The Experts below are selected from a list of 117 Experts worldwide ranked by ideXlab platform
A. N. Sonar - One of the best experts on this subject based on the ideXlab platform.
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Studies the acoustic properties of substituted heterocyclic compound in dioxane-water mixture.
Indian journal of applied research, 2015Co-Authors: A. N. SonarAbstract:Acoustical properties have been measured for substituted heterocyclic compounds in dioxane-water mixture at 303K. The measurement have been perform to evaluate acoustical parameter such as adiabatic compressibility (bs), Partial Molal Volume (f v ), intermolecular free length (L f ), apparent Molal compressibility (f k ), specific acoustic impedance (Z), relative association (R A ), salvation number (Sn).
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ULTRASONIC STUDIES ON MOLECULAR INTERACTION OF SUBSTITUTED HETEROCYCLIC COMPOUNDS IN ACETONE-WATER MIXTURE AT 303K
2011Co-Authors: A. N. Sonar, N. S. PawarAbstract:Acoustical and Volumetric properties have been measured for substituted heterocyclic compounds drugs and compounds in acetone-water mixture at 303K. The measurement have been perform to evaluate acoustical parameters such as adiabatic compressibility (βs ), Partial Molal Volume (φ v ), intermolecular free length (L f ), apparent Molal compressibility (φ κ ), specific acoustic impedance (Z), relative association (R A ), salvation number (Sn). Key word: - Ultrasonic velocity, adiabatic compressibility, apparent Molal Volume.
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Acoustic and Volumetric Properties of Digoxin and Thiabendazole in 1, 4 Dioxane at 303 K
Hindawi Limited, 2010Co-Authors: A. N. Sonar, N. S. PawarAbstract:Acoustical and Volumetric properties have been measured for substituted heterocyclic compounds digoxin and thiabendazole in 1, 4 dioxane at 303 K. The ultrasonic velocity measurement have been performed to evaluate acoustical parameter such as adiabatic compressibility (βs), Partial Molal Volume (ɸv), intermolecular free length (Lf), apparent Molal compressibility (ɸk), specific acoustic impedance (Z), relative association (RA), salvation number (Sn), limiting apparent Molal compressibility (ɸ0k), limiting apparent Molal Volume(ɸ0v) and their constant (Sk,Sv). The viscosity coefficient (A, B) was evaluated by using john–dole equation. These parameters throw the light on the solute-solvent interaction and solute-solute interaction
Imran Khan - One of the best experts on this subject based on the ideXlab platform.
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Effect of temperature on Volumetric and isentropic compressibility of glycine in aqueous KCl/NaCl solutions
Journal of Molecular Liquids, 2010Co-Authors: Riyazuddeen, Imran KhanAbstract:Abstract Density ( ρ ) and ultrasonic velocity ( u ) values of glycine in 1.0 M aqueous KCl and 1.0 M aqueous NaCl solutions have been measured as a function of amino acids concentration at T = (298.15, 303.15, 308.15, 313.15, 318.15 and 323.15) K. Using the ρ and u data, the thermodynamic parameters such as Partial Molal Volume ( ϕ 0 v ), isentropic compressibility ( κ s ), change in isentropic compressibility (Δ κ s ), relative change (Δ κ s / κ 0 ) in isentropic compressibility and Partial Molal isentropic compressibility ( ϕ 0 k ), values have been computed. The increase in Partial Molal Volume with temperature is attributed to the Volume expansion of hydrated zwitterions. The ϕ 0 v and ϕ 0 k values of glycine in 1.0 M aqueous KCl and NaCl solutions are larger than the corresponding values in water. The larger Partial Molal Volumes of glycine in 1.0 M aqueous KCl and NaCl is ascribed to the formation of ‘zwitterion–K + /Na + /Cl − ’ and ‘K + /Na + /Cl − –water dipole’ aggregates in solutions. The variation of κ s, Δ κ s and Δ κ s /κ 0 with amino acid/zwitterions concentration and temperature is discussed in terms of zwitterions–ions, zwitterions–water dipoles, ion–ion, ion–water dipoles due to intermolecular/interionic interactions occurring in the systems.
