SciTech Connect (OSTI)

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.

Secary, J.J.

1989-01-01T23:59:59.000Z

134

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

SciTech Connect (OSTI)

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.

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)

2014-04-28T23:59:59.000Z

135

Note: Local thermal conductivities from boundary driven non-equilibrium molecular dynamics simulations  

SciTech Connect (OSTI)

We report non-equilibrium molecular dynamics simulations of heat transport in models of molecular fluids. We show that the “local” thermal conductivities obtained from non-equilibrium molecular dynamics simulations agree within numerical accuracy with equilibrium Green-Kubo computations. Our results support the local equilibrium hypothesis for transport properties. We show how to use the local dependence of the thermal gradients to quantify the thermal conductivity of molecular fluids for a wide range of thermodynamic states using a single simulation.

Bresme, F., E-mail: f.bresme@imperial.ac.uk [Department of Chemistry, Chemical Physics Section, Imperial College London, London SW7 2AZ (United Kingdom); Department of Chemistry, Norwegian University of Science and Technology, Trondheim (Norway); Armstrong, J., E-mail: j.armstrong@imperial.ac.uk [Department of Chemistry, Chemical Physics Section, Imperial College London, London SW7 2AZ (United Kingdom)

2014-01-07T23:59:59.000Z

136

The Role of Thermal Conduction in Tearing Mode Theory  

E-Print Network [OSTI]

The role of anisotropic thermal diffusivity on tearing mode stability is analysed in general toroidal geometry. A dispersion relation linking the growth rate to the tearing mode stability parameter, Delta, is derived. By using a resistive MHD code, modified to include such thermal transport, to calculate tearing mode growth rates, the dispersion relation is employed to determine Delta in situations with finite plasma pressure that are stabilised by favourable average curvature in a simple resistive MHD model. We also demonstrate that the same code can also be used to calculate the basis-functions [C J Ham, et al, Plasma Phys. Control. Fusion 54 (2012) 105014] needed to construct Delta.

Connor, J W; Hastie, R J; Liu, Y Q

2014-01-01T23:59:59.000Z

137

G-Plus report to Owens Corning-thermal conductivity Measurements of Fiberglass  

SciTech Connect (OSTI)

Fiberglass made by Owens Corning is being used in noise reduction of automobile exhaust system. Specifically, the glass fibers are packed inside the muffler to achieve the desired acoustic effect. A secondary benefit of the fibers is to serve as a thermal insulation. Because of this insulating property, the glass fibers can serve to reduce the temperature of the muffler shell. This in turn reduces the need for heat shields around mufflers and reduces the amount of exterior temperature accelerated corrosion of the muffler shell, especially in the winter ''salt belts'' where large amounts of salt are placed on highways to minimize the safety impact of snow and ice. In addition, for some applications the use of the fiberglass could allow the use of lighter weight carbon based polymer composite materials in place of steel for muffler shells. However, in order to properly design exhaust systems without heat shields or to take advantage of new materials, the thermal conductivity of the fiberglass material at operating temperatures (for some applications above 750 C) must be known. We selected two types of Owens Corning glass fibers, 17 {micro}m and 24 {micro}m in diameter, for this study. There are some room temperature thermal conductivity data for the fiberglass, but high temperature data are not available. Based on the thermal radiation model, thermal conductivity should increase rapidly at high temperature, providing less thermal insulation. In addition, thermal conductivity depends on packing density of the glass fibers. We will study the effect of packing density on thermal conductivity. Another issue is that the glass fiber conducts heat better along the fiber, while the conduction across the fibers is poor, because thermal conduction from one fiber to another has to go through an interface with thermal resistance. In fiberglass, most fibers are not in good contact with the surrounding fibers, thus, most heat transfer is dependent on the thermal radiation effect. Among the many methods of measuring thermal conductivity, only a few can be used for glass fibers. The traditional heat flow meter is used in testing thermal insulations near room temperature. At higher temperatures this method cannot be used due to material and instrument limitations. Our plan is to use a transient plane source (TPS) method to measure thermal conductivity directly. The advantage of the TPS method is that measurements can be taken at over 700 C, and covers the temperature of the automobile exhausts. The following is a report for the G-Plus project conducted at ORNL to apply the TPS method to characterizing the thermal conductivity of two types of fiberglass and also the effect of packing density.

Wang, H

2003-04-15T23:59:59.000Z

138

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

SciTech Connect (OSTI)

{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.

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)

2014-08-28T23:59:59.000Z

139

HeatProbe: A Thermal-based Power Meter for Accounting Disaggregated Electricity Usage  

E-Print Network [OSTI]

HeatProbe: A Thermal-based Power Meter for Accounting Disaggregated Electricity Usage Bo-Jhang Ho1 Technology Innovation, Academia Sinica 128, Sec. 2, Academia Rd., Taipei 115, Taiwan {cwyou, mschen}@citi.sinica.edu.tw ABSTRACT To promote energy-saving behavior, disaggregating elec- tricity usage is critical for increasing

Ouhyoung, Ming

140

Supplementary information : Probing thermal expansion of graphene and modal dispersion at  

E-Print Network [OSTI]

Supplementary information : Probing thermal expansion of graphene and modal dispersion at low-temperature using graphene NEMS resonators Vibhor Singh1 , Shamashis Sengupta1 , Hari S. Solanki1 , Rohan Dhall1 spectroscopy of the suspended graphene devices We performed Raman spectroscopy to confirm the number of layers

Deshmukh, Mandar M.

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they are not comprehensive nor are they the most current set.
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141

Thermal Conductivity Spectroscopy Technique to Measure Phonon Mean Free Paths  

E-Print Network [OSTI]

Size effects in heat conduction, which occur when phonon mean free paths (MFPs) are comparable to characteristic lengths, are being extensively explored in many nanoscale systems for energy applications. Knowledge of MFPs ...

Schmidt, A. J.

142

Thermal conductivity profile determination in proton-irradiated ZrC by spatial and frequency scanning thermal wave methods  

SciTech Connect (OSTI)

Using complementary thermal wave methods, the irradiation damaged region of zirconium carbide (ZrC) is characterized by quantifiably profiling the thermophysical property degradation. The ZrC sample was irradiated by a 2.6 MeV proton beam at 600 °C to a dose of 1.75 displacements per atom. Spatial scanning techniques including scanning thermal microscopy (SThM), lock-in infrared thermography (lock-in IRT), and photothermal radiometry (PTR) were used to directly map the in-depth profile of thermal conductivity on a cross section of the ZrC sample. The advantages and limitations of each system are discussed and compared, finding consistent results from all techniques. SThM provides the best resolution finding a very uniform thermal conductivity envelope in the damaged region measuring ?52 ± 2 ?m deep. Frequency-based scanning PTR provides quantification of the thermal parameters of the sample using the SThM measured profile to provide validation of a heating model. Measured irradiated and virgin thermal conductivities are found to be 11.9 ± 0.5 W m{sup ?1} K{sup ?1} and 26.7 ±1 W m{sup ?1} K{sup ?1}, respectively. A thermal resistance evidenced in the frequency spectra of the PTR results was calculated to be (1.58 ± 0.1) × 10{sup ?6} m{sup 2} K W{sup ?1}. The measured thermal conductivity values compare well with the thermal conductivity extracted from the SThM calibrated signal and the spatially scanned PTR. Combined spatial and frequency scanning techniques are shown to provide a valuable, complementary combination for thermal property characterization of proton-irradiated ZrC. Such methodology could be useful for other studies of ion-irradiated materials.

Jensen, C. [GRESPI, Multiscale Thermophysics Lab., Université de Reims Champagne-Ardenne URCA, Moulin de la Housse BP 1039, Reims 51687 (France) [GRESPI, Multiscale Thermophysics Lab., Université de Reims Champagne-Ardenne URCA, Moulin de la Housse BP 1039, Reims 51687 (France); Department of Mechanical and Aerospace Engineering, Utah State University, Logan, Utah 84322 (United States); Chirtoc, M.; Horny, N.; Antoniow, J. S.; Pron, H. [GRESPI, Multiscale Thermophysics Lab., Université de Reims Champagne-Ardenne URCA, Moulin de la Housse BP 1039, Reims 51687 (France)] [GRESPI, Multiscale Thermophysics Lab., Université de Reims Champagne-Ardenne URCA, Moulin de la Housse BP 1039, Reims 51687 (France); Ban, H. [Department of Mechanical and Aerospace Engineering, Utah State University, Logan, Utah 84322 (United States)] [Department of Mechanical and Aerospace Engineering, Utah State University, Logan, Utah 84322 (United States)

2013-10-07T23:59:59.000Z

143

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

SciTech Connect (OSTI)

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.

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

2011-09-28T23:59:59.000Z

144

THERMAL CONDUCTIVITY OF AQUEOUS NaCl SOLUTIONS  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystallineForeign Object DamageSystemsU.S. TALKS1THE WHITE 9086 THERMAL

145

Serpentine Thermal Coupling Between a Stream and a Conducting Body  

SciTech Connect (OSTI)

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.

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

2012-02-15T23:59:59.000Z

146

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

SciTech Connect (OSTI)

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.

Du, Shiyu [Los Alamos National Laboratory; Andersson, Anders D. [Los Alamos National Laboratory; Germann, Timothy C. [Los Alamos National Laboratory; Stanek, Christopher R. [Los Alamos National Laboratory

2012-05-02T23:59:59.000Z

147

Thermal conductivity of fluids containing suspension of nanometer-sized particles  

E-Print Network [OSTI]

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 ...

Ma, Jack Jeinhao

2006-01-01T23:59:59.000Z

148

Mixed ionic and electronic conducting electrode studies for an alkali metal thermal to electric converter  

E-Print Network [OSTI]

This research focuses on preparation, kinetics, and performance studies of mixed ionic and electronic conducting electrodes (MIEE) applied in an alkali metal thermal to electric converter (AMTEC). Two types of MIEE, metal/sodium titanate and metal...

Guo, Yuyan

2009-05-15T23:59:59.000Z

149

Effective thermal conductivity measurements relevant to deep borehole nuclear waste disposal  

E-Print Network [OSTI]

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 ...

Shaikh, Samina

2007-01-01T23:59:59.000Z

150

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

E-Print Network [OSTI]

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

Lundstrom, L.

2011-01-01T23:59:59.000Z

151

Geometry and temperature dependent thermal conductivity of diamond nanowires: A non-equilibrium molecular dynamics study  

E-Print Network [OSTI]

plasma etching of polycrystalline diamond films [7], microwave plasma assisted chemical vapor deposition. For theoretical calculations of proper- ties of nanosized diamond materials, polycrystalline diamond thin filmsGeometry and temperature dependent thermal conductivity of diamond nanowires: A non

Melnik, Roderick

152

Enhancing thermal conductivity of fluids with graphite nanoparticles and carbon nanotube  

DOE Patents [OSTI]

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.

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

2008-03-25T23:59:59.000Z

153

Thermal and electrical conduction in the compaction direction of exfoliated graphite  

E-Print Network [OSTI]

Thermal and electrical conduction in the compaction direction of exfoliated graphite in the compaction direction of graphite-flake-based exfoliated graphite have been decoupled. The compact Exfoliated graphite is elongated graphite particles obtained by the exfoliation (typically involving rapid

Chung, Deborah D.L.

154

Lattice thermal conductivity of UO{sub 2} using ab-initio and classical molecular dynamics  

SciTech Connect (OSTI)

We applied the non-equilibrium ab-initio molecular dynamics and predict the lattice thermal conductivity of the pristine uranium dioxide for up to 2000?K. We also use the equilibrium classical molecular dynamics and heat-current autocorrelation decay theory to decompose the lattice thermal conductivity into acoustic and optical components. The predicted optical phonon transport is temperature independent and small, while the acoustic component follows the Slack relation and is in good agreement with the limited single-crystal experimental results. Considering the phonon grain-boundary and pore scatterings, the effective lattice thermal conductivity is reduced, and we show it is in general agreement with the sintered-powder experimental results. The charge and photon thermal conductivities are also addressed, and we find small roles for electron, surface polaron, and photon in the defect-free structures and for temperatures below 1500?K.

Kim, Hyoungchul [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); High-Temperature Energy Materials Research Center, Korea Institute of Science and Technology, Seoul 136–791 (Korea, Republic of); Kim, Moo Hwan [Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of); Kaviany, Massoud, E-mail: kaviany@umich.edu [Department of Mechanical Engineering, University of Michigan, Ann Arbor, Michigan 48109 (United States); Division of Advanced Nuclear Engineering, Pohang University of Science and Technology, Pohang 790-784 (Korea, Republic of)

2014-03-28T23:59:59.000Z

155

Basal-plane thermal conductivity of few-layer molybdenum disulfide  

SciTech Connect (OSTI)

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.

Jo, Insun; Ou, Eric; Shi, Li, E-mail: lishi@mail.utexas.edu [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Pettes, Michael Thompson [Department of Mechanical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Department of Mechanical Engineering and the Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States); Wu, Wei [Department of Mechanical Engineering and the Institute of Materials Science, University of Connecticut, Storrs, Connecticut 06269 (United States)

2014-05-19T23:59:59.000Z

156

Thermal Conductivity of Ordered Mesoporous Nanocrystalline Silicon Thin Films Made from Magnesium Reduction of Polymer-  

E-Print Network [OSTI]

Thermal Conductivity of Ordered Mesoporous Nanocrystalline Silicon Thin Films Made from Magnesium-assembly of mesoporous silica followed by magnesium reduction. The periodic ordering of pores in mesoporous silicon

Pilon, Laurent

157

Thermal conductivity of self-assembled nano-structured ZnO bulk ceramics  

SciTech Connect (OSTI)

In this study, we describe the changes in thermal conductivity behavior of ZnO-Al micro- and nano-two-phase self-assembled composites with varying grain sizes. The reduction in thermal conductivity values of micro-composites was limited to {approx}15% for ZnO-4% Al. However, nano-composites exhibited large reduction, by a factor of about three, due to uniform distribution of nano-precipitates (ZnAl2O4) and large grain boundary area. Interestingly, the micro-composites revealed continuous decrease in thermal conductivity with increase in Al substitution while the nano-composites exhibited the lowest magnitudes for 2% Al concentration. Raman spectra indicated that phonon confinement in ZnO-Al nano-composites causes drastic decrease in the value of thermal conductivity.

Zhao, Yu [Bio-Inspired Materials and Devices Laboraory (BMDL); Yan, Yongke [Bio-Inspired Materials and Devices Laboraory (BMDL); Kumar, Ashok [Bio-Inspired Materials and Devices Laboraory (BMDL); Wang, Hsin [ORNL; Porter, Wallace D [ORNL

2012-01-01T23:59:59.000Z

158

Thermal Conductivity Reduction and Thermoelectric Figure of Merit Increase by Embedding Nanoparticles in Crystalline Semiconductors  

E-Print Network [OSTI]

on the thermoelectric figure of merit (ZT) of a material defined as ZT S2 T=k, where S, , k, and T are the Seebeck by nanostructuring thermoelectric materials, and the key reason for increase in ZT was the reduction of thermalThermal Conductivity Reduction and Thermoelectric Figure of Merit Increase by Embedding

159

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

160

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

E-Print Network [OSTI]

and high aspect ratio result in a significant thermal radiation effect. We simulate the experiment using such as automobile exhaust pipes, power plant steam pipes, manufacturing industry cooling pipes, and so forth. Our the radiation effect and extract the thermal conductivity at the single fiber level. Our simulation method

Ruan, Xiulin

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

MAGNET/CRYOCOOLER INTEGRATIONFOR THERMAL STABILITY IN CONDUCTION-COOLED SYSTEMS  

E-Print Network [OSTI]

-cooling with a closed-cycle refrigerator is an excellent option for relatively small superconducting systems. Since to energy consumption, mainly because the thermal loss associated with the storage and the transferMAGNET/CRYOCOOLER INTEGRATIONFOR THERMAL STABILITY IN CONDUCTION-COOLED SYSTEMS H.-M. Chang and K

Chang, Ho-Myung

162

Mesoscopic simulations of phase distribution effects on the effective thermal conductivity of microgranular porous media.  

E-Print Network [OSTI]

of transport in open-cell metal foam. J. Heat Transfer ASMEopen-celled metal foam model for thermal applications. J. Heat Transferheat transfer is a non-negligible factor for thermal transports in high-porosity low-conductivity open-

Wang, Moran; Pan, Ning; Wang, Jinku; Chen, Shiyi

2007-01-01T23:59:59.000Z

163

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

E-Print Network [OSTI]

conductivity and contact resistance in fuel cell materials Manish Khandelwal, M.M. Mench Fuel Cell Dynamics, and the thermal contact resistance between diffusion media and a metal plate as a function of temperature® membrane; Diffusion media; Thermal contact resistance 1. Introduction Detailed knowledge of the internal

Mench, Matthew M.

164

Size-dependent interface phonon transmission and thermal conductivity of nanolaminates  

E-Print Network [OSTI]

resistance between different materials exists since the interface breaks the regular lattice structure and superlattices as the interface distance or periodic thickness reduces. The interface thermal resistance has beenSize-dependent interface phonon transmission and thermal conductivity of nanolaminates L. H. Liang

Li, Baowen

165

Effective thermal conductivity for anisotropic granular porous media using fractal concepts  

SciTech Connect (OSTI)

The use of granular porous media in chemical processes, thermal insulation, heat exchangers, and nuclear reactor fuel rods has led to the development of correlations for thermophysical properties, such as thermal conductivity. These correlations are essential in the prediction of heat and mass transfer involving porous media. Analytical correlations are derived for the effective thermal conductivity of anisotropic, Granular Porous Media (GPM). The correlations proposed, which can be apply in general to any porous media material, are used to determine the effective thermal conductivity of GPM that are formed by semi-cylindrical ice particles. Pictures of the cross-section of GPM provide digital data for measuring local fractal dimensions. Local fractal dimensions are used to determine an equivalent three-dimensional Representative Unit Cell (RUC) for the GPM considered. A simplified analysis of heat conduction at the RUC level provide an analytical expression for the effective heat transfer coefficient. Estimates for the effective thermal conductivity by the use of the models are discussed and compared with various models known in literature. Finally, results for anisotropic thermal conductivities, which are obtained by the use of fractal correlations, are discussed.

Sabau, A.S.; Tao, Y.X.; Liu, G.; Vidhuvalavan, G.

1997-07-01T23:59:59.000Z

166

Effects of neutron irradiation on thermal conductivity of SiC-based composites and monolithic ceramics  

SciTech Connect (OSTI)

A variety of SiC-based composites and monolithic ceramics were characterized by measuring their thermal diffusivity in the unirradiated, thermal annealed, and irradiated conditions over the temperature range 400 to 1,000 C. The irradiation was conducted in the EBR-II to doses of 33 and 43 dpa-SiC (185 EFPD) at a nominal temperature of 1,000 C. The annealed specimens were held at 1,010 C for 165 days to approximately duplicate the thermal exposure of the irradiated specimens. Thermal diffusivity was measured using the laser flash method, and was converted to thermal conductivity using density data and calculated specific heat values. Exposure to the 165 day anneal did not appreciably degrade the conductivity of the monolithic or particulate-reinforced composites, but the conductivity of the fiber-reinforced composites was slightly degraded. The crystalline SiC-based materials tested in this study exhibited thermal conductivity degradation of irradiation, presumably caused by the presence of irradiation-induced defects. Irradiation-induced conductivity degradation was greater at lower temperatures, and was typically more pronounced for materials with higher unirradiated conductivity. Annealing the irradiated specimens for one hour at 150 C above the irradiation temperature produced an increase in thermal conductivity, which is likely the result of interstitial-vacancy pair recombination. Multiple post-irradiation anneals on CVD {beta}-SiC indicated that a portion of the irradiation-induced damage was permanent. A possible explanation for this phenomenon was the formation of stable dislocation loops at the high irradiation temperature and/or high dose that prevented subsequent interstitial/vacancy recombination.

Senor, D.J.; Youngblood, G.E. [Pacific Northwest National Lab., Richland, WA (United States); Moore, C.E. [Auburn Univ., AL (United States); Trimble, D.J. [Westinghouse Hanford Co., Richland, WA (United States); Woods, J.J. [Lockheed Martin, Schenectady, NY (United States)

1996-06-01T23:59:59.000Z

167

Effects of neutron irradiation on thermal conductivity of SiC-based composites and monolithic ceramics  

SciTech Connect (OSTI)

A variety of SiC-based composites and monolithic ceramics were characterized by measuring their thermal diffusivity in the unirradiated, thermal annealed, and irradiated conditions over the temperature range 400 to 1,000 C. The irradiation was conducted in the EBR-II to doses of 33 and 43 dpa-SiC (185 EFPD) at a nominal temperature of 1,000 C. The annealed specimens were held at 1,010 C for 165 days to approximately duplicate the thermal exposure of the irradiated specimens. Thermal diffusivity was measured using the laser flash method, and was converted to thermal conductivity using density data and calculated specific heat values. Exposure to the 165 day anneal did not appreciably degrade the conductivity of the monolithic or particulate-reinforced composites, but the conductivity of the fiber-reinforced composites was slightly degraded. The crystalline SiC-based materials tested in this study exhibited thermal conductivity degradation after irradiation, presumably caused by the presence of irradiation-induced defects. Irradiation-induced conductivity degradation was greater at lower temperatures, and was typically more pronounced for materials with higher unirradiated conductivity. Annealing the irradiated specimens for one hour at 150 C above the irradiation temperature produced an increase in thermal conductivity, which is likely the result of interstitial-vacancy pair recombination. Multiple post-irradiation anneals on CVD {beta}-SiC indicated that a portion of the irradiation-induced damage was permanent. A possible explanation for this phenomenon was the formation of stable dislocation loops at the high irradiation temperature and/or high dose that prevented subsequent interstitial/vacancy recombination.

Senor, D.J.; Youngblood, G.E. [Pacific Northwest National Lab., Richland, WA (United States); Moore, C.E. [Auburn Univ., AL (United States); Trimble, D.J. [Westinghouse Hanford Co., Richland, WA (United States); Woods, J.J. [Lockheed Martin, Schenectady, NY (United States)

1997-05-01T23:59:59.000Z

168

Analysis of the reduced thermal conductivity in InGaAs/GaAs quantum dot lasers from chirp characteristics  

E-Print Network [OSTI]

injection which we term "thermal impact" , the ther- mal conductivity of the active region is estimatedAnalysis of the reduced thermal conductivity in InGaAs/GaAs quantum dot lasers from chirp; published online 21 September 2006 The thermal conductivity of self-organized quantum dot QD active regions

Klotzkin, David

169

PHYSICAL REVIEW B 90, 174107 (2014) High-throughput computational screening of thermal conductivity, Debye temperature, and  

E-Print Network [OSTI]

for the past few decades [6]. Low thermal conductivity materials constitute the basis of a new generation such as the Debye temperature and the thermal conductivity of materials. We demonstrate that the AGL method, which ranking of the thermal conductivity for several different classes of semiconductor materials

Curtarolo, Stefano

170

Thermal Conduction in Suspended Graphene Layers A. A.BALANDIN, S. GHOSH, D. L. NIKA AND E. P. POKATILOV  

E-Print Network [OSTI]

' properties. Materials with very high or very low thermal conductivities attract particular attention due and engineering research communities to the thermal conductivity of materials. This is explained by both in its atomic structure and the knowledge of thermal conductivity can shed light on many other materials

171

Suppression of thermal conductivity in InxGa12xN alloys by nanometer-scale disorder  

E-Print Network [OSTI]

power requires low lattice thermal conductivity while maintaining high mobility of the charge carriers. The binary InN and GaN materials have high ther- mal conductivity materials9­14 (the room-temperature thermalSuppression of thermal conductivity in InxGa12xN alloys by nanometer-scale disorder T. Tong,1,a) D

Wu, Junqiao

172

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

E-Print Network [OSTI]

for constructing a material with ultra low thermal conductivity is still not available. As a simple. INTRODUCTION Thermal conductivity is one of the most fundamental and important properties of materials.1 heat dissipation. In the former case, one needs to have a very low thermal conductivity, while

Li, Baowen

173

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

E-Print Network [OSTI]

a significant interest as solid breeders for the fusion blankets during the last three decades. The solid for the fusion solid breeder blankets. In order to study the heat transfer in the blanket, effective conductivityEFFECTIVE THERMAL CONDUCTIVITY OF LITHIUM CERAMIC PEBBLE BEDS FOR FUSION BLANKETS: A REVIEW A. ABOU

Abdou, Mohamed

174

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

SciTech Connect (OSTI)

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.

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)

2012-05-15T23:59:59.000Z

175

Composite material having high thermal conductivity and process for fabricating same  

DOE Patents [OSTI]

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.

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

1998-07-21T23:59:59.000Z

176

Composite material having high thermal conductivity and process for fabricating same  

DOE Patents [OSTI]

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.

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

1998-01-01T23:59:59.000Z

177

Effective Thermal Conductivity of Lithium Ceramic Pebble Beds for Fusion Blankets: A Review  

SciTech Connect (OSTI)

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 blankets during the last three decades. The thermal performance of the lithium ceramic pebble beds plays a key role for the fusion blankets. In order to study the heat transfer in the blanket, the effective thermal conductivity of the lithium ceramics pebble beds has to be well measured and characterized. The data of effective thermal conductivity of lithium ceramic pebble beds is important for the blanket design. Several studies have been dedicated to investigate the effective conductivity of the lithium ceramics pebble beds. The objective of this work is to review and compare the available data, presented by various studies, of effective conductivity of lithium ceramic pebble beds in order to address the current status of these data.

Abou-Sena, A.; Ying, A.; Abdou, M. [University of California, Los Angeles (United States)

2005-05-15T23:59:59.000Z

178

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

E-Print Network [OSTI]

heat diffusion equation has been conventionally handled by grid-grids and an approximate delta function simulating a point heatgrid size of 64×64. To obtain transient thermal mask an impulse heat

Ziabari, Amirkoushyar

2012-01-01T23:59:59.000Z

179

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

E-Print Network [OSTI]

is based on an equivalent circuit of thermal resistances andof convection resistance to 0.13 K/W. This is equivalent toequivalent convection coefficient. h = 1/(R × A) The convection resistance

Ziabari, Amirkoushyar

2012-01-01T23:59:59.000Z

180

HeatProbe: a Thermal-based Power Meter System for Tracking Per-user Power Consumption  

E-Print Network [OSTI]

HeatProbe: a Thermal-based Power Meter System for Tracking Per-user Power Consumption Nan-Chen Chen Technology Innovation, Academic Sinica2 {b97006, b96118, b95701241}@csie.ntu.edu.tw, cwyou@citi.sinica.edu.tw, hchu@csie.ntu.edu.tw, mschen@citi.sinica.edu.tw Abstract. This paper proposes HeatProbe, a per

Chu, Hao-hua

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

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

E-Print Network [OSTI]

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.

