Thermal Conductivity of Selected Materials
Total Page:16
File Type:pdf, Size:1020Kb
Load more
Recommended publications
-
Effect of Glass Transition: Density and Thermal Conductivity Measurements of B2O3
High Temperatures-High Pressures, Vol. 49, pp. 125–142 ©2020 Old City Publishing, Inc. Reprints available directly from the publisher Published by license under the OCP Science imprint, Photocopying permitted by license only a member of the Old City Publishing Group DOI: 10.32908/hthp.v49.801 Effect of glass transition: density and thermal conductivity measurements of B2O3 DMITRY CHEBYKIN1*, HANS-PETER HELLER1, IVAN SAENKO2, GERT BARTZSCH1, RIE ENDO3 AND OLENA VOLKOVA1 1Institute of Iron and Steel Technology, TU Bergakademie Freiberg, Leipziger Straße 34, 09599 Freiberg, Germany 2Institute of Materials Science, TU Bergakademie Freiberg, Gustav-Zeuner-Straße 5, 09599 Freiberg, Germany 3Department of Materials Science and Engineering, Tokyo Institute of Technology, 152–8552 Tokyo, Japan Received: May 28, 2019; Accepted: October 11, 2019. The role of B2O3 as a fluxing agent for developing fluoride free fluxes has been accentuated in the recent years. Therefore, knowledge about thermo- physical properties of the oxide are essential to find the optimal chemical composition of the mold fluxes. In the present study, the density and ther- mal conductivity of B2O3 were measured by means of the buoyancy method, the maximal bubble pressure (MBP) method and the hot-wire method in the temperature range of 295–1573 K. The results are discussed in the context of the chemical stability of the B2O3 as well as the effect of glass transition on the thermal conductivity. The density of the B2O3 decreases non-linearly with increasing temperature in the temperature range of 973–1573 K. The MBP method was successfully applied for the density measurements with a viscosity up to 91 Pa.s. -
R09 SI: Thermal Properties of Foods
Related Commercial Resources CHAPTER 9 THERMAL PROPERTIES OF FOODS Thermal Properties of Food Constituents ................................. 9.1 Enthalpy .................................................................................... 9.7 Thermal Properties of Foods ..................................................... 9.1 Thermal Conductivity ................................................................ 9.9 Water Content ........................................................................... 9.2 Thermal Diffusivity .................................................................. 9.17 Initial Freezing Point ................................................................. 9.2 Heat of Respiration ................................................................. 9.18 Ice Fraction ............................................................................... 9.2 Transpiration of Fresh Fruits and Vegetables ......................... 9.19 Density ...................................................................................... 9.6 Surface Heat Transfer Coefficient ........................................... 9.25 Specific Heat ............................................................................. 9.6 Symbols ................................................................................... 9.28 HERMAL properties of foods and beverages must be known rizes prediction methods for estimating these thermophysical proper- Tto perform the various heat transfer calculations involved in de- ties and includes examples on the -
THERMAL CONDUCTIVITY of CONTINUOUS CARBON FIBRE REINFORCED COPPER MATRIX COMPOSITES J.Koráb1, P.Šebo1, P.Štefánik 1, S.Kavecký 1 and G.Korb 2
1. THERMAL CONDUCTIVITY OF CONTINUOUS CARBON FIBRE REINFORCED COPPER MATRIX COMPOSITES J.Koráb1, P.Šebo1, P.