The Experts below are selected from a list of 143433 Experts worldwide ranked by ideXlab platform
A P Mackenzie - One of the best experts on this subject based on the ideXlab platform.
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high sensitivity Heat Capacity measurements on sr2ruo4 under uniaxial pressure
Proceedings of the National Academy of Sciences of the United States of America, 2021Co-Authors: Naoki Kikugawa, D A Sokolov, Fabian Jerzembeck, Alexandra S Gibbs, Yoshiteru Maeno, Clifford W Hicks, Jorg Schmalian, M Nicklas, A P MackenzieAbstract:A key question regarding the unconventional superconductivity of S r 2 R u O 4 remains whether the order parameter is single- or two-component. Under a hypothesis of two-component superconductivity, uniaxial pressure is expected to lift their degeneracy, resulting in a split transition. The most direct and fundamental probe of a split transition is Heat Capacity. Here, we report measurement of Heat Capacity of samples subject to large and highly homogeneous uniaxial pressure. We place an upper limit on the Heat-Capacity signature of any second transition of a few percent of that of the primary superconducting transition. The normalized jump in Heat Capacity, Δ C / C , grows smoothly as a function of uniaxial pressure, favoring order parameters which are allowed to maximize in the same part of the Brillouin zone as the well-studied van Hove singularity. Thanks to the high precision of our measurements, these findings place stringent constraints on theories of the superconductivity of S r 2 R u O 4 .
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high sensitivity Heat Capacity measurements on sr2ruo4 under uniaxial pressure
Proceedings of the National Academy of Sciences of the United States of America, 2021Co-Authors: Naoki Kikugawa, D A Sokolov, Fabian Jerzembeck, Alexandra S Gibbs, Yoshiteru Maeno, Clifford W Hicks, Jorg Schmalian, M Nicklas, A P MackenzieAbstract:A key question regarding the unconventional superconductivity of [Formula: see text] remains whether the order parameter is single- or two-component. Under a hypothesis of two-component superconductivity, uniaxial pressure is expected to lift their degeneracy, resulting in a split transition. The most direct and fundamental probe of a split transition is Heat Capacity. Here, we report measurement of Heat Capacity of samples subject to large and highly homogeneous uniaxial pressure. We place an upper limit on the Heat-Capacity signature of any second transition of a few percent of that of the primary superconducting transition. The normalized jump in Heat Capacity, [Formula: see text], grows smoothly as a function of uniaxial pressure, favoring order parameters which are allowed to maximize in the same part of the Brillouin zone as the well-studied van Hove singularity. Thanks to the high precision of our measurements, these findings place stringent constraints on theories of the superconductivity of [Formula: see text].
Yu P Zaikov - One of the best experts on this subject based on the ideXlab platform.
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isobaric Heat Capacity of molten halide eutectics
Journal of Thermal Analysis and Calorimetry, 2017Co-Authors: A A Redkin, I. V. Korzun, T Yaroslavtseva, Olga G Reznitskikh, Yu P ZaikovAbstract:The isobaric Heat Capacity of molten eutectic mixtures LiCl–CsCl, LiCl–KCl–CsCl, LiBr–KBr, LiBr–CsBr and LiBr–KBr–CsBr was measured at temperatures not above 150 K above melting point using differential scanning calorimetry. The molar Heat Capacity of all mixtures under study was found to be close to that of pure salts in a molten state. The excess Heat Capacity is proportional to the negative enthalpy of mixing.
George I. Makhatadze - One of the best experts on this subject based on the ideXlab platform.
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Contribution of hydration and non-covalent interactions to the Heat Capacity effect on protein unfolding
Journal of molecular biology, 1992Co-Authors: Peter L. Privalov, George I. MakhatadzeAbstract:The Heat Capacity change upon protein unfolding has been analysed using the Heat Capacity data for the model compounds' transfer into water, corrected for volume effects. It has been shown that in the unfolding, the Heat Capacity increment is contributed to by the effect of hydration of the non-polar groups, which is positive and decreases with temperature increase, and by the effect of hydration of the polar groups, which is negative and decreases in magnitude as temperature increases. The sum of these two effects is very close to the total Heat Capacity increment of protein unfolding at room temperature but is likely to deviate from it at higher temperatures. Therefore, the expected Heat Capacity effect caused by the increase of configurational freedom of the polypeptide chain upon unfolding seems to be compensated for by some other effect, perhaps associated with fluctuation of the native protein structure.
Donghyun Shin - One of the best experts on this subject based on the ideXlab platform.
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enhanced specific Heat Capacity of high temperature molten salt based nanofluids
International Journal of Heat and Mass Transfer, 2013Co-Authors: Hani Tiznobaik, Donghyun ShinAbstract:Abstract Four different sized silicon-dioxide nanoparticles (5, 10, 30, and 60 nm in diameter) were dispersed in a molten salt eutectic (lithium carbonate and potassium carbonate, 62:38 by molar ratio) to obtain high temperature operating fluids (nanomaterials). A modulated differential scanning calorimeter was employed to measure the specific Heat Capacity of the molten salt eutectic and nanomaterials (molten salt/nanoparticle mixture). The specific Heat Capacity of nanomaterials was enhanced by evenly 25% over that of the base molten salt eutectic (base fluid), regardless of the size of embedded nanoparticles. The measurement uncertainty of experiments was less than 5%. Material characteristic analyses using electron microscopy show that the addition of nanoparticles into the molten salt eutectic induces nearby molten salts to form needle-like structures. These special structures were only observed within the nanomaterials whose specific Heat Capacity was significantly enhanced. The observed enhancements in specific Heat Capacity can be explained by the high specific surface energies that are associated with the high surface areas of the embedded nanoparticles and the needle-like structures induced by the nanoparticle addition.
G J Snyder - One of the best experts on this subject based on the ideXlab platform.
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relating phase transition Heat Capacity to thermal conductivity and effusivity in cu2se
Physica Status Solidi-rapid Research Letters, 2016Co-Authors: David R Brown, Richard Heijl, Kasper A Borup, Bo B Iversen, Anders Palmqvist, G J SnyderAbstract:Accurate measurement of thermal conductivity is essential to determine the thermoelectric figure-of-merit, zT. Near the phase transition of Cu2Se at 410 K, the transport properties change rapidly with temperature, and there is a concurrent peak in measured Heat Capacity from differential scanning calorimetry (DSC). Interpreting the origin as a broad increase in Heat Capacity or as a transient resulted in a three-fold difference in the reported zT in two recent publications. To resolve this discrepancy, thermal effusivity was deduced from thermal conductivity and diffusivity measurements via the transient plane source (TPS) method and compared with that calculated from thermal diffusivity and the two interpretations of the DSC data for Heat Capacity. The comparison shows that the DSC measurement gave the Heat Capacity relevant for calculation of the thermal conductivity of Cu2Se. The thermal conductivity calculated this way follows the electronic contribution to thermal conductivity closely, and hence the main cause of the zT peak is concluded to be the enhanced Seebeck coefficient.