Yunyun Li; Nianbei Li; Baowen Li

2015-01-29T23:59:59.000Z

182

IEEE TRANSACTIONS ON COMPONENTS AND PACKAGING TECHNOLOGIES, VOL. 25, NO. 4, DECEMBER 2002 615 In-Plane Effective Thermal Conductivity of  

E-Print Network [OSTI]

material. Thermal conductivity of second phase material. . . Heat flux. Mesh numbers along. Effective thermal resistance. Thermal diffusivity. Specific surface area. Porosity. Time. Manuscript effect, the effective thermal conductivity of these materials, is relatively small, so that much

Wirtz, Richard A.

183

Role of anisotropic thermal conductivity in the reversed-field pinch dynamics  

SciTech Connect (OSTI)

Two compressible magnetohydrodynamics simulations of the reversed-field pinch are performed, with isotropic and anisotropic thermal conductivity. We describe in detail the numerical method we use to reproduce the effect of a large parallel thermal conductivity, which makes magnetic field lines almost isothermal. We compare the results of the two simulations, showing that the anisotropic thermal conductivity causes the formation of a hot island when closed magnetic surfaces exist, while temperature becomes almost uniform when the magnetic field is chaotic. After a transient single-helicity state that is formed in the initial phase, a stationary state is reached where the RFP configuration exists in a multiple helicity state, even though the Hartmann number is below the threshold found in previous simulations for the formation of multiple helicity states.

Onofri, M.; Malara, F.; Veltri, P. [Dipartimento di Fisica, Universita della Calabria, ponte P. Bucci, Cubo 31C, 87036 Rende (Italy)

2011-05-15T23:59:59.000Z

184

Esimation of field-scale thermal conductivities of unsaturatedrocks from in-situ temperature data  

SciTech Connect (OSTI)

A general approach is presented here which allows estimationof field-scale thermal properties of unsaturated rock using temperaturedata collected from in situ heater tests. The approach developed here isused to determine the thermal conductivities of the unsaturated host rockof the Drift Scale Test (DST) at Yucca Mountain, Nevada. The DST wasdesigned to obtain thermal, hydrological, mechanical, and chemical (THMC)data in the unsaturated fractured rock of Yucca Mountain. Sophisticatednumerical models have been developed to analyze these THMC data. However,though the objective of those models was to analyze "field-scale" (of theorder of tens-of-meters) THMC data, thermal conductivities measured from"laboratory-scale" core samples have been used as input parameters.While, in the absence of a better alternative, using laboratory-scalethermal conductivity values in field-scale models can be justified, suchapplications introduce uncertainties in the outcome of the models. Thetemperature data collected from the DST provides a unique opportunity toresolve some of these uncertainties. These temperature data can be usedto estimate the thermal conductivity of the DST host rock and, given thelarge volume of rock affected by heating at the DST, such an estimatewill be a more reliable effective thermal conductivity value for fieldscale application. In this paper, thus, temperature data from the DST areused to develop an estimate of the field-scale thermal conductivityvalues of the unsaturated host rock of the DST. An analytical solution isdeveloped for the temperature rise in the host rock of the DST; and usinga nonlinear fitting routine, a best-fit estimate of field-scale thermalconductivity for the DST host rock is obtained. Temperature data from theDST show evidence of two distinct thermal regimes: a zone below boiling(wet) and a zone above boiling (dry). Estimates of thermal conductivityfor both the wet and dry zones are obtained in this paper. Sensitivity ofthese estimates to the input heating power of the DST is alsoinvestigated in this paper. These estimated thermal conductivity valuesare compared with core measurements and those estimated fromgeostatistical simulations. Note that the approach presented here isapplicable to other host rock and heater test settings, provided suitablemodifications are made in the analytical solution to account fordifferences in test geometry.

Mukhopadhyay, Sumit; Tsang, Yvonne W.; Birkholzer, Jens T.

2006-06-26T23:59:59.000Z

185

Thermal Conductivity of Thermally-Isolating Polymeric and Composite Structural Support Materials Between 0.3 and 4 K  

E-Print Network [OSTI]

We present measurements of the low-temperature thermal conductivity of a number of polymeric and composite materials from 0.3 to 4 K. The materials measured are Vespel SP-1, Vespel SP-22, unfilled PEEK, 30% carbon fiber-filled PEEK, 30% glass-filled PEEK, carbon fiber Graphlite composite rod, Torlon 4301, G-10/FR-4 fiberglass, pultruded fiberglass composite, Macor ceramic, and graphite rod. These materials have moderate to high elastic moduli making them useful for thermally-isolating structural supports.

M. C. Runyan; W. C. Jones

2008-06-11T23:59:59.000Z

186

Thermal Conductivity of Thermally-Isolating Polymeric and Composite Structural Support Materials Between 0.3 and 4 K  

E-Print Network [OSTI]

We present measurements of the low-temperature thermal conductivity of a number of polymeric and composite materials from 0.3 to 4 K. The materials measured are Vespel SP-1, Vespel SP-22, unfilled PEEK, 30% carbon fiber-filled PEEK, 30% glass-filled PEEK, carbon fiber Graphlite composite rod, Torlon 4301, G-10/FR-4 fiberglass, pultruded fiberglass composite, Macor ceramic, and graphite rod. These materials have moderate to high elastic moduli making them useful for thermally-isolating structural supports.

Runyan, M C

2008-01-01T23:59:59.000Z

187

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

SciTech Connect (OSTI)

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.

Toews, W. H.; Hill, R. W. [GWPI and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)] [GWPI and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1 (Canada)

2014-04-15T23:59:59.000Z

188

Effective thermal conductivity of two-phase functionally graded particulate H. M. Yin, G. H. Paulino,a  

E-Print Network [OSTI]

, a continuous trade-off of fracture toughness and high thermal conductivity of metals is made with ceramic of the ceramic portions of FGMs. The effective thermal properties in the gradation direction are es- sentialEffective thermal conductivity of two-phase functionally graded particulate composites H. M. Yin, G

Paulino, Glaucio H.

189

PHYSICAL REVIEW B 83, 094521 (2011) Thermal conductivity in the mixed state of a superconductor at low magnetic fields  

E-Print Network [OSTI]

15 March 2011) We evaluate accurate low-field/low-temperature asymptotics of the thermal conductivityPHYSICAL REVIEW B 83, 094521 (2011) Thermal conductivity in the mixed state of a superconductor conductivity at low fields. DOI: 10.1103/PhysRevB.83.094521 PACS number(s): 74.25.fc, 74.25.Uv I. INTRODUCTION

Alexei, Koshelev

190

Evaporation of Picolitre Droplets on Surfaces with a Range of Wettabilities and Thermal Conductivities  

E-Print Network [OSTI]

is underestimated. For picolitre droplets however, convective heat transfer due to internal flows is negligible compared to conduc- tion. The relative effect of convection and conduction is seen in the Pe´clet number, Pe = uR/K, where K is the thermal diffusivity...

Talbot, E.L.; Berson, A.; Brown, P.S.; Bain, C.D.

2012-01-01T23:59:59.000Z

191

Measurement of the electronic thermal conductance channels and heat capacity of graphene at low temperature  

E-Print Network [OSTI]

Measurement of the electronic thermal conductance channels and heat capacity of graphene at low, Gwf , test the Wiedemann-Franz (wf) law, and infer the electronic heat capacity, with a minimum value of a Coulomb-interacting electron-hole plasma may result in deviations from the Fermi-liquid values of the Mott

192

Atomistic calculation of the thermal conductance of large scale bulk-nanowire junctions  

SciTech Connect (OSTI)

We have developed a stable and efficient kernel method to compute thermal transport in open systems, based on the scattering-matrix approach. This method is applied to compute the thermal conductance of a junction between bulk silicon and silicon nanowires with diameter up to 10 nm. We have found that beyond a threshold diameter of 7 nm, transmission spectra and contact conductances scale with the cross section of the contact surface, whereas deviations from this general trend are observed in thinner wires. This result allows us to predict the thermal resistance of bulk-nanowire interfaces with larger cross sections than those tractable with atomistic simulations, and indicate the characteristic size beyond which atomistic systems can in principle be treated accurately by mean-field theories. Our calculations also elucidate how dimensionality reduction and shape affect interfacial heat transport.

Duchemin, Ivan; Donadio, Davide [Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz (Germany)

2011-09-15T23:59:59.000Z

193

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

E-Print Network [OSTI]

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...

Kim, Ick Chan

2009-05-15T23:59:59.000Z

194

Thermal conductivity of ultra-thin chemical vapor deposited hexagonal boron nitride films  

SciTech Connect (OSTI)

Thermal conductivity of freestanding 10?nm and 20?nm thick chemical vapor deposited hexagonal boron nitride films was measured using both steady state and transient techniques. The measured value for both thicknesses, about 100?±?10?W m{sup ?1} K{sup ?1}, is lower than the bulk basal plane value (390?W m{sup ?1} K{sup ?1}) due to the imperfections in the specimen microstructure. Impressively, this value is still 100 times higher than conventional dielectrics. Considering scalability and ease of integration, hexagonal boron nitride grown over large area is an excellent candidate for thermal management in two dimensional materials-based nanoelectronics.

Alam, M. T.; Haque, M. A., E-mail: mah37@psu.edu [Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States); Bresnehan, M. S.; Robinson, J. A. [Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA and The Center for Two-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)] [Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania 16802, USA and The Center for Two-Dimensional and Layered Materials, The Pennsylvania State University, University Park, Pennsylvania 16802 (United States)

2014-01-06T23:59:59.000Z

195

Thermal Conductivity of SiC/Si Composites – Porting PNNL EMTA Code for Fusion Analyses  

SciTech Connect (OSTI)

An existing modeling method, the EMTA (Eshelby-Mori-Tanaka approach) modeling approach [1], is applied to the study of SiC/SiC 2D woven composites for fusion reactor applications for the first time, to the best of our knowledge, with excellent results. We compare EMTA model results to existing thermal conductivity data for these materials and suggest that in the future this approach can be beneficial by providing us with tools to further optimize these composite materials for fusion energy applications since the EMTA method and code can address both thermal and mechanical properties with the same framework.

Henager, Charles H.; Nguyen, Ba Nghiep

2013-04-19T23:59:59.000Z

196

Probes  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - SeptemberMicroneedles for4-16 FORPoints of Contact Privacy Points ofPrivateProbes

197

Probing thermal waves on the free surface of various media: Surface Fluctuation Specular Reflection Spectroscopy  

E-Print Network [OSTI]

Thermal motion gives rise to fluctuations in free surfaces; the propagation of the thermally excited waves on such surfaces depends on the mechanical properties of the medium. Their measurement can therefore provide information on those properties. We have developed an optical tool to probe the thermally excited waves on free surfaces: Surface Fluctuation Specular Reflection (SFSR) spectroscopy. It consists in measuring the fluctuations in the position of a laser beam, which is specularly reflected onto the free surface of a medium, and is therefore sensitive to the roughness of that surface. We show how the measured signal is related to the medium properties. We also present measurements performed on Newtonian liquids as well as on a viscoelastic solid; we show that, in all cases, there is a very good agreement between experimental and computed spectra. SFSR thus applies to a broad range of materials. It moreover offers a very good temporal resolution and should provide a useful tool for dynamical measurements on complex fluids.

Astrid Tay; Caroline Thibierge; Danièle Fournier; Christian Frétigny; François Lequeux; Cécile Monteux; Jean-Paul Roger; Laurence Talini

2008-06-16T23:59:59.000Z

198

PHYSICAL REVIEW B 88, 144305 (2013) Two-channel model for nonequilibrium thermal transport in pump-probe experiments  

E-Print Network [OSTI]

150 nm of the Al/Si0.99Ge0.01 interface. The extra thermal resistance in this region is a result. INTRODUCTION The magnitude of a material's thermal conductivity and spe- cific heat is determinedPHYSICAL REVIEW B 88, 144305 (2013) Two-channel model for nonequilibrium thermal transport in pump

Cahill, David G.

199

Uncertainty Analysis on the Design of Thermal Conductivity Measurement by a Guarded Cut-Bar Technique  

SciTech Connect (OSTI)

A technique adapted from the guarded-comparative-longitudinal heat flow method was selected for the measurement of the thermal conductivity of a nuclear fuel compact over a temperature range characteristic of its usage. This technique fulfills the requirement for non-destructive measurement of the composite compact. Although numerous measurement systems have been created based on the guarded comparative method, comprehensive systematic (bias) and measurement (precision) uncertainty associated with this technique have not been fully analyzed. In addition to the geometric effect in the bias error, which has been analyzed previously, this paper studies the working condition which is another potential error source. Using finite element analysis, this study showed the effect of these two types of error sources in the thermal conductivity measurement process and the limitations in the design selection of various parameters by considering their effect on the precision error. The results and conclusions provide valuable reference for designing and operating an experimental measurement system using this technique.

Jeff Phillips; Changhu Xing; Colby Jensen; Heng Ban1

2011-07-01T23:59:59.000Z

200

Development of a Test Technique to Determine the Thermal Conductivity of Large Refractory Ceramic Test Specimens  

SciTech Connect (OSTI)

A method has been developed to utilize the High Intensity Infrared lamp located at Oak Ridge National Laboratory for the measurement of thermal conductivity of bulk refractory materials at elevated temperatures. The applicability of standardized test methods to determine the thermal conductivity of refractory materials at elevated temperatures is limited to small sample sizes (laser flash) or older test methods (hot wire, guarded hot plate), which have their own inherent problems. A new method, based on the principle of the laser flash method, but capable of evaluating test specimens on the order of 200 x 250 x 50 mm has been developed. Tests have been performed to validate the method and preliminary results are presented in this paper.

Hemrick, James Gordon [ORNL; Dinwiddie, Ralph Barton [ORNL; Loveland, Erick R [ORNL; Prigmore, Andre L [ORNL

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Effect of phonon confinement on lattice thermal conductivity of lead Telluride quantum well structure  

SciTech Connect (OSTI)

The paper examines the effect of spatial confinement of acoustic phonons on average group velocity and consequently the lattice thermal conductivity of a free-standing PbTe quantum well structure and their temperature dependence. The average group velocity at 100 Å decreases 30% to the bulk value and falls more rapidly on reducing the width of quantum well. Moreover, the lattice thermal conductivity of 100 Å wide PbTe quantum well with value of 0.60 W/mK shows considerable decrease of 70% compared to it’s bulk value. It is observed that the effect of reduction in well width is less pronounce as temperature increases. This appears mainly due to dominance of umklapp processes over the confinement effects.

Tripathi, Madhvendra Nath, E-mail: ommadhav27@gmail.com [Department of Pure and Applied Physics, Guru Ghasidas Vishwavidyalaya, Bilaspur-495009, Chhattisgarh (India)

2014-04-24T23:59:59.000Z

202

The Impact of Thermal Conductivity and Diffusion Rates on Water Vapor Transport through Gas Diffusion Layers  

E-Print Network [OSTI]

Water management in a hydrogen polymer electrolyte membrane (PEM) fuel cell is critical for performance. The impact of thermal conductivity and water vapor diffusion coefficients in a gas diffusion layer (GDL) has been studied by a mathematical model. The fraction of product water that is removed in the vapour phase through the GDL as a function of GDL properties and operating conditions has been calculated and discussed. Furthermore, the current model enables identification of conditions when condensation occurs in each GDL component and calculation of temperature gradient across the interface between different layers, providing insight into the overall mechanism of water transport in a given cell design. Water transport mode and condensation conditions in the GDL components depend on the combination of water vapor diffusion coefficients and thermal conductivities of the GDL components. Different types of GDL and water removal scenarios have been identified and related to experimentally-determined GDL proper...

Burlatsky, S F; Gummallaa, M; Condita, D; Liua, F

2013-01-01T23:59:59.000Z

203

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

E-Print Network [OSTI]

of the vapor deposition process when using soft metallic coatings so that the maximum allowable enhancement for a specific coating thickness can be obtained. Also, the temperature dependence for the microhardness of copper was ex- perimentally determined...- sate for the difFerence in layer and substrate thermal conductivities. When applied, the model agreed well with the data obtained in this investigation at low coating thick- ness but overpredicted the data, as the thickness increased. In addition...

Ochterbeck, Jay Matthew

1990-01-01T23:59:59.000Z

204

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

SciTech Connect (OSTI)

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.

Tadjarodi, Azadeh, E-mail: tajarodi@iust.ac.ir [Research Laboratory of Inorganic Materials Synthesis, Department of Chemistry, Iran University of Science and Technology, 16846-13114 Tehran (Iran, Islamic Republic of); Zabihi, Fatemeh [Research Laboratory of Inorganic Materials Synthesis, Department of Chemistry, Iran University of Science and Technology, 16846-13114 Tehran (Iran, Islamic Republic of); Chemistry and Nanotechnology Laboratory, National Center for Laser Science and Technology, Tehran (Iran, Islamic Republic of)

2013-10-15T23:59:59.000Z

205

Unglazed transpired solar collector having a low thermal-conductance absorber  

DOE Patents [OSTI]

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.

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

1997-12-02T23:59:59.000Z

206

Unglazed transpired solar collector having a low thermal-conductance absorber  

DOE Patents [OSTI]

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.

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

1997-01-01T23:59:59.000Z

207

Thermal conductance between an SWNT and Lennard-Jones fluid Yasuhiro Igarashi, Junichiro Shiomi and Shigeo Maruyama  

E-Print Network [OSTI]

Thermal conductance between an SWNT and Lennard-Jones fluid Yasuhiro Igarashi, Junichiro Shiomi and Shigeo Maruyama Department of Mechanical Engineering, The University of Tokyo 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan Thermal conductance between an SWNT and Lennard-Jones fluid is studied

Maruyama, Shigeo

208

THE JOURNAL OF CHEMICAL PHYSICS 140, 114502 (2014) Thermal conductivity of simple liquids: Origin of temperature and packing  

E-Print Network [OSTI]

. For example, in concen- trating solar power plants1 or in prospective Generation IV nuclear reactors,2THE JOURNAL OF CHEMICAL PHYSICS 140, 114502 (2014) Thermal conductivity of simple liquids: Origin dependence of T1/4 3/2 in the thermal conductivity of the simple Lennard-Jones (LJ) liquid is explored

Boyer, Edmond

209

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

E-Print Network [OSTI]

of Hydrated Calcium Silicate Board Materials Chi T. Do, Dale P. Bentz1 , and Paul E. Stutzman Building and pore size are examined for two calcium silicate boards of different densities. Thermal conductivities; radiation; thermal conductivity. Introduction In recent years, a variety of low-density calcium silicate

Bentz, Dale P.

210

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

E-Print Network [OSTI]

, and Oxidation Resistance of Y3Al5O12 (YAG)/Y2O3­ZrO2 (YSZ) Thermal-Barrier Coatings Y. J. Su, R. W. Trice,# K oxidation resistance while maintaining low thermal conductivity and good phase stability. Padture) is proposed. The objective of this work is to quantify the effect of YAG on thermal resistance, long

Trice, Rodney W.

211

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

E-Print Network [OSTI]

or polycrystalline materials in terms of thermal transport. © 2005 American Institute of Physics. DOI: 10 strongly depends on interface conditions, is considered as a major thermal resistive mecha- nismPhonon-hopping thermal conduction in quantum dot superlattices Manu Shamsa, Weili Liu

212

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

SciTech Connect (OSTI)

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.

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

2013-06-01T23:59:59.000Z

213

Picosecond infrared spectroscopy as probe for photochemical or thermal reactions in solid matrices  

SciTech Connect (OSTI)

Spectroscopy in the mid-IR on timescales from pico to milliseconds has been developed for the study of laser-material interactions over broad timescales. To reach these timescales the authors have employed two configurations: (1) for the ps to ns timescale a one and a two stage difference frequency mixing setup is employed, (2) for the longer timescale, CW mid-IR laser diodes have been used. In general, they excite the sample with one pulse at 1064/266/355 nm and probe some time later in the mid IR (2900--800 cm{sup {minus}1}). In the case of photochemical reaction, they excite the sample directly in the UV. Alternatively, they initiate thermal reactions by pumping a heater dye at 1.064 {micro}m, which quickly converts the photon energy into heat. The potential of this technique to study reactions in the solid state was demonstrated for a photochemically induced (266 nm) reaction (Wolff rearrangement of a {alpha}-diazo-ketone to {alpha}-keto-ketene) in a polymer matrix. Thermal initiation resulted in a similar reaction. The position, amplitude and width of the product bands changed, they believe due to additional side reactions and temperature effects.

Lippert, T.; Funk, D.J.; Strauss, C.E.M.; Stoutland, P.O.

1998-08-01T23:59:59.000Z

214

Measurement of probe displacement to the thermal resolution limit in photonic force microscopy using a miniature quadrant photodetector  

SciTech Connect (OSTI)

A photonic force microscope comprises of an optically trapped micro-probe and a position detection system to track the motion of the probe. Signal collection for motion detection is often carried out using the backscattered light off the probe-however, this mode has problems of low S/N due to the small backscattering cross sections of the micro-probes typically used. The position sensors often used in these cases are quadrant photodetectors. To ensure maximum sensitivity of such detectors, it would help if the detector size matched with the detection beam radius after the condenser lens (which for backscattered detection would be the trapping objective itself). To suit this condition, we have used a miniature displacement sensor whose dimensions makes it ideal to work with 1:1 images of micrometer-sized trapped probes in the backscattering detection mode. The detector is based on the quadrant photo-integrated chip in the optical pick-up head of a compact disc player. Using this detector, we measured absolute displacements of an optically trapped 1.1 {mu}m probe with a resolution of {approx}10 nm for a bandwidth of 10 Hz at 95% significance without any sample or laser stabilization. We characterized our optical trap for different sized probes by measuring the power spectrum for each probe to 1% accuracy, and found that for 1.1 {mu}m diameter probes, the noise in our position measurement matched the thermal resolution limit for averaging times up to 10 ms. We also achieved a linear response range of around 385 nm with cross talk between axes {approx_equal}4% for 1.1 {mu}m diameter probes. The detector has extremely high bandwidth (few MHz) and low optical power threshold-other factors that can lead to its widespread use in photonic force microscopy.

Pal, Sambit Bikas; Haldar, Arijit; Roy, Basudev; Banerjee, Ayan [Department of Physical Sciences, IISER-Kolkata, West Bengal 741252 (India)

2012-02-15T23:59:59.000Z

215

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

SciTech Connect (OSTI)

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.

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

2014-05-01T23:59:59.000Z

216

Thermal interface conductance across a graphene/hexagonal boron nitride heterojunction  

SciTech Connect (OSTI)

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.

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)

2014-02-24T23:59:59.000Z

217

Fabrication of high thermal conductivity arrays of carbon nanotubes and their composites  

DOE Patents [OSTI]

Methods and apparatus are described for fabrication of high thermal conductivity arrays of carbon nanotubes and their composites. A composition includes a vertically aligned nanotube array including a plurality of nanotubes characterized by a property across substantially all of the vertically aligned nanotube array. A method includes depositing a vertically aligned nanotube array that includes a plurality of nanotubes; and controlling a deposition rate of the vertically aligned nanotubes array as a function of an in situ monitored property of the plurality of nanotubes.

Geohegan, David B. (Knoxville, TN) [Knoxville, TN; Ivanov, Ilya N. (Knoxville, TN) [Knoxville, TN; Puretzky, Alexander A [Knoxville, TN

2010-07-27T23:59:59.000Z

218

Coupled heat conduction and thermal stress formulation using explicit integration. [LMFBR  

SciTech Connect (OSTI)

The formulation needed for the conductance of heat by means of explicit integration is presented. The implementation of these expressions into a transient structural code, which is also based on explicit temporal integration, is described. Comparisons of theoretical results with code predictions are given both for one-dimensional and two-dimensional problems. The coupled thermal and structural solution of a concrete crucible, when subjected to a sudden temperature increase, shows the history of cracking. The extent of cracking is compared with experimental data.

Marchertas, A.H.; Kulak, R.F.

1982-06-01T23:59:59.000Z

219

MODELING THE TRANSVERSE THERMAL CONDUCTIVITY OF 2D-SICF/SIC COMPOSITES  

SciTech Connect (OSTI)

A hierarchical model was developed to describe the effective transverse thermal conductivity, K effective, of a 2D-SiC/SiC composite made from stacked and infiltrated woven fabric layers in terms of constituent properties and microstructural and architectural variables. The model includes the expected effects of fiber-matrix interfacial conductance as well as the effects of high fiber packing fractions within individual tows and the non-uniform nature of 2D-fabric layers that include a significant amount of interlayer porosity. Model predictions were obtained for two versions of DuPont 2D-Hi Nicalon(Trademark)/PyC/ICVI-SiC composite, one with a thin (0.110 micron) and the other with a thick (1.040 micron) PyC fiber coating. The model predicts that the matrix porosity content and porosity shape factor have a major influence on K effective(T) for such a composite.

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

2002-09-01T23:59:59.000Z

220

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

E-Print Network [OSTI]

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

Roshandell, Melina

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

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

E-Print Network [OSTI]

Proceedings on thermal energy storage and energy conversion;polymer microcomposites for thermal energy storage. SAE SocLow temperature thermal energy storage: a state of the art

Roshandell, Melina

2013-01-01T23:59:59.000Z

222

Manipulator having thermally conductive rotary joint for transferring heat from a test specimen  

DOE Patents [OSTI]

A manipulator for rotatably moving a test specimen in an ultra-high vacuum chamber includes a translational unit movable in three mutually perpendicular directions. A manipulator frame is rigidly secured to the translational unit for rotatably supporting a rotary shaft. A first copper disc is rigidly secured to an end of the rotary shaft for rotary movement within the vacuum chamber. A second copper disc is supported upon the first disc. The second disc receives a cryogenic cold head and does not rotate with the first disc. The second disc receives a cryogenic cold head and does not rotate with the first disc. A sapphire plate is interposed between the first and second discs to prevent galling of the copper material while maintaining high thermal conductivity between the first and second discs. A spring is disposed on the shaft to urge the second disc toward the first disc and compressingly engage the interposed sapphire plate. A specimen mount is secured to the first disc for rotation within the vacuum chamber. The specimen maintains high thermal conductivity with the second disc receiving the cryogenic transfer line.

Haney, S.J.; Stulen, R.H.; Toly, N.F.

1983-05-03T23:59:59.000Z

223

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

SciTech Connect (OSTI)

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.

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

2014-02-21T23:59:59.000Z

224

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

E-Print Network [OSTI]

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 ...

