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Abstract  

Solid-liquid phase diagrams have been determined for binary systems of pyridine withn-alkanes. These diagrams show the existence of large regions of partial miscibility. A general quasi chemical theory in terms of group surface interactions [1] has been applied to compute these solid-liquid phase diagrams.

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Abstract  

The authors have measured the vapour pressure of the binary four systems, piperidin +1,4-dioxan, piperidin+tetrahydropyran, piperidin+tert-butyl methyl ether and N-methyl piperidin+tert-butyl methyl ether. The measurements were carried out using an isoteniscope built by J. Jose [1]. The vapour pressure, excess Gibbs free energies at 298.15 K, 303.15 K, 313.15 K, 323.15 K, 333.15 K and 343.15 K, are reported for these mixtures. The excess Gibbs free energies have been fitted to the Redlich-Kister equation.

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Abstract  

An important application of agricultural residues is as fuels for combustion processes. This paper shows how thermal analysis can be used for characterization of different kinds of cereals with a view to increasing efficiency in combustion processes. Results are in good agreement with those derived from standard ASTM methods.

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Abstract  

The authors have measured the vapour pressure of the binary systems, piperidine+n -butylamine, piperidine+dipropylamine, piperidine+N-methyl piperidine, piperidine+N,N-dimethyl amino butane and N-methyl piperidine+n -butylamine. The measurements were carried out using an isoteniscope built by Jose [1]. The vapour pressure, excess Gibbs free energies at 298,15, 303,15, 313,15, 323,15, 333,15, and 325,15 K, are reported for these mixtures. The excess Gibbs free energies have been fitted to Redlich-Kister equation.

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The authors have measured the vapour pressure of the four binary systems, piperidine +tert-butyl methyl ether, piperidine +1,4 dioxane, piperidine + tetrahydropyrane and N-methyl piperidine +tert-butyl methyl ether. The measurements were carried out using an isoteniscope built by J. Jose [1], The vapour pressure, excess Gibbs free energies at 298.15, 303.15, 313.15, 323.15, 333.15 and 343.15 K, are reported for these mixtures. The excess Gibbs free energies have been fitted to the Redlich-Kister equation.

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Abstract  

The authors have measured the vapour pressure of four binary systems, morpholine+piperidine, morpholine+1,4-dioxane, morpholine+tetrahydropyrane and 1,4-dioxane+tetrahydropyrane. The measurements were carried out using an isoteniscope built by J. Jose [1]. The vapour pressure, excess Gibbs free energies at 298.15, 303.15, 313.15, 323.15, 333.15 and 343.15 K are reported for these mixtures. The excess Gibbs free energies have been fitted to the Redlich-Kister equation.

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Journal of Thermal Analysis and Calorimetry
Authors: José Lamartine Soares-Sobrinho, Monica Felts de La Roca Soares, Pedro José Rolim-Neto, and Juan J. Torres-Labandeira

Abstract

Although not being the ideal drug due to its low solubility and high toxicity, the benznidazole is the drug currently chosen for Chagas disease treatment. The deep knowledge about the characteristics of the drug in addition to the knowledge of more effective vectorization techniques of drugs in pharmaceutical forms allows a faster and cheaper development of a new therapeutic alternative in comparison to the introduction of a new molecule in the treatment. The aim of this study is the characterization of inclusion complexes Benznidazole and cyclodextrins in solid state. The interactions between Benznidazole (BNZ) and β-cyclodextrins (β-CD) modified: randomly methylated β-CD (RMβCD) and sulfobutylether β-CD (SBβCD) were studied by differential scanning calorimetry (DSC), fourier transform-infrared spectroscopy, RAMAN, and scanning electron microscopy. The preparation of solid-state binary systems by different techniques, namely, kneading, evaporated, and freeze-drying. The results suggest the formation of inclusion complexes of the drug with both CDs types in solid state by the techniques which were used, based on physicochemical data of interaction compared to the drug or the CDs/drug physical mixture. Thus, the preparation technique played an important role in the BNZ and modified CDs.

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Journal of Thermal Analysis and Calorimetry
Authors: Ronaldo S. Nunes, Gilbert Bannach, José M. Luiz, Flávio J. Caires, Claudio T. Carvalho, and Massao Ionashiro

Abstract

Solid-state compounds of general formula Ln2L3·nH2O, where L represents 1,4-bis(3-carboxy-3-oxo-prop-1-enyl)benzene and Ln = La, Ce, Pr, Nd, Sm, were synthesized. Complexometric titrations with EDTA, thermogravimetry (TG), differential thermal analysis (DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, elemental analysis and infrared spectroscopy have been employed to characterize and to study the thermal behavior of these compounds in dynamic air atmosphere. The results led to information about the composition, dehydration, crystallinity, and thermal decomposition of the synthesized compounds.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: G. Brahmanandhan, J. Malathi, D. Khanna, S. Selvasekarapandian, N. Nidhya, R. Usharani, M. Jose, and V. Meenakshisundaram

Abstract  

Samples of natural and manufactured building materials used by the people of Gobichettipalayam town have been analyzed for 226Ra, 232Th and 40K using gamma-ray spectrometry. Radium equivalent activity of the materials has been measured using the formula given by OECD and the geometric mean value of sand, clay and cements are found to be 53.53 Bq·kg−1, 89.09 Bq·kg−1 and 72.25 Bq·kg−1, respectively. The radium equivalent activities obtained in the building materials are all well below the acceptable limit. The indoor gamma-dose has been measured using thermoluminescence dosimeters and it was found in the range of 1051.2–3946.0 μGy/year. The annual effective indoor gamma radiation dose to the people of Gobichettipalayam town has been found to be 0.8 mSv/y.

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Abstract

The hydrogenation of citral over Au, Ir–Au and Ir catalysts prepared from colloids using as supports TiO2 and Nb2O5 has been studied. The samples were characterized by N2 adsorption at 77 K, transmission electron microscopy and temperature programmed reduction. The reactivity and selectivity differences between the prepared catalysts have been explained considering that the deposition of colloids prepared in basic media at high pressures of hydrogen occurs preferentially as iridium oxide or gold complexes, similarly to classical methods of preparation (wetness impregnation and deposition–precipitation). In this sense, the catalytic behavior of supported colloids is similar to these methods without the reduction process. This was corroborated when the solids were reduced at 773 K, which leads to catalysts active and highly selective to the hydrogenation of the carbonyl bond.

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