Štefánik 1, S.Kavecký 1 and G.Korb 2 1 Institute of Materials and Machine Mechanics of the Slovak Academy of Sciences, Racianska 75, 836 06 Bratislava, Slovak Republic 2 Austrian Research Centre Seibersdorf, A-2444 Seibersdorf, Austria SUMMARY: The paper deals with thermal conductivity of the continuous carbon fibre reinforced - copper matrix composite that can be applied in the field of electric and electronic industry as a heat sink material. The copper matrix - carbon fibre composite with different fibre orientation and fibre content was produced by diffusion bonding of copper-coated carbon fibres. Laser flash technique was used for thermal conductivity characterisation in direction parallel and transverse to fibre orientation. The results revealed decreasing thermal conductivity as the volume content of fibre increased and independence of through thickness conductivity on fibre orientation. Achieved results were compared with the materials that are currently used as heat sinks and possibility of the copper- based composite application was analysed. KEYWORDS: thermal conductivity, copper matrix, carbon fibre, metal matrix composite, heat sink, thermal management, heat dissipation INTRODUCTION Carbon fibre reinforced - copper matrix composite (Cu-Cf MMC) offer thermomechanical properties (TMP) which are now required in electronic and electric industry. Their advantages are low density, very good thermal conductivity and tailorable coefficient of thermal expansion (CTE). These properties are important in the applications where especially thermal conductivity plays large role to solve the problems of heat dissipation due to the usage of increasingly powerful electronic components. In devices, where high density mounting technology is applied thermal management is crucial for the reliability and long life performance. -
THERMO POWER of Kr IMPLANTED MANGANIN- Cu THERMOCOUPLE T
Solid State Physics ANNUAL REPORT 2005 THERMO POWER OF Kr IMPLANTED MANGANIN- Cu THERMOCOUPLE T. WilczyĔ ska, R. WiĞ niewski, K. Wieteska Institute of Atomic Energy Low electric thermo power of manganin (Cu- junctions were placed into small glass containers insu- Mn_Ni alloy) relative to the copper is an advantage of lated thermally from each other by polystyrene box. The manganin alloy. The aim of this investigation was to hot junction container had suitable electrical heater. check if electric thermo power remains low after im- Temperature of the junctions was measured with mer- plantation with Kr ions. The work described is part of cury micro thermometer or an additional constantan- wide projected concerned with studies on properties of copper thermocouple. manganin implanted with various heavy ions [1]. Our measurements revealed that implantation of The 10P m thick stripe samples of 1 × 75mm were manganin with Kr ions reduces its thermo power rela- implanted with Kr ions in Laboratory of Nuclear Reac- tive to copper by ~50%. Another result of our study is tion at Joint Institute for Nuclear Research, Dubna. A that thermo power of non implanted manganin relative moderation aluminum foil of 11P m thick and 3mm to Cu is a little lower than given in literature. width was used. According to modeling performed with To assess the origin of such significant decrease in TRIM code [2] implantation produced the enhanced thermo EMF after implantation the thermally forced deposition layer near the back side of sample (Fig. 1). electron diffusion in junctions, contact potential and After implantation the samples were annealed for 100h o phonon forced electron drag components of the Seebeck at 130 - 150 C. -
Carbon Epoxy Composites Thermal Conductivity at 77 K and 300 K Jean-Luc Battaglia, Manal Saboul, Jérôme Pailhes, Abdelhak Saci, Andrzej Kusiak, Olivier Fudym
Carbon epoxy composites thermal conductivity at 77 K and 300 K Jean-Luc Battaglia, Manal Saboul, Jérôme Pailhes, Abdelhak Saci, Andrzej Kusiak, Olivier Fudym To cite this version: Jean-Luc Battaglia, Manal Saboul, Jérôme Pailhes, Abdelhak Saci, Andrzej Kusiak, et al.. Carbon epoxy composites thermal conductivity at 77 K and 300 K. Journal of Applied Physics, American Institute of Physics, 2014, 115 (22), pp.223516-1 - 223516-4. 10.1063/1.4882300. hal-01063420 HAL Id: hal-01063420 https://hal.archives-ouvertes.fr/hal-01063420 Submitted on 12 Sep 2014 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Science Arts & Métiers (SAM) is an open access repository that collects the work of Arts et Métiers ParisTech researchers and makes it freely available over the web where possible. This is an author-deposited version published in: http://sam.ensam.eu Handle ID: .http://hdl.handle.net/10985/8502 To cite this version : Jean-Luc BATTAGLIA, Manal SABOUL, Jérôme PAILHES, Abdelhak SACI, Andrzej KUSIAK, Olivier FUDYM - Carbon epoxy composites thermal conductivity at 80 K and 300 K - Journal of Applied Physics - Vol. 115, n°22, p.223516-1 - 223516-4 - 2014 Any correspondence concerning this service should be sent to the repository Administrator : [email protected] Carbon epoxy composites thermal conductivity at 80 K and 300 K J.-L. -
