Temperature dependence of molar excess volumes for the dimethyl sulfoxide + thiophene system and thermal expansion coefficients between 293.15 and 313.15 K

1993 ◽  
Vol 38 (2) ◽  
pp. 270-273 ◽  
Author(s):  
Silvia B. Aznarez ◽  
Lelia Mussari ◽  
Miguel A. Postigo
Keyword(s):  
Thermal Expansion ◽  
Temperature Dependence ◽  
Dimethyl Sulfoxide ◽  
Excess Volumes ◽  
Molar Excess ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Molar Excess Volumes

Molar excess volumes of binary liquid mixtures: 2-pyrrolidinone with C6–C10n-alkanols

1996 ◽  
Vol 74 (1) ◽  
pp. 121-127 ◽  
Author(s):  
Begoña García ◽  
Francisco J. Hoyuelos ◽  
Rafael Alcalde ◽  
José M. Leal
Keyword(s):  
Steric Effect ◽  
Composition Range ◽  
Liquid Mixtures ◽  
Excess Volumes ◽  
Density Measurements ◽  
Binary Liquid ◽  
Thermal Expansion Coefficients ◽  
Maximum Value ◽  
Expansion Coefficients ◽  
Molar Excess Volumes

The excess volumes VE of the binary mixtures 2-pyrrolidinone–(C6–C10) n-alkanols have been calculated from density measurements over the whole composition range and the 298.15–318.15 K temperature range. The excess volumes were independent of temperature, but changed noticeably with the chain length of the alkanol. The VE values were only positive starting from heptanol, with the maximum value, 0.239 cm3 mol−1, for equimolar decanol. The observed changeover VE < 0 to VE > 0 suggests that the steric effect is primarily responsible for the positive contributions to VE. The thermal expansion coefficients α were evaluated from the variation of densities with temperature. Key words: excess volumes, 2-pyrrolidinone, n-alkanols, liquid mixtures, hydrogen bonding.

scholarly journals Studies on Thermophysical Properties of CaO and MgO by γ-Ray Attenuation

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
A. S. Madhusudhan Rao ◽  
K. Narender
Keyword(s):  
Thermal Expansion ◽  
Temperature Dependence ◽  
Thermophysical Properties ◽  
Linear Thermal Expansion ◽  
Temperature Dependent ◽  
Degree Polynomial ◽  
Attenuation Coefficients ◽  
Temperature Range ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients

The study on temperature dependent γ-ray attenuation and thermophysical properties of CaO and MgO has been carried out in the temperature range 300 K–1250 K using different energies of γ-beam, namely, Am (0.0595 MeV), Cs (0.66 MeV), and Co (1.173 MeV and 1.332 MeV) on γ-ray densitometer fabricated in our laboratory. The linear attenuation coefficients (μl) for the pellets of CaO and MgO as a function of temperature have been determined using γ-beam of different energies. The coefficients of temperature dependence of density have been reported. The variation of density and linear thermal expansion of CaO and MgO in the temperature range of 300 K–1250 K has been studied and compared with the results available in the literature. The temperature dependence of linear attenuation coefficients, density, and thermal expansion has been represented by second degree polynomial. Volume thermal expansion coefficients have been reported.

Thermal expansivities of water + tetrahydrofuran mixtures at 298.15 K

1978 ◽  
Vol 56 (22) ◽  
pp. 2803-2807 ◽  
Author(s):  
Osamu Kiyohara ◽  
Patrick J. D'Arcy ◽  
George C. Benson
Keyword(s):  
Thermal Expansion ◽  
Mole Fraction ◽  
Structural Changes ◽  
Molar Excess ◽  
Thermal Expansion Coefficients ◽  
Thermal Expansivities ◽  
Expansion Coefficients ◽  
Mole Fraction Range

Densities of water + tetrahydrofuran mixtures were measured at 5 K intervals of temperature from 288.15 to 308.15 K. Excess thermal expansion coefficients and partial molar excess thermal expansivities at 298.15 K over the whole mole fraction range were derived from the results. The significance of the expansivities is discussed in terms of the structural changes accompanying the formation of the mixture.

