The Mid-Atlantic Ridge Near 45° N. XV. Thermal Conductivity of Dredge and Drill Core Samples

1971 ◽  
Vol 8 (3) ◽  
pp. 391-393 ◽  
Author(s):  
R. D. Hyndman ◽  
A. M. Jessop
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Drill Core ◽  
Core Samples ◽  
Mid Atlantic Ridge ◽  
Thermal Conductivities

Thermal conductivities have been measured on dredge samples and drill core from the Mid-Atlantic Ridge near 45° N. On the basis of these measurements and published heat flow values, crustal temperatures near the ridge are estimated.

THERMAL CONDUCTIVITY OF METALS AT HIGH TEMPERATURES: I. DESCRIPTION OF THE APPARATUS AND MEASUREMENTS ON IRON

1947 ◽  
Vol 25a (6) ◽  
pp. 357-374 ◽  
Author(s):  
L. D. Armstrong ◽  
T. M. Dauphinee
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
High Temperatures ◽  
Armco Iron ◽  
Absolute Error ◽  
Cylindrical Sample ◽  
Comprehensive Analysis ◽  
Temperature Curve ◽  
Temperature Range ◽  
Thermal Conductivities

An apparatus for measuring the thermal conductivity of metals in the temperature range 0° to 800 °C. is described. The method utilizes unidirectional heat flow in a cylindrical sample in a vacuum. The advantages of the method are outlined and a comprehensive analysis of possible errors in the measurements is included. Measurements on Armco iron indicate that results with an absolute error of less than 2% may be obtained. The results of measurements on a sample of Armco iron gave thermal conductivities of 0.1819 c.g.s units at 0 °C. and 0.0698 c.g.s. units at 800 °C. A change in slope of the thermal conductivity–temperature curve was found at a temperature of approximately 375 °C., and is tentatively attributed to the presence of 0.03% nickel impurity.

scholarly journals Determination of the anisotropic thermal conductivity of an aerogel-based plaster using transient plane source method

2021 ◽  
Vol 2069 (1) ◽  
pp. 012030
Author(s):  
A N Karim ◽  
B Adl-Zarrabi ◽  
P Johansson ◽  
A Sasic Kalagasidis
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Thermal Performance ◽  
Plane Source ◽  
Weak Anisotropy ◽  
Source Method ◽  
Transient Plane Source ◽  
Anisotropic Thermal Conductivity ◽  
Transient Plane Source Method ◽  
Thermal Conductivities

Abstract Aerogel-based plasters are composite materials with declared thermal conductivities in the range of traditional insulating materials, i.e. 30-50 mW/(m·K). Based on the results from reported field measurements, aerogel-based plasters can significantly reduce the thermal transmittance of uninsulated walls. However, the in-situ measured thermal conductivities have sometimes been higher than the declared values measured in laboratory and in the main direction of the heat flow. Meanwhile, the anisotropic thermal performance of aerogel-based plasters, i.e., deviating thermal performance in the different directions of heat flow, has not been explored yet. The objective of this study is thus to evaluate the anisotropic thermal conductivity of an aerogel-based plaster. This is done in a set of laboratory measurements using the transient plane source method. Six identical and cubic samples with the dimensions of 10×10×10 cm3 were paired two and two, creating three identical sample sets. In total, 360 measurements of thermal conductivity and thermal diffusivity, and 130 measurements for specific heat capacity were conducted. The results indicate a weak anisotropy of less than ±6.5 % between the three directions (x, y, z). Considering the accuracy of the selected measurement technique, better than ±5 %, supplementary measurements using another technique are recommended.

scholarly journals Methods to Invert Temperature Data and Heat Flow Data for Thermal Conductivity in Steady-State Conductive Regimes

Geosciences ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 293
Author(s):  
Wallace Anderson McAliley ◽  
Yaoguo Li
Keyword(s):  
Thermal Conductivity ◽  
Steady State ◽  
Heat Flow ◽  
Temperature Data ◽  
Geophysical Data ◽  
Specific Information ◽  
Data Sets ◽  
Flow Data ◽  
Thermal Data ◽  
Thermal Conductivities

Temperature and heat flow data carry specific information about the distribution of thermal conductivity variations which is not available in other geophysical data sets. Thus, thermal data constitute important complementary data sets in the multiphysics-based imaging and characterization of earth’s subsurface. The quantitative interpretations that accompany this effort can be carried out by determining thermal conductivities from temperature or heat flow data. Towards this goal, we develop inversion methods based on Tikhonov regularization and numerical solution of the differential equations governing the steady-state heat equation. Numerical simulations using these methods yield insights into the information content in thermal data and indicate it is similar to that in potential-field data. We apply the temperature inversion method to borehole temperature data from the Cooper Basin in Australia, a well-studied geothermal prospect. The methods and insights presented in this study pave the way for imaging the subsurface through recovered thermal conductivities and for joint quantitative interpretations of thermal data with other common geophysical data sets in various geoscientific applications.

