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Jerzy Szydlowski - One of the best experts on this subject based on the ideXlab platform.

  • 18o 16o Isotope Effect on miscibility of isobutyric acid with water
    Journal of Physical Chemistry B, 2007
    Co-Authors: Agnieszka Siporska, And Anna Makowska, Jerzy Szydlowski
    Abstract:

    The miscibility of isobutyric acid with water and the influence of the Isotope substitution of oxygen (16O/18O) in water over a broad concentration range are reported. The system exhibits a phase diagram with an upper critical solution temperature (UCST) and a visible Isotope Effect thereon. The oxygen Isotope substitution decreases the UCST, leading to better miscibility of isobutyric acid with water. The Isotope shift, ΔTc = Tc(18O) − Tc(16O), extrapolated to the 100% enrichment in 18O, is equal to −1.15 K; hence it is much smaller and opposite to that found for deuterium substitution. The origin of the observed miscibility Isotope Effect has been qualitatively discussed in terms of the condensed-phase Isotope Effect theory.

Agnieszka Siporska - One of the best experts on this subject based on the ideXlab platform.

  • 18o 16o Isotope Effect on miscibility of isobutyric acid with water
    Journal of Physical Chemistry B, 2007
    Co-Authors: Agnieszka Siporska, And Anna Makowska, Jerzy Szydlowski
    Abstract:

    The miscibility of isobutyric acid with water and the influence of the Isotope substitution of oxygen (16O/18O) in water over a broad concentration range are reported. The system exhibits a phase diagram with an upper critical solution temperature (UCST) and a visible Isotope Effect thereon. The oxygen Isotope substitution decreases the UCST, leading to better miscibility of isobutyric acid with water. The Isotope shift, ΔTc = Tc(18O) − Tc(16O), extrapolated to the 100% enrichment in 18O, is equal to −1.15 K; hence it is much smaller and opposite to that found for deuterium substitution. The origin of the observed miscibility Isotope Effect has been qualitatively discussed in terms of the condensed-phase Isotope Effect theory.

  • 18O/16O Isotope Effect on Miscibility of Isobutyric Acid with Water
    Journal of Physical Chemistry B, 2007
    Co-Authors: Agnieszka Siporska, And Anna Makowska, Jerzy Szydłowski
    Abstract:

    The miscibility of isobutyric acid with water and the influence of the Isotope substitution of oxygen (16O/18O) in water over a broad concentration range are reported. The system exhibits a phase diagram with an upper critical solution temperature (UCST) and a visible Isotope Effect thereon. The oxygen Isotope substitution decreases the UCST, leading to better miscibility of isobutyric acid with water. The Isotope shift, ΔTc = Tc(18O) − Tc(16O), extrapolated to the 100% enrichment in 18O, is equal to −1.15 K; hence it is much smaller and opposite to that found for deuterium substitution. The origin of the observed miscibility Isotope Effect has been qualitatively discussed in terms of the condensed-phase Isotope Effect theory.

A L Buchachenko - One of the best experts on this subject based on the ideXlab platform.

  • magnetic Isotope Effect nuclear spin control of chemical reactions
    Journal of Physical Chemistry A, 2001
    Co-Authors: A L Buchachenko
    Abstract:

    Molecular transformation (chemical reaction) as an electron−nuclear rearrangement of the reactants into the products is the heart of chemistry, the central event which all chemistry circulates about. It is selective to the nuclei, both in mass and spin. Nuclear mass selectivity of reactions results in classical Isotope Effect (CIE), the remarkable phenomenon which continues to play a unique role and has served served for many years as a powerful and reliable tool of mechanistic chemistry and biochemistry. Another breakthrough of similar scale and importance is the discovery of nuclear spin selectivity of chemical reactions, which is the dependence of the reaction rates on the nuclear spin and nuclear magnetic moment of the reactants. In contrast to CIE, which is governed by chemical energy of the starting and transition states of reactant molecules, this new Isotope Effect is controlled by magnetic interactions, so it was christened the magnetic Isotope Effect (MIE). The general principles of tuning of th...

And Anna Makowska - One of the best experts on this subject based on the ideXlab platform.

  • 18o 16o Isotope Effect on miscibility of isobutyric acid with water
    Journal of Physical Chemistry B, 2007
    Co-Authors: Agnieszka Siporska, And Anna Makowska, Jerzy Szydlowski
    Abstract:

    The miscibility of isobutyric acid with water and the influence of the Isotope substitution of oxygen (16O/18O) in water over a broad concentration range are reported. The system exhibits a phase diagram with an upper critical solution temperature (UCST) and a visible Isotope Effect thereon. The oxygen Isotope substitution decreases the UCST, leading to better miscibility of isobutyric acid with water. The Isotope shift, ΔTc = Tc(18O) − Tc(16O), extrapolated to the 100% enrichment in 18O, is equal to −1.15 K; hence it is much smaller and opposite to that found for deuterium substitution. The origin of the observed miscibility Isotope Effect has been qualitatively discussed in terms of the condensed-phase Isotope Effect theory.

  • 18O/16O Isotope Effect on Miscibility of Isobutyric Acid with Water
    Journal of Physical Chemistry B, 2007
    Co-Authors: Agnieszka Siporska, And Anna Makowska, Jerzy Szydłowski
    Abstract:

    The miscibility of isobutyric acid with water and the influence of the Isotope substitution of oxygen (16O/18O) in water over a broad concentration range are reported. The system exhibits a phase diagram with an upper critical solution temperature (UCST) and a visible Isotope Effect thereon. The oxygen Isotope substitution decreases the UCST, leading to better miscibility of isobutyric acid with water. The Isotope shift, ΔTc = Tc(18O) − Tc(16O), extrapolated to the 100% enrichment in 18O, is equal to −1.15 K; hence it is much smaller and opposite to that found for deuterium substitution. The origin of the observed miscibility Isotope Effect has been qualitatively discussed in terms of the condensed-phase Isotope Effect theory.

Paul C. Canfield - One of the best experts on this subject based on the ideXlab platform.

  • Boron Isotope Effect in single crystals of superconductor
    Philosophical Magazine, 2013
    Co-Authors: Halyna Hodovanets, Sheng Ran, Paul C. Canfield, Sergey L. Bud’ko
    Abstract:

    Abstract The influence of local moment magnetism on the boron Isotope Effect of was studied on single crystals of . Values of the partial Isotope Effect exponent of and were obtained based on two different criteria applied to extract . No significant change in the partial Isotope Effect exponent compared to the ones obtained for was observed. Based on this result, we conclude that pair-breaking due to the Er local magnetic moment appears to have no detectable influence on boron Isotope Effect of .

  • boron Isotope Effect in superconducting mgb2
    Physical Review Letters, 2001
    Co-Authors: S L Budko, G Lapertot, C Petrovic, C E Cunningham, N E Anderson, Paul C. Canfield
    Abstract:

    We report the preparation method of and boron Isotope Effect for MgB2, a new binary intermetallic superconductor with a remarkably high superconducting transition temperature T(c)(10B) = 40.2 K. Measurements of both temperature dependent magnetization and specific heat reveal a 1.0 K shift in T(c) between Mg11B2 and Mg10B2. Whereas such a high transition temperature might imply exotic coupling mechanisms, the boron Isotope Effect in MgB2 is consistent with the material being a phonon-mediated BCS superconductor.