scholarly journals Synthesis and Evaluation of Thermodynamic Solubility of Triazolo Quinolone Class Derivatives in Various Solvents at 298.15-328.15 K

2020 ◽  
Vol 84 ◽  
pp. 11-22
Author(s):  
Shipra Baluja ◽  
Mona Pithiya ◽  
Asmita Hirapara ◽  
Divyata Lava
Keyword(s):  
Free Energy ◽  
Ethyl Acetate ◽  
Thermodynamic Parameters ◽  
Empirical Equations ◽  
Dissolution Enthalpy ◽  
Entropy Of Mixing ◽  
Gibb’S Free Energy ◽  
Semi Empirical

The solubility of triazolo quinolone class derivatives in methanol, ethanol, n-propanol, n-butanol and ethyl acetate was measured using a gravimetrical method at temperature ranging from 298.15 K to 328.15 K. The results of these measurements were correlated with semi empirical equations. Some thermodynamic parameters such as dissolution enthalpy, Gibb’s free energy and entropy of mixing have also been calculated.

scholarly journals Solubility of Ilaprazole in Various Alcohols in Temperature Range between (298.15 to 322.15) K

2015 ◽  
Vol 51 ◽  
pp. 155-159
Author(s):  
Shipra Baluja ◽  
Kapil Bhesaniya
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Empirical Equation ◽  
Dissolution Enthalpy ◽  
Temperature Range ◽  
Entropy Of Mixing ◽  
Gibb’S Free Energy ◽  
Semi Empirical

The solubility of Ilaprazole in methanol, ethanol, 2-propanol and n-butanol was measured using a gravimetrical method at temperature ranging from 298.15 K to 322.15 K. The results of these measurements were correlated with a semi empirical equation. Some thermodynamic parameters such as dissolution enthalpy, Gibb’s free energy, and entropy of mixing have also been calculated.

First and second laws of thermodynamics: relationship, “inconsistency”, hidden effects

2020 ◽  
pp. 63-73
Author(s):  
A. M. Savchenko ◽  
Yu. V. Konovalov ◽  
A. V. Laushkin
Keyword(s):  
Free Energy ◽  
Internal Energy ◽  
Second Law Of Thermodynamics ◽  
Second Law ◽  
Entropy Of Mixing ◽  
Ideal Mixing ◽  
Laws Of Thermodynamics ◽  
Relationship Of ◽  
The Relationship

The relationship of the first and second laws of thermodynamics based on their energy nature is considered. It is noted that the processes described by the second law of thermodynamics often take place hidden within the system, which makes it difficult to detect them. Nevertheless, even with ideal mixing, an increase in the internal energy of the system occurs, numerically equal to an increase in free energy. The largest contribution to the change in the value of free energy is made by the entropy of mixing, which has energy significance. The entropy of mixing can do the job, which is confirmed in particular by osmotic processes.

scholarly journals Reaeration and oxygen dissipation into a circular hydraulic channel: experimental and dimensionless approach

RBRH ◽  
2018 ◽  
Vol 23 (0) ◽  
Author(s):  
Felipe Keiji Feital Harano ◽  
Murilo de Souza Ferreira ◽  
Marcos Vinícius Mateus ◽  
Deusmaque Carneiro Ferreira ◽  
Julio Cesar de Souza Inácio Gonçalves
Keyword(s):  
Interfacial Phenomena ◽  
Linear Regression Method ◽  
Hydraulic Parameters ◽  
Empirical Equations ◽  
Hydraulic Conditions ◽  
Do Concentration ◽  
Hydraulic Channel ◽  
M Estimates ◽  
Semi Empirical ◽  
Key Parameter

ABSTRACT Dissolved oxygen (DO) is a key parameter in water quality. The DO concentration in a water body can be changed by interfacial phenomena such as reaeration and oxygen dissipation, which can be represented by the coefficients K2 and KD, respectively. Few studies have jointly correlated K2 and KD with physical and hydraulic parameters of the channel. The present work investigated the behavior of these coefficients over a range of hydraulic conditions, and developed semi-empirical equations capable of relating both coefficients. Reaeration and DO dissipation tests were conducted in a circular hydraulic channel with flow velocity ranging from 0.20 to 0.79 m.s-1 and depth ranging from 0.09 to 0.15 m. Estimates of K2 and KD were performed using the non-linear regression method. Semi-empirical equations were obtained based on classical dimensional analysis and multiple regression analysis. The comparison between measured and estimated coefficients yielded R2 for reaeration and dissipation of 0.940 and 0.844, respectively. KD was higher than K2 for all turbulence levels applied at the hydraulic channel. An estimate obtained by the relation between the semi-empirical equations indicates that the transfer of oxygen in the water-air direction (dissipation) is approximately twice as fast as the transfer in the air-water direction (reaeration).

