| Author (s): |
MARTINEZ, A. D.; KID, B. J.
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| Title: |
A TRIBUTE TO PROF. DR. LAVINEL G. IONESCU ON HIS 70th BIRTHDAY |
| Abstract: |
Dr. Ionescu celebrated his 70th birthday in Brazil, working as the Cheif Editor of the SBJCHEM.
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| Keywords: |
History of chemistry, history and philosophy of science, noble gases, surfactants and micelles, micellar catalysis, solution thermodynamics.
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| Year: |
2013
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| Initial page: |
1
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| Final page: |
18
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v21.n21.2013.2_revista2013.pdf |
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| Author (s): |
DE BONI, Luis A. B.; MARIA, Teresa M. R.; Pereira, M. M.; da Silva, Isaac N. L.
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| Title: |
THE PRODUCTION OF BIODIESEL MONITORED WITH REAL-TIME LASER SPECTROSCOPY. CONFIRMATION OF THE TECHNIQUE WITH PROTON NUCLEAR MAGNETIC RESONANCE |
| Abstract: |
Biodiesel is a synthetic fuel usually produced by the transesterification reaction. This study was undertaken in order to monitor the kinetics of the transesterification reaction between soybean oil and methanol catalyzed by KOH and determine when the reaction reached chemical equilibrium. A series of reactions was monitored with a laser spectrometer used to analyze the absorption and scattering of light in real-time. The monitoring system combined the information received through multiple sensors. The correlation of the present technique with 1H-NMR spectra confirmed that the reaction was approaching chemical equilibrium when the monitoring curve showed asymptotic behavior.
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| Keywords: |
Biodiesel, laser measurements, 1H NMR, chemical kinetics, optical activity of chemical reaction, multiple sensors .
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| Year: |
2013
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| Initial page: |
19
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| Final page: |
29
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v21.n21.2013.20_revista2013.pdf |
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| Author (s): |
GOMAA, Esam A.; ABOU ELLEET, Elsayed M.; HELMY, E. T.; DEFRAWY, Sh. M.
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| Title: |
SOLVENT EFFECTS ON THE THERMODYNAMICS OF SOLVATION OF BARIUUM DIPHENYLAMINESULFONATE IN ETHANOL-WATER MIXED SOLVENTS |
| Abstract: |
The aim of this study was to determine the thermodynamic functions, Gibbs energy, enthalpy, and entropy for the solution processes of barium diphenylaminesulfonate in the mixed solvent (ethanol+water) were calculated from solubility values obtained at temperatures ranging from 293.15 K to 308.15 K. The respective thermodynamic, functions for mixing and solvation processes, as well as the activity coefficients for the solute were calculated. The solubility of solutes in mixed solvents depends primarily on the solvation of the solutes or their constituent ions by the components of the solvent mixtures. In this study, the solubility of this barium diphenyla1ninesuifonate in the mixed solvent (ethanol + water by value percent of ethanol= 0, 20, 40, 60, 80, and 100% by volume), was determined at different temperature by the solvent evaporation method. The results enable us to estimate the value of thermodynamic solubility product, Kop(th), of barium diphenylaminesulfonate in the mixed solvent. In addition, Gibbs energy, enthalpy, entropy for the solution processes, and free energies of transfer of barium diphenyla1ninesulfonate units from water to the ethanol solutions were also calculated in order to estimate the contributions of solute-solvent interactions related to ion association are based on changes in the electrostatic properties of the solvent, solute, and ion salvation as itself as on the ionic strength of the medium.
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| Keywords: |
Solubility, thermodynamics, solubility product; mixed solvents, barium diphenylaminesulfonat.
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| Year: |
2013
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| Initial page: |
31
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| Final page: |
40
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v21.n21.2013.31_revista2013.pdf |
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| Author (s): |
ADEJORO, I. Ajibade; ADEBOYE, O. Olubunmi
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| Title: |
QUANTUM MECHANICAL STUDIES OF THE KINETICS, MECHANISMS AND THERMODYNAMICS OF THE GAS-PHASE THERMAL DECOMPOSITION OF ETHYLVINYL ETHER |
| Abstract: |
The thermal decomposition of Ethyl Vinyl Ether was studied using Austin Model (AMI), Re-parameterized Austin Model (RMI), Parameterized Model 3 (PM#) and Modified Neglect of Diatomic Overlap (MNDO) Hamiltonian in the Semi-Empirical method, Hartree-Foch at 3-21G,6-31G*, 6-31G** level, and Density Functional method with Becke 3 Lee Yang Parr (B3LYP), 6-31G* in the Ab-initio method of calculation in Spartan '10. The geometric properties such as the bond length, dihedral, bond angles, heat of formation, atomic charges, and vibrational frequencies were obtained. The data were used to calculate the change in enthalpy delta H, entropy deltaS, free energy delta G, pre-exponential factor A, Rate, K at 624K, and the variation of rate, K with temperatures at 498K - 773K at temperature interval of 25K. It was observed that the values obtained are in good agreement with experimental values for both semi-empirical and ab-initio methods and according to Arrhenius Theory, calculated rate K, increases with an increase in temperature.
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| Keywords: |
Kinetics, ethyl vinyl ether, semi-empirical, ab-initio, transition state.