Zuo, Yanjia

2010-01-01T23:59:59.000Z

225

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

E-Print Network [OSTI]

??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… (more)

Zuo, Yanjia

2010-01-01T23:59:59.000Z

226

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

E-Print Network [OSTI]

An experimental investigation exploring the use of wire mesh/hollow glass microsphere combination for use as thermal insulation was conducted with the aim to conclude whether or not it represents a superior insulation technology to those...

Mckenna, Sean

2010-01-15T23:59:59.000Z

227

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

E-Print Network [OSTI]

AN EXPERIMENTAL INVESTIGATION OF THERMAL CONTACT CONDUCTANCE ACROSS CARBON FIBER/EPOXY RESIN COMPOSITES AS A FUNCTION OF INTERFACE PRESSURE A Thesis by MICHAEL EVERETT RHOADES Submitted to the Office of Graduate Studies of Texas A...&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...

Rhoades, Michael Everett

1989-01-01T23:59:59.000Z

228

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

E-Print Network [OSTI]

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...

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

2006-01-01T23:59:59.000Z

229

Thermally conductive cementitious grouts for geothermal heat pumps. Progress report FY 1998  

SciTech Connect (OSTI)

Research commenced in FY 97 to determine the suitability of superplasticized cement-sand grouts for backfilling vertical boreholes used with geothermal heat pump (GHP) systems. The overall objectives were to develop, evaluate and demonstrate cementitious grouts that could reduce the required bore length and improve the performance of GHPs. This report summarizes the accomplishments in FY 98. The developed thermally conductive grout consists of cement, water, a particular grade of silica sand, superplasticizer and a small amount of bentonite. While the primary function of the grout is to facilitate heat transfer between the U-loop and surrounding formation, it is also essential that the grout act as an effective borehole sealant. Two types of permeability (hydraulic conductivity) tests was conducted to evaluate the sealing performance of the cement-sand grout. Additional properties of the proposed grout that were investigated include bleeding, shrinkage, bond strength, freeze-thaw durability, compressive, flexural and tensile strengths, elastic modulus, Poisson`s ratio and ultrasonic pulse velocity.

Allan, M.L.; Philippacopoulos, A.J.

1998-11-01T23:59:59.000Z

230

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

SciTech Connect (OSTI)

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.

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

2014-05-12T23:59:59.000Z

231

Thermal conductance of graphene and dimerite Jin-Wu Jiang,1 Jian-Sheng Wang,1 and Baowen Li1,2,*  

E-Print Network [OSTI]

Thermal conductance of graphene and dimerite Jin-Wu Jiang,1 Jian-Sheng Wang,1 and Baowen Li1,2,* 1; published 20 May 2009 We investigate the phonon thermal conductance of graphene regarding the graphene sheet as the large-width limit of graphene strips in the ballistic limit. We find that the thermal conductance

Li, Baowen

232

Measurement of the Anisotropic Thermal Conductivity of Molybdenum Disulfide Single Crystal by the Time-resolved Magneto-optic Kerr Effect  

E-Print Network [OSTI]

with perpendicular magnetization serves as the heater and thermometer in the experiment. The low thermal conductivity for determining the thermal conductivity of materials but the sensitivity of TDTR to the lateral or in-plane thermal conductivity of a sample is low when conventional choices are made for laser spot sizes, #12

Cahill, David G.

233

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

E-Print Network [OSTI]

The objective of this work was to evaluate a new high conductivity nuclear fuel form. Uranium dioxide (UO2) is a very effective nuclear fuel, but it’s performance is limited by its low thermal conductivity. The fuel concept considered here is a...

Naramore, Michael J

2010-08-03T23:59:59.000Z

234

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

SciTech Connect (OSTI)

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.

Shibata, Y., E-mail: shibata.yoshihide@jaea.go.jp; Manabe, T.; Ohno, N.; Takagi, M. [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Kajita, S. [EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8603 (Japan); Tsuchiya, H.; Morisaki, T. [National Institute for Fusion Science, Oroshi, Toki, Gifu 509-5292 (Japan)

2014-09-15T23:59:59.000Z

235

Method of making improved gas storage carbon with enhanced thermal conductivity  

DOE Patents [OSTI]

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).

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

2002-11-05T23:59:59.000Z

236

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

SciTech Connect (OSTI)

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.

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)

2013-03-01T23:59:59.000Z

237

Investigation into the effect of heat treatment on the thermal conductivity of 3-D carbon/carbon fiber composites  

SciTech Connect (OSTI)

The material used in this study was a carbon-carbon fiber composite manufactured from precursor yarn and petroleum based pitch through a process of repetitive densification of a woven preform. The resultant high temperature-high strength material exhibits relatively high thermal conductivity and is thus of interest to the fusion energy, plasma materials interactions (PMI) and plasma facing components (PFC) communities. Carbon-carbon fiber composite manufacture involves two distinct processes, preform weaving and component densification. In this study three samples were subjected to an additional heat treatment of 2550, 2750 or 3000{degree}C at Oak Ridge National Laboratory (ORNL) subsequent to their fourth graphitization at 2400{degree}C. It should be noted that no effort was made to optimize the composite for thermal conductivity, but rather only to provide a material with which to evaluate the effect of the final heat treatment temperature on the thermal conductivity. The fiber is the primary source of heat conduction in the composite. Consequently, increasing the fiber volume fraction, and/or the fiber thermal conductivity is expected to increase the composite thermal conductivity. 3 refs., 1 fig.

Dinwiddie, R.B.; Burchell, T.D. (Oak Ridge National Lab., TN (USA)); Baker, C.F. (Fiber Materials, Inc., Biddeford, ME (USA))

1991-01-01T23:59:59.000Z

238

Microstructure and thermal conductivity of surfactant-free NiO nanostructures  

SciTech Connect (OSTI)

High purity, nanometer sized surfactant-free nickel oxide (NiO) particles were produced in gram scale using a solution combustion method and characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), gas pycnometry and gas adsorption analysis (BET). The average particle size of the as-synthesized NiO increases significantly with the preheating temperature of the furnace, while the specific surface area decreases. A BET specific surface area of {approx}100 m{sup 2}/g was obtained for NiO nanoparticles with size as small as 3 nm synthesized at 300 Degree-Sign C. The thermal conductivity ({kappa}) of pressed pellets of the synthesized NiO nanoparticles obtained using spark plasma sintering (SPS) and uniaxial hot pressing is drastically decreased ({approx}60%) compared to that of NiO single crystal. This strong reduction in {kappa} with particle size suggests the suitability of the synthesized surfactant-free NiO nanoparticles for use as nanoinclusions when designing high performance materials for waste heat recovery. - Graphical abstract: Highly efficient phonon scattering by surfactant-free NiO nanostructures obtained by solution combustion of a mixture of nickel (II) nitrate hexahydrate (oxidizer) and urea (fuel) at various temperatures. Highlights: Black-Right-Pointing-Pointer Fast synthesis of surfactant-free NiO nanoparticles with controllable size. Black-Right-Pointing-Pointer High specific surface area for NiO nanoparticles with size range from 3 to 7 nm. Black-Right-Pointing-Pointer Strong reduction of the thermal conductivity with decreasing particle size. Black-Right-Pointing-Pointer NiO as nanoinclusions in high performance materials for energy conversion.

Sahoo, Pranati [Laboratory for Emerging Energy and Electronic Materials, Materials Science and Engineering Department, University of Michigan, Ann Arbor, MI 48109 (United States); Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States); Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Misra, Dinesh K. [The Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Salvador, Jim [Chemical Sciences and Materials Systems Laboratory, General Motors R and D Center, Warren, MI 48090 (United States); Makongo, Julien P.A. [Laboratory for Emerging Energy and Electronic Materials, Materials Science and Engineering Department, University of Michigan, Ann Arbor, MI 48109 (United States); Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Chaubey, Girija S. [Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Takas, Nathan J. [Laboratory for Emerging Energy and Electronic Materials, Materials Science and Engineering Department, University of Michigan, Ann Arbor, MI 48109 (United States); Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Wiley, John B. [Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States); Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States); Poudeu, Pierre F.P., E-mail: ppoudeup@umich.edu [Laboratory for Emerging Energy and Electronic Materials, Materials Science and Engineering Department, University of Michigan, Ann Arbor, MI 48109 (United States); Department of Chemistry, University of New Orleans, New Orleans, LA 70148 (United States); Advanced Materials Research Institute, University of New Orleans, New Orleans, LA 70148 (United States)

2012-06-15T23:59:59.000Z

239

Thermal conduction by dark matter with velocity and momentum-dependent cross-sections  

E-Print Network [OSTI]

We use the formalism of Gould and Raffelt to compute the dimensionless thermal conduction coefficients for scattering of dark matter particles with standard model nucleons via cross-sections that depend on the relative velocity or momentum exchanged between particles. Motivated by models invoked to reconcile various recent results in direct detection, we explicitly compute the conduction coefficients $\\alpha$ and $\\kappa$ for cross-sections that go as $v_{\\rm rel}^2$, $v_{\\rm rel}^4$, $v_{\\rm rel}^{-2}$, $q^2$, $q^4$ and $q^{-2}$, where $v_{\\rm rel}$ is the relative DM-nucleus velocity and $q$ is the momentum transferred in the collision. We find that a $v_{\\rm rel}^{-2}$ dependence can significantly enhance energy transport from the inner solar core to the outer core. The same can true for any $q$-dependent coupling, if the dark matter mass lies within some specific range for each coupling. This effect can complement direct searches for dark matter; combining these results with state-of-the-art Solar simulations should greatly increase sensitivity to certain DM models. It also seems possible that the so-called Solar Abundance Problem could be resolved by enhanced energy transport in the solar core due to such velocity- or momentum-dependent scatterings.

Aaron C. Vincent; Pat Scott

2014-04-23T23:59:59.000Z

240

MODELING THE TRANSVERSE THERMAL CONDUCTIVITY OF 3D-SICF/SIC COMPOSITES  

SciTech Connect (OSTI)

Our previously developed hierarchical two-layer (H2L) model was modified to describe the effective transverse thermal conductivity (Keff) of a three-dimensional (3D) SiC/SiC composite plate made with cross-layered and Z-stitched X:Y:Z uniaxial fiber tow sub-units. As before, the model describes Keff in terms of constituent, microstructural and architectural properties that include the expected effects of fiber-matrix interfacial conductance, of high fiber packing fractions within individual tow sub-units and of the non-uniform porosity contents, shapes and orientations within these sub-units. Model predictions were obtained for two versions of a 3D-Tyranno SA?/PyC/ICVI-SiC composite that had similar fiber/matrix pyrocarbon (PyC) interfaces, relatively high bulk densities (~2.88 g/cc), and an X:Y configuration with fiber content ratios 1:1. The only major difference between the two versions was their Z-stitch fiber content where the relative fiber ratios were 0.1 and 1.2 in the Z sub-units.

Youngblood, Gerald E.; Jones, Russell H.; Yamada, Reiji

2004-06-30T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

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

SciTech Connect (OSTI)

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.

Gorham, Caroline S.; Gaskins, John T.; Hopkins, Patrick E., E-mail: phopkins@virginia.edu [Department of Mechanical and Aerospace Engineering, University of Virginia, Charlottesville, Virginia 22904 (United States); Parsons, Gregory N.; Losego, Mark D. [Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

2014-06-23T23:59:59.000Z

242

Comparison of Different Upscaling Methods for Predicting Thermal Conductivity of Complex Heterogeneous Materials System: Application on Nuclear Waste Forms  

SciTech Connect (OSTI)

To develop a strategy in thermal conductivity prediction of a complex heterogeneous materials system, loaded nuclear waste forms, the computational efficiency and accuracy of different upscaling methods have been evaluated. 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. Several methods, including the Taylor model, Sachs model, self-consistent model, and statistical upscaling method, were developed and implemented. Microstructure based finite element method (FEM) prediction results were used to as benchmark to determine the accuracy of the different upscaling methods. Micrographs from waste forms with varying waste loadings were used in the prediction of thermal conductivity in FEM and homogenization methods. Prediction results demonstrated that in term of efficiency, boundary models (e.g., Taylor model and Sachs model) are stronger than the self-consistent model, statistical upscaling method, and finite element method. However, when balancing computational efficiency and accuracy, statistical upscaling is a useful method in predicting effective thermal conductivity for nuclear waste forms.

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

2012-06-16T23:59:59.000Z

243

Thermal conductivity of Zn{sub 4{minus}x}Cd{sub x}Sb{sub 3} solid solutions  

SciTech Connect (OSTI)

{beta}-Zn{sub 4}Sb{sub 3} was recently identified at the Jet Propulsion Laboratory as a new high performance p-type thermoelectric material with a maximum dimensionless thermoelectric figure of merit ZT of 1.4 at a temperature of 673K. A usual approach, used for many state-of-the-art thermoelectric materials, to further improve ZT values is to alloy {beta}-Zn{sub 4}Sb{sub 3} with isostructural compounds because of the expected decrease in lattice thermal conductivity. The authors have grown Zn{sub 4{minus}x}Cd{sub x}Sb{sub 3} crystals with 0.2 {le} x < 1.2 and measured their thermal conductivity from 10 to 500K. The thermal conductivity values of Zn{sub 4{minus}x}Cd{sub x}Sb{sub 3} alloys are significantly lower than those measured for {beta}-Zn{sub 4}Sb{sub 3} and are comparable to its calculated minimum thermal conductivity. A strong atomic disorder is believed to be primarily at the origin of the very low thermal conductivity of these materials which are also fairly good electrical conductors and are therefore excellent candidates for thermoelectric applications.

Caillat, T.; Borshchevsky, A.; Fleurial, J.P.

1997-07-01T23:59:59.000Z

244

Effects of temperature and disorder on thermal boundary conductance at solidsolid interfaces: Nonequilibrium  

E-Print Network [OSTI]

with the constituent materials. The inter- face thermal resistance, often referred to as thermal boundary resistance between two different materials when a heat flux is applied. The inverse of thermal boundary resistance mismatched interfaces. Ã? 2007 Elsevier Ltd. All rights reserved. Keywords: Thermal boundary resistance

Zhigilei, Leonid V.

245

Ultra-Low Thermal Conductivity in W/Al2O3 Nanolaminates  

E-Print Network [OSTI]

conversion (3). Conversely, the thermal resistance of interfaces degrades the performance of materials dissimilar materials may provide a route for the production of thermal barriers with ultra-low thermal and improve the performance of thermal bar- riers (2) and of materials used in thermoelec- tric energy

George, Steven M.

246

Numerical investigation of CO{sub 2} emission and thermal stability of a convective and radiative stockpile of reactive material in a cylindrical pipe of variable thermal conductivity  

SciTech Connect (OSTI)

In this paper the CO{sub 2} emission and thermal stability in a long cylindrical pipe of combustible reactive material with variable thermal conductivity are investigated. It is assumed that the cylindrical pipe loses heat by both convection and radiation at the surface. The nonlinear differential equations governing the problem are tackled numerically using Runge-Kutta-Fehlberg method coupled with shooting technique method. The effects of various thermophysical parameters on the temperature and carbon dioxide fields, together with critical conditions for thermal ignition are illustrated and discussed quantitatively.

Lebelo, Ramoshweu Solomon, E-mail: sollyl@vut.ac.za [Department of Mathematics, Vaal University of Technology, Private Bag X021, Vanderbijlpark, 1911 (South Africa)

2014-10-24T23:59:59.000Z

247

Conduction Effect of Thermal Radiation in a Metal Shield Pipe in a Cryostat for a Cryogenic Interferometric Gravitational Wave Detector  

E-Print Network [OSTI]

A large heat load caused by thermal radiation through a metal shield pipe was observed in a cooling test of a cryostat for a prototype of a cryogenic interferometric gravitational wave detector. The heat load was approximately 1000 times larger than the value calculated by the Stefan-Boltzmann law. We studied this phenomenon by simulation and experiment and found that it was caused by the conduction of thermal radiation in a metal shield pipe.

Takayuki Tomaru; Masao Tokunari; Kazuaki Kuroda; Takashi Uchiyama; Akira Okutomi; Masatake Ohashi; Hiroyuki Kirihara; Nobuhiro Kimura; Yoshio Saito; Nobuaki Sato; Takakazu Shintomi; Toshikazu Suzuki; Tomiyoshi Haruyama; Shinji Miyoki; Kazuhiro Yamamoto; Akira Yamamoto

2007-11-06T23:59:59.000Z

248

Thermal conductivity of the electrode gap of a thermionic converter, filled with inert gases, at low pressures  

SciTech Connect (OSTI)

Experimental data is presented on the thermal conductivity of the electrode gap of a thermionic converter filled with He, Ar, and Xe in the pressure range 40--550 Pa. The need to account for the coefficients of thermal accommodation of the emitter-inert-gas-collector system in this range is shown. The accommodation coefficients for different temperature regimes are measured and expressions are obtained to calculate the heat flux transported by the inert gases in the electrode gap.

Modin, V.A.; Nikolaev, Y.V.

1985-11-01T23:59:59.000Z

249

Effective Thermal Conductivity of a Li{sub 2}TiO{sub 3} Pebble Bed for a DEMO Blanket  

SciTech Connect (OSTI)

In development of the ceramic breeder blanket, the effective thermal conductivity of pebble beds is an important design parameter. For thermo-mechanical design of blanket, pebble beds were investigated used for Li{sub 2}TiO{sub 3} that was a candidate for tritium breeder. Li{sub 2}TiO{sub 3} pebble beds, whose size was 0.28-1.91 mm diameter, were measured on load under no neutron irradiation. The effective thermal conductivity was increased with load increasing was obtained.

Hatano, T.; Enoeda, M.; Suzuki, S.; Kosaku, Y.; Akiba, M. [Japan Atomic Energy Research Institute (Japan)

2003-07-15T23:59:59.000Z

250

Design and thermal modeling of a non-invasive probe for measuring perfusion by thermodiffusion  

E-Print Network [OSTI]

This research 1) explores the feasibility of developing a non-invasive probe to precisely quantify microcirculatory blood flow (tissue perfusion), in real time and in absolute units, and 2) presents designs and models of ...

Charles, Steven Knight

2004-01-01T23:59:59.000Z

251

Photothermal measurement of the thermal conductivity of supercooled water O. Benchikh, D. Fournier, A. C. Boccara  

E-Print Network [OSTI]

Thermal diffusivity measurements of supercooled water have been performed between + 40 °C and - 23 °C properties of supercooled water have been measured [1 ]. However, the thermal conduc- Article published

Boyer, Edmond

252

Measurement of the thermal conductance of the graphene/SiO2 interface Kin Fai Mak, Chun Hung Lui, and Tony F. Heinz  

E-Print Network [OSTI]

, 043112 (2012) Opposite ReD-dependencies of nanofluid (Al2O3) thermal conductivities between heating and cooling modes Appl. Phys. Lett. 101, 083111 (2012) Thermal transport in graphene supported on copper J of thermal transport in this material system2­4 is currently less advanced. The thermal transport properties

Heinz, Tony F.

253

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

SciTech Connect (OSTI)

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.

Hurd, Joseph A.; Van Sciver, Steven W. [National High Magnetic Field Laboratory Tallahassee, FL 32310 USA and FAMU-FSU College of Engineering, Department of M.E., Tallahassee, FL 32310 (United States)

2014-01-29T23:59:59.000Z

254

Microstructural characterization and microstructural effects on the thermal conductivity of AlN(Y2O3) ceramics  

E-Print Network [OSTI]

Microstructural characterization and microstructural effects on the thermal conductivity of AlN(Y2O3) ceramics Ying-Da Yu a , Aase Marie Hundere b , Ragnvald Høier a , Rafal E. Dunin-Borkowski c aluminum nitride (AlN) ceramic materials with Y2O3 as a sintering additive have been sintered at 1880 C

Dunin-Borkowski, Rafal E.

255

Effective Thermal Conductivity of Soda-Lime Silicate Glassmelts with Different Iron Contents Between 1100C and 1500C  

E-Print Network [OSTI]

Effective Thermal Conductivity of Soda-Lime Silicate Glassmelts with Different Iron Contents collected for soda- lime silicate glasses with iron content ranging from 0.008 to 1.1 wt% and temperatures, refractory walls wear more rapidly for clear glassmelts compared with colored ones.1 Soda-lime silicate glass

Pilon, Laurent

256

Hyper-resistivity and electron thermal conductivity due to destroyed magnetic surfaces in axisymmetric plasma equilibria  

SciTech Connect (OSTI)

In order to model the effects of small-scale current-driven magnetic fluctuations in a mean-field theoretical description of a large-scale plasma magnetic field B(x,t), a space and time dependent hyper-resistivity {Lambda}(x,t) can be incorporated into the Ohm's law for the parallel electric field E Dot-Operator B. Using Boozer coordinates, a theoretical method is presented that allows for a determination of the hyper-resistivity {Lambda}({psi}) functional dependence on the toroidal magnetic flux {psi} for arbitrary experimental steady-state Grad-Shafranov axisymmetric plasma equilibria, if values are given for the parallel plasma resistivity {eta}({psi}) and the local distribution of any auxiliary plasma current. Heat transport in regions of plasma magnetic surfaces destroyed by resistive tearing modes can then be modeled by an electron thermal conductivity k{sub e}({psi})=({epsilon}{sub 0}{sup 2}m{sub e}/e{sup 2}){Lambda}({psi}), where e and m{sub e} are the electron charge and mass, respectively, while {epsilon}{sub 0} is the permittivity of free space. An important result obtained for axisymmetric plasma equilibria is that the {psi}{psi}-component of the metric tensor of Boozer coordinates is given by the relation g{sup {psi}{psi}}({psi}){identical_to}{nabla}{psi} Dot-Operator {nabla}{psi}=[{mu}{sub 0}G({psi})][{mu}{sub 0}I({psi})]/{iota}({psi}), with {mu}{sub 0} the permeability of free space, G({psi}) the poloidal current outside a magnetic surface, I({psi}) the toroidal current inside a magnetic surface, and {iota}({psi}) the rotational transform.

Weening, R. H. [Department of Radiologic Sciences, Thomas Jefferson University, 901 Walnut Street, Philadelphia, Pennsylvania 19107-5233 (United States)

2012-06-15T23:59:59.000Z

257

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

E-Print Network [OSTI]

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 $\\mu=0$.

Seung-il Nam

2015-03-04T23:59:59.000Z

258

Probing the mechanism of rubredoxin thermal unfolding in the absence of salt bridges by temperature jump experiments  

SciTech Connect (OSTI)

Rubredoxins are the simplest type of iron-sulphur proteins and in recent years they have been used as model systems in protein folding and stability studies, especially the proteins from thermophilic sources. Here, we report our studies on the rubredoxin from the hyperthermophile Methanococcus jannaschii (T {sub opt} = 85 deg C), which was investigated in respect to its thermal unfolding kinetics by temperature jump experiments. Different spectroscopic probes were used to monitor distinct structural protein features during the thermal transition: the integrity of the iron-sulphur centre was monitored by visible absorption spectroscopy, whereas tertiary structure was followed by intrinsic tryptophan fluorescence and exposure of protein hydrophobic patches was sensed by 1-anilinonaphthalene-8-sulphonate fluorescence. The studies were performed at acidic pH conditions in which any stabilising contributions from salt bridges are annulled due to protonation of protein side chain groups. In these conditions, M. jannaschii rubredoxin assumes a native-like, albeit more flexible and open conformation, as indicated by a red shift in the tryptophan emission maximum and 1-anilinonaphthalene-8-sulphonate binding. Temperature jumps were monitored by the three distinct techniques and showed that the protein undergoes thermal denaturation via a simple two step mechanism, as loss of tertiary structure, hydrophobic collapse, and disintegration of the iron-sulphur centre are concomitant processes. The proposed mechanism is framed with the multiphasic one proposed for Pyrococcus furiosus rubredoxin, showing that a common thermal unfolding mechanism is not observed between these two closely related thermophilic rubredoxins.

Henriques, Barbara J. [Instituto Tecnologia Quimica e Biologica, Universidade Nova de Lisboa, Oeiras (Portugal); Saraiva, Ligia M. [Instituto Tecnologia Quimica e Biologica, Universidade Nova de Lisboa, Oeiras (Portugal); Gomes, Claudio M. [Instituto Tecnologia Quimica e Biologica, Universidade Nova de Lisboa, Oeiras (Portugal)]. E-mail: gomes@itqb.unl.pt

2005-08-05T23:59:59.000Z

259

Effect of metallic coatings on the thermal contact conductance of turned surfaces  

E-Print Network [OSTI]

area. . IInfortunately this is not always possible, due to design or load restrictions In situations where the applied load is limited. the thermal contact resistance can be reduced by introducing a material at the interface that is relatively sof... materials on thermal contact resistance both analytically and experimen- tally for a. fixed geometry and material. In the analytical portion, the approximate relative reduction of the thermal contact resistance due to plating was described as ~plating (u...

Kang, Tik Kwie

2012-06-07T23:59:59.000Z

260

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

DOE Patents [OSTI]

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.

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

2010-03-02T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

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

E-Print Network [OSTI]

Thermal energy storage for sustainable energy consumption –Sustainable Energy, Cambridge University Press, 65- Dermott A.M, Frysinger G.R, Storage

Roshandell, Melina

2013-01-01T23:59:59.000Z

262

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

E-Print Network [OSTI]

analyzed a built-in, storage-type water heater containing astorage and thermal protection that can operate with PCM technology. Among them are building insulators, water heaters,

Roshandell, Melina

2013-01-01T23:59:59.000Z

263

Thermal-based probe for testing endothelial dysfunction and possible implications for diagnosing atherosclerosis  

E-Print Network [OSTI]

Endothelial dysfunction is a precursor to atherosclerosis. Thus, the vascular health of an individual can be assessed if endothelial dysfunction can be readily and unambiguously quantified. A thermal-based approach using ...

Lediju, Muyinatu A. (Muyinatu Adebisi)

2006-01-01T23:59:59.000Z

264

Thermal conductivity of the electrode gap of a therminonic converter, filled with inert gases, at low pressures  

SciTech Connect (OSTI)

This paper presents experimental data on the thermal conductivity of the electrode gap of a thermionic converter filled with He, Ar, and Xe in the pessure range 40-550 Pa. The need to account for the coefficients of thermal accomodation of the emitter-inert-gas-collector system in this range is shown. The accomodation coefficients for different temperature regimes are measured and expressions are obtained to calculate the heat flux transported by the inert gases in the electrode gap. A diagram of the experimental thermionic converter is shown.

Modin, V.A.; Nikolaev, Y.V.

1986-05-01T23:59:59.000Z

265

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

SciTech Connect (OSTI)

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.

