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| Pacheco,Anderson Almeida; Ker,João Carlos; Schaefer,Carlos Ernesto Gonçalves Reynaud; Fontes,Mauricio Paulo Ferreira; Andrade,Felipe Vaz; Martins,Eder de Souza; Oliveira,Fábio Soares de. |
| ABSTRACT Although the physical environment of the Atlantic Forest realm is well known, studies on the soil-landform relationships are fundamental to improve the management of soil resources to facilitate sustainable development. The purpose of this study was to evaluate a representative topossequence on the “Mares de Morros” landscape of deeply weathered regolith on leucocratic granite rocks and demi-orange convex slopes. The soils varied along the topossequence according to drainage and were classified as Acrudox, Pseudogleysol, and Epiaquent. The clay fraction was composed by kaolinite, in association with gibbsite, goethite, hematite, and traces of vermiculite and hydroxy-Al interlayered vermiculite (HIV). The kaolinite crystallinity index obtained by... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Kaolinite crystallinity; Pseudogleysol; “Mares de Morros” landscape; Thermal analysis. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832018000100308 |
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| Lacerda,Luiz Gustavo; Almeida,Rafael Ramires; Demiate,Ivo Mottin; Carvalho Filho,Marco Aurélio Silva; Vasconcelos,Eliane Carvalho; Woiciechowski,Adenise Lorenci; Bannach,Gilbert; Schnitzler,Egon; Soccol,Carlos Ricardo. |
| Starch nutritional fractions as well as thermal properties and other analysis are essential for food and industrial application. Cassava bagasse is an important agro-industrial residue and its starch content was evaluated using two alternative methods. Thermal characterization and microscopy analyses helped to understand how hydrolysis digests starchy fraction of cassava bagasse. The melting point of cassava starch occurred at 169.2ºC. Regarding TG analyses, after moisture content, there were observed two main mass losses for all samples. Results suggest hydrolysis carried out using enzyme is less effective in order to convert total starch content in cassava bagasse. However, using sulfuric acid, fibers are affected by analyses conditions. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amylase; Cassava; Hydrolysis; Thermal analysis. |
| Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132009000700019 |
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| Lacerda,Luiz Gustavo; Azevedo,Jayme Augusto Menegassi; Carvalho Filho,Marco Aurélio da Silva; Demiate,Ivo Mottin; Schnitzler,Egon; Vandenberghe,Luciana Porto de Souza; Soccol,Carlos Ricardo. |
| Cassava starch, partially hydrolyzed by fungal á-amylase, was characterized using thermal analysis, light microscopy and X-ray diffraction. Thermal degradation was initiated at lower degradation temperatures after enzymatic treatment and the DSC (Differential scanning calorimetry) analysis showed almost similar range of gelatinization temperature, but the enthalpies of gelatinization were quite increased for the partially hydrolyzed starch granules. The results suggested that the partial degradation of the starch granules was concentrated in the amorphous regions. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Amylase; Cassava; Hydrolysis; Thermal analysis. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132008000600016 |
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| Oliveira,Cristina Soltovski de; Bisinella,Radla Zabian Bassetto; Bet,Camila Delinski; Beninca,Cleoci; Demiate,Ivo Mottin; Schnitzler,Egon. |
| Abstract Ginger and white yam starches were investigated and compared with maize starch. Proximal composition, thermogravimetry, differential scanning calorimetry, microscopy, colourimetry, X-ray powder diffractometry and pasting profile were analysed. The unconventional starches presented higher protein and ash contents than the maize starch, that had the highest thermal stability. Higher gelatinisation temperatures were reported for ginger starch, and the enthalpy of the unconventional starches were similar. The maize starch presented the lowest gelatinisation values. For the corn starch the granules were polygonal and smaller than the unconventional starches, and oval shapes and larger diameters were found for the ginger and yam starches. The... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Native starch; Gelatinization; Thermal analysis; Pasting profile. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132019000100516 |
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| Almeida,Mariana Mandelli de; Lima,Cibele Rosana Ribeiro de Castro; Quenca-Guillen,Joyce Santos; Moscardini Filho,Elder; Mercuri,Lucildes Pita; Santoro,Maria Inês Rocha Miritello; Kedor-Hackmann,Erika Rosa Maria. |