scholarly journals Study on Adsorption of Cu and Ba from Aqueous Solutions Using Nanoparticles of Origanum (OR) and Lavandula (LV)

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Ghadah M. Al-Senani ◽  
Foziah F. Al-Fawzan
Keyword(s):  
Heavy Metals ◽  
Particle Size ◽  
Free Energy ◽  
Aqueous Solutions ◽  
Thermodynamic Parameters ◽  
Solution Ph ◽  
Environment Friendly ◽  
Removal Of Heavy Metals ◽  
Equilibrium Data ◽  
Langmuir And Freundlich Models

Wild herbs (Origanum (OR) and Lavandula (LV)) were used as environment-friendly adsorbents in this study. The adsorbents were used for adsorption of Cu and Ba from water. The adsorption of heavy metals onto OR and LV was dependent on particle size, dose, and solution pH. The diameter of adsorbent particles was less than 282.8 nm. The adsorption follows second-order kinetics. Langmuir and Freundlich models have been applied to describe the equilibrium data, and the thermodynamic parameters, the Gibbs free energy, ∆G°, enthalpy, ∆H°, and entropy, ∆S°, have been determined. The positive value of ∆H° suggests that the adsorption of heavy metals by the wild herbs is endothermic. The negative values of ∆G° at all the studied temperatures indicate that the adsorption is a spontaneous process. It can be concluded that OR and LV are promising adsorbents for the removal of heavy metals from aqueous solutions over a range of concentrations.

scholarly journals Thermodynamic Parameters of PbTe Crystals: DFT-Calculations

2015 ◽  
Vol 16 (1) ◽  
pp. 28-33
Author(s):  
D. M. Freik ◽  
B. P. Volochanska ◽  
T. O. Parashchuk
Keyword(s):  
Density Functional Theory ◽  
Free Energy ◽  
Electronic Structure ◽  
Thermodynamic Parameters ◽  
Quantum Chemical ◽  
Density Functional ◽  
Cubic Phase ◽  
Functional Theory ◽  
Temperature Dependences ◽  
Analytical Expressions

Based on the analysis of the crystal NaCl type and electronic structure of cubic phase CdS crystals the cluster models have been built for calculation of the geometric and thermodynamic parameters. According to density functional theory (DFT) and using the hybrid valence base set B3LYP the temperature dependence of the energy ΔE and the enthalpy ΔH of formation, Gibbs free energy ΔG, entropy ΔS, specific heat at constant volume CV and pressure CP of the crystals have been found. The analytical expressions of the temperature dependences of presented thermodynamic parameters which was approximated from the quantum- chemical calculations data and with using mathematical package Maple 14 have been received.

scholarly journals STUDY OF PARAMETERS OF REACTIVITY MOLECULAR IN ADDITION REACTIONS OF HYDROHALIC ACIDS WITH ETHYLENE

2011 ◽  
Vol 08 (15) ◽  
pp. 54-64
Author(s):  
Francisco José Santos LIMA ◽  
Ademir Oliveira da SILVA ◽  
Yuri Lima de BRITO ◽  
Fernanda Louise Cardoso de SOUSA
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Electrostatic Potential ◽  
Molecular Modelling ◽  
Quantitative Data ◽  
Addition Reactions ◽  
Partial Charge ◽  
Kinetic Behavior ◽  
Atomic Properties ◽  
Molecular Reactivity

The molecular reactivity parameters (PRM´s) have been used to quantify atomic properties that influence in the interactions among the molecules. It is possible throughout the analysis of its magnitudes and stereochemistry arrangement of the system, to foresee and/or to explain certain experimental events. The aim of this work was to establish parallel among the thermodynamic parameters (enthalpy, entropy and free energy), and the results of the simulations of theoretical molecular modelling through the geometric qualitative and semi-quantitative data (densities of coulomb of electrostatic potential and partial charge), generated by a commercial software (WebLab ViewerPro) for the obtaining of PRM´s, in the hydrohalic acids reactions with the ethylene. It can be notice that there is clearly dependence of the reactivity parameters with the thermodynamic and kinetic behavior of these reactions.

scholarly journals Study of Spectroscopy and Thermodynamic Properties for Phoshours dioxide PO2 Molecular and Influence Study of Bond ( P-O ) on Spectroscopy Properties

2012 ◽  
Vol 9 (4) ◽  
pp. 616-622
Author(s):  
Baghdad Science Journal
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Room Temperature ◽  
Formation Enthalpy ◽  
Heat Of Formation ◽  
Vibration Modes ◽  
Equilibrium Distance ◽  
Atmosphere Pressure ◽  
Gibb’S Free Energy ◽  
Good Agreement