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

2014-11-01T23:59:59.000Z

266

Critical evaluation of anomalous thermal conductivity and convective heat transfer enhancement in nanofluids  

E-Print Network [OSTI]

While robust progress has been made towards the practical use of nanofluids, uncertainties remain concerning the fundamental effects of nanoparticles on key thermo-physical properties. Nanofluids have higher thermal ...

Prabhat, Naveen

2010-01-01T23:59:59.000Z

267

Estimation of composite thermal conductivity of a heterogeneous methane hydrate sample using iTOUGH2  

E-Print Network [OSTI]

International Conference on Gas Hydrates, Trondheim, Norway,Challenges for the future/gas hydrates, NYAS 912, 304, 2000.C. , Thermal state of the gas hydrate reservoir, natural gas

Gupta, Arvind; Kneafsey, Timothy J.; Moridis, George J.; Seol, Yongkoo; Kowalsky, Michael B.; Sloan Jr., E.D.

2006-01-01T23:59:59.000Z

268

Colloidal metal particles as probes of nanoscale thermal transport in fluids Orla M. Wilson, Xiaoyuan Hu, David G. Cahill,* and Paul V. Braun  

E-Print Network [OSTI]

the heat capacity of the particle to the heat capacity of a layer of the surrounding fluid is given by the ratio of the heat capacity of the particle to the total thermal conductance of the particle quantitative studies of G for solid-liquid interfaces but re- ported values11,12 for the thermal conductance

Braun, Paul

269

Interplay of point defects, biaxial strain, and thermal conductivity in homoepitaxial SrTiO{sub 3} thin films  

SciTech Connect (OSTI)

Separating out effects of point defects and lattice strain on thermal conductivity is essential for improvement of thermoelectric properties of SrTiO{sub 3}. We study relations between defects generated during deposition, induced lattice strain, and their impact on thermal conductivity {kappa} in homoepitaxial SrTiO{sub 3} films prepared by ion-beam sputtering. Lowering the deposition temperature gives rise to lattice expansion by enhancement of point defect density which increases the hardness of the films. Due to a fully coherent substrate-film interface, the lattice misfit induces a large biaxial strain. However, we can show that the temperature dependence of {kappa} is mainly sensitive on the defect concentration.

Wiedigen, S.; Kramer, T.; Knorr, I.; Nee, N.; Hoffmann, J.; Volkert, C. A.; Jooss, Ch. [University of Goettingen, Institute of Materials Physics, Friedrich-Hund-Platz 1, 37077 Goettingen (Germany); Feuchter, M.; Kamlah, M. [Karlsruhe Institute of Technology, Institute for Applied Materials, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

2012-02-06T23:59:59.000Z

270

An optimal guarding scheme for thermal conductivity measurement using a guarded cut-bar technique, part 1 experimental study  

SciTech Connect (OSTI)

In the guarded cut-bar technique, a guard surrounding the measured sample and reference (meter) bars is temperature controlled to carefully regulate heat losses from the sample and reference bars. Guarding is typically carried out by matching the temperature profiles between the guard and the test stack of sample and meter bars. Problems arise in matching the profiles, especially when the thermal conductivitiesof the meter bars and of the sample differ, as is usually the case. In a previous numerical study, the applied guarding condition (guard temperature profile) was found to be an important factor in measurement accuracy. Different from the linear-matched or isothermal schemes recommended in literature, the optimal guarding condition is dependent on the system geometry and thermal conductivity ratio of sample to meter bar. To validate the numerical results, an experimental study was performed to investigate the resulting error under different guarding conditions using stainless steel 304 as both the sample and meter bars. The optimal guarding condition was further verified on a certified reference material, pyroceram 9606, and 99.95% pure iron whose thermal conductivities are much smaller and much larger, respectively, than that of the stainless steel meter bars. Additionally, measurements are performed using three different inert gases to show the effect of the insulation effective thermal conductivity on measurement error, revealing low conductivity, argon gas, gives the lowest error sensitivity when deviating from the optimal condition. The result of this study provides a general guideline for the specific measurement method and for methods requiring optimal guarding or insulation.

Changhu Xing [Utah State Univ., Logan, UT (United States). Dept. of Mechanical and Aerospace Engineering; Colby Jensen [Utah State Univ., Logan, UT (United States). Dept. of Mechanical and Aerospace Engineering; Charles Folsom [Utah State Univ., Logan, UT (United States). Dept. of Mechanical and Aerospace Engineering; Heng Ban [Utah State Univ., Logan, UT (United States). Dept. of Mechanical and Aerospace Engineering; Douglas W. Marshall [Idaho National Laboratory (INL), Idaho Falls, ID (United States)

2014-01-01T23:59:59.000Z

271

A Correction Scheme for Thermal Conductivity Measurement Using the Comparative Cut-bar Technique Based on a 3D Numerical Simulation  

SciTech Connect (OSTI)

As an important factor affecting the accuracy of the thermal conductivity measurement, systematic (bias) error in the guarded comparative axial heat flow (cut-bar) method was mostly neglected by previous researches. This bias is due primarily to the thermal conductivity mismatch between sample and meter bars (reference), which is common for a sample of unknown thermal conductivity. A correction scheme, based on a finite element simulation of the measurement system, was proposed to reduce the magnitude of the overall measurement uncertainty. This scheme was experimentally validated by applying corrections on four types of sample measurements in which the specimen thermal conductivity is much smaller, slightly smaller, equal and much larger than that of the meter bar. As an alternative to the optimum guarding technique proposed before, the correction scheme can be used to minimize uncertainty contribution from the measurement system with non-optimal guarding conditions. It is especially necessary for large thermal conductivity mismatches between sample and meter bars.

Douglas W. Marshall; Changhu Xing; Charles Folsom; Colby Jensen; Heng Ban

2014-05-01T23:59:59.000Z

272

Elliptic flow of thermal dileptons as a probe of QCD matter  

E-Print Network [OSTI]

We study the variation of elliptic flow of thermal dileptons with transverse momentum and invariant mass of the pairs for Pb+Pb collisions at $\\sqrt{s_{NN}}$ = 2.76 TeV. The dilepton productions from quark gluon plasma (QGP) and hot hadrons have been considered including the spectral change of light vector mesons in the thermal bath. The space time evolution has been carried out within the frame work of 2+1 dimensional ideal hydrodynamics with lattice+hadron resonance gas equation of state. We find that a judicious selection of invariant mass(M) and transverse momentum (p_T) windows can be used to extract the collective properties of quark matter, hadronic matter and also get a distinct signature of medium effects on vector mesons. Our results indicate a reduction of elliptic flow (v_2) for M beyond phi mass, which if observed experimentally would give the measure of v_2 of the partonic phase.

Payal Mohanty; Victor Roy; Sabyasachi Ghosh; Santosh K. Das; Bedangadas Mohanty; Sourav Sarkar; Jane Alam; Asis K. Chaudhuri

2012-03-13T23:59:59.000Z

273

Probing the thermal character of analogue Hawking radiation for shallow water waves?  

E-Print Network [OSTI]

We study and numerically compute the scattering coefficients of shallow water waves blocked by a stationary counterflow. When the flow is transcritical, the coefficients closely follow Hawking's prediction according to which black holes should emit a thermal spectrum. We study how the spectrum deviates from thermality when reducing the maximal flow velocity, with a particular attention to subcritical flows since these have been recently used to test Hawking's prediction. For such flows, we show that the emission spectrum is strongly suppressed, and that its Planckian character is completely lost. For low frequencies, we also show that the scattering coefficients are dominated by elastic hydrodynamical channels. Our numerical results reproduce rather well the observations made by S. Weinfurtner {\\it et al.} in the Vancouver experiment. Nevertheless, we propose a new interpretation of what has been observed, as well as new experimental tests.

Florent Michel; Renaud Parentani

2014-09-15T23:59:59.000Z

274

EXPANDED IRON UTA SPECTRA-PROBING THE THERMAL STABILITY LIMITS IN AGN CLOUDS  

SciTech Connect (OSTI)

The Fe unresolved transition arrays (UTAs) produce prominent features in the {approx}15-17 A wavelength range in the spectra of active galactic nuclei (AGNs). Here, we present new calculations of the energies and oscillator strengths of inner-shell lines from Fe XIV, Fe XV, and Fe XVI. These are crucial ions since they are dominant at inflection points in the gas thermal stability curve, and UTA excitation followed by autoionization is an important ionization mechanism for these species. We incorporate these, and data reported in previous papers, into the plasma simulation code Cloudy. This updated physics is subsequently employed to reconsider the thermally stable phases in absorbing media in AGNs. We show how the absorption profile of the Fe XIV UTA depends on density, due to the changing populations of levels within the ground configuration.

Ferland, G. J.; Lykins, M. L. [Department of Physics and Astronomy, University of Kentucky, Lexington, KY 40506 (United States); Kisielius, R.; Jonauskas, V. [Institute of Theoretical Physics and Astronomy, Vilnius University, A. Gostauto 12, LT-01108 (Lithuania); Keenan, F. P. [Astrophysics Research Centre, School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom); Van Hoof, P. A. M. [Royal Observatory of Belgium, Ringlaan 3, B-1180 Brussel (Belgium); Porter, R. L. [Department of Physics, University of Georgia, Athens, GA 30602 (United States); Williams, R. J. R., E-mail: gary@pa.uky.edu [AWE plc, Aldermaston, Reading RG7 4PR (United Kingdom)

2013-04-20T23:59:59.000Z

275

Thermal hard-photons probing multifragmentation in nuclear collisions around the Fermi energy  

E-Print Network [OSTI]

Hard-photon (E$_{\\gamma} >$ 30 MeV) emission issuing from proton-neutron bremsstrahlung collisions is investigated in four different heavy-ion reactions at intermediate bombarding energies ($^{36}$Ar+$^{197}$Au, $^{107}$Ag, $^{58}$Ni, $^{12}$C at 60{\\it A} MeV) coupling the TAPS photon spectrometer with two charged-particle multidetectors covering more than 80% of the solid angle. The hard-photon spectra of the three heavier targets result from the combination of two distinct exponential distributions with different slope parameters, a result which deviates from the behaviour expected for hard-photon production just in first-chance proton-neutron collisions. The thermal origin of the steeper bremsstrahlung component is confirmed by the characteristics of its slope and angular distribution. Such thermal hard-photons convey undisturbed information of the thermodynamical state of hot and excited nuclear systems undergoing multifragmentation.

D. G. d'Enterria; G. Martínez

2000-07-06T23:59:59.000Z

276

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

E-Print Network [OSTI]

ANALYTIC CRITERIA FOR THE MECHANICAL AND THERMAL STABILITY OF MAGNETIC STARS WITH FINITE ELECTRICAL in the envelope. This physical complication also affects the interpretation of the RR Lyrae stars and other cool stars, the destabilized envelope is mostly radiative and convection probably plays only a small role

277

Electrical and Thermal Conductivity of Ge/Si Quantum Dot Superlattices  

E-Print Network [OSTI]

. Good carrier mobility and electric con- ductivity are important for thermoelectric materials where-Riverside, Riverside, California 92521, USA Recently proposed thermoelectric applications of quantum dot superlattices made of different material systems depend crucially on the values of the electrical and thermal

278

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...

279

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

E-Print Network [OSTI]

Voltage (Temperature vs. Time) 21 Block Diagrams of the Temperature Control Systems 23 II-8 Parabolic Reference Voltage (Voltage vs. Time) II-9 System Heating Curves Using the Heater Control System (Temper'ature vs. Time) 25 II-10 Block Diagram.... 10 /Temperature) 32 III-3 Conductivity as Function of Temperature for the TSC Experiment (Conductivity vs. Temperature) I II 4 Carrier Concentration as Function of Temperature for TSC (Carrier Concentration vs. Temperature) 35 LIST OF SYNBOLS...

Bryant, John Duffie

1972-01-01T23:59:59.000Z

280

Thermal conductivity of Er{sup +3}:Y{sub 2}O{sub 3} films grown by atomic layer deposition  

SciTech Connect (OSTI)

Cross-plane thermal conductivity of 800, 458, and 110?nm erbium-doped crystalline yttria (Er{sup +3}:Y{sub 2}O{sub 3}) films deposited via atomic layer deposition was measured using the 3? method at room temperature. Thermal conductivity results show 16-fold increase in thermal conductivity from 0.49?W m{sup ?1}K{sup ?1} to 8?W m{sup ?1}K{sup ?1} upon post deposition annealing, partially due to the suppression of the number of the -OH/H{sub 2}O bonds in the films after annealing. Thermal conductivity of the annealed film was ?70% lower than undoped bulk single crystal yttria. The cumulative interface thermal resistivity of substrate-Er{sup +3}:Y{sub 2}O{sub 3}-metal heater was determined to be ?2.5?×?10{sup ?8} m{sup 2} K/W.

Raeisi Fard, Hafez; Hess, Andrew; Pashayi, Kamyar; Borca-Tasciuc, Theodorian, E-mail: borcat@rpi.edu [Mechanical, Aerospace and Nuclear Engineering Department, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)] [Mechanical, Aerospace and Nuclear Engineering Department, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); Becker, Nicholas; Proslier, Thomas; Pellin, Michael [Material Sciences Division, Argonne National Laboratory 9700 S. Cass Avenue, Lemont, Illinois 60439 (United States)] [Material Sciences Division, Argonne National Laboratory 9700 S. Cass Avenue, Lemont, Illinois 60439 (United States)

2013-11-04T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

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

SciTech Connect (OSTI)

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.

Huang, Hai; Plummer, Mitchell; Podgorney, Robert

2013-02-01T23:59:59.000Z

282

Thermal conductance of the junction between single-walled carbon nanotubes  

E-Print Network [OSTI]

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

McGaughey, Alan

283

Role of Nanostructures in Reducing Thermal Conductivity below Alloy Limit in Crystalline Solids  

E-Print Network [OSTI]

reduce electrical conductivity, making it ineffective for increasing the material's thermoelectric figure conversion devices depends on the thermoelectric figure of merit (ZT) of a material, which is defined as ZT thermoelectric materials [3-5]. While the original goal for nanostructuring was to increase S2 due to quantum

284

Scaling laws for thermal conductivity of crystalline nanoporous silicon based on molecular dynamics simulations  

E-Print Network [OSTI]

is a potentially efficient ther- moelectric material for energy harvesting applications.11,12 Thermoelectric on the temperature and on the material.13 Good thermoelectric materials feature high electrical conductivity and high to the interdependence among r, S, and k.13 As a thermoelectric material, bulk dense crystalline Si is considered

Pilon, Laurent

285

Electron-Phonon Coupling and Thermal Conductance at a Metal-Semiconductor Interface: First-principles Analysis  

E-Print Network [OSTI]

The mechanism of heat transfer and the contribution of electron-phonon coupling to thermal conductance of a metal-semiconductor interface remains unclear in the present literature. We report ab initio simulations of a technologically important titanium silicide (metal) - silicon (semiconductor) interface to estimate the Schottky barrier height (SBH), and the strength of electron-phonon and phonon-phonon heat transfer across the interface. The electron and phonon dispersion relations of TiSi$_2$ with C49 structure and the TiSi$_2$-Si interface are obtained using first-principles calculations within the density functional theory (DFT) framework. These are used to estimate electron-phonon linewidths and the associated Eliashberg function that quantifies coupling. We show that the coupling strength of electrons with interfacial phonon modes is of the same order of magnitude as coupling of electrons to phonon modes in the bulk metal, and its contribution to electron-phonon interfacial conductance is comparable to ...

Sadasivam, Sridhar; Fisher, Timothy S

2015-01-01T23:59:59.000Z

286

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

E-Print Network [OSTI]

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.... EXPERIMENTAL EQUIPMENT AND PROCEDURE All tests were performed on unconsolidated sand packs containing either one, two, or three saturating fluids, Phys- ical properties of the sand and saturating fluids are shown in Tables I and II in the Appendix...

Gore, David Eugene

2012-06-07T23:59:59.000Z

287

Electrical conductivity and charge diffusion in thermal QCD from the lattice  

E-Print Network [OSTI]

We present a lattice QCD calculation of the charge diffusion coefficient, the electrical conductivity and various susceptibilities of conserved charges, for a range of temperatures below and above the deconfinement crossover. The calculations include the contributions from up, down and strange quarks. We find that the diffusion coefficient is of the order of 1/(2\\pi T) and has a dip around the crossover temperature. Our results are obtained with lattice simulations containing 2+1 dynamical flavours on anisotropic lattices. The Maximum Entropy Method is used to construct spectral functions from correlators of the conserved vector current.

Gert Aarts; Chris Allton; Alessandro Amato; Pietro Giudice; Simon Hands; Jon-Ivar Skullerud

2015-02-12T23:59:59.000Z

288

Lattice thermal conductivity of self-assembled PbTe-Sb2Te3 composites with nanometer lamellae Teruyuki Ikeda1  

E-Print Network [OSTI]

. In this work, the thermal conductivities and the electrical resistivities have been measured as functions for effective use of heat or electrical energy, it is essential to discover materials with a high thermoelectric to control the fraction transformed and inter-lamellar spacing. The electrical resistivity and the thermal

289

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

SciTech Connect (OSTI)

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.

Nelson, Andrew T. [Los Alamos National Laboratory

2012-08-30T23:59:59.000Z

290

Thermal Management of Solar Cells  

E-Print Network [OSTI]

a better thermal conductance and when ceramic particles areor ceramic fillers that enhances thermal conductivity. Solid

Saadah, Mohammed Ahmed

2013-01-01T23:59:59.000Z

291

Combined Atomic Force Microscope-Based Topographical Imaging and Nanometer Scale Resolved Proximal Probe Thermal Desorption/Electrospray Ionization-Mass Spectrometry  

SciTech Connect (OSTI)

Nanometer scale proximal probe thermal desorption/electrospray ionization mass spectrometry (TD/ESI-MS) was demonstrated for molecular surface sampling of caffeine from a thin film using a 30 nm diameter nano-thermal analysis (nano-TA) probe tip in an atomic force microscope (AFM) coupled via a vapor transfer line and ESI interface to a MS detection platform. Using a probe temperature of 350 C and a spot sampling time of 30 s, conical desorption craters 250 nm in diameter and 100 nm deep were created as shown through subsequent topographical imaging of the surface within the same system. Automated sampling of a 5 x 2 array of spots, with 2 m spacing between spots, and real time selective detection of the desorbed caffeine using tandem mass spectrometry was also demonstrated. Estimated from the crater volume (~2x106 nm3), only about 10 amol (2 fg) of caffeine was liberated from each thermal desorption crater in the thin film. These results illustrate a relatively simple experimental setup and means to acquire in automated fashion sub-micrometer scale spatial sampling resolution and mass spectral detection of materials amenable to TD. The ability to achieve MS-based chemical imaging with 250 nm scale spatial resolution with this system is anticipated.

Ovchinnikova, Olga S [ORNL; Nikiforov, Maxim [ORNL; Bradshaw, James A [ORNL; Jesse, Stephen [ORNL; Van Berkel, Gary J [ORNL

2011-01-01T23:59:59.000Z

292

Exploration of coal-based pitch precursors for ultra-high thermal conductivity graphite fibers. Final report  

SciTech Connect (OSTI)

Goal was to explore the utility of coal-based pitch precursors for use in ultra high thermal conductivity carbon (graphite) fibers. From graphite electrode experience, it was established that coal-based pitches tend to form more highly crystalline graphite at lower temperatures. Since the funding was limited to year 1 effort of the 3 year program, the goal was only partially achieved. The coal-base pitches can form large domain mesophase in spite of high N and O contents. The mesophase reactivity test performed on one of the variants of coal-based pitch (DO84) showed that it was not a good candidate for carbon fiber processing. Optimization of WVU`s isotropic pitch process is required to tailor the pitch for carbon fiber processing. The hetero atoms in the coal pitch need to be reduced to improve mesophase formation.

Deshpande, G.V. [Amoco Performance Products, Inc., Alpharetta, GA (United States)

1996-12-27T23:59:59.000Z

293

Thermal conductivity of large-grain niobium and its effect on trapped vortices in the temperature range 1.8?5 K  

SciTech Connect (OSTI)

Experimental investigation of the thermal conductivity of large grain and its dependence on the trapped vortices in parallel magnetic field with respect to the temperature gradient {gradient}T was carried out on four large-grain niobium samples from four different ingots. The zero-field thermal conductivity measurements are in good agreement with the measurements based on the theory of Bardeen-Rickayzen-Tewordt (BRT). The change in thermal conductivity with trapped vortices is analysed with the field dependence of the conductivity results of Vinen et al for low inductions and low-temperature situation. Finally, the dependence of thermal conductivity on the applied magnetic field in the vicinity of the upper critical field H{sub c2} is fitted with the theory of pure type-II superconductor of Houghton and Maki. Initial remnant magnetization in the sample shows a departure from the Houghton?Maki curve whereas the sample with zero trapped flux qualitatively agrees with the theory. A qualitative discussion is presented explaining the reason for such deviation from the theory. It has also been observed that if the sample with the trapped vortices is cycled through T{sub c}, the subsequent measurement of the thermal conductivity coincides with the zero trapped flux results.

Mondal, Jayanta [Bhabha Atomic Research Centre; Ciovati, Gianluigi [JLAB; Mittal, Kailash C. [Bhabha Atomic Research Centre; Myneni, Ganapati Rao [JLAB

2012-04-01T23:59:59.000Z

294

Influence of longitudinal isotope substitution on the thermal conductivity of carbon nanotubes: Results of nonequilibrium molecular dynamics and local density functional calculations  

SciTech Connect (OSTI)

We report reverse nonequilibrium molecular dynamics calculations of the thermal conductivity of isotope substituted (10,10) carbon nanotubes (CNTs) at 300 K. {sup 12}C and {sup 14}C isotopes both at 50% content were arranged either randomly, in bands running parallel to the main axis of the CNTs or in bands perpendicular to this axis. It is found that the systems with randomly distributed isotopes yield significantly reduced thermal conductivity. In contrast, the systems where the isotopes are organized in patterns parallel to the CNTs axis feature no reduction in thermal conductivity when compared with the pure {sup 14}C system. Moreover, a reduction of approximately 30% is observed in the system with the bands of isotopes running perpendicular to the CNT axis. The computation of phonon dispersion curves in the local density approximation and classical densities of vibrational states reveal that the phonon structure of carbon nanotubes is conserved in the isotope substituted systems with the ordered patterns, yielding high thermal conductivities in spite of the mass heterogeneity. In order to complement our conclusions on the {sup 12}C-{sup 14}C mixtures, we computed the thermal conductivity of systems where the {sup 14}C isotope was turned into pseudo-atoms of 20 and 40 atomic mass units.

Leroy, Frédéric, E-mail: f.leroy@theo.chemie.tu-darmstadt.de; Böhm, Michael C., E-mail: boehm@theo.chemie.tu-darmstadt.de [Eduard-Zintl-Institut für Anorganische und Physikalische Chemie, Technische Universität Darmstadt, D-64287 Darmstadt (Germany); Schulte, Joachim [Bruker Biospin GmbH, Silberstreifen, D-76287 Rheinstetten (Germany)] [Bruker Biospin GmbH, Silberstreifen, D-76287 Rheinstetten (Germany); Balasubramanian, Ganesh [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)] [Department of Mechanical Engineering, Iowa State University, Ames, Iowa 50011 (United States)

2014-04-14T23:59:59.000Z

295

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

E-Print Network [OSTI]

and this broadened our insight into the problems encountered with thermal management materials. As a result, we for Thermal Management: Key issues: Thermal management Macrocyclic oligomers with ultra-low melt viscosity PBT (CBT) oligomers for thermal management. We also acknowledge the support of Cool Polymers in Warwick, RI

Harmon, Julie P.

296

Cylindrical thermal contact conductance  

E-Print Network [OSTI]

of superconducting wires, tension-wound finned tubes, and large diameter pipes. Thick cylindrical shells (including solid composite cylinders) may occur in such applications as nuclear fuel rods and composite pipes. Cylindrical joints behave differently than flat...

Ayers, George Harold

2004-09-30T23:59:59.000Z

297

Intersublevel optical transitions in InAs nanocrystals probed by photoinduced absorption spectroscopy: The role of thermal activation  

E-Print Network [OSTI]

of well-defined envelope-state symmetry relations while the second attributes the thermal activation spectroscopy: The role of thermal activation D. Krapf,1 S.-H. Kan,2 U. Banin,2 O. Millo,3 and A. Sa'ar1,3, * 1 have found that the valence intersublevel transitions are thermally activated and cannot be observed

Krapf, Diego

298

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]

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.

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

2011-11-23T23:59:59.000Z

299

MEMS test structure for measuring thermal conductivity of thin films L. La Spina, N. Nenadovi*, A. W. van Herwaarden**,  

E-Print Network [OSTI]

from handbook values for the corresponding bulk materials. This is because the thermal transport the one is patterned with the film-to- analyze (FTA). In this case, the thermal resistance can be regarded as a parallel between the thermal resistances of the supporting membrane and of the FTA. Thus, the measured

Technische Universiteit Delft

300

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]

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

Virginia Tech

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

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

SciTech Connect (OSTI)

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.

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

2014-03-10T23:59:59.000Z

302

Anisotropic thermal conduction in polymer melts in uniaxial elongation Sahil Gupta, Jay D. Schieber, and David C. Venerus  

E-Print Network [OSTI]

diffusivity tensor as a function of strain and strain rate. The thermal diffusivity is found to increase Published by the The Society of Rheology Related Articles A thin-filament melt spinning model with radial based on forced Rayleigh scattering is used to measure the two independent components of the thermal

Schieber, Jay D.

303

THERMAL TECHNIQUES FOR THE IN-SITU CHARACTERIZATION AND REMEDIATION OF MERCURY: INSIGHTS FROM DEPLOYMENT OF THE MEMBRANE INTERFACE PROBE  

SciTech Connect (OSTI)

This presentation focuses on how thermal energy can effectively be used to enhance characterization, promote the remediation, and aid in delivering a sequestering agent to stabilize elemental mercury in subsurface soils. Slides and speaker notes are provided.

Jackson, Dennis; Looney, Brian; Eddy-Dilek, Carol A.

