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Abstract  

The extraction of Co2+ from aqueous 0.1M acetate buffer by thenoyltrifluoroacetone (HTTA) and 8-hydroxyquinoline (HQ) and by a mixture of HTTA+phen and HQ+phen in benzene has been studied at various temperatures allowing for elucidation of the thermodynamics of extraction in the cases investigated.

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is determined. The thermodynamics of the reaction of formation in water at different temperatures are investigated, and fundamental parameters are obtained on the basis of reaction thermodynamic and thermokinetic equations

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Abstract  

The aim of this investigation was to study the influence of electrolytes on a reaction of triiodide complex formation. Investigation of the salt effect as concerns the thermodynamics of I 3 formation in methanol, ethanol and n-propanol solutions revealed regularities of the influence of the electrolyte on triiodide complex formation connected with a multifactorial effect of the ionic medium. The quasichemical model presented was used to calculate parameters reflecting the overall salt effect.

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Abstract  

Contributions of modern, temperature-modulated calorimetry are qualitatively and quantitatively discussed. The limitations are summarized, and it is shown that their understanding leads to new advances in instrumentation and measurement. The new thermal analysis experiments allow to separate reversing from irreversible processes. This opens the irreversible states and transitions to a description in terms of equilibrium and irreversible thermodynamics. Amorphous systems can be treated frommacroscopic to nanometer sizes with weak to strong coupling between neighboring phases. Semicrystalline, macromolecular systems are understood on the basis of modulated calorimetry as globally metastable, micro-to-nanophase-separated systems with locally reversible transitions.

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Abstract  

A novel sorbent resin consisting of a Phosphonic Acid grafted on Merrifield Resin (PA-MR) for the extraction of uranyl from nitrate media is described. The sorption behaviour of uranyl cation on PA-MR was investigated using batch equilibrium technique. The effects of parameters such as shaking speed, pH levels, contact time, metal concentrations, ionic strength and temperature were reported. The results show that the sorption capacity increases with increasing both initial uranyl ion concentration and temperature and decreases with increasing ionic strength. Therefore, the optimum condition for the present study should be using 6.6 mg adsorbent per 1.0 mg uranyl in solution with pH 3.6 and shaking at 250 rpm for 180 min. The adsorption behavior of the system was also investigated and found to be in line with Langmuir isotherm. The kinetic data was well described by the pseudo second-order. Thermodynamics data leads to endothermic process ∆H = + 31.03 kJ−1 mol−1, ∆S = + 146.64 J mol−1 K−1 and ∆G = −11.96 kJ mol−1 at 20 K. ∆G decreased to negatives values with increasing temperature indicating that the process was more favoured at high temperature.

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Abstract  

In order to understand the mobility of uranium it is very important to know about its sorption kinetics and the thermodynamics behind the sorption process on soil. In the present study the sorption kinetics of uranium was studied in soil and the influence parameters to the sorption process, such as initial uranium concentration, pH, contact time and temperature were investigated. Distribution coefficient of uranium on soil was measured by laboratory batch method. Experimental isotherms evaluated from the distribution coefficients were fit to Langmuir, Freundlich and Dubinin–Radushkevich (D–R) models. The sorption energy for uranium from the D–R adsorption isotherm was calculated to be 7.07 kJ mol−1.The values of ΔH and ΔS were calculated to be 37.33 kJ mol−1 and 162 J K−1 mol−1, respectively. ΔG at 30 °C was estimated to be −11.76 kJ mol−1. From sorption kinetics of uranium the reaction rate was calculated to be 1.6 × 10−3 min−1.

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Abstract  

As represented by equations in which there is a term representing the biomass, the thermodynamics of biological growth processes is difficult to study without knowing the thermodynamic properties of cellular structural fabric. Measurement of the heat capacity data required to determine the standard entropy, S 298,15 or the standard absorbed heat, (H 298,15 -ΔH 0 298,15 of biomass requires a low-temperature calorimter, and these are not present in most laboratories. Based on a previously described method for entropy, two equations are developed that enable values of the absorbed heat (Θ 298,15) and the absorbed heat of formation, (Δ f Θ 298,15) for biomass to be calculated empirically which are accurate to within 1% with respect to the biomass substances tested. These equations depend on a previous knowledge of the atomic composition or the unit-carbon formulas of macromolecules or structural cellular fabric.

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different pH (data taken from [ 4 ]) Even if the model is able to explain experimental observations, it should be explicitly pointed out here that the real thermodynamics could be more complicated than the one considered

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2 O with controlled morphologies via solid-state reaction at low heat [ 20 , 21 ] and to study the kinetics and thermodynamics of the decomposition of MnV 2 O 6 ·4H 2 O using DSC technique. Non-isothermal kinetics of the decomposition process of MnV

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enthalpies of solution are known and the thermodynamics of the solutions have rarely been reported. In this article, the thermochemical properties including Δ sol H m , Δ sol G m , Δ sol S m , Δ sol S m (app), Δ sol S m (partial) of resveratrol

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