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Effect of KCl and KNO 3 on Partial Molal Volumes and Partial Molal Compressibilities of Some Amino Acids at Different Temperatures
International Journal of Thermophysics, 2008Co-Authors: Riyazuddeen, Imran KhanAbstract:Density (ρ) and ultrasonic velocity (u) values of amino acids l-alanine, l-proline, l-valine, and l-leucine in 2M aqueous KCl and 2M aqueous KNO3 solutions have been measured as a function of amino acid concentration at different temperatures (298.15 K, 303.15 K, 308.15 K, 313.15 K, 318.15 K, and 323.15 K). Using the ρ and u data, Partial Molal Volume (\({\phi_{\rm v}^{\rm o}}\)) and Partial Molal isentropic compressibility (\({\phi_{\rm k}^{\rm o} }\)) values have been computed. The increase in Partial Molal Volume with temperature has been attributed to the Volume expansion of hydrated zwitterions. The \({\phi_{\rm v}^{\rm o}}\) and \({\phi_{\rm k}^{\rm o}}\) values of l-alanine, l-proline, l-valine, and l-leucine in 2M aqueous KCl and KNO3 solutions have been found to be larger than the corresponding values in water. The larger Partial Molal Volumes of l-alanine, l-proline, l-valine, and l-leucine in 2M aqueous KCl and KNO3 solutions have been ascribed to the formation of ‘zwitterion-K+/Cl−/NO 3 − ’ and ‘K+/Cl−/NO 3 − –water dipole’ aggregates in solutions. The formation of these entities in solutions causes the release of water associated with zwitterions to the bulk water. The larger Partial Molal compressibilities of l-alanine-/l-proline-/l-valine-/l-leucine–2M aqueous KCl/KNO3 solutions than the corresponding values in water have been attributed to the formation of ‘zwitterion–ion’ and ‘ion–water dipole’ incompressible entities in solutions.
Muhammad Asghar Jamal - One of the best experts on this subject based on the ideXlab platform.
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Acoustical studies of pharmaceutical excipients in binary solvent mixtures
Journal of Molecular Liquids, 2016Co-Authors: Bushra Naseem, Mahreen Khan, Muhammad Asghar JamalAbstract:Abstract Pharmaceutical excipients have gained a great importance due to their control of blood glucose level and sugar alternative. Thermodynamic methods provide an easy way for determination of solute-solute and solute-solvent interactions in solutions. Density and sound velocity for sugar alcohols have been measured in binary mixtures of Dimethyl Sulfoxide-Water at different percentage compositions (i.e. 10%–50%) at different temperatures. Density and sound velocity data have been used to calculate apparent Molal Volume, apparent Molal isentropic compressibility, Partial Molal Volume, Partial Molal isentropic compressibility, intermolecular free length, relative association, Rao's molar sound function and solvation number. Results have been discussed in terms of solvent-solvent, solute-solute and solvent-solute interactions. For all the systems studied, the density, sound velocity and apparent Molal Volume increase with increasing concentration of sugar alcohols which indicates the presence of solute-solvent interactions. The value of Partial Molal Volume also increases with increasing temperature. The values of Sv are found positive while the values of apparent Molal isentropic compressibility are negative which indicates the presence of solute-solvent interactions.
Fleming Martínez - One of the best experts on this subject based on the ideXlab platform.
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Comments on “Assorted interactions of amino acids prevailing in aqueous vitamin C solutions probed by physicochemical and ab-initio contrivances”
Chemical Physics Letters, 2020Co-Authors: William E. Acree, Fleming MartínezAbstract:Abstract A polemic is given regarding several of the calculated numerical values given in the published paper. The authors’ calculated apparent Molal Volumes for tryptophan and tyrosine dissolved in aqueous-ascorbic acid solutions cannot be obtained from the experimental density data and amino acid Molalities given in the published paper. Moreover, the authors’ calculations show tyrosine to have the larger apparent Partial Molal Volume, which is just opposite to what has been reported in the published literature.
S. M. Toy - One of the best experts on this subject based on the ideXlab platform.
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Stress-induced hydrogen movement and the Partial Molal Volume of hydrogen in AISI 4340 steel
Journal of Materials Science, 1999Co-Authors: S. M. ToyAbstract:Stress-induced movement of hydrogen to the high tensile region in AISI 4340 steel was measured at room temperature and 202 °C. A neodymium hydrogen detection method was used to determine the location and concentration of hydrogen. The AISI 4340 stress rings with local hydrogen content up to 0.69 ppm and loaded to 16.87, × 103 kg cm-2 did not fail, whereas a stress ring with 0.73 ppm did fail for the test condition cited. The predicted hydrogen concentration versus fracture time curves at constant tensile stress indicated a good agreement with the stress ring test data. The Partial Molal Volume of hydrogen, υ¯H, was calculated to be 2.47 cm3 per g-atom for AISI 4340 steel, which was greater than the reported value for alpha iron at 2.0 cm3 per g-atom. Knowing the value υ¯H and the hydrogen content for equation RT In Cσ/Co = υ¯Hσ/3 the increase of hydrogen concentration by a given applied stress can be calculated.