2013-08-07T23:59:59.000Z

304

Experimental Measurement of the Interface Heat Conductance Between Nonconforming Beryllium and Type 316 Stainless Steel Surfaces Subjected to Nonuniform Thermal Deformations  

SciTech Connect (OSTI)

In fusion blanket designs that employ beryllium as a neutron multiplier, the interface conductance h plays a key role in evaluating the blanket's thermal profile. Therefore, an extensive experimental program was conducted to measure the magnitude of h between nonconforming beryllium and Type 316 stainless steel surfaces subjected to nonuniform thermal deformations. The magnitude of h was measured as a function of relevant environmental, surface, and geometric parameters, including surface roughness, contact pressure, gas pressure, gas type, and magnitude and direction of heat flow. The results indicate the following: (a) Decreasing the interfacial surface roughness from 6.28 to 0.28 {mu}m, in 760 Torr of helium, increased the magnitude of h by up to 100%; however, increasing the surface roughness reduced the dependence of h on the magnitude of the contact pressure. (b) The interface conductance was significantly higher for measurements made in helium gas as opposed to air. Additionally, the sensitivity of h to the gas pressure was significantly greater for runs conducted in helium and/or with smoother surfaces. This sensitivity was reduced in air and/or with roughened surfaces, and it was essentially nonexistent for the 6.25-{mu}m specimen for air pressures exceeding 76 Torr. (c) For runs conducted in vacuum, the interface conductance was more sensitive to heat flux than when runs were conducted in 760 Torr of helium. (d) The interface conductance was found to be dependent on the direction of heat flux. When the specimens were arranged so that heat flowed from the steel to the beryllium disk, the magnitude of h was generally greater than in the opposite direction.

Abelson, Robert Dean; Abdou, Mohamed A. [University of California, Los Angeles (United States)

2001-03-15T23:59:59.000Z

305

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

SciTech Connect (OSTI)

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.

Kolodiazhnyi, T., E-mail: kolodiazhnyi.taras@nims.go.jp; Sakurai, H.; Vasylkiv, O.; Borodianska, H. [National Institute for Materials Science, Tsukuba, Ibaraki 305-0044 (Japan); Mozharivskyj, Y. [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S4M1 (Canada)

2014-03-17T23:59:59.000Z

306

1981). Their basic solution is to find a suitable backfilling material to minimize the contact resistance and to maintain high ground thermal conductivity around the cable even under very  

E-Print Network [OSTI]

resistance and to maintain high ground thermal conductivity around the cable even under very dry ground#12;1981). Their basic solution is to find a suitable backfilling material to minimize the contact thermal conductivity for clay backfilling, measured 1/2 inch and 6 inches (1.3 and 15 cm) away from

Oak Ridge National Laboratory

307

TRANSPORT INVOLVING CONDUCTING FIBERS IN A NON-CONDUCTING MATRIX  

E-Print Network [OSTI]

result is a material with high electrical conductivity and low thermal conductivity. Transport Models,2 , J. Rozen3 Introduction Thermal and electrical transport through a low-conductivity matrix containing conversion devices high electrical conductivity and low thermal conductivity are preferred for superior

Walker, D. Greg

308

hal-00111982,version2-9May2007 Effect of measurement probes upon the conductance of an interacting nano-system  

E-Print Network [OSTI]

nano-system: Detection of an attached ring by non local many body effects Axel Freyn and Jean-sur-Yvette Cedex, France We consider a nano-system connected to measurement probes via leads. When a magnetic flux is varied through a ring attached to one lead at a distance Lc from the nano-system, the effective nano

Paris-Sud XI, Université de

309

Cross-plane lattice and electronic thermal conductivities of ErAs:InGaAs/InGaAlAs superlattices  

E-Print Network [OSTI]

of thermoelectric energy conversion devices depends on the thermoelectric figure of merit ZT of a material, which the electronic thermal con- ductivity of thermoelectric materials is proportional to their electrical Joshua M. O. Zide and Arthur C. Gossard Department of Materials, University of California, Santa Barbara

310

A three dimensional simulation of a thermal experiment conducted on an accelerator driven system target model concept  

E-Print Network [OSTI]

dynamics (CFD). The benchmark for the model comparison is an experiment conducted by the Institute of Physics and Power Engineering on one particular ATW system concept. The experimenters used thermocouples to determine the temperature profile...

Pratt, Preston Persley

2003-01-01T23:59:59.000Z

311

Thermal Conductivity of Ordered Mesoporous Titania Films Made from Nanocrystalline Building Blocks and Sol-Gel Reagents  

E-Print Network [OSTI]

significant attention due to their wide range of applications. They have been used in dye-sensitized solar cells for their wide band gap semiconductor properties.1 They have also been considered for solid oxide fuel cells as high proton conductivity porous exchange membranes.2 Mesoporous TiO2 is also a very

Pilon, Laurent

312

Nanoscale thermal transport. II. 2003–2012  

SciTech Connect (OSTI)

A diverse spectrum of technology drivers such as improved thermal barriers, higher efficiency thermoelectric energy conversion, phase-change memory, heat-assisted magnetic recording, thermal management of nanoscale electronics, and nanoparticles for thermal medical therapies are motivating studies of the applied physics of thermal transport at the nanoscale. This review emphasizes developments in experiment, theory, and computation in the past ten years and summarizes the present status of the field. Interfaces become increasingly important on small length scales. Research during the past decade has extended studies of interfaces between simple metals and inorganic crystals to interfaces with molecular materials and liquids with systematic control of interface chemistry and physics. At separations on the order of ?1?nm, the science of radiative transport through nanoscale gaps overlaps with thermal conduction by the coupling of electronic and vibrational excitations across weakly bonded or rough interfaces between materials. Major advances in the physics of phonons include first principles calculation of the phonon lifetimes of simple crystals and application of the predicted scattering rates in parameter-free calculations of the thermal conductivity. Progress in the control of thermal transport at the nanoscale is critical to continued advances in the density of information that can be stored in phase change memory devices and new generations of magnetic storage that will use highly localized heat sources to reduce the coercivity of magnetic media. Ultralow thermal conductivity—thermal conductivity below the conventionally predicted minimum thermal conductivity—has been observed in nanolaminates and disordered crystals with strong anisotropy. Advances in metrology by time-domain thermoreflectance have made measurements of the thermal conductivity of a thin layer with micron-scale spatial resolution relatively routine. Scanning thermal microscopy and thermal analysis using proximal probes has achieved spatial resolution of 10?nm, temperature precision of 50 mK, sensitivity to heat flows of 10 pW, and the capability for thermal analysis of sub-femtogram samples.

Cahill, David G., E-mail: d-cahill@illinois.edu; Braun, Paul V. [Department of Materials Science and Engineering and the Frederick Seitz Materials Research Laboratory, University of Illinois, Urbana, Illinois 61801 (United States); Chen, Gang [Department of Mechanical Engineering, MIT, Cambridge, Massachusetts 02139 (United States); Clarke, David R. [School of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138 (United States); Fan, Shanhui [Department of Electrical Engineering, Stanford University, Stanford, California 94305 (United States); Goodson, Kenneth E. [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Keblinski, Pawel [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States); King, William P. [Department of Mechanical Sciences and Engineering, University of Illinois, Urbana, Illinois 61801 (United States); Mahan, Gerald D. [Department of Physics, Penn State University, University Park, Pennsylvania 16802 (United States); Majumdar, Arun [Department of Mechanical Engineering, University of California, Berkeley, California 94720 (United States); Maris, Humphrey J. [Department of Physics, Brown University, Providence, Rhode Island 02912 (United States); Phillpot, Simon R. [Department of Materials Science and Engineering, University of Florida, Gainseville, Florida 32611 (United States); Pop, Eric [Department of Electrical and Computer Engineering, University of Illinois, Urbana, Illinois 61801 (United States); Shi, Li [Department of Mechanical Engineering, University of Texas, Autin, Texas 78712 (United States)

2014-03-15T23:59:59.000Z

313

Calonne, N., F. Flin, S. Morin, B. Lesaffre, S. Rolland du Roscoat, and C. Geindreau (2011), Numerical and experimental investigations of the effective thermal conductivity of snow, Geophys. Res. Lett., doi:10.1029/2011GL049234.  

E-Print Network [OSTI]

., doi:10.1029/2011GL049234. - 1 - Numerical and Experimental Investigations of the Effective Thermal. Res. Lett., doi:10.1029/2011GL049234. - 2 - Table of Contents and General Information Table investigations of the effective thermal conductivity of snow, Geophys. Res. Lett., doi:10.1029/2011GL049234. - 3

Ribes, Aurélien

314

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]

Besides these questions regarding the efficiency of condensation or thermal conduction in the inner,12], but irradiation efficiency ~uncertain EC evaporation/condensation [13,14,15,16] between thermally-coupled disk setting to study accretion ­ a high mass supply rate (via Roche- lobe overflow [1,2]) avoids onset

California at Santa Cruz, University of

315

TRANSPORT INVOLVING CONDUCTING FIBERS IN A NON-CONDUCTING MATRIX  

E-Print Network [OSTI]

to sev- eral applications including flexible thin-film transistors, PEM fuel cells, and direct energy, particularly Peltier devices, high electrical conductivity and low thermal conductivity are preferred

Walker, D. Greg

316

High temperature electrochemical corrosion rate probes  

SciTech Connect (OSTI)

Corrosion occurs in the high temperature sections of energy production plants due to a number of factors: ash deposition, coal composition, thermal gradients, and low NOx conditions, among others. Electrochemical corrosion rate (ECR) probes have been shown to operate in high temperature gaseous environments that are similar to those found in fossil fuel combustors. ECR probes are rarely used in energy production plants at the present time, but if they were more fully understood, corrosion could become a process variable at the control of plant operators. Research is being conducted to understand the nature of these probes. Factors being considered are values selected for the Stern-Geary constant, the effect of internal corrosion, and the presence of conductive corrosion scales and ash deposits. The nature of ECR probes will be explored in a number of different atmospheres and with different electrolytes (ash and corrosion product). Corrosion rates measured using an electrochemical multi-technique capabilities instrument will be compared to those measured using the linear polarization resistance (LPR) technique. In future experiments, electrochemical corrosion rates will be compared to penetration corrosion rates determined using optical profilometry measurements.

Bullard, Sophie J.; Covino, Bernard S., Jr.; Holcomb, Gordon R.; Ziomek-Moroz, M.

2005-09-01T23:59:59.000Z

317

Low-temperature thermal conductivity of antiferromagnetic S?=?1/2 chain material CuCl{sub 2}·2((CH{sub 3}){sub 2}SO)  

SciTech Connect (OSTI)

We study the heat transport of S?=?1/2 chain compound CuCl{sub 2}·2((CH{sub 3}){sub 2}SO) along the b axis (vertical to the chain direction) at very low temperatures. The zero-field thermal conductivity (?) shows a distinct kink at about 0.9?K, which is related to the long-range antiferromagnetic (AF) transition. With applying magnetic field along the c axis, ?(H) curves also show distinct changes at the phase boundaries between the AF and the high-field disordered states. These results indicate a strong spin-phonon interaction and the magnetic excitations play a role in the b-axis heat transport as phonon scatterers.

Ke, W. P.; Zhang, F. B.; Zhao, Z. Y.; Fan, C.; Sun, X. F., E-mail: xfsun@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Shi, J. [Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Zhao, X., E-mail: xiazhao@ustc.edu.cn [School of Physical Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2014-05-07T23:59:59.000Z

318

Catheter based magnetic resonance compatible perfusion probe  

E-Print Network [OSTI]

Neurosurgeons are using a thermal based technique to quantify brain perfusion. The thermal diffusion probe (TDP) technology measures perfusion in a relatively small volume of brain tissue. The neurosurgeon chooses the ...

Toretta, Cara Lynne

2007-01-01T23:59:59.000Z

319

Individual quantum probes for optimal thermometry  

E-Print Network [OSTI]

The unknown temperature of a sample may be estimated with minimal disturbance by putting it in thermal contact with an individual quantum probe. If the interaction time is sufficiently long so that the probe thermalizes, the temperature can be read out directly from its steady state. Here we prove that the optimal quantum probe, acting as a thermometer with maximal thermal sensitivity, is an effective two-level atom with a maximally degenerate excited state. When the total interaction time is insufficient to produce full thermalization, we optimize the estimation protocol by breaking it down into sequential stages of probe preparation, thermal contact and measurement. We observe that frequently interrogated probes initialized in the ground state achieve the best performance. For both fully and partly thermalized thermometers, the sensitivity grows significantly with the number of levels, though optimization over their energy spectrum remains always crucial.

Luis A. Correa; Mohammad Mehboudi; Gerardo Adesso; Anna Sanpera

2014-11-23T23:59:59.000Z

320

Spectrophotometric probe  

DOE Patents [OSTI]

A support structure is described bearing at least one probe for making spectrophotometric measurements of a fluid using a source of light and a spectrophotometer. The probe includes a housing with two optical fibers and a planoconvex lens. A sleeve bearing a mirror surrounds the housing. The lens is separated from the mirror by a fixed distance, defining an interior space for receiving a volume of the fluid sample. A plurality of throughholes extending through the sleeve communicate between the sample volume and the exterior of the probe, all but one hole bearing a screen. A protective jacket surrounds the probe. A hollow conduit bearing a tube is formed in the wall of the probe for venting any air in the interior space when fluid enters. The probe is held at an acute angle so the optic fibers carrying the light to and from the probe are not bent severely on emergence from the probe. 3 figs.

Prather, W.S.; O'Rourke, P.E.

1994-08-02T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Thermal conductivity control by oxygen defect concentration modification in reducible oxides: The case of Pr{sub 0.1}Ce{sub 0.9}O{sub 2??} thin films  

SciTech Connect (OSTI)

We demonstrate the impact on thermal conductivity of varying the concentration of oxygen vacancies and reduced cations in Pr{sub 0.1}Ce{sub 0.9}O{sub 2??} thin films prepared by pulsed laser deposition. The oxygen vacancy concentration is controlled by varying the oxygen partial pressure between 1?×?10{sup ?4} and 1?atm at 650??°C. Corresponding changes in the oxygen non-stoichiometry (?) are monitored by detecting the lattice parameters of the films with high-resolution X-ray diffraction, while the thermal properties are characterized by time-domain thermoreflectance measurements. The films are shown to exhibit a variation in oxygen vacancy content, and in the Pr{sup 3+}/Pr{sup 4+} ratio, corresponding to changes in ? from 0.0027 to 0.0364, leading to a reduction in the thermal conductivity from k?=?6.62?±?0.61 to 3.82?±?0.51?W/m-K, respectively. These values agree well with those predicted by the Callaway and von Baeyer model for thermal conductivity in the presence of point imperfections. These results demonstrate the capability of controlling thermal conductivity via control of anion and cation defect concentrations in a given reducible oxide.

Luckyanova, Maria N.; Chen, Gang, E-mail: gchen2@mit.edu, E-mail: byildiz@mit.edu [Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Chen, Di; Tuller, Harry L. [Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Ma, Wen; Yildiz, Bilge, E-mail: gchen2@mit.edu, E-mail: byildiz@mit.edu [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2014-02-10T23:59:59.000Z

322

Calonne, N., F. Flin, S. Morin, B. Lesaffre, S. Rolland du Roscoat, and C. Geindreau (2011), Numerical and experimental investigations of the effective thermal conductivity of snow, Geophys. Res. Lett., doi:10.1029/2011GL049234, in press.  

E-Print Network [OSTI]

., doi:10.1029/2011GL049234, in press. - 1 - Numerical and Experimental Investigations of the Effective, Geophys. Res. Lett., doi:10.1029/2011GL049234, in press. - 2 - Table of Contents and General Information of the effective thermal conductivity of snow, Geophys. Res. Lett., doi:10.1029/2011GL049234, in press. - 3 - List

Ribes, Aurélien

323

Mach flow angularity probes for scramjet engine flow path diagnostics  

SciTech Connect (OSTI)

Mach-flow angularity (MFA) probes were developed for use in scramjet flow path probe rakes. Prototype probes were fabricated to demonstrate the assembly processes (numerical control machining, furnace brazing, and electron beam welding). Tests of prototype probes confirmed the thermal durability margins and life cycle. Selected probes were calibrated in air at Mach numbers from 1.75 to 6.0. Acceptance criteria for the production probes stressed thermal durability and pressure (and, consequently, Mach number) measurement quality. This new water-cooled MFA probe has 0.397-cm shaft diameter and is capable of withstanding heat fluxes of 2.724 kW/sq cm.

Jalbert, P.A.; Hiers, R.S. Jr. [Sverdrup Technology, Inc., Arnold AFS, TN (United States)

1993-12-31T23:59:59.000Z

324

Rotating concave eddy current probe  

SciTech Connect (OSTI)

A rotating concave eddy current probe for detecting fatigue cracks hidden from view underneath the head of a raised head fastener, such as a buttonhead-type rivet, used to join together structural skins, such as aluminum aircraft skins. The probe has a recessed concave dimple in its bottom surface that closely conforms to the shape of the raised head. The concave dimple holds the probe in good alignment on top of the rivet while the probe is rotated around the rivet's centerline. One or more magnetic coils are rigidly embedded within the probe's cylindrical body, which is made of a non-conducting material. This design overcomes the inspection impediment associated with widely varying conductivity in fastened joints.

Roach, Dennis P. (Albuquerque, NM); Walkington, Phil (Albuquerque, NM); Rackow, Kirk A. (Albuquerque, NM); Hohman, Ed (Albuquerque, NM)

2008-04-01T23:59:59.000Z

325

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]

performed as a function of mechanical inplane strain levels, heating rates, and number of thermal cycles. The apparatus generated cracks related to the in-plane stresses (or strains) on plies. The design and analysis concept of the synergistic stress...

Ju, Jaehyung

2006-10-30T23:59:59.000Z

326

Report on workshop on thermal property measurements  

SciTech Connect (OSTI)

Results of thermogravimetric analysis of basalt is discussed. Heat capacity, thermal conductivity and thermal expansion are specifically addressed. (CBS)

Robertson, E.C.

1987-01-01T23:59:59.000Z

327

Thermal insulations using vacuum panels  

DOE Patents [OSTI]

Thermal insulation vacuum panels are formed of an inner core of compressed low thermal conductivity powders enclosed by a ceramic/glass envelope evaluated to a low pressure.

Glicksman, Leon R. (Lynnfield, MA); Burke, Melissa S. (Pittsburgh, PA)

1991-07-16T23:59:59.000Z

328

Thermal Characterization of Graphitic Carbon Foams for Use in Thermal Storage Applications.  

E-Print Network [OSTI]

?? Highly conductive graphitic foams are currently being studied for use as thermal conductivity enhancers (TCEs) in thermal energy storage (TES) systems. TES systems store… (more)

Drummond, Kevin P.

2012-01-01T23:59:59.000Z

329

Laser irradiation of carbon nanotube films: Effects and heat dissipation probed by Raman spectroscopy  

SciTech Connect (OSTI)

We investigate the thermal properties of thin films formed by single- and multi-walled carbon nanotubes submitted to laser irradiation using Raman scattering as a probe of both the tube morphology and the local temperature. The nanotubes were submitted to heating/cooling cycles attaining high laser intensities ({approx}1.4 MW/cm{sup 2}) under vacuum and in the presence of an atmosphere, with and without oxygen. We investigate the heat diffusion of the irradiated nanotubes to their surroundings and the effect of laser annealing on their properties. The presence of oxygen during laser irradiation gives rise to an irreversible increase of the Raman efficiency of the carbon nanotubes and to a remarkable increase of the thermal conductivity of multi-walled films. The second effect can be applied to design thermal conductive channels in devices based on carbon nanotube films using laser beams.

Mialichi, J. R.; Brasil, M. J. S. P.; Iikawa, F. [Instituto de Fisica 'Gleb Wataghin,' Unicamp, Campinas, 13083-859 Sao Paulo (Brazil); Verissimo, C.; Moshkalev, S. A. [Centro de Componentes Semicondutores, Unicamp, Campinas, 13083-870 Sao Paulo (Brazil)

2013-07-14T23:59:59.000Z

330

Thermal unobtainiums? The perfect thermal conductor and  

E-Print Network [OSTI]

contribute to thermal resistance · Isotopically pure diamond has highest thermal conductivity of any material materials: disordered layered crystals Conclude with some thoughts on promising, high-risk, research even in a computer model. #12;Thermal resistance is created by Umklapp scattering (U

Braun, Paul

331

Transport involving conducting fibers in a non-conducting matrix R. A. Hansela  

E-Print Network [OSTI]

result is a material with high electrical conduc- tivity and low thermal conductivity. If we consider, conducting fibers, thin-film devices 1. Introduction Thermal and electrical transport through a low to predict conductance of the combined system. However, if the two materials are similar in conductivity

Walker, D. Greg

332

Variable pressure thermal insulating jacket  

DOE Patents [OSTI]

A device for controlled insulation of a thermal device is disclosed. The device includes a thermal jacket with a closed volume able to be evacuated to form an insulating jacket around the thermal source. A getter material is in communication with the closed volume of the thermal jacket. The getter material can absorb and desorb a control gas to control gas pressure in the volume of the thermal jacket to control thermal conductivity in the thermal jacket. 10 figs.

Nelson, P.A.; Malecha, R.F.; Chilenskas, A.A.

1994-09-20T23:59:59.000Z

333

Optimized Structures for Low-Profile Phase Change Thermal Spreaders  

E-Print Network [OSTI]

of High-Thermal-Conductivity Aluminum Nitride Ceramics”,for a ceramic isolating material and the associated thermal

Sharratt, Stephen A.

2012-01-01T23:59:59.000Z

334

Conduction cooled tube supports  

DOE Patents [OSTI]

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.

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

1984-01-01T23:59:59.000Z

335

Conduction cooling: multicrate fastbus hardware  

SciTech Connect (OSTI)

Described is a new and novel approach for cooling nuclear instrumentation modules via heat conduction. The simplicity of liquid cooled crates and ease of thermal management with conduction cooled modules are described. While this system was developed primarily for the higher power levels expected with Fastbus electronics, it has many general applications.

Makowiecki, D.; Sims, W.; Larsen, R.

1980-11-01T23:59:59.000Z

336

Probing and Controlling Photothermal Heat Generation in Plasmonic Nanostructures  

E-Print Network [OSTI]

thermal hotspots. In the present study, new methods for designing and thermally probing thermoplasmonic suitable for heat generation compared with its more well-known complementary structure, the bow-tie antenna. We also demonstrate that highly localized and enhanced thermal hot spots can be realized

Simaan, Nabil

337

Measurements of Electron Thermal Transport due to Electron Temperature Gradient Modes in a Basic Experiment  

SciTech Connect (OSTI)

Production and identification of electron temperature gradient modes have already been reported [X. Wei, V. Sokolov, and A. K. Sen, Phys. Plasmas 17, 042108 (2010)]. Now a measurement of electron thermal conductivity via a unique high frequency triple probe yielded a value of {chi}{sub perpendiculare} ranging between 2 and 10 m{sup 2}/s, which is of the order of a several gyrobohm diffusion coefficient. This experimental result appears to agree with a value of nonlocal thermal conductivity obtained from a rough theoretical estimation and not inconsistent with gyrokinetic simulation results for tokamaks. The first experimental scaling of the thermal conductivity versus the amplitude of the electron temperature gradient fluctuation is also obtained. It is approximately linear, indicating a strong turbulence signature.

Sokolov, V.; Sen, A. K. [Plasma Research Laboratory, Columbia University, New York, New York 10027 (United States)

2011-10-07T23:59:59.000Z

338

M. Bahrami ENSC 388 (F09) Steady Conduction Heat Transfer 1 Steady Heat Conduction  

E-Print Network [OSTI]

of the material. In the limiting case where x0, the equation above reduces to the differential form: W dx dT k is the only energy interaction; the energy balance for the wall can be expressed: dt dE QQ wall outin). Thermal Conductivity Thermal conductivity k [W/mK] is a measure of a material's ability to conduct heat

Bahrami, Majid

339

Majorana Demonstrator Bolted Joint Mechanical and Thermal Analysis  

SciTech Connect (OSTI)

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.

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

2012-06-01T23:59:59.000Z

340

Device for thermal transfer and power generation  

DOE Patents [OSTI]

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.

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

2011-04-19T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Thermal Conductivity of Polycrystalline Semiconductors and Ceramics  

E-Print Network [OSTI]

RTG refers to radioisotope thermoelectric generator with aRTG refers to radioisotope thermoelectric generator with a

Wang, Zhaojie

2012-01-01T23:59:59.000Z

342

Thermal Conduction in Graphene and Graphene Multilayers  

E-Print Network [OSTI]

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

Ghosh, Suchismita

2009-01-01T23:59:59.000Z

343

Conductive Thermal Interaction in Evaporative Cooling Process  

E-Print Network [OSTI]

be considered. Usually the dry-bulb depression performed by an evaporative cooler depends solely on the ambient wet-bulb temperature. The cool underground water in an evaporative cooler can cause not only adiabatic evaporation but also sensible heat transfer...

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

1990-01-01T23:59:59.000Z

344

Effects of Thermal Conductivity Ratio in  

E-Print Network [OSTI]

Single jet-impingement design Dimensions similar to HEMP Constructed of C36000 brass alloy Heated on HEMP design at 10 MW/m2 Re = 7.6104 at central port Experiments: 1104

345

Conductive Polymers  

SciTech Connect (OSTI)

Electroluminescent devices such as light-emitting diodes (LED) and high-energy density batteries. These new polymers offer cost savings, weight reduction, ease of processing, and inherent rugged design compared to conventional semiconductor materials. The photovoltaic industry has grown more than 30% during the past three years. Lightweight, flexible solar modules are being used by the U.S. Army and Marine Corps for field power units. LEDs historically used for indicator lights are now being investigated for general lighting to replace fluorescent and incandescent lights. These so-called solid-state lights are becoming more prevalent across the country since they produce efficient lighting with little heat generation. Conductive polymers are being sought for battery development as well. Considerable weight savings over conventional cathode materials used in secondary storage batteries make portable devices easier to carry and electric cars more efficient and nimble. Secondary battery sales represent an $8 billion industry annually. The purpose of the project was to synthesize and characterize conductive polymers. TRACE Photonics Inc. has researched critical issues which affect conductivity. Much of their work has focused on production of substituted poly(phenylenevinylene) compounds. These compounds exhibit greater solubility over the parent polyphenylenevinylene, making them easier to process. Alkoxy substituted groups evaluated during this study included: methoxy, propoxy, and heptyloxy. Synthesis routes for production of alkoxy-substituted poly phenylenevinylene were developed. Considerable emphasis was placed on final product yield and purity.

Bohnert, G.W.

2002-11-22T23:59:59.000Z

346

Thermal control structure and garment  

DOE Patents [OSTI]

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.

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

2012-03-13T23:59:59.000Z

347

Hydrodynamic ultrasonic probe  

DOE Patents [OSTI]

An improved probe for in-service ultrasonic inspection of long lengths of a workpiece, such as small diameter tubing from the interior. The improved probe utilizes a conventional transducer or transducers configured to inspect the tubing for flaws and/or wall thickness variations. The probe utilizes a hydraulic technique, in place of the conventional mechanical guides or bushings, which allows the probe to move rectilinearly or rotationally while preventing cocking thereof in the tube and provides damping vibration of the probe. The probe thus has lower friction and higher inspection speed than presently known probes.