scholarly journals The thermal conductivities of certain liquids

1928 ◽  
Vol 117 (777) ◽  
pp. 459-470 ◽  
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Horizontal Layer ◽  
Small Temperature ◽  
The Past ◽  
Temperature Ranges ◽  
Thermal Conductivities

The determination of the thermal conductivity of liquids and the variation with temperature has received the attention of a number of workers in the past, notably, Lees in 1898, R. Weber in 1903, and Goldschmidt in 1911. In general, however, the temperature ranges explored were somewhat restricted, and the present work was accordingly directed to determining the conductivities of a number of the more common liquids up to the highest temperatures feasible. In measuring the thermal conductivity of a liquid it is, of course, essential that convection effects should be reduced to a minimum. This may be effected by employing small temperature differences across a thin horizontal layer of the liquid, the heat flow being directed downwards.

METHOD FOR DETERMINING TERRESTRIAL HEAT FLOW IN OIL FIELDS

Geophysics ◽  
1977 ◽  
Vol 42 (3) ◽  
pp. 584-593 ◽  
Author(s):  
Humberto Da Silva Carvalho ◽  
Victor Vacquier
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Sedimentary Basins ◽  
Oil Fields ◽  
Inexpensive Method ◽  
Average Heat ◽  
Core Samples ◽  
Bottom Hole ◽  
Terrestrial Heat Flow ◽  
The World

A method of determining terrestrial heat flow in oil fields from bottom‐hole temperatures, electric logs, and thermal conductivity of core samples has been tried in six Reco⁁ncavo Basin oil fields in Brazil. The average heat‐flow value so determined for the Reco⁁ncavo Basin is [Formula: see text]. The technique can be used for calculating heat flow in continental areas elsewhere. A more significant outcome of our experiment is that it demonstrates an inexpensive method of obtaining terrestrial heat‐flow values in the sedimentary basins of the world.

scholarly journals Shallow subsurface thermal structure onshore Denmark: temperature, thermal conductivity and heat flow

2020 ◽  
Vol 67 ◽  
pp. 29-52
Author(s):  
Ingelise Møller ◽  
Niels Balling ◽  
Claus Ditlefsen
Keyword(s):  
Thermal Conductivity ◽  
Heat Flow ◽  
Thermal Structure ◽  
Temperature Gradients ◽  
Core Material ◽  
Clear Correlation ◽  
Mean Values ◽  
Shallow Subsurface ◽  
Clay Deposits ◽  
Thermal Conductivities

Available measured temperatures and thermal conductivities covering Danish onshore areas to a depth of about 300 m have been compiled and analysed. Temperature data from 236 borehole sites, including 56 boreholes with detailed temperature profiles, are applied together with thermal conductivities mea- sured on samples collected at 34 well-characterised outcrops and on core material from 20 boreholes. Significant thermal variations in the shallow subsurface are observed. At a depth of 50 m, a mean temperature of 8.9 ± 0.8°C is found, close to the mean annual surface temperature. Higher mean values of 9.7 ± 1.1°C found at 100 m and 11.6 ± 2.2°C at 200 m reflect a general increase of temperatures with depth. In contrast to the assumption commonly held, we observe significant lateral variations both lo- cally and regionally. At a depth of 100 m, temperatures vary between 7.3 and 13.0°C across Denmark, and at 250 m between 9.6 and 17.9°C. Mean values of the thermal conductivities lie within a range of 0.6–6 W/(m·K) measured water- saturated at laboratory conditions. The majority of values are within the interval of 1–3 W/(m·K) and show a strong correlation with lithology. The content of quartz and the rock porosity (the content of water) are found to be two main factors controlling the observed variations. Characteristic temperature gradients are in the range 1–4°C/100 m. Following Fourier’s law of heat conduction, a clear correlation is observed between temperature gradients and thermal conductivities of different lithologies. Intervals of quartz-rich sand deposits with high thermal conductivity show low temperature gradients, chalk and limestone intervals with intermediate conductivity display intermediate gradients, while sections with fine grained clay deposits of low thermal conductivity show high gradient values. A correlation analysis provides an estimate of regional shallow heat flow of 37 ± 5 mW/m2, consistent with local, classically determined heat-flow values from shallow borehole data. However, it is significantly below deep background heat flow, and this is believed to be caused by long-term paleoclimatic effects. The shallow subsurface thermal regime across the Danish area is largely controlled by thermal conduction. Only locally, and in rare cases, do we observe temperature perturbations due to ground- water migration. In addition to general geoscientific purposes, our results are important for several applications including exploitation of shallow geothermal energy and the use of the subsurface for heat storage and cooling purposes.

AN INSTRUMENT FOR MEASURING HEAT FLOW, TEMPERATURE, AND THERMAL CONDUCTIVITY IN THE LUNAR SURFACE LAYER

1970 ◽  
Author(s):  
A. E. Wechsler ◽  
E. M. Drake ◽  
F. E. Ruccia ◽  
J. E. McCullough ◽  
P. Felsenthal ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Surface Layer ◽  
Heat Flow ◽  
Lunar Surface ◽  
Flow Temperature
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