Chapter 25 Resistance and Current
Chapter 25 Resistance and Current Current in Wires • We define the Ampere (amp) to be one Coulomb of charge flow per second • A Coulomb is about 7 x 1018 electrons (or protons) of charge • For reference a “mole” is about 6.02 x 1023 units • Thus a “mole” of Copper 63.5 g/mole (z=29, A=63 (69.15% - 34 Neutrons, A=65 ( 30.85% - 36 Neutrons ) • Contains about 3 x 106 Coulombs BUT only outer electrons are free to move (4S1 state) – one electron per Cu atom in “valence band” • Density of Copper is about 8.9 g/cm3 • Density of free electrons in Cu ~ 1.4 x 104 Coul/cm3 • Or density of free electrons ~ 1023 e/cm3 A bit of History • chalkos (χαλκός) in Greek • Cyprium in Roman times as it was found in Cyprus • This was simplified to Cuprum in Latin and then • Copper in English • Copper mined in what is now Wisconsin 6000-3000 BCE • Copper plumbing found in Egyptian pyramid 3000 BCE • Small amount of Tin (Sn) helps in casting – Bronze (Cu-Sn) Ancient mine in Timna Valley – Negev Israel Current in wire • Lets assume a metal wire has n free charges/ vol • Assume the wire has cross sectional area A • Assume the charges (electrons) move at “drift speed” vd • Lets follow a section of charge q in length x • q = n*A*x (n*volume)e • Where e = electron charge • This volume move (drifts) at speed vd • This charge moves thru x in time • t = x/vd • The current is I= q/t = n*A*x*e/ (x/vd ) = nAvde , Wire gauges AWG – American Wire Gauge • Larger wire gauge numbers are smaller size wire • By definition 36 gauge = 0.005 inches diam • By definition 0000 gauge “4 -
Measurements of the Thermal Conductivity and Electrical Resistivity of Platinum from 373 to 1373° K
NATIONAL BUREAU OF STANDARDS REPORT 9387 MEASUREMENTS OF THE THERMAL CONDUCTIVITY AND ELECTRICAL RESISTIVITY OF PLATINUM FROM 373 TO 1373° K by D. R. Flynn Environmental Engineering Section Building Research Division Institute for Applied Technology National Bureau of Standards and M. E. O' Hagan School of Engineering and Applied Science The George Washington University DO NOT REFERENCE THIS DOCUMENT U. S. DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS — THE NATIONAL BUREAU OF STANDARDS The National Bureau of Standards 1 provides measurement and technical information services essential to the efficiency and effectiveness of the work of the Nation’s scientists and engineers. The Bureau serves also as a focal point in the Federal Government for assuring maximum application of the physical and engineering sciences to the advancement of technology in industry and commerce. To accomplish this mission, the Bureau is organized into three institutes covering broad program areas of research and services: THE INSTITUTE FOR BASIC STANDARDS . provides the central basis within the United States for a complete and consistent system of physical measurements, coordinates that system with the measurement systems of other nations, and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation’s scientific community, industry, and commerce. This Institute comprises a series of divisions, each serving a classical subject matter area: —Applied Mathematics—Electricity—Metrology—Mechanics—Heat—Atomic Physics—Physical 2 - 2 Chemistry—Radiation Physics—Laboratory Astrophysics —Radio Standards Laboratory , which includes Radio Standards Physics and Radio Standards Engineering—Office of Standard Refer- ence Data. THE INSTITUTE FOR MATERIALS RESEARCH . conducts materials research and provides associated materials services including mainly reference materials and data on the properties of ma- terials. -
The Viscosity and Thermal Conductivity Coefficients of Dilute Nitrogen and Oxygen