X-ray diffractometry of AlGaAs/GaAs superlattices and GaAs in the temperature range 5–295 K

1989 ◽  
Vol 22 (4) ◽  
pp. 372-375 ◽  
Author(s):  
G. Clec'h ◽  
G. Calvarin ◽  
P. Auvray ◽  
M. Baudet
Keyword(s):  
Thermal Expansion ◽  
Temperature Dependence ◽  
Low Temperatures ◽  
X Ray ◽  
Lattice Constants ◽  
Temperature Range ◽  
Thermal Expansion Coefficients ◽  
Gaas Substrates ◽  
Expansion Coefficients ◽  
Tetrahedrally Bonded

The temperature dependence of the lattice constants of Al x Ga1 − x As/GaAs superlattices MBE-grown on (001) oriented GaAs substrates was determined by X-ray diffractometry. The thermal expansion coefficients of these materials become negative at low temperatures, like that of GaAs and other tetrahedrally bonded covalent solids. The temperature dependence of the stress in these structures was also studied; although its value increases as temperature decreases, strain remains elastic down to 5 K.

The influence of the sapphire substrate on the temperature dependence of the GaN bandgap

1999 ◽  
Vol 572 ◽  
Author(s):  
Joachim Krüiger ◽  
Noad Shapiro ◽  
Sudhir Subramanya ◽  
Yihwan Kim ◽  
Henrik Siegle ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Temperature Dependence ◽  
Sapphire Substrate ◽  
Measured Temperature ◽  
Temperature Range ◽  
Thermal Expansion Coefficients ◽  
Small Influence ◽  
Expansion Coefficients ◽  
The Difference ◽  
First Time

ABSTRACTThis paper analyses the influence of the sapphire substrate on stress in GaN epilayers in the temperature range between 4K and 600K. Removal of the substrate by a laser assisted liftoff technique allows, for the first time, to distinguish between stress and other material specific temperature dependencies. In contrast to the prevailing assumption in the literature, that the difference in the thermal expansion coefficients is the main cause for stress it is found that the substrate has a rather small influence in the examined temperature range. The measured temperature dependence of stress is in contradiction to the published values for the thermal expansion coefficients for sapphire and GaN.

THERMAL EXPANSION OF FERROMAGNETIC SUPERCONDUCTORS: POSSIBLE APPLICATION TO UGe2

2010 ◽  
Vol 24 (25n26) ◽  
pp. 5192-5201
Author(s):  
NOBUKUNI HATAYAMA ◽  
RIKIO KONNO
Keyword(s):  
Free Energy ◽  
Thermal Expansion ◽  
Transition Temperature ◽  
Temperature Dependence ◽  
Conduction Band ◽  
Superconducting Transition Temperature ◽  
Superconducting Transition ◽  
Thermal Expansion Coefficients ◽  
Expansion Coefficients ◽  
Majority Spin

We investigate the temperature dependence of thermal expansion of the ferromagnetic triplet superconductors and their thermal expansion coefficients below the superconducting transition temperature of a majority spin conduction band. The free energy of the ferromagnetic superconductors derived by Linder et al. is used. The superconducting gaps in the A2 phase of 3 He and with a node in UGe 2 are considered. By applying Takahashi's method to the free energy, i.e. by taking into account the volume dependence of the free energy explicitly, the temperature dependence of the thermal expansion and the thermal expansion coefficients is studied below the superconducting transition temperature of the majority spin conduction band. We find that we have anomalies of the thermal expansion in the vicinity of the superconducting transition temperatures and that we have divergence of the thermal expansion coefficients are divergent at the superconducting transition temperatures. The Grüneisen's relation between the temperature dependence of the thermal expansion coefficients and the temperature dependence of the specific heat at low temperatures is satisfied.

Sign in / Sign up

Export Citation Format

Share Document