| In view of the increase in the number of cosmetic preparations containing antioxidant vitamins, chiefly, due to their action in preventing the process of skin aging, there is a need to develop pre-formulation studies and to validate analytical methods in order to obtain high quality products. Thus, the objective of this research was to evaluate and compare the thermal behavior of tocopheryl acetate and ascorbyl tetraisopalmitate as raw materials, and incorporated into a base cream. Thermogravimetry (TG / DTG) and differential scanning calorimetry (DSC) were used for this purpose. Both vitamins were found to be stable up to 250ºC. The base cream (placebo) and the sample (base cream containing the vitamins) presented different weight loss. Thermal analysis... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Thermal analysis; Cosmetic emulsion/qualitative analysis; Cosmetics/quality control; Tocopheryl acetate/antioxidant action; Ascorbyl tetraisopalmitate/antioxidant action; Vitamins/use in cosmetics. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502010000100015 |
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| Alves,Ricardo; Reis,Thaís Vitória da Silva; Silva,Luis Carlos Cides da; Storpírtis,Silvia; Mercuri,Lucildes Pita; Matos,Jivaldo do Rosário. |
| The thermal behavior of two polymorphic forms of rifampicin was studied by DSC and TG/DTG. The thermoanalytical results clearly showed the differences between the two crystalline forms. Polymorph I was the most thermally stable form, the DSC curve showed no fusion for this species and the thermal decomposition process occurred around 245 ºC. The DSC curve of polymorph II showed two consecutive events, an endothermic event (Tpeak = 193.9 ºC) and one exothermic event (Tpeak = 209.4 ºC), due to a melting process followed by recrystallization, which was attributed to the conversion of form II to form I. Isothermal and non-isothermal thermogravimetric methods were used to determine the kinetic parameters of the thermal decomposition process. For non-isothermal... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Rifampicin; Tuberculosis; Thermal analysis; Thermal decomposition; Kinetic analysis. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502010000200022 |
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| Araújo,Adriano Antunes Souza; Bezerra,Marília dos Santos; Storpirtis,Sílvia; Matos,Jivaldo do Rosário. |
| The determination of chemical purity, melting range, and variation of enthalpy in the process of characterizing medicines is one of the principal requirements evaluated in quality control of the pharmaceutical industry. In this study, the method of purity determination using DSC was outlined, as well as the application of this technique for the evaluation of commercial samples of zidovudine (AZT) (raw material) supplied by different laboratories. To this end, samples from six different laboratories (A, B, C, D, E, and F) and the standard reference (R) from the United States Pharmacopeia (USP) were analyzed. The DSC curves were obtained in the temperature range of 25 to 200 ºC under the dynamic atmosphere of N2 (50 mL min-1), heating rate of β=2 ºC min-1,... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Zidovudine/purity determination; Differential scanning calorimetry; Thermal analysis; Medicines/quality control; Medicines/qualitative analysis. |
| Ano: 2010 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502010000100005 |
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| Ângelo,Marilene Lopes; Ruela,André Luís Morais; Ferreira,Anna Clara Marques; Ramos,Marcus Vinicus de Faria; Montanari,Cristina Martiniano; Silva,Lucélia Magalhães da; Araújo,Magali Benjamim de. |
| We propose to evaluate the dissolution properties of rosuvastatin calcium (ROSC) capsules in different media to characterize the discriminatory power of the assay method. Dissolution assays were performed in media with different pH, and including the surfactant sodium dodecyl sulfate (SDS). Several immediate-release formulations were manufactured using the commercial raw material characterized as amorphous solid. The hydrophobic adjutant magnesium stearate was employed in some formulations due to its negative effect in the wettability and dissolution efficacy of solid dosages. These formulations showed the lower dissolution efficacy values in media without surfactant; however, when SDS was added to the medium, the dissolution efficacy increased, and the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Dissolution; Crystal polymorphism; Solid dosage form; X-ray powder diffractometry; Thermal analysis; Solubility. |
| Ano: 2019 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-82502019000100527 |
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