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| Year: |
2013
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| Initial page: |
41
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| Final page: |
60
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v21.n21.2013.41_revista2013.pdf |
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| Author (s): |
AGRAWAL, R.; MISHRA, M. K.; MARGANDAN, K.; SINGH, K.; ACHARYA, R.; SHARMA, S.; QANUNGO, K.
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| Title: |
FLUORIDE REMOVAL USING ACTIVATED ALUMINA: A CASE STUDY OF BHOOMA CHOTA WATER |
| Abstract: |
The adsorption of fluoride, from a fluoride, contaminated groundwater sample from the village, Bhooma Chota, District Sikar, in the Sate of Rajasthan, India, has been studied using alumina grade DF-101. The fluoride absorption capacity (q1) has been fitted into the pseudo-first-order adsorption, pseudo-second-order adsorption, Elovich, and intraparticle diffusion models. It has been found that the kinetic data fits best in the pseudo-second-order rate equation giving a very high correlation coefficient (R2 = 0.991). the modeled fluoride absorption capacity (q1) has been calculated from the various equations using the constants derived from the least square regression plots. The calculated q1 values, model the experimental data very well, for the pseudo-second-order and Elovich equations, as is evident from the sum of square error calculations. Fluoride removal is through a combination of surface absorption and intraparticle diffusion. A study of the fluoride removal process with increasing dosage of activated alumina reveals that though the percentage of fluoride removal increases with activated alumina, the adsorption capacity at equilibrium decreases. The minimum dosage of activated alumina which causes the maximum percentage removal of fluoride from water, while at the same time brings forth its highest equilibrium absorption capacity has been determined.
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| Keywords: |
Activated alumina, fluoride adsorption.
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| Year: |
2013
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| Initial page: |
61
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| Final page: |
77
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v21.n21.2013.61_revista2013.pdf |
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| Author (s): |
Margandan, K.; Agrawal, R.; Singh, K.; Acharya, R.; Sharma, S.; Qannngo, K.
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| Title: |
TESTING OF A DEFLUORIDATING FILTER USING MgO-CaO-CaCI2 FOR USE IN RURAL RAJASTHAN |
| Abstract: |
A Magnesium Oxide-based defluoridation technique using MgO-CaO-Calcium Chloride and pH adjustment by Sodium Bisulphate has been suitably modified for use with fluoride contaminated local groundwater having high alkalinity. Taking into consideration the high bicarbonate concentration in raw groundwater the proportion of the lime has been changed. It was found that sodium bisulphate was not suitable for pH adjustment due to the high concentration of sulphate in the pH adjusted water. Therefore dilute HCl was used instead. Six trials of the adapted defluoridation technique have been carried out in the laboratory successfully at 50-liter scale.
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| Keywords: |
Defluoridation, defluoridating filter, MgO, CaO, calcium chloride.
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| Year: |
2013
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| Initial page: |
79
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| Final page: |
95
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v21.n21.2013.78_revista2013.pdf |
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| Author (s): |
ASHISH, Gawai; SANJIB, Das; PATHAK, Yasbwant
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| Title: |
NEW 7-(2-(BENZOL[d]THIAZOL-2-YLAMINO)ETHOXY)-4-METHYL-2HCHROMEN-2-0NE DERIVATIES WITH ATYPICAL ANTIPSYCHOTIC ACTIVITY |
| Abstract: |
A new series of 7-(2-(benzo[d]thiazol-2-ylamino)ethoxy)-4-methyl-2H-chromen-2-one derivatives(4a4k) was synthesized and evaluated for their D2 and 51HT2 antagonistic activity as a measure of atypical antipsychotic properly. Compounds 7-(2-(benzo[d]thiazo/-2-ylamino)ethoxy)-4-methyl-2H-chromen-2- one derivatives (4a-4k) was synthesized by refluxing 2-amino benzothiazoles substituted derivatives (3a3k) and 7-(2-Chloroethoxy)-4-melhyl-2H-chromen-2-one (2) in dry pyridine. The synthesized compounds were characterized with the help of spectral and analytical data. Most of these compounds showed dopamine D2 receptor antagonistic activity from moderate to high potency along with serotonin 5-HT2 receptor blockage activity: a property that has been suggested to be necessary for the atypical nature of antipsychotic agents. The D2 and 5-HT2 receptor blockage activity was evaluated by inhibition of apomorphine-induced climbing behavior and 5HTP induced head twitches in mice respectively.
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| Keywords: |
Schizophrenia, atypical antipsychotics, benzotblazole. Chromen-2-one.
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| Year: |
2013
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| Initial page: |
97
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| Final page: |
108
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v21.n21.2013.95_revista2013.pdf |
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| Author (s): |
DAS NEVES, Paulo Cesar Pereira; ATENCIO, Daniel; IONESCU, Lavinel G.
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| Title: |
A BRIEF HISTORY OF MINERALOGY IN BRAZIL |
| Abstract: |
This article presents a brief history of mineralogy in Brazil. Special attention is given to the contribution of José Bonifacio de Andrada e Silva and also to the minerals that were first described in Brazil, the so-called "type -minerals" of Brazil.
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| Keywords: |
Mineralogy in Brazil, Jose Bonifacio de Andrada e Silva, type minerals of Brazil.
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| Year: |
2013
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| Initial page: |
109
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| Final page: |
127
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| Link: |
Acessar |
| DOI: |
10.48141/SBJCHEM.v21.n21.2013.107_revista2013.pdf |
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