Day, Robert A. (Livermore, CA); Conti, Armond E. (San Jose, CA)

1980-01-01T23:59:59.000Z

348

The dynamics and high-energy emission of conductive gas clouds in supernova-driven galactic superwinds  

E-Print Network [OSTI]

In this paper we present high-resolution hydrodynamical models of warm ionized clouds embedded in a superwind, and compare the OVI and soft X-ray properties to the existing observational data. These models include thermal conduction, which we show plays an important role in shaping both the dynamics and radiative properties of the resulting wind/cloud interaction. Heat conduction stabilizes the cloud by inhibiting the growth of K-H and R-T instabilities, and also generates a shock wave at the cloud's surface that compresses the cloud. This dynamical behaviour influences the observable properties. We find that while OVI emission and absorption always arises in cloud material at the periphery of the cloud, most of the soft X-ray arises in the region between the wind bow shock and the cloud surface, and probes either wind or cloud material depending on the strength of conduction and the relative abundances of the wind with respect to the cloud. In general only a small fraction (thermal conduction, in particular in terms of the OVI-to-X-ray luminosity ratio, but cloud life times are uncomfortably short (thermal conductivity and found that even when we reduced conduction by a factor of 25 that the simulations retained the beneficial hydrodynamical stability and low O{\\sc vi}-to-X-ray luminosity ratio found in the Spitzer-level conductive models, while also having reduced evaporation rates.

A. Marcolini; D. K. Strickland; A. D'Ercole; T. M. Heckman; C. G. Hoopes

2005-06-27T23:59:59.000Z

349

Light and Fast: Probing Carriers and Vibrations in 1D and 2D...  

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

and mechanical, are simultaneously important. First, we will discuss ultrafast optoelectronic measurements of graphene p-n junctions that probe the fundamental thermal...

350

Tunable thermal link  

DOE Patents [OSTI]

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.

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

2014-07-15T23:59:59.000Z

351

Rugged fiber optic probe for raman measurement  

DOE Patents [OSTI]

An optical probe for conducting light scattering analysis is disclosed. The probe comprises a hollow housing and a probe tip. A fiber assembly made up of a transmitting fiber and a receiving bundle is inserted in the tip. A filter assembly is inserted in the housing and connected to the fiber assembly. A signal line from the light source and to the spectrometer also is connected to the filter assembly and communicates with the fiber assembly. By using a spring-loaded assembly to hold the fiber connectors together with the in-line filters, complex and sensitive alignment procedures are avoided. The close proximity of the filter assembly to the probe tip eliminates or minimizes self-scattering generated by the optical fiber. Also, because the probe can contact the sample directly, sensitive optics can be eliminated.

O'Rourke, Patrick E. (Martinez, GA); Toole, Jr., William R. (Aiken, SC); Nave, Stanley E. (Evans, GA)

1998-01-01T23:59:59.000Z

352

Thermoelectrics Combined with Solar Concentration for Electrical and Thermal Cogeneration  

E-Print Network [OSTI]

Since the ceramic wafers have a high thermal conductivity,easily altered ceramic blocks all had a thermal conductivityCeramics. Available Online: http://www.dynacer.com/thermal_

Jackson, Philip Robert

2012-01-01T23:59:59.000Z

353

Article for thermal energy storage  

DOE Patents [OSTI]

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.

Salyer, Ival O. (Dayton, OH)

2000-06-27T23:59:59.000Z

354

Thermal protection apparatus  

DOE Patents [OSTI]

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.

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

1984-03-20T23:59:59.000Z

355

Thermal protection apparatus  

DOE Patents [OSTI]

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.

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

1985-01-01T23:59:59.000Z

356

Ultrafast scanning probe microscopy  

DOE Patents [OSTI]

An ultrafast scanning probe microscopy method for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample.

Weiss, Shimon (El Cerrito, CA); Chemla, Daniel S. (Kensington, CA); Ogletree, D. Frank (El Cerrito, CA); Botkin, David (San Francisco, CA)

1995-01-01T23:59:59.000Z

357

Ultrafast scanning probe microscopy  

DOE Patents [OSTI]

An ultrafast scanning probe microscopy method is described for achieving subpicosecond-temporal resolution and submicron-spatial resolution of an observation sample. In one embodiment of the present claimed invention, a single short optical pulse is generated and is split into first and second pulses. One of the pulses is delayed using variable time delay means. The first pulse is then directed at an observation sample located proximate to the probe of a scanning probe microscope. The scanning probe microscope produces probe-sample signals indicative of the response of the probe to characteristics of the sample. The second pulse is used to modulate the probe of the scanning probe microscope. The time delay between the first and second pulses is then varied. The probe-sample response signal is recorded at each of the various time delays created between the first and second pulses. The probe-sample response signal is then plotted as a function of time delay to produce a cross-correlation of the probe sample response. In so doing, the present invention provides simultaneous subpicosecond-temporal resolution and submicron-spatial resolution of the sample. 6 Figs.

Weiss, S.; Chemla, D.S.; Ogletree, D.F.; Botkin, D.

1995-05-16T23:59:59.000Z

358

Molecular Dynamics Simulations of Heat Conduction in Nanostructures: Effect of Heat Bath  

E-Print Network [OSTI]

temperature profile and thermal conductivity in homogeneous materials. Furthermore, the thermal rectification) The low thermal conductivity of SiNWs is of particular interest for thermoelectric application.10 point of view. On the one hand, superior thermal conductivity has been observed in graphene1

Li, Baowen

359

Thermal Fluids  

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

Thermal Fluids The Thermal Fluids and Heat Transfer program works on thermal hydraulic reactor safety code development and experimental heat transferthermal hydraulics. The...

360

Probing Signal Design for Power System Identification  

SciTech Connect (OSTI)

This paper investigates the design of effective input signals for low-level probing of power systems. In 2005, 2006, and 2008 the Western Electricity Coordinating Council (WECC) conducted four large-scale system wide tests of the western interconnected power system where probing signals were injected by modulating the control signal at the Celilo end of the Pacific DC intertie. A major objective of these tests is the accurate estimation of the inter-area electromechanical modes. A key aspect of any such test is the design of an effective probing signal that leads to measured outputs rich in information about the modes. This paper specifically studies low-level probing signal design for power-system identification. The paper describes the design methodology and the advantages of this new probing signal which was successfully applied during these tests. This probing input is a multi-sine signal with its frequency content focused in the range of the inter-area modes. The period of the signal is over two minutes providing high-frequency resolution. Up to 15 cycles of the signal are injected resulting in a processing gain of 15. The resulting system response is studied in the time and frequency domains. Because of the new probing signal characteristics, these results show significant improvement in the output SNR compared to previous tests.

Pierre, John W.; Zhou, Ning; Tuffner, Francis K.; Hauer, John F.; Trudnowski, Daniel J.; Mittelstadt, William

2010-05-31T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Non-contact Nondestructive Probing of Charge Carrier Conductivity...  

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

transport processes at interfaces is one of the most important subjects in organic electronics. Charge carriers are injected or extracted through metalsemiconductor...

362

Non-contact Nondestructive Probing of Charge Carrier Conductivity in  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas Conchas recoveryLaboratory | NationalJohn

363

Electrical probe diagnostics for the laminar flame quenching distance  

SciTech Connect (OSTI)

A simplified theory, previously developed for the general case of weakly ionized gas flow, is used to predict electrical probe response when the flame is quenched on the probe surface. This theory is based on the planar model of space charge sheaths around the measuring electrode. For the flame quenching case, by assuming that the sheath thickness is comparable with the thermal boundary layer thickness, probe current can be related to flame quenching distance. The theoretical assumptions made to obtain the analytical formulation of probe current were experimentally proved by using direct visualization and high-frequency PIV. The direct visualization method was also used to validate the results of flame quenching distance values obtained with electrical probe. The electrical probe diagnostics have been verified for both head-on and sidewall flame quenching regimes and for stoichiometric methane/air and propane/air mixtures in a pressure range of 0.05-0.6 MPa. (author)

Karrer, Maxime; Makarov, Maxime [Renault Technocentre, 78288 Guyancourt Cedex (France); Bellenoue, Marc; Labuda, Sergei; Sotton, Julien [Laboratoire de Combustion et de Detonique, CNRS, 86961 Futuroscope Chasseneuil (France)

2010-02-15T23:59:59.000Z

364

High temperature probe  

DOE Patents [OSTI]

A high temperature probe for sampling, for example, smokestack fumes, and is able to withstand temperatures of 3000.degree. F. The probe is constructed so as to prevent leakage via the seal by placing the seal inside the water jacket whereby the seal is not exposed to high temperature, which destroys the seal. The sample inlet of the probe is also provided with cooling fins about the area of the seal to provide additional cooling to prevent the seal from being destroyed. Also, a heated jacket is provided for maintaining the temperature of the gas being tested as it passes through the probe. The probe includes pressure sensing means for determining the flow velocity of an efficient being sampled. In addition, thermocouples are located in various places on the probe to monitor the temperature of the gas passing there through.

Swan, Raymond A. (Fremont, CA)

1994-01-01T23:59:59.000Z

365

Model Studies of Pore Stability and Evolution in Thermal Barrier Coatings (TBCs)  

E-Print Network [OSTI]

N. Katz, “Advanced Ceramics: Thermal Barrier Coatings BeatConductivity of Advanced Ceramic Thermal Barrier CoatingsFatigue Testing of Ceramic Thermal Barrier Coatings,” NASA/

Glaeser, A M

2008-01-01T23:59:59.000Z

366

Development Of 2-Meter Soil Temperature Probes And Results Of...  

Open Energy Info (EERE)

Meter Soil Temperature Probes And Results Of Temperature Survey Conducted At Desert Peak, Nevada, Usa Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference...

367

Fireside corrosion probes--an update  

SciTech Connect (OSTI)

The ability to monitor the corrosion degradation of key metallic components in fossil fuel power plants will become increasingly important for FutureGen and ultra-supercritical power plants. A number of factors (ash deposition, coal composition changes, thermal gradients, and low NOx conditions, among others) which occur in the high temperature sections of energy production facilities, will contribute to fireside corrosion. Several years of research have shown that high temperature corrosion rate probes need to be better understood before corrosion rate can be used as a process variable by power plant operators. Our recent research has shown that electrochemical corrosion probes typically measure lower corrosion rates than those measured by standard mass loss techniques. While still useful for monitoring changes in corrosion rates, absolute probe corrosion rates will need a calibration factor to be useful. Continuing research is targeted to help resolve these issues.

Covino, B.S., Jr.; Bullard, S.J.; Holcomb, G.R.; Ziomek-Moroz, M.; Matthes, S.A.

2007-01-01T23:59:59.000Z

368

Thermalization in External Magnetic Field  

E-Print Network [OSTI]

In the AdS/CFT framework meson thermalization in the presence of a constant external magnetic field in a strongly coupled gauge theory has been studied. In the gravitational description the thermalization of mesons corresponds to the horizon formation on the flavour D7-brane which is embedded in the AdS_5 x S^5 background in the probe limit. The apparent horizon forms due to the time-dependent change in the baryon number chemical potential, the injection of baryons in the gauge theory. We will numerically show that the thermalization happens even faster in the presence of the magnetic field on the probe brane. We observe that this reduction in the thermalization time sustains up to a specific value of the magnetic field.

Ali-Akbari, Mohammad

2012-01-01T23:59:59.000Z

369

Progress and Status on Through-Plane Resistance and Conductivity...  

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

2 GDE 2 GDE 1 Overlap Area Bottom Top Top View U.S. Patent No. 7,652,479 Side View 14 Offset electrode geometry for 4-probe conductivity measurement of thin film electrolytes V...

370

Thermal Energy Storage in Metal Foams filled with Paraffin Wax.  

E-Print Network [OSTI]

??Phase change materials (PCM) such as paraffin wax are known to exhibit slow thermal response due to their relatively low thermal conductivity. In this study,… (more)

Vadwala, Pathik

2012-01-01T23:59:59.000Z

371

JOURNAL DE PHYSIQUE Colloque C6, suppldment au no 8, Tome 39, aolit 1978, page C6-344 LAYERING AND THERMAL CONDUCTIVITY OF 4 ~ eFILMS ON UNIFORM GRAPHITE'  

E-Print Network [OSTI]

-Halsey-Hill pressure isotherm fit /5/ which assumes liquid-like film Fin. 1 : Heat capacity of 27.47 STPcc He film combined heat capacity, vapor pressure and thermal resistance measurements to cha- racterize layering and onsets of superfluidity on a highly uniform graphite substrate, UCAR-ZYX. Strong desorption heat capacity

Paris-Sud XI, Université de

372

High-Throughput Mode Liquid Microjunction Surface Sampling Probe  

SciTech Connect (OSTI)

A simple and automated spot sampling operation mode for a liquid microjunction surface sampling probe/electrospray ionization mass spectrometry (LMJ-SSP/ESI-MS) system is reported. Prior manual and automated spot sampling methods with this probe relied on a careful, relatively slow alignment of the probe and surface distance (<20 m spacing) to form the probe-to-surface liquid microjunction critical to successful surface sampling. Moreover, sampling multiple spots required retraction of the surface from the probe and a repeat of this careful probe-to-surface distance alignment at the next sampling position. With the method described here, the probe was not positioned as close to the surface, the exact probeto-surface positioning was found to be less critical (spanning distances from about 100-300 m), and this distance was not altered during the sampling of an entire array of sample spots. With the probe positioned within the appropriate distance from the surface, the liquid microjunction was formed by letting the liquid from the sampling end of the probe extend out from the probe to the surface. This was accomplished by reducing the selfaspiration liquid flow rate of the probe to a value less than the volume flow rate pumped into the probe. When the self-aspiration rate of the probe was subsequently increased, analytes on the surface that dissolved at the liquid microjunction were aspirated back into the probe with the liquid that created the liquid microjunction and electrosprayed. Presented here are the basics of this new sampling mode, as well as data that illustrate the potential analytical capabilities of the device to conduct highthroughput quantitative analysis.

Van Berkel, Gary J [ORNL; Kertesz, Vilmos [ORNL; King, Richard C. [PharmaCadence

2009-01-01T23:59:59.000Z

373

E-Print Network 3.0 - ac conductivity studies Sample Search Results  

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

Conductivity, Molecular... Dynamics Simulation, Thermal Conductance ABSTRACT Several heat transfer problems related to single... function between carbon and carbon within a...

374

Carbon nanotube based electromechanical probes  

E-Print Network [OSTI]

Electromechanical probing applications continuously require smaller pitches, faster manufacturing and lower electrical resistance. Conventional techniques, such as MEMS based cantilever probes have their shortcomings in ...

Yaglioglu, Onnik, 1976-

2007-01-01T23:59:59.000Z

375

Systems analysis of thermal storage  

SciTech Connect (OSTI)

During FY80 analyses were conducted on thermal storage concepts for solar thermal applications. These studies include both estimates of the obtainable costs of thermal storage concepts and their worth to a user (i.e., value). Based on obtainable costs and performance, promising thermal storage concepts are being identified. A preliminary screening was completed in FY80 and a more in-depth study was initiated. Value studies are being conducted to establish cost goals. A ranking of storage concepts based on value in solar thermal electric plants was conducted for both diurnal and long duration applications. Ground mounted thermal storage concepts for a parabolic dish/Stirling systtem are also being evaluated.

Copeland, R. J.

1980-08-01T23:59:59.000Z

376

Foldable polymers as probes  

DOE Patents [OSTI]

Disclosed herein are novel probes, which can be used to detect and identify target molecules of interest in a sample. The disclosed probes can be used to monitor conformational changes induced by molecular recognition events in addition to providing signaling the presence and/or identity of a target molecule. Methods, including solid phase synthesis techniques, for making probe molecules that exhibit changes in their optical properties upon target molecule binding are described in the disclosure. Also disclosed herein are novel chromophore moieties, which have tailored fluorescent emission spectra.

Li, Alexander D. Q. (Pullman, WA); Wang, Wei (Pullman, WA)

2009-07-07T23:59:59.000Z

377

Chemical sensing flow probe  

SciTech Connect (OSTI)

A new chemical probe determines the properties of an analyte using the light absorption of the products of a reagent/analyte reaction. The probe places a small reaction volume in contact with a large analyte volume. Analyte diffuses into the reaction volume. Reagent is selectively supplied to the reaction volume. The light absorption of the reaction in the reaction volume indicates properties of the original analyte. The probe is suitable for repeated use in remote or hostile environments. It does not require physical sampling of the analyte or result in significant regent contamination of the analyte reservoir. 7 figs.

Laguna, G.R.; Peter, F.J.; Butler, M.A.

1999-02-16T23:59:59.000Z

378

Probing metal solidification nondestructively  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home DesignPresentationsSRS Responds toPrivacyProbingProbingProbing

379

Chemical sensing flow probe  

DOE Patents [OSTI]

A new chemical probe determines the properties of an analyte using the light absorption of the products of a reagent/analyte reaction. The probe places a small reaction volume in contact with a large analyte volume. Analyte diffuses into the reaction volume. Reagent is selectively supplied to the reaction volume. The light absorption of the reaction in the reaction volume indicates properties of the original analyte. The probe is suitable for repeated use in remote or hostile environments. It does not require physical sampling of the analyte or result in significant regent contamination of the analyte reservoir.

Laguna, George R. (Albuquerque, NM); Peter, Frank J. (Albuquerque, NM); Butler, Michael A. (Albuquerque, NM)

1999-01-01T23:59:59.000Z

380

Systems analysis of thermal storage  

SciTech Connect (OSTI)

During FY 1981, analyses were conducted on thermal storage concepts for solar thermal applications. These studies include estimates of both the obtainable costs of thermal storage concepts and their worth to a user (i.e., value). Based on obtainable costs and performance, an in-depth study evaluated thermal storage concepts for water/steam, organic fluid, and gas/Brayton solar thermal receivers. Promising and nonpromising concepts were identified. A study to evaluate thermal storage concepts for a liquid metal receiver was initiated. The value of thermal storage in a solar thermal industrial process heat application was analyzed. Several advanced concepts are being studied, including ground-mounted thermal storage for parabolic dishes with Stirling engines.

Copeland, R.J.

1981-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Development progress of the Materials Analysis and Particle Probe  

SciTech Connect (OSTI)

The Materials Analysis and Particle Probe (MAPP) is a compact in vacuo surface science diagnostic, designed to provide in situ surface characterization of plasma facing components in a tokamak environment. MAPP has been implemented for operation on the Lithium Tokamak Experiment at Princeton Plasma Physics Laboratory (PPPL), where all control and analysis systems are currently under development for full remote operation. Control systems include vacuum management, instrument power, and translational/rotational probe drive. Analysis systems include onboard Langmuir probes and all components required for x-ray photoelectron spectroscopy, low-energy ion scattering spectroscopy, direct recoil spectroscopy, and thermal desorption spectroscopy surface analysis techniques.

Lucia, M., E-mail: mlucia@pppl.gov; Kaita, R.; Majeski, R.; Boyle, D. P.; Schmitt, J. C.; Onge, D. A. St. [Princeton Plasma Physics Laboratory (PPPL), Princeton, New Jersey 08543 (United States); Bedoya, F.; Allain, J. P. [Department of Nuclear, Plasma, and Radiological Engineering, University of Illinois at Urbana-Champaign (UIUC), Urbana, Illinois 61801 (United States)

2014-11-15T23:59:59.000Z

382

Europium-doped Pyrochlores for Use as Thermographic Phosphors in Thermal Barrier Coatings  

E-Print Network [OSTI]

temperatures and better efficiency · Two primary characteristics for coating: low thermal conductivity and high conductivities and high thermal expansion coefficients making them attractive as materials in thermal barrier · Selected compounds have low thermal conductivity, high melting points, and adequate thermal expansion

Walker, D. Greg

383

Simultaneous increase in electrical conductivity and Seebeck coefficient in highly Boron-doped nanocrystalline Si  

E-Print Network [OSTI]

, and is the thermal conductivity. Although traditionally ZT remained low (below one for most materials), over the last thermoelectric materials due to such a significant reduction in their thermal conductivity compared to bulk Si in their thermal conductivity [1, 2]. Silicon nanostructures have also been recently proposed as efficient

384

Thermal ignition combustion system  

DOE Patents [OSTI]

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.

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

1988-04-19T23:59:59.000Z

385

Thermal Transport in Nanoporous Materials for Energy Applications  

E-Print Network [OSTI]

Theory of thermal conduction in thin ceramic ?lms”,Thermal resistance of grain boundaries in alumina ceramicsThermal conduc- tivity of highly porous zirconia”, Journal of the European Ceramic

Fang, Jin

2012-01-01T23:59:59.000Z

386

Influence of embedded-carbon nanotubes on the thermal properties of copper matrix nanocomposites processed  

E-Print Network [OSTI]

-level mix- ing, exhibits CNTs homogeneously dispersed in the Cu matrix. Measured thermal conductivity: Metal matrix composites; Nanocomposite; Carbon and graphite; Thermal conductivity Carbon nanotubes (CNTs management applications, due to their extraordinarily low coefficient of thermal expan- sion (CTE) [1

Hong, Soon Hyung

387

The thermal Casimir effect for rough metallic plates  

E-Print Network [OSTI]

We propose a new theory of thermal Casimir effect, holding for the experimentally important case of metallic surfaces with a roughness having a spatial scale smaller than the skin depth. The theory is based on a simple phenomenological model for a rough conductor, that explicitly takes account of the fact that ohmic conduction in the immediate vicinity of the surface of a conductor is much impeded by surface roughness, if the amplitude of roughness is smaller than the skin depth. As a result of the new model, we find that surface roughness strongly influences the magnitude of the thermal correction to the Casimir force, independently of the plates separation. Our model, while consistent with recent accurate measurements of the Casimir force in the submicron range, leads to a new prediction for the not yet observed thermal correction to the Casimir force at large plates separation. Besides the thermal Casimir problem, our model is relevant for the correct theoretical interpretation of current experiments probing other proximity effects between conductors, like radiative heat transfer and quantum friction.

G. Bimonte

2007-11-04T23:59:59.000Z

388

Modeling thermal/chemical/mechanical response of energetic materials  

SciTech Connect (OSTI)

An overview of modeling at Sandia National Laboratories is presented which describes coupled thermal, chemical and mechanical response of energetic materials. This modeling addresses cookoff scenarios for safety assessment studies in systems containing energetic materials. Foundation work is discussed which establishes a method for incorporating chemistry and mechanics into multidimensional analysis. Finite element analysis offers the capabilities to simultaneously resolve reactive heat transfer and structural mechanics in complex geometries. Nonlinear conduction heat transfer, with multiple step finite-rate chemistry, is resolved using a thermal finite element code. Rate equations are solved element-by-element using a modified matrix-free stiff solver This finite element software was developed for the simulation of systems requiring large numbers of finite elements. An iterative implicit scheme, based on the conjugate gradient method, is used and a hemi-cube algorithm is employed for the determination of view factors in surface-to-surface radiation transfer The critical link between the reactive heat transfer and mechanics is the introduction of an appropriate constitutive material model providing a stress-strain relationship for quasi-static mechanics analysis. This model is formally derived from bubble nucleation theory, and parameter variations of critical model parameters indicate that a small degree of decomposition leads to significant mechanical response. Coupled thermal/chemical/mechanical analysis is presented which simulates experiments designed to probe cookoff thermal-mechanical response of energetic materials.

Baer, M.R.; Hobbs, M.L.; Gross, R.J. [and others

1995-07-01T23:59:59.000Z

389

Student Affairs STUDENT CONDUCT  

E-Print Network [OSTI]

Student Affairs CODE OF STUDENT CONDUCT 2014-15 #12;Contents Letter from the Dean of Students ....................................................................ii Binghamton University's Code of Student Conduct Preamble...................... 1 Section I: Rules of Student Conduct.............................................................. 1 Section II: Definitions

Suzuki, Masatsugu

390

Vapor deposited samarium zirconate thermal barrier coatings Hengbei Zhao a,  

E-Print Network [OSTI]

Thermal barrier coatings The rare earth zirconates (M2Zr2O7, M=LaGd) have a low intrinsic thermal conductivity and high temperature phase stability making them attractive candidates for thermal barrier coating conditions and the coating composition, structure, texture, pore morphology, and thermal conductivity

Wadley, Haydn

391

Spatially resolved thermal desorption/ionization coupled with mass spectrometry  

DOE Patents [OSTI]

A system and method for sub-micron analysis of a chemical composition of a specimen are described. The method includes providing a specimen for evaluation and a thermal desorption probe, thermally desorbing an analyte from a target site of said specimen using the thermally active tip to form a gaseous analyte, ionizing the gaseous analyte to form an ionized analyte, and analyzing a chemical composition of the ionized analyte. The thermally desorbing step can include heating said thermally active tip to above 200.degree. C., and positioning the target site and the thermally active tip such that the heating step forms the gaseous analyte. The thermal desorption probe can include a thermally active tip extending from a cantilever body and an apex of the thermally active tip can have a radius of 250 nm or less.

Jesse, Stephen; Van Berkel, Gary J; Ovchinnikova, Olga S

2013-02-26T23:59:59.000Z

392

Convective heat flow probe  

DOE Patents [OSTI]

A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packet-type seals are provided along the probe above and below the heater pads.

Dunn, J.C.; Hardee, H.C.; Striker, R.P.

1984-01-09T23:59:59.000Z

393

Thermal and Electrical Transport in Oxide Heterostructures  

E-Print Network [OSTI]

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

Ravichandran, Jayakanth

2011-01-01T23:59:59.000Z

394

Advanced thermal imaging of composites  

SciTech Connect (OSTI)

Composite materials were studied by Scanning Thermal Conductivity Microscope (STCM) and high speed thermography. The STCM is a qualitative technique which is used to study thermal conductivity variations on a sub-micrometer scale. High speed thermography is a quantitative technique for measuring thermal diffusivity with a variable spatial resolution from centimeters down to less than 25 gm. A relative thermal conductivity contrast map was obtained from a SiC/Si3N4 continuous fiber ceramic composite using the STCM. Temperature changes of a carbon/carbon composite after a heat pulse were captured by an IR camera to generate a thermal diffusivity map of the specimen. Line profiles of the temperature distribution showed significant variations as a result of fiber orientation.

Wang, H.; Dinwiddie, R.B.

1996-06-01T23:59:59.000Z

395

Multispectral imaging probe  

DOE Patents [OSTI]

A multispectral imaging probe delivers a range of wavelengths of excitation light to a target and collects a range of expressed light wavelengths. The multispectral imaging probe is adapted for mobile use and use in confined spaces, and is sealed against the effects of hostile environments. The multispectral imaging probe comprises a housing that defines a sealed volume that is substantially sealed from the surrounding environment. A beam splitting device mounts within the sealed volume. Excitation light is directed to the beam splitting device, which directs the excitation light to a target. Expressed light from the target reaches the beam splitting device along a path coaxial with the path traveled by the excitation light from the beam splitting device to the target. The beam splitting device directs expressed light to a collection subsystem for delivery to a detector.

