scholarly journals The evaluation of kinetic parameters for cadmium doped Co-Zn ferrite using thermogravimetric analysis

2019 ◽  
Vol 30 (1) ◽  
pp. 60-64 ◽  
Author(s):  
Akshay B. Kulkarni ◽  
Shridhar N. Mathad ◽  
Raghavendra P. Bakale
Keyword(s):  
Kinetic Parameters ◽  
Zinc Ferrite ◽  
Frequency Factor ◽  
Entropy Change ◽  
Solid State Reaction Method ◽  
Enthalpy Change ◽  
Ferrite Sample ◽  
Zn Ferrite ◽  
Cobalt Zinc Ferrite ◽  
Evaluation Of Kinetic Parameters

AbstractThis work had the objective to analyze the thermodynamic properties of cadmium doped cobalt zinc ferrite (Co0.5Zn0.5Cd0.3Fe1.8O4), obtained by solid state reaction method and characterized by TGA-DTA. The TG analysis show sharp peaks at four points, two for water reduction, one for decomposition of chlorides and last one for formation of end product. The ratio of weight of end product to starting material match with ratio of molecular weight of end product and starting materials; this confirms the formation of ferrite sample. Broido, Coats-Redfern, Chang and Horowitz-Metzger approximations are employed to compute the activation energy (Ea) of formation of ferrite sample. The kinetic parameters like frequency factor (A), entropy change (ΔS), enthalpy change (ΔH) and changes in internal energy (ΔG) of sample are also reported.

scholarly journals Effect of Substitutions on Thermal Behavior of Symmetric Doubleschiff Bases of 1,1’-Bis(4-Amino Phenyl)Cyclohexane

2016 ◽  
Vol 63 ◽  
pp. 145-149
Author(s):  
Bhavesh J. Gangani ◽  
Parsotam H. Parsania
Keyword(s):  
Thermal Properties ◽  
Thermal Behavior ◽  
Kinetic Parameters ◽  
Schiff Bases ◽  
Frequency Factor ◽  
Entropy Change ◽  
Nitrogen Atmosphere ◽  
Energy Of Activation ◽  
Thermo Gravimetric ◽  
Degradation Kinetic

Thermo gravimetric analyses of some symmetric double Schiff bases of 1, 1’- bis (4-amino phenyl) cyclohexane (SDSB-1 to SDSB-6) was carried out at 100C/min in nitrogen atmosphere. Schiff bases are thermally stable up to 200-285°C and followed two step degradation kinetic. Various kinetic parameters such as order of degradation (n), energy of activation (Ea), frequency factor (A) and entropy change (ΔS) were derived accordingly Anderson-Freeman method interpreted in light of nature of the substituents. The nature, size and position of substituents affected thermal properties of the Schiff bases.

scholarly journals Study of Non-Isothermal Decomposition and Kinetic Analysis of 2,4-Dihydroxybenzoic Acid- Melamine-Formaldehyde Copolymer

2010 ◽  
Vol 7 (3) ◽  
pp. 1101-1107 ◽  
Author(s):  
S. S. Butoliya ◽  
W. B. Gurnule ◽  
A. B. Zade
Keyword(s):  
Kinetic Parameters ◽  
Average Molecular Weight ◽  
Acid Catalyst ◽  
Conductometric Titration ◽  
Frequency Factor ◽  
Entropy Change ◽  
Dihydroxybenzoic Acid ◽  
H Nmr ◽  
Uv Visible

A copolymer (2,4-DHBAMF) synthesized by the condensation of 2,4-dihydroxybenzoic acid and melamine with formaldehyde in the presence of acid catalyst using varied molar proportions of the reactants. A composition of the copolymer has been determined by elemental analysis. The number average molecular weight has been determined by conductometric titration in non-aqueous medium. The copolymer has been characterized by UV-Visible, IR and1H NMR spectral analysis. Thermogravimetric analysis was carried out to study the decomposition and various kinetic parameters. Freeman Carroll and Sharp Wentworth methods have been applied for the calculation of kinetic parameters while the data from Freeman Carroll method have been used to determine various thermodynamic parameters such as order of reaction, energy of activation, frequency factor, entropy change, free energy change and apparent entropy change. The results indicate that given copolymer have potential as matrix resin for long term applications at temperature up to 350°C.

scholarly journals Thermal Analysis of some Imidazolinone Derivatives

2015 ◽  
Vol 44 ◽  
pp. 124-129
Author(s):  
Shipra Baluja ◽  
Nikunj Kachhadia
Keyword(s):  
Thermal Stability ◽  
Thermal Analysis ◽  
Kinetic Parameters ◽  
Frequency Factor ◽  
Entropy Change ◽  
Energy Of Activation ◽  
Thermal Stability Of

Thermal analysis of some imidazolinone derivatives derived from 1, N-phenyl-3-p-nitrophenyl-4-formyl pyrazole, have been carried out by TGA technique. From these thermograms, various kinetic parameters such as order of degradation (n), energy of activation (E), frequency factor (A) and entropy change (∆S) have been evaluated. Further, thermal stability of imidazolinone derivatives have been determined, which is found to depend on the type of substituent present in the compounds.