jras : .<; : .:' '.: » l\l 1 ^rf' ' » * ^ 1 350 The Viscosity and Thermal Conductivity Coefficients of Dilute Nitrogen and Oxygen G. E. CHI LDS AND H. J. M. HANLEY F *** ° Cf »* U.S. DEPARTMENT OF COMMERCE ,&': Z (A National Bureau of Standards \ n ' *"*C A U O? — THE NATIONAL BUREAU OF STANDARDS The National Bureau of Standards 1 provides measurement and technical information services essential to the efficiency and effectiveness of the work of the Nation's scientists and engineers. The Bureau serves also as a focal point in the Federal Government for assuring maximum application of the physical and engineering sciences to the advancement of technology in industry and commerce. To accomplish this mission, the Bureau is organized into three institutes covering broad program areas of research and services: THE INSTITUTE FOR BASIC STANDARDS . provides the central basis within the United States for a complete and consistent system of physical measurements, coordinates that system with the measurement systems of other nations, and furnishes essential services leading to accurate and uniform physical measurements throughout the Nation's scientific community, industry, and commerce. This Institute comprises a series of divisions, each serving a classical subject matter area: —Applied Mathematics—Electricity—Metrology—Mechanics —Heat—Atomic Physics—Physical Chemistry—Radiation Physics—Laboratory Astrophysics 2—Radio Standards Laboratory, 2 which includes Radio Standards Physics and Radio Standards Engineering—Office of Standard Refer- ence Data. THE INSTITUTE FOR MATERIALS RESEARCH . conducts materials research and provides associated materials services including mainly reference materials and data on the properties of ma- terials. Beyond its direct interest to the Nation's scientists and engineers, this Institute yields services which are essential to the advancement of technology in industry and commerce. -
Thermodynamic Temperature
Thermodynamic temperature Thermodynamic temperature is the absolute measure 1 Overview of temperature and is one of the principal parameters of thermodynamics. Temperature is a measure of the random submicroscopic Thermodynamic temperature is defined by the third law motions and vibrations of the particle constituents of of thermodynamics in which the theoretically lowest tem- matter. These motions comprise the internal energy of perature is the null or zero point. At this point, absolute a substance. More specifically, the thermodynamic tem- zero, the particle constituents of matter have minimal perature of any bulk quantity of matter is the measure motion and can become no colder.[1][2] In the quantum- of the average kinetic energy per classical (i.e., non- mechanical description, matter at absolute zero is in its quantum) degree of freedom of its constituent particles. ground state, which is its state of lowest energy. Thermo- “Translational motions” are almost always in the classical dynamic temperature is often also called absolute tem- regime. Translational motions are ordinary, whole-body perature, for two reasons: one, proposed by Kelvin, that movements in three-dimensional space in which particles it does not depend on the properties of a particular mate- move about and exchange energy in collisions. Figure 1 rial; two that it refers to an absolute zero according to the below shows translational motion in gases; Figure 4 be- properties of the ideal gas. low shows translational motion in solids. Thermodynamic temperature’s null point, absolute zero, is the temperature The International System of Units specifies a particular at which the particle constituents of matter are as close as scale for thermodynamic temperature. -
Determination of Thermal Conductivity, Specific Heat and Thermal
Biosystems Engineering (2002) 82 (2), 169–176 doi:10.1006/bioe.2002.0066, available online at http://www.idealibrary.com on PH}Postharvest Technology Determination of Thermal Conductivity, Specific Heat and Thermal Diffusivity of Borage Seeds W. Yang1; S. Sokhansanj2; J. Tang3; P. Winter4 1 Department of Food Science, University of Arkansas, 2650 N. Young Ave., Fayetteville, AR 72704, USA; e-mail of corresponding author: [email protected] 2 Oak Ridge National Lab, Bioenergy Feedstock Development Program, Oak Ridge, TN 37831-6422, USA; e-mail: [email protected] 3 Food Engineering Program, Department of Biological Systems Engineering, Washington State University, Pullman, WA 99164-6120, USA; e-mail: [email protected] 4 Hinz Automation, Inc., 410 Jessop Ave., Saskatoon, SK, Canada S7N 2S5; e-mail: [email protected] (Received 16 March 1999; accepted in revised form 15 February 2002; published online 11 June 2002) Thermal conductivity, specific