Sandison, David R. (Moriarty, NM); Platzbecker, Mark R. (Albuquerque, NM); Descour, Michael R. (Tucson, AZ); Armour, David L. (Albuquerque, NM); Craig, Marcus J. (Albuquerque, NM); Richards-Kortum, Rebecca (Austin, TX)

1999-01-01T23:59:59.000Z

396

Multispectral imaging probe  

DOE Patents [OSTI]

A multispectral imaging probe delivers a range of wavelengths of excitation light to a target and collects a range of expressed light wavelengths. The multispectral imaging probe is adapted for mobile use and use in confined spaces, and is sealed against the effects of hostile environments. The multispectral imaging probe comprises a housing that defines a sealed volume that is substantially sealed from the surrounding environment. A beam splitting device mounts within the sealed volume. Excitation light is directed to the beam splitting device, which directs the excitation light to a target. Expressed light from the target reaches the beam splitting device along a path coaxial with the path traveled by the excitation light from the beam splitting device to the target. The beam splitting device directs expressed light to a collection subsystem for delivery to a detector. 8 figs.

Sandison, D.R.; Platzbecker, M.R.; Descour, M.R.; Armour, D.L.; Craig, M.J.; Richards-Kortum, R.

1999-07-27T23:59:59.000Z

397

Probing Mercury's Partnering Preferences  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsrucLas ConchasPassive Solar Home DesignPresentationsSRS Responds toPrivacy ActProbingProbing

398

Probing metal solidification nondestructively  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 - SeptemberMicroneedles for4-16 FORPoints ofProbing Strain-Induced ChangesProbing

399

Atom Probe Tomography | EMSL  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc DocumentationP-Series to someone byDear Friend,Arthur J. NozikAtom Probe Tomography Atom Probe

400

Thermal management of nanoelectronics  

E-Print Network [OSTI]

-state thermoelectric on- spot cooling, requiring efficient thermoelectric materials that can be integrated with the IC are further complicated by the fact that the material's ability to conduct heat deteriorates when at the packaging level but also at the nanoscale materials and device levels. THERMAL CHALLENGES AT NANOSCALE One

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Thermal desorption for passive dosimeter  

E-Print Network [OSTI]

~ ~ ~ \\ ~ ~ ~ ~ Flare Tubes for Thermal Desorber . . . . . ~. . . . . . ~ ~ . 27 4. 5 ~ Thermal Desorber Manufactured by Century System Sample Flow from Thermal Desorber to Gas Chromatograph 29 6. Direct Injection Port for Therma1 Desorber . . . . . $2... the gas badges and. providing additional guidance in conducting the study. DEDICATZOil This thesis is cedicated to my parents and my wife, Unice, for their support during the last t', o years AHSTHACT ACKI;ODL DG~~. 'ITS D' DICATICI'. LIST OF TABL...

Liu, Wen-Chen

1981-01-01T23:59:59.000Z

402

CONDUCT OF OPERATIONS (CO)  

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

CONDUCT OF OPERATIONS (CO) OBJECTIVE TA-55 SST Facility NNSA ORR Implementation Plan 1 1 CO.1 The formality and discipline of operations is adequate to conduct work safely and...

403

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

E-Print Network [OSTI]

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, ...

Henry, Asegun

404

Glass-Like Heat Conduction in Crystalline Semiconductors  

SciTech Connect (OSTI)

The thermal conductivity and structural properties of polycrystalline and single crystal semiconductor type-1 germanium clathrates are reported. Germanium clathrates exhibit thermal conductivities that are typical of amorphous materials. This behavior occurs in spite of their well-defined crystalline structure. The authors employ temperature dependent neutron diffraction data in investigating the displacements of the caged strontium atoms in Sr{sub 8}Ga{sub 16}Ge{sub 30} and their interaction with the polyhedral cages that entrap them. Their aim is to investigate the correlation between the structural properties and the low, glass-like thermal conductivity observed in this compound.

Nolas, G.S.; Cohn, J.L.; Chakoumakos, B.C.; Slack, G.A.

1999-06-13T23:59:59.000Z

405

Dark Energy Probes of Dark Energy  

E-Print Network [OSTI]

19/12/2013 1 Dark Energy Probes of Dark Energy Probes Dark Energy Supernovae Ia probing luminosity (Betti numbers) #12;19/12/2013 2 Dark Energy Probes: Comparison Method Strengths Weaknesses Systematics

Weijgaert, Rien van de

406

Sonar probing of concrete  

E-Print Network [OSTI]

ABSTRACT Sonar Probing of Concrete (May 1988) John H. Mims, B. A. , Carleton College Chairman of Advisory Committee: Dr. Robert R, Unterberger Two systems were used for acoustical tests at concrete dams. The first system used a pair of donated... reflections from several concrete-air interfaces at the Norfork Dam, Arkansas. A reflection between two walls in the dam's operating gallery which were 6. 73 m apart was recorded at 3. 4 ms (peak value). After subtracting the appropriate delays, this value...

Mims, John Hornsby

1988-01-01T23:59:59.000Z

407

Electrically conductive composite material  

DOE Patents [OSTI]

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.

Clough, R.L.; Sylwester, A.P.

1989-05-23T23:59:59.000Z

408

Electrically conductive composite material  

DOE Patents [OSTI]

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.

Clough, R.L.; Sylwester, A.P.

1988-06-20T23:59:59.000Z

409

Electrically conductive composite material  

DOE Patents [OSTI]

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.

Clough, Roger L. (Albuquerque, NM); Sylwester, Alan P. (Albuquerque, NM)

1989-01-01T23:59:59.000Z

410

Heat conduction of single-walled carbon nanotube isotope-superlattice structures: A molecular dynamics study  

E-Print Network [OSTI]

-folding effect to thermal boundary resistance of lattice interface. The crossover mechanism is explained-dimensional materials. In our previous molecular dynamics study, isotope-effects on the thermal conduction were of heat conduction of SWNTs subjected to nanoscale intrinsic thermal resistances. Here, in order to reduce

Maruyama, Shigeo

411

Thermal transport in boron nitride nanotorus—towards a nanoscopic thermal shield  

SciTech Connect (OSTI)

Nanotori, or nanorings, are topological variants of nanotubes and are conceived to have different properties from their tubular form. In this study, the toroidal arrangement of boron nitride is introduced. Using classical molecular dynamics simulations, the thermal behaviour (thermal conductivity and thermal stability) of the boron nitride nanotorus and its relationship with the structural characteristics are investigated. Its circumferential thermal rectification strength displays a linear dependence on the bending coefficient of the nanostructure. Surface kinks are relatively inconsequential on its circumferential mode of conduction, as compared to its axial sense. The circumferential conductivity in the diffusive regime is calculated to be approximately 10?W/m K, while the axial conductivity is more than tenfold of this value. All nanotori with different toroidal characters show excellent thermal stability at extremely high temperatures approaching 3400?K. With consideration to its favourable properties, a thermal shield made up of a parallel row of nanotori is proposed as a nanoscale thermal insulation device.

Loh, G. C., E-mail: jgloh@mtu.edu [Institute of High Performance Computing, 1 Fusionopolis Way, 16-16 Connexis, Singapore 138632 (Singapore); Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States); Baillargeat, D. [CNRS-International-NTU-Thales Research Alliance (CINTRA), 50 Nanyang Drive, Singapore 637553 (Singapore)

2013-11-14T23:59:59.000Z

412

Effect of phantom dark energy on the holographic thermalization  

E-Print Network [OSTI]

Gravitational collapse of a shell of charged dust surrounded by the phantom dark energy is probed by the minimal area surface, which is dual to probe the thermalization in the boundary quantum field by expectation values of Wilson loop in the framework of the AdS/CFT correspondence. We investigated mainly the effect of the phantom dark energy parameter and chemical potential on the thermalization. The result shows that the smaller the phantom dark energy parameter is, the easier the plasma thermalizes as the chemical potential is fixed, and the larger the chemical potential is, the harder the plasma thermalizes as the dark energy parameter is fixed. We get the fitting function of the thermalization curve and with it, the thermalization velocity and thermalization acceleration are discussed.

Zeng, Xiao-Xiong; Li, Li-Fang

2015-01-01T23:59:59.000Z

413

Effect of phantom dark energy on the holographic thermalization  

E-Print Network [OSTI]

Gravitational collapse of a shell of charged dust surrounded by the phantom dark energy is probed by the minimal area surface, which is dual to probe the thermalization in the boundary quantum field by expectation values of Wilson loop in the framework of the AdS/CFT correspondence. We investigated mainly the effect of the phantom dark energy parameter and chemical potential on the thermalization. The result shows that the smaller the phantom dark energy parameter is, the easier the plasma thermalizes as the chemical potential is fixed, and the larger the chemical potential is, the harder the plasma thermalizes as the dark energy parameter is fixed. We get the fitting function of the thermalization curve and with it, the thermalization velocity and thermalization acceleration are discussed.

Xiao-Xiong Zeng; Xin-Yun Hu; Li-Fang Li

2015-03-16T23:59:59.000Z

414

E-Print Network 3.0 - anisotropic thermal expansion Sample Search...  

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

Thermal Conductivity Summary: sensors, actuators, logic circuits, and organic optoelectronic devices. The high thermal expansion... and the dielectric constant 9 of these...

415

E-Print Network 3.0 - applied thermal cutting Sample Search Results  

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

applied... ON THE EFFECTIVE THERMAL CONDUCTIVITY AND THERMAL CONTACT RESISTANCE IN PEM FUEL CELL GAS DIFFUSION LAYERS Ehsan... of this process requires determination of the...

416

E-Print Network 3.0 - augmented thermal management Sample Search...  

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

devices are too... the thermal conductivity. The promise of improved thermoelectric materials and problems of thermal management... . In most cur- rent and envisioned...

417

Very high energy probes of the quark-gluon plasma  

SciTech Connect (OSTI)

Among the penetrating probes of nuclear matter the most frequently discussed have been those which involve the detection of photons or leptons with m/sub T/ approx. = P/sub T/ < 3 GeV. This is the expected range of emission from a hot, thermalized plasma of quarks and gluons. The suggestion has been made that in very high energy collisions of nuclei the properties of high P/sub T/ jets may also reflect the characteristics of the nuclear medium through which the parent partons have propagated just after the collision. In this note we expand on the possible uses of such a probe.

Ludlam, T.; Paige, F.; Madansky, L.

1984-01-01T23:59:59.000Z

418

Acoustic phonon engineering of thermal properties of silicon-based nanostructures  

E-Print Network [OSTI]

with the high electrical conductivity and low thermal conductivity [7]. It has been shown theoretically investigate the influence of the cladding materials on the phonon thermal conductivity in Si-based planar thermal conduction in the Si-based planar heterostructures and rectangular hetero-nanowires. The phonon

419

Flexible high-temperature pH probe  

DOE Patents [OSTI]

A flexible pH probe device is provided for use in hot water and other high temperature environments up to about 590.degree. F. The pH probe includes a flexible, inert tubular probe member, an oxygen anion conducting, solid state electrolyte plug located at the distal end of the tubular member, oxide powder disposed at the distal end of the tubular member; a metal wire extending along the tubular member and having a distal end in contact with the oxide powder so as to form therewith an internal reference electrode; and a compression fitting forming a pressure boundary seal around a portion of the tubular member remote from the distal end thereof. Preferably, the tubular member is made of polytetrafluoroethylene, and the solid state electrolyte plug is made of stabilized zirconia. The flexibility of the probe member enables placement of the electrode into the area of interest, including around corners, into confined areas and the like.

Bielawski, John C. (Scotia, NY); Outwater, John O. (Cambridge, MA); Halbfinger, George P. (Schenectady, NY)

2003-04-22T23:59:59.000Z

420

High conductance surge cable  

DOE Patents [OSTI]

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.

Murray, M.M.; Wilfong, D.H.; Lomax, R.E.

1998-12-08T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

High conductance surge cable  

DOE Patents [OSTI]

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.

Murray, Matthew M. (Espanola, NM); Wilfong, Dennis H. (Brooksville, FL); Lomax, Ralph E. (Santa Fe, NM)

1998-01-01T23:59:59.000Z

422

Thermal and non-thermal energies in solar flares  

E-Print Network [OSTI]

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.

Pascal Saint-Hilaire; Arnold O. Benz

2005-03-03T23:59:59.000Z

423

Electrically conductive cellulose composite  

DOE Patents [OSTI]

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.

Evans, Barbara R.; O'Neill, Hugh M.; Woodward, Jonathan

2010-05-04T23:59:59.000Z

424

Experimental probes of axions  

SciTech Connect (OSTI)

Experimental searches for axions or axion-like particles rely on semiclassical phenomena resulting from the postulated coupling of the axion to two photons. Sensitive probes of the extremely small coupling constant can be made by exploiting familiar, coherent electromagnetic laboratory techniques, including resonant enhancement of transitions using microwave and optical cavities, Bragg scattering, and coherent photon-axion oscillations. The axion beam may either be astrophysical in origin as in the case of dark matter axion searches and solar axion searches, or created in the laboratory from laser interactions with magnetic fields. This note is meant to be a sampling of recent experimental results.

Chou, Aaron S.; /Fermilab

2009-10-01T23:59:59.000Z

425

Electromagnetic Probes in PHENIX  

E-Print Network [OSTI]

Electromagnetic probes are arguably the most universal tools to study the different physics processes in high energy hadron and heavy ion collisions. In this paper we summarize recent measurements of real and virtual direct photons at central rapidity by the PHENIX experiment at RHIC in p+p, d+Au and Au+Au collisions. We also discuss the impact of the results and the constraints they put on theoretical models. At the end we report on the immediate as well as on the mid-term future of photon measurements at RHIC.

Gabor David

2006-09-21T23:59:59.000Z

426

Thermal insulated glazing unit  

SciTech Connect (OSTI)

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.

Selkowitz, Stephen E. (Piedmont, CA); Arasteh, Dariush K. (Oakland, CA); Hartmann, John L. (Seattle, WA)

1991-01-01T23:59:59.000Z

427

Thermal insulated glazing unit  

SciTech Connect (OSTI)

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.

Selkowitz, S.E.; Arasteh, D.K.; Hartmann, J.L.

1988-04-05T23:59:59.000Z

428

Thermally actuated thermionic switch  

DOE Patents [OSTI]

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.

Barrus, D.M.; Shires, C.D.

1982-09-30T23:59:59.000Z

429

Probing Multiparton Correlations at CEBAF  

E-Print Network [OSTI]

In this talk, I explore the possibilities of probing the multiparton correlation functions at CEBAF at its current energy and the energies with its future upgrades.

Jianwei Qiu

1998-08-08T23:59:59.000Z

430

Calorimetric measurements of nuclear heating in small probes of plasma-facing materials  

SciTech Connect (OSTI)

Direct measurements of nuclear heating in small probes of materials subjected to D-T neutrons from an accelerator based source were initiated during 1989 under USDOE/JAERI collaborative program. A calorimetric technique was utilized to make these measurements. The probes of plasma facing materials, among others, were kept very close, {approximately}3 to {approximately}7 cm, to the neutron source inside an evacuated vacuum chamber. A typical probe measured 20 mm in diameter by 20 mm in length. Typical source intensity was {approximately}2 x 10{sup 12} n/s. The temperature changes in the probe medium were detected by thermal sensors spatially distributed in the probe. The thermal sensors included bead-thermistors, and platinum RTD`s. The change in resistance of a thermal sensor due to onset of nuclear heating was picked up by an automated data acquisition and control system that included a highly sensitive digital voltmeter that had a resolution of 100 nV in voltage range of 300 mV or less. Usually, an individual probe was subjected to spaced neutron pulses of time duration 3 m to 10 m. Two consecutive source neutron pulses were separated by a cooling interval of almost the same duration as that of a source pulse. This approach made it possible to clearly distinguish between the heating and drift phases of the probe medium, on one hand, and to ascertain and verify the reproducibility of measured heating rates from one neutron pulse to another, on the other hand.

Kumar, A.; Abdou, M.A.; Youssef, M.Z. [Univ. of California, Los Angeles, CA (United States)] [and others

1994-12-31T23:59:59.000Z

431

24-26 September 2008, Rome, Italy Thermal Design of  

E-Print Network [OSTI]

conductivity of most materials used to electrically insulate the devices enhances the thermal issues that could to estimate the overall thermal resistance by considering a combination of individual thermal resistances of layout parameters upon the thermal resistance of such devices. This contribution is aimed at supplying

Technische Universiteit Delft

432

THERMAL PROPERTIES OF SINGLE-WALLED CARBON NANOTUBES Shigeo MARUYAMA  

E-Print Network [OSTI]

, optical and mechanical properties, thermal properties of SWNTs are quite unique with the high thermal and thermal conductance between a nanotube and various materials are reviewed. The experimental approach, and thermal boundary resistance in a junction of nanotubes are reviewed. Then, the heat transfer from an SWNT

Maruyama, Shigeo

433

Probing the Geometry and Interconnectivity of Pores in Organic Aerogels Using Hyperpolarized 129Xe NMR Spectroscopy  

SciTech Connect (OSTI)

Aerogels represent a class of novel open-pore materials with high surface area and nanometer pore sizes. They exhibit extremely low mass densities, low thermal conductivity, good acoustic insulation, and low dielectric constants. These materials have potential applications in catalysis, advanced separation techniques, energy storage, environmental remediation, and as insulating materials. Organic aerogels are stiffer and stronger than silica aerogels and are better insulators with higher thermal resistance. Resorcinol-Formaldehyde (RF) aerogels are typically prepared through the base-catalyzed sol-gel polymerization of resorcinol with formaldehyde in aqueous solution to produce gels, which are then dried in supercritical CO2.1,2 The [resorcinol]/ [catalyst] (R/C) ratio of the starting sol-gel solution has been determined to be the dominant factor that affects the properties of RF aerogels. Since the unique microstructures of aerogels are responsible for their unusual properties, characterizing the detailed porous structures and correlating them with the processing parameters are vital to establish rational design principles for novel organic aerogels with tailored properties. In this communication we report the first use of hyperpolarized (HP) 129Xe NMR to probe the geometry and interconnectivity of pores in RF aerogels and to correlate these with synthetic conditions. Our work demonstrates that HP 129Xe NMR is so far the only method for accurately measuring the free volume-to-surface-area (Vg/S) ratios for soft mesoporous materials without using any geometric models.

Moudrakovski, Igor L.; Wang, Li Q.; Baumann, T.; Satcher, J. H.; Exarhos, Gregory J.; Ratcliffe, C. I.; Ripmeester, J. A.

2004-04-28T23:59:59.000Z

434

Thermal to electricity conversion using thermal magnetic properties  

DOE Patents [OSTI]

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.

West, Phillip B [Idaho Falls, ID; Svoboda, John [Idaho Falls, ID

2010-04-27T23:59:59.000Z

435

Heat transfer probe  

DOE Patents [OSTI]

Apparatuses, systems, methods, and computer code for, among other things, monitoring the health of samples such as the brain while providing local cooling or heating. A representative device is a heat transfer probe, which includes an inner channel, a tip, a concentric outer channel, a first temperature sensor, and a second temperature sensor. The inner channel is configured to transport working fluid from an inner inlet to an inner outlet. The tip is configured to receive at least a portion of the working fluid from the inner outlet. The concentric outer channel is configured to transport the working fluid from the inner outlet to an outer outlet. The first temperature sensor is coupled to the tip, and the second temperature sensor spaced apart from the first temperature sensor.

Frank, Jeffrey I.; Rosengart, Axel J.; Kasza, Ken; Yu, Wenhua; Chien, Tai-Hsin; Franklin, Jeff

2006-10-10T23:59:59.000Z

436

Thermalization of Strongly Coupled Field Theories  

SciTech Connect (OSTI)

Using the holographic mapping to a gravity dual, we calculate 2-point functions, Wilson loops, and entanglement entropy in strongly coupled field theories in d=2, 3, and 4 to probe the scale dependence of thermalization following a sudden injection of energy. For homogeneous initial conditions, the entanglement entropy thermalizes slowest and sets a time scale for equilibration that saturates a causality bound. The growth rate of entanglement entropy density is nearly volume-independent for small volumes but slows for larger volumes. In this setting, the UV thermalizes first.

Balasubramanian, V. [David Rittenhouse Laboratory, University of Pennsylvania, Philadelphia, Pennsylvania 19104 (United States); Bernamonti, A.; Copland, N.; Craps, B.; Staessens, W. [Theoretische Natuurkunde, Vrije Universiteit Brussel, and International Solvay Institutes, B-1050 Brussels (Belgium); Boer, J. de [Institute for Theoretical Physics, University of Amsterdam, 1090 GL Amsterdam (Netherlands); Keski-Vakkuri, E. [Helsinki Institute of Physics and Department of Physics, FIN-00014 University of Helsinki (Finland); Mueller, B. [Department of Physics and CTMS, Duke University, Durham, North Carolina 27708 (United States); Schaefer, A. [Institut fuer Theoretische Physik, Universitaet Regensburg, D-93040 Regensburg (Germany); Shigemori, M. [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya 464-8602 (Japan)

2011-05-13T23:59:59.000Z

437

Conduct of Operations  

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

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

2010-06-29T23:59:59.000Z

438

Electrically conductive material  

DOE Patents [OSTI]

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.

Singh, Jitendra P. (Bollingbrook, IL); Bosak, Andrea L. (Burnam, IL); McPheeters, Charles C. (Woodridge, IL); Dees, Dennis W. (Woodridge, IL)

1993-01-01T23:59:59.000Z

439

Electrically conductive material  

DOE Patents [OSTI]

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.

Singh, J.P.; Bosak, A.L.; McPheeters, C.C.; Dees, D.W.

1993-09-07T23:59:59.000Z

440

E-Print Network 3.0 - anomalous ionic conductivity Sample Search...  

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

Science 25 ORNL 2010-G00986jcn UT-B ID 200902213 Summary: . Advantages Superior thermal stability over other protic ionic liquids Proton conducting mechanism does......

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

THERMAL CONDUCTIVITY OF AQUEOUS NaCl SOLUTIONS  

Office of Scientific and Technical Information (OSTI)

aqueous electrolyte solutions are required in the development and uti1 ization of geothermal energy, petroleum recovery, desalination of sea water, and other energy systems...

442

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...

443

Molecular dynamics simulation of thermal conductivity of nanocrystalline composite films  

E-Print Network [OSTI]

October 2008 Available online 30 December 2008 a b s t r a c t The efficiency of a thermoelectric material that result in significant improvements in thermoelectric performance [1]. In particular, these materials show material, then the thermoelectric performance will increase by a factor of 2 over that of the homogeneous

Walker, D. Greg

444

Measurement and modeling thermal conductivity of baked products  

E-Print Network [OSTI]

for serving on my advisory committee and lending their comments and criticisms. I would like to thank El Consejo Vacional de Ciencia. y Tecnologia de Mex- ico, CONACYT, for the financial support that made this tremendous opportunity possible. Finally, I... want to thank El Centro de Investigacion y Desarrollo, A. C. , CIAD, A. C. , Sonora. , Mexico, especially Dr. Carlos Pena, for his encouragement and support to reach this goal. DEDICATION I dedicate this to my wonderful family: my parents, brothers...

Islas Rubio, Alma Rosa

1990-01-01T23:59:59.000Z

445

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

446

Thermal conductivity and specific heat of sorghum grain  

E-Print Network [OSTI]

Formation of Test Canister Ice Jacket ~ Sealing Test Canister in Calorimeter. . 43 44 Testing of Samples. Initial Calorimeter Observations. 49 Insertion of Grain Samples into Calorimeter. . . . 50 Final Test Observations Processing of Data. 54... to Contain the Grain Sample 38 for the Determination of Specific Heat 39 12. Top View of Calorimeter. 40 13. Galvanized Iron Cylinder Used to Form the Ice Jacket Around the Test Canister 42 VIII Figures 14. Clamping Device Used to Hold Test Canister...

Miller, Clinton Frank

1963-01-01T23:59:59.000Z

447

Measurement of Thermal Diffusivity and Conductivity in Advanced Nanostructured Materials  

E-Print Network [OSTI]

in Magnetic Materials . . . . . . . . . . . . . . . viimportants of understanding materials properties typicallyY.S. Ju, Annual Review of Materials Science, 29, 261 (1999).

Teweldebrhan, Desalegne Bekuretsion

2012-01-01T23:59:59.000Z

448

THERMAL CONDUCTIVITY OF POWDER INSULATIONS FOR CRYOGENIC STORAGE  

E-Print Network [OSTI]

aerogel over the temperature range 10 K to 275 K. hi this research, a guarded parallel plate experimental

Chang, Ho-Myung

449

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:YearRound-UpHeatMulti-Dimensional Subject: Guidance forGeospatialSession) |GettingLEARNINGGive|

450

Continuous Processing of High Thermal Conductivity Fibers and Sheets  

Office of Environmental Management (EM)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "of EnergyEnergy Cooperation |South42.2Consolidated Edison Uranium SolidificationSafetyIndustry | Department

451

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary) "ofEarly Career Scientists'Montana. DOCUMENTS AVAILABLEReport 2009 DepartmentPowerDepartment of Energy

452

T I ENHANCING THERMAL CONDUCTIVITY OF FLUIDS WITH NANOPARTICLES*  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security AdministrationcontrollerNanocrystallineForeign Object DamageSystems BiologyvirulenceFade,thehedoJAM

453

Thermal Conductivity of Cubic and Hexagonal Mesoporous Silica Thin Films  

E-Print Network [OSTI]

wire, serving as both a thermometer and a line heat source,as both heater and thermometer, was patterned on (A) (B)Diff Amp B Diff Amp Heater/thermometer on the sample I + V -

Coquil, Thomas; Richman, Eric K.; Hutchinson, Neal J.; Tolbert, S H; Pilon, Laurent

2009-01-01T23:59:59.000Z

454

Development of a graphite probe calorimeter for absolute clinical dosimetry  

SciTech Connect (OSTI)

The aim of this work is to present the numerical design optimization, construction, and experimental proof of concept of a graphite probe calorimeter (GPC) conceived for dose measurement in the clinical environment (U.S. provisional patent 61/652,540). A finite element method (FEM) based numerical heat transfer study was conducted using a commercial software package to explore the feasibility of the GPC and to optimize the shape, dimensions, and materials used in its design. A functioning prototype was constructed inhouse and used to perform dose to water measurements under a 6 MV photon beam at 400 and 1000 MU/min, in a thermally insulated water phantom. Heat loss correction factors were determined using FEM analysis while the radiation field perturbation and the graphite to water absorbed dose conversion factors were calculated using Monte Carlo simulations. The difference in the average measured dose to water for the 400 and 1000 MU/min runs using the TG-51 protocol and the GPC was 0.2% and 1.2%, respectively. Heat loss correction factors ranged from 1.001 to 1.002, while the product of the perturbation and dose conversion factors was calculated to be 1.130. The combined relative uncertainty was estimated to be 1.4%, with the largest contributors being the specific heat capacity of the graphite (type B, 0.8%) and the reproducibility, defined as the standard deviation of the mean measured dose (type A, 0.6%). By establishing the feasibility of using the GPC as a practical clinical absolute photon dosimeter, this work lays the foundation for further device enhancements, including the development of an isothermal mode of operation and an overall miniaturization, making it potentially suitable for use in small and composite radiation fields. It is anticipated that, through the incorporation of isothermal stabilization provided by temperature controllers, a subpercent overall uncertainty will be achieved.