In This research a Spectroscopic complement and Thermodynamic properties for molecule PO2 were studied . That included a calculation of potential energy . From the curve of total energy for molecule at equilibrium distance , for bond (P-O), the degenerated of bond energy was (4.332eV) instate of the vibration modes of ( PO2 ) molecule and frequency that was found active in IR spectra because variable inpolarization and dipole moment for molecule. Also we calculate some thermodynamic parameters of ( PO2 ) such as heat of formation , enthalpy , heat Of capacity , entropy and gibb's free energy Were ( -54.16 kcal/mol , 2366.45 kcal/mol , 10.06 kcal /k/mol , 59.52 kcal /k /mol, -15370.51 kcal / mol ) respectively under condition of room temperature and atmosphere pressure ( 298 k , 1 atm.). We calculate there parameters at various temperature from ( 100 – 3000 ) K . It was found that the obtainded results were in a good agreement with previous experimental facts.

Absorption Equilibrium and Thermodynamics of Fenugreek Yellow Pigment on Macroporous Resins

2011 ◽  
Vol 233-235 ◽  
pp. 91-94
Author(s):  
Feng Han ◽  
Wen Hong Li ◽  
Xuan Tang ◽  
Dong Li
Keyword(s):  
Free Energy ◽  
Thermodynamic Parameters ◽  
Gibbs Free Energy ◽  
Adsorption Equilibrium ◽  
Yellow Pigment ◽  
Adsorption Models ◽  
Freundlich Model ◽  
Langmuir Adsorption ◽  
Macroporous Resins ◽  
Equilibrium Data

The adsorption equilibrium and thermodynamics of pigment extracted from Fenugreek after degumming on macroporous resins was investigated under differentinitial concentrations. The suitability of the Freundlich and Langmuir adsorption models to the equilibrium data was investigated. The model fitness was determined by R2 . Thermodynamic parameters were calculated by the Van’t Hof equation.The results showed that Freundlich model gave a better fit of adsorption isotherms than Langmuir models. The positive value of enthalpy(∆H) indicated that the adsorption was endothermic, the negative value of Gibbs free energy (∆G) showed the spontaneous and favoured nature of adsorption, and the entropy(∆S) was positive.The resins LS-46 showed an effective adsorbtion for Fenugreek yellow pigment.

Development of a Mathematical Model for Performance Prediction of Planing Catamaran in Calm Water

2019 ◽  
Vol 161 (A2) ◽  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Performance Prediction ◽  
Data Evaluation ◽  
Empirical Equations ◽  
Calm Water ◽  
Semi Empirical ◽  
The Mathematical Model ◽  
Comparison With Experimental Data

In this paper, an attempt has been made to predict the performance of a planing catamaran using a mathematical model. Catamarans subjected to a common hydrodynamic lift, have an extra lift between the two asymmetric half bodies. In order to develop a mathematical model for performance prediction of planing catamarans, existing formulas for hydrodynamic lift calculation must be modified. Existing empirical and semi-empirical equations in the literature have been implemented and compared against available experimental data. Evaluation of lift in comparison with experimental data has been documented. Parameters influencing the interaction between demi-hulls and separation effects have been analyzed. The mathematical model for planing catamarans has been developed based on Savitsky’s method and results have been compared against experimental data. Finally, the effects of variation in hull geometry such as deadrise angle and distance between two half bodies on equilibrium trim angle, resistance and wetted surface have been examined.

DIFFUSION IN MULTICOMPONENT METALLIC SYSTEMS: VI. SOME THERMODYNAMIC PROPERTIES OF THE D MATRIX AND THE CORRESPONDING SOLUTIONS OF THE DIFFUSION EQUATIONS

1963 ◽  
Vol 41 (12) ◽  
pp. 2166-2173 ◽  
Author(s):  
J. S. Kirkaldy ◽  
D. Weichert ◽  
Zia-Ul- Haq
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Stability Condition ◽  
Stable Solution ◽  
Positive Definite ◽  
Diffusion Equations ◽  
Second Law ◽  
Isothermal Diffusion ◽  
Gibb’S Free Energy ◽  
The Stability

The second law requirement that the Onsager L matrix for isothermal diffusion in a stable solution be positive definite and the stability condition for such a solution that the Hessian of the Gibb's free energy be positive definite impose on the diffusion D matrix the condition that it always have real and positive eigenvalues. This condition ensures that solutions of the differential equations for diffusion will always relax in a nonperiodic way.

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