heat capacity and thermal diffusivity of borage (Borago officinalis) seeds were determined at temperatures ranging from 6 to 208C and moisture contents from 1Á2to30Á3% w.b. The thermal conductivity was measured by the transient technique using a line heat source. The maximum slope method was used to analyse the line source heating data for thermal conductivity determination. The specific heat capacity was measured by different scanning calorimetry and ranged from 0Á77 to 1Á99 kJ kgÀ1KÀ1. The thermal conductivity of borage seeds ranged from 0Á11 to 0Á28 W mÀ1 KÀ1 and increased with moisture content in the range of 1Á2–30Á3% w.b. The thermal diffusivity ranged from 2Á32 Â 10À7 to 3Á18 Â 10À7 m2 sÀ1. -
Thermal Properties of Water
Forschungszentrum Karlsruhe Technik und Umwelt issenscnatiiK FZKA 5588 Thermal Properties of Water K. Thurnay Institut für Neutronenphysik und Reaktortechnik Projekt Nukleare Sicherheitsforschung Juni 1995 Forschungszentrum Karlsruhe Technik und Umwelt Wissenschaftliche Berichte FZKA 5588 Thermal Properties of Water K.Thurnay Institut für Neutronenphysik und Reaktortechnik Projekt Nukleare Sicherheitsforschung Forschungszentrum Karlsruhe GmbH, Karlsruhe 1995 Als Manuskript gedruckt Für diesen Bericht behalten wir uns alle Rechte vor Forschungszentrum Karlsruhe GmbH Postfach 3640, 76021 Karlsruhe ISSN 0947-8620 Abstract The report describes AQUA, a code developed in the Forschungszentrum Karlsruhe to calculate thermal properties of the water in steam explosions. AQUA bases on the H.G.K, water code, yet supplies - besides of the pressure and heat capacity functions - also the thermal conductivity, viscosity and the surface tension. AQUA calculates in a new way the thermal properties in the two phase region, which is more realistic as the one used in the H.G.K, code. AQUA is equipped with new, fast runnig routines to convert temperature-density dependent states into temperature-pressure ones. AQUA has a version to be used on line and versions adapted for batch calculations. A complete description of the code is included. Thermische Eigenschaften des Wassers. Zusammenfassung. Der Bericht befaßt sich mit dem Code AQUA. AQUA wurde im Forschungszentrum Karlsruhe entwickelt um bei der Untersuchung von Dampfexplosionen die thermischen Eigenschaften des Wassers zu liefern. AQUA ist eine Fortentwicklung des H.G.K.-Wassercodes, aber er berechnet - neben Druck- und Wärmeeigenschaften - auch die Wärmeleitfähigket, die Viskosität und die Oberflächenspannung. Im Zweiphasenge• biet beschreibt AQUA die thermischen Eigenschaften mit einer neuen Methode, die real• istischer ist, als das in der H.G.K.-Code dargebotene Verfahren. -
Thermal Conductivity 1 Thermal Conductivity
Thermal conductivity 1 Thermal conductivity In physics, thermal conductivity, , is the property of a material's ability to conduct heat. It appears primarily in Fourier's Law for heat conduction. Thermal conductivity is measured in watts per kelvin-meter (W·K−1·m−1, i.e. W/(K·m) or in IP units (Btu·hr−1·ft−1·F−1, i.e. Btu/(hr·ft⋅F). Multiplied by a temperature difference (in kelvins, K) and an area (in square meters, m2), and divided by a thickness (in meters, m), the thermal conductivity predicts the rate of energy loss (in watts, W) through a piece of material. In the window building industry "thermal conductivity" is expressed as the U-Factor [1], which measures the rate of heat transfer and tells you how well the window insulates. U-factor values are generally recorded in IP units (Btu/(hr·ft⋅F)) and usually range from 0.15 to 1.25. The lower the U-factor, the better the window insulates. The reciprocal of thermal conductivity is thermal resistivity. Measurement There are a number of ways to measure thermal conductivity. Each of these is suitable for a limited range of materials, depending on the thermal properties and the medium temperature. There is a distinction between steady-state and transient techniques. In general, steady-state techniques are useful when the temperature of the material does not change with time. This makes the signal analysis straightforward (steady state implies constant signals). The disadvantage is that a well-engineered experimental setup is usually needed. The Divided Bar (various types) is the most common device used for consolidated rock samples.