Renaud, James; Seuntjens, Jan; Sarfehnia, Arman [Medical Physics Unit, McGill University, Montreal, Quebec H3G 1A4 (Canada); Marchington, David [Ionizing Radiation Standards, National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada)

2013-02-15T23:59:59.000Z

455

Situ soil sampling probe system with heated transfer line  

DOE Patents [OSTI]

The present invention is directed both to an improved in situ penetrometer probe and to a heated, flexible transfer line. The line and probe may be implemented together in a penetrometer system in which the transfer line is used to connect the probe to a collector/analyzer at the surface. The probe comprises a heater that controls a temperature of a geologic medium surrounding the probe. At least one carrier gas port and vapor collection port are located on an external side wall of the probe. The carrier gas port provides a carrier gas into the geologic medium, and the collection port captures vapors from the geologic medium for analysis. In the transfer line, a flexible collection line that conveys a collected fluid, i.e., vapor, sample to a collector/analyzer. A flexible carrier gas line conveys a carrier gas to facilitate the collection of the sample. A system heating the collection line is also provided. Preferably the collection line is electrically conductive so that an electrical power source can generate a current through it so that the internal resistance generates heat.

Robbat, Jr., Albert (Andover, MA)

2002-01-01T23:59:59.000Z

456

Electrical and Thermal Experimental Characterization and Modeling of Carbon Nanotube/Epoxy Composites  

E-Print Network [OSTI]

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...

Gardea, Frank

2012-10-19T23:59:59.000Z

457

Validation of thermal models for a prototypical MEMS thermal actuator.  

SciTech Connect (OSTI)

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.

Gallis, Michail A.; Torczynski, John Robert; Piekos, Edward Stanley; Serrano, Justin Raymond; Gorby, Allen D.; Phinney, Leslie Mary

2008-09-01T23:59:59.000Z

458

Heat Pipe Embedded AlSiC Plates for High Conductivity - Low CTE Heat Spreaders  

SciTech Connect (OSTI)

Heat pipe embedded aluminum silicon carbide (AlSiC) plates are innovative heat spreaders that provide high thermal conductivity and low coefficient of thermal expansion (CTE). Since heat pipes are two phase devices, they demonstrate effective thermal conductivities ranging between 50,000 and 200,000 W/m-K, depending on the heat pipe length. Installing heat pipes into an AlSiC plate dramatically increases the plate’s effective thermal conductivity. AlSiC plates alone have a thermal conductivity of roughly 200 W/m-K and a CTE ranging from 7-12 ppm/ deg C, similar to that of silicon. An equivalent sized heat pipe embedded AlSiC plate has effective thermal conductivity ranging from 400 to 500 W/m-K and retains the CTE of AlSiC.

Johnson, Matthew (DOE/NNSA Kansas City Plant (United States)); Weyant, J.; Garner, S. (Advanced Cooling Technologies, Inc. (Lancaster, PA (United States)); Occhionero, M. (CPS Technologies Corporation, Norton, MA (United States))

2010-01-07T23:59:59.000Z

459

Long duration ash probe  

DOE Patents [OSTI]

A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during soot blowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon. 8 figs.

Hurley, J.P.; McCollor, D.P.; Selle, S.J.

1994-07-26T23:59:59.000Z

460

Long duration ash probe  

DOE Patents [OSTI]

A long duration ash probe includes a pressure shell connected to a port in a combustor with a sample coupon mounted on a retractable carriage so as to retract the sample coupon within the pressure shell during sootblowing operation of the combustor. A valve mounted at the forward end of the pressure shell is selectively closeable to seal the sample coupon within the shell, and a heating element in the shell is operable to maintain the desired temperature of the sample coupon while retracted within the shell. The carriage is operably mounted on a pair of rails within the shell for longitudinal movement within the shell. A hollow carrier tube connects the hollow cylindrical sample coupon to the carriage, and extends through the carriage and out the rearward end thereof. Air lines are connected to the rearward end of the carrier tube and are operable to permit coolant to pass through the air lines and thence through the carrier tube to the sample coupon so as to cool the sample coupon.

Hurley, John P. (Grand Forks, ND); McCollor, Don P. (Grand Forks, ND); Selle, Stanley J. (Grand Forks, MN)

1994-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Probing Organic Transistors with Infrared Beams  

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

Probing Organic Transistors with Infrared Beams Probing Organic Transistors with Infrared Beams Print Wednesday, 26 July 2006 00:00 Silicon-based transistors are well-understood,...

462

Thermal Characterization of Nanostructures and Advanced Engineered Materials  

E-Print Network [OSTI]

Yan, Y. , Zhang, Q. and Tritt, T.M. , “High ThermoelectricOxford 1963. 3. Tritt, T.M. , “Thermal Conductivity: Theory,

Goyal, Vivek Kumar

2011-01-01T23:59:59.000Z

463

Optic probe for semiconductor characterization  

DOE Patents [OSTI]

Described herein is an optical probe (120) for use in characterizing surface defects in wafers, such as semiconductor wafers. The optical probe (120) detects laser light reflected from the surface (124) of the wafer (106) within various ranges of angles. Characteristics of defects in the surface (124) of the wafer (106) are determined based on the amount of reflected laser light detected in each of the ranges of angles. Additionally, a wafer characterization system (100) is described that includes the described optical probe (120).

Sopori, Bhushan L. (Denver, CO); Hambarian, Artak (Yerevan, AM)

2008-09-02T23:59:59.000Z

464

Differential probes aid flow measurement  

SciTech Connect (OSTI)

Nonconstricting differential pressure flow probes which help solve the problems of clogging, wear, and pressure loss at the Seawater Filtration Facility in Saudi Arabia are described. Treated seawater is pumped into oil-bearing formations for secondary recovery. Figures showing principle of operation for probes, installation schematic and long-term accuracy results (flow probes vs. orifice meters) are presented. The new diamond-shaped design flow sensor offers accurate flow measurement with low permanent pressure loss, which translates into cost savings for the operator.

Mesnard, D.R.

1982-07-01T23:59:59.000Z

465

27-301: Microstructure-Properties: I L8: Thermal Properties  

E-Print Network [OSTI]

ionically and covalently bonded materials exhibit very low conductivities (electrical and thermal of materials to their microstructure. · A practical example is used of optimization of thermal conductivity mechanisms in different types of materials. · Metals exhibit high electrical and thermal conductivity

Rollett, Anthony D.

466

PUBLISHED ONLINE: 9 MAY 2010 | DOI: 10.1038/NMAT2753 Dimensional crossover of thermal transport in  

E-Print Network [OSTI]

on heat conduction in low-dimensional materials and may open up FLG applications in thermal management , is heat conduction in low- dimensional materials. The question of what happens with thermal conductivity unique electronic2,3 and optical properties4 , reveals unusually high thermal conductivity5,6 . The fact

467

Conduct of Operations  

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

This Order defines the requirements for establishing and implementing Conduct of Operations Programs at Department of Energy (DOE), including National Nuclear Security Administration (NNSA), facilities and projects. Cancels DOE O 5480.19. Admin Chg 1, dated 6-25-13, cancels DOE O 422.1. Certified 12-3-14.

2010-06-29T23:59:59.000Z

468

Lithium ion conducting electrolytes  

DOE Patents [OSTI]

A liquid, predominantly lithium-conducting, ionic electrolyte is described having exceptionally high conductivity at temperatures of 100 C or lower, including room temperature, and comprising the lithium salts selected from the group consisting of the thiocyanate, iodide, bromide, chloride, perchlorate, acetate, tetrafluoroborate, perfluoromethane sulfonate, perfluoromethane sulfonamide, tetrahaloaluminate, and heptahaloaluminate salts of lithium, with or without a magnesium-salt selected from the group consisting of the perchlorate and acetate salts of magnesium. Certain of the latter embodiments may also contain molecular additives from the group of acetonitrile (CH{sub 3}CN), succinnonitrile (CH{sub 2}CN){sub 2}, and tetraglyme (CH{sub 3}--O--CH{sub 2}--CH{sub 2}--O--){sub 2} (or like solvents) solvated to a Mg{sup +2} cation to lower the freezing point of the electrolyte below room temperature. Other particularly useful embodiments contain up to about 40, but preferably not more than about 25, mol percent of a long chain polyether polymer dissolved in the lithium salts to provide an elastic or rubbery solid electrolyte of high ambient temperature conductivity and exceptional 100 C conductivity. Another embodiment contains up to about but not more than 10 mol percent of a molecular solvent such as acetone. 2 figs.

Angell, C.A.; Liu, C.

1996-04-09T23:59:59.000Z

469

Lithium ion conducting electrolytes  

DOE Patents [OSTI]

The present invention relates generally to highly conductive alkali-metal ion non-crystalline electrolyte systems, and more particularly to novel and unique molten (liquid), rubbery, and solid electrolyte systems which are especially well suited for use with high current density electrolytic cells such as primary and secondary batteries.

Angell, Charles Austen (Mesa, AZ); Liu, Changle (Midland, MI); Xu, Kang (Montgomery Village, MD); Skotheim, Terje A. (Tucson, AZ)

1999-01-01T23:59:59.000Z

470

Lithium ion conducting electrolytes  

DOE Patents [OSTI]

A liquid, predominantly lithium-conducting, ionic electrolyte having exceptionally high conductivity at temperatures of 100.degree. C. or lower, including room temperature, and comprising the lithium salts selected from the group consisting of the thiocyanate, iodide, bromide, chloride, perchlorate, acetate, tetrafluoroborate, perfluoromethane sulfonate, perfluoromethane sulfonamide, tetrahaloaluminate, and heptahaloaluminate salts of lithium, with or without a magnesium-salt selected from the group consisting of the perchlorate and acetate salts of magnesium. Certain of the latter embodiments may also contain molecular additives from the group of acetonitrile (CH.sub.3 CN) succinnonitrile (CH.sub.2 CN).sub.2, and tetraglyme (CH.sub.3 --O--CH.sub.2 --CH.sub.2 --O--).sub.2 (or like solvents) solvated to a Mg.sup.+2 cation to lower the freezing point of the electrolyte below room temperature. Other particularly useful embodiments contain up to about 40, but preferably not more than about 25, mol percent of a long chain polyether polymer dissolved in the lithium salts to provide an elastic or rubbery solid electrolyte of high ambient temperature conductivity and exceptional 100.degree. C. conductivity. Another embodiment contains up to about but not more than 10 mol percent of a molecular solvent such as acetone.

Angell, C. Austen (Tempe, AZ); Liu, Changle (Tempe, AZ)

1996-01-01T23:59:59.000Z

471

REVIEW ARTIC LE MICROSCALE THERMAL BUBBLE FORMATION  

E-Print Network [OSTI]

8 C a thermal diffusivity, m r s 8 C 2 F excess heat conduction shape factor e variable in the heat, and this article discusses microscale bubble formation by using polysilicon microheaters. Figure 1a shows

Lin, Liwei

472

Switchable stiffness scanning microscope probe  

E-Print Network [OSTI]

Atomic Force Microscopy (AFM) has rapidly gained widespread utilization as an imaging device and micro/nano-manipulator during recent years. This thesis investigates the new concept of a dual stiffness scanning probe with ...

Mueller-Falcke, Clemens T. (Clemens Tobias)

2005-01-01T23:59:59.000Z

473

Thermal Effects of Moisture in Rigid Insulation Board  

E-Print Network [OSTI]

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...

Crow, G. W.

474

Thermal properties of organic and inorganic aerogels  

SciTech Connect (OSTI)

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.

Hrubesh, L.W.; Pekala, R.W. (Chemistry and Material Science Department, Lawrence Livermore National Laboratory, Livermore, California 94551-9900 (United States))

1994-03-01T23:59:59.000Z

475

Ceramic thermal barrier coating for rapid thermal cycling applications  

DOE Patents [OSTI]

A thermal barrier coating for metal articles subjected to rapid thermal cycling includes a metallic bond coat deposited on the metal article, at least one MCrAlY/ceramic layer deposited on the bond coat, and a ceramic top layer deposited on the MCrAlY/ceramic layer. The M in the MCrAlY material is Fe, Ni, Co, or a mixture of Ni and Co. The ceramic in the MCrAlY/ceramic layer is mullite or Al.sub.2 O.sub.3. The ceramic top layer includes a ceramic with a coefficient of thermal expansion less than about 5.4.times.10.sup.-6 .degree.C.sup.-1 and a thermal conductivity between about 1 J sec.sup.-1 m.sup.-1 .degree.C.sup.-1 and about 1.7 J sec.sup.-1 m.sup.-1 .degree.C.sup.-1.

Scharman, Alan J. (Hebron, CT); Yonushonis, Thomas M. (Columbus, IN)

1994-01-01T23:59:59.000Z

476

Electrically conductive alternating copolymers  

DOE Patents [OSTI]

Polymers which are soluble in common organic solvents and are electrically conductive, but which also may be synthesized in such a manner that they become nonconductive. Negative ions from the electrolyte used in the electrochemical synthesis of a polymer are incorporated into the polymer during the synthesis and serve as a dopant. A further electrochemical step may be utilized to cause the polymer to be conductive. The monomer repeat unit is comprised of two rings, a pyrrole molecule joined to a thienyl group, or a furyl group, or a phenyl group. The individual groups of the polymers are arranged in an alternating manner. For example, the backbone arrangement of poly(furylpyrrole) is -furan-pyrrole-furan-pyrrole- furan-pyrrole. An alkyl group or phenyl group may be substituted for either or both of the hydrogen atoms of the pyrrole ring.

Aldissi, M.; Jorgensen, B.S.

1987-08-31T23:59:59.000Z

477

Oxygen ion conducting materials  

DOE Patents [OSTI]

An oxygen ion conducting ceramic oxide that has applications in industry including fuel cells, oxygen pumps, oxygen sensors, and separation membranes. The material is based on the idea that substituting a dopant into the host perovskite lattice of (La,Sr)MnO.sub.3 that prefers a coordination number lower than 6 will induce oxygen ion vacancies to form in the lattice. Because the oxygen ion conductivity of (La,Sr)MnO.sub.3 is low over a very large temperature range, the material exhibits a high overpotential when used. The inclusion of oxygen vacancies into the lattice by doping the material has been found to maintain the desirable properties of (La,Sr)MnO.sub.3, while significantly decreasing the experimentally observed overpotential.

Vaughey, John; Krumpelt, Michael; Wang, Xiaoping; Carter, J. David

2005-07-12T23:59:59.000Z

478

Oxygen ion conducting materials  

DOE Patents [OSTI]

An oxygen ion conducting ceramic oxide that has applications in industry including fuel cells, oxygen pumps, oxygen sensors, and separation membranes. The material is based on the idea that substituting a dopant into the host perovskite lattice of (La,Sr)MnO.sub.3 that prefers a coordination number lower than 6 will induce oxygen ion vacancies to form in the lattice. Because the oxygen ion conductivity of (La,Sr)MnO.sub.3 is low over a very large temperature range, the material exhibits a high overpotential when used. The inclusion of oxygen vacancies into the lattice by doping the material has been found to maintain the desirable properties of (La,Sr)MnO.sub.3, while significantly decreasing the experimentally observed overpotential.

Carter, J. David; Wang, Xiaoping; Vaughey, John; Krumpelt, Michael

2004-11-23T23:59:59.000Z

479

Oxygen ion conducting materials  

DOE Patents [OSTI]

An oxygen ion conducting ceramic oxide that has applications in industry including fuel cells, oxygen pumps, oxygen sensors, and separation membranes. The material is based on the idea that substituting a dopant into the host perovskite lattice of (La,Sr)MnO.sub.3 that prefers a coordination number lower than 6 will induce oxygen ion vacancies to form in the lattice. Because the oxygen ion conductivity of (La,Sr)MnO.sub.3 is low over a very large temperature range, the material exhibits a high overpotential when used. The inclusion of oxygen vacancies into the lattice by doping the material has been found to maintain the desirable properties of (La,Sr)MnO.sub.3, while significantly decreasing the experimentally observed overpotential.

Vaughey, John (Elmhurst, IL); Krumpelt, Michael (Naperville, IL); Wang, Xiaoping (Downers Grove, IL); Carter, J. David (Bolingbrook, IL)

2003-01-01T23:59:59.000Z

480

High conductivity composite metal  

DOE Patents [OSTI]

Electrical conductors and methods of producing them are disclosed, where the conductors possess both high strength and high conductivity. Conductors are comprised of carbon steel and a material chosen from a group consisting of copper, nickel, silver, and gold. Diffusion barriers are placed between these two materials. The components of a conductor are assembled and then the assembly is subjected to heat treating and mechanical deformation steps. 10 figs.

Zhou, R.; Smith, J.L.; Embury, J.D.

1998-01-06T23:59:59.000Z

Note: This page contains sample records for the topic "thermal conductivity probe" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

High conductivity composite metal  

DOE Patents [OSTI]

Electrical conductors and methods of producing them, where the conductors possess both high strength and high conductivity. Conductors are comprised of carbon steel and a material chosen from a group consisting of copper, nickel, silver, and gold. Diffusion barriers are placed between these two materials. The components of a conductor are assembled and then the assembly is subjected to heat treating and mechanical deformation steps.

Zhou, Ruoyi (Los Alamos, NM); Smith, James L. (Los Alamos, NM); Embury, John David (Hamilton, CA)

1998-01-01T23:59:59.000Z

482

Futurestock'2003 9 International Conference on Thermal Energy Storage, Warsaw, POLAND  

E-Print Network [OSTI]

is also needed when designing a BTES (Borehole Thermal Energy Storage) system. The ground thermal381 Futurestock'2003 9 th International Conference on Thermal Energy Storage, Warsaw, POLAND, BTES, TED-measurement ABSTRACT The thermal conductivity of the ground and thermal resistance

483

Phonon Heat Conduction in Corrugated Silicon Nanowires Below the Casimir Limit Christophe Blanc,1  

E-Print Network [OSTI]

very low thermal conductances of highly rough silicon nanowires [7, 18], far below the amorphous limit, 2013) The thermal conductance of straight and corrugated monocrystalline silicon nanowires has been of nanostructured materials or low dimen- sional materials has attracted growing interest [1­4], es- pecially

Paris-Sud XI, Université de

484

The simple boundary element method for transient heat conduction in functionally graded materials  

E-Print Network [OSTI]

of functional material variation (quadratic, exponential and trigonometric) of thermal conductivity and specific, in an FGM, one face of a structural component is an engineering ceramic that can resist severe thermal ceramic and fracture- resisting metal can improve the properties of thermal barrier systems because

Paulino, Glaucio H.

485

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network [OSTI]

using aquifers for thermal energy storage. Problems outlinedmatical Modeling of Thermal Energy Storage in Aquifers,"ings of Aquifer Thermal Energy Storage Workshop, Lawrence

Tsang, C.-F.

2011-01-01T23:59:59.000Z

486

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network [OSTI]

aquifers for thermal energy storage. Problems outlined aboveModeling of Thermal Energy Storage in Aquifers," Proceed-ings of Aquifer Thermal Energy Storage Workshop, Lawrence

Tsang, C.-F.

2011-01-01T23:59:59.000Z

487

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network [OSTI]

using aquifers for thermal energy storage. Problems outlinedmatical Modeling of Thermal Energy Storage in Aquifers,"Proceed- ings of Aquifer Thermal Energy Storage Workshop,

Tsang, C.-F.

2011-01-01T23:59:59.000Z

488

Method and apparatus for remote tube crevice detection by current and voltage probe resistance measurement  

DOE Patents [OSTI]

A method and apparatus for determining the extent of contact between an electrically conducting tube and an electrically conductive tubesheet surrounding the tube, based upon the electrical resistance of the tube and tubesheet. A constant current source is applied to the interior of the electrically conducting tube by probes and a voltmeter is connected between other probes to measure the voltage at the point of current injection, which is inversely proportional to the amount of contact between the tube and tubesheet. Namely, the higher the voltage measured by the voltmeter, the less contact between the tube and tubesheet. 4 figs.

Kikta, T.J.; Mitchell, R.D.

1992-11-24T23:59:59.000Z

489

Probing the Kondo Lattice Model with Alkaline Earth Atoms  

E-Print Network [OSTI]

We study transport properties of alkaline-earth atoms governed by the Kondo Lattice Hamiltonian plus a harmonic confining potential, and suggest simple dynamical probes of several different regimes of the phase diagram that can be implemented with current experimental techniques. In particular, we show how Kondo physics at strong coupling, low density, and in the heavy fermion phase is manifest in the dipole oscillations of the conduction band upon displacement of the trap center.

Michael Foss-Feig; Michael Hermele; Ana Maria Rey

2009-12-24T23:59:59.000Z

490

Multiscale thermal transport.  

SciTech Connect (OSTI)

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.

Graham, Samuel Jr. (; .); Wong, C. C.; Piekos, Edward Stanley

2004-02-01T23:59:59.000Z

491

RESEARCHANDTECHNICALNOTES Thermal contraction of Vespel SP-22 and  

E-Print Network [OSTI]

materials is becoming common in low temperature apparatus. Vespel SP-22 has a thermal conductivity nearly of thermal contraction of such construction materials is often necessary for proper design of low temperature devices. We present here data on the total thermal contraction of these two materials, measured relative

Packard, Richard E.

492

Thermal resistance gaps for solid breeder blankets using packed beds  

SciTech Connect (OSTI)

The main design features of a new concept for solid breeder blanket thermal resistance gaps are described and analysis is shown for the blanket thermal characteristics. The effective thermal conductivity of a helium-beryllium packed bed configuration is studied, including the effect of a purge stream. Possible applications of this concept to ITER blanket designs are stressed.

Gorbis, Z.R.; Raffray, A.R.; Tillack, M.S.; Abdou, M.A.

1989-03-01T23:59:59.000Z

493

Thermal Via Placement in 3D ICs Brent Goplen  

E-Print Network [OSTI]

to these thermal conductivities in order to achieve a desired maximum temperature objective. Finite element, temperature, thermal gradient, placement, routing, finite element analysis, thermal via 1. INTRODUCTION cluster into parallel networks using the observation that heat transfer is much more efficient vertically

Sapatnekar, Sachin

494

Hand-held survey probe  

DOE Patents [OSTI]

A system for providing operational feedback to a user of a detection probe may include an optical sensor to generate data corresponding to a position of the detection probe with respect to a surface; a microprocessor to receive the data; a software medium having code to process the data with the microprocessor and pre-programmed parameters, and making a comparison of the data to the parameters; and an indicator device to indicate results of the comparison. A method of providing operational feedback to a user of a detection probe may include generating output data with an optical sensor corresponding to the relative position with respect to a surface; processing the output data, including comparing the output data to pre-programmed parameters; and indicating results of the comparison.

Young, Kevin L. (Idaho Falls, ID) [Idaho Falls, ID; Hungate, Kevin E. (Idaho Falls, ID) [Idaho Falls, ID

2010-02-23T23:59:59.000Z

495

Cross-plane thermal properties of transition metal dichalcogenides  

SciTech Connect (OSTI)

In this work, we explore the thermal properties of hexagonal transition metal dichalcogenide compounds with different average atomic masses but equivalent microstructures. Thermal conductivity values of sputtered thin films were compared to bulk crystals. The comparison revealed a >10 fold reduction in thin film thermal conductivity. Structural analysis of the films revealed a turbostratic structure with domain sizes on the order of 5-10 nm. Estimates of phonon scattering lengths at domain boundaries based on computationally derived group velocities were consistent with the observed film microstructure, and accounted for the reduction in thermal conductivity compared to values for bulk crystals.

Muratore, C. [Department of Chemical and Materials Engineering, University of Dayton, Dayton, Ohio 45469 (United States) [Department of Chemical and Materials Engineering, University of Dayton, Dayton, Ohio 45469 (United States); Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Varshney, V. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States) [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Universal Technology Corporation, Dayton, Ohio 45432 (United States); Gengler, J. J. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States) [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Spectral Energies LLC, Dayton, Ohio 45431 (United States); Hu, J. J.; Bultman, J. E. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States) [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); University of Dayton Research Institute, Dayton, Ohio 45469 (United States); Smith, T. M. [Department of Materials Science and Engineering, Ohio State University, Columbus, Ohio 43210 (United States)] [Department of Materials Science and Engineering, Ohio State University, Columbus, Ohio 43210 (United States); Shamberger, P. J.; Roy, A. K.; Voevodin, A. A. [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States)] [Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Ohio 45433 (United States); Qiu, B.; Ruan, X. [Department of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)] [Department of Mechanical Engineering and Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States)

2013-02-25T23:59:59.000Z

496

A boron nitride nanotube peapod thermal rectifier  

SciTech Connect (OSTI)

The precise guidance of heat from one specific location to another is paramount in many industrial and commercial applications, including thermal management and thermoelectric generation. One of the cardinal requirements is a preferential conduction of thermal energy, also known as thermal rectification, in the materials. This study introduces a novel nanomaterial for rectifying heat—the boron nitride nanotube peapod thermal rectifier. Classical non-equilibrium molecular dynamics simulations are performed on this nanomaterial, and interestingly, the strength of the rectification phenomenon is dissimilar at different operating temperatures. This is due to the contingence of the thermal flux on the conductance at the localized region around the scatterer, which varies with temperature. The rectification performance of the peapod rectifier is inherently dependent on its asymmetry. Last but not least, the favourable rectifying direction in the nanomaterial is established.

Loh, G. C., E-mail: jgloh@mtu.edu [Department of Physics, Michigan Technological University, Houghton, Michigan 49931 (United States); Institute of High Performance Computing, 1 Fusionopolis Way, #16-16 Connexis, Singapore 138632 (Singapore); Baillargeat, D. [CNRS-International-NTU-Thales Research Alliance (CINTRA), 50 Nanyang Drive, Singapore 637553 (Singapore)

2014