scholarly journals Determination of Kinetic Parameters of Decomposition of Tetrahydropyrimidine Derivatives

2013 ◽  
Vol 18 ◽  
pp. 23-32
Author(s):  
Kapil Bhesaniya ◽  
Ashish Patel ◽  
Shipra Baluja
Keyword(s):  
Thermal Analysis ◽  
Kinetic Parameters ◽  
Frequency Factor ◽  
Entropy Change ◽  
Structural Determination ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
Tga And Dsc ◽  
Thermal Stability Of

Some new tetrahydropyrimidine derivatives have been synthesized and their structural determination was done by IR, NMR and mass spectral data. Thermal analysis of these synthesized dihydropyrimidinthiones has been carried out by TGA and DSC techniques. From the thermograms, various kinetic parameters such as order of degradation (n), energy of activation (E), frequency factor (A) and entropy change (ΔS) have been evaluated. Further, thermal stability of tetrahydropyrimidine have been determined which is found to depend on the type of substituent present in the compounds.

Electrochemical studies and Thermodynamic Parameters of tris(2,2’-bipyridyl) ruthenium (II) in nonaqueous Solutions

2012 ◽  
Vol 1390 ◽  
Author(s):  
Gendensuren Bolormaa ◽  
Munkhbat Battulga ◽  
Batjargal Naranbileg ◽  
Baatar Battsengel ◽  
Chimed Ganzorig
Keyword(s):  
Kinetic Parameters ◽  
Thermodynamic Parameters ◽  
Redox Reaction ◽  
Standard Free Energy ◽  
Entropy Change ◽  
Electrode Reaction ◽  
Enthalpy Change ◽  
Experimental Conditions ◽  
Nonaqueous Solutions ◽  
Diffusion Controlled

ABSTRACTIn this study Ruthenium (II) tris (2, 2’-bipyridyl) complex in nonaqueous solution was studied by cyclic voltammetry and also its kinetic parameters were calculated. The redox reaction of ruthenium (II) trisbipyridyl complex is totally quasi-reversible and it can be described as a diffusion-controlled process. As a result of the redox reaction, the kinetic parameters of the electrode process such as diffusion coefficient (D), and heterogeneous rate constant (ks) were calculated. In addition, the different thermodynamic parameters such as standard free energy (ΔG#), enthalpy change (∆H#), and entropy change (∆S#) were determined and enthalpy change revealed the exothermic behavior of the electrode reaction. Both oxidation and reduction onset potentials of the ruthenium (II) trisbipyridyl complex was determined under the same experimental conditions to estimate the low ionization potential and electron affinity. The electrochemical and optical band gaps of the ruthenium (II) complex were compared.

Crystal structure and magnetic properties study on barium hexaferrite (BHF) and cobalt zinc ferrite (CZF) in composites

2021 ◽  
Vol 113 ◽  
pp. 106529
Author(s):  
Murli Kumar Manglam ◽  
Jyotirekha Mallick ◽  
Suman Kumari ◽  
Rabichandra Pandey ◽  
Manoranjan Kar
Keyword(s):  
Crystal Structure ◽  
Magnetic Properties ◽  
Zinc Ferrite ◽  
Barium Hexaferrite ◽  
Cobalt Zinc Ferrite

scholarly journals Thermodynamics of ligand binding by the yeast mRNA-capping enzyme reveals different modes of binding

2004 ◽  
Vol 384 (2) ◽  
pp. 411-420 ◽  
Author(s):  
Isabelle BOUGIE ◽  
Amélie PARENT ◽  
Martin BISAILLON
Keyword(s):  
Ligand Binding ◽  
Entropy Change ◽  
Enthalpy Change ◽  
Mrna Capping ◽  
Capping Enzyme ◽  
Eukaryotic Mrnas ◽  
Entropic Effect ◽  
A Minor ◽  
Rna Capping ◽  
Capping Enzymes

RNA-capping enzymes are involved in the synthesis of the cap structure found at the 5′-end of eukaryotic mRNAs. The present study reports a detailed study on the thermodynamic parameters involved in the interaction of an RNA-capping enzyme with its ligands. Analysis of the interaction of the Saccharomyces cerevisiae RNA-capping enzyme (Ceg1) with GTP, RNA and manganese ions revealed significant differences between the binding forces that drive the interaction of the enzyme with its RNA and GTP substrates. Our thermodynamic analyses indicate that the initial association of GTP with the Ceg1 protein is driven by a favourable enthalpy change (ΔH=−80.9 kJ/mol), but is also clearly associated with an unfavourable entropy change (TΔS=−62.9 kJ/mol). However, the interaction between Ceg1 and RNA revealed a completely different mode of binding, where binding to RNA is clearly dominated by a favourable entropic effect (TΔS=20.5 kJ/mol), with a minor contribution from a favourable enthalpy change (ΔH=−5.3 kJ/mol). Fluorescence spectroscopy also allowed us to evaluate the initial binding of GTP to such an enzyme, thereby separating the GTP binding step from the concomitant metal-dependent hydrolysis of GTP that results in the formation of a covalent GMP–protein intermediate. In addition to the determination of the energetics of ligand binding, our study leads to a better understanding of the molecular basis of substrate recognition by RNA-capping enzymes.

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